Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/31/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
446 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A COASTAL FRONT OVER COASTAL CONNECTICUT...WILL LIFT NORTH THIS
MORNING...AND MERGE WITH THE WARM FRONT TO OUR NORTH. A PRE-
FRONTAL TROUGH BEGINS TO PUSH INTO WESTERN PORTIONS OF THE TRI-
STATE THIS AFTERNOON...THEN STALLS OVER THE AREA FROM TONIGHT INTO
WEDNESDAY...WITH A COLD FRONT MOVING INTO WESTERN PARTS OF THE
TRI-STATE WEDNESDAY AFTERNOON...AND PUSHING SOUTH AND EAST OF THE
AREA BY THURSDAY MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE
AREA THROUGH FRIDAY. LOW PRESSURE WILL TRACK FROM THE OHIO VALLEY
THROUGH SOUTHEAST CANADA FRIDAY THROUGH SUNDAY SENDING A FRONTAL
SYSTEM THROUGH THE AREA ON SATURDAY. WEAK HIGH PRESSURE RETURNS
FOR MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COASTAL FRONT CURRENTLY STRETCHES FROM THE SW CT COAST BACK SE
INTO THE TWIN FORKS OF LONG ISLAND...AREAS OF FOG WILL PERSIST TO
THE N OF THIS FRONT UNTIL A COUPLE OF HOURS AFTER SUNRISE...WHEN A
COMBINATION OF SOLAR HEATING AND THE FRONT LIFTING N ALLOW FOR THE
FOG TO DISSIPATE. THERE ARE SOME PATCHES OF DENSE FOG IN THIS
AREA...SO WILL GO AHEAD AND EXPAND THE SPS FOR LOCALLY DENSE FOG
TO INCLUDE ALL OF SW CT AND COASTAL SE CT. WILL NOT INCLUDE
EASTERN SUFFOLK COUNTY FOR NOW...AS THE AREA IMPACTED IS VERY SMALL.
ALL MODELS OTHER THAN THE HRRR AND ECMWF ARE OVER DOING THE EXTENT
OF SHRA/TSTM EARLY THIS MORNING...SO HAVE GONE WITH THE OUTLIERS
IN THIS CASE...AND HAVE GONE WITH A DRY FORECAST INTO MID MORNING.
AN APPROACHING PRE-FRONTAL TROUGH WILL SERVE AS THE TRIGGER FOR
MAINLY ISOLD-SCT SHRA/TSRA FROM LATE THIS MORNING INTO THIS
AFTERNOON...WITH SHRA/TSRA BECOMING LIKELY N AND W OF NYC BY LATE
AFTERNOON.
THE SEVERE POTENTIAL TODAY IS VERY LOW...DUE TO RELATIVELY LOW
VALUES OF SHEAR...ONLY 15-25 KT OF 0-6 KM BULK SHEAR...DOWNDRAFT
CAPES OF 800 J/KG OR LESS AND LOW LEVEL JET OF 15-25 KT OVER THE
INTERIOR - MINIMIZING THE SEVERE WIND THREAT...AND WET-BULB ZERO
HEIGHTS AROUND 11000 FT MINIMIZING THE SEVERE HAIL THREAT. THE LOW
VALUES OF SHEAR ALSO HELP KEEP BULK RICHARDSON VALUES GENERALLY
ABOVE 50...AND IN SOME CASES WELL ABOVE 50...PROMOTING MAINLY
PULSE STORMS. HOWEVER...WITH FORECAST CAPES OF 1500-2500 J/KG AND
LIFTED INDICES OF -4 TO -8 ACROSS THE INTERIOR...ISOLATED PULSE
SEVERE STORMS CANNOT BE COMPLETELY RULED OUT...WITH THE BEST
CHANCE MAINLY TO THE N AND W OF NYC. HAVE PUT THE POTENTIAL FOR
GUSTY WINDS IN FOR AREAS WITH LIKELY POPS THIS AFTERNOON AS A RESULT.
FOR HIGHS TODAY...USED A BLEND OF MIXING DOWN FROM 975 HPA NEAR
THE COAST...850 HPA INLAND...WITH MET/MAV GUIDANCE AND NAM 2-METER
TEMPERATURES. FORECASTING VALUES 10-15 DEGREES ABOVE NORMAL - WITH
A FEW AREAS IN THE NYC METRO GETTING TO OR RIGHT ABOVE 90. WITH
DEWPOINTS FORECAST TO THE UPPER 60S...EXPECT HEAT INDICES
GENERALLY IN THE LOWER 90S ACROSS THE INTERIOR.
THERE IS A MODERATE RISK OF RIP CURRENTS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
THE PRE-FRONTAL TROUGH WILL STALL OUT ACROSS THE FORECAST AREA
TONIGHT...THIS COUPLED WITH THE PASSAGE OF A 700 HPA SHORTWAVE
WARRANTS LIKELY POPS FOR SHRA/TSRA ACROSS THE REGION TONIGHT. BULK
SHEAR INCREASE TONIGHT...FORECAST TO 35-45 KT OVERNIGHT...WITH
BULK RICHARDSON NUMBERS FORECAST TO DECREASE TO 20-40 LATE. AS A
RESULT...COULD SEE SOME ORGANIZED STORMS LATE TONIGHT...MAINLY
OVER EASTERN ZONES BEFORE THE 700 HPA SHORTWAVE EXITS. ALSO WITH
LIFTED INDICES AROUND -4 OVERNIGHT...AN ISOLATED SEVERE STORM
CANNOT BE RULED OUT AS WELL. FOR LOWS USED A BLEND OF MET
GUIDANCE...BIAS CORRECTED MAV GUIDANCE...AND NAM 2-METER
TEMPERATURES. THIS YIELDED LOWS 10-15 DEGREES ABOVE NORMAL.
A COLD FRONT MOVING IN FROM THE GREAT LAKES CATCHES UP TO/MERGES
WITH THE PRE-FRONTAL TROUGH OVER WESTERN ZONES BY WEDNESDAY
AFTERNOON. AS A RESULT HAVE A CHANCE FOR SHRA/TSTM ALONG AND AHEAD
OF IT. WITH BULK SHEAR OF 35-45 KT...1000-1500 J/KG OF
CAPE...AROUND 1000 J/KG OF DOWNDRAFT CAPE...AND BEING IN THE RIGHT
REAR QUADRANT OF A 85-90 KT 300 HPA JET...DO HAVE A BETTER
CONDITIONAL SEVERE THREAT THAN TODAY...WITH BULK RICHARDSON
NUMBERS GENERALLY FROM 20-40 - SUGGESTING A POTENTIAL FOR MULTI-
CELLULAR CLUSTERS AND POSSIBLE SUPER-CELLS. HOWEVER...WE ARE
FORECAST TO HAVE A LOW- MID LEVEL CAP...THAT MIGHT NOT HAVE ENOUGH
FORCING TO OVERCOME...AND THUS COULD REMAIN DRY.
FOR HIGHS WEDNESDAY...USED A BLEND OF MIXING DOWN FROM 825 HPA
ACROSS THE INTERIOR...950 HPA NEAR THE COAST...MAV/MET GUIDANCE
AND NAM 2-METER TEMPERATURES. THE RESULT IS HIGHS FORECAST TO BE 5-10
DEGREES ABOVE NORMAL. HOWEVER...IF CONVECTION IS NOT
INITIATED...THEN THERE WILL BE LESS CLOUD COVER THAN
FORECAST...AND TEMPERATURES COULD END UP CLOSE TO TODAY/S READINGS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MODELS IN DECENT AGREEMENT WITH THE REGION ON THE SOUTHERN EDGE OF A
BROAD GREAT LAKES/ONTARIO/QUEBEC TROUGH TO START THE PERIOD. THE
MAIN SHORTWAVE ENERGY FLOWING THROUGH THIS TROUGH AND RESULTANT
SURFACE LOWS WILL REMAIN WELL TO THE NORTH. THE IMPACT FOR THE LOCAL
AREA WILL BE A FEW FRONTAL PASSAGES. THE FIRST WILL PUSH SOUTH AND
EAST BY THU MORNING MORNING AND WITH BEST FORCING TO THE NORTH AND
INSTABILITY WANING DURING THE EVENING HOURS ON WED...NOT EXPECTING
MUCH ACTIVITY TO CONTINUE OVERNIGHT.
AT THE SAME TIME...NHC FORECASTS TRACK TROPICAL CYCLONE BERYL TO
PASS WELL TO THE SOUTH OF THE REGION WED NIGHT INTO THU. REFER TO
THE NATIONAL HURRICANE CENTER FOR OFFICIAL TRACK AND INTENSITY
FORECASTS. THIS SHOULD MAINLY PRESENT THE REGION WITH A SUNNY AND
WARM DAY WITH GUSTY NW FLOW ON THU BETWEEN HIGH PRESSURE OVER THE
GREAT LAKES AND BERYL.
SHORTWAVE RIDGING BUILDS IN FOR FRI...WITH SEASONABLE CONDITIONS.
HIGH CLOUDS WILL INCREASE AS THE NEXT SYSTEM APPROACHES.
THEN MODELS IN GENERAL AGREEMENT WITH A PHASING OF PAC AND SOUTHERN
STREAM ENERGY OVER THE MIDWEST...RESULTING IN A CLOSED UPPER LOW OF
THE MID MISSISSIPPI VALLEY BY WEEKS END. MODELS DIVERGE IN EXACT
TRACK OF THIS UPPER LOW...WHICH HAS IMPLICATIONS ON TIMING OF THE
RESULTANT FRONTAL SYSTEMS IMPACT ON THE REGION. ONE THING THAT IS
CONSISTENT IN MEDIUM RANGE MODELS IS THAT THE TIMING OF PRECIP
APPEARS TO HAVE SLOWED OVER THE LAST FEW RUNS...SO KEPT FRI DRY. GFS
IS MUCH SLOWER THAN EC WITH MOST OF THE RAIN FALLING ON SAT.
INSTABILITY EXTREMELY LIMITED FRI NIGHT SO HAVE EXCLUDED
THUNDER...BUT WOULD NOT BE SURPRISED IF THERE WERE A FEW RUMBLES
FROM MARGINAL ELEVATED INSTABILITY. CONVECTIVE POTENTIAL INCREASES
SAT AFTERNOON INTO SUNDAY AS BROAD TROUGH WORKS THROUGH THE REGION.
RIDGING SURFACE/ALOFT BUILD BACK IN ON MONDAY.
TEMPERATURES WILL BE AT TO SLIGHTLY ABOVE NORMAL LEVELS THROUGH THE
PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT REMAINS NEARLY STATIONARY NORTH OF THE TERMINALS. A
COLD FRONT WILL APPROACHES FROM THE WEST LATER TODAY AND THIS
EVENING...AND WILL MOVE ACROSS THE AREA TONIGHT.
STRATUS/FOG REMAINS ACROSS SE CT AND ERN LONG ISLAND. KGON AND KBDR
ARE EXPECTED TO OBSERVE LIFR OR IFR AT BEST OVERNIGHT. THERE IS A
CHANCE ISP COULD FALL TO MVFR. OTHERWISE...MAINLY VFR ELSEWHERE
THROUGH MUCH OF TONIGHT. FOG DEVELOPMENT IS POSSIBLE...AND CANNOT
RULE OUT MVFR OR IFR VSBYS. NYC METRO SHOULD GENERALLY REMAIN VFR.
ANY FOG/STRATUS DISSIPATE BY 14Z. GENERALLY VFR TODAY. THUNDERSTORMS
ARE A POSSIBILITY DURING THE MID TO LATE AFTERNOON HOURS.
CHANCE OF RAIN SHOWERS INCREASES FROM WEST TO EAST TUESDAY NIGHT
AS A COLD FRONT AND UPPER LEVEL TROUGH APPROACH FROM THE WEST.
WILL MENTION JUST SHRA FOR NOW...HOWEVER THREAT OF THUNDER WILL
CONTINUE...BUT STILL TOO FAR OUT TO MENTION ANY TIMING IN THE TAFS.
LIGHT WINDS THIS MORNING. AFTER 14Z...COASTAL TERMINALS WILL
EXPERIENCE SOUTHEAST WINDS...WHEREAS WESTERN TERMINALS REMAIN SOUTH OR
SOUTHWEST. THE WINDS INCREASE TO 10 TO 15 KTS...ESPECIALLY DURING
THE AFTERNOON.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
TIMING OF ANY CONVECTION.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
TIMING OF ANY CONVECTION.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
TIMING OF ANY CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
TIMING OF ANY CONVECTION.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
TIMING OF ANY CONVECTION.
KISP FCSTER COMMENTS: CHANCE OF MVFR OR IFR VSBYS THIS MORNING
WITH ANY FOG DEVELOPMENT. AMENDMENTS POSSIBLE LATE THIS AFTERNOON
FOR TIMING OF ANY CONVECTION.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.TUE NIGHT...SHOWERS AND TSTMS LIKELY AS A COLD FRONT MOVES THROUGH.
.WED...IMPROVEMENT TO VFR.
.WED NIGHT-FRI MORNING...VFR.
.FRI AFTERNOON-SAT...MVFR OR LOWER POSSIBLE IN SHOWERS/TSTMS.
&&
.MARINE...
AREAS OF DENSE FOG REDUCING VISIBILITIES BELOW 1 NM SHOULD
CONTINUE INTO MID MORNING ACROSS EASTERN LONG ISLAND SOUND AND THE
EASTERN BAYS OF LONG ISLAND...SO HAVE CONTINUED THE DENSE FOG
ADVISORY THERE THROUGH 10 AM.
WAVEWATCH HAS BEEN RUNNING 1-2 FT HIGH...SO HAVE DELAYED THE ONSET
OF 5 FT SEAS TO TONIGHT. BEFORE THEN...THE SEABREEZE THIS
AFTERNOON SHOULD BRING GUSTS TO AROUND 20 KT...WITH OCCASIONAL
GUSTS TO 25 KT IN THE NY BIGHT. GUSTS SHOULD LINGER INTO THE
EVENING ON ALL WATERS. COASTAL OCEAN WATERS COULD SEE GUSTS TO
AROUND 20 KT CONTINUE THROUGH THE NIGHT...IN RESPONSE TO A PASSING
25-35 KT LOW LEVEL JET. WITH A RELATIVELY STRONG MARINE LAYER
THOUGH...THERE IS SOME UNCERTAINTY AS TO HOW MUCH OF THIS WILL
ACTUALLY MIX DOWN. WINDS WEDNESDAY WILL BE 10 KT OR LESS...HOWEVER
IT APPEARS THAT 5 FT SEAS SHOULD CONTINUE ON THE COASTAL OCEAN WATERS.
FOR NOW HAVE HELD ON A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS ON
THE COASTAL OCEAN WATERS. GIVEN THE PERSISTENT OVER ESTIMATING OF
WAVE HEIGHTS BY WAVEWATCH - INCLUDING IN A SIMILAR SITUATION A
COUPLE OF WEEKS AGO WHERE IT CALLED FOR 5-6 FT SEAS ON THEY NEVER
GOT ABOVE 4 FT...DO NOT HAVE THE CONFIDENCE NEEDED TO PUT ONE UP.
WINDS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS THROUGH THE
PERIOD. SEAS ON THE OCEAN WILL APPROACH 5 FT THU NIGHT/FRI AS THE
REMNANT LOW OF BERYL PASSES WELL TO THE S AND E. UNCERTAIN WHETHER A
LONG PERIOD SWELL WOULD BE ABLE TO DEVELOP PUSHING SEAS ABOVE
CRITERIA SO HAVE KEPT THEM JUST BELOW FOR NOW. THE PRESSURE GRADIENT
WILL TIGHTEN FRI NIGHT BUT AN INVERSION OVER THE WATERS IS EXPECTED
TO KEEP HIGHER WINDS FROM MIXING DOWN. HOWEVER...15-20 KT SUSTAINED
SLY WINDS THROUGH SAT WILL LIKELY CAUSE SEAS ON THE OCEAN TO BUILD
TO SCA LEVELS SAT AND SUN.
&&
.HYDROLOGY...
CURRENTLY FORECASTING A BASIN AVERAGE OF AROUND 1/4-1/2 INCH OF
RAINFALL FROM THIS MORNING THROUGH WEDNESDAY. HOWEVER...WITH
PRECIPITABLE WATERS FORECAST OF 1.5-1.75 INCHES...LOCALLY HEAVY
DOWNPOURS ARE POSSIBLE WITH ANY STRONGER CONVECTION...WITH
LOCALIZED AMOUNTS OF AN INCH+ POSSIBLE. AREAS EXPERIENCING LOCALLY
HEAVY RAINFALL LIKELY COULD EXPERIENCE MINOR POOR DRAINAGE/URBAN
FLOODING AS A RESULT. STORM MOTION IS FORECAST TO BE 15-20 KT...SO
SLOW MOVING STORMS SHOULD NOT BE AN ISSUE. HOWEVER...WITH THE PRE-
FRONTAL TROUGH FORECAST TO STALL OUT OVER THE AREA TONIGHT...THERE
IS SOME POTENTIAL FOR TRAINING ALONG THIS BOUNDARY. IF STRONGER
STORMS DO TRAIN ALONG THIS BOUNDARY...THEN MORE SIGNIFICANT
FLOODING IS POSSIBLE.
THE NEXT CHANCE FOR SIGNIFICANT RAINFALL IS FRI NIGHT INTO SAT. 1/2
TO 1 INCH OF BASIN AVERAGE QPF IS EXPECTED AT THIS TIME. LOCALLY
HIGHER AMOUNTS ARE POSSIBLE IN THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340.
&&
$$
SYNOPSIS...24/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...24
AVIATION...BC
MARINE...24/MALOIT/NV
HYDROLOGY...24/MALOIT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
411 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A COASTAL FRONT OVER COASTAL CONNECTICUT...WILL LIFT NORTH THIS
MORNING...AND MERGE WITH THE WARM FRONT TO OUR NORTH. A PRE-
FRONTAL TROUGH BEGINS TO PUSH INTO WESTERN PORTIONS OF THE TRI-
STATE THIS AFTERNOON...THEN STALLS OVER THE AREA FROM TONIGHT INTO
WEDNESDAY...WITH A COLD FRONT MOVING INTO WESTERN PARTS OF THE
TRI-STATE WEDNESDAY AFTERNOON...AND PUSHING SOUTH AND EAST OF THE
AREA BY THURSDAY MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE
AREA THROUGH FRIDAY. LOW PRESSURE WILL TRACK FROM THE OHIO VALLEY
THROUGH SOUTHEAST CANADA FRIDAY THROUGH SUNDAY SENDING A FRONTAL
SYSTEM THROUGH THE AREA ON SATURDAY. WEAK HIGH PRESSURE RETURNS
FOR MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COASTAL FRONT CURRENTLY STRETCHES FROM THE SW CT COAST BACK SE
INTO THE TWIN FORKS OF LONG ISLAND...AREAS OF FOG WILL PERSIST TO
THE N OF THIS FRONT UNTIL A COUPLE OF HOURS AFTER SUNRISE...WHEN A
COMBINATION OF SOLAR HEATING AND THE FRONT LIFTING N ALLOW FOR THE
FOG TO DISSIPATE. THERE ARE SOME PATCHES OF DENSE FOG IN THIS
AREA...SO WILL GO AHEAD AND EXPAND THE SPS FOR LOCALLY DENSE FOG
TO INCLUDE ALL OF SW CT AND COASTAL SE CT. WILL NOT INCLUDE
EASTERN SUFFOLK COUNTY FOR NOW...AS THE AREA IMPACTED IS VERY SMALL.
ALL MODELS OTHER THAN THE HRRR AND ECMWF ARE OVER DOING THE EXTENT
OF SHRA/TSTM EARLY THIS MORNING...SO HAVE GONE WITH THE OUTLIERS
IN THIS CASE...AND HAVE GONE WITH A DRY FORECAST INTO MID MORNING.
AN APPROACHING PRE-FRONTAL TROUGH WILL SERVE AS THE TRIGGER FOR
MAINLY ISOLD-SCT SHRA/TSRA FROM LATE THIS MORNING INTO THIS
AFTERNOON...WITH SHRA/TSRA BECOMING LIKELY N AND W OF NYC BY LATE
AFTERNOON.
THE SEVERE POTENTIAL TODAY IS VERY LOW...DUE TO RELATIVELY LOW
VALUES OF SHEAR...ONLY 15-25 KT OF 0-6 KM BULK SHEAR...DOWNDRAFT
CAPES OF 800 J/KG OR LESS AND LOW LEVEL JET OF 15-25 KT OVER THE
INTERIOR - MINIMIZING THE SEVERE WIND THREAT...AND WET-BULB ZERO
HEIGHTS AROUND 11000 FT MINIMIZING THE SEVERE HAIL THREAT. THE LOW
VALUES OF SHEAR ALSO HELP KEEP BULK RICHARDSON VALUES GENERALLY
ABOVE 50...AND IN SOME CASES WELL ABOVE 50...PROMOTING MAINLY
PULSE STORMS. HOWEVER...WITH FORECAST CAPES OF 1500-2500 J/KG AND
LIFTED INDICES OF -4 TO -8 ACROSS THE INTERIOR...ISOLATED PULSE
SEVERE STORMS CANNOT BE COMPLETELY RULED OUT...WITH THE BEST
CHANCE MAINLY TO THE N AND W OF NYC. HAVE PUT THE POTENTIAL FOR
GUSTY WINDS IN FOR AREAS WITH LIKELY POPS THIS AFTERNOON AS A RESULT.
