Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/09/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
122 PM CDT TUE APR 7 2015
.AVIATION...07/18Z TAF CYCLE
MVFR CIGS WL BE NOTED ACRS THE FA THRU MOST OF THIS AFTN. HOWEVER...
INCRSG LOW LVL MIXING WL HELP CIGS TO GRADUALLY LIFT TO VFR LVLS
LATER THIS AFTN AND LINGER INTO THIS EVENING. LOW CLOUDS WL THEN
RETURN LATER TNGT...WITH VFR/MVFR CONDS EXPECTED. OUTSIDE AN ISOLD
SHRA/TSRA THRU THIS EVENING...NO ORGANIZED CONVECTION IS
ANTICIPATED TO AFFECT THE FA THRU WED MRNG. /44/
&&
.PREV DISCUSSION... /ISSUED 1009 AM CDT TUE APR 7 2015/
UPDATE...
NO SIGNIFICANT CHANGES MADE FOR THE MORNING UPDATE. RADAR TRENDS
SHOW THAT PRECIPITATION IS ABOUT TO COME TO AN END ACROSS THE
FORECAST AREA...WITH ONLY SOME ISOLATED THUNDERSTORMS LEFT UP
AROUND THE BATESVILLE AREA AS OF 10 AM. BY NOON ALL RAIN WILL HAVE
EXITED AND EXPECT DRY CONDITIONS FOR THE REST OF TODAY. ADJUSTED
POPS THROUGH THE MORNING TO REFLECT THESE TRENDS...AND HAVE NO
PRECIP MENTIONED FOR THE AFTERNOON PERIOD. TEMPERATURES LOOK ON
TRACK SO NO ADJUSTMENTS THERE EITHER.
PREV DISCUSSION... /ISSUED 621 AM CDT TUE APR 7 2015/
AVIATION...
SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS
MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL
IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS
VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL
RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY
AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT.
PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/
SHORT TERM...TODAY THROUGH FRIDAY
SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING
THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS
THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING
HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE
MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE.
OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY
CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR
PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN
ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT
CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT
STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY.
WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY
ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE
STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON
WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST
ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING
THE CAP.
THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER
ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO
THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE.
MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER
IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT
ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z
FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF
STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH
THIS SYSTEM.
HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR
FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE.
TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS.
LONG TERM...FRIDAY NIGHT THROUGH MONDAY
HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH
THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL
MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT
BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO
THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT...
AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A
BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE
LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO
THE REGION DURING THE DAY.
IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY
BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP...
PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS...
HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO
MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST
SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS
THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE
MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY
TUNED.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1009 AM CDT TUE APR 7 2015
.UPDATE...
NO SIGNIFICANT CHANGES MADE FOR THE MORNING UPDATE. RADAR TRENDS
SHOW THAT PRECIPITATION IS ABOUT TO COME TO AN END ACROSS THE
FORECAST AREA...WITH ONLY SOME ISOLATED THUNDERSTORMS LEFT UP
AROUND THE BATESVILLE AREA AS OF 10 AM. BY NOON ALL RAIN WILL HAVE
EXITED AND EXPECT DRY CONDITIONS FOR THE REST OF TODAY. ADJUSTED
POPS THROUGH THE MORNING TO REFLECT THESE TRENDS...AND HAVE NO
PRECIP MENTIONED FOR THE AFTERNOON PERIOD. TEMPERATURES LOOK ON
TRACK SO NO ADJUSTMENTS THERE EITHER.
&&
.PREV DISCUSSION... /ISSUED 621 AM CDT TUE APR 7 2015/
AVIATION...
SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS
MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL
IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS
VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL
RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY
AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT.
PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/
SHORT TERM...TODAY THROUGH FRIDAY
SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING
THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS
THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING
HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE
MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE.
OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY
CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR
PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN
ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT
CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT
STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY.
WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY
ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE
STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON
WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST
ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING
THE CAP.
THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER
ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO
THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE.
MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER
IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT
ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z
FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF
STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH
THIS SYSTEM.
HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR
FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE.
TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS.
LONG TERM...FRIDAY NIGHT THROUGH MONDAY
HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH
THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL
MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT
BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO
THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT...
AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A
BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE
LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO
THE REGION DURING THE DAY.
IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY
BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP...
PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS...
HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO
MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST
SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS
THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE
MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY
TUNED.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 80 65 82 65 / 30 10 20 30
CAMDEN AR 83 65 84 66 / 20 10 10 20
HARRISON AR 80 63 82 63 / 10 20 20 40
HOT SPRINGS AR 81 67 82 66 / 20 10 10 20
LITTLE ROCK AR 82 66 83 65 / 30 10 10 20
MONTICELLO AR 82 65 84 67 / 20 10 10 10
MOUNT IDA AR 80 66 79 67 / 10 10 10 30
MOUNTAIN HOME AR 79 63 83 63 / 20 20 20 40
NEWPORT AR 80 65 82 66 / 30 20 20 20
PINE BLUFF AR 82 65 83 65 / 30 10 10 20
RUSSELLVILLE AR 81 63 83 64 / 20 10 20 30
SEARCY AR 80 63 82 64 / 30 10 20 20
STUTTGART AR 81 66 82 66 / 30 10 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
64
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
621 AM CDT TUE APR 7 2015
.AVIATION...
SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS
MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL
IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS
VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL
RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY
AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/
SHORT TERM...TODAY THROUGH FRIDAY
SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING
THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS
THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING
HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE
MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE.
OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY
CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR
PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN
ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT
CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT
STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY.
WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY
ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE
STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON
WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST
ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING
THE CAP.
THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER
ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO
THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE.
MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER
IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT
ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z
FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF
STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH
THIS SYSTEM.
HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR
FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE.
TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS.
LONG TERM...FRIDAY NIGHT THROUGH MONDAY
HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH
THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL
MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT
BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO
THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT...
AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A
BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE
LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO
THE REGION DURING THE DAY.
IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY
BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP...
PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS...
HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO
MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST
SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS
THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE
MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY
TUNED.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...57
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
333 AM CDT TUE APR 7 2015
.SHORT TERM...TODAY THROUGH FRIDAY
SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING
THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS
THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING
HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE
MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE.
OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY
CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR
PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN
ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT
CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT
STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY.
WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY
ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE
STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON
WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST
ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING
THE CAP.
THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER
ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO
THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE.
MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER
IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT
ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z
FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF
STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH
THIS SYSTEM.
HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR
FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE.
TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS.
&&
.LONG TERM...FRIDAY NIGHT THROUGH MONDAY
HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH
THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL
MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT
BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO
THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT...
AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A
BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE
LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO
THE REGION DURING THE DAY.
IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY
BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP...
PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS...
HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO
MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST
SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS
THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE
MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY
TUNED.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 80 65 82 65 / 20 10 20 30
CAMDEN AR 83 65 84 66 / 20 10 10 20
HARRISON AR 80 63 82 63 / 20 20 30 40
HOT SPRINGS AR 81 67 82 66 / 20 10 10 20
LITTLE ROCK AR 82 66 83 65 / 20 10 10 20
MONTICELLO AR 82 65 84 67 / 20 10 10 10
MOUNT IDA AR 80 66 79 67 / 20 10 10 30
MOUNTAIN HOME AR 79 63 83 63 / 20 20 30 40
NEWPORT AR 80 65 82 66 / 20 20 20 20
PINE BLUFF AR 82 65 83 65 / 20 10 10 20
RUSSELLVILLE AR 81 63 83 64 / 20 10 20 30
SEARCY AR 80 63 82 64 / 20 10 20 20
STUTTGART AR 81 66 82 66 / 20 10 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65 / LONG TERM...57
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1005 AM PDT TUE APR 7 2015
.UPDATE...
CURRENT FORECAST IS GENERALLY ON THE RIGHT TRACK WITH NO
SIGNIFICANT CHANGES PLANNED THIS MORNING.
SO FAR THIS MORNING, THE MAIN IMPACTS OF THE SNOW BAND OVER
CALIFORNIA HAVE BEEN LIMITED TO AREAS NEAR AND WEST OF THE SIERRA
CREST. CHAIN CONTROLS ARE CURRENTLY IN PLACE ON I-80 OVER DONNER
SUMMIT AND CA 88 OVER CARSON PASS. FOR THE REMAINDER OF THE
MORNING, THE STEADY SNOW BAND WILL BEGIN TO DECREASE IN COVERAGE WITH
SOME AREAS OF MOISTURE BREAKING OFF AND SPREADING INTO WESTERN NV.
AIR MASS IN LOWER ELEVATIONS IS STILL RELATIVELY DRY SO LITTLE OR
NO MEASURABLE PRECIP IS EXPECTED ACROSS THE RENO-CARSON CITY
VICINITY THROUGH MIDDAY.
FOR THIS AFTERNOON AS THE COLD POOL ALOFT MOVES INTO CENTRAL CA,
CONVECTION WILL INCREASE WITH BANDS OF SNOW SHOWERS SPREADING OVER
THE SIERRA. ROAD SURFACES WILL LIKELY BECOME WET OR SLUSHY NEAR
THE SIERRA FROM MIDDAY THROUGH MID AFTERNOON AS HIGHER SUN ANGLES
ASSIST IN MELTING OFF THE SNOW WHICH HAS ALREADY FALLEN. SOME OF
THIS SNOW SHOWER ACTIVITY WILL CONTINUE INTO THE EVENING WITH
POTENTIAL FOR MORE TRAVEL IMPACTS AS ROAD SURFACE TEMPS DECREASE.
FOR WESTERN NV, THE TRANSITION TO A CONVECTIVE REGIME WILL LEAD TO
INCREASED SHOWER DEVELOPMENT WITH ISOLATED THUNDERSTORMS POSSIBLE
WITH SMALL HAIL OR GRAUPEL OCCURRING WITH STRONGER CELLS. THE
LATEST HRRR AND NAM GUIDANCE SHOW CONDITIONS A LITTLE MORE
FAVORABLE FOR THUNDER IN AREAS NORTH AND EAST OF A RENO-FALLON
LINE BETWEEN 1 AND 7 PM.
FARTHER SOUTH IN MONO COUNTY, THE MONO LAKE WEB CAMERA SHOWED A
SMALL AREA OF BLOWING DUST WITH A WIND SENSOR NEAR THE LAKE
SHOWING SPEEDS IN THE 20-30 MPH RANGE. SOME GUSTS TO 40 MPH WILL
BE POSSIBLE ALONG HIGHWAY 395 BEFORE SHOWERS SPREAD ACROSS THE
COUNTY LATER TODAY. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 247 AM PDT TUE APR 7 2015/
SYNOPSIS...
LOW PRESSURE WILL BRING SNOW AND SLICK ROAD CONDITIONS TO THE
SIERRA TODAY INTO WEDNESDAY MORNING, WITH SNOW AND RAIN SHOWERS IN
LOWER ELEVATIONS. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MIDWEEK,
FOLLOWED BY A WARMING AND DRYING TREND LATER IN THE WEEK.
SHORT TERM...
A COLD SPRING STORM IS BEGINNING TO PUSH A BAND OF PRECIPITATION
ACROSS THE NORTHERN CALIFORNIA COAST EARLY THIS MORNING. THIS BAND
OF PRECIPITATION WILL PUSH EASTWARD AND PROVIDE ACCUMULATING SNOW IN
THE SIERRA LATER THIS MORNING THROUGH EARLY WEDNESDAY MORNING. WINTER
WEATHER ADVISORIES ARE IN PLACE ACROSS THE EASTERN SIERRA WHERE SNOW
COVERED ROADS AND CHAIN RESTRICTIONS ARE EXPECTED THROUGH THE
SIERRA. SNOW ACCUMULATIONS THROUGH WEDNESDAY MORNING ACROSS THE
EASTERN SIERRA ARE GENERALLY IN THE 6-12" RANGE FOR LOCATIONS ABOVE
7,000 FEET WITH ABOUT 3-6" THROUGH THE TAHOE BASIN AND AREAS WEST OF
HWY 395 THROUGH MONO COUNTY. INSTABILITY WILL INCREASE THROUGH THE
DAY AS THE COLD CORE OF THE UPPER LOW SETTLES ACROSS THE REGION.
THIS WILL PROMOTE THE DEVELOPMENT OF LOCALIZED AREAS OF HEAVIER
SNOWFALL WITHIN STRONGER CELLS, SNOW PELLETS, SMALL HAIL, AND
ISOLATED LIGHTNING STRIKES.
ACROSS WESTERN NEVADA, SHOWERS LOOK TO PUSH INTO THE AREA AFTER NOON
WITH A MIX OR RAIN AND SNOW EXPECTED AS SNOW LEVELS HOVER AROUND
4,500-5,000 FEET THROUGH THE DAY. LITTLE TO NO ACCUMULATION IS
EXPECTED ACROSS WESTERN NEVADA VALLEYS WITH HIGH SUN ANGLES IN
PLACE, BUT LOCATIONS ABOVE 5,000 MAY SEE BETTER CHANCES FOR SOME
SLUSHY ACCUMULATIONS. SHOWERS WILL LINGER THROUGH THE EVENING WITH
THE BULK THE HEAVIER PRECIPITATION ENDING BY LATE AFTERNOON. TRAVEL
IMPACTS ARE POSSIBLE THROUGH TONIGHT AS SHOWERS DIMINISH BUT
POTENTIAL INCREASES FOR SNOW TO STICK ON ROADWAYS ACROSS THE SIERRA.
BREEZY CONDITIONS WILL ACCOMPANY THE STORM WITH SOUTHERLY WINDS
SHIFTING WEST BY EARLY AFTERNOON THEN NORTHWEST THIS EVENING AS THE
COLD FRONT PUSHES ACROSS THE REGION. WILL GENERALLY SEE GUSTS IN THE
30-35 MPH RANGE WITH GUSTS ACROSS THE SIERRA CREST AROUND 60-70 MPH.
CHOPPY CONDITIONS EXPECTED ACROSS AREAS LAKES WITH WINDS LESSENING
WITH THE ONSET OF PRECIPITATION.
BY WEDNESDAY MORNING, THE MAIN UPPER LOW SHIFTS EASTWARD ACROSS UTAH
WITH ONLY A FEW LIGHT LINGERING SHOWERS EXPECTED. SOME BANDED
PRECIPITATION IS POSSIBLE ON THE BACKSIDE OF THE LOW BUT IT LOOKS TO
BE MAINLY CONFINED TO FAR NORTHEASTERN NEVADA WITH SOME SHOWERS
EXTENDING AS FAR WEST AS FAR NORTHERN WASHOE COUNTY AND THE SURPRISE
VALLEY. SHOWERS DIMINISH BY WEDNESDAY EVENING AS A SHORTWAVE BEGINS
TO BUILD ACROSS THE AREA BY THURSDAY WHERE DAYTIME TEMPERATURES
WILL REBOUND BACK INTO THE LOWER 60S ACROSS WESTERN NEVADA AND MID
50S FOR THE SIERRA. FUENTES
LONG TERM...FRIDAY THROUGH MONDAY...
FORECASTER CONFIDENCE IS RISING FOR THE EXTENDED FORECAST AS MODELS
HAVE COME INTO BETTER AGREEMENT OVER THE LAST 24 HOURS SHOWING THE
DEVELOPING PATTERN OVER THE WEST COAST. GFS CONTINUES TO TREND LOWER
HEIGHTS OVER NORTHERN CA/NV FOR THE WEEKEND AS THE NORTHERN BRANCH
OF A SPLIT JET DIVES INTO THE WEST COAST AND ACROSS THE GREAT BASIN.
ECMWF AND GEM ARE IN GOOD AGREEMENT AS WELL, BRINGING A COLD FRONT
ACROSS THE REGION WITH CHANCES OF LIGHT PRECIPITATION. THE MAJORITY
OF THE PRECIP/DYNAMICS WILL REMAIN IN THE PACIFIC NORTHWEST WITH
ONLY A VERY MODEST AMOUNT OF MOISTURE PUSHING NEAR THE CA/NV/OR
BORDER. IN THAT AREA NORTH OF SUSANVILLE, WE EXPANDED THE SLIGHT
CHANCE OF SHOWERS INTO SATURDAY AND KEPT CHANCES IN THROUGH SUNDAY
TO ACCOUNT FOR MODEL DIFFERENCES IN THE TIMING OF THE WAVE.
WE SHOULD BEGIN TO WARM BACK UP SUNDAY-MONDAY AS WEAK RIDGING BUILDS
OVER THE WEST COAST. MODELS CONTINUE TO HINT AT YET ANOTHER TROUGH
DROPPING OUT OF THE GULF OF ALASKA AND INTO THE PAC NW NEXT WEEK,
KEEPING THE ACTIVE WEATHER PATTERN GOING. HOON
AVIATION...
SIGNIFICANT SPRING STORM WILL BE PUSHING INTO THE SIERRA TODAY WITH
LIGHT SHOWERS IN WESTERN NEVADA. IFR CIGS/VIS WILL DEVELOP AROUND
16Z THIS MORNING AROUND THE TAHOE BASIN WITH PERIODS OF MODERATE
SNOW. SHOWERS WILL LINGER THROUGH TONIGHT IN THE SIERRA WITH PERIODS
OF MVFR/IFR.
FOR WESTERN NEVADA, THE BEST POSSIBLE TIME FOR SPILLOVER WILL BE
BETWEEN 18Z-00Z WITH A MIX OF RAIN, SNOW AND SNOW PELLET SHOWERS
POSSIBLE. IN ADDITION, THERE IS A 15 PERCENT FOR THUNDERSTORMS
TODAY, BUT CONFIDENCE IS LOW IN PINPOINTING THE LOCATION OF
WHERE THE STORMS WILL FORM.
ACCUMULATING SNOW IS LIKELY ON RUNWAYS AT KTRK, KTVL, AND KMMH
TODAY, THOUGH IT MAY JUST BE SLUSHY DURING THE MIDDLE PART OF THE
DAY DUE TO THE APRIL SUN ANGLE. MIDDAY WILL BE THE BEST CHANCES FOR
SPILLOVER INTO WESTERN NEVADA, SO IT IS UNLIKELY SNOW WILL ACCUMULATE
ON RUNWAYS AT KRNO OR KCXP.
SOUTHERLY WINDS TOMORROW WILL BECOME WESTERLY BEHIND THE COLD
FRONTAL PASSAGE, WHICH WILL BE APPROXIMATELY BETWEEN 18-21Z. WINDS
MAY GUST AS HIGH AS 25-30 KTS IN VALLEYS WITH 55-60 KTS ACROSS
SIERRA RIDGES. THIS WILL LEAD TO WEAK TO MODERATE MOUNTAIN
TURBULENCE AND A SLIGHT CHANCE OF LOW LEVEL WIND SHEAR ALONG THE
COLD FRONT. DJ/HOON
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY NVZ002.
CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ071.
WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ073.
WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
434 AM PDT TUE APR 7 2015
...LATE SEASON STORM TO IMPACT THE REGION THROUGH TONIGHT...
.SYNOPSIS...RAIN WILL GO THROUGH OUR AREA THIS MORNING. ALONG
WITH LOCALLY HEAVY RAINFALL...THUNDERSTORMS WITH SMALL HAIL AND
GUSTY WINDS WILL BE POSSIBLE AS THE SYSTEM MOVES INLAND. IN
ADDITION...SNOW ACCUMULATIONS WILL BE POSSIBLE OVER THE SANTA
LUCIA RANGE ABOVE 4000 FEET. DRY WEATHER CONDITIONS RETURN BY
MIDWEEK AS THE SYSTEM EXITS THE REGION.
&&
.DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AS EXPECTED RADAR
RETURNS HAVE INCREASED THROUGH THE OVERNIGHT HOURS AS A STRONG
FRONT MOVES ACROSS OUR AREA. LATEST LOOK AT KMUX SHOWS A BAND OF
MODERATE RAIN ENTERING THE SF BAY REGION ASSOCIATED WITH THE
HEAVILY ADVERTISED COLD FRONT. SO FAR RAINFALL RETURNS HAVE BEEN
DECENT WITH PARTS OF SONOMA COUNTY OVER THREE QUARTERS OF AN
INCH. LATEST RUN OF THE HRRR SHOWS THE BEST POTENTIAL FOR MODERATE
TO POSSIBLY HEAVY RAINFALL THROUGH THE MORNING HOURS IN A REGION
FROM THE SOUTH BAY OVER TO THE FAR EAST BAY VALLEYS AND THEN SOUTH
INTO SANTA CRUZ COUNTY. THOSE SPOTS COULD EASILY SEE HALF AN INCH
BY MID-MORNING.
WINDS PICKED UP THROUGH THE EVENING HOURS ALTHOUGH STRONG GUSTS
GENERALLY HAVE BEEN CONFINED TO HIGHER ELEVATION SPOTS. A FEW
URBAN AREAS ARE SEEING GUSTS OVER 25 MPH INCLUDING BOTH THE SFO
AND OAKLAND AIRPORTS. FOR SPOTS OVER 1000 FEET GUSTS OVER 35 MPH
ARE FAIRLY COMMON ESPECIALLY FOR OUR TYPICAL WINDY SPOTS.
BEHIND THE COLD FRONT THE ATMOSPHERE WILL DESTABILIZE WITH LIFTED
VALUES EXPECTED TO DROP AS LOW AS MINUS 3 WHILE CAPE VALUES COULD
EXCEED 200 J/KG. WOULD EXPECT AT LEAST A FEW THUNDERSTORMS ACROSS
OUR AREA ALONG WITH REPORTS OF SMALL HAIL. WORTH NOTING THAT VERY
LITTLE DIRECTIONAL SHEER IS FORECAST FOR OUR AREA WITH ONLY
LIMITED SPEED SHEER WHICH WILL HELP TO LIMIT THE THREAT OF SEVERE
WEATHER. THE COOLER AIR WILL LEAD TO LOWER SNOW LEVELS WITH
ACCUMULATIONS EXPECTED OVER 4000 FEET. STILL LOOKS LIKE THE SANTA
LUCIA RANGE COULD PICK UP 3 TO 6 INCHES OF SNOW.
ALL TOO FAMILIAR RIDGE OF HIGH PRESSURE WILL BUILD BACK TO OUR AREA
STARTING ON WEDNESDAY AS THE SYSTEM DEPARTS TO THE EAST. THIS
WILL LEAD TO THE STORM TRACK HEADING BACK WELL TO THE NORTH ALONG
WITH WARMER TEMPERATURES. LONGER RANGE OUTLOOKS DO NOT INDICATE
ANY ADDITIONAL SUBSTANTIAL STORMS PAST TODAY GOING ALL OF THE WAY
TO APRIL 20TH.
&&
.AVIATION...AS OF 04:27 AM PDT TUESDAY...A COLD FRONT IS CURRENTLY
TRAVERSING THE BAY AREA BRINGING RAIN AND GUSTY WINDS. FOR THE
MOST PART FLIGHT CAT ARE VFR WITH A FEW POCKETS OF MVFR. THE
IMPACT TO TERMINALS WILL BE EARLY THIS MORNING THROUGH THE
MORNING RUSH WITH WET RUNWAYS AND WIND. FOLLOWING SHORT TERM
MODELS...RAIN WILL TAPER OFF FROM N-S AFTER 14/15Z. STEADIER RAIN
TRANSITIONS TO HIT MORE MISS SHOWERS/CONVECTIVE NATURE. WINDS WILL ALSO DIMINISH
AFTER 15Z. VFR CONDITIONS TONIGHT. CONF IS MEDIUM.
VICINITY OF KSFO...TIMING OF PERSISTENT RAINFALL THROUGH APPROX
15Z WITH GUSTY WINDS.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...RAIN THROUGH MID MORNING THEN VCSH
THIS AFTERNOON.
&&
.MARINE...AS OF 04:26 AM PDT TUESDAY...A COLD FRONT WILL MOVE
THROUGH THE COASTAL WATERS EARLY TODAY PRODUCING GUSTY
WINDS...RAIN AND THUNDERSTORMS. THE GUSTY WINDS WILL PRODUCE
LOCALLY HAZARDOUS CONDITIONS. WINDS WILL DECREASE FROM NORTH TO
SOUTH THROUGH THE DAY AS THE FRONT EXITS THE REGION WITH AN
IMPROVING SEA STATE. NORTHWEST SWELL THROUGH THE PERIOD.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...WINTER WEATHER ADVISORY...SANTA LUCIA RANGE THROUGH
TONIGHT.
SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 AM
SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 AM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 8 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 8 AM
SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 8 AM
SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 8 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 11 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 11 AM
&&
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
302 AM PDT TUE APR 7 2015
...LATE SEASON STORM TO IMPACT THE REGION THROUGH TONIGHT...
.SYNOPSIS...RAIN WILL GO THROUGH OUR AREA THIS MORNING. ALONG
WITH LOCALLY HEAVY RAINFALL...THUNDERSTORMS WITH SMALL HAIL AND
GUSTY WINDS WILL BE POSSIBLE AS THE SYSTEM MOVES INLAND. IN
ADDITION...SNOW ACCUMULATIONS WILL BE POSSIBLE OVER THE SANTA
LUCIA RANGE ABOVE 4000 FEET. DRY WEATHER CONDITIONS RETURN BY
MIDWEEK AS THE SYSTEM EXITS THE REGION.
&&
.DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AS EXPECTED RADAR
RETURNS HAVE INCREASED THROUGH THE OVERNIGHT HOURS AS A STRONG
FRONT MOVES ACROSS OUR AREA. LATEST LOOK AT KMUX SHOWS A BAND OF
MODERATE RAIN ENTERING THE SF BAY REGION ASSOCIATED WITH THE
HEAVILY ADVERTISED COLD FRONT. SO FAR RAINFALL RETURNS HAVE BEEN
DECENT WITH PARTS OF SONOMA COUNTY OVER THREE QUARTERS OF AN
INCH. LATEST RUN OF THE HRRR SHOWS THE BEST POTENTIAL FOR MODERATE
TO POSSIBLY HEAVY RAINFALL THROUGH THE MORNING HOURS IN A REGION
FROM THE SOUTH BAY OVER TO THE FAR EAST BAY VALLEYS AND THEN SOUTH
INTO SANTA CRUZ COUNTY. THOSE SPOTS COULD EASILY SEE HALF AN INCH
BY MID-MORNING.
WINDS PICKED UP THROUGH THE EVENING HOURS ALTHOUGH STRONG GUSTS
GENERALLY HAVE BEEN CONFINED TO HIGHER ELEVATION SPOTS. A FEW
URBAN AREAS ARE SEEING GUSTS OVER 25 MPH INCLUDING BOTH THE SFO
AND OAKLAND AIRPORTS. FOR SPOTS OVER 1000 FEET GUSTS OVER 35 MPH
ARE FAIRLY COMMON ESPECIALLY FOR OUR TYPICAL WINDY SPOTS.
BEHIND THE COLD FRONT THE ATMOSPHERE WILL DESTABILIZE WITH LIFTED
VALUES EXPECTED TO DROP AS LOW AS MINUS 3 WHILE CAPE VALUES COULD
EXCEED 200 J/KG. WOULD EXPECT AT LEAST A FEW THUNDERSTORMS ACROSS
OUR AREA ALONG WITH REPORTS OF SMALL HAIL. WORTH NOTING THAT VERY
LITTLE DIRECTIONAL SHEER IS FORECAST FOR OUR AREA WITH ONLY
LIMITED SPEED SHEER WHICH WILL HELP TO LIMIT THE THREAT OF SEVERE
WEATHER. THE COOLER AIR WILL LEAD TO LOWER SNOW LEVELS WITH
ACCUMULATIONS EXPECTED OVER 4000 FEET. STILL LOOKS LIKE THE SANTA
LUCIA RANGE COULD PICK UP 3 TO 6 INCHES OF SNOW.
ALL TOO FAMILIAR RIDGE OF HIGH PRESSURE WILL BUILD BACK TO OUR AREA
STARTING ON WEDNESDAY AS THE SYSTEM DEPARTS TO THE EAST. THIS
WILL LEAD TO THE STORM TRACK HEADING BACK WELL TO THE NORTH ALONG
WITH WARMER TEMPERATURES. LONGER RANGE OUTLOOKS DO NOT INDICATE
ANY ADDITIONAL SUBSTANTIAL STORMS PAST TODAY GOING ALL OF THE WAY
TO APRIL 20TH.
&&
.AVIATION...AS OF 10:52 PM PDT MONDAY...GUSTY S-SE PRE-FRONTAL
WIND PATTERN IS EXPECTED OVER THE FORECAST AREA TONIGHT. THE COLD
FRONT WILL SWEEP QUICKLY E-SE ACROSS THE AREA AFTER MIDNIGHT FOLLOWED
BY MUCH COLDER AIR ALOFT AND INSTABILITY SHOWERS BEGINNING EARLY
TUE. ISOLATED T-STORM(S) ALSO POSSIBLE BEGINNING TUE MORNING BUT
MUCH TOO LOW CONFIDENCE TO ATTEMPT TO TIME ONE OR MORE IN THE 00Z
TAFS. A FEW LINGERING SHOWERS ARE POSSIBLE TUE AFTERNOON AND EVENING
OTHERWISE DRIER WEATHER RETURNS TUESDAY NIGHT.
VICINITY OF KSFO...S-SE WINDS EXPECTED TO TREND HIGHER NEAREST THE
COLD FRONTAL PASSAGE VERY LATE TONIGHT/EARLY TUE MORNING. SE GUSTS
UP TO 35 KNOTS LIKELY 06Z-10Z TIME-FRAME. HEAVY SHOWERS TONIGHT/EARLY
TUE MORNING. POST FRONTAL WINDS TUESDAY NOT QUITE AS GUSTY
AS PRE-FRONTAL WINDS.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...DETERIORATING WEATHER CONDITIONS ARE
EXPECTED VERY LATE AT NIGHT. MOD-HEAVY DOWNPOURS EXPECTED WITH
THE COLD FRONTAL PASSAGE EARLY TUE MORNING AS THE FRONT CONTINUES
TO MOVE SE OVER THE CENTRAL COAST. ADDITIONAL PASSING SHOWERS
LIKELY THROUGH THE REMAINDER OF TUESDAY AS THE AIR MASS ALOFT
COOLS OFF APPRECIABLY.
&&
.MARINE...AS OF 3:00 AM PDT TUESDAY...A COLD FRONT WILL MOVE THROUGH
THE COASTAL WATERS EARLY TODAY PRODUCING GUSTY WINDS...RAIN AND
THUNDERSTORMS. THE GUSTY WINDS WILL PRODUCE LOCALLY HAZARDOUS
CONDITIONS. WINDS WILL DECREASE FROM NORTH TO SOUTH THROUGH THE
DAY AS THE FRONT EXITS THE REGION WITH AN IMPROVING SEA STATE.
NORTHWEST SWELL THROUGH THE PERIOD.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...WINTER WEATHER ADVISORY...SANTA LUCIA RANGE THROUGH
TONIGHT.
SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 AM
SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 AM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 8 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 8 AM
SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 8 AM
SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 8 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 11 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 11 AM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: CANEPA
MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1102 AM MDT TUE APR 7 2015
.UPDATE...
ISSUED AT 1059 AM MDT TUE APR 7 2015
DRY SOUTHWEST FLOW ALOFT WILL RESULT IN ANOTHER WINDY DAY TODAY.
GUSTY WINDS WERE ALREADY OBSERVED AT MANY VALLEY LOCATIONS AS
ABUNDANT SUNSHINE MIXES OUT THE MORNING INVERSION. THIS MORNING`S
12Z NAM AND GFS MODELS SHOW THE 300 MB UPPER JET LIFTING INTO WY
THIS AFTERNOON AS A SHORTWAVE OVER SRN NV EJECTS NORTHEAST ACROSS NW
UT. WILL HOLD OFF ON VALLEY WIND ADVISORIES FOR TODAY WITH THE JET
LIFTING NORTH AND THE 15Z HIGH-RESOLUTION HRRR AND RAP MODELS
SHOWING WINDS BELOW THE 45 MPH GUST CRITERIA. BUT...GUSTS TO 35-40
MPH SHOULD BE FAIRLY COMMON FOR MANY VALLEYS OF ERN UT AND WRN CO AS
DEEP MIXING PULLS STRONGER WINDS ALOFT TO THE SURFACE. RED FLAG
WARNINGS FOR FIRE WEATHER LOOK ON TRACK FOR TODAY.
THE UPPER LOW ALONG THE NRN CA COAST THIS MORNING MOVES INLAND TODAY
TO ABOUT NE UT BY MIDDAY WEDNESDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 445 AM MDT TUE APR 7 2015
DOWNSTREAM BLOCKING OVER THE CANADIAN MARITIMES WILL BE RELAXING
OVER THE NEXT 48 HOURS. THIS WILL ALLOW ENERGY THAT HAS BEEN STALLED
UPSTREAM TO MIGRATE THROUGH THE NORTHERN HALF OF THE CONUS THIS
WEEK. THE STORM OF INTEREST TO OUR REGION REMAINS STUCK OFF THE
OREGON COAST WITH NO SIGNIFICANT HEIGHT FALLS SEEN IN HAND ANALYSIS
THIS MORNING. GOES DERIVED IMAGERY ALSO SUGGESTS PACIFIC MOISTURE
TAP IS WEAK WITH THE BULK OF THE MOISTURE WELL TO OUR SOUTH AND
HEADED TO THE PLAINS THROUGH THE WEEK. WATER VAPOR DOES INDICATE A
STRONGER BRANCH OF THE JET ROUNDING THE BASE OF THE LOW IN CENTRAL
CALIFORNIA THIS MORNING WHICH WILL HELP PULL THE SYSTEM ON SHORE
THROUGH THE AFTERNOON...MOVING TO THE WESTERN UTAH BORDER BY
WEDNESDAY. THIS WILL KEEP A TIGHT SOUTHWEST GRADIENT IN PLACE AND
LEAD TO ANOTHER WINDY AND WARM DAY ACROSS THE CWA WHICH IS LIKELY
TO CONTINUE OVERNIGHT AND KEEP MID-SLOPES MIXED AND POSSIBLY SOME
VALLEYS FOR MILD LOW TEMPERATURES.
QG FIELDS SUGGEST THE CORE OF THIS STORM WILL PASS TO OUR NORTH.
HOWEVER DECENT LARGE SCALE ASCENT STILL OCCURS OVER OUR NORTHERN CWA
THANKS TO A CYCLONICALLY CURVED JET TRANSLATING ACROSS WESTERN
COLORADO CONCURRENTLY WITH THE TROUGH PASSAGE TOMORROW AFTERNOON. A
COLD FRONT WILL BE REFLECTED AT THE SURFACE JUST AHEAD OF THE UPPER
TROUGH PASSAGE AND HELP SOME LOW LEVEL CONVERGENCE. HOWEVER STILL
FEEL MOISTURE...OR LACK THERE OF...IS THE MAIN INGREDIENT LACKING
FOR A DECENT PRECIPITATION EVENT. MODEL PWAT OUTPUT REMAINS AOB ONE
QUARTER OF AN INCH THROUGH THIS EVENT AND ENSEMBLE ANOMALIES HAVE
SHOWN THIS DRIER THAN NORMAL TREND FOR THE PAST SEVERAL DAYS. THERE
WILL BE SOME OCTANE IN THE FORM OF CONDITIONAL INSTABILITY WHICH MAY
TEMPORARILY BOOST PRECIPITATION RATES BUT ANTICIPATE THIS WILL BE
VERY LOCALIZED. THE BIGGER IMPACT WILL BE THE COOLER AIR DIVING
IN BEHIND THE FRONT. SIMILAR TO LAST WEEK...TEMPERATURES WILL BE
FALLING QUICKLY THROUGH THE LATE AFTERNOON AND EVENING AND SET THE
STAGE FOR A COLD MID TO LATE WEEK PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 445 AM MDT TUE APR 7 2015
H5 TROF AXIS WILL BE PASSING THROUGH THE FORECAST AREA WEDNESDAY
NIGHT WITH STRONG CAA IN PLACE. SNOW LEVELS ARE EXPECTED TO DROP
TO THE HIGHER VALLEY FLOORS OR AROUND THE 6K LEVEL...WITH BEST
MOISTURE AND FORCING GENERALLY ALONG AND NORTH OF INTERSTATE 70.
ACCUMULATING SNOWFALL WILL FAVOR THE EASTERN UINTA MOUNTAINS IN
NORTHEAST UTAH AND THE PARK AND GORE RANGES IN NORTHERN COLORADO.
LATEST NAM12 RUN IS SUPER AGGRESSIVE WITH SNOWFALL AMOUNTS ACROSS
THE EASTERN UINTAS WHERE 30+ INCHES FORECAST. MODEL IS LIKELY
SUFFERING WITH SOME CONVECTIVE FEEDBACK PROBLEMS AND WILL
BASICALLY THROW THAT SOLUTION OUT. REMAINING MODELS MORE
REASONABLE WITH ACCUMULATIONS IN THIS AREA WITH LATE SEASON
ADVISORIES POSSIBLE WITH CONVECTIVELY ENHANCED ACCUMULATIONS UP TO
6 INCHES POSSIBLE FOR THE 24 HOUR PERIOD BEGINNING WEDNESDAY
NIGHT.
SYSTEM CLEARS OUT THURSDAY NIGHT WITH DRY CONDITIONS MOVING BACK
IN. THE EXCEPTION WILL BE ACROSS THE FAR NORTHERN ZONES AS A WEAK
SYSTEM TRACKS ENE ACROSS IDAHO AND NORTHERN WYOMING FRIDAY. TAIL
END OF ENERGY MAY KICK OFF A FEW LIGHT SHOWERS OVER THE HIGHER
TERRAIN ALONG THE WYOMING STATE LINE...OTHERWISE MINIMAL IMPACT
ANTICIPATED. PATTERN FLATTENS OUT A BIT OVER THE WEEKEND AND INTO
EARLY NEXT WEEK WITH ADDITIONAL ENERGY CLIPPING THE NORTHERN
MOUNTAINS LATE SATURDAY AND SUNDAY. ELSEWHERE...DRY CONDITIONS ARE
EXPECTED TO CONTINUE.
TEMPERATURES WILL BE DROPPING QUICKLY WEDNESDAY NIGHT BEHIND THE
FRONT...WITH FREEZING CONDITIONS POSSIBLE IN THE LOWER VALLEYS
WHERE FRUIT TREES AND OTHER TENDER VEGETATION COULD BE THREATENED.
AS A RESULT...WILL BE ISSUING A FREEZE WATCH FOR LATE WEDNESDAY
NIGHT THROUGH EARLY THURSDAY MORNING. SIMILAR TEMPS POSSIBLE
THURSDAY NIGHT...BEFORE TEMPS START MODIFYING OVER THE WEEKEND.
BIG QUESTION WITH THE FREEZE WATCH IS THE AMOUNT OF CLOUD COVER
THAT MAY LINGER OVER THE REGION. THIS WOULD LIMIT THE COLDEST
TEMPS TO JUST A FEW HOURS AROUND SUNRISE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1059 AM MDT TUE APR 7 2015
GUSTY SOUTHWEST SURFACE WINDS AND TURBULENCE ALOFT WILL LIKELY BE
THE MAIN AVIATION HAZARDS THIS AFTERNOON AND EVENING. EXPECT
SOUTHWEST WINDS GUSTING BETWEEN 30-40 KTS AT TIMES UNTIL 03Z AT MANY
VALLEY LOCATIONS INCLUDING THE TAF SITES. THE WIND MAY KICK UP SOME
AREAS OF BLOWING DUST...ALTHOUGH WIDESPREAD RESTRICTIONS TO
VISIBILITY. UPPER LEVEL LOW PRESSURE ALONG THE CA COAST WILL MOVE TO
ABOUT NE UT BY MIDDAY WED. CLOUDS WILL INCREASE AFTER 06Z TONIGHT
WITH BASES LOWERING WED MORNING BUT REMAINING VFR AT THE TAF SITES
THROUGH 18Z. MVFR CONDITIONS IN SCT -SHSN ARE POSSIBLE OVER THE ERN
UINTA MTNS AND THE NW CO MTNS AFTER 12Z WED.
&&
.FIRE WEATHER...
ISSUED AT 445 AM MDT TUE APR 7 2015
...CRITICAL FIRE WEATHER CONDITIONS CONTINUE INTO WEDNESDAY...
STRONG SOUTHWEST GRADIENT WINDS WILL CONTINUE ALOFT AND WILL
EASILY MIX TO THE SURFACE AS TEMPERATURES REMAIN ABOVE NORMAL AND
INSTABILITY STRONG. THE AIR MASS REMAINS VERY DRY WITH AFTERNOON
HUMIDITY VALUES RANGING FROM 5 TO 15 PERCENT AND POOR RECOVERY
EXPECTED AGAIN TONIGHT. SOME MOISTURE WILL SPREAD INTO THE AREA
ON WEDNESDAY BUT COOLER AIR ARRIVING WILL BE THE MAIN FACTOR FOR
HELPING INCREASE HUMIDITY. VIRGA IS LIKELY TO PROCEED ANY
PRECIPITATION ON WEDNESDAY AND HELP CREATE LOCALLY STRONG WIND
GUSTS THROUGH THE AFTERNOON. COLORADO ZONE 207 HAS THE POTENTIAL
TO REACH CRITICAL FIRE WEATHER CONDITIONS FOR LOW HUMIDITY AND
GUSTY WINDS AHEAD OF THE FRONT WEDNESDAY AFTERNOON. COOLER AND
WETTER CONDITIONS ARE EXPECTED WEDNESDAY EVENING THROUGH THURSDAY
NIGHT FAVORING THE NORTH. THE NEXT CHANCE OF SHOWERS ARRIVES SATURDAY
NIGHT INTO MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
FOR COZ006-011-020.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR
COZ200-202-203-205-207-290-292.
UT...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
FOR UTZ022-027.
&&
$$
UPDATE...JAD
SHORT TERM...15
LONG TERM...JDC
AVIATION...JAD
FIRE WEATHER...TGJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT MON APR 6 2015
.UPDATE...
ISSUED AT 903 PM MDT MON APR 6 2015
UPDATED FOR EXPIRATION OF RED FLAG WARNING. RH STILL VERY LOW MOST
LOCATIONS...BUT WINDS HAVE DIMINISHED ENOUGH TO LET WARNING EXPIRE
ON SCHEDULE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 245 PM MDT MON APR 6 2015
...SHORT TERM CONCERN REMAINS CRITICAL FIRE WEATHER CONDITIONS...
CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING A DEEP
SOUTHWESTERLY FLOW PATTERN ACROSS THE REGION WITH AN UPPER LOW AND
BROAD TROUGH JUST OFFSHORE THE PAC NORTHWEST COAST THROUGH THE WEST
COAST AND GREAT BASIN REGION. WATER VAPOR IMAGERY ALSO INDICATING AN
EMBEDDED SHORT WAVE TRANSLATING ACROSS THE GREAT BASIN AT THIS TIME.
LATEST SFC OBSERVATIONS INDICATING A WELL MIXED ATMOSPHERE ACROSS
THE AREA WITH BREEZY TO WINDY SOUTHWEST WINDS...WARM TEMPERATURES IN
THE 70S TO LOWER 80S LOWER ELEVATIONS...50S AND 60S ACROSS THE
HIGHER TERRAIN...DEW PTS MAINLY IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO...ALL LEADING TO DANGEROUS FIRE WEATHER CONDITIONS BEING
EXPERIENCED ACROSS ALL OF THE NON SNOW COVERED AREAS OF SOUTH CENTRAL
AND SOUTHEAST COLORADO.
HOWEVER...LOW LEVEL MOISTURE IS NOT TOO FAR AWAY WITH REGIONAL
RADARS INDICATING A FINE LINE FROM NEAR DIA TO BURLINGTON AND INTO
WEST CENTRAL KANSAS...WITH DEW PTS IN THE 20S...30S AND 40S NORTH
AND EAST OF THE BOUNDARY INTO NORTHEASTERN COLORADO AND NORTHWESTERN
KANSAS.
TONIGHT AND TOMORROW...MODERATE TO STRONG SW FLOW ALOFT PROGGED TO
CONTINUE ACROSS THE AREA THROUGH THE PERIOD WITH GREAT BASIN
EMBEDDED WAVE CONTINUING TO TRANSLATE NORTH AND EAST ACROSS THE
NORTHERN ROCKIES TONIGHT AND ANOTHER SHORT WAVE PROGGED TO MOVE INTO
THE GREAT BASIN REGION THROUGH THE DAY TOMORROW. FIRST WAVE LOOKS TO
HELP PUSH LOW LEVEL MOISTURE GRADIENT/FRONT SOUTH AND WEST ACROSS
PORTIONS OF THE PALMER DVD AND NORTHERN PORTIONS OF THE SE PLAINS
TONIGHT WITH THE HRRR THE MOST AGGRESSIVE PUSHING MID 40 DEW PTS AND
STRATUS WELL INTO KIOWA AND PROWERS COUNTIES OVERNIGHT...WHICH MAY
BE A TAD OVERDONE. FURTHER WEST...WILL LIKELY SEE POOR RH RECOVERY
WITH LOWS SIMILAR TO LAST NIGHTS.
THIS BOUNDARY LOOKS TO MIX OUT THROUGH THE LATE MORNING AND EARLY
AFTERNOON TOMORROW AS LEE TROUGH STRENGTHENS ACROSS THE EASTERN
PLAINS AHEAD OF THE NEXT EMBEDDED SHORT WAVE. THIS ALL POINTS TO
ANOTHER DAY OF HIGH FIRE DANGER...ESPECIALLY FOR AREAS ALONG THE I-
25 CORRIDOR AND BACK WEST ACROSS THE REST OF THE EASTERN MTS TO THE
CONTDVD. WITH THAT SAID...HAVE UPGRADED AND EXPANDED A RED FLAG
WARNING FOR TOMORROW FROM NOON TO 8 PM FOR ALL OF THE NON SNOW
COVERED MTS...THE HIGH MT VALLEY AND THROUGH THE I-25 CORRIDOR. I
DID NOT INCLUDE THE FAR SE PLAINS WITH MARGINAL WINDS...THOUGH IF
DEEP ENOUGH MIXING CAN OCCUR...COULD SEE RED FLAG CONDITIONS THERE
AS WELL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 245 PM MDT MON APR 6 2015
...DRY AND WINDY WEATHER CONTINUES...
A SERIES OF PROGRESSIVE TROUGHS WILL IMPACT OUR AREA OVER THE NEXT
SIX TO TEN DAYS...UNFORTUNATELY NONE OF THEM LOOK VERY ORGANIZED AND
IT LOOKS LIKE THERE WILL BE MORE WIND THAN PRECIPITATION FROM THIS
PATTERN. THE ONLY OPTIMISTIC THING THAT CAN BE SAID IS THAT THE
MODELS ARE STRUGGLING WITH THE PATTERN...SO THERE IS TIME FOR IT TO
CHANGE.
WEDNESDAY STILL LOOKS LIKE A DAY OF POTENTIALLY EXTREME FIRE
WEATHER. WITH INCREASING WRLY FLOW ALOFT...WILL SEE VERY LOW RH OVER
MOST OF THE AREA...AND ANOTHER ROUND OF STRONG-GUSTY WINDS IN THE
AFTERNOON AND EARLY EVE. HAVE HOISTED A FIRE WX WATCH FOR MOST OF
THE CWA. ONLY AREAS THAT MIGHT ESCAPE ARE THE PIKES PEAK REGION AND
THE CENTRAL MTS. TEMPS ALOFT WILL BE FALLING...SO DEPENDING ON THE
SPEED OF THE COLD FRONT THE RH VALUES FOR THE NRN AND CENTRAL MTN
AREAS MAY BE HIGH ENOUGH TO PRECLUDE RED FLAG. BUT IT WILL BE
ANOTHER DAY OF HIGH FIRE DANGER FOR THE PLAINS. EXTREME NERN
CORNER...BASICALLY KIOWA COUNTY...WILL BE A BIT SLOWER TO MIX OUT
DUE TO SOME MORNING LOW CLOUDS...BUT BY MID TO LATE AFTERNOON MOST
OF THE PLAINS SHOULD BE ON THE BREEZY-WINDY SIDE.
MODELS ARE NOW ALL ON BOARD WITH A MORE NORTHERLY TRACK FOR THE LATE
WED-THU SYSTEM. AS EXPECTED...THE OUTLIER ECMWF HAS FALLEN INTO LINE
WITH THE GFS...AND THE NAM-GFS SOLUTION HAS COME TOGETHER WITH A LOW
THAT TRACKS THROUGH WY. SO...PRECIP CHANCES NOT LOOKING VERY GOOD
FOR US RIGHT NOW. STILL LOOKS LIKE THE PIKES PEAK REGION AND CENTRAL
MTS N OF HGWY 50 WILL GET SOME SNOW...PERHAPS A COUPLE INCHES. BUT
ELSEWHERE...HAVE TRIMMED BACK THE LOW POPS AND WILL KEEP THEM SILENT
FOR NOW. TEMPS OVER THE PLAINS ON THU SHOULD BE MAINLY IN THE UPPER
50S-LOWER 60S.
RIDGING ON FRIDAY SHOULD MITIGATE FIRE WX CONCERNS...AS WINDS DIE
DOWN FOR A DAY OR SO. BUT IT STILL LOOKS DRY...AS DOES SATURDAY WHEN
SWRLY FLOW PICKS UP ONCE AGAIN AND LEADS TO MORE FIRE WX CONCERNS.
NEXT SYSTEM IS STILL BEING HANDLED QUITE DIFFERENTLY BY THE GLOBAL
MODELS. MODELS ARE ALL SHOWING A SPLIT SYSTEM...BUT THE GFS HAS A
WEAKER CUTOFF...AND BROAD DISORGANIZED CUTOFF LOW OVER NRN CO AND WY
BY MONDAY. THE ECMWF HAS A MORE ZONAL PATTERN TO OUR NORTH...BUT
KEEPS THE SRN CUTOFF SYSTEM TOO FAR SOUTH TO IMPACT OUR AREA.
NEITHER 12Z SOLUTION WOULD BRING US MUCH PRECIPITATION...WE JUST CAN
NOT GET A BREAK FROM THIS DISORGANIZED PATTERN! STILL...IT LOOKS
LIKE A CONTINUED PERIOD OF UNSETTLED WEATHER WITH SHOWERS PROBABLE
FOR AT LEAST THE MTN AREAS. ROSE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM MDT MON APR 6 2015
VFR CONDITIONS IN COMBINATION WITH GUSTY WINDS AT TIMES ARE
ANTICIPATED OVER THE KALS...KCOS AND KPUB TAF SITES INTO TUESDAY
EVENING AS DRY SOUTHWESTERLY UPPER FLOW REMAINS OVER THE REGION.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR COZ222-224>237.
RED FLAG WARNING FROM NOON TO 8 PM MDT TUESDAY FOR COZ220>230-
233.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
358 AM EDT TUE APR 7 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL PROGRESS SOUTHWARD THROUGH THE AREA
TODAY. THIS FRONT WILL STAY TO OUR SOUTH TONIGHT THROUGH THURSDAY.
MEANWHILE, HIGH PRESSURE BUILDING IN FROM EASTERN CANADA WILL BE
ACCOMPANIED BY PERSISTENT ONSHORE FLOW IN THE MID-ATLANTIC REGION.
THE SAME FRONTAL BOUNDARY IS EXPECTED TO RETURN BACK NORTHWARD AS A
WARM FRONT ON FRIDAY BEFORE A COLD FRONT MOVES THROUGH FRIDAY NIGHT.
HIGH PRESSURE BUILDS INTO THE REGION THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CDFNT WILL WORK ITS WAY SWD OVER THE REGION THRU THE COURSE OF
THE DAY TODAY AND BRING SHOWERS WITH IT.
LATEST RADAR SHOWED SOME PRECIP W OF BALTIMORE WITH SOME DEVELOPING
IN SRN NJ AND ADDITIONAL PRECIP OVER THE POCONOS. HRRR GUID IS
ONLY PICKING UP THE LARGER AREA W OF BALTIMORE REALLY WELL AND WANTS
TO LESSEN IT/DISSIPATE IT AS IT MOVES EWD. HRRR STILL WANTS TO HOLD
OFF THE BULK OF THE PRECIP, AS DO THE REST OF THE MDLS UNTIL AFTER
DAYBREAK.
STLT IMAGERY AND SFC OBS STILL HAVE HIGH TO MID LEVEL CLOUDS AND THE
AMS IS RELATIVELY DRY, SO HAVE GONE WITH THE TREND AND HAVE PLACED
SOME LOW POPS ERLY WAND HIGHER POPS A BIT LATER THAN THE PREV FCST.
OVERALL, TODAY LOOKS TO BE A CLOUDY AND WARM DAY WITH GENLY PDS OF
LIGHT RAIN.
THE WIND WILL START OFF SWLY IN THE MRNG AND BECOME MORE NELY LATER
IN THE DAY, DEPENDING ON LOCATION, AS THE FRONT PASSES. ONCE THE
WIND SHIFTS, YOU WILL KNOW IT AS SW WIND IS GENLY WARM AND NE IS
NOT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE RAIN STAYS WITH US EARLY TONIGHT BEFORE ENDING. IT WILL
LIKELY BECOME MORE STRATIFORM AND COULD EVEN BE MORE OF A DRIZZLE.
IT LOOKS TO BE A FAIRLY DREARY NIGHT WITH A NE WIND AND WHATEVER
IS FALLING FROM THE SKY. PRECIP SHUD COME TO AN END LATE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A STRONG (BETWEEN 1035-1040 MB) SURFACE HIGH WILL BUILD EASTWARD
ACROSS QUEBEC ON WEDNESDAY. A CLASSIC CAD SETUP WILL BE IN PLACE
FOR THE MIDWEEK, INDICATIVE BY THE U-SHAPED MSLP PATTERN AS HIGH
PRESSURE RIDGES SOUTHWARD DOWN INTO MID-ATLANTIC REGION. FORECAST
MODEL SOUNDINGS PICK UP ON THE SHALLOW WEDGE OF COLD AIR NEAR THE
SURFACE THAT REMAINS TRAPPED ON THE EASTERN SIDE OF THE
APPALACHIANS. IN ADDITION TO THE BELOW NORMAL TEMPS, THIS PATTERN
WILL RESULT IN PLENTY OF CLOUDS ALONG WITH PERIODS OF LIGHT RAIN
AND DRIZZLE WEDNESDAY AND THURSDAY.
SOME OF THE COLDER MODEL GUIDANCE IS SHOWING THE POTENTIAL FOR
LIGHT FREEZING RAIN IN NORTHEAST PA AND FAR NORTHWEST NJ OVERNIGHT
WEDNESDAY INTO THE EARLY MORNING THURSDAY. THERE IS STILL
UNCERTAINTY THAT TEMPS FALL BELOW FREEZING AND THAT ICE ACCRETION
WOULD OCCUR IN THESE NORTHERN MOST ZONES. DENSE CLOUD COVER
SHOULD MINIMIZE RADIATIONAL COOLING AND CAA WILL BE ABSENT UNDER
AN EAST TO SOUTHEAST FLOW IN THE BOUNDARY LAYER. EVEN THE COLDEST
GUIDANCE HAS TEMPS HOVERING AROUND 32 DEGREES, WHICH WOULD BE
DIFFICULT FOR ICE TO ACCRETE ON ANYTHING OTHER THAN ELEVATED
SURFACES (TREES/ROAD SIGNS/POWERLINES) GIVEN HOW WARM THE GROUND
IS. NEVERTHELESS, THE NAM AND ABOUT HALF OF THE SREF MEMBERS
SUPPORT FREEZING RAIN ALONG AND NORTH OF I-80 LATE WEDNESDAY
NIGHT, SO IT WOULDN`T BE PRUDENT TO COMPLETELY DISMISS THE
POTENTIAL OF A LIGHT GLAZE.
SOUTHWEST FLOW WILL STRENGTHEN AHEAD OF AN APPROACHING COLD FRONT ON
FRIDAY. A MAJORITY OF THE LATEST MODEL GUIDANCE SHOWS THE CAD WEDGE
ERODING AND THE PRE-FRONTAL WARM SECTOR BECOMING ESTABLISHED OVER
THE FORECAST AREA. AS STATED BY YESTERDAY`S DAY SHIFT FORECASTER,
THE MODELS TEND TO BE TOO AGGRESSIVE WITH THE PROGRESSION OF WARM
FRONTS THIS TIME OF YEAR DUE TO THE PRESENCE OF THE COLD OCEAN
TEMPS. IN SOME CASES, THE CAD WEDGE DOES NOT ERODE UNTIL AFTER THE
COLD FROPA WHICH WOULDN`T BE UNTIL FRIDAY EVENING. THERE WILL
LIKELY BE A NOTICEABLE NORTH TO SOUTH TEMP GRADIENT ON FRIDAY
WITH HIGHS IN THE 70S SOUTH OF THE WARM FRONT AND 60S FARTHER
NORTH (EXCEPT 50S IN THE POCONOS/NORTHWEST NJ WHERE THE HILLY
TERRAIN WILL MAKE IT MORE DIFFICULT TO SCOUR OUT THE COLD). THERE
MAY BE AN OPPORTUNITY FOR THUNDERSTORMS TO DEVELOP IN THE WARM
SECTOR JUST AHEAD OF THE COLD FRONT DURING THE PEAK HEATING HOURS
ON FRIDAY. SPC OUTLOOK FROM YESTERDAY MORNING HAD PLACED A
PORTION OF THE DELMARVA IN A 15 PERCENT PROBABILITY FOR SEVERE
STORMS ON FRIDAY.
COOLER AIR WILL MOVE BEHIND THE COLD FRONT LATE FRIDAY NIGHT. THE
AIRMASS WILL NOT BE EXTREMELY COLD SO TEMPS SHOULD BE NEAR NORMAL
THIS WEEKEND. CANNOT RULE OUT A BRIEF SHOWER IN THE POCONOS WITH
THE PASSAGE OF AN UPPER TROUGH ON SATURDAY. OTHERWISE THE WEEKEND
SHOULD BE DRY AS HIGH PRESSURE BUILDS OVERHEAD.
HIGH PRESSURE MOVES OFFSHORE BY MONDAY. DESPITE RISING HEIGHTS
AND SOUTHERLY FLOW/WAA ALOFT, WARMING AT THE SURFACE WOULD BE
MODERATED BY THE ONSHORE FLOW FROM THE COOLER WATERS.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDS ARE HANGING ON LONGER THAN ANTICIPATED ERLY THIS MRNG
AND THE CURRENT FCST MAY BE TOO PESSIMISTIC. ITS PSBL THAT WE KEEP
THE VFR THRU DAYBREAK (OR EVEN LONGER IN SOME AREAS). HOWEVER, THE
OVERALL TREND IS STILL DOWNWARD LATER THIS MORNING, AS A FRONT
MOVES FROM N TO S ACRS THE AREA. CONDS WILL DROP FROM VFR TO MVFR
AND THEN TO IFR. SOME LIFR CAN NOT BE RULED OUT. ONCE CONDS DROP,
THEY WILL STAY DOWN THRU THE DAY AND INTO TONIGHT. VSBYS MAY
IMPROVE TO VFR BY MIDNIGHT OR SHORTLY THEREAFTER, BUT STILL EXPECT
THE LOW CIGS TO STICK AROUND.
WIND WILL START OUT FROM THE SW, GENLY LESS THAN 10 KTS, BUT WILL
SHIFT TO THE NE AND GUST TO AROUND 20 KT BY LATE AFTN ERLY EVE.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY NIGHT...BREEZY NE WINDS WINDS WILL
SUBSIDE A BIT AFTER WEDNESDAY. THE ONSHORE FLOW WILL RESULT IN A
PROLONGED STRETCH OF LOW CLOUDS AND PERIODS OF RA/DZ. EXPECT IFR
CIGS FOR MAJORITY OF THE PERIOD BUT DO SEE SOME OPPORTUNITY FOR
BRIEF IMPROVEMENTS TO MVFR DURING THE AFTERNOON HOURS EACH DAY.
ABOVE NORMAL CONFIDENCE.
FRIDAY...IFR CIGS IN THE MORNING IMPROVE TO MVFR AND THEN VFR FROM
SOUTH TO NORTH DURING THE DAY. CONFIDENCE IN THIS IMPROVEMENT
HIGHEST IN OUR SOUTHERN TERMINALS. SW WINDS WILL BE GUSTY. SHOWERS
AND POSSIBLY A THUNDERSTORMS WITH A COLD FROPA FRIDAY AFTN/EVE.
SATURDAY...VFR AND BREEZY NW WINDS.
&&
.MARINE...
THE SCA IN EFFECT FOR ERLY THIS MRNG HAS BEEN CANCELLED AS CONDS
REMAIN BELOW CRITERIA. CONDS WILL REMAIN BELOW CRITERIA FOR TODAY
AND MOST OF TONIGHT. THE WIND WILL SHIFT FROM SW TO NE BE LATE
AFTN/ERLY EVE N AND OVERNIGHT S. AND WIND SPEED WILL INCREASE TO
NEAR ADVY CRITERIA BY THE END OF THE PD WITH SEAS RESPONDING IN
KIND.
OUTLOOK...
WEDNESDAY...POTENTIAL FOR GALES, PARTICULARLY IN THE COASTAL
WATERS ADJACENT TO CENTRAL NJ AND DURING THE MORNING HOURS. A GALE
WATCH WAS ISSUED FOR OUR TWO NORTHERN MOST ZONES. ISSUED A SCA FOR
OUR COASTAL ZONES FARTHER SOUTH WHERE NELY WINDS WILL BE SLIGHTLY
WEAKER. WENT 1-2 FT ABOVE WAVEWATCH GUIDANCE FOR WAVE HEIGHTS
BASED ON KNOWN MODEL BIAS IN NE FLOW.
WEDNESDAY NIGHT AND THURSDAY...NELY WINDS DIMINISH BUT MAY STILL BE
NEAR 25 KT OFF THE NJ COAST. SCA STILL EXPECTED TO PERSIST FOR ALL
COASTAL ZONES WITH CHOPPY SEAS OF 5-8 FT.
FRIDAY...SWLY WINDS STRENGTHEN AND SCA CONDITIONS EXPECTED BY
AFTERNOON. 40-50 KT WINDS ARE FORECAST TO DEVELOP NOT TOO FAR ALOFT
BUT VERY WARM AIR MOVING ATOP THE COLDER WATERS DO NOT FAVOR
THESE WINDS TO MIX DOWN TO THE SURFACE.
FRIDAY NIGHT AND SATURDAY...WINDS BECOME NWLY BEHIND COLD FROPA
SHOULD GUST TO UNDER 25 KT. SEAS 4-6 FT FRIDAY NIGHT WILL SUBSIDE TO
4 FT OR LESS BY SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
ANZ452>455.
GALE WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR ANZ450-451.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...KLEIN/NIERENBERG
MARINE...KLEIN/NIERENBERG
AREA FORECAST DISCUSSION
NWS MIAMI FL
138 PM EDT TUE APR 7 2015
.AVIATION...
HIGH PRESSURE CONTINUES TO KEEP THE WEATHER QUIET ACROSS SOUTH
FLORIDA. ALTHOUGH, THERE MAY BE SOME ISOLATED SHOWERS OVER THE
WESTERN HALF, NEAR KAPF. THERE IS ALSO A VERY SLIGHT POSSIBILITY
THAT A FEW OF ANY SHOWERS THAT ARE ABLE TO DEVELOP, MAY TURN INTO
A THUNDERSTORM. HOWEVER, THE UNCERTAINTY IS LOW ENOUGH THAT NO
MENTION OF EVEN THE SHOWERS ARE IN THE TAFS AT THIS TIME. SKIES
SHOULD BECOME MOSTLY CLEAR TO CLEAR TONIGHT. TOMORROW WILL SEE
ANOTHER ROUND OF AFTERNOON CLOUDS DEVELOP.
&&
.PREV DISCUSSION... /ISSUED 1118 AM EDT TUE APR 7 2015/
UPDATE...
JUST MADE A QUICK CHANGE TO ADD A SLIGHT CHANCE OF THUNDER OVER
THE INTERIOR AND WEST COAST FOR LATE THIS AFTERNOON AND EARLY
EVENING. THIS BASED ON CLOSER EXAMINATION TO THE MORNING SOUNDING
AND DECIDED THE AIRMASS IS SHOWING ENOUGH INSTABILITY THAT CANNOT
RULE OUT A POSSIBLE LIGHTNING STRIKE.
PREV DISCUSSION... /ISSUED 902 AM EDT TUE APR 7 2015/
UPDATE...
CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF
OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE
ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING
UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL
QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE
EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY
OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL
SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING
SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS
ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS
EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION.
KOB
PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/
DISCUSSION...
ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY
THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND
LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND
WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY.
SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY
THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST.
SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE
DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST
OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE
10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN
ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE
PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS
MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE
BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF
THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE
EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO
THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE
ALSO POSSIBLE FOR THE EAST COAST.
A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON
WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY
ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE
ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE
LIMITED.
MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON
THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE
GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT
INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH
EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE
TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND
GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE
BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF
COAST.
AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY
SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING
ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE
SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS
THEN RETURNING TO THE REGION.
MARINE...
AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH
SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF
WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 85 73 85 / 10 10 0 10
FORT LAUDERDALE 73 83 73 84 / 10 10 0 10
MIAMI 72 85 73 86 / 10 10 0 10
NAPLES 69 89 68 89 / 20 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....84/AK
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
1118 AM EDT TUE APR 7 2015
.UPDATE...
JUST MADE A QUICK CHANGE TO ADD A SLIGHT CHANCE OF THUNDER OVER
THE INTERIOR AND WEST COAST FOR LATE THIS AFTERNOON AND EARLY
EVENING. THIS BASED ON CLOSER EXAMINATION TO THE MORNING SOUNDING
AND DECIDED THE AIRMASS IS SHOWING ENOUGH INSTABILITY THAT CANNOT
RULE OUT A POSSIBLE LIGHTNING STRIKE.
&&
.PREV DISCUSSION... /ISSUED 902 AM EDT TUE APR 7 2015/
UPDATE...
CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF
OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE
ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING
UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL
QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE
EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY
OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL
SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING
SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS
ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS
EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION.
KOB
PREV DISCUSSION... /ISSUED 811 AM EDT TUE APR 7 2015/
AVIATION...
HIGH PRESSURE WILL BE BUILDING OVER THE AREA, WITH THE CENTER NEAR
BERMUDA. THIS WILL KEEP THE GENERAL FLOW OUT OF THE EAST TODAY.
SOME ISOLATED SHOWERS MAY BE POSSIBLE ALONG THE GULF COAST. A WEAK
UPPER LEVEL TROUGH WILL MOVE OVER SOUTH FLORIDA TONIGHT, BRINGING
AT LEAST AN INCREASE IN CLOUD COVER. SOME MODELS ARE INDICATING
THE CIGS COULD BE BORDERING ON IFR AT SOME OF THE ATLANTIC TAF
SITES, BEGINNING AFTER 02Z. HOWEVER, WITH LOW CONFIDENCE OF THE
IFR CONDITIONS, KEPT THE TAF STATING VFR AT THIS TIME.
PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/
DISCUSSION...
ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY
THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND
LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND
WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY.
SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY
THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST.
SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE
DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST
OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE
10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN
ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE
PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS
MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE
BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF
THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE
EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO
THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE
ALSO POSSIBLE FOR THE EAST COAST.
A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON
WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY
ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE
ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE
LIMITED.
MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON
THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE
GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT
INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH
EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE
TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND
GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE
BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF
COAST.
AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY
SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING
ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE
SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS
THEN RETURNING TO THE REGION.
MARINE...
AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH
SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF
WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 85 73 / 10 10 10 0
FORT LAUDERDALE 83 73 83 73 / 10 10 10 0
MIAMI 86 72 85 73 / 10 10 10 0
NAPLES 87 69 89 68 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
902 AM EDT TUE APR 7 2015
.UPDATE...
CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF
OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE
ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING
UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL
QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE
EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY
OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL
SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING
SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS
ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS
EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION.
KOB
&&
.PREV DISCUSSION... /ISSUED 811 AM EDT TUE APR 7 2015/
AVIATION...
HIGH PRESSURE WILL BE BUILDING OVER THE AREA, WITH THE CENTER NEAR
BERMUDA. THIS WILL KEEP THE GENERAL FLOW OUT OF THE EAST TODAY.
SOME ISOLATED SHOWERS MAY BE POSSIBLE ALONG THE GULF COAST. A WEAK
UPPER LEVEL TROUGH WILL MOVE OVER SOUTH FLORIDA TONIGHT, BRINGING
AT LEAST AN INCREASE IN CLOUD COVER. SOME MODELS ARE INDICATING
THE CIGS COULD BE BORDERING ON IFR AT SOME OF THE ATLANTIC TAF
SITES, BEGINNING AFTER 02Z. HOWEVER, WITH LOW CONFIDENCE OF THE
IFR CONDITIONS, KEPT THE TAF STATING VFR AT THIS TIME.
PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/
DISCUSSION...
ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY
THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND
LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND
WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY.
SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY
THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST.
SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE
DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST
OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE
10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN
ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE
PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS
MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE
BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF
THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE
EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO
THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE
ALSO POSSIBLE FOR THE EAST COAST.
A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON
WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY
ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE
ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE
LIMITED.
MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON
THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE
GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT
INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH
EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE
TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND
GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE
BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF
COAST.
AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY
SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING
ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE
SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS
THEN RETURNING TO THE REGION.
MARINE...
AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH
SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF
WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 85 73 / 10 10 10 0
FORT LAUDERDALE 83 73 83 73 / 10 10 10 0
MIAMI 86 72 85 73 / 10 10 10 0
NAPLES 87 69 89 68 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 AM EDT TUE APR 7 2015
.AVIATION...
EASTERLY WINDS AROUND 10 KNOTS WILL CONTINUE OVERNIGHT TONIGHT
ALONG THE EAST COAST...WITH LIGHT AND VARIABLE WINDS AT KAPF.
EARLIER RAINFALL AT KAPF MAY LEAD TO LOWER CIGS OVERNIGHT.
EASTERLY FLOW WILL INCREASE TO 12-15 KNOTS DURING THE DAY ON
TUESDAY. ANOTHER SUBTLE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE
PENINSULA LATE IN THE DAY ON TUESDAY...WHICH MAY LEAD TO SHOWERS
MAINLY NORTH OF KAPF. THERE WILL BE AN INCREASE IN LOW LEVEL
MOISTURE TOWARDS THE EAST COAST AROUND 00Z...AND MVFR CIGS ARE
POSSIBLE NEAR THE END OF THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 830 PM EDT MON APR 6 2015/
UPDATE...
CONVERGENCE BETWEEN EASTERLIES AND THE GULF COAST SEA BREEZE,
ALONG WITH A VERY SUBTLE WAVE DROPPING SOUTHEAST FROM THE
NORTHEASTERN GULF, PROVIDED JUST ENOUGH LIFT FOR SHOWERS ALONG
INLAND COLLIER THIS EVENING, MUCH LESS THAN WHAT THE HRRR HAS
PREDICTED. THIS CLUSTER COULD MAKE IT TO PART OF NAPLES OVER THE
NEXT FEW HOURS WHILE WEAKENING. OTHERWISE, COASTAL CONVERGENCE,
MINIMAL DIRECTIONAL SHEAR THROUGH H7, AND EAST WINDS 10-15KT WILL
BE ENOUGH FOR AT LEAST SLT CHC POPS OFFSHORE AND ALONG THE ENTIRE
EAST COAST FOR THE REST OF TONIGHT.
PREV DISCUSSION... /ISSUED 742 PM EDT MON APR 6 2015/
AVIATION...
ISOLATED SHOWERS REMAIN ACROSS THE ATLANTIC WATERS EARLY THIS
EVENING. AS EASTERLY FLOW PERSISTS THROUGH THE NIGHT...SOME OF
THESE SHOWERS COULD BRIEFLY AFFECT THE EAST COAST SITES BUT NOT
CONFIDENT ENOUGH TO MENTION IN TAFS. MAINLY DRY CONDITIONS
EXPECTED ON TUESDAY WITH EASTERLY FLOW PREVAILING.
PREV DISCUSSION... /ISSUED 237 PM EDT MON APR 6 2015/
SHORT TERM (TONIGHT-WEDNESDAY NIGHT)...
THE SHORT TERM PERIOD LOOKS RATHER SUBDUED AS A MID/UPPER LEVEL
RIDGE AXIS REMAINS ACROSS THE EASTERN GULF OF MEXICO. THIS RIDGE
WILL AMPLIFY LATE TUESDAY INTO WEDNESDAY IN RESPONSE TO A STRONG
TROUGH MOVING ONTO THE NORTHERN CALIFORNIA COAST AND INTO THE
CENTRAL ROCKIES. A SURFACE HIGH PRESSURE RIDGE CURRENTLY LOCATED
ACROSS THE SOUTHEAST STATES WILL ALSO MOVE LITTLE PROVIDING SOUTH
FLORIDA WITH A GENERAL LOW LEVEL EAST TO SOUTHEAST FLOW. FORECAST
SOUNDINGS SUGGEST THAT THIS PATTERN WILL BE FAVORABLE FOR A FEW
ATLANTIC SHOWERS TO MOVE ONSHORE ALONG THE SOUTHEAST COAST THROUGH
THIS PERIOD WITH A FEW AFTERNOON SHOWERS OVER THE INTERIOR AND WEST
COAST.
LONG TERM (THURSDAY-MONDAY)...
THE AMPLIFIED MID LEVEL RIDGE WILL CONTINUE THROUGH FRIDAY AND THEN
WEAKEN AND SHIFT BACK TO THE SOUTH OVER THE WEEKEND AS A POTENT
TROUGH MOVES THROUGH THE CENTRAL PLAINS. AS THIS PATTERN SHIFT
OCCURS, FORECAST SOUNDINGS SHOW SOME MOISTURE INCREASE WITH PWAT
CLIMBING TO AROUND 1.5" WHICH IS RUNNING ABOVE NORMAL FOR GOING INTO
THE MIDDLE OF APRIL. IN ADDITION, THERE WILL ALSO BE SOME
DESTABILIZATION OCCURRING AS 500MB TEMPERATURES COOL SLIGHTLY. THE
CENTRAL PLAINS TROUGH THEN LIFTS TO THE NORTHEAST EARLY NEXT WEEK
WITH THE RIDGE AMPLIFYING TO THE NORTH ONCE AGAIN.
MARINE...
AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH
SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF
WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 72 85 71 / 10 10 10 0
FORT LAUDERDALE 83 73 83 73 / 10 10 10 0
MIAMI 85 73 86 73 / 10 10 10 0
NAPLES 88 70 88 70 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1042 PM EDT WED APR 8 2015
.SYNOPSIS...
CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST
SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT
WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME
HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE
SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS
INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE
FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW
MOISTURE. MODERATE INSTABILITY LINGERING UNTIL AROUND 100 AM
SUPPORTS A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED
WITH THE SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED
DEVELOPMENT. USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY
IN THE MIDDLE 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS
SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE
CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW
LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE
ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL
CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER
FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE
MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION
POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME
TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE
WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND
BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE.
THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO
SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST
AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE
60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED
LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE
CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE
REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA
IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE
PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON
THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE
AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN
ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO
LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO
SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD
COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON
FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S
IN THE SOUTHEASTERN MIDLANDS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND
SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH
OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT
WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT
WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH
PRESSURE DOMINATING IN THE LOWER LEVELS.
EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW
CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP
SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE
POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH.
TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR
HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND
NEXT WEEK...AND ABOVE NORMAL LOWS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS
EXPECTED IN EARLY MORNING FOG ON THURSDAY.
SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO
THE SOUTHEASTERN STATES. WINDS WILL ONCE AGAIN BE LIGHT FROM THE
SOUTHWEST/SOUTH LATE THIS EVENING. MODELS SHOW POTENTIAL FOR FOG
DEVELOPMENT EARLY THURSDAY MORNING WITH LIGHT/CALM WIND...LOW
LEVEL MOISTURE IN PLACE...AND DRY AIR ALOFT. WILL MENTION FOG AT
AGS/DNL/OGB FROM 10Z THRU 14Z AND WILL CONTINUE TO UPDATE AS
CONFIDENCE INCREASES. VSBYS AT AGS MAY DIP TO IFR LEVELS BEFORE
14Z THURSDAY. DAYTIME HEATING AND MIXING SHOULD ALLOW VFR
CONDITIONS TO RETURN BY 14Z WITH MOSTLY SUNNY SKIES/PARTLY CLOUDY
THROUGH THE END OF THE TAF PERIOD. SCATTERED CONVECTION POSSIBLE
LATE THURSDAY AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO MENTION AT
ANY OF THE TAF SITES AT THIS TIME.
EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM
ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1041 PM EDT WED APR 8 2015
.SYNOPSIS...
CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST
SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT
WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME
HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE
SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS
INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE
FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW
MOISTURE. MODERATE INSTABILITY LINGERING INTO THE EVENING SUPPORTS
A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED WITH THE
SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED DEVELOPMENT.
USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY IN THE
MIDDLE 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS
SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE
CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW
LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE
ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL
CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER
FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE
MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION
POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME
TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE
WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND
BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE.
THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO
SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST
AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE
60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED
LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE
CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE
REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA
IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE
PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON
THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE
AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN
ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO
LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO
SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD
COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON
FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S
IN THE SOUTHEASTERN MIDLANDS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND
SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH
OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT
WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT
WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH
PRESSURE DOMINATING IN THE LOWER LEVELS.
EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW
CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP
SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE
POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH.
TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR
HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND
NEXT WEEK...AND ABOVE NORMAL LOWS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS
EXPECTED IN EARLY MORNING FOG ON THURSDAY.
SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO
THE SOUTHEASTERN STATES. WINDS WILL ONCE AGAIN BE LIGHT FROM THE
SOUTHWEST/SOUTH LATE THIS EVENING. MODELS SHOW POTENTIAL FOR FOG
DEVELOPMENT EARLY THURSDAY MORNING WITH LIGHT/CALM WIND...LOW
LEVEL MOISTURE IN PLACE...AND DRY AIR ALOFT. WILL MENTION FOG AT
AGS/DNL/OGB FROM 10Z THRU 14Z AND WILL CONTINUE TO UPDATE AS
CONFIDENCE INCREASES. VSBYS AT AGS MAY DIP TO IFR LEVELS BEFORE
14Z THURSDAY. DAYTIME HEATING AND MIXING SHOULD ALLOW VFR
CONDITIONS TO RETURN BY 14Z WITH MOSTLY SUNNY SKIES/PARTLY CLOUDY
THROUGH THE END OF THE TAF PERIOD. SCATTERED CONVECTION POSSIBLE
LATE THURSDAY AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO MENTION AT
ANY OF THE TAF SITES AT THIS TIME.
EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM
ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
729 PM EDT WED APR 8 2015
.SYNOPSIS...
CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST
SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT
WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME
HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE
SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS
INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE
FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW
MOISTURE. MODERATE INSTABILITY LINGERING INTO THE EVENING SUPPORTS
A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED WITH THE
SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED DEVELOPMENT.
USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY IN THE
MIDDLE 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS
SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE
CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW
LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE
ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL
CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER
FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE
MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION
POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME
TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE
WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND
BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE.
THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO
SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST
AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE
60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED
LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE
CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE
REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA
IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE
PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON
THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE
AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN
ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO
LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO
SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD
COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON
FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S
IN THE SOUTHEASTERN MIDLANDS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND
SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH
OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT
WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT
WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH
PRESSURE DOMINATING IN THE LOWER LEVELS.
EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW
CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP
SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE
POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH.
TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR
HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND
NEXT WEEK...AND ABOVE NORMAL LOWS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS
EXPECTED IN EARLY MORNING FOG ON THURSDAY.
SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO
THE SOUTHEASTERN STATES. LOW POTENTIAL FOR SEVERE CONVECTION THIS
EVENING. WINDS WILL ONCE AGAIN BE LIGHT FROM THE SOUTHWEST/SOUTH
TONIGHT. MODELS SHOW POTENTIAL FOR FOG DEVELOPMENT EARLY THURSDAY
MORNING WITH LIGHT/CALM WIND...LOW LEVEL MOISTURE IN PLACE...AND DRY
AIR ALOFT. HAVE ADDED MENTION OF FOG AT AGS/DNL/OGB FROM 10Z THRU
14Z AND WILL CONTINUE TO UPDATE AS CONFIDENCE INCREASES. VSBYS AT
AGS MAY DIP TO IFR LEVELS BEFORE 14Z THURSDAY. DAYTIME HEATING AND
MIXING SHOULD ALLOW VFR CONDITIONS TO RETURN BY 14Z WITH MOSTLY
SUNNY SKIES/PARTLY CLOUDY THROUGH THE END OF THE TAF PERIOD.
SCATTERED CONVECTION POSSIBLE LATE THURSDAY AFTERNOON...BUT NOT
ENOUGH CONFIDENCE TO MENTION AT ANY OF THE TAF SITES AT THIS TIME.
EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM
ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
351 AM EDT TUE APR 7 2015
.PREV DISCUSSION... /ISSUED 946 PM EDT MON APR 6 2015/
UPDATE...
FIRST WAVE OF SHOWERS CURRENTLY MOVING INTO NE GA. A SECOND
WAVE...ASSOCIATED WITH ANOTHER SHORTWAVE OVER WESTERN AL...IS
EXPECTED TO MOVE THROUGH THE AREA THROUGH THE EARLY MORNING HOURS.
NEWER RUNS OF THE HRRR HOLD THE SECOND AREA OF SHOWERS TOGETHER AS
IT MOVES ACROSS GA. WILL GO AHEAD AND KEEP THE SLIGHT CHANCE OF
THUNDER IN THE FORECAST...BUT INSTABILITY REMAINS WEAK.
PREV DISCUSSION... /ISSUED 736 PM EDT MON APR 6 2015/
PREV DISCUSSION... /ISSUED 349 PM EDT MON APR 6 2015/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A MOIST SOUTHERLY LOW LEVEL FLOW WILL CONTINUE OVER NORTH AND CENTRAL
GA THROUGH THE FORECAST PERIOD ALONG WITH A NEAR ZONAL FLOW ALOFT.
UPPER LEVEL DISTURBANCES OVER WEST TN AND SOUTH LA WILL MOVE EAST
DURING THE NEXT 24 HOURS. THESE SYNOPTIC FEATURES WILL COMBINE WITH
A WARM FRONT OVER THE GULF COAST GRADUALLY MOVING NORTH THROUGH THE
STATE TONIGHT. CONSEQUENTLY...SCATTERED SHOWERS AND THUNDERSTORMS
WILL PREVAIL LATE THIS AFTERNOON AND TONIGHT WITH RAINFALL AMOUNTS
FROM 0.25 TO 0.50 INCH. DO NOT EXPECT ANY SEVERE TSTMS WITH THE
MARGINAL INSTABILITY.
ANOTHER SHORT WAVE WILL BE PASSING OVER THE TN VALLEY ON TUESDAY
WITH THE BEST CHANCES OF TSTMS OVER EXTREME NORTH GA. HOWEVER...
DIURNAL HEATING IN THE UPPER 70S AND 80S WITH A MOIST SOUTHWEST
FLOW WILL TRIGGER SCATTERED TSTMS OVER THE REMAINDER OF NORTH AND
ALL OF CENTRAL GA. THE SHOWERS AND TSTMS WILL GRADUALLY DIMINISH
ON TUESDAY EVENING.
THE WARM AND MOIST GULF FLOW WITH THE EXPECTED CLOUD COVER WILL
HOLD MIN TEMPS TO AROUND 10 DEGREES ABOVE NORMAL TONIGHT AND TUESDAY
NIGHT. MAX TEMPS ON TUESDAY WILL BE FROM 5 TO 10 DEGREES ABOVE
NORMAL AS WELL. ACCEPTED AND MERGED MET/MAV MOS GUIDANCE FOR POPS
AND TEMPS.
16
LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. WEST TO SOUTHWEST
UPPER FLOW CONTINUING OVER THE FORECAST AREA THROUGH THE PERIOD.
SEVERAL WEAK IMPULSES CROSS THE STATE RESULTING IN A GENERALLY
UNSETTLED PATTERN. HAVE CONTINUED WITH A CHANCE OR SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS EACH DAY MOST AREAS. THE MOST
SIGNIFICANT SYSTEM SHOULD BE THE FRONT IN THE FRIDAY NIGHT THROUGH
SATURDAY PERIOD. SOME LIKELY POPS SEEM REASONABLE ALONG THE FRONT
FRIDAY. SOME DRYING INDICATED BEHIND THE FRONT FOR SATURDAY INTO
SUNDAY. HOWEVER...WITH SOME TIMING DIFFERENCES POSSIBLE FOR THAT
FAR OUT...HAVE LEFT IN A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS
FOR THOSE TIMES. TEMPERATURES SHOULD BE WARM THROUGH THE
WEEK...EXCEPT COOLING SOME FOR THE WEEKEND.
41/01
AVIATION...
18Z UPDATE...
VFR CEILINGS GENERALLY PREVAILED OVER NORTH AND CENTRAL GA
WITH SCATTERED SHOWERS AND TSTMS APPROACHING FROM THE WEST IN AL.
EXPECT THE SHOWERS AND TSTMS TO INCREASE OVER THE TAF SITES
THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING AS A WARM
FRONT MOVES NORTH THROUGH THE STATE TONIGHT. CEILINGS WILL
GRADUALLY LOWER TO IFR/MVFR AFTER MIDNIGHT THROUGH TUESDAY
MORNING. SURFACE WINDS WILL BE SOUTHEAST BECOMING SOUTHWEST ON
TUESDAY LESS THAN 10 KTS.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE FOR CEILINGS...VSBYS AND PRECIP TIMING.
HIGH CONFIDENCE FOR WINDS.
16
&&
.AVIATION...
06Z UPDATE...
IFR CIGS EXPECTED THROUGH MID MORNING...THEN IMPROVING
CONDITIONS...WITH VFR BY LATE MORNING. SE WINDS AT 5KT OR LESS
OVERNIGHT WILL INCREASE AND SHIFT TO THE SW BY MID MORNING. WINDS
SHOULD HOVER JUST WEST OF SOUTH THROUGH THE DAY. PROB30 STILL
INCLUDED FOR -TSRA FOR THE BEST AFTERNOON CHANCES...GENERALLY
17-23Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 79 60 84 63 / 30 20 30 20
ATLANTA 77 63 83 64 / 30 20 10 10
BLAIRSVILLE 73 56 79 59 / 50 20 40 20
CARTERSVILLE 78 59 84 62 / 30 20 20 10
COLUMBUS 83 64 86 64 / 20 10 10 10
GAINESVILLE 75 60 81 62 / 40 20 30 20
MACON 83 62 86 63 / 30 20 20 10
ROME 79 58 84 61 / 40 10 20 10
PEACHTREE CITY 80 58 83 62 / 20 10 10 10
VIDALIA 82 65 85 65 / 30 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....41
AVIATION...31
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
955 PM CDT WED APR 8 2015
.UPDATE...945 PM...
IMPROVED NEAR THE LAKESHORE THIS EVENING I AM
A BIT HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS
COULD FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS
THE WARM FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD
INTO THE COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG
COULD REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE
ADVISORY IN PLACE.
IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM
ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED
CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS
ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS
OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID-
LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS
LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS
SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM
FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED
TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A
RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL
LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE
DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT
WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL.
KJB
&&
.SHORT TERM...
322 PM CDT
THROUGH THURSDAY NIGHT...
QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER
POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING
TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE
MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING
WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE
MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY.
THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3
PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB
SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR
DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS
JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING
WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES
THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS
IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING
EASTWARD INTO THE OZARK REGION THIS AFTERNOON.
IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL
CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY
MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING.
ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS
EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT
LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND
OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED
LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND
STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND
SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR
AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO
CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE
REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR
STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO
OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR
STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY
WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED
LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH
ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE
THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN
SOUTH OF U.S. HIGHWAY 24.
AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS
OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO
CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION
IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE
FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S
THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS
POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY.
THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS
THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE
STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON
REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY
FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON
PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A
QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM
SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S
CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS
WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY
SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/.
HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS
THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN
OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO
CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY
STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT
LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON
THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE
AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL
FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW-
LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED
CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL
REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON
ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE
REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE.
STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING
WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS.
MTF
&&
.LONG TERM...
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH.
A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE
CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF
DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST
IL CLOSER TO THE VORTICITY MAXIMUM.
SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT
THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT
WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR
THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S
SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA.
SUNDAY... FORECAST CONFIDENCE HIGH.
SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN
ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY...
SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY.
LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH
PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY
SO I LEFT OUT THUNDER.
MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM.
MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO
CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS
ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO
EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS
SYSTEM AND IT WILL NEED TO BE WATCHED.
MRC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* MVFR/OCCL IFR VSBY WITH FOG TONIGHT.
* IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR
OVERNIGHT.
* SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND
ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING.
* SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA
MORE LIKELY THURS EARLY EVENING.
KMD
//DISCUSSION...UPDATED 00Z...
IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM
CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT.
ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS
CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN
AGAIN THURSDAY AFTERNOON.
WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN
AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR
CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER
MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF
THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS
HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE
TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS
CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER
DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS
ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL
SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME
AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO
TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM
FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR
SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT
THREAT WITH THESE STORMS.
AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS
NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY
AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME
SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A
MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE
PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT
IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG
WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN
BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER
THUNDERSTORMS ARE POSSIBLE.
KMD
KMD
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER
SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY
WILL GET.
* MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW
TO MEDIUM FOR TIMING AND COVERAGE.
* LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER
CONFIDENCE LATE AFTERNOON AND EVENING.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
&&
.MARINE...
333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE
WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER
SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH
WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE
TONIGHT.
WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL
BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH
FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN ARE POSSIBLE.
BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS
EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE...
BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF
NORTHEAST IL. MRC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM
WEDNESDAY.
DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
933 PM CDT WED APR 8 2015
.UPDATE...IN SPITE OF THE FACT THAT WEBCAMS INDICATE THE FOG HAS
IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT HESITANT TO
DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD FAVOR IT TO
REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM FRONT AND
HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE COLDER AIR
MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD REDEVELOP
OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE ADVISORY IN
PLACE.
IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM
ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED
CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS
ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS
OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID-
LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS
LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS
SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM
FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED
TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A
RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL
LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE
DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT
WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL.
KJB
&&
.SHORT TERM...
322 PM CDT
THROUGH THURSDAY NIGHT...
QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER
POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING
TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE
MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING
WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE
MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY.
THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3
PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB
SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR
DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS
JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING
WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES
THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS
IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING
EASTWARD INTO THE OZARK REGION THIS AFTERNOON.
IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL
CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY
MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING.
ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS
EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT
LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND
OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED
LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND
STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND
SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR
AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO
CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE
REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR
STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO
OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR
STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY
WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED
LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH
ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE
THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN
SOUTH OF U.S. HIGHWAY 24.
AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS
OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO
CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION
IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE
FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S
THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS
POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY.
THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS
THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE
STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON
REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY
FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON
PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A
QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM
SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S
CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS
WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY
SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/.
HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS
THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN
OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO
CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY
STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT
LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON
THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE
AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL
FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW-
LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED
CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL
REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON
ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE
REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE.
STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING
WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS.
MTF
&&
.LONG TERM...
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH.
A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE
CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF
DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST
IL CLOSER TO THE VORTICITY MAXIMUM.
SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT
THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT
WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR
THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S
SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA.
SUNDAY... FORECAST CONFIDENCE HIGH.
SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN
ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY...
SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY.
LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH
PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY
SO I LEFT OUT THUNDER.
MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM.
MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO
CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS
ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO
EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS
SYSTEM AND IT WILL NEED TO BE WATCHED.
MRC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR/OCCL IFR VSBY WITH FOG TONIGHT.
* IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR
OVERNIGHT.
* SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND
ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING.
* SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA
MORE LIKELY THURS EARLY EVENING.
KMD
//DISCUSSION...UPDATED 00Z...
IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM
CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT.
ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS
CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN
AGAIN THURSDAY AFTERNOON.
WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN
AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR
CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER
MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF
THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS
HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE
TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS
CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER
DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS
ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL
SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME
AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO
TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM
FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR
SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT
THREAT WITH THESE STORMS.
AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS
NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY
AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME
SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A
MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE
PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT
IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG
WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN
BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER
THUNDERSTORMS ARE POSSIBLE.
KMD
KMD
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER
SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY
WILL GET.
* MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW
TO MEDIUM FOR TIMING AND COVERAGE.
* LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER
CONFIDENCE LATE AFTERNOON AND EVENING. S
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
&&
.MARINE...
333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE
WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER
SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH
WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE
TONIGHT.
WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL
BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH
FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN ARE POSSIBLE.
BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS
EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE...
BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF
NORTHEAST IL. MRC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM
WEDNESDAY.
DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
759 PM CDT WED APR 8 2015
.UPDATE...547 PM CDT
I ADDED A DENSE FOG ADVISORY FOR LAKE AND COOK COUNTIES IN
ILLINOIS AS DENSE FOG HAS DEVELOPED NEAR THE LAKE SHORES. IT IS
POSSIBLE THIS DENSE FOG COULD DEVELOP FARTHER INLAND THROUGH THE
EVENING. IT IS EVEN POSSIBLE THAT FOG COULD OVERSPREAD MUCH OF
NORTHERN ILLINOIS TONIGHT AS A WARM FRONT AND HIGH DEW POINT AIR
BEGINS TO SLOWLY SHIFT NORTHWARD INTO THE COLDER AIRMASS ACROSS
NORTHERN ILLINOIS. CONFIDENCE REMAINS LOW ON THE EXTENT OF INLAND
DEVELOPMENT OF THIS FOG...HOWEVER...AS SHOWERS AND THUNDERSTORM
ACTIVITY COULD DIMINISH THE EXTENT OF FOG COVERAGE OVERNIGHT.
SO...WE WILL CONTINUE TO MONITOR THIS THREAT THROUGH THE EVENING.
KJB
&&
.SHORT TERM...
322 PM CDT
THROUGH THURSDAY NIGHT...
QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER
POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING
TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE
MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING
WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE
MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY.
THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3
PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB
SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR
DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS
JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING
WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES
THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS
IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING
EASTWARD INTO THE OZARK REGION THIS AFTERNOON.
IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL
CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY
MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING.
ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS
EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT
LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND
OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED
LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND
STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND
SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR
AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO
CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE
REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR
STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO
OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR
STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY
WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED
LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH
ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE
THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN
SOUTH OF U.S. HIGHWAY 24.
AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS
OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO
CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION
IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE
FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S
THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS
POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY.
THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS
THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE
STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON
REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY
FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON
PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A
QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM
SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S
CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS
WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY
SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/.
HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS
THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN
OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO
CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY
STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT
LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON
THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE
AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL
FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW-
LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED
CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL
REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON
ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE
REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE.
STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING
WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS.
MTF
&&
.LONG TERM...
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH.
A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE
CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF
DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST
IL CLOSER TO THE VORTICITY MAXIMUM.
SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT
THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT
WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR
THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S
SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA.
SUNDAY... FORECAST CONFIDENCE HIGH.
SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN
ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY...
SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY.
LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH
PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY
SO I LEFT OUT THUNDER.
MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM.
MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO
CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS
ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO
EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS
SYSTEM AND IT WILL NEED TO BE WATCHED.
MRC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR/OCCL IFR VSBY WITH FOG TONIGHT.
* IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR
OVERNIGHT.
* SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND
ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING.
* SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA
MORE LIKELY THURS EARLY EVENING.
KMD
//DISCUSSION...UPDATED 00Z...
IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM
CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT.
ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS
CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN
AGAIN THURSDAY AFTERNOON.
WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN
AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR
CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER
MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF
THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS
HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE
TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS
CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER
DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS
ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL
SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME
AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO
TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM
FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR
SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT
THREAT WITH THESE STORMS.
AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS
NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY
AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME
SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A
MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE
PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT
IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG
WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN
BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER
THUNDERSTORMS ARE POSSIBLE.
KMD
KMD
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER
SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY
WILL GET.
* MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW
TO MEDIUM FOR TIMING AND COVERAGE.
* LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER
CONFIDENCE LATE AFTERNOON AND EVENING. S
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
&&
.MARINE...
333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE
WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER
SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH
WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE
TONIGHT.
WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL
BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH
FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN ARE POSSIBLE.
BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS
EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE...
BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF
NORTHEAST IL. MRC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM
WEDNESDAY.
DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 PM CDT TUE APR 7 2015
.UPDATE...
1129 AM CDT
HAVE UPDATED GRIDS/TEXT PRODUCTS ALREADY TO LOWER TEMPERATURES
TODAY...ESPECIALLY NEAR THE LAKE WHERE STIFF WIND OFF THE LAKE
SHOULD MAKE IT HARD FOR TEMPS TO EVEN REACH 40 THIS AFTERNOON.
WEBCAMS ALONG THE LAKE AND LAURIE CHILDREN`S HOSP HELIPORT AWOS
INDICATE THAT DENSE MARINE FOG IS MAKING IT SLIGHTLY ONSHORE.
CERTAINLY POSSIBLE THAT FOG COULD GROW DENSER ALONG THE LAKE LATER
TODAY OR TONIGHT AND POTENTIALLY REQUIRE A HEADLINE. HAVE BACKED
OFF ON POPS SIGNIFICANTLY TODAY ONE MCV PASSES WELL TO OUR SOUTH
AND WE ARE LEFT WAITING FOR THE NEXT UPSTREAM IMPULSE TO KICK OFF
CONVECTION WHICH LOOKS TO BE TONIGHT...OR POSSIBLE VERY LATE THIS
AFTERNOON WESTERN CWA.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH THURSDAY NIGHT...
THE MAIN FOCUS IN THE NEAR TERM REMAINS ON IDENTIFYING THE BEST
TIMING FOR ROUNDS OF SHOWERS AND THUNDERSTORMS AS INDIVIDUAL SHORT
WAVES PROPAGATE ALONG WEST-EAST BAROCLINC ZONE ASSOCIATED WITH A
NEARLY STATIONARY SURFACE FRONT ACROSS CENTRAL ILLINOIS AND
INDIANA. IN ADDITION...SUBSTANTIAL CONCERN IS BREWING FOR THE
POTENTIAL OF ORGANIZED SEVERE WEATHER ON THURSDAY...WITH ENERGETIC
UPPER TROUGH AND DEEP SURFACE LOW EXPECTED TO MOVE INTO THE AREA.
THIS MORNING...THE NEARLY STATIONARY SURFACE FRONT HAS DRIFTED A
BIT TO THE SOUTH IN THE WAKE OF A MINOR-AMPLITUDE MID-LEVEL SHORT
WAVE AND WEAK SURFACE WAVE ALONG THE FRONT WHICH WAS MOVING INTO
INDIANA. A CLUSTER OF SHOWERS AND A FEW THUNDERSTORMS HAVE ALSO
MOVED OFF TO THE EAST EARLY THIS MORNING WITH THE AXIS OF BETTER
LOW LEVEL MOISTURE TRANSPORT AND THE VEERING OF A MODEST 30 KT LOW
LEVEL JET ASSOCIATED WITH THE PASSING SHORT WAVE. WHILE SOME LIGHT
DRIZZLE OR SPOTTY LIGHT SHOWERS WILL REMAIN POSSIBLE WITH WEAK BUT
PERSISTENT WARM/MOIST ADVECTION WITHING THE FRONTAL ZONE...IT
APPEARS THERE WILL BE A LULL IN MORE ORGANIZED PRECIPITATION UNTIL
ANOTHER SHORT WAVE ARRIVES. LOOKING UPSTREAM IN WATER VAPOR
IMAGERY THIS MORNING ONE SUCH WAVE WAS EVIDENT OVER EASTERN
KANSAS...WITH ELEVATED CONVECTION NOTED JUST EAST OF KANSAS CITY.
YET ANOTHER IDENTIFIABLE WAVE WAS CROSSING THE CENTRAL ROCKIES.
PRECIP POTENTIAL THUS LOOKS TO INCREASE AGAIN FROM THE
WEST/SOUTHWEST THIS AFTERNOON INTO TONIGHT AS THESE WAVES
APPROACH. MODELS HAVE CONSISTENTLY DEPICTED THE DEEPER COLORADO
SHORT WAVE TRACKING TOWARD THE REGION TONIGHT INTO EARLY
WEDNESDAY...ENHANCING WARM/MOIST ADVECTION INTO THE FORECAST AREA
TONIGHT. STRONGER MOISTURE TRANSPORT LOOKS TO FOCUS INTO THE AREA
BY EARLY EVENING WITH GOOD SUPPORT FOR SHOWERS AND
THUNDERSTORMS...NOTABLY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF
7.5 C/KM AND A POSITION BENEATH RIGHT ENTRANCE DIVERGENCE REGION
OF UPPER JET STREAK NORTHEAST OF THE LAKES. HAVE CARRIED LIKELY
POPS AND MENTION OF THUNDER CWA-WIDE TONIGHT...BEFORE PRECIP
COVERAGE IS EXPECTED TO AGAIN DECREASE AFTER SUNRISE WEDNESDAY
MORNING AS THE WAVE TRACKS TO THE EAST AND LOW LEVEL JET
VEERS/WEAKENS.
ATTENTION THEN TURNS TO THE UPPER TROUGH WHICH HAS BEEN JUST OFF
OF THE WEST COAST...AND IS PROGGED TO MOVE INLAND ACROSS THE
INTERMOUNTAIN WEST AND THE ROCKIES THROUGH WEDNESDAY. GUIDANCE HAS
REMAINED SIMILAR IN WRAPPING JET ENERGY AROUND THE BASE OF THIS
DEEP UPPER LOW AND EJECTING SHORT WAVE ACROSS THE MID-MISSISSIPPI
VALLEY LATE WEDNESDAY AND WEDNESDAY NIGHT...WITH THE MAIN UPPER
TROUGH THEN LIFTING NORTHEAST AND BECOMING A SOMEWHAT
COMPACT/NEGATIVE TILT SYSTEM AS IT APPROACHES OUR AREA ON
THURSDAY. THIS SETS THE STAGE FOR STRONG THERMAL/MOISTURE
ADVECTION DEVELOPING ACROSS THE MIDWEST LATE WEDNESDAY AND
WEDNESDAY NIGHT...AND THE SURFACE FRONT LIFTING NORTH AS A WARM
FRONT ACROSS THE AREA THROUGH THURSDAY AS THE DEEP SURFACE LOW
WITH THE MAIN UPPER TROUGH MOVES INTO THE UPPER MIDWEST. THIS
LOOKS TO PRODUCE A FAIRLY WIDESPREAD AREA OF CONVECTION WHICH WILL
IMPACT THE CWA WEDNESDAY NIGHT INTO EARLY THURSDAY.
AS THE WARM FRONT LIFTS NORTH INTO/ACROSS THE CWA THURSDAY
AFTERNOON...THE MOISTURE RICH WARM SECTOR HAS THE POTENTIAL TO
BECOME STRONGLY UNSTABLE. FORECAST SOUNDINGS FROM THE GFS AND NAM
BOTH DEPICT MLCAPES IN THE 1500-2500 J/KG RANGE IN THE WARM SECTOR
ACROSS OUR AREA BY THURSDAY AFTERNOON...COINCIDENT WITH 40-50 KT
0-6 KM BULK SHEAR AND STRONG ASCENT AHEAD OF APPROACHING DEEP
UPPER TROUGH. MANY MODEL RUNS TAKE THE SYSTEM SURFACE LOW ACROSS
NORTHEAST IA/SOUTHWEST WI BY THURSDAY EVENING..WITH A COLD FRONT
PUSHING ACROSS THE MISSISSIPPI RIVER AND ACROSS NORTHERN IL/IN
THURSDAY EVENING. THIS LOOKS TO PRESENT A SUBSTANTIAL SEVERE
WEATHER THREAT ESPECIALLY IN THE THURSDAY AFTERNOON/EARLY EVENING
PERIOD...WITH MORE THAN SUFFICIENT SHEAR/INSTABILITY FOR SUPERCELL
STORMS WHICH MAY THEN EVOLVE INTO A SEVERE LINEAR MCS. DETAILS OF
MORNING CONVECTIVE DEBRIS AND CLOUDINESS AND POSITION OF THE
EFFECTIVE SURFACE WARM FRONTAL BOUNDARY WILL ALL ULTIMATELY AFFECT
HOW AFTERNOON STORMS EVOLVE. SPC HAS MAINTAINED A 30 PERCENT
ENHANCED SEVERE RISK AREA OVER OUR ENTIRE CWA FOR THIS PERIOD.
SEVERE THREAT AS WELL AS GENERAL SHOWER/THUNDERSTORM THREAT SHOULD
DIMINISH QUICKLY BEHIND THE COLD FRONT THURSDAY NIGHT.
TEMPS WILL CONTINUE TO SHOW BIG NORTH-SOUTH RANGE WITH EAST-
NORTHEAST FLOW OFF COOL LAKE KEEPING NORTHERN COUNTIES AND
ESPECIALLY LAKE SHORE AREAS CHILLY THROUGH WEDNESDAY NIGHT.
FARTHER SOUTH...CLOSER TO THE SURFACE FRONT TEMPS WILL LIKELY BE
ABLE TO REACH THE MID-UPPER 60S ESPECIALLY IF A LITTLE SUN BREAKS
THROUGH. ON THURSDAY...70S ARE LIKELY ALONG/SOUTH OF THE NORTHWARD
ADVANCING WARM FRONT.
RATZER
&&
.LONG TERM...
422 AM CDT
FRIDAY THROUGH MONDAY...
WITH THE COLD FRONT EAST OF THE FORECAST AREA BY EARLY
FRIDAY...AND THE UPPER TROUGH AND SURFACE LOW PASSING NORTH OF THE
IL/WI BORDER FOR THE MOST PART...DRIER AIR MOVES IN FOR FRIDAY AND
SATURDAY AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. MEDIUM
RANGE GUIDANCE SHOWING SOME DIFFERENCE IN DETAILS WITH PATTERN
OVER THE WEEKEND AND INTO EARLY NEXT WEEK BUT GENERALLY DEVELOP
UPPER RIDGE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY...DOWNSTREAM
OF AN AMPLIFIED UPPER TROUGH OVER THE WESTERN CONUS. THIS SETS UP
A RETURN OF SOUTH FLOW AND WARM/MOIST ADVECTION LATER SUNDAY AND
MONDAY...WITH THE POTENTIAL FOR SHOWERS AND STORMS TO RETURN AS
THE UPPER TROUGH APPROACHES. AFTER A SLIGHT COOL-DOWN FRIDAY INTO
SATURDAY (THOUGH NEAR NORMAL AND WARMER THAN OUR CURRENT CHILLY
TEMPS)...WARMER WEATHER RETURNS SUNDAY-MONDAY WITH HIGHS IN THE
MID-UPPER 60S.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* PERSISTENT IFR CIGS/VSBYS THIS AFTERNOON WITH LIFR POSSIBLE.
* NORTHEAST WINDS GUSTING AT TIMES OVER 20 KTS.
* TSRA CHANCES OVERNIGHT.
* CONTINUED IFR TOMORROW.
LENNING
//DISCUSSION...UPDATED 18Z...
CONDITIONS CONTINUE TO DETERIORATE GRADUALLY THIS AFTERNOON
RAISING THE QUESTION OF HOW LOW CIGS AND VSBYS WILL DROP. CIGS
RANGED FROM 300-600FT IN THE CHI METRO AREA AS OF THE 18Z TAF
TIME WITH THE LOWEST VALUES JUST SOUTH OF THE MDW TERMINAL.
MEANWHILE TO THE NORTH TOWARD MKX CONDITIONS WERE STAYING IN THE
MVFR TO VFR RANGE. BETTER SFC AND LOW LEVEL MOISTURE OVER NE IL
WOULD APPEAR TO BE SUPPORTING THE LOWER CONDITIONS IN THIS AREA.
MODELS SUGGEST PERSISTENCE OR EVEN EXPANSION OF THIS MOISTURE
THROUGH THE DAY INTO THE EVENING HOURS. A BREAK MAY COME WITH THE
DEVELOPMENT OF SHOWERS AND POSSIBLE THUNDERSTORMS TOWARD LATE
EVENING THOUGH THIS WOULD BE AFTER THE PEAK TRAFFIC PERIOD.
TOMORROW SHOWS LITTLE CHANGE AFTER PRECIPITATION MOVES OUT DURING
THE PREDAWN HOURS. IN FACT...WITH THE PERSISTENT AIRMASS AND
INCREASED SURFACE MOISTURE INTRODUCED BY OVERNIGHT
RAINFALL...THE POTENTIAL EXISTS FOR LOWER CONDITIONS
TOMORROW...AT LEAST THROUGH THE MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW TO MEDIUM CONFIDENCE IN CIG/VSBY TRENDS...STILL UNSURE OF
WHETHER THEY GO TO LIFR THIS AFTERNOON AND EVENING.
* MEDIUM TO HIGH CONFIDENCE IN WINDS REMAINING MAINLY NORTHEAST.
* MEDIUM CONFIDENCE IN SHRA AND TSRA TIMING TONIGHT.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...SHRA/TSRA. IFR. EAST/SOUTHEAST WINDS.
* THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST
WINDS.
* FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. SOUTHEAST WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
&&
.MARINE...
348 AM...A FRONTAL BOUNDARY WILL REMAIN GENERALLY STATIONARY
THROUGH WEDNESDAY JUST SOUTH OF LAKE MICHIGAN...AS STRONG HIGH
PRESSURE MOVES ACROSS ONTARIO TODAY AND INTO QUEBEC TONIGHT. THIS
WILL TIGHTEN THE GRADIENT LATER TODAY INTO TONIGHT WITH A PERIOD
OF 30KTS EXPECTED. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS WEDNESDAY NIGHT AND MOVE NORTHEAST TOWARD NORTHERN LAKE
MICHIGAN BY FRIDAY MORNING. THE EXACT TRACK OF THIS LOW REMAINS
SOMEWHAT UNCERTAIN...BUT THESE TRENDS WOULD SUPPORT THE FRONTAL
BOUNDARY MOVING NORTH AS A WARM FRONT WEDNESDAY NIGHT INTO
THURSDAY. THUS THERE IT THE POTENTIAL FOR LARGE CHANGES TO WIND
DIRECTIONS OVER PARTS OF THE LAKE FROM WEDNESDAY NIGHT INTO
THURSDAY NIGHT. EVENTUALLY WINDS WILL SHIFT WESTERLY LATE THURSDAY
NIGHT INTO FRIDAY MORNING...THEN BEGIN TO DIMINISH FRIDAY NIGHT AS
HIGH PRESSURE MOVES ACROSS THE LAKE ON SATURDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1255 PM CDT Tue Apr 7 2015
.UPDATE...
ISSUED AT 1040 AM CDT TUE APR 7 2015
Will update the forecast around 11 am when dense fog advisory over
central IL expires. Some patchy fog may linger into midday over areas
north of I-70 but most of the dense fog over central IL should
lift late this morning. A frontal boundary has sagged southward
into central IL near I-72 late this morning and HRRR models keeps
this boundary near I-72 into early evening. 1007 mb surface low
pressure over ne KS will track into nw MO early this evening and
tug front slowly back north during tonight. Have cooled highs
north of this boundary with upper 50s and lower 60s for highs from
Galesburg, Peoria and Bloomington north where low clouds persist.
Showers south of I-72 with thunderstorms from Litchfied sw and
some strong to severe with heavy rains from St Louis south. Severe
storms should stay along and south of I-64 today though a few
thunderstorms could affect areas from I-72 south this afternoon
along and south of the boundary. Milder highs in low to mid 70s in
sw CWA from Springfield to Terre Haute sw where some peaks of
sunshine to appear during the afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 335 AM CDT TUE APR 7 2015
A few showers and isolated thunderstorms will continue to move
across southeast Illinois early this morning. HiRes short term
models develop another area of showers and isolated thunderstorms
over northern MO and then bring them into central IL late morning
and into the afternoon. The warm front has setup and is sitting
right through central IL, north of a Quincy to Springfield to
Mattoon line, which puts half of the cwa south of the front, and
the I-74 area, including Lincoln, north of the front. So, area of
convection that does develop should follow along and just north of
the front when it arrives later this morning. So, have likely pops
in the southeast for this morning, and then slightly higher pops
in the afternoon for the west central. With front right across CWA
high temp spread with be around 15 degrees across the CWA today.
Cloud cover will also be persistent today, with some light fog
this morning. With pcpn being mainly scattered, qpf values will
not be that significant.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 335 AM CDT TUE APR 7 2015
The warm front should become a little more active this evening and
shift north, as the first in a series of low pressure areas moves
along the frontal zone. So, higher pcpn chances will be in the
north for tonight with chance pops remaining for the rest of the
area, which will be in the warm sector. Lowest pops will be in the
south. As this first low moves east, it will drag the cold front
south through the cwa, so pops for Wed morning will be higher to
the south and only a slight chance in the north. However, the next
wave/low press area will lift out Wed afternoon and return chance
pops for the whole area. This one will lift northeast through the
area and bring much higher chances of pcpn to the CWA for late Wed
afternoon through Wed night. Per SPC day 2 outlook, there is a
slight risk of severe weather nosing into west central IL for late
Wed afternoon and into Wed night. Highest pops will be west of
I-55. Probably will be a little break Wed night after midnight,
but will not put that in just yet.
Then on Thursday, the main sfc system will lift out of the plains
with the associated mid level wave. Though there may be pcpn
ongoing Thur morning in the east, by afternoon most of the area
should be pcpn free and the atmosphere should be able to recover
before the next round of pcpn. Forecasted CAPE values will be 2000
to 2500 across a good portion of IL in the warm sector ahead of
the front. A strong upper level jet will also be pushing into the
area at the same time, so wind dynamics and shear will be
sufficient that storms will likely rotate. There is still some
uncertainty as to how this will play out Thur given the Wed night
and early morning convection, but if airmass recovers, it looks
like a line of convection will develop just west of the state late
afternoon and then move east across the state Thur evening. All
forms of severe weather look to be possible late afternoon through
the evening hours. Something to consider is that storms may be
moving at about 40-45 mph. By midnight, most of the storms should
be east of the state, but will hang on to some chance pops.
Past this system, dry conditions are expected for Fri through Sat
night. Then another system moves toward the area for Sunday
through Monday with more showers and storms.
Expecting very warm temps for Thur, but then temps will cool some
Fri and Sat, but warm back a tad for Sun and Mon.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1255 PM CDT TUE APR 7 2015
Dense fog lingering at BMI...CMI and DEC airports will gradually
lift into mid afternoon with MVFR to possibly vfr vsbys. Vsbys at
PIA and SPI have lifted to 1-2 miles and to lift to MVFR and VFR
next few hours. Very low ceilings of 100-300 ft to lift to
700-1500 feet during mid/late afternoon across central IL. I-72 is
on northern edge of showers and isolated thunderstorms and will
carry vcsh at SPI and DEC into mid afternoon with VCTS at CMI.
Scattered showers/thunderstorms possible by overnight into mid
morning Wed as frontal boundary just south of I-72 lifts slowly
back north as 1007 mb surface low pressure over ne KS moves into
central IL by 12Z/Wed. ENE winds around 10 kts to veer SSE during
tonight and SW Wed morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT TUE APR 7 2015
.SHORT TERM...
408 AM CDT
TODAY THROUGH THURSDAY NIGHT...
THE MAIN FOCUS IN THE NEAR TERM REMAINS ON IDENTIFYING THE BEST
TIMING FOR ROUNDS OF SHOWERS AND THUNDERSTORMS AS INDIVIDUAL SHORT
WAVES PROPAGATE ALONG WEST-EAST BAROCLINC ZONE ASSOCIATED WITH A
NEARLY STATIONARY SURFACE FRONT ACROSS CENTRAL ILLINOIS AND
INDIANA. IN ADDITION...SUBSTANTIAL CONCERN IS BREWING FOR THE
POTENTIAL OF ORGANIZED SEVERE WEATHER ON THURSDAY...WITH ENERGETIC
UPPER TROUGH AND DEEP SURFACE LOW EXPECTED TO MOVE INTO THE AREA.
THIS MORNING...THE NEARLY STATIONARY SURFACE FRONT HAS DRIFTED A
BIT TO THE SOUTH IN THE WAKE OF A MINOR-AMPLITUDE MID-LEVEL SHORT
WAVE AND WEAK SURFACE WAVE ALONG THE FRONT WHICH WAS MOVING INTO
INDIANA. A CLUSTER OF SHOWERS AND A FEW THUNDERSTORMS HAVE ALSO
MOVED OFF TO THE EAST EARLY THIS MORNING WITH THE AXIS OF BETTER
LOW LEVEL MOISTURE TRANSPORT AND THE VEERING OF A MODEST 30 KT LOW
LEVEL JET ASSOCIATED WITH THE PASSING SHORT WAVE. WHILE SOME LIGHT
DRIZZLE OR SPOTTY LIGHT SHOWERS WILL REMAIN POSSIBLE WITH WEAK BUT
PERSISTENT WARM/MOIST ADVECTION WITHING THE FRONTAL ZONE...IT
APPEARS THERE WILL BE A LULL IN MORE ORGANIZED PRECIPITATION UNTIL
ANOTHER SHORT WAVE ARRIVES. LOOKING UPSTREAM IN WATER VAPOR
IMAGERY THIS MORNING ONE SUCH WAVE WAS EVIDENT OVER EASTERN
KANSAS...WITH ELEVATED CONVECTION NOTED JUST EAST OF KANSAS CITY.
YET ANOTHER IDENTIFIABLE WAVE WAS CROSSING THE CENTRAL ROCKIES.
PRECIP POTENTIAL THUS LOOKS TO INCREASE AGAIN FROM THE
WEST/SOUTHWEST THIS AFTERNOON INTO TONIGHT AS THESE WAVES
APPROACH. MODELS HAVE CONSISTENTLY DEPICTED THE DEEPER COLORADO
SHORT WAVE TRACKING TOWARD THE REGION TONIGHT INTO EARLY
WEDNESDAY...ENHANCING WARM/MOIST ADVECTION INTO THE FORECAST AREA
TONIGHT. STRONGER MOISTURE TRANSPORT LOOKS TO FOCUS INTO THE AREA
BY EARLY EVENING WITH GOOD SUPPORT FOR SHOWERS AND
THUNDERSTORMS...NOTABLY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF
7.5 C/KM AND A POSITION BENEATH RIGHT ENTRANCE DIVERGENCE REGION
OF UPPER JET STREAK NORTHEAST OF THE LAKES. HAVE CARRIED LIKELY
POPS AND MENTION OF THUNDER CWA-WIDE TONIGHT...BEFORE PRECIP
COVERAGE IS EXPECTED TO AGAIN DECREASE AFTER SUNRISE WEDNESDAY
MORNING AS THE WAVE TRACKS TO THE EAST AND LOW LEVEL JET
VEERS/WEAKENS.
ATTENTION THEN TURNS TO THE UPPER TROUGH WHICH HAS BEEN JUST OFF
OF THE WEST COAST...AND IS PROGGED TO MOVE INLAND ACROSS THE
INTERMOUNTAIN WEST AND THE ROCKIES THROUGH WEDNESDAY. GUIDANCE HAS
REMAINED SIMILAR IN WRAPPING JET ENERGY AROUND THE BASE OF THIS
DEEP UPPER LOW AND EJECTING SHORT WAVE ACROSS THE MID-MISSISSIPPI
VALLEY LATE WEDNESDAY AND WEDNESDAY NIGHT...WITH THE MAIN UPPER
TROUGH THEN LIFTING NORTHEAST AND BECOMING A SOMEWHAT
COMPACT/NEGATIVE TILT SYSTEM AS IT APPROACHES OUR AREA ON
THURSDAY. THIS SETS THE STAGE FOR STRONG THERMAL/MOISTURE
ADVECTION DEVELOPING ACROSS THE MIDWEST LATE WEDNESDAY AND
WEDNESDAY NIGHT...AND THE SURFACE FRONT LIFTING NORTH AS A WARM
FRONT ACROSS THE AREA THROUGH THURSDAY AS THE DEEP SURFACE LOW
WITH THE MAIN UPPER TROUGH MOVES INTO THE UPPER MIDWEST. THIS
LOOKS TO PRODUCE A FAIRLY WIDESPREAD AREA OF CONVECTION WHICH WILL
IMPACT THE CWA WEDNESDAY NIGHT INTO EARLY THURSDAY.
AS THE WARM FRONT LIFTS NORTH INTO/ACROSS THE CWA THURSDAY
AFTERNOON...THE MOISTURE RICH WARM SECTOR HAS THE POTENTIAL TO
BECOME STRONGLY UNSTABLE. FORECAST SOUNDINGS FROM THE GFS AND NAM
BOTH DEPICT MLCAPES IN THE 1500-2500 J/KG RANGE IN THE WARM SECTOR
ACROSS OUR AREA BY THURSDAY AFTERNOON...COINCIDENT WITH 40-50 KT
0-6 KM BULK SHEAR AND STRONG ASCENT AHEAD OF APPROACHING DEEP
UPPER TROUGH. MANY MODEL RUNS TAKE THE SYSTEM SURFACE LOW ACROSS
NORTHEAST IA/SOUTHWEST WI BY THURSDAY EVENING..WITH A COLD FRONT
PUSHING ACROSS THE MISSISSIPPI RIVER AND ACROSS NORTHERN IL/IN
THURSDAY EVENING. THIS LOOKS TO PRESENT A SUBSTANTIAL SEVERE
WEATHER THREAT ESPECIALLY IN THE THURSDAY AFTERNOON/EARLY EVENING
PERIOD...WITH MORE THAN SUFFICIENT SHEAR/INSTABILITY FOR SUPERCELL
STORMS WHICH MAY THEN EVOLVE INTO A SEVERE LINEAR MCS. DETAILS OF
MORNING CONVECTIVE DEBRIS AND CLOUDINESS AND POSITION OF THE
EFFECTIVE SURFACE WARM FRONTAL BOUNDARY WILL ALL ULTIMATELY AFFECT
HOW AFTERNOON STORMS EVOLVE. SPC HAS MAINTAINED A 30 PERCENT
ENHANCED SEVERE RISK AREA OVER OUR ENTIRE CWA FOR THIS PERIOD.
SEVERE THREAT AS WELL AS GENERAL SHOWER/THUNDERSTORM THREAT SHOULD
DIMINISH QUICKLY BEHIND THE COLD FRONT THURSDAY NIGHT.
TEMPS WILL CONTINUE TO SHOW BIG NORTH-SOUTH RANGE WITH EAST-
NORTHEAST FLOW OFF COOL LAKE KEEPING NORTHERN COUNTIES AND
ESPECIALLY LAKE SHORE AREAS CHILLY THROUGH WEDNESDAY NIGHT.
FARTHER SOUTH...CLOSER TO THE SURFACE FRONT TEMPS WILL LIKELY BE
ABLE TO REACH THE MID-UPPER 60S ESPECIALLY IF A LITTLE SUN BREAKS
THROUGH. ON THURSDAY...70S ARE LIKELY ALONG/SOUTH OF THE NORTHWARD
ADVANCING WARM FRONT.
RATZER
&&
.LONG TERM...
422 AM CDT
FRIDAY THROUGH MONDAY...
WITH THE COLD FRONT EAST OF THE FORECAST AREA BY EARLY
FRIDAY...AND THE UPPER TROUGH AND SURFACE LOW PASSING NORTH OF THE
IL/WI BORDER FOR THE MOST PART...DRIER AIR MOVES IN FOR FRIDAY AND
SATURDAY AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. MEDIUM
RANGE GUIDANCE SHOWING SOME DIFFERENCE IN DETAILS WITH PATTERN
OVER THE WEEKEND AND INTO EARLY NEXT WEEK BUT GENERALLY DEVELOP
UPPER RIDGE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY...DOWNSTREAM
OF AN AMPLIFIED UPPER TROUGH OVER THE WESTERN CONUS. THIS SETS UP
A RETURN OF SOUTH FLOW AND WARM/MOIST ADVECTION LATER SUNDAY AND
MONDAY...WITH THE POTENTIAL FOR SHOWERS AND STORMS TO RETURN AS
THE UPPER TROUGH APPROACHES. AFTER A SLIGHT COOL-DOWN FRIDAY INTO
SATURDAY (THOUGH NEAR NORMAL AND WARMER THAN OUR CURRENT CHILLY
TEMPS)...WARMER WEATHER RETURNS SUNDAY-MONDAY WITH HIGHS IN THE
MID-UPPER 60S.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* IFR TO MVFR CEILINGS AND VSBYS TODAY...LIFR POSSIBLE TONIGHT.
* NORTHEAST WINDS.
* THUNDERSTORM CHANCES TONIGHT.
LENNING
//DISCUSSION...UPDATED 12Z...
LIGHT SHOWERS/DRIZZLE HAVE REDEVELOPED AND BECOME QUITE WIDESPREAD
THIS MORNING. SHORT TERM/HI RES GUIDANCE SUGGESTS THIS WILL SLOWLY
DISSIPATE DURING THE MID/LATE MORNING SO HAVE ADDED PRECIP IN FOR
A FEW HOURS TRENDING BACK TO VCSH DUE TO LOWER UNCERTAINTY. THIS
AFTERNOON IS STILL LOOKING MAINLY DRY AS CONVECTION CURRENTLY
ACROSS NORTHEAST MO SHIFTS MORE EAST AND ALSO APPEARS TO DISSIPATE
SOME LATER THIS MORNING. FOCUS THEN SHIFTS BACK TO THE WEST/
NORTHWEST LATE THIS AFTERNOON INTO THIS EVENING. ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER NORTHEAST
IA AND MOVE EAST/SOUTHEAST LATER THIS EVENING AND OVERNIGHT.
FAIRLY CONFIDENT CONVECTION WILL DEVELOP BUT LOWER CONFIDENCE
REGARDING MOVEMENT/LOCATION/TIMING. OPTED TO INCLUDE A TEMPO FOR
THUNDER LATE THIS EVENING/OVERNIGHT BUT REFINEMENT CAN BE EXPECTED
WITH LATER FORECASTS.
CIGS HAVE BEEN SLOW TO LOWER ACROSS ORD/MDW/DPA WITH MDW JUST NOW
INTO IFR. SLIGHTLY DRIER NORTHEAST FLOW COMBINED WITH A LACK OF
SIGNIFICANT PRECIP MAY ALLOW CIGS TO STAY ABOVE IFR TODAY BUT HAVE
MAINTAINED IFR CIGS IN THE FORECAST WITH LOW CONFIDENCE. CIGS WILL
LIKELY LOWER EITHER TO IFR OR POTENTIALLY LIFR LATER THIS EVENING
OR OVERNIGHT...ESPECIALLY IF PRECIP DOES BECOME WIDESPREAD LATER
THIS EVENING AND OVERNIGHT.
NORTHEAST WINDS WILL REMAIN IN THE 12-16KT RANGE FOR MUCH OF THE
PERIOD WITH GUSTS INTO THE LOWER/MID 20KT RANGE AT TIMES. WINDS
MAY TURN A BIT MORE EASTERLY TONIGHT WITH SPEEDS/GUSTS DIMINISHING
SOME INTO WEDNESDAY MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN CEILING AND VSBY TRENDS.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...SHRA/TSRA. IFR. EAST/SOUTHEAST WINDS.
* THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST
WINDS.
* FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. SOUTHEAST WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
&&
.MARINE...
348 AM...A FRONTAL BOUNDARY WILL REMAIN GENERALLY STATIONARY
THROUGH WEDNESDAY JUST SOUTH OF LAKE MICHIGAN...AS STRONG HIGH
PRESSURE MOVES ACROSS ONTARIO TODAY AND INTO QUEBEC TONIGHT. THIS
WILL TIGHTEN THE GRADIENT LATER TODAY INTO TONIGHT WITH A PERIOD
OF 30KTS EXPECTED. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS WEDNESDAY NIGHT AND MOVE NORTHEAST TOWARD NORTHERN LAKE
MICHIGAN BY FRIDAY MORNING. THE EXACT TRACK OF THIS LOW REMAINS
SOMEWHAT UNCERTAIN...BUT THESE TRENDS WOULD SUPPORT THE FRONTAL
BOUNDARY MOVING NORTH AS A WARM FRONT WEDNESDAY NIGHT INTO
THURSDAY. THUS THERE IT THE POTENTIAL FOR LARGE CHANGES TO WIND
DIRECTIONS OVER PARTS OF THE LAKE FROM WEDNESDAY NIGHT INTO
THURSDAY NIGHT. EVENTUALLY WINDS WILL SHIFT WESTERLY LATE THURSDAY
NIGHT INTO FRIDAY MORNING...THEN BEGIN TO DIMINISH FRIDAY NIGHT AS
HIGH PRESSURE MOVES ACROSS THE LAKE ON SATURDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1043 AM CDT Tue Apr 7 2015
.UPDATE...
ISSUED AT 1040 AM CDT TUE APR 7 2015
Will update the forecast around 11 am when dense fog advisory over
central IL expires. Some patchy fog may linger into midday over areas
north of I-70 but most of the dense fog over central IL should
lift late this morning. A frontal boundary has sagged southward
into central IL near I-72 late this morning and HRRR models keeps
this boundary near I-72 into early evening. 1007 mb surface low
pressure over ne KS will track into nw MO early this evening and
tug front slowly back north during tonight. Have cooled highs
north of this boundary with upper 50s and lower 60s for highs from
Galesburg, Peoria and Bloomington north where low clouds persist.
Showers south of I-72 with thunderstorms from Litchfied sw and
some strong to severe with heavy rains from St Louis south. Severe
storms should stay along and south of I-64 today though a few
thunderstorms could affect areas from I-72 south this afternoon
along and south of the boundary. Milder highs in low to mid 70s in
sw CWA from Springfield to Terre Haute sw where some peaks of
sunshine to appear during the afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 335 AM CDT TUE APR 7 2015
A few showers and isolated thunderstorms will continue to move
across southeast Illinois early this morning. HiRes short term
models develop another area of showers and isolated thunderstorms
over northern MO and then bring them into central IL late morning
and into the afternoon. The warm front has setup and is sitting
right through central IL, north of a Quincy to Springfield to
Mattoon line, which puts half of the cwa south of the front, and
the I-74 area, including Lincoln, north of the front. So, area of
convection that does develop should follow along and just north of
the front when it arrives later this morning. So, have likely pops
in the southeast for this morning, and then slightly higher pops
in the afternoon for the west central. With front right across CWA
high temp spread with be around 15 degrees across the CWA today.
Cloud cover will also be persistent today, with some light fog
this morning. With pcpn being mainly scattered, qpf values will
not be that significant.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 335 AM CDT TUE APR 7 2015
The warm front should become a little more active this evening and
shift north, as the first in a series of low pressure areas moves
along the frontal zone. So, higher pcpn chances will be in the
north for tonight with chance pops remaining for the rest of the
area, which will be in the warm sector. Lowest pops will be in the
south. As this first low moves east, it will drag the cold front
south through the cwa, so pops for Wed morning will be higher to
the south and only a slight chance in the north. However, the next
wave/low press area will lift out Wed afternoon and return chance
pops for the whole area. This one will lift northeast through the
area and bring much higher chances of pcpn to the CWA for late Wed
afternoon through Wed night. Per SPC day 2 outlook, there is a
slight risk of severe weather nosing into west central IL for late
Wed afternoon and into Wed night. Highest pops will be west of
I-55. Probably will be a little break Wed night after midnight,
but will not put that in just yet.
Then on Thursday, the main sfc system will lift out of the plains
with the associated mid level wave. Though there may be pcpn
ongoing Thur morning in the east, by afternoon most of the area
should be pcpn free and the atmosphere should be able to recover
before the next round of pcpn. Forecasted CAPE values will be 2000
to 2500 across a good portion of IL in the warm sector ahead of
the front. A strong upper level jet will also be pushing into the
area at the same time, so wind dynamics and shear will be
sufficient that storms will likely rotate. There is still some
uncertainty as to how this will play out Thur given the Wed night
and early morning convection, but if airmass recovers, it looks
like a line of convection will develop just west of the state late
afternoon and then move east across the state Thur evening. All
forms of severe weather look to be possible late afternoon through
the evening hours. Something to consider is that storms may be
moving at about 40-45 mph. By midnight, most of the storms should
be east of the state, but will hang on to some chance pops.
