Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/24/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1109 PM MDT MON APR 21 2014
.UPDATE...
ISSUED AT 553 PM MDT MON APR 21 2014
JUST A QUICK UPDATE TO ADJUST THE POP GRIDS AND BRING IN THE
LATEST OBSERVATIONS. SHOWER ACTIVITY IS MAINLY CONFINED TO THE
PALMER DIVIDE...EASTERN MOUNTAINS AND SOUTHERN I-25 CORRIDOR. A
FEW LIGHTNING STRIKES HAVE ALSO BEEN NOTED. ANY PRECIPITATION THAT
FALLS WILL GENERALLY BE LIGHT AND NOT AMOUNT TO MUCH. MODELS IN
GOOD AGREEMENT WITH SHOWER ACTIVITY DISSIPATING AN HOUR OR SO
AFTER SUNSET. MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 328 PM MDT MON APR 21 2014
...INCREASING WINDS FOR TUESDAY...
UPPER RIDGE AXIS HAS BEEN SHIFTING EASTWARD ACROSS CO THIS AFTERNOON
WITH WEAK PV ANOMALY EXITING THE SOUTHEAST PLAINS. SFC DEW POINTS
HAVE DROPPED OFF INTO THE 20S ACROSS MOST OF THE AREA...WITH SOME
LOWER TO MID 30S ACROSS THE SOUTHERN PORTIONS OF THE SOUTHEAST
PLAINS AND SOUTHERN I-25 CORRIDOR. AFTERNOON HEATING HAS TRIGGERED
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS THE
MOUNTAINS...BUT WITH LACK OF FORCING COVERAGE HAS BEEN PRETTY SPARSE
AND LACK OF MOISTURE HAS LIMITED UPDRAFT STRENGTH. HRRR HAS BEEN
TRENDING DRIER WITH EACH RUN...SO HAVE DECREASED POPS FOR THE
EVENING HOURS...AND CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING
ONCE THE SUN GOES DOWN.
SOUTHWEST FLOW ALOFT INCREASES FOR TUESDAY...WHICH SHOULD INCREASE
WINDS ACROSS THE FORECAST AREA BY AFTERNOON. MOISTURE BEGINS TO
INCREASE ACROSS THE SOUTHWEST MOUNTAINS EARLY TUESDAY MORNING...WITH
SOME ISOLATED SHOWERS SPREADING IN. WITH AFTERNOON
HEATING...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON...THEN SPREAD OFF
INTO THE ADJACENT PLAINS DURING THE LATE AFTERNOON. ONE CONCERN FOR
TOMORROW IS THE POTENTIAL FOR NEAR CRITICAL FIRE WEATHER CONDITIONS
ALONG PORTIONS OF THE I-25 CORRIDOR. GFS IS DRIER WITH SFC DEW
POINTS (UPPER 20S)...WHILE NAM ACTUALLY INCREASES THEM IN THE
AFTERNOON (30S TO AROUND 40) AS CLOUDS INCREASE AND -SHRA/VIRGA
DRIFT OFF THE MOUNTAINS. LATEST 4KM WRF ALSO SHOWS THIS MOISTENING
TREND DURING THE AFTERNOON. FARTHER EAST...SOUTHERLY FLOW KEEPS MID-
UPPER 30S ACROSS THE FAR EAST PLAINS WHICH RESULTS IN AFTERNOON
HUMIDITIES IN THE 18-25% RANGE...TOO HIGH FOR FIRE WEATHER
HIGHLIGHTS. QUITE A BIT OF HUERFANO COUNTY HAD SOME GOOD RAIN FROM
THE SYSTEM OVER THE WEEKEND...SO THE MOST LIKE SPOTS FOR MARGINAL
CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP WOULD BE PUEBLO
COUNTY...SOUTHERN EL PASO...AND WESTERN LAS ANIMAS COUNTIES. LOCAL
WRF IS SLOW TO INCREASE WINDS ACROSS PUEBLO COUNTY UNTIL LATE
AFTERNOON WHICH MAY LIMIT THE DURATION TO LESS THAN THE 3 HR
REQUIRED MINIMUM. WITH ALL THESE MARGINAL CRITERIA...DECIDED NOT TO
HOIST ANY FIRE WEATHER HIGHLIGHTS...BUT THIS WILL BE MONITORED
CLOSELY AS MORE HIGH RES MODELS BEGIN TO RESOLVE THESE FINER
DETAILS.
OTHERWISE...ANOTHER ROUND OF ISOLATED TO SCATTERED AFTERNOON SHOWERS
AND THUNDERSTORMS WILL DEVELOP. THESE WILL BE PRETTY HIGH BASED AND
MORE LIKELY TO PRODUCE GUSTY WINDS AND LIGHTNING AND ONLY SOME BRIEF
LIGHT TO MODERATE RAINFALL AMOUNTS IN SPOTTY AREAS. A MARGINALLY
STRONG THUNDERSTORM OR TWO WILL BE POSSIBLE ALONG A DIFFUSE DRY LINE
ACROSS THE FAR SOUTHEAST PLAINS DURING THE AFTERNOON...BUT CAPES
WILL ONLY BE RUNNING AROUND 500 J/KG OR LESS...WITH GUSTY WINDS THE
PRIMARY STORM THREAT. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM MDT MON APR 21 2014
RELATIVELY ACTIVE LONGER TERM PATTERN SETTING UP OVER THE
FORECAST DISTRICT...ESPECIALLY FROM THE WEEKEND INTO EARLY NEXT
WEEK. PRIMARY LONGER TERM METEOROLOGICAL CHALLENGES INCLUDE BUT
ARE NOT LIMITED TO POPS...TEMPERATURES...ELEVATED FIRE WEATHER
CONCERNS AT TIMES AND THE POTENTIAL FOR SOME STRONG TO POTENTIALLY
SEVERE THUNDERSTORMS OVER/NEAR EASTERN SECTIONS AT TIMES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER MODEL
SIMULATIONS INDICATE THAT INITIAL UPPER DISTURBANCE WILL MOVE
PRIMARILY TO THE NORTH OF THE CWFA FROM WEDNESDAY INTO WEDNESDAY
NIGHT ALLOWING FOR SOME SHOWER ACTIVITY OVER MAINLY NORTHERN
SECTIONS AS WELL AS INCREASED DRY SOUTHWESTERLY SURFACE FLOW OVER
EASTERN PORTIONS OF THE FORECAST DISTRICT...THEREFORE WILL ALLOW
THE FIRE WEATHER WATCH TO REMAIN IN EFFECT FROM WEDNESDAY
AFTERNOON INTO WEDNESDAY EVENING FOR THE INTERSTATE 25 CORRIDOR AS
WELL AS OVER ALL OF THE SOUTHEASTERN COLORADO PLAINS. IN
ADDITION...A SURFACE DRY LINE IS EXPECTED TO SET-UP NEAR THE
COLORADO/KANSAS BORDER WEDNESDAY...WITH THE SPC DAY 3 CONVECTIVE
OUTLOOK PAINTING A SLIGHT RISK OF SEVERE THUNDERSTORMS ON
WEDNESDAY JUST EAST OF THE COLORADO/KANSAS BORDER. WFO PUEBLO
WILL MONITOR CLOSELY.
THEN BASICALLY DRY ZONAL TO SOUTHWESTERLY UPPER FLOW IS EXPECTED
TO DEVELOP OVER SOUTHERN COLORADO FROM LATER WEDNESDAY NIGHT INTO
SATURDAY MORNING IN ADVANCE OF NEXT APPROACHING SYSTEM. AT THIS
TIME WILL DEPICT GENERALLY DRY CONDITIONS DURING THIS TIME-FRAME
IN COMBINATION WITH ELEVATED FIRE WEATHER CONCERNS DURING THE
AFTERNOON AND EVENING HOURS OVER PORTIONS OF THE SAN LUIS VALLEY
AND SOUTHEASTERN COLORADO PLAINS.
NEXT POTENTIALLY SIGNIFICANT SYSTEM IS PROJECTED TO BEGIN IMPACTING
THE FORECAST DISTRICT FROM LATER SATURDAY INTO EARLY NEXT WEEK.
COMPUTER SIMULATIONS HAVE VARYING FORECAST TRACKS WITH THIS SYSTEM
WITH GFS FURTHEST SOUTH AND ECMWF AND DGEX FURTHER NORTH THROUGH
18Z NEXT MONDAY. WFO PUEBLO WILL CONTINUE TO CLOSELY MONITOR THE
TRACK AND STRENGTH OF THIS POTENTIAL SYSTEM AS IT NEARS THE
FORECAST DISTRICT BY THIS WEEKEND.
FINALLY...ABOVE SEASONAL LATE APRIL TEMPERATURES ARE PROJECTED TO
CONTINUE OVER THE MAJORITY OF THE FORECAST DISTRICT FROM TUESDAY
EVENING INTO SUNDAY MORNING WITH BELOW SEASONAL TEMPERATURES THEN
ANTICIPATED FROM LATER SUNDAY INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1108 PM MDT MON APR 21 2014
VFR CONDITIONS AT ALL THREE TERMINALS THROUGH TUESDAY MORNING.
BREEZY SOUTHWEST WINDS ARE FORECAST TO DEVELOP BY TUESDAY
AFTERNOON WITH GUSTS TO 30 KTS POSSIBLE AT KALS...AND 25 KTS AT
KCOS. IN ADDITION...SHOWER AND THUNDERSTORM ACTIVITY IS FORECAST
TO DEVELOP BY THE AFTERNOON HOURS OVER THE MOUNTAINS AND SPREAD
EAST INTO THE KALS AND KCOS REGIONS. THERE IS A LOW PROBABILITY
THAT ONE OF THESE SHOWERS WILL MOVE OVER THE TERMINALS AFTER 20Z
AND PRODUCE BRIEF PERIODS OF REDUCED CIGS AND VIS. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR COZ226>237.
&&
$$
UPDATE...MOZLEY
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS ALBANY NY
135 AM EDT TUE APR 22 2014
.SYNOPSIS...
DRY WEATHER WILL CONTINUE TONIGHT AS HIGH PRESSURE SLIDES OFF THE
COAST. SHOWERS WILL OVERSPREAD THE AREA ON TUESDAY...ESPECIALLY
DURING THE AFTERNOON...THEN CONTINUE INTO THE EVENING HOURS AS A LOW
PRESSURE SYSTEM AND ITS ASSOCIATED COLD FRONT MOVES ACROSS THE
REGION. COOLER AIR WILL BE USHERED INTO THE REGION BEHIND THIS
SYSTEM FOR THE MID WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 115 AM EDT...FOR THIS UPDATE NEEDED TO RAISE OVERNIGHT
TEMPERATURE SEVERAL DEGREES AS TEMPERATURES HAVE GENERALLY NOT
FALLEN MUCH AT ALL. THIS WAS DUE TO HIGH CLOUDS AND A PERSISTENT
SOUTHERLY BREEZE...DESPITE DEWPOINTS REMAINDER VERY LOW.
A FEW LIGHT SHOWERS (OR SPRINKLES) HAVE SKIMMED OUR NORTHERN AREAS
DUE TO A VERY WEAK DISTURBANCE. HOWEVER...THESE WERE MOVING
AWAY...AND THERE WERE NO MORE IMMEDIATELY UPSTREAM.
TRIMMED BACK THE ARRIVAL OF SHOWERS DUE TO THE INCREDIBLY LOW
DEWPOINTS...AND THE FACT THAT LATEST RUC INDICATED NO SHOWERS
REACHING OUR AREA UNTIL WELL AFTER DAYBREAK.
SO FOR THE REST OF THE OVERNIGHT...LOOK FOR TEMPERATURES TO SLOWLY
FALL...HIGH CLOUDS THICKEN...AND LOWS GENERALLY IN THE MID TO UPPER
40S...LOCALLY AROUND 50 AT ALBANY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE THROUGH
THE REGION TUESDAY AFTERNOON AND EVENING. HAVE FORECAST POPS TO
INCREASE TO LIKELY AND CATEGORICAL IN ALL AREAS DURING WEDNESDAY
AFTERNOON AND REMAIN HIGH INTO THE EVENING...THEN SLOWLY DECREASE
TUESDAY NIGHT AS THE TRAILING UPPER LEVEL TROF KEEPS SCT SHOWERS
LINGERING ACROSS THE REGION THROUGH THE NIGHT...ESPECIALLY ACROSS
HIGHER TERRAIN AREAS. WITH TEMPS COOLING HAVE ALSO FORECAST THE RAIN
SHOWERS CHANGING TO SNOW SHOWERS ACROSS THE ADIRONDACKS ZONES...WITH
MIXED RAIN/SNOW SHOWERS ACROSS HIGHER TERRAIN LOCATIONS FURTHER
SOUTH AND EAST. WITH COOL AND UNSTABLE CONDITIONS PERSISTING INTO
WEDNESDAY...WILL CONTINUE TO FORECAST SLIGHT TO LOW CHANCE POPS FOR
MOST OF THE REGION...ESPECIALLY HIGHER TERRAIN LOCATIONS. AS THE
SURFACE LOW DEEPENS OVER THE CANADIAN MARITIMES...IT WILL HELP
PRODUCE A STRONG GRADIENT ACROSS THE FORECAST AREA AND HAVE FORECAST
WIND GUSTS UP TO AROUND 40 MPH ON WEDNESDAY. HAVE HIGHLIGHTED THE
POTENTIAL FOR A WIND ADVISORY IN THE HWOALY PRODUCT IN CASE THE
WINDS BECOME STRONGER THAN CURRENTLY FORECAST.
HIGHS TUESDAY WILL BE IN THE UPPER 50S TO AROUND 70. LOWS TUESDAY
NIGHT IN THE MID 30S TO MID 40S. HIGHS WEDNESDAY ONLY IN THE MID 40S
TO THE 50S.
HIGHS PRESSURE BUILDS IN WEDNESDAY NIGHT WITH SKIES BECOMING MAINLY
CLEAR. LOWS WILL BE IN THE MID 20S TO LOWER 30S WITH GUSTY NORTHWEST
WINDS CONTINUING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LOW LEVEL RIDGING BUILDS INTO THE REGION THURSDAY...THEN BEGINS TO
BUILD EAST LATER THURSDAY AND THURSDAY NIGHT. SOME WEAK WARM
ADVECTION BEGINS LATER THURSDAY AND WITH DECENT SUNSHINE...HIGHS
THURSDAY ARE EXPECTED TO BE IN THE UPPER 50S TO AROUND 60 AROUND 50
IN NORTHERN AREAS.
BY FRIDAY...AN UPPER LEVEL SYSTEM AND ASSOCIATED COLD FRONT APPROACH
FROM THE GREAT LAKES...AND THE UPPER DYNAMICS AND LOW LEVEL FORCING
SHOULD SUPPORT SCATTERED SHOWERS. STILL...WITH SOME WARM BOUNDARY
LAYER TEMPERATURES AND AT LEAST SOME PARTIAL SUNSHINE...HIGHS IN THE
MID 50S TO LOWER 60S.
THEN...THE UPPER PATTERN BECOMES HIGH AMPLITUDE AND BLOCKY...WITH A
GENERAL CONSENSUS FOR AN UPPER LOW TO SPIN AROUND JUST OFFSHORE THE
NORTHEASTERN U.S....WITH ANOTHER PIECE OF UPPER ENERGY POSSIBLY
FORMING A NEW UPPER LOW OVER THE NORTHEASTERN U.S. LATER IN THE
WEEKEND. THERE IS QUITE A BIT OF SPREAD IN THE DETAILS OF THE
POSITION OF THE UPPER LOW...AND ITS PROXIMITY WILL DETERMINE WHETHER
WE HAVE DECENT COVERAGE OF INSTABILITY SHOWERS DURING THE DAY OR
ISOLATED COVERAGE.
SINCE THERE IS SUCH A SPREAD...JUST SUGGESTING PARTLY TO MOSTLY
CLOUDY DAYS AND PARTLY CLOUDY NIGHTS WITH SCATTERED SHOWERS EACH
DAY/AFTERNOON AND ISOLATED TO SCATTERED SHOWERS...POSSIBLE SNOW
SHOWERS IN THE HIGHER TERRAIN TO THE NORTH...AT NIGHT. HIGH
TEMPERATURES SATURDAY THROUGH MONDAY SHOULD BE A LITTLE BELOW NORMAL
WITH THE UPPER LOW/TROUGHING OVER THE REGION...THE MIXED CLOUD COVER
AND INSTABILITY DUE TO COLD AIR ALOFT AND SCATTERED SHOWERS. THERE
IS A POSSIBILITY THAT THE UPPER ENERGY COULD BE CENTERED FAR ENOUGH
OFFSHORE NEXT WEEKEND SO THAT WE WOULD HAVE MORE SUN...LESS COVERAGE
OF RAIN AND WARMER TEMPERATURES...BUT IT WILL JUST HAVE TO BE
WATCHED AS WE GET CLOSER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS THROUGH MOST OF THE FORECAST PERIOD...HOWEVER...COULD
SEE A PERIOD OF MVFR CIGS WITH FRONTAL PASSAGE AND SHOWERS THIS
AFTERNOON AND EARLY EVENING.
MAIN AVIATION IMPACT DURING THE NEXT 24 HOURS WILL BE THE APPROACH
AND PASSAGE OF THE COLD FRONT. UPSTREAM CONDITIONS HAVE BEEN AROUND
MVFR CIGS WITH A BRIEF VIS REDUCTION WITH THE SHOWERS. IN THE WAKE
OF THE FRONTAL PASSAGE...WINDS QUICKLY SHIFT FROM SOUTHERLY TO
WESTERLY WITH SPEEDS AROUND 10 MPH.
OUTLOOK...
TUESDAY OVERNT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
WEDNESDAY NIGHT TO THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY TO SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA.
&&
.FIRE WEATHER...
MOST OF OUR ENTIRE REGION IS SNOW FREE NOW (EXCEPT FOR SOME PATCHES
OF SNOW STILL LEFT IN THE WOODS OF THE ADIRONDACKS AND SOUTHERN
GREENS).
RH VALUES OF 15 TO 25 PERCENT LATE THIS AFTERNOON WILL RECOVER
MONDAY AFTERNOON...WITH A RECOVERY TO 75 TO 95 PERCENT TONIGHT.
THE WIND TONIGHT WILL SOUTHERLY AT 5 TO 15 MPH.
SHOWERS WILL OVERSPREAD THE AREA BY MIDDAY TUESDAY...THEN CONTINUE
INTO THE EVENING HOURS AS A LOW PRESSURE SYSTEM APPROACHES AND MOVES
ACROSS THE REGION. MOST AREAS LOOK TO RECEIVE A QUARTER INCH OR MORE
OF RAINFALL. RH VALUES WILL DROP TO AROUND 35 PERCENT OVER THE
SOUTHEAST...AND AROUND 55 PERCENT ACROSS THE NORTHWEST. WINDS WILL
BE SOUTHERLY AT 10 TO 15 MPH WITH GUSTS TO AROUND 25 MPH.
WEDNESDAY WILL BE BREEZY WITH A WIND OUT OF THE NORTHWEST AT 15 TO
25 MPH WITH GUSTS UP TO 40 MPH POSSIBLE.
&&
.HYDROLOGY...
THE LEVEL OF THE SCHROON RIVER AT RIVERBANK HAS DROPPED TO BELOW
FLOOD STAGE AND THE WARNING HAS BEEN DISCONTINUED.
DRY WEATHER WILL CONTINUE TO DOMINATE OUR WEATHER THROUGH TONIGHT.
SHOWERS ARE EXPECTED TO OVERSPREAD THE AREA BY MIDDAY TUESDAY
THEN CONTINUE INTO THE EVENING HOURS AS A LOW PRESSURE SYSTEM
APPROACHES AND MOVES ACROSS THE REGION. GENERALLY QPF AMOUNTS OF A
QUARTER TO A HALF AN INCH ARE EXPECTED.
THIS RAIN WILL ONLY BRING MINOR WITHIN BANKFULL RISES ON SOME RIVERS
AND STREAMS.
DRY WEATHER RETURNS ON WEDNESDAY.
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...HWJIV/GJM
NEAR TERM...HWJIV
SHORT TERM...GJM
LONG TERM...NAS
AVIATION...BGM
FIRE WEATHER...HWJIV/GJM
HYDROLOGY...HWJIV/GJM
AREA FORECAST DISCUSSION
NWS ALBANY NY
115 AM EDT TUE APR 22 2014
.SYNOPSIS...
DRY WEATHER WILL CONTINUE TONIGHT AS HIGH PRESSURE SLIDES OFF THE
COAST. SHOWERS WILL OVERSPREAD THE AREA ON TUESDAY...ESPECIALLY
DURING THE AFTERNOON...THEN CONTINUE INTO THE EVENING HOURS AS A LOW
PRESSURE SYSTEM AND ITS ASSOCIATED COLD FRONT MOVES ACROSS THE
REGION. COOLER AIR WILL BE USHERED INTO THE REGION BEHIND THIS
SYSTEM FOR THE MID WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 115 AM EDT...FOR THIS UPDATE NEEDED TO RAISE OVERNIGHT
TEMPERATURE SEVERAL DEGREES AS TEMPERATURES HAVE GENERALLY NOT
FALLEN MUCH AT ALL. THIS WAS DUE TO HIGH CLOUDS AND A PERSISTENT
SOUTHERLY BREEZE...DESPITE DEWPOINTS REMAINDER VERY LOW.
A FEW LIGHT SHOWERS (OR SPRINKLES) HAVE SKIMMED OUR NORTHERN AREAS
DUE TO A VERY WEAK DISTURBANCE. HOWEVER...THESE WERE MOVING
AWAY...AND THERE WERE NO MORE IMMEDIATELY UPSTREAM.
TRIMMED BACK THE ARRIVAL OF SHOWERS DUE TO THE INCREDIBLY LOW
DEWPOINTS...AND THE FACT THAT LATEST RUC INDICATED NO SHOWERS
REACHING OUR AREA UNTIL WELL AFTER DAYBREAK.
SO FOR THE REST OF THE OVERNIGHT...LOOK FOR TEMPERATURES TO SLOWLY
FALL...HIGH CLOUDS THICKEN...AND LOWS GENERALLY IN THE MID TO UPPER
40S...LOCALLY AROUND 50 AT ALBANY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE THROUGH
THE REGION TUESDAY AFTERNOON AND EVENING. HAVE FORECAST POPS TO
INCREASE TO LIKELY AND CATEGORICAL IN ALL AREAS DURING WEDNESDAY
AFTERNOON AND REMAIN HIGH INTO THE EVENING...THEN SLOWLY DECREASE
TUESDAY NIGHT AS THE TRAILING UPPER LEVEL TROF KEEPS SCT SHOWERS
LINGERING ACROSS THE REGION THROUGH THE NIGHT...ESPECIALLY ACROSS
HIGHER TERRAIN AREAS. WITH TEMPS COOLING HAVE ALSO FORECAST THE RAIN
SHOWERS CHANGING TO SNOW SHOWERS ACROSS THE ADIRONDACKS ZONES...WITH
MIXED RAIN/SNOW SHOWERS ACROSS HIGHER TERRAIN LOCATIONS FURTHER
SOUTH AND EAST. WITH COOL AND UNSTABLE CONDITIONS PERSISTING INTO
WEDNESDAY...WILL CONTINUE TO FORECAST SLIGHT TO LOW CHANCE POPS FOR
MOST OF THE REGION...ESPECIALLY HIGHER TERRAIN LOCATIONS. AS THE
SURFACE LOW DEEPENS OVER THE CANADIAN MARITIMES...IT WILL HELP
PRODUCE A STRONG GRADIENT ACROSS THE FORECAST AREA AND HAVE FORECAST
WIND GUSTS UP TO AROUND 40 MPH ON WEDNESDAY. HAVE HIGHLIGHTED THE
POTENTIAL FOR A WIND ADVISORY IN THE HWOALY PRODUCT IN CASE THE
WINDS BECOME STRONGER THAN CURRENTLY FORECAST.
HIGHS TUESDAY WILL BE IN THE UPPER 50S TO AROUND 70. LOWS TUESDAY
NIGHT IN THE MID 30S TO MID 40S. HIGHS WEDNESDAY ONLY IN THE MID 40S
TO THE 50S.
HIGHS PRESSURE BUILDS IN WEDNESDAY NIGHT WITH SKIES BECOMING MAINLY
CLEAR. LOWS WILL BE IN THE MID 20S TO LOWER 30S WITH GUSTY NORTHWEST
WINDS CONTINUING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LOW LEVEL RIDGING BUILDS INTO THE REGION THURSDAY...THEN BEGINS TO
BUILD EAST LATER THURSDAY AND THURSDAY NIGHT. SOME WEAK WARM
ADVECTION BEGINS LATER THURSDAY AND WITH DECENT SUNSHINE...HIGHS
THURSDAY ARE EXPECTED TO BE IN THE UPPER 50S TO AROUND 60 AROUND 50
IN NORTHERN AREAS.
BY FRIDAY...AN UPPER LEVEL SYSTEM AND ASSOCIATED COLD FRONT APPROACH
FROM THE GREAT LAKES...AND THE UPPER DYNAMICS AND LOW LEVEL FORCING
SHOULD SUPPORT SCATTERED SHOWERS. STILL...WITH SOME WARM BOUNDARY
LAYER TEMPERATURES AND AT LEAST SOME PARTIAL SUNSHINE...HIGHS IN THE
MID 50S TO LOWER 60S.
THEN...THE UPPER PATTERN BECOMES HIGH AMPLITUDE AND BLOCKY...WITH A
GENERAL CONSENSUS FOR AN UPPER LOW TO SPIN AROUND JUST OFFSHORE THE
NORTHEASTERN U.S....WITH ANOTHER PIECE OF UPPER ENERGY POSSIBLY
FORMING A NEW UPPER LOW OVER THE NORTHEASTERN U.S. LATER IN THE
WEEKEND. THERE IS QUITE A BIT OF SPREAD IN THE DETAILS OF THE
POSITION OF THE UPPER LOW...AND ITS PROXIMITY WILL DETERMINE WHETHER
WE HAVE DECENT COVERAGE OF INSTABILITY SHOWERS DURING THE DAY OR
ISOLATED COVERAGE.
SINCE THERE IS SUCH A SPREAD...JUST SUGGESTING PARTLY TO MOSTLY
CLOUDY DAYS AND PARTLY CLOUDY NIGHTS WITH SCATTERED SHOWERS EACH
DAY/AFTERNOON AND ISOLATED TO SCATTERED SHOWERS...POSSIBLE SNOW
SHOWERS IN THE HIGHER TERRAIN TO THE NORTH...AT NIGHT. HIGH
TEMPERATURES SATURDAY THROUGH MONDAY SHOULD BE A LITTLE BELOW NORMAL
WITH THE UPPER LOW/TROUGHING OVER THE REGION...THE MIXED CLOUD COVER
AND INSTABILITY DUE TO COLD AIR ALOFT AND SCATTERED SHOWERS. THERE
IS A POSSIBILITY THAT THE UPPER ENERGY COULD BE CENTERED FAR ENOUGH
OFFSHORE NEXT WEEKEND SO THAT WE WOULD HAVE MORE SUN...LESS COVERAGE
OF RAIN AND WARMER TEMPERATURES...BUT IT WILL JUST HAVE TO BE
WATCHED AS WE GET CLOSER.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR TAF PERIOD ENDING
00Z WEDNESDAY. HIGH AND MID LEVEL CLOUDS WILL GRADUALLY INCREASE
ACROSS THE REGION THROUGH TONIGHT. CIGS WILL LOWER ON TUESDAY AHEAD
OF A COLD FRONT APPROACHING FROM THE GREAT LAKES AND OHIO
VALLEY...BUT WILL REMAIN IN VFR RANGE THROUGH 18Z TUESDAY. ONLY SITE
WHERE VCSH WILL BE MENTIONED BEFORE 18Z IS AT KGFL...WHERE A SHOWER
OR TWO COULD DEVELOP. MORE WIDESPREAD SHOWERS ARE EXPECTED TO IMPACT
THE TERMINALS AFTER 18Z TUESDAY.
WINDS THROUGH THE REST OF TODAY WILL BE SOUTHERLY AROUND 5-10
KT...BECOMING LIGHT AND VARIABLE TONIGHT. WINDS ON TUESDAY WILL BE
SOUTH-SOUTHWEST AROUND 10 KT.
OUTLOOK...
TUESDAY PM: HIGH OPERATIONAL IMPACT. OCNL SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
WEDNESDAY NIGHT TO THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY TO SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA.
&&
.FIRE WEATHER...
MOST OF OUR ENTIRE REGION IS SNOW FREE NOW (EXCEPT FOR SOME PATCHES
OF SNOW STILL LEFT IN THE WOODS OF THE ADIRONDACKS AND SOUTHERN
GREENS).
RH VALUES OF 15 TO 25 PERCENT LATE THIS AFTERNOON WILL RECOVER
MONDAY AFTERNOON...WITH A RECOVERY TO 75 TO 95 PERCENT TONIGHT.
THE WIND TONIGHT WILL SOUTHERLY AT 5 TO 15 MPH.
SHOWERS WILL OVERSPREAD THE AREA BY MIDDAY TUESDAY...THEN CONTINUE
INTO THE EVENING HOURS AS A LOW PRESSURE SYSTEM APPROACHES AND MOVES
ACROSS THE REGION. MOST AREAS LOOK TO RECEIVE A QUARTER INCH OR MORE
OF RAINFALL. RH VALUES WILL DROP TO AROUND 35 PERCENT OVER THE
SOUTHEAST...AND AROUND 55 PERCENT ACROSS THE NORTHWEST. WINDS WILL
BE SOUTHERLY AT 10 TO 15 MPH WITH GUSTS TO AROUND 25 MPH.
WEDNESDAY WILL BE BREEZY WITH A WIND OUT OF THE NORTHWEST AT 15 TO
25 MPH WITH GUSTS UP TO 40 MPH POSSIBLE.
&&
.HYDROLOGY...
THE LEVEL OF THE SCHROON RIVER AT RIVERBANK HAS DROPPED TO BELOW
FLOOD STAGE AND THE WARNING HAS BEEN DISCONTINUED.
DRY WEATHER WILL CONTINUE TO DOMINATE OUR WEATHER THROUGH TONIGHT.
SHOWERS ARE EXPECTED TO OVERSPREAD THE AREA BY MIDDAY TUESDAY
THEN CONTINUE INTO THE EVENING HOURS AS A LOW PRESSURE SYSTEM
APPROACHES AND MOVES ACROSS THE REGION. GENERALLY QPF AMOUNTS OF A
QUARTER TO A HALF AN INCH ARE EXPECTED.
THIS RAIN WILL ONLY BRING MINOR WITHIN BANKFULL RISES ON SOME RIVERS
AND STREAMS.
DRY WEATHER RETURNS ON WEDNESDAY.
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...HWJIV/GJM
NEAR TERM...HWJIV
SHORT TERM...GJM
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...HWJIV/GJM
HYDROLOGY...HWJIV/GJM
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1030 AM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION FROM THE WEST TODAY AND
CROSS THE AREA THIS EVENING. HIGH PRESSURE WILL THEN BUILD IN
BEHIND THE FRONT FOR WEDNESDAY AND THURSDAY. THE HIGH COMBINED
WITH LOW PRESSURE EAST OF NEW ENGLAND WILL RESULT IN GUSTY
NORTHWEST WINDS. ANOTHER AREA OF LOW PRESSURE WILL MOVE TO THE
NORTH AND BRING A WEAK FRONT THROUGH THE REGION FRIDAY NIGHT INTO
EARLY SATURDAY, FOLLOWED BY MORE HIGH PRESSURE AND FAIR WEATHER
FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON RADAR TRENDS AND HRRR GUIDANCE, WE TRIMMED BACK POPS AND
ONSET OF PRECIP FOR OUR WESTERN ZONES LATE MORNING/EARLY AFTN. WE
ALSO MADE SOME ADJUSTMENTS TO POPS THROUGH THE AFTN TO EVENING
HOURS TO REFLECT THE TIMING OF THE FRONT THROUGH THE CWA.
OTHERWISE, PRECIP AMOUNTS LOOK TO BE ON TRACK FOR LATER TODAY AS
MODEL GUIDANCE CONTINUES TO SHOW LIMITED MOISTURE ASSOCIATED WITH
THE FRONTAL PASSAGE. WE ALSO KEPT THE MENTION OF THUNDER FOR THE
AFTN/EVE AS GFS/NAM AND EURO GUIDANCE INDICATES SOME INSTABILITY.
IN ADDITION, HOURLY TEMPS/DEWPOINTS WERE ADJUSTED SOMEWHAT TO
REFLECT CURRENT OBSERVATIONS AND TRENDS, BUT AFTN MAXIMUM TEMPS
LOOK ON TRACK.
OTHERWISE, DEEPENING LOW PRESSURE WILL MOVE ACROSS NY AND NEW
ENGLAND TODAY AND AN ATTACHED COLD FRONT WILL APPROACH FROM THE
WEST. THE FRONT WILL CROSS THE WRN AREAS LATE THIS AFTERNOON.
OVERALL, MAINLY HIGH CHC/LIKELY POPS ARE IN PLACE WITH THE FRONTAL
PASSAGE AND SMALLER CHCS FOR THUNDER. SPC HAS ONLY A GENERAL
THUNDER OUTLOOKED FOR OUR REGION...WITH LIMITED CAPE AND MODEST
WIND FIELDS EXPECTED. THE FRONT WILL REACH THE DEL VALLEY AROUND
23Z OR 00Z. WINDS WILL BE MOSTLY S/SW TODAY THEN SHIFT WRLY AFTER
FROPA. OVERALL QPF TODAY AND THIS EVENING WILL BE MOSTLY .10 TO
.25 INCHES.
TEMPERATURES TODAY WILL BE MUCH ABOVE NORMAL WITH HIGHS EXPECTED TO
REACH THE LOW/MID 70S IN MANY AREAS. IT WILL REMAIN COOLER ALONG THE
SHORE AREAS WITH READINGS THERE STAYING MOSTLY IN THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE COLD FRONT WILL CONTINUE TO MOVE EAST ACROSS NJ/DE THEN OFFSHORE
OVERNIGHT. MUCH OF THE SHOWER AND ISOLATED TSTM ACTIVITY WILL OCCUR
THIS EVENING. A COLDER GUSTY NW WIND WILL COMMENCE BEHIND THE FRONT.
WIND GUSTS OF 20 TO 25 MPH ARE POSSIBLE BY LATE TONIGHT. THE
TEMPERATURES WILL FALL THROUGH THE 50S REACHING THE MID/UPPER 40S BY
MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE BUILDING INTO THE MIDWEST AT THE START OF
THE EXTENDD PD AS LOW PRES DEEPENS OVER NEW ENG AND PULLS AWAY.
THE PGRAD BETWEEN THE DEVELOPING LOW AND THE BUILDING HIGH WILL
KEEP GUSTY N TO NW WIND OVER THE REGION BOTH DAYS. 30 TO 35 MPH
GUSTS ARE PSBL, BEFORE THE WIND SETTLES DOWN ON THU.
BY THU NIGHT, AN AREA OF LOW PRES WILL BE MOVG ACRS THE GRTLKS AND
ITS ASSOCD CDFNT WILL APPROACH THE REGION ON FRI AND CROSS THE
AREA FRI NIGHT INTO EARLY SAT. THIS FRONT WILL BRING ANOTHER CHC
OF SHWRS. THERE IS VERY GOOD MDL AGREEMENT ON THIS PART OF THE
FCST. HOWEVER, THERE IS MUCH LESS MDL AGREEMENT ON WHAT HAPPENS
THE REST OF SAT. THE GFS SWEEPS THE FRONT THRU AND KEEPS MOST OF
THE REST OF SAT DRY, SAVE FOR A FEW SCT SHWRS. THE ECMWF, ON THE
OTHER HAND BRINGS A SECOND FRONT BY DURG SAT AND WOULD KEEP THE
THREAT OF SHOWERS ALL DAY AND MUCH HIGHER POPS. THE CMC SUPPORTS
THE DRIER GFS SOLN, SO FOR NOW, WILL GO WITH LOW CHC POPS, BUT SAT
COULD END UP WETTER THAN CURRENTLY FCST AND CONFIDENCE IS LOW.
THEN HIGH PRES BEGINS TO BUILD DOWN FROM CAN FOR SUN MAKING FOR
ANOTHER DRY DAY ACRS THE AREA.
BY MON, THERE IS YET EVEN MORE MDL DISAGREEMENT. AN AREA OF LOW
PRES TAKES SHAPE ACRS THE PLAINS. IT`S WARM FRONT EXTENDS EWD AND
PRECIP IS EXPECTED ALG AND N OF THAT BOUNDARY ON MON. HOWEVER, THE
GUID DIFFERS AS TO WHERE THE FRONT WILL BE AND, THEREFORE, WHERE
THE PRECIP WILL BE. THE ECMWF IS FURTHER S WITH THE FRONT AND THE
PRECIP THAN THE GFS AND KEEPS VIRTUALLY ALL OF OUR AREA DRY ON
MON, WITH THE PSBL EXCEPTION OF THE EXTREME SRN DELMARVA. THE GFS
IS MUCH FURTHER N AND KEEPS THE AREA WET.
THE ULTIMATE POSN OF THE FRONT AND PRECIP WILL BE GOVERNED BY THE
STRENGTH AND POSN OF THE AFOREMENTIONED HIGH OVER CANADA. IF ITS
STRONGER OR FURTHER S, THEN THE FRONT WILL BE FURTHER S. IF ITS
WEAKER OR FURTHER N, THEN THE FRONT WILL BE FURTHER N. GIVEN THE
NORMAL UNCERTAINTY AT THIS TIME SCALE AND THE DIAMETRIC OPPOSITE
GUIDANCE, WILL JUST CARRY SOME LOW POPS ATTM.
AFTER WED, BEHIND THE CFP....TEMPS LOOK TO BE AOA NRML THRU THE
PD. SAT`S TEMP ULTIMATELY DEPENDENT ON SUNSHINE AND WHICH MDL SOLN
IS CORRECT.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
A MOSTLY VFR DAY IS EXPECTED AT THE TERMINALS. A COLD FRONT WILL
APPROACH FROM THE WEST THIS AFTERNOON CAUSING CLOUDS TO INCREASE
AND CIGS TO LOWER. WE HAVE CONTINUED WITH VFR CONDITIONS DURING
THE SHOWERY PERIOD LATER TODAY...ISOLATED TSTMS ARE EXPECTED. LOW
CONFID IN THUNDER FOR THE TAF SITES...SO THEY WERE NOT MENTIONED
IN THE TAFS FOR NOW. WINDS WILL BE MOSTLY S/SW TODAY THEN SWITCH
WRLY THIS EVENING BEFORE BECOMING GUSTY NW TONIGHT BEHIND THE
FRONT. WINDS GUSTS BETWEEN 20 AND 25 KTS POSSIBLE LATE TONIGHT.
OUTLOOK...
WED THROUGH THU...VFR CONDS WITH NW WINDS IN THE 20 TO 30 KT
RANGE. HIGH CONFIDENCE.
FRI THROUGH SAT...MAINLY VFR BUT LOCALLY MVFR IN SCATTERED
SHOWERS FRI NIGHT INTO EARLY SAT. MDT CONFIDENCE.
&&
.MARINE...
OVERALL, SUB-SCA CONDITIONS ARE EXPECTED ON THE AREA WATERS
THROUGH TODAY BEFORE WINDS AND SEAS INCREASE FOLLOWING A COLD
FRONTAL PASSAGE LATER TONIGHT. LATEST OBSERVATIONS FROM BUOY 44009
SHOW SEAS BETWEEN 4 TO 5 FEET, AND THIS WILL LIKELY HOLD FOR THE
OUTER WATERS THROUGH THE AFTERNOON BEFORE MORE WIDESPREAD ELEVATED
SEAS DEVELOP LATE TONIGHT AND THROUGH WEDNESDAY.
WINDS WILL ALSO INCREASE TONIGHT BEHIND THE COLD FRONT. A SCA
FLAG WILL BE IN EFFECT FOR ALL WATERS AFTER 00Z AND CARRY INTO WED
MORNING. SCT SHOWERS AND ISOLATED TSTMS ARE EXPECTED LATE THIS
AFTERNOON AND EARLY EVENING.
OUTLOOK...
WED THROUGH THU...SCA LIKELY AND GALE FORCE GSTS PSBL ON THE OCEAN
FRONT WITH GUSTS AROUND 35 KT AND PSBLY HIGHER. A GALE WATCH HAS
BEEN ISSUED. WIND SUBSIDING LATER THU.
FRI AND SAT...NO MARINE HEADLINES ARE ANTICIPATED AT THIS TIME,
THOUGH WE COULD APPROACH SCA WIND BY SAT NIGHT.
&&
.FIRE WEATHER...
SOME FIRE WEATHER DANGER MAY BE PRESENT ON WEDNESDAY AND THURSDAY.
GUSTY NORTHWEST WINDS WILL BE PRESENT BOTH DAYS BUT SOMEWHAT
STRONGER ON WEDNESDAY. GUSTS COULD REACH OVER 30 MPH. HOWEVER...AT
THIS TIME IT LOOKS LIKE RH VALUES MAY STAY ABOVE 30 PERCENT ON
WEDNESDAY. RH WILL BE LOWER ON THURSDAY WITH ADDITIONAL DRYING
AFTER TUESDAYS PRECIP...AND STILL GUSTY NW WINDS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR
ANZ450>455.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 AM EDT
WEDNESDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 AM EDT
THURSDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...KLINE/O`HARA
SHORT TERM...O`HARA
LONG TERM...NIERENBERG
AVIATION...NIERENBERG/O`HARA
MARINE...KLINE/NIERENBERG/O`HARA
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
958 PM EDT WED APR 23 2014
.UPDATE...
QUIET WEATHER PATTERN WITH MILD TEMPS THIS EVENING. THE 0Z JAX
SOUNDING SHOWED AN EXTREMELY STRONG SUBSIDENCE INVERSION NEAR 7000
FEET WITH VERY DRY AIR ALOFT. THIS SUBSIDENCE IS SHOWING UP VERY
NICELY ON WATER VAPOR IMAGERY THIS EVENING. NO PRECIP WAS OBSERVED
TODAY AND NONE IS EXPECTED OVERNIGHT. MOSTLY CLEAR SKIES AND CALM
WINDS WILL EVENTUALLY LEAD TO SOME FOG DEVELOPMENT OVERNIGHT. MOST
OF THE FOG WILL BE PATCHY IN NATURE BUT THE HRRR IS SHOWING AN
INCREASED CHANCE FOR FOG ALONG THE I-75 CORRIDOR LATE TONIGHT.
CONDITIONS ARE DEFINITELY FAVORABLE FOR THIS TO PLAY
OUT...ESPECIALLY GIVEN THE HIGHER LOW LEVEL MOISTURE IN PLACE
COURTESY OF THE GULF COAST SEABREEZE. WITH THIS IN MIND...WE HAVE
INCREASED THE FOG WORDING TO INCLUDE AREAS OF FOG ACROSS THE I-75
CORRIDOR REGION. SOME LOCALLY DENSE FOG WILL ALSO BE POSSIBLE
THERE.
&&
.AVIATION...
VFR EXPECTED FOR EAST COAST TERMINALS DUE TO CLEAR SKIES AND LIGHT
WINDS. AREAS OF FOG MOVING INLAND FROM THE WEST COAST WILL LEAD TO
VSBY RESTRICTIONS AT GNV. HAVE MVFR AT THIS TIME...BUT NOW HAVE MORE
CONFIDENCE FOR LIFR VSBY BETWEEN 09Z-13Z AND CIGS BKN002. EXPECT
MVFR AT VQQ AND NO CIGS.
&&
.MARINE...
OFFSHORE WINDS ARE 10-15 KTS OVER THE OUTER WATERS AND 5-10 KTS
NEAR THE COAST. EAST SWELLS ARE CONTRIBUTING TO COMBINED SEAS OF
2 FT NEARSHORE AND 3-5 FT OFFSHORE. WINDS WILL INCREASE AHEAD OF
THE FRONT TONIGHT...BUT SHOULD PEAK BELOW EXERCISE CAUTION LEVELS.
WINDS WILL THEN DECREASE AND VEER TO ONSHORE FOR WEDNESDAY.
RIP CURRENTS: A MODERATE RISK OF RIP CURRENTS IS POSSIBLE AGAIN
ON THURSDAY DUE TO LINGERING EAST SWELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 57 83 61 85 / 0 20 20 10
SSI 63 74 65 78 / 0 10 10 10
JAX 62 80 61 85 / 0 20 20 10
SGJ 65 76 64 84 / 0 20 20 10
GNV 60 84 60 86 / 10 20 20 0
OCF 61 85 61 86 / 0 30 30 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHULER/TRABERT/
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
915 PM EDT WED APR 23 2014
.UPDATE (REST OF TONIGHT AND THURSDAY)...
00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A LARGE RIDGE OF HIGH
PRESSURE IN CONTROL OVER THE NORTHERN GULF COAST AND FL PENINSULA.
THE ONLY SIGNIFICANT WEATHER ONGOING ACROSS THE CONUS IS OCCURRING
ACROSS THE WESTERN PLAINS AS THUNDERSTORMS ERUPT AHEAD OF A STRONG
SHORTWAVE TROUGH EJECTING EASTWARD FROM THE INTER-MOUNTAIN WEST.
BACK CLOSER TO HOME...WV IMAGERY SHOWS A SWATH OF VERY DRY MID/UPPER
LEVEL AIR STREAMING OVER THE NORTHERN GULF AND FL PENINSULA. THIS
DRY AIR ALOFT IS VERY EVIDENT IN THE 00Z KTBW SOUNDING PROFILE ABOVE
600MB.
AT THE SURFACE...A WEAK QUASI-STATIONARY FRONTAL BOUNDARY JUST NORTH
OF I-10 WILL DECAY OVERNIGHT WHILE HIGH PRESSURE REMAINS IN CONTROL
OF THE FL PENINSULA. NO SIGNIFICANT WEATHER CONCERNS ARE ANTICIPATED
FOR MUCH OF THE OVERNIGHT WITH MOSTLY CLEAR SKIES...LIGHT WINDS AND
SEASONABLE TEMPERATURES. THERE ARE SOME INDICATIONS THAT LATE AT
NIGHT WE WILL SEE THE DEVELOPMENT OF PATCHY/AREAS OF GROUND FOG.
SOME OF THIS FOG MAY BECOME LOCALLY DENSE IN THE NORMALLY FOG PRONE
AREAS...AND THIS LOWERED VISIBILITY DURING THE MORNING COMMUTE WILL
BE THE ONLY REAL SENSIBLE WEATHER CONCERN HEADING INTO THURSDAY.
AFTER ANY EARLY MORNING FOG BURNS OFF...THE REST OF THURSDAY WILL
FEATURE A MIX OF SUN AND CLOUDS AND WARM TEMPERATURES. AFTERNOON
HIGH TEMPS WILL BE INTO THE 80S AWAY FROM THE BEACHES AND IN THE
UPPER 70S TO NEAR 80 ALONG THE WATER. LOCAL HIGH RESOLUTION MODEL
GUIDANCE IS SHOWING A WELL DEFINED SEA-BREEZE CIRCULATION
DEVELOPING ALONG BOTH THE EAST AND WEST COAST OF THE PENINSULA THAT
WILL BOTH PROPAGATE INLAND AND COLLIDE ACROSS THE INTERIOR PENINSULA
AFTER 21Z. EXPECT THE MIX OF SUN AND CLOUDS NEAR THE COAST EARLY IN
THE AFTERNOON TO BECOME MOSTLY SUNNY AS THE SEA-BREEZE BOUNDARY
MOVES INLAND...BUT IT WILL BECOME RATHER GUSTY AT AREA BEACHES IN
ITS WAKE. ACROSS THE INTERIOR...A FEW SEA-BREEZE COLLISION SHOWERS
ARE EVEN POSSIBLE DURING THE LATE AFTERNOON/EARLY EVENING AS LOW
LEVEL MOISTURE WILL BE HIGHER THAN TODAY AND SURFACE CONVERGENCE
SHOULD BE MORE DEFINED. MOISTURE ALOFT WILL STILL BE LACKING..SO ANY
SHOWERS ARE LIKELY TO BE LOW TOPPED AND BRIEF IN NATURE. MANY OF THE
LOCAL AND NATIONAL CONVECTION ALLOWING MODELS SUPPORT THIS IDEA OF
SCT LATE DAY SHOWERS WELL INLAND AND THE CURRENT FORECAST GRIDS WILL
SHOW THIS CHANCE.
ANY EVENING SHOWERS WILL DISSIPATE QUICKLY AFTER 00Z WITH THE LOSS
OF DIURNAL HEATING AND THE RESULTING DECREASE IN SEA-BREEZE
CONVERGENCE.
&&
.AVIATION...
VFR TO PREVAIL AREA WIDE AS CLOUDS ARE FEW AND FAR BETWEEN THIS
EVENING. KEPT MENTION OF BR IN FORECAST AT LAL AND PGD STARTING
AROUND 09Z. THIS COULD RESULT IN LOCALIZED REDUCTIONS TO MVFR.
OTHERWISE LIGHT AND VARIABLE WINDS OVERNIGHT WILL BECOME WESTERLY
TOMORROW AFTN AS SEABREEZE DEVELOPMENT IS EXPECTED.
&&
.MARINE...
LIGHT WINDS AND SEAS ARE EXPECTED THROUGH THE NEXT SEVERAL DAYS.
THE ONLY MODERATE WINDS WILL BE ASSOCIATED CLOSE TO THE COAST WITH
AFTERNOON DEVELOPMENT OF THE DAILY SEA BREEZE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 66 83 68 84 / 0 10 0 10
FMY 65 87 66 88 / 0 10 0 10
GIF 66 86 66 86 / 0 30 20 10
SRQ 63 79 65 81 / 0 10 0 10
BKV 57 85 58 84 / 0 10 10 10
SPG 68 82 69 83 / 0 10 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...MCKAUGHAN
AREA FORECAST DISCUSSION
NWS MIAMI FL
136 PM EDT TUE APR 22 2014
.AVIATION...
VFR CIGS ALONG THE EAST COAST AND THESE WILL BEGIN TO CLEAR OUT
ONCE A SEA BREEZE CAN DEVELOP LATER THIS AFTERNOON. THAT IS THE
BURNING QUESTION, WHEN WILL THE EAST COAST SEA BREEZE FORM? IT IS
CURRENTLY STRUGGLING TO FORM ON THE IMMEDIATE COASTLINE BUT HAVING
A HARD TIME DUE TO THE BKN-OVC CLOUD CONDITIONS. SO WITH TIME, IT
MAY BE ABLE TO MOVE A FEW MILES INLAND. SURFACE WIND AFT 00Z WILL
AGAIN BECOME L/V WITH A WESTERLY COMPONENT THROUGH EARLY
WEDNESDAY MORNING.
KOB
&&
.PREV DISCUSSION... /ISSUED 941 AM EDT TUE APR 22 2014/
UPDATE...
QUIET WEATHER THIS MORNING...GRIDS HAVE BEEN UPDATED TO REFLECT
CURRENT OBSERVATIONS...OTHERWISE NO CHANGES TO OVERALL FORECAST.
PREV DISCUSSION... /ISSUED 724 AM EDT TUE APR 22 2014/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST. A FEW SHOWERS
MOVING SOUTH ACROSS THE ATLANTIC BUT FAR ENOUGH OFFSHORE THAT DID
NOT INCLUDE VCSH FOR ANY OF THE TERMINALS. HOWEVER, THERE WILL
LIKELY BE BKN050 NEAR FLL AS A CLUSTER OF CU HUGS THE COAST THIS
MORNING. SURFACE WINDS ARE GOING TO BE RATHER ERRATIC ALONG THE
EAST COAST TODAY WITH GUIDANCE SHOWING A SEA BREEZE DEVELOPING BUT
MOST OF THE HIGH RESOLUTION SHORT TERM MODELS NOT SHOWING IT MOVING
INLAND VERY FAR.
KOB
PREV DISCUSSION... /ISSUED 413 AM EDT TUE APR 22 2014/
DISCUSSION...
SCATTERED LIGHT TO MODERATE SHOWERS CONTINUE TO SLOWLY PUSH TO THE
SOUTH ACROSS THE ATLANTIC WATERS THIS MORNING. THE LATEST HRRR KEEPS
THESE SHOWERS GOING THROUGH THE MORNING. ALSO PATCHY SMOKE COULD BE
AN ISSUE DURING THE MORNING HOURS MAINLY ALONG SOUTHEASTERN MIAMI-
DADE COUNTY DUE TO AN ONGOING BRUSH FIRE.
WINDS SHOULD REMAIN FAIRLY LIGHT THROUGH THE DAY AND VARIABLE ALONG
THE EAST COAST AS A SEA BREEZE TRIES TO SET UP. OTHERWISE...DRY AND
SEASONABLE CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY DUE TO HIGH
PRESSURE ACROSS THE GULF OF MEXICO. A WEAK H5 SHORTWAVE IS STILL
EXPECTED TO SWING SOUTH AND INTO NORTHERN FLORIDA LATE TONIGHT AND
INTO EARLY WEDNESDAY. THIS WILL ALLOW A COLD FRONT TO PUSH INTO
NORTH CENTRAL FLORIDA AND STALL LATE WEDNESDAY. AS THE FRONT
LINGERS...A FEW SHOWERS MAY BE POSSIBLE ACROSS THE PENINSULA INTO
THURSDAY BUT KEPT FORECAST DRY FOR NOW.
MODEST UPPER RIDGING THEN BEGINS TO BUILD ACROSS THE AREA FRIDAY
INTO THE WEEKEND WITH CONTINUED DRY WEATHER AND TEMPERATURES SEVERAL
DEGREES ABOVE NORMAL. SURFACE HIGH PRESSURE THEN BECOMES ENTRENCHED
ACROSS THE WESTERN ATLANTIC ALLOWING SOUTHEASTERLY FLOW TO INCREASE
LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. A RESULTANT INCREASE
IN MOISTURE COMBINED WITH A MORE ORGANIZED COLD FRONT ENTERING THE
CENTRAL GULF OF MEXICO WILL RESULT IN SLIGHT CHANCES FOR SHOWERS
TUESDAY AFTERNOON.
MARINE...
ADVISORY LEVEL SEAS WILL CONTINUE ACROSS THE GULF STREAM THROUGH THE
MORNING DUE TO A LONG PERIOD NORTHEASTERLY SWELL. WINDS ACROSS THE
ATLANTIC ARE EXPECTED TO DECREASE THROUGH THE AFTERNOON WHICH
WILL ALLOW SEAS TO DIMINISH BELOW ADVISORY LEVELS. THEREFORE WILL
ALLOW SMALL CRAFT ADVISORY TO EXPIRE AT 11 AM.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
941 AM EDT TUE APR 22 2014
.UPDATE...
QUIET WEATHER THIS MORNING...GRIDS HAVE BEEN UPDATED TO REFLECT
CURRENT OBSERVATIONS...OTHERWISE NO CHANGES TO OVERALL FORECAST.
&&
.PREV DISCUSSION... /ISSUED 724 AM EDT TUE APR 22 2014/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST. A FEW SHOWERS
MOVING SOUTH ACROSS THE ATLANTIC BUT FAR ENOUGH OFFSHORE THAT DID
NOT INCLUDE VCSH FOR ANY OF THE TERMINALS. HOWEVER, THERE WILL
LIKELY BE BKN050 NEAR FLL AS A CLUSTER OF CU HUGS THE COAST THIS
MORNING. SURFACE WINDS ARE GOING TO BE RATHER ERRATIC ALONG THE
EAST COAST TODAY WITH GUIDANCE SHOWING A SEA BREEZE DEVELOPING BUT
MOST OF THE HIGH RESOLUTION SHORT TERM MODELS NOT SHOWING IT MOVING
INLAND VERY FAR.
KOB
PREV DISCUSSION... /ISSUED 413 AM EDT TUE APR 22 2014/
DISCUSSION...
SCATTERED LIGHT TO MODERATE SHOWERS CONTINUE TO SLOWLY PUSH TO THE
SOUTH ACROSS THE ATLANTIC WATERS THIS MORNING. THE LATEST HRRR KEEPS
THESE SHOWERS GOING THROUGH THE MORNING. ALSO PATCHY SMOKE COULD BE
AN ISSUE DURING THE MORNING HOURS MAINLY ALONG SOUTHEASTERN MIAMI-
DADE COUNTY DUE TO AN ONGOING BRUSH FIRE.
WINDS SHOULD REMAIN FAIRLY LIGHT THROUGH THE DAY AND VARIABLE ALONG
THE EAST COAST AS A SEA BREEZE TRIES TO SET UP. OTHERWISE...DRY AND
SEASONABLE CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY DUE TO HIGH
PRESSURE ACROSS THE GULF OF MEXICO. A WEAK H5 SHORTWAVE IS STILL
EXPECTED TO SWING SOUTH AND INTO NORTHERN FLORIDA LATE TONIGHT AND
INTO EARLY WEDNESDAY. THIS WILL ALLOW A COLD FRONT TO PUSH INTO
NORTH CENTRAL FLORIDA AND STALL LATE WEDNESDAY. AS THE FRONT
LINGERS...A FEW SHOWERS MAY BE POSSIBLE ACROSS THE PENINSULA INTO
THURSDAY BUT KEPT FORECAST DRY FOR NOW.
MODEST UPPER RIDGING THEN BEGINS TO BUILD ACROSS THE AREA FRIDAY
INTO THE WEEKEND WITH CONTINUED DRY WEATHER AND TEMPERATURES SEVERAL
DEGREES ABOVE NORMAL. SURFACE HIGH PRESSURE THEN BECOMES ENTRENCHED
ACROSS THE WESTERN ATLANTIC ALLOWING SOUTHEASTERLY FLOW TO INCREASE
LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. A RESULTANT INCREASE
IN MOISTURE COMBINED WITH A MORE ORGANIZED COLD FRONT ENTERING THE
CENTRAL GULF OF MEXICO WILL RESULT IN SLIGHT CHANCES FOR SHOWERS
TUESDAY AFTERNOON.
MARINE...
ADVISORY LEVEL SEAS WILL CONTINUE ACROSS THE GULF STREAM THROUGH THE
MORNING DUE TO A LONG PERIOD NORTHEASTERLY SWELL. WINDS ACROSS THE
ATLANTIC ARE EXPECTED TO DECREASE THROUGH THE AFTERNOON WHICH
WILL ALLOW SEAS TO DIMINISH BELOW ADVISORY LEVELS. THEREFORE WILL
ALLOW SMALL CRAFT ADVISORY TO EXPIRE AT 11 AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 65 83 69 / 10 0 10 10
FORT LAUDERDALE 81 69 83 71 / 10 0 10 10
MIAMI 83 69 84 71 / 10 0 10 10
NAPLES 82 64 81 66 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT THIS
MORNING FOR AMZ650-651-670-671.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
724 AM EDT TUE APR 22 2014
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST. A FEW SHOWERS
MOVING SOUTH ACROSS THE ATLANTIC BUT FAR ENOUGH OFFSHORE THAT DID
NOT INCLUDE VCSH FOR ANY OF THE TERMINALS. HOWEVER, THERE WILL
LIKELY BE BKN050 NEAR FLL AS A CLUSTER OF CU HUGS THE COAST THIS
MORNING. SURFACE WINDS ARE GOING TO BE RATHER ERRATIC ALONG THE
EAST COAST TODAY WITH GUIDANCE SHOWING A SEA BREEZE DEVELOPING BUT
MOST OF THE HIGH RESOLUTION SHORT TERM MODELS NOT SHOWING IT MOVING
INLAND VERY FAR.
KOB
&&
.PREV DISCUSSION... /ISSUED 413 AM EDT TUE APR 22 2014/
DISCUSSION...
SCATTERED LIGHT TO MODERATE SHOWERS CONTINUE TO SLOWLY PUSH TO THE
SOUTH ACROSS THE ATLANTIC WATERS THIS MORNING. THE LATEST HRRR KEEPS
THESE SHOWERS GOING THROUGH THE MORNING. ALSO PATCHY SMOKE COULD BE
AN ISSUE DURING THE MORNING HOURS MAINLY ALONG SOUTHEASTERN MIAMI-
DADE COUNTY DUE TO AN ONGOING BRUSH FIRE.
WINDS SHOULD REMAIN FAIRLY LIGHT THROUGH THE DAY AND VARIABLE ALONG
THE EAST COAST AS A SEA BREEZE TRIES TO SET UP. OTHERWISE...DRY AND
SEASONABLE CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY DUE TO HIGH
PRESSURE ACROSS THE GULF OF MEXICO. A WEAK H5 SHORTWAVE IS STILL
EXPECTED TO SWING SOUTH AND INTO NORTHERN FLORIDA LATE TONIGHT AND
INTO EARLY WEDNESDAY. THIS WILL ALLOW A COLD FRONT TO PUSH INTO
NORTH CENTRAL FLORIDA AND STALL LATE WEDNESDAY. AS THE FRONT
LINGERS...A FEW SHOWERS MAY BE POSSIBLE ACROSS THE PENINSULA INTO
THURSDAY BUT KEPT FORECAST DRY FOR NOW.
MODEST UPPER RIDGING THEN BEGINS TO BUILD ACROSS THE AREA FRIDAY
INTO THE WEEKEND WITH CONTINUED DRY WEATHER AND TEMPERATURES SEVERAL
DEGREES ABOVE NORMAL. SURFACE HIGH PRESSURE THEN BECOMES ENTRENCHED
ACROSS THE WESTERN ATLANTIC ALLOWING SOUTHEASTERLY FLOW TO INCREASE
LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. A RESULTANT INCREASE
IN MOISTURE COMBINED WITH A MORE ORGANIZED COLD FRONT ENTERING THE
CENTRAL GULF OF MEXICO WILL RESULT IN SLIGHT CHANCES FOR SHOWERS
TUESDAY AFTERNOON.
AVIATION...
HIGH PRESSURE WILL WEAKEN A BIT TODAY AS A COUPLE OF WEAK SURFACE
TROUGHS MOVE ACROSS THE AREA. WINDS WILL BECOME MORE WESTERLY IN
NATURE TODAY, BUT REMAIN FAIRLY WEAK, BETWEEN 5 AND 10 KTS. ALONG
THE ATLANTIC COAST, A WEAK SEA BREEZE LOOKS TO TRY TO DEVELOP THIS
AFTERNOON. THIS COULD WREAK HAVOC WITH WIND DIRECTION AS THE
EASTERLY FLOW FROM THE SEA BREEZE BATTLES THE WESTERLY FLOW. GIVEN
THIS, HAVE MAINLY A SSE FLOW ALONG MOST OF THE ATLANTIC SITES INTO
THE EVENING HOURS, THEN BECOMING MORE LIGHT AND VARIABLE FOR THE
LATE EVENING, INTO TONIGHT. OTHERWISE, VFR CONDITIONS EXPECTED
THROUGH THE TAF PERIOD.
MARINE...
ADVISORY LEVEL SEAS WILL CONTINUE ACROSS THE GULF STREAM THROUGH THE
MORNING DUE TO A LONG PERIOD NORTHEASTERLY SWELL. WINDS ACROSS THE
ATLANTIC ARE EXPECTED TO DECREASE THROUGH THE AFTERNOON WHICH
WILL ALLOW SEAS TO DIMINISH BELOW ADVISORY LEVELS. THEREFORE WILL
ALLOW SMALL CRAFT ADVISORY TO EXPIRE AT 11 AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 65 83 69 / 10 0 10 10
FORT LAUDERDALE 81 69 83 71 / 10 0 10 10
MIAMI 83 69 84 71 / 10 0 10 10
NAPLES 82 64 81 66 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT THIS
MORNING FOR AMZ650-651-670-671.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
413 AM EDT TUE APR 22 2014
.DISCUSSION...
SCATTERED LIGHT TO MODERATE SHOWERS CONTINUE TO SLOWLY PUSH TO THE
SOUTH ACROSS THE ATLANTIC WATERS THIS MORNING. THE LATEST HRRR KEEPS
THESE SHOWERS GOING THROUGH THE MORNING. ALSO PATCHY SMOKE COULD BE
AN ISSUE DURING THE MORNING HOURS MAINLY ALONG SOUTHEASTERN MIAMI-
DADE COUNTY DUE TO AN ONGOING BRUSH FIRE.
WINDS SHOULD REMAIN FAIRLY LIGHT THROUGH THE DAY AND VARIABLE ALONG
THE EAST COAST AS A SEA BREEZE TRIES TO SET UP. OTHERWISE...DRY AND
SEASONABLE CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY DUE TO HIGH
PRESSURE ACROSS THE GULF OF MEXICO. A WEAK H5 SHORTWAVE IS STILL
EXPECTED TO SWING SOUTH AND INTO NORTHERN FLORIDA LATE TONIGHT AND
INTO EARLY WEDNESDAY. THIS WILL ALLOW A COLD FRONT TO PUSH INTO
NORTH CENTRAL FLORIDA AND STALL LATE WEDNESDAY. AS THE FRONT
LINGERS...A FEW SHOWERS MAY BE POSSIBLE ACROSS THE PENINSULA INTO
THURSDAY BUT KEPT FORECAST DRY FOR NOW.
MODEST UPPER RIDGING THEN BEGINS TO BUILD ACROSS THE AREA FRIDAY
INTO THE WEEKEND WITH CONTINUED DRY WEATHER AND TEMPERATURES SEVERAL
DEGREES ABOVE NORMAL. SURFACE HIGH PRESSURE THEN BECOMES ENTRENCHED
ACROSS THE WESTERN ATLANTIC ALLOWING SOUTHEASTERLY FLOW TO INCREASE
LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. A RESULTANT INCREASE
IN MOISTURE COMBINED WITH A MORE ORGANIZED COLD FRONT ENTERING THE
CENTRAL GULF OF MEXICO WILL RESULT IN SLIGHT CHANCES FOR SHOWERS
TUESDAY AFTERNOON.
&&
.AVIATION...
HIGH PRESSURE WILL WEAKEN A BIT TODAY AS A COUPLE OF WEAK SURFACE
TROUGHS MOVE ACROSS THE AREA. WINDS WILL BECOME MORE WESTERLY IN
NATURE TODAY, BUT REMAIN FAIRLY WEAK, BETWEEN 5 AND 10 KTS. ALONG
THE ATLANTIC COAST, A WEAK SEA BREEZE LOOKS TO TRY TO DEVELOP THIS
AFTERNOON. THIS COULD WREAK HAVOC WITH WIND DIRECTION AS THE
EASTERLY FLOW FROM THE SEA BREEZE BATTLES THE WESTERLY FLOW. GIVEN
THIS, HAVE MAINLY A SSE FLOW ALONG MOST OF THE ATLANTIC SITES INTO
THE EVENING HOURS, THEN BECOMING MORE LIGHT AND VARIABLE FOR THE
LATE EVENING, INTO TONIGHT. OTHERWISE, VFR CONDITIONS EXPECTED
THROUGH THE TAF PERIOD.
&&
.MARINE...
ADVISORY LEVEL SEAS WILL CONTINUE ACROSS THE GULF STREAM THROUGH THE
MORNING DUE TO A LONG PERIOD NORTHEASTERLY SWELL. WINDS ACROSS THE
ATLANTIC ARE EXPECTED TO DECREASE THROUGH THE AFTERNOON WHICH
WILL ALLOW SEAS TO DIMINISH BELOW ADVISORY LEVELS. THEREFORE WILL
ALLOW SMALL CRAFT ADVISORY TO EXPIRE AT 11 AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 65 83 69 / 10 0 10 10
FORT LAUDERDALE 81 69 83 71 / 10 0 10 10
MIAMI 83 69 84 71 / 10 0 10 10
NAPLES 82 64 81 66 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT THIS
MORNING FOR AMZ650-651-670-671.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AVIATION...13/SI
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
245 PM EDT TUE APR 22 2014
.PREV DISCUSSION... /ISSUED 402 AM EDT TUE APR 22 2014/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS CURRENTLY SITUATED ALONG THE GULF COAST. A FRONTAL
BOUNDARY STRETCHES FROM THE GREAT LAKES BACK THROUGH THE ARKLATEX.
THIS FRONT WILL MOVE EASTWARD TODAY...AND SHOULD MOVE THROUGH THE
CWFA LATE TODAY/THIS EVENING. REGIONAL RADAR SHOWS SHRA/TSRA ALONG A
PRE-FRONTAL TROUGH ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. IN
ADDITION...A FEW SHOWERS HAVE DEVELOPED ACROSS NORTHERN AL AHEAD A
SHORTWAVE. SFC/500MB ANALYSIS SHOWS THE FRONT IS DRAPED ALONG THE
MID LEVEL TROUGH.
MODELS HAVE TRENDED SLOWER OVER THE LAST SEVERAL RUNS WITH THE
PRECIP. THIS SEEMS REASONABLE...AS THE FRONT IS STILL WELL BACK TO
THE WEST. LATEST RUNS OF THE HRRR SEEM TO HAVE A DECENT HANDLE ON
THE CURRENT CONDITIONS...SO HAVE FOLLOWED RATHER CLOSELY FOR THE
TIMING OF THE POPS. MODELS ALSO DIMINISH THE COVERAGE OF STORMS A
BIT AS THE BOUNDARY MOVES SOUTH ACROSS GA. THIS HAS ALSO BEEN A
TREND OVER THE LAST SEVERAL DAYS...AS THE MAIN ENERGY REMAINS WELL
TO THE NORTH.
STILL EXPECT A FEW STRONG THUNDERSTORMS...BUT SEVERE WEATHER IS NOT
ANTICIPATED. MID LEVEL LAPSE RATES HAVE STEEPENED SLIGHTLY...BUT
SURFACE INSTABILITY REMAINS MARGINAL...AND THE SHEAR AND UPPER
FORCING REMAIN WEAK.
PRECIP SHOULD TAPER OFF LATER THIS EVENING AS THE FRONTAL BOUNDARY
PUSHES ACROSS SOUTHERN GA AND HIGH PRESSURE BUILDS IN FROM THE
NORTH. THE BOUNDARY LOOKS TO BECOME NEARLY STATIONARY FOR THE
REMAINDER OF THE SHORT TERM PERIOD.
NLISTEMAA
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL START THE EXTENDED FORECAST BUT THINGS WILL
CHANGE BY THE END OF THE WORK WEEK AND INTO THE WEEKEND. THE HIGH
PRESSURE RIDGE WILL DOMINATE THE WEATHER PATTERN WED AND THU
KEEPING THE AREA PRECIPITATION FREE. THIS RIDGE EVENTUALLY MOVES
EAST OFF THE MID ATLANTIC COAST AND BECOMES CENTERED JUST OFF THE
CAROLINA/GEORGIA COAST BY 00Z FRI. THE NEXT FRONTAL SYSTEM TO
AFFECT THE AREA BEGINS DEVELOPING OVER THE PLAINS STATES WED
AFTERNOON. THE MAIN LOW CENTER DEEPENS AND MOVES NE TO THE GREAT
LAKE STATES THU AFTERNOON WITH THE TAIL END OF THE COLD FRONT
PUSHING INTO NW GA BY 06Z TO 12Z FRI. THE MODELS ARE STILL
SHOWING A DECENT AMOUNT OF INSTABILITY WITH THE FRI SYSTEM SO WILL
KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST. THE MODELS ARE
ALSO STILL NOT SHOWING MUCH AVAILABLE MOISTURE SO WE SHOULD NOT SEE
ANY ISSUES WITH FLOODING. THERE IS ANOTHER WEAKER FRONTAL BOUNDARY
THAT MOVES IN SAT MORNING WHICH HELPS TO REINFORCE THE FIRST ONE
AND KEEP CHANCES FOR PRECIPITATION ACROSS THE AREA THROUGH THE
BEGINNING OF NEXT WEEK. THIS PATTERN IS BEGINNING TO LOOK MORE LIKE A
SUMMERTIME PATTERN THAN A SPRING PATTERN WITH DECENT CAPE AND LOW
SHEAR. STARTING FRIDAY...CAPES AND LIS PEAK EVERYDAY AROUND 18Z
AND FALL OFF RAPIDLY BY 00Z. TEMPS ALSO LOOK MORE LIKE SUMMER
BEGINNING THU WITH HIGHS MAINLY IN THE 80S. LOWS WILL BE IN THE 50S
AND 60S.
01
.AVIATION...
18Z UPDATE...
WEAK COLD FRONT PUSHING ACROSS GEORGIA THIS AFTERNOON WITH SHOWERS
AND A FEW THUNDERSTORMS. MVFR CIGS SHOULD PREVAIL WITH SOME AREAS OF
IFR IN RAIN. GRADUAL IMPROVING AFTER 00Z. THE FRONT SHOULD MOVE
SOUTH OF THE TERMINAL SITES LATE THIS EVENING...AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. NORTHWEST WINDS THROUGH THE FORECAST
PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON PRECIP TIMING AND CIGS. HIGH CONFIDENCE
REMAINING ELEMENTS.
41
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 79 51 76 53 / 60 30 0 0
ATLANTA 77 51 74 55 / 60 30 0 0
BLAIRSVILLE 68 43 70 45 / 60 30 5 0
CARTERSVILLE 74 49 73 48 / 60 30 0 0
COLUMBUS 78 56 79 57 / 50 40 5 0
GAINESVILLE 74 49 75 54 / 60 30 0 0
MACON 80 55 79 53 / 50 50 5 0
ROME 75 48 73 46 / 60 30 0 5
PEACHTREE CITY 76 51 76 51 / 60 30 5 0
VIDALIA 83 59 80 59 / 50 50 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
729 AM EDT TUE APR 22 2014
.PREV DISCUSSION... /ISSUED 402 AM EDT TUE APR 22 2014/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS CURRENTLY SITUATED ALONG THE GULF COAST. A FRONTAL
BOUNDARY STRETCHES FROM THE GREAT LAKES BACK THROUGH THE ARKLATEX.
THIS FRONT WILL MOVE EASTWARD TODAY...AND SHOULD MOVE THROUGH THE
CWFA LATE TODAY/THIS EVENING. REGIONAL RADAR SHOWS SHRA/TSRA ALONG A
PRE-FRONTAL TROUGH ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. IN
ADDITION...A FEW SHOWERS HAVE DEVELOPED ACROSS NORTHERN AL AHEAD A
SHORTWAVE. SFC/500MB ANALYSIS SHOWS THE FRONT IS DRAPED ALONG THE
MID LEVEL TROUGH.
MODELS HAVE TRENDED SLOWER OVER THE LAST SEVERAL RUNS WITH THE
PRECIP. THIS SEEMS REASONABLE...AS THE FRONT IS STILL WELL BACK TO
THE WEST. LATEST RUNS OF THE HRRR SEEM TO HAVE A DECENT HANDLE ON
THE CURRENT CONDITIONS...SO HAVE FOLLOWED RATHER CLOSELY FOR THE
TIMING OF THE POPS. MODELS ALSO DIMINISH THE COVERAGE OF STORMS A
BIT AS THE BOUNDARY MOVES SOUTH ACROSS GA. THIS HAS ALSO BEEN A
TREND OVER THE LAST SEVERAL DAYS...AS THE MAIN ENERGY REMAINS WELL
TO THE NORTH.
STILL EXPECT A FEW STRONG THUNDERSTORMS...BUT SEVERE WEATHER IS NOT
ANTICIPATED. MID LEVEL LAPSE RATES HAVE STEEPENED SLIGHTLY...BUT
SURFACE INSTABILITY REMAINS MARGINAL...AND THE SHEAR AND UPPER
FORCING REMAIN WEAK.
PRECIP SHOULD TAPER OFF LATER THIS EVENING AS THE FRONTAL BOUNDARY
PUSHES ACROSS SOUTHERN GA AND HIGH PRESSURE BUILDS IN FROM THE
NORTH. THE BOUNDARY LOOKS TO BECOME NEARLY STATIONARY FOR THE
REMAINDER OF THE SHORT TERM PERIOD.
NLISTEMAA
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL START THE EXTENDED FORECAST BUT THINGS WILL
CHANGE BY THE END OF THE WORK WEEK AND INTO THE WEEKEND. THE HIGH
PRESSURE RIDGE WILL DOMINATE THE WEATHER PATTERN WED AND THU
KEEPING THE AREA PRECIPITATION FREE. THIS RIDGE EVENTUALLY MOVES
EAST OFF THE MID ATLANTIC COAST AND BECOMES CENTERED JUST OFF THE
CAROLINA/GEORGIA COAST BY 00Z FRI. THE NEXT FRONTAL SYSTEM TO
AFFECT THE AREA BEGINS DEVELOPING OVER THE PLAINS STATES WED
AFTERNOON. THE MAIN LOW CENTER DEEPENS AND MOVES NE TO THE GREAT
LAKE STATES THU AFTERNOON WITH THE TAIL END OF THE COLD FRONT
PUSHING INTO NW GA BY 06Z TO 12Z FRI. THE MODELS ARE STILL
SHOWING A DECENT AMOUNT OF INSTABILITY WITH THE FRI SYSTEM SO WILL
KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST. THE MODELS ARE
ALSO STILL NOT SHOWING MUCH AVAILABLE MOISTURE SO WE SHOULD NOT SEE
ANY ISSUES WITH FLOODING. THERE IS ANOTHER WEAKER FRONTAL BOUNDARY
THAT MOVES IN SAT MORNING WHICH HELPS TO REINFORCE THE FIRST ONE
AND KEEP CHANCES FOR PRECIPITATION ACROSS THE AREA THROUGH THE
BEGINNING OF NEXT WEEK. THIS PATTERN IS BEGINNING TO LOOK MORE LIKE A
SUMMERTIME PATTERN THAN A SPRING PATTERN WITH DECENT CAPE AND LOW
SHEAR. STARTING FRIDAY...CAPES AND LIS PEAK EVERYDAY AROUND 18Z
AND FALL OFF RAPIDLY BY 00Z. TEMPS ALSO LOOK MORE LIKE SUMMER
BEGINNING THU WITH HIGHS MAINLY IN THE 80S. LOWS WILL BE IN THE 50S
AND 60S.
01
.AVIATION...
12Z UPDATE...
COLD FRONT CURRENTLY ACROSS CENTRAL MISSISSIPPI WILL CROSS THE
REGION TODAY. DIDN`T MAKE MANY CHANGES TO THE ONGOING TAF...PRECIP
TIMING STILL LOOKS GOOD. MVFR CIGS STILL LOOK POSSIBLE WITH
THUNDERSTORMS. THE FRONT SHOULD MOVE SOUTH OF THE TERMINAL SITES
BY THE EVENING...AS HIGH PRESSURE BUILDS IN FROM THE NORTH. NW
WINDS BEHIND THE FRONT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON PRECIP TIMING AND CIGS. HIGH CONFIDENCE
REMAINING ELEMENTS.
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 79 51 76 53 / 60 30 0 0
ATLANTA 77 51 74 55 / 60 30 0 0
BLAIRSVILLE 68 43 70 45 / 60 30 5 0
CARTERSVILLE 74 49 73 48 / 60 30 0 0
COLUMBUS 78 56 79 57 / 50 40 5 0
GAINESVILLE 74 49 75 54 / 60 30 0 0
MACON 80 55 79 53 / 50 50 5 0
ROME 75 48 73 46 / 60 30 0 5
PEACHTREE CITY 76 51 76 51 / 60 30 5 0
VIDALIA 83 59 80 59 / 50 50 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
402 AM EDT TUE APR 22 2014
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS CURRENTLY SITUATED ALONG THE GULF COAST. A FRONTAL
BOUNDARY STRETCHES FROM THE GREAT LAKES BACK THROUGH THE ARKLATEX.
THIS FRONT WILL MOVE EASTWARD TODAY...AND SHOULD MOVE THROUGH THE
CWFA LATE TODAY/THIS EVENING. REGIONAL RADAR SHOWS SHRA/TSRA ALONG A
PRE-FRONTAL TROUGH ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. IN
ADDITION...A FEW SHOWERS HAVE DEVELOPED ACROSS NORTHERN AL AHEAD A
SHORTWAVE. SFC/500MB ANALYSIS SHOWS THE FRONT IS DRAPED ALONG THE
MID LEVEL TROUGH.
MODELS HAVE TRENDED SLOWER OVER THE LAST SEVERAL RUNS WITH THE
PRECIP. THIS SEEMS REASONABLE...AS THE FRONT IS STILL WELL BACK TO
THE WEST. LATEST RUNS OF THE HRRR SEEM TO HAVE A DECENT HANDLE ON
THE CURRENT CONDITIONS...SO HAVE FOLLOWED RATHER CLOSELY FOR THE
TIMING OF THE POPS. MODELS ALSO DIMINISH THE COVERAGE OF STORMS A
BIT AS THE BOUNDARY MOVES SOUTH ACROSS GA. THIS HAS ALSO BEEN A
TREND OVER THE LAST SEVERAL DAYS...AS THE MAIN ENERGY REMAINS WELL
TO THE NORTH.
STILL EXPECT A FEW STRONG THUNDERSTORMS...BUT SEVERE WEATHER IS NOT
ANTICIPATED. MID LEVEL LAPSE RATES HAVE STEEPENED SLIGHTLY...BUT
SURFACE INSTABILITY REMAINS MARGINAL...AND THE SHEAR AND UPPER
FORCING REMAIN WEAK.
PRECIP SHOULD TAPER OFF LATER THIS EVENING AS THE FRONTAL BOUNDARY
PUSHES ACROSS SOUTHERN GA AND HIGH PRESSURE BUILDS IN FROM THE
NORTH. THE BOUNDARY LOOKS TO BECOME NEARLY STATIONARY FOR THE
REMAINDER OF THE SHORT TERM PERIOD.
NLISTEMAA
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL START THE EXTENDED FORECAST BUT THINGS WILL
CHANGE BY THE END OF THE WORK WEEK AND INTO THE WEEKEND. THE HIGH
PRESSURE RIDGE WILL DOMINATE THE WEATHER PATTERN WED AND THU
KEEPING THE AREA PRECIPITATION FREE. THIS RIDGE EVENTUALLY MOVES
EAST OFF THE MID ATLANTIC COAST AND BECOMES CENTERED JUST OFF THE
CAROLINA/GEORGIA COAST BY 00Z FRI. THE NEXT FRONTAL SYSTEM TO
AFFECT THE AREA BEGINS DEVELOPING OVER THE PLAINS STATES WED
AFTERNOON. THE MAIN LOW CENTER DEEPENS AND MOVES NE TO THE GREAT
LAKE STATES THU AFTERNOON WITH THE TAIL END OF THE COLD FRONT
PUSHING INTO NW GA BY 06Z TO 12Z FRI. THE MODELS ARE STILL
SHOWING A DECENT AMOUNT OF INSTABILITY WITH THE FRI SYSTEM SO WILL
KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST. THE MODELS ARE
ALSO STILL NOT SHOWING MUCH AVAILABLE MOISTURE SO WE SHOULD NOT SEE
ANY ISSUES WITH FLOODING. THERE IS ANOTHER WEAKER FRONTAL BOUNDARY
THAT MOVES IN SAT MORNING WHICH HELPS TO REINFORCE THE FIRST ONE
AND KEEP CHANCES FOR PRECIPITATION ACROSS THE AREA THROUGH THE
BEGINNING OF NEXT WEEK. THIS PATTERN IS BEGINNING TO LOOK MORE LIKE A
SUMMERTIME PATTERN THAN A SPRING PATTERN WITH DECENT CAPE AND LOW
SHEAR. STARTING FRIDAY...CAPES AND LIS PEAK EVERYDAY AROUND 18Z
AND FALL OFF RAPIDLY BY 00Z. TEMPS ALSO LOOK MORE LIKE SUMMER
BEGINNING THU WITH HIGHS MAINLY IN THE 80S. LOWS WILL BE IN THE 50S
AND 60S.
01
&&
.AVIATION...
06Z UPDATE...
COLD FRONT WILL MOVE THROUGH THE REGION TODAY. MODELS HAVE TRENDED
WITH SLOWING THE PRECIP ASSOCIATED WITH THE BOUNDARY DOWN...AND
LATEST TAF SET REFLECTS THAT TREND. FORECAST SOUNDINGS ALSO DONT
REALLY SHOW PREDOMINATE MVFR CIGS...BUT COULD OCCUR WITHIN ANY
THUNDERSTORMS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON PRECIP TIMING AND CIGS. HIGH CONFIDENCE
REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 79 51 76 53 / 60 30 0 0
ATLANTA 77 51 74 55 / 60 30 0 0
BLAIRSVILLE 68 43 70 45 / 60 30 5 0
CARTERSVILLE 74 49 73 48 / 60 30 0 0
COLUMBUS 78 56 79 57 / 50 40 5 0
GAINESVILLE 74 49 75 54 / 60 30 0 0
MACON 80 55 79 53 / 50 50 5 0
ROME 75 48 73 46 / 60 30 0 5
PEACHTREE CITY 76 51 76 51 / 60 30 5 0
VIDALIA 83 59 80 59 / 50 50 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....01
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1012 PM CDT WED APR 23 2014
.DISCUSSION...
931 PM CDT
SHOWERS CONTINUE TO MOVE/DEVELOP EASTWARD ACROSS NORTHERN ILLINOIS
EARLY THIS EVENING WITHIN A ZONE OF INCREASING ISENTROPIC ASCENT
ALONG THE WESTERN PERIPHERY OF A SURFACE RIDGE OF HIGH PRESSURE. THIS
ACTIVITY IS EXPECTED TO CONTINUE MOVING EASTWARD ACROSS NORTHERN
ILLINOIS LATE THIS EVENING...AND LIKELY ENDING PRIOR TO DAYBREAK
THURSDAY AS THE BETTER FORCING AND MOISTENING SHIFTS TO THE NORTH
AND EAST OF THE REGION. THEREFORE...NO BIG CHANGES ARE NEEDED TO THE
GOING FORECAST FOR TONIGHT.