FOR HIGHS TODAY...USED A BLEND OF MIXING DOWN FROM 975 HPA NEAR
THE COAST...850 HPA INLAND...WITH MET/MAV GUIDANCE AND NAM 2-METER
TEMPERATURES. FORECASTING VALUES 10-15 DEGREES ABOVE NORMAL - WITH
A FEW AREAS IN THE NYC METRO GETTING TO OR RIGHT ABOVE 90. WITH
DEWPOINTS FORECAST TO THE UPPER 60S...EXPECT HEAT INDICES
GENERALLY IN THE LOWER 90S ACROSS THE INTERIOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
THE PRE-FRONTAL TROUGH WILL STALL OUT ACROSS THE FORECAST AREA
TONIGHT...THIS COUPLED WITH THE PASSAGE OF A 700 HPA SHORTWAVE
WARRANTS LIKELY POPS FOR SHRA/TSRA ACROSS THE REGION TONIGHT. BULK
SHEAR INCREASE TONIGHT...FORECAST TO 35-45 KT OVERNIGHT...WITH
BULK RICHARDSON NUMBERS FORECAST TO DECREASE TO 20-40 LATE. AS A
RESULT...COULD SEE SOME ORGANIZED STORMS LATE TONIGHT...MAINLY
OVER EASTERN ZONES BEFORE THE 700 HPA SHORTWAVE EXITS. ALSO WITH
LIFTED INDICES AROUND -4 OVERNIGHT...AN ISOLATED SEVERE STORM
CANNOT BE RULED OUT AS WELL. FOR LOWS USED A BLEND OF MET
GUIDANCE...BIAS CORRECTED MAV GUIDANCE...AND NAM 2-METER
TEMPERATURES. THIS YIELDED LOWS 10-15 DEGREES ABOVE NORMAL.
A COLD FRONT MOVING IN FROM THE GREAT LAKES CATCHES UP TO/MERGES
WITH THE PRE-FRONTAL TROUGH OVER WESTERN ZONES BY WEDNESDAY
AFTERNOON. AS A RESULT HAVE A CHANCE FOR SHRA/TSTM ALONG AND AHEAD
OF IT. WITH BULK SHEAR OF 35-45 KT...1000-1500 J/KG OF
CAPE...AROUND 1000 J/KG OF DOWNDRAFT CAPE...AND BEING IN THE RIGHT
REAR QUADRANT OF A 85-90 KT 300 HPA JET...DO HAVE A BETTER
CONDITIONAL SEVERE THREAT THAN TODAY...WITH BULK RICHARDSON
NUMBERS GENERALLY FROM 20-40 - SUGGESTING A POTENTIAL FOR MULTI-
CELLULAR CLUSTERS AND POSSIBLE SUPER-CELLS. HOWEVER...WE ARE
FORECAST TO HAVE A LOW- MID LEVEL CAP...THAT MIGHT NOT HAVE ENOUGH
FORCING TO OVERCOME...AND THUS COULD REMAIN DRY.
FOR HIGHS WEDNESDAY...USED A BLEND OF MIXING DOWN FROM 825 HPA
ACROSS THE INTERIOR...950 HPA NEAR THE COAST...MAV/MET GUIDANCE
AND NAM 2-METER TEMPERATURES. THE RESULT IS HIGHS FORECAST TO BE 5-10
DEGREES ABOVE NORMAL. HOWEVER...IF CONVECTION IS NOT
INITIATED...THEN THERE WILL BE LESS CLOUD COVER THAN
FORECAST...AND TEMPERATURES COULD END UP CLOSE TO TODAY/S READINGS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MODELS IN DECENT AGREEMENT WITH THE REGION ON THE SOUTHERN EDGE OF A
BROAD GREAT LAKES/ONTARIO/QUEBEC TROUGH TO START THE PERIOD. THE
MAIN SHORTWAVE ENERGY FLOWING THROUGH THIS TROUGH AND RESULTANT
SURFACE LOWS WILL REMAIN WELL TO THE NORTH. THE IMPACT FOR THE LOCAL
AREA WILL BE A FEW FRONTAL PASSAGES. THE FIRST WILL PUSH SOUTH AND
EAST BY THU MORNING MORNING AND WITH BEST FORCING TO THE NORTH AND
INSTABILITY WANING DURING THE EVENING HOURS ON WED...NOT EXPECTING
MUCH ACTIVITY TO CONTINUE OVERNIGHT.
AT THE SAME TIME...NHC FORECASTS TRACK TROPICAL CYCLONE BERYL TO
PASS WELL TO THE SOUTH OF THE REGION WED NIGHT INTO THU. REFER TO
THE NATIONAL HURRICANE CENTER FOR OFFICIAL TRACK AND INTENSITY
FORECASTS. THIS SHOULD MAINLY PRESENT THE REGION WITH A SUNNY AND
WARM DAY WITH GUSTY NW FLOW ON THU BETWEEN HIGH PRESSURE OVER THE
GREAT LAKES AND BERYL.
SHORTWAVE RIDGING BUILDS IN FOR FRI...WITH SEASONABLE CONDITIONS.
HIGH CLOUDS WILL INCREASE AS THE NEXT SYSTEM APPROACHES.
THEN MODELS IN GENERAL AGREEMENT WITH A PHASING OF PAC AND SOUTHERN
STREAM ENERGY OVER THE MIDWEST...RESULTING IN A CLOSED UPPER LOW OF
THE MID MISSISSIPPI VALLEY BY WEEKS END. MODELS DIVERGE IN EXACT
TRACK OF THIS UPPER LOW...WHICH HAS IMPLICATIONS ON TIMING OF THE
RESULTANT FRONTAL SYSTEMS IMPACT ON THE REGION. ONE THING THAT IS
CONSISTENT IN MEDIUM RANGE MODELS IS THAT THE TIMING OF PRECIP
APPEARS TO HAVE SLOWED OVER THE LAST FEW RUNS...SO KEPT FRI DRY. GFS
IS MUCH SLOWER THAN EC WITH MOST OF THE RAIN FALLING ON SAT.
INSTABILITY EXTREMELY LIMITED FRI NIGHT SO HAVE EXCLUDED
THUNDER...BUT WOULD NOT BE SURPRISED IF THERE WERE A FEW RUMBLES
FROM MARGINAL ELEVATED INSTABILITY. CONVECTIVE POTENTIAL INCREASES
SAT AFTERNOON INTO SUNDAY AS BROAD TROUGH WORKS THROUGH THE REGION.
RIDGING SURFACE/ALOFT BUILD BACK IN ON MONDAY.
TEMPERATURES WILL BE AT TO SLIGHTLY ABOVE NORMAL LEVELS THROUGH THE
PERIOD.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL REMAIN NEARLY STATIONARY JUST TO THE NORTH
TONIGHT. A COLD FRONT APPROACHES FROM THE WEST LATE TODAY.
STRATUS REMAINS ACROSS SE CT AND ERN LONG ISLAND. HOW FAR WEST THE
STRATUS MOVES REMAINS THE FORECAST CHALLENGE FOR THE OVERNIGHT. KGON
CONTINUES TO OBSERVE LIFR OR IFR AT BEST OVERNIGHT...WITH PERHAPS
KISP GOING DOWN TO IFR OR WORSE.
OTHERWISE...MAINLY VFR ELSEWHERE THROUGH MUCH OF TONIGHT. FOG
DEVELOPMENT IS POSSIBLE AT MANY TERMINALS. CANNOT RULE OUT MVFR OR
IFR VSBYS. NYC METRO SHOULD GENERALLY REMAIN VFR.
FOR TUESDAY...THUNDERSTORMS ARE A POSSIBILITY DURING THE MID TO LATE
AFTERNOON HOURS. OTHERWISE VFR. CHANCE OF RAIN SHOWERS INCREASES
FROM WEST TO EAST TUESDAY NIGHT AS A COLD FRONT AND UPPER LEVEL TROUGH
APPROACH FROM THE WEST.
WINDS WILL LIGHTEN TONIGHT. COASTAL TERMINALS MAY REMAIN
SOUTHEAST...WHEREAS WESTERN TERMINALS REMAIN SOUTH OR SOUTHWEST.
SOUTHERLY WINDS INCREASE TO 10 TO 15 KTS TUESDAY...ESPECIALLY
DURING THE AFTERNOON.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.TUE NIGHT...SHOWERS AND TSTMS LIKELY AS A COLD FRONT MOVES THROUGH.
.WED...IMPROVEMENT TO VFR.
.WED NIGHT-FRI MORNING...VFR.
.FRI AFTERNOON-SAT...MVFR OR LOWER POSSIBLE IN SHOWERS/TSTMS.
&&
.MARINE...
AREAS OF DENSE FOG REDUCING VISIBILITIES BELOW 1 NM SHOULD
CONTINUE INTO MID MORNING ACROSS EASTERN LONG ISLAND SOUND AND THE
EASTERN BAYS OF LONG ISLAND...SO HAVE CONTINUED THE DENSE FOG
ADVISORY THERE THROUGH 10 AM.
WAVEWATCH HAS BEEN RUNNING 1-2 FT HIGH...SO HAVE DELAYED THE ONSET
OF 5 FT SEAS TO TONIGHT. BEFORE THEN...THE SEABREEZE THIS
AFTERNOON SHOULD BRING GUSTS TO AROUND 20 KT...WITH OCCASIONAL
GUSTS TO 25 KT IN THE NY BIGHT. GUSTS SHOULD LINGER INTO THE
EVENING ON ALL WATERS. COASTAL OCEAN WATERS COULD SEE GUSTS TO
AROUND 20 KT CONTINUE THROUGH THE NIGHT...IN RESPONSE TO A PASSING
25-35 KT LOW LEVEL JET. WITH A RELATIVELY STRONG MARINE LAYER
THOUGH...THERE IS SOME UNCERTAINTY AS TO HOW MUCH OF THIS WILL
ACTUALLY MIX DOWN. WINDS WEDNESDAY WILL BE 10 KT OR LESS...HOWEVER
IT APPEARS THAT 5 FT SEAS SHOULD CONTINUE ON THE COASTAL OCEAN WATERS.
FOR NOW HAVE HELD ON A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS ON
THE COASTAL OCEAN WATERS. GIVEN THE PERSISTENT OVER ESTIMATING OF
WAVE HEIGHTS BY WAVEWATCH - INCLUDING IN A SIMILAR SITUATION A
COUPLE OF WEEKS AGO WHERE IT CALLED FOR 5-6 FT SEAS ON THEY NEVER
GOT ABOVE 4 FT...DO NOT HAVE THE CONFIDENCE NEEDED TO PUT ONE UP.
WINDS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS THROUGH THE
PERIOD. SEAS ON THE OCEAN WILL APPROACH 5 FT THU NIGHT/FRI AS THE
REMNANT LOW OF BERYL PASSES WELL TO THE S AND E. UNCERTAIN WHETHER A
LONG PERIOD SWELL WOULD BE ABLE TO DEVELOP PUSHING SEAS ABOVE
CRITERIA SO HAVE KEPT THEM JUST BELOW FOR NOW. THE PRESSURE GRADIENT
WILL TIGHTEN FRI NIGHT BUT AN INVERSION OVER THE WATERS IS EXPECTED
TO KEEP HIGHER WINDS FROM MIXING DOWN. HOWEVER...15-20 KT SUSTAINED
SLY WINDS THROUGH SAT WILL LIKELY CAUSE SEAS ON THE OCEAN TO BUILD
TO SCA LEVELS SAT AND SUN.
&&
.HYDROLOGY...
CURRENTLY FORECASTING A BASIN AVERAGE OF AROUND 1/4-1/2 INCH OF
RAINFALL FROM THIS MORNING THROUGH WEDNESDAY. HOWEVER...WITH
PRECIPITABLE WATERS FORECAST OF 1.5-1.75 INCHES...LOCALLY HEAVY
DOWNPOURS ARE POSSIBLE WITH ANY STRONGER CONVECTION...WITH
LOCALIZED AMOUNTS OF AN INCH+ POSSIBLE. AREAS EXPERIENCING LOCALLY
HEAVY RAINFALL LIKELY COULD EXPERIENCE MINOR POOR DRAINAGE/URBAN
FLOODING AS A RESULT. STORM MOTION IS FORECAST TO BE 15-20 KT...SO
SLOW MOVING STORMS SHOULD NOT BE AN ISSUE. HOWEVER...WITH THE PRE-
FRONTAL TROUGH FORECAST TO STALL OUT OVER THE AREA TONIGHT...THERE
IS SOME POTENTIAL FOR TRAINING ALONG THIS BOUNDARY. IF STRONGER
STORMS DO TRAIN ALONG THIS BOUNDARY...THEN MORE SIGNIFICANT
FLOODING IS POSSIBLE.
THE NEXT CHANCE FOR SIGNIFICANT RAINFALL IS FRI NIGHT INTO SAT. 1/2
TO 1 INCH OF BASIN AVERAGE QPF IS EXPECTED AT THIS TIME. LOCALLY
HIGHER AMOUNTS ARE POSSIBLE IN THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340.
&&
$$
SYNOPSIS...24/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...24
AVIATION...BC/PW
MARINE...24/MALOIT/NV
HYDROLOGY...24/MALOIT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1233 AM EDT TUE MAY 29 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE PRODUCING TYPICAL SUMMER LIKE CONDITIONS WILL
GIVE WAY TO A COLD FRONTAL PASSAGE WEDNESDAY. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT THURSDAY. LOW PRESSURE IN THE OHIO VALLEY
FRIDAY WILL INTENSIFY AS IT MOVES TO NEW ENGLAND DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE HRRR HAS CAUGHT UP TO THE LACK OF CONVECTION IN OUR CWA AND IS
PRETTY GOOD WITH SOME OF THE PERIPHERAL CONVECTION OCCURRING THIS
EVENING. BASED ON ITS LATEST RUN THE NY TSRAS SHOULD BYPASS US TO
THE EAST AND THE WRN PA CONVECTION SHOULD DISSIPATE BEFORE
ARRIVING. OTHERWISE BASED ON THE CURRENT DEW POINTS, IT WILL BE A
WARM NIGHT AND NO BIG CHANGES HAVE BEEN MADE.
WARM AND HUMID CONDITIONS WILL PREVAIL TONIGHT AS WE REMAIN UNDER
THE INFLUENCE OF A LARGE AREA OF HIGH PRESSURE OFF THE EAST COAST.
LIGHT SOUTHWEST WINDS WILL BECOME ALMOST CALM IN OUR SHELTERED
AREAS. ONCE AGAIN THERE COULD BE SOME PATCHIER FOG AND STRATUS.
TEMPERATURES WILL ONLY DROP INTO THE MID AND UPPER 60S IN MANY
AREAS WITH THE URBANIZED LOCATIONS REMAINING AT OR SLIGHTLY ABOVE
70. WITH HUMIDITY VALUES REMAINING HIGH AND VERY LITTLE WIND TO
STIR THE AIR, THE EXCESSIVE HEAT WARNING WILL REMAIN IN PLACE,
ESPECIALLY SINCE THIS IS THE FIRST EVENT OF THE SEASON.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
SHORTLY AFTER SUNRISE, SOUTHWEST WINDS WILL PICK UP ONCE AGAIN
AND ANOTHER HOT HUMID DAY IS IN STORE FOR MANY AREAS. HIGH
TEMPERATURES WILL CLIMB TO AROUND 90 ONCE AGAIN WITH HEAT INDICES
IN THE LOWER TO MID 90S. THE EXCESSIVE HEAT WARNING WILL REMAIN
IN EFFECT THROUGH THE DAY. AS THE COLD FRONT TO OUR NORTHWEST
APPROACHES, THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE
FROM NORTHWEST TO SOUTHEAST. SOME OF THE STORMS COULD APPROACH
SEVERE LEVELS AND SPC DOES HAVE OUR NORTHWEST ZONES UNDER A SLIGHT
RISK FOR SEVERE WEATHER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE MAIN CONCERNS FOR THIS FORECAST PERIOD CONTINUE TO BE THE
HEAT FOR TUESDAY...AND POTENTIAL FOR FLASH FLOODING LATE TUESDAY
AFTERNOON INTO TUESDAY NIGHT. THE SYSTEM FOR THE END OF THE WEEK
AND THE EARLY PART OF THE WEEKEND STILL HAS CONSIDERABLE MODEL
SPREAD...BUT THERE IS INDICATION THAT A PERIOD OF HEAVY RAIN IS
POSSIBLE.
500MB AND SFC TEMPS: TROUGHING EVOLVES IN THE EASTERN USA THIS WEEK
WITH MUCH ABOVE NORMAL LATE MAY TEMPERATURES BECOMING NORMAL OR BELOW
NORMAL THURSDAY THROUGH NEXT MONDAY.
TUESDAY NIGHT...APPROACHING CF ASSTD WITH GRTLKS SW HAS 1.8 INCH
PWAT CORRIDOR AHD OF IT AND AND DECENT RRQ OF THE 250MB 110 KT JET N
OF LK ONT. THIS IS LIKELY TO RELEASE HEAVY CONVECTION...PROBABLY
SOME SVR TO START THE EVENING IN E PA AND NNJ WITH TT NEAR 48 AND
MARGINAL BUT INCREASING 0-6KM BULK SHEAR. FF RISK IS DISCUSSED
BRIEFLY IN THE HYDRO SECTION.
WEDNESDAY...REMAINING SHOWERS/ISO TSTMS SHOULD BE HEADING SEAWARD
AND THEN A DRYING OUT ALOFT AS GTLKS SW LIFTS NEWD AND PERMITS A
GENERAL WLY FLOW ALOFT DURING THE DAY. BL WIND FIELDS LIGHT SO
LOWERING DEWPOINTS MAY TAKE A WHILE AND THINK THAT OUR DEWPOINT
FCST MAY NEED TO TREND UP IN FUTURE FCSTS. AFTN SEABREEZES LIKELY
ALONG THE COAST. THERE IS A CHC OF A LATE DAY/EVENING SHOWER OR
SPRINKLE IN E PA AND NW NJ BUT FOR NOW THE POPS ARE IN THE SLIGHT
CHC CAT AND NOT MENTIONED IN THE LEGACY ZONES.
ONE OTHER NOTE: LOW PROBABILITY THAT IT NUDGES 90 ON WEDNESDAY AND
IF IT DOES...AND IT REACHES 90 TOMORROW...WE WOULD THEN HAVE OUR
FIRST HEAT WAVE OF THE SEASON AT KILG AND KPHL.
THURSDAY...COMFORTABLY DRY AND VERY NICE WITH WEAK HIGH PRES AND
A GUSTY NW-N BL FLOW - PLENTY OF SUNSHINE EXPECTED.
FRIDAY-SATURDAY...UPPER MISSISSIPPI VALLEY TROUGH HEADS ENE WITH ITS
SIGNIFICANT SPRING LOW PRES SYSTEM BRINGING A SHOWERY PERIOD HERE...
POSSIBLY HEAVY RAIN WITH ISOLATED SVR FRIDAY NIGHT BUT THERE IS MODEL
SPREAD ON TIMING. AT LEAST THE UKMET HAS COME NORTH FROM ITS 00Z/28
FCST. THE ECMWF AND HPC WERE MOST PROGRESSIVE. DID BLEND IN THE
SLOWER IDEAS OF THE 12Z OP UKMET/GGEM/GFS WITH THE 14Z/28 HPC
GUIDANCE.
SUNDAY/MONDAY...OTHER THAT THE DIURNAL POSSIBILITY OF A SHOWER IN
THE AFTN/EVENING...IT SHOULD BE NICE WITH THE COOL TROUGH AXISED
N/S NEAR 70W AND NWLY FLOW HERE AS HIGH PRES IS SHUNTED ACROSS THE
SE USA.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING WITH A LIGHT SOUTHWEST
FLOW. FOR THE MOST PART...VFR CONDITIONS ARE EXPECTED THROUGH ABOUT
0900 OR 1000 UTC. AT THAT TIME...MVFR VISIBILITIES IN FOG ARE
POSSIBLE...BUT RIGHT NOW IFR CONDITIONS LOOK UNLIKELY.
AFTER 1300 UTC...VFR CONDITIONS ARE EXPECTED INTO AT LEAST MID
AFTERNOON. BY THAT TIME...SCATTERED THUNDERSTORMS COULD BE IMPINGING
ON KRDG AND KABE...AND THIS POTENTIAL HAS BEEN INCLUDED IN THE NEW
TERMINAL FORECASTS. THE THREAT ARRIVES A BIT LATER AT THE KPHI METRO
AIRPORTS (GENERALLY BETWEEN 2200 UTC AND 0200 UTC). GUSTY WINDS ARE
POSSIBLE WITH ANY THUNDERSTORMS).
FOR THE MOST PART...VFR CONDITIONS ARE EXPECTED TONIGHT...BUT THIS
COULD DEPEND IN LARGE PART ON THE COVERAGE OF SHOWERS AND
THUNDERSTORMS. SHOWERS AND THUNDERSTORMS ARE EXPECTED...AND ANY
LOCATION THAT GETS A THUNDERSTORM COULD SEE MVFR VISIBILITIES
DEVELOP IN FOG. AFTER 0600 UTC...MOST PLACES WILL PROBABLY SEE MVFR
CONDITIONS...BUT AT THIS POINT THE THREAT FOR WIDESPREAD IFR
CONDITIONS LOOKS LOW.
OUTLOOK...
WEDNESDAY...MVFR CONDITIONS ARE POSSIBLE IN THE MORNING WITH
LINGERING SHOWERS...THEN VFR CONDITIONS ARE EXPECTED. LIGHT W WIND
WITH SEA/BAY BREEZES EXPECTED KACY/KMIV. SMALL CHC LATE DAY SHOWER
IN E PA.
THURSDAY...VFR. SCT AFTN CLOUDS NEAR 5000 FT. NW-N GUSTS 15-20 KT.
FRIDAY...VFR TO START...WITH MVFR CONDITIONS POSSIBLY DEVELOPING IN
THE AFTERNOON AND EVENING WITH SHOWERS/ISOLATED OR SCT TSTMS. WIND
S-SE G20 KT LATE DAY OR AT NIGHT.
SATURDAY...ANY LINGERING MVFR CONDS IN THE MORNING SHOULD BECOME VFR
DURING THE AFTERNOON/EVENING. WIND SOUTH SHIFTING WEST WITH CFP
AND GUSTS 20-25 KTS.
&&
.MARINE...