Past this system, dry conditions are expected for Fri through Sat
night. Then another system moves toward the area for Sunday
through Monday with more showers and storms.
Expecting very warm temps for Thur, but then temps will cool some
Fri and Sat, but warm back a tad for Sun and Mon.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 615 AM CDT TUE APR 7 2015
LIFR to VLIFR conditions in fog and low stratus will be the main
forecast concern early on this morning, with a gradual improvement
to MVFR cigs/vsbys by or shortly aftr 15z this morning. A stalled
frontal boundary over central Illinois will not move much today
with areas just to the south possibly seeing cigs improve to low
VFR for a time this afternoon before all areas go back to IFR
conditions again tonight. Timing and coverage of showers and
TSRA rather complicated for today so VCSH or VCTS will be included
in areas and times where we see the better threat. Surface winds
will be east to northeast at BMI and PIA with speeds of 10 to 15
kts today, with surface winds more southeast in our southern TAF
sites which were south of the stalled frontal boundary. Winds
in those locations will also average from 10 to 15 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 11 AM CDT this morning FOR ILZ027>031-
036>038-040>057-061.
&&
$$
UPDATE...07
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
705 PM EDT WED APR 8 2015
.SYNOPSIS...
ISSUED AT 1003 AM EDT WED APR 8 2015
SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE
OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND
OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT.
SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH
SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD
FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER
ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM
THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S
SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE
50S.
&&
.SHORT TERM...(THIS EVENING AND TONIGHT)
ISSUED AT 400 PM EDT WED APR 8 2015
BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN
PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE
RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED
THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR
AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST
SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT
HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING
INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT
IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR
SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE
OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF
KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER
INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED
AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC
ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE
THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS
REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN
ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS
ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE
WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER
2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM.
BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED
LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST
ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER
ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT
IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING
CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO
PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY
LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED
CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES
GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE
PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT
OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL
DEPICTIONS OF WEAK CVA FORCING.
OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY
RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW
VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO
TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE
CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND
BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE
VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE
ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST
COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF
RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES
EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH
HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR
SOUTHEAST COUNTIES.
&&
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EDT WED APR 8 2015
PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY
NIGHT.
ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY
SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER
IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER
THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE
LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON.
AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER
THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO
SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES
THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE
ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY.
AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT
INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER.
MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES
EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING
FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON.
0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT
PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE
UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE
OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING
HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE
STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH
THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE
LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE
RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY
RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY
RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY.
THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT
OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE
FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE
STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY
EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE
00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR
SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR
A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING
WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1
KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE
BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS
INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS
ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING
CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING.
TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN
EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE
OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE.
AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER
AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL
MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS
TO BUILD INTO THE AREA.
A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN
ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION
CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER
MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY
FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING
THE CWA FRIDAY INTO FRI NIGHT.
ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY
NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM
NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO
HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND
ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME.
AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS
AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE
OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE
THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME
FRAME...MAINLY IN THE 60S AND LOW 70S.
&&
.UPDATE/AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 703 PM EDT WED APR 8 2015
SIMILAR MESOSCALE DVLPMNTS COMPARED TO YDA AT THIS TIME ALTHOUGH
CONVN IS STRUNG OUT A BIT FARTHER NORTH ALG OLD COMPOSITE
OUTFLW/STNRY FNTL BNDRY THROUGH SRN IL/IN. UPSTREAM SVR CONVN OVR WRN
MO XPCD TO GROW UPSCALE THIS EVENING AND DRIVE ENE THROUGH CNTRL IN
LT TONIGHT. GIVEN CONCURRENT LACK OF LL FLW NORTH OF COMPOSITE BNDRY
AND INHERENT POOR MSTR FLUX LOCALLY...HAVE AGAIN TRUNCATED POPS
SHARPLY THROUGH 06Z YET RETAINED THE CAT RAMP THEREAFTER AS MUCH BTR LL
MASS FLUX SHLD MATERIALIZE SW THIRD TWD 09Z AND BEYOND IN ACCORDANCE
W/NR TERM GUIDANCE PROGS. EXTENT OF CAT POPS LIKELY TOO GENEROUS YET
WILL AWAIT LTR GUIDANCE AND MONITOR UPSTREAM CONV EVOLUTION THIS
EVENING BFR TRIMMING FURTHER IF NEEDED.
ERLY VEERING TO SELY FLW NR TERM AT THE TERMINALS AGAIN POINTS TO
IFR CIG DVLP LTR THIS EVENING AND LIKELY LIFR CONDS WILL BE REACHED
SHLD SHRA/EMBEDDED TSRA DVLP AFT 06Z AS NR TERM GUIDANCE IMPLIES.
HWVR MORE SIG ISSUE LOOKS TO BE STG AND GUSTY SWRLY GRADIENT FLW BY
LT THU MORNING AS WARM SECTOR FINALLY MIXES NWD THROUGH THE
TERMINALS. GUSTS TO 25-30KTS LIKELY BY AFTN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...JT
SHORT TERM...AGD
LONG TERM...MCD
UPDATE/AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
105 PM CDT TUE APR 7 2015
.UPDATE...
ISSUED AT 105 PM CDT TUE APR 7 2015
FRONTAL BOUNDARY STALLED ACROSS FAR NORTHERN MO WITH TEMPERATURES
TO THE NORTH IN THE 40S WITH A NORTHEAST WIND AND TO THE SOUTH IN
THE 60S TO LOWER 70S WITH A SOUTH WIND. SPC MESO ANALYSIS
INDICATES 850 MB MOISTURE TRANSPORT WAS INCREASING OVER THIS
BOUNDARY AND SHOWERS AND A FEW THUNDERSTORMS HAVE ERUPTED IN
CENTRAL/NORTHERN IA AND INTO EXTREME SW MN. THE HRRR MODEL
INDICATES SHOWERS AND A FEW THUNDERSTORMS WILL INCREASE THE DVN
CWA AS THE AFTERNOON PROGRESSES...ESPECIALLY ACROSS OUR NORTHERN
HALF CLOSER TO THE 850 MB BOUNDARY. HAVE ALREADY UPDATED TO LOWER
TEMPERATURES SOME MORE...WITH MAXIMUM TEMPERATURES NOT REACHED
UNTIL TOWARDS EVENING AS LOW PRESSURE ADVANCES TOWARDS KANSAS CITY
AND WINDS BECOME MORE EASTERLY...RATHER THAN NORTHEAST.
UPDATE ISSUED AT 1005 AM CDT TUE APR 7 2015
HAVE MADE SEVERAL CHANGES TO THE GRIDS...ADDING AREAS OF DENSE FOG
IN OUR SOUTHERN CWA...GOING DRY THIS MORNING...LOWERING TEMPERATURES
AND DEWPOINTS BY SEVERAL DEGREES. COLD FRONT THAT MOVED THROUGH
THE CWA OVERNIGHT WAS STALLED ACROSS EXTREME NORTHERN MO. AS EXPECTED
CONVECTION FORMED SOUTH OF OUR CWA AND CURRENTLY WAS MOVING THROUGH
THE ST. LOUIS METRO AREA. SUBSIDENCE IN THE WAKE OF THE MCS WAS
KEEPING THE DVN CWA DRY THIS MORNING. IN THE MEANTIME...DEWPOINTS
IN THE 60S SOUTH OF THE BOUNDARY WAS OVERRUNNING THE FRONT AND
PRODUCING WIDESPREAD LOW STRATUS. THIS ALONG WITH A NORTHEAST WIND
WAS BRINGING DRIER AIR INTO MOST OF THE CWA AND KEEPING TEMPERATURES
COOLER THAN FORECAST. THE MODELS CONTINUE TO STRUGGLE WITH THE DRY AIR.
LOW PRESSURE IN KS WILL BE MOVING TO NEAR KANSAS CITY BY EVENING
AND INITIAL CONVECTIVE DEVELOPMENT SHOULD OCCUR AHEAD OF THIS LOW
IN NW MO EARLY THIS AFTERNOON...AND THEN SPREAD NORTHEAST INTO THE
DVN CWA AS THE AFTERNOON PROGRESSES. HOWEVER...LOW STRATUS WILL BE
PERSISTENT THROUGH THE DAY SO THUNDERSTORMS WILL BE ELEVATED AND
THERE IS THE POTENTIAL FOR SMALL HAIL ESPECIALLY THIS EVENING.
THE DENSE FOG IN OUR SOUTHERN CWA SHOULD IMPROVE BY NOON AND A
SPECIAL WEATHER STATEMENT IS IN EFFECT TO COVER THIS SITUATION.
&&
.SYNOPSIS...
ISSUED AT 252 AM CDT TUE APR 7 2015
PORTIONS OF EASTERN IOWA AND NORTHERN ILLINOIS SAW THE FIRST REAL
THUNDERSTORM ACTIVITY OF THE YEAR WITH CELLS FIRING ON THE NOSE OF
MOISTURE TRANSPORT THAT QUICKLY THEN VEERED INTO INDIANA EARLY THIS
MORNING. IN ITS WAKE...LOW LEVELS ARE SATURATED...WITH LIFT
PRODUCING SHALLOW RAINS AND DRIZZLE OVER MUCH OF THE CWA THIS
MORNING. ANOTHER BRANCH OF MOISTURE TRANSPORT IS AIMED AT NORTHWEST
MISSOURI THROUGH EASTERN NEBRASKA...WHERE NEW THUNDERSTORMS ARE
BEGINNING TO FORM. THIS NEXT THRUST OF RAINFALL IS LIKELY TO IMPACT
OUR CWA TODAY AND TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CDT TUE APR 7 2015
ALL ELEMENTS OF THE FORECAST ARE CHALLENGING TODAY...AS THE SHARP
CONTRAST IN TEMPERATURES ALONG THE FRONT COMBINE WITH HIGHLY
VARIABLE CONVECTIVE SIGNALS IN MODEL DATA...WHILE WE BEGIN THE
PERIOD WITH NARROW...BUT LONG BANDS OF DRIZZLE AND LIGHT RAIN. IN
ANY CASE...AS ADVERTISED...IT WILL BE A DAMP DAY...AND COULD BE
QUITE STORMY BEFORE IT IS OVER. WITH THUNDERSTORMS ALREADY FORMING
OVER NORTHWEST MISSOURI INTO SOUTHEASTERN NEBRASKA...IT APPEARS THE
CAPPING INDICATED BY THE 00Z NAM IS OVER DONE. THUS...I AM THINKING
THE 00Z ECMWF SOLUTION MAY BE CLOSEST TO REALITY TONIGHT. THERE WILL
BE AMPLE MUCAPE AVAILABLE FOR STORMS TODAY...ALL DAY AND ALL NIGHT.
HOWEVER...THE SURFACE BOUNDARY SHOULD NOT LIFT NORTH THROUGH THE
DAY...AND I FEEL STORMS WILL BE MOST ROBUST ON THE SOUTHERN FLANK OF
WHERE THE PRIMARY RAIN AREA TRACKS. THAT IS SUPPORTED BY THE 00Z
ECMWF...BUT IS ODDLY INVERTED ON SOME MODELS TODAY...SHOWING THE
MOST INTENSE CONVECTION ON THE NORTH FLANK OF RAIN...WHICH WOULD BE
VERY ODD GIVEN INFLOW FROM THE SOUTH/SOUTHWEST. THUS...WITH A LOW
TRACKING ALONG THE IOWA /MISSOURI BORDER TODAY...THAT PLACES THE CWA
INTO A SYNOPTICALLY FAVORED LOCATION FOR SHOWERS AND
THUNDERSTORMS...OCCURRING ON AN ELEVATED FRONTAL SURFACE. I WILL
INCREASE POPS FROM WEST TO EAST AFTER MID MORNING...WITH LIKELY
COVERAGE OVER THE NORTHERN 2/3RDS OF THE CWA IN THE AFTERNOON AND
EVENING. OVERNIGHT...THE BOUNDARY LINGERS OVERHEAD...WITH MUCAPE
STILL AVAILABLE...BUT THE MOISTURE TRANSPORT/LLJ SHOULD BE FOCUSED
MORE TO THE EAST BY THEN. WHILE THE NEXT ROUND OF SYNOPTIC LIFT WILL
NOT ARRIVE TO LATER WEDNESDAY. POPS WILL BE NEEDED THROUGH OUT THE
DAY DAY DUE TO THE LOW LEVEL PROCESSED CONTINUING TO PRODUCE THE
LIGHT RAIN/DRIZZLE BEFORE ANY CONVECTION ARRIVES.
TEMPERATURES TODAY WILL BE BASED ON 10 TO 15 DEGREE MODEST RISE
DIURNALLY UNDER CLOUDY SKIES. FOR THE NORTH...THIS MEANS MOST OF THE
DAY SPENT IN THE 40S...WITH EAST WINDS. THE SOUTH IS MOST LIKELY TO
SQUEEZE OUT A MILD DAY AS THE ELEVATED RAIN PROCESSES SHOULD NOT
CONSISTENTLY AFFECT THEM. TONIGHT MUCH LIKE THE CURRENT
NIGHT...LAKE ENHANCED COLD AIR WILL SWEEP SOUTH AS THE LOW PRESSURE
WAVE RIDES TO THE EAST. UPPER 30S NORTH TO LOWER 50S SOUTH ARE
SUPPORTED BY MODEL DATA AND SEEM A LIKELY FIT.
ERVIN
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 252 AM CDT TUE APR 7 2015
A PROGRESSIVE PATTERN IS SETTING UP FOR THE LONG TERM WITH A PAIR
OF UPPER LEVEL TROUGHS PROGGED THROUGH THE CENTRAL U.S. INTO EARLY
NEXT WEEK. PLENTY OF OPPORTUNITIES FOR RAIN AND A FEW CHANCES FOR
SEVERE WEATHER ARE INDICATED.
WEDNESDAY...THE UPPER LEVEL TROUGH TAKES SHAPE IN THE INTERMOUNTAIN
WEST WHILE SURFACE LOW PRESSURE AND THE LOW-LEVEL JET FOCUS ON
LIFTING A WARM FRONT INTO THE CWA. THE SURFACE BOUNDARY LINGERS IN
THE SOUTHERN CWA WHILE THE 850 MB FRONT IS FORECAST TO MOVE INTO
THE NORTHERN CWA. INSTABILITY AND SHEAR ARE SUFFICIENT FOR A
SEVERE WEATHER THREAT PRIMARILY IN THE SOUTHERN PART OF THE CWA
LATER IN THE DAY AND OVERNIGHT. THIS WILL DEPEND THE ON THE NATURE
OF CONVECTIVE DEVELOPMENT EARLIER IN THE DAY TO THE SOUTHWEST IN
THE SOMEWHAT CAPPED ENVIRONMENT. MID-LEVEL LAPSE RATES ARE VERY
STEEP WHICH WOULD INDICATE POTENTIAL FOR RAPIDLY DEVELOPING STORMS.
THURSDAY...THE UPPER LEVEL TROUGH MOVES INTO THE MIDWEST AND
INTENSIFIES WHILE THE INSTABILITY AXIS...STEEP MID-LEVEL LAPSE
RATES AND HIGH SHEAR ENVIRONMENT PERSIST OVER THE AREA. MODELS
DISAGREE SOMEWHAT IN THE DETAILS OF THE TIMING AND PRECISE TRACK
OF THE SURFACE LOW AND COLD FRONTAL PASSAGE...BUT THE CONSENSUS
FAVORS THE LOW MOVING THROUGH OR NEAR THE CWA NEAR PEAK HEATING.
THIS SUGGESTS THE FULL RANGE OF SEVERE WEATHER THREATS...AND GIVEN
THE ENVIRONMENT AND TIME OF YEAR...THIS COULD BE A SIGNIFICANT
EVENT WITH RAPIDLY DEVELOPING AND FAST-MOVING SUPERCELLS.
FRIDAY AND SATURDAY...THE TROUGH MOVES EAST AND HIGH PRESSURE
BUILDS INTO THE AREA WITH DRY AND PLEASANT WEATHER.
SUNDAY AND MONDAY...THE SECOND TROUGH BEGINS TO TAKE SHAPE IN THE
WESTERN U.S. AND MOVES INTO THE MIDWEST. INSTABILITY IS NOT TOO
IMPRESSIVE...AND CURRENT MODEL FORECASTS SEEM TO SUGGEST MORE OF
A HEAVY RAIN THREAT THAN A SEVERE THREAT. BUT THAT COULD CHANGE
BETWEEN NOW AND LATE THIS WEEKEND. WOLF
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 105 PM CDT TUE APR 7 2015
MAINLY IFR CONDS THROUGH THE TAF CYCLE ALONG WITH INCREASING
SHOWERS AND THUNDERSTORMS. NORTHEAST TO EAST WINDS 10 TO 20 KNOTS
THROUGH THE TAF CYCLE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...WOLF
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
922 PM MDT WED APR 8 2015
.UPDATE...
ISSUED AT 922 PM MDT WED APR 8 2015
ISSUED A LARGE UPDATE TO AMEND SKY...WEATHER AND POP GRIDS FOR
THIS EVENING THROUGH TOMORROW EVENING. FOG/STRATUS HAS PUSHED
FARTHER SOUTH THAN MOST GUIDANCE ONCE AGAIN. HRRR AND RUC HAVE
LOCKED ONTO STRATUS WHILE OTHER GUIDANCE PERSISTS WITH A POOR
FORECAST. ALSO...INCREASED POPS TO ACCOUNT FOR SHOWERS...STORMS
AND DRIZZLE TONIGHT AND SHOWERS/DRIZZLE TOMORROW. THE FOG/DRIZZLE
SETUP IS ESSENTIALLY IDENTICAL TO THE PREVIOUS TWO NIGHTS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 153 PM MDT WED APR 8 2015
AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS
TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE
MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM
EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL
MOVE IN BEHIND THE TROUGH THURSDAY.
PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY.
DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS
TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE
OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE
BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING.
DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF
SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA
ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL
BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE
NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH
CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP
THOSE IN THE FORECAST.
BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA
LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT.
VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE
NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY
MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND
SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA.
MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING.
EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX
TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO
THE LOWER 50S TO MID 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 107 PM MDT WED APR 8 2015
SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL
RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT.
TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL.
SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A
CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT.
BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO
2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE
PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE
HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN
BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY
WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN
THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY
DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL.
CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE
SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A
CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT
EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME
NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT
SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES
WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS
FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY
MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE
AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY.
NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN
NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH
TEMPERATURES ABOVE TO MUCH ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 553 PM MDT WED APR 8 2015
STRATUS WILL BE AN ISSUE TONIGHT. STRATUS ADVANCES SOUTHEAST
TOWARD KGLD BUT UNSURE OF EXACT ARRIVAL TIME. FOR NOW...FORECAST
ARRIVAL BETWEEN 04-06Z. LATEST HRRR FORECAST INDICATES STRATUS
REACHES KGLD WHILE OTHER GUIDANCE IS LESS PESSIMISTIC SO SIDED
WITH HRRR WHICH HANDLED STRATUS WELL LAST NIGHT. ANOTHER CONCERN
IS A COLD FRONT SLIDES THROUGH EARLY TOMORROW MORNING. THIS LEADS
TO LIFTING STRATUS AS DRIER AIR ADVECTS IN. IN ADDITION TO DRIER
AIR...ANTICIPATE GUSTY NORTHWEST WINDS TO DEVELOP BY LATE MORNING.
AS FOR PRECIPITATION CHANCES...DO NOT FEEL PRECIPITATION WILL BE
WIDESPREAD ENOUGH THIS EVENING TO INCLUDE A MENTION IN TAFS AT
THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...RRH
SHORT TERM...FS
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS WICHITA KS
710 PM CDT WED APR 8 2015
.MESOSCALE DISCUSSION...
ISSUED AT 710 PM CDT WED APR 8 2015
MAIN SUPERCELL ACROSS BARBER COUNTY SEEMS TO BE THE MAIN EVENT
ACCORDING TO THE LATEST TRENDS ON RADAR AND NWP. LOOKING AT
CONVECTIVE TRENDS ACROSS OKLAHOMA...THEY HAVE BEEN HEADING
DOWNWARD...AS IS EVEN THE CASE IN THE BARBER/COMANCHE STORM.
LOW LEVEL FLOW HAS BEEN INCREASING WHICH HAS BEEN SUPPORTING
BRIEF TORNADOES WITH THAT STORM WITH INCREASED LOCAL HELICITY.
EXTRAPOLATING THE CURRENT MOVEMENT WOULD BRING IT INTO THE
FORECAST AREA /KINGMAN COUNTY/ ABOUT 01Z.
SPC ANALYSIS/LAPS ANALYSIS AND RAP FORECASTS FOR THE LAST 3 RUNS
CONTINUE TO SHOW A TRANSITION OF THE MOST FAVORED AREA FOR
TORNADOES TO HAVE SHIFTED WEST. THE LOW LEVEL HELICITY AREA
REMAINS WEST OF THE FORECAST AREA ASSOCIATED WITH THE TRIPLE
POINT.
MOREOVER...SEEMS THAT AS THE STORMS MOVE EAST THEY GET INTO AN
ENVIRONMENT THAT HAS DECREASED HELICITY AND IS JUST NOT AS
FAVORABLE GIVEN THAT THE EARLIER CONVECTION MAY HAVE ALTERED THE
ENVIRONMENT ENOUGH TO DECREASE THE THREAT.
IN SUMMARY...THINK THE STORM THAT IS ONGOING IS THE MAIN THREAT AS
ARE SOME OF THE STORMS COMING FROM OKLAHOMA.
OTHERWISE...CONFIDENCE IS DECREASING IN THE AMPLITUDE OF THE
THREAT FOR THE FORECAST AREA.
KRC
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 245 PM CDT WED APR 8 2015
THIS EVENING-TONIGHT: LATEST SURFACE ANALYSIS SHOWS MAIN SURFACE
BOUNDARY LOCATED JUST TO THE SE OF ICT METRO...MAINLY FROM EUREKA TO
MULVANE TO WELLINGTON. THE INITIAL ROUND OF CONVECTION HAS ALREADY
BEGUN OVER SRN KS...WITH MULTICELL STORMS PRODUCING MAINLY HAIL AND
DAMAGING WINDS. THIS INITIAL ROUND OF STORMS WILL STAY IN THE WARM
SECTOR ACROSS SE KS FOR THE EARLY AFTERNOON HOURS. WITH THE MAIN
CONCERN FROM THIS ROUND BEING LARGE HAIL AND DAMAGING WINDS GIVEN
THE UNSTABLE AIRMASS AND FAVORABLE BULK SHEAR.
LATEST SHORT TERM HI-RES MODELS CONTINUE TO SHOW THE BOUNDARY
RETROGRADING BACK TO THE NORTH EARLY THIS EVENING BETWEEN 21Z-02Z...
WITH A SIGNIFICANT INCREASE OF LOW LEVEL CAPE BACK TOWARDS THE KICT
METRO. THIS IN CONJUNCTION WITH THE INCREASE IN BULK SHEAR FROM THE
INCOMING DISTURBANCE COUPLED WITH THE LOW LEVEL JET WILL PRODUCE A
SCENARIO VERY FAVORABLE FOR TORNADIC SUPERCELLS TO DEVELOP ALONG THE
DRY LINE AS IT SHARPENS FOR AREAS TO THE WEST AND SW OF SOUTH
CENTRAL KS. THIS WILL LEAD TO A SECOND POSSIBLY MORE SIGNIFICANT
CHANCE OF STORMS FOR LATER THIS EVENING WELL AFTER DARK. LATEST HI-
RES MODEL CONTINUE TO SHOW 0-8KM SHEAR IS VERY FAVORABLE FOR
SUPERCELLS AND POSSIBLE LONG TRACK TORNADOES. INCREASED MLCAPE TO
2000-2500 J/KG AND LOWERING LCL LEVELS WOULD ALSO SUGGEST A
STRONG TORNADO THREAT AS WELL. SO THIS SETUP WOULD STILL LEAD TO
HIGH LIKELYHOOD OF THE TORNADO THREAT CONTINUING WELL AFTER DARK
FOR AREAS AREAS ACROSS SOUTH CENTRAL KS...MAINLY ALONG OR SOUTH OF
HIGHWAY 54/400.
EXPECT THE SEVERE CONVECTION TO CONTINUE FOR THE OVERNIGHT
HOURS...WITH PROGRESSION OF THE STORMS TO THE EAST INTO THE FLINT
HILLS AND SOUTHEAST KS. DEEP LAYER SHEAR LOOKS TO WANE SOME AFTER
MIDNIGHT...WHICH WILL LIKELY SHIFT THE SEVERE WEATHER MODE TO MORE
OF A LARGE HAIL AND DAMAGING WIND CHANCE.
THU: COULD SEE SOME LINGERING STORMS ACROSS PORTIONS OF SOUTHEAST
KS IN THE MORNING HOURS AS THE DRY LINE/BOUNDARY SURGES EAST INTO
WRN MO. IT NOT COMPLETELY OUT OF THE REALM OF POSSIBILITY THAT
SOME LINGERING STRONG STORMS WILL BE OVER SE KS...BUT THIS CHANCE
WILL BE SHORT LIVED. EXPECT THE THU AFTERNOON SEVERE THREAT TO
OVER EXTREME SE KS AND MAINLY IN SW MO. WITH THE REST OF THE
REGION SEEING NICE WEATHER RETURN TO THE AREA...WITH DRIER AIR
MOVING INTO THE AREA.
FRI-EARLY SAT: A COUPLE OF NICE DAY EXPECTED FOR FRI AND EARLY SAT
AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE PLAINS INTO THE
SRN PLAINS. THIS WILL LEAD TO NEAR SEASONAL TEMPS AND SUNNY SKIES
IN MOST LOCATIONS. AS SATURDAY PROGRESSES...LOW LEVEL MOISTURE WILL
RAPIDLY RETURN TO THE AREA FOR AREAS WEST OF THE FORECAST AREA FOR
SAT AFTERNOON. COULD SEE SHOWERS AND THUNDERSTORMS DEVELOP TO THE
WEST OF THE AREA AND POSSIBLY MOVE INTO SOME OF THE WRN PORTIONS OF
COUNTY WARNING AREA BY SAT EVENING.
SAT NIGHT: ISENTROPIC LIFT AND MOISTURE RETURN WILL CONTINUE OVER
THE WRN HALF OF THE FORECAST AREA FOR SAT NIGHT. THIS MAY LEAD TO
A CHANCE OF SHOWERS AND THUNDERSTORM COVERAGE INCREASING ACROSS
MOST OF THE AREA FOR SAT NIGHT.
KETCHAM
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 245 PM CDT WED APR 8 2015
MEDIUM RANGE MODELS DO DIFFER SOME ON HOW SUN AND MON WILL PLAY OUT.
BUT BOT MODELS SUGGEST ANOTHER CHANCE OF THUNDERSTORMS ON
SUNDAY...WITH POSSIBLE STRONG TO SEVERE STORMS. THE ECMWF LOOKS TO
CLEAR THINGS OUT ON MON...WHILE THE GFS SUGGESTS A BOUNDARY MAY BE
STATIONARY ACROSS SRN KS FOR MON.
KETCHAM
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1208 PM CDT WED APR 8 2015
CONVECTION NOW DEVELOPING OVER OKLAHOMA WILL MOVE NORTHEAST INTO
THE AIRSPACE AND CONTINUE WITH SEVERAL ROUNDS THROUGH 6Z. THIS
WILL AFFECT ALL AIRPORTS AND FIELDS ALONG AND SOUTHEAST OF KSLN-
KVNX. THESE STORMS WILL BE SEVERE AND SHOULD BE AVOIDED.
FOG...WHICH CONTINUES TO AFFECT KHUT...KRSL...KSLN HAS BEEN SLOW
TO BURN OFF. THINK IT SHOULD BE GONE BY 21Z. VFR CONDITIONS SHOULD
PERSIST THROUGH 03Z...WITH FOG REDEVELOPMENT THERE POSSIBLE
THROUGH 12Z.
THE COLD FRONT WILL CLEAR THE AREA BY 14Z.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CDT WED APR 8 2015
MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY.
EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL
BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS.
HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS
WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG
WITH RH`S IN THE 35-45 PERCENT RANGE. WIND SPEEDS THU AFTERNOON
WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 56 71 39 68 / 60 10 0 0
HUTCHINSON 52 67 37 68 / 40 10 0 0
NEWTON 54 67 38 67 / 50 10 0 0
ELDORADO 60 69 39 68 / 70 10 10 0
WINFIELD-KWLD 61 72 40 68 / 80 10 0 0
RUSSELL 46 63 35 67 / 20 10 10 0
GREAT BEND 46 64 35 67 / 20 10 0 0
SALINA 50 65 35 68 / 30 20 10 0
MCPHERSON 51 66 36 67 / 40 10 10 0
COFFEYVILLE 65 76 42 68 / 90 30 10 0
CHANUTE 64 73 41 68 / 90 30 10 0
IOLA 63 72 40 67 / 90 30 10 0
PARSONS-KPPF 64 74 41 68 / 90 30 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
553 PM MDT WED APR 8 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 153 PM MDT WED APR 8 2015
AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS
TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE
MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM
EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL
MOVE IN BEHIND THE TROUGH THURSDAY.
PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY.
DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS
TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE
OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE
BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING.
DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF
SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA
ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL
BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE
NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH
CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP
THOSE IN THE FORECAST.
BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA
LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT.
VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE
NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY
MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND
SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA.
MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING.
EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX
TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO
THE LOWER 50S TO MID 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 107 PM MDT WED APR 8 2015
SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL
RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT.
TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL.
SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A
CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT.
BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO
2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE
PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE
HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN
BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY
WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN
THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY
DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL.
CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE
SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A
CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT
EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME
NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT
SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES
WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS
FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY
MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE
AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY.
NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN
NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH
TEMPERATURES ABOVE TO MUCH ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 553 PM MDT WED APR 8 2015
STRATUS WILL BE AN ISSUE TONIGHT. STRATUS ADVANCES SOUTHEAST
TOWARD KGLD BUT UNSURE OF EXACT ARRIVAL TIME. FOR NOW...FORECAST
ARRIVAL BETWEEN 04-06Z. LATEST HRRR FORECAST INDICATES STRATUS
REACHES KGLD WHILE OTHER GUIDANCE IS LESS PESSIMISTIC SO SIDED
WITH HRRR WHICH HANDLED STRATUS WELL LAST NIGHT. ANOTHER CONCERN
IS A COLD FRONT SLIDES THROUGH EARLY TOMORROW MORNING. THIS LEADS
TO LIFTING STRATUS AS DRIER AIR ADVECTS IN. IN ADDITION TO DRIER
AIR...ANTICIPATE GUSTY NORTHWEST WINDS TO DEVELOP BY LATE MORNING.
AS FOR PRECIPITATION CHANCES...DO NOT FEEL PRECIPITATION WILL BE
WIDESPREAD ENOUGH THIS EVENING TO INCLUDE A MENTION IN TAFS AT
THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ253-254.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
225 PM CDT TUE APR 7 2015
...UPDATED FOR LONG TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST
KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE
FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG
AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST
THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE
FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE
RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY
TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER
SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH
ABOUT 8 AM CDT.
THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING
HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON.
FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR
ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS
MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN
PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS
GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT
DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN
THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE
MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF
THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR
THAT AREA.
TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG
AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS.
MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION
MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS
CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT
COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED
THUNDERSTORMS IN THAT AREA AS WELL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 208 PM CDT TUE APR 7 2015
THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL
PASS ACROSS CENTRAL KANSAS BY THURSDAY AFTERNOON, WITH THE
ACCOMPANYING COLD FRONT PASSING IN THE MORNING. COOL, SURFACE HIGH
PRESSURE WILL BUILD INTO WESTERN KANSAS THROUGH FRIDAY. WITH LIGHT
WINDS THURSDAY NIGHT, TEMPERATURES WILL FALL INTO THE 30S, WITH
SOME READINGS CLOSE TO FREEZING FROM DODGE CITY WESTWARD AND
NORTHWARD. HIGHS WILL BE IN THE 60S THURSDAY AND FRIDAY.
THERE IS CONSIDERABLE UNCERTAINTY WITH RESPECT TO THE EVOLUTION OF
NORTHERN AND SOUTHERN STREAM SHORTWAVE TROUGHS PROGRESSING INTO
THE DESERT SOUTHWEST AND NORTHERN ROCKIES BY SUNDAY. SURFACE
PRESSURES WILL LOWER IN THE LEE OF THE ROCKIES IN RESPONSE TO
THESE SYSTEMS LATER FRIDAY INTO SATURDAY AND SUNDAY, ALONG WITH A
GRADUAL INCREASE IN LOW LEVEL MOISTURE. A FEW RAIN SHOWERS AND
THUNDERSTORMS CAN`T BE RULED OUT STARTING SATURDAY, WITH CHANCES
LINGERING INTO SUNDAY NIGHT. COVERAGE OF SHOWER ACTIVITY IS VERY
UNCERTAIN DUE TO THE WIDE RANGE OF MODEL SOLUTIONS WITH THE UPPER
TROUGH PROGRESSING FROM THE DESERT SOUTHWEST TOWARD THE SOUTHERN
HIGH PLAINS. OVERNIGHT LOWS WILL OF COURSE BE INCREASING THROUGH
SUNDAY DUE TO THE LEE TROUGHING, SOUTH WINDS AND HIGHER DEWPOINTS.
A MORE AMPLIFIED UPPER LEVEL TROUGH WILL BEGIN TO DEVELOP OVER
THE WESTERN UNITED STATES MONDAY THROUGH WEDNESDAY OF NEXT WEEK,
RESULTING IN LEE TROUGHING ON THE HIGH PLAINS, SOUTHERLY WINDS
AND WARMER TEMPERATURES. CHANCES OF SHOWERS AND THUNDERSTORMS WILL
INCREASE BY MID TO LATE NEXT WEEK AS THE UPPER TROUGH GETS CLOSER
AND ASSOCIATED COLD FRONT APPROACHES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1119 AM CDT TUE APR 7 2015
AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF
NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB
AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH
SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS
SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL
KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED
NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE
OBSERVATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 83 45 66 / 10 10 10 10
GCK 46 80 41 63 / 10 10 10 10
EHA 47 81 42 64 / 10 0 10 10
LBL 46 85 43 66 / 10 0 0 0
HYS 44 69 45 62 / 20 20 20 20
P28 55 86 52 72 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 9 PM CDT /8 PM MDT/
WEDNESDAY FOR KSZ061>063-074>078-084>089.
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ080-081-090.
&&
$$
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
1256 PM CDT TUE APR 7 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 334 AM CDT TUE APR 7 2015
IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING
NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE
PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST-
CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM
THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH
WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING
THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY
ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION
FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN
QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES
LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF
ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE
AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT
THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD
DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR
ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH
AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT
DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE
TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS
BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL
BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW
LEVEL SHEAR.
SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED
AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE
CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM.
THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO
THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS.
THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN
QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE
THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO
DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT
OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED
AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE
CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT
RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT
DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED
AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR
PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM
CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT
SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW
LEVEL MOISTURE.
STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135.
THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER
WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY
SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU
MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP
AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI
ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN
ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A
SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE
PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST
AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR
SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR
MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE
THE BEST CHANCES AT SHOWERS AND STORMS.
LAWSON
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1253 PM CDT TUE APR 7 2015
VARIABLE WEATHER WILL BE NOTED DURING THIS FORECAST PERIOD. A
SURFACE FRONT CURRENTLY RESIDES ALONG THE FLINT HILLS AND SHOULD
RETROGRADE BACK INTO SOUTH CENTRAL KANSAS ON WEDNESDAY. THE INFLUX
OF HIGHER DEWPOINTS AND THE FORECAST UPLOPE FLOW WILL PRODUCE LOW
STRATUS OR STRATOCUMULUS DURING THE OVERNIGHT AND EARLY MORNING
HOURS WEDNESDAY. VSBYS SHOULD ALSO SEE SOME RESTRICTIONS WITH THE
LOW CLOUDS. IFR CONDITIONS ARE POSSIBLE AT MOST LOCATIONS SO KEEP
AN EYE ON THE FORECAST. STRONG THUNDERSTORMS ARE POSSIBLE AT CNU
THIS EVENING AND AT MOST LOCATIONS ON WEDNESDAY.
&&
.FIRE WEATHER...
ISSUED AT 310 PM CDT MON APR 6 2015
THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE
LOOKS TO BE THURSDAY.
EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE
IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO
STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND
NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON
HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 83 64 84 55 / 10 10 30 30
HUTCHINSON 80 56 80 51 / 0 10 30 20
NEWTON 83 58 81 53 / 10 10 30 30
ELDORADO 84 65 82 59 / 10 20 30 40
WINFIELD-KWLD 85 65 83 60 / 10 10 30 30
RUSSELL 71 48 70 47 / 10 10 20 20
GREAT BEND 75 50 74 47 / 10 10 20 10
SALINA 75 52 73 50 / 10 10 30 30
MCPHERSON 79 55 77 50 / 10 10 30 30
COFFEYVILLE 83 65 81 65 / 10 20 30 40
CHANUTE 83 65 80 64 / 10 30 30 50
IOLA 83 64 79 63 / 10 30 40 50
PARSONS-KPPF 83 65 81 64 / 10 20 30 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1150 AM CDT TUE APR 7 2015
...UPDATED FIRE WEATHER DISCUSSION...
.SYNOPSIS...
ISSUED AT 1119 AM CDT TUE APR 7 2015
AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF
NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB
AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH
SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS
SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL
KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED
NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE
OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST
KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE
FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG
AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST
THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE
FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE
RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY
TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER
SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH
ABOUT 8 AM CDT.
THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING
HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON.
FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR
ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS
MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN
PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS
GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT
DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN
THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE
MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF
THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR
THAT AREA.
TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG
AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS.
MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION
MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS
CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT
COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED
THUNDERSTORMS IN THAT AREA AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 319 AM CDT TUE APR 7 2015
AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST
WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY
NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS
THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY
AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT
EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE
POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE
OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE
REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING
DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF
THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN
ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE
DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY
CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO
WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD
ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS
FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING
SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF
THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF
SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING.
A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS
HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS
SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO
DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE
MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR
DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY
AFTERNOON.
ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE
INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS
THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH
PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS
FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO
THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND
WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY
NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST
UNITED STATES.
AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER
70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE
THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO
RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER
50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED
BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS
THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S
EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND
WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE
AROUND 70 DEGREES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1119 AM CDT TUE APR 7 2015
AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF
NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB
AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH
SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS
SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL
KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED
NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE
OBSERVATIONS.
&&
.FIRE WEATHER...
ISSUED AT 1149 AM CDT TUE APR 7 2015
A DRYLINE WILL BE LOCATED ACROSS SOUTH CENTRAL KANSAS BY LATE DAY
WEDNESDAY. UNSEASONABLY WARM CONDITIONS COMBINED WITH DRY AIR
SPREADING EAST ACROSS SOUTHWEST KANSAS BEHIND THIS DRYLINE
WEDNESDAY AFTERNOON WILL RESULT IN RELATIVE HUMIDITY VALUES
FALLING BACK INTO THE 10 TO 15 PERCENT RANGE. THESE LOW RELATIVE
HUMIDITIES ALONG WITH GUSTY SOUTHWEST WINDS OF 20 TO 25 MPH WILL
CREATE A FAVORABLE ENVIRONMENT FOR ANY OPEN FIRES TO SPREAD
QUICKLY AND BE DIFFICULT TO CONTROL. AS A RESULT WILL BE UPGRADING
THE MOST OF THE FIRE WEATHER WATCH TO A RED FLAG WARNING. OUT DOOR
BURNING ON WEDNESDAY SHOULD BE AVOIDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 79 48 83 46 / 0 10 10 10
GCK 77 46 80 42 / 0 10 10 10
EHA 83 47 81 43 / 0 10 0 10
LBL 84 46 85 44 / 0 10 0 0
HYS 69 44 69 46 / 10 20 20 20
P28 83 55 86 53 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 9 PM CDT /8 PM MDT/
WEDNESDAY FOR KSZ061>063-074>078-084>089.
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ080-081-090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...BURGERT
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 AM CDT TUE APR 7 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1119 AM CDT TUE APR 7 2015
AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF
NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB
AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH
SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS
SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL
KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED
NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE
OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST
KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE
FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG
AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST
THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE
FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE
RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY
TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER
SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH
ABOUT 8 AM CDT.
THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING
HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON.
FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR
ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS
MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN
PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS
GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT
DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN
THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE
MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF
THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR
THAT AREA.
TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG
AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS.
MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION
MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS
CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT
COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED
THUNDERSTORMS IN THAT AREA AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 319 AM CDT TUE APR 7 2015
AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST
WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY
NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS
THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY
AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT
EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE
POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE
OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE
REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING
DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF
THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN
ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE
DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY
CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO
WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD
ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS
FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING
SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF
THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF
SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING.
A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS
HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS
SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO
DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE
MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR
DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY
AFTERNOON.
ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE
INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS
THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH
PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS
FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO
THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND
WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY
NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST
UNITED STATES.
AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER
70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE
THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO
RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER
50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED
BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS
THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S
EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND
WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE
AROUND 70 DEGREES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1119 AM CDT TUE APR 7 2015
AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF
NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB
AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH
SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS
SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL
KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED
NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE
OBSERVATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 49 84 46 / 0 10 10 10
GCK 79 46 81 42 / 0 10 10 10
EHA 83 47 81 43 / 0 10 0 10
LBL 85 46 85 44 / 0 10 0 0
HYS 70 46 69 46 / 10 20 20 20
P28 85 55 88 53 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ061>063-074>078-080-081-084>090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
614 AM CDT TUE APR 7 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST
KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE
FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG
AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST
THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE
FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE
RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY
TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER
SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH
ABOUT 8 AM CDT.
THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING
HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON.
FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR
ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS
MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN
PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS
GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT
DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN
THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE
MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF
THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR
THAT AREA.
TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG
AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS.
MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION
MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS
CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT
COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED
THUNDERSTORMS IN THAT AREA AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 319 AM CDT TUE APR 7 2015
AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST
WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY
NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS
THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY
AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT
EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE
POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE
OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE
REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING
DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF
THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN
ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE
DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY
CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO
WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD
ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS
FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING
SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF
THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF
SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING.
A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS
HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS
SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO
DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE
MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR
DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY
AFTERNOON.
ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE
INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS
THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH
PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS
FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO
THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND
WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY
NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST
UNITED STATES.
AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER
70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE
THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO
RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER
50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED
BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS
THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S
EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND
WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE
AROUND 70 DEGREES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 612 AM CDT TUE APR 7 2015
DENSE FOG WILL BE OBSERVED ACROSS THE DDC AND GCK TERMINALS
THROUGH 14Z BRINGING LIFR CONDITIONS. SKIES THEN BECOME MOSTLY
CLEAR THIS AFTERNOON. WINDS WILL GENERALLY BE FROM THE NORTH THIS
MORNING INTO THE AFTERNOON, SHIFTING TO THE SOUTHEAST THIS
EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 49 84 46 / 0 10 10 10
GCK 79 46 81 42 / 0 10 10 10
EHA 83 47 81 43 / 0 10 0 10
LBL 85 46 85 44 / 0 10 0 0
HYS 70 46 69 46 / 10 20 20 20
P28 85 55 88 53 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR
KSZ045-046-061>065-075>079.
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ061>063-074>078-080-081-084>090.
&&
$$
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS WICHITA KS
613 AM CDT TUE APR 7 2015
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 334 AM CDT TUE APR 7 2015
IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING
NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE
PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST-
CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM
THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH
WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING
THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY
ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION
FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN
QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES
LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF
ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE
AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT
THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD
DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR
ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH
AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT
DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE
TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS
BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL
BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW
LEVEL SHEAR.
SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED
AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE
CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM.
THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO
THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS.
THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN
QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE
THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO
DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT
OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED
AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE
CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT
RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT
DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED
AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR
PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM
CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT
SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW
LEVEL MOISTURE.
STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135.
THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER
WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY
SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU
MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP
AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI
ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN
ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A
SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE
PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST
AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR
SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR
MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE
THE BEST CHANCES AT SHOWERS AND STORMS.
LAWSON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 609 AM CDT TUE APR 7 2015
POOR AVIATION CONDITIONS WILL CONTINUE TO LINGER ACROSS CENTRAL
KANSAS THIS MORNING AS A COLD FRONT SAGS SLOWLY SOUTHWARD...WITH
LOW CLOUDS AND PATCHY DENSE FOG. THE VISIBILITIES/LOW CLOUDS WILL
GRADUALLY IMPROVE LATER THIS MORNING. MEANWHILE THE COLD FRONT
WILL STALL OUT OVER SOUTHERN KANSAS BY THIS EVENING...WITH
ISOLATED SEVERE STORMS POSSIBLE OVER SOUTHEAST KANSAS. THE FRONT
WILL SLOWLY LIFT NORTHWARD AS A WARM FRONT TONIGHT...AND ONCE
AGAIN LOW CLOUDS COULD FILL IN ALONG AND NORTH OF THE FRONT OVER
CENTRAL KANSAS LATE TONIGHT.
JAKUB
&&
.FIRE WEATHER...
ISSUED AT 310 PM CDT MON APR 6 2015
THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE
LOOKS TO BE THURSDAY.
EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE
IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO
STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND
NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON
HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 83 64 84 55 / 10 10 30 30
HUTCHINSON 80 56 80 51 / 0 10 30 20
NEWTON 83 58 81 53 / 10 10 30 30
ELDORADO 84 65 82 59 / 10 20 30 40
WINFIELD-KWLD 85 65 83 60 / 10 10 30 30
RUSSELL 71 48 70 47 / 10 10 20 20
GREAT BEND 75 50 74 47 / 10 10 20 10
SALINA 75 52 73 50 / 10 10 30 30
MCPHERSON 79 55 77 50 / 10 10 30 30
COFFEYVILLE 83 65 81 65 / 10 20 30 40
CHANUTE 83 65 80 64 / 10 30 30 50
IOLA 83 64 79 63 / 10 30 40 50
PARSONS-KPPF 83 65 81 64 / 10 20 30 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
407 AM CDT Tue Apr 7 2015
.SHORT TERM...(Today and Tonight)
Issued at 407 AM CDT TUE APR 7 2015
Weak shortwave trough seen in water vapor imagery crossing
eastern KS combined with warm advection above cap to create
thunderstorms over northern MO this morning. This appears to be
moving away, but have kept small chances in far
northern/northeastern KS into the morning hours in an area of
isentropic lift above cap. Better chances expected to be to north
of forecast area over Nebraska during the day.
Short range models consistent in bringing surface low from
southwestern KS at 06Z Tuesday into northeast KS by 18Z.
Thereafter it weakens the low into an inverted trough...as lee
trough begins strengthening upstream in eastern CO. Low-level
convergence along surface trough in east central KS late this
afternoon/evening could trigger some surface based thunderstorms
if lift is sufficient to overcome considerable capping inversion.
Despite lack of large scale lifting mechanism, sufficient shear
and instability should exist for the potential of isolated severe
thunderstorms near the trough.
While evening thunderstorm chances diminish after sunset, there is
still a slight chance of elevated storms later tonight with lift up
over the boundary that remains in vicinity of northeast/east central
KS.
Temps today are particularly tricky. Position of surface boundary
and thicker cloud cover expected to hold down highs in far northern
KS while upper 70s and lower 80s expected to the south of boundary.
.LONG TERM...(Wednesday through Monday)
Issued at 407 AM CDT TUE APR 7 2015
Wednesday and Wednesday night continue to be a concern regarding
strong to severe thunderstorms. Models continue to show high
surface dewpoints capped by a strong elevated mixed layer (EML).
This sets the stage for large values of CAPE if a surface parcel
is able to break through the cap. Deep layer shear of 40 to 50 KTS
would be good enough for storms to become supercells. So there
remains a chance for severe storms with large hail, damaging winds
and tornadoes. The question is how limiting with the cap be in
storm coverage. At this point there appears to be two surface
features that may help shower and thunderstorm development. The
first is a warm front that is expected to set up across northern
KS Wednesday morning. Convergence and lift from the low level jet
could cause some elevated storms to develop mainly north of the
front. However all of the moisture seems to be trapped below the
inversion with a lot of dry air above the cap. Because of this
think chances for precip are not that great and have trended POPs
down 5 to 10 percent. The more compelling feature will be a
dryline that is progged to set up across central KS by the
afternoon hours. Models show some mass convergence along this
boundary through the afternoon as well as a modest PV anomaly
lifting out across the central plains. Thinking is this may be
enough forcing that local updrafts are able to break through the
cap. With this in mind, have kept some likely POPs across east
central KS in line with prev forecast, as most model guidance
shows the same idea of storms developing on the dry line and
moving northeast into east central KS through the evening. The
concern however is that coverage could end up being pretty
limited due to the strength of the cap and the forecast of likely
POPs may signal for more widespread storms and severe weather.
For Thursday, the models bring the main upper trough across the
region. Current model runs continue to show the deeper moisture
and instability pushing off to the east early in the day Thursday.
Hove kept some small POPs in through the day for some possible
shower activity with the upper trough axis. Otherwise we should
see cooler and dryer air move in from the northwest with winds
becoming gusty by the early afternoon. Highs are expected to be
around 60 to the lower 70s due to increasing cold air advection.
Friday and Friday night look to be dry and cool as surface ridging
passes over the region. Models show return flow setting up for
Saturday and Sunday. Think precip chances Saturday are only 20
percent due to no strong forcing progged by the models. However
with warm air advection Saturday night and a surface wave moving
through the region Sunday and Sunday night, precip chances will be
on the increase. The best forcing looks to affect the forecast
area Sunday afternoon and Sunday evening as models forecast
increasing PVA. Think any lingering precip will be moving out of
the area Monday. Temps through the weekend look to be seasonable
as models keep the really warm air across the southwest.
&&
.AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening)
Issued at 647 PM CDT MON APR 6 2015
Complicated forecast leading to quite low confidence. Limiting
stratus nearly out of all terminals but easterly winds developing
should allow for redevelopment by 06Z. Guidance struggling to
various degrees but stayed closer to RAP and GFS for build down to
IFR and LLWS as jet increases. At this point convective chances in
the 04Z-14Z period look too low to include, with TOP and FOE of
more concern than MHK. Southwest winds should mix down as low
pressure moves near/just NW of terminals around 18Z for return to
VFR.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Wolters
AVIATION...65
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT TUE APR 7 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST
KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE
FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG
AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST
THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE
FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE
RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY
TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER
SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH
ABOUT 8 AM CDT.
THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING
HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON.
FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR
ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS
MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN
PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS
GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT
DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN
THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE
MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF
THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR
THAT AREA.
TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG
AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS.
MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION
MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS
CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT
COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED
THUNDERSTORMS IN THAT AREA AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 319 AM CDT TUE APR 7 2015
AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST
WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY
NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS
THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY
AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT
EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE
POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE
OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE
REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING
DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF
THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN
ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE
DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY
CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO
WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD
ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS
FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING
SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF
THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF
SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING.
A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS
HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS
SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO
DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE
MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR
DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY
AFTERNOON.
ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE
INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS
THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH
PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS
FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO
THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND
WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY
NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST
UNITED STATES.
AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER
70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE
THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO
RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER
50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED
BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS
THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S
EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND
WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE
AROUND 70 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1225 AM CDT TUE APR 7 2015
A WEAK COLD FRONT WILL MOVE THROUGH THE DODGE CITY AND GARDEN CITY
TERMINALS BY THE BEGINNING OF THIS TAF PERIOD. WINDS WILL
INITIALLY BE FROM THE NORTHEAST BEFORE GRADUALLY SHIFTING TO THE
NORTH LATER TONIGHT. WE EXPECT TO SEE CEILINGS AND VISIBILITIES
DROPPING INTO THE IFR TO OCCASIONALLY LIFR CATEGORY FOR A PERIOD
OF TIME BEHIND THE FRONT THROUGH THE EARLY MORNING HOURS. CONDITIONS
SHOULD IMPROVE TO VFR SHORTLY AFTER SUNRISE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 49 84 46 / 0 10 10 10
GCK 79 46 81 42 / 0 10 10 10
EHA 83 47 81 43 / 0 10 0 10
LBL 85 46 85 44 / 0 10 0 0
HYS 70 46 69 46 / 10 20 20 20
P28 85 55 88 53 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR
KSZ045-046-061>065-075>079.
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ061>063-074>078-080-081-084>090.
&&
$$
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS WICHITA KS
334 AM CDT TUE APR 7 2015
.SYNOPSIS...
ISSUED AT 334 AM CDT TUE APR 7 2015
IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING
NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE
PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST-
CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM
THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH
WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING
THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY
ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION
FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN
QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES
LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF
ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE
AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT
THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD
DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR
ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH
AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT
DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE
TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS
BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL
BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW
LEVEL SHEAR.
SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED
AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE
CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM.
THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO
THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS.
THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN
QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE
THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO
DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT
OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED
AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE
CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT
RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT
DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED
AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR
PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM
CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT
SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW
LEVEL MOISTURE.
STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135.
THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER
WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY
SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU
MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP
AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 334 AM CDT TUE APR 7 2015
HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI
ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN
ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A
SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE
PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST
AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR
SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR
MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE
THE BEST CHANCES AT SHOWERS AND STORMS.
LAWSON
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1127 PM CDT MON APR 6 2015
CLEAR SKIES HAVE RETURNED TO THE AREA THIS EVENING...HOWEVER LOW
CIGS WITH VISIBILITIES IN THE 3-5 RANGE ARE ANTICIPATED AFTER
08-10Z ACROSS BOTH CENTRAL KANSAS AND SOUTHEAST KANSAS. IFR/LIFR
CIGS CONTINUE TO EXPAND NORTH OF THE STATIONARY FRONT AND ARE
EXPECTED TO IMPACT THE KRSL AND KSLN AREAS FROM 08-10Z THROUGH AT
LEAST 15Z BEFORE AN INCREASING WESTERLY COMPONENT ADVECTS DRIER
AIR ACROSS THE AREA. FURTHER SOUTH AND EAST...MID AND UPPER 60
DEWPOINTS HAVE RESULTED IN NARROW T/TD SPREADS AND AREAS OF FOG
AND LOW CIGS ARE EXPECTED TO REDEVELOP LATE TONIGHT/EARLY TUE.
&&
.FIRE WEATHER...
ISSUED AT 310 PM CDT MON APR 6 2015
THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE
LOOKS TO BE THURSDAY.
EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE
IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO
STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND
NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON
HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE.
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 83 64 84 55 / 10 10 30 30
HUTCHINSON 80 56 80 51 / 0 10 30 20
NEWTON 83 58 81 53 / 10 10 30 30
ELDORADO 84 65 82 59 / 10 20 30 40
WINFIELD-KWLD 85 65 83 60 / 10 10 30 30
RUSSELL 71 48 70 47 / 10 10 20 20
GREAT BEND 75 50 74 47 / 10 10 20 10
SALINA 75 52 73 50 / 10 10 30 30
MCPHERSON 79 55 77 50 / 10 10 30 30
COFFEYVILLE 83 65 81 65 / 10 20 30 40
CHANUTE 83 65 80 64 / 10 30 30 50
IOLA 83 64 79 63 / 10 30 30 50
PARSONS-KPPF 83 65 81 64 / 10 20 30 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
844 PM EDT Wed Apr 8 2015
...Mesoscale Forecast Update...
Issued at 830 PM EDT Wed Apr 8 2015
Strong to marginally severe convection across southern Indiana and
much of central Kentucky is now pushing into the Bluegrass region.
One renegade supercell near Owensboro weakened rapidly as it pushed
eastward within the last hour, suggesting that our environment has
been worked over, and observed temperatures are now in the upper 60s
across most of the area. Warmer temps in south central Kentucky, but
the environment is capped and the dynamical forcing aloft is also
lacking.
Will cut back on POPs as these storms exit the Bluegrass over the
next hour or so, and work on canceling the Tornado Watch. The Flash
Flood Watch is in effect and will be left in place, even though the
flood threat won`t ramp up again until we get the next round of
convection in sometime Thursday.
.SHORT TERM (Now through Thursday Night)...
Issued at 308 PM EDT Wed Apr 8 2015
...More Strong Storms Possible This Evening and Tomorrow...
Multiple boundaries have set up across the region this afternoon.
SPC mesoanalysis shows all the CIN from earlier in the day has
eroded and we have become moderately unstable with 2500-3500 J/kg CAPE.
A Severe Thunderstorm Watch has been issued for southern Indiana for
this afternoon and early evening. However, given the multiple
boundaries and possibility for strong storms elsewhere around the
forecast area, extensions to the Watch are not out of the question
this afternoon. Large hail and damaging winds will be the main
threats this afternoon, though a tornado or two cannot be ruled out
completely. The other concern for tonight will be the possibility of
training thunderstorms, particularly across southern IN and north
central KY. The latest runs of the HRRR have been suggesting this.
Given that flash flood values are under an inch an hour and storms
may train in this area, have gone ahead and issued a Flash Flood
Watch starting late this afternoon and continuing through tomorrow
night.
There should be a relative lull in the storms for much of the
overnight period as any storms that develop this afternoon will move
out late this evening. Think another complex associated with a weak
upper level wave will move in early tomorrow morning and continue
through the morning hours. Some small hail and gusty winds will be
possible with these storms.
There should be at least a short break in storm coverage tomorrow
afternoon ahead of the more significant chance for severe weather
along and ahead of the cold front tomorrow night. Moisture will pool
ahead of the front with strong southerly winds through the afternoon
tomorrow. Forcing will come from the upper level trough moving in
and an upper level jet. Shear will increase and hodographs exhibit
favorable clockwise curving tomorrow night. A broken line of showers
and thunderstorms looks to develop to our west congeal into a line
as it moves into the forecast area tomorrow evening. Damaging winds
will be the the main threat with the squall line, with a few
embedded tornadoes possible. If any cells do develop ahead of the
main line hail could be a threat as well.
Due to the repeated areas of convection moving across the region,
have kept the Flash Flood Watch in place through tomorrow night.
Repeated rains will only exacerbate or renew flooding problems.
.LONG TERM (Friday through Wednesday)...
Issued at 241 PM EDT Wed Apr 8 2015
Not much has changed in the thinking for the long term period. Due
to the ongoing storms an updated discussion will not be issued this
afternoon. The previous discussion is below.
Previous discussion
-------------------
Cold front should pass through the area during the pre-dawn hours
Friday in our west then sweep across the rest of central Kentucky
during the early morning hours. Westerly flow will bring in a drier
and quieter pattern Friday night.
Plan on a pleasant, sunny and seasonable Saturday with high pressure
over the lower Ohio Valley. Sunday will start off in similar fashion
but as the high quickly moves to the east, southerly return flow
will begin to push another slug of warm, moist air to the region.
Shower chances return Sunday night through Monday as a trough digs
across the central Plains. High-end chance to likely POPs look
reasonable early next week with near normal temperatures.
&&
.AVIATION (00Z TAF Update)...
Updated at 645 PM EDT Wed Apr 8 2015
Scattered thunderstorms will continue across north central KY for
the next few hours. These storms will continue to affect SDF and LEX
off an on. Storms are expected to diminish by 03Z or so with drier
conditions for much of the rest of the night. A few showers may
develop around BWG over the next few hours, but storms are not
expected at this time.
The next complex of storms will begin to move in around 11-12Z.
These will affect all TAF sites tomorrow morning, moving out early
afternoon. Winds will increase tomorrow afternoon as a cold front
begins to approach from the west. South-southwesterly winds will be
sustained up to around 15 knots with gusts of 20-25 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH through late Thursday night FOR KYZ023>025-
028>043-045>049-053>057-066-067.
IN...FLASH FLOOD WATCH through late Thursday night FOR INZ076>079-083-
084-089>092.
&&
$$
Mesoscale......RAS
Short Term.....EER
Long Term......BJS
Aviation.......EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
749 PM EDT WED APR 8 2015
.UPDATE...
ISSUED AT 750 PM EDT WED APR 8 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS
AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN
KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY
RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S
AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH
AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH
THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS
OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING
THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME
TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER
05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE
CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 455 PM EDT WED APR 8 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY
WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS.
SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER
TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS
UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES
MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF
CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN
THE SMALL SCALE FEATURES AT PLAY.
IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS
EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING
CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG
QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY
WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL
CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST
HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING
THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE
NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN
THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN
CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT
CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR
SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z.
HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE
THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES.
THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY
MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH
APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES
FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 521 PM EDT WED APR 8 2015
A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE
PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF
THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING
THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL
THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY.
AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A
WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY
OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD
SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE
MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN
FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE
LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES
ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY
NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS
LONG RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 750 PM EDT WED APR 8 2015
AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH NORTHERN
KENTUCKY THIS EVENING. EXPECT A FEW INSTANCES OF MVFR
CONDITIONS...MAINLY IN AND AROUND THE HEAVY THUNDERSTORMS. THIS
ACTIVITY WILL MOVE OFF TOP THE EAST BY 05Z AND SKIES WILL BEGIN TO
CLEAR A BIT AS CLOUD COVER ASSOCIATED WITH THE ACTIVITY
DISSIPATES. WITH THIS...MAY SEE A FEW AREAS OF FOG LATE TONIGHT
AND HAVE PUT THIS INTO THE TAF SITES. CONDITIONS SHOULD BEGIN TO
IMPROVE AFTER DAWN BEFORE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS DEVELOP LATE THURSDAY AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ044-050>052-
104.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JVM/GREIF
LONG TERM...HAL
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
230 PM EDT TUE APR 7 2015
.UPDATE...
ISSUED AT 1135 AM EDT TUE APR 7 2015
THUNDERSTORM COMPLEX WHICH RESULTED IN A FEW FLOODING REPORTS IN
OUR SOUTHERN COUNTIES IS EXITING INTO TN AND VA. OTHER
THUNDERSTORMS IN THE LMK AREA WERE HEADING TOWARD OUR NORTHERN
COUNTIES...BUT WERE WEAKENING. HAVE ADJUSTED NEAR TERM POPS FOR
THE OBSERVED RADAR TRENDS. WITH A MOIST AIR MASS...WARM AIR
ADVECTION...A FRONTAL BOUNDARY JUST TO OUR NORTH...NO SIGNIFICANT
CAP...AND WEAK IMPULSES PASSING THROUGH...
REDEVELOPMENT/INTENSIFICATION WILL BE A POSSIBILITY AS SOME
LIMITED DESTABILIZATION OCCURS THIS AFTERNOON. CONFIDENCE IN
TIMING AND LOCATION IS LOW. HAVE LEANED TOWARD THE HRRR SOLUTION
THIS AFTERNOON INTO TONIGHT...BUT KEPT THE FORECAST FAIRLY
GENERALIZED.
UPDATE ISSUED AT 800 AM EDT TUE APR 7 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS
WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING
THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST
OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 7 2015
06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE
BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY.
THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS
SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE
STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A
RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL
CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM
FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND
SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT...
MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60
DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER
CONDITIONS IN THE FAR SOUTHWEST. DEW POINTS...MEANWHILE...HAVE
COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS
PAST WEEKEND/S DRYNESS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO
VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN
FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY
DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING
CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY
WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND
HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID
LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL
NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE
NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER
RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID
PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS
EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED
FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM
ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF
CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS
AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL
UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP
AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY
TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH
AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE
RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND
MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL
STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT
BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO.
USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE
WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND
THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR
TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET
VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE APR 7 2015
MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN
ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE
EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER
THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING
LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO
CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY
AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS
THE OHIO RIVER VALLEY DURING THIS TIME.
AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A
STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH
WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA.
THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY
ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW
WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED
SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY
THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A
STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH
FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE
BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY
AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE
MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN
21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE
ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS
THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE
NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT
FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY
AFTERNOON.
EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH
OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE
LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE
SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT
NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO
FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE
ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS
THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT
TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF
THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT
RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 230 PM EDT TUE APR 7 2015
SHOWERS AND A FEW RUMBLES OF THUNDER WERE ONGOING OVER PORTIONS OF
THE FORECAST AREA AT THE START OF THE PERIOD...ESPECIALLY NORTH OF
A LINE FROM MOUNT STERLING TO PAINTSVILLE. WILL LOOK FOR MOST OF
THE ACTIVITY TO WEAKEN AND MOVE OUT TO THE EAST DURING THE COURSE
OF THE AFTERNOON. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE DURING THE FORECAST PERIOD. HOWEVER...THERE IS LOW
CONFIDENCE AS TO WHEN/WHERE THEY MAY OCCUR. FOR THAT REASON...HAVE
ONLY USED VCTS AFTER THIS AFTERNOON. IN TERMS OF CONDITIONS...MVFR
COULD OCCUR WITH THE PRECIP. OUTSIDE OF THIS...WILL LOOK FOR
LARGELY VFR. THE TAFS ARE WRITTEN IN A GENERALIZED FASHION DUE TO
LOW FORECAST CONFIDENCE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
120 PM EDT Tue Apr 7 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1149 AM EDT Tue Apr 7 2015
The complex of showers and thunderstorms will continue to push east
along the I-64 corridor for the next hour or two. They are looking
less organized but will still be capable of frequent cloud to ground
lightning and brief heavy rainfall.
Focus is now shifting to the west where the previous supercell has
now evolved into a growing linear segment crossing the Mississippi
River near St. Louis. This feature is expected to continue ESE or SE
toward our region through the early afternoon, growing as it does
so. Already seeing good destabilization across west central KY where
some clearing has occurred, and do expect a 1500 - 2500 J/KG
instability axis to setup along and west of I-65 during peak
heating. Some of the southern Indiana counties where this morning`s
complex passed may struggle to get as unstable. Will also note that
0-6 km bulk shear should range between 30-40 knots, sufficient for
continued organization. Forecast sounding are quite impressive if
they verify and would suggest a severe wind and hail threat with the
strongest storms. In collaboration with the Storm Prediction Center,
mention of an upgrade to a slight risk is a possibility across
western portions of our CWA this afternoon. Right now the best
timing for the CWA looks to be between 3 PM EDT and 9 PM EDT.
Do want to mention that another round of heavy rain will accompany
the potential severe threat with this next round of convection.
Depending on where heaviest rain falls, more hydro products may be
needed.
Previous Update...
Issued at 919 AM EDT Tue Apr 7 2015
Storms will wind down along the I-64 corridor through the late
morning hours. However, will have to keep an eye on the stronger
cluster currently over southern Indiana as it moves ESE toward the
Kentucky Bluegrass region. Very intense rainfall has left 2 to 3
inches in a short amount of time across small portions of southern
Indiana and will keep the Flash Flood Warning going across
Orange/Washington counties for the time being. Have upped pops and
QPF to account for this cluster. Hail will also be possible with
this storm.
Focus will then shift to this afternoon and evening as another round
of storms will be possible. Looking upstream, an impressive
supercell is tracking ESE along I-70 and the warm front toward St.
Louis. This feature is expected to turn more SE along the
instability gradient through the late morning and early afternoon,
and grow into a more linear complex. Do expect to get some partial
clearing which will aid an already destabilizing atmosphere. SREF
probabilities of greater than 1000 J/KG of CAPE this afternoon are
likely along and west of I-65. 0-6 km shear values between 30 and 40
knots this afternoon would also support organization. Will have to
watch how things progress through the late morning as there is some
concern for strong to severe storms this afternoon and evening.
The 06z NAM and HRRR are handling the current situation pretty well.
However the NAM is a bit too far north and a couple hours slow. Did
the afternoon forecast based off this solution with adjustments for
timing placement. Adjusted QPF upward as well in anticipation of the
afternoon storms.
.SHORT TERM (Now through Wednesday)...
Issued at 257 AM EDT Tue Apr 7 2015
The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good
handle on an area of showers and embedded thunderstorms moving from
southeast Illinois into the lower and middle Ohio Valley at 07Z
this morning. The storms are ahead of an upper level disturbance
coming in from the lower and middle Mississippi Valley. This
convective complex will continue to spread eastward this morning
along and a few counties either side of the I-64 corridor. Though
the showers and storms will mostly be garden variety, a few gusts of
wind or instances of small hail in the strongest cores can`t be
entirely ruled out.
The morning showers and storms will have moved off to the east by
early afternoon. This afternoon another weak upper wave will come
in from the west. Though some stabilization will occur over
southern Indiana and northern Kentucky from the morning rain,
additional scattered shower and thunderstorm development will be
possible, albeit with less coverage than what we see this morning.
Again, a few strong storms will be possible.
With plenty of moisture available, locally heavy downpours will be
possible with the thunderstorms. The cells should be progressive,
but there will be some training this morning in southern Indiana
and north central Kentucky.
Decided to drop max temps a few degrees in the north where more rain
and clouds will prevail through the morning hours, but still have
70s everywhere for highs this afternoon.
After a lull this evening, more shower and thunderstorm development
will be possible late tonight as the next weak upper wave comes in
from the west after midnight. Low temperatures will be in the lower
and middle 60s.
The relatively low confidence forecast today and tonight becomes
even lower on Wednesday. We will remain in the same warm, juicy air
mass as today, south of a stationary surface front from Illinois to
Ohio. The late night showers/storms tonight will likely persist
into Wednesday morning, with redevelopment possible Wednesday
afternoon especially near any leftover convective boundaries from
the morning activity. Highs should be in the middle and upper
70s...maybe an 80 degree reading if we can get enough sunshine in
the afternoon.
.LONG TERM (Wednesday Night through Monday)...
Issued at 235 AM EDT Tue Apr 7 2015
The focus in the long term period is on thunderstorm chances/timing
Wednesday night through Friday.
The upper level pattern Wednesday night is expected to feature a
digging trough from the Rockies into the central Plains with
downstream ridging extending from the Gulf Coast through the
southern Great Lakes region. At the surface, a warm and moist air
mass characterized by dewpoints in the 60s will be in place thanks
to a developing surface low to our west. Stronger southerly flow
should make for a mild night with lows only falling into the mid
60s.
The focus for thunderstorm initiation Wednesday night is favored to
our west where the strengthening low-level jet impinges on an
east-west boundary across Illinois. These storms could then take an
east/southeast track across portions of the area. Strength/severity
a bit more uncertain as elevated instability wanes considerably
and effective shear is not as impressive but a few elevated stronger
storms would be possible. Kept POPs in the 30-50 percent range,
tapered highest to lowest from southern Indiana to southern Kentucky
respectively.
The main upper level trough will advance eastward Thursday as the
surface low deepens/lifts to Wisconsin by Thursday night. 07.00z
guidance remained overall similar to earlier runs in its
progression, bringing the cold front through the local area late
Thursday night into Friday morning. Scattered showers and
thunderstorms are possible ahead of the main system though coverage
isn`t expected to be very high. Decaying strong thunderstorms look
to be approaching our western borders during the late evening, and
if enough elevated instability remains present, a marginal wind
threat exists. Overall, the system looks fairly progressive,
limiting the training heavy rainfall threat as well.
Ahead of the front, a very warm air mass will be in place. Depending
on how cloud cover fares, we`ll be approaching 80 degrees in most
spots Thursday. A mild night would then set up with lows in the mid
60s to near 70 degrees.
Friday looks to be our transition day as the front sweeps across the
area. Will keep chance POPs in the morning to early afternoon hours,
especially east of I-65 before clearing conditions work in for the
evening. Seasonable, pleasant and mostly sunny conditions thanks to
surface high pressure expected Saturday into the first part of
Sunday. A model consensus approach gives highs in the mid to upper
60s Saturday and upper 60s to low 70s Sunday.
Increasing moisture and southerly return flow sets up Sunday night
into early next week as the surface high moves to our east. A slow
ramp up in POPs, still chance, will be advertised as deterministic
models show another system lifting through the central Plains to
lower Great Lakes. Seasonable to above seasonable temperatures look
reasonable at this time.
&&
.AVIATION (18Z TAF Update)...
Updated at 120 PM EDT Tue Apr 7 2015
We`re in a relative lull with convection with only some storms
hanging around LEX for another hour or two. Warm sector has become
firmly established over the area and should see mostly VFR
conditions as skies partially clear through much of the afternoon.
Expect a steady south wind around 10 mph with a few higher gusts
possible.
Focus is upstream on the next convective complex set to move into
the TAF sites from late afternoon through evening. Best timing at
SDF is expected between 5 and 10 PM EDT where visibilities could
drop into the IFR range in heavier thunderstorms. Stronger wind
gusts and some hail will also be possible with the strongest storms.
LEX/BWG should see weaker convection and a couple hours later than
at SDF. There should be another relative lull overnight where VFR
conditions are expected to prevail. More convection possible
again Wednesday morning. Confidence is low beyond this evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....13
Long Term......ZT
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1150 AM EDT Tue Apr 7 2015
...Forecast Update...
Issued at 1149 AM EDT Tue Apr 7 2015
The complex of showers and thunderstorms will continue to push east
along the I-64 corridor for the next hour or two. They are looking
less organized but will still be capable of frequent cloud to ground
lightning and brief heavy rainfall.
Focus is now shifting to the west where the previous supercell has
now evolved into a growing linear segment crossing the Mississippi
River near St. Louis. This feature is expected to continue ESE or SE
toward our region through the early afternoon, growing as it does
so. Already seeing good destabilization across west central KY where
some clearing has occurred, and do expect a 1500 - 2500 J/KG
instability axis to setup along and west of I-65 during peak
heating. Some of the southern Indiana counties where this morning`s
complex passed may struggle to get as unstable. Will also note that
0-6 km bulk shear should range between 30-40 knots, sufficient for
continued organization. Forecast sounding are quite impressive if
they verify and would suggest a severe wind and hail threat with the
strongest storms. In collaboration with the Storm Prediction Center,
mention of an upgrade to a slight risk is a possibility across
western portions of our CWA this afternoon. Right now the best
timing for the CWA looks to be between 3 PM EDT and 9 PM EDT.
Do want to mention that another round of heavy rain will accompany
the potential severe threat with this next round of convection.
Depending on where heaviest rain falls, more hydro products may be
needed.
Previous Update...
Issued at 919 AM EDT Tue Apr 7 2015
Storms will wind down along the I-64 corridor through the late
morning hours. However, will have to keep an eye on the stronger
cluster currently over southern Indiana as it moves ESE toward the
Kentucky Bluegrass region. Very intense rainfall has left 2 to 3
inches in a short amount of time across small portions of southern
Indiana and will keep the Flash Flood Warning going across
Orange/Washington counties for the time being. Have upped pops and
QPF to account for this cluster. Hail will also be possible with
this storm.
Focus will then shift to this afternoon and evening as another round
of storms will be possible. Looking upstream, an impressive
supercell is tracking ESE along I-70 and the warm front toward St.
Louis. This feature is expected to turn more SE along the
instability gradient through the late morning and early afternoon,
and grow into a more linear complex. Do expect to get some partial
clearing which will aid an already destabilizing atmosphere. SREF
probabilities of greater than 1000 J/KG of CAPE this afternoon are
likely along and west of I-65. 0-6 km shear values between 30 and 40
knots this afternoon would also support organization. Will have to
watch how things progress through the late morning as there is some
concern for strong to severe storms this afternoon and evening.
The 06z NAM and HRRR are handling the current situation pretty well.
However the NAM is a bit too far north and a couple hours slow. Did
the afternoon forecast based off this solution with adjustments for
timing placement. Adjusted QPF upward as well in anticipation of the
afternoon storms.
.SHORT TERM (Now through Wednesday)...
Issued at 257 AM EDT Tue Apr 7 2015
The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good
handle on an area of showers and embedded thunderstorms moving from
southeast Illinois into the lower and middle Ohio Valley at 07Z
this morning. The storms are ahead of an upper level disturbance
coming in from the lower and middle Mississippi Valley. This
convective complex will continue to spread eastward this morning
along and a few counties either side of the I-64 corridor. Though
the showers and storms will mostly be garden variety, a few gusts of
wind or instances of small hail in the strongest cores can`t be
entirely ruled out.
The morning showers and storms will have moved off to the east by
early afternoon. This afternoon another weak upper wave will come
in from the west. Though some stabilization will occur over
southern Indiana and northern Kentucky from the morning rain,
additional scattered shower and thunderstorm development will be
possible, albeit with less coverage than what we see this morning.
Again, a few strong storms will be possible.
With plenty of moisture available, locally heavy downpours will be
possible with the thunderstorms. The cells should be progressive,
but there will be some training this morning in southern Indiana
and north central Kentucky.
Decided to drop max temps a few degrees in the north where more rain
and clouds will prevail through the morning hours, but still have
70s everywhere for highs this afternoon.
After a lull this evening, more shower and thunderstorm development
will be possible late tonight as the next weak upper wave comes in
from the west after midnight. Low temperatures will be in the lower
and middle 60s.
The relatively low confidence forecast today and tonight becomes
even lower on Wednesday. We will remain in the same warm, juicy air
mass as today, south of a stationary surface front from Illinois to
Ohio. The late night showers/storms tonight will likely persist
into Wednesday morning, with redevelopment possible Wednesday
afternoon especially near any leftover convective boundaries from
the morning activity. Highs should be in the middle and upper
70s...maybe an 80 degree reading if we can get enough sunshine in
the afternoon.
.LONG TERM (Wednesday Night through Monday)...
Issued at 235 AM EDT Tue Apr 7 2015
The focus in the long term period is on thunderstorm chances/timing
Wednesday night through Friday.
The upper level pattern Wednesday night is expected to feature a
digging trough from the Rockies into the central Plains with
downstream ridging extending from the Gulf Coast through the
southern Great Lakes region. At the surface, a warm and moist air
mass characterized by dewpoints in the 60s will be in place thanks
to a developing surface low to our west. Stronger southerly flow
should make for a mild night with lows only falling into the mid
60s.
The focus for thunderstorm initiation Wednesday night is favored to
our west where the strengthening low-level jet impinges on an
east-west boundary across Illinois. These storms could then take an
east/southeast track across portions of the area. Strength/severity
a bit more uncertain as elevated instability wanes considerably
and effective shear is not as impressive but a few elevated stronger
storms would be possible. Kept POPs in the 30-50 percent range,
tapered highest to lowest from southern Indiana to southern Kentucky
respectively.
The main upper level trough will advance eastward Thursday as the
surface low deepens/lifts to Wisconsin by Thursday night. 07.00z
guidance remained overall similar to earlier runs in its
progression, bringing the cold front through the local area late
Thursday night into Friday morning. Scattered showers and
thunderstorms are possible ahead of the main system though coverage
isn`t expected to be very high. Decaying strong thunderstorms look
to be approaching our western borders during the late evening, and
if enough elevated instability remains present, a marginal wind
threat exists. Overall, the system looks fairly progressive,
limiting the training heavy rainfall threat as well.
Ahead of the front, a very warm air mass will be in place. Depending
on how cloud cover fares, we`ll be approaching 80 degrees in most
spots Thursday. A mild night would then set up with lows in the mid
60s to near 70 degrees.
Friday looks to be our transition day as the front sweeps across the
area. Will keep chance POPs in the morning to early afternoon hours,
especially east of I-65 before clearing conditions work in for the
evening. Seasonable, pleasant and mostly sunny conditions thanks to
surface high pressure expected Saturday into the first part of
Sunday. A model consensus approach gives highs in the mid to upper
60s Saturday and upper 60s to low 70s Sunday.
Increasing moisture and southerly return flow sets up Sunday night
into early next week as the surface high moves to our east. A slow
ramp up in POPs, still chance, will be advertised as deterministic
models show another system lifting through the central Plains to
lower Great Lakes. Seasonable to above seasonable temperatures look
reasonable at this time.
&&
.AVIATION (12Z TAF Update)...
Updated at 636 AM EDT Tue Apr 7 2015
Showers should be common through the morning hours, especially at
LEX and SDF, with some embedded thunder as well. Ceilings will be
highly variable, but should prevail MVFR below fuel mins. Expect
drier conditions this afternoon and tonight (though scattered
showers and storms will still be possible). Ceilings should
gradually improve today as the wave that is sparking this morning`s
convection moves off to the east.
BWG could see a few wind gusts into the teens this afternoon outside
of convection.
Another wave of convection may come in from the northwest late
tonight into Wednesday morning, though forecast confidence is not
high that far out in this weather regime.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....13
Long Term......ZT
Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
1135 AM EDT TUE APR 7 2015
.UPDATE...
ISSUED AT 1135 AM EDT TUE APR 7 2015
THUNDERSTORM COMPLEX WHICH RESULTED IN A FEW FLOODING REPORTS IN
OUR SOUTHERN COUNTIES IS EXITING IN TN AND VA. OTHER THUNDERSTORMS
IN THE LMK AREA WERE HEADING TOWARD OUR NORTHERN COUNTIES...BUT
WERE WEAKENING. HAVE ADJUSTED NEAR TERM POPS FOR THE OBSERVED
RADAR TRENDS. WITH A MOIST AIR MASS...WARM AIR ADVECTION...A
FRONTAL BOUNDARY JUST TO OUR NORTH...NO SIGNIFICANT CAP...AND WEAK
IMPULSES PASSING THROUGH...REDEVELOPMENT/INTENSIFICATION WILL BE A
POSSIBILITY AS SOME LIMITED DESTABILIZATION OCCURS THIS AFTERNOON.
CONFIDENCE IN TIMING AND LOCATION IS LOW. HAVE LEANED TOWARD THE
HRRR SOLUTION THIS AFTERNOON INTO TONIGHT...BUT KEPT THE FORECAST
FAIRLY GENERALIZED.
UPDATE ISSUED AT 800 AM EDT TUE APR 7 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS
WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING
THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST
OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 7 2015
06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE
BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY.
THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS
SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE
STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A
RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL
CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM
FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND
SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT...
MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60
DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER
CONDITIONS IN THE FAR SOUTHWEST. DEW POINTS...MEANWHILE...HAVE
COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS
PAST WEEKEND/S DRYNESS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO
VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN
FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY
DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING
CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY
WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND
HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID
LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL
NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE
NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER
RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID
PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS
EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED
FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM
ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF
CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS
AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL
UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP
AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY
TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH
AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE
RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND
MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL
STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT
BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO.
USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE
WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND
THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR
TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET
VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE APR 7 2015
MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN
ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE
EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER
THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING
LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO
CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY
AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS
THE OHIO RIVER VALLEY DURING THIS TIME.
AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A
STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH
WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA.
THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY
ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW
WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED
SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY
THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A
STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH
FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE
BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY
AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE
MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN
21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE
ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS
THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE
NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT
FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY
AFTERNOON.
EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH
OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE
LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE
SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT
NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO
FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE
ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS
THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT
TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF
THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT
RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 815 AM EDT TUE APR 7 2015
THE SHOWERS AND STORMS MOVED INTO THE AREA ON TRACK WITH THE
EARLIER FORECAST WITH MVFR TO IFR CIGS. THESE WILL BE THE RULE
FOR MOST OF THE AREA THROUGH THE TAF PERIOD EVEN ONCE THIS
INITIAL PASSES THROUGH BY MID MORNING. ANOTHER IMPULSE IS EXPECTED
THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE
HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL
IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL
GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT FOR HIGHER
GUSTS IN STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
920 AM EDT Tue Apr 7 2015
...Forecast Update...
Issued at 919 AM EDT Tue Apr 7 2015
Storms will wind down along the I-64 corridor through the late
morning hours. However, will have to keep an eye on the stronger
cluster currently over southern Indiana as it moves ESE toward the
Kentucky Bluegrass region. Very intense rainfall has left 2 to 3
inches in a short amount of time across small portions of southern
Indiana and will keep the Flash Flood Warning going across
Orange/Washington counties for the time being. Have upped pops and
QPF to account for this cluster. Hail will also be possible with
this storm.
Focus will then shift to this afternoon and evening as another round
of storms will be possible. Looking upstream, an impressive
supercell is tracking ESE along I-70 and the warm front toward St.
Louis. This feature is expected to turn more SE along the
instability gradient through the late morning and early afternoon,
and grow into a more linear complex. Do expect to get some partial
clearing which will aid an already destabilizing atmosphere. SREF
probabilities of greater than 1000 J/KG of CAPE this afternoon are
likely along and west of I-65. 0-6 km shear values between 30 and 40
knots this afternoon would also support organization. Will have to
watch how things progress through the late morning as there is some
concern for strong to severe storms this afternoon and evening.
The 06z NAM and HRRR are handling the current situation pretty well.
However the NAM is a bit too far north and a couple hours slow. Did
the afternoon forecast based off this solution with adjustments for
timing placement. Adjusted QPF upward as well in anticipation of the
afternoon storms.
.SHORT TERM (Now through Wednesday)...
Issued at 257 AM EDT Tue Apr 7 2015
The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good
handle on an area of showers and embedded thunderstorms moving from
southeast Illinois into the lower and middle Ohio Valley at 07Z
this morning. The storms are ahead of an upper level disturbance
coming in from the lower and middle Mississippi Valley. This
convective complex will continue to spread eastward this morning
along and a few counties either side of the I-64 corridor. Though
the showers and storms will mostly be garden variety, a few gusts of
wind or instances of small hail in the strongest cores can`t be
entirely ruled out.
The morning showers and storms will have moved off to the east by
early afternoon. This afternoon another weak upper wave will come
in from the west. Though some stabilization will occur over
southern Indiana and northern Kentucky from the morning rain,
additional scattered shower and thunderstorm development will be
possible, albeit with less coverage than what we see this morning.
Again, a few strong storms will be possible.
With plenty of moisture available, locally heavy downpours will be
possible with the thunderstorms. The cells should be progressive,
but there will be some training this morning in southern Indiana
and north central Kentucky.
Decided to drop max temps a few degrees in the north where more rain
and clouds will prevail through the morning hours, but still have
70s everywhere for highs this afternoon.
After a lull this evening, more shower and thunderstorm development
will be possible late tonight as the next weak upper wave comes in
from the west after midnight. Low temperatures will be in the lower
and middle 60s.
The relatively low confidence forecast today and tonight becomes
even lower on Wednesday. We will remain in the same warm, juicy air
mass as today, south of a stationary surface front from Illinois to
Ohio. The late night showers/storms tonight will likely persist
into Wednesday morning, with redevelopment possible Wednesday
afternoon especially near any leftover convective boundaries from
the morning activity. Highs should be in the middle and upper
70s...maybe an 80 degree reading if we can get enough sunshine in
the afternoon.
.LONG TERM (Wednesday Night through Monday)...
Issued at 235 AM EDT Tue Apr 7 2015
The focus in the long term period is on thunderstorm chances/timing
Wednesday night through Friday.
The upper level pattern Wednesday night is expected to feature a
digging trough from the Rockies into the central Plains with
downstream ridging extending from the Gulf Coast through the
southern Great Lakes region. At the surface, a warm and moist air
mass characterized by dewpoints in the 60s will be in place thanks
to a developing surface low to our west. Stronger southerly flow
should make for a mild night with lows only falling into the mid
60s.
The focus for thunderstorm initiation Wednesday night is favored to
our west where the strengthening low-level jet impinges on an
east-west boundary across Illinois. These storms could then take an
east/southeast track across portions of the area. Strength/severity
a bit more uncertain as elevated instability wanes considerably
and effective shear is not as impressive but a few elevated stronger
storms would be possible. Kept POPs in the 30-50 percent range,
tapered highest to lowest from southern Indiana to southern Kentucky
respectively.
The main upper level trough will advance eastward Thursday as the
surface low deepens/lifts to Wisconsin by Thursday night. 07.00z
guidance remained overall similar to earlier runs in its
progression, bringing the cold front through the local area late
Thursday night into Friday morning. Scattered showers and
thunderstorms are possible ahead of the main system though coverage
isn`t expected to be very high. Decaying strong thunderstorms look
to be approaching our western borders during the late evening, and
if enough elevated instability remains present, a marginal wind
threat exists. Overall, the system looks fairly progressive,
limiting the training heavy rainfall threat as well.
Ahead of the front, a very warm air mass will be in place. Depending
on how cloud cover fares, we`ll be approaching 80 degrees in most
spots Thursday. A mild night would then set up with lows in the mid
60s to near 70 degrees.
Friday looks to be our transition day as the front sweeps across the
area. Will keep chance POPs in the morning to early afternoon hours,
especially east of I-65 before clearing conditions work in for the
evening. Seasonable, pleasant and mostly sunny conditions thanks to
surface high pressure expected Saturday into the first part of
Sunday. A model consensus approach gives highs in the mid to upper
60s Saturday and upper 60s to low 70s Sunday.
Increasing moisture and southerly return flow sets up Sunday night
into early next week as the surface high moves to our east. A slow
ramp up in POPs, still chance, will be advertised as deterministic
models show another system lifting through the central Plains to
lower Great Lakes. Seasonable to above seasonable temperatures look
reasonable at this time.
&&
.AVIATION (12Z TAF Update)...
Updated at 636 AM EDT Tue Apr 7 2015
Showers should be common through the morning hours, especially at
LEX and SDF, with some embedded thunder as well. Ceilings will be
highly variable, but should prevail MVFR below fuel mins. Expect
drier conditions this afternoon and tonight (though scattered
showers and storms will still be possible). Ceilings should
gradually improve today as the wave that is sparking this morning`s
convection moves off to the east.
BWG could see a few wind gusts into the teens this afternoon outside
of convection.
Another wave of convection may come in from the northwest late
tonight into Wednesday morning, though forecast confidence is not
high that far out in this weather regime.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....13
Long Term......ZT
Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
815 AM EDT TUE APR 7 2015
.UPDATE...
ISSUED AT 800 AM EDT TUE APR 7 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS
WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING
THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST
OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 7 2015
06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE
BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY.
THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS
SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE
STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A
RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL
CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM
FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND
SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT...
MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60
DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER
CONDITIONS IN THE FAR SOUTHWEST. DEWPOINTS...MEANWHILE...HAVE
COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS
PAST WEEKEND/S DRYNESS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO
VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN
FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY
DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING
CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY
WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND
HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID
LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL
NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE
NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER
RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID
PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS
EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED
FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM
ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF
CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS
AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL
UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP
AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY
TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH
AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE
RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND
MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL
STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT
BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO.
USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE
WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND
THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR
TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET
VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE APR 7 2015
MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN
ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE
EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER
THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING
LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO
CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY
AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS
THE OHIO RIVER VALLEY DURING THIS TIME.
AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A
STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH
WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA.
THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY
ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW
WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED
SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY
THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A
STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH
FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE
BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY
AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE
MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN
21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE
ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS
THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE
NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT
FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY
AFTERNOON.
EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH
OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE
LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE
SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT
NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO
FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE
ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS
THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT
TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF
THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT
RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 815 AM EDT TUE APR 7 2015
THE SHOWERS AND STORMS MOVED INTO THE AREA ON TRACK WITH THE
EARLIER FORECAST WITH MVFR TO IFR CIGS. THESE WILL BE THE RULE
FOR MOST OF THE AREA THROUGH THE TAF PERIOD EVEN ONCE THIS
INITIAL PASSES THROUGH BY MID MORNING. ANOTHER IMPULSE IS EXPECTED
THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE
HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL
IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL
GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT FOR HIGHER
GUSTS IN STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 AM EDT TUE APR 7 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 7 2015
06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE
BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY.
THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS
SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE
STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A
RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL
CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM
FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND
SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT...
MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60
DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER
CONDITIONS IN THE FAR SOUTHWEST. DEWPOINTS...MEANWHILE...HAVE
COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS
PAST WEEKEND/S DRYNESS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO
VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN
FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY
DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING
CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY
WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND
HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID
LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL
NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE
NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER
RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID
PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS
EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED
FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM
ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF
CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS
AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL
UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP
AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY
TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH
AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE
RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND
MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL
STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT
BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO.
USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE
WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND
THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR
TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET
VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE APR 7 2015
MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN
ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE
EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER
THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING
LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO
CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY
AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS
THE OHIO RIVER VALLEY DURING THIS TIME.
AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A
STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH
WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA.
THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY
ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW
WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED
SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY
THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A
STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH
FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE
BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY
AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE
MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN
21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE
ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS
THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE
NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT
FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY
AFTERNOON.
EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH
OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE
LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE
SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT
NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO
FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE
ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS
THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT
TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF
THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT
RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 210 AM EDT TUE APR 7 2015
THE LATEST HRRR AND NAM12 HOLD OFF ON ANY SIGNIFICANT PCPN MOVING
INTO EAST KENTUCKY UNTIL CLOSER TO 12Z. THIS LINES UP WELL WITH A
CLUSTER OF SHOWERS AND THUNDERSTORMS NOW MOVING THROUGH SOUTHERN
ILLINOIS...INDIANA AND NORTHWEST KENTUCKY. MVFR CIGS WILL BE THE
RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD AS THIS INITIAL
WAVE APPROACHES AND PASSES THROUGH THIS MORNING FOLLOWED BY
ANOTHER POSSIBLE IMPULSE LATER THIS EVENING WITH ADDITIONAL LOW
CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS
WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS.
THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT
5 TO 10 KTS...EXCEPT IN HIGHER GUSTS IN STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
209 AM EDT TUE APR 7 2015
.UPDATE...
ISSUED AT 145 AM EDT TUE APR 7 2015
DID A QUICK UPDATE TO THE GRIDS MAINLY TO SLOW DOWN THE ARRIVAL OF
ANY SIGNIFICANT PCPN UNTIL CLOSER TOWARD DAWN. ALSO UPDATED THE
SKY COVER AND T/TD GRIDS PER THE LATEST SHORTBLEND GUIDANCE...
OBS...AND TRENDS. THESE HAVE BEEN SENT TO THE THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 1051 PM EDT MON APR 6 2015
THE AREA OF SHOWERS THAT AFFECTED SOUTHERN PORTIONS OF THE CWA
HAVE MOVED EAST OF THE REGION THIS HOUR. WSR-88D RADAR SHOWS A
AREA OF SHOWERS ACROSS CENTRAL KY MOVING SOUTH AND EAST...HOWEVER
THIS AREA OF SHOWERS HAS CONTINUED TO WANE OVER THE PAST FEW
HOURS. GIVEN THIS FELT IT JUSTIFIED DROPPING POPS FOR PORTIONS OF
THE NIGHT. ALL EYES THEN TURN TO THE WEST...WHILE A SUBTLE UPPER
LEVEL WAVE MOVES THROUGH THE FLOW AS WE MOVE THROUGH THE NIGHT
INTO EARLY TOMORROW. WHILE IT SHOULD BE SAID THAT THE GUIDANCE
CONTINUES TO STRUGGLE TONIGHT...THE HRRR HAS COME BACK TO
PROGRESSING AN AREA OF PRECIP ALONG THE WESTERN CWA BORDER TOWARD
THE DAWN HOURS TUESDAY. DID STICK CLOSE TO PREVIOUS FORECAST FOR
THAT PERIOD...GIVEN CONTINUED UNCERTAINTY ON NEXT AREA OF PRECIP
AND STILL LOOKED REASONABLE BASED ON LATEST MESO MODEL GUIDANCE.
ALSO UPDATED GRIDS TO MATCH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 832 PM EDT MON APR 6 2015
WSR-88D CONTINUES TO SHOW AN AREA OF SHOWERS MOVING EAST ACROSS
SOUTHEAST PORTIONS OF THE CWA THIS EVENING. HEAVIER SHOWERS HAVE
GENERALLY BEEN ALONG AND NEAR THE TN/VA BORDER THIS AFTERNOON AND
EVENING. OTHERWISE MOST AREAS ARE CONTINUING TO SEE A PASSING
LIGHT SHOWER FROM TIME TO TIME. EVEN THOUGH MUCH OF THIS HAS BEEN
SHOWERS HAVE KEPT THE MENTION OF THUNDER GIVEN THAT WE CONTINUE TO
BE IN A GENERALLY MOIST AND UNSTABLE ENVIRONMENT. THERE CONTINUES
TO BE A FAIR AMOUNT OF UNCERTAINTY WHERE AND WHEN THE BETTER
SHOWERS AND THUNDERSTORMS SETUP ACROSS THE REGION OVER THE NEXT 24
HOURS. THIS DISAGREEMENT IS ALSO PREVALENT IN MUCH OF THE MESO
MODEL GUIDANCE AS WELL. EITHER WAY THE NEXT BEST WAVE LOOKS TO
MOVE THROUGH...AS WE MOVE INTO TUESDAY MORNING. GIVEN THIS THE
CURRENT POP GRIDS LOOK DECENT. DID UPDATE GRIDS WITH LATEST OBS
AND TRENDS...OTHERWISE GIVEN UNCERTAINTY NO MAJOR CHANGES PLANNED
THIS UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 405 PM EDT MON APR 6 2015
THE REGION WAS IN A SOMEWHAT ZONAL PATTERN WITH WEST TO WEST
SOUTHWESTERLY FLOW ALOFT BETWEEN A TROUGH OVER EASTERN CANADA AND
THE NORTHERN GREAT LAKES AND A RIDGE CENTERED OVER THE GULF OF
MEXICO. FURTHER WEST...A TROUGH WAS GRADUALLY WORKING ONSHORE OF
THE WEST COAST OF THE CONUS. A SHORTWAVE TROUGH WORKING FROM THE
NORTHERN GREAT LAKES INTO THE NORTHEASTERN CONUS WILL PUSH A COLD
FRONT SOUTH FROM THE GREAT LAKES REGION DOWN TO NEAR THE I 70
CORRIDOR OR SLIGHT SOUTH OF THAT...BUT REMAIN NORTH OF THE OH
RIVER. THEN...AS THE TROUGH WORKS FURTHER INTO THE WESTERN
CONUS...THIS BOUNDARY WILL RETREAT NORTH LATE IN THE SHORT TERM
PERIOD WITH AND AN OLD BOUNDARY CURRENTLY EXTENDING FROM THE
CENTRAL PLAINS INTO THE DEEP SOUTH ALSO BECOMING MORE ILL DEFINED
AND RETREATING NORTH...POSSIBLY NORTH OF THE OH RIVER LATE. THIS
WILL OCCUR AS HEIGHTS RISE ACROSS THE SOUTHEASTERN CONUS.
AN AREA OF SHOWERS AND VERY FEW EMBEDDED THUNDERSTORMS AT PRESENT
IS APPROACHING OF EASTERN KENTUCKY FROM CENTRAL AND WESTERN KY AND
MIDDLE TN ASSOCIATED WITH ISENTROPIC LIFT OVER THE BOUNDARY TO OUR
SOUTHWEST AND WEST. RAINFALL OF NEARLY A HALF OF AN INCH HAS
OCCURRED AT KBNA. THE GENERAL MODEL CONSENSUS IS FOR THIS ACTIVITY
TO BE MOST WIDESPREAD ACROSS THE SOUTHERN CWA DURING THIS
EVENING...ALTHOUGH ISOLATED TO SCATTERED ACTIVITY IS POSSIBLE
ACROSS THE NORTH. NOT MUCH IN THE WAY OF THUNDER IS EXPECTED WITH
THIS AS THE ATMOSPHERE CONTINUES TO MOISTEN. HOWEVER...SOME
LOCALLY HIGHER RAINFALL IS POSSIBLE IN ANY HEAVIER SHOWERS OR ANY
THUNDERSTORMS.
AFTER THAT...MCS ACTIVITY SHOULD BEGIN TO DEVELOP SOUTH OF THE
FRONT TO OUR NORTH AND POSSIBLY NEARER TO THE BOUNDARY TO THE
SOUTHWEST OF THE AREA. CONFIDENCE IN THE DETAILS AND EVOLUTION OF
THIS IS NOT HIGH...WITH DIFFERENCES FROM MODEL RUN TO MODEL RUN.
HOWEVER... PRECIP CHANCES APPEAR BEST THIS EVENING...WITH SOMEWHAT
OF A LULL TOWARD MIDNIGHT INTO THE OVERNIGHT HOURS. TOWARD DAWN
AND INTO TUESDAY MORNING APPEARS TO BE THE NEXT PERIOD WITH THE
HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS. THE NORTHERN PART
OF THE AREA COULD EXPERIENCE THE MORE PERSISTENT ACTIVITY OR AT
LEAST QPF FROM THIS AS THEY WILL BE CLOSER TO THE BOUNDARY. THE
MODEL CONSENSUS IS FOR A SHORTWAVE TROUGH TO MOVE THROUGH THE
REGION TOMORROW AFTERNOON INTO TOMORROW EVENING...WITH HEIGHTS
THEN RISING ACROSS THE SOUTHEASTERN CONUS. WITH THE LOSS OF
DAYTIME HEATING AND THE BOUNDARY RETREATING NORTH...CHANCES FOR
SHOWERS AND THUNDERSTORMS APPEAR AS IF THEY WOULD DECREASE FOR A
WHILE FROM MID TO LATE EVENING INTO THE OVERNIGHT HOURS.
HOWEVER... ADDITIONAL WEAK WAVES IN THE FLOW MAY LEAD TO NOCTURNAL
DEVELOPMENT IN THE WARM AND MOIST AIRMASS IN PLACE ACROSS THE OH
VALLEY AND MS VALLEY REGION LATE IN THE PERIOD.
WITH A MUCH MORE MOIST AIRMASS IN PLACE AND RATHER PERSISTENT
CLOUD COVER EXPECTED FOR MUCH OF THE PERIOD...DIURNAL RANGES WILL
BE MORE LIMITED THAN RECENT DAYS. PARTIAL CLEARING COULD BRING
SMALL RIDGE/VALLEY SPLITS TONIGHT AND OR TUESDAY NIGHT IF AND
WHERE IT OCCURS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 405 PM EDT MON APR 6 2015
THE EXTENDED PERIOD LOOKS TO BE QUITE ACTIVE WITH MULTIPLE
IMPULSES RIDING OVER A BROAD RIDGE SET UP ACROSS THE EASTERN
CONUS...AND A WARM FRONT STALLED OUT NORTH OF THE REGION.
THE IMPULSES MOVING OVER THE RIDGE AND ALONG THE BOUNDARY
WILL BRING RAIN AND THUNDERSTORM CHANCES THROUGH THE END OF
THE WORK WEEK. THE RISK OF ORGANIZED AND MORE THREATENING
STORMS DEVELOPS LATER THURSDAY AND CONTINUES THROUGH FRIDAY
DUE TO THE APPROACHING SFC LOW AND TROF. THE SFC LOW THEN
LIFTS TOWARDS THE GREAT LAKES REGION ON FRIDAY WITH A SLOW
MOVING COLD FRONT PASSING THROUGH THE AREA FRIDAY EVENING.
THERE ARE SOME DIFFERENCES BETWEEN THE MODELS ON THE TIMING
OF THE FRONTAL PASSAGE SO HAVE WENT WITH A COMPROMISE BETWEEN
GFS/ECMWF. ADDITIONALLY... THERE WILL BE AMPLE MOISTURE FOR
THE STORMS TO TAP INTO...WITH PW VALUES EXCEEDING 1.25" OR ABOVE 2
STANDARD DEVIATIONS ABOVE NORMAL. THEREFORE...MODERATE TO HEAVY
RAINFALL WILL BE A THREAT FOR THE END OF THE WEEK.
DRIER WEATHER RETURNS FOR THE WEEKEND AS A SFC RIDGE BUILDS IN
OVER THE OHIO VALLEY. THIS WILL ALSO BRING MORE SEASONABLE
TEMPERATURES TO THE STATE FOLLOWING A WEEK OF WELL ABOVE NORMAL
TEMPERATURES....WHERE SOME LOW 80S COULD BE SEEN...DESPITE THE
CLOUDINESS AND PERIODS OF RAIN. THE BEGINNING OF NEXT WEEK BRINGS
MORE CHANCES FOR RAIN AS ANOTHER TROF AND SURFACE LOW MOVES
TOWARDS OUR AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 210 AM EDT TUE APR 7 2015
THE LATEST HRRR AND NAM12 HOLD OFF ON ANY SIGNIFICANT PCPN MOVING
INTO EAST KENTUCKY UNTIL CLOSER TO 12Z. THIS LINES UP WELL WITH A
CLUSTER OF SHOWERS AND THUNDERSTORMS NOW MOVING THROUGH SOUTHERN
ILLINOIS...INDIANA AND NORTHWEST KENTUCKY. MVFR CIGS WILL BE THE
RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD AS THIS INITIAL
WAVE APPROACHES AND PASSES THROUGH THIS MORNING FOLLOWED BY
ANOTHER POSSIBLE IMPULSE LATER THIS EVENING WITH ADDITIONAL LOW
CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS
WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS.
THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT
5 TO 10 KTS...EXCEPT IN HIGHER GUSTS IN STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JP
LONG TERM...JVM/GREIF
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1009 PM EDT WED APR 8 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE
TO WEAKEN OVERNIGHT...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A
WARM FRONT THURSDAY INTO THURSDAY NIGHT. ANOTHER COLD FRONT
CROSSES THE REGION LATE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WHAT`S LEFT OF A DECAYING OH VLY MCS WAS MOVING THROUGH NE NC AS
OF 10 PM. THIS BATCH OF SHOWERS AND SUB-SEVERE THUNDERSTORMS WILL
MOVE OUT OF THE AREA BETWEEN MIDNIGHT-1AM. OTW...A BACKDOOR COLD
FRONT SITS JUST SOUTH OF THE FA AND SHOULD REMAIN STATIONARY
OVERNIGHT. THIS WILL ALLOW LOW OVERCAST CONDITIONS TO CONTINUE
OVERNIGHT WITH SFC HIGH PRESSURE RIDGING DOWN INTO THE LOCAL AREA
FROM THE NORTHEAST. THE NEXT BATCH OF PCPN IS MAKING ITS WAY
THROUGH THE OH VLY LATE THIS EVENING AND IS SHOWN BY THE LATEST
HRRR TO MAKE A RUN AT THE FA BY AROUND 08-09Z...THEN MOVING SE
THRU 15Z. THE HRRR DID A GOOD JOB HANDLING THE MCS THIS EVENING SO
WILL LEAN TOWARD ITS SOLUTION OVERNIGHT AND HAVE ADJUSTED POPS
ACCORDINGLY. LOWS TONIGHT FROM NR 40 MD EASTERN SHORE TO THE
LOW/MID 50S SW.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THE FRONT WILL WEAKEN...WITH DEVELOPING SW FLOW EVENTUALLY
PUSHING IT BACK NWD AS A WARM FRONT BY LATE THU. HIGHS THU WILL
RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO M70S WITH
MORE TIME IN THE WARM SECTOR ACROSS SRN/WRN AREAS. POPS REMAIN IN
THE CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN
PERIODS FOR SCT SHRAS...AND ISOLTD TSTMS ESPECIALLY OVER SRN/WRN
AREAS.
THE SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES
LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA
FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL
SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST
CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG
GUSTY WINDS...HAIL AND HEAVY RAIN...AND HV MAINTAINED THIS
MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF THE
FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY COMPARED TO
PREVIOUS DAYS AS THE ENTIRE FA RETURNS INTO THE WARM SECTOR. LOOK
FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE
ACROSS SE AREAS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN
DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL
RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL
AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW
OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE
MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS.
FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS
FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT
AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE
MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD
INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES
AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED
SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING
TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE
SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST
TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE
LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP
FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST
DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE
REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S
COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT
PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE
TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO
MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO
RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THE COLD FRONT THAT MOVD THROUGH THE AREA HAS PUSHED INTO NC AND
AN AREA OF CONVECTION IS MOVING THROUGH THE CWA EARLY THIS
EVENING. THE PRECIP WILL HAVE LITTLE TO NO AFFECT ON TAF SITES
WITH ONLY A BRIEF TSTM PSBL IN RIC AND A CHANCE FOR A FEW SHOWERS
IN ORF AND PHF. WIDESPREAD STRATUS CONTINUES TO AFFECT THE REGION
WITH MVFR/IFR CONDS AND THIS IS EXPECTED TO CONTINUE THROUGH THE
OVERNIGHT WITH CIGS AND VSBY LOWERING TO LIFR AT ALL SITES. SOME
-RA IS POSSIBLE OVERNIGHT...BUT THERE IS ENOUGH UNCERTAINTY. CIGS
SHOULD SLOWLY LIFT THURSDAY MORNING WITH MORE IMPROVEMENT DURING
THE AFTERNOON AS THE BOUNDARY LIFTS BACK THROUGH THE REGION AS A
WARM FRONT. A COLD FRONT CROSSES THE REGION FRIDAY AFTERNOON AND
EVENING BRINGING SHRA/TSRA...ALONG WITH A BREEZY SSW WIND AHEAD OF
THE FRONT. HIGH PRESSURE RETURNS SATURDAY AND SUNDAY AND MOVES
OFFSHORE MONDAY.
&&
.MARINE...
BACKDOOR COLD FRONT HAS LOCATED JUST SOUTH AND WEST OF THE WATER
THIS AFTERNOON. THE RESULT IS N-NE FLOW...AVG 10-15 KT. STRONGER
GRADIENT EXISTS OVER THE NRN COASTAL WATERS...WHERE A FEW GUSTS 25-
28 KT OBSERVED. SEAS HAVE BUILT TO 6-8 FT OVER THE NRN COASTAL
ZONES...GENERALLY NORTH OF PARRAMORE ISLAND. FARTHER SOUTH...SEAS
AVG 2-4 FT. SCA HEADLINES REMAIN IN EFFECT NORTH OF CAPE CHARLES
LIGHT FOR SEAS. GRADIENT WINDS EXPECTED TO DIMINISH TONIGHT AOB 15
KT...BUT SEAS WILL REMAIN ELEVATED (4-7 FT) AS NE FLOW PERSISTS.
BACKDOOR FRONT REMAINS JUST SOUTH AND WEST OF THE WATER
THURS...SLOWLY LIFTING BACK NWD. FLOW BECOMES MORE ONSHORE...E-NE
GENERALLY 10-15 KT. SEAS REMAIN 4-6 FT NORTH OF PARRAMORE
ISLAND...DROPPING BELOW 5 FT SOUTH. BACKDOOR FRONT LIFTS NORTH OF
THE WATER FINALLY THURS NIGHT-FRI MORNING AS A WARM FRONT. FLOW
BECOMES SLY...INCREASING TO AROUND 15 KT RIVERS/BAY/SOUND AND 20 KT
COASTAL WATERS. MARGINAL SCA CONDITIONS ARE POSSIBLE FRI AFTERNOON
AS THE GRADIENT STRENGTHENS IN ADVANCE OF AN APPROACHING COLD FRONT.
WILL HOLD OFF ON HEADLINES DUE TO 4TH PERIOD AND BEING MARGINAL
ATTM. COLD FRONT CROSSES THE WATERS FRI NIGHT...WITH FLOW BECOMING
NWLY POST FRONTAL. BEST CAA REMAINS NORTH OF THE LOCAL AREA...BUT A
FEW GUSTS TO 20 KT POSSIBLE IN THE BAY AND 25 KT COASTAL WATERS
BRIEFLY LATE FRI NIGHT-EARLY SAT MORNING. SEAS BUILD TO 4-6 FT FRI
NIGHT. HIGH PRESSURE BUILDS OVER THE WATERS THIS WEEKEND...RESULTING
IN SUB-SCA CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ654.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...MAS
NEAR TERM...JDM
SHORT TERM...MAS/MAM
LONG TERM...SAM
AVIATION...AJZ/JEF
MARINE...SAM
ADDRESSED IN PREVIOUS FORECAST DISCUSSIONS. THE BIGGEST UNKNOWN IS
WHAT THE POTENTIAL FOR WET BULB COOLING WILL BE AS DEWPOINTS HAVE
BEEN FORECASTED TO BE AROUND THE 32 DEGREE MARK. THE IDEA THIS
PACKAGE IS TO FAVOR A WARMER SOLUTION GIVEN THE OVERALL AMOUNT OF
MIDLEVEL WARM AIR ADVECTION THAT IS EXPECTED TO OCCUR. MOS GUIDANCE
IS WARM WITH SURFACE TEMPERATURES AT BAD AXE WELL ABOVE THE FREEZING
MARK...AND ALSO WARM WITH SURFACE DEWPOINTS. WHILE IT REMAINS
POSSIBLE THAT ISOLATED LOCATIONS COULD SEE SOME LIGHT FREEZING RAIN
OCCUR ON ELEVATED SURFACES...THE BREADTH OF MODEL OUTPUT ALONG WITH
COLLABORATIVE CONCERNS
LONG TERM...WEDNESDAY THROUGH NEXT TUESDAY
THE LONG TERM FORECAST LOOKS TO START OFF QUITE WET AS AN ACTIVE
PATTERN REMAINS OVER THE GREAT LAKES THROUGH FRIDAY. TO START OFF
WEDNESDAY MORNING...A WEAK SURFACE LOW TRACKING ALONG A STATIONARY
FRONT WILL BRING SOME LIGHT RAINS SHOWERS TO SOUTHEAST MICHIGAN.
WHILE THERE IS A POTENTIAL FOR SOME THUNDER ASSOCIATED WITH THESE
SHOWERS /ESPECIALLY TOWARDS THE OHIO BORDER/ ...INSTABILITY IS
UNIMPRESSIVE FOR WEDNESDAY AND CONFIDENCE IS LOW THAT THUNDERSTORMS
WILL DEVELOP. OVERALL...CURRENT THINKING IS THAT WHILE CURRENT MODEL
RUNS SHOW RAIN PRETTY MUCH THROUGHOUT ALL OF WEDNESDAY... THE BEST
CHANCE FOR THESE SHOWERS WILL BE IN THE MORNING HOURS...WITH A BRIEF
DRY PERIOD OR AT LEAST RAIN BECOMING MORE SCATTERED IN THE AFTERNOON
AS SUBSIDENCE MAKES ITS WAY INTO THE REGION. HIGH TEMPERATURES WILL
BE FAIRLY COOL ON WEDNESDAY /MID TO UPPER 40S/ ACROSS THE REGION.
RAIN SHOWERS RETURN AS A STRONGER AND DEEPER LOW PRESSURE SYSTEM
TRACKS ACROSS MICHIGAN EARLY THURSDAY MORNING. THIS LOW WILL FORCE A
WARM FRONT INTO THE REGION...BRINGING A ROUND A RAIN SHOWERS AND
THUNDERSTORMS AFTER SUNRISE. WITH BETTER FORCING AND PLENTY OF
MOISTURE...CONFIDENCE IN THUNDERSTORM DEVELOPMENT IS HIGHER. MAIN
CONCERN WITH THIS SYSTEM IS ON THE TRACK AND HOW FAR NORTH THE WARM
FRONT CAN PUSH. THE FURTHER NORTH THE WARM FRONT CAN SLIDE...THE
FURTHER NORTH THE WARM AIR CAN ALSO FILTER. THIS WARM FRONT WILL
DETERMINE HOW HIGH OUR MAX TEMPS ON THURSDAY WILL GET...WHICH COULD
BE A DIFFERENCE OF NEARLY 15 DEGREES DEPENDING ON IF/WHEN/HOW FAR
THE FRONT SLIDES. FOR NOW...HAVE OPTED TO GO WITH THE FURTHER NORTH
TRACK AS MODELS ARE TRENDING ON MORE NORTHERLY ROUTE IN RECENT RUNS.
THIS WILL ALLOW TEMPS ON THURSDAY TO MAKE IT INTO THE UPPER 60S IN
THE SOUTHERN CWA AND ONLY IN THE MID 50S ACROSS THE SAGINAW VALLEY
AND NORTHERN THUMB. DEPENDING ON HOW FAR NORTH THE LOW TRACKS WE
COULD ALSO BE IMPACTED BY THE COLD FRONT WITH THE SYSTEM. THIS WOULD
BRING ANOTHER ROUND OF MORE INTENSE SHOWERS AND THUNDERSTORMS TO
SOUTHEAST MICHIGAN LATE THURSDAY AFTERNOON AND EVENING. FOR NOW HAVE
KEPT OUT ANY MENTION OF SEVERE WEATHER ON THURSDAY AFTERNOON AS THE
TRACK OF THE SYSTEM IS STILL UNCERTAIN...HOWEVER WILL HAVE TO KEEP
AN EYE ON THIS SYSTEM OVER THE NEXT DAY TO DETERMINE IF ANY SEVERE
WEATHER WILL BE ANTICIPATED.
FOR FRIDAY AND THE WEEKEND...RAIN SHOWERS WILL MOVE EASTWARD ON
FRIDAY MORNING...FOLLOWED BY SURFACE HIGH PRESSURE BUILDING INTO THE
AREA RESULTING IN A RETURN TO DRY WEATHER. THIS HIGH WILL STICK
AROUND THROUGH SUNDAY RESULTING IN NICE SPRINGTIME WEATHER /HIGHS IN
THE MID 50S TO LOW 60S AND PARTLY CLOUDY SKIES/. THE NEXT WEATHER
MAKER ARRIVES MONDAY...BUT THE TIMING IS VERY INCONSISTENT AMONG
MODELS AND THEREFORE ONLY FELT CONFIDENT PUTTING IN CHANCE POPS FOR
THE MONDAY THROUGH TUESDAY TIMEFRAME. HIGH TEMPS WILL REMAIN IN THE
UPPER 50S TO LOW 60S ON MONDAY AND TUESDAY.
MARINE...
STRONG GUSTY NORTHWEST WINDS WILL BEGIN TUESDAY NIGHT AND LAST
THROUGH WEDNESDAY. WINDS COULD REACH UP TO 25 KNOTS OVER LAKE HURON
DURING THIS TIMEFRAME WITH WAVES BUILDING OVER 4 FEET ACROSS THE
LAKE HURON NEARSHORE WATERS. THEREFORE... SMALL CRAFT ADVISORIES
REMAIN IN EFFECT UNTIL WEDNESDAY EVENING. IN ADDITION TO GUSTY
WINDS...RAIN WILL BE POSSIBLE TUESDAY NIGHT AND INTO WEDNESDAY AS A
WEAK LOW PRESSURE SYSTEM SLIDES ACROSS THE AREA. A BETTER CHANCE FOR
RAIN AS WELL AS THUNDERSTORMS WILL ARRIVE WEDNESDAY NIGHT AND INTO
THURSDAY AS A STRONGER LOW TRACKS ACROSS THE CENTRAL GREAT LAKES.
WIND GUSTS ARE EXPECTED TO INCREASE UP TO 30 KNOTS IN SOME LOCATIONS
WITH THIS SYSTEM. SMALL CRAFT ADVISORIES MAY BE NEEDED ONCE AGAIN
FOR THURSDAY NIGHT AND FRIDAY MORNING. HIGH PRESSURE...DRY
CONDITIONS...AND CALMER WINDS RETURN FOR FRIDAY AND INTO THE
WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT WEDNESDAY FOR LHZ421-441.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LHZ442.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
UPDATE.......BT
SHORT TERM...CB
LONG TERM....RK
MARINE.......RK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 PM EDT TUE APR 7 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 448 PM EDT TUE APR 7 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THAT THE CONFLUENT FLOW
THAT HAS BEEN ACROSS THE UPPER GREAT LAKES IS SHIFTING E AND NE AS
THE NRN STREAM TROF OVER ERN CANADA IS SLOWLY LIFTING OUT AND SRN
BRANCH RIDGE OVER THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST IS
GRADUALLY BUILDING NE AND E. SFC HIGH PRES SUPPORTED BY THE
CONFLUENT FLOW ALOFT RIDGES W-E ACROSS NRN ONTARIO INTO SRN QUEBEC.
ALTHOUGH THERE HAVE BEEN SOME MID-LEVEL RADAR RETURNS ACROSS THE
FCST AREA...ESPECIALLY EARLIER TODAY...THE VERY DRY AIR AT THE LOWER
LEVELS EMANATING FROM THE HIGH PRES RIDGE HAS RESULTED IN DRY
WEATHER ACROSS THE FCST AREA TODAY. IN FACT...THE KEWEENAW AND ERN
UPPER MI HAVE ENJOYED MOSTLY SUNNY SKIES FOR A GOOD PART OF THE DAY.
TO THE S...WARM FRONT/STATIONARY FRONT EXTENDS FROM KS ACROSS CNTRL
IL INTO NRN OHIO. TO THE W AND SW...A WELL-DEFINED SHORTWAVE IS
TRACKING ENE ACROSS SE SASKATCHEWAN WHILE WEAKER WAVES ARE MOVING
ACROSS WY/CO AND OUT ACROSS THE PLAINS. THESE FEATURES WILL PLAY A
ROLE IN A CHALLENGING FCST HERE TONIGHT/WED.
INITIALLY...EXPECT DRY WEATHER TO PREVAIL THIS EVENING UNDER A
CONTINUED FEED OF DRY LOW-LEVEL AIR FROM THE E AND NE. SFC DWPTS AS
OF 19Z WERE STILL MOSTLY IN THE 5-10F RANGE ALONG THE MI/WI
BORDER...INDICATING THE DRYNESS THAT IS STILL AT THE SFC...AND
LATEST RAP FCST SOUNDINGS SHOW THE DRY AIR IN THE LOWER LEVELS
HANGING ON DURING THE EVENING. LATER TONIGHT INTO WED...FOCUS SHIFTS
TO THE AFORMENTIONED SHORTWAVES. THE STRONGER NRN WAVE WILL REACH
NRN ONTARIO EARLY WED MORNING WHILE THE WEAKER SRN WAVES WILL TRACK
INTO THE UPPER LAKES. TRACK OF THE STRONGER NRN WAVE INDICATES ITS
MAIN FORCING WILL PASS N OF HERE...AND THAT IS WHAT MODELS SHOW FOR
PROGRESSION OF DEEP LAYER QVECTORS. FARTHER S...THE WEAKER SRN WAVES
WILL BE ABLE TO INTERACT WITH THE SFC-850MB WARM FRONT AND
CONSIDERABLY MORE GENEROUS MOISTURE AS WELL AS ABUNDANT INSTABILITY.
LEAD SUBTLE WAVE IS ALREADY GENERATING AN EXPANDING AREA OF
SHRA/TSRA IN SRN MN/NW IA ON THE MUCAPE GRADIENT PER LATEST SPC
MESOANALYSIS. THRU WED MORNING...MODELS SHOW 850MB WARM FRONT NEVER
LIFTING ANY FARTHER N THAN SRN WI. BELIEVE THOSE MODEL SOLUTIONS
WHICH SHOW THE MAIN AREA OF PCPN PASSING S OF UPPER MI TONIGHT/WED
MORNING CLOSER TO 850MB WARM FRONT OR EVEN SFC FRONT ARE PROBABLY ON
THE RIGHT TRACK. THIS WOULD BE ESPECIALLY TRUE IF SIGNIFICANT
CONVECTION ENDS UP DEVELOPING/EXPANDING NEAR THE WARM FRONT...A
DEFINITE POSSIBILITY GIVEN THE MAGNITUDE OF INSTABILITY THAT WILL
REMAIN MUCH FARTHER S. WHILE THE SHRA/TSRA MOVING ACROSS SRN MN INTO
SW WI IS A CONCERN...THAT PCPN SHOULD TEND TO PEEL MORE EASTWARD
WITH TIME AS THE SHRA/TSRA SHOULDN`T BREAK TOO FAR AWAY FROM THE
INSTABILITY GRADIENT WHICH WILL REMAIN WELL S OF HERE. SO...THE GFS
WHICH CARRIES 1/3RD TO 1/2 INCH OF PCPN INTO SCNTRL UPPER MI
CERTAINLY LOOKS LIKE AN OUTLIER COMPARED TO THE OTHER MODELS WHICH
ARE MUCH LIGHTER ON PCPN. NONETHELESS...TAIL END OF NRN SHORTWAVE
WILL PROVIDE SUPPORT FOR AN EXTENSION OF PCPN N AND NW FROM HEAVIER
PCPN TO THE S. UTILIZING A CONSENSUS APPROACH FOR POPS...WEIGHTED
TOWARD HIGH RES GUIDANCE...WILL SPREAD A BAND OF CHC POPS ACROSS THE
AREA OVERNIGHT/WED MORNING WITH TREND TOWARD LOWER POPS OVER THE
NRN/ERN FCST AREA. WILL INCLUDE LIKELY POPS INTO MENOMINEE COUNTY.
PCPN WILL END (OR DIMINISH TO DZ BEFORE ENDING) FROM SW TO NE MID
MORNING THRU EARLY AFTN.
PTYPE IS A CHALLENGE. INITIAL DRY AIR MASS/EVAPORATIVE COOLING
SHOULD MAKE SNOW THE MORE DOMINANT PTYPE. HOWEVER...PERUSAL OF MODEL
FCST SOUNDINGS SHOW TEMP PROFILE HOVERING AROUND 0C OVER A FAIRLY
SIGNIFICANT DEPTH...INDICATING A VARIETY OF PTYPES WILL BE POSSIBLE
WITH ONLY VERY SLIGHT CHANGES TO THE TEMP PROFILE. SO...FCST WILL
REFLECT A WINTRY MIX OF SN/IP/FZRA/RA AT MOST LOCATIONS...THOUGH
MAINLY SN IS MORE LIKELY IN HIGHER TERRAIN AREAS. FOR PCPN
AMOUNTS...EXPECT TOTAL WATER EQUIVALENT PCPN OF ROUGHLY 0.05 TO 0.15
INCHES....GREATEST SCNTRL. SNOW AMOUNTS SHOULD BE UNDER 1 INCH...AND
WHERE FRZA OCCURS...A COUPLE OF HUNDREDTHS ARE POSSIBLE. AT THIS
POINT...ADVY HEADLINES ARE NOT WARRANTED. IF FOR SOME REASON TRENDS
THIS EVENING POINT TOWARD HEAVIER PCPN REACHING THE AREA...HEADLINES
WILL NEED TO BE RECONSIDERED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 414 PM EDT TUE APR 7 2015
...AREAS OF FREEZING RAIN/ICING WED NIGHT INTO THU MORNING AND
POSSIBLE HEAVY SNOW THU NIGHT...
LARGE SCALE UPPER LEVEL PATTERN TO START THE LONG TERM FEATURES
TROUGHING FM CENTRAL CANADA SOUTHWEST ACROSS MUCH OF THE WESTERN
CONUS. MAIN SHORTWAVES WITHIN THE TROUGH ON WEDNESDAY NIGHT WILL BE
DIVING SOUTHEAST ACROSS MANITOBA AND STREAMING EASTWARD NEAR THE
FOUR CORNERS REGION. MAIN JET STREAKS WITHIN THE FLOW PATTERN ARE
ORIENTED FM GREAT LAKES TO NEW ENGLAND AND PUSHING ACROSS NORTHERN
MEXICO. AT THE SFC...MAIN CYCLONE IS VCNTY OF CNTRL PLAINS WITH WARM
FRONT EAST ACROSS THE OHIO VALLEY...LIFTING NORTHWARD.
WEAKER LEAD SHORTWAVE/INCREASING DIVERGENCE IN RRQ OF GREAT LAKES
JET/WARM AIR ADVECTION COMBINE TO BRING SOME PRECIP IN THE FORM OF
RAIN SHOWERS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING.
GFS/ECMWF/GEM-NH QUICKER IN BRINGING PRECIP OVER AREA...MORE 06Z-12Z
THURSDAY. NAM IS DELAYED...FAVORING 12Z-18Z ON THURSDAY. EITHER WAY
THINK BEST FOCUS FOR RAIN WILL BE ON NOSE OF VEERING H85 JET MAINLY
IMPACTING SOUTH AND EAST CWA. TSRA THAT COULD BE ONGOING ALONG WARM
FRONT COULD FURTHER DISRUPT MOISTURE TRANSPORT INTO UPPER GREAT
LAKES. DUE TO THESE REASONS...LIKE THE IDEA OF LESS QPF SINCE LARGER
SCALE FORCING OVER UPR MICHIGAN IS GENERALLY WEAK. SOUNDINGS AHEAD
OF ANY POTENTIAL PRECIP INDICATE LOW-LEVEL MOISTURE TO H9 BUT DRY
AIR ABOVE THROUGH H5 MUCH OF WEDNESDAY EVENING. SFC WINDS FM EAST
BTWN HIGH PRESSURE RIDGE OVER EASTERN CANADA AND LOW PRESSURE
LIFTING NORTHEAST OVER THE CNTRL PLAINS SUPPORTS BEST CHANCE OF
DZ/FZDZ GENERATED BY UPSLOPE LIFTING OVER HIGHER TERRAIN OF CNTRL
CWA FM MICHIGAMME HIGHLANDS IN BARAGA AND MARQUETTE COUNTY SOUTHWEST
TO MUCH OF IRON AND DICKINSON COUNTIES. EITHER FM THE FZDZ OR
EVENTUALLY ARRIVAL OF LIGHT FZRA...LIGHT ICING IS LIKELY ON
WEDNESDAY NIGHT AS TEMPS WILL STAY AT OR BLO FREEZING MOST OF THE
NIGHT. MAIN CONCERN WOULD BE ON UNTREATED ROADS AND SIDEWALKS BUT
THERE COULD ALSO BE SOME ICING THAT WOULD IMPACT ELEVATED OBJECTS
SUCH AS TREES AND POWERLINES. BEST SHOT OF MOST ICING WILL BE OVER
THE HIGHER TERRAIN AREAS FM BARAGA AND MARQUETTE COUNTY TO IRON AND
DICKINSON COUNTY. DID NOT GET TOO SPECIFIC BTWN DZ/FZDZ AND
RAIN/FZRA. SINCE EVEN IN THE DRIER SCENARIO THERE WOULD BE
MEASURABLE QPF...WENT WITH RAIN/FZRA. WILL KEEP MENTION OF THIS IN
HWO/EHWO...BUT NO HEADLINE ISSUED NOW AS AT THIS POINT SEEMS THAT AT
WORST COULD NEED AN ADVY.
BRIEF LULL POSSIBLE LATER THURSDAY MORNING INTO THURSDAY AFTERNOON
IN BETWEEN SHORTWAVES...LEAD ONE LIFTING ACROSS EASTERN ONTARIO AND
A MUCH STRONGER ONE...EDGING EASTWARD ACROSS CNTRL PLAINS...SET TO
ARRIVE OVER UPR GREAT LAKES THURSDAY NIGHT. SOUNDINGS FOR LATER
THURSDAY INDICATE SOME MOISTURE MAY STICK AROUND ON NORTHERN EDGE OF
SFC LOW LIFTING NORTHEAST FROM THE CNTRL MISSISSIPPI RIVER VALLEY
TOWARD THE WESTERN GREAT LAKES...BUT SEEMS THAT NET FORCING FOR
ANY PRECIP WILL BE MINIMAL. NORTHERN EDGE OF HIGHER MLCAPE AND
INTERSECTION OF LOW-LEVEL AND UPPER LEVEL JET AND H85 THETA-E
AXIS/MAX WARM AIR ADVECTION WOULD KEEP POTENTIAL FOR TSRA STAYING
WELL TO THE SOUTHEAST OF UPR MICHIGAN...LIKELY OVER LOWER GREAT
LAKES OR OHIO VALLEY DEPENDING ON LOCATION OF EMBEDDED WEAKER
CONVECTIVELY DRIVEN SHORTWAVES IN THE WSW FLOW ALOFT. GENERALLY
QUIET WEATHER SHOULD PREVAIL OVER UPPER LAKES THURSDAY AFTN UNTIL
MAIN SHORTWAVE ARRIVES ON THURSDAY NIGHT. MOISTURE ADVECTION INTO
THE AREA MAY CONTINUE TO SPUR ON SOME SHOWERS OR PATCHY RAIN...SO
KEPT CHANCES GOING THROUGH THE PERIOD DESPITE THE MINIMAL FORCING.
MODEL DIFFERENCES WITH STRENGTH AND WESTWARD EXTENT OF THURSDAY
NIGHT SHORTWAVE IS THE MAIN ISSUE ON INTO FRIDAY MORNING. OVERALL...