THURSDAY IS SHAPING UP TO BE A BREEZY AND A MILDER DAY ACROSS THE
AREA AS SOUTHEASTERLY FLOW RAMPS UP IN RESPONSE TO AN AREA OF LOW
PRESSURE APPROACHING WESTERN ILLINOIS DURING THE AFTERNOON. IT
APPEARS THAT IN SPITE OF THE SOUTH-SOUTHEASTERLY WIND
COMPONENT...THAT WINDS COULD BE VERY GUSTY...UP IN THE 30 TO 35 KT
RANGE...DURING THE AFTERNOON. ALSO...IT APPEARS THAT THESE
SOUTHEASTERLY WINDS WILL TRANSPORT A DRIER LOWER LEVEL AIR MASS IN
ACROSS THE AREA DURING THE DAY...AND THIS COULD LEAD TO LOWER
SURFACE DEW POINTS THAN CURRENTLY FORECAST...ESPECIALLY ACROSS THE
EASTERN HALF OF THE AREA. WITH THIS IN MIND...I HAVE BACKED OFF ON
POPS DURING THE AFTERNOON THURSDAY...WITH A LIKELY SLOWER EVOLUTION
OF THE PRECIPITATION. IT APPEARS THE MAIN FORCING AND MOISTURE WILL
NOT ARRIVE ACROSS THE AREA UNTIL THURSDAY EVENING. AT THIS TIME I
HAVE LEFT SOME LOW END POPS IN DURING THE AFTERNOON...BUT IF THESE
TRENDS CONTINUE...WE MAY BE ABLE TO GO DRY ALL AFTERNOON ON
THURSDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA. PERIODS
OF RAIN STILL APPEAR TO BE A GOOD BET THURSDAY NIGHT.
KJB
//PREV DISCUSSION...
310 PM CDT
SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE
WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW
AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK.
THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS
AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST
HALF OF NEXT WEEK.
REST OF TODAY AND TONIGHT...
A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE
HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD
TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO
VALLEY THROUGH EASTERN QUEBEC.
A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH
SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH
EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE
SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH
THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM
CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE
REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL
SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER
LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT
AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE
BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES
DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP
ACCUMULATIONS.
CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN
TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA.
TOMORROW AND TOMORROW NIGHT...
AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE
TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW
ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE
US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS
THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE
HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY
ADJUSTMENTS.
RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND
EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE
SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER
HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN.
WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF
THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON
WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX
TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT
70 IN THE SOUTHERN CWA.
FRIDAY AND SATURDAY...
THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY
SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND
EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS
WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE
SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT.
THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX
TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD
FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE
MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR
NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING
LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY
FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN
NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER
30S TO MID 40S.
SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY
MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW
CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR
BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER
40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN
THE OUTLYING AREAS.
GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY
NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT
LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE
FROM THE UPPER 30S TO THE MID 40S.
EXTENDED...SUNDAY THROUGH TUESDAY...
AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY
EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK
BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST
MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE
SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY
NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS
PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY.
IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER
NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON
SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE
REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE
OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF
THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED
INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS
SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH
TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS
WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING
TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL
REMAIN ABOVE FREEZING.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* CHANCE OF LIGHT RAIN LATE THIS EVENING/OVERNIGHT.
* STRONG/GUSTY SOUTH/SOUTHEAST WINDS THURSDAY.
* CHANCE OF SHRA LATE THURSDAY AFTERNOON.
* SHOWERS WITH MVFR VIS/CIGS THURSDAY EVENING.
* ISOLATED TSRA THURSDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
A LARGE AREA OF VFR LIGHT SHOWERS OVER EASTERN IA AND WESTERN IL
WILL CONTINUE TO DIMINISH AS IT MOVES EAST THIS EVENING WITH VERY
DRY LOW LEVELS AHEAD OF THIS RAIN AIDING ITS EROSION AND THIS
TREND IS HANDLED FAIRLY WELL WITH SHORT TERM/HI RES GUIDANCE.
ADDITIONAL SHOWERS THEN REDEVELOP IN THE VICINITY OF A WARM FRONT
LATE THIS EVENING AND OVERNIGHT...MAINLY OVER NORTHERN IL AND THIS
WILL BE THE BEST TIMING FOR SHOWERS AND MAY NEED A TEMPO BUT
CONFIDENCE IS TOO LOW BOTH COVERAGE AND TIMING TO INCLUDE ANYTHING
WITH THIS FORECAST. CIGS WILL REMAIN VFR LOWERING INTO THE 6-9KFT
RANGE.
EAST/NORTHEAST WINDS AROUND 10KTS WILL DIMINISH THROUGH THE
EVENING AND TURN MORE EAST/SOUTHEASTERLY TOWARD MORNING. SPEEDS
WILL GRADUALLY INCREASE TOWARD SUNRISE AS WELL BUT SHORTLY AFTER
SUNRISE THE GRADIENT WILL TIGHTEN AND COMBINED WITH LOW LEVEL
MIXING...WINDS WILL RAPIDLY INCREASE TO 20KT WITH GUSTS TO 30KT
WITH THE POTENTIAL FOR STRONGER GUSTS ACROSS NORTHWEST IL
INCLUDING RFD. WIND DIRECTION WILL REMAIN MAINLY SOUTHEASTERLY
MUCH OF THE DAY...SLOWLY TURNING MORE SOUTHERLY INTO THE
AFTERNOON. WINDS WILL BEGIN TO DIMINISH BY MID/LATE AFTERNOON...
FIRST AT RFD AND THEN SPREADING EAST ACROSS THE CHICAGO AREA
TERMINALS BY EVENING.
LOW PRESSURE RESPONSIBLE FOR THE STRONGER WINDS WILL MOVE ACROSS
THE AREA THURSDAY EVENING AND THIS APPEARS TO BE THE BEST TIME
PERIOD FOR SHOWERS. HAVE DELAYED SHOWER ARRIVAL UNTIL 20Z AT RFD
AND 01Z AT ORD. ONCE SHOWERS ARRIVE...WINDS WILL LIKELY QUICKLY
DIMINISH AND CIGS COULD QUICKLY LOWER THROUGH MVFR WITH A BRIEF
PERIOD OF IFR POSSIBLE LATE THURSDAY EVENING OR EARLY FRIDAY
MORNING BEFORE WINDS SHIFT WEST/NORTHWEST. THUNDER POTENTIAL ALSO
APPEARS TO BE TIED MORE TO THE COLD FRONT/WIND SHIFT WHICH WILL BE
LATER IN THE EVENING AND WHILE POSSIBLE...CONFIDENCE TOO LOW TO
INCLUDE IN THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM FOR LIGHT RAIN LATE THIS EVENING/OVERNIGHT.
* HIGH FOR WINDS THROUGH THE PERIOD...MEDIUM FOR TIMING CHANGES.
* MEDIUM FOR SHOWERS THURSDAY EVENING WITH ASSOCIATED CIGS/VIS.
* LOW FOR TSRA THURSDAY EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...DRY/VFR.
* SUNDAY THROUGH TUESDAY...CHANCE OF SHRA. MVFR POSSIBLE.
&&
.MARINE...
219 PM CDT
PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE
AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL
BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL
PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS
WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD
BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE
AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH
SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE
WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET
LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE
GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS
EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL
PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM THURSDAY TO 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
934 PM CDT WED APR 23 2014
.DISCUSSION...
931 PM CDT
SHOWERS CONTINUE TO MOVE/DEVELOP EASTWARD ACROSS NORTHERN ILLINOIS
EARLY THIS EVENING WITHIN A ZONE OF INCREASING ISENTROPIC ASCENT
ALONG THE WESTERN PERIPHERY OF A SURFACE RIDGE OF HIGH PRESSURE. THIS
ACTIVITY IS EXPECTED TO CONTINUE MOVING EASTWARD ACROSS NORTHERN
ILLINOIS LATE THIS EVENING...AND LIKELY ENDING PRIOR TO DAYBREAK
THURSDAY AS THE BETTER FORCING AND MOISTENING SHIFTS TO THE NORTH
AND EAST OF THE REGION. THEREFORE...NO BIG CHANGES ARE NEEDED TO THE
GOING FORECAST FOR TONIGHT.
THURSDAY IS SHAPING UP TO BE A BREEZY AND A MILDER DAY ACROSS THE
AREA AS SOUTHEASTERLY FLOW RAMPS UP IN RESPONSE TO AN AREA OF LOW
PRESSURE APPROACHING WESTERN ILLINOIS DURING THE AFTERNOON. IT
APPEARS THAT IN SPITE OF THE SOUTH-SOUTHEASTERLY WIND
COMPONENT...THAT WINDS COULD BE VERY GUSTY...UP IN THE 30 TO 35 KT
RANGE...DURING THE AFTERNOON. ALSO...IT APPEARS THAT THESE
SOUTHEASTERLY WINDS WILL TRANSPORT A DRIER LOWER LEVEL AIR MASS IN
ACROSS THE AREA DURING THE DAY...AND THIS COULD LEAD TO LOWER
SURFACE DEW POINTS THAN CURRENTLY FORECAST...ESPECIALLY ACROSS THE
EASTERN HALF OF THE AREA. WITH THIS IN MIND...I HAVE BACKED OFF ON
POPS DURING THE AFTERNOON THURSDAY...WITH A LIKELY SLOWER EVOLUTION
OF THE PRECIPITATION. IT APPEARS THE MAIN FORCING AND MOISTURE WILL
NOT ARRIVE ACROSS THE AREA UNTIL THURSDAY EVENING. AT THIS TIME I
HAVE LEFT SOME LOW END POPS IN DURING THE AFTERNOON...BUT IF THESE
TRENDS CONTINUE...WE MAY BE ABLE TO GO DRY ALL AFTERNOON ON
THURSDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA. PERIODS
OF RAIN STILL APPEAR TO BE A GOOD BET THURSDAY NIGHT.
KJB
&&
.PREV DISCUSSION...
310 PM CDT
SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE
WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW
AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK.
THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS
AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST
HALF OF NEXT WEEK.
REST OF TODAY AND TONIGHT...
A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE
HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD
TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO
VALLEY THROUGH EASTERN QUEBEC.
A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH
SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH
EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE
SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH
THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM
CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE
REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL
SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER
LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT
AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE
BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES
DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP
ACCUMULATIONS.
CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN
TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA.
TOMORROW AND TOMORROW NIGHT...
AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE
TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW
ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE
US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS
THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE
HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY
ADJUSTMENTS.
RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND
EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE
SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER
HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN.
WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF
THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON
WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX
TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT
70 IN THE SOUTHERN CWA.
FRIDAY AND SATURDAY...
THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY
SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND
EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS
WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE
SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT.
THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX
TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD
FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE
MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR
NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING
LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY
FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN
NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER
30S TO MID 40S.
SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY
MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW
CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR
BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER
40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN
THE OUTLYING AREAS.
GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY
NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT
LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE
FROM THE UPPER 30S TO THE MID 40S.
EXTENDED...SUNDAY THROUGH TUESDAY...
AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY
EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK
BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST
MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE
SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY
NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS
PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY.
IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER
NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON
SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE
REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE
OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF
THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED
INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS
SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH
TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS
WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING
TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL
REMAIN ABOVE FREEZING.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* CHANCE OF SHRA LATE THIS EVENING AND OVERNIGHT.
* STRONG/GUSTY SOUTH/SOUTHEAST WINDS THURSDAY.
* CHANCE OF SHRA LATE THURSDAY AFTERNOON.
* SHOWERS WITH MVFR VIS/CIGS THURSDAY EVENING.
* ISOLATED TSRA THURSDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
A LARGE AREA OF VFR LIGHT SHOWERS OVER EASTERN IA AND WESTERN IL
WILL CONTINUE TO DIMINISH AS IT MOVES EAST THIS EVENING WITH VERY
DRY LOW LEVELS AHEAD OF THIS RAIN AIDING ITS EROSION AND THIS
TREND IS HANDLED FAIRLY WELL WITH SHORT TERM/HI RES GUIDANCE.
ADDITIONAL SHOWERS THEN REDEVELOP IN THE VICINITY OF A WARM FRONT
LATE THIS EVENING AND OVERNIGHT...MAINLY OVER NORTHERN IL AND THIS
WILL BE THE BEST TIMING FOR SHOWERS AND MAY NEED A TEMPO BUT
CONFIDENCE IS TOO LOW BOTH COVERAGE AND TIMING TO INCLUDE ANYTHING
WITH THIS FORECAST. CIGS WILL REMAIN VFR LOWERING INTO THE 6-9KFT
RANGE.
EAST/NORTHEAST WINDS AROUND 10KTS WILL DIMINISH THROUGH THE
EVENING AND TURN MORE EAST/SOUTHEASTERLY TOWARD MORNING. SPEEDS
WILL GRADUALLY INCREASE TOWARD SUNRISE AS WELL BUT SHORTLY AFTER
SUNRISE THE GRADIENT WILL TIGHTEN AND COMBINED WITH LOW LEVEL
MIXING...WINDS WILL RAPIDLY INCREASE TO 20KT WITH GUSTS TO 30KT
WITH THE POTENTIAL FOR STRONGER GUSTS ACROSS NORTHWEST IL
INCLUDING RFD. WIND DIRECTION WILL REMAIN MAINLY SOUTHEASTERLY
MUCH OF THE DAY...SLOWLY TURNING MORE SOUTHERLY INTO THE
AFTERNOON. WINDS WILL BEGIN TO DIMINISH BY MID/LATE AFTERNOON...
FIRST AT RFD AND THEN SPREADING EAST ACROSS THE CHICAGO AREA
TERMINALS BY EVENING.
LOW PRESSURE RESPONSIBLE FOR THE STRONGER WINDS WILL MOVE ACROSS
THE AREA THURSDAY EVENING AND THIS APPEARS TO BE THE BEST TIME
PERIOD FOR SHOWERS. HAVE DELAYED SHOWER ARRIVAL UNTIL 20Z AT RFD
AND 01Z AT ORD. ONCE SHOWERS ARRIVE...WINDS WILL LIKELY QUICKLY
DIMINISH AND CIGS COULD QUICKLY LOWER THROUGH MVFR WITH A BRIEF
PERIOD OF IFR POSSIBLE LATE THURSDAY EVENING OR EARLY FRIDAY
MORNING BEFORE WINDS SHIFT WEST/NORTHWEST. THUNDER POTENTIAL ALSO
APPEARS TO BE TIED MORE TO THE COLD FRONT/WIND SHIFT WHICH WILL BE
LATER IN THE EVENING AND WHILE POSSIBLE...CONFIDENCE TOO LOW TO
INCLUDE IN THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW FOR SHOWERS LATE THIS EVENING AND OVERNIGHT.
* HIGH FOR WINDS THROUGH THE PERIOD...MEDIUM FOR TIMING CHANGES.
* MEDIUM FOR SHOWERS THURSDAY EVENING WITH ASSOCIATED CIGS/VIS.
* LOW FOR TSRA THURSDAY EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...DRY/VFR.
* SUNDAY THROUGH TUESDAY...CHANCE OF SHRA. MVFR POSSIBLE.
&&
.MARINE...
219 PM CDT
PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE
AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL
BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL
PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS
WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD
BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE
AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH
SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE
WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET
LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE
GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS
EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL
PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM THURSDAY TO 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
655 PM CDT WED APR 23 2014
.DISCUSSION...
310 PM CDT
SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE
WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW
AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK.
THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS
AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST
HALF OF NEXT WEEK.
REST OF TODAY AND TONIGHT...
A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE
HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD
TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO
VALLEY THROUGH EASTERN QUEBEC.
A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH
SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH
EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE
SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH
THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM
CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE
REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL
SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER
LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT
AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE
BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES
DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP
ACCUMULATIONS.
CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN
TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA.
TOMORROW AND TOMORROW NIGHT...
AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE
TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW
ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE
US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS
THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE
HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY
ADJUSTMENTS.
RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND
EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE
SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER
HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN.
WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF
THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON
WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX
TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT
70 IN THE SOUTHERN CWA.
FRIDAY AND SATURDAY...
THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY
SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND
EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS
WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE
SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT.
THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX
TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD
FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE
MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR
NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING
LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY
FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN
NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER
30S TO MID 40S.
SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY
MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW
CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR
BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER
40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN
THE OUTLYING AREAS.
GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY
NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT
LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE
FROM THE UPPER 30S TO THE MID 40S.
EXTENDED...SUNDAY THROUGH TUESDAY...
AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY
EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK
BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST
MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE
SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY
NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS
PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY.
IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER
NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON
SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE
REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE
OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF
THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED
INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS
SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH
TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS
WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING
TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL
REMAIN ABOVE FREEZING.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* CHANCE OF SHRA LATE THIS EVENING AND OVERNIGHT.
* STRONG/GUSTY SOUTH/SOUTHEAST WINDS THURSDAY.
* CHANCE OF SHRA LATE THURSDAY AFTERNOON.
* SHOWERS WITH MVFR VIS/CIGS THURSDAY EVENING.
* ISOLATED TSRA THURSDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
A LARGE AREA OF VFR LIGHT SHOWERS OVER EASTERN IA AND WESTERN IL
WILL CONTINUE TO DIMINISH AS IT MOVES EAST THIS EVENING WITH VERY
DRY LOW LEVELS AHEAD OF THIS RAIN AIDING ITS EROSION AND THIS
TREND IS HANDLED FAIRLY WELL WITH SHORT TERM/HI RES GUIDANCE.
ADDITIONAL SHOWERS THEN REDEVELOP IN THE VICINITY OF A WARM FRONT
LATE THIS EVENING AND OVERNIGHT...MAINLY OVER NORTHERN IL AND THIS
WILL BE THE BEST TIMING FOR SHOWERS AND MAY NEED A TEMPO BUT
CONFIDENCE IS TOO LOW BOTH COVERAGE AND TIMING TO INCLUDE ANYTHING
WITH THIS FORECAST. CIGS WILL REMAIN VFR LOWERING INTO THE 6-9KFT
RANGE.
EAST/NORTHEAST WINDS AROUND 10KTS WILL DIMINISH THROUGH THE
EVENING AND TURN MORE EAST/SOUTHEASTERLY TOWARD MORNING. SPEEDS
WILL GRADUALLY INCREASE TOWARD SUNRISE AS WELL BUT SHORTLY AFTER
SUNRISE THE GRADIENT WILL TIGHTEN AND COMBINED WITH LOW LEVEL
MIXING...WINDS WILL RAPIDLY INCREASE TO 20KT WITH GUSTS TO 30KT
WITH THE POTENTIAL FOR STRONGER GUSTS ACROSS NORTHWEST IL
INCLUDING RFD. WIND DIRECTION WILL REMAIN MAINLY SOUTHEASTERLY
MUCH OF THE DAY...SLOWLY TURNING MORE SOUTHERLY INTO THE
AFTERNOON. WINDS WILL BEGIN TO DIMINISH BY MID/LATE AFTERNOON...
FIRST AT RFD AND THEN SPREADING EAST ACROSS THE CHICAGO AREA
TERMINALS BY EVENING.
LOW PRESSURE RESPONSIBLE FOR THE STRONGER WINDS WILL MOVE ACROSS
THE AREA THURSDAY EVENING AND THIS APPEARS TO BE THE BEST TIME
PERIOD FOR SHOWERS. HAVE DELAYED SHOWER ARRIVAL UNTIL 20Z AT RFD
AND 01Z AT ORD. ONCE SHOWERS ARRIVE...WINDS WILL LIKELY QUICKLY
DIMINISH AND CIGS COULD QUICKLY LOWER THROUGH MVFR WITH A BRIEF
PERIOD OF IFR POSSIBLE LATE THURSDAY EVENING OR EARLY FRIDAY
MORNING BEFORE WINDS SHIFT WEST/NORTHWEST. THUNDER POTENTIAL ALSO
APPEARS TO BE TIED MORE TO THE COLD FRONT/WIND SHIFT WHICH WILL BE
LATER IN THE EVENING AND WHILE POSSIBLE...CONFIDENCE TOO LOW TO
INCLUDE IN THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW FOR SHOWERS LATE THIS EVENING AND OVERNIGHT.
* HIGH FOR WINDS THROUGH THE PERIOD...MEDIUM FOR TIMING CHANGES.
* MEDIUM FOR SHOWERS THURSDAY EVENING WITH ASSOCIATED CIGS/VIS.
* LOW FOR TSRA THURSDAY EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...DRY/VFR.
* SUNDAY THROUGH TUESDAY...CHANCE OF SHRA. MVFR POSSIBLE.
&&
.MARINE...
219 PM CDT
PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE
AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL
BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL
PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS
WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD
BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE
AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH
SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE
WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET
LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE
GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS
EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL
PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM THURSDAY TO 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
628 PM CDT Wed Apr 23 2014
...Updated for Aviation...
.SHORT TERM...(This evening through Thursday)
ISSUED AT 142 PM CDT WED APR 23 2014
RAP, HRRR, and NAM all suggesting dryline will be located near
Garden City and Liberal between 21Z Wednesday and 00z Thursday.
Convective initiation along this boundary however somewhat more
uncertain given the warm 700mb temperatures and cloud
cover/precipitation currently over portions of southwest Kansas.
At this time based on the ARW,NMM, and HRRR still suggests there
will be some widely scattered convection developing late day/early
this evening. Will therefore follow the general trend of the non
hydrostatic models for for late today/early tonight but keep
precipitation chances more widely scattered. Mid level instability
and shear continues to support that if storms do develop they will
be capable of becoming severe. Main hazard early tonight still
appears to be hail and strong winds given shear, mid level
instability, high cloud bases, downdraft capes, and model
soundings at 00z Thursday.
A cold front crossing northwest Kansas earlier this afternoon is
forecast to cross southwest Kansas between 00z and 09z Thursday.
Convection along this cold front is expected to develop late day
and increase in areal coverage early tonight as an upper level
trough, which was located near the four corners region as 12z
Thursday, moves east across the Central High Plains. This cold
front will provide the better opportunity for precipitation,
especially along and east of a Dighton to Liberal line based on
where the better low level moisture is forecast to be early tonight
by the NAM. Precipitation chances will begin to taper off from
northwest to southeast, mainly after midnight as this cold front
surges south.
Behind this cold front very windy conditions are expected to
develop given the pressure tendencies and 925 to 850mb winds. Wind
speeds of 30 to 35 mph will be likely for several hours behind
this front, especially west of highway 283 between 03z and 09z.
After 09z Thursday the winds will begin to decrease and are
expected to continue to decrease during the day on Thursday as a
surface high/ridge axis crosses western Kansas. NAM and GFS 850mb
mixdown temperatures and guidance was with 2-4 degrees of each
other for highs on Thursday so given this and the expected
sunshine Thursday afternoon will stay close to what they suggest.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 255 PM CDT WED APR 23 2014
Medium range models indicate weak upper level ridging transitioning
eastward across the Western High Plains Friday and into the Central
Plains Saturday. Meanwhile, a strong upper level trough of low
pressure will begin to push ashore into southern California Saturday
setting up a southwest flow across the Western High Plains by
Saturday afternoon. As a lack of significant low/mid level moisture
prevails during this time frame, dry conditions will persist through
Saturday afternoon. The potential for thunderstorms returns Saturday
evening as the upper level trough begins to lift northeast out of
the Desert Southwest into the Western High Plains. As the shortwave
approaches, a prevailing low level southeasterly flow will continue
to draw moisture northward into Kansas ahead of a sharpening dryline.
Although where the dryline sets up is uncertain this far out, the
likelihood for thunderstorm development is good ahead of it as upper
level dynamic support becomes more favorable. Severe weather is
possible late Saturday into early Sunday morning. Precip potential
shifts north and east Sunday as the upper level trough lifts
northeast across the Western High Plains increasing the potential
for dryslotting across southwest Kansas.
Temperatures will be above normal Friday as weak upper level ridging
moves eastward out of the Rockies across the Western High Plains. A
south to southeasterly flow will return to western Kansas as lee
side troughing redevelops across eastern Colorado. This will draw
warmer air north into the area with H85 temperatures ranging from
around 20C across central Kansas to near 25C in far southwest
Kansas. Look for highs well up into the 80s(F) Friday afternoon.
The warming trend continues into Saturday as enhanced warm air
advection raises H85 temperatures into the mid to upper 20s(C)
across southwest Kansas. Mid to upper 80s(F) are likely Saturday
afternoon with the lower 90s(F) possible behind a dryline across
extreme southwest Kansas. Much cooler temperatures will arrive
early next week as a cold front sweeps through western Kansas.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 623 PM CDT WED APR 23 2014
Scattered thunderstorms with small hail and winds to 40-50kt will
be mainly around the Dodge City area through 01-02Z. South winds of
25-35kt will shift to the northwest with a cold front around
03-04Z at 25-35kt. A few more thunderstorms are expected with the
cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 72 45 84 / 60 0 0 0
GCK 44 71 44 84 / 40 10 0 0
EHA 44 73 45 85 / 10 0 0 0
LBL 45 75 45 86 / 30 0 0 0
HYS 46 72 43 81 / 80 10 0 0
P28 53 75 46 85 / 60 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 8 PM CDT this evening FOR KSZ030-031-045-046-
064>066-077>081-087>090.
WIND ADVISORY until 2 AM CDT /1 AM MDT/ Thursday FOR KSZ061-062-
074-075-084-085.
WIND ADVISORY until 2 AM CDT Thursday FOR KSZ043-044-063-076-086.
RED FLAG WARNING until 8 PM CDT this evening FOR KSZ074-075-084-
085.
&&
$$
SHORT TERM...Burgert
LONG TERM...JJohnson
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS JACKSON KY
138 PM EDT TUE APR 22 2014
.UPDATE...
ISSUED AT 137 PM EDT TUE APR 22 2014
ISSUED AN UPDATE TO INPUT THE LATEST OBSERVATIONS. TEMPS HAVE WARMED
NICELY INTO THE UPPER 60S ACROSS MOST AREAS AND ADJUSTED THE HOURLY
TEMPS SLIGHTLY. AS WELL DEW POINTS ARE A BIT HIGHER THAN ANTICIPATED
AS WELL. THE SHOWER ACTIVITY IS JUST ABOUT DONE AS THE FRONT IS JUST
OFF TO THE WEST AND IS ABOUT TO PUSH THROUGH THE AREA. THE GRIDS HAVE
BEEN SENT TO NDFD.
UPDATE ISSUED AT 1056 AM EDT TUE APR 22 2014
THE FIRST BOUT OF SHOWERS HAVE PASSED THROUGH EASTERN KENTUCKY THIS
MORNING WITH SOME ISOLATED SHOWERS IN THE SOUTHERN PORTIONS. AT THIS
TIME THE COLD FRONT STILL LIES TO THE WEST AND WILL PUSH THROUGH THIS
AFTERNOON. DAYTIME HEATING...WHAT LITTLE TAKES PLACE DUE TO EXTENSIVE
CLOUD COVER...WILL ALLOW FOR SOME INSTABILITY AND HAVE KEPT SHOWERS
AND AN ISOLATED THUNDERSTORM POSSIBLE IN THE EASTERN AND SOUTHERN
ZONES FOR THE REST OF TODAY. THUNDER IS STILL A QUESTIONABLE
POSSIBILITY DUE TO THE LIMITED INSTABILITY. BECAUSE OF THIS HAVE
TAKEN PRECIP OUT OF THE NORTHWESTERN COUNTIES IN THE BLUEGRASS AND
THE NORTHERN PORTION OF THE DANIEL BOONE NATIONAL FOREST. HAVE ISSUED
A NEW ZFP AND SENT THE GRIDS TO NDFD.
UPDATE ISSUED AT 730 AM EDT TUE APR 22 2014
STILL WAITING ON THE THUNDER...IT DOES APPEAR THAT THE MAIN LINE OF
RAIN IS CROSSING EAST KENTUCKY CURRENTLY...IN LINE WITH THE LATEST
HRRR. HAVE HIGHLIGHTED THIS WITH THE HIGHEST POPS AND BEST CHANCE FOR
THUNDER FOLLOWED BY LOWER POPS INTO THE EARLY AFTERNOON. ALSO FINE
TUNED THE T AND TD GRIDS THROUGH MID MORNING BASED ON THE CURRENT OBS
AND TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 22 2014
06Z SFC ANALYSIS SHOWS A WEAK COLD FRONT APPROACHING KENTUCKY FROM A
PARENT LOW CROSSING THE EASTERN GREAT LAKES. SCATTERED LIGHT SHOWERS
ARE MOVING THROUGH EAST KENTUCKY EARLY THIS MORNING IN ADVANCE OF
THIS FRONT BENEATH HIGH AND MID LEVEL CLOUDS. SO FAR...ACTUAL
MEASUREMENT BY THE SHOWERS HAS BEEN HARD TO COME BY...BUT A FEW
PROMISING CLUSTERS ARE DEVELOPING NORTH OF INTERSTATE CORRIDOR ON
RADAR. DESPITE THE THREAT OF SHOWERS AND THE PERSISTENT CLOUD
COVER...TEMPERATURES THROUGH THE AREA HAVE BEEN ABLE TO ESTABLISH A
SMALL RIDGE TO VALLEY DIFFERENCE AS THE EASTERN VALLEYS ARE SITTING
IN THE MID 50S WHILE LOW TO MID 60S ARE FOUND ON THE RIDGES. THIS
SHOULD EVEN OUT AS THE AIR SATURATES LATER THIS NIGHT WITH A GRADUAL
UPTICK IN SHOWER COVERAGE. DEWPOINTS HAVE COME UP INTO THE LOWER 50S
FOR MOST OF THE AREA...THOUGH SOME 40S ARE FOUND ON THE RIDGES AND IN
THE FAR EAST. MEANWHILE...WINDS ARE LIGHT AND GENERALLY FROM THE
SOUTHWEST THROUGH THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL DEPICT A
DEVELOPING TROUGH SWEEPING THROUGH THE NORTHEAST OHIO VALLEY LATER
TODAY PROMPTING HEIGHT FALLS ACROSS EAST KENTUCKY. THE BEST ENERGY
WITH THIS TROUGH STAYS WELL TO THE NORTH AND EAST OF KENTUCKY...WITH
SOME WEAKER AMOUNTS PASSING THROUGH THIS MORNING. THE NORTHEAST
TROUGH DOES EXIT THE REGION LATER WEDNESDAY ALLOWING HEIGHTS TO BUILD
BACK OVER KENTUCKY AMIDST RIDGING INBOUND FROM THE SOUTHERN PLAINS.
WITH THE AGREEMENT ALOFT...HAVE FAVORED A GENERAL MODEL BLEND FOR THE
SHORT TERM PORTION OF THE FORECAST. HOWEVER...FOR WEATHER DETAILS
HAVE LEANED MORE HEAVILY ON THE HIGHER RESOLUTION HRRR AND NAM12
THROUGH 00Z WEDNESDAY.
SENSIBLE WEATHER WILL FEATURE A DAMP AND COOLER DAY AS THE FRONT
GRADUALLY MAKES ITS WAY THROUGH EAST KENTUCKY. THE BEST CHANCE FOR
SOME RAIN OF NOTE WILL BE RIGHT WITH THE BOUNDARY/S PASSAGE LATER
THIS MORNING. THE THERMAL PROFILE STILL LOOKS UNSTABLE ENOUGH TO
ALLOW FOR A THUNDERSTORM THROUGH NOON ACROSS THE AREA SO WILL KEEP
THAT IN THE FORECAST. EVEN SO...THE LACK OF ANY ORGANIZATION WILL KEEP
ANY STORMS THAT OCCUR TO A MORE GARDEN VARIETY LEVEL AND ALSO PREVENT
MUCH IN THE WAY OF SOAKING RAINS FOR ALL BUT A FEW SPOTS. DRIER AND
COOLER AIR MOVES INTO THE CWA LATER THIS AFTERNOON IN THE WAKE OF THE
FRONT ENDING THE SHOWER THREAT AND EVENTUALLY CLEARING THE CLOUDS.
THE DECENT CAA BEHIND THE BOUNDARY TONIGHT WILL COMPOUND RADIATIONAL
COOLING IN THE MORE SHELTERED VALLEYS TO SEND TEMPERATURES THERE INTO
THE MIDDLE 30S. THIS...COMBINED WITH LIGHT WINDS...WILL LEAVE THEM
VULNERABLE TO PATCHY FROST BY DAWN. HAVE ADDED THIS TO THE WX GRIDS
AND WILL CONTINUE ITS MENTION IN THE HWO. FOR WEDNESDAY...AFTER A
CHILLY START...READINGS WILL CLIMB INTO THE MID 60S MOST PLACES...
THOUGH THE ARRIVAL OF MID LEVEL CLOUDS LATE IN THE DAY WILL DO LITTLE
TO HELP TEMPS RISE IN THE AFTERNOON.
STARTED OUT WITH THE BC/CONSSHORT GUIDANCE FOR THE TEMPS...
DEWPOINTS...AND WIND GRIDS FOR THE FIRST 24 HOURS OF THE FORECAST
FOLLOWED BY THE BC/CONSALL THEREAFTER. THE DEWPOINTS WERE ADJUSTED
LOWER FOR MIDDAY AND EARLY AFTERNOON ON WEDNESDAY FOR EXTRA DRY AIR
MIXDOWN. DID MAKE SOME FINE TUNE ADJUSTMENTS TO THE CONSALL FOR LOWS
TONIGHT AND HIGHS ON WEDNESDAY. AS FOR POPS...ENDED UP SIMILAR TO THE
MOS GUIDANCE TODAY AND ALSO WITH ITS LOW SINGLE DIGIT VALUES TONIGHT
AND WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE APR 22 2014
THE MODELS WERE IN DECENT AGREEMENT IN THE EXTENDED THIS TIME
AROUND. THE MODEL CONSENSUS IS FOR LARGE TROUGH OF LOW PRESSURE TO
MOVE EASTWARD OFF THE PACIFIC OCEAN AND ACROSS THE CONUS WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT. THE MODELS DISPLAYED SOME SMALL
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM AND ITS EXACT
TIMING...BUT OVERALL AGREEMENT WAS SOLID. THE SURFACE REFLECTION OF
THE UPPER TROUGH AND ITS ASSOCIATED AREA OF LOW PRESSURE WILL BE AN
AREA OF LOW PRESSURE THAT IS FAIRLY INTENSE FOR THIS TIME OF
YEAR...ALONG WITH A TRAILING COLD FRONT. BASED ON THE LATEST MODEL
DATA...IT APPEARS THAT THE FRONT ITSELF WILL NOT BE ALL THAT
IMPRESSIVE IN AND OFF ITSELF. HOWEVER...THE BOUNDARY SHOULD BE WELL
DEFINED ENOUGH...AND HAVE ENOUGH GULF MOISTURE TO TAP INTO...TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS AS IT MOVES ACROSS THE
REGION THURSDAY NIGHT INTO EARLY FRIDAY MORNING. WITH A VIGOROUS
UPPER TROUGH STEERING IT...THE SURFACE SYSTEM SHOULD MOVE ACROSS THE
AREA FAIRLY QUICKLY. THAT BEING SAID...ADJUSTED THE FORECAST GRIDS
TO REFLECT ABOUT A 20 HOUR PERIOD OF PRECIPITATION BEGINNING LATE
THURSDAY AFTERNOON AND LASTING INTO LATE FRIDAY MORNING. THE LATEST
MODEL DATA SUGGESTS MODEST INSTABILITY AT BEST DURING FRONTAL
PASSAGE...SO THUNDER SHOULD BE FAIRLY ISOLATED. TEMPERATURES IN OUR
DEEPEST VALLEYS COULD DROP ENOUGH TO ALLOW FOR SOME FROST FORMATION
AROUND THE AREA. BASED ON HOW WARM IT HAS BEEN LATELY...AND HOW WARM
IT WILL BE LEADING INTO WEDNESDAY NIGHT...WILL CONTINUE WITH MENTION
OF PATCHY VALLEY FROST IN THE GRIDS FOR EARLY THURSDAY MORNING.
A SECOND WEATHER IS PROGGED TO AFFECT THE AREA OVER THE WEEKEND AND
INTO THE BEGINNING OF THE UPCOMING WORK WEEK. THE ISSUE WITH THIS
SYSTEM LIES IN THE AMOUNT OF UNCERTAINTY BETWEEN THE MODELS AS TO THE
TIMING AND INTENSITY OF THIS WEATHER SYSTEM. AS IT STANDS...THE GFS
MODEL IS PRODUCING STRONG AND MORE SLOWLY EVOLVING AREA OF LOW
PRESSURE THAN THE ECMWF. BASED ON THE LATEST RUN OF THE
ECMWF...EASTERN KENTUCKY COULD EXPERIENCE ISOLATED INSTANCES OF
PRECIPITATION BEGINNING AS EARLY AS SATURDAY AFTERNOON AND LASTING
THROUGH THE END OF THE PERIOD ON MONDAY. THE GFS...ON THE OTHER
HAND...HOLDS OFF ON INTRODUCING PRECIPITATION TO THE AREA UNTIL LATE
SATURDAY NIGHT. THE SOLUTION FOR THIS PORTION OF THE FORECAST WAS TO
GO WITH A BLEND OF THE TWO MODELS...GFS AND ECWMF...TO TRY AND
ACCOUNT FOR THE AMOUNT OF DIFFERENCE BETWEEN THEM. THAT BEING
SAID...THE FORECAST SOLUTION FOR LATE SATURDAY ONWARD IS OF LOW
CONFIDENCE...WITH A SLIGHT BIAS TOWARD THE NORMALLY MORE RELIABLE
ECMWF SOLUTION. THAT BEING SAID...WENT WITH A SLIGHT CHANCE OF
SHOWERS AND STORMS BEGINNING SATURDAY AFTERNOON IN ASSOCIATION WITH
A SLOW MOVING WARM FRONTAL BOUNDARY. THE REST OF THE WEEKEND AND
FIRST COUPLE OF DAYS OF THE WORK WEEK WILL FEATURE A MEANDERING
SURFACE FRONTAL BOUNDARY WITH SCATTERED SHOWERS AND STORMS FIRING
ALONG IT FROM TIME TO TIME. WITH INSTABILITY ONCE AGAIN
LIMITED...DECIDED TO GO WITH MENTION OF ISOLATED THUNDER ACROSS THE
AREA.
TEMPERATURES THROUGHOUT THE PERIOD...WITH THE POSSIBLE EXCEPTION OF
THURSDAY MORNINGS LOWS...SHOULD BE AT OR SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR. THE WARMEST DAYS WILL LIKELY BE THURSDAY THROUGH
SATURDAY...AS THE GULF OPENS UP AS WE BECOME FIRMLY ENTRENCHED IN
THE WARM SECTOR OF A PASSING CYCLONE. HIGHS IN THE LOW TO MID 70S
WILL BE COMMON ON THESE DAYS. ONCE THE SECOND AREA OF LOW PRESSURE
BEGINS TO INFLUENCE THE REGION AND THE SURFACE FRONTS STALLS OUT
ACROSS THE AREA...TEMPERATURES WILL BE QUITE A BIT A COOLER DUE TO
THE INFLUENCE OF CLOUDS AND PRECIPITATION. HIGHS FROM SUNDAY ONWARD
WILL AVERAGE MOSTLY IN THE 60S AND SHOULD HOVER AROUND NORMAL VALUES
EACH DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EDT TUE APR 22 2014
SHOWERS AND IFR CEILINGS WILL MOVE OUT OF THE AREA THIS AFTERNOON AS
SKIES WILL BEGIN TO CLEAR OUT AS THE FRONT MOVES THROUGH LEAVING VFR
CONDITIONS TONIGHT AND THROUGH THE REST OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1055 AM EDT TUE APR 22 2014
.UPDATE...
ISSUED AT 1056 AM EDT TUE APR 22 2014
THE FIRST BOUT OF SHOWERS HAVE PASSED THROUGH EASTERN KENTUCKY THIS
MORNING WITH SOME ISOLATED SHOWERS IN THE SOUTHERN PORTIONS. AT THIS
TIME THE COLD FRONT STILL LIES TO THE WEST AND WILL PUSH THROUGH THIS
AFTERNOON. DAYTIME HEATING...WHAT LITTLE TAKES PLACE DUE TO EXTENSIVE
CLOUD COVER...WILL ALLOW FOR SOME INSTABILITY AND HAVE KEPT SHOWERS
AND AN ISOLATED THUNDERSTORM POSSIBLE IN THE EASTERN AND SOUTHERN
ZONES FOR THE REST OF TODAY. THUNDER IS STILL A QUESTIONABLE
POSSIBILITY DUE TO THE LIMITED INSTABILITY. BECAUSE OF THIS HAVE
TAKEN PRECIP OUT OF THE NORTHWESTERN COUNTIES IN THE BLUEGRASS AND
THE NORTHERN PORTION OF THE DANIEL BOONE NATIONAL FOREST. HAVE ISSUED
A NEW ZFP AND SENT THE GRIDS TO NDFD.
UPDATE ISSUED AT 730 AM EDT TUE APR 22 2014
STILL WAITING ON THE THUNDER...IT DOES APPEAR THAT THE MAIN LINE OF
RAIN IS CROSSING EAST KENTUCKY CURRENTLY...IN LINE WITH THE LATEST
HRRR. HAVE HIGHLIGHTED THIS WITH THE HIGHEST POPS AND BEST CHANCE FOR
THUNDER FOLLOWED BY LOWER POPS INTO THE EARLY AFTERNOON. ALSO FINE
TUNED THE T AND TD GRIDS THROUGH MID MORNING BASED ON THE CURRENT OBS
AND TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 22 2014
06Z SFC ANALYSIS SHOWS A WEAK COLD FRONT APPROACHING KENTUCKY FROM A
PARENT LOW CROSSING THE EASTERN GREAT LAKES. SCATTERED LIGHT SHOWERS
ARE MOVING THROUGH EAST KENTUCKY EARLY THIS MORNING IN ADVANCE OF
THIS FRONT BENEATH HIGH AND MID LEVEL CLOUDS. SO FAR...ACTUAL
MEASUREMENT BY THE SHOWERS HAS BEEN HARD TO COME BY...BUT A FEW
PROMISING CLUSTERS ARE DEVELOPING NORTH OF INTERSTATE CORRIDOR ON
RADAR. DESPITE THE THREAT OF SHOWERS AND THE PERSISTENT CLOUD
COVER...TEMPERATURES THROUGH THE AREA HAVE BEEN ABLE TO ESTABLISH A
SMALL RIDGE TO VALLEY DIFFERENCE AS THE EASTERN VALLEYS ARE SITTING
IN THE MID 50S WHILE LOW TO MID 60S ARE FOUND ON THE RIDGES. THIS
SHOULD EVEN OUT AS THE AIR SATURATES LATER THIS NIGHT WITH A GRADUAL
UPTICK IN SHOWER COVERAGE. DEWPOINTS HAVE COME UP INTO THE LOWER 50S
FOR MOST OF THE AREA...THOUGH SOME 40S ARE FOUND ON THE RIDGES AND IN
THE FAR EAST. MEANWHILE...WINDS ARE LIGHT AND GENERALLY FROM THE
SOUTHWEST THROUGH THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL DEPICT A
DEVELOPING TROUGH SWEEPING THROUGH THE NORTHEAST OHIO VALLEY LATER
TODAY PROMPTING HEIGHT FALLS ACROSS EAST KENTUCKY. THE BEST ENERGY
WITH THIS TROUGH STAYS WELL TO THE NORTH AND EAST OF KENTUCKY...WITH
SOME WEAKER AMOUNTS PASSING THROUGH THIS MORNING. THE NORTHEAST
TROUGH DOES EXIT THE REGION LATER WEDNESDAY ALLOWING HEIGHTS TO BUILD
BACK OVER KENTUCKY AMIDST RIDGING INBOUND FROM THE SOUTHERN PLAINS.
WITH THE AGREEMENT ALOFT...HAVE FAVORED A GENERAL MODEL BLEND FOR THE
SHORT TERM PORTION OF THE FORECAST. HOWEVER...FOR WEATHER DETAILS
HAVE LEANED MORE HEAVILY ON THE HIGHER RESOLUTION HRRR AND NAM12
THROUGH 00Z WEDNESDAY.
SENSIBLE WEATHER WILL FEATURE A DAMP AND COOLER DAY AS THE FRONT
GRADUALLY MAKES ITS WAY THROUGH EAST KENTUCKY. THE BEST CHANCE FOR
SOME RAIN OF NOTE WILL BE RIGHT WITH THE BOUNDARY/S PASSAGE LATER
THIS MORNING. THE THERMAL PROFILE STILL LOOKS UNSTABLE ENOUGH TO
ALLOW FOR A THUNDERSTORM THROUGH NOON ACROSS THE AREA SO WILL KEEP
THAT IN THE FORECAST. EVEN SO...THE LACK OF ANY ORGANIZATION WILL KEEP
ANY STORMS THAT OCCUR TO A MORE GARDEN VARIETY LEVEL AND ALSO PREVENT
MUCH IN THE WAY OF SOAKING RAINS FOR ALL BUT A FEW SPOTS. DRIER AND
COOLER AIR MOVES INTO THE CWA LATER THIS AFTERNOON IN THE WAKE OF THE
FRONT ENDING THE SHOWER THREAT AND EVENTUALLY CLEARING THE CLOUDS.
THE DECENT CAA BEHIND THE BOUNDARY TONIGHT WILL COMPOUND RADIATIONAL
COOLING IN THE MORE SHELTERED VALLEYS TO SEND TEMPERATURES THERE INTO
THE MIDDLE 30S. THIS...COMBINED WITH LIGHT WINDS...WILL LEAVE THEM
VULNERABLE TO PATCHY FROST BY DAWN. HAVE ADDED THIS TO THE WX GRIDS
AND WILL CONTINUE ITS MENTION IN THE HWO. FOR WEDNESDAY...AFTER A
CHILLY START...READINGS WILL CLIMB INTO THE MID 60S MOST PLACES...
THOUGH THE ARRIVAL OF MID LEVEL CLOUDS LATE IN THE DAY WILL DO LITTLE
TO HELP TEMPS RISE IN THE AFTERNOON.
STARTED OUT WITH THE BC/CONSSHORT GUIDANCE FOR THE TEMPS...
DEWPOINTS...AND WIND GRIDS FOR THE FIRST 24 HOURS OF THE FORECAST
FOLLOWED BY THE BC/CONSALL THEREAFTER. THE DEWPOINTS WERE ADJUSTED
LOWER FOR MIDDAY AND EARLY AFTERNOON ON WEDNESDAY FOR EXTRA DRY AIR
MIXDOWN. DID MAKE SOME FINE TUNE ADJUSTMENTS TO THE CONSALL FOR LOWS
TONIGHT AND HIGHS ON WEDNESDAY. AS FOR POPS...ENDED UP SIMILAR TO THE
MOS GUIDANCE TODAY AND ALSO WITH ITS LOW SINGLE DIGIT VALUES TONIGHT
AND WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE APR 22 2014
THE MODELS WERE IN DECENT AGREEMENT IN THE EXTENDED THIS TIME
AROUND. THE MODEL CONSENSUS IS FOR LARGE TROUGH OF LOW PRESSURE TO
MOVE EASTWARD OFF THE PACIFIC OCEAN AND ACROSS THE CONUS WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT. THE MODELS DISPLAYED SOME SMALL
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM AND ITS EXACT
TIMING...BUT OVERALL AGREEMENT WAS SOLID. THE SURFACE REFLECTION OF
THE UPPER TROUGH AND ITS ASSOCIATED AREA OF LOW PRESSURE WILL BE AN
AREA OF LOW PRESSURE THAT IS FAIRLY INTENSE FOR THIS TIME OF
YEAR...ALONG WITH A TRAILING COLD FRONT. BASED ON THE LATEST MODEL
DATA...IT APPEARS THAT THE FRONT ITSELF WILL NOT BE ALL THAT
IMPRESSIVE IN AND OFF ITSELF. HOWEVER...THE BOUNDARY SHOULD BE WELL
DEFINED ENOUGH...AND HAVE ENOUGH GULF MOISTURE TO TAP INTO...TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS AS IT MOVES ACROSS THE
REGION THURSDAY NIGHT INTO EARLY FRIDAY MORNING. WITH A VIGOROUS
UPPER TROUGH STEERING IT...THE SURFACE SYSTEM SHOULD MOVE ACROSS THE
AREA FAIRLY QUICKLY. THAT BEING SAID...ADJUSTED THE FORECAST GRIDS
TO REFLECT ABOUT A 20 HOUR PERIOD OF PRECIPITATION BEGINNING LATE
THURSDAY AFTERNOON AND LASTING INTO LATE FRIDAY MORNING. THE LATEST
MODEL DATA SUGGESTS MODEST INSTABILITY AT BEST DURING FRONTAL
PASSAGE...SO THUNDER SHOULD BE FAIRLY ISOLATED. TEMPERATURES IN OUR
DEEPEST VALLEYS COULD DROP ENOUGH TO ALLOW FOR SOME FROST FORMATION
AROUND THE AREA. BASED ON HOW WARM IT HAS BEEN LATELY...AND HOW WARM
IT WILL BE LEADING INTO WEDNESDAY NIGHT...WILL CONTINUE WITH MENTION
OF PATCHY VALLEY FROST IN THE GRIDS FOR EARLY THURSDAY MORNING.
A SECOND WEATHER IS PROGGED TO AFFECT THE AREA OVER THE WEEKEND AND
INTO THE BEGINNING OF THE UPCOMING WORK WEEK. THE ISSUE WITH THIS
SYSTEM LIES IN THE AMOUNT OF UNCERTAINTY BETWEEN THE MODELS AS TO THE
TIMING AND INTENSITY OF THIS WEATHER SYSTEM. AS IT STANDS...THE GFS
MODEL IS PRODUCING STRONG AND MORE SLOWLY EVOLVING AREA OF LOW
PRESSURE THAN THE ECMWF. BASED ON THE LATEST RUN OF THE
ECMWF...EASTERN KENTUCKY COULD EXPERIENCE ISOLATED INSTANCES OF
PRECIPITATION BEGINNING AS EARLY AS SATURDAY AFTERNOON AND LASTING
THROUGH THE END OF THE PERIOD ON MONDAY. THE GFS...ON THE OTHER
HAND...HOLDS OFF ON INTRODUCING PRECIPITATION TO THE AREA UNTIL LATE
SATURDAY NIGHT. THE SOLUTION FOR THIS PORTION OF THE FORECAST WAS TO
GO WITH A BLEND OF THE TWO MODELS...GFS AND ECWMF...TO TRY AND
ACCOUNT FOR THE AMOUNT OF DIFFERENCE BETWEEN THEM. THAT BEING
SAID...THE FORECAST SOLUTION FOR LATE SATURDAY ONWARD IS OF LOW
CONFIDENCE...WITH A SLIGHT BIAS TOWARD THE NORMALLY MORE RELIABLE
ECMWF SOLUTION. THAT BEING SAID...WENT WITH A SLIGHT CHANCE OF
SHOWERS AND STORMS BEGINNING SATURDAY AFTERNOON IN ASSOCIATION WITH
A SLOW MOVING WARM FRONTAL BOUNDARY. THE REST OF THE WEEKEND AND
FIRST COUPLE OF DAYS OF THE WORK WEEK WILL FEATURE A MEANDERING
SURFACE FRONTAL BOUNDARY WITH SCATTERED SHOWERS AND STORMS FIRING
ALONG IT FROM TIME TO TIME. WITH INSTABILITY ONCE AGAIN
LIMITED...DECIDED TO GO WITH MENTION OF ISOLATED THUNDER ACROSS THE
AREA.
TEMPERATURES THROUGHOUT THE PERIOD...WITH THE POSSIBLE EXCEPTION OF
THURSDAY MORNINGS LOWS...SHOULD BE AT OR SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR. THE WARMEST DAYS WILL LIKELY BE THURSDAY THROUGH
SATURDAY...AS THE GULF OPENS UP AS WE BECOME FIRMLY ENTRENCHED IN
THE WARM SECTOR OF A PASSING CYCLONE. HIGHS IN THE LOW TO MID 70S
WILL BE COMMON ON THESE DAYS. ONCE THE SECOND AREA OF LOW PRESSURE
BEGINS TO INFLUENCE THE REGION AND THE SURFACE FRONTS STALLS OUT
ACROSS THE AREA...TEMPERATURES WILL BE QUITE A BIT A COOLER DUE TO
THE INFLUENCE OF CLOUDS AND PRECIPITATION. HIGHS FROM SUNDAY ONWARD
WILL AVERAGE MOSTLY IN THE 60S AND SHOULD HOVER AROUND NORMAL VALUES
EACH DAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 745 AM EDT TUE APR 22 2014
VFR CONDITIONS WILL SPLIT TIME WITH SOME MVFR CIGS AND VIS OVER THE
NEXT FEW HOURS AS THE MAIN LINE OF SHOWERS MOVES THROUGH. HAVE YANKED
THE THUNDER CHANCES AS THE SHOWERS ARE NOT SHOWING MUCH SIGNS OF
BEING TOO ROBUST...SO FAR. TO COVER LINGERING SHOWERS THROUGH THE
FIRST PART OF THE AFTERNOON AND WHEN THE ACTUAL COLD FRONT GOES
THROUGH HAVE INCLUDED A VCSH MENTION IN THE TAFS. DRY AIR WILL THEN
FILTER IN LATER THIS AFTERNOON...WITH ISOLATED SHOWERS COMING TO AN
END AND CIGS RISING TO VFR AGAIN BEFORE DISSIPATING. WEST TO
NORTHWEST WINDS WILL PICK UP AT 10 TO 15 KTS FROM THE WEST THIS
MORNING...BECOMING MORE NORTH WITH TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
745 AM EDT TUE APR 22 2014
.UPDATE...
ISSUED AT 730 AM EDT TUE APR 22 2014
STILL WAITING ON THE THUNDER...IT DOES APPEAR THAT THE MAIN LINE OF
RAIN IS CROSSING EAST KENTUCKY CURRENTLY...IN LINE WITH THE LATEST
HRRR. HAVE HIGHLIGHTED THIS WITH THE HIGHEST POPS AND BEST CHANCE FOR
THUNDER FOLLOWED BY LOWER POPS INTO THE EARLY AFTERNOON. ALSO FINE
TUNED THE T AND TD GRIDS THROUGH MID MORNING BASED ON THE CURRENT OBS
AND TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 22 2014
06Z SFC ANALYSIS SHOWS A WEAK COLD FRONT APPROACHING KENTUCKY FROM A
PARENT LOW CROSSING THE EASTERN GREAT LAKES. SCATTERED LIGHT SHOWERS
ARE MOVING THROUGH EAST KENTUCKY EARLY THIS MORNING IN ADVANCE OF
THIS FRONT BENEATH HIGH AND MID LEVEL CLOUDS. SO FAR...ACTUAL
MEASUREMENT BY THE SHOWERS HAS BEEN HARD TO COME BY...BUT A FEW
PROMISING CLUSTERS ARE DEVELOPING NORTH OF INTERSTATE CORRIDOR ON
RADAR. DESPITE THE THREAT OF SHOWERS AND THE PERSISTENT CLOUD
COVER...TEMPERATURES THROUGH THE AREA HAVE BEEN ABLE TO ESTABLISH A
SMALL RIDGE TO VALLEY DIFFERENCE AS THE EASTERN VALLEYS ARE SITTING
IN THE MID 50S WHILE LOW TO MID 60S ARE FOUND ON THE RIDGES. THIS
SHOULD EVEN OUT AS THE AIR SATURATES LATER THIS NIGHT WITH A GRADUAL
UPTICK IN SHOWER COVERAGE. DEWPOINTS HAVE COME UP INTO THE LOWER 50S
FOR MOST OF THE AREA...THOUGH SOME 40S ARE FOUND ON THE RIDGES AND IN
THE FAR EAST. MEANWHILE...WINDS ARE LIGHT AND GENERALLY FROM THE
SOUTHWEST THROUGH THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL DEPICT A
DEVELOPING TROUGH SWEEPING THROUGH THE NORTHEAST OHIO VALLEY LATER
TODAY PROMPTING HEIGHT FALLS ACROSS EAST KENTUCKY. THE BEST ENERGY
WITH THIS TROUGH STAYS WELL TO THE NORTH AND EAST OF KENTUCKY...WITH
SOME WEAKER AMOUNTS PASSING THROUGH THIS MORNING. THE NORTHEAST
TROUGH DOES EXIT THE REGION LATER WEDNESDAY ALLOWING HEIGHTS TO BUILD
BACK OVER KENTUCKY AMIDST RIDGING INBOUND FROM THE SOUTHERN PLAINS.
WITH THE AGREEMENT ALOFT...HAVE FAVORED A GENERAL MODEL BLEND FOR THE
SHORT TERM PORTION OF THE FORECAST. HOWEVER...FOR WEATHER DETAILS
HAVE LEANED MORE HEAVILY ON THE HIGHER RESOLUTION HRRR AND NAM12
THROUGH 00Z WEDNESDAY.
SENSIBLE WEATHER WILL FEATURE A DAMP AND COOLER DAY AS THE FRONT
GRADUALLY MAKES ITS WAY THROUGH EAST KENTUCKY. THE BEST CHANCE FOR
SOME RAIN OF NOTE WILL BE RIGHT WITH THE BOUNDARY/S PASSAGE LATER
THIS MORNING. THE THERMAL PROFILE STILL LOOKS UNSTABLE ENOUGH TO
ALLOW FOR A THUNDERSTORM THROUGH NOON ACROSS THE AREA SO WILL KEEP
THAT IN THE FORECAST. EVEN SO...THE LACK OF ANY ORGANIZATION WILL KEEP
ANY STORMS THAT OCCUR TO A MORE GARDEN VARIETY LEVEL AND ALSO PREVENT
MUCH IN THE WAY OF SOAKING RAINS FOR ALL BUT A FEW SPOTS. DRIER AND
COOLER AIR MOVES INTO THE CWA LATER THIS AFTERNOON IN THE WAKE OF THE
FRONT ENDING THE SHOWER THREAT AND EVENTUALLY CLEARING THE CLOUDS.
THE DECENT CAA BEHIND THE BOUNDARY TONIGHT WILL COMPOUND RADIATIONAL
COOLING IN THE MORE SHELTERED VALLEYS TO SEND TEMPERATURES THERE INTO
THE MIDDLE 30S. THIS...COMBINED WITH LIGHT WINDS...WILL LEAVE THEM
VULNERABLE TO PATCHY FROST BY DAWN. HAVE ADDED THIS TO THE WX GRIDS
AND WILL CONTINUE ITS MENTION IN THE HWO. FOR WEDNESDAY...AFTER A
CHILLY START...READINGS WILL CLIMB INTO THE MID 60S MOST PLACES...
THOUGH THE ARRIVAL OF MID LEVEL CLOUDS LATE IN THE DAY WILL DO LITTLE
TO HELP TEMPS RISE IN THE AFTERNOON.
STARTED OUT WITH THE BC/CONSSHORT GUIDANCE FOR THE TEMPS...
DEWPOINTS...AND WIND GRIDS FOR THE FIRST 24 HOURS OF THE FORECAST
FOLLOWED BY THE BC/CONSALL THEREAFTER. THE DEWPOINTS WERE ADJUSTED
LOWER FOR MIDDAY AND EARLY AFTERNOON ON WEDNESDAY FOR EXTRA DRY AIR
MIXDOWN. DID MAKE SOME FINE TUNE ADJUSTMENTS TO THE CONSALL FOR LOWS
TONIGHT AND HIGHS ON WEDNESDAY. AS FOR POPS...ENDED UP SIMILAR TO THE
MOS GUIDANCE TODAY AND ALSO WITH ITS LOW SINGLE DIGIT VALUES TONIGHT
AND WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE APR 22 2014
THE MODELS WERE IN DECENT AGREEMENT IN THE EXTENDED THIS TIME
AROUND. THE MODEL CONSENSUS IS FOR LARGE TROUGH OF LOW PRESSURE TO
MOVE EASTWARD OFF THE PACIFIC OCEAN AND ACROSS THE CONUS WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT. THE MODELS DISPLAYED SOME SMALL
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM AND ITS EXACT
TIMING...BUT OVERALL AGREEMENT WAS SOLID. THE SURFACE REFLECTION OF
THE UPPER TROUGH AND ITS ASSOCIATED AREA OF LOW PRESSURE WILL BE AN
AREA OF LOW PRESSURE THAT IS FAIRLY INTENSE FOR THIS TIME OF
YEAR...ALONG WITH A TRAILING COLD FRONT. BASED ON THE LATEST MODEL
DATA...IT APPEARS THAT THE FRONT ITSELF WILL NOT BE ALL THAT
IMPRESSIVE IN AND OFF ITSELF. HOWEVER...THE BOUNDARY SHOULD BE WELL
DEFINED ENOUGH...AND HAVE ENOUGH GULF MOISTURE TO TAP INTO...TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS AS IT MOVES ACROSS THE
REGION THURSDAY NIGHT INTO EARLY FRIDAY MORNING. WITH A VIGOROUS
UPPER TROUGH STEERING IT...THE SURFACE SYSTEM SHOULD MOVE ACROSS THE
AREA FAIRLY QUICKLY. THAT BEING SAID...ADJUSTED THE FORECAST GRIDS
TO REFLECT ABOUT A 20 HOUR PERIOD OF PRECIPITATION BEGINNING LATE
THURSDAY AFTERNOON AND LASTING INTO LATE FRIDAY MORNING. THE LATEST
MODEL DATA SUGGESTS MODEST INSTABILITY AT BEST DURING FRONTAL
PASSAGE...SO THUNDER SHOULD BE FAIRLY ISOLATED. TEMPERATURES IN OUR
DEEPEST VALLEYS COULD DROP ENOUGH TO ALLOW FOR SOME FROST FORMATION
AROUND THE AREA. BASED ON HOW WARM IT HAS BEEN LATELY...AND HOW WARM
IT WILL BE LEADING INTO WEDNESDAY NIGHT...WILL CONTINUE WITH MENTION
OF PATCHY VALLEY FROST IN THE GRIDS FOR EARLY THURSDAY MORNING.
A SECOND WEATHER IS PROGGED TO AFFECT THE AREA OVER THE WEEKEND AND
INTO THE BEGINNING OF THE UPCOMING WORK WEEK. THE ISSUE WITH THIS
SYSTEM LIES IN THE AMOUNT OF UNCERTAINTY BETWEEN THE MODELS AS TO THE
TIMING AND INTENSITY OF THIS WEATHER SYSTEM. AS IT STANDS...THE GFS
MODEL IS PRODUCING STRONG AND MORE SLOWLY EVOLVING AREA OF LOW
PRESSURE THAN THE ECMWF. BASED ON THE LATEST RUN OF THE
ECMWF...EASTERN KENTUCKY COULD EXPERIENCE ISOLATED INSTANCES OF
PRECIPITATION BEGINNING AS EARLY AS SATURDAY AFTERNOON AND LASTING
THROUGH THE END OF THE PERIOD ON MONDAY. THE GFS...ON THE OTHER
HAND...HOLDS OFF ON INTRODUCING PRECIPITATION TO THE AREA UNTIL LATE
SATURDAY NIGHT. THE SOLUTION FOR THIS PORTION OF THE FORECAST WAS TO
GO WITH A BLEND OF THE TWO MODELS...GFS AND ECWMF...TO TRY AND
ACCOUNT FOR THE AMOUNT OF DIFFERENCE BETWEEN THEM. THAT BEING
SAID...THE FORECAST SOLUTION FOR LATE SATURDAY ONWARD IS OF LOW
CONFIDENCE...WITH A SLIGHT BIAS TOWARD THE NORMALLY MORE RELIABLE
ECMWF SOLUTION. THAT BEING SAID...WENT WITH A SLIGHT CHANCE OF
SHOWERS AND STORMS BEGINNING SATURDAY AFTERNOON IN ASSOCIATION WITH
A SLOW MOVING WARM FRONTAL BOUNDARY. THE REST OF THE WEEKEND AND
FIRST COUPLE OF DAYS OF THE WORK WEEK WILL FEATURE A MEANDERING
SURFACE FRONTAL BOUNDARY WITH SCATTERED SHOWERS AND STORMS FIRING
ALONG IT FROM TIME TO TIME. WITH INSTABILITY ONCE AGAIN
LIMITED...DECIDED TO GO WITH MENTION OF ISOLATED THUNDER ACROSS THE
AREA.
TEMPERATURES THROUGHOUT THE PERIOD...WITH THE POSSIBLE EXCEPTION OF
THURSDAY MORNINGS LOWS...SHOULD BE AT OR SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR. THE WARMEST DAYS WILL LIKELY BE THURSDAY THROUGH
SATURDAY...AS THE GULF OPENS UP AS WE BECOME FIRMLY ENTRENCHED IN
THE WARM SECTOR OF A PASSING CYCLONE. HIGHS IN THE LOW TO MID 70S
WILL BE COMMON ON THESE DAYS. ONCE THE SECOND AREA OF LOW PRESSURE
BEGINS TO INFLUENCE THE REGION AND THE SURFACE FRONTS STALLS OUT
ACROSS THE AREA...TEMPERATURES WILL BE QUITE A BIT A COOLER DUE TO
THE INFLUENCE OF CLOUDS AND PRECIPITATION. HIGHS FROM SUNDAY ONWARD
WILL AVERAGE MOSTLY IN THE 60S AND SHOULD HOVER AROUND NORMAL VALUES
EACH DAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 745 AM EDT TUE APR 22 2014
VFR CONDITIONS WILL SPLIT TIME WITH SOME MVFR CIGS AND VIS OVER THE
NEXT FEW HOURS AS THE MAIN LINE OF SHOWERS MOVES THROUGH. HAVE YANKED
THE THUNDER CHANCES AS THE SHOWERS ARE NOT SHOWING MUCH SIGNS OF
BEING TOO ROBUST...SO FAR. TO COVER LINGERING SHOWERS THROUGH THE
FIRST PART OF THE AFTERNOON AND WHEN THE ACTUAL COLD FRONT GOES
THROUGH HAVE INCLUDED A VCSH MENTION IN THE TAFS. DRY AIR WILL THEN
FILTER IN LATER THIS AFTERNOON...WITH ISOLATED SHOWERS COMING TO AN
END AND CIGS RISING TO VFR AGAIN BEFORE DISSIPATING. WEST TO
NORTHWEST WINDS WILL PICK UP AT 10 TO 15 KTS FROM THE WEST THIS
MORNING...BECOMING MORE NORTH WITH TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT TUE APR 22 2014
06Z SFC ANALYSIS SHOWS A WEAK COLD FRONT APPROACHING KENTUCKY FROM A
PARENT LOW CROSSING THE EASTERN GREAT LAKES. SCATTERED LIGHT SHOWERS
ARE MOVING THROUGH EAST KENTUCKY EARLY THIS MORNING IN ADVANCE OF
THIS FRONT BENEATH HIGH AND MID LEVEL CLOUDS. SO FAR...ACTUAL
MEASUREMENT BY THE SHOWERS HAS BEEN HARD TO COME BY...BUT A FEW
PROMISING CLUSTERS ARE DEVELOPING NORTH OF INTERSTATE CORRIDOR ON
RADAR. DESPITE THE THREAT OF SHOWERS AND THE PERSISTENT CLOUD
COVER...TEMPERATURES THROUGH THE AREA HAVE BEEN ABLE TO ESTABLISH A
SMALL RIDGE TO VALLEY DIFFERENCE AS THE EASTERN VALLEYS ARE SITTING
IN THE MID 50S WHILE LOW TO MID 60S ARE FOUND ON THE RIDGES. THIS
SHOULD EVEN OUT AS THE AIR SATURATES LATER THIS NIGHT WITH A GRADUAL
UPTICK IN SHOWER COVERAGE. DEWPOINTS HAVE COME UP INTO THE LOWER 50S
FOR MOST OF THE AREA...THOUGH SOME 40S ARE FOUND ON THE RIDGES AND IN
THE FAR EAST. MEANWHILE...WINDS ARE LIGHT AND GENERALLY FROM THE
SOUTHWEST THROUGH THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL DEPICT A
DEVELOPING TROUGH SWEEPING THROUGH THE NORTHEAST OHIO VALLEY LATER
TODAY PROMPTING HEIGHT FALLS ACROSS EAST KENTUCKY. THE BEST ENERGY
WITH THIS TROUGH STAYS WELL TO THE NORTH AND EAST OF KENTUCKY...WITH
SOME WEAKER AMOUNTS PASSING THROUGH THIS MORNING. THE NORTHEAST
TROUGH DOES EXIT THE REGION LATER WEDNESDAY ALLOWING HEIGHTS TO BUILD
BACK OVER KENTUCKY AMIDST RIDGING INBOUND FROM THE SOUTHERN PLAINS.
WITH THE AGREEMENT ALOFT...HAVE FAVORED A GENERAL MODEL BLEND FOR THE
SHORT TERM PORTION OF THE FORECAST. HOWEVER...FOR WEATHER DETAILS
HAVE LEANED MORE HEAVILY ON THE HIGHER RESOLUTION HRRR AND NAM12
THROUGH 00Z WEDNESDAY.
SENSIBLE WEATHER WILL FEATURE A DAMP AND COOLER DAY AS THE FRONT
GRADUALLY MAKES ITS WAY THROUGH EAST KENTUCKY. THE BEST CHANCE FOR
SOME RAIN OF NOTE WILL BE RIGHT WITH THE BOUNDARY/S PASSAGE LATER
THIS MORNING. THE THERMAL PROFILE STILL LOOKS UNSTABLE ENOUGH TO
ALLOW FOR A THUNDERSTORM THROUGH NOON ACROSS THE AREA SO WILL KEEP
THAT IN THE FORECAST. EVEN SO...THE LACK OF ANY ORGANIZATION WILL KEEP
ANY STORMS THAT OCCUR TO A MORE GARDEN VARIETY LEVEL AND ALSO PREVENT
MUCH IN THE WAY OF SOAKING RAINS FOR ALL BUT A FEW SPOTS. DRIER AND
COOLER AIR MOVES INTO THE CWA LATER THIS AFTERNOON IN THE WAKE OF THE
FRONT ENDING THE SHOWER THREAT AND EVENTUALLY CLEARING THE CLOUDS.
THE DECENT CAA BEHIND THE BOUNDARY TONIGHT WILL COMPOUND RADIATIONAL
COOLING IN THE MORE SHELTERED VALLEYS TO SEND TEMPERATURES THERE INTO
THE MIDDLE 30S. THIS...COMBINED WITH LIGHT WINDS...WILL LEAVE THEM
VULNERABLE TO PATCHY FROST BY DAWN. HAVE ADDED THIS TO THE WX GRIDS
AND WILL CONTINUE ITS MENTION IN THE HWO. FOR WEDNESDAY...AFTER A
CHILLY START...READINGS WILL CLIMB INTO THE MID 60S MOST PLACES...
THOUGH THE ARRIVAL OF MID LEVEL CLOUDS LATE IN THE DAY WILL DO LITTLE
TO HELP TEMPS RISE IN THE AFTERNOON.
STARTED OUT WITH THE BC/CONSSHORT GUIDANCE FOR THE TEMPS...
DEWPOINTS...AND WIND GRIDS FOR THE FIRST 24 HOURS OF THE FORECAST
FOLLOWED BY THE BC/CONSALL THEREAFTER. THE DEWPOINTS WERE ADJUSTED
LOWER FOR MIDDAY AND EARLY AFTERNOON ON WEDNESDAY FOR EXTRA DRY AIR
MIXDOWN. DID MAKE SOME FINE TUNE ADJUSTMENTS TO THE CONSALL FOR LOWS
TONIGHT AND HIGHS ON WEDNESDAY. AS FOR POPS...ENDED UP SIMILAR TO THE
MOS GUIDANCE TODAY AND ALSO WITH ITS LOW SINGLE DIGIT VALUES TONIGHT
AND WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE APR 22 2014
THE MODELS WERE IN DECENT AGREEMENT IN THE EXTENDED THIS TIME
AROUND. THE MODEL CONSENSUS IS FOR LARGE TROUGH OF LOW PRESSURE TO
MOVE EASTWARD OFF THE PACIFIC OCEAN AND ACROSS THE CONUS WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT. THE MODELS DISPLAYED SOME SMALL
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM AND ITS EXACT
TIMING...BUT OVERALL AGREEMENT WAS SOLID. THE SURFACE REFLECTION OF
THE UPPER TROUGH AND ITS ASSOCIATED AREA OF LOW PRESSURE WILL BE AN
AREA OF LOW PRESSURE THAT IS FAIRLY INTENSE FOR THIS TIME OF
YEAR...ALONG WITH A TRAILING COLD FRONT. BASED ON THE LATEST MODEL
DATA...IT APPEARS THAT THE FRONT ITSELF WILL NOT BE ALL THAT
IMPRESSIVE IN AND OFF ITSELF. HOWEVER...THE BOUNDARY SHOULD BE WELL
DEFINED ENOUGH...AND HAVE ENOUGH GULF MOISTURE TO TAP INTO...TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS AS IT MOVES ACROSS THE
REGION THURSDAY NIGHT INTO EARLY FRIDAY MORNING. WITH A VIGOROUS
UPPER TROUGH STEERING IT...THE SURFACE SYSTEM SHOULD MOVE ACROSS THE
AREA FAIRLY QUICKLY. THAT BEING SAID...ADJUSTED THE FORECAST GRIDS
TO REFLECT ABOUT A 20 HOUR PERIOD OF PRECIPITATION BEGINNING LATE
THURSDAY AFTERNOON AND LASTING INTO LATE FRIDAY MORNING. THE LATEST
MODEL DATA SUGGESTS MODEST INSTABILITY AT BEST DURING FRONTAL
PASSAGE...SO THUNDER SHOULD BE FAIRLY ISOLATED. TEMPERATURES IN OUR
DEEPEST VALLEYS COULD DROP ENOUGH TO ALLOW FOR SOME FROST FORMATION
AROUND THE AREA. BASED ON HOW WARM IT HAS BEEN LATELY...AND HOW WARM
IT WILL BE LEADING INTO WEDNESDAY NIGHT...WILL CONTINUE WITH MENTION
OF PATCHY VALLEY FROST IN THE GRIDS FOR EARLY THURSDAY MORNING.
A SECOND WEATHER IS PROGGED TO AFFECT THE AREA OVER THE WEEKEND AND
INTO THE BEGINNING OF THE UPCOMING WORK WEEK. THE ISSUE WITH THIS
SYSTEM LIES IN THE AMOUNT OF UNCERTAINTY BETWEEN THE MODELS AS TO THE
TIMING AND INTENSITY OF THIS WEATHER SYSTEM. AS IT STANDS...THE GFS
MODEL IS PRODUCING STRONG AND MORE SLOWLY EVOLVING AREA OF LOW
PRESSURE THAN THE ECMWF. BASED ON THE LATEST RUN OF THE
ECMWF...EASTERN KENTUCKY COULD EXPERIENCE ISOLATED INSTANCES OF
PRECIPITATION BEGINNING AS EARLY AS SATURDAY AFTERNOON AND LASTING
THROUGH THE END OF THE PERIOD ON MONDAY. THE GFS...ON THE OTHER
HAND...HOLDS OFF ON INTRODUCING PRECIPITATION TO THE AREA UNTIL LATE
SATURDAY NIGHT. THE SOLUTION FOR THIS PORTION OF THE FORECAST WAS TO
GO WITH A BLEND OF THE TWO MODELS...GFS AND ECWMF...TO TRY AND
ACCOUNT FOR THE AMOUNT OF DIFFERENCE BETWEEN THEM. THAT BEING
SAID...THE FORECAST SOLUTION FOR LATE SATURDAY ONWARD IS OF LOW
CONFIDENCE...WITH A SLIGHT BIAS TOWARD THE NORMALLY MORE RELIABLE
ECMWF SOLUTION. THAT BEING SAID...WENT WITH A SLIGHT CHANCE OF
SHOWERS AND STORMS BEGINNING SATURDAY AFTERNOON IN ASSOCIATION WITH
A SLOW MOVING WARM FRONTAL BOUNDARY. THE REST OF THE WEEKEND AND
FIRST COUPLE OF DAYS OF THE WORK WEEK WILL FEATURE A MEANDERING
SURFACE FRONTAL BOUNDARY WITH SCATTERED SHOWERS AND STORMS FIRING
ALONG IT FROM TIME TO TIME. WITH INSTABILITY ONCE AGAIN
LIMITED...DECIDED TO GO WITH MENTION OF ISOLATED THUNDER ACROSS THE
AREA.
TEMPERATURES THROUGHOUT THE PERIOD...WITH THE POSSIBLE EXCEPTION OF
THURSDAY MORNINGS LOWS...SHOULD BE AT OR SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR. THE WARMEST DAYS WILL LIKELY BE THURSDAY THROUGH
SATURDAY...AS THE GULF OPENS UP AS WE BECOME FIRMLY ENTRENCHED IN
THE WARM SECTOR OF A PASSING CYCLONE. HIGHS IN THE LOW TO MID 70S
WILL BE COMMON ON THESE DAYS. ONCE THE SECOND AREA OF LOW PRESSURE
BEGINS TO INFLUENCE THE REGION AND THE SURFACE FRONTS STALLS OUT
ACROSS THE AREA...TEMPERATURES WILL BE QUITE A BIT A COOLER DUE TO
THE INFLUENCE OF CLOUDS AND PRECIPITATION. HIGHS FROM SUNDAY ONWARD
WILL AVERAGE MOSTLY IN THE 60S AND SHOULD HOVER AROUND NORMAL VALUES
EACH DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 145 AM EDT TUE APR 22 2014
EXPECT VFR CONDITIONS TO GRADUALLY GIVE WAY TO SOME MVFR CIGS AND VIS
TOWARDS DAWN AS A COLD FRONT MOVES ON THROUGH THE AREA. REDUCED
VISIBILITY AND LOWER CEILINGS...DOWN TO IFR...WILL BE POSSIBLE FOR
MUCH OF TUESDAY MORNING AS THE BOUNDARY PASSES...ALONG WITH A
POSSIBLE THUNDERSTORM. DRY AIR WILL THEN FILTER IN LATER TUESDAY
AFTERNOON...WITH SHOWERS COMING TO AN END AND CIGS RISING TO VFR
AGAIN BEFORE DISSIPATING. WINDS WILL BE LIGHT FROM THE SOUTHWEST
UNTIL RIGHT WITH THE FRONT...AROUND DAWN...WHEN THEY WILL PICK UP AT
10 TO 15 KTS FROM THE WEST...BECOMING NORTHWEST WITH TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
726 PM EDT WED APR 23 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 503 PM EDT WED APR 23 2014
WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE
THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH
THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES.
SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS
FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE
OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY
EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW
CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS
IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER.
TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET
THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE
THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE
WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY
INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF
IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW
ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT
18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT
THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING
OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO
SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH...
REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z
RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF
WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE
IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z
MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS
INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE
CWA...INCLUDING THE KEWEENAW PENINSULA.
DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY
AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR
CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET
STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO
NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO
H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH
290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE
INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH
MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG
ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY
TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA
PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF
MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT
COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR
THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP
HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING
RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE
TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING
AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME
PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND
GEM-NH.
PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND
MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE
CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE
NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE
SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW.
FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR
HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL
TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY
SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE
MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE
INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW
INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY
EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT
IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL
SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF
ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS
WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR.
EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED
6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8
TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z
MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE
GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN
ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS
EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY
MORNING.
IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS
FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING
MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY
OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER
STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND
DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED.
SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING
INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST.
SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY
EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85
THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE
FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE
BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON
SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH
KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS
HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF
THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES
BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS
WEEKEND.
REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY
AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN
THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY
OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP
CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT
WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY
MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE
FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE
ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX
TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE
FORECAST ELEMENTS INCLUDING POPS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 725 PM EDT WED APR 23 2014
DRY AIRMASS REMAINS IN PLACE OVER THE REGION BUT THE INCREASING HIGH
CLOUDS PORTENDS THE CHANGE IN CONDITIONS EXPECTED LATER IN THE
FORECAST. VFR CONDITIONS TO PREVAIL THROUGH THE NIGHT AND INTO THE
EARLY DAYLIGHT HOURS BUT CLOUD COVER WILL CONTINUE TO THICKEN AND
CIGS LOWER WITH APPROACHING SYSTEM. HOW QUICKLY THE DRIER AIR WILL
ERODE BEFORE PCPN CAN START AND CIGS FALL BELOW VFR THE QUESTION AT
THIS TIME. CURRENTLY EXPECT PCPN TO ARRIVE AT KIWD AT 12Z WITH CIGS
FALLING TO MVFR SHORTLY THEREAFTER. LIGHT RAIN WILL GIVE WAY TO A
MIX OF RAIN AND SNOW AS CIGS SLOWLY LOWER THROUGH THE LATE
MORNING...WITH SNOW EXPECTED IN THE AFTERNOON. KCMX WILL SEE MIXED
PCPN AND CIGS DROPPING INTO MVFR RANGE BY 20Z. AT KSAW...CIGS STAY
VFR UNTIL EARLY AFTERNOON AS DRIER AIR PERSISTS THERE A BIT
LONGER...BUT THEN THEY TOO WILL SEE CIGS DROP INTO MVFR RANGE WITH
THE DEVELOPMENT OF LIGHT RAIN/SNOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 PM EDT WED APR 23 2014
LOW PRESSURE MOVES INTO THE REGION THURSDAY NIGHT INTO FRIDAY. LOW
IS TRENDING STRONGER...SO EAST WINDS MAY REACH 30 KTS THURSDAY NIGHT
THEN SHIFT TO THE NORTH-NORTHWEST UP TO 30 KTS BY FRIDAY AFTN AFTER
THE LOW MOVES TO THE EAST OF LK SUPERIOR. POSSIBLE THAT SOME GALE
GUSTS TO 35 KTS MAY OCCUR LATE FRIDAY AFTN INTO FRIDAY EVENING.
WINDS DIMINISH BLO 20 KTS FOR THE WEEKEND AS HIGH PRESSURE SETTLES
ACROSS ONTARIO AND THE GREAT LAKES. NEXT CHANCE OF STRONGER EAST
WINDS WOULD BE ON MONDAY AS THE HIGH SLOWLY MOVES EAST AND LOW
PRESSURE DEVELOPS OVER THE PLAINS.
&&
.HYDROLOGY...
ISSUED AT 503 PM EDT WED APR 23 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO
FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL
RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN
RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME
INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR
CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD
STAGE IN THE SHORT TERM.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
AFTERNOON FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 PM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EDT TUE APR 22 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A
SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR
TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS
PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND
LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER
CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS
BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY
DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE
CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN.
FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE
REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER
THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED
TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER
MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR
KIWD.
CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY
THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS
MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND
W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN
AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A
CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC
HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL
SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER
IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT
OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL
EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS...
BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR
23 IS 17F. MIGHT BE CLOSE TO THAT.
ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO
INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST
DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR
DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE
BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY
30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING
POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM
NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST
SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER.
WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS
FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED
ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 PM EDT TUE APR 22 2014
THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION LATE WEDNESDAY NIGHT AND LIKELY CONTINUING INTO
FRIDAY EVENING. THE UPPER TROUGH MOVING OVER THE WESTERN COAST OF
THE PACIFIC NORTHWEST WILL BE THE FEATURE TO INFLUENCE THE AREA FOR
THE END OF THIS WEEK. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. HIGH PRESSURE THAT WILL BE OVER THE AREA TONIGHT AND
WEDNESDAY WILL BE SLOWLY DEPARTING THE AREA WEDNESDAY NIGHT.
THIS...COMBINED WITH A SLIGHTLY LATER ARRIVAL FROM THE UPPER
TROUGH...WILL DELAY THE START OF THE PRECIPITATION LATER THAN
EXPECTED 24 HOURS AGO AND GENERALLY MOVING IN DURING THE DAY ON
THURSDAY. THERE ARE SEVERAL WAVES ASSOCIATED WITH THIS UPPER
TROUGH...WHICH LEADS TO A DOUBLE BARREL LOW MOVING OUT OF THE
NORTHERN/CENTRAL PLAINS ON WEDNESDAY NIGHT. WHILE PREVIOUS MODELS
RUNS HAD THE IDEA OF THESE LOWS MERGING WHEN THE NORTHERN/SOUTHERN
WAVES IN THE UPPER TROUGH COMING TOGETHER AND STRENGTHENING AS IT
MOVES THROUGH NORTHERN LAKE MICHIGAN. BUT MOST OF THE 12Z MODEL
RUNS (EXCEPT FOR THE GFS) HAS TRENDED TOWARDS THE LACK OF PHASING
BETWEEN THOSE UPPER LEVEL WAVES. WITHOUT THIS PHASING...THE
SOUTHERN STREAM WAVE WOULD SHIFT EAST THROUGH THE CENTRAL
MISSISSIPPI VALLEY THURSDAY NIGHT AND JUST HAVE A BROAD LOW MOVING
THROUGH THE AREA. WHILE THIS STILL BRING PRECIPITATION TO THE
AREA...IT MAY HAVE SOME AFFECT ON THE AMOUNTS OVER PORTIONS OF THE
AREA BEFORE THE NORTHERN STREAM WAVE ARRIVES THURSDAY NIGHT OVER
THE UPPER GREAT LAKES. THE GREATEST AFFECT OF THIS SPLIT FEATURE IS
FOR THE PRECIPITATION TO STEADILY SHIFT NORTHEAST AND GENERALLY OUT
OF THE AREA FOR FRIDAY. IF THIS IS THE CASE...FLOW ALOFT WILL BE
MORE WESTERLY ON FRIDAY...LEADING TO WARMER TEMPERATURES AND
DRIER CONDITIONS THAN INITIALLY EXPECTED.