A LARGE BERMUDA HIGH PRESSURE SYSTEM WILL BE THE PREDOMINANT
WEATHER FEATURE AT THE ONSET OF THE FORECAST PERIOD. WINDS WILL
BE S TO SW THROUGH TUESDAY. INITIALLY WINDS AND SEAS WILL BE
RATHER TRANQUIL, BUT BY LATE TUESDAY WIND GUSTS COULD BE
APPROACHING SMALL CRAFT ADVISORY CRITERIA AND WAVE HEIGHTS ON
THE OCEAN WATERS COULD BE RISING TO 5 FEET. SINCE THIS WILL NOT
OCCUR UNTIL VERY LATE TUESDAY AT THE EARLIEST, WE WILL HOLD OFF
ISSUING THE ADVISORY AT THIS TIME AND LET FUTURE SHIFTS EVALUATE
THE NEW COMPUTER GUIDANCE.
OUTLOOK...
TUE NIGHT INTO WED...SCA POTENTIAL MARGINAL...MAINLY FM BRIEFLY
STRENGTHENING SLY FETCH AHD OF SLOW MOVING COLD FRONT. NO SCA
ISSUANCE THIS SHIFT... ECMWF IS NOT AS STRONG ON SLY FLOW.
THURSDAY...PROBABLY NO HEADLINE IN NW-N SFC FLOW AHEAD OF WEAK HIGH
PRES.
FRIDAY...WHILE THERE IS MODEL SPREAD IN THE PLACEMENT OF SURFACE
SYSTEMS LATE FRIDAY...THERE IS A GOOD CHANCE OF SMALL CRAFT ADVY
CONDS LATE IN THE DAY OR AT NIGHT. TIMING CONFIDENCE IS BELOW
AVERAGE.
SATURDAY...SCA LIKELY WITH SOUTH WIND SHIFTING TO WEST ASSOCIATED
WITH CFP.
&&
.HYDROLOGY...
1 AND 3 HOUR GRIDDED FFG FLAGS ADJACENT LEHIGH BUCKS BERKS COUNTIES
IN PA UNDER 1 INCH...0.7/1.0 AND FOR PARTS OF CARBON AND MONROE
0.9/1.5 INCHES IN THE 1 AND 3 HOUR GUIDANCE!
THE MAIN FOCUS FOR POSSIBLE HYDROLOGY ISSUES IS THE TUESDAY
AFTERNOON INTO TUESDAY NIGHT PERIOD. CONVECTION SHOULD BE MORE
WIDESPREAD DURING THIS PERIOD THAN THE CONVECTION WE HAVE SEEN THE
PAST WEEK OR SO. THE LEE SIDE TROUGH WILL BE THE MAIN FOCAL POINT
FOR CONVECTION TUESDAY AFTERNOON...WHICH SHOULD SUSTAIN ITSELF
INTO TUESDAY NIGHT. INSTABILITY REMAINS IN PLACE TUESDAY
NIGHT...AHEAD OF A SLOW MOVING COLD FRONT...SO CONVECTION COULD
LAST WELL INTO TUESDAY NIGHT (AND EVEN WEDNESDAY MORNING).
THE MID LEVEL FLOW INCREASES TUESDAY INTO TUESDAY NIGHT...SO UNLIKE
THE CONVECTION OF THE PAST FEW DAYS...THE SHOWERS AND THUNDERSTORMS
SHOULD BE MOVING. IN ADDITION...BACK-BUILDING LOOKS AS THOUGH IT
SHOULD BE LESS OF A PROBLEM AS WELL. IT LOOKS LIKE THE MAIN ISSUE
WOULD BE TRAINING. PRECIPITABLE WATER VALUES NEAR 1.75 INCHES DURING
THE TUESDAY INTO TUESDAY NIGHT PERIOD DOES RAISE THE SPECTER FOR
FLASH FLOODING. RIGHT NOW...IT IS STILL TOO EARLY FOR A HEADLINE...
BUT THE POTENTIAL WILL CONTINUE TO BE MENTIONED IN THE HAZARDOUS
WEATHER OUTLOOK.
&&
.CLIMATE...
KMPO RER HAS BEEN SENT AND MAY BE UPDATED IF HIGHER RECORD IN THE
530 PM TIME FRAME.
FIRST 90 OF THE SEASON AT KILG-91 KACY-90 AND KPHL 91.
RER FOR TODAY 5/28
KABE 93 1941
KACY 93 1991
KPHL 94 1941
KILG 93 1941
KRDG 92 1977 1941 AND 1914
KMPO 85 1908
KTTN 94 1941
KGED 93 1965
HEAT INDEX HAS ALREADY EQUALED 95 AT KILG...94 KPHL AND 93 KPNE
AND 97 AT KRDG...AND 94 TO 98 ACROSS DE/E MD SHORE. THIS SUMMERTIME
EVENT WAS WELL MODELED AT LEAST AS EARLY AS LAST TUESDAY.
RECORDS FOR TUESDAY MAY 29 ARE SLIGHTLY WARMER AND SEEMINGLY OUT OF
REACH. RER SAMPLING IS KABE/KPHL 95...KILG 93-1991 AND PRIOR YEARS...
KGED 92 1955
RESURRECTING THE MONTHLY INFORMATION...
MONTHLY CLI.
KPHL CONTINUES ON TRACK FOR ITS 7TH CONSECUTIVE MONTH OF WELL ABV
NORMAL TEMPS. OCTOBER WAS THE MOST RECENT MONTH OF NEAR NORMAL WHICH
I CONSIDER TO BE WITHIN 0.5F OF NORM.
NOV 3.7
DEC 5.8
JAN 4.9
FEB 5.2
MAR 8.7
APR 1.5
MAY FOR KPHL... AS OF 8 AM TODAY-MAY 28TH...CONTINUES TO PROJECT PLUS
4.4F OR EQUIVALENT TO 68.2F WHICH WOULD RANK TOP 5 WARMEST...WELL
BELOW THE RECORD 70.8 IN 1991, AND THE 69.2 IN 2004.
POR DATES BACK TO 1874
KABE IS ON TRACK FOR 2ND WARMEST MAY.
SEP 3.4
OCT 1.3
NOV 3.9
DEC 6.1
JAN 5.5
FEB 5.9
MAR 10.7
APR 1.3
MAY AT KABE...IS PROJECTING..BASED ON THE 00Z/28 MIDNIGHT SHIFT
GRIDDED FCST INFORMATION.. PLUS 5.5F OR EQUIVALENT TO 66.1F WHICH
WOULD RANK 2ND WARMEST BEHIND THE 67.2 OF 1991, AND JUST AHEAD OF
THE 66.0 IN 1944 AND 65.9 IN 2004.
POR DATES BACK TO 1922
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...EXCESSIVE HEAT WARNING UNTIL 7 PM EDT THIS EVENING FOR
PAZ067>071.
NJ...EXCESSIVE HEAT WARNING UNTIL 7 PM EDT THIS EVENING FOR NJZ015-
017>019.
DE...EXCESSIVE HEAT WARNING UNTIL 7 PM EDT THIS EVENING FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GIGI/RPW
SHORT TERM...RPW
LONG TERM...DRAG
AVIATION...DRAG/HAYES
MARINE...DRAG/RPW
HYDROLOGY...DRAG
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MIAMI FL
231 PM EDT TUE MAY 29 2012
.SHORT TERM (TONIGHT-THURSDAY NIGHT)...
THE LATEST NUMERICAL GUIDANCE HAS INITIALIZED WELL WITH THE
CURRENT SYNOPTIC PATTERN AND GENERALLY REMAINS IN GOOD AGREEMENT
THROUGH THE SHORT-TERM PERIOD. SIMILAR TO THE PAST COUPLE OF
EVENINGS...MOST OF THE MID TO LATE AFTERNOON HEAVY SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO SETUP OVER THE EASTERN HALF OF THE
SOUTH FLORIDA PENINSULA AND BEGIN TO IMPACT THE EAST COAST AND METRO
LOCATIONS THROUGH THE EARLY EVENING HOURS. THE MAIN IMPACTS FROM THE
STRONGER STORMS THAT DEVELOP THROUGH THIS TIME WILL BE FREQUENT
LIGHTNING...LOCALIZED FLOODING...GUSTY WINDS FROM 40-55 MPH AND
SMALL HAIL. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES LINE UP
WELL WITH THIS PATTERN CONTINUING THROUGH THE MID-EVENING HOURS
BEFORE TRENDING DOWN THROUGH THE OVERNIGHT PERIOD TONIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...AS BERYL CONTINUES TO LIFT NORTHEAST
TO THE CAROLINA COAST OVER THE NEXT COUPLE OF DAYS...THE MODELS
CONTINUE TO INDICATE A SHORTWAVE TROUGH DIGGING SOUTHEAST OVER THE
REGION MAINTAINING A BROAD CYCLONIC UPPER FLOW ACROSS THE AREA. AT
THE SURFACE...THE SUBTROPICAL RIDGE AXIS WILL REMAIN JUST SOUTH OF
THE LOCAL AREA WITH SOUTHWEST FLOW CONTINUING THROUGH THE
LOWER-LEVELS. THE COMBINATION OF THE UPPER TROUGH...DAYTIME HEATING
AND SUFFICIENT SURFACED BASED INSTABILITY WILL BE ENOUGH TO TRIGGER
SCATTERED SHOWERS AND STORMS EACH DAY. WITH THE PRIMARY FLOW THROUGH
THE DEEP LAYER REMAINING OUT OF THE SW...EXPECT THE BULK OF THE
AFTERNOON CONVECTION TO BECOME CONCENTRATED OVER THE EASTERN HALF OF
THE LOCAL AREA EACH DAY.
THURSDAY AND THURSDAY NIGHT...ONE DIFFERENCE TO NOTE FOR THIS PERIOD
IS THE DEEP LAYER MOISTURE THE MODELS CONTINUE TO INDICATE SPREADING
NORTH ACROSS THE KEYS AND THE SOUTH FLORIDA PENINSULA. THIS INCREASE
IN DEEP LAYER MOISTURE COMBINED WITH THE UPPER TROUGH WILL ONLY
ENHANCE THE RAINFALL COVERAGE ACROSS THE LOCAL AREA...ESPECIALLY
THROUGH THE AFTERNOON AND EVENING PERIOD THURSDAY. MODEL PWAT VALUES
REFLECT THIS PATTERN AND GENERALLY INDICATE A NORTH TO SOUTH
GRADIENT ACROSS THE AREA OR FROM THE LAKE TO THE KEYS WITH THE
HIGHER PWAT VALUES REMAINING OVER THE SOUTHERN HALF OF THIS AREA (UP
TO 2.2 INCHES). AS A RESULT...WILL GRADUALLY BEGIN TO INCREASE THE
RAINFALL CHANCES THROUGH THIS PERIOD...ESPECIALLY OVER THESE
SOUTHERN AREAS WHERE THE BEST SOURCE OF DEEP LAYER MOISTURE WILL BE.
LONG TERM (FRIDAY-WEEKEND)...
MODELS REMAIN PERSISTENT INTO THE WEEKEND AND CONTINUE INDICATE THE
PREVIOUSLY DISCUSSED DEEP LAYER MOISTURE SPREADING FARTHER NORTH
ACROSS THE AREA. THIS INCREASING DEEP LAYER MOISTURE SPREADING NORTH
INTO THE LOCAL AREA WILL TRANSLATE TO INCREASING RAINFALL CHANCES
INTO THE WEEKEND. THE LATEST HPC 5 DAY PRECIP FORECAST INDICATES
TOTALS REACHING THE 2-3 INCH RANGE ACROSS THE SOUTHERN END OF THE
PENINSULA. AS TYPICALLY OBSERVED...LOCALLY HIGHER AMOUNTS WILL BE
POSSIBLE WHERE THE BULK OF THE ACTIVITY BECOMES CONCENTRATED.
&&
.MARINE...
LIGHT TO MODERATE SOUTH AND SOUTHWEST WINDS WILL BE EXPECTED
THROUGH THE MID-WEEK PERIOD WITH ISOLATED SHOWERS AND STORMS
REMAINING POSSIBLE EACH DAY. LATE MORNING AND AFTERNOON SEA
BREEZES WILL TRANSLATE TO CHOPPIER CONDITIONS EACH DAY...MAINLY
NEAR THE COAST.
&&
.FIRE WEATHER...
PLENTY OF MOISTURE SPREADING NORTH OVER THE LOCAL AREA WILL KEEP
RELATIVE HUMIDITY VALUES ABOVE CRITICAL RED FLAG LEVELS THROUGH
THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 89 74 88 / 20 40 20 40
FORT LAUDERDALE 76 90 76 88 / 20 40 20 50
MIAMI 75 90 75 89 / 20 40 20 50
NAPLES 74 89 74 89 / 10 20 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1137 AM EDT Tue May 29 2012
.UPDATE...
Upon further review, we made some last-minute adjustments to our
PoP forecast for this afternoon. Recent observations and RAP
forecasts indicate the 1000-700 mb mean wind will be in the 15 to
20 KT range, which would likely pin any sea breeze to the coast.
Indeed, the most recent HRRR run simulated reflectivity does not
show much sea breeze convection at all. It appears that the
convective band to our south (the rain band from tropical
depression Beryl that dumped a foot of rain in Lafayette County)
is the only significant convergence band in our region.
Significant cloud cover has kept SBCAPE values low in GA. The main
point of all this is that there may be few mesoscale boundaries
than we though earlier this morning, and the thermodynamics may
not be as favorable either. Thus we lowered our PoP and QPF
forecast.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Fournier
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1244 AM EDT Tue May 29 2012
.Mesoscale Update...
At 04z, the center-of-circulation of Tropical Depression Beryl was
over south central Brooks County in Georgia, or about 15 miles WSW
of Valdosta. Beryl has been on a westward course over the past
several hours, but is beginning to show signs of slowing this
motion. The NHC forecast calls for it to move north overnight, and
this seems like a reasonable expectation. Steadier rain, seen on
KVAX radar, has been feeding into the area on the immediate north
side of the circulation this evening, into Lanier and southern
Berrien Counties. Despite the appearance on radar reflectivity,
observed hourly rainfall has only been around several tenths of an
inch. Therefore, the threat of heavy rainfall and flooding still
seems to be greatly diminished across much of the forecast area
through the remainder of the overnight.
One area of interest is the southeast corner of our area: Taylor,
Dixie, and Lafayette Counties in the Florida Big Bend region.
Although a prominent arc of deeper convection and thunderstorms
extends from near Ocala to the offshore Buoy 42036, high-res models
have been very consistent in redeveloping some additional showers
and storms further north. There are signals that this may happen -
particularly 05-08z, or in the next few hours. There is a subtle
pressure trough evident in the latest surface observations extending
from Beryl`s circulation center to Perry, and then curling SW
towards the "C Tower" (or just offshore of Apalachicola). Indeed,
the C-Tower, Apalachicola and Keaton Beach (coastal Taylor Co.) are
all reporting winds from about 260-280 degrees, while winds at Cross
City and Buoy 42036 are from a more S-SW direction. This implies a
zone of low-level convergence roughly coincident with the pressure
trough and this could be a focus for renewed thunderstorms. The RUC
shows surface theta-e values increasing about 6-7K over the
aforementioned trio of counties, and recent SPC Mesoanalysis shows
SBCAPE recovering in the wake of the storms off to the SE.
Additionally, the RUC and local WRF show a considerable expansion of
curved low-level hodographs and an attendant increase in 0-1km shear
by 08-09z. Increasing instability in concert with increasing low
level shear could be a recipe for a marginal tornado threat with
low-topped supercells that can develop in that environment.
Finally, there is also the continued threat of heavy rainfall and
perhaps some flooding in Lafayette, Dixie, and Taylor Counties, as
previously discussed. RUC PWATs in the next few hours are forecast
to be very high (around 2.2 inches or so) with a very deep warm
cloud depth to 14,000 ft. Therefore, any storms that develop should
be efficient rainfall producers. Dual-pol radar data from KJAX has
shown recent spikes in KDP and instantaneous rain rate that would
support that theory, and dual-pol 1-hr precip estimates are now
exceeding legacy values. Areal Flood Warning remains in effect for
awhile yet, but if more excessive rain rates become the norm,
smaller and more surgical short-fused Flash Flood Warnings may
become necessary.
&&
.PREV DISCUSSION (issued at 900 PM EDT Mon May 28 2012)...
Still dealing with Tropical Depression Beryl across our CWA this
evening, which as of 5 PM EDT was still moving slowly NNW at 5 mph
and was located about 10 miles E of Valdosta. While strong and gusty
winds never really materialized across our area today, Beryl has
been quite the rainmaker, especially over the SE FL Big Bend, where
we were most concerned about flooding potential for today during
last night`s shift. In fact, additional bands of rain continue to
push SW into southern Taylor, Dixie, and Lafayette counties this
evening, with a few of the outer bands still impacting portions of
Bay and Gulf counties with brief heavy rain and gusty winds.
However, as with most inland Tropical Cyclones, we expect these
outer bands to contract back inward towards the circulation center
within a few hours after sunset, so the focus for heavy rainfall is
expected to remain across the SE Big Bend where an Areal Flood
Warning remains in effect until early Tuesday Morning. Thus far, our
heaviest measured rainfall amount has been 4.90" from a Mesonet site
in West Cooks Hammock in Lafayette County. (See the MIALSRTAE
product for details). However, the Bias Corrected MPE Radar
Estimates from the surrounding Radars (unfortunately KTLH is still
down and is not included), did show a fairly impressive band of 5.5"
to 7.0" totals in and around this area with potentially more to
come. Otherwise, current fcst looks on track and no major updates
are anticipated this evening.
AVIATION...Conditions will vary widely across the terminals through
the period with the eastern terminals of KVLD, KTLH, and KABY seeing
low cigs with occasional squalls associated with Beryl. Meanwhile,
the western terminals of KDHN and KECP will escape most of the
action with mainly VFR prevailing.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...Flood Watch through Tuesday morning for Ben Hill-Berrien-Brooks-
Colquitt-Cook-Dougherty-Grady-Irwin-Lanier-Lee-Lowndes-
Mitchell-Thomas-Tift-Turner-Worth.
FL...Areal Flood Warning until 6:15 AM EDT Tuesday morning for
Dixie, Taylor, and Lafayette counties.
Flood Watch through Tuesday morning for Coastal Dixie-Coastal
Jefferson-Coastal Taylor-Coastal Wakulla-Inland Dixie-Inland
Jefferson-Inland Taylor-Inland Wakulla-Lafayette-Leon-Madison.
GM...None.
&&
$$
Mesoscale Update...Lamers
Previous Discussion...Gould
Aviation...DVD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
340 PM EDT TUE MAY 29 2012
...CONTINUED LOCALLY HEAVY RAINFALL IN BANDS FROM REMNANTS OF BERYL...
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
CENTER OF THE REMNANTS OF BERYL HAS NOW ENTERED THE FORECAST AREA
MOVING FROM TELFAIR COUNTY INTO WHEELER. EASTERN SIDE OF THE STORM
HAS DEFINITELY BEEN THE WETTEST IN THE THIS STORMS HISTORY AND
TODAY IS NO DIFFERENT WITH FEEDER BANDS OFF THE ATLANTIC COAST
PROVIDING THE MOST CONSISTENT HEAVY RAINFALL. SHOULD SEE ACTIVITY
LOCALLY ENHANCE THROUGH THE AFTERNOON BUT INSTABILITY WILL REMAIN
MARGINAL DUE TO ENHANCED CLOUD COVER. STILL THINKING THE EASTERN
TIER OF THE FORECAST AREA COULD SEE 1 TO 2 INCHES WITH LOCALLY
HIGHER AMOUNTS WHERE CONVECTIVE BANDS SET UP THROUGH THIS EVENING.
SHEAR IS IMPRESSIVE IN THE LOW LEVELS WITH 30 TO 40 KNOTS AT
925MB...AGAIN OVER THE EASTERN SECTIONS. HAVE JUST NOT HAD THE
INSTABILITY TO TAKE ADVANTAGE OF SHEAR PROFILE THUS FAR BUT WILL
NEED TO MONITOR CELLS CLOSELY FOR POTENTIAL FOR ROTATION IN CELLS
OR ISOLATED STRONG GUSTS.
SEPARATE ARE OVER MISSISSIPPI THIS MORNING DISSIPATED FOR THE
MOST PART AS IT MOVED INTO PORTIONS OF ALABAMA. HRRR STILL KEYING
IN ON NW GEORGIA FOR POSSIBLE LATE TSRA DEVELOPMENT AND HAVE KEPT
LOW END CHANCE POPS IN THERE THROUGH THIS EVENING.
ON THE BACK SIDE OF BERYL...SIGNIFICANTLY DRIER AIR TO WORK ITS
WAY IN WITH SOUNDINGS SHOWING A PROFILE BARELY SUPPORTIVE OF CU
FORMATION IN THE AFTERNOON FROM ATL NORTHWARD. SLIGHTLY BETTER
MOISTURE OVER THE SOUTHERN TIER AND EMBEDDED SHORTWAVE DURING THE
AFTERNOON SHOULD ALLOW FOR LOW END SCT THUNDERSTORM ACTIVITY.
DEESE
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TD BERYL PULLS OUT OF THE AREA WEDNESDAY AS A FRONTAL SYSTEM SWEEPS
THROUGH THE STATE. UPPER LEVEL WESTERLY FLOW KEEPS RESIDUAL MOISTURE
OVER THE AREA THROUGH THURSDAY AHEAD OF ANOTHER FRONTAL SYSTEM
MOVING INTO THE STATE FRIDAY. WILL CONTINUE WITH SLIGHT/CHANCE POPS
THROUGH THE END OF THE WEEK. RAIN CHANCES SIGNIFICANTLY INCREASE FOR
THURSDAY AND FRIDAY AS MODELS SHOWING AN UPPER LOW AND ASSOCIATED
FRONTAL BOUNDARY PUSHING EAST OF THE PLAINS ON THURSDAY AND DRAGGING
A COLD FRONT ACROSS THE FORECAST AREA FRIDAY/FRIDAY NIGHT. EXPECT
THE GREATEST THUNDERSTORM THREAT TO BE DURING THE DAY FRIDAY...WITH
2000-2500 CAPE...40KT LOW LEVEL JET AND MODERATE DIFFLUENT FLOW
ALOFT. TOTAL RAINFALL AMOUNTS FOR THURSDAY AND FRIDAY WILL LIKELY BE
AND INCH OR LESS. ONCE THIS FRONT MOVES THROUGH...HIGH PRESSURE
BUILDS IN AND CLEAR TO PARTLY CLOUDY SKIES PREVAIL FOR THE WEEKEND
AND INTO EARLY NEXT WEEK.