RECENT NAM/GEM-NH RUNS WERE FARTHER WEST WITH UPPER WAVE AND SFC
LOW WHILE THE 00Z ECMWF WAS MUCH FASTER WITH EASTWARD PUSH OF THE
SHORTWAVE/SFC LOW AND COLD FRONT. GFS REPRESENTED A COMPROMISE
SOLUTION. BY FAR...00Z AND 12Z ECMWF ARE DRIEST...INDICATING LESS
THAN 0.25 INCH OF QPF FM 00Z FRIDAY TO 12Z FRIDAY. MEANWHILE...
NAM/GFS/GEM-NH SHOWED QPF AMOUNTS AT LEAST UP TO 1 INCH...SO QUITE
THE DIFFERENCE.
12Z NAM TRENDED MORE LIKE THE GFS IN TERMS OF LOCATION OF SFC LOW FM
00Z FRIDAY TO 12Z FRIDAY. IN TERMS OF QPF...NAM TRENDED AWAY FM
STRIPE OF 1.5 INCH PLUS AMOUNTS IT WAS SHOWING BUT STILL HAS UP TO
1.25 INCHES OVER PARTS OF WESTERN UPR MICHIGAN. IN FACT...IN THE
VCNTY OF KIWD IS HAS TRENDED MUCH WETTER AS 00Z RUN SHOWED LESS THAN
0.10 INCH...BUT 12Z RUN NOW HAS ALMOST 0.75 INCHES. GUESSING THIS IS
DUE TO MORE PHASING OCCURRING BTWN SHORTWAVE CROSSING THE UPPER
LAKES AND THE APPROACHING WAVE DRIVING SOUTHEAST OVER MANITOBA AND
NORTHERN ONTARIO WHICH IN TURN INCREASES RIGHT ENTRANCE JET STREAK
DIVERGENCE AND ASSOCIATED MID-LEVEL FGEN. 12Z GFS SIMILAR TO
PREVIOUS RUNS WITH SFC LOW POSITION...BUT NOW FOCUSES QPF MORE OVER
WESTERN CWA. GFS SHOWS NOT ONLY MAIN SHORTWAVE LIFTING OVER UPPER
GREAT LAKES AND WAVE OVER NORTHERN ONTARIO...BUT ALSO ANOTHER WAVE
TRYING TO SNEAK IN FM NORTHERN PLAINS. SCENARIO JUST BECOMES MORE
COMPLICATED YET. PTYPE WITH MOST OF THE PRECIP WOULD BE RAIN
CHANGING TO SNOW. POSSIBLE FZRA AS WELL AS ADVECTION OF COLDER LOW-
LEVEL AIRMASS UNDERCUTS LINGERING WARM LAYER ALOFT AT H8-H75. SIGNAL
FOCUSING THAT FAR WEST VCNTY OF KIWD COULD SEE HEAVY SNOW THURSDAY
EVENING INTO THE EARLY MORNING OF FRIDAY DUE TO QUICKER CHANGE FM
RAIN TO SNOW AND GREATER POTENTIAL FOR HEAVIER QPF. WILL CONTINUE TO
MENTION THIS IN THE HWO/EHWO BUT NOT HIT IT UP MUCH HARDER JUST YET
AS UNCERTAINTY REMAINS SINCE THE TYPICALLY BETTER PERFORMING ECMWF
HAS BEEN CONSISTENTLY NOT NEAR AS BULLISH WITH THE SYSTEM AS OTHER
MODELS. AND ITS REALLY NOT EVEN CLOSE.
LOW PRESSURE SYSTEM EXITS ACROSS EASTERN CANADA ON FRIDAY. LINGERING
AIRMASS IS COOL THOUGH AS LOWERED TEMPS WITH THERMAL TROUGH AT H85
REMAINING OVER THE AREA. SHOULD STAY MOSTLY CLOUDY EVEN FARTHER
INLAND WITH POSSIBLE INSTABILITY RAIN/SNOW SHOWERS SINCE THE THERMAL
TROUGH STAYS IN THE VCNTY. HIGH PRESSURE SLIDES OVERHEAD TO START
THE WEEKEND SO LOOKING FOR DRY AND MUCH WARMER CONDITIONS ON
SATURDAY. WINDS BECOME SOUTHWEST AS RIDGE PASSES SATURDAY AFTN.
MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 50S OVER MOST CWA. BY
LATE WEEKEND...UPPER PATTERN SHOWS LARGER TROUGH OVER WESTERN CANADA
AND NORTHWEST CONUS...WITH MORE COMPACT UPPER LOW TRACKING OVER THE
SOUTHWEST CONUS. THERE IS A LOT OF UNCERTAINTY IN HOW THAT SOUTHERN
STREAM WAVE EVOLVES. PREVIOUS ECMWF SHOWED A WRAPPED UP SFC LOW OVER
THE CNTRL PLAINS...WHILE THE 12Z ECMWF SHOWS NOTHING OF THE SORT.
ESSENTIALLY...SEE NO REASON TO STRAY FM CONSENSUS BEYOND THE LATE
WEEK SYSTEM GIVEN THE BIGGER UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 135 PM EDT TUE APR 7 2015
A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING
ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO
UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT
KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE
MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT
ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE
MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE.
EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE
END OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 PM EDT TUE APR 7 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE
FROM NRN ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT
WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO
NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE
STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE
ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE
THE WINDS. IN THAT AREA...EXPECT NE WINDS OF 20-30KT TONIGHT...WITH
SOME GALE FORCE GUSTS TO AROUND 35 KT THRU THE EVENING. E TO NE
WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU
AS LOW PRES LIFTS NE FROM THE CENTRAL PLAINS INTO THE GREAT LAKES
REGION. AT THIS TIME...IT APPEARS THE LOW WILL NOT BE STRONG ENOUGH
TO RESULT IN GALES AS THE LOW APPROACHES AND THEN DEPARTS. WINDS
WILL BACK TO THE N THU AND THEN NW 20-30KT THU NIGHT INTO FRI AS THE
LOW SHIFTS TO THE E AND HIGH PRES BUILDS INTO THE PLAINS. A PERIOD
OF LIGHT WINDS WILL OCCUR FRI NIGHT INTO SAT AS HIGH PRES RIDGE
MOVES ACROSS THE UPPER LAKES. S WINDS WILL THEN BE ON THE INCREASE
TO AT LEAST 10-20KT ON SUN AS THE RIDGE SHIFTS E AND A LOW PRES TROF
MOVES E TO THE UPPER MISSISSIPPI VALLEY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
415 PM EDT TUE APR 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE APR 7 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A
CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN
QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE
W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE
CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS
ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE
DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR
DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF
LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO
THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS.
HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL
RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW
ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO
THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST
OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS
LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS
RDG AND THE TROF ALONG THE W COAST.
MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY
THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS
FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS
AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI.
TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ
OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR
CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL
THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE
DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR
SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI
THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL
DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS
AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY
FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S.
TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV
NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL
CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT
GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE
WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT...
ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR
JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE
ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL
CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL
FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH
OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE
FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE
GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE
SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS
H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES
MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN
EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE
WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE
NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A
CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE
GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE
COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN
AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING
THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT
CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND
VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY
OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT
OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC
COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET
OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW
FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE
POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 414 PM EDT TUE APR 7 2015
...AREAS OF FREEZING RAIN/ICING WED NIGHT INTO THU MORNING AND
POSSIBLE HEAVY SNOW THU NIGHT...
LARGE SCALE UPPER LEVEL PATTERN TO START THE LONG TERM FEATURES
TROUGHING FM CENTRAL CANADA SOUTHWEST ACROSS MUCH OF THE WESTERN
CONUS. MAIN SHORTWAVES WITHIN THE TROUGH ON WEDNESDAY NIGHT WILL BE
DIVING SOUTHEAST ACROSS MANITOBA AND STREAMING EASTWARD NEAR THE
FOUR CORNERS REGION. MAIN JET STREAKS WITHIN THE FLOW PATTERN ARE
ORIENTED FM GREAT LAKES TO NEW ENGLAND AND PUSHING ACROSS NORTHERN
MEXICO. AT THE SFC...MAIN CYCLONE IS VCNTY OF CNTRL PLAINS WITH WARM
FRONT EAST ACROSS THE OHIO VALLEY...LIFTING NORTHWARD.
WEAKER LEAD SHORTWAVE/INCREASING DIVERGENCE IN RRQ OF GREAT LAKES
JET/WARM AIR ADVECTION COMBINE TO BRING SOME PRECIP IN THE FORM OF
RAIN SHOWERS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING.
GFS/ECMWF/GEM-NH QUICKER IN BRINGING PRECIP OVER AREA...MORE 06Z-12Z
THURSDAY. NAM IS DELAYED...FAVORING 12Z-18Z ON THURSDAY. EITHER WAY
THINK BEST FOCUS FOR RAIN WILL BE ON NOSE OF VEERING H85 JET MAINLY
IMPACTING SOUTH AND EAST CWA. TSRA THAT COULD BE ONGOING ALONG WARM
FRONT COULD FURTHER DISRUPT MOISTURE TRANSPORT INTO UPPER GREAT
LAKES. DUE TO THESE REASONS...LIKE THE IDEA OF LESS QPF SINCE LARGER
SCALE FORCING OVER UPR MICHIGAN IS GENERALLY WEAK. SOUNDINGS AHEAD
OF ANY POTENTIAL PRECIP INDICATE LOW-LEVEL MOISTURE TO H9 BUT DRY
AIR ABOVE THROUGH H5 MUCH OF WEDNESDAY EVENING. SFC WINDS FM EAST
BTWN HIGH PRESSURE RIDGE OVER EASTERN CANADA AND LOW PRESSURE
LIFTING NORTHEAST OVER THE CNTRL PLAINS SUPPORTS BEST CHANCE OF
DZ/FZDZ GENERATED BY UPSLOPE LIFTING OVER HIGHER TERRAIN OF CNTRL
CWA FM MICHIGAMME HIGHLANDS IN BARAGA AND MARQUETTE COUNTY SOUTHWEST
TO MUCH OF IRON AND DICKINSON COUNTIES. EITHER FM THE FZDZ OR
EVENTUALLY ARRIVAL OF LIGHT FZRA...LIGHT ICING IS LIKELY ON
WEDNESDAY NIGHT AS TEMPS WILL STAY AT OR BLO FREEZING MOST OF THE
NIGHT. MAIN CONCERN WOULD BE ON UNTREATED ROADS AND SIDEWALKS BUT
THERE COULD ALSO BE SOME ICING THAT WOULD IMPACT ELEVATED OBJECTS
SUCH AS TREES AND POWERLINES. BEST SHOT OF MOST ICING WILL BE OVER
THE HIGHER TERRAIN AREAS FM BARAGA AND MARQUETTE COUNTY TO IRON AND
DICKINSON COUNTY. DID NOT GET TOO SPECIFIC BTWN DZ/FZDZ AND
RAIN/FZRA. SINCE EVEN IN THE DRIER SCENARIO THERE WOULD BE
MEASURABLE QPF...WENT WITH RAIN/FZRA. WILL KEEP MENTION OF THIS IN
HWO/EHWO...BUT NO HEADLINE ISSUED NOW AS AT THIS POINT SEEMS THAT AT
WORST COULD NEED AN ADVY.
BRIEF LULL POSSIBLE LATER THURSDAY MORNING INTO THURSDAY AFTERNOON
IN BETWEEN SHORTWAVES...LEAD ONE LIFTING ACROSS EASTERN ONTARIO AND
A MUCH STRONGER ONE...EDGING EASTWARD ACROSS CNTRL PLAINS...SET TO
ARRIVE OVER UPR GREAT LAKES THURSDAY NIGHT. SOUNDINGS FOR LATER
THURSDAY INDICATE SOME MOISTURE MAY STICK AROUND ON NORTHERN EDGE OF
SFC LOW LIFTING NORTHEAST FROM THE CNTRL MISSISSIPPI RIVER VALLEY
TOWARD THE WESTERN GREAT LAKES...BUT SEEMS THAT NET FORCING FOR
ANY PRECIP WILL BE MINIMAL. NORTHERN EDGE OF HIGHER MLCAPE AND
INTERSECTION OF LOW-LEVEL AND UPPER LEVEL JET AND H85 THETA-E
AXIS/MAX WARM AIR ADVECTION WOULD KEEP POTENTIAL FOR TSRA STAYING
WELL TO THE SOUTHEAST OF UPR MICHIGAN...LIKELY OVER LOWER GREAT
LAKES OR OHIO VALLEY DEPENDING ON LOCATION OF EMBEDDED WEAKER
CONVECTIVELY DRIVEN SHORTWAVES IN THE WSW FLOW ALOFT. GENERALLY
QUIET WEATHER SHOULD PREVAIL OVER UPPER LAKES THURSDAY AFTN UNTIL
MAIN SHORTWAVE ARRIVES ON THURSDAY NIGHT. MOISTURE ADVECTION INTO
THE AREA MAY CONTINUE TO SPUR ON SOME SHOWERS OR PATCHY RAIN...SO
KEPT CHANCES GOING THROUGH THE PERIOD DESPITE THE MINIMAL FORCING.
MODEL DIFFERENCES WITH STRENGTH AND WESTWARD EXTENT OF THURSDAY
NIGHT SHORTWAVE IS THE MAIN ISSUE ON INTO FRIDAY MORNING. OVERALL...
RECENT NAM/GEM-NH RUNS WERE FARTHER WEST WITH UPPER WAVE AND SFC
LOW WHILE THE 00Z ECMWF WAS MUCH FASTER WITH EASTWARD PUSH OF THE
SHORTWAVE/SFC LOW AND COLD FRONT. GFS REPRESENTED A COMPROMISE
SOLUTION. BY FAR...00Z AND 12Z ECMWF ARE DRIEST...INDICATING LESS
THAN 0.25 INCH OF QPF FM 00Z FRIDAY TO 12Z FRIDAY. MEANWHILE...
NAM/GFS/GEM-NH SHOWED QPF AMOUNTS AT LEAST UP TO 1 INCH...SO QUITE
THE DIFFERENCE.
12Z NAM TRENDED MORE LIKE THE GFS IN TERMS OF LOCATION OF SFC LOW FM
00Z FRIDAY TO 12Z FRIDAY. IN TERMS OF QPF...NAM TRENDED AWAY FM
STRIPE OF 1.5 INCH PLUS AMOUNTS IT WAS SHOWING BUT STILL HAS UP TO
1.25 INCHES OVER PARTS OF WESTERN UPR MICHIGAN. IN FACT...IN THE
VCNTY OF KIWD IS HAS TRENDED MUCH WETTER AS 00Z RUN SHOWED LESS THAN
0.10 INCH...BUT 12Z RUN NOW HAS ALMOST 0.75 INCHES. GUESSING THIS IS
DUE TO MORE PHASING OCCURRING BTWN SHORTWAVE CROSSING THE UPPER
LAKES AND THE APPROACHING WAVE DRIVING SOUTHEAST OVER MANITOBA AND
NORTHERN ONTARIO WHICH IN TURN INCREASES RIGHT ENTRANCE JET STREAK
DIVERGENCE AND ASSOCIATED MID-LEVEL FGEN. 12Z GFS SIMILAR TO
PREVIOUS RUNS WITH SFC LOW POSITION...BUT NOW FOCUSES QPF MORE OVER
WESTERN CWA. GFS SHOWS NOT ONLY MAIN SHORTWAVE LIFTING OVER UPPER
GREAT LAKES AND WAVE OVER NORTHERN ONTARIO...BUT ALSO ANOTHER WAVE
TRYING TO SNEAK IN FM NORTHERN PLAINS. SCENARIO JUST BECOMES MORE
COMPLICATED YET. PTYPE WITH MOST OF THE PRECIP WOULD BE RAIN
CHANGING TO SNOW. POSSIBLE FZRA AS WELL AS ADVECTION OF COLDER LOW-
LEVEL AIRMASS UNDERCUTS LINGERING WARM LAYER ALOFT AT H8-H75. SIGNAL
FOCUSING THAT FAR WEST VCNTY OF KIWD COULD SEE HEAVY SNOW THURSDAY
EVENING INTO THE EARLY MORNING OF FRIDAY DUE TO QUICKER CHANGE FM
RAIN TO SNOW AND GREATER POTENTIAL FOR HEAVIER QPF. WILL CONTINUE TO
MENTION THIS IN THE HWO/EHWO BUT NOT HIT IT UP MUCH HARDER JUST YET
AS UNCERTAINTY REMAINS SINCE THE TYPICALLY BETTER PERFORMING ECMWF
HAS BEEN CONSISTENTLY NOT NEAR AS BULLISH WITH THE SYSTEM AS OTHER
MODELS. AND ITS REALLY NOT EVEN CLOSE.
LOW PRESSURE SYSTEM EXITS ACROSS EASTERN CANADA ON FRIDAY. LINGERING
AIRMASS IS COOL THOUGH AS LOWERED TEMPS WITH THERMAL TROUGH AT H85
REMAINING OVER THE AREA. SHOULD STAY MOSTLY CLOUDY EVEN FARTHER
INLAND WITH POSSIBLE INSTABILITY RAIN/SNOW SHOWERS SINCE THE THERMAL
TROUGH STAYS IN THE VCNTY. HIGH PRESSURE SLIDES OVERHEAD TO START
THE WEEKEND SO LOOKING FOR DRY AND MUCH WARMER CONDITIONS ON
SATURDAY. WINDS BECOME SOUTHWEST AS RIDGE PASSES SATURDAY AFTN.
MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 50S OVER MOST CWA. BY
LATE WEEKEND...UPPER PATTERN SHOWS LARGER TROUGH OVER WESTERN CANADA
AND NORTHWEST CONUS...WITH MORE COMPACT UPPER LOW TRACKING OVER THE
SOUTHWEST CONUS. THERE IS A LOT OF UNCERTAINTY IN HOW THAT SOUTHERN
STREAM WAVE EVOLVES. PREVIOUS ECMWF SHOWED A WRAPPED UP SFC LOW OVER
THE CNTRL PLAINS...WHILE THE 12Z ECMWF SHOWS NOTHING OF THE SORT.
ESSENTIALLY...SEE NO REASON TO STRAY FM CONSENSUS BEYOND THE LATE
WEEK SYSTEM GIVEN THE BIGGER UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 135 PM EDT TUE APR 7 2015
A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING
ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO
UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT
KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE
MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT
ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE
MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE.
EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE
END OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT TUE APR 7 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW
ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO
THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL
PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER
WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN
NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN
THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO
THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON
WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS
TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR
LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU
NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 PM EDT TUE APR 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE APR 7 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A
CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN
QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE
W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE
CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS
ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE
DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR
DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF
LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO
THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS.
HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL
RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW
ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO
THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST
OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS
LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS
RDG AND THE TROF ALONG THE W COAST.
MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY
THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS
FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS
AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI.
TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ
OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR
CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL
THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE
DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR
SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI
THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL
DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS
AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY
FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S.
TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV
NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL
CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT
GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE
WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT...
ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR
JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE
ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL
CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL
FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH
OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE
FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE
GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE
SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS
H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES
MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN
EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE
WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE
NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A
CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE
GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE
COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN
AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING
THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT
CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND
VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY
OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT
OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC
COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET
OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW
FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE
POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM EDT TUE APR 7 2015
THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH
PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL
TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH
WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS
POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE.
TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE
PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION
WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING.
THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND
WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF
PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE
START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY
LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE
U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL
MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB
FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE
DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE
GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF
THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW
SLIGHT CHANCE POPS FOR THE DRIZZLE.
ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF
THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING
THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES
THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO
WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE
TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING
NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE
U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST
WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS
LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF
LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH
900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST
FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH
LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING
RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST
COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES
ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD
SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE
CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND
KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE
IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF
ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS
FREEZING RAIN THREAT IN THE HWO.
AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY
AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE
SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN
LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION
OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE
AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE
LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF
THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN
DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE
MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS
AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME.
AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE
FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE)
WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK
MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF
REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS
TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE
NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS
PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY
FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND
THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST.
WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN
SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF
A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP
IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER
THE NEXT SEVERAL SHIFTS.
THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT
AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES
EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR
BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT
LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH
MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON
SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR
TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S
OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW
WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING
ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA
SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE
THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW
INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 135 PM EDT TUE APR 7 2015
A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING
ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO
UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT
KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE
MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT
ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE
MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE.
EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE
END OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT TUE APR 7 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW
ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO
THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL
PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER
WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN
NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN
THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO
THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON
WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS
TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR
LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU
NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1210 PM EDT TUE APR 7 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 329 AM EDT TUE APR 7 2015
THE AREA WILL SEE A RELATIVELY WET PERIOD THROUGH MOST OF THE REST
OF THIS WEEK. A STALLED OUT FRONTAL SYSTEM WILL REMAIN IN THE
REGION. THE AREA WILL BE ON THE COOL NORTH SIDE OF THIS FRONT
THROUGH WEDNESDAY. ROUNDS OF SHOWERS AND EVENTUALLY STORMS CAN BE
EXPECTED. THE FRONT WILL LIFT NORTH OF THE AREA ON THURSDAY AND
BRING WARMER AIR INTO THE AREA. STORMS WILL BECOME MORE LIKELY ON
THURSDAY WITH A THREAT FOR SOME SEVERE WEATHER POSSIBLE DOWN SOUTH.
CONDITIONS WILL QUIET DOWN THEN FOR THE END OF THE WORK WEEK AND
NEXT WEEKEND AS THE ENTIRE FRONTAL SYSTEM PUSHES OUT OF THE AREA.
&&
.UPDATE...
ISSUED AT 1142 AM EDT TUE APR 7 2015
BEST COVERAGE OF SCATTERED RAIN SHOWERS THIS AFTERNOON SHOULD BE
SOUTH OF I-96 CLOSER TO THE H8 BAROCLINIC ZONE. LATEST HRRR IS
FAVORING THE AREA EAST AND SOUTH OF A LINE FROM AZO TO LAN.
FARTHER NORTH AND WEST... MAINLY ISOLATED COVERAGE OF SHOWERS AT
BEST. H5 PROGS SHOW SEVERAL VORTICITY MAXIMA EMBEDDED IN ZONAL
FLOW ALOFT SO AM RELUCTANT TO GO COMPLETELY DRY IN THE NRN CWFA
AFTER 18Z. TEMPS WILL STRUGGLE TO GET OUT OF THE 40S THIS AFTEROON
WITH CLOUDS AND BRISK EAST FLOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 329 AM EDT TUE APR 7 2015
OUR MAIN CHALLENGES IN THE SHORT TERM WILL BE DETERMINING SEVERE
WEATHER CHANCES FOR THU...AND TIMING ROUNDS OF RAIN THROUGH THE AREA
THROUGH THU.
WE ARE SEEING A COUPLE OF AREAS OF RAIN SHOWERS MOVING THROUGH THE
AREA EARLY THIS MORNING. THESE RAIN SHOWERS ARE INSIGNIFICANT AS THE
MUCH BETTER MOISTURE REMAINS WELL SOUTH OF THE AREA SOUTH OF THE
COLD FRONT THAT DROPPED THROUGH THE AREA LAST EVENING. THE RAIN
SHOWERS REMAIN ASSOCIATED WITH A RRQ OF A 130 KNOT UPPER JET STREAK
THAT IS LEADING TO SOME MID LEVEL FGEN PROCESSES OVER THE AREA. WE
EXPECT MOST OF THIS TO BE GONE BY 12Z THIS MORNING.
AFTER A BREAK FOR MOST OF THE DAY TODAY...WE WILL SEE PCPN MOVE BACK
IN/DEVELOP OVER THE AREA BEGINNING TOWARD MIDNIGHT TONIGHT. THIS
PCPN WHICH SHOULD BE ALMOST ALL RAIN PER FCST SOUNDINGS WILL BE A
BIT MORE ROBUST. WE WILL SEE AN UPPER WAVE MOVE INTO THE AREA ON THE
SW FLOW ALOFT. THIS WAVE WILL HAVE BETTER SUPPORT AS THE LLJ WILL BE
AIMED CLOSER TO THE AREA BRINGING BETTER MOISTURE TO THE AREA. LATER
ON TONIGHT...THUNDER WILL BECOME POSSIBLE AS SUFFICIENT ELEVATED
INSTABILITY MOVES UP TO JUST SOUTH OF I-96. THE ELEVATED NATURE OF
THE STORMS WILL KEEP THE SEVERE THREAT FAIRLY LOW.
WE WILL HAVE A SIMILAR SET UP FOR THE WED/WED NIGHT TIME FRAME. WE
SHOULD SEE A BREAK FOR MOST OF THE AREA ON WED AS THE LLJ/MOISTURE
TRANSPORT CORE SHIFTS EAST. YET ANOTHER UPPER WAVE AND ASSOCIATED
LLJ/MOISTURE TRANSPORT AREA WILL MOVE IN ACROSS THE AREA FOR WED
NIGHT. THERE WILL BE A BETTER THREAT FOR STORMS ACROSS THE ENTIRE
CWFA AS A PLUME OF BETTER ELEVATED INSTABILITY MOVES IN. SEVERE WX
THREAT IS STILL LOW THROUGH WED NIGHT WITH THE INSTABILITY BEING
ELEVATED AND FCST SOUNDINGS INDICATING A LOWER THREAT FOR ALL OF THE
THREATS.
THU WILL BE THE DAY THAT PORTIONS OF THE AREA WILL SEE THE BEST CHC
FOR SOME SEVERE WX. WE WILL SEE THE MAIN LONG WAVE TROUGH ACROSS THE
WRN STATES LIFT NE TOWARD THE UPPER MIDWEST. THIS WILL LIFT THE
FRONT BACK NORTH ACROSS AT LEAST A PORTION OF THE AREA. HOW FAR
NORTH THE FRONT GOES WILL MAKE A BIG DIFFERENCE IN TEMPS AND SEVERE
WX THREAT WITH QUITE A TEMP GRADIENT ACROSS THE FRONT.
WE ARE TENDING TO THINK THE FRONT WILL LIFT TO ABOUT I-96 OR JUST
NORTH AS SOME OF THE MODELS SEEM TO BE OVERDEVELOPING THE SFC LOW
WITH THIS SYSTEM DUE TO EARLIER CONVECTION. THE WARM SECTOR COULD
SEE TEMPS GET INTO THE 70S WITH DEW POINTS POSSIBLY GETTING WELL
INTO THE 50S. THIS WOULD GENERATE SOME VALUES OF CAPE OVER 1000
J/KG. THE WARM FRONT WOULD BE A CONCERN WITH SOME DECENT DIRECTIONAL
SHEAR AS ONE WOULD EXPECT. SOME LARGE HAIL AND DAMAGING WINDS WOULD
BE POSSIBLE IN THE WARM SECTOR WITH FAIRLY HEALTHY CAPE IN THE -10
TO -30C LAYER AND UNIDIRECTIONAL WINDS. RAIN EARLIER ON MAY LIMIT
INSTABILITY SOME.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 AM EDT TUE APR 7 2015
THE LONG TERM LOOKS WET AT THE BEGINNING AND END BUT DRY OVER MUCH
OF THE WEEKEND.
WE/RE GOING TO HANG ONTO THE POSSIBILITY OF THUNDERSTORMS THURSDAY
NIGHT. THE GFS REMAINS SLOWER THAN THE ECMWF WHICH ALREADY MOVES LOW
PRESSURE OVER THE CENTRAL CWA BY 00Z FRIDAY. MEANWHILE THE GFS STILL
HAS THE LOW OVER EASTERN IOWA AND THE CWA IN THE WARM SECTOR. IF THE
ECMWF IS CORRECT...TSRA CHANCES WOULD BE LOWER THAN IF THE SLOWER
GFS VERIFIES. BOTH MODELS CLEAR THE TRAILING COLD FRONT BY FRIDAY
MORNING WHICH MEANS WE/LL DRY OUT FRIDAY LEADING TO SUNNY WEATHER
SATURDAY AND SUNDAY.
THE NEXT SIGNIFICANT WEATHER WILL BE A SOUTHERN STREAM LOW THAT
MOVES NORTHEAST FROM TEXAS LATE SUNDAY NIGHT AND MONDAY. THE GULF
LOOKS TO BE WIDE OPEN SO MOISTURE AVAILABILITY SHOULDN/T BE A
PROBLEM ESPECIALLY GIVEN THE 60+ KT LLJ. THIS LOOKS MOSTLY LIKE A
RAIN EVENT AS INSTABILITY APPEARS LIMITED.
TEMPS IN THE MID 50S FRIDAY WILL WARM TO THE MID 60S BY SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 745 AM EDT TUE APR 7 2015
RADAR SHOWS LIGHT SHOWERS INCREASING OVER SOUTHWEST LOWER
MICHGIAN. SHOWERS WILL REMAIN IN THE VICINITY OF THE TAF SITES
THIS MORNING BUT LIKELY WON/T RESTRICT VISIBILITIES.
NORTHEAST WINDS HAVE ADVECTED IFR/MVFR CIGS FROM SAGINAW BAY INTO
LANSING AND JACKSON. IT/S POSSIBLE THAT WE/LL SEE THESE CIGS
BOUNCE AROUND A BIT...AS LANSING HAS JUST SCATTERED OUT. IFR CIGS
SHOULD BE A THREAT UNTIL WINDS VEER MORE TO THE EAST RATHER THAN
NORTHEAST AND TAKE THE LAKE OUT OF PLAY.
&&
.MARINE...
ISSUED AT 329 AM EDT TUE APR 7 2015
WE WILL BE LEAVING THE SMALL CRAFT ADVISORY AS IS WITH THIS FCST
PACKAGE. A FAIRLY STIFF E/NE GRADIENT WILL REMAIN IN PLACE THROUGH
TODAY AND INTO WED MORNING. WAVES WILL NOT BE TOO SIGNIFICANT ON
THIS SIDE OF THE LAKE WITH THE OFFSHORE COMPONENT.
&&
.HYDROLOGY...
ISSUED AT 1210 PM EDT TUE APR 7 2015
RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING
NEAR TO A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY SLOWLY
FALLING... BUT RISES IN RIVER LEVELS DUE TO RAINFALL ARE EXPECTED
LATER THIS WEEK. 1 TO 2 INCHES OF WIDESPREAD RAINFALL IS POSSIBLE
OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER
RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. IN
GENERAL...SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED
WEDNESDAY NIGHT INTO FRIDAY. PONDING OF WATER AND URBAN AND SMALL
STREAM FLOODING IS POSSIBLE... THOUGH RIVERS SHOULD REMAIN MOSTLY
WITHIN THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...99
AVIATION...04
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1142 AM EDT TUE APR 7 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 329 AM EDT TUE APR 7 2015
THE AREA WILL SEE A RELATIVELY WET PERIOD THROUGH MOST OF THE REST
OF THIS WEEK. A STALLED OUT FRONTAL SYSTEM WILL REMAIN IN THE
REGION. THE AREA WILL BE ON THE COOL NORTH SIDE OF THIS FRONT
THROUGH WEDNESDAY. ROUNDS OF SHOWERS AND EVENTUALLY STORMS CAN BE
EXPECTED. THE FRONT WILL LIFT NORTH OF THE AREA ON THURSDAY AND
BRING WARMER AIR INTO THE AREA. STORMS WILL BECOME MORE LIKELY ON
THURSDAY WITH A THREAT FOR SOME SEVERE WEATHER POSSIBLE DOWN SOUTH.
CONDITIONS WILL QUIET DOWN THEN FOR THE END OF THE WORK WEEK AND
NEXT WEEKEND AS THE ENTIRE FRONTAL SYSTEM PUSHES OUT OF THE AREA.
&&
.UPDATE...
ISSUED AT 1142 AM EDT TUE APR 7 2015
BEST COVERAGE OF SCATTERED RAIN SHOWERS THIS AFTERNOON SHOULD BE
SOUTH OF I-96 CLOSER TO THE H8 BAROCLINIC ZONE. LATEST HRRR IS
FAVORING THE AREA EAST AND SOUTH OF A LINE FROM AZO TO LAN.
FARTHER NORTH AND WEST... MAINLY ISOLATED COVERAGE OF SHOWERS AT
BEST. H5 PROGS SHOW SEVERAL VORTICITY MAXIMA EMBEDDED IN ZONAL
FLOW ALOFT SO AM RELUCTANT TO GO COMPLETELY DRY IN THE NRN CWFA
AFTER 18Z. TEMPS WILL STRUGGLE TO GET OUT OF THE 40S THIS AFTEROON
WITH CLOUDS AND BRISK EAST FLOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 329 AM EDT TUE APR 7 2015
OUR MAIN CHALLENGES IN THE SHORT TERM WILL BE DETERMINING SEVERE
WEATHER CHANCES FOR THU...AND TIMING ROUNDS OF RAIN THROUGH THE AREA
THROUGH THU.
WE ARE SEEING A COUPLE OF AREAS OF RAIN SHOWERS MOVING THROUGH THE
AREA EARLY THIS MORNING. THESE RAIN SHOWERS ARE INSIGNIFICANT AS THE
MUCH BETTER MOISTURE REMAINS WELL SOUTH OF THE AREA SOUTH OF THE
COLD FRONT THAT DROPPED THROUGH THE AREA LAST EVENING. THE RAIN
SHOWERS REMAIN ASSOCIATED WITH A RRQ OF A 130 KNOT UPPER JET STREAK
THAT IS LEADING TO SOME MID LEVEL FGEN PROCESSES OVER THE AREA. WE
EXPECT MOST OF THIS TO BE GONE BY 12Z THIS MORNING.
AFTER A BREAK FOR MOST OF THE DAY TODAY...WE WILL SEE PCPN MOVE BACK
IN/DEVELOP OVER THE AREA BEGINNING TOWARD MIDNIGHT TONIGHT. THIS
PCPN WHICH SHOULD BE ALMOST ALL RAIN PER FCST SOUNDINGS WILL BE A
BIT MORE ROBUST. WE WILL SEE AN UPPER WAVE MOVE INTO THE AREA ON THE
SW FLOW ALOFT. THIS WAVE WILL HAVE BETTER SUPPORT AS THE LLJ WILL BE
AIMED CLOSER TO THE AREA BRINGING BETTER MOISTURE TO THE AREA. LATER
ON TONIGHT...THUNDER WILL BECOME POSSIBLE AS SUFFICIENT ELEVATED
INSTABILITY MOVES UP TO JUST SOUTH OF I-96. THE ELEVATED NATURE OF
THE STORMS WILL KEEP THE SEVERE THREAT FAIRLY LOW.
WE WILL HAVE A SIMILAR SET UP FOR THE WED/WED NIGHT TIME FRAME. WE
SHOULD SEE A BREAK FOR MOST OF THE AREA ON WED AS THE LLJ/MOISTURE
TRANSPORT CORE SHIFTS EAST. YET ANOTHER UPPER WAVE AND ASSOCIATED
LLJ/MOISTURE TRANSPORT AREA WILL MOVE IN ACROSS THE AREA FOR WED
NIGHT. THERE WILL BE A BETTER THREAT FOR STORMS ACROSS THE ENTIRE
CWFA AS A PLUME OF BETTER ELEVATED INSTABILITY MOVES IN. SEVERE WX
THREAT IS STILL LOW THROUGH WED NIGHT WITH THE INSTABILITY BEING
ELEVATED AND FCST SOUNDINGS INDICATING A LOWER THREAT FOR ALL OF THE
THREATS.
THU WILL BE THE DAY THAT PORTIONS OF THE AREA WILL SEE THE BEST CHC
FOR SOME SEVERE WX. WE WILL SEE THE MAIN LONG WAVE TROUGH ACROSS THE
WRN STATES LIFT NE TOWARD THE UPPER MIDWEST. THIS WILL LIFT THE
FRONT BACK NORTH ACROSS AT LEAST A PORTION OF THE AREA. HOW FAR
NORTH THE FRONT GOES WILL MAKE A BIG DIFFERENCE IN TEMPS AND SEVERE
WX THREAT WITH QUITE A TEMP GRADIENT ACROSS THE FRONT.
WE ARE TENDING TO THINK THE FRONT WILL LIFT TO ABOUT I-96 OR JUST
NORTH AS SOME OF THE MODELS SEEM TO BE OVERDEVELOPING THE SFC LOW
WITH THIS SYSTEM DUE TO EARLIER CONVECTION. THE WARM SECTOR COULD
SEE TEMPS GET INTO THE 70S WITH DEW POINTS POSSIBLY GETTING WELL
INTO THE 50S. THIS WOULD GENERATE SOME VALUES OF CAPE OVER 1000
J/KG. THE WARM FRONT WOULD BE A CONCERN WITH SOME DECENT DIRECTIONAL
SHEAR AS ONE WOULD EXPECT. SOME LARGE HAIL AND DAMAGING WINDS WOULD
BE POSSIBLE IN THE WARM SECTOR WITH FAIRLY HEALTHY CAPE IN THE -10
TO -30C LAYER AND UNIDIRECTIONAL WINDS. RAIN EARLIER ON MAY LIMIT
INSTABILITY SOME.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 AM EDT TUE APR 7 2015
THE LONG TERM LOOKS WET AT THE BEGINNING AND END BUT DRY OVER MUCH
OF THE WEEKEND.
WE/RE GOING TO HANG ONTO THE POSSIBILITY OF THUNDERSTORMS THURSDAY
NIGHT. THE GFS REMAINS SLOWER THAN THE ECMWF WHICH ALREADY MOVES LOW
PRESSURE OVER THE CENTRAL CWA BY 00Z FRIDAY. MEANWHILE THE GFS STILL
HAS THE LOW OVER EASTERN IOWA AND THE CWA IN THE WARM SECTOR. IF THE
ECMWF IS CORRECT...TSRA CHANCES WOULD BE LOWER THAN IF THE SLOWER
GFS VERIFIES. BOTH MODELS CLEAR THE TRAILING COLD FRONT BY FRIDAY
MORNING WHICH MEANS WE/LL DRY OUT FRIDAY LEADING TO SUNNY WEATHER
SATURDAY AND SUNDAY.
THE NEXT SIGNIFICANT WEATHER WILL BE A SOUTHERN STREAM LOW THAT
MOVES NORTHEAST FROM TEXAS LATE SUNDAY NIGHT AND MONDAY. THE GULF
LOOKS TO BE WIDE OPEN SO MOISTURE AVAILABILITY SHOULDN/T BE A
PROBLEM ESPECIALLY GIVEN THE 60+ KT LLJ. THIS LOOKS MOSTLY LIKE A
RAIN EVENT AS INSTABILITY APPEARS LIMITED.
TEMPS IN THE MID 50S FRIDAY WILL WARM TO THE MID 60S BY SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 745 AM EDT TUE APR 7 2015
RADAR SHOWS LIGHT SHOWERS INCREASING OVER SOUTHWEST LOWER
MICHGIAN. SHOWERS WILL REMAIN IN THE VICINITY OF THE TAF SITES
THIS MORNING BUT LIKELY WON/T RESTRICT VISIBILITIES.
NORTHEAST WINDS HAVE ADVECTED IFR/MVFR CIGS FROM SAGINAW BAY INTO
LANSING AND JACKSON. IT/S POSSIBLE THAT WE/LL SEE THESE CIGS
BOUNCE AROUND A BIT...AS LANSING HAS JUST SCATTERED OUT. IFR CIGS
SHOULD BE A THREAT UNTIL WINDS VEER MORE TO THE EAST RATHER THAN
NORTHEAST AND TAKE THE LAKE OUT OF PLAY.
&&
.MARINE...
ISSUED AT 329 AM EDT TUE APR 7 2015
WE WILL BE LEAVING THE SMALL CRAFT ADVISORY AS IS WITH THIS FCST
PACKAGE. A FAIRLY STIFF E/NE GRADIENT WILL REMAIN IN PLACE THROUGH
TODAY AND INTO WED MORNING. WAVES WILL NOT BE TOO SIGNIFICANT ON
THIS SIDE OF THE LAKE WITH THE OFFSHORE COMPONENT.
&&
.HYDROLOGY...
ISSUED AT 221 PM EDT MON APR 6 2015
RIVERS AND STREAMS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING A
LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY SLOWLY
FALLING...BUT RISES IN RIVER LEVELS DUE TO RAINFALL ARE EXPECTED
LATER THIS WEEK. 1 TO 2 INCHES OF WIDESPREAD RAINFALL IS POSSIBLE
OVER THE NEXT 7 DAYS...WITH THE POTENTIAL FOR SEVERAL INCHES IF
THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL
ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY NIGHT
INTO FRIDAY. STRONGER STORMS ARE CERTAINLY POSSIBLE DURING THIS
TIMEFRAME...SO THERE IS A RISK FOR LOCALLY HEAVY RAINFALL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...99
AVIATION...04
HYDROLOGY...EBW
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
737 AM EDT TUE APR 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE APR 7 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A
CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN
QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE
W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE
CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS
ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE
DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR
DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF
LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO
THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS.
HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL
RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW
ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO
THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST
OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS
LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS
RDG AND THE TROF ALONG THE W COAST.
MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY
THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS
FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS
AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI.
TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ
OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR
CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL
THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE
DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR
SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI
THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL
DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS
AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY
FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S.
TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV
NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL
CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT
GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE
WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT...
ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR
JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE
ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL
CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL
FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH
OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE
FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE
GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE
SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS
H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES
MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN
EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE
WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE
NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A
CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE
GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE
COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN
AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING
THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT
CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND
VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY
OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT
OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC
COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET
OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW
FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE
POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM EDT TUE APR 7 2015
THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH
PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL
TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH
WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS
POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE.
TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE
PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION
WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING.
THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND
WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF
PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE
START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY
LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE
U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL
MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB
FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE
DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE
GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF
THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW
SLIGHT CHANCE POPS FOR THE DRIZZLE.
ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF
THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING
THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES
THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO
WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE
TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING
NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE
U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST
WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS
LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF
LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH
900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST
FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH
LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING
RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST
COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES
ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD
SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE
CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND
KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE
IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF
ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS
FREEZING RAIN THREAT IN THE HWO.
AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY
AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE
SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN
LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION
OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE
AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE
LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF
THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN
DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE
MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS
AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME.
AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE
FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE)
WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK
MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF
REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS
TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE
NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS
PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY
FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND
THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST.
WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN
SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF
A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP
IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER
THE NEXT SEVERAL SHIFTS.
THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT
AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES
EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR
BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT
LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH
MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON
SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR
TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S
OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW
WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING
ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA
SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE
THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW
INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 736 AM EDT TUE APR 7 2015
STEADY ENE WIND ON THE SRN FLANK OF HI PRES RIDGE EXTENDING ACROSS
NW ONTARIO WILL ADVECT LLVL DRY AIR INTO UPR MI THRU THIS EVNG...
RESULTING IN VFR CONDITIONS DESPITE CONSIDERABLE MID/HI CLDS. AS A
DISTURBANCE MOVES INTO THE GREAT LKS TNGT...SOME LIGHT PCPN MAY
IMPACT IWD AND SAW OVERNGT. IF THE LLVL DRY AIR CAN BE OVERCOME...
MVFR CONDITIONS MAY IMPACT SAW AND ESPECIALLY IWD...WHICH WL BE
FARTHER FM THE CORE OF THE DRY AIR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT TUE APR 7 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW
ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO
THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL
PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER
WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN
NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN
THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO
THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON
WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS
TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR
LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU
NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EDT TUE APR 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE APR 7 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A
CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN
QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE
W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE
CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS
ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE
DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR
DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF
LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO
THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS.
HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL
RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW
ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO
THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST
OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS
LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS
RDG AND THE TROF ALONG THE W COAST.
MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY
THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS
FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS
AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI.
TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ
OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR
CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL
THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE
DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR
SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI
THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL
DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS
AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY
FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S.
TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV
NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL
CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT
GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE
WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT...
ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR
JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE
ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL
CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL
FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH
OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE
FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE
GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE
SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS
H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES
MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN
EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE
WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE
NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A
CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE
GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE
COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN
AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING
THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT
CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND
VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY
OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT
OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC
COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET
OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW
FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE
POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM EDT TUE APR 7 2015
THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH
PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL
TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH
WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS
POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE.
TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE
PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION
WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING.
THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND
WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF
PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE
START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY
LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE
U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL
MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB
FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE
DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE
GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF
THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW
SLIGHT CHANCE POPS FOR THE DRIZZLE.
ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF
THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING
THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES
THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO
WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE
TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING
NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE
U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST
WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS
LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF
LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH
900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST
FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH
LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING
RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST
COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES
ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD
SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE
CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND
KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE
IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF
ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS
FREEZING RAIN THREAT IN THE HWO.
AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY
AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE
SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN
LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION
OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE
AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE
LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF
THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN
DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE
MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS
AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME.
AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE
FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE)
WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK
MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF
REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS
TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE
NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS
PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY
FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND
THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST.
WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN
SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF
A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP
IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER
THE NEXT SEVERAL SHIFTS.
THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT
AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES
EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR
BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT
LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH
MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON
SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR
TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S
OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW
WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING
ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA
SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE
THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW
INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 120 AM EDT TUE APR 7 2015
HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL
DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR
CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE
CONSIDERABLE MID/HI CLDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT TUE APR 7 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW
ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO
THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL
PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER
WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN
NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN
THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO
THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON
WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS
TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR
LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU
NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT TUE APR 7 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 429 PM EDT MON APR 6 2015(TODAY AND TONIGHT)
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CONFLUENT WESTERLY FLOW
ACROSS THE UPPER LAKES BTWN NRN BRANCH TROF OVER ERN CANADA AND SRN
BRANCH RIDGE OVER THE CNTRL CONUS WHICH IS DOWNSTREAM OF A STRONG
TROF ALONG/JUST OFF THE W COAST. SNOW THAT AFFECTED MUCH OF SRN
UPPER MI LAST NIGHT/EARLIER TODAY HAS LARGELY ENDED AS SUBTLE
SHORTWAVE/STRONGER RIGHT ENTRANCE FORCING FROM UPPER JET ALONG AND
LOW/MID LEVEL FRONTOGENESIS HAVE SHIFTED E. TO THE N...A DRY AIR
MASS ASSOCIATED WITH SFC HIGH PRES RIDGING FROM
SASKATCHEWAN/MANITOBA INTO NRN ONTARIO/NRN LAKE SUPERIOR CONTINUES
TO FEED TO THE S AND W.
RIGHT ENTRANCE OF THE UPPER JET WITHIN THE CONFLUENCE ZONE REMAINS
OVER THE UPPER MISSISSIPPI VALLEY/UPPER LAKES REGION TONIGHT. THERE
ARE SOME HINTS THAT ANOTHER SUBTLE SHORTWAVE AND RIBBON OF
FRONTOGENESIS WILL STREAK ACROSS FAR SCNTRL UPPER MI THIS EVENING.
THIS MAY LEAD TO ANOTHER BAND OF SNOW STREAKING ACROSS MAINLY
MENOMINEE COUNTY. LATEST RAP/HRRR SUPPORT THIS IDEA AS DO THE 12Z
NAM AND HIRES WRF-ARW/NMM TO VARYING DEGREES. RADAR TRENDS UPSTREAM
LEND SOME SUPPORT AS WELL. WILL SHOW AN UPTICK IN POPS ACROSS THE
SRN HALF OF MENOMINEE COUNTY THIS EVENING WITH SNOW ACCUMULATIONS
PROBABLY LESS THAN 1 INCH. EXPECT A SHARP CUTOFF TO THE SNOW FARTHER
N AS DRIER AIR FROM THE HIGH PRES RIDGE TO THE N AND NE CONTINUES TO
ADVECT S AND W. WILL CARRY SCHC POPS AS FAR N AS US-2 FROM IRON
RIVER TO ESCANABA. SNOW WILL END OVERNIGHT. EXPECT MIN TEMPS IN THE
20S ACROSS THE AREA...THOUGH SOME TEENS ARE POSSIBLE IN THE USUAL
COLDER SPOTS ACROSS THE N AND E AS CLOUDS MAY THIN ENOUGH TO AID
COOLING OVERNIGHT.
QUIET DAY EXPECTED ON TUE AS ALL MODEL GUIDANCE IS IN GOOD AGREEMENT
ON DRY AIR DOMINATING IN THE LOWER LEVELS. FAVORED THE LOWER SIDE OF
GUIDANCE FOR TEMPS WITH THE IDEA THAT FAIRLY THICK HIGHER CLOUDS
WILL PREVENT SIGNIFICANT WARMING. E TO NE WIND ALSO ARGUES FOR THE
COOLER SIDE OF GUIDANCE...ESPECIALLY SO FROM THE KEWEENAW ACROSS THE
NCNTRL AND S OF KESC NEAR LAKE MI. LOW TO MID 30S SHOULD BE THE RULE
IN THOSE AREAS. ELSEWHERE...TEMPS SHOULD RISE TO AROUND 40F...
HIGHEST WHERE E TO NE WINDS DOWNSLOPE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM EDT TUE APR 7 2015
THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH
PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL
TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH
WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS
POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE.
TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE
PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION
WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING.
THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND
WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF
PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE
START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY
LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE
U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL
MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB
FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE
DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE
GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF
THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW
SLIGHT CHANCE POPS FOR THE DRIZZLE.
ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF
THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING
THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES
THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO
WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE
TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING
NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE
U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST
WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS
LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF
LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH
900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST
FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH
LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING
RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST
COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES
ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD
SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE
CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND
KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE
IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF
ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS
FREEZING RAIN THREAT IN THE HWO.
AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY
AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE
SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN
LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION
OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE
AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE
LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF
THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN
DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE
MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS
AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME.
AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE
FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE)
WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK
MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF
REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS
TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE
NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS
PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY
FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND
THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST.
WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN
SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF
A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP
IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER
THE NEXT SEVERAL SHIFTS.
THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT
AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES
EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR
BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT
LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH
MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON
SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR
TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S
OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW
WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING
ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA
SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE
THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW
INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 120 AM EDT TUE APR 7 2015
HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL
DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR
CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE
CONSIDERABLE MID/HI CLDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT MON APR 6 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE ACROSS
NRN ONTARIO INTO QUEBEC THRU WED MORNING AND A WARM FRONT THAT WILL
REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE
WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE
STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE
ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE
THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT
LATER TONIGHT AND CONTINUE THRU TUE NIGHT. EXPECT SOME GALE FORCE
GUSTS TUE AFTN/EVENING. E TO NE WINDS...MOSTLY 15-25KT...WILL THEN
CONTINUE THRU WED AND ON INTO THU AS LOW PRESSURE LIFTS NE FROM THE
CENTRAL PLAINS TO THE GREAT LAKES REGION. AT THIS TIME...IT DOES NOT
APPEAR THAT THE LOW WILL BE STRONG ENOUGH TO RESULT IN GALES AS IT
APPROACHES AND THEN DEPARTS. WINDS WILL BACK AROUND TO THE N AND NW
THU NIGHT AND FRI AS THE LOW EXITS TO THE NE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT TUE APR 7 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 429 PM EDT MON APR 6 2015(TODAY AND TONIGHT)
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CONFLUENT WESTERLY FLOW
ACROSS THE UPPER LAKES BTWN NRN BRANCH TROF OVER ERN CANADA AND SRN
BRANCH RIDGE OVER THE CNTRL CONUS WHICH IS DOWNSTREAM OF A STRONG
TROF ALONG/JUST OFF THE W COAST. SNOW THAT AFFECTED MUCH OF SRN
UPPER MI LAST NIGHT/EARLIER TODAY HAS LARGELY ENDED AS SUBTLE
SHORTWAVE/STRONGER RIGHT ENTRANCE FORCING FROM UPPER JET ALONG AND
LOW/MID LEVEL FRONTOGENESIS HAVE SHIFTED E. TO THE N...A DRY AIR
MASS ASSOCIATED WITH SFC HIGH PRES RIDGING FROM
SASKATCHEWAN/MANITOBA INTO NRN ONTARIO/NRN LAKE SUPERIOR CONTINUES
TO FEED TO THE S AND W.
RIGHT ENTRANCE OF THE UPPER JET WITHIN THE CONFLUENCE ZONE REMAINS
OVER THE UPPER MISSISSIPPI VALLEY/UPPER LAKES REGION TONIGHT. THERE
ARE SOME HINTS THAT ANOTHER SUBTLE SHORTWAVE AND RIBBON OF
FRONTOGENESIS WILL STREAK ACROSS FAR SCNTRL UPPER MI THIS EVENING.
THIS MAY LEAD TO ANOTHER BAND OF SNOW STREAKING ACROSS MAINLY
MENOMINEE COUNTY. LATEST RAP/HRRR SUPPORT THIS IDEA AS DO THE 12Z
NAM AND HIRES WRF-ARW/NMM TO VARYING DEGREES. RADAR TRENDS UPSTREAM
LEND SOME SUPPORT AS WELL. WILL SHOW AN UPTICK IN POPS ACROSS THE
SRN HALF OF MENOMINEE COUNTY THIS EVENING WITH SNOW ACCUMULATIONS
PROBABLY LESS THAN 1 INCH. EXPECT A SHARP CUTOFF TO THE SNOW FARTHER
N AS DRIER AIR FROM THE HIGH PRES RIDGE TO THE N AND NE CONTINUES TO
ADVECT S AND W. WILL CARRY SCHC POPS AS FAR N AS US-2 FROM IRON
RIVER TO ESCANABA. SNOW WILL END OVERNIGHT. EXPECT MIN TEMPS IN THE
20S ACROSS THE AREA...THOUGH SOME TEENS ARE POSSIBLE IN THE USUAL
COLDER SPOTS ACROSS THE N AND E AS CLOUDS MAY THIN ENOUGH TO AID
COOLING OVERNIGHT.
QUIET DAY EXPECTED ON TUE AS ALL MODEL GUIDANCE IS IN GOOD AGREEMENT
ON DRY AIR DOMINATING IN THE LOWER LEVELS. FAVORED THE LOWER SIDE OF
GUIDANCE FOR TEMPS WITH THE IDEA THAT FAIRLY THICK HIGHER CLOUDS
WILL PREVENT SIGNIFICANT WARMING. E TO NE WIND ALSO ARGUES FOR THE
COOLER SIDE OF GUIDANCE...ESPECIALLY SO FROM THE KEWEENAW ACROSS THE
NCNTRL AND S OF KESC NEAR LAKE MI. LOW TO MID 30S SHOULD BE THE RULE
IN THOSE AREAS. ELSEWHERE...TEMPS SHOULD RISE TO AROUND 40F...
HIGHEST WHERE E TO NE WINDS DOWNSLOPE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 356 PM EDT MON APR 6 2015
THE LONG TERM FORECAST CONTINUES TO BE A CONTINUALLY FRUSTRATING
EXPERIENCE WHEN ATTEMPTING TO PIN DOWN THE FINER DETAILS OF THE
FORECAST. ESPECIALLY WITH THE UPPER GREAT LAKES REGION ON THE
NORTHERN EDGE OF THE DISTURBANCES AND HAVING THERMAL PROFILES THAT
SUPPORT MIXED PRECIPITATION AND FREEZING RAIN.
TUE NIGHT INTO WED MORNING A SHORTWAVE LOOKS TO MOVE S OF THE AREA
OR OVER THE SRN CWA. STILL LOTS OF UNCERTAINTY WITH TRACK OF THE
SHORTWAVE...LOCATION AND AMOUNT OF QPF...AND TEMPERATURE PROFILES.
THEREFORE...PRECIP AMOUNT AND TYPE ARE VERY MUCH IN QUESTION AS
WELL. IF THE COLDER GFS/ECMWF SOLUTION VERIFY...ANY PRECIP THAT
FALLS WOULD BE MORE SNOW TRANSITIONING TO FREEZING DRIZZLE AS MID
LEVEL MOISTURE CUTS OUT AND E WINDS FORCE ONSHORE/UPSLOPE PRECIP
INTO SCENTRAL UPPER MI. THE WARMER ALOFT NAM AND GEM WOULD RESULT IN
MORE FREEZING RAIN TURNING TO FREEZING DRIZZLE. THIS BEING
SAID...THE SNOW OR RAIN PORTION IS STILL QUITE UNCERTAIN. FREEZING
DRIZZLE WED MORNING SHOULD BE LIGHT AS LOW LEVEL MIXING SHOULD ALLOW
NEAR SFC LAYERS TO DRY OUT SOME.
WED AFTERNOON/EVENING LOOKS DRY INLAND...BUT COULD SEE DRIZZLE IN
UPSLOPE AREAS FROM THE E WINDS...MAINLY CENTRAL UPPER MI AND THE
KEWEENAW.
A STRONGER SHORTWAVE AND SFC LOW WILL EJECT OUT OF THE CENTRAL
PLAINS WED NIGHT...BRINGING A SURGE OF WARM AIR OVER THE CWA. MODELS
DO NOT AGREE WELL ON THE FINER DETAILS AND DO NOT HAVE GOOD RUN TO
RUN CONTINUITY. MAIN CONCERN EARLY IN THE EVENT IS WITH FREEZING
RAIN POTENTIAL WED NIGHT INTO THU MORNING. MID LEVEL TEMPS WILL
EASILY SUPPORT ALL LIQUID PRECIP...WITH SFC TEMPS DETERMINING
FREEZING RAIN POTENTIAL AS LOW LEVEL COLD AIR WILL BE TOO SHALLOW
FOR SLEET. FREEZING RAIN DOES LOOK LIKE A STRONG POSSIBILITY DURING
THIS TIME...BUT AMOUNTS OF QPF ARE STILL VERY MUCH IN QUESTION. IT
LOOKS AS THOUGH THE SYSTEM WILL PHASE WITH A NRN STREAM SYSTEM LATER
THU INTO FRI...BRINGING COLDER AIR IN FROM THE WNW LATE THU INTO
FRI. THIS FORECAST PERIOD IS EVEN MORE IN QUESTION AS MODELS
STRUGGLE WITH PHASING. IT DOES APPEAR PRECIP IS LIKELY...THE
UNCERTAINTY HAS MORE TO DO WITH PTYPE AND PRECIP AMOUNTS...FOR WHICH
SMALLER SCALE DETAILS WILL BE CRUCIAL. GIVEN THE GENERAL CONSENSUS
IDEA...THINK THAT PRECIP WILL TRANSITION FROM RAIN TO FREEZING RAIN
TO SNOW OVER WRN UPPER MI THU EVENING/NIGHT...WITH SIGNIFICANT
AMOUNTS OF EACH POSSIBLE BUT NOT CERTAIN. RAIN SHOULD TRANSITION TO
MORE OF A RAIN/SNOW MIX OVER THE CENTRAL THU NIGHT. THE ECMWF MOVES
THE PRECIP OUT OF THE AREA FRI EVENING WHILE THE GFS LINGERS PRECIP
INTO SAT MORNING. GIVEN POTENTIAL FOR FREEZING RAIN ACCUMULATION WED
NIGHT/THU MORNING AND FREEZING RAIN/SNOW POTENTIAL THU EVENING/NIGHT
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
IT LOOKS LIKE SFC HIGH PRESSURE AND UPPER RIDGING SHIFT ACROSS THE
CWA OVER THE WEEKEND...WITH A WARM UP POSSIBLE AS THE HIGH SHIFTS E
AND A TROUGH MOVES TOWARD THE AREA FROM THE W. WILL JUST RUN WITH A
CONSENSU OF GUIDANCE FOR SAT-MON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 120 AM EDT TUE APR 7 2015
HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL
DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR
CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE
CONSIDERABLE MID/HI CLDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT MON APR 6 2015
WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE ACROSS
NRN ONTARIO INTO QUEBEC THRU WED MORNING AND A WARM FRONT THAT WILL
REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE
WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE
STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE
ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE
THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT
LATER TONIGHT AND CONTINUE THRU TUE NIGHT. EXPECT SOME GALE FORCE
GUSTS TUE AFTN/EVENING. E TO NE WINDS...MOSTLY 15-25KT...WILL THEN
CONTINUE THRU WED AND ON INTO THU AS LOW PRESSURE LIFTS NE FROM THE
CENTRAL PLAINS TO THE GREAT LAKES REGION. AT THIS TIME...IT DOES NOT
APPEAR THAT THE LOW WILL BE STRONG ENOUGH TO RESULT IN GALES AS IT
APPROACHES AND THEN DEPARTS. WINDS WILL BACK AROUND TO THE N AND NW
THU NIGHT AND FRI AS THE LOW EXITS TO THE NE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
337 PM CDT TUE APR 7 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE APR 7 2015
CURRENT CONDITIONS SYNOPSIS...
CLUSTER OF SHOWERS AND EMBEDDED THUNDERSTORMS CURRENTLY MOVING
THROUGH THE SOUTHERN PORTION OF THE AREA ALONG THE NORTHERN
PERIPHERY OF THE INSTABILITY... WITH A NOTABLE GRADIENT IN MUCAPE
JUMPING FROM 0 TO 500 J/KG SOUTH OF THE BORDER. DEEP LAYER SHEAR IS
STRONG... AND ONE STORM DID BRIEFLY SHOW SOME MID-LEVEL
ROTATION... AND MANAGED TO PRODUCE MARGINALLY SEVERE HAIL. THE
ACTIVITY SHOULD TRANSLATE EAST AND FOCUS MORE SOUTH AS THE
SHORTWAVE EVIDENT ON WATER VAPOR NEAR THE NEBRASKA/IOWA BORDERS
SHIFTS EAST THROUGH EARLY EVENING.
FORECAST ITEM/S/ OF CONCERN...
CHANCES FOR PCPN... SOME THUNDER... AND PERHAPS SOME MIXED PCPN INTO
TONIGHT... WITH THINGS DRYING OUT WEDNESDAY.
MODEL DISCUSSION/PREFERENCES...
PRIMARILY RELYING ON CAM GUIDANCE... PARTICULARLY HRRR AND HOPWRF
MEMBERS... WHICH HAVE A DECENT HANDLE ON CURRENT CONVECTIVE ACTIVITY
ACROSS THE AREA... BLENDING MORE TOWARD NAM/GFS SOLUTIONS ON
WEDNESDAY.
SENSIBLE WEATHER EXPECTATIONS...
EXPECT SHRA AND EMBEDDED TSRA TO IMPACT THE SOUTHERN PORTION OF THE
AREA INTO PERHAPS THE EARLY EVENING... OTHERWISE WILL SEE PCPN ON
THE NORTH SIDE OF SURFACE LOW MOVE EAST ACROSS THE AREA THROUGH THE
REMAINDER OF THE EVENING. SOME SLEET COULD MIX IN AT TIMES OVER THE
NORTH AND NORTHEAST PORTION OF THE AREA WHERE THE WARM LAYER IS A
BIT LESS DEEP. SHOULD SEE ENOUGH DRYING/SUBSIDENCE IN THE MID-LEVELS
FOR PCPN TO COME TO AN END LATER TONIGHT... WITH DRY WEATHER OTHER
THAN PERHAPS SOME PATCHY DRIZZLE THROUGH MOST OF WEDNESDAY. SOME
SHRA COULD WORK BACK INTO THE SOUTHERN PART OF THE AREA BY LATER
WEDNESDAY AS THE NEXT SHORTWAVE AND SURFACE IMPULSE ALONG THE
BAROCLINIC ZONE WORK INTO THE REGION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CDT TUE APR 7 2015
THE STORM SYSTEM OFF THE COAST OF CALIFORNIA WILL IMPACT OUR
REGION FROM WEDNESDAY NIGHT THRU EARLY FRIDAY MORNING. THE FIRST
PART OF THE STORM HAS THE POTENTIAL OF SVR WX IN THE FAR SE BASED
ON STABILITY PARAMETERS...LOW FREEZING LEVEL AND MID LEVEL LAPSE
RATES. THE BEST POTENTIAL WILL BE THURSDAY AFTERNOON FROM ALBERT
LEA...NORTHEAST TO EAU CLAIRE WISCONSIN. SEE THE LATEST SPC DAY 3
OUTLOOK.
SEVERAL FACTORS NEED TO COME TOGETHER FOR SNOWFALL TO ACCUMULATE
IN OUR CWA. FIRST...THE BEST CHC OF PRECIPITATION AND HIGHER
PRECIPITATION RATES OCCUR BETWEEN 18Z THU TO 06Z FRIDAY. THE SFC
LOW REMAINS IN A FAVORABLE TRACK FOR THE PRECIPITATION TO CHANGE
OVER TO SNOW DURING THE LATE AFTN/EVENING. HOWEVER...THERMAL
PROFILERS REMAINED UNFAVORABLE OF THIS CHANGE OVER IN OUR
CWA...WITH ONLY A SMALL AREA OF THICKNESS VALUES DROPPING TO
CRITICAL LEVELS IN EC MN/WC WI THURSDAY EVENING. THERE REMAINS A
VERY STRONG SIGNAL OF A TROWAL AND DEFORMATION ZONE DEVELOPMENT IN
EC MN/WC WI THURSDAY EVENING. AS WITH PREVIOUS DISCUSSIONS...THERE
IS A POTENTIAL OF HEAVY SNOWFALL IN A SMALL BAND IF ALL THE
WEATHER ELEMENTS COME TOGETHER. IN ADDITION...A CROSS SECTION OF
THE ATMOSPHERE FROM WC MN TO SOUTHERN WI HAS EC MN IN FAVORABLE
AREA OF CONVECTIVE STABILITY INDEX /CSI/ AND SLATEWISE
CONVECTIVE. THEREFORE...IT IS HIGHLY PROBABLE FOR SOMEWHERE IN
EASTERN MN/WESTERN WI TO SEE A HEAVY SNOWFALL EVENT THURSDAY
EVENING IF THIS TYPE OF SCENARIO DEVELOPS.
PAST THURSDAY...A COOL PERIOD WILL OCCUR FROM FRIDAY THRU
SATURDAY BEFORE SOUTHERLY FLOW BEGINS. LATE IN THE WEEKEND AND
INTO NEXT WEEK REMAIN VERY UNSETTLED AS ANOTHER STORM SYSTEM
BEGINS TO DEVELOP ACROSS THE CENTRAL U.S. WITH THIS TYPE OF
PATTERN...TEMPS MAY FLUCTUATE RAPIDLY BASED ON THE AMOUNT CLOUD
COVER AND PRECIPITATION POTENTIAL...BUT AN OVERALL MEAN IS TO
CONTINUE WITH SLIGHTLY BLW NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 330 PM CDT TUE APR 7 2015
HIGH CONFIDENCE OF WIDESPREAD RAINFALL ACROSS THE SE MPX FORECAST
AREA...WITH CIGS LOWERING THROUGHOUT THE NIGHT INTO THE IFR RANGE.
SOME IMPROVEMENT IS LIKELY WEDNESDAY AFTN BEFORE THE NEXT WAVE OF
PRECIPITATION DEVELOPS. EXPECT AN EAST TO EAST-SOUTHEAST WIND AROUND
10-15 KTS TONIGHT...BACKING TO THE E-NE BY WEDNESDAY AFTN.
KMSP...HIGH CONFIDENCE OF -SHRA LATE THIS AFTN/EARLY EVENING WITH
CIGS LOWERING. CIGS WILL LIKELY DROP TO IFR OVERNIGHT...AND SLOWLY
RISE WEDNESDAY AFTN. EXPECT AN EAST TO EAST-SOUTHEAST WIND AROUND
10-15 KTS TONIGHT...BACKING TO THE E-NE BY WEDNESDAY AFTN.
/OUTLOOK FOR KMSP/
THU...MVFR POSSIBLY IFR. RA/SN LIKELY. WINDS N 15-25 KTS.
FRI...VFR. WINDS NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...
LONG TERM...JLT
AVIATION...JLT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
818 PM CDT WED APR 8 2015
.UPDATE...A FEW SHOWERS HAVE CROPPED UP THIS EVENING BELOW THE CAP OVER SW
MS/EC LA JUST AS THE HRRR HAS INDICATED. IT IS ALSO INDICATING THAT
THEY WILL NOT LAST LONG...DIMINISHING BEFORE MIDNIGHT. LOOKING AT
HOURLY TEMPS/DEWPOINTS...TWEAKED THESE A BIT SIMILAR TO THE HRRR
SOLUTION WHICH SHOWED A GOOD SURGE OF LOW LEVEL MOISTURE AND CLOUD
COVER AFTER MIDNIGHT. THIS SHOULD RESULT IN MINS NOT QUITE AS
COOL./26/
&&
.AVIATION...VFR CIGS THIS EVENING WILL TRANSITION TO MVFR/IFR AFTER
MIDNIGHT AS LOW CLOUDS ONCE AGAIN OVERSPREAD THE AREA. WINDS
REMAINING FROM 5 TO 15 KNOTS WILL LIMIT FOG FORMATION OVER MUCH OF
THE AREA. THE EXCEPTION WILL BE NEAR MEI AND HBG WHERE THE WIND WILL
SUBSIDE ENOUGH FOR IFR/LIFR VSBYS FROM 10-14Z. AFTER 14Z...CIGS WILL
BECOME MVFR AND EVENTUALLY VFR AFTER 18Z./26/
&&
.PREV DISCUSSION... /ISSUED 417 PM CDT WED APR 8 2015/
DISCUSSION...ANOTHER WARM DAY HAS TAKEN PLACE TODAY AS TEMPERATURES
HAVE REACHED INTO THE 80S AREAWIDE...AND SOME LOCATIONS HAVE SEEN THE
MID 80S. GUSTY SOUTHERLY WINDS CONTINUE TO BRING MOISTURE INTO THE
REGION. CLOUDS WILL CONTINUE TO BE ON THE INCREASE THROUGH TONIGHT
AND INTO THURSDAY. SOME PATCHY FOG WILL BE POSSIBLE IN THE EAST AND
SOUTHEAST BUT OVERALL WIND SPEEDS SHOULD BE UP ENOUGH TO PRECLUDE TOO
MUCH FOG AND MORE IN THE WAY OF STRATUS.
THURSDAY SHOULD BE ANOTHER WARM DAY AS MOISTURE CONTINUES TO MOVE
INTO THE REGION AHEAD OF A DEVELOPING STORM SYSTEM IN THE PLAINS.
SHOWERS SHOULD BE KEPT AT BAY TOMORROW AS THE REGION WILL REMAIN
CAPPED AND HEIGHTS WILL BE HIGH. A 998MB SFC LOW WILL TRACK NORTHEAST
ACROSS THE MIDWEST INTO SOUTHERN WISCONSIN THROUGH THE DAY THURSDAY.
THIS WILL BRING A FRONT TOWARD THE REGION. BY LATER IN THE
DAY...FORCING SHOULD ERODE THE CAP AND COULD ALLOW FOR A FEW SHOWERS
AND STORMS TO DEVELOP. HI-RES MODEL GUIDANCE IS NOT VERY AGGRESSIVE
WITH THIS UNTIL THE LATER INTO THE EVENING WHEN A SQUALL LINE WILL
MOVE THROUGH THE REGION WITH THE FRONT LOSING SOME STEAM. WITH
VERTICAL TOTALS NEARING 30C AND SUFFICIENT LOW AND DEEP LAYER
SHEAR...WE COULD SEE SOME SEVERE STORMS PARTICULARLY IN THE DELTA
REGION LATER TOMORROW AFTERNOON INTO THE EVENING HOURS. THE PRIMARY
RISK WITH THESE WOULD BE FROM HAIL AND WIND. PW VALUES WILL BE RATHER
HIGH...AROUND 1.8-1.9 INCHES...AND THIS ALONG WITH POTENTIAL FOR
TRAINING STORMS COULD POSE A HEAVY RAIN/FLOODING RISK. WILL CONTINUE
TO MENTION ALL OF THESE HAZARDS IN THE HWO AND GRAPHICS.
AS THE FRONT OOZES SOUTH THROUGH THE REGION ON FRIDAY...THE POTENTIAL
FOR SEVERE STORMS WILL BE LOWER BUT NOT ZERO AS INSTABILITY WILL
REMAIN GOOD. WILL CONTINUE WITH THIS IN THE HWO/GRAPHICS AS WELL.
BEHIND THE FRONT...CLEARING CONDITIONS WILL OCCUR AS A 1025MB SFC
HIGH WILL SURGE INTO THE REGION. THE FRONT WILL STALL ALONG THE
SOUTHERN PORTIONS OF MY CWA OR JUST TO THE SOUTH OF IT. THIS WILL
HELP BRING SOME SHOWERS AND STORMS TO THE REGION THROUGH THE WEEKEND
AS THE AIRMASS WILL REMAIN MOIST AT LEAST FOR THE SOUTHERN PORTIONS
OF THE AREA. THE NORTHERN PORTIONS COULD DRY OUT A LITTLE WITH SOME
MIDLEVEL DRYING IN PLACE.
THE FRONT WILL RETURN NORTH AS A WARM FRONT LATER IN THE WEEKEND AS
THE SFC HIGH SHIFTS OFF TOWARD THE EAST COAST. ANOTHER MORE NOTABLE
SYSTEM LOOKS TO TAKE PLACE TO OUR WEST OVER THE TEXAS PANHANDLE COME
MONDAY. THIS WILL INCREASE MOISTURE AND SHOWER ACTIVITY OVER OUR
REGION TUESDAY. THE SYSTEM LOOKS TO GET INGESTED INTO THE UPPER
PATTERN AS IT MOVES OFF TO THE NORTHEAST. THAT BEING SAID...MODELS
CONTINUE TO SHOW RAIN IN OUR REGION AS THE SOUTHWEST UPPER LEVEL FLOW
BRINGS MOISTURE AND DISTURBANCES THROUGH. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 67 83 68 77 / 9 18 47 77
MERIDIAN 67 82 67 78 / 7 16 27 77
VICKSBURG 70 84 67 77 / 16 23 63 72
HATTIESBURG 66 84 69 81 / 9 16 16 77
NATCHEZ 69 83 68 78 / 16 20 38 74
GREENVILLE 69 81 64 71 / 11 33 82 42
GREENWOOD 69 82 64 74 / 10 19 81 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CDT Mon Apr 6 2015
.UPDATE:
Issued at 901 PM CDT Mon Apr 6 2015
Weak, scattered convection just east of 3LF will shift east of the
forecast area later this evening, while another area of scattered,
slightly stronger convection around UUV will move eastward into
portions of southwestern IL later this evening. A persistent and
localized area of fog continues in the FAM area this evening.
Still a lot of uncertainty with regards to additional convection
for late tonight into Tuesday morning. The latest operational
models have most of their QPF across southeast MO and southwest
IL, mainly just southeast of our forecast area. Some of the high
resolution, explicit models develop more organized convection,
potentially an MCS in a region of strong low level warm air
advection on the nose of a southwesterly low level jet which moves
east-southeastward into northeast or central MO towards morning
along and just north of a developing surface warm front. This
convection should be elevated and may produce hail. The 00Z
Tuesday TOP sounding indicated a capped atmosphere which may
hinder much convective development across much of eastern KS and
western MO. For now will continue with the going forecast of pops
increasing into the chance catagory for our entire forecast area
late tonight. Unseasonably warm conditions, about 15 to 20 degrees
above normal can be expected tonight due to low level cloud
cover, south-southeasterly surface winds, low level warm air
advection, and high surface dewpoints. Temperatures in portions of
the forecast area will remain nearly steady through the night.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 344 PM CDT Mon Apr 6 2015
Low pressure over the Great Plains continues to push a warm and
moist airmass into the region. Guidance suggests that convection
will blossom after 06-08Z somewhere over the CWFA as the nose of a
35-40kt low level jet runs into the 850mb baroclinic zone which is
draped over the area. Resulting isentropic lift should produce an
area of convection late tonight. This is all good in theory,
however short range guidance including the NAM and RAP show a decent
inversion above the level of free convection on forecast soundings
at various locations and times across the area. This puts
significant doubt on timing and coverage of convection late
tonight. Current feeling is that the best chance for storms to
develop will be 08Z or later, and possibly near the I-70 corridor in
Missouri. Ample pre-storm MUCAPE in excess of 1500-2000 J/kg and
persistent LLJ/isentropic lift should allow storms to increase in
coverage through 12Z. Also, with that kind of instability available
and forecast deep layer shear around 40kts, could see some storms
produce large hail. Only the uncertainty of where the storms will
form and ultimate areal coverage has dissuaded me from going with
likely or higher PoPs. As it stands, have 40-50% across the entire
CWFA late tonight, as this should allow the evening shift to
monitor latest trends and adjust as necessary.
Carney
.LONG TERM: (Tuesday through Next Monday)
Issued at 344 PM CDT Mon Apr 6 2015
Main forecast concern continues to be precipitation chances.
Obviously, threat of convection will be very high by Thursday and
Thursday night as deep upper level trof and associated surface
features push into the mid Mississippi Valley...the primary
problem is trying to pin down spatial and temporal convective
trends from tomorrow morning until the widespread and stormy
weather that is expected by Thursday.
The elevated storms that do develop late tonight should wind down
during the morning, leaving unstable but capped AMS blanketing the
area from Tuesday afternoon into Wednesday morning. Current
forecast soundings would suggest that southward sagging frontal
boundary will not be enough to bust through the warm mid level
temps, but there also seems to be some hints of very weak
shortwave energy ejecting into the area from the upper trof to our
west that could produce more elevated activity. In truth I can
probably dream up 2 or 3 scenarios on how convection could evolve
during this time, but with so much uncertainty for now plan on
sticking with going forecast trends, which generally indicate low
chance PoPs over most of the CWA during this time frame.
Fine-tuning will have to wait until this time period gets a bit
closer and specifics (hopefully) become clearer.
In spite of the considerable abiguity in precip trends heading into
mid week, today`s model guidance as well as that over the past
several days continue to point to widespread convection as we head
into Wednesday night and Thursday, with storms continuing into at
least Thursday evening. Intensifying surface low over the central
Plains on Wednesday afternoon will lead to increasing WAA
advection and isentropic ascent north of the frontal boundary.
This low level level forcing should then punch through the mid-
level cap which should begin to weaken by this time as heights
begin to fall in advance of the upper level trof. This round of
convection will work east as the synoptic front pushes north of
the area, placing the entire CWA in the warm sector of the surface
cyclone by Thursday morning. More convection should develop during
the day either from additional shortwave energy or perhaps the
effects of any residual boundaries from Wednesday night`s
activity, with a final shot of convection occurring along the cold
front as we head into the evening hours.
The synoptic models have backed off some on the instability
forecast, perhaps due to extensive cloudiness in the low levels as
well as a weakening of the nearly dry adiabtic lapse rates in the
EML that are progged early on during the forecast cycle. However,
kinematic and synoptic fields still strongly suggest a severe
weather threat...or more likely several episodes of severe
weather...from Wednesday night into Thursday evening. As alluded
to in the day3 and day 4 SPC discussions, threat of large hail and
damaging winds looks fairly substantial, while specific tornado
threat will at least be partially predicated on the specific
locations of fronts and any residual boundaries.
Uncertain how to handle the passage of the cold front/end of
thunderstorm threat. Initial thought was to slow it down a bit as a
common model bias is to be too fast with strong upper level systems,
but on the other hand convection along the front will likely be
screaming to the east, so effective bounday may race ahead of the
actual front. So, will continue thunderstorm threat across the
entire CWA on Thursday night, but will go dry by Friday.
It appears that this dry weather will continue into Saturday, with
thunderstorm chances returning by Sunday and Monday.
In spite of the fact that there will be considerable cloudiness,
there should be plenty of warmth through Thursday, with highs
primarily ranging from the middle 70s to lower 80s. The exception
to this may be over our northern counties on Wednesday, where
southward drift of the cold front will back off temps into the upper
60s and lower 70s. Arrival of the cold air will mean more
seasonable temps by Friday and Saturday.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Tuesday Night)
Issued at 1153 PM CDT Mon Apr 6 2015
Showers and thunderstorms developed in warm sector this evening
and remain just out of TAF sites. For now cigs will be the main
issue varying between VFR, MVFR and IFR. As warm front lifts north
through region, cigs to lower down to IFR between 07z and 09z
Tuesday. Models now holding off precip for TAF sites til closer to
daybreak, after 11z Tuesday, as complex develops over central MO
and slides east along I-70 corridor, before diminishing by mid
morning. Then front to lift north allowing cigs to lift and thin
out a bit. As for winds, to remain southeast to south for sites
along I-70 corridor while KUIN will see southeast winds back to
the east as front moves closer, then eventually veer back to the
south as front lifts north of KUIN.
Specifics for KSTL:
Showers and thunderstorms developed in warm sector this evening
and remain just south of metro area TAFs. For now cigs will be the
main issue varying between VFR, MVFR and IFR. As warm front lifts
north through region, cigs to lower down to IFR by 07z Tuesday.
Models now holding off precip for STL til closer to daybreak,
after 12z Tuesday, as complex develops over central MO and slides
east along I-70 corridor, before diminishing by 15z Tuesday. Then front
to lift north allowing cigs to lift and thin out a bit. As for
winds, to remain southeast to south.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
943 PM MDT WED APR 8 2015
.UPDATE...
ONE FINAL UPDATE. HAVE CANCELLED THE WINTER WX ADVISORY FOR OUR
PORTION OF THE BIGHORN MOUNTAINS AS DRIER AIR IS WORKING IN FROM
THE NORTH AND PCPN HAS BECOME MUCH LIGHTER. ANY ADDITIONAL ACCUMS
WILL BE MINIMAL...BUT SOME SNOTELS DID PICK UP AT LEAST 6-7 INCHES
OF SNOW SINCE EARLY AFTERNOON. JKL
PREVIOUS DISCUSSION ISSUED 751 PM...
PRECIPITATION MAINLY IN THE FORM OF SNOW IN OUR FAR EAST...A
RESULT OF MID LEVEL FRONTOGENESIS AND UPPER JET DIVERGENCE...IS
BECOMING LIGHTER AND MOVING TO THE EAST. WE HAVE HAD SEVERAL
REPORTS OF BETWEEN A HALF AND THREE- QUARTERS OF AN INCH OF PCPN
ALONG AND EAST OF A MIZPAH TO BROADUS LINE. AS FOR SNOWFALL...THE
WINNER TO THIS POINT IS A SIX INCH REPORT FROM PLEVNA. WILL
SUSTAIN HIGH POPS IN OUR EAST THROUGH 03Z THEN TAPER THEM OFF
QUICKLY...WITH EXPECTATION OF MOST PCPN BEING DONE BY MIDNIGHT. IN
THE WEST...AREA OF SHOWERS EMBEDDED IN NORTHEASTERLY MID LEVEL
FLOW WAS A RESULT OF SLIGHTLY NEGATIVE LIFTED INDICES...BUT THIS
ACTIVITY IS FIZZLING OUT AS WE APPROACH SUNSET. WILL DRY OUT OUR
WEST BY MIDNIGHT BASED ON THESE TRENDS...AS ANY ACTIVITY
ASSOCIATED W/ WEAK LOW OVER THE PAC NW SHOULD REMAIN TO OUR WEST.
OTHER POTENTIAL ISSUE IS FOG TONIGHT GIVEN THE RECENT PCPN ALONG
WITH DECREASING CLOUDS AND WINDS THROUGH THE NIGHT. HRRR IS
STARTING TO HINT AT FOG IN OUR EAST AFTER MIDNIGHT. WOULD ALSO NOT
BE SURPRISED TO SEE AT LEAST LOCALIZED FOG IN OUR WEST AND CENTRAL
PARTS EVEN W/O THE PCPN TODAY...GIVEN DEWPTS AROUND 30F WHICH SFC
TEMPS SHOULD FALL TO OR SLIGHTLY BELOW TONIGHT. HAVE ADDED MENTION
OF PATCHY FOG ACROSS MOST OF OUR CWA FROM 06Z TONIGHT TO 15Z
TOMORROW MORNING. HAVE ALSO TWEAKED EXPECTED LOW TEMPS DOWN A BIT.
JKL
&&
.SHORT TERM...VALID FOR THU AND FRI...
THROUGH THE MORNING...MOST OF THE ACTIVITY WAS TO EAST OF THE
AREA INTO NORTH DAKOTA AND BARELY GETTING INTO BAKER. THE MODELS
WERE BEING TOO AGGRESSIVE WITH GENERATING PRECIP IN SOUTHEAST
MONTANA. THE SREF MEANS AT SHERIDAN AND MILES CITY HAS BEEN
TRENDING DOWNWARDS WITH THE PRECIP AMOUNTS. THAT BEING SAID...THE
MODELS CONTINUE TO SHOW THE PRECIP WILL BE INCREASING THIS
EVENING. THE RADAR IS GIVING CREDENCE TO THIS TREND...AS COVERAGE
AND INTENSITY HAS BEEN INCREASING. HAVE NOT MADE TOO MANY CHANGE
TO THE FORECAST FOR TONIGHT. HAVE TRENDED SNOW AMOUNTS DOWN
SLIGHTLY...GENERALLY 1 TO 2 INCHES ACROSS THE SOUTHEASTERN
ZONES...WHILE ANOTHER 2 TO 5 INCHES IN THE BIGHORNS. THE ADVISORY
REMAINS IN PLACE.
GOING INTO TOMORROW AND FRIDAY...THE LOW THAT AFFECTED THE AREA
TODAY WILL MOVE OFF INTO THE CENTRAL PLAINS AND PRECIP CHANCES
ACROSS THE AREA WILL BE OUT OF THE AREA BY EARLY AFTERNOON
TOMORROW....AT THE LATEST. A RIDGE WILL DEVELOP OVER THE NORTHERN
ROCKIES...BUT WILL QUICKLY MOVE WEST DURING THE DAY ON FRIDAY. AS
THE RIDGE MOVES OUT...A WEAK WAVE WILL MOVE THROUGH...BUT OUTSIDE
OF THE SOUTHWEST MOUNTAINS...FRIDAY LOOKS TO BE DRY. TEMPS WILL BE
WARMING THROUGH THE REMAINDER OF THE WEEK...WITH 50S FOR THURSDAY
AND INTO THE 60S ON FRIDAY. REIMER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
ALL EYES ON MEDIUM RANGE GUIDANCE TOWARD THE END OF THE EXTENDED
(MIDDLE PART OF NEXT WEEK) WHEN A POTENT UPPER LOW IS FORECAST TO
MOVE INTO THE NORTHERN ROCKIES.
UNTIL THEN...WEATHER FAIRLY QUIET BUT MAY NEED TO MONITOR FIRE
WEATHER AGAIN OVER THE WEEKEND. NEXT SHORT WAVE AND ASSOCIATED
COLD FRONT WILL PUSH ACROSS THE REGION SATURDAY NIGHT. PREFRONTAL
ENVIRONMENT ON SATURDAY SHOULD RESULT IN OUR WARMEST DAY OF THE
EXTENDED WITH TEMPERATURES BACK TO NEAR 70 WITH FRONTAL PASSAGE
SATURDAY NIGHT. SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING
WIDESPREAD. DRY WITH GUSTY NORTHWEST WINDS BEHIND THE SYSTEM FOR
SUNDAY. THESE DAYS WILL HAVE TO BE MONITORED FOR ANY FIRE WEATHER
CONCERNS DEPENDING ON HOW ARE FUELS ARE LOOKING. BUT WINDS WILL BE
GUSTY AND HUMIDITIES BACK INTO THE TEENS.
SIGNIFICANT TROUGHING DEVELOPS ALONG THE WEST COAST MONDAY BEFORE
SHIFTING EAST INTO THE NORTHERN ROCKIES BY THE MIDDLE OF NEXT
WEEK. MODELS ALL INDICATING A SIGNIFICANT STORM WITH HEAVIER
PRECIPITATION POSSIBLE...BUT PATH OF SYSTEM OFFERING LARGE
UNCERTAINTIES. FOR NOW...HAVE CONTINUED WITH FAIRLY HIGH PRECIP
CHANCES OUT 7 AND 8 DAYS. TEMPERATURES WILL HAVE TO BE MONITORED
CLOSELY DEPENDING ON THE PATH OF THIS SYSTEM. STAY TUNED. FRIEDERS
&&
.AVIATION...
RAIN AND SNOW WILL CONTINUE ALONG AND EAST OF A KSHR-KBHK LINE
THROUGH THE REMAINDER OF THE EVENING. THE PRECIP WILL SLOWLY TAPER
OFF AFTER 06Z BUT LINGERING SHOWERS WILL CONTINUE FOR THOSE AREAS.
EXPECT MVFR-IFR CONDITIONS IN THE RAIN AND SNOW WITH IMPROVING
CONDITIONS AFTER 06Z. ELSEWHERE...PARTLY CLOUDY SKIES ALONG WITH
AN ISOLATED SHOWER CAN BE EXPECTED WITH VFR CONDITIONS PREVAILING.
THE MOUNTAINS WILL BE OBSCURED THROUGHOUT THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 030/057 035/063 040/069 040/061 033/064 039/063 038/056
10/B 01/B 01/N 31/N 11/B 33/W 45/W
LVM 025/054 033/059 037/063 034/056 030/059 035/060 034/051
21/B 12/W 12/W 31/N 12/W 33/W 55/W
HDN 028/058 031/066 035/071 038/062 031/066 036/066 034/058
10/B 01/B 01/B 31/N 11/B 23/W 45/W
MLS 028/056 032/065 037/070 039/061 032/065 038/062 038/057
10/B 00/U 01/U 31/N 11/B 23/W 45/W
4BQ 028/052 029/063 035/070 038/060 031/066 037/064 036/058
20/B 00/B 01/U 21/B 11/B 33/W 45/W
BHK 027/054 028/063 033/068 037/059 030/064 036/064 035/059
30/B 00/U 11/U 21/N 11/B 22/W 45/W
SHR 026/051 027/060 033/066 036/058 031/064 035/063 034/054
30/B 01/B 01/B 31/B 11/B 33/W 45/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
751 PM MDT WED APR 8 2015
.UPDATE...
PRECIPITATION MAINLY IN THE FORM OF SNOW IN OUR FAR EAST...A
RESULT OF MID LEVEL FRONTOGENESIS AND UPPER JET DIVERGENCE...IS
BECOMING LIGHTER AND MOVING TO THE EAST. WE HAVE HAD SEVERAL
REPORTS OF BETWEEN A HALF AND THREE-QUARTERS OF AN INCH OF PCPN
ALONG AND EAST OF A MIZPAH TO BROADUS LINE. AS FOR SNOWFALL...THE
WINNER TO THIS POINT IS A SIX INCH REPORT FROM PLEVNA. WILL
SUSTAIN HIGH POPS IN OUR EAST THROUGH 03Z THEN TAPER THEM OFF
QUICKLY...WITH EXPECTATION OF MOST PCPN BEING DONE BY MIDNIGHT. IN
THE WEST...AREA OF SHOWERS EMBEDDED IN NORTHEASTERLY MID LEVEL
FLOW WAS A RESULT OF SLIGHTLY NEGATIVE LIFTED INDICES...BUT THIS
ACTIVITY IS FIZZLING OUT AS WE APPROACH SUNSET. WILL DRY OUT OUR
WEST BY MIDNIGHT BASED ON THESE TRENDS...AS ANY ACTIVITY
ASSOCIATED W/ WEAK LOW OVER THE PAC NW SHOULD REMAIN TO OUR WEST.
OTHER POTENTIAL ISSUE IS FOG TONIGHT GIVEN THE RECENT PCPN ALONG
WITH DECREASING CLOUDS AND WINDS THROUGH THE NIGHT. HRRR IS
STARTING TO HINT AT FOG IN OUR EAST AFTER MIDNIGHT. WOULD ALSO NOT
BE SURPRISED TO SEE AT LEAST LOCALIZED FOG IN OUR WEST AND CENTRAL
PARTS EVEN W/O THE PCPN TODAY...GIVEN DEWPTS AROUND 30F WHICH SFC
TEMPS SHOULD FALL TO OR SLIGHTLY BELOW TONIGHT. HAVE ADDED
MENTION OF PATCHY FOG ACROSS MOST OF OUR CWA FROM 06Z TONIGHT TO
15Z TOMORROW MORNING. HAVE ALSO TWEAKED EXPECTED LOW TEMPS DOWN A
BIT.
JKL
&&
.SHORT TERM...VALID FOR THU AND FRI...
THROUGH THE MORNING...MOST OF THE ACTIVITY WAS TO EAST OF THE
AREA INTO NORTH DAKOTA AND BARELY GETTING INTO BAKER. THE MODELS
WERE BEING TOO AGGRESSIVE WITH GENERATING PRECIP IN SOUTHEAST
MONTANA. THE SREF MEANS AT SHERIDAN AND MILES CITY HAS BEEN
TRENDING DOWNWARDS WITH THE PRECIP AMOUNTS. THAT BEING SAID...THE
MODELS CONTINUE TO SHOW THE PRECIP WILL BE INCREASING THIS
EVENING. THE RADAR IS GIVING CREDENCE TO THIS TREND...AS COVERAGE
AND INTENSITY HAS BEEN INCREASING. HAVE NOT MADE TOO MANY CHANGE
TO THE FORECAST FOR TONIGHT. HAVE TRENDED SNOW AMOUNTS DOWN
SLIGHTLY...GENERALLY 1 TO 2 INCHES ACROSS THE SOUTHEASTERN
ZONES...WHILE ANOTHER 2 TO 5 INCHES IN THE BIGHORNS. THE ADVISORY
REMAINS IN PLACE.
GOING INTO TOMORROW AND FRIDAY...THE LOW THAT AFFECTED THE AREA
TODAY WILL MOVE OFF INTO THE CENTRAL PLAINS AND PRECIP CHANCES
ACROSS THE AREA WILL BE OUT OF THE AREA BY EARLY AFTERNOON
TOMORROW....AT THE LATEST. A RIDGE WILL DEVELOP OVER THE NORTHERN
ROCKIES...BUT WILL QUICKLY MOVE WEST DURING THE DAY ON FRIDAY. AS
THE RIDGE MOVES OUT...A WEAK WAVE WILL MOVE THROUGH...BUT OUTSIDE
OF THE SOUTHWEST MOUNTAINS...FRIDAY LOOKS TO BE DRY. TEMPS WILL BE
WARMING THROUGH THE REMAINDER OF THE WEEK...WITH 50S FOR THURSDAY
AND INTO THE 60S ON FRIDAY. REIMER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
ALL EYES ON MEDIUM RANGE GUIDANCE TOWARD THE END OF THE EXTENDED
(MIDDLE PART OF NEXT WEEK) WHEN A POTENT UPPER LOW IS FORECAST TO
MOVE INTO THE NORTHERN ROCKIES.
UNTIL THEN...WEATHER FAIRLY QUIET BUT MAY NEED TO MONITOR FIRE
WEATHER AGAIN OVER THE WEEKEND. NEXT SHORT WAVE AND ASSOCIATED
COLD FRONT WILL PUSH ACROSS THE REGION SATURDAY NIGHT. PREFRONTAL
ENVIRONMENT ON SATURDAY SHOULD RESULT IN OUR WARMEST DAY OF THE
EXTENDED WITH TEMPERATURES BACK TO NEAR 70 WITH FRONTAL PASSAGE
SATURDAY NIGHT. SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING
WIDESPREAD. DRY WITH GUSTY NORTHWEST WINDS BEHIND THE SYSTEM FOR
SUNDAY. THESE DAYS WILL HAVE TO BE MONITORED FOR ANY FIRE WEATHER
CONCERNS DEPENDING ON HOW ARE FUELS ARE LOOKING. BUT WINDS WILL BE
GUSTY AND HUMIDITIES BACK INTO THE TEENS.
SIGNIFICANT TROUGHING DEVELOPS ALONG THE WEST COAST MONDAY BEFORE
SHIFTING EAST INTO THE NORTHERN ROCKIES BY THE MIDDLE OF NEXT
WEEK. MODELS ALL INDICATING A SIGNIFICANT STORM WITH HEAVIER
PRECIPITATION POSSIBLE...BUT PATH OF SYSTEM OFFERING LARGE
UNCERTAINTIES. FOR NOW...HAVE CONTINUED WITH FAIRLY HIGH PRECIP
CHANCES OUT 7 AND 8 DAYS. TEMPERATURES WILL HAVE TO BE MONTIRED
CLOSELY DEPENDING ON THE PATH OF THIS SYSTEM. STAY TUNED. FRIEDERS
&&
.AVIATION...
RAIN AND SNOW WILL CONTINUE ALONG AND EAST OF A KSHR-KBHK LINE
THROUGH THE REMAINDER OF THE EVENING. THE PRECIP WILL SLOWLY TAPER
OFF AFTER 06Z BUT LINGERING SHOWERS WILL CONTINUE FOR THOSE AREAS.
EXPECT MVFR-IFR CONDITIONS IN THE RAIN AND SNOW WITH IMPROVING
CONDITIONS AFTER 06Z. ELSEWHERE...PARTLY CLOUDY SKIES ALONG WITH
AN ISOLATED SHOWER CAN BE EXPECTED WITH VFR CONDITIONS PREVAILING.
THE MOUNTAINS WILL BE OBSCURED THROUGHOUT THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 029/057 035/063 040/069 040/061 033/064 039/063 038/056
10/B 01/B 01/N 31/N 11/B 33/W 45/W
LVM 025/054 033/059 037/063 034/056 030/059 035/060 034/051
21/B 12/W 12/W 31/N 12/W 33/W 55/W
HDN 028/058 031/066 035/071 038/062 031/066 036/066 034/058
10/B 01/B 01/B 31/N 11/B 23/W 45/W
MLS 028/056 032/065 037/070 039/061 032/065 038/062 038/057
10/B 00/U 01/U 31/N 11/B 23/W 45/W
4BQ 028/052 029/063 035/070 038/060 031/066 037/064 036/058
90/B 00/B 01/U 21/B 11/B 33/W 45/W
BHK 027/054 028/063 033/068 037/059 030/064 036/064 035/059
+0/B 00/U 11/U 21/N 11/B 22/W 45/W
SHR 026/051 027/060 033/066 036/058 031/064 035/063 034/054
+0/B 01/B 01/B 31/B 11/B 33/W 45/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT THURSDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
632 PM CDT WED APR 8 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT WED APR 8 2015
PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT
AND ALSO SHOWERS ON THURSDAY.
SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD
OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO
SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM
12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP
TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY
AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO.
GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH
HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME
STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA.
OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE
WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP
BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR
SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR
MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE
FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL
MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE
COULD ALSO BE SOME LOCALLY HEAVY RAIN.
SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH
HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST
AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE
LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE
PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH
WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED
FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY.
PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY
NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT
AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT...
MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT.
WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES
SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 PM CDT WED APR 8 2015
WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE
EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS
LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT
INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT
SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 629 PM CDT WED APR 8 2015
IFR TO LIFR CONDITIONS WILL CONTINUE THROUGHOUT THE TAF PERIOD AS
AN AREA OF LOW PRESSURE SKIRTS TO OUR SOUTHEAST. A FEW SCATTERED
SHOWERS AND POSSIBLY THUNDERSTORMS MAY MOVE ACROSS THE TAF SITES
OVERNIGHT BUT SHOULD PUSH EAST OF THE AREA BY LATE MORNING. A STRONG
COLD FRONT WILL TURN WINDS TO THE NORTHWEST BY THE EARLY AFTERNOON
WITH GUSTS UP TO 35KTS POSSIBLE. ANOTHER ROUND OF SHOWERS ARE
POSSIBLE BEHIND THIS FRONT THROUGH THE AFTERNOON...ESPECIALLY IN
KOFK AND KOMA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
634 AM CDT TUE APR 7 2015
.SYNOPSIS...
ISSUED AT 400 AM CDT TUE APR 7 2015
H5 ANALYSIS FROM TONIGHT HAS A CLOSED LOW OVER NRN QUEBEC...WITH
A BROAD TROUGH EXTENDING SWD INTO NEW ENGLAND. FURTHER WEST...A
SECOND LOW WAS PRESENT OFF THE COAST OF SWRN OREGON WITH A TROUGH
EXTENDING SWD TO OFF THE COAST OF CENTRAL CALIFORNIA. AT THE
SURFACE...LOW PRESSURE WAS PRESENT OVER NORTHERN COLORADO...WITH A
STATIONARY FRONT EXTENDING ESE INTO WESTERN KS...THEN EAST
NORTHEAST INTO EAST CENTRAL KS. NORTH OF THIS FEATURE
TONIGHT...EASTERLY WINDS AND PLENTY OF LOW LEVEL MOISTURE HAVE
PUSHED INTO WESTERN AND NORTH CENTRAL NEBRASKA. IN ADDITION TO
AREAS OF FOG...OCCASIONAL DRIZZLE WAS REPORTED AT MOST OBSERVATION
STATIONS ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. WITH CLOUDY
SKIES PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL
NEBRASKA...TEMPERATURES RANGED FROM 36 AT VALENTINE TO 50 AT
BROKEN BOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGE IS
PRECIPITATION CHANCES...ALONG WITH THE THREAT OF FOG AND DRIZZLE.
FOR THIS MORNING...LOW POPS WILL CONTINUE DUE TO A COMBINATION OF
OCCASIONAL DRIZZLE WHICH WILL BE HEAVY ENOUGH TO MEASURE...AND THE
THREAT FOR SHOWERS IN ASSOCIATION WITH A WEAK DISTURBANCE AND MID
LEVEL MOISTURE WHICH WILL CROSS THE SANDHILLS AND NORTHERN
NEBRASKA THIS MORNING. PRECIPITATION CHANCES WILL COME TO AN END
TEMPORARILY THIS AFTERNOON...AS THE BOUNDARY LAYER WARMS AND CIGS
LIFT...ALONG WITH MID LEVEL MOISTURE EXITING THE FORECAST AREA TO
THE EAST. FOR THE MOST PART...SKIES WILL REMAIN CLOUDY TODAY
ACROSS THE FORECAST AREA...AS WE REMAIN UNDER A THICK VEIL OF
STRATUS. THE EXCEPTION MAY BE ACROSS THE PANHANDLE COUNTIES...AS
THE LATEST HRRR AND NAM DO INDICATE SOME SCATTERING OUT OF CLOUDS
DURING PEAK HEATING THIS AFTERNOON. HOWEVER...THE MODELS INDICATED
A DECENT AMOUNT OF CLEARING FOR YESTERDAY WITH HEATING...WHICH FOR
THE MOST PART...DIDN/T MATERIALIZE. WITH THIS IN MIND...WENT
COOLER ON HIGHS TODAY THAN GUIDANCE...HEDGING ON CLOUDS REMAINING
ENTRENCHED ACROSS THE FORECAST AREA TODAY. CIGS WILL LOWER THIS
EVENING...WITH ANOTHER ROUND OF DRIZZLE AND FOG ACROSS THE
FORECAST AREA. FCST SOUNDINGS AND CROSS SECTIONS INDICATE A NEAR
SATURATED LAYER FROM THE SFC TO H85 TONIGHT...COLLOCATED WITH WEAK
OMEGA IN THIS LAYER AND VERY DRY CONDS ALOFT. DID GO AHEAD AND
INCREASE POPS OVERNIGHT AS SOME MID LEVEL MOISTURE LIFTS INTO THE
FORECAST AREA FROM THE SOUTHWEST...WHICH MAY LEAD TO LIGHT
PRECIPITATION IN ADDITION TO ANY DRIZZLE WHICH IS EXPECTED AS
WELL. LOWS TONIGHT WILL BE MILD GIVEN THE CLOUD COVER AND MOIST
BOUNDARY LAYER CONDS...WITH READINGS RANGING FROM THE UPPER 30S IN
THE FAR NORTH...TO LOWER TO MID 40S IN THE CENTRAL AND SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE APR 7 2015
FORECAST CONCERNS CONTINUE TO DEAL WITH DRIZZLE/FOG/RAIN CHANCES
THROUGH WEDNESDAY WHICH BRING UP THE CONCERN OF TEMPERATURES. THEN
FOCUS TURNS TO MAIN UPPER LEVEL SYSTEM MOVING ACROSS THE CENTRAL
PLAINS THURSDAY WHICH BRINGS CHANCES FOR RAIN/SNOW AND STRONG WINDS
TO THE FORECAST AREA. THE PATTERN THEN REMAINS ACTIVE AS THE LOCAL
AREA GETS IMPACTED BY SYSTEMS MOVING THROUGH BOTH THE NORTHERN AND
SOUTHERN STREAMS INTO THE FIRST PART OF NEXT WEEK.
FORECAST MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE
PERIOD...HOWEVER THERE HAVE BEEN SOME RUN TO RUN INCONSISTENCIES
WHICH HAS KEPT CONFIDENCE LOWER THAN WOULD BE DESIRED.
BEGINNING ON WEDNESDAY...THE PRIMARY UPPER LEVEL LOW WILL MOVE INTO
THE CENTRAL ROCKIES WITH A WEAK SHORTWAVE TROUGH EJECTING OUT AHEAD
OF THE MAIN SYSTEM DURING THE DAY WEDNESDAY. MODELS CONTINUE TO
DEVELOP QPF OVER MUCH OF NEBRASKA ON WEDNESDAY...HOWEVER LOOKING AT
MOISTURE PROFILES IN CROSS SECTIONS ACROSS THE AREA AND FORECAST
SOUNDINGS...THE MOISTURE REMAINS QUITE SHALLOW...BELOW 750MB. THE
LIFT ASSOCIATED WITH THE SHORTWAVE TROUGH DOES HELP PROVIDE LIFT
THROUGH THE COLUMN BUT WITH THE AIR ABOVE 750MB BEING SO EXTREMELY
DRY...THIS LIFT WILL NOT HAVE ANYTHING TO WORK WITH AND SO WILL HAVE
NO IMPACT ON THE FORECAST. IF THERE WOULD BE MOISTURE...COULD ARGUE
FOR NEEDING MENTION OF THUNDERSTORMS AS THE LAPSE RATES ARE QUITE
STEEP LEADING TO AT LEAST SOME INSTABILITY...BUT AGAIN NO MOISTURE
WILL PROHIBIT THE NEED FOR THUNDER MENTION. BACK TO THE LOW
LEVELS...THERE IS DECENT LIFT WITHIN THE SATURATED LAYER AND WITH
LIGHT EASTERLY WINDS CONTINUING THROUGH WEDNESDAY NIGHT...THE SLIGHT
UPSLOPE FLOW WILL HELP KEEP STRATUS/FOG/DRIZZLE POTENTIAL THROUGH
THE DAY. WITH THIS EXPECTATION...DON/T THINK TEMPERATURES WILL RISE
MUCH THROUGH THE DAY WEDNESDAY AND HAVE LOWERED HIGHS SUBSTANTIALLY.
THE FRONT WILL BE JUST SOUTH OF THE FORECAST AREA SO THERE MAY BE A
TIGHT GRADIENT WHERE CLOUDS/COLDER TEMPERATURES EXIST TO WHERE THERE
IS PLENTIFUL SUNSHINE AND HIGHS UP INTO THE 70S. BELIEVE THAT THIS
WILL BE SOUTH OF THE FORECAST AREA THROUGH.
THE WHOLE UPPER LEVEL SYSTEM CONTINUES TO MOVE EAST THROUGH THE DAY
THURSDAY...AND WHILE THEY ARE IN AGREEMENT WITH THE UPPER LOW
PASSING OVER THE REGION AND DUMPING SOME DECENT MOISTURE ACROSS THE
FORECAST AREA...THESE SOLUTIONS ARE DIFFERENT FROM PRIOR RUNS AS ALL
ARE NOW MOVING THE SYSTEM ACROSS THE AREA AS AN OPEN WAVE AND IN
TURNS MOVES IT ACROSS THE AREA FASTER...WITH PRECIPITATION ENDED BY
MID-DAY THURSDAY. THEY STILL PRODUCE QUITE A BIT OF QPF ON THE
NORTHWEST SIDE OF THE FORECAST AREA DESPITE MOVING ACROSS THE AREA
FASTER THAN WAS EARLIER THOUGHT. DID REMOVE MENTION OF
THUNDERSTORMS FOR WEDNESDAY NIGHT AND THURSDAY. THE FRONT WILL
REMAIN WELL SOUTH AND EAST OF THE LOCAL AREA AS THE SURFACE LOW
STAYS ACROSS KANSAS AS IT MOVES EASTWARD. THIS WILL KEEP THE
WARMER AIR...PLUS ANY MOISTURE ADVECTION/LIFT ALONG THE FRONT AWAY
FROM THE LOCAL AREA. AND...THE LOW LEVEL JET WILL BE WELL TO THE
EAST SO REALLY NOT CONCERNED ABOUT THUNDERSTORMS. THEN ON THURSDAY
AS THE SURFACE LOW ACROSS KANSAS TRANSITIONS INTO THE MISSISSIPPI
RIVER VALLEY THE PRESSURE GRADIENT WILL TIGHTEN...BRINGING STRONG
NORTHERLY WINDS TO THE FORECAST AREA. THIS WILL LEAD TO CONDITIONS
FEELING QUITE RAW AS APPARENT TEMPERATURES ARE LOOKING TO BE IN
THE 20S AND 30S. WITH THE COOLER AIR MOVING IN FROM THE NORTH...IT
IS LIKELY THAT THE PRECIPITATION WILL CHANGE OVER TO A RAIN/SNOW
MIX AND THEN OVER TO SNOW COMPLETELY OVER PARTS OF THE PANHANDLE.
DON/T THINK AMOUNTS WILL BE MUCH...BUT COULD SEE THE GROUND BECOME
WHITE FOR A SHORT PERIOD IN PLACES.
AGAIN AS THIS IS NOT MOVING THROUGH AS AN OPEN WAVE...IT WILL MOVE
THROUGH THE LOCAL AREA QUICKLY AND HAVE ENDED PRECIPITATION
CHANCES ABOUT 6 HOURS EARLIER THAN IN THE PRIOR FORECAST.
SHORTWAVE RIDGING BUILDS INTO THE CENTRAL PLAINS BRIEFLY FRIDAY
NIGHT...WHILE AN UPPER LOW IN THE SOUTHERN STREAM MOVES ACROSS THE
SOUTHERN CONUS AND NORTHERN MEXICO. MEANWHILE ANOTHER POTENT
SYSTEM MOVES INTO THE PACIFIC NORTHWEST. THESE SYSTEMS WILL BOTH
PROGRESS EASTWARD AND THERE IS SOME INDICATION THAT THEY MAY
ATTEMPT TO INTERACT EARLY NEXT WEEK WHICH COULD BRING ANOTHER WET
PERIOD TO THE FORECAST AREA FOR MONDAY AND TUESDAY. CONFIDENCE IS
NOT HIGH IN THIS OCCURRING RIGHT NOW SO WILL MAINTAIN LOW END
PRECIPITATION CHANCES FOR NOW.
ULTIMATELY WITH THE MORE ACTIVE PATTERN...WILL SEE MORE CHANCES
FOR PRECIPITATION...AND TEMPERATURES CLOSER TO NORMAL...ALTHOUGH
THERE WILL BE DAYS WITH HIGHER TEMPERATURES. HOWEVER THERE ARE NO
CURRENT INDICATIONS OF ANOTHER PERIOD OF WELL ABOVE NORMAL
TEMPERATURES FOR THE FORECAST AREA AT THIS TIME.
AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CDT MON APR 6 2015
LIFR CEILINGS CURRENTLY AT THE KLBF AND KVTN TERMINALS IS FORECAST
TO PERSIST UNTIL 15Z. VSBY WILL LIKELY RANGE NEAR 1SM -DZ BR AT
KVTN WHILE LOWERING TO 3SM -DZ BR AT KLBF. AFTER 15Z...CEILINGS
AND VSBYS WILL IMPROVE TO IFR...AND TO MVFR AFTER 18Z.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 635 AM CDT TUE APR 7 2015
OVERCAST SKIES ARE EXPECTED OVER THE NEXT 24 HOURS AT BOTH THE
KLBF AND KVTN TERMINALS WITH MVFR AND IFR CIGS TODAY...AND THE
THREAT FOR LIFR CIGS TONIGHT. FOR THE KLBF TERMINAL...EXPECT MVFR
CIGS TODAY WITH CLOUD DECKS RANGING FROM 1600 TO 2200 FT AGL. SOME
CIGS MAY BE AROUND 700 FT AGL THIS MORNING. CIGS WILL FALL TO 600
TO 1200 FT AGL AFTER MID EVENING TONIGHT. FOR THIS
MORNING...PERIODS OF DRIZZLE ARE POSSIBLE WITH VISBYS AS LOW AS
3SM. DRIZZLE WILL BE POSSIBLE ONCE AGAIN OVERNIGHT TONIGHT WITH
VISBYS DOWN TO 4SM. FOR THE KVTN TERMINAL...EXPECT CIGS RANGING
FROM 300 TO 500 FT AGL THIS MORNING. CIGS WILL CLIMB TO AROUND
1300 FT AGL LATER TODAY...FALLING TO 400 TO 700 FT AGL THIS
EVENING. DRIZZLE WILL BE POSSIBLE THIS MORNING WITH VISBYS RANGING
FROM 1 TO 3SM. DRIZZLE WILL BE POSSIBLE ONCE AGAIN TONIGHT WITH
VISBYS AROUND 4SM .
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...BROOKS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
401 AM CDT TUE APR 7 2015
.SYNOPSIS...
ISSUED AT 400 AM CDT TUE APR 7 2015
H5 ANALYSIS FROM TONIGHT HAS A CLOSED LOW OVER NRN QUEBEC...WITH
A BROAD TROUGH EXTENDING SWD INTO NEW ENGLAND. FURTHER WEST...A
SECOND LOW WAS PRESENT OFF THE COAST OF SWRN OREGON WITH A TROUGH
EXTENDING SWD TO OFF THE COAST OF CENTRAL CALIFORNIA. AT THE
SURFACE...LOW PRESSURE WAS PRESENT OVER NORTHERN COLORADO...WITH A
STATIONARY FRONT EXTENDING ESE INTO WESTERN KS...THEN EAST
NORTHEAST INTO EAST CENTRAL KS. NORTH OF THIS FEATURE
TONIGHT...EASTERLY WINDS AND PLENTY OF LOW LEVEL MOISTURE HAVE
PUSHED INTO WESTERN AND NORTH CENTRAL NEBRASKA. IN ADDITION TO
AREAS OF FOG...OCCASIONAL DRIZZLE WAS REPORTED AT MOST OBSERVATION
STATIONS ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. WITH CLOUDY
SKIES PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL
NEBRASKA...TEMPERATURES RANGED FROM 36 AT VALENTINE TO 50 AT
BROKEN BOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE APR 7 2015
OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGE IS
PRECIPITATION CHANCES...ALONG WITH THE THREAT OF FOG AND DRIZZLE.
FOR THIS MORNING...LOW POPS WILL CONTINUE DUE TO A COMBINATION OF
OCCASIONAL DRIZZLE WHICH WILL BE HEAVY ENOUGH TO MEASURE...AND THE
THREAT FOR SHOWERS IN ASSOCIATION WITH A WEAK DISTURBANCE AND MID
LEVEL MOISTURE WHICH WILL CROSS THE SANDHILLS AND NORTHERN
NEBRASKA THIS MORNING. PRECIPITATION CHANCES WILL COME TO AN END
TEMPORARILY THIS AFTERNOON...AS THE BOUNDARY LAYER WARMS AND CIGS
LIFT...ALONG WITH MID LEVEL MOISTURE EXITING THE FORECAST AREA TO
THE EAST. FOR THE MOST PART...SKIES WILL REMAIN CLOUDY TODAY
ACROSS THE FORECAST AREA...AS WE REMAIN UNDER A THICK VEIL OF
STRATUS. THE EXCEPTION MAY BE ACROSS THE PANHANDLE COUNTIES...AS
THE LATEST HRRR AND NAM DO INDICATE SOME SCATTERING OUT OF CLOUDS
DURING PEAK HEATING THIS AFTERNOON. HOWEVER...THE MODELS INDICATED
A DECENT AMOUNT OF CLEARING FOR YESTERDAY WITH HEATING...WHICH FOR
THE MOST PART...DIDN/T MATERIALIZE. WITH THIS IN MIND...WENT
COOLER ON HIGHS TODAY THAN GUIDANCE...HEDGING ON CLOUDS REMAINING
ENTRENCHED ACROSS THE FORECAST AREA TODAY. CIGS WILL LOWER THIS
EVENING...WITH ANOTHER ROUND OF DRIZZLE AND FOG ACROSS THE
FORECAST AREA. FCST SOUNDINGS AND CROSS SECTIONS INDICATE A NEAR
SATURATED LAYER FROM THE SFC TO H85 TONIGHT...COLLOCATED WITH WEAK
OMEGA IN THIS LAYER AND VERY DRY CONDS ALOFT. DID GO AHEAD AND
INCREASE POPS OVERNIGHT AS SOME MID LEVEL MOISTURE LIFTS INTO THE
FORECAST AREA FROM THE SOUTHWEST...WHICH MAY LEAD TO LIGHT
PRECIPITATION IN ADDITION TO ANY DRIZZLE WHICH IS EXPECTED AS
WELL. LOWS TONIGHT WILL BE MILD GIVEN THE CLOUD COVER AND MOIST
BOUNDARY LAYER CONDS...WITH READINGS RANGING FROM THE UPPER 30S IN
THE FAR NORTH...TO LOWER TO MID 40S IN THE CENTRAL AND SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE APR 7 2015
FORECAST CONCERNS CONTINUE TO DEAL WITH DRIZZLE/FOG/RAIN CHANCES
THROUGH WEDNESDAY WHICH BRING UP THE CONCERN OF TEMPERATURES. THEN
FOCUS TURNS TO MAIN UPPER LEVEL SYSTEM MOVING ACROSS THE CENTRAL
PLAINS THURSDAY WHICH BRINGS CHANCES FOR RAIN/SNOW AND STRONG WINDS
TO THE FORECAST AREA. THE PATTERN THEN REMAINS ACTIVE AS THE LOCAL
AREA GETS IMPACTED BY SYSTEMS MOVING THROUGH BOTH THE NORTHERN AND
SOUTHERN STREAMS INTO THE FIRST PART OF NEXT WEEK.
FORECAST MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE
PERIOD...HOWEVER THERE HAVE BEEN SOME RUN TO RUN INCONSISTENCIES
WHICH HAS KEPT CONFIDENCE LOWER THAN WOULD BE DESIRED.
BEGINNING ON WEDNESDAY...THE PRIMARY UPPER LEVEL LOW WILL MOVE INTO
THE CENTRAL ROCKIES WITH A WEAK SHORTWAVE TROUGH EJECTING OUT AHEAD
OF THE MAIN SYSTEM DURING THE DAY WEDNESDAY. MODELS CONTINUE TO
DEVELOP QPF OVER MUCH OF NEBRASKA ON WEDNESDAY...HOWEVER LOOKING AT
MOISTURE PROFILES IN CROSS SECTIONS ACROSS THE AREA AND FORECAST
SOUNDINGS...THE MOISTURE REMAINS QUITE SHALLOW...BELOW 750MB. THE
LIFT ASSOCIATED WITH THE SHORTWAVE TROUGH DOES HELP PROVIDE LIFT
THROUGH THE COLUMN BUT WITH THE AIR ABOVE 750MB BEING SO EXTREMELY
DRY...THIS LIFT WILL NOT HAVE ANYTHING TO WORK WITH AND SO WILL HAVE
NO IMPACT ON THE FORECAST. IF THERE WOULD BE MOISTURE...COULD ARGUE
FOR NEEDING MENTION OF THUNDERSTORMS AS THE LAPSE RATES ARE QUITE
STEEP LEADING TO AT LEAST SOME INSTABILITY...BUT AGAIN NO MOISTURE
WILL PROHIBIT THE NEED FOR THUNDER MENTION. BACK TO THE LOW
LEVELS...THERE IS DECENT LIFT WITHIN THE SATURATED LAYER AND WITH
LIGHT EASTERLY WINDS CONTINUING THROUGH WEDNESDAY NIGHT...THE SLIGHT
UPSLOPE FLOW WILL HELP KEEP STRATUS/FOG/DRIZZLE POTENTIAL THROUGH
THE DAY. WITH THIS EXPECTATION...DON/T THINK TEMPERATURES WILL RISE
MUCH THROUGH THE DAY WEDNESDAY AND HAVE LOWERED HIGHS SUBSTANTIALLY.
THE FRONT WILL BE JUST SOUTH OF THE FORECAST AREA SO THERE MAY BE A
TIGHT GRADIENT WHERE CLOUDS/COLDER TEMPERATURES EXIST TO WHERE THERE
IS PLENTIFUL SUNSHINE AND HIGHS UP INTO THE 70S. BELIEVE THAT THIS
WILL BE SOUTH OF THE FORECAST AREA THROUGH.
THE WHOLE UPPER LEVEL SYSTEM CONTINUES TO MOVE EAST THROUGH THE DAY
THURSDAY...AND WHILE THEY ARE IN AGREEMENT WITH THE UPPER LOW
PASSING OVER THE REGION AND DUMPING SOME DECENT MOISTURE ACROSS THE
FORECAST AREA...THESE SOLUTIONS ARE DIFFERENT FROM PRIOR RUNS AS ALL
ARE NOW MOVING THE SYSTEM ACROSS THE AREA AS AN OPEN WAVE AND IN
TURNS MOVES IT ACROSS THE AREA FASTER...WITH PRECIPITATION ENDED BY
MID-DAY THURSDAY. THEY STILL PRODUCE QUITE A BIT OF QPF ON THE
NORTHWEST SIDE OF THE FORECAST AREA DESPITE MOVING ACROSS THE AREA
FASTER THAN WAS EARLIER THOUGHT. DID REMOVE MENTION OF
THUNDERSTORMS FOR WEDNESDAY NIGHT AND THURSDAY. THE FRONT WILL
REMAIN WELL SOUTH AND EAST OF THE LOCAL AREA AS THE SURFACE LOW
STAYS ACROSS KANSAS AS IT MOVES EASTWARD. THIS WILL KEEP THE
WARMER AIR...PLUS ANY MOISTURE ADVECTION/LIFT ALONG THE FRONT AWAY
FROM THE LOCAL AREA. AND...THE LOW LEVEL JET WILL BE WELL TO THE
EAST SO REALLY NOT CONCERNED ABOUT THUNDERSTORMS. THEN ON THURSDAY
AS THE SURFACE LOW ACROSS KANSAS TRANSITIONS INTO THE MISSISSIPPI
RIVER VALLEY THE PRESSURE GRADIENT WILL TIGHTEN...BRINGING STRONG
NORTHERLY WINDS TO THE FORECAST AREA. THIS WILL LEAD TO CONDITIONS
FEELING QUITE RAW AS APPARENT TEMPERATURES ARE LOOKING TO BE IN
THE 20S AND 30S. WITH THE COOLER AIR MOVING IN FROM THE NORTH...IT
IS LIKELY THAT THE PRECIPITATION WILL CHANGE OVER TO A RAIN/SNOW
MIX AND THEN OVER TO SNOW COMPLETELY OVER PARTS OF THE PANHANDLE.
DON/T THINK AMOUNTS WILL BE MUCH...BUT COULD SEE THE GROUND BECOME
WHITE FOR A SHORT PERIOD IN PLACES.
AGAIN AS THIS IS NOT MOVING THROUGH AS AN OPEN WAVE...IT WILL MOVE
THROUGH THE LOCAL AREA QUICKLY AND HAVE ENDED PRECIPITATION
CHANCES ABOUT 6 HOURS EARLIER THAN IN THE PRIOR FORECAST.
SHORTWAVE RIDGING BUILDS INTO THE CENTRAL PLAINS BRIEFLY FRIDAY
NIGHT...WHILE AN UPPER LOW IN THE SOUTHERN STREAM MOVES ACROSS THE
SOUTHERN CONUS AND NORTHERN MEXICO. MEANWHILE ANOTHER POTENT
SYSTEM MOVES INTO THE PACIFIC NORTHWEST. THESE SYSTEMS WILL BOTH
PROGRESS EASTWARD AND THERE IS SOME INDICATION THAT THEY MAY
ATTEMPT TO INTERACT EARLY NEXT WEEK WHICH COULD BRING ANOTHER WET
PERIOD TO THE FORECAST AREA FOR MONDAY AND TUESDAY. CONFIDENCE IS
NOT HIGH IN THIS OCCURRING RIGHT NOW SO WILL MAINTAIN LOW END
PRECIPITATION CHANCES FOR NOW.
ULTIMATELY WITH THE MORE ACTIVE PATTERN...WILL SEE MORE CHANCES
FOR PRECIPITATION...AND TEMPERATURES CLOSER TO NORMAL...ALTHOUGH
THERE WILL BE DAYS WITH HIGHER TEMPERATURES. HOWEVER THERE ARE NO
CURRENT INDICATIONS OF ANOTHER PERIOD OF WELL ABOVE NORMAL
TEMPERATURES FOR THE FORECAST AREA AT THIS TIME.
AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CDT MON APR 6 2015
LIFR CEILINGS CURRENTLY AT THE KLBF AND KVTN TERMINALS IS FORECAST
TO PERSIST UNTIL 15Z. VSBY WILL LIKELY RANGE NEAR 1SM -DZ BR AT
KVTN WHILE LOWERING TO 3SM -DZ BR AT KLBF. AFTER 15Z...CEILINGS
AND VSBYS WILL IMPROVE TO IFR...AND TO MVFR AFTER 18Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...BROOKS
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1145 PM CDT MON APR 6 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 330 PM CDT MON APR 6 2015
FORECAST CONCERNS CONTINUE TO BE ON AND OFF PRECIPITATION CHANCES
THROUGH THE WEEK...TEMPERATURES...AND SEVERE POTENTIAL.
THE LOW CLOUDS MOVED IN OVERNIGHT...WITH SOME FOG AND DRIZZLE.
THE 12Z OAX SOUNDING WAS SATURATED TO 890MB/2500FT WITH 0.49PWAT.
A FEW STORMS DEVELOPED AROUND BOONE AND ANTELOPE COUNTIES AND
LIFTED TOWARD WAYNE...WITH A STRONGER CLUSTER NEAR WASHINGTON AND
BURT THAT LIFTED NORTHEAST ACROSS HARRISON...MONONA...AND SHELBY
WITH OTHERS IN SOUTHWEST IOWA. THE 12Z H5 MAP SHOWED A WEAK
SHORTWAVE WITH THIS FEATURE IN THE SOUTHWEST FLOW ALOFT. THE H5
CLOSED LOW WAS STILL OFF THE WASHINGTON/OREGON COAST WITH A BROAD
TROF. THERE WAS A WEAK WAVE IN THE FLOW AT H7 APPROACHING THE
LOCAL FORECAST AREA AT 12Z...WITH ANOTHER WEAK WAVE OVER COLORADO
AND YET FARTHER SOUTHWEST OVER SOUTHERN CALIFORNIA. THE H85
PATTERN HAD AN H85 LOW NEAR LBF WITH SOUTHWEST FLOW AHEAD OF IT
AND A POCKET OF 7C DEWPOINTS. THE 10-12DEG. H85 DEWPOINTS WERE
OVER SOUTHERN MO AND ARKANSAS INTO EASTERN OK. THE H7 DEWPOINTS
WERE BETTER OVER TN/AL/MS. THE +20 DEG. C H85 TEMPS WERE OVER TX
WITH THE THERMAL RIDGE NOSING TOWARD OMA AT +12 DEG C.
THE LATEST VISIBLE SATELLITE IMAGERY WAS CLOUDY MOST AREAS...WITH
SOME BUMPY CLOUDS NEAR SD INTO IOWA AND A FEW THINNER SPOTS TOWARD
FAIRBURY... THE SURFACE FRONT WAS NEAR YANKTON TO ONL WITH A
DRYLINE NEAR KGBD KANSAS AND THE WARM FRONT FROM SALINA TO
WICHITA WITH THE CLEARING NEAR THERE. TEMPERATURES WERE IN THE
50S TO LOWER 60S WITH 70S AND 80S SOUTH OF THE WARM FRONT.THE LOCAL
RADAR WAS MAINLY DRY WITH ECHOES TO THE NORTHEAST INTO IOWA.
STILL SOME PATCHY FOG WITH VSBYS 2 TO 4 MILES IN SPOTS.
TONIGHT...SURFACE LOW PRESSURE TRIES TO ORGANIZE A LITTLE FARTHER
SOUTH IN KANSAS WITH NORTHEAST FLOW PREVAILING ACROSS THE FORECAST
AREA. ONE THING TO WATCH WILL BE A 50KT LOW LEVEL JET THAT
INCREASES ACROSS KANSAS INTO MISSOURI. THE 4KM WRF HAS A CLUSTER OF
STORMS DEVELOPING AND MOVING ACROSS NORTHERN KANSAS AND MISSOURI.
THE RAP HAS SHOWERS/TSTORMS IN SOUTHEAST NEBRASKA. IN OUR
FORECAST AREA...ANY PRECIPITATION LOOKS SPOTTY. DO HAVE HIGHER
POPS IN THE SOUTHEAST AND ALSO IN THE NORTHEAST BY MORNING. THE
GFS DOES INCREASE INSTABILITY TOWARD 1000J/KG IN THE SOUTHEAST. ANY
STRONGER STORMS COULD PRODUCE SOME HAIL. THERE MAY BE AN ENHANCED
BAND OF LIGHT PRECIP IN NORTHEAST NEBRASKA BY MORNING NEAR AN
INVERTED TROF AND SOME SHORTWAVE ENERGY PASSES THROUGH.
TUESDAY...THE SURFACE LOW PRESSURE TRACKS NORTHEAST TOWARD SOUTHEAST
NEBRASKA OR NORTHEAST KANSAS...WITH A H85 CIRCULATION OVER THE
FORECAST AREA. THE PRECIPITATION (SHOWERS AND ISOLATED
THUNDERSTORMS) SHOULD MOVE ACROSS THE FORECAST AREA DURING THE
DAY. TEMPERATURES AGAIN SHOULD BE IN THE 50S...WITH 60S CLOSER TO
THE SURFACE LOW FALLS CITY COULD BREAK OUT TO THE LOWER 70S.
TUESDAY NIGHT INTO WEDNESDAY NIGHT AHEAD OF THE STRONGER
SHORTWAVE...FLOW BACKS AND RE-FOCUSES THE LOW LEVEL FLOW WITH
PRECIPITATION CHANCES AGAIN ON THE INCREASE. THE BETTER COVERAGE
SHOULD BE THE SOUTHEAST PART OF THE FORECAST AREA. THE DAY 3 SPC
OUTLOOK HAS THIS AREA ALSO IN THE SLIGHT RISK AND THIS SEEMS
REASONABLE AND WILL BE DEPENDENT ON THE THE SURFACE LOW TRACK. THE
NAM/EC IS NOT QUITE AS FAR NORTH AT THE GFS. SO THIS WILL BE
SOMETHING TO KEEP AN EYE ON.
THE FRONT PUSHES THROUGH THURSDAY WITH THE UPPER LEVEL TROF TO THE
WEST. POST-FRONT SHOWERS WILL CONTINUE INTO THURSDAY WITH
NORTHWEST WINDS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM CDT MON APR 6 2015
THE STORM SYSTEM PULLS AWAY THURSDAY NIGHT. THERE IS A SMALL
CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY. ON AND OFF PRECIPITATION CHANCES CONTINUE INTO THE
WEEKEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 PM CDT MON APR 6 2015
WIDESPREAD IFR/LIFR CIGS AND IFR VSBYS WILL CONTINUE THROUGH ABOUT
18Z AS AREAS OF FOG AND DRIZZLE PERSIST. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN CENTRAL NEBRASKA
BEFORE 12Z...THEN SPREAD EAST TOWARD KOFK AND KLNK BY 12Z THEN
KOMA BY 14Z. EXPECT ABOUT A 6 HOUR PERIOD OF POTENTIAL SHOWERS AND
ISOLATED THUNDERSTORMS. SOME LIGHT IMPROVEMENT IN VSBYS AND CIGS
TO MVFR ARE IS POSSIBLE BETWEEN 18Z AND 00Z...THEN DETERIORATING
CONDITIONS TO IFR ARE FORECAST AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
205 AM EDT TUE APR 7 2015
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL KEEP THE WEATHER UNSETTLED FOR
MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
MAIN CHANGE THIS FORECAST RUN WAS TO PULL WAY BACK ON THE POPS
DURING THE SECOND HALF OF THE OVERNIGHT AND INTO TUESDAY MORNING.
MAIN WAVE OF PRECIP IS MOVING THROUGH THE FA ATTM AND IS PROGGED
TO WEAKEN AND DIMINISH AFTER MIDNIGHT. HRRR SEEMS TO HAVE A GOOD
HANDLE ON THE CURRENT TRENDS.
WE ARE SLOWLY INGESTING NEW MODEL/MOS DATA AFTER THE AWIPS II
INSTALL EARLIER, SO WE ARE A LITTLE LIMITED THIS EVENING ON WHAT
DATA WE CAN UTILIZE TO BLEND WITH.