ALTHOUGH THERE ARE STILL DIFFERENCES IN THE MODELS WITH THE EXACT
HANDLING OF THE PHASING...IT STILL APPEARS THE MOST OF THE CWA WILL
SEE 0.5 INCH OF QPF. THE HEAVIEST PRECIPITATION STILL APPEARS TO
OCCUR OVER THE WESTERN HALF TO 2/3RDS OF THE U.P. AND EXPECT SOME
LOCATIONS OVER THE WEST TO BE NEARING 1 INCH OF LIQUID EQUIVALENT.
THE IMPACT FROM THIS EVENT AND THE ASSOCIATED 0.75-1.0 INCH OF QPF
OVER THE WESTERN HALF OF THE CWA WILL DEPEND ON THE PRECIP TYPE
FORECAST. ALTHOUGH THIS FORECAST HAS BEEN AND CONTINUES TO BE
TRICKY...TRENDS IN THE MODELS ARE POINTING TOWARDS SNOW OVER AT
LEAST THE NORTHWEST HALF OF UPPER MICHIGAN WITH THE WARMER AIR
REMAINING HUNG UP TO THE SOUTH-SOUTHEAST OF THE AREA. IN
ADDITION...WITH THE DRY AIR FROM THE HIGH TAKING LONGER TO
DEPART...THE LOW LEVEL DRY AIR WILL AID EVAPORATIVE COOLING IN THE
LOW LEVELS AS THE PRECIPITATION STARTS. THIS WOULD LEAD TO ABOVE
FREEZING LAYERS ABOVE THE SURFACE TO COOL TO OR BELOW FREEZING AND
HAVE A FEELING THE PRECIP TYPE WILL BE LARGELY SNOW INITIALLY OVER
THE WEST (ESPECIALLY HIGHER TERRAIN). THE 12Z MODEL THERMAL
FIELDS ARE STILL BORDERLINE FOR PRECIP TYPE HEADING THROUGH
THURSDAY...BUT LOOKING AT SOUNDINGS THERE IS A NEARLY ISOTHERMAL
LAYER BELOW 750MB AROUND OR BELOW FREEZING. THUS...HAVE TRENDED THE
FORECAST TOWARDS A MORE SNOW THAN RAIN OVER THE NORTHWEST HALF.
AT THIS TIME...THAT BEST OPPORTUNITY FOR A RAIN/SNOW MIX OR MORE
RAIN WOULD BE ALONG THE WISCONSIN BORDER AND ALSO SOUTHEAST OF A
LINE FROM IRON MOUNTAIN TO GWINN TO SENEY.
ALTHOUGH THERE ARE SOME INDICATIONS IN THE COBB OUTPUT OF HIGHER
SNOW RATIOS...WOULD EXPECT VALUES TO BE GENERALLY IN THE 8-10 TO 1
RANGE DUE TO THE AMOUNT OF FORCING BELOW THE DGZ. SINCE THE SNOW
WILL START DURING THE DAY THURSDAY...IT IS DIFFICULT TO GET
SIGNIFICANT ACCUMULATIONS TO OCCUR BEFORE DAYTIME HEATING IS LOST
(ESPECIALLY ON ROADWAYS) AND HAVE LIMITED AMOUNTS DURING THE DAY TO
A SLUSHY COUPLE INCHES OVER PORTIONS OF THE WEST. WITH THE COOLING
AT NIGHT...SHOULD SEE ACCUMULATIONS INCREASE ON BOTH ROADS AND
SNOW/GRASS COVERED SURFACES. AT THAT TIME...THE BEST QPF AND COLD
AIR WILL BE OVER LAKE SUPERIOR AND AFFECTING THE KEWEENAW PENINSULA.
HAVE THE HIGHEST AMOUNTS FORECASTED FOR THE KEWEENAW...WITH 6-9
INCHES BY 12Z FRIDAY. SOUTH AND EAST OF THERE ARE MORE UP IN THE AIR
WITH THE RAIN POTENTIAL AND SLIGHTLY WARMER SURFACE
TEMPERATURES...BUT STILL FEEL THERE COULD BE 2-6 INCHES OF SLUSHY
ACCUMULATION. LOOKING AT THE 00Z ECMWF ENSEMBLE SNOWFALL...MORE THAN
50 PERCENT OF THE MEMBERS HAVE 24HR SNOWFALL AMOUNTS OF EXCEEDING 3
INCHES OVER THE NORTHWEST 2/3RDS OF THE CWA AND PROBS DECREASE TO
20-30 PERCENT OF 6 INCHES.
WITH LOW CONFIDENCE ON WARNING AMOUNTS AT THIS POINT (AND THE
IMPACTS ARE LARGELY IN THE 5TH PERIOD)...DIDN/T FEEL COMFORTABLE
WITH ISSUING A WATCH AT THIS PERIOD. THEREFORE...HAVE ISSUED AN SPS
FOR PORTIONS OF WESTERN UPPER MICHIGAN AND WILL ALLOW THE SHIFT
TONIGHT TO SEE IF THE TRENDS FROM THE 12Z RUNS CONTINUE.
BEHIND THE SYSTEM...MODELS ARE FAIRLY CONSISTENT ON A STRONG
CANADIAN HIGH DEVELOPING IN THE PRAIRIES AND SHIFTING EAST TO
HUDSON BAY EARLY NEXT WEEK. THAT WILL LEAD TO DRY
NORTH-NORTHEASTERLY FLOW OVER THE AREA INTO THE FIRST HALF OF NEXT
WEEK. THAT FLOW REGIME SHOULD KEEP TEMPERATURES BELOW NORMAL
(POTENTIALLY NEARING RECORD LOW HIGH TEMPS AT OUR OFFICE) AND ANY
PRECIP ASSOCIATED WITH THE UPPER TROUGH MOVING THROUGH THE
CENTRAL/SOUTHERN PLAINS SOUTH OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 648 PM EDT TUE APR 22 2014
GUSTY N WINDS TO 20KT AT KSAW WILL DIMINISH SHORTLY AFT 00Z AS HIGH
PRES CONTINUES TO BUILD FROM THE WEST AND THE PRES GRADIENT WEAKENS.
DRY AIR MASS WILL THEN DOMINATE TONIGHT THRU WED... RESULTING IN
LIGHT WINDS/VFR CONDITIONS AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT TUE APR 22 2014
AS HIGH PRES RIDGE EXTENDING FROM MN SOUTHWARD SHIFTS TO WRN LAKE
SUPERIOR/WRN UPPER MI TONIGHT...WINDS WILL CONTINUE TO DIMINISH FROM W
TO E. WINDS ARE ALREADY LIGHT OVER THE WRN LAKE...AND THE INITIAL NW
20-30KT WINDS OVER ERN LAKE SUPERIOR WILL DROP TO UNDER 15KT
TONIGHT. LIGHT WINDS WILL LINGER THRU WED AS HIGH PRES RIDGE SLOWLY
DRIFTS E. HOWEVER...E WINDS WILL BEGIN TO INCREASE TOWARD 20KT OVER
FAR WRN LAKE SUPERIOR IN THE AFTN. EASTERLY WINDS WILL THEN
GRADUALLY INCREASE WED NIGHT AND WILL REACH 20-30KT ACROSS MUCH OF
LAKE SUPERIOR THU IN ADVANCE OF LOW PRES APPROACHING THE WRN GREAT
LAKES. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LOW...NOT
OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING/COASTAL CONVERGENCE
WOULD ENHANCE THIS E WIND. AS THE LOW SHIFTS TO THE E LATER ON FRI
INTO SAT AHEAD OF HIGH PRES BUILDING INTO SCENTRAL CANADA...THE WIND
WILL SHIFT TO THE N AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF
THE HIGH ON SAT. BEST CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD
BE OVER THE E HALF OF THE LAKE...AGAIN...DEPENDING ON INTENSITY OF
THE LOW.
&&
.HYDROLOGY...
ISSUED AT 458 PM EDT TUE APR 22 2014
A MUCH COLDER DAY SEEN ACROSS UPPER MICHIGAN TODAY WHEN
COMPARED TO YESTERDAY. THIS HAS LED TO REDUCED SNOWMELT WHICH
WILL CONTINUE INTO WEDNESDAY...ALTHOUGH SOME RIVER LEVELS WILL
LIKELY STILL BE ON THE RISE AS WATER WORKS THROUGH THE RIVER
SYSTEMS. ALTHOUGH RATHER COOL TEMPERATURES WILL REMAIN...UNSETTLED
WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT...POTENTIALLY ADDING
TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT
PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND
SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID
WILL BE POSSIBLE BY FRIDAY MORNING. THERE IS SOME UNCERTAINTY ON
HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE
BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL
CONTINUE TO REFINE THE FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE
BEEN ALSTON/ALSM4/ AND CHASSELL/CLLM4/ ON THE STURGEON
RIVER AND CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER. SINCE SNOW
MELT THE NEXT FEW DAYS WILL BE DIMINISHING...EXPECT THE RIVERS TO
SLOWLY SUBSIDE AND NOT EXCEED FLOOD STAGE. OTHERWISE...WIDESPREAD
FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 PM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EDT TUE APR 22 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A
SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR
TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS
PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND
LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER
CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS
BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY
DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE
CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN.
FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE
REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER
THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED
TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER
MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR
KIWD.
CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY
THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS
MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND
W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN
AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A
CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC
HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL
SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER
IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT
OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL
EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS...
BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR
23 IS 17F. MIGHT BE CLOSE TO THAT.
ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO
INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST
DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR
DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE
BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY
30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING
POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM
NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST
SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER.
WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS
FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED
ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 PM EDT TUE APR 22 2014
THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION LATE WEDNESDAY NIGHT AND LIKELY CONTINUING INTO
FRIDAY EVENING. THE UPPER TROUGH MOVING OVER THE WESTERN COAST OF
THE PACIFIC NORTHWEST WILL BE THE FEATURE TO INFLUENCE THE AREA FOR
THE END OF THIS WEEK. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. HIGH PRESSURE THAT WILL BE OVER THE AREA TONIGHT AND
WEDNESDAY WILL BE SLOWLY DEPARTING THE AREA WEDNESDAY NIGHT.
THIS...COMBINED WITH A SLIGHTLY LATER ARRIVAL FROM THE UPPER
TROUGH...WILL DELAY THE START OF THE PRECIPITATION LATER THAN
EXPECTED 24 HOURS AGO AND GENERALLY MOVING IN DURING THE DAY ON
THURSDAY. THERE ARE SEVERAL WAVES ASSOCIATED WITH THIS UPPER
TROUGH...WHICH LEADS TO A DOUBLE BARREL LOW MOVING OUT OF THE
NORTHERN/CENTRAL PLAINS ON WEDNESDAY NIGHT. WHILE PREVIOUS MODELS
RUNS HAD THE IDEA OF THESE LOWS MERGING WHEN THE NORTHERN/SOUTHERN
WAVES IN THE UPPER TROUGH COMING TOGETHER AND STRENGTHENING AS IT
MOVES THROUGH NORTHERN LAKE MICHIGAN. BUT MOST OF THE 12Z MODEL
RUNS (EXCEPT FOR THE GFS) HAS TRENDED TOWARDS THE LACK OF PHASING
BETWEEN THOSE UPPER LEVEL WAVES. WITHOUT THIS PHASING...THE
SOUTHERN STREAM WAVE WOULD SHIFT EAST THROUGH THE CENTRAL
MISSISSIPPI VALLEY THURSDAY NIGHT AND JUST HAVE A BROAD LOW MOVING
THROUGH THE AREA. WHILE THIS STILL BRING PRECIPITATION TO THE
AREA...IT MAY HAVE SOME AFFECT ON THE AMOUNTS OVER PORTIONS OF THE
AREA BEFORE THE NORTHERN STREAM WAVE ARRIVES THURSDAY NIGHT OVER
THE UPPER GREAT LAKES. THE GREATEST AFFECT OF THIS SPLIT FEATURE IS
FOR THE PRECIPITATION TO STEADILY SHIFT NORTHEAST AND GENERALLY OUT
OF THE AREA FOR FRIDAY. IF THIS IS THE CASE...FLOW ALOFT WILL BE
MORE WESTERLY ON FRIDAY...LEADING TO WARMER TEMPERATURES AND
DRIER CONDITIONS THAN INITIALLY EXPECTED.
ALTHOUGH THERE ARE STILL DIFFERENCES IN THE MODELS WITH THE EXACT
HANDLING OF THE PHASING...IT STILL APPEARS THE MOST OF THE CWA WILL
SEE 0.5 INCH OF QPF. THE HEAVIEST PRECIPITATION STILL APPEARS TO
OCCUR OVER THE WESTERN HALF TO 2/3RDS OF THE U.P. AND EXPECT SOME
LOCATIONS OVER THE WEST TO BE NEARING 1 INCH OF LIQUID EQUIVALENT.
THE IMPACT FROM THIS EVENT AND THE ASSOCIATED 0.75-1.0 INCH OF QPF
OVER THE WESTERN HALF OF THE CWA WILL DEPEND ON THE PRECIP TYPE
FORECAST. ALTHOUGH THIS FORECAST HAS BEEN AND CONTINUES TO BE
TRICKY...TRENDS IN THE MODELS ARE POINTING TOWARDS SNOW OVER AT
LEAST THE NORTHWEST HALF OF UPPER MICHIGAN WITH THE WARMER AIR
REMAINING HUNG UP TO THE SOUTH-SOUTHEAST OF THE AREA. IN
ADDITION...WITH THE DRY AIR FROM THE HIGH TAKING LONGER TO
DEPART...THE LOW LEVEL DRY AIR WILL AID EVAPORATIVE COOLING IN THE
LOW LEVELS AS THE PRECIPITATION STARTS. THIS WOULD LEAD TO ABOVE
FREEZING LAYERS ABOVE THE SURFACE TO COOL TO OR BELOW FREEZING AND
HAVE A FEELING THE PRECIP TYPE WILL BE LARGELY SNOW INITIALLY OVER
THE WEST (ESPECIALLY HIGHER TERRAIN). THE 12Z MODEL THERMAL
FIELDS ARE STILL BORDERLINE FOR PRECIP TYPE HEADING THROUGH
THURSDAY...BUT LOOKING AT SOUNDINGS THERE IS A NEARLY ISOTHERMAL
LAYER BELOW 750MB AROUND OR BELOW FREEZING. THUS...HAVE TRENDED THE
FORECAST TOWARDS A MORE SNOW THAN RAIN OVER THE NORTHWEST HALF.
AT THIS TIME...THAT BEST OPPORTUNITY FOR A RAIN/SNOW MIX OR MORE
RAIN WOULD BE ALONG THE WISCONSIN BORDER AND ALSO SOUTHEAST OF A
LINE FROM IRON MOUNTAIN TO GWINN TO SENEY.
ALTHOUGH THERE ARE SOME INDICATIONS IN THE COBB OUTPUT OF HIGHER
SNOW RATIOS...WOULD EXPECT VALUES TO BE GENERALLY IN THE 8-10 TO 1
RANGE DUE TO THE AMOUNT OF FORCING BELOW THE DGZ. SINCE THE SNOW
WILL START DURING THE DAY THURSDAY...IT IS DIFFICULT TO GET
SIGNIFICANT ACCUMULATIONS TO OCCUR BEFORE DAYTIME HEATING IS LOST
(ESPECIALLY ON ROADWAYS) AND HAVE LIMITED AMOUNTS DURING THE DAY TO
A SLUSHY COUPLE INCHES OVER PORTIONS OF THE WEST. WITH THE COOLING
AT NIGHT...SHOULD SEE ACCUMULATIONS INCREASE ON BOTH ROADS AND
SNOW/GRASS COVERED SURFACES. AT THAT TIME...THE BEST QPF AND COLD
AIR WILL BE OVER LAKE SUPERIOR AND AFFECTING THE KEWEENAW PENINSULA.
HAVE THE HIGHEST AMOUNTS FORECASTED FOR THE KEWEENAW...WITH 6-9
INCHES BY 12Z FRIDAY. SOUTH AND EAST OF THERE ARE MORE UP IN THE AIR
WITH THE RAIN POTENTIAL AND SLIGHTLY WARMER SURFACE
TEMPERATURES...BUT STILL FEEL THERE COULD BE 2-6 INCHES OF SLUSHY
ACCUMULATION. LOOKING AT THE 00Z ECMWF ENSEMBLE SNOWFALL...MORE THAN
50 PERCENT OF THE MEMBERS HAVE 24HR SNOWFALL AMOUNTS OF EXCEEDING 3
INCHES OVER THE NORTHWEST 2/3RDS OF THE CWA AND PROBS DECREASE TO
20-30 PERCENT OF 6 INCHES.
WITH LOW CONFIDENCE ON WARNING AMOUNTS AT THIS POINT (AND THE
IMPACTS ARE LARGELY IN THE 5TH PERIOD)...DIDN/T FEEL COMFORTABLE
WITH ISSUING A WATCH AT THIS PERIOD. THEREFORE...HAVE ISSUED AN SPS
FOR PORTIONS OF WESTERN UPPER MICHIGAN AND WILL ALLOW THE SHIFT
TONIGHT TO SEE IF THE TRENDS FROM THE 12Z RUNS CONTINUE.
BEHIND THE SYSTEM...MODELS ARE FAIRLY CONSISTENT ON A STRONG
CANADIAN HIGH DEVELOPING IN THE PRAIRIES AND SHIFTING EAST TO
HUDSON BAY EARLY NEXT WEEK. THAT WILL LEAD TO DRY
NORTH-NORTHEASTERLY FLOW OVER THE AREA INTO THE FIRST HALF OF NEXT
WEEK. THAT FLOW REGIME SHOULD KEEP TEMPERATURES BELOW NORMAL
(POTENTIALLY NEARING RECORD LOW HIGH TEMPS AT OUR OFFICE) AND ANY
PRECIP ASSOCIATED WITH THE UPPER TROUGH MOVING THROUGH THE
CENTRAL/SOUTHERN PLAINS SOUTH OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EDT TUE APR 22 2014
GUSTY NW WINDS TO 20-25KT AT KCMX/KSAW WILL DIMINISH...ESPECIALLY
LATE AFTN...WITH THE SLOW APPROACH OF HIGH PRES FROM THE PLAINS AND
A WEAKENING PRES GRADIENT. WITH DRIER AIR ARRIVING FROM THE N AND W
ALONG WITH DAYTIME MIXING...EXPECT MVFR CIGS AT KSAW/KCMX TO LIFT
ABOVE 3KFT OR TO SCATTER OUT LATER THIS AFTN. KIWD HAS ALREADY
TRENDED VFR. SCATTERED FLURRIES/SPRINKLES WILL ALSO END IN THE NEXT
FEW HRS. DRY AIR MASS WILL THEN DOMINATE TONIGHT THRU WED...
RESULTING IN LIGHT WINDS/VFR CONDITIONS AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT TUE APR 22 2014
AS HIGH PRES RIDGE EXTENDING FROM MN SOUTHWARD SHIFTS TO WRN LAKE
SUPERIOR/WRN UPPER MI TONIGHT...WINDS WILL CONTINUE TO DIMINISH FROM W
TO E. WINDS ARE ALREADY LIGHT OVER THE WRN LAKE...AND THE INITIAL NW
20-30KT WINDS OVER ERN LAKE SUPERIOR WILL DROP TO UNDER 15KT
TONIGHT. LIGHT WINDS WILL LINGER THRU WED AS HIGH PRES RIDGE SLOWLY
DRIFTS E. HOWEVER...E WINDS WILL BEGIN TO INCREASE TOWARD 20KT OVER
FAR WRN LAKE SUPERIOR IN THE AFTN. EASTERLY WINDS WILL THEN
GRADUALLY INCREASE WED NIGHT AND WILL REACH 20-30KT ACROSS MUCH OF
LAKE SUPERIOR THU IN ADVANCE OF LOW PRES APPROACHING THE WRN GREAT
LAKES. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LOW...NOT
OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING/COASTAL CONVERGENCE
WOULD ENHANCE THIS E WIND. AS THE LOW SHIFTS TO THE E LATER ON FRI
INTO SAT AHEAD OF HIGH PRES BUILDING INTO SCENTRAL CANADA...THE WIND
WILL SHIFT TO THE N AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF
THE HIGH ON SAT. BEST CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD
BE OVER THE E HALF OF THE LAKE...AGAIN...DEPENDING ON INTENSITY OF
THE LOW.
&&
.HYDROLOGY...
ISSUED AT 458 PM EDT TUE APR 22 2014
A MUCH COLDER DAY SEEN ACROSS UPPER MICHIGAN TODAY WHEN
COMPARED TO YESTERDAY. THIS HAS LED TO REDUCED SNOWMELT WHICH
WILL CONTINUE INTO WEDNESDAY...ALTHOUGH SOME RIVER LEVELS WILL
LIKELY STILL BE ON THE RISE AS WATER WORKS THROUGH THE RIVER
SYSTEMS. ALTHOUGH RATHER COOL TEMPERATURES WILL REMAIN...UNSETTLED
WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT...POTENTIALLY ADDING
TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT
PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND
SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID
WILL BE POSSIBLE BY FRIDAY MORNING. THERE IS SOME UNCERTAINTY ON
HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE
BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL
CONTINUE TO REFINE THE FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE
BEEN ALSTON/ALSM4/ AND CHASSELL/CLLM4/ ON THE STURGEON
RIVER AND CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER. SINCE SNOW
MELT THE NEXT FEW DAYS WILL BE DIMINISHING...EXPECT THE RIVERS TO
SLOWLY SUBSIDE AND NOT EXCEED FLOOD STAGE. OTHERWISE...WIDESPREAD
FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 PM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EDT TUE APR 22 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A
SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR
TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS
PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND
LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER
CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS
BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY
DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE
CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN.
FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE
REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER
THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED
TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER
MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR
KIWD.
CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY
THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS
MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND
W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN
AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A
CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC
HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL
SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER
IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT
OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL
EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS...
BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR
23 IS 17F. MIGHT BE CLOSE TO THAT.
ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO
INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST
DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR
DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE
BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY
30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING
POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM
NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST
SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER.
WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS
FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED
ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 PM EDT TUE APR 22 2014
THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION LATE WEDNESDAY NIGHT AND LIKELY CONTINUING INTO
FRIDAY EVENING. THE UPPER TROUGH MOVING OVER THE WESTERN COAST OF
THE PACIFIC NORTHWEST WILL BE THE FEATURE TO INFLUENCE THE AREA FOR
THE END OF THIS WEEK. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. HIGH PRESSURE THAT WILL BE OVER THE AREA TONIGHT AND
WEDNESDAY WILL BE SLOWLY DEPARTING THE AREA WEDNESDAY NIGHT.
THIS...COMBINED WITH A SLIGHTLY LATER ARRIVAL FROM THE UPPER
TROUGH...WILL DELAY THE START OF THE PRECIPITATION LATER THAN
EXPECTED 24 HOURS AGO AND GENERALLY MOVING IN DURING THE DAY ON
THURSDAY. THERE ARE SEVERAL WAVES ASSOCIATED WITH THIS UPPER
TROUGH...WHICH LEADS TO A DOUBLE BARREL LOW MOVING OUT OF THE
NORTHERN/CENTRAL PLAINS ON WEDNESDAY NIGHT. WHILE PREVIOUS MODELS
RUNS HAD THE IDEA OF THESE LOWS MERGING WHEN THE NORTHERN/SOUTHERN
WAVES IN THE UPPER TROUGH COMING TOGETHER AND STRENGTHENING AS IT
MOVES THROUGH NORTHERN LAKE MICHIGAN. BUT MOST OF THE 12Z MODEL
RUNS (EXCEPT FOR THE GFS) HAS TRENDED TOWARDS THE LACK OF PHASING
BETWEEN THOSE UPPER LEVEL WAVES. WITHOUT THIS PHASING...THE
SOUTHERN STREAM WAVE WOULD SHIFT EAST THROUGH THE CENTRAL
MISSISSIPPI VALLEY THURSDAY NIGHT AND JUST HAVE A BROAD LOW MOVING
THROUGH THE AREA. WHILE THIS STILL BRING PRECIPITATION TO THE
AREA...IT MAY HAVE SOME AFFECT ON THE AMOUNTS OVER PORTIONS OF THE
AREA BEFORE THE NORTHERN STREAM WAVE ARRIVES THURSDAY NIGHT OVER
THE UPPER GREAT LAKES. THE GREATEST AFFECT OF THIS SPLIT FEATURE IS
FOR THE PRECIPITATION TO STEADILY SHIFT NORTHEAST AND GENERALLY OUT
OF THE AREA FOR FRIDAY. IF THIS IS THE CASE...FLOW ALOFT WILL BE
MORE WESTERLY ON FRIDAY...LEADING TO WARMER TEMPERATURES AND
DRIER CONDITIONS THAN INITIALLY EXPECTED.
ALTHOUGH THERE ARE STILL DIFFERENCES IN THE MODELS WITH THE EXACT
HANDLING OF THE PHASING...IT STILL APPEARS THE MOST OF THE CWA WILL
SEE 0.5 INCH OF QPF. THE HEAVIEST PRECIPITATION STILL APPEARS TO
OCCUR OVER THE WESTERN HALF TO 2/3RDS OF THE U.P. AND EXPECT SOME
LOCATIONS OVER THE WEST TO BE NEARING 1 INCH OF LIQUID EQUIVALENT.
THE IMPACT FROM THIS EVENT AND THE ASSOCIATED 0.75-1.0 INCH OF QPF
OVER THE WESTERN HALF OF THE CWA WILL DEPEND ON THE PRECIP TYPE
FORECAST. ALTHOUGH THIS FORECAST HAS BEEN AND CONTINUES TO BE
TRICKY...TRENDS IN THE MODELS ARE POINTING TOWARDS SNOW OVER AT
LEAST THE NORTHWEST HALF OF UPPER MICHIGAN WITH THE WARMER AIR
REMAINING HUNG UP TO THE SOUTH-SOUTHEAST OF THE AREA. IN
ADDITION...WITH THE DRY AIR FROM THE HIGH TAKING LONGER TO
DEPART...THE LOW LEVEL DRY AIR WILL AID EVAPORATIVE COOLING IN THE
LOW LEVELS AS THE PRECIPITATION STARTS. THIS WOULD LEAD TO ABOVE
FREEZING LAYERS ABOVE THE SURFACE TO COOL TO OR BELOW FREEZING AND
HAVE A FEELING THE PRECIP TYPE WILL BE LARGELY SNOW INITIALLY OVER
THE WEST (ESPECIALLY HIGHER TERRAIN). THE 12Z MODEL THERMAL
FIELDS ARE STILL BORDERLINE FOR PRECIP TYPE HEADING THROUGH
THURSDAY...BUT LOOKING AT SOUNDINGS THERE IS A NEARLY ISOTHERMAL
LAYER BELOW 750MB AROUND OR BELOW FREEZING. THUS...HAVE TRENDED THE
FORECAST TOWARDS A MORE SNOW THAN RAIN OVER THE NORTHWEST HALF.
AT THIS TIME...THAT BEST OPPORTUNITY FOR A RAIN/SNOW MIX OR MORE
RAIN WOULD BE ALONG THE WISCONSIN BORDER AND ALSO SOUTHEAST OF A
LINE FROM IRON MOUNTAIN TO GWINN TO SENEY.
ALTHOUGH THERE ARE SOME INDICATIONS IN THE COBB OUTPUT OF HIGHER
SNOW RATIOS...WOULD EXPECT VALUES TO BE GENERALLY IN THE 8-10 TO 1
RANGE DUE TO THE AMOUNT OF FORCING BELOW THE DGZ. SINCE THE SNOW
WILL START DURING THE DAY THURSDAY...IT IS DIFFICULT TO GET
SIGNIFICANT ACCUMULATIONS TO OCCUR BEFORE DAYTIME HEATING IS LOST
(ESPECIALLY ON ROADWAYS) AND HAVE LIMITED AMOUNTS DURING THE DAY TO
A SLUSHY COUPLE INCHES OVER PORTIONS OF THE WEST. WITH THE COOLING
AT NIGHT...SHOULD SEE ACCUMULATIONS INCREASE ON BOTH ROADS AND
SNOW/GRASS COVERED SURFACES. AT THAT TIME...THE BEST QPF AND COLD
AIR WILL BE OVER LAKE SUPERIOR AND AFFECTING THE KEWEENAW PENINSULA.
HAVE THE HIGHEST AMOUNTS FORECASTED FOR THE KEWEENAW...WITH 6-9
INCHES BY 12Z FRIDAY. SOUTH AND EAST OF THERE ARE MORE UP IN THE AIR
WITH THE RAIN POTENTIAL AND SLIGHTLY WARMER SURFACE
TEMPERATURES...BUT STILL FEEL THERE COULD BE 2-6 INCHES OF SLUSHY
ACCUMULATION. LOOKING AT THE 00Z ECMWF ENSEMBLE SNOWFALL...MORE THAN
50 PERCENT OF THE MEMBERS HAVE 24HR SNOWFALL AMOUNTS OF EXCEEDING 3
INCHES OVER THE NORTHWEST 2/3RDS OF THE CWA AND PROBS DECREASE TO
20-30 PERCENT OF 6 INCHES.
WITH LOW CONFIDENCE ON WARNING AMOUNTS AT THIS POINT (AND THE
IMPACTS ARE LARGELY IN THE 5TH PERIOD)...DIDN/T FEEL COMFORTABLE
WITH ISSUING A WATCH AT THIS PERIOD. THEREFORE...HAVE ISSUED AN SPS
FOR PORTIONS OF WESTERN UPPER MICHIGAN AND WILL ALLOW THE SHIFT
TONIGHT TO SEE IF THE TRENDS FROM THE 12Z RUNS CONTINUE.
BEHIND THE SYSTEM...MODELS ARE FAIRLY CONSISTENT ON A STRONG
CANADIAN HIGH DEVELOPING IN THE PRAIRIES AND SHIFTING EAST TO
HUDSON BAY EARLY NEXT WEEK. THAT WILL LEAD TO DRY
NORTH-NORTHEASTERLY FLOW OVER THE AREA INTO THE FIRST HALF OF NEXT
WEEK. THAT FLOW REGIME SHOULD KEEP TEMPERATURES BELOW NORMAL
(POTENTIALLY NEARING RECORD LOW HIGH TEMPS AT OUR OFFICE) AND ANY
PRECIP ASSOCIATED WITH THE UPPER TROUGH MOVING THROUGH THE
CENTRAL/SOUTHERN PLAINS SOUTH OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EDT TUE APR 22 2014
GUSTY NW WINDS TO 20-25KT AT KCMX/KSAW WILL DIMINISH...ESPECIALLY
LATE AFTN...WITH THE SLOW APPROACH OF HIGH PRES FROM THE PLAINS AND
A WEAKENING PRES GRADIENT. WITH DRIER AIR ARRIVING FROM THE N AND W
ALONG WITH DAYTIME MIXING...EXPECT MVFR CIGS AT KSAW/KCMX TO LIFT
ABOVE 3KFT OR TO SCATTER OUT LATER THIS AFTN. KIWD HAS ALREADY
TRENDED VFR. SCATTERED FLURRIES/SPRINKLES WILL ALSO END IN THE NEXT
FEW HRS. DRY AIR MASS WILL THEN DOMINATE TONIGHT THRU WED...
RESULTING IN LIGHT WINDS/VFR CONDITIONS AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT TUE APR 22 2014
AS HIGH PRES RIDGE EXTENDING FROM MN SOUTHWARD SHIFTS TO WRN LAKE
SUPERIOR/WRN UPPER MI TONIGHT...WINDS WILL CONTINUE TO DIMINISH FROM W
TO E. WINDS ARE ALREADY LIGHT OVER THE WRN LAKE...AND THE INITIAL NW
20-30KT WINDS OVER ERN LAKE SUPERIOR WILL DROP TO UNDER 15KT
TONIGHT. LIGHT WINDS WILL LINGER THRU WED AS HIGH PRES RIDGE SLOWLY
DRIFTS E. HOWEVER...E WINDS WILL BEGIN TO INCREASE TOWARD 20KT OVER
FAR WRN LAKE SUPERIOR IN THE AFTN. EASTERLY WINDS WILL THEN
GRADUALLY INCREASE WED NIGHT AND WILL REACH 20-30KT ACROSS MUCH OF
LAKE SUPERIOR THU IN ADVANCE OF LOW PRES APPROACHING THE WRN GREAT
LAKES. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LOW...NOT
OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING/COASTAL CONVERGENCE
WOULD ENHANCE THIS E WIND. AS THE LOW SHIFTS TO THE E LATER ON FRI
INTO SAT AHEAD OF HIGH PRES BUILDING INTO SCENTRAL CANADA...THE WIND
WILL SHIFT TO THE N AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF
THE HIGH ON SAT. BEST CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD
BE OVER THE E HALF OF THE LAKE...AGAIN...DEPENDING ON INTENSITY OF
THE LOW.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 PM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EDT TUE APR 22 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A
SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR
TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS
PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND
LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER
CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS
BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY
DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE
CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN.
FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE
REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER
THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED
TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER
MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR
KIWD.
CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY
THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS
MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND
W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN
AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A
CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC
HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL
SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER
IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT
OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL
EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS...
BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR
23 IS 17F. MIGHT BE CLOSE TO THAT.
ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO
INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST
DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR
DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE
BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY
30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING
POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM
NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST
SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER.
WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS
FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED
ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
12Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-1.0IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN W OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EDT TUE APR 22 2014
GUSTY NW WINDS TO 20-25KT AT KCMX/KSAW WILL DIMINISH...ESPECIALLY
LATE AFTN...WITH THE SLOW APPROACH OF HIGH PRES FROM THE PLAINS AND
A WEAKENING PRES GRADIENT. WITH DRIER AIR ARRIVING FROM THE N AND W
ALONG WITH DAYTIME MIXING...EXPECT MVFR CIGS AT KSAW/KCMX TO LIFT
ABOVE 3KFT OR TO SCATTER OUT LATER THIS AFTN. KIWD HAS ALREADY
TRENDED VFR. SCATTERED FLURRIES/SPRINKLES WILL ALSO END IN THE NEXT
FEW HRS. DRY AIR MASS WILL THEN DOMINATE TONIGHT THRU WED...
RESULTING IN LIGHT WINDS/VFR CONDITIONS AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT TUE APR 22 2014
AS HIGH PRES RIDGE EXTENDING FROM MN SOUTHWARD SHIFTS TO WRN LAKE
SUPERIOR/WRN UPPER MI TONIGHT...WINDS WILL CONTINUE TO DIMINISH FROM W
TO E. WINDS ARE ALREADY LIGHT OVER THE WRN LAKE...AND THE INITIAL NW
20-30KT WINDS OVER ERN LAKE SUPERIOR WILL DROP TO UNDER 15KT
TONIGHT. LIGHT WINDS WILL LINGER THRU WED AS HIGH PRES RIDGE SLOWLY
DRIFTS E. HOWEVER...E WINDS WILL BEGIN TO INCREASE TOWARD 20KT OVER
FAR WRN LAKE SUPERIOR IN THE AFTN. EASTERLY WINDS WILL THEN
GRADUALLY INCREASE WED NIGHT AND WILL REACH 20-30KT ACROSS MUCH OF
LAKE SUPERIOR THU IN ADVANCE OF LOW PRES APPROACHING THE WRN GREAT
LAKES. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LOW...NOT
OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING/COASTAL CONVERGENCE
WOULD ENHANCE THIS E WIND. AS THE LOW SHIFTS TO THE E LATER ON FRI
INTO SAT AHEAD OF HIGH PRES BUILDING INTO SCENTRAL CANADA...THE WIND
WILL SHIFT TO THE N AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF
THE HIGH ON SAT. BEST CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD
BE OVER THE E HALF OF THE LAKE...AGAIN...DEPENDING ON INTENSITY OF
THE LOW.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 PM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
12Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-1.0IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN W OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EDT TUE APR 22 2014
GUSTY NW WINDS TO 20-25KT AT KCMX/KSAW WILL DIMINISH...ESPECIALLY
LATE AFTN...WITH THE SLOW APPROACH OF HIGH PRES FROM THE PLAINS AND
A WEAKENING PRES GRADIENT. WITH DRIER AIR ARRIVING FROM THE N AND W
ALONG WITH DAYTIME MIXING...EXPECT MVFR CIGS AT KSAW/KCMX TO LIFT
ABOVE 3KFT OR TO SCATTER OUT LATER THIS AFTN. KIWD HAS ALREADY
TRENDED VFR. SCATTERED FLURRIES/SPRINKLES WILL ALSO END IN THE NEXT
FEW HRS. DRY AIR MASS WILL THEN DOMINATE TONIGHT THRU WED...
RESULTING IN LIGHT WINDS/VFR CONDITIONS AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
1031 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
12Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-1.0IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN W OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 721 AM EDT TUE APR 22 2014
GUSTY NW WINDS UP TO 25 KTS WILL DIMINISH WITH THE SLOW APPROACH OF
HI PRES FROM THE PLAINS AND A WEAKER PRES GRADIENT THIS AFTN. WITH
THE ARRIVAL OF DRIER AIR THIS AFTN AND DAYTIME MIXING...EXPECT MVFR
CIGS AT SAW AND PERHAPS CMX THIS MRNG TO GIVE TO VFR CONDITIONS. VFR
CONDITIONS AND LIGHTER WINDS WL BE THE RULE TNGT AS THE SFC HI PRES
RDG MOVES INTO THE GREAT LKS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
906 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
12Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-0.1IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN W OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 721 AM EDT TUE APR 22 2014
GUSTY NW WINDS UP TO 25 KTS WILL DIMINISH WITH THE SLOW APPROACH OF
HI PRES FROM THE PLAINS AND A WEAKER PRES GRADIENT THIS AFTN. WITH
THE ARRIVAL OF DRIER AIR THIS AFTN AND DAYTIME MIXING...EXPECT MVFR
CIGS AT SAW AND PERHAPS CMX THIS MRNG TO GIVE TO VFR CONDITIONS. VFR
CONDITIONS AND LIGHTER WINDS WL BE THE RULE TNGT AS THE SFC HI PRES
RDG MOVES INTO THE GREAT LKS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
722 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
1Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-0.1IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN E OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 721 AM EDT TUE APR 22 2014
GUSTY NW WINDS UP TO 25 KTS WILL DIMINISH WITH THE SLOW APPROACH OF
HI PRES FROM THE PLAINS AND A WEAKER PRES GRADIENT THIS AFTN. WITH
THE ARRIVAL OF DRIER AIR THIS AFTN AND DAYTIME MIXING...EXPECT MVFR
CIGS AT SAW AND PERHAPS CMX THIS MRNG TO GIVE TO VFR CONDITIONS. VFR
CONDITIONS AND LIGHTER WINDS WL BE THE RULE TNGT AS THE SFC HI PRES
RDG MOVES INTO THE GREAT LKS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
549 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 548 AM EDT TUE APR 22 2014
WILL CONCENTRATE MUCH OF THIS DISCUSSION OF THE UPCOMING END OF THE
WORK WEEK/START OF THE WEEKEND SYSTEM.
HOWEVER...WE WILL START OFF THE PERIOD WITH THE SFC HIGH OVERHEAD AT
1Z WEDNESDAY. THE HIGH WILL SLOWLY SHIFT E THROUGH THE DAY...WITH
LAKE BREEZES DOMINATING DURING THE AFTERNOON HRS...WITH HIGHS
TOPPING OUT IN THE LOW TO MID 50S INTERIOR W HALF.
THE DOUBLE BARREL LOW WILL STRETCH FROM S SASKATCHEWAN THROUGH IA AT
12Z THURSDAY...WITH INCREASED MOISTURE OF SE WINDS ACROSS UPPER MI.
850MB WINDS OF 40-50KT ARE STILL SHOWING UP BY 18Z OVER THE W
HALF...WITH GUSTS ON THE ORDER OF 20-25KTS MAKING IT TO THE SFC.
RAIN WILL QUICKLY SPREAD IN THROUGH THE DAY...WITH THE SFC LOWS
ALIGNING FROM NE TO WI BY 00Z FRIDAY.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY ON THURSDAY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI...CLOSER TO THE S SFC LOW OVER WI
DURING THE DAY THURSDAY. STILL HAVE 0.5-0.1IN OF LIQUID ACROSS MUCH
OF THE CWA...WITH OVER 0.75IN E OF A LINE FROM BIG BAY TO MNM.
UPDATED HWO TO INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. GIVEN THE POTENTIAL FOR THE COLD AIR TO SLIP
ACROSS BARAGA AND MARQUETTE COUNTIES...INCLUDED THE THREAT FOR THEM
AS WELL. HAVE 4-7IN OF SNOW IN THE FCST FROM THURSDAY THROUGH FRIDAY
NIGHT ACROSS THE KEWEENAW PENINSULA...WITH MOST OF THAT FALLING
THURSDAY NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY
FCST SO EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE
IT/S ALL SAID AND DONE...WITH THE POTENTIAL FOR WINTER WEATHER
ADVISORIES. MAY HAVE 2-5IN MORE SNOW THAN WHAT IS FCST OVER THE
KEWEENAW IF THE COLDER AIR WINS OUT...AND SLR/S OF 10-15:1 OCCUR
LIKE BUFKIT IS PAINTING OUT FOR THE GFS. CURRENTLY HAVE RATIOS
CLOSER TO 10:1 IN OUR ONGOING FCST.
THE NEARLY STACKED SFC TO 500MB LOW ACROSS NE AND S MANITOBA AT 00Z
FRIDAY WILL PUSH ACROSS THE CWA THURSDAY NIGHT...AND EXIT OVER AND E
OF LAKE SUPERIOR BY 00Z SATURDAY. COLDER AIR WILL FINALLY PUSH INTO
W AND CENTRAL UPPER MI TO RESULT IN ALL SNOW FRIDAY NIGHT...WITH
850MB TEMPS FALLING TO -6 TO -8C. FAVORABLE NORTHERLY FLOW OFF THE
BROKEN/ICE COVERED WATERS OF LAKE SUPERIOR SHOULD BE ENOUGH FOR A
LITTLE LAKE ENHANCEMENT BEFORE MUCH DRIER AIR WORKS IN ON SATURDAY.
THE HUDSON BAY HIGH WILL DOMINATE OUR FCST THROUGH THE REST OF THE
PERIOD...WITH COOL N FLOW LINGERING ACROSS THE CWA. THE 60 AND 70
DEGREE TEMPS OF YESTERDAY WILL BE JUST A MEMORY...WITH 30S AND 40S
FOR HIGHS THURSDAY THROUGH AT LEAST NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE APR 22 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS POTENTIAL SOME MVFR CLOUDS INTO THE UPPER
LAKES OVERNIGHT INTO EARLY TUESDAY. MVFR CIGS HAVE ALREADY RETURNED
AT KCMX...AND GUIDANCE SUGGEST MVFR CIGS SHOULD ARRIVE AROUND 10Z
LATE TONIGHT AT KIWD AND KSAW. ARRIVAL OF DRIER AIR WILL RESULT IN
CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN AND MID TO
LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS/KC
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
453 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM EDT TUE APR 22 2014
PRELIMINARY LONG TERM...WILL CONCENTRATE MUCH OF THIS DISCUSSION OF
THE UPCOMING END OF THE WORK WEEK/START OF THE WEEKEND SYSTEM.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI. STILL HAVE 0.5-0.1IN OF LIQUID
ACROSS MUCH OF THE CWA...WITH OVER 0.75IN E OF A LINE FROM BIG BAY
TO MNM.
WILL UPDATE HWO WILL INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. HAVE 4 TO 7IN OF SNOW IN THE FCST FROM
THURSDAY THROUGH FRIDAY NIGHT...WITH MOST OF THAT FALLING THURSDAY
NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY FCST SO
EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE IT/S ALL
SAID AND DONE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE APR 22 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS POTENTIAL SOME MVFR CLOUDS INTO THE UPPER
LAKES OVERNIGHT INTO EARLY TUESDAY. MVFR CIGS HAVE ALREADY RETURNED
AT KCMX...AND GUIDANCE SUGGEST MVFR CIGS SHOULD ARRIVE AROUND 10Z
LATE TONIGHT AT KIWD AND KSAW. ARRIVAL OF DRIER AIR WILL RESULT IN
CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN AND MID TO
LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 452 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...HARVEY/
HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT HYDE/FRDM4/ ON
THE FORD RIVER /...WHICH LOOKS TO BE FLUCTUATING DUE TO ICE JAM
ISSUES/. GIVEN INCREASED DISCHARGE FROM THE PRICKETT DAM JUST
UPSTREAM OF THE ALSM4 GAUGE ON THE STURGEON RIVER...THE RIVER AT
THAT LOCATION ROSE TO NEAR BANKFULL EARLY TUE MRNG. ISSUED A RIVER
STATEMENT TO ACCOUNT FOR THESE HIGHER LEVELS. BUT SINCE SNOW MELT
THE NEXT FEW DAYS WL BE DIMINISHING...EXPECT THE RIVER TO SLOWLY
SUBSIDE AND NOT EXCEED FLOOD STAGE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY RISE TO NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS
ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS
THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND
BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS/KC
MARINE...KC
HYDROLOGY...KF/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 AM EDT TUE APR 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 437 AM EDT TUE APR 22 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
DIGGING SEWD THRU ONTARIO DEEPENING AN UPR TROF OVER THE GREAT LKS
DOWNSTREAM OF FAIRLY SHARP UPR RDG OVER THE ROCKIES. ASSOCIATED SFC
COLD FNT HAS PASSED THRU UPR MI...AND GUSTY NW WINDS AS HI AS 30-35
MPH IN ITS WAKE HAVE ADVECTED COOLER AIR BACK OVER UPR MI. THE 00Z
H85 TEMPS WERE AS LO AS -6C AT INL AND -7C AT YPL. ALTHOUGH A GOOD
DEAL OF LOWER CLDS HAVE RETURNED WITH THE COOLER AIR...DRY NATURE OF
THE NEAR SFC LYR SHOWN ON THE WELL MIXED 00Z INL RAOB UNDER
STRENGTHENING SUBSIDENCE ARND H8 AND SFC DEWPT DEPRESSIONS ARND 10F
UPSTREAM HAVE SO FAR LIMITED THE PCPN TO JUST A FEW FLURRIES. THE
00Z YPL RAOB IS MORE MOIST FM THE SFC TO ABOUT H6...AND THERE HAVE
BEEN SOME LGT SN SHOWERS REPORTED AT SOME PLACES TO THE N OF THUNDER
BAY UNDER THE DEEPER MSTR. TO THE W TOWARD THE ROCKIES UPR RDG...SFC
HI PRES AND MUCH DRIER AIRMASS DEPICTED ON THE 00Z BISMARCK RAOB ARE
RESULTING IN MOCLR CONDITIONS OVER MOST OF MN EXCEPT THE ARROWHEAD
AND THE HI PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM INCLUDE LGT PCPN CHCS/PTYPE.
FOCUS FOR THIS AFTN/TNGT SHIFTS TO CLRG TRENDS AND HOW LO TEMPS
MIGHT FALL AS THE HI PRES RDG/DRY AIRMASS TO THE W DRIFT INTO THE
AREA.
TODAY...AS THE GUSTY NW WIND VEERS MORE TO THE NNW EARLY THIS MRNG
AND DRAWS THE COLDER LLVL AIR UPSTREAM OVHD...EXPECT EXPANDING LO
CLD COVERAGE UNDER SHARPENING SUBSIDENCE INVRN ACCOMPANYING DEEP LYR
QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. THE MORE NNW
WIND SHOULD ALSO ALLOW SOME OF THE LOWER DEWPT DEPRESSIONS OVER
ONTARIO TO THE N OF THUNDER BAY TO ADVECT INTO THE ERN CWA. THE W
SHOULD BE MORE DOMINATED BY THE DRIER NEAR SFC AIR SHOWN ON THE INL
RAOB AND OVER THE MN ARROWHEAD. KEPT MENTION OF FLURRIES OVER THE NW
CWA BUT REMOVED THE MENTION OF DRIZZLE/FRZG DRIZZLE IN THAT AREA TO
ACCOUNT FOR THE DRIER NATURE OF THE LLVL THAT WOULD TEND TO
EVAPORATE THE SMALLER WATER DROPLETS MORE EFFICIENTLY. ALTHOUGH THE
MOISTER LLVL AIR WL BE MOVING INTO THE ERN CWA...THE SHARPENING
SUBSIDENCE INVRN/MID LVL DRYING SHOULD LIMIT THE POTENTIAL FOR SGNFT
ICE CRYSTAL GROWTH AS THE MOIST LYR WL BE UNDER THE DGZ. INCOMING
AIRMASS WL BE TOO WARM FOR LK EFFECT PCPN. SO WHATEVER PCPN FALLS IN
THAT AREA SHOULD TEND MORE TOWARD DRIZZLE/FRZG DRIZZLE OR PERHAPS
SMALLER SN GRAINS/FLURRIES. DURING THE AFTN...THE COMBINATION OF
DAYTIME HEATING AND SOME DRY ADVECTION AS THE NNW FLOW TAPS DRIER
AIR NOW IN PLACE FARTHER NW IN ONTARIO SHOULD RESULT IN A CLRG
TREND. THE SC WL BE MORE TENACIOUS OVER THE E CLOSER TO THE LLVL
THERMAL TROF. GUSTY WINDS AND SFC TEMPS STRUGGLING TO RISE OUT OF
THE MID/UPR 30S OVER THE HIER TERRAIN TO THE 40S ELSEWHERE WL MAKE
FOR A MUCH COLDER DAY COMPARED TO YDAY...WITH HI TEMPS AS MUCH AS 30
DEGREES LOWER THAN ON MON.
TNGT...AS THE HI PRES RDG TO THE W MOVES INTO THE GREAT LKS AND
DRIER LLVL AIR ARRIVES...EXPECT LINGERING CLDS OVER MAINLY THE
CENTRAL AND E TO GIVE WAY TO CLRG. WITH PWAT FALLING UNDER 0.25 INCH
/AS LO AS 40 PCT OR NORMAL/ AND DIMINISHING WINDS...EXPECT THE
LOWEST TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR W HALF.
LATER CLRG AND STEADIER N WINDS OVER THE E WL RESTRICT THE DIURNAL
FALL OF TEMP THERE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM EDT TUE APR 22 2014
PRELIMINARY LONG TERM...WILL CONCENTRATE MUCH OF THIS DISCUSSION OF
THE UPCOMING END OF THE WORK WEEK/START OF THE WEEKEND SYSTEM.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI. STILL HAVE 0.5-0.1IN OF LIQUID
ACROSS MUCH OF THE CWA...WITH OVER 0.75IN E OF A LINE FROM BIG BAY
TO MNM.
WILL UPDATE HWO WILL INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. HAVE 4 TO 7IN OF SNOW IN THE FCST FROM
THURSDAY THROUGH FRIDAY NIGHT...WITH MOST OF THAT FALLING THURSDAY
NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY FCST SO
EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE IT/S ALL
SAID AND DONE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE APR 22 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS POTENTIAL SOME MVFR CLOUDS INTO THE UPPER
LAKES OVERNIGHT INTO EARLY TUESDAY. MVFR CIGS HAVE ALREADY RETURNED
AT KCMX...AND GUIDANCE SUGGEST MVFR CIGS SHOULD ARRIVE AROUND 10Z
LATE TONIGHT AT KIWD AND KSAW. ARRIVAL OF DRIER AIR WILL RESULT IN
CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN AND MID TO
LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 AM EDT TUE APR 22 2014
AS EXPECTED...RIBBON OF STRONGER NNW WINDS ADVECTING COLDER AIR INTO
THE UPPER LAKES HAS RESULED IN SOME MARGINAL GALE FORCE WIND GUSTS
OVER PORTIONS OF THE CENTRAL LAKE EARLY THIS MORNING. AS HI PRES TO
THE W SHIFTS TO THE E TODAY...THE GRADIENT WILL WEAKEN. SO GALE
FORCE GUSTS TO 35 KTS THIS MORNING WILL DIMINISH THIS AFTERNOON.
WINDS WILL DIMINISH TO UNDER 15 KTS TONIGHT THRU WED AS THE HI PRES
RIDGE MOVES THRU THE GREAT LAKES. E WINDS WILL THEN INCREASE AS HI
AS 25-30 KTS ON THU INTO AS THE GRADIENT TIGHTENS OVER THE UPPER
LAKES BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE
PLAINS. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LO...NOT
OUT OF THE QUESTION THERE COULD BE SOME GALE FORCE WINDS OVER
WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING WOULD ENHANCE THIS E
WIND. AS THE LO SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HI
PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N
AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HI ON SAT. BEST
CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 1229 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT
RIVER...HARVEY/HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT
HYDE/FRDM4/ ON THE FORD RIVER /WHICH LOOKS TO BE FLUCTUATING DUE TO
ICE JAM ISSUES/.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE
REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER
LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN
FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER
LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS/KC
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 AM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON APR 21 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACROSS
THE CNTRL AND ERN CONUS. IN THE NRN STREAM...A VIGOROUS SHORTWAVE
WAS MOVING ACROSS NRN ONTARIO JUST TO THE N OF LAKE SUPERIOR. IN THE
SRN STREAM...ANOTHER WAVE WAS MOVING ACROSS THE MID AND LWR
MISSISSIPPI VALLEY. DESPITE STRENGTH AND PROXIMITY OF NRN STREAM
WAVE...IT`S ONLY BEEN IN THE LAST HR THAT ISOLD -SHRA HAVE MANAGED
TO DEVELOP ALONG ASSOCIATED SFC COLD FRONT WHICH IS RUNNING FROM
NEAR ISLE ROYALE ACROSS THE KEWEENAW AND THEN S THRU IRON COUNTY.
LIMITED COVERAGE IS DUE TO LACK OF INSTABILITY AND THE FACT THAT
DEEP LAYER FORCING WITH WAVE IS PASSING MOSTLY N OF UPPER MI.
OVER THE NEXT SEVERAL HRS...WILL CARRY MAINLY ISOLD -SHRA COVERAGE
ALONG COLD FRONT AS IT SWEEPS E. ATTENTION THEN TURNS TO HEALTHY CAA
AND LOW CLOUD/-FZDZ/DZ POTENTIAL. WITH 850MB TEMPS FALLING TO AROUND
-8C...LAKE EFFECT PCPN WON`T BE A CONCERN TONIGHT INTO TUE MORNING.
HOWEVER...MODELS CONTINUE TO SHOW SIGNIFICANT LOW-LEVEL MOISTENING
TONIGHT WHICH APPEARS ON TRACK GIVEN IFR CIGS THAT WERE OBSERVED
UPSTREAM IN NRN MN/ADJACENT ONTARIO EARLIER TODAY. DAYTIME HEATING
HAS RAISED CIGS...BUT CLOUDS CONTINUE TO HEAD SE EVEN THOUGH SLOWED
BY MIXING OUT OF MOISTURE AT THE LEADING EDGE. ONCE DAYTIME HEATING
DIMINISHES...CLOUDS WILL MAKE A QUICKER RUN TO THE SE INTO UPPER
MI. EXAMINATION OF FCST SOUNDINGS SHOW MOISTURE DEPTH INCREASES TO
800 TO 700MB...AND WITH TEMPS WITHIN THE MOISTURE DEPTH WARMER THAN
-10C...PRESENCE OF ICE CRYSTALS IS UNLIKELY. SO...IF THERE IS ANY
PCPN...PTYPE SHOULD BE JUST -DZ/-FZDZ. HOWEVER...SINCE MODEL TREND
HAS BEEN FOR MOISTURE DEPTH TO BE DEEPER AND CLOSER TO -10C...WILL
INCLUDE A MENTION OF FLURRIES AS WELL. WHILE CONFIDENCE IS NOT
HIGH...WILL CONTINUE WITH LOW POPS FOR -DZ/-FZDZ/FLURRIES
OVERNIGHT THRU TUE MORNING...MAINLY IN THE AREAS WHERE UPSLOPING
OCCURS WITH A NNW WIND. WITH THE BETTER MOISTURE OVER THE E...WILL
NOT MENTION ANY PCPN OVER THE FAR W.
ON TUE...IT APPEARS NOW THAT CLEARING TREND WILL BE SLOWER WITH
850MB TROF FIRMLY OVER THE FCST AREA AT 18Z. ANY LOCATIONS THAT
START THE DAY WITH SOME SUNSHINE WILL SEE CU/STRATOCU RAPIDLY
DEVELOP. DURING THE MID AND LATE AFTN...THE LAKE WILL BECOME A
STABILIZING INFLUENCE...RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKE FIRST. THEN...THE CLEARING WILL SPREAD INLAND. WITH GRADIENT
N/NW WINDS ENHANCED BY LAKE BREEZE...IT WILL BE A BLUSTERY/SHARPLY
COLDER DAY WITH TEMPS 20 TO POSSIBLY AS MUCH AS 30 DEGREES COLDER IN
SOME SPOTS. IT WILL BE ESPECIALLY CHILLY ALONG LAKE SUPERIOR
WHERE TEMPS WON`T GET ABOVE THE MID 30S AT BEST. OVER THE FAR
SCNTRL...TEMPS MAY RISE TO AROUND 50F.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM EDT TUE APR 22 2014
PRELIMINARY LONG TERM...WILL CONCENTRATE MUCH OF THIS DISCUSSION OF
THE UPCOMING END OF THE WORK WEEK/START OF THE WEEKEND SYSTEM.
THE SOUNDINGS ARE NEARLY ISOTHERMAL ACROSS THE KEWEENAW
PENINSULA...WITH TEMPS HOVERING RIGHT AROUND 0C...WITH A SLIGHT
CHANGE IN THE PROFILE RESULTING IN ALL RAIN OR ALL SNOW. ROADWAYS
MAY BE SPARED INITIALLY FROM ANY ACCUMULATING SNOW AS NEAR-SFC TEMPS
RISE INTO THE UPPER 30S TEMPORARILY.
LOOKS TO BE PLENTY OF MOISTURE AVAILABLE WITH THE DGZ BETWEEN 500
AND 600MB THROUGH THE EVENT. ONE CHANGE HAS BEEN A PUSH FOR HIGHER
PRECIP S OF THE BORDER INTO WI. STILL HAVE 0.5-0.1IN OF LIQUID
ACROSS MUCH OF THE CWA...WITH OVER 0.75IN E OF A LINE FROM BIG BAY
TO MNM.
WILL UPDATE HWO WILL INCLUDE THE MENTION OF LIGHT TO MODERATE SNOW
POTENTIAL...MAINLY ACROSS THE KEWEENAW PENINSULA...AND ELEVATED RISK
IN THE EHWO GRAPHICS. HAVE 4 TO 7IN OF SNOW IN THE FCST FROM
THURSDAY THROUGH FRIDAY NIGHT...WITH MOST OF THAT FALLING THURSDAY
NIGHT INTO FRIDAY MORNING. AS NOTED ABOVE...IT/S A TRICKY FCST SO
EXPECT A FEW MORE CHANGES TO THE CURRENT THINKING BEFORE IT/S ALL
SAID AND DONE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE APR 22 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS POTENTIAL SOME MVFR CLOUDS INTO THE UPPER
LAKES OVERNIGHT INTO EARLY TUESDAY. MVFR CIGS HAVE ALREADY RETURNED
AT KCMX...AND GUIDANCE SUGGEST MVFR CIGS SHOULD ARRIVE AROUND 10Z
LATE TONIGHT AT KIWD AND KSAW. ARRIVAL OF DRIER AIR WILL RESULT IN
CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN AND MID TO
LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON APR 21 2014
IN THE WAKE OF A COLD FRONT CURRENTLY PASSING ACROSS LAKE
SUPERIOR...NW WINDS WILL INCREASE TO 15-30KT TONIGHT. STRONGEST
WINDS WILL BE IN A CORRIDOR FROM NCNTRL TO SCNTRL/SE LAKE SUPERIOR
WHERE SOME GALE FORCE GUSTS WILL PROBABLY OCCUR...MOSTLY IN THE
OVERNIGHT/EARLY TUE MORNING TIME PERIOD. THESE STONG WINDS WILL
DIMINISH FROM W TO E TUE INTO TUE EVENING AS A HIGH PRES RIDGE
ARRIVES. WINDS WILL FALL TO UNDER 15KT TUE NIGHT WITH LIGHT WINDS
LINGERING THRU AT LEAST WED MORNING AS HIGH PRES SLOWLY EXITS TO THE
E. OVER WRN LAKE SUPERIOR...NE WINDS WILL BE ON THE INCREASE WED
AFTN. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS
LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...EASTERLY WINDS
WILL BE ON THE INCREASE THU. WINDS WILL THEN BACK AROUND TO THE N
FRI AS THE LOW PASSES ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE
TRACK AND INTENSITY OF THIS LOW...THERE COULD SOME GALE FORCE
WINDS...POSSIBLY OVER WRN LAKE SUPERIOR AHEAD OF THE LOW AND THEN
OVER CNTRL AND ERN LAKE SUPERIOR AS THE LOW PASSES TO THE E.
&&
.HYDROLOGY...
ISSUED AT 1229 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT
RIVER...HARVEY/HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT
HYDE/FRDM4/ ON THE FORD RIVER /WHICH LOOKS TO BE FLUCTUATING DUE TO
ICE JAM ISSUES/.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE
REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER
LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN
FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER
LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS/KC
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON APR 21 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACROSS
THE CNTRL AND ERN CONUS. IN THE NRN STREAM...A VIGOROUS SHORTWAVE
WAS MOVING ACROSS NRN ONTARIO JUST TO THE N OF LAKE SUPERIOR. IN THE
SRN STREAM...ANOTHER WAVE WAS MOVING ACROSS THE MID AND LWR
MISSISSIPPI VALLEY. DESPITE STRENGTH AND PROXIMITY OF NRN STREAM
WAVE...IT`S ONLY BEEN IN THE LAST HR THAT ISOLD -SHRA HAVE MANAGED
TO DEVELOP ALONG ASSOCIATED SFC COLD FRONT WHICH IS RUNNING FROM
NEAR ISLE ROYALE ACROSS THE KEWEENAW AND THEN S THRU IRON COUNTY.
LIMITED COVERAGE IS DUE TO LACK OF INSTABILITY AND THE FACT THAT
DEEP LAYER FORCING WITH WAVE IS PASSING MOSTLY N OF UPPER MI.
OVER THE NEXT SEVERAL HRS...WILL CARRY MAINLY ISOLD -SHRA COVERAGE
ALONG COLD FRONT AS IT SWEEPS E. ATTENTION THEN TURNS TO HEALTHY CAA
AND LOW CLOUD/-FZDZ/DZ POTENTIAL. WITH 850MB TEMPS FALLING TO AROUND
-8C...LAKE EFFECT PCPN WON`T BE A CONCERN TONIGHT INTO TUE MORNING.
HOWEVER...MODELS CONTINUE TO SHOW SIGNIFICANT LOW-LEVEL MOISTENING
TONIGHT WHICH APPEARS ON TRACK GIVEN IFR CIGS THAT WERE OBSERVED
UPSTREAM IN NRN MN/ADJACENT ONTARIO EARLIER TODAY. DAYTIME HEATING
HAS RAISED CIGS...BUT CLOUDS CONTINUE TO HEAD SE EVEN THOUGH SLOWED
BY MIXING OUT OF MOISTURE AT THE LEADING EDGE. ONCE DAYTIME HEATING
DIMINISHES...CLOUDS WILL MAKE A QUICKER RUN TO THE SE INTO UPPER
MI. EXAMINATION OF FCST SOUNDINGS SHOW MOISTURE DEPTH INCREASES TO
800 TO 700MB...AND WITH TEMPS WITHIN THE MOISTURE DEPTH WARMER THAN
-10C...PRESENCE OF ICE CRYSTALS IS UNLIKELY. SO...IF THERE IS ANY
PCPN...PTYPE SHOULD BE JUST -DZ/-FZDZ. HOWEVER...SINCE MODEL TREND
HAS BEEN FOR MOISTURE DEPTH TO BE DEEPER AND CLOSER TO -10C...WILL
INCLUDE A MENTION OF FLURRIES AS WELL. WHILE CONFIDENCE IS NOT
HIGH...WILL CONTINUE WITH LOW POPS FOR -DZ/-FZDZ/FLURRIES
OVERNIGHT THRU TUE MORNING...MAINLY IN THE AREAS WHERE UPSLOPING
OCCURS WITH A NNW WIND. WITH THE BETTER MOISTURE OVER THE E...WILL
NOT MENTION ANY PCPN OVER THE FAR W.
ON TUE...IT APPEARS NOW THAT CLEARING TREND WILL BE SLOWER WITH
850MB TROF FIRMLY OVER THE FCST AREA AT 18Z. ANY LOCATIONS THAT
START THE DAY WITH SOME SUNSHINE WILL SEE CU/STRATOCU RAPIDLY
DEVELOP. DURING THE MID AND LATE AFTN...THE LAKE WILL BECOME A
STABILIZING INFLUENCE...RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKE FIRST. THEN...THE CLEARING WILL SPREAD INLAND. WITH GRADIENT
N/NW WINDS ENHANCED BY LAKE BREEZE...IT WILL BE A BLUSTERY/SHARPLY
COLDER DAY WITH TEMPS 20 TO POSSIBLY AS MUCH AS 30 DEGREES COLDER IN
SOME SPOTS. IT WILL BE ESPECIALLY CHILLY ALONG LAKE SUPERIOR
WHERE TEMPS WON`T GET ABOVE THE MID 30S AT BEST. OVER THE FAR
SCNTRL...TEMPS MAY RISE TO AROUND 50F.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 409 PM EDT MON APR 21 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION ON TUESDAY
WILL LEAD TO A DRY PERIOD FOR TUESDAY NIGHT AND MUCH OF WEDNESDAY.
THERE MAY BE A FEW LINGERING CLOUDS OVER THE FAR EAST TO START THE
EVENING...BUT OTHERWISE EXPECT MOSTLY CLEAR SKIES TUESDAY NIGHT AND
INTO WEDNESDAY ACROSS THE U.P. LOWS ON TUESDAY NIGHT WILL BE BELOW
NORMAL AND IN THE 20S FOR MOST LOCATIONS. DID TREND SOME OF THE
INTERIOR COLD SPOTS IN THE TEENS SINCE THE HIGH WILL BE OVERHEAD
AND PWATS OF 40-45 PERCENT OF NORMAL WOULD SUPPORT GOING AT OR
BELOW MOS GUIDANCE. THE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK
CLOSER TO NORMAL FOR WEDNESDAY. LIGHT WINDS WILL GRADUALLY TURN TO
THE SOUTHEAST DURING THE AFTERNOON...BUT THEY SHOULD BE LIGHT
ENOUGH TO ALLOW LAKE BREEZES TO DEVELOP NEAR THE GREAT LAKES
SHORELINES AND KEEP TEMPERATURES COOLER THERE.
THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION WEDNESDAY NIGHT AND LIKELY CONTINUING INTO SATURDAY.
THIS UPPER TROUGH IS CURRENTLY WEST OF THE PACIFIC NORTHWEST AND
WILL COME ONSHORE TONIGHT. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. AS THIS OCCURS...BROAD ISENTROPIC ASCENT ON THE 290-305K
SURFACES WILL SPREAD NORTHEAST INTO UPPER MICHIGAN ON WEDNESDAY
NIGHT. THIS FIRST WAVE WILL STEADILY PUSH NORTHEAST THROUGH
THURSDAY...WHILE A SECONDARY WAVE OF PRECIPITATION MOVES IN ON
THURSDAY AHEAD OF THE UPPER TROUGH AXIS MOVES INTO THE UPPER
MISSISSIPPI VALLEY AND NEARS THE UPPER GREAT LAKES. THIS UPPER
TROUGH WILL SHIFT THE HEAVIEST PRECIPITATION OVER THE NORTHERN
HALF OF LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WITH THE
MOISTURE PRESENT AND FORCING FROM THE UPPER TROUGH...WOULD EXPECT
LINGERING LIGHT SHOWERS TO BE ONGOING OVER THE AREA FRIDAY INTO
FRIDAY NIGHT. PRECIPITATION TYPE IS VERY TRICKY AT THIS POINT DUE TO
THE VARYING SOLUTIONS IN THE MODELS WITH THE THERMAL FIELD WEDNESDAY
NIGHT INTO THURSDAY. AS THE INITIAL SURGE OF PRECIP MOVES INTO THE
AREA...IT ENCOUNTERS A ISOTHERMAL LAYER FROM THE SURFACE THROUGH
700MB WITH TEMPERATURES AT OR JUST ABOVE FREEZING. THIS LAYER
REMAINS STEADY THROUGH MUCH OF THURSDAY. AS FOR THE MODELS...THE
12Z GFS HAS TRENDED A LITTLE COOLER COMPARED TO THE PREVIOUS
RUNS...THE 12Z ECMWF REMAINS THE COOLEST AND THE 12Z GEM IS
IN BETWEEN INITIALLY. UNFORTUNATELY IT IS DIFFICULT TO GET TOO
SPECIFIC IN THESE SITUATIONS AS JUST A SLIGHT CHANGE IN TEMPERATURE
BETWEEN 925-700MB OF 1-2C ONE WAY OR ANOTHER CAN MAKE A HUGE
DIFFERENCE IN THE PRECIP TYPE AND ASSOCIATED IMPACTS. THUS...WILL
FOLLOW AN IDEA OF RAIN/SNOW MIX WITH THE INITIAL SURGE OF PRECIP AND
LIKELY TRANSITIONING TO MORE RAIN DURING THE DAY THURSDAY (OVER
THE SOUTH HALF). THE NORTHWARD EXTENT OF THIS TRANSITION IS
UNCERTAIN AT THIS POINT AND WILL PLACE IT OVER THE NORTH HALF OF
LAKE SUPERIOR THURSDAY AFTERNOON/EVENING. COLDER AIR WILL BEGIN TO
SHIFT INTO THE AREA ON THURSDAY NIGHT AS THE LOW SHIFTS EAST ACROSS
UPPER MICHIGAN AND LEAD TO A TRANSITION TO ALL SNOW INTO FRIDAY. BY
THE TIME THE PRECIPITATION WILL START TO TRANSITION TO ALL
SNOW...THE HEAVIEST RATES WILL HAVE DEPARTED THE AREA AND EXPECT
MORE OF A SCATTERED/LIGHT PRECIP TO REMAIN. WILL CONTINUE THE
PREVIOUS SHIFTS IDEA OF THE HIGHEST QPF OVER THE WESTERN HALF OF
THE CWA AND AROUND 0.5-1.0IN THROUGH THURSDAY EVENING. THAT MATCHES
UP WELL WITH SOME OF THE ECMWF/GFS QPF PROBS. AS MENTIONED
EARLIER...SNOW POTENTIAL IS TRICKY BUT THE SLIGHTLY COOLER
TREND SEEN IN THE 12Z MODELS CREATES CONCERN FOR MEASURABLE (AND
POTENTIALLY SIGNIFICANT) SNOWFALL OVER THE KEWEENAW DUE TO ITS
CLOSER PROXIMITY TO THE COLDER AIR TO THE NORTH. FINALLY FOR THIS
SYSTEM...THE COLD AIR AND BREEZING CONDITIONS SURGING IN BEHIND THE
LOW ON FRIDAY AND INTO SATURDAY WILL MAKE IT FEEL MORE LIKE MARCH
ACROSS THE AREA. WIND CHILL VALUES FRIDAY NIGHT AND INTO SATURDAY
WILL BE IN THE TEENS AND 20S WITH THE LOWEST VALUES NEAR LAKE
SUPERIOR.
MODELS DO DIFFER ON HOW QUICKLY THE UPPER TROUGH DEPARTS THIS
WEEKEND...SO THE FORECAST FOR THE END OF THE WEEKEND AND INTO EARLY
NEXT WEEK IS UNCERTAIN. EVEN WITH THIS UNCERTAINTY...THE GENERAL
IDEA OF BELOW NORMAL TEMPERATURES FOR THE WEEKEND AND INTO THE FIRST
PART OF NEXT WEEK SEEMS REASONABLE AS A HUDSON BAY HIGH BECOMES
STATIONARY AND LEADS TO DRY NORTHEASTERLY FLOW. PRECIPITATION
CHANCES WILL DEPEND ON THE NEXT UPPER TROUGH THAT LOOKS TO BE
LOCATED IN THE CENTRAL/SOUTHERN PLAINS AND AT THIS TIME MAY BE FAR
ENOUGH SOUTH TO KEEP THE AREA DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE APR 22 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS POTENTIAL SOME MVFR CLOUDS INTO THE UPPER
LAKES OVERNIGHT INTO EARLY TUESDAY. MVFR CIGS HAVE ALREADY RETURNED
AT KCMX...AND GUIDANCE SUGGEST MVFR CIGS SHOULD ARRIVE AROUND 10Z
LATE TONIGHT AT KIWD AND KSAW. ARRIVAL OF DRIER AIR WILL RESULT IN
CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN AND MID TO
LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON APR 21 2014
IN THE WAKE OF A COLD FRONT CURRENTLY PASSING ACROSS LAKE
SUPERIOR...NW WINDS WILL INCREASE TO 15-30KT TONIGHT. STRONGEST
WINDS WILL BE IN A CORRIDOR FROM NCNTRL TO SCNTRL/SE LAKE SUPERIOR
WHERE SOME GALE FORCE GUSTS WILL PROBABLY OCCUR...MOSTLY IN THE
OVERNIGHT/EARLY TUE MORNING TIME PERIOD. THESE STONG WINDS WILL
DIMINISH FROM W TO E TUE INTO TUE EVENING AS A HIGH PRES RIDGE
ARRIVES. WINDS WILL FALL TO UNDER 15KT TUE NIGHT WITH LIGHT WINDS
LINGERING THRU AT LEAST WED MORNING AS HIGH PRES SLOWLY EXITS TO THE
E. OVER WRN LAKE SUPERIOR...NE WINDS WILL BE ON THE INCREASE WED
AFTN. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS
LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...EASTERLY WINDS
WILL BE ON THE INCREASE THU. WINDS WILL THEN BACK AROUND TO THE N
FRI AS THE LOW PASSES ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE
TRACK AND INTENSITY OF THIS LOW...THERE COULD SOME GALE FORCE
WINDS...POSSIBLY OVER WRN LAKE SUPERIOR AHEAD OF THE LOW AND THEN
OVER CNTRL AND ERN LAKE SUPERIOR AS THE LOW PASSES TO THE E.
&&
.HYDROLOGY...
ISSUED AT 1229 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT
RIVER...HARVEY/HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT
HYDE/FRDM4/ ON THE FORD RIVER /WHICH LOOKS TO BE FLUCTUATING DUE TO
ICE JAM ISSUES/.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE
REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER
LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN
FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER
LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS/KC
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 AM EDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON APR 21 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACROSS
THE CNTRL AND ERN CONUS. IN THE NRN STREAM...A VIGOROUS SHORTWAVE
WAS MOVING ACROSS NRN ONTARIO JUST TO THE N OF LAKE SUPERIOR. IN THE
SRN STREAM...ANOTHER WAVE WAS MOVING ACROSS THE MID AND LWR
MISSISSIPPI VALLEY. DESPITE STRENGTH AND PROXIMITY OF NRN STREAM
WAVE...IT`S ONLY BEEN IN THE LAST HR THAT ISOLD -SHRA HAVE MANAGED
TO DEVELOP ALONG ASSOCIATED SFC COLD FRONT WHICH IS RUNNING FROM
NEAR ISLE ROYALE ACROSS THE KEWEENAW AND THEN S THRU IRON COUNTY.
LIMITED COVERAGE IS DUE TO LACK OF INSTABILITY AND THE FACT THAT
DEEP LAYER FORCING WITH WAVE IS PASSING MOSTLY N OF UPPER MI.
OVER THE NEXT SEVERAL HRS...WILL CARRY MAINLY ISOLD -SHRA COVERAGE
ALONG COLD FRONT AS IT SWEEPS E. ATTENTION THEN TURNS TO HEALTHY CAA
AND LOW CLOUD/-FZDZ/DZ POTENTIAL. WITH 850MB TEMPS FALLING TO AROUND
-8C...LAKE EFFECT PCPN WON`T BE A CONCERN TONIGHT INTO TUE MORNING.
HOWEVER...MODELS CONTINUE TO SHOW SIGNIFICANT LOW-LEVEL MOISTENING
TONIGHT WHICH APPEARS ON TRACK GIVEN IFR CIGS THAT WERE OBSERVED
UPSTREAM IN NRN MN/ADJACENT ONTARIO EARLIER TODAY. DAYTIME HEATING
HAS RAISED CIGS...BUT CLOUDS CONTINUE TO HEAD SE EVEN THOUGH SLOWED
BY MIXING OUT OF MOISTURE AT THE LEADING EDGE. ONCE DAYTIME HEATING
DIMINISHES...CLOUDS WILL MAKE A QUICKER RUN TO THE SE INTO UPPER
MI. EXAMINATION OF FCST SOUNDINGS SHOW MOISTURE DEPTH INCREASES TO
800 TO 700MB...AND WITH TEMPS WITHIN THE MOISTURE DEPTH WARMER THAN
-10C...PRESENCE OF ICE CRYSTALS IS UNLIKELY. SO...IF THERE IS ANY
PCPN...PTYPE SHOULD BE JUST -DZ/-FZDZ. HOWEVER...SINCE MODEL TREND
HAS BEEN FOR MOISTURE DEPTH TO BE DEEPER AND CLOSER TO -10C...WILL
INCLUDE A MENTION OF FLURRIES AS WELL. WHILE CONFIDENCE IS NOT
HIGH...WILL CONTINUE WITH LOW POPS FOR -DZ/-FZDZ/FLURRIES
OVERNIGHT THRU TUE MORNING...MAINLY IN THE AREAS WHERE UPSLOPING
OCCURS WITH A NNW WIND. WITH THE BETTER MOISTURE OVER THE E...WILL
NOT MENTION ANY PCPN OVER THE FAR W.
ON TUE...IT APPEARS NOW THAT CLEARING TREND WILL BE SLOWER WITH
850MB TROF FIRMLY OVER THE FCST AREA AT 18Z. ANY LOCATIONS THAT
START THE DAY WITH SOME SUNSHINE WILL SEE CU/STRATOCU RAPIDLY
DEVELOP. DURING THE MID AND LATE AFTN...THE LAKE WILL BECOME A
STABILIZING INFLUENCE...RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKE FIRST. THEN...THE CLEARING WILL SPREAD INLAND. WITH GRADIENT
N/NW WINDS ENHANCED BY LAKE BREEZE...IT WILL BE A BLUSTERY/SHARPLY
COLDER DAY WITH TEMPS 20 TO POSSIBLY AS MUCH AS 30 DEGREES COLDER IN
SOME SPOTS. IT WILL BE ESPECIALLY CHILLY ALONG LAKE SUPERIOR
WHERE TEMPS WON`T GET ABOVE THE MID 30S AT BEST. OVER THE FAR
SCNTRL...TEMPS MAY RISE TO AROUND 50F.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 409 PM EDT MON APR 21 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION ON TUESDAY
WILL LEAD TO A DRY PERIOD FOR TUESDAY NIGHT AND MUCH OF WEDNESDAY.
THERE MAY BE A FEW LINGERING CLOUDS OVER THE FAR EAST TO START THE
EVENING...BUT OTHERWISE EXPECT MOSTLY CLEAR SKIES TUESDAY NIGHT AND
INTO WEDNESDAY ACROSS THE U.P. LOWS ON TUESDAY NIGHT WILL BE BELOW
NORMAL AND IN THE 20S FOR MOST LOCATIONS. DID TREND SOME OF THE
INTERIOR COLD SPOTS IN THE TEENS SINCE THE HIGH WILL BE OVERHEAD
AND PWATS OF 40-45 PERCENT OF NORMAL WOULD SUPPORT GOING AT OR
BELOW MOS GUIDANCE. THE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK
CLOSER TO NORMAL FOR WEDNESDAY. LIGHT WINDS WILL GRADUALLY TURN TO
THE SOUTHEAST DURING THE AFTERNOON...BUT THEY SHOULD BE LIGHT
ENOUGH TO ALLOW LAKE BREEZES TO DEVELOP NEAR THE GREAT LAKES
SHORELINES AND KEEP TEMPERATURES COOLER THERE.
THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH
AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT
LAKES REGION WEDNESDAY NIGHT AND LIKELY CONTINUING INTO SATURDAY.
THIS UPPER TROUGH IS CURRENTLY WEST OF THE PACIFIC NORTHWEST AND
WILL COME ONSHORE TONIGHT. AS THIS SYSTEM CROSSES THE ROCKIES...A
SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN
ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON
THURSDAY. AS THIS OCCURS...BROAD ISENTROPIC ASCENT ON THE 290-305K
SURFACES WILL SPREAD NORTHEAST INTO UPPER MICHIGAN ON WEDNESDAY
NIGHT. THIS FIRST WAVE WILL STEADILY PUSH NORTHEAST THROUGH
THURSDAY...WHILE A SECONDARY WAVE OF PRECIPITATION MOVES IN ON
THURSDAY AHEAD OF THE UPPER TROUGH AXIS MOVES INTO THE UPPER
MISSISSIPPI VALLEY AND NEARS THE UPPER GREAT LAKES. THIS UPPER
TROUGH WILL SHIFT THE HEAVIEST PRECIPITATION OVER THE NORTHERN
HALF OF LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WITH THE
MOISTURE PRESENT AND FORCING FROM THE UPPER TROUGH...WOULD EXPECT
LINGERING LIGHT SHOWERS TO BE ONGOING OVER THE AREA FRIDAY INTO
FRIDAY NIGHT. PRECIPITATION TYPE IS VERY TRICKY AT THIS POINT DUE TO
THE VARYING SOLUTIONS IN THE MODELS WITH THE THERMAL FIELD WEDNESDAY
NIGHT INTO THURSDAY. AS THE INITIAL SURGE OF PRECIP MOVES INTO THE
AREA...IT ENCOUNTERS A ISOTHERMAL LAYER FROM THE SURFACE THROUGH
700MB WITH TEMPERATURES AT OR JUST ABOVE FREEZING. THIS LAYER
REMAINS STEADY THROUGH MUCH OF THURSDAY. AS FOR THE MODELS...THE
12Z GFS HAS TRENDED A LITTLE COOLER COMPARED TO THE PREVIOUS
RUNS...THE 12Z ECMWF REMAINS THE COOLEST AND THE 12Z GEM IS
IN BETWEEN INITIALLY. UNFORTUNATELY IT IS DIFFICULT TO GET TOO
SPECIFIC IN THESE SITUATIONS AS JUST A SLIGHT CHANGE IN TEMPERATURE
BETWEEN 925-700MB OF 1-2C ONE WAY OR ANOTHER CAN MAKE A HUGE
DIFFERENCE IN THE PRECIP TYPE AND ASSOCIATED IMPACTS. THUS...WILL
FOLLOW AN IDEA OF RAIN/SNOW MIX WITH THE INITIAL SURGE OF PRECIP AND
LIKELY TRANSITIONING TO MORE RAIN DURING THE DAY THURSDAY (OVER
THE SOUTH HALF). THE NORTHWARD EXTENT OF THIS TRANSITION IS
UNCERTAIN AT THIS POINT AND WILL PLACE IT OVER THE NORTH HALF OF
LAKE SUPERIOR THURSDAY AFTERNOON/EVENING. COLDER AIR WILL BEGIN TO
SHIFT INTO THE AREA ON THURSDAY NIGHT AS THE LOW SHIFTS EAST ACROSS
UPPER MICHIGAN AND LEAD TO A TRANSITION TO ALL SNOW INTO FRIDAY. BY
THE TIME THE PRECIPITATION WILL START TO TRANSITION TO ALL
SNOW...THE HEAVIEST RATES WILL HAVE DEPARTED THE AREA AND EXPECT
MORE OF A SCATTERED/LIGHT PRECIP TO REMAIN. WILL CONTINUE THE
PREVIOUS SHIFTS IDEA OF THE HIGHEST QPF OVER THE WESTERN HALF OF
THE CWA AND AROUND 0.5-1.0IN THROUGH THURSDAY EVENING. THAT MATCHES
UP WELL WITH SOME OF THE ECMWF/GFS QPF PROBS. AS MENTIONED
EARLIER...SNOW POTENTIAL IS TRICKY BUT THE SLIGHTLY COOLER
TREND SEEN IN THE 12Z MODELS CREATES CONCERN FOR MEASURABLE (AND
POTENTIALLY SIGNIFICANT) SNOWFALL OVER THE KEWEENAW DUE TO ITS
CLOSER PROXIMITY TO THE COLDER AIR TO THE NORTH. FINALLY FOR THIS
SYSTEM...THE COLD AIR AND BREEZING CONDITIONS SURGING IN BEHIND THE
LOW ON FRIDAY AND INTO SATURDAY WILL MAKE IT FEEL MORE LIKE MARCH
ACROSS THE AREA. WIND CHILL VALUES FRIDAY NIGHT AND INTO SATURDAY
WILL BE IN THE TEENS AND 20S WITH THE LOWEST VALUES NEAR LAKE
SUPERIOR.
