Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/09/15


AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
122 PM CDT TUE APR 7 2015 .AVIATION...07/18Z TAF CYCLE MVFR CIGS WL BE NOTED ACRS THE FA THRU MOST OF THIS AFTN. HOWEVER... INCRSG LOW LVL MIXING WL HELP CIGS TO GRADUALLY LIFT TO VFR LVLS LATER THIS AFTN AND LINGER INTO THIS EVENING. LOW CLOUDS WL THEN RETURN LATER TNGT...WITH VFR/MVFR CONDS EXPECTED. OUTSIDE AN ISOLD SHRA/TSRA THRU THIS EVENING...NO ORGANIZED CONVECTION IS ANTICIPATED TO AFFECT THE FA THRU WED MRNG. /44/ && .PREV DISCUSSION... /ISSUED 1009 AM CDT TUE APR 7 2015/ UPDATE... NO SIGNIFICANT CHANGES MADE FOR THE MORNING UPDATE. RADAR TRENDS SHOW THAT PRECIPITATION IS ABOUT TO COME TO AN END ACROSS THE FORECAST AREA...WITH ONLY SOME ISOLATED THUNDERSTORMS LEFT UP AROUND THE BATESVILLE AREA AS OF 10 AM. BY NOON ALL RAIN WILL HAVE EXITED AND EXPECT DRY CONDITIONS FOR THE REST OF TODAY. ADJUSTED POPS THROUGH THE MORNING TO REFLECT THESE TRENDS...AND HAVE NO PRECIP MENTIONED FOR THE AFTERNOON PERIOD. TEMPERATURES LOOK ON TRACK SO NO ADJUSTMENTS THERE EITHER. PREV DISCUSSION... /ISSUED 621 AM CDT TUE APR 7 2015/ AVIATION... SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT. PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/ SHORT TERM...TODAY THROUGH FRIDAY SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE. OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY. WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING THE CAP. THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE. MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH THIS SYSTEM. HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE. TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS. LONG TERM...FRIDAY NIGHT THROUGH MONDAY HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT... AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO THE REGION DURING THE DAY. IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP... PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS... HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY TUNED. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1009 AM CDT TUE APR 7 2015 .UPDATE... NO SIGNIFICANT CHANGES MADE FOR THE MORNING UPDATE. RADAR TRENDS SHOW THAT PRECIPITATION IS ABOUT TO COME TO AN END ACROSS THE FORECAST AREA...WITH ONLY SOME ISOLATED THUNDERSTORMS LEFT UP AROUND THE BATESVILLE AREA AS OF 10 AM. BY NOON ALL RAIN WILL HAVE EXITED AND EXPECT DRY CONDITIONS FOR THE REST OF TODAY. ADJUSTED POPS THROUGH THE MORNING TO REFLECT THESE TRENDS...AND HAVE NO PRECIP MENTIONED FOR THE AFTERNOON PERIOD. TEMPERATURES LOOK ON TRACK SO NO ADJUSTMENTS THERE EITHER. && .PREV DISCUSSION... /ISSUED 621 AM CDT TUE APR 7 2015/ AVIATION... SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT. PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/ SHORT TERM...TODAY THROUGH FRIDAY SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE. OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY. WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING THE CAP. THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE. MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH THIS SYSTEM. HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE. TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS. LONG TERM...FRIDAY NIGHT THROUGH MONDAY HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT... AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO THE REGION DURING THE DAY. IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP... PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS... HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY TUNED. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 80 65 82 65 / 30 10 20 30 CAMDEN AR 83 65 84 66 / 20 10 10 20 HARRISON AR 80 63 82 63 / 10 20 20 40 HOT SPRINGS AR 81 67 82 66 / 20 10 10 20 LITTLE ROCK AR 82 66 83 65 / 30 10 10 20 MONTICELLO AR 82 65 84 67 / 20 10 10 10 MOUNT IDA AR 80 66 79 67 / 10 10 10 30 MOUNTAIN HOME AR 79 63 83 63 / 20 20 20 40 NEWPORT AR 80 65 82 66 / 30 20 20 20 PINE BLUFF AR 82 65 83 65 / 30 10 10 20 RUSSELLVILLE AR 81 63 83 64 / 20 10 20 30 SEARCY AR 80 63 82 64 / 30 10 20 20 STUTTGART AR 81 66 82 66 / 30 10 10 20 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 64
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
621 AM CDT TUE APR 7 2015 .AVIATION... SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH PREVAILING CONDITIONS MVFR TO IFR. CONDITIONS WILL IMPROVE LATE THIS MORNING AND INTO THE AFTERNOON...WITH MOST AREAS VFR AROUND OR A LITTLE AFTER 18Z. MVFR LOW CLOUDS AND FOG WILL RETURN LATE TONIGHT...MAINLY AFTER 06Z. WINDS WILL BE SOUTHERLY AROUND 10 KNOTS TODAY...WITH HIGHER GUSTS. TAS ALREADY OUT. && .PREV DISCUSSION... /ISSUED 333 AM CDT TUE APR 7 2015/ SHORT TERM...TODAY THROUGH FRIDAY SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE. OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY. WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING THE CAP. THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE. MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH THIS SYSTEM. HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE. TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS. LONG TERM...FRIDAY NIGHT THROUGH MONDAY HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT... AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO THE REGION DURING THE DAY. IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP... PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS... HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY TUNED. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...57
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
333 AM CDT TUE APR 7 2015 .SHORT TERM...TODAY THROUGH FRIDAY SHOWERS AND A FEW THUNDERSTORMS DEVELOPED ACROSS THE STATE DURING THE OVERNIGHT HOURS WITH SOME PATCHY FOG DEVELOPING. HRRR SUGGESTS THESE SHOWERS WILL INCREASE IN COVERAGE THROUGH THE EARLY MORNING HOURS AND KEEP RAIN CHANCES IN THE FORECAST THROUGH THE LATE MORNING...GENERALLY ACROSS THE EASTERN HALF OF THE STATE. OTHERWISE...PRECIPITATION WILL BE LIMITED ON TUESDAY WITH A STRONGLY CAPPED ATMOSPHERE IN PLACE. THE BEST CHANCES FOR PRECIPITATION...RELATIVELY SPEAKING...WILL BE ACROSS NORTHERN ARKANSAS...BUT EVEN STILL NOT CONFIDENT ENOUGH TO GO ABOVE SLIGHT CHANCES. WINDS WILL BE A BIT ON THE STRONG SIDE TODAY...BUT NOT STRONG ENOUGH TO WARRANT A LAKE WIND ADVISORY. WEDNESDAY...PRECIPITATION CHANCES WILL SOMEWHAT INCREASE...MAINLY ACROSS WESTERN ARKANSAS AS A COLD FRONT SLOWLY MARCHES TOWARD THE STATE. ATMOSPHERE STILL LOOKS TO BE FAIRLY CAPPED ON WEDNESDAY...HOWEVER UPPER LEVEL RIDGE WILL BEGIN TO PUSH TO THE EAST ALLOWING TEMPERATURES ALOFT TO SOMEWHAT COOL AND SOMEWHAT WEAKENING THE CAP. THURSDAY CONTINUES TO LOOK LIKE THE BEST CHANCE FOR SEVERE WEATHER ACROSS THE CWA. SURFACE LOW PRESSURE WILL TRACK FROM COLORADO THROUGH IOWA...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH THE STATE. MODEL SOUNDINGS TO CONTINUE TO SHOW THE POTENTIAL FOR SEVERE WEATHER IN THE STATE WILL ALL MODES POSSIBLE. THE COLD FRONT ITSELF WILL NOT ENTER THE STATE UNTIL 00Z...AND PUSH THROUGH THE STATE BY 12Z FRIDAY. WITH AMPLE MOISTURE IN PLACE AFTER QUITE A FEW DAYS OF STRONG SOUTHERLY FLOW...HEAVY RAIN CONTINUES TO BE A CONCERN WITH THIS SYSTEM. HIGH PRESSURE AND DRY WEATHER WILL MOVE INTO THE STATE FOR FRIDAY...WITH THE FRONT STALLING JUST TO THE SOUTH OF THE STATE. TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS. && .LONG TERM...FRIDAY NIGHT THROUGH MONDAY HIGH PRESSURE WILL BE MOVING THROUGH THE AREA ON FRIDAY NIGHT...WITH THE FRONT STALLED OUT JUST TO THE SOUTH OF THE REGION. THE HIGH WILL MOVE EASTWARD ON SATURDAY...WITH RETURN FLOW SETTING UP AS THE FRONT BEGINS TO BACK NORTHWARD. SHOWERS AND THUNDERSTORMS WILL RETURN TO THE FORECAST...WITH THE HIGHEST CHANCES ON SUNDAY AND SUNDAY NIGHT... AS THE WARM FRONT MOVES THROUGH...ALONG WITH AN UPPER TROUGH WITH A BIT OF A NEGATIVE TILT. EXTENDED RANGE MODELS ARE SHOWING A SURFACE LOW DEVELOPING SUNDAY NIGHT INTO MONDAY...DRAGGING A COLD FRONT INTO THE REGION DURING THE DAY. IF THE AFOREMENTIONED SCENARIO PANS OUT...SEVERE THUNDERSTORMS MAY BE POSSIBLE. ALSO...WITH GULF AND PACIFIC MOISTURE LINING UP... PRECIPITABLE WATER VALUES WILL BE APPROACHING TWO INCHES. THUS... HEAVY RAINFALL WOULD BE A POSSIBILITY AS WELL. WILL CONTINUE TO MONITOR THIS POTENTIAL HAZARDOUS WEATHER SETUP...AND ADJUST SUCCESSIVE FORECASTS ACCORDINGLY. ONE THING THAT IS CONCERNING IS THAT...THOUGH THE SMALL DETAILS DIFFER TO VARYING DEGREES...THE MODELS ARE IN REMARKABLY GOOD AGREEMENT FOR SIX DAYS OUT. STAY TUNED. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 80 65 82 65 / 20 10 20 30 CAMDEN AR 83 65 84 66 / 20 10 10 20 HARRISON AR 80 63 82 63 / 20 20 30 40 HOT SPRINGS AR 81 67 82 66 / 20 10 10 20 LITTLE ROCK AR 82 66 83 65 / 20 10 10 20 MONTICELLO AR 82 65 84 67 / 20 10 10 10 MOUNT IDA AR 80 66 79 67 / 20 10 10 30 MOUNTAIN HOME AR 79 63 83 63 / 20 20 30 40 NEWPORT AR 80 65 82 66 / 20 20 20 20 PINE BLUFF AR 82 65 83 65 / 20 10 10 20 RUSSELLVILLE AR 81 63 83 64 / 20 10 20 30 SEARCY AR 80 63 82 64 / 20 10 20 20 STUTTGART AR 81 66 82 66 / 20 10 10 20 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...65 / LONG TERM...57
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1005 AM PDT TUE APR 7 2015 .UPDATE... CURRENT FORECAST IS GENERALLY ON THE RIGHT TRACK WITH NO SIGNIFICANT CHANGES PLANNED THIS MORNING. SO FAR THIS MORNING, THE MAIN IMPACTS OF THE SNOW BAND OVER CALIFORNIA HAVE BEEN LIMITED TO AREAS NEAR AND WEST OF THE SIERRA CREST. CHAIN CONTROLS ARE CURRENTLY IN PLACE ON I-80 OVER DONNER SUMMIT AND CA 88 OVER CARSON PASS. FOR THE REMAINDER OF THE MORNING, THE STEADY SNOW BAND WILL BEGIN TO DECREASE IN COVERAGE WITH SOME AREAS OF MOISTURE BREAKING OFF AND SPREADING INTO WESTERN NV. AIR MASS IN LOWER ELEVATIONS IS STILL RELATIVELY DRY SO LITTLE OR NO MEASURABLE PRECIP IS EXPECTED ACROSS THE RENO-CARSON CITY VICINITY THROUGH MIDDAY. FOR THIS AFTERNOON AS THE COLD POOL ALOFT MOVES INTO CENTRAL CA, CONVECTION WILL INCREASE WITH BANDS OF SNOW SHOWERS SPREADING OVER THE SIERRA. ROAD SURFACES WILL LIKELY BECOME WET OR SLUSHY NEAR THE SIERRA FROM MIDDAY THROUGH MID AFTERNOON AS HIGHER SUN ANGLES ASSIST IN MELTING OFF THE SNOW WHICH HAS ALREADY FALLEN. SOME OF THIS SNOW SHOWER ACTIVITY WILL CONTINUE INTO THE EVENING WITH POTENTIAL FOR MORE TRAVEL IMPACTS AS ROAD SURFACE TEMPS DECREASE. FOR WESTERN NV, THE TRANSITION TO A CONVECTIVE REGIME WILL LEAD TO INCREASED SHOWER DEVELOPMENT WITH ISOLATED THUNDERSTORMS POSSIBLE WITH SMALL HAIL OR GRAUPEL OCCURRING WITH STRONGER CELLS. THE LATEST HRRR AND NAM GUIDANCE SHOW CONDITIONS A LITTLE MORE FAVORABLE FOR THUNDER IN AREAS NORTH AND EAST OF A RENO-FALLON LINE BETWEEN 1 AND 7 PM. FARTHER SOUTH IN MONO COUNTY, THE MONO LAKE WEB CAMERA SHOWED A SMALL AREA OF BLOWING DUST WITH A WIND SENSOR NEAR THE LAKE SHOWING SPEEDS IN THE 20-30 MPH RANGE. SOME GUSTS TO 40 MPH WILL BE POSSIBLE ALONG HIGHWAY 395 BEFORE SHOWERS SPREAD ACROSS THE COUNTY LATER TODAY. MJD && .PREVIOUS DISCUSSION... /ISSUED 247 AM PDT TUE APR 7 2015/ SYNOPSIS... LOW PRESSURE WILL BRING SNOW AND SLICK ROAD CONDITIONS TO THE SIERRA TODAY INTO WEDNESDAY MORNING, WITH SNOW AND RAIN SHOWERS IN LOWER ELEVATIONS. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MIDWEEK, FOLLOWED BY A WARMING AND DRYING TREND LATER IN THE WEEK. SHORT TERM... A COLD SPRING STORM IS BEGINNING TO PUSH A BAND OF PRECIPITATION ACROSS THE NORTHERN CALIFORNIA COAST EARLY THIS MORNING. THIS BAND OF PRECIPITATION WILL PUSH EASTWARD AND PROVIDE ACCUMULATING SNOW IN THE SIERRA LATER THIS MORNING THROUGH EARLY WEDNESDAY MORNING. WINTER WEATHER ADVISORIES ARE IN PLACE ACROSS THE EASTERN SIERRA WHERE SNOW COVERED ROADS AND CHAIN RESTRICTIONS ARE EXPECTED THROUGH THE SIERRA. SNOW ACCUMULATIONS THROUGH WEDNESDAY MORNING ACROSS THE EASTERN SIERRA ARE GENERALLY IN THE 6-12" RANGE FOR LOCATIONS ABOVE 7,000 FEET WITH ABOUT 3-6" THROUGH THE TAHOE BASIN AND AREAS WEST OF HWY 395 THROUGH MONO COUNTY. INSTABILITY WILL INCREASE THROUGH THE DAY AS THE COLD CORE OF THE UPPER LOW SETTLES ACROSS THE REGION. THIS WILL PROMOTE THE DEVELOPMENT OF LOCALIZED AREAS OF HEAVIER SNOWFALL WITHIN STRONGER CELLS, SNOW PELLETS, SMALL HAIL, AND ISOLATED LIGHTNING STRIKES. ACROSS WESTERN NEVADA, SHOWERS LOOK TO PUSH INTO THE AREA AFTER NOON WITH A MIX OR RAIN AND SNOW EXPECTED AS SNOW LEVELS HOVER AROUND 4,500-5,000 FEET THROUGH THE DAY. LITTLE TO NO ACCUMULATION IS EXPECTED ACROSS WESTERN NEVADA VALLEYS WITH HIGH SUN ANGLES IN PLACE, BUT LOCATIONS ABOVE 5,000 MAY SEE BETTER CHANCES FOR SOME SLUSHY ACCUMULATIONS. SHOWERS WILL LINGER THROUGH THE EVENING WITH THE BULK THE HEAVIER PRECIPITATION ENDING BY LATE AFTERNOON. TRAVEL IMPACTS ARE POSSIBLE THROUGH TONIGHT AS SHOWERS DIMINISH BUT POTENTIAL INCREASES FOR SNOW TO STICK ON ROADWAYS ACROSS THE SIERRA. BREEZY CONDITIONS WILL ACCOMPANY THE STORM WITH SOUTHERLY WINDS SHIFTING WEST BY EARLY AFTERNOON THEN NORTHWEST THIS EVENING AS THE COLD FRONT PUSHES ACROSS THE REGION. WILL GENERALLY SEE GUSTS IN THE 30-35 MPH RANGE WITH GUSTS ACROSS THE SIERRA CREST AROUND 60-70 MPH. CHOPPY CONDITIONS EXPECTED ACROSS AREAS LAKES WITH WINDS LESSENING WITH THE ONSET OF PRECIPITATION. BY WEDNESDAY MORNING, THE MAIN UPPER LOW SHIFTS EASTWARD ACROSS UTAH WITH ONLY A FEW LIGHT LINGERING SHOWERS EXPECTED. SOME BANDED PRECIPITATION IS POSSIBLE ON THE BACKSIDE OF THE LOW BUT IT LOOKS TO BE MAINLY CONFINED TO FAR NORTHEASTERN NEVADA WITH SOME SHOWERS EXTENDING AS FAR WEST AS FAR NORTHERN WASHOE COUNTY AND THE SURPRISE VALLEY. SHOWERS DIMINISH BY WEDNESDAY EVENING AS A SHORTWAVE BEGINS TO BUILD ACROSS THE AREA BY THURSDAY WHERE DAYTIME TEMPERATURES WILL REBOUND BACK INTO THE LOWER 60S ACROSS WESTERN NEVADA AND MID 50S FOR THE SIERRA. FUENTES LONG TERM...FRIDAY THROUGH MONDAY... FORECASTER CONFIDENCE IS RISING FOR THE EXTENDED FORECAST AS MODELS HAVE COME INTO BETTER AGREEMENT OVER THE LAST 24 HOURS SHOWING THE DEVELOPING PATTERN OVER THE WEST COAST. GFS CONTINUES TO TREND LOWER HEIGHTS OVER NORTHERN CA/NV FOR THE WEEKEND AS THE NORTHERN BRANCH OF A SPLIT JET DIVES INTO THE WEST COAST AND ACROSS THE GREAT BASIN. ECMWF AND GEM ARE IN GOOD AGREEMENT AS WELL, BRINGING A COLD FRONT ACROSS THE REGION WITH CHANCES OF LIGHT PRECIPITATION. THE MAJORITY OF THE PRECIP/DYNAMICS WILL REMAIN IN THE PACIFIC NORTHWEST WITH ONLY A VERY MODEST AMOUNT OF MOISTURE PUSHING NEAR THE CA/NV/OR BORDER. IN THAT AREA NORTH OF SUSANVILLE, WE EXPANDED THE SLIGHT CHANCE OF SHOWERS INTO SATURDAY AND KEPT CHANCES IN THROUGH SUNDAY TO ACCOUNT FOR MODEL DIFFERENCES IN THE TIMING OF THE WAVE. WE SHOULD BEGIN TO WARM BACK UP SUNDAY-MONDAY AS WEAK RIDGING BUILDS OVER THE WEST COAST. MODELS CONTINUE TO HINT AT YET ANOTHER TROUGH DROPPING OUT OF THE GULF OF ALASKA AND INTO THE PAC NW NEXT WEEK, KEEPING THE ACTIVE WEATHER PATTERN GOING. HOON AVIATION... SIGNIFICANT SPRING STORM WILL BE PUSHING INTO THE SIERRA TODAY WITH LIGHT SHOWERS IN WESTERN NEVADA. IFR CIGS/VIS WILL DEVELOP AROUND 16Z THIS MORNING AROUND THE TAHOE BASIN WITH PERIODS OF MODERATE SNOW. SHOWERS WILL LINGER THROUGH TONIGHT IN THE SIERRA WITH PERIODS OF MVFR/IFR. FOR WESTERN NEVADA, THE BEST POSSIBLE TIME FOR SPILLOVER WILL BE BETWEEN 18Z-00Z WITH A MIX OF RAIN, SNOW AND SNOW PELLET SHOWERS POSSIBLE. IN ADDITION, THERE IS A 15 PERCENT FOR THUNDERSTORMS TODAY, BUT CONFIDENCE IS LOW IN PINPOINTING THE LOCATION OF WHERE THE STORMS WILL FORM. ACCUMULATING SNOW IS LIKELY ON RUNWAYS AT KTRK, KTVL, AND KMMH TODAY, THOUGH IT MAY JUST BE SLUSHY DURING THE MIDDLE PART OF THE DAY DUE TO THE APRIL SUN ANGLE. MIDDAY WILL BE THE BEST CHANCES FOR SPILLOVER INTO WESTERN NEVADA, SO IT IS UNLIKELY SNOW WILL ACCUMULATE ON RUNWAYS AT KRNO OR KCXP. SOUTHERLY WINDS TOMORROW WILL BECOME WESTERLY BEHIND THE COLD FRONTAL PASSAGE, WHICH WILL BE APPROXIMATELY BETWEEN 18-21Z. WINDS MAY GUST AS HIGH AS 25-30 KTS IN VALLEYS WITH 55-60 KTS ACROSS SIERRA RIDGES. THIS WILL LEAD TO WEAK TO MODERATE MOUNTAIN TURBULENCE AND A SLIGHT CHANCE OF LOW LEVEL WIND SHEAR ALONG THE COLD FRONT. DJ/HOON && .REV WATCHES/WARNINGS/ADVISORIES... NV...WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY NVZ002. CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ071. WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ073. WINTER WEATHER ADVISORY UNTIL 5 AM PDT WEDNESDAY CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
434 AM PDT TUE APR 7 2015 ...LATE SEASON STORM TO IMPACT THE REGION THROUGH TONIGHT... .SYNOPSIS...RAIN WILL GO THROUGH OUR AREA THIS MORNING. ALONG WITH LOCALLY HEAVY RAINFALL...THUNDERSTORMS WITH SMALL HAIL AND GUSTY WINDS WILL BE POSSIBLE AS THE SYSTEM MOVES INLAND. IN ADDITION...SNOW ACCUMULATIONS WILL BE POSSIBLE OVER THE SANTA LUCIA RANGE ABOVE 4000 FEET. DRY WEATHER CONDITIONS RETURN BY MIDWEEK AS THE SYSTEM EXITS THE REGION. && .DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AS EXPECTED RADAR RETURNS HAVE INCREASED THROUGH THE OVERNIGHT HOURS AS A STRONG FRONT MOVES ACROSS OUR AREA. LATEST LOOK AT KMUX SHOWS A BAND OF MODERATE RAIN ENTERING THE SF BAY REGION ASSOCIATED WITH THE HEAVILY ADVERTISED COLD FRONT. SO FAR RAINFALL RETURNS HAVE BEEN DECENT WITH PARTS OF SONOMA COUNTY OVER THREE QUARTERS OF AN INCH. LATEST RUN OF THE HRRR SHOWS THE BEST POTENTIAL FOR MODERATE TO POSSIBLY HEAVY RAINFALL THROUGH THE MORNING HOURS IN A REGION FROM THE SOUTH BAY OVER TO THE FAR EAST BAY VALLEYS AND THEN SOUTH INTO SANTA CRUZ COUNTY. THOSE SPOTS COULD EASILY SEE HALF AN INCH BY MID-MORNING. WINDS PICKED UP THROUGH THE EVENING HOURS ALTHOUGH STRONG GUSTS GENERALLY HAVE BEEN CONFINED TO HIGHER ELEVATION SPOTS. A FEW URBAN AREAS ARE SEEING GUSTS OVER 25 MPH INCLUDING BOTH THE SFO AND OAKLAND AIRPORTS. FOR SPOTS OVER 1000 FEET GUSTS OVER 35 MPH ARE FAIRLY COMMON ESPECIALLY FOR OUR TYPICAL WINDY SPOTS. BEHIND THE COLD FRONT THE ATMOSPHERE WILL DESTABILIZE WITH LIFTED VALUES EXPECTED TO DROP AS LOW AS MINUS 3 WHILE CAPE VALUES COULD EXCEED 200 J/KG. WOULD EXPECT AT LEAST A FEW THUNDERSTORMS ACROSS OUR AREA ALONG WITH REPORTS OF SMALL HAIL. WORTH NOTING THAT VERY LITTLE DIRECTIONAL SHEER IS FORECAST FOR OUR AREA WITH ONLY LIMITED SPEED SHEER WHICH WILL HELP TO LIMIT THE THREAT OF SEVERE WEATHER. THE COOLER AIR WILL LEAD TO LOWER SNOW LEVELS WITH ACCUMULATIONS EXPECTED OVER 4000 FEET. STILL LOOKS LIKE THE SANTA LUCIA RANGE COULD PICK UP 3 TO 6 INCHES OF SNOW. ALL TOO FAMILIAR RIDGE OF HIGH PRESSURE WILL BUILD BACK TO OUR AREA STARTING ON WEDNESDAY AS THE SYSTEM DEPARTS TO THE EAST. THIS WILL LEAD TO THE STORM TRACK HEADING BACK WELL TO THE NORTH ALONG WITH WARMER TEMPERATURES. LONGER RANGE OUTLOOKS DO NOT INDICATE ANY ADDITIONAL SUBSTANTIAL STORMS PAST TODAY GOING ALL OF THE WAY TO APRIL 20TH. && .AVIATION...AS OF 04:27 AM PDT TUESDAY...A COLD FRONT IS CURRENTLY TRAVERSING THE BAY AREA BRINGING RAIN AND GUSTY WINDS. FOR THE MOST PART FLIGHT CAT ARE VFR WITH A FEW POCKETS OF MVFR. THE IMPACT TO TERMINALS WILL BE EARLY THIS MORNING THROUGH THE MORNING RUSH WITH WET RUNWAYS AND WIND. FOLLOWING SHORT TERM MODELS...RAIN WILL TAPER OFF FROM N-S AFTER 14/15Z. STEADIER RAIN TRANSITIONS TO HIT MORE MISS SHOWERS/CONVECTIVE NATURE. WINDS WILL ALSO DIMINISH AFTER 15Z. VFR CONDITIONS TONIGHT. CONF IS MEDIUM. VICINITY OF KSFO...TIMING OF PERSISTENT RAINFALL THROUGH APPROX 15Z WITH GUSTY WINDS. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...RAIN THROUGH MID MORNING THEN VCSH THIS AFTERNOON. && .MARINE...AS OF 04:26 AM PDT TUESDAY...A COLD FRONT WILL MOVE THROUGH THE COASTAL WATERS EARLY TODAY PRODUCING GUSTY WINDS...RAIN AND THUNDERSTORMS. THE GUSTY WINDS WILL PRODUCE LOCALLY HAZARDOUS CONDITIONS. WINDS WILL DECREASE FROM NORTH TO SOUTH THROUGH THE DAY AS THE FRONT EXITS THE REGION WITH AN IMPROVING SEA STATE. NORTHWEST SWELL THROUGH THE PERIOD. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WINTER WEATHER ADVISORY...SANTA LUCIA RANGE THROUGH TONIGHT. SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 AM SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 8 AM SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 8 AM SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 8 AM SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 8 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 11 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 11 AM && $$ PUBLIC FORECAST: BELL AVIATION/MARINE: MM VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
302 AM PDT TUE APR 7 2015 ...LATE SEASON STORM TO IMPACT THE REGION THROUGH TONIGHT... .SYNOPSIS...RAIN WILL GO THROUGH OUR AREA THIS MORNING. ALONG WITH LOCALLY HEAVY RAINFALL...THUNDERSTORMS WITH SMALL HAIL AND GUSTY WINDS WILL BE POSSIBLE AS THE SYSTEM MOVES INLAND. IN ADDITION...SNOW ACCUMULATIONS WILL BE POSSIBLE OVER THE SANTA LUCIA RANGE ABOVE 4000 FEET. DRY WEATHER CONDITIONS RETURN BY MIDWEEK AS THE SYSTEM EXITS THE REGION. && .DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AS EXPECTED RADAR RETURNS HAVE INCREASED THROUGH THE OVERNIGHT HOURS AS A STRONG FRONT MOVES ACROSS OUR AREA. LATEST LOOK AT KMUX SHOWS A BAND OF MODERATE RAIN ENTERING THE SF BAY REGION ASSOCIATED WITH THE HEAVILY ADVERTISED COLD FRONT. SO FAR RAINFALL RETURNS HAVE BEEN DECENT WITH PARTS OF SONOMA COUNTY OVER THREE QUARTERS OF AN INCH. LATEST RUN OF THE HRRR SHOWS THE BEST POTENTIAL FOR MODERATE TO POSSIBLY HEAVY RAINFALL THROUGH THE MORNING HOURS IN A REGION FROM THE SOUTH BAY OVER TO THE FAR EAST BAY VALLEYS AND THEN SOUTH INTO SANTA CRUZ COUNTY. THOSE SPOTS COULD EASILY SEE HALF AN INCH BY MID-MORNING. WINDS PICKED UP THROUGH THE EVENING HOURS ALTHOUGH STRONG GUSTS GENERALLY HAVE BEEN CONFINED TO HIGHER ELEVATION SPOTS. A FEW URBAN AREAS ARE SEEING GUSTS OVER 25 MPH INCLUDING BOTH THE SFO AND OAKLAND AIRPORTS. FOR SPOTS OVER 1000 FEET GUSTS OVER 35 MPH ARE FAIRLY COMMON ESPECIALLY FOR OUR TYPICAL WINDY SPOTS. BEHIND THE COLD FRONT THE ATMOSPHERE WILL DESTABILIZE WITH LIFTED VALUES EXPECTED TO DROP AS LOW AS MINUS 3 WHILE CAPE VALUES COULD EXCEED 200 J/KG. WOULD EXPECT AT LEAST A FEW THUNDERSTORMS ACROSS OUR AREA ALONG WITH REPORTS OF SMALL HAIL. WORTH NOTING THAT VERY LITTLE DIRECTIONAL SHEER IS FORECAST FOR OUR AREA WITH ONLY LIMITED SPEED SHEER WHICH WILL HELP TO LIMIT THE THREAT OF SEVERE WEATHER. THE COOLER AIR WILL LEAD TO LOWER SNOW LEVELS WITH ACCUMULATIONS EXPECTED OVER 4000 FEET. STILL LOOKS LIKE THE SANTA LUCIA RANGE COULD PICK UP 3 TO 6 INCHES OF SNOW. ALL TOO FAMILIAR RIDGE OF HIGH PRESSURE WILL BUILD BACK TO OUR AREA STARTING ON WEDNESDAY AS THE SYSTEM DEPARTS TO THE EAST. THIS WILL LEAD TO THE STORM TRACK HEADING BACK WELL TO THE NORTH ALONG WITH WARMER TEMPERATURES. LONGER RANGE OUTLOOKS DO NOT INDICATE ANY ADDITIONAL SUBSTANTIAL STORMS PAST TODAY GOING ALL OF THE WAY TO APRIL 20TH. && .AVIATION...AS OF 10:52 PM PDT MONDAY...GUSTY S-SE PRE-FRONTAL WIND PATTERN IS EXPECTED OVER THE FORECAST AREA TONIGHT. THE COLD FRONT WILL SWEEP QUICKLY E-SE ACROSS THE AREA AFTER MIDNIGHT FOLLOWED BY MUCH COLDER AIR ALOFT AND INSTABILITY SHOWERS BEGINNING EARLY TUE. ISOLATED T-STORM(S) ALSO POSSIBLE BEGINNING TUE MORNING BUT MUCH TOO LOW CONFIDENCE TO ATTEMPT TO TIME ONE OR MORE IN THE 00Z TAFS. A FEW LINGERING SHOWERS ARE POSSIBLE TUE AFTERNOON AND EVENING OTHERWISE DRIER WEATHER RETURNS TUESDAY NIGHT. VICINITY OF KSFO...S-SE WINDS EXPECTED TO TREND HIGHER NEAREST THE COLD FRONTAL PASSAGE VERY LATE TONIGHT/EARLY TUE MORNING. SE GUSTS UP TO 35 KNOTS LIKELY 06Z-10Z TIME-FRAME. HEAVY SHOWERS TONIGHT/EARLY TUE MORNING. POST FRONTAL WINDS TUESDAY NOT QUITE AS GUSTY AS PRE-FRONTAL WINDS. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...DETERIORATING WEATHER CONDITIONS ARE EXPECTED VERY LATE AT NIGHT. MOD-HEAVY DOWNPOURS EXPECTED WITH THE COLD FRONTAL PASSAGE EARLY TUE MORNING AS THE FRONT CONTINUES TO MOVE SE OVER THE CENTRAL COAST. ADDITIONAL PASSING SHOWERS LIKELY THROUGH THE REMAINDER OF TUESDAY AS THE AIR MASS ALOFT COOLS OFF APPRECIABLY. && .MARINE...AS OF 3:00 AM PDT TUESDAY...A COLD FRONT WILL MOVE THROUGH THE COASTAL WATERS EARLY TODAY PRODUCING GUSTY WINDS...RAIN AND THUNDERSTORMS. THE GUSTY WINDS WILL PRODUCE LOCALLY HAZARDOUS CONDITIONS. WINDS WILL DECREASE FROM NORTH TO SOUTH THROUGH THE DAY AS THE FRONT EXITS THE REGION WITH AN IMPROVING SEA STATE. NORTHWEST SWELL THROUGH THE PERIOD. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WINTER WEATHER ADVISORY...SANTA LUCIA RANGE THROUGH TONIGHT. SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 AM SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 8 AM SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 8 AM SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 8 AM SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 8 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 11 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 11 AM && $$ PUBLIC FORECAST: BELL AVIATION: CANEPA MARINE: MM VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1102 AM MDT TUE APR 7 2015 .UPDATE... ISSUED AT 1059 AM MDT TUE APR 7 2015 DRY SOUTHWEST FLOW ALOFT WILL RESULT IN ANOTHER WINDY DAY TODAY. GUSTY WINDS WERE ALREADY OBSERVED AT MANY VALLEY LOCATIONS AS ABUNDANT SUNSHINE MIXES OUT THE MORNING INVERSION. THIS MORNING`S 12Z NAM AND GFS MODELS SHOW THE 300 MB UPPER JET LIFTING INTO WY THIS AFTERNOON AS A SHORTWAVE OVER SRN NV EJECTS NORTHEAST ACROSS NW UT. WILL HOLD OFF ON VALLEY WIND ADVISORIES FOR TODAY WITH THE JET LIFTING NORTH AND THE 15Z HIGH-RESOLUTION HRRR AND RAP MODELS SHOWING WINDS BELOW THE 45 MPH GUST CRITERIA. BUT...GUSTS TO 35-40 MPH SHOULD BE FAIRLY COMMON FOR MANY VALLEYS OF ERN UT AND WRN CO AS DEEP MIXING PULLS STRONGER WINDS ALOFT TO THE SURFACE. RED FLAG WARNINGS FOR FIRE WEATHER LOOK ON TRACK FOR TODAY. THE UPPER LOW ALONG THE NRN CA COAST THIS MORNING MOVES INLAND TODAY TO ABOUT NE UT BY MIDDAY WEDNESDAY. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 445 AM MDT TUE APR 7 2015 DOWNSTREAM BLOCKING OVER THE CANADIAN MARITIMES WILL BE RELAXING OVER THE NEXT 48 HOURS. THIS WILL ALLOW ENERGY THAT HAS BEEN STALLED UPSTREAM TO MIGRATE THROUGH THE NORTHERN HALF OF THE CONUS THIS WEEK. THE STORM OF INTEREST TO OUR REGION REMAINS STUCK OFF THE OREGON COAST WITH NO SIGNIFICANT HEIGHT FALLS SEEN IN HAND ANALYSIS THIS MORNING. GOES DERIVED IMAGERY ALSO SUGGESTS PACIFIC MOISTURE TAP IS WEAK WITH THE BULK OF THE MOISTURE WELL TO OUR SOUTH AND HEADED TO THE PLAINS THROUGH THE WEEK. WATER VAPOR DOES INDICATE A STRONGER BRANCH OF THE JET ROUNDING THE BASE OF THE LOW IN CENTRAL CALIFORNIA THIS MORNING WHICH WILL HELP PULL THE SYSTEM ON SHORE THROUGH THE AFTERNOON...MOVING TO THE WESTERN UTAH BORDER BY WEDNESDAY. THIS WILL KEEP A TIGHT SOUTHWEST GRADIENT IN PLACE AND LEAD TO ANOTHER WINDY AND WARM DAY ACROSS THE CWA WHICH IS LIKELY TO CONTINUE OVERNIGHT AND KEEP MID-SLOPES MIXED AND POSSIBLY SOME VALLEYS FOR MILD LOW TEMPERATURES. QG FIELDS SUGGEST THE CORE OF THIS STORM WILL PASS TO OUR NORTH. HOWEVER DECENT LARGE SCALE ASCENT STILL OCCURS OVER OUR NORTHERN CWA THANKS TO A CYCLONICALLY CURVED JET TRANSLATING ACROSS WESTERN COLORADO CONCURRENTLY WITH THE TROUGH PASSAGE TOMORROW AFTERNOON. A COLD FRONT WILL BE REFLECTED AT THE SURFACE JUST AHEAD OF THE UPPER TROUGH PASSAGE AND HELP SOME LOW LEVEL CONVERGENCE. HOWEVER STILL FEEL MOISTURE...OR LACK THERE OF...IS THE MAIN INGREDIENT LACKING FOR A DECENT PRECIPITATION EVENT. MODEL PWAT OUTPUT REMAINS AOB ONE QUARTER OF AN INCH THROUGH THIS EVENT AND ENSEMBLE ANOMALIES HAVE SHOWN THIS DRIER THAN NORMAL TREND FOR THE PAST SEVERAL DAYS. THERE WILL BE SOME OCTANE IN THE FORM OF CONDITIONAL INSTABILITY WHICH MAY TEMPORARILY BOOST PRECIPITATION RATES BUT ANTICIPATE THIS WILL BE VERY LOCALIZED. THE BIGGER IMPACT WILL BE THE COOLER AIR DIVING IN BEHIND THE FRONT. SIMILAR TO LAST WEEK...TEMPERATURES WILL BE FALLING QUICKLY THROUGH THE LATE AFTERNOON AND EVENING AND SET THE STAGE FOR A COLD MID TO LATE WEEK PERIOD. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 445 AM MDT TUE APR 7 2015 H5 TROF AXIS WILL BE PASSING THROUGH THE FORECAST AREA WEDNESDAY NIGHT WITH STRONG CAA IN PLACE. SNOW LEVELS ARE EXPECTED TO DROP TO THE HIGHER VALLEY FLOORS OR AROUND THE 6K LEVEL...WITH BEST MOISTURE AND FORCING GENERALLY ALONG AND NORTH OF INTERSTATE 70. ACCUMULATING SNOWFALL WILL FAVOR THE EASTERN UINTA MOUNTAINS IN NORTHEAST UTAH AND THE PARK AND GORE RANGES IN NORTHERN COLORADO. LATEST NAM12 RUN IS SUPER AGGRESSIVE WITH SNOWFALL AMOUNTS ACROSS THE EASTERN UINTAS WHERE 30+ INCHES FORECAST. MODEL IS LIKELY SUFFERING WITH SOME CONVECTIVE FEEDBACK PROBLEMS AND WILL BASICALLY THROW THAT SOLUTION OUT. REMAINING MODELS MORE REASONABLE WITH ACCUMULATIONS IN THIS AREA WITH LATE SEASON ADVISORIES POSSIBLE WITH CONVECTIVELY ENHANCED ACCUMULATIONS UP TO 6 INCHES POSSIBLE FOR THE 24 HOUR PERIOD BEGINNING WEDNESDAY NIGHT. SYSTEM CLEARS OUT THURSDAY NIGHT WITH DRY CONDITIONS MOVING BACK IN. THE EXCEPTION WILL BE ACROSS THE FAR NORTHERN ZONES AS A WEAK SYSTEM TRACKS ENE ACROSS IDAHO AND NORTHERN WYOMING FRIDAY. TAIL END OF ENERGY MAY KICK OFF A FEW LIGHT SHOWERS OVER THE HIGHER TERRAIN ALONG THE WYOMING STATE LINE...OTHERWISE MINIMAL IMPACT ANTICIPATED. PATTERN FLATTENS OUT A BIT OVER THE WEEKEND AND INTO EARLY NEXT WEEK WITH ADDITIONAL ENERGY CLIPPING THE NORTHERN MOUNTAINS LATE SATURDAY AND SUNDAY. ELSEWHERE...DRY CONDITIONS ARE EXPECTED TO CONTINUE. TEMPERATURES WILL BE DROPPING QUICKLY WEDNESDAY NIGHT BEHIND THE FRONT...WITH FREEZING CONDITIONS POSSIBLE IN THE LOWER VALLEYS WHERE FRUIT TREES AND OTHER TENDER VEGETATION COULD BE THREATENED. AS A RESULT...WILL BE ISSUING A FREEZE WATCH FOR LATE WEDNESDAY NIGHT THROUGH EARLY THURSDAY MORNING. SIMILAR TEMPS POSSIBLE THURSDAY NIGHT...BEFORE TEMPS START MODIFYING OVER THE WEEKEND. BIG QUESTION WITH THE FREEZE WATCH IS THE AMOUNT OF CLOUD COVER THAT MAY LINGER OVER THE REGION. THIS WOULD LIMIT THE COLDEST TEMPS TO JUST A FEW HOURS AROUND SUNRISE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1059 AM MDT TUE APR 7 2015 GUSTY SOUTHWEST SURFACE WINDS AND TURBULENCE ALOFT WILL LIKELY BE THE MAIN AVIATION HAZARDS THIS AFTERNOON AND EVENING. EXPECT SOUTHWEST WINDS GUSTING BETWEEN 30-40 KTS AT TIMES UNTIL 03Z AT MANY VALLEY LOCATIONS INCLUDING THE TAF SITES. THE WIND MAY KICK UP SOME AREAS OF BLOWING DUST...ALTHOUGH WIDESPREAD RESTRICTIONS TO VISIBILITY. UPPER LEVEL LOW PRESSURE ALONG THE CA COAST WILL MOVE TO ABOUT NE UT BY MIDDAY WED. CLOUDS WILL INCREASE AFTER 06Z TONIGHT WITH BASES LOWERING WED MORNING BUT REMAINING VFR AT THE TAF SITES THROUGH 18Z. MVFR CONDITIONS IN SCT -SHSN ARE POSSIBLE OVER THE ERN UINTA MTNS AND THE NW CO MTNS AFTER 12Z WED. && .FIRE WEATHER... ISSUED AT 445 AM MDT TUE APR 7 2015 ...CRITICAL FIRE WEATHER CONDITIONS CONTINUE INTO WEDNESDAY... STRONG SOUTHWEST GRADIENT WINDS WILL CONTINUE ALOFT AND WILL EASILY MIX TO THE SURFACE AS TEMPERATURES REMAIN ABOVE NORMAL AND INSTABILITY STRONG. THE AIR MASS REMAINS VERY DRY WITH AFTERNOON HUMIDITY VALUES RANGING FROM 5 TO 15 PERCENT AND POOR RECOVERY EXPECTED AGAIN TONIGHT. SOME MOISTURE WILL SPREAD INTO THE AREA ON WEDNESDAY BUT COOLER AIR ARRIVING WILL BE THE MAIN FACTOR FOR HELPING INCREASE HUMIDITY. VIRGA IS LIKELY TO PROCEED ANY PRECIPITATION ON WEDNESDAY AND HELP CREATE LOCALLY STRONG WIND GUSTS THROUGH THE AFTERNOON. COLORADO ZONE 207 HAS THE POTENTIAL TO REACH CRITICAL FIRE WEATHER CONDITIONS FOR LOW HUMIDITY AND GUSTY WINDS AHEAD OF THE FRONT WEDNESDAY AFTERNOON. COOLER AND WETTER CONDITIONS ARE EXPECTED WEDNESDAY EVENING THROUGH THURSDAY NIGHT FAVORING THE NORTH. THE NEXT CHANCE OF SHOWERS ARRIVES SATURDAY NIGHT INTO MONDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING FOR COZ006-011-020. RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ200-202-203-205-207-290-292. UT...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING FOR UTZ022-027. && $$ UPDATE...JAD SHORT TERM...15 LONG TERM...JDC AVIATION...JAD FIRE WEATHER...TGJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT MON APR 6 2015 .UPDATE... ISSUED AT 903 PM MDT MON APR 6 2015 UPDATED FOR EXPIRATION OF RED FLAG WARNING. RH STILL VERY LOW MOST LOCATIONS...BUT WINDS HAVE DIMINISHED ENOUGH TO LET WARNING EXPIRE ON SCHEDULE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 245 PM MDT MON APR 6 2015 ...SHORT TERM CONCERN REMAINS CRITICAL FIRE WEATHER CONDITIONS... CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING A DEEP SOUTHWESTERLY FLOW PATTERN ACROSS THE REGION WITH AN UPPER LOW AND BROAD TROUGH JUST OFFSHORE THE PAC NORTHWEST COAST THROUGH THE WEST COAST AND GREAT BASIN REGION. WATER VAPOR IMAGERY ALSO INDICATING AN EMBEDDED SHORT WAVE TRANSLATING ACROSS THE GREAT BASIN AT THIS TIME. LATEST SFC OBSERVATIONS INDICATING A WELL MIXED ATMOSPHERE ACROSS THE AREA WITH BREEZY TO WINDY SOUTHWEST WINDS...WARM TEMPERATURES IN THE 70S TO LOWER 80S LOWER ELEVATIONS...50S AND 60S ACROSS THE HIGHER TERRAIN...DEW PTS MAINLY IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...ALL LEADING TO DANGEROUS FIRE WEATHER CONDITIONS BEING EXPERIENCED ACROSS ALL OF THE NON SNOW COVERED AREAS OF SOUTH CENTRAL AND SOUTHEAST COLORADO. HOWEVER...LOW LEVEL MOISTURE IS NOT TOO FAR AWAY WITH REGIONAL RADARS INDICATING A FINE LINE FROM NEAR DIA TO BURLINGTON AND INTO WEST CENTRAL KANSAS...WITH DEW PTS IN THE 20S...30S AND 40S NORTH AND EAST OF THE BOUNDARY INTO NORTHEASTERN COLORADO AND NORTHWESTERN KANSAS. TONIGHT AND TOMORROW...MODERATE TO STRONG SW FLOW ALOFT PROGGED TO CONTINUE ACROSS THE AREA THROUGH THE PERIOD WITH GREAT BASIN EMBEDDED WAVE CONTINUING TO TRANSLATE NORTH AND EAST ACROSS THE NORTHERN ROCKIES TONIGHT AND ANOTHER SHORT WAVE PROGGED TO MOVE INTO THE GREAT BASIN REGION THROUGH THE DAY TOMORROW. FIRST WAVE LOOKS TO HELP PUSH LOW LEVEL MOISTURE GRADIENT/FRONT SOUTH AND WEST ACROSS PORTIONS OF THE PALMER DVD AND NORTHERN PORTIONS OF THE SE PLAINS TONIGHT WITH THE HRRR THE MOST AGGRESSIVE PUSHING MID 40 DEW PTS AND STRATUS WELL INTO KIOWA AND PROWERS COUNTIES OVERNIGHT...WHICH MAY BE A TAD OVERDONE. FURTHER WEST...WILL LIKELY SEE POOR RH RECOVERY WITH LOWS SIMILAR TO LAST NIGHTS. THIS BOUNDARY LOOKS TO MIX OUT THROUGH THE LATE MORNING AND EARLY AFTERNOON TOMORROW AS LEE TROUGH STRENGTHENS ACROSS THE EASTERN PLAINS AHEAD OF THE NEXT EMBEDDED SHORT WAVE. THIS ALL POINTS TO ANOTHER DAY OF HIGH FIRE DANGER...ESPECIALLY FOR AREAS ALONG THE I- 25 CORRIDOR AND BACK WEST ACROSS THE REST OF THE EASTERN MTS TO THE CONTDVD. WITH THAT SAID...HAVE UPGRADED AND EXPANDED A RED FLAG WARNING FOR TOMORROW FROM NOON TO 8 PM FOR ALL OF THE NON SNOW COVERED MTS...THE HIGH MT VALLEY AND THROUGH THE I-25 CORRIDOR. I DID NOT INCLUDE THE FAR SE PLAINS WITH MARGINAL WINDS...THOUGH IF DEEP ENOUGH MIXING CAN OCCUR...COULD SEE RED FLAG CONDITIONS THERE AS WELL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 245 PM MDT MON APR 6 2015 ...DRY AND WINDY WEATHER CONTINUES... A SERIES OF PROGRESSIVE TROUGHS WILL IMPACT OUR AREA OVER THE NEXT SIX TO TEN DAYS...UNFORTUNATELY NONE OF THEM LOOK VERY ORGANIZED AND IT LOOKS LIKE THERE WILL BE MORE WIND THAN PRECIPITATION FROM THIS PATTERN. THE ONLY OPTIMISTIC THING THAT CAN BE SAID IS THAT THE MODELS ARE STRUGGLING WITH THE PATTERN...SO THERE IS TIME FOR IT TO CHANGE. WEDNESDAY STILL LOOKS LIKE A DAY OF POTENTIALLY EXTREME FIRE WEATHER. WITH INCREASING WRLY FLOW ALOFT...WILL SEE VERY LOW RH OVER MOST OF THE AREA...AND ANOTHER ROUND OF STRONG-GUSTY WINDS IN THE AFTERNOON AND EARLY EVE. HAVE HOISTED A FIRE WX WATCH FOR MOST OF THE CWA. ONLY AREAS THAT MIGHT ESCAPE ARE THE PIKES PEAK REGION AND THE CENTRAL MTS. TEMPS ALOFT WILL BE FALLING...SO DEPENDING ON THE SPEED OF THE COLD FRONT THE RH VALUES FOR THE NRN AND CENTRAL MTN AREAS MAY BE HIGH ENOUGH TO PRECLUDE RED FLAG. BUT IT WILL BE ANOTHER DAY OF HIGH FIRE DANGER FOR THE PLAINS. EXTREME NERN CORNER...BASICALLY KIOWA COUNTY...WILL BE A BIT SLOWER TO MIX OUT DUE TO SOME MORNING LOW CLOUDS...BUT BY MID TO LATE AFTERNOON MOST OF THE PLAINS SHOULD BE ON THE BREEZY-WINDY SIDE. MODELS ARE NOW ALL ON BOARD WITH A MORE NORTHERLY TRACK FOR THE LATE WED-THU SYSTEM. AS EXPECTED...THE OUTLIER ECMWF HAS FALLEN INTO LINE WITH THE GFS...AND THE NAM-GFS SOLUTION HAS COME TOGETHER WITH A LOW THAT TRACKS THROUGH WY. SO...PRECIP CHANCES NOT LOOKING VERY GOOD FOR US RIGHT NOW. STILL LOOKS LIKE THE PIKES PEAK REGION AND CENTRAL MTS N OF HGWY 50 WILL GET SOME SNOW...PERHAPS A COUPLE INCHES. BUT ELSEWHERE...HAVE TRIMMED BACK THE LOW POPS AND WILL KEEP THEM SILENT FOR NOW. TEMPS OVER THE PLAINS ON THU SHOULD BE MAINLY IN THE UPPER 50S-LOWER 60S. RIDGING ON FRIDAY SHOULD MITIGATE FIRE WX CONCERNS...AS WINDS DIE DOWN FOR A DAY OR SO. BUT IT STILL LOOKS DRY...AS DOES SATURDAY WHEN SWRLY FLOW PICKS UP ONCE AGAIN AND LEADS TO MORE FIRE WX CONCERNS. NEXT SYSTEM IS STILL BEING HANDLED QUITE DIFFERENTLY BY THE GLOBAL MODELS. MODELS ARE ALL SHOWING A SPLIT SYSTEM...BUT THE GFS HAS A WEAKER CUTOFF...AND BROAD DISORGANIZED CUTOFF LOW OVER NRN CO AND WY BY MONDAY. THE ECMWF HAS A MORE ZONAL PATTERN TO OUR NORTH...BUT KEEPS THE SRN CUTOFF SYSTEM TOO FAR SOUTH TO IMPACT OUR AREA. NEITHER 12Z SOLUTION WOULD BRING US MUCH PRECIPITATION...WE JUST CAN NOT GET A BREAK FROM THIS DISORGANIZED PATTERN! STILL...IT LOOKS LIKE A CONTINUED PERIOD OF UNSETTLED WEATHER WITH SHOWERS PROBABLE FOR AT LEAST THE MTN AREAS. ROSE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1112 PM MDT MON APR 6 2015 VFR CONDITIONS IN COMBINATION WITH GUSTY WINDS AT TIMES ARE ANTICIPATED OVER THE KALS...KCOS AND KPUB TAF SITES INTO TUESDAY EVENING AS DRY SOUTHWESTERLY UPPER FLOW REMAINS OVER THE REGION. && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR COZ222-224>237. RED FLAG WARNING FROM NOON TO 8 PM MDT TUESDAY FOR COZ220>230- 233. && $$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
358 AM EDT TUE APR 7 2015 .SYNOPSIS... A BACKDOOR COLD FRONT WILL PROGRESS SOUTHWARD THROUGH THE AREA TODAY. THIS FRONT WILL STAY TO OUR SOUTH TONIGHT THROUGH THURSDAY. MEANWHILE, HIGH PRESSURE BUILDING IN FROM EASTERN CANADA WILL BE ACCOMPANIED BY PERSISTENT ONSHORE FLOW IN THE MID-ATLANTIC REGION. THE SAME FRONTAL BOUNDARY IS EXPECTED TO RETURN BACK NORTHWARD AS A WARM FRONT ON FRIDAY BEFORE A COLD FRONT MOVES THROUGH FRIDAY NIGHT. HIGH PRESSURE BUILDS INTO THE REGION THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CDFNT WILL WORK ITS WAY SWD OVER THE REGION THRU THE COURSE OF THE DAY TODAY AND BRING SHOWERS WITH IT. LATEST RADAR SHOWED SOME PRECIP W OF BALTIMORE WITH SOME DEVELOPING IN SRN NJ AND ADDITIONAL PRECIP OVER THE POCONOS. HRRR GUID IS ONLY PICKING UP THE LARGER AREA W OF BALTIMORE REALLY WELL AND WANTS TO LESSEN IT/DISSIPATE IT AS IT MOVES EWD. HRRR STILL WANTS TO HOLD OFF THE BULK OF THE PRECIP, AS DO THE REST OF THE MDLS UNTIL AFTER DAYBREAK. STLT IMAGERY AND SFC OBS STILL HAVE HIGH TO MID LEVEL CLOUDS AND THE AMS IS RELATIVELY DRY, SO HAVE GONE WITH THE TREND AND HAVE PLACED SOME LOW POPS ERLY WAND HIGHER POPS A BIT LATER THAN THE PREV FCST. OVERALL, TODAY LOOKS TO BE A CLOUDY AND WARM DAY WITH GENLY PDS OF LIGHT RAIN. THE WIND WILL START OFF SWLY IN THE MRNG AND BECOME MORE NELY LATER IN THE DAY, DEPENDING ON LOCATION, AS THE FRONT PASSES. ONCE THE WIND SHIFTS, YOU WILL KNOW IT AS SW WIND IS GENLY WARM AND NE IS NOT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... THE RAIN STAYS WITH US EARLY TONIGHT BEFORE ENDING. IT WILL LIKELY BECOME MORE STRATIFORM AND COULD EVEN BE MORE OF A DRIZZLE. IT LOOKS TO BE A FAIRLY DREARY NIGHT WITH A NE WIND AND WHATEVER IS FALLING FROM THE SKY. PRECIP SHUD COME TO AN END LATE. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... A STRONG (BETWEEN 1035-1040 MB) SURFACE HIGH WILL BUILD EASTWARD ACROSS QUEBEC ON WEDNESDAY. A CLASSIC CAD SETUP WILL BE IN PLACE FOR THE MIDWEEK, INDICATIVE BY THE U-SHAPED MSLP PATTERN AS HIGH PRESSURE RIDGES SOUTHWARD DOWN INTO MID-ATLANTIC REGION. FORECAST MODEL SOUNDINGS PICK UP ON THE SHALLOW WEDGE OF COLD AIR NEAR THE SURFACE THAT REMAINS TRAPPED ON THE EASTERN SIDE OF THE APPALACHIANS. IN ADDITION TO THE BELOW NORMAL TEMPS, THIS PATTERN WILL RESULT IN PLENTY OF CLOUDS ALONG WITH PERIODS OF LIGHT RAIN AND DRIZZLE WEDNESDAY AND THURSDAY. SOME OF THE COLDER MODEL GUIDANCE IS SHOWING THE POTENTIAL FOR LIGHT FREEZING RAIN IN NORTHEAST PA AND FAR NORTHWEST NJ OVERNIGHT WEDNESDAY INTO THE EARLY MORNING THURSDAY. THERE IS STILL UNCERTAINTY THAT TEMPS FALL BELOW FREEZING AND THAT ICE ACCRETION WOULD OCCUR IN THESE NORTHERN MOST ZONES. DENSE CLOUD COVER SHOULD MINIMIZE RADIATIONAL COOLING AND CAA WILL BE ABSENT UNDER AN EAST TO SOUTHEAST FLOW IN THE BOUNDARY LAYER. EVEN THE COLDEST GUIDANCE HAS TEMPS HOVERING AROUND 32 DEGREES, WHICH WOULD BE DIFFICULT FOR ICE TO ACCRETE ON ANYTHING OTHER THAN ELEVATED SURFACES (TREES/ROAD SIGNS/POWERLINES) GIVEN HOW WARM THE GROUND IS. NEVERTHELESS, THE NAM AND ABOUT HALF OF THE SREF MEMBERS SUPPORT FREEZING RAIN ALONG AND NORTH OF I-80 LATE WEDNESDAY NIGHT, SO IT WOULDN`T BE PRUDENT TO COMPLETELY DISMISS THE POTENTIAL OF A LIGHT GLAZE. SOUTHWEST FLOW WILL STRENGTHEN AHEAD OF AN APPROACHING COLD FRONT ON FRIDAY. A MAJORITY OF THE LATEST MODEL GUIDANCE SHOWS THE CAD WEDGE ERODING AND THE PRE-FRONTAL WARM SECTOR BECOMING ESTABLISHED OVER THE FORECAST AREA. AS STATED BY YESTERDAY`S DAY SHIFT FORECASTER, THE MODELS TEND TO BE TOO AGGRESSIVE WITH THE PROGRESSION OF WARM FRONTS THIS TIME OF YEAR DUE TO THE PRESENCE OF THE COLD OCEAN TEMPS. IN SOME CASES, THE CAD WEDGE DOES NOT ERODE UNTIL AFTER THE COLD FROPA WHICH WOULDN`T BE UNTIL FRIDAY EVENING. THERE WILL LIKELY BE A NOTICEABLE NORTH TO SOUTH TEMP GRADIENT ON FRIDAY WITH HIGHS IN THE 70S SOUTH OF THE WARM FRONT AND 60S FARTHER NORTH (EXCEPT 50S IN THE POCONOS/NORTHWEST NJ WHERE THE HILLY TERRAIN WILL MAKE IT MORE DIFFICULT TO SCOUR OUT THE COLD). THERE MAY BE AN OPPORTUNITY FOR THUNDERSTORMS TO DEVELOP IN THE WARM SECTOR JUST AHEAD OF THE COLD FRONT DURING THE PEAK HEATING HOURS ON FRIDAY. SPC OUTLOOK FROM YESTERDAY MORNING HAD PLACED A PORTION OF THE DELMARVA IN A 15 PERCENT PROBABILITY FOR SEVERE STORMS ON FRIDAY. COOLER AIR WILL MOVE BEHIND THE COLD FRONT LATE FRIDAY NIGHT. THE AIRMASS WILL NOT BE EXTREMELY COLD SO TEMPS SHOULD BE NEAR NORMAL THIS WEEKEND. CANNOT RULE OUT A BRIEF SHOWER IN THE POCONOS WITH THE PASSAGE OF AN UPPER TROUGH ON SATURDAY. OTHERWISE THE WEEKEND SHOULD BE DRY AS HIGH PRESSURE BUILDS OVERHEAD. HIGH PRESSURE MOVES OFFSHORE BY MONDAY. DESPITE RISING HEIGHTS AND SOUTHERLY FLOW/WAA ALOFT, WARMING AT THE SURFACE WOULD BE MODERATED BY THE ONSHORE FLOW FROM THE COOLER WATERS. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS ARE HANGING ON LONGER THAN ANTICIPATED ERLY THIS MRNG AND THE CURRENT FCST MAY BE TOO PESSIMISTIC. ITS PSBL THAT WE KEEP THE VFR THRU DAYBREAK (OR EVEN LONGER IN SOME AREAS). HOWEVER, THE OVERALL TREND IS STILL DOWNWARD LATER THIS MORNING, AS A FRONT MOVES FROM N TO S ACRS THE AREA. CONDS WILL DROP FROM VFR TO MVFR AND THEN TO IFR. SOME LIFR CAN NOT BE RULED OUT. ONCE CONDS DROP, THEY WILL STAY DOWN THRU THE DAY AND INTO TONIGHT. VSBYS MAY IMPROVE TO VFR BY MIDNIGHT OR SHORTLY THEREAFTER, BUT STILL EXPECT THE LOW CIGS TO STICK AROUND. WIND WILL START OUT FROM THE SW, GENLY LESS THAN 10 KTS, BUT WILL SHIFT TO THE NE AND GUST TO AROUND 20 KT BY LATE AFTN ERLY EVE. OUTLOOK... WEDNESDAY THROUGH THURSDAY NIGHT...BREEZY NE WINDS WINDS WILL SUBSIDE A BIT AFTER WEDNESDAY. THE ONSHORE FLOW WILL RESULT IN A PROLONGED STRETCH OF LOW CLOUDS AND PERIODS OF RA/DZ. EXPECT IFR CIGS FOR MAJORITY OF THE PERIOD BUT DO SEE SOME OPPORTUNITY FOR BRIEF IMPROVEMENTS TO MVFR DURING THE AFTERNOON HOURS EACH DAY. ABOVE NORMAL CONFIDENCE. FRIDAY...IFR CIGS IN THE MORNING IMPROVE TO MVFR AND THEN VFR FROM SOUTH TO NORTH DURING THE DAY. CONFIDENCE IN THIS IMPROVEMENT HIGHEST IN OUR SOUTHERN TERMINALS. SW WINDS WILL BE GUSTY. SHOWERS AND POSSIBLY A THUNDERSTORMS WITH A COLD FROPA FRIDAY AFTN/EVE. SATURDAY...VFR AND BREEZY NW WINDS. && .MARINE... THE SCA IN EFFECT FOR ERLY THIS MRNG HAS BEEN CANCELLED AS CONDS REMAIN BELOW CRITERIA. CONDS WILL REMAIN BELOW CRITERIA FOR TODAY AND MOST OF TONIGHT. THE WIND WILL SHIFT FROM SW TO NE BE LATE AFTN/ERLY EVE N AND OVERNIGHT S. AND WIND SPEED WILL INCREASE TO NEAR ADVY CRITERIA BY THE END OF THE PD WITH SEAS RESPONDING IN KIND. OUTLOOK... WEDNESDAY...POTENTIAL FOR GALES, PARTICULARLY IN THE COASTAL WATERS ADJACENT TO CENTRAL NJ AND DURING THE MORNING HOURS. A GALE WATCH WAS ISSUED FOR OUR TWO NORTHERN MOST ZONES. ISSUED A SCA FOR OUR COASTAL ZONES FARTHER SOUTH WHERE NELY WINDS WILL BE SLIGHTLY WEAKER. WENT 1-2 FT ABOVE WAVEWATCH GUIDANCE FOR WAVE HEIGHTS BASED ON KNOWN MODEL BIAS IN NE FLOW. WEDNESDAY NIGHT AND THURSDAY...NELY WINDS DIMINISH BUT MAY STILL BE NEAR 25 KT OFF THE NJ COAST. SCA STILL EXPECTED TO PERSIST FOR ALL COASTAL ZONES WITH CHOPPY SEAS OF 5-8 FT. FRIDAY...SWLY WINDS STRENGTHEN AND SCA CONDITIONS EXPECTED BY AFTERNOON. 40-50 KT WINDS ARE FORECAST TO DEVELOP NOT TOO FAR ALOFT BUT VERY WARM AIR MOVING ATOP THE COLDER WATERS DO NOT FAVOR THESE WINDS TO MIX DOWN TO THE SURFACE. FRIDAY NIGHT AND SATURDAY...WINDS BECOME NWLY BEHIND COLD FROPA SHOULD GUST TO UNDER 25 KT. SEAS 4-6 FT FRIDAY NIGHT WILL SUBSIDE TO 4 FT OR LESS BY SATURDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR ANZ452>455. GALE WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR ANZ450-451. && $$ SYNOPSIS...KLEIN NEAR TERM...NIERENBERG SHORT TERM...NIERENBERG LONG TERM...KLEIN AVIATION...KLEIN/NIERENBERG MARINE...KLEIN/NIERENBERG
AREA FORECAST DISCUSSION
NWS MIAMI FL
138 PM EDT TUE APR 7 2015 .AVIATION... HIGH PRESSURE CONTINUES TO KEEP THE WEATHER QUIET ACROSS SOUTH FLORIDA. ALTHOUGH, THERE MAY BE SOME ISOLATED SHOWERS OVER THE WESTERN HALF, NEAR KAPF. THERE IS ALSO A VERY SLIGHT POSSIBILITY THAT A FEW OF ANY SHOWERS THAT ARE ABLE TO DEVELOP, MAY TURN INTO A THUNDERSTORM. HOWEVER, THE UNCERTAINTY IS LOW ENOUGH THAT NO MENTION OF EVEN THE SHOWERS ARE IN THE TAFS AT THIS TIME. SKIES SHOULD BECOME MOSTLY CLEAR TO CLEAR TONIGHT. TOMORROW WILL SEE ANOTHER ROUND OF AFTERNOON CLOUDS DEVELOP. && .PREV DISCUSSION... /ISSUED 1118 AM EDT TUE APR 7 2015/ UPDATE... JUST MADE A QUICK CHANGE TO ADD A SLIGHT CHANCE OF THUNDER OVER THE INTERIOR AND WEST COAST FOR LATE THIS AFTERNOON AND EARLY EVENING. THIS BASED ON CLOSER EXAMINATION TO THE MORNING SOUNDING AND DECIDED THE AIRMASS IS SHOWING ENOUGH INSTABILITY THAT CANNOT RULE OUT A POSSIBLE LIGHTNING STRIKE. PREV DISCUSSION... /ISSUED 902 AM EDT TUE APR 7 2015/ UPDATE... CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION. KOB PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/ DISCUSSION... ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY. SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST. SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE 10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE ALSO POSSIBLE FOR THE EAST COAST. A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE LIMITED. MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF COAST. AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS THEN RETURNING TO THE REGION. MARINE... AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 72 85 73 85 / 10 10 0 10 FORT LAUDERDALE 73 83 73 84 / 10 10 0 10 MIAMI 72 85 73 86 / 10 10 0 10 NAPLES 69 89 68 89 / 20 20 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...30/KOB LONG TERM....84/AK AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
1118 AM EDT TUE APR 7 2015 .UPDATE... JUST MADE A QUICK CHANGE TO ADD A SLIGHT CHANCE OF THUNDER OVER THE INTERIOR AND WEST COAST FOR LATE THIS AFTERNOON AND EARLY EVENING. THIS BASED ON CLOSER EXAMINATION TO THE MORNING SOUNDING AND DECIDED THE AIRMASS IS SHOWING ENOUGH INSTABILITY THAT CANNOT RULE OUT A POSSIBLE LIGHTNING STRIKE. && .PREV DISCUSSION... /ISSUED 902 AM EDT TUE APR 7 2015/ UPDATE... CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION. KOB PREV DISCUSSION... /ISSUED 811 AM EDT TUE APR 7 2015/ AVIATION... HIGH PRESSURE WILL BE BUILDING OVER THE AREA, WITH THE CENTER NEAR BERMUDA. THIS WILL KEEP THE GENERAL FLOW OUT OF THE EAST TODAY. SOME ISOLATED SHOWERS MAY BE POSSIBLE ALONG THE GULF COAST. A WEAK UPPER LEVEL TROUGH WILL MOVE OVER SOUTH FLORIDA TONIGHT, BRINGING AT LEAST AN INCREASE IN CLOUD COVER. SOME MODELS ARE INDICATING THE CIGS COULD BE BORDERING ON IFR AT SOME OF THE ATLANTIC TAF SITES, BEGINNING AFTER 02Z. HOWEVER, WITH LOW CONFIDENCE OF THE IFR CONDITIONS, KEPT THE TAF STATING VFR AT THIS TIME. PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/ DISCUSSION... ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY. SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST. SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE 10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE ALSO POSSIBLE FOR THE EAST COAST. A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE LIMITED. MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF COAST. AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS THEN RETURNING TO THE REGION. MARINE... AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 72 85 73 / 10 10 10 0 FORT LAUDERDALE 83 73 83 73 / 10 10 10 0 MIAMI 86 72 85 73 / 10 10 10 0 NAPLES 87 69 89 68 / 20 20 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...10/CD LONG TERM....10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
902 AM EDT TUE APR 7 2015 .UPDATE... CURRENT ANALYSIS SHOWS MID/UPPER LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND SURFACE RIDGE FROM THE SOUTHEAST STATES INTO THE ATLANTIC. DO NOT PLAN TO MAKE ANY MAJOR CHANGES WITH THE MORNING UPDATES. THE 12Z MFL SOUNDING SHOWS MARGINAL INSTABILITY BUT STILL QUITE DRY WITH PWAT AT LESS THAN 1.5" WHICH IS SLIGHTLY ABOVE THE EARLY APRIL AVERAGE OF AROUND 1.2". SO THIS COMBINED WITH PLENTY OF DIURNAL HEATING ALONG WITH A WELL ESTABLISHED LOW LEVEL SOUTHEAST FLOW WILL RESULT IN A FEW LATE AFTERNOON/EARLY EVENING SHOWERS OVER THE INTERIOR AND WEST COAST. THE HRRR SHOWS THIS ACTIVITY BEGINNING AROUND 19Z AND PERSISTING UNTIL 01-02Z THIS EVENING. THIS SEEMS REASONABLE BASED ON THE ABOVE DISCUSSION. KOB && .PREV DISCUSSION... /ISSUED 811 AM EDT TUE APR 7 2015/ AVIATION... HIGH PRESSURE WILL BE BUILDING OVER THE AREA, WITH THE CENTER NEAR BERMUDA. THIS WILL KEEP THE GENERAL FLOW OUT OF THE EAST TODAY. SOME ISOLATED SHOWERS MAY BE POSSIBLE ALONG THE GULF COAST. A WEAK UPPER LEVEL TROUGH WILL MOVE OVER SOUTH FLORIDA TONIGHT, BRINGING AT LEAST AN INCREASE IN CLOUD COVER. SOME MODELS ARE INDICATING THE CIGS COULD BE BORDERING ON IFR AT SOME OF THE ATLANTIC TAF SITES, BEGINNING AFTER 02Z. HOWEVER, WITH LOW CONFIDENCE OF THE IFR CONDITIONS, KEPT THE TAF STATING VFR AT THIS TIME. PREV DISCUSSION... /ISSUED 323 AM EDT TUE APR 7 2015/ DISCUSSION... ABOVE NORMAL HIGH AND LOW TEMPERATURES ARE EXPECTED EACH DAY THROUGH THE FORECAST PERIOD...WITH HIGHS IN THE 80S TO LOW 90S AND LOWS IN THE MID 60S TO MID 70S. SHOWERS ARE POSSIBLE TODAY AND WEDNESDAY FOR THE GULF COAST...WITH DRY CONDITIONS ON THURSDAY. SEA BREEZE SHOWERS AND THUNDERSTORMS RETURN TO THE REGION FRIDAY THROUGH THE WEEKEND...ESPECIALLY INTERIOR AND WEST. SHOWERS OVER THE GULF COAST AND ATLANTIC WATERS HAVE DIMINISHED...BUT A FEW SPRINKLES ARE POSSIBLE ALONG THE EAST COAST OVER THE NEXT COUPLE HOURS. EASTERLY WINDS TODAY WILL BE IN THE 10-15 MPH RANGE AS SURFACE HIGH PRESSURE SETTLES OVER THE WESTERN ATLANTIC. A WEAK SHORTWAVE WILL SLIDE SOUTHEAST DOWN THE PENINSULA THIS AFTERNOON AND INTO THE REGION THIS EVENING. THIS MAY ENHANCE SHOWERS ALONG THE SEA BREEZE THIS AFTERNOON...BUT THE BEST LIFT WILL BE ACROSS CENTRAL FLORIDA SO WILL LEAVE MENTION OF THUNDERSTORMS OUT TODAY. LOW LEVEL MOISTURE WILL INCREASE IN THE EVENING FOR THE EAST COAST...AND WITH THE SHORTWAVE MOVING INTO THE REGION...A FEW SHOWERS ARE POSSIBLE. SOME LOWER CEILINGS ARE ALSO POSSIBLE FOR THE EAST COAST. A SHORTWAVE TROUGH WILL MOVE INTO THE INTERMOUNTAIN WEST ON WEDNESDAY...AND THE MID/UPPER RIDGE OVER THE GULF WILL AMPLIFY ACROSS THE EASTERN SEABOARD. A FEW SHOWERS ARE STILL POSSIBLE ALONG THE GULF COAST SEA BREEZE...BUT OVERALL ACTIVITY WILL BE LIMITED. MID/UPPER LEVEL RIDGING WILL THEN TAKE OVER THE WEATHER ON THURSDAY. THE SHORTWAVE TROUGH WILL LIFT NORTHEASTWARD INTO THE GREAT LAKES ON FRIDAY...AND THE MID/UPPER LEVEL RIDGE WILL SHIFT INTO THE WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL PUSH EASTWARD...AND SOUTHEAST LOW LEVEL FLOW WILL ALLOW DEEPER MOISTURE TO PUSH INTO THE REGION. SO SCATTERED SHOWERS AND STORMS ARE POSSIBLE ALONG THE SEA BREEZE CONVERGENCE ACROSS THE INTERIOR AND GULF COAST. SIMILAR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE BEST CHANCE OF SHOWERS AND STORMS ACROSS THE INTERIOR AND GULF COAST. AN UPPER TROUGH WILL THEN DIG ACROSS THE MIDDLE OF THE COUNTRY SUNDAY INTO SUNDAY NIGHT...WITH THE MID/UPPER RIDGE AMPLIFYING ACROSS THE REGION ONCE AGAIN INTO EARLY NEXT WEEK. SEA BREEZE SHOWERS AND STORMS ARE POSSIBLE ON SUNDAY...WITH DRIER CONDITIONS THEN RETURNING TO THE REGION. MARINE... AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 72 85 73 / 10 10 10 0 FORT LAUDERDALE 83 73 83 73 / 10 10 10 0 MIAMI 86 72 85 73 / 10 10 10 0 NAPLES 87 69 89 68 / 20 20 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 AM EDT TUE APR 7 2015 .AVIATION... EASTERLY WINDS AROUND 10 KNOTS WILL CONTINUE OVERNIGHT TONIGHT ALONG THE EAST COAST...WITH LIGHT AND VARIABLE WINDS AT KAPF. EARLIER RAINFALL AT KAPF MAY LEAD TO LOWER CIGS OVERNIGHT. EASTERLY FLOW WILL INCREASE TO 12-15 KNOTS DURING THE DAY ON TUESDAY. ANOTHER SUBTLE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE PENINSULA LATE IN THE DAY ON TUESDAY...WHICH MAY LEAD TO SHOWERS MAINLY NORTH OF KAPF. THERE WILL BE AN INCREASE IN LOW LEVEL MOISTURE TOWARDS THE EAST COAST AROUND 00Z...AND MVFR CIGS ARE POSSIBLE NEAR THE END OF THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 830 PM EDT MON APR 6 2015/ UPDATE... CONVERGENCE BETWEEN EASTERLIES AND THE GULF COAST SEA BREEZE, ALONG WITH A VERY SUBTLE WAVE DROPPING SOUTHEAST FROM THE NORTHEASTERN GULF, PROVIDED JUST ENOUGH LIFT FOR SHOWERS ALONG INLAND COLLIER THIS EVENING, MUCH LESS THAN WHAT THE HRRR HAS PREDICTED. THIS CLUSTER COULD MAKE IT TO PART OF NAPLES OVER THE NEXT FEW HOURS WHILE WEAKENING. OTHERWISE, COASTAL CONVERGENCE, MINIMAL DIRECTIONAL SHEAR THROUGH H7, AND EAST WINDS 10-15KT WILL BE ENOUGH FOR AT LEAST SLT CHC POPS OFFSHORE AND ALONG THE ENTIRE EAST COAST FOR THE REST OF TONIGHT. PREV DISCUSSION... /ISSUED 742 PM EDT MON APR 6 2015/ AVIATION... ISOLATED SHOWERS REMAIN ACROSS THE ATLANTIC WATERS EARLY THIS EVENING. AS EASTERLY FLOW PERSISTS THROUGH THE NIGHT...SOME OF THESE SHOWERS COULD BRIEFLY AFFECT THE EAST COAST SITES BUT NOT CONFIDENT ENOUGH TO MENTION IN TAFS. MAINLY DRY CONDITIONS EXPECTED ON TUESDAY WITH EASTERLY FLOW PREVAILING. PREV DISCUSSION... /ISSUED 237 PM EDT MON APR 6 2015/ SHORT TERM (TONIGHT-WEDNESDAY NIGHT)... THE SHORT TERM PERIOD LOOKS RATHER SUBDUED AS A MID/UPPER LEVEL RIDGE AXIS REMAINS ACROSS THE EASTERN GULF OF MEXICO. THIS RIDGE WILL AMPLIFY LATE TUESDAY INTO WEDNESDAY IN RESPONSE TO A STRONG TROUGH MOVING ONTO THE NORTHERN CALIFORNIA COAST AND INTO THE CENTRAL ROCKIES. A SURFACE HIGH PRESSURE RIDGE CURRENTLY LOCATED ACROSS THE SOUTHEAST STATES WILL ALSO MOVE LITTLE PROVIDING SOUTH FLORIDA WITH A GENERAL LOW LEVEL EAST TO SOUTHEAST FLOW. FORECAST SOUNDINGS SUGGEST THAT THIS PATTERN WILL BE FAVORABLE FOR A FEW ATLANTIC SHOWERS TO MOVE ONSHORE ALONG THE SOUTHEAST COAST THROUGH THIS PERIOD WITH A FEW AFTERNOON SHOWERS OVER THE INTERIOR AND WEST COAST. LONG TERM (THURSDAY-MONDAY)... THE AMPLIFIED MID LEVEL RIDGE WILL CONTINUE THROUGH FRIDAY AND THEN WEAKEN AND SHIFT BACK TO THE SOUTH OVER THE WEEKEND AS A POTENT TROUGH MOVES THROUGH THE CENTRAL PLAINS. AS THIS PATTERN SHIFT OCCURS, FORECAST SOUNDINGS SHOW SOME MOISTURE INCREASE WITH PWAT CLIMBING TO AROUND 1.5" WHICH IS RUNNING ABOVE NORMAL FOR GOING INTO THE MIDDLE OF APRIL. IN ADDITION, THERE WILL ALSO BE SOME DESTABILIZATION OCCURRING AS 500MB TEMPERATURES COOL SLIGHTLY. THE CENTRAL PLAINS TROUGH THEN LIFTS TO THE NORTHEAST EARLY NEXT WEEK WITH THE RIDGE AMPLIFYING TO THE NORTH ONCE AGAIN. MARINE... AN EAST TO SOUTHEAST WIND WILL CONTINUE THROUGH THE PERIOD WITH SEAS OF 2-4 FEET OVER THE ATLANTIC WATERS AND 1-2 FEET IN THE GULF WATERS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 83 72 85 71 / 10 10 10 0 FORT LAUDERDALE 83 73 83 73 / 10 10 10 0 MIAMI 85 73 86 73 / 10 10 10 0 NAPLES 88 70 88 70 / 10 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1042 PM EDT WED APR 8 2015 .SYNOPSIS... CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW MOISTURE. MODERATE INSTABILITY LINGERING UNTIL AROUND 100 AM SUPPORTS A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED WITH THE SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED DEVELOPMENT. USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY IN THE MIDDLE 60S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE. THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S IN THE SOUTHEASTERN MIDLANDS. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH PRESSURE DOMINATING IN THE LOWER LEVELS. EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH. TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND NEXT WEEK...AND ABOVE NORMAL LOWS. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS EXPECTED IN EARLY MORNING FOG ON THURSDAY. SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES. WINDS WILL ONCE AGAIN BE LIGHT FROM THE SOUTHWEST/SOUTH LATE THIS EVENING. MODELS SHOW POTENTIAL FOR FOG DEVELOPMENT EARLY THURSDAY MORNING WITH LIGHT/CALM WIND...LOW LEVEL MOISTURE IN PLACE...AND DRY AIR ALOFT. WILL MENTION FOG AT AGS/DNL/OGB FROM 10Z THRU 14Z AND WILL CONTINUE TO UPDATE AS CONFIDENCE INCREASES. VSBYS AT AGS MAY DIP TO IFR LEVELS BEFORE 14Z THURSDAY. DAYTIME HEATING AND MIXING SHOULD ALLOW VFR CONDITIONS TO RETURN BY 14Z WITH MOSTLY SUNNY SKIES/PARTLY CLOUDY THROUGH THE END OF THE TAF PERIOD. SCATTERED CONVECTION POSSIBLE LATE THURSDAY AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO MENTION AT ANY OF THE TAF SITES AT THIS TIME. EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND SATURDAY MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1041 PM EDT WED APR 8 2015 .SYNOPSIS... CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW MOISTURE. MODERATE INSTABILITY LINGERING INTO THE EVENING SUPPORTS A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED WITH THE SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED DEVELOPMENT. USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY IN THE MIDDLE 60S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE. THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S IN THE SOUTHEASTERN MIDLANDS. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH PRESSURE DOMINATING IN THE LOWER LEVELS. EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH. TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND NEXT WEEK...AND ABOVE NORMAL LOWS. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS EXPECTED IN EARLY MORNING FOG ON THURSDAY. SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES. WINDS WILL ONCE AGAIN BE LIGHT FROM THE SOUTHWEST/SOUTH LATE THIS EVENING. MODELS SHOW POTENTIAL FOR FOG DEVELOPMENT EARLY THURSDAY MORNING WITH LIGHT/CALM WIND...LOW LEVEL MOISTURE IN PLACE...AND DRY AIR ALOFT. WILL MENTION FOG AT AGS/DNL/OGB FROM 10Z THRU 14Z AND WILL CONTINUE TO UPDATE AS CONFIDENCE INCREASES. VSBYS AT AGS MAY DIP TO IFR LEVELS BEFORE 14Z THURSDAY. DAYTIME HEATING AND MIXING SHOULD ALLOW VFR CONDITIONS TO RETURN BY 14Z WITH MOSTLY SUNNY SKIES/PARTLY CLOUDY THROUGH THE END OF THE TAF PERIOD. SCATTERED CONVECTION POSSIBLE LATE THURSDAY AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO MENTION AT ANY OF THE TAF SITES AT THIS TIME. EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND SATURDAY MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
729 PM EDT WED APR 8 2015 .SYNOPSIS... CIRCULATION AROUND ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOIST SOUTHWESTERLY FLOW ACROSS OUR REGION INTO FRIDAY. A COLD FRONT WILL CROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. DAYTIME HEATING ALONG WITH UPPER-LEVEL ENERGY WILL PROVIDE A CHANCE OF MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES THROUGH TONIGHT. WATER VAPOR IMAGERY TRENDS INDICATE MUCH OF THE UPPER-LEVEL LIFT WILL STAY NORTH OF THE FORECAST AREA. THE LATEST LAPS SOUNDINGS INDICATE SHALLOW MOISTURE. MODERATE INSTABILITY LINGERING INTO THE EVENING SUPPORTS A SMALL POP MAINLY IN THE SOUTHEAST SECTION ASSOCIATED WITH THE SEA BREEZE FRONT AND WHERE THE HRRR HAS INDICATED DEVELOPMENT. USED THE GUIDANCE CONSENSUS FOR LOWS TONIGHT...MAINLY IN THE MIDDLE 60S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... UPPER RIDGE AXIS WILL SHIFT OVER THE FORECAST AREA ON THURSDAY AS SURFACE LOW PRESSURE DEEPENS AS IT LIFTS NORTHEASTWARD FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION. A MOIST SOUTHWESTERLY LOW LEVEL FLOW WILL CONTINUE ACROSS THE REGION BENEATH THE UPPER RIDGE ALLOWING FOR DIURNAL DESTABILIZATION OF THE AIR MASS AND WILL CONTINUE TO CARRY SLIGHT CHANCE TO LOW CHANCE POPS WITH LITTLE UPPER FORCING TO ORGANIZE CONVECTION. TEMPERATURES WILL AGAIN BE IN THE MID TO UPPER 80S ACROSS THE FORECAST AREA. SOME LINGERING CONVECTION POSSIBLE THURSDAY EVENING BUT EXPECT MOST OF THE CONVECTION TO COME TO AN END BY MIDNIGHT BUT WILL HOLD ON TO SLIGHT CHANCE POPS IN THE WESTERN MIDLANDS THROUGH THE NIGHT CLOSER TO THE DEEPER MOISTURE AND BETTER UPPER FORCING DESPITE A STABILIZING ATMOSPHERE. THE UPPER TROUGH AND ATTENDANT SURFACE LOW WILL LIFT INTO SOUTHEAST CANADA FRIDAY PUSHING A COLD FRONT ACROSS THE FORECAST AREA FRIDAY NIGHT. ABUNDANT MOISTURE WITH SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND INCREASED LOW LEVEL 850 MB FLOW AROUND 40 KNOTS WILL PROVIDE FAVORABLE CONDITIONS FOR CONVECTION FRIDAY AFTERNOON AND EVENING ACROSS THE REGION WITH A THREAT FOR SEVERE STORMS. SPC HAS OUTLOOKED THE AREA IN A SLIGHT RISK OF SEVERE STORMS FOR DAMAGING WINDS AND HAIL. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS AS THE FRONT PUSHES ACROSS THE AREA...ENHANCED BY UPPER JET STREAK PROVIDED LARGE SCALE LIFT IN ADDITION TO THE EXISTING INSTABILITY. WILL KEEP THE HIGH CHANCE TO LIKELY POPS GOING WITH DIMINISHING POPS FROM NORTHWEST TO SOUTHEAST LATE FRIDAY NIGHT. ONE LIMITING FACTOR COULD BE CLOUD COVER AHEAD OF THE FRONT. TEMPERATURES WILL BE WARM AGAIN ON FRIDAY WITH HIGHS IN THE LOWER TO MID 80S...MAYBE SOME UPPER 80S IN THE SOUTHEASTERN MIDLANDS. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... COOL SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY AND SATURDAY NIGHT BEHIND A COLD FRONT THAT WILL STALL OUT TO THE SOUTH OF THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT WITH DRIER CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH PRECIPITABLE WATER VALUES FALLING BELOW AN INCH WITH HIGH PRESSURE DOMINATING IN THE LOWER LEVELS. EARLY NEXT WEEK A BUILDING UPPER RIDGE...DOWNSTREAM OF A SPLIT FLOW CLOSED LOW EJECTING OUT OF THE DESERT SOUTHWEST...SHOULD HELP SUPPRESS DIURNAL CONVECTION BUT WILL CONTINUE WITH SLIGHT CHANCE POPS AS MOISTURE BEGINS TO INCREASE WITH A DEPARTING SURFACE HIGH. TEMPERATURES DURING THIS PERIOD WILL GENERALLY BE ABOVE NORMAL FOR HIGHS WITH THE COOLEST TEMPS OVER THE WEEKEND WITH A WARMING TREND NEXT WEEK...AND ABOVE NORMAL LOWS. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS FOR A MAJORITY OF THE TAF PERIOD. SOME RESTRICTIONS EXPECTED IN EARLY MORNING FOG ON THURSDAY. SURFACE HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO RIDGE INTO THE SOUTHEASTERN STATES. LOW POTENTIAL FOR SEVERE CONVECTION THIS EVENING. WINDS WILL ONCE AGAIN BE LIGHT FROM THE SOUTHWEST/SOUTH TONIGHT. MODELS SHOW POTENTIAL FOR FOG DEVELOPMENT EARLY THURSDAY MORNING WITH LIGHT/CALM WIND...LOW LEVEL MOISTURE IN PLACE...AND DRY AIR ALOFT. HAVE ADDED MENTION OF FOG AT AGS/DNL/OGB FROM 10Z THRU 14Z AND WILL CONTINUE TO UPDATE AS CONFIDENCE INCREASES. VSBYS AT AGS MAY DIP TO IFR LEVELS BEFORE 14Z THURSDAY. DAYTIME HEATING AND MIXING SHOULD ALLOW VFR CONDITIONS TO RETURN BY 14Z WITH MOSTLY SUNNY SKIES/PARTLY CLOUDY THROUGH THE END OF THE TAF PERIOD. SCATTERED CONVECTION POSSIBLE LATE THURSDAY AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO MENTION AT ANY OF THE TAF SITES AT THIS TIME. EXTENDED AVIATION OUTLOOK...POSSIBLE SHOWER AND/OR THUNDERSTORM ACTIVITY THURSDAY AFTERNOON AND EVENING. A FRONTAL BOUNDARY WILL BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT AND SATURDAY MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
351 AM EDT TUE APR 7 2015 .PREV DISCUSSION... /ISSUED 946 PM EDT MON APR 6 2015/ UPDATE... FIRST WAVE OF SHOWERS CURRENTLY MOVING INTO NE GA. A SECOND WAVE...ASSOCIATED WITH ANOTHER SHORTWAVE OVER WESTERN AL...IS EXPECTED TO MOVE THROUGH THE AREA THROUGH THE EARLY MORNING HOURS. NEWER RUNS OF THE HRRR HOLD THE SECOND AREA OF SHOWERS TOGETHER AS IT MOVES ACROSS GA. WILL GO AHEAD AND KEEP THE SLIGHT CHANCE OF THUNDER IN THE FORECAST...BUT INSTABILITY REMAINS WEAK. PREV DISCUSSION... /ISSUED 736 PM EDT MON APR 6 2015/ PREV DISCUSSION... /ISSUED 349 PM EDT MON APR 6 2015/ SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... A MOIST SOUTHERLY LOW LEVEL FLOW WILL CONTINUE OVER NORTH AND CENTRAL GA THROUGH THE FORECAST PERIOD ALONG WITH A NEAR ZONAL FLOW ALOFT. UPPER LEVEL DISTURBANCES OVER WEST TN AND SOUTH LA WILL MOVE EAST DURING THE NEXT 24 HOURS. THESE SYNOPTIC FEATURES WILL COMBINE WITH A WARM FRONT OVER THE GULF COAST GRADUALLY MOVING NORTH THROUGH THE STATE TONIGHT. CONSEQUENTLY...SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL LATE THIS AFTERNOON AND TONIGHT WITH RAINFALL AMOUNTS FROM 0.25 TO 0.50 INCH. DO NOT EXPECT ANY SEVERE TSTMS WITH THE MARGINAL INSTABILITY. ANOTHER SHORT WAVE WILL BE PASSING OVER THE TN VALLEY ON TUESDAY WITH THE BEST CHANCES OF TSTMS OVER EXTREME NORTH GA. HOWEVER... DIURNAL HEATING IN THE UPPER 70S AND 80S WITH A MOIST SOUTHWEST FLOW WILL TRIGGER SCATTERED TSTMS OVER THE REMAINDER OF NORTH AND ALL OF CENTRAL GA. THE SHOWERS AND TSTMS WILL GRADUALLY DIMINISH ON TUESDAY EVENING. THE WARM AND MOIST GULF FLOW WITH THE EXPECTED CLOUD COVER WILL HOLD MIN TEMPS TO AROUND 10 DEGREES ABOVE NORMAL TONIGHT AND TUESDAY NIGHT. MAX TEMPS ON TUESDAY WILL BE FROM 5 TO 10 DEGREES ABOVE NORMAL AS WELL. ACCEPTED AND MERGED MET/MAV MOS GUIDANCE FOR POPS AND TEMPS. 16 LONG TERM /WEDNESDAY THROUGH MONDAY/... NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. WEST TO SOUTHWEST UPPER FLOW CONTINUING OVER THE FORECAST AREA THROUGH THE PERIOD. SEVERAL WEAK IMPULSES CROSS THE STATE RESULTING IN A GENERALLY UNSETTLED PATTERN. HAVE CONTINUED WITH A CHANCE OR SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY MOST AREAS. THE MOST SIGNIFICANT SYSTEM SHOULD BE THE FRONT IN THE FRIDAY NIGHT THROUGH SATURDAY PERIOD. SOME LIKELY POPS SEEM REASONABLE ALONG THE FRONT FRIDAY. SOME DRYING INDICATED BEHIND THE FRONT FOR SATURDAY INTO SUNDAY. HOWEVER...WITH SOME TIMING DIFFERENCES POSSIBLE FOR THAT FAR OUT...HAVE LEFT IN A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS FOR THOSE TIMES. TEMPERATURES SHOULD BE WARM THROUGH THE WEEK...EXCEPT COOLING SOME FOR THE WEEKEND. 41/01 AVIATION... 18Z UPDATE... VFR CEILINGS GENERALLY PREVAILED OVER NORTH AND CENTRAL GA WITH SCATTERED SHOWERS AND TSTMS APPROACHING FROM THE WEST IN AL. EXPECT THE SHOWERS AND TSTMS TO INCREASE OVER THE TAF SITES THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING AS A WARM FRONT MOVES NORTH THROUGH THE STATE TONIGHT. CEILINGS WILL GRADUALLY LOWER TO IFR/MVFR AFTER MIDNIGHT THROUGH TUESDAY MORNING. SURFACE WINDS WILL BE SOUTHEAST BECOMING SOUTHWEST ON TUESDAY LESS THAN 10 KTS. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE FOR CEILINGS...VSBYS AND PRECIP TIMING. HIGH CONFIDENCE FOR WINDS. 16 && .AVIATION... 06Z UPDATE... IFR CIGS EXPECTED THROUGH MID MORNING...THEN IMPROVING CONDITIONS...WITH VFR BY LATE MORNING. SE WINDS AT 5KT OR LESS OVERNIGHT WILL INCREASE AND SHIFT TO THE SW BY MID MORNING. WINDS SHOULD HOVER JUST WEST OF SOUTH THROUGH THE DAY. PROB30 STILL INCLUDED FOR -TSRA FOR THE BEST AFTERNOON CHANCES...GENERALLY 17-23Z. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ON ALL ELEMENTS. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 79 60 84 63 / 30 20 30 20 ATLANTA 77 63 83 64 / 30 20 10 10 BLAIRSVILLE 73 56 79 59 / 50 20 40 20 CARTERSVILLE 78 59 84 62 / 30 20 20 10 COLUMBUS 83 64 86 64 / 20 10 10 10 GAINESVILLE 75 60 81 62 / 40 20 30 20 MACON 83 62 86 63 / 30 20 20 10 ROME 79 58 84 61 / 40 10 20 10 PEACHTREE CITY 80 58 83 62 / 20 10 10 10 VIDALIA 82 65 85 65 / 30 20 30 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...31 LONG TERM....41 AVIATION...31
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
955 PM CDT WED APR 8 2015 .UPDATE...945 PM... IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE ADVISORY IN PLACE. IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID- LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * MVFR/OCCL IFR VSBY WITH FOG TONIGHT. * IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR OVERNIGHT. * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING. * SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA MORE LIKELY THURS EARLY EVENING. KMD //DISCUSSION...UPDATED 00Z... IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT. ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN AGAIN THURSDAY AFTERNOON. WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT THREAT WITH THESE STORMS. AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER THUNDERSTORMS ARE POSSIBLE. KMD KMD //ORD AND MDW CONFIDENCE...UPDATED 03Z... * MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY WILL GET. * MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. * LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER CONFIDENCE LATE AFTERNOON AND EVENING. KMD //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM WEDNESDAY. DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
933 PM CDT WED APR 8 2015 .UPDATE...IN SPITE OF THE FACT THAT WEBCAMS INDICATE THE FOG HAS IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE ADVISORY IN PLACE. IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID- LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * MVFR/OCCL IFR VSBY WITH FOG TONIGHT. * IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR OVERNIGHT. * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING. * SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA MORE LIKELY THURS EARLY EVENING. KMD //DISCUSSION...UPDATED 00Z... IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT. ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN AGAIN THURSDAY AFTERNOON. WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT THREAT WITH THESE STORMS. AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER THUNDERSTORMS ARE POSSIBLE. KMD KMD //ORD AND MDW CONFIDENCE...UPDATED 00Z... * MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY WILL GET. * MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. * LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER CONFIDENCE LATE AFTERNOON AND EVENING. S KMD //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM WEDNESDAY. DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