1 PM UPDATE...
CLOUDS ARE BEGINNING TO ENCROACH FROM THE WEST ASSOCIATED WITH A
SERIES OF SHORTWAVES THAT ARE BEGINNING TO EJECT AND RACE EAST
OUT OF THE LARGE SCALE TROUGH OVER THE WESTERN US. THE FIRST
SHOWERS REACHING THE GROUND CAN BE SEEN OVER NORTHERN OHIO...AND
GUIDANCE SHOWS THE MOISTURE CONTINUING TO SURGE INTO THE REGION ON
A STRONG LOW LEVEL SWLY FLOW. GEFS/SREF SHOW PWATS RISING TO 1-2
ST DEV ABOVE NORMAL...CONTINUING INTO AT LEAST TUESDAY.
SREF SHOWS INCREASING CHANCES FOR RAIN EARLY TONIGHT...WITH
LIKELY TO CATEGORICAL POPS DEVELOPING BETWEEN 21-03Z. GEFS IS A
LITTLE LESS AGGRESSIVE BUT STILL SUGGESTS MOST IF NOT ALL
LOCATIONS WILL SEE MEASURABLE RAINS OVERNIGHT. OPERATIONAL RUNS
OF THE GFS/NAM ARE A LITTLE MORE DETAILED...HINTING AT SOME SORT
OF WAVE FORMING ALONG THE SLOW MOVING WARM FRONT AND BRINGING THE
INITIAL SURGE OF SHOWERS...WITH SOMEWHAT OF A LULL POSSIBLE FOR
THE SECOND HALF OF THE OVERNIGHT...ESPECIALLY OVER NORTHERN
AREAS.
LOWS WILL RANGE FROM THE CHILLY MID 30S OVER THE NORTH TO AROUND
50 IN THE FAR SOUTH.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
1 PM UPDATE...
COLD HIGH PRESSURE ANCHORED TO OUR NORTH AND THE WAVY BOUNDARY
TO OUR SOUTH WILL BE THE WEATHER DRIVERS FOR THE SHORT TERM. THE
GFS SUPPRESSES MOST OF THE PRECIP SOUTH TO AROUND THE NY/PA
BORDER BY LATER TUESDAY NIGHT EARLY WED AM...WHILE THE OPERATIONAL
NAM AND ECMWF SHOW LIGHT QPF BEING MORE GENEROUSLY SPREAD ABOUT
THE REGION.
THE GEFS IS A LITTLE LESS OPTIMISTIC THAN ITS OPERATIONAL
COUNTERPART WHILE THE SREF SUGGESTS THE NAM MAY BE TOO DRY. WILL
USE A BLEND OF POPS FOR THE PERIOD WHICH LENDS SMALL CONFIDENCE TO
ACTUALLY TRYING TO TIME WHEN THE BEST CHANCES FOR RAIN OR NO RAIN
WILL END UP BEING.
LOCAL RIVERS AND STREAMS ARE RUNNING HIGH...SO RAINFALL AMOUNTS
NEED TO BE MONITORED FOR POSSIBLE PROBLEMS. AT THIS POINT...NO
FLOODING IS EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
UPDATED 300 PM...BLENDED PREVIOUS FORECAST WITH THE LATEST MEDIUM
RANGE/WPC GUIDANCE WHICH RESULTED IN MINOR CHANGES. KEPT RISK FOR
FREEZING RAIN AROUND MID-WEEK WITH HIGHEST POPS ON DAY 5/FRI WITH
A SHARP COLD FRONTAL PASSAGE. OVERALL AN ACTIVE AND WET PERIOD
THROUGH THE END OF THE WEEK BEFORE THINGS DRY OUT BEHIND THE FRONT
THIS WEEKEND.
PREVIOUS DISCUSSION...
FORECAST ADJUSTED FOR TRENDS AND LATEST WPC
GUIDANCE. A COUPLE THINGS TO NOTE. ONE IS THAT STRONG HIGH
PRESSURE WILL BECOME CENTERED OVER FAR NORTHERN NEW ENGLAND-LOWER
ST. LAWRENCE SEAWAY LATE WEDNESDAY NIGHT INTO EARLY
THURSDAY...WHICH IS A GOOD SET UP FOR COLD AIR DAMMING. THERE
APPEARS TO BE SOME POTENTIAL FOR LIGHT FREEZING RAIN HIGHER
ELEVATIONS OF THE NORTHEASTERN ZONES DURING THAT TIME...THOUGH
PRECIP CHANCES ITSELF NOT THAT HIGH AND AMOUNTS IF ANY WOULD BE
VERY LIGHT. OTHERWISE THURSDAY- FRIDAY PERIOD LOOKS WET WITH MOIST
WARM AIR ADVECTION ALLOWING TEMPERATURES TO TREND ABOVE
CLIMATOLOGY INTO THE WEEKEND. OTHER THING THAT LATEST OPERATIONAL
GFS-ECMWF RUNS INCREASE CONFIDENCE IN LARGE SURFACE HIGH
DOMINATING SECOND HALF OF THE WEEKEND...FOR DRY AND MILD
CONDITIONS SUNDAY.
PREVIOUS DISCUSSION...
CLOSELY FOLLOWED WPC GUIDANCE. A WET PATTERN CONTINUES AS BROAD SW
FLOW ALOFT PREVAILS THROUGHOUT THE EXTENDED FORECAST PERIOD. THIS
PATTERN ALOFT ALLOWS FOR MULTIPLE SHORTWAVES WITHIN THE UPPER LVL
FLOW TO PASS OVER THE REGION BRINGING A CHANCE FOR RAIN SHOWERS
EACH DAY. ATTM... THE BEST CHANCE FOR RAIN SHOWERS OVER THE REGION
WILL BE THURS NIGHT THRU FRIDAY NIGHT. AS WE ARE AT THE TAIL END
OF WINTER... THERE IS STILL A CHANCE AT NIGHT THAT SOME OF THESE
SHOWERS COULD TRANSITION OVER TO SNOW. NO MAJOR ACCUMULATIONS ARE
EXPECTED THROUGH THE EXTENDED. TEMPERATURES DURING THIS TIME FRAME
ARE EXPECTED TO BE AT OR ABOVE THE SEASONAL NORM.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
AS HAS BEEN THE CASE THE LAST FEW DAYS...FORECAST REMAINS
CHALLENGING WITH VARYING GUIDANCE /SOME MUCH TOO
PESSIMISTIC/...FINE DETAILS...AND THUS LOWER CONFIDENCE THAN
USUAL. IN THE BIG PICTURE...A FRONTAL BOUNDARY IS SAGGING
SOUTHWARD THROUGH THE AREA AND THEN STALLING DURING THIS TAF
PERIOD. FAIRLY QUIET AT THE MOMENT WITH VERY SPORADIC SHOWERS NOW
AROUND KAVP...BUT WAVES MOVING ALONG THE FRONT WILL CAUSE
ADDITIONAL SHOWERS TO DEVELOP DURING THE DAY...ESPECIALLY KITH-
KBGM-KELM-KAVP. AS COOLER AIR CONTINUES TO ADVECT IN...LINGERING
MOISTURE WILL CONDENSE AND BECOME TRAPPED UNDER SHALLOW
INVERSION...WHICH ALONG WITH MOISTURE FROM PASSING SHOWERS SHOULD
ALLOW MVFR CIGS TO DEVELOP KITH-KBGM-KAVP-KELM...EVENTUALLY FUEL
ALT. IFR NOT OUT OF THE QUESTION /KBGM BEST CHANCE...KAVP
POSSIBLE AS WELL LATE DUE TO MOISTURE AND FAVORABLE LIGHT
NORTHEAST WIND/. KRME-KSYR APPEAR TO BE MAINLY VFR THIS
PERIOD...BUT EARLY THIS MORNING WE WILL HAVE TO WATCH FOR
POTENTIAL THIN OVC LAYER NEAR FUEL ALT-TO-MVFR LEVEL...BEFORE
DRIER LOW LEVEL AIR ELIMINATES THE POSSIBILITY. NOT CONFIDENT
ENOUGH TO INCLUDE IN TAF AT THIS TIME. WINDS GENERALLY VARIABLE TO
LIGHT N/NE/E...SEE TAFS FOR SPECIFICS.
.OUTLOOK...
LATE TUE NGT-FRI...BUSY PATTERN WITH WAFFLING FRONTAL BOUNDARY
REMAINING IN THE VICINITY...AND WAVES OF SHRA PLUS ASSOCIATED
RESTRICTIONS MOVING ALONG IT. SLIGHT CHC TSRA AS WELL FRI.
SAT...MAINLY VFR BUT ISOLATED -SHRA STILL POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...DJP
SHORT TERM...
LONG TERM...
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT TUE APR 7 2015
.SYNOPSIS...
UNSEASONABLY WARM AND HUMID WEATHER IS EXPECTED OVER THE NEXT FEW
DAYS WITH WEAK HIGH PRESSURE WELL OFF THE COAST. THERE IS A RISK
OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH SATURDAY WITH THE
HIGHEST POTENTIAL TODAY AND FRIDAY NIGHT INTO SATURDAY. A BACKDOOR
COLD FRONT WILL MAKE A QUICK VISIT LATE WEDNESDAY NIGHT. IT WILL
REMAIN WARM AND HUMID THROUGH FRIDAY. A COLD FRONT WILL USHER IN
SEASONABLE TEMPERATURES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...SATELLITE AND RADAR SUGGEST THE UPPER
DISTURBANCE IS OFFSHORE. CLOUDS HAVE FRAGMENTED A BIT INLAND
ALTHOUGH THE INSOLATION IS CAUSING DESTABILIZATION OF THE
BOUNDARY LAYER AND NEW CUMULUS TO FORM QUITE QUICKLY. FOR THIS
REASON SKY COVER WILL PROBABLY AVERAGE MOSTLY CLOUDY THROUGH THE
AFTERNOON. RADAR SHOWS SPRINKLES/SHOWERS ARE VERY FEW AND FAR
BETWEEN...AND I HAVE DOUBTS WE`LL SEE ANYTHING SUBSTANTIAL THROUGH
LATE AFTERNOON. HIGHS HAVE BEEN ADJUSTED DOWNWARD BY A DEGREE OR
TWO FOR MOST AREAS. DISCUSSION FROM 1000 AM FOLLOWS...
A WEAK UPPER LEVEL DISTURBANCE IS PASSING ACROSS THE EASTERN
CAROLINAS CURRENTLY. THIS FEATURE SHOWS UP QUITE WELL IN WATER
VAPOR IMAGERY...BUT UNFORTUNATELY IT HAS OUTRUN DEEP MOISTURE AND
SHOWER ACTIVITY IS DRYING UP AS IT APPROACHES THE COAST. I HAVE
KEPT IN SMALL POPS (20-40 PERCENT) FOR THE NEXT COUPLE OF HOURS
ALONG THE COAST BUT HAVE LITTLE FAITH ANYONE WILL SEE MORE THAN AN
ADDITIONAL .01 OR .02 INCHES BEFORE THIS ACTIVITY EITHER
COMPLETELY DISSIPATES OR MOVES OFFSHORE.
BEHIND THIS DISTURBANCE IMPLIED NET DOWNWARD ATMOSPHERIC MOTION
WILL PROBABLY LEAD TO SEVERAL HOURS OF PARTLY CLOUDY SKIES WITH
TEMPERATURES SOARING INTO THE LOWER 80S INLAND...EXCEPT 5-10
DEGREES COOLER NEAR THE COAST GIVEN THE COOL ONSHORE FLOW FROM
OCEAN WATER TEMPERATURES ONLY IN THE LOWER 60S. GIVEN DEWPOINTS
NOW RECOVERING WELL INTO THE 60S I EXPECT TO SEE A HEALTHY CUMULUS
DECK FILL IN. ANOTHER WEAK UPPER LEVEL DISTURBANCE WILL APPROACH
FROM THE NORTHWEST THIS EVENING...POSSIBLY ACCOMPANIED BY A LINE
OF SHOWERS AND THUNDERSTORMS. WHILE I WOULD LOVE TO SHOW RAIN WITH
THIS FEATURE MAKING IT DOWN INTO WILMINGTON (WHERE IT`S BEEN 10
DAYS WITHOUT MEASURABLE RAIN NOW) IT IS HARD TO FIND SUPPORT FOR
MORE THAN 30-40 POPS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...WEDNESDAY BRINGS UNSEASONABLE WARMTH AND
HUMIDITY. IN FACT, CONSIDERABLE INSTABILITY IS FORECAST TO DEVELOP
AWAY FROM THE STABILIZING EFFECT OF THE OCEAN. SO WE HAVE TWO OF
THE THREE INGREDIENTS FOR THUNDERSTORMS IN PLACE. THE THIRD
HOWEVER, LIFT, MAY BE A BIT LACKING. IN PART THIS MAY HINGE UPON
HOW STORMY TUESDAY ENDS UP AS AN ACTIVE DAY COULD LEAVE BEHIND
SOME OUTFLOW BOUNDARIES. THERE WILL CERTAINLY BE SOME UNEVENNESS
IN THE CLOUD COVER SO SOME DIFFERENTIAL HEATING BOUNDARIES MAY
DEVELOP AS WELL. WHERE POPS TEND TO FOCUS WEDNESDAY NIGHT (ALBEIT
CAPPED AT 20 FOR NOW) WILL DEPEND ON HOW FAR SOUTH A BACKDOOR COLD
FRONT SINKS. IT APPEARS THAT A FEW THUNDERSTORMS WILL TRAIN
EASTWARD ALONG ITS LENGTH, BUT NOT ALL MODELS ARE CONVINCED THAT
IT GETS TOO FAR INTO OUR AREA, IF AT ALL. REGARDLESS, THIS
BOUNDARY THEN HIGHTAILS IT BACK TO THE NORTH ON THURSDAY. THIS
ONCE AGAIN LEAVES THE AREA IN A SOUTHWESTERLY WARM AND MOIST FLOW
REGIME. INSTABILITY WILL ONCE AGAIN DEVELOP AND SOME ISOLATED
THUNDERSTORMS WILL BE POSSIBLE. THE ONSHORE FLOW COMPONENT WILL BE
A LITTLE MORE PRONOUNCED POSSIBLY KEEPING THE IMMEDIATE COAST
RAIN-FREE. TEMPERATURES WILL STILL BE ABOVE NORMAL BUT PERHAPS A
FEW DEGREES TEMPERED FROM THE WEDNESDAY HIGHS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY... WE REMAIN IN THE WARM AND HUMID
PRE-FRONTAL REGIME ON FRIDAY BUT COLD FRONT WILL BE APPROACHING.
THIS SHOULD BE SUFFICIENT TO TOUCH OFF SCATTERED SHOWERS AND
THUNDERSTORMS THAT WILL CONTINUE INTO THE NIGHTTIME WITH ACTUAL
FROPA. THE ACTUAL PASSAGE OF THE FRONT WILL BE RATHER GRADUAL
ESPECIALLY SINCE IT WILL BE CHANGING ITS ORIENTATION AS IT ALIGNS
MORE WITH THE CONTINUED LOW AMPLITUDE ALOFT. SUNDAY AND MONDAY
WILL FEATURE A SLIGHT COOLDOWN BACK TO CLIMATOLOGICAL
TEMPERATURES. SUNDAY APPEARS TO BE RAIN-FREE WHEREAS SOME MOISTURE
MAY RETURN SUFFICIENTLY ON MONDAY FOR SOME LOW RAIN CHANCES.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...ISOLATED SHOWERS THIS AFTERNOON MAINLY BETWEEN THE INLAND
AND COASTAL TERMINALS. MVFR CIGS WILL RISE TO VFR MID-LATE AFTERNOON.
AT KCRE/KMYR THERE REMAIN A POTENTIAL FOR MVFR VSBYS IN BR WITH SCATTERED
STRATUS AROUND 500 FEET UNTIL MID-AFTERNOON AS A NEARLY SATURATED AIRMASS
MOVES ONSHORE.
THERE IS A POTENTIAL FOR SHOWERS/ISOLATED THUNDERSTORMS THIS EVENING WITH
BEST THUNDERSTORM POTENTIAL AT KFLO/KLBT. AFTER MIDNIGHT Z MVFR
VSBYS/-RA BR WILL DEVELOP. EXPECTED CLOUD COVER SHOULD LIMIT
POTENTIAL FOR IFR. VFR EXPECTED AFTER SUNRISE WITH LIGHT WNW
WINDS.
EXTENDED OUTLOOK...VFR. CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY...BEST
CHANCE FOR PRECIPITATION IS FRIDAY NIGHT INTO SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...WINDS ARE STILL BACKED AROUND MORE EAST TO
SOUTHEASTERLY THAN MODELS INDICATED. LATEST RUC AND HRRR WIND
FIELDS ARE TOO NOISY TO USE SO I HAVE MANUALLY ADJUSTED WIND
DIRECTIONS COUNTERCLOCKWISE. STRONGEST WIND SPEEDS ARE NEAR AND
NORTH OF THE WEAK LOW OUT BEYOND FRYING PAN SHOALS...12-15 KT
NORTH OF CAPE FEAR...WITH 10 KT OR LESS FOR THE SC WATERS.
DISCUSSION FROM 1000 AM FOLLOWS...
SYNOPTIC HIGH PRESSURE IS WELL OFF THE COAST. WHAT APPEARS TO BE
MAINLY A MID-LEVEL CIRCULATION HAS FORMED WITHIN A LARGE AREA OF
RAIN AND EMBEDDED CONVECTION OFF THE COAST THIS MORNING. ALTHOUGH
I HAVEN`T SEEN MUCH INCREASE IN WIND VELOCITY...WIND DIRECTIONS
HAVE BEEN PERTURBED COUNTERCLOCKWISE BY THIS FEATURE WITH EAST
FLOW ALONG THE CAPE FEAR COAST BACKING TO NORTHEASTERLY ALONG THE
GRAND STRAND DOWN TOWARD GEORGETOWN.
THIS FEATURE SHOULD PUSH OFFSHORE THIS AFTERNOON WITH THE SYNOPTIC
SOUTHERLY WIND REESTABLISHING ITSELF. A WEAK SEABREEZE CIRCULATION
SHOULD AUGMENT THIS WIND...WITH SOUTH WINDS GENERALLY IN THE 10-15
KT RANGE THROUGH THIS EVENING. ONCE ANY LINGERING MORNING RAIN
CLEARS THE CAPE FEAR REGION...GENERALLY DRY CONDITIONS ARE
EXPECTED ACROSS THE COASTAL WATERS. THE APPROACH OF ANOTHER WEAK
DISTURBANCE THIS EVENING MAY GENERATE SOME MORE SHOWERS AND
THUNDERSTORMS...BUT THESE MAY HAVE TROUBLE MAKING IT DOWN BEYOND
THE COASTLINE DUE TO COOLER AND MORE STABLE AIR STREAMING ONSHORE
ACROSS THE COLD NEARSHORE WATER TEMPS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY... WEDNESDAY WILL BRING LIGHT SOUTHWESTERLY
WINDS AROUND HIGH PRESSURE IN THE WESTERN ATLANTIC. THIS HIGH WILL
BE QUITE WEAK AND POORLY DEFINED, NOT THE STALWART BERMUDA HIGH
OFTEN SEEN IN THE WARMER MONTHS. THIS IS WHY WINDS WILL BE SO
LIGHT AND SWELL ENERGY LACKING. SOME FORECAST UNCERTAINTIES CROP
UP WEDNESDAY NIGHT INTO THURSDAY MORNING FOR OUR NORTHERN WATERS.
A BACKDOOR COLD FRONT WILL SAG SOUTHWARD CLOSE TO OR PARTIALLY
INTO THE REGION, DEPENDING ON MODEL CHOICE. CURRENT THINKING IS
THAT A NORTHEASTERLY FLOW MAY BRIEFLY AFFECT NORTHERN ZONES BUT
THIS BOUNDARY WILL RETREAT BACK NORTHWARD ON THURSDAY. A RETURN TO
LIGHT SOUTH TO SOUTHWESTERLY FLOW EXPECTED AS SEAS REMAIN MINIMAL.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...FRIDAY BRINGS A CONTINUATION OF THE QUIET
CONDITIONS SEEN THROUGH MOST OF THE SHORT TERM. THAT IS, A LIGHT S
TO SWRLY FLOW AND SEAS NO HIGHER THAN 3 FT. WE MAY ADD A FEW KNOTS
OF WIND FRIDAY NIGHT AND SW WILL BECOME MORE LIKELY THAN S DUE TO
A COLD FRONT APPROACHING FROM THE NW. FROPA ITSELF MAY BE A LITTLE
LAZY ON SATURDAY AS THE BOUNDARY DECELERATES AND CHANGES
ORIENTATION TO A MORE WEST-TO-EAST NATURE AS IT TRIES TO ALIGN
WITH THE FLOW ALOFT. EVENTUALLY A NEERLY FLOW WILL OVERSPREAD THE
WATERS ON SATURDAY. THE CHANGE IN DIRECTION MAY SHORTEN THE
DOMINANT PERIOD BUT ANY UPTICK IN DOMINANT WAVE HEIGHT SHOULD BE
VERY MINOR.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...RJD/TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT TUE APR 7 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS
MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER
TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH
WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD
INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH
OF THE AREA ON THURSDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 250 AM TUESDAY...
AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE
IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND
RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING
TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER
CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY
NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS
CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN
ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE
SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON...
ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500-
750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND
25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION
MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND
THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW
EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO
AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION AND ITS ACCOMPANYING
STRONG BUT WANING UPPER DIVERGENCE BRINGS IT INTO WRN NC EARLY THIS
EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS.
WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO
HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID
EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE
FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO
DROP BACK TO A 10-20% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING
AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-UPPER LEVELS
SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE
PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW
TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS.
WARM LOWS TONIGHT OF 59-65 WITH AREAS OF FOG. -GIH
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
WE`LL BE FIRMLY IN THE WARM SECTOR WED WITH PW VALUES HOLDING NEAR
200% OF NORMAL. WE SHOULD INITIALLY SEE WEAK SUBSIDENCE BEHIND THIS
EVENING`S WAVE AS IT SHIFTS OFF THE NC/VA COAST... HOWEVER AS IT
INDUCES WEAK BUT IMPORTANT CYCLOGENESIS JUST OFF THE COAST... THE
FLOW AROUND THIS LOW WILL HELP DRAW THE SURFACE FRONTAL ZONE TO OUR
NORTH (NOW EXTENDING ROUGHLY WEST-EAST JUST NORTH OF THE OH VALLEY
INTO THE NYC AREA) TO THE SOUTH INTO VA/NC LATE WED. THE GFS REMAINS
THE MOST BULLISH IN PUSHING THE FRONTAL ZONE WELL SOUTHWARD INTO THE
SRN CWA... WHEREAS THE NAM (WITH ITS MORE-OFFSHORE LOW) AND THE
ECMWF (MUCH WEAKER LOW) HOLD IT NORTH OF THE NC/VA BORDER OR PERHAPS
DIP IT JUST BARELY INTO OUR NE CWA. HAVE OPTED TO FAVOR THE LATTER
SOLUTION BASED ON THE FAR-NORTH POSITION OF THE PARENT HIGH/COLD AIR
AND LOW CONFIDENCE IN THE GFS`S STRONGER AND MORE WESTWARD LOW.
FORECAST MUCAPE PEAKS AT 750-1500 J/KG ON THE GFS AND 1500-2500 J/KG
ON THE NAM WED AFTERNOON... BUT WITH CONTINUED MODEST DEEP LAYER
SHEAR OF 25-30 KTS. GIVEN THE MOISTURE IN PLACE THOUGH... WILL RAMP
UP POPS TO GOOD CHANCE FOR AFTERNOON INTO EARLY EVENING... TRENDING
BACK DOWN TO 20-30% CHANCE FROM LATE EVENING ONWARD THROUGH WED
NIGHT WITH LOWERING INSTABILITY... BUT WE MAY STILL SEE SCATTERED
SHOWERS CONCENTRATED NEAR AND JUST SOUTH OF THE FRONTAL ZONE... OVER
NRN CWA. VERY WARM THICKNESSES SUPPORT HIGHS OF 77-85 (NE TO SW).
ANOTHER NIGHT OF WARM LOWS IN THE UPPER 50S TO LOWER 60S... WITH
REDUCED CONFIDENCE... AS A FARTHER-SOUTH PENETRATION OF THE FRONT
WOULD MEAN COOLER TEMPS IN THE NE CWA. -GIH
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 255 AM MONDAY...
STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG
TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL
PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE
NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT
MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD
WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE
CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO
THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW
FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE
LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS
LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH
THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING
IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN
EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE
MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION
IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE.
MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A
COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH
SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS
FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY
BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH
IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME
INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE
POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE
DAY 5 CONVECTIVE OUTLOOK FROM SPC.
SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT
WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH
SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW
PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER
CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY
UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY
AFTERNOON.
TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO
MID 80S AND LOWS IN THE MID 50S TO MID 60S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 650 AM TUESDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING
TO MVFR/IFR THIS MORNING... THEN MVFR CIGS ARE EXPECTED THIS
AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE
FORECAST PERIOD.
AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS
MORNING. A PASSING DISTURBANCE ALOFT THIS MORNING WILL LEAD TO A
PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST FEW HOURS OF THE
FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO BE
PREDOMINANTLY MVFR/IFR THROUGH MID MORNING. RECOVERY TO MAINLY MVFR
CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT
OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER
DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR
VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID
EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE
DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW
CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS IN
THE LAST 6-9 HOURS OF THE TAF VALID PERIOD.
LOOKING BEYOND 12Z WED MORNING: IFR/LIFR CONDITIONS EARLY WED SHOULD
LIFT TO MVFR BY NOON AND TO VFR DURING THE EARLY-MID AFTERNOON.
HEATING AND INSTABILITY WILL LEAD TO SCATTERED SHOWERS AND A FEW
STORMS WED AFTERNOON WITH POTENTIAL SUB-VFR CONDITIONS.
REDEVELOPMENT OF IFR/LIFR FOG/STRATUS IS POSSIBLE WED NIGHT INTO THU
MORNING. ADDITIONAL SHOWERS/STORMS THU AFTERNOON MAY BRING BRIEF SUB-
VFR CONDITIONS. MORE WIDESPREAD AND ORGANIZED SHOWERS AND STORMS ARE
ANTICIPATED AHEAD OF A COLD FRONT APPROACHING LATE FRI. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT TUE APR 7 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS
MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER
TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH
WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD
INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH
OF THE AREA ON THURSDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 250 AM TUESDAY...
AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE
IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND
RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING
TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER
CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY
NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS
CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN
ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE
SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON...
ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500-
750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND
25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION
MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND
THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW
EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO
AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION AND ITS ACCOMPANYING
STRONG BUT WANING UPPER DIVERGENCE BRINGS IT INTO WRN NC EARLY THIS
EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS.
WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO
HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID
EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE
FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO
DROP BACK TO A 10-20% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING
AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-UPPER LEVELS
SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE
PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW
TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS.
WARM LOWS TONIGHT OF 59-65 WITH AREAS OF FOG. -GIH
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
WE`LL BE FIRMLY IN THE WARM SECTOR WED WITH PW VALUES HOLDING NEAR
200% OF NORMAL. WE SHOULD INITIALLY SEE WEAK SUBSIDENCE BEHIND THIS
EVENING`S WAVE AS IT SHIFTS OFF THE NC/VA COAST... HOWEVER AS IT
INDUCES WEAK BUT IMPORTANT CYCLOGENESIS JUST OFF THE COAST... THE
FLOW AROUND THIS LOW WILL HELP DRAW THE SURFACE FRONTAL ZONE TO OUR
NORTH (NOW EXTENDING ROUGHLY WEST-EAST JUST NORTH OF THE OH VALLEY
INTO THE NYC AREA) TO THE SOUTH INTO VA/NC LATE WED. THE GFS REMAINS
THE MOST BULLISH IN PUSHING THE FRONTAL ZONE WELL SOUTHWARD INTO THE
SRN CWA... WHEREAS THE NAM (WITH ITS MORE-OFFSHORE LOW) AND THE
ECMWF (MUCH WEAKER LOW) HOLD IT NORTH OF THE NC/VA BORDER OR PERHAPS
DIP IT JUST BARELY INTO OUR NE CWA. HAVE OPTED TO FAVOR THE LATTER
SOLUTION BASED ON THE FAR-NORTH POSITION OF THE PARENT HIGH/COLD AIR
AND LOW CONFIDENCE IN THE GFS`S STRONGER AND MORE WESTWARD LOW.
FORECAST MUCAPE PEAKS AT 750-1500 J/KG ON THE GFS AND 1500-2500 J/KG
ON THE NAM WED AFTERNOON... BUT WITH CONTINUED MODEST DEEP LAYER
SHEAR OF 25-30 KTS. GIVEN THE MOISTURE IN PLACE THOUGH... WILL RAMP
UP POPS TO GOOD CHANCE FOR AFTERNOON INTO EARLY EVENING... TRENDING
BACK DOWN TO 20-30% CHANCE FROM LATE EVENING ONWARD THROUGH WED
NIGHT WITH LOWERING INSTABILITY... BUT WE MAY STILL SEE SCATTERED
SHOWERS CONCENTRATED NEAR AND JUST SOUTH OF THE FRONTAL ZONE... OVER
NRN CWA. VERY WARM THICKNESSES SUPPORT HIGHS OF 77-85 (NE TO SW).
ANOTHER NIGHT OF WARM LOWS IN THE UPPER 50S TO LOWER 60S... WITH
REDUCED CONFIDENCE... AS A FARTHER-SOUTH PENETRATION OF THE FRONT
WOULD MEAN COOLER TEMPS IN THE NE CWA. -GIH
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 255 AM MONDAY...
STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG
TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL
PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE
NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT
MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD
WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE
CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO
THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW
FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE
LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS
LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH
THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING
IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN
EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE
MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION
IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE.
MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A
COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH
SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS
FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY
BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH
IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME
INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE
POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE
DAY 5 CONVECTIVE OUTLOOK FROM SPC.
SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT
WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH
SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW
PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER
CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY
UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY
AFTERNOON.
TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO
MID 80S AND LOWS IN THE MID 50S TO MID 60S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM TUESDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING
TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED
THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE
FORECAST PERIOD (AFTER 03Z TONIGHT).
AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS
MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO
A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF
THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO
MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR
CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT
OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER
DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR
VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID
EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE
DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW
CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS
TOWARD THE END OF THE TAF VALID PERIOD.
LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE
EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON
AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY
WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH
POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS
IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS
THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD
AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD
FRONT APPROACHING LATE FRI. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
254 AM EDT TUE APR 7 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS
MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER
TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH
WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD
INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH
OF THE AREA ON THURSDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 250 AM TUESDAY...
AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE
IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND
RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING
TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER
CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY
NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS
CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN
ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE
SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON...
ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500-
750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND
25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION
MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND
THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW
EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO
AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION BRINGS IT INTO WRN NC
EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES
ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE
RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO
EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO
UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP
CHANCES TO DROP BACK TO A 20-30% CHANCE AT MOST OVERNIGHT WITH LOSS
OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-
UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED
BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL
SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY
OF CLOUDS. WARM LOWS TONIGHT OF 59-65. -GIH
&&
.SHORT TERM / /...
AS OF 345 PM MONDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 255 AM MONDAY...
STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG
TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL
PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE
NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT
MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD
WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE
CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO
THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW
FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE
LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS
LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH
THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING
IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN
EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE
MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION
IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE.
MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A
COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH
SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS
FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY
BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH
IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME
INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE
POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE
DAY 5 CONVECTIVE OUTLOOK FROM SPC.
SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT
WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH
SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW
PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER
CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY
UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY
AFTERNOON.
TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO
MID 80S AND LOWS IN THE MID 50S TO MID 60S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM TUESDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING
TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED
THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE
FORECAST PERIOD (AFTER 03Z TONIGHT).
AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS
MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO
A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF
THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO
MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR
CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT
OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER
DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR
VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID
EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE
DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW
CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS
TOWARD THE END OF THE TAF VALID PERIOD.
LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE
EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON
AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY
WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH
POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS
IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS
THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD
AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD
FRONT APPROACHING LATE FRI. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EDT TUE APR 7 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS
MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER
TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH
WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD
INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH
OF THE AREA ON THURSDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 250 AM TUESDAY...
AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE
IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND
RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING
TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER
CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY
NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS
CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN
ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE
SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON...
ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500-
750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND
25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION
MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND
THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW
EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO
AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION BRINGS IT INTO WRN NC
EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES
ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE
RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO
EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO
UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP
CHANCES TO DROP BACK TO A 20-30% CHANCE AT MOST OVERNIGHT WITH LOSS
OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-
UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED
BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL
SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY
OF CLOUDS. WARM LOWS TONIGHT OF 59-65. -GIH
&&
.SHORT TERM / /...
AS OF 345 PM MONDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 305 PM MONDAY...
THE MODELS HAVE BEEN FLIP-FLOPPING ON THE SOUTHWARD PENETRATION OF A
COLD FRONT DOWN THE EASTERN SEABOARD INTO THE MID-ATLANTIC STATES
WEDNESDAY INTO THURSDAY. THIS TREND CONTINUED WITH THE 12Z/MODEL
SUITE. THIS HAS FORECAST IMPLICATIONS BOTH DAYS IN TERMS OF MAX
TEMPERATURES/CLOUDS/INSTABILITY/AND CONVECTIVE CHANCES.
SINCE THE CENTER OF THE STRONG SURFACE HIGH PRESSURE IS FORECAST TO
BE A BIT NORTH AND NORTHEAST OF THE FAVORED POSITION FOR DAMMING
DEEP INTO NC/SC PIEDMONT DAMMING REGION... AND WITH THE UPPER RIDGE
FORECAST TO SLOWLY BUILD EASTWARD ACROSS THE SOUTHEASTERN STATES
DURING THE SAME TIME... THE COLD FRONT MAY NOT BE ABLE TO REACH AS
FAR SOUTH AS THE 12Z/OPERATIONAL GFS DEPICTS (INTO NORTHERN SC BY
12Z/THU). HOWEVER... THIS TIME OF YEAR THE WATER TEMPERATURES ARE
STILL COLD NORTH OF CAPE HATTERAS... AND THEY ARE ABNORMALLY COLD
THIS YEAR DUE TO THE COLD WINTER OVER THE NE STATES. WE SUGGEST THAT
THE 12Z/NAM MAY BE THE BEST COMPROMISE GIVEN THE ABOVE DATA... AS
THE 12Z/EC MAY NOT BE FAR ENOUGH SOUTH. THEREFORE... THE MORE
SOUTHWARD PLACEMENT OF THE FRONT IS EXPECTED... WHICH WOULD PLACE
THE COLD FRONT NEAR THE NC/VA BORDER WEDNESDAY AFTERNOON... THEN
DIPPING SOUTHWARD TO NEAR HKY TO FAY TO ILM BY AROUND 12Z/THURSDAY.
THE AIR MASS AND BOUNDARY LAYER OUT AHEAD OF THE FRONT WILL BE
MODESTLY UNSTABLE... ESPECIALLY DURING THE AFTERNOON AND EARLY
EVENING. THE HIGHS ARE FORECAST TO REACH INTO THE UPPER 70S INTO THE
LOWER 80S... WITH DEW POINTS AROUND 60. HOWEVER.. THE COLD FRONT AND
ASSOCIATED LOW LEVEL CONVERGENCE SHOULD ARRIVE IN THE NORTHERN ZONES
DURING THE MID TO LATE AFTERNOON... AND THEN IN THE WESTERN AND
SOUTHERN ZONES IN THE EVENING OR LATER. THUS... THE NAM POP IN THE
HIGH CHANCE RANGE FOR SHOWERS AND THUNDERSTORMS NORTH AND EAST
BETWEEN 18Z-00Z SEEMS THE BEST FIT. THE CHANCE OF SHOWERS AND
THUNDERSTORMS SHOULD PUSH SOUTHWARD WITH THE FRONT INTO THE WESTERN
AND SOUTHERN ZONES WED EVENING.
THE CHANCE OF SHOWERS SHOULD CONTINUE WED NIGHT AND THURSDAY... BUT
CHANCES OF THUNDER APPEAR LOW GIVEN THE EXPECTED INCREASE IN THE
COOLER/STABLE/CLOUDY LOW LEVELS NORTH OF THE FRONT. THE FRONT SHOULD
EITHER BECOME DIFFUSE OR SLIP BACK NORTH AS A WARM FRONT ON THURSDAY
INTO THURSDAY NIGHT... ALLOWING FOR A SLIM CHANCE OF SHOWERS TO
CONTINUE WITH LIMITED UPPER SUPPORT. LOWS GENERALLY IN THE MID 50S
TO NEAR 60 NE... AND LOWER TO MID 60S SOUTH. HIGHS THURSDAY SHOULD
HOLD IN THE 70S (BUT IF FRONT PUSHES BACK NORTH QUICKER THAN
EXPECTED... HIGHS IN THE LOWER TO MID 80S MAY RETURN A DAY SOONER...
ESPECIALLY ACROSS THE SOUTH.
FRIDAY INTO SATURDAY... THE STORM TRACK STILL IS EXPECTED TO OUR
WEST AND NORTH... FINALLY DRAGGING A COLD FRONT INTO AND THROUGH THE
REGION LATE FRIDAY INTO SATURDAY MORNING. A BAND OF SHOWERS AND
SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONT OR A PRE-
FRONTAL TROUGH (HIGHEST CHANCES LATE FRIDAY INTO EARLY SATURDAY).
FRIDAY SHOULD BE VERY WARM WITH HIGHS IN THE LOWER TO MID 80S.
A TURN TO COOLER AND DRIER CONDITIONS ARE EXPECTED BEHIND THE FRONT
LATER IN THE WEEKEND INTO MONDAY. LOWS IN THE UPPER 40S AND 50S.
HIGHS IN THE 70S SUNDAY AND MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM TUESDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING
TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED
THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE
FORECAST PERIOD (AFTER 03Z TONIGHT).
AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS
MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO
A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF
THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO
MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR
CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT
OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER
DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR
VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID
EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE
DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW
CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS
TOWARD THE END OF THE TAF VALID PERIOD.
LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE
EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON
AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY
WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH
POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS
IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS
THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD
AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD
FRONT APPROACHING LATE FRI. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1211 AM CDT TUE APR 7 2015
.UPDATE...
ISSUED AT 1210 AM CDT TUE APR 7 2015
THE LATEST WATER VAPOR IMAGERY AND RADAR SHOWS SEVERAL MOISTURE
PLUMES INCREASING WITH TIME...FROM NORTHWEST THROUGH NORTH
CENTRAL NORTH DAKOTA...AND ACROSS CENTRAL/EASTERN MONTANA SOUTH
INTO WYOMING AND WESTERN SOUTH DAKOTA. LARGE SCALE ASCENT BEING
MAXIMIZED IN EASTTERN MONTANA AND AREAS SOUTH...AHEAD OF A
NEGATIVELY TILTED 700MB-500MB SHORTWAVE TROUGH LOCATED IN NORTH
CENTRAL MONTANA. BOWMAN RADAR NOW SHOWING INCREASING REFLECTIVITY`S
UPSTREAM...WHICH COINCIDES WITH THE CURRENT FORECAST OVERNIGHT AS
PRECIPITATION CHANCES INCREASE. STRONGEST LIFT PER OMEGA FIELD
OCCURS FROM NEAR 12Z TUESDAY WEST...TRANSLATING EAST THROUGH 18Z.
CATEGORICAL POPS CURRENTLY IN THE FORECAST LOOKS GOOD. WITH
OVERALL POPS ON TRACK...NO CHANGES WITH THIS FORECAST UPDATE.
UPDATE ISSUED AT 842 PM CDT MON APR 6 2015
ISENTROPIC LIFT GENERALLY LACKING ON THE 285K SURFACE OVER
SOUTHWEST AND SOUTHERN NORTH DAKOTA THIS EVENING. MAIN ACTION
FOR SNOW CONTINUES TO BE NORTHWEST INTO THE WEST CENTRAL SECTIONS
OF NORTH DAKOTA. FOR THE REST OF THE EVENING WILL DROP POPS BELOW
15 PERCENT ACROSS THE SOUTHERN THIRD OF THE STATE. WILL THEN
SLOWLY SPREAD CHANCE POPS BACK IN AFTER MIDNIGHT SOUTH. WILL ALSO
TRIM QPF SOUTH AS WELL. THE NORTH LOOKS GOOD.
UPDATE ISSUED AT 618 PM CDT MON APR 6 2015
LATEST HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE TRENDS EARLY
THIS EVENING AND FOLLOWED FOR THE NEXT 6 HOURS OR SO. BAND OF
PRECIPITATION SEEN ON RADAR EXTENDING FROM BISMARCK NORTHWEST TO
BEACH IS MOVING NORTH AND WILL SPREAD ACROSS NORTHWEST ND WHERE
CURRENT HIGH POPS ARE IN GOOD SHAPE. THIS LEAVES THE SOUTHERN
THIRD OF THE STATE WITH LITTLE IN THE WAY OF PRECIPITATION. SO
TRIMMED THE POPS BACK TO SLIGHT CHANCE ACROSS THE SOUTH FOR THE
EVENING. FOCUSED ON THE WEST CENTRAL AND NORTHWEST WHERE BEST
PRECIPITATION WILL BE WIDESPREAD THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM CDT MON APR 6 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE RAIN AND
SNOW CHANCES AND AMOUNTS NOW THROUGH TUESDAY.
CURRENTLY...THE FIRST IN A SERIES OF MID LEVEL S/WV`S APPROACHING
THE NORTHERN PLAINS THIS AFTERNOON. IN RESPONSE PRECIPITATION
DEVELOPMENT UNDERWAY SOUTHWEST WITH BEACH AND DICKINSON NOW
REPORTING SNOW THE PAST HOUR. VERY DRY AIR ACROSS EASTERN NORTH
DAKOTA WILL PREVENT ANYTHING FROM REACHING THE GROUND THIS
AFTERNOON.
PRECIPITATION WILL CONTINUE TO EXPAND NORTH AND EAST AS THE
AFOREMENTIONED WAVE CONTINUES NORTHEAST AND ONCE A STRONGER/MORE
INTENSE WAVE LIFTS INTO THE REGION TONIGHT. IN ADDITION...LOW/MID
LEVEL WINDS WILL BECOME MORE SOUTHEAST TONIGHT VERSUS
EASTERLY...ALLOWING FOR MOISTURE ADVECTION INTO THE REGION HELPING
TO ERODE A VERY DRY BOUNDARY LAYER NOW IN PLACE. SHOULD SEE A
TRANSITION TO ALL SNOW AFTER 00Z AS TEMPERATURES COOL. WILL
CONTINUE THE SPECIAL WEATHER STATEMENT HIGHLIGHTING 3 TO 5 INCHES
OF SNOW FOR PORTIONS OF THE WEST/NORTHWEST/NORTH CENTRAL DURING
THE NEXT 36 HOURS. LESSER AMOUNTS STILL EXPECTED SOUTHWEST AND
SOUTH CENTRAL WHERE A RAIN/SNOW MIX OR ALL RAIN WILL MINIMIZE
ACCUMULATIONS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CDT MON APR 6 2015
THE FOCUS OF THE LONG TERM FORECAST IS THE CHANCE FOR RAIN/SNOW
WEDNESDAY.
LATEST 12 UTC GUIDANCE (WITH THE EXCEPTION OF THE NAM) ARE IN GOOD
AGREEMENT WITH RESPECT TO THE TIMING AND LOCATION OF PRECIPITATION
WEDNESDAY. SNOW IS EXPECTED TO MIX WITH RAIN ACROSS SOUTHWESTERN
NORTH DAKOTA WEDNESDAY MORNING AS A RATHER LARGE AND DEEP LOW
PRESSURE CENTER MOVES ACROSS THE CENTRAL PLAINS. DURING THE DAY
ON WEDNESDAY TEMPERATURES SHOULD BE WARM ENOUGH TO CHANGE SNOW
OVER TO ALL RAIN AND MELT ANY PREVIOUSLY ACCUMULATED SNOW ACROSS
SOUTHERN NORTH DAKOTA. THE MAJORITY OF THE PRECIPITATION AS
DEPICTED IN THE 12 UTC GFS/ECMWF/SREF APPEARS MOST LIKELY TO FALL
ALONG AND SOUTH OF INTERSTATE 94. AS COLDER AIR WRAPS AROUND THE
DEPARTING LOW AND DIURNAL COOLING BEGINS...RAIN MAY TRANSITION
BACK OVER TO SNOW WEDNESDAY NIGHT INTO THURSDAY MORNING.
HOWEVER...ONLY MINOR AMOUNTS ARE ANTICIPATED TO ACCUMULATE AS
GROUND TEMPERATURES SHOULD HOVER RIGHT AROUND FREEZING OVERNIGHT.
THE REST OF THE EXTENDED LOOKS RATHER DRY AND MILD WITH
TEMPERATURES IN THE 60S BY THE WEEKEND. PRECIPITATION MAY RETURN TO
THE REGION BY THE END OF THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1210 AM CDT TUE APR 7 2015
CIGS/VSBYS WILL QUICKLY DETERIORATE TO MVFR/IFR STATUS BY 12Z
TUESDAY AS LIGHT SNOW CONTINUES TO DEVELOP ACROSS THE TERMINALS.
PRECIPITATION WILL BECOME WIDESPREAD FROM 12Z THROUGH 18Z TUESDAY.
EXPECT PRECIPITATION TO WANE FROM SOUTHWEST TO NORTHEAST 18Z TUESDAY
TO 00Z WEDNESDAY. ALTHOUGH VSBYS RETURN TO VFR EARLY TUESDAY
AFTERNOON...SLOWER IMPROVEMENTS CAN BE EXPECTED IN THE
CIGS...LIFTING TO MVFR AND POSSIBLY LOW VFR BETWEEN 00Z AND 06Z
WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...NH
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
954 PM EDT WED APR 8 2015
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL SHOWERS
AND THUNDERSTORMS TO THE REGION THROUGH THURSDAY NIGHT. A COLD
FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT WITH A DRIER
AIRMASS SETTLING INTO THE REGION FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS HAS PUSHED THROUGH THE
AREA THIS EVENING WITH SOME STORMS BEING SEVERE. STORMS GOT GOING
DUE TO A POTENT SHORTWAVE AND A STATIONARY BOUNDARY ACROSS OUR
NORTHERN ZONES. WITH THE SHORTWAVE CURRENTLY EXITING THINK WE WILL
GET A BIT OF A BREAK BEFORE STORMS GET GOING AGAIN AS THE NEXT
UPPER LEVEL DISTURBANCE APPROACHES THE AREA. THERE IS SOME
DISAGREEMENT ON WHETHER WE WILL GET ANOTHER BREAK OR NOT IN THE
AFTERNOON. HRRR AND RAP SHOW REDEVELOPMENT WHILE ARW/ NAM HAVE
REDEVELOPMENT NORTH OF THE AREA. FOR NOW HAVE ONLY MADE MINOR
CHANGES TO FORECAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
PCPN CHANCES ON THURSDAY WILL BE AT LEAST SOMEWHAT DEPENDENT ON
HOW THINGS PLAY OUT TONIGHT AND WHAT KIND OF LINGERING BOUNDARIES/DEBRIS
CLOUDS ARE IN PLACE. AS A RESULT...IT IS TOUGH TO NAIL DOWN TIMING
FOR POPS ON THURSDAY. HOWEVER...IN BROAD SOUTHWESTERLY FLOW AND
WITH SEVERAL EMBEDDED MID LEVEL SHORTWAVES LIFTING THROUGH THE
REGION...WILL BROAD BRUSH TO A DEGREE AND GO WITH LIKELY POPS FOR
MUCH OF THE DAY THURSDAY. ASSUMING WE ARE ABLE TO SUFFICIENTLY
DESTABILIZE THROUGH THE AFTERNOON...SHEAR PROFILES WILL BE
SUPPORTIVE OF SEVERE STORMS AGAIN THURSDAY AFTERNOON INTO
EVENING. THE PRIMARY THREAT WOULD BE DAMAGING WINDS AND LARGE
HAIL ALTHOUGH AN ISOLATED TORNADO WOULD NOT BE OUT OF THE
QUESTION. THE COLD FRONT WILL MOVE THROUGH LATE THURSDAY NIGHT
WITH PCPN TAPERING OFF WEST TO EAST. HIGH PRESSURE AND A DRIER
AIRMASS WILL THEN BUILD INTO THE REGION FOR THE END OF THE WEEK.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
PERIOD STARTS TRANQUIL BUT ACTIVE WEATHER IS FORECAST TO RETURN
EARLY NEXT WEEK. A LARGE AREA OF HIGH PRESSURE WILL BE MOVING ACROSS
THE AREA ON SATURDAY AND SUNDAY. THIS WILL BRING A DRY SPELL THROUGH
THE WEEKEND.
FOR MONDAY THROUGH WEDNESDAY...A WAVY FRONTAL BOUNDARY CONTAINING
ABUNDANT DEEP MOISTURE WILL DEVELOP...RESULTING IN A GOOD CHANCE FOR
SHOWERS AND THUNDERSTORMS EACH DAY. THOUGH IT IS TOO EARLY TO GIVE
AN ACCURATE PREDICTION FOR COVERAGE...DURATION AND INTENSITY OF
THUNDERSTORMS FOR A PARTICULAR LOCATION...THE POTENTIAL EXISTS FOR
SEVERAL ROUNDS OF STRONG TO SEVERE CONVECTION FOR THE FIRST HALF OF
NEXT WEEK.
EXPECT BELOW NORMAL HIGHS IN THE MID 50S TO LOW 60S SATURDAY UNDER
COLD ADVECTION ON A NORTHERLY FLOW AROUND HIGH PRESSURE.
TEMPERATURES WILL SHOW A WARMING TREND STARTING ON SUNDAY AS THE LOW
LEVEL FLOW TURNS SOUTHERLY...WITH HIGHS REACHING AROUND 70 IN MOST
LOCATIONS BY WEDNESDAY.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
SHOWERS AND THUNDERSTORMS HAVE PUSHED IN FROM THE SOUTHWEST AND
WEST THIS EVENING WITH TWO DISTINCT AREAS CURRENTLY ON RADAR. THE
AREA OF STORMS TO THE NORTH ARE IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE ALONG WITH A STATIONARY FRONT THAT IS DRAPED ACROSS
THE AREA. STORMS TO THE SOUTH ARE IN RESPONSE TO THE UPPER LEVEL
DISTURBANCE. THE UPPER LEVEL DISTURBANCE IS FORECASTED TO PUSH
THROUGH THE AREA OVER THE NEXT COUPLE OF HOURS AND CURRENT RADAR
SHOWS A BREAK IN THE RAIN TO THE WEST. THEN EXPECT REDEVELOPMENT
AGAIN TOMORROW MORNING AS ANOTHER UPPER LEVEL DISTURBANCE
APPROACHES FROM THE WEST.
OUTLOOK...THUNDERSTORMS POSSIBLE THURSDAY NIGHT/EARLY FRIDAY
MORNING AS A COLD FRONT MOVES THROUGH THE AREA. GUSTY WEST WINDS
ARE EXPECTED BEHIND THE COLD FRONT ON FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ060>063-
070>073-077>082-088.
KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ089>100.
IN...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...HAINES/JGL
NEAR TERM...HAINES
SHORT TERM...JGL
LONG TERM...CONIGLIO
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
832 PM EDT WED APR 8 2015
.SYNOPSIS...
ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT.
COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT
APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
830 PM UPDATE...
EXPANDED FFA FARTHER N TO ACCOUNT FOR WHERE COMPLEX IS COMING IN
FROM THE W...AND WENT ACROSS THE NRN TIER TO ACCOUNT FOR CONVECTION
ALONG THE 300K ISENTROPIC SFC GRADIENT H8-H85 THERE.
745 PM UPDATE...
UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE
W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC
GRADIENT H8-H85 ACROSS THE NRN TIER.
630 PM UPDATE...
UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL
ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE.
PREV DISCN...
BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING
THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH
AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR
TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS
BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE
LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN
CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS
BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A
HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER
HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES
IN 3 HOURS TO START CREATING LOCAL PROBLEMS.
THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY
MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM
SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE
WEST THURSDAY AFTERNOON.
ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE
PERIOD...AS EXISTING FORECAST LOOKED DECENT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES
ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND
GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS
ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO
EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER
IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY
BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY
AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL
LEVELS BEHIND THE FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND
STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT
BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS
ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA
BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY
TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN
PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR
WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR
THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR
NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO
CONVECTION/HIGHER POPS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SHOWER AND THUNDERSTORM COMPLEXES WILL CONTINUE TO IMPACT THE AREA
THROUGH THE PERIOD. THE FIRST WAS APPROACHING THE OHIO RIVER
ALREADY AND WILL IMPACT THE AREA THROUGH 06Z W TO E. SUBSEQUENT
ONES ARE TOUGHER TO TIME BUT THE NEXT ONE MAY IMPACT THE AREA THU
MORNING EITHER SIDE OF DAWN. RIGHT NOW THE NRN TAF SITES ARE MOST
LIKELY TO BE IMPACTED BY THIS SECOND ONE.
HAVE MOSTLY VFR CONDITIONS IN THE TAFS BUT BRIEF MVFR AND BRIEF IFR
FLIGHT CONDITIONS ARE LIKELY UNDER THE THUNDERSTORMS.
SFC FLOW REGIME IS BASICALLY LIGHT AND VARIABLE OVERNIGHT INTO THU
MORNING AND S TO SW AND A BIT GUSTY MIDDAY THU. STRONG GUSTS ARE
POSSIBLE WITH THUNDERSTORMS FOLLOWED BY VARIABLE FLOW. MODERATE W
TO SW FLW ALOFT EARLY WILL BECOME MODERATE SW OVERNIGHT AND REMAIN
SO ON THU.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING/CATEGORY CHANGES IN SHOWERS/STORMS MAY
VARY. UNCERTAIN ON POST-RAIN FOG FORMATION OVERNIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 04/09/15
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H M M M H H H H H H H
HTS CONSISTENCY H M M L M M H H H H H H
BKW CONSISTENCY H H H M H H H H H H H H
EKN CONSISTENCY H H H M M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 00Z FRIDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WVZ005>011-
013>017-019-020-024>026-031.
OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ066-067-075-
076-083>087.
KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JMV/MZ/SL
NEAR TERM...TRM/MZ
SHORT TERM...JMV
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
747 PM EDT WED APR 8 2015
.SYNOPSIS...
ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT.
COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT
APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
745 PM UPDATE...
UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE
W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC
H8-H85 ACROSS THE NRN TIER.
630 PM UPDATE...
UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL
ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE.
PREV DISCN...
BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING
THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH
AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR
TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS
BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE
LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN
CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS
BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A
HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER
HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES
IN 3 HOURS TO START CREATING LOCAL PROBLEMS.
THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY
MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM
SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE
WEST THURSDAY AFTERNOON.
ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE
PERIOD...AS EXISTING FORECAST LOOKED DECENT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES
ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND
GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS
ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO
EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER
IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY
BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY
AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL
LEVELS BEHIND THE FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND
STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT
BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS
ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA
BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY
TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN
PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR
WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR
THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR
NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO
CONVECTION/HIGHER POPS.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
SHOWER AND THUNDERSTORM COMPLEXES WILL CONTINUE TO IMPACT THE AREA
THROUGH THE PERIOD. THE FIRST WAS APPROACHING THE OHIO RIVER
ALREADY AND WILL IMPACT THE AREA THROUGH 06Z W TO E. SUBSEQUENT
ONES ARE TOUGHER TO TIME BUT THE NEXT ONE MAY IMPACT THE AREA THU
MORNING EITHER SIDE OF DAWN. RIGHT NOW THE NRN TAF SITES ARE MOST
LIKELY TO BE IMPACTED BY THIS SECOND ONE.
HAVE MOSTLY VFR CONDITIONS IN THE TAFS BUT BRIEF MVFR AND BRIEF IFR
FLIGHT CONDITIONS ARE LIKELY UNDER THE THUNDERSTORMS.
SFC FLOW REGIME IS BASICALLY LIGHT AND VARIABLE OVERNIGHT INTO THU
MORNING AND S TO SW AND A BIT GUSTY MIDDAY THU. STRONG GUSTS ARE
POSSIBLE WITH THUNDERSTORMS FOLLOWED BY VARIABLE FLOW. MODERATE W
TO SW FLW ALOFT EARLY WILL BECOME MODERATE SW OVERNIGHT AND REMAIN
SO ON THU.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING/CATEGORY CHANGES IN SHOWERS/STORMS MAY
VARY. UNCERTAIN ON POST-RAIN FOG FORMATION OVERNIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 04/09/15
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H M M M H H H H H H H
HTS CONSISTENCY H M M L M M H H H H H H
BKW CONSISTENCY H H H M H H H H H H H H
EKN CONSISTENCY H H H M M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 00Z FRIDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WVZ005-006-013.
OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ087.
KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JMV/MZ/SL
NEAR TERM...TRM/MZ
SHORT TERM...JMV
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
243 PM EDT TUE APR 7 2015
.SYNOPSIS...
A WARM AND MOIST SOUTH TO SOUTHWEST WIND FLOW WILL BRING ROUNDS OF
SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK. COLD FRONT CROSSES AT
THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LOTS OF CONVECTION TO OUR WEST...WITH ONLY LINGERING MASS ACROSS THE
NORTHERN MOUNTAINS. TO OUR WEST...HAVE AREA BETWEEN KHTS AND
KLEX...MOVING SOUTHEAST ALONG A WEAK SURFACE BOUNDARY. THIS
CONVECTION WILL MOVE ACROSS THE SOUTHERN CWA LATE THIS AFTERNOON
INTO THIS EVENING. FARTHER WEST...IN SOUTHERN INDIANA HAVE
ANOTHER COMPLEX MOVING EAST. NAM/HRRR AND SOME WRF RUNS SHOW A MCV
WITH THIS MOVING ACROSS SOUTHERN CWA TONIGHT. RAP IS A BIT FARTHER
NORTH. AS A SURFACE LOW MOVES THROUGH MISSOURI TONIGHT...EXPECT
THE SURFACE BOUNDARY TO SLOWLY MOVE NORTH CROSSING SOUTHERN CWA
DURING THE EARLY MORNING. WITH A FAIRLY WET GROUND IN PLACE ACROSS
SOUTHERN CWA AFTER HEAVY RAIN LATE LAST WEEK...AND ANTICIPATING
ANOTHER COUPLE ROUNDS OF AT LEAST MODERATE RAIN TONIGHT...WITH GO
WITH A FLASH FLOOD WATCH ALONG AND SOUTH OF I-64. BEST CASE
SCENARIO IS THE HEAVIEST RAIN STICKS CLOSER TO THE INFLOW AND
REMAINS MAINLY SOUTH OF CWA...WITH JUST A PERIOD OF LIGHT TO
MODERATE RAIN WITH THE REMNANTS OF THE MCV. WORST CASE WOULD BE IF
EACH WAVE CROSSES THROUGH THE SAME AREA OF SOUTHERN CWA.
EXPECT A BREAK IN PRECIP...ALTHOUGH CANNOT RULE OUT AN ISOLATED
SHOWER...THROUGH MUCH OF WEDNESDAY MORNING. HAVE ANOTHER AREA OF
LIKELY POPS MOVING FROM WEST TO EAST ACROSS CWA WEDNESDAY AFTERNOON
AS A SHORTWAVE TROUGH MOVES OVER.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MODELS ARE CLOSER TO AGREEMENT...ON LIFTING A SURFACE BOUNDARY AND
UPPER IMPULSE NORTH ACROSS THE AREA WEDNESDAY NIGHT...FOLLOWED BY A
COLD FRONT LATE THURSDAY NIGHT AND FRIDAY. WITH MOIST AND UNSTABLE
AIR IN PLACE...THESE TWO FEATURES WILL BE THE FOCUS FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY THE COLD FRONT. IN BETWEEN...IN THE WARM
SECTOR ON THURSDAY...THERE COULD BE A SHOWER OR THUNDERSTORM
ESPECIALLY IN THE AFTERNOON WITH HEATING. TIMING OF COLD FRONT HAS
IT REACHING THE OHIO RIVER AROUND DAWN FRIDAY...THEN PROGRESSING
ACROSS THE REMAINDER OF AREA DURING FRIDAY. WITH GOOD UPPER SUPPORT
AND PLENTY OF WARM AND MOIST UNSTABLE AIR...A BAND OF ORGANIZED
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ALONG AND AHEAD OF THE
COLD FRONT. WILL HAVE TO WATCH FOR WATER PROBLEMS AND STRONG STORMS
IN THIS TIME FRAME. UPON COLD FRONT PASSAGE FRIDAY...EXPECT
IMPROVEMENT FROM THE WEST. TEMPERATURE RANGES THIS PERIOD WILL BE
LOWERED SOMEWHAT BY THE CLOUDS AND SHOWERS...BUT THURSDAY MAY BE
WARMER THAN FORECAST IF SUNSHINE MAKES A DETERMINED APPEARANCE IN
THE WARM SECTOR. IN ANY CASE...NO EXTREMES IN TEMPERATURE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE QUICKER WITH THE COLD FRONTAL PASSAGE ON FRIDAY LEAVING
FRIDAY NIGHT MOSTLY DRY. THE OUTLIER IS THE ECMWF WHICH LAGS ABOUT 6
HOURS IN ITS QPF FIELD. WENT WITH THE CONSENSUS OF MODELS WITH A
FASTER SOLUTIONS.
HIGH PRESSURE BRINGS WIDESPREAD DRY WEATHER FRIDAY NIGHT THROUGH THE
WEEKEND. ANOTHER UPPER WAVE APPROACHES MONDAY BRINGING BACK CHANCES
FOR PCPN ACROSS THE AREA.
TEMPERATURES EXPECTED TO BE WARM REACHING THE UPPER 70S THROUGH THE
PERIOD...EXCEPT FOR A SLIGHT COOL DOWN BEHIND THE COLD FRONT
SATURDAY...GENERALLY IN THE MID TO UPPER 60S. WENT CLOSE TO WPC
GUIDANCE WITH FEW TWEAKS THROUGH THE PERIOD.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
MESSY SITUATION WITH SHOWERS AND SOME THUNDERSTORMS DRIFTING
MAINLY EASTWARD ACROSS CWA. SEVERAL COMPLEXES TO OUR WEST WILL
TRY TO MOVE EAST...BUT MAY ALSO BE SHUNTED SOUTH ALONG A
BOUNDARY...CREATING A GOOD DEAL OF UNCERTAINTY. HAVE SOME MVFR
AND VCTS TRYING TO TIME THESE...BUT COULD BE OFF A BIT AND WOULD
NOT BE SURPRISED TO GET PERIODS OF IFR IN HEAVIER RAIN. BEST
CHANCE OF SHOWERS/STORMS THIS EVENING AND TONIGHT WILL BE ACROSS
THE SOUTH. ALSO PUT IN SOME MVFR FOG BEHIND TONIGHTS BATCH OF
SHOWERS...AGAIN MAINLY ACROSS THE SOUTH.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS COULD VARY.
FOG COULD FORM IN AREAS RECEIVING RAINFALL TUESDAY NIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M H H
HTS CONSISTENCY M H M H H H H H M M M M
BKW CONSISTENCY H H H H H M H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M M M M M M M M M H M M
CKB CONSISTENCY H H H H H M H M M M M M
AFTER 18Z WEDNESDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR WVZ005-006-
013>015-024>026-033>036.
OH...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR OHZ087.
KY...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR VAZ003-004.
&&
$$
SYNOPSIS...ARJ/JMV/MZ
NEAR TERM...MZ
SHORT TERM...JMV
LONG TERM...ARJ
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
233 PM EDT TUE APR 7 2015
.SYNOPSIS...
A WARM AND MOIST SOUTH TO SOUTHWEST WIND FLOW WILL BRING ROUNDS OF
SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK. COLD FRONT CROSSES AT
THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LOTS OF CONVECTION TO OUR WEST...WITH ONLY LINGERING MASS ACROSS THE
NORTHERN MOUNTAINS. TO OUR WEST...HAVE AREA BETWEEN KHTS AND
KLEX...MOVING SOUTHEAST ALONG A WEAK SURFACE BOUNDARY. THIS
CONVECTION WILL MOVE ACROSS THE SOUTHERN CWA LATE THIS AFTERNOON
INTO THIS EVENING. FARTHER WEST...IN SOUTHERN INDIANA HAVE
ANOTHER COMPLEX MOVING EAST. NAM/HRRR AND SOME WRF RUNS SHOW A MCV
WITH THIS MOVING ACROSS SOUTHERN CWA TONIGHT. RAP IS A BIT FARTHER
NORTH. AS A SURFACE LOW MOVES THROUGH MISSOURI TONIGHT...EXPECT
THE SURFACE BOUNDARY TO SLOWLY MOVE NORTH CROSSING SOUTHERN CWA
DURING THE EARLY MORNING. WITH A FAIRLY WET GROUND IN PLACE ACROSS
SOUTHERN CWA AFTER HEAVY RAIN LATE LAST WEEK...AND ANTICIPATING
ANOTHER COUPLE ROUNDS OF AT LEAST MODERATE RAIN TONIGHT...WITH GO
WITH A FLASH FLOOD WATCH ALONG AND SOUTH OF I-64. BEST CASE
SCENARIO IS THE HEAVIEST RAIN STICKS CLOSER TO THE INFLOW AND
REMAINS MAINLY SOUTH OF CWA...WITH JUST A PERIOD OF LIGHT TO
MODERATE RAIN WITH THE REMNANTS OF THE MCV. WORST CASE WOULD BE IF
EACH WAVE CROSSES THROUGH THE SAME AREA OF SOUTHERN CWA.
EXPECT A BREAK IN PRECIP...ALTHOUGH CANNOT RULE OUT AN ISOLATED
SHOWER...THROUGH MUCH OF WEDNESDAY MORNING. HAVE ANOTHER AREA OF
LIKELY POPS MOVING FROM WEST TO EAST ACROSS CWA WEDNESDAY AFTERNOON
AS A SHORTWAVE TROUGH MOVES OVER.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STILL TRYING TO HONE IN ON WHICH PERIODS ARE MOST ACTIVE IN THIS
UNSETTLED WEEK. THE FIRST IMPULSE WITH MOST AGREEMENT IS WEDNESDAY
MORNING ACROSS SE OH AND N WV WITH A MORE ROBUST ONE SLATED FOR
WEDNESDAY AFTERNOON ACROSS MUCH OF THE AREA. A BREAK WEDNESDAY
EVENING BEFORE CONVECTION GETS GOING ONCE AGAIN...THIS TIME ALONG A
NEW WARM FRONTAL BOUNDARY WHICH WILL SLIDE OFF TO N THURSDAY
MORNING. ATTENTION THEN TRIES TO FOCUS MORE ALONG DEVELOPING LOW
PRESSURE AND AMPLIFYING UPPER TROF ACROSS THE MIDWEST WHICH MAY
ALLOW FOR A BRIEF RESPITE FROM THE MORE WIDESPREAD CONVECTION...SAVE
FOR PERHAPS SE OH. THUS THURSDAY MAY BE OUR WARMEST THIS WEEK. TREND
IS FOR A MORE AMPLIFIED SYNOPTIC PATTERN WITH THE UPPER TROF...THUS
A FASTER FROPA...NOW SLATED FOR FRIDAY WITH ANOTHER ROUND OF
CONVECTION. THINGS DRY OUT FRIDAY NIGHT WITH THE WEEKEND SHAPING UP
TO BE RATHER NICE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE QUICKER WITH THE COLD FRONTAL PASSAGE ON FRIDAY LEAVING
FRIDAY NIGHT MOSTLY DRY. THE OUTLIER IS THE ECMWF WHICH LAGS ABOUT 6
HOURS IN ITS QPF FIELD. WENT WITH THE CONSENSUS OF MODELS WITH A
FASTER SOLUTIONS.
HIGH PRESSURE BRINGS WIDESPREAD DRY WEATHER FRIDAY NIGHT THROUGH THE
WEEKEND. ANOTHER UPPER WAVE APPROACHES MONDAY BRINGING BACK CHANCES
FOR PCPN ACROSS THE AREA.
TEMPERATURES EXPECTED TO BE WARM REACHING THE UPPER 70S THROUGH THE
PERIOD...EXCEPT FOR A SLIGHT COOL DOWN BEHIND THE COLD FRONT
SATURDAY...GENERALLY IN THE MID TO UPPER 60S. WENT CLOSE TO WPC
GUIDANCE WITH FEW TWEAKS THROUGH THE PERIOD.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
MESSY SITUATION WITH SHOWERS AND SOME THUNDERSTORMS DRIFTING
MAINLY EASTWARD ACROSS CWA. SEVERAL COMPLEXES TO OUR WEST WILL
TRY TO MOVE EAST...BUT MAY ALSO BE SHUNTED SOUTH ALONG A
BOUNDARY...CREATING A GOOD DEAL OF UNCERTAINTY. HAVE SOME MVFR
AND VCTS TRYING TO TIME THESE...BUT COULD BE OFF A BIT AND WOULD
NOT BE SURPRISED TO GET PERIODS OF IFR IN HEAVIER RAIN. BEST
CHANCE OF SHOWERS/STORMS THIS EVENING AND TONIGHT WILL BE ACROSS
THE SOUTH. ALSO PUT IN SOME MVFR FOG BEHIND TONIGHTS BATCH OF
SHOWERS...AGAIN MAINLY ACROSS THE SOUTH.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS COULD VARY.
FOG COULD FORM IN AREAS RECEIVING RAINFALL TUESDAY NIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M H H
HTS CONSISTENCY M H M H H H H H M M M M
BKW CONSISTENCY H H H H H M H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M M M M M M M M M H M M
CKB CONSISTENCY H H H H H M H M M M M M
AFTER 18Z WEDNESDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR WVZ005-006-
013>015-024>026-033>036.
OH...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR OHZ087.
KY...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR VAZ003-004.
&&
$$
SYNOPSIS...ARJ/MZ/30
NEAR TERM...MZ
SHORT TERM...30
LONG TERM...ARJ
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1036 AM EDT TUE APR 7 2015
.SYNOPSIS...
A WEST-TO-EAST ORIENTED FRONTAL BOUNDARY WILL MEANDER NEAR THE
AREA THROUGH THURSDAY NIGHT AND WILL LEAD TO OCCASIONAL CHANCES
FOR SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE THROUGH LATE
THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE WILL THEN WORK INTO THE
REGION FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CONFIDENCE FORECAST TODAY INTO THIS EVENING IN LOW AMPLITUDE/WEAKLY
FORCED REGIME. 07.12Z KILN RAOB SAMPLED ELEVATED INSTBY /500 J/KG/
ATOP A STABLE BOUNDARY LAYER. WHILE BULK SHEAR VALUES ARE
IMPRESSIVE - EFFECTIVE SHEAR /WHAT UPDRAFTS ARE TRULY FEELING/ IS
QUITE WEAK THUS SHOWERS/STORMS HAVE BEEN WEAK/MODERATE IN
INTENSITY. 25-35KTS OF WSWLY FLOW ABOVE THE BOUNDARY LAYER
CONTINUES MOISTURE TRANSPORT/ISENTROPIC ASCENT THIS MORNING AND IS
PROGGED BY RAP/HRRR TO SLOWLY MIX OUT/WEAKEN AS THE FLOW BACKS
SOMEWHAT. STRONG E-W FRONTAL ZONE WILL CONTINUE TO BE REINFORCED
ACRS CNTL OH/IND WITH FRIGID LAKE ERIE WATERS AND NORTHEAST WINDS
THRU NRN OH REALLY ENHANCING BAROCLINICITY TO THIS FRONT. BY MID
AFTN EXPECT TEMPS TO RANGE ONLY IN THE MID 40S IN FAR NORTHERN
FORECAST AREAS TO 60S AND POSSIBLY 70 IN THE FAR. DEGREE OF
WARMING IS VERY MUCH IN QUESTION ALL AREAS...AS AMPLE CLOUDS ARE
IN PLACE /MANY CIGS AT OR BELOW 1KFT/ WHICH MAKES WARMING
DIFFICULT. IN ADDITION ANVIL BLOWOFF FROM KY/MO CONVECTION WILL
ADD ADDITIONAL MID/HIGH LEVEL MOISTURE THROUGH THE DAY. SO HAVE
BROUGHT TEMPS BACK A LITTLE BIT FROM PVS FORECAST.
WATCHING TWO CLUSTERS OF STORMS RIGHT NOW...ONE NEAR LOUISVILLE
WHICH IS WEAKENING AND A MORE POTENT/ORGANIZED MCS NEAR ST. LOUIS.
EXPECT BOTH CONVECTIVE SYSTEMS TO DIVE SOUTHEAST INTO BETTER
INSTBY/MOISTURE TRANSPORT...AND REMAIN MOSTLY SOUTH OF THE AREA.
THUS...EXPECT A GENERAL DECREASE IN RAIN CHANCES THROUGH THE DAY
THOUGH SHRA/TSRA AREN/T EXPECTED TO TOTALLY DISSIPATE. ISLD-SCT
ACTIVITY TO LIKELY CONTINUE IN THE BROAD MOIST/WARM ADVECTION.
AGREE WITH 13Z SPC UPDATE TO REMOVE MARGINAL SVR THREATS FROM OUR
SOUTH...THOUGH PROXIMITY TO BETTER INSTBY IS IN OUR SOUTHWEST SO
CAN/T RULE OUT A STRONGER STORM OR TWO IN OUR FAR SOUTHWEST LATER
THIS AFTN DEPENDING ON HOW MO/IL CONVECTION EVOLVES. THIS IN LINE
WITH RATHER STABLE HRRR RUNS OVER THE PAST FEW HOURS DEPICTING
CONVECTIVE EVOLUTION FROM MO/IL THROUGH KY WITH MORE ISOLD/SCT
ACTIVITY FURTHER NORTH INTO OHIO AND NEAR THE STATIONARY FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
DISTURBANCE WILL MOVE TO THE EAST THIS EVENING. THIS WILL ALLOW
FOR A DECREASE IN PRECIPITATION CHANCES. BEST CHANCE FOR
PRECIPITATION TONIGHT WILL BE ACROSS NORTHERN PORTIONS OF THE FA
CLOSER TO THE FRONTAL BOUNDARY. AGAIN THERE WILL BE A SHARP
GRADIENT IN TEMPERATURES NORTH AND SOUTH OF THE BOUNDARY. NORTHERN
PORTIONS OF THE FA WILL DROP DOWN INTO THE 40S WHILE SOUTHERN
PORTIONS OF THE FA WILL BE IN THE 60S.
FRONTAL BOUNDARY WILL PUSH JUST NORTH OF THE FA ON WEDNESDAY.
SOUTHERLY FLOW WILL ALLOW FOR TEMPERATURES ACROSS THE FA TO RISE
INTO THE 60S AND 70S. ANOTHER DISTURBANCE WILL WORK THROUGH THE
REGION BRINGING ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY TO THE
AREA.
A COUPLE MORE ROUNDS OF THUNDERSTORMS ARE EXPECTED TO MOVE THROUGH
WEDNESDAY NIGHT INTO THURSDAY MORNING AND THEN AGAIN THURSDAY
AFTERNOON. SOUTHERLY FLOW PICKS UP FOR THURSDAY WITH GUSTY WINDS
AROUND 30 TO 35 MPH. THIS WILL ALLOW FOR TEMPERATURES TO BE IN THE
70S ACROSS MOST OF THE AREA AND A FEW LOCATIONS NEAR 80 ACROSS FAR
SE PORTIONS OF THE FA.
A COLD FRONT WILL MOVE THROUGH LATE THURSDAY NIGHT INTO FRIDAY
MORNING ALLOWING FOR COOLER TEMPERATURES TO MOVE INTO THE AREA.
PRECIPITATION WILL TAPER OFF DURING THE MORNING HOURS ON FRIDAY
AFTER THE FRONTAL PASSAGE. GUSTY WINDS ARE AGAIN EXPECTED DURING
THE DAY ON FRIDAY. WITH THE DECREASE IN CLOUD COVER FRIDAY NIGHT
AND THE COOL AIRMASS IN PLACE...EXPECT TEMPERATURES TO DROP DOWN
INTO THE 30S AND 40S FRIDAY NIGHT.
WITH SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW
DAYS THERE IS THE POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES.
ALSO...ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED AT THIS
TIME CANNOT RULE OUT ISOLATED STRONG TO SEVERE STORMS THE NEXT FEW
DAYS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO THE AREA. COOLER
WEATHER WILL RETURN WITH HIGHS RANGING FROM THE MID 50S NORTH THE
LOWER 60S SOUTH ON SATURDAY.
FOR SUNDAY INTO MONDAY...HIGH PRESSURE IS FORECAST TO MOVE EAST. A
WARM FRONT WILL LIFT TOWARD THE OHIO VALLEY BY SUNDAY NIGHT.
THEREAFTER...A COLD FRONT WILL APPROACH THE REGION FROM THE WEST
LATE MONDAY. WITH RETURN...MOIST FLOW...THE THREAT FOR
SHOWERS/STORMS WILL ONCE AGAIN INCREASE. TEMPERATURES WILL WARM TO
ABOVE NORMAL READINGS ONCE AGAIN.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
INITIAL ROUND OF CONVECTION WILL MOVE EAST OF THE TERMINALS EARLY
IN THE TAF PERIOD. EXPECT IFR CEILINGS TO SPREAD IN BEHIND THIS
ACTIVITY EXCEPT IN THE COLUMBUS AREA WHERE IT MAY REMAIN MVFR.
QUITE A BIT OF UNCERTAINTY WHERE AND WHEN ADDITIONAL SHOWERS AND
THUNDERSTORMS WILL OCCUR THROUGH THE DAY. HAVE USED VCTS TO
INDICATE TIMES WHEN CHANCE APPEARS HIGHER AND WILL AMEND TO
INCLUDE A TEMPO GROUP AS WARRANTED. CEILINGS WILL LIFT SOMEWHAT
THROUGH THE DAY ALTHOUGH IT DOES APPEAR THAT CEILINGS WILL REMAIN
MVFR THROUGHOUT. THERE COULD BE SOME BREAKS IN THE CLOUDS AROUND
00Z BUT THESE ARE EXPECTED TO FILL IN OVERNIGHT. CEILINGS WILL
LOWER ONCE AGAIN WITH BOUNDARY LAYER COOLING AND PREVAILING IFR
CEILINGS LOOK POSSIBLE BY LATE IN THE PERIOD. A FRONT WILL SAG
SOUTH TODAY BEFORE STALLING AND LIFTING BACK NORTH TONIGHT. SOME
UNCERTAINTY HOW FAR SOUTH THIS GETS BUT IT SEEMS LIKELY THAT KDAY
TO KCMH/KLCK TERMINALS WILL HAVE A WIND SHIFT. BUT WIND SPEEDS
WILL BE LESS THAN 10 KT.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE LIKELY WEDNESDAY
MORNING. THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...BINAU
SHORT TERM...NOVAK
LONG TERM...HICKMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS TULSA OK
322 PM CDT TUE APR 7 2015
.DISCUSSION...
A WEAK FRONTAL BOUNDARY EXTENDS FROM WEST OF KANSAS CITY INTO NW
OKLAHOMA THIS AFTERNOON WITH A VERY UNSTABLE BUT STRONGLY CAPPED
AIRMASS RESIDING OVER EASTERN OK AND NORTHWEST AR. TEMPS ALONG AND
SE OF THE FRONT HAVE WARMED INTO THE MID 80S TO NEAR 90...AND ALSO
A SUBTLE OUTFLOW BOUNDARY FROM EARLIER STORMS PUSHING THROUGH SW
MISSOURI AT THIS TIME. NO SIGNIFICANT UPPER AIR FORCING AT THIS
POINT...BUT ISOLATED STORMS STILL MAY DEVELOP NEAR THE SFC FRONT
AND OUTFLOW BOUNDARY LATER THIS AFTERNOON OR EARLY THIS EVENING
AS HRRR AND TO A LESSER EXTENT OUR LOCALLY RUN 5KM WRF CONTINUE TO
INDICATE. GIVEN THE AMOUNT OF AVAILABLE CAPE AND AT LEAST MODERATE
SHEAR ANY STORMS COULD BECOME SEVERE SHOULD UPDRAFTS BE
SUSTAINED... LARGE HAIL AND WINDS THE MAIN THREATS. CAP WILL
REMAIN WITH US FOR THE MOST PART THROUGH TONIGHT WITH ONLY A
LIMITED CHANCE OF STORMS NEAR KANSAS AND MISSOURI BORDERS.
UNSTABLE AND CAPPED ENVIRONMENT REMAINS WITH US WEDNESDAY...
HOWEVER WITH UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST MOVING
INTO THE CENTRAL ROCKIES DURING THE DAY...MID LEVEL HEIGHT FALLS
AND A POTENTIAL LEAD SHORT WAVE/ JET STREAK SHOULD HELP ERODE THE
CAP ENOUGH FOR SOME STORMS TO DEVELOP ALONG THE DRY LINE FROM
CENTRAL KS INTO NORTHERN OK. MOST LIKELY TIME WOULD BE 21-00Z
HOWEVER EARLIER RUNS OF THE NAM HAVE SHOWN SOME EARLIER
DEVELOPMENT THAN THAT. WIND PROFILES SUGGEST THAT ONCE A STORM
DEVELOPS IT WILL QUICKLY BECOME SUPERCELLULAR AND POSE A THREAT
FOR VERY LARGE GAIL AND DAMAGING WINDS...AND SOME DEGREE OF
TORNADO POTENTIAL. OVERALL STORM COVERAGE IS EXPECTED TO REMAIN
FAIRLY LIMITED THROUGH WED NIGHT DUE TO PERSISTENT CAP ISSUES.
MAIN UPPER SYSTEM CONTINUES TO PROGRESS EAST THURSDAY WITH A COLD
FRONT OVERTAKING THE DRY LINE AND LIKELY PUSHING THROUGH PARTS OF
NE OKLAHOMA BY EARLY AFTERNOON. CONTINUED MOIST AND VERY UNSTABLE
AHEAD OF THE FRONT WITH MORE WIDESPREAD THUNDERSTORMS LIKELY THU
AFTERNOON AND EVENING MAINLY OVER SOUTHEAST OK AND NORTHWEST AR.
SHEAR PROFILES SUGGEST A MORE LINEAR STORM MODE AT THIS TIME.
STORMS WILL END THU EVENING WITH A COOLER AND STABLE AIRMASS
SETTLING OVER THE AREA FRIDAY.
ANOTHER UPPER LEVEL SYSTEM WILL MOVE IN FROM THE WEST BY THIS
WEEKEND AND WITH THE PRESENCE OF A SFC BOUNDARY IN THE AREA...
THUNDERSTORM CHANCES WILL RETURN BY SATURDAY AND CONTINUE INTO
EARLY NEXT WEEK. GENERAL CONSENSUS IS THIS UPPER LOW WILL
ULTIMATELY TACK A MUCH MORE SOUTHERLY TRACK...ANY SEVERE WEATHER
THREATS DURING THIS TIME REMAIN EXTREMELY UNCERTAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 84 68 78 / 10 40 30 40
FSM 65 83 66 77 / 10 20 30 70
MLC 68 80 68 77 / 10 20 20 40
BVO 66 84 65 77 / 20 50 30 30
FYV 64 79 64 73 / 20 20 30 60
BYV 64 80 64 73 / 20 20 30 60
MKO 66 81 66 77 / 10 20 30 50
MIO 66 81 66 75 / 20 30 40 40
F10 67 83 67 78 / 10 20 20 40
HHW 65 79 66 77 / 10 10 30 60
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...06
LONG TERM....14
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1153 PM CDT MON APR 6 2015
.AVIATION...07/06Z TAF ISSUANCE...
CEILINGS AND VISIBILITY REMAIN A CHALLENGE FOR SITES ACROSS SWRN
AND POSSIBLY CENTRAL OK THIS MORNING. LATEST SHORT RANGE GUIDANCE
SUGGEST VFR CONDITIONS WILL PREVAIL AND GIVEN CURRENT
CONDITIONS... THIS SOLUTION SEEMS LIKELY. HOWEVER... THERE MAY BE
A CHANCE OF LIGHT FOG... BUT MORE LIKELY LOW STRATUS CLOUDS ACROSS
A NARROW CORRIDOR OF WRN OK WHERE WINDS RELAX SLIGHTLY AND
TEMP/DEW POINT SPREADS LESSEN NEAR DAY BREAK. OVERALL... EXPECT
VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD AT THIS TIME... BUT
FEEL COMPELLED TO PUT IN A TEMPO FOR LIGHT 4SM BR AND MVFR CIGS AT
KCSM/KHBR AROUND SUNRISE. SOUTH WINDS WILL REMAIN BREEZY
OVERNIGHT... INCREASING TOMORROW LATE MORNING/AFTERNOON AS THE
PRESSURE GRADIENT INCREASES AND A DRY LINE PUSHES EASTWARD INTO
WRN OK/WRN N TX. GUSTS ACROSS WRN INTO CENTRAL OK COULD APPROACH
20 TO 25 KTS THROUGH THE AFTN.
JTK
&&
.PREV DISCUSSION... /ISSUED 714 PM CDT MON APR 6 2015/
UPDATE...
UPDATE TEMPS... WEATHER...
DISCUSSION...
ADJUSTED ISOLATED THUNDER TO A MORE CONFINED AREA OF CENTRAL TO
SWRN OK TO WRN N TX IN ACCORDANCE WITH THE SIGNIFICANT CLOUD COVER
AND SPORADIC CUMULUS THAT HAS DEVELOPED ALONG THE DRY LINE SWRN
OK. THE CHANCE FOR A FEW ISOLATED STORMS CANNOT BE RULED OUT
THROUGH SUNSET... BUT THE CHANCE REMAINS VERY LOW.
ADJUSTED TEMPS... BRINING THEM BACK IN LINE WITH OBS TREND AS
CURRENT FORECAST WAS RUNNING A TAD COOLER ACROSS WRN OK...
CONSIDERING THERE IS STILL UPPER 80S AND LOWER 90S IN THE TX
PANHANDLE.
JTK
PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 6 2015/
DISCUSSION...
CONVECTION...
THE HRRR AND RAP HAVE SHOWN A RELATIVELY CONSISTENT SIGNAL OF
ISOLATED STORM/S/ DEVELOPING IN THE SOUTHWEST LATE THIS AFTERNOON.
MESOANALYSIS SHOW CONVECTIVE INHIBITION DECEASING ACROSS NORTHWEST
TEXAS. IT IS NOT A SURE THING THAT ANY STORM WILL DEVELOP AND
COVERAGE WILL BE LIMITED IF STORMS DO DEVELOP. BUT THERMODYNAMIC
PROFILE SHOWS QUITE AN UNSTABLE ATMOSPHERE... SO SEVERE WEATHER
WOULD BE LIKELY IF A STORM DOES INDEED DEVELOP. WILL KEEP POPS
BELOW 20 BUT ADD ISOLATED THUNDER IN THE WEATHER GRIDS IN TO COVER
THE POTENTIAL DEVELOPMENT. MUCH THE SAME SCENARIO IS EXPECTED
TOMORROW WITH AN UNSTABLE BUT GENERALLY CAPPED ATMOSPHERE WITHOUT
SIGNIFICANT FORCING... BUT CONVECTIVE INHIBITION DECREASES ENOUGH
THAT ISOLATED STORMS ARE POSSIBLE AGAIN IN THE LATE AFTERNOON AND
EARLY EVENING.
WEDNESDAY STILL LOOKS TO HAVE A MORE SIGNIFICANT SEVERE WEATHER
POTENTIAL AS THE TROUGH THAT IS CURRENTLY LOCATED OFF THE PACIFIC
COAST MOVES TOWARD THE HIGH PLAINS. WE EXPECT STORMS TO DEVELOP
WEDNESDAY AFTERNOON OR EVENING NEAR THE DRYLINE AND SPREAD EAST
WITH A DECENT CHANCE OF SEVERE WEATHER. THE STORM CHANCES WILL
LINGER INTO THURSDAY IN THE SOUTHEAST UNTIL THE SURFACE FRONT
MOVES THROUGH.
AFTER A BRIEF RESPITE FRIDAY...ANOTHER UPPER TROUGH APPROACHES
THIS WEEKEND INCREASING STORM CHANCES AGAIN THIS WEEKEND. EVEN AS
THE FIRST TROUGH MOVES BY THE PLAINS... THE MEAN TROUGH WILL
PERSIST IN THE WEST ALLOWING CONTINUED STORM CHANCES THROUGH
MONDAY.
FIRE WEATHER...
GUSTY POST-DRYLINE WINDS HAVE SPREAD INTO NORTHWESTERN OKLAHOMA
ALONG WITH TEMPERATURES IN THE LOWER 90S AND HUMIDITY IN THE
SINGLE DIGITS AND TEENS.... SO THE CURRENT RED FLAG WARNING LOOKS
GOOD INTO THE EARLY EVENING. ALTHOUGH WE WILL HAVE THE HEAT AND
LOW HUMIDITY AGAIN TOMORROW... WINDS ARE EXPECTED TO BE LIGHTER.
WINDS LOOK HIGHER AGAIN ON WEDNESDAY SO THE FIRE WEATHER WATCH IS
STILL VALID.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 84 66 82 / 10 20 20 30
HOBART OK 60 87 64 86 / 10 10 10 20
WICHITA FALLS TX 66 87 66 88 / 10 20 10 30
GAGE OK 53 88 53 85 / 10 0 10 10
PONCA CITY OK 63 87 64 85 / 10 20 20 40
DURANT OK 68 80 68 81 / 10 10 10 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR OKZ004>006-009>011-014>016-021-022-033>037.
TX...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR TXZ083>085-087-088.
&&
$$
99/99/01
AREA FORECAST DISCUSSION
NWS PORTLAND
224 PM PDT TUE APR 7 2015
.SYNOPSIS...A LOW PRES MOVING INTO NORTHERN CALIFORNIA WILL TRACK
EAST INTO NORTHERN NV LATE TONIGHT AND WEDNESDAY. ANOTHER WEAK TROUGH
OF LOW PRES ALOFT WILL MOVE S OVER EASTERN WA AND OREGON WED AS A
SURFACE RIDGE OF HIGH PRES STRENGTHENS ALONG THE COAST. THE HIGH WILL
MOVE INLAND WED NIGHT AND THU. THE NEXT PACIFIC FRONTAL SYSTEM IS
EXPECTED TO MOVE DOWN FROM THE GULF OF AK AND PUSH INLAND FRI AND FRI
NIGHT FOR MORE LOWLAND RAIN AND CASCADE SNOW FOR THE WEEKEND.
&&
.SHORT TERM...A VERTICALLY STACKED UPPER LOW JUST MAKING LANDFALL ON
THE NORTH CALIFORNIA COAST THIS AFTERNOON AND CONTINUES TO MOVE
SLOWLY EAST-SOUTHEAST INTO NORTHERN CALIFORNIA. THE FRONT FROM LAST
NIGHT CONTINUES TO DISSIPATE OVER THE NORTHERN ZONES. THE NEXT FRONT
IS ROTATING AROUND THE SE QUADRANT OF THE LOW IN NRN CALIFORNIA. THE
FRONT LOOKS LIKE IT WILL SWING INTO THE CWA AS A DEFORMATION ZONE
AND STALL SOMEWHERE NEAR OVER THE SE ZONES. THE CENTRAL OREGON
CASCADES WILL PROBABLY RECEIVE THE MOST PCPN. THE GFS AND ECMWF
HOLD THE HIGHER PCPN AMOUNTS OVER THE CASCADES OF LINN AND LANE
COUNTIES. HOWEVER THIS MORNING RUNS OF THE HRRR AND NAM HAVE
EXPANDED THE HIGH PCPN AMOUNTS CLOSER TO MT. HOOD. IN LIGHT OF THIS
HAVE RAISED QPF FURTHER NORTH ALONG THE CASCADES FOR TONIGHT.
SNOW LEVELS ARE HOVERING AROUND 4500 FEET AND WITH EXPECTED PCPN WILL
CONTINUE WITH THE WINTER WEATHER ADVISORY FOR SNOW. THE GREATEST
IMPACT SHOULD BE FOR CASCADES PASSES FROM AROUND MT. JEFFERSON TO
WILLAMETTE PASS. SNOWFALL RATES WILL BE ON THE DECREASE EARLY WED
MORNING AS THE LOW DEPARTS FURTHER TO THE EAST.
MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED
TO TAPER OFF LATE TONIGHT AS THE LOW MOVES OFF TO THE E...BUT
ANOTHER TROUGH COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR
SHOWERS GOING WED AFTERNOON AND EVENING. AN UNSTABLE LAYER IN THE
LOW TO MID LEVELS WED AFTERNOON AS SEEN IN MODEL SOUNDINGS AT 00Z
THU INDICATES MARGINALLY UNSTABLE LAYER DEEP ENOUGH TO SUPPPORT A
SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED AFTERNOON. WILL ALSO
CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS AGAIN THU AFTERNOON OVER
THE CASCADES AS THE WEAK TROUGH REMAINS OVER THE AREA IN AT LEAST
SOME MODELS. OTHERWISE RISING HEIGHTS SUGGESTS A WARMER DAY FOR THU
AND FRI. /MH
LONG TERM...FRIDAY NIGHT THROUGH MONDAY...RECENT MODEL RUNS HAVE
SPED UP THE TIMING OF THE WEEKEND FRONT...AND SEEM TO BE SETTLING ON
RAIN AND MOUNTAIN SNOW RETURNING TO THE PACIFIC NORTHWEST FRIDAY
NIGHT.AN UPPER LEVEL TROUGH WILL MAINTAIN SHOWERS THROUGH THE
WEEKEND...ALTHOUGH MOST OF THE SHOWERS WILL BE OVER THE HIGHER
TERRAIN SUNDAY. SNOW LEVELS SHOULD BE AROUND 4000 FEET BEHIND THE
FRONT...LATE FRIDAY NIGHT AND THEN GRADUALLY LOWER THROUGH THE
WEEKEND TO AROUND 2500 FEET. TJ
&&
.AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL
PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE SHORTLY. THIS
SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL LIGHT RAIN
SHOWERS AND MVFR CONDITIONS INTO THE OVERNIGHT HOURS. A BAND OF
HEAVIER PRECIPITATION IS EXPECTED TO FORM OVER THE CENTRAL OREGON
CASCADES AND MAY ALSO MOVE CLOSE ENOUGH TO KSLE AND KEUG TO BRING
MVFR CONDITIONS TO THESE TERMINALS AFTER 00Z WEDNESDAY.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 00Z
THURSDAY. COULD SEE SOME MVFR CIGS OR VIS AROUND SUNRISE
THURSDAY...BUT VFR CONDITIONS WOULD RETURN BY LATE MORNING. BOWEN
&&
.MARINE...A WEAK LOW PRESSURE SYSTEM WILL COME ONSHORE SHORTLY
NEAR THE OREGON/CALIFORNIA BORDER. AS THE LOW MOVES SOUTH AND OUT
OF THE LOCAL AREA...WINDS WILL CONTINUE TO WEAKEN THIS EVENING.
BUILDING HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING TRANQUIL
WIND AND SEAS THROUGH THURSDAY NIGHT.
A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT
SOUTHERLY
WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT WESTERLY WINDS
IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT SWELL OVER
THE WEEKEND. BOWEN/NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR CASCADES IN
LANE COUNTY-NORTHERN OREGON CASCADES.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
239 PM PDT TUE APR 7 2015
.DISCUSSION...THE UPPER LOW CURRENTLY OFF THE COAST IN NORTHWEST CAL
IS MOVING SOUTH. WET SNOW CONTINUES IN SISKIYOU COUNTY, BUT IT`S
BECOMING SHOWERY AND ROADS ARE WET. THE MODELS ARE IN PRETTY GOOD
AGREEMENT SHOWING A DEFORMATION ZONE OF PRECIPITATION SETTING UP
EAST OF THE CASCADES LATER THIS EVENING AND LASTING INTO WEDNESDAY
MORNING, BUT DIFFER SLIGHTLY ON THE PLACEMENT OF THE CORE OF HEAVIEST
QPF. THE LATEST HRRR SHOWS THE DEFORMATION ZONE WELL AND THE
FORECAST FOR TONIGHT WILL LEAN TOWARDS THAT SOLUTION. GIVEN THAT
THIS WILL SET UP AT NIGHT, THERE WILL BE AN OPPORTUNITY FOR SNOW TO
ACCUMULATE ON ROADS DURING THE OVERNIGHT HOURS FOR MOST AREAS EAST OF
THE CASCADES. THE CASCADES WILL ALSO GET ACCUMULATING SNOW TONIGHT,
THUS HAVE EXTENDED THE END TIME OF THE WINTER WEATHER ADVISORY UNTIL
WEDNESDAY MORNING. DETAILS CAN BE FOUND AT WSWMFR. GIVEN THE ABOVE
MENTIONED SCENARIO, HAVE INCREASED POPS...QPF AND SNOW AMOUNTS
SIGNIFICANTLY, BUT IT STILL MAY NOT BE ENOUGH. LATER SHIFTS MAY NEED
TO TAKE ANOTHER LOOK AT THIS AND ADJUST AMOUNTS HIGHER IF LATER
MODEL RUNS CONTINUE TO SHOW THE HIGHER QPF AMOUNTS.
WEDNESDAY WILL BE A TRANSITION DAY WITH THE DEFORMATION ZONE
WEAKENING IN THE MORNING. RAIN AND MOUNTAIN SNOW SHOWERS WILL
CONTINUE IN THE AFTERNOON, BUT SNOW LEVELS WILL COME UP TO AROUND
5000 FEET IN THE AFTERNOON, SO NOT EXPECTING MUCH IF ANY
ACCUMULATIONS FROM ABOUT MID MORNING WEDNESDAY ON DUE TO WARMING
ROAD TEMPERATURES AND SPOTTY PRECIPITATION.
DRY AND MILDER WEATHER FINALLY RETURNS THURSDAY AND CONTINUES INTO
THURSDAY NIGHT WITH SHORTWAVE RIDGING BUILDING INTO THE AREA. MOST
OF FRIDAY WILL BE DRY, THEN THE NEXT FRONT WILL REACH THE COAST
TOWARDS FRIDAY EVENING. THE GFS AND NAM ARE SLOWER WITH THE
ARRIVAL OF THE FRONT WHILE THE EC IS FASTER. FOR NOW WENT WITH A
BLEND BETWEEN THE TWO, BUT THE UPPER FLOW IS WEST OT NORTHWEST
WHICH NORMALLY LEADS TO QUICKER ARRIVAL TIMES OF FRONTS. -PETRUCELLI
THE ACTIVE PATTERN CONTINUES IN THE LONG TERM WITH ANOTHER FRONTAL
BOUNDARY MOVING INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY
MORNING. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE LONG
TERM. THE EC IS A BIT FASTER TO PUSH THE FRONT INLAND ON SATURDAY
COMPARED TO THE GFS BUT BOTH MODELS HAVE IT PUSHED THROUGH THE AREA
BY LATE SATURDAY NIGHT. ZONAL FLOW WILL SET UP FOR SUNDAY AND THE
GFS IS HINTING AT SOME UPSLOPE SHOWERS CONTINUING ALONG THE CASCADES
THROUGH SUNDAY AFTERNOON. THERE MAY ALSO BE SOME LINGERING SHOWERS
FOR THE NORTHERN PORTION OF THE CWA...MAINLY FROM THE UMPQUA DIVIDE
NORTH. OTHERWISE, SUNDAY LOOKS TO BE THE DRIEST DAY, RELATIVELY,
THROUGH THE EXTENDED TERM. BY MONDAY MORNING, THE MODELS ARE
SLIGHTLY DIFFERENT IN THE TIMING AND STRENGTH OF THE NEXT SYSTEM TO
MOVE THROUGH. THE GFS IS FASTER AND DEEPER WITH THE NEXT TROUGH,
MEANING COOLER TEMPERATURES AND LOWER SNOW LEVELS COMPARED TO THE
EC...WHICH IS SLOWER BY ABOUT 12 HOURS AND NOT AS DEEP WITH THE
TROUGH. EITHER WAY, IT LOOKS LIKE UNSETTLED WEATHER WILL CONTINUE
THROUGH THE END OF THE EXTENDED TERM. MND
&&
.AVIATION...FOR THE 07/18Z TAF CYCLE...AS LOW PRESSURE MOVES
INLAND TODAY EXPECT CONTINUED SHOWER ACTIVITY OVER THE. THEN TONIGHT
SHOWERS WILL BECOME MORE CONCENTRATED FROM THE CASCADES EAST AND IN
NORTHERN CALIFORNIA. WITH THESES SHOWERS EXPECT A MIX OF MVFR AND
VFR CIGS ACROSS THE AREA TODAY WITH WIDESPREAD MOUNTAIN
OBSCURATIONS. ISOLATED IFR IS EXPECTED IN SNOW SHOWERS MAINLY NEAR
KMHS. THEN THIS EVENING THROUGH EARLY WEDNESDAY MORNING, EXPECT
MAINLY MVFR CIGS WITH AREAS OF IFR FROM THE CASCADES EAST AS SNOW
SHOWER DEVELOP. WEST OF THE CASCADES, ISOLATED TO SCATTERED SHOWERS
ARE EXPECTED WITH A MIX OF VFR AND MVFR CIGS. THEN EXPECT INCREASING
VFR LATE WEDNESDAY MORNING. /CC
&&
.MARINE...UPDATED 1100 AM PDT TUESDAY APR 07 2015...WINDS AND SEAS
WILL CONTINUE TO DIMINISH TODAY AS LOW PRESSURE MOVES INLAND. SEAS
WILL BE A MIX OF SOUTH WIND CHOP AND WESTERLY SWELL THIS MORNING.
THE SOUTHERLY WIND CHOP WILL DECREASE DURING THE DAY AND WESTERLY
SWELL WILL BECOME DOMINANT. HIGH PRESSURE WILL THEN BUILD INTO THE
WATERS TONIGHT INTO WEDNESDAY AND PERSIST THROUGH THURSDAY NIGHT.
THEN A FRONT WILL MOVE INTO THE WATERS LATE FRIDAY FROM THE
NORTHWEST. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 9 AM PDT
WEDNESDAY FOR ORZ029>031-624-625.
WINTER WEATHER ADVISORY UNTIL 9 AM PDT WEDNESDAY FOR
ORZ027-028-617-621-623.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 9 AM PDT
WEDNESDAY FOR CAZ085-285.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
132 PM PDT TUE APR 7 2015
.SYNOPSIS...A LOW PRES MOVING INTO NORTHERN CALIFORNIA WILL TRACK
EAST INTO NORTHERN NV LATE TONIGHT AND WEDNESDAY. ANOTHER WEAK
TROUGH OF LOW PRES ALOFT WILL MOVE INTO EASTERN WA AND OREGON WED AS
A SURFACE RIDGE OF HIGH PRES STRENGTHENS ALONG THE COAST. THE HIGH
WILL MOVE INLAND WED NIGHT AND THU. THE NEXT PACIFIC FRONTAL SYSTEM
IS EXPECTED TO MOVE DOWN FROM THE GULF OF AK AND PUSH INLAND FRI AND
FRI NIGHT FOR MORE LOWLAND RAIN AND MOUNTAIN SNOW THROUGH THE
WEEKEND.
&&
.SHORT TERM...A VERTICALLY STACKED UPPER LOW JUST MAKING LANDFALL ON
THE NORTH CALIFORNIA COAST THIS AFTERNOON AND CONTINUES TO MOVE
SLOWLY EAST-SOUTHEAST INTO NORTHERN CALIFORNIA. THE FRONT FROM LAST
NIGHT CONTINUES TO DISSIPATE OVER THE NORTHERN ZONES...ROUGHLY FROM
SALEM NORTHWARD. THE NEXT FRONT IS ROTATING AROUND THE SE QUADRANT OF
THE LOW. THE FRONT LOOKS LIKE IT WILL SWING INTO THE CWA AS A
DEFORMATION ZONE AND STALL SOMEWHERE NEAR OVER THE SE ZONES. THE
CENTRAL OREGON CASCADES WILL PROBABLY RECEIVE THE MOST PCPN. THE GFS
AND ECMWF HOLD THE HIGHER PCPN AMOUNTS OVER THE CASCADES OF LINN AND
LANE COUNTIES. HOWEVER THIS MORNING RUNS OF THE HRRR AND NAM HAVE
EXPANDED THE HIGH PCPN AMOUNTS CLOSER TO MT. HOOD. IN LIGHT OF THIS
HAVE RAISED QPF FURTHER NORTH ALONG THE CASCADES FOR TONIGHT.
SNOW LEVELS ARE HOVERING AROUND 4500 FEET AND WITH EXPECTED PCPN
WILL CONTINUE WITH THE WINTER WEATHER ADVISORY FOR SNOW TONIGHT. THE
GREATEST IMPACT WILL BE FOR CASCADES PASSES FROM AROUND MT.
JEFFERSON TO WILLAMETTE PASS. SNOW FALL RATES WILL BE ON THE
DECREASE EARLY WED MORNING AS THE LOW DEPARTS FURTHER TO THE EAST.
MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED
TO TAPER OFF LATE TONIGHT AS THE LOW MOVES OFF TO THE E...BUT
ANOTHER TROUGH COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR
SHOWERS GOING WED AFTERNOON AND EVENING. AN UNSTABLE LAYER IN THE
LOW TO MID LEVELS WED AFTERNOON AS SEEN IN MODEL SOUNDINGS AT 00Z
THU INDICATES MARGINALLY UNSTABLE LAYER DEEP ENOUGH TO SUPPORT A
SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED AFTERNOON. WILL ALSO
CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS AGAIN THU AFTERNOON OVER
THE CASCADES AS THE WEAK TROUGH REMAINS OVER THE AREA IN AT LEAST
SOME MODELS. OTHERWISE RISING HEIGHTS SUGGESTS A WARMER DAY FOR THU
AND FRI. /MH
LONG TERM...FRIDAY NIGHT THROUGH MONDAY...RECENT MODEL RUNS HAVE
SPED UP THE TIMING OF THE WEEKEND FRONT...AND SEEM TO BE SETTLING ON
RAIN AND MOUNTAIN SNOW RETURNING TO THE PACIFIC NORTHWEST FRIDAY
NIGHT.AN UPPER LEVEL TROUGH WILL MAINTAIN SHOWERS THROUGH THE
WEEKEND...ALTHOUGH MOST OF THE SHOWERS WILL BE OVER THE HIGHER
TERRAIN SUNDAY. SNOW LEVELS SHOULD BE AROUND 4000 FEET BEHIND THE
FRONT...LATE FRIDAY NIGHT AND THEN GRADUALLY LOWER THROUGH THE
WEEKEND TO AROUND 2500 FEET. TJ
&&
.AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL
PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE THIS
EVENING. THIS SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL
LIGHT RAIN SHOWERS MVFR CONDITIONS ALONG THE COAST...PARTICULARLY
AT KONP. IN ADDITION...WEAK NORTHERLY FLOW IN THE SOUTHERN
WILLAMETTE VALLEY WILL PRODUCE IFR AND MVFR CONDITIONS AT KEUG
THIS MORNING. A BAND OF HEAVIER PRECIPITATION IS EXPECTED TO FORM
OVER THE CENTRAL OREGON CASCADES AND MAY ALSO MOVE CLOSE ENOUGH
TO KSLE AND KEUG TO BRING MVFR CONDITIONS TO THESE TERMINALS AFTER
00Z WEDNESDAY. THERE IS SOME CHANCE THIS BAND OF PRECIP WILL MOVE
NORTH AND AFFECT THE PDX AREA TERMINALS LATE THIS AFTERNOON AND
EVENING.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 12Z
WEDNESDAY. MODELS ARE STARTING TO SHOW A BAND OF SHOWERS NEAR THE
TERMINAL LATE THIS AFTERNOON AND EVENING WHICH COULD PRODUCE MVFR
CONDITIONS FOR A NUMBER OF HOURS. BOWEN/NEUMAN
&&
.MARINE...A WEAK LOW PRESSURE SYSTEM WILL SLOWLY DRIFT SOUTHWARD
THIS MORNING AND PUSH ASHORE NEAR THE CALIFORNIA/OREGON BORDER
LATE TODAY. THIS WILL RESULT IN WEAKENING WINDS THROUGH THE
MORNING HOURS AND WINDS AT BUOY 29 ARE ALREADY DECREASING. BUILDING
HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING MORE TRANQUIL WIND
AND SEAS THROUGH THURSDAY NIGHT.
A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT
SOUTHERLY WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT
WESTERLY WINDS IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT
SWELL OVER THE WEEKEND.
HIGH PRESSURE LOOKS TO RETURN LATE IN THE WEEKEND BEFORE ANOTHER
SIMILAR STORM SYSTEM ARRIVES EARLY NEXT WEEK...AND POSSIBLY PUSHES
SEAS WELL ABOVE 10 FT ONCE AGAIN. BOWEN/NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 3 AM PDT
WEDNESDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON
CASCADES.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
919 AM PDT TUE APR 7 2015
.DISCUSSION...CURRENT IR IMAGE SHOWS THE UPPER LOW STARTING TO
MOVE INLAND IN NORTHERN CAL. AHEAD OF THE LOW IS A BAND OF
MODERATE TO HEAVY PRECIPITATION ORIENTATED FROM SOUTHEAST TO
NORTHWEST INTO SISKIYOU COUNTY. MODERATE TO HEAVY SNOW HAS FALLEN
IN THE MOUNT SHASTA REGION INCLUDING MOUNT SHASTA CITY...TENNANT
AND IN WESTERN SISKYIOU COUNTY ABOVE 3000 FEET. SPOTTER REPORTS
HAVE BEEN COMING IN THIS MORNING AND THE BIG WINNER SO FAR HAS
BEEN 13.5 INCHES 6 MILES WEST OF BLACK BUTTE SUMMIT...7 INCHES AT
BLACK BUTTE SUMMIT...6 INCHES 2 MILES WEST OF WEED AND 5 INCHES
NEAR THE WEST SHORE OF IRON GATE LAKE. ROAD CAMS THIS MORNING SHOW
SNOW COVERED ROADS ALONG I-5 JUST SOUTH OF WEED TO
DUNSMUIR...HIGHWAY 89 AND HIGHWAY 97. SNOW IS EXPECTED TO CONTINUE
THIS MORNING, BUT THE MODELS SUGGEST SNOW WILL GRADUALLY DECREASE
THIS AFTERNOON. THIS ALONG WITH WARMING ROAD TEMPERATURES SHOULD
ALLOW ROADS TO BECOME WET IN THE AFTERNOON. CURRENT WINTER STORM
WARNING GOES OUT UNTIL 5 PM PDT, BUT WE COULD END THIS EARLIER IF
THERE`S ENOUGH EVIDENCE TO SUGGEST WE`LL NO LONGER HAVE ANY ROAD
SNOW CONCERNS.
THE NAM AND HRRR SHOWS PRECIPITATION INCREASING ALONG THE
CASCADES THIS AFTERNOON AND LASTING INTO THIS EVENING WITH SNOW
LEVELS HOVERING AROUND 4000 FEET, BUT COULD BRIEFLY LOWER TO 3500
FEET IN HEAVIER SHOWERS. MOST ROADS ARE WET IN THIS AREA EXCEPT
FOR CRATER LAKE AND DIAMOND LAKE, BUT SLUSH OR SNOW COVERED ROADS
ARE POSSIBLE THIS AFTERNOON AS PRECIP RATES INCREASE.
MADE A FEW ADJUSTMENTS TO THE FORECAST TODAY, BUT THE OVERALL IDEA
REMAINS THE SAME. -PETRUCELLI
&&
.AVIATION...FOR THE 07/12Z TAF CYCLE...STRONG LOW PRESSURE AND A
COLD FRONT WILL MOVE ACROSS NORTHERN CALIFORNIA THIS MORNING. THIS
WILL RESULT IN HEAVY SNOW OVER THE MOUNTAINS AND RAIN IN THE LOWER
ELEVATIONS WITH WIDESPREAD IFR CONDITIONS AND MOUNTAIN OBSCURATIONS
SPREADING WEST TO EAST ACROSS NORTHERN CALIFORNIA. IN OREGON, WEST
SIDE RAIN SHOWERS AND EAST SIDE SNOW SHOWERS WITH MVFR CIGS WILL BE
COMMON AS WILL MOUNTAIN OBSCURATIONS. DOWNSLOPING WILL LIKELY KEEP
RAIN FROM REACHING KMFR UNTIL AROUND DAWN, BUT THIS WILL ALSO RESULT
IN LOW LEVEL WIND SHEAR AT KMFR EARLY THIS MORNING. -SVEN
&&
.MARINE...UPDATED 350 AM PDT TUESDAY APR 07 2015... LOW PRESSURE AND
A COLD FRONT WILL MOVE INLAND TODAY. BOTH WINDS AND SEAS WILL
DIMINISH THIS MORNING AS LOW PRESSURE MOVES INLAND. HIGH PRESSURE
WILL THEN BUILD IN WEDNESDAY AND PERSIST THROUGH FRIDAY WITH WEAK
WINDS AND LIGHT TO MODERATE WESTERLY SWELL.
&&
.PREV DISCUSSION... /ISSUED 355 AM PDT TUE APR 7 2015/
DISCUSSION...OBSERVATIONS OVER THE PAST SEVERAL HOURS HAVE SHOWN
A STEADY RAIN ALONG THE COAST, PARTICULARLY AT BROOKINGS AND
CRESCENT CITY, AND INLAND TO THE COASTAL RANGES AND THE SISKIYOU
MOUNTAINS. THIS BAND OF HEAVIER PRECIPITATION WILL PUSH INLAND
THROUGH THIS MORNING, ALTHOUGH PROGRESSION WILL BE SLOW AS THE
SURFACE LOW WILL BEGIN TO WEAKEN AND MEANDER ABOUT A BIT BEFORE IT
FINALLY MOVES ONSHORE AND ALMOST COMPLETELY DISSIPATES.
WITH SNOW LEVELS HOVERING BETWEEN 3000 AND 4000 FEET, HEAVY SNOW
AMOUNTS ARE STILL EXPECTED OVER MANY PORTIONS OF NORTHERN
CALIFORNIA TODAY. WINTER WEATHER HEADLINES WILL CONTINUE THERE,
ALTHOUGH WITH THE LATEST MODEL SOLUTIONS SUGGESTING THE SYSTEM IS
SLOWING A BIT, HAVE EXTENDED THE WARNINGS AND ADVISORIES IN
SISKIYOU COUNTY BY AN ADDITIONAL SIX HOURS. THOSE SAME MODELS ARE
ALSO SHOWING AN AREA OF HEAVIER PRECIPITATION PUSHING NORTH ALONG
THE CASCADES OF OREGON. AS MANY OF THE HIGHER RESOLUTION MODELS,
AS WELL AS THE GFS, ARE DEPICTING THIS TREND, HAVE PUSHED QPF UP
ALONG THE CASCADES, AND CONSEQUENTIALLY, HAVE BUMPED UP SNOW
AMOUNTS AS WELL. THIS HAS RESULTED IN SNOW ACCUMULATIONS
APPROACHING 6 INCHES OVER A PERIOD OF ABOUT 12 HOURS THIS
AFTERNOON NEAR CRATER AND DIAMOND LAKES, AS WELL AS NEAR LAKE OF
THE WOODS AND MT ASHLAND, SO HAVE DECIDED TO ISSUE A WINTER
WEATHER ADVISORY TO COVER THE POSSIBLE TRAVEL DIFFICULTIES ALONG
THE CASCADE PASSES. FOR MORE INFORMATION REGARDING THIS ADVISORY
AND THE WARNING AND ADVISORIES FOR SISKIYOU COUNTY, SEE THE WINTER
WEATHER MESSAGE.
SNOW IS ALSO EXPECTED TODAY ACROSS MUCH OF THE EAST SIDE. SNOW
AMOUNTS SHOULD BE LIGHT, AND GIVEN THE WARM SURFACE TEMPERATURES,
DO NOT EXPECT SIGNIFICANT ACCUMULATIONS ON AREA ROADS. HOWEVER,
WINDS MAY RESULT IN BRIEF PERIODS OF LOWERED VISIBILITIES IN
BLOWING SNOW. THIS IS ALSO TRUE FOR THE SHASTA VALLEY TODAY, WHERE
GUSTY WINDS AND SNOW COULD RESULT IN GREATLY LOWERED VISIBILITIES
ALONG INTERSTATE 5.
THE SURFACE LOW, AND ITS ASSOCIATED TROUGH, WILL SLIDE EAST OUT
OF THE AREA LATE TONIGHT AND INTO WEDNESDAY MORNING. ISOLATED TO
SCATTERED SHOWERS ARE LIKELY TO LINGER IN THE AREA THROUGH THE
EARLY AFTERNOON, BUT MOST OF THE FORECAST AREA WILL SEE THE END OF
PRECIPITATION BY LATE MORNING. A BRIEF PERIOD OF RIDGING WILL HELP
TO BRING WARMER TEMPERATURES AND DRY CONDITIONS TO THE REGION
THURSDAY AND INTO FRIDAY, BUT ANOTHER STORM SYSTEM IS EXPECTED TO
BRING MORE RAIN AND COOLER TEMPERATURES FRIDAY AFTERNOON INTO
SATURDAY. SNOW LEVELS WITH THIS FASTER MOVING SYSTEM SHOULD REMAIN
ABOVE 4500 FEET, SO WIDESPREAD SNOW LIKE WE ARE SEEING TODAY IS
NOT EXPECTED. THE GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE
TIMING OF THE FRONTAL PASSAGE, SO HAVE BUMPED UP PRECIPITATION
CHANCES TO LIKELY FOR SATURDAY.
ANOTHER SYSTEM IS EXPECTED EARLY NEXT WEEK, MOST LIKELY MONDAY
NIGHT OR TUESDAY. THERE IS STILL A GOOD DEAL OF UNCERTAINTY
REGARDING THE DETAILS, BUT MODELS ARE IN REMARKABLY GOOD AGREEMENT
GIVEN THE TIME RANGE. GUIDANCE ALSO SUGGESTS THAT THIS SYSTEM WILL
INVOLVE A COLDER AIR MASS, SO THERE IS THE POTENTIAL FOR ANOTHER
SNOW EVENT, MUCH LIKE TODAY. STAY TUNED FOR UPDATES THROUGH THE
WEEK.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 8 PM PDT THIS EVENING FOR
ORZ027-028-617-621-623.
WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON ABOVE 3000
FEET FOR FOR ORZ621.
CA...WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR
CAZ081-281.
WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON ABOVE 3000
FEET FOR FOR CAZ080-280.
WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR
CAZ082-282.
WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR
CAZ083-284.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
900 AM PDT TUE APR 7 2015
.SYNOPSIS...A LOW PRES OFF THE S OREGON COAST TUE MORNING WILL MOVE
S AND THEN E TODAY AND TONIGHT...MOVING INLAND ACROSS NORTHERN CA
AND NV. ANOTHER WEAK TROUGH OF LOW PRES ALOFT WILL MOVE S OVER
EASTERN WA AND OREGON WED AS A SURFACE RIDGE OF HIGH PRES
STRENGTHENS ALONG THE COAST. THE HIGH WILL MOVE INLAND WED NIGHT AND
THU. THE NEXT PACIFIC FRONTAL SYSTEM IS EXPECTED TO MOVE DOWN FROM
THE GULF OF AK AND PUSH INLAND FRI AND FRI NIGHT.
&&
.UPDATE...A LOW OFFSHORE CONTINUES TO BRING BANDS OF RAIN ACROSS THE
AREA TODAY. THE FIRST BAND NOW OVER THE NORTHERN OREGON ZONES THIS
MORNING CONTINUES TO PERSIST SO HAVE ADJUSTED FORECAST TO MATCH.
MODELS SHOW THIS BAND WEAKENING THIS AFTERNOON AS ANOTHER DEFORMATION
BAND NOW SEEN IN ITS EARLY STAGES ON THE SE QUADRANT OF THE LOW OFF
THE NORTHERN CALIFORNIA COAST.MONDAYS MODELS HAD THE MAIN FOCUS OF
THE PCPN WITH THIS BAND OVER EASTERN LINN AND LANE COUNTY FOR THIS
AFTERNOON AND TONIGHT.THIS MORNING SOME MODELS LIKE THE HRRR ARE
FOCUSING THE HEAVIER PCPN FURTHER NORTH FOR THIS EVENING SO SOME
ADJUSTMENTS MAY BE NEEDED TO THE FORECAST. IF THE HRRR IS CORRECT THE
HEAVIER SNOWFALL IN THE CASCADES MAY VERY WELL BE IN THE NORTH
CASCADES VS. THE CENTRAL CASCADES. MODELS GENERALLY AGREE IN
WEAKENING THE BAND LATE TONIGHT AND WED.
PREVIOUS DISCUSSION...
SHORT TERM...MAIN UPPER LOW SEEN IN WATER VAPOR PICTURES EARLY TUE
MORNING WAS NEAR 42N 128W...STILL MOVING SLOWLY S. A WEAKENING
DEFORMATION BAND OF LIGHT RAIN REMAINED ACROSS SW WA AND THE EXTREME
NW CORNER OF OREGON...AND IS EXPECTED TO CONTINUE TO FIZZLE OUT THIS
MORNING. WHILE THE FOCUS FOR PRECIPITATION WITH THIS LOW REMAINS TO
THE S...SOME SHOWERS EXPECTED TO CONTINUE TO ROTATE AROUND THE N
PART OF THE LOW TODAY AND TONIGHT AS THE LOW TURNS E AND MOVES
INLAND ACROSS NORTHERN CA. MODELS GENERALLY SHOWING AN ENHANCED AREA
OF PRECIPITATION OVER THE SE PART OF THE FORECAST AREA LATE TODAY
AND INTO TONIGHT...GENERALLY OVER THE OREGON PART OF THE CASCADES S
OF MT JEFFERSON. GFS AND NAM SUGGEST THE ENHANCED PRECIPITATION IS
RELATED TO AN AREA OF DEFORMATION ON THE N SIDE OF THE LOW AS IT
MOVES BY TO THE S. GIVEN THE GOOD AGREEMENT IN MODELS SHOWING THIS
QPF FIELD...AND WITH SNOW LEVELS STILL AT OR A LITTLE BELOW PASS
LEVELS...WILL GO AHEAD WITH A WINTER WEATHER ADVISORY FOR SNOW THERE
ABOVE 4500 FT LATE THIS AFTERNOON AND CONTINUING PAST MIDNIGHT.
MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED
TO END WED MORNING AS IT MOVES OFF TO THE E...BUT ANOTHER TROUGH
COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR SHOWERS GOING
WED AFTERNOON AND EVENING. THIS UPPER TROUGH HAS AN INLAND TRACK
COMING DOWN FROM BC WHICH IS NORMALLY DRY...BUT A LOW LEVEL ONSHORE
FLOW WILL KEEP ENOUGH MOISTURE AVAILABLE TO GENERATE AN UNSTABLE
LAYER IN THE LOW TO MID LEVELS WED AFTERNOON. A LOOK AT MODEL
SOUNDINGS AT 00Z THU INDICATES UNSTABLE LAYER MAY BE MARGINALLY DEEP
ENOUGH TO SUPPORT A SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED
AFTERNOON...SO WILL MAINTAIN THE SLIGHT CHANCE THERE BUT PULL IT
FROM AREAS FURTHER W. WILL CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS
AGAIN THU AFTERNOON OVER THE CASCADES AS THE WEAK TROUGH REMAINS
OVER THE AREA IN AT LEAST SOME MODELS. OTHERWISE RISING HEIGHTS
SUGGESTS A WARMER DAY FOR THU.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. THURSDAY NIGHT
THROUGH SUNDAY...WHAT RESIDUAL SHOWERS THAT FORM THURSDAY AFTERNOON
WILL CLEAR THURSDAY NIGHT. THE MODELS ARE COMING INTO BETTER
AGREEMENT WITH THE NEXT FRONT BEGINNING TO MOVE ONSHORE AND SPREAD
RAIN ONSHORE ON FRIDAY...AND MOVING THROUGH SOUTHWEST WASHINGTON AND
NORTHWEST OREGON FRIDAY NIGHT. SNOW LEVELS ARE FORECAST TO RISE
ABOVE THE CASCADE PASSES FRIDAY BEFORE FALLING BELOW THE PASSES
FRIDAY NIGHT AND STAYING WELL BELOW THE PASSES OVER THE WEEKEND AS
BRISK ONSHORE FLOW SPREADS COOL SHOWERY AIR ONSHORE AND LIKELY GIVES
THE CASCADES ANOTHER GOOD DOSE OF SNOW. THE ECMWF MODEL HAS THE
BRUNT OF THE ONSHORE FLOW FARTHER NORTH THAN THE GFS AND NAM12
MODELS...SO THAT IS THE MAIN UNCERTAINTY ABOUT CASCADE SNOW FOR THIS
WEEKEND AT THIS POINT. ANOTHER PACIFIC FRONT IS POSSIBLE EARLY NEXT
WEEK...CONTINUING THE CURRENT EARLY SPRING PATTERN. TOLLESON &&
.AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL
PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE THIS
EVENING. THIS SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL
LIGHT RAIN SHOWERS MVFR CONDITIONS ALONG THE COAST...PARTICULARLY
AT KONP. IN ADDITION...WEAK NORTHERLY FLOW IN THE SOUTHERN
WILLAMETTE VALLEY WILL PRODUCE IFR AND MVFR CONDITIONS AT KEUG
THIS MORNING. A BAND OF HEAVIER PRECIPITATION IS EXPECTED TO FORM
OVER THE CENTRAL OREGON CASCADES AND MAY ALSO MOVE CLOSE ENOUGH
TO KSLE AND KEUG TO BRING MVFR CONDITIONS TO THESE TERMINALS AFTER
00Z WEDNESDAY. THERE IS SOME CHANCE THIS BAND OF PRECIP WILL MOVE
NORTH AND AFFECT THE PDX AREA TERMINALS LATE THIS AFTERNOON AND
EVENING.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 12Z
WEDNESDAY. MODELS ARE STARTING TO SHOW A BAND OF SHOWERS NEAR THE
TERMINAL LATE THIS AFTERNOON AND EVENING WHICH COULD PRODUCE MVFR
CONDITIONS FOR A NUMBER OF HOURS. BOWEN/NEUMAN
&&
.MARINE...A WEAK LOW PRESSURE SYSTEM WILL SLOWLY DRIFT SOUTHWARD
THIS MORNING AND PUSH ASHORE NEAR THE CALIFORNIA/OREGON BORDER
LATE TODAY. THIS WILL RESULT IN WEAKENING WINDS THROUGH THE
MORNING HOURS AND WINDS AT BUOY 29 ARE ALREADY DECREASING. BUILDING
HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING MORE TRANQUIL WIND
AND SEAS THROUGH THURSDAY NIGHT.
A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT
SOUTHERLY
WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT WESTERLY WINDS
IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT SWELL OVER
THE WEEKEND.
HIGH PRESSURE LOOKS TO RETURN LATE IN THE WEEKEND BEFORE ANOTHER
SIMILAR STORM SYSTEM ARRIVES EARLY NEXT WEEK...AND POSSIBLY PUSHES
SEAS WELL ABOVE 10 FT ONCE AGAIN. BOWEN/NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 3 AM PDT
WEDNESDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON
CASCADES.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1138 PM EDT WED APR 8 2015
.SYNOPSIS...
A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA
AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST
AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM
SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER
A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS
NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. REGIONAL
RADAR LOOP AT 03Z SHOWS A CLUSTER OF SHRA/TSRA APPROACHING SW PA
IN ADVANCE OF WEAK SHORTWAVE LIFTING THRU THE OHIO VALLEY. BASED
ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY POPS
BTWN 05Z-08Z ACROSS SOUTHERN SOMERSET/BEDFORD COUNTIES. THIS AREA
WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC
WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM
SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. ELSEWHERE...OUTSIDE OF
SOME PATCHY DRIZZLE...THE BALANCE OF THE NIGHT LOOKS DRY ACROSS
MOST OF CENTRAL PA.
BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS
IN THE UPPER 30S TO LOW 40S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA
REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF
SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC
WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX
VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED
ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS
THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY.
LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY
DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR
WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE
PROXIMITY TO STATIONARY FRONT. AREAS WEST OF THIS BOUNDARY SHOULD BE
PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM
AND 0-1KM LAYERS.
HIGHS SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST
OF THE ALLEGHENY FRONT WILL LIKELY GET INTO THE 50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS.
MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB
FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW
IS EXPECTED ACROSS THE AREA.
ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT
850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR
AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST
MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST.
LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS
IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT
THE BEST HEIGHT FALLS.
ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG
THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT.
ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER
STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE
FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT
IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL
KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY.
LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL
BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED.
WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH
THE PERIOD.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/MARTIN
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...MARTIN
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 PM EDT WED APR 8 2015
.SYNOPSIS...
A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA
AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST
AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM
SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER
A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS
NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. REGIONAL
RADAR LOOP AT 03Z SHOWS A CLUSTER OF SHRA/TSRA APPROACHING SW PA
IN ADVANCE OF WEAK SHORTWAVE LIFTING THRU THE OHIO VALLEY. BASED
ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY POPS
BTWN 05Z-08Z ACROSS SOUTHERN SOMERSET/BEDFORD COUNTIES. THIS AREA
WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC
WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM
SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. ELSEWHERE...OUTSIDE OF
SOME PATCHY DRIZZLE...THE BALANCE OF THE NIGHT LOOKS DRY ACROSS
MOST OF CENTRAL PA.
BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS
IN THE UPPER 30S TO LOW 40S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA
REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF
SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC
WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX
VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED
ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS
THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY.
LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY
DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR
WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE
PROXIMITY TO STATIONARY FRONT. AREAS WEST OF THIS BOUNDARY SHOULD BE
PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM
AND 0-1KM LAYERS.
HIGHS SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST
OF THE ALLEGHENY FRONT WILL LIKELY GET INTO THE 50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS.
MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB
FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW
IS EXPECTED ACROSS THE AREA.
ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT
850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR
AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST
MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST.
LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS
IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT
THE BEST HEIGHT FALLS.
ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG
THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT.
ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER
STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE
FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT
IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL
KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY.
LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL
BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED.
WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH
THE PERIOD.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/MARTIN
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
728 PM EDT WED APR 8 2015
.SYNOPSIS...
A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA
AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST
AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM
SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER
A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS
NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. MAIN
FEATURE OF NOTE THIS EVENING IS WELL DEFINED SHORTWAVE/MCV
TRACKING ACROSS SOUTHERN PA. REGIONAL RADAR LOOP AT 21Z SHOWS
WEAKENING CONVECTION MOVING INTO THE ALLEGHENY MTNS AS IT
ENCOUNTERS COOL/STABLE AIR MASS. HOWEVER...LG SCALE FORCING AHEAD
OF THIS FEATURE WILL LIKELY SUPPORT A PERIOD OF SHOWERS ACROSS
MOST OF CENTRAL PA AS IT MOVES THRU THIS EVENING. RADAR TRENDS AND
LATEST HRRR OUTPUT SUGGEST THE SHOWERS WILL BE EXITING THE EASTERN
COUNTIES BY ARND 03Z.
IN THE WAKE OF THIS EVENING/S SHORTWAVE...EXPECT DRY CONDS FOR
MOST OF THE REGION LATE TONIGHT. THE EXCEPTION WILL BE ACROSS THE
SOUTHWEST COUNTIES...WHERE SHOWERS MAY ARRIVE TOWARD DAWN IN ASSOC
WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM
SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST.
BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS
RANGING FROM THE U30S OVR THE HIGH TERRAIN NORTH AND EAST OF
KIPT...TO THE M40S ALONG THE SPINE OF THE ALLEGHENY MTNS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA
REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF
SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC
WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX
VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED
ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS
THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY.
LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY
DAMMED. HOWEVER...ELEVATED TSRA A DEFINITE POSSIBILITY ACROSS THE
NW COUNTIES LATE IN THE DAY.
HIGHS WILL BE WITHIN A DEGREE OR TWO OF TODAY IN MOST AREAS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS.
MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB
FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW
IS EXPECTED ACROSS THE AREA.
ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT
850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR
AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST
MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST.
LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS
IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT
THE BEST HEIGHT FALLS.
ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG
THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT.
ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER
STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE
FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT
IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL
KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY.
LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL
BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED.
WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH
THE PERIOD.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/MARTIN
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
535 PM EDT TUE APR 7 2015
.SYNOPSIS...
A FRONTAL BOUNDARY DRAPED OVER CENTRAL PA WILL DRIFT SLOWLY TO
THE SOUTH TONIGHT THROUGH THURSDAY. MOIST AIR STREAMING NE ABOVE
A SHALLOW AND COOL AIRMASS DROPPING SOUTHWARD BEHIND THE FRONT
WILL BRING PERIODS OF A SHOWERS OVER THE NEXT SEVERAL DAYS. A BIT
OF LIGHT FREEZING RAIN IS EVEN POSSIBLE AT SOME HIGHER ELEVATIONS
THROUGHOUT CENTRAL AND NORTHEASTERN PA LATE WEDNESDAY NIGHT INTO
EARLY THURSDAY...AS STRENGTHENING HIGH PRESSURE BUILDING ACROSS
QUEBEC PUMPS COLD AIR SOUTH INTO THE REGION. A DEEP STORM SYSTEM
LIFTING ACROSS THE GREAT LAKES ON FRIDAY WILL BRING WARMER
CONDITIONS BACK INTO THE AREA...WITH A CHANCE OF THUNDERSTORMS.
A COLD FRONT WILL BE FOLLOWED BY COLDER TEMPERATURES FOR THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
BULK OF THE RAIN SHOWERS PUSHING EAST OF THE SUSQ RIVER AS OF 21Z
IN ADVANCE OF WEAK MID LVL SHORTWAVE OVR THE CENTRAL PART OF THE
STATE. RADAR TRENDS AND LATEST HRRR SUGGEST THE STEADIEST RAIN
WILL EXIT THE EASTERN COUNTIES BY ARND 00Z. AT THE SFC...BACK DOOR
COLD FRONT IS PUSHING THRU SOUTHERN PA AT 21Z AND SHOULD PRESS
SOUTH OF THE MASON DIXON LINE THIS EVENING. A MOIST...EASTERLY
FLOW NORTH OF THIS BOUNDARY WILL LIKELY PRODUCE OCNL DRIZZLE
ACROSS CENTRAL PA LATER TONIGHT. IN ADDITION...UPSTREAM SHORTWAVE
OVR THE LOWER GRT LKS WILL LIFT THRU LATER TONIGHT...BRINGING SCT
SHRA. WILL CONTINUE TO CARRY LIKELY POPS EVERYWHERE TONIGHT...ALTHOUGH
AMOUNTS ARE NOT EXPECTED TO BE SUBSTANTIAL. GENERALLY A TRACE TO A
FEW HUNDRETHS IN MOST AREAS...UP TO A TENTH IN SOME LOCATIONS.
1038 MB SFC HIGH SPREADING EASTWARD FROM ONTARIO TO QUEBEC WILL
INDUCE CAD ACROSS EASTERN PA OVERNIGHT WITH COOLER LLVL TEMPS
BLEEDING SOUTHWARD INTO WEDNESDAY MORNING. READINGS BY DAWN
SHOULD RANGE FROM THE U30S OVR THE HIGH TERRAIN NORTH AND EAST OF
KIPT...TO THE M40S OVR THE SOUTHERN COUNTIES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
COOL AND DANK CONDITIONS WILL BE THE NORM ON WEDNESDAY IN CAD
REGIME WITH PLENTY OF LLVL MOISTURE AND OVERRUNNING ZONAL FLOW
ALOFT PROMOTING LIGHT SHOWERS ESPECIALLY IN THE AFTERNOON. HIGHS
WILL RANGE THROUGH THE 40S FOR MOST...BUT AREAS ALONG THE
ALLEGHENY FRONT MAY NUDGE INTO THE WARM SECTOR WITH WESTERN WARREN
AND WESTERN SOMERSET COUNTIES REACHING INTO THE 50S AND PERHAPS
NEAR 60 ACROSS SOUTHWEST SOMERSET COUNTY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
DID NOT CHANGE POPS OR WEATHER FOR WED NIGHT...GIVEN SLIGHT
CHANCE FOR A LITTLE FREEZING DRIZZLE OR RAIN ACROSS THE NE.
LOWS NEAR HUDSON AND JAMES BAY AREA WERE ZERO TO 20 BELOW
THIS MORNING. THAT IS COLD FOR EARLY APRIL.
DETAILS BELOW...
GIVEN THE FACT THAT WE/LL HAVE A 1040 MB SFC HIGH BECOMING PARKED
ACROSS SRN QUEBEC /WHERE CURRENT TEMPS ARE IN THE SINGLE DIGITS TO
TEENS/ AND 1000 MB AGEOSTROPIC FLOW INCREASING FROM THE
NORTH-NORTHEAST /AND STAYING THERE FOR A 24-36 HOURS PERIOD/...WENT
SEVERAL DEG F BELOW MODEL TEMPS FOR WED MAXES AND WED NIGHT MINS.
EVEN MENTIONED A SLIGHT CHC FOR LIGHT FZRA ACROSS PARTS OF THE
NCENT MTNS AND WRN POCONOS LATE WED NIGHT AND EARLY THURSDAY.
THIS LLVL COLD AIR DAMMING LIKELY TO LINGER INTO THURSDAY AFT.
SOME NEW DETAIL BELOW...
WHILE TEMPS MAY NOT WARM REAL GOOD THU...AND I LEFT THEM
CLOSE TO WHAT WE HAD...WILL CONTINUE TO MONITOR. VERY TIGHT
TEMPERATURE GRADIENT AT 850 MB LATE WED EVENING ACROSS CENTRAL
NY...MINUS 4 TO PLUS 10 IN ABOUT 80 TO 100 MILE BAND.
ANYWAY...WARMER AIR WILL WORK INTO THE AREA LATE THU INTO
FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES
MIGHT END UP BEING ACROSS WARREN COUNTY.
DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS
THE AREA RATHER FAST.
SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY.
THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE.
HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY
FROM THE AREA. ALSO TIMING NOT THE BEST.
WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY
LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS
POINT. ENJOY THE MILDER TEMPERATURES.
RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT.
TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO
LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH
AND COLD ADVECTION.
WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER
ON SUNDAY.
DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE
AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
BANDS OF SCATTERED LIGHT SHOWERS CONTINUE TO STREAM EASTWARD OVER
CENTRAL PA THIS MORNING. AS A FRONT CONTINUES TO PUSH EVER SO
SLOWLY SOUTHWARD...MVFR RESTRICTIONS WILL CONTINUE TO SAG
SOUTHWARD THROUGH THE DAY. IFR CONDITIONS WILL AFFECT THE NORTHERN
MTNS AS FRONT PUSHES INTO HIGH DEWPOINT AIR. ONCE THESE IFR/MVFR
RESTRICTIONS ARRIVE IN A LOCATION...THEY WILL THEN PERSIST FOR AN
EXTENDED PERIOD AS UNSETTLED WEATHER IMPACTS THE REGION THROUGH
THE WEEK.
MARGINAL CAPE MAY BRING ISOLATED THUNDER TO THE SOUTHERN TIER OF
CENTRAL PA THROUGH THIS EVENING. WINDS WILL REMAIN LIGHT INTO
WED.
OUTLOOK...
WED...WIDESPREAD MVFR/IFR IN SHRA/PERIODS OF RA.
THU...REDUCTIONS LIKELY IN SCT SHRA.
FRI...REDUCTIONS LIKELY IN SHRA...ESPECIALLY DURING THE
AFT. CHC OF THUNDER AFT.
SAT-SUN...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...LAMBERT/MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1028 PM EDT WED APR 8 2015
.SYNOPSIS...
M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH
THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO
CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF
SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE
REGION THIS WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1000 PM...THE LATEST SPC MESOANALYSIS PAGE STILL SHOWS
1000-2000 J/KG OF MUCAPE. A COUPLE OF ISOLD TSTMS HAVE POPPED UP IN
THE MIDLANDS...AND THE LAST COUPLE OF HRRR RUNS DO SHOW A FEW MORE
CELLS DEVELOPING OVER THE NEXT FEW HOURS SOUTH OF I-85. SO WILL ADD
A SLGT CHC BACK IN ACRS THE SOUTHEASTERN ZONES. CANNOT RULE OUT A
SEVERE PULSE STORM GIVEN THE CAPE AND 25-30 KTS OF EFFECTIVE SHEAR.
OTHERWISE...THE REST OF THE FCST LOOKS ON TRACK.
AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE
ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT
BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR
THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN.
TEMPS/SKY/WINDS ARE ON TRACK.
AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS
THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING
INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF
SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE
AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN
TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING
MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE
EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY
PRECIP...IF THE LATEST TRENDS HOLD.
AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN
THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS
THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL
APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX
MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE
WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST
FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA.
SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO
BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE
SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING
SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION
ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW
LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT
VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER
LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED
SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES
CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH
LARGE HAIL AND DAMAGING WINDS.
UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL
SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE
ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON
THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE
REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS
AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN
1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK
OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING
IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST
TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY
VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO
EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL
THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE
POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL
DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES
CLOSER TO ANY SHORTWAVE ACTIVITY.
TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT...
WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS
THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL
IN FAIRLY GOOD AGREEMENT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES
TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD
FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL
STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW
STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS
A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING
SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING
REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE
PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT
AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE
DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION
AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE
POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT.
WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG
THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS
WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND
SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE
NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND
850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR
AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT
DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB
A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON
THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL
THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION...
ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE
HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN
BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS
POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS
AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST
AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN
THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP
CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE.
ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A
NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD
IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE
RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW
DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A
DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE
UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO
REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK
SHORT WAVES MOVING THRU THE FLOW.
AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH
POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE
MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES
EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING
DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA
ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW
REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND
ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY
DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE
NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS CONTINUE TO BE TRANQUIL ACRS THE AREA HEADING
INTO THIS EVENING. BASED ON THE LATEST GUIDANCE AND RADAR/SAT
TRENDS...EXPECT CONVECTION TO REMAIN WELL NORTH AND EAST OF THE
TERMINAL OVERNIGHT. WINDS WILL BE CALM OR LIGHT SOUTH WITH GENERALLY
THIN CIRRUS OVERHEAD. SOME OF THE GUIDANCE STILL INDICATES IFR CIGS
AND SPOTTY VSBY/FOG RESTRICTIONS. HOWEVER...GIVEN NO RAIN FELL
TODAY...AND PERIODS OF HIGH CLOUDS...WILL REMOVE MENTION OF LOW
CLOUDS WITH THE 00Z TAF. ON THURSDAY...THE ATMOSPHERE ACTUALLY LOOKS
LESS UNSTABLE...WITH LACK OF A TRIGGER FOR CONVECTION ONCE AGAIN.
HOWEVER...BY LATE AFTN GUIDANCE DOES SHOW SCATTERED CONVECTION
DEVELOPING ACRS WESTERN NC. SO WILL ADD A PROB30 FOR TSRA STARTING
AROUND 19Z. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW
THURSDAY AFTN.
ELSEWHERE...SIMILAR TO KCLT DISCUSSION ABOVE. GIVEN LACK OF RAIN
TODAY AND WARM OVERNIGHT TEMPS UNDER PERIODS OF CIRRUS CIGS...EXPECT
ONLY PATCHY HZ/BR OVERNIGHT...PRIMARILY AT KAVL AND KHKY.
OTHERWISE...EXPECT VFR CONDITIONS. ON THURSDAY...GUIDANCE ONCE AGAIN
DEVELOPS CONVECTION DURING THE PEAKING HEATING AFTN HOURS.
HOWEVER...THE ATMOSPHERE LOOKS LESS UNSTABLE WITH STILL A LACK OF
TRIGGER LIKE TODAY. WILL ADD PROB30 FOR TSRA FOR NOW. WINDS WILL BE
A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN.
OUTLOOK...A COLD FRONT WILL PUSH THROUGH LATE FRIDAY...BRING WITH IT
THE POTENTIAL FOR AT LEAST SCATTERED CONVECTION. WITH AFTERNOON
CONVECTION WILL FOLLOW POTENTIAL FOR RESTRICTIONS IN THE MORNING.
MUCH IMPROVED CONDITIONS FOR THE WEEKEND AFTER THE FRONT CLEARS THE
AREA.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT HIGH 100% MED 69% HIGH 98% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% MED 74% HIGH 96% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...ARK/TDP
SHORT TERM...PM
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
746 PM EDT WED APR 8 2015
.SYNOPSIS...
M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH
THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO
CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF
SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE
REGION THIS WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE
ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT
BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR
THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN.
TEMPS/SKY/WINDS ARE ON TRACK.
AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS
THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING
INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF
SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE
AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN
TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING
MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE
EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY
PRECIP...IF THE LATEST TRENDS HOLD.
AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN
THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS
THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL
APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX
MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE
WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST
FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA.
SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO
BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE
SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING
SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION
ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW
LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT
VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER
LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED
SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES
CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH
LARGE HAIL AND DAMAGING WINDS.
UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL
SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE
ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON
THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE
REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS
AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN
1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK
OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING
IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST
TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY
VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO
EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL
THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE
POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL
DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES
CLOSER TO ANY SHORTWAVE ACTIVITY.
TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT...
WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS
THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL
IN FAIRLY GOOD AGREEMENT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES
TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD
FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL
STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW
STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS
A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING
SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING
REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE
PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT
AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE
DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION
AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE
POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT.
WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG
THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS
WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND
SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE
NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND
850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR
AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT
DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB
A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON
THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL
THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION...
ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE
HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN
BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS
POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS
AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST
AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN
THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP
CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE.
ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A
NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD
IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE
RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW
DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A
DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE
UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO
REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK
SHORT WAVES MOVING THRU THE FLOW.
AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH
POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE
MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES
EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING
DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA
ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW
REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND
ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY
DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE
NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS CONTINUE TO BE TRANQUIL ACRS THE AREA HEADING
INTO THIS EVENING. BASED ON THE LATEST GUIDANCE AND RADAR/SAT
TRENDS...EXPECT CONVECTION TO REMAIN WELL NORTH AND EAST OF THE
TERMINAL OVERNIGHT. WINDS WILL BE CALM OR LIGHT SOUTH WITH GENERALLY
THIN CIRRUS OVERHEAD. SOME OF THE GUIDANCE STILL INDICATES IFR CIGS
AND SPOTTY VSBY/FOG RESTRICTIONS. HOWEVER...GIVEN NO RAIN FELL
TODAY...AND PERIODS OF HIGH CLOUDS...WILL REMOVE MENTION OF LOW
CLOUDS WITH THE 00Z TAF. ON THURSDAY...THE ATMOSPHERE ACTUALLY LOOKS
LESS UNSTABLE...WITH LACK OF A TRIGGER FOR CONVECTION ONCE AGAIN.
HOWEVER...BY LATE AFTN GUIDANCE DOES SHOW SCATTERED CONVECTION
DEVELOPING ACRS WESTERN NC. SO WILL ADD A PROB30 FOR TSRA STARTING
AROUND 19Z. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW
THURSDAY AFTN.
ELSEWHERE...SIMILAR TO KCLT DISCUSSION ABOVE. GIVEN LACK OF RAIN
TODAY AND WARM OVERNIGHT TEMPS UNDER PERIODS OF CIRRUS CIGS...EXPECT
ONLY PATCHY HZ/BR OVERNIGHT...PRIMARILY AT KAVL AND KHKY.
OTHERWISE...EXPECT VFR CONDITIONS. ON THURSDAY...GUIDANCE ONCE AGAIN
DEVELOPS CONVECTION DURING THE PEAKING HEATING AFTN HOURS.
HOWEVER...THE ATMOSPHERE LOOKS LESS UNSTABLE WITH STILL A LACK OF
TRIGGER LIKE TODAY. WILL ADD PROB30 FOR TSRA FOR NOW. WINDS WILL BE
A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN.
OUTLOOK...A COLD FRONT WILL PUSH THROUGH LATE FRIDAY...BRING WITH IT
THE POTENTIAL FOR AT LEAST SCATTERED CONVECTION. WITH AFTERNOON
CONVECTION WILL FOLLOW POTENTIAL FOR RESTRICTIONS IN THE MORNING.
MUCH IMPROVED CONDITIONS FOR THE WEEKEND AFTER THE FRONT CLEARS THE
AREA.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-18Z
KCLT HIGH 100% HIGH 83% HIGH 83% HIGH 100%
KGSP HIGH 100% HIGH 100% MED 66% HIGH 100%
KAVL HIGH 100% HIGH 100% MED 66% HIGH 100%
KHKY HIGH 100% HIGH 100% MED 66% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% MED 66% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...ARK/TDP
SHORT TERM...PM
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
644 PM CDT WED APR 8 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 346 PM CDT WED APR 8 2015
PERSISTENT LOW CLOUD EVENT EXPECTED TO CONTINUE ACROSS THE AREA
TONIGHT INTO TOMORROW AS LOW LEVEL EASTERLY FLOW REINFORCES STRATUS
ACROSS THE AREA. BAD OF 850 HPA THETA-E ADVECTION IS EXPECTED TO
LIFT NORTH THROUGH THE LATE AFTERNOON INTO THE EVENING HOURS. STILL
SOME QUESTION AS TO HOW CONVECTIVE ANY ACTIVITY MAY GET AS VERY
STEEP LAPSE RATES EXIST FROM 700-300 MB ACROSS THE SOUTHEASTERN CWA.
RAP SOUNDINGS SHOW SMALL WARM NOSE HOLDING...BUT NOT SURE AM READY
TO BUY INTO THAT ENTIRELY SO HAVE HELD ON TO THE MENTION OF THUNDER
THROUGH THE LATE AFTERNOON. WITH STEEP LAPSE RATES AND COLD
ATMOSPHERE...CERTAINLY A GOOD CASE FOR HAIL IF A STORM CAN DEVELOP
FROM THE ELEVATED WARM AIR AND MOISTURE ADVECTION.
ISENTROPIC LIFT CONTINUES THROUGH THE OVERNIGHT THOUGH CONTINUE TO
HAVE OFF AND ON SATURATION ISSUES ALOFT. THEREFORE...AM EXPECTING
LIGHT RAIN OR DRIZZLE THROUGH THE EVENING HOURS...INCREASING AFTER
MIDNIGHT AS THE DEFORMATION BAND APPROACHES FROM THE WEST.
AS THE SURFACE COLD FRONT/INVERTED TROUGH MOVES THROUGH THE
AREA...FLOW TURNS MORE NORTHERLY WITH WARM NOSE ALOFT COOLING.
THERE IS THE POTENTIAL FOR A FEW FLAKES TO MIX IN WITH THE RAIN
TOMORROW DURING THE DAY...ESPECIALLY IN THE HIGHER ELEVATIONS...BUT
WITH THE WARM LAYER NEAR THE SURFACE REMAINING STEADY THROUGH THE
DAY...AM NOT EXPECTING SNOW TO ACCUMULATE. HAVE LOWERED FORECAST
HIGHS ACROSS THE EAST WITH PRECIPITATION LINGERING THROUGH MUCH OF
THE DAY...WHILE SKIES SHOULD BEGIN TO CLEAR OUT IN CENTRAL SOUTH
DAKOTA THROUGH THE AFTERNOON HOURS LEADING TO A LATE DAY RECOVERY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 346 PM CDT WED APR 8 2015
COULD SEE A LITTLE PRECIP LINGERING IN OUR FAR EAST INTO THURSDAY
EVENING...BUT OTHERWISE EXPECT GENERALLY DRY CONDITIONS TO PREVAIL
THROUGH THE MIDDLE RANGE OF THE FORECAST AS MID LEVEL RIDGE MOVES
ACROSS THE NORTHERN PLAINS. AS THE RIDGE AXIS SHIFTS EAST INTO IOWA
AND MINNESOTA LATE SATURDAY/SATURDAY NIGHT...RETURN FLOW OF MOISTURE
AND WEAK ELEVATED INSTABILITY COULD LEAD TO SOME ISOLATED SHOWERS OR
THUNDERSTORMS. THIS CHANCE WILL LINGER IN THE EAST INTO SUNDAY AS
THE MID LEVEL TROUGH AND ASSOCIATED SURFACE FRONT PUSH THROUGH THE
AREA. TEMPERATURES WILL BE ON A WARMING TREND AGAIN...WITH MID 50S
TO MID 60S EXPECTED FOR HIGHS ON FRIDAY...AND UPPER 60S TO MID 70S
BY SATURDAY.
THE MILD AIR WILL STICK AROUND THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...THOUGH WITH THE DIVERGENCE IN MODEL SOLUTIONS BY TUESDAY AND
WEDNESDAY...THERE IS SOME UNCERTAINTY ON JUST HOW WARM TEMPERATURES
WILL BE. OPTED TO STICK FAIRLY CLOSE TO BROAD MODEL BLEND FOR NOW...
WHICH KEEPS HIGHS IN THE MID 60S TO MID 70S AND LOWS IN THE 40S TO
LOWER 50S.
AS FAR AS PRECIP CHANCES...IT CURRENTLY LOOKS LIKE SUNDAY NIGHT TO
MONDAY SHOULD BE FAIRLY DRY AS THE NORTHERN STREAM TROUGH SHIFTS TO
THE EAST...AND WEAK RIDGING DEVELOPS AHEAD OF A SOUTHERN STREAM WAVE
THAT IS FORECAST TO SWING INTO THE PLAINS FROM THE SOUTHERN ROCKIES
MONDAY NIGHT. THIS WILL BRING A BIT MORE UNSETTLED WEATHER TO THE
AREA MONDAY NIGHT/TUESDAY. GREATER UNCERTAINTY REGARDING THE CHANCE
FOR PRECIP TUESDAY NIGHT/WEDNESDAY DUE TO AFOREMENTIONED DIVERGENCE
IN MODEL SOLUTIONS. WITH LOW CONFIDENCE IN ANY ONE SOLUTION...WILL
HANG ON TO SOME LOW 20-30 RANGE POPS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 639 PM CDT WED APR 8 2015
LOOKING AT IFR CONDITIONS THROUGH THE NIGHT WITH SOME PATCHY LIFR
NOT OUT OF THE QUESTION. THIS WILL OCCUR MAINLY ON THE CEILING
SIDE OF THINGS WHILE THE VISIBILITY WILL GENERALLY BE IN THE MVFR
TO OCCASIONAL IFR CATEGORY. FROM ABOUT 7Z THROUGH 12Z PARTS OF
NORTHEAST NEBRASKA...NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA
WILL SEE A WINDOW OF ABOUT TWO HOURS WITH MODERATE TO BRIEFLY
HEAVY RAINFALL ALONG WITH THE THREAT FOR A FEW LIGHTNING STRIKES.
GRADUAL IMPROVEMENT FROM CENTRAL SOUTH DAKOTA TOWARDS INTERSTATE
29 IS EXPECTED AFTER ABOUT 19Z THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...JH
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1048 PM CDT WED APR 8 2015
RETRANSMITTED AFD
.AVIATION...
A WEAKENING LINE OF THUNDERSTORMS TO THE WEST AND NORTHWEST OF THE
DFW METROPLEX IS NOT EXPECTED TO IMPACT THE AIRPORTS.
HOWEVER...THERE IS STILL A POTENTIAL FOR SCATTERED THUNDERSTORM
DEVELOPMENT LATER TONIGHT AND WILL KEEP THE VCTS MENTION IN THE
METROPLEX FROM 09-12Z FOR NOW. THE LIGHT RAIN HAS DISSIPATED
AROUND THE WACO AREA BUT THE ATMOSPHERE IS CONDUCIVE FOR STRONG
AND GUSTY WINDS TO REACH THE SURFACE UNDERNEATH THE DISSIPATING
RAIN. KACT HAS ALREADY RECORDED WIND GUSTS TO 32 KTS AND THE WINDS
IN THE METROPLEX HAVE INCREASED IN THE LAST HOUR OR TWO. WITH THE
THUNDERSTORMS TO THE WEST WEAKENING AS THEY REACH THE I-35
CORRIDOR...ADDITIONAL WIND GUSTS MAY OCCUR EVEN IF THUNDERSTORMS
DO NOT OCCUR. EXPECT SUSTAINED WINDS OF 15-20 KTS WITH GUSTS OF
25-30 KTS THROUGH THE NIGHT...AND OCCASIONAL GUSTS NEAR 35 KTS.
JLDUNN
.../PREVIOUS AVIATION DISCUSSION/...
/ISSUED 652 PM CDT WED APR 8 2015/
/00Z TAFS/
CONCERNS...MVFR CIGS RETURN OVERNIGHT. CHANCE FOR THUNDERSTORMS
OVERNIGHT OR EARLY THURSDAY MORNING. CHANCE FOR THUNDERSTORMS
LATE THURSDAY AFTERNOON WITH A COLD FRONT ARRIVING IN THE EVENING
HOURS.
SOME SHOWERS AND LIGHT RAIN CONTINUE ACROSS THE REGION THIS
EVENING BUT ARE GENERALLY DIMINISHING OR MOVING EAST OF THE TAF
SITES. WILL KEEP A VCSH MENTION AT KACT FOR A FEW HOURS AND THEN
EXPECT AT LEAST A FEW HOURS OF DRY WEATHER BEFORE ADDITIONAL
SHOWERS AND THUNDERSTORMS ARRIVE OVERNIGHT OR EARLY THURSDAY
MORNING. MOSAIC RADAR ACROSS THE STATE SHOWS NUMEROUS SHOWERS AND
THUNDERSTORMS HAVE ALREADY DEVELOPED IN WEST TEXAS IN ASSOCIATION
WITH A SHORTWAVE. THE TAF CURRENTLY BRINGS VCTS INTO THE DFW
METROPLEX FROM 09-12Z BUT THIS TIMING MAY HAVE TO BE BUMPED UP.
BASED ON THE TRACK OF THE SHORTWAVE TO THE NORTHEAST...LEFT ANY
CONVECTION MENTION OUT OF KACT BUT MAY HAVE TO INCLUDE A MENTION
OF THUNDERSTORMS WITH THE NEXT AMENDMENT. THESE STORMS SHOULD
QUICKLY MOVE THROUGH THE AIRPORTS ONLY AFFECTING OPERATIONS FOR
THREE HOURS OR LESS. THEN...THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED AFTER 09/21Z AS A COLD FRONT MOVES INTO THE AREA. THE
STORMS THURSDAY AFTERNOON AND EVENING COULD BE STRONG OR SEVERE
PRODUCING LARGE HAIL AND DAMAGING WINDS.
VFR CONDITIONS ARE EXPECTED THIS EVENING WITH MVFR STRATUS SURGING
NORTH OVERNIGHT. THE STRATUS WILL ARRIVE AT KACT AROUND 06Z AND
THEN THE METROPLEX AROUND 09Z WITH BASES BETWEEN 1-2 KFT. SIMILAR
TO TODAY...CIGS ARE EXPECTED TO LIFT ABOVE 2 KFT BY MIDDAY AND
THEN TO BETWEEN 3-4 KFT BY MID-LATE AFTERNOON.
SOUTH WINDS BETWEEN 10-15 KTS WILL PREVAIL THROUGH THE PERIOD AND
THEN SWITCH TO THE NORTH AS A COLD FRONT ARRIVES THURSDAY
EVENING. THE FRONT IS EXPECTED TO ARRIVE IN THE METROPLEX BETWEEN
10/01-03Z AND KACT BY 10/06Z.
JLDUNN
&&
.UPDATE...
A BIT OF A WEIRD UPDATE TO INCREASE WIND GUSTS FOR TONIGHT.
00Z FWD SOUNDING SHOWED A PROFILE THAT CAN BE VERY FAVORABLE FOR
HEATBURSTS. HEATBURSTS ARE A TYPE OF MICROBURST...BUT USUALLY
OCCUR AT NIGHT AND ARE ACCOMPANIED BY AN INCREASE IN TEMPERATURE...
AN INCREASE IN WIND...FALLING PRESSURE AND FALLING HUMIDITY. WE
DONT REALLY EXPECT ANY WILD THERMOMETER FLUCTUATIONS TONIGHT...BUT
THESE HEATBURSTS LOOK LIKE THEY WILL BE ABLE TO PRODUCE GUSTY
WINDS IN EXCESS OF 40 MPH. WITH A STRONG LOW LEVEL JET OF 40-50
MPH IN PLACE...ESSENTIALLY THE HEATBURSTS HELP TO TRANSPORT THESE
WINDS DOWN TO THE SURFACE. ALREADY A FEW SITES HAVE GUSTED OVER
40 MPH IN THE LAST 2 HOURS WITH SEVERAL OTHERS ABOVE 35 MPH.
HEATBURSTS ARE MOST LIKELY TO OCCUR WHERE RADAR SHOWS SOME LIGHT
REFLECTIVITY ALOFT...AS THE FIRST STEP TO GET A HEATBURST IS TO
START A DOWNDRAFT IN THE MID LEVELS. WITH ALL OF THE WEAK RADAR
ECHOES AND THE POTENTIAL FOR SOME DISSIPATING ELEVATED
THUNDERSTORMS MOVING IN FROM THE WEST LATER TONIGHT...IT IS LIKELY
SEVERAL LOCATIONS MAY EXPERIENCE PERIODS OF GUSTY WINDS OVERNIGHT.
TR.92
&&
.PREV UPDATE...
UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT
CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN WEST
TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY WILL
WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED
ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE
GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG
WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS
OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT
ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE
NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST
LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH.
OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE.
MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO
NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A
SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON.
THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN
THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN
OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED
IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND
SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO
DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO
COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR
SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY
TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE
EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH
THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO
OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE
TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE
HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER
THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND
PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD.
TR.92
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/
A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS
TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS
HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE
LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING
LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE
CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS
STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL
INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR
ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF
PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY
COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS.
CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT.
THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS
DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL
CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE
PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN
APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE
CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH
TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT
EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS
REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY
LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS
SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE
PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR
ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A
TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW
BENEATH A JUICY LLJ.
AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL
FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY
MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND
OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD
SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION
UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL
SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY
PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT
FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS
BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL
STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE
LINE IMPACTS SOUTHERN AND EASTERN ZONES.
THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON
FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE
FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT
INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER
AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR
ACTIVITIES.
THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH
PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF
RICH GULF MOISTURE.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40
WACO, TX 68 82 59 74 61 / 30 50 40 30 50
PARIS, TX 65 79 54 73 55 / 40 60 50 20 30
DENTON, TX 68 82 54 73 56 / 50 40 30 20 40
MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40
DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40
TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40
CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40
TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50
MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
942 PM CDT Wed Apr 8 2015
.DISCUSSION...
Forecast has been updated to remove Severe Thunderstorm Watch 38
from all but Haskell County. Haskell County will be removed after
this line of thunderstorms move through. Expecting wind gusts in
the 40 mph range, but will allow the storms to move through before
cancelling the watch. Have also lowered PoPs across the area
somewhat as the southern end of the line of thunderstorms
continues to decay as it moves east. 20
&&
.PREV DISCUSSION... /ISSUED 736 PM CDT Wed Apr 8 2015/
DISCUSSION...
Have updated forecast products for Severe Thunderstorm Watch 38
in effect for areas generally west of a Haskell/Abilene/Ballinger/
San Angelo line through 1 AM. Gusts over 60 mph and hail up to
the size of quarters are possible with these storms. The line
should start moving into Sterling/Irion Counties between 8 and 830
PM, and into the Nolan/Fisher County area between 830 and 9 PM.
20
PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/
AVIATION...
/00Z TAFS/
Skies have cleared, except for a blanket of mid and upper level
clouds across most of west central Texas. A weakly organized
broken band of thunderstorms is moving toward the west central
Texas area this evening. Have these storms moving across our TAF
sites roughly between 01Z(8PM) and 06Z(1AM). These storms have
brought gusts of over 40 knots to areas to our west. This is
likely due to very dry low layers of the atmosphere, and fast
movement of the storms themselves. Will carry a mention of gusty
winds to 35 knots in TEMPO groups at area sites to account for the
possibility of gusty winds. Based on most recent trends (gusts to
35-40 knots), do not expect these to bring severe strength wind
gusts of 50 knots or great at this time, but this cannot be ruled
out. For the rest of the overnight hours, models have become much
less pessimistic with respect to low clouds after 03Z(10PM)
tonight, so will go with higher, but still MVFR (2500 feet) CIGS
at most sites tonight beginning around 06Z(1AM). Winds will remain
south to southeasterly and gusty through most of the overnight.
Winds will shift to the west tomorrow between 12Z(7AM) and
15Z(10AM). 20
PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/
SHORT TERM...
(Tonight and Tomorrow)
Initial shortwave has worked itself off to the east and has taken
the first round of mainly elevated convection with it. A little more
potent shortwave is approaching for late this afternoon and this
evening. At the surface, a fairly diffuse dryline extends across the
Permian Basin northward into the Panhandle. Much sharper feature to
the north where the high clouds have thinned enough to allow much
better mixing and a more defined dryline.
Morning soundings showed a substantial cap to overcome for surface
based convection, and the abundant high clouds limiting sunshine and
heating has so far not weakened the cap enough. However, as the
shortwave approaches, should see the cap finally weaken enough to
see at least scattered convection develop from the Permian Basin
north into the South Plains, with the activity spreading into West
Central Texas by sunset. How much convection we see is still a
question, with the HRRR showing a fairly extensive area of storms
while the TTU WRF shows quite a bit less. Given the shear and at
least some instability, if storms can develop and get organized,
they certainly have the potential to reach severe levels. And given
a 50 kt low level jet developing during the evening, storms may be
slow to dissipate through the evening and into the early morning
hours.
Pacific front shifts east into West Central Texas on Thursday,
although perhaps not quite clearing the eastern sections by
afternoon. May have enough moisture still in place for a few storms
to redevelop across areas of a Brownwood to Junction line.
LONG TERM...
(Thursday Night through Wednesday)
Rain chances will continue Thursday night over southern sections
of the forecast where the frontal boundary will be located. The
frontal boundary will continue to provide a focus of thunderstorm
activity Friday and into the weekend as low level winds return to
south and southeasterly allowing isentropic upglide across over
the area. The best chance of additional rainfall will be over the
southern half of the area. Winds aloft will become southwesterly
ahead of an upper level low that will move across the northern
Baja Peninsula Saturday night. Periodic disturbances in the flow
aloft will keep the chance of thunderstorms over the area through
Sunday night. Rain chances will decrease over most of the CWA
from west to east on Monday as the Pacific upper low lifts
northeast from extreme western Texas to the Central Plains.
Residual thunderstorms will still be possible over primarily the
southern CWA through Wednesday as a southwestern flow aloft
reestablishes ahead of another upper level low digging southeast
from the Pacific Northwest to the Central Rockies.
Post-frontal afternoon temperatures on Friday will be in the
lower 70s across the forecast area after Friday morning lows in
50s. Given the continuation of rainfall chances and good cloud
cover through the middle of next week, warm-up will be gradual
with upper 70s for Saturday highs, upper 70s and lower 80s on
Sunday and Monday, and lower 80s for highs on Tuesday and
Wednesday. Morning lows will climb back into the upper 50s to the
lower 60s into the middle of next week.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 86 55 73 60 / 40 5 10 20 40
San Angelo 66 87 57 73 61 / 30 10 10 40 40
Junction 66 85 62 75 62 / 30 20 20 40 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
936 PM CDT WED APR 8 2015
.UPDATE... /RAISED POPS...THUNDER CHANCES WRN THIRD/
FAST PACED CONVECTIVE CLUSTER ARRIVING FROM WEST TX IS A
SOUTHWARD EXTENT OF A BROKEN LINE OF CONVECTION THAT EXTENDS NORTH
INTO NW TX. THE SOUTHERN ENHANCEMENTS ARE LIKELY THE PRODUCT OF
FAVORABLE JET DYNAMICS AND STEEPENING MID LEVEL LAPSE RATES. MOST
OF THE HI-RES RUNS SHOWN THE ACTIVITY WEAKENING BEFORE REACHING
THE I-35 CORRIDOR...BUT DO SHOW SOME AREAS OF LIGHT QPF FROM
LIGHT SHOWERS. WILL EXTEND A MENTION OF SPRINKLES INTO SOUTHEAST
COUNTIES AND BEEF UP POPS OVER MAINLY VAL VERDE COUNTY AND TO A
SMALLER EXTENT THE RIO GRANDE PLAINS. OTHERWISE...THE FORECAST
REMAINS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 703 PM CDT WED APR 8 2015/
AVIATION...
THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO
TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO
DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE
FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT
PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO
MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS
WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL
LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT
LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN
ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON
THURSDAY.
PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO
SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON
INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A
FREDERICKSBURG TO LA GRANGE LINE.
FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH
OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND
SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO
NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN
BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS
ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST
CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS
IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS
AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH
CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE
HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS
SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE
REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED
ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM
FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT
SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED
INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB.
WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS
TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE
CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING
SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS
MOSTLY DRY.
FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A
WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE
DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER
MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS
PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID
AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE
CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE
NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL
FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO
SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST
FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS
POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND
WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL
WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT
MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN
IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS
AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE
REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY
AND POCKETS OF HEAVY RAIN OVER THE WEEKEND.
FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE
NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE
UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE
HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL
LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE
RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH
INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE
LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG
TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND
SOUTHERN ZONES.
FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING
SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED
IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH
INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT
LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND
SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A
LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN
SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS.
FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN
LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED
SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN
ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END
OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE
FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 78 69 85 66 77 / 30 20 30 30 50
AUSTIN BERGSTROM INTL AIRPORT 78 68 83 66 77 / 30 20 30 30 50
NEW BRAUNFELS MUNI AIRPORT 81 68 85 67 79 / 20 20 20 10 50
BURNET MUNI AIRPORT 76 66 84 63 74 / 40 30 40 30 50
DEL RIO INTL AIRPORT 78 68 89 69 83 / 50 50 - 20 50
GEORGETOWN MUNI AIRPORT 77 68 84 64 75 / 30 30 40 40 50
HONDO MUNI AIRPORT 82 68 86 68 80 / 30 30 10 10 50
SAN MARCOS MUNI AIRPORT 79 69 84 66 78 / 20 20 20 20 50
LA GRANGE - FAYETTE REGIONAL 82 70 84 69 80 / 20 10 20 20 50
SAN ANTONIO INTL AIRPORT 81 69 85 69 79 / 30 20 10 10 50
STINSON MUNI AIRPORT 82 69 86 69 80 / 20 20 10 10 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
927 PM CDT WED APR 8 2015
.UPDATE...
A BIT OF A WEIRD UPDATE TO INCREASE WIND GUSTS FOR TONIGHT.
00Z FWD SOUNDING SHOWED A PROFILE THAT CAN BE VERY FAVORABLE FOR
HEATBURSTS. HEATBURSTS ARE A TYPE OF MICROBURST...BUT USUALLY
OCCUR AT NIGHT AND ARE ACCOMPANIED BY AN INCREASE IN TEMPERATURE...
AN INCREASE IN WIND...FALLING PRESSURE AND FALLING HUMIDITY. WE
DONT REALLY EXPECT ANY WILD THERMOMETER FLUCTUATIONS TONIGHT...BUT
THESE HEATBURSTS LOOK LIKE THEY WILL BE ABLE TO PRODUCE GUSTY
WINDS IN EXCESS OF 40 MPH. WITH A STRONG LOW LEVEL JET OF 40-50
MPH IN PLACE...ESSENTIALLY THE HEATBURSTS HELP TO TRANSPORT THESE
WINDS DOWN TO THE SURFACE. ALREADY A FEW SITES HAVE GUSTED OVER
40 MPH IN THE LAST 2 HOURS WITH SEVERAL OTHERS ABOVE 35 MPH.
HEATBURSTS ARE MOST LIKELY TO OCCUR WHERE RADAR SHOWS SOME LIGHT
REFLECTIVITY ALOFT...AS THE FIRST STEP TO GET A HEATBURST IS TO
START A DOWNDRAFT IN THE MID LEVELS. WITH ALL OF THE WEAK RADAR
ECHOES AND THE POTENTIAL FOR SOME DISSIPATING ELEVATED
THUNDERSTORMS MOVING IN FROM THE WEST LATER TONIGHT...IT IS LIKELY
SEVERAL LOCATIONS MAY EXPERIENCE PERIODS OF GUSTY WINDS OVERNIGHT.
TR.92
&&
.PREV UPDATE...
UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT
CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN WEST
TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY WILL
WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED
ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE
GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG
WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS
OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT
ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE
NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST
LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH.
OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE.
MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO
NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A
SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON.
THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN
THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN
OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED
IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND
SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO
DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO
COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR
SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY
TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE
EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH
THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO
OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE
TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE
HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER
THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND
PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD.
TR.92
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/
A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS
TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS
HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE
LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING
LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE
CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS
STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL
INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR
ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF
PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY
COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS.
CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT.
THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS
DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL
CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE
PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN
APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE
CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH
TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT
EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS
REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY
LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS
SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE
PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR
ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A
TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW
BENEATH A JUICY LLJ.
AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL
FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY
MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND
OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD
SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION
UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL
SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY
PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT
FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS
BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL
STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE
LINE IMPACTS SOUTHERN AND EASTERN ZONES.
THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON
FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE
FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT
INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER
AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR
ACTIVITIES.
THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH
PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF
RICH GULF MOISTURE.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40
WACO, TX 68 82 59 74 61 / 30 50 40 30 50
PARIS, TX 65 79 54 73 55 / 40 60 50 20 30
DENTON, TX 68 82 54 73 56 / 50 40 30 20 40
MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40
DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40
TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40
CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40
TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50
MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
742 PM CDT WED APR 8 2015
.UPDATE...
UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT
CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN
WEST TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY
WILL WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED
ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE
GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG
WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS
OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT
ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE
NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST
LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH.
OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE.
MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO
NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A
SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON.
THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN
THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN
OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED
IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND
SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO
DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO
COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR
SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY
TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE
EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH
THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO
OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE
TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE
HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER
THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND
PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD.
TR.92
&&
.AVIATION...
/ISSUED 652 PM CDT WED APR 8 2015/
/00Z TAFS/
CONCERNS...MVFR CIGS RETURN OVERNIGHT. CHANCE FOR THUNDERSTORMS
OVERNIGHT OR EARLY THURSDAY MORNING. CHANCE FOR THUNDERSTORMS
LATE THURSDAY AFTERNOON WITH A COLD FRONT ARRIVING IN THE EVENING
HOURS.
SOME SHOWERS AND LIGHT RAIN CONTINUE ACROSS THE REGION THIS
EVENING BUT ARE GENERALLY DIMINISHING OR MOVING EAST OF THE TAF
SITES. WILL KEEP A VCSH MENTION AT KACT FOR A FEW HOURS AND THEN
EXPECT AT LEAST A FEW HOURS OF DRY WEATHER BEFORE ADDITIONAL
SHOWERS AND THUNDERSTORMS ARRIVE OVERNIGHT OR EARLY THURSDAY
MORNING. MOSAIC RADAR ACROSS THE STATE SHOWS NUMEROUS SHOWERS AND
THUNDERSTORMS HAVE ALREADY DEVELOPED IN WEST TEXAS IN ASSOCIATION
WITH A SHORTWAVE. THE TAF CURRENTLY BRINGS VCTS INTO THE DFW
METROPLEX FROM 09-12Z BUT THIS TIMING MAY HAVE TO BE BUMPED UP.
BASED ON THE TRACK OF THE SHORTWAVE TO THE NORTHEAST...LEFT ANY
CONVECTION MENTION OUT OF KACT BUT MAY HAVE TO INCLUDE A MENTION
OF THUNDERSTORMS WITH THE NEXT AMENDMENT. THESE STORMS SHOULD
QUICKLY MOVE THROUGH THE AIRPORTS ONLY AFFECTING OPERATIONS FOR
THREE HOURS OR LESS. THEN...THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED AFTER 09/21Z AS A COLD FRONT MOVES INTO THE AREA. THE
STORMS THURSDAY AFTERNOON AND EVENING COULD BE STRONG OR SEVERE
PRODUCING LARGE HAIL AND DAMAGING WINDS.
VFR CONDITIONS ARE EXPECTED THIS EVENING WITH MVFR STRATUS SURGING
NORTH OVERNIGHT. THE STRATUS WILL ARRIVE AT KACT AROUND 06Z AND
THEN THE METROPLEX AROUND 09Z WITH BASES BETWEEN 1-2 KFT. SIMILAR
TO TODAY...CIGS ARE EXPECTED TO LIFT ABOVE 2 KFT BY MIDDAY AND
THEN TO BETWEEN 3-4 KFT BY MID-LATE AFTERNOON.
SOUTH WINDS BETWEEN 10-15 KTS WILL PREVAIL THROUGH THE PERIOD AND
THEN SWITCH TO THE NORTH AS A COLD FRONT ARRIVES THURSDAY
EVENING. THE FRONT IS EXPECTED TO ARRIVE IN THE METROPLEX BETWEEN
10/01-03Z AND KACT BY 10/06Z.
JLDUNN
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/
A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS
TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS
HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE
LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING
LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE
CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS
STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL
INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR
ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF
PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY
COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS.
CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT.
THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS
DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL
CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE
PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN
APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE
CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH
TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT
EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS
REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY
LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS
SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE
PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR
ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A
TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW
BENEATH A JUICY LLJ.
AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL
FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY
MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND
OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD
SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION
UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL
SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY
PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT
FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS
BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL
STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE
LINE IMPACTS SOUTHERN AND EASTERN ZONES.
THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON
FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE
FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT
INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER
AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR
ACTIVITIES.
THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH
PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF
RICH GULF MOISTURE.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40
WACO, TX 68 82 59 74 61 / 30 50 40 30 50
PARIS, TX 65 79 54 73 55 / 40 60 50 20 30
DENTON, TX 68 82 54 73 56 / 50 40 30 20 40
MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40
DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40
TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40
CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40
TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50
MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
736 PM CDT Wed Apr 8 2015
.DISCUSSION...
Have updated forecast products for Severe Thunderstorm Watch 38
in effect for areas generally west of a Haskell/Abilene/Ballinger/
San Angelo line through 1 AM. Gusts over 60 mph and hail up to
the size of quarters are possible with these storms. The line
should start moving into Sterling/Irion Counties between 8 and 830
PM, and into the Nolan/Fisher County area between 830 and 9 PM.
20
&&
.PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/
AVIATION...
/00Z TAFS/
Skies have cleared, except for a blanket of mid and upper level
clouds across most of west central Texas. A weakly organized
broken band of thunderstorms is moving toward the west central
Texas area this evening. Have these storms moving across our TAF
sites roughly between 01Z(8PM) and 06Z(1AM). These storms have
brought gusts of over 40 knots to areas to our west. This is
likely due to very dry low layers of the atmosphere, and fast
movement of the storms themselves. Will carry a mention of gusty
winds to 35 knots in TEMPO groups at area sites to account for the
possibility of gusty winds. Based on most recent trends (gusts to
35-40 knots), do not expect these to bring severe strength wind
gusts of 50 knots or great at this time, but this cannot be ruled
out. For the rest of the overnight hours, models have become much
less pessimistic with respect to low clouds after 03Z(10PM)
tonight, so will go with higher, but still MVFR (2500 feet) CIGS
at most sites tonight beginning around 06Z(1AM). Winds will remain
south to southeasterly and gusty through most of the overnight.
Winds will shift to the west tomorrow between 12Z(7AM) and
15Z(10AM). 20
PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/
SHORT TERM...
(Tonight and Tomorrow)
Initial shortwave has worked itself off to the east and has taken
the first round of mainly elevated convection with it. A little more
potent shortwave is approaching for late this afternoon and this
evening. At the surface, a fairly diffuse dryline extends across the
Permian Basin northward into the Panhandle. Much sharper feature to
the north where the high clouds have thinned enough to allow much
better mixing and a more defined dryline.
Morning soundings showed a substantial cap to overcome for surface
based convection, and the abundant high clouds limiting sunshine and
heating has so far not weakened the cap enough. However, as the
shortwave approaches, should see the cap finally weaken enough to
see at least scattered convection develop from the Permian Basin
north into the South Plains, with the activity spreading into West
Central Texas by sunset. How much convection we see is still a
question, with the HRRR showing a fairly extensive area of storms
while the TTU WRF shows quite a bit less. Given the shear and at
least some instability, if storms can develop and get organized,
they certainly have the potential to reach severe levels. And given
a 50 kt low level jet developing during the evening, storms may be
slow to dissipate through the evening and into the early morning
hours.
Pacific front shifts east into West Central Texas on Thursday,
although perhaps not quite clearing the eastern sections by
afternoon. May have enough moisture still in place for a few storms
to redevelop across areas of a Brownwood to Junction line.
LONG TERM...
(Thursday Night through Wednesday)
Rain chances will continue Thursday night over southern sections
of the forecast where the frontal boundary will be located. The
frontal boundary will continue to provide a focus of thunderstorm
activity Friday and into the weekend as low level winds return to
south and southeasterly allowing isentropic upglide across over
the area. The best chance of additional rainfall will be over the
southern half of the area. Winds aloft will become southwesterly
ahead of an upper level low that will move across the northern
Baja Peninsula Saturday night. Periodic disturbances in the flow
aloft will keep the chance of thunderstorms over the area through
Sunday night. Rain chances will decrease over most of the CWA
from west to east on Monday as the Pacific upper low lifts
northeast from extreme western Texas to the Central Plains.
Residual thunderstorms will still be possible over primarily the
southern CWA through Wednesday as a southwestern flow aloft
reestablishes ahead of another upper level low digging southeast
from the Pacific Northwest to the Central Rockies.
Post-frontal afternoon temperatures on Friday will be in the
lower 70s across the forecast area after Friday morning lows in
50s. Given the continuation of rainfall chances and good cloud
cover through the middle of next week, warm-up will be gradual
with upper 70s for Saturday highs, upper 70s and lower 80s on
Sunday and Monday, and lower 80s for highs on Tuesday and
Wednesday. Morning lows will climb back into the upper 50s to the
lower 60s into the middle of next week.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 86 55 73 60 / 60 5 10 20 40
San Angelo 66 87 57 73 61 / 60 10 10 40 40
Junction 66 85 62 75 62 / 40 20 20 40 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
703 PM CDT WED APR 8 2015
.AVIATION...
THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO
TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO
DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE
FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT
PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO
MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS
WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL
LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT
LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN
ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO
SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON
INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A
FREDERICKSBURG TO LA GRANGE LINE.
FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH
OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND
SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO
NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN
BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS
ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST
CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS
IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS
AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH
CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE
HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS
SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE
REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED
ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM
FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT
SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED
INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB.
WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS
TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE
CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING
SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS
MOSTLY DRY.
FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A
WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE
DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER
MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS
PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID
AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE
CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE
NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL
FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO
SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST
FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS
POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND
WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL
WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT
MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN
IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS
AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE
REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY
AND POCKETS OF HEAVY RAIN OVER THE WEEKEND.
FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE
NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE
UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE
HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL
LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE
RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH
INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE
LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG
TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND
SOUTHERN ZONES.
FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING
SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED
IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH
INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT
LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND
SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A
LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN
SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS.
FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN
LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED
SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN
ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END
OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE
FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50
AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50
NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50
BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50
DEL RIO INTL AIRPORT 68 89 69 83 67 / 30 - 20 50 50
GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50
HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50
SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50
LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50
SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50
STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
624 PM CDT Wed Apr 8 2015
.AVIATION...
/00Z TAFS/
Skies have cleared, except for a blanket of mid and upper level
clouds across most of west central Texas. A weakly organized
broken band of thunderstorms is moving toward the west central
Texas area this evening. Have these storms moving across our TAF
sites roughly between 01Z(8PM) and 06Z(1AM). These storms have
brought gusts of over 40 knots to areas to our west. This is
likely due to very dry low layers of the atmosphere, and fast
movement of the storms themselves. Will carry a mention of gusty
winds to 35 knots in TEMPO groups at area sites to account for the
possibility of gusty winds. Based on most recent trends (gusts to
35-40 knots), do not expect these to bring severe strength wind
gusts of 50 knots or great at this time, but this cannot be ruled
out. For the rest of the overnight hours, models have become much
less pessimistic with respect to low clouds after 03Z(10PM)
tonight, so will go with higher, but still MVFR (2500 feet) CIGS
at most sites tonight beginning around 06Z(1AM). Winds will remain
south to southeasterly and gusty through most of the overnight.
Winds will shift to the west tomorrow between 12Z(7AM) and
15Z(10AM). 20
&&
.PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/
SHORT TERM...
(Tonight and Tomorrow)
Initial shortwave has worked itself off to the east and has taken
the first round of mainly elevated convection with it. A little more
potent shortwave is approaching for late this afternoon and this
evening. At the surface, a fairly diffuse dryline extends across the
Permian Basin northward into the Panhandle. Much sharper feature to
the north where the high clouds have thinned enough to allow much
better mixing and a more defined dryline.
Morning soundings showed a substantial cap to overcome for surface
based convection, and the abundant high clouds limiting sunshine and
heating has so far not weakened the cap enough. However, as the
shortwave approaches, should see the cap finally weaken enough to
see at least scattered convection develop from the Permian Basin
north into the South Plains, with the activity spreading into West
Central Texas by sunset. How much convection we see is still a
question, with the HRRR showing a fairly extensive area of storms
while the TTU WRF shows quite a bit less. Given the shear and at
least some instability, if storms can develop and get organized,
they certainly have the potential to reach severe levels. And given
a 50 kt low level jet developing during the evening, storms may be
slow to dissipate through the evening and into the early morning
hours.
Pacific front shifts east into West Central Texas on Thursday,
although perhaps not quite clearing the eastern sections by
afternoon. May have enough moisture still in place for a few storms
to redevelop across areas of a Brownwood to Junction line.
LONG TERM...
(Thursday Night through Wednesday)
Rain chances will continue Thursday night over southern sections
of the forecast where the frontal boundary will be located. The
frontal boundary will continue to provide a focus of thunderstorm
activity Friday and into the weekend as low level winds return to
south and southeasterly allowing isentropic upglide across over
the area. The best chance of additional rainfall will be over the
southern half of the area. Winds aloft will become southwesterly
ahead of an upper level low that will move across the northern
Baja Peninsula Saturday night. Periodic disturbances in the flow
aloft will keep the chance of thunderstorms over the area through
Sunday night. Rain chances will decrease over most of the CWA
from west to east on Monday as the Pacific upper low lifts
northeast from extreme western Texas to the Central Plains.
Residual thunderstorms will still be possible over primarily the
southern CWA through Wednesday as a southwestern flow aloft
reestablishes ahead of another upper level low digging southeast
from the Pacific Northwest to the Central Rockies.
Post-frontal afternoon temperatures on Friday will be in the
lower 70s across the forecast area after Friday morning lows in
50s. Given the continuation of rainfall chances and good cloud
cover through the middle of next week, warm-up will be gradual
with upper 70s for Saturday highs, upper 70s and lower 80s on
Sunday and Monday, and lower 80s for highs on Tuesday and
Wednesday. Morning lows will climb back into the upper 50s to the
lower 60s into the middle of next week.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 86 55 73 60 / 30 5 10 20 40
San Angelo 66 87 57 73 61 / 30 10 10 40 40
Junction 66 85 62 75 62 / 40 20 20 40 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1227 AM CDT TUE APR 7 2015
.AVIATION...
MVFR CIGS HAVE DEVELOPED/SPREAD OVER MUCH OF SOUTH CENTRAL
TEXAS...MOSTLY ALONG THE BALCONES ESCARPMENT AND IN THE HILL
COUNTRY. EXPECT COVERAGE TO EXPAND ACROSS THE EASTERN COASTAL
PLAINS AND WESTERN RIO GRANDE PLAINS OVERNIGHT...AS WELL AS A
LOWERING TO IFR CIGS AT MOST LOCATIONS AFTER 10Z. IFR CIGS WITH
4-6SM BR VSBYS WILL PREVAIL THROUGH 16-17Z TUESDAY. AFTER
THAT...THE FOG SHOULD DISSIPATE QUICKLY AND CIGS LIFT INTO MVFR
AND BEGIN TO THIN...BUT WINDS WILL INCREASE TO 10G20KT OR SLIGHTLY
HIGHER. LOOK FOR VFR SKIES AFTER 19Z...BUT MVFR CIGS WILL RETURN
AROUND 02-04Z...THEN LOWER TO IFR CIGS FOR THE EXTENDED TAFS AT
KAUS AND KSAT.
&&
.PREV DISCUSSION... /ISSUED 934 PM CDT MON APR 6 2015/
UPDATE...
LATE AFTERNOON/EARLY EVENING STORMS OUT OF THE NORTHEAST MEXICAN
MOUNTAINS DISSIPATED AS THEY WERE MOVING EAST AND INTO A CAPPED
REGION. MOST OF THE HIRES AND MEDIUM RANGE GUIDANCE ARE KEEPING
THE AREA DRY OVERNIGHT WITH THE EXCEPTION OF LATEST HRRR AND RAPIP
REFRESH WHICH BRING ISOLATED STORMS ACROSS THE RIO GRANDE PLAINS
OVERNIGHT. AT THIS TIME...WILL GO WITH A DRY FORECAST AFTER
MIDNIGHT AS SUGGESTED BY THE MAJORITY OF THE MODEL SOLUTIONS.
ALSO...ADJUSTED TONIGHT`S TEMPS BASED ON CURRENT TRENDS AND MAV
GUIDANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 83 68 84 69 84 / 10 10 10 10 10
AUSTIN BERGSTROM INTL AIRPORT 82 67 83 68 83 / 10 10 10 10 10
NEW BRAUNFELS MUNI AIRPORT 83 67 85 67 85 / 10 10 10 10 10
BURNET MUNI AIRPORT 82 67 84 66 83 / 10 10 10 10 10
DEL RIO INTL AIRPORT 84 69 87 69 88 / 10 20 10 10 10
GEORGETOWN MUNI AIRPORT 82 68 83 68 83 / 10 10 10 10 10
HONDO MUNI AIRPORT 82 68 84 68 86 / 10 10 10 - 10
SAN MARCOS MUNI AIRPORT 82 67 84 68 83 / 10 10 10 10 10
LA GRANGE - FAYETTE REGIONAL 82 69 84 70 83 / 10 10 10 10 10
SAN ANTONIO INTL AIRPORT 83 68 84 69 84 / 10 10 10 10 10
STINSON MUNI AIRPORT 83 68 84 68 85 / 10 10 10 10 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1139 PM CDT MON APR 6 2015
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
MODELS ARE AGAIN VERY AGGRESSIVE AND TOO QUICK WITH LOWERING CIGS
INTO IFR/MVFR. THE HRRR/NAM AND RAP ARE TOO LOW WITH CIGS AND
INITIALIZED POORLY. PREFER THE GFS FOR THE OVERNIGHT HOURS AND
EVEN THE GFS EVENTUALLY LOWERS CIGS TO UNDER A 1000 FEET BY 12Z
TUES. THERE SHOULD BE A BRIEF WINDOW OF LIFR/IFR CONDS AT ALL TAF
SITES BETWEEN 11-15Z. THE GFS ALSO SCATTERS CLOUDS OUT BY 18Z
WHICH MIGHT BE A TAD FAST. MVFR CIGS EXPECTED TO REDEVELOP LATE
TUESDAY NIGHT. LIGHT TO MODERATE S-SE WINDS ARE EXPECTED THROUGH
THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1015 PM CDT MON APR 6 2015/
UPDATE...
A FEW LIGHT RETURNS SHOWING UP EAST OF THE AREA THIS EVENING
AHEAD OF A DISTURBANCE CROSSING TEXAS FROM MEXICO MAY PRODUCE A
SPRINKLE OR TWO OVER THE FAR NORTHWESTERN FORECAST AREA...
BUT EXPECT TONIGHT TO BE MOSTLY DRY ACROSS THE FORECAST AREA WITH
A RATHER STOUT LAYER OF LOW TO MID LEVEL DRY AIR IN PLACE AND
AIRCRAFT SOUNDINGS OUT OF HOUSTON SHOWING A CAPPING INVERSION
BETWEEN 800-700 MB.
FOR THIS UPDATE... ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURE AND
DEW POINT GRIDS BASED ON LATEST OBSERVATIONS.
HUFFMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 82 68 82 70 / 10 10 10 10 20
HOUSTON (IAH) 68 84 69 83 70 / 10 10 10 10 10
GALVESTON (GLS) 69 77 71 78 71 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
855 PM EDT WED APR 8 2015
.SYNOPSIS...
A BACK DOOR COOL FRONT OVER NORTHEAST VIRGINIA WILL CONTINUE TO EASE
SOUTHWEST ACROSS THE PIEDMONT OVERNIGHT. THE BOUNDARY WILL THEN
LIFT BACK TO THE NORTH THURSDAY AHEAD OF A STRONGER COLD FRONT
APPROACHING FROM THE WEST. THIS FRONT WILL PUSH THROUGH FROM THE
WEST FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 855 PM EDT TUESDAY...
WEDNESDAY AFTERNOON CONVECTION HAS MOVED SOUTHEAST OUT OF THE
FORECAST AREA. A WEAK HIGH PRESSURE CENTER WILL PROVIDE US WITH
A SHORT BREAK IN THE ROUNDS OF CONVECTION THIS EVENING. ANOTHER
AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED IN OHIO AND
KENTUCKY. THIS CONVECTION WILL CONTINUE TO MOVE EASTWARD AND
ROTATE ACROSS OUR REGION TONIGHT INTO THURSDAY MORNING. THE TIMING
OF THIS CONVECTION APPEARS A LITTLE FASTER THAN HIRES MODELS
SUGGEST. THE BETTER INSTABILITY WILL OCCUR UNTIL AROUND 02Z...THEN
THE INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF
STORMS APPROACH. LEANED THE POPS TOWARDS A HRRR AND RAP BLEND
BECAUSE OF THE WARM ADVECTION SHOWERS NOTED ON WSR-88D IMAGES
ACROSS WEST VIRGINIA.
IN ADDITION TO THE SHOWERS AND THUNDERSTORMS...HIGH PRESSURE WILL
CONTINUE TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS
EVENING INTO TONIGHT...AND WILL OVERSPREAD THE MOST OF THE AREA BY
DAWN. RAINFALL FROM THIS EVENING AND TONIGHT STORMS WILL MOISTEN
THE LOW LEVELS OF THE ATMOSPHERE AND CREATE THE LOWER CLOUDS
EXPECTED OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO
THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE
DAY.
INITIALLY SHAPED TEMPERATURES THIS EVENING INTO TONIGHT TOWARDS
LAMP. THEN WITH THE RICH CLOUD COVER...OVERNIGHT TEMPERATURES
WILL REMAIN MILD WITH READINGS FROM THE LOWER 50S IN THE MOUNTAINS
TO THE UPPER 50S IN THE SOUTH. HIGHS ON THURSDAY WILL RANGE FROM
THE UPPER 60S IN THE NORTH TO THE UPPER 70S IN THE SOUTH.
AS OF 600 PM EDT TUESDAY...
MADE SOME ADJUSTMENTS IN POPS AND WEATHER FOR THIS EVENING INTO
TONIGHT...SHAPING TOWARDS WSR-88D RADAR TRENDS AND LATEST HRRR
SOLUTION. ADJUSTED TEMPERATURES FOR THIS EVENING INTO TONIGHT.
AS OF 415 PM EDT TUESDAY...
KEEPING OUR EYES ON A SERIES OF DISTURBANCES STRETCHING FROM
VIRGINIA TO THE MISSISSIPPI RIVER THIS AFTERNOON...ALL TRIGGERING
THUNDERSTORM ACTIVITY AND ALL PROGGED TO RIDE A STATIONARY FRONT
EASTWARD THROUGH THE EVENING AND OVERNIGHT.
THE FIRST LINE OF THUNDERSTORMS IS WEAKENING AS IT ENCOUNTERS THE
DOWNSLOPE FLOW IN THE VICINITY OF INTERSTATE 64. EXPECT LOCALLY
GUSTY WINDS AND POCKETS OF HEAVY RAIN AS THE LINE CROSSES
MOUNTAINS...BUT BELIEVE SEVERE THUNDERSTORM ACTIVITY WILL BE
ISOLATED AT BEST...IF AT ALL. FURTHER WEST...THUNDERSTORM ACTIVITY
DEVELOPING ACROSS CENTRAL KENTUCKY IS EXPECTED TO ENTER OUR MOUNTAIN
EMPIRE COUNTIES AFTER SUNSET...AND CONVECTION DEVELOPING OVER
SOUTHERN ILLINOIS IS EXPECTED TO APPROACH OUR WESTERN RIDGES BEFORE
DAWN THURSDAY. INSTABILITY WILL DECREASE AS THE SECOND AND THIRD
ROUND OF STORMS APPROACH...SO BELIEVE THE THREAT FOR SEVERE STORMS
THIS EVENING AND TONIGHT REMAINS REMOTE.
IN ADDITION TO STORMS...HIGH PRESSURE CONTINUES TO BUILD IN ACROSS
THE PIEDMONT FROM THE NORTHEAST THIS AFTERNOON...AND WILL OVERSPREAD
THE MOST OF THE AREA BY DAWN. BELIEVE THAT RAINFALL ENTERING THE
AREA THIS EVENING AND TONIGHT WILL MOISTEN THE LOW LEVELS OF THE
ATMOSPHERE AND HELP TO STRENGTHEN THE HIGH PRESSURE AS IT BUILDS
IN...WHICH WILL MAKE FOR WIDESPREAD CLOUD COVER OVERNIGHT. HIGH
PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED
INTO PLACE THROUGH MUCH OF THE DAY.
CLOUDS WILL MAINTAIN MILD TEMPERATURES THROUGH THE NIGHT...HOLDING
OVERNIGHT LOWS IN THE MID AND UPPER 50S. WILL STICK TO THE COOL SIDE
OF GUIDANCE FOR HIGH TEMPERATURES ON THURSDAY...HOLDING HIGHS IN THE
LOW AND MID 70S FOR MUCH OF THE AREA. BELIEVE THAT TEMPERATURES WILL
REMAIN COOL THROUGH MID AFTERNOON DUE TO THE MORE WIDESPREAD NATURE
OF THE CLOUD COVER...AND THEN SEE A LATE DAY UPWARD SPIKE IN
TEMPERATURES AS CLOUDS BEGIN TO BREAK UP DURING MAX AFTERNOON
HEATING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
STRONG SHORT WAVE OVER THE UPPER MID WEST WILL MOVE EAST THURSDAY
NIGHT AND FRIDAY. THURSDAY NIGHT THE SURFACE LOW MOVES NORTHEAST
ACROSS THE GREAT LAKES...THEN ON FRIDAY TRACKS INTO SOUTHERN
ONTARIO. ANY REMNANTS OF THE SURFACE WEDGE AND MORE STABLE AIR MASS
IN THE NORTHEAST COUNTY WARNING AREA WILL BE GONE ON THURSDAY
EVENING.
TIMING HAS BEEN CONSISTENT IN THE MODELS BRINGING THE ASSOCIATED
COLD FRONT THROUGH A BULK OF THE COUNTY WARNING AREA ON FRIDAY.
MODELS WERE FORECASTING BEST INSTABILITY AHEAD OF THE FRONT IN THE
PIEDMONT ALONG THE EASTERN EDGE OF THE FORECAST AREA ON FRIDAY
AFTERNOON...WITH CAPES OF AS HIGH AS 2000 J/KG POSSIBLE. WILL
MAINTAIN MENTION OF SEVERE WEATHER THREAT IN THE HAZARDOUS WEATHER
OUTLOOK.
12Z MODELS WERE VERY SIMILAR WITH THE TIMING OF THE FRONT ON FRIDAY.
WILL MAKE SLIGHT ADJUSTMENTS TO THE LOCATION BETWEEN 18Z/2PM FRIDAY
AND 00Z SATURDAY/8PM FRIDAY WITH A HIGHER PROBABILITY OF RAIN. MORE
CHALLENGING TO TELL HOW MUCH COVERAGE OF SHOWERS AND THUNDERSTORMS
THERE WILL BE AHEAD OF THE FRONT THURSDAY NIGHT. HAVE ALSO REMOVED
THE RAIN BEHIND THE FRONT FOR LATE FRIDAY NIGHT AND SATURDAY.
WILL BE TRENDING TOWARD WARMER GUIDANCE AHEAD OF THE FRONT FOR LOWS
ON THURSDAY NIGHT. WILL BE STARTING MILD ON FRIDAY BUT LIMITED
HEATING DURING THE MORNING OVER THE MOUNTAINS WHICH WILL HOLD
TEMPERATURES IN THE 60S. IN THE EAST WHERE THE FRONT COMES THROUGH
LATER...TEMPERATURES WILL RISE WELL INTO THE 70S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...
SECOND PIECE OF ENERGY COMES THROUGH THE NORTHEASTERN TROF ON
SATURDAY SO THE 500 MB LONG WAVE TROF DOES NOT MOVE EAST OF THE
FORECAST AREA UNTIL SUNDAY MORNING. THEN PATTERN RETURNS TO RIDGING
IN THE EAST AND TROFING THE WEST FOR THE REST OF THE PERIOD. HEIGHTS
AT 500 MB BECOME MORE AMPLIFIED BY MONDAY AND TUESDAY. WITH A DEEP
CLOSED LOW IN THE WEST MONDAY THROUGH WEDNESDAY...FORECAST AREA WILL
BE IN BROAD SOUTHWEST FLOW WITH A SERIES OF SHORT WAVES TRACKING OUT
OF THE SOUTHERN PLAINS. AT THE SURFACE A SECONDARY FRONT CROSSES
THE NORTHEAST SATURDAY NIGHT BUT LOOKS FAIRLY WEAK BY THE TIME IT
REACHES THE CENTRAL APPALACHIANS. WPC CONSIDERED NORTH AMERICAN AND
GFS ENSEMBLES AS REASONABLE FOR THE UPPER AND SURFACE TIMING AND
LOCATION OF FEATURES FOR THIS TIME FRAME.
HIGH PRESSURE BUILDS IN FOLLOWING THE FRONT AND WILL BE CENTERED
OVER THE FORECAST AREA ON SUNDAY MORNING. THE HIGH WILL BE OFFSHORE
BY MONDAY AFTERNOON. WARM...MOIST AIR WILL BE IN PLACE ON TUESDAY
AND WEDNESDAY. APPEARS THERE WILL BE NO ORGANIZED LIFTING MECHANISM
TO GENERATE PRECIPITATION BUT ANY DECENT SHORT WAVE SHOULD BE ABLE
TO TRIGGER AT LEAST AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
AFTER TEMPERATURES DROP BEHIND THE FRONT ON FRIDAY...850 MB VALUES
REBOUND MONDAY THROUGH WEDNESDAY. MODELS HOLD RESIDUAL LOW LEVEL
MOISTURE IN THE WESTERN UPSLOPE AREAS THROUGH SATURDAY MORNING.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
AS OF 735 PM EDT WEDNESDAY...
AREAS OF SHOWERS AND THUNDERSTORMS EXITING SOUTHEAST PORTION OF
THE FORECAST AREA THIS EVENING. RAPID UPDATE MODELS INDICATE THAT
CONVECTION DEVELOPING IN THE UNSTABLE AIR ACROSS CENTRAL KENTUCKY
WILL PUSH INTO THE REGION UNTIL AROUND 09/02Z TIMEFRAME.
FINALLY...THE REMNANTS OF THUNDERSTORM ACTIVITY OVER THE
MISSISSIPPI RIVER ARE EXPECTED TO APPROACH THE AREA SHORTLY BEFORE
DAWN ON THURSDAY.
RAINFALL ENTERING THE AREA THIS EVENING AND TONIGHT WILL MOISTEN
AND HELP TO STRENGTHEN THE HIGH PRESSURE WEDGE AS IT CONTINUES TO
OVERSPREAD OUR AREA FROM THE NORTHEAST. MEDIUM CONFIDENCE THAT
IFR CEILINGS AND LOW VISIBILITIES WILL DEVELOP AROUND MIDNIGHT FOR
KROA/KLYH/KDAN AS STRATUS DEVELOPS. WILL ALSO SEE LOW STRATUS
DEVELOP FOR KBCB/KBLF/KLWB AFTER MIDNIGHT...HOWEVER TIMING IS MORE
UNCERTAIN AS IT WILL TAKE LONGER FOR HIGH PRESSURE TO BUILD IN.
HIGH PRESSURE IS EXPECTED TO MAINTAIN ITS HOLD ON THURSDAY...WITH
LOW CEILINGS LINGERING ACROSS MUCH OF THE AREA INTO MID AFTERNOON.
WITH BETTER INSTABILITY ALONG THE CONTINENTAL DIVIDE WHERE HIGH
PRESSURE HAS LESS INFLUENCE...MAY SEE A FEW SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOP BY LATE AFTERNOON IN MAXIMUM HEATING.
EXTENDED AVIATION DISCUSSION...
PROLONGED PERIOD OF MVFR CONDITIONS LOOKS IN ORDER INTO FRIDAY
WITH A COLD FRONTAL PASSAGE EXPECTED LATER FRIDAY. COLD FRONT
EXPECTED TO CLEAR THE REGION FRIDAY NIGHT-SATURDAY MORNING WITH
ANY SHOWERS SUBSIDING...THOUGH SOME UPSLOPE MVFR CEILINGS MAY
LINGER INTO SATURDAY AT KBLF/KLWB. WIDESPREAD VFR THEN RETURNS
SATURDAY NIGHT AND SUNDAY UNDER HIGH PRESSURE BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/KK
NEAR TERM...KK/NF
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...KK/NF/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT WED APR 8 2015
.SHORT TERM...(TONIGHT THRU THU NIGHT)
ISSUED AT 235 PM CDT WED APR 8 2015
MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES/RAIN AMOUNTS
TONIGHT INTO THU NIGHT...SEVERE THREAT IN/NEAR SOUTHWEST WI THU
AFTERNOON...SNOW POTENTIAL THU NIGHT...TEMPERATURES.
18Z DATA ANALYSIS HAD A BROAD AREA OF LOW PRESSURE CENTERED OVER
EASTERN CO WITH A WARM FRONT EASTWARD THRU MO/CENTRAL IL. COOL CAN
HIGH PRESSURE/RIDGING EXTENDED ACROSS LK SUPERIOR TO ND/SOUTHERN
SASKAT. MUCH OF THE UPPER MIDWEST CAUGHT IN THE COOL EASTERLY FLOW
BETWEEN THE HIGH/WARM FRONT...WITH PLENTY OF LOW LEVEL MOISTURE/
CLOUDS STUCK UNDER A RATHER STRONG INVERSION NEAR 850MB HELPING
HOLD DOWN TEMPS AGAIN TODAY. MOST EARLY AFTERNOON TEMPS ACROSS
MN/WI/IA ONLY IN THE MID 30S TO MID 40S. CONVECTION SO FAR TODAY
LIMITED TO THE SOUTH 1/2 OF IA WHERE SOME MOISTURE WAS BEING
PUSHED NORTHWARD OVER THE WARM FRONTAL BOUNDARY.
NO PROBLEMS NOTED WITH 08.12Z MODEL INITIALIZATIONS. MODELS IN GOOD
AGREEMENT AS THE SHORTWAVE ENERGY OVER THE CENTRAL ROCKIES MOVES
INTO THE CENTRAL PLAINS BY 12Z THEN LIFTS TOWARD THE FCST AREA BY
00Z FRI. GOOD CONSENSUS FOR THE WAVE TO QUICKLY MOVE ACROSS/EAST OF
THE FCST AREA THU EVENING WITH SECONDARY NORTHERN STREAM ENERGY TO
DROP INTO THE REGION BEHIND IT LATER THU NIGHT. TREND IS A BIT
FASTER AND WEAKER/MORE OPEN WAVE WITH THE FEATURE AS IT APPROACHES/
PASSES THU/THU NIGHT. GIVEN THE RATHER TIGHT CONSENSUS...SHORT TERM
FCST CONFIDENCE IS GOOD THIS CYCLE.
FOR THE SHORT TERM...LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT AND 850-
700MB MOISTURE TRANSPORT/THETA-E CONVERGENCE QUICKLY INCREASE/
SPREAD NORTHEAST ACROSS THE FCST AREA LATE THIS AFTERNOON/EVENING.
THIS WITH PW VALUES IN THE INFLOW AIRMASS OF 1 TO 1.25 INCHES.
THIS WITH FALLING HGTS AHEAD OF THE SHORTWAVE TROUGH ADVANCING
INTO THE CENTRAL PLAINS AND SOME ELEVATED MUCAPE OF 250-750 J/KG
COMING NORTH WITH THE INFLOW AIRMASS. ALL INDICATIONS ARE
SHRA/TSRA TO SPREAD RATHER QUICKLY NORTH/NORTHEAST ACROSS THE FCST
AREA THIS EVENING AS THE LEAD ROUND OF STRONGER LOW LEVEL FORCING
LIFTS ACROSS THE AREA. TRENDED THE EVENING PRECIP CHANCES TOWARD
80-100 PERCENT FROM SOUTHWEST TO NORTHEAST ACROSS THE FCST AREA
THRU THE EVENING. SFC LOW MOVES INT SOUTHWEST IA/NORTHWEST MO BY
12Z THU WITH THE WARM FRONT AHEAD OF IT JUST SOUTH OF THE WI/IL
BORDER. DEEP LAYERED FORCING/LIFT INCREASE AGAIN LATE TONIGHT AND
FOR THU WITH APPROACH OF THE MID LEVEL SHORTWAVE/TROUGH...WITH A
STRONG FN CONVERGENCE SIGNAL AND DEVELOPMENT/TRANSITION TO A
DEFORMATION BAND OF PRECIP ACROSS THE AREA NORTH OF THE LOW/WARM
FRONT FOR THU INTO THU NIGHT. CAPE POOL IS JUST SOUTH OF THE FCST
AREA THU...WITH SOME OF THIS COMING NORTH INTO THE FCST AREA WITH
THE INFLOW AIR. WILL TREND TOWARD HIGHEST TSRA CHANCES ACROSS THE
CENTRAL/SOUTH PARTS OF THE FCST AREA CLOSE TO THE SFC LOW/CAPE
POOL. WITH 07.12Z NAM HAVING DONE A VERY GOOD JOB WITH PRECIP/QPF
TUE AFTERNOON/EVENING...WILL LEAN TOWARD ITS PRECIP FCST FOR
TONIGHT/THU WITH RAIN AMOUNTS OF 0.75 TO 1.25 INCHES LIKELY
ACROSS MUCH OF THE FCST AREA.
SFC LOW TRACK WILL HAVE AN IMPACT ON THE SVR CHANCES ACROSS THE
SOUTHEAST END OF THE FCST AREA THU AFTERNOON. LATEST MODEL CONSENSUS
IS FURTHER SOUTH WITH THE SFC LOW TRACK...CROSSING THE GRANT CO/IL
BORDER AREA AROUND MID AFTERNOON THU. THIS WOULD EFFECTIVELY KEEP
THE WARM SECTOR AND MUCH OF ANY SVR STORM RISK OUT OF THE FCST AREA.
WILL LEAVE THE SVR RISK FOR THE SOUTHEAST END OF THE FCST FOR THU
AFTERNOON AS IS FOR NOW...SEE SWODY2 FOR MORE DETAILS.
THE LAST MAIN PROBLEM IS POTENTIAL PRECIP TYPE THU NIGHT BEFORE THE
DEFORMATION BAND WEAKENS/MOVES OUT OF THE FCST AREA. MODEL SOUNDINGS
SHOWING STRONG COOLING THE LOWER LEVELS THU EVENING WITH PASSAGE OF
THE 850-500MB TROUGH AXIS...ENOUGH SO FOR PRECIP TO MIX WITH/CHANGE
TO SNOW BEFORE ENDING OVER THE NORTHWEST HALF OF THE FCST AREA. THIS
BEFORE THE DEEPER MOISTURE/ICE IN THE CLOUD TOPS WOULD MOVE OUT.
TOUGH CALL BUT HAVE TO ENTERTAIN THE POSSIBILITY OF SOME WET SNOW
ACCUMULATIONS ON GRASSY AREAS ACROSS SOUTHEAST MN INTO NORTH-CENTRAL
WI THRU THE MID/LATE EVENING HOURS OF THU NIGHT AND ADDED THIS TO
THE FCST GRIDS. USED A BLEND OF THE GUIDANCE LOWS/HIGHS FOR TONIGHT
THRU THU NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 235 PM CDT WED APR 8 2015
MAIN FCST CONCERNS FOR FRIDAY THRU SATURDAY NIGHT...LINGERING -SHRA
UNDER THE COLD POOL/MID LEVEL TROUGH FRI...RETURNING MOISTURE SMALL
SHRA/TSRA CHANCE LATE SAT NIGHT...TEMPERATURES THRU THE PERIOD.
08.12Z MODELS IN GOOD AGREEMENT FOR THE NORTHERN STREAM SHORTWAVE/
TOUGH AXIS TO SWING SOUTHEAST ACROSS THE REGION FRI. TREND IS A BIT
STRONGER WITH THIS FEATURE. GOOD CONSENSUS FOR THIS TROUGH TO EXIT
QUICKLY WITH A SHORTWAVE RIDGE AXIS ALREADY OVER THE REGION BY 18Z
SAT. THIS FEATURE ALSO RATHER TRANSIENT...PUSHED QUICKLY EAST BY
STRONGER SHORTWAVE ENERGY MOVING EAST ALONG THE US/CAN BORDER AND
INTO THE NORTHERN PLAINS BY 12Z SUN. TREND IS FASTER WITH THE US/CAN
BORDER SHORTWAVE AT 12Z SUN. OVERALL FCST CONFIDENCE IN THE FRI THRU
SAT NIGHT PERIOD IS AVERAGE TO GOOD THIS CYCLE.
THIS PERIOD STARTS WITH THE STRONGER SFC-700MB LOW/TROUGH EXITING
QUICKLY EAST. NORTHERN STREAM SHORTWAVE DROPPING IN BRINGS A RATHER
COLD 925-700MB AIRMASS ACROSS THE AREA FRI AFTERNOON. THIS WITH
700MB TEMPS IN THE -8C TO -14C RANGE. MODEL SOUNDINGS SHOWING STEEP
LOW LEVEL LAPSE RATES/MIXING TO 700/650MB DURING THE FRI AFTERNOON
HOURS WITH SOME MOISTURE IN THE 900-850MB LAYER. CHANCE OF -SHRA/-
SHSN FRI MORNING/-SHRA FRI AFTERNOON OVER THE NORTHEAST 1/3 TO 1/2
OF THE FCST AREA LOOKS QUITE REASONABLE. THIS QUICKLY PASSES WITH
RISING HGTS/HIGH PRESSURE RIDGING BUILDING ACROSS THE AREA FRI
NIGHT/SAT. SFC RIDGE AXIS IS NEAR/OVER THE AREA FRI NIGHT. WITH
CLEAR/CLEARING SKIES AND LIGHT WINDS...STRONGER RADIATIONAL COOLING
AND A COLDER NIGHT EXPECTED. SOUTHERLY FLOW/LOW LEVEL WARM ADVECTION
RETURN SAT WITH 925MB TEMPS IN THE +8C TO +12C RANGE BY 00Z SUN AND
MODEL SOUNDINGS SHOWING MIXING TO NEAR 850MB. THESE 925MB TEMPS
SUPPORTING HIGHS ON SAT IN THE UPPER 50S TO MID 60S. LOW LEVEL WARM
ADVECTION CONTINUES SAT NIGHT WITH A SLOW INCREASE OF MOISTURE.
SOUTH GRADIENT WINDS 8-15KTS SAT NIGHT KEEP THE BOUNDARY LAYER
STIRRED/MIXED AND LOWS LOOKING TO BE SOME 12F TO 20F WARMER THAN
THOSE OF FRI NIGHT/SAT MORNING. MAIN AXIS OF MOISTURE TRANSPORT/
INCREASE/WEAK INSTABILITY REMAINS WEST OF THE FCST AREA UNTIL LATER
SAT NIGHT AND LIMITED SMALL -SHRA/-TSRA CHANCE ACROSS THE WEST END
OF THE FCST AREA TO AFTER 06Z SUN. USED A BLEND OF THE MODEL/
ENSEMBLE HIGHS/LOWS FOR FRI THRU SAT NIGHT.
FOR SUN THRU WED...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES MUCH OF THE
PERIOD...ABOVE NORMAL TEMPERATURES.
08.00Z/08.12Z MEDIUM RANGE MODELS IN GOOD AGREEMENT SUN FOR THE
SHORTWAVE RIDGING FROM SAT TO BE FLATTENED/PUSHED EAST OF THE REGION
BY A STRONGER SHORTWAVE MOVING EAST ALONG THE US/CAN BORDER. TREND
IS TOWARD QUASI-ZONAL FLOW ACROSS THE NORTHERN CONUS SUN NIGHT/
MON...AS SHIFT FROM A MORE AMPLIFIED NOAM PATTERN IN THE MAR 06/07
MODEL RUNS. REASONABLE AGREEMENT AMONG MODELS THAT THIS ZONAL FLOW
WILL NOT LAST LONG AS STRONG ENERGY/TROUGHING MOVES INTO THE WESTERN
CONUS...WITH SOUTHWEST FLOW ALOFT OVER MUCH OF THE CENTRAL CONUS BY
LATER TUE AND FOR WED AS DEEP TROUGHING/MID LEVEL LOW DEVELOPS OVER
THE ROCKIES. REASONABLE AGREEMENT FOR A SHORTWAVE AHEAD OF THE MAIN
ROCKIES TROUGH TO LIFT TOWARD/ACROSS THE UPPER MIDWEST TUE/TUE
NIGHT. GIVEN THE REASONABLE CONSISTENCY BETWEEN THE MODELS OUT
TO WED...DAY 4-7 FCST CONFIDENCE IS AVERAGE THIS CYCLE.
LOWER LEVEL WARM/MOISTURE ADVECTION AHEAD OF THE NEXT TROUGH/FRONT
CROSSING THE PLAINS CONTINUES INTO THE UPPER MIDWEST SUN. PW VALUES
IN THE 1+ INCH RANGE AHEAD OF THE TROUGH/FRONT PROGGED TO PUSH
ACROSS THE AREA LATER SUN/SUN EVENING...ALONG WITH MUCAPE IN THE 500-
1000 J/KG RANGE. MODEST 850-700MB FN CONVERGENCE WITH THE TROUGH/
FRONT ALONG WITH SOME LIFT/DIVERGENCE ALOFT AHEAD OF THE
SHORTWAVE. CONSENSUS 25-40 PERCENT SHRA/TSRA CHANCES SUN/SUN NIGHT
APPEAR WELL TRENDED. DRIER CAN/NORTHERN PLAINS HIGH PRESSURE TO
BUILD IN BEHIND THE FRONT FOR MON...WITH MON/MON EVENING NOW
TRENDING DRY. AS STRONGER TROUGHING DIGS INTO THE WESTERN CONUS
MON NIGHT INTO WED... TROUGHING DEVELOPS IN THE CENTRAL PLAINS.
STRENGTHENING SOUTHERLY FLOW AHEAD OF THIS LOW/TROUGH LOOKS TO
QUICKLY RETURN MOISTURE NORTHWARD INTO THE UPPER MIDWEST BY LATER
MON NIGHT AND THRU WED. PW VALUES IN THIS MOISTURE PLUME INTO THE
AREA PROGGED INTO THE 1 TO 1.5 INCH RANGE BY LATER TUE. CAPE
INCREASES INTO THE AREA AS WELL BY LATER TUE INTO WED. DEEPER
LAYERED FORCING/LIFT ACROSS THE REGION AS WELL TUE/WED AHEAD OF
THE SFC LOW/MID LEVEL TROUGHING ADVANCING SLOWLY EAST ACROSS/INTO
THE CENTRAL CONUS. 30-40 PERCENT SHRA/TSRA CHANCES FOR TUE INTO
WED LOOK GOOD AT THIS TIME. 850MB TEMPS PROGGED IN THE +7C TO +11C
MUCH OF THE SUN-WED PERIOD WITH NAEFS SHOWING THIS TO BE 1 TO 1.5
STANDARDIZED ANOMALIES ABOVE NORMAL. WARMER MODEL/ENSEMBLE
CONSENSUS HIGHS IN THE UPPER 50S/60S FOR SUN-WED APPEAR WELL
TRENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1100 PM CDT WED APR 8 2015
CIGS...
NOT A LOT OF CHANGE EXPECTED THROUGH THU NIGHT WITH MOST
CIGS HOVERING AROUND OR BELOW 1 KFT. VARIOUS BOUTS OF SHRA/TS WILL
KEEP CIGS LOWS...AS WILL POOLED MOISTURE UNDER A STRONG LOW LEVEL
INVERSION.
WINDS...
WINDS WILL GO FROM EAST TO NORTH NORTH/NORTHWEST THU
AFTERNOON AS AN AREA OF LOW PRESSURE SLIDES JUST SOUTH OF THE TAF
SITES. INCREASING PRESSURE GRADIENT ON THE NORTHWEST SIDE OF THE LOW
SHOULD RESULT IN AN INCREASE IN SUSTAINED WINDS - ALONG WITH THE
POTENTIAL FOR HIGHER GUSTS - THU NIGHT.
WX/VSBY...
BANDS OF SHOWERS WILL SWEEP ACROSS THE REGION TONIGHT
INTO THU NIGHT. THERE WILL LIKELY BE SEVERAL HOUR BREAKS BETWEEN
THEM...BUT TRYING TO FERRET OUT EXACT TIMING IS PROBLEMATIC...SO
WON/T GET THAT REFINED IN THE FORECAST.
FOR THUNDER CHANCES...BUFKIT SOUNDINGS SHOW MEAGER INSTABILITY A
LOFT...AND INTERESTINGLY MOST OF IT IS ABOVE THE SATURATED LAYER.
THAT SAID...A FEW STORMS HAVE DEVELOPED AND APPROACHED KRST/KLSE.
HAD TO UPDATE PREVIOUS TAFS TO INCLUDE MENTION FOR A FEW HOURS PAST
06Z. RUC GRADUALLY SINKS THE ELEVATED INSTABILITY SOUTHWARD
OVERNIGHT. COULD BE ISOLATED THUNDER THU INTO THU NIGHT...BUT
CONFIDENCE TOO LOW TO INCLUDE IN FORECAST AT THIS TIME.
ALSO OF NOTE IN THE BUFKIT SOUNDINGS IS THE SOMEWHAT SHALLOW NATURE
OF A LOT OF THE SATURATION. IN MANY WAYS ITS MORE SUGGESTIVE OF A
HEAVY DRIZZLE RATHER THAN SHRA/RA TYPE EVENT. HAVE NOTED DRIZZLE
ALREADY THIS EVENING...BEFORE SHOWERS MOVED IN. THU AFTERNOON SEEMS
TO FAVOR DRIZZLE TOO.
VSBYS WILL BE RESTRICTED IN THE HEAVIER PCPN...ESPECIALLY IF HEAVY
DRIZZLE MANIFESTS. SOME FOG SHOULD HELP LOWER VSBYS OVERNIGHT INTO
THU MORNING.
&&
.HYDROLOGY...FOR TONIGHT/THURSDAY
ISSUED AT 235 PM CDT WED APR 8 2015
PORTIONS OF THE FCST AREA RECEIVED 1 TO 2 INCHES OF RAIN LATE
TUE/TUE EVENING. THESE RAINS PRODUCED MINOR WITHIN BANK RISES ON
SOME OF THE RIVERS/STREAMS OF THE AREA. ANOTHER 0.5 TO 1.5 INCHES OF
RAIN ARE EXPECTED TONIGHT INTO THU EVENING. IF THIS RAIN WERE TO
FALL IN AN HOUR...MORE PRONOUNCED RISES MIGHT OCCUR ON SOME RIVERS
AND STREAMS. HOWEVER...THIS RAIN IS EXPECTED TO FALL OVER A 24 TO 36
HR PERIOD. LITTLE MORE THAN ADDITIONAL MINOR WITHIN BANK RISES ARE
ANTICIPATED TONIGHT THRU THU NIGHT...WITH THE DRIER SUB-SOILS
ALLOWING MUCH OF THIS NEEDED MOISTURE TO SOAK INTO THE GROUND.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....RIECK
HYDROLOGY....RRS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
915 PM CDT WED APR 8 2015
.UPDATE...
FORCING WITH INCREASING LOW-LEVEL JET...AND ADDITIONAL FORCING
FOR ASCENT PROVIDED BY 300-250 MB UPPER LEVEL DIVERGENCE...IS
FINALLY ERODING SUBSIDENT LAYER ABOVE 10 K FT ON RAP SOUNDINGS
WITH SCATTERED SHOWERS AND STORMS DEVELOPING IN REGION OF 925-850
MB FRONTOGENESIS FROM SPENCER IA TO JUST SOUTH OF STERLING IL AND
MOVING NE AROUND 30 MPH.
HAVE ADJUSTED POPS/WX TO FOLLOW RADAR TIMING THAT BRINGS SHOWERS
AND SCATTERED ELEVATED STORMS TO SW LAFAYETTE COUNTY AROUND 1030
PM. EXPECT THE BAND OF SHOWERS AND STORMS TO CROSS CWA BETWEEN
1030 PM AND 5 AM. PATCHY DRIZZLE AND FOG WILL PRECEDE THE MAIN
AREA OF SHOWERS.
&&
.AVIATION/06Z TAFS/...COMING SOON
&&
.MARINE...
ALLOWED SMALL CRAFT ADVISORY TO EXPIRE AT 00Z AS WEB CAMS SHOWED
WAVES HAD SUBSIDED BELOW CRITERIA. WEB CAMS ALSO SHOWING FOG IS
GETTING MORE DENSE ALONG THE LAKESHORE WITH NEAR-SHORE OB SITES
BETWEEN 1 1/2 MILES AND 1 3/4 MILES. EASILY 1 MILE OR LESS OVER
THE WATER. WILL ISSUE A MARINE DENSE FOG ADVISORY UNTIL 14Z
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 346 PM CDT WED APR 8 2015/
SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE IS MEDIUM.
LOW CLOUDS WILL LINGER TONIGHT...WITH FOG LINGERING NEAR AND OVER
THE LAKE. FOG HAS BEEN STUBBORN IN THE MILWAUKEE TO KENOSHA
AREA...WITH 1/4 TO 1/2 MILE VISIBILITIES FOR MOST OF THE DAY. THESE
VISIBILITIES SHOULD GRADUALLY CONTINUE TO IMPROVE INTO THE EARLY
EVENING HOURS. WILL KEEP MENTION OF PATCHY DENSE FOG NEAR AND SOUTH
OF MILWAUKEE TONIGHT...WITH PATCHY FOG ELSEWHERE.
SYNOPTIC AND MESOSCALE MODELS CONTINUE TO SHOW ANOTHER ROUND OF
SHOWERS WITH EMBEDDED ELEVATED CONVECTION PUSHING THROUGH THE AREA
TONIGHT INTO THURSDAY MORNING. COULD SEE SMALL HAIL ONCE AGAIN WITH
ANY OF THE STORMS...GIVEN COMBINATION OF ELEVATED CAPE AND EFFECTIVE
LAYER SHEAR. BENEFICIAL RAINFALL INTO THURSDAY MORNING SHOULD BE IN
THE 0.50 TO 0.60 INCH RANGE ACROSS THE AREA.
MODELS STILL IN SOME DISAGREEMENT WITH SURFACE LOW TRACK FOR
THURSDAY AFTERNOON AND EVENING...AND THIS WILL DETERMINE HOW
UNSTABLE THE AREA GETS AND RESULTANT SEVERE WEATHER RISK. THE
CONSENSUS TRACK SEEMS TO BE FROM EAST CENTRAL IOWA TO THE SHEBOYGAN
AREA THURSDAY AFTERNOON AND EVENING. THIS WOULD BRING THE WARM FRONT
AND WARM SECTOR INTO SOUTHEAST AND FAR SOUTH CENTRAL WISCONSIN.
IF THIS OCCURS...AND ENOUGH SUNSHINE DEVELOPS...THERE WOULD LIKELY
BE SEVERE STORM DEVELOPMENT GIVEN THE STRONG DEEP LAYER AND LOW
LEVEL SHEAR VALUES. LARGE HAIL...DAMAGING WINDS AND TORNADOES WOULD
ALL BE POSSIBLE...GIVEN THE PROXIMITY OF THE WARM FRONT AND SURFACE
LOW.
HOWEVER...IF TRACK ENDS UP FURTHER SOUTH...AS IT CAN AND HAS DONE IN
THE PAST THIS TIME OF YEAR...WE WOULD END UP CLOUDY AND SEE ELEVATED
CONVECTION AND A MUCH REDUCED SEVERE RISK. THIS WAS SUPPORTED
SOMEWHAT BY CIPS ANALOGS...WHICH HAD BULK OF SEVERE REPORTS JUST
SOUTH OF THE AREA. THERE WERE STILL SOME SEVERE HAIL/WIND REPORTS IN
THE AREA.
UPDATED DAY 2 OUTLOOK FROM SPC HAS THE FAR SOUTH CENTRAL AND
SOUTHEAST COUNTIES IN SLIGHT TO ENHANCED RISK FOR SEVERE
STORMS...WHICH SEEMS REASONABLE GIVEN THE CONSENSUS SURFACE LOW
TRACK. THIS PERIOD WILL CERTAINLY NEED TO BE WATCHED
CLOSELY...ESPECIALLY THE LOW TRACK AND ANY POSSIBLE CLEARING IN WARM
SECTOR. BROUGHT HIGHS FOR THURSDAY UP IN THE FAR SOUTHEAST...WHICH
HAS BEST SHOT AT GETTING INTO WARM SECTOR AIRMASS.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM
THE THREAT FOR THUNDERSTORMS...SOME OF WHICH MAY BE SEVERE...WILL
QUICKLY DIMINISH AS THE AS THE LOW PRESSURE SYSTEM MOVES OFF TO THE
NORTHEAST AND A COLD FRONT PUSHES THROUGH THE AREA. ALTHOUGH THE
TSRA THREAT WILL BE ENDING THURSDAY NIGHT...EXPECT TO SEE
CONSIDERABLE DEFORMATION ZONE PRECIP ON THE BACK SIDE OF THE
CYCLONE. THE DEFORMATION ZONE...ALONG WITH A 500MB VORT MAX PUSHING
ACROSS CENTRAL WI ON FRIDAY...WILL COMBINE TO KEEP PRECIP IN THE
NE PORTIONS OF OUR CWA THROUGH THE DAY ON FRIDAY.
WHILE A WIDESPREAD PRECIPITATION EVENT SEEMS VERY LIKELY THURSDAY
AND THURSDAY NIGHT...THE GREATEST UNCERTAINTY IN THIS PERIOD IS
WHETHER OR NOT ENOUGH INSTABILITY REACHES SE WI TO ALLOW FOR
SEVERE CONVECTION.
LONG TERM...
SATURDAY...FORECAST CONFIDENCE IS HIGH
RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE
REGION. THE ATMOSPHERE SHOULD DRY OUT BY SATURDAY MORNING...SO
EXPECTING TO SEE MOSTLY CLEAR SKIES AND TEMPS INTO THE MID 60S AWAY
FROM LAKE MI.
SUNDAY...FORECAST CONFIDENCE IS MEDIUM
ANOTHER 500MB SHORTWAVE/VORT MAX WILL PUSH ACROSS THE REGION. AT THE
SURFACE...A TROF/WEAK COLD FRONT TIED TO THE UPPER LEVEL SHORT WAVE
WILL PUSH THOUGH SE WI ON SUNDAY NIGHT AND EARLY MONDAY MORNING.
ALONG WITH THIS SFC TROF...MODELS PUSH A QUICK SLUG OF MOISTURE
THROUGH THE AREA. EXPECT TO SEE RAIN IN THIS PERIOD...AND POSSIBLY
SOME THUNDER IN THE WEST. MODELS IN GOOD AGREEMENT WITH THE TRACK OF
THIS SFC TROF...THOUGH THERE IS STILL SOME UNCERTAINTY CONCERNING
THE TIMING OF THE EVENT. ALL GUIDANCE HAS PRECIP ENDING BY 12Z
MON. THEREFORE HAVE POPS IN THE GRIDS BEGINNING 12Z SUNDAY AND
CONTINUING INTO MONDAY.
MONDAY...FORECAST CONFIDENCE IS MEDIUM
ANOTHER ROUND OF MID-LEVEL RIDGING AND SURFACE HIGH PRESSURE BUILDS
INTO THE REGION AS THE OVERNIGHT PRECIP MOVES OUT OF THE AREA.
DURING THE DAY...ATMOSPHERE LOOKS DRY IN ALL GUIDANCE. SUPERBLEND
INSISTS ON CHANCE POP MONDAY AFTERNOON SO WILL NOT COMPLETELY
REMOVE PRECIP FROM GRIDS...BUT DID ADJUST DOWN TO SLIGHT CHANCE.
TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS LOW
AS A POTENT UPPER LEVEL TROF MOVES EAST ACROSS THE ROCKIES...A
DEEP LOW PRESSURE SYSTEM IN THE SOUTHERN PLAINS WILL MOVE TO THE
NORTHEAST. GUIDANCE SHOWS THE LOW MOVING INTO THE HIGH
PLAINS...THOUGH THERE IS SOME UNCERTAINTY WITH THE TIMING OF THIS
SYSTEM. AS THE LOW MOVES TO THE NORTHEAST...A WARM FRONT SHOULD
PUSH THROUGH WISCONSIN AND BRING US A SHOT AT SOME PRECIPITATION.
THERE IS SOME INSTABILITY WITH THIS SYSTEM...SO WILL BE KEEPING
THUNDER IN THE GRIDS.
AVIATION/00Z TAFS/...
IFR/LIFR CEILINGS SHOULD LINGER TONIGHT INTO THURSDAY MORNING ACROSS
TAF SITES. LIFR VISIBILITIES AT MILWAUKEE SHOULD IMPROVE TO IFR BY
EARLY EVENING. AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS SHOULD
MOVE ACROSS THE REGION FROM MIDDLE EVENING INTO THURSDAY MORNING.
LIFR VISIBILITIES ARE POSSIBLE IN ANY OF THE STORMS...ALONG WITH
SMALL HAIL.
NORTHEAST WINDS WILL BECOME EAST TONIGHT...THEN WILL VARY DEPENDING
ON WHERE WARM FRONT SETS UP THURSDAY. FOR NOW...WENT WITH SOUTH TO
SOUTHWEST WINDS TO THE SOUTH AT TAF SITES FOR THURSDAY. WINDS WOULD
BE NORTHEAST IF THE WARM FRONT AND LOW REMAIN SOUTH OF THE AREA...SO
SOME UNCERTAINTY HERE.
IF LOW AND WARM FRONT MAKE IT INTO SOUTHERN WISCONSIN...THEN
THUNDERSTORMS FROM MIDDLE AFTERNOON THURSDAY TO MIDDLE EVENING
THURSDAY MAY BECOME SEVERE. LARGE HAIL...DAMAGING WINDS AND
TORNADOES ARE ALL POSSIBLE. UNCERTAINTY EXISTS WITH THESE THINGS
OCCURRING...DEPENDING ON IF ENOUGH SUNSHINE DEVELOPS IN THE
AFTERNOON. KEEP UP WITH THE LATEST FORECASTS. WINDS WILL SHIFT WEST
NORTHWEST AND BECOME GUSTY BY LATER THURSDAY NIGHT.
MARINE...
SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN UNTIL 00Z THURSDAY. PERSISTENT NORTHEAST WINDS HELP
REINFORCE THE 3 TO 5 FOOT WAVES ACROSS THE NEARSHORE WATERS UNTIL
THEN. THE WINDS AND WAVES ARE EXPECTED TO WEAKEN SOMEWHAT TONIGHT
INTO THURSDAY...AS LOW PRESSURE MOVES INTO THE REGION.
WINDS SHOULD THEN BECOME GUSTY OUT OF THE WEST NORTHWEST THURSDAY
NIGHT INTO FRIDAY...WITH TIGHT PRESSURE GRADIENT WITH THE PASSING
LOW. SOME GUSTS TO 30 KNOTS ARE POSSIBLE...SO A SMALL CRAFT ADVISORY
MAY BE NEEDED FOR THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD
THURSDAY NIGHT THROUGH WEDNESDAY...BSH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1200 AM CDT TUE APR 7 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 337 PM CDT MON APR 6 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED BROAD UPPER TROUGHING ALONG THE WEST COAST OF THE
U.S....RIDGING ACROSS THE PLAINS AND THEN ZONAL FLOW ACROSS THE
GREAT LAKES AND NEW ENGLAND. A STATIONARY SURFACE FRONTAL ZONE
EXISTS UNDERNEATH THE RIDGING AND ZONAL FLOW NEAR I-80...WITH A MID
LEVEL FRONTOGENESIS AXIS WELL TO THE NORTH ACROSS CENTRAL MN AND
NORTHERN WI. SOME PRECIPITATION WAS FALLING OUT OF THIS AXIS...BUT
A NORTHEAST FLOW OF CANADIAN DRY AIR FROM HIGH PRESSURE IN ONTARIO
HAS DIMINISHED MUCH OF THE PRECIPITATION. THE 12Z GRB SOUNDING AND
ESPECIALLY THE INL SOUNDING SHOWED THAT DRY AIR NICELY. SOME OF THAT
DRY AIR INFILTRATED INTO THE FORECAST AREA THIS MORNING TO CLEAR
SKIES OUT FROM THE STRATUS. HOWEVER...MID AND HIGH CLOUDS WERE
SPREADING BACK OVER THE AREA FROM A BROAD WARM ADVECTION REGIME
UNDER THE UPPER RIDGE...AND THEN SOME LOW STRATUS WAS TRYING TO BACK
INTO THE AREA FROM NORTHEAST WI. A FEW SHOWERS AND STORMS HAVE BEEN
GOING ON NEAR WATERLOO IA MARCHING EAST-NORTHEAST...ASSOCIATED WITH
A WEAK SHORTWAVE INTERACTING WITH THE WARM/MOIST ADVECTION. QUITE
THE LOW LEVEL THERMAL TEMPERATURE GRADIENT EXITS ACROSS THE FORECAST
AREA. PER RAP 925MB TEMPS... READINGS NORTH OF HIGHWAY 29 ARE AROUND
0C COMPARED TO 8C OVER NORTHERN IA AND SOUTHERN WI. FARTHER
SOUTHWEST 20C PLUS 925MB READINGS EXISTS IN WESTERN KS.
THE UPPER RIDGING OVER THE PLAINS IS PROGGED TO PROGRESS OVER THE
FORECAST AREA OVER THE NEXT 24 HOURS IN RESPONSE TO THE TROUGH ALONG
THE WEST COAST MOVING INLAND SLIGHTLY. THIS WILL PUT THE FORECAST
AREA IN A WARM/MOISTURE ADVECTION ZONE ALOFT. ISENTROPIC LIFT FIELDS
SHOW THIS NICELY...ESPECIALLY DURING THE DAY TUESDAY AND EVEN MORESO
IN THE AFTERNOON WEST OF THE MS RIVER ON 290-300K SURFACES.
THUS...WE SHOULD SEE A CONTINUOUS INCREASE AND THICKENING OF CLOUD
COVER. AN EAST TO NORTHEAST LOW LEVEL FLOW BRINGING IN DRIER AIR
FROM ONTARIO WILL HAMPER SOME OF THE PRECIPITATION PRODUCTION...OR
MAKE IT SPOTTY...UNTIL TUESDAY AFTERNOON WHEN PRECIPITABLE WATER
SURGES UP TO 0.75 TO 1 INCH. THEREFORE HIGHEST PRECIPITATION CHANCES
ARE PLACED IN THE LATE TUE AFTERNOON TIME PERIOD.
THE INCREASE IN CLOUD COVER WOULD HELP TO KEEP TEMPERATURES UP.
HOWEVER...THE EASTERLY FLOW OF COOLER DRY AIR IN CONJUNCTION WITH
SPOTTY PRECIPITATION WILL WORK TOGETHER TO KNOCK TEMPERATURES DOWN.
AS SUCH...925MB TEMPS FALL TO -2C NORTH TO +4C SOUTH BY 12Z TUE AND
LINGER NEAR THERE THROUGH MUCH OF TUESDAY. READINGS MAY STRUGGLE TO
CLIMB MUCH ON TUESDAY WITH LIMITED SUNSHINE...AND THE MORE
WIDESPREAD LATE AFTERNOON RAIN NOT HELPING MATTERS.
THE AFOREMENTIONED TEMPERATURES BRING ABOUT PRECIPITATION TYPE
CONCERNS ACROSS TAYLOR/CLARK COUNTY WHERE THE COLDEST AIR EXISTS.
SURFACE TEMPERATURES LOOK TO FALL BACK BELOW FREEZING TONIGHT. FOR
THE EVENING ICE IS SUGGESTED IN THE CLOUDS...SO THERE COULD BE A
RAIN/SNOW MIX. THEN DURING THE OVERNIGHT AND MUCH OF TUESDAY
MORNING...THE ICE IN THE CLOUDS DEPARTS TO THE NORTHEAST...LEAVING
THE POTENTIAL FOR FREEZING RAIN WITH ANY PRECIPITATION.
HOWEVER...ITS POSSIBLE THAT THE LOSS OF ICE MAY END UP ENDING THE
PRECIPITATION ENTIRELY AS SUGGESTED BY THE 06.12Z GFS.
THEREFORE...HAVE NOT ISSUED ANY WINTER WEATHER OR FREEZING RAIN
ADVISORY AT THIS TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 337 PM CDT MON APR 6 2015
THERE ARE TWO MAIN PERIODS OF WEATHER FOCUS...TUESDAY NIGHT AND
LATE WEDNESDAY INTO THURSDAY NIGHT.
A SHORTWAVE TROUGH IS PROGGED TO CROSS MINNESOTA AND WISCONSIN
TUESDAY NIGHT...BRINGING WITH IT A DECENT SURGE OF 850MB MOISTURE
TRANSPORT / ISENTROPIC LIFT. MOISTURE SHOULD BE PLENTIFUL WITH
PRECIPITABLE WATER OF 0.75-1 INCH AND SATURATED SOUNDINGS. THEREFORE
CONDITIONS LOOK FAVORABLE FOR RAIN AND RAISED CHANCES UP TO 80. BEST
JUXTAPOSITION OF LIFT IS SITUATED SOUTH OF I-90 DURING THE EVENING.
ADDITIONALLY...WITH MUCAPE VALUES IN 200-500 J/KG RANGE DURING THE
EVENING ROOTED ABOVE 850MB AND LITTLE CAP...EXPECTING AT LEAST
ISOLATED THUNDERSTORMS TO OCCUR. PRECIPITATION SHOULD DIMINISH WEST
TO EAST AFTER MIDNIGHT AS THE LIFT MOVES OFF TO THE EAST AND
SUBSIDENCE COMES IN. PRECIPITATION TYPE FOR THE MOST PART LOOKS TO
BE RAIN WITH PLENTY OF WARM AIR IN PLACE...EXCEPT FOR TAYLOR COUNTY
SHOULD THE PRECIPITATION GET UP THERE. IN TAYLOR COUNTY...THE AIR
MAY BE COLD ENOUGH TO ALLOW FOR SLEET OR FREEZING RAIN.
A BRIEF BREAK LOOKS TO OCCUR FOR MUCH OF THE DAY WEDNESDAY...UNTIL
THE LATER AFTERNOON HOURS. THIS IS WHEN THE TROUGHING ALONG THE U.S.
WEST COAST BEGINS THE MARCH TOWARDS THE PLAINS...PUSHING ANOTHER
SURGE OF 850MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
FORECAST AREA. PRECIPITABLE WATER ALSO CLIMBS BACK TO 0.75-1 INCH
AFTER FALLING TO NEAR 0.5 INCH DURING THE MORNING. THE SURGE OF
MOISTURE TRANSPORT IS MORE IMPRESSIVE FOR WEDNESDAY NIGHT COMPARED
TO TUESDAY NIGHT...AND IT APPEARS EVERYWHERE SHOULD PICK OF
PRECIPITATION. ANTICIPATING RAIN TO BE THE MAIN PRECIPITATION TYPE
WITH ANY MIXED PRECIPITATION STAYING JUST NORTH OF THE FORECAST
AREA. SHOULD SEE SOME THUNDERSTORMS AGAIN SOUTH OF I-90 AS MUCAPE
ABOVE ANY ELEVATED CAPPING INCREASES TO 200-500 J/KG.
AS WE HEAD INTO THURSDAY...MODELS BEGIN TO SPREAD OUT ON THE SPEED
AND STRENGTH OF THE UPPER TROUGH...IMPACTING THE TRACK OF THE
SURFACE SYSTEM AND WARM SECTOR. THE ECMWF HAS BEEN HOLDING FAIRLY
STEADY WITH A MORE POSITIVE TILT TROUGH AND FARTHER SOUTHEAST
SURFACE LOW. ON THE OTHER HAND...THE 06.12Z GFS/CANADIAN/NAM ARE
MORE NEUTRAL AND EVEN NEGATIVE TILT IN THE NAM...RESULTING IN A
STRONGER SURFACE LOW. HARD TO SAY WHAT SCENARIO WILL PAN OUT...BUT
WITH THE ECMWF ENSEMBLE MEAN SIMILAR TO THE ECMWF...FEEL THE ECMWF
MAY BE MORE LIKELY TO WORK OUT. IN ANY EVENT...PRECIPITATION LOOKS
LIKE A GOOD BET TO CONTINUE ON THURSDAY...BUT OF A LIGHTER VARIETY
AS THE FORCING DIMINISHES TO JUST THE DPVA FROM THE UPPER TROUGH.
TYPE LOOKS TO HOLD AS RAIN. AGAIN THUNDERSTORMS ARE POSSIBLE SOUTH
OF I-90...AND IF THE FARTHER NORTHWEST 06.12Z CANADIAN/GFS PAN OUT
COULD EVEN SEE A SEVERE RISK IN FAR NORTHEAST IA/SOUTHWEST WI.
SOMETHING TO MONITOR. TEMPERATURES EXTREMELY TRICKY FOR THURSDAY AS
THEY DEPEND ON THE LOW TRACK. FOLLOWED A MODEL CONSENSUS FOR NOW.
THURSDAY NIGHT IS DOMINATED BY A COLD CONVEYOR BELT IMPACTING THE
NORTHWEST HALF OF THE FORECAST AREA...WHILE A DRY SLOT ACCOMPANYING
THE UPPER TROUGH TRIES TO MOVE THROUGH THE SOUTHEAST HALF. UNDER THE
COLD CONVEYOR BELT COULD SEE PRECIPITATION MIX WITH OR CHANGE OVER
TO SNOW...ESPECIALLY AS THE NIGHT WEARS ON AS TEMPERATURES COOL.
HOWEVER...BY THE TIME PRECIPITATION BEGINS TO SWITCH OVER...IT COULD
ALSO BE ENDING. THUS...NO SNOW ACCUMULATION IS ANTICIPATED AT THIS
TIME.
STILL KEPT SOME PRECIPITATION CHANCES IN FOR FRIDAY BASED ON A MODEL
CONSENSUS BUT NEW 06.12Z ECMWF/GFS WOULD SUGGEST A DRIER FORECAST
AND OUR FORECAST MAY BE ABLE TO BE DRIED OUT. ALTHOUGH COOL AIR
COMES IN BEHIND THE UPPER TROUGH FOR FRIDAY...POTENTIAL EXISTS FOR
MORE SUN COMPARED TO THURSDAY AND THUS HIGHS FOR MANY LOCATIONS END
UP SIMILAR.
FOR THE WEEKEND INTO EARLY NEXT WEEK. GOOD MODEL AGREEMENT EXISTS
AMONGST THE 06.12Z GFS/ECMWF/CANADIAN FOR UPPER RIDGING TO BUILD
INTO THE AREA FRIDAY NIGHT AND SATURDAY...RESULTING IN DRY
CONDITIONS. FRIDAY NIGHT COULD BE ON THE COOL SIDE WITH SURFACE HIGH
IN PLACE AND CLEARING. MAY EVEN END UP WITH SOME RADIATION FOG.
TEMPERATURES SHOULD REBOUND NICELY ON SATURDAY WITH SUN. THEN ON
SUNDAY AND MONDAY ANOTHER TROUGH THAT FORMS OVER THE WESTERN U.S.
LIFTS INTO/AFFECTS THE REGION. AS A RESULT PRECIPITATION CHANCES
RETURN. TYPE FOR THE MOST PART SHOULD BE RAIN. WARM ADVECTION HELPS
TO PUSH TEMPERATURES TO NEAR OR SLIGHTLY ABOVE SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1155 PM CDT MON APR 6 2015
KEPT TREND OF LOWERING CEILINGS TONIGHT AND OBSERVATIONS SEEM TO
SUPPORT THIS WITH SCT015 SHOWING UP NOW IN WI JUST EAST OF KLSE.
THIS WILL PROGRESS WEST TONIGHT AND BE COMMON BY SUNRISE. WINDS
FROM THE EAST WILL BE GUSTY TUESDAY AND A STRONG WEATHER SYSTEM
MOVES INTO IOWA. SOME INSTABILITY WILL BE PRESENT NEAR THE TAF
SITES BY LATE TUESDAY AS STRONG LIFT COMES INTO THE AREA...WITH
RAIN EXPECTED. DID NOT INCLUDE THUNDER AT THE TAF SITES YET...BUT
FUTURE FORECASTS WILL HAVE TO ASSESS THIS FOR 22Z+ TUESDAY.
ALSO...SOME DRIZZLE MAY BE AROUND THE TAF SITES AFTER 18Z
TUESDAY...BUT DO NOT BELIEVE IT WILL BE A FACTOR TO AVIATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
456 AM MDT TUE APR 7 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 159 AM MDT TUE APR 7 2015
IF YOU ARE AN AFICIONADO OF THE GAMUT OF WEATHER PHENOMENON...YOU
WILL LOVE THE NEXT FEW DAYS.
TODAY...AS EXPECTED BY OUR FORECAST TEAM...LOW CLOUDS AND FOG HAVE
DEVELOPED ALONG AND EAST OF THE LARAMIE RANGE AND INTERSTATE 25
CORRIDOR WITH MOIST LOW LEVEL UPSLOPE. HAVE FOLLOWED THE CURRENT
AREAL FOG COVERAGE AND BOUNDARY LAYER PROGS FOR PAINTING FOG AREAS
THIS MORNING.
FOR THIS AFTERNOON...ATTENTION THEN SHIFTS TO AREAL COVERAGE OF
SHOWERS AND THUNDERSTORMS. DECENT SOUTHWEST FLOW ALOFT WITH WEAK
SHORTWAVE TROUGH MOVING NORTHEASTWARD OVER OUR COUNTIES NEAR PEAK
HEATING...WITH LOW LEVEL EAST SOUTHEASTERLIES ADVECTING LOW LEVEL
MOISTURE TO THE BASE OF THE LARAMIE RANGE. BASED ON THE LOCATIONS OF
THE 850 MB AND 700 MB THETA-E RIDGES...FROM DOUGLAS TO CHEYENNE TO
SIDNEY AND UPWARD VERTICAL MOTION...EXPECT ISOLATED TO SCATTERED
AFTERNOON SHOWERS ALONG THIS THETA-E RIDGE...MOST NUMEROUS FROM
DOUGLAS TO WHEATLAND WHERE UVV AND THETA-E RIDGING IS MOST
COINCIDENT. ENOUGH INSTABILITY FOR A FEW THUNDERSTORMS AS WELL.
TONIGHT...FLOW ALOFT BACKS IN ADVANCE OF THE APPROACHING STRONGER
SHORTWAVE TROUGH...WITH MOIST LOW LEVEL UPSLOPE SOUTHEAST WINDS
CONTINUING TO ADVECT MOISTURE ACROSS OUR EASTERN PLAINS ALONG AND
EAST OF INTERSTATE 25. WILL SEE AN INCREASE IN AREAL COVERAGE OF FOG
ALONG AND EAST OF INTERSTATE 25...AND MAY EVEN SEE SOME AREAS OF
DENSE FOG DEPENDING ON THE AREAL COVERAGE OF LOW CLOUDS AND IF
ISOLATED SHOWERS ARE MINIMIZED.
WEDNESDAY...WOULD NOT BE SURPRISED TO SEE OUR TEAM ISSUE OUR FIRST
SEVERE THUNDERSTORM WARNING OF THE SEASON IN THE AFTERNOON OR
EVENING. IMPRESSIVE AND ROBUST SHORTWAVE TROUGH ALOFT MOVES OVER
CENTRAL WYOMING IN THE AFTERNOON...WITH AN IMPRESSIVE INVERTED
SURFACE TROUGH AXIS ACROSS OUR FAR EASTERN WYOMING COUNTIES. QUITE
PRONOUNCED 850 MB THETA-E RIDGE AXIS EXTENDS ALONG AND JUST WEST OF
THE WYOMING AND NEBRASKA STATE LINE IN THE AFTERNOON...WITH ROARING
LEFT FRONT QUADRANT OF THE 300 MB JET STREAKING IN FROM SOUTHWEST TO
NORTHEAST. ALTHOUGH CAPE WILL NOT BE OVERLY IMPRESSIVE...WITH
PROGGED 500-300 MB AND 700-500 MB QUASIGEOSTROPHIC LIFT...TIMING
COINCIDENT WITH PEAK HEATING...AND SHEAR...WE EXPECT SCATTERED
AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25...WITH A FEW STORMS
BECOMING STRONG TO SEVERE FROM LATE AFTERNOON THROUGH EARLY
EVENING AND THE BEST THREAT FOR STRONGEST THUNDERSTORMS FROM LUSK
TO TORRINGTON TO PINE BLUFFS IN THE AFTERNOON...THEN INTO THE
PANHANDLE IN THE EVENING. WIDESPREAD SHOWERS FOCUSED ALONG THE
INSTABILITY AXIS IN THE AFTERNOON EAST OF INTERSTATE 25.
WEDNESDAY NIGHT...WITH PLENTY OF LOW AND MID LEVEL MOISTURE AS
FUEL...AND THE ENERGIZED PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVING
OVERHEAD...ALONG WITH A POTENT PACIFIC ORIGIN COLD FRONT PASSAGE AND
BAROCLINIC BAND...WILL SEE WIDESPREAD SHOWERS EAST OF I-25 WITH
LESSER COVERAGE WEST OF I-25. PRECIPITATION WILL SWITCH OVER TO SNOW
WITH MINIMAL ACCUMULATIONS AT LOWER ELEVATIONS...THOUGH WE MAY SEE
2 TO 5 INCHES OF SNOW OVER THE SNOWY RANGE AND SIERRA MADRES AND
NORTHERN LARAMIE RANGE. WILL SEE AREAS OF FOG DEVELOP...THOUGH
MINIMIZED BY THE WIDESPREAD SNOW SHOWERS AFTER MIDNIGHT. WINDY AND
CHILLY. TOTAL SNOWFALL OF 3 TO 7 INCHES EXPECTED BY FRIDAY MORNING
OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES.
THURSDAY...AREAL COVERAGE OF SHOWERS WILL WANE IN THE MORNING AND
EARLY AFTERNOON AS THE SHORTWAVE TROUGH ALOFT DYNAMICS MOVE FAR TO
OUR EAST...THOUGH IT WILL BE A WINDY AND COOL EARLY APRIL DAY WITH
MAXIMUM TEMPERATURES IN THE 40S AT LOWER ELEVATIONS AND 30S OVER THE
MOUNTAINS...PER PROGGED LOW AND MID LEVEL GRADIENTS...700 MB
TEMPERATURES AND THICKNESSES.
THURSDAY NIGHT...ANOTHER WEAKER SHORTWAVE TROUGH ALOFT MOVES OVER
WYOMING WITH ONLY WEAK UPWARD VERTICAL MOTION PRODUCING ISOLATED TO
SCATTERED SHOWERS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE
RANGES. DRY ELSEWHERE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 330 AM MDT TUE APR 7 2015
WEAK DEPARTING UPPER LEVEL TROUGH EARLY FRIDAY COULD BRING SOME
ISOLATED SHOWERS TO THE MOUNTAINS THROUGH THE AFTERNOON HOURS.
MOST LOCATIONS THOUGH SHOULD REMAIN DRY. 700MB TEMPERATURES ON THE
REBOUND...CLIMBING TO +4C BY SATURDAY. SHOULD SEE UPPER 60S PRETTY
COMMON SATURDAY IN THE PANHANDLE AND LOW 60S OUT WEST.
GFS AND ECMWF SHOWING A WINDY PERIOD AS 700MB WINDS CONTINUE TO
INCREASE. THIS IN RESPONSE TO A LOW PRESSURE SYSTEM TRACKING
ACROSS THE SOUTHERN CANADIAN PROVINCES SUNDAY INTO MONDAY. IN
FACT...GFS FORECAST 50+KTS AT 700MB MONDAY NIGHT...SO WE COULD BE
LOOKING AT WIND HEADLINES FOR OUR WIND PRONE AREAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 454 AM MDT TUE APR 7 2015
LATEST HRRR GUIDANCE USED FOR THE 12Z TAFS. IFR/LIFR CONDITIONS
FOR MUCH OF THE MORNING. DID STRAY FROM HRRR GUIDANCE ON KCYS A
LITTLE. DO THINK LOW CONDITIONS WILL STAY IN A LITTLE LONGER HERE
AS SOUTH TO SOUTHEAST UPSLOPE WINDS PREVAIL. LOOK FOR A REPEAT OF
STRATUS AND FOG TONIGHT FOR THE NEBRASKA PANHANDLE AND AREAS EAST
OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MDT TUE APR 7 2015
FOR TODAY...SOME CONCERN WEST OF INTERSTATE 25 WHERE
HUMIDITIES IN PORTIONS OF CARBON COUNTY WILL RANGE FROM 15 TO 20
PERCENT IN THE AFTERNOON WITH GUSTY SOUTHWEST WINDS. MINIMAL
CONCERNS ELSEWHERE DUE TO HIGHER HUMIDITIES.
WEDNESDAY...HUMIDITIES WILL BE ABOVE CRITICAL LEVELS...THOUGH FIRE
WEATHER INTERESTS WILL NEED TO WATCH FOR LIGHTNING STRIKES FROM
ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 25.
HUMIDITIES DECREASING AGAIN OVER THE WEEKEND WITH SOME GUSTY WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
333 AM MDT TUE APR 7 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 159 AM MDT TUE APR 7 2015
IF YOU ARE AN AFICIONADO OF THE GAMUT OF WEATHER PHENOMENON...YOU
WILL LOVE THE NEXT FEW DAYS.
TODAY...AS EXPECTED BY OUR FORECAST TEAM...LOW CLOUDS AND FOG HAVE
DEVELOPED ALONG AND EAST OF THE LARAMIE RANGE AND INTERSTATE 25
CORRIDOR WITH MOIST LOW LEVEL UPSLOPE. HAVE FOLLOWED THE CURRENT
AREAL FOG COVERAGE AND BOUNDARY LAYER PROGS FOR PAINTING FOG AREAS
THIS MORNING.
FOR THIS AFTERNOON...ATTENTION THEN SHIFTS TO AREAL COVERAGE OF
SHOWERS AND THUNDERSTORMS. DECENT SOUTHWEST FLOW ALOFT WITH WEAK
SHORTWAVE TROUGH MOVING NORTHEASTWARD OVER OUR COUNTIES NEAR PEAK
HEATING...WITH LOW LEVEL EAST SOUTHEASTERLIES ADVECTING LOW LEVEL
MOISTURE TO THE BASE OF THE LARAMIE RANGE. BASED ON THE LOCATIONS OF
THE 850 MB AND 700 MB THETA-E RIDGES...FROM DOUGLAS TO CHEYENNE TO
SIDNEY AND UPWARD VERTICAL MOTION...EXPECT ISOLATED TO SCATTERED
AFTERNOON SHOWERS ALONG THIS THETA-E RIDGE...MOST NUMEROUS FROM
DOUGLAS TO WHEATLAND WHERE UVV AND THETA-E RIDGING IS MOST
COINCIDENT. ENOUGH INSTABILITY FOR A FEW THUNDERSTORMS AS WELL.
TONIGHT...FLOW ALOFT BACKS IN ADVANCE OF THE APPROACHING STRONGER
SHORTWAVE TROUGH...WITH MOIST LOW LEVEL UPSLOPE SOUTHEAST WINDS
CONTINUING TO ADVECT MOISTURE ACROSS OUR EASTERN PLAINS ALONG AND
EAST OF INTERSTATE 25. WILL SEE AN INCREASE IN AREAL COVERAGE OF FOG
ALONG AND EAST OF INTERSTATE 25...AND MAY EVEN SEE SOME AREAS OF
DENSE FOG DEPENDING ON THE AREAL COVERAGE OF LOW CLOUDS AND IF
ISOLATED SHOWERS ARE MINIMIZED.
WEDNESDAY...WOULD NOT BE SURPRISED TO SEE OUR TEAM ISSUE OUR FIRST
SEVERE THUNDERSTORM WARNING OF THE SEASON IN THE AFTERNOON OR
EVENING. IMPRESSIVE AND ROBUST SHORTWAVE TROUGH ALOFT MOVES OVER
CENTRAL WYOMING IN THE AFTERNOON...WITH AN IMPRESSIVE INVERTED
SURFACE TROUGH AXIS ACROSS OUR FAR EASTERN WYOMING COUNTIES. QUITE
PRONOUNCED 850 MB THETA-E RIDGE AXIS EXTENDS ALONG AND JUST WEST OF
THE WYOMING AND NEBRASKA STATE LINE IN THE AFTERNOON...WITH ROARING
LEFT FRONT QUADRANT OF THE 300 MB JET STREAKING IN FROM SOUTHWEST TO
NORTHEAST. ALTHOUGH CAPE WILL NOT BE OVERLY IMPRESSIVE...WITH
PROGGED 500-300 MB AND 700-500 MB QUASIGEOSTROPHIC LIFT...TIMING
COINCIDENT WITH PEAK HEATING...AND SHEAR...WE EXPECT SCATTERED
AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25...WITH A FEW STORMS
BECOMING STRONG TO SEVERE FROM LATE AFTERNOON THROUGH EARLY
EVENING AND THE BEST THREAT FOR STRONGEST THUNDERSTORMS FROM LUSK
TO TORRINGTON TO PINE BLUFFS IN THE AFTERNOON...THEN INTO THE
PANHANDLE IN THE EVENING. WIDESPREAD SHOWERS FOCUSED ALONG THE
INSTABILITY AXIS IN THE AFTERNOON EAST OF INTERSTATE 25.
WEDNESDAY NIGHT...WITH PLENTY OF LOW AND MID LEVEL MOISTURE AS
FUEL...AND THE ENERGIZED PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVING
OVERHEAD...ALONG WITH A POTENT PACIFIC ORIGIN COLD FRONT PASSAGE AND
BAROCLINIC BAND...WILL SEE WIDESPREAD SHOWERS EAST OF I-25 WITH
LESSER COVERAGE WEST OF I-25. PRECIPITATION WILL SWITCH OVER TO SNOW
WITH MINIMAL ACCUMULATIONS AT LOWER ELEVATIONS...THOUGH WE MAY SEE
2 TO 5 INCHES OF SNOW OVER THE SNOWY RANGE AND SIERRA MADRES AND
NORTHERN LARAMIE RANGE. WILL SEE AREAS OF FOG DEVELOP...THOUGH
MINIMIZED BY THE WIDESPREAD SNOW SHOWERS AFTER MIDNIGHT. WINDY AND
CHILLY. TOTAL SNOWFALL OF 3 TO 7 INCHES EXPECTED BY FRIDAY MORNING
OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES.
THURSDAY...AREAL COVERAGE OF SHOWERS WILL WANE IN THE MORNING AND
EARLY AFTERNOON AS THE SHORTWAVE TROUGH ALOFT DYNAMICS MOVE FAR TO
OUR EAST...THOUGH IT WILL BE A WINDY AND COOL EARLY APRIL DAY WITH
MAXIMUM TEMPERATURES IN THE 40S AT LOWER ELEVATIONS AND 30S OVER THE
MOUNTAINS...PER PROGGED LOW AND MID LEVEL GRADIENTS...700 MB
TEMPERATURES AND THICKNESSES.