01
&&
.AVIATION...
18Z UPDATE... AS HAS BEEN THE CASE FOR THE LAST FEW
DAYS...OUTER ENVELOPE OF PRECIPITATION ASSOCIATED WITH BERYL HAS
EXPANDED DURING THE DAYTIME HOURS. THIS HAS ALLOWED BANDED
PRECIPITATION TO ROTATE THROUGH THE AHN AND ATL AREA SITES WITH
JUST SHRA NOTED WITH A NOTICEABLE LACK OF TSRA. FOR THE 18Z
PACKAGE...WILL INITIALIZE WITH A SHORT TERM TEMPO FOR SHRA AND
THEN TRANSITION TO VCSH FOR THE REMAINDER OF THE EVENING. TSRA NOT
OUR OF THE QUESTION BUT CHANCES APPEAR TOO LOW TO INCLUDE IN TEMPO
AT THIS TIME. WINDS LOOK TO SHIFT FROM NNE TO NNW DURING THE
OVERNIGHT HOURS WITH MOST LIKELY TIME BETWEEN 06Z AND 09Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 92 65 90 / 60 10 10 30
ATLANTA 68 91 70 88 / 40 10 20 30
BLAIRSVILLE 62 85 61 82 / 40 20 20 40
CARTERSVILLE 65 92 64 87 / 30 10 20 50
COLUMBUS 68 94 68 92 / 30 20 20 30
GAINESVILLE 64 90 67 84 / 50 10 20 40
MACON 68 93 68 93 / 60 10 10 30
ROME 65 93 63 86 / 30 10 20 50
PEACHTREE CITY 66 91 64 87 / 40 10 20 30
VIDALIA 68 91 70 94 / 100 20 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....01
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
322 PM EDT TUE MAY 29 2012
...CONTINUED LOCALLY HEAVY RAINFALL IN BANDS FROM REMNANTS OF BERYL...
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
CENTER OF THE REMNANTS OF BERYL HAS NOW ENTERED THE FORECAST AREA
MOVING FROM TELFAIR COUNTY INTO WHEELER. EASTERN SIDE OF THE STORM
HAS DEFINITELY BEEN THE WETTEST IN THE THIS STORMS HISTORY AND
TODAY IS NO DIFFERENT WITH FEEDER BANDS OFF THE ATLANTIC COAST
PROVIDING THE MOST CONSISTENT HEAVY RAINFALL. SHOULD SEE ACTIVITY
LOCALLY ENHANCE THROUGH THE AFTERNOON BUT INSTABILITY WILL REMAIN
MARGINAL DUE TO ENHANCED CLOUD COVER. STILL THINKING THE EASTERN
TIER OF THE FORECAST AREA COULD SEE 1 TO 2 INCHES WITH LOCALLY
HIGHER AMOUNTS WHERE CONVECTIVE BANDS SET UP THROUGH THIS EVENING.
SHEAR IS IMPRESSIVE IN THE LOW LEVELS WITH 30 TO 40 KNOTS AT
925MB...AGAIN OVER THE EASTERN SECTIONS. HAVE JUST NOT HAD THE
INSTABILITY TO TAKE ADVANTAGE OF SHEAR PROFILE THUS FAR BUT WILL
NEED TO MONITOR CELLS CLOSELY FOR POTENTIAL FOR ROTATION IN CELLS
OR ISOLATED STRONG GUSTS.
SEPARATE ARE OVER MISSISSIPPI THIS MORNING DISSIPATED FOR THE
MOST PART AS IT MOVED INTO PORTIONS OF ALABAMA. HRRR STILL KEYING
IN ON NW GEORGIA FOR POSSIBLE LATE TSRA DEVELOPMENT AND HAVE KEPT
LOW END CHANCE POPS IN THERE THROUGH THIS EVENING.
ON THE BACK SIDE OF BERYL...SIGNIFICANTLY DRIER AIR TO WORK ITS
WAY IN WITH SOUNDINGS SHOWING A PROFILE BARELY SUPPORTIVE OF CU
FORMATION IN THE AFTERNOON FROM ATL NORTHWARD. SLIGHTLY BETTER
MOISTURE OVER THE SOUTHERN TIER AND EMBEDDED SHORTWAVE DURING THE
AFTERNOON SHOULD ALLOW FOR LOW END SCT THUNDERSTORM ACTIVITY.
DEESE
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THERE WILL STILL BE A FEW WAVES MOVING ACROSS THE AREA IN THE
UPPER LEVEL WESTERLY FLOW SO WILL CONTINUE WITH SLIGHT/CHANCE
THUNDER THROUGH THE END OF THE WEEK. RAIN CHANCES SIGNIFICANTLY
INCREASE FOR THURSDAY AND FRIDAY AS MODELS SHOWING AN UPPER LOW
AND ASSOCIATED FRONTAL BOUNDARY PUSHING EAST OF THE PLAINS ON
THURSDAY AND DRAGGING A COLD FRONT ACROSS THE FORECAST AREA FRIDAY
NIGHT. EXPECT THE GREATER THUNDERSTORM THREAT TO BE ON FRIDAY
AHEAD OF THE APPROACHING FRONT...WITH 2000-2500 CAPE...40KT LOW
LEVEL JET AND MODERATE DIFFLUENT FLOW ALOFT. TOTAL RAINFALL
AMOUNTS FOR THURSDAY AND FRIDAY WILL LIKELY BE LESS THAN AN INCH.
ONCE THIS FRONT MOVES THROUGH...HIGH PRESSURE BUILD IN A CLEARING
CONDITIONS PREVAIL FOR THE WEEKEND AND INTO EARLY NEXT WEEK.
01
&&
.AVIATION...
18Z UPDATE... AS HAS BEEN THE CASE FOR THE LAST FEW
DAYS...OUTER ENVELOPE OF PRECIPITATION ASSOCIATED WITH BERYL HAS
EXPANDED DURING THE DAYTIME HOURS. THIS HAS ALLOWED BANDED
PRECIPITATION TO ROTATE THROUGH THE AHN AND ATL AREA SITES WITH
JUST SHRA NOTED WITH A NOTICEABLE LACK OF TSRA. FOR THE 18Z
PACKAGE...WILL INITIALIZE WITH A SHORT TERM TEMPO FOR SHRA AND
THEN TRANSITION TO VCSH FOR THE REMAINDER OF THE EVENING. TSRA NOT
OUR OF THE QUESTION BUT CHANCES APPEAR TOO LOW TO INCLUDE IN TEMPO
AT THIS TIME. WINDS LOOK TO SHIFT FROM NNE TO NNW DURING THE
OVERNIGHT HOURS WITH MOST LIKELY TIME BETWEEN 06Z AND 09Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 92 65 90 / 60 10 10 30
ATLANTA 68 91 70 88 / 40 10 20 30
BLAIRSVILLE 62 85 61 82 / 40 20 20 40
CARTERSVILLE 65 92 64 87 / 30 10 20 50
COLUMBUS 68 94 68 92 / 30 20 20 30
GAINESVILLE 64 90 67 84 / 50 10 20 40
MACON 68 93 68 93 / 60 10 10 30
ROME 65 93 63 86 / 30 10 20 50
PEACHTREE CITY 66 91 64 87 / 40 10 20 30
VIDALIA 68 91 70 94 / 100 20 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....01
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
127 PM EDT TUE MAY 29 2012
.PREV DISCUSSION... /ISSUED 919 AM EDT TUE MAY 29 2012/
UPDATE...DID A QUICK MORNING UPDATE TO ACCOUNT FOR THE NORTHERN
FLANK OF BERYL REALLY STARTING TO FILL IN. UPDATED POP GRIDS TO
CATEGORICAL FOR THE SOUTHEAST PORTION OF THE FORECAST AREA. ALSO
EXTENDED HEAVY RAINFALL POTENTIAL NORTHWARD TO THE AHN AREA WHERE
WE WILL CONTINUE TO SEE MORE CONVECTIVELY INDUCED BANDS OF
PRECIPITATION THROUGH THIS AFTERNOON. THIS DOES NOT IMPACT THE
OVERALL THINKING OF 1 TO 2 INCHES WITH ISOLATED HIGHER AMOUNTS
WHERE BANDS SET UP.
LOW LEVEL SHEAR OF 30 KTS ON EASTERN SIDE OF BERYL WILL RESULT IN
SOME STRONG GUSTS AND OR ROTATION WITHIN ANY CELLS THAT DEVELOP IN
THE RAIN BANDS. INSTABILITY WILL BE HARD TO SOME BY GIVEN
WIDESPREAD CLOUD COVER BUT RAP DOES SHOW AN AREA OF CLOSE TO 1000
J/KG DEVELOPING LATER TODAY...MORE THAN ADEQUATE IN THIS
ENVIRONMENT TO SUSTAIN STORM DEVELOPMENT.
WILL ALSO BE WATCHING AXIS TO THE WEST WHICH IS MAKING SLOW
PROGRESS INTO NORTH ALABAMA AND SHOULD NOT BE A PLAYER FOR OUR
NORTHWEST ZONES UNTIL LATER THIS EVENING INTO THE FIRST HALF OF
THE OVERNIGHT PERIOD.
PREV DISCUSSION... /ISSUED 743 AM EDT TUE MAY 29 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
TROPICAL DEPRESSION BERYL...CURRENTLY NEAR VALDOSTA... IS EXPECTED
TO DRIFT NORTH EARLY THIS MORNING... THEN NORTHEAST TO JUST WEST OF
SAVANNAH BY LATE THIS AFTERNOON OR EARLY EVENING. THIS TRACK SHOULD
HOLD THE GREATER RAINFALL AMOUNTS OVER SE GA AND MAINLY JUST EAST OF
THE FORECAST AREA...ALTHOUGH 1 TO 2 INCHES OF RAINFALL IS STILL
POSSIBLE OVER THE FAR SE PORTIONS OF THE FORECAST AREA THROUGH THIS
EVENING. EXPECT CONVECTION TO BE IN THE FORM OF MAINLY SHOWERS WITH
ONLY THE SLIGHT THREAT OF AN EMBEDDED THUNDERSTORM DURING DAYTIME
HEATING. WILL SHOW THE GREATER RAIN CHANCES EAST OF A LINE FROM
AMERICUS TO MACON TO LEXINGTON LINE WHERE SHOWERS SHOULD BE MORE
NUMEROUS AS BERYL TRACKS NORTHEASTWARD. EXPECT ISOLATED TO SCATTERED
CONVECTION ELSEWHERE. EXPECT RAIN CHANCES TO GREATLY DIMINISH
TONIGHT AS BERYL DRIFTS TO THE SOUTH CAROLINA COASTS BY EARLY
WEDNESDAY MORNING. A DRIER NW WIND FLOW IN BERYL`S WAKE WILL HELP
HOLD CONVECTIVE CHANCES TO NIL FOR MOST AREAS ON WEDNESDAY...EXCEPT
MAYBE A SLIGHT CHANCE SOUTH WHERE A WEAK SURFACE TROUGH AND
LINGERING TROPICAL MOISTURE MAY PERSIST.
OTHERWISE...HIGH TEMPS WILL BE SLIGHTLY COOLER TODAY...MAINLY IN THE
80S... ESPECIALLY CLOSER TO THE PATH OF BERYL WHERE CLOUDS AND
SHOWERS WILL BE MORE ABUNDANT. HIGHS WILL CLIMB BACK INTO THE 90S
FOR MOST AREAS ON WEDNESDAY WITH CLEARING CONDITIONS AND ADDED
SUBSIDENCE ON THE BACK SIDE OF BERYL. LEANED SLIGHTLY WARMER THAN
MAV AND MET LOWS THROUGH THE SHORT TERM.
39
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
THE MAIN FORECAST CONCERN WILL BE THUNDERSTORM CHANCES ASSOCIATED
WITH FRONTAL PASSAGE NEAR THE END OF THE WORK WEEK. AS TROPICAL
DEPRESSION BERYL LOOKS TO BE PUSHING NORTHEASTWARD OFF THE NC COAST
BY THE START OF THE LONG TERM ON WEDNESDAY NIGHT... MORE ZONAL FLOW
ALOFT WILL BRIEFLY RETURN TO THE AREA WITH A WEAK SHORTWAVE
POTENTIALLY AIDING PRECIP CHANCES THURSDAY. AN UPPER LEVEL TROUGH
LOOKS TO DIG INTO THE CENTRAL PLAINS THURSDAY WITH ASSOCIATED LEE
CYCLOGENESIS OCCURRING. THE CORRESPONDING SFC LOW IS PROGGED TO
TRACK NORTHEASTWARD TOWARD THE GREAT LAKES WITH THE ASSOCIATED WARM
FRONT LIFTING THROUGH THE FORECAST AREA ON THURSDAY AND THE COLD OR
OCCLUDED FRONT SWINGING THROUGH SOMETIME FRIDAY NIGHT INTO SATURDAY
MORNING. THE GFS AND ECMWF ARE IN GENERAL AGREEMENT WITH THE MAIN
INFLUENCING FEATURES... HOWEVER THE ECMWF DEVELOPS A STRONGER LOW
AND IS MORE PROGRESSIVE. GUIDANCE ALSO INDICATES A 35-40KT LOW LEVEL
JET ACCOMPANYING THIS SYSTEM WITH POTENTIALLY 1500-2000 J/KG OF CAPE
IN PLACE... THEREFORE ORGANIZED CONVECTION OF STRONG TO SEVERE
INTENSITY WOULD NOT BE OUT OF THE QUESTION. ALL CONSIDERED... HAVE
MAINTAINED MOSTLY CHANCE POPS AREA-WIDE WITH THE APPROACH AND
PASSAGE OF THIS SYSTEM FROM THURSDAY THROUGH OVERNIGHT FRIDAY. THE
TIMING AND STRENGTH OF THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY
IN FUTURE UPDATES.
HIGH PRESSURE WILL QUICKLY RETURN TO THE AREA FOR THE WEEKEND AND A
BROAD UPPER RIDGE LOOKS TO BUILD IN ACROSS THE EASTERN CONUS INTO
NEXT WEEK... THEREFORE WARMER AND DRIER CONDITIONS ARE ON THE
HORIZON FOR MUCH OF THE AREA STARTING THIS COMING WEEKEND. WITH
MODEL SOLUTIONS DISAGREEING SOMEWHAT ON PLACEMENT OF SFC HIGH... IT
IS TOO DIFFICULT TO TELL ATTM WHAT DIRECTION THE SFC WINDS WOULD BE
AND IF ANY OROGRAPHIC ENHANCEMENT WOULD BE OCCURRING IN THE NORTHERN
PORTION OF THE AREA. HAVE THEREFORE KEPT DRY FORECAST FROM SATURDAY
NIGHT THROUGH MONDAY WITH THIS UNCERTAINTY AND WILL INTRODUCE POPS AS
SEE FIT IF NECESSARY IN THE FUTURE.
03
HYDROLOGY...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
HPC AND MODEL FORECASTS HOLD THE MAIN AXIS OF HEAVIER RAINFALL
AMOUNTS OVER SOUTH-SE GA... WITH ONLY 1 TO 2 INCHES EXPECTED OVER
THE FAR SE AND EAST CENTRAL PORTIONS OF THE FORECAST AREA. SIX HOUR
FFG IN THIS AREA IS 4-5 INCHES... INDICATING THE SOIL SHOULD HANDLE
THESE RAINFALL AMOUNTS WITH MINIMAL FLOOD CONCERNS. HOWEVER... THE
SLOW MOVEMENT OF BERYL WOULD FAVOR TRAINING OF CELLS OVER THE SAME
AREA...SO WILL HAVE TO MONITOR THIS POTENTIAL CLOSELY TODAY. THE
AREA OF GREATEST THREAT FOR POSSIBLE TRAINING CELLS WOULD BE MAINLY
EAST OF A LINE FROM CORDELE TO DUBLIN TO LOUISVILLE.
&&
.AVIATION...
18Z UPDATE...
AS HAS BEEN THE CASE FOR THE LAST FEW DAYS...OUTER ENVELOPE OF
PRECIPITATION ASSOCIATED WITH BERYL HAS EXPANDED DURING THE
DAYTIME HOURS. THIS HAS ALLOWED BANDED PRECIPITATION TO ROTATE
THROUGH THE AHN AND ATL AREA SITES WITH JUST SHRA NOTED WITH A
NOTICEABLE LACK OF TSRA. FOR THE 18Z PACKAGE...WILL INITIALIZE WITH
A SHORT TERM TEMPO FOR SHRA AND THEN TRANSITION TO VCSH FOR THE
REMAINDER OF THE EVENING. TSRA NOT OUR OF THE QUESTION BUT CHANCES
APPEAR TOO LOW TO INCLUDE IN TEMPO AT THIS TIME. WINDS LOOK TO
SHIFT FROM NNE TO NNW DURING THE OVERNIGHT HOURS WITH MOST LIKELY
TIME BETWEEN 06Z AND 09Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 66 92 65 / 50 60 10 10
ATLANTA 85 68 91 70 / 40 40 10 20
BLAIRSVILLE 81 62 85 61 / 40 40 20 20
CARTERSVILLE 87 65 92 64 / 30 30 10 20
COLUMBUS 88 68 94 68 / 40 30 20 20
GAINESVILLE 84 64 90 67 / 40 50 10 20
MACON 84 68 93 68 / 80 60 10 10
ROME 89 65 93 63 / 40 30 10 20
PEACHTREE CITY 85 66 91 64 / 40 40 10 20
VIDALIA 82 68 91 70 / 100 100 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....01
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
919 AM EDT TUE MAY 29 2012
.UPDATE...DID A QUICK MORNING UPDATE TO ACCOUNT FOR THE NORTHERN
FLANK OF BERYL REALLY STARTING TO FILL IN. UPDATED POP GRIDS TO
CATEGORICAL FOR THE SOUTHEAST PORTION OF THE FORECAST AREA. ALSO
EXTENDED HEAVY RAINFALL POTENTIAL NORTHWARD TO THE AHN AREA WHERE
WE WILL CONTINUE TO SEE MORE CONVECTIVELY INDUCED BANDS OF
PRECIPITATION THROUGH THIS AFTERNOON. THIS DOES NOT IMPACT THE
OVERALL THINKING OF 1 TO 2 INCHES WITH ISOLATED HIGHER AMOUNTS
WHERE BANDS SET UP.
LOW LEVEL SHEAR OF 30 KTS ON EASTERN SIDE OF BERYL WILL RESULT IN
SOME STRONG GUSTS AND OR ROTATION WITHIN ANY CELLS THAT DEVELOP IN
THE RAIN BANDS. INSTABILITY WILL BE HARD TO SOME BY GIVEN
WIDESPREAD CLOUD COVER BUT RAP DOES SHOW AN AREA OF CLOSE TO 1000
J/KG DEVELOPING LATER TODAY...MORE THAN ADEQUATE IN THIS
ENVIRONMENT TO SUSTAIN STORM DEVELOPMENT.
WILL ALSO BE WATCHING AXIS TO THE WEST WHICH IS MAKING SLOW
PROGRESS INTO NORTH ALABAMA AND SHOULD NOT BE A PLAYER FOR OUR
NORTHWEST ZONES UNTIL LATER THIS EVENING INTO THE FIRST HALF OF
THE OVERNIGHT PERIOD.
&&
.PREV DISCUSSION... /ISSUED 743 AM EDT TUE MAY 29 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
TROPICAL DEPRESSION BERYL...CURRENTLY NEAR VALDOSTA... IS EXPECTED
TO DRIFT NORTH EARLY THIS MORNING... THEN NORTHEAST TO JUST WEST OF
SAVANNAH BY LATE THIS AFTERNOON OR EARLY EVENING. THIS TRACK SHOULD
HOLD THE GREATER RAINFALL AMOUNTS OVER SE GA AND MAINLY JUST EAST OF
THE FORECAST AREA...ALTHOUGH 1 TO 2 INCHES OF RAINFALL IS STILL
POSSIBLE OVER THE FAR SE PORTIONS OF THE FORECAST AREA THROUGH THIS
EVENING. EXPECT CONVECTION TO BE IN THE FORM OF MAINLY SHOWERS WITH
ONLY THE SLIGHT THREAT OF AN EMBEDDED THUNDERSTORM DURING DAYTIME
HEATING. WILL SHOW THE GREATER RAIN CHANCES EAST OF A LINE FROM
AMERICUS TO MACON TO LEXINGTON LINE WHERE SHOWERS SHOULD BE MORE
NUMEROUS AS BERYL TRACKS NORTHEASTWARD. EXPECT ISOLATED TO SCATTERED
CONVECTION ELSEWHERE. EXPECT RAIN CHANCES TO GREATLY DIMINISH
TONIGHT AS BERYL DRIFTS TO THE SOUTH CAROLINA COASTS BY EARLY
WEDNESDAY MORNING. A DRIER NW WIND FLOW IN BERYL`S WAKE WILL HELP
HOLD CONVECTIVE CHANCES TO NIL FOR MOST AREAS ON WEDNESDAY...EXCEPT
MAYBE A SLIGHT CHANCE SOUTH WHERE A WEAK SURFACE TROUGH AND
LINGERING TROPICAL MOISTURE MAY PERSIST.