759 PM CDT WED APR 8 2015 .UPDATE...547 PM CDT I ADDED A DENSE FOG ADVISORY FOR LAKE AND COOK COUNTIES IN ILLINOIS AS DENSE FOG HAS DEVELOPED NEAR THE LAKE SHORES. IT IS POSSIBLE THIS DENSE FOG COULD DEVELOP FARTHER INLAND THROUGH THE EVENING. IT IS EVEN POSSIBLE THAT FOG COULD OVERSPREAD MUCH OF NORTHERN ILLINOIS TONIGHT AS A WARM FRONT AND HIGH DEW POINT AIR BEGINS TO SLOWLY SHIFT NORTHWARD INTO THE COLDER AIRMASS ACROSS NORTHERN ILLINOIS. CONFIDENCE REMAINS LOW ON THE EXTENT OF INLAND DEVELOPMENT OF THIS FOG...HOWEVER...AS SHOWERS AND THUNDERSTORM ACTIVITY COULD DIMINISH THE EXTENT OF FOG COVERAGE OVERNIGHT. SO...WE WILL CONTINUE TO MONITOR THIS THREAT THROUGH THE EVENING. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * MVFR/OCCL IFR VSBY WITH FOG TONIGHT. * IFR/LIFR CIGS THIS EVENING...AND LIKELY A PERIOD OF LIFR OVERNIGHT. * SCATTERED THUNDERSTORMS DEVELOPING LATE THIS EVENING AND ESPECIALLY OVERNIGHT AND DIMINISHING EARLY TO MID THU MORNING. * SCATTERED THUNDERSTORMS THURS AFTERNOON...WITH A LINE OF TSRA MORE LIKELY THURS EARLY EVENING. KMD //DISCUSSION...UPDATED 00Z... IFR/LIFR CIGS AND LOWERED VISIBILITY ARE THE NEAR TERM CONCERNS...WHICH WILL CONTINUE TO BE A CONCERN OVERNIGHT. ADDITIONAL CONCERNS...AND MUCH LOWER CONFIDENCE...SURROUNDS CONVECTIVE EVOLUTION POTENTIAL THIS EVENING...OVERNIGHT...THEN AGAIN THURSDAY AFTERNOON. WITH A PERSISENT ENE WIND OFF THE LAKE...AND LITTLE CHANGE IN AIRMASS UNTIL THURSDAY MORNING...EXPECT IFR CIGS TO LOWER TO LIFR CLOSE TO THE LAKE...WITH MVFR CIGS INLAND LOWERING TO IFR OVER MUCH OF THE AREA OVERNIGHT. ATTENTION THEN SHIFTS TO COMPLEX OF THUNDERSTORMS NEARING THE MISSISSIPPI RIVER IN MISSOURI. VARIOUS HIGH RESOLUTION GUIDANCE WANTS TO BRING THIS COMPLEX INTO THE TERMINALS IN THE 5Z TIME FRAME AND MOVE ON THROUGH. WHILE THIS IS CERTAINLY A PLAUSIBLE SOLUTION...THE 0Z KILX SOUNDING IS RATHER DRY AND SHOULD TAKE SOME TIME TO SATURATE. FORECAST SOUNDINGS ALOFT BECOME UNSTABLE OVERNIGHT WITH ADDITIONAL SATURATION...THEREFORE CARRIED A VCTS FOR THE EARLIER TIME FRAME AS CONFIDENCE IN SATURATION BY THIS TIME IS LOW...THEN HELD ONTO TSRA OVERNIGHT AS THE LOWER LEVEL JET INTERACTS WITH THE WARM FRONT AND SUBTLE MID LEVEL SHORTWAVE TO BRING A BETTER CHANCE FOR SHOWERS AND SOME THUNDERSTORMS. HAIL WOULD BE THE MORE SIGNFICANT THREAT WITH THESE STORMS. AFTER THIS...CIGS SHOULD BEGIN TO LIFT AS THE WARM FRONT LIFTS NORTH. CONDITIONS BECOME QUITE UNSTABLE AGAIN THURSDAY AFTERNOON...AND WITH SOME HEIGHT FALLS THERE COULD BE SOME SCATTERED STRONG THUNDERSTORMS...BUT CARRIED VCTS FOR NOW AS A MORE ORGANIZED FORCING MECHANISH IS LACKING UNTIL LATE IN THE PERIOD WHEN THE SHARP UPPER TROUGH AND COLD FRONT MOVE THROUGH. IT IS THIS TIME FRAME THAT POSES THE BEST CHANCE FOR TSRA AND STRONG WINDS ACROSS THE TERMINALS. WENT PROB30 FOR NOW UNTIL TIMING CAN BE HONED IN ON...BUT THIS WILL BE A PERIOD WHERE STRONGER THUNDERSTORMS ARE POSSIBLE. KMD KMD //ORD AND MDW CONFIDENCE...UPDATED 00Z... * MEDIUM/HIGH CONFIDENCE IN CIGS/VSBY LOWERING THIS EVENING AFTER SUNSET AND ESPEICALLY OVERNIGHT. LOW CONFIDENCE IN HOW LOW THEY WILL GET. * MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE IN TS FROM LATE EVENING INTO THU MORNING...LOW TO MEDIUM FOR TIMING AND COVERAGE. * LOW CONFIDENCE IN TS TIMING IN COVERAGE THURS AFTERNOON...HIGHER CONFIDENCE LATE AFTERNOON AND EVENING. S KMD //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM WEDNESDAY. DENSE FOG ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 PM CDT TUE APR 7 2015 .UPDATE... 1129 AM CDT HAVE UPDATED GRIDS/TEXT PRODUCTS ALREADY TO LOWER TEMPERATURES TODAY...ESPECIALLY NEAR THE LAKE WHERE STIFF WIND OFF THE LAKE SHOULD MAKE IT HARD FOR TEMPS TO EVEN REACH 40 THIS AFTERNOON. WEBCAMS ALONG THE LAKE AND LAURIE CHILDREN`S HOSP HELIPORT AWOS INDICATE THAT DENSE MARINE FOG IS MAKING IT SLIGHTLY ONSHORE. CERTAINLY POSSIBLE THAT FOG COULD GROW DENSER ALONG THE LAKE LATER TODAY OR TONIGHT AND POTENTIALLY REQUIRE A HEADLINE. HAVE BACKED OFF ON POPS SIGNIFICANTLY TODAY ONE MCV PASSES WELL TO OUR SOUTH AND WE ARE LEFT WAITING FOR THE NEXT UPSTREAM IMPULSE TO KICK OFF CONVECTION WHICH LOOKS TO BE TONIGHT...OR POSSIBLE VERY LATE THIS AFTERNOON WESTERN CWA. IZZI && .SHORT TERM... 408 AM CDT TODAY THROUGH THURSDAY NIGHT... THE MAIN FOCUS IN THE NEAR TERM REMAINS ON IDENTIFYING THE BEST TIMING FOR ROUNDS OF SHOWERS AND THUNDERSTORMS AS INDIVIDUAL SHORT WAVES PROPAGATE ALONG WEST-EAST BAROCLINC ZONE ASSOCIATED WITH A NEARLY STATIONARY SURFACE FRONT ACROSS CENTRAL ILLINOIS AND INDIANA. IN ADDITION...SUBSTANTIAL CONCERN IS BREWING FOR THE POTENTIAL OF ORGANIZED SEVERE WEATHER ON THURSDAY...WITH ENERGETIC UPPER TROUGH AND DEEP SURFACE LOW EXPECTED TO MOVE INTO THE AREA. THIS MORNING...THE NEARLY STATIONARY SURFACE FRONT HAS DRIFTED A BIT TO THE SOUTH IN THE WAKE OF A MINOR-AMPLITUDE MID-LEVEL SHORT WAVE AND WEAK SURFACE WAVE ALONG THE FRONT WHICH WAS MOVING INTO INDIANA. A CLUSTER OF SHOWERS AND A FEW THUNDERSTORMS HAVE ALSO MOVED OFF TO THE EAST EARLY THIS MORNING WITH THE AXIS OF BETTER LOW LEVEL MOISTURE TRANSPORT AND THE VEERING OF A MODEST 30 KT LOW LEVEL JET ASSOCIATED WITH THE PASSING SHORT WAVE. WHILE SOME LIGHT DRIZZLE OR SPOTTY LIGHT SHOWERS WILL REMAIN POSSIBLE WITH WEAK BUT PERSISTENT WARM/MOIST ADVECTION WITHING THE FRONTAL ZONE...IT APPEARS THERE WILL BE A LULL IN MORE ORGANIZED PRECIPITATION UNTIL ANOTHER SHORT WAVE ARRIVES. LOOKING UPSTREAM IN WATER VAPOR IMAGERY THIS MORNING ONE SUCH WAVE WAS EVIDENT OVER EASTERN KANSAS...WITH ELEVATED CONVECTION NOTED JUST EAST OF KANSAS CITY. YET ANOTHER IDENTIFIABLE WAVE WAS CROSSING THE CENTRAL ROCKIES. PRECIP POTENTIAL THUS LOOKS TO INCREASE AGAIN FROM THE WEST/SOUTHWEST THIS AFTERNOON INTO TONIGHT AS THESE WAVES APPROACH. MODELS HAVE CONSISTENTLY DEPICTED THE DEEPER COLORADO SHORT WAVE TRACKING TOWARD THE REGION TONIGHT INTO EARLY WEDNESDAY...ENHANCING WARM/MOIST ADVECTION INTO THE FORECAST AREA TONIGHT. STRONGER MOISTURE TRANSPORT LOOKS TO FOCUS INTO THE AREA BY EARLY EVENING WITH GOOD SUPPORT FOR SHOWERS AND THUNDERSTORMS...NOTABLY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM AND A POSITION BENEATH RIGHT ENTRANCE DIVERGENCE REGION OF UPPER JET STREAK NORTHEAST OF THE LAKES. HAVE CARRIED LIKELY POPS AND MENTION OF THUNDER CWA-WIDE TONIGHT...BEFORE PRECIP COVERAGE IS EXPECTED TO AGAIN DECREASE AFTER SUNRISE WEDNESDAY MORNING AS THE WAVE TRACKS TO THE EAST AND LOW LEVEL JET VEERS/WEAKENS. ATTENTION THEN TURNS TO THE UPPER TROUGH WHICH HAS BEEN JUST OFF OF THE WEST COAST...AND IS PROGGED TO MOVE INLAND ACROSS THE INTERMOUNTAIN WEST AND THE ROCKIES THROUGH WEDNESDAY. GUIDANCE HAS REMAINED SIMILAR IN WRAPPING JET ENERGY AROUND THE BASE OF THIS DEEP UPPER LOW AND EJECTING SHORT WAVE ACROSS THE MID-MISSISSIPPI VALLEY LATE WEDNESDAY AND WEDNESDAY NIGHT...WITH THE MAIN UPPER TROUGH THEN LIFTING NORTHEAST AND BECOMING A SOMEWHAT COMPACT/NEGATIVE TILT SYSTEM AS IT APPROACHES OUR AREA ON THURSDAY. THIS SETS THE STAGE FOR STRONG THERMAL/MOISTURE ADVECTION DEVELOPING ACROSS THE MIDWEST LATE WEDNESDAY AND WEDNESDAY NIGHT...AND THE SURFACE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE AREA THROUGH THURSDAY AS THE DEEP SURFACE LOW WITH THE MAIN UPPER TROUGH MOVES INTO THE UPPER MIDWEST. THIS LOOKS TO PRODUCE A FAIRLY WIDESPREAD AREA OF CONVECTION WHICH WILL IMPACT THE CWA WEDNESDAY NIGHT INTO EARLY THURSDAY. AS THE WARM FRONT LIFTS NORTH INTO/ACROSS THE CWA THURSDAY AFTERNOON...THE MOISTURE RICH WARM SECTOR HAS THE POTENTIAL TO BECOME STRONGLY UNSTABLE. FORECAST SOUNDINGS FROM THE GFS AND NAM BOTH DEPICT MLCAPES IN THE 1500-2500 J/KG RANGE IN THE WARM SECTOR ACROSS OUR AREA BY THURSDAY AFTERNOON...COINCIDENT WITH 40-50 KT 0-6 KM BULK SHEAR AND STRONG ASCENT AHEAD OF APPROACHING DEEP UPPER TROUGH. MANY MODEL RUNS TAKE THE SYSTEM SURFACE LOW ACROSS NORTHEAST IA/SOUTHWEST WI BY THURSDAY EVENING..WITH A COLD FRONT PUSHING ACROSS THE MISSISSIPPI RIVER AND ACROSS NORTHERN IL/IN THURSDAY EVENING. THIS LOOKS TO PRESENT A SUBSTANTIAL SEVERE WEATHER THREAT ESPECIALLY IN THE THURSDAY AFTERNOON/EARLY EVENING PERIOD...WITH MORE THAN SUFFICIENT SHEAR/INSTABILITY FOR SUPERCELL STORMS WHICH MAY THEN EVOLVE INTO A SEVERE LINEAR MCS. DETAILS OF MORNING CONVECTIVE DEBRIS AND CLOUDINESS AND POSITION OF THE EFFECTIVE SURFACE WARM FRONTAL BOUNDARY WILL ALL ULTIMATELY AFFECT HOW AFTERNOON STORMS EVOLVE. SPC HAS MAINTAINED A 30 PERCENT ENHANCED SEVERE RISK AREA OVER OUR ENTIRE CWA FOR THIS PERIOD. SEVERE THREAT AS WELL AS GENERAL SHOWER/THUNDERSTORM THREAT SHOULD DIMINISH QUICKLY BEHIND THE COLD FRONT THURSDAY NIGHT. TEMPS WILL CONTINUE TO SHOW BIG NORTH-SOUTH RANGE WITH EAST- NORTHEAST FLOW OFF COOL LAKE KEEPING NORTHERN COUNTIES AND ESPECIALLY LAKE SHORE AREAS CHILLY THROUGH WEDNESDAY NIGHT. FARTHER SOUTH...CLOSER TO THE SURFACE FRONT TEMPS WILL LIKELY BE ABLE TO REACH THE MID-UPPER 60S ESPECIALLY IF A LITTLE SUN BREAKS THROUGH. ON THURSDAY...70S ARE LIKELY ALONG/SOUTH OF THE NORTHWARD ADVANCING WARM FRONT. RATZER && .LONG TERM... 422 AM CDT FRIDAY THROUGH MONDAY... WITH THE COLD FRONT EAST OF THE FORECAST AREA BY EARLY FRIDAY...AND THE UPPER TROUGH AND SURFACE LOW PASSING NORTH OF THE IL/WI BORDER FOR THE MOST PART...DRIER AIR MOVES IN FOR FRIDAY AND SATURDAY AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. MEDIUM RANGE GUIDANCE SHOWING SOME DIFFERENCE IN DETAILS WITH PATTERN OVER THE WEEKEND AND INTO EARLY NEXT WEEK BUT GENERALLY DEVELOP UPPER RIDGE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY...DOWNSTREAM OF AN AMPLIFIED UPPER TROUGH OVER THE WESTERN CONUS. THIS SETS UP A RETURN OF SOUTH FLOW AND WARM/MOIST ADVECTION LATER SUNDAY AND MONDAY...WITH THE POTENTIAL FOR SHOWERS AND STORMS TO RETURN AS THE UPPER TROUGH APPROACHES. AFTER A SLIGHT COOL-DOWN FRIDAY INTO SATURDAY (THOUGH NEAR NORMAL AND WARMER THAN OUR CURRENT CHILLY TEMPS)...WARMER WEATHER RETURNS SUNDAY-MONDAY WITH HIGHS IN THE MID-UPPER 60S. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * PERSISTENT IFR CIGS/VSBYS THIS AFTERNOON WITH LIFR POSSIBLE. * NORTHEAST WINDS GUSTING AT TIMES OVER 20 KTS. * TSRA CHANCES OVERNIGHT. * CONTINUED IFR TOMORROW. LENNING //DISCUSSION...UPDATED 18Z... CONDITIONS CONTINUE TO DETERIORATE GRADUALLY THIS AFTERNOON RAISING THE QUESTION OF HOW LOW CIGS AND VSBYS WILL DROP. CIGS RANGED FROM 300-600FT IN THE CHI METRO AREA AS OF THE 18Z TAF TIME WITH THE LOWEST VALUES JUST SOUTH OF THE MDW TERMINAL. MEANWHILE TO THE NORTH TOWARD MKX CONDITIONS WERE STAYING IN THE MVFR TO VFR RANGE. BETTER SFC AND LOW LEVEL MOISTURE OVER NE IL WOULD APPEAR TO BE SUPPORTING THE LOWER CONDITIONS IN THIS AREA. MODELS SUGGEST PERSISTENCE OR EVEN EXPANSION OF THIS MOISTURE THROUGH THE DAY INTO THE EVENING HOURS. A BREAK MAY COME WITH THE DEVELOPMENT OF SHOWERS AND POSSIBLE THUNDERSTORMS TOWARD LATE EVENING THOUGH THIS WOULD BE AFTER THE PEAK TRAFFIC PERIOD. TOMORROW SHOWS LITTLE CHANGE AFTER PRECIPITATION MOVES OUT DURING THE PREDAWN HOURS. IN FACT...WITH THE PERSISTENT AIRMASS AND INCREASED SURFACE MOISTURE INTRODUCED BY OVERNIGHT RAINFALL...THE POTENTIAL EXISTS FOR LOWER CONDITIONS TOMORROW...AT LEAST THROUGH THE MORNING. LENNING //ORD AND MDW CONFIDENCE...UPDATED 20Z... * LOW TO MEDIUM CONFIDENCE IN CIG/VSBY TRENDS...STILL UNSURE OF WHETHER THEY GO TO LIFR THIS AFTERNOON AND EVENING. * MEDIUM TO HIGH CONFIDENCE IN WINDS REMAINING MAINLY NORTHEAST. * MEDIUM CONFIDENCE IN SHRA AND TSRA TIMING TONIGHT. LENNING //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...SHRA/TSRA. IFR. EAST/SOUTHEAST WINDS. * THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST WINDS. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. SOUTHEAST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. && .MARINE... 348 AM...A FRONTAL BOUNDARY WILL REMAIN GENERALLY STATIONARY THROUGH WEDNESDAY JUST SOUTH OF LAKE MICHIGAN...AS STRONG HIGH PRESSURE MOVES ACROSS ONTARIO TODAY AND INTO QUEBEC TONIGHT. THIS WILL TIGHTEN THE GRADIENT LATER TODAY INTO TONIGHT WITH A PERIOD OF 30KTS EXPECTED. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS WEDNESDAY NIGHT AND MOVE NORTHEAST TOWARD NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. THE EXACT TRACK OF THIS LOW REMAINS SOMEWHAT UNCERTAIN...BUT THESE TRENDS WOULD SUPPORT THE FRONTAL BOUNDARY MOVING NORTH AS A WARM FRONT WEDNESDAY NIGHT INTO THURSDAY. THUS THERE IT THE POTENTIAL FOR LARGE CHANGES TO WIND DIRECTIONS OVER PARTS OF THE LAKE FROM WEDNESDAY NIGHT INTO THURSDAY NIGHT. EVENTUALLY WINDS WILL SHIFT WESTERLY LATE THURSDAY NIGHT INTO FRIDAY MORNING...THEN BEGIN TO DIMINISH FRIDAY NIGHT AS HIGH PRESSURE MOVES ACROSS THE LAKE ON SATURDAY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1255 PM CDT Tue Apr 7 2015 .UPDATE... ISSUED AT 1040 AM CDT TUE APR 7 2015 Will update the forecast around 11 am when dense fog advisory over central IL expires. Some patchy fog may linger into midday over areas north of I-70 but most of the dense fog over central IL should lift late this morning. A frontal boundary has sagged southward into central IL near I-72 late this morning and HRRR models keeps this boundary near I-72 into early evening. 1007 mb surface low pressure over ne KS will track into nw MO early this evening and tug front slowly back north during tonight. Have cooled highs north of this boundary with upper 50s and lower 60s for highs from Galesburg, Peoria and Bloomington north where low clouds persist. Showers south of I-72 with thunderstorms from Litchfied sw and some strong to severe with heavy rains from St Louis south. Severe storms should stay along and south of I-64 today though a few thunderstorms could affect areas from I-72 south this afternoon along and south of the boundary. Milder highs in low to mid 70s in sw CWA from Springfield to Terre Haute sw where some peaks of sunshine to appear during the afternoon. && .SHORT TERM...(Today) ISSUED AT 335 AM CDT TUE APR 7 2015 A few showers and isolated thunderstorms will continue to move across southeast Illinois early this morning. HiRes short term models develop another area of showers and isolated thunderstorms over northern MO and then bring them into central IL late morning and into the afternoon. The warm front has setup and is sitting right through central IL, north of a Quincy to Springfield to Mattoon line, which puts half of the cwa south of the front, and the I-74 area, including Lincoln, north of the front. So, area of convection that does develop should follow along and just north of the front when it arrives later this morning. So, have likely pops in the southeast for this morning, and then slightly higher pops in the afternoon for the west central. With front right across CWA high temp spread with be around 15 degrees across the CWA today. Cloud cover will also be persistent today, with some light fog this morning. With pcpn being mainly scattered, qpf values will not be that significant. && .LONG TERM...(Tonight through Monday) ISSUED AT 335 AM CDT TUE APR 7 2015 The warm front should become a little more active this evening and shift north, as the first in a series of low pressure areas moves along the frontal zone. So, higher pcpn chances will be in the north for tonight with chance pops remaining for the rest of the area, which will be in the warm sector. Lowest pops will be in the south. As this first low moves east, it will drag the cold front south through the cwa, so pops for Wed morning will be higher to the south and only a slight chance in the north. However, the next wave/low press area will lift out Wed afternoon and return chance pops for the whole area. This one will lift northeast through the area and bring much higher chances of pcpn to the CWA for late Wed afternoon through Wed night. Per SPC day 2 outlook, there is a slight risk of severe weather nosing into west central IL for late Wed afternoon and into Wed night. Highest pops will be west of I-55. Probably will be a little break Wed night after midnight, but will not put that in just yet. Then on Thursday, the main sfc system will lift out of the plains with the associated mid level wave. Though there may be pcpn ongoing Thur morning in the east, by afternoon most of the area should be pcpn free and the atmosphere should be able to recover before the next round of pcpn. Forecasted CAPE values will be 2000 to 2500 across a good portion of IL in the warm sector ahead of the front. A strong upper level jet will also be pushing into the area at the same time, so wind dynamics and shear will be sufficient that storms will likely rotate. There is still some uncertainty as to how this will play out Thur given the Wed night and early morning convection, but if airmass recovers, it looks like a line of convection will develop just west of the state late afternoon and then move east across the state Thur evening. All forms of severe weather look to be possible late afternoon through the evening hours. Something to consider is that storms may be moving at about 40-45 mph. By midnight, most of the storms should be east of the state, but will hang on to some chance pops. Past this system, dry conditions are expected for Fri through Sat night. Then another system moves toward the area for Sunday through Monday with more showers and storms. Expecting very warm temps for Thur, but then temps will cool some Fri and Sat, but warm back a tad for Sun and Mon. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1255 PM CDT TUE APR 7 2015 Dense fog lingering at BMI...CMI and DEC airports will gradually lift into mid afternoon with MVFR to possibly vfr vsbys. Vsbys at PIA and SPI have lifted to 1-2 miles and to lift to MVFR and VFR next few hours. Very low ceilings of 100-300 ft to lift to 700-1500 feet during mid/late afternoon across central IL. I-72 is on northern edge of showers and isolated thunderstorms and will carry vcsh at SPI and DEC into mid afternoon with VCTS at CMI. Scattered showers/thunderstorms possible by overnight into mid morning Wed as frontal boundary just south of I-72 lifts slowly back north as 1007 mb surface low pressure over ne KS moves into central IL by 12Z/Wed. ENE winds around 10 kts to veer SSE during tonight and SW Wed morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...Auten LONG TERM...Auten AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT TUE APR 7 2015 .SHORT TERM... 408 AM CDT TODAY THROUGH THURSDAY NIGHT... THE MAIN FOCUS IN THE NEAR TERM REMAINS ON IDENTIFYING THE BEST TIMING FOR ROUNDS OF SHOWERS AND THUNDERSTORMS AS INDIVIDUAL SHORT WAVES PROPAGATE ALONG WEST-EAST BAROCLINC ZONE ASSOCIATED WITH A NEARLY STATIONARY SURFACE FRONT ACROSS CENTRAL ILLINOIS AND INDIANA. IN ADDITION...SUBSTANTIAL CONCERN IS BREWING FOR THE POTENTIAL OF ORGANIZED SEVERE WEATHER ON THURSDAY...WITH ENERGETIC UPPER TROUGH AND DEEP SURFACE LOW EXPECTED TO MOVE INTO THE AREA. THIS MORNING...THE NEARLY STATIONARY SURFACE FRONT HAS DRIFTED A BIT TO THE SOUTH IN THE WAKE OF A MINOR-AMPLITUDE MID-LEVEL SHORT WAVE AND WEAK SURFACE WAVE ALONG THE FRONT WHICH WAS MOVING INTO INDIANA. A CLUSTER OF SHOWERS AND A FEW THUNDERSTORMS HAVE ALSO MOVED OFF TO THE EAST EARLY THIS MORNING WITH THE AXIS OF BETTER LOW LEVEL MOISTURE TRANSPORT AND THE VEERING OF A MODEST 30 KT LOW LEVEL JET ASSOCIATED WITH THE PASSING SHORT WAVE. WHILE SOME LIGHT DRIZZLE OR SPOTTY LIGHT SHOWERS WILL REMAIN POSSIBLE WITH WEAK BUT PERSISTENT WARM/MOIST ADVECTION WITHING THE FRONTAL ZONE...IT APPEARS THERE WILL BE A LULL IN MORE ORGANIZED PRECIPITATION UNTIL ANOTHER SHORT WAVE ARRIVES. LOOKING UPSTREAM IN WATER VAPOR IMAGERY THIS MORNING ONE SUCH WAVE WAS EVIDENT OVER EASTERN KANSAS...WITH ELEVATED CONVECTION NOTED JUST EAST OF KANSAS CITY. YET ANOTHER IDENTIFIABLE WAVE WAS CROSSING THE CENTRAL ROCKIES. PRECIP POTENTIAL THUS LOOKS TO INCREASE AGAIN FROM THE WEST/SOUTHWEST THIS AFTERNOON INTO TONIGHT AS THESE WAVES APPROACH. MODELS HAVE CONSISTENTLY DEPICTED THE DEEPER COLORADO SHORT WAVE TRACKING TOWARD THE REGION TONIGHT INTO EARLY WEDNESDAY...ENHANCING WARM/MOIST ADVECTION INTO THE FORECAST AREA TONIGHT. STRONGER MOISTURE TRANSPORT LOOKS TO FOCUS INTO THE AREA BY EARLY EVENING WITH GOOD SUPPORT FOR SHOWERS AND THUNDERSTORMS...NOTABLY STEEP MID-LEVEL LAPSE RATES IN EXCESS OF 7.5 C/KM AND A POSITION BENEATH RIGHT ENTRANCE DIVERGENCE REGION OF UPPER JET STREAK NORTHEAST OF THE LAKES. HAVE CARRIED LIKELY POPS AND MENTION OF THUNDER CWA-WIDE TONIGHT...BEFORE PRECIP COVERAGE IS EXPECTED TO AGAIN DECREASE AFTER SUNRISE WEDNESDAY MORNING AS THE WAVE TRACKS TO THE EAST AND LOW LEVEL JET VEERS/WEAKENS. ATTENTION THEN TURNS TO THE UPPER TROUGH WHICH HAS BEEN JUST OFF OF THE WEST COAST...AND IS PROGGED TO MOVE INLAND ACROSS THE INTERMOUNTAIN WEST AND THE ROCKIES THROUGH WEDNESDAY. GUIDANCE HAS REMAINED SIMILAR IN WRAPPING JET ENERGY AROUND THE BASE OF THIS DEEP UPPER LOW AND EJECTING SHORT WAVE ACROSS THE MID-MISSISSIPPI VALLEY LATE WEDNESDAY AND WEDNESDAY NIGHT...WITH THE MAIN UPPER TROUGH THEN LIFTING NORTHEAST AND BECOMING A SOMEWHAT COMPACT/NEGATIVE TILT SYSTEM AS IT APPROACHES OUR AREA ON THURSDAY. THIS SETS THE STAGE FOR STRONG THERMAL/MOISTURE ADVECTION DEVELOPING ACROSS THE MIDWEST LATE WEDNESDAY AND WEDNESDAY NIGHT...AND THE SURFACE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE AREA THROUGH THURSDAY AS THE DEEP SURFACE LOW WITH THE MAIN UPPER TROUGH MOVES INTO THE UPPER MIDWEST. THIS LOOKS TO PRODUCE A FAIRLY WIDESPREAD AREA OF CONVECTION WHICH WILL IMPACT THE CWA WEDNESDAY NIGHT INTO EARLY THURSDAY. AS THE WARM FRONT LIFTS NORTH INTO/ACROSS THE CWA THURSDAY AFTERNOON...THE MOISTURE RICH WARM SECTOR HAS THE POTENTIAL TO BECOME STRONGLY UNSTABLE. FORECAST SOUNDINGS FROM THE GFS AND NAM BOTH DEPICT MLCAPES IN THE 1500-2500 J/KG RANGE IN THE WARM SECTOR ACROSS OUR AREA BY THURSDAY AFTERNOON...COINCIDENT WITH 40-50 KT 0-6 KM BULK SHEAR AND STRONG ASCENT AHEAD OF APPROACHING DEEP UPPER TROUGH. MANY MODEL RUNS TAKE THE SYSTEM SURFACE LOW ACROSS NORTHEAST IA/SOUTHWEST WI BY THURSDAY EVENING..WITH A COLD FRONT PUSHING ACROSS THE MISSISSIPPI RIVER AND ACROSS NORTHERN IL/IN THURSDAY EVENING. THIS LOOKS TO PRESENT A SUBSTANTIAL SEVERE WEATHER THREAT ESPECIALLY IN THE THURSDAY AFTERNOON/EARLY EVENING PERIOD...WITH MORE THAN SUFFICIENT SHEAR/INSTABILITY FOR SUPERCELL STORMS WHICH MAY THEN EVOLVE INTO A SEVERE LINEAR MCS. DETAILS OF MORNING CONVECTIVE DEBRIS AND CLOUDINESS AND POSITION OF THE EFFECTIVE SURFACE WARM FRONTAL BOUNDARY WILL ALL ULTIMATELY AFFECT HOW AFTERNOON STORMS EVOLVE. SPC HAS MAINTAINED A 30 PERCENT ENHANCED SEVERE RISK AREA OVER OUR ENTIRE CWA FOR THIS PERIOD. SEVERE THREAT AS WELL AS GENERAL SHOWER/THUNDERSTORM THREAT SHOULD DIMINISH QUICKLY BEHIND THE COLD FRONT THURSDAY NIGHT. TEMPS WILL CONTINUE TO SHOW BIG NORTH-SOUTH RANGE WITH EAST- NORTHEAST FLOW OFF COOL LAKE KEEPING NORTHERN COUNTIES AND ESPECIALLY LAKE SHORE AREAS CHILLY THROUGH WEDNESDAY NIGHT. FARTHER SOUTH...CLOSER TO THE SURFACE FRONT TEMPS WILL LIKELY BE ABLE TO REACH THE MID-UPPER 60S ESPECIALLY IF A LITTLE SUN BREAKS THROUGH. ON THURSDAY...70S ARE LIKELY ALONG/SOUTH OF THE NORTHWARD ADVANCING WARM FRONT. RATZER && .LONG TERM... 422 AM CDT FRIDAY THROUGH MONDAY... WITH THE COLD FRONT EAST OF THE FORECAST AREA BY EARLY FRIDAY...AND THE UPPER TROUGH AND SURFACE LOW PASSING NORTH OF THE IL/WI BORDER FOR THE MOST PART...DRIER AIR MOVES IN FOR FRIDAY AND SATURDAY AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. MEDIUM RANGE GUIDANCE SHOWING SOME DIFFERENCE IN DETAILS WITH PATTERN OVER THE WEEKEND AND INTO EARLY NEXT WEEK BUT GENERALLY DEVELOP UPPER RIDGE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY...DOWNSTREAM OF AN AMPLIFIED UPPER TROUGH OVER THE WESTERN CONUS. THIS SETS UP A RETURN OF SOUTH FLOW AND WARM/MOIST ADVECTION LATER SUNDAY AND MONDAY...WITH THE POTENTIAL FOR SHOWERS AND STORMS TO RETURN AS THE UPPER TROUGH APPROACHES. AFTER A SLIGHT COOL-DOWN FRIDAY INTO SATURDAY (THOUGH NEAR NORMAL AND WARMER THAN OUR CURRENT CHILLY TEMPS)...WARMER WEATHER RETURNS SUNDAY-MONDAY WITH HIGHS IN THE MID-UPPER 60S. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * IFR TO MVFR CEILINGS AND VSBYS TODAY...LIFR POSSIBLE TONIGHT. * NORTHEAST WINDS. * THUNDERSTORM CHANCES TONIGHT. LENNING //DISCUSSION...UPDATED 12Z... LIGHT SHOWERS/DRIZZLE HAVE REDEVELOPED AND BECOME QUITE WIDESPREAD THIS MORNING. SHORT TERM/HI RES GUIDANCE SUGGESTS THIS WILL SLOWLY DISSIPATE DURING THE MID/LATE MORNING SO HAVE ADDED PRECIP IN FOR A FEW HOURS TRENDING BACK TO VCSH DUE TO LOWER UNCERTAINTY. THIS AFTERNOON IS STILL LOOKING MAINLY DRY AS CONVECTION CURRENTLY ACROSS NORTHEAST MO SHIFTS MORE EAST AND ALSO APPEARS TO DISSIPATE SOME LATER THIS MORNING. FOCUS THEN SHIFTS BACK TO THE WEST/ NORTHWEST LATE THIS AFTERNOON INTO THIS EVENING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER NORTHEAST IA AND MOVE EAST/SOUTHEAST LATER THIS EVENING AND OVERNIGHT. FAIRLY CONFIDENT CONVECTION WILL DEVELOP BUT LOWER CONFIDENCE REGARDING MOVEMENT/LOCATION/TIMING. OPTED TO INCLUDE A TEMPO FOR THUNDER LATE THIS EVENING/OVERNIGHT BUT REFINEMENT CAN BE EXPECTED WITH LATER FORECASTS. CIGS HAVE BEEN SLOW TO LOWER ACROSS ORD/MDW/DPA WITH MDW JUST NOW INTO IFR. SLIGHTLY DRIER NORTHEAST FLOW COMBINED WITH A LACK OF SIGNIFICANT PRECIP MAY ALLOW CIGS TO STAY ABOVE IFR TODAY BUT HAVE MAINTAINED IFR CIGS IN THE FORECAST WITH LOW CONFIDENCE. CIGS WILL LIKELY LOWER EITHER TO IFR OR POTENTIALLY LIFR LATER THIS EVENING OR OVERNIGHT...ESPECIALLY IF PRECIP DOES BECOME WIDESPREAD LATER THIS EVENING AND OVERNIGHT. NORTHEAST WINDS WILL REMAIN IN THE 12-16KT RANGE FOR MUCH OF THE PERIOD WITH GUSTS INTO THE LOWER/MID 20KT RANGE AT TIMES. WINDS MAY TURN A BIT MORE EASTERLY TONIGHT WITH SPEEDS/GUSTS DIMINISHING SOME INTO WEDNESDAY MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM CONFIDENCE IN CEILING AND VSBY TRENDS. * MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS. LENNING //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...SHRA/TSRA. IFR. EAST/SOUTHEAST WINDS. * THURSDAY...STRONG TSRA. MVFR. STRONG/GUSTY SOUTH/SOUTHWEST WINDS. * FRIDAY...DRY/VFR. STRONG/GUSTY WEST WINDS. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. SOUTHEAST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. && .MARINE... 348 AM...A FRONTAL BOUNDARY WILL REMAIN GENERALLY STATIONARY THROUGH WEDNESDAY JUST SOUTH OF LAKE MICHIGAN...AS STRONG HIGH PRESSURE MOVES ACROSS ONTARIO TODAY AND INTO QUEBEC TONIGHT. THIS WILL TIGHTEN THE GRADIENT LATER TODAY INTO TONIGHT WITH A PERIOD OF 30KTS EXPECTED. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS WEDNESDAY NIGHT AND MOVE NORTHEAST TOWARD NORTHERN LAKE MICHIGAN BY FRIDAY MORNING. THE EXACT TRACK OF THIS LOW REMAINS SOMEWHAT UNCERTAIN...BUT THESE TRENDS WOULD SUPPORT THE FRONTAL BOUNDARY MOVING NORTH AS A WARM FRONT WEDNESDAY NIGHT INTO THURSDAY. THUS THERE IT THE POTENTIAL FOR LARGE CHANGES TO WIND DIRECTIONS OVER PARTS OF THE LAKE FROM WEDNESDAY NIGHT INTO THURSDAY NIGHT. EVENTUALLY WINDS WILL SHIFT WESTERLY LATE THURSDAY NIGHT INTO FRIDAY MORNING...THEN BEGIN TO DIMINISH FRIDAY NIGHT AS HIGH PRESSURE MOVES ACROSS THE LAKE ON SATURDAY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1043 AM CDT Tue Apr 7 2015 .UPDATE... ISSUED AT 1040 AM CDT TUE APR 7 2015 Will update the forecast around 11 am when dense fog advisory over central IL expires. Some patchy fog may linger into midday over areas north of I-70 but most of the dense fog over central IL should lift late this morning. A frontal boundary has sagged southward into central IL near I-72 late this morning and HRRR models keeps this boundary near I-72 into early evening. 1007 mb surface low pressure over ne KS will track into nw MO early this evening and tug front slowly back north during tonight. Have cooled highs north of this boundary with upper 50s and lower 60s for highs from Galesburg, Peoria and Bloomington north where low clouds persist. Showers south of I-72 with thunderstorms from Litchfied sw and some strong to severe with heavy rains from St Louis south. Severe storms should stay along and south of I-64 today though a few thunderstorms could affect areas from I-72 south this afternoon along and south of the boundary. Milder highs in low to mid 70s in sw CWA from Springfield to Terre Haute sw where some peaks of sunshine to appear during the afternoon. && .SHORT TERM...(Today) ISSUED AT 335 AM CDT TUE APR 7 2015 A few showers and isolated thunderstorms will continue to move across southeast Illinois early this morning. HiRes short term models develop another area of showers and isolated thunderstorms over northern MO and then bring them into central IL late morning and into the afternoon. The warm front has setup and is sitting right through central IL, north of a Quincy to Springfield to Mattoon line, which puts half of the cwa south of the front, and the I-74 area, including Lincoln, north of the front. So, area of convection that does develop should follow along and just north of the front when it arrives later this morning. So, have likely pops in the southeast for this morning, and then slightly higher pops in the afternoon for the west central. With front right across CWA high temp spread with be around 15 degrees across the CWA today. Cloud cover will also be persistent today, with some light fog this morning. With pcpn being mainly scattered, qpf values will not be that significant. && .LONG TERM...(Tonight through Monday) ISSUED AT 335 AM CDT TUE APR 7 2015 The warm front should become a little more active this evening and shift north, as the first in a series of low pressure areas moves along the frontal zone. So, higher pcpn chances will be in the north for tonight with chance pops remaining for the rest of the area, which will be in the warm sector. Lowest pops will be in the south. As this first low moves east, it will drag the cold front south through the cwa, so pops for Wed morning will be higher to the south and only a slight chance in the north. However, the next wave/low press area will lift out Wed afternoon and return chance pops for the whole area. This one will lift northeast through the area and bring much higher chances of pcpn to the CWA for late Wed afternoon through Wed night. Per SPC day 2 outlook, there is a slight risk of severe weather nosing into west central IL for late Wed afternoon and into Wed night. Highest pops will be west of I-55. Probably will be a little break Wed night after midnight, but will not put that in just yet. Then on Thursday, the main sfc system will lift out of the plains with the associated mid level wave. Though there may be pcpn ongoing Thur morning in the east, by afternoon most of the area should be pcpn free and the atmosphere should be able to recover before the next round of pcpn. Forecasted CAPE values will be 2000 to 2500 across a good portion of IL in the warm sector ahead of the front. A strong upper level jet will also be pushing into the area at the same time, so wind dynamics and shear will be sufficient that storms will likely rotate. There is still some uncertainty as to how this will play out Thur given the Wed night and early morning convection, but if airmass recovers, it looks like a line of convection will develop just west of the state late afternoon and then move east across the state Thur evening. All forms of severe weather look to be possible late afternoon through the evening hours. Something to consider is that storms may be moving at about 40-45 mph. By midnight, most of the storms should be east of the state, but will hang on to some chance pops. Past this system, dry conditions are expected for Fri through Sat night. Then another system moves toward the area for Sunday through Monday with more showers and storms. Expecting very warm temps for Thur, but then temps will cool some Fri and Sat, but warm back a tad for Sun and Mon. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 615 AM CDT TUE APR 7 2015 LIFR to VLIFR conditions in fog and low stratus will be the main forecast concern early on this morning, with a gradual improvement to MVFR cigs/vsbys by or shortly aftr 15z this morning. A stalled frontal boundary over central Illinois will not move much today with areas just to the south possibly seeing cigs improve to low VFR for a time this afternoon before all areas go back to IFR conditions again tonight. Timing and coverage of showers and TSRA rather complicated for today so VCSH or VCTS will be included in areas and times where we see the better threat. Surface winds will be east to northeast at BMI and PIA with speeds of 10 to 15 kts today, with surface winds more southeast in our southern TAF sites which were south of the stalled frontal boundary. Winds in those locations will also average from 10 to 15 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 11 AM CDT this morning FOR ILZ027>031- 036>038-040>057-061. && $$ UPDATE...07 SHORT TERM...Auten LONG TERM...Auten AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
705 PM EDT WED APR 8 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 400 PM EDT WED APR 8 2015 BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER 2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM. BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL DEPICTIONS OF WEAK CVA FORCING. OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR SOUTHEAST COUNTIES. && .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED APR 8 2015 PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY NIGHT. ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON. AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY. AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER. MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON. 0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY. THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE 00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1 KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING. TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE. AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS TO BUILD INTO THE AREA. A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING THE CWA FRIDAY INTO FRI NIGHT. ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME. AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME FRAME...MAINLY IN THE 60S AND LOW 70S. && .UPDATE/AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 703 PM EDT WED APR 8 2015 SIMILAR MESOSCALE DVLPMNTS COMPARED TO YDA AT THIS TIME ALTHOUGH CONVN IS STRUNG OUT A BIT FARTHER NORTH ALG OLD COMPOSITE OUTFLW/STNRY FNTL BNDRY THROUGH SRN IL/IN. UPSTREAM SVR CONVN OVR WRN MO XPCD TO GROW UPSCALE THIS EVENING AND DRIVE ENE THROUGH CNTRL IN LT TONIGHT. GIVEN CONCURRENT LACK OF LL FLW NORTH OF COMPOSITE BNDRY AND INHERENT POOR MSTR FLUX LOCALLY...HAVE AGAIN TRUNCATED POPS SHARPLY THROUGH 06Z YET RETAINED THE CAT RAMP THEREAFTER AS MUCH BTR LL MASS FLUX SHLD MATERIALIZE SW THIRD TWD 09Z AND BEYOND IN ACCORDANCE W/NR TERM GUIDANCE PROGS. EXTENT OF CAT POPS LIKELY TOO GENEROUS YET WILL AWAIT LTR GUIDANCE AND MONITOR UPSTREAM CONV EVOLUTION THIS EVENING BFR TRIMMING FURTHER IF NEEDED. ERLY VEERING TO SELY FLW NR TERM AT THE TERMINALS AGAIN POINTS TO IFR CIG DVLP LTR THIS EVENING AND LIKELY LIFR CONDS WILL BE REACHED SHLD SHRA/EMBEDDED TSRA DVLP AFT 06Z AS NR TERM GUIDANCE IMPLIES. HWVR MORE SIG ISSUE LOOKS TO BE STG AND GUSTY SWRLY GRADIENT FLW BY LT THU MORNING AS WARM SECTOR FINALLY MIXES NWD THROUGH THE TERMINALS. GUSTS TO 25-30KTS LIKELY BY AFTN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...AGD LONG TERM...MCD UPDATE/AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
105 PM CDT TUE APR 7 2015 .UPDATE... ISSUED AT 105 PM CDT TUE APR 7 2015 FRONTAL BOUNDARY STALLED ACROSS FAR NORTHERN MO WITH TEMPERATURES TO THE NORTH IN THE 40S WITH A NORTHEAST WIND AND TO THE SOUTH IN THE 60S TO LOWER 70S WITH A SOUTH WIND. SPC MESO ANALYSIS INDICATES 850 MB MOISTURE TRANSPORT WAS INCREASING OVER THIS BOUNDARY AND SHOWERS AND A FEW THUNDERSTORMS HAVE ERUPTED IN CENTRAL/NORTHERN IA AND INTO EXTREME SW MN. THE HRRR MODEL INDICATES SHOWERS AND A FEW THUNDERSTORMS WILL INCREASE THE DVN CWA AS THE AFTERNOON PROGRESSES...ESPECIALLY ACROSS OUR NORTHERN HALF CLOSER TO THE 850 MB BOUNDARY. HAVE ALREADY UPDATED TO LOWER TEMPERATURES SOME MORE...WITH MAXIMUM TEMPERATURES NOT REACHED UNTIL TOWARDS EVENING AS LOW PRESSURE ADVANCES TOWARDS KANSAS CITY AND WINDS BECOME MORE EASTERLY...RATHER THAN NORTHEAST. UPDATE ISSUED AT 1005 AM CDT TUE APR 7 2015 HAVE MADE SEVERAL CHANGES TO THE GRIDS...ADDING AREAS OF DENSE FOG IN OUR SOUTHERN CWA...GOING DRY THIS MORNING...LOWERING TEMPERATURES AND DEWPOINTS BY SEVERAL DEGREES. COLD FRONT THAT MOVED THROUGH THE CWA OVERNIGHT WAS STALLED ACROSS EXTREME NORTHERN MO. AS EXPECTED CONVECTION FORMED SOUTH OF OUR CWA AND CURRENTLY WAS MOVING THROUGH THE ST. LOUIS METRO AREA. SUBSIDENCE IN THE WAKE OF THE MCS WAS KEEPING THE DVN CWA DRY THIS MORNING. IN THE MEANTIME...DEWPOINTS IN THE 60S SOUTH OF THE BOUNDARY WAS OVERRUNNING THE FRONT AND PRODUCING WIDESPREAD LOW STRATUS. THIS ALONG WITH A NORTHEAST WIND WAS BRINGING DRIER AIR INTO MOST OF THE CWA AND KEEPING TEMPERATURES COOLER THAN FORECAST. THE MODELS CONTINUE TO STRUGGLE WITH THE DRY AIR. LOW PRESSURE IN KS WILL BE MOVING TO NEAR KANSAS CITY BY EVENING AND INITIAL CONVECTIVE DEVELOPMENT SHOULD OCCUR AHEAD OF THIS LOW IN NW MO EARLY THIS AFTERNOON...AND THEN SPREAD NORTHEAST INTO THE DVN CWA AS THE AFTERNOON PROGRESSES. HOWEVER...LOW STRATUS WILL BE PERSISTENT THROUGH THE DAY SO THUNDERSTORMS WILL BE ELEVATED AND THERE IS THE POTENTIAL FOR SMALL HAIL ESPECIALLY THIS EVENING. THE DENSE FOG IN OUR SOUTHERN CWA SHOULD IMPROVE BY NOON AND A SPECIAL WEATHER STATEMENT IS IN EFFECT TO COVER THIS SITUATION. && .SYNOPSIS... ISSUED AT 252 AM CDT TUE APR 7 2015 PORTIONS OF EASTERN IOWA AND NORTHERN ILLINOIS SAW THE FIRST REAL THUNDERSTORM ACTIVITY OF THE YEAR WITH CELLS FIRING ON THE NOSE OF MOISTURE TRANSPORT THAT QUICKLY THEN VEERED INTO INDIANA EARLY THIS MORNING. IN ITS WAKE...LOW LEVELS ARE SATURATED...WITH LIFT PRODUCING SHALLOW RAINS AND DRIZZLE OVER MUCH OF THE CWA THIS MORNING. ANOTHER BRANCH OF MOISTURE TRANSPORT IS AIMED AT NORTHWEST MISSOURI THROUGH EASTERN NEBRASKA...WHERE NEW THUNDERSTORMS ARE BEGINNING TO FORM. THIS NEXT THRUST OF RAINFALL IS LIKELY TO IMPACT OUR CWA TODAY AND TONIGHT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 252 AM CDT TUE APR 7 2015 ALL ELEMENTS OF THE FORECAST ARE CHALLENGING TODAY...AS THE SHARP CONTRAST IN TEMPERATURES ALONG THE FRONT COMBINE WITH HIGHLY VARIABLE CONVECTIVE SIGNALS IN MODEL DATA...WHILE WE BEGIN THE PERIOD WITH NARROW...BUT LONG BANDS OF DRIZZLE AND LIGHT RAIN. IN ANY CASE...AS ADVERTISED...IT WILL BE A DAMP DAY...AND COULD BE QUITE STORMY BEFORE IT IS OVER. WITH THUNDERSTORMS ALREADY FORMING OVER NORTHWEST MISSOURI INTO SOUTHEASTERN NEBRASKA...IT APPEARS THE CAPPING INDICATED BY THE 00Z NAM IS OVER DONE. THUS...I AM THINKING THE 00Z ECMWF SOLUTION MAY BE CLOSEST TO REALITY TONIGHT. THERE WILL BE AMPLE MUCAPE AVAILABLE FOR STORMS TODAY...ALL DAY AND ALL NIGHT. HOWEVER...THE SURFACE BOUNDARY SHOULD NOT LIFT NORTH THROUGH THE DAY...AND I FEEL STORMS WILL BE MOST ROBUST ON THE SOUTHERN FLANK OF WHERE THE PRIMARY RAIN AREA TRACKS. THAT IS SUPPORTED BY THE 00Z ECMWF...BUT IS ODDLY INVERTED ON SOME MODELS TODAY...SHOWING THE MOST INTENSE CONVECTION ON THE NORTH FLANK OF RAIN...WHICH WOULD BE VERY ODD GIVEN INFLOW FROM THE SOUTH/SOUTHWEST. THUS...WITH A LOW TRACKING ALONG THE IOWA /MISSOURI BORDER TODAY...THAT PLACES THE CWA INTO A SYNOPTICALLY FAVORED LOCATION FOR SHOWERS AND THUNDERSTORMS...OCCURRING ON AN ELEVATED FRONTAL SURFACE. I WILL INCREASE POPS FROM WEST TO EAST AFTER MID MORNING...WITH LIKELY COVERAGE OVER THE NORTHERN 2/3RDS OF THE CWA IN THE AFTERNOON AND EVENING. OVERNIGHT...THE BOUNDARY LINGERS OVERHEAD...WITH MUCAPE STILL AVAILABLE...BUT THE MOISTURE TRANSPORT/LLJ SHOULD BE FOCUSED MORE TO THE EAST BY THEN. WHILE THE NEXT ROUND OF SYNOPTIC LIFT WILL NOT ARRIVE TO LATER WEDNESDAY. POPS WILL BE NEEDED THROUGH OUT THE DAY DAY DUE TO THE LOW LEVEL PROCESSED CONTINUING TO PRODUCE THE LIGHT RAIN/DRIZZLE BEFORE ANY CONVECTION ARRIVES. TEMPERATURES TODAY WILL BE BASED ON 10 TO 15 DEGREE MODEST RISE DIURNALLY UNDER CLOUDY SKIES. FOR THE NORTH...THIS MEANS MOST OF THE DAY SPENT IN THE 40S...WITH EAST WINDS. THE SOUTH IS MOST LIKELY TO SQUEEZE OUT A MILD DAY AS THE ELEVATED RAIN PROCESSES SHOULD NOT CONSISTENTLY AFFECT THEM. TONIGHT MUCH LIKE THE CURRENT NIGHT...LAKE ENHANCED COLD AIR WILL SWEEP SOUTH AS THE LOW PRESSURE WAVE RIDES TO THE EAST. UPPER 30S NORTH TO LOWER 50S SOUTH ARE SUPPORTED BY MODEL DATA AND SEEM A LIKELY FIT. ERVIN .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 252 AM CDT TUE APR 7 2015 A PROGRESSIVE PATTERN IS SETTING UP FOR THE LONG TERM WITH A PAIR OF UPPER LEVEL TROUGHS PROGGED THROUGH THE CENTRAL U.S. INTO EARLY NEXT WEEK. PLENTY OF OPPORTUNITIES FOR RAIN AND A FEW CHANCES FOR SEVERE WEATHER ARE INDICATED. WEDNESDAY...THE UPPER LEVEL TROUGH TAKES SHAPE IN THE INTERMOUNTAIN WEST WHILE SURFACE LOW PRESSURE AND THE LOW-LEVEL JET FOCUS ON LIFTING A WARM FRONT INTO THE CWA. THE SURFACE BOUNDARY LINGERS IN THE SOUTHERN CWA WHILE THE 850 MB FRONT IS FORECAST TO MOVE INTO THE NORTHERN CWA. INSTABILITY AND SHEAR ARE SUFFICIENT FOR A SEVERE WEATHER THREAT PRIMARILY IN THE SOUTHERN PART OF THE CWA LATER IN THE DAY AND OVERNIGHT. THIS WILL DEPEND THE ON THE NATURE OF CONVECTIVE DEVELOPMENT EARLIER IN THE DAY TO THE SOUTHWEST IN THE SOMEWHAT CAPPED ENVIRONMENT. MID-LEVEL LAPSE RATES ARE VERY STEEP WHICH WOULD INDICATE POTENTIAL FOR RAPIDLY DEVELOPING STORMS. THURSDAY...THE UPPER LEVEL TROUGH MOVES INTO THE MIDWEST AND INTENSIFIES WHILE THE INSTABILITY AXIS...STEEP MID-LEVEL LAPSE RATES AND HIGH SHEAR ENVIRONMENT PERSIST OVER THE AREA. MODELS DISAGREE SOMEWHAT IN THE DETAILS OF THE TIMING AND PRECISE TRACK OF THE SURFACE LOW AND COLD FRONTAL PASSAGE...BUT THE CONSENSUS FAVORS THE LOW MOVING THROUGH OR NEAR THE CWA NEAR PEAK HEATING. THIS SUGGESTS THE FULL RANGE OF SEVERE WEATHER THREATS...AND GIVEN THE ENVIRONMENT AND TIME OF YEAR...THIS COULD BE A SIGNIFICANT EVENT WITH RAPIDLY DEVELOPING AND FAST-MOVING SUPERCELLS. FRIDAY AND SATURDAY...THE TROUGH MOVES EAST AND HIGH PRESSURE BUILDS INTO THE AREA WITH DRY AND PLEASANT WEATHER. SUNDAY AND MONDAY...THE SECOND TROUGH BEGINS TO TAKE SHAPE IN THE WESTERN U.S. AND MOVES INTO THE MIDWEST. INSTABILITY IS NOT TOO IMPRESSIVE...AND CURRENT MODEL FORECASTS SEEM TO SUGGEST MORE OF A HEAVY RAIN THREAT THAN A SEVERE THREAT. BUT THAT COULD CHANGE BETWEEN NOW AND LATE THIS WEEKEND. WOLF && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 105 PM CDT TUE APR 7 2015 MAINLY IFR CONDS THROUGH THE TAF CYCLE ALONG WITH INCREASING SHOWERS AND THUNDERSTORMS. NORTHEAST TO EAST WINDS 10 TO 20 KNOTS THROUGH THE TAF CYCLE. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...HAASE SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...WOLF AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
922 PM MDT WED APR 8 2015 .UPDATE... ISSUED AT 922 PM MDT WED APR 8 2015 ISSUED A LARGE UPDATE TO AMEND SKY...WEATHER AND POP GRIDS FOR THIS EVENING THROUGH TOMORROW EVENING. FOG/STRATUS HAS PUSHED FARTHER SOUTH THAN MOST GUIDANCE ONCE AGAIN. HRRR AND RUC HAVE LOCKED ONTO STRATUS WHILE OTHER GUIDANCE PERSISTS WITH A POOR FORECAST. ALSO...INCREASED POPS TO ACCOUNT FOR SHOWERS...STORMS AND DRIZZLE TONIGHT AND SHOWERS/DRIZZLE TOMORROW. THE FOG/DRIZZLE SETUP IS ESSENTIALLY IDENTICAL TO THE PREVIOUS TWO NIGHTS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 153 PM MDT WED APR 8 2015 AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL MOVE IN BEHIND THE TROUGH THURSDAY. PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY. DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING. DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP THOSE IN THE FORECAST. BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT. VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING. EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO THE LOWER 50S TO MID 50S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 107 PM MDT WED APR 8 2015 SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT. TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL. SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO 2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL. CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY. NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH TEMPERATURES ABOVE TO MUCH ABOVE NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 553 PM MDT WED APR 8 2015 STRATUS WILL BE AN ISSUE TONIGHT. STRATUS ADVANCES SOUTHEAST TOWARD KGLD BUT UNSURE OF EXACT ARRIVAL TIME. FOR NOW...FORECAST ARRIVAL BETWEEN 04-06Z. LATEST HRRR FORECAST INDICATES STRATUS REACHES KGLD WHILE OTHER GUIDANCE IS LESS PESSIMISTIC SO SIDED WITH HRRR WHICH HANDLED STRATUS WELL LAST NIGHT. ANOTHER CONCERN IS A COLD FRONT SLIDES THROUGH EARLY TOMORROW MORNING. THIS LEADS TO LIFTING STRATUS AS DRIER AIR ADVECTS IN. IN ADDITION TO DRIER AIR...ANTICIPATE GUSTY NORTHWEST WINDS TO DEVELOP BY LATE MORNING. AS FOR PRECIPITATION CHANCES...DO NOT FEEL PRECIPITATION WILL BE WIDESPREAD ENOUGH THIS EVENING TO INCLUDE A MENTION IN TAFS AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS WICHITA KS
710 PM CDT WED APR 8 2015 .MESOSCALE DISCUSSION... ISSUED AT 710 PM CDT WED APR 8 2015 MAIN SUPERCELL ACROSS BARBER COUNTY SEEMS TO BE THE MAIN EVENT ACCORDING TO THE LATEST TRENDS ON RADAR AND NWP. LOOKING AT CONVECTIVE TRENDS ACROSS OKLAHOMA...THEY HAVE BEEN HEADING DOWNWARD...AS IS EVEN THE CASE IN THE BARBER/COMANCHE STORM. LOW LEVEL FLOW HAS BEEN INCREASING WHICH HAS BEEN SUPPORTING BRIEF TORNADOES WITH THAT STORM WITH INCREASED LOCAL HELICITY. EXTRAPOLATING THE CURRENT MOVEMENT WOULD BRING IT INTO THE FORECAST AREA /KINGMAN COUNTY/ ABOUT 01Z. SPC ANALYSIS/LAPS ANALYSIS AND RAP FORECASTS FOR THE LAST 3 RUNS CONTINUE TO SHOW A TRANSITION OF THE MOST FAVORED AREA FOR TORNADOES TO HAVE SHIFTED WEST. THE LOW LEVEL HELICITY AREA REMAINS WEST OF THE FORECAST AREA ASSOCIATED WITH THE TRIPLE POINT. MOREOVER...SEEMS THAT AS THE STORMS MOVE EAST THEY GET INTO AN ENVIRONMENT THAT HAS DECREASED HELICITY AND IS JUST NOT AS FAVORABLE GIVEN THAT THE EARLIER CONVECTION MAY HAVE ALTERED THE ENVIRONMENT ENOUGH TO DECREASE THE THREAT. IN SUMMARY...THINK THE STORM THAT IS ONGOING IS THE MAIN THREAT AS ARE SOME OF THE STORMS COMING FROM OKLAHOMA. OTHERWISE...CONFIDENCE IS DECREASING IN THE AMPLITUDE OF THE THREAT FOR THE FORECAST AREA. KRC && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 245 PM CDT WED APR 8 2015 THIS EVENING-TONIGHT: LATEST SURFACE ANALYSIS SHOWS MAIN SURFACE BOUNDARY LOCATED JUST TO THE SE OF ICT METRO...MAINLY FROM EUREKA TO MULVANE TO WELLINGTON. THE INITIAL ROUND OF CONVECTION HAS ALREADY BEGUN OVER SRN KS...WITH MULTICELL STORMS PRODUCING MAINLY HAIL AND DAMAGING WINDS. THIS INITIAL ROUND OF STORMS WILL STAY IN THE WARM SECTOR ACROSS SE KS FOR THE EARLY AFTERNOON HOURS. WITH THE MAIN CONCERN FROM THIS ROUND BEING LARGE HAIL AND DAMAGING WINDS GIVEN THE UNSTABLE AIRMASS AND FAVORABLE BULK SHEAR. LATEST SHORT TERM HI-RES MODELS CONTINUE TO SHOW THE BOUNDARY RETROGRADING BACK TO THE NORTH EARLY THIS EVENING BETWEEN 21Z-02Z... WITH A SIGNIFICANT INCREASE OF LOW LEVEL CAPE BACK TOWARDS THE KICT METRO. THIS IN CONJUNCTION WITH THE INCREASE IN BULK SHEAR FROM THE INCOMING DISTURBANCE COUPLED WITH THE LOW LEVEL JET WILL PRODUCE A SCENARIO VERY FAVORABLE FOR TORNADIC SUPERCELLS TO DEVELOP ALONG THE DRY LINE AS IT SHARPENS FOR AREAS TO THE WEST AND SW OF SOUTH CENTRAL KS. THIS WILL LEAD TO A SECOND POSSIBLY MORE SIGNIFICANT CHANCE OF STORMS FOR LATER THIS EVENING WELL AFTER DARK. LATEST HI- RES MODEL CONTINUE TO SHOW 0-8KM SHEAR IS VERY FAVORABLE FOR SUPERCELLS AND POSSIBLE LONG TRACK TORNADOES. INCREASED MLCAPE TO 2000-2500 J/KG AND LOWERING LCL LEVELS WOULD ALSO SUGGEST A STRONG TORNADO THREAT AS WELL. SO THIS SETUP WOULD STILL LEAD TO HIGH LIKELYHOOD OF THE TORNADO THREAT CONTINUING WELL AFTER DARK FOR AREAS AREAS ACROSS SOUTH CENTRAL KS...MAINLY ALONG OR SOUTH OF HIGHWAY 54/400. EXPECT THE SEVERE CONVECTION TO CONTINUE FOR THE OVERNIGHT HOURS...WITH PROGRESSION OF THE STORMS TO THE EAST INTO THE FLINT HILLS AND SOUTHEAST KS. DEEP LAYER SHEAR LOOKS TO WANE SOME AFTER MIDNIGHT...WHICH WILL LIKELY SHIFT THE SEVERE WEATHER MODE TO MORE OF A LARGE HAIL AND DAMAGING WIND CHANCE. THU: COULD SEE SOME LINGERING STORMS ACROSS PORTIONS OF SOUTHEAST KS IN THE MORNING HOURS AS THE DRY LINE/BOUNDARY SURGES EAST INTO WRN MO. IT NOT COMPLETELY OUT OF THE REALM OF POSSIBILITY THAT SOME LINGERING STRONG STORMS WILL BE OVER SE KS...BUT THIS CHANCE WILL BE SHORT LIVED. EXPECT THE THU AFTERNOON SEVERE THREAT TO OVER EXTREME SE KS AND MAINLY IN SW MO. WITH THE REST OF THE REGION SEEING NICE WEATHER RETURN TO THE AREA...WITH DRIER AIR MOVING INTO THE AREA. FRI-EARLY SAT: A COUPLE OF NICE DAY EXPECTED FOR FRI AND EARLY SAT AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE PLAINS INTO THE SRN PLAINS. THIS WILL LEAD TO NEAR SEASONAL TEMPS AND SUNNY SKIES IN MOST LOCATIONS. AS SATURDAY PROGRESSES...LOW LEVEL MOISTURE WILL RAPIDLY RETURN TO THE AREA FOR AREAS WEST OF THE FORECAST AREA FOR SAT AFTERNOON. COULD SEE SHOWERS AND THUNDERSTORMS DEVELOP TO THE WEST OF THE AREA AND POSSIBLY MOVE INTO SOME OF THE WRN PORTIONS OF COUNTY WARNING AREA BY SAT EVENING. SAT NIGHT: ISENTROPIC LIFT AND MOISTURE RETURN WILL CONTINUE OVER THE WRN HALF OF THE FORECAST AREA FOR SAT NIGHT. THIS MAY LEAD TO A CHANCE OF SHOWERS AND THUNDERSTORM COVERAGE INCREASING ACROSS MOST OF THE AREA FOR SAT NIGHT. KETCHAM .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 245 PM CDT WED APR 8 2015 MEDIUM RANGE MODELS DO DIFFER SOME ON HOW SUN AND MON WILL PLAY OUT. BUT BOT MODELS SUGGEST ANOTHER CHANCE OF THUNDERSTORMS ON SUNDAY...WITH POSSIBLE STRONG TO SEVERE STORMS. THE ECMWF LOOKS TO CLEAR THINGS OUT ON MON...WHILE THE GFS SUGGESTS A BOUNDARY MAY BE STATIONARY ACROSS SRN KS FOR MON. KETCHAM && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1208 PM CDT WED APR 8 2015 CONVECTION NOW DEVELOPING OVER OKLAHOMA WILL MOVE NORTHEAST INTO THE AIRSPACE AND CONTINUE WITH SEVERAL ROUNDS THROUGH 6Z. THIS WILL AFFECT ALL AIRPORTS AND FIELDS ALONG AND SOUTHEAST OF KSLN- KVNX. THESE STORMS WILL BE SEVERE AND SHOULD BE AVOIDED. FOG...WHICH CONTINUES TO AFFECT KHUT...KRSL...KSLN HAS BEEN SLOW TO BURN OFF. THINK IT SHOULD BE GONE BY 21Z. VFR CONDITIONS SHOULD PERSIST THROUGH 03Z...WITH FOG REDEVELOPMENT THERE POSSIBLE THROUGH 12Z. THE COLD FRONT WILL CLEAR THE AREA BY 14Z. && .FIRE WEATHER... ISSUED AT 245 PM CDT WED APR 8 2015 MAIN FIRE WEATHER CONCERNS LOOK TO ON THURSDAY. EVEN WITH PLENTY OF LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE OVER SOUTH CENTRAL AND SE KS DUE TO GUSTY SOUTH WINDS. HOWEVER...THE CRITICAL FIRE WEATHER DAY LOOKS TO BE THU. THIS IS WHEN STRONG NW WINDS WILL BE IN PLACE BY THE AFTERNOON HOURS ALONG WITH RH`S IN THE 35-45 PERCENT RANGE. WIND SPEEDS THU AFTERNOON WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 56 71 39 68 / 60 10 0 0 HUTCHINSON 52 67 37 68 / 40 10 0 0 NEWTON 54 67 38 67 / 50 10 0 0 ELDORADO 60 69 39 68 / 70 10 10 0 WINFIELD-KWLD 61 72 40 68 / 80 10 0 0 RUSSELL 46 63 35 67 / 20 10 10 0 GREAT BEND 46 64 35 67 / 20 10 0 0 SALINA 50 65 35 68 / 30 20 10 0 MCPHERSON 51 66 36 67 / 40 10 10 0 COFFEYVILLE 65 76 42 68 / 90 30 10 0 CHANUTE 64 73 41 68 / 90 30 10 0 IOLA 63 72 40 67 / 90 30 10 0 PARSONS-KPPF 64 74 41 68 / 90 30 10 0 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
553 PM MDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 153 PM MDT WED APR 8 2015 AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL MOVE IN BEHIND THE TROUGH THURSDAY. PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY. DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING. DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP THOSE IN THE FORECAST. BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT. VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING. EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO THE LOWER 50S TO MID 50S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 107 PM MDT WED APR 8 2015 SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT. TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL. SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO 2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL. CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY. NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH TEMPERATURES ABOVE TO MUCH ABOVE NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 553 PM MDT WED APR 8 2015 STRATUS WILL BE AN ISSUE TONIGHT. STRATUS ADVANCES SOUTHEAST TOWARD KGLD BUT UNSURE OF EXACT ARRIVAL TIME. FOR NOW...FORECAST ARRIVAL BETWEEN 04-06Z. LATEST HRRR FORECAST INDICATES STRATUS REACHES KGLD WHILE OTHER GUIDANCE IS LESS PESSIMISTIC SO SIDED WITH HRRR WHICH HANDLED STRATUS WELL LAST NIGHT. ANOTHER CONCERN IS A COLD FRONT SLIDES THROUGH EARLY TOMORROW MORNING. THIS LEADS TO LIFTING STRATUS AS DRIER AIR ADVECTS IN. IN ADDITION TO DRIER AIR...ANTICIPATE GUSTY NORTHWEST WINDS TO DEVELOP BY LATE MORNING. AS FOR PRECIPITATION CHANCES...DO NOT FEEL PRECIPITATION WILL BE WIDESPREAD ENOUGH THIS EVENING TO INCLUDE A MENTION IN TAFS AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ253-254. NE...NONE. && $$ SHORT TERM...FS LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
225 PM CDT TUE APR 7 2015 ...UPDATED FOR LONG TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH ABOUT 8 AM CDT. THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON. FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR THAT AREA. TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS. MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA AS WELL. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 208 PM CDT TUE APR 7 2015 THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION WILL PASS ACROSS CENTRAL KANSAS BY THURSDAY AFTERNOON, WITH THE ACCOMPANYING COLD FRONT PASSING IN THE MORNING. COOL, SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS THROUGH FRIDAY. WITH LIGHT WINDS THURSDAY NIGHT, TEMPERATURES WILL FALL INTO THE 30S, WITH SOME READINGS CLOSE TO FREEZING FROM DODGE CITY WESTWARD AND NORTHWARD. HIGHS WILL BE IN THE 60S THURSDAY AND FRIDAY. THERE IS CONSIDERABLE UNCERTAINTY WITH RESPECT TO THE EVOLUTION OF NORTHERN AND SOUTHERN STREAM SHORTWAVE TROUGHS PROGRESSING INTO THE DESERT SOUTHWEST AND NORTHERN ROCKIES BY SUNDAY. SURFACE PRESSURES WILL LOWER IN THE LEE OF THE ROCKIES IN RESPONSE TO THESE SYSTEMS LATER FRIDAY INTO SATURDAY AND SUNDAY, ALONG WITH A GRADUAL INCREASE IN LOW LEVEL MOISTURE. A FEW RAIN SHOWERS AND THUNDERSTORMS CAN`T BE RULED OUT STARTING SATURDAY, WITH CHANCES LINGERING INTO SUNDAY NIGHT. COVERAGE OF SHOWER ACTIVITY IS VERY UNCERTAIN DUE TO THE WIDE RANGE OF MODEL SOLUTIONS WITH THE UPPER TROUGH PROGRESSING FROM THE DESERT SOUTHWEST TOWARD THE SOUTHERN HIGH PLAINS. OVERNIGHT LOWS WILL OF COURSE BE INCREASING THROUGH SUNDAY DUE TO THE LEE TROUGHING, SOUTH WINDS AND HIGHER DEWPOINTS. A MORE AMPLIFIED UPPER LEVEL TROUGH WILL BEGIN TO DEVELOP OVER THE WESTERN UNITED STATES MONDAY THROUGH WEDNESDAY OF NEXT WEEK, RESULTING IN LEE TROUGHING ON THE HIGH PLAINS, SOUTHERLY WINDS AND WARMER TEMPERATURES. CHANCES OF SHOWERS AND THUNDERSTORMS WILL INCREASE BY MID TO LATE NEXT WEEK AS THE UPPER TROUGH GETS CLOSER AND ASSOCIATED COLD FRONT APPROACHES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1119 AM CDT TUE APR 7 2015 AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE OBSERVATIONS. && .PRELIMINARY POINT TEMPS/POPS... DDC 48 83 45 66 / 10 10 10 10 GCK 46 80 41 63 / 10 10 10 10 EHA 47 81 42 64 / 10 0 10 10 LBL 46 85 43 66 / 10 0 0 0 HYS 44 69 45 62 / 20 20 20 20 P28 55 86 52 72 / 10 20 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 9 PM CDT /8 PM MDT/ WEDNESDAY FOR KSZ061>063-074>078-084>089. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR KSZ080-081-090. && $$ SHORT TERM...GERARD LONG TERM...FINCH AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
1256 PM CDT TUE APR 7 2015 ...UPDATED FOR 18Z AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 334 AM CDT TUE APR 7 2015 IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST- CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW LEVEL SHEAR. SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM. THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS. THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW LEVEL MOISTURE. STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135. THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE THE BEST CHANCES AT SHOWERS AND STORMS. LAWSON && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1253 PM CDT TUE APR 7 2015 VARIABLE WEATHER WILL BE NOTED DURING THIS FORECAST PERIOD. A SURFACE FRONT CURRENTLY RESIDES ALONG THE FLINT HILLS AND SHOULD RETROGRADE BACK INTO SOUTH CENTRAL KANSAS ON WEDNESDAY. THE INFLUX OF HIGHER DEWPOINTS AND THE FORECAST UPLOPE FLOW WILL PRODUCE LOW STRATUS OR STRATOCUMULUS DURING THE OVERNIGHT AND EARLY MORNING HOURS WEDNESDAY. VSBYS SHOULD ALSO SEE SOME RESTRICTIONS WITH THE LOW CLOUDS. IFR CONDITIONS ARE POSSIBLE AT MOST LOCATIONS SO KEEP AN EYE ON THE FORECAST. STRONG THUNDERSTORMS ARE POSSIBLE AT CNU THIS EVENING AND AT MOST LOCATIONS ON WEDNESDAY. && .FIRE WEATHER... ISSUED AT 310 PM CDT MON APR 6 2015 THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE LOOKS TO BE THURSDAY. EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 83 64 84 55 / 10 10 30 30 HUTCHINSON 80 56 80 51 / 0 10 30 20 NEWTON 83 58 81 53 / 10 10 30 30 ELDORADO 84 65 82 59 / 10 20 30 40 WINFIELD-KWLD 85 65 83 60 / 10 10 30 30 RUSSELL 71 48 70 47 / 10 10 20 20 GREAT BEND 75 50 74 47 / 10 10 20 10 SALINA 75 52 73 50 / 10 10 30 30 MCPHERSON 79 55 77 50 / 10 10 30 30 COFFEYVILLE 83 65 81 65 / 10 20 30 40 CHANUTE 83 65 80 64 / 10 30 30 50 IOLA 83 64 79 63 / 10 30 40 50 PARSONS-KPPF 83 65 81 64 / 10 20 30 50 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1150 AM CDT TUE APR 7 2015 ...UPDATED FIRE WEATHER DISCUSSION... .SYNOPSIS... ISSUED AT 1119 AM CDT TUE APR 7 2015 AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE OBSERVATIONS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH ABOUT 8 AM CDT. THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON. FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR THAT AREA. TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS. MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA AS WELL. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 319 AM CDT TUE APR 7 2015 AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING. A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY AFTERNOON. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER 70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER 50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE AROUND 70 DEGREES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1119 AM CDT TUE APR 7 2015 AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE OBSERVATIONS. && .FIRE WEATHER... ISSUED AT 1149 AM CDT TUE APR 7 2015 A DRYLINE WILL BE LOCATED ACROSS SOUTH CENTRAL KANSAS BY LATE DAY WEDNESDAY. UNSEASONABLY WARM CONDITIONS COMBINED WITH DRY AIR SPREADING EAST ACROSS SOUTHWEST KANSAS BEHIND THIS DRYLINE WEDNESDAY AFTERNOON WILL RESULT IN RELATIVE HUMIDITY VALUES FALLING BACK INTO THE 10 TO 15 PERCENT RANGE. THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST WINDS OF 20 TO 25 MPH WILL CREATE A FAVORABLE ENVIRONMENT FOR ANY OPEN FIRES TO SPREAD QUICKLY AND BE DIFFICULT TO CONTROL. AS A RESULT WILL BE UPGRADING THE MOST OF THE FIRE WEATHER WATCH TO A RED FLAG WARNING. OUT DOOR BURNING ON WEDNESDAY SHOULD BE AVOIDED. && .PRELIMINARY POINT TEMPS/POPS... DDC 79 48 83 46 / 0 10 10 10 GCK 77 46 80 42 / 0 10 10 10 EHA 83 47 81 43 / 0 10 0 10 LBL 84 46 85 44 / 0 10 0 0 HYS 69 44 69 46 / 10 20 20 20 P28 83 55 86 53 / 10 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 9 PM CDT /8 PM MDT/ WEDNESDAY FOR KSZ061>063-074>078-084>089. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR KSZ080-081-090. && $$ SYNOPSIS...BURGERT SHORT TERM...GERARD LONG TERM...HOVORKA_42 AVIATION...BURGERT FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 AM CDT TUE APR 7 2015 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1119 AM CDT TUE APR 7 2015 AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE OBSERVATIONS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH ABOUT 8 AM CDT. THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON. FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR THAT AREA. TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS. MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA AS WELL. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 319 AM CDT TUE APR 7 2015 AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING. A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY AFTERNOON. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER 70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER 50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE AROUND 70 DEGREES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1119 AM CDT TUE APR 7 2015 AT 12Z TUESDAY A 500MB LOW WAS LOCATED JUST OFF THE COAST OF NORTHERN CALIFORNIA. A SOUTHWESTERLY FLOW WAS PRESENT IN THE 700MB AND 500MB LEVEL FROM BAJA CALIFORNIA TO THE CENTRAL PLAINS WITH SEVERAL SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN THIS SOUTHWESTERLY FLOW. A SURFACE BOUNDARY EXTENDED FROM SOUTH CENTRAL KANSAS INTO SOUTHEAST COLORADO WITH LOW CLOUDS AND STATUS OBSERVED NORTH OF THIS BOUNDARY BASED ON SATELLITE AND SURFACE OBSERVATIONS. && .PRELIMINARY POINT TEMPS/POPS... DDC 80 49 84 46 / 0 10 10 10 GCK 79 46 81 42 / 0 10 10 10 EHA 83 47 81 43 / 0 10 0 10 LBL 85 46 85 44 / 0 10 0 0 HYS 70 46 69 46 / 10 20 20 20 P28 85 55 88 53 / 10 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR KSZ061>063-074>078-080-081-084>090. && $$ SYNOPSIS...BURGERT SHORT TERM...GERARD LONG TERM...HOVORKA_42 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
614 AM CDT TUE APR 7 2015 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH ABOUT 8 AM CDT. THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON. FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR THAT AREA. TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS. MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA AS WELL. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 319 AM CDT TUE APR 7 2015 AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING. A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY AFTERNOON. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER 70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER 50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE AROUND 70 DEGREES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 612 AM CDT TUE APR 7 2015 DENSE FOG WILL BE OBSERVED ACROSS THE DDC AND GCK TERMINALS THROUGH 14Z BRINGING LIFR CONDITIONS. SKIES THEN BECOME MOSTLY CLEAR THIS AFTERNOON. WINDS WILL GENERALLY BE FROM THE NORTH THIS MORNING INTO THE AFTERNOON, SHIFTING TO THE SOUTHEAST THIS EVENING. && .PRELIMINARY POINT TEMPS/POPS... DDC 80 49 84 46 / 0 10 10 10 GCK 79 46 81 42 / 0 10 10 10 EHA 83 47 81 43 / 0 10 0 10 LBL 85 46 85 44 / 0 10 0 0 HYS 70 46 69 46 / 10 20 20 20 P28 85 55 88 53 / 10 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR KSZ045-046-061>065-075>079. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR KSZ061>063-074>078-080-081-084>090. && $$ SHORT TERM...GERARD LONG TERM...HOVORKA_42 AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS WICHITA KS
613 AM CDT TUE APR 7 2015 ...UPDATED FOR 12Z AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 334 AM CDT TUE APR 7 2015 IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST- CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW LEVEL SHEAR. SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM. THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS. THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW LEVEL MOISTURE. STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135. THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE THE BEST CHANCES AT SHOWERS AND STORMS. LAWSON && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 609 AM CDT TUE APR 7 2015 POOR AVIATION CONDITIONS WILL CONTINUE TO LINGER ACROSS CENTRAL KANSAS THIS MORNING AS A COLD FRONT SAGS SLOWLY SOUTHWARD...WITH LOW CLOUDS AND PATCHY DENSE FOG. THE VISIBILITIES/LOW CLOUDS WILL GRADUALLY IMPROVE LATER THIS MORNING. MEANWHILE THE COLD FRONT WILL STALL OUT OVER SOUTHERN KANSAS BY THIS EVENING...WITH ISOLATED SEVERE STORMS POSSIBLE OVER SOUTHEAST KANSAS. THE FRONT WILL SLOWLY LIFT NORTHWARD AS A WARM FRONT TONIGHT...AND ONCE AGAIN LOW CLOUDS COULD FILL IN ALONG AND NORTH OF THE FRONT OVER CENTRAL KANSAS LATE TONIGHT. JAKUB && .FIRE WEATHER... ISSUED AT 310 PM CDT MON APR 6 2015 THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE LOOKS TO BE THURSDAY. EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 83 64 84 55 / 10 10 30 30 HUTCHINSON 80 56 80 51 / 0 10 30 20 NEWTON 83 58 81 53 / 10 10 30 30 ELDORADO 84 65 82 59 / 10 20 30 40 WINFIELD-KWLD 85 65 83 60 / 10 10 30 30 RUSSELL 71 48 70 47 / 10 10 20 20 GREAT BEND 75 50 74 47 / 10 10 20 10 SALINA 75 52 73 50 / 10 10 30 30 MCPHERSON 79 55 77 50 / 10 10 30 30 COFFEYVILLE 83 65 81 65 / 10 20 30 40 CHANUTE 83 65 80 64 / 10 30 30 50 IOLA 83 64 79 63 / 10 30 40 50 PARSONS-KPPF 83 65 81 64 / 10 20 30 50 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
407 AM CDT Tue Apr 7 2015 .SHORT TERM...(Today and Tonight) Issued at 407 AM CDT TUE APR 7 2015 Weak shortwave trough seen in water vapor imagery crossing eastern KS combined with warm advection above cap to create thunderstorms over northern MO this morning. This appears to be moving away, but have kept small chances in far northern/northeastern KS into the morning hours in an area of isentropic lift above cap. Better chances expected to be to north of forecast area over Nebraska during the day. Short range models consistent in bringing surface low from southwestern KS at 06Z Tuesday into northeast KS by 18Z. Thereafter it weakens the low into an inverted trough...as lee trough begins strengthening upstream in eastern CO. Low-level convergence along surface trough in east central KS late this afternoon/evening could trigger some surface based thunderstorms if lift is sufficient to overcome considerable capping inversion. Despite lack of large scale lifting mechanism, sufficient shear and instability should exist for the potential of isolated severe thunderstorms near the trough. While evening thunderstorm chances diminish after sunset, there is still a slight chance of elevated storms later tonight with lift up over the boundary that remains in vicinity of northeast/east central KS. Temps today are particularly tricky. Position of surface boundary and thicker cloud cover expected to hold down highs in far northern KS while upper 70s and lower 80s expected to the south of boundary. .LONG TERM...(Wednesday through Monday) Issued at 407 AM CDT TUE APR 7 2015 Wednesday and Wednesday night continue to be a concern regarding strong to severe thunderstorms. Models continue to show high surface dewpoints capped by a strong elevated mixed layer (EML). This sets the stage for large values of CAPE if a surface parcel is able to break through the cap. Deep layer shear of 40 to 50 KTS would be good enough for storms to become supercells. So there remains a chance for severe storms with large hail, damaging winds and tornadoes. The question is how limiting with the cap be in storm coverage. At this point there appears to be two surface features that may help shower and thunderstorm development. The first is a warm front that is expected to set up across northern KS Wednesday morning. Convergence and lift from the low level jet could cause some elevated storms to develop mainly north of the front. However all of the moisture seems to be trapped below the inversion with a lot of dry air above the cap. Because of this think chances for precip are not that great and have trended POPs down 5 to 10 percent. The more compelling feature will be a dryline that is progged to set up across central KS by the afternoon hours. Models show some mass convergence along this boundary through the afternoon as well as a modest PV anomaly lifting out across the central plains. Thinking is this may be enough forcing that local updrafts are able to break through the cap. With this in mind, have kept some likely POPs across east central KS in line with prev forecast, as most model guidance shows the same idea of storms developing on the dry line and moving northeast into east central KS through the evening. The concern however is that coverage could end up being pretty limited due to the strength of the cap and the forecast of likely POPs may signal for more widespread storms and severe weather. For Thursday, the models bring the main upper trough across the region. Current model runs continue to show the deeper moisture and instability pushing off to the east early in the day Thursday. Hove kept some small POPs in through the day for some possible shower activity with the upper trough axis. Otherwise we should see cooler and dryer air move in from the northwest with winds becoming gusty by the early afternoon. Highs are expected to be around 60 to the lower 70s due to increasing cold air advection. Friday and Friday night look to be dry and cool as surface ridging passes over the region. Models show return flow setting up for Saturday and Sunday. Think precip chances Saturday are only 20 percent due to no strong forcing progged by the models. However with warm air advection Saturday night and a surface wave moving through the region Sunday and Sunday night, precip chances will be on the increase. The best forcing looks to affect the forecast area Sunday afternoon and Sunday evening as models forecast increasing PVA. Think any lingering precip will be moving out of the area Monday. Temps through the weekend look to be seasonable as models keep the really warm air across the southwest. && .AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening) Issued at 647 PM CDT MON APR 6 2015 Complicated forecast leading to quite low confidence. Limiting stratus nearly out of all terminals but easterly winds developing should allow for redevelopment by 06Z. Guidance struggling to various degrees but stayed closer to RAP and GFS for build down to IFR and LLWS as jet increases. At this point convective chances in the 04Z-14Z period look too low to include, with TOP and FOE of more concern than MHK. Southwest winds should mix down as low pressure moves near/just NW of terminals around 18Z for return to VFR. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...GDP LONG TERM...Wolters AVIATION...65
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT TUE APR 7 2015 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 A COLD FRONT WAS SLOWLY PUSHING SOUTH ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING. MOIST UPSLOPE FLOW TO THE NORTH OF THE FRONT WAS RESULTING IN WIDESPREAD STRATUS AND FOG GENERALLY ALONG AND NORTH OF A LINE FROM LACROSSE TO NEAR DODGE CITY THEN WEST THROUGH GARDEN CITY AND SYRACUSE. AREAS IMMEDIATELY NORTH OF THE FRONT WERE SEEING DENSE FOG DEVELOP. THE PAST SEVERAL RUNS OF THE RUC13 AND HRRR HAVE BEEN INDICATING THIS AND THEY HAVE GENERALLY TENDED TO MOVE IT SLOWLY SOUTHWARD BEFORE DISSIPATING IT AFTER SUNRISE. WILL ISSUE A DENSE FOG ADVISORY FOR THIS AREA THROUGH ABOUT 8 AM CDT. THE FOG AND STRATUS SHOULD ERODE NORTHWARD THROUGH THE MORNING HOURS WITH AREAS ALONG I-70 SCATTERING OUT EARLY THIS AFTERNOON. FOR THE REST OF TODAYS FORECAST, HAVE ONLY MADE A FEW MINOR ADJUSTMENTS. THE FRONT MAY MOVE A LITTLE MORE SOUTHWARD THIS MORNING AS INDICATED BY THE SHORT TERM MODELS BUT THE SOUTHERN PORTION OF THE FRONT SHOULD MIX OUT THROUGH THIS AFTERNOON. MOS GUIDANCE IS PRETTY SIMILAR OVER WESTERN SECTIONS OF THE CWA BUT DIFFERS MORE IN THE EAST WHERE THE COOLER MET MOS KEEPS HIGHS IN THE UPPER 60S WHILE THE MAV GUIDANCE WARMS CENTRAL KANSAS INTO THE MID 70S. GIVEN THAT THERE WILL BE STRATUS ERODING THROUGH PART OF THE DAY, HAVE CONTINUED TO LEAN TOWARD THE COOLER GUIDANCE FOR THAT AREA. TONIGHT WILL SEE STRATUS REDEVELOPING ALONG WITH SOME PATCHY FOG AND DRIZZLE ESPECIALLY IN THE WAKEENEY, HAYS AND LACROSSE AREAS. MODEL SOUNDINGS ARE STILL SHOWING LOW LEVEL WARM ADVECTION MAXIMIZED IN THAT AREA AROUND OR AFTER MIDNIGHT. IF ANY PARCELS CAN GET LIFTED ENOUGH, THERE WILL BE SOME INSTABILITY ALOFT THAT COULD SUPPORT A FEW THUNDERSTORMS. WILL LEAVE A MENTION OF ISOLATED THUNDERSTORMS IN THAT AREA AS WELL. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 319 AM CDT TUE APR 7 2015 AN UPPER LEVEL LOW WILL BE POSITIONED OVER THE INTERMOUNTAIN WEST WEDNESDAY THEN TREK EASTWARD INTO THE CENTRAL ROCKIES WEDNESDAY NIGHT BEFORE SWINGING ACROSS NEBRASKA AND THE NORTHERN PLAINS THURSDAY. AT THE SURFACE, AN AREA OF LOW PRESSURE WILL INTENSIFY AS THE PREVIOUS FEATURE APPROACHES WITH A STALLED OUT FRONT EXTENDING EASTWARD ACROSS SOUTHERN KANSAS. PATCHY FOG WILL BE POSSIBLE NORTH OF THIS FRONT WHERE LIGHT WINDS AND AMPLE LOW LEVEL MOISTURE WILL BE FOUND. THIS FOG IS ONLY EXPECTED TO LAST A COUPLE OF HOURS AFTER SUNRISE WITH MOSTLY CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE DAY DUE TO MID LEVELS OF THE ATMOSPHERE BEING DRY. VERY DRY AIR WILL BE FILTERED IN FROM THE SOUTHWEST SOUTH OF THIS FRONT LEADING TO A DRYLINE ACROSS FAR SOUTHWESTERN KANSAS. IN ADDITION, A FEW THUNDERSTORMS COULD FORM AHEAD OF THIS DRYLINE DURING THE LATE AFTERNOON INTO THE EARLY EVENING. HOWEVER, ANY CONVECTION THAT DOES FORM WILL QUICKLY MOVE EASTWARD INTO WICHITA`S CWA. THE AREA OF LOW PRESSURE WILL QUICKLY MOVE EASTWARD ACROSS KANSAS WEDNESDAY NIGHT WITH A COOLER NORTHWESTERLY WINDS FELT BEHIND IT. MOISTURE WILL WRAP AROUND THIS SYSTEM BRINGING SCATTERED SHOWERS ACROSS PORTIONS OF THE PLAINS. HOWEVER, MOST OF THE LIFT WILL BE NORTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF SHOWERS ACROSS THE I-70 CORRIDOR EARLY THURSDAY MORNING. A QUIET PATTERN WILL BE IN PLACE THURSDAY NIGHT THROUGH FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA THURSDAY NIGHT THEN TREKS SOUTHEAST OF THE AREA FRIDAY. AN AREA OF LOW PRESSURE WILL ALSO DEVELOP ACROSS EASTERN COLORADO FRIDAY DUE TO A WEAK SHORTWAVE MOVING THROUGH THE NORTHERN ROCKIES. SKIES LOOK TO BE MOSTLY CLEAR DURING THIS PERIOD WITH WINDS BECOMING SOUTHERLY BY FRIDAY AFTERNOON. ATTENTION THEN FOCUSES ON THE WEEKEND AS AN UPPER LEVEL SHORTWAVE INTENSIFIES ABOVE THE DESERT SOUTHWEST THEN TRACKS EASTWARD ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. A LARGE DOME OF HIGH PRESSURE WILL BE IN PLACE ACROSS THE EASTERN UNITED STATES AS THIS FEATURE APPROACHES ALLOWING GULF MOISTURE TO BE PUSHED NORTH INTO THE PLAINS. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE WEEKEND WITH INCREASED CLOUD COVER. A QUIET PATTERN THEN RETURNS EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE SOUTHWEST UNITED STATES. AS FOR TEMPERATURES, HIGHS WEDNESDAY LOOK TO RANGE FROM THE LOWER 70S NORTH OF THE FRONT TO UPPER 80S ACROSS THE KS/OK BORDER WHERE THE VERY DRY AIR WILL BE IN PLACE. LOWS WEDNESDAY NIGHT LOOK TO RANGE FROM AROUND 40 DEGREES ACROSS WEST CENTRAL KANSAS TO LOWER 50S ACROSS SOUTH CENTRAL KANSAS. COOLER TEMPERATURES ARE EXPECTED BEHIND THE FRONT THURSDAY INTO FRIDAY WITH HIGHS IN THE 60S. LOWS THURSDAY NIGHT ARE FORECASTED TO DIP INTO THE 30S WITH LOWER 40S EXPECTED FRIDAY NIGHT. HIGHS REBOUND INTO THE 70S THIS WEEKEND WITH LOWS IN THE 40S TO LOWER 50S. HIGHS MONDAY THEN LOOK TO BE AROUND 70 DEGREES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1225 AM CDT TUE APR 7 2015 A WEAK COLD FRONT WILL MOVE THROUGH THE DODGE CITY AND GARDEN CITY TERMINALS BY THE BEGINNING OF THIS TAF PERIOD. WINDS WILL INITIALLY BE FROM THE NORTHEAST BEFORE GRADUALLY SHIFTING TO THE NORTH LATER TONIGHT. WE EXPECT TO SEE CEILINGS AND VISIBILITIES DROPPING INTO THE IFR TO OCCASIONALLY LIFR CATEGORY FOR A PERIOD OF TIME BEHIND THE FRONT THROUGH THE EARLY MORNING HOURS. CONDITIONS SHOULD IMPROVE TO VFR SHORTLY AFTER SUNRISE. && .PRELIMINARY POINT TEMPS/POPS... DDC 80 49 84 46 / 0 10 10 10 GCK 79 46 81 42 / 0 10 10 10 EHA 83 47 81 43 / 0 10 0 10 LBL 85 46 85 44 / 0 10 0 0 HYS 70 46 69 46 / 10 20 20 20 P28 85 55 88 53 / 10 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR KSZ045-046-061>065-075>079. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR KSZ061>063-074>078-080-081-084>090. && $$ SHORT TERM...GERARD LONG TERM...HOVORKA_42 AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS WICHITA KS
334 AM CDT TUE APR 7 2015 .SYNOPSIS... ISSUED AT 334 AM CDT TUE APR 7 2015 IN THE UPPER LEVELS...WE CURRENTLY HAVE A STRONG UPPER LOW APPROACHING NORTHERN CA WITH SW FLOW ALOFT SPREAD OVER THE ROCKIES INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS CENTERED OVER WEST- CENTRAL KS/FAR EASTERN CO WITH A STATIONARY FRONT STRETCHING FROM THE LOW PRESSURE ACROSS NORTHEAST KS AND CENTRAL MO. RICH LOW LEVEL MOISTURE CONTINUES TO STREAM NORTH FROM THE GULF WITH WIDESPREAD UPPER 60S DEW POINTS ACROSS EAST TX. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 THE UPPER LOW WILL SLOWLY TRACK EAST TODAY AND WILL BE APPROACHING THE CENTRAL GREAT BASIN TONIGHT. A DRY LINE WILL MIX EAST TODAY ACROSS WESTERN OK/TX WITH THE SYNOPTIC FRONT TAKING UP POSITION FROM NE TO SW ACROSS SE KS AND INTO NORTH CENTRAL OK. THE MAIN QUESTION WILL BE WHETHER STORMS CAN DEVELOP ALONG THESE BOUNDARIES LATE THIS AFTERNOON/EVENING. THE NAM AND GFS HAVE BOTH BACKED OFF ON THE AMOUNT OF CONVERGENCE OVER SE KS WITH THE RAP MUCH MORE AGGRESSIVE IN BREAKING OUT CONVECTION LATE THIS AFTERNOON. CURRENT THINKING IS THAT THERE IS STILL A CHANCE A STORM OR TWO COULD DEVELOP LATE THIS AFTERNOON OVER SE KS WITH ANOTHER CHANCE FOR ELEVATED STORMS AFTER DARK IN THIS SAME LOCATION ASSOCIATED WITH AN INCREASE IN 850-700MB MOISTURE TRANSPORT. ANY STORM THAT DEVELOPS EITHER THIS AFTERNOON OR TONIGHT WILL HAVE A GOOD CHANCE TO BE SEVERE. THE TORNADO THREAT WILL BE CONDITIONAL ON STORMS BEING ABLE TO DEVELOP IN THE 22-01Z TIME FRAME SO IT COULD STILL BE ROOTED IN THE BOUNDARY LAYER AND THUS TAKE ADVANTAGE OF THE LOW LEVEL SHEAR. SIGNIFICANT SEVERE STORMS STILL LOOK POSSIBLE WED AFTERNOON/EVENING ACROSS MAINLY SOUTH CENTRAL KS. QUITE CONSIDERABLE DIFFERENCES HAVE SHOWN UP BETWEEN THE GFS AND NAM. THE NAM HAS THE STATIONARY FRONT MUCH FURTHER SOUTH COMPARED TO THE GFS WHICH WOULD LIMIT SEVERE CHANCES OVER MUCH OF CENTRAL KS. THE NAM DOES HAVE SOME SUPPORT FROM THE 00Z ECMWF. THE MAIN QUESTION REGARDING STORMS WED AFTERNOON/EVENING ISN`T HOW SEVERE THEY WILL BE IF THEY DEVELOP...IT IS HOW MANY STORMS ARE ABLE TO DEVELOP. FEEL THAT WITH SOME SHORTWAVE ENERGY FINALLY KICKING OUT OF THE ROCKIES...AT LEAST A FEW STORMS WILL DEVELOP WED AFTERNOON/EVENING...ESPECIALLY NEAR THE TRIPLE POINT WHERE CONVERGENCE WILL BE MAXIMIZED. WITH 0-6KM SHEAR IN THE 45-55KT RANGE AND CAPE IN THE 2500-3000J/KG RANGE...ANY STORMS THAT DEVELOP WILL QUICKLY BECOME SEVERE. STORMS SHOULD BE ABLE TO STAY ISOLATED AS THEY MOVE OFF THE DRYLINE WITH THE DEEP LAYER SHEAR PERPENDICULAR TO THE BOUNDARY. THE NAM HAS QUITE A BIT MORE 0-3KM CAPE COMPARED TO THE GFS BUT FEEL IT MAYBE CLOSER TO REALITY AS IT SURPRISINGLY LOOKS TO HAVE A SLIGHTLY BETTER HANDLE ON THE LOW LEVEL MOISTURE. STORMS WILL TRACK EAST WED NIGHT AND AFFECT AREAS EAST OF I-135. THE UPPER SHORTWAVE WILL QUICKLY PUSH EAST AND WILL BE OVER WESTERN IA BY THU EVENING. THIS WILL ALLOW THE FRONT TO QUICKLY SLIDE EAST WITH ONLY FAR SE KS HAVING A SHOT AT STORMS THU MORNING. MEANWHILE...CENTRAL KS MAY GET IN ON SOME OF THE WARP AROUND SHOWERS ASSOCIATED WITH THIS SYSTEM ON THU. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 334 AM CDT TUE APR 7 2015 HIGH PRESSURE IS EXPECTED TO SLIDE OVER THE PLAINS FOR FRI ALLOWING FOR CLEAR SKIES AND TEMPS CLOSER TO SEASONAL NORMALS. AN ACTIVE SPLIT FLOW PATTERN LOOKS TO COMMENCE FOR THE WEEKEND AS A SERIES OF SHORTWAVES MOVE OUT OF THE ROCKIES AND ACROSS THE PLAINS. THE IMPULSE THAT SHOULD HAVE AN IMPACT ON OUR FORECAST AREA WILL LIFT OUT OF THE DESERT SW SAT AND INTO CENTRAL KS FOR SUN WITH A MORE SIGNIFICANT TROUGH SWINGING ACROSS THE PLAINS FOR MON. AT THIS TIME THE SAT NIGHT-SUN NIGHT TIME FRAME LOOKS TO HAVE THE BEST CHANCES AT SHOWERS AND STORMS. LAWSON && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1127 PM CDT MON APR 6 2015 CLEAR SKIES HAVE RETURNED TO THE AREA THIS EVENING...HOWEVER LOW CIGS WITH VISIBILITIES IN THE 3-5 RANGE ARE ANTICIPATED AFTER 08-10Z ACROSS BOTH CENTRAL KANSAS AND SOUTHEAST KANSAS. IFR/LIFR CIGS CONTINUE TO EXPAND NORTH OF THE STATIONARY FRONT AND ARE EXPECTED TO IMPACT THE KRSL AND KSLN AREAS FROM 08-10Z THROUGH AT LEAST 15Z BEFORE AN INCREASING WESTERLY COMPONENT ADVECTS DRIER AIR ACROSS THE AREA. FURTHER SOUTH AND EAST...MID AND UPPER 60 DEWPOINTS HAVE RESULTED IN NARROW T/TD SPREADS AND AREAS OF FOG AND LOW CIGS ARE EXPECTED TO REDEVELOP LATE TONIGHT/EARLY TUE. && .FIRE WEATHER... ISSUED AT 310 PM CDT MON APR 6 2015 THE MOST CRITICAL FIRE WEATHER DAY THROUGH THIS FORECAST PACKAGE LOOKS TO BE THURSDAY. EVEN WITH RICH LOW LEVEL MOISTURE...VERY HIGH FIRE DANGER WILL BE IN PLACE ACROSS SOUTH CENTRAL AND PARTS OF SE KS WED DUE TO STRONG SOUTH WINDS. WINDS WILL FLIP AROUND TO THE WEST AND NORTHWEST ON THU AT SPEEDS IN THE 20-30 MPH RANGE BY AFTERNOON HOURS. RH`S THU AFTERNOON WILL BE IN THE 30-40% RANGE. .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 83 64 84 55 / 10 10 30 30 HUTCHINSON 80 56 80 51 / 0 10 30 20 NEWTON 83 58 81 53 / 10 10 30 30 ELDORADO 84 65 82 59 / 10 20 30 40 WINFIELD-KWLD 85 65 83 60 / 10 10 30 30 RUSSELL 71 48 70 47 / 10 10 20 20 GREAT BEND 75 50 74 47 / 10 10 20 10 SALINA 75 52 73 50 / 10 10 30 30 MCPHERSON 79 55 77 50 / 10 10 30 30 COFFEYVILLE 83 65 81 65 / 10 20 30 40 CHANUTE 83 65 80 64 / 10 30 30 50 IOLA 83 64 79 63 / 10 30 30 50 PARSONS-KPPF 83 65 81 64 / 10 20 30 50 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