THURSDAY NIGHT...ANOTHER WEAKER SHORTWAVE TROUGH ALOFT MOVES OVER
WYOMING WITH ONLY WEAK UPWARD VERTICAL MOTION PRODUCING ISOLATED TO
SCATTERED SHOWERS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE
RANGES. DRY ELSEWHERE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 330 AM MDT TUE APR 7 2015
WEAK DEPARTING UPPER LEVEL TROUGH EARLY FRIDAY COULD BRING SOME
ISOLATED SHOWERS TO THE MOUNTAINS THROUGH THE AFTERNOON HOURS.
MOST LOCATIONS THOUGH SHOULD REMAIN DRY. 700MB TEMPERATURES ON THE
REBOUND...CLIMBING TO +4C BY SATURDAY. SHOULD SEE UPPER 60S PRETTY
COMMON SATURDAY IN THE PANHANDLE AND LOW 60S OUT WEST.
GFS AND ECMWF SHOWING A WINDY PERIOD AS 700MB WINDS CONTINUE TO
INCREASE. THIS IN RESPONSE TO A LOW PRESSURE SYSTEM TRACKING
ACROSS THE SOUTHERN CANADIAN PROVINCES SUNDAY INTO MONDAY. IN
FACT...GFS FORECAST 50+KTS AT 700MB MONDAY NIGHT...SO WE COULD BE
LOOKING AT WIND HEADLINES FOR OUR WIND PRONE AREAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1115 PM MDT MON APR 6 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR STRATUS MOVING
INTO THE PANHANDLE AND INTO THE EXTREME EAST SOUTHEAST WYOMING
WILL PERSIST THROUGH THE OVERNIGHT HOURS. COULD BE A FAIRLY
PROLONGED EVENT. POSSIBLY LASTING IN THE PANHANDLE INTO THE EARLY
AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MDT TUE APR 7 2015
FOR TODAY...SOME CONCERN WEST OF INTERSTATE 25 WHERE
HUMIDITIES IN PORTIONS OF CARBON COUNTY WILL RANGE FROM 15 TO 20
PERCENT IN THE AFTERNOON WITH GUSTY SOUTHWEST WINDS. MINIMAL
CONCERNS ELSEWHERE DUE TO HIGHER HUMIDITIES.
WEDNESDAY...HUMIDITIES WILL BE ABOVE CRITICAL LEVELS...THOUGH FIRE
WEATHER INTERESTS WILL NEED TO WATCH FOR LIGHTNING STRIKES FROM
ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 25.
HUMIDITIES DECREASING AGAIN OVER THE WEEKEND WITH SOME GUSTY WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1118 PM MDT MON APR 6 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 255 PM MDT MON APR 6 2015
TONIGHT:
LATEST WATER VAPOR LOOP WAS SHOWING THE UPPER LEVEL TROF STARTING
TO REACH THE PACIFIC COASTLINE WHILE A 100KT JET CONTINUES TO
NOSE INTO THE BASE OF THIS TROF. ONE INTERESTING NOTE ABOUT THIS
TROF IS THAT THERE IS NOT ANY EVIDENCE OF UPSTREAM ENERGY DIGGING
BEHIND IT BESIDES THE CURRENT JET STREAK. IN ADDITION...THERE IS
NOT A LOT OF JET ENERGY IN THE SOUTHERN STREAM WHICH WILL NOT
FAVOR A DIGGING TROF. AS A RESULT...WE SHOULD SEE THIS TROF
CONTINUE TO SHIFT EAST DURING THE NEXT COUPLE OF DAYS. AHEAD OF
THE TROF...THE SURFACE LEE SIDE TROF WILL BECOME MORE ESTABLISHED
AND START PULLING LOW LEVEL MOISTURE INTO AREAS EAST OF THE
LARAMIE RANGE. WE WILL SEE THE EFFECTS OF THIS LOW LEVEL MOISTURE
LATER TONIGHT IN THE NEBRASKA PANHANDLE WHERE THEY MAY EXPERIENCE
LOW CLOUDS/FOG/LIGHT DRIZZLE. NOT REAL CONFIDENT ABOUT THE DRIZZLE
POTENTIAL SINCE IT APPEARS LIKE THE MOISTURE IS FAIRLY SHALLOW.
HOWEVER...WE COULD SEE THE VISIBILITY DROP TO A 1 MILE IN A FEW
SPOTS.
TUESDAY-TUESDAY NIGHT:
LOW CLOUDS/FOG WILL GRADUALLY SHIFT EAST DURING THE COURSE OF THE
MORNING AS THE BOUNDARY LAYER BEGINS TO MIX OUT. ACROSS THE
WESTERN HALF OF THE AREA...IT WILL CONTINUE TO BE DRY WITH GUSTY
WINDS. HOWEVER...WE MAY START TO SEE SOME ISOLATED CONVECTION
DEVELOP ALONG THE NORTHERN LARAMIE DURING THE EARLY AFTERNOON AS
A JET STREAK MOVES THROUGH THAT REGION AND YIELDS TO SOME UPPER
LEVEL DIFFLUENCE. THIS IS A GOOD SETUP FOR SOME SCATTERED ELEVATED
THUNDERSTORMS WHICH MAY CONTAIN SOME DRY LIGHTNING IN THE NORTHERN
LARAMIE RANGE. WE MAY HAVE TO WATCH THIS POTENTIAL DURING THE
AFTERNOON. THESE THUNDERSTORMS SHOULD PUSH OFF THE MOUNTAINS BY
MID AFTERNOON AND LIFT NORTHEAST BEFORE DISSIPATING EARLY IN THE
EVENING. NOT EXPECTING ANYTHING SEVERE AT THIS TIME DUE TO LIMITED
SHEAR. LOW CLOUDS/FOG WILL ALSO DEVELOP IN AREAS EAST OF THE
LARAMIE RANGE OVERNIGHT DUE TO GOOD UPSLOPE FLOW IN ADVANCE OF THE
UPPER LEVEL TROF.
WEDNESDAY-WEDNESDAY NIGHT:
THE MODELS ARE TRENDING TOWARDS A MUCH MORE PROGRESSIVE SYSTEM
COMPARED TO PREVIOUS RUNS WITH THE SYSTEM REALLY NOT SHOWING ANY
SIGNS OF WRAPPING UP. HOWEVER...THERE IS STILL GOOD POTENTIAL FOR
STRONG/SEVERE THUNDERSTORMS DEVELOPING MAINLY EAST OF THE LARAMIE
RANGE DURING THE AFTERNOON...DUE TO THE JUXTAPOSITION OF THE
SURFACE LEE TROF AND A POTENTIAL VORTICITY ANOMALY MOVING ACROSS.
THESE STORMS COULD EVOLVE INTO A CLUSTER AND SHIFT EAST-SOUTHEAST
DURING THE COURSE OF THE EVENING IN ASSOCIATION WITH THE WAVE. AFTER
THIS CLUSTER MOVES PUSHES EAST...WE WILL SEE THE COLD FRONT START
PLUNGING INTO AREAS EAST OF THE LARAMIE RANGE AND BRING COLDER
TEMPERATURES WITH THE RAIN POSSIBLY CHANGING OVER TO SNOW IN THE
HIGHER ELEVATIONS OF WYOMING. HOWEVER...THIS PRECIPITATION WILL
MOST LIKELY BE SHORT-LIVED DUE TO QUICK FRONTAL FORCING. THE
PANHANDLE STILL LOOKS LIKE IT WILL SEE THE MOST PRECIPITATION IN
THE FORM OF RAINFALL. HOWEVER...THE PINE RIDGE WHERE THEY MAY SEE
SOME SNOW ACCUMULATION WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 255 PM MDT MON APR 6 2015
LONG RANGE MODELS ARE IN POOR AGREEMENT AND ARE STRUGGLING WITH
THE OVERALL PATTERN IN THE EXTENDED. EVEN ON THURSDAY...MODELS
CONTINUE TO STRUGGLE WITH THE EVOLUTION AND POSITION OF THE
PACIFIC STORM SYSTEM PUSHING EASTWARD INTO THE NORTH-CENTRAL GREAT
PLAINS. ALTHOUGH THE GENERAL TREND HAS BEEN MORE PROGRESSIVE AND A
BIT FURTHER NORTH...IT IS STILL UNCLEAR HOW WIDESPREAD THE
PRECIPITATION WILL BE. A FEW MODELS STILL INDICATE RAPID
CYCLOGENESIS OVER EASTERN COLORADO...BUT OTHERS SUCH AS THE NAM
SHOW LITTLE INDICATION OF ANY CYCLOGENESIS EXCEPT MUCH FURTHER
SOUTH. HOWEVER...BECOMING LESS CONFIDENT THAT A MAJOR STORM WILL
IMPACT THE REGION DURING THE MIDDLE OF THE WEEK GIVEN CURRENT
MODEL TRENDS. WILL NEED TO MONITOR THE POSSIBILITY OF PORTIONS OF
THE FORECAST AREA GETTING CLIPPED BY SOME LOCALLY HEAVY
RAIN/SNOWFALL THROUGH EARLY THURSDAY MORNING. OTHERWISE...LOWERED
POP THROUGH THURSDAY EVENING FOR NOW. TEMPERATURES WILL BE BELOW
NORMAL ON THURSDAY AS WELL WITH HIGHS IN THE 30S TO MID 40S.
FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS GENERALLY
SHOW ZONAL FLOW OVER THE AREA WITH A CHANCE OF AFTERNOON SHOWERS
AND ISOLATED THUNDER POSSIBLE. MODEL SOLUTION GREATLY DIVERGE ON
SUNDAY AND MONDAY OF NEXT WEEK...WITH THE GEM AND GFS SHOWING A
STRONG UPPER LEVEL TROUGH PUSHING EASTWARD. THE GFS SHOWS A STRONG
SHORTWAVE LIFTING NORTHEAST AHEAD OF THIS MAIN SYSTEM...WHILE THE
GEM AND ECMWF SHOW THIS SHORTWAVE MUCH FURTHER SOUTH. BY
MONDAY...THE GFS SHOWS THE MAIN UPPER LEVEL TROUGH DIGGING SOUTH
AND STALLING AS THE SOUTHERN SHORTWAVE LIFTS NORTH...FORMING A
DEEP UPPER LEVEL LOW OVER THE DAKOTAS AND EASTERN WYOMING. THE
ECMWF IS MUCH DIFFERENT...SHOWING A CONTINUATION OF NEAR ZONAL
FLOW AS THE MAIN UPPER LEVEL TROUGH LIFTS NORTHEAST BUT IS MUCH
WEAKER COMPARED TO THE GFS. THE FORECAST ENSEMBLES ALSO SHOW ALL
THIS UNCERTAINTY...WITH A WIDE VARIETY OF SOLUTION. IN
ADDITION...SOME ENSEMBLE MEMBERS SHOW THE SOUTHERN SHORTWAVE
PUSHING NORTHWARD...STALLING...AND FORMING A CLOSED LOW OVER
EASTERN COLORADO...WHICH WILL HAVE TO BE MONITORED.
OTHERWISE...DID NOT CHANGE THIS PORTION OF THE FORECAST TOO MUCH
DUE TO ALL THE UNCERTAINTY. HOWEVER...DO EXPECT WARMER
TEMPERATURES ON SATURDAY AND EARLY ON SUNDAY WITH HIGHS IN THE
UPPER 50S TO UPPER 60S...WARMEST ACROSS THE EASTERN PLAINS.
OUTSIDE OF SOME AFTERNOON SHOWERS OR AN ISOLATED TSTORM...IT
SHOULD MAINLY BE DRY ACROSS MOST OF THE FORECAST AREA THIS
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1115 PM MDT MON APR 6 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR STRATUS MOVING
INTO THE PANHANDLE AND INTO THE EXTREME EAST SOUTHEAST WYOMING
WILL PERSIST THROUGH THE OVERNIGHT HOURS. COULD BE A FAIRLY
PROLONGED EVENT. POSSIBLY LASTING IN THE PANHANDLE INTO THE EARLY
AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 255 PM MDT MON APR 6 2015
RED FLAG CONDITIONS WILL PERSIST IN FIRE WEATHER ZONES 302 AND 306
THROUGH THE SUNSET. MEANWHILE...THERE COULD BE A WINDOW FOR MORE
RED FLAG CONDITIONS TOMORROW IN 306 AGAIN FOR LOW HUMIDITIES AND
GUSTY WINDS. HOWEVER...IT LOOKS TO BE RATHER MARGINAL AT THIS TIME
ESPECIALLY WITH CLOUD COVER INCREASING. 302 MAY ALSO SEE THE
POTENTIAL FOR DRY LIGHTNING...BUT WE WILL HOLD OFF ON REISSUING
ANY RED FLAG WARNING FOR THOSE AREAS AND LET THE EVENING/MIDNIGHT
SHIFTS TAKE A CLOSER LOOK. THURSDAY AND FRIDAY WE WILL SEE A BREAK
IN THE RED FLAG CONDITIONS BEFORE NEXT TROF MOVES INTO THE
PICTURE THIS WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
401 AM CDT THU APR 9 2015
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH.
A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE
CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF
DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST
IL CLOSER TO THE VORTICITY MAXIMUM.
SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT
THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT
WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR
THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S
SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA.
SUNDAY... FORECAST CONFIDENCE HIGH.
SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN
ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY...
SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY.
LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH
PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY
SO I LEFT OUT THUNDER.
MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM.
MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO
CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS
ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO
EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS
SYSTEM AND IT WILL NEED TO BE WATCHED.
MRC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SCATTERED THUNDERSTORMS THRU MID MORNING.
* STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING.
* IFR/LIFR THRU MID MORNING.
* EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY
SOUTHWEST THIS AFTERNOON. CMS
//DISCUSSION...UPDATED 06Z...
SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO
LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE.
SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL
SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND
MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT
TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE
POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE
MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH
STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE
AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE
REGARDING TIMING.
IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID
MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY
LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR
FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS
AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING
THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN
SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD.
* MEDIUM FOR WINDS THRU THE PERIOD.
* LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
&&
.MARINE...
333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE
WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER
SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH
WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE
TONIGHT.
WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL
BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH
FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN ARE POSSIBLE.
BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS
EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE...
BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF
NORTHEAST IL. MRC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...NEARSHORE WATERS
UNTIL 10 AM THURSDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
303 AM CDT Thu Apr 9 2015
.SHORT TERM...(Today)
ISSUED AT 303 AM CDT THU APR 9 2015
Latest surface analysis shows the warm front has lifted to the I-74
corridor early this morning with a chaotic wind field across most of
the forecast area. Not sure what the affect the current scattered
convection will have on the position of the frontal boundary thru
the morning hours, but most of the models suggest a continued slow
push to the north as the main surface low tracks northeast to
central Iowa by late this morning. Current thinking is that the cold
front will be positioned just west of the Mississippi River by 21z
with surface based convection developing ahead of the front at that
time as well. Better low level helicity fields supportive of
discrete supercells and possible tornadoes looks to be closer to the
track of the surface low...which by late afternoon is expected to be
in far southwest Wisconsin or northwest Illinois. That would put the
threat for more persistent low level rotating storms just to our
west and north. However, still plenty of shear ahead of the frontal
boundary this afternoon and early this evening to promote damaging
straight line winds as the storms transition into more of a linear
system. Temperature-wise, with the warm front to our north this
afternoon, will continue to go with the warmer guid values most
areas. Latest model data now suggests the backedge of the precip
pushes out of our far southeast counties by midnight, so will extend
the Flash Flood Watch until that time this evening.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 303 AM CDT THU APR 9 2015
Showers and thunderstorms, possibly severe, will be ongoing across
at least the eastern half of the forecast area to start this
evening. Despite the short forecast range, there is still some
spread in the expected cold frontal timing. However, it appears
reasonable that the front will lie somewhere between the Illinois
River and the I-55 corridor by 00Z Friday. Sped up the decrease in
shower/storm chances by mid evening, and I would not be surprised to
see the precipitation chances taper off a few hours earlier,
especially if the squall line gets a head of steam and trends
further ahead of the front than current progs.
Once the front clears the area tonight, quiet conditions, along with
much cooler and less humid air will build across the region into
Sunday. These conditions will be driven by a large area of high
pressure of Canadian origin. While conditions will be notably
cooler/less humid, they will still be at or above normal for early
April.
The next precipitation chances will arrive later Sunday into Sunday
night as a cold front is dragged across the area. While this front
is still expected to stall out at it begins to parallel the
upper-level flow, model trends suggest the front will stall out
further south than previously anticipated. If these trends persist,
Monday and Monday night will end up dry. For now, have reduced but
not eliminated PoPs Monday/Monday night until we see if this recent
model trend sticks.
A slow moving upper-level disturbance will push the front back into
the area by Tuesday, bringing renewed shower/storm chances. The
front and/or upper level disturbances will keep the rain chances
going into the end of the work week. Temperatures should remain at
or above normal through the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1123 PM CDT WED APR 8 2015
A broken line of showers and storms are progressing from SW to NE
across our forecast area. Steady rains will clip CMI over the
first hour of this TAF period, otherwise the other terminals could
see a few hours of dry conditions before showers and storms re-
develop directly over central IL. Elevated instability and
moisture appear sufficient for a continued storm threat through
the night. Localized IFR conditions could develop in any heavy
rains, but mainly expect VFR conditions to drop to MVFR
periodically overnight due to areas of low clouds as well as
precip.
The latest HRRR continues to indicate an expansion of coverage of
showers and storms across our area tonight, which may linger past
sunrise tomorrow before a break develops late morning through mid
afternoon. Timing of any storms at the terminal sites is
difficult, but will keep at least VCTS during the expected
windows of opportunity.
Wind patterns have been variable around storms, with prevailing
direction from the SE. DEC gusted to 41 MPH at 04z/11pm due to
storms. Ambient airflows have seen E-SE winds of 10-15kt, and that
should continue the rest of the night based on the position of the
frontal boundary. Once the storms depart to the east tomorrow
morning, winds will shift to the southwest, and increase to
15-20kt sustained, with gusts to 30kt by afternoon. The next round
of strong to severe storms is projected for Thursday afternoon and
evening, with damaging winds, hail and even a few tornadoes possible
across central IL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through this evening FOR ILZ054>057-061>063-
066>068-071>073.
&&
$$
SHORT TERM...Smith
LONG TERM...Bak
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT THU APR 9 2015
.UPDATE...
IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT
HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD
FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM
FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE
COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD
REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE
ADVISORY IN PLACE.
IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM
ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED
CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS
ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS
OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID-
LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS
LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS
SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM
FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED
TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A
RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL
LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE
DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT
WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL.
KJB
&&
.SHORT TERM...
322 PM CDT
THROUGH THURSDAY NIGHT...
QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER
POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING
TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE
MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING
WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE
MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY.
THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3
PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB
SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR
DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS
JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING
WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES
THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS
IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING
EASTWARD INTO THE OZARK REGION THIS AFTERNOON.
IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL
CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY
MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING.
ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS
EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT
LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND
OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED
LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND
STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND
SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR
AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO
CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE
REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR
STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO
OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR
STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY
WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED
LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH
ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE
THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN
SOUTH OF U.S. HIGHWAY 24.
AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS
OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO
CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION
IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE
FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S
THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS
POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY.
THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS
THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE
STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON
REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY
FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON
PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A
QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM
SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S
CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS
WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY
SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/.
HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS
THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN
OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO
CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY
STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT
LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON
THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE
AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL
FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW-
LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED
CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL
REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON
ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE
REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE.
STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING
WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS.
MTF
&&
.LONG TERM...
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH.
A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE
CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF
DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST
IL CLOSER TO THE VORTICITY MAXIMUM.
SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT
THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT
WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR
THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S
SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA.
SUNDAY... FORECAST CONFIDENCE HIGH.
SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN
ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY...
SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY.
LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH
PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY
SO I LEFT OUT THUNDER.
MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM.
MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO
CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS
ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO
EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS
SYSTEM AND IT WILL NEED TO BE WATCHED.
MRC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SCATTERED THUNDERSTORMS THRU MID MORNING.
* STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING.
* IFR/LIFR THRU MID MORNING.
* EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY
SOUTHWEST THIS AFTERNOON. CMS
//DISCUSSION...UPDATED 06Z...
SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO
LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE.
SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL
SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND
MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT
TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE
POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE
MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH
STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE
AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE
REGARDING TIMING.
IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID
MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY
LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR
FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS
AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING
THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN
SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD.
* MEDIUM FOR WINDS THRU THE PERIOD.
* LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING.
* SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS.
&&
.MARINE...
333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE
WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER
SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH
WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE
TONIGHT.
WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL
BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH
FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN ARE POSSIBLE.
BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS
EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE...
BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF
NORTHEAST IL. MRC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...NEARSHORE WATERS UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 AM EDT THU APR 9 2015
.SYNOPSIS...
ISSUED AT 1003 AM EDT WED APR 8 2015
SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE
OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND
OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT.
SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH
SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD
FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER
ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM
THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S
SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE
50S.
&&
.SHORT TERM...(THIS EVENING AND TONIGHT)
ISSUED AT 400 PM EDT WED APR 8 2015
BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN
PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE
RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED
THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR
AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST
SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT
HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING
INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT
IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR
SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE
OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF
KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER
INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED
AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC
ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE
THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS
REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN
ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS
ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE
WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER
2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM.
BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED
LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST
ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER
ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT
IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING
CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO
PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY
LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED
CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES
GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE
PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT
OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL
DEPICTIONS OF WEAK CVA FORCING.
OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY
RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW
VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO
TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE
CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND
BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE
VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE
ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST
COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF
RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES
EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH
HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR
SOUTHEAST COUNTIES.
&&
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EDT WED APR 8 2015
PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY
NIGHT.
ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY
SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER
IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER
THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE
LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON.
AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER
THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO
SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES
THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE
ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY.
AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT
INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER.
MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES
EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING
FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON.
0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT
PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE
UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE
OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING
HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE
STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH
THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE
LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE
RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY
RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY
RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY.
THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT
OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE
FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE
STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY
EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE
00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR
SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR
A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING
WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1
KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE
BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS
INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS
ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING
CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING.
TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN
EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE
OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE.
AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER
AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL
MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS
TO BUILD INTO THE AREA.
A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN
ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION
CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER
MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY
FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING
THE CWA FRIDAY INTO FRI NIGHT.
ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY
NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM
NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO
HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND
ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME.
AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS
AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE
OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE
THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME
FRAME...MAINLY IN THE 60S AND LOW 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 143 AM EDT THU APR 9 2015
STORMS HAVE BLOWN UP ACROSS NORTHERN ILLINOIS AND NORTHERN INDIANA
AS MOISTURE ADVECTION CONTINUES OVER THE STATIONARY FRONT SETTLED
ACROSS THE AREA. FIRST ROUND OF STORMS HAS LIFTED NORTH OF BOTH
TERMINALS...BUT ANTICIPATE ADDITIONAL STORM DEVELOPMENT OVERNIGHT
AS THE LOW LEVEL JET STRENGTHENS AND ELEVATED INSTABILITY
CONTINUES TO ADVECT INTO THE AREA. SOUTHERLY WINDS WILL STRENGTHEN
THROUGH THE DAY AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST.
ADDITIONAL STORMS EXPECTED AFTER 00Z TOMORROW...BUT WILL WAIT TO
INCLUDE A MENTION UNTIL LATER TAF ISSUANCES WHEN FINER SCALE
DETAILS BECOME MORE APPARENT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...JT
SHORT TERM...AGD
LONG TERM...MCD
AVIATION...BENTLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1133 PM MDT WED APR 8 2015
.UPDATE...
ISSUED AT 922 PM MDT WED APR 8 2015
ISSUED A LARGE UPDATE TO AMEND SKY...WEATHER AND POP GRIDS FOR
THIS EVENING THROUGH TOMORROW EVENING. FOG/STRATUS HAS PUSHED
FARTHER SOUTH THAN MOST GUIDANCE ONCE AGAIN. HRRR AND RUC HAVE
LOCKED ONTO STRATUS WHILE OTHER GUIDANCE PERSISTS WITH A POOR
FORECAST. ALSO...INCREASED POPS TO ACCOUNT FOR SHOWERS...STORMS
AND DRIZZLE TONIGHT AND SHOWERS/DRIZZLE TOMORROW. THE FOG/DRIZZLE
SETUP IS ESSENTIALLY IDENTICAL TO THE PREVIOUS TWO NIGHTS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 153 PM MDT WED APR 8 2015
AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS
TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE
MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM
EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL
MOVE IN BEHIND THE TROUGH THURSDAY.
PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY.
DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS
TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE
OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE
BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING.
DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF
SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA
ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL
BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE
NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH
CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP
THOSE IN THE FORECAST.
BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA
LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT.
VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE
NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY
MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND
SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA.
MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING.
EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX
TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO
THE LOWER 50S TO MID 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 107 PM MDT WED APR 8 2015
SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL
RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT.
TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL.
SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A
CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT.
BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO
2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE
PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE
HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN
BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY
WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN
THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY
DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL.
CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE
SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A
CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT
EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME
NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT
SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES
WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS
FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY
MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE
AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY.
NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN
NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH
TEMPERATURES ABOVE TO MUCH ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1133 PM MDT WED APR 8 2015
LOW CONFIDENCE FORECAST THIS RUN AS GUIDANCE CONTINUES STRUGGLE
WITH FOG/DRIZZLE/STRATUS PLACEMENT. MOST ALL GUIDANCE KEEPS
STRATUS TOO FAR NORTH BUT INITIAL FRONT HAS RETROGRADED FARTHER
SOUTH THAN ANTICIPATED ONCE AGAIN. WENT WITH A PESSIMISTIC
FORECAST SIMILAR TO ONGOING OBSERVATIONS AND WHAT OCCURRED PAST
TWO NIGHTS. VARIABLE CIGS/VIS LIKELY LATER THIS MORNING AS A
STRONGER COLD FRONT PASSES THROUGH...INCREASING ATMOSPHERIC
MIXING. OVERALL...EXPECTING AN IMPROVING TREND FROM LATE MORNING
INTO THE AFTERNOON. NORTH WINDS BACK NORTHEAST BY MORNING AND
INCREASE SIGNIFICANTLY IN SPEED BEHIND THE STRONGER COLD FRONT.
ANTICIPATE GUSTY WINDS THROUGHOUT THE LATE MORNING/AFTERNOON
TODAY. WINDS RELAX UNDER VFR CIGS/VIS BEFORE SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...RRH
SHORT TERM...FS
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
156 AM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 1208 AM EDT THU APR 9 2015
A FEW AREAS ACROSS THE REGION HAVE CLEARED OUT WITH CLOUD COVER
AND WHERE THIS HAS OCCURRED...DENSE FOG IS BEGINNING TO DEVELOP.
FOR NOW HAVE PUT THE MENTION OF FOG INTO THE ZONES AND THE HWO. A
FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE
FORECAST AREA...ESPECIALLY IN THE SOUTH...WHERE INSTABILITY IS
RELATIVELY UNTOUCHED. THIS ACTIVITY MAY CONTINUE INTO THE MORNING
HOURS. IN THE NORTH...DECIDED TO KEEP THE FLOOD WATCH GOING AS A
FEW SHOWERS CONTINUE TO MOVE THE AREA AND ACTIVITY OUT WEST MAY
MAKE IT INTO THE AREA LATER TONIGHT. HAVE UPDATED THE GRIDS AND
SENT THEM TO THE NDFD SERVERS AND HAVE ISSUED SOME FRESH ZONES.
UPDATE ISSUED AT 750 PM EDT WED APR 8 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS
AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN
KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY
RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S
AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH
AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH
THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS
OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING
THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME
TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER
05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE
CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 455 PM EDT WED APR 8 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY
WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS.
SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER
TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS
UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES
MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF
CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN
THE SMALL SCALE FEATURES AT PLAY.
IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS
EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING
CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG
QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY
WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL
CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST
HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING
THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE
NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN
THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN
CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT
CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR
SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z.
HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE
THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES.
THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY
MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH
APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES
FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 521 PM EDT WED APR 8 2015
A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE
PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF
THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING
THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL
THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY.
AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A
WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY
OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD
SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE
MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN
FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE
LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES
ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY
NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS
LONG RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU APR 9 2015
AFTER A ROUND OF SHOWERS AND THUNDERSTORMS MOVED THROUGH PORTIONS
OF EASTERN KY THIS EVENING...CLEARING IS FINALLY STARTING TO TAKE
PLACE. THERE IS SOME CONCERN TONIGHT ABOUT FOG DEVELOPMENT.
GUIDANCE IS SHOWING NO FOG POTENTIAL. HOWEVER...WITH CLEARING
SKIES AND SUCH A MOIST ENVIRONMENT...THE POTENTIAL IS DEFINITELY
THERE...ESPECIALLY IN THE VALLEYS. IT/S JUST A MATTER OF IF THIS
FOG WILL SET IN AT THE TAF SITES...AND IF IT DOES...FOR HOW LONG
AND TO WHAT RESTRICTION. KEPT WITH IFR VIS AFTER 9Z...BUT WILL
CONTINUE TO MONITOR FOG DEVELOPMENT IN CASE CHANGES NEED TO BE
MADE. BY TOMORROW...OUR NEXT ROUND OF INSTABILITY WILL BRING
SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION...ESPECIALLY
DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY
WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT
WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE
WIDESRPEAD CHANCES VERY LATE IN THE PERIOD...AFFECTING
KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044-
050>052-104.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JVM/GREIF
LONG TERM...HAL
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1247 AM EDT Thu Apr 9 2015
...Updated Aviation Discussion...
...Mesoscale Forecast Update...
Issued at 830 PM EDT Wed Apr 8 2015
Strong to marginally severe convection across southern Indiana and
much of central Kentucky is now pushing into the Bluegrass region.
One renegade supercell near Owensboro weakened rapidly as it pushed
eastward within the last hour, suggesting that our environment has
been worked over, and observed temperatures are now in the upper 60s
across most of the area. Warmer temps in south central Kentucky, but
the environment is capped and the dynamical forcing aloft is also
lacking.
Will cut back on POPs as these storms exit the Bluegrass over the
next hour or so, and work on canceling the Tornado Watch. The Flash
Flood Watch is in effect and will be left in place, even though the
flood threat won`t ramp up again until we get the next round of
convection in sometime Thursday.
.SHORT TERM (Now through Thursday Night)...
Issued at 308 PM EDT Wed Apr 8 2015
...More Strong Storms Possible This Evening and Tomorrow...
Multiple boundaries have set up across the region this afternoon.
SPC mesoanalysis shows all the CIN from earlier in the day has
eroded and we have become moderately unstable with 2500-3500 J/kg CAPE.
A Severe Thunderstorm Watch has been issued for southern Indiana for
this afternoon and early evening. However, given the multiple
boundaries and possibility for strong storms elsewhere around the
forecast area, extensions to the Watch are not out of the question
this afternoon. Large hail and damaging winds will be the main
threats this afternoon, though a tornado or two cannot be ruled out
completely. The other concern for tonight will be the possibility of
training thunderstorms, particularly across southern IN and north
central KY. The latest runs of the HRRR have been suggesting this.
Given that flash flood values are under an inch an hour and storms
may train in this area, have gone ahead and issued a Flash Flood
Watch starting late this afternoon and continuing through tomorrow
night.
There should be a relative lull in the storms for much of the
overnight period as any storms that develop this afternoon will move
out late this evening. Think another complex associated with a weak
upper level wave will move in early tomorrow morning and continue
through the morning hours. Some small hail and gusty winds will be
possible with these storms.
There should be at least a short break in storm coverage tomorrow
afternoon ahead of the more significant chance for severe weather
along and ahead of the cold front tomorrow night. Moisture will pool
ahead of the front with strong southerly winds through the afternoon
tomorrow. Forcing will come from the upper level trough moving in
and an upper level jet. Shear will increase and hodographs exhibit
favorable clockwise curving tomorrow night. A broken line of showers
and thunderstorms looks to develop to our west congeal into a line
as it moves into the forecast area tomorrow evening. Damaging winds
will be the the main threat with the squall line, with a few
embedded tornadoes possible. If any cells do develop ahead of the
main line hail could be a threat as well.
Due to the repeated areas of convection moving across the region,
have kept the Flash Flood Watch in place through tomorrow night.
Repeated rains will only exacerbate or renew flooding problems.
.LONG TERM (Friday through Wednesday)...
Issued at 241 PM EDT Wed Apr 8 2015
Not much has changed in the thinking for the long term period. Due
to the ongoing storms an updated discussion will not be issued this
afternoon. The previous discussion is below.
Previous discussion
-------------------
Cold front should pass through the area during the pre-dawn hours
Friday in our west then sweep across the rest of central Kentucky
during the early morning hours. Westerly flow will bring in a drier
and quieter pattern Friday night.
Plan on a pleasant, sunny and seasonable Saturday with high pressure
over the lower Ohio Valley. Sunday will start off in similar fashion
but as the high quickly moves to the east, southerly return flow
will begin to push another slug of warm, moist air to the region.
Shower chances return Sunday night through Monday as a trough digs
across the central Plains. High-end chance to likely POPs look
reasonable early next week with near normal temperatures.
&&
.AVIATION (06Z TAF Update)...
Updated at 1245 AM EDT Thu Apr 9 2015
Plan on VFR conditions the remainder of the overnight as air mass
across central Kentucky has been worked over by earlier convection
and is largely stable. A complex of showers/storms currently across
Illinois may try to dip southeastward toward SDF/LEX by 11-13z.
Confidence isn`t high as meso-models are showing this could end up
staying to the north. Will keep mention in the TAFs for now.
Increasing pressure gradient ahead of the next system will result in
strong southerly winds later today at all sites. Plan on sustained
winds 15-20 kts with gusts 25 to locally 30 kts. Timing the new few
waves of convection is tricky but it looks like a pre-frontal system
could spark a round of thunderstorms late this afternoon through
early evening (22-03z) then a brief break before the main cold front
passes 06-09z Friday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH through late tonight FOR KYZ023>025-028>043-
045>049-053>057-066-067.
IN...FLASH FLOOD WATCH through late tonight FOR INZ076>079-083-084-
089>092.
&&
$$
Mesoscale.........RAS
Short Term........EER
Long Term.........BJS
Aviation..........ZT
AREA FORECAST DISCUSSION
NWS JACKSON KY
1208 AM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 1208 AM EDT THU APR 9 2015
A FEW AREAS ACROSS THE REGION HAVE CLEARED OUT WITH CLOUD COVER
AND WHERE THIS HAS OCCURRED...DENSE FOG IS BEGINNING TO DEVELOP.
FOR NOW HAVE PUT THE MENTION OF FOG INTO THE ZONES AND THE HWO. A
FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE
FORECAST AREA...ESPECIALLY IN THE SOUTH...WHERE INSTABILITY IS
RELATIVELY UNTOUCHED. THIS ACTIVITY MAY CONTINUE INTO THE MORNING
HOURS. IN THE NORTH...DECIDED TO KEEP THE FLOOD WATCH GOING AS A
FEW SHOWERS CONTINUE TO MOVE THE AREA AND ACTIVITY OUT WEST MAY
MAKE IT INTO THE AREA LATER TONIGHT. HAVE UPDATED THE GRIDS AND
SENT THEM TO THE NDFD SERVERS AND HAVE ISSUED SOME FRESH ZONES.
UPDATE ISSUED AT 750 PM EDT WED APR 8 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS
AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN
KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY
RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S
AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH
AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH
THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS
OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING
THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME
TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER
05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE
CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 455 PM EDT WED APR 8 2015
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY
WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS.
SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER
TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS
UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES
MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF
CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN
THE SMALL SCALE FEATURES AT PLAY.
IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS
EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING
CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG
QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY
WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL
CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST
HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING
THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE
NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN
THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN
CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT
CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR
SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z.
HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE
THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES.
THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY
MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH
APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES
FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 521 PM EDT WED APR 8 2015
A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE
PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF
THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING
THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL
THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY.
AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A
WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY
OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD
SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE
MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN
FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE
LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES
ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY
NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS
LONG RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 750 PM EDT WED APR 8 2015
AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH NORTHERN
KENTUCKY THIS EVENING. EXPECT A FEW INSTANCES OF MVFR
CONDITIONS...MAINLY IN AND AROUND THE HEAVY THUNDERSTORMS. THIS
ACTIVITY WILL MOVE OFF TOP THE EAST BY 05Z AND SKIES WILL BEGIN TO
CLEAR A BIT AS CLOUD COVER ASSOCIATED WITH THE ACTIVITY
DISSIPATES. WITH THIS...MAY SEE A FEW AREAS OF FOG LATE TONIGHT
AND HAVE PUT THIS INTO THE TAF SITES. CONDITIONS SHOULD BEGIN TO
IMPROVE AFTER DAWN BEFORE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS DEVELOP LATE THURSDAY AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044-
050>052-104.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JVM/GREIF
LONG TERM...HAL
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
423 AM EDT THU APR 9 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE
TO WEAKEN TODAY...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM
FRONT THIS AFTERNOON INTO TONIGHT. ANOTHER COLD FRONT CROSSES THE
REGION LATE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS FEATURES COLD FRONT IN PLACE SOUTH OF THE LOCAL
AREA THIS MORNING. CONTINUE TO NOTE SOME VERY LIGHT RAIN/DZ AND
FOG ACROSS FAR NORTHERN ZONES, WITH MORE WIDESPREAD AREA OF SHOWERS
AND EMBEDDED TSTMS CURRENTLY PUSHING SLOWLY TO THE E-SE FROM THE
PIEDMONT INTO CENTRAL VA FOLLOWING WEAK STEERING FLOW JUST NORTH
OF THE FRONTAL ZONE. HAVE CONTINUED TO NOTE ELEVATED INSTABILITY
IN THIS AREA ATOP A STABLE/SATURATED BL. THE HRRR HAS HANDLED
THIS (AND PREVIOUS) ROUND OF CONVECTION QUITE WELL AND HAVE HEDGED
THE FORECAST IN ITS DIRECTION FOR THE FIRST PART OF THE NEAR TERM.
WILL TAKE CURRENT SWATH OF CONVECTION ACROSS CENTRAL ZONES THROUGH
08-09Z...BEFORE IT TRANSITIONS ACROSS SE VA AND OFFSHORE BY 15Z.
WITH PW VALUES WELL ABOVE CLIMO AVG (~2SD), SOME BRIEF HEAVY
DOWNPOURS REMAIN POSSIBLE THIS MORNING. OTHERWISE, AS WITH
YESTERDAY, GIVEN STABLE BL AND LITTLE IF ANY TANGIBLE IMMINENT
FORCING MECHANISM UPSTREAM, WILL GO WITH A RELATIVE LULL IN PCPN
AND A MAINLY DRY ALBEIT MAINLY OVERCAST AFTERNOON. GIVEN MOIST
AIRMASS, WILL STICK WITH A SLIGHT CHC OF SHRAS FOR THE AFTN. LOOK
FOR HIGHS IN THE MID TO UPPER 50S ACROSS THE NORTH, LOW TO MID 60S
CENTRAL ZONES, AND U60S TO MID 70S ALONG AND SOUTH OF US 58
CORRIDOR OF SOUTHERN VA/INTERIOR NE NC.
LOW PRESSURE OVER THE PLAINS WILL TRACK NE INTO THE UPPER MIDWEST
LATE TODAY INTO EARLY FRIDAY. RESULTANT DEVELOPING WEAK RIDGING
ALLOWS SW FLOW TO DEVELOP, WHICH WILL SHUNT WEAK FRONTAL ZONE
BACK NORTH BY LATE IN THE DAY. WHILE MOST OF THE AREA WILL REMAIN
IN THE STABLE/EASTERLY FLOW TODAY, EXPECT MILDER TEMPERATURES BY
AFTN ACROSS SOUTHERN TIER OF THE CWA AS FRONT BEGINS TO LIFT BACK
NORTH LATE TDA/TNGT. CONTINUED MILD ACROSS THE SOUTH TONIGHT, WITH
LOWS IN THE U50S TO L60S SOUTH, LOW TO MID 50S NORTH.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE AFOREMENTIONED UPPER TROUGH AND ATTENDANT SURFACE LOW OVER THE
GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY, SHUNTING SFC COLD
FRONT IN OUR DIRECTION FRIDAY INTO FRIDAY NIGHT. LOCAL AREA
REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE
60S...PRECIPITABLE WATER VALUES ~+2SD AND INCREASING LLVL
STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE WILL LIKELY
BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND
EVENING ACROSS THE REGION. SHOULD BE NOTED THAT THE HIGHER END OF
INSTABILITY PROFILES ABOVE 2K J/KG HAVE BEEN DISCOUNTED FOR NOW
GIVEN PREFRONTAL CLOUDS AND UNCERTAINTY OF SHRA COVERAGE EARLY
FRI MORNING. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK
OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS.
THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON
THROUGH FRI EVENING AS THE FRONT PUSHES ACROSS THE AREA. PREVIOUS
FORECAST DEPICTING CHC POPS RAMPING INTO LIKELY RANGE DURING THIS
PERIOD HAS BEEN RETAINED, WITH RAIN CHCS DROPPING OFF QUICKLY FROM
NORTHWEST TO SOUTHEAST FRIDAY NIGHT. QUITE WARM ON FRIDAY WITH A
FULL DAY OF COMPRESSIONAL HEATING ON WARM SOUTHERLY FLOW. LOOK FOR
HIGHS IN THE MID 80S ALONG THE COASTAL PLAIN, UPPER 70S TO AROUND
80 INLAND.
COLD FRONT SLIDES OFFSHORE TO BEGIN THE DAY SAT. HIGH PRESSURE
BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT START TO THE
WEEKEND WITH HIGHS IN THE U60S NORTH TO LOW 70S SOUTH UNDER A
MOSTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN
DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL
RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL
AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW
OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE
MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS.
FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS
FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT
AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE
MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD
INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES
AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED
SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING
TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE
SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST
TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE
LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP
FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST
DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE
REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S
COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT
PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE
TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO
MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO
RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA...
ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED
EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO
THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER
ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID
MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE
ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS
OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY
THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR
CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS
MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS
THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM
FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS
PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND
INTERACTS WITH THE WARM FRONT.
BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE
ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY
AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES.
RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM
WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS
TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY
SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER
OF THE WEEKEND.
&&
.MARINE...
THUNDERSTORMS WILL CROSS THE WATERS THIS MORNING AND THEN COME TO AN
END ACROSS SRN COASTAL WATERS BY MID TO LATE MORNING. OTHERWISE...A
FRONT THAT CROSSED THE WATERS ON WED WILL REMAIN STALLED ACROSS THE
CAROLINAS TODAY. PERSISTENT N-NE WINDS AOB 15KT HAVE KEPT SEAS
ELEVATED BTWN 4-7FT FROM FENWICK ISLAND TO THE VA/NC BORDER. SEAS
WILL SLOWLY SUBSIDE BELOW 5FT FOR COASTAL WATERS SOUTH OF PARRAMORE
ISLAND BY THIS AFTN...AND REMAIN AROUND 5FT CLOSER TO 20NM FOR NRN
COASTAL WATERS TODAY THROUGH MOST OF FRIDAY BEFORE FALLING BELOW
5FT/SCA THRESHOLDS.
THE STALLED FRONT LIFTS NWD AS A WARM FRONT TONIGHT INTO EARLY FRI
MORNING. WINDS TONIGHT WILL BEGIN E-SE AOB 15KT AND THEN BECOME MORE
SLY BEHIND THE WARM FRONT (15-20KT COASTAL WATERS...AOB 15KT
BAY/RIVERS/SOUND). SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI
MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN
APPROACHING COLD FRONT. WINDS WILL AVERAGE 15-20KT WITH GUSTS OF 25-
30KT DURING THE AFTN. SEAS WILL AVERAGE 3-4FT TONIGHT INTO FRI
MORNING AND THEN BUILD TWD 5FT FROM PARRAMORE ISLAND TO CAPE CHARLES
LIGHT BY MID-LATE FRI MORNING. WAVES 2-3FT TONIGHT WILL THEN AVERAGE
3FT ON FRI. THE COLD FRONT CROSSES THE WATERS FRI NIGHT WITH STRONG
THUNDERSTORMS EXPECTED. MAIN IMPACTS WILL BE GUSTY AND ERRATIC
THUNDERSTORM WINDS WITH HEAVY RAINFALL. MARINERS SHOULD BE AWARE OF
RAPIDLY CHANGING CONDITIONS AND PLAN FOR A QUICK ROUTE TO SAFE
HARBOR WHEN NEEDED LATE FRI AFTN/EVENING. BEHIND THE COLD FRONT FRI
NIGHT...A COOLER AIRMASS DOES NOT ARRIVE UNTIL DURING THE DAY ON
SAT. A DAYTIME ARRIVAL OF THE COOLER AIR WILL DECREASE CHANCES FOR
POST-FRONTAL SCA WINDS. EXPECT W-N WINDS ON SAT AOB
15KT...DECREASING TO AOB 10KT SAT NIGHT AS HIGH PRESSURE BUILDS INTO
THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN
NIGHT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAS/MAM
LONG TERM...SAM
AVIATION...BMD
MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
208 AM EDT THU APR 9 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE
TO WEAKEN OVERNIGHT...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A
WARM FRONT THURSDAY INTO THURSDAY NIGHT. ANOTHER COLD FRONT
CROSSES THE REGION LATE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WHAT`S LEFT OF A DECAYING OH VLY MCS WAS MOVING THROUGH NE NC AS
OF 10 PM. THIS BATCH OF SHOWERS AND SUB-SEVERE THUNDERSTORMS WILL
MOVE OUT OF THE AREA BETWEEN MIDNIGHT-1AM. OTW...A BACKDOOR COLD
FRONT SITS JUST SOUTH OF THE FA AND SHOULD REMAIN STATIONARY
OVERNIGHT. THIS WILL ALLOW LOW OVERCAST CONDITIONS TO CONTINUE
OVERNIGHT WITH SFC HIGH PRESSURE RIDGING DOWN INTO THE LOCAL AREA
FROM THE NORTHEAST. THE NEXT BATCH OF PCPN IS MAKING ITS WAY
THROUGH THE OH VLY LATE THIS EVENING AND IS SHOWN BY THE LATEST
HRRR TO MAKE A RUN AT THE FA BY AROUND 08-09Z...THEN MOVING SE
THRU 15Z. THE HRRR DID A GOOD JOB HANDLING THE MCS THIS EVENING SO
WILL LEAN TOWARD ITS SOLUTION OVERNIGHT AND HAVE ADJUSTED POPS
ACCORDINGLY. LOWS TONIGHT FROM NR 40 MD EASTERN SHORE TO THE
LOW/MID 50S SW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
THE FRONT WILL WEAKEN...WITH DEVELOPING SW FLOW EVENTUALLY
PUSHING IT BACK NWD AS A WARM FRONT BY LATE THU. HIGHS THU WILL
RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO M70S WITH
MORE TIME IN THE WARM SECTOR ACROSS SRN/WRN AREAS. POPS REMAIN IN
THE CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN
PERIODS FOR SCT SHRAS...AND ISOLTD TSTMS ESPECIALLY OVER SRN/WRN
AREAS.
THE SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES
LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA
FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL
SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST
CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG
GUSTY WINDS...HAIL AND HEAVY RAIN...AND HV MAINTAINED THIS
MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF THE
FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY COMPARED TO
PREVIOUS DAYS AS THE ENTIRE FA RETURNS INTO THE WARM SECTOR. LOOK
FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE
ACROSS SE AREAS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN
DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL
RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL
AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW
OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE
MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS.
FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS
FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT
AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE
MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD
INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES
AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED
SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING
TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE
SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST
TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE
LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP
FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST
DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE
REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S
COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT
PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE
TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO
MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO
RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA...
ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED
EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO
THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER
ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID
MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE
ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS
OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY
THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR
CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS
MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS
THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM
FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS
PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND
INTERACTS WITH THE WARM FRONT.
BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE
ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY
AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES.
RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM
WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS
TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY
SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER
OF THE WEEKEND.
&&
.MARINE...
UPDATE...COASTAL WATERS FROM CAPE CHARLES LIGHT TO THE VA/NC
BORDER ADDED TO SCA FLAGS THROUGH 700 AM THIS MORNING DUE TO SEAS
OF 4-5 FT.
BACKDOOR COLD FRONT HAS LOCATED JUST SOUTH AND WEST OF THE WATER
THIS AFTERNOON. THE RESULT IS N-NE FLOW...AVG 10-15 KT. STRONGER
GRADIENT EXISTS OVER THE NRN COASTAL WATERS...WHERE A FEW GUSTS 25-
28 KT OBSERVED. SEAS HAVE BUILT TO 6-8 FT OVER THE NRN COASTAL
ZONES...GENERALLY NORTH OF PARRAMORE ISLAND. FARTHER SOUTH...SEAS
AVG 2-4 FT. SCA HEADLINES REMAIN IN EFFECT NORTH OF CAPE CHARLES
LIGHT FOR SEAS. GRADIENT WINDS EXPECTED TO DIMINISH TONIGHT AOB 15
KT...BUT SEAS WILL REMAIN ELEVATED (4-7 FT) AS NE FLOW PERSISTS.
BACKDOOR FRONT REMAINS JUST SOUTH AND WEST OF THE WATER
THURS...SLOWLY LIFTING BACK NWD. FLOW BECOMES MORE ONSHORE...E-NE
GENERALLY 10-15 KT. SEAS REMAIN 4-6 FT NORTH OF PARRAMORE
ISLAND...DROPPING BELOW 5 FT SOUTH. BACKDOOR FRONT LIFTS NORTH OF
THE WATER FINALLY THURS NIGHT-FRI MORNING AS A WARM FRONT. FLOW
BECOMES SLY...INCREASING TO AROUND 15 KT RIVERS/BAY/SOUND AND 20 KT
COASTAL WATERS. MARGINAL SCA CONDITIONS ARE POSSIBLE FRI AFTERNOON
AS THE GRADIENT STRENGTHENS IN ADVANCE OF AN APPROACHING COLD FRONT.
WILL HOLD OFF ON HEADLINES DUE TO 4TH PERIOD AND BEING MARGINAL
ATTM. COLD FRONT CROSSES THE WATERS FRI NIGHT...WITH FLOW BECOMING
NWLY POST FRONTAL. BEST CAA REMAINS NORTH OF THE LOCAL AREA...BUT A
FEW GUSTS TO 20 KT POSSIBLE IN THE BAY AND 25 KT COASTAL WATERS
BRIEFLY LATE FRI NIGHT-EARLY SAT MORNING. SEAS BUILD TO 4-6 FT FRI
NIGHT. HIGH PRESSURE BUILDS OVER THE WATERS THIS WEEKEND...RESULTING
IN SUB-SCA CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...MAS
NEAR TERM...JDM/MAS
SHORT TERM...MAS/MAM
LONG TERM...SAM
AVIATION...BMD
MARINE...BMD/SAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 456 PM EDT WED APR 8 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES
RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND
E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN
ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE
NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT
WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR
PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN
MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET
SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW.
IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER
DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL
DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT
THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS
DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS.
WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND
UPPER 40S.
SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES
DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY
SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS.
INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN
SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A
AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI
LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF
MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE
COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING
WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP
CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO
FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T
FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS
TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT
ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY
CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU.
AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE
LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME
MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE
AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE
UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W
WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN
UPPER MI/WRN LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM EDT THU APR 9 2015
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON IMPACT OF EXITING LO
PRES ON FRI/TRAILING SHRTWV AND NEXT CHC FOR RA SUN INTO MON. WHILE
FRI WL STILL BE CHILLY IN THE STRONG NW FLOW LEFT IN THE WAKE OF THE
DEPARTING LO... EXPECT TEMPS TO RISE ABOVE NORMAL AS A MORE ZONAL
PACIFIC FLOW DOMINATES STARTING ON SAT.
FRI...AS MAIN NEGATIVELY TILTED SRN BRANCH SHRTWV WITH ACCOMPANYING
990MB OR SO SFC LO JUST E OF THE SAULT AT 12Z FRI LIFT TO THE NE...
LARGER SCALE DEEP LYR QVECTOR CNVGC WL EXIT AS WELL IN THE MRNG. THE
00Z GFS IS A BIT SLOWER WITH THIS PROCESS DUE TO A FARTHER W TRACK
OF THE SHRTWV/SFC LO...MAINTAINING MORE SGNFT PCPN AND DEEP LYR
QVECTOR CNGVC A BIT LONGER. SINCE THE MODELS DO NOT SHOW A QUICK
PHASING OF THIS SRN BRANCH SHRTWV AND A NRN BRANCH DISTURBANCE
MOVING INTO NRN MN ON FRI MNRG...TENDED AWAY FM THIS SLOWER...
DEEPER SCENARIO. LATEST NCEP DISCUSSION SUPPORTS THE DECISION TO
RELY MORE HEAVILY ON THE 00Z NAM. BUT THE NAM HAS SLOWED DOWN THE
EXIT OF THE SHARPER DYNAMIC FORCING...SO COORDINATED WITH SHORT TERM
FCSTR TO EXTEND WINTER WX HEADLINES THRU FRI MRNG FOR THE N HALF OF
THE HEADLINE AREA. WHILE THE DEPARTURE OF THE SRN BRANCH DYNAMIC
FORCING WL BRING A DIMINISHING TREND TO THE ACCOMPANYING PCPN BY LATE
MRNG...MODELS ARE IN GOOD AGREEMENT SHOWING THE NRN BRANCH SHRTWV
ACCOMPANIED BY SOME FAIRLY SHARP DPVA/DEEP LYR QVECTOR CNVGC DIGGING
INTO THE UPR LKS AND MAINTAINING A SHARP CYC NW FLOW. H925 ARE WINDS
FCST AS HI AS 35-45KTS UNDER THE H85 THERMAL TROF TRAILING THE
DEPARTING LO. WHILE THE PASSAGE OF THE NRN BRANCH DISTURBANCE LATER
IN THE DAY AND ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC WL
RESULT IN A WEAKENING OF THE CYC FLOW OVER THE W DURING THE
AFTN...SUSPECT SN WL BE RATHER PERSISTENT OVER THE E HALF OF THE CWA.
IN FACT...THE 00Z NAM SHOWS ARND 0.35 INCH OF PCPN FALLING AS SN AT
ERY...AND MANY OF THE HIER RES MODELS SHOW SIMILAR QPF. SO BUMPED UP
POPS OVER ESPECIALLY THE NE HALF OF THE CWA. EVEN THOUGH THE PRES
RISE CENTER BEHIND THE DEPARTING LO WL PASS TO THE S OF UPR MI AND
ELIMINATE AN ISALLOBARIC WIND COMPONENT...FRI WL BE QUITE WINDY
ESPECIALLY OVER THE E...WHERE WIND GUSTS NEAR LK SUP MAY AT LEAST
APRCH ADVY CRITERIA. WITH THE NW FLOW OFF MORE EXTENSIVE ICE COVER
ACROSS THE E HALF OF THE LK AND MORE PERSISTENT PCPN THERE...LOWERED
FCST HI TEMPS OVER THE ERN CWA.
FRI NGT...AFTER THE NRN BRANCH SHRTWV DIGS INTO THE CENTRAL GREAT
LKS ON FRI EVNG...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC WL OVERSPREAD
THE ERN CWA...ENDING LINGERING PCPN THERE. STEADY H5 HGT RISES THAT
ARE FCST TO APRCH 100M BTWN 00Z-12Z SAT IN ADVANCE OF TRAILING
SHRTWV/SFC RDG AXIS WL BRING CLRG SKIES AS THE LLVL FLOW BECOMES
MORE ACYC. RATHER STEADY NW BACKING W FLOW TO THE NE OF HI CENTER
MOVING FAIRLY FAR TO THE SW AND INTO THE MID MS RIVER VALLEY WL TEND
TO LIMIT THE DIURNAL TEMP DROP...BUT TEMPS SHOULD STILL FALL INTO
THE TEENS OVER SOME SN ACROSS THE INTERIOR W HALF...WHICH WL BE
CLOSER TO THE WEAKER PRES GRADIENT AND SEE THE EARLIER INFLUX OF
PWAT AOB 0.25 INCH.
SAT...AS SFC RDG AXIS EXTENDING N OF SFC HI CENTER CROSSING THE
LOWER LKS/OH RIVER VALLEY PASSES OVER THE UPR LKS...EXPECT A MOSUNNY
DAY. AS LARGER SCALE SUBSIDENCE/WAA IN THE SW FLOW ON THE BACK SIDE
OF THE RDG LIFT H85 TEMPS UP TO 4C OVER THE W BY 00Z SUN...EXPECT
TEMPS TO REBOUND INTO THE 50S AWAY FM LK MODERATION THAT WL IMPACT
MAINLY THE ERN CWA. READINGS MAY EVEN APRCH 60 IN THE DOWNSLOPE
AREAS OVER THE W.
SAT NGT...AS THE SFC HI PRES SHIFTS TO THE E...WAA/ISENTROPIC ASCENT
WL BRING INCRSG MID CLDS. SOME OF THE MODELS EVEN GENERATE SOME LGT
RA SHOWERS AT THE NOSE OF H85 SW LLJ UP TO 45-50 KTS UNDER
TIGHTENING PRES GRADIENT WITH THE APRCH OF SHRTWV DOWNSTREAM OF A
DEEPENING TROF FARTHER W IN THE NRN PLAINS. INITIAL MSTR RETURN DOES
NOT APPEAR TO BE THAT SGFNT...SO WL GO WITH JUST LO CHC POPS FOR NOW
OVER THE NW HALF OF THE CWA. COMBINATION OF STEADY SW WIND AND
INCRSG CLDS WL LIMIT THE DIURNAL TEMP FALL...ESPECIALLY IN THE
DOWNSLOPE AREAS OVER THE W.
SUN/SUN NGT...AS FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS IN
ADVANCE OF UPR TROF MOVING E FM THE NRN PLAINS OVERSPREAD UPR MI AND
THE STRONG SW FLOW TAPS MORE COPIOUS MSTR THAT LIFT PWAT CLOSE TO 1
INCH BY 00Z MON...EXPECT MORE NMRS SHOWERS TO OVERSPREAD UPR MI ON
SUN AFTN. BUT THIS PCPN WL THEN END W-E SUN NGT AS ACCOMPANYING
PACIFIC TYPE COLD FNT CROSSES THE UPR LKS AND BRINGS AN INFLUX OF
DRIER AIR IN ADVANCE OF SFC HI PRES. SUSPECT THE RUNOFF FM THE RA AS
WELL AS THE RATHER QUICK SN MELT ACCOMPANYING THE FAIRLY DRAMATIC
WARMUP MAY CAUSE AREA RIVERS TO RISE FAIRLY QUICKLY.
EXTENDED...INCOMING HI PRES/DRY AIRMASS WL BRING A MOSUNNY DAY FOR
MON. SINCE THE AIRMASS WL A MARITIME POLAR PACIFIC ONE...MAX TEMPS
SHOULD RISE INTO THE 50S AWAY FM LK MODERATION. THEN AN APRCHG WARM
FNT ASSOCIATED WITH A DISTURBANCE LIFTING NE INTO THE PLAINS WL
BRING A RETURN FOR RA CHANCES NEXT TUE/WED. TEMPS WL BE ABOVE NORMAL
WITH PACIFIC AIRMASS IN PLACE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 126 AM EDT THU APR 9 2015
DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS
MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS
TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS
AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE
MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY
EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN
CHANGING OVER TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EDT THU APR 9 2015
AS A DEEPENING LO PRES MOVES FROM THE PLAINS THRU THE CENTRAL GREAT
LAKES TONIGHT AND INTO SE CANADA ON FRI...EXPECT ENE WINDS UP TO 20
KTS TO BACK TO THE NNW...AND INCREASE UP 35-45 KT GALES OVER MUCH OF
THE E HALF OF THE LAKE BY LATE TONIGHT. OPTED TO ISSUE GALE WARNINGS
FOR THE E HALF. THESE GALE FORCE NNW WINDS WILL THEN DIMINISH ON FRI
AFTERNOON INTO EARLY EVENING AS THE LO PRES EXITS FARTHER TO THE NE
AND THE PRES GRADIENT WEAKENS IN ADVANCE OF AN APPROACHING HI PRES
RIDGE. LIGHTER WINDS ON SAT WILL THEN BACK TO THE SW FOLLOWING THE
PASSAGE OF THE RIDGE AXIS TO THE E. AS A COLD FRONT APPROACHES ON
SUN...EXPECT SSW WINDS TO INCREASE UP TO 20-25 KTS. AFTER THE FRONT
PASSES ON SUN NIGHT...WINDS WILL SHIFT TO THE W AND DIMINISH QUICKLY
WITH THE APPROACH OF ANOTHER HI PRES ON MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR
MIZ002-009-010.
WINTER STORM WARNING FROM 10 PM THIS EVENING TO NOON EDT FRIDAY
FOR MIZ001-003-004-084.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
MIZ005.
LAKE SUPERIOR...
GALE WARNING FROM 8 AM TO 8 PM EDT FRIDAY FOR LSZ251-267.
GALE WARNING FROM 5 AM TO 5 PM EDT FRIDAY FOR LSZ249-250-266.
GALE WARNING FROM 5 AM TO 2 PM EDT FRIDAY FOR LSZ244-245-248-264-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 AM EDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 456 PM EDT WED APR 8 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES
RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND
E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN
ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE
NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT
WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR
PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN
MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET
SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW.
IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER
DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL
DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT
THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS
DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS.
WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND
UPPER 40S.
SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES
DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY
SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS.
INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN
SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A
AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI
LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF
MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE
COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING
WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP
CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO
FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T
FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS
TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT
ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY
CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU.
AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE
LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME
MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE
AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE
UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W
WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN
UPPER MI/WRN LAKE SUPERIOR.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 456 PM EDT WED APR 8 2015
COMPLEX FORECAST FRONT LOADED IN FIRST PERIOD OF LONG TERM. HIGH
IMPACT WEATHER EXPECTED IN FORM OF RAIN CHANGING TO HEAVY SNOW.
MAIN FACTORS COMING INTO FOCUS FOR THURSDAY NIGHT WEATHER. FIRST
ALOFT...UPPER TROUGH OVER THE INTERIOR WESTERN CONUS THIS MORNING
MOVES TO UPPER MISSISSIPPI RIVER VALLEY BY THURSDAY EVENING WHILE
SHORTWAVE TROUGH DIGGING OVER NORTHERN SASKATCHEWAN THIS AFTN MOVES
TO AXIS FM NORTHERN ONTARIO TO SOUTHERN MANITOBA. MAIN JET STREAK
LIFTS OVER NORTHERN ONTARIO INTO QUEBEC ON THURSDAY EVENING WHILE
ANOTHER JET WILL BE IN PROCESS OF EXITING TOWARD GREAT LAKES. AS THE
PLAINS JET ARRIVES OVER THE GREAT LAKES THURSDAY EVENING...LEAD
SHORTWAVE TROUGH IS FORECAST TO BECOME MORE NEGATIVELY TILTED AS IT
LIFTS OVER THE UPPER GREAT LAKES. FOR MOST PART...LEAD WAVE DRIVES
STRENGTH AND TRACK OF H85-H7 TROUGH AND PRIMARY SFC LOW...WHICH
TRACKS FM IOWA AT 00Z FRIDAY TO NORTHERN LK MICHIGAN/NORTHERN LOWER
MICHIGAN BY 06Z FRIDAY AND TO EAST OF SAULT STE MARIE BY 12Z FRIDAY.
MODELS CONTINUE TO DIFFER ON WESTWARD EXTENT OF SFC LOW WHICH
AFFECTS WHERE SWATH OF HEAVY QPF WELL OVER 1 INCH OCCURS ROUGHLY 00Z-
09Z ON FRIDAY. GIVEN VERY STRONG LIFT FM COUPLED JET STRUCTURE AND
ENHANCED DIVERGENCE ALOFT AND PERSISTENT STRONG MID-LEVEL FGEN ALONG
WITH COPIOUS DEEP MOISTURE THAT SHOULD BE ABLE TO TRANSLATE INTO THE
DEEPENING SYSTEM AS MAIN INFLOW FOR TSRA SHOULD STAY FAR ENOUGH
SOUTHEAST OF UPR MICHIGAN...TEND TO BELIEVE WETTER IDEAS OFFERED UP
BY NAM/GFS SHOWING WELL OVER 1 INCH OF QPF. THOUGH ECMWF REMAINS
DRIER...IT HAS SHOWN NOTEABLE TREND TOWARD STRONGER SYSTEM THE LAST
DAY...SO THAT IS ENCOURAGING AT LEAST FROM THE FORECAST STANDPOINT.
RUNNING WITH THE STRONGER/WETTER IDEA...MAIN STICKING POINT IS HOW
QUICK THE RAIN CHANGES TO SNOW ON THURSDAY NIGHT. THE EARLIER THAT
SWITCHOVER OCCURS...THE MORE THAT HEAVY QPF WILL GO TOWARD WET HEAVY
SNOW ACCUMULATION. NAM SOUNDINGS SHOW WARM LAYER BTWN 900MB-800MB
VCNTY OF L`ANSE TO WATERSMEET AT 00Z...THEN TO CRYSTAL FALLS AND
MARQUETTE/HARVEY BY 03Z...BEFORE PUSHING THIS ON THE MUNISING AND
ESCANABA BY 06Z. GFS AND GEM-REGIONAL ARE FARTHER WEST WITH WARM
LAYER ALOFT...THOUGH THEY BOTH TRENDED A BIT EAST WITH TRACK OF SFC
LOW ON THE 12Z RUNS. EXPECT HEAVY WET SNOW TO IMPACT PARTS OF
WESTERN HALF OF UPR MICHIGAN. RETREATING WARM LAYER TO START COULD
ALSO RESULT IN SLEET OF FZRA BEFORE CHANGE TO SNOW OCCURS.
DECIDED TO ISSUE A WINTER STORM WATCH FOR WESTERN UPR MICHIGAN AS
THERE SHOULD BE A NARROW STRIPE OF POSSIBLE VERY HEAVY WET SNOW
THURSDAY NIGHT. GIVEN THE FORCING AND MOISTURE...LOCALIZED AMOUNTS
OVER 8 INCHES SEEM POSSIBLE. MAIN QUANDARY WAS HOW FAR WEST AND EAST
TO PUSH THE WATCH. LEANED A BIT TOWARD THE FARTHER EAST WARM LAYER
IDEA WHICH RESULTED IN BRINGING THE WATCH AS FAR EAST AS MARQUETTE
COUNTY. GIVEN DECENT CHANCE THAT PRECIP STAYS MAINLY RAIN WELL INTO
THE EVENING FOR DICKINSON COUNTY LEFT THEM OUT FOR NOW...THOUGH
COULD SEE NEED FOR ADVY FOR EVENTUALLY SLOPPY INCH OR TWO OF SNOW.
CORRIDER OF HEAVY SNOW LIKELY WILL NOT MAKE IT AS FAR WEST AS IWD
THOUGH LATEST HPC/WWD GRAPHICS STILL HIT FAR WEST FOR DECENT AMOUNT
OF SNOW...BUT SINCE EASTERN PORTIONS OF GOGEBIC COUNTY INTO
ONTONAGON COUNTY WOULD BE IMPACTED BY THE HEAVY SNOW WITH LATEST
THINKING...INCLUDED GOGEBIC AS WELL. ESSENTIALLY SINCE THIS EVENT
COULD BE VERY HIGH IMPACT DECIDED TO GO THIS ROUTE INSTEAD OF HAVING
AN SPS OUT ONLY. WILL TRY TO CONVEY THE UNCERTAINTY DUE TO BOTH
LOCATION OF HEAVIER SNOW AND PTYPE IN THE WSW STATEMENT. COORD WITH
DLH AND GRB ON SNOW AMOUNTS/HEADLINE TIMING.
LOW PRESSURE EXITS OVER EASTERN CANADA FRIDAY INTO FRIDAY NIGHT.
LINGERING LOW-LEVEL MOISTURE/THERMAL TROUGHING AND ADDITIONAL
FORCING FM THE NORTHERN STREAM WAVE DROPPING OVER THE AREA SUPPORTS
CHANCE POPS FOR SNOW ON FRIDAY THOUGH MOST OF THE BIGGER SNOW WILL
BE DONE BY DAYBREAK FRIDAY. KEPT WITH TEMPS MAINLY IN THE 30S ON
FRIDAY. BREEZY CONDITIONS TOO...ESPECIALLY NEAR LK SUPERIOR IN THE
MORNING HOURS. SFC RIDGE CROSSES FRIDAY NIGHT AND TEMPS COULD DIP
INTO THE TEENS. EXPECT THIS TO BE THE LAST NIGHT THROUGH THE LONG
TERM WHERE TEMPS DROP BLO FREEZING.
TEMPS THIS WEEKEND LOOKS WARMER...MUCH WARMER. HIGH CLOUDS INCREASE
LATE SATURDAY AND SATURDAY NIGHT AHEAD OF LOW PRESSURE TROUGH THAT
MOVES FM SCNTRL CANADA TO NORTHERN PLAINS ON SUNDAY. MIXING HEIGHTS
UP TO H85 WITH SW WINDS SUPPORT READINGS WELL INTO THE 50S. COOLEST
TEMPS OVER EAST CWA WITH FLOW COMING OFF LK MICHIGAN. SOME LGT RAIN
MAY DEVELOP AHEAD OF THE TROUGH ON SUNDAY AS GFS/ECMWF HAVE BEEN
SHOWING FOR A WHILE NOW. EVEN SO...WARMER TEMPS ALOFT AND WARMER MIN
TEMPS ON SATURDAY NIGHT ALLOW MANY AREAS TO REACH 60 DEGREES. SO ANY
SNOW THAT DOES OCCUR THURSDAY NIGHT INTO FRIDAY SHOULD QUICKLY MELT
THIS WEEKEND.
FURTHER...ONCE THE TEMPS RISE ABOVE FREEZING ON SATURDAY THEY SHOULD
REMAIN ABOVE FREEZING THROUGH MUCH OF NEXT WEEK SO WE SHOULD ALSO
BEGIN TO MELT GOOD PORTION OF THE SNOWPACK THAT REMAINS OVER MAINLY
NORTHERN UPPER MICHIGAN. SHOULD SEE AREA RIVERS AND STREAMS BEGIN TO
RESPOND WITH THE SNOWMELT AND RUNOFF. ADDITIONAL RAINFALL POSSIBLE
TUESDAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM AND WARM FRONT MOVE
TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES. ANY RAINFALL FM
THIS SYSTEM WOULD ONLY ADD TO THE RUNOFF. SEEMS THAT AFTER THIS
WINTRY SYSTEM WE MIGHT JUST SHIFT INTO THE MAIN SNOWMELT HYDROLOGY
PERIOD OF THE SPRING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 126 AM EDT THU APR 9 2015
DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS
MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS
TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS
AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE
MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY
EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN
CHANGING OVER TO SNOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 PM EDT WED APR 8 2015
HIGH PRES MOVING E ACROSS QUEBEC AND LOW PRES DEVELOPING OVER THE
CNTRL/SRN PLAINS WILL KEEP LAKE SUPERIOR UNDER GENERAL E TO NE WINDS
OF 10-20KT THRU EARLY THU AFTN. AS THE LOW PRES TRACKS NE ACROSS
NORTHERN LAKE MI THU EVENING AND INTO ONTARIO FRI MORNING...WINDS
WILL BACK TO THE NW. OVER THE CNTRL PART OF LAKE SUPERIOR...THE WIND
WILL ALSO INCREASE TO 20-30KT...AND OVER ERN LAKE SUPERIOR N TO NW
GALES WILL DEVELOP BY FRI MORNING. WINDS WILL THEN DIMINISH W TO E
FRI AFTN THRU FRI NIGHT AS HIGH PRES BUILDS ACROSS THE MISSISSIPPI
VALLEY. LIGHT WINDS UNDER 20KT ARE EXPECTED SAT AS THE HIGH PRES
RIDGE PASSES ACROSS THE WRN GREAT LAKES. AS THE RIDGE SHIFTS E AND A
LOW PRES TROF MOVES E ACROSS THE NRN PLAINS...WINDS WILL THEN
INCREASE SAT NIGHT/SUN...PROBABLY REACHING 15-25KT OR MORE OVER AT
LEAST THE E HALF OF LAKE SUPERIOR ON SUN. THE TROF WILL CROSS THE
UPPER GREAT LAKES SUN NIGHT...BRINGING A WIND SHIFT TO THE W.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR
MIZ001>005-009-010-084.
LAKE SUPERIOR...
GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR
LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
328 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD
THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS
SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY
WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA
THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI
ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH
CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE
AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN
ALL LIQUID.
THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST
AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW
WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON
THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME
PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT
ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF
ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST
SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN.
HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A
POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM
IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO
FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS
AND HAVE REMOVED.
TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE
AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE
PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND
THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE
AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST
TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL
FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST
POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT
ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW
PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME
ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED.
ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE
UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE
MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO
REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY
MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS
WITH DIURNAL HEATING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS
WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND
INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE
TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL
DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL
EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE
NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND
POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE
FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE
BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE
NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION
BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE
BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS
IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF
OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE.
RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY
NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE
30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR
IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL
KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL
SIDE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1223 AM CDT THU APR 9 2015
A SURFACE LOW WAS LOCATED IN THE WESTERN KS/EASTERN CO REGION LATE
THIS EVENING AND IS FORECAST TO LIFT INTO IOWA THURSDAY MORNING. WAA
AHEAD OF THIS LOW WILL AID IN DEVELOPING PRECIP ACROSS THE NORTHLAND
TONIGHT THROUGH THURSDAY NIGHT. SHOWERS WERE ALREADY MOVING ACROSS
NORTHERN WISCONSIN AND WE EXPECT COVERAGE TO INCREASE OVERNIGHT. A
WINTRY MIX WILL OCCUR OVER FAR NORTHERN WISCONSIN INTO PORTIONS OF
NORTHEAST MINNESOTA...WITH MAINLY RAIN AT KHYR UNTIL LATE THURSDAY
AFTERNOON.
MVFR/IFR CONDITIONS WILL PREVAIL THROUGH THURSDAY MORNING...THEN
SOME CLEARING WILL OCCUR OVER WESTERN TAF SITES...AND GRADUALLY MOVE
EAST TO KHIB/KDLH. ANOTHER POTENT SHORTWAVE WILL MOVE SOUTH THURSDAY
NIGHT AND BRING SOME SNOW SHOWERS WITH IT. WE ADDED A VCSH AT KINL
LATE IN THE PERIOD.
FOG WILL BE POSSIBLE AROUND LAKE SUPERIOR...ESPECIALLY AT KDLH. WE
EXPECTED LOWER VSBYS TO OCCUR BY NOW BUT HAVE YET TO SEE THAT. WE
WILL DELAY THE LOWER VSBYS UNTIL LATE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 32 48 30 / 70 20 20 10
INL 50 30 48 28 / 10 40 10 0
BRD 49 31 51 29 / 60 20 20 10
HYR 42 31 47 27 / 90 80 30 10
ASX 38 31 45 29 / 100 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...BJT
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU APR 9 2015
TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD
HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE
PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO
SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC
OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB
TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C
ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL
DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF
NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF
RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN
THE SANDHILLS.
THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE
UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD
MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING
CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT
THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE
NORTHWEST AT THE SAME TIME.
THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER
40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY
EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB
WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH.
HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES
FOR LOWS IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU APR 9 2015
RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY
WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH
PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK
ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY
EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E
GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE
LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY
SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL
NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR
ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS
WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS.
WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO
EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP
THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE
DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING
FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY
FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE
RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN
PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF
MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT
CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY
AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA.
BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL
LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE
NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH
THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE
TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS
TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE
OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE
WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE
GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT
INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT
SPREAD EAST ONTO THE PLAINS.
TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR
ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD
COOL TEMPERATURES BACK BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1153 PM CDT WED APR 8 2015
IFR CEILINGS ARE FORECAST UNTIL 16Z AT KLBF AND KVTN. A STORM
SYSTEM WILL TRACK EAST ACROSS WESTERN NEBRASKA OVERNIGHT AND
THURSDAY BRINGING RA TO KLBF. COLDER AIR MOVING IN TO BRING A MIX
OF RASN OR A POSSIBLE CHANGEOVER TO SN TO KVTN FROM 10Z-15Z.
WINDS 34015G25KT WILL OCCUR AFTER 12Z WITH CEILINGS IMPROVING TO
MVFR BY 16Z AND THEN VFR BY 20Z FOR BOTH TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1133 PM CDT WED APR 8 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT WED APR 8 2015
PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT
AND ALSO SHOWERS ON THURSDAY.
SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD
OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO
SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM
12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP
TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY
AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO.
GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH
HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME
STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA.
OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE
WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP
BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR
SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR
MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE
FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL
MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE
COULD ALSO BE SOME LOCALLY HEAVY RAIN.
SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH
HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST
AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE
LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE
PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH
WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED
FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY.
PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY
NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT
AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT...
MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT.
WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES
SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 PM CDT WED APR 8 2015
WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE
EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS
LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT
INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT
SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1129 PM CDT WED APR 8 2015
IFR TO LIFR CONDITIONS WILL CONTINUE AS A VERY MOIST LOW LEVEL
LAYER REMAINS OVER THE REGION. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL CONTINUE TO SPREAD OVER THE TAF SITES THROUGH
THE MORNING HOURS. DID NOT INCLUDE A MENTION OF THUNDER...BUT WILL
CONTINUE TO MONITOR TRENDS AND AMEND AS NECESSARY. WINDS WILL TURN
TO THE NORTHWEST AS A COLD FRONT DROPS ACROSS THE AREA ON
THURSDAY. GUSTS UP TO 35KTS ARE POSSIBLE LATE THURSDAY MORNING
INTO THURSDAY AFTERNOON. SKIES AND VISIBILITIES MAY BEGIN TO
SCATTER OUT QUICKLY AROUND SUNSET...PERHAPS BECOMING CLEAR BY THE
END OF THE TAF CYCLE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
351 AM EDT THU APR 9 2015
.SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA
TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY
AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR
SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH
THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
IN FOR THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING
OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR
FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY
SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING
WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE
SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY
OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG
MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND
EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH
OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150%
OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING
SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW
OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST
WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH
THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL
AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA
OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS
AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF
THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE
FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS
MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE
MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT
DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST
MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE...
WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS
EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0
C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND
WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO
SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION
COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS
CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS
VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING
THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW
TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR
TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE
PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY
WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER
DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW
VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING
HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE
TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL
STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS
SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING
RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY
DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE
BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY
LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE
TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW
HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL
LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS
TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL
WARM SECTOR. -GIH
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 325 AM THURSDAY...
MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID
LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE...
REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS
FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING
THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW
OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID
MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT
WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30
KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST
BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A
FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF
WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO
OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING
TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND
INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE
LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG
LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK...
POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY.
THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85
(WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE
FRONT MAY NOT CLEAR UNTIL LATE. -GIH
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 350 AM THURSDAY...
SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH
CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE
WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES.
HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S
SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT.
MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON
MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD
FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON
TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE
TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY...
WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S.
THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD
WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO
AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT
AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY
COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT
CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE
MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON...
WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER
AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID
TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1230 AM THURSDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS
THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY.
A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN
PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD
FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE
SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER
1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA
TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR
CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL
SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR
NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL
REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS
TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR
BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH
OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC
DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY
WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL
FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE
TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY
OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT
OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS
AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS
ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN
THOSE LOCATIONS THAT SEE PRECIPITATION TODAY.
LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG
SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY
MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD
MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL
OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH
CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS
WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID
AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT
MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC
REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...RAH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT THU APR 9 2015
.SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA
TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY
AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR
SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH
THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
IN FOR THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING
OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR
FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY
SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING
WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE
SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY
OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG
MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND
EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH
OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150%
OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING
SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW
OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST
WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH
THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL
AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA
OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS
AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF
THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE
FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS
MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE
MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT
DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST
MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE...
WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS
EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0
C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND
WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO
SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION
COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS
CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS
VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING
THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW
TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR
TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE
PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY
WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER
DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW
VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING
HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE
TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL
STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS
SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING
RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY
DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE
BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY
LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE
TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW
HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL
LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS
TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL
WARM SECTOR. -GIH
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 325 AM THURSDAY...
MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID
LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE...
REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS
FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING
THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW
OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID
MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT
WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30
KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST
BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A
FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF
WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO
OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING
TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND
INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE
LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG
LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK...
POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY.
THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85
(WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE
FRONT MAY NOT CLEAR UNTIL LATE. -GIH
&&
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 320 PM WEDNESDAY...
MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW
ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE
APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS
SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH
GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S
NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS
SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS
MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY
FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN
THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN
AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING
BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN
THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY
BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT
AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY
NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE
MID 50S TO LOWER 60S.
TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS
ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE
IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT
SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN
THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB
THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL
COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO
WITH LOWS IN THE MID 40S.
THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS
SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER
THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE
MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL
INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE
THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER
AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A
LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN
THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE
MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED
TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON
HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1230 AM THURSDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS
THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY.
A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN
PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD
FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE
SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER
1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA
TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR
CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL
SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR
NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL
REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS
TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR
BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH
OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC
DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY
WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL
FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE
TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY
OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT
OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS
AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS
ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN
THOSE LOCATIONS THAT SEE PRECIPITATION TODAY.
LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG
SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY
MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD
MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL
OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH
CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS
WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID
AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT
MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC
REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...22
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 AM EDT THU APR 9 2015
.SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA
TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY
AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR
SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH
THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
IN FOR THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING
OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR
FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY
SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING
WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE
SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY
OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG
MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND
EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH
OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150%
OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING
SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW
OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST
WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH
THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL
AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA
OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS
AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF
THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE
FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS
MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE
MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT
DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST
MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE...
WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS
EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0
C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND
WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO
SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION
COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS
CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS
VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING
THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW
TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR
TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE
PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY
WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER
DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW
VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING
HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE
TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL
STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS
SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING
RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY
DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE
BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY
LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE
TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW
HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL
LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS
TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL
WARM SECTOR. -GIH
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 300 PM WEDNESDAY...
TO BE UPDATED SHORTLY.
&&
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 320 PM WEDNESDAY...
MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW
ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE
APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS
SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH
GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S
NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS
SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS
MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY
FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN
THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN
AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING
BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN
THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY
BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT
AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY
NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE
MID 50S TO LOWER 60S.
TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS
ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE
IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT
SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN
THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB
THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL
COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO
WITH LOWS IN THE MID 40S.
THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS
SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER
THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE
MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL
INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE
THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER
AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A
LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN
THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE
MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED
TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON
HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1230 AM THURSDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS
THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY.
A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN
PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD
FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE
SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER
1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA
TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR
CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL
SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR
NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL
REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS
TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR
BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH
OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC
DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY
WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL
FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE
TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY
OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT
OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS
AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS
ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN
THOSE LOCATIONS THAT SEE PRECIPITATION TODAY.
LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG
SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY
MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD
MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL
OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH
CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS
WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID
AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT
MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC
REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...
LONG TERM...22
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
355 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU APR 9 2015
HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW
ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY
THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP
AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS
AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH
DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE
CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH
OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT
MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE
WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE
CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER
TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS
EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS
AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM
TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT
RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW
POPCORN SHOWERS THIS AFTERNOON.
FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION
CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS
SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST.
CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS
ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT
EAST THROUGH THE EARLY MORNING.
THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH
UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A
NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH
DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE
FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH
MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF
SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z
THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z
FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE.
EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING
TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA
BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO
THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF
AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM
WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS
THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT
AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR
THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL
SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A
CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND
DISSIPATE QUICKLY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU APR 9 2015
THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE
PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN
U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW
POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE
BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS
COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO
NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE
ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW
AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND
SOLUTION.
FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT
FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER
RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER
AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE
WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL
RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE
RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF
THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN
EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME.
A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS
LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER
LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL
PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND
BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE
TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH
TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE
SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE
SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL
RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES
SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH
STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO
MONITOR.
LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE
APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT
SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON
THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE
WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE
REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM
AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL
UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD
MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S.
TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY
AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND
HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN
STORE MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 355 AM CDT THU APR 9 2015
LIFR CIGS/VSBYS WILL CONTINUE AT KDIK THROUGH 14Z BEFORE
IMPROVING BACK TO VFR BY 16Z-17Z. ELSEWHERE...MVFR CIGS AND VSBYS
POSSIBLE AT KBIS/KJMS THROUGH 14Z. MVFR VSBYS ALSO POSSIBLE AT
KISN/KMOT AS SURROUNDING SITES SUCH AS WATFORD CITY AND TIOGA
REPORTING VISIBILITIES BETWEEN 2SM AND 6SM. ALL TERMINALS ARE
EXPECTED TO RETURN TOWARD VFR STATUS BY 15Z-17Z TODAY. EXPECT A
FAIRLY LARGE BUT SHALLOW CUMULUS FORMATION ACROSS WESTERN AND
CENTRAL NORTH DAKOTA 18Z THURSDAY THROUGH 00Z FRIDAY. THE CUMULUS
WILL DISSIPATE QUICKLY AROUND SUNSET WITH A CLEAR SKY TO FOLLOW
THROUGH 12Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 AM EDT THU APR 9 2015
.SYNOPSIS...
ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT.
COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT
APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
830 PM UPDATE...
EXPANDED FFA FARTHER N TO ACCOUNT FOR WHERE COMPLEX IS COMING IN
FROM THE W...AND WENT ACROSS THE NRN TIER TO ACCOUNT FOR CONVECTION
ALONG THE 300K ISENTROPIC SFC GRADIENT H8-H85 THERE.
745 PM UPDATE...
UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE
W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC
GRADIENT H8-H85 ACROSS THE NRN TIER.
630 PM UPDATE...
UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL
ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE.
PREV DISCN...
BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING
THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH
AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR
TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS
BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE
LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN
CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS
BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A
HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER
HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES
IN 3 HOURS TO START CREATING LOCAL PROBLEMS.
THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY
MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM
SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE
WEST THURSDAY AFTERNOON.
ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE
PERIOD...AS EXISTING FORECAST LOOKED DECENT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES
ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND
GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS
ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO
EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER
IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY
BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY
AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL
LEVELS BEHIND THE FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND
STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT
BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS
ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA
BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY
TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN
PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR
WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR
THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR
NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO
CONVECTION/HIGHER POPS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY
THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR
RESTRICTIONS. SOME MVFR FOG IS POSSIBLE EARLY THIS MORNING IN AREAS
RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY
VFR CLOUDS CAN BE EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD
VARY. UNCERTAIN ON POST-RAIN FOG FORMATION EARLY THIS MORNING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 04/09/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M H H H H H M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z FRIDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS LATE THURSDAY
NIGHT AND INTO FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR WVZ005>011-
013>017-019-020-024>026-031.
OH...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR OHZ066-067-
075-076-083>087.
KY...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ101>103-
105.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JMV/MZ/SL
NEAR TERM...TRM/MZ
SHORT TERM...JMV
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 AM EDT THU APR 9 2015
.SYNOPSIS...
A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA
AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST
AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW
PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE
UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD
TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY
ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY.
TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE
COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN
MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS.
REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF
SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL
HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY
WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING
REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES.
BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY
TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE
SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP
GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE.
RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS
SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND
EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY
LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS.
SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL
SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN
ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE
MIDWEST.
BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS
IN THE UPPER 30S TO LOW 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS
CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC
OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC
WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX
VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED
ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS
THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE
LOWER SUSQ VALLEY.
LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN
STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT
OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE
PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH
SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR
SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM
LAYERS.
HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG
AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS.
MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB
FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW
IS EXPECTED ACROSS THE AREA.
ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT
850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR
AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST
MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST.
LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS
IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT
THE BEST HEIGHT FALLS.
ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG
THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT.
ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER
STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE
FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT
IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL
KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY.
LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL
BE THE RULE. THERE HAVE BEEN SLIGHT BREAKS IN SOME OF THE MVFR TO
IFR CIGS AND VSBYS...THOUGH THESE WILL BE THE EXCEPTION AND NOT
THE RULE.
WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH WITH MAY
TAF SITES GOING CALM OVERNIGHT.
AS THURSDAY CONTINUES THE LOW STRATOCU WILL SLOWLY BREAK
UP...WITH IFR CIGS INCREASING TO MVFR TO PERHAPS A BRIEF PERIOD OF
VFR...BEFORE DROPPING DOWN THURSDAY EVENING.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...FITZGERALD/LAMBERT
SHORT TERM...FITZGERALD/LA CORTE/LAMBERT
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
136 AM EDT THU APR 9 2015
.SYNOPSIS...
A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA
AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST
AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW
PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE
UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD
TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY
ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY.
TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE
COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN
MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS.
REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF
SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL
HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY
WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING
REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES.
BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY
TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE
SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP
GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE.
RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS
SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND
EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY
LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS.
SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL
SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN
ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE
MIDWEST.
BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS
IN THE UPPER 30S TO LOW 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS
CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC
OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC
WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX
VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED
ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS
THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE
LOWER SUSQ VALLEY.
LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN
STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT
OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE
PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH
SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR
SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM
LAYERS.
HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG
AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS.
MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB
FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW
IS EXPECTED ACROSS THE AREA.
ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT
850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR
AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST
MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST.
LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS
IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT
THE BEST HEIGHT FALLS.
ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG
THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT.
ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER
STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE
FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT
IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL
KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY.
LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL
BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED.
WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH
THE PERIOD.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/FITZGERALD
LONG TERM...MARTIN
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
112 AM EDT THU APR 9 2015
.SYNOPSIS...
M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH
THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO
CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF
SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE
REGION THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
0515 UTC UPDATE...SKY COVER WAS ADJUSTED PER SATELLITE IMAGERY.
POPS WERE ADJUSTED PER RADAR TRENDS. WINDS WERE UPDATED FROM THE
LATEST MODEL DATA. TEMPERATURES WERE ADJUSTED UP A BIT TODAY AND
DOWN A BIT TONIGHT PER THE LATEST MODEL DATA.
AS OF 1000 PM...THE LATEST SPC MESOANALYSIS PAGE STILL SHOWS
1000-2000 J/KG OF MUCAPE. A COUPLE OF ISOLD TSTMS HAVE POPPED UP IN
THE MIDLANDS...AND THE LAST COUPLE OF HRRR RUNS DO SHOW A FEW MORE
CELLS DEVELOPING OVER THE NEXT FEW HOURS SOUTH OF I-85. SO WILL ADD
A SLGT CHC BACK IN ACRS THE SOUTHEASTERN ZONES. CANNOT RULE OUT A
SEVERE PULSE STORM GIVEN THE CAPE AND 25-30 KTS OF EFFECTIVE SHEAR.
OTHERWISE...THE REST OF THE FCST LOOKS ON TRACK.
AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE
ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT
BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR
THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN.
TEMPS/SKY/WINDS ARE ON TRACK.
AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS
THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING
INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF
SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE
AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN
TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING
MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE
EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY
PRECIP...IF THE LATEST TRENDS HOLD.
AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN
THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS
THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL
APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX
MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE
WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST
FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA.
SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO
BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE
SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING
SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION
ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW
LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT
VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER
LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED
SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES
CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH
LARGE HAIL AND DAMAGING WINDS.
UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL
SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE
ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON
THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE
REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS
AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN
1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK
OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING
IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST
TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY
VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO
EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL
THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE
POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL
DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES
CLOSER TO ANY SHORTWAVE ACTIVITY.
TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT...
WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS
THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL
IN FAIRLY GOOD AGREEMENT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES
TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD
FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL
STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW
STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS
A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING
SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING
REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE
PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT
AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE
DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION
AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE
POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT.
WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG
THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS
WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND
SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE
NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND
850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR
AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT
DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB
A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON
THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL
THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION...
ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE
HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN
BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS
POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS
AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST
AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN
THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP
CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE.
ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A
NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD
IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE
RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW
DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A
DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE
UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO
REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK
SHORT WAVES MOVING THRU THE FLOW.
AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH
POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE
MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES
EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING
DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA
ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW
REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND
ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY
DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE
NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AT KCLT...MODEL TIME HEIGHTS SUGGEST LOW VFR CLOUDS WILL BE PRESENT
FOR MUCH OF THE FORECAST PERIOD...WITH THE CURRENT CIG ERODING AFTER
DAYBREAK. A LOW VFR CIG WOULD RETURN TONIGHT AHEAD OF AN ADVANCING
COLD FRONT. GUIDANCE HAS BACKED OFF ON A DAYBREAK VSBY
RESTRICTIONS...AND WITH A LACK OF RAINFALL YESTERDAY THIS SCENARIO HAS
BEEN ACCEPTED. INSTABILITY WILL BE PRESENT AGAIN TODAY...SUPPORTING
THUNDERSTORMS THAT MAY LINGER INTO THE EVENING AHEAD OF THE
APPROACHING COLD FRONT. ANY RESTRICTIONS WOULD BE ASSOCIATED
WITH PRECIPITATION. WINDS WILL FAVOR THE S AND SW.
ELSEWHERE...VSBY RESTRICTIONS ARE NOT SUPPORTED AT TAF SITES BY A
MODEL CONSENSUS...AND WITH NO RAIN YESTERDAY...THIS OUTCOME HAS BEEN
ACCEPTED. MODEL TIME HEIGHTS SHOW LOW VFR CLOUDS PERSISTING...
ALTHOUGH SATELLITE IMAGERY SHOWS SOME AREAS WHERE HIGH CIRRUS IS THE
PREVAILING CLOUD. LOW VFR CIGS ARE NOT EXPECTED UNTIL THIS AFTERNOON
AHEAD OF AN APPROACHING COLD FRONT. INSTABILITY WILL SUPPORT
THUNDERSTORMS TODAY AND TONIGHT AS THE FRONT ADVANCES...WITH
ASSOCIATED RESTRICTIONS POSSIBLE. WINDS WILL FAVOR THE S AND SW.
OUTLOOK...A COLD FRONT WILL PUSH THROUGH FRIDAY...BRINGING WITH IT
THE POTENTIAL FOR CONVECTION. CONDITIONS IMPROVE FOR THE WEEKEND
AFTER THE FRONT CLEARS THE AREA. MOISTURE RETURNS LATE MONDAY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...ARK/JAT/TDP
SHORT TERM...PM
LONG TERM...RWH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
400 AM CDT THU APR 9 2015
.DISCUSSION...
A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A
GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL
CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE.
AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST
DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS
FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE
OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME
OF THIS ACTIVITY THROUGH DAYBREAK.
THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS
AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE
HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR
OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z.
WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE
LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL
AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID
TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO
2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR
VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE
WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND
DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW
TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM
HELICITY VALUES APPROACHING 200 M2/S2.
EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND
SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL
BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE
PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE
FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN
WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH
30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE.
THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING
IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY
NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT
THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL
MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS.
58
&&
.AVIATION...
/ISSUED 1149 PM CDT WED APR 8 2015/
/06Z TAFS/
SOME MVFR CIGS ARE ALREADY LOCATED AROUND THE AREA BUT MVFR CIGS
ARE EXPECTED TO SPREAD OVER ALL THE TAF SITES BY 09-10Z. GUSTY
WINDS ARE OCCURRING DUE TO DISSIPATING RAIN AND STORMS IN THE
AREA AND THE WINDS OVERNIGHT ARE EXPECTED TO PREVAIL 15-20 KTS
WITH GUSTS UP TO 30 KTS. SOME ADDITIONAL THUNDERSTORMS ARE STILL
POSSIBLE OVERNIGHT AND WILL MAINTAIN A VCTS MENTION IN THE
METROPLEX BETWEEN 09-12Z. CIGS WILL IMPROVE ABOVE 2 KFT BY MIDDAY
THURSDAY AND THEN INTO VFR CATEGORY BY MID-LATE AFTERNOON. ANOTHER
ROUND OF THUNDERSTORMS IS EXPECTED AS A COLD FRONT MOVES ACROSS
THE AREA. THUNDERSTORMS WILL BE POSSIBLE IN THE METROPLEX AHEAD OF
THE FRONT FROM 09/21-10/02Z AND AT KACT BETWEEN 10/03-07Z. THESE
STORMS COULD BE STRONG OR SEVERE WITH A LARGE HAIL AND/OR DAMAGING
WIND THREAT. THE WINDS WILL SHIFT TO THE NORTH THURSDAY EVENING
AS THE FRONT MOVES THROUGH.
JLDUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40
WACO, TX 84 58 73 58 76 / 30 60 20 30 40
PARIS, TX 79 51 73 52 73 / 40 70 10 30 40
DENTON, TX 83 53 73 54 73 / 40 30 10 30 40
MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40
DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40
TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40
CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40
TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40
MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1248 AM CDT THU APR 9 2015
.AVIATION...
A CLUSTER OF SHRA IS MOVING EAST ACROSS THE HILL COUNTRY AND
ESCARPMENT AREAS. HAVE GONE WITH VCSH AT KAUS/KSAT/KSSF OVERNIGHT
AS THIS CLUSTER CONTINUES TO THE EAST. MVFR CIGS HAVE DEVELOPED
FROM THE COASTAL PLAINS TO THE I-35 CORRIDOR. THESE CIGS WILL
SPREAD WEST ACROSS THE HILL COUNTRY TO THE RIO GRANDE PLAINS AND
KDRT OVERNIGHT WITH A BRIEF PERIOD OF IFR CIGS EARLY THURSDAY
MORNING. HOWEVER...THERE IS A POSSIBILITY THAT THE CLUSTER OF
SHRA DISRUPTS THE MVFR CIGS. A DRYLINE WILL MOVE INTO THE EDWARDS
PLATEAU AND PARTS OF THE RIO GRANDE PLAINS MID MORNING INTO
AFTERNOON AND THEN RETREATS BACK WEST THURSDAY NIGHT. SKIES WILL
BECOME VFR BY LATE MORNING AT KDRT. EAST OF THE DRYLINE...CIGS
WILL RISE TO VFR IN THE AFTERNOON. THERE IS SOME POSSIBILITY OF
SHRA/TSRA ALONG AND EAST OF THE DRYLINE. WILL LEAVE MENTION OF
THESE OUT OF THE TAFS DUE TO UNCERTAINTY ON LOCATION. MVFR CIGS
REDEVELOP FROM THE COASTAL PLAINS ACROSS THE I-35 CORRIDOR INTO
THE HILL COUNTRY THURSDAY NIGHT. A COLD FRONT SAGS SOUTH THROUGH
CENTRAL TEXAS LATE TONIGHT AND EXPECT SOME SHRA/TSRA ALONG IT AND
HAVE MENTIONED VCSH AT KAUS. S TO SE WINDS 7 TO 15 KTS PREVAIL.
EXCEPT...W TO NW 4 TO 8 KTS BEHIND THE DRYLINE AND NE BEHIND THE
COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 936 PM CDT WED APR 8 2015/
UPDATE... /RAISED POPS...THUNDER CHANCES WRN THIRD/
FAST PACED CONVECTIVE CLUSTER ARRIVING FROM WEST TX IS A
SOUTHWARD EXTENT OF A BROKEN LINE OF CONVECTION THAT EXTENDS NORTH
INTO NW TX. THE SOUTHERN ENHANCEMENTS ARE LIKELY THE PRODUCT OF
FAVORABLE JET DYNAMICS AND STEEPENING MID LEVEL LAPSE RATES. MOST
OF THE HI-RES RUNS SHOWN THE ACTIVITY WEAKENING BEFORE REACHING
THE I-35 CORRIDOR...BUT DO SHOW SOME AREAS OF LIGHT QPF FROM
LIGHT SHOWERS. WILL EXTEND A MENTION OF SPRINKLES INTO SOUTHEAST
COUNTIES AND BEEF UP POPS OVER MAINLY VAL VERDE COUNTY AND TO A
SMALLER EXTENT THE RIO GRANDE PLAINS. OTHERWISE...THE FORECAST
REMAINS ON TRACK.
PREV DISCUSSION... /ISSUED 703 PM CDT WED APR 8 2015/
AVIATION...
THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO
TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO
DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE
FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT
PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO
MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS
WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL
LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT
LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN
ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON
THURSDAY.
PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO
SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON
INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A
FREDERICKSBURG TO LA GRANGE LINE.
FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH
OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND
SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO
NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN
BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS
ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST
CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS
IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS
AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH
CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE
HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS
SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE
REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED
ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM
FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT
SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED
INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB.
WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS
TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE
CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING
SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS
MOSTLY DRY.
FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A
WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE
DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER
MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS
PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID
AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE
CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE
NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL
FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO
SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST
FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS
POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND
WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL
WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT
MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN
IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS
AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE
REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY
AND POCKETS OF HEAVY RAIN OVER THE WEEKEND.
FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE
NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE
UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE
HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL
LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE
RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH
INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE
LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG
TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND
SOUTHERN ZONES.
FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING
SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED
IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH
INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT
LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND
SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A
LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN
SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS.
FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN
LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED
SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN
ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END
OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE
FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50
AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50
NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50
BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50
DEL RIO INTL AIRPORT 68 89 69 83 67 / 50 - 20 50 50
GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50
HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50
SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50
LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50
SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50
STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1152 PM CDT Wed Apr 8 2015
.AVIATION...
/06Z TAFS/
Showers and thunderstorms are quickly moving out of the area with
no additional activity to our west, so have removed all mention of
precipitation from TAFs. As models were showing earlier, low
clouds are not materializing, or are rapidly disappearing as they
did around KSJT, so have removed any mention of low clouds as
well. Expect this trend to hold up through the overnight hours as
we are nearing the trough axis at this point, with dry air moving
into the air aloft indicated by WV satellite imagery. VWP loops
show increasingly westerly component to low level winds, so
overall drying is expected to continue. Gusty southerly winds will
continue through the rest of the overnight hours. West to
southwest winds move in tomorrow morning. A cold front will drop
south into the KABI area by around 00Z tomorrow evening, then KSJT
and KBBD around or shortly after 03Z, but may have a hard time
making the I-10 corridor before 06Z tomorrow night.
&&
.PREV DISCUSSION... /ISSUED 942 PM CDT Wed Apr 8 2015/
DISCUSSION...
Forecast has been updated to remove Severe Thunderstorm Watch 38
from all but Haskell County. Haskell County will be removed after
this line of thunderstorms move through. Expecting wind gusts in
the 40 mph range, but will allow the storms to move through before
cancelling the watch. Have also lowered PoPs across the area
somewhat as the southern end of the line of thunderstorms
continues to decay as it moves east. 20
PREV DISCUSSION... /ISSUED 736 PM CDT Wed Apr 8 2015/
DISCUSSION...
Have updated forecast products for Severe Thunderstorm Watch 38
in effect for areas generally west of a Haskell/Abilene/Ballinger/
San Angelo line through 1 AM. Gusts over 60 mph and hail up to
the size of quarters are possible with these storms. The line
should start moving into Sterling/Irion Counties between 8 and 830
PM, and into the Nolan/Fisher County area between 830 and 9 PM.
20
PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/
AVIATION...
/00Z TAFS/
Skies have cleared, except for a blanket of mid and upper level
clouds across most of west central Texas. A weakly organized
broken band of thunderstorms is moving toward the west central
Texas area this evening. Have these storms moving across our TAF
sites roughly between 01Z(8PM) and 06Z(1AM). These storms have
brought gusts of over 40 knots to areas to our west. This is
likely due to very dry low layers of the atmosphere, and fast
movement of the storms themselves. Will carry a mention of gusty
winds to 35 knots in TEMPO groups at area sites to account for the
possibility of gusty winds. Based on most recent trends (gusts to
35-40 knots), do not expect these to bring severe strength wind
gusts of 50 knots or great at this time, but this cannot be ruled
out. For the rest of the overnight hours, models have become much
less pessimistic with respect to low clouds after 03Z(10PM)
tonight, so will go with higher, but still MVFR (2500 feet) CIGS
at most sites tonight beginning around 06Z(1AM). Winds will remain
south to southeasterly and gusty through most of the overnight.
Winds will shift to the west tomorrow between 12Z(7AM) and
15Z(10AM). 20
PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/
SHORT TERM...
(Tonight and Tomorrow)
Initial shortwave has worked itself off to the east and has taken
the first round of mainly elevated convection with it. A little more
potent shortwave is approaching for late this afternoon and this
evening. At the surface, a fairly diffuse dryline extends across the
Permian Basin northward into the Panhandle. Much sharper feature to
the north where the high clouds have thinned enough to allow much
better mixing and a more defined dryline.
Morning soundings showed a substantial cap to overcome for surface
based convection, and the abundant high clouds limiting sunshine and
heating has so far not weakened the cap enough. However, as the
shortwave approaches, should see the cap finally weaken enough to
see at least scattered convection develop from the Permian Basin
north into the South Plains, with the activity spreading into West
Central Texas by sunset. How much convection we see is still a
question, with the HRRR showing a fairly extensive area of storms
while the TTU WRF shows quite a bit less. Given the shear and at
least some instability, if storms can develop and get organized,
they certainly have the potential to reach severe levels. And given
a 50 kt low level jet developing during the evening, storms may be
slow to dissipate through the evening and into the early morning
hours.
Pacific front shifts east into West Central Texas on Thursday,
although perhaps not quite clearing the eastern sections by
afternoon. May have enough moisture still in place for a few storms
to redevelop across areas of a Brownwood to Junction line.
LONG TERM...
(Thursday Night through Wednesday)
Rain chances will continue Thursday night over southern sections
of the forecast where the frontal boundary will be located. The
frontal boundary will continue to provide a focus of thunderstorm
activity Friday and into the weekend as low level winds return to
south and southeasterly allowing isentropic upglide across over
the area. The best chance of additional rainfall will be over the
southern half of the area. Winds aloft will become southwesterly
ahead of an upper level low that will move across the northern
Baja Peninsula Saturday night. Periodic disturbances in the flow
aloft will keep the chance of thunderstorms over the area through
Sunday night. Rain chances will decrease over most of the CWA
from west to east on Monday as the Pacific upper low lifts
northeast from extreme western Texas to the Central Plains.
Residual thunderstorms will still be possible over primarily the
southern CWA through Wednesday as a southwestern flow aloft
reestablishes ahead of another upper level low digging southeast
from the Pacific Northwest to the Central Rockies.
Post-frontal afternoon temperatures on Friday will be in the
lower 70s across the forecast area after Friday morning lows in
50s. Given the continuation of rainfall chances and good cloud
cover through the middle of next week, warm-up will be gradual
with upper 70s for Saturday highs, upper 70s and lower 80s on
Sunday and Monday, and lower 80s for highs on Tuesday and
Wednesday. Morning lows will climb back into the upper 50s to the
lower 60s into the middle of next week.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 86 55 73 60 / 20 5 10 20 40
San Angelo 66 87 57 73 61 / 10 10 10 40 40
Junction 66 85 62 75 62 / 20 20 20 40 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
206 AM EDT THU APR 9 2015
.SYNOPSIS...
A BACK DOOR COOL FRONT OVER NORTHEAST VIRGINIA WILL CONTINUE TO EASE
SOUTHWEST ACROSS THE PIEDMONT OVERNIGHT. THE BOUNDARY WILL THEN
LIFT BACK TO THE NORTH THURSDAY AHEAD OF A STRONGER COLD FRONT
APPROACHING FROM THE WEST. THIS FRONT WILL PUSH THROUGH FROM THE
WEST FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 200 AM EDT THURSDAY...
NEAR TERM UPDATES TO SHOW HIGHER POPS WITH SHOWERS AND
THUNDERSTORMS LIKELY FARTHER EAST ALL THE WAY INTO PIEDMONT WITH
THIS CURRENT WAVE OF CONVECTION. THUNDER MAY DIMINISH AS IT MOVES
WELL OVER THE WEDGE ENTRENCHED OVER THE NORTHEAST PART OF THE AREA
BUT NOT SURE IT WILL ENTIRELY SO LEFT THUNDER IN ALL THE WAY EAST
THROUGH ABOUT 5 AM. LOWERED MINS IN NORTHEAST BASED ON CURRENT
TEMPS OF UPPER 40S JUST TO THE NORTHEAST OF OUR AREA IN CENTRAL
VA.
PREV DISC AS OF 855 PM EDT WEDNESDAY...
WEDNESDAY AFTERNOON CONVECTION HAS MOVED SOUTHEAST OUT OF THE
FORECAST AREA. A WEAK HIGH PRESSURE CENTER WILL PROVIDE US WITH
A SHORT BREAK IN THE ROUNDS OF CONVECTION THIS EVENING. ANOTHER
AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED IN OHIO AND
KENTUCKY. THIS CONVECTION WILL CONTINUE TO MOVE EASTWARD AND
ROTATE ACROSS OUR REGION TONIGHT INTO THURSDAY MORNING. THE TIMING
OF THIS CONVECTION APPEARS A LITTLE FASTER THAN HIRES MODELS
SUGGEST. THE BETTER INSTABILITY WILL OCCUR UNTIL AROUND 02Z...THEN
THE INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF
STORMS APPROACH. LEANED THE POPS TOWARDS A HRRR AND RAP BLEND
BECAUSE OF THE WARM ADVECTION SHOWERS NOTED ON WSR-88D IMAGES
ACROSS WEST VIRGINIA.
IN ADDITION TO THE SHOWERS AND THUNDERSTORMS...HIGH PRESSURE WILL
CONTINUE TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS
EVENING INTO TONIGHT...AND WILL OVERSPREAD THE MOST OF THE AREA BY
DAWN. RAINFALL FROM THIS EVENING AND TONIGHT STORMS WILL MOISTEN
THE LOW LEVELS OF THE ATMOSPHERE AND CREATE THE LOWER CLOUDS
EXPECTED OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO
THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE
DAY.
INITIALLY SHAPED TEMPERATURES THIS EVENING INTO TONIGHT TOWARDS
LAMP. THEN WITH THE RICH CLOUD COVER...OVERNIGHT TEMPERATURES
WILL REMAIN MILD WITH READINGS FROM THE LOWER 50S IN THE MOUNTAINS
TO THE UPPER 50S IN THE SOUTH. HIGHS ON THURSDAY WILL RANGE FROM
THE UPPER 60S IN THE NORTH TO THE UPPER 70S IN THE SOUTH.
AS OF 600 PM EDT TUESDAY...
MADE SOME ADJUSTMENTS IN POPS AND WEATHER FOR THIS EVENING INTO
TONIGHT...SHAPING TOWARDS WSR-88D RADAR TRENDS AND LATEST HRRR
SOLUTION. ADJUSTED TEMPERATURES FOR THIS EVENING INTO TONIGHT.
AS OF 415 PM EDT TUESDAY...
KEEPING OUR EYES ON A SERIES OF DISTURBANCES STRETCHING FROM
VIRGINIA TO THE MISSISSIPPI RIVER THIS AFTERNOON...ALL TRIGGERING
THUNDERSTORM ACTIVITY AND ALL PROGGED TO RIDE A STATIONARY FRONT
EASTWARD THROUGH THE EVENING AND OVERNIGHT.
THE FIRST LINE OF THUNDERSTORMS IS WEAKENING AS IT ENCOUNTERS THE
DOWNSLOPE FLOW IN THE VICINITY OF INTERSTATE 64. EXPECT LOCALLY
GUSTY WINDS AND POCKETS OF HEAVY RAIN AS THE LINE CROSSES
MOUNTAINS...BUT BELIEVE SEVERE THUNDERSTORM ACTIVITY WILL BE
ISOLATED AT BEST...IF AT ALL. FURTHER WEST...THUNDERSTORM ACTIVITY
DEVELOPING ACROSS CENTRAL KENTUCKY IS EXPECTED TO ENTER OUR MOUNTAIN
EMPIRE COUNTIES AFTER SUNSET...AND CONVECTION DEVELOPING OVER
SOUTHERN ILLINOIS IS EXPECTED TO APPROACH OUR WESTERN RIDGES BEFORE
DAWN THURSDAY. INSTABILITY WILL DECREASE AS THE SECOND AND THIRD
ROUND OF STORMS APPROACH...SO BELIEVE THE THREAT FOR SEVERE STORMS
THIS EVENING AND TONIGHT REMAINS REMOTE.
IN ADDITION TO STORMS...HIGH PRESSURE CONTINUES TO BUILD IN ACROSS
THE PIEDMONT FROM THE NORTHEAST THIS AFTERNOON...AND WILL OVERSPREAD
THE MOST OF THE AREA BY DAWN. BELIEVE THAT RAINFALL ENTERING THE
AREA THIS EVENING AND TONIGHT WILL MOISTEN THE LOW LEVELS OF THE
ATMOSPHERE AND HELP TO STRENGTHEN THE HIGH PRESSURE AS IT BUILDS
IN...WHICH WILL MAKE FOR WIDESPREAD CLOUD COVER OVERNIGHT. HIGH
PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED
INTO PLACE THROUGH MUCH OF THE DAY.
CLOUDS WILL MAINTAIN MILD TEMPERATURES THROUGH THE NIGHT...HOLDING
OVERNIGHT LOWS IN THE MID AND UPPER 50S. WILL STICK TO THE COOL SIDE
OF GUIDANCE FOR HIGH TEMPERATURES ON THURSDAY...HOLDING HIGHS IN THE
LOW AND MID 70S FOR MUCH OF THE AREA. BELIEVE THAT TEMPERATURES WILL
REMAIN COOL THROUGH MID AFTERNOON DUE TO THE MORE WIDESPREAD NATURE
OF THE CLOUD COVER...AND THEN SEE A LATE DAY UPWARD SPIKE IN
TEMPERATURES AS CLOUDS BEGIN TO BREAK UP DURING MAX AFTERNOON
HEATING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
STRONG SHORT WAVE OVER THE UPPER MID WEST WILL MOVE EAST THURSDAY
NIGHT AND FRIDAY. THURSDAY NIGHT THE SURFACE LOW MOVES NORTHEAST
ACROSS THE GREAT LAKES...THEN ON FRIDAY TRACKS INTO SOUTHERN
ONTARIO. ANY REMNANTS OF THE SURFACE WEDGE AND MORE STABLE AIR MASS
IN THE NORTHEAST COUNTY WARNING AREA WILL BE GONE ON THURSDAY
EVENING.
TIMING HAS BEEN CONSISTENT IN THE MODELS BRINGING THE ASSOCIATED
COLD FRONT THROUGH A BULK OF THE COUNTY WARNING AREA ON FRIDAY.
MODELS WERE FORECASTING BEST INSTABILITY AHEAD OF THE FRONT IN THE
PIEDMONT ALONG THE EASTERN EDGE OF THE FORECAST AREA ON FRIDAY
AFTERNOON...WITH CAPES OF AS HIGH AS 2000 J/KG POSSIBLE. WILL
MAINTAIN MENTION OF SEVERE WEATHER THREAT IN THE HAZARDOUS WEATHER
OUTLOOK.
12Z MODELS WERE VERY SIMILAR WITH THE TIMING OF THE FRONT ON FRIDAY.
WILL MAKE SLIGHT ADJUSTMENTS TO THE LOCATION BETWEEN 18Z/2PM FRIDAY
AND 00Z SATURDAY/8PM FRIDAY WITH A HIGHER PROBABILITY OF RAIN. MORE
CHALLENGING TO TELL HOW MUCH COVERAGE OF SHOWERS AND THUNDERSTORMS
THERE WILL BE AHEAD OF THE FRONT THURSDAY NIGHT. HAVE ALSO REMOVED
THE RAIN BEHIND THE FRONT FOR LATE FRIDAY NIGHT AND SATURDAY.
WILL BE TRENDING TOWARD WARMER GUIDANCE AHEAD OF THE FRONT FOR LOWS
ON THURSDAY NIGHT. WILL BE STARTING MILD ON FRIDAY BUT LIMITED
HEATING DURING THE MORNING OVER THE MOUNTAINS WHICH WILL HOLD
TEMPERATURES IN THE 60S. IN THE EAST WHERE THE FRONT COMES THROUGH
LATER...TEMPERATURES WILL RISE WELL INTO THE 70S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...
SECOND PIECE OF ENERGY COMES THROUGH THE NORTHEASTERN TROF ON
SATURDAY SO THE 500 MB LONG WAVE TROF DOES NOT MOVE EAST OF THE
FORECAST AREA UNTIL SUNDAY MORNING. THEN PATTERN RETURNS TO RIDGING
IN THE EAST AND TROFING THE WEST FOR THE REST OF THE PERIOD. HEIGHTS
AT 500 MB BECOME MORE AMPLIFIED BY MONDAY AND TUESDAY. WITH A DEEP
CLOSED LOW IN THE WEST MONDAY THROUGH WEDNESDAY...FORECAST AREA WILL
BE IN BROAD SOUTHWEST FLOW WITH A SERIES OF SHORT WAVES TRACKING OUT
OF THE SOUTHERN PLAINS. AT THE SURFACE A SECONDARY FRONT CROSSES
THE NORTHEAST SATURDAY NIGHT BUT LOOKS FAIRLY WEAK BY THE TIME IT
REACHES THE CENTRAL APPALACHIANS. WPC CONSIDERED NORTH AMERICAN AND
GFS ENSEMBLES AS REASONABLE FOR THE UPPER AND SURFACE TIMING AND
LOCATION OF FEATURES FOR THIS TIME FRAME.
HIGH PRESSURE BUILDS IN FOLLOWING THE FRONT AND WILL BE CENTERED
OVER THE FORECAST AREA ON SUNDAY MORNING. THE HIGH WILL BE OFFSHORE
BY MONDAY AFTERNOON. WARM...MOIST AIR WILL BE IN PLACE ON TUESDAY
AND WEDNESDAY. APPEARS THERE WILL BE NO ORGANIZED LIFTING MECHANISM
TO GENERATE PRECIPITATION BUT ANY DECENT SHORT WAVE SHOULD BE ABLE
TO TRIGGER AT LEAST AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
AFTER TEMPERATURES DROP BEHIND THE FRONT ON FRIDAY...850 MB VALUES
REBOUND MONDAY THROUGH WEDNESDAY. MODELS HOLD RESIDUAL LOW LEVEL
MOISTURE IN THE WESTERN UPSLOPE AREAS THROUGH SATURDAY MORNING.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 205 AM EDT THURSDAY...
DEALING WITH ANOTHER WAVE OF SHWRS AND THUNDERSTORMS MOVING
THROUGH OVERNIGHT ACROSS THE NORTHERN HALF OF THE AREA...ALTHOUGH
A FEW SHWRS MAY GET DOWN TO DANVILLE AFTER 08 UTC. WEDGE FRONT
DOWN INTO NORTHERN NC AND INTO NEW RIVER VALLEY AREA AS
WELL...WITH IFR CONDITIONS AT LYH...AND BEHIND THIS WAVE OF SHWRS
AND STORMS SHOULD LOWER TO IFR AT ROA...BCB...AND EVENTUALLY DAN.
MAY BE TOO AGGRESSIVE WITH THIS IN CURRENT TAFS BUT CONFIDENCE
HIGH WE`LL SEE IFR BEFORE DAWN AT ALL THESE AIRPORTS. KEPT IT MVFR
AT LWB AND BLF BUT LOWER CONF THERE. COULD REMAIN VFR AT BLF WITH
OCCASSIONAL SHOWERS OR STRAY TSTORM OVERNIGHT.
HIGH PRESSURE IS EXPECTED TO MAINTAIN ITS HOLD ON THURSDAY...WITH
LOW CEILINGS LINGERING ACROSS MUCH OF THE AREA INTO MID AFTERNOON.
WITH BETTER INSTABILITY ALONG THE CONTINENTAL DIVIDE WHERE HIGH
PRESSURE HAS LESS INFLUENCE...MAY SEE A FEW SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOP BY LATE AFTERNOON IN MAXIMUM HEATING.
EXTENDED AVIATION DISCUSSION...
PROLONGED PERIOD OF MVFR CONDITIONS LOOKS IN ORDER INTO FRIDAY
WITH A COLD FRONTAL PASSAGE EXPECTED LATER FRIDAY. COLD FRONT
EXPECTED TO CLEAR THE REGION FRIDAY NIGHT-SATURDAY MORNING WITH
ANY SHOWERS SUBSIDING...THOUGH SOME UPSLOPE MVFR CEILINGS MAY
LINGER INTO SATURDAY AT KBLF/KLWB. WIDESPREAD VFR THEN RETURNS
SATURDAY NIGHT AND SUNDAY UNDER HIGH PRESSURE BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...KK/NF/SK
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...KK/NF/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
336 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU APR 9 2015
SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER
LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE
PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS
CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB
MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST
MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF
WISCONSIN INTO SOUTHERN MICHIGAN.
FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT
IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY
12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA
WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND
CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH
IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION
TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS
EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW.
NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN
AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN
THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z
TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE
FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS
MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST
UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST
AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF
1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK
THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR
IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE
THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL
TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN
MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST
WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING
WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME
SOUTHERN MOST FORECAST AREA.
FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE
SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED
SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER
DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF
PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE
LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC
BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE
09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND
CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER
WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH
POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS
EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2
INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN.
HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING
ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND
TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU APR 9 2015
AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO
CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW
MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT
SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW
SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND
EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT
EXIST.
SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT
LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES
ACROSS THE AREA.
NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY
INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL
RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH
THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES...
THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON
LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO
THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE
REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON
THIS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1100 PM CDT WED APR 8 2015
CIGS...
NOT A LOT OF CHANGE EXPECTED THROUGH THU NIGHT WITH MOST
CIGS HOVERING AROUND OR BELOW 1 KFT. VARIOUS BOUTS OF SHRA/TS WILL
KEEP CIGS LOWS...AS WILL POOLED MOISTURE UNDER A STRONG LOW LEVEL
INVERSION.
WINDS...
WINDS WILL GO FROM EAST TO NORTH NORTH/NORTHWEST THU
AFTERNOON AS AN AREA OF LOW PRESSURE SLIDES JUST SOUTH OF THE TAF
SITES. INCREASING PRESSURE GRADIENT ON THE NORTHWEST SIDE OF THE LOW
SHOULD RESULT IN AN INCREASE IN SUSTAINED WINDS - ALONG WITH THE
POTENTIAL FOR HIGHER GUSTS - THU NIGHT.
WX/VSBY...
BANDS OF SHOWERS WILL SWEEP ACROSS THE REGION TONIGHT
INTO THU NIGHT. THERE WILL LIKELY BE SEVERAL HOUR BREAKS BETWEEN
THEM...BUT TRYING TO FERRET OUT EXACT TIMING IS PROBLEMATIC...SO
WON/T GET THAT REFINED IN THE FORECAST.
FOR THUNDER CHANCES...BUFKIT SOUNDINGS SHOW MEAGER INSTABILITY A
LOFT...AND INTERESTINGLY MOST OF IT IS ABOVE THE SATURATED LAYER.
THAT SAID...A FEW STORMS HAVE DEVELOPED AND APPROACHED KRST/KLSE.
HAD TO UPDATE PREVIOUS TAFS TO INCLUDE MENTION FOR A FEW HOURS PAST
06Z. RUC GRADUALLY SINKS THE ELEVATED INSTABILITY SOUTHWARD
OVERNIGHT. COULD BE ISOLATED THUNDER THU INTO THU NIGHT...BUT
CONFIDENCE TOO LOW TO INCLUDE IN FORECAST AT THIS TIME.
ALSO OF NOTE IN THE BUFKIT SOUNDINGS IS THE SOMEWHAT SHALLOW NATURE
OF A LOT OF THE SATURATION. IN MANY WAYS ITS MORE SUGGESTIVE OF A
HEAVY DRIZZLE RATHER THAN SHRA/RA TYPE EVENT. HAVE NOTED DRIZZLE
ALREADY THIS EVENING...BEFORE SHOWERS MOVED IN. THU AFTERNOON SEEMS
TO FAVOR DRIZZLE TOO.
VSBYS WILL BE RESTRICTED IN THE HEAVIER PCPN...ESPECIALLY IF HEAVY
DRIZZLE MANIFESTS. SOME FOG SHOULD HELP LOWER VSBYS OVERNIGHT INTO
THU MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
858 AM EDT THU APR 9 2015
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE ACROSS THE AREA WILL MOVE OFF TO THE
EAST BY TONIGHT. LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES
REGION AND CAUSE A WARM FRONT TO CROSS OUR AREA FRIDAY. A COLD FRONT
WILL FOLLOW FOR FRIDAY NIGHT. MORE HIGH PRESSURE WILL BUILD IN FOR
THE WEEKEND AND REMAIN INTO MONDAY. ANOTHER LOW AND SERIES OF FRONTS
WILL AFFECT THE WEATHER NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT TOO MANY CHANGES WITH THIS UPDATE. WE ADDED SOME PATCHY
MORNING DRIZZLE MAINLY IN NJ BASED ON OBS AND RADAR RETURNS. WE
USED LATEST HRRR AND RAP TRENDS TO LOWER POPS THROUGH THE MID DAY
FOR THE REMNANT PCPN SOUTH AND OTHER PCPN TRYING TO ARRIVE FROM
THE WEST. AGREE WITH MID SHIFT TEMPS ARE GOING NOWHERE TODAY.
A FRONTAL BOUNDARY WAS LOCATED FROM THE WESTERN SIDE OF THE CENTRAL
APPALACHIANS BACK DOWN INTO THE CAROLINAS EARLY THIS MORNING.
MEANWHILE, HIGH PRESSURE LOCATED OVER EASTERN CANADA CONTINUES TO
RIDGE SOUTHWARD INTO THE NORTHEAST AND MID-ATLANTIC STATES. WITH
THIS CAD PATTERN ON THE EASTERN SIDE OF THE APPALACHIANS HOLDING
STRONG, EXPECT TODAY TO BE PRETTY MUCH A REPEAT OF YESTERDAY:
CLOUDY AND COOL BUT SLIGHTLY LESS WET AND WINDY.
THE ONE CONCERN EARLY THIS MORNING IS SPOTTY FREEZING DRIZZLE AND
FREEZING FOG AT HIGHER ELEVATIONS IN THE POCONOS. BASED ON LATEST
MESONET OBSERVATIONS, TEMPS ARE MARGINALLY FREEZING (31-32F) ABOVE
1500 FT. ISSUED AN SPS FOR THESE AREAS TO COVER THE POSSIBILITY OF
LIGHT ICING ON ELEVATED SURFACES. EXPECT LITTLE IMPACTS THOUGH WITH
PAVEMENT TEMPERATURES REMAINING ABOVE FREEZING.
REMNANTS FROM A DECAYING MCS THAT IS CURRENTLY OVER VA WILL MOVE
EASTWARD EARLY THIS MORNING. THIS WILL BRING A PERIOD OF SHOWERS TO
THE DELMARVA AND POSSIBLY AS FAR SOUTHERN NJ BETWEEN 4-9 AM.
OTHERWISE, COVERAGE OF RAIN EXPECTED TO BE MINIMAL FOR THE REST OF
THE DAY WITH ORGANIZED LIFT AND INSTABILITY STILL WELL TO OUR WEST.
BASED ON VERIFICATION OF TEMPS YESTERDAY AND LAST NIGHT, FELT IT WAS
PRUDENT TO GO COLDER THAN STAT GUIDANCE FOR TEMPS TODAY. WE FAVORED
THE RAW OUTPUT FROM THE NCEP WRF ARW/NMM, WHICH GIVES US HIGHS IN
THE 40S (15-20F BELOW NORMAL).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
SOUTHWESTERLY FLOW WILL STRENGTHEN ALOFT AS LOW PRESSURE DEEPENS
OVER THE GREAT LAKES. THIS WILL ADVECT WARMER AIR ALOFT INTO THE
REGION BUT THE SHALLOW LAYER OF COLD AIR TRAPPED IN THE LOWEST 1000
FT OF THE ATMOSPHERE WILL PREVENT THE WARM FRONT FROM MAKING IT INTO
OUR AREA. THEREFORE, CLOUDY, COOL AND DAMP CONDITIONS WILL PERSIST
INTO TONIGHT.
FORECAST SOUNDINGS APPEAR A BIT MORE FAVORABLE FOR DRIZZLE TONIGHT
THAT IT DID LAST NIGHT WITH ISENTROPIC LIFT AND MOISTURE ADVECTION
ABOVE THE CAD WEDGE. WE WILL NEED TO KEEP AN EYE OUT ON POTENTIAL
MCS DEVELOPMENT UPSTREAM THIS AFTERNOON OVER THE MIDWEST. THE
REMNANTS OF THIS SYSTEM COULD BRING A ROUND OR TWO OF SHOWERS TO OUR
REGION TONIGHT. THE WARM NOSE AROUND 900 MB STRENGTHENS LATE AND THE
00Z NAM BUFKIT SOUNDINGS FORECASTS SEVERAL HUNDRED J/KG OF ELEVATED
INSTABILITY TO DEVELOP OVER OUR AREA TOWARD EARLY MORNING. OPTED TO
NOT PUT IN ANY MENTION OF THUNDER AS THERE IS A LITTLE BIT OF CIN
FOR PARCELS TO OVERCOME, WHICH MAY INHIBIT CONVECTION GIVEN A LACK
OF SIGNIFICANT LIFT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY/FRI NIGHT...THE RECENT ONSHORE FLOW OF COLD AND MOIST AIR
WILL DIMINISH AS A COLD FRONT APPROACHES FROM THE WEST. IF THE LOW
CLOUDS DIMINISH FAST ENOUGH...IT COULD END UP BECOMING VERY WARM
AND HUMID. SHOWERS/TSTMS ARE EXPECTED LATE AFTERNOON AND EARLY
EARLY OVERNIGHT AS A COLD FRONT APPROACHES. THE SRN HALF OF OUR
CWA IS IN A SLIGHT RISK FOR SVR WEATHER FRIDAY.
SAT THRU MONDAY...MOSTLY FAIR WITH SEASONABLE TEMPERATURES. HIGH
PRESSURE BUILDS IN SAT...CRESTS OVER THE AREA SUN AND THEN MOVES
EAST MONDAY. HIGH TEMPS MOSTLY IN THE 60S SAT/SUN AND CLOSER TO 70
MON.
TUE THRU WED...ANOTHER LOW PRESSURE SYSTEM FROM THE PLAINS HEADS
TOWARD THE UPPER GREAT LAKES. ITS ASSOCIATED FRONTS APPROACH THE
AREA. WE WENT ALONG WITH THE WPC POPS FOR THESE PERIODS WITH
MOSTLY CHC POPS. TEMPERATURES WILL BE A LITTLE ABOVE NORMAL FOR
MID APRIL.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE REGION REMAINS SOCKED IN LOW CLOUDS AND BR EARLY THIS MORNING.
FLIGHT RESTRICTIONS MOSTLY FROM CIGS THAT ARE IN IFR RANGE. SIMILAR
TO YESTERDAY, EXPECT SOME IMPROVEMENT TO MVFR DURING THE DAY WITH
CIGS BETWEEN 1 AND 2 KFT AGL. THIS GRADUAL IMPROVEMENT WILL LIKELY
OCCUR AT THE TERMINALS FROM NE TO SW BETWEEN 14Z AND 18Z. ONSHORE
FLOW WILL LIKELY KEEP ACY AND POSSIBLY MIV IN IFR ALL DAY.
CIGS LOWER AGAIN TONIGHT, BECOMING IFR LATE THIS EVE AND POSSIBLY
LIFR OVERNIGHT. PERIODS OF RA, DZ AND FOG WILL LIKELY CAUSE VSBY
RESTRICTIONS.
THERE IS STILL SOME UNCERTAINTY WITH THE TIMING OF THE EXPECTED CIG
IMPROVEMENT TODAY AND DETERIORATION TONIGHT SO FUTURE TAF UPDATES
WILL PROVIDE REFINEMENT.