OTHERWISE...HIGH TEMPS WILL BE SLIGHTLY COOLER TODAY...MAINLY IN THE
80S... ESPECIALLY CLOSER TO THE PATH OF BERYL WHERE CLOUDS AND
SHOWERS WILL BE MORE ABUNDANT. HIGHS WILL CLIMB BACK INTO THE 90S
FOR MOST AREAS ON WEDNESDAY WITH CLEARING CONDITIONS AND ADDED
SUBSIDENCE ON THE BACK SIDE OF BERYL. LEANED SLIGHTLY WARMER THAN
MAV AND MET LOWS THROUGH THE SHORT TERM.
39
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
THE MAIN FORECAST CONCERN WILL BE THUNDERSTORM CHANCES ASSOCIATED
WITH FRONTAL PASSAGE NEAR THE END OF THE WORK WEEK. AS TROPICAL
DEPRESSION BERYL LOOKS TO BE PUSHING NORTHEASTWARD OFF THE NC COAST
BY THE START OF THE LONG TERM ON WEDNESDAY NIGHT... MORE ZONAL FLOW
ALOFT WILL BRIEFLY RETURN TO THE AREA WITH A WEAK SHORTWAVE
POTENTIALLY AIDING PRECIP CHANCES THURSDAY. AN UPPER LEVEL TROUGH
LOOKS TO DIG INTO THE CENTRAL PLAINS THURSDAY WITH ASSOCIATED LEE
CYCLOGENESIS OCCURRING. THE CORRESPONDING SFC LOW IS PROGGED TO
TRACK NORTHEASTWARD TOWARD THE GREAT LAKES WITH THE ASSOCIATED WARM
FRONT LIFTING THROUGH THE FORECAST AREA ON THURSDAY AND THE COLD OR
OCCLUDED FRONT SWINGING THROUGH SOMETIME FRIDAY NIGHT INTO SATURDAY
MORNING. THE GFS AND ECMWF ARE IN GENERAL AGREEMENT WITH THE MAIN
INFLUENCING FEATURES... HOWEVER THE ECMWF DEVELOPS A STRONGER LOW
AND IS MORE PROGRESSIVE. GUIDANCE ALSO INDICATES A 35-40KT LOW LEVEL
JET ACCOMPANYING THIS SYSTEM WITH POTENTIALLY 1500-2000 J/KG OF CAPE
IN PLACE... THEREFORE ORGANIZED CONVECTION OF STRONG TO SEVERE
INTENSITY WOULD NOT BE OUT OF THE QUESTION. ALL CONSIDERED... HAVE
MAINTAINED MOSTLY CHANCE POPS AREA-WIDE WITH THE APPROACH AND
PASSAGE OF THIS SYSTEM FROM THURSDAY THROUGH OVERNIGHT FRIDAY. THE
TIMING AND STRENGTH OF THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY
IN FUTURE UPDATES.
HIGH PRESSURE WILL QUICKLY RETURN TO THE AREA FOR THE WEEKEND AND A
BROAD UPPER RIDGE LOOKS TO BUILD IN ACROSS THE EASTERN CONUS INTO
NEXT WEEK... THEREFORE WARMER AND DRIER CONDITIONS ARE ON THE
HORIZON FOR MUCH OF THE AREA STARTING THIS COMING WEEKEND. WITH
MODEL SOLUTIONS DISAGREEING SOMEWHAT ON PLACEMENT OF SFC HIGH... IT
IS TOO DIFFICULT TO TELL ATTM WHAT DIRECTION THE SFC WINDS WOULD BE
AND IF ANY OROGRAPHIC ENHANCEMENT WOULD BE OCCURRING IN THE NORTHERN
PORTION OF THE AREA. HAVE THEREFORE KEPT DRY FORECAST FROM SATURDAY
NIGHT THROUGH MONDAY WITH THIS UNCERTAINTY AND WILL INTRODUCE POPS AS
SEE FIT IF NECESSARY IN THE FUTURE.
03
HYDROLOGY...
/ISSUED AT 434 AM EDT TUE MAY 29 2012/
HPC AND MODEL FORECASTS HOLD THE MAIN AXIS OF HEAVIER RAINFALL
AMOUNTS OVER SOUTH-SE GA... WITH ONLY 1 TO 2 INCHES EXPECTED OVER
THE FAR SE AND EAST CENTRAL PORTIONS OF THE FORECAST AREA. SIX HOUR
FFG IN THIS AREA IS 4-5 INCHES... INDICATING THE SOIL SHOULD HANDLE
THESE RAINFALL AMOUNTS WITH MINIMAL FLOOD CONCERNS. HOWEVER... THE
SLOW MOVEMENT OF BERYL WOULD FAVOR TRAINING OF CELLS OVER THE SAME
AREA...SO WILL HAVE TO MONITOR THIS POTENTIAL CLOSELY TODAY. THE
AREA OF GREATEST THREAT FOR POSSIBLE TRAINING CELLS WOULD BE MAINLY
EAST OF A LINE FROM CORDELE TO DUBLIN TO LOUISVILLE.
AVIATION...
12Z UPDATE...
MVFR CIGS EXPECTED TO CONTINUE THROUGH LATE MORNING...THEN IMPROVE
TO VFR LEVELS BY 17-18Z WITH DAYTIME HEATING. RADAR SHOWS -RA SHIELD
SPREADING NORTHWARD FROM T.D. BERYL... CURRENTLY OVER SOUTH GA AND
FORECASTED TO DRIFT NNE TODAY. EXPECT SPIRAL BANDS OF HEAVIER SHRA`S
AND POSSIBLY A FEW TSRA`S TO TRAVERSE THE ATLANTA AREA TAF SITES
BETWEEN 18Z TO 00Z THIS AFTERNOON. THE CONVECTIVE THREAT WILL
DIMINISH BY 00-03Z THIS EVENING AS BERYL DRIFTS TOWARD THE SC COAST
AND AREA TAFS ARE ON THE DRIER WEST SIDE OF THE SYSTEM. GUSTY ENE
WINDS WILL SWING MORE NORTH THROUGH THE AFTERNOON AND EVENING. GUSTS
TO AROUND 18-20KTS FROM MID MORNING THROUGH THE AFTERNOON WILL END
BY 00Z. NO LOW CIG THREAT TONIGHT...BUT MAY SEE SOME PATCHY FOG
DEVELOP WITH WET GROUNDS AND CLEARING SKIES.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 66 92 65 / 50 60 10 10
ATLANTA 85 68 91 70 / 40 40 10 20
BLAIRSVILLE 81 62 85 61 / 40 40 20 20
CARTERSVILLE 87 65 92 64 / 30 30 10 20
COLUMBUS 88 68 94 68 / 40 30 20 20
GAINESVILLE 84 64 90 67 / 40 50 10 20
MACON 84 68 93 68 / 80 60 10 10
ROME 89 65 93 63 / 40 30 10 20
PEACHTREE CITY 85 66 91 64 / 40 40 10 20
VIDALIA 82 68 91 70 / 100 100 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....01
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1005 PM CDT WED MAY 30 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
//PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NE WINDS WITH THE OCNL GUST
* OVERNIGHT / EARLY AM PRECIP
* CIG/VIS TRENDS IN PRECIP
SHEA
//DISCUSSION...UPDATED 00Z...
OVERALL VFR CONDITIONS WILL CONTINUE OVERNIGHT. MVFR CIGS THAT
WERE THREATENING TO IMPACT ORD/MDW NOW APPEAR TO BE HUGGING THE
SHORE AND STAYING TO THE EAST...THOUGH THERE IS A SMALL WINDOW
WHERE GYY MAY SEE CIGS FALL THROUGH ABOUT THE 02Z HOUR AS THESE
CLOUDS MOVE SOUTH. DEVELOPING LOW PRESSURE ACROSS SOUTHERN KANSAS
WILL MOVE EAST OVERNIGHT AND ACROSS CENTRAL/SOUTHERN ILLINOIS
THROUGH TOMORROW AFTERNOON. AS THIS HAPPENS...THE CHANCES FOR RAIN
SHOWERS WILL INCREASE. THERE IS STILL SOME QUESTION AS TO THE
EXACT TIMING OF THE ONSET OF PRECIP. TO BEGIN...THE ATMOSPHERE
WILL BE HAVING TO FIGHT DRY CONDITIONS ALOFT. RADAR TRENDS ACROSS
IOWA ALMOST INDICATE THE NEED TO START PRECIP A FEW HOURS EARLIER.
EXPECT MUCH OF THE DAY TO SEE RAIN...AND THERE MAY BE SOME TIME
WHERE VISIBILITIES FALL INTO THE HIGH MVFR RANGE...WHILE CIGS
SLOWLY FALL THROUGH THAT RANGE. SHOULD SEE RAIN TO CONTINUE
THROUGH THE DAY AND INTO THE OVERNIGHT PERIOD...WITH THE LIKELY
HEAVIEST RAINS OCCURRING IN THE 15 TO 18Z SPAN. NOT EXPECTING ANY
THUNDER WITH THIS SYSTEM.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MODERATE CONFIDENCE ON PRECIP TIMING
* LOW CONFIDENCE IN CIG/VIS TRENDS WITH PRECIP
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
411 PM CDT
LARGE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS AND THE
UPPER MIDWEST GRADUALLY EXPANDS EASTWARD ACROSS THE GREAT LAKES
TONIGHT AND THURSDAY ALLOWING WINDS TO DIMINISH...AT LEAST
TEMPORARILY. AS LOW PRESSURE LIFTS NORTHEAST AND DEEPENS IS IT
CROSSES THE MID MISSISSIPPI VALLEY THURSDAY AFTERNOON THE
PRESSURE GRADIENT BETWEEN THE RIDGE ACROSS THE GREAT LAKES AND THE
APPROACHING LOW WILL BE ON THE INCREASE AND WILL CONTINUE TO
INCREASE THURSDAY NIGHT AS THE LOW MOVES TO NEAR WESTERN LAKE ERIE
BY FRIDAY MORNING. WINDS WILL RESPOND TO THE TIGHTENING PRESSURE
GRADIENT BY INCREASING OUT OF THE NORTH AND NORTHEAST...ESPECIALLY
ON THE SOUTH PORTION OF THE LAKE. WINDS WILL GRADUALLY BACK AND
SLACKEN LATER FRIDAY AND FRIDAY NIGHT AS THE LOW MOVES NORTH INTO
ONTARIO.
WIND AND WAVE CONDITIONS REQUIRING A SMALL CRAFT ADVISORY ARE
LIKELY FOR THE SOUTHERN PORTION OF THE ILLINOIS WATERS AND ALL OF
THE INDIANA WATERS FROM THURSDAY AFTERNOON UNTIL LATE FRIDAY.
HAZARDOUS CONDITIONS FOR SMALL CRAFT AREA ALSO LIKELY FOR THE
NORTHERN PORTION OF THE ILLINOIS WATERS THURSDAY NIGHT INTO
FRIDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY ISLAND
TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
918 PM CDT WED MAY 30 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
&&
.PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NE WINDS WITH THE OCNL GUST
* OVERNIGHT / EARLY AM PRECIP
* CIG/VIS TRENDS IN PRECIP
SHEA
//DISCUSSION...UPDATED 00Z...
OVERALL VFR CONDITIONS WILL CONTINUE OVERNIGHT. MVFR CIGS THAT
WERE THREATENING TO IMPACT ORD/MDW NOW APPEAR TO BE HUGGING THE
SHORE AND STAYING TO THE EAST...THOUGH THERE IS A SMALL WINDOW
WHERE GYY MAY SEE CIGS FALL THROUGH ABOUT THE 02Z HOUR AS THESE
CLOUDS MOVE SOUTH. DEVELOPING LOW PRESSURE ACROSS SOUTHERN KANSAS
WILL MOVE EAST OVERNIGHT AND ACROSS CENTRAL/SOUTHERN ILLINOIS
THROUGH TOMORROW AFTERNOON. AS THIS HAPPENS...THE CHANCES FOR RAIN
SHOWERS WILL INCREASE. THERE IS STILL SOME QUESTION AS TO THE
EXACT TIMING OF THE ONSET OF PRECIP. TO BEGIN...THE ATMOSPHERE
WILL BE HAVING TO FIGHT DRY CONDITIONS ALOFT. RADAR TRENDS ACROSS
IOWA ALMOST INDICATE THE NEED TO START PRECIP A FEW HOURS EARLIER.
EXPECT MUCH OF THE DAY TO SEE RAIN...AND THERE MAY BE SOME TIME
WHERE VISIBILTIES FALL INTO THE HIGH MVFR RANGE...WHILE CIGS
SLOWLY FALL THROUGH THAT RANGE. SHOULD SEE RAIN TO CONTINUE
THROUGH THE DAY AND INTO THE OVERNIGHT PERIOD...WITH THE LIKELY
HEAVEIEST RAINS OCCURING IN THE 15 TO 21Z SPAN. NOT EXPECTING ANY
THUNDER WITH THIS SYSTEM.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW CONFIDENCE ON SHORT TERM CLOUD FORECAST
* MODERATE TO HIGH CONFIDENCE ON SHORT LIVED LOW CIGS
* MODERATE CONFIDENCE ON PRECIP TIMING
* LOW CONFIDENCE IN CIG/VIS TRENDS WITH PRECIP
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
411 PM CDT
LARGE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS AND THE
UPPER MIDWEST GRADUALLY EXPANDS EASTWARD ACROSS THE GREAT LAKES
TONIGHT AND THURSDAY ALLOWING WINDS TO DIMINISH...AT LEAST
TEMPORARILY. AS LOW PRESSURE LIFTS NORTHEAST AND DEEPENS IS IT
CROSSES THE MID MISSISSIPPI VALLEY THURSDAY AFTERNOON THE
PRESSURE GRADIENT BETWEEN THE RIDGE ACROSS THE GREAT LAKES AND THE
APPROACHING LOW WILL BE ON THE INCREASE AND WILL CONTINUE TO
INCREASE THURSDAY NIGHT AS THE LOW MOVES TO NEAR WESTERN LAKE ERIE
BY FRIDAY MORNING. WINDS WILL RESPOND TO THE TIGHTENING PRESSURE
GRADIENT BY INCREASING OUT OF THE NORTH AND NORTHEAST...ESPECIALLY
ON THE SOUTH PORTION OF THE LAKE. WINDS WILL GRADUALLY BACK AND
SLACKEN LATER FRIDAY AND FRIDAY NIGHT AS THE LOW MOVES NORTH INTO
ONTARIO.
WIND AND WAVE CONDITIONS REQUIRING A SMALL CRAFT ADVISORY ARE
LIKELY FOR THE SOUTHERN PORTION OF THE ILLINOIS WATERS AND ALL OF
THE INDIANA WATERS FROM THURSDAY AFTERNOON UNTIL LATE FRIDAY.
HAZARDOUS CONDITIONS FOR SMALL CRAFT AREA ALSO LIKELY FOR THE
NORTHERN PORTION OF THE ILLINOIS WATERS THURSDAY NIGHT INTO
FRIDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
150 AM EDT TUE MAY 29 2012
.AVIATION...
06Z TAFS...SHOWERS AND THUNDERSTORMS BEGINNING TO FILL IN ALONG
ADVANCING COOL FRONT FROM EAST CENTRAL ILLINOIS INTO MISSOURI. A
BROAD UPPER LEVEL TROUGH PUSHING INTO THE UPPER MIDWEST AND AN
ASSOCIATED UPPER SPEED MAX ARE PROVIDING ENOUGH LARGE SCALE LIFT
FOR THIS INCREASED CONVECTIVE COVERAGE. SFC BASED INSTABILITY HAS
WANED ALTHOUGH STEEP LAPSE RATES JUST ABOVE THE SFC COMBINED WITH
AN AXIS OF POOLED LOW LEVEL MOISTURE MOVING INTO WESTERN
INDIANA WITH THE FRONT SHOULD CONTINUE TO SUPPORT SHOWERS AND
EMBEDDED THUNDERSTORMS. GREATEST COVERAGE IS EXPECTED TO REMAIN
SOUTH OF KSBN ASSOCIATED WITH SLIGHTLY STRONGER LOW LEVEL
CONVERGENCE TO THE SOUTH BUT DO SEE POTENTIAL OF ISOLD THUNDER AT
KSBN IN THE 07Z TO 09Z TIMEFRAME. BETTER CHANCE OF THUNDERSTORMS
FOR KFWA TERMINAL WHERE HAVE MAINTAINED TEMPO TSRA IN THE 08Z TO
11Z WINDOW. WINDS TO SHIFT WEST NORTHWEST BEHIND THE FRONT LATE
TONIGHT...WITH SOME INCREASING GUSTINESS TO 20 KNOTS BY MID TO
LATE AFTERNOON AS COOL AIR ADVECTION INCREASES DEPTH OF MIXED
LAYER. WINDS TO DIMINISH LIGHT NORTHWEST WEDNESDAY EVENING AS SFC
HIGH PRESSURE BEGINS TO BUILD IN FROM THE UPPER MIDWEST.
&&
.PREV DISCUSSION... /ISSUED 1051 PM EDT MON MAY 28 2012/
UPDATE...
BKN LINE OF TSTMS HAS WEAKENED SINCE NIGHTFALL AS EXPECTED BUT
STILL SCT ACTIVITY APCHG OUR CWA FROM NE IL. LATEST MESO/SHORT RANGE
MODELS CONT TO SUGGEST COMBINATION OF INCREASING LOW LEVEL
MOISTURE ALONG/AHEAD OF THE CDFNT AND COOLING ALOFT ASSOCIATED
WITH APCHG UPR LEVEL TROF WILL RESULT IN SHOWERS/TSTMS FILLING IN
LATE TONIGHT AS FRONT MOVES THROUGH. THUS... LEFT LIKELY POPS IN
EASTERN PORTION OF CWA FOR LATE TONIGHT. GIVEN DECREASING INSTABILITY
CONCERN FOR SVR STORMS LOW... THOUGH STILL EXPECT SOME GUSTY WINDS
AND HAIL WITH STORMS GIVEN RELATIVELY DRY AIRMASS.
PREV DISCUSSION... /ISSUED 404 PM EDT MON MAY 28 2012/
SHORT TERM... /TONIGHT THROUGH TUESDAY NIGHT/
FOCUS ON HEAT INTO THIS EVENING AND CONVECTIVE CHANCES AHEAD OF
APPROACHING COLD FRONT.
STRONG MIXING OF WARM LL TEMPS HAS ALLOWED FOR HIGHS ACROSS THE AREA
TO CLIMB INTO THE 90 TO 95 DEGREE RANGE. MUCH LIKE YESTERDAY...THIS
SAME MIXING HAS ALLOWED FOR SLIGHTLY DRIER AIR ALOFT TO BE MIXED
DOWN...LOWERING DEWPTS INTO THE MID 50S TO NEAR 60 VS LOWER TO
MIDDLE 60S. CONVECTION ASSOCIATED WITH A PRE-FRONTAL TROUGH HAS
WEAKENED CONSIDERABLY OVER THE PAST SEVERAL HOURS...PARTIALLY AS A
RESULT OF THE DRIER CONDITIONS AND TROUGH MOVING AWAY FROM BEST
DYNAMICS. CAN`T RULE OUT A STRAY SHOWER OR STORM ON THIS
FEATURE...BUT NOT WORTHY OF ANYTHING OTHER THAN SLGT CHC. HRRR MODEL
SHOWS SFC COLD FRONT...LOCATED FROM WISCONSIN TO EASTERN IOWA...MAY
BEGIN TO CATCH UP OVER THE NEXT COUPLE OF HOURS AS NEXT JET STREAK
APPROACHES. MOISTURE WAS POOLING BEHIND THE TROUGH AND AHEAD OF THE
COLD FRONT WITH DEWPTS IN THE 64 TO NEARLY 70 DEGREE RANGE.
CONVECTION SHOULD CONTINUE TO SPREAD SW WARD ALONG THE FRONT AND
MOVE EAST TOWARDS THE AREA. FAR WESTERN LOCATIONS MAY SEE STORMS
MOVE IN BETWEEN 23 AND 1Z AND THEN WORK EAST FROM THERE. WITH LOSS
OF PEAK HEATING...SOME QUESTION AS TO COVERAGE AND INTENSITY OF
ACTIVITY AS IT MOVES THROUGH THE REGION. WILL MAINTAIN LIKELY POPS
TONIGHT BUT ATTEMPT TO ADD MORE DETAIL ON TIMING. SVR CHANCES STILL
IN PLACE ALONG THE FRONT THIS EVENING WITH STEEP MID LEVEL LAPSE
RATES AND CAPES IN THE 2000-2500 J/KG RANGE. THIS INSTABILITY WILL
DECREASE WITH TIME AND BEST JET DYNAMICS TO PASS NW OF THE AREA. IF
A WELL ESTABLISHED LINE CAN MATERIALIZE...INCREASED CHANCES FOR
DAMAGING WINDS WOULD EXIST WITH AT LEAST UNIDIRECTIONAL WIND FIELD
IN PLACE WITH SOME INCREASE IN SHEAR.
FRONT WILL BE EXITING THE AREA TUESDAY MORNING. HAVE CONTINUED
DOWNWARD TREND ON POPS WITH DRY CONDITIONS NOW STARTING AT 15Z. MAIN
PUSH OF COLDER AIR WILL STILL BE BEHIND A BIT BUT ARRIVE BY TUES NGT
ALLOWING FOR COOLER AND LESS HUMID CONDITIONS INTO THE LONG TERM.
LONG TERM...