844 PM EDT Wed Apr 8 2015 ...Mesoscale Forecast Update... Issued at 830 PM EDT Wed Apr 8 2015 Strong to marginally severe convection across southern Indiana and much of central Kentucky is now pushing into the Bluegrass region. One renegade supercell near Owensboro weakened rapidly as it pushed eastward within the last hour, suggesting that our environment has been worked over, and observed temperatures are now in the upper 60s across most of the area. Warmer temps in south central Kentucky, but the environment is capped and the dynamical forcing aloft is also lacking. Will cut back on POPs as these storms exit the Bluegrass over the next hour or so, and work on canceling the Tornado Watch. The Flash Flood Watch is in effect and will be left in place, even though the flood threat won`t ramp up again until we get the next round of convection in sometime Thursday. .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (00Z TAF Update)... Updated at 645 PM EDT Wed Apr 8 2015 Scattered thunderstorms will continue across north central KY for the next few hours. These storms will continue to affect SDF and LEX off an on. Storms are expected to diminish by 03Z or so with drier conditions for much of the rest of the night. A few showers may develop around BWG over the next few hours, but storms are not expected at this time. The next complex of storms will begin to move in around 11-12Z. These will affect all TAF sites tomorrow morning, moving out early afternoon. Winds will increase tomorrow afternoon as a cold front begins to approach from the west. South-southwesterly winds will be sustained up to around 15 knots with gusts of 20-25 knots. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late Thursday night FOR KYZ023>025- 028>043-045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late Thursday night FOR INZ076>079-083- 084-089>092. && $$ Mesoscale......RAS Short Term.....EER Long Term......BJS Aviation.......EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
749 PM EDT WED APR 8 2015 .UPDATE... ISSUED AT 750 PM EDT WED APR 8 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER 05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 455 PM EDT WED APR 8 2015 THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN THE SMALL SCALE FEATURES AT PLAY. IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z. HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES. THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 521 PM EDT WED APR 8 2015 A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY. AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS LONG RANGE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 750 PM EDT WED APR 8 2015 AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH NORTHERN KENTUCKY THIS EVENING. EXPECT A FEW INSTANCES OF MVFR CONDITIONS...MAINLY IN AND AROUND THE HEAVY THUNDERSTORMS. THIS ACTIVITY WILL MOVE OFF TOP THE EAST BY 05Z AND SKIES WILL BEGIN TO CLEAR A BIT AS CLOUD COVER ASSOCIATED WITH THE ACTIVITY DISSIPATES. WITH THIS...MAY SEE A FEW AREAS OF FOG LATE TONIGHT AND HAVE PUT THIS INTO THE TAF SITES. CONDITIONS SHOULD BEGIN TO IMPROVE AFTER DAWN BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS DEVELOP LATE THURSDAY AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ044-050>052- 104. && $$ UPDATE...SHALLENBERGER SHORT TERM...JVM/GREIF LONG TERM...HAL AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
230 PM EDT TUE APR 7 2015 .UPDATE... ISSUED AT 1135 AM EDT TUE APR 7 2015 THUNDERSTORM COMPLEX WHICH RESULTED IN A FEW FLOODING REPORTS IN OUR SOUTHERN COUNTIES IS EXITING INTO TN AND VA. OTHER THUNDERSTORMS IN THE LMK AREA WERE HEADING TOWARD OUR NORTHERN COUNTIES...BUT WERE WEAKENING. HAVE ADJUSTED NEAR TERM POPS FOR THE OBSERVED RADAR TRENDS. WITH A MOIST AIR MASS...WARM AIR ADVECTION...A FRONTAL BOUNDARY JUST TO OUR NORTH...NO SIGNIFICANT CAP...AND WEAK IMPULSES PASSING THROUGH... REDEVELOPMENT/INTENSIFICATION WILL BE A POSSIBILITY AS SOME LIMITED DESTABILIZATION OCCURS THIS AFTERNOON. CONFIDENCE IN TIMING AND LOCATION IS LOW. HAVE LEANED TOWARD THE HRRR SOLUTION THIS AFTERNOON INTO TONIGHT...BUT KEPT THE FORECAST FAIRLY GENERALIZED. UPDATE ISSUED AT 800 AM EDT TUE APR 7 2015 DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 340 AM EDT TUE APR 7 2015 06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY. THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT... MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60 DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER CONDITIONS IN THE FAR SOUTHWEST. DEW POINTS...MEANWHILE...HAVE COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS PAST WEEKEND/S DRYNESS. THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS. SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO. USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 AM EDT TUE APR 7 2015 MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS THE OHIO RIVER VALLEY DURING THIS TIME. AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA. THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN 21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY AFTERNOON. EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 230 PM EDT TUE APR 7 2015 SHOWERS AND A FEW RUMBLES OF THUNDER WERE ONGOING OVER PORTIONS OF THE FORECAST AREA AT THE START OF THE PERIOD...ESPECIALLY NORTH OF A LINE FROM MOUNT STERLING TO PAINTSVILLE. WILL LOOK FOR MOST OF THE ACTIVITY TO WEAKEN AND MOVE OUT TO THE EAST DURING THE COURSE OF THE AFTERNOON. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE FORECAST PERIOD. HOWEVER...THERE IS LOW CONFIDENCE AS TO WHEN/WHERE THEY MAY OCCUR. FOR THAT REASON...HAVE ONLY USED VCTS AFTER THIS AFTERNOON. IN TERMS OF CONDITIONS...MVFR COULD OCCUR WITH THE PRECIP. OUTSIDE OF THIS...WILL LOOK FOR LARGELY VFR. THE TAFS ARE WRITTEN IN A GENERALIZED FASHION DUE TO LOW FORECAST CONFIDENCE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...JMW AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
120 PM EDT Tue Apr 7 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 1149 AM EDT Tue Apr 7 2015 The complex of showers and thunderstorms will continue to push east along the I-64 corridor for the next hour or two. They are looking less organized but will still be capable of frequent cloud to ground lightning and brief heavy rainfall. Focus is now shifting to the west where the previous supercell has now evolved into a growing linear segment crossing the Mississippi River near St. Louis. This feature is expected to continue ESE or SE toward our region through the early afternoon, growing as it does so. Already seeing good destabilization across west central KY where some clearing has occurred, and do expect a 1500 - 2500 J/KG instability axis to setup along and west of I-65 during peak heating. Some of the southern Indiana counties where this morning`s complex passed may struggle to get as unstable. Will also note that 0-6 km bulk shear should range between 30-40 knots, sufficient for continued organization. Forecast sounding are quite impressive if they verify and would suggest a severe wind and hail threat with the strongest storms. In collaboration with the Storm Prediction Center, mention of an upgrade to a slight risk is a possibility across western portions of our CWA this afternoon. Right now the best timing for the CWA looks to be between 3 PM EDT and 9 PM EDT. Do want to mention that another round of heavy rain will accompany the potential severe threat with this next round of convection. Depending on where heaviest rain falls, more hydro products may be needed. Previous Update... Issued at 919 AM EDT Tue Apr 7 2015 Storms will wind down along the I-64 corridor through the late morning hours. However, will have to keep an eye on the stronger cluster currently over southern Indiana as it moves ESE toward the Kentucky Bluegrass region. Very intense rainfall has left 2 to 3 inches in a short amount of time across small portions of southern Indiana and will keep the Flash Flood Warning going across Orange/Washington counties for the time being. Have upped pops and QPF to account for this cluster. Hail will also be possible with this storm. Focus will then shift to this afternoon and evening as another round of storms will be possible. Looking upstream, an impressive supercell is tracking ESE along I-70 and the warm front toward St. Louis. This feature is expected to turn more SE along the instability gradient through the late morning and early afternoon, and grow into a more linear complex. Do expect to get some partial clearing which will aid an already destabilizing atmosphere. SREF probabilities of greater than 1000 J/KG of CAPE this afternoon are likely along and west of I-65. 0-6 km shear values between 30 and 40 knots this afternoon would also support organization. Will have to watch how things progress through the late morning as there is some concern for strong to severe storms this afternoon and evening. The 06z NAM and HRRR are handling the current situation pretty well. However the NAM is a bit too far north and a couple hours slow. Did the afternoon forecast based off this solution with adjustments for timing placement. Adjusted QPF upward as well in anticipation of the afternoon storms. .SHORT TERM (Now through Wednesday)... Issued at 257 AM EDT Tue Apr 7 2015 The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good handle on an area of showers and embedded thunderstorms moving from southeast Illinois into the lower and middle Ohio Valley at 07Z this morning. The storms are ahead of an upper level disturbance coming in from the lower and middle Mississippi Valley. This convective complex will continue to spread eastward this morning along and a few counties either side of the I-64 corridor. Though the showers and storms will mostly be garden variety, a few gusts of wind or instances of small hail in the strongest cores can`t be entirely ruled out. The morning showers and storms will have moved off to the east by early afternoon. This afternoon another weak upper wave will come in from the west. Though some stabilization will occur over southern Indiana and northern Kentucky from the morning rain, additional scattered shower and thunderstorm development will be possible, albeit with less coverage than what we see this morning. Again, a few strong storms will be possible. With plenty of moisture available, locally heavy downpours will be possible with the thunderstorms. The cells should be progressive, but there will be some training this morning in southern Indiana and north central Kentucky. Decided to drop max temps a few degrees in the north where more rain and clouds will prevail through the morning hours, but still have 70s everywhere for highs this afternoon. After a lull this evening, more shower and thunderstorm development will be possible late tonight as the next weak upper wave comes in from the west after midnight. Low temperatures will be in the lower and middle 60s. The relatively low confidence forecast today and tonight becomes even lower on Wednesday. We will remain in the same warm, juicy air mass as today, south of a stationary surface front from Illinois to Ohio. The late night showers/storms tonight will likely persist into Wednesday morning, with redevelopment possible Wednesday afternoon especially near any leftover convective boundaries from the morning activity. Highs should be in the middle and upper 70s...maybe an 80 degree reading if we can get enough sunshine in the afternoon. .LONG TERM (Wednesday Night through Monday)... Issued at 235 AM EDT Tue Apr 7 2015 The focus in the long term period is on thunderstorm chances/timing Wednesday night through Friday. The upper level pattern Wednesday night is expected to feature a digging trough from the Rockies into the central Plains with downstream ridging extending from the Gulf Coast through the southern Great Lakes region. At the surface, a warm and moist air mass characterized by dewpoints in the 60s will be in place thanks to a developing surface low to our west. Stronger southerly flow should make for a mild night with lows only falling into the mid 60s. The focus for thunderstorm initiation Wednesday night is favored to our west where the strengthening low-level jet impinges on an east-west boundary across Illinois. These storms could then take an east/southeast track across portions of the area. Strength/severity a bit more uncertain as elevated instability wanes considerably and effective shear is not as impressive but a few elevated stronger storms would be possible. Kept POPs in the 30-50 percent range, tapered highest to lowest from southern Indiana to southern Kentucky respectively. The main upper level trough will advance eastward Thursday as the surface low deepens/lifts to Wisconsin by Thursday night. 07.00z guidance remained overall similar to earlier runs in its progression, bringing the cold front through the local area late Thursday night into Friday morning. Scattered showers and thunderstorms are possible ahead of the main system though coverage isn`t expected to be very high. Decaying strong thunderstorms look to be approaching our western borders during the late evening, and if enough elevated instability remains present, a marginal wind threat exists. Overall, the system looks fairly progressive, limiting the training heavy rainfall threat as well. Ahead of the front, a very warm air mass will be in place. Depending on how cloud cover fares, we`ll be approaching 80 degrees in most spots Thursday. A mild night would then set up with lows in the mid 60s to near 70 degrees. Friday looks to be our transition day as the front sweeps across the area. Will keep chance POPs in the morning to early afternoon hours, especially east of I-65 before clearing conditions work in for the evening. Seasonable, pleasant and mostly sunny conditions thanks to surface high pressure expected Saturday into the first part of Sunday. A model consensus approach gives highs in the mid to upper 60s Saturday and upper 60s to low 70s Sunday. Increasing moisture and southerly return flow sets up Sunday night into early next week as the surface high moves to our east. A slow ramp up in POPs, still chance, will be advertised as deterministic models show another system lifting through the central Plains to lower Great Lakes. Seasonable to above seasonable temperatures look reasonable at this time. && .AVIATION (18Z TAF Update)... Updated at 120 PM EDT Tue Apr 7 2015 We`re in a relative lull with convection with only some storms hanging around LEX for another hour or two. Warm sector has become firmly established over the area and should see mostly VFR conditions as skies partially clear through much of the afternoon. Expect a steady south wind around 10 mph with a few higher gusts possible. Focus is upstream on the next convective complex set to move into the TAF sites from late afternoon through evening. Best timing at SDF is expected between 5 and 10 PM EDT where visibilities could drop into the IFR range in heavier thunderstorms. Stronger wind gusts and some hail will also be possible with the strongest storms. LEX/BWG should see weaker convection and a couple hours later than at SDF. There should be another relative lull overnight where VFR conditions are expected to prevail. More convection possible again Wednesday morning. Confidence is low beyond this evening. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........BJS Short Term.....13 Long Term......ZT Aviation.......BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1150 AM EDT Tue Apr 7 2015 ...Forecast Update... Issued at 1149 AM EDT Tue Apr 7 2015 The complex of showers and thunderstorms will continue to push east along the I-64 corridor for the next hour or two. They are looking less organized but will still be capable of frequent cloud to ground lightning and brief heavy rainfall. Focus is now shifting to the west where the previous supercell has now evolved into a growing linear segment crossing the Mississippi River near St. Louis. This feature is expected to continue ESE or SE toward our region through the early afternoon, growing as it does so. Already seeing good destabilization across west central KY where some clearing has occurred, and do expect a 1500 - 2500 J/KG instability axis to setup along and west of I-65 during peak heating. Some of the southern Indiana counties where this morning`s complex passed may struggle to get as unstable. Will also note that 0-6 km bulk shear should range between 30-40 knots, sufficient for continued organization. Forecast sounding are quite impressive if they verify and would suggest a severe wind and hail threat with the strongest storms. In collaboration with the Storm Prediction Center, mention of an upgrade to a slight risk is a possibility across western portions of our CWA this afternoon. Right now the best timing for the CWA looks to be between 3 PM EDT and 9 PM EDT. Do want to mention that another round of heavy rain will accompany the potential severe threat with this next round of convection. Depending on where heaviest rain falls, more hydro products may be needed. Previous Update... Issued at 919 AM EDT Tue Apr 7 2015 Storms will wind down along the I-64 corridor through the late morning hours. However, will have to keep an eye on the stronger cluster currently over southern Indiana as it moves ESE toward the Kentucky Bluegrass region. Very intense rainfall has left 2 to 3 inches in a short amount of time across small portions of southern Indiana and will keep the Flash Flood Warning going across Orange/Washington counties for the time being. Have upped pops and QPF to account for this cluster. Hail will also be possible with this storm. Focus will then shift to this afternoon and evening as another round of storms will be possible. Looking upstream, an impressive supercell is tracking ESE along I-70 and the warm front toward St. Louis. This feature is expected to turn more SE along the instability gradient through the late morning and early afternoon, and grow into a more linear complex. Do expect to get some partial clearing which will aid an already destabilizing atmosphere. SREF probabilities of greater than 1000 J/KG of CAPE this afternoon are likely along and west of I-65. 0-6 km shear values between 30 and 40 knots this afternoon would also support organization. Will have to watch how things progress through the late morning as there is some concern for strong to severe storms this afternoon and evening. The 06z NAM and HRRR are handling the current situation pretty well. However the NAM is a bit too far north and a couple hours slow. Did the afternoon forecast based off this solution with adjustments for timing placement. Adjusted QPF upward as well in anticipation of the afternoon storms. .SHORT TERM (Now through Wednesday)... Issued at 257 AM EDT Tue Apr 7 2015 The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good handle on an area of showers and embedded thunderstorms moving from southeast Illinois into the lower and middle Ohio Valley at 07Z this morning. The storms are ahead of an upper level disturbance coming in from the lower and middle Mississippi Valley. This convective complex will continue to spread eastward this morning along and a few counties either side of the I-64 corridor. Though the showers and storms will mostly be garden variety, a few gusts of wind or instances of small hail in the strongest cores can`t be entirely ruled out. The morning showers and storms will have moved off to the east by early afternoon. This afternoon another weak upper wave will come in from the west. Though some stabilization will occur over southern Indiana and northern Kentucky from the morning rain, additional scattered shower and thunderstorm development will be possible, albeit with less coverage than what we see this morning. Again, a few strong storms will be possible. With plenty of moisture available, locally heavy downpours will be possible with the thunderstorms. The cells should be progressive, but there will be some training this morning in southern Indiana and north central Kentucky. Decided to drop max temps a few degrees in the north where more rain and clouds will prevail through the morning hours, but still have 70s everywhere for highs this afternoon. After a lull this evening, more shower and thunderstorm development will be possible late tonight as the next weak upper wave comes in from the west after midnight. Low temperatures will be in the lower and middle 60s. The relatively low confidence forecast today and tonight becomes even lower on Wednesday. We will remain in the same warm, juicy air mass as today, south of a stationary surface front from Illinois to Ohio. The late night showers/storms tonight will likely persist into Wednesday morning, with redevelopment possible Wednesday afternoon especially near any leftover convective boundaries from the morning activity. Highs should be in the middle and upper 70s...maybe an 80 degree reading if we can get enough sunshine in the afternoon. .LONG TERM (Wednesday Night through Monday)... Issued at 235 AM EDT Tue Apr 7 2015 The focus in the long term period is on thunderstorm chances/timing Wednesday night through Friday. The upper level pattern Wednesday night is expected to feature a digging trough from the Rockies into the central Plains with downstream ridging extending from the Gulf Coast through the southern Great Lakes region. At the surface, a warm and moist air mass characterized by dewpoints in the 60s will be in place thanks to a developing surface low to our west. Stronger southerly flow should make for a mild night with lows only falling into the mid 60s. The focus for thunderstorm initiation Wednesday night is favored to our west where the strengthening low-level jet impinges on an east-west boundary across Illinois. These storms could then take an east/southeast track across portions of the area. Strength/severity a bit more uncertain as elevated instability wanes considerably and effective shear is not as impressive but a few elevated stronger storms would be possible. Kept POPs in the 30-50 percent range, tapered highest to lowest from southern Indiana to southern Kentucky respectively. The main upper level trough will advance eastward Thursday as the surface low deepens/lifts to Wisconsin by Thursday night. 07.00z guidance remained overall similar to earlier runs in its progression, bringing the cold front through the local area late Thursday night into Friday morning. Scattered showers and thunderstorms are possible ahead of the main system though coverage isn`t expected to be very high. Decaying strong thunderstorms look to be approaching our western borders during the late evening, and if enough elevated instability remains present, a marginal wind threat exists. Overall, the system looks fairly progressive, limiting the training heavy rainfall threat as well. Ahead of the front, a very warm air mass will be in place. Depending on how cloud cover fares, we`ll be approaching 80 degrees in most spots Thursday. A mild night would then set up with lows in the mid 60s to near 70 degrees. Friday looks to be our transition day as the front sweeps across the area. Will keep chance POPs in the morning to early afternoon hours, especially east of I-65 before clearing conditions work in for the evening. Seasonable, pleasant and mostly sunny conditions thanks to surface high pressure expected Saturday into the first part of Sunday. A model consensus approach gives highs in the mid to upper 60s Saturday and upper 60s to low 70s Sunday. Increasing moisture and southerly return flow sets up Sunday night into early next week as the surface high moves to our east. A slow ramp up in POPs, still chance, will be advertised as deterministic models show another system lifting through the central Plains to lower Great Lakes. Seasonable to above seasonable temperatures look reasonable at this time. && .AVIATION (12Z TAF Update)... Updated at 636 AM EDT Tue Apr 7 2015 Showers should be common through the morning hours, especially at LEX and SDF, with some embedded thunder as well. Ceilings will be highly variable, but should prevail MVFR below fuel mins. Expect drier conditions this afternoon and tonight (though scattered showers and storms will still be possible). Ceilings should gradually improve today as the wave that is sparking this morning`s convection moves off to the east. BWG could see a few wind gusts into the teens this afternoon outside of convection. Another wave of convection may come in from the northwest late tonight into Wednesday morning, though forecast confidence is not high that far out in this weather regime. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........BJS Short Term.....13 Long Term......ZT Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
1135 AM EDT TUE APR 7 2015 .UPDATE... ISSUED AT 1135 AM EDT TUE APR 7 2015 THUNDERSTORM COMPLEX WHICH RESULTED IN A FEW FLOODING REPORTS IN OUR SOUTHERN COUNTIES IS EXITING IN TN AND VA. OTHER THUNDERSTORMS IN THE LMK AREA WERE HEADING TOWARD OUR NORTHERN COUNTIES...BUT WERE WEAKENING. HAVE ADJUSTED NEAR TERM POPS FOR THE OBSERVED RADAR TRENDS. WITH A MOIST AIR MASS...WARM AIR ADVECTION...A FRONTAL BOUNDARY JUST TO OUR NORTH...NO SIGNIFICANT CAP...AND WEAK IMPULSES PASSING THROUGH...REDEVELOPMENT/INTENSIFICATION WILL BE A POSSIBILITY AS SOME LIMITED DESTABILIZATION OCCURS THIS AFTERNOON. CONFIDENCE IN TIMING AND LOCATION IS LOW. HAVE LEANED TOWARD THE HRRR SOLUTION THIS AFTERNOON INTO TONIGHT...BUT KEPT THE FORECAST FAIRLY GENERALIZED. UPDATE ISSUED AT 800 AM EDT TUE APR 7 2015 DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 340 AM EDT TUE APR 7 2015 06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY. THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT... MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60 DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER CONDITIONS IN THE FAR SOUTHWEST. DEW POINTS...MEANWHILE...HAVE COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS PAST WEEKEND/S DRYNESS. THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS. SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO. USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 AM EDT TUE APR 7 2015 MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS THE OHIO RIVER VALLEY DURING THIS TIME. AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA. THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN 21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY AFTERNOON. EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 815 AM EDT TUE APR 7 2015 THE SHOWERS AND STORMS MOVED INTO THE AREA ON TRACK WITH THE EARLIER FORECAST WITH MVFR TO IFR CIGS. THESE WILL BE THE RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD EVEN ONCE THIS INITIAL PASSES THROUGH BY MID MORNING. ANOTHER IMPULSE IS EXPECTED THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT FOR HIGHER GUSTS IN STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
920 AM EDT Tue Apr 7 2015 ...Forecast Update... Issued at 919 AM EDT Tue Apr 7 2015 Storms will wind down along the I-64 corridor through the late morning hours. However, will have to keep an eye on the stronger cluster currently over southern Indiana as it moves ESE toward the Kentucky Bluegrass region. Very intense rainfall has left 2 to 3 inches in a short amount of time across small portions of southern Indiana and will keep the Flash Flood Warning going across Orange/Washington counties for the time being. Have upped pops and QPF to account for this cluster. Hail will also be possible with this storm. Focus will then shift to this afternoon and evening as another round of storms will be possible. Looking upstream, an impressive supercell is tracking ESE along I-70 and the warm front toward St. Louis. This feature is expected to turn more SE along the instability gradient through the late morning and early afternoon, and grow into a more linear complex. Do expect to get some partial clearing which will aid an already destabilizing atmosphere. SREF probabilities of greater than 1000 J/KG of CAPE this afternoon are likely along and west of I-65. 0-6 km shear values between 30 and 40 knots this afternoon would also support organization. Will have to watch how things progress through the late morning as there is some concern for strong to severe storms this afternoon and evening. The 06z NAM and HRRR are handling the current situation pretty well. However the NAM is a bit too far north and a couple hours slow. Did the afternoon forecast based off this solution with adjustments for timing placement. Adjusted QPF upward as well in anticipation of the afternoon storms. .SHORT TERM (Now through Wednesday)... Issued at 257 AM EDT Tue Apr 7 2015 The GFS, 4km NAM, and, to a lesser extent, SPC SREF, have a good handle on an area of showers and embedded thunderstorms moving from southeast Illinois into the lower and middle Ohio Valley at 07Z this morning. The storms are ahead of an upper level disturbance coming in from the lower and middle Mississippi Valley. This convective complex will continue to spread eastward this morning along and a few counties either side of the I-64 corridor. Though the showers and storms will mostly be garden variety, a few gusts of wind or instances of small hail in the strongest cores can`t be entirely ruled out. The morning showers and storms will have moved off to the east by early afternoon. This afternoon another weak upper wave will come in from the west. Though some stabilization will occur over southern Indiana and northern Kentucky from the morning rain, additional scattered shower and thunderstorm development will be possible, albeit with less coverage than what we see this morning. Again, a few strong storms will be possible. With plenty of moisture available, locally heavy downpours will be possible with the thunderstorms. The cells should be progressive, but there will be some training this morning in southern Indiana and north central Kentucky. Decided to drop max temps a few degrees in the north where more rain and clouds will prevail through the morning hours, but still have 70s everywhere for highs this afternoon. After a lull this evening, more shower and thunderstorm development will be possible late tonight as the next weak upper wave comes in from the west after midnight. Low temperatures will be in the lower and middle 60s. The relatively low confidence forecast today and tonight becomes even lower on Wednesday. We will remain in the same warm, juicy air mass as today, south of a stationary surface front from Illinois to Ohio. The late night showers/storms tonight will likely persist into Wednesday morning, with redevelopment possible Wednesday afternoon especially near any leftover convective boundaries from the morning activity. Highs should be in the middle and upper 70s...maybe an 80 degree reading if we can get enough sunshine in the afternoon. .LONG TERM (Wednesday Night through Monday)... Issued at 235 AM EDT Tue Apr 7 2015 The focus in the long term period is on thunderstorm chances/timing Wednesday night through Friday. The upper level pattern Wednesday night is expected to feature a digging trough from the Rockies into the central Plains with downstream ridging extending from the Gulf Coast through the southern Great Lakes region. At the surface, a warm and moist air mass characterized by dewpoints in the 60s will be in place thanks to a developing surface low to our west. Stronger southerly flow should make for a mild night with lows only falling into the mid 60s. The focus for thunderstorm initiation Wednesday night is favored to our west where the strengthening low-level jet impinges on an east-west boundary across Illinois. These storms could then take an east/southeast track across portions of the area. Strength/severity a bit more uncertain as elevated instability wanes considerably and effective shear is not as impressive but a few elevated stronger storms would be possible. Kept POPs in the 30-50 percent range, tapered highest to lowest from southern Indiana to southern Kentucky respectively. The main upper level trough will advance eastward Thursday as the surface low deepens/lifts to Wisconsin by Thursday night. 07.00z guidance remained overall similar to earlier runs in its progression, bringing the cold front through the local area late Thursday night into Friday morning. Scattered showers and thunderstorms are possible ahead of the main system though coverage isn`t expected to be very high. Decaying strong thunderstorms look to be approaching our western borders during the late evening, and if enough elevated instability remains present, a marginal wind threat exists. Overall, the system looks fairly progressive, limiting the training heavy rainfall threat as well. Ahead of the front, a very warm air mass will be in place. Depending on how cloud cover fares, we`ll be approaching 80 degrees in most spots Thursday. A mild night would then set up with lows in the mid 60s to near 70 degrees. Friday looks to be our transition day as the front sweeps across the area. Will keep chance POPs in the morning to early afternoon hours, especially east of I-65 before clearing conditions work in for the evening. Seasonable, pleasant and mostly sunny conditions thanks to surface high pressure expected Saturday into the first part of Sunday. A model consensus approach gives highs in the mid to upper 60s Saturday and upper 60s to low 70s Sunday. Increasing moisture and southerly return flow sets up Sunday night into early next week as the surface high moves to our east. A slow ramp up in POPs, still chance, will be advertised as deterministic models show another system lifting through the central Plains to lower Great Lakes. Seasonable to above seasonable temperatures look reasonable at this time. && .AVIATION (12Z TAF Update)... Updated at 636 AM EDT Tue Apr 7 2015 Showers should be common through the morning hours, especially at LEX and SDF, with some embedded thunder as well. Ceilings will be highly variable, but should prevail MVFR below fuel mins. Expect drier conditions this afternoon and tonight (though scattered showers and storms will still be possible). Ceilings should gradually improve today as the wave that is sparking this morning`s convection moves off to the east. BWG could see a few wind gusts into the teens this afternoon outside of convection. Another wave of convection may come in from the northwest late tonight into Wednesday morning, though forecast confidence is not high that far out in this weather regime. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........BJS Short Term.....13 Long Term......ZT Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
815 AM EDT TUE APR 7 2015 .UPDATE... ISSUED AT 800 AM EDT TUE APR 7 2015 DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS WITH THE SWATH OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING THROUGH THE CWA. ALSO FINE TUNED THE TEMPS AND TD FOR THE LATEST OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 340 AM EDT TUE APR 7 2015 06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY. THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT... MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60 DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER CONDITIONS IN THE FAR SOUTHWEST. DEWPOINTS...MEANWHILE...HAVE COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS PAST WEEKEND/S DRYNESS. THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS. SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO. USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 AM EDT TUE APR 7 2015 MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS THE OHIO RIVER VALLEY DURING THIS TIME. AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA. THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN 21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY AFTERNOON. EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 815 AM EDT TUE APR 7 2015 THE SHOWERS AND STORMS MOVED INTO THE AREA ON TRACK WITH THE EARLIER FORECAST WITH MVFR TO IFR CIGS. THESE WILL BE THE RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD EVEN ONCE THIS INITIAL PASSES THROUGH BY MID MORNING. ANOTHER IMPULSE IS EXPECTED THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT FOR HIGHER GUSTS IN STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 AM EDT TUE APR 7 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 340 AM EDT TUE APR 7 2015 06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE CENTRAL PLAINS WITH A WARM FRONT SLUNG EAST...RUNNING INTO THE OHIO VALLEY BEFORE BECOMING A STATIONARY BOUNDARY JUST NORTH OF EASTERN KENTUCKY. THIS PLACES THE CWA IN A WARM AND MOIST ENVIRONMENT AS SOUTH WINDS SUPPORT PWS APPROACHING 1.5 INCHES. JUST NOW A FEW SHOWERS ARE STARTING TO POP OVER THE SOUTHERN PARTS OF THE AREA AFTER A RELATIVELY QUIET EVENING AND START TO THE NIGHT. ADDITIONAL CONVECTION TO THE WEST IS PUSHING EAST JUST SOUTH OF THE WARM FRONT...CURRENTLY MOVING THROUGH NORTHWESTERN KENTUCKY AND SOUTHERN ILLINOIS/INDIANA. UNDER MOSTLY CLOUDY SKIES OVERNIGHT... MOST OF EASTERN KENTUCKY IS SEEING TEMPERATURES FROM 55 TO 60 DEGREES WITH SOME EASTERN VALLEYS SLIGHTLY COOLER AND WARMER CONDITIONS IN THE FAR SOUTHWEST. DEWPOINTS...MEANWHILE...HAVE COME UP INTO THE 50S FOR THE AREA...A DRAMATIC REVERSAL OF THIS PAST WEEKEND/S DRYNESS. THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS A SERIES OF WEAK TO MODERATE WAVES PASS THROUGH THE OHIO VALLEY IN BROAD...SLIGHTLY SOUTHWEST...FLOW ON THE NORTHERN FRINGE OF THE FLAT SOUTHEAST RIDGE. EACH MODEL HAS A SLIGHTLY DIFFERENT HANDLE ON THE TIMING AND TRACK OF THESE WAVES LOWERING CONFIDENCE IN ANY PARTICULAR SOLUTION. NEVERTHELESS...THE ENERGY WILL BE THERE...ALONG WITH PLENTY OF FUEL IN THE FORM OF HEAT AND HUMIDITY...FOR CONVECTIVE DEVELOPMENT BASED MORE ON THESE MID LEVEL RIPPLES THAN STRICTLY THE DIURNAL CYCLE. GIVEN THE SMALL NATURE OF THE FEATURES THAT WILL DRIVE THE CONVECTION OVER THE NEXT COUPLE OF DAYS HAVE RELIED MORE CLOSELY ON THE HIGHER RESOLUTION HRRR AND NAM12 FOR THE WEATHER DETAILS. SENSIBLE WEATHER WILL FEATURE AN UNSEASONABLY WARM AND HUMID PERIOD WITH OCCASIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED DUE TO EASTERN KENTUCKY/S POSITION SOUTH OF A STALLED FRONTAL BOUNDARY TO THE NORTH AND IMPULSES PASSING THROUGH FROM ALOFT. THE FIRST OF THESE WILL PASS THIS MORNING WITH A ROUND OF CONVECTION EXPECTED FOLLOWED BY A POTENTIAL FOR ANOTHER LATE THIS AFTERNOON AND INTO THE EVENING. THE NAM12 WOULD THEN HAVE A LULL UNTIL DAYTIME WEDNESDAY WHEN ANOTHER WAVE IS EXPECTED TO DEVELOP AND PASS OVER THE STATE. SEVERE WEATHER WILL BE A POSSIBILITY TODAY WITH EITHER OF THESE CLUSTERS DEPENDING ON UPSCALE GROWTH AND...FOR THE LATTER...SFC HEATING BETWEEN SYSTEMS. GIVEN THE RELATIVELY HIGH PWS...HEAVY RAIN WILL BE A POSSIBILITY AS WELL AND MAY PRIME THE AREA FOR LOCALIZED FLOOD CONCERNS BEFORE THE FRONTAL STRUCTURE MOVES OUT OF THE REGION AT WEEK/S END. WILL HIGHLIGHT BOTH THE SVR AND HEAVY RAIN CONCERNS IN THE FORTHCOMING HWO. USED THE SHORTBLEND COMPOSITE MODEL AS A STARTING POINT FOR THE WINDS/T/TD GRIDS THROUGH THE FIRST 18-24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS BASED ON TERRAIN FOR TONIGHT/S TEMPERATURES. AS FOR POPS...ENDED UP CLOSEST TO THE MET VALUES TODAY AND TONIGHT...BUT HIGHER FOR MIDDAY WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 AM EDT TUE APR 7 2015 MULTIPLE WAVES WILL CONTINUE TO RIDE UP AND ALONG A RIDGING PATTERN ACROSS THE EASTERN CONUS THROUGH THE SHORT TERM AND TO START OUT THE EXTENDED PORTION OF THE FORECAST. MEANWHILE A STRONG SHORTWAVE OVER THE ROCKIES WILL BEGIN TO SHIFT EASTWARD BY 0Z THURSDAY...CREATING LONGWAVE TROUGHING OVER THE WESTERN CONUS. EXPECT THIS SHORTWAVE TO CONTINUE ON ITS TREK EAST AND NORTHEASTWARD THROUGH THE DAY THURSDAY AND INTO THE DAY FRIDAY...WITH DECREASING HEIGHTS EXPECTED ACROSS THE OHIO RIVER VALLEY DURING THIS TIME. AT THE SURFACE...KY WILL FIND ITSELF UNDER THE INFLUENCE OF A STALLED WARM FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING...WHICH WILL LIKELY BE POSITIONED ACROSS THE NORTHERN PORTION OF THE CWA. THIS WILL RESULT IN CONTINUED SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE STATE. TO OUR EAST...A SURFACE LOW WILL CONTINUE TO DEVELOP BELOW AND JUST AHEAD OF THE ABOVE MENTIONED SHORTWAVE...AND FOLLOW ITS TRACK NORTHEASTWARD THROUGH THE DAY THURSDAY. BY 0Z FRIDAY...THE WARM FRONT WILL SHIFT EAST AND ENABLE A STRONG COLD FRONT...CONNECTED TO THIS LOW PRESSURE SYSTEM...TO PUSH FROM WEST TO EAST ACROSS KY. GIVEN THE LATEST GFS FORECAST...THE BOUNDARY SHOULD ENTER INTO EASTERN KY SOMETIME FRIDAY AFTERNOON...ENHANCING SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE MORNING JUST AHEAD OF THE FRONT...AND EXIT EAST OF THE STATE BETWEEN 21Z FRIDAY AND 0Z SATURDAY. ONCE IT DOES...KY WILL BE IN A MORE ZONAL UPPER LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING ACROSS THE STATE. SURFACE WINDS WILL ONCE AGAIN BECOME MORE NORTHERLY...CAUSING TEMPERATURES TO DROP BACK INTO THE 40S OVERNIGHT FRIDAY NIGHT/SATURDAY MORNING...AND IN THE MID 60S BY SATURDAY AFTERNOON. EXPECT THIS HIGH PRESSURE TO KEEP DRY WEATHER IN PLAY THROUGH MUCH OF THE WEEKEND...WITH TEMPERATURES EXPECTED TO REBOUND BACK INTO THE LOW 70S BY MONDAY. BY THIS TIME...A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS WILL MOVE NE ONCE MORE AND PUSH A WARM FRONT NORTHWARD INTO THE REGION...ALLOWING UNSTABLE WARM GULF MOISTURE TO FLOW BACK INTO THE CWA AND ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP LATE SUNDAY AND SUNDAY NIGHT. THIS WILL BE ENHANCED AS THE FOLLOWING COLD FRONT BEGINS FROM WEST TO EAST ACROSS THE STATE ONCE MORE DURING THE DAY MONDAY AND MONDAY NIGHT. EXACT TIMING OF THIS FRONTAL PASSAGE...AS WELL AS THE ONSET AND STRENGTH OF THE PRECIPITATION ARE STILL FAR ENOUGH OUT IN THE FORECAST THAT RELYING ON A MODEL BLEND WAS THE METHOD OF CHOICE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 210 AM EDT TUE APR 7 2015 THE LATEST HRRR AND NAM12 HOLD OFF ON ANY SIGNIFICANT PCPN MOVING INTO EAST KENTUCKY UNTIL CLOSER TO 12Z. THIS LINES UP WELL WITH A CLUSTER OF SHOWERS AND THUNDERSTORMS NOW MOVING THROUGH SOUTHERN ILLINOIS...INDIANA AND NORTHWEST KENTUCKY. MVFR CIGS WILL BE THE RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD AS THIS INITIAL WAVE APPROACHES AND PASSES THROUGH THIS MORNING FOLLOWED BY ANOTHER POSSIBLE IMPULSE LATER THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT IN HIGHER GUSTS IN STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JMW AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
209 AM EDT TUE APR 7 2015 .UPDATE... ISSUED AT 145 AM EDT TUE APR 7 2015 DID A QUICK UPDATE TO THE GRIDS MAINLY TO SLOW DOWN THE ARRIVAL OF ANY SIGNIFICANT PCPN UNTIL CLOSER TOWARD DAWN. ALSO UPDATED THE SKY COVER AND T/TD GRIDS PER THE LATEST SHORTBLEND GUIDANCE... OBS...AND TRENDS. THESE HAVE BEEN SENT TO THE THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 1051 PM EDT MON APR 6 2015 THE AREA OF SHOWERS THAT AFFECTED SOUTHERN PORTIONS OF THE CWA HAVE MOVED EAST OF THE REGION THIS HOUR. WSR-88D RADAR SHOWS A AREA OF SHOWERS ACROSS CENTRAL KY MOVING SOUTH AND EAST...HOWEVER THIS AREA OF SHOWERS HAS CONTINUED TO WANE OVER THE PAST FEW HOURS. GIVEN THIS FELT IT JUSTIFIED DROPPING POPS FOR PORTIONS OF THE NIGHT. ALL EYES THEN TURN TO THE WEST...WHILE A SUBTLE UPPER LEVEL WAVE MOVES THROUGH THE FLOW AS WE MOVE THROUGH THE NIGHT INTO EARLY TOMORROW. WHILE IT SHOULD BE SAID THAT THE GUIDANCE CONTINUES TO STRUGGLE TONIGHT...THE HRRR HAS COME BACK TO PROGRESSING AN AREA OF PRECIP ALONG THE WESTERN CWA BORDER TOWARD THE DAWN HOURS TUESDAY. DID STICK CLOSE TO PREVIOUS FORECAST FOR THAT PERIOD...GIVEN CONTINUED UNCERTAINTY ON NEXT AREA OF PRECIP AND STILL LOOKED REASONABLE BASED ON LATEST MESO MODEL GUIDANCE. ALSO UPDATED GRIDS TO MATCH LATEST OBS AND TRENDS. UPDATE ISSUED AT 832 PM EDT MON APR 6 2015 WSR-88D CONTINUES TO SHOW AN AREA OF SHOWERS MOVING EAST ACROSS SOUTHEAST PORTIONS OF THE CWA THIS EVENING. HEAVIER SHOWERS HAVE GENERALLY BEEN ALONG AND NEAR THE TN/VA BORDER THIS AFTERNOON AND EVENING. OTHERWISE MOST AREAS ARE CONTINUING TO SEE A PASSING LIGHT SHOWER FROM TIME TO TIME. EVEN THOUGH MUCH OF THIS HAS BEEN SHOWERS HAVE KEPT THE MENTION OF THUNDER GIVEN THAT WE CONTINUE TO BE IN A GENERALLY MOIST AND UNSTABLE ENVIRONMENT. THERE CONTINUES TO BE A FAIR AMOUNT OF UNCERTAINTY WHERE AND WHEN THE BETTER SHOWERS AND THUNDERSTORMS SETUP ACROSS THE REGION OVER THE NEXT 24 HOURS. THIS DISAGREEMENT IS ALSO PREVALENT IN MUCH OF THE MESO MODEL GUIDANCE AS WELL. EITHER WAY THE NEXT BEST WAVE LOOKS TO MOVE THROUGH...AS WE MOVE INTO TUESDAY MORNING. GIVEN THIS THE CURRENT POP GRIDS LOOK DECENT. DID UPDATE GRIDS WITH LATEST OBS AND TRENDS...OTHERWISE GIVEN UNCERTAINTY NO MAJOR CHANGES PLANNED THIS UPDATE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 405 PM EDT MON APR 6 2015 THE REGION WAS IN A SOMEWHAT ZONAL PATTERN WITH WEST TO WEST SOUTHWESTERLY FLOW ALOFT BETWEEN A TROUGH OVER EASTERN CANADA AND THE NORTHERN GREAT LAKES AND A RIDGE CENTERED OVER THE GULF OF MEXICO. FURTHER WEST...A TROUGH WAS GRADUALLY WORKING ONSHORE OF THE WEST COAST OF THE CONUS. A SHORTWAVE TROUGH WORKING FROM THE NORTHERN GREAT LAKES INTO THE NORTHEASTERN CONUS WILL PUSH A COLD FRONT SOUTH FROM THE GREAT LAKES REGION DOWN TO NEAR THE I 70 CORRIDOR OR SLIGHT SOUTH OF THAT...BUT REMAIN NORTH OF THE OH RIVER. THEN...AS THE TROUGH WORKS FURTHER INTO THE WESTERN CONUS...THIS BOUNDARY WILL RETREAT NORTH LATE IN THE SHORT TERM PERIOD WITH AND AN OLD BOUNDARY CURRENTLY EXTENDING FROM THE CENTRAL PLAINS INTO THE DEEP SOUTH ALSO BECOMING MORE ILL DEFINED AND RETREATING NORTH...POSSIBLY NORTH OF THE OH RIVER LATE. THIS WILL OCCUR AS HEIGHTS RISE ACROSS THE SOUTHEASTERN CONUS. AN AREA OF SHOWERS AND VERY FEW EMBEDDED THUNDERSTORMS AT PRESENT IS APPROACHING OF EASTERN KENTUCKY FROM CENTRAL AND WESTERN KY AND MIDDLE TN ASSOCIATED WITH ISENTROPIC LIFT OVER THE BOUNDARY TO OUR SOUTHWEST AND WEST. RAINFALL OF NEARLY A HALF OF AN INCH HAS OCCURRED AT KBNA. THE GENERAL MODEL CONSENSUS IS FOR THIS ACTIVITY TO BE MOST WIDESPREAD ACROSS THE SOUTHERN CWA DURING THIS EVENING...ALTHOUGH ISOLATED TO SCATTERED ACTIVITY IS POSSIBLE ACROSS THE NORTH. NOT MUCH IN THE WAY OF THUNDER IS EXPECTED WITH THIS AS THE ATMOSPHERE CONTINUES TO MOISTEN. HOWEVER...SOME LOCALLY HIGHER RAINFALL IS POSSIBLE IN ANY HEAVIER SHOWERS OR ANY THUNDERSTORMS. AFTER THAT...MCS ACTIVITY SHOULD BEGIN TO DEVELOP SOUTH OF THE FRONT TO OUR NORTH AND POSSIBLY NEARER TO THE BOUNDARY TO THE SOUTHWEST OF THE AREA. CONFIDENCE IN THE DETAILS AND EVOLUTION OF THIS IS NOT HIGH...WITH DIFFERENCES FROM MODEL RUN TO MODEL RUN. HOWEVER... PRECIP CHANCES APPEAR BEST THIS EVENING...WITH SOMEWHAT OF A LULL TOWARD MIDNIGHT INTO THE OVERNIGHT HOURS. TOWARD DAWN AND INTO TUESDAY MORNING APPEARS TO BE THE NEXT PERIOD WITH THE HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS. THE NORTHERN PART OF THE AREA COULD EXPERIENCE THE MORE PERSISTENT ACTIVITY OR AT LEAST QPF FROM THIS AS THEY WILL BE CLOSER TO THE BOUNDARY. THE MODEL CONSENSUS IS FOR A SHORTWAVE TROUGH TO MOVE THROUGH THE REGION TOMORROW AFTERNOON INTO TOMORROW EVENING...WITH HEIGHTS THEN RISING ACROSS THE SOUTHEASTERN CONUS. WITH THE LOSS OF DAYTIME HEATING AND THE BOUNDARY RETREATING NORTH...CHANCES FOR SHOWERS AND THUNDERSTORMS APPEAR AS IF THEY WOULD DECREASE FOR A WHILE FROM MID TO LATE EVENING INTO THE OVERNIGHT HOURS. HOWEVER... ADDITIONAL WEAK WAVES IN THE FLOW MAY LEAD TO NOCTURNAL DEVELOPMENT IN THE WARM AND MOIST AIRMASS IN PLACE ACROSS THE OH VALLEY AND MS VALLEY REGION LATE IN THE PERIOD. WITH A MUCH MORE MOIST AIRMASS IN PLACE AND RATHER PERSISTENT CLOUD COVER EXPECTED FOR MUCH OF THE PERIOD...DIURNAL RANGES WILL BE MORE LIMITED THAN RECENT DAYS. PARTIAL CLEARING COULD BRING SMALL RIDGE/VALLEY SPLITS TONIGHT AND OR TUESDAY NIGHT IF AND WHERE IT OCCURS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 405 PM EDT MON APR 6 2015 THE EXTENDED PERIOD LOOKS TO BE QUITE ACTIVE WITH MULTIPLE IMPULSES RIDING OVER A BROAD RIDGE SET UP ACROSS THE EASTERN CONUS...AND A WARM FRONT STALLED OUT NORTH OF THE REGION. THE IMPULSES MOVING OVER THE RIDGE AND ALONG THE BOUNDARY WILL BRING RAIN AND THUNDERSTORM CHANCES THROUGH THE END OF THE WORK WEEK. THE RISK OF ORGANIZED AND MORE THREATENING STORMS DEVELOPS LATER THURSDAY AND CONTINUES THROUGH FRIDAY DUE TO THE APPROACHING SFC LOW AND TROF. THE SFC LOW THEN LIFTS TOWARDS THE GREAT LAKES REGION ON FRIDAY WITH A SLOW MOVING COLD FRONT PASSING THROUGH THE AREA FRIDAY EVENING. THERE ARE SOME DIFFERENCES BETWEEN THE MODELS ON THE TIMING OF THE FRONTAL PASSAGE SO HAVE WENT WITH A COMPROMISE BETWEEN GFS/ECMWF. ADDITIONALLY... THERE WILL BE AMPLE MOISTURE FOR THE STORMS TO TAP INTO...WITH PW VALUES EXCEEDING 1.25" OR ABOVE 2 STANDARD DEVIATIONS ABOVE NORMAL. THEREFORE...MODERATE TO HEAVY RAINFALL WILL BE A THREAT FOR THE END OF THE WEEK. DRIER WEATHER RETURNS FOR THE WEEKEND AS A SFC RIDGE BUILDS IN OVER THE OHIO VALLEY. THIS WILL ALSO BRING MORE SEASONABLE TEMPERATURES TO THE STATE FOLLOWING A WEEK OF WELL ABOVE NORMAL TEMPERATURES....WHERE SOME LOW 80S COULD BE SEEN...DESPITE THE CLOUDINESS AND PERIODS OF RAIN. THE BEGINNING OF NEXT WEEK BRINGS MORE CHANCES FOR RAIN AS ANOTHER TROF AND SURFACE LOW MOVES TOWARDS OUR AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 210 AM EDT TUE APR 7 2015 THE LATEST HRRR AND NAM12 HOLD OFF ON ANY SIGNIFICANT PCPN MOVING INTO EAST KENTUCKY UNTIL CLOSER TO 12Z. THIS LINES UP WELL WITH A CLUSTER OF SHOWERS AND THUNDERSTORMS NOW MOVING THROUGH SOUTHERN ILLINOIS...INDIANA AND NORTHWEST KENTUCKY. MVFR CIGS WILL BE THE RULE FOR MOST OF THE AREA THROUGH THE TAF PERIOD AS THIS INITIAL WAVE APPROACHES AND PASSES THROUGH THIS MORNING FOLLOWED BY ANOTHER POSSIBLE IMPULSE LATER THIS EVENING WITH ADDITIONAL LOW CIGS AND SHOWERS/STORMS. IN THE HEAVIER CONVECTION...MVFR VIS WILL BE A GOOD BET WITH OCCASIONAL IFR VIS OR CIGS IN STORMS. THROUGH THE TAF PERIOD...WINDS WILL GENERALLY BE FROM THE SOUTH AT 5 TO 10 KTS...EXCEPT IN HIGHER GUSTS IN STORMS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JP LONG TERM...JVM/GREIF AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1009 PM EDT WED APR 8 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN OVERNIGHT...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THURSDAY INTO THURSDAY NIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WHAT`S LEFT OF A DECAYING OH VLY MCS WAS MOVING THROUGH NE NC AS OF 10 PM. THIS BATCH OF SHOWERS AND SUB-SEVERE THUNDERSTORMS WILL MOVE OUT OF THE AREA BETWEEN MIDNIGHT-1AM. OTW...A BACKDOOR COLD FRONT SITS JUST SOUTH OF THE FA AND SHOULD REMAIN STATIONARY OVERNIGHT. THIS WILL ALLOW LOW OVERCAST CONDITIONS TO CONTINUE OVERNIGHT WITH SFC HIGH PRESSURE RIDGING DOWN INTO THE LOCAL AREA FROM THE NORTHEAST. THE NEXT BATCH OF PCPN IS MAKING ITS WAY THROUGH THE OH VLY LATE THIS EVENING AND IS SHOWN BY THE LATEST HRRR TO MAKE A RUN AT THE FA BY AROUND 08-09Z...THEN MOVING SE THRU 15Z. THE HRRR DID A GOOD JOB HANDLING THE MCS THIS EVENING SO WILL LEAN TOWARD ITS SOLUTION OVERNIGHT AND HAVE ADJUSTED POPS ACCORDINGLY. LOWS TONIGHT FROM NR 40 MD EASTERN SHORE TO THE LOW/MID 50S SW. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THE FRONT WILL WEAKEN...WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY LATE THU. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO M70S WITH MORE TIME IN THE WARM SECTOR ACROSS SRN/WRN AREAS. POPS REMAIN IN THE CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN PERIODS FOR SCT SHRAS...AND ISOLTD TSTMS ESPECIALLY OVER SRN/WRN AREAS. THE SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS...HAIL AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY COMPARED TO PREVIOUS DAYS AS THE ENTIRE FA RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS SE AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... THE COLD FRONT THAT MOVD THROUGH THE AREA HAS PUSHED INTO NC AND AN AREA OF CONVECTION IS MOVING THROUGH THE CWA EARLY THIS EVENING. THE PRECIP WILL HAVE LITTLE TO NO AFFECT ON TAF SITES WITH ONLY A BRIEF TSTM PSBL IN RIC AND A CHANCE FOR A FEW SHOWERS IN ORF AND PHF. WIDESPREAD STRATUS CONTINUES TO AFFECT THE REGION WITH MVFR/IFR CONDS AND THIS IS EXPECTED TO CONTINUE THROUGH THE OVERNIGHT WITH CIGS AND VSBY LOWERING TO LIFR AT ALL SITES. SOME -RA IS POSSIBLE OVERNIGHT...BUT THERE IS ENOUGH UNCERTAINTY. CIGS SHOULD SLOWLY LIFT THURSDAY MORNING WITH MORE IMPROVEMENT DURING THE AFTERNOON AS THE BOUNDARY LIFTS BACK THROUGH THE REGION AS A WARM FRONT. A COLD FRONT CROSSES THE REGION FRIDAY AFTERNOON AND EVENING BRINGING SHRA/TSRA...ALONG WITH A BREEZY SSW WIND AHEAD OF THE FRONT. HIGH PRESSURE RETURNS SATURDAY AND SUNDAY AND MOVES OFFSHORE MONDAY. && .MARINE... BACKDOOR COLD FRONT HAS LOCATED JUST SOUTH AND WEST OF THE WATER THIS AFTERNOON. THE RESULT IS N-NE FLOW...AVG 10-15 KT. STRONGER GRADIENT EXISTS OVER THE NRN COASTAL WATERS...WHERE A FEW GUSTS 25- 28 KT OBSERVED. SEAS HAVE BUILT TO 6-8 FT OVER THE NRN COASTAL ZONES...GENERALLY NORTH OF PARRAMORE ISLAND. FARTHER SOUTH...SEAS AVG 2-4 FT. SCA HEADLINES REMAIN IN EFFECT NORTH OF CAPE CHARLES LIGHT FOR SEAS. GRADIENT WINDS EXPECTED TO DIMINISH TONIGHT AOB 15 KT...BUT SEAS WILL REMAIN ELEVATED (4-7 FT) AS NE FLOW PERSISTS. BACKDOOR FRONT REMAINS JUST SOUTH AND WEST OF THE WATER THURS...SLOWLY LIFTING BACK NWD. FLOW BECOMES MORE ONSHORE...E-NE GENERALLY 10-15 KT. SEAS REMAIN 4-6 FT NORTH OF PARRAMORE ISLAND...DROPPING BELOW 5 FT SOUTH. BACKDOOR FRONT LIFTS NORTH OF THE WATER FINALLY THURS NIGHT-FRI MORNING AS A WARM FRONT. FLOW BECOMES SLY...INCREASING TO AROUND 15 KT RIVERS/BAY/SOUND AND 20 KT COASTAL WATERS. MARGINAL SCA CONDITIONS ARE POSSIBLE FRI AFTERNOON AS THE GRADIENT STRENGTHENS IN ADVANCE OF AN APPROACHING COLD FRONT. WILL HOLD OFF ON HEADLINES DUE TO 4TH PERIOD AND BEING MARGINAL ATTM. COLD FRONT CROSSES THE WATERS FRI NIGHT...WITH FLOW BECOMING NWLY POST FRONTAL. BEST CAA REMAINS NORTH OF THE LOCAL AREA...BUT A FEW GUSTS TO 20 KT POSSIBLE IN THE BAY AND 25 KT COASTAL WATERS BRIEFLY LATE FRI NIGHT-EARLY SAT MORNING. SEAS BUILD TO 4-6 FT FRI NIGHT. HIGH PRESSURE BUILDS OVER THE WATERS THIS WEEKEND...RESULTING IN SUB-SCA CONDITIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ654. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAS NEAR TERM...JDM SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...AJZ/JEF MARINE...SAM
ADDRESSED IN PREVIOUS FORECAST DISCUSSIONS. THE BIGGEST UNKNOWN IS
WHAT THE POTENTIAL FOR WET BULB COOLING WILL BE AS DEWPOINTS HAVE
BEEN FORECASTED TO BE AROUND THE 32 DEGREE MARK. THE IDEA THIS PACKAGE IS TO FAVOR A WARMER SOLUTION GIVEN THE OVERALL AMOUNT OF MIDLEVEL WARM AIR ADVECTION THAT IS EXPECTED TO OCCUR. MOS GUIDANCE IS WARM WITH SURFACE TEMPERATURES AT BAD AXE WELL ABOVE THE FREEZING MARK...AND ALSO WARM WITH SURFACE DEWPOINTS. WHILE IT REMAINS POSSIBLE THAT ISOLATED LOCATIONS COULD SEE SOME LIGHT FREEZING RAIN OCCUR ON ELEVATED SURFACES...THE BREADTH OF MODEL OUTPUT ALONG WITH COLLABORATIVE CONCERNS LONG TERM...WEDNESDAY THROUGH NEXT TUESDAY THE LONG TERM FORECAST LOOKS TO START OFF QUITE WET AS AN ACTIVE PATTERN REMAINS OVER THE GREAT LAKES THROUGH FRIDAY. TO START OFF WEDNESDAY MORNING...A WEAK SURFACE LOW TRACKING ALONG A STATIONARY FRONT WILL BRING SOME LIGHT RAINS SHOWERS TO SOUTHEAST MICHIGAN. WHILE THERE IS A POTENTIAL FOR SOME THUNDER ASSOCIATED WITH THESE SHOWERS /ESPECIALLY TOWARDS THE OHIO BORDER/ ...INSTABILITY IS UNIMPRESSIVE FOR WEDNESDAY AND CONFIDENCE IS LOW THAT THUNDERSTORMS WILL DEVELOP. OVERALL...CURRENT THINKING IS THAT WHILE CURRENT MODEL RUNS SHOW RAIN PRETTY MUCH THROUGHOUT ALL OF WEDNESDAY... THE BEST CHANCE FOR THESE SHOWERS WILL BE IN THE MORNING HOURS...WITH A BRIEF DRY PERIOD OR AT LEAST RAIN BECOMING MORE SCATTERED IN THE AFTERNOON AS SUBSIDENCE MAKES ITS WAY INTO THE REGION. HIGH TEMPERATURES WILL BE FAIRLY COOL ON WEDNESDAY /MID TO UPPER 40S/ ACROSS THE REGION. RAIN SHOWERS RETURN AS A STRONGER AND DEEPER LOW PRESSURE SYSTEM TRACKS ACROSS MICHIGAN EARLY THURSDAY MORNING. THIS LOW WILL FORCE A WARM FRONT INTO THE REGION...BRINGING A ROUND A RAIN SHOWERS AND THUNDERSTORMS AFTER SUNRISE. WITH BETTER FORCING AND PLENTY OF MOISTURE...CONFIDENCE IN THUNDERSTORM DEVELOPMENT IS HIGHER. MAIN CONCERN WITH THIS SYSTEM IS ON THE TRACK AND HOW FAR NORTH THE WARM FRONT CAN PUSH. THE FURTHER NORTH THE WARM FRONT CAN SLIDE...THE FURTHER NORTH THE WARM AIR CAN ALSO FILTER. THIS WARM FRONT WILL DETERMINE HOW HIGH OUR MAX TEMPS ON THURSDAY WILL GET...WHICH COULD BE A DIFFERENCE OF NEARLY 15 DEGREES DEPENDING ON IF/WHEN/HOW FAR THE FRONT SLIDES. FOR NOW...HAVE OPTED TO GO WITH THE FURTHER NORTH TRACK AS MODELS ARE TRENDING ON MORE NORTHERLY ROUTE IN RECENT RUNS. THIS WILL ALLOW TEMPS ON THURSDAY TO MAKE IT INTO THE UPPER 60S IN THE SOUTHERN CWA AND ONLY IN THE MID 50S ACROSS THE SAGINAW VALLEY AND NORTHERN THUMB. DEPENDING ON HOW FAR NORTH THE LOW TRACKS WE COULD ALSO BE IMPACTED BY THE COLD FRONT WITH THE SYSTEM. THIS WOULD BRING ANOTHER ROUND OF MORE INTENSE SHOWERS AND THUNDERSTORMS TO SOUTHEAST MICHIGAN LATE THURSDAY AFTERNOON AND EVENING. FOR NOW HAVE KEPT OUT ANY MENTION OF SEVERE WEATHER ON THURSDAY AFTERNOON AS THE TRACK OF THE SYSTEM IS STILL UNCERTAIN...HOWEVER WILL HAVE TO KEEP AN EYE ON THIS SYSTEM OVER THE NEXT DAY TO DETERMINE IF ANY SEVERE WEATHER WILL BE ANTICIPATED. FOR FRIDAY AND THE WEEKEND...RAIN SHOWERS WILL MOVE EASTWARD ON FRIDAY MORNING...FOLLOWED BY SURFACE HIGH PRESSURE BUILDING INTO THE AREA RESULTING IN A RETURN TO DRY WEATHER. THIS HIGH WILL STICK AROUND THROUGH SUNDAY RESULTING IN NICE SPRINGTIME WEATHER /HIGHS IN THE MID 50S TO LOW 60S AND PARTLY CLOUDY SKIES/. THE NEXT WEATHER MAKER ARRIVES MONDAY...BUT THE TIMING IS VERY INCONSISTENT AMONG MODELS AND THEREFORE ONLY FELT CONFIDENT PUTTING IN CHANCE POPS FOR THE MONDAY THROUGH TUESDAY TIMEFRAME. HIGH TEMPS WILL REMAIN IN THE UPPER 50S TO LOW 60S ON MONDAY AND TUESDAY. MARINE... STRONG GUSTY NORTHWEST WINDS WILL BEGIN TUESDAY NIGHT AND LAST THROUGH WEDNESDAY. WINDS COULD REACH UP TO 25 KNOTS OVER LAKE HURON DURING THIS TIMEFRAME WITH WAVES BUILDING OVER 4 FEET ACROSS THE LAKE HURON NEARSHORE WATERS. THEREFORE... SMALL CRAFT ADVISORIES REMAIN IN EFFECT UNTIL WEDNESDAY EVENING. IN ADDITION TO GUSTY WINDS...RAIN WILL BE POSSIBLE TUESDAY NIGHT AND INTO WEDNESDAY AS A WEAK LOW PRESSURE SYSTEM SLIDES ACROSS THE AREA. A BETTER CHANCE FOR RAIN AS WELL AS THUNDERSTORMS WILL ARRIVE WEDNESDAY NIGHT AND INTO THURSDAY AS A STRONGER LOW TRACKS ACROSS THE CENTRAL GREAT LAKES. WIND GUSTS ARE EXPECTED TO INCREASE UP TO 30 KNOTS IN SOME LOCATIONS WITH THIS SYSTEM. SMALL CRAFT ADVISORIES MAY BE NEEDED ONCE AGAIN FOR THURSDAY NIGHT AND FRIDAY MORNING. HIGH PRESSURE...DRY CONDITIONS...AND CALMER WINDS RETURN FOR FRIDAY AND INTO THE WEEKEND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT WEDNESDAY FOR LHZ421-441. SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LHZ442. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT UPDATE.......BT SHORT TERM...CB LONG TERM....RK MARINE.......RK YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 PM EDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 448 PM EDT TUE APR 7 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THAT THE CONFLUENT FLOW THAT HAS BEEN ACROSS THE UPPER GREAT LAKES IS SHIFTING E AND NE AS THE NRN STREAM TROF OVER ERN CANADA IS SLOWLY LIFTING OUT AND SRN BRANCH RIDGE OVER THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST IS GRADUALLY BUILDING NE AND E. SFC HIGH PRES SUPPORTED BY THE CONFLUENT FLOW ALOFT RIDGES W-E ACROSS NRN ONTARIO INTO SRN QUEBEC. ALTHOUGH THERE HAVE BEEN SOME MID-LEVEL RADAR RETURNS ACROSS THE FCST AREA...ESPECIALLY EARLIER TODAY...THE VERY DRY AIR AT THE LOWER LEVELS EMANATING FROM THE HIGH PRES RIDGE HAS RESULTED IN DRY WEATHER ACROSS THE FCST AREA TODAY. IN FACT...THE KEWEENAW AND ERN UPPER MI HAVE ENJOYED MOSTLY SUNNY SKIES FOR A GOOD PART OF THE DAY. TO THE S...WARM FRONT/STATIONARY FRONT EXTENDS FROM KS ACROSS CNTRL IL INTO NRN OHIO. TO THE W AND SW...A WELL-DEFINED SHORTWAVE IS TRACKING ENE ACROSS SE SASKATCHEWAN WHILE WEAKER WAVES ARE MOVING ACROSS WY/CO AND OUT ACROSS THE PLAINS. THESE FEATURES WILL PLAY A ROLE IN A CHALLENGING FCST HERE TONIGHT/WED. INITIALLY...EXPECT DRY WEATHER TO PREVAIL THIS EVENING UNDER A CONTINUED FEED OF DRY LOW-LEVEL AIR FROM THE E AND NE. SFC DWPTS AS OF 19Z WERE STILL MOSTLY IN THE 5-10F RANGE ALONG THE MI/WI BORDER...INDICATING THE DRYNESS THAT IS STILL AT THE SFC...AND LATEST RAP FCST SOUNDINGS SHOW THE DRY AIR IN THE LOWER LEVELS HANGING ON DURING THE EVENING. LATER TONIGHT INTO WED...FOCUS SHIFTS TO THE AFORMENTIONED SHORTWAVES. THE STRONGER NRN WAVE WILL REACH NRN ONTARIO EARLY WED MORNING WHILE THE WEAKER SRN WAVES WILL TRACK INTO THE UPPER LAKES. TRACK OF THE STRONGER NRN WAVE INDICATES ITS MAIN FORCING WILL PASS N OF HERE...AND THAT IS WHAT MODELS SHOW FOR PROGRESSION OF DEEP LAYER QVECTORS. FARTHER S...THE WEAKER SRN WAVES WILL BE ABLE TO INTERACT WITH THE SFC-850MB WARM FRONT AND CONSIDERABLY MORE GENEROUS MOISTURE AS WELL AS ABUNDANT INSTABILITY. LEAD SUBTLE WAVE IS ALREADY GENERATING AN EXPANDING AREA OF SHRA/TSRA IN SRN MN/NW IA ON THE MUCAPE GRADIENT PER LATEST SPC MESOANALYSIS. THRU WED MORNING...MODELS SHOW 850MB WARM FRONT NEVER LIFTING ANY FARTHER N THAN SRN WI. BELIEVE THOSE MODEL SOLUTIONS WHICH SHOW THE MAIN AREA OF PCPN PASSING S OF UPPER MI TONIGHT/WED MORNING CLOSER TO 850MB WARM FRONT OR EVEN SFC FRONT ARE PROBABLY ON THE RIGHT TRACK. THIS WOULD BE ESPECIALLY TRUE IF SIGNIFICANT CONVECTION ENDS UP DEVELOPING/EXPANDING NEAR THE WARM FRONT...A DEFINITE POSSIBILITY GIVEN THE MAGNITUDE OF INSTABILITY THAT WILL REMAIN MUCH FARTHER S. WHILE THE SHRA/TSRA MOVING ACROSS SRN MN INTO SW WI IS A CONCERN...THAT PCPN SHOULD TEND TO PEEL MORE EASTWARD WITH TIME AS THE SHRA/TSRA SHOULDN`T BREAK TOO FAR AWAY FROM THE INSTABILITY GRADIENT WHICH WILL REMAIN WELL S OF HERE. SO...THE GFS WHICH CARRIES 1/3RD TO 1/2 INCH OF PCPN INTO SCNTRL UPPER MI CERTAINLY LOOKS LIKE AN OUTLIER COMPARED TO THE OTHER MODELS WHICH ARE MUCH LIGHTER ON PCPN. NONETHELESS...TAIL END OF NRN SHORTWAVE WILL PROVIDE SUPPORT FOR AN EXTENSION OF PCPN N AND NW FROM HEAVIER PCPN TO THE S. UTILIZING A CONSENSUS APPROACH FOR POPS...WEIGHTED TOWARD HIGH RES GUIDANCE...WILL SPREAD A BAND OF CHC POPS ACROSS THE AREA OVERNIGHT/WED MORNING WITH TREND TOWARD LOWER POPS OVER THE NRN/ERN FCST AREA. WILL INCLUDE LIKELY POPS INTO MENOMINEE COUNTY. PCPN WILL END (OR DIMINISH TO DZ BEFORE ENDING) FROM SW TO NE MID MORNING THRU EARLY AFTN. PTYPE IS A CHALLENGE. INITIAL DRY AIR MASS/EVAPORATIVE COOLING SHOULD MAKE SNOW THE MORE DOMINANT PTYPE. HOWEVER...PERUSAL OF MODEL FCST SOUNDINGS SHOW TEMP PROFILE HOVERING AROUND 0C OVER A FAIRLY SIGNIFICANT DEPTH...INDICATING A VARIETY OF PTYPES WILL BE POSSIBLE WITH ONLY VERY SLIGHT CHANGES TO THE TEMP PROFILE. SO...FCST WILL REFLECT A WINTRY MIX OF SN/IP/FZRA/RA AT MOST LOCATIONS...THOUGH MAINLY SN IS MORE LIKELY IN HIGHER TERRAIN AREAS. FOR PCPN AMOUNTS...EXPECT TOTAL WATER EQUIVALENT PCPN OF ROUGHLY 0.05 TO 0.15 INCHES....GREATEST SCNTRL. SNOW AMOUNTS SHOULD BE UNDER 1 INCH...AND WHERE FRZA OCCURS...A COUPLE OF HUNDREDTHS ARE POSSIBLE. AT THIS POINT...ADVY HEADLINES ARE NOT WARRANTED. IF FOR SOME REASON TRENDS THIS EVENING POINT TOWARD HEAVIER PCPN REACHING THE AREA...HEADLINES WILL NEED TO BE RECONSIDERED. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE APR 7 2015 ...AREAS OF FREEZING RAIN/ICING WED NIGHT INTO THU MORNING AND POSSIBLE HEAVY SNOW THU NIGHT... LARGE SCALE UPPER LEVEL PATTERN TO START THE LONG TERM FEATURES TROUGHING FM CENTRAL CANADA SOUTHWEST ACROSS MUCH OF THE WESTERN CONUS. MAIN SHORTWAVES WITHIN THE TROUGH ON WEDNESDAY NIGHT WILL BE DIVING SOUTHEAST ACROSS MANITOBA AND STREAMING EASTWARD NEAR THE FOUR CORNERS REGION. MAIN JET STREAKS WITHIN THE FLOW PATTERN ARE ORIENTED FM GREAT LAKES TO NEW ENGLAND AND PUSHING ACROSS NORTHERN MEXICO. AT THE SFC...MAIN CYCLONE IS VCNTY OF CNTRL PLAINS WITH WARM FRONT EAST ACROSS THE OHIO VALLEY...LIFTING NORTHWARD. WEAKER LEAD SHORTWAVE/INCREASING DIVERGENCE IN RRQ OF GREAT LAKES JET/WARM AIR ADVECTION COMBINE TO BRING SOME PRECIP IN THE FORM OF RAIN SHOWERS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING. GFS/ECMWF/GEM-NH QUICKER IN BRINGING PRECIP OVER AREA...MORE 06Z-12Z THURSDAY. NAM IS DELAYED...FAVORING 12Z-18Z ON THURSDAY. EITHER WAY THINK BEST FOCUS FOR RAIN WILL BE ON NOSE OF VEERING H85 JET MAINLY IMPACTING SOUTH AND EAST CWA. TSRA THAT COULD BE ONGOING ALONG WARM FRONT COULD FURTHER DISRUPT MOISTURE TRANSPORT INTO UPPER GREAT LAKES. DUE TO THESE REASONS...LIKE THE IDEA OF LESS QPF SINCE LARGER SCALE FORCING OVER UPR MICHIGAN IS GENERALLY WEAK. SOUNDINGS AHEAD OF ANY POTENTIAL PRECIP INDICATE LOW-LEVEL MOISTURE TO H9 BUT DRY AIR ABOVE THROUGH H5 MUCH OF WEDNESDAY EVENING. SFC WINDS FM EAST BTWN HIGH PRESSURE RIDGE OVER EASTERN CANADA AND LOW PRESSURE LIFTING NORTHEAST OVER THE CNTRL PLAINS SUPPORTS BEST CHANCE OF DZ/FZDZ GENERATED BY UPSLOPE LIFTING OVER HIGHER TERRAIN OF CNTRL CWA FM MICHIGAMME HIGHLANDS IN BARAGA AND MARQUETTE COUNTY SOUTHWEST TO MUCH OF IRON AND DICKINSON COUNTIES. EITHER FM THE FZDZ OR EVENTUALLY ARRIVAL OF LIGHT FZRA...LIGHT ICING IS LIKELY ON WEDNESDAY NIGHT AS TEMPS WILL STAY AT OR BLO FREEZING MOST OF THE NIGHT. MAIN CONCERN WOULD BE ON UNTREATED ROADS AND SIDEWALKS BUT THERE COULD ALSO BE SOME ICING THAT WOULD IMPACT ELEVATED OBJECTS SUCH AS TREES AND POWERLINES. BEST SHOT OF MOST ICING WILL BE OVER THE HIGHER TERRAIN AREAS FM BARAGA AND MARQUETTE COUNTY TO IRON AND DICKINSON COUNTY. DID NOT GET TOO SPECIFIC BTWN DZ/FZDZ AND RAIN/FZRA. SINCE EVEN IN THE DRIER SCENARIO THERE WOULD BE MEASURABLE QPF...WENT WITH RAIN/FZRA. WILL KEEP MENTION OF THIS IN HWO/EHWO...BUT NO HEADLINE ISSUED NOW AS AT THIS POINT SEEMS THAT AT WORST COULD NEED AN ADVY. BRIEF LULL POSSIBLE LATER THURSDAY MORNING INTO THURSDAY AFTERNOON IN BETWEEN SHORTWAVES...LEAD ONE LIFTING ACROSS EASTERN ONTARIO AND A MUCH STRONGER ONE...EDGING EASTWARD ACROSS CNTRL PLAINS...SET TO ARRIVE OVER UPR GREAT LAKES THURSDAY NIGHT. SOUNDINGS FOR LATER THURSDAY INDICATE SOME MOISTURE MAY STICK AROUND ON NORTHERN EDGE OF SFC LOW LIFTING NORTHEAST FROM THE CNTRL MISSISSIPPI RIVER VALLEY TOWARD THE WESTERN GREAT LAKES...BUT SEEMS THAT NET FORCING FOR ANY PRECIP WILL BE MINIMAL. NORTHERN EDGE OF HIGHER MLCAPE AND INTERSECTION OF LOW-LEVEL AND UPPER LEVEL JET AND H85 THETA-E AXIS/MAX WARM AIR ADVECTION WOULD KEEP POTENTIAL FOR TSRA STAYING WELL TO THE SOUTHEAST OF UPR MICHIGAN...LIKELY OVER LOWER GREAT LAKES OR OHIO VALLEY DEPENDING ON LOCATION OF EMBEDDED WEAKER CONVECTIVELY DRIVEN SHORTWAVES IN THE WSW FLOW ALOFT. GENERALLY QUIET WEATHER SHOULD PREVAIL OVER UPPER LAKES THURSDAY AFTN UNTIL MAIN SHORTWAVE ARRIVES ON THURSDAY NIGHT. MOISTURE ADVECTION INTO THE AREA MAY CONTINUE TO SPUR ON SOME SHOWERS OR PATCHY RAIN...SO KEPT CHANCES GOING THROUGH THE PERIOD DESPITE THE MINIMAL FORCING. MODEL DIFFERENCES WITH STRENGTH AND WESTWARD EXTENT OF THURSDAY NIGHT SHORTWAVE IS THE MAIN ISSUE ON INTO FRIDAY MORNING. OVERALL... RECENT NAM/GEM-NH RUNS WERE FARTHER WEST WITH UPPER WAVE AND SFC LOW WHILE THE 00Z ECMWF WAS MUCH FASTER WITH EASTWARD PUSH OF THE SHORTWAVE/SFC LOW AND COLD FRONT. GFS REPRESENTED A COMPROMISE SOLUTION. BY FAR...00Z AND 12Z ECMWF ARE DRIEST...INDICATING LESS THAN 0.25 INCH OF QPF FM 00Z FRIDAY TO 12Z FRIDAY. MEANWHILE... NAM/GFS/GEM-NH SHOWED QPF AMOUNTS AT LEAST UP TO 1 INCH...SO QUITE THE DIFFERENCE. 12Z NAM TRENDED MORE LIKE THE GFS IN TERMS OF LOCATION OF SFC LOW FM 00Z FRIDAY TO 12Z FRIDAY. IN TERMS OF QPF...NAM TRENDED AWAY FM STRIPE OF 1.5 INCH PLUS AMOUNTS IT WAS SHOWING BUT STILL HAS UP TO 1.25 INCHES OVER PARTS OF WESTERN UPR MICHIGAN. IN FACT...IN THE VCNTY OF KIWD IS HAS TRENDED MUCH WETTER AS 00Z RUN SHOWED LESS THAN 0.10 INCH...BUT 12Z RUN NOW HAS ALMOST 0.75 INCHES. GUESSING THIS IS DUE TO MORE PHASING OCCURRING BTWN SHORTWAVE CROSSING THE UPPER LAKES AND THE APPROACHING WAVE DRIVING SOUTHEAST OVER MANITOBA AND NORTHERN ONTARIO WHICH IN TURN INCREASES RIGHT ENTRANCE JET STREAK DIVERGENCE AND ASSOCIATED MID-LEVEL FGEN. 12Z GFS SIMILAR TO PREVIOUS RUNS WITH SFC LOW POSITION...BUT NOW FOCUSES QPF MORE OVER WESTERN CWA. GFS SHOWS NOT ONLY MAIN SHORTWAVE LIFTING OVER UPPER GREAT LAKES AND WAVE OVER NORTHERN ONTARIO...BUT ALSO ANOTHER WAVE TRYING TO SNEAK IN FM NORTHERN PLAINS. SCENARIO JUST BECOMES MORE COMPLICATED YET. PTYPE WITH MOST OF THE PRECIP WOULD BE RAIN CHANGING TO SNOW. POSSIBLE FZRA AS WELL AS ADVECTION OF COLDER LOW- LEVEL AIRMASS UNDERCUTS LINGERING WARM LAYER ALOFT AT H8-H75. SIGNAL FOCUSING THAT FAR WEST VCNTY OF KIWD COULD SEE HEAVY SNOW THURSDAY EVENING INTO THE EARLY MORNING OF FRIDAY DUE TO QUICKER CHANGE FM RAIN TO SNOW AND GREATER POTENTIAL FOR HEAVIER QPF. WILL CONTINUE TO MENTION THIS IN THE HWO/EHWO BUT NOT HIT IT UP MUCH HARDER JUST YET AS UNCERTAINTY REMAINS SINCE THE TYPICALLY BETTER PERFORMING ECMWF HAS BEEN CONSISTENTLY NOT NEAR AS BULLISH WITH THE SYSTEM AS OTHER MODELS. AND ITS REALLY NOT EVEN CLOSE. LOW PRESSURE SYSTEM EXITS ACROSS EASTERN CANADA ON FRIDAY. LINGERING AIRMASS IS COOL THOUGH AS LOWERED TEMPS WITH THERMAL TROUGH AT H85 REMAINING OVER THE AREA. SHOULD STAY MOSTLY CLOUDY EVEN FARTHER INLAND WITH POSSIBLE INSTABILITY RAIN/SNOW SHOWERS SINCE THE THERMAL TROUGH STAYS IN THE VCNTY. HIGH PRESSURE SLIDES OVERHEAD TO START THE WEEKEND SO LOOKING FOR DRY AND MUCH WARMER CONDITIONS ON SATURDAY. WINDS BECOME SOUTHWEST AS RIDGE PASSES SATURDAY AFTN. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 50S OVER MOST CWA. BY LATE WEEKEND...UPPER PATTERN SHOWS LARGER TROUGH OVER WESTERN CANADA AND NORTHWEST CONUS...WITH MORE COMPACT UPPER LOW TRACKING OVER THE SOUTHWEST CONUS. THERE IS A LOT OF UNCERTAINTY IN HOW THAT SOUTHERN STREAM WAVE EVOLVES. PREVIOUS ECMWF SHOWED A WRAPPED UP SFC LOW OVER THE CNTRL PLAINS...WHILE THE 12Z ECMWF SHOWS NOTHING OF THE SORT. ESSENTIALLY...SEE NO REASON TO STRAY FM CONSENSUS BEYOND THE LATE WEEK SYSTEM GIVEN THE BIGGER UNCERTAINTY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 135 PM EDT TUE APR 7 2015 A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE. EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE END OF THE FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 448 PM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE FROM NRN ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...EXPECT NE WINDS OF 20-30KT TONIGHT...WITH SOME GALE FORCE GUSTS TO AROUND 35 KT THRU THE EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LOW PRES LIFTS NE FROM THE CENTRAL PLAINS INTO THE GREAT LAKES REGION. AT THIS TIME...IT APPEARS THE LOW WILL NOT BE STRONG ENOUGH TO RESULT IN GALES AS THE LOW APPROACHES AND THEN DEPARTS. WINDS WILL BACK TO THE N THU AND THEN NW 20-30KT THU NIGHT INTO FRI AS THE LOW SHIFTS TO THE E AND HIGH PRES BUILDS INTO THE PLAINS. A PERIOD OF LIGHT WINDS WILL OCCUR FRI NIGHT INTO SAT AS HIGH PRES RIDGE MOVES ACROSS THE UPPER LAKES. S WINDS WILL THEN BE ON THE INCREASE TO AT LEAST 10-20KT ON SUN AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E TO THE UPPER MISSISSIPPI VALLEY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