NORTHEAST WINDS AROUND 10 KT THIS MORNING WILL VEER OUT OF THE EAST
MIDDAY AND EVENTUALLY SOUTHEAST BY LATE TONIGHT.
OUTLOOK...
FRIDAY/FRIDAY NIGHT...A TRANSITIONAL DAY WITH THE LOW CLOUDS
DEPARTING AND THEN SCT SHOWERS AND TSTMS DEVELOPING. MVFR/IFR WITH
THE LOW CLOUDS EARLY AND THEN AGAIN LATE IN ANY TSTM.
SAT THRU MONDAY NIGHT...MOSTLY VFR.
&&
.MARINE...
SCA IN EFFECT FOR OUR ATLANTIC COASTAL WATERS TODAY AND TONIGHT.
THERE ARE STILL A FEW GUSTS IN THE 25 KT RANGE ALONG THE NJ COAST
EARLY THIS MORNING BUT OVERALL ONSHORE WINDS SHOULD GRADUALLY WEAKEN
DURING THE DAY TODAY. THE MORE WIDESPREAD HAZARD ON THE WATERS WILL
BE THE SEAS WITH WAVES BETWEEN 5 AND 8 FT THRU TONIGHT.
OUTLOOK...
FRI/FRI NIGHT...SCA CONDITIONS WITH SCT SHOWERS AND TSTMS.
SAT...SCA CONDITIONS EARLY THEN SUB-SCA WINDS/SEAS.
SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS EXPECTED.
MONDAY...SCA CONDITIONS POSSIBLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
922 AM EDT THU APR 9 2015
.DISCUSSION...LTST WV IMAGERY ALONG WITH SOUNDING DATA FROM XMR
CONFIRM AN UNFAVORABLE ENVIRONMENT EXISTS FOR DEVELOPMENT OF PCPN
TODAY. E-SE WINDS FROM THE SFC THROUGH 10KFT...COUPLED WITH E-
NE/INCREASINGLY ANTICYCLONIC MID LEVEL FLOW...WILL CONTINUE TO DRAW
IN LOWER PWAT AIR. LTST HRRR GUID SHOWS A FEW ECHOES LIKELY ASCD
WITH INLAND PROGRESSION OF MARINE CU LINES AND THE POSSIBILITY OF
SOME LOW TOPPED SPRINKLES MOVING ASHORE MAINLY FROM THE TREASURE CST
SWD. NO MEASURABLE RAINFALL IS ANTICIPATED FROM THIS ACTIVITY. THE
CURRENT FORECAST IS IN GOOD SHAPE.
&&
.AVIATION...VFR CONDS. SOME SCT BASES NR FL 040 REMAIN PSBL IN CU
LINES ALONG THE CST AND SOMEWHAT INLAND THROUGH THE AFTN.
&&
.MARINE...(PREVIOUS DISC) HIGH PRESSURE REMAINS IN FIRM CONTROL OF
LCL WX. ESE-SE WINDS 10-15KT WITH SEAS 3FT NEAR SHORE AND 4FT AWAY
FROM THE COAST.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
JP/FJ
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1007 AM CDT Thu Apr 9 2015
.UPDATE...
ISSUED AT 1007 AM CDT THU APR 9 2015
15z/10am surface analysis shows 1000mb low centered just north of
Kansas City, with warm front extending eastward into northern
Illinois. Front has now lifted north of the KILX CWA, placing the
entire area firmly in the warm sector. Widespread early morning
convection is in the process of exiting into northern Indiana,
leaving behind just scattered showers/storms for the time being.
Further upstream, the next upper-level impulse is triggering a
renewed round of convection across western Missouri. Based on
timing tools and the latest HRRR guidance, this activity will move
into the SW CWA between 17z and 18z. Once this wave departs,
attention will turn to the approaching cold front which is still
on target for a late afternoon/early evening arrival. Airmass
ahead of the front will become moderately unstable and highly
sheared, so threat for strong to severe thunderstorms is still
present. Current indications suggest the primary time frame will
be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the
main threat with the storms, although large hail and isolated
tornadoes will also be possible as the cells first begin to
develop. Made some changes to hourly PoPs to better reflect
current and expected trends, but changes were minor and did not
require a full zone update at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 303 AM CDT THU APR 9 2015
Latest surface analysis shows the warm front has lifted to the I-74
corridor early this morning with a chaotic wind field across most of
the forecast area. Not sure what the affect the current scattered
convection will have on the position of the frontal boundary thru
the morning hours, but most of the models suggest a continued slow
push to the north as the main surface low tracks northeast to
central Iowa by late this morning. Current thinking is that the cold
front will be positioned just west of the Mississippi River by 21z
with surface based convection developing ahead of the front at that
time as well. Better low level helicity fields supportive of
discrete supercells and possible tornadoes looks to be closer to the
track of the surface low...which by late afternoon is expected to be
in far southwest Wisconsin or northwest Illinois. That would put the
threat for more persistent low level rotating storms just to our
west and north. However, still plenty of shear ahead of the frontal
boundary this afternoon and early this evening to promote damaging
straight line winds as the storms transition into more of a linear
system. Temperature-wise, with the warm front to our north this
afternoon, will continue to go with the warmer guid values most
areas. Latest model data now suggests the backedge of the precip
pushes out of our far southeast counties by midnight, so will extend
the Flash Flood Watch until that time this evening.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 303 AM CDT THU APR 9 2015
Showers and thunderstorms, possibly severe, will be ongoing across
at least the eastern half of the forecast area to start this
evening. Despite the short forecast range, there is still some
spread in the expected cold frontal timing. However, it appears
reasonable that the front will lie somewhere between the Illinois
River and the I-55 corridor by 00Z Friday. Sped up the decrease in
shower/storm chances by mid evening, and I would not be surprised to
see the precipitation chances taper off a few hours earlier,
especially if the squall line gets a head of steam and trends
further ahead of the front than current progs.
Once the front clears the area tonight, quiet conditions, along with
much cooler and less humid air will build across the region into
Sunday. These conditions will be driven by a large area of high
pressure of Canadian origin. While conditions will be notably
cooler/less humid, they will still be at or above normal for early
April.
The next precipitation chances will arrive later Sunday into Sunday
night as a cold front is dragged across the area. While this front
is still expected to stall out at it begins to parallel the
upper-level flow, model trends suggest the front will stall out
further south than previously anticipated. If these trends persist,
Monday and Monday night will end up dry. For now, have reduced but
not eliminated PoPs Monday/Monday night until we see if this recent
model trend sticks.
A slow moving upper-level disturbance will push the front back into
the area by Tuesday, bringing renewed shower/storm chances. The
front and/or upper level disturbances will keep the rain chances
going into the end of the work week. Temperatures should remain at
or above normal through the period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 640 AM CDT THU APR 9 2015
Active weather day across the region with scattered thunderstorms
this morning, with storms expected to redevelop this afternoon and
evening along a cold front. Some of those storms will be severe
with damaging wind gusts and hail possible. VFR cigs expected
outside any storms, however, with any strong storm, look for cigs
and vsbys to briefly drop to IFR at times. Gradient winds are
expected to be rather gusty today out of the south and southwest
with prevailing speeds of 15 to 25 kts with gusts around 35 kts
at times. Cold front timing looks to be around the PIA site by 23z
and should be east of our TAF sites by 02z. It appears the strongest
storms will be about an hour or two ahead of the actual cold front
this afternoon and evening.
Look for sfc winds to become southwest with FROPA and with the storm
system expected to deepen, a rather tight pressure gradient will
produce a period of strong and gusty winds out of the southwest
just after the passage of the cold front late this afternoon into
the evening. Some gusts may be around 35 kts at times just after
the front shifts to the east of a TAF sites early this evening.
Expect the strong gusts to slowly subside, but not until after
03z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063-
066>068-071>073.
&&
$$
UPDATE...Barnes
SHORT TERM...Smith
LONG TERM...Bak
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS JACKSON KY
945 AM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 945 AM EDT THU APR 9 2015
INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS
AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED
THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE
AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL
HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO
HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD
GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB
SERVERS AND NDFD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 411 AM EDT THU APR 9 2015
EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS
AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE
NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN
RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL
BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME
ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE
TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO.
HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND
NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE
ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO
MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY
THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY
TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND
DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE
VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS
AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE
OR THE OTHER.
THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z
FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS
WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE
WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND
CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO
APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS
LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL
RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES
EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD
FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z
FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z.
JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL
TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF
TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS
WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE
WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL
WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND
RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING
NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN
THE MID AND UPPER 60S.
MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS.
IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY
RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON.
MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL
ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD
AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED
IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO
HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 534 AM EDT THU APR 9 2015
THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW
PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT
WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE
PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE
DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE.
A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND
TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR
SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO
THE 30S FOR THE MORE SHELTERED VALLEYS.
A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO
SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A
SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT
OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL
USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH
PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL
BOUNDARY.
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL
INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED
SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON
THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL
FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH
LOWS IN THE LOW TO MID 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 656 AM EDT THU APR 9 2015
STRONG SRLY FLOW AND MOIST UNSTABLE AIR WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION TODAY...ESPECIALLY DURING
THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE
THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH
VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE
WIDESPREAD CHANCES VERY LATE IN THE PERIOD...AFFECTING
KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z...THEN KJKL AND
KSJS AROUND 6Z OR AFTER. ONCE AGAIN...UNTIL STORMS DEVELOP...EXACT
IMPACTS ARE STILL UNCERTAIN...SO WENT WITH A GENERAL MVFR AT THIS
TIME. WITH ANY OF THESE STORMS...ESPECIALLY IN THE AFTERNOON AND
EVENING...STRONG TO DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINS
ARE A POSSIBILITY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1147 AM EDT THU APR 9 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 AM EDT THU APR 9 2015
A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY
AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL
SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE
TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED.
SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS
EVENING...ESPECIALLY FURTHER SOUTH.
A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE
RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY.
COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE.
CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT
CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 1145 AM EDT THU APR 9 2015
THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE
SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND
LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4
PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE
NORTH OF THE WARM FRONT.
WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING
IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR
NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY
SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND
TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST
PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD.
HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR
INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME
THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE
SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS
FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO
THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN
GENERAL.
INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT
THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS
THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED
REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER.
THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST
ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE.
THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE
CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL
MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL
SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE
NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA
UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE
WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS
MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE
SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER
WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA.
WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE
AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED
INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH
AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE
WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS
OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG
FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER
SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY
DOWN SOUTH.
WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF
OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE
POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP
HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS
POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR
THE WARM FRONT IN THE AREA.
STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT.
THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI.
THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI
MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT
SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP
AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN
DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES
THROUGH. THIS SHOULD NOT BE SIGNIFICANT.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN
NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO
BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE
NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT
FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY
AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY.
THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC
CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF
AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE
PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE
WEATHER.
THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN
STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD
BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS
SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING
THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY.
SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD
EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER
THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A
TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY
RAIN TUESDAY.
FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT
UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM
THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO.
WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES
SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER
WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES
EAST BRING INCREASED SOUTHERLY WINDS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 753 AM EDT THU APR 9 2015
FOR THE MOST PART EXPECT PERIODS OF THUNDERSTORMS INTO THIS
EVENING. LOW CLOUDS WITH IFR / MVFR CIGS WILL ALSO PREVAIL MOST OF
THE DAY. THE WARM FRONT WILL STRUGGLE TO REACH I-94 BY LATE
AFTERNOON. IF THE WARM FRONT DOES IN FACT REACH I-94 CEILINGS MAY
BECOME VFR FOR A FEW HOURS. THE STRONGEST STORMS SHOULD BE THIS
EVENING JUST AHEAD OF THE COLD FRONT.
ONCE THE COLD FRONT COMES THROUGH WINDS WILL TURN TO THE SOUTHWEST
AND INCREASE TO 20 TO 30 KNOTS. CIGS WILL REMAIN MVFR THROUGH
SUNRISE FRIDAY. SHOWERS ARE POSSIBLE IN THE COLD UNSTABLE AIR
BEHIND THE COLD FRONT.
&&
.MARINE...
ISSUED AT 330 AM EDT THU APR 9 2015
WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR
OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP
SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT
TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN.
WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO
FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE
GRADIENT RELAXES.
&&
.HYDROLOGY...
ISSUED AT 111 PM EDT WED APR 8 2015
RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING
NEAR TO A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY STEADY OR
SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD
RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE
IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF
THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL ROUNDS
OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TONIGHT INTO FRIDAY. URBAN
AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE...
THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING
FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
627 AM CDT THU APR 9 2015
.UPDATE...
ISSUED AT 627 AM CDT THU APR 9 2015
UPDATED FOR AVIATION DISCUSSION.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD
THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS
SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY
WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA
THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI
ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH
CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE
AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN
ALL LIQUID.
THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST
AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW
WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON
THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME
PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT
ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF
ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST
SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN.
HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A
POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM
IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO
FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS
AND HAVE REMOVED.
TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE
AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE
PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND
THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE
AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST
TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL
FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST
POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT
ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW
PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME
ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED.
ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE
UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE
MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO
REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY
MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS
WITH DIURNAL HEATING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS
WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND
INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE
TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL
DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL
EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE
NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND
POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE
FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE
BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE
NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION
BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE
BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS
IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF
OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE.
RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY
NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE
30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR
IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL
KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL
SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 627 AM CDT THU APR 9 2015
LOW END MVFR AND IFR CEILINGS WILL PERSIST THROUGH TODAY...WITH
SCATTERED LIFR CIGS ACROSS THE NRN TERMINALS THIS MORNING. RAIN
SHOWERS...WITH EMBEDDED FZDZ/IP/SN WILL MOVE IN FROM THE SOUTH
THIS MORNING AND SPREAD TO THE ENE THROUGH THE AFTERNOON. THE HYR
TERMINAL WILL SEE THE MOST PRECIPITATION TODAY AND TONIGHT WITH
MAINLY RAIN THROUGH THE DAY AND A CHANGE OVER TO ALL SNOW THIS
EVENING AND TONIGHT. CONDITIONS WILL IMPROVE TO VFR FROM THE NW
TONIGHT...WITH A BRIEF PERIOD OF IFR/MVFR VSBYS IN LIGHT FOG
BEHIND THE FRONT. NE WINDS WILL CONTINUE MOST OF TODAY WITH A
SHIFT TO THE NW TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 32 48 30 / 70 20 20 10
INL 50 30 48 28 / 10 40 10 0
BRD 49 31 51 29 / 60 20 20 10
HYR 42 31 47 27 / 90 80 30 10
ASX 38 31 45 29 / 100 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
916 AM MDT THU APR 9 2015
.UPDATE...
MADE SOME MINOR TWEAKS FOR THE WEAK ECHOS ACROSS GLASGOW/S
AREA...BUT KEPT POPS NO HIGHER THAN 14 GIVEN THAT THE HRRR DOES
NOT HANG ON TO PRECIP VERY LONG. REIMER
&&
.SHORT TERM...VALID FOR TDY AND FRI...
WEAK NORTHERLY FLOW ALOFT WILL TAKE OVER TODAY AS THE SYSTEM THAT
IMPACTED THE SOUTHEAST MOVES AWAY. LIGHT WINDS THIS MORNING COULD
ALLOW FOR FOG FORMATION...SO WILL LET THAT PART OF THE FORECAST
RIDE FOR THE EARLY PART OF THE DAY. WEAK CIRCULATION OVER NORTHERN
IDAHO WILL SWING ACROSS THE SOUTHWEST MOUNTAINS THIS AFTERNOON AND
EVENING. ENOUGH LINGERING MOISTURE AND WEAK INSTABILITY FOR A FEW
SHOWERS OVER THE HIGHER TERRAIN DURING THE PERIOD. THE MAIN PART
OF THE TROUGH HOUSING THE WEAK ENERGY OF TODAY IS PROGGED TO PUSH
ACROSS THE AREA FRIDAY. ENOUGH WEAK INSTABILITY TO MENTION SHOWER
CHANCES OVER THE WEST. LOW LEVEL DOWNSLOPE FLOW WILL ALLOW FOR
WARMER TEMPERATURES FRIDAY AFTERNOON. TWH
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
GENERALLY FEW CHANGES TO THE EXTENDED FORECAST PERIOD...WITH
GREATEST CONCERN THROUGH THE PERIOD CONTINUING TO BE IMPRESSIVE
UPPER LEVEL LOW PRESSURE SYSTEM PROGGED TO MOVE ACROSS THE REGION
THROUGH THE LATTER HALF OF NEXT WEEK...AT LEAST.
UNTIL THEN...THE PATTERN REMAINS SOMEWHAT UNSETTLED AND
PROGRESSIVE. THE PERIOD BEGINS WITH A SHORTWAVE AND ASSOCIATED
COLD FRONT CROSSING THE REGION SATURDAY EVENING/NIGHT. SATURDAY
CONTINUES TO LOOK LIKE THE WARMEST DAY OF THE PERIOD...IN PREFRONTAL
ENVIRONMENT...WITH TEMPS AROUND 70. EXPECT TO SEE SCATTERED
SHOWERS ALONG THE FRONT...BUT NOTHING INDICATING WIDESPREAD PRECIP.
DRY WITH GUSTY NORTHWEST WINDS WILL FOLLOW BEHIND THE SYSTEM FOR
SUNDAY. WILL NEED TO KEEP A CLOSE EYE ON THESE DAYS FOR ANY FIRE
WEATHER CONCERNS. WINDS WILL BE STRONG AND GUSTY AT TIMES AND
RH VALUES LOOK LIKE WILL BE BACK IN TEENS.
DRY CONDITIONS PERSIST THROUGH MONDAY AND INTO TUESDAY...AS
SOUTHWEST FLOW SETS UP AHEAD OF APPROACHING TROF...DEVELOPING
ALONG THE WEST COAST. THERE ARE A FEW DIFFERENCES IN THE
MODELS...WITH ECMWF BRINGING A WAVE INTO THE REGION ON TUESDAY
AHEAD OF THE MAIN TROF...WHILE GFS REMAINS DRY. HAVE KEPT SLIGHT
POPS IN PLACE THROUGH THIS PERIOD...ALTHOUGH MAY MAINLY SERVE TO
RECHARGE ATMOSPHERE AFTER FEW DAYS OF DRYING OUT. MODEL COME BACK
TOGETHER A BIT BETTER BY TUESDAY NIGHT...WITH LARGE UPPER LEVEL
LOW PRESSURE SYSTEM MOVING INTO THE REGION. TRACK...SPEED...PRECIP
AMOUNTS ARE STILL UNCERTAIN...BUT MODELS HAVE BEEN VERY
CONSISTENT WITH THIS SYSTEM TRACKING ACROSS THE REGION THROUGH
THE END OF THE WORK WEEK...SO HAVE KEPT HIGH POPS IN PLACE
THROUGH THE PERIOD. TEMPS ARE ALSO UNCERTAIN DUE TO POTENTIAL
CHANGES IN TRACK OF THE SYSTEM...SO WILL HAVE TO BE MONITORED
CLOSELY. AAG
&&
.AVIATION...
VFR CONDITIONS SHOULD PREVAIL TODAY AT ALL TERMINALS. THE THREAT
OF FOG OVER THE EASTERN TERMINALS HAS DIMINISHED. LATER TODAY
THERE IS A SLIGHT CHANCE OF A MOUNTAIN SNOW SHOWER...SO MOUNTAIN
OBSCURATION RULES MAY APPLY. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 057 036/065 040/069 040/061 033/064 039/060 038/052
0/B 01/B 02/W 31/N 11/B 33/W 45/W
LVM 055 033/061 037/063 034/056 030/059 035/058 034/049
1/B 13/W 03/W 31/N 12/W 33/W 55/W
HDN 059 031/067 035/071 038/062 031/066 036/065 034/053
0/B 01/B 02/W 31/N 11/B 33/W 45/W
MLS 057 032/065 037/070 039/061 032/065 038/065 038/053
1/B 00/U 02/W 31/N 11/B 22/W 45/W
4BQ 053 029/064 035/070 038/060 031/066 037/067 036/054
0/B 00/B 01/U 31/B 11/B 32/W 45/W
BHK 053 028/062 033/068 037/059 030/064 036/067 035/056
1/B 00/U 01/U 21/N 11/B 22/W 45/W
SHR 052 027/061 033/066 036/058 031/064 035/064 034/051
0/B 00/B 01/B 31/B 11/B 33/W 45/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
619 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU APR 9 2015
TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD
HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE
PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO
SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC
OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB
TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C
ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL
DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF
NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF
RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN
THE SANDHILLS.
THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE
UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD
MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING
CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT
THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE
NORTHWEST AT THE SAME TIME.
THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER
40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY
EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB
WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH.
HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES
FOR LOWS IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU APR 9 2015
RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY
WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH
PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK
ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY
EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E
GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE
LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY
SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL
NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR
ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS
WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS.
WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO
EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP
THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE
DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING
FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY
FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE
RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN
PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF
MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT
CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY
AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA.
BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL
LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE
NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH
THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE
TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS
TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE
OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE
WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE
GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT
INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT
SPREAD EAST ONTO THE PLAINS.
TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR
ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD
COOL TEMPERATURES BACK BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 618 AM CDT THU APR 9 2015
IFR CIGS AND VSBY IN RASN COVERING WRN AND NCNTL NEB ARE EXPECTED
TO IMPROVE MARKEDLY AS EARLY AS 18Z WITH VFR/MVFR CIGS SPREADING
EAST THROUGH THE FCST AREA THIS AFTN. VFR IS EXPECTED ALL AREAS
FROM 00Z ONWARD THIS EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
958 AM EDT THU APR 9 2015
.SYNOPSIS...
A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND
RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE
SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE
NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF
THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1000 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY
OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN WILL DRIFT SLOWLY
NORTH THIS AFTERNOON AND EVENING. WILL HOLD TO LIKELY POPS THROUGH
NOON ACRS SE SECTIONS. NONE OF THE MODELS IS REALLY HANDLING THIS
PRECIPITATION WELL BUT IT STILL LOOKS LIKE A LULL IN THE EARLY
AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO EARLY EVENING THE
HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG CONVECTION
REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT BY THE
LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING THIS TIME.
SOME STORMS COULD BE ON THE STRONG SIDE LATE AFTN/EVE.
WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE AND WILL
LIKELY LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH
AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND
LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER
BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE
LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH. MADE SOME
ADJUSTMENTS TO INIT T/TD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE
AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING
THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY
CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM
SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG
DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO
BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS.
THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE
60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS
TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY
FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT
WITH PREVIOUS FCST REST OF PERIOD.
MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL
MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND
UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN
FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO
SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING
AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL
EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING
EVENING HOURS...AND OVERNIGHT ALONG COAST.
SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY
MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY
AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH
MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL
EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO
SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY
CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH
SUNDAY NIGHT.
MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO
INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC
RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT
INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING
ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING
TUE NIGHT AND CONTINUING WED.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 10 AM THURSDAY...MAIN CHANGE WAS TO REMOVE IFR CIGS FROM OAJ
AND HAVE TSRA IN FCST UNTIL ABT 16Z. WIDESPREAD LIFR/IFR
CONDITIONS WILL PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING
HOURS ACCORDING TO THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH
LAMP MOS. IFR CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT
RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE
ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG
THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY
EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED
BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS
BELOW NORMAL AT THIS TIME.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF
SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF
SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC
TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND
EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE
REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY
EVENING THROUGH MONDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...MAIN CHANGE TO INCREASE SEAS TO 5 FT ACRS
THE NRN AND CNTRL CSTL WATERS THROUGH EARLY AFTN. DENSE FOG
ADVISORY CONTS FOR THE WATERS THIS MORNING. THE FOG SHOULD
DISSIPATE WITH SUSTAINED HEATING LATE THIS MORNING. BACK DOOR COLD
FRONT HAS MOVED THROUGH THE NORTHERN AND CENTRAL WATERS INCLUDING
THE SOUNDS AND IS STALLING AS FORECAST OVER THE SOUTHERN WATERS
EARLY THIS MORNING. WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE
FRONT. LATER TODAY WINDS GRADUALLY RETURN TO THE S-SW AS FRONT
RETREATS BACK NORTH. TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT
LATE. SEAS 2 TO 4 FT TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST.
TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE
SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR
OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH
CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT
MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT
EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND
GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY.
BLEND OF PREVIOUS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS
BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND
THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS
WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131-
135>137-150-152-154-156-158.
&&
$$
SYNOPSIS...JME
NEAR TERM...JAC/JME
SHORT TERM...JME
LONG TERM...JBM
AVIATION...JAC/JME/JBM
MARINE...JAC/JME/JBM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 AM EDT THU APR 9 2015
.SYNOPSIS...
A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND
RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE
SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE
NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF
THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 700 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY
OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN AND APPEARS TO HAVE
STALLED AS FORECAST. THE FRONT WILL THEN DRIFT SLOWLY NORTH THIS
AFTERNOON AND EVENING. CONVECTION CURRENTLY OVER THE COASTAL PLAIN
IS INCREASING IN COVERAGE AND INTENSITY AND WILL NEED TO INCREASE
POPS TO LIKELY FOR THE EARLY MORNING HOURS. NONE OF THE MODELS IS
REALLY HANDLING THIS PRECIPITATION WELL BUT IT STILL LOOKS LIKE A
LULL IN THE EARLY AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO
EARLY EVENING THE HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG
CONVECTION REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT
BY THE LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING
THIS TIME. ALTHOUGH WE ARE NOT OUTLOOKED BY THE SPC FOR SEVERE
STORMS IT WILL BECOME MODERATELY UNSTABLE AND GIVEN THE THERMAL
AND KINEMATIC PROFILES COMMON THIS TIME OF YEAR, STORMS COULD
BRIEFLY BECOME SEVERE WITH DAMAGING WIND GUSTS AND LARGE HAIL
POSSIBLE.
WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE TODAY AND
COULD LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH
AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND
LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER
BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE
LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE
AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING
THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY
CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM
SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG
DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO
BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS.
THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE
60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS
TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY
FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT
WITH PREVIOUS FCST REST OF PERIOD.
MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL
MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND
UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN
FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO
SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING
AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL
EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING
EVENING HOURS...AND OVERNIGHT ALONG COAST.
SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY
MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY
AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH
MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL
EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO
SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY
CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH
SUNDAY NIGHT.
MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO
INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC
RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT
INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING
ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING
TUE NIGHT AND CONTINUING WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 700 AM THURSDAY...WIDESPREAD LIFR/IFR CONDITIONS WILL
PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING HOURS ACCORDING TO
THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH LAMP MOS. IN
ADDITION TO THE FOG AND STRATUS NUMEROUS SHOWERS AND THUNDERSTORMS
WILL AFFECTING THE TAF SITES THROUGH ABOUT 14Z WITH DOWNPOURS AND
GUSTY WINDS. CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT
RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE
ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG
THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY
EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED
BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS
BELOW NORMAL AT THIS TIME.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF
SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF
SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC
TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND
EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE
REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY
EVENING THROUGH MONDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 700 AM THURSDAY...DENSE FOG INDICATED IN MARINE OBSERVATIONS
HAS PROMPTED THE ISSUANCE OF DENSE FOG ADVISORY FOR ALL OF THE
WATERS THIS MORNING. THE FOG SHOULD DISSIPATE WITH SUSTAINED
HEATING LATE THIS MORNING. BACK DOOR COLD FRONT HAS MOVED THROUGH
THE NORTHERN AND CENTRAL WATERS INCLUDING THE SOUNDS AND IS
STALLING AS FORECAST OVER THE SOUTHERN WATERS EARLY THIS MORNING.
WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE FRONT. LATER TODAY
WINDS GRADUALLY RETURN TO THE S-SW AS FRONT RETREATS BACK NORTH.
TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT LATE. SEAS 2 TO 4 FT
TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST.
TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE
SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR
OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH
CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT
MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT
EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND
GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY.
BLEND OF PREVIUOS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS
BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND
THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS
WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131-
135>137-150-152-154-156-158.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...JBM
AVIATION...JME/JBM
MARINE...JME/JBM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT THU APR 9 2015
.SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA
TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY
AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR
SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH
THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
IN FOR THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 255 AM THURSDAY...
SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING
OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR
FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY
SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING
WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE
SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY
OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG
MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND
EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH
OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150%
OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING
SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW
OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST
WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH
THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL
AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA
OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS
AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF
THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE
FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS
MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE
MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT
DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST
MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE...
WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS
EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0
C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND
WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO
SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION
COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS
CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS
VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING
THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW
TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR
TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE
PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY
WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER
DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW
VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING
HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE
TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL
STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS
SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING
RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY
DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE
BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY
LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE
TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW
HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL
LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS
TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL
WARM SECTOR. -GIH
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 325 AM THURSDAY...
MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID
LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE...
REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS
FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING
THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW
OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID
MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT
WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30
KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST
BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A
FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF
WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO
OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING
TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND
INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE
LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG
LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK...
POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY.
THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85
(WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE
FRONT MAY NOT CLEAR UNTIL LATE. -GIH
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 350 AM THURSDAY...
SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH
CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE
WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES.
HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S
SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT.
MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON
MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD
FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON
TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE
TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY...
WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S.
THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD
WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO
AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT
AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY
COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT
CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE
MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON...
WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER
AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID
TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM THURSDAY...
PRIMARY AVIATION CONCERN NEXT 24 HRS: IFR/LIFR CIGS THROUGH THE
MORNING AT RWI/RDU/GSO/INT WITH LESSER CHANCES AT FAY.
A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN
PORTIONS OF CENTRAL NC LAST EVENING HELPED DRAW A BACKDOOR COLD
FRONT SOUTHWESTWARD WELL INTO CENTRAL NC... WITH LOW CLOUDS BASED
UNDER 1000 FT AGL AND NORTHEASTERLY WINDS HAVING SPREAD INTO NRN/ERN
NC FROM VA OVERNIGHT. SCATTERED STORMS AFFECTED MOST CENTRAL NC TAF
SITES OVERNIGHT WITH SHORT-LIVED MVFR VSBYS AND HEAVY DOWNPOURS. THE
CURRENT IFR/LIFR CIGS SHOULD RISE TO MVFR BY LATE MORNING TO EARLY
AFTERNOON... THEN TO VFR BY MID AFTERNOON... WITH ANOTHER BATCH OF
SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC
DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY
WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL
FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE
TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY
OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT
OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS
AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS
ARE LIKELY DURING THE LAST 6 HOURS OF THE TAF VALID PERIOD...
PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY.
LOOKING BEYOND 12Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG
SHOULD MIX UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20
KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI
AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO
PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD
SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE
FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE
LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER
THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...RAH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1022 AM CDT THU APR 9 2015
.UPDATE...
ISSUED AT 1022 AM CDT THU APR 9 2015
LAST FEW RUNS OF THE HRRR ALONG WITH THE 4KM WRF ALL INDICATE
ISOLATED SHOWERS DEVELOPING THIS AFTERNOON SO HAVE ADDED THIS INTO
THE FORECAST. KEPT QPF AT ZERO AS ONLY EXPECTED TRACE AMOUNTS OF
MOISTURE.
OTHERWISE THE INHERITED FORECAST IN GOOD SHAPE. CU FIELD SHOULD
DEVELOP BY EARLY TO MID AFTERNOON ALONG TO AHEAD OF A SFC COLD
FRONT MOVING SOUTH THROUGH NORTH DAKOTA TODAY. WINDS STILL LOOK
BREEZY...ESPECIALLY MID TO LATE DAY WHEN WE ARE PROJECTED TO MIX
OUT TO AROUND 700MB. ANY SHOWER ACTIVITY WILL AID IN GUSTY WINDS
WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES.
UPDATE ISSUED AT 630 AM CDT THU APR 9 2015
PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A
SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY.
OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS
THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT
DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU APR 9 2015
HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW
ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY
THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP
AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS
AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH
DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE
CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH
OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT
MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE
WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE
CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER
TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS
EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS
AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM
TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT
RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW
POPCORN SHOWERS THIS AFTERNOON.
FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION
CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS
SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST.
CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS
ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT
EAST THROUGH THE EARLY MORNING.
THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH
UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A
NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH
DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE
FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH
MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF
SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z
THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z
FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE.
EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING
TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA
BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO
THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF
AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM
WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS
THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT
AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR
THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL
SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A
CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND
DISSIPATE QUICKLY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU APR 9 2015
THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE
PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN
U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW
POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE
BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS
COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO
NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE
ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW
AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND
SOLUTION.
FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT
FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER
RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER
AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE
WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL
RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE
RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF
THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN
EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME.
A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS
LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER
LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL
PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND
BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE
TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH
TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE
SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE
SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL
RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES
SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH
STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO
MONITOR.
LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE
APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT
SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON
THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE
WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE
REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM
AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL
UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD
MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S.
TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY
AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND
HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN
STORE MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 1022 AM CDT THU APR 9 2015
ALL TERMINALS WILL REMAIN VFR TODAY AND TONIGHT. A FAIRLY LARGE
BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL
NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY
NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS
AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS
DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH/NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
631 AM CDT THU APR 9 2015
.UPDATE...
ISSUED AT 630 AM CDT THU APR 9 2015
PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A
SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY.
OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS
THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT
DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU APR 9 2015
HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW
ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY
THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP
AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS
AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH
DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE
CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH
OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT
MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE
WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE
CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER
TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS
EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS
AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM
TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT
RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW
POPCORN SHOWERS THIS AFTERNOON.
FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION
CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS
SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST.
CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS
ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT
EAST THROUGH THE EARLY MORNING.
THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH
UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A
NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH
DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE
FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH
MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF
SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z
THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z
FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE.
EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING
TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA
BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO
THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF
AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM
WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS
THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT
AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR
THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL
SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A
CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND
DISSIPATE QUICKLY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU APR 9 2015
THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE
PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN
U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW
POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE
BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS
COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO
NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE
ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW
AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND
SOLUTION.
FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT
FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER
RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER
AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE
WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL
RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE
RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF
THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN
EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME.
A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS
LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER
LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL
PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND
BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE
TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH
TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE
SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE
SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL
RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES
SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH
STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO
MONITOR.
LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE
APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT
SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON
THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE
WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE
REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM
AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL
UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD
MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S.
TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY
AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND
HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN
STORE MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 630 AM CDT THU APR 9 2015
VFR CIGS WILL RETURN TO KDIK BETWEEN 12Z AND 13Z THURSDAY...AND
MAY BE IN AND OUT THROUGH 15Z WITH SOME SCATTERED IFR CEILING IN
THE NEIGHBORHOOD. THE REST OF THE TERMINALS WILL REMAIN VFR. A
FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN
AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY.
GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS
AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS
DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1016 AM EDT THU APR 9 2015
.SYNOPSIS...
ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. COLD FRONT
CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES
AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...AS WITH THE PAST SEVERAL DAYS...THE HRRR IS
BEGINNING TO LATCH ON TO YET ANOTHER CONVECTIVE COMPLEX FOR THIS
AFTERNOON. HRRR DID FAIRLY WELL THE LAST COUPLE DAYS...SO USED
THAT TO UPDATE POPS THROUGH THIS EVENING. EXPECTING A COMPLEX TO
MOVE NE ACROSS CWA...WITH THE MAIN ACTIVITY ALONG AND WEST OF THE
OHIO RIVER...AND MORE SCATTERED CONVECTION ACROSS EASTERN HALF OF
CWA.
PREVIOUS DISCUSSION...MODELS SHOWING SHOWERS AND THUNDERSTORMS
CONTINUING OVER NORTHERN WEST VIRGINIA EARLY THIS MORNING. WITH
MUCH OF THE AREA ALREADY SATURATED...FEEL THAT A FLASH FLOOD WATCH
IS PRUDENT FOR THE REMAINDER OF THE NORTHERN WV COUNTIES IN OUR
FORECAST AREA. WITH THUNDERSTORMS POSSIBLE AGAIN THIS AFTERNOON
AND EVENING AND IN ADVANCE OF THE COLD FRONT ON FRIDAY...WILL GO
AHEAD AND EXTEND THE ENTIRE FLASH FLOOD WATCH INTO FRIDAY.
BASED ON MESO MODELS SHOWING PRE-FRONTAL PRECIPITATION WITH THE
FRONTAL BOUNDARY LATE THURSDAY NIGHT...WILL SPEED UP AND INCREASE
POPS SOME.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
PREFRONTAL BAND WILL BE RACING THRU AREA EARLY FRIDAY
MORNING...FOLLOWED BY ACTUAL SURFACE FRONT. HOPEFULLY THIS
PREFRONTAL BAND WILL BE ON A WEAKENING TREND AS IT COMES THRU
GIVEN TIME OF DAY AND SEPARATION FROM BETTER DYNAMICS. STILL...A
STOUT LLJ IS WORRISOME FOR DAMAGING WIND THREAT. THERE MAY BE SOME
REJUVENATION ALONG THE ACTUAL COLD FRONT BY THE TIME IT GETS INTO
THE MOUNTAINS BY LATE MORNING OR MIDDAY. MAY SEEM SOME SUN FRIDAY
AFTERNOON AMID SOME BREEZY CONDITIONS IN THE DRY SLOT ALOFT. TRUE
CAA HOLDS OFF UNTIL SATURDAY AS THE UPPER TROF SWINGS THRU. NOT
EXPECTING ANY PRECIP JUST AN EXPANSIVE STRATOCU FIELD...MOST
NOTICEABLE ACROSS N ZONES. HIGH PRESSURE BUILDS IN SATURDAY NIGHT
AND WITH A CLEAR SKY...THINK THERE COULD BE SOME FROST CONCERNS IN
THE LOWLANDS. WE HAVE NOT STARTED THE GROWING SEASON JUST YET...BUT
SOMETHING TO KEEP IN MIND FOR THOSE EAGER GREEN THUMBS. THE HIGH
SLIDES OFF TO THE E ON SUNDAY BUT STILL A NICE DAY WITH MILD
TEMPS.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND
STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT
BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS
ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA
BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY
TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN
PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR
WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR
THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR
NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO
CONVECTION/HIGHER POPS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY
THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR
RESTRICTIONS. SOME MVFR FOG/STRATUS IS POSSIBLE EARLY THIS MORNING IN AREAS
RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY
VFR CLOUDS CAN BE EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013-
014-017-019-020.
FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018-
024>032-037>040-046-047.
OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075-
076-083>087.
KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...RPY/SL/30
NEAR TERM...RPY/MZ
SHORT TERM...30
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS PORTLAND
846 AM PDT THU APR 9 2015
.SYNOPSIS...HIGH PRESSURE OVER THE REGION WILL LEAD TO MAINLY DRY
CONDITIONS TODAY WITH PERHAPS A SPOTTY SHOWER DEVELOPING OVER THE
HIGHER CASCADE TERRAIN IN THE AFTERNOON. FRIDAY WILL LIKELY REMAIN
DRY DURING THE DAY FOR MOST OF THE REGION...BUT CLOUDS AND RAIN WILL
SPREAD INTO THE REGION DURING THE LATE AFTERNOON AND EVENING HOURS. A
COOL SHOWERY PATTERN WILL FOLLOW ON SATURDAY WITH MOST OF THE AREA
LOOKING DRY ON SUNDAY AND EARLY MONDAY. ANOTHER COOL AND WET STORM
SYSTEM LOOKS TO ARRIVE EARLY NEXT WEEK BEFORE HIGH PRESSURE BRINGS
DRIER AND WARMER WEATHER BEGINNING THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...FOG CONTINUES ALONG THE COAST AND IN THE VALLEYS THIS
MORNING AND ALTHOUGH PATCHES OF DENSE FOG REMAIN...IMPROVEMENT IN
VISIBILITY IS ALREADY BEING SEEN AT SOME AREA OBSERVATION SITES.
EXPECT VISIBILITIES TO IMPROVE ACROSS THE BOARD BY LATE MORNING. NO
MAJOR UPDATES NEEDED THIS MORNING AS THE FORECAST APPEARS TO BE ON
TRACK. TWEAKED NEAR-TERM SKY GRIDS A BIT TO ACCOUNT FOR FOG AND THEN
AFTERNOON CLEARING. THE 12Z GFS IS HINTING AT A SLIGHT CHANCE OF
SHOWERS IN THE LOWER COLUMBIA AREA THIS AFTERNOON...BUT BOTH HRRR
AND RUC KEEP ANY POPS IN THE CASCADES AND MAYBE FOOTHILLS SO WILL
KEEP POP/WX FORECAST AS IS THROUGH THIS EVENING. BOWEN
.SHORT TERM (PREVIOUS DISCUSSION)...TODAY THROUGH SUNDAY...SATELLITE
IMAGERY AND SURFACE OBSERVATIONS INDICATE A FEW PATCHES OF CLOUDS
SCATTERED ABOUT THE REGION...WITH MOST HUGGING THE CASCADE FOOTHILLS.
SOME PATCHY FOG IS BEGINNING TO DEVELOP IN THE SOUTHERN WILLAMETTE
VALLEY...AND EXPECT ADDITIONAL FOG DEVELOPMENT THIS MORNING AS THE
LOWER ATMOSPHERE STABILIZES AND SATURATES...PARTICULARLY AROUND
EUGENE...CORVALLIS...MCMINNVILLE AND HILLSBORO.
A VORT MAX AND WEAK UPPER LEVEL SHORTWAVE TROUGH WILL HANG OVER THE
COLUMBIA RIVER BASIN TODAY. THE SOUTH WASHINGTON CASCADES AND NORTH
OREGON CASCADES WILL REMAIN CLOSE ENOUGH TO THIS INSTABILITY THAT A
SPOTTY LIGHT SHOWER MAY DEVELOP LATER THIS AFTERNOON...BUT THESE
SHOULD REMAIN RATHER ISOLATED AND MORE NUISANCE IN NATURE.
OTHERWISE...MOST LOCATIONS SHOULD EXPECT MOSTLY SUNNY SKIES AND
TEMPERATURES RISING SEVERAL DEGREES ABOVE NORMAL ONCE THE FOG BURNS
OFF MID TO LATE MORNING.
FRIDAY LOOKS LARGELY DRY ACROSS THE AREA BEFORE A COLD FRONT PUSHES
RAIN INTO OUR NORTHWEST COAST DURING THE LATE AFTERNOON HOURS. RAIN
WILL LIKELY PUSH INLAND DURING THE LATE EVENING AND OVERNIGHT HOURS.
THE MAIN UPPER LEVEL SUPPORT AND DEEPER INSTABILITY WITH THIS FRONT
WILL JUST CLIP OUR NORTHERN ZONES LATE FRIDAY NIGHT INTO SATURDAY
MORNING SO THERE IS SOME CONCERN THE CURRENT QPF FORECAST MAY BE A
BIT TOO HIGH ACROSS THE SOUTHERN HALF OF THE FORECAST AREA.
SUFFICIENT INSTABILITY ON SATURDAY SHOULD LEAD TO ADDITIONAL SHOWERS
DEVELOPING OVER THE INTERIOR DURING THE AFTERNOON AND EARLY EVENING
HOURS BEFORE THE ATMOSPHERE STABILIZES AND PRECIPITATIONS CHANCES
RAPIDLY DECREASE SATURDAY NIGHT. IT APPEARS THE INSTABILITY WILL BE
SHALLOW ENOUGH THAT THUNDERSTORMS DO NOT APPEAR LIKELY ON SATURDAY
EVEN ACROSS THE FAR NORTH.
MODELS CONTINUE TO TREND TOWARDS THE IDEA THAT SUNDAY WILL END UP
LARGELY DRY ACROSS MOST OF THE FORECAST AREA SO POPS WERE NUDGED
DOWNWARD DURING THIS PERIOD...ESPECIALLY ACROSS OUR SOUTHERN ZONES.
A WEAK LOW LEVEL TROUGH MAY PUSH INTO WESTERN WASHINGTON DURING THIS
PERIOD AND BRING A FEW LIGHT RAIN SHOWERS TO EXTREME NORTHWEST
OREGON AND SOUTHWEST WASHINGTON COASTAL AND COAST RANGE ZONES SO
CHANCE POPS WERE MAINTAINED ACROSS THESE ZONES DURING THIS
PERIOD. /NEUMAN
.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...MODELS SEEM TO BE
CONVERGING ON THE IDEA THAT A LARGE SHORTWAVE TROUGH WILL SWING
EASTWARD OUT OF THE GULF OF ALASKA AND IMPACT THE PACIFIC NORTHWEST
EARLY NEXT WEEK. MAINTAINED CHANCE POPS ON MONDAY DUE TO UNCERTAINTY
IN TIMING...BUT MODELS SEEM TO BE TRENDING TOWARDS RAIN ARRIVING LATE
MONDAY. DEEP POST FRONTAL INSTABILITY...STRONG ONSHORE FLOW AND SNOW
LEVELS LOWERING INTO THE 3KFT RANGE MAY LEAD TO HIGHLIGHT WORTHY SNOW
IN THE CASCADES WITH THIS EVENT. LEFT THUNDER OUT OF THE FORECAST FOR
TUESDAY FOR NOW DUE TO THE UNCERTAINTY IN THE SYNOPTIC SCALE
PATTERN...BUT IF CONFIDENCE GROWS THE AFOREMENTIONED PATTERN WILL
COME TO FRUITION...IT WILL ALMOST CERTAINLY NEED TO BE ADDED IN
COMING SHIFTS. MODELS SEEM TO BE TRENDING TOWARDS DECENT SHORTWAVE
RIDGING BUILDING INTO THE PACIFIC NORTHWEST WEDNESDAY AND BEYOND SO
TEMPERATURES WERE NUDGED UPWARDS AND POPS AND SKY COVER WERE TRENDED
DOWN. /NEUMAN
&&
.AVIATION...HIGH PRESSURE OVER THE AREA HAS ALLOWED FOG TO DEVELOP
IN THE WILLAMETTE VALLEY AND ALONG THE COAST. FOG SHOULD LIFT TO
LOW STRATUS IMPROVING VIS BY AROUND 16-17Z. CONDITIONS SHOULD IMPROVE
TO VFR BY 18-20Z. WINDS HAVE TURNED OFFSHORE ALONG THE
COAST...WHICH WILL HELP CLEAR THESE SITES TO VFR BY 18Z AS WELL.
VFR CONDITIONS TO PERSIST THIS AFTERNOON. WE MAY SEE SOME VALLEY
FOG DEVELOP TONIGHT INLAND...BUT THIS SHOULD CLEAR OUT EARLY
TOMORROW MORNING AS WINDS START TO INCREASE OUT OF THE SOUTH AHEAD
OF OUR NEXT FRONT WHICH MOVES THROUGH TOMORROW EVENING.
KPDX AND APPROACHES...IFR/LIFR CONDITIONS THIS MORNING SHOULD
START TO IMPROVE AS FOG LIFTS TO LOW STRATUS BY 16Z. STRATUS
SHOULD BURN OFF RAPIDLY...FURTHER IMPROVING CONDITIONS TO VFR BY
18Z. -MCCOY
&&
.MARINE...HIGH PRESSURE OVER THE REGION IS KEEPING SEAS DOWN
AROUND 3 FT WITH WIND BELOW 10 KTS TODAY. FRONTAL SYSTEM
APPROACHING THE WATERS WILL BACK WINDS TO THE SOUTHWEST BY FRIDAY
MORNING AND START TO RAMP UP WINDS AND BUILD SEAS THROUGH THE DAY
FRIDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR WINDS
AND SEAS ON FRIDAY AFTERNOON...AS WINDS ARE EXPECTED TO PEAK AHEAD
OF THE FRONT IN THE AFTERNOON/EVENING HOURS AROUND 20 TO 25 KTS
WITH GUSTS TO 30 KTS. WINDS STAY UP AROUND 15 TO 25 KTS BEHIND THE
FRONT...FINALLY STARTING TO DECREASE SATURDAY EVENING. SEAS WITH
THIS SYSTEM BUILD TO AROUND 10 TO 12 FT FRIDAY AFTERNOON/EVENING
AS WELL...AND FALL TO AROUND 8 TO 10 FT BY SATURDAY MORNING. THE
TIME PERIOD WITH SEAS BELOW 10 FT WILL LIKELY ONLY LAST UNTIL
SATURDAY EVENING...AND SEAS IN THE OUTER WATERS MAY NEVER DROP
BELOW 10 FT. A 10 TO 11 FT SWELL TRAIN MOVES INTO THE
WATERS SATURDAY EVENING...BRINGING SEAS UP ABOVE 10 FT THROUGH AT
LEAST MONDAY MORNING. ANOTHER FRONT IS EXPECTED TO MOVE THROUGH
SOMETIME EARLY NEXT WEEK. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 AM EDT THU APR 9 2015
.SYNOPSIS...
STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE
CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS
OVER THE REGION TODAY. LOW PRESSURE WILL MOVE THROUGH THE GREAT
LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS
PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME
BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN
MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND
SOUTH. WIDESPREAD LOW CLOUDS AND RIDGE SHROUDING FOG WILL PERSIST
THIS MORNING...BEFORE SLOWLY LIFTING AS SFC TEMPS MODERATE A BIT
THIS AFTERNOON. SHOWERS OVER WESTERN PA MAY SNEAK INTO OUR FAR
WESTERN LAYER OF COUNTIES BEFORE DIMINISHING IN THE INCREASINGLY
STABLE AIRMASS.
LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN
STRONGLY DAMMED. HOWEVER...SHOWERS FORMING IN THE UNSTABLE AIRMASS
OVER THE OHIO VALLEY ARE MADE TO SURVIVE THE TREK INTO CENTRAL PA
LATER THIS AFTERNOON AND THIS EVENING AS THE HRRR SHOWS AN
EROSION OF THE WESTERN EDGE OF THE STABLE COOL-AIR-DAMMING.
CAN`T RULE OUT LATE DAY-EARLY EVENING SEVERE THREAT OVER WESTERN
PORTIONS OF THE SOMERSET/WARREN COUNTIES ON THE EDGE OF THE
INSTABILITY NEAR OUR STATIONARY BOUNDARY.
HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG
AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CLUSTERS/BKN LINE OF STRONG TO POTENTIALLY SEVERE TSRA ACROSS THE
OHIO VALLEY THIS AFTERNOON/EVENING WILL HEAD INTO INCREASINGLY
STABLE LLVL CONDITIONS ACROSS CENTRAL AND ERN PENN AND GRADUALLY
WEAKEN TONIGHT. STILL...A LARGE AREA AND NEARLY OFF THE
CHART/ANOMALOUSLY STRONG /PLUS 5-6 SIGMA/ 850 MB MOISTURE FLUX
/SHOWN ON THE 00Z GEFS AND 03Z SREF/ WILL SLIDE NORTHEAST ACROSS
MUCH OF CENTRAL AND NWRN PENN. THIS WILL LEAD TO AREAS OF
MODERATE...TO BRIEFLY HEAVY SHRA /THOUGH MAINLY LIMITED TO THE NW
HALF OF PENN/.
12 TO 24 HOUR RAINFALL TONIGHT THROUGH FRIDAY /AS DEPICTED BY
OPERATIONAL MODELS AND ENSEMBLES/ OF JUST 0.25-0.50 OF AN INCH
ACROSS MAINLY THE NW HALF OF PENN WILL BE SURPRISINGLY LIGHT GIVEN
SUCH STRONG LLVL MOISTURE FLUX. HOWEVER...THE KEY TO THE LIGHTER
THAN EXPECTED QPF APPEARS TO BE LINKED TO THE LACK OF FAVORABLE
JET DYNAMICS/LIFT AS THE RIGHT EXIT REGION OF A 100 KT UPPER JET
SLIDES NE ACROSS LAKE ERIE AND NW PENN LATE TONIGHT AND FRIDAY
MORNING.
SPC GREATLY TRIMMED BACK THEIR DAY 1 CONVECTIVE OUTLOOK AREA
PREVIOUS ERN EXTENT OF THE SLIGHT RISK AND ENHANCED THREAT AREAS OVER
WESTERN PENN HAVE BEEN PULLED BACK WELL INTO CENTRAL AND WESTERN
OHIO. ERN EDGE OF THE MARGINAL THREAT AREA NIPS OUR FAR WESTERN
ZONES FOR THIS EVENING AND TONIGHT.
APPROX 990 MB SFC LOW OVER THE UPPER GLAKES AT 12 FRIDAY WILL PUSH
ITS SWD TRAILING COLD FRONT THROUGH CENTRAL PENN DURING THE LATE
MORNING AND AFTERNOON HOURS FRIDAY. THE TIMING OF THIS CFROPA
FAVORS ANY CHC OF STRONG TO POTENTIALLY ISOLATED SVR TSRA BEING
LIMITED TO PRIMARILY THE MIDDLE AND LOWER SUSQ VALLEY AFTER 18Z
FRIDAY. SPC MARGINAL AND SLIGHT RISK AREAS FOR DAY 2 COVER THE SE
THIRD OF THE CWA.
TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S ACROSS
THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE /WHERE THE 03Z
SREF SHOWS ABOUT A 30-40 PERCENT PROBABILITY OF CAPE EXCEEDING
1000 J/KG/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA
FOR LATE FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR CONDITIONS
ACROSS THE REGION THIS MORNING. THERE COULD BE SOME SLOW
IMPROVEMENT THIS AFTERNOON...BUT ALL TERMINALS WILL MAINTAIN
CEILINGS IN THE 500-1500` RANGE AT BEST. JOHNSTOWN MAY STAND THE
BEST CHANCE OF BRIEFLY GOING VFR BEING CLOSE TO THE WARM FRONT
STACKED UP OVER THE ALLEGHENIES...BUT CONFIDENCE IN SIG
IMPROVEMENT IS NOT HIGH.
WIDESPREAD IFR/MVFR WILL CONTINUE OVERNIGHT UNTIL THE COLD FRONT
PASSES DURING THE DAY FRIDAY.
LLWS IS POSSIBLE BEHIND THE LINE WITH WITH SFC WINDS REMAINING
OUT OF THE SOUTHEAST...AND WINDS BETWEEN 1500 TO 2KFT AT 40KTS
POSSIBLE TONIGHT BEGINNING IN THE WEST AROUND 07Z TO 11Z AT LNS.
OUTLOOK...
FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
SAT-MON...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
645 AM CDT THU APR 9 2015
.AVIATION...
ACTIVE WEATHER CONTINUES ACROSS THE CENTRAL PART OF THE CONUS IN
ASSOCIATION WITH AN UPPER LEVEL TROUGH CURRENTLY TRAVERSING THE
CENTRAL PLAINS. NORTH TEXAS RESIDES ON THE SOUTHERN EXTENT OF THE
LIFT ASSOCIATED WITH THE SYSTEM...WHICH WHEN COMBINED WITH THE
STRONG LOW LEVEL JET IN PLACE...HAS RESULTED IN ELEVATED
CONVECTION ACROSS PARTS OF THE AREA. THE EAST-WEST AXIS OF STORMS
HAS SHIFTED TO BETWEEN THE DALLAS-FORT WORTH METROPLEX AND
KACT...AND WILL LIKELY PERSIST IN THIS REGION UNTIL THE LOW LEVEL
JET MIXES OUT MID MORNING.
ADDITIONAL THUNDERSTORMS WILL BECOME LIKELY THIS AFTERNOON AS A
COLD FRONT SURGES SOUTH INTO NORTH TEXAS. THE FRONT WILL BE REACHING
THE METROPLEX DURING PEAK HEATING HOURS LATE THIS AFTERNOON...WITH SCATTERED
THUNDERSTORMS DEVELOPING IN THE VICINITY OF THE BOUNDARY. STORMS
SHOULD INITIALLY BE SCATTERED IN NATURE IN AND AROUND THE
METROPLEX BEFORE EVOLVING INTO A SQUALL LINE AS THE FRONT PUSHES
FARTHER SOUTH AND EAST ACROSS THE WACO AREA THIS EVENING. THE
LATEST MODEL GUIDANCE SUGGESTS FROPA IN THE METROPLEX AROUND
00-02Z THEN IN THE WACO AREA 04-06Z. FOR NOW...WE WILL MAINTAIN
VCTS IN AREA TAFS BUT LATER FORECASTS MAY REQUIRE THE ADDITION OF
A TEMPO GROUP FOR THUNDER DEPENDING ON FUTURE TRENDS. ACTIVITY
SHOULD SHIFT SOUTH AND EAST OF ALL TAF LOCATIONS AROUND 10/O6Z
ALONG WITH THE FRONT.
30
&&
.UPDATE...
A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS
MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS.
THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF
THE I-20 CORRIDOR THIS MORNING.
58
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/
A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A
GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL
CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE.
AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST
DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS
FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE
OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME
OF THIS ACTIVITY THROUGH DAYBREAK.
THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS
AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE
HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR
OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z.
WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE
LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL
AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID
TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO
2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR
VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE
WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND
DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW
TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM
HELICITY VALUES APPROACHING 200 M2/S2.
EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND
SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL
BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE
PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE
FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN
WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH
30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE.
THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING
IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY
NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT
THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL
MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40
WACO, TX 84 58 73 58 76 / 40 60 20 30 40
PARIS, TX 79 51 73 52 73 / 40 70 10 30 40
DENTON, TX 83 53 73 54 73 / 30 30 10 30 40
MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40
DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40
TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40
CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40
TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40
MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
601 AM CDT THU APR 9 2015
.UPDATE...
A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS
MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS.
THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF
THE I-20 CORRIDOR THIS MORNING.
58
&&
.AVIATION...
A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS THIS MORNING ACROSS
CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS. THIS ACTIVITY
WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20
CORRIDOR.
/ISSUED 1149 PM CDT WED APR 8 2015/
/06Z TAFS/
SOME MVFR CIGS ARE ALREADY LOCATED AROUND THE AREA BUT MVFR CIGS
ARE EXPECTED TO SPREAD OVER ALL THE TAF SITES BY 09-10Z. GUSTY
WINDS ARE OCCURRING DUE TO DISSIPATING RAIN AND STORMS IN THE
AREA AND THE WINDS OVERNIGHT ARE EXPECTED TO PREVAIL 15-20 KTS
WITH GUSTS UP TO 30 KTS. SOME ADDITIONAL THUNDERSTORMS ARE STILL
POSSIBLE OVERNIGHT AND WILL MAINTAIN A VCTS MENTION IN THE
METROPLEX BETWEEN 09-12Z. CIGS WILL IMPROVE ABOVE 2 KFT BY MIDDAY
THURSDAY AND THEN INTO VFR CATEGORY BY MID-LATE AFTERNOON. ANOTHER
ROUND OF THUNDERSTORMS IS EXPECTED AS A COLD FRONT MOVES ACROSS
THE AREA. THUNDERSTORMS WILL BE POSSIBLE IN THE METROPLEX AHEAD OF
THE FRONT FROM 09/21-10/02Z AND AT KACT BETWEEN 10/03-07Z. THESE
STORMS COULD BE STRONG OR SEVERE WITH A LARGE HAIL AND/OR DAMAGING
WIND THREAT. THE WINDS WILL SHIFT TO THE NORTH THURSDAY EVENING
AS THE FRONT MOVES THROUGH.
JLDUNN
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/
A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A
GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL
CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE.
AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST
DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS
FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE
OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME
OF THIS ACTIVITY THROUGH DAYBREAK.
THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS
AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE
HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR
OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z.
WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE
LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL
AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID
TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO
2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR
VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE
WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND
DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW
TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM
HELICITY VALUES APPROACHING 200 M2/S2.
EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND
SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL
BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE
PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE
FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN
WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH
30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE.
THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING
IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY
NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT
THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL
MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40
WACO, TX 84 58 73 58 76 / 40 60 20 30 40
PARIS, TX 79 51 73 52 73 / 40 70 10 30 40
DENTON, TX 83 53 73 54 73 / 30 30 10 30 40
MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40
DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40
TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40
CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40
TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40
MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
703 AM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU APR 9 2015
SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER
LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE
PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS
CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB
MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST
MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF
WISCONSIN INTO SOUTHERN MICHIGAN.
FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT
IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY
12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA
WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND
CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH
IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION
TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS
EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW.
NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN
AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN
THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z
TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE
FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS
MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST
UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST
AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF
1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK
THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR
IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE
THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL
TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN
MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST
WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING
WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME
SOUTHERN MOST FORECAST AREA.
FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE
SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED
SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER
DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF
PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE
LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC
BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE
09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND
CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER
WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH
POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS
EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2
INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN.
HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING
ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND
TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU APR 9 2015
AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO
CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW
MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT
SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW
SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND
EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT
EXIST.
SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT
LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES
ACROSS THE AREA.
NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY
INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL
RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH
THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES...
THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON
LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO
THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE
REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON
THIS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 703 AM CDT THU APR 9 2015
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
AREA TODAY. THE BEST CHANCES FOR THUNDERSTORMS AT THE TAF SITES
LOOKS TO BE FROM 09.13Z AND 09.15Z. ADDITIONAL THUNDERSTORMS MAY
BE POSSIBLE THIS AFTERNOON...BUT TIMING IS UNCERTAIN...SO IT WAS
NOT INCLUDED IN THE TAFS. CEILINGS THROUGHOUT THE TIME PERIOD WILL
BE MAINLY LIFR/IFR AT KRST AND IFR/MVFR AT KRST. VISIBILITIES
THROUGH 10.06Z WILL BE ANYWHERE FROM 1 TO 3 MILES AT KRST AND
MVFR/VFR AT KLSE. THROUGH TODAY THE NORTHEAST WINDS WILL REMAIN AT
10 KNOTS OR LESS AND THEN SWITCH TO THE WEST THIS EVENING AND
CLIMB TO AROUND 20 KNOTS WITH WINDS GUSTING INTO THE 30 TO 35 KNOT
RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS ALBANY NY
151 PM EDT THU APR 9 2015
.SYNOPSIS...
A WARM FRONT WILL BEGIN TO MOVE NORTH OF THE OHIO VALLEY AND THE
MID ATLANTIC REGION TODAY INTO TONIGHT. THIS WILL KEEP THE CLOUDS
ALONG WITH SOME LIGHT RAIN SHOWERS AND DRIZZLE TODAY WITH A
STEADIER RAINFALL EXPECTED TONIGHT. A MILDER AIR MASS WILL BE
ACROSS THE REGION BY FRIDAY AS THE WARM FRONT MOVES THROUGH...AND
A COLD FRONT WILL BRING SHOWERS AND A SLIGHT CHANCE FOR
THUNDERSTORMS LATE FRIDAY MORNING AND INTO THE AFTERNOON HOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 130 PM EDT...THE PATCHY DRIZZLE AND FREEZING DRIZZLE HAS
DIMINISHED ACROSS THE FCST AREA. IT IS STILL A VERY COOL AND DAMP
AIR MASS WITH TEMPS RUNNING ABOUT 15 T0 20 DEGREES BELOW NORMAL.
SOME PATCHY DRIZZLE WAS KEPT IN THE FCST AREA WRN NEW ENGLAND AND
THE SRN DACKS IN THE MID TO LATE PM. THE SPS FOR SPOTTY FREEZING
DRIZZLE ESPECIALLY OVER THE HIGHER TERRAIN WILL END AT 2 PM.
A WARM FRONT WILL BEGIN LIFTING N/NE FROM OH AND THE MID ATLANTIC
REGION LATE THIS AFTERNOON INTO TONIGHT. MAX TEMPS WILL GENERALLY
BE IN THE 30S TO L40S FOR THE REST OF THE DAY...AND STEADY OF
SLOWLY RISE INTO TONIGHT. THE LATEST HRRR HAS THE NEXT BATCH OF
PCPN MOVING IN BETWEEN 00Z-03Z WITH THE SHORT-WAVE IN THE SW FLOW
AND THE STRENGTHENING WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...THE WARM FRONT QUICKLY LIFTS N/NE FROM THE LOWER GREAT
LAKES REGION AND PA ACROSS UPSTATE NY AND NEW ENGLAND AS THE
CENTER OF LOW PRESSURE TRACKS FROM THE MID MISSISSIPPI RIVER
VALLEY INTO THE CENTRAL GREAT LAKES REGION. THIS STORM WILL
INTENSIFY OVERNIGHT AS THE UPPER TROUGH BECOMES NEUTRAL TO
NEGATIVELY TILTED. EXPECT PERIODS OF RAIN AS MOIST LOW LEVEL JET
INCREASES WITH DEEP ISENTROPIC LIFT. THERE MAY BE A RUMBLE OF
THUNDER AROUND WEST AND SOUTH OF ALBANY AS THE SHOWALTER VALUES
FALLING CLOSE TO 0C TO -1C. LOWS THU NIGHT WILL RANGE FROM THE
U30S TO L40S ACROSS MOST THE REGION. SOME MELTING OF THE SNOW
PACK...ESPECIALLY OVER THE HIGHER TERRAIN IS EXPECTED. TOTAL RAIN
AMOUNTS LATE THU PM INTO FRI MORNING WILL BE IN THE QUARTER TO
THREE QUARTERS INCH RANGE WITH THE HIGHER TALLIES OVER THE SRN
DACKS.
FRIDAY...COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THE
MORNING AND INTO THE MID AFTERNOON HOURS. SHOWALTER VALUES DROP
ACROSS THE REMAINDER OF THE REGION TO VALUES AROUND 0C. THIS ALONG
WITH COLLABORATION WITH SPC...WE WILL CONTINUE WITH THE MENTION OF
THUNDER IN THE FORECAST/GRIDS. HIGHS IN THE LOWER AND M60S IN
MOST OF THE VALLEY AREAS /A FEW U60S OVER THE MID HUDSON
VALLEY/...AND M50S TO L60S OVER THE HILLS AND MTNS.
FRIDAY NIGHT...COLD ADVECTION OCCURS IN THE WAKE OF THE FRONT
WITH PRETTY GOOD SUBSIDENCE TO END MOST OF THE PCPN FOR THE FCST
AREA...THOUGH A FEW UPSLOPE RAIN TO SNOW SHOWERS ARE POSSIBLE OVER
THE WRN DACKS. LOWS WILL BE IN THE M30S TO L40S IN MOST LOCATIONS
WITH A FEW U20S TO L30S OVER THE SRN DACKS.
SATURDAY...THE MAIN UPPER TROUGH AXIS AND SECONDARY COLD FRONT
WILL CROSS THE REGION. THE BEST MOISTURE PROFILES AND FAVORABLE
UPSLOPE CONDITIONS WILL EXIST ACROSS THE DACKS WHERE THE POPS WILL
BE HIGHER THAN THE REMAINDER OF THE TERRAIN LOCATIONS. A BRISK DAY
IS EXPECTED TOO AS SURFACE GRADIENT WILL BE TIGHT AND MIXING
LAYER HEIGHTS SUGGEST WE MAY TAP INTO THE MID-UPR 30KTS. AS THE
H850 TEMPS FALL BACK BELOW 0C...THIS TOO WILL BE REFLECTIVE WITH
FORECAST SURFACE TEMPERATURES WITH MAINLY 40S ACROSS THE TERRAIN
AND LOWER HALF OF THE 50S FOR VALLEY LOCATIONS. THIS WOULD BE A
COUPLE DEGREES BELOW NORMAL AS WE ARE FAST APPROACHING THE MIDDLE
OF THE MONTH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MUCH OF THE LONG TERM PERIOD WILL FEATURE SLIGHTLY ABOVE NORMAL
TEMPERATURES. PRECIPITATION IS MORE UNCERTAIN...BUT LATEST GUIDANCE
SEEMS TO FAVOR NEAR TO BELOW NORMAL AMTS.
STARTING WITH SUNDAY...RIDGING IS EXPECTED TO TRANSLATE ACROSS THE
REGION FROM THE WEST. THIS SHOULD ALLOW FOR GENERALLY SUNNY
SKIES...WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S IN MOST
VALLEYS...WITH 40S TO LOWER 50S ACROSS HIGHER ELEVATIONS. WINDS MAY
BE A BIT BRISK FROM THE WEST...ESP IN THE MORNING.
A GENERALLY ZONAL FLOW IS THEN EXPECTED TO PREDOMINATE FOR MON-TUE
WITH A FAST MOVING DISTURBANCE EXPECTED TO PASS NORTH OF THE
REGION MON NT-EARLY TUE. THIS MAY BRING A PERIOD OF SHOWERS FOR MON
AFTERNOON-NIGHT...ESP ACROSS NORTHERN AREAS. THIS SYSTEM APPEARS
RATHER PROGRESSIVE...SO EXPECT GENERALLY FAIR WEATHER TO RETURN BY
TUESDAY.
FOR LATE TUE-THU...MODELS EXHIBIT A BIT MORE UNCERTAINTY REGARDING
ADDITIONAL SHORTWAVE ENERGY APPROACHING FROM THE CENTRAL U.S...AND
LINGERING TROUGHING ACROSS THE EASTERN CANADA. THE BULK OF THE
00Z/09 GUIDANCE SEEMS TO FAVOR ENOUGH RIDGING BETWEEN THESE FEATURES
TO ALLOW FOR GENERALLY DRY CONDITIONS FROM LATE TUE INTO AT LEAST
MUCH OF WED. HOWEVER...SOME 00Z/09 GEFS MEMBERS SEEM TO ALLOW FOR A
WEAKER RIDGE AND MORE UPPER LEVEL ENERGY EJECTING EAST...INCREASING
THE CHANCES FOR SHOWERS. AT THIS TIME...HAVE SIDED ON THE DRIER SIDE
THROUGH WED WITH JUST SOME SLIGHT CHC POPS ACROSS SOUTHERN
AREAS...TO ACCOUNT FOR THE POSSIBILITY THAT SOME ENERGY/MOISTURE
APPROACHES A BIT FASTER FROM THE SOUTHWEST.
AS FOR TEMPS...EXPECT DAYTIME MAXES TO REACH THE LOWER/MID 60S IN
VALLEYS...AND 50S ACROSS HIGHER ELEVATIONS. THERE IS THE POSSIBILITY
OF EVEN WARMER MAX TEMPS COULD OCCUR IN VALLEY AREAS ASSUMING DEEPER
MIXING OCCURS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE 30S TO LOWER
40S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MVFR CEILINGS WILL PREVAIL AT THE TAF SITES THIS AFTERNOON...BEFORE
A RETURN TO MVFR/IFR FLYING CONDITIONS ASSOCIATED WITH RAIN ALONG A
WARM FRONT.
THIS AFTERNOON...MVFR CEILINGS WILL CONTINUE AT THE TAF SITES WITH
PLENTY OF LOW-LEVEL MOISTURE IN PLACE. AFTER 20Z...CEILINGS MAY
BRIEFLY RISE TO VFR...BUT GIVEN STRONG LOW-LEVEL INVERSION IN PLACE
TRAPPING MOISTURE AND LIMITING MIXING...HAVE SIDED WITH MVFR
CEILINGS THROUGH 00Z. WINDS WILL BE OUT OF THE EAST/SOUTHEAST
GENERALLY BETWEEN 5-10 KNOTS.
TONIGHT INTO FRIDAY...CHANCES FOR RAIN WILL RAPIDLY INCREASE AFTER
00Z AS A WARM FRONT LIFTS NORTH ACROSS THE REGION AND AN AREA OF LOW
PRESSURE APPROACHES FROM THE LOWER GREAT LAKES. EXPECT MVFR CEILINGS
AND VISIBILITIES AT THE TAF SITES WITH OCCASIONAL DRIZZLE BETWEEN
00Z-03Z...WITH A TEMPO GROUP FOR POSSIBLE IFR CEILINGS AT KPSF.
BY 03Z...EXPECT RAIN TO OVERSPREAD THE TAF SITES AND CONTINUE
THROUGH 12Z...WITH PERIODS OF HEAVIER RAIN ASSOCIATED WITH STRONGER
SHOWERS. THUNDER MAY BE POSSIBLE AT THE TAF SITES...BUT HAVE LEFT
MENTION OUT OF THIS TAF ISSUANCE FOR NOW AS CONFIDENCE IS LOW AT
THIS TIME. HAVE LOWERED CEILINGS AT THE TAF SITES TO IFR BEGINNING
AT 03Z...WITH BORDERLINE MVFR/IFR VISIBILITIES EXPECTED.
RAIN SHOULD BECOME MORE SHOWERY IN NATURE AFTER 12Z AND LINGER
ACROSS THE REGION THROUGH THE REMAINDER OF THE TAF PERIOD WITH
FLYING CONDITIONS IMPROVING SLIGHTLY TO MVFR...WITH IFR CEILINGS
PERSISTING UNTIL 14Z AT KPSF. WINDS WILL SHIFT TO THE
SOUTH/SOUTHEAST TONIGHT AND STRENGTHEN SLIGHTLY TO AROUND 10
KNOTS...WITH HIGHER GUSTS OF AROUND 20 KNOTS ASSOCIATED WITH ANY
STRONG SHOWER ACTIVITY.
HAVE INCLUDED LLWS AT KALB...KGFL AND KPOU FROM 06Z-12Z WITH AROUND
40 KNOTS OF WIND AROUND 2000 FT ABOVE A STRONG SURFACE-BASED
INVERSION. HAVE LEFT LLWS OUT OF KPSF FOR NOW AS SLIGHTLY BETTER
MIXING MAY OCCUR DUE TO THE TAF SITE BEING LOCATED NEAR THE TOP OF
THE INVERSION.
OUTLOOK...
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE REST OF THE WORK WEEK
DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL
WEATHER. DRIER WEATHER IS EXPECTED FROM LATER SATURDAY INTO
SUNDAY.
&&
.HYDROLOGY...
UNSETTLED AND COOL WEATHER IS EXPECTED THROUGH MUCH OF THE REST
OF THE WORK WEEK. A WARM FRONT IS EXPECTED TO LIFT BACK NORTH
THURSDAY NIGHT INTO FRIDAY...RESULTING IN A WARMUP WITH A
CONTINUED THREAT FOR RAIN AND EVEN A SLIGHT CHANCE OF
THUNDERSTORMS ON FRIDAY.
SNOW MELT COMBINING WITH PRECIPITATION THE PAST 24 HOURS RESULTED
IN THE MOHAWK RIVER EXPERIENCING WITHIN BANK RISES OVERNIGHT.
HOWEVER...A MORE SIGNIFICANT WARMUP IS EXPECTED ON
FRIDAY...WHICH IS WHEN MORE RAPID SNOW MELT IS EXPECTED. LATEST
MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY
EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING
ACTION STAGE BUT NO FLOODING AT THIS TIME. ONLY THE SACANDAGA
RIVER AT HOPE HAS A LOW PROBABILITY FORECAST TO REACH MINOR FLOOD
STAGE. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES
OVER THE NEXT SEVERAL DAYS. NONE THE NERFC FORECASTS HAVE ANY
POINTS REACHING FLOOD STAGE THE NEXT FEW DAYS.
TOTAL QPF THROUGH THURSDAY NIGHT MAY EXCEED A HALF AN INCH
ESPECIALLY ACROSS NORTHERN AREAS /ADIRONDACK REGION/.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...JPV/WASULA
SHORT TERM...BGM/WASULA
LONG TERM...KL/JPV
AVIATION...IRL
FIRE WEATHER...BGM/WASULA
HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 PM EDT THU APR 9 2015
.SYNOPSIS...
A WARM FRONT WILL BEGIN TO MOVE NORTH OF THE OHIO VALLEY AND THE
MID ATLANTIC REGION TODAY INTO TONIGHT. THIS WILL KEEP THE CLOUDS
ALONG WITH SOME LIGHT RAIN SHOWERS AND DRIZZLE TODAY WITH A
STEADIER RAINFALL EXPECTED TONIGHT. A MILDER AIR MASS WILL BE
ACROSS THE REGION BY FRIDAY AS THE WARM FRONT MOVES THROUGH...AND
A COLD FRONT WILL BRING SHOWERS AND A SLIGHT CHANCE FOR
THUNDERSTORMS LATE FRIDAY MORNING AND INTO THE AFTERNOON HOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 130 PM EDT...THE PATCHY DRIZZLE AND FREEZING DRIZZLE HAS
DIMINISHED ACROSS THE FCST AREA. IT IS STILL A VERY COOL AND DAMP
AIR MASS WITH TEMPS RUNNING ABOUT 15 T0 20 DEGREES BELOW NORMAL.
SOME PATCHY DRIZZLE WAS KEPT IN THE FCST AREA WRN NEW ENGLAND AND
THE SRN DACKS IN THE MID TO LATE PM. THE SPS FOR SPOTTY FREEZING
DRIZZLE ESPECIALLY OVER THE HIGHER TERRAIN WILL END AT 2 PM.
A WARM FRONT WILL BEGIN LIFTING N/NE FROM OH AND THE MID ATLANTIC
REGION LATE THIS AFTERNOON INTO TONIGHT. MAX TEMPS WILL GENERALLY
BE IN THE 30S TO L40S FOR THE REST OF THE DAY...AND STEADY OF
SLOWLY RISE INTO TONIGHT. THE LATEST HRRR HAS THE NEXT BATCH OF
PCPN MOVING IN BETWEEN 00Z-03Z WITH THE SHORT-WAVE IN THE SW FLOW
AND THE STRENGTHENING WARM ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...THE WARM FRONT QUICKLY LIFTS N/NE FROM THE LOWER GREAT
LAKES REGION AND PA ACROSS UPSTATE NY AND NEW ENGLAND AS THE
CENTER OF LOW PRESSURE TRACKS FROM THE MID MISSISSIPPI RIVER
VALLEY INTO THE CENTRAL GREAT LAKES REGION. THIS STORM WILL
INTENSIFY OVERNIGHT AS THE UPPER TROUGH BECOMES NEUTRAL TO
NEGATIVELY TILTED. EXPECT PERIODS OF RAIN AS MOIST LOW LEVEL JET
INCREASES WITH DEEP ISENTROPIC LIFT. THERE MAY BE A RUMBLE OF
THUNDER AROUND WEST AND SOUTH OF ALBANY AS THE SHOWALTER VALUES
FALLING CLOSE TO 0C TO -1C. LOWS THU NIGHT WILL RANGE FROM THE
U30S TO L40S ACROSS MOST THE REGION. SOME MELTING OF THE SNOW
PACK...ESPECIALLY OVER THE HIGHER TERRAIN IS EXPECTED. TOTAL RAIN
AMOUNTS LATE THU PM INTO FRI MORNING WILL BE IN THE QUARTER TO
THREE QUARTERS INCH RANGE WITH THE HIGHER TALLIES OVER THE SRN
DACKS.
FRIDAY...COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THE
MORNING AND INTO THE MID AFTERNOON HOURS. SHOWALTER VALUES DROP
ACROSS THE REMAINDER OF THE REGION TO VALUES AROUND 0C. THIS ALONG
WITH COLLABORATION WITH SPC...WE WILL CONTINUE WITH THE MENTION OF
THUNDER IN THE FORECAST/GRIDS. HIGHS IN THE LOWER AND M60S IN
MOST OF THE VALLEY AREAS /A FEW U60S OVER THE MID HUDSON
VALLEY/...AND M50S TO L60S OVER THE HILLS AND MTNS.
FRIDAY NIGHT...COLD ADVECTION OCCURS IN THE WAKE OF THE FRONT
WITH PRETTY GOOD SUBSIDENCE TO END MOST OF THE PCPN FOR THE FCST
AREA...THOUGH A FEW UPSLOPE RAIN TO SNOW SHOWERS ARE POSSIBLE OVER
THE WRN DACKS. LOWS WILL BE IN THE M30S TO L40S IN MOST LOCATIONS
WITH A FEW U20S TO L30S OVER THE SRN DACKS.
SATURDAY...THE MAIN UPPER TROUGH AXIS AND SECONDARY COLD FRONT
WILL CROSS THE REGION. THE BEST MOISTURE PROFILES AND FAVORABLE
UPSLOPE CONDITIONS WILL EXIST ACROSS THE DACKS WHERE THE POPS WILL
BE HIGHER THAN THE REMAINDER OF THE TERRAIN LOCATIONS. A BRISK DAY
IS EXPECTED TOO AS SURFACE GRADIENT WILL BE TIGHT AND MIXING
LAYER HEIGHTS SUGGEST WE MAY TAP INTO THE MID-UPR 30KTS. AS THE
H850 TEMPS FALL BACK BELOW 0C...THIS TOO WILL BE REFLECTIVE WITH
FORECAST SURFACE TEMPERATURES WITH MAINLY 40S ACROSS THE TERRAIN
AND LOWER HALF OF THE 50S FOR VALLEY LOCATIONS. THIS WOULD BE A
COUPLE DEGREES BELOW NORMAL AS WE ARE FAST APPROACHING THE MIDDLE
OF THE MONTH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MUCH OF THE LONG TERM PERIOD WILL FEATURE SLIGHTLY ABOVE NORMAL
TEMPERATURES. PRECIPITATION IS MORE UNCERTAIN...BUT LATEST GUIDANCE
SEEMS TO FAVOR NEAR TO BELOW NORMAL AMTS.
STARTING WITH SUNDAY...RIDGING IS EXPECTED TO TRANSLATE ACROSS THE
REGION FROM THE WEST. THIS SHOULD ALLOW FOR GENERALLY SUNNY
SKIES...WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S IN MOST
VALLEYS...WITH 40S TO LOWER 50S ACROSS HIGHER ELEVATIONS. WINDS MAY
BE A BIT BRISK FROM THE WEST...ESP IN THE MORNING.
A GENERALLY ZONAL FLOW IS THEN EXPECTED TO PREDOMINATE FOR MON-TUE
WITH A FAST MOVING DISTURBANCE EXPECTED TO PASS NORTH OF THE
REGION MON NT-EARLY TUE. THIS MAY BRING A PERIOD OF SHOWERS FOR MON
AFTERNOON-NIGHT...ESP ACROSS NORTHERN AREAS. THIS SYSTEM APPEARS
RATHER PROGRESSIVE...SO EXPECT GENERALLY FAIR WEATHER TO RETURN BY
TUESDAY.
FOR LATE TUE-THU...MODELS EXHIBIT A BIT MORE UNCERTAINTY REGARDING
ADDITIONAL SHORTWAVE ENERGY APPROACHING FROM THE CENTRAL U.S...AND
LINGERING TROUGHING ACROSS THE EASTERN CANADA. THE BULK OF THE
00Z/09 GUIDANCE SEEMS TO FAVOR ENOUGH RIDGING BETWEEN THESE FEATURES
TO ALLOW FOR GENERALLY DRY CONDITIONS FROM LATE TUE INTO AT LEAST
MUCH OF WED. HOWEVER...SOME 00Z/09 GEFS MEMBERS SEEM TO ALLOW FOR A
WEAKER RIDGE AND MORE UPPER LEVEL ENERGY EJECTING EAST...INCREASING
THE CHANCES FOR SHOWERS. AT THIS TIME...HAVE SIDED ON THE DRIER SIDE
THROUGH WED WITH JUST SOME SLIGHT CHC POPS ACROSS SOUTHERN
AREAS...TO ACCOUNT FOR THE POSSIBILITY THAT SOME ENERGY/MOISTURE
APPROACHES A BIT FASTER FROM THE SOUTHWEST.
AS FOR TEMPS...EXPECT DAYTIME MAXES TO REACH THE LOWER/MID 60S IN
VALLEYS...AND 50S ACROSS HIGHER ELEVATIONS. THERE IS THE POSSIBILITY
OF EVEN WARMER MAX TEMPS COULD OCCUR IN VALLEY AREAS ASSUMING DEEPER
MIXING OCCURS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE 30S TO LOWER
40S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
A WARM FRONT WILL SLOWLY APPROACH FROM THE SOUTHWEST LATER TODAY
AND TONIGHT. AHEAD OF THIS FRONT...A COOL AND MOIST AIRMASS WILL
REMAIN IN PLACE...WITH SPOTTY AREAS OF DRIZZLE. SOME POCKETS OF
FREEZING DRIZZLE WILL REMAIN POSSIBLE THROUGH 14Z/THU AT KPSF.
FLIGHT CONDITIONS WILL BE MAINLY MVFR THROUGH MOST OF TODAY.
HOWEVER...IFR CIGS/VSBYS WILL LIKELY LINGER AT KALB THROUGH AROUND
15Z-17Z/THU. OCCASIONAL IFR...ESP FOR CIGS...AT KPSF THROUGH
AROUND 14Z/THU. ADDITIONAL...MORE WIDESPREAD IFR CONDITIONS WILL
BECOME POSSIBLE LATER TONIGHT AS THE WARM FRONT APPROACHES.
AS FOR PRECIPITATION CHANCES...IT APPEARS THAT LITTLE IF ANY
SIGNIFICANT PRECIPITATION OTHER THAN DRIZZLE IS EXPECTED THROUGH
MUCH OF TODAY. THEN...RAIN SHOWERS WILL BECOME POSSIBLE LATER THIS
AFTERNOON...MAINLY AFTER 00Z/THU...WITH OCCASIONAL RAIN SHOWERS
EXPECTED INTO MUCH OF TONIGHT.
WINDS WILL THEN TREND INTO THE EAST TO SOUTHEAST TODAY AND INCREASE
TO 8-12 KT AND SHOULD CONTINUE INTO TONIGHT. SOME SLIGHTLY STRONGER
GUSTS OF UP TO 20-25 KT COULD OCCUR THIS AFTERNOON AND EVENING.
OUTLOOK...
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE REST OF THE WORK WEEK
DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL
WEATHER. DRIER WEATHER IS EXPECTED FROM LATER SATURDAY INTO
SUNDAY.
&&
.HYDROLOGY...
UNSETTLED AND COOL WEATHER IS EXPECTED THROUGH MUCH OF THE REST
OF THE WORK WEEK. A WARM FRONT IS EXPECTED TO LIFT BACK NORTH
THURSDAY NIGHT INTO FRIDAY...RESULTING IN A WARMUP WITH A
CONTINUED THREAT FOR RAIN AND EVEN A SLIGHT CHANCE OF
THUNDERSTORMS ON FRIDAY.
SNOW MELT COMBINING WITH PRECIPITATION THE PAST 24 HOURS RESULTED
IN THE MOHAWK RIVER EXPERIENCING WITHIN BANK RISES OVERNIGHT.
HOWEVER...A MORE SIGNIFICANT WARMUP IS EXPECTED ON
FRIDAY...WHICH IS WHEN MORE RAPID SNOW MELT IS EXPECTED. LATEST
MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY
EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING
ACTION STAGE BUT NO FLOODING AT THIS TIME. ONLY THE SACANDAGA
RIVER AT HOPE HAS A LOW PROBABILITY FORECAST TO REACH MINOR FLOOD
STAGE. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES
OVER THE NEXT SEVERAL DAYS. NONE THE NERFC FORECASTS HAVE ANY
POINTS REACHING FLOOD STAGE THE NEXT FEW DAYS.
TOTAL QPF THROUGH THURSDAY NIGHT MAY EXCEED A HALF AN INCH
ESPECIALLY ACROSS NORTHERN AREAS /ADIRONDACK REGION/.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...JPV/WASULA
SHORT TERM...BGM/WASULA
LONG TERM...KL/JPV
AVIATION...KL/JPV
FIRE WEATHER...BGM/WASULA
HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
316 PM CDT THU APR 9 2015
.MESOSCALE DISCUSSION...
241 PM CDT
THUNDERSTORM ACTIVITY CONTINUES ACROSS PORTIONS OF CENTRAL
ILLINOIS THIS AFTERNOON THOUGH HAVE AT LEAST TEMPORARILY SHOWN
SIGNS OF WEAKENING WITH DIMINISHED LIGHTNING ACTIVITY NOTED AND
SUBTLE WARMING OF THE CLOUD TOPS. THESE STORMS HAVE MAINLY BEEN
ALONG THE LEADING EDGE OF THE INSTABILITY GRADIENT WHICH IS
ADVECTING NORTHEAST THIS AFTERNOON. OVER THE LAST FEW HOURS ALL OF
NORTHERN ILLINOIS HAS UNDERGONE AT LEAST MODEST DESTABILIZATION
WHILE THE GREATEST AMOUNT HAS OCCURRED OVER CENTRAL ILLINOIS.
STORMS ARE MOVING INTO A BETTER LOW LEVEL SHEAR ENVIRONMENT AND
WITH THE GIVEN DESTABILIZATION EXPECT THAT THE WEAKENING TREND
WILL BE TEMPORARY. ALREADY HAVE SEEN NEW TOWERS BUILDING IN
ADVANCE OF THE ORIGINAL THUNDERSTORM CLUSTER.
FARTHER WEST THE COLD FRONT CONTINUES TO SHOW SIGNS OF INCREASING
CONVECTION THOUGH COLD POOL IS NOT READILY EVIDENT AS OF YET. OUT
AHEAD OF THE COLD FRONT...PARTIAL CLEARING HAS ALLOWED TEMPS TO
WARM INTO THE MID/UPPER 70S WITH LOW/MID 60 DEWPOINTS RESULTING IN
STRONG INSTABILITY ALONG WITH STRONG DCAPE. EXPECT CONVECTION TO
CONTINUE TO INCREASE IN INTENSITY AND FOR COLD POOLS TO MERGE IN
THE NEXT HOUR OR TWO WITH ACCELERATION OF THE LINE PER CORFIDI
VECTORS OF 40-50 KTS. GIVEN THE STRONG LOW LEVEL SHEAR AND
INCREASING DEEP LAYER SHEAR OUT AHEAD AND BOUNDARIES FROM THE
FIRST CLUSTER OF CONVECTION...THERE REMAINS A TORNADO THREAT AS
THIS LINE MOVE INTO NORTHERN ILLINOIS.
DEUBELBEISS
&&
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
257 PM CDT
FRIDAY THROUGH THURSDAY...
FOLLOWING A PERIOD OF VERY ACTIVE WEATHER...FOLLOWING THE PASSAGE OF
THE COLD FRONT LATE THURSDAY NIGHT...A PERIOD OF RELATIVE CALM WILL
SET UP FOR FRIDAY INTO SUNDAY AS A COOL...DRY HIGH PRESSURE AREA
BUILDS ACROSS THE AREA. TEMPERATURES WILL DROP BACK TO CLOSER TO
SEASONAL HIGHS NORMAL LEVELS WITH HIGHS IN THE UPPER 50S TO AROUND
60F UNDER MOSTLY SUNNY SKIES. AS THE HIGH WILL BE RIGHT OVER THE
AREA FRIDAY NIGHT INTO SATURDAY MORNING...LIGHT WINDS AND A DRY
AIRMASS WILL ALLOW FOR SOME ENHANCED RADIATIVE COOLING OVERNIGHT FOR
LOWS TO DROP BACK INTO THE MIDDLE TO UPPER 30S SATURDAY MORNING.
WITH THE HIGH BEGINNING TO BUILD OFF TO THE EAST THROUGH SATURDAY
NIGHT AND SUNDAY...A RETURN FLOW OF MOISTURE AND WARMER AIR WILL
KEEP THE COOLING TREND VERY BRIEF WITH TEMPS REBOUNDING BACK TO
AROUND 60F OVER MUCH OF THE CWA...WITH THE EXCEPTION OF THE
IMMEDIATE LAKEFRONT...WHICH SHOULD REMAIN COOLER AS A WEAK PRESSURE
GRADIENT AND DIFFERENTIAL HEATING BETWEEN THE COOL LAKE WATER AND
WARMER LAKE SHOULD ALLOW A LAKE BREEZE TO DEVELOP. HIGHS ON
SATURDAY ALONG THE LAKE FRONT TOPPING OUT IN THE MIDDLE 50S.
INCREASING SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE HIGH
MOVING OFF TO THE EAST WILL LIKELY PREVENT A LAKE BREEZE FROM
DEVELOPING.
FOR SUNDAY...A NORTHERN STREAM SHORT WAVE MOVING OUT OF THE NRN
ROCKIES SHOULD BEGIN TO PHASE WITH A SOUTHERN STREAM SHORTWAVE
LIFTING INTO THE MIDDLE MISSISSIPPI VALLEY. THIS PHASING SHOULD
RESULT IN AN AMPLIFYING LONG WAVE TROUGH OVER THE MIDDLE AND UPPER
MISSISSIPPI VALLEY AND BRINGING THE NEXT CHANCE OF PCPN TO THE
REGION. THE LONGER RANGE GUIDANCE...IN GENERAL...AGREE ON THE
SCENARIO...BUT DIFFERENCES IN THE TIMING OF THE INDIVIDUAL SHORTWAVE
AND THE DEGREE OF PHASING AND THE RESULTANT STRENGTH OF THE LONG
WAVE TROUGH LEAD TO A RELATIVELY LOW CONFIDENCE FORECAST FOR THE
LATTER PORTIONS OF THE EXTENDED FORECAST PERIOD. CURRENTLY FEEL
THAT A COLD FRONT MOVING ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT
AND THEN SHUTTING OFF BY MONDAY MORNING AS ANOTHER HIGH PRESSURE
SYSTEM MOVES ACROSS THE AREA. WHILE THERE IS MODERATE TO HIGH
CONFIDENCE IN A PERIOD OF PCPN SUNDAY AND SUNDAY NIGHT...START AND
END TIMES REMAIN UNCERTAIN AS WELL AS THE CHANCES FOR THUNDERSTORMS
WITH THE PCPN AND WILL LIKELY BE HIGHLY DEPENDENT ON THE SPEED OF AN
ASSOCIATED COLD FRONT MOVING THROUGH THE AREA. FOR THE LATTER
PORTIONS OF THE FORECAST PERIOD...FROM TUESDAY THROUGH
THURSDAY...THERE COULD BE ANOTHER PERIOD OF UNSETTLED WEATHER AS THE
UPPER LEVEL FLOW PATTERN MAINTAINS A HIGH AMPLITUDE...QUICKLY
PROGRESSIVE PATTERN. THE GFS/ECMWF ARE ACTUALLY SHOWING BETTER
CONSISTENCY FOR THE END OF THE LONGER TERM FORECAST PERIOD THAN
EARLIER...WITH ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE CNTRL
PLAINS. THE ECMWF IS TRENDING A BIT STRONGER AND DEVELOPING MORE OF
A NEGATIVE TILT TO THE TROUGH AND A CLOSED UPPER LOW BY WEDNESDAY
NIGHT...THE GFS IS REMARKABLY SIMILAR...BUT ABOUT 24 HOURS SLOWER IN
DEVELOPING THE NEGATIVE TILT UPPER TROUGH AND CLOSED UPPER LOW.
SHOULD THIS SCENARIO PAN OUT...THE MIDDLE OF NEXT WEAK COULD BE RIPE
FOR ANOTHER PERIOD OF ACTIVE WEATHER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SCATTERED STORMS EXPECTED THIS AFTN...WITH THE FINAL ROUND OF
STORMS MOVING THROUGH ARND 2Z. SOME OF THESE STORMS COULD BE
SEVERE.
* GUSTY SSW WINDS WITH GUSTS ARND 25 KT.
* IFR VSBY EXPECTED WITH TSRA.
* GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT.
JEE
//DISCUSSION...UPDATED 18Z...
STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR
WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS
OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA
THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING
CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT
THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW
STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND
CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON
INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT
EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS
MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN
ISOLATED TORNADO.
THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF
ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE
PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH
GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A
SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN
COVERAGE THIS AFTERNOON AND TIMING.
* MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS.
WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME.
* HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW
CONFIDENCE IN CIG HEIGHTS.
* MEDIUM CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...GUSTS
COULD BE HIGHER.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.
&&
.MARINE...
315 PM CDT
CONDITIONS OVER LAKE MICHIGAN ARE DETERIORATING RAPIDLY
TODAY...FIRST WITH WAVES OF THUNDERSTORMS CROSSING THE SOUTHERN
PORTIONS OF THE LAKE AS A WARM FRONT LIFTS NORTHWARD. AS OF 3PM
CDT...THE FRONT HAD MOVED UP TO THE CENTER OF THE LAKE AND SHOULD
CONTINUE TO LIFT NORTHWARD AS DEEPENING LOW PRESSURE OVER EASTERN
IOWA CONTINUES TO DEEPEN AND TRACKS INTO SOUTHERN WISCONSIN BY EARLY
THIS EVENING. BY THIS POINT...THE SOUTHERLY FLOW WILL REACH ALMOST
TO THE NORTH END OF THE LAKE...BUT WITH STRONG PRESSURE FALLS AND A
STRENGTHENING PRESSURE GRADIENT OVER THE LAKE AS THE SFC LOW
APPROACHES...WINDS OVER THE SRN PORTIONS OF THE LAKE SHOULD INCREASE
TO GALE FORCE FOR THE NEARSHORE WATERS AND THE SOUTH HALF OF THE
LAKE. THUNDERSTORMS WILL ALSO CONTINUE TO BE A CONCERN INTO THE
EVENING AS WELL. THE SFC LOW IS EXPECTED TO TRACK ACROSS THE CNTRL
PORTIONS OF THE LAKE LATE THIS EVENING...WITH WINDS QUICKLY SHIFTING
TO WLY-NWLY. A STRONG NORTHERLY GRADIENT BEHIND THE EXITING
LOW...INCREASING COLD ADVECTION ASSOCIATED WITH A COOL HIGH PRESSURE
SYSTEM DROPPING INTO THE NRN PLAINS AND STRONG PRESSURE RISES AS A
RESULT OF THE COMBINATION OF THE EXITING LOW AND APPROACHING
HIGH...SHOULD ALL COMBINE TO BRING SHORT PERIOD OF WEST TO NWLY
GALES TO THE LAKE INTO FRIDAY AFTERNOON. THE APPROACHING HIGH
SHOULD BEGIN TO OVERSPREAD THE WESTERN GREAT LAKES BY FRIDAY
AFTERNOON...ALLOWING WINDS OVER THE LAKE TO DROP OFF RELATIVELY
QUICKLY. FOR THE WEEKEND AND INTO EARLY NEXT WEEK...CONDITIONS OVER
THE LAKE SHOULD BE RELATIVELY QUIET. ANOTHER COLD FRONT IS EXPECTED
TO SWEEP ACROSS THE LAKE SUNDAY NIGHT OR MONDAY...BUT THIS SHOULD BE
A LESS DYNAMIC SYSTEM...AND WINDS SHOULD NOT GET AS STRONG AS WITH
THE SYSTEM APPROACHING THE LAKE AT THE CURRENT TIME.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
308 PM CDT Thu Apr 9 2015
.SHORT TERM...(Tonight)
ISSUED AT 307 PM CDT THU APR 9 2015
19z/2pm surface analysis shows 998mb low centered over southeast
Iowa, with cold front trailing southward into western Missouri.
Line of convection is rapidly developing along the front within the
moderately unstable and uncapped airmass in the warm sector. 0-6km
bulk shear values will be on the increase as the afternoon
progresses as a mid-level short-wave approaches from the west,
resulting in continued convective intensification. HRRR has had a
good handle on the situation throughout the day, with its latest
iteration agreeing closely with prior runs. Based on satellite
timing tools and HRRR guidance, it appears the line of storms will
cross the Mississippi River by 23z/6pm, then will track through the
Illinois River Valley and to the I-55 corridor by about 02z/8pm.
Damaging wind gusts will be the primary threat, but large hail and a
few tornadoes will be possible as well. As the storms move further
east, they will likely congeal into a solid line and the tornado
threat will diminish accordingly. Once the front passes, windy and
cooler weather will be on tap overnight with a slow west to east
clearing trend by dawn.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 307 PM CDT THU APR 9 2015
Morning upper air shows a pontential severe event this afternoon and
evening, as main upper level shortwave and vort max over southwest
NE at 12z will be rotating to the east. Low level thermal ridge and
moisutre axis extends into MO/IL ahead of the approaching front.
lowl level jet is particularly strong flowing into MO/western IL and
so ample shear available in warm sector.
HRR model and NAM a little slower on the movement of the front
through the region, going through this evening. Shear with strong
upper jet and low level southern jet will make severe potential with
severe storms possible on the cold front as it sweeps through.
Deepening surface low to move northeast into eastern IA and then
southern WI.
High pressure in control until weak front moves in and brings
showers on late sunday and sunday night. Another chance off showers
Tuesday into Thursday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1255 PM CDT THU APR 9 2015
Strong southwesterly winds will prevail this afternoon, with
frequent gusts to between 25 and 35kt. Convection will initially
be isolated, but will become more widespread by late afternoon
into the early evening as a cold front moves in from the west.
High-res models are in good agreement that a line of storms will
develop along the advancing front near/west of the Mississippi
River by mid to late afternoon, then push eastward into Illinois
after that. Based on HRRR timing, have included a TEMPO group for
thunder at KPIA between 23z and 01z, then further east to KCMI
between 02z and 04z. Once storms pass, winds will veer to the west
and increase and remain quite gusty through the night. In
addition, MVFR ceilings currently across western Iowa into Kansas
will spill eastward, with forecast soundings suggesting low clouds
remaining in place until close to dawn Friday. After that, am
expecting mostly clear skies with continued brisk westerly winds
Friday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 1 AM CDT Friday FOR ILZ054>057-061>063-
066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Goetsch
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
154 PM CDT THU APR 9 2015
.MESOSCALE DISCUSSION...
152 PM CDT
A TORNADO WATCH HAS BEEN ISSUED FOR NORTHERN ILLINOIS AND
NORTHWEST INDIANA. AS PREVIOUSLY MENTIONED...THERE ARE TWO AREAS
OF CONCERN WHICH HAS RESULTED IN A LONGER DURATION TORNADO WATCH
THAN NORMAL...IN EFFECT UNTIL 11 PM CDT THIS EVENING. THE FIRST
AREA OF CONCERN IS AN MCV LIFTING INTO WEST CENTRAL ILLINOIS.
THUNDERSTORMS ARE MOVING INTO THE LOT FORECAST AREA AS OF 2 PM CDT
AND WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE CHICAGO METRO OVER
THE NEXT COUPLE HOURS. THE SECOND AREA IS ASSOCIATED WITH A
SURFACE LOW OVER SOUTH CENTRAL IOWA...AND ITS ATTENDANT WARM/COLD
FRONTS WHICH WILL IMPACT THE FORECAST AREA LATER THIS EVENING.
DEUBELBEISS
PREVIOUS DISCUSSION...125 PM CDT
A FEW THUNDERSTORMS HAVE DEVELOPED JUST NORTHWEST/NORTH OF PEORIA
THIS AFTERNOON AHEAD OF AN MCV LIFTING ACROSS THE MID MISSISSIPPI
VALLEY. LATEST RAP SHOWS 35-40KT 0-6 KM SHEAR ACROSS THE REGION WITH
MODERATELY STRONG INSTABILITY AROUND 1500 J/KG. SPECIAL 18Z SOUNDING
FROM ILX SHOWS STRONG LAPSE RATES ATOP A MODERATELY CAPPED BOUNDARY
LAYER...HOWEVER CAPPING WAS FAIRLY NON-EXISTENT ON THE 18Z DVN
SOUNDING. NOT SURPRISING GIVEN THE DEEP LAYER SHEAR THAT RADAR
IMAGERY SHOWS MODEST MIDLEVEL ROTATION WITHIN THE STORMS WHICH
HAVE UNDERGONE GRADUAL INTENSIFICATION OVER THE LAST HOUR OR SO
AND ALSO HAVE THREE BODY SCATTER SPIKES AT TIMES. EXPECT THESE
STORMS TO CONTINUE TO LIFT NORTHEAST ALONG THE LEADING EDGE OF THE
INSTABILITY GRADIENT AND WILL LIKELY PERSIST INTO THE LOT FORECAST
AREA. WILL HAVE TO CLOSELY MONITOR THESE STORMS FOR AN ISOLATED
SEVERE THREAT OVER THE NEXT COUPLE HOURS. FARTHER
WEST...CONVECTION IS INCREASING ACROSS NORTHERN MISSOURI AND SOUTH
CENTRAL IOWA ALONG THE COLD FRONT AND A TORNADO WATCH HAS BEEN
ISSUED JUST TO OUR WEST. THIS LINE OF THUNDERSTORMS REMAINS A
CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING.
DEUBELBEISS
PREVIOUS DISCUSSION...1228 PM CDT
CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING.
BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO
SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER
NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES
SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH
SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT
WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE
OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS
AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING
SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY
UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO
IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE
CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH
CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A
SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE
WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES.
IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE
CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN
EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND
FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN
CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE
WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE
WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL
AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON
AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE
CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER
40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR.
ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME
THEN THE TORNADO THREAT WOULD BE HIGHER.
IZZI
&&
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
416 AM CDT...
FRIDAY THROUGH WEDNESDAY...
DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT
TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES
OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS
INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD
ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY
EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES
DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH...
WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A
FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE
AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION
OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH
MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY
SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL.
LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE
EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD
OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF
PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST
ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE
DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING
NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO
INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL
MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM
UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR
TUE-WED.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE
FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE
STORMS COULD BE SEVERE.
* GUSTY SSW WINDS WITH GUSTS ARND 25 KT.
* IFR CIGS AND VSBY PSBL WITH TSRA.
* GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT.
JEE
//DISCUSSION...UPDATED 18Z...
STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR
WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS
OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA
THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING
CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT
THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW
STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND
CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON
INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT
EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS
MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN
ISOLATED TORNADO.
THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF
ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE
PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH
GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A
SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN
COVERAGE THIS AFTERNOON AND TIMING.
* MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS.
WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME.
* HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW
CONFIDENCE IN CIG HEIGHTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.
&&
.MARINE...
416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST
TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM
FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD
OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY
ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY
INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE
LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS
EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE
WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO
BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER
NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF
THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT
FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH
PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 PM CDT THU APR 9 2015
.MESOSCALE DISCUSSION...
125 PM CDT
A FEW THUNDERSTORMS HAVE DEVELOPED JUST NORTHWEST/NORTH OF PEORIA
THIS AFTERNOON AHEAD OF AN MCV LIFTING ACROSS THE MID MISSISSIPPI
VALLEY. LATEST RAP SHOWS 35-40KT 0-6 KM SHEAR ACROSS THE REGION WITH
MODERATELY STRONG INSTABILITY AROUND 1500 J/KG. SPECIAL 18Z SOUNDING
FROM ILX SHOWS STRONG LAPSE RATES ATOP A MODERATELY CAPPED BOUNDARY
LAYER...HOWEVER CAPPING WAS FAIRLY NON-EXISTENT ON THE 18Z DVN
SOUNDING. NOT SURPRISING GIVEN THE DEEP LAYER SHEAR THAT RADAR
IMAGERY SHOWS MODEST MIDLEVEL ROTATION WITHIN THE STORMS WHICH
HAVE UNDERGONE GRADUAL INTENSIFICATION OVER THE LAST HOUR OR SO
AND ALSO HAVE THREE BODY SCATTER SPIKES AT TIMES. EXPECT THESE
STORMS TO CONTINUE TO LIFT NORTHEAST ALONG THE LEADING EDGE OF THE
INSTABILITY GRADIENT AND WILL LIKELY PERSIST INTO THE LOT FORECAST
AREA. WILL HAVE TO CLOSELY MONITOR THESE STORMS FOR AN ISOLATED
SEVERE THREAT OVER THE NEXT COUPLE HOURS. FARTHER
WEST...CONVECTION IS INCREASING ACROSS NORTHERN MISSOURI AND SOUTH
CENTRAL IOWA ALONG THE COLD FRONT AND A TORNADO WATCH HAS BEEN
ISSUED JUST TO OUR WEST. THIS LINE OF THUNDERSTORMS REMAINS A
CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING.
PREVIOUS DISCUSSION...
1228 PM CDT
CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING.
BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO
SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER
NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES
SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH
SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT
WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE
OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS
AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING
SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY
UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO
IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE
CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH
CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A
SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE
WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES.
IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE
CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN
EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND
FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN
CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE
WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE
WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL
AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON
AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE
CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER
40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR.
ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME
THEN THE TORNADO THREAT WOULD BE HIGHER.
IZZI
&&
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
416 AM CDT...
FRIDAY THROUGH WEDNESDAY...
DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT
TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES
OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS
INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD
ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY
EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES
DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH...
WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A
FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE
AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION
OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH
MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY
SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL.
LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE
EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD
OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF
PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST
ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE
DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING
NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO
INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL
MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM
UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR
TUE-WED.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE
FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE
STORMS COULD BE SEVERE.
* GUSTY SSW WINDS WITH GUSTS ARND 25 KT.
* IFR CIGS AND VSBY PSBL WITH TSRA.
* GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT.
JEE
//DISCUSSION...UPDATED 18Z...
STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR
WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS
OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA
THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING
CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT
THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW
STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND
CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON
INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT
EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS
MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN
ISOLATED TORNADO.
THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF
ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE
PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH
GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A
SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN
COVERAGE THIS AFTERNOON AND TIMING.
* MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS.
WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME.
* HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW
CONFIDENCE IN CIG HEIGHTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.
&&
.MARINE...
416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST
TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM
FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD
OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY
ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY
INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE
LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS
EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE
WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO
BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER
NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF
THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT
FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH
PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
103 PM CDT THU APR 9 2015
.MESOSCALE DISCUSSION...
1228 PM CDT
CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING.
BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO
SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER
NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES
SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH
SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT
WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE
OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS
AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING
SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY
UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO
IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE
CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH
CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A
SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE
WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES.
IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE
CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN
EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND
FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN
CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE
WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE
WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL
AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON
AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE
CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER
40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR.
ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME
THEN THE TORNADO THREAT WOULD BE HIGHER.
IZZI
&&
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
416 AM CDT...
FRIDAY THROUGH WEDNESDAY...
DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT
TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES
OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS
INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD
ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY
EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES
DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH...
WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A
FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE
AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION
OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH
MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY
SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL.
LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE
EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD
OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF
PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST
ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE
DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING
NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO
INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL
MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM
UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR
TUE-WED.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE
FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE
STORMS COULD BE SEVERE.
* GUSTY SSW WINDS WITH GUSTS ARND 25 KT.
* IFR CIGS AND VSBY PSBL WITH TSRA.
* GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT.
JEE
//DISCUSSION...UPDATED 18Z...
STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR
WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS
OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA
THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING
CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT
THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW
STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND
CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON
INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT
EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS
MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN
ISOLATED TORNADO.
THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF
ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE
PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH
GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE
EXPECTED TOMORROW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A
SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN
COVERAGE THIS AFTERNOON AND TIMING.
* MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS.
WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME.
* HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW
CONFIDENCE IN CIG HEIGHTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.
&&
.MARINE...
416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST
TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM
FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD
OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY
ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY
INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE
LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS
EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE
WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO
BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER
NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF
THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT
FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH
PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1255 PM CDT Thu Apr 9 2015
.UPDATE...
ISSUED AT 1007 AM CDT THU APR 9 2015
15z/10am surface analysis shows 1000mb low centered just north of
Kansas City, with warm front extending eastward into northern
Illinois. Front has now lifted north of the KILX CWA, placing the
entire area firmly in the warm sector. Widespread early morning
convection is in the process of exiting into northern Indiana,
leaving behind just scattered showers/storms for the time being.
Further upstream, the next upper-level impulse is triggering a
renewed round of convection across western Missouri. Based on
timing tools and the latest HRRR guidance, this activity will move
into the SW CWA between 17z and 18z. Once this wave departs,
attention will turn to the approaching cold front which is still
on target for a late afternoon/early evening arrival. Airmass
ahead of the front will become moderately unstable and highly
sheared, so threat for strong to severe thunderstorms is still
present. Current indications suggest the primary time frame will
be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the
main threat with the storms, although large hail and isolated
tornadoes will also be possible as the cells first begin to
develop. Made some changes to hourly PoPs to better reflect
current and expected trends, but changes were minor and did not
require a full zone update at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 303 AM CDT THU APR 9 2015
Latest surface analysis shows the warm front has lifted to the I-74
corridor early this morning with a chaotic wind field across most of
the forecast area. Not sure what the affect the current scattered
convection will have on the position of the frontal boundary thru
the morning hours, but most of the models suggest a continued slow
push to the north as the main surface low tracks northeast to
central Iowa by late this morning. Current thinking is that the cold
front will be positioned just west of the Mississippi River by 21z
with surface based convection developing ahead of the front at that
time as well. Better low level helicity fields supportive of
discrete supercells and possible tornadoes looks to be closer to the
track of the surface low...which by late afternoon is expected to be
in far southwest Wisconsin or northwest Illinois. That would put the
threat for more persistent low level rotating storms just to our
west and north. However, still plenty of shear ahead of the frontal
boundary this afternoon and early this evening to promote damaging
straight line winds as the storms transition into more of a linear
system. Temperature-wise, with the warm front to our north this
afternoon, will continue to go with the warmer guid values most
areas. Latest model data now suggests the backedge of the precip
pushes out of our far southeast counties by midnight, so will extend
the Flash Flood Watch until that time this evening.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 303 AM CDT THU APR 9 2015
Showers and thunderstorms, possibly severe, will be ongoing across
at least the eastern half of the forecast area to start this
evening. Despite the short forecast range, there is still some
spread in the expected cold frontal timing. However, it appears
reasonable that the front will lie somewhere between the Illinois
River and the I-55 corridor by 00Z Friday. Sped up the decrease in
shower/storm chances by mid evening, and I would not be surprised to
see the precipitation chances taper off a few hours earlier,
especially if the squall line gets a head of steam and trends
further ahead of the front than current progs.
Once the front clears the area tonight, quiet conditions, along with
much cooler and less humid air will build across the region into
Sunday. These conditions will be driven by a large area of high
pressure of Canadian origin. While conditions will be notably
cooler/less humid, they will still be at or above normal for early
April.
The next precipitation chances will arrive later Sunday into Sunday
night as a cold front is dragged across the area. While this front
is still expected to stall out at it begins to parallel the
upper-level flow, model trends suggest the front will stall out
further south than previously anticipated. If these trends persist,
Monday and Monday night will end up dry. For now, have reduced but
not eliminated PoPs Monday/Monday night until we see if this recent
model trend sticks.
A slow moving upper-level disturbance will push the front back into
the area by Tuesday, bringing renewed shower/storm chances. The
front and/or upper level disturbances will keep the rain chances
going into the end of the work week. Temperatures should remain at
or above normal through the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1255 PM CDT THU APR 9 2015
Strong southwesterly winds will prevail this afternoon, with
frequent gusts to between 25 and 35kt. Convection will initially
be isolated, but will become more widespread by late afternoon
into the early evening as a cold front moves in from the west.
High-res models are in good agreement that a line of storms will
develop along the advancing front near/west of the Mississippi
River by mid to late afternoon, then push eastward into Illinois
after that. Based on HRRR timing, have included a TEMPO group for
thunder at KPIA between 23z and 01z, then further east to KCMI
between 02z and 04z. Once storms pass, winds will veer to the west
and increase and remain quite gusty through the night. In
addition, MVFR ceilings currently across western Iowa into Kansas
will spill eastward, with forecast soundings suggesting low clouds
remaining in place until close to dawn Friday. After that, am
expecting mostly clear skies with continued brisk westerly winds
Friday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063-
066>068-071>073.
&&
$$
UPDATE...Barnes
SHORT TERM...Smith
LONG TERM...Bak
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT THU APR 9 2015
.SHORT TERM...
400 AM CDT
TODAY AND TONIGHT...
DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.
CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.
WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.
RATZER
&&
.LONG TERM...
416 AM CDT...
FRIDAY THROUGH WEDNESDAY...
DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT
TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES
OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS
INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD
ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY
EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES
DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH...
WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A
FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE
AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION
OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH
MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY
SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL.
LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE
EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD
OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF
PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST
ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE
DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING
NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO
INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL
MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM
UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR
TUE-WED.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* ONE FINAL WAVE OF TS PUSHING EAST BY LATE MORNING.
* IFR VSBY IMPROVING TO VFR LATER THIS MORNING.
* SE WINDS BCMG SOUTH TO SW AND GUSTING TO ARND 25 KT. WINDS BCMG
WEST OVERNIGHT WITH GUSTS UP TO 30 KT.
* ANOTHER ROUND OR TWO OF THUNDERSTORMS THIS AFTERNOON AND
EVENING. SEVERE STORMS ARE POSSIBLE.
JEE
//DISCUSSION...UPDATED 12Z...
AREA OF THUNDERSTORMS WILL MOVE ACROSS THE TERMINALS OVER THE NEXT
FEW HOURS. END TIME IN THE 14Z-15Z LOOKS ON TRACK WITH ADDITIONAL
DEVELOPMENT NEAR VYS. POSSIBLE FOR ADDITIONAL ISOLATED ACTIVITY
LATE THIS MORNING INTO THIS AFTERNOON BUT CONFIDENCE IS LOW AND
WILL MAINTAIN DRY FORECAST UNTIL LATE THIS AFTERNOON...WHEN A LINE
OF STRONG/SEVERE THUNDERSTORMS IS EXPECTED DEVELOP AHEAD OF A COLD
FRONT AND MOVE ACROSS THE TERMINALS THRU EARLY THIS EVENING.
EAST WINDS WILL TURN SOUTHEAST THIS MORNING AND SOUTHERLY BY LATE
MORNING. SPEEDS/GUSTS WILL BEGIN TO INCREASE FROM THE SOUTH/
SOUTHWEST THIS AFTERNOON AND THEN BECOME STRONG THIS EVENING WITH
SPEEDS 20-25KTS POSSIBLE WITH GUSTS 30-35KTS. DIRECTIONS WILL TURN
MORE WESTERLY OVERNIGHT WITH SPEEDS DIMINISHING SOME OVERNIGHT.
CIGS/VIS ON THE DECK ARE EXPECTED TO IMPROVE QUICKLY THIS MORNING
BUT SPECIFIC HEIGHTS/TIMING IS LOW AND WILL LIKELY REQUIRE SOME
UPDATES THIS MORNING. CIGS SHOULD BECOME MVFR OR BETTER BY LATE
MORNING WITH IFR/LIFR POSSIBLE WITH THUNDERSTORMS THIS EVENING.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ROUNDS OF THUNDERSTORMS THROUGH THIS EVENING.
MEDIUM CONFIDENCE IN TIMING...COVERAGE...AND SEVERITY.
* MEDIUM CONFIDENCE IN WINDS...WINDS THIS AFTN MAY BE MORE CHAOTIC
WITH THUNDERSTORMS...AND WINDS MAY BE GUSTIER THIS EVENING AND
OVERNIGHT.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.
&&
.MARINE...
416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST
TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM
FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD
OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY
ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY
INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE
LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS
EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE
WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO
BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER
NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF
THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT
FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH
PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1007 AM CDT Thu Apr 9 2015
.UPDATE...
ISSUED AT 1007 AM CDT THU APR 9 2015
15z/10am surface analysis shows 1000mb low centered just north of
Kansas City, with warm front extending eastward into northern
Illinois. Front has now lifted north of the KILX CWA, placing the
entire area firmly in the warm sector. Widespread early morning
convection is in the process of exiting into northern Indiana,
leaving behind just scattered showers/storms for the time being.
Further upstream, the next upper-level impulse is triggering a
renewed round of convection across western Missouri. Based on
timing tools and the latest HRRR guidance, this activity will move
into the SW CWA between 17z and 18z. Once this wave departs,
attention will turn to the approaching cold front which is still
on target for a late afternoon/early evening arrival. Airmass
ahead of the front will become moderately unstable and highly
sheared, so threat for strong to severe thunderstorms is still
present. Current indications suggest the primary time frame will
be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the
main threat with the storms, although large hail and isolated
tornadoes will also be possible as the cells first begin to
develop. Made some changes to hourly PoPs to better reflect
current and expected trends, but changes were minor and did not
require a full zone update at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 303 AM CDT THU APR 9 2015
Latest surface analysis shows the warm front has lifted to the I-74
corridor early this morning with a chaotic wind field across most of
the forecast area. Not sure what the affect the current scattered
convection will have on the position of the frontal boundary thru
the morning hours, but most of the models suggest a continued slow
push to the north as the main surface low tracks northeast to
central Iowa by late this morning. Current thinking is that the cold
front will be positioned just west of the Mississippi River by 21z
with surface based convection developing ahead of the front at that
time as well. Better low level helicity fields supportive of
discrete supercells and possible tornadoes looks to be closer to the
track of the surface low...which by late afternoon is expected to be
in far southwest Wisconsin or northwest Illinois. That would put the
threat for more persistent low level rotating storms just to our
west and north. However, still plenty of shear ahead of the frontal
boundary this afternoon and early this evening to promote damaging
straight line winds as the storms transition into more of a linear
system. Temperature-wise, with the warm front to our north this
afternoon, will continue to go with the warmer guid values most
areas. Latest model data now suggests the backedge of the precip
pushes out of our far southeast counties by midnight, so will extend
the Flash Flood Watch until that time this evening.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 303 AM CDT THU APR 9 2015
Showers and thunderstorms, possibly severe, will be ongoing across
at least the eastern half of the forecast area to start this
evening. Despite the short forecast range, there is still some
spread in the expected cold frontal timing. However, it appears
reasonable that the front will lie somewhere between the Illinois
River and the I-55 corridor by 00Z Friday. Sped up the decrease in
shower/storm chances by mid evening, and I would not be surprised to
see the precipitation chances taper off a few hours earlier,
especially if the squall line gets a head of steam and trends
further ahead of the front than current progs.
Once the front clears the area tonight, quiet conditions, along with
much cooler and less humid air will build across the region into
Sunday. These conditions will be driven by a large area of high
pressure of Canadian origin. While conditions will be notably
cooler/less humid, they will still be at or above normal for early
April.
The next precipitation chances will arrive later Sunday into Sunday
night as a cold front is dragged across the area. While this front
is still expected to stall out at it begins to parallel the
upper-level flow, model trends suggest the front will stall out
further south than previously anticipated. If these trends persist,
Monday and Monday night will end up dry. For now, have reduced but
not eliminated PoPs Monday/Monday night until we see if this recent
model trend sticks.
A slow moving upper-level disturbance will push the front back into
the area by Tuesday, bringing renewed shower/storm chances. The
front and/or upper level disturbances will keep the rain chances
going into the end of the work week. Temperatures should remain at
or above normal through the period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 640 AM CDT THU APR 9 2015
Active weather day across the region with scattered thunderstorms
this morning, with storms expected to redevelop this afternoon and
evening along a cold front. Some of those storms will be severe
with damaging wind gusts and hail possible. VFR cigs expected
outside any storms, however, with any strong storm, look for cigs
and vsbys to briefly drop to IFR at times. Gradient winds are
expected to be rather gusty today out of the south and southwest
with prevailing speeds of 15 to 25 kts with gusts around 35 kts
at times. Cold front timing looks to be around the PIA site by 23z
and should be east of our TAF sites by 02z. It appears the strongest
storms will be about an hour or two ahead of the actual cold front
this afternoon and evening.
Look for sfc winds to become southwest with FROPA and with the storm
system expected to deepen, a rather tight pressure gradient will
produce a period of strong and gusty winds out of the southwest
just after the passage of the cold front late this afternoon into
the evening. Some gusts may be around 35 kts at times just after
the front shifts to the east of a TAF sites early this evening.
Expect the strong gusts to slowly subside, but not until after
03z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063-
066>068-071>073.
&&
$$
UPDATE...Barnes
SHORT TERM...Smith
LONG TERM...Bak
AVIATION...Smith
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTHERN INDIANA
325 PM EDT THU APR 9 2015
.SYNOPSIS...
ISSUED AT 1120 AM EDT THU APR 9 2015
A LOW PRESSURE CENTER IS CURRENTLY LOCATED OVER SOUTHERN IOWA AND
NORTHERN MISSOURI. THIS LOW IS MOVING A WARM FRONT AND SOME
SHOWERS AND THUNDERSTORMS THROUGH THE REGION TODAY AND WILL MOVE A
COLD FRONT AND SOME MORE SHOWERS AND THUNDERSTORMS THROUGH
TONIGHT. SOME OF THESE STORMS THIS AFTERNOON AND THIS EVENING
COULD BECOME STRONG TO SEVERE. HIGH TEMPERATURES TODAY WILL RANGE
FROM THE LOWER 70S IN SOUTHERN MICHIGAN TO THE MIDDLE 70S ALONG
THE OHIO RIVER. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE
MIDDLE 40S IN SOUTHERN MICHIGAN TO AROUND 50 NEAR THE OHIO RIVER.
&&
.SHORT TERM...(THIS EVENING AND TONIGHT)
ISSUED AT 324 PM EDT THU APR 9 2015
MULTIPLE CONVECTIVELY-ENHANCED SHORTWAVES CONTINUE TO RIPPLE THROUGH
THE REGION IN SOUTHWEST FLOW AHEAD OF MAIN TROUGH AXIS STILL WELL TO
OUR WEST. THIS HAS LED TO A MUDDLED MESOSCALE ENVIRONMENT WITH
MULTIPLE ROUNDS OF WEAK/ELEVATED CONVECTION SO FAR TODAY. DIURNAL
DESTABILIZATION HAS BEEN SLOW GIVEN ABUNDANT RAIN AND STRATUS.
STARTED TO SEE SOME BREAKS IN THE CLOUDS DURING THE LAST COUPLE
HOURS BUT STILL A LOT OF CONVECTIVE DEBRIS TO INHIBIT SURFACE
DIABATIC HEATING. LATEST RAP/SPC MESOANALYSIS SHOWS BETTER SURFACE
BASED INSTABILITY JUST NOW STARTING TO NOSE INTO OUR SOUTHWESTERN
CWA AS WARM FRONT IS PUSHED NORTHWARD BY STRENGTHENING LOW LEVEL
GRADIENT AHEAD OF APPROACHING LOW BUT RAP SOUNDINGS STILL SHOW A
SUBTLE 700-800MB INVERSION OVER MUCH OF OUR AREA THROUGH THE LATE
AFTERNOON. TWO FEATURES TO WATCH FOR SEVERE WEATHER THREAT THIS
EVENING...ONE IS A SUBTLE PREFRONTAL TROUGH CURRENTLY PUSHING
THROUGH NORTH-CENTRAL ILLINOIS AND SECOND IS THE ACTUAL COLD FRONT
ITSELF...STILL IN CENTRAL MISSOURI. FORCING IS WEAK WITH THE FIRST
WAVE BUT APPEARS TO BE ENOUGH SURFACE HEATING TO GENERATE AROUND
1000 J/KG OF MLCAPE OVER ILLINOIS. THERE IS HOWEVER A LOCAL MINIMUM
OF INSTABILITY SEEN ON RAP/SPC MESOANALYSIS OVER WESTERN INDIANA.
RAP SUGGESTS INSTABILITY IN THIS AREA WILL FILL IN OVER THE NEXT FEW
HOURS AND IF THE CLUSTER OF STORMS OVER CENTRAL ILLINOIS CAN LATCH
ONTO THAT...IT WILL BE CAPABLE OF PRODUCING SEVERE WEATHER IN OUR
AREA LATER THIS AFTERNOON. CONFIDENCE IN THIS HAPPENING IS LOW
THOUGH...GIVEN NORTHWARD DISPLACEMENT OF STORMS CURRENTLY ON RADAR
AND RELATIVELY DIFFUSE FORCING. STORMS MAY CLIP OUR NORTHWEST
COUNTIES BUT DIFFICULT TO SAY HOW MUCH INSTABILITY WILL BE LEFT BY
THAT POINT. SPC HAS ISSUED A TORNADO WATCH RIGHT UP TO OUR WESTERN
BORDER. WILL CONTINUE TO MONITOR CLUSTER OF STORMS UPSTREAM DURING
THE NEXT FEW HOURS TO SEE IF A LOCAL EXTENSION MAY BE NECESSARY BUT
FOR NOW THREAT APPEARS LOW. POTENTIAL THREAT WITH THIS FEATURE WILL
FALL IN THE 22-00Z TIMEFRAME WITH THE MAIN HAZARD BEING DAMAGING
WINDS.
SECOND FEATURE TO WATCH IS THE ACTUAL COLD FRONT. THIS FEATURE WILL
NOT ARRIVE UNTIL 03-04Z TONIGHT AND BY THEN WE LOSE ANY SURFACE
BASED INSTABILITY. MIDLEVEL LAPSE RATES ARE MODEST...AROUND 7
C/KM...BUT NOT QUITE HIGH ENOUGH TO SUPPORT A WIDESPREAD SEVERE
WEATHER THREAT. SOME DAMAGING WINDS ARE CERTAINLY POSSIBLE GIVEN
VERY STRONG LLJ WITH 850MB WINDS OVER 50 KTS BUT WILL BE CONTINGENT
UPON GETTING A SUSTAINED UPDRAFT AND ADEQUATE PRECIP LOADING. THAT
IS QUESTIONABLE AT THIS POINT. THREAT IS CERTAINLY THERE BUT IS
CONDITIONAL ON HOW MUCH INSTABILITY IS LEFT BY THE TIME IT REACHES
US. WILL CONTINUE TO MONITOR UPSTREAM TRENDS CLOSELY THROUGH THE
LATE AFTERNOON AND EVENING TO UPDATE THE FORECAST AS NECESSARY.
UPDATED GRIDS/ZFP WILL BE OUT SHORTLY.
&&
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 324 PM EDT THU APR 9 2015
PRIMARY FOCUS FOR THE LONG TERM WILL BE HIGH WINDS ON FRIDAY...
THE SFC LOW PRESSURE SYSTEM RESPONSIBLE FOR THE ACTIVE WEATHER TODAY
WILL HAVE MADE ITS WAY INTO EASTERN UPPER MICHIGAN BY FRIDAY
MORNING. THIS PUTS THE CWA LARGELY IN THE DRY SLOT AND IN THE REGION
OF CAA. ALOFT...A CLOSED 500MB LOW LIFTS FROM UPPER MICHIGAN FRIDAY
MORNING TO JUST SOUTH OF JAMES BAY BY FRIDAY NIGHT. WITH A STRONG
RIDGE ANCHORED OVER THE ATLANTIC/NEW ENGLAND STATES...A 100 KT 500MB
JET DEVELOPS OVER THE CWA AND REMAINS THROUGH AT LEAST THE EARLY
AFTERNOON. LOOKING AT MODEL SOUNDINGS...IT APPEARS WE WILL BE MIXING
TO NEAR 900MB EARLIER IN THE DAY...THEN UP AS HIGH AS 700-750MB BY
MID AFTERNOON. THINKING GUSTS WILL BE HIGHEST IN THE EARLY AFTERNOON
THEN TAPER OFF WEST TO EAST AS THE UPPER LEVEL WIND MAXIMUM AND SFC
PRESSURE RISE/FALL COUPLET MOVES NORTHEASTWARD. THINKING GUSTS TO
35-45 MPH ARE LIKELY GIVEN MIXING POTENTIAL TOMORROW...BUT WILL HOLD
OFF ON ISSUING ANY WIND ADVISORIES FOR NOW...AS WE ARE RIGHT BELOW
CRITERIA AND DO NOT WANT TO DETRACT PUBLIC ATTENTION AWAY FROM THE
THREAT OF SEVERE WEATHER THIS EVENING/OVERNIGHT. KEPT THE GOING
HEADLINE FOR THE GALE WARNING UNTIL 15Z...AS CONDITIONS ARE MORE
STABLE OVER THE LAKE.
OTHERWISE...SHORTWAVE/PV ANOMALY ROTATING AROUND THE EXITING LOW
PRESSURE MAY BRING ADDITIONAL LL MOISTURE FORCING FOR RAIN SHOWERS
FRIDAY AFTERNOON/EVENING...MAINLY IN THE NORTHERN PORTIONS OF OUR
CWA. MODELS WERE IN GREAT DISAGREEMENT AS TO THE STRENGTH OF THE
WAVE...SO FOR NOW KEPT JUST SLIGHT CHANCE POPS/RAIN SHOWERS FOR NOW.
HIGHS WILL RANGE FROM THE MID-UPPER 50S TO LOW 60S.
SATURDAY INTO SUNDAY AFTERNOON WILL BE RELATIVELY QUIET...WITH HIGH
PRESSURE SETTLING IN OVERHEAD. HIGH TEMPERATURES WILL BE COOL...WITH
HIGHS AGAIN STRUGGLING TO REACH ABOVE THE LOW 60S.