MODELS DO DIFFER ON HOW QUICKLY THE UPPER TROUGH DEPARTS THIS
WEEKEND...SO THE FORECAST FOR THE END OF THE WEEKEND AND INTO EARLY
NEXT WEEK IS UNCERTAIN. EVEN WITH THIS UNCERTAINTY...THE GENERAL
IDEA OF BELOW NORMAL TEMPERATURES FOR THE WEEKEND AND INTO THE FIRST
PART OF NEXT WEEK SEEMS REASONABLE AS A HUDSON BAY HIGH BECOMES
STATIONARY AND LEADS TO DRY NORTHEASTERLY FLOW. PRECIPITATION
CHANCES WILL DEPEND ON THE NEXT UPPER TROUGH THAT LOOKS TO BE
LOCATED IN THE CENTRAL/SOUTHERN PLAINS AND AT THIS TIME MAY BE FAR
ENOUGH SOUTH TO KEEP THE AREA DRY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 749 PM EDT MON APR 21 2014
GUSTY NW WINDS TO 25 KTS IN THE WAKE OF A COLD FRONT WILL DRAW MUCH
COLDER AIR AS WELL AS LOW CLOUDS INTO THE UPPER LAKES LATE THIS
EVENING AND OVERNIGHT. MVFR CIGS WILL ARRIVE FIRST AT KCMX AND KSAW
CLOSER TO MIDNIGHT AND THEN OVERNIGHT AT KIWD. ARRIVAL OF DRIER AIR
WILL RESULT IN CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY
AFTN AND MID TO LATE AFTERNOON AT KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON APR 21 2014
IN THE WAKE OF A COLD FRONT CURRENTLY PASSING ACROSS LAKE
SUPERIOR...NW WINDS WILL INCREASE TO 15-30KT TONIGHT. STRONGEST
WINDS WILL BE IN A CORRIDOR FROM NCNTRL TO SCNTRL/SE LAKE SUPERIOR
WHERE SOME GALE FORCE GUSTS WILL PROBABLY OCCUR...MOSTLY IN THE
OVERNIGHT/EARLY TUE MORNING TIME PERIOD. THESE STONG WINDS WILL
DIMINISH FROM W TO E TUE INTO TUE EVENING AS A HIGH PRES RIDGE
ARRIVES. WINDS WILL FALL TO UNDER 15KT TUE NIGHT WITH LIGHT WINDS
LINGERING THRU AT LEAST WED MORNING AS HIGH PRES SLOWLY EXITS TO THE
E. OVER WRN LAKE SUPERIOR...NE WINDS WILL BE ON THE INCREASE WED
AFTN. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS
LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...EASTERLY WINDS
WILL BE ON THE INCREASE THU. WINDS WILL THEN BACK AROUND TO THE N
FRI AS THE LOW PASSES ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE
TRACK AND INTENSITY OF THIS LOW...THERE COULD SOME GALE FORCE
WINDS...POSSIBLY OVER WRN LAKE SUPERIOR AHEAD OF THE LOW AND THEN
OVER CNTRL AND ERN LAKE SUPERIOR AS THE LOW PASSES TO THE E.
&&
.HYDROLOGY...
ISSUED AT 1229 AM EDT TUE APR 22 2014
AFTER ANOTHER GOOD DAY OF MELTING ON MONDAY...TODAY WILL BE QUITE A
BIT DIFFERENT. LOOK FOR LITTLE ADDITIONAL MELTING AS HIGHS STRUGGLE
TO RISE PAST THE MID 30S ACROSS MUCH OF THE AREAS THAT STILL HAVE 5
INCHES OR MORE SNOW STILL ON THE GROUND. THIS SHOULD LIMIT
ADDITIONAL RISES ON MANY OF THE AREA RIVERS AND STREAMS. ALTHOUGH
RATHER COOL TEMPERATURES WILL REMAINS...UNSETTLED WEATHER WILL
RETURN THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE
WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW
PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY
FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS
RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW
WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE
FCST AS THE TIME NEARS.
SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN
ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE
ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT
RIVER...HARVEY/HRVM4/ ON THE CHOCOLAY RIVER...AND TO A LESSER EXTENT
HYDE/FRDM4/ ON THE FORD RIVER /WHICH LOOKS TO BE FLUCTUATING DUE TO
ICE JAM ISSUES/.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME
LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE
REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA
COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER
LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN
FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER
LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
325 PM CDT TUE APR 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT TUE APR 22 2014
HIGH PRESSURE OVER THE NORTHLAND WILL BEGIN TO SHIFT TO THE EAST
TONIGHT. CLEAR SKIES AND LIGHT WINDS ARE EXPECTED FOR AT LEAST
TONIGHT, AND FOR ALL OF THE NIGHT ACROSS THE EASTERN FORECAST
AREA. AS FOR THE WESTERN FORECAST AREA, THERE WILL BE INCREASING
HIGH CLOUDS FROM THE WEST AS A LOW PRESSURE SYSTEM DEVELOPS IN THE
NORTHERN HIGH PLAINS. THE CLEAR SKIES AND LIGHT WINDS WILL PROMOTE
RADIATIONAL COOLING. LOW TEMPERATURES SHOULD RANGE FROM THE MID TO
UPPER 20S IN THE EASTERN FORECAST AREA TO THE LOW TO MID 30S
ACROSS THE WESTERN FORECAST AREA. THERE IS THE POSSIBILITY OF FOG
TONIGHT...HOWEVER I AM NOT CONFIDENT AT THIS POINT. THE LOCAL
WRF...NAM...AND RAP MODELS ARE SUGGESTING IT IS POSSIBLE ACROSS
THE EASTERN FORECAST AREA...ESPECIALLY CLOSER TO LAKE SUPERIOR.
THIS IS SOMETHING THE EVENING SHIFT CAN LOOK MORE INTO WHEN IT
MORE HIGH RESOLUTION MODEL DATA IS AVAILABLE.
WEDNESDAY...A DEEP MID/UPPER LEVEL LOW WILL MOVE EAST FROM THE
PACIFIC NW TO NORTHERN MONTANA. SURFACE LOW PRESSURE WILL CONTINUE
TO DEVELOP AND ORGANIZE IN THE PLAINS...AND BEGINNING TO BRING
INCREASING SE FLOW AND MOISTURE TO THE UPPER MIDWEST. THE LOW
LEVEL SE FLOW WILL BEGIN FAIRLY DRY...SO IT WILL LIKELY TAKE SOME
TIME FOR THE LOW LEVELS TO SATURATE BEFORE THE NORTHLAND SEES ANY
SIGNIFICANT RAINFALL. THE GFS IS FASTER THAN OTHER MODELS AT
BRINGING IN THE PCPN INTO THE FORECAST AREA...SO I LEANED MORE ON
THE SREF/NAM/GEM/ECMWF. THE INCREASING CLOUD COVER WILL RESULT IN
COOLER TEMPERATURES FOR MUCH OF THE NORTHLAND COMPARED TO TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE APR 22 2014
THE BIG CONCERN FOR THE LONG TERM IS THE MAJOR STORM SYSTEM THAT
IS EXPECTED TO MOVE THROUGH THE REGION LATE IN THE WEEK. THERE
ARE SOME DISTINCT MODEL DIFFERENCES DURING THIS TIME PERIOD...AS
THE MODELS ATTEMPT TO PHASE TWO LOW PRESSURE SYSTEMS INTO ONE MAIN
LOW OVER THE WESTERN GREAT LAKES. THE UK/EC AND EVEN THE NAM
GENERALLY MAINTAIN TWO DISCRETE LOW AREAS...WITH THE GFS AND GEM
COMPLETELY PHASING THE DUAL LOW ENERGY INTO ONE LOW. THE IMPACT ON
SENSIBLE WEATHER IS NOT SO DRAMATIC...AS ALL OF THE MODELS SUPPORT
FAIRLY HIGH TOTAL QPF. BUT THERE ARE DIFFERENCES IN THE THERMAL
PROFILES AND OF COURSE IN WINDS. OVERALL...WILL BE A LITTLE
CAREFUL ABOUT COMPLETELY PHASING THE TWO SURFACE LOWS...AND
FAVORING A SOLUTION A BIT MORE IN LINE WITH THE ECMWF. OF PERHAPS
THE MOST CONCERN FOR OUR AREA IS THE CHANCE OF ACCUMULATING
SNOWFALL. MODEL RUN SNOW ACCUMULATION VALUES ARE FAIRLY HIGH FOR
NORTHEASTERN MN...ESPECIALLY OVER THE TIP OF THE ARROWHEAD...WHERE
ALL OF THE MODELS BASICALLY SUPPORT THE POTENTIAL FOR MORE THAN 6
INCHES OF SNOW. AFTER COORDINATING WITH HPC AND THE WINTER WEATHER
DESK...THINK THERE IS TIME TO HOLD OFF ON ISSUING A WATCH FOR THE
ARROWHEAD DUE TO DIFFERENCES IN THERMAL PROFILES OF FORECAST
SOUNDINGS...DIFFERENCES IN HOW THE MODELS ARE HANDLING THE PHASING
OF THE TWO LOW STRUCTURE AND QUESTIONS ABOUT THE POTENTIAL FOR
SIGNIFICANT MELTING. SPRING SYSTEMS LIKE THIS ARE NOTORIOUSLY
DIFFICULT THIS FAR OUT...AS SUBTLE CHANGES IN THE THERMAL PROFILES
COULD YIELD DRAMATICALLY DIFFERENT OUTCOMES. AT THIS POINT...NOT
COMFORTABLE ISSUING A WATCH FOR THE ARROWHEAD...BUT IT IS
SOMETHING WE WILL NEED TO WATCH VERY CLOSELY AND MAY EVENTUALLY
NEED A WATCH. FURTHER SOUTH...SOUTH OF THE IRON RANGE...THERE IS
ALSO THE POTENTIAL FOR SOME SNOW ACCUMULATION...BUT IT SHOULD
GENERALLY BE A SLUSH ACCUMULATION OF MAYBE UP TO A COUPLE INCHES.
EVEN FURTHER SOUTH FROM EAST CENTRAL MINNESOTA INTO OUR SOUTHERN
TIER OF COUNTIES...THERE SHOULD BE LITTLE TO NO SNOW ACCUMULATION.
NO MATTER WHAT...IT WILL BE WET AND POTENTIALLY SNOWY END TO THE
WEEK FOR THE CWA. IT SHOULD THEN BE QUIET AND MAINLY DRY FOR THE
WEEKEND. WILL ALSO NEED TO WATCH THE SYSTEM FOR LATE IN THE
WEEKEND...AND EARLY NEXT WORK WEEK...BUT FOR NOW IT LOOKS LIKE IT
MAY NOT TOTALLY GET ITS ACT TOGETHER TO HAVE A MAJOR IMPACT ON OUR
WEATHER. THAT MAY CHANGE AS IT IS QUITE A WAYS OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 110 PM CDT TUE APR 22 2014
VFR CONDITIONS ARE IN STORE FOR THE TAF SITES THROUGHOUT THE
PERIOD. SOME SCATTERED CUMULUS TYPE CLOUDS WILL BE FOUND TODAY
AND HIGH CLOUDS AND SOME MID CLOUDS WILL ADVANCE INTO THE AREA ON
WEDNESDAY MORNING...AHEAD OF THE NEXT MAJOR LOW PRESSURE SYSTEM TO
MOVE INTO THE AREA. SOME RAIN MAY MAKE IT TO KBRD BUT FOR MOST
LOCATIONS IT WILL HOLD OFF UNTIL AFTER THE TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 45 34 43 / 0 20 80 90
INL 30 54 36 45 / 0 10 80 90
BRD 38 49 41 52 / 10 70 90 70
HYR 28 53 38 50 / 0 50 90 90
ASX 27 48 36 47 / 0 10 80 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
338 PM CDT TUE APR 22 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 330 PM CDT TUE APR 22 2014
MAIN FORECAST CONCERN WILL BE CENTERED AROUND THUNDERSTORM CHANCES
THROUGH THURSDAY MORNING.
MID/UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE INTERMOUNTAIN WEST WITH
IMPRESSIVE 130M HEIGHT FALLS OUT AHEAD OF IT. THIS TROUGH WILL
CONTINUE TO MOVE EAST AND AHEAD OF IT...A DEEPENING LEE SIDE SFC
LOW WILL EXTEND ACROSS THE HIGH PLAINS BY 12Z WED. AHEAD OF ALL OF
THIS...STRONG LOW LEVEL SOUTHERLY FLOW WILL BRING BOTH WARM AND
MOIST AIR ADVECTION INTO THE REGION. AN FEW RADAR RETURNS ARE
SHOWING UP UNDER THE ACCAS FIELD OVER CENTRAL NEBRASKA THIS
AFTERNOON. THE HRRR HAS PICKED UP ON THIS BUT WITH LITTLE UPPER
LEVEL SUPPORT IN THE AREA JUST YET...THINK THESE WILL FADE AS
THEY APPROACH A MUCH DRIER AIRMASS THIS EVENING. NOCTURNAL 850MB
WINDS ON THE ORDER OF 50-60KTS ARE FORECAST OVERNIGHT WHICH WILL
HELP ADVECT +8 TO +10C DEWPOINTS INTO THE AREA BY WED AFTERNOON.
WILL CONTINUE OVERNIGHT/EARLY MORNING TSTM CHANCES IN ASSOCIATION
WITH THE STRENGTHENING LLVL JET. A TIGHTENING SURFACE PRESSURE
GRADIENT BETWEEN THE RETREATING HIGH PRESSURE CURRENTLY OVERHEAD
NOW AND THE APPROACHING HIGH PLAINS LOW WILL BRING QUITE GUSTY
WINDS TO THE AREA WED MORNING AND THROUGH THE EARLY AFTERNOON.
WITH COORDINATION FROM SURROUNDING OFFICES...WILL HOIST A WIND
ADVISORY FOR PORTIONS OF OUR WEST AND NORTH FROM 15-21Z.
EXPECT A LULL IN TSTM ACTIVITY DURING THE LATE MORNING/EARLY
AFTERNOON HOURS WEDNESDAY. THE SFC LOW WILL BE ENTERING INTO
WESTERN KANSAS BY 00Z THU WITH COLD FRONT PUSHING THROUGH CENTRAL
NEBRASKA. THE GREATEST INSTABILITY WILL EXIST OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA AT THIS TIME WITH BULK 0-6KM
SHEAR ON THE ORDER OF 50KTS. CONVECTION IS LIKELY TO DEVELOP
ALONG/AHEAD OF THE COLD FRONT AND SPREAD EAST THROUGH THE LATE
AFTERNOON AND EARLY EVENING HOURS WITH LARGE HAIL AND DAMAGING
WINDS AS THE PRIMARY HAZARDS. PW`S BY EARLY EVENING DO INCREASE TO
AROUND 1.50" SO THE POTENTIAL EXISTS FOR SOME HEAVIER RAINFALL
AMOUNTS.
THE UPPER TROUGH IS FORECAST TO SWING THROUGH CENTRAL NEB BY 12Z
THURSDAY WITH THE SFC COLD FRONT WELL INTO IOWA BY THAT TIME.
LINGERING POST FRONTAL PCPN IS QUITE POSSIBLE IN OUR EASTERN
COUNTIES IN THE MORNING.
BROAD/WEAK UPPER RIDGING WILL MOVE OVERHEAD ON FRIDAY WITH STRONG
SOUTHERLY FLOW SO WE SHOULD BE ABLE TO WARM INTO THE LOW 70S
FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CDT TUE APR 22 2014
GLOBAL MODELS ARE CONSISTENT IN MOVING A TROUGH ACROSS THE ROCKIES
AND INTO THE CENTRAL PLAINS THIS WEEKEND. THE MODELS DIVERGE TO SOME
DEGREE AS TO HOW QUICKLY TO MOVE THE TROUGH OUT OF THE AREA WITH
LITTLE IN THE WAY OF AN UPSTREAM KICKER. THE 00Z ECMWF IS HOLDING
ONTO THIS TROUGH INTO THE DAY ON MONDAY AS THE SLOWEST SOLUTION.
AHEAD OF THE SYSTEM MODIFIED GULF AIR WILL BE ADVANCING NORTHWARD ON
SATURDAY. MOST OF THE DAY ON SATURDAY SHOULD BE DRY BUT A COLD FRONT
WILL MOVE INTO NORTHEAST NEBRASKA BY AFTERNOON AND THIS COULD BE THE
IMPETUS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BY AFTERNOON.
AS LARGER-SCALE FORCING INCREASES ON SATURDAY NIGHT...ALONG WITH
STRONGER LOW LEVEL WARM-AIR ADVECTION WE SHOULD SEE AN INCREASE IN
THE AREAL EXTENT OF THE PRECIP...AND LIKELY POPS APPEAR WARRANTED AT
THIS TIME. THE 00Z GFS/GEM WOULD THEN SHIFT THIS FORCING/PRECIP
SOUTH OF THE AREA BY SUNDAY NIGHT WHILE THE ECMWF WOULD CONTINUE
SOME THREAT INTO MONDAY. ALTHOUGH THE SLOWER SOLUTION OF THE ECMWF
ISN`T OUT OF THE QUESTION...GIVEN THE LIMITED SUPPORT WILL CONT WITH
A DRY FORECAST FOR SUNDAY NIGHT THROUGH TUESDAY.
TEMPERATURES WILL WARM INTO THE 70S FOR MOST AREAS ON SATURDAY AHEAD
OF THE COLD FRONT...BUT WITH THE PRECIP AND CAA ON SUNDAY
TEMPERATURES WILL LIKELY HOLD IN THE 60S. TEMPERATURES SHOULD BE ON
THE INCREASE FOR MON/TUE AS A WESTERN US RIDGE DEVELOPS EAST INTO
THE CENTRAL US.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1212 PM CDT TUE APR 22 2014
GENERALLY LOOK FOR VFR CONDITIONS THROUGH THE PERIOD. CEILINGS
MAINLY ABOVE 5000 FEET COULD DEVELOP LATER TONIGHT WITH -SHRA
ACTIVITY. DID NOT MENTION -TSRA IN TAFS FOR NOW...SINCE COVERAGE
MAY BE LIMITED. DECIDED TO ADD IN LOW LEVEL WIND SHEAR FOR TONIGHT
AS WINDS ALOFT BELOW 2000 FEET INCREASE INTO THE 40 TO 50 KNOT
RANGE OR MORE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR NEZ011-012-
015>018-030>034-042>044-050-051-065-066-078-088-089.
IA...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR IAZ043.
&&
$$
SHORT TERM...KERN
LONG TERM...MILLER
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1212 PM CDT TUE APR 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
INITIAL CONCERN WILL BE DEWPOINTS FOR THIS AFTERNOON THEN
THUNDERSTORMS FOR WEDNESDAY AFTERNOON INTO THURSDAY MORNING.
HIGH PRESSURE CENTERED OVER THE NEBRASKA IOWA BORDER AT 07Z
WILL MOVE EAST INTO THE MISSISSIPPI VALLEY BY THIS EVENING.
SOUTH WINDS WILL BE INCREASING OVER THE AREA TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND AN
AREA OF LOW PRESSURE MOVING OUT OF THE NORTHERN ROCKIES.
MAIN UNCERTAINTY WILL BE WITH AMOUNT OF DRYING AT THE SURFACE AS
THE WINDS INCREASE AND IMPACT ON FIRE WEATHER CONDITIONS TODAY.
MOS GUIDANCE CONSIDERABLY HIGHER WITH DEWPOINTS COMPARED TO RAP
MODEL. SINCE MOS HAS HAD A TENDENCY TO OVERDUE THE MOISTURE
DECIDED TO GO WITH A BLEND OF THE RAP AND ALLBLEND. THIS GIVES
RH VALUES JUST ABOVE CRITERIA FOR RFW THIS AFTERNOON AND PLAN
ON ADDRESSING VERY HIGH FIRE WEATHER INDEX IN HWO FOR NOW.
LOW LEVEL MOISTURE INCREASES OVER THE REGION TONIGHT AS THE
NORTHERN ROCKIES LOW MOVES ONTO THE HIGH PLAINS WITH CHANCE POPS
FOR THE FORECAST AREA AFTER MIDNIGHT AS MID LEVEL WARM ADVECTION
AND SHORT WAVE ENERGY MOVE INTO THE AREA. POPS INCREASE TO LIKELY
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS THE COLD FRONT HELPS
TO ENHANCE CONVECTION. OPERATIONAL MODELS ALL INDICATE HEAVY RAIN
POTENTIAL WITH THE STORMS ALONG THE FRONT LATE WEDNESDAY AFTERNOON
INTO WEDNESDAY EVENING. LINGERING SHOWERS ON THE BACK SIDE OF THE
FRONT HANG AROUND IN THE EAST INTO EARLY THURSDAY MORNING THEN
CLEAR RAPIDLY THROUGH THE REST OF THE MORNING. DRY WEATHER AFTER
THAT INTO FRIDAY WITH SEASONAL TEMPERATURES.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
RAIN CHANCES RETURN FOR THE WEEKEND IN THE EXTENDED PERIOD AS
ANOTHER STRONG UPPER WAVE COMES INTO THE INTERMOUNTAIN WEST ON
SATURDAY WITH A WARM FRONT SETTING UP AT THE SURFACE ACROSS
KANSAS. SYSTEM LIFTS NORTHEAST ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY WITH STRONG DYNAMICS AND ABUNDANT MOISTURE INDICATED BY
BOTH THE GFS AND ECMWF. MAIN DIFFERENCE BETWEEN THE MODELS IS
THAT THE GFS CLOSES OFF THE SYSTEM SOONER AND FURTHER SOUTH THAN
THE EURO. EITHER WAY BOTH MODELS KEEP SHOWERS AND STORMS AROUND
EARLY NEXT WEEK.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1212 PM CDT TUE APR 22 2014
GENERALLY LOOK FOR VFR CONDTIONS THROUGH THE PERIOD. CEILINGS
MAINLY ABOVE 5000 FEET COULD DEVELOP LATER TONIGHT WITH -SHRA
ACTIVITY. DID NOT MENTION -TSRA IN TAFS FOR NOW...SINCE COVERAGE
MAY BE LIMITED. DECIDED TO ADD IN LOW LEVEL WIND SHEAR FOR TONIGHT
AS WINDS ALOFT BELOW 2000 FEET INCREASE INTO THE 40 TO 50 KNOT
RANGE OR MORE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
607 AM CDT TUE APR 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
INITIAL CONCERN WILL BE DEWPOINTS FOR THIS AFTERNOON THEN
THUNDERSTORMS FOR WEDNESDAY AFTERNOON INTO THURSDAY MORNING.
HIGH PRESSURE CENTERED OVER THE NEBRASKA IOWA BORDER AT 07Z
WILL MOVE EAST INTO THE MISSISSIPPI VALLEY BY THIS EVENING.
SOUTH WINDS WILL BE INCREASING OVER THE AREA TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND AN
AREA OF LOW PRESSURE MOVING OUT OF THE NORTHERN ROCKIES.
MAIN UNCERTAINTY WILL BE WITH AMOUNT OF DRYING AT THE SURFACE AS
THE WINDS INCREASE AND IMPACT ON FIRE WEATHER CONDITIONS TODAY.
MOS GUIDANCE CONSIDERABLY HIGHER WITH DEWPOINTS COMPARED TO RAP
MODEL. SINCE MOS HAS HAD A TENDENCY TO OVERDUE THE MOISTURE
DECIDED TO GO WITH A BLEND OF THE RAP AND ALLBLEND. THIS GIVES
RH VALUES JUST ABOVE CRITERIA FOR RFW THIS AFTERNOON AND PLAN
ON ADDRESSING VERY HIGH FIRE WEATHER INDEX IN HWO FOR NOW.
LOW LEVEL MOISTURE INCREASES OVER THE REGION TONIGHT AS THE
NORTHERN ROCKIES LOW MOVES ONTO THE HIGH PLAINS WITH CHANCE POPS
FOR THE FORECAST AREA AFTER MIDNIGHT AS MID LEVEL WARM ADVECTION
AND SHORT WAVE ENERGY MOVE INTO THE AREA. POPS INCREASE TO LIKELY
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS THE COLD FRONT HELPS
TO ENHANCE CONVECTION. OPERATIONAL MODELS ALL INDICATE HEAVY RAIN
POTENTIAL WITH THE STORMS ALONG THE FRONT LATE WEDNESDAY AFTERNOON
INTO WEDNESDAY EVENING. LINGERING SHOWERS ON THE BACK SIDE OF THE
FRONT HANG AROUND IN THE EAST INTO EARLY THURSDAY MORNING THEN
CLEAR RAPIDLY THROUGH THE REST OF THE MORNING. DRY WEATHER AFTER
THAT INTO FRIDAY WITH SEASONAL TEMPERATURES.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
RAIN CHANCES RETURN FOR THE WEEKEND IN THE EXTENDED PERIOD AS
ANOTHER STRONG UPPER WAVE COMES INTO THE INTERMOUNTAIN WEST ON
SATURDAY WITH A WARM FRONT SETTING UP AT THE SURFACE ACROSS
KANSAS. SYSTEM LIFTS NORTHEAST ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY WITH STRONG DYNAMICS AND ABUNDANT MOISTURE INDICATED BY
BOTH THE GFS AND ECMWF. MAIN DIFFERENCE BETWEEN THE MODELS IS
THAT THE GFS CLOSES OFF THE SYSTEM SOONER AND FURTHER SOUTH THAN
THE EURO. EITHER WAY BOTH MODELS KEEP SHOWERS AND STORMS AROUND
EARLY NEXT WEEK.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 602 AM CDT TUE APR 22 2014
VFR CONDITIONS PREVAIL THROUGH THE PERIOD. LIGHT AND VARIABLE
WINDS AT TAF ISSUANCE...BECOMING SOUTHEAST AROUND 140-160 DEGREES.
WIND SPEEDS INCREASE TO AROUND 13 KNOTS AT KOFK BY 17Z WITH GUSTS
UP TO 21 KNOTS. WIND SPEEDS INCREASE TO 10 TO 12 KNOTS AT KOMA/KLNK
BY 15-20Z. COULD ALSO SEE SCATTERED SHOWERS DEVELOP BY 06Z AT KOFK...
AND 08Z AT KLNK/KOMA. THERE IS SOME ELEVATED INSTABILITY...WHICH
COULD RESULT IN ISOLATED THUNDER AS WELL...BUT TOO FAR OUT TO
PREDICT WITH CERTAINTY. LOW LEVEL WIND SHEAR WILL ALSO BE A
CONCERN AT ALL TAF SITES 06-12Z AS WELL...BUT AGAIN...TOO FAR OUT
TO MENTION IN THE FORECAST AT THIS TIME.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
308 AM CDT TUE APR 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
INITIAL CONCERN WILL BE DEWPOINTS FOR THIS AFTERNOON THEN
THUNDERSTORMS FOR WEDNESDAY AFTERNOON INTO THURSDAY MORNING.
HIGH PRESSURE CENTERED OVER THE NEBRASKA IOWA BORDER AT 07Z
WILL MOVE EAST INTO THE MISSISSIPPI VALLEY BY THIS EVENING.
SOUTH WINDS WILL BE INCREASING OVER THE AREA TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND AN
AREA OF LOW PRESSURE MOVING OUT OF THE NORTHERN ROCKIES.
MAIN UNCERTAINTY WILL BE WITH AMOUNT OF DRYING AT THE SURFACE AS
THE WINDS INCREASE AND IMPACT ON FIRE WEATHER CONDITIONS TODAY.
MOS GUIDANCE CONSIDERABLY HIGHER WITH DEWPOINTS COMPARED TO RAP
MODEL. SINCE MOS HAS HAD A TENDENCY TO OVERDUE THE MOISTURE
DECIDED TO GO WITH A BLEND OF THE RAP AND ALLBLEND. THIS GIVES
RH VALUES JUST ABOVE CRITERIA FOR RFW THIS AFTERNOON AND PLAN
ON ADDRESSING VERY HIGH FIRE WEATHER INDEX IN HWO FOR NOW.
LOW LEVEL MOISTURE INCREASES OVER THE REGION TONIGHT AS THE
NORTHERN ROCKIES LOW MOVES ONTO THE HIGH PLAINS WITH CHANCE POPS
FOR THE FORECAST AREA AFTER MIDNIGHT AS MID LEVEL WARM ADVECTION
AND SHORT WAVE ENERGY MOVE INTO THE AREA. POPS INCREASE TO LIKELY
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AS THE COLD FRONT HELPS
TO ENHANCE CONVECTION. OPERATIONAL MODELS ALL INDICATE HEAVY RAIN
POTENTIAL WITH THE STORMS ALONG THE FRONT LATE WEDNESDAY AFTERNOON
INTO WEDNESDAY EVENING. LINGERING SHOWERS ON THE BACK SIDE OF THE
FRONT HANG AROUND IN THE EAST INTO EARLY THURSDAY MORNING THEN
CLEAR RAPIDLY THROUGH THE REST OF THE MORNING. DRY WEATHER AFTER
THAT INTO FRIDAY WITH SEASONAL TEMPERATURES.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 217 AM CDT TUE APR 22 2014
RAIN CHANCES RETURN FOR THE WEEKEND IN THE EXTENDED PERIOD AS
ANOTHER STRONG UPPER WAVE COMES INTO THE INTERMOUNTAIN WEST ON
SATURDAY WITH A WARM FRONT SETTING UP AT THE SURFACE ACROSS
KANSAS. SYSTEM LIFTS NORTHEAST ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY WITH STRONG DYNAMICS AND ABUNDANT MOISTURE INDICATED BY
BOTH THE GFS AND ECMWF. MAIN DIFFERENCE BETWEEN THE MODELS IS
THAT THE GFS CLOSES OFF THE SYSTEM SOONER AND FURTHER SOUTH THAN
THE EURO. EITHER WAY BOTH MODELS KEEP SHOWERS AND STORMS AROUND
EARLY NEXT WEEK.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1149 PM CDT MON APR 21 2014
VFR CONDITIONS WILL PREVAIL THRU THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1025 PM EDT WED APR 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD INTO THE NORTH COUNTRY BY THURSDAY
WITH CLEARING SKIES AND NEAR NORMAL TEMPERATURES EXPECTED. THE NEXT
CHANCE FOR SHOWERS WILL BE FRIDAY NIGHT INTO SATURDAY ALONG WITH THE
ARRIVAL OF COOLER AIR FOR THE WEEKEND. A FEW MOUNTAINS SNOW SHOWERS
WILL BE POSSIBLE ON SATURDAY NIGHT AND AGAIN ON SUNDAY NIGHT...BUT
ONLY MINOR ACCUMULATION ANTICIPATED.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 1020 PM EDT WEDNESDAY...GOING FORECAST REMAINS IN GOOD
SHAPE. ONLY MINOR CHANGES WITH LATEST UPDATE...MAINLY TO KEEP
FORECAST CURRENT BY INPUTTING LATEST OBSERVATIONAL DATA INTO GRIDS.
WE REMAIN UNDER INFLUENCE OF UPPER TROUGH...WITH CYCLONIC
NORTHWEST FLOW CONTINUING. CLEARING LINE INTO THE SAINT LAWRENCE
VALLEY AT THIS TIME. EXPECT IT TO ADVANCE SLOWLY EASTWARD
OVERNIGHT. SLOWED CLEARING A BIT FROM ADIRONDACKS EASTWARD
BASED ON LATEST TRENDS. THE THREAT OF ANY RAIN/SNOW SHOWERS WILL
COME TO AN END ACROSS NORTHERN NEW YORK...BUT CHANCES CONTINUE
ACROSS NORTHERN GREEN MOUNTAINS AS FORECAST INDICATES. ANY PCPN
AMOUNTS ON THE LIGHT SIDE. NO CHANGES TO MIN TEMP FORECASTS FOR
TONIGHT. LOOK FOR LOWS MAINLY IN THE LOWER TO MID 30S...EXCEPT 20S
IN ADIRONDACKS.
EARLIER DISCUSSION...
WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS THE NE CONUS SLOWLY
LIFTING TWD EASTERN CANADA OVERNIGHT...WITH LARGE AREA OF
SUBSIDENCE DEVELOPING ACRS THE CENTRAL GREAT LAKES. THIS WL SLOWLY
MOVE TWD OUR REGION AFT MIDNIGHT WITH SOME CLRING ACRS OUR WESTERN
CWA. MEANWHILE...THE COMBINATION OF CYCLONIC FLW AND EMBEDDED 5H
VORTS WL RESULT IN SOME LIGHT RAIN/SNOW SHOWERS ACRS THE MTNS
TONIGHT. WL USE THE BTV 4KM AND RAP 13 TO HIGHLIGHT UPSLOPE PRECIP
THIS EVENING...BUT OVERALL QPF/SNOWFALL WL BE LIGHT WITH ONLY
ACCUMULATION ABOVE 2000 FT. THINKING QPF WL BE A COUPLE HUNDREDTHS
OF AN INCH AT BEST. WL MENTION CHC TO LIKELY POPS ACRS THE
NORTHERN DACKS AND NORTHERN/CENTRAL GREEN MTNS IN VT THRU
06Z...THEN TAPER OFF TWD MORNING. SOUNDINGS SHOW GOOD MIXING
TONIGHT AND PLENTY OF LEFTOVER RH BTWN SFC AND 700MB RESULTING IN
LOTS OF CLOUDS...SO THINKING LOWS WL RANGE FROM UPPER 20S MTNS/SLK
TO M/U 30S WARMER VALLEYS. I REALIZE GUIDANCE FOR SLK IS AROUND
20F...BUT THIS SEEMS WAY TOO COLD BASED ON CLOUDS/WINDS...AND CRNT
SFC DWPTS IN THE M30S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 340 PM EDT WEDNESDAY...MAIN FCST CONCERNS WL BE FIRE WX
RELATED ON THURSDAY...FOLLOWED BY ARRIVAL OF PRECIP LATE FRIDAY.
SEE FIRE WX SECTION BELOW FOR DETAILS REGARDING WINDS/RH`S AND
RECENT DRY SPELL ACRS PARTS OF THE REGION. THE COMBINATION OF
DEPARTING SFC LOW PRES AND BUILDING HIGH PRES WL RESULT IN BREEZY
TO GUSTY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH LOCALIZED
GUSTY TO 35 MPH. SOUNDINGS SHOW TOP OF THE MIXED LAYER AROUND 35
KNOTS ON THURSDAY WITH BOTTOM LAYER WINDS AROUND 30
KNOTS...SUPPORTING THIS GUSTY WINDS. STILL THINKING SOME CLOUDS WL
LINGER ACRS THE NORTHERN/CENTRAL MTNS OF VT...INCLUDING THE NEK ON
THURS...BUT CLRING SKIES WL DEVELOP BY MIDDAY ASSOCIATED WITH SFC
HIGH PRES. PROGGED 85H TEMPS BTWN -2C AND -4C...SUPPORT HIGHS ONLY
IN THE M/U 40S MTNS TO L/M50S WARMER VALLEYS ON THURSDAY. THE
COMBINATION OF CLR SKIES AND CALM WINDS WITH SFC HIGH PRES
OVERHEAD WL RESULT IN COOL TEMPS THURS NIGHT. LOWS WL RANGE IN THE
20S COLDER MTN VALLEYS TO L/M 30S WARMER/WIDER CPV/SLV VALLEYS.
MID/UPPER LVL RIDGE BREAKS DOWN ON FRIDAY INTO FRIDAY NIGHT WITH
NEXT SYSTEM APPROACHING THE NE CONUS. FEEL INITIAL S/W ENERGY AND
ASSOCIATED RIBBON OF 850 TO 500MB RH WL DISSIPATE AS IT ENCOUNTER
RIDGE/DRY AIR ACRS OUR REGION. WL MENTION LOW CHC POPS LATE FRIDAY
AFTN ACRS OUR WESTERN CWA AND INCREASE POPS OVERNIGHT AHEAD OF
BETTER DYNAMICS. TEMPS WL WARM TO NEAR NORMAL ON FRIDAY AND STAY
MAINLY IN THE 40S FRIDAY NIGHT WITH THE CLOUDS AND DEVELOPING
SOUTHERLY WINDS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 PM EDT WEDNESDAY...LOOKING AT UNSETTLED WEATHER FOR THE
UPCOMING WEEKEND AS UPPER LEVEL LOW PRESSURE MOVING THROUGH THE
GREAT LAKES FRIDAY NIGHT CLOSES OFF OVER THE NORTH COUNTRY
SATURDAY MORNING...AND SHIFTS OFFSHORE SUNDAY AFTERNOON. THE
RESULT WILL BE PERIODS OF SHOWERS THROUGH SATURDAY NIGHT...WITH
CLOUDY...COOL AND BRISK CONDITIONS FOR SUNDAY. THEREAFTER...BLOCKING
PATTERN LOOKS TO SETUP ACROSS THE CONUS WITH AFOREMENTIONED CLOSED
LOW STALLING OFF THE EASTERN SEABOARD... ANOTHER CLOSED LOW
DEVELOPING OVER THE CENTRAL ROCKIES...AND A HIGHLY AMPLIFIED RIDGE
IN-BETWEEN. WHILE WE SHOULD SEE GENERALLY DRY CONDITIONS THROUGH
THIS PERIOD FOR NEXT MONDAY THROUGH WEDNESDAY AS THE ENTIRE SETUP
SLOWLY SHIFTS EASTWARD...IF AND WHEN THE RIDGE BREAKS DOWN THE
POTENTIAL EXISTS FOR A MULTI- DAY RAIN EVENT AS THE ROCKIES LOW
SHIFTS EAST AND TAPS INTO RICH GULF MOISTURE. TEMPS WILL BE
GENERALLY NEAR NORMAL WITH HIGHS IN THE 50S AND LOWS IN THE 30S
AND 40S.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
THROUGH 00Z FRIDAY...BKN/OVC VFR CEILINGS AND VISIBILITIES TO PREVAIL
THROUGH EARLY MORNING THURSDAY BEFORE CEILINGS SCATTER OUT LATER
IN THE DAY. SUSTAINED NORTH WINDS 10-12 KTS WITH 20-28 KT GUSTS
DROPPING OFF OVER THE NEXT COUPLE OF HOURS. HOWEVER...ANTICIPATE
GUSTS TO PICK BACK UP AGAIN BY AROUND 12-14Z AS MIXING COMMENCES.
OUTLOOK 00Z FRIDAY THROUGH MONDAY...
00Z FRI THRU 00Z SAT...VFR UNDER HIGH PRESSURE. CONTINUED GUSTS FROM
THE NW 00Z THRU 12Z FRI.
00Z SAT THRU 00Z MON...MAINLY VFR WITH CHANCE OF MVFR SHOWERS
ASSOCIATED WITH A WEAK LOW PASSAGE.
MONDAY...MAINLY VFR UNDER SCT-BKN SKIES.
&&
.FIRE WEATHER...
FIRE WEATHER CONCERNS INCREASE ON THURSDAY FOR ELEVATIONS BELOW
1500 FEET ACROSS SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT
DRY SPELL...EXPECTED BREEZY WINDS...AND LOW MIN RH VALUES.
THE LAST MEASURABLE PRECIP AT SPRINGFIELD VT ASOS WAS
4/15/14...WHEN 0.70" OCCURRED...SINCE THEN ONLY A TRACE OF PRECIP
HAS BEEN OBSERVED. SIMILAR CONDITIONS HAVE BEEN NOTED AT
RUTLAND AWOS SITE. THIS HAS RESULTED IN SIGNIFICANT DRYING OF THE
FINE FUELS PER LOCAL FOREST CONTACTS BELOW 1500 FEET...WHERE GREEN
UP HAS NOT OCCURRED. MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE
FUELS AND LEAF LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL
WET. MOST OF CENTRAL/NORTHERN VT MTNS AND PARTS OF NORTHERN NY
HAVE RECEIVED MEASURABLE PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW
PACK IS STILL ON THE GROUND ABOVE 2000 FEET...RESULTING IN LIMITED
THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
30 MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY ON THURSDAY. IN ADDITION...MIN AFTN RH
VALUES WL DROP BTWN 25% AND 35% BTWN 1 PM AND 5PM ON THURSDAY ACRS
THIS AREA...WITH ISOLATED READINGS OF 20% NEAR SPRINGFIELD VT
POSSIBLE.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL AND
YOU WILL WANT TO PAY CLOSE ATTENTION TO ANY OUTDOOR BURNING YOU MAY
BE ATTEMPTING ON THURSDAY. MONITOR WEATHER CONDITIONS...DO NOT LEAVE
YOUR BRUSH OR DEBRIS PILE UNATTENDED...AND HEED ANY ADVICE FROM YOUR
LOCAL FIRE WARDEN.
GIVEN THE SMALL GEOGRAPHICAL AREA WITH FAVORABLE FUEL CONDITIONS AND
MARGINAL FIRE WEATHER PARAMETERS...NO FIRE WEATHER WATCH WILL BE
ISSUED WITH THIS PACKAGE...BUT WILL HIGHLIGHT IN HWO PRODUCT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...RJS/TABER
SHORT TERM...TABER
LONG TERM...LAHIFF
AVIATION...LAHIFF/LOCONTO
FIRE WEATHER...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
734 PM EDT WED APR 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD INTO THE NORTH COUNTRY BY THURSDAY
WITH CLEARING SKIES AND NEAR NORMAL TEMPERATURES EXPECTED. THE NEXT
CHANCE FOR SHOWERS WILL BE FRIDAY NIGHT INTO SATURDAY ALONG WITH THE
ARRIVAL OF COOLER AIR FOR THE WEEKEND. A FEW MOUNTAINS SNOW SHOWERS
WILL BE POSSIBLE ON SATURDAY NIGHT AND AGAIN ON SUNDAY NIGHT...BUT
ONLY MINOR ACCUMULATION ANTICIPATED.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 725 PM EDT WEDNESDAY...GOING FORECAST IN GOOD SHAPE. ONLY
MINOR CHANGES WITH LATEST UPDATE...MAINLY TO INPUT LATEST
OBSERVATIONAL DATA INTO GRIDS. WE REMAIN UNDER INFLUENCE OF UPPER
TROUGH...WITH CYCLONIC NORTHWEST FLOW CONTINUING. CLEARING LINE
APPROACHING SAINT LAWRENCE VALLEY AT THIS TIME. EXPECT IT TO
ADVANCE SLOWLY EASTWARD TONIGHT...WITH THREAT OF ANY RAIN/SNOW
SHOWERS COMING TO AN END ACROSS NORTHERN NEW YORK...BUT CHANCES
CONTINUING ACROSS NORTHERN GREEN MOUNTAINS AS FORECAST INDICATES.
ANY PCPN AMOUNTS ON THE LIGHT SIDE. NO CHANGES TO TEMP FORECASTS
FOR THE OVERNIGHT.
PREVIOUS DISCUSSION...
WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS THE NE CONUS SLOWLY
LIFTING TWD EASTERN CANADA OVERNIGHT...WITH LARGE AREA OF
SUBSIDENCE DEVELOPING ACRS THE CENTRAL GREAT LAKES. THIS WL SLOWLY
MOVE TWD OUR REGION AFT MIDNIGHT WITH SOME CLRING ACRS OUR WESTERN
CWA. MEANWHILE...THE COMBINATION OF CYCLONIC FLW AND EMBEDDED 5H
VORTS WL RESULT IN SOME LIGHT RAIN/SNOW SHOWERS ACRS THE MTNS
TONIGHT. WL USE THE BTV 4KM AND RAP 13 TO HIGHLIGHT UPSLOPE PRECIP
THIS EVENING...BUT OVERALL QPF/SNOWFALL WL BE LIGHT WITH ONLY
ACCUMULATION ABOVE 2000 FT. THINKING QPF WL BE A COUPLE HUNDREDTHS
OF AN INCH AT BEST. WL MENTION CHC TO LIKELY POPS ACRS THE
NORTHERN DACKS AND NORTHERN/CENTRAL GREEN MTNS IN VT THRU
06Z...THEN TAPER OFF TWD MORNING. SOUNDINGS SHOW GOOD MIXING
TONIGHT AND PLENTY OF LEFTOVER RH BTWN SFC AND 700MB RESULTING IN
LOTS OF CLOUDS...SO THINKING LOWS WL RANGE FROM UPPER 20S MTNS/SLK
TO M/U 30S WARMER VALLEYS. I REALIZE GUIDANCE FOR SLK IS AROUND
20F...BUT THIS SEEMS WAY TOO COLD BASED ON CLOUDS/WINDS...AND CRNT
SFC DWPTS IN THE M30S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 340 PM EDT WEDNESDAY...MAIN FCST CONCERNS WL BE FIRE WX
RELATED ON THURSDAY...FOLLOWED BY ARRIVAL OF PRECIP LATE FRIDAY.
SEE FIRE WX SECTION BELOW FOR DETAILS REGARDING WINDS/RH`S AND
RECENT DRY SPELL ACRS PARTS OF THE REGION. THE COMBINATION OF
DEPARTING SFC LOW PRES AND BUILDING HIGH PRES WL RESULT IN BREEZY
TO GUSTY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH LOCALIZED
GUSTY TO 35 MPH. SOUNDINGS SHOW TOP OF THE MIXED LAYER AROUND 35
KNOTS ON THURSDAY WITH BOTTOM LAYER WINDS AROUND 30
KNOTS...SUPPORTING THIS GUSTY WINDS. STILL THINKING SOME CLOUDS WL
LINGER ACRS THE NORTHERN/CENTRAL MTNS OF VT...INCLUDING THE NEK ON
THURS...BUT CLRING SKIES WL DEVELOP BY MIDDAY ASSOCIATED WITH SFC
HIGH PRES. PROGGED 85H TEMPS BTWN -2C AND -4C...SUPPORT HIGHS ONLY
IN THE M/U 40S MTNS TO L/M50S WARMER VALLEYS ON THURSDAY. THE
COMBINATION OF CLR SKIES AND CALM WINDS WITH SFC HIGH PRES
OVERHEAD WL RESULT IN COOL TEMPS THURS NIGHT. LOWS WL RANGE IN THE
20S COLDER MTN VALLEYS TO L/M 30S WARMER/WIDER CPV/SLV VALLEYS.
MID/UPPER LVL RIDGE BREAKS DOWN ON FRIDAY INTO FRIDAY NIGHT WITH
NEXT SYSTEM APPROACHING THE NE CONUS. FEEL INITIAL S/W ENERGY AND
ASSOCIATED RIBBON OF 850 TO 500MB RH WL DISSIPATE AS IT ENCOUNTER
RIDGE/DRY AIR ACRS OUR REGION. WL MENTION LOW CHC POPS LATE FRIDAY
AFTN ACRS OUR WESTERN CWA AND INCREASE POPS OVERNIGHT AHEAD OF
BETTER DYNAMICS. TEMPS WL WARM TO NEAR NORMAL ON FRIDAY AND STAY
MAINLY IN THE 40S FRIDAY NIGHT WITH THE CLOUDS AND DEVELOPING
SOUTHERLY WINDS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 PM EDT WEDNESDAY...LOOKING AT UNSETTLED WEATHER FOR THE
UPCOMING WEEKEND AS UPPER LEVEL LOW PRESSURE MOVING THROUGH THE
GREAT LAKES FRIDAY NIGHT CLOSES OFF OVER THE NORTH COUNTRY
SATURDAY MORNING...AND SHIFTS OFFSHORE SUNDAY AFTERNOON. THE
RESULT WILL BE PERIODS OF SHOWERS THROUGH SATURDAY NIGHT...WITH
CLOUDY...COOL AND BRISK CONDITIONS FOR SUNDAY. THEREAFTER...BLOCKING
PATTERN LOOKS TO SETUP ACROSS THE CONUS WITH AFOREMENTIONED CLOSED
LOW STALLING OFF THE EASTERN SEABOARD... ANOTHER CLOSED LOW
DEVELOPING OVER THE CENTRAL ROCKIES...AND A HIGHLY AMPLIFIED RIDGE
IN-BETWEEN. WHILE WE SHOULD SEE GENERALLY DRY CONDITIONS THROUGH
THIS PERIOD FOR NEXT MONDAY THROUGH WEDNESDAY AS THE ENTIRE SETUP
SLOWLY SHIFTS EASTWARD...IF AND WHEN THE RIDGE BREAKS DOWN THE
POTENTIAL EXISTS FOR A MULTI- DAY RAIN EVENT AS THE ROCKIES LOW
SHIFTS EAST AND TAPS INTO RICH GULF MOISTURE. TEMPS WILL BE
GENERALLY NEAR NORMAL WITH HIGHS IN THE 50S AND LOWS IN THE 30S
AND 40S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
THROUGH 00Z FRIDAY...BKN/OVC VFR CEILINGS AND VISIBILITIES TO PREVAIL
THROUGH EARLY MORNING THURSDAY BEFORE CEILINGS SCATTER OUT LATER
IN THE DAY. SUSTAINED NORTH WINDS 10-12 KTS WITH 20-28 KT GUSTS
DROPPING OFF OVER THE NEXT COUPLE OF HOURS. HOWEVER...ANTICIPATE
GUSTS TO PICK BACK UP AGAIN BY AROUND 12-14Z AS MIXING COMMENCES.
OUTLOOK 00Z FRIDAY THROUGH MONDAY...
00Z FRI THRU 00Z SAT...VFR UNDER HIGH PRESSURE. CONTINUED GUSTS FROM
THE NW 00Z THRU 12Z FRI.
00Z SAT THRU 00Z MON...MAINLY VFR WITH CHANCE OF MVFR SHOWERS
ASSOCIATED WITH A WEAK LOW PASSAGE.
MONDAY...MAINLY VFR UNDER SCT-BKN SKIES.
&&
.FIRE WEATHER...
FIRE WEATHER CONCERNS INCREASE ON THURSDAY FOR ELEVATIONS BELOW
1500 FEET ACROSS SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT
DRY SPELL...EXPECTED BREEZY WINDS...AND LOW MIN RH VALUES.
THE LAST MEASURABLE PRECIP AT SPRINGFIELD VT ASOS WAS
4/15/14...WHEN 0.70" OCCURRED...SINCE THEN ONLY A TRACE OF PRECIP
HAS BEEN OBSERVED. SIMILAR CONDITIONS HAVE BEEN NOTED AT
RUTLAND AWOS SITE. THIS HAS RESULTED IN SIGNIFICANT DRYING OF THE
FINE FUELS PER LOCAL FOREST CONTACTS BELOW 1500 FEET...WHERE GREEN
UP HAS NOT OCCURRED. MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE
FUELS AND LEAF LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL
WET. MOST OF CENTRAL/NORTHERN VT MTNS AND PARTS OF NORTHERN NY
HAVE RECEIVED MEASURABLE PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW
PACK IS STILL ON THE GROUND ABOVE 2000 FEET...RESULTING IN LIMITED
THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
30 MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY ON THURSDAY. IN ADDITION...MIN AFTN RH
VALUES WL DROP BTWN 25% AND 35% BTWN 1 PM AND 5PM ON THURSDAY ACRS
THIS AREA...WITH ISOLATED READINGS OF 20% NEAR SPRINGFIELD VT
POSSIBLE.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL AND
YOU WILL WANT TO PAY CLOSE ATTENTION TO ANY OUTDOOR BURNING YOU MAY
BE ATTEMPTING ON THURSDAY. MONITOR WEATHER CONDITIONS...DO NOT LEAVE
YOUR BRUSH OR DEBRIS PILE UNATTENDED...AND HEED ANY ADVICE FROM YOUR
LOCAL FIRE WARDEN.
GIVEN THE SMALL GEOGRAPHICAL AREA WITH FAVORABLE FUEL CONDITIONS AND
MARGINAL FIRE WEATHER PARAMETERS...NO FIRE WEATHER WATCH WILL BE
ISSUED WITH THIS PACKAGE...BUT WILL HIGHLIGHT IN HWO PRODUCT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...RJS/TABER
SHORT TERM...TABER
LONG TERM...LAHIFF
AVIATION...LAHIFF/LOCONTO
FIRE WEATHER...TABER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
206 PM EDT TUE APR 22 2014
.SYNOPSIS...
RAIN SHOWERS WILL BE LIKELY THIS AFTERNOON AND EVENING AS A COLD
FRONT MOVES EAST ACROSS NEW YORK AND NORTHEAST PENNSYLVANIA. IT
WILL BE COOLER WEDNESDAY AND RAIN SHOWERS MAY BE POSSIBLE THROUGH
THE AFTERNOON. HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY
BRINGING DRY AND BEAUTIFUL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
1230 PM EDT UPDATE...
ADJUSTED NEAR TERM POPS TO MATCH REALITY ON THE RADAR. EXPECT
THESE SHOWERS TO SLOWLY PUSH EAST. THERE APPEARS TO BE A GAP
BETWEEN THE FROPA AND THE 1ST ROUND OF SHOWERS. HRRR MODEL APPEARS
TO BE DOING VERY WELL WITH THE PLACEMENT OF THE SHOWER ACTIVITY
AND DECIDED TO LEAN TOWARDS THE OUTPUT OF THE MODEL. OTHERWISE
PREVIOUS FORECAST LOOKS GOOD.
PREVIOUS FORECAST...
1150 AM EDT UPDATE...
TWO FEATURES OF INTEREST WILL MOVE ACROSS THE CWA TODAY BRINGING
THE CHANCE FOR RAIN SHOWERS ACROSS NEPA AND CNY. THE FIRST FEATURE
OF INTEREST IS THE IS A SUBTLE TROUGH THAT IS PRESENTLY OVER
WESTERN NEW YORK. THIS TROUGH IS WHATS PRODUCING THE RAIN SHOWERS
THIS MORNING. THE TROUGH WILL MOVE EAST THIS MORNING AND EJECT A
VORT MAX ACROSS CENTRAL NY. THIS LEADING TROUGH IS MOST PRONOUNCED
AT 700MB... AND BELIEVE THIS WILL CREATE MID LVL INSTABILITY WHICH
MAY PRODUCE SOME THUNDER ACROSS NE PA AND POSSIBLY CENTRAL NY.
MOISTURE WILL BE LIMITED WITH THIS SYSTEM AS NO DIRECT CONNECTION
WITH THE GULF IS OCCURRING. PWAT VALUES ARE MOSTLY BELOW AN INCH
AND VERY DRY AIR AT THE SFC IS STILL PRESENT ACROSS THE EASTERN
PORTIONS OF THE CWA. AFTER THAT BEING SAID... WE MAY SEE UP TO A
QUARTER OF AN INCH OR RAIN OVER THE CWA THIS AFTERNOON. IF
CONVECTION IS ABLE TO DEVELOP... ISOLATED AREAS MAY SEE SLIGHTLY
HIGHER AMOUNTS.
EXPECT THE FIRST WAVE TO MOVE EAST OF THE CWA BY AROUND 18Z.
TEMPERATURE ACROSS THE REGION TO RISE INTO THE UPPR 60S TO LOW 70S
THIS AFTERNOON DESPITE THE DENSE CLOUD COVERAGE... WHICH IS EXPECT
TO LAST FOR MOST OF THE DAY.
THE SECOND FEATURE OF INTEREST IS THE MORE PROMINENT UPPR LVL LOW
WHICH IS LOCATED OVER THE GREAT LAKES REGION. THIS LOW WILL MOVE
EAST TODAY AND FORCE A COLD FRONT ACROSS THE CWA. THE FRONT IS
EXPECTED TO BE THROUGH MOST OF THE CWA BY 00Z TONIGHT. THIS FRONT
WILL BRING US AN ADDITIONAL SHOT FOR RAIN SHOWERS WITH THE
PASSAGE... AKA... A TYPICAL ANA FRONT SCENARIO. TEMPS BEHIND THE
FRONT WILL SLOWLY DECREASE INTO THE 30S LATE TONIGHT. THE FRONT IS
FOLLOWING CLOSELY BEHIND THE LEADING WAVE. THIS FRONT WILL AID TO
THE DEVELOPMENT OF RAIN SHOWERS AND CAN BE SEEN WITH AS AN
ADDITIONAL LINE OF SHOWERS BEHIND THE FIRST SYSTEM COMPRISED OF
HIGHER REFLECTIVITY.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
3 AM UPDATE...
WED COOL AND SHOWERY WITH SLOWING STACKED LOW IN ERN NEW ENGLAND.
NW CAA FLOW WILL ADD SOME LAKE MOISTURE BUT TEMPERATURE
DIFFERENTIAL NOT ENOUGH FOR PURE LAKE EFFECT. WED MORN SECONDARY
COLD FRONT GOES THROUGH THEN SHOWER COVERAGE WILL DECREASE THE
REST OF THE DAY. LATE WED THE LAST OF THE SHOWERS SHOULD END. WITH
CAA SFC MAX TEMPS WILL STRUGGLE INTO THE U40S AND L50S.
WED NGT WILL BE COLD WITH WINDS BECOMING LIGHT AND CLEAR SKIES.
LOWS U20S TO A30.
THU WILL BE A NICE DAY WITH TEMPS RECOVERING INTO THE 50S AND EVEN
L60S SRN VALLEYS. SKIES MOSTLY SUNNY UNDER AN UPPER LEVEL RIDGE
AND SFC HIGH DURING THE AFTN.
THU NGT INCREASING CLOUDS AHEAD OF THE NEXT FRONT FRI AFTN. PRECIP
SHOULD HOLD OFF WITH THE HIGH ONLY MOVG INTO ERN NY. TREND AGAIN
TO DELAY THE FRONT A FEW HOURS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
2 PM UPDATE...
SYSTEM WILL BE MOVING THRU CWA TO START OFF THE EXTNDD PD WITH A
SHOWERY WEEKEND ON TAP. HIPRES WL BUILD IN SUN NGT BRINGING AN END
TO THE RAIN. TEMPS WL MODERATE THRU THE END OF THE LONG TERM BUT
RMN BLO NORMAL. BOTH GFS AND EURO AGREE ON DVLPMNT OF CLOSED LOW
OVR CANADIAN MARITIMES BY EARLY IN THE WEEK. THIS SUPPLY OF CONT`D
COLD AIR WL KEEP CHCS FOR RAIN/SNOW MIX IN FOR THE MRNG HRS THEN
BCMG RAIN SHOWERS DRG THE AFTN.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
AREA OF VFR SHOWERS IS MOVING THROUGH TERMINALS AT THIS TIME AND
POTENTIAL STILL EXISTS FOR BFR MVFR VSBY RESTRICTION IN THE NEXT
HOUR OR TWO AS THEY MOVE THROUGH. REMOVED -TSRA AS IT DOES NOT
APPEAR ANY THUNDER WILL DEVELOP TODAY. COLD FRONT WILL MOVE
THROUGH AROUND 19Z AT NY TERMINALS AND CLOSER TO 21Z AT KAVP.
AFTER IT DOES SO, LOW LEVEL MOISTURE IN COLD AIR ADVECTION WILL
LEAD TO MVFR CIGS TONIGHT, POSSIBLY AS LOW AS IFR AT KITH BETWEEN
08Z AND 12Z. CIGS EXPECTED TO RANGE FROM 1500-2500FT OVERNIGHT.
MAY SEE AN UNRESTRICTED SHOWER AS UPPER LEVEL TROF PASSES AFTER
06Z. EXPECT CIGS TO RISE TO VFR AT KSYR, KELM AND KAVP AFTER 14Z
WEDNESDAY WITH REMAINING TERMINALS EXPERIENCING MVFR CIGS THROUGH
THE END OF TAF VALID TIME.
WINDS FROM THE SSW AROUND 10KTS WILL QUICKLY SHIFT TO A MORE
WESTERLY FLOW IN THE NEXT HOUR OR TWO AS COLD FRONT PASSES.
NORTHWEST WINDS EXPECTED TONIGHT AROUND 10KTS WITH OCCASIONAL
GUSTS BETWEEN 15-20KTS, BECOMING GUSTIER DURING THE DAY WEDNESDAY
BUT REMAINING OUT OF THE NORTHWEST.
OUTLOOK...
WED NGT-THU NGT...VFR.
FRI-SUN... RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
645 AM UPDATE... DESPITE POOR HUMIDITY RECOVERY OVERNIGHT...A
COLD FRONT WILL BRING UP TO A FEW TENTHS OF AN INCH OF RAIN INTO
THE AREA THIS AFTERNOON TO EARLY EVENING...PUTTING A HOLD ON FIRE
WEATHER CONCERNS AFTER THE RECENT WARM DRY SPELL.
NEXT DAY TO WATCH WILL BE THURSDAY WITH 10 TO 20 MPH WINDS AND RH
BELOW 30 PERCENT. QUESTION HERE WHETHER FUELS WILL DRY OUT IN
TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KAH
NEAR TERM...KAH
SHORT TERM...TAC
LONG TERM...PVN
AVIATION...PVN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1225 PM EDT TUE APR 22 2014
.SYNOPSIS...
RAIN SHOWERS WILL BE LIKELY THIS AFTERNOON AND EVENING AS A COLD
FRONT MOVES EAST ACROSS NEW YORK AND NORTHEAST PENNSYLVANIA. IT
WILL BE COOLER WEDNESDAY AND RAIN SHOWERS MAY BE POSSIBLE THROUGH
THE AFTERNOON. HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY
BRINGING DRY AND BEAUTIFUL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
1230 PM EDT UPDATE...
ADJUSTED NEAR TERM POPS TO MATCH REALITY ON THE RADAR. EXPECT
THESE SHOWERS TO SLOWLY PUSH EAST. THERE APPEARS TO BE A GAP
BETWEEN THE FROPA AND THE 1ST ROUND OF SHOWERS. HRRR MODEL APPEARS
TO BE DOING VERY WELL WITH THE PLACEMENT OF THE SHOWER ACTIVITY
AND DECIDED TO LEAN TOWARDS THE OUTPUT OF THE MODEL. OTHERWISE
PREVIOUS FORECAST LOOKS GOOD.
PREVIOUS FORECAST...
1150 AM EDT UPDATE...
TWO FEATURES OF INTEREST WILL MOVE ACROSS THE CWA TODAY BRINGING
THE CHANCE FOR RAIN SHOWERS ACROSS NEPA AND CNY. THE FIRST FEATURE
OF INTEREST IS THE IS A SUBTLE TROUGH THAT IS PRESENTLY OVER
WESTERN NEW YORK. THIS TROUGH IS WHATS PRODUCING THE RAIN SHOWERS
THIS MORNING. THE TROUGH WILL MOVE EAST THIS MORNING AND EJECT A
VORT MAX ACROSS CENTRAL NY. THIS LEADING TROUGH IS MOST PRONOUNCED
AT 700MB... AND BELIEVE THIS WILL CREATE MID LVL INSTABILITY WHICH
MAY PRODUCE SOME THUNDER ACROSS NE PA AND POSSIBLY CENTRAL NY.
MOISTURE WILL BE LIMITED WITH THIS SYSTEM AS NO DIRECT CONNECTION
WITH THE GULF IS OCCURRING. PWAT VALUES ARE MOSTLY BELOW AN INCH
AND VERY DRY AIR AT THE SFC IS STILL PRESENT ACROSS THE EASTERN
PORTIONS OF THE CWA. AFTER THAT BEING SAID... WE MAY SEE UP TO A
QUARTER OF AN INCH OR RAIN OVER THE CWA THIS AFTERNOON. IF
CONVECTION IS ABLE TO DEVELOP... ISOLATED AREAS MAY SEE SLIGHTLY
HIGHER AMOUNTS.
EXPECT THE FIRST WAVE TO MOVE EAST OF THE CWA BY AROUND 18Z.
TEMPERATURE ACROSS THE REGION TO RISE INTO THE UPPR 60S TO LOW 70S
THIS AFTERNOON DESPITE THE DENSE CLOUD COVERAGE... WHICH IS EXPECT
TO LAST FOR MOST OF THE DAY.
THE SECOND FEATURE OF INTEREST IS THE MORE PROMINENT UPPR LVL LOW
WHICH IS LOCATED OVER THE GREAT LAKES REGION. THIS LOW WILL MOVE
EAST TODAY AND FORCE A COLD FRONT ACROSS THE CWA. THE FRONT IS
EXPECTED TO BE THROUGH MOST OF THE CWA BY 00Z TONIGHT. THIS FRONT
WILL BRING US AN ADDITIONAL SHOT FOR RAIN SHOWERS WITH THE
PASSAGE... AKA... A TYPICAL ANA FRONT SCENARIO. TEMPS BEHIND THE
FRONT WILL SLOWLY DECREASE INTO THE 30S LATE TONIGHT. THE FRONT IS
FOLLOWING CLOSELY BEHIND THE LEADING WAVE. THIS FRONT WILL AID TO
THE DEVELOPMENT OF RAIN SHOWERS AND CAN BE SEEN WITH AS AN
ADDITIONAL LINE OF SHOWERS BEHIND THE FIRST SYSTEM COMPRISED OF
HIGHER REFLECTIVITY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
3 AM UPDATE...
WED COOL AND SHOWERY WITH SLOWING STACKED LOW IN ERN NEW ENGLAND.
NW CAA FLOW WILL ADD SOME LAKE MOISTURE BUT TEMPERATURE
DIFFERENTIAL NOT ENOUGH FOR PURE LAKE EFFECT. WED MORN SECONDARY
COLD FRONT GOES THROUGH THEN SHOWER COVERAGE WILL DECREASE THE
REST OF THE DAY. LATE WED THE LAST OF THE SHOWERS SHOULD END. WITH
CAA SFC MAX TEMPS WILL STRUGGLE INTO THE U40S AND L50S.
WED NGT WILL BE COLD WITH WINDS BECOMING LIGHT AND CLEAR SKIES.
LOWS U20S TO A30.
THU WILL BE A NICE DAY WITH TEMPS RECOVERING INTO THE 50S AND EVEN
L60S SRN VALLEYS. SKIES MOSTLY SUNNY UNDER AN UPPER LEVEL RIDGE
AND SFC HIGH DURING THE AFTN.
THU NGT INCREASING CLOUDS AHEAD OF THE NEXT FRONT FRI AFTN. PRECIP
SHOULD HOLD OFF WITH THE HIGH ONLY MOVG INTO ERN NY. TREND AGAIN
TO DELAY THE FRONT A FEW HOURS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
3 AM UPDATE...
LITTLE CHANGE. AGAIN FOLLOWED WPC GUIDANCE. DIFFERENCES IN MODELS
WILL MAKE A BIG DIFFERENCE IN TEMPERATURES AND PRECIP TYPES.
POSITIONING OF FRONTS WILL MAKE A DIFFERENCE TOO. BOTTOM LINE
UNSETTLED AND COOL.
PREVIOUS DISCUSSION...
GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE PATTERN THROUGH
SATURDAY THEN DIFFERENCES DEVELOP FOR SUNDAY INTO EARLY NEXT WEEK.
BOTH MODELS AGREE WITH THE IDEA THAT A SHORT WAVE AND ASSOCIATED
SURFACE COLD FRONT PASS EAST ACROSS THE AREA ON FRIDAY BRINGING A
CHANCE OF SHOWERS. LITTLE INSTABILITY IS INDICATED AND NO THUNDER
WILL BE MENTIONED IN THE FORECAST. SCATTERED SHOWERS MAY LINGER
INTO SATURDAY ALONG WITH SOMEWHAT COOLER CONDITIONS AS AN UPPER
TROUGH MOVES EAST ACROSS SOUTHERN CANADA. THE GFS IS SLOWER AND
MORE AMPLIFIED WITH THE UPPER TROUGH KEEPING A CHANCE OF SHOWERS
AND MUCH COOLER WEATHER SUNDAY INTO EARLY NEXT WEEK... WHILE THE
ECMWF IS MORE PROGRESSIVE INDICATING A MAINLY DRY SCENARIO FOR
SUNDAY INTO MONDAY. WITH THIS UNCERTAINTY HAVE KEPT LOW CHC POPS
GOING SUNDAY THROUGH MONDAY. REGARDLESS OF RAIN CHANCES
TEMPERATURES WILL LIKELY BE AT LEAST A LITTLE BELOW NORMAL
SATURDAY THROUGH MONDAY.
DESPITE SOME DOWNSTREAM DISAGREEMENT BOTH THE GFS AND ECMWF
INDICATE THE DEVELOPMENT OF A STRONG UPPER LEVEL RIDGE OVER
CENTRAL CANADA EARLY NEXT WEEK WHICH SHOULD FAVOR AT LEAST SOME
TROUGHING AND BELOW NORMAL TEMPERATURES OVER THE EASTERN U.S.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...
STILL VFR FOR NOW...BUT CLOUDS ARE INCREASING AND THICKENING AHEAD
OF INCOMING COLD FRONT. EXPECT A GRADUAL LOWERING OF CIGS WITH
RAIN OVERSPREADING THE AREA SHORTLY AFTER 15Z. MAIN BAND OF
SHOWERS ALONG FRONT WILL MOVE WNW TO ENE FROM 16Z-22Z INCLUDING
MVFR RESTRICTIONS AND POSSIBLE THUNDER...SEE INDIVIDUAL TAFS FOR
SPECIFICS OF TIMING. ONLY HAVE CB IN KBGM-KAVP TAFS AT THIS
TIME...ALSO POSSIBLE AT KELM-KITH BUT CONFIDENCE IS TOO LOW TO
INCLUDE IN TAF /WATCH FOR AMENDMENTS/. SOUTHWEST WINDS AHEAD OF
THE FRONT AROUND 10 KTS OR LESS...WILL VEER TO NORTHWEST BEHIND
THE FRONT WITH GUSTS IN THE TEENS...ALONG WITH DEVELOPMENT OF MVFR
STRATUS CIG AND EVENTUAL POST FRONTAL SCT -SHRA. HOWEVER...THE IMMEDIATE
FRONTAL SHOWER-THUNDER BAND THIS AFTERNOON WILL LIKELY INCLUDE A
PUSH OF 20-25 KT GUSTS AS INDICATED IN TAFS WITHIN THE TEMPO GROUPS.
OUTLOOK...
WED...SCT -SHRA AND LINGERING MVFR CIGS ON BACK SIDE OF SYSTEM.
WED NGT-THU NGT...VFR.
FRI-SAT... RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
645 AM UPDATE... DESPITE POOR HUMIDITY RECOVERY OVERNIGHT...A
COLD FRONT WILL BRING UP TO A FEW TENTHS OF AN INCH OF RAIN INTO
THE AREA THIS AFTERNOON TO EARLY EVENING...PUTTING A HOLD ON FIRE
WEATHER CONCERNS AFTER THE RECENT WARM DRY SPELL.
NEXT DAY TO WATCH WILL BE THURSDAY WITH 10 TO 20 MPH WINDS AND RH
BELOW 30 PERCENT. QUESTION HERE WHETHER FUELS WILL DRY OUT IN
TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KAH
NEAR TERM...KAH
SHORT TERM...TAC
LONG TERM...JAB/MSE/TAC
AVIATION...MDP
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1126 AM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL SWING ACROSS THE STATE TODAY...ACCOMPANIED WITH
LIGHT RAIN SHOWERS. AFTER A BRIEF LULL IN THE PRECIPITATION...AND
THEN AS COLDER AIR BUILDS IN BEHIND THE COLD FRONT TONIGHT A
SECONDARY BATCH OF LIGHT RAIN SHOWERS WILL MIX WITH SNOW TONIGHT AND
WEDNESDAY MORNING. TEMPERATURES WILL THEN GRADUALLY WARM THROUGH THE
END OF THE WEEK AS SURFACE HIGH PRESSURE BUILDS ACROSS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1100 AM...SURFACE ANALYSIS SHOWED A COLD FRONT ENTERING THE
NIAGARA FRONTIER. AHEAD OF THIS FRONT IS A SOLID LINE OF RAIN
SHOWERS WHICH WILL BRING ABOUT 3 HOURS AND ABOUT A QUARTER INCH OF
RAIN. MEANWHILE...WARM AND MOIST AIR STREAMING UP LAKE ERIE WILL
MIX WITH COOLER LAKE WATERS...RESULTING IN FOG ON THE NIAGARA
FRONTIER AND EVENTUALLY NE OF LAKE ONTARIO LATER THIS MORNING. FOG
WILL DISSIPATE SHORTLY AFTER THE WIND SHIFT. FOR TIMING
THIS...USED THE HRRR WHICH HAS A GOOD HANDLE ON THE POSITION OF
THE FRONT AND WIND SHIFT.
VISIBLE SATELLITE ALREADY SHOWS BREAKS IN CLOUDS ACROSS SOUTHERN
ONTARIO...BUT THIS MAY FILL IN SINCE IT IS STILL AHEAD OF THE
SHORTWAVE...WITH SCATTERED SHOWERS POSSIBLE WITH ITS PASSAGE.
MEANWHILE...A MORE SIGNIFICANT DRY SLOT IS DEVELOPING JUST BEHIND
THE UPPER TROF...WHICH SHOULD PROVIDE AT LEAST A PERIOD OF DRY
WEATHER THIS AFTERNOON ACROSS WESTERN PORTIONS OF THE CWA.
AS UPSTREAM SHORTWAVES DEEPEN THE UPPER LEVEL TROUGH AND A
SECONDARY SURFACE TROUGH DROPS ACROSS THE REGION TONIGHT EXPECT
ANOTHER PERIOD OF LIGHT PRECIPITATION TO DEVELOP. MOISTURE
WRAPPING AROUND THIS SURFACE LOW WILL BE PLENTIFUL. THIS INCREASE
IN MOISTURE WILL BRING LIGHT SHOWERS AND DRIZZLE ACROSS LOWER
ELEVATIONS TONIGHT...BUT ACROSS HIGHER TERRAIN AS THE COLD AIR
DEEPENS...850 HPA TEMPS DROPPING DOWN TO -3 TO -5C...A CHANGE OVER
TO SOME WET SNOW IS POSSIBLE. WILL HAVE HIGHEST POPS TONIGHT OVER
THE HIGHER TERRAIN WITH AN UPSLOPE FLOW. GREATEST CHANCES FOR SOME
SNOW WILL ALSO BE ACROSS HIGHER TERRAIN WHERE A SLUSHY HALF INCH
OR SO OF SNOW IS POSSIBLE BY DAYBREAK.
TEMPERATURES ARE MILD THIS MORNING AHEAD OF THE COLD
FRONT...BUT EXPECT THESE TEMPERATURES TO SLOWLY DROP THROUGH THE
AFTERNOON AS THE COLD AIR FILTERS ACROSS THE REGION. TEMPERATURES
TONIGHT WILL BE MUCH COLDER THAN THIS MORNING WITH OVERNIGHT LOWS
DROPPING BACK INTO THE LOW TO MID 30S TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
THE AREA WILL BE UNDER A MOIST CYCLONIC NORTHWEST FLOW AT THE START
OF THE PERIOD WITH THE BETTER CHANCES FOR PRECIPITATION LIKELY TIED
TO THE HIGHER TERRAIN...WHERE UPSLOPE FLOW WILL HELP TO SQUEEZE OUT
ADDITIONAL MOISTURE. WE MAY ALSO SEE A BIT OF MOISTURE FLUX OFF OF
THE LAKES...ALTHOUGH TEMPERATURES ARE NOT COLD ENOUGH FOR TRUE LAKE
EFFECT PROCESSES. DEEPER MOISTURE WILL GRADUALLY PULL AWAY FROM THE
AREA DURING THE DAY. HOWEVER...THE REMAINING CYCLONIC FLOW AND COLD
AIR ALOFT WILL LIKELY CAUSE CLOUDS TO HANG AROUND FOR MUCH OF THE
DAY. DURING THE MID AND LATE AFTERNOON...THE LAKES WILL BECOME A
STABILIZING INFLUENCE... RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKES AND LAKESHORE AREAS FIRST. THEN...THE CLEARING WILL SPREAD
INLAND. IT WILL BE ESPECIALLY CHILLY FOR THIS TIME OF YEAR WITH
HIGHS BARELY REACHING 50. THE COOL TEMPERATURES WILL ALSO BE
ACCOMPANIED BY A BRISK NORTHWEST FLOW WITH GUSTS IN THE 25-35 MPH
RANGE.
HIGH PRESSURE BUILDING INTO THE GREAT LAKES REGION WILL LEAD TO A
DRY PERIOD FOR WEDNESDAY NIGHT AND THURSDAY. THERE MAY BE A FEW
LINGERING CLOUDS OVER THE INTERIOR HIGHER TERRAIN TO START THE
EVENING...BUT OTHERWISE EXPECT CLEAR SKIES WEDNESDAY NIGHT AND SUNNY
SKIES FOR THURSDAY.
THE COOL AIRMASS AND CLEARING SKIES WILL ALLOW FOR A COLD NIGHT
WEDNESDAY NIGHT...WITH LOWS IN THE UPPER 20S TO LOWER 30S ON THE
LAKE PLAINS AND LOWER TO MID 20S IN THE COOLER INTERIOR LOCATIONS.
THE LATE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK CLOSER TO NORMAL
FOR THURSDAY WITH BACK INTO THE MID 50S IN MANY AREAS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM HAS THE POTENTIAL TO BE QUITE UNSETTLED WITH A BRIEF
WARM-UP AT THE END OF THE WEEK FOLLOWED BY WELL BELOW AVERAGE
TEMPERATURES NEXT WEEKEND.
LOOKING AT THE DETAILS...ON FRIDAY A MID LEVEL SHORTWAVE AND WARM
OCCLUSION AT THE SURFACE WILL SWING QUICKLY EAST ACROSS THE REGION
WITH A CHANCE OF A FEW SHOWERS. THE RAIN SHOULD BE BRIEF AT ANY
GIVEN LOCATION AND SHOULD BE MAINLY IN THE MORNING ACROSS WESTERN
NY. A WARMER AIRMASS WILL MAKE A BRIEF APPEARANCE INTO THE LOWER
LAKES REGION WITH MOST AREAS REACHING THE LOW TO MID 60S FOR HIGHS.
MODEL GUIDANCE QUICKLY DIVERGES WITH RESPECT TO THE SYNOPTIC SCALE
EVOLUTION OVER THE WEEKEND...ALTHOUGH BOTH THE GFS AND ECMWF AND
MOST ENSEMBLES SUPPORT A TURN TOWARDS MUCH COLDER TEMPERATURES. THE
ECMWF SWINGS A PROGRESSIVE MID LEVEL CUTOFF THROUGH ONTARIO AND
QUEBEC OVER THE WEEKEND BEFORE REACHING THE CANADIAN MARITIMES ON
MONDAY...WITH A TROUGH DELIVERING A MUCH COOLER AIRMASS INTO THE
GREAT LAKES AND NORTHEAST. THE CUTOFF LOW IN THIS SCENARIO WOULD BE
FAR ENOUGH NORTH AND EAST TO KEEP OUR REGION MAINLY DRY.
THE GFS ON THE OTHER HAND RETROGRADES THE CLOSED LOW ON SUNDAY AND
MONDAY...KEEPING IT OVER OR JUST EAST OF NEW ENGLAND. THIS WOULD BE
CLOSE ENOUGH TO KEEP MORE WRAP AROUND MOISTURE AND PRECIP CHANCES
ACROSS OUR REGION...AND WITH THE COLDER AIR SOME OF THIS MAY BE IN
THE FORM OF WET SNOW...ESPECIALLY DURING THE LATE NIGHT AND EARLY
MORNING HOURS. GIVEN THE MODEL DISAGREEMENT...HAVE KEPT CHANCE POPS
THROUGH THE WEEKEND AND INTO MONDAY WITH SOME MIX OF SNOW AT TIMES.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
LIFR/IFR CONDITIONS SHOULD CONTINUE AT BUF/IAG AND WILL PROBABLY
NOT IMPROVE UNTIL WINDS SHIFT TO THE NW. THE MAIN CAUSE IS DEW
POINTS AROUND 50 OVERRUNNING THE MUCH COLDER LAKE ERIE WHICH IS
RESULTING IN LOW CIGS AND GROUND FOG. THIS WILL ALSO BECOME AN
ISSUE AT ART LATE THIS MORNING AND EARLY AFTERNOON...WHILE INLAND
SITES SUCH AS ROC SHOULD HAVE LESS OF AN IMPACT DUE TO THE
FURTHER DISTANCE FROM THE LAKES IN THE SOUTHWEST PRE-FRONTAL FLOW.
A DRY SLOT BEHIND THE COLD FRONT WILL LIKELY BRING A RETURN TO VFR
FLIGHT CONDITIONS LATER THIS AFTERNOON AND EARLY EVENING. THIS WILL
BE BRIEF AS WRAP AROUND MOISTURE BEHIND THE MAIN AREA OF LOW
PRESSURE WILL LOWER CIGS BACK TO IFR/MVFR THROUGH TONIGHT WITH LIGHT
SHOWERS...AND POSSIBLY SOME SNOW MIXING IN LATE ACROSS HIGHER
TERRAIN. THIS SNOW MAY BRING ANOTHER PERIOD OF IFR FLIGHT CONDITIONS
TO THE SOUTHERN TIER...INCLUDING KJHW.
OUTLOOK...
EARLY WEDNESDAY...VFR/MVFR. A CHANCE OF RAIN SHOWERS OR SNOW SHOWERS
ACROSS HIGHER TERRAIN.
WEDNESDAY AFTERNOON THROUGH THURSDAY...VFR.
FRIDAY AND SATURDAY...VFR/MVFR. A CHANCE OF SHOWERS.
&&
.MARINE...
SOUTHWEST WINDS AHEAD OF THE COLD FRONT ARE INCREASING TO ABOUT 20
KNOTS THIS MORNING ALONG THE LAKE ERIE SHORELINE...AND WILL HOIST A
SMALL CRAFT ADVISORY HERE...AND CONTINUE IT INTO THE OVERNIGHT
HOURS. ELSEWHERE SCA WILL REMAIN ON LAKE ONTARIO AS WEST TO
NORTHWEST WINDS AND WAVES AREA EXPECTED TO INCREASE BEHIND A COLD
FRONT TODAY.
TONIGHT WINDS WILL CONTINUE TO VEER TO NORTHWEST TO NORTHERLY
OVER THE WESTERN END OF LAKE ONTARIO. THIS MAY NECESSITATE A SCA
FOR THE LOWER NIAGARA RIVER LATER TONIGHT.
HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKES WEDNESDAY AND
THURSDAY WITH A RETURN TO NON-SCA CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT WEDNESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 11
AM EDT THURSDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT WEDNESDAY FOR LOZ042.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 AM EDT
THURSDAY FOR LOZ045.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...HITCHCOCK/TMA
AVIATION...APFFEL/THOMAS
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
956 AM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL SWING ACROSS THE STATE TODAY...ACCOMPANIED WITH
LIGHT RAIN SHOWERS. AFTER A BRIEF LULL IN THE PRECIPITATION...AND
THEN AS COLDER AIR BUILDS IN BEHIND THE COLD FRONT TONIGHT A
SECONDARY BATCH OF LIGHT RAIN SHOWERS WILL MIX WITH SNOW TONIGHT AND
WEDNESDAY MORNING. TEMPERATURES WILL THEN GRADUALLY WARM THROUGH THE
END OF THE WEEK AS SURFACE HIGH PRESSURE BUILDS ACROSS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1000 AM...SURFACE ANALYSIS SHOWED A COLD FRONT JUST ENTERING
THE NIAGARA FRONTIER. AHEAD OF THIS...RADAR SHOWS A SOLID LINE OF
RAIN SHOWERS. THIS WILL BRING ABOUT 3 HOURS OF RAIN TO THE
REGION...WITH AMOUNTS AVERAGING AROUND A QUARTER INCH. MEANWHILE...WARM
AND MOIST AIR STREAMING UP LAKE ERIE WILL MIX WITH COOLER LAKE
WATERS...RESULTING IN FOG ON THE NIAGARA FRONTIER AND EVENTUALLY
NE OF LAKE ONTARIO LATER THIS MORNING. FOG WILL DISSIPATE SHORTLY
AFTER THE WIND SHIFT. FOR TIMING THIS...USED THE HRRR WHICH HAS A
GOOD HANDLE ON THE POSITION OF THE FRONT AND WIND SHIFT.
FOR LATER THIS AFTERNOON...WATER VAPOR IMAGERY SHOWS A DEVELOPING
DRY SLOT NOW OVER THE CENTRAL GREAT LAKES. THIS DRY SLOT WILL
REACH WNY THIS AFTERNOON AND ALLOW FOR A BRIEF OPPORTUNITY FOR
SOME LIMITED SUNSHINE. AS UPSTREAM SHORTWAVES DEEPEN THE UPPER
LEVEL TROUGH AND A SECONDARY SURFACE TROUGH DROPS ACROSS THE
REGION TONIGHT EXPECT ANOTHER PERIOD OF LIGHT PRECIPITATION TO
DEVELOP. MOISTURE WRAPPING AROUND THIS SURFACE LOW WILL BE
PLENTIFUL. THIS INCREASE IN MOISTURE WILL BRING LIGHT SHOWERS AND
DRIZZLE ACROSS LOWER ELEVATIONS TONIGHT...BUT ACROSS HIGHER
TERRAIN AS THE COLD AIR DEEPENS...850 HPA TEMPS DROPPING DOWN TO
-3 TO -5C...A CHANGE OVER TO SOME WET SNOW IS POSSIBLE. WILL HAVE
HIGHEST POPS TONIGHT OVER THE HIGHER TERRAIN WITH AN UPSLOPE FLOW.
GREATEST CHANCES FOR SOME SNOW WILL ALSO BE ACROSS HIGHER TERRAIN
WHERE A SLUSHY HALF INCH OR SO OF SNOW IS POSSIBLE BY DAYBREAK.
TEMPERATURES ARE MILD THIS MORNING AHEAD OF THE COLD
FRONT...BUT EXPECT THESE TEMPERATURES TO SLOWLY DROP THROUGH THE
AFTERNOON AS THE COLD AIR FILTERS ACROSS THE REGION. TEMPERATURES
TONIGHT WILL BE MUCH COLDER THAN THIS MORNING WITH OVERNIGHT LOWS
DROPPING BACK INTO THE LOW TO MID 30S TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
THE AREA WILL BE UNDER A MOIST CYCLONIC NORTHWEST FLOW AT THE START
OF THE PERIOD WITH THE BETTER CHANCES FOR PRECIPITATION LIKELY TIED
TO THE HIGHER TERRAIN...WHERE UPSLOPE FLOW WILL HELP TO SQUEEZE OUT
ADDITIONAL MOISTURE. WE MAY ALSO SEE A BIT OF MOISTURE FLUX OFF OF
THE LAKES...ALTHOUGH TEMPERATURES ARE NOT COLD ENOUGH FOR TRUE LAKE
EFFECT PROCESSES. DEEPER MOISTURE WILL GRADUALLY PULL AWAY FROM THE
AREA DURING THE DAY. HOWEVER...THE REMAINING CYCLONIC FLOW AND COLD
AIR ALOFT WILL LIKELY CAUSE CLOUDS TO HANG AROUND FOR MUCH OF THE
DAY. DURING THE MID AND LATE AFTERNOON...THE LAKES WILL BECOME A
STABILIZING INFLUENCE... RESULTING IN CLOUDS CLEARING OUT OVER THE
LAKES AND LAKESHORE AREAS FIRST. THEN...THE CLEARING WILL SPREAD
INLAND. IT WILL BE ESPECIALLY CHILLY FOR THIS TIME OF YEAR WITH
HIGHS BARELY REACHING 50. THE COOL TEMPERATURES WILL ALSO BE
ACCOMPANIED BY A BRISK NORTHWEST FLOW WITH GUSTS IN THE 25-35 MPH
RANGE.