415 PM EDT TUE APR 7 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE APR 7 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS. HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS RDG AND THE TROF ALONG THE W COAST. MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI. TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S. TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT... ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE APR 7 2015 ...AREAS OF FREEZING RAIN/ICING WED NIGHT INTO THU MORNING AND POSSIBLE HEAVY SNOW THU NIGHT... LARGE SCALE UPPER LEVEL PATTERN TO START THE LONG TERM FEATURES TROUGHING FM CENTRAL CANADA SOUTHWEST ACROSS MUCH OF THE WESTERN CONUS. MAIN SHORTWAVES WITHIN THE TROUGH ON WEDNESDAY NIGHT WILL BE DIVING SOUTHEAST ACROSS MANITOBA AND STREAMING EASTWARD NEAR THE FOUR CORNERS REGION. MAIN JET STREAKS WITHIN THE FLOW PATTERN ARE ORIENTED FM GREAT LAKES TO NEW ENGLAND AND PUSHING ACROSS NORTHERN MEXICO. AT THE SFC...MAIN CYCLONE IS VCNTY OF CNTRL PLAINS WITH WARM FRONT EAST ACROSS THE OHIO VALLEY...LIFTING NORTHWARD. WEAKER LEAD SHORTWAVE/INCREASING DIVERGENCE IN RRQ OF GREAT LAKES JET/WARM AIR ADVECTION COMBINE TO BRING SOME PRECIP IN THE FORM OF RAIN SHOWERS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING. GFS/ECMWF/GEM-NH QUICKER IN BRINGING PRECIP OVER AREA...MORE 06Z-12Z THURSDAY. NAM IS DELAYED...FAVORING 12Z-18Z ON THURSDAY. EITHER WAY THINK BEST FOCUS FOR RAIN WILL BE ON NOSE OF VEERING H85 JET MAINLY IMPACTING SOUTH AND EAST CWA. TSRA THAT COULD BE ONGOING ALONG WARM FRONT COULD FURTHER DISRUPT MOISTURE TRANSPORT INTO UPPER GREAT LAKES. DUE TO THESE REASONS...LIKE THE IDEA OF LESS QPF SINCE LARGER SCALE FORCING OVER UPR MICHIGAN IS GENERALLY WEAK. SOUNDINGS AHEAD OF ANY POTENTIAL PRECIP INDICATE LOW-LEVEL MOISTURE TO H9 BUT DRY AIR ABOVE THROUGH H5 MUCH OF WEDNESDAY EVENING. SFC WINDS FM EAST BTWN HIGH PRESSURE RIDGE OVER EASTERN CANADA AND LOW PRESSURE LIFTING NORTHEAST OVER THE CNTRL PLAINS SUPPORTS BEST CHANCE OF DZ/FZDZ GENERATED BY UPSLOPE LIFTING OVER HIGHER TERRAIN OF CNTRL CWA FM MICHIGAMME HIGHLANDS IN BARAGA AND MARQUETTE COUNTY SOUTHWEST TO MUCH OF IRON AND DICKINSON COUNTIES. EITHER FM THE FZDZ OR EVENTUALLY ARRIVAL OF LIGHT FZRA...LIGHT ICING IS LIKELY ON WEDNESDAY NIGHT AS TEMPS WILL STAY AT OR BLO FREEZING MOST OF THE NIGHT. MAIN CONCERN WOULD BE ON UNTREATED ROADS AND SIDEWALKS BUT THERE COULD ALSO BE SOME ICING THAT WOULD IMPACT ELEVATED OBJECTS SUCH AS TREES AND POWERLINES. BEST SHOT OF MOST ICING WILL BE OVER THE HIGHER TERRAIN AREAS FM BARAGA AND MARQUETTE COUNTY TO IRON AND DICKINSON COUNTY. DID NOT GET TOO SPECIFIC BTWN DZ/FZDZ AND RAIN/FZRA. SINCE EVEN IN THE DRIER SCENARIO THERE WOULD BE MEASURABLE QPF...WENT WITH RAIN/FZRA. WILL KEEP MENTION OF THIS IN HWO/EHWO...BUT NO HEADLINE ISSUED NOW AS AT THIS POINT SEEMS THAT AT WORST COULD NEED AN ADVY. BRIEF LULL POSSIBLE LATER THURSDAY MORNING INTO THURSDAY AFTERNOON IN BETWEEN SHORTWAVES...LEAD ONE LIFTING ACROSS EASTERN ONTARIO AND A MUCH STRONGER ONE...EDGING EASTWARD ACROSS CNTRL PLAINS...SET TO ARRIVE OVER UPR GREAT LAKES THURSDAY NIGHT. SOUNDINGS FOR LATER THURSDAY INDICATE SOME MOISTURE MAY STICK AROUND ON NORTHERN EDGE OF SFC LOW LIFTING NORTHEAST FROM THE CNTRL MISSISSIPPI RIVER VALLEY TOWARD THE WESTERN GREAT LAKES...BUT SEEMS THAT NET FORCING FOR ANY PRECIP WILL BE MINIMAL. NORTHERN EDGE OF HIGHER MLCAPE AND INTERSECTION OF LOW-LEVEL AND UPPER LEVEL JET AND H85 THETA-E AXIS/MAX WARM AIR ADVECTION WOULD KEEP POTENTIAL FOR TSRA STAYING WELL TO THE SOUTHEAST OF UPR MICHIGAN...LIKELY OVER LOWER GREAT LAKES OR OHIO VALLEY DEPENDING ON LOCATION OF EMBEDDED WEAKER CONVECTIVELY DRIVEN SHORTWAVES IN THE WSW FLOW ALOFT. GENERALLY QUIET WEATHER SHOULD PREVAIL OVER UPPER LAKES THURSDAY AFTN UNTIL MAIN SHORTWAVE ARRIVES ON THURSDAY NIGHT. MOISTURE ADVECTION INTO THE AREA MAY CONTINUE TO SPUR ON SOME SHOWERS OR PATCHY RAIN...SO KEPT CHANCES GOING THROUGH THE PERIOD DESPITE THE MINIMAL FORCING. MODEL DIFFERENCES WITH STRENGTH AND WESTWARD EXTENT OF THURSDAY NIGHT SHORTWAVE IS THE MAIN ISSUE ON INTO FRIDAY MORNING. OVERALL... RECENT NAM/GEM-NH RUNS WERE FARTHER WEST WITH UPPER WAVE AND SFC LOW WHILE THE 00Z ECMWF WAS MUCH FASTER WITH EASTWARD PUSH OF THE SHORTWAVE/SFC LOW AND COLD FRONT. GFS REPRESENTED A COMPROMISE SOLUTION. BY FAR...00Z AND 12Z ECMWF ARE DRIEST...INDICATING LESS THAN 0.25 INCH OF QPF FM 00Z FRIDAY TO 12Z FRIDAY. MEANWHILE... NAM/GFS/GEM-NH SHOWED QPF AMOUNTS AT LEAST UP TO 1 INCH...SO QUITE THE DIFFERENCE. 12Z NAM TRENDED MORE LIKE THE GFS IN TERMS OF LOCATION OF SFC LOW FM 00Z FRIDAY TO 12Z FRIDAY. IN TERMS OF QPF...NAM TRENDED AWAY FM STRIPE OF 1.5 INCH PLUS AMOUNTS IT WAS SHOWING BUT STILL HAS UP TO 1.25 INCHES OVER PARTS OF WESTERN UPR MICHIGAN. IN FACT...IN THE VCNTY OF KIWD IS HAS TRENDED MUCH WETTER AS 00Z RUN SHOWED LESS THAN 0.10 INCH...BUT 12Z RUN NOW HAS ALMOST 0.75 INCHES. GUESSING THIS IS DUE TO MORE PHASING OCCURRING BTWN SHORTWAVE CROSSING THE UPPER LAKES AND THE APPROACHING WAVE DRIVING SOUTHEAST OVER MANITOBA AND NORTHERN ONTARIO WHICH IN TURN INCREASES RIGHT ENTRANCE JET STREAK DIVERGENCE AND ASSOCIATED MID-LEVEL FGEN. 12Z GFS SIMILAR TO PREVIOUS RUNS WITH SFC LOW POSITION...BUT NOW FOCUSES QPF MORE OVER WESTERN CWA. GFS SHOWS NOT ONLY MAIN SHORTWAVE LIFTING OVER UPPER GREAT LAKES AND WAVE OVER NORTHERN ONTARIO...BUT ALSO ANOTHER WAVE TRYING TO SNEAK IN FM NORTHERN PLAINS. SCENARIO JUST BECOMES MORE COMPLICATED YET. PTYPE WITH MOST OF THE PRECIP WOULD BE RAIN CHANGING TO SNOW. POSSIBLE FZRA AS WELL AS ADVECTION OF COLDER LOW- LEVEL AIRMASS UNDERCUTS LINGERING WARM LAYER ALOFT AT H8-H75. SIGNAL FOCUSING THAT FAR WEST VCNTY OF KIWD COULD SEE HEAVY SNOW THURSDAY EVENING INTO THE EARLY MORNING OF FRIDAY DUE TO QUICKER CHANGE FM RAIN TO SNOW AND GREATER POTENTIAL FOR HEAVIER QPF. WILL CONTINUE TO MENTION THIS IN THE HWO/EHWO BUT NOT HIT IT UP MUCH HARDER JUST YET AS UNCERTAINTY REMAINS SINCE THE TYPICALLY BETTER PERFORMING ECMWF HAS BEEN CONSISTENTLY NOT NEAR AS BULLISH WITH THE SYSTEM AS OTHER MODELS. AND ITS REALLY NOT EVEN CLOSE. LOW PRESSURE SYSTEM EXITS ACROSS EASTERN CANADA ON FRIDAY. LINGERING AIRMASS IS COOL THOUGH AS LOWERED TEMPS WITH THERMAL TROUGH AT H85 REMAINING OVER THE AREA. SHOULD STAY MOSTLY CLOUDY EVEN FARTHER INLAND WITH POSSIBLE INSTABILITY RAIN/SNOW SHOWERS SINCE THE THERMAL TROUGH STAYS IN THE VCNTY. HIGH PRESSURE SLIDES OVERHEAD TO START THE WEEKEND SO LOOKING FOR DRY AND MUCH WARMER CONDITIONS ON SATURDAY. WINDS BECOME SOUTHWEST AS RIDGE PASSES SATURDAY AFTN. MIXING TO H9 WOULD SUPPORT HIGHS WELL INTO THE 50S OVER MOST CWA. BY LATE WEEKEND...UPPER PATTERN SHOWS LARGER TROUGH OVER WESTERN CANADA AND NORTHWEST CONUS...WITH MORE COMPACT UPPER LOW TRACKING OVER THE SOUTHWEST CONUS. THERE IS A LOT OF UNCERTAINTY IN HOW THAT SOUTHERN STREAM WAVE EVOLVES. PREVIOUS ECMWF SHOWED A WRAPPED UP SFC LOW OVER THE CNTRL PLAINS...WHILE THE 12Z ECMWF SHOWS NOTHING OF THE SORT. ESSENTIALLY...SEE NO REASON TO STRAY FM CONSENSUS BEYOND THE LATE WEEK SYSTEM GIVEN THE BIGGER UNCERTAINTY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 135 PM EDT TUE APR 7 2015 A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE. EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE END OF THE FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 AM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 PM EDT TUE APR 7 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE APR 7 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS. HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS RDG AND THE TROF ALONG THE W COAST. MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI. TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S. TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT... ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM EDT TUE APR 7 2015 THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE. TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING. THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW SLIGHT CHANCE POPS FOR THE DRIZZLE. ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH 900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS FREEZING RAIN THREAT IN THE HWO. AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME. AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE) WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST. WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER THE NEXT SEVERAL SHIFTS. THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 135 PM EDT TUE APR 7 2015 A STEADY ENE WIND ON THE SRN FLANK OF HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL CONTINUE TO ADVECT LOW-LEVEL DRY AIR INTO UPPER MI THRU THIS EVENING...RESULTING IN VFR CONDITIONS AT KIWD/KCMX/KSAW DESPITE CONSIDERABLE MID CLOUDS. AS A DISTURBANCE MOVES INTO THE GREAT LAKES TONIGHT...LIGHT PCPN WILL PROBABLY AFFECT ALL TERMINALS LATE TONIGHT INTO WED MORNING. ALONG WITH -SN...THERE MAY BE SOME -RA/-FZRA...THOUGH CONFIDENCE IS QUITE LOW ON PTYPE. EXPECT MVFR CONDITIONS TO EVENTUALLY DEVELOP...AND LINGER THRU THE END OF THE FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 AM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1210 PM EDT TUE APR 7 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 329 AM EDT TUE APR 7 2015 THE AREA WILL SEE A RELATIVELY WET PERIOD THROUGH MOST OF THE REST OF THIS WEEK. A STALLED OUT FRONTAL SYSTEM WILL REMAIN IN THE REGION. THE AREA WILL BE ON THE COOL NORTH SIDE OF THIS FRONT THROUGH WEDNESDAY. ROUNDS OF SHOWERS AND EVENTUALLY STORMS CAN BE EXPECTED. THE FRONT WILL LIFT NORTH OF THE AREA ON THURSDAY AND BRING WARMER AIR INTO THE AREA. STORMS WILL BECOME MORE LIKELY ON THURSDAY WITH A THREAT FOR SOME SEVERE WEATHER POSSIBLE DOWN SOUTH. CONDITIONS WILL QUIET DOWN THEN FOR THE END OF THE WORK WEEK AND NEXT WEEKEND AS THE ENTIRE FRONTAL SYSTEM PUSHES OUT OF THE AREA. && .UPDATE... ISSUED AT 1142 AM EDT TUE APR 7 2015 BEST COVERAGE OF SCATTERED RAIN SHOWERS THIS AFTERNOON SHOULD BE SOUTH OF I-96 CLOSER TO THE H8 BAROCLINIC ZONE. LATEST HRRR IS FAVORING THE AREA EAST AND SOUTH OF A LINE FROM AZO TO LAN. FARTHER NORTH AND WEST... MAINLY ISOLATED COVERAGE OF SHOWERS AT BEST. H5 PROGS SHOW SEVERAL VORTICITY MAXIMA EMBEDDED IN ZONAL FLOW ALOFT SO AM RELUCTANT TO GO COMPLETELY DRY IN THE NRN CWFA AFTER 18Z. TEMPS WILL STRUGGLE TO GET OUT OF THE 40S THIS AFTEROON WITH CLOUDS AND BRISK EAST FLOW. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 329 AM EDT TUE APR 7 2015 OUR MAIN CHALLENGES IN THE SHORT TERM WILL BE DETERMINING SEVERE WEATHER CHANCES FOR THU...AND TIMING ROUNDS OF RAIN THROUGH THE AREA THROUGH THU. WE ARE SEEING A COUPLE OF AREAS OF RAIN SHOWERS MOVING THROUGH THE AREA EARLY THIS MORNING. THESE RAIN SHOWERS ARE INSIGNIFICANT AS THE MUCH BETTER MOISTURE REMAINS WELL SOUTH OF THE AREA SOUTH OF THE COLD FRONT THAT DROPPED THROUGH THE AREA LAST EVENING. THE RAIN SHOWERS REMAIN ASSOCIATED WITH A RRQ OF A 130 KNOT UPPER JET STREAK THAT IS LEADING TO SOME MID LEVEL FGEN PROCESSES OVER THE AREA. WE EXPECT MOST OF THIS TO BE GONE BY 12Z THIS MORNING. AFTER A BREAK FOR MOST OF THE DAY TODAY...WE WILL SEE PCPN MOVE BACK IN/DEVELOP OVER THE AREA BEGINNING TOWARD MIDNIGHT TONIGHT. THIS PCPN WHICH SHOULD BE ALMOST ALL RAIN PER FCST SOUNDINGS WILL BE A BIT MORE ROBUST. WE WILL SEE AN UPPER WAVE MOVE INTO THE AREA ON THE SW FLOW ALOFT. THIS WAVE WILL HAVE BETTER SUPPORT AS THE LLJ WILL BE AIMED CLOSER TO THE AREA BRINGING BETTER MOISTURE TO THE AREA. LATER ON TONIGHT...THUNDER WILL BECOME POSSIBLE AS SUFFICIENT ELEVATED INSTABILITY MOVES UP TO JUST SOUTH OF I-96. THE ELEVATED NATURE OF THE STORMS WILL KEEP THE SEVERE THREAT FAIRLY LOW. WE WILL HAVE A SIMILAR SET UP FOR THE WED/WED NIGHT TIME FRAME. WE SHOULD SEE A BREAK FOR MOST OF THE AREA ON WED AS THE LLJ/MOISTURE TRANSPORT CORE SHIFTS EAST. YET ANOTHER UPPER WAVE AND ASSOCIATED LLJ/MOISTURE TRANSPORT AREA WILL MOVE IN ACROSS THE AREA FOR WED NIGHT. THERE WILL BE A BETTER THREAT FOR STORMS ACROSS THE ENTIRE CWFA AS A PLUME OF BETTER ELEVATED INSTABILITY MOVES IN. SEVERE WX THREAT IS STILL LOW THROUGH WED NIGHT WITH THE INSTABILITY BEING ELEVATED AND FCST SOUNDINGS INDICATING A LOWER THREAT FOR ALL OF THE THREATS. THU WILL BE THE DAY THAT PORTIONS OF THE AREA WILL SEE THE BEST CHC FOR SOME SEVERE WX. WE WILL SEE THE MAIN LONG WAVE TROUGH ACROSS THE WRN STATES LIFT NE TOWARD THE UPPER MIDWEST. THIS WILL LIFT THE FRONT BACK NORTH ACROSS AT LEAST A PORTION OF THE AREA. HOW FAR NORTH THE FRONT GOES WILL MAKE A BIG DIFFERENCE IN TEMPS AND SEVERE WX THREAT WITH QUITE A TEMP GRADIENT ACROSS THE FRONT. WE ARE TENDING TO THINK THE FRONT WILL LIFT TO ABOUT I-96 OR JUST NORTH AS SOME OF THE MODELS SEEM TO BE OVERDEVELOPING THE SFC LOW WITH THIS SYSTEM DUE TO EARLIER CONVECTION. THE WARM SECTOR COULD SEE TEMPS GET INTO THE 70S WITH DEW POINTS POSSIBLY GETTING WELL INTO THE 50S. THIS WOULD GENERATE SOME VALUES OF CAPE OVER 1000 J/KG. THE WARM FRONT WOULD BE A CONCERN WITH SOME DECENT DIRECTIONAL SHEAR AS ONE WOULD EXPECT. SOME LARGE HAIL AND DAMAGING WINDS WOULD BE POSSIBLE IN THE WARM SECTOR WITH FAIRLY HEALTHY CAPE IN THE -10 TO -30C LAYER AND UNIDIRECTIONAL WINDS. RAIN EARLIER ON MAY LIMIT INSTABILITY SOME. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 329 AM EDT TUE APR 7 2015 THE LONG TERM LOOKS WET AT THE BEGINNING AND END BUT DRY OVER MUCH OF THE WEEKEND. WE/RE GOING TO HANG ONTO THE POSSIBILITY OF THUNDERSTORMS THURSDAY NIGHT. THE GFS REMAINS SLOWER THAN THE ECMWF WHICH ALREADY MOVES LOW PRESSURE OVER THE CENTRAL CWA BY 00Z FRIDAY. MEANWHILE THE GFS STILL HAS THE LOW OVER EASTERN IOWA AND THE CWA IN THE WARM SECTOR. IF THE ECMWF IS CORRECT...TSRA CHANCES WOULD BE LOWER THAN IF THE SLOWER GFS VERIFIES. BOTH MODELS CLEAR THE TRAILING COLD FRONT BY FRIDAY MORNING WHICH MEANS WE/LL DRY OUT FRIDAY LEADING TO SUNNY WEATHER SATURDAY AND SUNDAY. THE NEXT SIGNIFICANT WEATHER WILL BE A SOUTHERN STREAM LOW THAT MOVES NORTHEAST FROM TEXAS LATE SUNDAY NIGHT AND MONDAY. THE GULF LOOKS TO BE WIDE OPEN SO MOISTURE AVAILABILITY SHOULDN/T BE A PROBLEM ESPECIALLY GIVEN THE 60+ KT LLJ. THIS LOOKS MOSTLY LIKE A RAIN EVENT AS INSTABILITY APPEARS LIMITED. TEMPS IN THE MID 50S FRIDAY WILL WARM TO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 745 AM EDT TUE APR 7 2015 RADAR SHOWS LIGHT SHOWERS INCREASING OVER SOUTHWEST LOWER MICHGIAN. SHOWERS WILL REMAIN IN THE VICINITY OF THE TAF SITES THIS MORNING BUT LIKELY WON/T RESTRICT VISIBILITIES. NORTHEAST WINDS HAVE ADVECTED IFR/MVFR CIGS FROM SAGINAW BAY INTO LANSING AND JACKSON. IT/S POSSIBLE THAT WE/LL SEE THESE CIGS BOUNCE AROUND A BIT...AS LANSING HAS JUST SCATTERED OUT. IFR CIGS SHOULD BE A THREAT UNTIL WINDS VEER MORE TO THE EAST RATHER THAN NORTHEAST AND TAKE THE LAKE OUT OF PLAY. && .MARINE... ISSUED AT 329 AM EDT TUE APR 7 2015 WE WILL BE LEAVING THE SMALL CRAFT ADVISORY AS IS WITH THIS FCST PACKAGE. A FAIRLY STIFF E/NE GRADIENT WILL REMAIN IN PLACE THROUGH TODAY AND INTO WED MORNING. WAVES WILL NOT BE TOO SIGNIFICANT ON THIS SIDE OF THE LAKE WITH THE OFFSHORE COMPONENT. && .HYDROLOGY... ISSUED AT 1210 PM EDT TUE APR 7 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY SLOWLY FALLING... BUT RISES IN RIVER LEVELS DUE TO RAINFALL ARE EXPECTED LATER THIS WEEK. 1 TO 2 INCHES OF WIDESPREAD RAINFALL IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY NIGHT INTO FRIDAY. PONDING OF WATER AND URBAN AND SMALL STREAM FLOODING IS POSSIBLE... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...99 AVIATION...04 HYDROLOGY...63 MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1142 AM EDT TUE APR 7 2015 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 329 AM EDT TUE APR 7 2015 THE AREA WILL SEE A RELATIVELY WET PERIOD THROUGH MOST OF THE REST OF THIS WEEK. A STALLED OUT FRONTAL SYSTEM WILL REMAIN IN THE REGION. THE AREA WILL BE ON THE COOL NORTH SIDE OF THIS FRONT THROUGH WEDNESDAY. ROUNDS OF SHOWERS AND EVENTUALLY STORMS CAN BE EXPECTED. THE FRONT WILL LIFT NORTH OF THE AREA ON THURSDAY AND BRING WARMER AIR INTO THE AREA. STORMS WILL BECOME MORE LIKELY ON THURSDAY WITH A THREAT FOR SOME SEVERE WEATHER POSSIBLE DOWN SOUTH. CONDITIONS WILL QUIET DOWN THEN FOR THE END OF THE WORK WEEK AND NEXT WEEKEND AS THE ENTIRE FRONTAL SYSTEM PUSHES OUT OF THE AREA. && .UPDATE... ISSUED AT 1142 AM EDT TUE APR 7 2015 BEST COVERAGE OF SCATTERED RAIN SHOWERS THIS AFTERNOON SHOULD BE SOUTH OF I-96 CLOSER TO THE H8 BAROCLINIC ZONE. LATEST HRRR IS FAVORING THE AREA EAST AND SOUTH OF A LINE FROM AZO TO LAN. FARTHER NORTH AND WEST... MAINLY ISOLATED COVERAGE OF SHOWERS AT BEST. H5 PROGS SHOW SEVERAL VORTICITY MAXIMA EMBEDDED IN ZONAL FLOW ALOFT SO AM RELUCTANT TO GO COMPLETELY DRY IN THE NRN CWFA AFTER 18Z. TEMPS WILL STRUGGLE TO GET OUT OF THE 40S THIS AFTEROON WITH CLOUDS AND BRISK EAST FLOW. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 329 AM EDT TUE APR 7 2015 OUR MAIN CHALLENGES IN THE SHORT TERM WILL BE DETERMINING SEVERE WEATHER CHANCES FOR THU...AND TIMING ROUNDS OF RAIN THROUGH THE AREA THROUGH THU. WE ARE SEEING A COUPLE OF AREAS OF RAIN SHOWERS MOVING THROUGH THE AREA EARLY THIS MORNING. THESE RAIN SHOWERS ARE INSIGNIFICANT AS THE MUCH BETTER MOISTURE REMAINS WELL SOUTH OF THE AREA SOUTH OF THE COLD FRONT THAT DROPPED THROUGH THE AREA LAST EVENING. THE RAIN SHOWERS REMAIN ASSOCIATED WITH A RRQ OF A 130 KNOT UPPER JET STREAK THAT IS LEADING TO SOME MID LEVEL FGEN PROCESSES OVER THE AREA. WE EXPECT MOST OF THIS TO BE GONE BY 12Z THIS MORNING. AFTER A BREAK FOR MOST OF THE DAY TODAY...WE WILL SEE PCPN MOVE BACK IN/DEVELOP OVER THE AREA BEGINNING TOWARD MIDNIGHT TONIGHT. THIS PCPN WHICH SHOULD BE ALMOST ALL RAIN PER FCST SOUNDINGS WILL BE A BIT MORE ROBUST. WE WILL SEE AN UPPER WAVE MOVE INTO THE AREA ON THE SW FLOW ALOFT. THIS WAVE WILL HAVE BETTER SUPPORT AS THE LLJ WILL BE AIMED CLOSER TO THE AREA BRINGING BETTER MOISTURE TO THE AREA. LATER ON TONIGHT...THUNDER WILL BECOME POSSIBLE AS SUFFICIENT ELEVATED INSTABILITY MOVES UP TO JUST SOUTH OF I-96. THE ELEVATED NATURE OF THE STORMS WILL KEEP THE SEVERE THREAT FAIRLY LOW. WE WILL HAVE A SIMILAR SET UP FOR THE WED/WED NIGHT TIME FRAME. WE SHOULD SEE A BREAK FOR MOST OF THE AREA ON WED AS THE LLJ/MOISTURE TRANSPORT CORE SHIFTS EAST. YET ANOTHER UPPER WAVE AND ASSOCIATED LLJ/MOISTURE TRANSPORT AREA WILL MOVE IN ACROSS THE AREA FOR WED NIGHT. THERE WILL BE A BETTER THREAT FOR STORMS ACROSS THE ENTIRE CWFA AS A PLUME OF BETTER ELEVATED INSTABILITY MOVES IN. SEVERE WX THREAT IS STILL LOW THROUGH WED NIGHT WITH THE INSTABILITY BEING ELEVATED AND FCST SOUNDINGS INDICATING A LOWER THREAT FOR ALL OF THE THREATS. THU WILL BE THE DAY THAT PORTIONS OF THE AREA WILL SEE THE BEST CHC FOR SOME SEVERE WX. WE WILL SEE THE MAIN LONG WAVE TROUGH ACROSS THE WRN STATES LIFT NE TOWARD THE UPPER MIDWEST. THIS WILL LIFT THE FRONT BACK NORTH ACROSS AT LEAST A PORTION OF THE AREA. HOW FAR NORTH THE FRONT GOES WILL MAKE A BIG DIFFERENCE IN TEMPS AND SEVERE WX THREAT WITH QUITE A TEMP GRADIENT ACROSS THE FRONT. WE ARE TENDING TO THINK THE FRONT WILL LIFT TO ABOUT I-96 OR JUST NORTH AS SOME OF THE MODELS SEEM TO BE OVERDEVELOPING THE SFC LOW WITH THIS SYSTEM DUE TO EARLIER CONVECTION. THE WARM SECTOR COULD SEE TEMPS GET INTO THE 70S WITH DEW POINTS POSSIBLY GETTING WELL INTO THE 50S. THIS WOULD GENERATE SOME VALUES OF CAPE OVER 1000 J/KG. THE WARM FRONT WOULD BE A CONCERN WITH SOME DECENT DIRECTIONAL SHEAR AS ONE WOULD EXPECT. SOME LARGE HAIL AND DAMAGING WINDS WOULD BE POSSIBLE IN THE WARM SECTOR WITH FAIRLY HEALTHY CAPE IN THE -10 TO -30C LAYER AND UNIDIRECTIONAL WINDS. RAIN EARLIER ON MAY LIMIT INSTABILITY SOME. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 329 AM EDT TUE APR 7 2015 THE LONG TERM LOOKS WET AT THE BEGINNING AND END BUT DRY OVER MUCH OF THE WEEKEND. WE/RE GOING TO HANG ONTO THE POSSIBILITY OF THUNDERSTORMS THURSDAY NIGHT. THE GFS REMAINS SLOWER THAN THE ECMWF WHICH ALREADY MOVES LOW PRESSURE OVER THE CENTRAL CWA BY 00Z FRIDAY. MEANWHILE THE GFS STILL HAS THE LOW OVER EASTERN IOWA AND THE CWA IN THE WARM SECTOR. IF THE ECMWF IS CORRECT...TSRA CHANCES WOULD BE LOWER THAN IF THE SLOWER GFS VERIFIES. BOTH MODELS CLEAR THE TRAILING COLD FRONT BY FRIDAY MORNING WHICH MEANS WE/LL DRY OUT FRIDAY LEADING TO SUNNY WEATHER SATURDAY AND SUNDAY. THE NEXT SIGNIFICANT WEATHER WILL BE A SOUTHERN STREAM LOW THAT MOVES NORTHEAST FROM TEXAS LATE SUNDAY NIGHT AND MONDAY. THE GULF LOOKS TO BE WIDE OPEN SO MOISTURE AVAILABILITY SHOULDN/T BE A PROBLEM ESPECIALLY GIVEN THE 60+ KT LLJ. THIS LOOKS MOSTLY LIKE A RAIN EVENT AS INSTABILITY APPEARS LIMITED. TEMPS IN THE MID 50S FRIDAY WILL WARM TO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 745 AM EDT TUE APR 7 2015 RADAR SHOWS LIGHT SHOWERS INCREASING OVER SOUTHWEST LOWER MICHGIAN. SHOWERS WILL REMAIN IN THE VICINITY OF THE TAF SITES THIS MORNING BUT LIKELY WON/T RESTRICT VISIBILITIES. NORTHEAST WINDS HAVE ADVECTED IFR/MVFR CIGS FROM SAGINAW BAY INTO LANSING AND JACKSON. IT/S POSSIBLE THAT WE/LL SEE THESE CIGS BOUNCE AROUND A BIT...AS LANSING HAS JUST SCATTERED OUT. IFR CIGS SHOULD BE A THREAT UNTIL WINDS VEER MORE TO THE EAST RATHER THAN NORTHEAST AND TAKE THE LAKE OUT OF PLAY. && .MARINE... ISSUED AT 329 AM EDT TUE APR 7 2015 WE WILL BE LEAVING THE SMALL CRAFT ADVISORY AS IS WITH THIS FCST PACKAGE. A FAIRLY STIFF E/NE GRADIENT WILL REMAIN IN PLACE THROUGH TODAY AND INTO WED MORNING. WAVES WILL NOT BE TOO SIGNIFICANT ON THIS SIDE OF THE LAKE WITH THE OFFSHORE COMPONENT. && .HYDROLOGY... ISSUED AT 221 PM EDT MON APR 6 2015 RIVERS AND STREAMS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY SLOWLY FALLING...BUT RISES IN RIVER LEVELS DUE TO RAINFALL ARE EXPECTED LATER THIS WEEK. 1 TO 2 INCHES OF WIDESPREAD RAINFALL IS POSSIBLE OVER THE NEXT 7 DAYS...WITH THE POTENTIAL FOR SEVERAL INCHES IF THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED WEDNESDAY NIGHT INTO FRIDAY. STRONGER STORMS ARE CERTAINLY POSSIBLE DURING THIS TIMEFRAME...SO THERE IS A RISK FOR LOCALLY HEAVY RAINFALL. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...99 AVIATION...04 HYDROLOGY...EBW MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
737 AM EDT TUE APR 7 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE APR 7 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS. HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS RDG AND THE TROF ALONG THE W COAST. MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI. TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S. TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT... ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM EDT TUE APR 7 2015 THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE. TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING. THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW SLIGHT CHANCE POPS FOR THE DRIZZLE. ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH 900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS FREEZING RAIN THREAT IN THE HWO. AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME. AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE) WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST. WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER THE NEXT SEVERAL SHIFTS. THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 736 AM EDT TUE APR 7 2015 STEADY ENE WIND ON THE SRN FLANK OF HI PRES RIDGE EXTENDING ACROSS NW ONTARIO WILL ADVECT LLVL DRY AIR INTO UPR MI THRU THIS EVNG... RESULTING IN VFR CONDITIONS DESPITE CONSIDERABLE MID/HI CLDS. AS A DISTURBANCE MOVES INTO THE GREAT LKS TNGT...SOME LIGHT PCPN MAY IMPACT IWD AND SAW OVERNGT. IF THE LLVL DRY AIR CAN BE OVERCOME... MVFR CONDITIONS MAY IMPACT SAW AND ESPECIALLY IWD...WHICH WL BE FARTHER FM THE CORE OF THE DRY AIR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 AM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EDT TUE APR 7 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM EDT TUE APR 7 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR MI UNDER A CONFLUENT WNW FLOW ALOFT BTWN ARCTIC BRANCH CLOSED LO OVER NRN QUEBEC AND SRN BRANCH RDG IN THE PLAINS DOWNSTREAM OF TROF ALONG THE W COAST. UPR MI REMAINS IN THE RRQ OF 130KT H3 JET MAX WITHIN THE CONFLUENCE ZN OF THESE TWO BRANCHES. WV IMAGERY AND RUC ANALYSIS ALSO INDICATE A SHRTWV OVER NDAKOTA THAT IS SLIDING TO THE E. THE DPVA/MID LVL QVECTOR CNVGC AHEAD OF THIS SHRTWV AND SOME UPR DVGC/MID LVL FGEN IN THE RRQ OF THE UPR JET ARE AIDING A LINE OF LIGHT SN/MIXED PCPN ACRS NCENTRAL WI INTO FAR SRN MNM COUNTY WELL TO THE N OF FAIRLY SHARP H85 WARM FNT ORIENTED W-E ACRS THE LOWER LKS. HOWEVER...THE NNE LLVL FLOW OF VERY DRY AIR SHOWN ON THE 00Z INL RAOB TO THE S OF HI PRES STRETCHING FM NEAR LK WINNIPEG ACROSS NW ONTARIO AND INTO QUEBEC IS PREVENTING THIS PCPN FM MOVING FARTHER TO THE N. BUT THERE ARE PLENTY OF MID/HI CLDS OVER THE CWA...THICKEST OVER THE SRN TIER. LOOKING FARTHER UPSTREAM...ANOTHER SHRTWV IS LIFTING TOWARD THE NRN PLAINS IN THE SW FLOW ALOFT BTWN THE PLAINS RDG AND THE TROF ALONG THE W COAST. MAIN FCST CONCERNS THRU TNGT WL BE POPS ALONG THE WI BORDER EARLY THIS FCST PERIOD IN ASSOCIATION WITH THE SHRTWV NOW APRCH MN. FOCUS FOR TNGT WL BE ON IMPACT OF SECOND DISTURBANCE APRCHG THE NRN PLAINS AND ANOTHER DISTURBANCE THE MODELS SHOW WL MOVE THRU WI. TDAY...FIRST SHRTWV OVER NW MN IS FCT TO DRIFT TO THE E AND INTO RRQ OF UPR STREAK TO THE E...ACCOMPANIED BY AN AREA OF DEEP LYR QVECTOR CNVGC. ALTHOUGH THIS SETUP WOULD NORMALLY SUPPORT WDSPRD PCPN...ALL THE MODELS SHOW A STEADY FEED OF SFC-H85 DRY AIR FM THE NE THRU THE DAY. IN FACT...AFTER LINGERING PCPN ENDS EARLY THIS MRNG OVER FAR SRN MENOMINEE COUNTY...ALL OF THE MODELS SHOW NO PCPN OVER UPR MI THRU 00Z THIS EVNG. BUT WITH CONSIDERABLE MID/HI CLD ABOVE THE LLVL DRY AIR AND AN ENE WIND OFF THE CHILLY LK WATERS...MAX TEMPS THIS AFTN SHOULD RUN BLO NORMAL. EXPECT READINGS TO REACH THE LO 40S AWAY FM THE LKS...WHERE TEMPS WL HOLD IN THE 30S. TNGT...AS THE CONFLUENCE ZN SHIFTS SLOWLY TO THE NE TDAY...SHRTWV NOW TRACKING INTO THE NRN PLAINS IS FCST TO LIFT NE INTO SCENTRAL CANADA...WITH BULK OF DEEP LYR QVECTOR CNVGC PASSING TO THE NW. BUT GENERAL MODEL CONSENSUS ALSO HINTS ANOTHER SHRTWV EMERGING FM THE WRN TROF AND THRU THE PLAINS TDAY WL DRIFT INTO WI LATE TNGT... ACCOMPANIED BY AREA OF FAIRLY SHARP UPR DVGC EVEN AS THE MAIN UPR JET CORE TO THE E SLIPS FARTHER AWAY ALONG WITH THE UPR CONFLUENCE ZN. MOST OF THE MODELS FOCUS SOMEWHAT HIER QPF OVER THE SCNTRL CWA...CLOSER TO WHERE THE CORE OF UPR DVGC/AXIS OF SHARPEST MID LVL FGEN TO THE N OF H85 WARM FNT THAT IS FCST TO LIFT NWD WITH THE APRCH OF THIS DISTURBANCE. DESPITE THE GENERAL AGREEMENT ON THESE FEATURES...MODEL QPF AND FCST THERMAL FIELDS ARE QUITE VARIABLE. THE GFS IS WETTEST OVERALL...SHOWING AS MUCH AS 0.25-0.35 INCH OVER THE SCNTRL CLOSER TO THE SHARPER FORCING/FGEN AND WHERE THIS MODEL SHOWS H7 SPECIFIC HUMIDITY IN THE 3-4 G/KG RANGE. BUT MANY OF THE HIER RES MODELS...LIKE THE 00Z NAM AND REGIONAL CNDN...SHOW LTL IF ANY PCPN EVEN THERE. GIVEN PERSISTENCE OF LLVL DRY AIR OVER THE NE CWA AND THE WEAKENING OF THE FORCING WITH TIME AS THE DISTURBANCE LIFTS TO THE NE...WL TEND TO KEEP THE NE CWA DRIER LONGER. PTYPE WL BE A CONCERN...AND MODEL DIFFERENCES COMPOUND THE UNCERTAINTY. SINCE THE GFS SHOWS MORE VERTICAL MOTION/QPF AND THUS MORE DYNAMIC/EVAPORATIVE COOLING...THAT MODEL FCST SDNGS INDICATE A MAINLY SN EVENT...WITH SN AMOUNTS OVER THE SCENTRAL AT LEAST APRCHG ADVY CRITERIA. CONSIDERING THE WIDE DIFFERENCES IN QPF/IMPACT OF LINGERING DRY AIR...DID NOT CONSIDER AN ADVY ATTM EVEN THOUGH TRACK OF DISTURBANCE TO THE S AND VERY DRY NATURE OF THE ANTECEDENT AIRMASS WOULD FAVOR MAINLY SN. MANY OF THE OTHER MODELS SHOW AN ELEVATED WARM LYR WITH MAX TEMPS ALOFT OVER 0C. WITH LLVL DRY AIR THAT WL ALLOW FOR MORE NEAR SFC COOLING...FREEZING RA AND PERHAPS SLEET...ESPECIALLY NEAR THE ONSET OF THE PCPN WHEN THE LLVLS ARE DRIER AND WBLB TEMPS LO ENUF TO ALLOW FOR A BETTER CHC FOR THE DROPS TO FREEZE INTO ICE PELLETS...ARE POSSIBLE. SO RETAINED A MENTION OF THESE PTYPES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM EDT TUE APR 7 2015 THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE. TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING. THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW SLIGHT CHANCE POPS FOR THE DRIZZLE. ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH 900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS FREEZING RAIN THREAT IN THE HWO. AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME. AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE) WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST. WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER THE NEXT SEVERAL SHIFTS. THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 120 AM EDT TUE APR 7 2015 HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE CONSIDERABLE MID/HI CLDS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 AM EDT TUE APR 7 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HI PRES THAT WILL MOVE ACROSS NW ONTARIO INTO QUEBEC THRU WED AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT THIS MORNING INTO THIS EVENING. E TO NE WINDS...MOSTLY 10-20KT...WILL THEN CONTINUE ON WED AND ON INTO THU AS LO PRES LIFTS NE FROM THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THIS TIME...NO GALES APPEAR LIKELY. BUT WINDS WILL BACK TO THE N AND THEN NW UP TO 25 KTS THU NIGHT INTO FRI ONCE THE LO SHIFTS TO THE E. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 429 PM EDT MON APR 6 2015(TODAY AND TONIGHT) WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CONFLUENT WESTERLY FLOW ACROSS THE UPPER LAKES BTWN NRN BRANCH TROF OVER ERN CANADA AND SRN BRANCH RIDGE OVER THE CNTRL CONUS WHICH IS DOWNSTREAM OF A STRONG TROF ALONG/JUST OFF THE W COAST. SNOW THAT AFFECTED MUCH OF SRN UPPER MI LAST NIGHT/EARLIER TODAY HAS LARGELY ENDED AS SUBTLE SHORTWAVE/STRONGER RIGHT ENTRANCE FORCING FROM UPPER JET ALONG AND LOW/MID LEVEL FRONTOGENESIS HAVE SHIFTED E. TO THE N...A DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES RIDGING FROM SASKATCHEWAN/MANITOBA INTO NRN ONTARIO/NRN LAKE SUPERIOR CONTINUES TO FEED TO THE S AND W. RIGHT ENTRANCE OF THE UPPER JET WITHIN THE CONFLUENCE ZONE REMAINS OVER THE UPPER MISSISSIPPI VALLEY/UPPER LAKES REGION TONIGHT. THERE ARE SOME HINTS THAT ANOTHER SUBTLE SHORTWAVE AND RIBBON OF FRONTOGENESIS WILL STREAK ACROSS FAR SCNTRL UPPER MI THIS EVENING. THIS MAY LEAD TO ANOTHER BAND OF SNOW STREAKING ACROSS MAINLY MENOMINEE COUNTY. LATEST RAP/HRRR SUPPORT THIS IDEA AS DO THE 12Z NAM AND HIRES WRF-ARW/NMM TO VARYING DEGREES. RADAR TRENDS UPSTREAM LEND SOME SUPPORT AS WELL. WILL SHOW AN UPTICK IN POPS ACROSS THE SRN HALF OF MENOMINEE COUNTY THIS EVENING WITH SNOW ACCUMULATIONS PROBABLY LESS THAN 1 INCH. EXPECT A SHARP CUTOFF TO THE SNOW FARTHER N AS DRIER AIR FROM THE HIGH PRES RIDGE TO THE N AND NE CONTINUES TO ADVECT S AND W. WILL CARRY SCHC POPS AS FAR N AS US-2 FROM IRON RIVER TO ESCANABA. SNOW WILL END OVERNIGHT. EXPECT MIN TEMPS IN THE 20S ACROSS THE AREA...THOUGH SOME TEENS ARE POSSIBLE IN THE USUAL COLDER SPOTS ACROSS THE N AND E AS CLOUDS MAY THIN ENOUGH TO AID COOLING OVERNIGHT. QUIET DAY EXPECTED ON TUE AS ALL MODEL GUIDANCE IS IN GOOD AGREEMENT ON DRY AIR DOMINATING IN THE LOWER LEVELS. FAVORED THE LOWER SIDE OF GUIDANCE FOR TEMPS WITH THE IDEA THAT FAIRLY THICK HIGHER CLOUDS WILL PREVENT SIGNIFICANT WARMING. E TO NE WIND ALSO ARGUES FOR THE COOLER SIDE OF GUIDANCE...ESPECIALLY SO FROM THE KEWEENAW ACROSS THE NCNTRL AND S OF KESC NEAR LAKE MI. LOW TO MID 30S SHOULD BE THE RULE IN THOSE AREAS. ELSEWHERE...TEMPS SHOULD RISE TO AROUND 40F... HIGHEST WHERE E TO NE WINDS DOWNSLOPE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM EDT TUE APR 7 2015 THE SECOND HALF OF THE WORK WEEK CONTINUES TO LOOK ACTIVE WITH PERIODS OF MIXED PRECIPITATION...BEFORE TRENDING DRIER WITH NORMAL TO ABOVE NORMAL TEMPERATURES THIS WEEKEND. ANOTHER UPPER TROUGH WILL AFFECT THE REGION FOR THE START OF NEXT WEEK...BUT AT THIS POINT...THERMAL PROFILES SUPPORT RAIN FOR THE PRECIP TYPE. TO START THE LONG TERM PERIOD...THE SHORTWAVE THAT WILL BE PRODUCING PRECIPITATION OVER PARTS OF THE UPPER GREAT LAKES REGION WILL BE QUICKLY SHIFTING EAST OUT OF THE THE AREA WEDNESDAY MORNING. THIS MAY LEAD TO SOME LINGERING SHOWERS TO DURING THE MORNING AND WITH THE DEEP MOISTURE DEPARTING IT WILL LEAD TO A WINTRY MIX IF PRECIPITATION OCCURS. WHILE THE LARGE SCALE SUPPORT DEPARTS AT THE START OF THE PERIOD...THE HIGH PRESSURE RIDGE WILL ALSO QUICKLY LEAVE THE REGION AND ALLOW FOR PLENTY OF CLOUDS TO REMAIN OVER THE U.P. FOR WEDNESDAY. THE LATEST TRENDS IN THE MODELS IS FOR LOW LEVEL MOISTURE TO REMAIN OVER THE AREA...AND WITH SOUTHEASTERLY 950-925MB FLOW DEVELOPING THROUGH THE DAY...EXPECT THERE TO BE SOME UPSLOPE DRIZZLE FOR THE HIGHER TERRAIN OF CENTRAL UPPER MICHIGAN. THE GFS CONTINUES TO HIGHLIGHT EVEN MEASURABLE DRIZZLE BUT WITH MUCH OF THE OTHER MODELS SHOWING DRY NEAR SURFACE AIR...WILL ONLY SHOW SLIGHT CHANCE POPS FOR THE DRIZZLE. ATTENTION THEN TURNS TO THE UPPER TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS WEDNESDAY NIGHT AND PHASING WITH A WAVE MOVING THROUGH CANADA THURSDAY AFTERNOON INTO THURSDAY NIGHT AS IT MOVES THROUGH THE UPPER GREAT LAKES REGION. THERE CONTINUES TO BE TWO WAVES OF PRECIPITATION EXPECTED WITH THIS SYSTEM. THE FIRST WILL BE TIED TO THE STRONG WARM AIR ADVECTION AND LEADING SHORTWAVE LIFTING NORTHEAST THROUGH THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. MODEL CONSENSUS HAS THE BEST SHORTWAVE ENERGY MISSING THE U.P. TO THE SOUTHEAST BUT THEY DIFFER ON WHERE THE FOCUS OF THE BEST WARM AIR ADVECTION WILL BE OVER THE U.P. THUS...CONFIDENCE REMAINS LOW ON THE TRACK OF THE HEAVIEST PRECIPITATION (0.15-0.3IN OF LIQUID...HIGHEST OVER THE SOUTH CENTRAL). AS FOR PRECIP TYPE...WITH 900-800MB TEMPERATURES WELL ABOVE FREEZING WITHIN THAT BEST FORCING...WOULD EXPECT THE PRECIPITATION TO FALL AS RAIN. WHICH LEAVES THE SURFACE TEMPERATURES TO DETERMINE WHETHER IT IS FREEZING RAIN OR NOT. ONE POSITIVE WITH THE WARMER WEATHER OVER THE LAST COUPLE OF WEEKS IS THAT IT HAS HELPED WARM THE SURFACE TEMPERATURES ACROSS THE AREA. TODAY...EVEN WITH THE COOLER TEMPERATURES...ROAD SURFACE TEMPERATURES WERE IN THE MID-UPPER 30S. THUS...WITH THE CLOUDS ON WEDNESDAY INTO WEDNESDAY NIGHT HELPING TO INSULATE AND KEEP LOWS AROUND 30 DEGREES (TRENDED THEM UP A COUPLE DEGREES)...THE IMPACT OF THE FREEZING RAIN MAY BE A LITTLE LESS (ESPECIALLY IF ROADS ARE TREATED IN ADVANCE). WILL CONTINUE TO ADDRESS THIS FREEZING RAIN THREAT IN THE HWO. AFTER A BRIEF LULL IN THE STRONGER PRECIPITATION ON THURSDAY AFTERNOON...THE UPPER TROUGH WILL LIFT NORTHEAST THROUGH THE UPPER GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY MORNING WHILE THE SURFACE LOW TRACKS FROM CENTRAL IOWA AT 18Z THURSDAY TO NORTHERN LAKE HURON AT 18Z ON FRIDAY. VERY CONFIDENT ON PRECIPITATION OCCURRING DURING THAT PERIOD...BUT CONFIDENCE IS LACKING ON THE AMOUNTS/LOCATION DUE TO DIFFERENCES WITH THE TRACK/INTENSITY OF THE LOW AND THE MID LEVEL FGEN BAND. THIS IS ALL TIED TO THE PHASING OF THE TWO WAVES...WHICH IS NOTORIOUSLY DIFFICULT FOR MODELS TO PIN DOWN AT THIS STAGE. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS (LEANING TOWARDS GFS/ECMWF) BOTH FOR QPF AND THERMAL FIELDS AS THAT SEEMS TO REPRESENT THE POSSIBILITIES THE BEST AT THIS TIME. AT THIS POINT...THINK THE GEM/NAM SEEM LIKE THE OUTLIERS WITH THE FARTHER NORTHWEST TRACK (ALONG LAKE MICHIGAN AND THE U.P. SHORELINE) WITH THE 12Z ECMWF AND 00Z GFS ENSEMBLE MEMBERS SUPPORTING A TRACK MORE THROUGH NORTHERN LOWER MICHIGAN. THE LATE ARRIVING 00Z ECMWF REMAINS MUCH WEAKER THAN THE OTHER SOLUTIONS...AS IT HAS TRENDED TOWARDS LESS PHASING AND MORE OF A GLANCING BLOW BY THE NORTHERN STREAM WAVE. IF THAT VERIFIES...IT WOULD LEAD TO MUCH LESS PRECIPITATION FOR THE AREA FOR THE THURSDAY NIGHT PERIOD AND DRY BY FRIDAY AFTERNOON. EXPECT THE PRECIP TO START AS RAIN INITIALLY AND THEN GRADUALLY TRANSITION TO OR MIX WITH SNOW FROM WEST TO EAST. WITH ALL OF THE UNCERTAINTY...DON/T WANT TO GET TOO HUNG UP IN SNOWFALL AMOUNTS...BUT THERE COULD BE SLUSHY ACCUMULATIONS WEST OF A LINE FROM MARQUETTE TO CRYSTAL FALLS. THIS SECOND WAVE OF PRECIP IS STILL AN EVOLVING SITUATION THAT WILL NEED TO BE FINE TUNED OVER THE NEXT SEVERAL SHIFTS. THE UPPER TROUGH AND SURFACE LOW WILL QUICKLY DEPART FRIDAY NIGHT AND BRING A QUICK DRYING TREND TO THE AREA AS A SURFACE RIDGE MOVES EAST OVER THE AREA BY SATURDAY MORNING. WITH LIMITED COLD AIR BEHIND THIS SYSTEM AND AN UPPER RIDGE MOVING INTO THE UPPER GREAT LAKES REGION...SHOULD SEE NEAR NORMAL TEMPERATURES ON SATURDAY WITH MOSTLY SUNNY SKIES. THAT UPPER/SURFACE RIDGE WILL SHIFT EAST ON SATURDAY NIGHT...LEADING TO SOUTHWESTERLY WINDS BRINGING WARMER AIR TO THE AREA FOR SUNDAY AND HAVE HIGHS RISING INTO THE UPPER 50S OVER THE WEST AND AROUND 50 OVER THE EAST. THAT SOUTHWESTERLY FLOW WILL BE OUT AHEAD OF THE NEXT UPPER TROUGH THAT WILL BE MOVING ACROSS THE CANADIAN ROCKIES THIS WEEKEND AND IMPACTING THE AREA SUNDAY NIGHT INTO THE FIRST PART OF NEXT WEEK. AT THIS POINT...THE THERMAL PROFILES WOULD SUPPORT RAIN FOR MONDAY AND WILL SHOW INCREASING POPS SUNDAY NIGHT AND CONTINUE CHANCE POPS INTO MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 120 AM EDT TUE APR 7 2015 HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE CONSIDERABLE MID/HI CLDS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 429 PM EDT MON APR 6 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE ACROSS NRN ONTARIO INTO QUEBEC THRU WED MORNING AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT LATER TONIGHT AND CONTINUE THRU TUE NIGHT. EXPECT SOME GALE FORCE GUSTS TUE AFTN/EVENING. E TO NE WINDS...MOSTLY 15-25KT...WILL THEN CONTINUE THRU WED AND ON INTO THU AS LOW PRESSURE LIFTS NE FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION. AT THIS TIME...IT DOES NOT APPEAR THAT THE LOW WILL BE STRONG ENOUGH TO RESULT IN GALES AS IT APPROACHES AND THEN DEPARTS. WINDS WILL BACK AROUND TO THE N AND NW THU NIGHT AND FRI AS THE LOW EXITS TO THE NE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 429 PM EDT MON APR 6 2015(TODAY AND TONIGHT) WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CONFLUENT WESTERLY FLOW ACROSS THE UPPER LAKES BTWN NRN BRANCH TROF OVER ERN CANADA AND SRN BRANCH RIDGE OVER THE CNTRL CONUS WHICH IS DOWNSTREAM OF A STRONG TROF ALONG/JUST OFF THE W COAST. SNOW THAT AFFECTED MUCH OF SRN UPPER MI LAST NIGHT/EARLIER TODAY HAS LARGELY ENDED AS SUBTLE SHORTWAVE/STRONGER RIGHT ENTRANCE FORCING FROM UPPER JET ALONG AND LOW/MID LEVEL FRONTOGENESIS HAVE SHIFTED E. TO THE N...A DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES RIDGING FROM SASKATCHEWAN/MANITOBA INTO NRN ONTARIO/NRN LAKE SUPERIOR CONTINUES TO FEED TO THE S AND W. RIGHT ENTRANCE OF THE UPPER JET WITHIN THE CONFLUENCE ZONE REMAINS OVER THE UPPER MISSISSIPPI VALLEY/UPPER LAKES REGION TONIGHT. THERE ARE SOME HINTS THAT ANOTHER SUBTLE SHORTWAVE AND RIBBON OF FRONTOGENESIS WILL STREAK ACROSS FAR SCNTRL UPPER MI THIS EVENING. THIS MAY LEAD TO ANOTHER BAND OF SNOW STREAKING ACROSS MAINLY MENOMINEE COUNTY. LATEST RAP/HRRR SUPPORT THIS IDEA AS DO THE 12Z NAM AND HIRES WRF-ARW/NMM TO VARYING DEGREES. RADAR TRENDS UPSTREAM LEND SOME SUPPORT AS WELL. WILL SHOW AN UPTICK IN POPS ACROSS THE SRN HALF OF MENOMINEE COUNTY THIS EVENING WITH SNOW ACCUMULATIONS PROBABLY LESS THAN 1 INCH. EXPECT A SHARP CUTOFF TO THE SNOW FARTHER N AS DRIER AIR FROM THE HIGH PRES RIDGE TO THE N AND NE CONTINUES TO ADVECT S AND W. WILL CARRY SCHC POPS AS FAR N AS US-2 FROM IRON RIVER TO ESCANABA. SNOW WILL END OVERNIGHT. EXPECT MIN TEMPS IN THE 20S ACROSS THE AREA...THOUGH SOME TEENS ARE POSSIBLE IN THE USUAL COLDER SPOTS ACROSS THE N AND E AS CLOUDS MAY THIN ENOUGH TO AID COOLING OVERNIGHT. QUIET DAY EXPECTED ON TUE AS ALL MODEL GUIDANCE IS IN GOOD AGREEMENT ON DRY AIR DOMINATING IN THE LOWER LEVELS. FAVORED THE LOWER SIDE OF GUIDANCE FOR TEMPS WITH THE IDEA THAT FAIRLY THICK HIGHER CLOUDS WILL PREVENT SIGNIFICANT WARMING. E TO NE WIND ALSO ARGUES FOR THE COOLER SIDE OF GUIDANCE...ESPECIALLY SO FROM THE KEWEENAW ACROSS THE NCNTRL AND S OF KESC NEAR LAKE MI. LOW TO MID 30S SHOULD BE THE RULE IN THOSE AREAS. ELSEWHERE...TEMPS SHOULD RISE TO AROUND 40F... HIGHEST WHERE E TO NE WINDS DOWNSLOPE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 356 PM EDT MON APR 6 2015 THE LONG TERM FORECAST CONTINUES TO BE A CONTINUALLY FRUSTRATING EXPERIENCE WHEN ATTEMPTING TO PIN DOWN THE FINER DETAILS OF THE FORECAST. ESPECIALLY WITH THE UPPER GREAT LAKES REGION ON THE NORTHERN EDGE OF THE DISTURBANCES AND HAVING THERMAL PROFILES THAT SUPPORT MIXED PRECIPITATION AND FREEZING RAIN. TUE NIGHT INTO WED MORNING A SHORTWAVE LOOKS TO MOVE S OF THE AREA OR OVER THE SRN CWA. STILL LOTS OF UNCERTAINTY WITH TRACK OF THE SHORTWAVE...LOCATION AND AMOUNT OF QPF...AND TEMPERATURE PROFILES. THEREFORE...PRECIP AMOUNT AND TYPE ARE VERY MUCH IN QUESTION AS WELL. IF THE COLDER GFS/ECMWF SOLUTION VERIFY...ANY PRECIP THAT FALLS WOULD BE MORE SNOW TRANSITIONING TO FREEZING DRIZZLE AS MID LEVEL MOISTURE CUTS OUT AND E WINDS FORCE ONSHORE/UPSLOPE PRECIP INTO SCENTRAL UPPER MI. THE WARMER ALOFT NAM AND GEM WOULD RESULT IN MORE FREEZING RAIN TURNING TO FREEZING DRIZZLE. THIS BEING SAID...THE SNOW OR RAIN PORTION IS STILL QUITE UNCERTAIN. FREEZING DRIZZLE WED MORNING SHOULD BE LIGHT AS LOW LEVEL MIXING SHOULD ALLOW NEAR SFC LAYERS TO DRY OUT SOME. WED AFTERNOON/EVENING LOOKS DRY INLAND...BUT COULD SEE DRIZZLE IN UPSLOPE AREAS FROM THE E WINDS...MAINLY CENTRAL UPPER MI AND THE KEWEENAW. A STRONGER SHORTWAVE AND SFC LOW WILL EJECT OUT OF THE CENTRAL PLAINS WED NIGHT...BRINGING A SURGE OF WARM AIR OVER THE CWA. MODELS DO NOT AGREE WELL ON THE FINER DETAILS AND DO NOT HAVE GOOD RUN TO RUN CONTINUITY. MAIN CONCERN EARLY IN THE EVENT IS WITH FREEZING RAIN POTENTIAL WED NIGHT INTO THU MORNING. MID LEVEL TEMPS WILL EASILY SUPPORT ALL LIQUID PRECIP...WITH SFC TEMPS DETERMINING FREEZING RAIN POTENTIAL AS LOW LEVEL COLD AIR WILL BE TOO SHALLOW FOR SLEET. FREEZING RAIN DOES LOOK LIKE A STRONG POSSIBILITY DURING THIS TIME...BUT AMOUNTS OF QPF ARE STILL VERY MUCH IN QUESTION. IT LOOKS AS THOUGH THE SYSTEM WILL PHASE WITH A NRN STREAM SYSTEM LATER THU INTO FRI...BRINGING COLDER AIR IN FROM THE WNW LATE THU INTO FRI. THIS FORECAST PERIOD IS EVEN MORE IN QUESTION AS MODELS STRUGGLE WITH PHASING. IT DOES APPEAR PRECIP IS LIKELY...THE UNCERTAINTY HAS MORE TO DO WITH PTYPE AND PRECIP AMOUNTS...FOR WHICH SMALLER SCALE DETAILS WILL BE CRUCIAL. GIVEN THE GENERAL CONSENSUS IDEA...THINK THAT PRECIP WILL TRANSITION FROM RAIN TO FREEZING RAIN TO SNOW OVER WRN UPPER MI THU EVENING/NIGHT...WITH SIGNIFICANT AMOUNTS OF EACH POSSIBLE BUT NOT CERTAIN. RAIN SHOULD TRANSITION TO MORE OF A RAIN/SNOW MIX OVER THE CENTRAL THU NIGHT. THE ECMWF MOVES THE PRECIP OUT OF THE AREA FRI EVENING WHILE THE GFS LINGERS PRECIP INTO SAT MORNING. GIVEN POTENTIAL FOR FREEZING RAIN ACCUMULATION WED NIGHT/THU MORNING AND FREEZING RAIN/SNOW POTENTIAL THU EVENING/NIGHT WILL CONTINUE TO HIGHLIGHT IN THE HWO. IT LOOKS LIKE SFC HIGH PRESSURE AND UPPER RIDGING SHIFT ACROSS THE CWA OVER THE WEEKEND...WITH A WARM UP POSSIBLE AS THE HIGH SHIFTS E AND A TROUGH MOVES TOWARD THE AREA FROM THE W. WILL JUST RUN WITH A CONSENSU OF GUIDANCE FOR SAT-MON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 120 AM EDT TUE APR 7 2015 HIGH PRES RIDGE EXTENDING ACROSS NRN ONTARIO WILL ADVECT LOW-LEVEL DRY AIR S AND W ACROSS UPPER MI THROUGH THIS EVNG. AS A RESULT...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW DURING THIS TIME DESPITE CONSIDERABLE MID/HI CLDS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 429 PM EDT MON APR 6 2015 WITH LAKE SUPERIOR SITUATED BETWEEN HIGH PRES THAT WILL MOVE ACROSS NRN ONTARIO INTO QUEBEC THRU WED MORNING AND A WARM FRONT THAT WILL REMAIN TO THE S AND SW ACROSS THE PLAINS TO OHIO VALLEY...E TO NE WINDS WILL PERSIST. TYPICAL FOR E TO NE WINDS...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR...IN PARTICULAR BTWN THE APOSTLE ISLANDS AND MN NSHORE WHERE FUNNELING/COASTAL CONVERGENCE ENHANCE THE WINDS. IN THAT AREA...15-25KT WINDS WILL INCREASE TO 20-30KT LATER TONIGHT AND CONTINUE THRU TUE NIGHT. EXPECT SOME GALE FORCE GUSTS TUE AFTN/EVENING. E TO NE WINDS...MOSTLY 15-25KT...WILL THEN CONTINUE THRU WED AND ON INTO THU AS LOW PRESSURE LIFTS NE FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION. AT THIS TIME...IT DOES NOT APPEAR THAT THE LOW WILL BE STRONG ENOUGH TO RESULT IN GALES AS IT APPROACHES AND THEN DEPARTS. WINDS WILL BACK AROUND TO THE N AND NW THU NIGHT AND FRI AS THE LOW EXITS TO THE NE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
337 PM CDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 330 PM CDT TUE APR 7 2015 CURRENT CONDITIONS SYNOPSIS... CLUSTER OF SHOWERS AND EMBEDDED THUNDERSTORMS CURRENTLY MOVING THROUGH THE SOUTHERN PORTION OF THE AREA ALONG THE NORTHERN PERIPHERY OF THE INSTABILITY... WITH A NOTABLE GRADIENT IN MUCAPE JUMPING FROM 0 TO 500 J/KG SOUTH OF THE BORDER. DEEP LAYER SHEAR IS STRONG... AND ONE STORM DID BRIEFLY SHOW SOME MID-LEVEL ROTATION... AND MANAGED TO PRODUCE MARGINALLY SEVERE HAIL. THE ACTIVITY SHOULD TRANSLATE EAST AND FOCUS MORE SOUTH AS THE SHORTWAVE EVIDENT ON WATER VAPOR NEAR THE NEBRASKA/IOWA BORDERS SHIFTS EAST THROUGH EARLY EVENING. FORECAST ITEM/S/ OF CONCERN... CHANCES FOR PCPN... SOME THUNDER... AND PERHAPS SOME MIXED PCPN INTO TONIGHT... WITH THINGS DRYING OUT WEDNESDAY. MODEL DISCUSSION/PREFERENCES... PRIMARILY RELYING ON CAM GUIDANCE... PARTICULARLY HRRR AND HOPWRF MEMBERS... WHICH HAVE A DECENT HANDLE ON CURRENT CONVECTIVE ACTIVITY ACROSS THE AREA... BLENDING MORE TOWARD NAM/GFS SOLUTIONS ON WEDNESDAY. SENSIBLE WEATHER EXPECTATIONS... EXPECT SHRA AND EMBEDDED TSRA TO IMPACT THE SOUTHERN PORTION OF THE AREA INTO PERHAPS THE EARLY EVENING... OTHERWISE WILL SEE PCPN ON THE NORTH SIDE OF SURFACE LOW MOVE EAST ACROSS THE AREA THROUGH THE REMAINDER OF THE EVENING. SOME SLEET COULD MIX IN AT TIMES OVER THE NORTH AND NORTHEAST PORTION OF THE AREA WHERE THE WARM LAYER IS A BIT LESS DEEP. SHOULD SEE ENOUGH DRYING/SUBSIDENCE IN THE MID-LEVELS FOR PCPN TO COME TO AN END LATER TONIGHT... WITH DRY WEATHER OTHER THAN PERHAPS SOME PATCHY DRIZZLE THROUGH MOST OF WEDNESDAY. SOME SHRA COULD WORK BACK INTO THE SOUTHERN PART OF THE AREA BY LATER WEDNESDAY AS THE NEXT SHORTWAVE AND SURFACE IMPULSE ALONG THE BAROCLINIC ZONE WORK INTO THE REGION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 PM CDT TUE APR 7 2015 THE STORM SYSTEM OFF THE COAST OF CALIFORNIA WILL IMPACT OUR REGION FROM WEDNESDAY NIGHT THRU EARLY FRIDAY MORNING. THE FIRST PART OF THE STORM HAS THE POTENTIAL OF SVR WX IN THE FAR SE BASED ON STABILITY PARAMETERS...LOW FREEZING LEVEL AND MID LEVEL LAPSE RATES. THE BEST POTENTIAL WILL BE THURSDAY AFTERNOON FROM ALBERT LEA...NORTHEAST TO EAU CLAIRE WISCONSIN. SEE THE LATEST SPC DAY 3 OUTLOOK. SEVERAL FACTORS NEED TO COME TOGETHER FOR SNOWFALL TO ACCUMULATE IN OUR CWA. FIRST...THE BEST CHC OF PRECIPITATION AND HIGHER PRECIPITATION RATES OCCUR BETWEEN 18Z THU TO 06Z FRIDAY. THE SFC LOW REMAINS IN A FAVORABLE TRACK FOR THE PRECIPITATION TO CHANGE OVER TO SNOW DURING THE LATE AFTN/EVENING. HOWEVER...THERMAL PROFILERS REMAINED UNFAVORABLE OF THIS CHANGE OVER IN OUR CWA...WITH ONLY A SMALL AREA OF THICKNESS VALUES DROPPING TO CRITICAL LEVELS IN EC MN/WC WI THURSDAY EVENING. THERE REMAINS A VERY STRONG SIGNAL OF A TROWAL AND DEFORMATION ZONE DEVELOPMENT IN EC MN/WC WI THURSDAY EVENING. AS WITH PREVIOUS DISCUSSIONS...THERE IS A POTENTIAL OF HEAVY SNOWFALL IN A SMALL BAND IF ALL THE WEATHER ELEMENTS COME TOGETHER. IN ADDITION...A CROSS SECTION OF THE ATMOSPHERE FROM WC MN TO SOUTHERN WI HAS EC MN IN FAVORABLE AREA OF CONVECTIVE STABILITY INDEX /CSI/ AND SLATEWISE CONVECTIVE. THEREFORE...IT IS HIGHLY PROBABLE FOR SOMEWHERE IN EASTERN MN/WESTERN WI TO SEE A HEAVY SNOWFALL EVENT THURSDAY EVENING IF THIS TYPE OF SCENARIO DEVELOPS. PAST THURSDAY...A COOL PERIOD WILL OCCUR FROM FRIDAY THRU SATURDAY BEFORE SOUTHERLY FLOW BEGINS. LATE IN THE WEEKEND AND INTO NEXT WEEK REMAIN VERY UNSETTLED AS ANOTHER STORM SYSTEM BEGINS TO DEVELOP ACROSS THE CENTRAL U.S. WITH THIS TYPE OF PATTERN...TEMPS MAY FLUCTUATE RAPIDLY BASED ON THE AMOUNT CLOUD COVER AND PRECIPITATION POTENTIAL...BUT AN OVERALL MEAN IS TO CONTINUE WITH SLIGHTLY BLW NORMAL TEMPS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 330 PM CDT TUE APR 7 2015 HIGH CONFIDENCE OF WIDESPREAD RAINFALL ACROSS THE SE MPX FORECAST AREA...WITH CIGS LOWERING THROUGHOUT THE NIGHT INTO THE IFR RANGE. SOME IMPROVEMENT IS LIKELY WEDNESDAY AFTN BEFORE THE NEXT WAVE OF PRECIPITATION DEVELOPS. EXPECT AN EAST TO EAST-SOUTHEAST WIND AROUND 10-15 KTS TONIGHT...BACKING TO THE E-NE BY WEDNESDAY AFTN. KMSP...HIGH CONFIDENCE OF -SHRA LATE THIS AFTN/EARLY EVENING WITH CIGS LOWERING. CIGS WILL LIKELY DROP TO IFR OVERNIGHT...AND SLOWLY RISE WEDNESDAY AFTN. EXPECT AN EAST TO EAST-SOUTHEAST WIND AROUND 10-15 KTS TONIGHT...BACKING TO THE E-NE BY WEDNESDAY AFTN. /OUTLOOK FOR KMSP/ THU...MVFR POSSIBLY IFR. RA/SN LIKELY. WINDS N 15-25 KTS. FRI...VFR. WINDS NW 10-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM... LONG TERM...JLT AVIATION...JLT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
818 PM CDT WED APR 8 2015 .UPDATE...A FEW SHOWERS HAVE CROPPED UP THIS EVENING BELOW THE CAP OVER SW MS/EC LA JUST AS THE HRRR HAS INDICATED. IT IS ALSO INDICATING THAT THEY WILL NOT LAST LONG...DIMINISHING BEFORE MIDNIGHT. LOOKING AT HOURLY TEMPS/DEWPOINTS...TWEAKED THESE A BIT SIMILAR TO THE HRRR SOLUTION WHICH SHOWED A GOOD SURGE OF LOW LEVEL MOISTURE AND CLOUD COVER AFTER MIDNIGHT. THIS SHOULD RESULT IN MINS NOT QUITE AS COOL./26/ && .AVIATION...VFR CIGS THIS EVENING WILL TRANSITION TO MVFR/IFR AFTER MIDNIGHT AS LOW CLOUDS ONCE AGAIN OVERSPREAD THE AREA. WINDS REMAINING FROM 5 TO 15 KNOTS WILL LIMIT FOG FORMATION OVER MUCH OF THE AREA. THE EXCEPTION WILL BE NEAR MEI AND HBG WHERE THE WIND WILL SUBSIDE ENOUGH FOR IFR/LIFR VSBYS FROM 10-14Z. AFTER 14Z...CIGS WILL BECOME MVFR AND EVENTUALLY VFR AFTER 18Z./26/ && .PREV DISCUSSION... /ISSUED 417 PM CDT WED APR 8 2015/ DISCUSSION...ANOTHER WARM DAY HAS TAKEN PLACE TODAY AS TEMPERATURES HAVE REACHED INTO THE 80S AREAWIDE...AND SOME LOCATIONS HAVE SEEN THE MID 80S. GUSTY SOUTHERLY WINDS CONTINUE TO BRING MOISTURE INTO THE REGION. CLOUDS WILL CONTINUE TO BE ON THE INCREASE THROUGH TONIGHT AND INTO THURSDAY. SOME PATCHY FOG WILL BE POSSIBLE IN THE EAST AND SOUTHEAST BUT OVERALL WIND SPEEDS SHOULD BE UP ENOUGH TO PRECLUDE TOO MUCH FOG AND MORE IN THE WAY OF STRATUS. THURSDAY SHOULD BE ANOTHER WARM DAY AS MOISTURE CONTINUES TO MOVE INTO THE REGION AHEAD OF A DEVELOPING STORM SYSTEM IN THE PLAINS. SHOWERS SHOULD BE KEPT AT BAY TOMORROW AS THE REGION WILL REMAIN CAPPED AND HEIGHTS WILL BE HIGH. A 998MB SFC LOW WILL TRACK NORTHEAST ACROSS THE MIDWEST INTO SOUTHERN WISCONSIN THROUGH THE DAY THURSDAY. THIS WILL BRING A FRONT TOWARD THE REGION. BY LATER IN THE DAY...FORCING SHOULD ERODE THE CAP AND COULD ALLOW FOR A FEW SHOWERS AND STORMS TO DEVELOP. HI-RES MODEL GUIDANCE IS NOT VERY AGGRESSIVE WITH THIS UNTIL THE LATER INTO THE EVENING WHEN A SQUALL LINE WILL MOVE THROUGH THE REGION WITH THE FRONT LOSING SOME STEAM. WITH VERTICAL TOTALS NEARING 30C AND SUFFICIENT LOW AND DEEP LAYER SHEAR...WE COULD SEE SOME SEVERE STORMS PARTICULARLY IN THE DELTA REGION LATER TOMORROW AFTERNOON INTO THE EVENING HOURS. THE PRIMARY RISK WITH THESE WOULD BE FROM HAIL AND WIND. PW VALUES WILL BE RATHER HIGH...AROUND 1.8-1.9 INCHES...AND THIS ALONG WITH POTENTIAL FOR TRAINING STORMS COULD POSE A HEAVY RAIN/FLOODING RISK. WILL CONTINUE TO MENTION ALL OF THESE HAZARDS IN THE HWO AND GRAPHICS. AS THE FRONT OOZES SOUTH THROUGH THE REGION ON FRIDAY...THE POTENTIAL FOR SEVERE STORMS WILL BE LOWER BUT NOT ZERO AS INSTABILITY WILL REMAIN GOOD. WILL CONTINUE WITH THIS IN THE HWO/GRAPHICS AS WELL. BEHIND THE FRONT...CLEARING CONDITIONS WILL OCCUR AS A 1025MB SFC HIGH WILL SURGE INTO THE REGION. THE FRONT WILL STALL ALONG THE SOUTHERN PORTIONS OF MY CWA OR JUST TO THE SOUTH OF IT. THIS WILL HELP BRING SOME SHOWERS AND STORMS TO THE REGION THROUGH THE WEEKEND AS THE AIRMASS WILL REMAIN MOIST AT LEAST FOR THE SOUTHERN PORTIONS OF THE AREA. THE NORTHERN PORTIONS COULD DRY OUT A LITTLE WITH SOME MIDLEVEL DRYING IN PLACE. THE FRONT WILL RETURN NORTH AS A WARM FRONT LATER IN THE WEEKEND AS THE SFC HIGH SHIFTS OFF TOWARD THE EAST COAST. ANOTHER MORE NOTABLE SYSTEM LOOKS TO TAKE PLACE TO OUR WEST OVER THE TEXAS PANHANDLE COME MONDAY. THIS WILL INCREASE MOISTURE AND SHOWER ACTIVITY OVER OUR REGION TUESDAY. THE SYSTEM LOOKS TO GET INGESTED INTO THE UPPER PATTERN AS IT MOVES OFF TO THE NORTHEAST. THAT BEING SAID...MODELS CONTINUE TO SHOW RAIN IN OUR REGION AS THE SOUTHWEST UPPER LEVEL FLOW BRINGS MOISTURE AND DISTURBANCES THROUGH. /28/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 67 83 68 77 / 9 18 47 77 MERIDIAN 67 82 67 78 / 7 16 27 77 VICKSBURG 70 84 67 77 / 16 23 63 72 HATTIESBURG 66 84 69 81 / 9 16 16 77 NATCHEZ 69 83 68 78 / 16 20 38 74 GREENVILLE 69 81 64 71 / 11 33 82 42 GREENWOOD 69 82 64 74 / 10 19 81 55 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CDT Mon Apr 6 2015 .UPDATE: Issued at 901 PM CDT Mon Apr 6 2015 Weak, scattered convection just east of 3LF will shift east of the forecast area later this evening, while another area of scattered, slightly stronger convection around UUV will move eastward into portions of southwestern IL later this evening. A persistent and localized area of fog continues in the FAM area this evening. Still a lot of uncertainty with regards to additional convection for late tonight into Tuesday morning. The latest operational models have most of their QPF across southeast MO and southwest IL, mainly just southeast of our forecast area. Some of the high resolution, explicit models develop more organized convection, potentially an MCS in a region of strong low level warm air advection on the nose of a southwesterly low level jet which moves east-southeastward into northeast or central MO towards morning along and just north of a developing surface warm front. This convection should be elevated and may produce hail. The 00Z Tuesday TOP sounding indicated a capped atmosphere which may hinder much convective development across much of eastern KS and western MO. For now will continue with the going forecast of pops increasing into the chance catagory for our entire forecast area late tonight. Unseasonably warm conditions, about 15 to 20 degrees above normal can be expected tonight due to low level cloud cover, south-southeasterly surface winds, low level warm air advection, and high surface dewpoints. Temperatures in portions of the forecast area will remain nearly steady through the night. GKS && .SHORT TERM: (Through Late Tonight) Issued at 344 PM CDT Mon Apr 6 2015 Low pressure over the Great Plains continues to push a warm and moist airmass into the region. Guidance suggests that convection will blossom after 06-08Z somewhere over the CWFA as the nose of a 35-40kt low level jet runs into the 850mb baroclinic zone which is draped over the area. Resulting isentropic lift should produce an area of convection late tonight. This is all good in theory, however short range guidance including the NAM and RAP show a decent inversion above the level of free convection on forecast soundings at various locations and times across the area. This puts significant doubt on timing and coverage of convection late tonight. Current feeling is that the best chance for storms to develop will be 08Z or later, and possibly near the I-70 corridor in Missouri. Ample pre-storm MUCAPE in excess of 1500-2000 J/kg and persistent LLJ/isentropic lift should allow storms to increase in coverage through 12Z. Also, with that kind of instability available and forecast deep layer shear around 40kts, could see some storms produce large hail. Only the uncertainty of where the storms will form and ultimate areal coverage has dissuaded me from going with likely or higher PoPs. As it stands, have 40-50% across the entire CWFA late tonight, as this should allow the evening shift to monitor latest trends and adjust as necessary. Carney .LONG TERM: (Tuesday through Next Monday) Issued at 344 PM CDT Mon Apr 6 2015 Main forecast concern continues to be precipitation chances. Obviously, threat of convection will be very high by Thursday and Thursday night as deep upper level trof and associated surface features push into the mid Mississippi Valley...the primary problem is trying to pin down spatial and temporal convective trends from tomorrow morning until the widespread and stormy weather that is expected by Thursday. The elevated storms that do develop late tonight should wind down during the morning, leaving unstable but capped AMS blanketing the area from Tuesday afternoon into Wednesday morning. Current forecast soundings would suggest that southward sagging frontal boundary will not be enough to bust through the warm mid level temps, but there also seems to be some hints of very weak shortwave energy ejecting into the area from the upper trof to our west that could produce more elevated activity. In truth I can probably dream up 2 or 3 scenarios on how convection could evolve during this time, but with so much uncertainty for now plan on sticking with going forecast trends, which generally indicate low chance PoPs over most of the CWA during this time frame. Fine-tuning will have to wait until this time period gets a bit closer and specifics (hopefully) become clearer. In spite of the considerable abiguity in precip trends heading into mid week, today`s model guidance as well as that over the past several days continue to point to widespread convection as we head into Wednesday night and Thursday, with storms continuing into at least Thursday evening. Intensifying surface low over the central Plains on Wednesday afternoon will lead to increasing WAA advection and isentropic ascent north of the frontal boundary. This low level level forcing should then punch through the mid- level cap which should begin to weaken by this time as heights begin to fall in advance of the upper level trof. This round of convection will work east as the synoptic front pushes north of the area, placing the entire CWA in the warm sector of the surface cyclone by Thursday morning. More convection should develop during the day either from additional shortwave energy or perhaps the effects of any residual boundaries from Wednesday night`s activity, with a final shot of convection occurring along the cold front as we head into the evening hours. The synoptic models have backed off some on the instability forecast, perhaps due to extensive cloudiness in the low levels as well as a weakening of the nearly dry adiabtic lapse rates in the EML that are progged early on during the forecast cycle. However, kinematic and synoptic fields still strongly suggest a severe weather threat...or more likely several episodes of severe weather...from Wednesday night into Thursday evening. As alluded to in the day3 and day 4 SPC discussions, threat of large hail and damaging winds looks fairly substantial, while specific tornado threat will at least be partially predicated on the specific locations of fronts and any residual boundaries. Uncertain how to handle the passage of the cold front/end of thunderstorm threat. Initial thought was to slow it down a bit as a common model bias is to be too fast with strong upper level systems, but on the other hand convection along the front will likely be screaming to the east, so effective bounday may race ahead of the actual front. So, will continue thunderstorm threat across the entire CWA on Thursday night, but will go dry by Friday. It appears that this dry weather will continue into Saturday, with thunderstorm chances returning by Sunday and Monday. In spite of the fact that there will be considerable cloudiness, there should be plenty of warmth through Thursday, with highs primarily ranging from the middle 70s to lower 80s. The exception to this may be over our northern counties on Wednesday, where southward drift of the cold front will back off temps into the upper 60s and lower 70s. Arrival of the cold air will mean more seasonable temps by Friday and Saturday. Truett && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1153 PM CDT Mon Apr 6 2015 Showers and thunderstorms developed in warm sector this evening and remain just out of TAF sites. For now cigs will be the main issue varying between VFR, MVFR and IFR. As warm front lifts north through region, cigs to lower down to IFR between 07z and 09z Tuesday. Models now holding off precip for TAF sites til closer to daybreak, after 11z Tuesday, as complex develops over central MO and slides east along I-70 corridor, before diminishing by mid morning. Then front to lift north allowing cigs to lift and thin out a bit. As for winds, to remain southeast to south for sites along I-70 corridor while KUIN will see southeast winds back to the east as front moves closer, then eventually veer back to the south as front lifts north of KUIN. Specifics for KSTL: Showers and thunderstorms developed in warm sector this evening and remain just south of metro area TAFs. For now cigs will be the main issue varying between VFR, MVFR and IFR. As warm front lifts north through region, cigs to lower down to IFR by 07z Tuesday. Models now holding off precip for STL til closer to daybreak, after 12z Tuesday, as complex develops over central MO and slides east along I-70 corridor, before diminishing by 15z Tuesday. Then front to lift north allowing cigs to lift and thin out a bit. As for winds, to remain southeast to south. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
943 PM MDT WED APR 8 2015 .UPDATE... ONE FINAL UPDATE. HAVE CANCELLED THE WINTER WX ADVISORY FOR OUR PORTION OF THE BIGHORN MOUNTAINS AS DRIER AIR IS WORKING IN FROM THE NORTH AND PCPN HAS BECOME MUCH LIGHTER. ANY ADDITIONAL ACCUMS WILL BE MINIMAL...BUT SOME SNOTELS DID PICK UP AT LEAST 6-7 INCHES OF SNOW SINCE EARLY AFTERNOON. JKL PREVIOUS DISCUSSION ISSUED 751 PM... PRECIPITATION MAINLY IN THE FORM OF SNOW IN OUR FAR EAST...A RESULT OF MID LEVEL FRONTOGENESIS AND UPPER JET DIVERGENCE...IS BECOMING LIGHTER AND MOVING TO THE EAST. WE HAVE HAD SEVERAL REPORTS OF BETWEEN A HALF AND THREE- QUARTERS OF AN INCH OF PCPN ALONG AND EAST OF A MIZPAH TO BROADUS LINE. AS FOR SNOWFALL...THE WINNER TO THIS POINT IS A SIX INCH REPORT FROM PLEVNA. WILL SUSTAIN HIGH POPS IN OUR EAST THROUGH 03Z THEN TAPER THEM OFF QUICKLY...WITH EXPECTATION OF MOST PCPN BEING DONE BY MIDNIGHT. IN THE WEST...AREA OF SHOWERS EMBEDDED IN NORTHEASTERLY MID LEVEL FLOW WAS A RESULT OF SLIGHTLY NEGATIVE LIFTED INDICES...BUT THIS ACTIVITY IS FIZZLING OUT AS WE APPROACH SUNSET. WILL DRY OUT OUR WEST BY MIDNIGHT BASED ON THESE TRENDS...AS ANY ACTIVITY ASSOCIATED W/ WEAK LOW OVER THE PAC NW SHOULD REMAIN TO OUR WEST. OTHER POTENTIAL ISSUE IS FOG TONIGHT GIVEN THE RECENT PCPN ALONG WITH DECREASING CLOUDS AND WINDS THROUGH THE NIGHT. HRRR IS STARTING TO HINT AT FOG IN OUR EAST AFTER MIDNIGHT. WOULD ALSO NOT BE SURPRISED TO SEE AT LEAST LOCALIZED FOG IN OUR WEST AND CENTRAL PARTS EVEN W/O THE PCPN TODAY...GIVEN DEWPTS AROUND 30F WHICH SFC TEMPS SHOULD FALL TO OR SLIGHTLY BELOW TONIGHT. HAVE ADDED MENTION OF PATCHY FOG ACROSS MOST OF OUR CWA FROM 06Z TONIGHT TO 15Z TOMORROW MORNING. HAVE ALSO TWEAKED EXPECTED LOW TEMPS DOWN A BIT. JKL && .SHORT TERM...VALID FOR THU AND FRI... THROUGH THE MORNING...MOST OF THE ACTIVITY WAS TO EAST OF THE AREA INTO NORTH DAKOTA AND BARELY GETTING INTO BAKER. THE MODELS WERE BEING TOO AGGRESSIVE WITH GENERATING PRECIP IN SOUTHEAST MONTANA. THE SREF MEANS AT SHERIDAN AND MILES CITY HAS BEEN TRENDING DOWNWARDS WITH THE PRECIP AMOUNTS. THAT BEING SAID...THE MODELS CONTINUE TO SHOW THE PRECIP WILL BE INCREASING THIS EVENING. THE RADAR IS GIVING CREDENCE TO THIS TREND...AS COVERAGE AND INTENSITY HAS BEEN INCREASING. HAVE NOT MADE TOO MANY CHANGE TO THE FORECAST FOR TONIGHT. HAVE TRENDED SNOW AMOUNTS DOWN SLIGHTLY...GENERALLY 1 TO 2 INCHES ACROSS THE SOUTHEASTERN ZONES...WHILE ANOTHER 2 TO 5 INCHES IN THE BIGHORNS. THE ADVISORY REMAINS IN PLACE. GOING INTO TOMORROW AND FRIDAY...THE LOW THAT AFFECTED THE AREA TODAY WILL MOVE OFF INTO THE CENTRAL PLAINS AND PRECIP CHANCES ACROSS THE AREA WILL BE OUT OF THE AREA BY EARLY AFTERNOON TOMORROW....AT THE LATEST. A RIDGE WILL DEVELOP OVER THE NORTHERN ROCKIES...BUT WILL QUICKLY MOVE WEST DURING THE DAY ON FRIDAY. AS THE RIDGE MOVES OUT...A WEAK WAVE WILL MOVE THROUGH...BUT OUTSIDE OF THE SOUTHWEST MOUNTAINS...FRIDAY LOOKS TO BE DRY. TEMPS WILL BE WARMING THROUGH THE REMAINDER OF THE WEEK...WITH 50S FOR THURSDAY AND INTO THE 60S ON FRIDAY. REIMER .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... ALL EYES ON MEDIUM RANGE GUIDANCE TOWARD THE END OF THE EXTENDED (MIDDLE PART OF NEXT WEEK) WHEN A POTENT UPPER LOW IS FORECAST TO MOVE INTO THE NORTHERN ROCKIES. UNTIL THEN...WEATHER FAIRLY QUIET BUT MAY NEED TO MONITOR FIRE WEATHER AGAIN OVER THE WEEKEND. NEXT SHORT WAVE AND ASSOCIATED COLD FRONT WILL PUSH ACROSS THE REGION SATURDAY NIGHT. PREFRONTAL ENVIRONMENT ON SATURDAY SHOULD RESULT IN OUR WARMEST DAY OF THE EXTENDED WITH TEMPERATURES BACK TO NEAR 70 WITH FRONTAL PASSAGE SATURDAY NIGHT. SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING WIDESPREAD. DRY WITH GUSTY NORTHWEST WINDS BEHIND THE SYSTEM FOR SUNDAY. THESE DAYS WILL HAVE TO BE MONITORED FOR ANY FIRE WEATHER CONCERNS DEPENDING ON HOW ARE FUELS ARE LOOKING. BUT WINDS WILL BE GUSTY AND HUMIDITIES BACK INTO THE TEENS. SIGNIFICANT TROUGHING DEVELOPS ALONG THE WEST COAST MONDAY BEFORE SHIFTING EAST INTO THE NORTHERN ROCKIES BY THE MIDDLE OF NEXT WEEK. MODELS ALL INDICATING A SIGNIFICANT STORM WITH HEAVIER PRECIPITATION POSSIBLE...BUT PATH OF SYSTEM OFFERING LARGE UNCERTAINTIES. FOR NOW...HAVE CONTINUED WITH FAIRLY HIGH PRECIP CHANCES OUT 7 AND 8 DAYS. TEMPERATURES WILL HAVE TO BE MONITORED CLOSELY DEPENDING ON THE PATH OF THIS SYSTEM. STAY TUNED. FRIEDERS && .AVIATION... RAIN AND SNOW WILL CONTINUE ALONG AND EAST OF A KSHR-KBHK LINE THROUGH THE REMAINDER OF THE EVENING. THE PRECIP WILL SLOWLY TAPER OFF AFTER 06Z BUT LINGERING SHOWERS WILL CONTINUE FOR THOSE AREAS. EXPECT MVFR-IFR CONDITIONS IN THE RAIN AND SNOW WITH IMPROVING CONDITIONS AFTER 06Z. ELSEWHERE...PARTLY CLOUDY SKIES ALONG WITH AN ISOLATED SHOWER CAN BE EXPECTED WITH VFR CONDITIONS PREVAILING. THE MOUNTAINS WILL BE OBSCURED THROUGHOUT THE NIGHT. HOOLEY && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 030/057 035/063 040/069 040/061 033/064 039/063 038/056 10/B 01/B 01/N 31/N 11/B 33/W 45/W LVM 025/054 033/059 037/063 034/056 030/059 035/060 034/051 21/B 12/W 12/W 31/N 12/W 33/W 55/W HDN 028/058 031/066 035/071 038/062 031/066 036/066 034/058 10/B 01/B 01/B 31/N 11/B 23/W 45/W MLS 028/056 032/065 037/070 039/061 032/065 038/062 038/057 10/B 00/U 01/U 31/N 11/B 23/W 45/W 4BQ 028/052 029/063 035/070 038/060 031/066 037/064 036/058 20/B 00/B 01/U 21/B 11/B 33/W 45/W BHK 027/054 028/063 033/068 037/059 030/064 036/064 035/059 30/B 00/U 11/U 21/N 11/B 22/W 45/W SHR 026/051 027/060 033/066 036/058 031/064 035/063 034/054 30/B 01/B 01/B 31/B 11/B 33/W 45/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
751 PM MDT WED APR 8 2015 .UPDATE... PRECIPITATION MAINLY IN THE FORM OF SNOW IN OUR FAR EAST...A RESULT OF MID LEVEL FRONTOGENESIS AND UPPER JET DIVERGENCE...IS BECOMING LIGHTER AND MOVING TO THE EAST. WE HAVE HAD SEVERAL REPORTS OF BETWEEN A HALF AND THREE-QUARTERS OF AN INCH OF PCPN ALONG AND EAST OF A MIZPAH TO BROADUS LINE. AS FOR SNOWFALL...THE WINNER TO THIS POINT IS A SIX INCH REPORT FROM PLEVNA. WILL SUSTAIN HIGH POPS IN OUR EAST THROUGH 03Z THEN TAPER THEM OFF QUICKLY...WITH EXPECTATION OF MOST PCPN BEING DONE BY MIDNIGHT. IN THE WEST...AREA OF SHOWERS EMBEDDED IN NORTHEASTERLY MID LEVEL FLOW WAS A RESULT OF SLIGHTLY NEGATIVE LIFTED INDICES...BUT THIS ACTIVITY IS FIZZLING OUT AS WE APPROACH SUNSET. WILL DRY OUT OUR WEST BY MIDNIGHT BASED ON THESE TRENDS...AS ANY ACTIVITY ASSOCIATED W/ WEAK LOW OVER THE PAC NW SHOULD REMAIN TO OUR WEST. OTHER POTENTIAL ISSUE IS FOG TONIGHT GIVEN THE RECENT PCPN ALONG WITH DECREASING CLOUDS AND WINDS THROUGH THE NIGHT. HRRR IS STARTING TO HINT AT FOG IN OUR EAST AFTER MIDNIGHT. WOULD ALSO NOT BE SURPRISED TO SEE AT LEAST LOCALIZED FOG IN OUR WEST AND CENTRAL PARTS EVEN W/O THE PCPN TODAY...GIVEN DEWPTS AROUND 30F WHICH SFC TEMPS SHOULD FALL TO OR SLIGHTLY BELOW TONIGHT. HAVE ADDED MENTION OF PATCHY FOG ACROSS MOST OF OUR CWA FROM 06Z TONIGHT TO 15Z TOMORROW MORNING. HAVE ALSO TWEAKED EXPECTED LOW TEMPS DOWN A BIT. JKL && .SHORT TERM...VALID FOR THU AND FRI... THROUGH THE MORNING...MOST OF THE ACTIVITY WAS TO EAST OF THE AREA INTO NORTH DAKOTA AND BARELY GETTING INTO BAKER. THE MODELS WERE BEING TOO AGGRESSIVE WITH GENERATING PRECIP IN SOUTHEAST MONTANA. THE SREF MEANS AT SHERIDAN AND MILES CITY HAS BEEN TRENDING DOWNWARDS WITH THE PRECIP AMOUNTS. THAT BEING SAID...THE MODELS CONTINUE TO SHOW THE PRECIP WILL BE INCREASING THIS EVENING. THE RADAR IS GIVING CREDENCE TO THIS TREND...AS COVERAGE AND INTENSITY HAS BEEN INCREASING. HAVE NOT MADE TOO MANY CHANGE TO THE FORECAST FOR TONIGHT. HAVE TRENDED SNOW AMOUNTS DOWN SLIGHTLY...GENERALLY 1 TO 2 INCHES ACROSS THE SOUTHEASTERN ZONES...WHILE ANOTHER 2 TO 5 INCHES IN THE BIGHORNS. THE ADVISORY REMAINS IN PLACE. GOING INTO TOMORROW AND FRIDAY...THE LOW THAT AFFECTED THE AREA TODAY WILL MOVE OFF INTO THE CENTRAL PLAINS AND PRECIP CHANCES ACROSS THE AREA WILL BE OUT OF THE AREA BY EARLY AFTERNOON TOMORROW....AT THE LATEST. A RIDGE WILL DEVELOP OVER THE NORTHERN ROCKIES...BUT WILL QUICKLY MOVE WEST DURING THE DAY ON FRIDAY. AS THE RIDGE MOVES OUT...A WEAK WAVE WILL MOVE THROUGH...BUT OUTSIDE OF THE SOUTHWEST MOUNTAINS...FRIDAY LOOKS TO BE DRY. TEMPS WILL BE WARMING THROUGH THE REMAINDER OF THE WEEK...WITH 50S FOR THURSDAY AND INTO THE 60S ON FRIDAY. REIMER .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... ALL EYES ON MEDIUM RANGE GUIDANCE TOWARD THE END OF THE EXTENDED (MIDDLE PART OF NEXT WEEK) WHEN A POTENT UPPER LOW IS FORECAST TO MOVE INTO THE NORTHERN ROCKIES. UNTIL THEN...WEATHER FAIRLY QUIET BUT MAY NEED TO MONITOR FIRE WEATHER AGAIN OVER THE WEEKEND. NEXT SHORT WAVE AND ASSOCIATED COLD FRONT WILL PUSH ACROSS THE REGION SATURDAY NIGHT. PREFRONTAL ENVIRONMENT ON SATURDAY SHOULD RESULT IN OUR WARMEST DAY OF THE EXTENDED WITH TEMPERATURES BACK TO NEAR 70 WITH FRONTAL PASSAGE SATURDAY NIGHT. SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING WIDESPREAD. DRY WITH GUSTY NORTHWEST WINDS BEHIND THE SYSTEM FOR SUNDAY. THESE DAYS WILL HAVE TO BE MONITORED FOR ANY FIRE WEATHER CONCERNS DEPENDING ON HOW ARE FUELS ARE LOOKING. BUT WINDS WILL BE GUSTY AND HUMIDITIES BACK INTO THE TEENS. SIGNIFICANT TROUGHING DEVELOPS ALONG THE WEST COAST MONDAY BEFORE SHIFTING EAST INTO THE NORTHERN ROCKIES BY THE MIDDLE OF NEXT WEEK. MODELS ALL INDICATING A SIGNIFICANT STORM WITH HEAVIER PRECIPITATION POSSIBLE...BUT PATH OF SYSTEM OFFERING LARGE UNCERTAINTIES. FOR NOW...HAVE CONTINUED WITH FAIRLY HIGH PRECIP CHANCES OUT 7 AND 8 DAYS. TEMPERATURES WILL HAVE TO BE MONTIRED CLOSELY DEPENDING ON THE PATH OF THIS SYSTEM. STAY TUNED. FRIEDERS && .AVIATION... RAIN AND SNOW WILL CONTINUE ALONG AND EAST OF A KSHR-KBHK LINE THROUGH THE REMAINDER OF THE EVENING. THE PRECIP WILL SLOWLY TAPER OFF AFTER 06Z BUT LINGERING SHOWERS WILL CONTINUE FOR THOSE AREAS. EXPECT MVFR-IFR CONDITIONS IN THE RAIN AND SNOW WITH IMPROVING CONDITIONS AFTER 06Z. ELSEWHERE...PARTLY CLOUDY SKIES ALONG WITH AN ISOLATED SHOWER CAN BE EXPECTED WITH VFR CONDITIONS PREVAILING. THE MOUNTAINS WILL BE OBSCURED THROUGHOUT THE NIGHT. HOOLEY && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 029/057 035/063 040/069 040/061 033/064 039/063 038/056 10/B 01/B 01/N 31/N 11/B 33/W 45/W LVM 025/054 033/059 037/063 034/056 030/059 035/060 034/051 21/B 12/W 12/W 31/N 12/W 33/W 55/W HDN 028/058 031/066 035/071 038/062 031/066 036/066 034/058 10/B 01/B 01/B 31/N 11/B 23/W 45/W MLS 028/056 032/065 037/070 039/061 032/065 038/062 038/057 10/B 00/U 01/U 31/N 11/B 23/W 45/W 4BQ 028/052 029/063 035/070 038/060 031/066 037/064 036/058 90/B 00/B 01/U 21/B 11/B 33/W 45/W BHK 027/054 028/063 033/068 037/059 030/064 036/064 035/059 +0/B 00/U 11/U 21/N 11/B 22/W 45/W SHR 026/051 027/060 033/066 036/058 031/064 035/063 034/054 +0/B 01/B 01/B 31/B 11/B 33/W 45/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT THURSDAY FOR ZONE 98. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
632 PM CDT WED APR 8 2015 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT WED APR 8 2015 PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT AND ALSO SHOWERS ON THURSDAY. SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM 12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO. GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA. OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE COULD ALSO BE SOME LOCALLY HEAVY RAIN. SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY. PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT... MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT. WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 315 PM CDT WED APR 8 2015 WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S. && .AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 629 PM CDT WED APR 8 2015 IFR TO LIFR CONDITIONS WILL CONTINUE THROUGHOUT THE TAF PERIOD AS AN AREA OF LOW PRESSURE SKIRTS TO OUR SOUTHEAST. A FEW SCATTERED SHOWERS AND POSSIBLY THUNDERSTORMS MAY MOVE ACROSS THE TAF SITES OVERNIGHT BUT SHOULD PUSH EAST OF THE AREA BY LATE MORNING. A STRONG COLD FRONT WILL TURN WINDS TO THE NORTHWEST BY THE EARLY AFTERNOON WITH GUSTS UP TO 35KTS POSSIBLE. ANOTHER ROUND OF SHOWERS ARE POSSIBLE BEHIND THIS FRONT THROUGH THE AFTERNOON...ESPECIALLY IN KOFK AND KOMA. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...KERN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
634 AM CDT TUE APR 7 2015 .SYNOPSIS... ISSUED AT 400 AM CDT TUE APR 7 2015 H5 ANALYSIS FROM TONIGHT HAS A CLOSED LOW OVER NRN QUEBEC...WITH A BROAD TROUGH EXTENDING SWD INTO NEW ENGLAND. FURTHER WEST...A SECOND LOW WAS PRESENT OFF THE COAST OF SWRN OREGON WITH A TROUGH EXTENDING SWD TO OFF THE COAST OF CENTRAL CALIFORNIA. AT THE SURFACE...LOW PRESSURE WAS PRESENT OVER NORTHERN COLORADO...WITH A STATIONARY FRONT EXTENDING ESE INTO WESTERN KS...THEN EAST NORTHEAST INTO EAST CENTRAL KS. NORTH OF THIS FEATURE TONIGHT...EASTERLY WINDS AND PLENTY OF LOW LEVEL MOISTURE HAVE PUSHED INTO WESTERN AND NORTH CENTRAL NEBRASKA. IN ADDITION TO AREAS OF FOG...OCCASIONAL DRIZZLE WAS REPORTED AT MOST OBSERVATION STATIONS ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. WITH CLOUDY SKIES PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA...TEMPERATURES RANGED FROM 36 AT VALENTINE TO 50 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGE IS PRECIPITATION CHANCES...ALONG WITH THE THREAT OF FOG AND DRIZZLE. FOR THIS MORNING...LOW POPS WILL CONTINUE DUE TO A COMBINATION OF OCCASIONAL DRIZZLE WHICH WILL BE HEAVY ENOUGH TO MEASURE...AND THE THREAT FOR SHOWERS IN ASSOCIATION WITH A WEAK DISTURBANCE AND MID LEVEL MOISTURE WHICH WILL CROSS THE SANDHILLS AND NORTHERN NEBRASKA THIS MORNING. PRECIPITATION CHANCES WILL COME TO AN END TEMPORARILY THIS AFTERNOON...AS THE BOUNDARY LAYER WARMS AND CIGS LIFT...ALONG WITH MID LEVEL MOISTURE EXITING THE FORECAST AREA TO THE EAST. FOR THE MOST PART...SKIES WILL REMAIN CLOUDY TODAY ACROSS THE FORECAST AREA...AS WE REMAIN UNDER A THICK VEIL OF STRATUS. THE EXCEPTION MAY BE ACROSS THE PANHANDLE COUNTIES...AS THE LATEST HRRR AND NAM DO INDICATE SOME SCATTERING OUT OF CLOUDS DURING PEAK HEATING THIS AFTERNOON. HOWEVER...THE MODELS INDICATED A DECENT AMOUNT OF CLEARING FOR YESTERDAY WITH HEATING...WHICH FOR THE MOST PART...DIDN/T MATERIALIZE. WITH THIS IN MIND...WENT COOLER ON HIGHS TODAY THAN GUIDANCE...HEDGING ON CLOUDS REMAINING ENTRENCHED ACROSS THE FORECAST AREA TODAY. CIGS WILL LOWER THIS EVENING...WITH ANOTHER ROUND OF DRIZZLE AND FOG ACROSS THE FORECAST AREA. FCST SOUNDINGS AND CROSS SECTIONS INDICATE A NEAR SATURATED LAYER FROM THE SFC TO H85 TONIGHT...COLLOCATED WITH WEAK OMEGA IN THIS LAYER AND VERY DRY CONDS ALOFT. DID GO AHEAD AND INCREASE POPS OVERNIGHT AS SOME MID LEVEL MOISTURE LIFTS INTO THE FORECAST AREA FROM THE SOUTHWEST...WHICH MAY LEAD TO LIGHT PRECIPITATION IN ADDITION TO ANY DRIZZLE WHICH IS EXPECTED AS WELL. LOWS TONIGHT WILL BE MILD GIVEN THE CLOUD COVER AND MOIST BOUNDARY LAYER CONDS...WITH READINGS RANGING FROM THE UPPER 30S IN THE FAR NORTH...TO LOWER TO MID 40S IN THE CENTRAL AND SOUTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 400 AM CDT TUE APR 7 2015 FORECAST CONCERNS CONTINUE TO DEAL WITH DRIZZLE/FOG/RAIN CHANCES THROUGH WEDNESDAY WHICH BRING UP THE CONCERN OF TEMPERATURES. THEN FOCUS TURNS TO MAIN UPPER LEVEL SYSTEM MOVING ACROSS THE CENTRAL PLAINS THURSDAY WHICH BRINGS CHANCES FOR RAIN/SNOW AND STRONG WINDS TO THE FORECAST AREA. THE PATTERN THEN REMAINS ACTIVE AS THE LOCAL AREA GETS IMPACTED BY SYSTEMS MOVING THROUGH BOTH THE NORTHERN AND SOUTHERN STREAMS INTO THE FIRST PART OF NEXT WEEK. FORECAST MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE PERIOD...HOWEVER THERE HAVE BEEN SOME RUN TO RUN INCONSISTENCIES WHICH HAS KEPT CONFIDENCE LOWER THAN WOULD BE DESIRED. BEGINNING ON WEDNESDAY...THE PRIMARY UPPER LEVEL LOW WILL MOVE INTO THE CENTRAL ROCKIES WITH A WEAK SHORTWAVE TROUGH EJECTING OUT AHEAD OF THE MAIN SYSTEM DURING THE DAY WEDNESDAY. MODELS CONTINUE TO DEVELOP QPF OVER MUCH OF NEBRASKA ON WEDNESDAY...HOWEVER LOOKING AT MOISTURE PROFILES IN CROSS SECTIONS ACROSS THE AREA AND FORECAST SOUNDINGS...THE MOISTURE REMAINS QUITE SHALLOW...BELOW 750MB. THE LIFT ASSOCIATED WITH THE SHORTWAVE TROUGH DOES HELP PROVIDE LIFT THROUGH THE COLUMN BUT WITH THE AIR ABOVE 750MB BEING SO EXTREMELY DRY...THIS LIFT WILL NOT HAVE ANYTHING TO WORK WITH AND SO WILL HAVE NO IMPACT ON THE FORECAST. IF THERE WOULD BE MOISTURE...COULD ARGUE FOR NEEDING MENTION OF THUNDERSTORMS AS THE LAPSE RATES ARE QUITE STEEP LEADING TO AT LEAST SOME INSTABILITY...BUT AGAIN NO MOISTURE WILL PROHIBIT THE NEED FOR THUNDER MENTION. BACK TO THE LOW LEVELS...THERE IS DECENT LIFT WITHIN THE SATURATED LAYER AND WITH LIGHT EASTERLY WINDS CONTINUING THROUGH WEDNESDAY NIGHT...THE SLIGHT UPSLOPE FLOW WILL HELP KEEP STRATUS/FOG/DRIZZLE POTENTIAL THROUGH THE DAY. WITH THIS EXPECTATION...DON/T THINK TEMPERATURES WILL RISE MUCH THROUGH THE DAY WEDNESDAY AND HAVE LOWERED HIGHS SUBSTANTIALLY. THE FRONT WILL BE JUST SOUTH OF THE FORECAST AREA SO THERE MAY BE A TIGHT GRADIENT WHERE CLOUDS/COLDER TEMPERATURES EXIST TO WHERE THERE IS PLENTIFUL SUNSHINE AND HIGHS UP INTO THE 70S. BELIEVE THAT THIS WILL BE SOUTH OF THE FORECAST AREA THROUGH. THE WHOLE UPPER LEVEL SYSTEM CONTINUES TO MOVE EAST THROUGH THE DAY THURSDAY...AND WHILE THEY ARE IN AGREEMENT WITH THE UPPER LOW PASSING OVER THE REGION AND DUMPING SOME DECENT MOISTURE ACROSS THE FORECAST AREA...THESE SOLUTIONS ARE DIFFERENT FROM PRIOR RUNS AS ALL ARE NOW MOVING THE SYSTEM ACROSS THE AREA AS AN OPEN WAVE AND IN TURNS MOVES IT ACROSS THE AREA FASTER...WITH PRECIPITATION ENDED BY MID-DAY THURSDAY. THEY STILL PRODUCE QUITE A BIT OF QPF ON THE NORTHWEST SIDE OF THE FORECAST AREA DESPITE MOVING ACROSS THE AREA FASTER THAN WAS EARLIER THOUGHT. DID REMOVE MENTION OF THUNDERSTORMS FOR WEDNESDAY NIGHT AND THURSDAY. THE FRONT WILL REMAIN WELL SOUTH AND EAST OF THE LOCAL AREA AS THE SURFACE LOW STAYS ACROSS KANSAS AS IT MOVES EASTWARD. THIS WILL KEEP THE WARMER AIR...PLUS ANY MOISTURE ADVECTION/LIFT ALONG THE FRONT AWAY FROM THE LOCAL AREA. AND...THE LOW LEVEL JET WILL BE WELL TO THE EAST SO REALLY NOT CONCERNED ABOUT THUNDERSTORMS. THEN ON THURSDAY AS THE SURFACE LOW ACROSS KANSAS TRANSITIONS INTO THE MISSISSIPPI RIVER VALLEY THE PRESSURE GRADIENT WILL TIGHTEN...BRINGING STRONG NORTHERLY WINDS TO THE FORECAST AREA. THIS WILL LEAD TO CONDITIONS FEELING QUITE RAW AS APPARENT TEMPERATURES ARE LOOKING TO BE IN THE 20S AND 30S. WITH THE COOLER AIR MOVING IN FROM THE NORTH...IT IS LIKELY THAT THE PRECIPITATION WILL CHANGE OVER TO A RAIN/SNOW MIX AND THEN OVER TO SNOW COMPLETELY OVER PARTS OF THE PANHANDLE. DON/T THINK AMOUNTS WILL BE MUCH...BUT COULD SEE THE GROUND BECOME WHITE FOR A SHORT PERIOD IN PLACES. AGAIN AS THIS IS NOT MOVING THROUGH AS AN OPEN WAVE...IT WILL MOVE THROUGH THE LOCAL AREA QUICKLY AND HAVE ENDED PRECIPITATION CHANCES ABOUT 6 HOURS EARLIER THAN IN THE PRIOR FORECAST. SHORTWAVE RIDGING BUILDS INTO THE CENTRAL PLAINS BRIEFLY FRIDAY NIGHT...WHILE AN UPPER LOW IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHERN CONUS AND NORTHERN MEXICO. MEANWHILE ANOTHER POTENT SYSTEM MOVES INTO THE PACIFIC NORTHWEST. THESE SYSTEMS WILL BOTH PROGRESS EASTWARD AND THERE IS SOME INDICATION THAT THEY MAY ATTEMPT TO INTERACT EARLY NEXT WEEK WHICH COULD BRING ANOTHER WET PERIOD TO THE FORECAST AREA FOR MONDAY AND TUESDAY. CONFIDENCE IS NOT HIGH IN THIS OCCURRING RIGHT NOW SO WILL MAINTAIN LOW END PRECIPITATION CHANCES FOR NOW. ULTIMATELY WITH THE MORE ACTIVE PATTERN...WILL SEE MORE CHANCES FOR PRECIPITATION...AND TEMPERATURES CLOSER TO NORMAL...ALTHOUGH THERE WILL BE DAYS WITH HIGHER TEMPERATURES. HOWEVER THERE ARE NO CURRENT INDICATIONS OF ANOTHER PERIOD OF WELL ABOVE NORMAL TEMPERATURES FOR THE FORECAST AREA AT THIS TIME. AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1142 PM CDT MON APR 6 2015 LIFR CEILINGS CURRENTLY AT THE KLBF AND KVTN TERMINALS IS FORECAST TO PERSIST UNTIL 15Z. VSBY WILL LIKELY RANGE NEAR 1SM -DZ BR AT KVTN WHILE LOWERING TO 3SM -DZ BR AT KLBF. AFTER 15Z...CEILINGS AND VSBYS WILL IMPROVE TO IFR...AND TO MVFR AFTER 18Z. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 635 AM CDT TUE APR 7 2015 OVERCAST SKIES ARE EXPECTED OVER THE NEXT 24 HOURS AT BOTH THE KLBF AND KVTN TERMINALS WITH MVFR AND IFR CIGS TODAY...AND THE THREAT FOR LIFR CIGS TONIGHT. FOR THE KLBF TERMINAL...EXPECT MVFR CIGS TODAY WITH CLOUD DECKS RANGING FROM 1600 TO 2200 FT AGL. SOME CIGS MAY BE AROUND 700 FT AGL THIS MORNING. CIGS WILL FALL TO 600 TO 1200 FT AGL AFTER MID EVENING TONIGHT. FOR THIS MORNING...PERIODS OF DRIZZLE ARE POSSIBLE WITH VISBYS AS LOW AS 3SM. DRIZZLE WILL BE POSSIBLE ONCE AGAIN OVERNIGHT TONIGHT WITH VISBYS DOWN TO 4SM. FOR THE KVTN TERMINAL...EXPECT CIGS RANGING FROM 300 TO 500 FT AGL THIS MORNING. CIGS WILL CLIMB TO AROUND 1300 FT AGL LATER TODAY...FALLING TO 400 TO 700 FT AGL THIS EVENING. DRIZZLE WILL BE POSSIBLE THIS MORNING WITH VISBYS RANGING FROM 1 TO 3SM. DRIZZLE WILL BE POSSIBLE ONCE AGAIN TONIGHT WITH VISBYS AROUND 4SM . && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...BROOKS AVIATION...CLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