WEDNESDAY THROUGH MONDAY. DISPARAGING DETERMINISTIC MODEL RESPONSES
SUGGEST STRONG LEAN ONTO CONSISTENCY IN ORDER WRT LATER PDS. LEAN
TOWARD ECMWF WITH AT LEAST SOME RUN TO RUN SEMBLANCE. GEM STILL
APPEARS TO DIG NEXT SYSTEM /INTO EPAC ATTM/ TOO FAR SWD GOING INTO
DY4 WITH LATEST OP GFS AFFORDING MIDDLE OF ROAD APPROACH TO THE
AGAIN MORE FAVORED HIR BELTED ECMWF GIVEN OVERALL LOW AMPLITUDE FLOW
PATTERN. SRN/SERN CWA REMAINS KEYED ON ISENT UPGLIDE WITH STRONG OH
VLY CYCLOGENESIS FOR HIEST POPS PEGGED SRN CWA THU NIGHT TO ERN CWA
AT LEAST ERLY FRI. THEREAFTER...UNCERTAINTY REIGNS WITH PIN-POINT OF
PSBL MCS TOPPING UPSTREAM LOW AMPED RIDGE TO LKLY REMAIN QUITE AN
ONEROUS TASK. PREFERENCE TO REMAIN DRY DYS5-7 IN MIDST OF ONSET OF
LOW END/ERLY STAGE DROUGHT UNTIL SIGNALS BECOME MORE EVIDENT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...MURPHY
UPDATE...JT
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
617 PM CDT WED MAY 30 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 120 PM CDT WED MAY 30 2012
AS OF 17Z...AN AXIS OF 62-64F DEWPOINTS WERE OBSERVED ACROSS THE
EASTERN TEXAS PANHANDLE AND ADJACENT EXTREME WESTERN OKLAHOMA ALONG
AND WEST OF THE REMNANT OUTFLOW BOUNDARY FROM LAST NIGHTS OKLAHOMA
THUNDERSTORM COMPLEX. TEMPERATURES WERE WARMING INTO THE LOWER 80S
ACROSS MUCH OF SOUTHWEST KANSAS ON A SOUTHEAST WIND...ALLOWING
SURFACE-BASED CAPE VALUES TO EXCEED 2000 J/KG ALONG THE MOISTURE
AXIS. VISIBLE SATELLITE SHOWED A FAIRLY LARGE AREA OF STRATOCUMULUS
CLOUDS WITHIN THE MOISTURE AXIS ACROSS MUCH OF SOUTHWEST KANSAS. A
LOOK OUT THE WINDOW HERE AT THE WEATHER OFFICE CONFIRMED FAIRLY FLAT
LOOKING CUMULUS AS OF 1755 UTC. A WEAK BUT IMPORTANT SURFACE
BOUNDARY WAS OBSERVED FROM JUST SOUTH OF RUSSELL, KS
WEST-NORTHWESTWARD TO NEAR GOVE, KS. TEMPERATURES NORTH OF THIS
BOUNDARY WERE STILL HANGING IN THE LOWER 70S...WITH TEMPERATURES
RISING INTO THE LOWER 80S SOUTH OF THE BOUNDARY ACROSS MUCH OF
SOUTHWEST KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 120 PM CDT WED MAY 30 2012
THE HRRR AND RAP MODELS HAVE SHOWN A PERSISTENT CONVECTIVE
INITIATION SIGNAL ACROSS WEST CENTRAL OR SOUTHWEST KANSAS...ROUGHLY
IN AN AREA BOUNDED BY KALVESTA-GOVE-NESS CITY-KALVESTA...BY 20 TO
21Z. THIS WOULD SEEM TO MATCH THE LOCATION OF WHERE THE BOUNDARY
IS...ALTHOUGH IS A BIT FARTHER SOUTH. IT WOULD SEEM THE BEST AREA
FOR CONVECTIVE INITIATION WOULD BE JUST NORTH OF WHERE THE LATEST
HRRR RUNS HAVE IT...BUT EITHER WAY CONVECTIVE INITIATION SHOULD
OCCUR BY NO LATER THAN 22Z NORTH OF HIGHWAY 50 AND ALONG/SOUTH OF
INTERSTATE 70 IN SOUTHWEST/WEST-CENTRAL KANSAS. THE EARLY STAGE OF
CONVECTIVE MODE SHOULD BE SUPERCELLULAR WITH SURFACE-BASED CAPE
CONTINUING TO INCREASE ABOVE 3000 J/KG AND A SUBSTANTIAL AMOUNT OF
DEEP LAYER SHEAR TO SUPPORT VIGOROUS SUPERCELL THUNDERSTORMS.
SUPERCELL STORM MOTION WILL BE SOUTHEAST AT AROUND 20 TO 25 KNOTS
(NON SUPERCELL STORM MOTION BEING MORE EASTERLY). THE STORM
PREDICTION CENTER (SPC) PROBABILISTIC HAIL AND WIND ARE VERY HIGH
ACROSS MUCH OF THE DDC FORECAST AREA...INCLUDING ALL POINTS SOUTH OF
HIGHWAY 4 AND EAST OF HIGHWAY 83. THE SPC PROBABILISTIC SEVERE
WEATHER THREATS LOOK PRETTY GOOD AND AGREE ON JUST ABOUT ALL
ACCOUNTS. THE ONLY THING I QUESTION IS THE TORNADO POTENTIAL...AS
CONVECTIVE MODE AFTER A FEW HOURS MAY TRANSITION MORE TO A
QUASI-LINEAR SIGNIFICANT SEVERE EPISODE (DAMAGING TO DESTRUCTIVE
WIND POTENTIAL 80+ MPH). THIS MAY NOT OCCUR UNTIL LATER THIS
EVENING AS THE SEVERE WEATHER EVENT SHIFTS INTO OKLAHOMA. IF THE
SUPERCELL PHASE CAN LAST SEVERAL HOURS THEN THE TORNADO POTENTIAL
WILL DEFINITELY BE ENHANCED...AND FOR THAT REASON THE 10 PERCENT
TORNADO POTENTIAL (PROB OF A TORNADO WITHIN 25 MILES OF A POINT)
DOES LOOK JUSTIFIED FOR AREAS GENERALLY SOUTHEAST OF A LIBERAL TO
JETMORE TO LARNED LINE. DURING THE EVENING HOURS...THE SEVERE
WEATHER THREAT WILL DIMINISH FROM NORTH TO SOUTH AS THE MAIN AREA
SHIFTS INTO NORTHERN OKLAHOMA...HOWEVER WILL MAINTAIN SOME 20-50
POPS IN THE SOUTHEAST HALF OF THE FORECAST AREA THROUGH THE 06-09Z
TIME FRAME AS ADDITIONAL STORMS MAY DEVELOP IN THE WAKE OF THE
PRIMARY ROUND. ANYTHING DEVELOPING AFTER THE PRIMARY ROUND WILL
HAVE MUCH LESS INSTABILITY TO WORK WITH AND THE SEVERE WEATHER
THREAT SHOULD BE RATHER LOW.
THE REST OF THE FORECAST FOR LATE TONIGHT AND TOMORROW WAS
ESSENTIALLY UNCHANGED AS SUBSIDENCE AND DRIER AIR MOVES IN ON
NORTHEAST WINDS. TEMPERATURES WILL STRUGGLE TO ESCAPE THE LOWER 70S
OVER MUCH OF SOUTHWEST KANSAS ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 256 PM CDT WED MAY 30 2012
AFTER THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION
PASSES TO THE EAST, SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN
KANSAS THURSDAY AND THURSDAY NIGHT. THURSDAY WILL BE COOLER BEHIND
THE FRONT WITH HIGHS IN THE 70S. THURSDAY NIGHT`S LOWS WILL BE FAIRLY
CHILLY IN THE 40S AS SKIES REMAIN PARTLY CLOUDY WITH FAIRLY LIGHT
SOUTHERLY WINDS. HOWEVER, IF THERE ARE MORE CLOUDS THAN CLEAR AREAS,
THEN UPPER 40S WOULD BE MORE LIKELY THAN LOWER OR MID 40S. THERE IS
A VERY SLIGHT CHANCE OF ELEVATED SHOWERS DEVELOPING TOWARD THURSDAY
MORNING AS WARM ADVECTION BEGINS IN THE ABSENCE OF SIGNIFICANT
MID-LEVEL CAPPING.
WEAK UPPER-LEVEL RIDGING IS PROGGED BY ALL THE MODELS TO DEVELOP
ACROSS THE ROCKIES BY FRIDAY AND SATURDAY AND PERSIST INTO SUNDAY,
WITH NORTHWEST TO WEST-NORTHWESTERLY MID TO HIGH-LEVEL FLOW ACROSS
THE ROCKIES. THERE WILL BE A SLIGHT MID-LEVEL DOWNSLOPE COMPONENT
ACROSS THE ROCKIES, WHICH WILL TEND TO SUPPORT SOUTHERLY WINDS AND
MOISTURE TRANSPORT INTO KANSAS. GIVEN THAT MID-LEVEL CAPPING TENDS
TO BE WEAK IN THESE REGIMES, NOCTURNAL STORM CLUSTERS COULD DEVELOP
SOMEWHERE ACROSS THE CENTRAL PLAINS IN THE MID-LEVEL BAROCLINIC
ZONE, POSSIBLY AS EARLY AS THURSDAY NIGHT(AS ALREADY MENTIONED), BUT
MORE LIKELY BY FRIDAY NIGHT. THE WARMEST TEMPERATURES FRIDAY AND
SATURDAY WILL BE IN FAR SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH
WHERE HIGHS COULD REACH INTO THE UPPER 80S TO LOWER 90S, WHILE
SLIGHTLY COOLER TEMPERATURES CAN BE EXPECTED FURTHER EAST. THE MID
TO UPPER-LEVEL FLOW WILL BECOME MORE ZONAL BY SUNDAY, ALLOWING FOR
SOME LOWERING OF SURFACE PRESSURES AND WARM ADVECTION IN THE LEE OF
THE ROCKIES ALONG WITH WARMING TEMPERATURES IN THE LOWER TROPOSPHERE
ACROSS THE CENTRAL PLAINS. HIGHS COULD REACH TO BETWEEN 95 AND 100F.
A DEEP UPPER-LEVEL TROUGH WILL AMPLIFY OFF OF THE WEST COAST BY
MONDAY, WITH UPPER-LEVEL RIDGING ACROSS THE PLAINS. MONDAY SHOULD BE
FAIRLY DRY WITH HIGH AFTERNOON TEMPERATURES IN THE LOWER TO MID 90S.
ISOLATED EVENING THUNDERSTORMS CANNOT BE RULED OUT AS THE MODELS ARE
DEPICTING A WEAK SURFACE BOUNDARY CLOSE BY. THERE IS SOME
UNCERTAINTY WITH REGARDS TO THE EVOLUTION OF THE LARGE SCALE PATTERN
BY TUESDAY AND WEDNESDAY OF NEXT WEEK AND THEREAFTER. THE ECMWF AND
GEM PROGRESS THE UPPER-LEVEL TROUGH INTO CALIFORNIA/NEVADA AREA BY
WEDNESDAY WHILE THE GFS PROGRESSES THE TROUGH INTO THE NORTHERN
ROCKIES AND WESTERN CANADA. BUT ALL THREE OF THESE MODELS MAINTAIN
UPPER-LEVEL RIDGING ACROSS THE PLAINS THROUGH WEDNESDAY. HOWEVER,
THE GFS AND ECMWF SHOW PRECIPITATION IN THE MIDDLE OF THE RIDGE AXIS
EACH DAY, POSSIBLY AS A RESULT OF DAYTIME HEATING AND WEAK CAPPING.
ALSO, THE ECMWF HINTS AT A PLUME OF MID-LEVEL MOISTURE PROGRESSING
FROM THE TROPICS INTO WESTERN KANSAS, AND THIS COULD ALSO RESULT IN
PRECIPITATION EVEN IN THE UPPER-LEVEL RIDGE AXIS. DESPITE THE
UPPER-LEVEL RIDGING, AFTERNOON TEMPERATURES COULD BE HELD DOWN INTO
THE UPPER 80S TO LOWER 90S TUESDAY BY CLOUDS AND PRECIPITATION IF
THIS MOIST SCENARIO ACTUALLY PANS OUT. SEVERE WEATHER CHANCES LOOK
MINIMAL DUE TO THE WEAK WINDS THROUGHOUT THE TROPOSPHERE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 604 PM CDT WED MAY 30 2012
ONGONG CONVECTION NEAR HAYS WILL BRIEFLY TAPER OFF BETWEEN 00Z AND
01Z BEFORE ANOTHER ROUND OF THUNDERSTORMS CROSSES NORTH CENTRAL
KANSAS EARLY THIS EVENING. THIS AREA OF THUNDERSTORMS WILL BE
ASSOCIATED WITH A COLD FRONT SO ONCE THIS CROSSES NORTH CENTRAL
KANSAS THE PRECIPITATION IS EXPECTED TO END AS GUSTY NORTH WINDS
DEVELOP IN THE WAKE OF THIS FRONT. BASED ON DPROG/DT THIS
FRONT/THUNDERSTORMS WILL ALSO BE LOCATED IN THE GCK AREA BETWEEN
01Z AND 03Z AND DDC BETWEEN 02Z AND 04Z. BEHIND THIS FRONT GUSTY
NORTH WINDS AND MVFR CIGS ARE BRIEFLY EXPECTED FOR SEVERAL HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 54 72 47 83 / 50 10 10 20
GCK 52 72 47 84 / 70 10 10 20
EHA 54 76 50 89 / 20 10 10 10
LBL 53 75 49 87 / 40 10 10 10
HYS 52 69 46 78 / 70 10 20 20
P28 59 72 48 78 / 70 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
351 PM CDT TUE MAY 29 2012
.SYNOPSIS...TD BERYL IS STILL OVER SERN GA. BROAD HIGH PRESSURE IS
OVER THE GULF ALONG WITH THE NRN AND HIGH PLAINS. BROAD AREA OF LOW
PRESSURE IS OVER THE SRN PLAINS AND GRT LAKES. IN THE MID LVLS RIDGE
IS OVER THE BAJA AND OLD MEXICO. POTENT PAC NW ENERGY IS CONTINUING
TO MOVE IN. OLD WRN CONUS TROUGH CONTINUES TO QUICKLY PUSH EAST
ACROSS THE CNTRL CANADIAN BORDER. SKIES ACTUALLY BECAME MOSTLY SUNNY
AND THIS ALLOWED TEMPS TO RISE NICELY WITH HIGHS IN THE MID 90S IN
MANY LOCATIONS. /CAB/
&&
.SHORT TERM...TODAY MAY BE ONE OF THE LAST DAYS UNTIL THIS WEEKEND
WITH AN OVERALL QUIET FCST. WE WILL BE TRANSITIONING INTO MORE OF A
WEAK NW FLOW REGIME TONIGHT AND THIS COULD ACTUALLY SEND A WEAK
IMPULSE ACROSS THE REGION TOMORROW. PWS ARE EXPECTED TO BE NEAR 1.5"
AND WITH AN ACTUAL DISTURBANCE MOVING INTO THE REGION WE COULD SEE
DECENT COVERAGE OF SHRA/TSRA. WITH NW FLOW EXPECT ACTIVITY TO BE A
LITTLE LATER IN THE DAY LIKELY HOLDING OFF UNTIL 19/20Z. A FEW
STORMS COULD BE STRONG WITH DOWNBURST WINDS POSSIBLE. AFTER THE
DISTURBANCE MOVES THROUGH THINGS WILL QUICKLY DIE DOWN OVERNIGHT AND
WE SHOULD REMAIN QUIET FOR THE MOST PART UNTIL OUR COLD FRONT
APPROACHES LATE THU NIGHT.
THE ENERGY THAT HAS MOVED IN FROM THE PAC NW WILL CAUSE THE TROUGH
TO DEVELOP OVER THE CNTRL/ERN CONUS THU. THIS WILL INDUCE
CYCLOGENESIS OVER THE MID MS/OH/TN VALLEYS WITH A COLD FRONT
STRETCHING BACK INTO NE TX. THERE WILL BE A POTENT DISTURBANCE
EMBEDDED IN THE FLOW WORKING SE ACROSS THE LOWER MS VALLEY BUT IT
APPEARS IT WILL REMAIN MOSTLY NORTH OF THE REGION BUT IT WILL HELP
TO PUSH THE COLD FRONT INTO THE CWA LATE THU NIGHT. THIS WILL LEAD
TO AN INCREASE IN SHRA/TSRA OVER MUCH OF THE AREA EARLY FRI MORNING
BUT THE QUESTION IS WILL WE HAVE ANY STRONG/SVR STORMS. AT THIS TIME
WE CAN NOT RULE OUT A FEW POTENT STORMS BUT OVERALL THE BULK OF THE
SUPPORT WILL REMAIN WELL OFF TO OUR NORTH. IN ADDITION TO THAT THE
FRONT WILL REALLY START TO LOSE ITS PUNCH EARLY FRI MORNING. AS THE
SFC LOW TRACKS MORE TO THE NORTH THAN EAST THE FRONT WILL BECOME
ELONGATED AND START TO SLOW DOWN AND THAT WILL HURT SVR TSRA
DEVELOPMENT AS WELL. THAT SAID THERE WILL BE MORE THAN SUFFICIENT
INSTABILITY AND MOISTURE TO WORK WITH AND A FEW STORMS COULD BECOME
AN ISSUE. MAIN CONCERN FROM ANY STRONG TO SEVERE STORMS WOULD BE IN
THE FORM OF STRONG TO DAMAGING WINDS.
THE COLD FRONT WILL CONTINUE TO WORK INTO THE GULF WITH RAIN LIKELY
ENDING OVER MUCH OF THE AREA BY EARLY AFTN. HIGH PRESSURE WILL
QUICKLY BUILD IN BEHIND THE COLD FRONT WITH MUCH DRIER AIR MOVING
IN. /CAB/
.LONG TERM...MEDIUM RANGE BOTH AGREE THE TROUGH WILL BE RATHER
PROGRESSIVE AND QUICKLY PUSH EAST WITH THE AREA RECOVERING QUICKLY.
OVERALL WILL CONTINUE THE TRENDS FROM THE PREVIOUS FCST.
THE TROUGH WILL QUICKLY PUSH EAST AND BY SUN NIGHT THE NEXT MID LVL
RIDGE WILL ALREADY BE BACK OVER THE REGION. FRI NIGHT HIGH
PRESSURE WILL BE OVER THE REGION WITH VERY DRY AIR IN PLACE. THIS
SHOULD LEAD TO A VERY PLEASANT NIGHT WITH MORNING LOWS IN THE UPPER
50S ACROSS SRN MS AND LOWER TO MID 60S ELSEWHERE AND A DRY FCST
THROUGH THE WEEKEND. THIS WILL BE SHORT LIVED THOUGH AS THE SFC HIGH
QUICKLY WORKS TO THE EAST AND THIS WILL LEAD TO ONSHORE FLOW BY SUN
MORNING. IN FACT MDLS ARE ADVERTISING DEWPOINTS RECOVERING AROUND 15
DEGREES FROM SAT MORNING TO SUN MORNING. BY MON MOISTURE WILL BE
BACK OVER THE AREA WITH WEAK WRLY TO SWRLY FLOW WHICH WILL LEAD TO
SCT CONVECTION MON AFTN. RIDGE LOOKS LIKE IT WILL REMAIN IN PLACE
THROUGH THE FIRST HALF OF THE WEEK SO LOOK FOR THE HOT HUMID
CONDITIONS TO RETURN. /CAB/
&&
.MARINE...PRESSURE GRADIENT HAS REMAINED A LITTLE TIGHTER THAN WHAT
WAS EXPECTED AND SHOULD REMAIN THAT WAY THROUGH THE NIGHT. WINDS
WILL DO THEIR USUAL THING AND PICK UP A TAD OVERNIGHT...ESPECIALLY
EAST OF THE DELTA WHERE WINDS SHOULD BE 15-20 KNOTS AT TIMES. WINDS
WILL BACK OFF AROUND SUNRISE AND WILL THEN BECOME MORE ONSHORE OVER
THE NEXT FEW DAYS. STILL LOOKS LIKE A COLD FRONT WILL TRY TO PUSH
INTO THE COASTAL WATERS FRI BUT IT WILL REALLY LOSE A LOT OF ITS
IDENTITY RATHER QUICKLY FRI NIGHT. THAT SAID WE WILL STILL SEE WINDS
BECOME OFFSHORE AS HIGH PRESSURE QUICKLY BUILDS IN BEHIND IT. THIS
WILL BE SHORT LIVED AS THE HIGH WILL DEPART EVEN FASTER ALLOWING
ONSHORE FLOW TO QUICKLY RETURN. /CAB/
&&
.AVIATION...CUMULUS FIELD WAS VERY SLOW TO DEVELOP THIS
MORNING...MAINLY APPARENT OVER COASTAL MISSISSIPPI. A FEW SHOWERS
HAVE DEVELOPED OVER THE MOBILE AREA...AND HRRR INDICATES THEY COULD
BUILD BACK TOWARD KGPT AND KHSA TOWARD SUNSET BEFORE DISSIPATING.
WILL CONTINUE TO MONITOR FOR THE REMAINDER OF THE AFTERNOON.
OTHERWISE...CHANCES FOR THUNDERSTORMS AROUND 10 PERCENT TODAY...SO
HAVE NO PLANS TO COVER IN FORECAST. EXPECT VFR CONDITIONS TO BE
PREDOMINANT THROUGH THE PERIOD. CANNOT RULE OUT SOME MVFR
VISIBILITIES AROUND SUNRISE WEDNESDAY. DID NOT SEE THEM OCCUR THIS
MORNING. CONVECTIVE CHANCES WILL IMPROVE SLIGHTLY TOMORROW
AFTERNOON. NOT LARGE ENOUGH CHANCE OR AREAL COVERAGE TO CARRY IN
FORECAST...BUT WILL LIKELY END UP WITH THEM NEAR A SITE OR TWO
DURING WEDNESDAY AFTERNOON. /35/
&&
DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR
DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 68 92 69 88 / 10 30 20 20
BTR 71 92 72 88 / 10 30 20 20
ASD 71 90 72 87 / 10 20 20 20
MSY 74 91 74 88 / 10 20 10 20
GPT 72 87 73 86 / 10 20 20 10
PQL 68 91 70 89 / 20 10 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
SHORT/LONG/MARINE: CAB
AVIATION: 35
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
410 PM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL IS EXPECTED TO SLOWLY PROGRESS
NORTHEASTWARD THIS EVENING AND MOVE INTO COASTAL SOUTH CAROLINA
OVERNIGHT. AN APPROACHING COLD FRONT WILL PULL BERYL FARTHER UP THE
CAROLINA COAST WEDNESDAY...BRINGING RAIN TO MUCH OF THE LOCAL
AREA. WEAK HIGH PRESSURE BUILDS INTO THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LOW STRATO-CU FROM EARLIER THIS MORNING HAS SCOURED OUT NICELY
ACROSS CENTRAL VA THIS AFTERNOON AND HAS ALLOWED FOR ANOTHER
ROUND OF WARM TEMPS ACROSS THE REGION ALONG WITH MUGGY CONDITIONS.