HIGH PRESSURE BUILDING INTO THE GREAT LAKES REGION WILL LEAD TO A
DRY PERIOD FOR WEDNESDAY NIGHT AND THURSDAY. THERE MAY BE A FEW
LINGERING CLOUDS OVER THE INTERIOR HIGHER TERRAIN TO START THE
EVENING...BUT OTHERWISE EXPECT CLEAR SKIES WEDNESDAY NIGHT AND SUNNY
SKIES FOR THURSDAY.
THE COOL AIRMASS AND CLEARING SKIES WILL ALLOW FOR A COLD NIGHT
WEDNESDAY NIGHT...WITH LOWS IN THE UPPER 20S TO LOWER 30S ON THE
LAKE PLAINS AND LOWER TO MID 20S IN THE COOLER INTERIOR LOCATIONS.
THE LATE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK CLOSER TO NORMAL
FOR THURSDAY WITH BACK INTO THE MID 50S IN MANY AREAS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM HAS THE POTENTIAL TO BE QUITE UNSETTLED WITH A BRIEF
WARM-UP AT THE END OF THE WEEK FOLLOWED BY WELL BELOW AVERAGE
TEMPERATURES NEXT WEEKEND.
LOOKING AT THE DETAILS...ON FRIDAY A MID LEVEL SHORTWAVE AND WARM
OCCLUSION AT THE SURFACE WILL SWING QUICKLY EAST ACROSS THE REGION
WITH A CHANCE OF A FEW SHOWERS. THE RAIN SHOULD BE BRIEF AT ANY
GIVEN LOCATION AND SHOULD BE MAINLY IN THE MORNING ACROSS WESTERN
NY. A WARMER AIRMASS WILL MAKE A BRIEF APPEARANCE INTO THE LOWER
LAKES REGION WITH MOST AREAS REACHING THE LOW TO MID 60S FOR HIGHS.
MODEL GUIDANCE QUICKLY DIVERGES WITH RESPECT TO THE SYNOPTIC SCALE
EVOLUTION OVER THE WEEKEND...ALTHOUGH BOTH THE GFS AND ECMWF AND
MOST ENSEMBLES SUPPORT A TURN TOWARDS MUCH COLDER TEMPERATURES. THE
ECMWF SWINGS A PROGRESSIVE MID LEVEL CUTOFF THROUGH ONTARIO AND
QUEBEC OVER THE WEEKEND BEFORE REACHING THE CANADIAN MARITIMES ON
MONDAY...WITH A TROUGH DELIVERING A MUCH COOLER AIRMASS INTO THE
GREAT LAKES AND NORTHEAST. THE CUTOFF LOW IN THIS SCENARIO WOULD BE
FAR ENOUGH NORTH AND EAST TO KEEP OUR REGION MAINLY DRY.
THE GFS ON THE OTHER HAND RETROGRADES THE CLOSED LOW ON SUNDAY AND
MONDAY...KEEPING IT OVER OR JUST EAST OF NEW ENGLAND. THIS WOULD BE
CLOSE ENOUGH TO KEEP MORE WRAP AROUND MOISTURE AND PRECIP CHANCES
ACROSS OUR REGION...AND WITH THE COLDER AIR SOME OF THIS MAY BE IN
THE FORM OF WET SNOW...ESPECIALLY DURING THE LATE NIGHT AND EARLY
MORNING HOURS. GIVEN THE MODEL DISAGREEMENT...HAVE KEPT CHANCE POPS
THROUGH THE WEEKEND AND INTO MONDAY WITH SOME MIX OF SNOW AT TIMES.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
LIFR/IFR CONDITIONS SHOULD CONTINUE AT BUF/IAG AND WILL PROBABLY
NOT IMPROVE UNTIL WINDS SHIFT TO THE NW. THE MAIN CAUSE IS DEW
POINTS AROUND 50 OVERRUNNING THE MUCH COLDER LAKE ERIE WHICH IS
RESULTING IN LOW CIGS AND GROUND FOG. THIS WILL ALSO BECOME AN
ISSUE AT ART LATE THIS MORNING AND EARLY AFTERNOON...WHILE INLAND
SITES SUCH AS JHW/ROC SHOULD HAVE LESS OF AN IMPACT DUE TO THE
FURTHER DISTANCE FROM THE LAKES IN THE SOUTHWEST PRE-FRONTAL FLOW.
A DRY SLOT BEHIND THE COLD FRONT WILL LIKELY BRING A RETURN TO VFR
FLIGHT CONDITIONS LATER THIS AFTERNOON AND EARLY EVENING. THIS WILL
BE BRIEF AS WRAP AROUND MOISTURE BEHIND THE MAIN AREA OF LOW
PRESSURE WILL LOWER CIGS BACK TO IFR/MVFR THROUGH TONIGHT WITH LIGHT
SHOWERS...AND POSSIBLY SOME SNOW MIXING IN LATE ACROSS HIGHER
TERRAIN. THIS SNOW MAY BRING ANOTHER PERIOD OF IFR FLIGHT CONDITIONS
TO THE SOUTHERN TIER...INCLUDING KJHW.
OUTLOOK...
EARLY WEDNESDAY...VFR/MVFR. A CHANCE OF RAIN SHOWERS OR SNOW SHOWERS
ACROSS HIGHER TERRAIN.
WEDNESDAY AFTERNOON THROUGH THURSDAY...VFR.
FRIDAY AND SATURDAY...VFR/MVFR. A CHANCE OF SHOWERS.
&&
.MARINE...
SOUTHWEST WINDS AHEAD OF THE COLD FRONT ARE INCREASING TO ABOUT 20
KNOTS THIS MORNING ALONG THE LAKE ERIE SHORELINE...AND WILL HOIST A
SMALL CRAFT ADVISORY HERE...AND CONTINUE IT INTO THE OVERNIGHT
HOURS. ELSEWHERE SCA WILL REMAIN ON LAKE ONTARIO AS WEST TO
NORTHWEST WINDS AND WAVES AREA EXPECTED TO INCREASE BEHIND A COLD
FRONT TODAY.
TONIGHT WINDS WILL CONTINUE TO VEER TO NORTHWEST TO NORTHERLY
OVER THE WESTERN END OF LAKE ONTARIO. THIS MAY NECESSITATE A SCA
FOR THE LOWER NIAGARA RIVER LATER TONIGHT.
HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKES WEDNESDAY AND
THURSDAY WITH A RETURN TO NON-SCA CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT WEDNESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 11
AM EDT THURSDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM EDT
WEDNESDAY FOR LOZ042.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 AM EDT
THURSDAY FOR LOZ045.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...HITCHCOCK/TMA
AVIATION...APFFEL/THOMAS
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
312 PM EDT TUE APR 22 2014
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A FEW SHOWERS THIS EVENING
BEFORE MOVING OFFSHORE LATE TONIGHT. A COOLING AND DRYING TREND
CAN BE EXPECTED THROUGH MID-WEEK...WITH TEMPERATURES RISING NEAR
TO ABOVE NORMAL FRIDAY AND SATURDAY. A WEAK COLD FRONT MAY PASS
ACROSS THE COAST LATE SATURDAY...BRINGING A SLIGHT COOL-DOWN
SUNDAY AND MONDAY. UNSETTLED CONDITIONS COULD DEVELOP THROUGH
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...A COLD FRONT EXTENDING ACROSS EASTERN
KENTUCKY...TENNESSEE...AND NORTHERN ALABAMA WILL MOVE EASTWARD
TONIGHT...REACHING THE CAROLINA COAST AROUND MIDNIGHT. IN ADVANCE OF
THIS FRONT THE AIRMASS IS WARM BUT NOT PARTICULARLY MOIST. LOW-LEVEL
MOISTURE ADVECTION HAS BEEN LIMITED BY A DEEP WEST-SOUTHWESTERLY
FLOW WHICH IS SHUTTING OUT BOTH THE ATLANTIC AND THE GULF OF MEXICO.
IN THE UPPER LEVELS A RATHER IMPRESSIVE TROUGH OVER THE SOUTHERN
APPALACHIANS WILL SWEEP SOUTHEASTWARD AND OFF THE COAST THIS
EVENING. A 300 MB JET STREAK EXTENDING FROM NORTH CAROLINA INTO NEW
ENGLAND WILL BECOME FAVORABLY LOCATED FOR A BRIEF TIME THIS EVENING
TO ENHANCE UPPER LEVEL DIVERGENCE ACROSS OUR AREA. DESPITE THE LACK
OF MOISTURE AND ONLY WEAK INSTABILITY ON THE ORDER OF 500 J/KG...A
BROKEN LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS SHOULD REACH
THE INTERSTATE 95 CORRIDOR BETWEEN 6-8 PM. GIVEN A DEEP DRY
BOUNDARY LAYER WITH DRY ADIABATIC LAPSE RATES NEARLY 7000 FEET
THICK...GUSTY WINDS ARE POSSIBLE EVEN WITH JUST SHOWERS THAT
DEVELOP. ACTIVITY SHOULD WEAKEN AS IT ENCOUNTERS INCREASINGLY STABLE
CONDITIONS TOWARD THE COAST...BUT MAY RESTRENGTHEN ONCE IT
ENCOUNTERS THE MORE UNSTABLE AIR OVER THE GULF STREAM OFFSHORE.
FORECAST POPS RANGE FROM 40-50 PERCENT ALONG AND WEST OF THE I-95
CORRIDOR...TO AROUND 30 PERCENT AT THE COAST.
BEHIND THE SURFACE COLD FRONT WINDS WILL VEER NORTHERLY AND DRIER
AIR WILL BLEED INTO THE REGION. UNDER CLEARING SKIES LOWS SHOULD
REACH 52-58...WARMEST ALONG THE SC BEACHES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...LOVELY APRIL WEATHER ON TAP WED/THU AS POST
FRONTAL HIGH PRESSURE ENCOMPASSES THE EASTERN CAROLINAS. IF YOU
PREFER MAXIMUM TEMPERATURES IN THE 80S...THESE 2 DAYS MAY RUN A
TOUCH COOL AS WE EXPECT LOW/MID 70S...COOLEST INLAND SE NC AND
MILDEST SC INTERIOR. IF YOU LOVE SUNSHINE...BOTH DAYS WILL OFFER
THE SOUGHT AFTER STAR-RADIATION.
OFFSHORE WINDS WEDNESDAY WILL KEEP THE COLDER MARINE LAYER AT BAY
AND MOSTLY POISED OVER THE WATER...WHEREAS BY THURSDAY...WEAKENING
AND VEERING ONSHORE WINDS MAY ALLOW THE COOLER MARINE LAYER TO
BLEED INLAND. AS A RESULT WE MAY SEE SLIGHTLY WARMER CONDITIONS
ALONG THE IMMEDIATE COAST WEDNESDAY COMPARED TO THURSDAY.
TIME-HEIGHT ANALYSIS ACROSS THE REGION DEPICTS EXCEEDINGLY DRY
AIR PERCHED ABOVE 6000 FEET THROUGH LATE THURSDAY...AND NO POPS
ARE PLANNED BOTH DAYS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...THE EXTENDED LOOKS RATHER ACTIVE AS A ZONAL
MID LEVEL PATTERN WILL DEVELOP MORE AMPLITUDE IN TIME. THIS WILL
LEAD TO AN EVENTUAL CLOSED LOW MEANDERING SLOWLY ACROSS THE
MISSISSIPPI VALLEY WHICH WILL IN TURN PROVIDE GOOD ISENTROPIC LIFT
TO THE REGION AS A WARM FRONT MEANDERS BASICALLY ACROSS THE CWA.
I HAVE INCREASED POPS AND CLOUD COVER FOR THE EARLY PART OF NEXT
WEEK. FOR NOW WE DO NOT FORESEE AN EPIC RAINFALL EVENT BUT MORE OF A
NUISANCE PROLONGED PERIOD OF LIGHT RAIN. FOR THE EARLY PART OF THE
EXTENDED...FRIDAY AND THE WEEKEND A QUICK MOVING SYSTEM ASSOCIATED
WITH THE ZONAL FLOW WILL MOVE ACROSS PROVIDING POPS FOR FRIDAY. A
DRY WEEKEND IS ANTICIPATED.
REGARDING TEMPERATURES...NO WILD SWINGS WITH EARLY PERIOD
TEMPERATURES SHOWING MORE VARIABILITY WITH DAYTIME HIGHS A LITTLE
WARMER THAN USUAL WITH OVERNIGHT LOWS A BIT BELOW AVERAGE. EARLY
NEXT WEEK...THE RANGE DECREASES WITH THE INCREASE IN MOISTURE.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 19Z...MID LEVEL CIGS WILL SPREAD ACROSS OUR CWA THIS
AFTERNOON AS A COLD FRONT APPROACHES FROM THE WEST. EXPECT
SOUTHWEST WINDS TO STRENGTHEN AFTER 18Z...BECOMING 10-15 KTS WITH
HIGHER GUSTS. THE LATEST HRRR RUNS STILL DEPICT AT LEAST ISOLATED
SHOWERS DEVELOPING IN THE LATE AFTERNOON/EARLY EVENING AHEAD OF
THE COLD FRONT. WILL MAINTAIN VCSH FOR ALL TERMS...BEGINNING AT
KFLO/KLBT AROUND 21Z AND KILM/KCRE/KMYR AROUND 00Z. IT STILL LOOKS
LIKE THE INLAND TERMS HAVE THE BEST SHOT AT SEEING ANY PCPN...BUT
COVERAGE WILL BE LIMITED. WINDS WILL VEER TO THE WEST THIS EVENING
AND THEN NORTHWEST LATER TONIGHT FOLLOWING FROPA...WHICH SHOULD
OCCUR ALONG THE COAST BY 06Z. WEDNESDAY WILL BE SUNNY WITH NORTH
WINDS 10-15 KTS GUSTING TO 20 KTS AT TIMES.
EXTENDED OUTLOOK...VFR THROUGH THURSDAY. LOW CONFIDENCE FOR ISOLATED
SHOWERS/TEMPO MVFR ON FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...A COLD FRONT NOW LOCATED ACROSS EASTERN
KENTUCKY AND TENNESSEE INTO NORTHERN ALABAMA WILL MOVE EASTWARD
TONIGHT...REACHING THE CAROLINA COASTAL WATERS NEAR OR SHORTLY AFTER
MIDNIGHT. WEST-SOUTHWEST WINDS 10-15 KNOTS HAVE BEEN STRENGTHENED
NEARSHORE BY THE ADDITION OF THE DAYTIME SEABREEZE. IN FACT AT 3 PM
WINDS WERE GUSTING TO 20 KNOTS AT WRIGHTSVILLE BEACH AND 21 KNOTS AT
TOPSAIL BEACH NC. WINDS WILL VEER WESTERLY LATER THIS EVENING AS A
BROKEN LINE OF SHOWERS AND PERHAPS THUNDERSTORMS PUSH OFF THE COAST.
THIS ACTIVITY WILL BE IN ADVANCE OF THE FRONT THAT WILL VEER WINDS
MORE NORTHERLY AFTER MIDNIGHT.
SEAS CURRENTLY RANGE FROM 2.5 TO 4 FEET AT OUR LOCAL BUOYS IN A MIX
OF 9 SECOND SWELL AND A SHORT PERIOD CHOP. THE SWELL COMPONENT
SHOULD CONTINUE TO DIMINISH TONIGHT WITH COMBINED SEAS BECOMING MORE
WEIGHTED TOWARD THE SHORT PERIOD COMPONENTS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...FRISKY NW GUSTS TO 20 KT ARE POSSIBLE AT AND
SEVERAL HOURS AFTER SUNRISE WEDNESDAY IN WAKE OF A COLD FRONT. NW
WIND-SPEEDS HOWEVER ARE EXPECTED TO EASE TO AROUND 15 KT BY THE
AFTERNOON...ALTHOUGH ACROSS THE OUTER PORTION GUSTS TO 20 KT MAY
PREVAIL MUCH OF THE DAY. HIGHEST SEAS AND WINDS WILL REMAIN OVER
THE OUTER PORTION WEDNESDAY AND THURSDAY...WITH MAXIMUM SEAS NOT
MUCH HIGHER THAN 4 FEET...AND 1-2 FEET ALONG THE INSHORE WATERS.
SEAS WILL BE MAINLY COMPOSED OF ESE WAVES 1-2 FEET EVERY 8-9 SEC
AND A MODERATE NW CHOP WEDNESDAY...BECOMING A LIGHT N-NE CHOP ON
THURSDAY. MODERATE OFFSHORE WINDS WED WILL BE FOLLOWED BY EASING
AND VEERING WINDS THU.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...THE WEEKEND IS LOOKING RATHER INVITING FOR THE
MARINE COMMUNITY...THIS AFTER SOME STRONGER WINDS ASSOCIATED WITH A
QUICK MOVING FRONT FRIDAY. THESE WINDS WILL BE FROM THE SOUTHWEST IN
A RANGE OF 15-20 KNOTS. THEY WILL QUICKLY SUBSIDE TO THE WEST AT TEN
KNOTS OR LESS BY SATURDAY. THEY WILL REMAIN AT OR JUST ABOVE THIS
LEVEL UNDER A WEAK PRESSURE PATTERN THROUGH SUNDAY. SEAS GENERALLY
WILL FOLLOW THE WIND FIELDS WITH 3-4 FEET FRIDAY DROPPING SLIGHTLY
SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT TUE APR 22 2014
.SYNOPSIS...
WARM TEMPERATURES ARE EXPECTED TODAY AHEAD OF A COLD FRONT THAT WILL
MOVE THROUGH TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
WEDNESDAY...MOVING OFFSHORE THURSDAY. A BACKDOOR COLD FRONT MAY
APPROACH FROM THE NORTH OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...TWEAKED HIGH TEMPERATURE FORECASTS UP A
DEGREE IN SPOTS WITH THIS EARLY AFTERNOON UPDATE. ALSO LOOKING AT
THE 12Z MODEL GUIDANCE I AM IMPRESSED AT THE DEPICTION OF THE 500 MB
DISTURBANCE SWEEPING ACROSS THE EASTERN CAROLINAS THIS EVENING.
THERE IS EVEN A A FAVORABLY POSITIONED 300 MB JET STREAK AT 300 MB
THAT MAY BE ABLE TO ASSIST WITH CONVECTIVE VENTILATION. I JUST
EXPANDED THE REGION OF 30 POPS A LITTLE LARGER FOR THE EVENING...AND
WILL DIG DEEPER THROUGH THIS NEW SET OF MODEL GUIDANCE TO SEE IF A
LARGER EXPANSION OF SHOWER/T-STORM CHANCES NEEDS TO BE MADE FOR THE
NEXT FORECAST UPDATE. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS...
A WEAK RIDGE OF HIGH PRESSURE AT THE SURFACE MOVED OFF THE COAST
EARLY THIS MORNING. THE CAROLINAS ARE NOW IN A 500-MILE WIDE ZONE OF
WEST-SOUTHWEST SURFACE WINDS BETWEEN THE OFFSHORE RIDGE AND A COLD
FRONT NOW ACROSS MISSISSIPPI AND WESTERN TENNESSEE. THIS FRONT WILL
MOVE EASTWARD AND ACROSS THE EASTERN CAROLINAS LATE THIS
EVENING...PERHAPS ACCOMPANIED BY A BROKEN LINE OF SHOWERS AND
THUNDERSTORMS.
12Z WEATHER BALLOON DATA SHOWS THE 06Z GFS SHOWED TOO MUCH MOISTURE
BETWEEN THE SURFACE AND 700 MB ACROSS THE EASTERN CAROLINAS. THE 06Z
NAM AND RUC WERE MUCH CLOSER TO THE OBSERVED VALUES ON THE CHS AND
MHX SOUNDINGS. A BEAUTIFUL ARRAY OF SCATTERED HIGH ALTOCUMULUS
CLOUDS ARE PRODUCING VIRGA FLURRIES OVER A LARGE SECTION OF THE
COASTAL CAROLINAS THIS MORNING. VISIBLE SATELLITE SHOWS THESE SHOULD
CONTINUE FOR THE NEXT FEW HOURS BEFORE MOVING OFF TO THE NORTHEAST.
MODEL SOUNDINGS AND 12Z OBSERVED SOUNDINGS SHOW A THIN LAYER OF
MOISTURE AROUND 16000 FT AGL RESPONSIBLE FOR THIS ACTIVITY. SEE OUR
NWS ILM FACEBOOK OR TWITTER PAGE FOR A PICTURE.
MODELS SHOW A POTENTIAL FOR SCATTERED SHOWERS AND THUNDERSTORMS AS
THE FRONT APPROACHES THE EASTERN CAROLINAS LATE THIS AFTERNOON INTO
THIS EVENING. MODEL CAPE INCREASES TO 400-700 J/KG WITH MOST OF THAT
WAY UP IN THE 700-400 MB LAYER. THE LACK OF BOUNDARY LAYER
MOISTURE...PRODUCED BY THE LACK OF ANY GULF OR ATLANTIC INFLOW...
WILL PROBABLY BE THE LIMITING FACTOR REGARDING COVERAGE OF
CONVECTION. A DEEP DRY MIXED LAYER THIS AFTERNOON REACHING 7000 FEET
INLAND MEANS ANY CB CLOUD BASES ARE GOING TO BE WAY UP THERE...AND
ANY EVAPORATING PRECIPITATION WITHIN THAT DRY SUBCLOUD LAYER COULD
PRODUCE GUSTY WINDS. THIS IS PROBABLY AS CLOSE TO A CLASSIC WESTERN
UNITED STATES PATTERN AS YOU`LL SEE IN THE CAROLINAS.
BESIDES TWEAKING TIMING A LITTLE BASED ON THE LATEST SEVERAL HRRR
RUNS...I HAVE MADE NO CHANGES TO THE PREVIOUS POP DISTRIBUTION FOR
THIS EVENT: 30 POPS INLAND AND 20 AT THE COAST.
HIGHS TODAY SHOULD REACH THE LOWER 80S AWAY FROM THE BEACHES. THE
SEABREEZE WILL REMAIN PINNED TO THE SOUTH CAROLINA COAST AND SHOULD
ONLY MAKE 15-20 MILES INLAND PROGRESS ACROSS SE NORTH CAROLINA GIVEN
THE BACKGROUND WEST-SOUTHWEST WIND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...DEEP UPPER TROUGH AND SURFACE LOW OFF NEW
ENGLAND COAST ON WEDNESDAY. CLOSER TO HOME WILL BE NEARLY ZONAL FLOW
AND A WEAK PRESSURE GRADIENT. TEMPS A LITTLE BELOW CLIMO BEHIND
TUESDAY NIGHT COOL FRONT BUT THE RAPID DRYING SHOULD BRING PLENTY OF
SUNSHINE. THE CLEAR SKIES AND LIGHT WINDS WILL YIELD A PRETTY CHILLY
WEDNESDAY NIGHT WITH LOWS CLOSE TO 10 DEGREES BELOW CLIMO. DESPITE
SOME BUILDING HEIGHTS ALOFT HEADING INTO THURSDAY THE SURFACE HIGH
PUSHES IN FROM THE N AND BRINGS A VERY WEAK SENSE OF CAA. HIGHS WILL
AGAIN BE CAPPED A LITTLE BELOW CLIMO. AS THE RIDGE MOVES OFF THE
COAST THURSDAY NIGHT A LIGHT SOUTHERLY FLOW DEVELOPS THAT SHOULD
PRECLUDE AS COOL A NIGHT AS WEDNESDAY ALTHOUGH STILL BELOW CLIMO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...WARM WEATHER RETURNS ON FRIDAY AS DEVELOPING
PIEDMONT TROUGH SERVES TO ENHANCE SOUTHERLY FLOW ALONG THE COASTAL
PLAIN. IN THE STILL ZONAL MID LEVEL FLOW THERE WILL BE SOME WEAK
DISTURBANCES THAT COULD TOUCH OFF ISOLATED CONVECTION. SATURDAY
LOOKS WARM AS WELL WITH LIGHT SWRLY FLOW AND A BACKDOOR COLD FRONT
APPROACHING FROM THE N. MODELS TEND TO KEEP THIS BOUNDARY JUST FAR
ENOUGH TO THE NORTH TO PRECLUDE ANY REAL RAIN CHANCES LOCALLY BUT
THEY DO INDICATE THAT ADDED CLOUD COVER AND SUPPRESSED HEIGHTS
TEMPER THE WARMTH SUNDAY AND MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...MID LEVEL CIGS WILL SPREAD ACROSS OUR CWA THIS AFTERNOON
AS A COLD FRONT APPROACHES FROM THE WEST. EXPECT SOUTHWEST WINDS TO
STRENGTHEN AFTER 18Z...BECOMING 10-15 KTS WITH HIGHER GUSTS. THE
LATEST HRRR RUNS STILL DEPICT AT LEAST ISOLATED SHOWERS DEVELOPING
IN THE LATE AFTERNOON/EARLY EVENING AHEAD OF THE COLD FRONT. WILL
MAINTAIN VCSH FOR ALL TERMS...BEGINNING AT KFLO/KLBT AROUND 21Z AND
KILM/KCRE/KMYR AROUND 00Z. IT STILL LOOKS LIKE THE INLAND TERMS HAVE
THE BEST SHOT AT SEEING ANY PCPN...BUT COVERAGE WILL BE LIMITED.
WINDS WILL VEER TO THE WEST THIS EVENING AND THEN NORTHWEST LATER
TONIGHT FOLLOWING FROPA...WHICH SHOULD OCCUR ALONG THE COAST BY 06Z.
WEDNESDAY WILL BE SUNNY WITH NORTH WINDS 10-15 KTS GUSTING TO 20 KTS
AT TIMES.
EXTENDED OUTLOOK...VFR THROUGH THURSDAY. LOW CONFIDENCE FOR ISOLATED
SHOWERS/TEMPO MVFR ON FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...NO SIGNIFICANT CHANGES WITH THIS EARLY
AFTERNOON UPDATE. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS...
A WEAK RIDGE OF HIGH PRESSURE MOVED OFFSHORE EARLY THIS MORNING. FOR
THE REMAINDER OF THE DAY WEST-SOUTHWEST WINDS WILL SLOWLY INCREASE
IN ADVANCE OF A COLD FRONT NOW MOVING EAST ACROSS MISSISSIPPI AND
TENNESSEE. THIS FRONT SHOULD REACH THE COASTAL WATERS AFTER MIDNIGHT
TONIGHT...PERHAPS PRECEDED BY A BROKEN LINE OF SHOWERS AND
THUNDERSTORMS. THE BEST WINDOW FOR SHOWERY WEATHER APPEARS TO BE
FROM 9 PM UNTIL ABOUT 2 AM WEDNESDAY. OTHERWISE LOOK FOR A MODERATE
SEABREEZE CIRCULATION TO DEVELOP ON TOP OF THE BACKGROUND
WEST-SOUTHWEST 10-12 KNOT WIND...WITH SPEEDS NEAR THE BEACHES
INCREASING TO SOUTH-SOUTHWEST 15-17 KNOTS DURING THE LATE AFTERNOON
HOURS.
SEAS CURRENTLY RANGE FROM 2.5 TO 4 FEET ACROSS THE COASTAL WATERS. A
SMALL INCREASE IS POSSIBLE TONIGHT...ALTHOUGH IT APPEARS WE`LL
SIMPLY BE TRADING A DECREASING LONG-PERIOD SWELL FOR AN INCREASED
SHORT PERIOD WIND CHOP AS TIME GOES ON.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...OFFSHORE/NWRLY FLOW WEDNESDAY FROM BOTH
EXPANSIVE STORM OFF NEW ENGLAND COAST AND WEAK HIGH BUILDING INTO
GREAT LAKES/OH VALLEY. AS RIDGE AXIS FROM THIS HIGH POKES INTO THE
CAROLINAS FLOW WILL BECOME QUITE WEAK AND SEAS RAPIDLY DROP OFF TO
JUST 2 FT. THE CENTER OF THE HIGH MOVES OFF THE COAST BY THURSDAY
BUT REMAINS PROXIMAL ENOUGH FOR A CONTINUATION OF JUST 2 FT WAVES AS
THE FLOW ACQUIRES A SOUTHERLY COMPONENT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...SWRLY FLOW INITIALLY VERY LIGHT ON FRIDAY BUT
A DEVELOPING PIEDMONT TROUGH WILL ACT TO TIGHTEN THE GRADIENT AND
ADD PERHAPS A CATEGORY OR TWO OF WIND SPEED. EXPECTING NO HIGHER
THAN A 15-20 KT FCST WHICH WILL BE SUFFICIENT FOR 2-4FT WAVES. THIS
TROUGH MOVES OFF THE COAST AND WASHES OUT ON SATURDAY ONCE AGAIN
RELAXING THE GRADIENT AND PERHAPS DROPPING A FOOT OFF THE HIGH END
OF THE SIG WAVE FCST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB/TRA
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1023 AM EDT TUE APR 22 2014
.SYNOPSIS...
WARM TEMPERATURES ARE EXPECTED TODAY AHEAD OF A COLD FRONT THAT WILL
MOVE THROUGH TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
WEDNESDAY...MOVING OFFSHORE THURSDAY. A BACKDOOR COLD FRONT MAY
APPROACH FROM THE NORTH OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...A WEAK RIDGE OF HIGH PRESSURE AT THE SURFACE
MOVED OFF THE COAST EARLY THIS MORNING. THE CAROLINAS ARE NOW IN A
500-MILE WIDE ZONE OF WEST-SOUTHWEST SURFACE WINDS BETWEEN THE
OFFSHORE RIDGE AND A COLD FRONT NOW ACROSS MISSISSIPPI AND WESTERN
TENNESSEE. THIS FRONT WILL MOVE EASTWARD AND ACROSS THE EASTERN
CAROLINAS LATE THIS EVENING...PERHAPS ACCOMPANIED BY A BROKEN LINE
OF SHOWERS AND THUNDERSTORMS.
12Z WEATHER BALLOON DATA SHOWS THE 06Z GFS SHOWED TOO MUCH MOISTURE
BETWEEN THE SURFACE AND 700 MB ACROSS THE EASTERN CAROLINAS. THE 06Z
NAM AND RUC WERE MUCH CLOSER TO THE OBSERVED VALUES ON THE CHS AND
MHX SOUNDINGS. A BEAUTIFUL ARRAY OF SCATTERED HIGH ALTOCUMULUS
CLOUDS ARE PRODUCING VIRGA FLURRIES OVER A LARGE SECTION OF THE
COASTAL CAROLINAS THIS MORNING. VISIBLE SATELLITE SHOWS THESE SHOULD
CONTINUE FOR THE NEXT FEW HOURS BEFORE MOVING OFF TO THE NORTHEAST.
MODEL SOUNDINGS AND 12Z OBSERVED SOUNDINGS SHOW A THIN LAYER OF
MOISTURE AROUND 16000 FT AGL RESPONSIBLE FOR THIS ACTIVITY. SEE OUR
NWS ILM FACEBOOK OR TWITTER PAGE FOR A PICTURE.
MODELS SHOW A POTENTIAL FOR SCATTERED SHOWERS AND THUNDERSTORMS AS
THE FRONT APPROACHES THE EASTERN CAROLINAS LATE THIS AFTERNOON INTO
THIS EVENING. MODEL CAPE INCREASES TO 400-700 J/KG WITH MOST OF THAT
WAY UP IN THE 700-400 MB LAYER. THE LACK OF BOUNDARY LAYER
MOISTURE...PRODUCED BY THE LACK OF ANY GULF OR ATLANTIC INFLOW...
WILL PROBABLY BE THE LIMITING FACTOR REGARDING COVERAGE OF
CONVECTION. A DEEP DRY MIXED LAYER THIS AFTERNOON REACHING 7000 FEET
INLAND MEANS ANY CB CLOUD BASES ARE GOING TO BE WAY UP THERE...AND
ANY EVAPORATING PRECIPITATION WITHIN THAT DRY SUBCLOUD LAYER COULD
PRODUCE GUSTY WINDS. THIS IS PROBABLY AS CLOSE TO A CLASSIC WESTERN
UNITED STATES PATTERN AS YOU`LL SEE IN THE CAROLINAS.
BESIDES TWEAKING TIMING A LITTLE BASED ON THE LATEST SEVERAL HRRR
RUNS...I HAVE MADE NO CHANGES TO THE PREVIOUS POP DISTRIBUTION FOR
THIS EVENT: 30 POPS INLAND AND 20 AT THE COAST.
HIGHS TODAY SHOULD REACH THE LOWER 80S AWAY FROM THE BEACHES. THE
SEABREEZE WILL REMAIN PINNED TO THE SOUTH CAROLINA COAST AND SHOULD
ONLY MAKE 15-20 MILES INLAND PROGRESS ACROSS SE NORTH CAROLINA GIVEN
THE BACKGROUND WEST-SOUTHWEST WIND.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...DEEP UPPER TROUGH AND SURFACE LOW OFF NEW
ENGLAND COAST ON WEDNESDAY. CLOSER TO HOME WILL BE NEARLY ZONAL FLOW
AND A WEAK PRESSURE GRADIENT. TEMPS A LITTLE BELOW CLIMO BEHIND
TUESDAY NIGHT COOL FRONT BUT THE RAPID DRYING SHOULD BRING PLENTY OF
SUNSHINE. THE CLEAR SKIES AND LIGHT WINDS WILL YIELD A PRETTY CHILLY
WEDNESDAY NIGHT WITH LOWS CLOSE TO 10 DEGREES BELOW CLIMO. DESPITE
SOME BUILDING HEIGHTS ALOFT HEADING INTO THURSDAY THE SURFACE HIGH
PUSHES IN FROM THE N AND BRINGS A VERY WEAK SENSE OF CAA. HIGHS WILL
AGAIN BE CAPPED A LITTLE BELOW CLIMO. AS THE RIDGE MOVES OFF THE
COAST THURSDAY NIGHT A LIGHT SOUTHERLY FLOW DEVELOPS THAT SHOULD
PRECLUDE AS COOL A NIGHT AS WEDNESDAY ALTHOUGH STILL BELOW CLIMO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...WARM WEATHER RETURNS ON FRIDAY AS DEVELOPING
PIEDMONT TROUGH SERVES TO ENHANCE SOUTHERLY FLOW ALONG THE COASTAL
PLAIN. IN THE STILL ZONAL MID LEVEL FLOW THERE WILL BE SOME WEAK
DISTURBANCES THAT COULD TOUCH OFF ISOLATED CONVECTION. SATURDAY
LOOKS WARM AS WELL WITH LIGHT SWRLY FLOW AND A BACKDOOR COLD FRONT
APPROACHING FROM THE N. MODELS TEND TO KEEP THIS BOUNDARY JUST FAR
ENOUGH TO THE NORTH TO PRECLUDE ANY REAL RAIN CHANCES LOCALLY BUT
THEY DO INDICATE THAT ADDED CLOUD COVER AND SUPPRESSED HEIGHTS
TEMPER THE WARMTH SUNDAY AND MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS TAF
PERIOD. INCREASING MID TO HIGH CLOUDS CAN BE SEEN ON SATELLITE
IMAGERY THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. LIGHT
SOUTHWEST WINDS EARLY WILL STRENGTHEN TO 10-15 KTS THIS AFTERNOON.
VFR CIGS WILL DEVELOP FROM WEST TO EAST LATER TODAY AS THE FRONT
ENTERS THE CAROLINAS. HAVE MAINTAINED VCSH FOR ALL TERMS...BEGINNING
WITH KFLO/KLBT BY MID-AFTERNOON...AS ISOLATED SHOWERS MAY DEVELOP
AHEAD OF THE BOUNDARY. COVERAGE SHOULD BE LIMITED WITH THE BEST
CHANCES FOR A BRIEF SHOWER AT THE INLAND TERMS. WINDS WILL VEER TO
THE WEST THIS EVENING AND THEN NORTHWEST OVERNIGHT FOLLOWING FROPA.
BY 06Z...THE FRONT SHOULD BE AT OR JUST THROUGH THE COASTAL TERMS AS
MID LEVEL DRYING RESULTS IN MOSTLY CLEAR CONDITIONS THROUGH THE END
OF THE PERIOD.
EXTENDED OUTLOOK...VFR THROUGH THURSDAY. LOW CONFIDENCE FOR ISOLATED
SHOWERS/TEMPO MVFR ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...A WEAK RIDGE OF HIGH PRESSURE MOVED OFFSHORE
EARLY THIS MORNING. FOR THE REMAINDER OF THE DAY WEST-SOUTHWEST
WINDS WILL SLOWLY INCREASE IN ADVANCE OF A COLD FRONT NOW MOVING
EAST ACROSS MISSISSIPPI AND TENNESSEE. THIS FRONT SHOULD REACH THE
COASTAL WATERS AFTER MIDNIGHT TONIGHT...PERHAPS PRECEDED BY A BROKEN
LINE OF SHOWERS AND THUNDERSTORMS. THE BEST WINDOW FOR SHOWERY
WEATHER APPEARS TO BE FROM 9 PM UNTIL ABOUT 2 AM WEDNESDAY.
OTHERWISE LOOK FOR A MODERATE SEABREEZE CIRCULATION TO DEVELOP ON
TOP OF THE BACKGROUND WEST-SOUTHWEST 10-12 KNOT WIND...WITH SPEEDS
NEAR THE BEACHES INCREASING TO SOUTH-SOUTHWEST 15-17 KNOTS DURING
THE LATE AFTERNOON HOURS.
SEAS CURRENTLY RANGE FROM 2.5 TO 4 FEET ACROSS THE COASTAL WATERS. A
SMALL INCREASE IS POSSIBLE TONIGHT...ALTHOUGH IT APPEARS WE`LL
SIMPLY BE TRADING A DECREASING LONG-PERIOD SWELL FOR AN INCREASED
SHORT PERIOD WIND CHOP AS TIME GOES ON.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...OFFSHORE/NWRLY FLOW WEDNESDAY FROM BOTH
EXPANSIVE STORM OFF NEW ENGLAND COAST AND WEAK HIGH BUILDING INTO
GREAT LAKES/OH VALLEY. AS RIDGE AXIS FROM THIS HIGH POKES INTO THE
CAROLINAS FLOW WILL BECOME QUITE WEAK AND SEAS RAPIDLY DROP OFF TO
JUST 2 FT. THE CENTER OF THE HIGH MOVES OFF THE COAST BY THURSDAY
BUT REMAINS PROXIMAL ENOUGH FOR A CONTINUATION OF JUST 2 FT WAVES AS
THE FLOW ACQUIRES A SOUTHERLY COMPONENT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...SWRLY FLOW INITIALLY VERY LIGHT ON FRIDAY BUT
A DEVELOPING PIEDMONT TROUGH WILL ACT TO TIGHTEN THE GRADIENT AND
ADD PERHAPS A CATEGORY OR TWO OF WIND SPEED. EXPECTING NO HIGHER
THAN A 15-20 KT FCST WHICH WILL BE SUFFICIENT FOR 2-4FT WAVES. THIS
TROUGH MOVES OFF THE COAST AND WASHES OUT ON SATURDAY ONCE AGAIN
RELAXING THE GRADIENT AND PERHAPS DROPPING A FOOT OFF THE HIGH END
OF THE SIG WAVE FCST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB/TRA
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1143 PM CDT MON APR 21 2014
.UPDATE...
ISSUED AT 1142 PM CDT MON APR 21 2014
SOME MOISTURE HAS BEEN POOLING IN THE NORTHERN RED RIVER VALLEY
FOR THE PAST FEW HOURS AND DEW POINT DEPRESSIONS HAVE BEEN
DECREASING. THIS ALONG WITH LIGHT WINDS...COULD BRING THE THREAT
OF FOG FORMATION AND THE HRRR AND RAP DO SHOW SOME SIGNS OF THIS.
HOWEVER...MID LEVEL CLOUDS HAVE CONTINUED TO HANG ON LONGER THAN
EXPECTED OVER THE AREA AND CIRRUS IS STARTING TO MOVE IN FROM THE
WEST. WILL LEAVE OUT ANY FOG MENTION FOR NOW AND JUST KEEP AN EYE
ON THINGS. TEMPS WILL CONTINUE TO DROP INTO THE MID TO LOW 30S
OVERNIGHT.
UPDATE ISSUED AT 941 PM CDT MON APR 21 2014
CLOUDS ARE SLOWLY DIMINISHING OVER THE NORTH CENTRAL COUNTIES AS
EXPECTED AFTER WE LOST DAYTIME HEATING. THAT TREND SHOULD CONTINUE
AND WE WILL SEE CLEAR SKIES AND LIGHT WINDS AS HIGH PRESSURE
BUILDS INTO THE AREA. THINK THAT TEMPS WILL CONTINUE TO FALL
THROUGH THE 40S AND DOWN INTO THE 30S BY MORNING.
UPDATE ISSUED AT 652 PM CDT MON APR 21 2014
ADJUSTED CLOUD COVER A TAD THIS EVENING AS SOME MID LEVEL CLOUDS
HAVE BEEN MOVING INTO THE NORTHERN CWA. THINK THAT THE CLOUDS
SHOULD DISSIPATE AFTER SUNSET...LEAVING MOSTLY CLEAR SKIES. KEEP
TEMPS ON TRACK TO BOTTOM OUT IN THE 30S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 316 PM CDT MON APR 21 2014
MAIN FORECAST CHALLENGE WILL BE PCPN CHANCES STARTING TUE NIGHT.
MODELS COMING INTO BETTER AGREEMENT WITH EACH RUN REGARDING THIS
SYSTEM SO FORECAST CONTINUITY PRETTY GOOD OVERALL. AS OF LATE
THIS AFTERNOON THE STRATOCUMULUS FIELD CONTINUED TO THIN ACROSS
NORTHWEST MN. NORTHWEST WINDS REMAIN RATHER GUSTY BUT WITH SFC
HIGH BUILDING INTO THE FA THEY WILL CONTINUE TO DROP LATE THIS
AFTERNOON INTO THE EARLY EVENING. THE SFC HIGH WILL MOVE INTO THE
EASTERN FA TOWARD TUE MORNING BRINGING LIGHT WINDS AND MOSTLY
CLEAR SKIES FOR MOST OF THE NIGHT. THIS WILL RESULT IN ANOTHER
COOL MORNING WITH TEMPS ON EITHER SIDE OF FREEZING. SHOULD SEE
QUITE A BIT OF SUN ON TUE ESPECIALLY OVER THE MN FA WITH A
TIGHTENING PRESSURE GRADIENT OVER ND. STRONG 850MB WARM ADVECTION
AND WIND GET GOING TUE NIGHT. MODELS OFF SLIGHTLY ON THE MAIN AXIS
OF PCPN WITH THE 12Z GFS MORE EAST-WEST AND FURTHEST EAST. ITS
850MB WINDS ARE MORE FRAGMENTED WITH ONE SEGMENT POINTING INTO
SOUTHEAST ND BY 12Z WED. OTHER MODELS HAVE THE WINDS A LITTLE
FURTHER WEST WITH THE MAIN PCPN BAND SETTING UP IN THAT PATTERN.
LIKE THIS IDEA FOR NOW AS IT DOES MATCH WHAT WE HAVE BEEN
FORECASTING. INSTABILITY LOOKS WEAKER ON THE 12Z RUNS SO WILL KEEP
THINGS MOSTLY AS SHOWERS FOR NOW AND SEE IF LATER RUNS CHANGE THIS
IDEA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 316 PM CDT MON APR 21 2014
STILL CONTINUE WITH THE SHOWERS FOR WED AND WED NIGHT...GRADUALLY
PUSHING THEM FROM EASTERN ND INTO THE NORTHWEST QUARTER OF MN.
LOOKS QUITE WINDY ON WED WITH SOUTHEAST WINDS. SOME DRYING MAY
WORK INTO THE FA ON THU MORNING BUT THIS LOOKS TO FILL BACK IN
WITH SHOWERS BY THU AFTERNOON. AS FAR AS TOTAL PCPN AMOUNTS STILL
LOOKING AT A HALF TO THREE QUARTERS OF AN INCH IN THE HEAVIER BAND.
FOR THU NIGHT THROUGH MONDAY...GFS AND ECMWF SHOWING CLOSE AGREEMENT
ON TRANSITION FROM THE MIDWEEK LARGE SCALE...MOIST NORTHERN PLAINS
LOW PRESSURE SYSTEM TO A PREDOMINANTLY DRY SURFACE HIGH PRESSURE
SYSTEM FOR THE WEEKEND... WITH FRIDAY MORNING AS THE TRANSITION
PERIOD. THUS KEPT A FAIRLY LOW /CHC/ POP AND LOW QPF MIX OF RAIN
AND SNOW EARLY FRIDAY MORNING. FRIDAY PM THROUGH MONDAY... THE NP
AREA APPEARS STUCK UNDER AN H5 OMEGA BLOCK WITH DRY SFC HIGH
PRESSURE PUSHING DOWN FROM NORTHWESTERN ONTARIO. IF THIS HOLDS...
AT THIS TIME OF YEAR THAT TYPICALLY MEANS SOME VERY LOW DEW POINTS
AND VERY DRY AIR IS POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CDT MON APR 21 2014
CONDITIONS WILL REMAIN VFR WITH ONLY A FEW MID LEVEL AND CIRRUS
CLOUDS OVER THE AREA THROUGH TONIGHT AND TOMORROW. LIGHT AND
VARIABLE WINDS WILL PICK UP OUT OF THE SOUTHEAST TOMORROW
AFTERNOON AS LOW PRESSURE APPROACHES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/GUST
AVIATION...JR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
516 PM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL CLEAR CENTRAL PENNSYLVANIA THIS EVENING...ENDING
ANY LINGERING SHOWER OR THUNDERSTORM ACTIVITY BY EARLY TO MID
EVENING. MUCH COLDER AIR WILL WORK INTO THE COMMONWEALTH LATER
TONIGHT AND WEDNESDAY...WITH LAKE EFFECT SNOW SHOWERS OVER THE
NORTHWEST AND WEST CENTRAL MOUNTAINS AND FLURRIES POSSIBLE OVER
THE REST OF THE CENTRAL AND NORTHERN MOUNTAINS. COOL AND DRY
WEATHER IS EXPECTED TO CONTINUE THURSDAY...AS A RIDGE OF HIGH
PRESSURE SLIDES OVER THE AREA. THE NEXT COLD FRONT AND CHANCE FOR
SHOWERS WILL ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MID LVL SHORTWAVE AND ASSOC SFC COLD FRONT PUSHING THRU CENTRAL PA
THIS EVENING...ACCOMPANIED BY A FAIRLY SOLID LINE OF SHOWERS AND
TSRA. THE TSRA ARE CONCENTRATED PRIMARILY ACROSS THE LAUREL
HIGHLANDS...WHERE 20Z SPC MESOANALYSIS SHOWS CAPES ARND 500 J/KG.
MARGINAL INSTABILITY WILL LIMIT THE SVR THREAT. HOWEVER...SMALL
HAIL ALREADY REPORTED ARND JOHNSTOWN AND RAP DATA SHOWS FAIRLY
STRONG WINDS BTWN 1-3KM...WHICH COULD EASILY MIX TO THE SFC IN
STRONGER CONVECTIVE CELLS. COLD FRONT AND ASSOC CONVECTION SHOULD
PASS EAST OF THE CWA ARND OR SHORTLY AFTER 00Z.
MUCH COLDER AIR DIVES INTO WEST CENTRAL PA BY 00Z WED...WITH 850
MB READINGS PLUNGING BELOW ZERO. GUSTY POST-FRONTAL WNW FLOW WILL
INCREASE THROUGH WEDNESDAY AND HELP DIRECT AN ABNORMALLY COOL
CANADIAN AIRMASS INTO THE AREA WHICH WILL LAST THROUGH THURSDAY
MORNING.
WELL ALIGNED NW FLOW WILL COMBINE WITH 850 MB TEMPS FALLING TO
AROUND -3 TO -4C TONIGHT TO BRING SCATTERED SNOW SHOWERS TO THE NW
MTNS AND LAURELS OVERNIGHT TONIGHT...WITH A LIGHT COATING POSSIBLE
AT ELEVATIONS GENERALLY AOA 1500 FT MSL. A FEW FLURRIES WILL
LIKELY SPILL OFF THE ALLEGHENY FRONT AND INTO THE CENTRAL RIDGE
AND VALLEY REGION AFTER MIDNIGHT TONIGHT.
LOW TEMPS TONIGHT WILL VARY FROM THE LOWER TO MID 30S ACROSS THE
MOUNTAINS...TO BETWEEN 40-45F THROUGHOUT THE SUSQ VALLEY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
STRATOCU WILL LINGER ACROSS THE NRN AND WESTERN MTNS FOR
WEDNESDAY WITH SCATTERED MAINLY MORNING SNOW SHOWERS /MIXED WITH
RAIN IN THE VALLEYS/...WHILE MOSTLY SUNNY SKIES DEVELOP ACROSS THE
LOWER SUSQ VALLEY. VRBL AMOUNTS OF STRATO CU WILL OCCUR ACROSS THE
CENTRAL RIDGE AND VALLEY REGION. IT WILL BE BREEZY TO LOCALLY
WINDY WITH SUSTAINED WINDS OF 12 TO 18 MPH AND GUSTS TO 30 MPH
IN THE AFTERNOON. HIGH TEMPS ON WEDNESDAY /IN THE MID AND UPPER
40S ACROSS THE NW MTNS AND LAURELS...AND UPPER 50S TO AROUND 60 IN
THE SE/ WILL AVG 5-10 DEGREES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
WILL KEEP THIS SHORT...WATCHING LOW TOPPED STORMS ON RADAR.
SOME SMALL HAIL REPORTED SW OF OUR AREA.
ANYWAY...NOT MANY CHANGES FROM RECENT DAYS.
AIRMASS QUITE COLD FOR WED...THUS DID LOWER TEMPS WED
NIGHT SOME.
LOOKING AT A SUNNY BUT BREEZY DAY ON THU...AS A LARGE
STORM SYSTEM REMAINS JUST OFFSHORE.
STILL LOOKING AT SHOWERS ON FRIDAY...WITH THE NEXT SYSTEM.
DID NOT ADD THUNDER AT THIS POINT...AS THE TRIPLE POINT LOOKS
TO BE JUST SOUTH OF CENTRAL PA. TEMPS WILL BE ON THE MILD
SIDE...GIVEN WARM ADVECTION AND TEMPS AT 850 MB.
DID CUT BACK ON SHOWERS FOR SATURDAY NIGHT...GIVEN NW
FLOW AND SPREAD IN MODELS.
WENT WITH A DRY FORECAST FOR SUNDAY INTO MONDAY.
HOWEVER...DID LOWER TEMPS SOME MONDAY...GIVEN THE
AIRMASS IN PLACE AND NE TO SE FLOW.
LARGE CUTOFF TO THE SW NEXT WEEK WITH A REX BLOCK.
THERE COULD BE SOME SHOWERS LATE TUE. POTENTIAL FOR
A SEVERAL DAY PERIOD OF WET AND COOL WEATHER.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A STRONG COLD FRONT WILL PUSH EAST ACROSS THE STATE DURING THE MID
TO LATE AFTERNOON. ISOLATED THUNDER WILL ACCOMPANY THE FRONT...
WITH WINDS TURNING TO THE NW AS THEY INCREASE AND BECOME GUSTY.
BEHIND THE FRONT...CIGS WILL REMAIN LOW THROUGH MID TO LATE
EVENING.
MVFR/IFR CONTINUES INTO WED IN WEST AND NORTH...WITH A BREEZY NW
WIND.
OUTLOOK...
TONIGHT-WED...MVFR NORTH/WEST WITH SCT -SHRA...VFR ELSEWHERE.
BREEZY NW WINDS.
THU...VFR. NO SIG WX.
FRI...MVFR WITH CHC SHRA.
SAT-SUN.
&&
.FIRE WEATHER...
MIN RHS DROP TO THE UPPER 20S ACROSS PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY WEDNESDAY AFTERNOON. WNW
WINDS OF 12 TO 18 MPH WITH GUSTS TO 30 MPH ARE EXPECTED ALONG
WITH FINE FUEL MOISTURES IN THE UPPER SINGLE DIGIT PERCENTILES.
THROUGH COLLABORATION WITH BOF OFFICIALS AND SURROUNDING NWS
OFFICES...HAVE ISSUED FIRE WEATHER WATCH FROM 15Z WED TO 00Z THU
FROM BEDFORD COUNTY EASTWARD TO LANCASTER COUNTY AND NORTHWARD
TO PERRY...DAUPHIN AND LEBANON COUNTIES ON WEDNESDAY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR PAZ034>036-056-057-059-063>066.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR
FIRE WEATHER...
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
COLD FRONT IS SLOWLY WORKING ITS WAY EAST ACROSS WESTERN SD AND IS
APPROACHING THE WESTERN FRINGE OF THE CWA. AHEAD OF THE
FRONT...STRONG SOUTHEAST WINDS CONTINUE...WELL INTO ADVISORY
LEVELS FOR MANY LOCATIONS. ALTHOUGH...AS PRESSURE GRADIENT RELAXES
A BIT WITH THE APPROACH OF THE SFC TROUGH...WE ARE SEEING A SUBTLE
AND SLOW DROP OFF IN SPEEDS OUT OF CRITERIA LEVELS FROM WEST TO
EAST. WILL LET THE JAMES VALLEY PORTION OF THE WIND ADVISORY
EXPIRE AT 21Z WITH THE REMAINING EASTERN AREA GOING UNTIL 00Z.
ASIDE FROM THE WIND...ALSO DEALING WITH SCT SHOWERS AHEAD OF THE
FRONT. AS WAS SUGGESTED BY THE HRRR AND OTHER HI RES MODELS...WE
ARE SEEING A BIT OF REDEVELOPMENT ALONG AND EAST OF THE MISSOURI
RIVER. SO...EXPECTING DECENT CHANCES FOR PRECIP YET THIS AFTERNOON
AND INTO THE EVENING HOURS BEFORE COLD FRONT SCOURS OUT MOST OF
THE AVAILABLE MOISTURE.
NEXT AREA OF CONCERN IS THE CRITICAL FIRE DANGER ON THURSDAY.
BEHIND THE COLD FRONT...DRY AIR MOVES BACK INTO THE REGION ALONG
WITH BREEZY NORTHWEST WINDS GUSTING OVER 30 MPH. MIN RH VALUES ARE
EXPECTED TO FALL CLOSE TO 20 PERCENT IN THE JAMES VALLEY WITH
VALUES LIKELY GOING BELOW 20 PERCENT ACROSS CENTRAL/SOUTH CENTRAL
SD. HAVE THEREFORE UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG
WARNING EFFECTIVE FROM 18Z TO 00Z TOMORROW.
TEMPS STAY MILD THROUGH THE SHORT TERM...AND THERE HAS BEEN AN
UPWARD TREND IN TEMPS ON FRIDAY. GFS IS STILL STUBBORN IN BRINGING
COOLER TEMPS AT 850 MB INTO THE NORTHERN/EASTERN CWA DURING THE
DAY FRIDAY...SHOWING A BIT MORE INFLUENCE OF THE COOLER HIGH TO THE
NORTH. THIS REALLY IS NOT SUPPORTED BY OTHER MODELS THOUGH SO HAVE
GONE WITH THE WARMER SOLUTIONS SEEN IN THE EC AND GEM.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
THE MODELS SHOW GOOD AGREEMENT IN THE LONG TERM WITH A MAINLY WET
AND COOL PATTERN FROM SATURDAY THROUGH MONDAY NIGHT. THE MODELS
SHOW A SURFACE LOW PRESSURE AREA INTENSIFYING IN EASTERN COLORADO
THROUGH SATURDAY AFTERNOON. THIS SURFACE LOW PRESSURE AREA THEN
WOBBLES AND MOVES SLOWLY EAST AND SOUTHEAST ACROSS THE CENTRAL
PLAINS THROUGH MONDAY NIGHT. DEEP AND MOIST EAST TO SOUTHEAST FLOW
NORTH OF THE LOW PRESSURE AREA WILL BRING MAINLY RAIN TO MUCH OF
OUR CWA STARTING SATURDAY AFTERNOON. THE CHANCES OF RAIN CONTINUE
TO BE GOOD THROUGH MONDAY NIGHT. IT LOOKS LIKE MUCH OF THE CWA
WILL GET SOME DECENT RAINFALL ACCUMULATIONS WITH THIS SYSTEM.
OTHERWISE...THE SYSTEM WILL SLOWLY PUSH OUT FOR TUESDAY AND
WEDNESDAY WITH COOL CANADIAN SURFACE HIGH PRESSURE BUILDING IN.
WITH THE RAIN...CLOUDS AND CANADIAN AIR TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE ENTIRE LONG TERM. HIGHS WILL BE MOSTLY
IN THE 40S AND 50S THROUGH THE PERIOD.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PRECIPITATION CHANCES ARE BASICALLY DONE AT KPIR/KMBG AND KABR.
HOWEVER...LATER TONIGHT INTO EARLY THURSDAY MORNING...ANOTHER
PIECE OF LOW PRESSURE ENERGY COULD POTENTIALLY GENERATE SOME LIGHT
PRECIPITATION AT THE KATY TERMINAL.
MEANWHILE...WEST OF THE COLD FRONT /KPIR AND KMBG/ THAT IS SLOWING
DOWN RIGHT NOW...VFR CONDITIONS SHOULD PREVAIL OVER THE NEXT 24
HOURS. EAST OF THE COLD FRONT KABR AND KATY...BUT ESPECIALLY
KATY...WILL SEE VFR CONDITIONS DETERIORATE INTO MVFR AND POSSIBLY
IFR STRATUS AND FOG FROM LATE THIS EVENING THROUGH LATE THURSDAY
MORNING. EVENTUALLY...THE COLD FRONT WILL PUSH EAST OF KABR AND
KATY DRYING THINGS OUT AS BREEZY WEST-NORTHWEST WINDS DEVELOP.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 7 PM CDT /6 PM MDT/
THURSDAY FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER CHEYENNE-
UPPER JAMES RIVER-UPPER MISSOURI COTEAU.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
909 PM CDT WED APR 23 2014
.UPDATE...
SEE EVENING UPDATE.
&&
.DISCUSSION...
NOT MANY CHANGES PLANNED FOR THE EVENING UPDATE. AT 01Z...A DEEP
SURFACE LOW PRESSURE SYSTEM WAS LOCATED OVER WESTERN KANSAS WITH A
WEAK TROUGH AXIS EXTENDING S-SW. THE PRESSURE GRADIENT IS FAIRLY
TIGHT SO NOT EXPECTING WINDS TO DECOUPLE OVERNIGHT. WINDS JUST OFF
THE SURFACE ARE ALSO ROBUST SO FEEL FOG THREAT IS LESS THAN LAST
NIGHT. STORMS ARE FIRING ALONG THE SFC TROUGH AND THESE STORMS
WILL STAY WEST OF THE REGION BUT THEY WILL SEND A THICK CIRRUS
SHIELD THIS WAY. LOW CLOUDS WILL ALSO BE ON THE INCREASE OVERNIGHT
SO BETWEEN THE TWO CLOUD DECKS...FEEL THERMAL INSULATION WILL
KEEP MIN TEMPS A LITTLE WARMER THAN LAST COUPLE OF NIGHTS. TWEAKED
MIN TEMP GRIDS A BIT.
ON THURSDAY...A WEAK S/WV WILL MOVE EAST ACROSS NORTH TEXAS. FCST
SOUNDINGS SUGGEST A STRONG CAPPING INVERSION WILL REMAIN IN PLACE.
THE TEXAS TECH 3 KM WRF AND THE RAP DEVELOP SOME CONVECTION OVER
CENTRAL TEXAS AND MOVE THIS AREA ACROSS SE TX AROUND 18Z. THE
ECMWF IS QUITE BULLISH WITH POPS OVER THE NE PART OF THE AREA
DURING THE AFTN. THE ECMWF HAS THE BEST JET DYNAMICS AS WELL WITH
A SPLITTING JET AND A RRQ. 00Z NAM12 STILL KEEPING THE AREA CAPPED
ON THURSDAY. THINK THE CURRENT FCST WITH 20 POPS OVER THE NORTH
IS STILL VALID. NEW ZONES OUT BY 915 PM. 43
&&
.PREV DISCUSSION... /ISSUED 626 PM CDT WED APR 23 2014/
DISCUSSION...
GOOD MOISTURE ADVECTION COUPLED WITH A TIGHT PRESSURE GRADIENT AND
A LOW-LEVEL INVERSION WILL LEAD TO THE WINDS STAYING UP AND AN IFR
LAYER FORMING TONIGHT. THE TIME PERIOD FORECASTED BY THE MODELS
FOR IFR WAS BETWEEN 09Z AND 14Z...ALTHOUGH THE MOISTURE LAYER WILL
BE FAIRLY SHALLOW. THE INVERSION SHOULD BREAK AND ALLOW FOR MIXING
TO SCATTER OUT THE CLOUD DECK MID MORNING THURSDAY. LIKED THE GFS
IN BRINGING IN CHANCES FOR ISOLATED THUNDERSTORMS TO KCXO...
KCLL...AND KUTS THURSDAY AFTERNOON. FOR NOW WENT WITH A VCTS
MENTION AT ALL THREE SITES.
40
PREV DISCUSSION... /ISSUED 349 PM CDT WED APR 23 2014/
DISCUSSION...
WARM AFTERNOON ACROSS THE REGION TODAY (83-88 INLAND) WITH MOIST
S-SE FLOW IN PLACE. UPPER RIDGING OVER THE AREA THIS MORNING WILL
CONTINUE TO SLIDE EAST TONIGHT WITH A LARGE UPPER TROUGH OVER THE
WESTERN HALF OF THE COUNTRY. THIS UPPER TROUGH WILL LIFT NORTHEAST
INTO THE PLAINS AND S/W ENERGY ROTATES UP OVER THE RED RIVER WHICH
WILL PROBABLY BE TOO FAR NORTH FOR SETX TO MUCH IN THE WAY OF
RAINFALL EXCEPT PERHAPS THE FAR NORTH THURSDAY. THE ASSOCIATED
MILD PACIFIC COLD FRONT SWINGS INTO THE NORTHERN CWA LATE THURSDAY
AND STALLS WITH A GOOD CAP IN PLACE. WHICH SHOULD BRING SOME DRIER
AIR ALBEIT BRIEFLY BEFORE SE TO SOUTH FLOW INCREASES.
THIS MOIST FLOW WILL LIKELY LEAD TO A ROUND OF WIDESPREAD STRATUS
AND POSSIBLY SOME PATCHY FOG TONIGHT AND AGAIN FRIDAY WITH FOG
THREAT A LITTLE GREATER FRIDAY WITH DRIER AIR IN THE NORTH AND
NOTICEABLE DEWPOINT GRADIENT ACROSS THE AREA WITH GREATER
RADIATIONAL COOLING POTENTIAL.
SATURDAY WARM AND MOIST AND AS NEXT TROUGH MOVES INTO NM SUNDAY
MORNING RAIN CHANCES INCREASE WITH LLJ OVERHEAD AND NEARLY
SPLITTING UPPER JET BUT MAY BE TOO CAPPED. BY MONDAY MORNING THE
PACIFIC FRONT IS PUSHING EAST INTO THE REGION AND INCREASING PVA
AND SLIGHTLY MORE FAVORABLE UPPER JET MAY GIVE THE AREA THE BEST
CHANCE OF RAIN BUT FOR NOW WILL KEEP IT AT 30 NORTH EARLY THEN
TAPERING DOWN TO 20S BY AFTERNOON. STILL PLENTY OF TIME FOR MODELS
TO FLIP FLOP ON TIMING AND TRACK OF THE UPPER LOW (WHICH MAY BE
FURTHER NORTH). DRY AIR WRAPS AROUND AS FRONT PUSHES THROUGH
TUESDAY AND SLIGHTLY COOLER WEATHER (AROUND NORMAL TO JUST
SLIGHTLY BELOW NORMAL) SHOULD PREVAIL WED/THU/FRI.
45
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THROUGH THE END OF
THE WEEK. WINDS AND SEAS WILL BEGIN TO BUILD THIS WEEKEND AS THE
PRESSURE GRADIENT TIGHTENS ACROSS THE STATE. CAUTION FLAGS ARE
POSSIBLE AS EARLY AS SATURDAY AFTERNOON WITH ADVISORY CONDITIONS
LIKELY BY SUNDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 85 65 85 66 / 20 20 10 10 10
HOUSTON (IAH) 65 84 66 84 67 / 10 10 10 10 10
GALVESTON (GLS) 69 76 68 78 69 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1141 PM CDT MON APR 21 2014
.AVIATION...
VFR THROUGH THE PERIOD WITH AN UPPER LEVEL HIGH PRESSURE RIDGE
PASSING OVERHEAD. WEAK SURFACE RIDGE WILL BE REPLACED BY DEEPENING
SURFACE TROUGH AND MODEST SOUTHEAST LOW LEVEL FLOW TUESDAY. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 756 PM CDT MON APR 21 2014/
UPDATE...
ADDED ISOLATED THUNDER TO NORTHWEST COUNTIES AS A WEAK IMPULSE
WITH MODEST MID LEVEL MOISTURE WAS EDGING SOUTHEAST INTO THE AREA.
LATEST HRRR CONTINUES TO GENERATE ISOLATED WEAK CONVECTION ACROSS
OUR NORTHWEST ZONES FOR THE NEXT COUPLE HOURS. EXPECT ONLY LIGHT
RAINFALL. THESE HAVE DONE WELL JUST TO ARRIVE WITHIN A FAIRLY COOL
AND DRY AIRMASS WITH BUILDING HEIGHTS ALOFT...SO HAVE EARNED
AMENDED FORECAST STATUS. RMCQUEEN
PREV DISCUSSION... /ISSUED 604 PM CDT MON APR 21 2014/
AVIATION...
VFR EXPECTED TO DOMINATE. AN UPPER LEVEL HIGH PRESSURE RIDGE WILL
BUILD ACROSS THE AREA TONIGHT AND TUESDAY. VERY WEAK HIGH-BASED
CONVECTIVE SHOWERS MAINLY NORTH AND WEST OF THE TAF SITES EXPECTED
TO DISSIPATE BEFORE APPROACHING EITHER LOCATION. MODEST LOW LEVEL
SOUTH TO SOUTHEAST FLOW WILL DEVELOP TUESDAY AS A SURFACE LOW
PRESSURE TROUGH FORMS ALONG THE LEE-SIDE OF THE SOUTHERN AND
CENTRAL ROCKIES. RMCQUEEN
PREV DISCUSSION... /ISSUED 357 PM CDT MON APR 21 2014/
SHORT TERM...
A CUMULUS FIELD IS GRADUALLY DEVELOPING ACROSS THE CAPROCK. THE CU
ARE QUIET SHALLOW AT 230 PM...BUT THERE IS SOME SATELLITE INDICATION
OF MORE BUNCHING AND VERTICAL DEVELOPMENT IN EASTERN NEW MEXICO.
WATER VAPOR IMAGERY IS SHOWING A WEAK SHORTWAVE MOVING TOWARD THE
AREA FROM COLO AND NM...WHILE RAP/SPC ANALYSIS SUGGESTS THAT CIN IS
MINIMAL ON THE CAPROCK WITH ABOUT 500 J/KG OF MLCAPE. IN THIS
REGIME...WE STILL THINK WE/LL SEE SOME ISOLD T-STORM ACTIVITY
DEVELOP LATE THIS AFTERNOON...PERHAPS FOCUSED FROM THE FAR SRN TX
PANHANDLE INTO THE NRN SPLNS. RAINFALL SHOULD BE PRETTY SPOTTY. AND
ANY SHOWERS OR STORMS SHOULD DIE OUT PRETTY QUICKLY THIS EVENING AS
THE BOUNDARY LAYER COOLS. THIS WILL SET THE STAGE FOR A QUIET NIGHT
AND TUESDAY AS A LOW-AMPLITUDE SHORTWAVE RIDGES SLIDES OVER THE
REGION. WINDS WILL BE LIGHT OVERNIGHT AND THEN BEGIN TO PICK UP
TUESDAY AFTERNOON AS LEE TROUGH DEEPENS TO OUR WEST. LATE IN THE
DAY...THE MID-LVL FLOW WILL BEGIN TO BACK AS A DEEP UPPER-LEVEL
TROUGH DIGS INTO THE GREAT BASIN AND DESERT SW. SOME
OROGRAPHICALLY-AIDED CONVECTION MAY DEVELOP IN NM LATE IN THE DAY
BUT LIMITED MOISTURE ACROSS THE CWA SHOULD KEEP SKIES MOSTLY SUNNY
THROUGH 7 PM. TONIGHT/S LOWS SHOULD BE MAINLY IN THE UPPER 40S AND
50S...WHILE HIGHS ON TUESDAY WILL BE MAINLY IN THE 80S.
LONG TERM...
BY WEDNESDAY EVENING...WEST TEXAS LOOKS TO BE SITUATED ALMOST
DIRECTLY UNDERNEATH THE AXIS OF A STOUT UPPER RIDGE...WITH A
POTENT TROUGH RIGHT ON ITS HEELS ACROSS THE GREAT BASIN REGION.
WHILE THE BULK OF THE IMPACTS OF THIS TROUGH WILL LIKELY OCCUR ON
WEDNESDAY...PRESSURE FALLS ALONG MOST OF THE FRONT RANGE WILL
STEADILY INCREASE SOUTHERLY LOW LEVEL FLOW ACROSS THE AREA...THUS
BEGINNING THE SLOW RETURN OF QUALITY MOISTURE INTO THE AREA. WHILE
THE MODIFIED AIRMASS WEDNESDAY NIGHT ACROSS EASTERN NEW MEXICO
WILL STILL FEATURE ONLY MARGINAL DEWPOINTS...UPSLOPE FLOW INTO THE
HIGH TERRAIN IS LIKELY TO INITIATE A FEW SHOWERS AND
THUNDERSTORMS...AND GIVEN A DEVELOPING SOUTHERLY LOW LEVEL
JET...GRADUALLY IMPROVING MOISTURE AND INCREASING STEERING FLOW
OVERNIGHT...A FEW OF THESE SHOWERS AND PERHAPS A WEAK THUNDERSTORM
MAY BE ABLE TO REACH PORTIONS OF THE SOUTH PLAINS DURING THE
EVENING AND OVERNIGHT HOURS. OPTED TO INCREASE POPS INTO THE 10
PERCENT RANGE TO ACCOUNT FOR THIS...ALTHOUGH LEFT OUT EXPLICIT
MENTION IN THE GRIDS FOR THE TIME BEING GIVEN THE EXPECTED SPARSE
COVERAGE.
BY WEDNESDAY AFTERNOON...THE UPPER TROUGH AXIS WILL LIKELY HAVE
REACHED THE SPINE OF THE ROCKIES...SPREADING MODERATE TO STRONG
SOUTHWESTERLY UPPER FLOW ACROSS WEST TEXAS. MEANWHILE AT THE
SURFACE...A DRYLINE WILL GRADUALLY TIGHTEN UP DURING THE AFTERNOON
HOURS ACROSS THE HIGH PLAINS...AND LATEST MODEL GUIDANCE ALL SEEMS
TO SUGGEST THAT IT WILL LIKELY BE LOCATED SOMEWHERE BETWEEN THE I27
CORRIDOR AND THE CAPROCK ESCARPMENT BY MID/LATE AFTERNOON. MODEL
GUIDANCE CONTINUES TO BE VERY BULLISH REGARDING LATE AFTERNOON
THUNDERSTORM INITIATION ALONG THIS DRYLINE...AND IF STORMS DO MANAGE
TO DEVELOP IT APPEARS THAT SHEAR PROFILES WILL BE MORE THAN
SUPPORTIVE OF ROTATING UPDRAFTS. HOWEVER...WHILE THE PERSISTENCE OF
VIGOROUS DRYLINE CONVECTION IN OPERATIONAL GUIDANCE DOES LEND
CONFIDENCE IN INITIATION...CAPPING DOES REMAIN A CONCERN
PARTICULARLY ALONG THE SOUTHERN EXTENT OF THE DRYLINE. ALSO...MODEL
GUIDANCE SEEMS TO SUGGEST THAT DRYLINE CONVERGE MAY BE LESS THAN
IDEAL UNTIL LATE IN THE AFTERNOON...ALTHOUGH THIS MAY BE MITIGATED
SOMEWHAT BY EXPECTED SURFACE TEMPERATURES IN THE MID 80S. SHOULD
STORMS DEVELOP...SUPERCELL STORMS WILL LIKELY BE THE DOMINANT STORM
MODE WITH THE POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS. THE
TORNADO THREAT MAY BE SOMEWHAT LIMITED DESPITE FAVORABLE LOW LEVEL
HODOGRAPHS...DUE TO DEWPOINT SPREADS BETWEEN 25 TO 30 DEGREES AND
RESULTING HIGH LCLS. ALL OF THIS IS TO SAY THAT WE OPTED TO KEEP
POPS MOSTLY UNCHANGED GIVEN THE COMBINATION OF UNCERTAINTIES
REGARDING INITIATION AND ALSO COVERAGE LIMITATIONS THAT USUALLY
RESULT FROM DISCRETE DRYLINE STORMS. ANOTHER THING TO CONSIDER FOR
WEDNESDAY WILL BE THE POTENTIAL FOR FIRE WEATHER ACROSS THE SOUTH
PLAINS ON THE DRY SIDE OF THE DRYLINE. THIS WILL BE MOST LIKELY
NEAR THE TX/NM BORDER WHERE RELATIVE HUMIDITIES WILL BE NEAR THE 15
PERCENT THRESHOLD FOR THE LONGEST PERIOD OF TIME.
OVERNIGHT WEDNESDAY...A COLD FRONT WILL PLUNGE SOUTHWARD...RESULTING
IN A SLIGHTLY COOLER AND VERY PLEASANT DAY THURSDAY. MODELS THEN
HANG THIS FRONT UP ACROSS SOUTH CENTRAL TEXAS...AND ON FRIDAY
SOUTHERLY SURFACE WINDS WILL BEGIN TO GRADUALLY DRAW MOISTURE BACK
NORTHWARD. TEMPERATURES FRIDAY WILL LIKELY BE BACK UP INTO THE
UPPER 80S AND LOW 90S AS WELL...GIVEN OUR POSITION UNDERNEATH A
FLAT UPPER RIDGE.
THE FORECAST FOR THE WEEKEND THEN GETS INTERESTING AGAIN...ALTHOUGH
IT IS STILL RIFE WITH UNCERTAINTIES. OPERATIONAL GUIDANCE CONTINUES
TO EXHIBIT MAJOR PATTERN DIFFERENCES REGARDING THE EVOLUTION OF A
POWERFUL UPPER TROUGH...AND THIS WILL DRAMATICALLY IMPACT THE
POTENTIAL WEATHER FOR OUR AREA SATURDAY AND SUNDAY. THE GFS
SOLUTION CONTINUES TO DIG THIS TROUGH WELL SOUTH INTO THE FOUR
CORNERS REGION...WHERE IT BEGINS TO CLOSE OFF INTO A VERY DEEP
CLOSED LOW. IN ADDITION...IT ALSO DEVELOPS A SHARP DRYLINE AND
KEEPS THIS FEATURE FROM ADVANCING TOO FAR TO THE EAST. UNDER THIS
SETUP...AN EPISODE OF SEVERE WEATHER WOULD BE LIKELY ACROSS AT LEAST
THE ROLLING PLAINS...AND POTENTIALLY A SIGNIFICANT ONE. ON THE
OTHER HAND...THE ECMWF SOLUTION MAINTAINS AN OPEN WAVE FOR MUCH
LONGER...AND FAILS TO DIG THIS TROUGH NEARLY AS DEEP INTO THE FOUR
CORNERS REGION LIKE THE GFS. THIS SCENARIO WOULD ALSO LIKELY RESULT
IN A MUCH MORE EASTERLY POSITION OF THE DRYLINE...AND A DAY OF WINDY
AND DRY CONDITIONS ACROSS THE MAJORITY OF THE CWA. DESPITE MODEL
DIFFERENCES...OPTED TO INCLUDE A LOW MENTION OF THUNDERSTORMS ACROSS
THE ROLLING PLAINS GIVEN THE PERSISTENCE OF THE GFS. BY
SUNDAY...BOTH SOLUTIONS SUGGEST THAT DRY AIR WILL BE FIRMLY IN
PLACE...WITH THE POTENTIAL FOR STRONG WESTERLY WINDS...BLOWING DUST
AND FIRE WEATHER.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 50 80 55 81 45 / 20 0 10 10 10
TULIA 51 80 56 83 47 / 10 0 10 10 10
PLAINVIEW 53 80 58 84 49 / 10 0 0 10 10
LEVELLAND 52 82 58 85 48 / 10 0 10 10 10
LUBBOCK 55 82 59 86 51 / 0 0 0 10 10
DENVER CITY 53 84 60 84 51 / 10 0 10 10 10
BROWNFIELD 54 83 60 86 48 / 0 0 0 10 10
CHILDRESS 55 83 54 86 58 / 0 0 0 30 30
SPUR 56 84 57 86 54 / 0 0 0 20 20
ASPERMONT 59 86 57 91 60 / 0 0 0 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1241 PM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON ACCOMPANIED BY
SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS. HIGH PRESSURE
OVER THE MIDWEST WILL BUILD EASTWARD BY WEDNESDAY BRINGING A
DRY...WINDY AND COOLER DAY. THE NEXT CHANCE FOR PRECIPITATION IS
NOT UNTIL FRIDAY AS ANOTHER FRONT APPROACHES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT TUESDAY...
COLD FRONT REMAINS WELL WEST OF THE MOUNTAINS THIS MORNING WITH A
PRECEDING BAND OF SHOWERS ON THE WESTERN FRINGE OF THE CWA DENOTED
BY A SLIGHTLY ENHANCED BAND OF CLOUDS OFF VIS PICS. THIS PRE-
FRONTAL BAND LOOKS TO BE THE MAIN FOCUS OF ANY ADDITIONAL
CONVECTION THROUGH THE AFTERNOON ESPCLY AS IT CROSSES THE BLUE
RIDGE AFTER MIDDAY. LATEST GUIDANCE SHOWS BRIEF LOW LEVEL BACKING
FROM THE SRN BLUE RIDGE EAST ALONG WITH SOME WEAK INSTABILITY AND
A SLIGHTLY HIGHER AXIS OF 85H THETA-E SNEAKING INTO THE
FOOTHILLS/PIEDMONT. HOWEVER CURRENT INCREASE IN CLOUDS FROM THE
WEST LIKELY TO LIMIT CAPE AS WELL AS THE DEEP WESTERLY FLOW SEEN
OFF MORNING SOUNDINGS. LATEST HRRR AND THE LOCAL RNK-WRF REMAIN
MORE AGGRESSIVE IN DEVELOPING AT LEAST SOME SCTD SHRA/ISOLD TSRA
ALONG THE BLUE RIDGE INTO NW NC AFTER 18Z/2PM AS A FAINT IMPULSE
NOW OVER ERN TN SHEARS EAST. HOWEVER LOW LEVEL MOISTURE ALSO
REMAINS LIMITED PER CURRENT DEWPOINTS SO ONLY HOLDING ONTO LIKELY
POPS FOR NOW TO SEE HOW THINGS UNFOLD WITH BEST QPF OVER THE SW
AND LEAST OVER THE NORTH. OTRW TRIMMING POPS BACK A BIT SOONER FAR
WEST WHILE ADJUSTING TIMING CENTRAL/EAST. LEFT TEMPS CLOSE TO
CURRENT VALUES EXCEPT LOWERING SOME NW PER CURRENT CLDNS AND LIGHT
SHOWERS.
PREVIOUS DISCUSSION AS OF 355 AM EDT TUESDAY...
EARLY MORNING REGIONAL RADAR LOOPS SHOWS SCATTERED SHOWERS ACROSS
PORTIONS OF OHIO AND WEST VIRGINIA BUT THESE ARE SO FAR DRYING UP
AS THEY MOVE EAST INTO DRIER AIR MASS ACROSS OUR REGION. THE COLD
FRONT REMAINS ON TRACK TO CROSS THE MOUNTAINS BY THIS AFTERNOON
WITH SHOWERS AND POSSIBLY A FEW THUNDERSTORMS AHEAD OF AND ALONG
IT. FORECAST SEVERE WEATHER PARAMETERS CONTINUE TO REMAIN MODEST
WITH SREF MEMBERS AND OTHER MODELS SHOWING MEAN MLCAPES GENERALLY
IN 400-600 J/KG RANGE...0-6 KM BULK SHEAR LESS THAN 30 KTS AT TIME
OF MAXIMUM HEATING AND MID-LEVEL LAPSE RATES LESS THAN 7C. SPC DAY
1 OUTLOOK HAS THE REGION WELL WITHIN A SEE TEXT OR MARGINAL CHANCE
OF SEVERE THIS AFTERNOON NOTING THE WEAK FORCING EXPECTED. BEST
CHANCES FOR ISOLATED STRONG THUNDERSTORMS WOULD BE IN FAR EAST IF
EARLY SOLAR HEATING IS ABLE TO BEAT THE INCOMING CLOUD COVER FOR A
FEW HOURS AND GENERATE SOME INSTABILITY. DRY AIR WHICH HAS BEEN
HOLDING TOUGH ALL NIGHT WILL BE FINALLY DISPLACED BY MODEST
NORTHWARD SURGE OF MOISTURE AHEAD OF FRONT WITH FORECAST PWATS
BRIEFLY REACHING 1 INCH IN THE AFTERNOON. HOWEVER QPF ALSO
EXPECTED TO BE LIMITED WITH RELATIVELY DISORGANIZED NATURE OF THE
CONVECTION AND STEADY EASTWARD MOVEMENT OF THE FRONT. GENERALLY
EXPECTING TOTAL AMOUNTS FROM 0.10 TO 0.25 INCHES. WINDS SHIFT INTO
WEST QUICKLY BEHIND FRONT AND SHARPLY COOLER AIR MOVES IN
OVERNIGHT WITH UPPER 30S IN THE FAR NW TO LOW 50S IN THE EAST BY
WED MORNING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM EDT TUESDAY...
SURFACE HIGH PRESSURE WILL TRACK ACROSS THE OHIO VALLEY WEDNESDAY
AND BE OVERHEAD WEDNESDAY NIGHT. THE SURFACE HIGH SLIDES OFF THE
SOUTHEAST COAST THURSDAY WITH A RETURN OF SOUTHERLY FLOW BY THE
AFTERNOON. CLOUDS WILL BEGIN TO STREAM INTO THE REGION THURSDAY
NIGHT AS THE NEXT FRONT APPROACHES THE REGION.
THE PRESSURE GRADIENT REMAINS TIGHT WITH PRESSURE RISES CONTINUING
ALONG WITH A 40-50KT CROSS-BARRIER JET OVER THE FORECAST AREA
WEDNESDAY MORNING. BREEZY AND GUSTY CONDITIONS ARE EXPECTED INTO
EARLY WEDNESDAY AFTERNOON. AS THE HIGH MOVES CLOSER TO THE
REGION...THE WINDS WILL DIMINISH BY THE EVENING...BECOMING CALM
WEDNESDAY NIGHT.
FOLLOWING THE FRONTAL PASSAGE TUESDAY...WEDNESDAY TEMPERATURES WILL
BE AROUND 5F COOLER THAN NORMAL. WITH THE HIGH OVERHEAD WEDNESDAY
NIGHT...RADIATIONAL COOLING WILL DROP MOUNTAIN VALLEY TEMPERATURES
INTO THE 30S WITH PATCHY FROST POSSIBLE. TEMPERATURES IN THE EAST
MAY DROP TO 40F WEDNESDAY NIGHT WITH NO FROST EXPECTED. TEMPERATURES
REBOUND QUICKLY TO NORMAL LEVELS THURSDAY WITH RANGES FROM THE UPPER
60S TO LOWER 70S. THURSDAY NIGHT WILL HAVE MILD TEMPERATURES IN THE
50S AHEAD OF THE NEXT FRONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...
DESPITE AN INCREASE IN CLOUDS AND A CHANCE FOR SHOWERS AND STORMS
ASSOCIATED WITH A COLD FRONT FRIDAY...STRONG WARM AIR ADVECTION
WITH A DEEP SOUTHWEST/WEST FLOW...SHOULD CONTINUE THE TREND FOR
MODERATING TEMPS.
THE PATTERN FRIDAY APPEARS VERY SIMILAR TO TUESDAY`S...WITH A FAST
MOVING COLD FRONT MOVING INTO THE WEST EARLY ON FRIDAY AND EXITING
DURING THE AFTERNOON. ONCE AGAIN...LOW LEVEL MOISTURE AND
INSTABILITY WILL BE RACING NORTH TO INTERCEPT THE FRONT IN THE FAR
EASTERN PORTION OF THE FORECAST AREA. THIS WILL BE WHERE THE BEST
CHANCE FOR THUNDERSTORMS WILL TAKE PLACE.
WHILE THE FRONT PASSES THROUGH FRIDAY AFTERNOON...THE STRONG COLD
AIR ADVECTION IS DELAYED UNTIL LATER SATURDAY...SO ANOTHER WARM DAY
IS ANTICIPATED EAST OF THE BLUE RIDGE.
AFTER SATURDAY THERE ARE CONSIDERABLE DIFFERENCES IN THE LONG RANGE
MODELS WITH THE GFS...CANADIAN AND GFS ENSEMBLES ALL KEEPING A SFC
FRONT TO OUR SOUTH WITH A DRY NORTHWEST FLOW. MEANWHILE...THE 00Z/21
ECMWF KEEPS OUR AREA IN THE WARM SECTOR WITH A MOIST SOUTHERLY FLOW.