401 AM CDT TUE APR 7 2015 .SYNOPSIS... ISSUED AT 400 AM CDT TUE APR 7 2015 H5 ANALYSIS FROM TONIGHT HAS A CLOSED LOW OVER NRN QUEBEC...WITH A BROAD TROUGH EXTENDING SWD INTO NEW ENGLAND. FURTHER WEST...A SECOND LOW WAS PRESENT OFF THE COAST OF SWRN OREGON WITH A TROUGH EXTENDING SWD TO OFF THE COAST OF CENTRAL CALIFORNIA. AT THE SURFACE...LOW PRESSURE WAS PRESENT OVER NORTHERN COLORADO...WITH A STATIONARY FRONT EXTENDING ESE INTO WESTERN KS...THEN EAST NORTHEAST INTO EAST CENTRAL KS. NORTH OF THIS FEATURE TONIGHT...EASTERLY WINDS AND PLENTY OF LOW LEVEL MOISTURE HAVE PUSHED INTO WESTERN AND NORTH CENTRAL NEBRASKA. IN ADDITION TO AREAS OF FOG...OCCASIONAL DRIZZLE WAS REPORTED AT MOST OBSERVATION STATIONS ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. WITH CLOUDY SKIES PRESENT ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA...TEMPERATURES RANGED FROM 36 AT VALENTINE TO 50 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT TUE APR 7 2015 OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGE IS PRECIPITATION CHANCES...ALONG WITH THE THREAT OF FOG AND DRIZZLE. FOR THIS MORNING...LOW POPS WILL CONTINUE DUE TO A COMBINATION OF OCCASIONAL DRIZZLE WHICH WILL BE HEAVY ENOUGH TO MEASURE...AND THE THREAT FOR SHOWERS IN ASSOCIATION WITH A WEAK DISTURBANCE AND MID LEVEL MOISTURE WHICH WILL CROSS THE SANDHILLS AND NORTHERN NEBRASKA THIS MORNING. PRECIPITATION CHANCES WILL COME TO AN END TEMPORARILY THIS AFTERNOON...AS THE BOUNDARY LAYER WARMS AND CIGS LIFT...ALONG WITH MID LEVEL MOISTURE EXITING THE FORECAST AREA TO THE EAST. FOR THE MOST PART...SKIES WILL REMAIN CLOUDY TODAY ACROSS THE FORECAST AREA...AS WE REMAIN UNDER A THICK VEIL OF STRATUS. THE EXCEPTION MAY BE ACROSS THE PANHANDLE COUNTIES...AS THE LATEST HRRR AND NAM DO INDICATE SOME SCATTERING OUT OF CLOUDS DURING PEAK HEATING THIS AFTERNOON. HOWEVER...THE MODELS INDICATED A DECENT AMOUNT OF CLEARING FOR YESTERDAY WITH HEATING...WHICH FOR THE MOST PART...DIDN/T MATERIALIZE. WITH THIS IN MIND...WENT COOLER ON HIGHS TODAY THAN GUIDANCE...HEDGING ON CLOUDS REMAINING ENTRENCHED ACROSS THE FORECAST AREA TODAY. CIGS WILL LOWER THIS EVENING...WITH ANOTHER ROUND OF DRIZZLE AND FOG ACROSS THE FORECAST AREA. FCST SOUNDINGS AND CROSS SECTIONS INDICATE A NEAR SATURATED LAYER FROM THE SFC TO H85 TONIGHT...COLLOCATED WITH WEAK OMEGA IN THIS LAYER AND VERY DRY CONDS ALOFT. DID GO AHEAD AND INCREASE POPS OVERNIGHT AS SOME MID LEVEL MOISTURE LIFTS INTO THE FORECAST AREA FROM THE SOUTHWEST...WHICH MAY LEAD TO LIGHT PRECIPITATION IN ADDITION TO ANY DRIZZLE WHICH IS EXPECTED AS WELL. LOWS TONIGHT WILL BE MILD GIVEN THE CLOUD COVER AND MOIST BOUNDARY LAYER CONDS...WITH READINGS RANGING FROM THE UPPER 30S IN THE FAR NORTH...TO LOWER TO MID 40S IN THE CENTRAL AND SOUTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 400 AM CDT TUE APR 7 2015 FORECAST CONCERNS CONTINUE TO DEAL WITH DRIZZLE/FOG/RAIN CHANCES THROUGH WEDNESDAY WHICH BRING UP THE CONCERN OF TEMPERATURES. THEN FOCUS TURNS TO MAIN UPPER LEVEL SYSTEM MOVING ACROSS THE CENTRAL PLAINS THURSDAY WHICH BRINGS CHANCES FOR RAIN/SNOW AND STRONG WINDS TO THE FORECAST AREA. THE PATTERN THEN REMAINS ACTIVE AS THE LOCAL AREA GETS IMPACTED BY SYSTEMS MOVING THROUGH BOTH THE NORTHERN AND SOUTHERN STREAMS INTO THE FIRST PART OF NEXT WEEK. FORECAST MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE PERIOD...HOWEVER THERE HAVE BEEN SOME RUN TO RUN INCONSISTENCIES WHICH HAS KEPT CONFIDENCE LOWER THAN WOULD BE DESIRED. BEGINNING ON WEDNESDAY...THE PRIMARY UPPER LEVEL LOW WILL MOVE INTO THE CENTRAL ROCKIES WITH A WEAK SHORTWAVE TROUGH EJECTING OUT AHEAD OF THE MAIN SYSTEM DURING THE DAY WEDNESDAY. MODELS CONTINUE TO DEVELOP QPF OVER MUCH OF NEBRASKA ON WEDNESDAY...HOWEVER LOOKING AT MOISTURE PROFILES IN CROSS SECTIONS ACROSS THE AREA AND FORECAST SOUNDINGS...THE MOISTURE REMAINS QUITE SHALLOW...BELOW 750MB. THE LIFT ASSOCIATED WITH THE SHORTWAVE TROUGH DOES HELP PROVIDE LIFT THROUGH THE COLUMN BUT WITH THE AIR ABOVE 750MB BEING SO EXTREMELY DRY...THIS LIFT WILL NOT HAVE ANYTHING TO WORK WITH AND SO WILL HAVE NO IMPACT ON THE FORECAST. IF THERE WOULD BE MOISTURE...COULD ARGUE FOR NEEDING MENTION OF THUNDERSTORMS AS THE LAPSE RATES ARE QUITE STEEP LEADING TO AT LEAST SOME INSTABILITY...BUT AGAIN NO MOISTURE WILL PROHIBIT THE NEED FOR THUNDER MENTION. BACK TO THE LOW LEVELS...THERE IS DECENT LIFT WITHIN THE SATURATED LAYER AND WITH LIGHT EASTERLY WINDS CONTINUING THROUGH WEDNESDAY NIGHT...THE SLIGHT UPSLOPE FLOW WILL HELP KEEP STRATUS/FOG/DRIZZLE POTENTIAL THROUGH THE DAY. WITH THIS EXPECTATION...DON/T THINK TEMPERATURES WILL RISE MUCH THROUGH THE DAY WEDNESDAY AND HAVE LOWERED HIGHS SUBSTANTIALLY. THE FRONT WILL BE JUST SOUTH OF THE FORECAST AREA SO THERE MAY BE A TIGHT GRADIENT WHERE CLOUDS/COLDER TEMPERATURES EXIST TO WHERE THERE IS PLENTIFUL SUNSHINE AND HIGHS UP INTO THE 70S. BELIEVE THAT THIS WILL BE SOUTH OF THE FORECAST AREA THROUGH. THE WHOLE UPPER LEVEL SYSTEM CONTINUES TO MOVE EAST THROUGH THE DAY THURSDAY...AND WHILE THEY ARE IN AGREEMENT WITH THE UPPER LOW PASSING OVER THE REGION AND DUMPING SOME DECENT MOISTURE ACROSS THE FORECAST AREA...THESE SOLUTIONS ARE DIFFERENT FROM PRIOR RUNS AS ALL ARE NOW MOVING THE SYSTEM ACROSS THE AREA AS AN OPEN WAVE AND IN TURNS MOVES IT ACROSS THE AREA FASTER...WITH PRECIPITATION ENDED BY MID-DAY THURSDAY. THEY STILL PRODUCE QUITE A BIT OF QPF ON THE NORTHWEST SIDE OF THE FORECAST AREA DESPITE MOVING ACROSS THE AREA FASTER THAN WAS EARLIER THOUGHT. DID REMOVE MENTION OF THUNDERSTORMS FOR WEDNESDAY NIGHT AND THURSDAY. THE FRONT WILL REMAIN WELL SOUTH AND EAST OF THE LOCAL AREA AS THE SURFACE LOW STAYS ACROSS KANSAS AS IT MOVES EASTWARD. THIS WILL KEEP THE WARMER AIR...PLUS ANY MOISTURE ADVECTION/LIFT ALONG THE FRONT AWAY FROM THE LOCAL AREA. AND...THE LOW LEVEL JET WILL BE WELL TO THE EAST SO REALLY NOT CONCERNED ABOUT THUNDERSTORMS. THEN ON THURSDAY AS THE SURFACE LOW ACROSS KANSAS TRANSITIONS INTO THE MISSISSIPPI RIVER VALLEY THE PRESSURE GRADIENT WILL TIGHTEN...BRINGING STRONG NORTHERLY WINDS TO THE FORECAST AREA. THIS WILL LEAD TO CONDITIONS FEELING QUITE RAW AS APPARENT TEMPERATURES ARE LOOKING TO BE IN THE 20S AND 30S. WITH THE COOLER AIR MOVING IN FROM THE NORTH...IT IS LIKELY THAT THE PRECIPITATION WILL CHANGE OVER TO A RAIN/SNOW MIX AND THEN OVER TO SNOW COMPLETELY OVER PARTS OF THE PANHANDLE. DON/T THINK AMOUNTS WILL BE MUCH...BUT COULD SEE THE GROUND BECOME WHITE FOR A SHORT PERIOD IN PLACES. AGAIN AS THIS IS NOT MOVING THROUGH AS AN OPEN WAVE...IT WILL MOVE THROUGH THE LOCAL AREA QUICKLY AND HAVE ENDED PRECIPITATION CHANCES ABOUT 6 HOURS EARLIER THAN IN THE PRIOR FORECAST. SHORTWAVE RIDGING BUILDS INTO THE CENTRAL PLAINS BRIEFLY FRIDAY NIGHT...WHILE AN UPPER LOW IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHERN CONUS AND NORTHERN MEXICO. MEANWHILE ANOTHER POTENT SYSTEM MOVES INTO THE PACIFIC NORTHWEST. THESE SYSTEMS WILL BOTH PROGRESS EASTWARD AND THERE IS SOME INDICATION THAT THEY MAY ATTEMPT TO INTERACT EARLY NEXT WEEK WHICH COULD BRING ANOTHER WET PERIOD TO THE FORECAST AREA FOR MONDAY AND TUESDAY. CONFIDENCE IS NOT HIGH IN THIS OCCURRING RIGHT NOW SO WILL MAINTAIN LOW END PRECIPITATION CHANCES FOR NOW. ULTIMATELY WITH THE MORE ACTIVE PATTERN...WILL SEE MORE CHANCES FOR PRECIPITATION...AND TEMPERATURES CLOSER TO NORMAL...ALTHOUGH THERE WILL BE DAYS WITH HIGHER TEMPERATURES. HOWEVER THERE ARE NO CURRENT INDICATIONS OF ANOTHER PERIOD OF WELL ABOVE NORMAL TEMPERATURES FOR THE FORECAST AREA AT THIS TIME. AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1142 PM CDT MON APR 6 2015 LIFR CEILINGS CURRENTLY AT THE KLBF AND KVTN TERMINALS IS FORECAST TO PERSIST UNTIL 15Z. VSBY WILL LIKELY RANGE NEAR 1SM -DZ BR AT KVTN WHILE LOWERING TO 3SM -DZ BR AT KLBF. AFTER 15Z...CEILINGS AND VSBYS WILL IMPROVE TO IFR...AND TO MVFR AFTER 18Z. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...BROOKS AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1145 PM CDT MON APR 6 2015 .SHORT TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 330 PM CDT MON APR 6 2015 FORECAST CONCERNS CONTINUE TO BE ON AND OFF PRECIPITATION CHANCES THROUGH THE WEEK...TEMPERATURES...AND SEVERE POTENTIAL. THE LOW CLOUDS MOVED IN OVERNIGHT...WITH SOME FOG AND DRIZZLE. THE 12Z OAX SOUNDING WAS SATURATED TO 890MB/2500FT WITH 0.49PWAT. A FEW STORMS DEVELOPED AROUND BOONE AND ANTELOPE COUNTIES AND LIFTED TOWARD WAYNE...WITH A STRONGER CLUSTER NEAR WASHINGTON AND BURT THAT LIFTED NORTHEAST ACROSS HARRISON...MONONA...AND SHELBY WITH OTHERS IN SOUTHWEST IOWA. THE 12Z H5 MAP SHOWED A WEAK SHORTWAVE WITH THIS FEATURE IN THE SOUTHWEST FLOW ALOFT. THE H5 CLOSED LOW WAS STILL OFF THE WASHINGTON/OREGON COAST WITH A BROAD TROF. THERE WAS A WEAK WAVE IN THE FLOW AT H7 APPROACHING THE LOCAL FORECAST AREA AT 12Z...WITH ANOTHER WEAK WAVE OVER COLORADO AND YET FARTHER SOUTHWEST OVER SOUTHERN CALIFORNIA. THE H85 PATTERN HAD AN H85 LOW NEAR LBF WITH SOUTHWEST FLOW AHEAD OF IT AND A POCKET OF 7C DEWPOINTS. THE 10-12DEG. H85 DEWPOINTS WERE OVER SOUTHERN MO AND ARKANSAS INTO EASTERN OK. THE H7 DEWPOINTS WERE BETTER OVER TN/AL/MS. THE +20 DEG. C H85 TEMPS WERE OVER TX WITH THE THERMAL RIDGE NOSING TOWARD OMA AT +12 DEG C. THE LATEST VISIBLE SATELLITE IMAGERY WAS CLOUDY MOST AREAS...WITH SOME BUMPY CLOUDS NEAR SD INTO IOWA AND A FEW THINNER SPOTS TOWARD FAIRBURY... THE SURFACE FRONT WAS NEAR YANKTON TO ONL WITH A DRYLINE NEAR KGBD KANSAS AND THE WARM FRONT FROM SALINA TO WICHITA WITH THE CLEARING NEAR THERE. TEMPERATURES WERE IN THE 50S TO LOWER 60S WITH 70S AND 80S SOUTH OF THE WARM FRONT.THE LOCAL RADAR WAS MAINLY DRY WITH ECHOES TO THE NORTHEAST INTO IOWA. STILL SOME PATCHY FOG WITH VSBYS 2 TO 4 MILES IN SPOTS. TONIGHT...SURFACE LOW PRESSURE TRIES TO ORGANIZE A LITTLE FARTHER SOUTH IN KANSAS WITH NORTHEAST FLOW PREVAILING ACROSS THE FORECAST AREA. ONE THING TO WATCH WILL BE A 50KT LOW LEVEL JET THAT INCREASES ACROSS KANSAS INTO MISSOURI. THE 4KM WRF HAS A CLUSTER OF STORMS DEVELOPING AND MOVING ACROSS NORTHERN KANSAS AND MISSOURI. THE RAP HAS SHOWERS/TSTORMS IN SOUTHEAST NEBRASKA. IN OUR FORECAST AREA...ANY PRECIPITATION LOOKS SPOTTY. DO HAVE HIGHER POPS IN THE SOUTHEAST AND ALSO IN THE NORTHEAST BY MORNING. THE GFS DOES INCREASE INSTABILITY TOWARD 1000J/KG IN THE SOUTHEAST. ANY STRONGER STORMS COULD PRODUCE SOME HAIL. THERE MAY BE AN ENHANCED BAND OF LIGHT PRECIP IN NORTHEAST NEBRASKA BY MORNING NEAR AN INVERTED TROF AND SOME SHORTWAVE ENERGY PASSES THROUGH. TUESDAY...THE SURFACE LOW PRESSURE TRACKS NORTHEAST TOWARD SOUTHEAST NEBRASKA OR NORTHEAST KANSAS...WITH A H85 CIRCULATION OVER THE FORECAST AREA. THE PRECIPITATION (SHOWERS AND ISOLATED THUNDERSTORMS) SHOULD MOVE ACROSS THE FORECAST AREA DURING THE DAY. TEMPERATURES AGAIN SHOULD BE IN THE 50S...WITH 60S CLOSER TO THE SURFACE LOW FALLS CITY COULD BREAK OUT TO THE LOWER 70S. TUESDAY NIGHT INTO WEDNESDAY NIGHT AHEAD OF THE STRONGER SHORTWAVE...FLOW BACKS AND RE-FOCUSES THE LOW LEVEL FLOW WITH PRECIPITATION CHANCES AGAIN ON THE INCREASE. THE BETTER COVERAGE SHOULD BE THE SOUTHEAST PART OF THE FORECAST AREA. THE DAY 3 SPC OUTLOOK HAS THIS AREA ALSO IN THE SLIGHT RISK AND THIS SEEMS REASONABLE AND WILL BE DEPENDENT ON THE THE SURFACE LOW TRACK. THE NAM/EC IS NOT QUITE AS FAR NORTH AT THE GFS. SO THIS WILL BE SOMETHING TO KEEP AN EYE ON. THE FRONT PUSHES THROUGH THURSDAY WITH THE UPPER LEVEL TROF TO THE WEST. POST-FRONT SHOWERS WILL CONTINUE INTO THURSDAY WITH NORTHWEST WINDS. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 330 PM CDT MON APR 6 2015 THE STORM SYSTEM PULLS AWAY THURSDAY NIGHT. THERE IS A SMALL CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS FRIDAY NIGHT AND SATURDAY. ON AND OFF PRECIPITATION CHANCES CONTINUE INTO THE WEEKEND. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1145 PM CDT MON APR 6 2015 WIDESPREAD IFR/LIFR CIGS AND IFR VSBYS WILL CONTINUE THROUGH ABOUT 18Z AS AREAS OF FOG AND DRIZZLE PERSIST. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN CENTRAL NEBRASKA BEFORE 12Z...THEN SPREAD EAST TOWARD KOFK AND KLNK BY 12Z THEN KOMA BY 14Z. EXPECT ABOUT A 6 HOUR PERIOD OF POTENTIAL SHOWERS AND ISOLATED THUNDERSTORMS. SOME LIGHT IMPROVEMENT IN VSBYS AND CIGS TO MVFR ARE IS POSSIBLE BETWEEN 18Z AND 00Z...THEN DETERIORATING CONDITIONS TO IFR ARE FORECAST AFTER 00Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
205 AM EDT TUE APR 7 2015 .SYNOPSIS... A SLOW MOVING FRONTAL SYSTEM WILL KEEP THE WEATHER UNSETTLED FOR MUCH OF THE UPCOMING WEEK. && .NEAR TERM /THROUGH TODAY/... 945 PM UPDATE... MAIN CHANGE THIS FORECAST RUN WAS TO PULL WAY BACK ON THE POPS DURING THE SECOND HALF OF THE OVERNIGHT AND INTO TUESDAY MORNING. MAIN WAVE OF PRECIP IS MOVING THROUGH THE FA ATTM AND IS PROGGED TO WEAKEN AND DIMINISH AFTER MIDNIGHT. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT TRENDS. WE ARE SLOWLY INGESTING NEW MODEL/MOS DATA AFTER THE AWIPS II INSTALL EARLIER, SO WE ARE A LITTLE LIMITED THIS EVENING ON WHAT DATA WE CAN UTILIZE TO BLEND WITH. 1 PM UPDATE... CLOUDS ARE BEGINNING TO ENCROACH FROM THE WEST ASSOCIATED WITH A SERIES OF SHORTWAVES THAT ARE BEGINNING TO EJECT AND RACE EAST OUT OF THE LARGE SCALE TROUGH OVER THE WESTERN US. THE FIRST SHOWERS REACHING THE GROUND CAN BE SEEN OVER NORTHERN OHIO...AND GUIDANCE SHOWS THE MOISTURE CONTINUING TO SURGE INTO THE REGION ON A STRONG LOW LEVEL SWLY FLOW. GEFS/SREF SHOW PWATS RISING TO 1-2 ST DEV ABOVE NORMAL...CONTINUING INTO AT LEAST TUESDAY. SREF SHOWS INCREASING CHANCES FOR RAIN EARLY TONIGHT...WITH LIKELY TO CATEGORICAL POPS DEVELOPING BETWEEN 21-03Z. GEFS IS A LITTLE LESS AGGRESSIVE BUT STILL SUGGESTS MOST IF NOT ALL LOCATIONS WILL SEE MEASURABLE RAINS OVERNIGHT. OPERATIONAL RUNS OF THE GFS/NAM ARE A LITTLE MORE DETAILED...HINTING AT SOME SORT OF WAVE FORMING ALONG THE SLOW MOVING WARM FRONT AND BRINGING THE INITIAL SURGE OF SHOWERS...WITH SOMEWHAT OF A LULL POSSIBLE FOR THE SECOND HALF OF THE OVERNIGHT...ESPECIALLY OVER NORTHERN AREAS. LOWS WILL RANGE FROM THE CHILLY MID 30S OVER THE NORTH TO AROUND 50 IN THE FAR SOUTH. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... 1 PM UPDATE... COLD HIGH PRESSURE ANCHORED TO OUR NORTH AND THE WAVY BOUNDARY TO OUR SOUTH WILL BE THE WEATHER DRIVERS FOR THE SHORT TERM. THE GFS SUPPRESSES MOST OF THE PRECIP SOUTH TO AROUND THE NY/PA BORDER BY LATER TUESDAY NIGHT EARLY WED AM...WHILE THE OPERATIONAL NAM AND ECMWF SHOW LIGHT QPF BEING MORE GENEROUSLY SPREAD ABOUT THE REGION. THE GEFS IS A LITTLE LESS OPTIMISTIC THAN ITS OPERATIONAL COUNTERPART WHILE THE SREF SUGGESTS THE NAM MAY BE TOO DRY. WILL USE A BLEND OF POPS FOR THE PERIOD WHICH LENDS SMALL CONFIDENCE TO ACTUALLY TRYING TO TIME WHEN THE BEST CHANCES FOR RAIN OR NO RAIN WILL END UP BEING. LOCAL RIVERS AND STREAMS ARE RUNNING HIGH...SO RAINFALL AMOUNTS NEED TO BE MONITORED FOR POSSIBLE PROBLEMS. AT THIS POINT...NO FLOODING IS EXPECTED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... UPDATED 300 PM...BLENDED PREVIOUS FORECAST WITH THE LATEST MEDIUM RANGE/WPC GUIDANCE WHICH RESULTED IN MINOR CHANGES. KEPT RISK FOR FREEZING RAIN AROUND MID-WEEK WITH HIGHEST POPS ON DAY 5/FRI WITH A SHARP COLD FRONTAL PASSAGE. OVERALL AN ACTIVE AND WET PERIOD THROUGH THE END OF THE WEEK BEFORE THINGS DRY OUT BEHIND THE FRONT THIS WEEKEND. PREVIOUS DISCUSSION... FORECAST ADJUSTED FOR TRENDS AND LATEST WPC GUIDANCE. A COUPLE THINGS TO NOTE. ONE IS THAT STRONG HIGH PRESSURE WILL BECOME CENTERED OVER FAR NORTHERN NEW ENGLAND-LOWER ST. LAWRENCE SEAWAY LATE WEDNESDAY NIGHT INTO EARLY THURSDAY...WHICH IS A GOOD SET UP FOR COLD AIR DAMMING. THERE APPEARS TO BE SOME POTENTIAL FOR LIGHT FREEZING RAIN HIGHER ELEVATIONS OF THE NORTHEASTERN ZONES DURING THAT TIME...THOUGH PRECIP CHANCES ITSELF NOT THAT HIGH AND AMOUNTS IF ANY WOULD BE VERY LIGHT. OTHERWISE THURSDAY- FRIDAY PERIOD LOOKS WET WITH MOIST WARM AIR ADVECTION ALLOWING TEMPERATURES TO TREND ABOVE CLIMATOLOGY INTO THE WEEKEND. OTHER THING THAT LATEST OPERATIONAL GFS-ECMWF RUNS INCREASE CONFIDENCE IN LARGE SURFACE HIGH DOMINATING SECOND HALF OF THE WEEKEND...FOR DRY AND MILD CONDITIONS SUNDAY. PREVIOUS DISCUSSION... CLOSELY FOLLOWED WPC GUIDANCE. A WET PATTERN CONTINUES AS BROAD SW FLOW ALOFT PREVAILS THROUGHOUT THE EXTENDED FORECAST PERIOD. THIS PATTERN ALOFT ALLOWS FOR MULTIPLE SHORTWAVES WITHIN THE UPPER LVL FLOW TO PASS OVER THE REGION BRINGING A CHANCE FOR RAIN SHOWERS EACH DAY. ATTM... THE BEST CHANCE FOR RAIN SHOWERS OVER THE REGION WILL BE THURS NIGHT THRU FRIDAY NIGHT. AS WE ARE AT THE TAIL END OF WINTER... THERE IS STILL A CHANCE AT NIGHT THAT SOME OF THESE SHOWERS COULD TRANSITION OVER TO SNOW. NO MAJOR ACCUMULATIONS ARE EXPECTED THROUGH THE EXTENDED. TEMPERATURES DURING THIS TIME FRAME ARE EXPECTED TO BE AT OR ABOVE THE SEASONAL NORM. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... 06Z UPDATE... AS HAS BEEN THE CASE THE LAST FEW DAYS...FORECAST REMAINS CHALLENGING WITH VARYING GUIDANCE /SOME MUCH TOO PESSIMISTIC/...FINE DETAILS...AND THUS LOWER CONFIDENCE THAN USUAL. IN THE BIG PICTURE...A FRONTAL BOUNDARY IS SAGGING SOUTHWARD THROUGH THE AREA AND THEN STALLING DURING THIS TAF PERIOD. FAIRLY QUIET AT THE MOMENT WITH VERY SPORADIC SHOWERS NOW AROUND KAVP...BUT WAVES MOVING ALONG THE FRONT WILL CAUSE ADDITIONAL SHOWERS TO DEVELOP DURING THE DAY...ESPECIALLY KITH- KBGM-KELM-KAVP. AS COOLER AIR CONTINUES TO ADVECT IN...LINGERING MOISTURE WILL CONDENSE AND BECOME TRAPPED UNDER SHALLOW INVERSION...WHICH ALONG WITH MOISTURE FROM PASSING SHOWERS SHOULD ALLOW MVFR CIGS TO DEVELOP KITH-KBGM-KAVP-KELM...EVENTUALLY FUEL ALT. IFR NOT OUT OF THE QUESTION /KBGM BEST CHANCE...KAVP POSSIBLE AS WELL LATE DUE TO MOISTURE AND FAVORABLE LIGHT NORTHEAST WIND/. KRME-KSYR APPEAR TO BE MAINLY VFR THIS PERIOD...BUT EARLY THIS MORNING WE WILL HAVE TO WATCH FOR POTENTIAL THIN OVC LAYER NEAR FUEL ALT-TO-MVFR LEVEL...BEFORE DRIER LOW LEVEL AIR ELIMINATES THE POSSIBILITY. NOT CONFIDENT ENOUGH TO INCLUDE IN TAF AT THIS TIME. WINDS GENERALLY VARIABLE TO LIGHT N/NE/E...SEE TAFS FOR SPECIFICS. .OUTLOOK... LATE TUE NGT-FRI...BUSY PATTERN WITH WAFFLING FRONTAL BOUNDARY REMAINING IN THE VICINITY...AND WAVES OF SHRA PLUS ASSOCIATED RESTRICTIONS MOVING ALONG IT. SLIGHT CHC TSRA AS WELL FRI. SAT...MAINLY VFR BUT ISOLATED -SHRA STILL POSSIBLE. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM...DJP SHORT TERM... LONG TERM... AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT TUE APR 7 2015 .SYNOPSIS... UNSEASONABLY WARM AND HUMID WEATHER IS EXPECTED OVER THE NEXT FEW DAYS WITH WEAK HIGH PRESSURE WELL OFF THE COAST. THERE IS A RISK OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH SATURDAY WITH THE HIGHEST POTENTIAL TODAY AND FRIDAY NIGHT INTO SATURDAY. A BACKDOOR COLD FRONT WILL MAKE A QUICK VISIT LATE WEDNESDAY NIGHT. IT WILL REMAIN WARM AND HUMID THROUGH FRIDAY. A COLD FRONT WILL USHER IN SEASONABLE TEMPERATURES OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM TUESDAY...SATELLITE AND RADAR SUGGEST THE UPPER DISTURBANCE IS OFFSHORE. CLOUDS HAVE FRAGMENTED A BIT INLAND ALTHOUGH THE INSOLATION IS CAUSING DESTABILIZATION OF THE BOUNDARY LAYER AND NEW CUMULUS TO FORM QUITE QUICKLY. FOR THIS REASON SKY COVER WILL PROBABLY AVERAGE MOSTLY CLOUDY THROUGH THE AFTERNOON. RADAR SHOWS SPRINKLES/SHOWERS ARE VERY FEW AND FAR BETWEEN...AND I HAVE DOUBTS WE`LL SEE ANYTHING SUBSTANTIAL THROUGH LATE AFTERNOON. HIGHS HAVE BEEN ADJUSTED DOWNWARD BY A DEGREE OR TWO FOR MOST AREAS. DISCUSSION FROM 1000 AM FOLLOWS... A WEAK UPPER LEVEL DISTURBANCE IS PASSING ACROSS THE EASTERN CAROLINAS CURRENTLY. THIS FEATURE SHOWS UP QUITE WELL IN WATER VAPOR IMAGERY...BUT UNFORTUNATELY IT HAS OUTRUN DEEP MOISTURE AND SHOWER ACTIVITY IS DRYING UP AS IT APPROACHES THE COAST. I HAVE KEPT IN SMALL POPS (20-40 PERCENT) FOR THE NEXT COUPLE OF HOURS ALONG THE COAST BUT HAVE LITTLE FAITH ANYONE WILL SEE MORE THAN AN ADDITIONAL .01 OR .02 INCHES BEFORE THIS ACTIVITY EITHER COMPLETELY DISSIPATES OR MOVES OFFSHORE. BEHIND THIS DISTURBANCE IMPLIED NET DOWNWARD ATMOSPHERIC MOTION WILL PROBABLY LEAD TO SEVERAL HOURS OF PARTLY CLOUDY SKIES WITH TEMPERATURES SOARING INTO THE LOWER 80S INLAND...EXCEPT 5-10 DEGREES COOLER NEAR THE COAST GIVEN THE COOL ONSHORE FLOW FROM OCEAN WATER TEMPERATURES ONLY IN THE LOWER 60S. GIVEN DEWPOINTS NOW RECOVERING WELL INTO THE 60S I EXPECT TO SEE A HEALTHY CUMULUS DECK FILL IN. ANOTHER WEAK UPPER LEVEL DISTURBANCE WILL APPROACH FROM THE NORTHWEST THIS EVENING...POSSIBLY ACCOMPANIED BY A LINE OF SHOWERS AND THUNDERSTORMS. WHILE I WOULD LOVE TO SHOW RAIN WITH THIS FEATURE MAKING IT DOWN INTO WILMINGTON (WHERE IT`S BEEN 10 DAYS WITHOUT MEASURABLE RAIN NOW) IT IS HARD TO FIND SUPPORT FOR MORE THAN 30-40 POPS. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY...WEDNESDAY BRINGS UNSEASONABLE WARMTH AND HUMIDITY. IN FACT, CONSIDERABLE INSTABILITY IS FORECAST TO DEVELOP AWAY FROM THE STABILIZING EFFECT OF THE OCEAN. SO WE HAVE TWO OF THE THREE INGREDIENTS FOR THUNDERSTORMS IN PLACE. THE THIRD HOWEVER, LIFT, MAY BE A BIT LACKING. IN PART THIS MAY HINGE UPON HOW STORMY TUESDAY ENDS UP AS AN ACTIVE DAY COULD LEAVE BEHIND SOME OUTFLOW BOUNDARIES. THERE WILL CERTAINLY BE SOME UNEVENNESS IN THE CLOUD COVER SO SOME DIFFERENTIAL HEATING BOUNDARIES MAY DEVELOP AS WELL. WHERE POPS TEND TO FOCUS WEDNESDAY NIGHT (ALBEIT CAPPED AT 20 FOR NOW) WILL DEPEND ON HOW FAR SOUTH A BACKDOOR COLD FRONT SINKS. IT APPEARS THAT A FEW THUNDERSTORMS WILL TRAIN EASTWARD ALONG ITS LENGTH, BUT NOT ALL MODELS ARE CONVINCED THAT IT GETS TOO FAR INTO OUR AREA, IF AT ALL. REGARDLESS, THIS BOUNDARY THEN HIGHTAILS IT BACK TO THE NORTH ON THURSDAY. THIS ONCE AGAIN LEAVES THE AREA IN A SOUTHWESTERLY WARM AND MOIST FLOW REGIME. INSTABILITY WILL ONCE AGAIN DEVELOP AND SOME ISOLATED THUNDERSTORMS WILL BE POSSIBLE. THE ONSHORE FLOW COMPONENT WILL BE A LITTLE MORE PRONOUNCED POSSIBLY KEEPING THE IMMEDIATE COAST RAIN-FREE. TEMPERATURES WILL STILL BE ABOVE NORMAL BUT PERHAPS A FEW DEGREES TEMPERED FROM THE WEDNESDAY HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 300 AM TUESDAY... WE REMAIN IN THE WARM AND HUMID PRE-FRONTAL REGIME ON FRIDAY BUT COLD FRONT WILL BE APPROACHING. THIS SHOULD BE SUFFICIENT TO TOUCH OFF SCATTERED SHOWERS AND THUNDERSTORMS THAT WILL CONTINUE INTO THE NIGHTTIME WITH ACTUAL FROPA. THE ACTUAL PASSAGE OF THE FRONT WILL BE RATHER GRADUAL ESPECIALLY SINCE IT WILL BE CHANGING ITS ORIENTATION AS IT ALIGNS MORE WITH THE CONTINUED LOW AMPLITUDE ALOFT. SUNDAY AND MONDAY WILL FEATURE A SLIGHT COOLDOWN BACK TO CLIMATOLOGICAL TEMPERATURES. SUNDAY APPEARS TO BE RAIN-FREE WHEREAS SOME MOISTURE MAY RETURN SUFFICIENTLY ON MONDAY FOR SOME LOW RAIN CHANCES. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...ISOLATED SHOWERS THIS AFTERNOON MAINLY BETWEEN THE INLAND AND COASTAL TERMINALS. MVFR CIGS WILL RISE TO VFR MID-LATE AFTERNOON. AT KCRE/KMYR THERE REMAIN A POTENTIAL FOR MVFR VSBYS IN BR WITH SCATTERED STRATUS AROUND 500 FEET UNTIL MID-AFTERNOON AS A NEARLY SATURATED AIRMASS MOVES ONSHORE. THERE IS A POTENTIAL FOR SHOWERS/ISOLATED THUNDERSTORMS THIS EVENING WITH BEST THUNDERSTORM POTENTIAL AT KFLO/KLBT. AFTER MIDNIGHT Z MVFR VSBYS/-RA BR WILL DEVELOP. EXPECTED CLOUD COVER SHOULD LIMIT POTENTIAL FOR IFR. VFR EXPECTED AFTER SUNRISE WITH LIGHT WNW WINDS. EXTENDED OUTLOOK...VFR. CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY...BEST CHANCE FOR PRECIPITATION IS FRIDAY NIGHT INTO SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM TUESDAY...WINDS ARE STILL BACKED AROUND MORE EAST TO SOUTHEASTERLY THAN MODELS INDICATED. LATEST RUC AND HRRR WIND FIELDS ARE TOO NOISY TO USE SO I HAVE MANUALLY ADJUSTED WIND DIRECTIONS COUNTERCLOCKWISE. STRONGEST WIND SPEEDS ARE NEAR AND NORTH OF THE WEAK LOW OUT BEYOND FRYING PAN SHOALS...12-15 KT NORTH OF CAPE FEAR...WITH 10 KT OR LESS FOR THE SC WATERS. DISCUSSION FROM 1000 AM FOLLOWS... SYNOPTIC HIGH PRESSURE IS WELL OFF THE COAST. WHAT APPEARS TO BE MAINLY A MID-LEVEL CIRCULATION HAS FORMED WITHIN A LARGE AREA OF RAIN AND EMBEDDED CONVECTION OFF THE COAST THIS MORNING. ALTHOUGH I HAVEN`T SEEN MUCH INCREASE IN WIND VELOCITY...WIND DIRECTIONS HAVE BEEN PERTURBED COUNTERCLOCKWISE BY THIS FEATURE WITH EAST FLOW ALONG THE CAPE FEAR COAST BACKING TO NORTHEASTERLY ALONG THE GRAND STRAND DOWN TOWARD GEORGETOWN. THIS FEATURE SHOULD PUSH OFFSHORE THIS AFTERNOON WITH THE SYNOPTIC SOUTHERLY WIND REESTABLISHING ITSELF. A WEAK SEABREEZE CIRCULATION SHOULD AUGMENT THIS WIND...WITH SOUTH WINDS GENERALLY IN THE 10-15 KT RANGE THROUGH THIS EVENING. ONCE ANY LINGERING MORNING RAIN CLEARS THE CAPE FEAR REGION...GENERALLY DRY CONDITIONS ARE EXPECTED ACROSS THE COASTAL WATERS. THE APPROACH OF ANOTHER WEAK DISTURBANCE THIS EVENING MAY GENERATE SOME MORE SHOWERS AND THUNDERSTORMS...BUT THESE MAY HAVE TROUBLE MAKING IT DOWN BEYOND THE COASTLINE DUE TO COOLER AND MORE STABLE AIR STREAMING ONSHORE ACROSS THE COLD NEARSHORE WATER TEMPS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY... WEDNESDAY WILL BRING LIGHT SOUTHWESTERLY WINDS AROUND HIGH PRESSURE IN THE WESTERN ATLANTIC. THIS HIGH WILL BE QUITE WEAK AND POORLY DEFINED, NOT THE STALWART BERMUDA HIGH OFTEN SEEN IN THE WARMER MONTHS. THIS IS WHY WINDS WILL BE SO LIGHT AND SWELL ENERGY LACKING. SOME FORECAST UNCERTAINTIES CROP UP WEDNESDAY NIGHT INTO THURSDAY MORNING FOR OUR NORTHERN WATERS. A BACKDOOR COLD FRONT WILL SAG SOUTHWARD CLOSE TO OR PARTIALLY INTO THE REGION, DEPENDING ON MODEL CHOICE. CURRENT THINKING IS THAT A NORTHEASTERLY FLOW MAY BRIEFLY AFFECT NORTHERN ZONES BUT THIS BOUNDARY WILL RETREAT BACK NORTHWARD ON THURSDAY. A RETURN TO LIGHT SOUTH TO SOUTHWESTERLY FLOW EXPECTED AS SEAS REMAIN MINIMAL. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 300 AM TUESDAY...FRIDAY BRINGS A CONTINUATION OF THE QUIET CONDITIONS SEEN THROUGH MOST OF THE SHORT TERM. THAT IS, A LIGHT S TO SWRLY FLOW AND SEAS NO HIGHER THAN 3 FT. WE MAY ADD A FEW KNOTS OF WIND FRIDAY NIGHT AND SW WILL BECOME MORE LIKELY THAN S DUE TO A COLD FRONT APPROACHING FROM THE NW. FROPA ITSELF MAY BE A LITTLE LAZY ON SATURDAY AS THE BOUNDARY DECELERATES AND CHANGES ORIENTATION TO A MORE WEST-TO-EAST NATURE AS IT TRIES TO ALIGN WITH THE FLOW ALOFT. EVENTUALLY A NEERLY FLOW WILL OVERSPREAD THE WATERS ON SATURDAY. THE CHANGE IN DIRECTION MAY SHORTEN THE DOMINANT PERIOD BUT ANY UPTICK IN DOMINANT WAVE HEIGHT SHOULD BE VERY MINOR. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...RJD/TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT TUE APR 7 2015 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH OF THE AREA ON THURSDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 250 AM TUESDAY... AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON... ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500- 750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND 25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION AND ITS ACCOMPANYING STRONG BUT WANING UPPER DIVERGENCE BRINGS IT INTO WRN NC EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO DROP BACK TO A 10-20% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS. WARM LOWS TONIGHT OF 59-65 WITH AREAS OF FOG. -GIH && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 325 AM TUESDAY... WE`LL BE FIRMLY IN THE WARM SECTOR WED WITH PW VALUES HOLDING NEAR 200% OF NORMAL. WE SHOULD INITIALLY SEE WEAK SUBSIDENCE BEHIND THIS EVENING`S WAVE AS IT SHIFTS OFF THE NC/VA COAST... HOWEVER AS IT INDUCES WEAK BUT IMPORTANT CYCLOGENESIS JUST OFF THE COAST... THE FLOW AROUND THIS LOW WILL HELP DRAW THE SURFACE FRONTAL ZONE TO OUR NORTH (NOW EXTENDING ROUGHLY WEST-EAST JUST NORTH OF THE OH VALLEY INTO THE NYC AREA) TO THE SOUTH INTO VA/NC LATE WED. THE GFS REMAINS THE MOST BULLISH IN PUSHING THE FRONTAL ZONE WELL SOUTHWARD INTO THE SRN CWA... WHEREAS THE NAM (WITH ITS MORE-OFFSHORE LOW) AND THE ECMWF (MUCH WEAKER LOW) HOLD IT NORTH OF THE NC/VA BORDER OR PERHAPS DIP IT JUST BARELY INTO OUR NE CWA. HAVE OPTED TO FAVOR THE LATTER SOLUTION BASED ON THE FAR-NORTH POSITION OF THE PARENT HIGH/COLD AIR AND LOW CONFIDENCE IN THE GFS`S STRONGER AND MORE WESTWARD LOW. FORECAST MUCAPE PEAKS AT 750-1500 J/KG ON THE GFS AND 1500-2500 J/KG ON THE NAM WED AFTERNOON... BUT WITH CONTINUED MODEST DEEP LAYER SHEAR OF 25-30 KTS. GIVEN THE MOISTURE IN PLACE THOUGH... WILL RAMP UP POPS TO GOOD CHANCE FOR AFTERNOON INTO EARLY EVENING... TRENDING BACK DOWN TO 20-30% CHANCE FROM LATE EVENING ONWARD THROUGH WED NIGHT WITH LOWERING INSTABILITY... BUT WE MAY STILL SEE SCATTERED SHOWERS CONCENTRATED NEAR AND JUST SOUTH OF THE FRONTAL ZONE... OVER NRN CWA. VERY WARM THICKNESSES SUPPORT HIGHS OF 77-85 (NE TO SW). ANOTHER NIGHT OF WARM LOWS IN THE UPPER 50S TO LOWER 60S... WITH REDUCED CONFIDENCE... AS A FARTHER-SOUTH PENETRATION OF THE FRONT WOULD MEAN COOLER TEMPS IN THE NE CWA. -GIH && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 255 AM MONDAY... STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE. MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE DAY 5 CONVECTIVE OUTLOOK FROM SPC. SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY AFTERNOON. TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 650 AM TUESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING TO MVFR/IFR THIS MORNING... THEN MVFR CIGS ARE EXPECTED THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE FORECAST PERIOD. AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS MORNING. A PASSING DISTURBANCE ALOFT THIS MORNING WILL LEAD TO A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST FEW HOURS OF THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO BE PREDOMINANTLY MVFR/IFR THROUGH MID MORNING. RECOVERY TO MAINLY MVFR CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS IN THE LAST 6-9 HOURS OF THE TAF VALID PERIOD. LOOKING BEYOND 12Z WED MORNING: IFR/LIFR CONDITIONS EARLY WED SHOULD LIFT TO MVFR BY NOON AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS THU AFTERNOON MAY BRING BRIEF SUB- VFR CONDITIONS. MORE WIDESPREAD AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD FRONT APPROACHING LATE FRI. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT TUE APR 7 2015 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH OF THE AREA ON THURSDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 250 AM TUESDAY... AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON... ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500- 750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND 25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION AND ITS ACCOMPANYING STRONG BUT WANING UPPER DIVERGENCE BRINGS IT INTO WRN NC EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO DROP BACK TO A 10-20% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID-UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS. WARM LOWS TONIGHT OF 59-65 WITH AREAS OF FOG. -GIH && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 325 AM TUESDAY... WE`LL BE FIRMLY IN THE WARM SECTOR WED WITH PW VALUES HOLDING NEAR 200% OF NORMAL. WE SHOULD INITIALLY SEE WEAK SUBSIDENCE BEHIND THIS EVENING`S WAVE AS IT SHIFTS OFF THE NC/VA COAST... HOWEVER AS IT INDUCES WEAK BUT IMPORTANT CYCLOGENESIS JUST OFF THE COAST... THE FLOW AROUND THIS LOW WILL HELP DRAW THE SURFACE FRONTAL ZONE TO OUR NORTH (NOW EXTENDING ROUGHLY WEST-EAST JUST NORTH OF THE OH VALLEY INTO THE NYC AREA) TO THE SOUTH INTO VA/NC LATE WED. THE GFS REMAINS THE MOST BULLISH IN PUSHING THE FRONTAL ZONE WELL SOUTHWARD INTO THE SRN CWA... WHEREAS THE NAM (WITH ITS MORE-OFFSHORE LOW) AND THE ECMWF (MUCH WEAKER LOW) HOLD IT NORTH OF THE NC/VA BORDER OR PERHAPS DIP IT JUST BARELY INTO OUR NE CWA. HAVE OPTED TO FAVOR THE LATTER SOLUTION BASED ON THE FAR-NORTH POSITION OF THE PARENT HIGH/COLD AIR AND LOW CONFIDENCE IN THE GFS`S STRONGER AND MORE WESTWARD LOW. FORECAST MUCAPE PEAKS AT 750-1500 J/KG ON THE GFS AND 1500-2500 J/KG ON THE NAM WED AFTERNOON... BUT WITH CONTINUED MODEST DEEP LAYER SHEAR OF 25-30 KTS. GIVEN THE MOISTURE IN PLACE THOUGH... WILL RAMP UP POPS TO GOOD CHANCE FOR AFTERNOON INTO EARLY EVENING... TRENDING BACK DOWN TO 20-30% CHANCE FROM LATE EVENING ONWARD THROUGH WED NIGHT WITH LOWERING INSTABILITY... BUT WE MAY STILL SEE SCATTERED SHOWERS CONCENTRATED NEAR AND JUST SOUTH OF THE FRONTAL ZONE... OVER NRN CWA. VERY WARM THICKNESSES SUPPORT HIGHS OF 77-85 (NE TO SW). ANOTHER NIGHT OF WARM LOWS IN THE UPPER 50S TO LOWER 60S... WITH REDUCED CONFIDENCE... AS A FARTHER-SOUTH PENETRATION OF THE FRONT WOULD MEAN COOLER TEMPS IN THE NE CWA. -GIH && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 255 AM MONDAY... STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE. MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE DAY 5 CONVECTIVE OUTLOOK FROM SPC. SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY AFTERNOON. TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 200 AM TUESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE FORECAST PERIOD (AFTER 03Z TONIGHT). AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS TOWARD THE END OF THE TAF VALID PERIOD. LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD FRONT APPROACHING LATE FRI. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
254 AM EDT TUE APR 7 2015 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH OF THE AREA ON THURSDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 250 AM TUESDAY... AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON... ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500- 750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND 25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION BRINGS IT INTO WRN NC EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO DROP BACK TO A 20-30% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID- UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS. WARM LOWS TONIGHT OF 59-65. -GIH && .SHORT TERM / /... AS OF 345 PM MONDAY... TO BE UPDATED SHORTLY. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 255 AM MONDAY... STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE FIRST PART OF THE LONG TERM AS IT IS STILL UNCLEAR HOW FAR SOUTH A BACKDOOR COLD FRONT WILL PUSH ON THURSDAY. HIGH SURFACE PRESSURE APPEARS TO BE TOO FAR TO THE NORTHEAST TO PRODUCE A STRONG CAD EVENT THIS TIME OF YEAR...BUT IT MAY HAVE SOME HELP AS LOW PRESSURE OFF THE MID-ATLANTIC COAST COULD WORK IN TANDEM WITH THE HIGH TO FUNNEL COLD AIR DOWN INTO THE CAROLINAS. THE STRENGTH AND LOCATION OF THIS LOW COULD BE THE KEY TO THE FORECAST. AT THIS TIME THE ECMWF AND THE NAM BOTH HAVE THE LOW FAIRLY FAR OFFSHORE AND WEAKER THAN THE GFS SOLUTION WHICH PUTS THE LOW MUCH FURTHER SOUTHWEST OFF OF THE NORTHERN OUTER BANKS. THIS LATE IN THE YEAR WOULD EXPECT THE GFS SOLUTION TO BE TOO STRONG WITH THE CAD SCENARIO AND THUS WILL FAVOR A NON-GFS SOLUTION...RESULTING IN WARMER TEMPS FOR THURSDAY THAN MOS GUIDANCE. ONLY LIGHT RAIN EXPECTED UNTIL LATER IN THE EVENING WHEN MORE RETURN FLOW MOISTURE MOVES OVER CENTRAL NC. IT SHOULD BE NOTED THAT IF THE GFS SOLUTION IS CORRECT THE FORECASTED TEMPERATURES WILL BUST ON THE HIGH SIDE. MODELS COME INTO BETTER AGREEMENT FOR THE END OF THE WEEK WITH A COLD FRONT PROGGED TO MOVE ACROSS THE STATE FRIDAY EVENING THROUGH SATURDAY AFTERNOON. WHILE THE EVENT DOES NOT LOOK OVERWHELMING AS FAR AS SEVERE POTENTIAL IS CONCERNED...THERE WILL BE INSTABILITY BETWEEN 500-1000 J/KG AND BULK SHEAR VALUES BETWEEN 20-30 KTS WHICH IS PLENTY FOR CONVECTIVE SHOWERS AND THUNDERSTORMS. ADD SOME INCREASED FORCING FOR ASCENT AHEAD OF THE FRONT AND THE SEVERE POTENTIAL INCREASES SLIGHTLY...ENOUGH TO WARRANT A 15% RISK IN THE DAY 5 CONVECTIVE OUTLOOK FROM SPC. SURFACE HIGH PRESSURE MOVES IN BEHIND THE FRONT ON SATURDAY NIGHT WHICH BRINGS IN A COOLER AND DRIER AIRMASS FOR ON SUNDAY AS THE HIGH SHIFTS OFFSHORE. RAIN RETURNS FOR MONDAY HOWEVER AS A STRONG LOW PRESSURE SYSTEM OVER THE UPPER MIDWEST USHERS A WARM FRONT OVER CENTRAL NC FROM THE SOUTHWEST. CONDITIONS WILL REMAIN FAIRLY SOGGY UNTIL PASSAGE OF THE TRAILING COLD FRONT SOMETIME ON TUESDAY AFTERNOON. TEMPERATURES THROUGH THE PERIOD WILL FEATURE HIGHS IN THE MID 70S TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 200 AM TUESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE FORECAST PERIOD (AFTER 03Z TONIGHT). AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS TOWARD THE END OF THE TAF VALID PERIOD. LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD FRONT APPROACHING LATE FRI. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...VINCENT LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EDT TUE APR 7 2015 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL PASS OVER THE AREA THIS MORNING. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION LATER TODAY... KEEPING A WARM MOIST AIR MASS OVER NORTH CAROLINA THROUGH WEDNESDAY. A BACKDOOR COLD FRONT TO OUR NORTH WILL DIP SOUTHWARD INTO NORTHEAST NORTH CAROLINA LATE WEDNESDAY... THEN LIFT BACK NORTH OF THE AREA ON THURSDAY. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 250 AM TUESDAY... AN UNSETTLED PERIOD OF WEATHER BEGINS TODAY AND EXTENDS THROUGH LATE IN THE WORK WEEK. A SHORTWAVE ALOFT (MOST EVIDENT AT 850-700 MB) AND RESULTANT AREA OF SHOWERS NOW MOVING THROUGH THE CWA WILL BE MOVING TO OUR EAST BY MID TO LATE MORNING... ALTHOUGH THE HIGH WATER CONTENT (PW NEAR 200% OF NORMAL) AND POTENTIAL FOR WEAK INSTABILITY NECESSITATES LEAVING IN A LOW CHANCE FOR A SHOWER OR TWO BEHIND THIS CURRENT SHOWER AREA FROM LATE MORNING THROUGH EARLY AFTERNOON... IN ACCORD WITH THE LATEST HRRR MODEL RUNS... DESPITE SOME POST-WAVE SUBSIDENCE. WE SHOULD SEE AN UPTICK IN INSTABILITY THIS AFTERNOON... ALTHOUGH THIS SHOULD REMAIN ON THE WEAK SIDE WITH NAM MUCAPE OF 500- 750 J/KG AT MOST... AND DEEP LAYER SHEAR WILL BE MARGINAL AT AROUND 25-30 KTS. LARGE SCALE MODELS SHOW A WEAK MID LEVEL PERTURBATION MOVING IN FROM THE WEST LATE TODAY INTO EARLY THIS EVENING... AND THIS SEEMS TO CORRELATE WITH A BROKEN BAND OF CONVECTION NOW EXTENDING FROM LOWER MI TO A MORE ORGANIZED COMPLEX OVER SRN IL TO AR/ERN TX. EXTRAPOLATION OF THIS CONVECTION BRINGS IT INTO WRN NC EARLY THIS EVENING... A TIMING SUPPORTED BY THE HRRR AND HI-RES ARW/NMM MODELS. WILL REFLECT THE RELATIVE LULL IN PRECIP BEFORE RAMPING BACK UP TO HIGH CHANCE/LIKELY POPS LATER THIS AFTERNOON INTO EARLY/MID EVENING... LEAVING IT AS PRIMARILY SHOWERS (DUE TO UNIMPRESSIVE FORECAST CAPE/SHEAR) AND ISOLATED STORMS. EXPECT PRECIP CHANCES TO DROP BACK TO A 20-30% CHANCE AT MOST OVERNIGHT WITH LOSS OF HEATING AND POST-WAVE SINKING AIR HELPING TO DRY OUT THE MID- UPPER LEVELS SOMEWHAT. THE MILD START TO THE DAY AND ANTICIPATED BREAK IN THE PRECIP ALONG WITH THICKNESSES NEARLY 20 M ABOVE NORMAL SHOULD ALLOW TEMPS TO PEAK TODAY IN THE 73-79 RANGE DESPITE PLENTY OF CLOUDS. WARM LOWS TONIGHT OF 59-65. -GIH && .SHORT TERM / /... AS OF 345 PM MONDAY... TO BE UPDATED SHORTLY. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 305 PM MONDAY... THE MODELS HAVE BEEN FLIP-FLOPPING ON THE SOUTHWARD PENETRATION OF A COLD FRONT DOWN THE EASTERN SEABOARD INTO THE MID-ATLANTIC STATES WEDNESDAY INTO THURSDAY. THIS TREND CONTINUED WITH THE 12Z/MODEL SUITE. THIS HAS FORECAST IMPLICATIONS BOTH DAYS IN TERMS OF MAX TEMPERATURES/CLOUDS/INSTABILITY/AND CONVECTIVE CHANCES. SINCE THE CENTER OF THE STRONG SURFACE HIGH PRESSURE IS FORECAST TO BE A BIT NORTH AND NORTHEAST OF THE FAVORED POSITION FOR DAMMING DEEP INTO NC/SC PIEDMONT DAMMING REGION... AND WITH THE UPPER RIDGE FORECAST TO SLOWLY BUILD EASTWARD ACROSS THE SOUTHEASTERN STATES DURING THE SAME TIME... THE COLD FRONT MAY NOT BE ABLE TO REACH AS FAR SOUTH AS THE 12Z/OPERATIONAL GFS DEPICTS (INTO NORTHERN SC BY 12Z/THU). HOWEVER... THIS TIME OF YEAR THE WATER TEMPERATURES ARE STILL COLD NORTH OF CAPE HATTERAS... AND THEY ARE ABNORMALLY COLD THIS YEAR DUE TO THE COLD WINTER OVER THE NE STATES. WE SUGGEST THAT THE 12Z/NAM MAY BE THE BEST COMPROMISE GIVEN THE ABOVE DATA... AS THE 12Z/EC MAY NOT BE FAR ENOUGH SOUTH. THEREFORE... THE MORE SOUTHWARD PLACEMENT OF THE FRONT IS EXPECTED... WHICH WOULD PLACE THE COLD FRONT NEAR THE NC/VA BORDER WEDNESDAY AFTERNOON... THEN DIPPING SOUTHWARD TO NEAR HKY TO FAY TO ILM BY AROUND 12Z/THURSDAY. THE AIR MASS AND BOUNDARY LAYER OUT AHEAD OF THE FRONT WILL BE MODESTLY UNSTABLE... ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING. THE HIGHS ARE FORECAST TO REACH INTO THE UPPER 70S INTO THE LOWER 80S... WITH DEW POINTS AROUND 60. HOWEVER.. THE COLD FRONT AND ASSOCIATED LOW LEVEL CONVERGENCE SHOULD ARRIVE IN THE NORTHERN ZONES DURING THE MID TO LATE AFTERNOON... AND THEN IN THE WESTERN AND SOUTHERN ZONES IN THE EVENING OR LATER. THUS... THE NAM POP IN THE HIGH CHANCE RANGE FOR SHOWERS AND THUNDERSTORMS NORTH AND EAST BETWEEN 18Z-00Z SEEMS THE BEST FIT. THE CHANCE OF SHOWERS AND THUNDERSTORMS SHOULD PUSH SOUTHWARD WITH THE FRONT INTO THE WESTERN AND SOUTHERN ZONES WED EVENING. THE CHANCE OF SHOWERS SHOULD CONTINUE WED NIGHT AND THURSDAY... BUT CHANCES OF THUNDER APPEAR LOW GIVEN THE EXPECTED INCREASE IN THE COOLER/STABLE/CLOUDY LOW LEVELS NORTH OF THE FRONT. THE FRONT SHOULD EITHER BECOME DIFFUSE OR SLIP BACK NORTH AS A WARM FRONT ON THURSDAY INTO THURSDAY NIGHT... ALLOWING FOR A SLIM CHANCE OF SHOWERS TO CONTINUE WITH LIMITED UPPER SUPPORT. LOWS GENERALLY IN THE MID 50S TO NEAR 60 NE... AND LOWER TO MID 60S SOUTH. HIGHS THURSDAY SHOULD HOLD IN THE 70S (BUT IF FRONT PUSHES BACK NORTH QUICKER THAN EXPECTED... HIGHS IN THE LOWER TO MID 80S MAY RETURN A DAY SOONER... ESPECIALLY ACROSS THE SOUTH. FRIDAY INTO SATURDAY... THE STORM TRACK STILL IS EXPECTED TO OUR WEST AND NORTH... FINALLY DRAGGING A COLD FRONT INTO AND THROUGH THE REGION LATE FRIDAY INTO SATURDAY MORNING. A BAND OF SHOWERS AND SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONT OR A PRE- FRONTAL TROUGH (HIGHEST CHANCES LATE FRIDAY INTO EARLY SATURDAY). FRIDAY SHOULD BE VERY WARM WITH HIGHS IN THE LOWER TO MID 80S. A TURN TO COOLER AND DRIER CONDITIONS ARE EXPECTED BEHIND THE FRONT LATER IN THE WEEKEND INTO MONDAY. LOWS IN THE UPPER 40S AND 50S. HIGHS IN THE 70S SUNDAY AND MONDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 200 AM TUESDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: GOOD CHANCE OF CIGS DROPPING TO MVFR THEN IFR EARLY THIS MORNING... THEN MVFR CIGS ARE EXPECTED THIS AFTERNOON. POTENTIAL IFR/LIFR CIGS/VSBYS TOWARD THE END OF THE FORECAST PERIOD (AFTER 03Z TONIGHT). AVIATION CONDITIONS WILL BECOME MORE UNSETTLED AND ADVERSE THIS MORNING. A PASSING DISTURBANCE ALOFT EARLY THIS MORNING WILL LEAD TO A PERIOD OF SHOWERS WITH MVFR VSBYS IN THE FIRST SEVERAL HOURS OF THE FORECAST... MOVING WEST TO EAST... WITH CIGS LIKELY TO DROP TO MVFR THEN IFR NEAR OR JUST BEFORE SUNRISE. RECOVERY TO MAINLY MVFR CIGS IS EXPECTED LATER THIS MORNING... THEN THE NORTHWARD MOVEMENT OF A WARM FRONTAL ZONE THROUGH THE AREA TODAY WITH ANOTHER DISTURBANCE WILL BRING ANOTHER CHANCE OF SHOWERS WITH MVFR VSBYS/CIGS MAINLY DURING THE MID TO LATE AFTERNOON. BY EARLY-MID EVENING... A PERIOD OF VFR CONDITIONS IS POSSIBLE BEHIND THE DEPARTING DISTURBANCE... BUT EXPECT DEVELOPMENT OF FOG AND LOW CLOUDS TOWARD MIDNIGHT... LEADING TO AREAS OF IFR/LIFR CONDITIONS TOWARD THE END OF THE TAF VALID PERIOD. LOOKING BEYOND 06Z EARLY WED MORNING: IFR/LIFR CONDITIONS ARE EXPECTED TO EXTEND UNTIL SUNRISE WED... THEN LIFT TO MVFR BY NOON AND TO VFR DURING THE EARLY-MID AFTERNOON. HEATING AND INSTABILITY WILL LEAD TO SCATTERED SHOWERS AND A FEW STORMS WED AFTERNOON WITH POTENTIAL SUB-VFR CONDITIONS. REDEVELOPMENT OF IFR/LIFR FOG/STRATUS IS POSSIBLE WED NIGHT INTO THU MORNING. ADDITIONAL SHOWERS/STORMS THU AFTERNOON MAY BRING BRIEF SUB-VFR CONDITIONS. MORE WIDESPREAD AND ORGANIZED SHOWERS AND STORMS ARE ANTICIPATED AHEAD OF A COLD FRONT APPROACHING LATE FRI. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...VINCENT LONG TERM...BADGETT AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1211 AM CDT TUE APR 7 2015 .UPDATE... ISSUED AT 1210 AM CDT TUE APR 7 2015 THE LATEST WATER VAPOR IMAGERY AND RADAR SHOWS SEVERAL MOISTURE PLUMES INCREASING WITH TIME...FROM NORTHWEST THROUGH NORTH CENTRAL NORTH DAKOTA...AND ACROSS CENTRAL/EASTERN MONTANA SOUTH INTO WYOMING AND WESTERN SOUTH DAKOTA. LARGE SCALE ASCENT BEING MAXIMIZED IN EASTTERN MONTANA AND AREAS SOUTH...AHEAD OF A NEGATIVELY TILTED 700MB-500MB SHORTWAVE TROUGH LOCATED IN NORTH CENTRAL MONTANA. BOWMAN RADAR NOW SHOWING INCREASING REFLECTIVITY`S UPSTREAM...WHICH COINCIDES WITH THE CURRENT FORECAST OVERNIGHT AS PRECIPITATION CHANCES INCREASE. STRONGEST LIFT PER OMEGA FIELD OCCURS FROM NEAR 12Z TUESDAY WEST...TRANSLATING EAST THROUGH 18Z. CATEGORICAL POPS CURRENTLY IN THE FORECAST LOOKS GOOD. WITH OVERALL POPS ON TRACK...NO CHANGES WITH THIS FORECAST UPDATE. UPDATE ISSUED AT 842 PM CDT MON APR 6 2015 ISENTROPIC LIFT GENERALLY LACKING ON THE 285K SURFACE OVER SOUTHWEST AND SOUTHERN NORTH DAKOTA THIS EVENING. MAIN ACTION FOR SNOW CONTINUES TO BE NORTHWEST INTO THE WEST CENTRAL SECTIONS OF NORTH DAKOTA. FOR THE REST OF THE EVENING WILL DROP POPS BELOW 15 PERCENT ACROSS THE SOUTHERN THIRD OF THE STATE. WILL THEN SLOWLY SPREAD CHANCE POPS BACK IN AFTER MIDNIGHT SOUTH. WILL ALSO TRIM QPF SOUTH AS WELL. THE NORTH LOOKS GOOD. UPDATE ISSUED AT 618 PM CDT MON APR 6 2015 LATEST HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE TRENDS EARLY THIS EVENING AND FOLLOWED FOR THE NEXT 6 HOURS OR SO. BAND OF PRECIPITATION SEEN ON RADAR EXTENDING FROM BISMARCK NORTHWEST TO BEACH IS MOVING NORTH AND WILL SPREAD ACROSS NORTHWEST ND WHERE CURRENT HIGH POPS ARE IN GOOD SHAPE. THIS LEAVES THE SOUTHERN THIRD OF THE STATE WITH LITTLE IN THE WAY OF PRECIPITATION. SO TRIMMED THE POPS BACK TO SLIGHT CHANCE ACROSS THE SOUTH FOR THE EVENING. FOCUSED ON THE WEST CENTRAL AND NORTHWEST WHERE BEST PRECIPITATION WILL BE WIDESPREAD THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 300 PM CDT MON APR 6 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE RAIN AND SNOW CHANCES AND AMOUNTS NOW THROUGH TUESDAY. CURRENTLY...THE FIRST IN A SERIES OF MID LEVEL S/WV`S APPROACHING THE NORTHERN PLAINS THIS AFTERNOON. IN RESPONSE PRECIPITATION DEVELOPMENT UNDERWAY SOUTHWEST WITH BEACH AND DICKINSON NOW REPORTING SNOW THE PAST HOUR. VERY DRY AIR ACROSS EASTERN NORTH DAKOTA WILL PREVENT ANYTHING FROM REACHING THE GROUND THIS AFTERNOON. PRECIPITATION WILL CONTINUE TO EXPAND NORTH AND EAST AS THE AFOREMENTIONED WAVE CONTINUES NORTHEAST AND ONCE A STRONGER/MORE INTENSE WAVE LIFTS INTO THE REGION TONIGHT. IN ADDITION...LOW/MID LEVEL WINDS WILL BECOME MORE SOUTHEAST TONIGHT VERSUS EASTERLY...ALLOWING FOR MOISTURE ADVECTION INTO THE REGION HELPING TO ERODE A VERY DRY BOUNDARY LAYER NOW IN PLACE. SHOULD SEE A TRANSITION TO ALL SNOW AFTER 00Z AS TEMPERATURES COOL. WILL CONTINUE THE SPECIAL WEATHER STATEMENT HIGHLIGHTING 3 TO 5 INCHES OF SNOW FOR PORTIONS OF THE WEST/NORTHWEST/NORTH CENTRAL DURING THE NEXT 36 HOURS. LESSER AMOUNTS STILL EXPECTED SOUTHWEST AND SOUTH CENTRAL WHERE A RAIN/SNOW MIX OR ALL RAIN WILL MINIMIZE ACCUMULATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CDT MON APR 6 2015 THE FOCUS OF THE LONG TERM FORECAST IS THE CHANCE FOR RAIN/SNOW WEDNESDAY. LATEST 12 UTC GUIDANCE (WITH THE EXCEPTION OF THE NAM) ARE IN GOOD AGREEMENT WITH RESPECT TO THE TIMING AND LOCATION OF PRECIPITATION WEDNESDAY. SNOW IS EXPECTED TO MIX WITH RAIN ACROSS SOUTHWESTERN NORTH DAKOTA WEDNESDAY MORNING AS A RATHER LARGE AND DEEP LOW PRESSURE CENTER MOVES ACROSS THE CENTRAL PLAINS. DURING THE DAY ON WEDNESDAY TEMPERATURES SHOULD BE WARM ENOUGH TO CHANGE SNOW OVER TO ALL RAIN AND MELT ANY PREVIOUSLY ACCUMULATED SNOW ACROSS SOUTHERN NORTH DAKOTA. THE MAJORITY OF THE PRECIPITATION AS DEPICTED IN THE 12 UTC GFS/ECMWF/SREF APPEARS MOST LIKELY TO FALL ALONG AND SOUTH OF INTERSTATE 94. AS COLDER AIR WRAPS AROUND THE DEPARTING LOW AND DIURNAL COOLING BEGINS...RAIN MAY TRANSITION BACK OVER TO SNOW WEDNESDAY NIGHT INTO THURSDAY MORNING. HOWEVER...ONLY MINOR AMOUNTS ARE ANTICIPATED TO ACCUMULATE AS GROUND TEMPERATURES SHOULD HOVER RIGHT AROUND FREEZING OVERNIGHT. THE REST OF THE EXTENDED LOOKS RATHER DRY AND MILD WITH TEMPERATURES IN THE 60S BY THE WEEKEND. PRECIPITATION MAY RETURN TO THE REGION BY THE END OF THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1210 AM CDT TUE APR 7 2015 CIGS/VSBYS WILL QUICKLY DETERIORATE TO MVFR/IFR STATUS BY 12Z TUESDAY AS LIGHT SNOW CONTINUES TO DEVELOP ACROSS THE TERMINALS. PRECIPITATION WILL BECOME WIDESPREAD FROM 12Z THROUGH 18Z TUESDAY. EXPECT PRECIPITATION TO WANE FROM SOUTHWEST TO NORTHEAST 18Z TUESDAY TO 00Z WEDNESDAY. ALTHOUGH VSBYS RETURN TO VFR EARLY TUESDAY AFTERNOON...SLOWER IMPROVEMENTS CAN BE EXPECTED IN THE CIGS...LIFTING TO MVFR AND POSSIBLY LOW VFR BETWEEN 00Z AND 06Z WEDNESDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...NH LONG TERM...AJ AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
954 PM EDT WED APR 8 2015 .SYNOPSIS... A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THURSDAY NIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT WITH A DRIER AIRMASS SETTLING INTO THE REGION FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS HAS PUSHED THROUGH THE AREA THIS EVENING WITH SOME STORMS BEING SEVERE. STORMS GOT GOING DUE TO A POTENT SHORTWAVE AND A STATIONARY BOUNDARY ACROSS OUR NORTHERN ZONES. WITH THE SHORTWAVE CURRENTLY EXITING THINK WE WILL GET A BIT OF A BREAK BEFORE STORMS GET GOING AGAIN AS THE NEXT UPPER LEVEL DISTURBANCE APPROACHES THE AREA. THERE IS SOME DISAGREEMENT ON WHETHER WE WILL GET ANOTHER BREAK OR NOT IN THE AFTERNOON. HRRR AND RAP SHOW REDEVELOPMENT WHILE ARW/ NAM HAVE REDEVELOPMENT NORTH OF THE AREA. FOR NOW HAVE ONLY MADE MINOR CHANGES TO FORECAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... PCPN CHANCES ON THURSDAY WILL BE AT LEAST SOMEWHAT DEPENDENT ON HOW THINGS PLAY OUT TONIGHT AND WHAT KIND OF LINGERING BOUNDARIES/DEBRIS CLOUDS ARE IN PLACE. AS A RESULT...IT IS TOUGH TO NAIL DOWN TIMING FOR POPS ON THURSDAY. HOWEVER...IN BROAD SOUTHWESTERLY FLOW AND WITH SEVERAL EMBEDDED MID LEVEL SHORTWAVES LIFTING THROUGH THE REGION...WILL BROAD BRUSH TO A DEGREE AND GO WITH LIKELY POPS FOR MUCH OF THE DAY THURSDAY. ASSUMING WE ARE ABLE TO SUFFICIENTLY DESTABILIZE THROUGH THE AFTERNOON...SHEAR PROFILES WILL BE SUPPORTIVE OF SEVERE STORMS AGAIN THURSDAY AFTERNOON INTO EVENING. THE PRIMARY THREAT WOULD BE DAMAGING WINDS AND LARGE HAIL ALTHOUGH AN ISOLATED TORNADO WOULD NOT BE OUT OF THE QUESTION. THE COLD FRONT WILL MOVE THROUGH LATE THURSDAY NIGHT WITH PCPN TAPERING OFF WEST TO EAST. HIGH PRESSURE AND A DRIER AIRMASS WILL THEN BUILD INTO THE REGION FOR THE END OF THE WEEK. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... PERIOD STARTS TRANQUIL BUT ACTIVE WEATHER IS FORECAST TO RETURN EARLY NEXT WEEK. A LARGE AREA OF HIGH PRESSURE WILL BE MOVING ACROSS THE AREA ON SATURDAY AND SUNDAY. THIS WILL BRING A DRY SPELL THROUGH THE WEEKEND. FOR MONDAY THROUGH WEDNESDAY...A WAVY FRONTAL BOUNDARY CONTAINING ABUNDANT DEEP MOISTURE WILL DEVELOP...RESULTING IN A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY. THOUGH IT IS TOO EARLY TO GIVE AN ACCURATE PREDICTION FOR COVERAGE...DURATION AND INTENSITY OF THUNDERSTORMS FOR A PARTICULAR LOCATION...THE POTENTIAL EXISTS FOR SEVERAL ROUNDS OF STRONG TO SEVERE CONVECTION FOR THE FIRST HALF OF NEXT WEEK. EXPECT BELOW NORMAL HIGHS IN THE MID 50S TO LOW 60S SATURDAY UNDER COLD ADVECTION ON A NORTHERLY FLOW AROUND HIGH PRESSURE. TEMPERATURES WILL SHOW A WARMING TREND STARTING ON SUNDAY AS THE LOW LEVEL FLOW TURNS SOUTHERLY...WITH HIGHS REACHING AROUND 70 IN MOST LOCATIONS BY WEDNESDAY. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... SHOWERS AND THUNDERSTORMS HAVE PUSHED IN FROM THE SOUTHWEST AND WEST THIS EVENING WITH TWO DISTINCT AREAS CURRENTLY ON RADAR. THE AREA OF STORMS TO THE NORTH ARE IN RESPONSE TO AN UPPER LEVEL DISTURBANCE ALONG WITH A STATIONARY FRONT THAT IS DRAPED ACROSS THE AREA. STORMS TO THE SOUTH ARE IN RESPONSE TO THE UPPER LEVEL DISTURBANCE. THE UPPER LEVEL DISTURBANCE IS FORECASTED TO PUSH THROUGH THE AREA OVER THE NEXT COUPLE OF HOURS AND CURRENT RADAR SHOWS A BREAK IN THE RAIN TO THE WEST. THEN EXPECT REDEVELOPMENT AGAIN TOMORROW MORNING AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES FROM THE WEST. OUTLOOK...THUNDERSTORMS POSSIBLE THURSDAY NIGHT/EARLY FRIDAY MORNING AS A COLD FRONT MOVES THROUGH THE AREA. GUSTY WEST WINDS ARE EXPECTED BEHIND THE COLD FRONT ON FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ060>063- 070>073-077>082-088. KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ089>100. IN...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR INZ050-058-059- 066-073>075-080. && $$ SYNOPSIS...HAINES/JGL NEAR TERM...HAINES SHORT TERM...JGL LONG TERM...CONIGLIO AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
832 PM EDT WED APR 8 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... 830 PM UPDATE... EXPANDED FFA FARTHER N TO ACCOUNT FOR WHERE COMPLEX IS COMING IN FROM THE W...AND WENT ACROSS THE NRN TIER TO ACCOUNT FOR CONVECTION ALONG THE 300K ISENTROPIC SFC GRADIENT H8-H85 THERE. 745 PM UPDATE... UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC GRADIENT H8-H85 ACROSS THE NRN TIER. 630 PM UPDATE... UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE. PREV DISCN... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... SHOWER AND THUNDERSTORM COMPLEXES WILL CONTINUE TO IMPACT THE AREA THROUGH THE PERIOD. THE FIRST WAS APPROACHING THE OHIO RIVER ALREADY AND WILL IMPACT THE AREA THROUGH 06Z W TO E. SUBSEQUENT ONES ARE TOUGHER TO TIME BUT THE NEXT ONE MAY IMPACT THE AREA THU MORNING EITHER SIDE OF DAWN. RIGHT NOW THE NRN TAF SITES ARE MOST LIKELY TO BE IMPACTED BY THIS SECOND ONE. HAVE MOSTLY VFR CONDITIONS IN THE TAFS BUT BRIEF MVFR AND BRIEF IFR FLIGHT CONDITIONS ARE LIKELY UNDER THE THUNDERSTORMS. SFC FLOW REGIME IS BASICALLY LIGHT AND VARIABLE OVERNIGHT INTO THU MORNING AND S TO SW AND A BIT GUSTY MIDDAY THU. STRONG GUSTS ARE POSSIBLE WITH THUNDERSTORMS FOLLOWED BY VARIABLE FLOW. MODERATE W TO SW FLW ALOFT EARLY WILL BECOME MODERATE SW OVERNIGHT AND REMAIN SO ON THU. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING/CATEGORY CHANGES IN SHOWERS/STORMS MAY VARY. UNCERTAIN ON POST-RAIN FOG FORMATION OVERNIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 04/09/15 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H M M M H H H H H H H HTS CONSISTENCY H M M L M M H H H H H H BKW CONSISTENCY H H H M H H H H H H H H EKN CONSISTENCY H H H M M H H H H H H H PKB CONSISTENCY H H H H H H H H H H M H CKB CONSISTENCY H H H H H H H H H H H M AFTER 00Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WVZ005>011- 013>017-019-020-024>026-031. OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ066-067-075- 076-083>087. KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/SL NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...SL AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
747 PM EDT WED APR 8 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... 745 PM UPDATE... UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC H8-H85 ACROSS THE NRN TIER. 630 PM UPDATE... UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE. PREV DISCN... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... SHOWER AND THUNDERSTORM COMPLEXES WILL CONTINUE TO IMPACT THE AREA THROUGH THE PERIOD. THE FIRST WAS APPROACHING THE OHIO RIVER ALREADY AND WILL IMPACT THE AREA THROUGH 06Z W TO E. SUBSEQUENT ONES ARE TOUGHER TO TIME BUT THE NEXT ONE MAY IMPACT THE AREA THU MORNING EITHER SIDE OF DAWN. RIGHT NOW THE NRN TAF SITES ARE MOST LIKELY TO BE IMPACTED BY THIS SECOND ONE. HAVE MOSTLY VFR CONDITIONS IN THE TAFS BUT BRIEF MVFR AND BRIEF IFR FLIGHT CONDITIONS ARE LIKELY UNDER THE THUNDERSTORMS. SFC FLOW REGIME IS BASICALLY LIGHT AND VARIABLE OVERNIGHT INTO THU MORNING AND S TO SW AND A BIT GUSTY MIDDAY THU. STRONG GUSTS ARE POSSIBLE WITH THUNDERSTORMS FOLLOWED BY VARIABLE FLOW. MODERATE W TO SW FLW ALOFT EARLY WILL BECOME MODERATE SW OVERNIGHT AND REMAIN SO ON THU. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING/CATEGORY CHANGES IN SHOWERS/STORMS MAY VARY. UNCERTAIN ON POST-RAIN FOG FORMATION OVERNIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 04/09/15 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H M M M H H H H H H H HTS CONSISTENCY H M M L M M H H H H H H BKW CONSISTENCY H H H M H H H H H H H H EKN CONSISTENCY H H H M M H H H H H H H PKB CONSISTENCY H H H H H H H H H H M H CKB CONSISTENCY H H H H H H H H H H H M AFTER 00Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR WVZ005-006-013. OH...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OHZ087. KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/SL NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...SL AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
243 PM EDT TUE APR 7 2015 .SYNOPSIS... A WARM AND MOIST SOUTH TO SOUTHWEST WIND FLOW WILL BRING ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK. COLD FRONT CROSSES AT THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... LOTS OF CONVECTION TO OUR WEST...WITH ONLY LINGERING MASS ACROSS THE NORTHERN MOUNTAINS. TO OUR WEST...HAVE AREA BETWEEN KHTS AND KLEX...MOVING SOUTHEAST ALONG A WEAK SURFACE BOUNDARY. THIS CONVECTION WILL MOVE ACROSS THE SOUTHERN CWA LATE THIS AFTERNOON INTO THIS EVENING. FARTHER WEST...IN SOUTHERN INDIANA HAVE ANOTHER COMPLEX MOVING EAST. NAM/HRRR AND SOME WRF RUNS SHOW A MCV WITH THIS MOVING ACROSS SOUTHERN CWA TONIGHT. RAP IS A BIT FARTHER NORTH. AS A SURFACE LOW MOVES THROUGH MISSOURI TONIGHT...EXPECT THE SURFACE BOUNDARY TO SLOWLY MOVE NORTH CROSSING SOUTHERN CWA DURING THE EARLY MORNING. WITH A FAIRLY WET GROUND IN PLACE ACROSS SOUTHERN CWA AFTER HEAVY RAIN LATE LAST WEEK...AND ANTICIPATING ANOTHER COUPLE ROUNDS OF AT LEAST MODERATE RAIN TONIGHT...WITH GO WITH A FLASH FLOOD WATCH ALONG AND SOUTH OF I-64. BEST CASE SCENARIO IS THE HEAVIEST RAIN STICKS CLOSER TO THE INFLOW AND REMAINS MAINLY SOUTH OF CWA...WITH JUST A PERIOD OF LIGHT TO MODERATE RAIN WITH THE REMNANTS OF THE MCV. WORST CASE WOULD BE IF EACH WAVE CROSSES THROUGH THE SAME AREA OF SOUTHERN CWA. EXPECT A BREAK IN PRECIP...ALTHOUGH CANNOT RULE OUT AN ISOLATED SHOWER...THROUGH MUCH OF WEDNESDAY MORNING. HAVE ANOTHER AREA OF LIKELY POPS MOVING FROM WEST TO EAST ACROSS CWA WEDNESDAY AFTERNOON AS A SHORTWAVE TROUGH MOVES OVER. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... MODELS ARE CLOSER TO AGREEMENT...ON LIFTING A SURFACE BOUNDARY AND UPPER IMPULSE NORTH ACROSS THE AREA WEDNESDAY NIGHT...FOLLOWED BY A COLD FRONT LATE THURSDAY NIGHT AND FRIDAY. WITH MOIST AND UNSTABLE AIR IN PLACE...THESE TWO FEATURES WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY THE COLD FRONT. IN BETWEEN...IN THE WARM SECTOR ON THURSDAY...THERE COULD BE A SHOWER OR THUNDERSTORM ESPECIALLY IN THE AFTERNOON WITH HEATING. TIMING OF COLD FRONT HAS IT REACHING THE OHIO RIVER AROUND DAWN FRIDAY...THEN PROGRESSING ACROSS THE REMAINDER OF AREA DURING FRIDAY. WITH GOOD UPPER SUPPORT AND PLENTY OF WARM AND MOIST UNSTABLE AIR...A BAND OF ORGANIZED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ALONG AND AHEAD OF THE COLD FRONT. WILL HAVE TO WATCH FOR WATER PROBLEMS AND STRONG STORMS IN THIS TIME FRAME. UPON COLD FRONT PASSAGE FRIDAY...EXPECT IMPROVEMENT FROM THE WEST. TEMPERATURE RANGES THIS PERIOD WILL BE LOWERED SOMEWHAT BY THE CLOUDS AND SHOWERS...BUT THURSDAY MAY BE WARMER THAN FORECAST IF SUNSHINE MAKES A DETERMINED APPEARANCE IN THE WARM SECTOR. IN ANY CASE...NO EXTREMES IN TEMPERATURE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MODELS ARE QUICKER WITH THE COLD FRONTAL PASSAGE ON FRIDAY LEAVING FRIDAY NIGHT MOSTLY DRY. THE OUTLIER IS THE ECMWF WHICH LAGS ABOUT 6 HOURS IN ITS QPF FIELD. WENT WITH THE CONSENSUS OF MODELS WITH A FASTER SOLUTIONS. HIGH PRESSURE BRINGS WIDESPREAD DRY WEATHER FRIDAY NIGHT THROUGH THE WEEKEND. ANOTHER UPPER WAVE APPROACHES MONDAY BRINGING BACK CHANCES FOR PCPN ACROSS THE AREA. TEMPERATURES EXPECTED TO BE WARM REACHING THE UPPER 70S THROUGH THE PERIOD...EXCEPT FOR A SLIGHT COOL DOWN BEHIND THE COLD FRONT SATURDAY...GENERALLY IN THE MID TO UPPER 60S. WENT CLOSE TO WPC GUIDANCE WITH FEW TWEAKS THROUGH THE PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... MESSY SITUATION WITH SHOWERS AND SOME THUNDERSTORMS DRIFTING MAINLY EASTWARD ACROSS CWA. SEVERAL COMPLEXES TO OUR WEST WILL TRY TO MOVE EAST...BUT MAY ALSO BE SHUNTED SOUTH ALONG A BOUNDARY...CREATING A GOOD DEAL OF UNCERTAINTY. HAVE SOME MVFR AND VCTS TRYING TO TIME THESE...BUT COULD BE OFF A BIT AND WOULD NOT BE SURPRISED TO GET PERIODS OF IFR IN HEAVIER RAIN. BEST CHANCE OF SHOWERS/STORMS THIS EVENING AND TONIGHT WILL BE ACROSS THE SOUTH. ALSO PUT IN SOME MVFR FOG BEHIND TONIGHTS BATCH OF SHOWERS...AGAIN MAINLY ACROSS THE SOUTH. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS COULD VARY. FOG COULD FORM IN AREAS RECEIVING RAINFALL TUESDAY NIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H M H H HTS CONSISTENCY M H M H H H H H M M M M BKW CONSISTENCY H H H H H M H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY M M M M M M M M M H M M CKB CONSISTENCY H H H H H M H M M M M M AFTER 18Z WEDNESDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR WVZ005-006- 013>015-024>026-033>036. OH...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR OHZ087. KY...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR KYZ101>103-105. VA...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...ARJ/JMV/MZ NEAR TERM...MZ SHORT TERM...JMV LONG TERM...ARJ AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
233 PM EDT TUE APR 7 2015 .SYNOPSIS... A WARM AND MOIST SOUTH TO SOUTHWEST WIND FLOW WILL BRING ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK. COLD FRONT CROSSES AT THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... LOTS OF CONVECTION TO OUR WEST...WITH ONLY LINGERING MASS ACROSS THE NORTHERN MOUNTAINS. TO OUR WEST...HAVE AREA BETWEEN KHTS AND KLEX...MOVING SOUTHEAST ALONG A WEAK SURFACE BOUNDARY. THIS CONVECTION WILL MOVE ACROSS THE SOUTHERN CWA LATE THIS AFTERNOON INTO THIS EVENING. FARTHER WEST...IN SOUTHERN INDIANA HAVE ANOTHER COMPLEX MOVING EAST. NAM/HRRR AND SOME WRF RUNS SHOW A MCV WITH THIS MOVING ACROSS SOUTHERN CWA TONIGHT. RAP IS A BIT FARTHER NORTH. AS A SURFACE LOW MOVES THROUGH MISSOURI TONIGHT...EXPECT THE SURFACE BOUNDARY TO SLOWLY MOVE NORTH CROSSING SOUTHERN CWA DURING THE EARLY MORNING. WITH A FAIRLY WET GROUND IN PLACE ACROSS SOUTHERN CWA AFTER HEAVY RAIN LATE LAST WEEK...AND ANTICIPATING ANOTHER COUPLE ROUNDS OF AT LEAST MODERATE RAIN TONIGHT...WITH GO WITH A FLASH FLOOD WATCH ALONG AND SOUTH OF I-64. BEST CASE SCENARIO IS THE HEAVIEST RAIN STICKS CLOSER TO THE INFLOW AND REMAINS MAINLY SOUTH OF CWA...WITH JUST A PERIOD OF LIGHT TO MODERATE RAIN WITH THE REMNANTS OF THE MCV. WORST CASE WOULD BE IF EACH WAVE CROSSES THROUGH THE SAME AREA OF SOUTHERN CWA. EXPECT A BREAK IN PRECIP...ALTHOUGH CANNOT RULE OUT AN ISOLATED SHOWER...THROUGH MUCH OF WEDNESDAY MORNING. HAVE ANOTHER AREA OF LIKELY POPS MOVING FROM WEST TO EAST ACROSS CWA WEDNESDAY AFTERNOON AS A SHORTWAVE TROUGH MOVES OVER. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... STILL TRYING TO HONE IN ON WHICH PERIODS ARE MOST ACTIVE IN THIS UNSETTLED WEEK. THE FIRST IMPULSE WITH MOST AGREEMENT IS WEDNESDAY MORNING ACROSS SE OH AND N WV WITH A MORE ROBUST ONE SLATED FOR WEDNESDAY AFTERNOON ACROSS MUCH OF THE AREA. A BREAK WEDNESDAY EVENING BEFORE CONVECTION GETS GOING ONCE AGAIN...THIS TIME ALONG A NEW WARM FRONTAL BOUNDARY WHICH WILL SLIDE OFF TO N THURSDAY MORNING. ATTENTION THEN TRIES TO FOCUS MORE ALONG DEVELOPING LOW PRESSURE AND AMPLIFYING UPPER TROF ACROSS THE MIDWEST WHICH MAY ALLOW FOR A BRIEF RESPITE FROM THE MORE WIDESPREAD CONVECTION...SAVE FOR PERHAPS SE OH. THUS THURSDAY MAY BE OUR WARMEST THIS WEEK. TREND IS FOR A MORE AMPLIFIED SYNOPTIC PATTERN WITH THE UPPER TROF...THUS A FASTER FROPA...NOW SLATED FOR FRIDAY WITH ANOTHER ROUND OF CONVECTION. THINGS DRY OUT FRIDAY NIGHT WITH THE WEEKEND SHAPING UP TO BE RATHER NICE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MODELS ARE QUICKER WITH THE COLD FRONTAL PASSAGE ON FRIDAY LEAVING FRIDAY NIGHT MOSTLY DRY. THE OUTLIER IS THE ECMWF WHICH LAGS ABOUT 6 HOURS IN ITS QPF FIELD. WENT WITH THE CONSENSUS OF MODELS WITH A FASTER SOLUTIONS. HIGH PRESSURE BRINGS WIDESPREAD DRY WEATHER FRIDAY NIGHT THROUGH THE WEEKEND. ANOTHER UPPER WAVE APPROACHES MONDAY BRINGING BACK CHANCES FOR PCPN ACROSS THE AREA. TEMPERATURES EXPECTED TO BE WARM REACHING THE UPPER 70S THROUGH THE PERIOD...EXCEPT FOR A SLIGHT COOL DOWN BEHIND THE COLD FRONT SATURDAY...GENERALLY IN THE MID TO UPPER 60S. WENT CLOSE TO WPC GUIDANCE WITH FEW TWEAKS THROUGH THE PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... MESSY SITUATION WITH SHOWERS AND SOME THUNDERSTORMS DRIFTING MAINLY EASTWARD ACROSS CWA. SEVERAL COMPLEXES TO OUR WEST WILL TRY TO MOVE EAST...BUT MAY ALSO BE SHUNTED SOUTH ALONG A BOUNDARY...CREATING A GOOD DEAL OF UNCERTAINTY. HAVE SOME MVFR AND VCTS TRYING TO TIME THESE...BUT COULD BE OFF A BIT AND WOULD NOT BE SURPRISED TO GET PERIODS OF IFR IN HEAVIER RAIN. BEST CHANCE OF SHOWERS/STORMS THIS EVENING AND TONIGHT WILL BE ACROSS THE SOUTH. ALSO PUT IN SOME MVFR FOG BEHIND TONIGHTS BATCH OF SHOWERS...AGAIN MAINLY ACROSS THE SOUTH. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS COULD VARY. FOG COULD FORM IN AREAS RECEIVING RAINFALL TUESDAY NIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H M H H HTS CONSISTENCY M H M H H H H H M M M M BKW CONSISTENCY H H H H H M H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY M M M M M M M M M H M M CKB CONSISTENCY H H H H H M H M M M M M AFTER 18Z WEDNESDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS THROUGH FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR WVZ005-006- 013>015-024>026-033>036. OH...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR OHZ087. KY...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR KYZ101>103-105. VA...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...ARJ/MZ/30 NEAR TERM...MZ SHORT TERM...30 LONG TERM...ARJ AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1036 AM EDT TUE APR 7 2015 .SYNOPSIS... A WEST-TO-EAST ORIENTED FRONTAL BOUNDARY WILL MEANDER NEAR THE AREA THROUGH THURSDAY NIGHT AND WILL LEAD TO OCCASIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE THROUGH LATE THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE WILL THEN WORK INTO THE REGION FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOW CONFIDENCE FORECAST TODAY INTO THIS EVENING IN LOW AMPLITUDE/WEAKLY FORCED REGIME. 07.12Z KILN RAOB SAMPLED ELEVATED INSTBY /500 J/KG/ ATOP A STABLE BOUNDARY LAYER. WHILE BULK SHEAR VALUES ARE IMPRESSIVE - EFFECTIVE SHEAR /WHAT UPDRAFTS ARE TRULY FEELING/ IS QUITE WEAK THUS SHOWERS/STORMS HAVE BEEN WEAK/MODERATE IN INTENSITY. 25-35KTS OF WSWLY FLOW ABOVE THE BOUNDARY LAYER CONTINUES MOISTURE TRANSPORT/ISENTROPIC ASCENT THIS MORNING AND IS PROGGED BY RAP/HRRR TO SLOWLY MIX OUT/WEAKEN AS THE FLOW BACKS SOMEWHAT. STRONG E-W FRONTAL ZONE WILL CONTINUE TO BE REINFORCED ACRS CNTL OH/IND WITH FRIGID LAKE ERIE WATERS AND NORTHEAST WINDS THRU NRN OH REALLY ENHANCING BAROCLINICITY TO THIS FRONT. BY MID AFTN EXPECT TEMPS TO RANGE ONLY IN THE MID 40S IN FAR NORTHERN FORECAST AREAS TO 60S AND POSSIBLY 70 IN THE FAR. DEGREE OF WARMING IS VERY MUCH IN QUESTION ALL AREAS...AS AMPLE CLOUDS ARE IN PLACE /MANY CIGS AT OR BELOW 1KFT/ WHICH MAKES WARMING DIFFICULT. IN ADDITION ANVIL BLOWOFF FROM KY/MO CONVECTION WILL ADD ADDITIONAL MID/HIGH LEVEL MOISTURE THROUGH THE DAY. SO HAVE BROUGHT TEMPS BACK A LITTLE BIT FROM PVS FORECAST. WATCHING TWO CLUSTERS OF STORMS RIGHT NOW...ONE NEAR LOUISVILLE WHICH IS WEAKENING AND A MORE POTENT/ORGANIZED MCS NEAR ST. LOUIS. EXPECT BOTH CONVECTIVE SYSTEMS TO DIVE SOUTHEAST INTO BETTER INSTBY/MOISTURE TRANSPORT...AND REMAIN MOSTLY SOUTH OF THE AREA. THUS...EXPECT A GENERAL DECREASE IN RAIN CHANCES THROUGH THE DAY THOUGH SHRA/TSRA AREN/T EXPECTED TO TOTALLY DISSIPATE. ISLD-SCT ACTIVITY TO LIKELY CONTINUE IN THE BROAD MOIST/WARM ADVECTION. AGREE WITH 13Z SPC UPDATE TO REMOVE MARGINAL SVR THREATS FROM OUR SOUTH...THOUGH PROXIMITY TO BETTER INSTBY IS IN OUR SOUTHWEST SO CAN/T RULE OUT A STRONGER STORM OR TWO IN OUR FAR SOUTHWEST LATER THIS AFTN DEPENDING ON HOW MO/IL CONVECTION EVOLVES. THIS IN LINE WITH RATHER STABLE HRRR RUNS OVER THE PAST FEW HOURS DEPICTING CONVECTIVE EVOLUTION FROM MO/IL THROUGH KY WITH MORE ISOLD/SCT ACTIVITY FURTHER NORTH INTO OHIO AND NEAR THE STATIONARY FRONT. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... DISTURBANCE WILL MOVE TO THE EAST THIS EVENING. THIS WILL ALLOW FOR A DECREASE IN PRECIPITATION CHANCES. BEST CHANCE FOR PRECIPITATION TONIGHT WILL BE ACROSS NORTHERN PORTIONS OF THE FA CLOSER TO THE FRONTAL BOUNDARY. AGAIN THERE WILL BE A SHARP GRADIENT IN TEMPERATURES NORTH AND SOUTH OF THE BOUNDARY. NORTHERN PORTIONS OF THE FA WILL DROP DOWN INTO THE 40S WHILE SOUTHERN PORTIONS OF THE FA WILL BE IN THE 60S. FRONTAL BOUNDARY WILL PUSH JUST NORTH OF THE FA ON WEDNESDAY. SOUTHERLY FLOW WILL ALLOW FOR TEMPERATURES ACROSS THE FA TO RISE INTO THE 60S AND 70S. ANOTHER DISTURBANCE WILL WORK THROUGH THE REGION BRINGING ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY TO THE AREA. A COUPLE MORE ROUNDS OF THUNDERSTORMS ARE EXPECTED TO MOVE THROUGH WEDNESDAY NIGHT INTO THURSDAY MORNING AND THEN AGAIN THURSDAY AFTERNOON. SOUTHERLY FLOW PICKS UP FOR THURSDAY WITH GUSTY WINDS AROUND 30 TO 35 MPH. THIS WILL ALLOW FOR TEMPERATURES TO BE IN THE 70S ACROSS MOST OF THE AREA AND A FEW LOCATIONS NEAR 80 ACROSS FAR SE PORTIONS OF THE FA. A COLD FRONT WILL MOVE THROUGH LATE THURSDAY NIGHT INTO FRIDAY MORNING ALLOWING FOR COOLER TEMPERATURES TO MOVE INTO THE AREA. PRECIPITATION WILL TAPER OFF DURING THE MORNING HOURS ON FRIDAY AFTER THE FRONTAL PASSAGE. GUSTY WINDS ARE AGAIN EXPECTED DURING THE DAY ON FRIDAY. WITH THE DECREASE IN CLOUD COVER FRIDAY NIGHT AND THE COOL AIRMASS IN PLACE...EXPECT TEMPERATURES TO DROP DOWN INTO THE 30S AND 40S FRIDAY NIGHT. WITH SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS THERE IS THE POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES. ALSO...ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED AT THIS TIME CANNOT RULE OUT ISOLATED STRONG TO SEVERE STORMS THE NEXT FEW DAYS. && .LONG TERM /SATURDAY THROUGH MONDAY/... SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO THE AREA. COOLER WEATHER WILL RETURN WITH HIGHS RANGING FROM THE MID 50S NORTH THE LOWER 60S SOUTH ON SATURDAY. FOR SUNDAY INTO MONDAY...HIGH PRESSURE IS FORECAST TO MOVE EAST. A WARM FRONT WILL LIFT TOWARD THE OHIO VALLEY BY SUNDAY NIGHT. THEREAFTER...A COLD FRONT WILL APPROACH THE REGION FROM THE WEST LATE MONDAY. WITH RETURN...MOIST FLOW...THE THREAT FOR SHOWERS/STORMS WILL ONCE AGAIN INCREASE. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS ONCE AGAIN. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... INITIAL ROUND OF CONVECTION WILL MOVE EAST OF THE TERMINALS EARLY IN THE TAF PERIOD. EXPECT IFR CEILINGS TO SPREAD IN BEHIND THIS ACTIVITY EXCEPT IN THE COLUMBUS AREA WHERE IT MAY REMAIN MVFR. QUITE A BIT OF UNCERTAINTY WHERE AND WHEN ADDITIONAL SHOWERS AND THUNDERSTORMS WILL OCCUR THROUGH THE DAY. HAVE USED VCTS TO INDICATE TIMES WHEN CHANCE APPEARS HIGHER AND WILL AMEND TO INCLUDE A TEMPO GROUP AS WARRANTED. CEILINGS WILL LIFT SOMEWHAT THROUGH THE DAY ALTHOUGH IT DOES APPEAR THAT CEILINGS WILL REMAIN MVFR THROUGHOUT. THERE COULD BE SOME BREAKS IN THE CLOUDS AROUND 00Z BUT THESE ARE EXPECTED TO FILL IN OVERNIGHT. CEILINGS WILL LOWER ONCE AGAIN WITH BOUNDARY LAYER COOLING AND PREVAILING IFR CEILINGS LOOK POSSIBLE BY LATE IN THE PERIOD. A FRONT WILL SAG SOUTH TODAY BEFORE STALLING AND LIFTING BACK NORTH TONIGHT. SOME UNCERTAINTY HOW FAR SOUTH THIS GETS BUT IT SEEMS LIKELY THAT KDAY TO KCMH/KLCK TERMINALS WILL HAVE A WIND SHIFT. BUT WIND SPEEDS WILL BE LESS THAN 10 KT. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE LIKELY WEDNESDAY MORNING. THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...BINAU SHORT TERM...NOVAK LONG TERM...HICKMAN AVIATION...