T.D. BERYL REMAINS OVER SE GA THIS AFTERNOON. A COASTAL BOUNDARY
HAS DEVELOPED OVER EASTERN NC TO THE NE OF BERYL. THIS LINE HAS
MADE GOOD PROGRESS NORTHWARD INTO NE NC RECENTLY AND EXPECT THIS
ACTIVITY TO CONTINUE TO MOVE INTO SOUTHERN/SE VIRGINIA THROUGH THE
EVENING HOURS. AS SUCH WILL INCREASE POPS A BIT MORE ACROSS SE
SECTIONS...AT LEAST GETTING SCATTERED POPS 30-40% INTO SE VA.
WILL HAVE TO CONTINUE TO MONITOR THE NORTHWARD TREND OF THE
COASTAL BOUNDARY THIS EVENING AND ADJUST POPS AS NECESSARY. FOR
NOW...WILL CARRY CHC POPS (~30%) ACROSS SE VA AND NE NC. OTW...THE
NEXT CONCERN WILL BE THE APPROACHING COLD FRONT FROM THE MIDWEST
WHICH HAS A FAIR AMOUNT OF THUNDERSTORM ACTIVITY WITH IT AS IT
PUSHES INTO THE APPALACHIANS THIS AFTERNOON. THE LATEST SHORT TERM
MODELS INCLUDING THE HRRR BRING SOME OF THIS ACTIVITY INTO OUR
WESTERN/NW ZONES LATE THIS EVENING THROUGH MIDNIGHT. HAVE INCLUDED
SOME HIGH CHC TO LOW END LIKELY POPS (50-60%) FOR NW AREAS THIS
EVENING TO ACCOUNT FOR THIS POSSIBILITY. AS THE FRONT FROM THE
MIDWEST ARRIVES OVERNIGHT AND DEEPER MOISTURE FROM BERYL BEGINS TO
OVERSPREAD THE REGION (AS BERYL MOVES UP THE SC COAST)...SHOULD
SEE AN INCREASE IN PCPN COVERAGE OVERNIGHT. WILL GO AT LEAST
LIKELY POPS MOST AREAS AFTER 06Z. TEMPS WILL BE MILD OVERNIGHT WITH
LOWS ONLY IN THE UPR 60S TO LOW 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE LATEST NHC TRACK HAS BERYL MOVING NE AND HUGGING THE CAROLINA
COAST THROUGH WED NIGHT BEFORE HEADING WELL OUT INTO THE ATLANTIC
ON THURSDAY. ALTHOUGH BERYL WILL NOT DIRECTLY IMPACT THE LOCAL
AREA...THE INTERACTION BETWEEN IT AND THE AFOREMENTIONED FRONTAL
BOUNDARY WILL PRODUCE WIDESPREAD SHOWERS (SOME HEAVY) ALONG WITH
THE POSSIBILITY OF SOME THUNDERSTORMS ON WEDNESDAY. THE HEAVIEST
PCPN IS EXPECTED ACROSS SE VA AND NE NC (CLOSEST TO THE TRACK OF
BERYL). HAVE LIKELY TO CATEGORICAL POPS (60-80%) ACROSS ALL OF THE
REGION WED MORNING THROUGH EARLY AFTERNOON (SAVE FOR NW
ZONES)...TAPERING OFF TO SLIGHT CHC/CHC POPS (20-40%) ACROSS
NORTHERN AND WESTERN AREAS AFTER 18Z. WILL MAINTAIN CHC POPS (30%)
ACROSS EASTERN AREAS WED EVENING AS BERYL HEADS OUT TO SEA BUT FOR
THE MOST PART THE STEADIEST RAIN WILL BE OVER BY SUNSET. MAX TEMPS
WED WILL BE IN THE UPR 70S TO LOW 80S.
QPF AMOUNTS THROUGH WED REMAIN SOMEWHAT PROBLEMATIC GIVEN THE
TROPICAL NATURE OF THE AIRMASS...AND SOME UNCERTAINTY IN THE EXACT
TRACK OF BERYL. HAVE STAYED CLOSE TO HPC GUIDANCE WHICH INDICATES
1-2 INCHES FOR MUCH OF SE VA AND NE NC WITH HIGHER AMOUNTS UP TO 3
INCHES POSSIBLE IN COASTAL NE NC. PROBABLY LOOKING AT LESS THAN 1
INCH TO THE NW OF RICHMOND BUT ANY CHANGE IN TRACK COULD ALTER
THIS QUITE A BIT. WILL CONTINUE TO HIGHLIGHT POTENTIAL OF HEAVY
RAIN IN THE HWO FOR WEDNESDAY. OVERALL...THE LOCAL AREA HAS BEEN
IN A RAIN DEFICIT OVER THE PAST SEVERAL MONTHS SO THE GROUND CAN
EASILY HANDLE A COUPLE OF INCHES OF RAIN. THEREFORE...FLASH FLOOD
WATCHES ARE NOT ANTICIPATED.
HIGH PRESSURE RETURNS WED NIGHT AND THURSDAY FOR A RETURN OF DRY
WX. THE NEXT SYSTEM WILL MOVE OUT OF THE MIDWEST ON FRIDAY AND
SHOULD BRING A CHANCE OF SHOWERS/STORMS TO THE LOCAL AREA LATE IN
THE DAY. HIGHS THURSDAY AND FRIDAY WILL BE IN THE LOW/MID 80S. LOW
TEMPS WILL REMAIN IN THE 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
WILL BE GOING CLSR TO THE 12Z GFS FOR THE EXTENDED PERIOD...ESPLY
WITH REGARD TO THE TIMING OF COLD FRNT PUSHING INTO AND ACRS THE
AREA FRI NGT THRU SAT MORNG. GOING WITH LIKELY POPS (60 PERCENT AT
THIS TIME) FOR SHOWERS AND TSTMS FM FRI EVENG INTO ERLY SAT MORNG
ACRS THE ENTIRE REGION. HIGHEST CHC POPS LINGER IN THE ENE CNTIES
SAT MORNG...OTHRWISE THE SKY SHOULD BECOME PRTLY OR MSTLY SNY THE
REMAINDER OF THE DAY. HI PRES WILL THEN BE CNTRD OVR THE GULF CST
STATES AND FL FM SUN THRU TUE...WHILE WEAK TROFS...IN THE NRN STREAM
SWING THRU THE REGION SUN NGT...AND AGAIN MON NGT THRU TUE. AT THIS
TIME...WILL HAVE MORE CLDS FM SUN NGT THRU TUE...BUT KEEP THE FCST
DRY DURING THIS PERIOD. MIN TEMPS WILL RANGE THRU THE 60S SAT
MORNG...IN THE MID 50S TO MID 60S SUN MORNG...IN THE LWR TO MID 60S
MON MORNG...AND IN THE MID TO UPR 60S TUE MORNG. MAX TEMPS WILL
RANGE FM THE UPR 70S TO LWR 80S SAT AND SUN...AND IN THE MID TO UPR
80S MON AND TUE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
PERIOD BEGINS WITH VFR CONDITIONS AS LOW LEVEL MOISTURE...THAT
PRODUCED LOW CEILINGS EARLIER TODAY...AS NOW LIFTED INTO A CU
FIELD WITH VFR CONDITIONS IN PLACE ACROSS THE AREA.
HOWEVER...EXPECT THOSE CONDITIONS TO DETERIORATE THIS EVENING AND
OVERNIGHT AS MOISTURE ASSOCIATED WITH TD BERYL INTERACTS WITH AN
APPROACHING COLD FRONT ARRIVING FROM THE WEST. INITIAL MOISTURE
PLUME AND WEAK COASTAL BOUNDARY ARE PRODUCING SCATTERED CONVECTION
OVER ERN NC. HAVE ADDED A TEMPO GROUP FOR MVFR CONDITIONS WITH
THIS BAND OF SHOWERS FOR ECG. AT THIS TIME...NOT SOLD ON IT MAKING
IT TOO FAR INTO VA...BUT IT COULD IMPACT ORF. THIS BAND SHOULD
WEAKEN AFTER SUNSET
OVERNIGHT...CLOUDS WILL BE INCREASING WITH MVFR TO IFR CONDITIONS
IN THE RAIN THAT DEVELOPS AS THE FRONT GETS CLOSER AND BERYL
BEGINS TO MOVE NE ALONG THE CAROLINA COAST. SHOULD BEGIN TO RAIN
DEVELOPING ACROSS THE SOUTH AROUND 6Z AND FURTHER NORTH BETWEEN 8Z
AND 10Z. ONCE THE RAIN BEGINS...WILL SEE CONDITIONS DROP TO MVFR
LEVELS AND PERHAPS EVEN DOWN TO IFR CEILINGS...ESPECIALLY FOR ORF
AND ECG WHICH WILL BE CLOSER TO THE INFLUENCE OF BERYL. BY
16Z...THE WEAKENING SFC FRONT CLEARS RIC AND SHOULD BEGIN TO SEE
IMPROVING CONDITIONS THERE...BUT THE MORE EASTERN SITES WILL STILL
BE IMPACTED THE COMBINATION OF THE FRONT AND BERYL TO KEEP
CONDITIONS UNSETTLED INTO WEDNESDAY EVENING WHEN BERYL PULLS AWAY
FROM THE COAST...TURNING THE FLOW NW AND DRYING THINGS OUT.
A RETURN OF VFR W/ HIGH PRES THU. ANOTHER COLD FRONT APPROACHES ON
FRIDAY WITH MORE CONVECTION EXPECTED TO DEVELOP AS THE COLD FRONT
SLIDES ACROSS THE REGION.
&&
.MARINE...
WILL CONTINUE WITH SCA THRU LATE TNGT FOR THE CSTL WTRS FM FENWICK
ISLAND TO CAPE CHARLES LGT...DUE TO S WNDS INCREASING THE SEAS TO 5
FT. OTHRWISE...GOING CLSR TO THE NAM12 WNDS THRU 12Z WED...THEN WENT
WITH A COMBINATION OF NAM12 AND MOSGUIDE WNDS FM 15Z WED THRU THU
WITH REGARD TO THE MOVEMENT OF BERYL. WILL LIKELY NEED SCA FOR THE
SRN TWO CSTL WTRS...ESPLY FOR INCREASING SEAS...FM BERYL WED NGT
INTO ERLY THU. SW WNDS ON WED WILL GRADUALLY SHIFT TO THE ENE BY
LATE WED...THEN BECOME NE THEN NNW FOR WED NGT INTO THU MORNG. HI
PRES BLDS INTO AND OVR THE AREA THU INTO FRI. THEN...A COLD FRNT
APPROACHES FM THE W LATE FRI...THEN PUSHES ACRS THE WTRS LATE FRI
NGT THRU MIDDAY SAT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ650-652-
654.
&&
$$
SYNOPSIS...JDM/MAS
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...TMG
AVIATION...ESS
MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
338 PM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL IS EXPECTED TO SLOWLY PROGRESS
NORTHEASTWARD THIS EVENING AND MOVE INTO COASTAL SOUTH CAROLINA
OVERNIGHT. AN APPROACHING COLD FRONT WILL PULL BERYL FARTHER UP THE
CAROLINA COAST WEDNESDAY...BRINGING RAIN TO MUCH OF THE LOCAL
AREA. WEAK HIGH PRESSURE BUILDS INTO THE AREA THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW STRATO-CU FROM EARLIER THIS MORNING HAS SCOURED OUT NICELY
ACROSS CENTRAL VA THIS AFTERNOON AND HAS ALLOWED FOR ANOTHER
ROUND OF WARM TEMPS ACROSS THE REGION ALONG WITH MUGGY CONDITIONS.
T.D. BERYL REMAINS OVER SE GA THIS AFTERNOON. A COASTAL BOUNDARY
HAS DEVELOPED OVER EASTERN NC TO THE NE OF BERYL. THIS LINE HAS
MADE GOOD PROGRESS NORTHWARD INTO NE NC RECENTLY AND EXPECT THIS
ACTIVITY TO CONTINUE TO MOVE INTO SOUTHERN/SE VIRGINIA THROUGH THE
EVENING HOURS. AS SUCH WILL INCREASE POPS A BIT MORE ACROSS SE
SECTIONS...AT LEAST GETTING SCATTERED POPS 30-40% INTO SE VA.
WILL HAVE TO CONTINUE TO MONITOR THE NORTHWARD TREND OF THE
COASTAL BOUNDARY THIS EVENING AND ADJUST POPS AS NECESSARY. FOR
NOW...WILL CARRY CHC POPS (~30%) ACROSS SE VA AND NE NC. OTW...THE
NEXT CONCERN WILL BE THE APPROACHING COLD FRONT FROM THE MIDWEST
WHICH HAS A FAIR AMOUNT OF THUNDERSTORM ACTIVITY WITH IT AS IT
PUSHES INTO THE APPALACHIANS THIS AFTERNOON. THE LATEST SHORT TERM
MODELS INCLUDING THE HRRR BRING SOME OF THIS ACTIVITY INTO OUR
WESTERN/NW ZONES LATE THIS EVENING THROUGH MIDNIGHT. HAVE INCLUDED
SOME HIGH CHC TO LOW END LIKELY POPS (50-60%) FOR NW AREAS THIS
EVENING TO ACCOUNT FOR THIS POSSIBILITY. AS THE FRONT FROM THE
MIDWEST ARRIVES OVERNIGHT AND DEEPER MOISTURE FROM BERYL BEGINS TO
OVERSPREAD THE REGION (AS BERYL MOVES UP THE SC COAST)...SHOULD
SEE AN INCREASE IN PCPN COVERAGE OVERNIGHT. WILL GO AT LEAST
LIKELY POPS MOST AREAS AFTER 06Z. TEMPS WILL BE MILD OVERNIGHT WITH
LOWS ONLY IN THE UPR 60S TO LOW 70S.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
THE LATEST NHC TRACK HAS BERYL MOVING NE AND HUGGING THE CAROLINA
COAST THROUGH WED NIGHT BEFORE HEADING WELL OUT INTO THE ATLANTIC
ON THURSDAY. ALTHOUGH BERYL WILL NOT DIRECTLY IMPACT THE LOCAL
AREA...THE INTERACTION BETWEEN IT AND THE AFOREMENTIONED FRONTAL
BOUNDARY WILL PRODUCE WIDESPREAD SHOWERS (SOME HEAVY) ALONG WITH
THE POSSIBILITY OF SOME THUNDERSTORMS ON WEDNESDAY. THE HEAVIEST
PCPN IS EXPECTED ACROSS SE VA AND NE NC (CLOSEST TO THE TRACK OF
BERYL). HAVE LIKELY TO CATEGORICAL POPS (60-80%) ACROSS ALL OF THE
REGION WED MORNING THROUGH EARLY AFTERNOON (SAVE FOR NW
ZONES)...TAPERING OFF TO SLIGHT CHC/CHC POPS (20-40%) ACROSS
NORTHERN AND WESTERN AREAS AFTER 18Z. WILL MAINTAIN CHC POPS (30%)
ACROSS EASTERN AREAS WED EVENING AS BERYL HEADS OUT TO SEA BUT FOR
THE MOST PART THE STEADIEST RAIN WILL BE OVER BY SUNSET. MAX TEMPS
WED WILL BE IN THE UPR 70S TO LOW 80S.
QPF AMOUNTS THROUGH WED REMAIN SOMEWHAT PROBLEMATIC GIVEN THE
TROPICAL NATURE OF THE AIRMASS...AND SOME UNCERTAINTY IN THE EXACT
TRACK OF BERYL. HAVE STAYED CLOSE TO HPC GUIDANCE WHICH INDICATES
1-2 INCHES FOR MUCH OF SE VA AND NE NC WITH HIGHER AMOUNTS UP TO 3
INCHES POSSIBLE IN COASTAL NE NC. PROBABLY LOOKING AT LESS THAN 1
INCH TO THE NW OF RICHMOND BUT ANY CHANGE IN TRACK COULD ALTER
THIS QUITE A BIT. WILL CONTINUE TO HIGHLIGHT POTENTIAL OF HEAVY
RAIN IN THE HWO FOR WEDNESDAY. OVERALL...THE LOCAL AREA HAS BEEN
IN A RAIN DEFICIT OVER THE PAST SEVERAL MONTHS SO THE GROUND CAN
EASILY HANDLE A COUPLE OF INCHES OF RAIN. THEREFORE...FLASH FLOOD
WATCHES ARE NOT ANTICIPATED.
HIGH PRESSURE RETURNS WED NIGHT AND THURSDAY FOR A RETURN OF DRY
WX. THE NEXT SYSTEM WILL MOVE OUT OF THE MIDWEST ON FRIDAY AND
SHOULD BRING A CHANCE OF SHOWERS/STORMS TO THE LOCAL AREA LATE IN
THE DAY. HIGHS THURSDAY AND FRIDAY WILL BE IN THE LOW/MID 80S. LOW
TEMPS WILL REMAIN IN THE 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE MOVES THROUGH THE OHIO VALLEY INTO NORTHEASTERN STATES
FRIDAY AND EARLY SATURDAY. THERE ARE TIMING ISSUES BETWEEN THE GFS
AND EURO WITH GFS BEING SOMEWHAT SLOWER. PER HPC...FOLLOWED CLOSE TO
EURO. HAVE PCPN BEGINNING IN WRN PORTIONS EARLY FRIDAY MORNING WITH
LIKELY POPS FOR SHOWERS AND THUNDERSTORMS IN WESTERN PORTIONS DURING
THE DAY FRIDAY. PCPN CONTINUES INTO FRIDAY EVENING ESPECIALLY
EASTERN AREAS. COLD FRONT MOVES QUICKLY THROUGH THE AREA FRIDAY
NIGHT AND EARLY SATURDAY MORNING...PUTTING AN END TO THE PCPN. IN
ORDER TO ACCOUNT FOR SOME TIMING UNCERTAINTY AND FOR BETTER
COLLABORATION...HAVE LOW POPS INTO SATURDAY MORNING.
HIGH PRESSURE BUILDS INTO THE AREA NEXT WEEKEND AND SETTLES OVER THE
MID ATLANTIC STATES MONDAY.
HIGH TEMPERATURES AROUND 80 TO 85 COOL SLIGHTLY TO THE MID 70S TO
LOWER 80S SATURDAY THROUGH MONDAY. LOWS WILL GENERALLY RUN FROM 60
TO 65.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
PERIOD BEGINS WITH VFR CONDITIONS AS LOW LEVEL MOISTURE...THAT
PRODUCED LOW CEILINGS EARLIER TODAY...AS NOW LIFTED INTO A CU
FIELD WITH VFR CONDITIONS IN PLACE ACROSS THE AREA.
HOWEVER...EXPECT THOSE CONDITIONS TO DETERIORATE THIS EVENING AND
OVERNIGHT AS MOISTURE ASSOCIATED WITH TD BERYL INTERACTS WITH AN
APPROACHING COLD FRONT ARRIVING FROM THE WEST. INITIAL MOISTURE
PLUME AND WEAK COASTAL BOUNDARY ARE PRODUCING SCATTERED CONVECTION
OVER ERN NC. HAVE ADDED A TEMPO GROUP FOR MVFR CONDITIONS WITH
THIS BAND OF SHOWERS FOR ECG. AT THIS TIME...NOT SOLD ON IT MAKING
IT TOO FAR INTO VA...BUT IT COULD IMPACT ORF. THIS BAND SHOULD
WEAKEN AFTER SUNSET
OVERNIGHT...CLOUDS WILL BE INCREASING WITH MVFR TO IFR CONDITIONS
IN THE RAIN THAT DEVELOPS AS THE FRONT GETS CLOSER AND BERYL
BEGINS TO MOVE NE ALONG THE CAROLINA COAST. SHOULD BEGIN TO RAIN
DEVELOPING ACROSS THE SOUTH AROUND 6Z AND FURTHER NORTH BETWEEN 8Z
AND 10Z. ONCE THE RAIN BEGINS...WILL SEE CONDITIONS DROP TO MVFR
LEVELS AND PERHAPS EVEN DOWN TO IFR CEILINGS...ESPECIALLY FOR ORF
AND ECG WHICH WILL BE CLOSER TO THE INFLUENCE OF BERYL. BY
16Z...THE WEAKENING SFC FRONT CLEARS RIC AND SHOULD BEGIN TO SEE
IMPROVING CONDITIONS THERE...BUT THE MORE EASTERN SITES WILL STILL
BE IMPACTED THE COMBINATION OF THE FRONT AND BERYL TO KEEP
CONDITIONS UNSETTLED INTO WEDNESDAY EVENING WHEN BERYL PULLS AWAY
FROM THE COAST...TURNING THE FLOW NW AND DRYING THINGS OUT.
A RETURN OF VFR W/ HIGH PRES THU. ANOTHER COLD FRONT APPROACHES ON
FRIDAY WITH MORE CONVECTION EXPECTED TO DEVELOP AS THE COLD FRONT
SLIDES ACROSS THE REGION.
&&
.MARINE...
HI PRES OFFSHR...RESULTING IN SSW WNDS AVGG ABT 15 KT RIGHT NOW.