THE GFS HAS SHOWN MORE RUN TO RUN CONSISTENCY AND THE LATEST GLOBAL
WIND OSCILLATION (GWO) PLOT FAVORS AN EASTERN U.S. TROF.
THEREFORE...NUDGED TEMPS DOWN A FEW DEGREES AND KEPT AREA FREE OF
PRECIPITATION THROUGH THE WEEKEND. A QUICK LOOK AT THE 12Z ECMWF
SHOWS A TREND TOWARD THIS COOLER SOLUTION.
AS A SFC WARM FRONT BEGINS TO LIFT NORTH AND LOW LEVEL MOISTURE
RETURNS...SCATTERED SHOWERS POSSIBLE IN THE MOUNTAINS. CONFIDENCE ON
THE LOCATION OF THE WARM FRONT AND CHANCES FOR PRECIP ARE LOW.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
AS OF 1220 PM EDT TUESDAY...
BROKEN PRE-FRONTAL BAND OF -SHRA CONTINUES TO SHIFT SE ACROSS THE
WEST EARLY THIS AFTERNOON WITH MOST RAINFALL REMAINING SOUTH/WEST
OF THE TAF SITES. THIS SHOULD KEEP OVERALL VFR CONDITIONS GOING
FOR A WHILE LONGER AS WESTERLY WINDS TEND TO ERODE THE EASTWARD
PUSH OF THE PRECIP. HOWEVER EXPECT A GRADUAL INCREASE IN BOTH
COVERAGE/INTENSITY OVER THE SW SECTIONS THIS AFTERNOON WITH AN
EVENTUAL JUMP OUT EAST OF THE BLUE RIDGE BY 19Z/3PM. OTRW BEST
CHANCE OF MVFR CIGS/VSBYS WILL BE AT BLF/LWB WITH LOWERING CIGS
UNDER UPSLOPE FLOW AND LIGHTER SHOWERS. BAND OF ISOLATED TO
SCATTERED SHRA/TSRA POSSIBLE ALONG THE LYH-DAN CORRIDOR THIS
AFTERNOON WHERE A PERIOD OF MVFR CONDITIONS ALSO POSSIBLE BUT LOW
CONFIDENCE AT THIS POINT. COULD SEE BRIEF STRONG WINDS IN ANY
THUNDERSTORMS THAT DO DEVELOP.
THE FRONT WILL EXIT THE REGION THIS EVENING...RESULTING IN A
RETURN TO VFR WEATHER AND GUSTY NW WINDS OVERNIGHT INTO
WEDNESDAY. ONLY EXCEPTTION IS THE POTENTIAL OF SOME MVFR CIGS AND
SPOTTY -SHRA LINGERING OVER THE FAR WESTERN UPSLOPE SITES IN SE
WEST VA. PERIODS OF STRONGER WINDS WILL OCCUR BEHIND THE FRONT
OVERNIGHT WITH GUSTS TO 30 KTS POSSIBLE...AND AGAIN WITH STRONG
MIXING WEDNESDAY.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE WILL THEN BUILD INTO AND OVER THE REGION ON
THURSDAY...WITH WIDESPREAD VFR LIKELY. ANOTHER FAST MOVING COLD
FRONT WILL ARRIVE ON FRIDAY...WITH A BRIEF PERIOD OF MVFR
RESTRICTIONS POSSIBLE AS SHOWERS/ISOLATED STORMS MOVE EAST WITH
THE FRONT THROUGH THE AREA. STRONG HIGH PRESSURE BUILDS IN FRIDAY
NIGHT INTO SATURDAY WITH VFR EXPECTED UNDER GUSTY NORTHWEST WINDS.
&&
.FIRE WEATHER...
AS OF 945 AM EDT TUESDAY...
COLD FRONT WILL CROSS THE REGION THIS AFTERNOON WITH MODEST
RAINFALL RANGING FROM LESS THAN 0.10 INCHES IN THE PIEDMONT UP TO
AROUND 0.25 INCHES IN THE SOUTHWEST MOUNTAINS AND PERHAPS NORTH
CAROLINA FOOTHILLS. STRONG NW WINDS WILL FOLLOW THE FRONT ON
WEDNESDAY WITH GUSTS TO 25 TO 35 MPH POSSIBLE ALONG WITH ANOTHER
QUICK DROP IN HUMIDITY WEDNESDAY AFTERNOON. THIS MAY LEAD TO
ENHANCED FIRE DANGER ESPECIALLY IF LESS WETTING RAINFALL IS
REALIZED WITH THE FRONTAL PASSAGE THIS AFTERNOON/EVENING. A FIRE
WEATHER WATCH MAY BE NEEDED FOR PARTS OF THE AREA ON WEDNESDAY.
THE NEXT BEST OPPORTUNITY FOR PRESCRIBED BURNS WHERE GOOD DRYING
CONDITIONS WILL EXIST...AND WHERE TRANSPORT WINDS WILL BE MORE
FAVORABLE DUE TO BETTER TRANSPORT AND CONSISTENCY OF DIRECTION
WILL OCCUR ON THURSDAY AT THIS POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC
NEAR TERM...JH/PC
SHORT TERM...RCS
LONG TERM...PH
AVIATION...JH/KK/PC
FIRE WEATHER...JH/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1017 AM EDT TUE APR 22 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON ACCOMPANIED BY
SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS. HIGH PRESSURE
OVER THE MIDWEST WILL BUILD EASTWARD BY WEDNESDAY BRINGING A
DRY...WINDY AND COOLER DAY. THE NEXT CHANCE FOR PRECIPITATION IS
NOT UNTIL FRIDAY AS ANOTHER FRONT APPROACHES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT TUESDAY...
COLD FRONT REMAINS WELL WEST OF THE MOUNTAINS THIS MORNING WITH A
PRECEDING BAND OF SHOWERS ON THE WESTERN FRINGE OF THE CWA DENOTED
BY A SLIGHTLY ENHANCED BAND OF CLOUDS OFF VIS PICS. THIS PRE-
FRONTAL BAND LOOKS TO BE THE MAIN FOCUS OF ANY ADDITIONAL
CONVECTION THROUGH THE AFTERNOON ESPCLY AS IT CROSSES THE BLUE
RIDGE AFTER MIDDAY. LATEST GUIDANCE SHOWS BRIEF LOW LEVEL BACKING
FROM THE SRN BLUE RIDGE EAST ALONG WITH SOME WEAK INSTABILITY AND
A SLIGHTLY HIGHER AXIS OF 85H THETA-E SNEAKING INTO THE
FOOTHILLS/PIEDMONT. HOWEVER CURRENT INCREASE IN CLOUDS FROM THE
WEST LIKELY TO LIMIT CAPE AS WELL AS THE DEEP WESTERLY FLOW SEEN
OFF MORNING SOUNDINGS. LATEST HRRR AND THE LOCAL RNK-WRF REMAIN
MORE AGGRESSIVE IN DEVELOPING AT LEAST SOME SCTD SHRA/ISOLD TSRA
ALONG THE BLUE RIDGE INTO NW NC AFTER 18Z/2PM AS A FAINT IMPULSE
NOW OVER ERN TN SHEARS EAST. THUS HOLDING ONTO LIKELY POPS FOR
NOW TO SEE HOW THINGS UNFOLD WITH BEST QPF OVER THE SW AND LEAST
OVER THE NORTH. OTRW TRIMMING POPS BACK A BIT SOONER FAR WEST
WHILE ADJUSTING TIMING CENTRAL/EAST. LEFT TEMPS CLOSE TO CURRENT
VALUES EXCEPT LOWERING SOME NW PER CURRENT CLDNS AND LIGHT
SHOWERS.
PREVIOUS DISCUSSION AS OF 355 AM EDT TUESDAY...
EARLY MORNING REGIONAL RADAR LOOPS SHOWS SCATTERED SHOWERS ACROSS
PORTIONS OF OHIO AND WEST VIRGINIA BUT THESE ARE SO FAR DRYING UP
AS THEY MOVE EAST INTO DRIER AIR MASS ACROSS OUR REGION. THE COLD
FRONT REMAINS ON TRACK TO CROSS THE MOUNTAINS BY THIS AFTERNOON
WITH SHOWERS AND POSSIBLY A FEW THUNDERSTORMS AHEAD OF AND ALONG
IT. FORECAST SEVERE WEATHER PARAMETERS CONTINUE TO REMAIN MODEST
WITH SREF MEMBERS AND OTHER MODELS SHOWING MEAN MLCAPES GENERALLY
IN 400-600 J/KG RANGE...0-6 KM BULK SHEAR LESS THAN 30 KTS AT TIME
OF MAXIMUM HEATING AND MID-LEVEL LAPSE RATES LESS THAN 7C. SPC DAY
1 OUTLOOK HAS THE REGION WELL WITHIN A SEE TEXT OR MARGINAL CHANCE
OF SEVERE THIS AFTERNOON NOTING THE WEAK FORCING EXPECTED. BEST
CHANCES FOR ISOLATED STRONG THUNDERSTORMS WOULD BE IN FAR EAST IF
EARLY SOLAR HEATING IS ABLE TO BEAT THE INCOMING CLOUD COVER FOR A
FEW HOURS AND GENERATE SOME INSTABILITY. DRY AIR WHICH HAS BEEN
HOLDING TOUGH ALL NIGHT WILL BE FINALLY DISPLACED BY MODEST
NORTHWARD SURGE OF MOISTURE AHEAD OF FRONT WITH FORECAST PWATS
BRIEFLY REACHING 1 INCH IN THE AFTERNOON. HOWEVER QPF ALSO
EXPECTED TO BE LIMITED WITH RELATIVELY DISORGANIZED NATURE OF THE
CONVECTION AND STEADY EASTWARD MOVEMENT OF THE FRONT. GENERALLY
EXPECTING TOTAL AMOUNTS FROM 0.10 TO 0.25 INCHES. WINDS SHIFT INTO
WEST QUICKLY BEHIND FRONT AND SHARPLY COOLER AIR MOVES IN
OVERNIGHT WITH UPPER 30S IN THE FAR NW TO LOW 50S IN THE EAST BY
WED MORNING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM EDT TUESDAY...
SURFACE HIGH PRESSURE WILL TRACK ACROSS THE OHIO VALLEY WEDNESDAY
AND BE OVERHEAD WEDNESDAY NIGHT. THE SURFACE HIGH SLIDES OFF THE
SOUTHEAST COAST THURSDAY WITH A RETURN OF SOUTHERLY FLOW BY THE
AFTERNOON. CLOUDS WILL BEGIN TO STREAM INTO THE REGION THURSDAY
NIGHT AS THE NEXT FRONT APPROACHES THE REGION.
THE PRESSURE GRADIENT REMAINS TIGHT WITH PRESSURE RISES CONTINUING
ALONG WITH A 40-50KT CROSS-BARRIER JET OVER THE FORECAST AREA
WEDNESDAY MORNING. BREEZY AND GUSTY CONDITIONS ARE EXPECTED INTO
EARLY WEDNESDAY AFTERNOON. AS THE HIGH MOVES CLOSER TO THE
REGION...THE WINDS WILL DIMINISH BY THE EVENING...BECOMING CALM
WEDNESDAY NIGHT.
FOLLOWING THE FRONTAL PASSAGE TUESDAY...WEDNESDAY TEMPERATURES WILL
BE AROUND 5F COOLER THAN NORMAL. WITH THE HIGH OVERHEAD WEDNESDAY
NIGHT...RADIATIONAL COOLING WILL DROP MOUNTAIN VALLEY TEMPERATURES
INTO THE 30S WITH PATCHY FROST POSSIBLE. TEMPERATURES IN THE EAST
MAY DROP TO 40F WEDNESDAY NIGHT WITH NO FROST EXPECTED. TEMPERATURES
REBOUND QUICKLY TO NORMAL LEVELS THURSDAY WITH RANGES FROM THE UPPER
60S TO LOWER 70S. THURSDAY NIGHT WILL HAVE MILD TEMPERATURES IN THE
50S AHEAD OF THE NEXT FRONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...
DESPITE AN INCREASE IN CLOUDS AND A CHANCE FOR SHOWERS AND STORMS
ASSOCIATED WITH A COLD FRONT FRIDAY...STRONG WARM AIR ADVECTION
WITH A DEEP SOUTHWEST/WEST FLOW...SHOULD CONTINUE THE TREND FOR
MODERATING TEMPS.
THE PATTERN FRIDAY APPEARS VERY SIMILAR TO TUESDAY`S...WITH A FAST
MOVING COLD FRONT MOVING INTO THE WEST EARLY ON FRIDAY AND EXITING
DURING THE AFTERNOON. ONCE AGAIN...LOW LEVEL MOISTURE AND
INSTABILITY WILL BE RACING NORTH TO INTERCEPT THE FRONT IN THE FAR
EASTERN PORTION OF THE FORECAST AREA. THIS WILL BE WHERE THE BEST
CHANCE FOR THUNDERSTORMS WILL TAKE PLACE.
WHILE THE FRONT PASSES THROUGH FRIDAY AFTERNOON...THE STRONG COLD
AIR ADVECTION IS DELAYED UNTIL LATER SATURDAY...SO ANOTHER WARM DAY
IS ANTICIPATED EAST OF THE BLUE RIDGE.
AFTER SATURDAY THERE ARE CONSIDERABLE DIFFERENCES IN THE LONG RANGE
MODELS WITH THE GFS...CANADIAN AND GFS ENSEMBLES ALL KEEPING A SFC
FRONT TO OUR SOUTH WITH A DRY NORTHWEST FLOW. MEANWHILE...THE 00Z/21
ECMWF KEEPS OUR AREA IN THE WARM SECTOR WITH A MOIST SOUTHERLY FLOW.
THE GFS HAS SHOWN MORE RUN TO RUN CONSISTENCY AND THE LATEST GLOBAL
WIND OSCILLATION (GWO) PLOT FAVORS AN EASTERN U.S. TROF.
THEREFORE...NUDGED TEMPS DOWN A FEW DEGREES AND KEPT AREA FREE OF
PRECIPITATION THROUGH THE WEEKEND. A QUICK LOOK AT THE 12Z ECMWF
SHOWS A TREND TOWARD THIS COOLER SOLUTION.
AS A SFC WARM FRONT BEGINS TO LIFT NORTH AND LOW LEVEL MOISTURE
RETURNS...SCATTERED SHOWERS POSSIBLE IN THE MOUNTAINS. CONFIDENCE ON
THE LOCATION OF THE WARM FRONT AND CHANCES FOR PRECIP ARE LOW.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 0700 AM EDT MONDAY...
AN AREA OF SCATTERED RAIN SHOWERS ALONG A COLD FRONT ACRS THE
OHIO VALLEY THIS MORNING WILL CONTINUE TO APPROACH THE TERMINALS
LATER THIS MORNING AND MAY PRODUCE BRIEF MVFR FLIGHT RESTRICTIONS
WITHIN PASSING SHOWERS OR ISOLATED THUNDERSTORMS. BEST CHANCE OF
MVFR CIGS/VSBYS WILL BE AT BLF/LWB WITH LIGHTER SOWERS EXPECTED
OUT TO THE BLUE RIDGE LATER IN THE MORNING. ISOLATED TO SCATTERED
SHRA/TSRA POSSIBLE ALONG THE LYH-DAN CORRIDOR THIS AFTERNOON.
COULD SEE BRIEF STRONG WINDS IN ANY THUNDERSTORMS THAT DO DEVELOP.
MEDIUM CONFIDENCE IN CEILING...VISIBILITIES AND WINDS DURING THE
TAF PERIOD AS CONDITIONS LIKELY TO BE CHANGEABLE.
THE FRONT WILL EXIT THE REGION BY TUESDAY NIGHT...RESULTING IN A
RETURN TO VFR WEATHER AND GUSTY NW WINDS TUESDAY NIGHT INTO
WEDNESDAY...EXCEPT FOR THE POTENTIAL OF SOME MVFR CIGS LINGERING
OVER THE FAR WESTERN UPSLOPE SITES IN SE WEST VA.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE WILL THEN BUILD INTO AND OVER THE REGION ON
THURSDAY...WITH WIDESPREAD VFR LIKELY. ANOTHER FAST MOVING COLD
FRONT WILL ARRIVE ON FRIDAY...WITH A BRIEF PERIOD OF MVFR
RESTRICTIONS POSSIBLE AS SHOWERS/ISOLATED STORMS MOVE EAST WITH
THE FRONT THROUGH THE AREA.
&&
.FIRE WEATHER...
AS OF 945 AM EDT TUESDAY...
COLD FRONT WILL CROSS THE REGION TODAY WITH MODEST RAINFALL
RANGING FROM LESS THAN 0.10 INCHES IN THE PIEDMONT UP TO AROUND
0.25 INCHES IN THE SOUTHWEST MOUNTAINS AND PERHAPS NORTH CAROLINA
FOOTHILLS. STRONG NW WINDS WILL FOLLOW THE FRONT ON WEDNESDAY
WITH GUSTS TO 25 TO 35 MPH POSSIBLE ALONG WITH ANOTHER QUICK DROP
IN HUMIDITY WEDNESDAY AFTERNOON. THIS MAY LEAD TO ENHANCED FIRE
DANGER ESPECIALLY IF LESS WETTING RAINFALL IS REALIZED WITH THE
FRONTAL PASSAGE THIS AFTERNOON/EVENING. A FIRE WEATHER WATCH MAY
BE NEEDED FOR PARTS OF THE AREA ON WEDNESDAY.
THE NEXT BEST OPPORTUNITY FOR PRESCRIBED BURNS WHERE GOOD DRYING
CONDITIONS WILL EXIST...AND WHERE TRANSPORT WINDS WILL BE MORE
FAVORABLE DUE TO BETTER TRANSPORT AND CONSISTENCY OF DIRECTION
WILL OCCUR ON THURSDAY AT THIS POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC
NEAR TERM...JH/PC
SHORT TERM...RCS
LONG TERM...PH
AVIATION...KK/PC
FIRE WEATHER...JH/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
143 AM EDT TUE APR 22 2014
.SYNOPSIS...
SURFACE HIGH PRESSURE EXTENDING ACROSS THE REGION FROM THE MID
ATLANTIC COAST WILL WEAKEN AND PASS OFFSHORE OVERNIGHT. A COLD
FRONT IN THE MIDWEST WILL SWEEP SOUTHEAST THROUGH THE AREA ON
TUESDAY...PRECEDED AND ACCOMPANIED BY SCATTERED SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE IS EXPECTED TO RETURN TO THE AREA ON
WEDNESDAY...BRINGING BLUSTERY AND COOLER WEATHER.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 915 PM EDT MONDAY...
ADJUSTED TEMPERATURES...DEW POINTS AND POPS FOR TONIGHT INTO
TUESDAY MORNING. LOCAL RNK WRFARW BRINGS ISOLATED TO SCATTERED
SHOWERS IN THE FAR WEST AROUND 08Z TUESDAY. THE HRRR IS A LITTLE
SLOWER WITH THE CONVECTION BRING IN SCATTERED SHOWERS IN AROUND
10Z. THE NAM AND ECMWF HAVE SIMILAR TIMING OF PRECIPITATION...WITH
THE GFS A BIT QUICKER WITH CONVECTION. REGIONAL WSR-88D IMAGES
DEPICTED A FEW ECHOES MOSTLY ALOFT TO OUR WEST FIGHTING VERY DRY
AIR AS SEEN IN THE EVENING 00Z/8PM RNK SOUNDING. FIRST FEW ROUND
OF SHOWERS WILL TAKE SOME TIME TO SATURATE THE COLUMN. BY DAYBREAK
EXPECTED SCATTERED SHOWERS ACROSS THE MOUNTAINS IN ADVANCE OF
APPROACHING FRONTAL ZONE. LOW TEMPERATURES WILL RANGE FROM THE MID
40S IN THE COLDER VALLEYS TO MID 50S ALONG THE WESTERN RIDGES. THE
COLD FRONT WILL TRAVEL SOUTHEAST THROUGH THE AREA ON
TUESDAY...PRECEDED AND ACCOMPANIED BY SCATTERED SHOWERS AND
THUNDERSTORMS. THERE STILL ENOUGH INSTABILITY TO SUPPORT THE
MENTION OF THUNDERSTORMS LATE MORNING INTO THE AFTERNOON. WEAK
WESTERLY FLOW/SHEAR AND LIMITED LAPSES RATES EXPECTED WITH STORMS.
HIGH TEMPERATURES TUESDAY WILL VARY FROM THE LOWER 60S IN THE
NORTHWEST MOUNTAINS TO AROUND 80 DEGREES IN THE PIEDMONT.
AS OF 605 PM EDT MONDAY...
ADJUSTED TEMPERATURES AND DEW POINTS ACCORDING TO LATEST OBS AND
MODEL TRENDS. THIS EVENING RIDGING ACROSS THE REGION WILL WEAKEN
TONIGHT INTO TUESDAY MORNING...AS 1019 SURFACE HIGH PRESSURE
CENTER LIFTS NORTHEAST. A COLD FRONT TO OUR WEST WILL APPROACH
LATE TONIGHT...WITH A GRADUAL RETURN OF LOW LEVEL MOISTURE. LOW
TEMPERATURES OVERNIGHT ARE A CHALLENGE WITH THE POTENTIAL FOR BIG
DROPS IN THE EAST WITH MOSTLY CLEAR SKIES AND RISING TEMPERATURES
OR STEADY IN THE WEST WITH INCREASING CLOUD COVER. WILL MONITOR
THIS EVENING FOR ADDITIONAL CHANGES LATER TONIGHT. HAVE A GOOD
EVENING.
AS OF 200 PM EDT MONDAY...
RIDGING ACROSS THE REGION EARLY THIS EVENING WILL QUICKLY WEAKEN
OVERNIGHT AS THE SURFACE HIGH PULLS OUT TO THE NE AND UPSTREAM 5H
HEIGHT FALLS DAMPEN OUT THE MID LEVEL SHORTWAVE RIDGE. THIS SHOULD
ALLOW FOR A GRADUAL RETURN OF LOW LEVEL MOISTURE OVERNIGHT ALONG
WITH AN INCREASE IN HIGH/MID CLOUDS AHEAD OF THE FRONT ESPCLY
AFTER MIDNIGHT. HOWEVER THE MID LEVELS REMAIN QUITE DRY SO
THINKING THAT MOST -SHRA SHOULD STAY JUST WEST OF THE CWA THROUGH
DAYBREAK AT THIS POINT. OTRW MAINLY CLEAR EARLY THEN BECOMING
MOSTLY CLOUDY WEST AND PC EAST BY MORNING. LOWS A BIT TRICKY WITH
POTENTIAL TO SEE QUICK TEMP FALLS WHILE CLEAR THIS EVENING...THEN
A STEADYING OUT SCENARIO OVERNIGHT ESPCLY MOUNTAINS AS CLOUDS
ARRIVE. THEREFORE LEANED CLOSER TO THE WARMER MET MOS WEST ESPCLY
RIDGES...AND WITH THE COLDER MAV EAST WHERE SHOULD STAY CLEAR
LONGER.
STILL QUESTIONS IN REGARDS TO CONVECTIVE POTENTIAL WITH THE PASSING
COLD FRONT TUESDAY AFTERNOON AND THE DEGREE OF QPF THAT MIGHT OCCUR
OUTSIDE OF THE WESTERN SLOPES. LATEST GUIDANCE HAS TRENDED A BIT
SLOWER IN PUSHING INITIAL PRE-FRONTAL BAND OF SHRA OVER THE WESTERN
MOUNTAINS TUESDAY MORNING WHICH WOULD ALLOW MORE TIME FOR MOISTURE
ADVECTION AND INSTABILITY TO DEVELOP OUT EAST CLOSER TO THE LEE
TROUGH. HOWEVER APPEARS LOTS OF CLOUDS TO ARRIVE EARLY OVER THE WEST
WHICH COULD LIMIT HEATING AND CAUSE A JUMP IN FADING SHRA OVER THE
WEST TO A DEEPER BAND OF SHRA/TSRA TO THE EAST OF THE CWA GIVEN
DEEPENING DOWNSLOPE EAST OF THE BLUE RIDGE. FOR NOW WILL GO A BIT
SLOWER...SIMILAR TO THE SPC WRF SOLUTION IN BRINGING SHRA INTO THE
WEST BY MID/LATE MORNING UNDER A FAINT WAVE ALOFT...THEN WEAKENING
BEFORE PERHAPS REDEVELOPING ACROSS THE FAR EASTERN CWA BY MID
AFTERNOON UNDER THE LEE TROUGH AS SEEING JUST ENOUGH LOW LEVEL
BACKING FOR THIS TO OCCUR. OTRW SEVERE THREAT APPEARS LOW GIVEN
RATHER WEAK WESTERLY FLOW/SHEAR AND LAPSES...WITH ONLY THE DRIER
LOW LEVELS POSSIBLY ENHANCING LOCALIZED WINDS IF ANY CELLS CAN
GET ORGANIZED/STRONG ENOUGH AND A SPLIT OUT EAST DOESN`T OCCUR.
THUS CONTINUED THE TREND OF GOING WITH A PERIOD OF LIKELY POPS
FROM NW TO SE DURING THE DAY FOR NOW WITH LESS SE GIVEN WEST
WINDS AND HIGHER PROBS NW WHERE UP TO A HALF INCH OF QPF COULD
OCCUR. ELSW APPEARS LOW QPF WITH ONLY A TENTH OF AN INCH OR LESS
EAST AND PERHAPS UP TO A QUARTER INCH ELSW WEST OF THE BLUE RIDGE.
HIGH TEMPS LOOK TO PUSH 80 AHEAD OF THE BOUNDARY PIEDMONT...WITH
70S BLUE RIDGE BUT ONLY MID/UPPER 60S WEST WHERE CLOUDS/-SHRA
COULD KEEP VALUES EVEN COOLER PENDING EARLIER TIMING.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
AS OF 300 PM EDT MONDAY...
BY 00Z (7 PM EDT) TUESDAY THE COLD FRONT WILL BE WELL EAST OF OUR
FORECAST AIR WITH STRONG NORTHWEST WINDS GENERATING A FEW UPSLOPE
RAIN SHOWERS. NORTHWEST WINDS WILL BE QUITE GUSTY WITH STRONG
PRESSURE RISES MOVING THROUGH BETWEEN 03Z-09Z. BUFKIT TIME CROSS
SECTION SHOWS 50 KTS ABOVE THE INVERSION AOA 5KT FEET. BUMPED UP
WINDS...ESPECIALLY IN THE MOUNTAINS TUESDAY NIGHT...BUT FORECAST
VALUES STILL BELOW WIND ADVISORY CRITERIA.
COLD AIR ADVECTION WEDNESDAY MORNING SHOULD ALLOW TEMPS TO DROP TO
COOLER GFS GUIDANCE IN THE MOUNTAINS.
WINDS GRADUALLY RELAX WEDNESDAY AS SFC HIGH PRESSURE BUILDS FROM
THE GREAT LAKES. GOOD DRYING ALSO EXPECTED WEDNESDAY...WITH RH
VALUES FALLING INTO THE 20S FOR MOST AREAS. LEANED TOWARD THE
WARMER GFS GUIDANCE EAST OF THE BLUE RIDGE...WITH DOWNSLOPING
WINDS...WITH A FEW DEGREES SHAVED OFF GUIDANCE IN THE MOUNTAINS
WHERE COLD AIR ADVECTION LINGERS.
GOOD RADIATIONAL COOLING DEVELOPING LATE WEDNESDAY NIGHT AS THE SFC
RIDGE AXIS FORECAST TO BE OVERHEAD BY EARLY THURSDAY MORNING. WITH
PLENTY OF DRY AIR IN PLACE...SOME AREAS OF FROST POSSIBLE IN THE
MOUNTAINS.
RIDGING AT THE SFC AND ALOFT...WITH A RETURN TO A SOUTH/SOUTHWEST
FLOW WILL RESULT IN WARMER TEMPERATURES...WITH MOST AREAS REACHING
OR EXCEEDING 70.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...
DESPITE AN INCREASE IN CLOUDS AND A CHANCE FOR SHOWERS AND STORMS
ASSOCIATED WITH A COLD FRONT FRIDAY...STRONG WARM AIR ADVECTION
WITH A DEEP SOUTHWEST/WEST FLOW...SHOULD CONTINUE THE TREND FOR
MODERATING TEMPS.
THE PATTERN FRIDAY APPEARS VERY SIMILAR TO TUESDAY`S...WITH A FAST
MOVING COLD FRONT MOVING INTO THE WEST EARLY ON FRIDAY AND EXITING
DURING THE AFTERNOON. ONCE AGAIN...LOW LEVEL MOISTURE AND
INSTABILITY WILL BE RACING NORTH TO INTERCEPT THE FRONT IN THE FAR
EASTERN PORTION OF THE FORECAST AREA. THIS WILL BE WHERE THE BEST
CHANCE FOR THUNDERSTORMS WILL TAKE PLACE.
WHILE THE FRONT PASSES THROUGH FRIDAY AFTERNOON...THE STRONG COLD
AIR ADVECTION IS DELAYED UNTIL LATER SATURDAY...SO ANOTHER WARM DAY
IS ANTICIPATED EAST OF THE BLUE RIDGE.
AFTER SATURDAY THERE ARE CONSIDERABLE DIFFERENCES IN THE LONG RANGE
MODELS WITH THE GFS...CANADIAN AND GFS ENSEMBLES ALL KEEPING A SFC
FRONT TO OUR SOUTH WITH A DRY NORTHWEST FLOW. MEANWHILE...THE 00Z/21
ECMWF KEEPS OUR AREA IN THE WARM SECTOR WITH A MOIST SOUTHERLY FLOW.
THE GFS HAS SHOWN MORE RUN TO RUN CONSISTENCY AND THE LATEST GLOBAL
WIND OSCILLATION (GWO) PLOT FAVORS AN EASTERN U.S. TROF.
THEREFORE...NUDGED TEMPS DOWN A FEW DEGREES AND KEPT AREA FREE OF
PRECIPITATION THROUGH THE WEEKEND. A QUICK LOOK AT THE 12Z ECMWF
SHOWS A TREND TOWARD THIS COOLER SOLUTION.
AS A SFC WARM FRONT BEGINS TO LIFT NORTH AND LOW LEVEL MOISTURE
RETURNS...SCATTERED SHOWERS POSSIBLE IN THE MOUNTAINS. CONFIDENCE ON
THE LOCATION OF THE WARM FRONT AND CHANCES FOR PRECIP ARE LOW.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM EDT MONDAY...
SCATTERED SHOWERS ACRS THE OHIO VALLEY EARLY THIS MORNING WILL
SHIFT EAST WITH APPROACHING COLD FRONT LATER THIS MORNING.
LOCALIZED MVFR FLIGHT RESTRICTIONS LIKELY WITH PASSING SHOWERS
WITH BEST CHANCE OF MVFR CIGS AND/OR VSBYS AT BLF/LWB WITH ONLY
LIGHTER SHOWERS OUT TO THE BLUE RIDGE LATER IN THE MORNING. ISOLATED
TO SCATTERED SHRA/TSRA POSSIBLE ALONG THE LYH-DAN CORRIDOR THIS
AFTERNOON.
MEDIUM CONFIDENCE IN CEILING...VISIBILITIES AND WINDS DURING THE
TAF PERIOD AS CONDITIONS LIKELY TO BE CHANGEABLE.
THE FRONT WILL EXIT THE REGION BY TUESDAY NIGHT...RESULTING IN A
RETURN TO VFR WEATHER AND GUSTY NW WINDS TUESDAY NIGHT INTO
WEDNESDAY...EXCEPT FOR THE POTENTIAL OF SOME MVFR CIGS LINGERING
OVER THE FAR WESTERN UPSLOPE SITES IN SE WEST VA.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE WILL THEN BUILD INTO AND OVER THE REGION ON
THURSDAY...WITH WIDESPREAD VFR LIKELY. ANOTHER FAST MOVING COLD
FRONT WILL ARRIVE ON FRIDAY...WITH A BRIEF PERIOD OF MVFR
RESTRICTIONS POSSIBLE AS SHOWERS/ISOLATED STORMS MOVE EAST WITH
THE FRONT THROUGH THE AREA.
&&
.FIRE WEATHER...
AS OF 927 PM EDT MONDAY...
MOISTURE WILL SLOWLY RECOVER OVERNIGHT AND THEN MOISTEN ABOVE
60-70 PERCENT BY EARLY TUESDAY AHEAD OF THE APPROACHING COLD
FRONT. THE FRONT WILL CROSS THE REGION ON TUESDAY WITH QPF RANGING
FROM ONE QUARTER TO ONE HALF INCH IN PARTS OF WEST VA...TO A TENTH
OR QUARTER INCH BLUE RIDGE...TO LIKELY LESS THAN A TENTH OF AN
INCH PIEDMONT. STRONG NW WINDS FOLLOWING THE FRONT MAY BE OF ADDED
CONCERN ON WEDNESDAY WITH GUSTS TO 25 TO 35 MPH POSSIBLE ALONG
WITH ANOTHER QUICK DROP IN HUMIDITY WEDNESDAY AFTERNOON. THIS MAY
LEAD TO ENHANCED FIRE DANGER ESPECIALLY IF LESS WETTING RAINFALL
IS REALIZED WITH THE FRONTAL PASSAGE ON TUESDAY.
THE NEXT BEST OPPORTUNITY FOR PRESCRIBED BURNS WHERE GOOD DRYING
CONDITIONS WILL EXIST...AND WHERE TRANSPORT WINDS WILL BE MORE
FAVORABLE DUE TO BETTER TRANSPORT AND CONSISTENCY OF DIRECTION
WILL OCCUR ON THURSDAY AT THIS POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WERT
NEAR TERM...JH/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/PC
FIRE WEATHER...JH/KK/WERT
AREA FORECAST DISCUSSION
NWS PORTLAND OR
302 AM PDT TUE APR 22 2014
.SYNOPSIS...A SERIES OF UPPER TROUGHS WILL BRING COOL AND WET
CONDITIONS FOR MUCH OF THE UPCOMING WEEK. THE FIRST UPPER TROUGH
WILL MOVE ACROSS THE PACIFIC NW TODAY. A WARM FRONT APPROACHING THE
COAST WILL KEEP A THREAT FOR RAIN GOING TUE NIGHT INTO WED...THEN
ANOTHER COOL SHOWERY TROUGH IS EXPECTED FOR THE LATTER HALF OF THE
WEEK.
&&
.SHORT TERM...RAIN CONTINUED OVER MUCH OF THE FORECAST AREA EARLY
THIS MORNING AS A BROAD BAROCLINIC ZONE WAS SLOWLY PUSHING THROUGH.
WATER VAPOR PICTURES SHOWED A SLIGHTLY NEGATIVELY TILTED UPPER
TROUGH WAS E OF 130W APPROACHING THE COAST. SHOWER ACTIVITY ON IR
PICTURES WAS ISOLATED E OF 130W...BUT PICKED UP SOME FURTHER W. WILL
KEEP POPS HIGH OVER THE CASCADES THIS MORNING FOR THE DEPARTING
BAROCLINIC ZONE...BUT LIMIT POPS FURTHER W TO CHANCE CATEGORY.
DAYTIME WILL ALLOW AIR MASS TO DESTABILIZE SOME IN THE AFTERNOON AND
EARLY EVENING AS A SECONDARY TROUGH MOVES THROUGH...BRINGING BETTER
CHANCES FOR SHOWERS.
DEEPER MOISTURE MOVES IN LATER TUE NIGHT AND WED MORNING AS A LOW
LEVEL WARM AIR ADVECTION PATTERN SETS UP WITH THE APPROACHING RIDGE
ALOFT. BEST MOIST ISENTROPIC LIFT IS FOUND BETWEEN 285K AND 290K
ISENTROPIC SURFACES FROM LATE TUE NIGHT UNTIL WED EVENING. THIS
COUPLED WITH RATHER GENEROUS QPF FORECASTS IN ALL THE MODELS GIVES
HIGH CONFIDENCE FOR AN EXTENDED PERIOD OF RAIN WED. DEEP MOISTURE
REMAINS IN PLACE UNTIL THU MORNING...AS LIFTING MECHANISM SWITCHES
TO DYNAMICS GENERATED BY A COLD FRONT AND ACCOMPANYING SHORTWAVE THU
MORNING. THIS WILL KEEP POPS CATEGORICAL THROUGH THU MORNING.
SHOWERS LIKELY BEHIND THE FRONT THU AFTERNOON AS THE NEXT COLD UPPER
TROUGH DIGS IN TOWARDS THE COAST.
SNOW LEVELS WILL REMAIN BELOW CASCADE PASSES INTO WED...BEFORE
WARMER AIR PUSHES IN WED NIGHT AND EARLY THU. OROGRAPHICS WOULD
SUGGEST A FEW INCHES OF SNOW POSSIBLE BOTH TUE NIGHT AND WED AT THE
PASSES.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...THURSDAY NIGHT
THROUGH MONDAY... EXPECT COOL AND SHOWERY CONDITIONS FOR MOST OF THE
LONG TERM FCST PERIOD. A COLD FRONT IS EXPECTED TO PUSH EAST OF THE
REGION DURING THE DAY ON THU...WITH SHOWERS LINGERING THU NIGHT AND
FRI AS THE UPPER LEVEL TROF AND ASSOCIATED INSTABILITY PASS OVER THE
REGION. THERE MAY BE A BIT OF A BREAK TO START THE WEEKEND...BUT
ANOTHER FRONT IS PUSH ONSHORE LATE SAT OR SUN WHICH SHOULD BRING
ANOTHER ROUND OF MORE ORGANIZED PRECIPITATION. THE LATEST MODEL TREND
IS NOW TOWARD BUILDING AN UPPER LEVEL RIDGE OVER THE PAC NW TO START
NEXT WEEK. IT IS STILL QUITE A WAY OUT...SO IT THERE IS PLENTY OF
REASON NOT TO COMPLETELY BUY IN TO THIS SOLUTION...BUT STARTED TO
TREND THE FCST TOWARD DRIER AND WARMER FOR NEXT MON. PYLE
&&
.AVIATION...EXPECT MAINLY VFR CONDITIONS TODAY...WITH ONLY
TEMPORARY HIGH END IFR TO MVFR CONDITIONS POSSIBLE THIS MORNING.
THE NEXT FRONT WILL SPREAD STEADIER RAIN INTO THE TERMINALS THIS
EVENING WITH SUBSEQUENT MVFR REDUCTIONS POSSIBLE BETWEEN 06Z TO
12Z WEDNESDAY. HOWEVER...A DECENT SOUTH TO NORTH PRESSURE GRADIENT
AND RELATIVELY UNSTABLE LOWER ATMOSPHERE WILL MAKE IT TOUGH FOR
CONDITIONS TO DETERIORATE MUCH LOWER THAN MVFR.
KPDX AND APPROACHES...THERE IS A CHANCE A TEMPORARY IFR/MVFR CIG
COULD DEVELOP BETWEEN 800 AND 1500 FT FOR AN HOUR OR TWO THIS
MORNING DUE LIGHT RAIN SHOWERS CONTINUING TO MOISTEN THE LOWER
ATMOSPHERE...BUT CONFIDENCE IN TIMING THIS DEVELOPMENT REMAINS
LOW. OTHERWISE...EXPECT MAINLY VFR CONDITIONS THROUGH 06Z
WEDNESDAY AS THE LOWER ATMOSPHERE SHOULD REMAIN RELATIVELY
UNSTABLE. HOWEVER...A FRONT SHOULD SPREAD STEADIER RAIN INTO THE
TERMINAL THIS EVENING...WHICH MAY PRODUCE PERIODS OF MVFR
CONDITIONS BETWEEN 06Z AND 12Z WEDNESDAY. /NEUMAN
&&
.MARINE...WEST WINDS EARLY THIS MORNING WILL TURN SOUTHERLY TODAY AS
A WEAK LOW PRESSURE CREEPS EASTWARD TOWARDS VANCOUVER ISLAND.
EXPECT GUSTY 2O TO 30 KT WINDS TO DEVELOP SOON THEREAFTER. WINDS
MAY TEMPORARILY SUBSIDE TUESDAY NIGHT AS PRESSURE GRADIENTS
WEAKEN...BUT WINDS SHOULD PICK UP QUICKLY AROUND DAYBREAK AS
ANOTHER INCOMING FRONT TIGHTENS THE PRESSURE GRADIENT. A COASTAL
JET SHOULD ENHANCE WINDS WITHIN 20 NM OF THE COAST...PARTICULARLY
ACROSS THE CENTRAL OREGON WATERS...AND PERHAPS AS FAR NORTH AS THE
COLUMBIA RIVER. LATEST MODEL GUIDANCE SUGGESTS GALE FORCE GUSTS
ARE POSSIBLE...BUT DUE TO THIS EVENT LIKELY BEING ON THE LOWER END
OF GALE FORCE CRITERIA IF IT HAPPENS...WILL LET THE DAYSHIFT
INGEST ONE MORE ROUND OF MODEL RUNS BEFORE A WATCH OR WARNING IS
HOISTED.
EITHER WAY...WINDS MAY TEMPORARILY SUBSIDE WEDNESDAY EVENING...BEFORE
ANOTHER APPROACHING FRONT AND LOW PRESSURE BRINGS ANOTHER THREAT
OF LOW END GALE FORCE GUSTS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. SURFACE HIGH PRESSURE SHOULD THEN SPREAD INTO THE WATERS
THURSDAY NIGHT AND FRIDAY..BEFORE THE NEXT FRONTAL STORM SYSTEM
BRINGS POTENTIAL GALE FORCE WINDS SATURDAY. /NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO
11 PM PDT WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT EARLY
THIS MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 PM THIS AFTERNOON
TO 11 PM PDT WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM
THIS MORNING TO 1 PM PDT THIS AFTERNOON.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 10 PM
THIS EVENING TO 5 PM PDT WEDNESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
National Weather Service Spokane WA
244 AM PDT TUE APR 22 2014
.SYNOPSIS...
An active and wet spring weather pattern can be expected across
the Inland Northwest. A cold front will bring a good chance of
rain today followed by breezy winds. Scattered showers will fall
on Wednesday. Another Pacific storm will bring rain on Thursday,
with more showery conditions Friday and into the weekend.
&&
.DISCUSSION...
Today and tonight: a wet, breezy system moves across the Inland
Northwest. This morning a cold front was pushing into the
Cascades. It`s parent upper trough was moving onto the coastline,
with a 100kt jet streak on its southeast flank. The incoming
front, the diffluence in the LFQ of the jet and embedded impulses
in the southwesterly flow will mean deep-layer lift. Working with
PWATs between 0.50 to 0.75 inches (~150 to 200% of normal) this
will bring rain and higher mountain snow to the region through
this afternoon, before the threat wanes for some tonight.
Snow levels are forecast to be between 4-5kft near the Cascades
to near 6-7kft toward ID this morning. This afternoon and evening
snow levels to between 3.5-5kft this afternoon, before falling to
between 2-3kft overnight into Wednesday morning. Initially this
will mean the potential for light snow accumulations over the
Cascade passes, around Sherman Pass as the day progresses and
toward the Idaho Passes late this evening and overnight. Some may
even reach down to the higher valleys overnight, but by then the
threat of significant precipitation will have ended.
Precisely timing the precipitation will be the trickier part. Yet
thus far the HRRR model has been doing a reasonable approximation
of the near-term precipitation evolution. Following that guidance
and a radar extrapolation, I`m expecting precipitation to continue
moving north through the northern Cascades and Okanogan Valley and
Highlands early this morning. A second area of precipitation is
expected to expand north-northeast across the Upper Columbia Basin
and Blues into Spokane/C`DA area early this morning, then into the
northeastern WA mountains and ID Panhandle toward 15Z (8 AM PDT).
Between late morning and early afternoon, the cold front and upper
trough start to push east of the Cascades, allowing precipitation
to decrease to more widely scattered to isolated showers near the
Cascades and western Basin. Then late this afternoon and early
evening, the front pushes east toward the ID/MT border and the
primary upper trough axis will be on its heels. This will allow
the precipitation focus to back against the Cascades and into the
northeast and eastern mountains, while activity elsewhere becomes
more showery and dissipates into the evening. Overnight a second
shortwave disturbance pushes into the Cascades, renewing the
precipitation threat here and over the western Basin. The best
threat will remain in the Cascades. Further east the shower threat
lingers near the ID/MT border, but otherwise drier weather is
expected until Wednesday morning.
There were some isolated lightning strikes late Monday night into
early Tuesday morning south of our region. Toward midday/afternoon,
models depict some pockets of marginally favorable CAPE/LI values
across northeast WA/ID. However it is nothing really comparable to
the convective instability that was associated with the lightning
I was seeing south of our region last night. So my confidence that
it will result in some thunder in our region is low. So I have
elected to leave thunder out of the forecast for now. This will be
monitored.
The other issue of the day will be winds. As the front and upper
trough sweep in a second low pressure begins to develop east of
the Divide. The resulting tightening gradient and mixing along the
front will allow winds to increase through the late morning and
early afternoon. As for the numbers: sustained winds of of 15-25
mph, with gusts between 25-35 mph will be possible, especially
between about midday to 7 or 8 pm. The gradient slackens some
going into this evening which should allow for a decline in the
overall winds. /J. Cote`
Wed through Sunday: As the cold upper trough moves NE into Wrn
Montana Wed morning, we`ll slowly transition from a highly
convective regime to a more stable pattern under short-wave
ridging. The valleys of the north Idaho Panhandle and NE Wa Wed
morning are still under a threat of snow showers. But most likely
any significant accumulations will be limited to the mountains
above about 3k ft. The wrn end of the trowal structure that wraps
around the upper low nearly stalls across the BC border with Idaho
well into Wed. Lingering rain/snow is the result for the
aforementioned valleys and mtns. A quick- moving short-wave trough
also tracks SE through SE Wa and NE Oregon Wed, increasing the
chances of pcpn as backing winds increase isentropic ascent.
Beginning Wed Nt, a more widespread stratiform pcpn event will
keep high chances of pcpn in the fcst for most zones... especially
Thurs as deep isentropic ascent over an advancing warm front, then
an occluding cold front, moves NE across the region. Warm
advection is sufficient to put much of SE Wa in the warm sector
south of the warm front. Due to the shearing/splitting of the
accompanying upper trough in response to a jet speed max digging
toward northern California Thurs Nt, the occluded front will stall
directly across Ern Wa and N Idaho. This slowly weakening boundary
won`t begin to move out of the area until Sat, leading to a very
cool and showery Fri and Sat. There is also a significant vort max
that moves north into Ern Wa Fri as well, enhancing the prolonged
pcpn threat. Temperatures will remain below normal for most areas,
a result of the numerous short-waves... then the stalling front
Fri through the weekend. bz
Sunday Night through Tuesday: Region looks to be in a transition
period as we finally start to exit the very active and wet period
for more of a dry and much calmer pattern. Beginning Sunday night,
the large scale trough dipping down from the Gulf of Alaska
appears to be held at bay by a building ridge from the south.
Mainly remnant moisture remains which is one reason low chance
POPs were kept through Monday. Also as the ridge continues to
grasp control of the pattern, the jet will pass right over the
region Monday bringing some better dynamics. Both the Euro and
GFS currently agree on the solution of the building ridge allowing
for some confidence. Any notable precip looks to remain on the
west side of the Cascades. Moving into Monday night and Tuesday
the ridge continues to control with lowering chances for precip as
time passes. Changes to the forecast include lowering POPs Monday
night and Tuesday while also lowering winds. As the ridge builds,
we should finally start to see temps climb back to near or
slightly above normal. With this forecast in the far extended
major shifts in the models are still possible, but for now this
period could be a nice break from the active, wet weather noted in
the previous week. /Fliehman
&&
.AVIATION...
06Z TAFS: Precipitation associated with a slow moving cold front
has started at KEAT and KMWH. An area of heavy rain will approach
these terminal sites around 07Z with MVFR cigs possible. The area
of precipitation will move east and bring lowering ceilings and
rain to the eastern TAF sites between 12Z and 18Z Tuesday. Post
frontal winds will shift to the southwest and increase after 17Z
with gusts to 25 kts common. At KEAT downsloping winds will be out
of the northwest with gusts increasing to 35 kts and possibly
higher in the late afternoon Tuesday. Scattered instability showers
will be possible throughout the afternoon in a post frontal air
mass. Winds will diminish after 03Z Wednesday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 51 34 50 40 53 39 / 90 20 60 20 90 60
Coeur d`Alene 52 33 50 39 52 38 / 90 50 60 20 90 70
Pullman 51 35 51 42 52 40 / 90 30 60 30 90 60
Lewiston 57 39 56 46 58 44 / 90 20 60 40 80 60
Colville 58 32 58 36 57 39 / 90 30 40 10 90 40
Sandpoint 54 33 49 37 51 40 / 90 50 60 20 90 60
Kellogg 52 32 46 37 49 38 / 100 90 70 40 80 60
Moses Lake 60 39 62 44 64 38 / 60 20 10 40 50 10
Wenatchee 59 42 60 45 62 41 / 50 20 20 50 50 10
Omak 58 34 61 39 60 37 / 70 20 20 20 90 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1249 AM CDT THU APR 24 2014
.DISCUSSION...
931 PM CDT
SHOWERS CONTINUE TO MOVE/DEVELOP EASTWARD ACROSS NORTHERN ILLINOIS
EARLY THIS EVENING WITHIN A ZONE OF INCREASING ISENTROPIC ASCENT
ALONG THE WESTERN PERIPHERY OF A SURFACE RIDGE OF HIGH PRESSURE. THIS
ACTIVITY IS EXPECTED TO CONTINUE MOVING EASTWARD ACROSS NORTHERN
ILLINOIS LATE THIS EVENING...AND LIKELY ENDING PRIOR TO DAYBREAK
THURSDAY AS THE BETTER FORCING AND MOISTENING SHIFTS TO THE NORTH
AND EAST OF THE REGION. THEREFORE...NO BIG CHANGES ARE NEEDED TO THE
GOING FORECAST FOR TONIGHT.
THURSDAY IS SHAPING UP TO BE A BREEZY AND A MILDER DAY ACROSS THE
AREA AS SOUTHEASTERLY FLOW RAMPS UP IN RESPONSE TO AN AREA OF LOW
PRESSURE APPROACHING WESTERN ILLINOIS DURING THE AFTERNOON. IT
APPEARS THAT IN SPITE OF THE SOUTH-SOUTHEASTERLY WIND
COMPONENT...THAT WINDS COULD BE VERY GUSTY...UP IN THE 30 TO 35 KT
RANGE...DURING THE AFTERNOON. ALSO...IT APPEARS THAT THESE
SOUTHEASTERLY WINDS WILL TRANSPORT A DRIER LOWER LEVEL AIR MASS IN
ACROSS THE AREA DURING THE DAY...AND THIS COULD LEAD TO LOWER
SURFACE DEW POINTS THAN CURRENTLY FORECAST...ESPECIALLY ACROSS THE
EASTERN HALF OF THE AREA. WITH THIS IN MIND...I HAVE BACKED OFF ON
POPS DURING THE AFTERNOON THURSDAY...WITH A LIKELY SLOWER EVOLUTION
OF THE PRECIPITATION. IT APPEARS THE MAIN FORCING AND MOISTURE WILL
NOT ARRIVE ACROSS THE AREA UNTIL THURSDAY EVENING. AT THIS TIME I
HAVE LEFT SOME LOW END POPS IN DURING THE AFTERNOON...BUT IF THESE
TRENDS CONTINUE...WE MAY BE ABLE TO GO DRY ALL AFTERNOON ON
THURSDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA. PERIODS
OF RAIN STILL APPEAR TO BE A GOOD BET THURSDAY NIGHT.
KJB
//PREV DISCUSSION...
310 PM CDT
SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE
WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW
AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK.
THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS
AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST
HALF OF NEXT WEEK.
REST OF TODAY AND TONIGHT...
A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE
HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD
TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO
VALLEY THROUGH EASTERN QUEBEC.
A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH
SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH
EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE
SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH
THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM
CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE
REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL
SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER
LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT
AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE
BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES
DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP
ACCUMULATIONS.
CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN
TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA.
TOMORROW AND TOMORROW NIGHT...
AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE
TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW
ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE
US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS
THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE
HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY
ADJUSTMENTS.
RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND
EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE
SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER
HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN.
WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF
THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON
WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX
TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT
70 IN THE SOUTHERN CWA.
FRIDAY AND SATURDAY...
THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY
SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND
EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS
WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE
SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT.
THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX
TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD
FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE
MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR
NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING
LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY
FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN
NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER
30S TO MID 40S.
SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY
MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW
CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR
BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER
40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN
THE OUTLYING AREAS.
GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY
NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT
LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE
FROM THE UPPER 30S TO THE MID 40S.
EXTENDED...SUNDAY THROUGH TUESDAY...
AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY
EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK
BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST
MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE
SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY
NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS
PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY.
IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER
NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON
SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE
REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE
OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF
THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED
INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS
SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH
TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS
WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING
TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL
REMAIN ABOVE FREEZING.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIODS OF LIGHT RAIN THROUGH EARLY THIS MORNING.
* STRONG/GUSTY SOUTHEAST WINDS TODAY.
* SHRA LATER THIS EVENING W/ ISOL TSRA.
* POSSIBLE LOW END MVFR CEILINGS LATE IN THE FORECAST PERIOD.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
TERMINALS REMAIN ON EASTERN FRINGE OF PERSISTENT SHOWER
DEVELOPMENT AT THIS HOUR...AND NOW EXPECT THIS TO CONTINUE OVER
THE NEXT COUPLE OF HOURS BEFORE THIS PRECIP SHIELD ALL LIFTS TO
THE NORTH OF THE TERMINALS LATER THIS MORNING. ALTHOUGH...STILL
CONFIDENT THIS WILL REMAIN LIGHT WITH VFR CONDITIONS CONTINUING.
A LULL IN THE ACTIVITY AS WELL AS CLOUD COVER WILL LIKELY OCCUR
FOR THE REMAINDER OF THE DAY BEFORE THE NEXT SYSTEM CURRENTLY WELL
WEST OF THE TERMINALS SLOWLY APPROACHES. VFR CEILINGS WILL RETURN
LATE THIS AFTERNOON INTO THE EVENING AS WELL AS
SHOWER/THUNDERSTORM CHANCES. MAINTAINED JUST SHOWERS IN THE TAFS
WITH LOW CONFIDENCE OF TSRA AT THIS TIME...WITH EVEN SOME
POSSIBILITY OF DELAYING THE ONSET OF VCSH/-SHAR WITH LATER
FORECASTS. SOUTHEAST WINDS WILL RAMP UP RATHER QUICKLY LATER THIS
MORNING WITH STRONG GUSTS TO AROUND 30 KT LIKELY BEFORE A SLOW
DOWNWARD TREND OCCURS LATER THIS AFTERNOON. WITH CONFIDENCE LOWER
WITH REGARDS TO OVERALL TIMING OF THIS SYSTEM...HAVE LEFT OUT ANY
MENTION OF WIND SHIFT TO THE NORTHWEST AND POSSIBLE LOW END MVFR
CEILINGS VERY LATE IN THE FORECAST PERIOD FOR ORD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH RAIN AND VFR CONDITIONS.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* HIGH CONFIDENCE WITH SHOWERS LATER THIS EVENING...WITH LOW
MEDIUM CONFIDENCE ON EXACT TIMING AND TSRA.
* LOW CONFIDENCE WITH LOW END MVFR CEILING CHANCES.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...DRY/VFR.
* SUNDAY THROUGH TUESDAY...CHANCE OF SHRA. MVFR POSSIBLE.
&&
.MARINE...
219 PM CDT
PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE
AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL
BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL
PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS
WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD
BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE
AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH
SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE
WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET
LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE
GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS
EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL
PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM THURSDAY TO 10 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
343 AM CDT THU APR 24 2014
.SHORT TERM /TODAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
PRIMARY CONCERNS TODAY WILL BE INTERRELATED PRECIP AND TEMP TRENDS
WITH NOT THE GREATEST CONFIDENCE IN EITHER...ESPECIALLY TEMPS. LONG
WAVE TROUGH IS STILL WELL TO THE WEST JUST EXITING THE ROCKIES AND
ASSOCIATED KINEMATIC FORCING SEEMS TO BE THE MAIN MECHANISM DRIVING
CURRENT KS/NE PRECIP BEHIND THE INVERTED TROUGH. THERMODYNAMIC
FORCING SEEMS TO BE MAINLY RESPONSIBLE FOR IA/MN PRECIP AND LOOKS TO
GRADUALLY BECOME THE DOMINATE FORCING LATER IN THE DAY. EXPECT THE
NE/KS PRECIP TO WANE AND BE REPLACED BY WEAK CONVECTION NOW
INCREASING SOMEWHAT ALONG THE I35 CORRIDOR AND MOISTURE TRANSPORT
AXIS. LATEST HIGH RES MODELS SEEM TO HAVE A DECENT HANDLE ON THIS
PROGRESSION AS WELL...WHICH EVENTUALLY ENDS UP WITH LINGERING POPS
IN THE EAST 21Z-00Z. INSTABILITY IS FAIRLY WEAK AT THE MOMENT WITH
MUCAPES JUST A FEW HUNDRED. MAX AXIS...STILL ONLY AROUND 500
J/KG...IS STILL OFF TO THE WEST HOWEVER SO THERE MAY BE A MINOR
UPTICK IN INTENSITY THROUGH THE MORNING WITH SOME SMALL HAIL
POSSIBLE...STILL BELOW SEVERE LIMITS. THE ERN THIRD OF THE FORECAST
AREA MAY SEE ANOTHER HALF INCH PLUS OF BENEFICIAL RAINS.
TEMP GUIDANCE IS QUITE VARIED WITH A DECENT SPREAD IN BOTH RAW AND
MOS VALUES. 8F DIFFERENCE IN DSM MOS FOR INSTANCE. SOME
MODELS...ESPECIALLY RECENT RAP RUNS...WERE MORE AGGRESSIVE MIXING
TODAY WHILE OTHERS KEEP MORE LOW LEVEL MOISTURE IN PLACE. DO NOT
REALLY HAVE A GOOD FEELING WHICH WAY TO LEAN HERE SO FOLLOWED MORE
OF A BLEND...WHICH IS JUST SLIGHTLY LOWER THAN PERSISTENCE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
SYSTEM SHOULD QUICKLY EXIT THE STATE THIS EVENING...WITH SOME
LINGERING LIGHT SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE
FAR SOUTHEASTERN CWA EARLY IN THE EVENING. OTHERWISE UPPER LEVEL
RIDGING TO BUILD INTO THE CENTRAL US FRIDAY INTO SATURDAY...WITH WAA
AND DRY CONDITIONS EXPECTED. HIGHLY AMPLIFIED LONGWAVE UPPER LEVEL
TROUGH STILL EXPECTED TO DIG INTO THE DESERT SOUTHWEST
SATURDAY...WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE CENTRAL
US LATE SATURDAY NIGHT INTO SUNDAY. ALL MODELS EJECTING THIS SYSTEM
INTO THE WESTERN HIGH PLAINS BY SUNDAY AND SLOWLY MOVE IT EAST
NORTHEASTWARD INTO EARLY NEXT WEEK. THIS WILL SET UP A WET ACTIVE
PATTERN ACROSS THE REGION/STATE BY LATE SATURDAY NIGHT INTO EARLY
NEXT WEEK.
FINER DETAILS STILL TO BE DETERMINED WITH SOME UNCERTAINTY IN HOW
FAR THE SFC FRONT WILL PUSH NORTHWARD SUNDAY INTO MONDAY. FOR NOW
MODELS JUST BRING THE SFC FRONT INTO EXTREME SOUTHERN IOWA LATE
SUNDAY INTO MONDAY. INSTABILITY INCREASES ACROSS THE AREA WITH
STRONG PUSH OF MOISTURE NORTHWARD FROM THE GULF AND WAA ALOFT SHOULD
SEE DECENT CHANCE FOR THUNDER ACROSS THE ENTIRE CWA. AS SYSTEM
BECOMES MORE WRAPPED UP AND SLOWLY TRANSLATES EAST INTO LATE MONDAY
THROUGH WEDNESDAY...THREAT OF THUNDER DECREASES WITH MORE STRATIFORM
RAIN EXPECTED. AS THE UPPER LEVEL SYSTEM PUSHES EVER SLOW SLOWLY
EASTWARD...REGION SHOULD REMAIN UNDER THE INFLUENCE OF UPPER LEVEL
CYCLONIC FLOW THROUGH MUCH OF NEXT WEEK WITH A WET AND COOLER
PATTERN EXPECTED.
&&
.AVIATION...24/06Z
ISSUED AT 1203 AM CDT THU APR 24 2014
LOW PRESSURE OVER CENTRAL KS WITH COLD FRONT FROM ERN SD THROUGH
THE LOW INTO THE TX PANHANDLE WILL MOVE EAST TO CENTRAL IA BY
EARLY THU AFTERNOON...AND EAST OF THE TAF SITES BY EVENING.
DETERIORATING CONDITIONS TONIGHT AS MOISTURE AND THUNDERSTORMS
INCREASE AHEAD OF THE FRONT. SEVERAL HOURS OF MVFR CIGS AROUND THE
FRONT. CONDITIONS WILL IMPROVE QUICKLY OVER WRN IA THU
AFTERNOON...AND IN THE EAST BY EVENING.
OUTLOOK...WEAK HIGH PRESSURE WILL MOVE OVER THE STATE ON FRIDAY
WITH GOOD VFR CONDITIONS AND LIGHT WINDS. VFR INTO SATURDAY BEFORE
NEXT WEATHER SYSTEM MOVES IN ABOUT SAT NIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...MS APR 14
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1245 AM CDT Thu Apr 24 2014
...Updated Aviation Section...
.SHORT TERM...(This evening through Thursday)
ISSUED AT 142 PM CDT WED APR 23 2014
RAP, HRRR, and NAM all suggesting dryline will be located near
Garden City and Liberal between 21Z Wednesday and 00z Thursday.
Convective initiation along this boundary however somewhat more
uncertain given the warm 700mb temperatures and cloud
cover/precipitation currently over portions of southwest Kansas.
At this time based on the ARW,NMM, and HRRR still suggests there
will be some widely scattered convection developing late day/early
this evening. Will therefore follow the general trend of the non
hydrostatic models for for late today/early tonight but keep
precipitation chances more widely scattered. Mid level instability
and shear continues to support that if storms do develop they will
be capable of becoming severe. Main hazard early tonight still
appears to be hail and strong winds given shear, mid level
instability, high cloud bases, downdraft capes, and model
soundings at 00z Thursday.
A cold front crossing northwest Kansas earlier this afternoon is
forecast to cross southwest Kansas between 00z and 09z Thursday.
Convection along this cold front is expected to develop late day
and increase in areal coverage early tonight as an upper level
trough, which was located near the four corners region as 12z
Thursday, moves east across the Central High Plains. This cold
front will provide the better opportunity for precipitation,
especially along and east of a Dighton to Liberal line based on
where the better low level moisture is forecast to be early tonight
by the NAM. Precipitation chances will begin to taper off from
northwest to southeast, mainly after midnight as this cold front
surges south.
Behind this cold front very windy conditions are expected to
develop given the pressure tendencies and 925 to 850mb winds. Wind
speeds of 30 to 35 mph will be likely for several hours behind
this front, especially west of highway 283 between 03z and 09z.
After 09z Thursday the winds will begin to decrease and are
expected to continue to decrease during the day on Thursday as a
surface high/ridge axis crosses western Kansas. NAM and GFS 850mb
mixdown temperatures and guidance was with 2-4 degrees of each
other for highs on Thursday so given this and the expected
sunshine Thursday afternoon will stay close to what they suggest.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 255 PM CDT WED APR 23 2014
Medium range models indicate weak upper level ridging transitioning
eastward across the Western High Plains Friday and into the Central
Plains Saturday. Meanwhile, a strong upper level trough of low
pressure will begin to push ashore into southern California Saturday
setting up a southwest flow across the Western High Plains by
Saturday afternoon. As a lack of significant low/mid level moisture
prevails during this time frame, dry conditions will persist through
Saturday afternoon. The potential for thunderstorms returns Saturday
evening as the upper level trough begins to lift northeast out of
the Desert Southwest into the Western High Plains. As the shortwave
approaches, a prevailing low level southeasterly flow will continue
to draw moisture northward into Kansas ahead of a sharpening dryline.
Although where the dryline sets up is uncertain this far out, the
likelihood for thunderstorm development is good ahead of it as upper
level dynamic support becomes more favorable. Severe weather is
possible late Saturday into early Sunday morning. Precip potential
shifts north and east Sunday as the upper level trough lifts
northeast across the Western High Plains increasing the potential
for dryslotting across southwest Kansas.
Temperatures will be above normal Friday as weak upper level ridging
moves eastward out of the Rockies across the Western High Plains. A
south to southeasterly flow will return to western Kansas as lee
side troughing redevelops across eastern Colorado. This will draw
warmer air north into the area with H85 temperatures ranging from
around 20C across central Kansas to near 25C in far southwest
Kansas. Look for highs well up into the 80s(F) Friday afternoon.
The warming trend continues into Saturday as enhanced warm air
advection raises H85 temperatures into the mid to upper 20s(C)
across southwest Kansas. Mid to upper 80s(F) are likely Saturday
afternoon with the lower 90s(F) possible behind a dryline across
extreme southwest Kansas. Much cooler temperatures will arrive
early next week as a cold front sweeps through western Kansas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1244 AM CDT THU APR 24 2014
A strong cold front will continue surging southward over western
and central Kansas into the overnight hours. Behind this boundary
a band of thunderstorms will move through the HYS and DDC terminals
through the mid overnight hours. MVFR ceilings and wind gusts up
to 50-60 mph will be possible within these thunderstorms. Further,
strong north to northwest winds of 25-35 mph along with higher
gusts will also be possible behind the front through the remainder
of tonight. High pressure will then build into the region later
this afternoon with winds easing quickly while an unlimited
ceiling develops.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 84 54 88 / 0 0 0 20
GCK 43 84 50 86 / 0 0 0 10
EHA 46 85 52 89 / 0 0 0 10
LBL 44 86 53 90 / 0 0 0 10
HYS 43 81 51 82 / 0 0 0 20
P28 46 85 58 90 / 0 0 0 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 2 AM CDT /1 AM MDT/ early this morning FOR
KSZ043-044-061>063-074>076-084>086.
&&
$$
SHORT TERM...Burgert
LONG TERM...JJohnson
AVIATION...AJohnson
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1206 AM CDT THU APR 24 2014
.DISCUSSION...
24/06Z TAF ISSUANCE.
&&
.AVIATION...
SATELLITE IMAGERY LATE THIS EVENING SHOWS A FEW LOW CLOUDS
BEGINNING TO STREAM IN OFF THE GULF WHILE VEIL OF CIRRUS MOVES IN
FM THE WEST. OBS SITES CONTINUE TO SHOW P6SM VISBYS. ADJUSTED
VISBY FCST FOR TONIGHT AS STRENGTHENING LOW LVL JET AND INCREASING
CLOUDS ACRS SE TX WILL LIMIT FOG DEVELOPMENT AT BPT AND LCH.
FURTHER EAST...FOG STILL COULD BE AN ISSUE DUE TO LIGHTER WIND
FIELD/LESS CLOUD COVER AND LATEST HRRR VISBY PROGS ALSO REFLECT
THIS. WITH THIS IN MIND...KEPT VFR CONDITIONS AT BPT...PREVAILING
VFR/TEMPO MVFR AT LCH WITH PREVAILING MVFR/TEMPO IFR AT ERN SITES.
FOG EXPECTED TO LIFT TO MVFR CIGS BY 14Z-15Z...THEN BECOMING VFR
BY 18Z WITH SLY WINDS 10-15 KT GUSTING TO 20-25 KT DURING THE
AFTN. WINDS WILL DIMINISH SLIGHTLY DURING THE EVENING AS A WEAK
FRONT APPROACHES THE AREA...WITH LOW CIGS RETURNING. 24
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT WED APR 23 2014/
UPDATE...
HIGH PRESSURE OVER THE NORTHERN GULF IS ALLOWING FOR MOISTURE TO
MOVE INLAND OVER SOUTHEAST TEXAS AND SOUTHERN LOUISIANA THIS
EVENING. ANOTHER BEAUTIFUL DAY TODAY SAW TEMPERATURES CLIMB INTO
THE 80S UNDER SUNNY SKIES AFTER THE FOG BURNED OFF THIS MORNING.
THE FRONT THAT WAS TO OUR SOUTH HAS MOVED BACK NORTHWARD AND
EXTENDS FROM SOUTHEAST OKLAHOMA INTO SOUTH-CENTRAL MISSISSIPPI
THIS EVENING.
MODELS ARE HINTING AT MORE FOG ON TAP TONIGHT WITH SOME AREAS
FALLING BELOW ONE MILE TOWARDS SUNRISE. TEMPS EXPECTED TO RANGE
FROM THE MID TO UPPER 60S AT THE COAST TO NEAR 60 ACROSS THE LAKES
REGION OF SOUTHWEST TEXAS AND CENTRAL LOUISIANA. ANOTHER FRONT
LOOKS TO APPROACH FROM THE NORTHWEST BY EARLY FRIDAY MORNING
BEFORE STALLING OVER THE COASTAL WATERS. NOT LOOKING FOR ANY REAL
CHANCE AT PRECIP AND TEMPS WILL NOT SHOW MUCH VARIATION...BUT
DRIER AIR WILL SET IN FOR FRIDAY. THE HIGH PRESSURE WILL MOVE
QUICKLY OFF TO THE EAST WITH RETURN FLOW ON SATURDAY MORNING.
RETURN MOISTURE WILL MOVE UP FROM DEEP SOUTH TEXAS AND INTO
EASTERN TEXAS BY EARLY SUNDAY MORNING. THIS WILL ESTABLISH A
DEEPER MOISTURE PROFILE WITH THE CHANCE FOR SOME SHOWERS SUNDAY
AFTERNOON/EVENING TIME-FRAME. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO MONDAY AS ANOTHER FRONT THIS TIME
STRONGER WILL PUSH THROUGH THE REGION. TEMPERATURES WILL COOL ON
TUESDAY WITH WEDNESDAY MORNING SEEING TEMPS STARING OUT IN THE LOW
50S CENTRAL LOUISIANA WITH MID 50S DOWN ALONG THE I-10 CORRIDOR.
19
PREV DISCUSSION... /ISSUED 645 PM CDT WED APR 23 2014/
DISCUSSION...
23/00Z TAF ISSUANCE.
AVIATION...
AFTN CU FIELD BEGINNING TO DISSIPATE WITH THE LOSS OF DAYTIME
HEATING...WITH VFR CONDITIONS EXPECTED FOR THE REMAINDER OF THE
EVENING. SLY WINDS CONTINUE TO USHER PLENTY OF LOW LVL MOISTURE
INTO THE REGION. WINDS WILL LIGHTEN DURING THE EVENING WITH FOG
EXPECTED TO DEVELOP BY MIDNIGHT. THE ONSET OF FOG LOOKS MORE
LIKELY AT THE ERN TERMINALS TONIGHT WITH LOW LVL WINDS
STRENGTHENING TO THE WEST RESULTING IN MORE OF A LOW CIG AT KBPT
ALTHOUGH OCCASIONAL PERIODS OF FOG CANNOT BE RULED OUT.
OTHERWISE...FEW CHANGES TO REMAINDER OF FCST WITH FOG/CIGS LIFTING
THU MORNING AND SLY WINDS STRENGTHENING...BECOMING GUSTY DURING
THE AFTN AS THE NEXT WEAK FRONT APPROACHES THE AREA. 24
PREV DISCUSSION... /ISSUED 421 PM CDT WED APR 23 2014/
DISCUSSION...PLEASANT AFTERNOON ACROSS THE FORECAST AREA.
TEMPERATURES GENERALLY RUNNING IN THE LOW 80S AND HUMIDITY LEVELS
ON THE LOW SIDE WITH DEWPOINTS RANGING FROM THE MID 50S INTO THE
LOWER 60S. SATELLITE IMAGERY DEPICTING SCATTERED CU ACROSS THE
REGION. SOME ENHANCEMENT OF THE CU NOTED FROM LOWER ACADIANA WEST
NORTHWEST INTO INTERIOR SOUTHEAST TEXAS. THIS MARKING THE
RETREATING FRONTAL BOUNDARY.
A FAIRLY QUIET WEATHER PATTERN AHEAD FOR THE REMAINDER OF THE
WEEK. TEMPERATURES ANTICIPATED TO GENERALLY REMAIN A FEW DEGREES
ABOVE THE NORM AS A DEEPENING SOUTHERLY FLOW BECOMES ESTABLISHED.
STEADY ONSHORE FLOW WILL PROVIDE A DAILY CHANCE OF NIGHT-TIME
ADVECTION FOG DEVELOPMENT. BOUNDARY LAYER WINDS MAY JUST BE HIGH
ENOUGH FOR STRATUS RATHER THAN FOG BUT TOO CLOSE OF A CALL AT
THIS TIME. CARRYING PATCHY FOG TONIGHT.
NEXT MID/UPPER LEVEL TROF ADVANCING THROUGH THE CENTRAL CONUS WILL
SWING AN ACCOMPANYING WEAK SURFACE TROF ACROSS THE FORECAST AREA
LATE THURSDAY NIGHT. HAVE MAINTAINED LOW END POPS FOR THURSDAY
AFTERNOON AND EVENING WITH FEATURES OVER CENTRAL LOUISIANA INTO
INTERIOR SOUTHEAST TEXAS. MOISTURE/LIFT AT THIS TIME APPEARS TO
LIMITED FOR MENTIONABLE POPS FURTHER SOUTH. PASSAGE WILL BRING
NORTHING MORE THAN A VERY BRIEF AND LIMITED LOWERING OF DEWPOINTS.
VIGOROUS SYSTEM DEVELOPING AND ADVANCING THROUGH THE PLAINS WILL
SWING ANOTHER COLD FRONT THROUGH THE AREA MONDAY. RAIN CHANCES
INCREASE SUNDAY AND MONDAY.
MARINE...AN ONSHORE FLOW WILL RETURN TODAY AS HIGH PRESSURE BECOMES
REESTABLISHED IN THE WAKE OF A WARM FRONT ADVANCING INLAND FROM
THE NORTHWEST GULF. WINDS WILL STRENGTHEN AND SEAS BUILD THROUGH
THE WEEKEND IN ADVANCE OF OUR NEXT FRONTAL PASSAGE EXPECTED LATE
MONDAY. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 62 81 64 82 / 0 10 20 10
KBPT 64 80 65 81 / 0 10 10 10
KAEX 60 84 63 83 / 0 20 20 10
KLFT 64 81 65 82 / 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 417 AM EDT THU APR 24 2014
MAIN FCST CONCERNS IN THE LONG TERM ARE FOCUSED ON POPS/PTYPE/
ADDITIONAL SN AMOUNTS ON FRI/FRI NGT. HUDSON BAY HI PRES SHOULD
BRING A DRY BUT COOL PERIOD OF WX THIS WEEKEND INTO EARLY NEXT WEEK.
FRI...WARM CONVEYOR BELT RIBBON OF MSTR WITH H7 SPECIFIC HUMIDITY AS
HI AS 4G/KG AND DEEP LYR QVECTOR CNVGC UNDER DIFFLUENT UPR FLOW
AHEAD OF STRONG SHRTWV MOVING THRU WRN LK SUP ARE FCST TO STILL BE
INFLUENCING THE KEWEENAW AND MUCH OF THE E HALF OF THE CWA AT
12Z ON FRI...WITH MID LVL DRY SLOTTING ON THE SRN FLANK OF THE
SHRTWV IMPACTING AREAS NEAR THE WI BORDER. EXACTLY HOW FAR N OR S
THIS SHRTWV TRACKS W-E THRU UPR MI WL INFLUENCE HOW LONG HEAVIER
PCPN UNDER THE WARM CONVEYOR BELT CAN LINGER AT ANY GIVEN
POINT...WITH LOCATIONS TO THE S OF THE H7 LO TRACK UNDER MORE
AGGRESSIVE MID LVL DRY SLOTTING SEEING A QUICKER END TO THE HEAVIER
PCPN. THE 00Z NAM/GFS/HIER RES CNDN MODEL/LOCAL WRF ARW/ECMWF HAVE
ALL TRENDED FARTHER TO THE N WITH THE SHRTWV/H7 LO TRACK AND SHOW
AGGRESSIVE MID LVL DRYING MOVING W-E THRU UPR MI AND QUICKLY
DIMINISHING THE PCPN BY EARLY AFTN EXCEPT PERHAPS FOR SOME SCT RA/SN
SHOWERS OVER THE N AND ESPECIALLY THE KEWEENAW CLOSER TO THE PATH OF
THESE FEATURES. WITH MORE AGGRESSIVE MID LVL DRYING AND LESS
PCPN...BUMPED UP FCST HI TEMPS FOR ALL BUT THE NRN CWA EVEN THOUGH
LINGERING LLVL MSTR WL ALLOW FOR A GOOD DEAL OF SC TO LINGER UNDER
STRENGTHENING MID LVL INVRN. THE WARMEST AREA WL BE OVER THE
SCENTRAL...WHERE DOWNSLOPING WNW FLOW WL ALLOW FOR MORE BREAKS IN
THE CLDS/WARMING. INCREASED HI TEMPS INTO THE 50S IN THIS AREA.
FRI NGT...STEADY HGT RISES/DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF
THE DEPARTING SHRTWV TO THE E WL BE INFLUENCING UPR MI...BUT SOME
MODELS INCLUDING THE 00Z GFS SHOW ANOTHER SHRTWV SLIDING SEWD THRU
THE UPR LKS IN THE WAKE OF THE LEAD DISTURBANCE BRINGING MORE DEEPER
MSTR/SOME HEAVIER PCPN TO THE AREA. GIVEN THE STRENGTH OF THE LEAD
SHRTWV AND FAIRLY AGGRESSIVE DEEP LYR QVECTOR DVGC IN ITS WAKE...
PREFER THE 12Z ECWMF/00Z NAM THAT SUPPRESS THIS SECOND DISTURBANCE
AND MAINTAIN MORE MID LVL DRYING. HOWEVER...LINGERING CYC LLVL NE
FLOW IN THE PRESENCE OF LINGERING LLVL MSTR MAY ALLOW FOR SOME LGT
RA/SN SHOWERS TO PERSIST IN THE UPSLOPE AREAS NEAR LK SUP FOR A GOOD
PORTION OF THE NGT.
SAT...SFC HI PRES IS FCST TO BUILD OVER HUDSON BAY...WITH SFC RDG
AXIS EXTENDING S INTO THE UPR LKS UNDER STEADILY RISING HGTS...IN
LINE WITH GOING DRY FCST. ALTHOUGH THERE MAY BE SOME LINGERING LO
CLDS MAINLY NEAR LK SUP IN LLVL NNE FLOW WITHIN SHALLOW COOL LYR
UNDER LOWERING/STRENGTHENING INVRN...THESE CLDS SHOULD BURN OFF WITH
DAYTIME HEATING. DESPITE THE RETURN OF SOME AFTN SUNSHINE...
LOCATIONS NEAR LK SUP WL BE QUITE CHILLY WITH H85 TEMPS RISING NO
HIER THAN -3C AND THE LLVL NNE FLOW OFF THE WATER STILL COVERED WITH
A GOOD DEAL OF ICE. HELD FCST HI TEMPS IN THE WELL BLO NORMAL
MID-UPR 30S NEAR LK SUP.
SAT NGT/SUN...LONGER RANGE MODELS ARE VERY CONSISTENT SHOWING UPR
RDG BLDG OVER SCENTRAL CANADA INTO THE GREAT LKS TO THE NE OF POTENT
SHRTWV EMERGING OUT OF THE DESERT SW INTO THE CENTRAL PLAINS. BUT A
GOOD NUMBER OF THE EXTENDED MODELS SHOW DEEPER MSTR RETURNING TO THE
UPR GRT LKS WELL TO THE NE OF THE CLOSED LO. GIVEN THE TREND TOWARD
BLDG RDG AND PRESENCE OF HUDSON BAY HI PRES WITH DRY ENE LLVL FLOW/
SPRING CLIMATOLOGY FOR HUDSON BAY HI PRES...SUSPECT THE 00Z ECWMF IS
ON THE RIGHT TRACK WITH A DRY FCST FOR UPR MI. SINCE OTHER MODELS
ARE MORE AGGRESSIVE WITH RETURNING MSTR...TENDED TOWARD THE LO END
OF GUIDANCE/ECMWF FCST TEMPS FOR SAT NGT...WHICH COULD BE QUITE
CHILLY WITH MIN TEMPS FALLING TOWARD THE LO 20S.
EXTENDED...AS THE CLOSED LO/ACCOMPANYING SFC LO/LARGER SCALE CYC
FLOW TO THE SW SLOWLY MOVE NEWD...MAINTAINED GRADUAL INCRS IN POPS
SHOWN BY MODEL CONSENSUS IN THE MON THRU WED TIME. TIGHTENING PRES
GRADIENT BTWN THE SLOWLY RETREATING HUDSON BAY HI PRES AND APRCHG
DEEP LO PRES WL RESULT IN STEADY/GUSTY E WINDS. FCST THERMAL FIELDS
THAT SUPPORT WELL BLO NORMAL TEMPS ALSO INDICATE SOME OF THE PCPN
MAY BE AT LEAST MIXED WITH SN AT TIMES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 AM EDT THU APR 24 2014
AS THE HIGH PRESSURE RIDGE OVER LAKE HURON EARLY THIS MORNING DRIFTS
OFF THE EAST COAST FRIDAY MORNING...A LOW OVER THE CENTRAL PLAINS
WILL SHIFT TO THE LOWER GREAT LAKES. SE GUSTS WILL NEAR 30-35KTS
LATE THIS EVENING OVER MAINLY CENTRAL LAKE SUPERIOR. THE LOW WILL
CONTINUE NE INTO NEW ENGLAND ON SATURDAY. A LARGE CANADIAN HIGH
PRESSURE RIDGE WILL THEN BUILD ACROSS THE UPPER GREAT LAKES SATURDAY
INTO MONDAY. ANOTHER ROUND OF STRONGER E WINDS NEARING 25-30KTS WILL
BE POSSIBLE MONDAY...IN BETWEEN THE EXITING RIDGE OF HIGH PRESSURE
AND NEARING LOW PRESSURE FROM THE PLAINS STATES.
&&
.HYDROLOGY...
ISSUED AT 417 AM EDT THU APR 24 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO FLOW
THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL RUNNING
HIGH AND EVEN RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAT
WERE SEEN RECENTLY. LOCATIONS THAT STILL ARE STILL NEAR OR ABOVE
BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL AND
THE PAINT RIVER NEAR CRYSTAL FALLS. WHILE THE PAINT RIVER NEAR
CRYSTAL FALLS IS NOT EXPECTED TO REACH FLOOD STAGE IN THE SHORT
TERM...THE STURGEON RIVER NEAR CHASSELL WILL BE CLOSE AND WILL
CONTINUE TO BE MONITORED.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
MORE PRECIPITATION WILL RETURN TODAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...RJT
MARINE...KF
HYDROLOGY...KC/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
351 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 503 PM EDT WED APR 23 2014
WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE
THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH
THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES.
SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS
FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE
OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY
EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW
CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS
IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER.
TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET
THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE
THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE
WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY
INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF
IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW
ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT
18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT
THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING
OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO
SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH...
REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z
RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF
WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE
IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z
MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS
INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE
CWA...INCLUDING THE KEWEENAW PENINSULA.
DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY
AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR
CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET
STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO
NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO
H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH
290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE
INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH
MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG
ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY
TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA
PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF
MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT
COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR
THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP
HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING
RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE
TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING
AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME
PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND
GEM-NH.
PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND
MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE
CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE
NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE
SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW.
FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR
HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL
TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY
SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE
MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE
INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW
INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY
EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT
IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL
SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF
ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS
WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR.
EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED
6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8
TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z
MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE
GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN
ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS
EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY
MORNING.
IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS
FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING
MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY
OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER
STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND
DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED.
SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING
INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST.
SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY
EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85
THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE
FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE
BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON
SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH
KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS
HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF
THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES
BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS
WEEKEND.
REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY
AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN
THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY
OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP
CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT
WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY
MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE
FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE
ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX
TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE
FORECAST ELEMENTS INCLUDING POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 AM EDT THU APR 24 2014
AS THE HIGH PRESSURE RIDGE OVER LAKE HURON EARLY THIS MORNING DRIFTS
OFF THE EAST COAST FRIDAY MORNING...A LOW OVER THE CENTRAL PLAINS
WILL SHIFT TO THE LOWER GREAT LAKES. SE GUSTS WILL NEAR 30-35KTS
LATE THIS EVENING OVER MAINLY CENTRAL LAKE SUPERIOR. THE LOW WILL
CONTINUE NE INTO NEW ENGLAND ON SATURDAY. A LARGE CANADIAN HIGH
PRESSURE RIDGE WILL THEN BUILD ACROSS THE UPPER GREAT LAKES SATURDAY
INTO MONDAY. ANOTHER ROUND OF STRONGER E WINDS NEARING 25-30KTS WILL
BE POSSIBLE MONDAY...IN BETWEEN THE EXITING RIDGE OF HIGH PRESSURE
AND NEARING LOW PRESSURE FROM THE PLAINS STATES.
&&
.HYDROLOGY...
ISSUED AT 503 PM EDT WED APR 23 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO
FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL
RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN
RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME
INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR
CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD
STAGE IN THE SHORT TERM.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...KF
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1206 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 503 PM EDT WED APR 23 2014
WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE
THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH
THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES.
SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS
FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE
OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY
EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW
CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS
IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER.
TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET
THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE
THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE
WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY
INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF
IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW
ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT
18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT
THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING
OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO
SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH...
REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z
RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF
WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE
IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z
MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS
INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE
CWA...INCLUDING THE KEWEENAW PENINSULA.
DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY
AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR
CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET
STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO
NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO
H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH
290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE
INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH
MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG
ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY
TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA
PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF
MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT
COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR
THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP
HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING
RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE
TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING
AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME
PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND
GEM-NH.
PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND
MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE
CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE
NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE
SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW.
FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR
HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL
TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY
SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE
MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE
INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW
INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY
EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT
IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL
SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF
ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS
WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR.
EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED
6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8
TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z
MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE
GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN
ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS
EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY
MORNING.
IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS
FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING
MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY
OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER
STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND
DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED.
SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING
INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST.
SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY
EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85
THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE
FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE
BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON
SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH
KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS
HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF
THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES
BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS
WEEKEND.
REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY
AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN
THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY
OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP
CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT
WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY
MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE
FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE
ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX
TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE
FORECAST ELEMENTS INCLUDING POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 PM EDT WED APR 23 2014
LOW PRESSURE MOVES INTO THE REGION THURSDAY NIGHT INTO FRIDAY. LOW
IS TRENDING STRONGER...SO EAST WINDS MAY REACH 30 KTS THURSDAY NIGHT
THEN SHIFT TO THE NORTH-NORTHWEST UP TO 30 KTS BY FRIDAY AFTN AFTER
THE LOW MOVES TO THE EAST OF LK SUPERIOR. POSSIBLE THAT SOME GALE
GUSTS TO 35 KTS MAY OCCUR LATE FRIDAY AFTN INTO FRIDAY EVENING.
WINDS DIMINISH BLO 20 KTS FOR THE WEEKEND AS HIGH PRESSURE SETTLES
ACROSS ONTARIO AND THE GREAT LAKES. NEXT CHANCE OF STRONGER EAST
WINDS WOULD BE ON MONDAY AS THE HIGH SLOWLY MOVES EAST AND LOW
PRESSURE DEVELOPS OVER THE PLAINS.
&&
.HYDROLOGY...
ISSUED AT 503 PM EDT WED APR 23 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO
FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL
RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN
RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME
INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR
CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD
STAGE IN THE SHORT TERM.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY AFTERNOON
FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
403 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1155 PM CDT Wed Apr 23 2014
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and now have marginal LLWS conditions
at all TAF sites. Precipitation timing is still a tough call on
Thursday, but overall the trend and timing is slower than previous
forecasts. Expecting shra and possibly a few rumbles of thunder to
impact KCOU-KUIN in the 16-18z time frame with this activity
weakening as it moves east. Better potential for organized showers
and thunderstorms at all TAFS sites will be on Thursday afternoon/evening
along and ahead of a cold front where I have conditions lowering
to MVFR.
Specifics for KSTL:
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and local radar VWPs suggest marginal LLWS
conditions through 14-15z. Best potential for organized showers
and thunderstorms at KSTL will be between 22-02z on Thursday
afternoon/evening along and ahead of a cold front where I have
conditions lowering to MVFR.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
330 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 329 PM CDT Wed Apr 23 2014
(Thursday through Saturday)
Main focus for Thurs will be precip chances. Not much change from
the prev forecast other than slowing timing down a bit. Some
questions remain regarding exactly how precip on Thurs will play
out. Believe that the morning hours will be similar to what is
occurring now. Expect precip to intensify during the afternoon and
into the evening along and just ahead of the cdfnt, if enuf heating
can occur. Am becoming more concerned of an isod TSRA becoming
strong to severe, mainly across portions of central MO. However,
this is highly conditional on the amount of heating that can occur
during the day. Will therefore not mention for now and allow the
night shift to reevaluate.
Beyond Thurs, the remainder of the period shud be dry. Did keep low
chance POPs for Sat as a wrmfnt lifts thru the region due to
uncertainty. However, with height rises over the area and better
forcing across KS and wrn MO, believe bulk of precip will remain W
of the CWA.
The focus quickly turns to temps for Fri and Sat. Differences among
mdls leads to a lot of uncertainty for these days. Given the past
couple of warm up events, will trend twd the GFS/local WRF solns.
These solns strong SW to W flow at the sfc with the thermal ridge
pushing into the region. This, coupled with deep mixing, shud allow
temps to reach the 80s for Fri. Sat shud be a little cooler as a
weak cdfnt drops swd across the region, but still a warm day.
(Sunday through Wednesday)
While specifics may differ among mdl solns, general trends are in
fairly good agreement thru the extd period. Mdls suggest an initial
surge of TSRA will push thru the region on Sun thru Mon as a large
low system approaches the area. This system has a threat of severe
weather for much of the CWA. As this system is still 5 plus days
out, time will not be spent discussing details that are likely to
change many times by the end of this weekend.
By Mon night, a S/W associated with the upper low progd to be over
the nrn Atlantic, will approach the upper low over the MO region.
After a brief Fujiwhara interaction, these two low centers are progd
to combine forming one large low system. Mdls differ regarding
placement of this interaction, which will be vital to determining
where precip will occur associated with this low. If the interaction
is further E, the low shud eject precip ewd out of the region, per
the GFS soln. If it is further W, per the ECMWF, precip shud linger
for at least a while.
Regardless, both solns suggest much colder temps will remain locked
in place thru the remainder of next week. Will take a closer look at
temps for Wed and beyond tomorrow, but going forecast of mid 50s may
have too much of an influence on climo and need to be lowered with
future updates.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1155 PM CDT Wed Apr 23 2014
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and now have marginal LLWS conditions
at all TAF sites. Precipitation timing is still a tough call on
Thursday, but overall the trend and timing is slower than previous
forecasts. Expecting shra and possibly a few rumbles of thunder to
impact KCOU-KUIN in the 16-18z time frame with this activity
weakening as it moves east. Better potential for organized showers
and thunderstorms at all TAFS sites will be on Thursday afternoon/evening
along and ahead of a cold front where I have conditions lowering
to MVFR.
Specifics for KSTL:
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and local radar VWPs suggest marginal LLWS
conditions through 14-15z. Best potential for organized showers
and thunderstorms at KSTL will be between 22-02z on Thursday
afternoon/evening along and ahead of a cold front where I have
conditions lowering to MVFR.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
THERE IS A COLD FRONT MOVING THROUGH THE CWA. THE LATEST RAPID
REFRESH GUIDANCE SHOWS IT SLOWING SOME OVERNIGHT AS THE NEXT WAVE
OF LOW PRESSURE DEVELOPING OVER SRN NEBRASKA LIFTS NEWD ALONG THE
FRONT. THE RAPID REFRESH MODEL ALSO SUGGESTS PRECIPITATION WITH
THIS NEXT WAVE SHOULD LIFT UP TOWARD THE REGION TOWARD 12Z
FRIDAY...AND LIKELY MISS MOST OF THE FAR EASTERN ZONES WITH ANY
ADDITIONAL PRECIPITATION.
WHILE SKIES PARTIALLY CLEAR AND WINDS RELAX WITHIN/NEAR THE
SLOWING SURFACE TROF...WENT AHEAD AND TOSSED IN SOME AREAS OF FOG
MENTION TO COVER ANY SURFACE MOISTURE LEFT OVER FROM THE PERIODS
OF LIGHT RAIN EARLIER IN THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
COLD FRONT IS SLOWLY WORKING ITS WAY EAST ACROSS WESTERN SD AND IS
APPROACHING THE WESTERN FRINGE OF THE CWA. AHEAD OF THE
FRONT...STRONG SOUTHEAST WINDS CONTINUE...WELL INTO ADVISORY
LEVELS FOR MANY LOCATIONS. ALTHOUGH...AS PRESSURE GRADIENT RELAXES
A BIT WITH THE APPROACH OF THE SFC TROUGH...WE ARE SEEING A SUBTLE
AND SLOW DROP OFF IN SPEEDS OUT OF CRITERIA LEVELS FROM WEST TO
EAST. WILL LET THE JAMES VALLEY PORTION OF THE WIND ADVISORY
EXPIRE AT 21Z WITH THE REMAINING EASTERN AREA GOING UNTIL 00Z.
ASIDE FROM THE WIND...ALSO DEALING WITH SCT SHOWERS AHEAD OF THE
FRONT. AS WAS SUGGESTED BY THE HRRR AND OTHER HI RES MODELS...WE
ARE SEEING A BIT OF REDEVELOPMENT ALONG AND EAST OF THE MISSOURI
RIVER. SO...EXPECTING DECENT CHANCES FOR PRECIP YET THIS AFTERNOON
AND INTO THE EVENING HOURS BEFORE COLD FRONT SCOURS OUT MOST OF
THE AVAILABLE MOISTURE.
NEXT AREA OF CONCERN IS THE CRITICAL FIRE DANGER ON THURSDAY.
BEHIND THE COLD FRONT...DRY AIR MOVES BACK INTO THE REGION ALONG
WITH BREEZY NORTHWEST WINDS GUSTING OVER 30 MPH. MIN RH VALUES ARE
EXPECTED TO FALL CLOSE TO 20 PERCENT IN THE JAMES VALLEY WITH
VALUES LIKELY GOING BELOW 20 PERCENT ACROSS CENTRAL/SOUTH CENTRAL
SD. HAVE THEREFORE UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG
WARNING EFFECTIVE FROM 18Z TO 00Z TOMORROW.
TEMPS STAY MILD THROUGH THE SHORT TERM...AND THERE HAS BEEN AN
UPWARD TREND IN TEMPS ON FRIDAY. GFS IS STILL STUBBORN IN BRINGING
COOLER TEMPS AT 850 MB INTO THE NORTHERN/EASTERN CWA DURING THE
DAY FRIDAY...SHOWING A BIT MORE INFLUENCE OF THE COOLER HIGH TO THE
NORTH. THIS REALLY IS NOT SUPPORTED BY OTHER MODELS THOUGH SO HAVE
GONE WITH THE WARMER SOLUTIONS SEEN IN THE EC AND GEM.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
THE MODELS SHOW GOOD AGREEMENT IN THE LONG TERM WITH A MAINLY WET
AND COOL PATTERN FROM SATURDAY THROUGH MONDAY NIGHT. THE MODELS
SHOW A SURFACE LOW PRESSURE AREA INTENSIFYING IN EASTERN COLORADO
THROUGH SATURDAY AFTERNOON. THIS SURFACE LOW PRESSURE AREA THEN
WOBBLES AND MOVES SLOWLY EAST AND SOUTHEAST ACROSS THE CENTRAL
PLAINS THROUGH MONDAY NIGHT. DEEP AND MOIST EAST TO SOUTHEAST FLOW
NORTH OF THE LOW PRESSURE AREA WILL BRING MAINLY RAIN TO MUCH OF
OUR CWA STARTING SATURDAY AFTERNOON. THE CHANCES OF RAIN CONTINUE
TO BE GOOD THROUGH MONDAY NIGHT. IT LOOKS LIKE MUCH OF THE CWA
WILL GET SOME DECENT RAINFALL ACCUMULATIONS WITH THIS SYSTEM.
OTHERWISE...THE SYSTEM WILL SLOWLY PUSH OUT FOR TUESDAY AND
WEDNESDAY WITH COOL CANADIAN SURFACE HIGH PRESSURE BUILDING IN.
WITH THE RAIN...CLOUDS AND CANADIAN AIR TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE ENTIRE LONG TERM. HIGHS WILL BE MOSTLY
IN THE 40S AND 50S THROUGH THE PERIOD.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PRECIPITATION CHANCES ARE BASICALLY DONE AT KPIR/KMBG AND KABR.
HOWEVER...LATER TONIGHT INTO EARLY THURSDAY MORNING...ANOTHER
PIECE OF LOW PRESSURE ENERGY COULD POTENTIALLY GENERATE SOME LIGHT
PRECIPITATION AT THE KATY TERMINAL.
MEANWHILE...WEST OF THE COLD FRONT /KPIR AND KMBG/ THAT IS SLOWING
DOWN RIGHT NOW...VFR CONDITIONS SHOULD PREVAIL OVER THE NEXT 24
HOURS. EAST OF THE COLD FRONT KABR AND KATY...BUT ESPECIALLY
KATY...COULD SEE VFR CONDITIONS DETERIORATE INTO MVFR AND POSSIBLY
IFR STRATUS AND FOG MAINLY BETWEEN 09Z AND 15Z THURSDAY.
EVENTUALLY...THE COLD FRONT WILL PUSH EAST OF KABR AND KATY DRYING
THINGS OUT AS BREEZY WEST-NORTHWEST WINDS DEVELOP.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR LOWER BAD RIVER-MISSOURI
COTEAU-UPPER CHEYENNE-UPPER JAMES RIVER-UPPER MISSOURI
COTEAU.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1156 PM CDT WED APR 23 2014
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
MOISTURE ADVECTION WILL CONTINUE OVERNIGHT TONIGHT AND THURSDAY
MORNING. MODEL SOUNDINGS FORECAST AN IFR DECK FORMING BY AROUND
09Z AND LIFTING AROUND OR SHORTLY AFTER 15Z...ALTHOUGH THE
CEILINGS MAY BE SLOWER TO LIFT AND SCATTER OUT LATER IN THE
MORNING. BEST CHANCES FOR ISOLATED THUNDERSTORMS STILL LOOK TO BE
AT KCLL AND KUTS BETWEEN 21Z AND 03Z. THE MODELS ARE SHOWING A
WIND SHIFT MOVING INTO SE TX THURSDAY EVENING. MVFR FOG CONDITIONS
ARE POSSIBLE AHEAD OF THE WIND SHIFT BY LATE THURSDAY EVENING.
40
&&
.PREV DISCUSSION... /ISSUED 909 PM CDT WED APR 23 2014/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
NOT MANY CHANGES PLANNED FOR THE EVENING UPDATE. AT 01Z...A DEEP
SURFACE LOW PRESSURE SYSTEM WAS LOCATED OVER WESTERN KANSAS WITH A
WEAK TROUGH AXIS EXTENDING S-SW. THE PRESSURE GRADIENT IS FAIRLY
TIGHT SO NOT EXPECTING WINDS TO DECOUPLE OVERNIGHT. WINDS JUST OFF
THE SURFACE ARE ALSO ROBUST SO FEEL FOG THREAT IS LESS THAN LAST
NIGHT. STORMS ARE FIRING ALONG THE SFC TROUGH AND THESE STORMS
WILL STAY WEST OF THE REGION BUT THEY WILL SEND A THICK CIRRUS
SHIELD THIS WAY. LOW CLOUDS WILL ALSO BE ON THE INCREASE OVERNIGHT
SO BETWEEN THE TWO CLOUD DECKS...FEEL THERMAL INSULATION WILL
KEEP MIN TEMPS A LITTLE WARMER THAN LAST COUPLE OF NIGHTS. TWEAKED
MIN TEMP GRIDS A BIT.
ON THURSDAY...A WEAK S/WV WILL MOVE EAST ACROSS NORTH TEXAS. FCST
SOUNDINGS SUGGEST A STRONG CAPPING INVERSION WILL REMAIN IN PLACE.
THE TEXAS TECH 3 KM WRF AND THE RAP DEVELOP SOME CONVECTION OVER
CENTRAL TEXAS AND MOVE THIS AREA ACROSS SE TX AROUND 18Z. THE
ECMWF IS QUITE BULLISH WITH POPS OVER THE NE PART OF THE AREA
DURING THE AFTN. THE ECMWF HAS THE BEST JET DYNAMICS AS WELL WITH
A SPLITTING JET AND A RRQ. 00Z NAM12 STILL KEEPING THE AREA CAPPED
ON THURSDAY. THINK THE CURRENT FCST WITH 20 POPS OVER THE NORTH
IS STILL VALID. NEW ZONES OUT BY 915 PM. 43
PREV DISCUSSION... /ISSUED 626 PM CDT WED APR 23 2014/
DISCUSSION...
GOOD MOISTURE ADVECTION COUPLED WITH A TIGHT PRESSURE GRADIENT AND
A LOW-LEVEL INVERSION WILL LEAD TO THE WINDS STAYING UP AND AN IFR
LAYER FORMING TONIGHT. THE TIME PERIOD FORECASTED BY THE MODELS
FOR IFR WAS BETWEEN 09Z AND 14Z...ALTHOUGH THE MOISTURE LAYER WILL
BE FAIRLY SHALLOW. THE INVERSION SHOULD BREAK AND ALLOW FOR MIXING
TO SCATTER OUT THE CLOUD DECK MID MORNING THURSDAY. LIKED THE GFS
IN BRINGING IN CHANCES FOR ISOLATED THUNDERSTORMS TO KCXO...
KCLL...AND KUTS THURSDAY AFTERNOON. FOR NOW WENT WITH A VCTS
MENTION AT ALL THREE SITES.
40
PREV DISCUSSION... /ISSUED 349 PM CDT WED APR 23 2014/
DISCUSSION...
WARM AFTERNOON ACROSS THE REGION TODAY (83-88 INLAND) WITH MOIST
S-SE FLOW IN PLACE. UPPER RIDGING OVER THE AREA THIS MORNING WILL
CONTINUE TO SLIDE EAST TONIGHT WITH A LARGE UPPER TROUGH OVER THE
WESTERN HALF OF THE COUNTRY. THIS UPPER TROUGH WILL LIFT NORTHEAST
INTO THE PLAINS AND S/W ENERGY ROTATES UP OVER THE RED RIVER WHICH
WILL PROBABLY BE TOO FAR NORTH FOR SETX TO MUCH IN THE WAY OF
RAINFALL EXCEPT PERHAPS THE FAR NORTH THURSDAY. THE ASSOCIATED
MILD PACIFIC COLD FRONT SWINGS INTO THE NORTHERN CWA LATE THURSDAY
AND STALLS WITH A GOOD CAP IN PLACE. WHICH SHOULD BRING SOME DRIER
AIR ALBEIT BRIEFLY BEFORE SE TO SOUTH FLOW INCREASES.
THIS MOIST FLOW WILL LIKELY LEAD TO A ROUND OF WIDESPREAD STRATUS
AND POSSIBLY SOME PATCHY FOG TONIGHT AND AGAIN FRIDAY WITH FOG
THREAT A LITTLE GREATER FRIDAY WITH DRIER AIR IN THE NORTH AND
NOTICEABLE DEWPOINT GRADIENT ACROSS THE AREA WITH GREATER
RADIATIONAL COOLING POTENTIAL.
SATURDAY WARM AND MOIST AND AS NEXT TROUGH MOVES INTO NM SUNDAY
MORNING RAIN CHANCES INCREASE WITH LLJ OVERHEAD AND NEARLY
SPLITTING UPPER JET BUT MAY BE TOO CAPPED. BY MONDAY MORNING THE
PACIFIC FRONT IS PUSHING EAST INTO THE REGION AND INCREASING PVA
AND SLIGHTLY MORE FAVORABLE UPPER JET MAY GIVE THE AREA THE BEST
CHANCE OF RAIN BUT FOR NOW WILL KEEP IT AT 30 NORTH EARLY THEN
TAPERING DOWN TO 20S BY AFTERNOON. STILL PLENTY OF TIME FOR MODELS
TO FLIP FLOP ON TIMING AND TRACK OF THE UPPER LOW (WHICH MAY BE
FURTHER NORTH). DRY AIR WRAPS AROUND AS FRONT PUSHES THROUGH
TUESDAY AND SLIGHTLY COOLER WEATHER (AROUND NORMAL TO JUST
SLIGHTLY BELOW NORMAL) SHOULD PREVAIL WED/THU/FRI.
45
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THROUGH THE END OF
THE WEEK. WINDS AND SEAS WILL BEGIN TO BUILD THIS WEEKEND AS THE
PRESSURE GRADIENT TIGHTENS ACROSS THE STATE. CAUTION FLAGS ARE
POSSIBLE AS EARLY AS SATURDAY AFTERNOON WITH ADVISORY CONDITIONS
LIKELY BY SUNDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 85 65 85 66 / 20 20 10 10 10
HOUSTON (IAH) 65 84 66 84 67 / 10 10 10 10 10
GALVESTON (GLS) 69 76 68 78 69 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
626 AM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT OFF THE COAST TODAY THROUGH FRIDAY.
A WEAK COLD FRONT COULD DRIFT IN FROM THE NORTH THIS WEEKEND
BEFORE HIGH PRESSURE BUILDS OVER THE AREA THROUGH EARLY NEXT WEEK.
A STRONGER COLD FRONT WILL CROSS THE REGION NEXT TUESDAY OR
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
24/06Z GUIDANCE INCLUDING THE 09Z RAP HAVE TRENDED WARMER WITH HIGHS
THIS AFTERNOON ACROSS INTERIOR SOUTHEAST GEORGIA. WILL EXPAND THE
AREA OF MID-80S TO MATCH THIS. NO OTHER MAJOR CHANGES WILL BE
MADE.
AN UPPER LEVEL RIDGE AXIS WILL PASS OVERHEAD THIS AFTERNOON AS
SURFACE HIGH PRESSURE SHIFTS OFF THE COAST. THE SYNOPTIC FLOW WILL
BECOME SOUTHEAST THIS AFTERNOON AND EVENTUALLY TO THE SOUTH
TONIGHT AS THE HIGH SHIFTS FARTHER OFFSHORE AND A COLD FRONT
APPROACHES FROM THE WEST. LOW-LEVEL MOISTURE RETURN WILL GENERALLY
REMAIN FOCUSED ACROSS NORTHERN FLORIDA AND FAR SOUTHERN GEORGIA
THROUGH MUCH OF THE DAY...ALTHOUGH MIXING RATIOS WILL BEGIN TO
INCREASE ACROSS THE FAR SOUTHERN ZONES LATE. A ROBUST SEA BREEZE
CIRCULATION WILL DEVELOP EARLY THIS AFTERNOON ALONG THE BEACHES
AND MOVE STEADILY INLAND...AIDED BY THE INCREASED SOUTHEASTERLY
FLOW. THERE MAY BE JUST ENOUGH LOW-LEVEL MOISTURE FLUX CONVERGENCE
TO SUPPORT AN ISOLATED SHOWER OR TO ACROSS INTERIOR SOUTHEAST
GEORGIA...MAINLY SOUTH OF I-16...BUT PROBABILITIES LOOK TOO LOW TO
MENTION SLIGHT CHANCE POPS ATTM. HIGHS WILL RANGE FROM THE UPPER
70S/NEAR 80 ACROSS THE CHARLESTON TRI-COUNTY AREA TO THE LOWER-MID
80S ACROSS ELSEWHERE...WARMEST FAR INTERIOR SOUTHEAST GEORGIA.
BEACH LOCATIONS WILL REMAIN CONSIDERABLY COOLER WITH THE SHELF
WATERS STILL RATHER COOL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RETURN FLOW WILL BE IN FULL SWING AS A COLD FRONT
APPROACHES FROM THE WEST AND HIGH PRESSURE SLIPS FARTHER OFFSHORE.
MODELS SHOW SOME WEAK ISENTROPIC ASSENT DEVELOPING FROM SOUTH-
NORTH AS THE NIGHT PROGRESSES...BUT NONE OF THE VARIOUS MEMBERS
ARE OVERLY AGGRESSIVE IN THE DEVELOPMENT OF NOCTURNAL SHOWER
ACTIVITY AS MOST OF THE LIFT WILL GO TOWARDS CLOUD FORMATION GIVEN
THE HIGH CONDENSATION PRESSURE DEFICITS. WILL KEEP THE FORECAST
DRY WITH THE EXCEPTION OF THE CHARLESTON COUNTY COAST WHERE SOME
MARINE BASED CONVECTION COULD BRUSH AREAS FROM ROUGHLY FOLLY BEACH
TO MCCLELLANVILLE VERY EARLY THURSDAY. IT WILL BE A WARM NIGHT
WITH NOCTURNAL JETTING LIKELY KEEPING THE BOUNDARY LAYER FROM
FULLY DECOUPLING. LOWS WILL RANGE FROM THE UPPER 50S FAR INTERIOR
SOUTHEAST SOUTH CAROLINA TO THE LOWER-MID 60S ELSEWHERE. THIS IS
SLIGHTLY ABOVE THE 00Z GUIDANCE CONSENSUS.
FRIDAY...WE SHOULD SEE A FAIR AMOUNT OF CLOUDS TO START OFF THE DAY
AS MODEST ISENTROPIC ASCENT OCCURS AHEAD OF AN EASTWARD ADVANCING H5
SHORTWAVE JUST TO OUR NORTH. WE COULD SEE A FEW SHOWERS DURING
MORNING HOURS AS A RESULT...MAINLY ALONG THE COAST IN SOUTHEAST
SOUTH CAROLINA. A SLIGHT CHANCE OF SHOWERS AND/OR THUNDERSTORMS WILL
THEN BE POSSIBLE BY FRIDAY AFTERNOON AS INSTABILITY INCREASES DURING
PEAK HEATING WITH SBCAPES APPROACHING 700-1200 J/KG AND LIFTED INDEX
VALUES BETWEEN -1 TO -3C. THUNDERSTORM CHANCES APPEAR HIGHEST OVER
INLAND AREAS IN SOUTHEAST SOUTH CAROLINA WHERE FORCING FROM THE H5
SHORTWAVE AND A ARRIVING COLD FRONT ARE GREATEST. ALTHOUGH A CAPPING
INVERSION WILL SUPPRESS MOST DEEP CONVECTION...WE CAN NOT RULE OUT A
STRONGER THUNDERSTORM OR TWO BY FRIDAY EVENING. ACTIVITY WILL LIKELY
DIMINISH WITH COLD FROPA AND DIURNAL HEAT LOSS EARLY FRIDAY NIGHT.
1000-850 MB THICKNESS VALUES ALONG WITH SOME COMPRESSIONAL HEATING
SUPPORT OVERALL HIGH TEMPS IN THE LOW/MID 80S AWAY FROM THE COAST.
OVERNIGHT LOWS WILL RANGE IN UPPER 50S INLAND TO LOWER 60S ALONG THE
COAST BEHIND THE FRONT.
SATURDAY...HIGH PRESSURE WILL HOLD OVER THE AREA UNDER A BUILDING
RIDGE ALOFT. A DOWNSLOPING WIND COMPONENT WILL LIKELY SUPPORT ANOTHER
DAY OF WARM TEMPS WITH AFTERNOON HIGHS IN THE MID 80S OVER MOST
LOCATIONS AWAY FROM THE IMMEDIATE COAST. A WEAK AND DRY COLD FRONT
SHOULD STALL OR DISSIPATE NORTH OF THE FORECAST AREA SATURDAY
NIGHT...WITH LITTLE TO NO INFLUENCE OVER THE SOUTHEAST. THUS A
RAIN-FREE DAY IS EXPECTED. STRONG RADIATIONAL COOLING WILL ALLOW
OVERNIGHT TEMPS TO REACH THE UPPER 50S INLAND TO LOWER 60S ALONG THE
COAST.
SUNDAY...CONDITIONS LOOK FAIRLY DRY TO START OFF THE WEEK AS
ATLANTIC HIGH PRESSURE LINGERS OVER THE AREA WELL AHEAD OF A STRONG
LOW PRESSURE SYSTEM TRACKING EAST OVER THE CENTRAL UNITED STATES.
LIGHT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING SHOULD RESULT IN
EVEN WARMER TEMPS THAN THE PREVIOUS DAY. LATEST 1000-850 MB
THICKNESSES FAVOR OVERALL HIGH TEMPS IN THE MID/UPPER 80S AWAY FROM
THE COAST...WARMEST IN SOUTHEAST GEORGIA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
LIGHT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING OVER THE SOUTHEAST
WILL LIKELY KEEP WARMER TEMPS OVER THE SOUTHEAST INTO EARLY NEXT
WEEK AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM. IN GENERAL...HIGH
TEMPS WILL BE IN THE LOW/MID 80S MONDAY AND TUESDAY BEFORE COOLING A
FEW DEGREES ON WEDNESDAY AS CLOUD COVER INCREASES WITH THE LOW
PRESSURE SYSTEM SHIFTING OVER THE EASTERN CONUS. A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST ON MONDAY AS
SOUTHERLY FLOW DEEPENS MOISTURE OVER THE AREA WHILE AN H5 SHORTWAVE
PASSES OVERHEAD. PRECIP CHANCES SHOULD THEN INCREASE TUESDAY AND
WEDNESDAY AHEAD OF AN EASTWARD MOVING COLD FRONT ASSOCIATED WITH THE
LOW PRESSURE SYSTEM. THERE ARE INDICATIONS THAT WE COULD SEE AN
ENHANCED PERIOD OF SHOWERS AND/OR THUNDERSTORMS LATE TUESDAY INTO
WEDNESDAY AS STRONGER INSTABILITY AND WIND FIELDS SET UP OVER THE
SOUTHEAST AHEAD OF THE FRONT. A FEW THUNDERSTORMS COULD BE
STRONG...ESPECIALLY ON WEDNESDAY DURING PEAK HEATING. SHOWERS AND/OR
THUNDERSTORMS COULD PERSIST INTO MUCH OF THURSDAY AS THE COLD FRONT
SHIFTS OFFSHORE EARLY WHILE THE LARGE MID/UPPER LVL TROUGH REMAINS
POSITIONED OVER THE EASTERN CONUS. OVERALL TEMPS SHOULD COOL OFF
POST FROPA...WITH HIGHS ONLY IN THE MID/UPPER 70S ON THURSDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR...ALTHOUGH THE RISK FOR SUB-VFR CIGS WILL INCREASE AT KSAV
TOWARDS THE END OF THE 12Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS LATE
MONDAY AND TUESDAY WITH SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
TODAY...EAST TO NORTHEAST WINDS WILL GRADUALLY VEER MORE SOUTHERLY
THIS AFTERNOON AS HIGH PRESSURE SHIFTS OFF THE COAST AND A ROBUST
SEA BREEZE CIRCULATION TAKES HOLD. WINDS WILL GENERALLY BE 10-15
KT WITH SEAS 1-3 FT.
TONIGHT...SOUTHERLY WINDS WILL DOMINATE AS HIGH PRESSURE SHIFTS
EVEN FARTHER OFFSHORE WINDS. WINDS WILL BE 10-15 KT WITH SEAS 2-3
FT.
FRIDAY THROUGH TUESDAY...A WEAK COLD FRONT WILL QUICKLY ADVANCE OVER
THE WATERS FRIDAY NIGHT...LEADING TO A MARGINAL SURGE OF WINDS
BETWEEN 15-20 KTS LATE. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS SATURDAY AND PERSIST INTO EARLY NEXT WEEK AHEAD OF A LOW
PRESSURE SYSTEM ADVANCING TO THE EASTERN CONUS. WINDS/SEAS ARE
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH EARLY
TUESDAY...BUT SHOULD APPROACH SMALL CRAFT ADVISORY LEVELS BY TUESDAY
NIGHT AS THE PRESSURE GRADIENT ENHANCES AHEAD OF A COLD FRONT
ADVANCING TO THE SOUTHEASTERN UNITED STATES BY MIDWEEK. IN
GENERAL...SOUTH/SOUTHEAST WINDS WILL REMAIN AT OR BELOW 15 KTS
THROUGH EARLY TUESDAY WHILE SEAS ARE NO HIGHER THAN 3-4 FT. BY
TUESDAY NIGHT...WINDS/SEAS SHOULD INCREASE/BUILD TO 20-25 KTS AND
4-6 FT...HIGHEST BEYOND 10 NM FROM THE COAST.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/DPB
Area Forecast Discussion
National Weather Service Lincoln IL
1046 AM CDT Thu Apr 24 2014
.DISCUSSION...
ISSUED 1046 AM CDT Thu Apr 24 2014
Area of low pressure currently located near Kansas City will track
slowly E/NE into west-central Illinois by this evening. While
showers and thunderstorms are prevalent ahead of this feature
across central and western Missouri, the airmass further east over
Illinois remains rather dry. 15z/10am surface dewpoints are only
in the middle to upper 30s, while the 12z KILX upper air sounding
showed a large amount of dry air below 700mb. With a southeasterly
low-level flow ahead of the system, am not expecting much moisture
advection before the low and its associated front arrive. High-res
models such as the HRRR and the NAM12 are suggesting that the
eastward progression of the precip will be slower than previously
expected and this seems reasonable given the current conditions.
Have therefore trimmed POPs back today. Will keep the entire KILX
CWA dry through midday, then will slowly advance precip eastward
this afternoon. Will continue with a dry forecast east of the
I-57 corridor through the entire afternoon, with POPs gradually
ramping up to categorical further west across the Illinois River
Valley. Also made adjustments to sky cover to feature more
sunshine across the E/SE. Zone update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 625 AM CDT Thu Apr 24 2014
Several forecast concerns this period include surface wind gusts
later this morning into this afternoon and a deterioration in
cigs this evening as showers and scattered TSRA affect the TAF
sites. Band of showers was located over east central Iowa, tracking
mainly to the northeast and not expected to affect our TAF
locations this morning. However, as a frontal boundary out to our
west make progress to the east later today, the threat for showers
and storms will increase from west to east in the 20z-01z time
frame. Widespread rain and isold TSRA will be the story this
evening with the cigs gradually lowering to MVFR with some brief
IFR cigs possible where some of the heavier showers/storms move
through. Steadier light rains will follow later this evening
before the system shifts off to our east late tonight. Surface
winds will be out of the southeast at 15 to 25 kts today with
a few gusts around 30 kts at times. FROPA is not expected until
or just after 03z at PIA with CMI the last to see the wind shift
by 08z.
Smith
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Apr 24 2014
SHORT TERM...Today through Sunday
00Z models continue to be slower with cold frontal passage and
associated convection and that is the biggest change in the
forecast package. Most areas will be dry this morning with showers
and thunderstorms affecting areas from I-55 west this afternoon
and possibly getting as far east as I-57 late this afternoon. SPC
keeps slight risk of severe storms in southern IL south of our
CWA. Though there is a 5% risk of damaging wind gusts in far sw CWA
from Springfield to Lawrenceville south late this afternoon and
evening. Upper level trof over CO/NM with embedded short wave to
move into IL overnight while a cold front moves east across IL
during tonight. Have increased pops this evening due to slower
movement of front and then decreasing pops from west to east
behind cold front during overnight. Highs today in the upper 60s
nw over IL river valley to mid 70s se of I-70. Lows tonight 45-50F
over central IL and 50-55F in southeast IL. Rainfall amounts this
afternoon and tonight of a half to three quarter inch with locally
three quarter to 1 inch west of I-55.
Storm system to pass east of IL across IN/OH Friday morning with
more sunshine returning and mild highs in the low to mid 70s and
warmest over sw counties. Even a few degrees warmer on Saturday as
models have 850 mb temps of 12-14C. Still appears dry Friday
through the day on Saturday with partly to mostly sunny skies Sat.
Rather mild again on Sunday with highs in the upper 60s to mid 70s.
Models have trended warmer this weekend ahead of next storm system
over the Rockies. Continue chances of showers and isolated
thunderstorms Saturday night and Sunday as warm air advection
regime sets up again.
LONG TERM...Sunday night through Thursday
Extended models like GFS, ECMWF and GEM develop a strong/large cutoff
upper level low near CO Sunday morning and then move it into the MO
valley Tue and mid MS river valley during middle of next week.
This to bring an unsettled weather pattern with daily chance of
showers and isolated thunderstorms from Sunday through Thursday
with highest chances Sunday night through Tuesday. Mild temps
early in the week to cool by middle of next week as upper level
low moves near IL. Widespread rainfall amounts of 1-2 inches
expected during this time with heaviest amounts southern areas.
Seasonable highs in the upper 60s and lower 70s Monday cool into
the low to mid 50s Wed/Thu.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1036 AM CDT Thu Apr 24 2014
.UPDATE:
Issued at 1029 AM CDT Thu Apr 24 2014
Based on latest radar/satellite data...adjusted temperatures
upwards a few degrees across the eastern half of the CWA while
trimming highs over portions of central and northeastern Missouri
where pre-frontal cloudiness and shra with embedded thunder is
moving in late this morning.
For this afternoon...not sure how unstable we will
get...especially for the northern half to two-thirds of the CWFA.
Aforementioned pre-frontal clouds/precipitation could really hamper
instability from rising later on this afternoon. HRRR/RAP really
suffering from warming warm sector way too much as hourly
temperatures even over central Missouri per these near-term models
would climb into the upper 70s and low 80s.
Consequently...developing way too much sfc-based instability. In
addition...stronger shear this afternoon/evening will be over
southeastern Missouri just to south of area so not sure degree of
strong/severe storms this far north. Regardless...very strong
forcing for ascent via strong DCPVA and jet coupling aloft should
produce a widespread shield of rain with embedded thunderstorms
along the front. Will montior situation throughout today and make
additional adjustments/changes to the forecast as necessary.
Gosselin
&&
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 633 AM CDT Thu Apr 24 2014
Needless to say, a complex forecast for this period for area TAF
sites. Showers/thunderstorms currently ongoing over western
Missouri will continue to move ENE this morning, largely fueled by
warm advection and a strong southwesterly low level jet. The HRRR
has maintained a good handle on the evolution of the precipitation
overnight, thus have taken it into consideration regarding future
trends today. Thinking is for SHRA/TSRA from western Missouri to
impact KCOU by around 15Z-16Z and KUIN by 16Z-17Z. This
precipitation should remain northwest of metro TAF sites, thus
have not included precipitation mention for metro sites until late
this afternoon when SHRA/TSRA associated with the cold front are
expected to impact the area. Expect KCOU and KUIN to see a few
rounds of SHRA/TSRA this afternoon, prior to the passage of a cold
front through the terminals by around 00Z (KCOU) and 02Z (KUIN).
For metro TAF sites, expect SHRA/TSRA activity to increase by
ahead of the front, and continue until the front passes between
03Z-04Z, with lingering showers for perhaps another 2 hours
affecting area TAF sites.
Prior to the onset of precipitation, expect continued
gusty southerly/southeasterly winds and VFR flight conditions
along with increasing midlevel clouds. Flight conditions will
decrease to MVFR during SHRA/TSRA, and slowly improve late tonight
post- FROPA. Winds will quickly veer to the west in the wake of
the front, and remain between 10-15KT overnight.
Specifics for KSTL:
VFR flight conditions expected to prevail through the first part
of the forecast period. An area of showers and thunderstorms over
western Missouri continues to move ENE this morning, and is
expected to remain just northwest of the terminal given latest
HRRR guidance. Expect SHRA/TSRA activity to ramp up late this
afternoon ahead of an advancing cold front, and persist until the
front passes through the terminal around 03Z-04Z. Flight
conditions will decrease to MVFR in areas of precipitation, with
ceilings slowly improving overnight after SHRA has ended and
drier air begins to filter into the region in the wake of the cold
front. Winds will remain southerly/southeasterly today, gusting to
20-25KT, and veer quickly to the west behind the front tonight,
remaining between 12-15KT sustained. Clouds are expected to
scatter out by daybreak, providing VFR conditions through the end
of the period on Friday.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
654 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 633 AM CDT Thu Apr 24 2014
Needless to say, a complex forecast for this period for area TAF
sites. Showers/thunderstorms currently ongoing over western
Missouri will continue to move ENE this morning, largely fueled by
warm advection and a strong southwesterly low level jet. The HRRR
has maintained a good handle on the evolution of the precipitation
overnight, thus have taken it into consideration regarding future
trends today. Thinking is for SHRA/TSRA from western Missouri to
impact KCOU by around 15Z-16Z and KUIN by 16Z-17Z. This
precipitation should remain northwest of metro TAF sites, thus
have not included precipitation mention for metro sites until late
this afternoon when SHRA/TSRA associated with the cold front are
expected to impact the area. Expect KCOU and KUIN to see a few
rounds of SHRA/TSRA this afternoon, prior to the passage of a cold
front through the terminals by around 00Z (KCOU) and 02Z (KUIN).
For metro TAF sites, expect SHRA/TSRA activity to increase by
ahead of the front, and continue until the front passes between
03Z-04Z, with lingering showers for perhaps another 2 hours
affecting area TAF sites.
Prior to the onset of precipitation, expect continued
gusty southerly/southeasterly winds and VFR flight conditions
along with increasing midlevel clouds. Flight conditions will
decrease to MVFR during SHRA/TSRA, and slowly improve late tonight
post- FROPA. Winds will quickly veer to the west in the wake of
the front, and remain between 10-15KT overnight.
Specifics for KSTL:
VFR flight conditions expected to prevail through the first part
of the forecast period. An area of showers and thunderstorms over
western Missouri continues to move ENE this morning, and is
expected to remain just northwest of the terminal given latest
HRRR guidance. Expect SHRA/TSRA activity to ramp up late this
afternoon ahead of an advancing cold front, and persist until the
front passes through the terminal around 03Z-04Z. Flight
conditions will decrease to MVFR in areas of precipitation, with
ceilings slowly improving overnight after SHRA has ended and
drier air begins to filter into the region in the wake of the cold
front. Winds will remain southerly/southeasterly today, gusting to
20-25KT, and veer quickly to the west behind the front tonight,
remaining between 12-15KT sustained. Clouds are expected to
scatter out by daybreak, providing VFR conditions through the end
of the period on Friday.
JP
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
942 AM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 936 AM CDT THU APR 24 2014
UPDATED FORECAST FOR MAINLY FIRE WEATHER ELEMENTS. BASED ON RAPID
CITYS UPPER AIR SOUNDING AND THE LATEST RAP MODEL...LOWERED
RELATIVE HUMIDITIES ACROSS MUCH OF THE AREA FOR TODAY. THE WINDS
LOOK TO BE ON TRACK FOR THE RED FLAG WARNING ALSO. HOWEVER...WINDS
MAY DROP OFF BY LATE AFTERNOON. UPDATED OTHER FIRE WEATHER
ELEMENTS BASED ON LATEST MODEL DATA INCLUDING HAINES...MIXING
HEIGHT...TRANSPORT WINDS...AND VENTILATION RATE/SMOKE DISPERSAL.
PUBLIC FORECAST WAS LARGELY UNCHANGED WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
POST FRONTAL SHOWERS CONTINUE OVER A SMALL PORTION OF SOUTHWEST
NEBRASKA AND NORTH CENTRAL NEBRASKA EARLY THIS MORNING. LAST
LIGHTNING WAS AROUND 05Z. FAIRLY STRONG NORTHWEST FLOW CONTINUING
OVER THE FORECAST AREA EARLY THIS MORNING. ALL SHOWERS SHOULD HAVE
CLEARED FORECAST AREA BY 12Z. BIG WINNERS TONIGHT WERE GARFIELD
AND WHEELER COUNTIES WITH LESS THAN A QUARTER OF AN INCH. THIS
WILL HAVE IMPLICATIONS WITH FIRE WEATHER...SEE DISCUSSION BELOW.
MODELS IN FAIR AGREEMENT THIS MORNING FOR THE NEAR TERM.
TEMPERATURES ABOUT 10F DEGREES COOLER TODAY ACROSS THE FORECAST
AREA. STRONG NORTHWEST FLOW TO CONTINUE OVER THE AREA AGAIN TODAY
WITH GOOD MIXING AND SKIES CLEARING OUT FROM THE PANHANDLE
EASTWARD THROUGH THE MORNING. MODELS HAVE CLOUDS CLEARING OUT
PRETTY QUICKLY BUT CURRENT TRENDS ON SATELLITE NOT SUPPORTIVE OF
THIS. FULL SUN EXPECTED BY THIS AFTERNOON...AND WITH GUSTY
NORTHWEST FLOW HAVE GONE A COUPLE OF DEGREES ABOVE GUIDANCE FOR
HIGHS. TONIGHT WITH CLEAR SKIES TEMPERATURES WILL FALL INTO THE
MID 30S TO AROUND 40. FRIDAY...AS WEAK RIDGE CONTINUES TO MOVE
EAST INTO THE NORTHERN PLAINS...EXPECT CONTINUED DRY AND WEAK
SOUTHWEST FLOW AS A WEAK SURFACE TROUGH TRANSITIONS TO THE EAST
ACROSS WESTERN NEBRASKA WITH A VERY DRY AIRMASS IN PLACE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE
PACIFIC COAST FRIDAY EVENING...AND PROGRESS EASTWARD INTO THE
CENTRAL PLAINS DURING THE WEEKEND. THE 24/00Z MODEL RUNS HAVE ALL
SHIFTED THE TRACK OF THE STORM NORTH...WITH A NEARLY STACKED H5/H7
CIRCULATION CENTER LOCATED INVOF NORTHEAST COLORADO OR WESTERN
NEBRASKA AT 00Z MONDAY 28TH APRIL. GEFS ALSO CLUSTERING A AN H5
CIRCULATION CENTER IN THE SAME AREA. OPERATIONAL MODELS AND THE GEFS
ALL INDICATE A VERY DEEP SURFACE LOW /NEAR 983MB/ IN THE SAME
GENERAL AREA. THIS WILL BE A VERY DYNAMIC SYSTEM...WITH UNMODIFIED
RICH GULF MOISTURE STREAMING NORTHWARD INTO THE PLAINS. THIS
SPELLS SEVERE THUNDERSTORMS AND HEAVY RAINFALL IN AREAS. THE
CAVEAT TO ALL OF THIS WILL BE A PRONOUNCED DRY SLOT...THAT WILL
IMPACT SOME PORTION OF THE CENTRAL PLAINS. WITH TONIGHTS NORTHWARD
SHIFT IN THE MODELS...THIS DRY SLOT WOULD IMPACT PART OR ALL OF
THE NWS NORTH PLATTE FORECAST AREA SOMETIME DURING THE WEEKEND. AT
THIS POINT HOWEVER...THE SYSTEM IS STILL WELL OFFSHORE AND NOT
BEING SAMPLED BY UPPER AIR OBSERVING NETWORK. THEREFORE AM
HESITANT TO MAKE MAJOR CHANGES TO THE CURRENT FORECAST. IF THE
MODELS CONTINUE TO FAVOR A NORTHWARD TRACK IN FUTURE RUNS...THEN
WILL HAVE TO WARM HIGHS AND CUT PRECIPITATION CHANCES FOR PART OF
THE WEEKEND.
EARLY NEXT WEEK...THE AREA WILL CONTINUE TO BE IMPACTED FROM THIS
LARGE SLOW MOVING STORM SYSTEM. HOW THIS WHOLE SYSTEM EVOLVES COULD
BE QUITE INTERESTING. FOR EXAMPLE...THE LATEST 24/00Z ECMWF DUMBBELLS
A SECOND UPPER LOW WESTWARD FROM EASTERN CANADA...EVENTUALLY MERGING
THE TWO SYSTEM TOGETHER LATE MONDAY INTO TUESDAY...SENDING A LARGE
SHIELD OF RAIN WEST ACROSS THE AREA. THIS IS JUST ONE POSSIBLE
SCENARIO. FOR NOW...HAVE LOW CONFIDENCE ON HOW THIS WILL ALL PAN
OUT...AND WILL KEEP A CHANCE FOR RAIN AND COOL TEMPERATURES GOING
THROUGH AT LEAST TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 626 AM CDT THU APR 24 2014
MID AND HIGH CLOUDS CLEARING OUT OVER WESTERN NEBRASKA THIS
MORNING WEST OF A LINE FROM KVTN TO KOGA P6SM SKC. SKIES WILL
CLEAR WEST OF A LINE FROM KONL TO KBBW THROUGH NOON CDT. WEST TO
NORTHWEST WINDS WILL INCREASE THROUGH THE MORNING TO 10 TO 20 MPH
WITH HIGHER GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 311 AM CDT THU APR 24 2014
HAVE ISSUED A RED FLAG WARNING FOR ALL OF WESTERN NEBRASKA THIS
AFTERNOON FOR LOW RELATIVE HUMIDITY AND WINDS. GARFIELD...WHEELER
AND SOUTHERN HOLT COUNTIES RECEIVED LESS THAN A QUARTER OF AN INCH
OF PRECIPITATION OVER NIGHT IN FIRE ZONE 209 BUT THE MAJORITY OF
THAT ZONE WAS TRACE AMOUNTS OR A HUNDREDTH OF AN INCH AT BEST. THE
REMAINDER OF WESTERN NEBRASKA SAW A HUNDREDTH OR LESS OF
PRECIPITATION. MINIMUM RELATIVE HUMIDITIES FELL INTO THE SINGLE
DIGITS AND TEENS YESTERDAY OVER MOST OF THE FORECAST AREA. THINGS
ARE STARTING TO GREEN UP BUT FUELS ARE STILL FAVORABLE. LOOKING TO
THE WEST ACROSS THE BORDER IN WYOMING VERY DRY AIR MASS UNDER THE
HIGH PRESSURE SYSTEM...WITH DEW POINTS IN THE SINGLE DIGITS AND
TEENS. STRONG NORTHWEST FLOW WILL DIMINISH ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON. WINDS SHOULD REMAIN
GUSTY TROUGH AT LEAST EARLY AFTERNOON HOWEVER. MINIMUM RH WILL
FALL INTO THE TEENS OVER THE ENTIRE FORECAST AREA AND MAY FALL
INTO THE SINGLE DIGITS OVER SOUTHWEST NEBRASKA AND THE SOUTHEAST
NEBRASKA PANHANDLE. ALL OF WESTERN NEBRASKA IN THE DAY 1 STORM
PREDICTION CENTER FIRE WEATHER OUTLOOK. FIRE WEATHER MAY BE A
CONCERN AGAIN ON FRIDAY WITH LOW RH BUT LIGHTER WINDS WILL BE
LIMITING FACTOR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ204-206-208>210-219.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...POWER
LONG TERM...TAYLOR
AVIATION...POWER
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1032 AM MDT THU APR 24 2014
.UPDATE...
ISSUED AT 1031 AM MDT THU APR 24 2014
CURRENT FORECASTS LOOK IN GOOD SHAPE. FLOW ALOFT BECOMING
NORTHWEST AS UPPER RIDGE BUILDS OVER THE GREAT BASIN. AIRMASS TO
BE DRY...STABLE AND SLIGHTLY COOLER WITH SOME MID AND HIGH LEVEL
MOISTURE DURING THE AFTERNOON. SURFACE HIGH OVER WESTERN COLORADO
ALONG WITH LOWERING PRESSURE OVER KANSAS CREATING GUSTY WINDS
ACROSS THE MOUNTAINS...FOOTHILLS AND NORTHEAST CORNER. WEAK
ANTICYCLONE BEGINNING TO DEVELOP NEAR DIA...CREATING WEAKER WINDS
ALONG THE FRONT RANGE AND NEARBY PLAINS WITH MORE OF A SOUTHERLY
COMPONENT. LATEST MODELS SHOW THIS PATTERN PERSISTING THROUGH THE
DAY...WITH GUSTY WEST TO NORTHWEST WINDS MOST LOCATIONS EXPECT IN
THE DENVER AREA WHERE LIGHT SOUTHERLY WINDS WILL PREVAIL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 351 AM MDT THU APR 24 2014
NORTHWEST FLOW ALOFT WILL PREVAIL BEHIND THE EXITING TROUGH AND THE
APPROACHING RIDGE TODAY. THIS WILL BRING DRY CONDITIONS AND MOSTLY
SUNNY SKIES. SOME HIGH CLOUDS WILL PASS OVER THE TOP OF THE RIDGE
LATER IN THE DAY. AIRMASS WILL BE SLIGHTLY COOLER TODAY WHICH WILL
PUT MOST LOCATIONS IN THE 60S FOR HIGHS. SURFACE HIGH PRESSURE OVER
THE GREAT BASIN AND LOWER PRESSURE OVER THE CENTRAL PLAINS WILL
PRODUCE MAINLY WEST TO NORTHWEST WINDS. HOWEVER AN ANTI-CYCLONE MAY
FORM AND CAUSE WINDS TO TURN SOUTHERLY ALONG THE FRONT RANGE AND
PARTS OF THE PLAINS THIS AFTERNOON.
THE UPPER LEVEL RIDGE WILL MOVE ACROSS THE STATE TONIGHT. THIS WILL
CONTINUE TO KEEP THE AREA PRECIPITATION FREE. THERE WILL BE SOME
MOISTURE AT THE MID AND UPPER LEVEL OF THE ATMOSPHERE WHICH WILL
LEAD TO MID AND HIGH CLOUDS AT TIMES. OVERNIGHT LOWS WILL AGAIN BE
MILD WITH READINGS MAINLY IN THE UPPER 30S TO MID 40S OVER NORTHEAST
COLORADO.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM MDT THU APR 24 2014
ATTENTION OVER THE NEXT FEW DAYS CERTAINLY SURROUNDS DEEP UPPER
LEVEL TROUGH WHICH IS EXPECTED TO DROP INTO THE SOUTHWESTERN
UNITED STATES AND THEN DEEPEN SIGNIFICANTLY SOMEWHERE OVER THE
CENTRAL HIGH PLAINS. MODEL CONSENSUS IS COMING AROUND TO A MORE
CONSISTENT PATH...ALTHOUGH DIFFERENCES ON TIMING AND TRENDS STILL
ABOUND. AT THIS TIME...PER WATER VAPOR LOOP SEEMS LIKE THE ECMWF
HAS A HANDLE ON THE SIGNIFICANT PIECES OF ENERGY IN THE PACIFIC
BETWEEN 140W AND 170E. THIS SHOULD ALLOW AMPLE BUCKLING OF THE
FLOW WITH A RATHER SHARP TROUGH REACHING THE WEST COAST FRIDAY. IF
THE SHARPER TROUGH SOLUTION IS CORRECT...THEN WOULD PREFER THE
SLOWER AND EVER SO SLIGHTLY DEEPER SOLUTION OFFERED BY THE ECMWF.
FOR FRIDAY....DEEP WARM ADVECTION WILL OCCUR WITH LEE TROUGHING
AND WARM/RIDGING SOUTHWEST FLOW ALOFT. THIS SHOULD ALLOW
TEMPERATURES TO WARM 10-15 DEGREES ABOVE NORMAL. INCREASING
SOUTHERLY WINDS ESPECIALLY OVER THE PALMER DIVIDE AREA WILL LEAD
TO INCREASING FIRE DANGER BUT MOST OF THAT AREA SAW LIGHT/MODERATE
PRECIPITATION LAST NIGHT AND GREEN-UP CONTINUES. ONLY MARGINAL
AREA WOULD BE SOUTHERN LINCOLN COUNTY AGAIN.
BY SATURDAY...THE DIGGING TROUGH TO OUR WEST AND CONTINUED WARM
ADVECTION WILL BRING ANOTHER VERY WARM DAY TO THE FORECAST AREA.
HAVE BOOSTED HIGHS SEVERAL DEGREES FOR SATURDAY CONSIDERING THE
WARM ADVECTION...STRONG LEE TROUGHING AND MIXING...AND ONLY SLIGHT
INCREASE IN CLOUDS DURING THE DAY. FIRE DANGER WILL INCREASE AGAIN
OVER THE PLAINS WITH STRONG AND DRY SOUTH/SOUTHWEST WINDS.
WITH REGARD TO SEVERE WEATHER THREAT LATE SATURDAY AFTERNOON/
SATURDAY NIGHT...THE AMOUNT OF DRY AIR AHEAD OF SYSTEM APPEARS TO
BE QUITE SUBSTANTIAL. ALMOST ALL MODELS SUGGEST A DRYLINE PUSHING
WELL EAST INTO THE CENTRAL PLAINS...BUT MODELS USUALLY OVERDO
THIS EASTWARD PUSH OF THE DRYLINE WHEN DEEP PRESSURE FALLS OCCUR
IN EASTERN COLORADO. AT THIS TIME...WHILE WE DONT THINK THE
DRYLINE WILL PUSH AS FAR EAST AS MODELS SUGGEST...IT WOULD BE HARD
TO GET THE DEEPER MOISTURE TO HOLD EVEN OVER THE NORTHEAST CORNER.
WILL STILL MENTION SOME THREAT IN THE HAZARDOUS WEATHER OUTLOOK
AND A COUPLE OF THE SREF PLUMES ARE SHOWING NEAR 1000 J/KG CAPE
OVER THE NORTHEAST CORNER.
Q-G LIFT INCREASES SIGNIFICANTLY AND IS DEEP AND STRONG WITH THE
UPPER LEVEL TROUGH...AGAIN DEPENDING ON ITS EXACT MOVEMENT. THIS
WOULD RESULT IN HIGHER SHOWER AND STORM COVERAGE SATURDAY NIGHT
INTO SUNDAY MORNING ALTHOUGH TIMING IS STILL SOMEWHAT IN QUESTION.
WILL TREND POP FORECAST TOWARD ECMWF SOLUTION FOR NOW GIVEN
PREFERENCE MENTIONED ABOVE. IF SYSTEM CONTINUES TO PULL TO THE
NORTHEAST...THEN STRONGER DOWNSLOPE WOULD BE DEVELOPING BY SUNDAY
WITH DRIER AIR ESPECIALLY ALONG THE FRONT RANGE WHERE DOWNSLOPE IS
MAXIMIZED. MEANWHILE...IN THE MOUNTAINS STRONG OROGRAPHIC FLOW
DEVELOPING ON BACKSIDE OF UPPER TROUGH COMBINED WITH MID LEVEL
INSTABILITY AND LIFT COULD PRODUCE A SIGNIFICANT SNOWFALL FOR THE
HIGH COUNTRY. STILL TOO EARLY TO ISSUE ANY WATCHES BUT POTENTIAL
IS CERTAINLY THERE. WITH REGARD TO FOOTHILL QPF AND POTENTIAL
RUNOFF...IF PERSISTENCE DUE TO ANY SLOWER STORM MOTION OR UPSLOPE
WOULD OCCUR THEN PRECIPITATION WOULD LIKELY CHANGE TO SNOW AT MOST
ELEVATIONS ABOVE 7000-7500 FEET. THAT WOULD EFFECTIVELY LIMIT ANY
RUNOFF EVEN IF STORM IS SLOWER/DEEPER THAN MOST MODEL RUNS
INDICATE.
FOR MONDAY-WEDNESDAY...A DEEP AND CLOSED UPPER TROUGH SEEMS
CONTENT TO SPIN OVER THE MIDWEST. THIS WOULD KEEP TEMPERATURES
ABOUT 10 DEGREES BELOW NORMAL ALONG WITH A LOW CHANCE OF SHOWERS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1031 AM MDT THU APR 24 2014
CURRENT TAF TRENDS LOOK ON TRACK. WEAK ANTICYCLONE DEVELOPING JUST
NORTHWEST OF DENVER CREATING SOUTHEASTERLY WINDS ACROSS THE AREA
AIRPORTS. BOTH THE RAP AND HRRR MOVE THE ANTICYLONE EAST OF DENVER
AROUND 21Z...WITH WESTERLY WINDS MOVING OFF THE FOOTHILLS ACROSS
THE DENVER AREA. THIS ALREADY NOTED IN THE LAST TAF UPDATE FOR
KDEN AND KBJC. WILL CONTINUE FOR THE UPCOMING ISSUANCE. THERE IS
A SLIGHT CHANCE FOR THE WESTERLY WINDS OCCURRING AT KAPA BUT WILL
HOLD OFF FOR NOW. VFR TO PREVAIL WITH SOME MID AND HIGH LEVEL
MOISTURE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...D-L
SHORT TERM...MEIER
LONG TERM...BARJENBRUCH
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
228 PM CDT THU APR 24 2014
.DISCUSSION...
351 AM CDT
MAIN FOCUS THIS MORNING IS WITH SLOWER PROGRESSION OF SURFACE LOW
AND COLD FRONT AND ASSOCIATED RAIN ESPECIALLY LATE TODAY/TONIGHT.
BREEZY/MILD DAY FRIDAY...BEFORE SECOND COLD FRONT PASSES FRIDAY
EVENING AND SETS STAGE FOR PROLONGED PERIOD OF COOL/WET WEATHER
ESPECIALLY SATURDAY NIGHT-WEDNESDAY.
BAND OF SHOWERS/GRAUPEL WITH LEAD SHORT WAVE TROUGH CONTINUES TO
LIFT NORTHEAST ACROSS NORTH/NORTHEAST PARTS OF THE CWA AT 0830Z.
DRYING EVIDENT UPSTREAM INTO WESTERN IL/MO...WITH NEAR TERM GUIDANCE
IN GOOD AGREEMENT IN SUGGESTING MOST OF FORECAST AREA WILL SEE DRY
WEATHER FOR MUCH OF THE MORNING/EARLY AFTERNOON HOURS AS INITIAL
ELEVATED WARM FRONTAL PRECIP LIFTS NORTH OF THE AREA. TREND IN MODEL
GUIDANCE OVER THE PAST 24 HOURS HAS BEEN TO SLOW EASTWARD
PROGRESSION OF COLD FRONT...WITH DEEPER SOUTHERN STREAM SHORT WAVE
ALSO RESULTING IN SURFACE LOW REFLECTION TRACKING FARTHER SOUTH
ACROSS CENTRAL IL. OVERALL...ONLY REAL CHANGE TO GOING FORECAST WAS
TO SLOW ARRIVAL AND DEPARTURE OF HIGHER POPS WITH THE FRONT THROUGH
TONIGHT. WITH STEADIER RAINFALL TONIGHT...STILL LOOKS TO BE ABOUT A
HALF INCH AREA WIDE. FORECAST SOUNDINGS INDICATE LAPSE RATES NOT
PARTICULARLY IMPRESSIVE...AND HAVE ONLY INDICATED ISOLATED THUNDER
MAINLY WITH APPROACH OF COLD LATE TODAY/TONIGHT. FRONT CLEARS
EASTERN CWA AROUND SUNRISE FRIDAY MORNING...WITH WEAK FLAT SURFACE
RIDGE DEVELOPING ACROSS THE AREA DURING THE DAY. DEEPER MIXING AND
SUBSIDENCE INDICATE FRIDAY MAY BE THE MILDEST DAY OF THE STRETCH
WITH MID 60S-LOW 70S EXPECTED FROM FAR NORTH TO FAR SOUTH.
AS INDICATED OVER THE PAST FEW DAYS...ANOTHER COLD FRONT ASSOCIATED
WITH NORTHERN STREAM DISTURBANCE DOES SETTLE SOUTH ACROSS THE
FORECAST AREA FRIDAY EVENING. MODELS CONTINUE TO HAVE SOME
DIFFICULTY PINNING DOWN EXACT TIMING/PLACEMENT OF THE FRONT AS IT
SLOWS UP OVER CENTRAL IL/IN FRIDAY NIGHT...THOUGH MOST GUIDANCE DOES
INDICATE POTENTIAL FOR SOME SPOTTY LIGHT PRECIP AS FRONT UNDERCUTS
WEST-SOUTHWEST FLOW ALOFT. WITH CONFIDENCE IN TIMING/PLACEMENT OF
ANY LIGHT SHOWERS RATHER LOW...HAVE BROAD-BRUSHED SLIGHT CHANCE
OVERNIGHT THOUGH NOT EXPECTING RAIN TO AMOUNT TO MUCH.
BRIEF INTRUSION OF HIGH PRESSURE RIDGING FROM THE NORTH ON SATURDAY
EXPECTED TO YIELD DRY BUT COOLER WEATHER...BEFORE STATIONARY FRONTAL
BOUNDARY TO OUR SOUTH BECOMES FOCUS FOR PRECIP DEVELOPMENT SATURDAY
NIGHT THROUGH THE EXTENDED PORTION OF THE FORECAST AS CLOSED UPPER
LOW AND ITS ASSOCIATED SURFACE CIRCULATION SLOWLY WOBBLES FROM THE
PLAINS TO THE GREAT LAKES REGION THROUGH THE MIDDLE OF NEXT WEEK.
COOL AND GENERALLY WET WEATHER TO PREDOMINATE...WITH EAST-NORTHEAST
LOW LEVEL WINDS AND PERSISTENT MOIST ASCENT FROM THE SOUTH ABOVE THE
STATIONARY BAROCLINIC ZONE TO OUR SOUTH. GUIDANCE HAS TRENDED
GENERALLY WARMER ALOFT SUNDAY-TUESDAY...THOUGH AFOREMENTIONED LOW
LEVEL WINDS OFF LAKE MICHIGAN WILL LIKELY MAKE FOR A FAIRLY LARGE
GRADIENT FROM NORTH TO SOUTH FOR MUCH OF THE PERIOD...WITH HIGHS
ALONG THE LAKE IN THE 40S...WHILE 60S ARE MORE PREVALENT SOUTH OF
THE I-80 CORRIDOR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY SOUTHEAST WINDS THIS AFTERNOON AND EVENING...DIMINISHING
MID EVENING...THEN TURNING TO THE NORTHWEST OVERNIGHT INTO EARLY
FRIDAY.
* CHANCES FOR SHOWERS THIS EVENING/TONIGHT RESULTING IN MVFR
CONDITIONS.
BMD
//DISCUSSION...UPDATED 18Z...
A BROAD AREA OF LOW PRESSURE LIES OVER THE PLAINS THIS AFTERNOON.
AHEAD OF THE LOW THIS AFTERNOON AND EVENING...EXPECT GUSTY SOUTHEAST
WINDS TO CONTINUE ACROSS NORTHERN ILLINOIS...WITH GUSTS PUSHING 30
KT AT TIMES. THIS LOW WILL CONSOLIDATE AS IT MOVES EAST ACROSS
CENTRAL ILLINOIS LATE THIS EVENING/TONIGHT. SHOWERS ALONG WITH
LOWERING CIGS WILL ACCOMPANY THE LOW THIS EVENING. CIGS ARE EXPECTED
TO LOWER TO MVFR...AND CANNOT COMPLETELY RULE OUT IFR AT THIS
TIME...THOUGH THERE ARE BETTER CHANCES FOR CIGS BOTTOMING OUT IN THE
010-015 RANGE. WINDS MAY GO VARIABLE FOR A BRIEF PERIOD AS AN
INVERTED TROUGH PUSHES ACROSS THE AREA...THEN EXPECT WINDS TO BECOME
NNW TO NW BEHIND THE TROUGH WITH CONDITIONS QUICKLY RETURNING TO VFR.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN PRECIP TIMING/IMPACTS TO VSBY THIS
EVENING.
* HIGH CONFIDENCE IN MVFR CIGS...LOW CONFIDENCE IN IFR.
* HIGH CONFIDENCE IN WIND DIRECTION/SPEED THIS AFTERNOON AND EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF SHOWERS...OTHERWISE VFR.
SATURDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
158 PM CDT
TWO WEAK LOW PRESSURE CENTERS WERE LOCATED WEST OF LAKE MICHIGAN.
ONE WAS STEADILY WEAKENING OVER CENTRAL IOWA...WHILE A SECOND WAS
BEGINNING TO STRENGTHEN ACROSS CENTRAL MISSOURI. THE TWO LOW
PRESSURES ARE EXPECTED TO CONSOLIDATE THIS EVENING...THEN STEADILY
LIFT NORTHEAST/EAST ACROSS CENTRAL ILLINOIS OVERNIGHT. IN THE
MEANTIME...WINDS WILL GENERALLY REMAIN EASTERLY TO SOUTHEASTERLY.
A TIGHT GRADIENT DOES EXIST...WHICH HAS RESULTED IN WINDS AT TIMES
GUSTING TO 30KT THIS AFTN. GUIDANCE HAS BEEN CONSISTENT IN
DEPICTING WINDS DIMINISHING TONIGHT...THEN WINDS WILL TURN
WEST/NORTHWEST. THIS WILL ALLOW THE WAVES TO SUBSIDE ACROSS THE
NORTH/NORTHWEST PORTIONS OF THE LAKE...WHILE WAVES BEGIN TO BUILD
ONCE AGAIN FOR THE INDIANA NEARSHORE WATERS FRIDAY MIDDAY THROUGH
FRIDAY NIGHT.
HIGH PRESSURE WILL SLIDE EAST ACROSS MANITOBA TO NORTH OF LAKE
SUPERIOR EARLY SATURDAY. THIS WILL ALLOW WINDS TO TURN NORTHERLY
EARLY SATURDAY THEN NORTHEAST TO EASTERLY ACROSS THE LAKE BY
SATURDAY AFTERNOON. THEN A PROLONGED PERIOD OF GENERALLY EASTERLY
WINDS IS EXPECTED ACROSS THE LAKE SUNDAY THROUGH TUESDAY.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1259 PM CDT Thu Apr 24 2014
.DISCUSSION...
ISSUED 1046 AM CDT Thu Apr 24 2014
Area of low pressure currently located near Kansas City will track
slowly E/NE into west-central Illinois by this evening. While
showers and thunderstorms are prevalent ahead of this feature
across central and western Missouri, the airmass further east over
Illinois remains rather dry. 15z/10am surface dewpoints are only
in the middle to upper 30s, while the 12z KILX upper air sounding
showed a large amount of dry air below 700mb. With a southeasterly
low-level flow ahead of the system, am not expecting much moisture
advection before the low and its associated front arrive. High-res
models such as the HRRR and the NAM12 are suggesting that the
eastward progression of the precip will be slower than previously
expected and this seems reasonable given the current conditions.
Have therefore trimmed POPs back today. Will keep the entire KILX
CWA dry through midday, then will slowly advance precip eastward
this afternoon. Will continue with a dry forecast east of the
I-57 corridor through the entire afternoon, with POPs gradually
ramping up to categorical further west across the Illinois River
Valley. Also made adjustments to sky cover to feature more
sunshine across the E/SE. Zone update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 1259 PM CDT Thu Apr 24 2014
Showers are beginning to spread into the Illinois River Valley and
may impact KPIA over the next couple of hours. However, overall
trend has been for precip to diminish as it moves eastward into the
dry airmass over Illinois. As atmosphere slowly moistens and upper
wave and its associated cold front approach from the west, showers
will gradually become more prevalent across west-central Illinois
late this afternoon, then will spread eastward across the
remainder of the area during the evening. Most model guidance
suggests KCMI will remain dry until mid-evening at the earliest.
Time-height cross-sections generally reveal MVFR ceilings with
skies clearing from west to east after midnight. Will end the
showers and clear skies at KPIA at 08z, then further east to KCMI
by around 12z. Winds will initially be gusty from the southeast
this afternoon, then will become northwesterly after FROPA later
this evening.
Barnes
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Apr 24 2014
SHORT TERM...Today through Sunday
00Z models continue to be slower with cold frontal passage and
associated convection and that is the biggest change in the
forecast package. Most areas will be dry this morning with showers
and thunderstorms affecting areas from I-55 west this afternoon
and possibly getting as far east as I-57 late this afternoon. SPC
keeps slight risk of severe storms in southern IL south of our
CWA. Though there is a 5% risk of damaging wind gusts in far sw CWA
from Springfield to Lawrenceville south late this afternoon and
evening. Upper level trof over CO/NM with embedded short wave to
move into IL overnight while a cold front moves east across IL
during tonight. Have increased pops this evening due to slower
movement of front and then decreasing pops from west to east
behind cold front during overnight. Highs today in the upper 60s
nw over IL river valley to mid 70s se of I-70. Lows tonight 45-50F
over central IL and 50-55F in southeast IL. Rainfall amounts this
afternoon and tonight of a half to three quarter inch with locally
three quarter to 1 inch west of I-55.
Storm system to pass east of IL across IN/OH Friday morning with
more sunshine returning and mild highs in the low to mid 70s and
warmest over sw counties. Even a few degrees warmer on Saturday as
models have 850 mb temps of 12-14C. Still appears dry Friday
through the day on Saturday with partly to mostly sunny skies Sat.
Rather mild again on Sunday with highs in the upper 60s to mid 70s.
Models have trended warmer this weekend ahead of next storm system
over the Rockies. Continue chances of showers and isolated
thunderstorms Saturday night and Sunday as warm air advection
regime sets up again.
LONG TERM...Sunday night through Thursday
Extended models like GFS, ECMWF and GEM develop a strong/large cutoff
upper level low near CO Sunday morning and then move it into the MO
valley Tue and mid MS river valley during middle of next week.
This to bring an unsettled weather pattern with daily chance of
showers and isolated thunderstorms from Sunday through Thursday
with highest chances Sunday night through Tuesday. Mild temps
early in the week to cool by middle of next week as upper level
low moves near IL. Widespread rainfall amounts of 1-2 inches
expected during this time with heaviest amounts southern areas.
Seasonable highs in the upper 60s and lower 70s Monday cool into
the low to mid 50s Wed/Thu.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1111 AM CDT THU APR 24 2014
.DISCUSSION...
351 AM CDT
MAIN FOCUS THIS MORNING IS WITH SLOWER PROGRESSION OF SURFACE LOW
AND COLD FRONT AND ASSOCIATED RAIN ESPECIALLY LATE TODAY/TONIGHT.
BREEZY/MILD DAY FRIDAY...BEFORE SECOND COLD FRONT PASSES FRIDAY
EVENING AND SETS STAGE FOR PROLONGED PERIOD OF COOL/WET WEATHER
ESPECIALLY SATURDAY NIGHT-WEDNESDAY.
BAND OF SHOWERS/GRAUPEL WITH LEAD SHORT WAVE TROUGH CONTINUES TO
LIFT NORTHEAST ACROSS NORTH/NORTHEAST PARTS OF THE CWA AT 0830Z.
DRYING EVIDENT UPSTREAM INTO WESTERN IL/MO...WITH NEAR TERM GUIDANCE
IN GOOD AGREEMENT IN SUGGESTING MOST OF FORECAST AREA WILL SEE DRY
WEATHER FOR MUCH OF THE MORNING/EARLY AFTERNOON HOURS AS INITIAL
ELEVATED WARM FRONTAL PRECIP LIFTS NORTH OF THE AREA. TREND IN MODEL
GUIDANCE OVER THE PAST 24 HOURS HAS BEEN TO SLOW EASTWARD
PROGRESSION OF COLD FRONT...WITH DEEPER SOUTHERN STREAM SHORT WAVE
ALSO RESULTING IN SURFACE LOW REFLECTION TRACKING FARTHER SOUTH
ACROSS CENTRAL IL. OVERALL...ONLY REAL CHANGE TO GOING FORECAST WAS
TO SLOW ARRIVAL AND DEPARTURE OF HIGHER POPS WITH THE FRONT THROUGH
TONIGHT. WITH STEADIER RAINFALL TONIGHT...STILL LOOKS TO BE ABOUT A
HALF INCH AREA WIDE. FORECAST SOUNDINGS INDICATE LAPSE RATES NOT
PARTICULARLY IMPRESSIVE...AND HAVE ONLY INDICATED ISOLATED THUNDER
MAINLY WITH APPROACH OF COLD LATE TODAY/TONIGHT. FRONT CLEARS
EASTERN CWA AROUND SUNRISE FRIDAY MORNING...WITH WEAK FLAT SURFACE
RIDGE DEVELOPING ACROSS THE AREA DURING THE DAY. DEEPER MIXING AND
SUBSIDENCE INDICATE FRIDAY MAY BE THE MILDEST DAY OF THE STRETCH
WITH MID 60S-LOW 70S EXPECTED FROM FAR NORTH TO FAR SOUTH.
AS INDICATED OVER THE PAST FEW DAYS...ANOTHER COLD FRONT ASSOCIATED
WITH NORTHERN STREAM DISTURBANCE DOES SETTLE SOUTH ACROSS THE
FORECAST AREA FRIDAY EVENING. MODELS CONTINUE TO HAVE SOME
DIFFICULTY PINNING DOWN EXACT TIMING/PLACEMENT OF THE FRONT AS IT
SLOWS UP OVER CENTRAL IL/IN FRIDAY NIGHT...THOUGH MOST GUIDANCE DOES
INDICATE POTENTIAL FOR SOME SPOTTY LIGHT PRECIP AS FRONT UNDERCUTS
WEST-SOUTHWEST FLOW ALOFT. WITH CONFIDENCE IN TIMING/PLACEMENT OF
ANY LIGHT SHOWERS RATHER LOW...HAVE BROAD-BRUSHED SLIGHT CHANCE
OVERNIGHT THOUGH NOT EXPECTING RAIN TO AMOUNT TO MUCH.
BRIEF INTRUSION OF HIGH PRESSURE RIDGING FROM THE NORTH ON SATURDAY
EXPECTED TO YIELD DRY BUT COOLER WEATHER...BEFORE STATIONARY FRONTAL
BOUNDARY TO OUR SOUTH BECOMES FOCUS FOR PRECIP DEVELOPMENT SATURDAY
NIGHT THROUGH THE EXTENDED PORTION OF THE FORECAST AS CLOSED UPPER
LOW AND ITS ASSOCIATED SURFACE CIRCULATION SLOWLY WOBBLES FROM THE
PLAINS TO THE GREAT LAKES REGION THROUGH THE MIDDLE OF NEXT WEEK.
COOL AND GENERALLY WET WEATHER TO PREDOMINATE...WITH EAST-NORTHEAST
LOW LEVEL WINDS AND PERSISTENT MOIST ASCENT FROM THE SOUTH ABOVE THE
STATIONARY BAROCLINIC ZONE TO OUR SOUTH. GUIDANCE HAS TRENDED
GENERALLY WARMER ALOFT SUNDAY-TUESDAY...THOUGH AFOREMENTIONED LOW
LEVEL WINDS OFF LAKE MICHIGAN WILL LIKELY MAKE FOR A FAIRLY LARGE
GRADIENT FROM NORTH TO SOUTH FOR MUCH OF THE PERIOD...WITH HIGHS
ALONG THE LAKE IN THE 40S...WHILE 60S ARE MORE PREVALENT SOUTH OF
THE I-80 CORRIDOR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* STRONG/GUSTY SOUTHEAST WINDS TODAY.
* SHOWERS LATER TONIGHT INTO EARLY FRIDAY MORNING.
* LOW END MVFR CEILINGS LIKELY TONIGHT INTO EARLY FRIDAY
MORNING...WITH A POSSIBILITY FOR IFR CEILINGS.
RODRIGUEZ/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
VFR CEILINGS IN PLACE THIS MORNING WITH ANY LINGERING SHOWERS WELL
NORTH/NORTHEAST OF THE TERMINALS AT THIS TIME. EXPECT DRY
CONDITIONS FOR MOST OF TODAY AND EVENING WITH ONLY MID/HIGH HIGH
LEVEL CLOUD COVER LIKELY FOR MOST OF TODAY. A SLOWER EVOLUTION OF
THE APPROACHING SYSTEM TODAY IS APPEARING LIKELY AND HAVE PUSHED
BACK TIMING OF SHOWERS TO LATER TONIGHT WHEN THIS TROUGH OF LOW
PRESSURE FINALLY ARRIVES. ALTHOUGH THERE DOES STILL APPEAR TO BE
SOME POSSIBLE ISOLATED LIGHT SHOWERS BEFORE THEN...EXPECT ANY
SHOWERS TO BRIEF AND LIGHT AND SO HAVE REMOVED THE VCSH MENTION
FOR EARLIER THIS EVENING. NOT EXPECTED THUNDER WITH THE SHOWERS
TONIGHT AS BEST INSTABILITY/MOISTURE WILL REMAIN WELL SOUTH OF ALL
THE TERMINALS. VFR CEILINGS THIS EVENING WILL LIKELY FALL TO LOW
END MVFR FOR A TIME TONIGHT INTO EARLY FRIDAY MORNING...WITH A
POSSIBILITY FOR SOME PERIODS OF IFR. CONFIDENCE IS LOW WITH
REGARDS TO THE IFR AND SO HAVE LEFT OUT ANY MENTION IN THE TAFS.
EAST SOUTHEAST WINDS ARE IN PLACE THIS MORNING AND ARE STEADILY
INCREASING AT THIS HOUR. WITH THE SURFACE GRADIENT BECOMING
ORGANIZED THIS MORNING...EXPECT WINDS/GUSTS TO RAPIDLY INCREASE
OVER THE NEXT COUPLE OF HOURS AND REMAIN HIGH THROUGH THE
AFTERNOON. GUSTS OF AROUND 30KT ARE POSSIBLE FOR A TIME
TODAY...BEFORE WINDS/GUSTS DIMINISH LATE IN THE AFTERNOON AND
EARLY EVENING. PERSISTENT SOUTHEAST WINDS WILL LIKELY BECOME MORE
VARIABLE WITHIN THE TROUGH/PRECIP AXIS LATER TONIGHT BEFORE
TURNING TO THE NORTHWEST ON THE BACKSIDE OF THIS SYSTEM...STAYING
THIS DIRECTION INTO FRIDAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH SHOWERS AND TIMING TONIGHT.
* MEDIUM HIGH CONFIDENCE WITH MVFR CEILINGS...WITH LOW CONFIDENCE
FOR POSSIBLE IFR CEILINGS.
RODRIGUEZ/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF SHOWERS...OTHERWISE VFR.
SATURDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
443 AM CDT
LIGHTER FLOW REMAINING OVER THE LAKE EARLY THIS MORNING WITH
WEAKER SURFACE PATTERN STILL IN PLACE. ALTHOUGH...EXPECT EAST TO
SOUTHEAST WINDS TO RAPIDLY INCREASE THROUGH MID MORNING AND THEN
ESPECIALLY INTO THE AFTERNOON WHEN TO 30 KT WINDS WILL BE
OBSERVED...IN RESPONSE TO AN APPROACHING TROUGH OF LOW PRESSURE.
EAST TO SOUTHEAST WINDS WILL STILL REMAIN TO 30 KT THIS EVENING
BUT SLOWLY DIMINISH AS THIS TROUGH OF LOW PRESSURE MOVES THROUGH
THE REGION. WINDS WILL BEGIN TURNING TO THE WEST/NORTHEAST ON THE
BACKSIDE OF THIS SYSTEM LATE TONIGHT INTO FRIDAY BEFORE TURNING
MORE NORTHERLY FRIDAY NIGHT INTO SATURDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1046 AM CDT Thu Apr 24 2014
.DISCUSSION...
ISSUED 1046 AM CDT Thu Apr 24 2014
Area of low pressure currently located near Kansas City will track
slowly E/NE into west-central Illinois by this evening. While
showers and thunderstorms are prevalent ahead of this feature
across central and western Missouri, the airmass further east over
Illinois remains rather dry. 15z/10am surface dewpoints are only
in the middle to upper 30s, while the 12z KILX upper air sounding
showed a large amount of dry air below 700mb. With a southeasterly
low-level flow ahead of the system, am not expecting much moisture
advection before the low and its associated front arrive. High-res
models such as the HRRR and the NAM12 are suggesting that the
eastward progression of the precip will be slower than previously
expected and this seems reasonable given the current conditions.
Have therefore trimmed POPs back today. Will keep the entire KILX
CWA dry through midday, then will slowly advance precip eastward
this afternoon. Will continue with a dry forecast east of the
I-57 corridor through the entire afternoon, with POPs gradually
ramping up to categorical further west across the Illinois River
Valley. Also made adjustments to sky cover to feature more
sunshine across the E/SE. Zone update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 625 AM CDT Thu Apr 24 2014
Several forecast concerns this period include surface wind gusts
later this morning into this afternoon and a deterioration in
cigs this evening as showers and scattered TSRA affect the TAF
sites. Band of showers was located over east central Iowa, tracking
mainly to the northeast and not expected to affect our TAF
locations this morning. However, as a frontal boundary out to our
west make progress to the east later today, the threat for showers
and storms will increase from west to east in the 20z-01z time
frame. Widespread rain and isold TSRA will be the story this
evening with the cigs gradually lowering to MVFR with some brief
IFR cigs possible where some of the heavier showers/storms move
through. Steadier light rains will follow later this evening
before the system shifts off to our east late tonight. Surface
winds will be out of the southeast at 15 to 25 kts today with
a few gusts around 30 kts at times. FROPA is not expected until
or just after 03z at PIA with CMI the last to see the wind shift
by 08z.
Smith
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Apr 24 2014
SHORT TERM...Today through Sunday
00Z models continue to be slower with cold frontal passage and
associated convection and that is the biggest change in the
forecast package. Most areas will be dry this morning with showers
and thunderstorms affecting areas from I-55 west this afternoon
and possibly getting as far east as I-57 late this afternoon. SPC
keeps slight risk of severe storms in southern IL south of our
CWA. Though there is a 5% risk of damaging wind gusts in far sw CWA
from Springfield to Lawrenceville south late this afternoon and
evening. Upper level trof over CO/NM with embedded short wave to
move into IL overnight while a cold front moves east across IL
during tonight. Have increased pops this evening due to slower
movement of front and then decreasing pops from west to east
behind cold front during overnight. Highs today in the upper 60s
nw over IL river valley to mid 70s se of I-70. Lows tonight 45-50F
over central IL and 50-55F in southeast IL. Rainfall amounts this
afternoon and tonight of a half to three quarter inch with locally
three quarter to 1 inch west of I-55.
Storm system to pass east of IL across IN/OH Friday morning with
more sunshine returning and mild highs in the low to mid 70s and
warmest over sw counties. Even a few degrees warmer on Saturday as
models have 850 mb temps of 12-14C. Still appears dry Friday
through the day on Saturday with partly to mostly sunny skies Sat.
Rather mild again on Sunday with highs in the upper 60s to mid 70s.
Models have trended warmer this weekend ahead of next storm system
over the Rockies. Continue chances of showers and isolated
thunderstorms Saturday night and Sunday as warm air advection
regime sets up again.
LONG TERM...Sunday night through Thursday
Extended models like GFS, ECMWF and GEM develop a strong/large cutoff
upper level low near CO Sunday morning and then move it into the MO
valley Tue and mid MS river valley during middle of next week.
This to bring an unsettled weather pattern with daily chance of
showers and isolated thunderstorms from Sunday through Thursday
with highest chances Sunday night through Tuesday. Mild temps
early in the week to cool by middle of next week as upper level
low moves near IL. Widespread rainfall amounts of 1-2 inches
expected during this time with heaviest amounts southern areas.