AREA FORECAST DISCUSSION
NWS TULSA OK
322 PM CDT TUE APR 7 2015 .DISCUSSION... A WEAK FRONTAL BOUNDARY EXTENDS FROM WEST OF KANSAS CITY INTO NW OKLAHOMA THIS AFTERNOON WITH A VERY UNSTABLE BUT STRONGLY CAPPED AIRMASS RESIDING OVER EASTERN OK AND NORTHWEST AR. TEMPS ALONG AND SE OF THE FRONT HAVE WARMED INTO THE MID 80S TO NEAR 90...AND ALSO A SUBTLE OUTFLOW BOUNDARY FROM EARLIER STORMS PUSHING THROUGH SW MISSOURI AT THIS TIME. NO SIGNIFICANT UPPER AIR FORCING AT THIS POINT...BUT ISOLATED STORMS STILL MAY DEVELOP NEAR THE SFC FRONT AND OUTFLOW BOUNDARY LATER THIS AFTERNOON OR EARLY THIS EVENING AS HRRR AND TO A LESSER EXTENT OUR LOCALLY RUN 5KM WRF CONTINUE TO INDICATE. GIVEN THE AMOUNT OF AVAILABLE CAPE AND AT LEAST MODERATE SHEAR ANY STORMS COULD BECOME SEVERE SHOULD UPDRAFTS BE SUSTAINED... LARGE HAIL AND WINDS THE MAIN THREATS. CAP WILL REMAIN WITH US FOR THE MOST PART THROUGH TONIGHT WITH ONLY A LIMITED CHANCE OF STORMS NEAR KANSAS AND MISSOURI BORDERS. UNSTABLE AND CAPPED ENVIRONMENT REMAINS WITH US WEDNESDAY... HOWEVER WITH UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST MOVING INTO THE CENTRAL ROCKIES DURING THE DAY...MID LEVEL HEIGHT FALLS AND A POTENTIAL LEAD SHORT WAVE/ JET STREAK SHOULD HELP ERODE THE CAP ENOUGH FOR SOME STORMS TO DEVELOP ALONG THE DRY LINE FROM CENTRAL KS INTO NORTHERN OK. MOST LIKELY TIME WOULD BE 21-00Z HOWEVER EARLIER RUNS OF THE NAM HAVE SHOWN SOME EARLIER DEVELOPMENT THAN THAT. WIND PROFILES SUGGEST THAT ONCE A STORM DEVELOPS IT WILL QUICKLY BECOME SUPERCELLULAR AND POSE A THREAT FOR VERY LARGE GAIL AND DAMAGING WINDS...AND SOME DEGREE OF TORNADO POTENTIAL. OVERALL STORM COVERAGE IS EXPECTED TO REMAIN FAIRLY LIMITED THROUGH WED NIGHT DUE TO PERSISTENT CAP ISSUES. MAIN UPPER SYSTEM CONTINUES TO PROGRESS EAST THURSDAY WITH A COLD FRONT OVERTAKING THE DRY LINE AND LIKELY PUSHING THROUGH PARTS OF NE OKLAHOMA BY EARLY AFTERNOON. CONTINUED MOIST AND VERY UNSTABLE AHEAD OF THE FRONT WITH MORE WIDESPREAD THUNDERSTORMS LIKELY THU AFTERNOON AND EVENING MAINLY OVER SOUTHEAST OK AND NORTHWEST AR. SHEAR PROFILES SUGGEST A MORE LINEAR STORM MODE AT THIS TIME. STORMS WILL END THU EVENING WITH A COOLER AND STABLE AIRMASS SETTLING OVER THE AREA FRIDAY. ANOTHER UPPER LEVEL SYSTEM WILL MOVE IN FROM THE WEST BY THIS WEEKEND AND WITH THE PRESENCE OF A SFC BOUNDARY IN THE AREA... THUNDERSTORM CHANCES WILL RETURN BY SATURDAY AND CONTINUE INTO EARLY NEXT WEEK. GENERAL CONSENSUS IS THIS UPPER LOW WILL ULTIMATELY TACK A MUCH MORE SOUTHERLY TRACK...ANY SEVERE WEATHER THREATS DURING THIS TIME REMAIN EXTREMELY UNCERTAIN. && .PRELIMINARY POINT TEMPS/POPS... TUL 68 84 68 78 / 10 40 30 40 FSM 65 83 66 77 / 10 20 30 70 MLC 68 80 68 77 / 10 20 20 40 BVO 66 84 65 77 / 20 50 30 30 FYV 64 79 64 73 / 20 20 30 60 BYV 64 80 64 73 / 20 20 30 60 MKO 66 81 66 77 / 10 20 30 50 MIO 66 81 66 75 / 20 30 40 40 F10 67 83 67 78 / 10 20 20 40 HHW 65 79 66 77 / 10 10 30 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...06 LONG TERM....14
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1153 PM CDT MON APR 6 2015 .AVIATION...07/06Z TAF ISSUANCE... CEILINGS AND VISIBILITY REMAIN A CHALLENGE FOR SITES ACROSS SWRN AND POSSIBLY CENTRAL OK THIS MORNING. LATEST SHORT RANGE GUIDANCE SUGGEST VFR CONDITIONS WILL PREVAIL AND GIVEN CURRENT CONDITIONS... THIS SOLUTION SEEMS LIKELY. HOWEVER... THERE MAY BE A CHANCE OF LIGHT FOG... BUT MORE LIKELY LOW STRATUS CLOUDS ACROSS A NARROW CORRIDOR OF WRN OK WHERE WINDS RELAX SLIGHTLY AND TEMP/DEW POINT SPREADS LESSEN NEAR DAY BREAK. OVERALL... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD AT THIS TIME... BUT FEEL COMPELLED TO PUT IN A TEMPO FOR LIGHT 4SM BR AND MVFR CIGS AT KCSM/KHBR AROUND SUNRISE. SOUTH WINDS WILL REMAIN BREEZY OVERNIGHT... INCREASING TOMORROW LATE MORNING/AFTERNOON AS THE PRESSURE GRADIENT INCREASES AND A DRY LINE PUSHES EASTWARD INTO WRN OK/WRN N TX. GUSTS ACROSS WRN INTO CENTRAL OK COULD APPROACH 20 TO 25 KTS THROUGH THE AFTN. JTK && .PREV DISCUSSION... /ISSUED 714 PM CDT MON APR 6 2015/ UPDATE... UPDATE TEMPS... WEATHER... DISCUSSION... ADJUSTED ISOLATED THUNDER TO A MORE CONFINED AREA OF CENTRAL TO SWRN OK TO WRN N TX IN ACCORDANCE WITH THE SIGNIFICANT CLOUD COVER AND SPORADIC CUMULUS THAT HAS DEVELOPED ALONG THE DRY LINE SWRN OK. THE CHANCE FOR A FEW ISOLATED STORMS CANNOT BE RULED OUT THROUGH SUNSET... BUT THE CHANCE REMAINS VERY LOW. ADJUSTED TEMPS... BRINING THEM BACK IN LINE WITH OBS TREND AS CURRENT FORECAST WAS RUNNING A TAD COOLER ACROSS WRN OK... CONSIDERING THERE IS STILL UPPER 80S AND LOWER 90S IN THE TX PANHANDLE. JTK PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 6 2015/ DISCUSSION... CONVECTION... THE HRRR AND RAP HAVE SHOWN A RELATIVELY CONSISTENT SIGNAL OF ISOLATED STORM/S/ DEVELOPING IN THE SOUTHWEST LATE THIS AFTERNOON. MESOANALYSIS SHOW CONVECTIVE INHIBITION DECEASING ACROSS NORTHWEST TEXAS. IT IS NOT A SURE THING THAT ANY STORM WILL DEVELOP AND COVERAGE WILL BE LIMITED IF STORMS DO DEVELOP. BUT THERMODYNAMIC PROFILE SHOWS QUITE AN UNSTABLE ATMOSPHERE... SO SEVERE WEATHER WOULD BE LIKELY IF A STORM DOES INDEED DEVELOP. WILL KEEP POPS BELOW 20 BUT ADD ISOLATED THUNDER IN THE WEATHER GRIDS IN TO COVER THE POTENTIAL DEVELOPMENT. MUCH THE SAME SCENARIO IS EXPECTED TOMORROW WITH AN UNSTABLE BUT GENERALLY CAPPED ATMOSPHERE WITHOUT SIGNIFICANT FORCING... BUT CONVECTIVE INHIBITION DECREASES ENOUGH THAT ISOLATED STORMS ARE POSSIBLE AGAIN IN THE LATE AFTERNOON AND EARLY EVENING. WEDNESDAY STILL LOOKS TO HAVE A MORE SIGNIFICANT SEVERE WEATHER POTENTIAL AS THE TROUGH THAT IS CURRENTLY LOCATED OFF THE PACIFIC COAST MOVES TOWARD THE HIGH PLAINS. WE EXPECT STORMS TO DEVELOP WEDNESDAY AFTERNOON OR EVENING NEAR THE DRYLINE AND SPREAD EAST WITH A DECENT CHANCE OF SEVERE WEATHER. THE STORM CHANCES WILL LINGER INTO THURSDAY IN THE SOUTHEAST UNTIL THE SURFACE FRONT MOVES THROUGH. AFTER A BRIEF RESPITE FRIDAY...ANOTHER UPPER TROUGH APPROACHES THIS WEEKEND INCREASING STORM CHANCES AGAIN THIS WEEKEND. EVEN AS THE FIRST TROUGH MOVES BY THE PLAINS... THE MEAN TROUGH WILL PERSIST IN THE WEST ALLOWING CONTINUED STORM CHANCES THROUGH MONDAY. FIRE WEATHER... GUSTY POST-DRYLINE WINDS HAVE SPREAD INTO NORTHWESTERN OKLAHOMA ALONG WITH TEMPERATURES IN THE LOWER 90S AND HUMIDITY IN THE SINGLE DIGITS AND TEENS.... SO THE CURRENT RED FLAG WARNING LOOKS GOOD INTO THE EARLY EVENING. ALTHOUGH WE WILL HAVE THE HEAT AND LOW HUMIDITY AGAIN TOMORROW... WINDS ARE EXPECTED TO BE LIGHTER. WINDS LOOK HIGHER AGAIN ON WEDNESDAY SO THE FIRE WEATHER WATCH IS STILL VALID. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 65 84 66 82 / 10 20 20 30 HOBART OK 60 87 64 86 / 10 10 10 20 WICHITA FALLS TX 66 87 66 88 / 10 20 10 30 GAGE OK 53 88 53 85 / 10 0 10 10 PONCA CITY OK 63 87 64 85 / 10 20 20 40 DURANT OK 68 80 68 81 / 10 10 10 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR OKZ004>006-009>011-014>016-021-022-033>037. TX...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR TXZ083>085-087-088. && $$ 99/99/01
AREA FORECAST DISCUSSION
NWS PORTLAND
224 PM PDT TUE APR 7 2015 .SYNOPSIS...A LOW PRES MOVING INTO NORTHERN CALIFORNIA WILL TRACK EAST INTO NORTHERN NV LATE TONIGHT AND WEDNESDAY. ANOTHER WEAK TROUGH OF LOW PRES ALOFT WILL MOVE S OVER EASTERN WA AND OREGON WED AS A SURFACE RIDGE OF HIGH PRES STRENGTHENS ALONG THE COAST. THE HIGH WILL MOVE INLAND WED NIGHT AND THU. THE NEXT PACIFIC FRONTAL SYSTEM IS EXPECTED TO MOVE DOWN FROM THE GULF OF AK AND PUSH INLAND FRI AND FRI NIGHT FOR MORE LOWLAND RAIN AND CASCADE SNOW FOR THE WEEKEND. && .SHORT TERM...A VERTICALLY STACKED UPPER LOW JUST MAKING LANDFALL ON THE NORTH CALIFORNIA COAST THIS AFTERNOON AND CONTINUES TO MOVE SLOWLY EAST-SOUTHEAST INTO NORTHERN CALIFORNIA. THE FRONT FROM LAST NIGHT CONTINUES TO DISSIPATE OVER THE NORTHERN ZONES. THE NEXT FRONT IS ROTATING AROUND THE SE QUADRANT OF THE LOW IN NRN CALIFORNIA. THE FRONT LOOKS LIKE IT WILL SWING INTO THE CWA AS A DEFORMATION ZONE AND STALL SOMEWHERE NEAR OVER THE SE ZONES. THE CENTRAL OREGON CASCADES WILL PROBABLY RECEIVE THE MOST PCPN. THE GFS AND ECMWF HOLD THE HIGHER PCPN AMOUNTS OVER THE CASCADES OF LINN AND LANE COUNTIES. HOWEVER THIS MORNING RUNS OF THE HRRR AND NAM HAVE EXPANDED THE HIGH PCPN AMOUNTS CLOSER TO MT. HOOD. IN LIGHT OF THIS HAVE RAISED QPF FURTHER NORTH ALONG THE CASCADES FOR TONIGHT. SNOW LEVELS ARE HOVERING AROUND 4500 FEET AND WITH EXPECTED PCPN WILL CONTINUE WITH THE WINTER WEATHER ADVISORY FOR SNOW. THE GREATEST IMPACT SHOULD BE FOR CASCADES PASSES FROM AROUND MT. JEFFERSON TO WILLAMETTE PASS. SNOWFALL RATES WILL BE ON THE DECREASE EARLY WED MORNING AS THE LOW DEPARTS FURTHER TO THE EAST. MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED TO TAPER OFF LATE TONIGHT AS THE LOW MOVES OFF TO THE E...BUT ANOTHER TROUGH COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR SHOWERS GOING WED AFTERNOON AND EVENING. AN UNSTABLE LAYER IN THE LOW TO MID LEVELS WED AFTERNOON AS SEEN IN MODEL SOUNDINGS AT 00Z THU INDICATES MARGINALLY UNSTABLE LAYER DEEP ENOUGH TO SUPPPORT A SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED AFTERNOON. WILL ALSO CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS AGAIN THU AFTERNOON OVER THE CASCADES AS THE WEAK TROUGH REMAINS OVER THE AREA IN AT LEAST SOME MODELS. OTHERWISE RISING HEIGHTS SUGGESTS A WARMER DAY FOR THU AND FRI. /MH LONG TERM...FRIDAY NIGHT THROUGH MONDAY...RECENT MODEL RUNS HAVE SPED UP THE TIMING OF THE WEEKEND FRONT...AND SEEM TO BE SETTLING ON RAIN AND MOUNTAIN SNOW RETURNING TO THE PACIFIC NORTHWEST FRIDAY NIGHT.AN UPPER LEVEL TROUGH WILL MAINTAIN SHOWERS THROUGH THE WEEKEND...ALTHOUGH MOST OF THE SHOWERS WILL BE OVER THE HIGHER TERRAIN SUNDAY. SNOW LEVELS SHOULD BE AROUND 4000 FEET BEHIND THE FRONT...LATE FRIDAY NIGHT AND THEN GRADUALLY LOWER THROUGH THE WEEKEND TO AROUND 2500 FEET. TJ && .AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE SHORTLY. THIS SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL LIGHT RAIN SHOWERS AND MVFR CONDITIONS INTO THE OVERNIGHT HOURS. A BAND OF HEAVIER PRECIPITATION IS EXPECTED TO FORM OVER THE CENTRAL OREGON CASCADES AND MAY ALSO MOVE CLOSE ENOUGH TO KSLE AND KEUG TO BRING MVFR CONDITIONS TO THESE TERMINALS AFTER 00Z WEDNESDAY. KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 00Z THURSDAY. COULD SEE SOME MVFR CIGS OR VIS AROUND SUNRISE THURSDAY...BUT VFR CONDITIONS WOULD RETURN BY LATE MORNING. BOWEN && .MARINE...A WEAK LOW PRESSURE SYSTEM WILL COME ONSHORE SHORTLY NEAR THE OREGON/CALIFORNIA BORDER. AS THE LOW MOVES SOUTH AND OUT OF THE LOCAL AREA...WINDS WILL CONTINUE TO WEAKEN THIS EVENING. BUILDING HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING TRANQUIL WIND AND SEAS THROUGH THURSDAY NIGHT. A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT SOUTHERLY WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT WESTERLY WINDS IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT SWELL OVER THE WEEKEND. BOWEN/NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
239 PM PDT TUE APR 7 2015 .DISCUSSION...THE UPPER LOW CURRENTLY OFF THE COAST IN NORTHWEST CAL IS MOVING SOUTH. WET SNOW CONTINUES IN SISKIYOU COUNTY, BUT IT`S BECOMING SHOWERY AND ROADS ARE WET. THE MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING A DEFORMATION ZONE OF PRECIPITATION SETTING UP EAST OF THE CASCADES LATER THIS EVENING AND LASTING INTO WEDNESDAY MORNING, BUT DIFFER SLIGHTLY ON THE PLACEMENT OF THE CORE OF HEAVIEST QPF. THE LATEST HRRR SHOWS THE DEFORMATION ZONE WELL AND THE FORECAST FOR TONIGHT WILL LEAN TOWARDS THAT SOLUTION. GIVEN THAT THIS WILL SET UP AT NIGHT, THERE WILL BE AN OPPORTUNITY FOR SNOW TO ACCUMULATE ON ROADS DURING THE OVERNIGHT HOURS FOR MOST AREAS EAST OF THE CASCADES. THE CASCADES WILL ALSO GET ACCUMULATING SNOW TONIGHT, THUS HAVE EXTENDED THE END TIME OF THE WINTER WEATHER ADVISORY UNTIL WEDNESDAY MORNING. DETAILS CAN BE FOUND AT WSWMFR. GIVEN THE ABOVE MENTIONED SCENARIO, HAVE INCREASED POPS...QPF AND SNOW AMOUNTS SIGNIFICANTLY, BUT IT STILL MAY NOT BE ENOUGH. LATER SHIFTS MAY NEED TO TAKE ANOTHER LOOK AT THIS AND ADJUST AMOUNTS HIGHER IF LATER MODEL RUNS CONTINUE TO SHOW THE HIGHER QPF AMOUNTS. WEDNESDAY WILL BE A TRANSITION DAY WITH THE DEFORMATION ZONE WEAKENING IN THE MORNING. RAIN AND MOUNTAIN SNOW SHOWERS WILL CONTINUE IN THE AFTERNOON, BUT SNOW LEVELS WILL COME UP TO AROUND 5000 FEET IN THE AFTERNOON, SO NOT EXPECTING MUCH IF ANY ACCUMULATIONS FROM ABOUT MID MORNING WEDNESDAY ON DUE TO WARMING ROAD TEMPERATURES AND SPOTTY PRECIPITATION. DRY AND MILDER WEATHER FINALLY RETURNS THURSDAY AND CONTINUES INTO THURSDAY NIGHT WITH SHORTWAVE RIDGING BUILDING INTO THE AREA. MOST OF FRIDAY WILL BE DRY, THEN THE NEXT FRONT WILL REACH THE COAST TOWARDS FRIDAY EVENING. THE GFS AND NAM ARE SLOWER WITH THE ARRIVAL OF THE FRONT WHILE THE EC IS FASTER. FOR NOW WENT WITH A BLEND BETWEEN THE TWO, BUT THE UPPER FLOW IS WEST OT NORTHWEST WHICH NORMALLY LEADS TO QUICKER ARRIVAL TIMES OF FRONTS. -PETRUCELLI THE ACTIVE PATTERN CONTINUES IN THE LONG TERM WITH ANOTHER FRONTAL BOUNDARY MOVING INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM. THE EC IS A BIT FASTER TO PUSH THE FRONT INLAND ON SATURDAY COMPARED TO THE GFS BUT BOTH MODELS HAVE IT PUSHED THROUGH THE AREA BY LATE SATURDAY NIGHT. ZONAL FLOW WILL SET UP FOR SUNDAY AND THE GFS IS HINTING AT SOME UPSLOPE SHOWERS CONTINUING ALONG THE CASCADES THROUGH SUNDAY AFTERNOON. THERE MAY ALSO BE SOME LINGERING SHOWERS FOR THE NORTHERN PORTION OF THE CWA...MAINLY FROM THE UMPQUA DIVIDE NORTH. OTHERWISE, SUNDAY LOOKS TO BE THE DRIEST DAY, RELATIVELY, THROUGH THE EXTENDED TERM. BY MONDAY MORNING, THE MODELS ARE SLIGHTLY DIFFERENT IN THE TIMING AND STRENGTH OF THE NEXT SYSTEM TO MOVE THROUGH. THE GFS IS FASTER AND DEEPER WITH THE NEXT TROUGH, MEANING COOLER TEMPERATURES AND LOWER SNOW LEVELS COMPARED TO THE EC...WHICH IS SLOWER BY ABOUT 12 HOURS AND NOT AS DEEP WITH THE TROUGH. EITHER WAY, IT LOOKS LIKE UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE EXTENDED TERM. MND && .AVIATION...FOR THE 07/18Z TAF CYCLE...AS LOW PRESSURE MOVES INLAND TODAY EXPECT CONTINUED SHOWER ACTIVITY OVER THE. THEN TONIGHT SHOWERS WILL BECOME MORE CONCENTRATED FROM THE CASCADES EAST AND IN NORTHERN CALIFORNIA. WITH THESES SHOWERS EXPECT A MIX OF MVFR AND VFR CIGS ACROSS THE AREA TODAY WITH WIDESPREAD MOUNTAIN OBSCURATIONS. ISOLATED IFR IS EXPECTED IN SNOW SHOWERS MAINLY NEAR KMHS. THEN THIS EVENING THROUGH EARLY WEDNESDAY MORNING, EXPECT MAINLY MVFR CIGS WITH AREAS OF IFR FROM THE CASCADES EAST AS SNOW SHOWER DEVELOP. WEST OF THE CASCADES, ISOLATED TO SCATTERED SHOWERS ARE EXPECTED WITH A MIX OF VFR AND MVFR CIGS. THEN EXPECT INCREASING VFR LATE WEDNESDAY MORNING. /CC && .MARINE...UPDATED 1100 AM PDT TUESDAY APR 07 2015...WINDS AND SEAS WILL CONTINUE TO DIMINISH TODAY AS LOW PRESSURE MOVES INLAND. SEAS WILL BE A MIX OF SOUTH WIND CHOP AND WESTERLY SWELL THIS MORNING. THE SOUTHERLY WIND CHOP WILL DECREASE DURING THE DAY AND WESTERLY SWELL WILL BECOME DOMINANT. HIGH PRESSURE WILL THEN BUILD INTO THE WATERS TONIGHT INTO WEDNESDAY AND PERSIST THROUGH THURSDAY NIGHT. THEN A FRONT WILL MOVE INTO THE WATERS LATE FRIDAY FROM THE NORTHWEST. /CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 9 AM PDT WEDNESDAY FOR ORZ029>031-624-625. WINTER WEATHER ADVISORY UNTIL 9 AM PDT WEDNESDAY FOR ORZ027-028-617-621-623. CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 9 AM PDT WEDNESDAY FOR CAZ085-285. PACIFIC COASTAL WATERS...NONE. $$
AREA FORECAST DISCUSSION
NWS PORTLAND
132 PM PDT TUE APR 7 2015 .SYNOPSIS...A LOW PRES MOVING INTO NORTHERN CALIFORNIA WILL TRACK EAST INTO NORTHERN NV LATE TONIGHT AND WEDNESDAY. ANOTHER WEAK TROUGH OF LOW PRES ALOFT WILL MOVE INTO EASTERN WA AND OREGON WED AS A SURFACE RIDGE OF HIGH PRES STRENGTHENS ALONG THE COAST. THE HIGH WILL MOVE INLAND WED NIGHT AND THU. THE NEXT PACIFIC FRONTAL SYSTEM IS EXPECTED TO MOVE DOWN FROM THE GULF OF AK AND PUSH INLAND FRI AND FRI NIGHT FOR MORE LOWLAND RAIN AND MOUNTAIN SNOW THROUGH THE WEEKEND. && .SHORT TERM...A VERTICALLY STACKED UPPER LOW JUST MAKING LANDFALL ON THE NORTH CALIFORNIA COAST THIS AFTERNOON AND CONTINUES TO MOVE SLOWLY EAST-SOUTHEAST INTO NORTHERN CALIFORNIA. THE FRONT FROM LAST NIGHT CONTINUES TO DISSIPATE OVER THE NORTHERN ZONES...ROUGHLY FROM SALEM NORTHWARD. THE NEXT FRONT IS ROTATING AROUND THE SE QUADRANT OF THE LOW. THE FRONT LOOKS LIKE IT WILL SWING INTO THE CWA AS A DEFORMATION ZONE AND STALL SOMEWHERE NEAR OVER THE SE ZONES. THE CENTRAL OREGON CASCADES WILL PROBABLY RECEIVE THE MOST PCPN. THE GFS AND ECMWF HOLD THE HIGHER PCPN AMOUNTS OVER THE CASCADES OF LINN AND LANE COUNTIES. HOWEVER THIS MORNING RUNS OF THE HRRR AND NAM HAVE EXPANDED THE HIGH PCPN AMOUNTS CLOSER TO MT. HOOD. IN LIGHT OF THIS HAVE RAISED QPF FURTHER NORTH ALONG THE CASCADES FOR TONIGHT. SNOW LEVELS ARE HOVERING AROUND 4500 FEET AND WITH EXPECTED PCPN WILL CONTINUE WITH THE WINTER WEATHER ADVISORY FOR SNOW TONIGHT. THE GREATEST IMPACT WILL BE FOR CASCADES PASSES FROM AROUND MT. JEFFERSON TO WILLAMETTE PASS. SNOW FALL RATES WILL BE ON THE DECREASE EARLY WED MORNING AS THE LOW DEPARTS FURTHER TO THE EAST. MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED TO TAPER OFF LATE TONIGHT AS THE LOW MOVES OFF TO THE E...BUT ANOTHER TROUGH COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR SHOWERS GOING WED AFTERNOON AND EVENING. AN UNSTABLE LAYER IN THE LOW TO MID LEVELS WED AFTERNOON AS SEEN IN MODEL SOUNDINGS AT 00Z THU INDICATES MARGINALLY UNSTABLE LAYER DEEP ENOUGH TO SUPPORT A SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED AFTERNOON. WILL ALSO CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS AGAIN THU AFTERNOON OVER THE CASCADES AS THE WEAK TROUGH REMAINS OVER THE AREA IN AT LEAST SOME MODELS. OTHERWISE RISING HEIGHTS SUGGESTS A WARMER DAY FOR THU AND FRI. /MH LONG TERM...FRIDAY NIGHT THROUGH MONDAY...RECENT MODEL RUNS HAVE SPED UP THE TIMING OF THE WEEKEND FRONT...AND SEEM TO BE SETTLING ON RAIN AND MOUNTAIN SNOW RETURNING TO THE PACIFIC NORTHWEST FRIDAY NIGHT.AN UPPER LEVEL TROUGH WILL MAINTAIN SHOWERS THROUGH THE WEEKEND...ALTHOUGH MOST OF THE SHOWERS WILL BE OVER THE HIGHER TERRAIN SUNDAY. SNOW LEVELS SHOULD BE AROUND 4000 FEET BEHIND THE FRONT...LATE FRIDAY NIGHT AND THEN GRADUALLY LOWER THROUGH THE WEEKEND TO AROUND 2500 FEET. TJ && .AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE THIS EVENING. THIS SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL LIGHT RAIN SHOWERS MVFR CONDITIONS ALONG THE COAST...PARTICULARLY AT KONP. IN ADDITION...WEAK NORTHERLY FLOW IN THE SOUTHERN WILLAMETTE VALLEY WILL PRODUCE IFR AND MVFR CONDITIONS AT KEUG THIS MORNING. A BAND OF HEAVIER PRECIPITATION IS EXPECTED TO FORM OVER THE CENTRAL OREGON CASCADES AND MAY ALSO MOVE CLOSE ENOUGH TO KSLE AND KEUG TO BRING MVFR CONDITIONS TO THESE TERMINALS AFTER 00Z WEDNESDAY. THERE IS SOME CHANCE THIS BAND OF PRECIP WILL MOVE NORTH AND AFFECT THE PDX AREA TERMINALS LATE THIS AFTERNOON AND EVENING. KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 12Z WEDNESDAY. MODELS ARE STARTING TO SHOW A BAND OF SHOWERS NEAR THE TERMINAL LATE THIS AFTERNOON AND EVENING WHICH COULD PRODUCE MVFR CONDITIONS FOR A NUMBER OF HOURS. BOWEN/NEUMAN && .MARINE...A WEAK LOW PRESSURE SYSTEM WILL SLOWLY DRIFT SOUTHWARD THIS MORNING AND PUSH ASHORE NEAR THE CALIFORNIA/OREGON BORDER LATE TODAY. THIS WILL RESULT IN WEAKENING WINDS THROUGH THE MORNING HOURS AND WINDS AT BUOY 29 ARE ALREADY DECREASING. BUILDING HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING MORE TRANQUIL WIND AND SEAS THROUGH THURSDAY NIGHT. A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT SOUTHERLY WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT WESTERLY WINDS IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT SWELL OVER THE WEEKEND. HIGH PRESSURE LOOKS TO RETURN LATE IN THE WEEKEND BEFORE ANOTHER SIMILAR STORM SYSTEM ARRIVES EARLY NEXT WEEK...AND POSSIBLY PUSHES SEAS WELL ABOVE 10 FT ONCE AGAIN. BOWEN/NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 3 AM PDT WEDNESDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
919 AM PDT TUE APR 7 2015 .DISCUSSION...CURRENT IR IMAGE SHOWS THE UPPER LOW STARTING TO MOVE INLAND IN NORTHERN CAL. AHEAD OF THE LOW IS A BAND OF MODERATE TO HEAVY PRECIPITATION ORIENTATED FROM SOUTHEAST TO NORTHWEST INTO SISKIYOU COUNTY. MODERATE TO HEAVY SNOW HAS FALLEN IN THE MOUNT SHASTA REGION INCLUDING MOUNT SHASTA CITY...TENNANT AND IN WESTERN SISKYIOU COUNTY ABOVE 3000 FEET. SPOTTER REPORTS HAVE BEEN COMING IN THIS MORNING AND THE BIG WINNER SO FAR HAS BEEN 13.5 INCHES 6 MILES WEST OF BLACK BUTTE SUMMIT...7 INCHES AT BLACK BUTTE SUMMIT...6 INCHES 2 MILES WEST OF WEED AND 5 INCHES NEAR THE WEST SHORE OF IRON GATE LAKE. ROAD CAMS THIS MORNING SHOW SNOW COVERED ROADS ALONG I-5 JUST SOUTH OF WEED TO DUNSMUIR...HIGHWAY 89 AND HIGHWAY 97. SNOW IS EXPECTED TO CONTINUE THIS MORNING, BUT THE MODELS SUGGEST SNOW WILL GRADUALLY DECREASE THIS AFTERNOON. THIS ALONG WITH WARMING ROAD TEMPERATURES SHOULD ALLOW ROADS TO BECOME WET IN THE AFTERNOON. CURRENT WINTER STORM WARNING GOES OUT UNTIL 5 PM PDT, BUT WE COULD END THIS EARLIER IF THERE`S ENOUGH EVIDENCE TO SUGGEST WE`LL NO LONGER HAVE ANY ROAD SNOW CONCERNS. THE NAM AND HRRR SHOWS PRECIPITATION INCREASING ALONG THE CASCADES THIS AFTERNOON AND LASTING INTO THIS EVENING WITH SNOW LEVELS HOVERING AROUND 4000 FEET, BUT COULD BRIEFLY LOWER TO 3500 FEET IN HEAVIER SHOWERS. MOST ROADS ARE WET IN THIS AREA EXCEPT FOR CRATER LAKE AND DIAMOND LAKE, BUT SLUSH OR SNOW COVERED ROADS ARE POSSIBLE THIS AFTERNOON AS PRECIP RATES INCREASE. MADE A FEW ADJUSTMENTS TO THE FORECAST TODAY, BUT THE OVERALL IDEA REMAINS THE SAME. -PETRUCELLI && .AVIATION...FOR THE 07/12Z TAF CYCLE...STRONG LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS NORTHERN CALIFORNIA THIS MORNING. THIS WILL RESULT IN HEAVY SNOW OVER THE MOUNTAINS AND RAIN IN THE LOWER ELEVATIONS WITH WIDESPREAD IFR CONDITIONS AND MOUNTAIN OBSCURATIONS SPREADING WEST TO EAST ACROSS NORTHERN CALIFORNIA. IN OREGON, WEST SIDE RAIN SHOWERS AND EAST SIDE SNOW SHOWERS WITH MVFR CIGS WILL BE COMMON AS WILL MOUNTAIN OBSCURATIONS. DOWNSLOPING WILL LIKELY KEEP RAIN FROM REACHING KMFR UNTIL AROUND DAWN, BUT THIS WILL ALSO RESULT IN LOW LEVEL WIND SHEAR AT KMFR EARLY THIS MORNING. -SVEN && .MARINE...UPDATED 350 AM PDT TUESDAY APR 07 2015... LOW PRESSURE AND A COLD FRONT WILL MOVE INLAND TODAY. BOTH WINDS AND SEAS WILL DIMINISH THIS MORNING AS LOW PRESSURE MOVES INLAND. HIGH PRESSURE WILL THEN BUILD IN WEDNESDAY AND PERSIST THROUGH FRIDAY WITH WEAK WINDS AND LIGHT TO MODERATE WESTERLY SWELL. && .PREV DISCUSSION... /ISSUED 355 AM PDT TUE APR 7 2015/ DISCUSSION...OBSERVATIONS OVER THE PAST SEVERAL HOURS HAVE SHOWN A STEADY RAIN ALONG THE COAST, PARTICULARLY AT BROOKINGS AND CRESCENT CITY, AND INLAND TO THE COASTAL RANGES AND THE SISKIYOU MOUNTAINS. THIS BAND OF HEAVIER PRECIPITATION WILL PUSH INLAND THROUGH THIS MORNING, ALTHOUGH PROGRESSION WILL BE SLOW AS THE SURFACE LOW WILL BEGIN TO WEAKEN AND MEANDER ABOUT A BIT BEFORE IT FINALLY MOVES ONSHORE AND ALMOST COMPLETELY DISSIPATES. WITH SNOW LEVELS HOVERING BETWEEN 3000 AND 4000 FEET, HEAVY SNOW AMOUNTS ARE STILL EXPECTED OVER MANY PORTIONS OF NORTHERN CALIFORNIA TODAY. WINTER WEATHER HEADLINES WILL CONTINUE THERE, ALTHOUGH WITH THE LATEST MODEL SOLUTIONS SUGGESTING THE SYSTEM IS SLOWING A BIT, HAVE EXTENDED THE WARNINGS AND ADVISORIES IN SISKIYOU COUNTY BY AN ADDITIONAL SIX HOURS. THOSE SAME MODELS ARE ALSO SHOWING AN AREA OF HEAVIER PRECIPITATION PUSHING NORTH ALONG THE CASCADES OF OREGON. AS MANY OF THE HIGHER RESOLUTION MODELS, AS WELL AS THE GFS, ARE DEPICTING THIS TREND, HAVE PUSHED QPF UP ALONG THE CASCADES, AND CONSEQUENTIALLY, HAVE BUMPED UP SNOW AMOUNTS AS WELL. THIS HAS RESULTED IN SNOW ACCUMULATIONS APPROACHING 6 INCHES OVER A PERIOD OF ABOUT 12 HOURS THIS AFTERNOON NEAR CRATER AND DIAMOND LAKES, AS WELL AS NEAR LAKE OF THE WOODS AND MT ASHLAND, SO HAVE DECIDED TO ISSUE A WINTER WEATHER ADVISORY TO COVER THE POSSIBLE TRAVEL DIFFICULTIES ALONG THE CASCADE PASSES. FOR MORE INFORMATION REGARDING THIS ADVISORY AND THE WARNING AND ADVISORIES FOR SISKIYOU COUNTY, SEE THE WINTER WEATHER MESSAGE. SNOW IS ALSO EXPECTED TODAY ACROSS MUCH OF THE EAST SIDE. SNOW AMOUNTS SHOULD BE LIGHT, AND GIVEN THE WARM SURFACE TEMPERATURES, DO NOT EXPECT SIGNIFICANT ACCUMULATIONS ON AREA ROADS. HOWEVER, WINDS MAY RESULT IN BRIEF PERIODS OF LOWERED VISIBILITIES IN BLOWING SNOW. THIS IS ALSO TRUE FOR THE SHASTA VALLEY TODAY, WHERE GUSTY WINDS AND SNOW COULD RESULT IN GREATLY LOWERED VISIBILITIES ALONG INTERSTATE 5. THE SURFACE LOW, AND ITS ASSOCIATED TROUGH, WILL SLIDE EAST OUT OF THE AREA LATE TONIGHT AND INTO WEDNESDAY MORNING. ISOLATED TO SCATTERED SHOWERS ARE LIKELY TO LINGER IN THE AREA THROUGH THE EARLY AFTERNOON, BUT MOST OF THE FORECAST AREA WILL SEE THE END OF PRECIPITATION BY LATE MORNING. A BRIEF PERIOD OF RIDGING WILL HELP TO BRING WARMER TEMPERATURES AND DRY CONDITIONS TO THE REGION THURSDAY AND INTO FRIDAY, BUT ANOTHER STORM SYSTEM IS EXPECTED TO BRING MORE RAIN AND COOLER TEMPERATURES FRIDAY AFTERNOON INTO SATURDAY. SNOW LEVELS WITH THIS FASTER MOVING SYSTEM SHOULD REMAIN ABOVE 4500 FEET, SO WIDESPREAD SNOW LIKE WE ARE SEEING TODAY IS NOT EXPECTED. THE GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE TIMING OF THE FRONTAL PASSAGE, SO HAVE BUMPED UP PRECIPITATION CHANCES TO LIKELY FOR SATURDAY. ANOTHER SYSTEM IS EXPECTED EARLY NEXT WEEK, MOST LIKELY MONDAY NIGHT OR TUESDAY. THERE IS STILL A GOOD DEAL OF UNCERTAINTY REGARDING THE DETAILS, BUT MODELS ARE IN REMARKABLY GOOD AGREEMENT GIVEN THE TIME RANGE. GUIDANCE ALSO SUGGESTS THAT THIS SYSTEM WILL INVOLVE A COLDER AIR MASS, SO THERE IS THE POTENTIAL FOR ANOTHER SNOW EVENT, MUCH LIKE TODAY. STAY TUNED FOR UPDATES THROUGH THE WEEK. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 8 PM PDT THIS EVENING FOR ORZ027-028-617-621-623. WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON ABOVE 3000 FEET FOR FOR ORZ621. CA...WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ081-281. WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON ABOVE 3000 FEET FOR FOR CAZ080-280. WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ082-282. WINTER STORM WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ083-284. PACIFIC COASTAL WATERS...NONE. $$
AREA FORECAST DISCUSSION
NWS PORTLAND
900 AM PDT TUE APR 7 2015 .SYNOPSIS...A LOW PRES OFF THE S OREGON COAST TUE MORNING WILL MOVE S AND THEN E TODAY AND TONIGHT...MOVING INLAND ACROSS NORTHERN CA AND NV. ANOTHER WEAK TROUGH OF LOW PRES ALOFT WILL MOVE S OVER EASTERN WA AND OREGON WED AS A SURFACE RIDGE OF HIGH PRES STRENGTHENS ALONG THE COAST. THE HIGH WILL MOVE INLAND WED NIGHT AND THU. THE NEXT PACIFIC FRONTAL SYSTEM IS EXPECTED TO MOVE DOWN FROM THE GULF OF AK AND PUSH INLAND FRI AND FRI NIGHT. && .UPDATE...A LOW OFFSHORE CONTINUES TO BRING BANDS OF RAIN ACROSS THE AREA TODAY. THE FIRST BAND NOW OVER THE NORTHERN OREGON ZONES THIS MORNING CONTINUES TO PERSIST SO HAVE ADJUSTED FORECAST TO MATCH. MODELS SHOW THIS BAND WEAKENING THIS AFTERNOON AS ANOTHER DEFORMATION BAND NOW SEEN IN ITS EARLY STAGES ON THE SE QUADRANT OF THE LOW OFF THE NORTHERN CALIFORNIA COAST.MONDAYS MODELS HAD THE MAIN FOCUS OF THE PCPN WITH THIS BAND OVER EASTERN LINN AND LANE COUNTY FOR THIS AFTERNOON AND TONIGHT.THIS MORNING SOME MODELS LIKE THE HRRR ARE FOCUSING THE HEAVIER PCPN FURTHER NORTH FOR THIS EVENING SO SOME ADJUSTMENTS MAY BE NEEDED TO THE FORECAST. IF THE HRRR IS CORRECT THE HEAVIER SNOWFALL IN THE CASCADES MAY VERY WELL BE IN THE NORTH CASCADES VS. THE CENTRAL CASCADES. MODELS GENERALLY AGREE IN WEAKENING THE BAND LATE TONIGHT AND WED. PREVIOUS DISCUSSION... SHORT TERM...MAIN UPPER LOW SEEN IN WATER VAPOR PICTURES EARLY TUE MORNING WAS NEAR 42N 128W...STILL MOVING SLOWLY S. A WEAKENING DEFORMATION BAND OF LIGHT RAIN REMAINED ACROSS SW WA AND THE EXTREME NW CORNER OF OREGON...AND IS EXPECTED TO CONTINUE TO FIZZLE OUT THIS MORNING. WHILE THE FOCUS FOR PRECIPITATION WITH THIS LOW REMAINS TO THE S...SOME SHOWERS EXPECTED TO CONTINUE TO ROTATE AROUND THE N PART OF THE LOW TODAY AND TONIGHT AS THE LOW TURNS E AND MOVES INLAND ACROSS NORTHERN CA. MODELS GENERALLY SHOWING AN ENHANCED AREA OF PRECIPITATION OVER THE SE PART OF THE FORECAST AREA LATE TODAY AND INTO TONIGHT...GENERALLY OVER THE OREGON PART OF THE CASCADES S OF MT JEFFERSON. GFS AND NAM SUGGEST THE ENHANCED PRECIPITATION IS RELATED TO AN AREA OF DEFORMATION ON THE N SIDE OF THE LOW AS IT MOVES BY TO THE S. GIVEN THE GOOD AGREEMENT IN MODELS SHOWING THIS QPF FIELD...AND WITH SNOW LEVELS STILL AT OR A LITTLE BELOW PASS LEVELS...WILL GO AHEAD WITH A WINTER WEATHER ADVISORY FOR SNOW THERE ABOVE 4500 FT LATE THIS AFTERNOON AND CONTINUING PAST MIDNIGHT. MOST OF THE PRECIPITATION ASSOCIATED WITH THE UPPER LOW IS EXPECTED TO END WED MORNING AS IT MOVES OFF TO THE E...BUT ANOTHER TROUGH COMING DOWN FROM THE N WILL BRING A LESSER THREAT FOR SHOWERS GOING WED AFTERNOON AND EVENING. THIS UPPER TROUGH HAS AN INLAND TRACK COMING DOWN FROM BC WHICH IS NORMALLY DRY...BUT A LOW LEVEL ONSHORE FLOW WILL KEEP ENOUGH MOISTURE AVAILABLE TO GENERATE AN UNSTABLE LAYER IN THE LOW TO MID LEVELS WED AFTERNOON. A LOOK AT MODEL SOUNDINGS AT 00Z THU INDICATES UNSTABLE LAYER MAY BE MARGINALLY DEEP ENOUGH TO SUPPORT A SLIGHT CHANCE FOR THUNDER OVER THE CASCADES WED AFTERNOON...SO WILL MAINTAIN THE SLIGHT CHANCE THERE BUT PULL IT FROM AREAS FURTHER W. WILL CONTINUE WITH A SLIGHT CHANCE FOR SHOWERS AGAIN THU AFTERNOON OVER THE CASCADES AS THE WEAK TROUGH REMAINS OVER THE AREA IN AT LEAST SOME MODELS. OTHERWISE RISING HEIGHTS SUGGESTS A WARMER DAY FOR THU. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. THURSDAY NIGHT THROUGH SUNDAY...WHAT RESIDUAL SHOWERS THAT FORM THURSDAY AFTERNOON WILL CLEAR THURSDAY NIGHT. THE MODELS ARE COMING INTO BETTER AGREEMENT WITH THE NEXT FRONT BEGINNING TO MOVE ONSHORE AND SPREAD RAIN ONSHORE ON FRIDAY...AND MOVING THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON FRIDAY NIGHT. SNOW LEVELS ARE FORECAST TO RISE ABOVE THE CASCADE PASSES FRIDAY BEFORE FALLING BELOW THE PASSES FRIDAY NIGHT AND STAYING WELL BELOW THE PASSES OVER THE WEEKEND AS BRISK ONSHORE FLOW SPREADS COOL SHOWERY AIR ONSHORE AND LIKELY GIVES THE CASCADES ANOTHER GOOD DOSE OF SNOW. THE ECMWF MODEL HAS THE BRUNT OF THE ONSHORE FLOW FARTHER NORTH THAN THE GFS AND NAM12 MODELS...SO THAT IS THE MAIN UNCERTAINTY ABOUT CASCADE SNOW FOR THIS WEEKEND AT THIS POINT. ANOTHER PACIFIC FRONT IS POSSIBLE EARLY NEXT WEEK...CONTINUING THE CURRENT EARLY SPRING PATTERN. TOLLESON && .AVIATION...A WEAK LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL PUSH ASHORE NEAR THE CALIFORNIA/OREGON STATE LINE THIS EVENING. THIS SHOULD RESULT IN MAINLY VFR CONDITIONS WITH OCCASIONAL LIGHT RAIN SHOWERS MVFR CONDITIONS ALONG THE COAST...PARTICULARLY AT KONP. IN ADDITION...WEAK NORTHERLY FLOW IN THE SOUTHERN WILLAMETTE VALLEY WILL PRODUCE IFR AND MVFR CONDITIONS AT KEUG THIS MORNING. A BAND OF HEAVIER PRECIPITATION IS EXPECTED TO FORM OVER THE CENTRAL OREGON CASCADES AND MAY ALSO MOVE CLOSE ENOUGH TO KSLE AND KEUG TO BRING MVFR CONDITIONS TO THESE TERMINALS AFTER 00Z WEDNESDAY. THERE IS SOME CHANCE THIS BAND OF PRECIP WILL MOVE NORTH AND AFFECT THE PDX AREA TERMINALS LATE THIS AFTERNOON AND EVENING. KPDX AND APPROACHES...EXPECT PRIMARILY VFR CONDITIONS THROUGH 12Z WEDNESDAY. MODELS ARE STARTING TO SHOW A BAND OF SHOWERS NEAR THE TERMINAL LATE THIS AFTERNOON AND EVENING WHICH COULD PRODUCE MVFR CONDITIONS FOR A NUMBER OF HOURS. BOWEN/NEUMAN && .MARINE...A WEAK LOW PRESSURE SYSTEM WILL SLOWLY DRIFT SOUTHWARD THIS MORNING AND PUSH ASHORE NEAR THE CALIFORNIA/OREGON BORDER LATE TODAY. THIS WILL RESULT IN WEAKENING WINDS THROUGH THE MORNING HOURS AND WINDS AT BUOY 29 ARE ALREADY DECREASING. BUILDING HIGH PRESSURE OVER THE WATERS SHOULD THEN BRING MORE TRANQUIL WIND AND SEAS THROUGH THURSDAY NIGHT. A QUICK MOVING FRONT WILL LIKELY BRING A BURST OF 25 TO 35 KT SOUTHERLY WIND GUSTS ON FRIDAY. A LARGE FETCH OF GUSTY 25 KT WESTERLY WINDS IN ITS WAKE WILL AID IN THE ARRIVAL OF A 10 TO 15 FT SWELL OVER THE WEEKEND. HIGH PRESSURE LOOKS TO RETURN LATE IN THE WEEKEND BEFORE ANOTHER SIMILAR STORM SYSTEM ARRIVES EARLY NEXT WEEK...AND POSSIBLY PUSHES SEAS WELL ABOVE 10 FT ONCE AGAIN. BOWEN/NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 3 AM PDT WEDNESDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1138 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. REGIONAL RADAR LOOP AT 03Z SHOWS A CLUSTER OF SHRA/TSRA APPROACHING SW PA IN ADVANCE OF WEAK SHORTWAVE LIFTING THRU THE OHIO VALLEY. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY POPS BTWN 05Z-08Z ACROSS SOUTHERN SOMERSET/BEDFORD COUNTIES. THIS AREA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. ELSEWHERE...OUTSIDE OF SOME PATCHY DRIZZLE...THE BALANCE OF THE NIGHT LOOKS DRY ACROSS MOST OF CENTRAL PA. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE ALLEGHENY FRONT WILL LIKELY GET INTO THE 50S. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/MARTIN NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...MARTIN AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. REGIONAL RADAR LOOP AT 03Z SHOWS A CLUSTER OF SHRA/TSRA APPROACHING SW PA IN ADVANCE OF WEAK SHORTWAVE LIFTING THRU THE OHIO VALLEY. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY POPS BTWN 05Z-08Z ACROSS SOUTHERN SOMERSET/BEDFORD COUNTIES. THIS AREA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. ELSEWHERE...OUTSIDE OF SOME PATCHY DRIZZLE...THE BALANCE OF THE NIGHT LOOKS DRY ACROSS MOST OF CENTRAL PA. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE ALLEGHENY FRONT WILL LIKELY GET INTO THE 50S. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/MARTIN NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...MARTIN AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
728 PM EDT WED APR 8 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH THURSDAY. A STORM SYSTEM WILL BRING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER CONDITIONS NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE APPALACHIANS. MAIN FEATURE OF NOTE THIS EVENING IS WELL DEFINED SHORTWAVE/MCV TRACKING ACROSS SOUTHERN PA. REGIONAL RADAR LOOP AT 21Z SHOWS WEAKENING CONVECTION MOVING INTO THE ALLEGHENY MTNS AS IT ENCOUNTERS COOL/STABLE AIR MASS. HOWEVER...LG SCALE FORCING AHEAD OF THIS FEATURE WILL LIKELY SUPPORT A PERIOD OF SHOWERS ACROSS MOST OF CENTRAL PA AS IT MOVES THRU THIS EVENING. RADAR TRENDS AND LATEST HRRR OUTPUT SUGGEST THE SHOWERS WILL BE EXITING THE EASTERN COUNTIES BY ARND 03Z. IN THE WAKE OF THIS EVENING/S SHORTWAVE...EXPECT DRY CONDS FOR MOST OF THE REGION LATE TONIGHT. THE EXCEPTION WILL BE ACROSS THE SOUTHWEST COUNTIES...WHERE SHOWERS MAY ARRIVE TOWARD DAWN IN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS RANGING FROM THE U30S OVR THE HIGH TERRAIN NORTH AND EAST OF KIPT...TO THE M40S ALONG THE SPINE OF THE ALLEGHENY MTNS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... ANOTHER COOL/CLOUDY DAY ON TAP FOR THURSDAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...TO CHC ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...ELEVATED TSRA A DEFINITE POSSIBILITY ACROSS THE NW COUNTIES LATE IN THE DAY. HIGHS WILL BE WITHIN A DEGREE OR TWO OF TODAY IN MOST AREAS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/MARTIN NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...FITZGERALD/LA CORTE LONG TERM...MARTIN AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
535 PM EDT TUE APR 7 2015 .SYNOPSIS... A FRONTAL BOUNDARY DRAPED OVER CENTRAL PA WILL DRIFT SLOWLY TO THE SOUTH TONIGHT THROUGH THURSDAY. MOIST AIR STREAMING NE ABOVE A SHALLOW AND COOL AIRMASS DROPPING SOUTHWARD BEHIND THE FRONT WILL BRING PERIODS OF A SHOWERS OVER THE NEXT SEVERAL DAYS. A BIT OF LIGHT FREEZING RAIN IS EVEN POSSIBLE AT SOME HIGHER ELEVATIONS THROUGHOUT CENTRAL AND NORTHEASTERN PA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY...AS STRENGTHENING HIGH PRESSURE BUILDING ACROSS QUEBEC PUMPS COLD AIR SOUTH INTO THE REGION. A DEEP STORM SYSTEM LIFTING ACROSS THE GREAT LAKES ON FRIDAY WILL BRING WARMER CONDITIONS BACK INTO THE AREA...WITH A CHANCE OF THUNDERSTORMS. A COLD FRONT WILL BE FOLLOWED BY COLDER TEMPERATURES FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... BULK OF THE RAIN SHOWERS PUSHING EAST OF THE SUSQ RIVER AS OF 21Z IN ADVANCE OF WEAK MID LVL SHORTWAVE OVR THE CENTRAL PART OF THE STATE. RADAR TRENDS AND LATEST HRRR SUGGEST THE STEADIEST RAIN WILL EXIT THE EASTERN COUNTIES BY ARND 00Z. AT THE SFC...BACK DOOR COLD FRONT IS PUSHING THRU SOUTHERN PA AT 21Z AND SHOULD PRESS SOUTH OF THE MASON DIXON LINE THIS EVENING. A MOIST...EASTERLY FLOW NORTH OF THIS BOUNDARY WILL LIKELY PRODUCE OCNL DRIZZLE ACROSS CENTRAL PA LATER TONIGHT. IN ADDITION...UPSTREAM SHORTWAVE OVR THE LOWER GRT LKS WILL LIFT THRU LATER TONIGHT...BRINGING SCT SHRA. WILL CONTINUE TO CARRY LIKELY POPS EVERYWHERE TONIGHT...ALTHOUGH AMOUNTS ARE NOT EXPECTED TO BE SUBSTANTIAL. GENERALLY A TRACE TO A FEW HUNDRETHS IN MOST AREAS...UP TO A TENTH IN SOME LOCATIONS. 1038 MB SFC HIGH SPREADING EASTWARD FROM ONTARIO TO QUEBEC WILL INDUCE CAD ACROSS EASTERN PA OVERNIGHT WITH COOLER LLVL TEMPS BLEEDING SOUTHWARD INTO WEDNESDAY MORNING. READINGS BY DAWN SHOULD RANGE FROM THE U30S OVR THE HIGH TERRAIN NORTH AND EAST OF KIPT...TO THE M40S OVR THE SOUTHERN COUNTIES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... COOL AND DANK CONDITIONS WILL BE THE NORM ON WEDNESDAY IN CAD REGIME WITH PLENTY OF LLVL MOISTURE AND OVERRUNNING ZONAL FLOW ALOFT PROMOTING LIGHT SHOWERS ESPECIALLY IN THE AFTERNOON. HIGHS WILL RANGE THROUGH THE 40S FOR MOST...BUT AREAS ALONG THE ALLEGHENY FRONT MAY NUDGE INTO THE WARM SECTOR WITH WESTERN WARREN AND WESTERN SOMERSET COUNTIES REACHING INTO THE 50S AND PERHAPS NEAR 60 ACROSS SOUTHWEST SOMERSET COUNTY. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... DID NOT CHANGE POPS OR WEATHER FOR WED NIGHT...GIVEN SLIGHT CHANCE FOR A LITTLE FREEZING DRIZZLE OR RAIN ACROSS THE NE. LOWS NEAR HUDSON AND JAMES BAY AREA WERE ZERO TO 20 BELOW THIS MORNING. THAT IS COLD FOR EARLY APRIL. DETAILS BELOW... GIVEN THE FACT THAT WE/LL HAVE A 1040 MB SFC HIGH BECOMING PARKED ACROSS SRN QUEBEC /WHERE CURRENT TEMPS ARE IN THE SINGLE DIGITS TO TEENS/ AND 1000 MB AGEOSTROPIC FLOW INCREASING FROM THE NORTH-NORTHEAST /AND STAYING THERE FOR A 24-36 HOURS PERIOD/...WENT SEVERAL DEG F BELOW MODEL TEMPS FOR WED MAXES AND WED NIGHT MINS. EVEN MENTIONED A SLIGHT CHC FOR LIGHT FZRA ACROSS PARTS OF THE NCENT MTNS AND WRN POCONOS LATE WED NIGHT AND EARLY THURSDAY. THIS LLVL COLD AIR DAMMING LIKELY TO LINGER INTO THURSDAY AFT. SOME NEW DETAIL BELOW... WHILE TEMPS MAY NOT WARM REAL GOOD THU...AND I LEFT THEM CLOSE TO WHAT WE HAD...WILL CONTINUE TO MONITOR. VERY TIGHT TEMPERATURE GRADIENT AT 850 MB LATE WED EVENING ACROSS CENTRAL NY...MINUS 4 TO PLUS 10 IN ABOUT 80 TO 100 MILE BAND. ANYWAY...WARMER AIR WILL WORK INTO THE AREA LATE THU INTO FRIDAY...AS LOW LEVEL WIND FIELDS INCREASE. WARMEST TEMPERATURES MIGHT END UP BEING ACROSS WARREN COUNTY. DID NOT UP TEMPS MUCH FOR FRIDAY...MODELS MOVE COLD FRONT ACROSS THE AREA RATHER FAST. SOME CHANCE OF A STRONG THUNDERSTORM ACROSS THE WEST LATER FRIDAY. THIS BASED ON TIMING AND THE THERMAL RIDGE OVER THE BEST MOISTURE. HAVE TO WATCH FOR SEVERE...BUT DYNAMICS LIKELY TO LIFT NE AWAY FROM THE AREA. ALSO TIMING NOT THE BEST. WHILE WE WILL SEE SOME SHOWERS EACH DAY THIS WEEK...NOT SEEING ANY LARGE AMTS. THUS NOT SEEING ANY WIDESPREAD HYDRO CONCERNS AT THIS POINT. ENJOY THE MILDER TEMPERATURES. RATHER STRONG SMALL UPPER LEVEL TROUGH FOR LATE FRIDAY INTO SAT. TOOK OUT SHOWERS AFTER EARLY FRIDAY EVENING. MAIN THING WAS TO LOWER TEMPS FOR FRIDAY NIGHT INTO SAT...GIVEN AIRMASS TO THE NORTH AND COLD ADVECTION. WEEKEND SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID PUT SOME SHOWERS IN THE FAR WEST LATE MONDAY AND ACROSS THE AREA ON TUE. MODELS SHOW ANOTHER COLD FRONT MOVING IN. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... BANDS OF SCATTERED LIGHT SHOWERS CONTINUE TO STREAM EASTWARD OVER CENTRAL PA THIS MORNING. AS A FRONT CONTINUES TO PUSH EVER SO SLOWLY SOUTHWARD...MVFR RESTRICTIONS WILL CONTINUE TO SAG SOUTHWARD THROUGH THE DAY. IFR CONDITIONS WILL AFFECT THE NORTHERN MTNS AS FRONT PUSHES INTO HIGH DEWPOINT AIR. ONCE THESE IFR/MVFR RESTRICTIONS ARRIVE IN A LOCATION...THEY WILL THEN PERSIST FOR AN EXTENDED PERIOD AS UNSETTLED WEATHER IMPACTS THE REGION THROUGH THE WEEK. MARGINAL CAPE MAY BRING ISOLATED THUNDER TO THE SOUTHERN TIER OF CENTRAL PA THROUGH THIS EVENING. WINDS WILL REMAIN LIGHT INTO WED. OUTLOOK... WED...WIDESPREAD MVFR/IFR IN SHRA/PERIODS OF RA. THU...REDUCTIONS LIKELY IN SCT SHRA. FRI...REDUCTIONS LIKELY IN SHRA...ESPECIALLY DURING THE AFT. CHC OF THUNDER AFT. SAT-SUN...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR/FITZGERALD SHORT TERM...DEVOIR LONG TERM...LAMBERT/MARTIN AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1028 PM EDT WED APR 8 2015 .SYNOPSIS... M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION THIS WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AS OF 1000 PM...THE LATEST SPC MESOANALYSIS PAGE STILL SHOWS 1000-2000 J/KG OF MUCAPE. A COUPLE OF ISOLD TSTMS HAVE POPPED UP IN THE MIDLANDS...AND THE LAST COUPLE OF HRRR RUNS DO SHOW A FEW MORE CELLS DEVELOPING OVER THE NEXT FEW HOURS SOUTH OF I-85. SO WILL ADD A SLGT CHC BACK IN ACRS THE SOUTHEASTERN ZONES. CANNOT RULE OUT A SEVERE PULSE STORM GIVEN THE CAPE AND 25-30 KTS OF EFFECTIVE SHEAR. OTHERWISE...THE REST OF THE FCST LOOKS ON TRACK. AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN. TEMPS/SKY/WINDS ARE ON TRACK. AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY PRECIP...IF THE LATEST TRENDS HOLD. AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA. SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH LARGE HAIL AND DAMAGING WINDS. UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN 1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES CLOSER TO ANY SHORTWAVE ACTIVITY. TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT... WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL IN FAIRLY GOOD AGREEMENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT. WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND 850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION... ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE. ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... AT KCLT...CONDITIONS CONTINUE TO BE TRANQUIL ACRS THE AREA HEADING INTO THIS EVENING. BASED ON THE LATEST GUIDANCE AND RADAR/SAT TRENDS...EXPECT CONVECTION TO REMAIN WELL NORTH AND EAST OF THE TERMINAL OVERNIGHT. WINDS WILL BE CALM OR LIGHT SOUTH WITH GENERALLY THIN CIRRUS OVERHEAD. SOME OF THE GUIDANCE STILL INDICATES IFR CIGS AND SPOTTY VSBY/FOG RESTRICTIONS. HOWEVER...GIVEN NO RAIN FELL TODAY...AND PERIODS OF HIGH CLOUDS...WILL REMOVE MENTION OF LOW CLOUDS WITH THE 00Z TAF. ON THURSDAY...THE ATMOSPHERE ACTUALLY LOOKS LESS UNSTABLE...WITH LACK OF A TRIGGER FOR CONVECTION ONCE AGAIN. HOWEVER...BY LATE AFTN GUIDANCE DOES SHOW SCATTERED CONVECTION DEVELOPING ACRS WESTERN NC. SO WILL ADD A PROB30 FOR TSRA STARTING AROUND 19Z. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN. ELSEWHERE...SIMILAR TO KCLT DISCUSSION ABOVE. GIVEN LACK OF RAIN TODAY AND WARM OVERNIGHT TEMPS UNDER PERIODS OF CIRRUS CIGS...EXPECT ONLY PATCHY HZ/BR OVERNIGHT...PRIMARILY AT KAVL AND KHKY. OTHERWISE...EXPECT VFR CONDITIONS. ON THURSDAY...GUIDANCE ONCE AGAIN DEVELOPS CONVECTION DURING THE PEAKING HEATING AFTN HOURS. HOWEVER...THE ATMOSPHERE LOOKS LESS UNSTABLE WITH STILL A LACK OF TRIGGER LIKE TODAY. WILL ADD PROB30 FOR TSRA FOR NOW. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN. OUTLOOK...A COLD FRONT WILL PUSH THROUGH LATE FRIDAY...BRING WITH IT THE POTENTIAL FOR AT LEAST SCATTERED CONVECTION. WITH AFTERNOON CONVECTION WILL FOLLOW POTENTIAL FOR RESTRICTIONS IN THE MORNING. MUCH IMPROVED CONDITIONS FOR THE WEEKEND AFTER THE FRONT CLEARS THE AREA. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-00Z KCLT HIGH 100% MED 69% HIGH 98% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% MED 74% HIGH 96% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...ARK/TDP SHORT TERM...PM LONG TERM...RWH AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
746 PM EDT WED APR 8 2015 .SYNOPSIS... M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION THIS WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN. TEMPS/SKY/WINDS ARE ON TRACK. AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY PRECIP...IF THE LATEST TRENDS HOLD. AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA. SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH LARGE HAIL AND DAMAGING WINDS. UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN 1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES CLOSER TO ANY SHORTWAVE ACTIVITY. TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT... WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL IN FAIRLY GOOD AGREEMENT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT. WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND 850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION... ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE. ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AT KCLT...CONDITIONS CONTINUE TO BE TRANQUIL ACRS THE AREA HEADING INTO THIS EVENING. BASED ON THE LATEST GUIDANCE AND RADAR/SAT TRENDS...EXPECT CONVECTION TO REMAIN WELL NORTH AND EAST OF THE TERMINAL OVERNIGHT. WINDS WILL BE CALM OR LIGHT SOUTH WITH GENERALLY THIN CIRRUS OVERHEAD. SOME OF THE GUIDANCE STILL INDICATES IFR CIGS AND SPOTTY VSBY/FOG RESTRICTIONS. HOWEVER...GIVEN NO RAIN FELL TODAY...AND PERIODS OF HIGH CLOUDS...WILL REMOVE MENTION OF LOW CLOUDS WITH THE 00Z TAF. ON THURSDAY...THE ATMOSPHERE ACTUALLY LOOKS LESS UNSTABLE...WITH LACK OF A TRIGGER FOR CONVECTION ONCE AGAIN. HOWEVER...BY LATE AFTN GUIDANCE DOES SHOW SCATTERED CONVECTION DEVELOPING ACRS WESTERN NC. SO WILL ADD A PROB30 FOR TSRA STARTING AROUND 19Z. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN. ELSEWHERE...SIMILAR TO KCLT DISCUSSION ABOVE. GIVEN LACK OF RAIN TODAY AND WARM OVERNIGHT TEMPS UNDER PERIODS OF CIRRUS CIGS...EXPECT ONLY PATCHY HZ/BR OVERNIGHT...PRIMARILY AT KAVL AND KHKY. OTHERWISE...EXPECT VFR CONDITIONS. ON THURSDAY...GUIDANCE ONCE AGAIN DEVELOPS CONVECTION DURING THE PEAKING HEATING AFTN HOURS. HOWEVER...THE ATMOSPHERE LOOKS LESS UNSTABLE WITH STILL A LACK OF TRIGGER LIKE TODAY. WILL ADD PROB30 FOR TSRA FOR NOW. WINDS WILL BE A BIT STRONGER AND GUSTY OUT OF THE SW THURSDAY AFTN. OUTLOOK...A COLD FRONT WILL PUSH THROUGH LATE FRIDAY...BRING WITH IT THE POTENTIAL FOR AT LEAST SCATTERED CONVECTION. WITH AFTERNOON CONVECTION WILL FOLLOW POTENTIAL FOR RESTRICTIONS IN THE MORNING. MUCH IMPROVED CONDITIONS FOR THE WEEKEND AFTER THE FRONT CLEARS THE AREA. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-18Z KCLT HIGH 100% HIGH 83% HIGH 83% HIGH 100% KGSP HIGH 100% HIGH 100% MED 66% HIGH 100% KAVL HIGH 100% HIGH 100% MED 66% HIGH 100% KHKY HIGH 100% HIGH 100% MED 66% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% MED 66% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...ARK/TDP SHORT TERM...PM LONG TERM...RWH AVIATION...ARK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
644 PM CDT WED APR 8 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 346 PM CDT WED APR 8 2015 PERSISTENT LOW CLOUD EVENT EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT INTO TOMORROW AS LOW LEVEL EASTERLY FLOW REINFORCES STRATUS ACROSS THE AREA. BAD OF 850 HPA THETA-E ADVECTION IS EXPECTED TO LIFT NORTH THROUGH THE LATE AFTERNOON INTO THE EVENING HOURS. STILL SOME QUESTION AS TO HOW CONVECTIVE ANY ACTIVITY MAY GET AS VERY STEEP LAPSE RATES EXIST FROM 700-300 MB ACROSS THE SOUTHEASTERN CWA. RAP SOUNDINGS SHOW SMALL WARM NOSE HOLDING...BUT NOT SURE AM READY TO BUY INTO THAT ENTIRELY SO HAVE HELD ON TO THE MENTION OF THUNDER THROUGH THE LATE AFTERNOON. WITH STEEP LAPSE RATES AND COLD ATMOSPHERE...CERTAINLY A GOOD CASE FOR HAIL IF A STORM CAN DEVELOP FROM THE ELEVATED WARM AIR AND MOISTURE ADVECTION. ISENTROPIC LIFT CONTINUES THROUGH THE OVERNIGHT THOUGH CONTINUE TO HAVE OFF AND ON SATURATION ISSUES ALOFT. THEREFORE...AM EXPECTING LIGHT RAIN OR DRIZZLE THROUGH THE EVENING HOURS...INCREASING AFTER MIDNIGHT AS THE DEFORMATION BAND APPROACHES FROM THE WEST. AS THE SURFACE COLD FRONT/INVERTED TROUGH MOVES THROUGH THE AREA...FLOW TURNS MORE NORTHERLY WITH WARM NOSE ALOFT COOLING. THERE IS THE POTENTIAL FOR A FEW FLAKES TO MIX IN WITH THE RAIN TOMORROW DURING THE DAY...ESPECIALLY IN THE HIGHER ELEVATIONS...BUT WITH THE WARM LAYER NEAR THE SURFACE REMAINING STEADY THROUGH THE DAY...AM NOT EXPECTING SNOW TO ACCUMULATE. HAVE LOWERED FORECAST HIGHS ACROSS THE EAST WITH PRECIPITATION LINGERING THROUGH MUCH OF THE DAY...WHILE SKIES SHOULD BEGIN TO CLEAR OUT IN CENTRAL SOUTH DAKOTA THROUGH THE AFTERNOON HOURS LEADING TO A LATE DAY RECOVERY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 346 PM CDT WED APR 8 2015 COULD SEE A LITTLE PRECIP LINGERING IN OUR FAR EAST INTO THURSDAY EVENING...BUT OTHERWISE EXPECT GENERALLY DRY CONDITIONS TO PREVAIL THROUGH THE MIDDLE RANGE OF THE FORECAST AS MID LEVEL RIDGE MOVES ACROSS THE NORTHERN PLAINS. AS THE RIDGE AXIS SHIFTS EAST INTO IOWA AND MINNESOTA LATE SATURDAY/SATURDAY NIGHT...RETURN FLOW OF MOISTURE AND WEAK ELEVATED INSTABILITY COULD LEAD TO SOME ISOLATED SHOWERS OR THUNDERSTORMS. THIS CHANCE WILL LINGER IN THE EAST INTO SUNDAY AS THE MID LEVEL TROUGH AND ASSOCIATED SURFACE FRONT PUSH THROUGH THE AREA. TEMPERATURES WILL BE ON A WARMING TREND AGAIN...WITH MID 50S TO MID 60S EXPECTED FOR HIGHS ON FRIDAY...AND UPPER 60S TO MID 70S BY SATURDAY. THE MILD AIR WILL STICK AROUND THROUGH AT LEAST THE MIDDLE OF NEXT WEEK...THOUGH WITH THE DIVERGENCE IN MODEL SOLUTIONS BY TUESDAY AND WEDNESDAY...THERE IS SOME UNCERTAINTY ON JUST HOW WARM TEMPERATURES WILL BE. OPTED TO STICK FAIRLY CLOSE TO BROAD MODEL BLEND FOR NOW... WHICH KEEPS HIGHS IN THE MID 60S TO MID 70S AND LOWS IN THE 40S TO LOWER 50S. AS FAR AS PRECIP CHANCES...IT CURRENTLY LOOKS LIKE SUNDAY NIGHT TO MONDAY SHOULD BE FAIRLY DRY AS THE NORTHERN STREAM TROUGH SHIFTS TO THE EAST...AND WEAK RIDGING DEVELOPS AHEAD OF A SOUTHERN STREAM WAVE THAT IS FORECAST TO SWING INTO THE PLAINS FROM THE SOUTHERN ROCKIES MONDAY NIGHT. THIS WILL BRING A BIT MORE UNSETTLED WEATHER TO THE AREA MONDAY NIGHT/TUESDAY. GREATER UNCERTAINTY REGARDING THE CHANCE FOR PRECIP TUESDAY NIGHT/WEDNESDAY DUE TO AFOREMENTIONED DIVERGENCE IN MODEL SOLUTIONS. WITH LOW CONFIDENCE IN ANY ONE SOLUTION...WILL HANG ON TO SOME LOW 20-30 RANGE POPS FOR NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 639 PM CDT WED APR 8 2015 LOOKING AT IFR CONDITIONS THROUGH THE NIGHT WITH SOME PATCHY LIFR NOT OUT OF THE QUESTION. THIS WILL OCCUR MAINLY ON THE CEILING SIDE OF THINGS WHILE THE VISIBILITY WILL GENERALLY BE IN THE MVFR TO OCCASIONAL IFR CATEGORY. FROM ABOUT 7Z THROUGH 12Z PARTS OF NORTHEAST NEBRASKA...NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA WILL SEE A WINDOW OF ABOUT TWO HOURS WITH MODERATE TO BRIEFLY HEAVY RAINFALL ALONG WITH THE THREAT FOR A FEW LIGHTNING STRIKES. GRADUAL IMPROVEMENT FROM CENTRAL SOUTH DAKOTA TOWARDS INTERSTATE 29 IS EXPECTED AFTER ABOUT 19Z THURSDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...JH AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1048 PM CDT WED APR 8 2015 RETRANSMITTED AFD .AVIATION... A WEAKENING LINE OF THUNDERSTORMS TO THE WEST AND NORTHWEST OF THE DFW METROPLEX IS NOT EXPECTED TO IMPACT THE AIRPORTS. HOWEVER...THERE IS STILL A POTENTIAL FOR SCATTERED THUNDERSTORM DEVELOPMENT LATER TONIGHT AND WILL KEEP THE VCTS MENTION IN THE METROPLEX FROM 09-12Z FOR NOW. THE LIGHT RAIN HAS DISSIPATED AROUND THE WACO AREA BUT THE ATMOSPHERE IS CONDUCIVE FOR STRONG AND GUSTY WINDS TO REACH THE SURFACE UNDERNEATH THE DISSIPATING RAIN. KACT HAS ALREADY RECORDED WIND GUSTS TO 32 KTS AND THE WINDS IN THE METROPLEX HAVE INCREASED IN THE LAST HOUR OR TWO. WITH THE THUNDERSTORMS TO THE WEST WEAKENING AS THEY REACH THE I-35 CORRIDOR...ADDITIONAL WIND GUSTS MAY OCCUR EVEN IF THUNDERSTORMS DO NOT OCCUR. EXPECT SUSTAINED WINDS OF 15-20 KTS WITH GUSTS OF 25-30 KTS THROUGH THE NIGHT...AND OCCASIONAL GUSTS NEAR 35 KTS. JLDUNN .../PREVIOUS AVIATION DISCUSSION/... /ISSUED 652 PM CDT WED APR 8 2015/ /00Z TAFS/ CONCERNS...MVFR CIGS RETURN OVERNIGHT. CHANCE FOR THUNDERSTORMS OVERNIGHT OR EARLY THURSDAY MORNING. CHANCE FOR THUNDERSTORMS LATE THURSDAY AFTERNOON WITH A COLD FRONT ARRIVING IN THE EVENING HOURS. SOME SHOWERS AND LIGHT RAIN CONTINUE ACROSS THE REGION THIS EVENING BUT ARE GENERALLY DIMINISHING OR MOVING EAST OF THE TAF SITES. WILL KEEP A VCSH MENTION AT KACT FOR A FEW HOURS AND THEN EXPECT AT LEAST A FEW HOURS OF DRY WEATHER BEFORE ADDITIONAL SHOWERS AND THUNDERSTORMS ARRIVE OVERNIGHT OR EARLY THURSDAY MORNING. MOSAIC RADAR ACROSS THE STATE SHOWS NUMEROUS SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED IN WEST TEXAS IN ASSOCIATION WITH A SHORTWAVE. THE TAF CURRENTLY BRINGS VCTS INTO THE DFW METROPLEX FROM 09-12Z BUT THIS TIMING MAY HAVE TO BE BUMPED UP. BASED ON THE TRACK OF THE SHORTWAVE TO THE NORTHEAST...LEFT ANY CONVECTION MENTION OUT OF KACT BUT MAY HAVE TO INCLUDE A MENTION OF THUNDERSTORMS WITH THE NEXT AMENDMENT. THESE STORMS SHOULD QUICKLY MOVE THROUGH THE AIRPORTS ONLY AFFECTING OPERATIONS FOR THREE HOURS OR LESS. THEN...THE NEXT ROUND OF THUNDERSTORMS IS EXPECTED AFTER 09/21Z AS A COLD FRONT MOVES INTO THE AREA. THE STORMS THURSDAY AFTERNOON AND EVENING COULD BE STRONG OR SEVERE PRODUCING LARGE HAIL AND DAMAGING WINDS. VFR CONDITIONS ARE EXPECTED THIS EVENING WITH MVFR STRATUS SURGING NORTH OVERNIGHT. THE STRATUS WILL ARRIVE AT KACT AROUND 06Z AND THEN THE METROPLEX AROUND 09Z WITH BASES BETWEEN 1-2 KFT. SIMILAR TO TODAY...CIGS ARE EXPECTED TO LIFT ABOVE 2 KFT BY MIDDAY AND THEN TO BETWEEN 3-4 KFT BY MID-LATE AFTERNOON. SOUTH WINDS BETWEEN 10-15 KTS WILL PREVAIL THROUGH THE PERIOD AND THEN SWITCH TO THE NORTH AS A COLD FRONT ARRIVES THURSDAY EVENING. THE FRONT IS EXPECTED TO ARRIVE IN THE METROPLEX BETWEEN 10/01-03Z AND KACT BY 10/06Z. JLDUNN && .UPDATE... A BIT OF A WEIRD UPDATE TO INCREASE WIND GUSTS FOR TONIGHT. 00Z FWD SOUNDING SHOWED A PROFILE THAT CAN BE VERY FAVORABLE FOR HEATBURSTS. HEATBURSTS ARE A TYPE OF MICROBURST...BUT USUALLY OCCUR AT NIGHT AND ARE ACCOMPANIED BY AN INCREASE IN TEMPERATURE... AN INCREASE IN WIND...FALLING PRESSURE AND FALLING HUMIDITY. WE DONT REALLY EXPECT ANY WILD THERMOMETER FLUCTUATIONS TONIGHT...BUT THESE HEATBURSTS LOOK LIKE THEY WILL BE ABLE TO PRODUCE GUSTY WINDS IN EXCESS OF 40 MPH. WITH A STRONG LOW LEVEL JET OF 40-50 MPH IN PLACE...ESSENTIALLY THE HEATBURSTS HELP TO TRANSPORT THESE WINDS DOWN TO THE SURFACE. ALREADY A FEW SITES HAVE GUSTED OVER 40 MPH IN THE LAST 2 HOURS WITH SEVERAL OTHERS ABOVE 35 MPH. HEATBURSTS ARE MOST LIKELY TO OCCUR WHERE RADAR SHOWS SOME LIGHT REFLECTIVITY ALOFT...AS THE FIRST STEP TO GET A HEATBURST IS TO START A DOWNDRAFT IN THE MID LEVELS. WITH ALL OF THE WEAK RADAR ECHOES AND THE POTENTIAL FOR SOME DISSIPATING ELEVATED THUNDERSTORMS MOVING IN FROM THE WEST LATER TONIGHT...IT IS LIKELY SEVERAL LOCATIONS MAY EXPERIENCE PERIODS OF GUSTY WINDS OVERNIGHT. TR.92 && .PREV UPDATE... UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN WEST TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY WILL WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH. OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE. MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON. THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD. TR.92 && .PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/ A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS. CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT. THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW BENEATH A JUICY LLJ. AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE LINE IMPACTS SOUTHERN AND EASTERN ZONES. THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR ACTIVITIES. THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF RICH GULF MOISTURE. 25 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40 WACO, TX 68 82 59 74 61 / 30 50 40 30 50 PARIS, TX 65 79 54 73 55 / 40 60 50 20 30 DENTON, TX 68 82 54 73 56 / 50 40 30 20 40 MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40 DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40 TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40 CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40 TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50 MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
942 PM CDT Wed Apr 8 2015 .DISCUSSION... Forecast has been updated to remove Severe Thunderstorm Watch 38 from all but Haskell County. Haskell County will be removed after this line of thunderstorms move through. Expecting wind gusts in the 40 mph range, but will allow the storms to move through before cancelling the watch. Have also lowered PoPs across the area somewhat as the southern end of the line of thunderstorms continues to decay as it moves east. 20 && .PREV DISCUSSION... /ISSUED 736 PM CDT Wed Apr 8 2015/ DISCUSSION... Have updated forecast products for Severe Thunderstorm Watch 38 in effect for areas generally west of a Haskell/Abilene/Ballinger/ San Angelo line through 1 AM. Gusts over 60 mph and hail up to the size of quarters are possible with these storms. The line should start moving into Sterling/Irion Counties between 8 and 830 PM, and into the Nolan/Fisher County area between 830 and 9 PM. 20 PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/ AVIATION... /00Z TAFS/ Skies have cleared, except for a blanket of mid and upper level clouds across most of west central Texas. A weakly organized broken band of thunderstorms is moving toward the west central Texas area this evening. Have these storms moving across our TAF sites roughly between 01Z(8PM) and 06Z(1AM). These storms have brought gusts of over 40 knots to areas to our west. This is likely due to very dry low layers of the atmosphere, and fast movement of the storms themselves. Will carry a mention of gusty winds to 35 knots in TEMPO groups at area sites to account for the possibility of gusty winds. Based on most recent trends (gusts to 35-40 knots), do not expect these to bring severe strength wind gusts of 50 knots or great at this time, but this cannot be ruled out. For the rest of the overnight hours, models have become much less pessimistic with respect to low clouds after 03Z(10PM) tonight, so will go with higher, but still MVFR (2500 feet) CIGS at most sites tonight beginning around 06Z(1AM). Winds will remain south to southeasterly and gusty through most of the overnight. Winds will shift to the west tomorrow between 12Z(7AM) and 15Z(10AM). 20 PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/ SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 40 5 10 20 40 San Angelo 66 87 57 73 61 / 30 10 10 40 40 Junction 66 85 62 75 62 / 30 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
936 PM CDT WED APR 8 2015 .UPDATE... /RAISED POPS...THUNDER CHANCES WRN THIRD/ FAST PACED CONVECTIVE CLUSTER ARRIVING FROM WEST TX IS A SOUTHWARD EXTENT OF A BROKEN LINE OF CONVECTION THAT EXTENDS NORTH INTO NW TX. THE SOUTHERN ENHANCEMENTS ARE LIKELY THE PRODUCT OF FAVORABLE JET DYNAMICS AND STEEPENING MID LEVEL LAPSE RATES. MOST OF THE HI-RES RUNS SHOWN THE ACTIVITY WEAKENING BEFORE REACHING THE I-35 CORRIDOR...BUT DO SHOW SOME AREAS OF LIGHT QPF FROM LIGHT SHOWERS. WILL EXTEND A MENTION OF SPRINKLES INTO SOUTHEAST COUNTIES AND BEEF UP POPS OVER MAINLY VAL VERDE COUNTY AND TO A SMALLER EXTENT THE RIO GRANDE PLAINS. OTHERWISE...THE FORECAST REMAINS ON TRACK. && .PREV DISCUSSION... /ISSUED 703 PM CDT WED APR 8 2015/ AVIATION... THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON THURSDAY. PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A FREDERICKSBURG TO LA GRANGE LINE. FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB. WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS MOSTLY DRY. FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/ LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY AND POCKETS OF HEAVY RAIN OVER THE WEEKEND. FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND SOUTHERN ZONES. FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS. FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 78 69 85 66 77 / 30 20 30 30 50 AUSTIN BERGSTROM INTL AIRPORT 78 68 83 66 77 / 30 20 30 30 50 NEW BRAUNFELS MUNI AIRPORT 81 68 85 67 79 / 20 20 20 10 50 BURNET MUNI AIRPORT 76 66 84 63 74 / 40 30 40 30 50 DEL RIO INTL AIRPORT 78 68 89 69 83 / 50 50 - 20 50 GEORGETOWN MUNI AIRPORT 77 68 84 64 75 / 30 30 40 40 50 HONDO MUNI AIRPORT 82 68 86 68 80 / 30 30 10 10 50 SAN MARCOS MUNI AIRPORT 79 69 84 66 78 / 20 20 20 20 50 LA GRANGE - FAYETTE REGIONAL 82 70 84 69 80 / 20 10 20 20 50 SAN ANTONIO INTL AIRPORT 81 69 85 69 79 / 30 20 10 10 50 STINSON MUNI AIRPORT 82 69 86 69 80 / 20 20 10 10 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...18 PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
927 PM CDT WED APR 8 2015 .UPDATE... A BIT OF A WEIRD UPDATE TO INCREASE WIND GUSTS FOR TONIGHT. 00Z FWD SOUNDING SHOWED A PROFILE THAT CAN BE VERY FAVORABLE FOR HEATBURSTS. HEATBURSTS ARE A TYPE OF MICROBURST...BUT USUALLY OCCUR AT NIGHT AND ARE ACCOMPANIED BY AN INCREASE IN TEMPERATURE... AN INCREASE IN WIND...FALLING PRESSURE AND FALLING HUMIDITY. WE DONT REALLY EXPECT ANY WILD THERMOMETER FLUCTUATIONS TONIGHT...BUT THESE HEATBURSTS LOOK LIKE THEY WILL BE ABLE TO PRODUCE GUSTY WINDS IN EXCESS OF 40 MPH. WITH A STRONG LOW LEVEL JET OF 40-50 MPH IN PLACE...ESSENTIALLY THE HEATBURSTS HELP TO TRANSPORT THESE WINDS DOWN TO THE SURFACE. ALREADY A FEW SITES HAVE GUSTED OVER 40 MPH IN THE LAST 2 HOURS WITH SEVERAL OTHERS ABOVE 35 MPH. HEATBURSTS ARE MOST LIKELY TO OCCUR WHERE RADAR SHOWS SOME LIGHT REFLECTIVITY ALOFT...AS THE FIRST STEP TO GET A HEATBURST IS TO START A DOWNDRAFT IN THE MID LEVELS. WITH ALL OF THE WEAK RADAR ECHOES AND THE POTENTIAL FOR SOME DISSIPATING ELEVATED THUNDERSTORMS MOVING IN FROM THE WEST LATER TONIGHT...IT IS LIKELY SEVERAL LOCATIONS MAY EXPERIENCE PERIODS OF GUSTY WINDS OVERNIGHT. TR.92 && .PREV UPDATE... UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN WEST TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY WILL WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH. OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE. MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON. THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD. TR.92 && .PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/ A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS. CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT. THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW BENEATH A JUICY LLJ. AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE LINE IMPACTS SOUTHERN AND EASTERN ZONES. THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR ACTIVITIES. THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF RICH GULF MOISTURE. 25 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40 WACO, TX 68 82 59 74 61 / 30 50 40 30 50 PARIS, TX 65 79 54 73 55 / 40 60 50 20 30 DENTON, TX 68 82 54 73 56 / 50 40 30 20 40 MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40 DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40 TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40 CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40 TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50 MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
742 PM CDT WED APR 8 2015 .UPDATE... UPDATED THE FORECAST TO REDUCE EVENING POPS TO JUST A SLIGHT CHANCE OF SHOWERS. AROUND MIDNIGHT THE CONVECTIVE ACTIVITY IN WEST TEXAS WILL BE ARRIVING INTO THE WESTERN ZONES. THIS ACTIVITY WILL WEAKEN IN INTENSITY BY THIS TIME AND WILL BECOME ELEVATED ALOFT...THUS NOT HAVING ACCESS TO THE MOST UNSTABLE AIR NEAR THE GROUND. HOWEVER RUC MODEL SOUNDINGS DO INDICATE OVER 1000 J/KG WITH LITTLE CINH WITH PARCELS LIFTED FROM NEAR 750MB. THIS OBVIOUSLY IS ENOUGH INSTABILITY FOR THUNDERSTORMS...JUST NOT ENOUGH FOR A SEVERE WEATHER THREAT. POPS WERE INCREASED ACROSS THE NW ZONES A BIT...WHERE SCATTERED CONVECTION OVERNIGHT IS MOST LIKELY...DUE TO THE TRACK OF THE SHORTWAVE TROUGH. OTHERWISE TOMORROW AFTERNOON AND EVENING LOOK BUSY WEATHER-WISE. MODEL DATA AND PATTERN RECOGNITION ALL POINT TOWARD SCATTERED TO NUMEROUS THUNDERSTORMS DEVELOPING ALONG THE FRONT AS IT REACHES A SHERMAN TO FORT WORTH TO STEPHENVILLE LINE LATE IN THE AFTERNOON. THE CAP SHOULD BECOME VERY WEAK TO NON-EXISTENT TOMORROW. GIVEN THE HIGH AMOUNTS OF INSTABILITY...SEVERE WEATHER LOOKS LIKELY IN OUR CWA AND IT SHOULD BE THE FIRST TIME OUR CWA WILL BE INCLUDED IN A SEVERE WEATHER WATCH BOX THIS YEAR. LIMITED LOW LEVEL WIND SHEAR WILL HOPEFULLY KEEP THIS EVENT FROM BECOMING TOO DANGEROUS...BUT IF PROGGED INSTABILITY VALUES OF 3000+ J/KG DO COME TRUE...THERE IS PLENTY OF CAPE BELOW 0-3KM TO AID IN NEAR SURFACE PARCEL ACCELERATION FOR TORNADOGENESIS. IT IS TOO EARLY TO DIVE INTO THE MESOSCALE ANALYSIS OF WHAT/WHEN AND WHERE EXACTLY...AS THESE CLUES WILL BECOME MORE APPARENT TOMORROW WITH THE AID OF HI-RES SHORT-TERM GUIDANCE AND REAL TIME DATA. SO OBVIOUSLY WE WILL NEED TO WATCH THIS EVENT UNFOLD VERY CLOSELY DUE TO THE POTENTIAL FOR SIGNIFICANT IMPACTS. FOR NOW HAVE UPDATED THE HWO TO BEEF UP THE WORDING AND IMPACT FOR THE SEVERE WEATHER THREAT THURSDAY AFTERNOON AND EVENING...BUT INHERITED GRIDS AND PARAMETERS OF THE SENSIBLE WEATHER FORECAST ALL LOOK GOOD. TR.92 && .AVIATION... /ISSUED 652 PM CDT WED APR 8 2015/ /00Z TAFS/ CONCERNS...MVFR CIGS RETURN OVERNIGHT. CHANCE FOR THUNDERSTORMS OVERNIGHT OR EARLY THURSDAY MORNING. CHANCE FOR THUNDERSTORMS LATE THURSDAY AFTERNOON WITH A COLD FRONT ARRIVING IN THE EVENING HOURS. SOME SHOWERS AND LIGHT RAIN CONTINUE ACROSS THE REGION THIS EVENING BUT ARE GENERALLY DIMINISHING OR MOVING EAST OF THE TAF SITES. WILL KEEP A VCSH MENTION AT KACT FOR A FEW HOURS AND THEN EXPECT AT LEAST A FEW HOURS OF DRY WEATHER BEFORE ADDITIONAL SHOWERS AND THUNDERSTORMS ARRIVE OVERNIGHT OR EARLY THURSDAY MORNING. MOSAIC RADAR ACROSS THE STATE SHOWS NUMEROUS SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED IN WEST TEXAS IN ASSOCIATION WITH A SHORTWAVE. THE TAF CURRENTLY BRINGS VCTS INTO THE DFW METROPLEX FROM 09-12Z BUT THIS TIMING MAY HAVE TO BE BUMPED UP. BASED ON THE TRACK OF THE SHORTWAVE TO THE NORTHEAST...LEFT ANY CONVECTION MENTION OUT OF KACT BUT MAY HAVE TO INCLUDE A MENTION OF THUNDERSTORMS WITH THE NEXT AMENDMENT. THESE STORMS SHOULD QUICKLY MOVE THROUGH THE AIRPORTS ONLY AFFECTING OPERATIONS FOR THREE HOURS OR LESS. THEN...THE NEXT ROUND OF THUNDERSTORMS IS EXPECTED AFTER 09/21Z AS A COLD FRONT MOVES INTO THE AREA. THE STORMS THURSDAY AFTERNOON AND EVENING COULD BE STRONG OR SEVERE PRODUCING LARGE HAIL AND DAMAGING WINDS. VFR CONDITIONS ARE EXPECTED THIS EVENING WITH MVFR STRATUS SURGING NORTH OVERNIGHT. THE STRATUS WILL ARRIVE AT KACT AROUND 06Z AND THEN THE METROPLEX AROUND 09Z WITH BASES BETWEEN 1-2 KFT. SIMILAR TO TODAY...CIGS ARE EXPECTED TO LIFT ABOVE 2 KFT BY MIDDAY AND THEN TO BETWEEN 3-4 KFT BY MID-LATE AFTERNOON. SOUTH WINDS BETWEEN 10-15 KTS WILL PREVAIL THROUGH THE PERIOD AND THEN SWITCH TO THE NORTH AS A COLD FRONT ARRIVES THURSDAY EVENING. THE FRONT IS EXPECTED TO ARRIVE IN THE METROPLEX BETWEEN 10/01-03Z AND KACT BY 10/06Z. JLDUNN && .PREV DISCUSSION... /ISSUED 345 PM CDT WED APR 8 2015/ A PASSING DISTURBANCE IN THE MID-LEVELS HAS RESULTED IN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS TODAY. BASED OVER 2 MILES ABOVE THE SURFACE...THESE ELEVATED CELLS HAVE BEEN UNABLE TO TAP THE UNSTABLE BOUNDARY LAYER...THOUGH THE LAPSE RATES ALOFT HAVE BEEN MORE THAN SUFFICIENT FOR GENERATING LIGHTNING. THE PRECIPITATION HAS HELPED TO MOISTEN AND WEAKEN THE CAP...BUT THE WIDESPREAD CLOUD COVER AND ASSOCIATED RAINFALL HAS STUNTED TEMPERATURES...GENERALLY REDUCED THE CONDITIONAL INSTABILITY ACROSS THE REGION. ALTHOUGH IT WILL BE DIFFICULT FOR ANY INDIVIDUAL UPDRAFT TO DOMINATE WITHIN THIS CLUSTER OF PRECIPITATION...IF ANY ARE ABLE TO TAP THE BOUNDARY LAYER...THEY COULD CERTAINLY PRODUCE LARGE HAIL AND DAMAGING DOWNBURST WINDS. CLOUD-TO-GROUND LIGHTNING WILL REMAIN THE PRIMARY THREAT. THE MID-LEVEL FLOW REMAINS NEARLY PARALLEL TO THE WEST TEXAS DRYLINE...LIMITING BOTH ITS EASTWARD PROGRESS AND THE LOW-LEVEL CONVERGENCE IN ITS VICINITY. THE CROSS-BOUNDARY COMPONENT IS MORE PRONOUNCED IN THE NORTHEASTERN PANHANDLE OF TEXAS...AIDED BY AN APPROACHING CYCLONE IN THE ROCKIES...BUT THIS WILL BE OF LITTLE CONSEQUENCE FOR NORTH TEXAS. THE DRYLINE DIRECTLY WEST OF NORTH TEXAS MAY STILL SEE SOME DEVELOPMENT LATE THIS AFTERNOON...BUT EXTENSIVE CLOUD COVER ON THE HUMID SIDE OF THE BOUNDARY HAS REDUCED THE BUOYANCY OF THE PARCELS MOST LIKELY TO BE MECHANICALLY LIFTED. AS THE ONGOING ACTIVITY ACROSS NORTH AND CENTRAL TEXAS SHIFTS EAST AND WEAKENS THIS EVENING...THERE MAY BE A BREAK IN THE PRECIPITATION BEFORE ANY WEST TEXAS STORMS INVADE. WILL WATCH FOR ACTIVITY IN THE PERMIAN BASIN...AS ANY SUCH STORMS WILL HAVE A TENDENCY TO SURGE EASTWARD TONIGHT...WITH VEERING MID-LEVEL FLOW BENEATH A JUICY LLJ. AS THE CYCLONE SWINGS THROUGH CENTRAL PLAINS ON THURSDAY IT WILL FORCE A COLD FRONT INTO NORTH TEXAS. THE BOUNDARY WILL STEADILY MOVE THROUGH THE REGION THURSDAY AFTERNOON...EVENING...AND OVERNIGHT THURSDAY NIGHT. WHILE THIS MIGHT SUGGEST WIDESPREAD SHOWERS AND THUNDERSTORMS...A STUBBORN CAP MAY LIMIT INITIATION UNTIL WELL INTO THE AFTERNOON HOURS. PREFRONTAL MLCAPE VALUES WILL SOAR TO 2000-4000J/KG. THOUGH THE SHEAR VECTORS WILL BE NEARLY PARALLEL TO THE ADVANCING FRONT...THE FORCE OF ANY UPDRAFTS THAT FEED OFF THE BOUNDARY LAYER COULD RESULT IN A FEW SUPERCELLS BEFORE THE ACTIVITY CONGEALS INTO A LINE. A LARGE HAIL THREAT WILL STEADILY TRANSITION TO MORE OF A WIND THREAT IN THE EVENING AS THE LINE IMPACTS SOUTHERN AND EASTERN ZONES. THE FRONTAL BOUNDARY WILL LINGER IN CENTRAL AND EAST TEXAS ON FRIDAY...WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY OCCUR. THE FRONT WILL EVENTUALLY RETURN NORTH AS A WARM FRONT FRIDAY NIGHT INTO SATURDAY. WHILE NOT CONTINUOUS RAIN...GENERALLY WET WEATHER AND ASSOCIATED THUNDERSTORMS WILL LIKELY DISRUPT MANY OUTDOOR ACTIVITIES. THE UNSETTLED WET PATTERN WILL PREVAIL INTO NEXT WEEK WITH PERSISTENT SOUTHWESTERLY FLOW ALOFT AND A CONTINUOUS SUPPLY OF RICH GULF MOISTURE. 25 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 68 83 58 75 59 / 40 60 40 20 40 WACO, TX 68 82 59 74 61 / 30 50 40 30 50 PARIS, TX 65 79 54 73 55 / 40 60 50 20 30 DENTON, TX 68 82 54 73 56 / 50 40 30 20 40 MCKINNEY, TX 68 80 55 73 56 / 40 60 40 20 40 DALLAS, TX 68 82 58 74 60 / 40 60 40 20 40 TERRELL, TX 68 81 59 76 58 / 40 60 50 20 40 CORSICANA, TX 68 81 61 76 61 / 30 60 50 30 40 TEMPLE, TX 67 83 61 75 62 / 30 40 40 40 50 MINERAL WELLS, TX 66 86 55 74 57 / 50 30 20 20 50 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
736 PM CDT Wed Apr 8 2015 .DISCUSSION... Have updated forecast products for Severe Thunderstorm Watch 38 in effect for areas generally west of a Haskell/Abilene/Ballinger/ San Angelo line through 1 AM. Gusts over 60 mph and hail up to the size of quarters are possible with these storms. The line should start moving into Sterling/Irion Counties between 8 and 830 PM, and into the Nolan/Fisher County area between 830 and 9 PM. 20 && .PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/ AVIATION... /00Z TAFS/ Skies have cleared, except for a blanket of mid and upper level clouds across most of west central Texas. A weakly organized broken band of thunderstorms is moving toward the west central Texas area this evening. Have these storms moving across our TAF sites roughly between 01Z(8PM) and 06Z(1AM). These storms have brought gusts of over 40 knots to areas to our west. This is likely due to very dry low layers of the atmosphere, and fast movement of the storms themselves. Will carry a mention of gusty winds to 35 knots in TEMPO groups at area sites to account for the possibility of gusty winds. Based on most recent trends (gusts to 35-40 knots), do not expect these to bring severe strength wind gusts of 50 knots or great at this time, but this cannot be ruled out. For the rest of the overnight hours, models have become much less pessimistic with respect to low clouds after 03Z(10PM) tonight, so will go with higher, but still MVFR (2500 feet) CIGS at most sites tonight beginning around 06Z(1AM). Winds will remain south to southeasterly and gusty through most of the overnight. Winds will shift to the west tomorrow between 12Z(7AM) and 15Z(10AM). 20 PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/ SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 60 5 10 20 40 San Angelo 66 87 57 73 61 / 60 10 10 40 40 Junction 66 85 62 75 62 / 40 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
703 PM CDT WED APR 8 2015 .AVIATION... THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON THURSDAY. && .PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A FREDERICKSBURG TO LA GRANGE LINE. FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB. WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS MOSTLY DRY. FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/ LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY AND POCKETS OF HEAVY RAIN OVER THE WEEKEND. FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND SOUTHERN ZONES. FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS. FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50 AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50 NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50 BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50 DEL RIO INTL AIRPORT 68 89 69 83 67 / 30 - 20 50 50 GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50 HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50 SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50 LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50 SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50 STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...18 PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
624 PM CDT Wed Apr 8 2015 .AVIATION... /00Z TAFS/ Skies have cleared, except for a blanket of mid and upper level clouds across most of west central Texas. A weakly organized broken band of thunderstorms is moving toward the west central Texas area this evening. Have these storms moving across our TAF sites roughly between 01Z(8PM) and 06Z(1AM). These storms have brought gusts of over 40 knots to areas to our west. This is likely due to very dry low layers of the atmosphere, and fast movement of the storms themselves. Will carry a mention of gusty winds to 35 knots in TEMPO groups at area sites to account for the possibility of gusty winds. Based on most recent trends (gusts to 35-40 knots), do not expect these to bring severe strength wind gusts of 50 knots or great at this time, but this cannot be ruled out. For the rest of the overnight hours, models have become much less pessimistic with respect to low clouds after 03Z(10PM) tonight, so will go with higher, but still MVFR (2500 feet) CIGS at most sites tonight beginning around 06Z(1AM). Winds will remain south to southeasterly and gusty through most of the overnight. Winds will shift to the west tomorrow between 12Z(7AM) and 15Z(10AM). 20 && .PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/ SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 30 5 10 20 40 San Angelo 66 87 57 73 61 / 30 10 10 40 40 Junction 66 85 62 75 62 / 40 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1227 AM CDT TUE APR 7 2015 .AVIATION... MVFR CIGS HAVE DEVELOPED/SPREAD OVER MUCH OF SOUTH CENTRAL TEXAS...MOSTLY ALONG THE BALCONES ESCARPMENT AND IN THE HILL COUNTRY. EXPECT COVERAGE TO EXPAND ACROSS THE EASTERN COASTAL PLAINS AND WESTERN RIO GRANDE PLAINS OVERNIGHT...AS WELL AS A LOWERING TO IFR CIGS AT MOST LOCATIONS AFTER 10Z. IFR CIGS WITH 4-6SM BR VSBYS WILL PREVAIL THROUGH 16-17Z TUESDAY. AFTER THAT...THE FOG SHOULD DISSIPATE QUICKLY AND CIGS LIFT INTO MVFR AND BEGIN TO THIN...BUT WINDS WILL INCREASE TO 10G20KT OR SLIGHTLY HIGHER. LOOK FOR VFR SKIES AFTER 19Z...BUT MVFR CIGS WILL RETURN AROUND 02-04Z...THEN LOWER TO IFR CIGS FOR THE EXTENDED TAFS AT KAUS AND KSAT. && .PREV DISCUSSION... /ISSUED 934 PM CDT MON APR 6 2015/ UPDATE... LATE AFTERNOON/EARLY EVENING STORMS OUT OF THE NORTHEAST MEXICAN MOUNTAINS DISSIPATED AS THEY WERE MOVING EAST AND INTO A CAPPED REGION. MOST OF THE HIRES AND MEDIUM RANGE GUIDANCE ARE KEEPING THE AREA DRY OVERNIGHT WITH THE EXCEPTION OF LATEST HRRR AND RAPIP REFRESH WHICH BRING ISOLATED STORMS ACROSS THE RIO GRANDE PLAINS OVERNIGHT. AT THIS TIME...WILL GO WITH A DRY FORECAST AFTER MIDNIGHT AS SUGGESTED BY THE MAJORITY OF THE MODEL SOLUTIONS. ALSO...ADJUSTED TONIGHT`S TEMPS BASED ON CURRENT TRENDS AND MAV GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 83 68 84 69 84 / 10 10 10 10 10 AUSTIN BERGSTROM INTL AIRPORT 82 67 83 68 83 / 10 10 10 10 10 NEW BRAUNFELS MUNI AIRPORT 83 67 85 67 85 / 10 10 10 10 10 BURNET MUNI AIRPORT 82 67 84 66 83 / 10 10 10 10 10 DEL RIO INTL AIRPORT 84 69 87 69 88 / 10 20 10 10 10 GEORGETOWN MUNI AIRPORT 82 68 83 68 83 / 10 10 10 10 10 HONDO MUNI AIRPORT 82 68 84 68 86 / 10 10 10 - 10 SAN MARCOS MUNI AIRPORT 82 67 84 68 83 / 10 10 10 10 10 LA GRANGE - FAYETTE REGIONAL 82 69 84 70 83 / 10 10 10 10 10 SAN ANTONIO INTL AIRPORT 83 68 84 69 84 / 10 10 10 10 10 STINSON MUNI AIRPORT 83 68 84 68 85 / 10 10 10 10 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...26 SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1139 PM CDT MON APR 6 2015 .DISCUSSION... SEE 06Z AVIATION DISCUSSION. && .AVIATION... MODELS ARE AGAIN VERY AGGRESSIVE AND TOO QUICK WITH LOWERING CIGS INTO IFR/MVFR. THE HRRR/NAM AND RAP ARE TOO LOW WITH CIGS AND INITIALIZED POORLY. PREFER THE GFS FOR THE OVERNIGHT HOURS AND EVEN THE GFS EVENTUALLY LOWERS CIGS TO UNDER A 1000 FEET BY 12Z TUES. THERE SHOULD BE A BRIEF WINDOW OF LIFR/IFR CONDS AT ALL TAF SITES BETWEEN 11-15Z. THE GFS ALSO SCATTERS CLOUDS OUT BY 18Z WHICH MIGHT BE A TAD FAST. MVFR CIGS EXPECTED TO REDEVELOP LATE TUESDAY NIGHT. LIGHT TO MODERATE S-SE WINDS ARE EXPECTED THROUGH THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 1015 PM CDT MON APR 6 2015/ UPDATE... A FEW LIGHT RETURNS SHOWING UP EAST OF THE AREA THIS EVENING AHEAD OF A DISTURBANCE CROSSING TEXAS FROM MEXICO MAY PRODUCE A SPRINKLE OR TWO OVER THE FAR NORTHWESTERN FORECAST AREA... BUT EXPECT TONIGHT TO BE MOSTLY DRY ACROSS THE FORECAST AREA WITH A RATHER STOUT LAYER OF LOW TO MID LEVEL DRY AIR IN PLACE AND AIRCRAFT SOUNDINGS OUT OF HOUSTON SHOWING A CAPPING INVERSION BETWEEN 800-700 MB. FOR THIS UPDATE... ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURE AND DEW POINT GRIDS BASED ON LATEST OBSERVATIONS. HUFFMAN && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 82 68 82 70 / 10 10 10 10 20 HOUSTON (IAH) 68 84 69 83 70 / 10 10 10 10 10 GALVESTON (GLS) 69 77 71 78 71 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