FOR THE EXTENDED PERIOD...500MB FLOW IS SOMEWHAT SPLIT BY SUNDAY
NIGHT...WITH A DEEPENING TROUGH MOVING ACROSS NORTHERN ONTARIO AND
UPPER MI/NORTHERN LOWER MI THROUGH MONDAY NIGHT...THEN A DEVELOPING
CLOSED LOW IN THE SOUTHWESTERN U.S. TAKES SHAPE MONDAY NIGHT INTO
TUE AS A RIDGE BUILDS OVER OUR CWA AND THE SOUTHEASTERN STATES. THE
LOW DEEPENS AND MOVES NORTHEASTWARD TUE NIGHT INTO THE NORTH-CENTRAL
PLAINS BEFORE PHASING INTO THE NORTHERN BRANCH WED.
FOR OUR CWA...MODELS ARE IN GENERAL AGREEMENT WITH RESPECT TO THE
COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IN
ONTARIO/UPPER MI. BOTH THE ECMWF/GFS BRING THE FRONT ACROSS OUR AREA
SUNDAY NIGHT INTO MONDAY...THOUGH THEY DIFFER WITH RESPECT TO EXACT
TIMING AND STRENGTH. AS USUAL...THE GFS IS FASTER AND SLIGHTLY
DEEPER WITH THE UPPER LEVEL TROUGH MOVING THROUGH...AND THUS THE
FRONT IS MORE ORGANIZED. THE ECMWF SHOWS A WEAKER UL TROUGH AND
CORRESPONDING SFC SYSTEM/COLD FRONT. KEPT CONSENSUS POPS FOR
NOW...WHICH DID A DECENT JOB SHOWING THE OVERALL TREND. TUESDAY
LOOKS TO REMAIN LARGELY QUIET...WITH SMALL RIDGE BUILDING OVER THE
AREA FOR THE FIRST PART OF THE DAY. SLIGHT CHANCE FOR RAIN SHOWERS
BY LATE AFTERNOON WITH NEXT APPROACHING SYSTEM.
OF COURSE...THE PHASING SYSTEMS/STREAMS ARE A COMPLETE MESS IN THE
MODEL WORLD...WITH A WHOLE HOST OF SOLUTIONS THAT COULD PLAY OUT
TUESDAY NIGHT INTO THURSDAY. JUST KEPT THE CONSENSUS POPS AND OUR
FORECASTED THUNDER AS THERE IS TOO MUCH DISAGREEMENT TO MAKE ANY
REAL IMPROVEMENTS. GOOD NEWS IS...TEMPS WARM INTO THE UPPER 60S AND
LOW 70S FOR MUCH OF THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 134 PM EDT THU APR 9 2015
SEVERAL WAVES OF CONVECTION CONTINUE TO PUSH THROUGH THE AREA IN
MOIST SOUTHWEST FLOW AHEAD OF THE MAIN TROUGH STILL WELL TO OUR
WEST. ONE CLUSTER IS CURRENTLY EXITING THE KFWA AREA AND ANOTHER
IS SET TO CLIP KSBN WITHIN THE HOUR. BRIEF REDUCTIONS TO MVFR
CATEGORY ARE EXPECTED WITH THESE SHOWERS AND THUNDERSTORMS...ALONG
WITH WIND GUSTS TO AROUND 30 KTS. SHOULD SEE A BRIEF LULL IN
ACTIVITY DURING MID TO LATE AFTERNOON BEFORE ANOTHER ROUND OF
CONVECTION ARRIVES AHEAD OF THE MAIN COLD FRONT. STILL SOME
UNCERTAINTY AS TO EXACT TIMING OF THUNDER. ALL PRECIP SHOULD EXIT
SHORTLY AFTER 06Z TONIGHT BUT STRONG CAA WILL SUPPORT SOME MVFR
STRATUS THROUGH AT LEAST THE EARLY MORNING. STRONG WINDS WILL BE
THE OTHER MAIN STORY WITH GUSTS TO 35 KTS POSSIBLE LATE TONIGHT
INTO TOMORROW WITH DEEP MIXING AND A STRONG GRADIENT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...AGD
LONG TERM...MCD
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS JACKSON KY
642 PM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 641 PM EDT THU APR 9 2015
JUST UPDATED THE GRIDS...ZONE FORECAST TEXT PRODUCT...AND
HAZARDOUS WEATHER PRODUCT TO ALL REFLECT THE CANCELLATION OF
SEVERE THUNDERSTORM WATCH 40. WITH ONLY A FEW MEAGER THUNDERSTORMS
HAVING MOVED ACROSS THE AREA SO FAR THIS EVENING...AND WITH NO NEW
STORMS EXPECTED TO AFFECT THE AREA ANY TIME SOON...THE WATCH WAS
CANCELLED. THE FLASH FLOOD WATCH IS STILL IN EFFECT. THE GRIDS
WERE ALSO FRESHENED UP A BIT USING THE LATEST OBS DATA ACROSS THE
BOARD. WILL CONTINUE TO MONITOR CURRENT CONDITIONS TO DETERMINE
WHEN TO ISSUE THE NEXT FORECAST UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 351 PM EDT THU APR 9 2015
MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN
KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH
SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR
NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO
FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY
MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED
CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST
CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE
THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH
APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL
ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE.
HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A
LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES
AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE
INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN
THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND
06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD
ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND
SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE
COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS
AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH
THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE
WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS
THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE
ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO
UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD
FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY
COOLER...DRIER AIR AND N TO NW FLOW.
THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY
REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING
HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES
TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY
AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM
TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK
FOR THE FIRST TIME THIS YEAR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 501 PM EDT THU APR 9 2015
A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON
SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY
NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND
MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS
ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS
FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO
MONDAY NIGHT.
MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY
THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW
SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH
PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD
FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY.
HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE
POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS
SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT
LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS
FOR SHOWERS AT THAT TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 641 PM EDT THU APR 9 2015
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH 9 OR 10Z
TONIGHT. BASED ON THE LATEST MODEL AND OBS DATA...SHOWERS AND
THUNDERSTORMS WILL NOT BE AFFECTING THE TAF SITES UNTIL AROUND
DAWN ON FRIDAY. A COLD FRONT WILL BE MOVING TOWARD THE AREA
OVERNIGHT...AND UNTIL IT ARRIVES...IT WILL BE DIFFICULT FOR
SHOWERS AND STORMS TO FORM UNDER THE CURRENT ATMOSPHERIC
CONDITIONS. ONCE THE STORMS DO ARRIVE...THE TAF SITES CAN EXPECTED
TORRENTIAL RAIN...FREQUENT LIGHTNING...STRONG WINDS...AND MVFR TO
POSSIBLY LIFR CONDITIONS. THE SHOWERS AND STORMS WILL MOVE
STEADILY ACROSS EASTERN KENTUCKY DURING THE DAY ON FRIDAY...AND
SHOULD BE OUT OF THE AREA BY NEAR THE END OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...AR
SHORT TERM...JVM
LONG TERM...HAL
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
502 PM EDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 351 PM EDT THU APR 9 2015
MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN
KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH
SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR
NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO
FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY
MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED
CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST
CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE
THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH
APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL
ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE.
HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A
LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES
AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE
INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN
THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND
06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD
ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND
SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE
COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS
AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH
THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE
WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS
THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE
ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO
UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD
FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY
COOLER...DRIER AIR AND N TO NW FLOW.
THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY
REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING
HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES
TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY
AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM
TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK
FOR THE FIRST TIME THIS YEAR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 501 PM EDT THU APR 9 2015
A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON
SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY
NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND
MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS
ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS
FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO
MONDAY NIGHT.
MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY
THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW
SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH
PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD
FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY.
HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE
POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS
SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT
LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS
FOR SHOWERS AT THAT TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 351 PM EDT THU APR 9 2015
THE AVIATION DISCUSSION WILL BE ISSUED SHORTLY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...JVM
LONG TERM...HAL
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
351 PM EDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 351 PM EDT THU APR 9 2015
MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN
KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH
SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR
NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO
FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY
MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED
CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST
CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE
THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH
APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL
ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE.
HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A
LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES
AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE
INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN
THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND
06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD
ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND
SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE
COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS
AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH
THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE
WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS
THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE
ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO
UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD
FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY
COOLER...DRIER AIR AND N TO NW FLOW.
THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY
REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING
HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES
TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY
AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM
TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK
FOR THE FIRST TIME THIS YEAR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 PM EDT THU APR 9 2015
THE LONG TERM DISCUSSION WILL BE ISSUED SHORTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 351 PM EDT THU APR 9 2015
THE AVIATION DISCUSSION WILL BE ISSUED SHORTLY.
&&
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...JVM
LONG TERM...HAL
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
249 PM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 1255 PM EDT THU APR 9 2015
QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. DID END
UP BUMPING THE HIGH TEMP FOR THE DAY UP A DEGREE GIVEN THE FACT
THAT WE HAVE ALREADY REACHED 80 DEGREES BY NOON. CLOUD COVER AND
STORM COVERAGE INCREASING THIS AFTERNOON COULD HELP KEEP TEMPS IN
THE LOW TO MID 80S.
UPDATE ISSUED AT 945 AM EDT THU APR 9 2015
INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS
AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED
THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE
AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL
HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO
HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD
GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB
SERVERS AND NDFD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 411 AM EDT THU APR 9 2015
EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS
AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE
NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN
RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL
BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME
ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE
TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO.
HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND
NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE
ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO
MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY
THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY
TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND
DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE
VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS
AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE
OR THE OTHER.
THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z
FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS
WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE
WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND
CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO
APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS
LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL
RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES
EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD
FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z
FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z.
JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL
TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF
TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS
WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE
WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL
WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND
RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING
NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN
THE MID AND UPPER 60S.
MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS.
IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY
RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON.
MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL
ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD
AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED
IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO
HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 534 AM EDT THU APR 9 2015
THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW
PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT
WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE
PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE
DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE.
A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND
TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR
SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO
THE 30S FOR THE MORE SHELTERED VALLEYS.
A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO
SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A
SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT
OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL
USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH
PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL
BOUNDARY.
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL
INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED
SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON
THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL
FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH
LOWS IN THE LOW TO MID 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 248 PM EDT THU APR 9 2015
ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING AND QUICKLY
MOVING NE OVER THE REGION AT THE START OF THE PERIOD. A FEW OF
THEM MAY CONTAIN IFR CONDITIONS...STRONG WINDS...AND HAIL THIS
AFTERNOON. HOWEVER...THE GREATER THREAT MAY BE A BIT FURTHER
NORTH. OUTSIDE OF PRECIP...VFR IS EXPECTED THIS AFTERNOON.
WILL LOOK FOR MAINLY VFR AND A RELATIVE LULL IN PRECIP THIS
EVENING...BEFORE A COLD FRONT MOVES IN FROM THE NW OVERNIGHT AND
BRINGS SHOWERS AND THUNDERSTORMS FOR ALL LOCATIONS. THE BULK OF
THE OVERNIGHT PRECIP IS EXPECTED TO ARRIVE FROM NW TO SE BETWEEN
ABOUT 08Z AND 12Z. CONDITIONS SHOULD DETERIORATE TO MFR AND
POSSIBLY IFR AT TIMES. PRECIP WILL THEN MOVE OUT OF THE REGION
FROM NW TO SE BETWEEN ABOUT 13Z AND 17Z...BUT CEILINGS MOSTLY IN
THE MVFR RANGE WILL LIKELY LINGER.
WIND GUSTS AROUND 20 KT FROM THE SW WILL OCCUR AT TIMES THIS
AFTERNOON...WITH GUSTINESS POSSIBLY PERSISTING INTO TONIGHT. WINDS
WILL SHIFT TO THE WEST ON FRIDAY MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1255 PM EDT THU APR 9 2015
.UPDATE...
ISSUED AT 1255 PM EDT THU APR 9 2015
QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. DID END
UP BUMPING THE HIGH TEMP FOR THE DAY UP A DEGREE GIVEN THE FACT
THAT WE HAVE ALREADY REACHED 80 DEGREES BY NOON. CLOUD COVER AND
STORM COVERAGE INCREASING THIS AFTERNOON COULD HELP KEEP TEMPS IN
THE LOW TO MID 80S.
UPDATE ISSUED AT 945 AM EDT THU APR 9 2015
INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS
AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED
THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE
AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL
HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO
HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD
GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB
SERVERS AND NDFD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 411 AM EDT THU APR 9 2015
EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS
AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE
NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN
RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL
BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME
ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE
TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO.
HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND
NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE
ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO
MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY
THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY
TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND
DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE
VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS
AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE
OR THE OTHER.
THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z
FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS
WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE
WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND
CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO
APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS
LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL
RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES
EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD
FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z
FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z.
JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL
TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF
TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS
WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE
WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL
WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND
RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING
NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN
THE MID AND UPPER 60S.
MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS.
IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY
RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON.
MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL
ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD
AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED
IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO
HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 534 AM EDT THU APR 9 2015
THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW
PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT
WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE
PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE
DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE.
A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND
TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR
SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO
THE 30S FOR THE MORE SHELTERED VALLEYS.
A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO
SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A
SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT
OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL
USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH
PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL
BOUNDARY.
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL
INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED
SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON
THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL
FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH
LOWS IN THE LOW TO MID 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 656 AM EDT THU APR 9 2015
STRONG SRLY FLOW AND MOIST UNSTABLE AIR WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION TODAY...ESPECIALLY DURING
THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE
THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH
VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE
WIDESPREAD CHANCES VERY LATE IN THE PERIOD...AFFECTING
KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z...THEN KJKL AND
KSJS AROUND 6Z OR AFTER. ONCE AGAIN...UNTIL STORMS DEVELOP...EXACT
IMPACTS ARE STILL UNCERTAIN...SO WENT WITH A GENERAL MVFR AT THIS
TIME. WITH ANY OF THESE STORMS...ESPECIALLY IN THE AFTERNOON AND
EVENING...STRONG TO DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINS
ARE A POSSIBILITY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
645 PM EDT THU APR 9 2015
.SYNOPSIS...
A WARM FRONT WILL SLOWLY LIFT NORTHWARD THROUGH VIRGINIA TONIGHT
INTO FRIDAY MORNING. A STRONG COLD FRONT CROSSES THE AREA LATE
FRIDAY...WITH HIGH PRESSURE BUILDING BACK INTO THE REGION OVER
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST SFC ANALYSIS REVEALS HIGH PRESSURE RIDGING DOWN THE MID
ATLANTIC COAST WITH A STALLED FRONTAL BNDRY OVER INTERIOR NC. A
STRONG SFC LOW IS CENTERED OVER THE MIDWEST STATES...WHILE A
POTENT MID-LEVEL SHORTWAVE TROF IS OVER THE CENTRAL PLAINS.
ONGOING CONVECTION REMAINS TO THE SOUTH OF THE STALLED BOUNDARY
(WARM FRONT) EARLY THIS EVENING AND THUS WILL CARRY ONLY LIMITED
POPS AREAWIDE THRU 10 PM OR SO. LATEST HRRR HINTS THAT CONVECTION
OVER CENTRAL NC WILL MOVE NE INTO OUR FA LATE THIS EVENING AND
OVERNIGHT AS THE WARM FRONT STARTS TO LIFT BACK NORTH...AND HAVE
ADJUSTED POPS ACCORDINGLY TO SHOW HIGH CHC/LIKELY POPS THRU THE
CENTER OF OUR FA. LOWEST POPS (~20%) WILL BE ACROSS SOUTHSIDE
HAMPTON ROADS AND COASTAL NE NC. WILL CARRY SLIGHT CHC TSTMS AS
WELL WITH LIMITED INSTABILITY. TEMPS WILL TEND TO HOLD STEADY
THIS EVENING AND OVERNIGHT BEFORE RISING PRIOR TO SUNRISE FROM
NORTH TO SOUTH WITH THE WARM FROPA. LOWS IN THE LOW 40S EASTERN
SHORE TO NR 60 FAR SOUTH.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE AFOREMENTIONED MID-LEVEL TROUGH AND ATTENDANT SURFACE LOW
OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY...SHUNTING
A SFC COLD FRONT IN OUR DIRECTION LATE FRIDAY INTO FRIDAY NIGHT.
THE LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN
THE 60S...PRECIPITABLE WATER VALUES ~+2SD...INCREASING LLVL
STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE. THIS WILL
LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON
AND EVENING ACROSS THE REGION. SPC CONTINUES TO OUTLOOK THE REGION
IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE
PRIMARY HAZARDS. THE TIMING OF THE SEVERE THREAT LOOKS TO BE LATE
AFTERNOON THROUGH EVENING AS THE FRONT PUSHES ACROSS THE AREA.
MAIN CHANGE TO PREVIOUS FORECAST WAS TO INCREASE POPS TO 70% AND
DELAY TIMING OF PRECIP A COUPLE HRS AS MOST GUIDANCE HAS SLOWED
DOWN THE SYSTM JUST A BIT...MAKING MUCH OF THE DAY THRU 18Z DRY
FOR ALL OF THE FA EXCEPT FAR WRN AREAS. QUITE WARM AS WELL...WITH
HIGHS IN THE LO TO MID 80S ALONG THE COASTAL PLAIN...UPR 70S TO
LWR 80S OTHER AREAS.
THE COLD FRONT SLIDES OFFSHORE BY SAT MORNG. HIGH PRESSURE
BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT WEEKEND TO THE
FA WITH HIGHS BOTH DAYS IN THE UPR 60S TO LWR 70S UNDER A MSTLY
SUNNY SKY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH HIGH PRESSURE OVER THE REGION
WITH DRY CONDITIONS AND SEASONABLE TEMPERATURES THROUGH MONDAY.
THE MODELS AND IN GOOD AGREEMENT ON THE THE SURFACE HIGH SLOWLY
SLIDING OFF THE COAST ON MONDAY WITH THE APPROACH OF A WEAK COLD
FRONT MONDAY NIGHT INTO TUESDAY MORNING. THE 12 ECMWF HAS MORE
MOISTURE WITH THAN THE PREVIOUS RUN AND LOOKS MORE LIKE THE GFS.
THE 12Z GFS IS A TOUCH SLOWER WITH THE FRONT..BUT STILL SHOWS GOOD
LIFT AND MOISTURE SO HAVE KEPT THE CHANCE POPS FOR LATE MONDAY
NIGHT INTO THE DAY ON TUESDAY. STILL WOULD EXPECT QPF TO BE ON THE
LOW SIDE AS THE BULK OF THE MOISTURE IS STILL OVER THE GULF COAST
STATES IN ADVANCE OF THE NEXT SYSTEM.
BY TUESDAY EVENING...SHOULD SEE THE FRONT PUSH INTO SC/GA WITH
HIGH PRESSURE SAGGING DOWN THE EASTERN SEABOARD. THE GFS AND ECMWF
SHOW A LOT LESS MOISTURE FOR WEDNESDAY INTO THURSDAY THAN PREVIOUS
RUNS...SO HAVE STARTED TO LOWER POPS DOWN TO SLIGHT CHANCE LEVELS
NOW FOR MOST OF THE AREA...BUT WOULD NOT BE SURPRISED TO SEE A DRY
DAY ON WEDNESDAY.
THE UNCERTAINTY COMES ON THURSDAY AS THE FLOW ALOFT BECOMES MORE
SOUTHWEST AND WITH A DEVELOPING TROUGH OVER THE SOUTHERN
PLAINS...SHOULD SEE GULF MOISTURE BEGINNING TO ADVECT BACK INTO
THE REGION. HAVE MAINTAINED THE CHANCE POPS FOR NOW AS TIMING MAY
BE A QUESTION...BUT EXPECT TO SEE A DECENT RAINFALL EVENT LATE
NEXT WEEK AS WAVES OF ENERGY LIFT NE AROUND THE DEVELOPING TROUGH.
FOR TEMPERATURES...HAVE GENERALLY RUN CLOSE TO THE SUPERBLEND
GUIDANCE WITH HIGHS GENERALLY IN THE 70S MOST OF THE
WEEK...ALTHOUGH DID LOWER VALUES A TOUCH ON WEDNESDAY BEHIND THE
FRONT...SO WOULD NOT BE SURPRISED TO SEE HIGH MORE IN THE MID TO
UPPER 60S ON WEDNESDAY AND POSSIBLY THURSDAY IF WEDGING SETS UP
WITH OVERRUNING CLOUDS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 17Z...NE TO E WINDS WERE KEEPING A MOIST MARINE LAYER AT THE
SURFACE WITH GENERALLY IFR CIGS. ORF AND ECG WILL BE INTERMITTENTLY
MVFR AND POSSIBLY SBY (NOT IN THE TAF) AS WELL. FOLLOWED CONSISTENCY
OF THE MOS AND BROUGHT CONDS DOWN TO LIFR/VLIFR OVERNIGHT.
S/SW WINDS DEVELOP FRIDAY MORNING AHEAD OF THE NEXT FRONT WHICH WILL
SLOWLY SCOUR OUT THE LOW LEVEL MOISTURE. SW WINDS MAY BE GUSTY
(AROUND 25 KTS) AT TIMES AFT 15Z.
SCT TSTMS...SOME STRONG...MAY IMPACT THE TAF SITES LATE FRIDAY
AFTN/EVENING. VFR AND DRY WEATHER WILL PREVAIL SATURDAY THROUGH
MONDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. THERE WILL BE A
CHANCE FOR SHOWERS ON TUESDAY.
&&
.MARINE...
STILL SEEING THE INFLUENCE OF THE HIGH PRESSURE SYSTEM OVER THE
NERN US NOSING DOWN INTO THE COASTAL WATERS THIS AFTERNOON. WIND
ARE GENERALLY 10 TO 15 KT OUT OF THE E TO NE. THIS IS SERVING TO
KEEPING THE COAST WATERS STILL IN THE 5 TO 7 FT RANGE FOR THE
NORTHERN 2 COASTAL ZONES...SO HAVE KEPT SCA ON GOING. THIS HIGH
WILL PULL OUT OF THE AREA TONIGHT AND THE FLOW WILL TURN SOUTHERLY
IN ADVANCE OF A COLD FRONT WHICH MOVES THROUGH ON FRIDAY. IN
ADVANCE OF THE FRONT WILL SEE WINDS KICK UP TO AROUND 15 TO 20 KT.
THE WINDS ALOFT WILL BE STRONGER...BUT THE COOLER WATER WILL SERVE
TO KEEP THE HIGHER WINDS OFF THE WATER SURFACE. SOME THUNDERSTORMS
ARE EXPECTED WITH THIS FRONT AND THESE STORMS COULD BRIEFLY BRING
THE STRONGER WINDS DOWN TO THE SURFACE. ONCE THE WINDS TURN NW
BEHIND THE FRONT SHOULD SLOWLY SEE THE WINDS DIMINISH LATER FRIDAY
NIGHT BACK TO 10 TO 15 KT. SO FOR NOW HAVE EXTEND THE SCA THROUGH
1 AM FRIDAY FOR SEAS OF 5 TO 7 FT.
HIGH PRESSURE BUILDS INTO THE REGION ON SATURDAY AND LINGERS
THROUGH MONDAY. THIS SHOULD BRING A PERIOD OF QUIET WEATHER WITH
THE WINDS DIMINISHING ON SUNDAY TO UNDER 10 KT.
THE NEXT FRONT TO IMPACT THE WATERS ARRIVES ON MONDAY NIGHT AS A
COLD FRONT SWINGS ACROSS THE AREA. EXPECT AN INCREASE IN SW WINDS
ON MONDAY AHEAD OF THE FRONT...BUT SHOULD REMAIN BELOW SCA LEVELS
AGAIN IN THE 15 TO 20 KT RANGE. HIGH PRESSURE RETURNS FOR THE
WEDNESDAY AND THURSDAY TIME PERIOD WITH ANOTHER PERIOD OF QUIET
WEATHER.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...MAS/MAM
LONG TERM...ESS
AVIATION...LSA
MARINE...ESS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
212 PM EDT THU APR 9 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE
TO WEAKEN TODAY...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM
FRONT THIS AFTERNOON INTO TONIGHT. ANOTHER COLD FRONT CROSSES THE
REGION LATE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS FEATURES COLD FRONT IN PLACE SOUTH OF THE LOCAL
AREA THIS MORNING. CONTINUE TO NOTE SOME VERY LIGHT RAIN/DZ AND
FOG ACROSS FAR NORTHERN ZONES, WITH MORE WIDESPREAD AREA OF SHOWERS
AND EMBEDDED TSTMS CURRENTLY PUSHING SLOWLY TO THE E-SE FROM THE
PIEDMONT INTO CENTRAL VA FOLLOWING WEAK STEERING FLOW JUST NORTH
OF THE FRONTAL ZONE. HAVE CONTINUED TO NOTE ELEVATED INSTABILITY
IN THIS AREA ATOP A STABLE/SATURATED BL. THE HRRR HAS HANDLED
THIS (AND PREVIOUS) ROUND OF CONVECTION QUITE WELL AND HAVE HEDGED
THE FORECAST IN ITS DIRECTION FOR THE FIRST PART OF THE NEAR TERM.
WILL TAKE CURRENT SWATH OF CONVECTION ACROSS CENTRAL ZONES THROUGH
08-09Z...BEFORE IT TRANSITIONS ACROSS SE VA AND OFFSHORE BY 15Z.
WITH PW VALUES WELL ABOVE CLIMO AVG (~2SD), SOME BRIEF HEAVY
DOWNPOURS REMAIN POSSIBLE THIS MORNING. OTHERWISE, AS WITH
YESTERDAY, GIVEN STABLE BL AND LITTLE IF ANY TANGIBLE IMMINENT
FORCING MECHANISM UPSTREAM, WILL GO WITH A RELATIVE LULL IN PCPN
AND A MAINLY DRY ALBEIT MAINLY OVERCAST AFTERNOON. GIVEN MOIST
AIRMASS, WILL STICK WITH A SLIGHT CHC OF SHRAS FOR THE AFTN. LOOK
FOR HIGHS IN THE MID TO UPPER 50S ACROSS THE NORTH, LOW TO MID 60S
CENTRAL ZONES, AND U60S TO MID 70S ALONG AND SOUTH OF US 58
CORRIDOR OF SOUTHERN VA/INTERIOR NE NC.
LOW PRESSURE OVER THE PLAINS WILL TRACK NE INTO THE UPPER MIDWEST
LATE TODAY INTO EARLY FRIDAY. RESULTANT DEVELOPING WEAK RIDGING
ALLOWS SW FLOW TO DEVELOP, WHICH WILL SHUNT WEAK FRONTAL ZONE
BACK NORTH BY LATE IN THE DAY. WHILE MOST OF THE AREA WILL REMAIN
IN THE STABLE/EASTERLY FLOW TODAY, EXPECT MILDER TEMPERATURES BY
AFTN ACROSS SOUTHERN TIER OF THE CWA AS FRONT BEGINS TO LIFT BACK
NORTH LATE TDA/TNGT. CONTINUED MILD ACROSS THE SOUTH TONIGHT, WITH
LOWS IN THE U50S TO L60S SOUTH, LOW TO MID 50S NORTH.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE AFOREMENTIONED UPPER TROUGH AND ATTENDANT SURFACE LOW OVER THE
GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY, SHUNTING SFC COLD
FRONT IN OUR DIRECTION FRIDAY INTO FRIDAY NIGHT. LOCAL AREA
REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE
60S...PRECIPITABLE WATER VALUES ~+2SD AND INCREASING LLVL
STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE WILL LIKELY
BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND
EVENING ACROSS THE REGION. SHOULD BE NOTED THAT THE HIGHER END OF
INSTABILITY PROFILES ABOVE 2K J/KG HAVE BEEN DISCOUNTED FOR NOW
GIVEN PREFRONTAL CLOUDS AND UNCERTAINTY OF SHRA COVERAGE EARLY
FRI MORNING. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK
OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS.
THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON
THROUGH FRI EVENING AS THE FRONT PUSHES ACROSS THE AREA. PREVIOUS
FORECAST DEPICTING CHC POPS RAMPING INTO LIKELY RANGE DURING THIS
PERIOD HAS BEEN RETAINED, WITH RAIN CHCS DROPPING OFF QUICKLY FROM
NORTHWEST TO SOUTHEAST FRIDAY NIGHT. QUITE WARM ON FRIDAY WITH A
FULL DAY OF COMPRESSIONAL HEATING ON WARM SOUTHERLY FLOW. LOOK FOR
HIGHS IN THE MID 80S ALONG THE COASTAL PLAIN, UPPER 70S TO AROUND
80 INLAND.
COLD FRONT SLIDES OFFSHORE TO BEGIN THE DAY SAT. HIGH PRESSURE
BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT START TO THE
WEEKEND WITH HIGHS IN THE U60S NORTH TO LOW 70S SOUTH UNDER A
MOSTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN
DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL
RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL
AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW
OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE
MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS.
FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS
FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT
AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE
MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD
INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES
AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED
SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING
TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE
SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST
TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE
LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP
FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST
DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE
REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S
COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT
PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE
TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO
MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO
RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 17Z...NE TO E WINDS WERE KEEPING A MOIST MARINE LAYER AT THE
SURFACE WITH GENERALLY IFR CIGS. ORF AND ECG WILL BE INTERMITTENTLY
MVFR AND POSSIBLY SBY (NOT IN THE TAF) AS WELL. FOLLOWED CONSISTENCY
OF THE MOS AND BROUGHT CONDS DOWN TO LIFR/VLIFR OVERNIGHT.
S/SW WINDS DEVELOP FRIDAY MORNING AHEAD OF THE NEXT FRONT WHICH WILL
SLOWLY SCOUR OUT THE LOW LEVEL MOISTURE. SW WINDS MAY BE GUSTY
(AROUND 25 KTS) AT TIMES AFT 15Z.
SCT TSTMS...SOME STRONG...MAY IMPACT THE TAF SITES LATE FRIDAY
AFTN/EVENING. VFR AND DRY WEATHER WILL PREVAIL SATURDAY THROUGH
MONDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. THERE WILL BE A
CHANCE FOR SHOWERS ON TUESDAY.
&&
.MARINE...
THUNDERSTORMS WILL CROSS THE WATERS THIS MORNING AND THEN COME TO AN
END ACROSS SRN COASTAL WATERS BY MID TO LATE MORNING. OTHERWISE...A
FRONT THAT CROSSED THE WATERS ON WED WILL REMAIN STALLED ACROSS THE
CAROLINAS TODAY. PERSISTENT N-NE WINDS AOB 15KT HAVE KEPT SEAS
ELEVATED BTWN 4-7FT FROM FENWICK ISLAND TO THE VA/NC BORDER. SEAS
WILL SLOWLY SUBSIDE BELOW 5FT FOR COASTAL WATERS SOUTH OF PARRAMORE
ISLAND BY THIS AFTN...AND REMAIN AROUND 5FT CLOSER TO 20NM FOR NRN
COASTAL WATERS TODAY THROUGH MOST OF FRIDAY BEFORE FALLING BELOW
5FT/SCA THRESHOLDS.
THE STALLED FRONT LIFTS NWD AS A WARM FRONT TONIGHT INTO EARLY FRI
MORNING. WINDS TONIGHT WILL BEGIN E-SE AOB 15KT AND THEN BECOME MORE
SLY BEHIND THE WARM FRONT (15-20KT COASTAL WATERS...AOB 15KT
BAY/RIVERS/SOUND). SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI
MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN
APPROACHING COLD FRONT. WINDS WILL AVERAGE 15-20KT WITH GUSTS OF 25-
30KT DURING THE AFTN. SEAS WILL AVERAGE 3-4FT TONIGHT INTO FRI
MORNING AND THEN BUILD TWD 5FT FROM PARRAMORE ISLAND TO CAPE CHARLES
LIGHT BY MID-LATE FRI MORNING. WAVES 2-3FT TONIGHT WILL THEN AVERAGE
3FT ON FRI. THE COLD FRONT CROSSES THE WATERS FRI NIGHT WITH STRONG
THUNDERSTORMS EXPECTED. MAIN IMPACTS WILL BE GUSTY AND ERRATIC
THUNDERSTORM WINDS WITH HEAVY RAINFALL. MARINERS SHOULD BE AWARE OF
RAPIDLY CHANGING CONDITIONS AND PLAN FOR A QUICK ROUTE TO SAFE
HARBOR WHEN NEEDED LATE FRI AFTN/EVENING. BEHIND THE COLD FRONT FRI
NIGHT...A COOLER AIRMASS DOES NOT ARRIVE UNTIL DURING THE DAY ON
SAT. A DAYTIME ARRIVAL OF THE COOLER AIR WILL DECREASE CHANCES FOR
POST-FRONTAL SCA WINDS. EXPECT W-N WINDS ON SAT AOB
15KT...DECREASING TO AOB 10KT SAT NIGHT AS HIGH PRESSURE BUILDS INTO
THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN
NIGHT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAS/MAM
LONG TERM...SAM
AVIATION...LSA
MARINE...BMD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
534 PM EDT THU APR 9 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 330 PM EDT THU APR 9 2015
STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING
THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY
RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A
PLEASANT WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EDT THU APR 9 2015
POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW
TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY
AFTER MIDNIGHT.
WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO
THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVR KS/NE IS
EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT
MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING
OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA.
THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING
EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING
CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO
SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY
AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT
JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN
STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS.
IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED
CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED
ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW.
THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE
UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS
PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE
WIND GUSTS AHEAD OF THE COLD FRONT.
ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH
THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS
BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN
LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY.
CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON
FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND
ADVISORY FOR LATE TONIGHT AND FRIDAY.
THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS
IN.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU APR 9 2015
WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO
WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY
OR THURSDAY BUT TIMING IS REALLY UNCERTAIN.
OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON
WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK.
SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS
THROUGHOUT NEXT WEEK.
AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY
MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES
OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH
OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION
ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT
SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE
IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY
WILL BE DRY AND SEASONABLE.
AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST
TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE
EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES.
EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM
BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE
TODAY
IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL
HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 156 PM EDT THU APR 9 2015
WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM
FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER
AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD
PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG
AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE.
EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH
MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS
FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE
SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z.
&&
.MARINE...
ISSUED AT 330 PM EDT THU APR 9 2015
WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE
DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT.
&&
.HYDROLOGY...
ISSUED AT 534 PM EDT THU APR 9 2015
2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST 15 HOURS IN PORTIONS
OF OTTAWA... KENT... AND OCEANA COUNTIES. 1 TO 2 INCHES HAS FALLEN
IN MANY LAKESHORE AND CENTRAL MICHIGAN COMMUNITIES... AND A
QUARTER INCH TO 1 INCH IN SOUTHERN MICHIGAN. A FEW RIVERS HAVE
BEGUN RISING. THE ROGUE BELOW ROCKFORD IS ALREADY ABOVE BANKFULL.
SEVERAL OTHER RIVERS ARE FORECAST TO RISE ABOVE OR CLOSE TO BANKFULL.
AS SUCH... RIVER FLOOD ADVISORIES HAVE BEEN ISSUED IN ADDITION TO
THE AREAL FLOOD ADVISORY. RIVERS WILL BE CLOSELY MONITORED TONIGHT
AS MORE RAINFALL IS EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...COBB
AVIATION...COBB
HYDROLOGY...CAS
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT THU APR 9 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 330 PM EDT THU APR 9 2015
STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING
THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY
RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A
PLEASANT WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EDT THU APR 9 2015
POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW
TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY
AFTER MIDNIGHT.
WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO
THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVR KS/NE IS
EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT
MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING
OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA.
THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING
EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING
CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO
SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY
AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT
JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN
STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS.
IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED
CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED
ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW.
THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE
UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS
PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE
WIND GUSTS AHEAD OF THE COLD FRONT.
ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH
THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS
BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN
LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY.
CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON
FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND
ADVISORY FOR LATE TONIGHT AND FRIDAY.
THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS
IN.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU APR 9 2015
WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO
WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY
OR THURSDAY BUT TIMING IS REALLY UNCERTAIN.
OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON
WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK.
SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS
THROUGHOUT NEXT WEEK.
AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY
MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES
OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH
OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION
ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT
SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE
IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY
WILL BE DRY AND SEASONABLE.
AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST
TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE
EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES.
EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM
BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE
TODAY
IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL
HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 156 PM EDT THU APR 9 2015
WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM
FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER
AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD
PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG
AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE.
EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH
MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS
FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE
SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z.
&&
.MARINE...
ISSUED AT 330 PM EDT THU APR 9 2015
WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE
DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT.
&&
.HYDROLOGY...
ISSUED AT 1245 PM EDT THU APR 9 2015
RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING
NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY
RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL
OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO
A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS
MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND
PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD
REMAIN MOSTLY WITHIN THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...COBB
AVIATION...COBB
HYDROLOGY...63
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
203 PM EDT THU APR 9 2015
LATEST UPDATE...AVIATION
.SYNOPSIS...
ISSUED AT 330 AM EDT THU APR 9 2015
A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY
AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL
SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE
TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED.
SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS
EVENING...ESPECIALLY FURTHER SOUTH.
A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE
RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY.
COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE.
CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT
CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 1145 AM EDT THU APR 9 2015
THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE
SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND
LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4
PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE
NORTH OF THE WARM FRONT.
WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING
IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR
NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY
SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND
TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST
PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD.
HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR
INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME
THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE
SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS
FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO
THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN
GENERAL.
INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT
THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS
THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED
REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER.
THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST
ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE.
THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE
CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL
MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL
SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE
NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA
UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE
WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS
MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE
SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER
WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA.
WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE
AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED
INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH
AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE
WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS
OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG
FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER
SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY
DOWN SOUTH.
WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF
OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE
POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP
HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS
POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR
THE WARM FRONT IN THE AREA.
STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT.
THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI.
THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI
MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT
SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP
AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN
DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES
THROUGH. THIS SHOULD NOT BE SIGNIFICANT.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN
NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO
BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE
NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT
FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY
AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY.
THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC
CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF
AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE
PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE
WEATHER.
THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN
STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD
BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS
SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING
THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY.
SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD
EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER
THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A
TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY
RAIN TUESDAY.
FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT
UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM
THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO.
WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES
SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER
WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES
EAST BRING INCREASED SOUTHERLY WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 156 PM EDT THU APR 9 2015
WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM
FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER
AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD
PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG
AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE.
EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH
MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS
FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE
SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z.
&&
.MARINE...
ISSUED AT 330 AM EDT THU APR 9 2015
WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR
OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP
SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT
TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN.
WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO
FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE
GRADIENT RELAXES.
&&
.HYDROLOGY...
ISSUED AT 1245 PM EDT THU APR 9 2015
RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING
NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY
RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL
OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO
A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS
MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND
PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD
REMAIN MOSTLY WITHIN THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING
FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...COBB
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EDT THU APR 9 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 330 AM EDT THU APR 9 2015
A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY
AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL
SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE
TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED.
SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS
EVENING...ESPECIALLY FURTHER SOUTH.
A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE
RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY.
COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE.
CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT
CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 1145 AM EDT THU APR 9 2015
THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE
SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND
LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4
PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE
NORTH OF THE WARM FRONT.
WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING
IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR
NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY
SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND
TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST
PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD.
HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR
INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME
THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE
SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS
FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO
THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN
GENERAL.
INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT
THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS
THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED
REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER.
THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST
ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE.
THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE
CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL
MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL
SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE
NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA
UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE
WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS
MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE
SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER
WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA.
WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE
AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED
INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH
AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE
WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS
OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG
FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER
SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY
DOWN SOUTH.
WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF
OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE
POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP
HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS
POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR
THE WARM FRONT IN THE AREA.
STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT.
THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI.
THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI
MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT
SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP
AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN
DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES
THROUGH. THIS SHOULD NOT BE SIGNIFICANT.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU APR 9 2015
IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN
NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO
BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE
NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT
FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY
AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY.
THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC
CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF
AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE
PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE
WEATHER.
THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN
STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD
BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS
SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING
THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY.
SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD
EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER
THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A
TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY
RAIN TUESDAY.
FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT
UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM
THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO.
WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES
SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER
WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES
EAST BRING INCREASED SOUTHERLY WINDS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 753 AM EDT THU APR 9 2015
FOR THE MOST PART EXPECT PERIODS OF THUNDERSTORMS INTO THIS
EVENING. LOW CLOUDS WITH IFR / MVFR CIGS WILL ALSO PREVAIL MOST OF
THE DAY. THE WARM FRONT WILL STRUGGLE TO REACH I-94 BY LATE
AFTERNOON. IF THE WARM FRONT DOES IN FACT REACH I-94 CEILINGS MAY
BECOME VFR FOR A FEW HOURS. THE STRONGEST STORMS SHOULD BE THIS
EVENING JUST AHEAD OF THE COLD FRONT.
ONCE THE COLD FRONT COMES THROUGH WINDS WILL TURN TO THE SOUTHWEST
AND INCREASE TO 20 TO 30 KNOTS. CIGS WILL REMAIN MVFR THROUGH
SUNRISE FRIDAY. SHOWERS ARE POSSIBLE IN THE COLD UNSTABLE AIR
BEHIND THE COLD FRONT.
&&
.MARINE...
ISSUED AT 330 AM EDT THU APR 9 2015
WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR
OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP
SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT
TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN.
WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO
FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE
GRADIENT RELAXES.
&&
.HYDROLOGY...
ISSUED AT 1245 PM EDT THU APR 9 2015
RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING
NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY
RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL
OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO
A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS
MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND
PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD
REMAIN MOSTLY WITHIN THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING
FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
105 PM CDT THU APR 9 2015
.UPDATE...
ISSUED AT 105 PM CDT THU APR 9 2015
UPDATED FOR AVIATION DISCUSSION BELOW
UPDATE ISSUED AT 627 AM CDT THU APR 9 2015
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD
THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS
SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY
WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA
THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI
ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH
CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE
AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN
ALL LIQUID.
THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST
AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW
WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON
THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME
PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT
ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF
ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST
SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN.
HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A
POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM
IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO
FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS
AND HAVE REMOVED.
TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE
AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE
PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND
THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE
AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST
TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL
FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST
POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT
ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW
PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME
ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED.
ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE
UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE
MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO
REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY
MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS
WITH DIURNAL HEATING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU APR 9 2015
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS
WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND
INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE
TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL
DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL
EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE
NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND
POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE
FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE
BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE
NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION
BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE
BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS
IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF
OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE.
RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY
NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE
30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR
IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL
KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL
SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 105 PM CDT THU APR 9 2015
EXPECT LOW END MVFR AND IFR CONDITIONS TO CONTINUE THROUGHOUT THE
DAY AS LOW CLOUDS AND LIGHT PRECIP MOVE INTO THE NORTHLAND AHEAD
OF AN APPROACHING LOW PRESSURE SYSTEM. THE EXCEPTION WILL BE THE
KINL SITE... WHICH HAS ALREADY ESCAPED THE CLOUD DECK AND WILL
REMAIN IN VFR TODAY. CIGS/VIS SHOULD IMPROVE TO VFR THIS
EVENING... BEFORE A COLD FRONT FROM CANADA MOVES SOUTHEAST ACROSS
THE NORTHLAND IN THE EARLY MORNING HOURS AND LOWERS CIGS/VIS
AGAIN. EXPECT GENERALLY MVFR CONDITIONS TOMORROW MORNING BEFORE
IMPROVEMENT IN THE AFTERNOON. THE FRONT WILL BRING A CHANCE OF LIGHT SNOW
BEFORE 12Z... WHICH WILL CHANGE OVER TO LIGHT RAIN OR DRIZZLE
AFTER SUNRISE. WINDS WILL SHIFT TO THE NORTH AND BECOME GUSTY
IN THE WAKE OF THE COLD FRONT PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 32 48 30 / 70 20 20 10
INL 50 30 48 28 / 10 40 10 0
BRD 49 31 51 29 / 60 20 20 10
HYR 42 31 47 27 / 90 80 30 10
ASX 38 31 45 29 / 100 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...BJT
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
100 PM CDT THU APR 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU APR 9 2015
TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD
HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE
PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO
SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC
OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB
TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C
ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL
DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF
NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF
RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN
THE SANDHILLS.
THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE
UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD
MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING
CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT
THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE
NORTHWEST AT THE SAME TIME.
THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER
40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY
EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB
WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH.
HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES
FOR LOWS IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU APR 9 2015
RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY
WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH
PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK
ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY
EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E
GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE
LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY
SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL
NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR
ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS
WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS.
WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO
EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP
THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE
DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING
FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY
FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE
RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN
PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF
MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT
CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY
AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA.
BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL
LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE
NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH
THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE
TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS
TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE
OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE
WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE
GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT
INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT
SPREAD EAST ONTO THE PLAINS.
TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR
ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD
COOL TEMPERATURES BACK BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CDT THU APR 9 2015
SNOW CONTINUES TO PUSH EAST OF THE AREA. SNOW HAS ALREADY ENDED AT
KVTN HOWEVER A LINGERING BRIEF LOW MVFR CIG IS POSSIBLE. ANOTHER
HOUR OR TWO WITH LIGHT SNOW AT KLBF. ALL SNOW SHOULD EXIT N
CENTRAL BY LATE AFTERNOON. MEANWHILE CLEARING SKIES WILL SPREAD IN
FROM THE WEST. THIS AFTERNOON NW WINDS WILL BE ON THE
INCREASE...GUSTING TO 20 TO 30 KTS...HOWEVER DECOUPLING WILL
RESULT IN LIGHT WINDS OVERNIGHT. LIGHT WINDS CONTINUE THROUGH 18Z
TOMORROW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
703 PM EDT THU APR 9 2015
.SYNOPSIS...
WARM AND HUMID WEATHER WILL PRECEDE A STRONG COLD FRONT...WHICH
WILL CROSS THE AREA LATE FRIDAY NIGHT. A FEW THUNDERSTORMS COULD
BE STRONG FRIDAY NIGHT...WITH SHOWERS LINGERING INTO SATURDAY
MORNING. DRY AND SEASONABLE CONDITIONS WILL MOVE INTO THE AREA
THROUGH THE REMAINDER OF THE WEEKEND. A WARMING TREND WILL UNFOLD
EARLY NEXT WEEK...WITH A CHANCE OF SHOWERS TUESDAY INTO WEDNESDAY
AS GULF MOISTURE MOVES INTO THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 236 PM THURSDAY...INITIAL ROUND OF SHOWERS AND
THUNDERSTORMS HAVE DISSIPATED AS AN AREA OF SUBSIDENCE IN THE WAKE
OF A PASSING IMPULSE ALOFT TEMPORARILY TAKES HOLD. DIURNAL CUMULUS
HAS DEVELOPED UPSTREAM AND WITH GOOD INSOLATION ACROSS THE PEE DEE
AND LUMBERTON AREAS THE AREA OF SUBSIDENCE WILL WEAKEN. OUTFLOW
FROM CONVECTION ACROSS COASTAL SOUTHEAST NC HAS DROPPED INTO HORRY
COUNTY... AS NOTED BY EARLIER VISIBLE SATELLITE IMAGERY. THE
BOUNDARY COUPLED WITH THE SEA BREEZE SHOULD PROVIDE A SPARK FOR
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST SC THIS
AFTERNOON. WIDELY SCATTERED STORMS ARE ALSO POSSIBLE IN THE BETTER
INSTABILITY EXPECTED ACROSS THE PEE DEE REGION.
THE EARLIER RAINFALL WILL HAVE AN IMPACT ON TODAY/S MAX TEMPERATURES
IN THE WILMINGTON AND VICINITY LOCATIONS. AS A RESULT...LOWERED
FORECAST MAX TEMPS THERE...WHILE RETAINED HIGHS IN THE 80S FOR
LBT...FLO...AND INLAND COASTAL SC LOCATIONS. WARM SOUTHWEST FLOW
TONIGHT WILL KEEP MIN TEMPERATURES ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 236 PM THURSDAY...CHIEF HEADLINES ARE A CHANGE OF AIR-MASS
INTO SATURDAY FROM WARM TO MUGGY TO DRY AND MILD...AND A SHOT AT
STRONG STORMS LATE FRIDAY AS A COLD FRONT MOVES THROUGH. SEVERE
THREAT IS NOT SUPPORTED IN DIURNAL TIMING AS IT ARRIVES BEYOND
PEAK SURFACE HEATING FRIDAY NIGHT...BUT COOLING ALOFT MAY SUPPORT
SOME HAIL. TIME-HEIGHT ANALYSIS IS NOT OVERLY IMPRESSIVE WITH
WINDS NO GREATER THAN 35 KNOTS IN THE LOWEST 8KFT...AND H8 25-30
KT BARBS. PEAK PRECIPITABLE WATER VALUES FRIDAY NIGHT AROUND 1.75
INCHES AND SOME JET SUPPORT ALOFT SHOULD OFFER A GOOD SHOT AT
RAIN FRIDAY NIGHT INTO SATURDAY MORNING FROM WEST TO EAST...AND
CLEARING THE COAST AROUND MIDDAY SATURDAY.
UPPER 80 MAXIMUMS FRIDAY INLAND...LOW 80S COASTAL INTERIOR...AND
UPPER 60S TO MIDDLE 70S BEACHES...WILL COOL TO 70S SATURDAY TO
NEAR 80 WELL INLAND...UPPER 60S TO 70 BEACHES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 236 PM THURSDAY...EXTENDED PERIOD LOOKS RATHER QUIET AS A
MODEST SOUTHWEST FLOW ALOFT PERSISTS THROUGH THE PERIOD. HIGH
PRESSURE WILL SETTLE OVER THE AREA SUNDAY AND MONDAY AND WITH
PRECIPITABLE WATER VALUES ARE BELOW ONE HALF INCH SUNDAY WITH A
SLOW INCREASE MONDAY. HAVE KEPT THESE DAYS DRY FOR THE MOST PART.
SIGNIFICANT MOISTURE INCREASE FOR TUESDAY AND WEDNESDAY AS PWS
SURGE TO IN EXCESS OF 1.5 INCHES. HOWEVER SYNOPTIC CONDITIONS SHOW
LITTLE IN THE WAY OF FORCING AND POPS WILL REMAIN IN THE SLIGHT
CHANCE CATEGORY. SIMILAR CONDITIONS FOR WEDNESDAY. FOR
THURSDAY...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT
WITH A BACKDOOR FRONT MOVING ACROSS AS A BROAD AREA OF MID LEVEL
CONFLUENCE DEVELOPS ACROSS THE MIDWEST AND GREAT LAKES. I
MAINTAINED THE POPS FOR THURSDAY AS MOISTURE REMAINS AND THE
BOUNDARY IN THE AREA. NO CHANGES TO TEMPERATURE FORECAST FROM THE
PREVIOUS FORECAST AS READINGS WILL BE JUST A LITTLE ABOVE NORMAL.
&&
.AVIATION /00Z FRIDAY THROUGH WEDNESDAY/...
AS OF 00Z...MOST OF THE CONVECTION HAS DIMINISHED...HOWEVER THERE IS ONE
MORE IMPULSE THAT WILL MOVE INTO THE WESTERN CWA IN AN HOUR OR SO.
THE HRRR MODEL HAS FAIRLY SPIRITED CONVECTION OVER THE WESTERN CWA
FOR THE NEXT SEVERAL HOURS...BUT THINK THIS MAY BE OVERDONE. WILL
KEEP ANY MENTION OF THUNDER OUT OF THE TAFS AT LBT AND FLO AT THIS
TIME. OVERNIGHT...MID AND HIGH CLOUD CONVECTIVE DEBRIS IS EXPECTED
WITH POSSIBLE MVFR FOG.
FRIDAY...AN INCREASING SOUTHWEST GRADIENT AHEAD OF A COLD FRONT WILL
GIVE US WIND GUSTS APPROACHING 25 KTS BY EARLY AFTERNOON. THERE
SHOULD BE A FAIRLY VIGOROUS LINE OF CONVECTION THAT WILL MARCH
ACROSS THE CWA FROM LATE AFTERNOON INTO THE EVENING HOURS. POSSIBLE
DAMAGING WINDS AND HAIL CAN BE EXPECTED WITH THIS LINE OF STORMS.
EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT
THROUGH MID MORNING SATURDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 236 PM THURSDAY...CONVECTION HAS RESULTED IN A VARIABLE
WIND FIELD ACROSS THE NC COASTAL WATERS EARLY THIS AFTERNOON. THE
LARGER SCALE SYNOPTIC FLOW WILL ONCE AGAIN TAKE HOLD LATER THIS
AFTERNOON WITH THE RETURN OF SOUTHERLY FLOW. SPEEDS WILL GENERALLY
RANGE FROM 10 TO 15 KNOTS DURING THE OVERNIGHT. OUTSIDE ANY
CONVECTION...SEAS ARE EXPECTED TO BE IN THE 2-4 FT RANGE THROUGH
THE NEAR TERM.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 236 PM THURSDAY...DESPITE A COLD FRONTAL PASSAGE VERY EARLY
SATURDAY JUST PRIOR TO...OR AROUND DAYBREAK THAT MAY BRING A FEW
STRONG THUNDERSTORMS...NO SMALL CRAFT ADVISORIES ARE PLANNED...AS
WINDS AHEAD OF AND BEHIND THE FRONT REMAIN MOSTLY BELOW 20 KT.
GUSTS TO 20 KT FRIDAY AFTERNOON SEEMS LIKELY WITH SEA BREEZE
ASSISTANCE...BUT SUSTAINED WINDS ARE NOT OVERLY STRONG WITH THIS
SYSTEM OUTSIDE OF TSTMS. A FEW MARINE WARNINGS ARE POSSIBLE LATE
FRIDAY NIGHT INTO EARLY SATURDAY. SEAS OF 2-3 FEET WILL BUILD TO
3-4 FEET FRIDAY NIGHT...POSSIBLY 5 FT VERY OUTER PORTION. PATCHY
SEA FOG POSSIBLE FRIDAY BUT WATERS HAVE WARMED AND CONFIDENCE IS
LOW ON ITS FORMATION.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 236 PM THURSDAY...SURFACE HIGH PRESSURE WILL MOVE FROM THE
APPALACHIANS TO WELL OFFSHORE DURING THE PERIOD. WINDS WILL RESPOND
BY VEERING FROM NORTHEAST SUNDAY TO SOUTHEAST BY MIDDAY MONDAY. THEY
WILL MAINTAIN THIS DIRECTION THROUGH THE REMAINDER OF THE PERIOD.
SPEEDS WILL BE ON THE HIGHER END OF A 10-15 KNOT RANGE SUNDAY THEN
SETTLE INTO THE ENTIRE RANGE MONDAY AND TUESDAY. SIGNIFICANT SEAS
WILL BE 2-4 FEET SUNDAY DROPPING TO 1-3 FEET LATER MONDAY AND
TUESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...SRP
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 PM CDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM CDT THU APR 9 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE ISOLATED
SHOWERS AND GUSTY WINDS THROUGH EARLY THIS EVENING. OTHERWISE A
QUIET TONIGHT AND FRIDAY.
CURRENTLY...NORTHERLY FLOW ALOFT WITH A WEAK RIDGE ACROSS THE
NORTHERN ROCKIES AND A STRONG S/WV MOVING SOUTH TOWARDS NORTHERN
MINNESOTA. LARGE CU FIELD DEVELOPING AS EXPECTED THIS AFTERNOON
AHEAD OF AN INVERTED SFC TROUGH/FRONTAL BOUNDARY NOW PUSHING SOUTH
ACROSS NORTHERN NORTH DAKOTA. A FEW SHOWERS POPPING UP WITHIN THE
CU AS THE HRRR AND 4KM WRF ADVERTISED. DOUBTFUL MUCH WILL REACH
THE GROUND BUT WILL MAINTAIN SHOWERS IN THE FORECAST NOW THROUGH
03Z. WINDS GUSTING TO AROUND 30KTS AS WE MIX TO AROUND 700MB AND
SHOULD CONTINUE UNTIL AROUND SUNDOWN...THEN DISSIPATE QUICKLY.
WINDS WILL BE ENHANCED BY THE SHOWER ACTIVITY...AIDED WITH
EVAPORATIONAL COOLING BENEATH THE CLOUD BASES AS PRECIPITATION
FALLS.
SURFACE HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS TONIGHT
CLEARING THE SKY. HIGH PRESSURE CONTINUES SOUTH AND EAST FRIDAY
ALLOWING FOR RETURN FLOW/WAA INTO THE REGION. DECENT DAY FRIDAY
WITH HIGHS IN THE 50S AND A RELATIVELY LIGHT WIND AND MOSTLY SUNNY
SKY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM CDT THU APR 9 2015
THE MAIN FORECAST ISSUES IN THE LONG TERM INCLUDE STRONG AND GUSTY
NORTHWEST WINDS SUNDAY - WITH POTENTIAL FIRE WEATHER ISSUES - AND AN
UPPER LEVEL LOW/TROUGH SETTING UP FOR NEXT WEDNESDAY/THURSDAY.
FRIDAY NIGHT AND SATURDAY: HIGH PRESSURE EXITS THE AREA TO THE EAST
AS LOW PRESSURE DEVELOPS IN THE LEE OF THE ROCKIES AND APPROACHES
NORTH DAKOTA. BY SATURDAY AFTERNOON AN UPPER LEVEL TROUGH EXPANDS
EASTWARD AND SOUTHWEST FLOW ALOFT IS ESTABLISHED OVER THE NORTHERN
PLAINS. MEANWHILE A SURFACE WARM FRONT IS EXPECTED TO ENTER WESTERN
NORTH DAKOTA...WITH HIGHS REACHING THE UPPER 60S AND LOWER 70S.
SATURDAY NIGHT: UPPER LEVEL ENERGY REACHES NORTH DAKOTA AHEAD OF AND
ALONG AN ASSOCIATED COLD FRONT. CHANCE OF SHOWERS...MAINLY NORTH AND
WEST.
SUNDAY: THE COLD FRONT PUSHES SOUTHEAST ACROSS THE STATE EARLY
SUNDAY MORNING...WITH STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH
GUSTS TO 40 MPH POSSIBLE. SEE THE FIRE WEATHER DISCUSSION BELOW FOR
FIRE WEATHER CONCERNS.
MONDAY AND TUESDAY SHOULD BE DRY WITH HIGHS IN THE 60S MONDAY...AND
65 TO 75 TUESDAY.
THE NEXT UPPER LEVEL TROUGH MOVES ACROSS THE ROCKIES AND EMERGES IN
THE WESTERN PLAINS TUESDAY NIGHT...CROSSING THE PLAINS WEDNESDAY AND
THURSDAY. CHANCES OF RAIN SHOWERS INCREASE DURING THIS TIME...WITH
HIGHS 50 TO 60 WEDNESDAY...AND UPPER 40S TO LOWER 50S THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 323 PM CDT THU APR 9 2015
VFR CONDITIONS ALL TERMINALS THROUGH THE 18Z TAF PERIOD. LARGE
BUT SHALLOW CUMULUS CANOPY ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON ALONG WITH ISOLATED LIGHT RAIN SHOWER ACTIVITY.
GUSTY NORTHWEST WINDS SUSTAINED NEAR 20KTS AND GUSTS TO 30 KTS
WILL BE COMMON THIS AFTERNOON THROUGH EARLY EVENING. WINDS WILL
DIMINISH AROUND AND AFTER SUNSET...WITH THE CUMULUS DISSIPATING
AS WELL WITH SKC TO FOLLOW TONIGHT. WILL INCLUDE A VCSH FOR
KDIK-KBIS-KJMS WHERE IT APPEARS THE CU FIELD LINGER THE LONGEST
THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 323 PM CDT THU APR 9 2015
SUNDAY: STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH
POSSIBLE. HIGHS OF 55 TO 60 EXPECTED...WITH MINIMUM RELATIVE
HUMIDITY VALUES AROUND 20 PERCENT SOUTHWEST TO AROUND 25 PERCENT
NORTHWEST AND CENTRAL. WILL CONTINUE TO MONITOR FOR POSSIBLE FIRE
WEATHER WATCH. RECENT RAIN AND SNOWFALL OVER THE REGION IS
NOTED...AND WEATHER DORMANT GRASSES WILL HAVE TIME TO DRY OUT IS THE
MAIN QUESTION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...NH
AVIATION...NH
FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1226 PM CDT THU APR 9 2015
.UPDATE...
ISSUED AT 1226 PM CDT THU APR 9 2015
FORECAST ON TRACK...NO CHANGES FROM PREVIOUS FORECAST ISSUANCE. CU
FIELD DEVELOPMENT UNDERWAY...AND SHOULD CONTINUE OVER THE NEXT FEW
HOURS.
UPDATE
ISSUED AT 1022 AM CDT THU APR 9 2015
LAST FEW RUNS OF THE HRRR ALONG WITH THE 4KM WRF ALL INDICATE
ISOLATED SHOWERS DEVELOPING THIS AFTERNOON SO HAVE ADDED THIS INTO
THE FORECAST. KEPT QPF AT ZERO AS ONLY EXPECTED TRACE AMOUNTS OF
MOISTURE.
OTHERWISE THE INHERITED FORECAST IN GOOD SHAPE. CU FIELD SHOULD
DEVELOP BY EARLY TO MID AFTERNOON ALONG TO AHEAD OF A SFC COLD
FRONT MOVING SOUTH THROUGH NORTH DAKOTA TODAY. WINDS STILL LOOK
BREEZY...ESPECIALLY MID TO LATE DAY WHEN WE ARE PROJECTED TO MIX
OUT TO AROUND 700MB. ANY SHOWER ACTIVITY WILL AID IN GUSTY WINDS
WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES.
UPDATE ISSUED AT 630 AM CDT THU APR 9 2015
PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A
SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY.
OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS
THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT
DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU APR 9 2015
HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW
ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY
THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP
AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS
AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH
DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE
CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH
OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT
MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE
WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE
CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER
TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS
EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS
AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM
TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT
RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW
POPCORN SHOWERS THIS AFTERNOON.
FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION
CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS
SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST.
CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS
ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT
EAST THROUGH THE EARLY MORNING.
THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH
UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A
NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH
DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE
FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH
MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF
SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z
THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z
FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE.
EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING
TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA
BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO
THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF
AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM
WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS
THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT
AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR
THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL
SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A
CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND
DISSIPATE QUICKLY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU APR 9 2015
THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE
PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN
U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW
POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE
BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS
COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO
NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE
ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW
AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND
SOLUTION.
FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT
FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER
RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER
AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE
WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL
RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE
RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF
THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN
EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME.
A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS
LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER
LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL
PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND
BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE
TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH
TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE
SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE
SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL
RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES
SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH
STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO
MONITOR.
LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE
APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT
SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON
THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE
WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE
REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM
AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL
UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD
MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S.
TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY
AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND
HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN
STORE MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1226 PM CDT THU APR 9 2015
ALL TERMINALS WILL REMAIN VFR TODAY AND TONIGHT. A FAIRLY LARGE
BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL
NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY
NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS
AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS
DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. WILL
INCLUDE A VCSH FOR SOME TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...NH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
625 PM EDT THU APR 9 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT AND
DRAG A COLD FRONT THROUGH THE AREA. A SECONDARY COLD FRONT WILL
DROP ACROSS THE AREA FRIDAY EVENING. HIGH PRESSURE WILL BUILD IN
FOR SATURDAY AND SUNDAY
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
UPDATED FORECAST TO ALLOW FOR A LITTLE SUNSHINE IN NW OHIO. THE
LOCAL AREA IS CURRENTLY PRETTY QUIET. WILL HAVE TO WAIT AND SEE IF
CONVECTION NEAR CINCINNATI HOLDS TOGETHER. OTHER STORMS COULD ALSO
DEVELOP THIS EVENING IN THE WEST BUT EXPECTED THE BRUNT OF THE
PRECIP TONIGHT TO OCCUR AFTER MIDNIGHT AS COLD FRONT APPROACHES.
PREVIOUS...USED A MIX OF THE HRRR AND SREF FOR TRENDS THROUGH THE EVENING
AND OVERNIGHT. RAIN ACROSS NORTHERN OHIO SHIFTING NORTHEAST
QUICKLY AND IS NOW MAINLY IN NERN OHIO AND NWRN PA. ANOTHER AREA
OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE SOUTHERN AND
EASTERN COUNTIES THROUGH THE EVENING AS WELL. NOT A LOT OCCURRING
IN THE WESTERN HALF OF THE AREA ALTHOUGH DO EXPECT SCATTERED
CONVECTION WILL DEVELOP/MOVE IN. THROUGH THE EARLY EVENING WILL
SHIFT HIGH POPS NORTH OF THE AREA FOR A SHORT WHILE DROPPING MOST
TO CHANCE. AFTER MIDNIGHT COLD FRONT MOVES IN FROM THE WEST.
EXPECT SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY.
WILL HAVE CAT POPS COMING BACK FOR THE OVERNIGHT AND THEN WILL
ATTEMPT TO MOVE THIS EAST DURING THE EARLY MORNING HOURS WHILE
ALSO MOVING DRYING IN FROM THE WEST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
FRIDAY MORNING 12Z THE COLD FRONT SHOULD BE JUST EAST OF KCLE WITH
DRYING MOVING IN FROM THE WEST. WILL HANG ONTO A CHANCE OF THUNDER
EAST THROUGH THE FIRST HALF OF THE MORNING BUT EXPECT PRECIP TO
END BY LATE MORNING. WILL ALLOW FOR SS TO BREAK THROUGH DURING THE
DAY BUT AM STILL A BIT SKEPTICAL GIVEN LOW LEVEL RH REMAINING
ACROSS THE AREA. ANOTHER BIG CONCERN FOR FRIDAY WILL BE WINDS.
850MB FLOW INCREASES TO 50 KNOTS ACROSS THE AREA LATE TONIGHT WITH
40-45 KNOTS AT 925MB. THIS CONTINUES POST COLD FRONT. AT THIS TIME
IT DOESNT LOOK LIKE WARNING LEVELS WILL BE REACHED BUT COULD
REQUIRE A WIND ADVISORY. IF THIS CONTINUES WILL LIKELY ISSUE ON
THE EVENING OR OVERNIGHT FORECAST PACKAGE. BOTH THE NAM AND GFS
CONTINUE TO SHOW A SECONDARY COLD FRONT/UPPER SHORT WAVE MOVING
THROUGH DURING THE EVENING AND EARLY OVERNIGHT FRIDAY NIGHT. WILL
BRING CLOUDS BACK AS WELL AS A SMALL CHANCE POPS. DRY AIR AND HIGH
PRESSURE BUILD IN FOR SATURDAY AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS GENERALLY AGREE WITH WEAK COLD FRONT PUSHING SE ACROSS THE
AREA MON SO WILL MAINTAIN DECENT THREAT FOR SHRA. THE FRONT IS SHOWN
TO MOVE FAR ENOUGH SOUTH OF THE AREA TO PROBABLY ALLOW FOR DRY
CONDITIONS ON TUE WITH WEAK HIGH PRESSURE OVER THE AREA. WED THRU
FRI...A SLOW MOVING UPPER LOW OVER THE PLAINS WILL DRIFT NE CAUSING
A LOW TO LIFT NE TOWARD LAKE MICHIGAN BY LATE FRI. THE STALLED
FRONT WILL SLOWLY LIFT NORTH INTO THE REGION AS A WARM FRONT
PROVIDING A FOCUS FOR SHRA AND TSRA TO START SPREADING NE OVER THE
AREA WED INTO WED NIGHT AND CONTINUE ON THU...AND PROBABLY FOR
SEVERAL MOVE DAYS AFTER THAT. TEMPS UNCERTAIN AS THE NORTHERN PART
OF THE CWA MAY SEE NE WINDS AHEAD OF THE FRONT THUS PRODUCING A COOL
FLOW OFF OF LAKE ERIE WHILE THE SOUTHERN COUNTIES HAVE A GOOD CHANCE
OF SEEING TEMPS WELL INTO THE 60S ANY MAYBE SOME 70S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
ROUNDS OF SHRA/TSRA WILL CONTINUE TO AFFECT THE AREA INTO FRI
MORNING UNTIL A COLD FRONT SWEEPS ACROSS THE AREA TO END THE THREAT.
WIDESPREAD VFR SHOULD BE THE PREDOMINATE CONDITIONS OUTSIDE OF THE
CONVECTION WITH AREAS OF MVFR/LOCAL IFR IN THE HEAVIER TSRA. SOUTH
TO SSW WINDS WILL INCREASE THIS AFTERNOON AND TONIGHT TO BE GUSTING
25 TO 35 KNOTS TONIGHT WITH GUSTS AROUND 40 KNOTS ON FRI. THE
STRONGER TSRA CAN EASILY PRODUCE GUSTS TO 50 KNOTS WITH SOME LARGE
HAIL POSSIBLE.
.OUTLOOK..SOME NON VFR POSSIBLE ACROSS NRN OH/NW PA LATE FRIDAY AND
FRI NIGHT THEN JUST NW PA FOR EARLY SATURDAY MORNING. NON VFR
POSSIBLE AGAIN FOR MONDAY.
&&
.MARINE...
A STRONG COLD FRONT SWEEPING ACROSS LAKE ERIE LATE TONIGHT AND
FRIDAY MORNING AND THE FOLLOWING COLD ADVECTION SHOULD BE ABLE TO
PRODUCE GALE FORCE WINDS FOR A WHILE. WILL GO WITH LOW END GALES FOR
A WHILE ON FRI. THE PRESSURE GRADIENT STARTS TO WEAKEN LATER
FRI INTO FRI NIGHT SO WINDS SHOULD SLOWLY START DIMINISHING THEN
BECOME LIGHT BY SAT EVE AS HIGH PRESSURE MOVES ACROSS OHIO INTO PA.
A RETURN SOUTHERLY FLOW SHOULD SET UP IN THE WAKE OF THE HIGH FOR
SUN INCREASING TO ABOUT 10 TO 20 KNOTS FOR SUN NIGHT AHEAD OF A WEAK
COLD FRONT THAT CROSSES THE LAKE MON. WEAK HIGH PRESSURE QUICKLY
BUILDS IN BY MON NIGHT SO WINDS WILL DIMINISH AND SHOULD STAY FAIRLY
LIGHT THRU TUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ029>032-
036>038-047.
PA...NONE.
MARINE...GALE WARNING FROM 6 AM TO 4 PM EDT FRIDAY FOR LEZ061-142>149-
162>169.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
340 PM EDT THU APR 9 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT AND
DRAG A COLD FRONT THROUGH THE AREA. A SECONDARY COLD FRONT WILL
DROP ACROSS THE AREA FRIDAY EVENING. HIGH PRESSURE WILL BUILD IN
FOR SATURDAY AND SUNDAY
&&
.NEAR TERM /THROUGH TONIGHT/...
USED A MIX OF THE HRRR AND SREF FOR TRENDS THROUGH THE EVENING AND
OVERNIGHT. RAIN ACROSS NORTHERN OHIO SHIFTING NORTHEAST QUICKLY
AND IS NOW MAINLY IN NERN OHIO AND NWRN PA. ANOTHER AREA OF
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE SOUTHERN AND
EASTERN COUNTIES THROUGH THE EVENING AS WELL. NOT A LOT OCCURRING
IN THE WESTERN HALF OF THE AREA ALTHOUGH DO EXPECT SCATTERED
CONVECTION WILL DEVELOP/MOVE IN. THROUGH THE EARLY EVENING WILL
SHIFT HIGH POPS NORTH OF THE AREA FOR A SHORT WHILE DROPPING MOST
TO CHANCE. AFTER MIDNIGHT COLD FRONT MOVES IN FROM THE WEST.
EXPECT SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY.
WILL HAVE CAT POPS COMING BACK FOR THE OVERNIGHT AND THEN WILL
ATTEMPT TO MOVE THIS EAST DURING THE EARLY MORNING HOURS WHILE
ALSO MOVING DRYING IN FROM THE WEST.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
FRIDAY MORNING 12Z THE COLD FRONT SHOULD BE JUST EAST OF KCLE WITH
DRYING MOVING IN FROM THE WEST. WILL HANG ONTO A CHANCE OF THUNDER
EAST THROUGH THE FIRST HALF OF THE MORNING BUT EXPECT PRECIP TO
END BY LATE MORNING. WILL ALLOW FOR SS TO BREAK THROUGH DURING THE
DAY BUT AM STILL A BIT SKEPTICAL GIVEN LOW LEVEL RH REMAINING
ACROSS THE AREA. ANOTHER BIG CONCERN FOR FRIDAY WILL BE WINDS.
850MB FLOW INCREASES TO 50 KNOTS ACROSS THE AREA LATE TONIGHT WITH
40-45 KNOTS AT 925MB. THIS CONTINUES POST COLD FRONT. AT THIS TIME
IT DOESNT LOOK LIKE WARNING LEVELS WILL BE REACHED BUT COULD
REQUIRE A WIND ADVISORY. IF THIS CONTINUES WILL LIKELY ISSUE ON
THE EVENING OR OVERNIGHT FORECAST PACKAGE. BOTH THE NAM AND GFS
CONTINUE TO SHOW A SECONDARY COLD FRONT/UPPER SHORT WAVE MOVING
THROUGH DURING THE EVENING AND EARLY OVERNIGHT FRIDAY NIGHT. WILL
BRING CLOUDS BACK AS WELL AS A SMALL CHANCE POPS. DRY AIR AND HIGH
PRESSURE BUILD IN FOR SATURDAY AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS GENERALLY AGREE WITH WEAK COLD FRONT PUSHING SE ACROSS THE
AREA MON SO WILL MAINTAIN DECENT THREAT FOR SHRA. THE FRONT IS SHOWN
TO MOVE FAR ENOUGH SOUTH OF THE AREA TO PROBABLY ALLOW FOR DRY
CONDITIONS ON TUE WITH WEAK HIGH PRESSURE OVER THE AREA. WED THRU
FRI...A SLOW MOVING UPPER LOW OVER THE PLAINS WILL DRIFT NE CAUSING
A LOW TO LIFT NE TOWARD LAKE MICHIGAN BY LATE FRI. THE STALLED
FRONT WILL SLOWLY LIFT NORTH INTO THE REGION AS A WARM FRONT
PROVIDING A FOCUS FOR SHRA AND TSRA TO START SPREADING NE OVER THE
AREA WED INTO WED NIGHT AND CONTINUE ON THU...AND PROBABLY FOR
SEVERAL MOVE DAYS AFTER THAT. TEMPS UNCERTAIN AS THE NORTHERN PART
OF THE CWA MAY SEE NE WINDS AHEAD OF THE FRONT THUS PRODUCING A COOL
FLOW OFF OF LAKE ERIE WHILE THE SOUTHERN COUNTIES HAVE A GOOD CHANCE
OF SEEING TEMPS WELL INTO THE 60S ANY MAYBE SOME 70S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
ROUNDS OF SHRA/TSRA WILL CONTINUE TO AFFECT THE AREA INTO FRI
MORNING UNTIL A COLD FRONT SWEEPS ACROSS THE AREA TO END THE THREAT.
WIDESPREAD VFR SHOULD BE THE PREDOMINATE CONDITIONS OUTSIDE OF THE
CONVECTION WITH AREAS OF MVFR/LOCAL IFR IN THE HEAVIER TSRA. SOUTH
TO SSW WINDS WILL INCREASE THIS AFTERNOON AND TONIGHT TO BE GUSTING
25 TO 35 KNOTS TONIGHT WITH GUSTS AROUND 40 KNOTS ON FRI. THE
STRONGER TSRA CAN EASILY PRODUCE GUSTS TO 50 KNOTS WITH SOME LARGE
HAIL POSSIBLE.
.OUTLOOK..SOME NON VFR POSSIBLE ACROSS NRN OH/NW PA LATE FRIDAY AND
FRI NIGHT THEN JUST NW PA FOR EARLY SATURDAY MORNING. NON VFR
POSSIBLE AGAIN FOR MONDAY.
&&
.MARINE...
A STRONG COLD FRONT SWEEPING ACROSS LAKE ERIE LATE TONIGHT AND
FRIDAY MORNING AND THE FOLLOWING COLD ADVECTION SHOULD BE ABLE TO
PRODUCE GALE FORCE WINDS FOR A WHILE. WILL GO WITH LOW END GALES FOR
A WHILE ON FRI. THE PRESSURE GRADIENT STARTS TO WEAKEN LATER
FRI INTO FRI NIGHT SO WINDS SHOULD SLOWLY START DIMINISHING THEN
BECOME LIGHT BY SAT EVE AS HIGH PRESSURE MOVES ACROSS OHIO INTO PA.
A RETURN SOUTHERLY FLOW SHOULD SET UP IN THE WAKE OF THE HIGH FOR
SUN INCREASING TO ABOUT 10 TO 20 KNOTS FOR SUN NIGHT AHEAD OF A WEAK
COLD FRONT THAT CROSSES THE LAKE MON. WEAK HIGH PRESSURE QUICKLY
BUILDS IN BY MON NIGHT SO WINDS WILL DIMINISH AND SHOULD STAY FAIRLY
LIGHT THRU TUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ029>032-
036>038-047.
PA...NONE.
MARINE...GALE WARNING FROM 6 AM TO 4 PM EDT FRIDAY FOR LEZ061-142>149-
162>169.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
253 PM EDT THU APR 9 2015
.SYNOPSIS...
ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. COLD FRONT
CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES
AND THEN STALLS FOR UNSETTLED WEATHER NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
YET ANOTHER CONVECTIVE COMPLEX DEVELOPING TO OUR WEST...HOWEVER
THE MEAN FLOW TODAY LOOKS TO KEEP THE STRONGEST STORMS TO OUR
WEST...OR JUST CLIPPING THE WESTERN CWA. THE HIGHEST ML CAPE
REMAINS WEST OF CWA...AND WOULD EXPECT STRONGEST STORMS TO STICK
CLOSER TO THIS. WE ARE STILL FIRMLY WITHIN THE WARM SECTOR
HOWEVER WITH CONVECTION POPPING UP ACROSS WV SOUTHWEST INTO
SOUTHERN KENTUCKY...SO WILL STILL HAVE SHOWERS AND THUNDERSTORMS
DRIFTING NE ACROSS FORECAST AREA THIS AFTERNOON...INTO THIS
EVENING ACROSS THE NORTH. THINK THE BEST CHANCE OF WIDESPREAD
SEVERE THUNDERSTORMS WILL REMAIN MOSTLY WEST OF FORECAST AREA. IN
CWA BEST CHANCE LOOKS TO BE IN THE WESTERN THIRD OF CWA...ALONG
THE OHIO RIVER AND WEST THIS AFTERNOON INTO EVENING. USED THE HRRR TO
TIME THE BEST POPS...ALTHOUGH ISOLATED TO SCATTERED CONVECTION IS
TOUGH TO GET EXACT. LOW TO MID LEVEL FLOW IS GENERALLY OUT OF THE
SOUTHWEST...20-30KTS AROUND 925 MB...UP TO 50-60KTS AT 500MB. THIS
WILL KEEP THINGS MOVING WHICH SHOULD HELP WITH WATER CONCERNS.
MAIN CONCERN WATER-WISE WILL BE TRAINING CELLS...ESPECIALLY ALONG
ANY OUTFLOW BOUNDARIES THAT LINGER PARALLEL TO THE FLOW. NO REASON
TO MAKE ANY CHANGES TO THE FLASH FLOOD WATCH. IN THE WETTER
AREAS...THAT WERE HIT LAST NIGHT BY HEAVY RAIN...IT WOULD LIKELY
ONLY TAKE 1-1.5 INCHES IN 3 HOURS OR LESS TO START CAUSING
PROBLEMS AGAIN...WHILE AREAS THAT HAVE NOT RECEIVED AS MUCH RAIN
OVER THE LAST DAY OR TWO IT WOULD TAKE 1.5-2 IN 3 HOURS.
TRIED TO SHOW A BREAK LATE THIS EVENING INTO TONIGHT...AS
CONVECTION FROM THIS AFTERNOON EXITS TO THE NE...AND A COLD FRONT
FINALLY APPROACHES FROM THE WNW. STILL HAVE ISOLATED
SHOWERS/STORMS MENTIONED THROUGH THE NIGHT...AS WE REMAIN IN THE
WARM SECTOR.
COLD FRONT ARRIVES TO WESTERN ZONES FRIDAY MORNING. GFS/ECMWF ARE
FAIRLY SIMILAR IN TIMING WITH THE FRONT...WHILE NAM LAGS BEHIND A
BIT. DID NOT CHANGE PREVIOUS FORECAST TIMING A WHOLE LOT...BUT DID
INCREASE POPS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
CURRENT FORECAST OF A DRY AND MILD WEEKEND CONTINUES ONT RACK...AS
MODELS VERY CONSISTENT WITH HIGH PRESSURE DOMINATING THE OHIO
VALLEY. LOOK FOR NEAR SEASONAL DAYTIME TEMPERATURES BUT CHILLY
NIGHTS WITH A LARGE DIURNAL RANGE IN TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS DEPICT ANOTHER FRONTAL SYSTEM MEANDERING BACK AND FORTH ACROSS
OUR REGION FOR MUCH OF NEXT WEEK. WHILE SPECIFIC DETAILS MAY BE
DIFFERENT FOR EACH SYSTEM THAT RUNS ALONG THIS FRONT...THE GENERAL
SCENARIO IS FOR WARM...MOIST AND RELATIVELY UNSTABLE AIR IN PLACE
TO PRESENT A CHANCE OF SHOWERS AND THUNDERSTORMS ANYTIME FOR MUCH OF
THE WEEK.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
ISOLATED TO SCATTERED SHOWERS AND STORMS EXPECTED TODAY INTO
TONIGHT. HARD TO TIME THESE INDIVIDUAL CELLS WITH NO REAL SURFACE
FEATURE TO FOCUS ON...SO WENT WITH VCTS AND ANTICIPATE AMENDMENTS
WILL BE NEEDED IF CELLS APPROACH INDIVIDUAL TAF SITES. MVFR TO IFR
WOULD BE POSSIBLE. BETTER CONFIDENCE ON TIMING OF SHOWERS AND
STORMS FRIDAY MORNING AS A COLD FRONT PASSES THROUGH. WINDS WILL
GENERALLY BE OUT OF THE S/SW THROUGH TONIGHT...ALTHOUGH VARIABLE
AND GUSTY IN AND AROUND CONVECTION. WINDS WILL BECOME WESTERLY
BEHIND THE FRONT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H M H H H H H H H H
HTS CONSISTENCY H M M M H H H H H H H H
BKW CONSISTENCY H H H H H H H H H M M M
EKN CONSISTENCY H H H H H M M H H M M M
PKB CONSISTENCY H H H M M M H H H H H H
CKB CONSISTENCY H H H H H H M H H H H H
AFTER 18Z FRIDAY...
IFR IN SHOWERS/STORMS COULD STILL BE LINGERING ACROSS EAST FRIDAY
AFTERNOON.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013-
014-017-019-020.
FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018-
024>032-037>040-046-047.
OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075-
076-083>087.
KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ
NEAR TERM...MZ
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
412 PM EDT THU APR 9 2015
.SYNOPSIS...
STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE
CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS
OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH
THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT
ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST OF CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR
DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN
MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND
SOUTH. WIDESPREAD LOW CLOUDS WILL PERSIST INTO THE
OVERNIGHT...WITH THE EXCEPTION BEING THE FAR WESTERN STRIPE OF
ZONES WHERE SOME MIXING HAS ALLOWED FOR PARTIAL SUNSHINE TO
DEVELOP. THIS WILL BE REPLACED BY UPSTREAM CLOUDINESS BEFORE TOO
LONG AS SHOWERS CONTINUE TO MOVE OUT OF THE OHIO VALLEY.
LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN
STRONGLY DAMMED. HOWEVER...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING THROUGH EASTERN OHIO AND THE HRRR TIMES THEM INTO
MY WESTERN ZONES BETWEEN ABOUT 5 AND 8 PM. WHETHER WIDESPREAD
THUNDER MANAGES TO SURVIVE THE TREK INTO THE STABLE AIRMASS
REMAINS TO BE SEEN BUT I HAVE USED THE HRRR TO BRING A PERIOD OF
RAIN ACROSS MOST OF MY FCST AREA THIS EVENING THROUGH AROUND
MIDNIGHT...WITH STILL A GOOD CHANCE OF ADDITIONAL SHOWERS THROUGH
MORNING AHEAD OF THE APPROACHING FRONT.
OVERNIGHT LOWS FROM NEAR 40 EAST TO AROUND 50 IN THE WEST WILL BE
ANYWHERE FROM ABOUT 5 TO AS MUCH AS 20 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD
FRONT PRETTY MUCH BISECTING THE FCST AREA BY EARLY AFTERNOON. THE
GEFS DEVELOPS SLIGHTLY MORE INSTABILITY THAN DOES THE SREF...BUT
IF EITHER MODEL FAVORS AN AREA FOR SEVERE STORMS TOMORROW IT
WOULD BE OVER SERN PA DURING THE AFTERNOON AS THE FRONT PROGRESSES
EAST. AS IS OFTEN THE CASE IN PA...THE AMOUNT OF CLOUDCOVER WILL
HAVE MUCH TO SAY ABOUT THE SEVERE POTENTIAL. SPC DOES HAVE MY FAR
SERN ZONES OUTLOOKED FOR A SLIGHT RISK WHICH AT THIS RANGE LOOKS
REASONABLE.
TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S
ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
COLD FRONT EXITING TO THE SOUTHEAST BY FRI NIGHT...WILL BE
FOLLOWED BY A RATHER STRONG SMALL UPPER LEVEL TROUGH FRIDAY NIGHT
INTO SAT. DYNAMICS LOOK STRONG ENOUGH TO MAINTAIN CHANCE FOR
SHOWERS...TAPERING BACK TO SPRINKLES ON SAT AS THEY MOVE AWAY.
ANY SHOWERS WILL BE ON THE LIGHT SIDE.
BREEZY WITH A QUICK SHOT OF COOLER AIR ON SAT...THEN WARMER AIR
RETURNS ON SUNDAY INTO MONDAY AS RIDGE BUILDS IN.
MENTION OF POPS RETURNS LATE MONDAY INTO TUE AS ANOTHER FRONT
TRACKS ACROSS THE REGION. AGAIN...PRECIP AMOUNTS LOOK TO REMAIN ON
THE LIGHT SIDE.
SHARP RIDGE BUILDS IN FOR MID/LATE WEEK AS SOUTHERLY WINDS BRING A
PERIOD OF MILD WEATHER. WEAKENING SYSTEM OVER THE UPPER MIDWEST
MAY BRING SHOWERY WEATHER BACK INTO PA FOR THU/FRI.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR
CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT.
SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN
TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND
THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE
LATE AFTERNOON AND EVENING.
LLWS IS POSSIBLE THIS EVENING AS SFC WINDS REMAIN OUT OF THE
SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE
SOUTHWEST AT 30-50KT.
A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE
LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL
FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR
CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING.
ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ
VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON.
OUTLOOK...
SAT-SUN...VFR.
MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS
ALONG WITH LOCALLY REDUCED CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 PM EDT THU APR 9 2015
.SYNOPSIS...
STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE
CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS
OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH
THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT
ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR
SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOST OF CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR
DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN
MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND
SOUTH. WIDESPREAD LOW CLOUDS WILL PERSIST INTO THE
OVERNIGHT...WITH THE EXCEPTION BEING THE FAR WESTERN STRIPE OF
ZONES WHERE SOME MIXING HAS ALLOWED FOR PARTIAL SUNSHINE TO
DEVELOP. THIS WILL BE REPLACED BY UPSTREAM CLOUDINESS BEFORE TOO
LONG AS SHOWERS CONTINUE TO MOVE OUT OF THE OHIO VALLEY.
LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN
STRONGLY DAMMED. HOWEVER...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING THROUGH EASTERN OHIO AND THE HRRR TIMES THEM INTO
MY WESTERN ZONES BETWEEN ABOUT 5 AND 8 PM. WHETHER WIDESPREAD
THUNDER MANAGES TO SURVIVE THE TREK INTO THE STABLE AIRMASS
REMAINS TO BE SEEN BUT I HAVE USED THE HRRR TO BRING A PERIOD OF
RAIN ACROSS MOST OF MY FCST AREA THIS EVENING THROUGH AROUND
MIDNIGHT...WITH STILL A GOOD CHANCE OF ADDITIONAL SHOWERS THROUGH
MORNING AHEAD OF THE APPROACHING FRONT.
OVERNIGHT LOWS FROM NEAR 40 EAST TO AROUND 50 IN THE WEST WILL BE
ANYWHERE FROM ABOUT 5 TO AS MUCH AS 20 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD
FRONT PRETTY MUCH BISECTING THE FCST AREA BY EARLY AFTERNOON. THE
GEFS DEVELOPS SLIGHTLY MORE INSTABILITY THAN DOES THE SREF...BUT
IF EITHER MODEL FAVORS AN AREA FOR SEVERE STORMS TOMORROW IT
WOULD BE OVER SERN PA DURING THE AFTERNOON AS THE FRONT PROGRESSES
EAST. AS IS OFTEN THE CASE IN PA...THE AMOUNT OF CLOUDCOVER WILL
HAVE MUCH TO SAY ABOUT THE SEVERE POTENTIAL. SPC DOES HAVE MY FAR
SERN ZONES OUTLOOKED FOR A SLIGHT RISK WHICH AT THIS RANGE LOOKS
REASONABLE.
TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S
ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA
FOR LATE FRIDAY INTO SAT.
MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY
NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS
WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION
USUALLY LEADS TO SOME SHOWERS.
OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND
COOL ON SAT. WARMER ON SUNDAY.
DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO
FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS
LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE.
FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR
CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT.
SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN
TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND
THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE
LATE AFTERNOON AND EVENING.
LLWS IS POSSIBLE THIS EVENING AS SFC WINDS REMAIN OUT OF THE
SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE
SOUTHWEST AT 30-50KT.
A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE
LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL
FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR
CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING.
ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ
VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON.
OUTLOOK...
SAT-SUN...VFR.
MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS
ALONG WITH LOCALLY REDUCED CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1233 PM CDT THU APR 9 2015
.AVIATION...
CONCERNS..TIMING OF FROPA AND CONVECTION.
AT MIDDAY...A COLD FRONT EXTENDED FROM SOUTHEAST KANSAS TO EAST OF
WICHITA FALLS TO SOUTH OF LUBBOCK. THE FRONT IS EXPECTED TO ARRIVE
AT KAFW NEAR 23Z...KDFW 2330Z...KDAL AROUND 00Z AND KACT BY 03Z.
SOME CONVECTION...MOSTLY SHRA...COULD AFFECT THE TERMINALS EARLY
AFTERNOON...THEN EXPECT SOME TSRA MIXED IN. STRONG TO SEVERE TSRA
ARE EXPECTED TO FORM ALONG THE FRONT MID/LATE AFTERNOON FROM
NORTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA AND BUILD DOWN INTO
NORTHEAST/NORTH TEXAS. WILL CARRY VCTS 20-02Z WITH THE BEST TIME
PERIOD FOR AFFECTING THE METROPLEX TERMINALS BEING 22-00Z...AND
KACT 02-05Z.
SOUTHERLY WINDS 10 TO 16 KNOTS WILL VEER WESTERLY AS A
PRE-FRONTAL SURFACE TROUGH ARRIVES AROUND 20Z...THEN GO NORTH
14-20 KNOTS AND GUSTY THIS EVENING AFTER FROPA. WINDS WILL BECOME
NORTHEASTERLY NEAR 10 KNOTS MID MORNING TOMORROW.
CIGS...KACT WILL REMAIN MVFR THROUGH MID AFTERNOON THEN LIFTING TO
AROUND 4000 FEET THIS EVENING AND BKN040-050 OVERNIGHT THROUGH
TOMORROW MORNING. SCATTERED MVFR CIGS ACROSS THE METROPLEX SHOULD
LIFT WEST TO EAST DURING THE AFTERNOON WITH SCT-BKN035-040 UNTIL
02Z THEN BECOMING VFR AFTERWARD. 75
&&
.UPDATE...
A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS
MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRANBURY AND LAMPASAS.
THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF
THE I-20 CORRIDOR THIS MORNING. 58
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/
A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A
GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL
CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE.
AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST
DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS
FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE
OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME
OF THIS ACTIVITY THROUGH DAYBREAK.
THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS
AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE
HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR
OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z.
WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE
LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL
AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID
TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO
2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR
VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE
WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND
DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW
TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM
HELICITY VALUES APPROACHING 200 M2/S2.
EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND
SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL
BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE
PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE
FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN
WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH
30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE.
THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING
IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY
NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT
THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL
MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40
WACO, TX 84 58 73 58 76 / 40 60 20 30 40
PARIS, TX 79 51 73 52 73 / 40 70 10 30 40
DENTON, TX 83 53 73 54 73 / 30 30 10 30 40
MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40
DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40
TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40
CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40
TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40
MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM CDT THU APR 9 2015
TWO AREAS OF CONCERN TONIGHT FOR PRECIPITATION. THE FIRST WILL BE
EARLY THIS EVENING ACROSS THE FAR SOUTH AS THE SURFACE LOW PASSES
BY THE REGION. THE LATEST INDICATIONS CONTINUE TO POINT TO THE
SURFACE LOW TRACKING JUST SOUTH OF THE AREA AS IT COMES OUT OF
EASTERN IOWA INTO SOUTH CENTRAL WISCONSIN. ON THIS PATH...THE WARM
SECTOR AND THE BEST SUPPORT FOR SEVERE WEATHER WILL REMAIN OUTSIDE
OF THE FORECAST AREA. LOOKING AT THE TRENDS IN THE 09.19Z RAP AND
HRRR...THE CONVECTION THAT DEVELOPS AHEAD OF THE SURFACE LOW LATE
THIS AFTERNOON COULD POSSIBLY CLIP GRANT COUNTY BUT SHOULD BE TO
THE EAST OF THE AREA BY 00Z. BASED ON THIS SCENARIO...WILL ONLY
SHOW ABOUT A 50 PERCENT CHANCE FOR SHOWERS AND STORMS ACROSS THE
FAR SOUTHERN SECTIONS FOR EARLY THIS EVENING.
THE OTHER AREA OF CONCERN WILL BE IN THE DEFORMATION AREA ON THE
BACK SIDE OF THE SURFACE LOW. THIS AREA LOOKS TO HAVE SOME PRETTY
GOOD FORCING IN IT THIS EVENING AS THE SHORT WAVE TROUGH...CURRENTLY
OVER THE MISSOURI RIVER VALLEY...CONTINUES TO MOVE NORTHEAST AND
TAKES ON A NEGATIVE TILT. THIS WILL ALLOW FOR A QUICK SHOT OF
STRONG PV ADVECTION TO OCCUR IN THE 500-300 MB LAYER. THERE IS A
GOOD LOW LEVEL BAROCLINIC ZONE IN PLACE WITH TEMPERATURES IN THE
30S AND 40S ON THE COOL SIDE OF THE LOW AND IN THE 60S AND 70S IN
THE WARM SECTOR. BOTH THE 09.12Z NAM AND GFS SHOW MODERATE TO
STRONG FRONTOGENESIS OCCURRING IN THE DEFORMATION ZONE WITH THIS
BEING THE STRONGEST IN THE 750-650 MB LAYER. THIS FRONTOGENESIS
LOOKS TO SIT UNDERNEATH AN AREA OF STRONG UPPER LEVEL DIVERGENCE
FROM A COUPLED UPPER LEVEL JET STRUCTURE. THE NAM SUGGESTS THIS
SYSTEM SHOULD GET STRONG ENOUGH TO WRAP THE WARM CONVEYOR BELT
AROUND THE LOW TO PRODUCE 4-6 UBAR/S OF ISENTROPIC UP GLIDE ON THE
295K SURFACE THIS EVENING IN THE SAME GENERAL AREA AS THE
FRONTOGENESIS. LOOKS LIKE THE DEFORMATION PRECIPITATION IS ALREADY
STARTING TO FORM ACROSS SOUTHEAST MINNESOTA AND EXPECT THIS WILL
CONTINUE TO GROW AS THE FORCING INCREASES THIS EVENING. WHEN THE
STRONGEST FORCING OCCURS...THIS SHOULD BE ENOUGH TO PRODUCE SOME
HIGH PRECIPITATION RATES TO ALLOW FOR A CHANGE OVER TO ALL SNOW
DESPITE SOME WARM LOW LEVEL BOUNDARY TEMPERATURES. THE BEST
CHANCES FOR THIS TO OCCUR THIS EVENING WILL BE FROM SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN. THE DURATION OF THIS
SHOULD NOT BE VERY LONG OVER SOUTHEAST MINNESOTA...BUT THE SNOW
COULD PERSIST INTO THE OVERNIGHT HOURS FOR NORTH CENTRAL
MINNESOTA. THIS COULD LEAD TO ACCUMULATIONS OF 2 TO 3 INCHES
ACROSS TAYLOR COUNTY AND WILL ISSUE A WINTER WEATHER ADVISORY TO
HANDLE THIS.
A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE AREA THURSDAY.
IT LOOKS LIKE A LOT OF THE DEEP MOISTURE WILL GET SCOURED OUT
BEHIND THE MAIN SHORT WAVE TROUGH BUT STILL EXPECT THAT THIS WAVE
WILL BE STRONG ENOUGH TO PRODUCE SOME LIGHT PRECIPITATION FOR
AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATE MORNING
THROUGH THE AFTERNOON. HIGH PRESSURE THEN LOOKS TO BUILD IN BEHIND
THIS SYSTEM AND DRIFT ACROSS THE REGION TO KEEP THE FRIDAY NIGHT
THROUGH SATURDAY NIGHT PERIOD DRY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 350 PM CDT THU APR 9 2015
THE MODELS ARE ALL IN GOOD AGREEMENT OF ANOTHER SHORT WAVE TROUGH
COMING ACROSS THE UPPER MIDWEST FOR SUNDAY AND SUNDAY NIGHT. THIS
IS EXPECTED TO PUSH A COLD FRONT ACROSS THE REGION WHICH SHOULD BE
ACCOMPANIED BY A LINE OF SHOWERS AND STORMS. SOME DIFFERENCES
BETWEEN THE 09.12Z GFS AND ECMWF ON HOW FAST THIS ACTIVITY MOVES
IN SUNDAY WITH THE GFS QUICKER TO BRING IT IN THAN THE ECMWF. WILL
ATTEMPT TO RESOLVE THESE DIFFERENCES WITH LATER FORECASTS ONCE THE
SHORT TERM WEATHER QUIETS DOWN. THE MODELS ALSO ARE IN GOOD
AGREEMENT FOR LATER IN THE PERIOD BRINGING ANOTHER SYSTEM INTO THE
CENTRAL PART OF THE COUNTRY FOR LATE IN THE PERIOD. WITH THE
SOUTHWEST FLOW AHEAD OF THIS SYSTEM...COULD SEE SOME ACTIVITY FORM
AS EARLY AS TUESDAY NIGHT AND THEN CONTINUE OFF AND ON THROUGH
THURSDAY. HAVE LET THE MODEL CONSENSUS GRIDS RIDE WITH THIS SYSTEM
WITH GENERAL 30 TO 40 PERCENT CHANCES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 600 PM CDT THU APR 9 2015
CIGS:
1 KFT OR LOWER CIGS SHOULD HOLD ACROSS THE AREA INTO THE EARLY
OVERNIGHT HOURS...BUT SATELLITE TRENDS/RH FIELDS/BUFKIT SOUNDINGS
SUGGEST THE BACKEDGE OF THE LOW CLOUD DECK WILL SWEEP THROUGH IN THE
08-10Z WINDOW. A BRIEF PERIOD OF VFR COULD OCCUR BEFORE AN UPPER
LEVEL SHORTWAVE TROUGH TRACKS ACROSS THE AREA LATE FRI MORNING-
AFTERNOON. MVFR CIGS LOOK LIKELY.
WINDS:
WINDS ARE GOING TO INCREASE AND COULD BE GUSTY THIS EVENING AS A LOW
PRESSURE SYSTEM TRACKS JUST TO THE SOUTH OF KRST/KLSE. SHOULD SEE
SOME DECREASE IN SPEEDS TOWARD 12Z FRI...BUT WINDS WILL STAY +10 KTS
THROUGH THE DAY FRI.
WX/VSBY:
DEFORMATION REGION OF A STORM SYSTEM WILL KEEP THE AREA
UNDER SHOWERS THIS EVENING INTO THE OVERNIGHT. PERHAPS AN ISOLATED
STORM...BUT MOST OF THE INSTABILITY STAYS SOUTH...AND CHANCES LOOK
SMALL ENOUGH TO NOT INCLUDE IN THE FORECAST FOR NOW. EXPECTING SOME
VSBY RESTRICTIONS FROM TIME TO TIME...BUT LATEST OBS ARE RATHER
VARIABLE WITHIN AND OUTSIDE OF THE RAIN SHIELD...LOWERING CONFIDENCE
A BIT.
ANOTHER ROUND OF SCATTERED -SHRA IS LIKELY FROM LATE MORNING INTO
THE AFTERNOON FRIDAY AS A SHORTWAVE PASSES ACROSS THE AREA. COULD
HAVE SOME DIP INTO MVFR VSBYS WITH THE SHOWERS...BUT MOSTLY P6SM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 AM CDT
FRIDAY FOR WIZ017.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
550 PM CDT THU APR 9 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 536 PM CDT THU APR 9 2015
FCST ISSUES SPAN THE SEASONS THIS EVENING AS STRENGTHENING
CYCLONE LIFTS NEWD FM IA. CLUSTER OF SVR STORMS IN S-C WI HEADING
NE. LOCAL MESO PLOTS SHOW POOL OF INSTABILITY EXPANDING NE...BUT
NOT AS QUICKLY AS THE STORMS ARE MOVG NE. IT/S GOING TO BE A CLOSE
CALL ON WHETHER A SVR STORM COULD CLIP THE SRN PART OF THE FCST
AREA BEFORE WEAKENING. THE PRIMARY SVR THREAT WOULD BE HAIL...AND
THINK THAT WOULD NEED TO HAPPEN WITHIN THE NEXT COUPLE HRS...BEFORE
PCPN GETS TOO WIDESPREAD.
IT/S A COMPLETELY DIFFERENT SITN ACRS THE NW CORNER OF THE FCST
AREA...WHERE THE THREAT IS HEAVY SNOW. WATCHING THE UPR
DEFORMATION ZONE EXPAND NEWD AS MAIN SHRTWV EJECTS TOWARD WI.
EXTRAOLATION OF SRN EDGE OF THE DEFORMATION ZONE WOULD BRING IT
ACRS THE NW PART OF THE FCST AREA. MAIN QUESTIONS FOR SNOW AMNTS
CONTINUE TO BE TIMING OF THE CHANGEOVER AND HOW MUCH PCPN FALLS
AFTER THAT TIME. NRN STREAM SHRTWV EDGING IN FM THE NW MAY TEND TO
DISRUPT THE COMMA HEAD AND NUDGE IT EWD...LIMITING THE AMNT OF
PCPN THAT FALLS AFTER THE CHANGEOVER. ON THE OTHER HAND...PCPN
COULD BE FALLING QUITE HEAVILY AFTER THE CHANGEOVER...SO THE
POTENTIAL IS THERE FOR A PERIOD OF HEAVY SNOW. NEED TO WATCH THIS
VERY CLOSELY...BUT LIKELY WON/T BE ABLE TO MAKE ANY HEADLINE
CHANGES UNTIL WE START TO SEE THE CHANGEOVER OCCURRING.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 241 PM CDT THU APR 9 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE HEADING NORTHEAST AS IT ENTERS SOUTH-CENTRAL IOWA EARLY
THIS AFTERNOON. COMMA HEAD PRECIPITATION IS OCCURRING JUST TO THE
REAR OF THE PRIMARY SHORTWAVE LOCATED OVER CENTRAL NEBRASKA...WHERE
HEAVY SNOW AND A FEW LIGHTNING STRIKES HAVE BEEN DETECTED.
DOWNSTREAM OF THE SYSTEM...A SHORTWAVE IMPULSE IS GENERATING SHOWERS
AND THUNDERSTORMS OVER THE EASTERN HALF OF WISCONSIN. MOST OF THE
THUNDERSTORM ACTIVITY HAS DIMINISHED AS THEY REACHED THE WAUTOMA TO
MANITOWOC CORRIDOR SINCE ELEVATED INSTABILITY HAS NOT BEEN ABLE TO
EXTEND THAT FAR NORTH. AS A RESULT...LOOK FOR PERIODS OF SHOWERS
AND DRIZZLE TO CONTINUE TO IMPACT THE REGION FOR THE REST OF THE
AFTERNOON. THE MAIN FORECAST CONCERNS REVOLVE AROUND HEAVY WINTRY
PRECIP ACROSS THE NORTH AND THUNDERSTORM CHANCES OVER THE SOUTH AS A
CYCLONE PASSES ACROSS THE REGION TONIGHT.
TONIGHT...THE STRONG SHORTWAVE OVER NEBRASKA WILL SWING NORTHEAST AS
IT PUSHES A SURFACE LOW FROM THE NORTHWEST CORNER OF ILLINOIS TO
CENTRAL LAKE MICHIGAN TO THE STRAITS OF MACKINAC. AHEAD OF THE
LOW...ELEVATED INSTABILITY UP TO 500 J/KG MAY SNEAK INTO
EAST-CENTRAL WISCONSIN WITHIN A REGION OF STRONG UPWARD MOTION WHICH
COULD GENERATE SCATTERED THUNDERSTORMS THOUGH AROUND MID-EVENING.
IF THUNDERSTORMS DO OCCUR...SMALL HAIL WILL BE POSSIBLE.
TO THE NORTH OF THE LOW...EXCELLENT UPPER DIVERGENCE COMBINED WITH
STRONG MID-LEVEL FGEN AND REDUCED STABILITY WILL LEAD TO A HEALTHY
DEFORMATION BAND DEVELOPING FROM WEST-CENTRAL TO NORTH-CENTRAL
WISCONSIN. THIS DEFORMATION BAND WILL BRING A PROLONGED PERIOD OF
MODERATE TO HEAVY PRECIP AT TIMES. WITH TEMPS AND DEWPOINTS IN THE
MIDDLE 30S AT THE START OF THE EVENING...PRECIP WILL LIKELY BE ALL
RAIN FOR THE FIRST COUPLE HOURS. THEN COLDER AIR WILL GRADUALLY GET
DRAWN INTO NORTH-CENTRAL WISCONSIN TO CHANGE PRECIP TO SLEET AND
THEN SNOW. BUFKIT SOUNDINGS INDICATE THAT THE NORTH COULD SEE A FEW
HOUR PERIOD OF SLEET WHICH COULD LEAD TO DECENT SLEET ACCUMULATIONS
GIVEN THE EXPECTED PRECIP RATES. THEN ONCE TEMPS COOL ENOUGH FOR
ALL SNOW...SNOWFALL RATES COULD EASILY EXCEED AN INCH PER HOUR AT
TIMES. BUT ONE OF THE MOST DIFFICULT ASPECTS OF THIS FORECAST IS IN
REGARDS TO HOW QUICKLY THIS CHANGE OVER OCCURS SINCE COLD AIR IS NOT
THAT PLENTIFUL TO OUR NORTH. BEST GUESS FROM GUIDANCE INDICATES
THIS CHANGE OVER WILL OCCUR LATE THIS EVENING OVER N-C WISCONSIN AND
EARLY OVERNIGHT OVER TO CENTRAL WISCONSIN TO THE IRON MOUNTAIN
AREA. THE INITIAL RAIN AND SLEET WILL EAT UP SOME OF THE QPF
AMOUNTS THIS EVENING...BUT GUIDANCE STILL POINT TOWARDS OVER A HALF
INCH FALLING AFTER 06Z. ADDITIONALLY...THE HI-RES MODELS ARE ALSO
INDICATING BANDING TAKING PLACE...AND A LITTLE FARTHER TO THE EAST
THAN SHOWN PREVIOUSLY. HAVE SHIFTED QPF AND SNOW AMOUNTS TO THE
EAST AS A RESULT...WHICH GIVES SNOW AMOUNTS OF 3-6 INCHES FROM
LINCOLN AND LANGLADE ON NORTH. A QUARTER TO A HALF INCH OF THAT
COULD TURN OUT TO BE SLEET ACCUMULATION. LOCALLY HIGHER AMOUNTS
WILL BE POSSIBLE DEPENDING ON WHERE THE SNOW BANDS SET UP. BECAUSE
OF THIS UNCERTAINTY...WILL ISSUE A WINTER WEATHER ADVISORY FROM
02Z-13Z.
FRIDAY...PRECIP WITH SNOW WEST OF THE FOX VALLEY AND RAIN TO THE
EAST WILL DIMINISH EARLY FRIDAY MORNING. SHOULD SEE A CLOUDY AND
WINDY START TO THE DAY OTHERWISE. A TRAILING SHORTWAVE WILL PUSH
ACROSS SOUTHERN WISCONSIN DURING THE AFTERNOON WHICH COULD CREATE AN
ISOLATED SHOWER OVER THE NORTHERN HALF OF THE STATE. LEFT A SMALL
CHANCE TO ACCOUNT FOR THIS. HIGHS RANGING FROM THE LOW 40S NORTH TO
LOW 50S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 241 PM CDT THU APR 9 2015
PCPN TRENDS SUNDAY/SUNDAY NIGHT AND DURING THE MIDDLE OF NEXT WEEK
ARE THE MAIN FCST CONCERNS.
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION FRIDAY NIGHT. USED
A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR MIN TEMPS...BUT WITH
THE POTENTIAL FOR A LINGERING SNOW COVER OVER NC WI...HAVE BUMPED MIN
TEMPS DOWN THERE.
HIGH PRESSURE WILL BRING DRY CONDITIONS SATURDAY AND SATURDAY NIGHT...
WITH DEVELOPING SOUTH FLOW RESULTING IN MODERATING TEMPERATURES.
A COLD FRONT WILL MOVE INTO WESTERN WI ON SUNDAY AFTERNOON...THEN
ACROSS THE FORECAST AREA SUNDAY EVENING. HAVE SLOWED DOWN THE
ARRIVAL TIME OF SHOWERS ON SUNDAY AFTERNOON (MAINLY NC/C WI LATE
IN THE DAY)...BUT WILL SPREAD HIGH CHC/LOW LIKELY POPS OVER THE
ENTIRE CWA SUNDAY NIGHT. H8 LI`S SLIGHTLY BLO ZERO AND STEEP MID-
LEVEL LAPSE RATES SUGGEST POTENTIAL FOR AT LEAST ISOLD TSTMS...SO
HAVE INCLUDED A SLGT CHC OF TSTMS.
HIGH PRESSURE AND AND ASSOCIATED DRY AND MILD CONDITIONS WILL
RETURN TO WISCONSIN ON MONDAY AND TUESDAY.
THE FCST BECOMES A BIT MUDDLED DURING THE MIDDLE OF THE WEEK...AS
SW FLOW ALOFT DEVELOPS AND LOW PRESSURE AND AN ASSOCIATED COLD
FRONT EDGE TOWARD THE WESTERN GREAT LAKES. MOST MODELS NOW KEEP
TUESDAY NIGHT DRY...WITH THE ECMWF BRINGING PCPN INTO THE REGION
ON WEDS...AND THE GFS HOLDING OFF UNTIL ABOUT THURSDAY. GIVEN THE
UNCERTAINTY...WILL CARRY CHC POPS THROUGH THIS PERIOD. THE GOOD
NEWS IS THAT ANY PCPN THAT OCCURS SHOULD FALL AS ALL RAIN...WHICH
IS DEFINITELY A STEP IN THE RIGHT DIRECTION.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 536 PM CDT THU APR 9 2015
WL CARRY THUNDER OVER THE SRN 1/2 OF THE FCST AREA FOR A FEW HRS
THIS EVENING. VERY POOR FLIGHT CONDITIONS DURING THE FIRST PORTION
OF THE TAF PERIOD WL GRADUALLY IMPROVE FRIDAY AS THE CYCLONE PULLS
AWAY FM THE REGION.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CDT
FRIDAY FOR WIZ011-012-019.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM CDT
FRIDAY FOR WIZ005-010-018.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
350 PM CDT THU APR 9 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM CDT THU APR 9 2015
TWO AREAS OF CONCERN TONIGHT FOR PRECIPITATION. THE FIRST WILL BE
EARLY THIS EVENING ACROSS THE FAR SOUTH AS THE SURFACE LOW PASSES
BY THE REGION. THE LATEST INDICATIONS CONTINUE TO POINT TO THE
SURFACE LOW TRACKING JUST SOUTH OF THE AREA AS IT COMES OUT OF
EASTERN IOWA INTO SOUTH CENTRAL WISCONSIN. ON THIS PATH...THE WARM
SECTOR AND THE BEST SUPPORT FOR SEVERE WEATHER WILL REMAIN OUTSIDE
OF THE FORECAST AREA. LOOKING AT THE TRENDS IN THE 09.19Z RAP AND
HRRR...THE CONVECTION THAT DEVELOPS AHEAD OF THE SURFACE LOW LATE
THIS AFTERNOON COULD POSSIBLY CLIP GRANT COUNTY BUT SHOULD BE TO
THE EAST OF THE AREA BY 00Z. BASED ON THIS SCENARIO...WILL ONLY
SHOW ABOUT A 50 PERCENT CHANCE FOR SHOWERS AND STORMS ACROSS THE
FAR SOUTHERN SECTIONS FOR EARLY THIS EVENING.
THE OTHER AREA OF CONCERN WILL BE IN THE DEFORMATION AREA ON THE
BACK SIDE OF THE SURFACE LOW. THIS AREA LOOKS TO HAVE SOME PRETTY
GOOD FORCING IN IT THIS EVENING AS THE SHORT WAVE TROUGH...CURRENTLY
OVER THE MISSOURI RIVER VALLEY...CONTINUES TO MOVE NORTHEAST AND
TAKES ON A NEGATIVE TILT. THIS WILL ALLOW FOR A QUICK SHOT OF
STRONG PV ADVECTION TO OCCUR IN THE 500-300 MB LAYER. THERE IS A
GOOD LOW LEVEL BAROCLINIC ZONE IN PLACE WITH TEMPERATURES IN THE
30S AND 40S ON THE COOL SIDE OF THE LOW AND IN THE 60S AND 70S IN
THE WARM SECTOR. BOTH THE 09.12Z NAM AND GFS SHOW MODERATE TO
STRONG FRONTOGENESIS OCCURRING IN THE DEFORMATION ZONE WITH THIS
BEING THE STRONGEST IN THE 750-650 MB LAYER. THIS FRONTOGENESIS
LOOKS TO SIT UNDERNEATH AN AREA OF STRONG UPPER LEVEL DIVERGENCE
FROM A COUPLED UPPER LEVEL JET STRUCTURE. THE NAM SUGGESTS THIS
SYSTEM SHOULD GET STRONG ENOUGH TO WRAP THE WARM CONVEYOR BELT
AROUND THE LOW TO PRODUCE 4-6 UBAR/S OF ISENTROPIC UP GLIDE ON THE
295K SURFACE THIS EVENING IN THE SAME GENERAL AREA AS THE
FRONTOGENESIS. LOOKS LIKE THE DEFORMATION PRECIPITATION IS ALREADY
STARTING TO FORM ACROSS SOUTHEAST MINNESOTA AND EXPECT THIS WILL
CONTINUE TO GROW AS THE FORCING INCREASES THIS EVENING. WHEN THE
STRONGEST FORCING OCCURS...THIS SHOULD BE ENOUGH TO PRODUCE SOME
HIGH PRECIPITATION RATES TO ALLOW FOR A CHANGE OVER TO ALL SNOW
DESPITE SOME WARM LOW LEVEL BOUNDARY TEMPERATURES. THE BEST
CHANCES FOR THIS TO OCCUR THIS EVENING WILL BE FROM SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN. THE DURATION OF THIS
SHOULD NOT BE VERY LONG OVER SOUTHEAST MINNESOTA...BUT THE SNOW
COULD PERSIST INTO THE OVERNIGHT HOURS FOR NORTH CENTRAL
MINNESOTA. THIS COULD LEAD TO ACCUMULATIONS OF 2 TO 3 INCHES
ACROSS TAYLOR COUNTY AND WILL ISSUE A WINTER WEATHER ADVISORY TO
HANDLE THIS.
A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE AREA THURSDAY.
IT LOOKS LIKE A LOT OF THE DEEP MOISTURE WILL GET SCOURED OUT
BEHIND THE MAIN SHORT WAVE TROUGH BUT STILL EXPECT THAT THIS WAVE
WILL BE STRONG ENOUGH TO PRODUCE SOME LIGHT PRECIPITATION FOR
AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATE MORNING
THROUGH THE AFTERNOON. HIGH PRESSURE THEN LOOKS TO BUILD IN BEHIND
THIS SYSTEM AND DRIFT ACROSS THE REGION TO KEEP THE FRIDAY NIGHT
THROUGH SATURDAY NIGHT PERIOD DRY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 350 PM CDT THU APR 9 2015
THE MODELS ARE ALL IN GOOD AGREEMENT OF ANOTHER SHORT WAVE TROUGH
COMING ACROSS THE UPPER MIDWEST FOR SUNDAY AND SUNDAY NIGHT. THIS
IS EXPECTED TO PUSH A COLD FRONT ACROSS THE REGION WHICH SHOULD BE
ACCOMPANIED BY A LINE OF SHOWERS AND STORMS. SOME DIFFERENCES
BETWEEN THE 09.12Z GFS AND ECMWF ON HOW FAST THIS ACTIVITY MOVES
IN SUNDAY WITH THE GFS QUICKER TO BRING IT IN THAN THE ECMWF. WILL
ATTEMPT TO RESOLVE THESE DIFFERENCES WITH LATER FORECASTS ONCE THE
SHORT TERM WEATHER QUIETS DOWN. THE MODELS ALSO ARE IN GOOD
AGREEMENT FOR LATER IN THE PERIOD BRINGING ANOTHER SYSTEM INTO THE
CENTRAL PART OF THE COUNTRY FOR LATE IN THE PERIOD. WITH THE
SOUTHWEST FLOW AHEAD OF THIS SYSTEM...COULD SEE SOME ACTIVITY FORM
AS EARLY AS TUESDAY NIGHT AND THEN CONTINUE OFF AND ON THROUGH
THURSDAY. HAVE LET THE MODEL CONSENSUS GRIDS RIDE WITH THIS SYSTEM
WITH GENERAL 30 TO 40 PERCENT CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM CDT THU APR 9 2015
PERIODS OF IFR AND LIFR CONDITIONS ALONG WITH SHOWERS AND
THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS A STRONG LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. LOOK FOR WINDS TO INCREASE OUT
OF THE NORTHEAST AS THE LOW APPROACHES LATE THIS AFTERNOON THEN
TURN NORTHWEST AS THE LOW MOVES TO THE NORTHEAST OF THE REGION.
LOOK FOR NORTHWEST WINDS TO INCREASE TO 18 TO 23 KTS TONIGHT WITH
GUSTS OF AROUND 35 KTS POSSIBLE. MVFR CONDITIONS WILL RETURN LATE
TONIGHT INTO EARLY FRIDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 AM CDT
FRIDAY FOR WIZ017.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 241 PM CDT THU APR 9 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE HEADING NORTHEAST AS IT ENTERS SOUTH-CENTRAL IOWA EARLY
THIS AFTERNOON. COMMA HEAD PRECIPITATION IS OCCURRING JUST TO THE
REAR OF THE PRIMARY SHORTWAVE LOCATED OVER CENTRAL NEBRASKA...WHERE
HEAVY SNOW AND A FEW LIGHTNING STRIKES HAVE BEEN DETECTED.
DOWNSTREAM OF THE SYSTEM...A SHORTWAVE IMPULSE IS GENERATING SHOWERS
AND THUNDERSTORMS OVER THE EASTERN HALF OF WISCONSIN. MOST OF THE
THUNDERSTORM ACTIVITY HAS DIMINISHED AS THEY REACHED THE WAUTOMA TO
MANITOWOC CORRIDOR SINCE ELEVATED INSTABILITY HAS NOT BEEN ABLE TO
EXTEND THAT FAR NORTH. AS A RESULT...LOOK FOR PERIODS OF SHOWERS
AND DRIZZLE TO CONTINUE TO IMPACT THE REGION FOR THE REST OF THE
AFTERNOON. THE MAIN FORECAST CONCERNS REVOLVE AROUND HEAVY WINTRY
PRECIP ACROSS THE NORTH AND THUNDERSTORM CHANCES OVER THE SOUTH AS A
CYCLONE PASSES ACROSS THE REGION TONIGHT.
TONIGHT...THE STRONG SHORTWAVE OVER NEBRASKA WILL SWING NORTHEAST AS
IT PUSHES A SURFACE LOW FROM THE NORTHWEST CORNER OF ILLINOIS TO
CENTRAL LAKE MICHIGAN TO THE STRAITS OF MACKINAC. AHEAD OF THE
LOW...ELEVATED INSTABILITY UP TO 500 J/KG MAY SNEAK INTO
EAST-CENTRAL WISCONSIN WITHIN A REGION OF STRONG UPWARD MOTION WHICH
COULD GENERATE SCATTERED THUNDERSTORMS THOUGH AROUND MID-EVENING.
IF THUNDERSTORMS DO OCCUR...SMALL HAIL WILL BE POSSIBLE.
TO THE NORTH OF THE LOW...EXCELLENT UPPER DIVERGENCE COMBINED WITH
STRONG MID-LEVEL FGEN AND REDUCED STABILITY WILL LEAD TO A HEALTHY
DEFORMATION BAND DEVELOPING FROM WEST-CENTRAL TO NORTH-CENTRAL
WISCONSIN. THIS DEFORMATION BAND WILL BRING A PROLONGED PERIOD OF
MODERATE TO HEAVY PRECIP AT TIMES. WITH TEMPS AND DEWPOINTS IN THE
MIDDLE 30S AT THE START OF THE EVENING...PRECIP WILL LIKELY BE ALL
RAIN FOR THE FIRST COUPLE HOURS. THEN COLDER AIR WILL GRADUALLY GET
DRAWN INTO NORTH-CENTRAL WISCONSIN TO CHANGE PRECIP TO SLEET AND
THEN SNOW. BUFKIT SOUNDINGS INDICATE THAT THE NORTH COULD SEE A FEW
HOUR PERIOD OF SLEET WHICH COULD LEAD TO DECENT SLEET ACCUMULATIONS
GIVEN THE EXPECTED PRECIP RATES. THEN ONCE TEMPS COOL ENOUGH FOR
ALL SNOW...SNOWFALL RATES COULD EASILY EXCEED AN INCH PER HOUR AT
TIMES. BUT ONE OF THE MOST DIFFICULT ASPECTS OF THIS FORECAST IS IN
REGARDS TO HOW QUICKLY THIS CHANGE OVER OCCURS SINCE COLD AIR IS NOT
THAT PLENTIFUL TO OUR NORTH. BEST GUESS FROM GUIDANCE INDICATES
THIS CHANGE OVER WILL OCCUR LATE THIS EVENING OVER N-C WISCONSIN AND
EARLY OVERNIGHT OVER TO CENTRAL WISCONSIN TO THE IRON MOUNTAIN
AREA. THE INITIAL RAIN AND SLEET WILL EAT UP SOME OF THE QPF
AMOUNTS THIS EVENING...BUT GUIDANCE STILL POINT TOWARDS OVER A HALF
INCH FALLING AFTER 06Z. ADDITIONALLY...THE HI-RES MODELS ARE ALSO
INDICATING BANDING TAKING PLACE...AND A LITTLE FARTHER TO THE EAST
THAN SHOWN PREVIOUSLY. HAVE SHIFTED QPF AND SNOW AMOUNTS TO THE
EAST AS A RESULT...WHICH GIVES SNOW AMOUNTS OF 3-6 INCHES FROM
LINCOLN AND LANGLADE ON NORTH. A QUARTER TO A HALF INCH OF THAT
COULD TURN OUT TO BE SLEET ACCUMULATION. LOCALLY HIGHER AMOUNTS
WILL BE POSSIBLE DEPENDING ON WHERE THE SNOW BANDS SET UP. BECAUSE
OF THIS UNCERTAINTY...WILL ISSUE A WINTER WEATHER ADVISORY FROM
02Z-13Z.
FRIDAY...PRECIP WITH SNOW WEST OF THE FOX VALLEY AND RAIN TO THE
EAST WILL DIMINISH EARLY FRIDAY MORNING. SHOULD SEE A CLOUDY AND
WINDY START TO THE DAY OTHERWISE. A TRAILING SHORTWAVE WILL PUSH
ACROSS SOUTHERN WISCONSIN DURING THE AFTERNOON WHICH COULD CREATE AN
ISOLATED SHOWER OVER THE NORTHERN HALF OF THE STATE. LEFT A SMALL
CHANCE TO ACCOUNT FOR THIS. HIGHS RANGING FROM THE LOW 40S NORTH TO
LOW 50S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 241 PM CDT THU APR 9 2015
PCPN TRENDS SUNDAY/SUNDAY NIGHT AND DURING THE MIDDLE OF NEXT WEEK
ARE THE MAIN FCST CONCERNS.
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION FRIDAY NIGHT. USED
A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR MIN TEMPS...BUT WITH
THE POTENTIAL FOR A LINGERING SNOW COVER OVER NC WI...HAVE BUMPED MIN
TEMPS DOWN THERE.
HIGH PRESSURE WILL BRING DRY CONDITIONS SATURDAY AND SATURDAY NIGHT...
WITH DEVELOPING SOUTH FLOW RESULTING IN MODERATING TEMPERATURES.
A COLD FRONT WILL MOVE INTO WESTERN WI ON SUNDAY AFTERNOON...THEN
ACROSS THE FORECAST AREA SUNDAY EVENING. HAVE SLOWED DOWN THE
ARRIVAL TIME OF SHOWERS ON SUNDAY AFTERNOON (MAINLY NC/C WI LATE
IN THE DAY)...BUT WILL SPREAD HIGH CHC/LOW LIKELY POPS OVER THE
ENTIRE CWA SUNDAY NIGHT. H8 LI`S SLIGHTLY BLO ZERO AND STEEP MID-
LEVEL LAPSE RATES SUGGEST POTENTIAL FOR AT LEAST ISOLD TSTMS...SO
HAVE INCLUDED A SLGT CHC OF TSTMS.
HIGH PRESSURE AND AND ASSOCIATED DRY AND MILD CONDITIONS WILL
RETURN TO WISCONSIN ON MONDAY AND TUESDAY.
THE FCST BECOMES A BIT MUDDLED DURING THE MIDDLE OF THE WEEK...AS
SW FLOW ALOFT DEVELOPS AND LOW PRESSURE AND AN ASSOCIATED COLD
FRONT EDGE TOWARD THE WESTERN GREAT LAKES. MOST MODELS NOW KEEP
TUESDAY NIGHT DRY...WITH THE ECMWF BRINGING PCPN INTO THE REGION
ON WEDS...AND THE GFS HOLDING OFF UNTIL ABOUT THURSDAY. GIVEN THE
UNCERTAINTY...WILL CARRY CHC POPS THROUGH THIS PERIOD. THE GOOD
NEWS IS THAT ANY PCPN THAT OCCURS SHOULD FALL AS ALL RAIN...WHICH
IS DEFINITELY A STEP IN THE RIGHT DIRECTION.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1222 PM CDT THU APR 9 2015
IFR TO LIFR CIGS AND VSBYS TO PERSIST THROUGH THE
EVENING AS A STRENGTHENING AREA OF LOW PRESSURE TRACKS NORTHEAST
FROM THE CENTRAL PLAINS TO CENTRAL LAKE MICHIGAN. AHEAD OF THE
LOW...AREAS OF SHOWERS AND FOG WILL PREVAIL THROUGH EARLY THIS
EVENING...WITH A FEW THUNDERSTORMS MIXED IN OVER CENTRAL TO
NORTHEAST WISCONSIN. THEN AS THE LOW PASSES...RAIN WILL CHANGE TO
SNOW OVER CENTRAL AND NORTH-CENTRAL WISCONSIN WHERE SEVERAL INCHES
ARE POSSIBLE...HIGHEST OVER NORTH-CENTRAL WISCONSIN INCLUDING RHI.
THE SNOW WILL TAPER OFF LATE TONIGHT AT THE SAME TIME AS NORTHWEST
WINDS BECOME STRONG AND GUSTY. CIGS WILL SLOWLY IMPROVE FRIDAY
MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CDT
FRIDAY FOR WIZ011-012-019.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM CDT
FRIDAY FOR WIZ005-010-018.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT THU APR 9 2015
.UPDATE...THIS AFTERNOON
ISSUED AT 1242 PM CDT THU APR 9 2015
KEEPING A CLOSE EYE ON GRANT...CLAYTON...CRAWFORD...AND RICHLAND
COUNTIES THIS AFTERNOON FOR SEVERE THUNDERSTORM POTENTIAL. LATEST
MESOSCALE FORECAST MODELS SUGGEST STORMS WILL INITIATE OVER EAST
CENTRAL IOWA AND PUSH NORTH INTO THESE COUNTIES BY 3 TO 4 PM.
CURRENTLY THE WARM FRONT IS IN PLACE ACROSS NORTHERN ILLINOIS
INTO EAST CENTRAL IOWA AND IS MAKING NORTHWARD PROGRESS AS A
VIGOROUS SHORTWAVE LIFTS NORTHEAST OUT OF NEBRASKA. WE SHOULD SEE
A RAPIDLY DEEPENING SURFACE LOW LIFT ACROSS THE FORECAST AREA LATE
THIS AFTERNOON. 0-6 KM BULK SHEAR VALUES OF 40 TO 50 KTS WOULD
FAVOR SUPERCELLS AND WITH 0-1 KM BULK SHEAR VALUE APPROACHING 35
KTS THERE WILL BE MORE THAN ENOUGH SHEAR TO SUPPORT A TORNADO OR
TWO. HOWEVER SURFACE BASED CAPE LOOKS TO STAY JUST SOUTHEAST OF
THE FORECAST AREA WITH VALUES CLIMBING TO 2000-2500 J/KG ACROSS
NORTHERN ILLINOIS AND EAST CENTRAL IOWA. THE BIG QUESTION IS
WHETHER OR NOT WE CAN GET SURFACE BASED STORMS INTO GRANT COUNTY.
BEING THAT THIS AREA IS NEAR THE TRIPLE POINT WE WILL HAVE TO
KEEP A CLOSE EYE ON ANY STORMS IN THIS LOCATION WITH AN ENHANCED
POTENTIAL FOR A ISOLATED TORNADO. THE MORE FAVORABLE PARAMETERS
APPEAR TO BE ACROSS NORTHERN ILLINOIS AT THIS TIME. KEEP A CLOSE
EYE ON THE FORECAST THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU APR 9 2015
SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER
LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE
PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS
CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB
MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST
MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF
WISCONSIN INTO SOUTHERN MICHIGAN.
FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT
IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY
12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA
WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND
CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH
IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION
TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS
EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW.
NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN
AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN
THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z
TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE
FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS
MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST
UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST
AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF
1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK
THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR
IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE
THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL
TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN
MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST
WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING
WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME
SOUTHERN MOST FORECAST AREA.
FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE
SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED
SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER
DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF
PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE
LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC
BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE
09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND
CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER
WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH
POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS
EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2
INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN.
HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING
ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND
TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU APR 9 2015
AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO
CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW
MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT
SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW
SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND
EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT
EXIST.
SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT
LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES
ACROSS THE AREA.
NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY
INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL
RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH
THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES...
THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON
LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO
THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE
REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON
THIS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM CDT THU APR 9 2015
PERIODS OF IFR AND LIFR CONDITIONS ALONG WITH SHOWERS AND
THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS A STRONG LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. LOOK FOR WINDS TO INCREASE OUT
OF THE NORTHEAST AS THE LOW APPROACHES LATE THIS AFTERNOON THEN
TURN NORTHWEST AS THE LOW MOVES TO THE NORTHEAST OF THE REGION.
LOOK FOR NORTHWEST WINDS TO INCREASE TO 18 TO 23 KTS TONIGHT WITH
GUSTS OF AROUND 35 KTS POSSIBLE. MVFR CONDITIONS WILL RETURN LATE
TONIGHT INTO EARLY FRIDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...WETENKAMP
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...WETENKAMP