Seasonable highs in the upper 60s and lower 70s Monday cool into
the low to mid 50s Wed/Thu.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1245 PM CDT THU APR 24 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
PRIMARY CONCERNS TODAY WILL BE INTERRELATED PRECIP AND TEMP TRENDS
WITH NOT THE GREATEST CONFIDENCE IN EITHER...ESPECIALLY TEMPS. LONG
WAVE TROUGH IS STILL WELL TO THE WEST JUST EXITING THE ROCKIES AND
ASSOCIATED KINEMATIC FORCING SEEMS TO BE THE MAIN MECHANISM DRIVING
CURRENT KS/NE PRECIP BEHIND THE INVERTED TROUGH. THERMODYNAMIC
FORCING SEEMS TO BE MAINLY RESPONSIBLE FOR IA/MN PRECIP AND LOOKS TO
GRADUALLY BECOME THE DOMINATE FORCING LATER IN THE DAY. EXPECT THE
NE/KS PRECIP TO WANE AND BE REPLACED BY WEAK CONVECTION NOW
INCREASING SOMEWHAT ALONG THE I35 CORRIDOR AND MOISTURE TRANSPORT
AXIS. LATEST HIGH RES MODELS SEEM TO HAVE A DECENT HANDLE ON THIS
PROGRESSION AS WELL...WHICH EVENTUALLY ENDS UP WITH LINGERING POPS
IN THE EAST 21Z-00Z. INSTABILITY IS FAIRLY WEAK AT THE MOMENT WITH
MUCAPES JUST A FEW HUNDRED. MAX AXIS...STILL ONLY AROUND 500
J/KG...IS STILL OFF TO THE WEST HOWEVER SO THERE MAY BE A MINOR
UPTICK IN INTENSITY THROUGH THE MORNING WITH SOME SMALL HAIL
POSSIBLE...STILL BELOW SEVERE LIMITS. THE ERN THIRD OF THE FORECAST
AREA MAY SEE ANOTHER HALF INCH PLUS OF BENEFICIAL RAINS.
TEMP GUIDANCE IS QUITE VARIED WITH A DECENT SPREAD IN BOTH RAW AND
MOS VALUES. 8F DIFFERENCE IN DSM MOS FOR INSTANCE. SOME
MODELS...ESPECIALLY RECENT RAP RUNS...WERE MORE AGGRESSIVE MIXING
TODAY WHILE OTHERS KEEP MORE LOW LEVEL MOISTURE IN PLACE. DO NOT
REALLY HAVE A GOOD FEELING WHICH WAY TO LEAN HERE SO FOLLOWED MORE
OF A BLEND...WHICH IS JUST SLIGHTLY LOWER THAN PERSISTENCE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
SYSTEM SHOULD QUICKLY EXIT THE STATE THIS EVENING...WITH SOME
LINGERING LIGHT SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE
FAR SOUTHEASTERN CWA EARLY IN THE EVENING. OTHERWISE UPPER LEVEL
RIDGING TO BUILD INTO THE CENTRAL US FRIDAY INTO SATURDAY...WITH WAA
AND DRY CONDITIONS EXPECTED. HIGHLY AMPLIFIED LONGWAVE UPPER LEVEL
TROUGH STILL EXPECTED TO DIG INTO THE DESERT SOUTHWEST
SATURDAY...WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE CENTRAL
US LATE SATURDAY NIGHT INTO SUNDAY. ALL MODELS EJECTING THIS SYSTEM
INTO THE WESTERN HIGH PLAINS BY SUNDAY AND SLOWLY MOVE IT EAST
NORTHEASTWARD INTO EARLY NEXT WEEK. THIS WILL SET UP A WET ACTIVE
PATTERN ACROSS THE REGION/STATE BY LATE SATURDAY NIGHT INTO EARLY
NEXT WEEK.
FINER DETAILS STILL TO BE DETERMINED WITH SOME UNCERTAINTY IN HOW
FAR THE SFC FRONT WILL PUSH NORTHWARD SUNDAY INTO MONDAY. FOR NOW
MODELS JUST BRING THE SFC FRONT INTO EXTREME SOUTHERN IOWA LATE
SUNDAY INTO MONDAY. INSTABILITY INCREASES ACROSS THE AREA WITH
STRONG PUSH OF MOISTURE NORTHWARD FROM THE GULF AND WAA ALOFT SHOULD
SEE DECENT CHANCE FOR THUNDER ACROSS THE ENTIRE CWA. AS SYSTEM
BECOMES MORE WRAPPED UP AND SLOWLY TRANSLATES EAST INTO LATE MONDAY
THROUGH WEDNESDAY...THREAT OF THUNDER DECREASES WITH MORE STRATIFORM
RAIN EXPECTED. AS THE UPPER LEVEL SYSTEM PUSHES EVER SLOW SLOWLY
EASTWARD...REGION SHOULD REMAIN UNDER THE INFLUENCE OF UPPER LEVEL
CYCLONIC FLOW THROUGH MUCH OF NEXT WEEK WITH A WET AND COOLER
PATTERN EXPECTED.
&&
.AVIATION...24/18Z
ISSUED AT 1240 PM CDT THU APR 24 2014
MVFR/IFR CIGS AND INTERMITTENT VIS WILL CONTINUE THROUGH 19-20Z
AS THE LOW PRESSURE MOVES NORTHEAST AND LIGHT PRECIP TAPERS OFF.
ANOTHER BATCH OF RAIN/TSTMS MOVING NORTHEAST FROM MISSOURI LOOKS
TO MAINLY AFFECT OTM AND POSSIBLY DSM FOR A SHORT TIME. CAA
DEVELOPS THIS AFTERNOON BEHIND THE LOW AND KEPT MVFR CIGS INTO
TONIGHT FOR MUCH OF THE TAF SITES.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS PADUCAH KY
320 PM CDT Thu Apr 24 2014
.SHORT TERM...(Tonight through Saturday night)
Issued at 320 PM CDT THU APR 24 2014
Finally have some lower 50s surface dewpoints spreading into
southeast Missouri as of 19Z. It has taken most of the day, but
mid to upper 50 dewpoints seem reasonable for much of the area
ahead of the storms late this afternoon and this evening.
Instability is still meager at best, and the forcing associated
with the mid/upper-level trough will be the main instigating
factor for this event.
The HRRR has been fairly consistent through the day at bringing
the first of the showers and storms into Ripley and Carter
counties around 22Z, and to the Mississippi River by 00Z. It
appears as though the convection will become more organized as it
moves east over the remainder of the region through 06Z.
Model soundings indicate impressive 0-3KM SRH values, certainly
enough to support rotating updrafts, but the forcing is likely to
result in a linear event. So, would expect wind damage to be the
main concern with some minor potential for a brief tornado or two
with mesovortices or embedded supercell structures. Not sure just
how much severe weather there will be, given the struggling
moisture and instability. This may result in a better severe
threat across southeast Missouri and west Kentucky, where the
better low-level moisture will be located.
The 12Z models are in reasonable agreement that there will be some
wrap-around showers late tonight across the northeast half of the
area, as the main mid/upper trough moves through the region. The
showers may last through sunrise, especially in the Owensboro
area. Increased Pops to likely levels for this activity.
The 12Z models leave little to debate for Friday through Saturday,
but they do diverge a bit in the location of the weak frontal
boundary by 12Z Sunday. The GFS brings the boundary into the Tri
State area, while the NAM keeps it northeast of the area. It
basically stalls out, and takes on the look of a warm front, and
the models are dry through 12Z Sunday, so it will not make much
difference.
As for temperatures, will lean to the warm side of guidance for
lows tonight through Saturday night, and for highs on Saturday.
Guidance has cooled things down a few degrees for highs Friday, so
decided to blend the consensus of 12Z guidance with the previous
forecast.
.LONG TERM...(Sunday through Thursday)
Issued at 320 PM CDT THU APR 24 2014
During the day Sun, a large scale, deep low pressure system will
approach the PAH forecast area from the west, as agreed on by the
GFS/ECMWF ensemble means. Individual deterministic runs of the med
range models began to differ with the details after Mon (Day 6), but
agreement on the mid level and sfc features was not bad for that
time frame.
Some time on Sun morning, a warm front ahead of the system will
begin its trek nwd across the region. This, combined with divergence
aloft, deep moisture advection and instability, will result in
plentiful tstm activity west of the MS River, and scattered tstms
east of the MS River. Sun night/Mon/Mon night, showers will be
nearly a sure thing, with the best chance of tstms during the day
time hours. Due to multiple rounds of deep moist convection, and the
slower movement of the overall system, heavy rainfall amounts are
possible. Wind shear increases aloft Mon, and with available
instability, severe weather is possible into the evening.
From Tue through Wed night, pcpn chances are forecast to gradually
wane as the nearly stacked low pressure system wobbles through the
Midwest. The last signal for instability tstms appeared to be Tue.
There could be a resurgence of showers Thu as energy wraps around
the back side of the vast mid/upper low, as it possibly begins to
depart.
&&
.AVIATION...
Issued at 1252 PM CDT THU APR 24 2014
VFR conditions are expected this afternoon with just a few cu
around 5kft expected around KCGI late this afternoon. Used a 2 to 3
hour TEMPO group to time the main line of thunderstorms through
the area this evening and tonight. As the line gets more organized
with time this evening, the thunder potential may linger awhile
longer at KEVV and KOWB. Also the models are indicating more in
the way of wrap-around showers lingering potentially past 12Z at
KEVV and KOWB. Not sure if visibilities will drop to MVFR levels,
but ceilings will certainly be there through daybreak, and IFR
ceilings are likely at least for part of that time.
Scattering/clearing is expected in the east by late morning.
Winds will increase and become gusty from the south or south
southeast this afternoon and evening, and then veer to southwest
behind the main line of convection. Gusts into the mid 20kts can
be expected in the western half of the area this afternoon. They
will eventually veer to the west northwest Friday morning, as the
whole storm system moves east of our area. Some gusts into the
teens will be possible Friday morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...DB
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
320 PM EDT Thu Apr 24 2014
.SHORT TERM (Now through Friday Night)...
Issued at 310 PM EDT Thu Apr 24 2014
In the near term, afternoon visible satellite imagery shows high
level cirrus clouds progressing northeast across central KY and
southern IN, in advance of a shortwave to our west, with surface
temperatures warming steadily to near 70 east and lower and mid 70s
west. Temperatures will continue to rise a couple/few more degrees
through late afternoon before falling back this evening.
Pronounced shortwave over KS/OK at this time will move steadily east
tonight accompanied by an increase in low-level moisture and
southerly winds, which will effectively limit/end our evening fall
in surface temperatures overnight. Surface winds should become gusty
overnight. Currently, this system is causing widespread convective
development from western MO to eastern OK and AR. Models are in good
agreement bringing these storms in a band into central KY and
southern IN late this evening and overnight. The 15z HRRR and 12z
in-house mesoscale models bring the leading edge of the convection
to our western forecast area border around 04 UTC.
Looking at model soundings, boundary layer cools this evening but
steep lapse rates and elevated instability remain if lifting a
parcel from about 900-950 mb. This will support continuation of
convection as axis of precipitation moves across our area,
especially western part of forecast area. With increasing winds at
925 and 850 mb, there is a chance that greater momentum air could
mix down to surface and create a few strong wind gusts with the
strongest cells (again, more likely in western sections), but
presence of weak-to-moderate nocturnal boundary layer inversion
should keep strongest winds aloft, unable to penetrate to surface.
After this band passes, there could be a brief lull in precip, but
models bring another area of moisture through from early to mid
morning (from west to east) associated with the actual mid-level
trough axis and surface front. As a result, additional scattered
showers and thunderstorms are expected during that time, with models
again indicating presence of some instability.
Front passes through the area first half of Friday. Winds behind the
boundary will become quite gusty from the west-northwest around 30
mph. Morning clouds and lingering showers will move off to the east
followed quickly by a clearing trend. Highs Friday afternoon should
be in the upper 60s and lower 70s, depending on how rapdily skies
clear. Friday night will be mainly clear with lows again down in the
40s in most locations.
.LONG TERM (Saturday through Thursday)...
Issued at 318 PM EDT Thu Apr 24 2014
Saturday - Sunday...
Heights will rise through the weekend as a progressive upper ridge
axis approaches and then slides through. Meanwhile, a cold front
will sag southward across southern Ohio and into central IN,
stalling by Saturday evening as it becomes parallel to the upper
level flow. Technically, it would be a back door cold front if it
were to make progress through the area, but it looks to stall just
to our north. Either way, the boundary will be moisture starved and
we should stay on the warm side of it. This will lead to a dry and
warm weekend. Expect highs on Saturday in the upper 70s north to low
80s south. Lows Saturday night should dip into the lower 50s. Should
start to see an gradual increase in mid and upper level clouds on
Sunday as the ridge axis starts to slide east, however 1000-850
thicknesses and 850 mb temps will support a 2-3 degree increase from
Saturday. Therefore, have gone with mostly lower 80s on Sunday. A
few Bluegrass or southern IN counties may stay confined to upper 70s.
Will continue to leave the slightest of chances for a shower or
storm in our far western tier or two of counties late Sunday
afternoon, however bulk of precip will not arrive until Sunday night
onward.
Sunday Night - Tuesday...
By Sunday night, blocking upper ridge axis will be off to our east
with an impressive closed upper low over the central Plains.
Southwesterly flow through a deep layer will overspread the Ohio
Valley, including a 40 knot low level jet nosing in. The quasi-
stationary frontal boundary will be just off to our northeast with
expansive mid level deformation aloft. By dawn on Monday, expect
scattered to numerous showers and a few t-storms mainly along and
west of I-65. These likely shower and t-storm chances will then
encompass the entire CWA on Monday. Tough to tell how well we
destabilize in this environment, but it appears that a stronger to
possibly severe storm threat will be conditional upon
destabilization, especially along and west of I-65.
Another threat of stronger to severe storms may move in later Monday
night into early Tuesday as the exit region of another impulse
rotating around the upper low ejects out of the southern Plains.
Again, strength of storms would be conditional upon destabilization.
Scattered to numerous showers and storms could then plague the area
again later Tuesday afternoon/evening.
Will continue to monitor threat for stronger storms to start the new
work week, but will also keep an eye on the threat for periods of
heavy rain and flooding. With repeated rounds of t-storms possible
and PWATs jumping up around 2 standard deviations above normal
for this time of year, flooding could become a concern. Tough to
judge temperatures during this time, solid reading in the 70s seem
reasonable each day on the warm side of the boundary and warm
advective flow. Obviously, convection will be the deciding factor.
Lows will be mild during this time, at least in the low 60s in
most spots.
Tuesday Night - Thursday...
We begin to transition to a cooler period by the middle and end of
the week as the wobbling upper low and its associated surface
reflection slide into the Midwest. Precipitation chances look to
become more scattered in nature during this time with thunder
chances becoming less likely. These days will likely not be
wash-outs, but will be mostly cloudy and considerably cooler. Look
for highs Wednesday and Thursday in the 50s and lows in the low and
mid 40s by Wednesday night.
&&
.AVIATION (18Z TAF Update)...
Issued at 130 PM EDT Thu Apr 24 2014
In the near term through this evening, VFR conditions will prevail
at all 3 TAF sites, with a southeast surface wind becoming south at
5 to 15 mph. Tonight, a strong shortwave trough will progress
eastward across the Ohio Valley, accompanied by a band or 2 of
showers and thunderstorms. Low-level wind fields will increase from
the south with surface gusts over 20 kts at times late tonight.
Winds at 850 mb may increase to around 50 kts, but winds will
increase steadily from the surface to 850 mb with no abrupt change
in wind direction, i.e., strong low-level/sudden wind shear should
not be a significant concern.
A band of convection should reach SDF and BWG in the 04-06z time
frame or so, and then just thereafter at LEX. Convective cells would
be more likely at BWG and SDF, and then more scattered within a band
of showers at LEX as the line moves east. This should take vsbys
and/or ceilings into MVFR category as predominant. After this axis
of rain moves through, there may be a break of precipitation with a
return mainly to VFR. But then scattered thunderstorms are again
possible a couple/few hours either side of 12z as the surface front
and mid-level trough pass through the TAF sites. Have accounted for
this with VCTS in the grids.
After frontal passage Friday morning, winds will become west to
northwest and gust from 20-30 kts at times. Low clouds will also
clear during the day.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........BJS
Aviation..........TWF
AREA FORECAST DISCUSSION
NWS JACKSON MS
314 PM CDT THU APR 24 2014
.DISCUSSION...
TODAY THROUGH SATURDAY
STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING
ACROSS THE DELTA REGION AND EASTWARD ALONG THE HIGHWAY 82 CORRIDOR.
ONCE THE BOUNDARY MOVES THROUGH FRIDAY MORNING, EXPECT A DRYING AND
WARMING TREND INTO THE FIRST HALF OF THE WEEKEND. PLEASE SEE LONG
TERM AS CONFIDENCE CONTINUES TO GROW ON A SIGNIFICANT SEVERE WEATHER
EPISODE WITH MULTIPLE ROUNDS OF SEVERE WEATHER SUNDAY AFTN THROUGH
TUESDAY.
STRONG TO SEVERE STORMS HAVE ALREADY BEGUN TO FIRE THIS AFTERNOON IN
LA AND AR IN ASSOCIATION WITH A SHARP S/WV TROUGH AND ALONG A
PREFRONTAL PRESSURE TROUGH WHERE SBCAPE VALUES HAVE BUILT INTO THE
1500-2000 J/KG RANGE. THIS INSTABILITY IN COMBINATION WITH 40-50 KT
DEEP LAYER SHEAR AND NEAR 8 C/KM H7-H5 LAPSE RATES WILL FURTHER
SUPPORT A SEVERE WEATHER RISK GOING INTO THE ARKLAMISS DELTA
COUNTIES LATE THIS AFTN AND EVENING. DAMAGING WINDS OF 60 MPH AND
HAIL TO SIZE OF HALF DOLLARS LOOK TO MAIN HAZARDS AT THIS TIME. SPC
MESOANALYSIS CURRENTLY DEPICTS LESS THEN 100 M2/S2 0-1KM SRH WITHIN
SURFACE BASED CONVECTIVE AREA. THIS, IN CONJUNCTION WITH HIGHER
LCL/LFCS ALONG AND EAST OF THE DELTA SHOULD LIMIT TORNADO POTENTIAL.
HOWEVER, IT SHOULD BE NOTED THAT HRRR CONTINUES TO SHOW 0-1KM
HELICITY VALUES INCREASING TOWARDS 150-200 M2/S2 OVER THE DELTA AND
NORTH CENTRAL MS THROUGH THE EARLY EVENING AND THUS A NON-ZERO RISK
OF A TORNADO EXISTS. THE GOING GRAPHICS HANDLE THE OVERALL SITUATION
WELL.
INSTABILITY WILL DECREASE THROUGH THE NIGHT AFTER 1AM AS THE BROKEN
LINE SHIFTS EAST INTO LESS SUPPORTIVE THERMO ENVIRONMENT AND OVERALL
WEAKENING TREND SHOULD OCCUR AS A WEAK COOL FRONT MOVES THROUGH THE
REGION BY FRIDAY MORNING. A DRYING TREND WILL START FRIDAY AND GO
INTO SATURDAY WITH A WARMING TREND INTO THE EARLY WEEKEND. AFTER A
SLIGHTLY COOLER START TOMORROW MORNING HIGHS WILL REBOUND INTO THE
MID TO UPPER 70S FRI AFTN UNDER FULL SUN. HIGHS SATURDAY WILL REACH
INTO THE LOW TO MID 80S WITH SOME AREAS APPROACHING UPPER 80S.
A VOLATILE EPISODE OF SEVERE STORMS AND HEAVY RAIN CONTINUES TO LOOK
PROBABLE LATE WEEKEND INTO EARLY NEXT WEEK. PLEASE STAY UP TO DATE
ON THIS SITUATION. /ALLEN/
SUNDAY THROUGH NEXT WEDNESDAY...
FORECAST THINKING IS GENERALLY THE SAME REGARDING THE POTENT SET-
UP FOR SEVERE WEATHER AND HEAVY RAIN INDICATED BY GLOBAL MODEL
GUIDANCE FOR EARLY NEXT WEEK...PARTICULARLY FROM LATE SUNDAY THROUGH
MONDAY NIGHT...AND PERHAPS THROUGH TUESDAY INTO TUESDAY NIGHT. ALL
MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG TORNADOES
WILL BE POSSIBLE. SIGNIFICANT FLOODING COULD DEVELOP IF MULTIPLE
ROUNDS OF STORMS MATERIALIZE.
DRY WEATHER WILL CONTINUE THROUGH SATURDAY NIGHT OVER THE ARKLAMISS...
BUT DRAMATIC CHANGES ARE EXPECTED STARTING SUNDAY AFTERNOON AND GOING
THROUGH SUNDAY NIGHT AS A POWERFUL DEEPENING CYCLONE TRAVERSES THE
PLAINS STATES AND BRINGS RAPID PRESSURE FALLS TO THE LOWER MS VALLEY
REGION. A STRENGTHENING LOW LEVEL JET JUXTAPOSED BY STEEP MID LEVEL
LAPSE RATES WILL DRAW RICH GULF MOISTURE NORTHWARD (SFC DEWPOINTS
APPROACHING 70 F) AND INCREASE LOW LEVEL SHEAR AND TORNADO POTENTIAL
BY SUNDAY EVENING OVER THE DELTA REGION AS SFC- BASED THUNDERSTORMS
BREAK OUT. THE FIRST ROUND OF STORMS MAY ORGANIZE INTO A MESOSCALE
CONVECTIVE SYSTEM TAPPING INTO VERY MOIST AIR WITH PRECIPITABLE WATER
~ 1.75 INCHES. THIS MCS COULD PUSH ACROSS MUCH OF THE ARKLAMISS
OVERNIGHT BEFORE WEAKENING SOME AS IT OUTRUNS BETTER UPPER LEVEL
SUPPORT. HOWEVER...EXPECT RE-NEWED SEVERE THUNDERSTORM ACTIVITY
MONDAY AS THE NOSE OF POWERFUL PACIFIC JET ENERGY ROUNDS THE BASE OF
THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND SHEAR/LIFT AND THE
SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED LAYER CAPE > 3000
J/KG COULD HELP MAY FOR A VOLATILE SET-UP WITH THIS SYNOPTIC PATTERN.
CIPS ANALOGS ARE SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON TO
THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE...ESPECIALLY IF A SLOW-MOVING
CONVECTIVE SYSTEM SETS UP MONDAY NIGHT AS GUIDANCE SUGGESTS. ANOTHER
CONCERN IS THE POSSIBILITY FOR THE CYCLONIC REGIME TO STALL OVER THE
CENTRAL CONUS FOR A LONGER PERIOD INTO TUESDAY...ALLOWING ANOTHER LOBE
OF SHORTWAVE ENERGY TO MOVE ACROSS THE AREA AND BACK FLOW
SUFFICIENTLY FOR REGENERATION OF STORMS. BEYOND TUESDAY NIGHT...
EXPECT DRIER AND COOLER AIR TO FINALLY MOVE INTO THE REGION. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 59 81 52 87 / 17 5 0 5
MERIDIAN 60 82 48 86 / 22 5 0 5
VICKSBURG 57 81 53 86 / 23 5 0 5
HATTIESBURG 63 84 56 87 / 18 5 0 5
NATCHEZ 60 81 55 85 / 15 5 0 5
GREENVILLE 56 79 52 85 / 71 5 0 5
GREENWOOD 57 78 49 85 / 62 5 0 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/EC/BK
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1223 PM CDT Thu Apr 24 2014
.UPDATE:
Issued at 1029 AM CDT Thu Apr 24 2014
Based on latest radar/satellite data...adjusted temperatures
upwards a few degrees across the eastern half of the CWA while
trimming highs over portions of central and northeastern Missouri
where pre-frontal cloudiness and shra with embedded thunder is
moving in late this morning.
For this afternoon...not sure how unstable we will
get...especially for the northern half to two-thirds of the CWFA.
Aforementioned pre-frontal clouds/precipitation could really hamper
instability from rising later on this afternoon. HRRR/RAP really
suffering from warming warm sector way too much as hourly
temperatures even over central Missouri per these near-term models
would climb into the upper 70s and low 80s.
Consequently...developing way too much sfc-based instability. In
addition...stronger shear this afternoon/evening will be over
southeastern Missouri just to south of area so not sure degree of
strong/severe storms this far north. Regardless...very strong
forcing for ascent via strong DCPVA and jet coupling aloft should
produce a widespread shield of rain with embedded thunderstorms
along the front. Will montior situation throughout today and make
additional adjustments/changes to the forecast as necessary.
Gosselin
&&
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1216 PM CDT Thu Apr 24 2014
Round of pre-frontal precpitation beginning to affect KCOU and
should also affect KUIN with shra/embedded thunder possible.
Ceilings/visibilities may dip down into MVFR category early this
afternoon. Frontal timing a bit slower than earlier
forecast...around 2100 UTC at KCOU...2300 UTC at KUIN...and
0000-0200 UTC at metro TAF sites. More instability as you head
south...but round of thunderstorms expected at terminals with
brief periods of IFR visbys in heavy rain possible. Showers are
expected to linger behind front for a few hours. Winds will shift
to the northwest behind front with brief gusts along/just behind
front from 25-30 knots. Skies will quickly clear out overnight
tonight with winds backing to the west/southwest Friday.
Specifics for KSTL:
Round of pre-frontal is expected to weaken as it heads east toward
terminal so uncertain whether or not some light rain showers will
affect the site. Frontal timing a bit slower than earlier
forecast...around 0100 UTC. More instability as you head
south...but round of thunderstorms expected at terminal with
brief periods of IFR visbys in heavy rain possible. Showers are
expected to linger behind front for a few hours. Winds will shift
to the northwest behind front with brief gusts along/just behind
front from 25-30 knots. Skies will quickly clear out overnight
tonight with winds backing to the west/southwest Friday afternoon.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1200 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 936 AM CDT THU APR 24 2014
UPDATED FORECAST FOR MAINLY FIRE WEATHER ELEMENTS. BASED ON RAPID
CITYS UPPER AIR SOUNDING AND THE LATEST RAP MODEL...LOWERED
RELATIVE HUMIDITIES ACROSS MUCH OF THE AREA FOR TODAY. THE WINDS
LOOK TO BE ON TRACK FOR THE RED FLAG WARNING ALSO. HOWEVER...WINDS
MAY DROP OFF BY LATE AFTERNOON. UPDATED OTHER FIRE WEATHER
ELEMENTS BASED ON LATEST MODEL DATA INCLUDING HAINES...MIXING
HEIGHT...TRANSPORT WINDS...AND VENTILATION RATE/SMOKE DISPERSAL.
PUBLIC FORECAST WAS LARGELY UNCHANGED WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
POST FRONTAL SHOWERS CONTINUE OVER A SMALL PORTION OF SOUTHWEST
NEBRASKA AND NORTH CENTRAL NEBRASKA EARLY THIS MORNING. LAST
LIGHTNING WAS AROUND 05Z. FAIRLY STRONG NORTHWEST FLOW CONTINUING
OVER THE FORECAST AREA EARLY THIS MORNING. ALL SHOWERS SHOULD HAVE
CLEARED FORECAST AREA BY 12Z. BIG WINNERS TONIGHT WERE GARFIELD
AND WHEELER COUNTIES WITH LESS THAN A QUARTER OF AN INCH. THIS
WILL HAVE IMPLICATIONS WITH FIRE WEATHER...SEE DISCUSSION BELOW.
MODELS IN FAIR AGREEMENT THIS MORNING FOR THE NEAR TERM.
TEMPERATURES ABOUT 10F DEGREES COOLER TODAY ACROSS THE FORECAST
AREA. STRONG NORTHWEST FLOW TO CONTINUE OVER THE AREA AGAIN TODAY
WITH GOOD MIXING AND SKIES CLEARING OUT FROM THE PANHANDLE
EASTWARD THROUGH THE MORNING. MODELS HAVE CLOUDS CLEARING OUT
PRETTY QUICKLY BUT CURRENT TRENDS ON SATELLITE NOT SUPPORTIVE OF
THIS. FULL SUN EXPECTED BY THIS AFTERNOON...AND WITH GUSTY
NORTHWEST FLOW HAVE GONE A COUPLE OF DEGREES ABOVE GUIDANCE FOR
HIGHS. TONIGHT WITH CLEAR SKIES TEMPERATURES WILL FALL INTO THE
MID 30S TO AROUND 40. FRIDAY...AS WEAK RIDGE CONTINUES TO MOVE
EAST INTO THE NORTHERN PLAINS...EXPECT CONTINUED DRY AND WEAK
SOUTHWEST FLOW AS A WEAK SURFACE TROUGH TRANSITIONS TO THE EAST
ACROSS WESTERN NEBRASKA WITH A VERY DRY AIRMASS IN PLACE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE
PACIFIC COAST FRIDAY EVENING...AND PROGRESS EASTWARD INTO THE
CENTRAL PLAINS DURING THE WEEKEND. THE 24/00Z MODEL RUNS HAVE ALL
SHIFTED THE TRACK OF THE STORM NORTH...WITH A NEARLY STACKED H5/H7
CIRCULATION CENTER LOCATED INVOF NORTHEAST COLORADO OR WESTERN
NEBRASKA AT 00Z MONDAY 28TH APRIL. GEFS ALSO CLUSTERING A AN H5
CIRCULATION CENTER IN THE SAME AREA. OPERATIONAL MODELS AND THE GEFS
ALL INDICATE A VERY DEEP SURFACE LOW /NEAR 983MB/ IN THE SAME
GENERAL AREA. THIS WILL BE A VERY DYNAMIC SYSTEM...WITH UNMODIFIED
RICH GULF MOISTURE STREAMING NORTHWARD INTO THE PLAINS. THIS
SPELLS SEVERE THUNDERSTORMS AND HEAVY RAINFALL IN AREAS. THE
CAVEAT TO ALL OF THIS WILL BE A PRONOUNCED DRY SLOT...THAT WILL
IMPACT SOME PORTION OF THE CENTRAL PLAINS. WITH TONIGHTS NORTHWARD
SHIFT IN THE MODELS...THIS DRY SLOT WOULD IMPACT PART OR ALL OF
THE NWS NORTH PLATTE FORECAST AREA SOMETIME DURING THE WEEKEND. AT
THIS POINT HOWEVER...THE SYSTEM IS STILL WELL OFFSHORE AND NOT
BEING SAMPLED BY UPPER AIR OBSERVING NETWORK. THEREFORE AM
HESITANT TO MAKE MAJOR CHANGES TO THE CURRENT FORECAST. IF THE
MODELS CONTINUE TO FAVOR A NORTHWARD TRACK IN FUTURE RUNS...THEN
WILL HAVE TO WARM HIGHS AND CUT PRECIPITATION CHANCES FOR PART OF
THE WEEKEND.
EARLY NEXT WEEK...THE AREA WILL CONTINUE TO BE IMPACTED FROM THIS
LARGE SLOW MOVING STORM SYSTEM. HOW THIS WHOLE SYSTEM EVOLVES COULD
BE QUITE INTERESTING. FOR EXAMPLE...THE LATEST 24/00Z ECMWF DUMBBELLS
A SECOND UPPER LOW WESTWARD FROM EASTERN CANADA...EVENTUALLY MERGING
THE TWO SYSTEM TOGETHER LATE MONDAY INTO TUESDAY...SENDING A LARGE
SHIELD OF RAIN WEST ACROSS THE AREA. THIS IS JUST ONE POSSIBLE
SCENARIO. FOR NOW...HAVE LOW CONFIDENCE ON HOW THIS WILL ALL PAN
OUT...AND WILL KEEP A CHANCE FOR RAIN AND COOL TEMPERATURES GOING
THROUGH AT LEAST TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1200 PM CDT THU APR 24 2014
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES FOR THE NEXT 24
HOURS. GUSTY NORTHWEST WINDS WILL DIMINISH LATE THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 311 AM CDT THU APR 24 2014
HAVE ISSUED A RED FLAG WARNING FOR ALL OF WESTERN NEBRASKA THIS
AFTERNOON FOR LOW RELATIVE HUMIDITY AND WINDS. GARFIELD...WHEELER
AND SOUTHERN HOLT COUNTIES RECEIVED LESS THAN A QUARTER OF AN INCH
OF PRECIPITATION OVER NIGHT IN FIRE ZONE 209 BUT THE MAJORITY OF
THAT ZONE WAS TRACE AMOUNTS OR A HUNDREDTH OF AN INCH AT BEST. THE
REMAINDER OF WESTERN NEBRASKA SAW A HUNDREDTH OR LESS OF
PRECIPITATION. MINIMUM RELATIVE HUMIDITIES FELL INTO THE SINGLE
DIGITS AND TEENS YESTERDAY OVER MOST OF THE FORECAST AREA. THINGS
ARE STARTING TO GREEN UP BUT FUELS ARE STILL FAVORABLE. LOOKING TO
THE WEST ACROSS THE BORDER IN WYOMING VERY DRY AIR MASS UNDER THE
HIGH PRESSURE SYSTEM...WITH DEW POINTS IN THE SINGLE DIGITS AND
TEENS. STRONG NORTHWEST FLOW WILL DIMINISH ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON. WINDS SHOULD REMAIN
GUSTY TROUGH AT LEAST EARLY AFTERNOON HOWEVER. MINIMUM RH WILL
FALL INTO THE TEENS OVER THE ENTIRE FORECAST AREA AND MAY FALL
INTO THE SINGLE DIGITS OVER SOUTHWEST NEBRASKA AND THE SOUTHEAST
NEBRASKA PANHANDLE. ALL OF WESTERN NEBRASKA IN THE DAY 1 STORM
PREDICTION CENTER FIRE WEATHER OUTLOOK. FIRE WEATHER MAY BE A
CONCERN AGAIN ON FRIDAY WITH LOW RH BUT LIGHTER WINDS WILL BE
LIMITING FACTOR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ204-206-208>210-219.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...POWER
LONG TERM...TAYLOR
AVIATION...KNUTSVIG
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
337 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTH COUNTRY TONIGHT WILL RESULT IN
MAINLY CLEAR SKIES AND COOL TEMPERATURES. FRIDAY WILL START WITH
PLENTY OF SUNSHINE BUT CLOUDS WILL DEVELOP DURING THE AFTERNOON
HOURS WITH SHOWERS ARRIVING FOR FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WILL BE NEAR NORMAL FOR FRIDAY...BUT BELOW NORMAL
WITH CLOUDS AND SHOWERS ON SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 320 PM EDT THURSDAY...SFC HIGH PRES LOCATED OVER THE EASTERN GREAT
LAKES WL SHIFT INTO THE NORTH COUNTRY TONIGHT WITH CLRING SKIES
AND LIGHT TRRN DRIVEN WINDS DEVELOPING. RAP SOUNDINGS STILL SHOW
SOME ENHANCED RH AROUND 800MB...BUT THINKING ANY CLOUDS ASSOCIATED
WITH UPSLOPE FLW AND THIS MOISTURE WL QUICKLY DISSIPATE BY SUNSET.
GUIDANCE IS VERY COLD WITH SLK MAV/MET SHOWING READINGS OF
17/18...AND AROUND 29F FOR BTV. WL TREND A COUPLE DEGREES
HIGHER...BUT GIVEN VERY LOW SFC DWPTS AND LIGHT WINDS...THINKING
VALUES WL RANGE FROM THE UPPER 10S COLDER MTN VALLEYS/NEK TO M/U
20S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 320 PM EDT THURSDAY...MID/UPPER LVL RIDGE ACRS THE NE CONUS WL QUICKLY
SHIFT INTO EASTERN NEW ENGLAND BY 00Z SATURDAY...AS PROGRESSIVE
WESTERLY FLW ALOFT CONTS ACRS THE NORTHERN TIER OF THE UNITED
STATES. DEEP DRY LAYER AND STRONG SUBSIDENCE PER LATEST WATER
VAPOR TRENDS WL RESULT IN MOSTLY SUNNY SKIES ON FRIDAY
MORNING...BUT MID/UPPER LVL RH INCREASES AFT 18Z FROM SW TO NE.
BEST 850 TO 700MB OMEGA FIELDS AND ASSOCIATED RIBBON OF 850 TO
500MB RH >80% ARRIVES AFT 00Z SAT...SO WL KEEP FRIDAY DRY ATTM.
PROGGED 85H TEMPS RANGE FROM 0C NEK TO 4C SOUTHWEST
SLV...RESULTING IN TEMPS RANGING FROM THE L/M 50S NEK/MTNS TO L60S
SLV AND WARMER/UHI AREAS OF THE CPV.
FRIDAY NIGHT INTO SATURDAY...850 TO 500MB RH QUICKLY OVERSPREADS THE
FA WITH MODEST UVVS ASSOCIATED WITH 5H VORT AND DEVELOPMENT OF
MID/UPPER LVL TROF. STILL FEEL INITIAL 5H VORT AND MOISTURE WL
DISSIPATE ACRS OUR CWA ON FRIDAY NIGHT...WITH LEADING EDGE OF PRECIP
FALLING AS MOSTLY VIRGA...ESPECIALLY GIVEN VERY DRY LVLLS. BETTER
DYNAMICS AND DEEPER RH ARRIVES ASSOCIATED WITH CLOSED 5H/7H
CIRCULATION BTWN 06Z-12Z SATURDAY...WITH A BAND OF LIGHT TO MODERATE
RAIN ANTICIPATED. HAVE NOTED POCKETS OF COOLER PROGGED 85H TEMPS <0C
ACRS CENTRAL/NORTHERN VT/NEK ON SATURDAY MORNING...WHICH COULD
RESULT IN SOME WET SNOW IN THE MTN SUMMITS. COLD POOL ALOFT
ASSOCIATED WITH CLOSED SYSTEM MOVES DIRECTLY OVERHEAD ON
SATURDAY...WITH COOLING PROFILES ALOFT ANTICIPATED. THIS COMBINED
WITH SOME LIMITED SFC HEATING WL RESULT IN ADDITIONAL INSTABILITY
FOR MORE SCATTERED SHOWERS TO DEVELOP. BOTTOM LINE SAT WL BE COOL
AND DAMP WITH OCCASIONAL RAIN SHOWERS AND HIGH ELEVATION SNOW
SHOWERS LIKELY. TOTAL QPF WL RANGE BTWN 0.10 AND 0.50 OF AN INCH.
TEMPS WL RANGE FROM THE U30S/M40S NEK/MTNS TO M40S/L50S VALLEYS ON
SAT.
SATURDAY NIGHT...CLOSED MID/UPPER LVL CIRCULATION CONTS TO DEEPEN AS
SEVERAL EMBEDDED S/W`S INTERACT WITH THIS LARGE SYNOPTIC SCALE
SYSTEM. THIS WL SLOW OVERALL MOVEMENT OF SYSTEM DOWN WITH IT
BECOMING STATIONARY OFF THE NEW ENGLAND COASTLINE BY SAT NIGHT...AND
NUMEROUS RIBBONS OF MOISTURE ROTATING ACRS OUR CENTRAL/EASTERN CWA.
THIS COMBINED WITH DEVELOPING WEST TO NORTHWEST FLW WL RESULT IN
ADDITIONAL SHOWERS. GIVEN THE DEEPENING COLD POOL ALOFT AND
ASSOCIATED COOLING OF LLVL THERMAL PROFILES...THINKING SNOW LEVELS
WL DROP TO AROUND 2000 FT BY SUNDAY MORNING. HOWEVER...ACCUMULATIONS
SHOULD BE LIGHT. TEMPS WITH CLOUDS/WIND AND PRECIP WL HOLD MAINLY IN
THE 30S TO NEAR 40F...FAIRLY UNIFORMED ACRS OUR REGION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 336 PM EDT THURSDAY...EXTENDED RANGE FORECAST CONTINUES TO
LOOKS VERY UNCERTAIN AS MUCH OF THE CONUS WILL BE IMPACTED BY A
DEVELOPING OMEGA BLOCK LATE THIS WEEKEND. UPPER LOW LOW WHICH
WILL HAVE BROUGHT RAIN/SNOW SHOWERS TO THE REGION SATURDAY AND
SATURDAY NIGHT WILL SHIFT OFFSHORE SUNDAY WITH A GENERALLY DRY
YET COOL AND BRISK END TO THE WEEKEND. HIGHS WILL RUN ABOUT 5-10
DEGREES BELOW NORMAL IN THE MID 40S TO LOWER 50S. AS THE LOW
SHIFTS FURTHER OFFSHORE SUNDAY NIGHT...OMEGA BLOCK SETUPS UP
ACROSS THE CONUS WITH ANOTHER CLOSED LOW DEVELOPING OVER THE
CENTRAL ROCKIES AND A HIGHLY AMPLIFIED RIDGE ACROSS MUCH OF THE
EASTERN CONUS. THIS PATTERN REMAINS FAIRLY PERSISTENT FOR MONDAY
THROUGH WEDNESDAY WITH A SLOW PROGRESSION EASTWARD AND SOME
SLIGHT MODIFICATION TO THE AMPLITUDE OF THE RIDGE. AT THIS
TIME...THE FORECAST DOES LOOK GENERALLY DRY FOR THE NORTH
COUNTRY...BUT DEPENDING ON THE EXACT TRACK OF ALL THE ABOVE SAID
FEATURES...THINGS COULD CHANGE. TEMPS WILL BE HIGHLY VARIABLE
BASED ON RIDGE/LOW PLACEMENTS...BUT IN GENERAL LOOK TO RUN AT OR
BELOW NORMAL. AS WE GET CLOSER TO THURSDAY...SIGNS ARE THAT THE
RIDGE BEGINS TO BREAK DOWN AND ROCKIES LOW SHIFTS EASTWARD INTO
THE GREAT LAKES RENEWING CHANCES FOR PRECIP ACROSS THE NORTHEAST.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD. AS HIGH PRESSURE BUILDS INTO THE REGION THIS EVENING SCT-
BKN VFR DECK OVER NE VT WILL EVENTUALLY CLEAR OUT TO SKC AND GUSTY
NW WINDS ACROSS THE REGION WILL ABATE. EXPECT A PERIOD OF SKC ACROSS
THE ENTIRE REGION 00-06Z...THEN MID/HIGH CLOUDS AT 10-15KFT MOVE
IN FROM THE WEST IN ADVANCE OF OUR NEXT SYSTEM.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
18Z FRI THRU 00Z SAT...VFR WITH CIGS SLOWLY LOWERING TO NEAR 5KFT.
00Z SAT THRU 00Z MON...MIX OF MVFR/VFR WITH PERIODS OF SHOWERS
ASSOCIATED WITH UPPER LOW PASSAGE.
00Z MON THRU 00Z TUE...MVFR TRENDING TO VFR AS UPPER LOW PULLS
AWAY FROM THE REGION.
00Z TUE THRU 00Z WED...VFR UNDER HIGH PRESSURE.
&&
.FIRE WEATHER...
AS OF 930 AM EDT THURSDAY...RED FLAG WARNING CONTINUES UNTIL 7 PM
THIS EVENING FOR PARTS OF CENTRAL/SOUTHERN VT AND EASTERN ESSEX
COUNTY NY.
FIRE WEATHER CONCERNS CONTINUE THIS AFTERNOON FOR ELEVATIONS BELOW
1500 FEET ACROSS THE SOUTHERN CHAMPLAIN VALLEY...AND PORTIONS OF
SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT DRY
SPELL...EXPECTED GUSTY WINDS...AND LOW MIN RH VALUES.
MOST THE CPV AND SOUTHERN VERMONT HAVE SEEN LESS THAN A QUARTER
INCH OF RAINFALL IN THE PAST FIVE DAYS...THIS HAS RESULTED IN
SIGNIFICANT DRYING OF THE FINE FUELS PER LOCAL FOREST CONTACTS
BELOW 1500 FEET...WHERE GREEN UP HAS NOT OCCURRED.
MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE FUELS AND LEAF
LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL WET. MOST OF
CENTRAL/NORTHERN VT MTNS AND NORTHERN NY HAVE RECEIVED MEASURABLE
PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW PACK IS STILL ON THE
GROUND ABOVE 2000 FEET...RESULTING IN LIMITED THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 35
MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY THIS AFTN.
IN ADDITION...MIN AFTN RH VALUES WL DROP BTWN 20% AND 30% ACRS
NRN NY...THE CPV AND SOUTHERN VT.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL
WILL ALLOW ANY FIRES THAT DO OCCUR TO SPREAD QUICKLY...BURN
INTENSELY...AND BE DIFFICULT TO CONTAIN. PAY CLOSE ATTENTION TO
ANY OUTDOOR BURNING YOU MAY BE ATTEMPTING TODAY. MONITOR WEATHER
CONDITIONS...DO NOT LEAVE YOUR BRUSH OR DEBRIS PILE
UNATTENDED...AND HEED ANY ADVICE FROM YOUR LOCAL FIRE WARDEN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VTZ009>012.
NY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NYZ035.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LAHIFF
AVIATION...LAHIFF
FIRE WEATHER...TABER/KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
321 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTH COUNTRY TONIGHT WILL RESULT IN
MAINLY CLEAR SKIES AND COOL TEMPERATURES. FRIDAY WILL START WITH
PLENTY OF SUNSHINE BUT CLOUDS WILL DEVELOP DURING THE AFTERNOON
HOURS WITH SHOWERS ARRIVING FOR FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WILL BE NEAR NORMAL FOR FRIDAY...BUT BELOW NORMAL
WITH CLOUDS AND SHOWERS ON SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 320 PM EDT THURSDAY...SFC HIGH PRES LOCATED OVER THE EASTERN GREAT
LAKES WL SHIFT INTO THE NORTH COUNTRY TONIGHT WITH CLRING SKIES
AND LIGHT TRRN DRIVEN WINDS DEVELOPING. RAP SOUNDINGS STILL SHOW
SOME ENHANCED RH AROUND 800MB...BUT THINKING ANY CLOUDS ASSOCIATED
WITH UPSLOPE FLW AND THIS MOISTURE WL QUICKLY DISSIPATE BY SUNSET.
GUIDANCE IS VERY COLD WITH SLK MAV/MET SHOWING READINGS OF
17/18...AND AROUND 29F FOR BTV. WL TREND A COUPLE DEGREES
HIGHER...BUT GIVEN VERY LOW SFC DWPTS AND LIGHT WINDS...THINKING
VALUES WL RANGE FROM THE UPPER 10S COLDER MTN VALLEYS/NEK TO M/U
20S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 320 PM EDT THURSDAY...MID/UPPER LVL RIDGE ACRS THE NE CONUS WL QUICKLY
SHIFT INTO EASTERN NEW ENGLAND BY 00Z SATURDAY...AS PROGRESSIVE
WESTERLY FLW ALOFT CONTS ACRS THE NORTHERN TIER OF THE UNITED
STATES. DEEP DRY LAYER AND STRONG SUBSIDENCE PER LATEST WATER
VAPOR TRENDS WL RESULT IN MOSTLY SUNNY SKIES ON FRIDAY
MORNING...BUT MID/UPPER LVL RH INCREASES AFT 18Z FROM SW TO NE.
BEST 850 TO 700MB OMEGA FIELDS AND ASSOCIATED RIBBON OF 850 TO
500MB RH >80% ARRIVES AFT 00Z SAT...SO WL KEEP FRIDAY DRY ATTM.
PROGGED 85H TEMPS RANGE FROM 0C NEK TO 4C SOUTHWEST
SLV...RESULTING IN TEMPS RANGING FROM THE L/M 50S NEK/MTNS TO L60S
SLV AND WARMER/UHI AREAS OF THE CPV.
FRIDAY NIGHT INTO SATURDAY...850 TO 500MB RH QUICKLY OVERSPREADS THE
FA WITH MODEST UVVS ASSOCIATED WITH 5H VORT AND DEVELOPMENT OF
MID/UPPER LVL TROF. STILL FEEL INITIAL 5H VORT AND MOISTURE WL
DISSIPATE ACRS OUR CWA ON FRIDAY NIGHT...WITH LEADING EDGE OF PRECIP
FALLING AS MOSTLY VIRGA...ESPECIALLY GIVEN VERY DRY LVLLS. BETTER
DYNAMICS AND DEEPER RH ARRIVES ASSOCIATED WITH CLOSED 5H/7H
CIRCULATION BTWN 06Z-12Z SATURDAY...WITH A BAND OF LIGHT TO MODERATE
RAIN ANTICIPATED. HAVE NOTED POCKETS OF COOLER PROGGED 85H TEMPS <0C
ACRS CENTRAL/NORTHERN VT/NEK ON SATURDAY MORNING...WHICH COULD
RESULT IN SOME WET SNOW IN THE MTN SUMMITS. COLD POOL ALOFT
ASSOCIATED WITH CLOSED SYSTEM MOVES DIRECTLY OVERHEAD ON
SATURDAY...WITH COOLING PROFILES ALOFT ANTICIPATED. THIS COMBINED
WITH SOME LIMITED SFC HEATING WL RESULT IN ADDITIONAL INSTABILITY
FOR MORE SCATTERED SHOWERS TO DEVELOP. BOTTOM LINE SAT WL BE COOL
AND DAMP WITH OCCASIONAL RAIN SHOWERS AND HIGH ELEVATION SNOW
SHOWERS LIKELY. TOTAL QPF WL RANGE BTWN 0.10 AND 0.50 OF AN INCH.
TEMPS WL RANGE FROM THE U30S/M40S NEK/MTNS TO M40S/L50S VALLEYS ON
SAT.
SATURDAY NIGHT...CLOSED MID/UPPER LVL CIRCULATION CONTS TO DEEPEN AS
SEVERAL EMBEDDED S/W`S INTERACT WITH THIS LARGE SYNOPTIC SCALE
SYSTEM. THIS WL SLOW OVERALL MOVEMENT OF SYSTEM DOWN WITH IT
BECOMING STATIONARY OFF THE NEW ENGLAND COASTLINE BY SAT NIGHT...AND
NUMEROUS RIBBONS OF MOISTURE ROTATING ACRS OUR CENTRAL/EASTERN CWA.
THIS COMBINED WITH DEVELOPING WEST TO NORTHWEST FLW WL RESULT IN
ADDITIONAL SHOWERS. GIVEN THE DEEPENING COLD POOL ALOFT AND
ASSOCIATED COOLING OF LLVL THERMAL PROFILES...THINKING SNOW LEVELS
WL DROP TO AROUND 2000 FT BY SUNDAY MORNING. HOWEVER...ACCUMULATIONS
SHOULD BE LIGHT. TEMPS WITH CLOUDS/WIND AND PRECIP WL HOLD MAINLY IN
THE 30S TO NEAR 40F...FAIRLY UNIFORMED ACRS OUR REGION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 407 AM EDT THURSDAY...ECMWF AND GFS MODELS SHOW A CLOSED
UPPER LOW WILL BE OVER THE REGION SATURDAY NIGHT...SO WILL
CONTINUE WITH A CHANCE OF SHOWERS. THE CLOSED UPPER LOW WILL MOVE
EAST OF THE REGION BY SUNDAY...BUT THE FORECAST AREA WILL STILL
BE UNDER CYCLONIC FLOW...SO HAVE SLIGHT TO CHANCE POPS FOR
SHOWERS IN THE FORECAST FOR SUNDAY. EXPECTING MAINLY DRY
CONDITIONS SUNDAY NIGHT WITH JUST SOME SLIGHT CHANCE POPS FOR
SHOWERS OVER NORTHEAST VERMONT. A MAINLY DRY DAY ON MONDAY AS A
RIDGE OF HIGH PRESSURE BUILDS SOUTH FROM CANADA AND REMAINS OVER
THE REGION THROUGH MONDAY NIGHT.
ECMWF AND GFS MODELS SHOWING SOME MAJOR DIFFERENCES FOR THE
TUESDAY AND WEDNESDAY FORECAST. THUS...FORECASTER CONFIDENCE IS
LOW. ECMWF MODEL HAS A RIDGE OF HIGH PRESSURE AT THE SURFACE AND
ALOFT OVER THE REGION WITH A DRY FORECAST INDICATED FOR TUESDAY
AND WEDNESDAY... AS ECMWF MODEL SUGGESTING THE REGION WILL BE
UNDER AN OMEGA BLOCK WITH A CLOSED UPPER LOW OVER THE MID
MISSISSIPPI VALLEY WITH ANOTHER CLOSED UPPER LOW OVER THE
ATLANTIC SOUTH OF THE CANADIAN MARITIMES. HOWEVER...GFS MODEL
SHOWS A CLOSED UPPER LOW ALSO OVER THE MID MISSISSIPPI VALLEY
WITH THE OTHER CLOSED UPPER LOW MUCH FURTHER EAST IN THE ATLANTIC
THAN DEPICTED BY THE ECMWF MODEL. GFS MODEL BRINGS MOISTURE
NORTHEAST INTO THE REGION FROM THE SOUTHEASTERN U.S. TUESDAY AND
WEDNESDAY WITH A CHANCE OF SHOWERS. FOR NOW...WILL USE SUPER
BLEND POPS AND KEEP A CHANCE OF SHOWERS IN THE FORECAST FOR
TUESDAY AND WEDNESDAY...BUT GIVEN MODEL DIFFERENCES FORECASTER
CONFIDENCE IS LOW AT THIS TIME.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD. AS HIGH PRESSURE BUILDS INTO THE REGION THIS EVENING SCT-
BKN VFR DECK OVER NE VT WILL EVENTUALLY CLEAR OUT TO SKC AND GUSTY
NW WINDS ACROSS THE REGION WILL ABATE. EXPECT A PERIOD OF SKC ACROSS
THE ENTIRE REGION 00-06Z...THEN MID/HIGH CLOUDS AT 10-15KFT MOVE
IN FROM THE WEST IN ADVANCE OF OUR NEXT SYSTEM.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
18Z FRI THRU 00Z SAT...VFR WITH CIGS SLOWLY LOWERING TO NEAR 5KFT.
00Z SAT THRU 00Z MON...MIX OF MVFR/VFR WITH PERIODS OF SHOWERS
ASSOCIATED WITH UPPER LOW PASSAGE.
00Z MON THRU 00Z TUE...MVFR TRENDING TO VFR AS UPPER LOW PULLS
AWAY FROM THE REGION.
00Z TUE THRU 00Z WED...VFR UNDER HIGH PRESSURE.
&&
.FIRE WEATHER...
AS OF 930 AM EDT THURSDAY...RED FLAG WARNING CONTINUES UNTIL 7 PM
THIS EVENING FOR PARTS OF CENTRAL/SOUTHERN VT AND EASTERN ESSEX
COUNTY NY.
FIRE WEATHER CONCERNS CONTINUE THIS AFTERNOON FOR ELEVATIONS BELOW
1500 FEET ACROSS THE SOUTHERN CHAMPLAIN VALLEY...AND PORTIONS OF
SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT DRY
SPELL...EXPECTED GUSTY WINDS...AND LOW MIN RH VALUES.
MOST THE CPV AND SOUTHERN VERMONT HAVE SEEN LESS THAN A QUARTER
INCH OF RAINFALL IN THE PAST FIVE DAYS...THIS HAS RESULTED IN
SIGNIFICANT DRYING OF THE FINE FUELS PER LOCAL FOREST CONTACTS
BELOW 1500 FEET...WHERE GREEN UP HAS NOT OCCURRED.
MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE FUELS AND LEAF
LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL WET. MOST OF
CENTRAL/NORTHERN VT MTNS AND NORTHERN NY HAVE RECEIVED MEASURABLE
PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW PACK IS STILL ON THE
GROUND ABOVE 2000 FEET...RESULTING IN LIMITED THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 35
MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY THIS AFTN.
IN ADDITION...MIN AFTN RH VALUES WL DROP BTWN 20% AND 30% ACRS
NRN NY...THE CPV AND SOUTHERN VT.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL
WILL ALLOW ANY FIRES THAT DO OCCUR TO SPREAD QUICKLY...BURN
INTENSELY...AND BE DIFFICULT TO CONTAIN. PAY CLOSE ATTENTION TO
ANY OUTDOOR BURNING YOU MAY BE ATTEMPTING TODAY. MONITOR WEATHER
CONDITIONS...DO NOT LEAVE YOUR BRUSH OR DEBRIS PILE
UNATTENDED...AND HEED ANY ADVICE FROM YOUR LOCAL FIRE WARDEN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VTZ009>012.
NY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NYZ035.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...WGH
AVIATION...LAHIFF
FIRE WEATHER...TABER/KGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
556 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 549 PM CDT THU APR 24 2014
EARLY EVENING UPDATE FOR MINOR CHANGES TO POPS ACROSS THE EAST AND
TEMPERATURE TRENDS. ISOLATED PEA SIZE HAIL WILL REMAIN POSSIBLE
WITH A FEW STORMS OVER THE NEXT HOUR OR SO BEFORE THE CONVECTION
MOVES EAST AND DISSIPATES. EXPECTING FOG AGAIN OVERNIGHT...MAINLY
ALONG THE EASTERN FRINGE OF THE FORECAST AREA...FROM THE TURTLE
MOUNTAINS THROUGH THE JAMES RIVER VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP NORTH
CENTRAL NORTH DAKOTA THIS AFTERNOON. THE CURRENT AREA OF CONVECTION
IS IN AN ENVIRONMENT CHARACTERIZED BY 400 J/KG OF CAPE AND VERY
LITTLE WIND SHEAR. THEREFORE...THESE STORMS SHOULD REMAIN BELOW
SEVERE LIMITS. HOWEVER...SPC`S NON-SUPERCELL TORNADO PARAMETER
INDICATES THE POSSIBILITY OF COLD AIR FUNNELS OVER BOTTINEAU AND
MCHENRY COUNTIES. WOULD NOT BE SURPRISED TO GET FUNNEL CLOUD
REPORTS FROM THOSE AREAS IN THE NEXT HOUR OR SO. SCATTERED
SHOWERS ARE BEGINNING TO DEVELOP OVER NORTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA AS INSTABILITY INCREASES THIS AFTERNOON.
AFTER SUNSET...THE BOUNDARY LAYER SHOULD BEGIN TO STABILIZE AND
CONVECTIVE ACTIVITY SHOULD BEGIN TO WANE. VERY WEAK GRADIENT FLOW
ACROSS THE STATE SHOULD ALLOW FOR TEMPERATURES TO RADIATE INTO THE
30S. FURTHERMORE...THE LATEST HRRR AND RAP PROG FOG DEVELOPMENT FROM
THE TURTLE MOUNTAINS SOUTH THROUGH THE JAMES RIVER BASIN AFTER
MIDNIGHT. FOR NOW INDICATED PATCHY/AREAS OF FOG FOR SAID REGION
DURING THE 09Z-15Z FRIDAY PERIOD.
WEAK GRADIENT FLOW IS PROGGED TO CONTINUE FRIDAY. ANOTHER ROUND OF
INCREASING INSTABILITY IS FORECAST TO DEVELOP FRIDAY AFTERNOON.
HOWEVER...IT SHOULD NOT BE AS MUCH AS IS BEING OBSERVED THIS
AFTERNOON. WIND SHEAR WILL BE A LITTLE STRONGER FRIDAY AFTERNOON.
THE FAVORED AREA FOR CONVECTIVE DEVELOPMENT WILL BE OVER NORTHERN
NORTH DAKOTA. CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS
THERE FRIDAY AFTERNOON AS A RESULT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
A WET AND MUCH COOLER WEATHER PATTERN EVOLVES THROUGH THE LONG TERM
PERIOD. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LOCATED NEAR 142W/43N
WITH AN UPSTREAM 300MB JET STREAK OF 160KT DIGGING THE SHORTWAVE
TROUGH SOUTHEAST WITH TIME. GOOD AGREEMENT AMONGST THE LONG TERM
MODELS WITH A SPLITTING TROUGH DEVELOPING ALONG THE WEST COAST BY
SATURDAY...AND THE SOUTHERN PORTION OF THE AFOREMENTIONED UPPER JET
AND SHORTWAVE TROUGH DEVELOPING INTO AN UPPER LOW OVER SOUTHWEST
CALIFORNIA. THIS LOW IS FORECAST TO CLOSE OFF OFF NEAR COLORADO
SUNDAY...THEN CIRCULATE INTO THE CENTRAL PLAINS AND UPPER MIDWEST
MONDAY THROUGH THURSDAY. THIS RESULTS IN PLENTY OF MOISTURE THIS
WEEKEND INTO EARLY NEXT WEEK WITH A COOLING TREND.
FOR FRIDAY NIGHT...700MB RIDGE AXIS SHIFTS EAST...STRETCHING FROM
NORTHERN NORTH DAKOTA INTO MINNESOTA. SOUTHWEST FLOW WITH SEVERAL
EMBEDDED SHORTWAVES APPROACH AND MOVE INTO WESTERN AND CENTRAL NORTH
DAKOTA. THIS WILL ALLOW RAIN TO DEVELOP WEST AND WEST CENTRAL NORTH
DAKOTA.
SATURDAY THROUGH TUESDAY...A MORE SOUTHERLY FLOW SETS UP AS THE
AFOREMENTIONED UPPER LOW DEVELOPS AND MOVES INTO THE CENTRAL PLAINS.
MID LEVEL SHORTWAVES WILL CONTINUE TO ALLOW FOR SUFFICIENT LIFT WITH
MOISTURE ALREADY IN PLACE. HAVE MAINTAINED A SLIGHT CHANCE OF
THUNDERSTORMS SATURDAY AFTERNOON. A MUCH WETTER SYSTEM ARRIVES
SUNDAY INTO MONDAY...AS THE MAIN UPPER CLOSED LOW AND ASSOCIATED
SURFACE LOW WITH AN INVERTED TROUGH IMPINGE INTO WESTERN AND CENTRAL
NORTH DAKOTA. THE RESULT WILL BE FOR SEVERAL PERIODS OF WIDESPREAD
RAINFALL. HIGH TEMPERATURES SUNDAY INTO TUESDAY WILL REMAIN IN THE
40S OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA.
FOR TUESDAY NIGHT THROUGH THURSDAY...AREAL COVERAGE OF SHOWERS WILL
DIMINISH TUESDAY NIGHT/WEDNESDAY...WITH DRY WEATHER FORECAST FOR
THURSDAY. HIGH TEMPERATURES WILL SLOWLY RISE INTO THE 50S BY
THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 549 PM CDT THU APR 24 2014
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD END NEAR KJMS AROUND 01Z
THIS EVENING. EXPECTING MVFR FOG DEVELOPMENT AGAIN OVERNIGHT AT
KJMS...AND POSSIBLY KMOT. OTHERWISE...VFR CONDITIONS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...TM
LONG TERM...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 PM CDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP NORTH
CENTRAL NORTH DAKOTA THIS AFTERNOON. THE CURRENT AREA OF CONVECTION
IS IN AN ENVIRONMENT CHARACTERIZED BY 400 J/KG OF CAPE AND VERY
LITTLE WIND SHEAR. THEREFORE...THESE STORMS SHOULD REMAIN BELOW
SEVERE LIMITS. HOWEVER...SPC`S NON-SUPERCELL TORNADO PARAMETER
INDICATES THE POSSIBILITY OF COLD AIR FUNNELS OVER BOTTINEAU AND
MCHENRY COUNTIES. WOULD NOT BE SURPRISED TO GET FUNNEL CLOUD
REPORTS FROM THOSE AREAS IN THE NEXT HOUR OR SO. SCATTERED
SHOWERS ARE BEGINNING TO DEVELOP OVER NORTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA AS INSTABILITY INCREASES THIS AFTERNOON.
AFTER SUNSET...THE BOUNDARY LAYER SHOULD BEGIN TO STABILIZE AND
CONVECTIVE ACTIVITY SHOULD BEGIN TO WANE. VERY WEAK GRADIENT FLOW
ACROSS THE STATE SHOULD ALLOW FOR TEMPERATURES TO RADIATE INTO THE
30S. FURTHERMORE...THE LATEST HRRR AND RAP PROG FOG DEVELOPMENT FROM
THE TURTLE MOUNTAINS SOUTH THROUGH THE JAMES RIVER BASIN AFTER
MIDNIGHT. FOR NOW INDICATED PATCHY/AREAS OF FOG FOR SAID REGION
DURING THE 09Z-15Z FRIDAY PERIOD.
WEAK GRADIENT FLOW IS PROGGED TO CONTINUE FRIDAY. ANOTHER ROUND OF
INCREASING INSTABILITY IS FORECAST TO DEVELOP FRIDAY AFTERNOON.
HOWEVER...IT SHOULD NOT BE AS MUCH AS IS BEING OBSERVED THIS
AFTERNOON. WIND SHEAR WILL BE A LITTLE STRONGER FRIDAY AFTERNOON.
THE FAVORED AREA FOR CONVECTIVE DEVELOPMENT WILL BE OVER NORTHERN
NORTH DAKOTA. CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS
THERE FRIDAY AFTERNOON AS A RESULT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
A WET AND MUCH COOLER WEATHER PATTERN EVOLVES THROUGH THE LONG TERM
PERIOD. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LOCATED NEAR 142W/43N
WITH AN UPSTREAM 300MB JET STREAK OF 160KT DIGGING THE SHORTWAVE
TROUGH SOUTHEAST WITH TIME. GOOD AGREEMENT AMONGST THE LONG TERM
MODELS WITH A SPLITTING TROUGH DEVELOPING ALONG THE WEST COAST BY
SATURDAY...AND THE SOUTHERN PORTION OF THE AFOREMENTIONED UPPER JET
AND SHORTWAVE TROUGH DEVELOPING INTO AN UPPER LOW OVER SOUTHWEST
CALIFORNIA. THIS LOW IS FORECAST TO CLOSE OFF OFF NEAR COLORADO
SUNDAY...THEN CIRCULATE INTO THE CENTRAL PLAINS AND UPPER MIDWEST
MONDAY THROUGH THURSDAY. THIS RESULTS IN PLENTY OF MOISTURE THIS
WEEKEND INTO EARLY NEXT WEEK WITH A COOLING TREND.
FOR FRIDAY NIGHT...700MB RIDGE AXIS SHIFTS EAST...STRETCHING FROM
NORTHERN NORTH DAKOTA INTO MINNESOTA. SOUTHWEST FLOW WITH SEVERAL
EMBEDDED SHORTWAVES APPROACH AND MOVE INTO WESTERN AND CENTRAL NORTH
DAKOTA. THIS WILL ALLOW RAIN TO DEVELOP WEST AND WEST CENTRAL NORTH
DAKOTA.
SATURDAY THROUGH TUESDAY...A MORE SOUTHERLY FLOW SETS UP AS THE
AFOREMENTIONED UPPER LOW DEVELOPS AND MOVES INTO THE CENTRAL PLAINS.
MID LEVEL SHORTWAVES WILL CONTINUE TO ALLOW FOR SUFFICIENT LIFT WITH
MOISTURE ALREADY IN PLACE. HAVE MAINTAINED A SLIGHT CHANCE OF
THUNDERSTORMS SATURDAY AFTERNOON. A MUCH WETTER SYSTEM ARRIVES
SUNDAY INTO MONDAY...AS THE MAIN UPPER CLOSED LOW AND ASSOCIATED
SURFACE LOW WITH AN INVERTED TROUGH IMPINGE INTO WESTERN AND CENTRAL
NORTH DAKOTA. THE RESULT WILL BE FOR SEVERAL PERIODS OF WIDESPREAD
RAINFALL. HIGH TEMPERATURES SUNDAY INTO TUESDAY WILL REMAIN IN THE
40S OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA.
FOR TUESDAY NIGHT THROUGH THURSDAY...AREAL COVERAGE OF SHOWERS WILL
DIMINISH TUESDAY NIGHT/WEDNESDAY...WITH DRY WEATHER FORECAST FOR
THURSDAY. HIGH TEMPERATURES WILL SLOWLY RISE INTO THE 50S BY
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1251 PM CDT THU APR 24 2014
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. TEMPO MVFR CONDITIONS IN ISOLATED
THUNDERSTORMS WILL BE POSSIBLE OVER KMOT THIS AFTERNOON.
HOWEVER...AVIATION IMPACTS SHOULD BE MINIMAL AND BRIEF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TM
LONG TERM...KS
AVIATION...TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
116 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 111 PM CDT THU APR 24 2014
12Z NCEP MODELS AND LATEST RAP/HRRR STILL FOCUS A NARROW RIBBON OF
700 J/KG AND SHOWWALTERS -3C ALONG WITH NON-SUPERCELL TSTM
PARAMETERS OF GREATER THAN 2 IN AN AXIS FROM ROLLA THROUGH DEVILS
LAKE TO BTWN VALLEY CITY-FARGO TO JUST WEST OF WAHPETON. HOWEVER
CURRENT SPC MESO PAGE HAS NR 1000 MOST UNSTABLE CAPE IN SOUTHEAST
SASK AND STORMS ARE IN THAT AREA WITH SOME CAPE INTO FAR NW ND AND
A FEW ECHOES INTO THAT AREA. LATEST HRRR INDICATE STORMS IN THE
TURTLE MOUNTAIN REGION DEVELOPING SOUTHEAST ALONG AXIS MENTIONED
ABOVE IN THAT 21Z-01Z PERIOD. OTHER THAN THAT AREA OF SOLID RAIN
IN MINNESOTA WILL CONTINUE TO MOVE NORTH AND SLOWLY TAPER OFF IN
FAR WRN MN DURING THE AFTN. TIGHT TEMP GRADIENT WITH UPR 30S-LOW
40S EAST AND 50S WEST. REPORT OF WET SNOW MIXED WITH RAIN IN OTTER
TAIL COUNTY MN JUST BEFORE NOON IN POCKET OF HEAVIER PCPN. DONT
THINK THIS WILL LAST LONG UNLIKE LAST EVE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM CDT THU APR 24 2014
MANY CHALLENGES THROUGH THE SHORT AND INTO THE LONG TERM AS ACTIVE
AND AT TIMES COMPLEX PATTERN CONTINUES. CONSIDERING ACTIVE PATTERN
MODELS IN PRETTY GOOD AGREEMENT.
INTERESTING DAY AHEAD WITH TEMPERATURES...RAIN...THUNDERSTORM AND
ACCUMULATING SNOW POTENTIAL ALL CONTRIBUTING TO CHALLENGING
FORECAST. SUBSIDENCE IN THE WAKE OF SHORTWAVE LIFTING INTO CANADA
HAS DIMINISHED SHOWERS IN THE NEAR TERM. HOWEVER ELEVATED BOUNDARY
OVER THE CENTRAL DAKOTAS WILL PROPAGATE EAST ACROSS FA ALONG WITH
BAND OF FRONTOGENETIC FORCING AND WARM ADVECTION. GLOBAL AND
MESOSCALE MODELS ALL SUPPORT SHOWERS BECOMING MORE ORGANIZED FROM
VALLEY EAST THIS MORNING. PCPN AREA WILL THEN SHIFT EAST MAINLY ACROSS
WESTERN MN. IN THE WAKE OF THIS ELEVATED TROUGH DRYING WILL MOVE
INTO AREAS MAINLY WEST OF THE VALLEY AND COULD SEE SOME SOLAR
THERE WHICH WOULD HELP BOOST TEMPERATURES CLOSE TO AVERAGE WHERE
AREAS IN THE RAIN WILL LIKELY HOLD IN THE 40S. IN THE MEAN TIME
UPPER LOW AND ASSOCIATED COLD POOL WILL PROPAGATE SE REACHING FA
AT PRIME HEATING. WITH COLD POOL WILL SEE SOME PRETTY STEEP LAPSE
RATES ALONG WITH SUFFICIENT INSTABILITY AND AROUND 400J/KG OF
MIXED LAYER CAPE. ASSOCIATED SURFACE LOW WILL ALSO BE OVER FA AT
SAME TIME PROVIDING LOW LEVEL CONVERGENCE. SO EVEN WITH DRYING
ALLOWING PRECIPITABLE H2O VALUES TO DROP TO AROUND A HALF INCH
THERE WILL BE POTENTIAL FOR THUNDERSTORM DEVELOPMENT. WITH UPPER
AND SURFACE LOW OVER FA CANNOT RULE OUT POTENTIAL FOR A FEW SPIN-
UPS UNDER STRONGER STORMS.
TONIGHT COULD CONTINUE TO SEE SOME SPOTTY CONVECTION MAINLY EITHER
SIDE OF THE VALLEY UNTIL LOSS OF HEATING. BEST LIFT TONIGHT WILL
BE ACROSS THE FAR NE AHEAD OF SHARP SHEAR AXIS. WITH COLUMN COLD
ENOUGH WILL NEED TO MONITOR THE LAKE OF THE WOODS REGION FOR SOME
ACCUMULATING SNOW.
FRIDAY SHOULD BE RELATIVELY QUIET WITH ANY PCPN CONFINED TO THE NE
FA CLOSER TO DEPARTING SURFACE BOUNDARY. MODELS IN DISAGREEMENT ON
HOW FAR SOUTH COLDER AIR WILL SPREAD WITH GFS THE COLDEST. AT ANY
RATE LOOKS TO BE A RESPECTABLE NE-SW ORIENTED THERMAL GRADIENT
ACROSS THE FA WHICH WILL MAKE THE TEMPERATURE FORECAST TRICKY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM CDT THU APR 24 2014
ON SATURDAY BAND OF WARM ADVECTION LIFTS NORTH THROUGH THE WESTERN
FA AS NEXT AREA OF LOW PRESSURE ORGANIZES OVER THE CENTRAL HIGH
PLAINS. WITH GOOD MODEL AGREEMENT INCREASE POPS ACROSS THE WEST.
SURFACE LOW DEEPENS SATURDAY NIGHT OVER CENTRAL HIGH PLAINS AS
NEXT UPPER LOW CROSSES THE CENTRAL ROCKIES. WILL MAINTAIN CURRENT
POPS AS BROAD AREA OF ISENTROPIC LIFT AND LOWERING CONDENSATION
PRESSURE DEFICITS SETS UP.
SUNDAY-WEDNESDAY...HIGH LATITUDE BLOCKING WILL SET UP OVER EASTERN
CANADA...WITH AN INTENSE UPPER WAVE EXPECTED TO LIFT INTO THE
CENTRAL HIGH PLAINS ON SUNDAY BEFORE SLOWLY MEANDERING INTO THE
UPPER MISSISSIPPI VALLEY/GREAT LAKES FOR MID-WEEK. A MAIN SOURCE OF
UNCERTAINTY IS THE DETAILS OF THE EVOLUTION OF THE UPPER LOW AND
DOWNSTREAM RIDGE. MODELS SUGGEST DEEP RELATIVELY MOIST
SOUTH/SOUTHEAST FLOW UPSTREAM FROM THE RIDGE AXIS INTO THE NORTHERN
PLAINS WILL HELP TO PROMOTE WIDESPREAD PRECIPITATION IN THIS REGION
INTO EARLY NEXT WEEK...WITH DRIER AIR ASSOCIATED WITH SFC HIGH
PRESSURE OVER EASTERN CANADA POTENTIALLY INHIBITING PRECIP FARTHER
EAST FOR AT LEAST SOME TIME PERIOD...ESPECIALLY IF THE AMPLIFIED
UPPER RIDGE ENDS UP DISPLACED SLIGHTLY WEST. THERMAL FIELDS VARY
SOMEWHAT AMONG MODELS...BUT KEPT THE IDEA OF PRIMARILY RAIN DURING
THE DAYTIME HOURS WITH PERHAPS SOME MIXED SNOW AT NIGHT. TEMPS ARE
GENERALLY EXPECTED TO REMAIN ON THE COOL SIDE THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 111 PM CDT THU APR 24 2014
EXPECT LINGERING IFR CIGS AT GFK...BJI AND TVF TO SLOWLY RISE TO
MVFR CIGS THIS EARLY AFTN. EXPECT PREDOMINANT CONDS THROUGH
TOMORROW MORNING TO BE MVFR CIGS WITH SOME FLUCTUATIONS UP OR
DOWN. LOW CONFIDENCE THE CLEARING WE ARE SEEING AT FAR WILL REACH
GFK AND CERTAINLY NOT OUR MN TAF SITES. DVL...WHICH IS
CLEAR...SHOULD CU UP AND SEE A THREAT FOR TSTMS ACTIVITY THIS
AFTN. WITH FAR STILL OVC...DO NOT EXPECT CLEARING WILL ALLOW IT TO
HEAT SUFFICIENTLY FOR TSTMS TO GENERATE ALTHOUGH STORMS COULD
ADVECT IN FROM WEST. WILL NOT MENTION TS AT FAR AT THIS TIME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
637 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. MEANWHILE...A COLD
FRONT WILL HEAD EASTWARD...AND SHOULD CROSS OVER THE MID ATLANTIC
BY FRIDAY TO BRING SCATTERED SHOWERS. HIGH PRESSURE WILL RETURN TO
PROVIDE A DRY AND MILD WEEKEND...BEFORE AN UPPER LEVEL AREA OF LOW
PRESSURE PROVIDES COOLER AND WETTER CONDITIONS NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 635 PM EDT THURSDAY...
RAISED EARLY EVENING TEMPERATURES UP A FEW DEGREES WITH SOLAR
HEATING. HIGH PRESSURE WILL SLIDE EAST INTO THE ATLANTIC THIS EVENING
INTO TONIGHT. A COLD FRONT AND ITS ASSOCIATED WARM FRONT WILL
TRAVEL EAST TONIGHT INTO FRIDAY AND PUSH OFFSHORE BY FRIDAY NIGHT.
LOW TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE MID 40S TO THE
LOWER 50S WITH CLOUDS AND WEAK WARM AIR ADVECTION ALOFT. LATEST
RNK WRFARW AND HRRR SUPPORT CURRENT ARRIVAL TIME FOR CONVECTION
ALONG AND AHEAD OF COLD FRONT. NO MAJOR CHANGES IN CLOUDS...PRECIPITATION
AND POPS TONIGHT INTO FRIDAY. WILL MAKE ADDITIONAL CHANGES IN ISC
GRIDS LATER THIS EVENING.
AS OF 355 PM EDT THURSDAY...
SKIES HAVE CLEARED DURING THE PAST FEW HOURS TO ALLOW TEMPERATURES
TO REACH THE LOWER 60S TO THE LOWER 70S THIS AFTERNOON. HIGH
PRESSURE SHOULD DRIFT OFFSHORE LATER TONIGHT. MEANWHILE...A COLD
FRONT WILL CROSS OVER THE OHIO RIVER VALLEY. THE 12Z NAM/ECMWF/GFS
MODEL GUIDANCES HAVE SLOWED DOWN THE ARRIVAL OF THIS FRONT BY A
FEW HOURS...SO POPS WERE TAPERED DOWNWARD DURING THURSDAY NIGHT
FROM THE PREVIOUS FORECAST. LOW TEMPERATURES WERE HELD IN THE MID
40S TO THE LOWER 50S DUE TO CLOUD COVER AND WEAK WARM AIR
ADVECTION ALOFT.
POPS WERE INCREASED LATER ON FRIDAY MORNING HOURS DUE TO GOOD
AGREEMENT AND A LITTLE MORE OVERALL COVERAGE PORTRAYED IN THE
MODELS. SHOWERS SHOULD LINGER INTO THE AFTERNOON...BEFORE THE
FRONT HEADS TOWARD THE COAST BY SUNSET. QPF AMOUNTS WERE ALSO
INCREASED SLIGHTLY TO AROUND A QUARTER OF AN INCH. HOWEVER...WINDS
SHOULD TURN TO THE WEST AND BECOME GUSTY AFTER THE FRONTAL
PASSAGE...AND END ANY OF THE REMAINING RAINFALL. CHANCES OF
THUNDER WERE ONLY PLACED IN SOUTHSIDE VIRGINIA WERE BUFKIT MODEL
SOUNDINGS SHOW CAPE EXCEEDING 500 J/KG DURING THE AFTERNOON. SPC
KEEPS ANY SEVERE WEATHER THREAT WELL TO THE EAST OF OUR CWA. HIGHS
ON FRIDAY WERE KEPT ON THE SLIGHTLY COOLER SIDE OF GUIDANCE DUE TO
CLOUDS AND RAIN...WITH LOWER 60S TO LOWER 70S EXPECTED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 315 PM EDT THURSDAY...
MOST PRECIP WILL HAVE EXITED THE REGION AT THE BEGINNING OF THIS
PERIOD...SAVE SOUTHSIDE VA/NC PIEDMONT AND THE GREENBRIER VALLEY.
GOOD BURST OF WIND BEHIND THIS COMPACT YET DECENT SHRTWV...WITH SOME
30 KT GUSTS FRIDAY EVENING AT THE USUAL LOCATIONS. SLIGHTLY COOLER
AIR SLIPS INTO THE GREENBRIER VALLEY AND SOUTHERN SHENANDOAH BEHIND
THIS BOUNDARY...BUT WAA RETURNS QUICKLY ACROSS THE SOUTHERN HALF OF
THE CWA. ANOTHER DISTURBANCE DROPPING THROUGH THE GREAT LAKES LATE
SATURDAY...MAY ALLOW SCATTERED SHOWERS AND A THUNDERSTORMS TO FORM
JUST AHEAD OF A COLD FRONT WHICH STALLS AROUND ELKINS WV...WITH SOME
OF THESE WEAKENING...PERHAPS AS THEY MOVE INTO THE GREENBRIER VALLEY
AND THE SOUTHERN SHENANDOAH. SOMETIMES MODELS STRUGGLE WITH THIS
REGIME...SO FOR NOW AT LEAST WENT WITH SLT CHC POPS IN THESE AREAS.
H85 TEMPS IN THE LOWER TEENS TO NEAR +15C CONTINUE FOR SUNDAY...WITH
SOME SPOTS TOUCHING 80F POSSIBLY SATURDAY AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EDT THURSDAY...
THE NEXT WORKWEEK IS SHAPING UP TO BE ON THE WET SIDE AS A MASSIVE
UPPER LEVEL LOW PINWHEELS EAST FROM THE CENTRAL AND NORTHERN PLAINS.
WILL START MONDAY OUT WITH COOL HIGH PRESSURE WEDGING SOUTHWARD
AGAINST THE EASTERN FACE OF THE APPALACHIANS...MAINTAINING A COOL
EASTERLY WIND ACROSS OUR AREA. A WARM FRONT WILL NORTH ALONG THE
MISSISSIPPI RIVER VALLEY...BUT WILL GET HUNG UP AGAINST THE
APPALACHIANS. AS SUCH...EXPECT SHOWERY WEATHER MONDAY AND TUESDAY...
WITH AN OUTSIDE CHANCE FOR THUNDERSTORMS ACROSS THE MOUNTAIN EMPIRE
AND PERHAPS THE NORTH CAROLINA FOOTHILLS...WHERE THE STABILIZING
AFFECT OF THE HIGH PRESSURE WEDGE WILL BE WEAKEST. WILL SEE A BETTER
THREAT FOR THUNDERSTORMS ON WEDNESDAY AS THE LOW PRESSURE SYSTEM
NEARS THE REGION...ALLOWING THE WARM FRONT TO LIFT NORTHWARD BEFORE
THE TRAILING COLD FRONT MOVES IN.
EASTERLY FLOW AROUND THE HIGH WILL ALSO RESULT IN COOLER
TEMPERATURES...AND THEREFORE UNDERCUT MODEL GUIDANCE BY A FEW
DEGREES. HOWEVER...TEMPERATURES REMAIN LOW CONFIDENCE...AND BELIEVE
IT IS POSSIBLE THAT DID NOT GO LOW ENOUGH FOR AFTERNOON HIGHS MONDAY
AND PARTICULARLY TUESDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 150 PM EDT THURSDAY...
THERE IS HIGH CONFIDENCE OF VFR CONDITIONS CONTINUING THROUGH THE
REST OF TODAY INTO EARLY TONIGHT. HIGH PRESSURE WILL DRIFT TOWARD
THE EAST COAST THIS AFTERNOON. WINDS SHOULD REMAIN LIGHT AND
GENERALLY FROM THE SOUTH...AND SOME CIRRUS WILL CONTINUE TO SPILL
OVER THE AREA FROM A COLD FRONT WELL UPSTREAM IN THE GREAT PLAINS.
AS HIGH PRESSURE HEADS OFFSHORE TONIGHT...CLOUDS SHOULD GRADUALLY
INCREASE IN COVERAGE AHEAD OF THE APPROACHING COLD FRONT. THIS
FRONT IS PROGGED TO TRACK OVER THE MID ATLANTIC BY FRIDAY.
CEILINGS SHOULD LOWER BY DAYBREAK...WITH A FAIRLY GOOD POSSIBILITY
OF MVFR AS NOTED IN THE LAMP GUIDANCE. PRECIPITATION ASSOCIATED
WITH THE FRONT SHOULD MAINLY BE SHOWERS. THERE IS A SMALL THREAT
FOR THUNDERSTORMS IN THE NORTH CAROLINA AND VIRGINIA PIEDMONT
TOWARD FRIDAY AFTERNOON...BUT THE CHANCES ARE TOO LOW TO WARRANT
MENTION IN ANY OF THE TAFS.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT SHOULD DEPART OFFSHORE BY FRIDAY NIGHT. WINDS WILL
TURN TO THE NORTHWEST AND INCREASE DURING FRIDAY NIGHT INTO
SATURDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH THIS WEEKEND...AS
HIGH PRESSURE MOVES OVERHEAD. CLOUD COVER WILL STEADILY INCREASE
BY MONDAY...AS A LOW PRESSURE SYSTEM SLOWLY ARRIVES FROM THE
WEST. CONDITIONS MAY DROP BELOW VFR WHEN SCATTERED SHOWERS MOVE
OVER THE MID ATLANTIC DURING LATE MONDAY...AND CHANCES FOR MVFR
ARE EVEN BETTER ON TUESDAY DUE TO PROLONGED CLOUDS AND RAIN.
&&
.FIRE WEATHER...
AS OF 637 PM EDT THURSDAY...
LOW RH VALUES SHOULD RECOVER AFTER SUNSET THIS EVENING INTO
TONIGHT. BY FRIDAY...A COLD FRONT SHOULD PROVIDE SOME WETTING
SHOWERS FOR FRIDAY...ALTHOUGH AMOUNTS WILL BE AROUND A QUARTER OF
AN INCH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...KK/PW
SHORT TERM...KM
LONG TERM...NF
AVIATION...PW
FIRE WEATHER...KK/PW