855 PM EDT WED APR 8 2015 .SYNOPSIS... A BACK DOOR COOL FRONT OVER NORTHEAST VIRGINIA WILL CONTINUE TO EASE SOUTHWEST ACROSS THE PIEDMONT OVERNIGHT. THE BOUNDARY WILL THEN LIFT BACK TO THE NORTH THURSDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FROM THE WEST. THIS FRONT WILL PUSH THROUGH FROM THE WEST FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AS OF 855 PM EDT TUESDAY... WEDNESDAY AFTERNOON CONVECTION HAS MOVED SOUTHEAST OUT OF THE FORECAST AREA. A WEAK HIGH PRESSURE CENTER WILL PROVIDE US WITH A SHORT BREAK IN THE ROUNDS OF CONVECTION THIS EVENING. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED IN OHIO AND KENTUCKY. THIS CONVECTION WILL CONTINUE TO MOVE EASTWARD AND ROTATE ACROSS OUR REGION TONIGHT INTO THURSDAY MORNING. THE TIMING OF THIS CONVECTION APPEARS A LITTLE FASTER THAN HIRES MODELS SUGGEST. THE BETTER INSTABILITY WILL OCCUR UNTIL AROUND 02Z...THEN THE INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH. LEANED THE POPS TOWARDS A HRRR AND RAP BLEND BECAUSE OF THE WARM ADVECTION SHOWERS NOTED ON WSR-88D IMAGES ACROSS WEST VIRGINIA. IN ADDITION TO THE SHOWERS AND THUNDERSTORMS...HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS EVENING INTO TONIGHT...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. RAINFALL FROM THIS EVENING AND TONIGHT STORMS WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND CREATE THE LOWER CLOUDS EXPECTED OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. INITIALLY SHAPED TEMPERATURES THIS EVENING INTO TONIGHT TOWARDS LAMP. THEN WITH THE RICH CLOUD COVER...OVERNIGHT TEMPERATURES WILL REMAIN MILD WITH READINGS FROM THE LOWER 50S IN THE MOUNTAINS TO THE UPPER 50S IN THE SOUTH. HIGHS ON THURSDAY WILL RANGE FROM THE UPPER 60S IN THE NORTH TO THE UPPER 70S IN THE SOUTH. AS OF 600 PM EDT TUESDAY... MADE SOME ADJUSTMENTS IN POPS AND WEATHER FOR THIS EVENING INTO TONIGHT...SHAPING TOWARDS WSR-88D RADAR TRENDS AND LATEST HRRR SOLUTION. ADJUSTED TEMPERATURES FOR THIS EVENING INTO TONIGHT. AS OF 415 PM EDT TUESDAY... KEEPING OUR EYES ON A SERIES OF DISTURBANCES STRETCHING FROM VIRGINIA TO THE MISSISSIPPI RIVER THIS AFTERNOON...ALL TRIGGERING THUNDERSTORM ACTIVITY AND ALL PROGGED TO RIDE A STATIONARY FRONT EASTWARD THROUGH THE EVENING AND OVERNIGHT. THE FIRST LINE OF THUNDERSTORMS IS WEAKENING AS IT ENCOUNTERS THE DOWNSLOPE FLOW IN THE VICINITY OF INTERSTATE 64. EXPECT LOCALLY GUSTY WINDS AND POCKETS OF HEAVY RAIN AS THE LINE CROSSES MOUNTAINS...BUT BELIEVE SEVERE THUNDERSTORM ACTIVITY WILL BE ISOLATED AT BEST...IF AT ALL. FURTHER WEST...THUNDERSTORM ACTIVITY DEVELOPING ACROSS CENTRAL KENTUCKY IS EXPECTED TO ENTER OUR MOUNTAIN EMPIRE COUNTIES AFTER SUNSET...AND CONVECTION DEVELOPING OVER SOUTHERN ILLINOIS IS EXPECTED TO APPROACH OUR WESTERN RIDGES BEFORE DAWN THURSDAY. INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH...SO BELIEVE THE THREAT FOR SEVERE STORMS THIS EVENING AND TONIGHT REMAINS REMOTE. IN ADDITION TO STORMS...HIGH PRESSURE CONTINUES TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS AFTERNOON...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. BELIEVE THAT RAINFALL ENTERING THE AREA THIS EVENING AND TONIGHT WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND HELP TO STRENGTHEN THE HIGH PRESSURE AS IT BUILDS IN...WHICH WILL MAKE FOR WIDESPREAD CLOUD COVER OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. CLOUDS WILL MAINTAIN MILD TEMPERATURES THROUGH THE NIGHT...HOLDING OVERNIGHT LOWS IN THE MID AND UPPER 50S. WILL STICK TO THE COOL SIDE OF GUIDANCE FOR HIGH TEMPERATURES ON THURSDAY...HOLDING HIGHS IN THE LOW AND MID 70S FOR MUCH OF THE AREA. BELIEVE THAT TEMPERATURES WILL REMAIN COOL THROUGH MID AFTERNOON DUE TO THE MORE WIDESPREAD NATURE OF THE CLOUD COVER...AND THEN SEE A LATE DAY UPWARD SPIKE IN TEMPERATURES AS CLOUDS BEGIN TO BREAK UP DURING MAX AFTERNOON HEATING. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 400 PM EDT WEDNESDAY... STRONG SHORT WAVE OVER THE UPPER MID WEST WILL MOVE EAST THURSDAY NIGHT AND FRIDAY. THURSDAY NIGHT THE SURFACE LOW MOVES NORTHEAST ACROSS THE GREAT LAKES...THEN ON FRIDAY TRACKS INTO SOUTHERN ONTARIO. ANY REMNANTS OF THE SURFACE WEDGE AND MORE STABLE AIR MASS IN THE NORTHEAST COUNTY WARNING AREA WILL BE GONE ON THURSDAY EVENING. TIMING HAS BEEN CONSISTENT IN THE MODELS BRINGING THE ASSOCIATED COLD FRONT THROUGH A BULK OF THE COUNTY WARNING AREA ON FRIDAY. MODELS WERE FORECASTING BEST INSTABILITY AHEAD OF THE FRONT IN THE PIEDMONT ALONG THE EASTERN EDGE OF THE FORECAST AREA ON FRIDAY AFTERNOON...WITH CAPES OF AS HIGH AS 2000 J/KG POSSIBLE. WILL MAINTAIN MENTION OF SEVERE WEATHER THREAT IN THE HAZARDOUS WEATHER OUTLOOK. 12Z MODELS WERE VERY SIMILAR WITH THE TIMING OF THE FRONT ON FRIDAY. WILL MAKE SLIGHT ADJUSTMENTS TO THE LOCATION BETWEEN 18Z/2PM FRIDAY AND 00Z SATURDAY/8PM FRIDAY WITH A HIGHER PROBABILITY OF RAIN. MORE CHALLENGING TO TELL HOW MUCH COVERAGE OF SHOWERS AND THUNDERSTORMS THERE WILL BE AHEAD OF THE FRONT THURSDAY NIGHT. HAVE ALSO REMOVED THE RAIN BEHIND THE FRONT FOR LATE FRIDAY NIGHT AND SATURDAY. WILL BE TRENDING TOWARD WARMER GUIDANCE AHEAD OF THE FRONT FOR LOWS ON THURSDAY NIGHT. WILL BE STARTING MILD ON FRIDAY BUT LIMITED HEATING DURING THE MORNING OVER THE MOUNTAINS WHICH WILL HOLD TEMPERATURES IN THE 60S. IN THE EAST WHERE THE FRONT COMES THROUGH LATER...TEMPERATURES WILL RISE WELL INTO THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 200 PM EDT WEDNESDAY... SECOND PIECE OF ENERGY COMES THROUGH THE NORTHEASTERN TROF ON SATURDAY SO THE 500 MB LONG WAVE TROF DOES NOT MOVE EAST OF THE FORECAST AREA UNTIL SUNDAY MORNING. THEN PATTERN RETURNS TO RIDGING IN THE EAST AND TROFING THE WEST FOR THE REST OF THE PERIOD. HEIGHTS AT 500 MB BECOME MORE AMPLIFIED BY MONDAY AND TUESDAY. WITH A DEEP CLOSED LOW IN THE WEST MONDAY THROUGH WEDNESDAY...FORECAST AREA WILL BE IN BROAD SOUTHWEST FLOW WITH A SERIES OF SHORT WAVES TRACKING OUT OF THE SOUTHERN PLAINS. AT THE SURFACE A SECONDARY FRONT CROSSES THE NORTHEAST SATURDAY NIGHT BUT LOOKS FAIRLY WEAK BY THE TIME IT REACHES THE CENTRAL APPALACHIANS. WPC CONSIDERED NORTH AMERICAN AND GFS ENSEMBLES AS REASONABLE FOR THE UPPER AND SURFACE TIMING AND LOCATION OF FEATURES FOR THIS TIME FRAME. HIGH PRESSURE BUILDS IN FOLLOWING THE FRONT AND WILL BE CENTERED OVER THE FORECAST AREA ON SUNDAY MORNING. THE HIGH WILL BE OFFSHORE BY MONDAY AFTERNOON. WARM...MOIST AIR WILL BE IN PLACE ON TUESDAY AND WEDNESDAY. APPEARS THERE WILL BE NO ORGANIZED LIFTING MECHANISM TO GENERATE PRECIPITATION BUT ANY DECENT SHORT WAVE SHOULD BE ABLE TO TRIGGER AT LEAST AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AFTER TEMPERATURES DROP BEHIND THE FRONT ON FRIDAY...850 MB VALUES REBOUND MONDAY THROUGH WEDNESDAY. MODELS HOLD RESIDUAL LOW LEVEL MOISTURE IN THE WESTERN UPSLOPE AREAS THROUGH SATURDAY MORNING. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... AS OF 735 PM EDT WEDNESDAY... AREAS OF SHOWERS AND THUNDERSTORMS EXITING SOUTHEAST PORTION OF THE FORECAST AREA THIS EVENING. RAPID UPDATE MODELS INDICATE THAT CONVECTION DEVELOPING IN THE UNSTABLE AIR ACROSS CENTRAL KENTUCKY WILL PUSH INTO THE REGION UNTIL AROUND 09/02Z TIMEFRAME. FINALLY...THE REMNANTS OF THUNDERSTORM ACTIVITY OVER THE MISSISSIPPI RIVER ARE EXPECTED TO APPROACH THE AREA SHORTLY BEFORE DAWN ON THURSDAY. RAINFALL ENTERING THE AREA THIS EVENING AND TONIGHT WILL MOISTEN AND HELP TO STRENGTHEN THE HIGH PRESSURE WEDGE AS IT CONTINUES TO OVERSPREAD OUR AREA FROM THE NORTHEAST. MEDIUM CONFIDENCE THAT IFR CEILINGS AND LOW VISIBILITIES WILL DEVELOP AROUND MIDNIGHT FOR KROA/KLYH/KDAN AS STRATUS DEVELOPS. WILL ALSO SEE LOW STRATUS DEVELOP FOR KBCB/KBLF/KLWB AFTER MIDNIGHT...HOWEVER TIMING IS MORE UNCERTAIN AS IT WILL TAKE LONGER FOR HIGH PRESSURE TO BUILD IN. HIGH PRESSURE IS EXPECTED TO MAINTAIN ITS HOLD ON THURSDAY...WITH LOW CEILINGS LINGERING ACROSS MUCH OF THE AREA INTO MID AFTERNOON. WITH BETTER INSTABILITY ALONG THE CONTINENTAL DIVIDE WHERE HIGH PRESSURE HAS LESS INFLUENCE...MAY SEE A FEW SHOWERS AND ISOLATED THUNDERSTORMS DEVELOP BY LATE AFTERNOON IN MAXIMUM HEATING. EXTENDED AVIATION DISCUSSION... PROLONGED PERIOD OF MVFR CONDITIONS LOOKS IN ORDER INTO FRIDAY WITH A COLD FRONTAL PASSAGE EXPECTED LATER FRIDAY. COLD FRONT EXPECTED TO CLEAR THE REGION FRIDAY NIGHT-SATURDAY MORNING WITH ANY SHOWERS SUBSIDING...THOUGH SOME UPSLOPE MVFR CEILINGS MAY LINGER INTO SATURDAY AT KBLF/KLWB. WIDESPREAD VFR THEN RETURNS SATURDAY NIGHT AND SUNDAY UNDER HIGH PRESSURE BEHIND THE FRONT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF/KK NEAR TERM...KK/NF SHORT TERM...AMS LONG TERM...AMS AVIATION...KK/NF/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT WED APR 8 2015 .SHORT TERM...(TONIGHT THRU THU NIGHT) ISSUED AT 235 PM CDT WED APR 8 2015 MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES/RAIN AMOUNTS TONIGHT INTO THU NIGHT...SEVERE THREAT IN/NEAR SOUTHWEST WI THU AFTERNOON...SNOW POTENTIAL THU NIGHT...TEMPERATURES. 18Z DATA ANALYSIS HAD A BROAD AREA OF LOW PRESSURE CENTERED OVER EASTERN CO WITH A WARM FRONT EASTWARD THRU MO/CENTRAL IL. COOL CAN HIGH PRESSURE/RIDGING EXTENDED ACROSS LK SUPERIOR TO ND/SOUTHERN SASKAT. MUCH OF THE UPPER MIDWEST CAUGHT IN THE COOL EASTERLY FLOW BETWEEN THE HIGH/WARM FRONT...WITH PLENTY OF LOW LEVEL MOISTURE/ CLOUDS STUCK UNDER A RATHER STRONG INVERSION NEAR 850MB HELPING HOLD DOWN TEMPS AGAIN TODAY. MOST EARLY AFTERNOON TEMPS ACROSS MN/WI/IA ONLY IN THE MID 30S TO MID 40S. CONVECTION SO FAR TODAY LIMITED TO THE SOUTH 1/2 OF IA WHERE SOME MOISTURE WAS BEING PUSHED NORTHWARD OVER THE WARM FRONTAL BOUNDARY. NO PROBLEMS NOTED WITH 08.12Z MODEL INITIALIZATIONS. MODELS IN GOOD AGREEMENT AS THE SHORTWAVE ENERGY OVER THE CENTRAL ROCKIES MOVES INTO THE CENTRAL PLAINS BY 12Z THEN LIFTS TOWARD THE FCST AREA BY 00Z FRI. GOOD CONSENSUS FOR THE WAVE TO QUICKLY MOVE ACROSS/EAST OF THE FCST AREA THU EVENING WITH SECONDARY NORTHERN STREAM ENERGY TO DROP INTO THE REGION BEHIND IT LATER THU NIGHT. TREND IS A BIT FASTER AND WEAKER/MORE OPEN WAVE WITH THE FEATURE AS IT APPROACHES/ PASSES THU/THU NIGHT. GIVEN THE RATHER TIGHT CONSENSUS...SHORT TERM FCST CONFIDENCE IS GOOD THIS CYCLE. FOR THE SHORT TERM...LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT AND 850- 700MB MOISTURE TRANSPORT/THETA-E CONVERGENCE QUICKLY INCREASE/ SPREAD NORTHEAST ACROSS THE FCST AREA LATE THIS AFTERNOON/EVENING. THIS WITH PW VALUES IN THE INFLOW AIRMASS OF 1 TO 1.25 INCHES. THIS WITH FALLING HGTS AHEAD OF THE SHORTWAVE TROUGH ADVANCING INTO THE CENTRAL PLAINS AND SOME ELEVATED MUCAPE OF 250-750 J/KG COMING NORTH WITH THE INFLOW AIRMASS. ALL INDICATIONS ARE SHRA/TSRA TO SPREAD RATHER QUICKLY NORTH/NORTHEAST ACROSS THE FCST AREA THIS EVENING AS THE LEAD ROUND OF STRONGER LOW LEVEL FORCING LIFTS ACROSS THE AREA. TRENDED THE EVENING PRECIP CHANCES TOWARD 80-100 PERCENT FROM SOUTHWEST TO NORTHEAST ACROSS THE FCST AREA THRU THE EVENING. SFC LOW MOVES INT SOUTHWEST IA/NORTHWEST MO BY 12Z THU WITH THE WARM FRONT AHEAD OF IT JUST SOUTH OF THE WI/IL BORDER. DEEP LAYERED FORCING/LIFT INCREASE AGAIN LATE TONIGHT AND FOR THU WITH APPROACH OF THE MID LEVEL SHORTWAVE/TROUGH...WITH A STRONG FN CONVERGENCE SIGNAL AND DEVELOPMENT/TRANSITION TO A DEFORMATION BAND OF PRECIP ACROSS THE AREA NORTH OF THE LOW/WARM FRONT FOR THU INTO THU NIGHT. CAPE POOL IS JUST SOUTH OF THE FCST AREA THU...WITH SOME OF THIS COMING NORTH INTO THE FCST AREA WITH THE INFLOW AIR. WILL TREND TOWARD HIGHEST TSRA CHANCES ACROSS THE CENTRAL/SOUTH PARTS OF THE FCST AREA CLOSE TO THE SFC LOW/CAPE POOL. WITH 07.12Z NAM HAVING DONE A VERY GOOD JOB WITH PRECIP/QPF TUE AFTERNOON/EVENING...WILL LEAN TOWARD ITS PRECIP FCST FOR TONIGHT/THU WITH RAIN AMOUNTS OF 0.75 TO 1.25 INCHES LIKELY ACROSS MUCH OF THE FCST AREA. SFC LOW TRACK WILL HAVE AN IMPACT ON THE SVR CHANCES ACROSS THE SOUTHEAST END OF THE FCST AREA THU AFTERNOON. LATEST MODEL CONSENSUS IS FURTHER SOUTH WITH THE SFC LOW TRACK...CROSSING THE GRANT CO/IL BORDER AREA AROUND MID AFTERNOON THU. THIS WOULD EFFECTIVELY KEEP THE WARM SECTOR AND MUCH OF ANY SVR STORM RISK OUT OF THE FCST AREA. WILL LEAVE THE SVR RISK FOR THE SOUTHEAST END OF THE FCST FOR THU AFTERNOON AS IS FOR NOW...SEE SWODY2 FOR MORE DETAILS. THE LAST MAIN PROBLEM IS POTENTIAL PRECIP TYPE THU NIGHT BEFORE THE DEFORMATION BAND WEAKENS/MOVES OUT OF THE FCST AREA. MODEL SOUNDINGS SHOWING STRONG COOLING THE LOWER LEVELS THU EVENING WITH PASSAGE OF THE 850-500MB TROUGH AXIS...ENOUGH SO FOR PRECIP TO MIX WITH/CHANGE TO SNOW BEFORE ENDING OVER THE NORTHWEST HALF OF THE FCST AREA. THIS BEFORE THE DEEPER MOISTURE/ICE IN THE CLOUD TOPS WOULD MOVE OUT. TOUGH CALL BUT HAVE TO ENTERTAIN THE POSSIBILITY OF SOME WET SNOW ACCUMULATIONS ON GRASSY AREAS ACROSS SOUTHEAST MN INTO NORTH-CENTRAL WI THRU THE MID/LATE EVENING HOURS OF THU NIGHT AND ADDED THIS TO THE FCST GRIDS. USED A BLEND OF THE GUIDANCE LOWS/HIGHS FOR TONIGHT THRU THU NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 235 PM CDT WED APR 8 2015 MAIN FCST CONCERNS FOR FRIDAY THRU SATURDAY NIGHT...LINGERING -SHRA UNDER THE COLD POOL/MID LEVEL TROUGH FRI...RETURNING MOISTURE SMALL SHRA/TSRA CHANCE LATE SAT NIGHT...TEMPERATURES THRU THE PERIOD. 08.12Z MODELS IN GOOD AGREEMENT FOR THE NORTHERN STREAM SHORTWAVE/ TOUGH AXIS TO SWING SOUTHEAST ACROSS THE REGION FRI. TREND IS A BIT STRONGER WITH THIS FEATURE. GOOD CONSENSUS FOR THIS TROUGH TO EXIT QUICKLY WITH A SHORTWAVE RIDGE AXIS ALREADY OVER THE REGION BY 18Z SAT. THIS FEATURE ALSO RATHER TRANSIENT...PUSHED QUICKLY EAST BY STRONGER SHORTWAVE ENERGY MOVING EAST ALONG THE US/CAN BORDER AND INTO THE NORTHERN PLAINS BY 12Z SUN. TREND IS FASTER WITH THE US/CAN BORDER SHORTWAVE AT 12Z SUN. OVERALL FCST CONFIDENCE IN THE FRI THRU SAT NIGHT PERIOD IS AVERAGE TO GOOD THIS CYCLE. THIS PERIOD STARTS WITH THE STRONGER SFC-700MB LOW/TROUGH EXITING QUICKLY EAST. NORTHERN STREAM SHORTWAVE DROPPING IN BRINGS A RATHER COLD 925-700MB AIRMASS ACROSS THE AREA FRI AFTERNOON. THIS WITH 700MB TEMPS IN THE -8C TO -14C RANGE. MODEL SOUNDINGS SHOWING STEEP LOW LEVEL LAPSE RATES/MIXING TO 700/650MB DURING THE FRI AFTERNOON HOURS WITH SOME MOISTURE IN THE 900-850MB LAYER. CHANCE OF -SHRA/- SHSN FRI MORNING/-SHRA FRI AFTERNOON OVER THE NORTHEAST 1/3 TO 1/2 OF THE FCST AREA LOOKS QUITE REASONABLE. THIS QUICKLY PASSES WITH RISING HGTS/HIGH PRESSURE RIDGING BUILDING ACROSS THE AREA FRI NIGHT/SAT. SFC RIDGE AXIS IS NEAR/OVER THE AREA FRI NIGHT. WITH CLEAR/CLEARING SKIES AND LIGHT WINDS...STRONGER RADIATIONAL COOLING AND A COLDER NIGHT EXPECTED. SOUTHERLY FLOW/LOW LEVEL WARM ADVECTION RETURN SAT WITH 925MB TEMPS IN THE +8C TO +12C RANGE BY 00Z SUN AND MODEL SOUNDINGS SHOWING MIXING TO NEAR 850MB. THESE 925MB TEMPS SUPPORTING HIGHS ON SAT IN THE UPPER 50S TO MID 60S. LOW LEVEL WARM ADVECTION CONTINUES SAT NIGHT WITH A SLOW INCREASE OF MOISTURE. SOUTH GRADIENT WINDS 8-15KTS SAT NIGHT KEEP THE BOUNDARY LAYER STIRRED/MIXED AND LOWS LOOKING TO BE SOME 12F TO 20F WARMER THAN THOSE OF FRI NIGHT/SAT MORNING. MAIN AXIS OF MOISTURE TRANSPORT/ INCREASE/WEAK INSTABILITY REMAINS WEST OF THE FCST AREA UNTIL LATER SAT NIGHT AND LIMITED SMALL -SHRA/-TSRA CHANCE ACROSS THE WEST END OF THE FCST AREA TO AFTER 06Z SUN. USED A BLEND OF THE MODEL/ ENSEMBLE HIGHS/LOWS FOR FRI THRU SAT NIGHT. FOR SUN THRU WED...DAYS 4 TO 7... MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES MUCH OF THE PERIOD...ABOVE NORMAL TEMPERATURES. 08.00Z/08.12Z MEDIUM RANGE MODELS IN GOOD AGREEMENT SUN FOR THE SHORTWAVE RIDGING FROM SAT TO BE FLATTENED/PUSHED EAST OF THE REGION BY A STRONGER SHORTWAVE MOVING EAST ALONG THE US/CAN BORDER. TREND IS TOWARD QUASI-ZONAL FLOW ACROSS THE NORTHERN CONUS SUN NIGHT/ MON...AS SHIFT FROM A MORE AMPLIFIED NOAM PATTERN IN THE MAR 06/07 MODEL RUNS. REASONABLE AGREEMENT AMONG MODELS THAT THIS ZONAL FLOW WILL NOT LAST LONG AS STRONG ENERGY/TROUGHING MOVES INTO THE WESTERN CONUS...WITH SOUTHWEST FLOW ALOFT OVER MUCH OF THE CENTRAL CONUS BY LATER TUE AND FOR WED AS DEEP TROUGHING/MID LEVEL LOW DEVELOPS OVER THE ROCKIES. REASONABLE AGREEMENT FOR A SHORTWAVE AHEAD OF THE MAIN ROCKIES TROUGH TO LIFT TOWARD/ACROSS THE UPPER MIDWEST TUE/TUE NIGHT. GIVEN THE REASONABLE CONSISTENCY BETWEEN THE MODELS OUT TO WED...DAY 4-7 FCST CONFIDENCE IS AVERAGE THIS CYCLE. LOWER LEVEL WARM/MOISTURE ADVECTION AHEAD OF THE NEXT TROUGH/FRONT CROSSING THE PLAINS CONTINUES INTO THE UPPER MIDWEST SUN. PW VALUES IN THE 1+ INCH RANGE AHEAD OF THE TROUGH/FRONT PROGGED TO PUSH ACROSS THE AREA LATER SUN/SUN EVENING...ALONG WITH MUCAPE IN THE 500- 1000 J/KG RANGE. MODEST 850-700MB FN CONVERGENCE WITH THE TROUGH/ FRONT ALONG WITH SOME LIFT/DIVERGENCE ALOFT AHEAD OF THE SHORTWAVE. CONSENSUS 25-40 PERCENT SHRA/TSRA CHANCES SUN/SUN NIGHT APPEAR WELL TRENDED. DRIER CAN/NORTHERN PLAINS HIGH PRESSURE TO BUILD IN BEHIND THE FRONT FOR MON...WITH MON/MON EVENING NOW TRENDING DRY. AS STRONGER TROUGHING DIGS INTO THE WESTERN CONUS MON NIGHT INTO WED... TROUGHING DEVELOPS IN THE CENTRAL PLAINS. STRENGTHENING SOUTHERLY FLOW AHEAD OF THIS LOW/TROUGH LOOKS TO QUICKLY RETURN MOISTURE NORTHWARD INTO THE UPPER MIDWEST BY LATER MON NIGHT AND THRU WED. PW VALUES IN THIS MOISTURE PLUME INTO THE AREA PROGGED INTO THE 1 TO 1.5 INCH RANGE BY LATER TUE. CAPE INCREASES INTO THE AREA AS WELL BY LATER TUE INTO WED. DEEPER LAYERED FORCING/LIFT ACROSS THE REGION AS WELL TUE/WED AHEAD OF THE SFC LOW/MID LEVEL TROUGHING ADVANCING SLOWLY EAST ACROSS/INTO THE CENTRAL CONUS. 30-40 PERCENT SHRA/TSRA CHANCES FOR TUE INTO WED LOOK GOOD AT THIS TIME. 850MB TEMPS PROGGED IN THE +7C TO +11C MUCH OF THE SUN-WED PERIOD WITH NAEFS SHOWING THIS TO BE 1 TO 1.5 STANDARDIZED ANOMALIES ABOVE NORMAL. WARMER MODEL/ENSEMBLE CONSENSUS HIGHS IN THE UPPER 50S/60S FOR SUN-WED APPEAR WELL TRENDED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1100 PM CDT WED APR 8 2015 CIGS... NOT A LOT OF CHANGE EXPECTED THROUGH THU NIGHT WITH MOST CIGS HOVERING AROUND OR BELOW 1 KFT. VARIOUS BOUTS OF SHRA/TS WILL KEEP CIGS LOWS...AS WILL POOLED MOISTURE UNDER A STRONG LOW LEVEL INVERSION. WINDS... WINDS WILL GO FROM EAST TO NORTH NORTH/NORTHWEST THU AFTERNOON AS AN AREA OF LOW PRESSURE SLIDES JUST SOUTH OF THE TAF SITES. INCREASING PRESSURE GRADIENT ON THE NORTHWEST SIDE OF THE LOW SHOULD RESULT IN AN INCREASE IN SUSTAINED WINDS - ALONG WITH THE POTENTIAL FOR HIGHER GUSTS - THU NIGHT. WX/VSBY... BANDS OF SHOWERS WILL SWEEP ACROSS THE REGION TONIGHT INTO THU NIGHT. THERE WILL LIKELY BE SEVERAL HOUR BREAKS BETWEEN THEM...BUT TRYING TO FERRET OUT EXACT TIMING IS PROBLEMATIC...SO WON/T GET THAT REFINED IN THE FORECAST. FOR THUNDER CHANCES...BUFKIT SOUNDINGS SHOW MEAGER INSTABILITY A LOFT...AND INTERESTINGLY MOST OF IT IS ABOVE THE SATURATED LAYER. THAT SAID...A FEW STORMS HAVE DEVELOPED AND APPROACHED KRST/KLSE. HAD TO UPDATE PREVIOUS TAFS TO INCLUDE MENTION FOR A FEW HOURS PAST 06Z. RUC GRADUALLY SINKS THE ELEVATED INSTABILITY SOUTHWARD OVERNIGHT. COULD BE ISOLATED THUNDER THU INTO THU NIGHT...BUT CONFIDENCE TOO LOW TO INCLUDE IN FORECAST AT THIS TIME. ALSO OF NOTE IN THE BUFKIT SOUNDINGS IS THE SOMEWHAT SHALLOW NATURE OF A LOT OF THE SATURATION. IN MANY WAYS ITS MORE SUGGESTIVE OF A HEAVY DRIZZLE RATHER THAN SHRA/RA TYPE EVENT. HAVE NOTED DRIZZLE ALREADY THIS EVENING...BEFORE SHOWERS MOVED IN. THU AFTERNOON SEEMS TO FAVOR DRIZZLE TOO. VSBYS WILL BE RESTRICTED IN THE HEAVIER PCPN...ESPECIALLY IF HEAVY DRIZZLE MANIFESTS. SOME FOG SHOULD HELP LOWER VSBYS OVERNIGHT INTO THU MORNING. && .HYDROLOGY...FOR TONIGHT/THURSDAY ISSUED AT 235 PM CDT WED APR 8 2015 PORTIONS OF THE FCST AREA RECEIVED 1 TO 2 INCHES OF RAIN LATE TUE/TUE EVENING. THESE RAINS PRODUCED MINOR WITHIN BANK RISES ON SOME OF THE RIVERS/STREAMS OF THE AREA. ANOTHER 0.5 TO 1.5 INCHES OF RAIN ARE EXPECTED TONIGHT INTO THU EVENING. IF THIS RAIN WERE TO FALL IN AN HOUR...MORE PRONOUNCED RISES MIGHT OCCUR ON SOME RIVERS AND STREAMS. HOWEVER...THIS RAIN IS EXPECTED TO FALL OVER A 24 TO 36 HR PERIOD. LITTLE MORE THAN ADDITIONAL MINOR WITHIN BANK RISES ARE ANTICIPATED TONIGHT THRU THU NIGHT...WITH THE DRIER SUB-SOILS ALLOWING MUCH OF THIS NEEDED MOISTURE TO SOAK INTO THE GROUND. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....RIECK HYDROLOGY....RRS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
915 PM CDT WED APR 8 2015 .UPDATE... FORCING WITH INCREASING LOW-LEVEL JET...AND ADDITIONAL FORCING FOR ASCENT PROVIDED BY 300-250 MB UPPER LEVEL DIVERGENCE...IS FINALLY ERODING SUBSIDENT LAYER ABOVE 10 K FT ON RAP SOUNDINGS WITH SCATTERED SHOWERS AND STORMS DEVELOPING IN REGION OF 925-850 MB FRONTOGENESIS FROM SPENCER IA TO JUST SOUTH OF STERLING IL AND MOVING NE AROUND 30 MPH. HAVE ADJUSTED POPS/WX TO FOLLOW RADAR TIMING THAT BRINGS SHOWERS AND SCATTERED ELEVATED STORMS TO SW LAFAYETTE COUNTY AROUND 1030 PM. EXPECT THE BAND OF SHOWERS AND STORMS TO CROSS CWA BETWEEN 1030 PM AND 5 AM. PATCHY DRIZZLE AND FOG WILL PRECEDE THE MAIN AREA OF SHOWERS. && .AVIATION/06Z TAFS/...COMING SOON && .MARINE... ALLOWED SMALL CRAFT ADVISORY TO EXPIRE AT 00Z AS WEB CAMS SHOWED WAVES HAD SUBSIDED BELOW CRITERIA. WEB CAMS ALSO SHOWING FOG IS GETTING MORE DENSE ALONG THE LAKESHORE WITH NEAR-SHORE OB SITES BETWEEN 1 1/2 MILES AND 1 3/4 MILES. EASILY 1 MILE OR LESS OVER THE WATER. WILL ISSUE A MARINE DENSE FOG ADVISORY UNTIL 14Z THURSDAY. && .PREV DISCUSSION... /ISSUED 346 PM CDT WED APR 8 2015/ SHORT TERM... TONIGHT AND THURSDAY...FORECAST CONFIDENCE IS MEDIUM. LOW CLOUDS WILL LINGER TONIGHT...WITH FOG LINGERING NEAR AND OVER THE LAKE. FOG HAS BEEN STUBBORN IN THE MILWAUKEE TO KENOSHA AREA...WITH 1/4 TO 1/2 MILE VISIBILITIES FOR MOST OF THE DAY. THESE VISIBILITIES SHOULD GRADUALLY CONTINUE TO IMPROVE INTO THE EARLY EVENING HOURS. WILL KEEP MENTION OF PATCHY DENSE FOG NEAR AND SOUTH OF MILWAUKEE TONIGHT...WITH PATCHY FOG ELSEWHERE. SYNOPTIC AND MESOSCALE MODELS CONTINUE TO SHOW ANOTHER ROUND OF SHOWERS WITH EMBEDDED ELEVATED CONVECTION PUSHING THROUGH THE AREA TONIGHT INTO THURSDAY MORNING. COULD SEE SMALL HAIL ONCE AGAIN WITH ANY OF THE STORMS...GIVEN COMBINATION OF ELEVATED CAPE AND EFFECTIVE LAYER SHEAR. BENEFICIAL RAINFALL INTO THURSDAY MORNING SHOULD BE IN THE 0.50 TO 0.60 INCH RANGE ACROSS THE AREA. MODELS STILL IN SOME DISAGREEMENT WITH SURFACE LOW TRACK FOR THURSDAY AFTERNOON AND EVENING...AND THIS WILL DETERMINE HOW UNSTABLE THE AREA GETS AND RESULTANT SEVERE WEATHER RISK. THE CONSENSUS TRACK SEEMS TO BE FROM EAST CENTRAL IOWA TO THE SHEBOYGAN AREA THURSDAY AFTERNOON AND EVENING. THIS WOULD BRING THE WARM FRONT AND WARM SECTOR INTO SOUTHEAST AND FAR SOUTH CENTRAL WISCONSIN. IF THIS OCCURS...AND ENOUGH SUNSHINE DEVELOPS...THERE WOULD LIKELY BE SEVERE STORM DEVELOPMENT GIVEN THE STRONG DEEP LAYER AND LOW LEVEL SHEAR VALUES. LARGE HAIL...DAMAGING WINDS AND TORNADOES WOULD ALL BE POSSIBLE...GIVEN THE PROXIMITY OF THE WARM FRONT AND SURFACE LOW. HOWEVER...IF TRACK ENDS UP FURTHER SOUTH...AS IT CAN AND HAS DONE IN THE PAST THIS TIME OF YEAR...WE WOULD END UP CLOUDY AND SEE ELEVATED CONVECTION AND A MUCH REDUCED SEVERE RISK. THIS WAS SUPPORTED SOMEWHAT BY CIPS ANALOGS...WHICH HAD BULK OF SEVERE REPORTS JUST SOUTH OF THE AREA. THERE WERE STILL SOME SEVERE HAIL/WIND REPORTS IN THE AREA. UPDATED DAY 2 OUTLOOK FROM SPC HAS THE FAR SOUTH CENTRAL AND SOUTHEAST COUNTIES IN SLIGHT TO ENHANCED RISK FOR SEVERE STORMS...WHICH SEEMS REASONABLE GIVEN THE CONSENSUS SURFACE LOW TRACK. THIS PERIOD WILL CERTAINLY NEED TO BE WATCHED CLOSELY...ESPECIALLY THE LOW TRACK AND ANY POSSIBLE CLEARING IN WARM SECTOR. BROUGHT HIGHS FOR THURSDAY UP IN THE FAR SOUTHEAST...WHICH HAS BEST SHOT AT GETTING INTO WARM SECTOR AIRMASS. THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM THE THREAT FOR THUNDERSTORMS...SOME OF WHICH MAY BE SEVERE...WILL QUICKLY DIMINISH AS THE AS THE LOW PRESSURE SYSTEM MOVES OFF TO THE NORTHEAST AND A COLD FRONT PUSHES THROUGH THE AREA. ALTHOUGH THE TSRA THREAT WILL BE ENDING THURSDAY NIGHT...EXPECT TO SEE CONSIDERABLE DEFORMATION ZONE PRECIP ON THE BACK SIDE OF THE CYCLONE. THE DEFORMATION ZONE...ALONG WITH A 500MB VORT MAX PUSHING ACROSS CENTRAL WI ON FRIDAY...WILL COMBINE TO KEEP PRECIP IN THE NE PORTIONS OF OUR CWA THROUGH THE DAY ON FRIDAY. WHILE A WIDESPREAD PRECIPITATION EVENT SEEMS VERY LIKELY THURSDAY AND THURSDAY NIGHT...THE GREATEST UNCERTAINTY IN THIS PERIOD IS WHETHER OR NOT ENOUGH INSTABILITY REACHES SE WI TO ALLOW FOR SEVERE CONVECTION. LONG TERM... SATURDAY...FORECAST CONFIDENCE IS HIGH RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE REGION. THE ATMOSPHERE SHOULD DRY OUT BY SATURDAY MORNING...SO EXPECTING TO SEE MOSTLY CLEAR SKIES AND TEMPS INTO THE MID 60S AWAY FROM LAKE MI. SUNDAY...FORECAST CONFIDENCE IS MEDIUM ANOTHER 500MB SHORTWAVE/VORT MAX WILL PUSH ACROSS THE REGION. AT THE SURFACE...A TROF/WEAK COLD FRONT TIED TO THE UPPER LEVEL SHORT WAVE WILL PUSH THOUGH SE WI ON SUNDAY NIGHT AND EARLY MONDAY MORNING. ALONG WITH THIS SFC TROF...MODELS PUSH A QUICK SLUG OF MOISTURE THROUGH THE AREA. EXPECT TO SEE RAIN IN THIS PERIOD...AND POSSIBLY SOME THUNDER IN THE WEST. MODELS IN GOOD AGREEMENT WITH THE TRACK OF THIS SFC TROF...THOUGH THERE IS STILL SOME UNCERTAINTY CONCERNING THE TIMING OF THE EVENT. ALL GUIDANCE HAS PRECIP ENDING BY 12Z MON. THEREFORE HAVE POPS IN THE GRIDS BEGINNING 12Z SUNDAY AND CONTINUING INTO MONDAY. MONDAY...FORECAST CONFIDENCE IS MEDIUM ANOTHER ROUND OF MID-LEVEL RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO THE REGION AS THE OVERNIGHT PRECIP MOVES OUT OF THE AREA. DURING THE DAY...ATMOSPHERE LOOKS DRY IN ALL GUIDANCE. SUPERBLEND INSISTS ON CHANCE POP MONDAY AFTERNOON SO WILL NOT COMPLETELY REMOVE PRECIP FROM GRIDS...BUT DID ADJUST DOWN TO SLIGHT CHANCE. TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS LOW AS A POTENT UPPER LEVEL TROF MOVES EAST ACROSS THE ROCKIES...A DEEP LOW PRESSURE SYSTEM IN THE SOUTHERN PLAINS WILL MOVE TO THE NORTHEAST. GUIDANCE SHOWS THE LOW MOVING INTO THE HIGH PLAINS...THOUGH THERE IS SOME UNCERTAINTY WITH THE TIMING OF THIS SYSTEM. AS THE LOW MOVES TO THE NORTHEAST...A WARM FRONT SHOULD PUSH THROUGH WISCONSIN AND BRING US A SHOT AT SOME PRECIPITATION. THERE IS SOME INSTABILITY WITH THIS SYSTEM...SO WILL BE KEEPING THUNDER IN THE GRIDS. AVIATION/00Z TAFS/... IFR/LIFR CEILINGS SHOULD LINGER TONIGHT INTO THURSDAY MORNING ACROSS TAF SITES. LIFR VISIBILITIES AT MILWAUKEE SHOULD IMPROVE TO IFR BY EARLY EVENING. AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS SHOULD MOVE ACROSS THE REGION FROM MIDDLE EVENING INTO THURSDAY MORNING. LIFR VISIBILITIES ARE POSSIBLE IN ANY OF THE STORMS...ALONG WITH SMALL HAIL. NORTHEAST WINDS WILL BECOME EAST TONIGHT...THEN WILL VARY DEPENDING ON WHERE WARM FRONT SETS UP THURSDAY. FOR NOW...WENT WITH SOUTH TO SOUTHWEST WINDS TO THE SOUTH AT TAF SITES FOR THURSDAY. WINDS WOULD BE NORTHEAST IF THE WARM FRONT AND LOW REMAIN SOUTH OF THE AREA...SO SOME UNCERTAINTY HERE. IF LOW AND WARM FRONT MAKE IT INTO SOUTHERN WISCONSIN...THEN THUNDERSTORMS FROM MIDDLE AFTERNOON THURSDAY TO MIDDLE EVENING THURSDAY MAY BECOME SEVERE. LARGE HAIL...DAMAGING WINDS AND TORNADOES ARE ALL POSSIBLE. UNCERTAINTY EXISTS WITH THESE THINGS OCCURRING...DEPENDING ON IF ENOUGH SUNSHINE DEVELOPS IN THE AFTERNOON. KEEP UP WITH THE LATEST FORECASTS. WINDS WILL SHIFT WEST NORTHWEST AND BECOME GUSTY BY LATER THURSDAY NIGHT. MARINE... SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN UNTIL 00Z THURSDAY. PERSISTENT NORTHEAST WINDS HELP REINFORCE THE 3 TO 5 FOOT WAVES ACROSS THE NEARSHORE WATERS UNTIL THEN. THE WINDS AND WAVES ARE EXPECTED TO WEAKEN SOMEWHAT TONIGHT INTO THURSDAY...AS LOW PRESSURE MOVES INTO THE REGION. WINDS SHOULD THEN BECOME GUSTY OUT OF THE WEST NORTHWEST THURSDAY NIGHT INTO FRIDAY...WITH TIGHT PRESSURE GRADIENT WITH THE PASSING LOW. SOME GUSTS TO 30 KNOTS ARE POSSIBLE...SO A SMALL CRAFT ADVISORY MAY BE NEEDED FOR THIS PERIOD. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...REM TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD THURSDAY NIGHT THROUGH WEDNESDAY...BSH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1200 AM CDT TUE APR 7 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 337 PM CDT MON APR 6 2015 CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED BROAD UPPER TROUGHING ALONG THE WEST COAST OF THE U.S....RIDGING ACROSS THE PLAINS AND THEN ZONAL FLOW ACROSS THE GREAT LAKES AND NEW ENGLAND. A STATIONARY SURFACE FRONTAL ZONE EXISTS UNDERNEATH THE RIDGING AND ZONAL FLOW NEAR I-80...WITH A MID LEVEL FRONTOGENESIS AXIS WELL TO THE NORTH ACROSS CENTRAL MN AND NORTHERN WI. SOME PRECIPITATION WAS FALLING OUT OF THIS AXIS...BUT A NORTHEAST FLOW OF CANADIAN DRY AIR FROM HIGH PRESSURE IN ONTARIO HAS DIMINISHED MUCH OF THE PRECIPITATION. THE 12Z GRB SOUNDING AND ESPECIALLY THE INL SOUNDING SHOWED THAT DRY AIR NICELY. SOME OF THAT DRY AIR INFILTRATED INTO THE FORECAST AREA THIS MORNING TO CLEAR SKIES OUT FROM THE STRATUS. HOWEVER...MID AND HIGH CLOUDS WERE SPREADING BACK OVER THE AREA FROM A BROAD WARM ADVECTION REGIME UNDER THE UPPER RIDGE...AND THEN SOME LOW STRATUS WAS TRYING TO BACK INTO THE AREA FROM NORTHEAST WI. A FEW SHOWERS AND STORMS HAVE BEEN GOING ON NEAR WATERLOO IA MARCHING EAST-NORTHEAST...ASSOCIATED WITH A WEAK SHORTWAVE INTERACTING WITH THE WARM/MOIST ADVECTION. QUITE THE LOW LEVEL THERMAL TEMPERATURE GRADIENT EXITS ACROSS THE FORECAST AREA. PER RAP 925MB TEMPS... READINGS NORTH OF HIGHWAY 29 ARE AROUND 0C COMPARED TO 8C OVER NORTHERN IA AND SOUTHERN WI. FARTHER SOUTHWEST 20C PLUS 925MB READINGS EXISTS IN WESTERN KS. THE UPPER RIDGING OVER THE PLAINS IS PROGGED TO PROGRESS OVER THE FORECAST AREA OVER THE NEXT 24 HOURS IN RESPONSE TO THE TROUGH ALONG THE WEST COAST MOVING INLAND SLIGHTLY. THIS WILL PUT THE FORECAST AREA IN A WARM/MOISTURE ADVECTION ZONE ALOFT. ISENTROPIC LIFT FIELDS SHOW THIS NICELY...ESPECIALLY DURING THE DAY TUESDAY AND EVEN MORESO IN THE AFTERNOON WEST OF THE MS RIVER ON 290-300K SURFACES. THUS...WE SHOULD SEE A CONTINUOUS INCREASE AND THICKENING OF CLOUD COVER. AN EAST TO NORTHEAST LOW LEVEL FLOW BRINGING IN DRIER AIR FROM ONTARIO WILL HAMPER SOME OF THE PRECIPITATION PRODUCTION...OR MAKE IT SPOTTY...UNTIL TUESDAY AFTERNOON WHEN PRECIPITABLE WATER SURGES UP TO 0.75 TO 1 INCH. THEREFORE HIGHEST PRECIPITATION CHANCES ARE PLACED IN THE LATE TUE AFTERNOON TIME PERIOD. THE INCREASE IN CLOUD COVER WOULD HELP TO KEEP TEMPERATURES UP. HOWEVER...THE EASTERLY FLOW OF COOLER DRY AIR IN CONJUNCTION WITH SPOTTY PRECIPITATION WILL WORK TOGETHER TO KNOCK TEMPERATURES DOWN. AS SUCH...925MB TEMPS FALL TO -2C NORTH TO +4C SOUTH BY 12Z TUE AND LINGER NEAR THERE THROUGH MUCH OF TUESDAY. READINGS MAY STRUGGLE TO CLIMB MUCH ON TUESDAY WITH LIMITED SUNSHINE...AND THE MORE WIDESPREAD LATE AFTERNOON RAIN NOT HELPING MATTERS. THE AFOREMENTIONED TEMPERATURES BRING ABOUT PRECIPITATION TYPE CONCERNS ACROSS TAYLOR/CLARK COUNTY WHERE THE COLDEST AIR EXISTS. SURFACE TEMPERATURES LOOK TO FALL BACK BELOW FREEZING TONIGHT. FOR THE EVENING ICE IS SUGGESTED IN THE CLOUDS...SO THERE COULD BE A RAIN/SNOW MIX. THEN DURING THE OVERNIGHT AND MUCH OF TUESDAY MORNING...THE ICE IN THE CLOUDS DEPARTS TO THE NORTHEAST...LEAVING THE POTENTIAL FOR FREEZING RAIN WITH ANY PRECIPITATION. HOWEVER...ITS POSSIBLE THAT THE LOSS OF ICE MAY END UP ENDING THE PRECIPITATION ENTIRELY AS SUGGESTED BY THE 06.12Z GFS. THEREFORE...HAVE NOT ISSUED ANY WINTER WEATHER OR FREEZING RAIN ADVISORY AT THIS TIME. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 337 PM CDT MON APR 6 2015 THERE ARE TWO MAIN PERIODS OF WEATHER FOCUS...TUESDAY NIGHT AND LATE WEDNESDAY INTO THURSDAY NIGHT. A SHORTWAVE TROUGH IS PROGGED TO CROSS MINNESOTA AND WISCONSIN TUESDAY NIGHT...BRINGING WITH IT A DECENT SURGE OF 850MB MOISTURE TRANSPORT / ISENTROPIC LIFT. MOISTURE SHOULD BE PLENTIFUL WITH PRECIPITABLE WATER OF 0.75-1 INCH AND SATURATED SOUNDINGS. THEREFORE CONDITIONS LOOK FAVORABLE FOR RAIN AND RAISED CHANCES UP TO 80. BEST JUXTAPOSITION OF LIFT IS SITUATED SOUTH OF I-90 DURING THE EVENING. ADDITIONALLY...WITH MUCAPE VALUES IN 200-500 J/KG RANGE DURING THE EVENING ROOTED ABOVE 850MB AND LITTLE CAP...EXPECTING AT LEAST ISOLATED THUNDERSTORMS TO OCCUR. PRECIPITATION SHOULD DIMINISH WEST TO EAST AFTER MIDNIGHT AS THE LIFT MOVES OFF TO THE EAST AND SUBSIDENCE COMES IN. PRECIPITATION TYPE FOR THE MOST PART LOOKS TO BE RAIN WITH PLENTY OF WARM AIR IN PLACE...EXCEPT FOR TAYLOR COUNTY SHOULD THE PRECIPITATION GET UP THERE. IN TAYLOR COUNTY...THE AIR MAY BE COLD ENOUGH TO ALLOW FOR SLEET OR FREEZING RAIN. A BRIEF BREAK LOOKS TO OCCUR FOR MUCH OF THE DAY WEDNESDAY...UNTIL THE LATER AFTERNOON HOURS. THIS IS WHEN THE TROUGHING ALONG THE U.S. WEST COAST BEGINS THE MARCH TOWARDS THE PLAINS...PUSHING ANOTHER SURGE OF 850MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE FORECAST AREA. PRECIPITABLE WATER ALSO CLIMBS BACK TO 0.75-1 INCH AFTER FALLING TO NEAR 0.5 INCH DURING THE MORNING. THE SURGE OF MOISTURE TRANSPORT IS MORE IMPRESSIVE FOR WEDNESDAY NIGHT COMPARED TO TUESDAY NIGHT...AND IT APPEARS EVERYWHERE SHOULD PICK OF PRECIPITATION. ANTICIPATING RAIN TO BE THE MAIN PRECIPITATION TYPE WITH ANY MIXED PRECIPITATION STAYING JUST NORTH OF THE FORECAST AREA. SHOULD SEE SOME THUNDERSTORMS AGAIN SOUTH OF I-90 AS MUCAPE ABOVE ANY ELEVATED CAPPING INCREASES TO 200-500 J/KG. AS WE HEAD INTO THURSDAY...MODELS BEGIN TO SPREAD OUT ON THE SPEED AND STRENGTH OF THE UPPER TROUGH...IMPACTING THE TRACK OF THE SURFACE SYSTEM AND WARM SECTOR. THE ECMWF HAS BEEN HOLDING FAIRLY STEADY WITH A MORE POSITIVE TILT TROUGH AND FARTHER SOUTHEAST SURFACE LOW. ON THE OTHER HAND...THE 06.12Z GFS/CANADIAN/NAM ARE MORE NEUTRAL AND EVEN NEGATIVE TILT IN THE NAM...RESULTING IN A STRONGER SURFACE LOW. HARD TO SAY WHAT SCENARIO WILL PAN OUT...BUT WITH THE ECMWF ENSEMBLE MEAN SIMILAR TO THE ECMWF...FEEL THE ECMWF MAY BE MORE LIKELY TO WORK OUT. IN ANY EVENT...PRECIPITATION LOOKS LIKE A GOOD BET TO CONTINUE ON THURSDAY...BUT OF A LIGHTER VARIETY AS THE FORCING DIMINISHES TO JUST THE DPVA FROM THE UPPER TROUGH. TYPE LOOKS TO HOLD AS RAIN. AGAIN THUNDERSTORMS ARE POSSIBLE SOUTH OF I-90...AND IF THE FARTHER NORTHWEST 06.12Z CANADIAN/GFS PAN OUT COULD EVEN SEE A SEVERE RISK IN FAR NORTHEAST IA/SOUTHWEST WI. SOMETHING TO MONITOR. TEMPERATURES EXTREMELY TRICKY FOR THURSDAY AS THEY DEPEND ON THE LOW TRACK. FOLLOWED A MODEL CONSENSUS FOR NOW. THURSDAY NIGHT IS DOMINATED BY A COLD CONVEYOR BELT IMPACTING THE NORTHWEST HALF OF THE FORECAST AREA...WHILE A DRY SLOT ACCOMPANYING THE UPPER TROUGH TRIES TO MOVE THROUGH THE SOUTHEAST HALF. UNDER THE COLD CONVEYOR BELT COULD SEE PRECIPITATION MIX WITH OR CHANGE OVER TO SNOW...ESPECIALLY AS THE NIGHT WEARS ON AS TEMPERATURES COOL. HOWEVER...BY THE TIME PRECIPITATION BEGINS TO SWITCH OVER...IT COULD ALSO BE ENDING. THUS...NO SNOW ACCUMULATION IS ANTICIPATED AT THIS TIME. STILL KEPT SOME PRECIPITATION CHANCES IN FOR FRIDAY BASED ON A MODEL CONSENSUS BUT NEW 06.12Z ECMWF/GFS WOULD SUGGEST A DRIER FORECAST AND OUR FORECAST MAY BE ABLE TO BE DRIED OUT. ALTHOUGH COOL AIR COMES IN BEHIND THE UPPER TROUGH FOR FRIDAY...POTENTIAL EXISTS FOR MORE SUN COMPARED TO THURSDAY AND THUS HIGHS FOR MANY LOCATIONS END UP SIMILAR. FOR THE WEEKEND INTO EARLY NEXT WEEK. GOOD MODEL AGREEMENT EXISTS AMONGST THE 06.12Z GFS/ECMWF/CANADIAN FOR UPPER RIDGING TO BUILD INTO THE AREA FRIDAY NIGHT AND SATURDAY...RESULTING IN DRY CONDITIONS. FRIDAY NIGHT COULD BE ON THE COOL SIDE WITH SURFACE HIGH IN PLACE AND CLEARING. MAY EVEN END UP WITH SOME RADIATION FOG. TEMPERATURES SHOULD REBOUND NICELY ON SATURDAY WITH SUN. THEN ON SUNDAY AND MONDAY ANOTHER TROUGH THAT FORMS OVER THE WESTERN U.S. LIFTS INTO/AFFECTS THE REGION. AS A RESULT PRECIPITATION CHANCES RETURN. TYPE FOR THE MOST PART SHOULD BE RAIN. WARM ADVECTION HELPS TO PUSH TEMPERATURES TO NEAR OR SLIGHTLY ABOVE SEASONABLE NORMALS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1155 PM CDT MON APR 6 2015 KEPT TREND OF LOWERING CEILINGS TONIGHT AND OBSERVATIONS SEEM TO SUPPORT THIS WITH SCT015 SHOWING UP NOW IN WI JUST EAST OF KLSE. THIS WILL PROGRESS WEST TONIGHT AND BE COMMON BY SUNRISE. WINDS FROM THE EAST WILL BE GUSTY TUESDAY AND A STRONG WEATHER SYSTEM MOVES INTO IOWA. SOME INSTABILITY WILL BE PRESENT NEAR THE TAF SITES BY LATE TUESDAY AS STRONG LIFT COMES INTO THE AREA...WITH RAIN EXPECTED. DID NOT INCLUDE THUNDER AT THE TAF SITES YET...BUT FUTURE FORECASTS WILL HAVE TO ASSESS THIS FOR 22Z+ TUESDAY. ALSO...SOME DRIZZLE MAY BE AROUND THE TAF SITES AFTER 18Z TUESDAY...BUT DO NOT BELIEVE IT WILL BE A FACTOR TO AVIATION. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
456 AM MDT TUE APR 7 2015 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 159 AM MDT TUE APR 7 2015 IF YOU ARE AN AFICIONADO OF THE GAMUT OF WEATHER PHENOMENON...YOU WILL LOVE THE NEXT FEW DAYS. TODAY...AS EXPECTED BY OUR FORECAST TEAM...LOW CLOUDS AND FOG HAVE DEVELOPED ALONG AND EAST OF THE LARAMIE RANGE AND INTERSTATE 25 CORRIDOR WITH MOIST LOW LEVEL UPSLOPE. HAVE FOLLOWED THE CURRENT AREAL FOG COVERAGE AND BOUNDARY LAYER PROGS FOR PAINTING FOG AREAS THIS MORNING. FOR THIS AFTERNOON...ATTENTION THEN SHIFTS TO AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS. DECENT SOUTHWEST FLOW ALOFT WITH WEAK SHORTWAVE TROUGH MOVING NORTHEASTWARD OVER OUR COUNTIES NEAR PEAK HEATING...WITH LOW LEVEL EAST SOUTHEASTERLIES ADVECTING LOW LEVEL MOISTURE TO THE BASE OF THE LARAMIE RANGE. BASED ON THE LOCATIONS OF THE 850 MB AND 700 MB THETA-E RIDGES...FROM DOUGLAS TO CHEYENNE TO SIDNEY AND UPWARD VERTICAL MOTION...EXPECT ISOLATED TO SCATTERED AFTERNOON SHOWERS ALONG THIS THETA-E RIDGE...MOST NUMEROUS FROM DOUGLAS TO WHEATLAND WHERE UVV AND THETA-E RIDGING IS MOST COINCIDENT. ENOUGH INSTABILITY FOR A FEW THUNDERSTORMS AS WELL. TONIGHT...FLOW ALOFT BACKS IN ADVANCE OF THE APPROACHING STRONGER SHORTWAVE TROUGH...WITH MOIST LOW LEVEL UPSLOPE SOUTHEAST WINDS CONTINUING TO ADVECT MOISTURE ACROSS OUR EASTERN PLAINS ALONG AND EAST OF INTERSTATE 25. WILL SEE AN INCREASE IN AREAL COVERAGE OF FOG ALONG AND EAST OF INTERSTATE 25...AND MAY EVEN SEE SOME AREAS OF DENSE FOG DEPENDING ON THE AREAL COVERAGE OF LOW CLOUDS AND IF ISOLATED SHOWERS ARE MINIMIZED. WEDNESDAY...WOULD NOT BE SURPRISED TO SEE OUR TEAM ISSUE OUR FIRST SEVERE THUNDERSTORM WARNING OF THE SEASON IN THE AFTERNOON OR EVENING. IMPRESSIVE AND ROBUST SHORTWAVE TROUGH ALOFT MOVES OVER CENTRAL WYOMING IN THE AFTERNOON...WITH AN IMPRESSIVE INVERTED SURFACE TROUGH AXIS ACROSS OUR FAR EASTERN WYOMING COUNTIES. QUITE PRONOUNCED 850 MB THETA-E RIDGE AXIS EXTENDS ALONG AND JUST WEST OF THE WYOMING AND NEBRASKA STATE LINE IN THE AFTERNOON...WITH ROARING LEFT FRONT QUADRANT OF THE 300 MB JET STREAKING IN FROM SOUTHWEST TO NORTHEAST. ALTHOUGH CAPE WILL NOT BE OVERLY IMPRESSIVE...WITH PROGGED 500-300 MB AND 700-500 MB QUASIGEOSTROPHIC LIFT...TIMING COINCIDENT WITH PEAK HEATING...AND SHEAR...WE EXPECT SCATTERED AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25...WITH A FEW STORMS BECOMING STRONG TO SEVERE FROM LATE AFTERNOON THROUGH EARLY EVENING AND THE BEST THREAT FOR STRONGEST THUNDERSTORMS FROM LUSK TO TORRINGTON TO PINE BLUFFS IN THE AFTERNOON...THEN INTO THE PANHANDLE IN THE EVENING. WIDESPREAD SHOWERS FOCUSED ALONG THE INSTABILITY AXIS IN THE AFTERNOON EAST OF INTERSTATE 25. WEDNESDAY NIGHT...WITH PLENTY OF LOW AND MID LEVEL MOISTURE AS FUEL...AND THE ENERGIZED PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVING OVERHEAD...ALONG WITH A POTENT PACIFIC ORIGIN COLD FRONT PASSAGE AND BAROCLINIC BAND...WILL SEE WIDESPREAD SHOWERS EAST OF I-25 WITH LESSER COVERAGE WEST OF I-25. PRECIPITATION WILL SWITCH OVER TO SNOW WITH MINIMAL ACCUMULATIONS AT LOWER ELEVATIONS...THOUGH WE MAY SEE 2 TO 5 INCHES OF SNOW OVER THE SNOWY RANGE AND SIERRA MADRES AND NORTHERN LARAMIE RANGE. WILL SEE AREAS OF FOG DEVELOP...THOUGH MINIMIZED BY THE WIDESPREAD SNOW SHOWERS AFTER MIDNIGHT. WINDY AND CHILLY. TOTAL SNOWFALL OF 3 TO 7 INCHES EXPECTED BY FRIDAY MORNING OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES. THURSDAY...AREAL COVERAGE OF SHOWERS WILL WANE IN THE MORNING AND EARLY AFTERNOON AS THE SHORTWAVE TROUGH ALOFT DYNAMICS MOVE FAR TO OUR EAST...THOUGH IT WILL BE A WINDY AND COOL EARLY APRIL DAY WITH MAXIMUM TEMPERATURES IN THE 40S AT LOWER ELEVATIONS AND 30S OVER THE MOUNTAINS...PER PROGGED LOW AND MID LEVEL GRADIENTS...700 MB TEMPERATURES AND THICKNESSES. THURSDAY NIGHT...ANOTHER WEAKER SHORTWAVE TROUGH ALOFT MOVES OVER WYOMING WITH ONLY WEAK UPWARD VERTICAL MOTION PRODUCING ISOLATED TO SCATTERED SHOWERS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES. DRY ELSEWHERE. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 330 AM MDT TUE APR 7 2015 WEAK DEPARTING UPPER LEVEL TROUGH EARLY FRIDAY COULD BRING SOME ISOLATED SHOWERS TO THE MOUNTAINS THROUGH THE AFTERNOON HOURS. MOST LOCATIONS THOUGH SHOULD REMAIN DRY. 700MB TEMPERATURES ON THE REBOUND...CLIMBING TO +4C BY SATURDAY. SHOULD SEE UPPER 60S PRETTY COMMON SATURDAY IN THE PANHANDLE AND LOW 60S OUT WEST. GFS AND ECMWF SHOWING A WINDY PERIOD AS 700MB WINDS CONTINUE TO INCREASE. THIS IN RESPONSE TO A LOW PRESSURE SYSTEM TRACKING ACROSS THE SOUTHERN CANADIAN PROVINCES SUNDAY INTO MONDAY. IN FACT...GFS FORECAST 50+KTS AT 700MB MONDAY NIGHT...SO WE COULD BE LOOKING AT WIND HEADLINES FOR OUR WIND PRONE AREAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 454 AM MDT TUE APR 7 2015 LATEST HRRR GUIDANCE USED FOR THE 12Z TAFS. IFR/LIFR CONDITIONS FOR MUCH OF THE MORNING. DID STRAY FROM HRRR GUIDANCE ON KCYS A LITTLE. DO THINK LOW CONDITIONS WILL STAY IN A LITTLE LONGER HERE AS SOUTH TO SOUTHEAST UPSLOPE WINDS PREVAIL. LOOK FOR A REPEAT OF STRATUS AND FOG TONIGHT FOR THE NEBRASKA PANHANDLE AND AREAS EAST OF THE LARAMIE RANGE. && .FIRE WEATHER... ISSUED AT 159 AM MDT TUE APR 7 2015 FOR TODAY...SOME CONCERN WEST OF INTERSTATE 25 WHERE HUMIDITIES IN PORTIONS OF CARBON COUNTY WILL RANGE FROM 15 TO 20 PERCENT IN THE AFTERNOON WITH GUSTY SOUTHWEST WINDS. MINIMAL CONCERNS ELSEWHERE DUE TO HIGHER HUMIDITIES. WEDNESDAY...HUMIDITIES WILL BE ABOVE CRITICAL LEVELS...THOUGH FIRE WEATHER INTERESTS WILL NEED TO WATCH FOR LIGHTNING STRIKES FROM ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND EAST OF INTERSTATE 25. HUMIDITIES DECREASING AGAIN OVER THE WEEKEND WITH SOME GUSTY WINDS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
333 AM MDT TUE APR 7 2015 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 159 AM MDT TUE APR 7 2015 IF YOU ARE AN AFICIONADO OF THE GAMUT OF WEATHER PHENOMENON...YOU WILL LOVE THE NEXT FEW DAYS. TODAY...AS EXPECTED BY OUR FORECAST TEAM...LOW CLOUDS AND FOG HAVE DEVELOPED ALONG AND EAST OF THE LARAMIE RANGE AND INTERSTATE 25 CORRIDOR WITH MOIST LOW LEVEL UPSLOPE. HAVE FOLLOWED THE CURRENT AREAL FOG COVERAGE AND BOUNDARY LAYER PROGS FOR PAINTING FOG AREAS THIS MORNING. FOR THIS AFTERNOON...ATTENTION THEN SHIFTS TO AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS. DECENT SOUTHWEST FLOW ALOFT WITH WEAK SHORTWAVE TROUGH MOVING NORTHEASTWARD OVER OUR COUNTIES NEAR PEAK HEATING...WITH LOW LEVEL EAST SOUTHEASTERLIES ADVECTING LOW LEVEL MOISTURE TO THE BASE OF THE LARAMIE RANGE. BASED ON THE LOCATIONS OF THE 850 MB AND 700 MB THETA-E RIDGES...FROM DOUGLAS TO CHEYENNE TO SIDNEY AND UPWARD VERTICAL MOTION...EXPECT ISOLATED TO SCATTERED AFTERNOON SHOWERS ALONG THIS THETA-E RIDGE...MOST NUMEROUS FROM DOUGLAS TO WHEATLAND WHERE UVV AND THETA-E RIDGING IS MOST COINCIDENT. ENOUGH INSTABILITY FOR A FEW THUNDERSTORMS AS WELL. TONIGHT...FLOW ALOFT BACKS IN ADVANCE OF THE APPROACHING STRONGER SHORTWAVE TROUGH...WITH MOIST LOW LEVEL UPSLOPE SOUTHEAST WINDS CONTINUING TO ADVECT MOISTURE ACROSS OUR EASTERN PLAINS ALONG AND EAST OF INTERSTATE 25. WILL SEE AN INCREASE IN AREAL COVERAGE OF FOG ALONG AND EAST OF INTERSTATE 25...AND MAY EVEN SEE SOME AREAS OF DENSE FOG DEPENDING ON THE AREAL COVERAGE OF LOW CLOUDS AND IF ISOLATED SHOWERS ARE MINIMIZED. WEDNESDAY...WOULD NOT BE SURPRISED TO SEE OUR TEAM ISSUE OUR FIRST SEVERE THUNDERSTORM WARNING OF THE SEASON IN THE AFTERNOON OR EVENING. IMPRESSIVE AND ROBUST SHORTWAVE TROUGH ALOFT MOVES OVER CENTRAL WYOMING IN THE AFTERNOON...WITH AN IMPRESSIVE INVERTED SURFACE TROUGH AXIS ACROSS OUR FAR EASTERN WYOMING COUNTIES. QUITE PRONOUNCED 850 MB THETA-E RIDGE AXIS EXTENDS ALONG AND JUST WEST OF THE WYOMING AND NEBRASKA STATE LINE IN THE AFTERNOON...WITH ROARING LEFT FRONT QUADRANT OF THE 300 MB JET STREAKING IN FROM SOUTHWEST TO NORTHEAST. ALTHOUGH CAPE WILL NOT BE OVERLY IMPRESSIVE...WITH PROGGED 500-300 MB AND 700-500 MB QUASIGEOSTROPHIC LIFT...TIMING COINCIDENT WITH PEAK HEATING...AND SHEAR...WE EXPECT SCATTERED AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25...WITH A FEW STORMS BECOMING STRONG TO SEVERE FROM LATE AFTERNOON THROUGH EARLY EVENING AND THE BEST THREAT FOR STRONGEST THUNDERSTORMS FROM LUSK TO TORRINGTON TO PINE BLUFFS IN THE AFTERNOON...THEN INTO THE PANHANDLE IN THE EVENING. WIDESPREAD SHOWERS FOCUSED ALONG THE INSTABILITY AXIS IN THE AFTERNOON EAST OF INTERSTATE 25. WEDNESDAY NIGHT...WITH PLENTY OF LOW AND MID LEVEL MOISTURE AS FUEL...AND THE ENERGIZED PROGRESSIVE SHORTWAVE TROUGH ALOFT MOVING OVERHEAD...ALONG WITH A POTENT PACIFIC ORIGIN COLD FRONT PASSAGE AND BAROCLINIC BAND...WILL SEE WIDESPREAD SHOWERS EAST OF I-25 WITH LESSER COVERAGE WEST OF I-25. PRECIPITATION WILL SWITCH OVER TO SNOW WITH MINIMAL ACCUMULATIONS AT LOWER ELEVATIONS...THOUGH WE MAY SEE 2 TO 5 INCHES OF SNOW OVER THE SNOWY RANGE AND SIERRA MADRES AND NORTHERN LARAMIE RANGE. WILL SEE AREAS OF FOG DEVELOP...THOUGH MINIMIZED BY THE WIDESPREAD SNOW SHOWERS AFTER MIDNIGHT. WINDY AND CHILLY. TOTAL SNOWFALL OF 3 TO 7 INCHES EXPECTED BY FRIDAY MORNING OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES. THURSDAY...AREAL COVERAGE OF SHOWERS WILL WANE IN THE MORNING AND EARLY AFTERNOON AS THE SHORTWAVE TROUGH ALOFT DYNAMICS MOVE FAR TO OUR EAST...THOUGH IT WILL BE A WINDY AND COOL EARLY APRIL DAY WITH MAXIMUM TEMPERATURES IN THE 40S AT LOWER ELEVATIONS AND 30S OVER THE MOUNTAINS...PER PROGGED LOW AND MID LEVEL GRADIENTS...700 MB TEMPERATURES AND THICKNESSES. THURSDAY NIGHT...ANOTHER WEAKER SHORTWAVE TROUGH ALOFT MOVES OVER WYOMING WITH ONLY WEAK UPWARD VERTICAL MOTION PRODUCING ISOLATED TO SCATTERED SHOWERS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES. DRY ELSEWHERE. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 330 AM MDT TUE APR 7 2015 WEAK DEPARTING UPPER LEVEL TROUGH EARLY FRIDAY COULD BRING SOME ISOLATED SHOWERS TO THE MOUNTAINS THROUGH THE AFTERNOON HOURS. MOST LOCATIONS THOUGH SHOULD REMAIN DRY. 700MB TEMPERATURES ON THE REBOUND...CLIMBING TO +4C BY SATURDAY. SHOULD SEE UPPER 60S PRETTY COMMON SATURDAY IN THE PANHANDLE AND LOW 60S OUT WEST. GFS AND ECMWF SHOWING A WINDY PERIOD AS 700MB WINDS CONTINUE TO INCREASE. THIS IN RESPONSE TO A LOW PRESSURE SYSTEM TRACKING ACROSS THE SOUTHERN CANADIAN PROVINCES SUNDAY INTO MONDAY. IN FACT...GFS FORECAST 50+KTS AT 700MB MONDAY NIGHT...SO WE COULD BE LOOKING AT WIND HEADLINES FOR OUR WIND PRONE AREAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1115 PM MDT MON APR 6 2015 LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR STRATUS MOVING INTO THE PANHANDLE AND INTO THE EXTREME EAST SOUTHEAST WYOMING WILL PERSIST THROUGH THE OVERNIGHT HOURS. COULD BE A FAIRLY PROLONGED EVENT. POSSIBLY LASTING IN THE PANHANDLE INTO THE EARLY AFTERNOON HOURS. && .FIRE WEATHER... ISSUED AT 159 AM MDT TUE APR 7 2015 FOR TODAY...SOME CONCERN WEST OF INTERSTATE 25 WHERE HUMIDITIES IN PORTIONS OF CARBON COUNTY WILL RANGE FROM 15 TO 20 PERCENT IN THE AFTERNOON WITH GUSTY SOUTHWEST WINDS. MINIMAL CONCERNS ELSEWHERE DUE TO HIGHER HUMIDITIES. WEDNESDAY...HUMIDITIES WILL BE ABOVE CRITICAL LEVELS...THOUGH FIRE WEATHER INTERESTS WILL NEED TO WATCH FOR LIGHTNING STRIKES FROM ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND EAST OF INTERSTATE 25. HUMIDITIES DECREASING AGAIN OVER THE WEEKEND WITH SOME GUSTY WINDS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1118 PM MDT MON APR 6 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 255 PM MDT MON APR 6 2015 TONIGHT: LATEST WATER VAPOR LOOP WAS SHOWING THE UPPER LEVEL TROF STARTING TO REACH THE PACIFIC COASTLINE WHILE A 100KT JET CONTINUES TO NOSE INTO THE BASE OF THIS TROF. ONE INTERESTING NOTE ABOUT THIS TROF IS THAT THERE IS NOT ANY EVIDENCE OF UPSTREAM ENERGY DIGGING BEHIND IT BESIDES THE CURRENT JET STREAK. IN ADDITION...THERE IS NOT A LOT OF JET ENERGY IN THE SOUTHERN STREAM WHICH WILL NOT FAVOR A DIGGING TROF. AS A RESULT...WE SHOULD SEE THIS TROF CONTINUE TO SHIFT EAST DURING THE NEXT COUPLE OF DAYS. AHEAD OF THE TROF...THE SURFACE LEE SIDE TROF WILL BECOME MORE ESTABLISHED AND START PULLING LOW LEVEL MOISTURE INTO AREAS EAST OF THE LARAMIE RANGE. WE WILL SEE THE EFFECTS OF THIS LOW LEVEL MOISTURE LATER TONIGHT IN THE NEBRASKA PANHANDLE WHERE THEY MAY EXPERIENCE LOW CLOUDS/FOG/LIGHT DRIZZLE. NOT REAL CONFIDENT ABOUT THE DRIZZLE POTENTIAL SINCE IT APPEARS LIKE THE MOISTURE IS FAIRLY SHALLOW. HOWEVER...WE COULD SEE THE VISIBILITY DROP TO A 1 MILE IN A FEW SPOTS. TUESDAY-TUESDAY NIGHT: LOW CLOUDS/FOG WILL GRADUALLY SHIFT EAST DURING THE COURSE OF THE MORNING AS THE BOUNDARY LAYER BEGINS TO MIX OUT. ACROSS THE WESTERN HALF OF THE AREA...IT WILL CONTINUE TO BE DRY WITH GUSTY WINDS. HOWEVER...WE MAY START TO SEE SOME ISOLATED CONVECTION DEVELOP ALONG THE NORTHERN LARAMIE DURING THE EARLY AFTERNOON AS A JET STREAK MOVES THROUGH THAT REGION AND YIELDS TO SOME UPPER LEVEL DIFFLUENCE. THIS IS A GOOD SETUP FOR SOME SCATTERED ELEVATED THUNDERSTORMS WHICH MAY CONTAIN SOME DRY LIGHTNING IN THE NORTHERN LARAMIE RANGE. WE MAY HAVE TO WATCH THIS POTENTIAL DURING THE AFTERNOON. THESE THUNDERSTORMS SHOULD PUSH OFF THE MOUNTAINS BY MID AFTERNOON AND LIFT NORTHEAST BEFORE DISSIPATING EARLY IN THE EVENING. NOT EXPECTING ANYTHING SEVERE AT THIS TIME DUE TO LIMITED SHEAR. LOW CLOUDS/FOG WILL ALSO DEVELOP IN AREAS EAST OF THE LARAMIE RANGE OVERNIGHT DUE TO GOOD UPSLOPE FLOW IN ADVANCE OF THE UPPER LEVEL TROF. WEDNESDAY-WEDNESDAY NIGHT: THE MODELS ARE TRENDING TOWARDS A MUCH MORE PROGRESSIVE SYSTEM COMPARED TO PREVIOUS RUNS WITH THE SYSTEM REALLY NOT SHOWING ANY SIGNS OF WRAPPING UP. HOWEVER...THERE IS STILL GOOD POTENTIAL FOR STRONG/SEVERE THUNDERSTORMS DEVELOPING MAINLY EAST OF THE LARAMIE RANGE DURING THE AFTERNOON...DUE TO THE JUXTAPOSITION OF THE SURFACE LEE TROF AND A POTENTIAL VORTICITY ANOMALY MOVING ACROSS. THESE STORMS COULD EVOLVE INTO A CLUSTER AND SHIFT EAST-SOUTHEAST DURING THE COURSE OF THE EVENING IN ASSOCIATION WITH THE WAVE. AFTER THIS CLUSTER MOVES PUSHES EAST...WE WILL SEE THE COLD FRONT START PLUNGING INTO AREAS EAST OF THE LARAMIE RANGE AND BRING COLDER TEMPERATURES WITH THE RAIN POSSIBLY CHANGING OVER TO SNOW IN THE HIGHER ELEVATIONS OF WYOMING. HOWEVER...THIS PRECIPITATION WILL MOST LIKELY BE SHORT-LIVED DUE TO QUICK FRONTAL FORCING. THE PANHANDLE STILL LOOKS LIKE IT WILL SEE THE MOST PRECIPITATION IN THE FORM OF RAINFALL. HOWEVER...THE PINE RIDGE WHERE THEY MAY SEE SOME SNOW ACCUMULATION WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 255 PM MDT MON APR 6 2015 LONG RANGE MODELS ARE IN POOR AGREEMENT AND ARE STRUGGLING WITH THE OVERALL PATTERN IN THE EXTENDED. EVEN ON THURSDAY...MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION AND POSITION OF THE PACIFIC STORM SYSTEM PUSHING EASTWARD INTO THE NORTH-CENTRAL GREAT PLAINS. ALTHOUGH THE GENERAL TREND HAS BEEN MORE PROGRESSIVE AND A BIT FURTHER NORTH...IT IS STILL UNCLEAR HOW WIDESPREAD THE PRECIPITATION WILL BE. A FEW MODELS STILL INDICATE RAPID CYCLOGENESIS OVER EASTERN COLORADO...BUT OTHERS SUCH AS THE NAM SHOW LITTLE INDICATION OF ANY CYCLOGENESIS EXCEPT MUCH FURTHER SOUTH. HOWEVER...BECOMING LESS CONFIDENT THAT A MAJOR STORM WILL IMPACT THE REGION DURING THE MIDDLE OF THE WEEK GIVEN CURRENT MODEL TRENDS. WILL NEED TO MONITOR THE POSSIBILITY OF PORTIONS OF THE FORECAST AREA GETTING CLIPPED BY SOME LOCALLY HEAVY RAIN/SNOWFALL THROUGH EARLY THURSDAY MORNING. OTHERWISE...LOWERED POP THROUGH THURSDAY EVENING FOR NOW. TEMPERATURES WILL BE BELOW NORMAL ON THURSDAY AS WELL WITH HIGHS IN THE 30S TO MID 40S. FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS GENERALLY SHOW ZONAL FLOW OVER THE AREA WITH A CHANCE OF AFTERNOON SHOWERS AND ISOLATED THUNDER POSSIBLE. MODEL SOLUTION GREATLY DIVERGE ON SUNDAY AND MONDAY OF NEXT WEEK...WITH THE GEM AND GFS SHOWING A STRONG UPPER LEVEL TROUGH PUSHING EASTWARD. THE GFS SHOWS A STRONG SHORTWAVE LIFTING NORTHEAST AHEAD OF THIS MAIN SYSTEM...WHILE THE GEM AND ECMWF SHOW THIS SHORTWAVE MUCH FURTHER SOUTH. BY MONDAY...THE GFS SHOWS THE MAIN UPPER LEVEL TROUGH DIGGING SOUTH AND STALLING AS THE SOUTHERN SHORTWAVE LIFTS NORTH...FORMING A DEEP UPPER LEVEL LOW OVER THE DAKOTAS AND EASTERN WYOMING. THE ECMWF IS MUCH DIFFERENT...SHOWING A CONTINUATION OF NEAR ZONAL FLOW AS THE MAIN UPPER LEVEL TROUGH LIFTS NORTHEAST BUT IS MUCH WEAKER COMPARED TO THE GFS. THE FORECAST ENSEMBLES ALSO SHOW ALL THIS UNCERTAINTY...WITH A WIDE VARIETY OF SOLUTION. IN ADDITION...SOME ENSEMBLE MEMBERS SHOW THE SOUTHERN SHORTWAVE PUSHING NORTHWARD...STALLING...AND FORMING A CLOSED LOW OVER EASTERN COLORADO...WHICH WILL HAVE TO BE MONITORED. OTHERWISE...DID NOT CHANGE THIS PORTION OF THE FORECAST TOO MUCH DUE TO ALL THE UNCERTAINTY. HOWEVER...DO EXPECT WARMER TEMPERATURES ON SATURDAY AND EARLY ON SUNDAY WITH HIGHS IN THE UPPER 50S TO UPPER 60S...WARMEST ACROSS THE EASTERN PLAINS. OUTSIDE OF SOME AFTERNOON SHOWERS OR AN ISOLATED TSTORM...IT SHOULD MAINLY BE DRY ACROSS MOST OF THE FORECAST AREA THIS WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1115 PM MDT MON APR 6 2015 LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR STRATUS MOVING INTO THE PANHANDLE AND INTO THE EXTREME EAST SOUTHEAST WYOMING WILL PERSIST THROUGH THE OVERNIGHT HOURS. COULD BE A FAIRLY PROLONGED EVENT. POSSIBLY LASTING IN THE PANHANDLE INTO THE EARLY AFTERNOON HOURS. && .FIRE WEATHER... ISSUED AT 255 PM MDT MON APR 6 2015 RED FLAG CONDITIONS WILL PERSIST IN FIRE WEATHER ZONES 302 AND 306 THROUGH THE SUNSET. MEANWHILE...THERE COULD BE A WINDOW FOR MORE RED FLAG CONDITIONS TOMORROW IN 306 AGAIN FOR LOW HUMIDITIES AND GUSTY WINDS. HOWEVER...IT LOOKS TO BE RATHER MARGINAL AT THIS TIME ESPECIALLY WITH CLOUD COVER INCREASING. 302 MAY ALSO SEE THE POTENTIAL FOR DRY LIGHTNING...BUT WE WILL HOLD OFF ON REISSUING ANY RED FLAG WARNING FOR THOSE AREAS AND LET THE EVENING/MIDNIGHT SHIFTS TAKE A CLOSER LOOK. THURSDAY AND FRIDAY WE WILL SEE A BREAK IN THE RED FLAG CONDITIONS BEFORE NEXT TROF MOVES INTO THE PICTURE THIS WEEKEND. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...REC LONG TERM...TJT AVIATION...GCC FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
401 AM CDT THU APR 9 2015 .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SCATTERED THUNDERSTORMS THRU MID MORNING. * STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING. * IFR/LIFR THRU MID MORNING. * EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY SOUTHWEST THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE. SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE REGARDING TIMING. IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WATERS UNTIL 10 AM THURSDAY. GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 303 AM CDT Thu Apr 9 2015 .SHORT TERM...(Today) ISSUED AT 303 AM CDT THU APR 9 2015 Latest surface analysis shows the warm front has lifted to the I-74 corridor early this morning with a chaotic wind field across most of the forecast area. Not sure what the affect the current scattered convection will have on the position of the frontal boundary thru the morning hours, but most of the models suggest a continued slow push to the north as the main surface low tracks northeast to central Iowa by late this morning. Current thinking is that the cold front will be positioned just west of the Mississippi River by 21z with surface based convection developing ahead of the front at that time as well. Better low level helicity fields supportive of discrete supercells and possible tornadoes looks to be closer to the track of the surface low...which by late afternoon is expected to be in far southwest Wisconsin or northwest Illinois. That would put the threat for more persistent low level rotating storms just to our west and north. However, still plenty of shear ahead of the frontal boundary this afternoon and early this evening to promote damaging straight line winds as the storms transition into more of a linear system. Temperature-wise, with the warm front to our north this afternoon, will continue to go with the warmer guid values most areas. Latest model data now suggests the backedge of the precip pushes out of our far southeast counties by midnight, so will extend the Flash Flood Watch until that time this evening. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 303 AM CDT THU APR 9 2015 Showers and thunderstorms, possibly severe, will be ongoing across at least the eastern half of the forecast area to start this evening. Despite the short forecast range, there is still some spread in the expected cold frontal timing. However, it appears reasonable that the front will lie somewhere between the Illinois River and the I-55 corridor by 00Z Friday. Sped up the decrease in shower/storm chances by mid evening, and I would not be surprised to see the precipitation chances taper off a few hours earlier, especially if the squall line gets a head of steam and trends further ahead of the front than current progs. Once the front clears the area tonight, quiet conditions, along with much cooler and less humid air will build across the region into Sunday. These conditions will be driven by a large area of high pressure of Canadian origin. While conditions will be notably cooler/less humid, they will still be at or above normal for early April. The next precipitation chances will arrive later Sunday into Sunday night as a cold front is dragged across the area. While this front is still expected to stall out at it begins to parallel the upper-level flow, model trends suggest the front will stall out further south than previously anticipated. If these trends persist, Monday and Monday night will end up dry. For now, have reduced but not eliminated PoPs Monday/Monday night until we see if this recent model trend sticks. A slow moving upper-level disturbance will push the front back into the area by Tuesday, bringing renewed shower/storm chances. The front and/or upper level disturbances will keep the rain chances going into the end of the work week. Temperatures should remain at or above normal through the period. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) ISSUED AT 1123 PM CDT WED APR 8 2015 A broken line of showers and storms are progressing from SW to NE across our forecast area. Steady rains will clip CMI over the first hour of this TAF period, otherwise the other terminals could see a few hours of dry conditions before showers and storms re- develop directly over central IL. Elevated instability and moisture appear sufficient for a continued storm threat through the night. Localized IFR conditions could develop in any heavy rains, but mainly expect VFR conditions to drop to MVFR periodically overnight due to areas of low clouds as well as precip. The latest HRRR continues to indicate an expansion of coverage of showers and storms across our area tonight, which may linger past sunrise tomorrow before a break develops late morning through mid afternoon. Timing of any storms at the terminal sites is difficult, but will keep at least VCTS during the expected windows of opportunity. Wind patterns have been variable around storms, with prevailing direction from the SE. DEC gusted to 41 MPH at 04z/11pm due to storms. Ambient airflows have seen E-SE winds of 10-15kt, and that should continue the rest of the night based on the position of the frontal boundary. Once the storms depart to the east tomorrow morning, winds will shift to the southwest, and increase to 15-20kt sustained, with gusts to 30kt by afternoon. The next round of strong to severe storms is projected for Thursday afternoon and evening, with damaging winds, hail and even a few tornadoes possible across central IL. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH through this evening FOR ILZ054>057-061>063- 066>068-071>073. && $$ SHORT TERM...Smith LONG TERM...Bak AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT THU APR 9 2015 .UPDATE... IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE ADVISORY IN PLACE. IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID- LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SCATTERED THUNDERSTORMS THRU MID MORNING. * STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING. * IFR/LIFR THRU MID MORNING. * EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY SOUTHWEST THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE. SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE REGARDING TIMING. IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WATERS UNTIL 10 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 AM EDT THU APR 9 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 400 PM EDT WED APR 8 2015 BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER 2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM. BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL DEPICTIONS OF WEAK CVA FORCING. OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR SOUTHEAST COUNTIES. && .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED APR 8 2015 PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY NIGHT. ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON. AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY. AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER. MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON. 0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY. THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE 00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1 KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING. TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE. AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS TO BUILD INTO THE AREA. A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING THE CWA FRIDAY INTO FRI NIGHT. ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME. AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME FRAME...MAINLY IN THE 60S AND LOW 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 143 AM EDT THU APR 9 2015 STORMS HAVE BLOWN UP ACROSS NORTHERN ILLINOIS AND NORTHERN INDIANA AS MOISTURE ADVECTION CONTINUES OVER THE STATIONARY FRONT SETTLED ACROSS THE AREA. FIRST ROUND OF STORMS HAS LIFTED NORTH OF BOTH TERMINALS...BUT ANTICIPATE ADDITIONAL STORM DEVELOPMENT OVERNIGHT AS THE LOW LEVEL JET STRENGTHENS AND ELEVATED INSTABILITY CONTINUES TO ADVECT INTO THE AREA. SOUTHERLY WINDS WILL STRENGTHEN THROUGH THE DAY AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. ADDITIONAL STORMS EXPECTED AFTER 00Z TOMORROW...BUT WILL WAIT TO INCLUDE A MENTION UNTIL LATER TAF ISSUANCES WHEN FINER SCALE DETAILS BECOME MORE APPARENT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...AGD LONG TERM...MCD AVIATION...BENTLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1133 PM MDT WED APR 8 2015 .UPDATE... ISSUED AT 922 PM MDT WED APR 8 2015 ISSUED A LARGE UPDATE TO AMEND SKY...WEATHER AND POP GRIDS FOR THIS EVENING THROUGH TOMORROW EVENING. FOG/STRATUS HAS PUSHED FARTHER SOUTH THAN MOST GUIDANCE ONCE AGAIN. HRRR AND RUC HAVE LOCKED ONTO STRATUS WHILE OTHER GUIDANCE PERSISTS WITH A POOR FORECAST. ALSO...INCREASED POPS TO ACCOUNT FOR SHOWERS...STORMS AND DRIZZLE TONIGHT AND SHOWERS/DRIZZLE TOMORROW. THE FOG/DRIZZLE SETUP IS ESSENTIALLY IDENTICAL TO THE PREVIOUS TWO NIGHTS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 153 PM MDT WED APR 8 2015 AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL MOVE IN BEHIND THE TROUGH THURSDAY. PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY. DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING. DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP THOSE IN THE FORECAST. BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT. VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING. EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO THE LOWER 50S TO MID 50S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 107 PM MDT WED APR 8 2015 SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT. TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL. SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO 2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL. CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY. NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH TEMPERATURES ABOVE TO MUCH ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1133 PM MDT WED APR 8 2015 LOW CONFIDENCE FORECAST THIS RUN AS GUIDANCE CONTINUES STRUGGLE WITH FOG/DRIZZLE/STRATUS PLACEMENT. MOST ALL GUIDANCE KEEPS STRATUS TOO FAR NORTH BUT INITIAL FRONT HAS RETROGRADED FARTHER SOUTH THAN ANTICIPATED ONCE AGAIN. WENT WITH A PESSIMISTIC FORECAST SIMILAR TO ONGOING OBSERVATIONS AND WHAT OCCURRED PAST TWO NIGHTS. VARIABLE CIGS/VIS LIKELY LATER THIS MORNING AS A STRONGER COLD FRONT PASSES THROUGH...INCREASING ATMOSPHERIC MIXING. OVERALL...EXPECTING AN IMPROVING TREND FROM LATE MORNING INTO THE AFTERNOON. NORTH WINDS BACK NORTHEAST BY MORNING AND INCREASE SIGNIFICANTLY IN SPEED BEHIND THE STRONGER COLD FRONT. ANTICIPATE GUSTY WINDS THROUGHOUT THE LATE MORNING/AFTERNOON TODAY. WINDS RELAX UNDER VFR CIGS/VIS BEFORE SUNSET. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
156 AM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1208 AM EDT THU APR 9 2015 A FEW AREAS ACROSS THE REGION HAVE CLEARED OUT WITH CLOUD COVER AND WHERE THIS HAS OCCURRED...DENSE FOG IS BEGINNING TO DEVELOP. FOR NOW HAVE PUT THE MENTION OF FOG INTO THE ZONES AND THE HWO. A FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE FORECAST AREA...ESPECIALLY IN THE SOUTH...WHERE INSTABILITY IS RELATIVELY UNTOUCHED. THIS ACTIVITY MAY CONTINUE INTO THE MORNING HOURS. IN THE NORTH...DECIDED TO KEEP THE FLOOD WATCH GOING AS A FEW SHOWERS CONTINUE TO MOVE THE AREA AND ACTIVITY OUT WEST MAY MAKE IT INTO THE AREA LATER TONIGHT. HAVE UPDATED THE GRIDS AND SENT THEM TO THE NDFD SERVERS AND HAVE ISSUED SOME FRESH ZONES. UPDATE ISSUED AT 750 PM EDT WED APR 8 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER 05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 455 PM EDT WED APR 8 2015 THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN THE SMALL SCALE FEATURES AT PLAY. IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z. HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES. THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 521 PM EDT WED APR 8 2015 A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY. AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS LONG RANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 155 AM EDT THU APR 9 2015 AFTER A ROUND OF SHOWERS AND THUNDERSTORMS MOVED THROUGH PORTIONS OF EASTERN KY THIS EVENING...CLEARING IS FINALLY STARTING TO TAKE PLACE. THERE IS SOME CONCERN TONIGHT ABOUT FOG DEVELOPMENT. GUIDANCE IS SHOWING NO FOG POTENTIAL. HOWEVER...WITH CLEARING SKIES AND SUCH A MOIST ENVIRONMENT...THE POTENTIAL IS DEFINITELY THERE...ESPECIALLY IN THE VALLEYS. IT/S JUST A MATTER OF IF THIS FOG WILL SET IN AT THE TAF SITES...AND IF IT DOES...FOR HOW LONG AND TO WHAT RESTRICTION. KEPT WITH IFR VIS AFTER 9Z...BUT WILL CONTINUE TO MONITOR FOG DEVELOPMENT IN CASE CHANGES NEED TO BE MADE. BY TOMORROW...OUR NEXT ROUND OF INSTABILITY WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION...ESPECIALLY DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE WIDESRPEAD CHANCES VERY LATE IN THE PERIOD...AFFECTING KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044- 050>052-104. && $$ UPDATE...SHALLENBERGER SHORT TERM...JVM/GREIF LONG TERM...HAL AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1247 AM EDT Thu Apr 9 2015 ...Updated Aviation Discussion... ...Mesoscale Forecast Update... Issued at 830 PM EDT Wed Apr 8 2015 Strong to marginally severe convection across southern Indiana and much of central Kentucky is now pushing into the Bluegrass region. One renegade supercell near Owensboro weakened rapidly as it pushed eastward within the last hour, suggesting that our environment has been worked over, and observed temperatures are now in the upper 60s across most of the area. Warmer temps in south central Kentucky, but the environment is capped and the dynamical forcing aloft is also lacking. Will cut back on POPs as these storms exit the Bluegrass over the next hour or so, and work on canceling the Tornado Watch. The Flash Flood Watch is in effect and will be left in place, even though the flood threat won`t ramp up again until we get the next round of convection in sometime Thursday. .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (06Z TAF Update)... Updated at 1245 AM EDT Thu Apr 9 2015 Plan on VFR conditions the remainder of the overnight as air mass across central Kentucky has been worked over by earlier convection and is largely stable. A complex of showers/storms currently across Illinois may try to dip southeastward toward SDF/LEX by 11-13z. Confidence isn`t high as meso-models are showing this could end up staying to the north. Will keep mention in the TAFs for now. Increasing pressure gradient ahead of the next system will result in strong southerly winds later today at all sites. Plan on sustained winds 15-20 kts with gusts 25 to locally 30 kts. Timing the new few waves of convection is tricky but it looks like a pre-frontal system could spark a round of thunderstorms late this afternoon through early evening (22-03z) then a brief break before the main cold front passes 06-09z Friday. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late tonight FOR KYZ023>025-028>043- 045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late tonight FOR INZ076>079-083-084- 089>092. && $$ Mesoscale.........RAS Short Term........EER Long Term.........BJS Aviation..........ZT
AREA FORECAST DISCUSSION
NWS JACKSON KY
1208 AM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1208 AM EDT THU APR 9 2015 A FEW AREAS ACROSS THE REGION HAVE CLEARED OUT WITH CLOUD COVER AND WHERE THIS HAS OCCURRED...DENSE FOG IS BEGINNING TO DEVELOP. FOR NOW HAVE PUT THE MENTION OF FOG INTO THE ZONES AND THE HWO. A FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE FORECAST AREA...ESPECIALLY IN THE SOUTH...WHERE INSTABILITY IS RELATIVELY UNTOUCHED. THIS ACTIVITY MAY CONTINUE INTO THE MORNING HOURS. IN THE NORTH...DECIDED TO KEEP THE FLOOD WATCH GOING AS A FEW SHOWERS CONTINUE TO MOVE THE AREA AND ACTIVITY OUT WEST MAY MAKE IT INTO THE AREA LATER TONIGHT. HAVE UPDATED THE GRIDS AND SENT THEM TO THE NDFD SERVERS AND HAVE ISSUED SOME FRESH ZONES. UPDATE ISSUED AT 750 PM EDT WED APR 8 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER 05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 455 PM EDT WED APR 8 2015 THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN THE SMALL SCALE FEATURES AT PLAY. IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z. HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES. THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 521 PM EDT WED APR 8 2015 A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY. AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS LONG RANGE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 750 PM EDT WED APR 8 2015 AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH NORTHERN KENTUCKY THIS EVENING. EXPECT A FEW INSTANCES OF MVFR CONDITIONS...MAINLY IN AND AROUND THE HEAVY THUNDERSTORMS. THIS ACTIVITY WILL MOVE OFF TOP THE EAST BY 05Z AND SKIES WILL BEGIN TO CLEAR A BIT AS CLOUD COVER ASSOCIATED WITH THE ACTIVITY DISSIPATES. WITH THIS...MAY SEE A FEW AREAS OF FOG LATE TONIGHT AND HAVE PUT THIS INTO THE TAF SITES. CONDITIONS SHOULD BEGIN TO IMPROVE AFTER DAWN BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS DEVELOP LATE THURSDAY AFTERNOON. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044- 050>052-104. && $$ UPDATE...SHALLENBERGER SHORT TERM...JVM/GREIF LONG TERM...HAL AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
423 AM EDT THU APR 9 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN TODAY...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THIS AFTERNOON INTO TONIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS FEATURES COLD FRONT IN PLACE SOUTH OF THE LOCAL AREA THIS MORNING. CONTINUE TO NOTE SOME VERY LIGHT RAIN/DZ AND FOG ACROSS FAR NORTHERN ZONES, WITH MORE WIDESPREAD AREA OF SHOWERS AND EMBEDDED TSTMS CURRENTLY PUSHING SLOWLY TO THE E-SE FROM THE PIEDMONT INTO CENTRAL VA FOLLOWING WEAK STEERING FLOW JUST NORTH OF THE FRONTAL ZONE. HAVE CONTINUED TO NOTE ELEVATED INSTABILITY IN THIS AREA ATOP A STABLE/SATURATED BL. THE HRRR HAS HANDLED THIS (AND PREVIOUS) ROUND OF CONVECTION QUITE WELL AND HAVE HEDGED THE FORECAST IN ITS DIRECTION FOR THE FIRST PART OF THE NEAR TERM. WILL TAKE CURRENT SWATH OF CONVECTION ACROSS CENTRAL ZONES THROUGH 08-09Z...BEFORE IT TRANSITIONS ACROSS SE VA AND OFFSHORE BY 15Z. WITH PW VALUES WELL ABOVE CLIMO AVG (~2SD), SOME BRIEF HEAVY DOWNPOURS REMAIN POSSIBLE THIS MORNING. OTHERWISE, AS WITH YESTERDAY, GIVEN STABLE BL AND LITTLE IF ANY TANGIBLE IMMINENT FORCING MECHANISM UPSTREAM, WILL GO WITH A RELATIVE LULL IN PCPN AND A MAINLY DRY ALBEIT MAINLY OVERCAST AFTERNOON. GIVEN MOIST AIRMASS, WILL STICK WITH A SLIGHT CHC OF SHRAS FOR THE AFTN. LOOK FOR HIGHS IN THE MID TO UPPER 50S ACROSS THE NORTH, LOW TO MID 60S CENTRAL ZONES, AND U60S TO MID 70S ALONG AND SOUTH OF US 58 CORRIDOR OF SOUTHERN VA/INTERIOR NE NC. LOW PRESSURE OVER THE PLAINS WILL TRACK NE INTO THE UPPER MIDWEST LATE TODAY INTO EARLY FRIDAY. RESULTANT DEVELOPING WEAK RIDGING ALLOWS SW FLOW TO DEVELOP, WHICH WILL SHUNT WEAK FRONTAL ZONE BACK NORTH BY LATE IN THE DAY. WHILE MOST OF THE AREA WILL REMAIN IN THE STABLE/EASTERLY FLOW TODAY, EXPECT MILDER TEMPERATURES BY AFTN ACROSS SOUTHERN TIER OF THE CWA AS FRONT BEGINS TO LIFT BACK NORTH LATE TDA/TNGT. CONTINUED MILD ACROSS THE SOUTH TONIGHT, WITH LOWS IN THE U50S TO L60S SOUTH, LOW TO MID 50S NORTH. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THE AFOREMENTIONED UPPER TROUGH AND ATTENDANT SURFACE LOW OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY, SHUNTING SFC COLD FRONT IN OUR DIRECTION FRIDAY INTO FRIDAY NIGHT. LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES ~+2SD AND INCREASING LLVL STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE WILL LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND EVENING ACROSS THE REGION. SHOULD BE NOTED THAT THE HIGHER END OF INSTABILITY PROFILES ABOVE 2K J/KG HAVE BEEN DISCOUNTED FOR NOW GIVEN PREFRONTAL CLOUDS AND UNCERTAINTY OF SHRA COVERAGE EARLY FRI MORNING. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH FRI EVENING AS THE FRONT PUSHES ACROSS THE AREA. PREVIOUS FORECAST DEPICTING CHC POPS RAMPING INTO LIKELY RANGE DURING THIS PERIOD HAS BEEN RETAINED, WITH RAIN CHCS DROPPING OFF QUICKLY FROM NORTHWEST TO SOUTHEAST FRIDAY NIGHT. QUITE WARM ON FRIDAY WITH A FULL DAY OF COMPRESSIONAL HEATING ON WARM SOUTHERLY FLOW. LOOK FOR HIGHS IN THE MID 80S ALONG THE COASTAL PLAIN, UPPER 70S TO AROUND 80 INLAND. COLD FRONT SLIDES OFFSHORE TO BEGIN THE DAY SAT. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT START TO THE WEEKEND WITH HIGHS IN THE U60S NORTH TO LOW 70S SOUTH UNDER A MOSTLY SUNNY SKY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA... ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND INTERACTS WITH THE WARM FRONT. BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES. RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER OF THE WEEKEND. && .MARINE... THUNDERSTORMS WILL CROSS THE WATERS THIS MORNING AND THEN COME TO AN END ACROSS SRN COASTAL WATERS BY MID TO LATE MORNING. OTHERWISE...A FRONT THAT CROSSED THE WATERS ON WED WILL REMAIN STALLED ACROSS THE CAROLINAS TODAY. PERSISTENT N-NE WINDS AOB 15KT HAVE KEPT SEAS ELEVATED BTWN 4-7FT FROM FENWICK ISLAND TO THE VA/NC BORDER. SEAS WILL SLOWLY SUBSIDE BELOW 5FT FOR COASTAL WATERS SOUTH OF PARRAMORE ISLAND BY THIS AFTN...AND REMAIN AROUND 5FT CLOSER TO 20NM FOR NRN COASTAL WATERS TODAY THROUGH MOST OF FRIDAY BEFORE FALLING BELOW 5FT/SCA THRESHOLDS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT TONIGHT INTO EARLY FRI MORNING. WINDS TONIGHT WILL BEGIN E-SE AOB 15KT AND THEN BECOME MORE SLY BEHIND THE WARM FRONT (15-20KT COASTAL WATERS...AOB 15KT BAY/RIVERS/SOUND). SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL AVERAGE 15-20KT WITH GUSTS OF 25- 30KT DURING THE AFTN. SEAS WILL AVERAGE 3-4FT TONIGHT INTO FRI MORNING AND THEN BUILD TWD 5FT FROM PARRAMORE ISLAND TO CAPE CHARLES LIGHT BY MID-LATE FRI MORNING. WAVES 2-3FT TONIGHT WILL THEN AVERAGE 3FT ON FRI. THE COLD FRONT CROSSES THE WATERS FRI NIGHT WITH STRONG THUNDERSTORMS EXPECTED. MAIN IMPACTS WILL BE GUSTY AND ERRATIC THUNDERSTORM WINDS WITH HEAVY RAINFALL. MARINERS SHOULD BE AWARE OF RAPIDLY CHANGING CONDITIONS AND PLAN FOR A QUICK ROUTE TO SAFE HARBOR WHEN NEEDED LATE FRI AFTN/EVENING. BEHIND THE COLD FRONT FRI NIGHT...A COOLER AIRMASS DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF THE COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT W-N WINDS ON SAT AOB 15KT...DECREASING TO AOB 10KT SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...BMD MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
208 AM EDT THU APR 9 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN OVERNIGHT...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THURSDAY INTO THURSDAY NIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WHAT`S LEFT OF A DECAYING OH VLY MCS WAS MOVING THROUGH NE NC AS OF 10 PM. THIS BATCH OF SHOWERS AND SUB-SEVERE THUNDERSTORMS WILL MOVE OUT OF THE AREA BETWEEN MIDNIGHT-1AM. OTW...A BACKDOOR COLD FRONT SITS JUST SOUTH OF THE FA AND SHOULD REMAIN STATIONARY OVERNIGHT. THIS WILL ALLOW LOW OVERCAST CONDITIONS TO CONTINUE OVERNIGHT WITH SFC HIGH PRESSURE RIDGING DOWN INTO THE LOCAL AREA FROM THE NORTHEAST. THE NEXT BATCH OF PCPN IS MAKING ITS WAY THROUGH THE OH VLY LATE THIS EVENING AND IS SHOWN BY THE LATEST HRRR TO MAKE A RUN AT THE FA BY AROUND 08-09Z...THEN MOVING SE THRU 15Z. THE HRRR DID A GOOD JOB HANDLING THE MCS THIS EVENING SO WILL LEAN TOWARD ITS SOLUTION OVERNIGHT AND HAVE ADJUSTED POPS ACCORDINGLY. LOWS TONIGHT FROM NR 40 MD EASTERN SHORE TO THE LOW/MID 50S SW. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/... THE FRONT WILL WEAKEN...WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY LATE THU. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO M70S WITH MORE TIME IN THE WARM SECTOR ACROSS SRN/WRN AREAS. POPS REMAIN IN THE CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN PERIODS FOR SCT SHRAS...AND ISOLTD TSTMS ESPECIALLY OVER SRN/WRN AREAS. THE SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS...HAIL AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY COMPARED TO PREVIOUS DAYS AS THE ENTIRE FA RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS SE AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA... ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND INTERACTS WITH THE WARM FRONT. BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES. RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER OF THE WEEKEND. && .MARINE... UPDATE...COASTAL WATERS FROM CAPE CHARLES LIGHT TO THE VA/NC BORDER ADDED TO SCA FLAGS THROUGH 700 AM THIS MORNING DUE TO SEAS OF 4-5 FT. BACKDOOR COLD FRONT HAS LOCATED JUST SOUTH AND WEST OF THE WATER THIS AFTERNOON. THE RESULT IS N-NE FLOW...AVG 10-15 KT. STRONGER GRADIENT EXISTS OVER THE NRN COASTAL WATERS...WHERE A FEW GUSTS 25- 28 KT OBSERVED. SEAS HAVE BUILT TO 6-8 FT OVER THE NRN COASTAL ZONES...GENERALLY NORTH OF PARRAMORE ISLAND. FARTHER SOUTH...SEAS AVG 2-4 FT. SCA HEADLINES REMAIN IN EFFECT NORTH OF CAPE CHARLES LIGHT FOR SEAS. GRADIENT WINDS EXPECTED TO DIMINISH TONIGHT AOB 15 KT...BUT SEAS WILL REMAIN ELEVATED (4-7 FT) AS NE FLOW PERSISTS. BACKDOOR FRONT REMAINS JUST SOUTH AND WEST OF THE WATER THURS...SLOWLY LIFTING BACK NWD. FLOW BECOMES MORE ONSHORE...E-NE GENERALLY 10-15 KT. SEAS REMAIN 4-6 FT NORTH OF PARRAMORE ISLAND...DROPPING BELOW 5 FT SOUTH. BACKDOOR FRONT LIFTS NORTH OF THE WATER FINALLY THURS NIGHT-FRI MORNING AS A WARM FRONT. FLOW BECOMES SLY...INCREASING TO AROUND 15 KT RIVERS/BAY/SOUND AND 20 KT COASTAL WATERS. MARGINAL SCA CONDITIONS ARE POSSIBLE FRI AFTERNOON AS THE GRADIENT STRENGTHENS IN ADVANCE OF AN APPROACHING COLD FRONT. WILL HOLD OFF ON HEADLINES DUE TO 4TH PERIOD AND BEING MARGINAL ATTM. COLD FRONT CROSSES THE WATERS FRI NIGHT...WITH FLOW BECOMING NWLY POST FRONTAL. BEST CAA REMAINS NORTH OF THE LOCAL AREA...BUT A FEW GUSTS TO 20 KT POSSIBLE IN THE BAY AND 25 KT COASTAL WATERS BRIEFLY LATE FRI NIGHT-EARLY SAT MORNING. SEAS BUILD TO 4-6 FT FRI NIGHT. HIGH PRESSURE BUILDS OVER THE WATERS THIS WEEKEND...RESULTING IN SUB-SCA CONDITIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAS NEAR TERM...JDM/MAS SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...BMD MARINE...BMD/SAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 409 AM EDT THU APR 9 2015 MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON IMPACT OF EXITING LO PRES ON FRI/TRAILING SHRTWV AND NEXT CHC FOR RA SUN INTO MON. WHILE FRI WL STILL BE CHILLY IN THE STRONG NW FLOW LEFT IN THE WAKE OF THE DEPARTING LO... EXPECT TEMPS TO RISE ABOVE NORMAL AS A MORE ZONAL PACIFIC FLOW DOMINATES STARTING ON SAT. FRI...AS MAIN NEGATIVELY TILTED SRN BRANCH SHRTWV WITH ACCOMPANYING 990MB OR SO SFC LO JUST E OF THE SAULT AT 12Z FRI LIFT TO THE NE... LARGER SCALE DEEP LYR QVECTOR CNVGC WL EXIT AS WELL IN THE MRNG. THE 00Z GFS IS A BIT SLOWER WITH THIS PROCESS DUE TO A FARTHER W TRACK OF THE SHRTWV/SFC LO...MAINTAINING MORE SGNFT PCPN AND DEEP LYR QVECTOR CNGVC A BIT LONGER. SINCE THE MODELS DO NOT SHOW A QUICK PHASING OF THIS SRN BRANCH SHRTWV AND A NRN BRANCH DISTURBANCE MOVING INTO NRN MN ON FRI MNRG...TENDED AWAY FM THIS SLOWER... DEEPER SCENARIO. LATEST NCEP DISCUSSION SUPPORTS THE DECISION TO RELY MORE HEAVILY ON THE 00Z NAM. BUT THE NAM HAS SLOWED DOWN THE EXIT OF THE SHARPER DYNAMIC FORCING...SO COORDINATED WITH SHORT TERM FCSTR TO EXTEND WINTER WX HEADLINES THRU FRI MRNG FOR THE N HALF OF THE HEADLINE AREA. WHILE THE DEPARTURE OF THE SRN BRANCH DYNAMIC FORCING WL BRING A DIMINISHING TREND TO THE ACCOMPANYING PCPN BY LATE MRNG...MODELS ARE IN GOOD AGREEMENT SHOWING THE NRN BRANCH SHRTWV ACCOMPANIED BY SOME FAIRLY SHARP DPVA/DEEP LYR QVECTOR CNVGC DIGGING INTO THE UPR LKS AND MAINTAINING A SHARP CYC NW FLOW. H925 ARE WINDS FCST AS HI AS 35-45KTS UNDER THE H85 THERMAL TROF TRAILING THE DEPARTING LO. WHILE THE PASSAGE OF THE NRN BRANCH DISTURBANCE LATER IN THE DAY AND ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC WL RESULT IN A WEAKENING OF THE CYC FLOW OVER THE W DURING THE AFTN...SUSPECT SN WL BE RATHER PERSISTENT OVER THE E HALF OF THE CWA. IN FACT...THE 00Z NAM SHOWS ARND 0.35 INCH OF PCPN FALLING AS SN AT ERY...AND MANY OF THE HIER RES MODELS SHOW SIMILAR QPF. SO BUMPED UP POPS OVER ESPECIALLY THE NE HALF OF THE CWA. EVEN THOUGH THE PRES RISE CENTER BEHIND THE DEPARTING LO WL PASS TO THE S OF UPR MI AND ELIMINATE AN ISALLOBARIC WIND COMPONENT...FRI WL BE QUITE WINDY ESPECIALLY OVER THE E...WHERE WIND GUSTS NEAR LK SUP MAY AT LEAST APRCH ADVY CRITERIA. WITH THE NW FLOW OFF MORE EXTENSIVE ICE COVER ACROSS THE E HALF OF THE LK AND MORE PERSISTENT PCPN THERE...LOWERED FCST HI TEMPS OVER THE ERN CWA. FRI NGT...AFTER THE NRN BRANCH SHRTWV DIGS INTO THE CENTRAL GREAT LKS ON FRI EVNG...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC WL OVERSPREAD THE ERN CWA...ENDING LINGERING PCPN THERE. STEADY H5 HGT RISES THAT ARE FCST TO APRCH 100M BTWN 00Z-12Z SAT IN ADVANCE OF TRAILING SHRTWV/SFC RDG AXIS WL BRING CLRG SKIES AS THE LLVL FLOW BECOMES MORE ACYC. RATHER STEADY NW BACKING W FLOW TO THE NE OF HI CENTER MOVING FAIRLY FAR TO THE SW AND INTO THE MID MS RIVER VALLEY WL TEND TO LIMIT THE DIURNAL TEMP DROP...BUT TEMPS SHOULD STILL FALL INTO THE TEENS OVER SOME SN ACROSS THE INTERIOR W HALF...WHICH WL BE CLOSER TO THE WEAKER PRES GRADIENT AND SEE THE EARLIER INFLUX OF PWAT AOB 0.25 INCH. SAT...AS SFC RDG AXIS EXTENDING N OF SFC HI CENTER CROSSING THE LOWER LKS/OH RIVER VALLEY PASSES OVER THE UPR LKS...EXPECT A MOSUNNY DAY. AS LARGER SCALE SUBSIDENCE/WAA IN THE SW FLOW ON THE BACK SIDE OF THE RDG LIFT H85 TEMPS UP TO 4C OVER THE W BY 00Z SUN...EXPECT TEMPS TO REBOUND INTO THE 50S AWAY FM LK MODERATION THAT WL IMPACT MAINLY THE ERN CWA. READINGS MAY EVEN APRCH 60 IN THE DOWNSLOPE AREAS OVER THE W. SAT NGT...AS THE SFC HI PRES SHIFTS TO THE E...WAA/ISENTROPIC ASCENT WL BRING INCRSG MID CLDS. SOME OF THE MODELS EVEN GENERATE SOME LGT RA SHOWERS AT THE NOSE OF H85 SW LLJ UP TO 45-50 KTS UNDER TIGHTENING PRES GRADIENT WITH THE APRCH OF SHRTWV DOWNSTREAM OF A DEEPENING TROF FARTHER W IN THE NRN PLAINS. INITIAL MSTR RETURN DOES NOT APPEAR TO BE THAT SGFNT...SO WL GO WITH JUST LO CHC POPS FOR NOW OVER THE NW HALF OF THE CWA. COMBINATION OF STEADY SW WIND AND INCRSG CLDS WL LIMIT THE DIURNAL TEMP FALL...ESPECIALLY IN THE DOWNSLOPE AREAS OVER THE W. SUN/SUN NGT...AS FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS IN ADVANCE OF UPR TROF MOVING E FM THE NRN PLAINS OVERSPREAD UPR MI AND THE STRONG SW FLOW TAPS MORE COPIOUS MSTR THAT LIFT PWAT CLOSE TO 1 INCH BY 00Z MON...EXPECT MORE NMRS SHOWERS TO OVERSPREAD UPR MI ON SUN AFTN. BUT THIS PCPN WL THEN END W-E SUN NGT AS ACCOMPANYING PACIFIC TYPE COLD FNT CROSSES THE UPR LKS AND BRINGS AN INFLUX OF DRIER AIR IN ADVANCE OF SFC HI PRES. SUSPECT THE RUNOFF FM THE RA AS WELL AS THE RATHER QUICK SN MELT ACCOMPANYING THE FAIRLY DRAMATIC WARMUP MAY CAUSE AREA RIVERS TO RISE FAIRLY QUICKLY. EXTENDED...INCOMING HI PRES/DRY AIRMASS WL BRING A MOSUNNY DAY FOR MON. SINCE THE AIRMASS WL A MARITIME POLAR PACIFIC ONE...MAX TEMPS SHOULD RISE INTO THE 50S AWAY FM LK MODERATION. THEN AN APRCHG WARM FNT ASSOCIATED WITH A DISTURBANCE LIFTING NE INTO THE PLAINS WL BRING A RETURN FOR RA CHANCES NEXT TUE/WED. TEMPS WL BE ABOVE NORMAL WITH PACIFIC AIRMASS IN PLACE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 126 AM EDT THU APR 9 2015 DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN CHANGING OVER TO SNOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT THU APR 9 2015 AS A DEEPENING LO PRES MOVES FROM THE PLAINS THRU THE CENTRAL GREAT LAKES TONIGHT AND INTO SE CANADA ON FRI...EXPECT ENE WINDS UP TO 20 KTS TO BACK TO THE NNW...AND INCREASE UP 35-45 KT GALES OVER MUCH OF THE E HALF OF THE LAKE BY LATE TONIGHT. OPTED TO ISSUE GALE WARNINGS FOR THE E HALF. THESE GALE FORCE NNW WINDS WILL THEN DIMINISH ON FRI AFTERNOON INTO EARLY EVENING AS THE LO PRES EXITS FARTHER TO THE NE AND THE PRES GRADIENT WEAKENS IN ADVANCE OF AN APPROACHING HI PRES RIDGE. LIGHTER WINDS ON SAT WILL THEN BACK TO THE SW FOLLOWING THE PASSAGE OF THE RIDGE AXIS TO THE E. AS A COLD FRONT APPROACHES ON SUN...EXPECT SSW WINDS TO INCREASE UP TO 20-25 KTS. AFTER THE FRONT PASSES ON SUN NIGHT...WINDS WILL SHIFT TO THE W AND DIMINISH QUICKLY WITH THE APPROACH OF ANOTHER HI PRES ON MON. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR MIZ002-009-010. WINTER STORM WARNING FROM 10 PM THIS EVENING TO NOON EDT FRIDAY FOR MIZ001-003-004-084. WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR MIZ005. LAKE SUPERIOR... GALE WARNING FROM 8 AM TO 8 PM EDT FRIDAY FOR LSZ251-267. GALE WARNING FROM 5 AM TO 5 PM EDT FRIDAY FOR LSZ249-250-266. GALE WARNING FROM 5 AM TO 2 PM EDT FRIDAY FOR LSZ244-245-248-264- 265. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...07 MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 AM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 456 PM EDT WED APR 8 2015 COMPLEX FORECAST FRONT LOADED IN FIRST PERIOD OF LONG TERM. HIGH IMPACT WEATHER EXPECTED IN FORM OF RAIN CHANGING TO HEAVY SNOW. MAIN FACTORS COMING INTO FOCUS FOR THURSDAY NIGHT WEATHER. FIRST ALOFT...UPPER TROUGH OVER THE INTERIOR WESTERN CONUS THIS MORNING MOVES TO UPPER MISSISSIPPI RIVER VALLEY BY THURSDAY EVENING WHILE SHORTWAVE TROUGH DIGGING OVER NORTHERN SASKATCHEWAN THIS AFTN MOVES TO AXIS FM NORTHERN ONTARIO TO SOUTHERN MANITOBA. MAIN JET STREAK LIFTS OVER NORTHERN ONTARIO INTO QUEBEC ON THURSDAY EVENING WHILE ANOTHER JET WILL BE IN PROCESS OF EXITING TOWARD GREAT LAKES. AS THE PLAINS JET ARRIVES OVER THE GREAT LAKES THURSDAY EVENING...LEAD SHORTWAVE TROUGH IS FORECAST TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS OVER THE UPPER GREAT LAKES. FOR MOST PART...LEAD WAVE DRIVES STRENGTH AND TRACK OF H85-H7 TROUGH AND PRIMARY SFC LOW...WHICH TRACKS FM IOWA AT 00Z FRIDAY TO NORTHERN LK MICHIGAN/NORTHERN LOWER MICHIGAN BY 06Z FRIDAY AND TO EAST OF SAULT STE MARIE BY 12Z FRIDAY. MODELS CONTINUE TO DIFFER ON WESTWARD EXTENT OF SFC LOW WHICH AFFECTS WHERE SWATH OF HEAVY QPF WELL OVER 1 INCH OCCURS ROUGHLY 00Z- 09Z ON FRIDAY. GIVEN VERY STRONG LIFT FM COUPLED JET STRUCTURE AND ENHANCED DIVERGENCE ALOFT AND PERSISTENT STRONG MID-LEVEL FGEN ALONG WITH COPIOUS DEEP MOISTURE THAT SHOULD BE ABLE TO TRANSLATE INTO THE DEEPENING SYSTEM AS MAIN INFLOW FOR TSRA SHOULD STAY FAR ENOUGH SOUTHEAST OF UPR MICHIGAN...TEND TO BELIEVE WETTER IDEAS OFFERED UP BY NAM/GFS SHOWING WELL OVER 1 INCH OF QPF. THOUGH ECMWF REMAINS DRIER...IT HAS SHOWN NOTEABLE TREND TOWARD STRONGER SYSTEM THE LAST DAY...SO THAT IS ENCOURAGING AT LEAST FROM THE FORECAST STANDPOINT. RUNNING WITH THE STRONGER/WETTER IDEA...MAIN STICKING POINT IS HOW QUICK THE RAIN CHANGES TO SNOW ON THURSDAY NIGHT. THE EARLIER THAT SWITCHOVER OCCURS...THE MORE THAT HEAVY QPF WILL GO TOWARD WET HEAVY SNOW ACCUMULATION. NAM SOUNDINGS SHOW WARM LAYER BTWN 900MB-800MB VCNTY OF L`ANSE TO WATERSMEET AT 00Z...THEN TO CRYSTAL FALLS AND MARQUETTE/HARVEY BY 03Z...BEFORE PUSHING THIS ON THE MUNISING AND ESCANABA BY 06Z. GFS AND GEM-REGIONAL ARE FARTHER WEST WITH WARM LAYER ALOFT...THOUGH THEY BOTH TRENDED A BIT EAST WITH TRACK OF SFC LOW ON THE 12Z RUNS. EXPECT HEAVY WET SNOW TO IMPACT PARTS OF WESTERN HALF OF UPR MICHIGAN. RETREATING WARM LAYER TO START COULD ALSO RESULT IN SLEET OF FZRA BEFORE CHANGE TO SNOW OCCURS. DECIDED TO ISSUE A WINTER STORM WATCH FOR WESTERN UPR MICHIGAN AS THERE SHOULD BE A NARROW STRIPE OF POSSIBLE VERY HEAVY WET SNOW THURSDAY NIGHT. GIVEN THE FORCING AND MOISTURE...LOCALIZED AMOUNTS OVER 8 INCHES SEEM POSSIBLE. MAIN QUANDARY WAS HOW FAR WEST AND EAST TO PUSH THE WATCH. LEANED A BIT TOWARD THE FARTHER EAST WARM LAYER IDEA WHICH RESULTED IN BRINGING THE WATCH AS FAR EAST AS MARQUETTE COUNTY. GIVEN DECENT CHANCE THAT PRECIP STAYS MAINLY RAIN WELL INTO THE EVENING FOR DICKINSON COUNTY LEFT THEM OUT FOR NOW...THOUGH COULD SEE NEED FOR ADVY FOR EVENTUALLY SLOPPY INCH OR TWO OF SNOW. CORRIDER OF HEAVY SNOW LIKELY WILL NOT MAKE IT AS FAR WEST AS IWD THOUGH LATEST HPC/WWD GRAPHICS STILL HIT FAR WEST FOR DECENT AMOUNT OF SNOW...BUT SINCE EASTERN PORTIONS OF GOGEBIC COUNTY INTO ONTONAGON COUNTY WOULD BE IMPACTED BY THE HEAVY SNOW WITH LATEST THINKING...INCLUDED GOGEBIC AS WELL. ESSENTIALLY SINCE THIS EVENT COULD BE VERY HIGH IMPACT DECIDED TO GO THIS ROUTE INSTEAD OF HAVING AN SPS OUT ONLY. WILL TRY TO CONVEY THE UNCERTAINTY DUE TO BOTH LOCATION OF HEAVIER SNOW AND PTYPE IN THE WSW STATEMENT. COORD WITH DLH AND GRB ON SNOW AMOUNTS/HEADLINE TIMING. LOW PRESSURE EXITS OVER EASTERN CANADA FRIDAY INTO FRIDAY NIGHT. LINGERING LOW-LEVEL MOISTURE/THERMAL TROUGHING AND ADDITIONAL FORCING FM THE NORTHERN STREAM WAVE DROPPING OVER THE AREA SUPPORTS CHANCE POPS FOR SNOW ON FRIDAY THOUGH MOST OF THE BIGGER SNOW WILL BE DONE BY DAYBREAK FRIDAY. KEPT WITH TEMPS MAINLY IN THE 30S ON FRIDAY. BREEZY CONDITIONS TOO...ESPECIALLY NEAR LK SUPERIOR IN THE MORNING HOURS. SFC RIDGE CROSSES FRIDAY NIGHT AND TEMPS COULD DIP INTO THE TEENS. EXPECT THIS TO BE THE LAST NIGHT THROUGH THE LONG TERM WHERE TEMPS DROP BLO FREEZING. TEMPS THIS WEEKEND LOOKS WARMER...MUCH WARMER. HIGH CLOUDS INCREASE LATE SATURDAY AND SATURDAY NIGHT AHEAD OF LOW PRESSURE TROUGH THAT MOVES FM SCNTRL CANADA TO NORTHERN PLAINS ON SUNDAY. MIXING HEIGHTS UP TO H85 WITH SW WINDS SUPPORT READINGS WELL INTO THE 50S. COOLEST TEMPS OVER EAST CWA WITH FLOW COMING OFF LK MICHIGAN. SOME LGT RAIN MAY DEVELOP AHEAD OF THE TROUGH ON SUNDAY AS GFS/ECMWF HAVE BEEN SHOWING FOR A WHILE NOW. EVEN SO...WARMER TEMPS ALOFT AND WARMER MIN TEMPS ON SATURDAY NIGHT ALLOW MANY AREAS TO REACH 60 DEGREES. SO ANY SNOW THAT DOES OCCUR THURSDAY NIGHT INTO FRIDAY SHOULD QUICKLY MELT THIS WEEKEND. FURTHER...ONCE THE TEMPS RISE ABOVE FREEZING ON SATURDAY THEY SHOULD REMAIN ABOVE FREEZING THROUGH MUCH OF NEXT WEEK SO WE SHOULD ALSO BEGIN TO MELT GOOD PORTION OF THE SNOWPACK THAT REMAINS OVER MAINLY NORTHERN UPPER MICHIGAN. SHOULD SEE AREA RIVERS AND STREAMS BEGIN TO RESPOND WITH THE SNOWMELT AND RUNOFF. ADDITIONAL RAINFALL POSSIBLE TUESDAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM AND WARM FRONT MOVE TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES. ANY RAINFALL FM THIS SYSTEM WOULD ONLY ADD TO THE RUNOFF. SEEMS THAT AFTER THIS WINTRY SYSTEM WE MIGHT JUST SHIFT INTO THE MAIN SNOWMELT HYDROLOGY PERIOD OF THE SPRING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 126 AM EDT THU APR 9 2015 DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN CHANGING OVER TO SNOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 456 PM EDT WED APR 8 2015 HIGH PRES MOVING E ACROSS QUEBEC AND LOW PRES DEVELOPING OVER THE CNTRL/SRN PLAINS WILL KEEP LAKE SUPERIOR UNDER GENERAL E TO NE WINDS OF 10-20KT THRU EARLY THU AFTN. AS THE LOW PRES TRACKS NE ACROSS NORTHERN LAKE MI THU EVENING AND INTO ONTARIO FRI MORNING...WINDS WILL BACK TO THE NW. OVER THE CNTRL PART OF LAKE SUPERIOR...THE WIND WILL ALSO INCREASE TO 20-30KT...AND OVER ERN LAKE SUPERIOR N TO NW GALES WILL DEVELOP BY FRI MORNING. WINDS WILL THEN DIMINISH W TO E FRI AFTN THRU FRI NIGHT AS HIGH PRES BUILDS ACROSS THE MISSISSIPPI VALLEY. LIGHT WINDS UNDER 20KT ARE EXPECTED SAT AS THE HIGH PRES RIDGE PASSES ACROSS THE WRN GREAT LAKES. AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E ACROSS THE NRN PLAINS...WINDS WILL THEN INCREASE SAT NIGHT/SUN...PROBABLY REACHING 15-25KT OR MORE OVER AT LEAST THE E HALF OF LAKE SUPERIOR ON SUN. THE TROF WILL CROSS THE UPPER GREAT LAKES SUN NIGHT...BRINGING A WIND SHIFT TO THE W. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR MIZ001>005-009-010-084. LAKE SUPERIOR... GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR LSZ266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
328 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN ALL LIQUID. THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN. HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS AND HAVE REMOVED. TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED. ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS WITH DIURNAL HEATING. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE. RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE 30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL SIDE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CDT THU APR 9 2015 A SURFACE LOW WAS LOCATED IN THE WESTERN KS/EASTERN CO REGION LATE THIS EVENING AND IS FORECAST TO LIFT INTO IOWA THURSDAY MORNING. WAA AHEAD OF THIS LOW WILL AID IN DEVELOPING PRECIP ACROSS THE NORTHLAND TONIGHT THROUGH THURSDAY NIGHT. SHOWERS WERE ALREADY MOVING ACROSS NORTHERN WISCONSIN AND WE EXPECT COVERAGE TO INCREASE OVERNIGHT. A WINTRY MIX WILL OCCUR OVER FAR NORTHERN WISCONSIN INTO PORTIONS OF NORTHEAST MINNESOTA...WITH MAINLY RAIN AT KHYR UNTIL LATE THURSDAY AFTERNOON. MVFR/IFR CONDITIONS WILL PREVAIL THROUGH THURSDAY MORNING...THEN SOME CLEARING WILL OCCUR OVER WESTERN TAF SITES...AND GRADUALLY MOVE EAST TO KHIB/KDLH. ANOTHER POTENT SHORTWAVE WILL MOVE SOUTH THURSDAY NIGHT AND BRING SOME SNOW SHOWERS WITH IT. WE ADDED A VCSH AT KINL LATE IN THE PERIOD. FOG WILL BE POSSIBLE AROUND LAKE SUPERIOR...ESPECIALLY AT KDLH. WE EXPECTED LOWER VSBYS TO OCCUR BY NOW BUT HAVE YET TO SEE THAT. WE WILL DELAY THE LOWER VSBYS UNTIL LATE TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 32 48 30 / 70 20 20 10 INL 50 30 48 28 / 10 40 10 0 BRD 49 31 51 29 / 60 20 20 10 HYR 42 31 47 27 / 90 80 30 10 ASX 38 31 45 29 / 100 70 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT THU APR 9 2015 TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN THE SANDHILLS. THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE NORTHWEST AT THE SAME TIME. THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER 40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH. HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES FOR LOWS IN THE UPPER 20S TO LOWER 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM CDT THU APR 9 2015 RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS. WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA. BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT SPREAD EAST ONTO THE PLAINS. TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD COOL TEMPERATURES BACK BELOW NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1153 PM CDT WED APR 8 2015 IFR CEILINGS ARE FORECAST UNTIL 16Z AT KLBF AND KVTN. A STORM SYSTEM WILL TRACK EAST ACROSS WESTERN NEBRASKA OVERNIGHT AND THURSDAY BRINGING RA TO KLBF. COLDER AIR MOVING IN TO BRING A MIX OF RASN OR A POSSIBLE CHANGEOVER TO SN TO KVTN FROM 10Z-15Z. WINDS 34015G25KT WILL OCCUR AFTER 12Z WITH CEILINGS IMPROVING TO MVFR BY 16Z AND THEN VFR BY 20Z FOR BOTH TERMINALS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1133 PM CDT WED APR 8 2015 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT WED APR 8 2015 PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT AND ALSO SHOWERS ON THURSDAY. SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM 12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO. GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA. OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE COULD ALSO BE SOME LOCALLY HEAVY RAIN. SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY. PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT... MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT. WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 315 PM CDT WED APR 8 2015 WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1129 PM CDT WED APR 8 2015 IFR TO LIFR CONDITIONS WILL CONTINUE AS A VERY MOIST LOW LEVEL LAYER REMAINS OVER THE REGION. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO SPREAD OVER THE TAF SITES THROUGH THE MORNING HOURS. DID NOT INCLUDE A MENTION OF THUNDER...BUT WILL CONTINUE TO MONITOR TRENDS AND AMEND AS NECESSARY. WINDS WILL TURN TO THE NORTHWEST AS A COLD FRONT DROPS ACROSS THE AREA ON THURSDAY. GUSTS UP TO 35KTS ARE POSSIBLE LATE THURSDAY MORNING INTO THURSDAY AFTERNOON. SKIES AND VISIBILITIES MAY BEGIN TO SCATTER OUT QUICKLY AROUND SUNSET...PERHAPS BECOMING CLEAR BY THE END OF THE TAF CYCLE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...KERN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
351 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 350 AM THURSDAY... SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES. HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT. MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY... WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S. THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON... WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...RAH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 320 PM WEDNESDAY... MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE MID 50S TO LOWER 60S. TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO WITH LOWS IN THE MID 40S. THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...22 AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 300 PM WEDNESDAY... TO BE UPDATED SHORTLY. && LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 320 PM WEDNESDAY... MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE MID 50S TO LOWER 60S. TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO WITH LOWS IN THE MID 40S. THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM... LONG TERM...22 AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
355 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 LIFR CIGS/VSBYS WILL CONTINUE AT KDIK THROUGH 14Z BEFORE IMPROVING BACK TO VFR BY 16Z-17Z. ELSEWHERE...MVFR CIGS AND VSBYS POSSIBLE AT KBIS/KJMS THROUGH 14Z. MVFR VSBYS ALSO POSSIBLE AT KISN/KMOT AS SURROUNDING SITES SUCH AS WATFORD CITY AND TIOGA REPORTING VISIBILITIES BETWEEN 2SM AND 6SM. ALL TERMINALS ARE EXPECTED TO RETURN TOWARD VFR STATUS BY 15Z-17Z TODAY. EXPECT A FAIRLY LARGE BUT SHALLOW CUMULUS FORMATION ACROSS WESTERN AND CENTRAL NORTH DAKOTA 18Z THURSDAY THROUGH 00Z FRIDAY. THE CUMULUS WILL DISSIPATE QUICKLY AROUND SUNSET WITH A CLEAR SKY TO FOLLOW THROUGH 12Z FRIDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM...TWH AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 AM EDT THU APR 9 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... 830 PM UPDATE... EXPANDED FFA FARTHER N TO ACCOUNT FOR WHERE COMPLEX IS COMING IN FROM THE W...AND WENT ACROSS THE NRN TIER TO ACCOUNT FOR CONVECTION ALONG THE 300K ISENTROPIC SFC GRADIENT H8-H85 THERE. 745 PM UPDATE... UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC GRADIENT H8-H85 ACROSS THE NRN TIER. 630 PM UPDATE... UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE. PREV DISCN... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR RESTRICTIONS. SOME MVFR FOG IS POSSIBLE EARLY THIS MORNING IN AREAS RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY VFR CLOUDS CAN BE EXPECTED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. UNCERTAIN ON POST-RAIN FOG FORMATION EARLY THIS MORNING. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 04/09/15 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY M M H H H H H M H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS LATE THURSDAY NIGHT AND INTO FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR WVZ005>011- 013>017-019-020-024>026-031. OH...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR OHZ066-067- 075-076-083>087. KY...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/SL NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...SL AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 AM EDT THU APR 9 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS. REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE. RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS. SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/... MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE. THERE HAVE BEEN SLIGHT BREAKS IN SOME OF THE MVFR TO IFR CIGS AND VSBYS...THOUGH THESE WILL BE THE EXCEPTION AND NOT THE RULE. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH WITH MAY TAF SITES GOING CALM OVERNIGHT. AS THURSDAY CONTINUES THE LOW STRATOCU WILL SLOWLY BREAK UP...WITH IFR CIGS INCREASING TO MVFR TO PERHAPS A BRIEF PERIOD OF VFR...BEFORE DROPPING DOWN THURSDAY EVENING. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...FITZGERALD/LAMBERT SHORT TERM...FITZGERALD/LA CORTE/LAMBERT LONG TERM...MARTIN AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
136 AM EDT THU APR 9 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS. REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE. RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS. SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/... MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /05Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT/FITZGERALD LONG TERM...MARTIN AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
112 AM EDT THU APR 9 2015 .SYNOPSIS... M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION THIS WEEKEND. && .NEAR TERM /THROUGH TODAY/... 0515 UTC UPDATE...SKY COVER WAS ADJUSTED PER SATELLITE IMAGERY. POPS WERE ADJUSTED PER RADAR TRENDS. WINDS WERE UPDATED FROM THE LATEST MODEL DATA. TEMPERATURES WERE ADJUSTED UP A BIT TODAY AND DOWN A BIT TONIGHT PER THE LATEST MODEL DATA. AS OF 1000 PM...THE LATEST SPC MESOANALYSIS PAGE STILL SHOWS 1000-2000 J/KG OF MUCAPE. A COUPLE OF ISOLD TSTMS HAVE POPPED UP IN THE MIDLANDS...AND THE LAST COUPLE OF HRRR RUNS DO SHOW A FEW MORE CELLS DEVELOPING OVER THE NEXT FEW HOURS SOUTH OF I-85. SO WILL ADD A SLGT CHC BACK IN ACRS THE SOUTHEASTERN ZONES. CANNOT RULE OUT A SEVERE PULSE STORM GIVEN THE CAPE AND 25-30 KTS OF EFFECTIVE SHEAR. OTHERWISE...THE REST OF THE FCST LOOKS ON TRACK. AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN. TEMPS/SKY/WINDS ARE ON TRACK. AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY PRECIP...IF THE LATEST TRENDS HOLD. AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA. SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH LARGE HAIL AND DAMAGING WINDS. UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN 1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES CLOSER TO ANY SHORTWAVE ACTIVITY. TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT... WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL IN FAIRLY GOOD AGREEMENT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT. WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND 850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION... ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE. ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL. && .AVIATION /05Z THURSDAY THROUGH MONDAY/... AT KCLT...MODEL TIME HEIGHTS SUGGEST LOW VFR CLOUDS WILL BE PRESENT FOR MUCH OF THE FORECAST PERIOD...WITH THE CURRENT CIG ERODING AFTER DAYBREAK. A LOW VFR CIG WOULD RETURN TONIGHT AHEAD OF AN ADVANCING COLD FRONT. GUIDANCE HAS BACKED OFF ON A DAYBREAK VSBY RESTRICTIONS...AND WITH A LACK OF RAINFALL YESTERDAY THIS SCENARIO HAS BEEN ACCEPTED. INSTABILITY WILL BE PRESENT AGAIN TODAY...SUPPORTING THUNDERSTORMS THAT MAY LINGER INTO THE EVENING AHEAD OF THE APPROACHING COLD FRONT. ANY RESTRICTIONS WOULD BE ASSOCIATED WITH PRECIPITATION. WINDS WILL FAVOR THE S AND SW. ELSEWHERE...VSBY RESTRICTIONS ARE NOT SUPPORTED AT TAF SITES BY A MODEL CONSENSUS...AND WITH NO RAIN YESTERDAY...THIS OUTCOME HAS BEEN ACCEPTED. MODEL TIME HEIGHTS SHOW LOW VFR CLOUDS PERSISTING... ALTHOUGH SATELLITE IMAGERY SHOWS SOME AREAS WHERE HIGH CIRRUS IS THE PREVAILING CLOUD. LOW VFR CIGS ARE NOT EXPECTED UNTIL THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. INSTABILITY WILL SUPPORT THUNDERSTORMS TODAY AND TONIGHT AS THE FRONT ADVANCES...WITH ASSOCIATED RESTRICTIONS POSSIBLE. WINDS WILL FAVOR THE S AND SW. OUTLOOK...A COLD FRONT WILL PUSH THROUGH FRIDAY...BRINGING WITH IT THE POTENTIAL FOR CONVECTION. CONDITIONS IMPROVE FOR THE WEEKEND AFTER THE FRONT CLEARS THE AREA. MOISTURE RETURNS LATE MONDAY. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...ARK/JAT/TDP SHORT TERM...PM LONG TERM...RWH AVIATION...JAT
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
400 AM CDT THU APR 9 2015 .DISCUSSION... A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE. AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME OF THIS ACTIVITY THROUGH DAYBREAK. THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z. WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO 2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM HELICITY VALUES APPROACHING 200 M2/S2. EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH 30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE. THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS. 58 && .AVIATION... /ISSUED 1149 PM CDT WED APR 8 2015/ /06Z TAFS/ SOME MVFR CIGS ARE ALREADY LOCATED AROUND THE AREA BUT MVFR CIGS ARE EXPECTED TO SPREAD OVER ALL THE TAF SITES BY 09-10Z. GUSTY WINDS ARE OCCURRING DUE TO DISSIPATING RAIN AND STORMS IN THE AREA AND THE WINDS OVERNIGHT ARE EXPECTED TO PREVAIL 15-20 KTS WITH GUSTS UP TO 30 KTS. SOME ADDITIONAL THUNDERSTORMS ARE STILL POSSIBLE OVERNIGHT AND WILL MAINTAIN A VCTS MENTION IN THE METROPLEX BETWEEN 09-12Z. CIGS WILL IMPROVE ABOVE 2 KFT BY MIDDAY THURSDAY AND THEN INTO VFR CATEGORY BY MID-LATE AFTERNOON. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AS A COLD FRONT MOVES ACROSS THE AREA. THUNDERSTORMS WILL BE POSSIBLE IN THE METROPLEX AHEAD OF THE FRONT FROM 09/21-10/02Z AND AT KACT BETWEEN 10/03-07Z. THESE STORMS COULD BE STRONG OR SEVERE WITH A LARGE HAIL AND/OR DAMAGING WIND THREAT. THE WINDS WILL SHIFT TO THE NORTH THURSDAY EVENING AS THE FRONT MOVES THROUGH. JLDUNN && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40 WACO, TX 84 58 73 58 76 / 30 60 20 30 40 PARIS, TX 79 51 73 52 73 / 40 70 10 30 40 DENTON, TX 83 53 73 54 73 / 40 30 10 30 40 MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40 DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40 TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40 CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40 TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40 MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/58
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1248 AM CDT THU APR 9 2015 .AVIATION... A CLUSTER OF SHRA IS MOVING EAST ACROSS THE HILL COUNTRY AND ESCARPMENT AREAS. HAVE GONE WITH VCSH AT KAUS/KSAT/KSSF OVERNIGHT AS THIS CLUSTER CONTINUES TO THE EAST. MVFR CIGS HAVE DEVELOPED FROM THE COASTAL PLAINS TO THE I-35 CORRIDOR. THESE CIGS WILL SPREAD WEST ACROSS THE HILL COUNTRY TO THE RIO GRANDE PLAINS AND KDRT OVERNIGHT WITH A BRIEF PERIOD OF IFR CIGS EARLY THURSDAY MORNING. HOWEVER...THERE IS A POSSIBILITY THAT THE CLUSTER OF SHRA DISRUPTS THE MVFR CIGS. A DRYLINE WILL MOVE INTO THE EDWARDS PLATEAU AND PARTS OF THE RIO GRANDE PLAINS MID MORNING INTO AFTERNOON AND THEN RETREATS BACK WEST THURSDAY NIGHT. SKIES WILL BECOME VFR BY LATE MORNING AT KDRT. EAST OF THE DRYLINE...CIGS WILL RISE TO VFR IN THE AFTERNOON. THERE IS SOME POSSIBILITY OF SHRA/TSRA ALONG AND EAST OF THE DRYLINE. WILL LEAVE MENTION OF THESE OUT OF THE TAFS DUE TO UNCERTAINTY ON LOCATION. MVFR CIGS REDEVELOP FROM THE COASTAL PLAINS ACROSS THE I-35 CORRIDOR INTO THE HILL COUNTRY THURSDAY NIGHT. A COLD FRONT SAGS SOUTH THROUGH CENTRAL TEXAS LATE TONIGHT AND EXPECT SOME SHRA/TSRA ALONG IT AND HAVE MENTIONED VCSH AT KAUS. S TO SE WINDS 7 TO 15 KTS PREVAIL. EXCEPT...W TO NW 4 TO 8 KTS BEHIND THE DRYLINE AND NE BEHIND THE COLD FRONT. && .PREV DISCUSSION... /ISSUED 936 PM CDT WED APR 8 2015/ UPDATE... /RAISED POPS...THUNDER CHANCES WRN THIRD/ FAST PACED CONVECTIVE CLUSTER ARRIVING FROM WEST TX IS A SOUTHWARD EXTENT OF A BROKEN LINE OF CONVECTION THAT EXTENDS NORTH INTO NW TX. THE SOUTHERN ENHANCEMENTS ARE LIKELY THE PRODUCT OF FAVORABLE JET DYNAMICS AND STEEPENING MID LEVEL LAPSE RATES. MOST OF THE HI-RES RUNS SHOWN THE ACTIVITY WEAKENING BEFORE REACHING THE I-35 CORRIDOR...BUT DO SHOW SOME AREAS OF LIGHT QPF FROM LIGHT SHOWERS. WILL EXTEND A MENTION OF SPRINKLES INTO SOUTHEAST COUNTIES AND BEEF UP POPS OVER MAINLY VAL VERDE COUNTY AND TO A SMALLER EXTENT THE RIO GRANDE PLAINS. OTHERWISE...THE FORECAST REMAINS ON TRACK. PREV DISCUSSION... /ISSUED 703 PM CDT WED APR 8 2015/ AVIATION... THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON THURSDAY. PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A FREDERICKSBURG TO LA GRANGE LINE. FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB. WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS MOSTLY DRY. FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/ LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY AND POCKETS OF HEAVY RAIN OVER THE WEEKEND. FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND SOUTHERN ZONES. FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS. FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50 AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50 NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50 BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50 DEL RIO INTL AIRPORT 68 89 69 83 67 / 50 - 20 50 50 GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50 HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50 SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50 LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50 SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50 STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...04 SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1152 PM CDT Wed Apr 8 2015 .AVIATION... /06Z TAFS/ Showers and thunderstorms are quickly moving out of the area with no additional activity to our west, so have removed all mention of precipitation from TAFs. As models were showing earlier, low clouds are not materializing, or are rapidly disappearing as they did around KSJT, so have removed any mention of low clouds as well. Expect this trend to hold up through the overnight hours as we are nearing the trough axis at this point, with dry air moving into the air aloft indicated by WV satellite imagery. VWP loops show increasingly westerly component to low level winds, so overall drying is expected to continue. Gusty southerly winds will continue through the rest of the overnight hours. West to southwest winds move in tomorrow morning. A cold front will drop south into the KABI area by around 00Z tomorrow evening, then KSJT and KBBD around or shortly after 03Z, but may have a hard time making the I-10 corridor before 06Z tomorrow night. && .PREV DISCUSSION... /ISSUED 942 PM CDT Wed Apr 8 2015/ DISCUSSION... Forecast has been updated to remove Severe Thunderstorm Watch 38 from all but Haskell County. Haskell County will be removed after this line of thunderstorms move through. Expecting wind gusts in the 40 mph range, but will allow the storms to move through before cancelling the watch. Have also lowered PoPs across the area somewhat as the southern end of the line of thunderstorms continues to decay as it moves east. 20 PREV DISCUSSION... /ISSUED 736 PM CDT Wed Apr 8 2015/ DISCUSSION... Have updated forecast products for Severe Thunderstorm Watch 38 in effect for areas generally west of a Haskell/Abilene/Ballinger/ San Angelo line through 1 AM. Gusts over 60 mph and hail up to the size of quarters are possible with these storms. The line should start moving into Sterling/Irion Counties between 8 and 830 PM, and into the Nolan/Fisher County area between 830 and 9 PM. 20 PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/ AVIATION... /00Z TAFS/ Skies have cleared, except for a blanket of mid and upper level clouds across most of west central Texas. A weakly organized broken band of thunderstorms is moving toward the west central Texas area this evening. Have these storms moving across our TAF sites roughly between 01Z(8PM) and 06Z(1AM). These storms have brought gusts of over 40 knots to areas to our west. This is likely due to very dry low layers of the atmosphere, and fast movement of the storms themselves. Will carry a mention of gusty winds to 35 knots in TEMPO groups at area sites to account for the possibility of gusty winds. Based on most recent trends (gusts to 35-40 knots), do not expect these to bring severe strength wind gusts of 50 knots or great at this time, but this cannot be ruled out. For the rest of the overnight hours, models have become much less pessimistic with respect to low clouds after 03Z(10PM) tonight, so will go with higher, but still MVFR (2500 feet) CIGS at most sites tonight beginning around 06Z(1AM). Winds will remain south to southeasterly and gusty through most of the overnight. Winds will shift to the west tomorrow between 12Z(7AM) and 15Z(10AM). 20 PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/ SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 20 5 10 20 40 San Angelo 66 87 57 73 61 / 10 10 10 40 40 Junction 66 85 62 75 62 / 20 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
206 AM EDT THU APR 9 2015 .SYNOPSIS... A BACK DOOR COOL FRONT OVER NORTHEAST VIRGINIA WILL CONTINUE TO EASE SOUTHWEST ACROSS THE PIEDMONT OVERNIGHT. THE BOUNDARY WILL THEN LIFT BACK TO THE NORTH THURSDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FROM THE WEST. THIS FRONT WILL PUSH THROUGH FROM THE WEST FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 200 AM EDT THURSDAY... NEAR TERM UPDATES TO SHOW HIGHER POPS WITH SHOWERS AND THUNDERSTORMS LIKELY FARTHER EAST ALL THE WAY INTO PIEDMONT WITH THIS CURRENT WAVE OF CONVECTION. THUNDER MAY DIMINISH AS IT MOVES WELL OVER THE WEDGE ENTRENCHED OVER THE NORTHEAST PART OF THE AREA BUT NOT SURE IT WILL ENTIRELY SO LEFT THUNDER IN ALL THE WAY EAST THROUGH ABOUT 5 AM. LOWERED MINS IN NORTHEAST BASED ON CURRENT TEMPS OF UPPER 40S JUST TO THE NORTHEAST OF OUR AREA IN CENTRAL VA. PREV DISC AS OF 855 PM EDT WEDNESDAY... WEDNESDAY AFTERNOON CONVECTION HAS MOVED SOUTHEAST OUT OF THE FORECAST AREA. A WEAK HIGH PRESSURE CENTER WILL PROVIDE US WITH A SHORT BREAK IN THE ROUNDS OF CONVECTION THIS EVENING. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED IN OHIO AND KENTUCKY. THIS CONVECTION WILL CONTINUE TO MOVE EASTWARD AND ROTATE ACROSS OUR REGION TONIGHT INTO THURSDAY MORNING. THE TIMING OF THIS CONVECTION APPEARS A LITTLE FASTER THAN HIRES MODELS SUGGEST. THE BETTER INSTABILITY WILL OCCUR UNTIL AROUND 02Z...THEN THE INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH. LEANED THE POPS TOWARDS A HRRR AND RAP BLEND BECAUSE OF THE WARM ADVECTION SHOWERS NOTED ON WSR-88D IMAGES ACROSS WEST VIRGINIA. IN ADDITION TO THE SHOWERS AND THUNDERSTORMS...HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS EVENING INTO TONIGHT...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. RAINFALL FROM THIS EVENING AND TONIGHT STORMS WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND CREATE THE LOWER CLOUDS EXPECTED OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. INITIALLY SHAPED TEMPERATURES THIS EVENING INTO TONIGHT TOWARDS LAMP. THEN WITH THE RICH CLOUD COVER...OVERNIGHT TEMPERATURES WILL REMAIN MILD WITH READINGS FROM THE LOWER 50S IN THE MOUNTAINS TO THE UPPER 50S IN THE SOUTH. HIGHS ON THURSDAY WILL RANGE FROM THE UPPER 60S IN THE NORTH TO THE UPPER 70S IN THE SOUTH. AS OF 600 PM EDT TUESDAY... MADE SOME ADJUSTMENTS IN POPS AND WEATHER FOR THIS EVENING INTO TONIGHT...SHAPING TOWARDS WSR-88D RADAR TRENDS AND LATEST HRRR SOLUTION. ADJUSTED TEMPERATURES FOR THIS EVENING INTO TONIGHT. AS OF 415 PM EDT TUESDAY... KEEPING OUR EYES ON A SERIES OF DISTURBANCES STRETCHING FROM VIRGINIA TO THE MISSISSIPPI RIVER THIS AFTERNOON...ALL TRIGGERING THUNDERSTORM ACTIVITY AND ALL PROGGED TO RIDE A STATIONARY FRONT EASTWARD THROUGH THE EVENING AND OVERNIGHT. THE FIRST LINE OF THUNDERSTORMS IS WEAKENING AS IT ENCOUNTERS THE DOWNSLOPE FLOW IN THE VICINITY OF INTERSTATE 64. EXPECT LOCALLY GUSTY WINDS AND POCKETS OF HEAVY RAIN AS THE LINE CROSSES MOUNTAINS...BUT BELIEVE SEVERE THUNDERSTORM ACTIVITY WILL BE ISOLATED AT BEST...IF AT ALL. FURTHER WEST...THUNDERSTORM ACTIVITY DEVELOPING ACROSS CENTRAL KENTUCKY IS EXPECTED TO ENTER OUR MOUNTAIN EMPIRE COUNTIES AFTER SUNSET...AND CONVECTION DEVELOPING OVER SOUTHERN ILLINOIS IS EXPECTED TO APPROACH OUR WESTERN RIDGES BEFORE DAWN THURSDAY. INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH...SO BELIEVE THE THREAT FOR SEVERE STORMS THIS EVENING AND TONIGHT REMAINS REMOTE. IN ADDITION TO STORMS...HIGH PRESSURE CONTINUES TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS AFTERNOON...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. BELIEVE THAT RAINFALL ENTERING THE AREA THIS EVENING AND TONIGHT WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND HELP TO STRENGTHEN THE HIGH PRESSURE AS IT BUILDS IN...WHICH WILL MAKE FOR WIDESPREAD CLOUD COVER OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. CLOUDS WILL MAINTAIN MILD TEMPERATURES THROUGH THE NIGHT...HOLDING OVERNIGHT LOWS IN THE MID AND UPPER 50S. WILL STICK TO THE COOL SIDE OF GUIDANCE FOR HIGH TEMPERATURES ON THURSDAY...HOLDING HIGHS IN THE LOW AND MID 70S FOR MUCH OF THE AREA. BELIEVE THAT TEMPERATURES WILL REMAIN COOL THROUGH MID AFTERNOON DUE TO THE MORE WIDESPREAD NATURE OF THE CLOUD COVER...AND THEN SEE A LATE DAY UPWARD SPIKE IN TEMPERATURES AS CLOUDS BEGIN TO BREAK UP DURING MAX AFTERNOON HEATING. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... AS OF 400 PM EDT WEDNESDAY... STRONG SHORT WAVE OVER THE UPPER MID WEST WILL MOVE EAST THURSDAY NIGHT AND FRIDAY. THURSDAY NIGHT THE SURFACE LOW MOVES NORTHEAST ACROSS THE GREAT LAKES...THEN ON FRIDAY TRACKS INTO SOUTHERN ONTARIO. ANY REMNANTS OF THE SURFACE WEDGE AND MORE STABLE AIR MASS IN THE NORTHEAST COUNTY WARNING AREA WILL BE GONE ON THURSDAY EVENING. TIMING HAS BEEN CONSISTENT IN THE MODELS BRINGING THE ASSOCIATED COLD FRONT THROUGH A BULK OF THE COUNTY WARNING AREA ON FRIDAY. MODELS WERE FORECASTING BEST INSTABILITY AHEAD OF THE FRONT IN THE PIEDMONT ALONG THE EASTERN EDGE OF THE FORECAST AREA ON FRIDAY AFTERNOON...WITH CAPES OF AS HIGH AS 2000 J/KG POSSIBLE. WILL MAINTAIN MENTION OF SEVERE WEATHER THREAT IN THE HAZARDOUS WEATHER OUTLOOK. 12Z MODELS WERE VERY SIMILAR WITH THE TIMING OF THE FRONT ON FRIDAY. WILL MAKE SLIGHT ADJUSTMENTS TO THE LOCATION BETWEEN 18Z/2PM FRIDAY AND 00Z SATURDAY/8PM FRIDAY WITH A HIGHER PROBABILITY OF RAIN. MORE CHALLENGING TO TELL HOW MUCH COVERAGE OF SHOWERS AND THUNDERSTORMS THERE WILL BE AHEAD OF THE FRONT THURSDAY NIGHT. HAVE ALSO REMOVED THE RAIN BEHIND THE FRONT FOR LATE FRIDAY NIGHT AND SATURDAY. WILL BE TRENDING TOWARD WARMER GUIDANCE AHEAD OF THE FRONT FOR LOWS ON THURSDAY NIGHT. WILL BE STARTING MILD ON FRIDAY BUT LIMITED HEATING DURING THE MORNING OVER THE MOUNTAINS WHICH WILL HOLD TEMPERATURES IN THE 60S. IN THE EAST WHERE THE FRONT COMES THROUGH LATER...TEMPERATURES WILL RISE WELL INTO THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 200 PM EDT WEDNESDAY... SECOND PIECE OF ENERGY COMES THROUGH THE NORTHEASTERN TROF ON SATURDAY SO THE 500 MB LONG WAVE TROF DOES NOT MOVE EAST OF THE FORECAST AREA UNTIL SUNDAY MORNING. THEN PATTERN RETURNS TO RIDGING IN THE EAST AND TROFING THE WEST FOR THE REST OF THE PERIOD. HEIGHTS AT 500 MB BECOME MORE AMPLIFIED BY MONDAY AND TUESDAY. WITH A DEEP CLOSED LOW IN THE WEST MONDAY THROUGH WEDNESDAY...FORECAST AREA WILL BE IN BROAD SOUTHWEST FLOW WITH A SERIES OF SHORT WAVES TRACKING OUT OF THE SOUTHERN PLAINS. AT THE SURFACE A SECONDARY FRONT CROSSES THE NORTHEAST SATURDAY NIGHT BUT LOOKS FAIRLY WEAK BY THE TIME IT REACHES THE CENTRAL APPALACHIANS. WPC CONSIDERED NORTH AMERICAN AND GFS ENSEMBLES AS REASONABLE FOR THE UPPER AND SURFACE TIMING AND LOCATION OF FEATURES FOR THIS TIME FRAME. HIGH PRESSURE BUILDS IN FOLLOWING THE FRONT AND WILL BE CENTERED OVER THE FORECAST AREA ON SUNDAY MORNING. THE HIGH WILL BE OFFSHORE BY MONDAY AFTERNOON. WARM...MOIST AIR WILL BE IN PLACE ON TUESDAY AND WEDNESDAY. APPEARS THERE WILL BE NO ORGANIZED LIFTING MECHANISM TO GENERATE PRECIPITATION BUT ANY DECENT SHORT WAVE SHOULD BE ABLE TO TRIGGER AT LEAST AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AFTER TEMPERATURES DROP BEHIND THE FRONT ON FRIDAY...850 MB VALUES REBOUND MONDAY THROUGH WEDNESDAY. MODELS HOLD RESIDUAL LOW LEVEL MOISTURE IN THE WESTERN UPSLOPE AREAS THROUGH SATURDAY MORNING. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 205 AM EDT THURSDAY... DEALING WITH ANOTHER WAVE OF SHWRS AND THUNDERSTORMS MOVING THROUGH OVERNIGHT ACROSS THE NORTHERN HALF OF THE AREA...ALTHOUGH A FEW SHWRS MAY GET DOWN TO DANVILLE AFTER 08 UTC. WEDGE FRONT DOWN INTO NORTHERN NC AND INTO NEW RIVER VALLEY AREA AS WELL...WITH IFR CONDITIONS AT LYH...AND BEHIND THIS WAVE OF SHWRS AND STORMS SHOULD LOWER TO IFR AT ROA...BCB...AND EVENTUALLY DAN. MAY BE TOO AGGRESSIVE WITH THIS IN CURRENT TAFS BUT CONFIDENCE HIGH WE`LL SEE IFR BEFORE DAWN AT ALL THESE AIRPORTS. KEPT IT MVFR AT LWB AND BLF BUT LOWER CONF THERE. COULD REMAIN VFR AT BLF WITH OCCASSIONAL SHOWERS OR STRAY TSTORM OVERNIGHT. HIGH PRESSURE IS EXPECTED TO MAINTAIN ITS HOLD ON THURSDAY...WITH LOW CEILINGS LINGERING ACROSS MUCH OF THE AREA INTO MID AFTERNOON. WITH BETTER INSTABILITY ALONG THE CONTINENTAL DIVIDE WHERE HIGH PRESSURE HAS LESS INFLUENCE...MAY SEE A FEW SHOWERS AND ISOLATED THUNDERSTORMS DEVELOP BY LATE AFTERNOON IN MAXIMUM HEATING. EXTENDED AVIATION DISCUSSION... PROLONGED PERIOD OF MVFR CONDITIONS LOOKS IN ORDER INTO FRIDAY WITH A COLD FRONTAL PASSAGE EXPECTED LATER FRIDAY. COLD FRONT EXPECTED TO CLEAR THE REGION FRIDAY NIGHT-SATURDAY MORNING WITH ANY SHOWERS SUBSIDING...THOUGH SOME UPSLOPE MVFR CEILINGS MAY LINGER INTO SATURDAY AT KBLF/KLWB. WIDESPREAD VFR THEN RETURNS SATURDAY NIGHT AND SUNDAY UNDER HIGH PRESSURE BEHIND THE FRONT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF NEAR TERM...KK/NF/SK SHORT TERM...AMS LONG TERM...AMS AVIATION...KK/NF/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
336 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT THU APR 9 2015 SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF WISCONSIN INTO SOUTHERN MICHIGAN. FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY 12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW. NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF 1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME SOUTHERN MOST FORECAST AREA. FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE 09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2 INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN. HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 335 AM CDT THU APR 9 2015 AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT EXIST. SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES ACROSS THE AREA. NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES... THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON THIS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1100 PM CDT WED APR 8 2015 CIGS... NOT A LOT OF CHANGE EXPECTED THROUGH THU NIGHT WITH MOST CIGS HOVERING AROUND OR BELOW 1 KFT. VARIOUS BOUTS OF SHRA/TS WILL KEEP CIGS LOWS...AS WILL POOLED MOISTURE UNDER A STRONG LOW LEVEL INVERSION. WINDS... WINDS WILL GO FROM EAST TO NORTH NORTH/NORTHWEST THU AFTERNOON AS AN AREA OF LOW PRESSURE SLIDES JUST SOUTH OF THE TAF SITES. INCREASING PRESSURE GRADIENT ON THE NORTHWEST SIDE OF THE LOW SHOULD RESULT IN AN INCREASE IN SUSTAINED WINDS - ALONG WITH THE POTENTIAL FOR HIGHER GUSTS - THU NIGHT. WX/VSBY... BANDS OF SHOWERS WILL SWEEP ACROSS THE REGION TONIGHT INTO THU NIGHT. THERE WILL LIKELY BE SEVERAL HOUR BREAKS BETWEEN THEM...BUT TRYING TO FERRET OUT EXACT TIMING IS PROBLEMATIC...SO WON/T GET THAT REFINED IN THE FORECAST. FOR THUNDER CHANCES...BUFKIT SOUNDINGS SHOW MEAGER INSTABILITY A LOFT...AND INTERESTINGLY MOST OF IT IS ABOVE THE SATURATED LAYER. THAT SAID...A FEW STORMS HAVE DEVELOPED AND APPROACHED KRST/KLSE. HAD TO UPDATE PREVIOUS TAFS TO INCLUDE MENTION FOR A FEW HOURS PAST 06Z. RUC GRADUALLY SINKS THE ELEVATED INSTABILITY SOUTHWARD OVERNIGHT. COULD BE ISOLATED THUNDER THU INTO THU NIGHT...BUT CONFIDENCE TOO LOW TO INCLUDE IN FORECAST AT THIS TIME. ALSO OF NOTE IN THE BUFKIT SOUNDINGS IS THE SOMEWHAT SHALLOW NATURE OF A LOT OF THE SATURATION. IN MANY WAYS ITS MORE SUGGESTIVE OF A HEAVY DRIZZLE RATHER THAN SHRA/RA TYPE EVENT. HAVE NOTED DRIZZLE ALREADY THIS EVENING...BEFORE SHOWERS MOVED IN. THU AFTERNOON SEEMS TO FAVOR DRIZZLE TOO. VSBYS WILL BE RESTRICTED IN THE HEAVIER PCPN...ESPECIALLY IF HEAVY DRIZZLE MANIFESTS. SOME FOG SHOULD HELP LOWER VSBYS OVERNIGHT INTO THU MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
858 AM EDT THU APR 9 2015 .SYNOPSIS... A WEAK RIDGE OF HIGH PRESSURE ACROSS THE AREA WILL MOVE OFF TO THE EAST BY TONIGHT. LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES REGION AND CAUSE A WARM FRONT TO CROSS OUR AREA FRIDAY. A COLD FRONT WILL FOLLOW FOR FRIDAY NIGHT. MORE HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND AND REMAIN INTO MONDAY. ANOTHER LOW AND SERIES OF FRONTS WILL AFFECT THE WEATHER NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NOT TOO MANY CHANGES WITH THIS UPDATE. WE ADDED SOME PATCHY MORNING DRIZZLE MAINLY IN NJ BASED ON OBS AND RADAR RETURNS. WE USED LATEST HRRR AND RAP TRENDS TO LOWER POPS THROUGH THE MID DAY FOR THE REMNANT PCPN SOUTH AND OTHER PCPN TRYING TO ARRIVE FROM THE WEST. AGREE WITH MID SHIFT TEMPS ARE GOING NOWHERE TODAY. A FRONTAL BOUNDARY WAS LOCATED FROM THE WESTERN SIDE OF THE CENTRAL APPALACHIANS BACK DOWN INTO THE CAROLINAS EARLY THIS MORNING. MEANWHILE, HIGH PRESSURE LOCATED OVER EASTERN CANADA CONTINUES TO RIDGE SOUTHWARD INTO THE NORTHEAST AND MID-ATLANTIC STATES. WITH THIS CAD PATTERN ON THE EASTERN SIDE OF THE APPALACHIANS HOLDING STRONG, EXPECT TODAY TO BE PRETTY MUCH A REPEAT OF YESTERDAY: CLOUDY AND COOL BUT SLIGHTLY LESS WET AND WINDY. THE ONE CONCERN EARLY THIS MORNING IS SPOTTY FREEZING DRIZZLE AND FREEZING FOG AT HIGHER ELEVATIONS IN THE POCONOS. BASED ON LATEST MESONET OBSERVATIONS, TEMPS ARE MARGINALLY FREEZING (31-32F) ABOVE 1500 FT. ISSUED AN SPS FOR THESE AREAS TO COVER THE POSSIBILITY OF LIGHT ICING ON ELEVATED SURFACES. EXPECT LITTLE IMPACTS THOUGH WITH PAVEMENT TEMPERATURES REMAINING ABOVE FREEZING. REMNANTS FROM A DECAYING MCS THAT IS CURRENTLY OVER VA WILL MOVE EASTWARD EARLY THIS MORNING. THIS WILL BRING A PERIOD OF SHOWERS TO THE DELMARVA AND POSSIBLY AS FAR SOUTHERN NJ BETWEEN 4-9 AM. OTHERWISE, COVERAGE OF RAIN EXPECTED TO BE MINIMAL FOR THE REST OF THE DAY WITH ORGANIZED LIFT AND INSTABILITY STILL WELL TO OUR WEST. BASED ON VERIFICATION OF TEMPS YESTERDAY AND LAST NIGHT, FELT IT WAS PRUDENT TO GO COLDER THAN STAT GUIDANCE FOR TEMPS TODAY. WE FAVORED THE RAW OUTPUT FROM THE NCEP WRF ARW/NMM, WHICH GIVES US HIGHS IN THE 40S (15-20F BELOW NORMAL). && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... SOUTHWESTERLY FLOW WILL STRENGTHEN ALOFT AS LOW PRESSURE DEEPENS OVER THE GREAT LAKES. THIS WILL ADVECT WARMER AIR ALOFT INTO THE REGION BUT THE SHALLOW LAYER OF COLD AIR TRAPPED IN THE LOWEST 1000 FT OF THE ATMOSPHERE WILL PREVENT THE WARM FRONT FROM MAKING IT INTO OUR AREA. THEREFORE, CLOUDY, COOL AND DAMP CONDITIONS WILL PERSIST INTO TONIGHT. FORECAST SOUNDINGS APPEAR A BIT MORE FAVORABLE FOR DRIZZLE TONIGHT THAT IT DID LAST NIGHT WITH ISENTROPIC LIFT AND MOISTURE ADVECTION ABOVE THE CAD WEDGE. WE WILL NEED TO KEEP AN EYE OUT ON POTENTIAL MCS DEVELOPMENT UPSTREAM THIS AFTERNOON OVER THE MIDWEST. THE REMNANTS OF THIS SYSTEM COULD BRING A ROUND OR TWO OF SHOWERS TO OUR REGION TONIGHT. THE WARM NOSE AROUND 900 MB STRENGTHENS LATE AND THE 00Z NAM BUFKIT SOUNDINGS FORECASTS SEVERAL HUNDRED J/KG OF ELEVATED INSTABILITY TO DEVELOP OVER OUR AREA TOWARD EARLY MORNING. OPTED TO NOT PUT IN ANY MENTION OF THUNDER AS THERE IS A LITTLE BIT OF CIN FOR PARCELS TO OVERCOME, WHICH MAY INHIBIT CONVECTION GIVEN A LACK OF SIGNIFICANT LIFT. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... FRIDAY/FRI NIGHT...THE RECENT ONSHORE FLOW OF COLD AND MOIST AIR WILL DIMINISH AS A COLD FRONT APPROACHES FROM THE WEST. IF THE LOW CLOUDS DIMINISH FAST ENOUGH...IT COULD END UP BECOMING VERY WARM AND HUMID. SHOWERS/TSTMS ARE EXPECTED LATE AFTERNOON AND EARLY EARLY OVERNIGHT AS A COLD FRONT APPROACHES. THE SRN HALF OF OUR CWA IS IN A SLIGHT RISK FOR SVR WEATHER FRIDAY. SAT THRU MONDAY...MOSTLY FAIR WITH SEASONABLE TEMPERATURES. HIGH PRESSURE BUILDS IN SAT...CRESTS OVER THE AREA SUN AND THEN MOVES EAST MONDAY. HIGH TEMPS MOSTLY IN THE 60S SAT/SUN AND CLOSER TO 70 MON. TUE THRU WED...ANOTHER LOW PRESSURE SYSTEM FROM THE PLAINS HEADS TOWARD THE UPPER GREAT LAKES. ITS ASSOCIATED FRONTS APPROACH THE AREA. WE WENT ALONG WITH THE WPC POPS FOR THESE PERIODS WITH MOSTLY CHC POPS. TEMPERATURES WILL BE A LITTLE ABOVE NORMAL FOR MID APRIL. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE REGION REMAINS SOCKED IN LOW CLOUDS AND BR EARLY THIS MORNING. FLIGHT RESTRICTIONS MOSTLY FROM CIGS THAT ARE IN IFR RANGE. SIMILAR TO YESTERDAY, EXPECT SOME IMPROVEMENT TO MVFR DURING THE DAY WITH CIGS BETWEEN 1 AND 2 KFT AGL. THIS GRADUAL IMPROVEMENT WILL LIKELY OCCUR AT THE TERMINALS FROM NE TO SW BETWEEN 14Z AND 18Z. ONSHORE FLOW WILL LIKELY KEEP ACY AND POSSIBLY MIV IN IFR ALL DAY. CIGS LOWER AGAIN TONIGHT, BECOMING IFR LATE THIS EVE AND POSSIBLY LIFR OVERNIGHT. PERIODS OF RA, DZ AND FOG WILL LIKELY CAUSE VSBY RESTRICTIONS. THERE IS STILL SOME UNCERTAINTY WITH THE TIMING OF THE EXPECTED CIG IMPROVEMENT TODAY AND DETERIORATION TONIGHT SO FUTURE TAF UPDATES WILL PROVIDE REFINEMENT. NORTHEAST WINDS AROUND 10 KT THIS MORNING WILL VEER OUT OF THE EAST MIDDAY AND EVENTUALLY SOUTHEAST BY LATE TONIGHT. OUTLOOK... FRIDAY/FRIDAY NIGHT...A TRANSITIONAL DAY WITH THE LOW CLOUDS DEPARTING AND THEN SCT SHOWERS AND TSTMS DEVELOPING. MVFR/IFR WITH THE LOW CLOUDS EARLY AND THEN AGAIN LATE IN ANY TSTM. SAT THRU MONDAY NIGHT...MOSTLY VFR. && .MARINE... SCA IN EFFECT FOR OUR ATLANTIC COASTAL WATERS TODAY AND TONIGHT. THERE ARE STILL A FEW GUSTS IN THE 25 KT RANGE ALONG THE NJ COAST EARLY THIS MORNING BUT OVERALL ONSHORE WINDS SHOULD GRADUALLY WEAKEN DURING THE DAY TODAY. THE MORE WIDESPREAD HAZARD ON THE WATERS WILL BE THE SEAS WITH WAVES BETWEEN 5 AND 8 FT THRU TONIGHT. OUTLOOK... FRI/FRI NIGHT...SCA CONDITIONS WITH SCT SHOWERS AND TSTMS. SAT...SCA CONDITIONS EARLY THEN SUB-SCA WINDS/SEAS. SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS EXPECTED. MONDAY...SCA CONDITIONS POSSIBLE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455. && $$ SYNOPSIS...O`HARA NEAR TERM...GIGI/KLEIN SHORT TERM...KLEIN LONG TERM...O`HARA AVIATION...KLEIN/O`HARA MARINE...KLEIN/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
922 AM EDT THU APR 9 2015 .DISCUSSION...LTST WV IMAGERY ALONG WITH SOUNDING DATA FROM XMR CONFIRM AN UNFAVORABLE ENVIRONMENT EXISTS FOR DEVELOPMENT OF PCPN TODAY. E-SE WINDS FROM THE SFC THROUGH 10KFT...COUPLED WITH E- NE/INCREASINGLY ANTICYCLONIC MID LEVEL FLOW...WILL CONTINUE TO DRAW IN LOWER PWAT AIR. LTST HRRR GUID SHOWS A FEW ECHOES LIKELY ASCD WITH INLAND PROGRESSION OF MARINE CU LINES AND THE POSSIBILITY OF SOME LOW TOPPED SPRINKLES MOVING ASHORE MAINLY FROM THE TREASURE CST SWD. NO MEASURABLE RAINFALL IS ANTICIPATED FROM THIS ACTIVITY. THE CURRENT FORECAST IS IN GOOD SHAPE. && .AVIATION...VFR CONDS. SOME SCT BASES NR FL 040 REMAIN PSBL IN CU LINES ALONG THE CST AND SOMEWHAT INLAND THROUGH THE AFTN. && .MARINE...(PREVIOUS DISC) HIGH PRESSURE REMAINS IN FIRM CONTROL OF LCL WX. ESE-SE WINDS 10-15KT WITH SEAS 3FT NEAR SHORE AND 4FT AWAY FROM THE COAST. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/FJ Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1007 AM CDT Thu Apr 9 2015 .UPDATE... ISSUED AT 1007 AM CDT THU APR 9 2015 15z/10am surface analysis shows 1000mb low centered just north of Kansas City, with warm front extending eastward into northern Illinois. Front has now lifted north of the KILX CWA, placing the entire area firmly in the warm sector. Widespread early morning convection is in the process of exiting into northern Indiana, leaving behind just scattered showers/storms for the time being. Further upstream, the next upper-level impulse is triggering a renewed round of convection across western Missouri. Based on timing tools and the latest HRRR guidance, this activity will move into the SW CWA between 17z and 18z. Once this wave departs, attention will turn to the approaching cold front which is still on target for a late afternoon/early evening arrival. Airmass ahead of the front will become moderately unstable and highly sheared, so threat for strong to severe thunderstorms is still present. Current indications suggest the primary time frame will be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the main threat with the storms, although large hail and isolated tornadoes will also be possible as the cells first begin to develop. Made some changes to hourly PoPs to better reflect current and expected trends, but changes were minor and did not require a full zone update at this time. && .SHORT TERM...(Today) ISSUED AT 303 AM CDT THU APR 9 2015 Latest surface analysis shows the warm front has lifted to the I-74 corridor early this morning with a chaotic wind field across most of the forecast area. Not sure what the affect the current scattered convection will have on the position of the frontal boundary thru the morning hours, but most of the models suggest a continued slow push to the north as the main surface low tracks northeast to central Iowa by late this morning. Current thinking is that the cold front will be positioned just west of the Mississippi River by 21z with surface based convection developing ahead of the front at that time as well. Better low level helicity fields supportive of discrete supercells and possible tornadoes looks to be closer to the track of the surface low...which by late afternoon is expected to be in far southwest Wisconsin or northwest Illinois. That would put the threat for more persistent low level rotating storms just to our west and north. However, still plenty of shear ahead of the frontal boundary this afternoon and early this evening to promote damaging straight line winds as the storms transition into more of a linear system. Temperature-wise, with the warm front to our north this afternoon, will continue to go with the warmer guid values most areas. Latest model data now suggests the backedge of the precip pushes out of our far southeast counties by midnight, so will extend the Flash Flood Watch until that time this evening. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 303 AM CDT THU APR 9 2015 Showers and thunderstorms, possibly severe, will be ongoing across at least the eastern half of the forecast area to start this evening. Despite the short forecast range, there is still some spread in the expected cold frontal timing. However, it appears reasonable that the front will lie somewhere between the Illinois River and the I-55 corridor by 00Z Friday. Sped up the decrease in shower/storm chances by mid evening, and I would not be surprised to see the precipitation chances taper off a few hours earlier, especially if the squall line gets a head of steam and trends further ahead of the front than current progs. Once the front clears the area tonight, quiet conditions, along with much cooler and less humid air will build across the region into Sunday. These conditions will be driven by a large area of high pressure of Canadian origin. While conditions will be notably cooler/less humid, they will still be at or above normal for early April. The next precipitation chances will arrive later Sunday into Sunday night as a cold front is dragged across the area. While this front is still expected to stall out at it begins to parallel the upper-level flow, model trends suggest the front will stall out further south than previously anticipated. If these trends persist, Monday and Monday night will end up dry. For now, have reduced but not eliminated PoPs Monday/Monday night until we see if this recent model trend sticks. A slow moving upper-level disturbance will push the front back into the area by Tuesday, bringing renewed shower/storm chances. The front and/or upper level disturbances will keep the rain chances going into the end of the work week. Temperatures should remain at or above normal through the period. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) ISSUED AT 640 AM CDT THU APR 9 2015 Active weather day across the region with scattered thunderstorms this morning, with storms expected to redevelop this afternoon and evening along a cold front. Some of those storms will be severe with damaging wind gusts and hail possible. VFR cigs expected outside any storms, however, with any strong storm, look for cigs and vsbys to briefly drop to IFR at times. Gradient winds are expected to be rather gusty today out of the south and southwest with prevailing speeds of 15 to 25 kts with gusts around 35 kts at times. Cold front timing looks to be around the PIA site by 23z and should be east of our TAF sites by 02z. It appears the strongest storms will be about an hour or two ahead of the actual cold front this afternoon and evening. Look for sfc winds to become southwest with FROPA and with the storm system expected to deepen, a rather tight pressure gradient will produce a period of strong and gusty winds out of the southwest just after the passage of the cold front late this afternoon into the evening. Some gusts may be around 35 kts at times just after the front shifts to the east of a TAF sites early this evening. Expect the strong gusts to slowly subside, but not until after 03z. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063- 066>068-071>073. && $$ UPDATE...Barnes SHORT TERM...Smith LONG TERM...Bak AVIATION...Smith
AREA FORECAST DISCUSSION
NWS JACKSON KY
945 AM EDT THU APR 9 2015 .UPDATE... ISSUED AT 945 AM EDT THU APR 9 2015 INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 411 AM EDT THU APR 9 2015 EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO. HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE OR THE OTHER. THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z. JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN THE MID AND UPPER 60S. MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS. IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON. MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 534 AM EDT THU APR 9 2015 THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE. A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO THE 30S FOR THE MORE SHELTERED VALLEYS. A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL BOUNDARY. DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH LOWS IN THE LOW TO MID 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 656 AM EDT THU APR 9 2015 STRONG SRLY FLOW AND MOIST UNSTABLE AIR WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION TODAY...ESPECIALLY DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE WIDESPREAD CHANCES VERY LATE IN THE PERIOD...AFFECTING KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z...THEN KJKL AND KSJS AROUND 6Z OR AFTER. ONCE AGAIN...UNTIL STORMS DEVELOP...EXACT IMPACTS ARE STILL UNCERTAIN...SO WENT WITH A GENERAL MVFR AT THIS TIME. WITH ANY OF THESE STORMS...ESPECIALLY IN THE AFTERNOON AND EVENING...STRONG TO DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINS ARE A POSSIBILITY. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JVM SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...JMW
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1147 AM EDT THU APR 9 2015 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 330 AM EDT THU APR 9 2015 A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED. SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS EVENING...ESPECIALLY FURTHER SOUTH. A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY. COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE. CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT. && .UPDATE... ISSUED AT 1145 AM EDT THU APR 9 2015 THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4 PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE NORTH OF THE WARM FRONT. WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD. HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT THU APR 9 2015 THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN GENERAL. INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER. THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE. THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA. WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY DOWN SOUTH. WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR THE WARM FRONT IN THE AREA. STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT. THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI. THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES THROUGH. THIS SHOULD NOT BE SIGNIFICANT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 330 AM EDT THU APR 9 2015 IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY. THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE WEATHER. THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY. SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY RAIN TUESDAY. FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO. WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES EAST BRING INCREASED SOUTHERLY WINDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 753 AM EDT THU APR 9 2015 FOR THE MOST PART EXPECT PERIODS OF THUNDERSTORMS INTO THIS EVENING. LOW CLOUDS WITH IFR / MVFR CIGS WILL ALSO PREVAIL MOST OF THE DAY. THE WARM FRONT WILL STRUGGLE TO REACH I-94 BY LATE AFTERNOON. IF THE WARM FRONT DOES IN FACT REACH I-94 CEILINGS MAY BECOME VFR FOR A FEW HOURS. THE STRONGEST STORMS SHOULD BE THIS EVENING JUST AHEAD OF THE COLD FRONT. ONCE THE COLD FRONT COMES THROUGH WINDS WILL TURN TO THE SOUTHWEST AND INCREASE TO 20 TO 30 KNOTS. CIGS WILL REMAIN MVFR THROUGH SUNRISE FRIDAY. SHOWERS ARE POSSIBLE IN THE COLD UNSTABLE AIR BEHIND THE COLD FRONT. && .MARINE... ISSUED AT 330 AM EDT THU APR 9 2015 WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN. WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE GRADIENT RELAXES. && .HYDROLOGY... ISSUED AT 111 PM EDT WED APR 8 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY STEADY OR SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TONIGHT INTO FRIDAY. URBAN AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...63 MARINE...NJJ
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
627 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 627 AM CDT THU APR 9 2015 UPDATED FOR AVIATION DISCUSSION. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN ALL LIQUID. THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN. HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS AND HAVE REMOVED. TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED. ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS WITH DIURNAL HEATING. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE. RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE 30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL SIDE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 627 AM CDT THU APR 9 2015 LOW END MVFR AND IFR CEILINGS WILL PERSIST THROUGH TODAY...WITH SCATTERED LIFR CIGS ACROSS THE NRN TERMINALS THIS MORNING. RAIN SHOWERS...WITH EMBEDDED FZDZ/IP/SN WILL MOVE IN FROM THE SOUTH THIS MORNING AND SPREAD TO THE ENE THROUGH THE AFTERNOON. THE HYR TERMINAL WILL SEE THE MOST PRECIPITATION TODAY AND TONIGHT WITH MAINLY RAIN THROUGH THE DAY AND A CHANGE OVER TO ALL SNOW THIS EVENING AND TONIGHT. CONDITIONS WILL IMPROVE TO VFR FROM THE NW TONIGHT...WITH A BRIEF PERIOD OF IFR/MVFR VSBYS IN LIGHT FOG BEHIND THE FRONT. NE WINDS WILL CONTINUE MOST OF TODAY WITH A SHIFT TO THE NW TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 32 48 30 / 70 20 20 10 INL 50 30 48 28 / 10 40 10 0 BRD 49 31 51 29 / 60 20 20 10 HYR 42 31 47 27 / 90 80 30 10 ASX 38 31 45 29 / 100 70 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...BJT
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
916 AM MDT THU APR 9 2015 .UPDATE... MADE SOME MINOR TWEAKS FOR THE WEAK ECHOS ACROSS GLASGOW/S AREA...BUT KEPT POPS NO HIGHER THAN 14 GIVEN THAT THE HRRR DOES NOT HANG ON TO PRECIP VERY LONG. REIMER && .SHORT TERM...VALID FOR TDY AND FRI... WEAK NORTHERLY FLOW ALOFT WILL TAKE OVER TODAY AS THE SYSTEM THAT IMPACTED THE SOUTHEAST MOVES AWAY. LIGHT WINDS THIS MORNING COULD ALLOW FOR FOG FORMATION...SO WILL LET THAT PART OF THE FORECAST RIDE FOR THE EARLY PART OF THE DAY. WEAK CIRCULATION OVER NORTHERN IDAHO WILL SWING ACROSS THE SOUTHWEST MOUNTAINS THIS AFTERNOON AND EVENING. ENOUGH LINGERING MOISTURE AND WEAK INSTABILITY FOR A FEW SHOWERS OVER THE HIGHER TERRAIN DURING THE PERIOD. THE MAIN PART OF THE TROUGH HOUSING THE WEAK ENERGY OF TODAY IS PROGGED TO PUSH ACROSS THE AREA FRIDAY. ENOUGH WEAK INSTABILITY TO MENTION SHOWER CHANCES OVER THE WEST. LOW LEVEL DOWNSLOPE FLOW WILL ALLOW FOR WARMER TEMPERATURES FRIDAY AFTERNOON. TWH .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... GENERALLY FEW CHANGES TO THE EXTENDED FORECAST PERIOD...WITH GREATEST CONCERN THROUGH THE PERIOD CONTINUING TO BE IMPRESSIVE UPPER LEVEL LOW PRESSURE SYSTEM PROGGED TO MOVE ACROSS THE REGION THROUGH THE LATTER HALF OF NEXT WEEK...AT LEAST. UNTIL THEN...THE PATTERN REMAINS SOMEWHAT UNSETTLED AND PROGRESSIVE. THE PERIOD BEGINS WITH A SHORTWAVE AND ASSOCIATED COLD FRONT CROSSING THE REGION SATURDAY EVENING/NIGHT. SATURDAY CONTINUES TO LOOK LIKE THE WARMEST DAY OF THE PERIOD...IN PREFRONTAL ENVIRONMENT...WITH TEMPS AROUND 70. EXPECT TO SEE SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING INDICATING WIDESPREAD PRECIP. DRY WITH GUSTY NORTHWEST WINDS WILL FOLLOW BEHIND THE SYSTEM FOR SUNDAY. WILL NEED TO KEEP A CLOSE EYE ON THESE DAYS FOR ANY FIRE WEATHER CONCERNS. WINDS WILL BE STRONG AND GUSTY AT TIMES AND RH VALUES LOOK LIKE WILL BE BACK IN TEENS. DRY CONDITIONS PERSIST THROUGH MONDAY AND INTO TUESDAY...AS SOUTHWEST FLOW SETS UP AHEAD OF APPROACHING TROF...DEVELOPING ALONG THE WEST COAST. THERE ARE A FEW DIFFERENCES IN THE MODELS...WITH ECMWF BRINGING A WAVE INTO THE REGION ON TUESDAY AHEAD OF THE MAIN TROF...WHILE GFS REMAINS DRY. HAVE KEPT SLIGHT POPS IN PLACE THROUGH THIS PERIOD...ALTHOUGH MAY MAINLY SERVE TO RECHARGE ATMOSPHERE AFTER FEW DAYS OF DRYING OUT. MODEL COME BACK TOGETHER A BIT BETTER BY TUESDAY NIGHT...WITH LARGE UPPER LEVEL LOW PRESSURE SYSTEM MOVING INTO THE REGION. TRACK...SPEED...PRECIP AMOUNTS ARE STILL UNCERTAIN...BUT MODELS HAVE BEEN VERY CONSISTENT WITH THIS SYSTEM TRACKING ACROSS THE REGION THROUGH THE END OF THE WORK WEEK...SO HAVE KEPT HIGH POPS IN PLACE THROUGH THE PERIOD. TEMPS ARE ALSO UNCERTAIN DUE TO POTENTIAL CHANGES IN TRACK OF THE SYSTEM...SO WILL HAVE TO BE MONITORED CLOSELY. AAG && .AVIATION... VFR CONDITIONS SHOULD PREVAIL TODAY AT ALL TERMINALS. THE THREAT OF FOG OVER THE EASTERN TERMINALS HAS DIMINISHED. LATER TODAY THERE IS A SLIGHT CHANCE OF A MOUNTAIN SNOW SHOWER...SO MOUNTAIN OBSCURATION RULES MAY APPLY. SINGER && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 057 036/065 040/069 040/061 033/064 039/060 038/052 0/B 01/B 02/W 31/N 11/B 33/W 45/W LVM 055 033/061 037/063 034/056 030/059 035/058 034/049 1/B 13/W 03/W 31/N 12/W 33/W 55/W HDN 059 031/067 035/071 038/062 031/066 036/065 034/053 0/B 01/B 02/W 31/N 11/B 33/W 45/W MLS 057 032/065 037/070 039/061 032/065 038/065 038/053 1/B 00/U 02/W 31/N 11/B 22/W 45/W 4BQ 053 029/064 035/070 038/060 031/066 037/067 036/054 0/B 00/B 01/U 31/B 11/B 32/W 45/W BHK 053 028/062 033/068 037/059 030/064 036/067 035/056 1/B 00/U 01/U 21/N 11/B 22/W 45/W SHR 052 027/061 033/066 036/058 031/064 035/064 034/051 0/B 00/B 01/B 31/B 11/B 33/W 45/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
619 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT THU APR 9 2015 TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN THE SANDHILLS. THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE NORTHWEST AT THE SAME TIME. THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER 40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH. HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES FOR LOWS IN THE UPPER 20S TO LOWER 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM CDT THU APR 9 2015 RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS. WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA. BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT SPREAD EAST ONTO THE PLAINS. TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD COOL TEMPERATURES BACK BELOW NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 618 AM CDT THU APR 9 2015 IFR CIGS AND VSBY IN RASN COVERING WRN AND NCNTL NEB ARE EXPECTED TO IMPROVE MARKEDLY AS EARLY AS 18Z WITH VFR/MVFR CIGS SPREADING EAST THROUGH THE FCST AREA THIS AFTN. VFR IS EXPECTED ALL AREAS FROM 00Z ONWARD THIS EVENING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
958 AM EDT THU APR 9 2015 .SYNOPSIS... A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1000 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN WILL DRIFT SLOWLY NORTH THIS AFTERNOON AND EVENING. WILL HOLD TO LIKELY POPS THROUGH NOON ACRS SE SECTIONS. NONE OF THE MODELS IS REALLY HANDLING THIS PRECIPITATION WELL BUT IT STILL LOOKS LIKE A LULL IN THE EARLY AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO EARLY EVENING THE HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG CONVECTION REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT BY THE LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING THIS TIME. SOME STORMS COULD BE ON THE STRONG SIDE LATE AFTN/EVE. WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE AND WILL LIKELY LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH. MADE SOME ADJUSTMENTS TO INIT T/TD. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS. THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE 60S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT WITH PREVIOUS FCST REST OF PERIOD. MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING EVENING HOURS...AND OVERNIGHT ALONG COAST. SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING TUE NIGHT AND CONTINUING WED. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 10 AM THURSDAY...MAIN CHANGE WAS TO REMOVE IFR CIGS FROM OAJ AND HAVE TSRA IN FCST UNTIL ABT 16Z. WIDESPREAD LIFR/IFR CONDITIONS WILL PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING HOURS ACCORDING TO THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH LAMP MOS. IFR CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS BELOW NORMAL AT THIS TIME. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH MONDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1000 AM THURSDAY...MAIN CHANGE TO INCREASE SEAS TO 5 FT ACRS THE NRN AND CNTRL CSTL WATERS THROUGH EARLY AFTN. DENSE FOG ADVISORY CONTS FOR THE WATERS THIS MORNING. THE FOG SHOULD DISSIPATE WITH SUSTAINED HEATING LATE THIS MORNING. BACK DOOR COLD FRONT HAS MOVED THROUGH THE NORTHERN AND CENTRAL WATERS INCLUDING THE SOUNDS AND IS STALLING AS FORECAST OVER THE SOUTHERN WATERS EARLY THIS MORNING. WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE FRONT. LATER TODAY WINDS GRADUALLY RETURN TO THE S-SW AS FRONT RETREATS BACK NORTH. TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT LATE. SEAS 2 TO 4 FT TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST. TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY. BLEND OF PREVIOUS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131- 135>137-150-152-154-156-158. && $$ SYNOPSIS...JME NEAR TERM...JAC/JME SHORT TERM...JME LONG TERM...JBM AVIATION...JAC/JME/JBM MARINE...JAC/JME/JBM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 AM EDT THU APR 9 2015 .SYNOPSIS... A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 700 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN AND APPEARS TO HAVE STALLED AS FORECAST. THE FRONT WILL THEN DRIFT SLOWLY NORTH THIS AFTERNOON AND EVENING. CONVECTION CURRENTLY OVER THE COASTAL PLAIN IS INCREASING IN COVERAGE AND INTENSITY AND WILL NEED TO INCREASE POPS TO LIKELY FOR THE EARLY MORNING HOURS. NONE OF THE MODELS IS REALLY HANDLING THIS PRECIPITATION WELL BUT IT STILL LOOKS LIKE A LULL IN THE EARLY AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO EARLY EVENING THE HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG CONVECTION REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT BY THE LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING THIS TIME. ALTHOUGH WE ARE NOT OUTLOOKED BY THE SPC FOR SEVERE STORMS IT WILL BECOME MODERATELY UNSTABLE AND GIVEN THE THERMAL AND KINEMATIC PROFILES COMMON THIS TIME OF YEAR, STORMS COULD BRIEFLY BECOME SEVERE WITH DAMAGING WIND GUSTS AND LARGE HAIL POSSIBLE. WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE TODAY AND COULD LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS. THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE 60S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT WITH PREVIOUS FCST REST OF PERIOD. MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING EVENING HOURS...AND OVERNIGHT ALONG COAST. SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING TUE NIGHT AND CONTINUING WED. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...WIDESPREAD LIFR/IFR CONDITIONS WILL PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING HOURS ACCORDING TO THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH LAMP MOS. IN ADDITION TO THE FOG AND STRATUS NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECTING THE TAF SITES THROUGH ABOUT 14Z WITH DOWNPOURS AND GUSTY WINDS. CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS BELOW NORMAL AT THIS TIME. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH MONDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...DENSE FOG INDICATED IN MARINE OBSERVATIONS HAS PROMPTED THE ISSUANCE OF DENSE FOG ADVISORY FOR ALL OF THE WATERS THIS MORNING. THE FOG SHOULD DISSIPATE WITH SUSTAINED HEATING LATE THIS MORNING. BACK DOOR COLD FRONT HAS MOVED THROUGH THE NORTHERN AND CENTRAL WATERS INCLUDING THE SOUNDS AND IS STALLING AS FORECAST OVER THE SOUTHERN WATERS EARLY THIS MORNING. WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE FRONT. LATER TODAY WINDS GRADUALLY RETURN TO THE S-SW AS FRONT RETREATS BACK NORTH. TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT LATE. SEAS 2 TO 4 FT TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST. TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY. BLEND OF PREVIUOS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131- 135>137-150-152-154-156-158. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...JBM AVIATION...JME/JBM MARINE...JME/JBM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 350 AM THURSDAY... SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES. HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT. MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY... WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S. THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON... WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 650 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: IFR/LIFR CIGS THROUGH THE MORNING AT RWI/RDU/GSO/INT WITH LESSER CHANCES AT FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC LAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC... WITH LOW CLOUDS BASED UNDER 1000 FT AGL AND NORTHEASTERLY WINDS HAVING SPREAD INTO NRN/ERN NC FROM VA OVERNIGHT. SCATTERED STORMS AFFECTED MOST CENTRAL NC TAF SITES OVERNIGHT WITH SHORT-LIVED MVFR VSBYS AND HEAVY DOWNPOURS. THE CURRENT IFR/LIFR CIGS SHOULD RISE TO MVFR BY LATE MORNING TO EARLY AFTERNOON... THEN TO VFR BY MID AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY DURING THE LAST 6 HOURS OF THE TAF VALID PERIOD... PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 12Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD MIX UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...RAH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1022 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 1022 AM CDT THU APR 9 2015 LAST FEW RUNS OF THE HRRR ALONG WITH THE 4KM WRF ALL INDICATE ISOLATED SHOWERS DEVELOPING THIS AFTERNOON SO HAVE ADDED THIS INTO THE FORECAST. KEPT QPF AT ZERO AS ONLY EXPECTED TRACE AMOUNTS OF MOISTURE. OTHERWISE THE INHERITED FORECAST IN GOOD SHAPE. CU FIELD SHOULD DEVELOP BY EARLY TO MID AFTERNOON ALONG TO AHEAD OF A SFC COLD FRONT MOVING SOUTH THROUGH NORTH DAKOTA TODAY. WINDS STILL LOOK BREEZY...ESPECIALLY MID TO LATE DAY WHEN WE ARE PROJECTED TO MIX OUT TO AROUND 700MB. ANY SHOWER ACTIVITY WILL AID IN GUSTY WINDS WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES. UPDATE ISSUED AT 630 AM CDT THU APR 9 2015 PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY. OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 1022 AM CDT THU APR 9 2015 ALL TERMINALS WILL REMAIN VFR TODAY AND TONIGHT. A FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...KS LONG TERM...TWH AVIATION...TWH/NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
631 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 630 AM CDT THU APR 9 2015 PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY. OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 630 AM CDT THU APR 9 2015 VFR CIGS WILL RETURN TO KDIK BETWEEN 12Z AND 13Z THURSDAY...AND MAY BE IN AND OUT THROUGH 15Z WITH SOME SCATTERED IFR CEILING IN THE NEIGHBORHOOD. THE REST OF THE TERMINALS WILL REMAIN VFR. A FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...KS LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1016 AM EDT THU APR 9 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1015 AM UPDATE...AS WITH THE PAST SEVERAL DAYS...THE HRRR IS BEGINNING TO LATCH ON TO YET ANOTHER CONVECTIVE COMPLEX FOR THIS AFTERNOON. HRRR DID FAIRLY WELL THE LAST COUPLE DAYS...SO USED THAT TO UPDATE POPS THROUGH THIS EVENING. EXPECTING A COMPLEX TO MOVE NE ACROSS CWA...WITH THE MAIN ACTIVITY ALONG AND WEST OF THE OHIO RIVER...AND MORE SCATTERED CONVECTION ACROSS EASTERN HALF OF CWA. PREVIOUS DISCUSSION...MODELS SHOWING SHOWERS AND THUNDERSTORMS CONTINUING OVER NORTHERN WEST VIRGINIA EARLY THIS MORNING. WITH MUCH OF THE AREA ALREADY SATURATED...FEEL THAT A FLASH FLOOD WATCH IS PRUDENT FOR THE REMAINDER OF THE NORTHERN WV COUNTIES IN OUR FORECAST AREA. WITH THUNDERSTORMS POSSIBLE AGAIN THIS AFTERNOON AND EVENING AND IN ADVANCE OF THE COLD FRONT ON FRIDAY...WILL GO AHEAD AND EXTEND THE ENTIRE FLASH FLOOD WATCH INTO FRIDAY. BASED ON MESO MODELS SHOWING PRE-FRONTAL PRECIPITATION WITH THE FRONTAL BOUNDARY LATE THURSDAY NIGHT...WILL SPEED UP AND INCREASE POPS SOME. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... PREFRONTAL BAND WILL BE RACING THRU AREA EARLY FRIDAY MORNING...FOLLOWED BY ACTUAL SURFACE FRONT. HOPEFULLY THIS PREFRONTAL BAND WILL BE ON A WEAKENING TREND AS IT COMES THRU GIVEN TIME OF DAY AND SEPARATION FROM BETTER DYNAMICS. STILL...A STOUT LLJ IS WORRISOME FOR DAMAGING WIND THREAT. THERE MAY BE SOME REJUVENATION ALONG THE ACTUAL COLD FRONT BY THE TIME IT GETS INTO THE MOUNTAINS BY LATE MORNING OR MIDDAY. MAY SEEM SOME SUN FRIDAY AFTERNOON AMID SOME BREEZY CONDITIONS IN THE DRY SLOT ALOFT. TRUE CAA HOLDS OFF UNTIL SATURDAY AS THE UPPER TROF SWINGS THRU. NOT EXPECTING ANY PRECIP JUST AN EXPANSIVE STRATOCU FIELD...MOST NOTICEABLE ACROSS N ZONES. HIGH PRESSURE BUILDS IN SATURDAY NIGHT AND WITH A CLEAR SKY...THINK THERE COULD BE SOME FROST CONCERNS IN THE LOWLANDS. WE HAVE NOT STARTED THE GROWING SEASON JUST YET...BUT SOMETHING TO KEEP IN MIND FOR THOSE EAGER GREEN THUMBS. THE HIGH SLIDES OFF TO THE E ON SUNDAY BUT STILL A NICE DAY WITH MILD TEMPS. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR RESTRICTIONS. SOME MVFR FOG/STRATUS IS POSSIBLE EARLY THIS MORNING IN AREAS RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY VFR CLOUDS CAN BE EXPECTED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013- 014-017-019-020. FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018- 024>032-037>040-046-047. OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075- 076-083>087. KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...RPY/SL/30 NEAR TERM...RPY/MZ SHORT TERM...30 LONG TERM...SL AVIATION...RPY
AREA FORECAST DISCUSSION
NWS PORTLAND
846 AM PDT THU APR 9 2015 .SYNOPSIS...HIGH PRESSURE OVER THE REGION WILL LEAD TO MAINLY DRY CONDITIONS TODAY WITH PERHAPS A SPOTTY SHOWER DEVELOPING OVER THE HIGHER CASCADE TERRAIN IN THE AFTERNOON. FRIDAY WILL LIKELY REMAIN DRY DURING THE DAY FOR MOST OF THE REGION...BUT CLOUDS AND RAIN WILL SPREAD INTO THE REGION DURING THE LATE AFTERNOON AND EVENING HOURS. A COOL SHOWERY PATTERN WILL FOLLOW ON SATURDAY WITH MOST OF THE AREA LOOKING DRY ON SUNDAY AND EARLY MONDAY. ANOTHER COOL AND WET STORM SYSTEM LOOKS TO ARRIVE EARLY NEXT WEEK BEFORE HIGH PRESSURE BRINGS DRIER AND WARMER WEATHER BEGINNING THE MIDDLE OF NEXT WEEK. && .UPDATE...FOG CONTINUES ALONG THE COAST AND IN THE VALLEYS THIS MORNING AND ALTHOUGH PATCHES OF DENSE FOG REMAIN...IMPROVEMENT IN VISIBILITY IS ALREADY BEING SEEN AT SOME AREA OBSERVATION SITES. EXPECT VISIBILITIES TO IMPROVE ACROSS THE BOARD BY LATE MORNING. NO MAJOR UPDATES NEEDED THIS MORNING AS THE FORECAST APPEARS TO BE ON TRACK. TWEAKED NEAR-TERM SKY GRIDS A BIT TO ACCOUNT FOR FOG AND THEN AFTERNOON CLEARING. THE 12Z GFS IS HINTING AT A SLIGHT CHANCE OF SHOWERS IN THE LOWER COLUMBIA AREA THIS AFTERNOON...BUT BOTH HRRR AND RUC KEEP ANY POPS IN THE CASCADES AND MAYBE FOOTHILLS SO WILL KEEP POP/WX FORECAST AS IS THROUGH THIS EVENING. BOWEN .SHORT TERM (PREVIOUS DISCUSSION)...TODAY THROUGH SUNDAY...SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE A FEW PATCHES OF CLOUDS SCATTERED ABOUT THE REGION...WITH MOST HUGGING THE CASCADE FOOTHILLS. SOME PATCHY FOG IS BEGINNING TO DEVELOP IN THE SOUTHERN WILLAMETTE VALLEY...AND EXPECT ADDITIONAL FOG DEVELOPMENT THIS MORNING AS THE LOWER ATMOSPHERE STABILIZES AND SATURATES...PARTICULARLY AROUND EUGENE...CORVALLIS...MCMINNVILLE AND HILLSBORO. A VORT MAX AND WEAK UPPER LEVEL SHORTWAVE TROUGH WILL HANG OVER THE COLUMBIA RIVER BASIN TODAY. THE SOUTH WASHINGTON CASCADES AND NORTH OREGON CASCADES WILL REMAIN CLOSE ENOUGH TO THIS INSTABILITY THAT A SPOTTY LIGHT SHOWER MAY DEVELOP LATER THIS AFTERNOON...BUT THESE SHOULD REMAIN RATHER ISOLATED AND MORE NUISANCE IN NATURE. OTHERWISE...MOST LOCATIONS SHOULD EXPECT MOSTLY SUNNY SKIES AND TEMPERATURES RISING SEVERAL DEGREES ABOVE NORMAL ONCE THE FOG BURNS OFF MID TO LATE MORNING. FRIDAY LOOKS LARGELY DRY ACROSS THE AREA BEFORE A COLD FRONT PUSHES RAIN INTO OUR NORTHWEST COAST DURING THE LATE AFTERNOON HOURS. RAIN WILL LIKELY PUSH INLAND DURING THE LATE EVENING AND OVERNIGHT HOURS. THE MAIN UPPER LEVEL SUPPORT AND DEEPER INSTABILITY WITH THIS FRONT WILL JUST CLIP OUR NORTHERN ZONES LATE FRIDAY NIGHT INTO SATURDAY MORNING SO THERE IS SOME CONCERN THE CURRENT QPF FORECAST MAY BE A BIT TOO HIGH ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. SUFFICIENT INSTABILITY ON SATURDAY SHOULD LEAD TO ADDITIONAL SHOWERS DEVELOPING OVER THE INTERIOR DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE THE ATMOSPHERE STABILIZES AND PRECIPITATIONS CHANCES RAPIDLY DECREASE SATURDAY NIGHT. IT APPEARS THE INSTABILITY WILL BE SHALLOW ENOUGH THAT THUNDERSTORMS DO NOT APPEAR LIKELY ON SATURDAY EVEN ACROSS THE FAR NORTH. MODELS CONTINUE TO TREND TOWARDS THE IDEA THAT SUNDAY WILL END UP LARGELY DRY ACROSS MOST OF THE FORECAST AREA SO POPS WERE NUDGED DOWNWARD DURING THIS PERIOD...ESPECIALLY ACROSS OUR SOUTHERN ZONES. A WEAK LOW LEVEL TROUGH MAY PUSH INTO WESTERN WASHINGTON DURING THIS PERIOD AND BRING A FEW LIGHT RAIN SHOWERS TO EXTREME NORTHWEST OREGON AND SOUTHWEST WASHINGTON COASTAL AND COAST RANGE ZONES SO CHANCE POPS WERE MAINTAINED ACROSS THESE ZONES DURING THIS PERIOD. /NEUMAN .LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...MODELS SEEM TO BE CONVERGING ON THE IDEA THAT A LARGE SHORTWAVE TROUGH WILL SWING EASTWARD OUT OF THE GULF OF ALASKA AND IMPACT THE PACIFIC NORTHWEST EARLY NEXT WEEK. MAINTAINED CHANCE POPS ON MONDAY DUE TO UNCERTAINTY IN TIMING...BUT MODELS SEEM TO BE TRENDING TOWARDS RAIN ARRIVING LATE MONDAY. DEEP POST FRONTAL INSTABILITY...STRONG ONSHORE FLOW AND SNOW LEVELS LOWERING INTO THE 3KFT RANGE MAY LEAD TO HIGHLIGHT WORTHY SNOW IN THE CASCADES WITH THIS EVENT. LEFT THUNDER OUT OF THE FORECAST FOR TUESDAY FOR NOW DUE TO THE UNCERTAINTY IN THE SYNOPTIC SCALE PATTERN...BUT IF CONFIDENCE GROWS THE AFOREMENTIONED PATTERN WILL COME TO FRUITION...IT WILL ALMOST CERTAINLY NEED TO BE ADDED IN COMING SHIFTS. MODELS SEEM TO BE TRENDING TOWARDS DECENT SHORTWAVE RIDGING BUILDING INTO THE PACIFIC NORTHWEST WEDNESDAY AND BEYOND SO TEMPERATURES WERE NUDGED UPWARDS AND POPS AND SKY COVER WERE TRENDED DOWN. /NEUMAN && .AVIATION...HIGH PRESSURE OVER THE AREA HAS ALLOWED FOG TO DEVELOP IN THE WILLAMETTE VALLEY AND ALONG THE COAST. FOG SHOULD LIFT TO LOW STRATUS IMPROVING VIS BY AROUND 16-17Z. CONDITIONS SHOULD IMPROVE TO VFR BY 18-20Z. WINDS HAVE TURNED OFFSHORE ALONG THE COAST...WHICH WILL HELP CLEAR THESE SITES TO VFR BY 18Z AS WELL. VFR CONDITIONS TO PERSIST THIS AFTERNOON. WE MAY SEE SOME VALLEY FOG DEVELOP TONIGHT INLAND...BUT THIS SHOULD CLEAR OUT EARLY TOMORROW MORNING AS WINDS START TO INCREASE OUT OF THE SOUTH AHEAD OF OUR NEXT FRONT WHICH MOVES THROUGH TOMORROW EVENING. KPDX AND APPROACHES...IFR/LIFR CONDITIONS THIS MORNING SHOULD START TO IMPROVE AS FOG LIFTS TO LOW STRATUS BY 16Z. STRATUS SHOULD BURN OFF RAPIDLY...FURTHER IMPROVING CONDITIONS TO VFR BY 18Z. -MCCOY && .MARINE...HIGH PRESSURE OVER THE REGION IS KEEPING SEAS DOWN AROUND 3 FT WITH WIND BELOW 10 KTS TODAY. FRONTAL SYSTEM APPROACHING THE WATERS WILL BACK WINDS TO THE SOUTHWEST BY FRIDAY MORNING AND START TO RAMP UP WINDS AND BUILD SEAS THROUGH THE DAY FRIDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR WINDS AND SEAS ON FRIDAY AFTERNOON...AS WINDS ARE EXPECTED TO PEAK AHEAD OF THE FRONT IN THE AFTERNOON/EVENING HOURS AROUND 20 TO 25 KTS WITH GUSTS TO 30 KTS. WINDS STAY UP AROUND 15 TO 25 KTS BEHIND THE FRONT...FINALLY STARTING TO DECREASE SATURDAY EVENING. SEAS WITH THIS SYSTEM BUILD TO AROUND 10 TO 12 FT FRIDAY AFTERNOON/EVENING AS WELL...AND FALL TO AROUND 8 TO 10 FT BY SATURDAY MORNING. THE TIME PERIOD WITH SEAS BELOW 10 FT WILL LIKELY ONLY LAST UNTIL SATURDAY EVENING...AND SEAS IN THE OUTER WATERS MAY NEVER DROP BELOW 10 FT. A 10 TO 11 FT SWELL TRAIN MOVES INTO THE WATERS SATURDAY EVENING...BRINGING SEAS UP ABOVE 10 FT THROUGH AT LEAST MONDAY MORNING. ANOTHER FRONT IS EXPECTED TO MOVE THROUGH SOMETIME EARLY NEXT WEEK. -MCCOY && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 AM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION TODAY. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. WIDESPREAD LOW CLOUDS AND RIDGE SHROUDING FOG WILL PERSIST THIS MORNING...BEFORE SLOWLY LIFTING AS SFC TEMPS MODERATE A BIT THIS AFTERNOON. SHOWERS OVER WESTERN PA MAY SNEAK INTO OUR FAR WESTERN LAYER OF COUNTIES BEFORE DIMINISHING IN THE INCREASINGLY STABLE AIRMASS. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...SHOWERS FORMING IN THE UNSTABLE AIRMASS OVER THE OHIO VALLEY ARE MADE TO SURVIVE THE TREK INTO CENTRAL PA LATER THIS AFTERNOON AND THIS EVENING AS THE HRRR SHOWS AN EROSION OF THE WESTERN EDGE OF THE STABLE COOL-AIR-DAMMING. CAN`T RULE OUT LATE DAY-EARLY EVENING SEVERE THREAT OVER WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES ON THE EDGE OF THE INSTABILITY NEAR OUR STATIONARY BOUNDARY. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... CLUSTERS/BKN LINE OF STRONG TO POTENTIALLY SEVERE TSRA ACROSS THE OHIO VALLEY THIS AFTERNOON/EVENING WILL HEAD INTO INCREASINGLY STABLE LLVL CONDITIONS ACROSS CENTRAL AND ERN PENN AND GRADUALLY WEAKEN TONIGHT. STILL...A LARGE AREA AND NEARLY OFF THE CHART/ANOMALOUSLY STRONG /PLUS 5-6 SIGMA/ 850 MB MOISTURE FLUX /SHOWN ON THE 00Z GEFS AND 03Z SREF/ WILL SLIDE NORTHEAST ACROSS MUCH OF CENTRAL AND NWRN PENN. THIS WILL LEAD TO AREAS OF MODERATE...TO BRIEFLY HEAVY SHRA /THOUGH MAINLY LIMITED TO THE NW HALF OF PENN/. 12 TO 24 HOUR RAINFALL TONIGHT THROUGH FRIDAY /AS DEPICTED BY OPERATIONAL MODELS AND ENSEMBLES/ OF JUST 0.25-0.50 OF AN INCH ACROSS MAINLY THE NW HALF OF PENN WILL BE SURPRISINGLY LIGHT GIVEN SUCH STRONG LLVL MOISTURE FLUX. HOWEVER...THE KEY TO THE LIGHTER THAN EXPECTED QPF APPEARS TO BE LINKED TO THE LACK OF FAVORABLE JET DYNAMICS/LIFT AS THE RIGHT EXIT REGION OF A 100 KT UPPER JET SLIDES NE ACROSS LAKE ERIE AND NW PENN LATE TONIGHT AND FRIDAY MORNING. SPC GREATLY TRIMMED BACK THEIR DAY 1 CONVECTIVE OUTLOOK AREA PREVIOUS ERN EXTENT OF THE SLIGHT RISK AND ENHANCED THREAT AREAS OVER WESTERN PENN HAVE BEEN PULLED BACK WELL INTO CENTRAL AND WESTERN OHIO. ERN EDGE OF THE MARGINAL THREAT AREA NIPS OUR FAR WESTERN ZONES FOR THIS EVENING AND TONIGHT. APPROX 990 MB SFC LOW OVER THE UPPER GLAKES AT 12 FRIDAY WILL PUSH ITS SWD TRAILING COLD FRONT THROUGH CENTRAL PENN DURING THE LATE MORNING AND AFTERNOON HOURS FRIDAY. THE TIMING OF THIS CFROPA FAVORS ANY CHC OF STRONG TO POTENTIALLY ISOLATED SVR TSRA BEING LIMITED TO PRIMARILY THE MIDDLE AND LOWER SUSQ VALLEY AFTER 18Z FRIDAY. SPC MARGINAL AND SLIGHT RISK AREAS FOR DAY 2 COVER THE SE THIRD OF THE CWA. TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE /WHERE THE 03Z SREF SHOWS ABOUT A 30-40 PERCENT PROBABILITY OF CAPE EXCEEDING 1000 J/KG/. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR CONDITIONS ACROSS THE REGION THIS MORNING. THERE COULD BE SOME SLOW IMPROVEMENT THIS AFTERNOON...BUT ALL TERMINALS WILL MAINTAIN CEILINGS IN THE 500-1500` RANGE AT BEST. JOHNSTOWN MAY STAND THE BEST CHANCE OF BRIEFLY GOING VFR BEING CLOSE TO THE WARM FRONT STACKED UP OVER THE ALLEGHENIES...BUT CONFIDENCE IN SIG IMPROVEMENT IS NOT HIGH. WIDESPREAD IFR/MVFR WILL CONTINUE OVERNIGHT UNTIL THE COLD FRONT PASSES DURING THE DAY FRIDAY. LLWS IS POSSIBLE BEHIND THE LINE WITH WITH SFC WINDS REMAINING OUT OF THE SOUTHEAST...AND WINDS BETWEEN 1500 TO 2KFT AT 40KTS POSSIBLE TONIGHT BEGINNING IN THE WEST AROUND 07Z TO 11Z AT LNS. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
645 AM CDT THU APR 9 2015 .AVIATION... ACTIVE WEATHER CONTINUES ACROSS THE CENTRAL PART OF THE CONUS IN ASSOCIATION WITH AN UPPER LEVEL TROUGH CURRENTLY TRAVERSING THE CENTRAL PLAINS. NORTH TEXAS RESIDES ON THE SOUTHERN EXTENT OF THE LIFT ASSOCIATED WITH THE SYSTEM...WHICH WHEN COMBINED WITH THE STRONG LOW LEVEL JET IN PLACE...HAS RESULTED IN ELEVATED CONVECTION ACROSS PARTS OF THE AREA. THE EAST-WEST AXIS OF STORMS HAS SHIFTED TO BETWEEN THE DALLAS-FORT WORTH METROPLEX AND KACT...AND WILL LIKELY PERSIST IN THIS REGION UNTIL THE LOW LEVEL JET MIXES OUT MID MORNING. ADDITIONAL THUNDERSTORMS WILL BECOME LIKELY THIS AFTERNOON AS A COLD FRONT SURGES SOUTH INTO NORTH TEXAS. THE FRONT WILL BE REACHING THE METROPLEX DURING PEAK HEATING HOURS LATE THIS AFTERNOON...WITH SCATTERED THUNDERSTORMS DEVELOPING IN THE VICINITY OF THE BOUNDARY. STORMS SHOULD INITIALLY BE SCATTERED IN NATURE IN AND AROUND THE METROPLEX BEFORE EVOLVING INTO A SQUALL LINE AS THE FRONT PUSHES FARTHER SOUTH AND EAST ACROSS THE WACO AREA THIS EVENING. THE LATEST MODEL GUIDANCE SUGGESTS FROPA IN THE METROPLEX AROUND 00-02Z THEN IN THE WACO AREA 04-06Z. FOR NOW...WE WILL MAINTAIN VCTS IN AREA TAFS BUT LATER FORECASTS MAY REQUIRE THE ADDITION OF A TEMPO GROUP FOR THUNDER DEPENDING ON FUTURE TRENDS. ACTIVITY SHOULD SHIFT SOUTH AND EAST OF ALL TAF LOCATIONS AROUND 10/O6Z ALONG WITH THE FRONT. 30 && .UPDATE... A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS. THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20 CORRIDOR THIS MORNING. 58 && .PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/ A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BR