PREVAILING LLVL FLO WL RMN FM THE SSW THROUGH TNGT. WNDS BCM MR VRBL
ON WED AS CDFNT CROSSES THE AREA AND LO PRES PASSES ENE NR THE ERN
NC CST. HIGHEST SPDS (TO PSBLY 20-25 KT) INVOF NE NC CSTL
WTRS...ELSW SPDS AVGG AOB 15 KT. A SCND CDNFT CROSSES THE WTRS ERY
THU. COMBO LO PRES TRACKING OUT TO SEA AND PD OF LLVL CAA POST CDFNT
WL BRING A SURGE IN SPDS FM THE NNW LT WED NGT INTO THU. KEEPING
SPDS BLO SCA FOR NOW. WNDS BCM E THEN SSE ON FRI...AND INCRS IN SPD
AHD OF NEXT CDFNT APPROACHING LT FRI.
SCAS RMNG UP FOR NRN 3 OCN ZONES...THOUGH SEAS XPCD TO BE MARGINAL
(AVG ARND 5 FT). PSBL SCAS NEEDED FOR SRN OCN ZONES WED AFTN INTO
WED NGT AS LO PRES TRACKS OFF ERN NC. HIGHEST SPDS W/ THAT SYS XPCD
TO RMN OFFSHR/IN ESE QUADRANT. MONITOR TPC FOR INFO/TRACK OF BERYL.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ650-652-654.
&&
$$
SYNOPSIS...JDM/MAS
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...
AVIATION...ESS
MARINE...
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
739 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION TODAY, BRINGING SHOWERS AND
THUNDERSTORMS TO THE AREA. SOME OF THE STORMS COULD BECOME SEVERE. A
BREAK FROM SHOWERS AND STORMS IS ANTICIPATED FOR THE MID-WEEK
BEFORE A MORE ORGANIZED LOW PRESSURE SPREADS WIDESPREAD RAINFALL
AND MUCH COOLER WEATHER BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7AM UPDATE... TIMING OF PRECIP LOOKS GOOD WITH AROUND 15 TO 16Z
REACHING WESTERN CWA AND AROUND 17Z WHEELING AND PITTSBURGH METRO
AREAS. CHANGED WEATHER GRIDS TO INDICATE POSSIBLE SEVERE AND WITH
HEAVY RAINFALL. REMAINDER UNCHANGED.
A QUICK UPDATE HAS BEEN ISSUED THIS MORNING TO BRING IN LIKELY
POPS A FEW HOURS EARLIER IN EASTERN OHIO THIS MORNING. THIS TAKES
INTO ACCOUNT UPSTREAM CONVECTION AHEAD THAT IS MOVING INTO
WESTERN OHIO AHEAD OF A COLD FRONT. THE PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW AHEAD OF A TROUGH ACROSS THE UPPER
MIDWEST. AT THE SURFACE, A 1000MB LOW IS LOCATED NORTH OF LAKE
HURON WITH A COLD FRONT EXTENDING SOUTHWARD ACROSS MICHIGAN AND
INTO INDIANA. THIS FEATURE IS CONTRIBUTING TO AN ENHANCED SOUTHERLY
FLOW WITH WARM AIR ADVECTION KEEPING TEMPS AND DEW POINTS UP THIS
MORNING. TEMPS ARE IN THE LOWER TO MID 70S ACROSS MUCH OF THE AREA
WITH TDS IN THE MID TO UPPER 60S.
EARLY TODAY...THE COLD FRONT WILL CROSS THE OHIO VALLEY. WARM AND
HUMID CONDITIONS WILL CONTINUE THIS MORNING AHEAD OF THE COLD
FRONT. CLOUDS WILL BE ON THE INCREASE AS THE COLD FRONT CHARGES
EAST FROM THE GREAT LAKES. WITH MODERATE ELEVATED INSTABILITY, THE
ISOLATED DEVELOPMENT OF CONVECTION CANNOT BE RULED OUT EARLY IN EASTERN
OHIO.
THUNDERSTORMS WILL BECOME NUMEROUS WITH THE 4KM NAM SUPPORTING
DEVELOPMENT CONGEALING INTO AN MCS BY LATE AFTERNOON AS THE FRONT
WORKS INTO REGION. STRONG TO SEVERE THUNDERSTORMS ALONG AND AHEAD
OF THE COLD FRONT ARE ANTICIPATED TO REACH EASTERN OHIO BY 18Z AND
BY 21Z ACROSS WESTERN PA. THE LATEST SPC DAY 1 OUTLOOK CONTINUES
TO HAVE THE AREA HIGHLIGHTED IN A SLIGHT RISK. MODERATE DEEP SHEAR
AND SURFACE BASED INSTABILITY, HEIGHT FALLS FROM THE APPROACHING
MID- LEVEL TROUGH AND THE SURFACE FRONT WILL ALL BE CONTRIBUTORS
IN FAVOR OF THE THREATS OF BOTH LARGE HAIL AND DAMAGING WINDS THIS
AFTERNOON. THE ONE NEGATING FACTOR POSSIBLE IS CLOUD COVERAGE
EARLY IN THE DAY AS MID TO UPPER LEVEL CLOUDS FILTER INTO THE AREA
AHEAD OF DEVELOPING UPSTREAM CONVECTION.
WITH WARM AIR ADVECTION AHEAD OF THE COLD FRONT AND CLOUD COVERAGE
INCREASING, THIS MAKES FOR A CHALLENGING TEMP FORECAST TODAY. HIGH
TEMPS TODAY ARE CLOSEST TO THE WARMER MAV GUIDANCE, RANGING FROM
THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THERE IS ECMWF/GFS/NAM AGREEMENT THAT THE COLD FRONT WILL PUSH
EAST OF THE AREA TONIGHT AND USHER A DRIER AND MORE SEASONABLE AIR
MASS INTO THE AREA IN ITS WAKE. CONVECTION WILL MOSTLY DIMINISH THIS
EVENING, WITH SCHC OF THUNDER LINGERING UNTIL 06Z AND THE FORECAST
BECOMING DRY BY 12Z WED. LOWS TONIGHT ARE A MAV/MET BLEND, RANGING
FROM THE UPPER 50S TO LOWER 60S ACROSS THE AREA.
THERE IS SOME UNCERTAINTY ON WEDNESDAY IN REGARDS TO LINGERING
SHOWERS DEVELOPING EAST OF PITTSBURGH IN THE AFTERNOON. WEAK VORT
ENERGY CROSSING THE AREA IN A ZONAL MID-LEVEL FLOW MAY CONTRIBUTE
TO DIURNALLY DRIVEN SHOWERS ALONG THE RIDGES. CONFIDENCE IS LOW IN
THIS FEATURE CROSSING THE AREA, THUS, ONLY A SCHC OF SHOWERS ON
WEDNESDAY. COLD AIR ADVECTION ALOFT WILL BE ONGOING, WITH 850MB
TEMPS DECREASING TO 11-13C BY 00Z THURSDAY. DESPITE CAA, THE CORE
OF THE COOLEST WILL AIR REMAIN ACROSS THE GREAT LAKES ON THURSDAY
AND THUS HIGHS WILL BE AROUND 5 DEGREES ABOVE NORMAL. HIGH PRESSURE
WILL CROSS THE GREAT LAKES THURSDAY NIGHT AND AID IN RADIATIONAL
COOLING THAT WILL PROVIDE SEASONABLE TEMPERATURES FOR LOWS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
- SHARP COOL DOWN LATE WEEK INTO THE WEEKEND
- NEEDED RAINFALL FRIDAY AND SATURDAY
- WARMING TREND BACK TO SEASONAL VALUES BY SUNDAY
CONFIDENCE ABOVE AVERAGE FOR THE LONG RANGE WITH GOOD AGREEMENT
AMONGST THE GFS AND ECMWF OPERATIONAL MODELS AND THEIR RESPECTIVE
ENSEMBLE MEANS. BOTH RIDE A CYCLONE /-3 STANDARD DEVIATIONS OFF THE
GEFS/ UP THE OHIO VALLEY SPREADING WIDESPREAD RAINFALL TO THE AREA
FRIDAY INTO SATURDAY. THIS PATTERN IS MORE CHARACTERISTIC IN WINTER
AND SPRING THAN THE FIRST DAYS OF THE NEWLY INDOCTRINATED
METEOROLOGICAL SUMMER. RAISED POPS OVER THE ENTIRE AREA FRIDAY WITH
NUMBERS PUSHING 80% AS GIVEN BY THE CONSENSUS STATISTICAL GUIDANCE.
GEFS PLUMES AT PITTSBURGH INDICATE AROUND AN INCH OF RAINFALL WITH
THIS SYSTEM. AS THE LOW WEAKENS AS IT CONTINUES A NE TRAJECTORY
INTO SRN ONTARIO...GUSTY WINDS ARE NOT FORESEEN ON THE BACKSIDE AT
THIS JUNCTURE. DUE TO ABUNDANCE OF CLOUDS...LOOK FOR THE MERCURY TO
STAY IN THE 60S FOR MOST LOCATIONS FRIDAY AND SATURDAY.
EVEN WITH THE UPPER AIR SYSTEM EXODUS SATURDAY...A FULL LATITUDE
TROF DEVELOPS FOR THE BALANCE OF THE FORECAST. CONFIDENCE IN THE
OUT PERIODS /DAYS 6 AND 7/ DECREASES...BECAUSE OF WEAK IMPULSES
CROSSING AND THE TIMING CHALLENGES NEARLY 200 HRS IN THE FUTURE.
TEMPERATURES RETURN TO NORMAL BENCHMARKS FOR EARLY JUNE SUNDAY AND
MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THUNDERSTORMS CONTINUE TO THRIVE IN THE MOISTURE-LADEN ENVIRONMENT
ALONG AND AHEAD OF A COLD FRONT THAT EXTENDS FROM LONDON ONTARIO
TO ABOUT DAYTON OHIO AS OF 10Z. THE FRONT WILL CONTINUE TO EDGE
EASTWARD THROUGH THE MORNING HOURS...WITH EXTRAPOLATION GETTING TO
INTO AND THROUGH EACH TERMINAL JUST AN HOUR OR TWO FASTER THAN
PREVIOUSLY FORECAST. RADAR EXTRAPOLATION COMPARES FAVORABLY WITH
NAM OUTPUT...SO IT WAS LARGELY USED TO TIME THE LINE OF
THUNDERSTORMS THROUGH THE AREA. GUSTS/SQUALLS ARE LIKELY ALONG THE
FRONT AS IT PASSES...BUT WILL BE LARGELY DEPENDENT UPON HOW
COHERENT THE FRONT IS AS IT RUNS THROUGH THE AREA. AS A
RESULT...STRONG WINDS WERE NOT INCLUDED IN THE TAFS AT THE
MOMENT...HOWEVER THEY WILL LIKELY NEED TO BE CONSIDERED ONCE
THUNDERSTORMS GET CLOSER TO ANY OF THE SITES. FRIES
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
FRONT WILL PUSH EAST OF REGION BY TUESDAY NIGHT WITH IMPROVING
CONDITIONS TO GENERAL VFR. ON WEDNESDAY SECONDARY COLD FRONT WILL
CROSS REGION WITH ONLY A SLIGHT CHANCE FOR A SHOWER OR STORM WITH
GENERAL VFR. VFR THURSDAY UNDER SURFACE RIDGE. LOW PRESSURE
APPROACHES LATE THURSDAY NIGHT AND WILL SPREAD PRECIPITATION AND
RESTRICTIONS ACROSS REGION FRIDAY INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
619 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION TODAY, BRINGING SHOWERS AND
THUNDERSTORMS TO THE AREA. SOME OF THE STORMS COULD BECOME SEVERE. A
BREAK FROM SHOWERS AND STORMS IS ANTICIPATED FOR THE MID-WEEK
BEFORE A MORE ORGANIZED LOW PRESSURE SPREADS WIDESPREAD RAINFALL
AND MUCH COOLER WEATHER BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE HAS BEEN ISSUED THIS MORNING TO BRING IN LIKELY
POPS A FEW HOURS EARLIER IN EASTERN OHIO THIS MORNING. THIS TAKES
INTO ACCOUNT UPSTREAM CONVECTION AHEAD THAT IS MOVING INTO
WESTERN OHIO AHEAD OF A COLD FRONT. THE PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW AHEAD OF A TROUGH ACROSS THE UPPER
MIDWEST. AT THE SURFACE, A 1000MB LOW IS LOCATED NORTH OF LAKE
HURON WITH A COLD FRONT EXTENDING SOUTHWARD ACROSS MICHIGAN AND
INTO INDIANA. THIS FEATURE IS CONTRIBUTING TO AN ENHANCED SOUTHERLY
FLOW WITH WARM AIR ADVECTION KEEPING TEMPS AND DEW POINTS UP THIS
MORNING. TEMPS ARE IN THE LOWER TO MID 70S ACROSS MUCH OF THE AREA
WITH TDS IN THE MID TO UPPER 60S.
EARLY TODAY...THE COLD FRONT WILL CROSS THE OHIO VALLEY. WARM AND
HUMID CONDITIONS WILL CONTINUE THIS MORNING AHEAD OF THE COLD
FRONT. CLOUDS WILL BE ON THE INCREASE AS THE COLD FRONT CHARGES
EAST FROM THE GREAT LAKES. WITH MODERATE ELEVATED INSTABILITY, THE
ISOLATED DEVELOPMENT OF CONVECTION CANNOT BE RULED OUT EARLY IN EASTERN
OHIO.
THUNDERSTORMS WILL BECOME NUMEROUS WITH THE 4KM NAM SUPPORTING
DEVELOPMENT CONGEALING INTO AN MCS BY LATE AFTERNOON AS THE FRONT
WORKS INTO REGION. STRONG TO SEVERE THUNDERSTORMS ALONG AND AHEAD
OF THE COLD FRONT ARE ANTICIPATED TO REACH EASTERN OHIO BY 18Z AND
BY 21Z ACROSS WESTERN PA. THE LATEST SPC DAY 1 OUTLOOK CONTINUES
TO HAVE THE AREA HIGHLIGHTED IN A SLIGHT RISK. MODERATE DEEP SHEAR
AND SURFACE BASED INSTABILITY, HEIGHT FALLS FROM THE APPROACHING
MID- LEVEL TROUGH AND THE SURFACE FRONT WILL ALL BE CONTRIBUTORS
IN FAVOR OF THE THREATS OF BOTH LARGE HAIL AND DAMAGING WINDS THIS
AFTERNOON. THE ONE NEGATING FACTOR POSSIBLE IS CLOUD COVERAGE
EARLY IN THE DAY AS MID TO UPPER LEVEL CLOUDS FILTER INTO THE AREA
AHEAD OF DEVELOPING UPSTREAM CONVECTION.
WITH WARM AIR ADVECTION AHEAD OF THE COLD FRONT AND CLOUD COVERAGE
INCREASING, THIS MAKES FOR A CHALLENGING TEMP FORECAST TODAY. HIGH
TEMPS TODAY ARE CLOSEST TO THE WARMER MAV GUIDANCE, RANGING FROM
THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THERE IS ECMWF/GFS/NAM AGREEMENT THAT THE COLD FRONT WILL PUSH
EAST OF THE AREA TONIGHT AND USHER A DRIER AND MORE SEASONABLE AIR
MASS INTO THE AREA IN ITS WAKE. CONVECTION WILL MOSTLY DIMINISH THIS
EVENING, WITH SCHC OF THUNDER LINGERING UNTIL 06Z AND THE FORECAST
BECOMING DRY BY 12Z WED. LOWS TONIGHT ARE A MAV/MET BLEND, RANGING
FROM THE UPPER 50S TO LOWER 60S ACROSS THE AREA.
THERE IS SOME UNCERTAINTY ON WEDNESDAY IN REGARDS TO LINGERING
SHOWERS DEVELOPING EAST OF PITTSBURGH IN THE AFTERNOON. WEAK VORT
ENERGY CROSSING THE AREA IN A ZONAL MID-LEVEL FLOW MAY CONTRIBUTE
TO DIURNALLY DRIVEN SHOWERS ALONG THE RIDGES. CONFIDENCE IS LOW IN
THIS FEATURE CROSSING THE AREA, THUS, ONLY A SCHC OF SHOWERS ON
WEDNESDAY. COLD AIR ADVECTION ALOFT WILL BE ONGOING, WITH 850MB
TEMPS DECREASING TO 11-13C BY 00Z THURSDAY. DESPITE CAA, THE CORE
OF THE COOLEST WILL AIR REMAIN ACROSS THE GREAT LAKES ON THURSDAY
AND THUS HIGHS WILL BE AROUND 5 DEGREES ABOVE NORMAL. HIGH PRESSURE
WILL CROSS THE GREAT LAKES THURSDAY NIGHT AND AID IN RADIATIONAL
COOLING THAT WILL PROVIDE SEASONABLE TEMPERATURES FOR LOWS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
- SHARP COOL DOWN LATE WEEK INTO THE WEEKEND
- NEEDED RAINFALL FRIDAY AND SATURDAY
- WARMING TREND BACK TO SEASONAL VALUES BY SUNDAY
CONFIDENCE ABOVE AVERAGE FOR THE LONG RANGE WITH GOOD AGREEMENT
AMONGST THE GFS AND ECMWF OPERATIONAL MODELS AND THEIR RESPECTIVE
ENSEMBLE MEANS. BOTH RIDE A CYCLONE /-3 STANDARD DEVIATIONS OFF THE
GEFS/ UP THE OHIO VALLEY SPREADING WIDESPREAD RAINFALL TO THE AREA
FRIDAY INTO SATURDAY. THIS PATTERN IS MORE CHARACTERISTIC IN WINTER
AND SPRING THAN THE FIRST DAYS OF THE NEWLY INDOCTRINATED
METEOROLOGICAL SUMMER. RAISED POPS OVER THE ENTIRE AREA FRIDAY WITH
NUMBERS PUSHING 80% AS GIVEN BY THE CONSENSUS STATISTICAL GUIDANCE.
GEFS PLUMES AT PITTSBURGH INDICATE AROUND AN INCH OF RAINFALL WITH
THIS SYSTEM. AS THE LOW WEAKENS AS IT CONTINUES A NE TRAJECTORY
INTO SRN ONTARIO...GUSTY WINDS ARE NOT FORESEEN ON THE BACKSIDE AT
THIS JUNCTURE. DUE TO ABUNDANCE OF CLOUDS...LOOK FOR THE MERCURY TO
STAY IN THE 60S FOR MOST LOCATIONS FRIDAY AND SATURDAY.
EVEN WITH THE UPPER AIR SYSTEM EXODUS SATURDAY...A FULL LATITUDE
TROF DEVELOPS FOR THE BALANCE OF THE FORECAST. CONFIDENCE IN THE
OUT PERIODS /DAYS 6 AND 7/ DECREASES...BECAUSE OF WEAK IMPULSES
CROSSING AND THE TIMING CHALLENGES NEARLY 200 HRS IN THE FUTURE.
TEMPERATURES RETURN TO NORMAL BENCHMARKS FOR EARLY JUNE SUNDAY AND
MONDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/.
THUNDERSTORMS CONTINUE TO THRIVE IN THE MOISTURE-LADEN ENVIRONMENT
ALONG AND AHEAD OF A COLD FRONT THAT EXTENDS FROM LONDON ONTARIO
TO ABOUT DAYTON OHIO AS OF 10Z. THE FRONT WILL CONTINUE TO EDGE
EASTWARD THROUGH THE MORNING HOURS...WITH EXTRAPOLATION GETTING TO
INTO AND THROUGH EACH TERMINAL JUST AN HOUR OR TWO FASTER THAN
PREVIOUSLY FORECAST. RADAR EXTRAPOLATION COMPARES FAVORABLY WITH
NAM OUTPUT...SO IT WAS LARGELY USED TO TIME THE LINE OF
THUNDERSTORMS THROUGH THE AREA. GUSTS/SQUALLS ARE LIKELY ALONG THE
FRONT AS IT PASSES...BUT WILL BE LARGELY DEPENDENT UPON HOW
COHERENT THE FRONT IS AS IT RUNS THROUGH THE AREA. AS A
RESULT...STRONG WINDS WERE NOT INCLUDED IN THE TAFS AT THE
MOMENT...HOWEVER THEY WILL LIKELY NEED TO BE CONSIDERED ONCE
THUNDERSTORMS GET CLOSER TO ANY OF THE SITES. FRIES
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
FRONT WILL PUSH EAST OF REGION BY TUESDAY NIGHT WITH IMPROVING
CONDITIONS TO GENERAL VFR. ON WEDNESDAY SECONDARY COLD FRONT WILL
CROSS REGION WITH ONLY A SLIGHT CHANCE FOR A SHOWER OR STORM WITH
GENERAL VFR. VFR THURSDAY UNDER SURFACE RIDGE. LOW PRESSURE
APPROACHES LATE THURSDAY NIGHT AND WILL SPREAD PRECIPITATION AND
RESTRICTIONS ACROSS REGION FRIDAY INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
416 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY, BRINGING SHOWERS
AND THUNDERSTORMS. SOME OF THE STORMS COULD BECOME SEVERE. A BREAK
FROM SHOWERS AND STORMS IS ANTICIPATED FOR THE MID-WEEK BEFORE A
MORE ORGANIZED LOW PRESSURE SPREADS WIDESPREAD RAINFALL AND MUCH
COOLER WEATHER BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW AHEAD OF A TROUGH ACROSS THE UPPER
MIDWEST. AT THE SURFACE, A 1000MB LOW IS LOCATED NORTH OF LAKE
HURON WITH A COLD FRONT EXTENDING SOUTHWARD ACROSS MICHIGAN AND
INTO INDIANA. THIS FEATURE IS CONTRIBUTING TO AN ENHANCED SOUTHERLY
FLOW WITH WARM AIR ADVECTION KEEPING TEMPS AND DEW POINTS UP THIS
MORNING. TEMPS ARE IN THE LOWER TO MID 70S ACROSS MUCH OF THE AREA
WITH TDS IN THE MID TO UPPER 60S.
EARLY TODAY...THE COLD FRONT WILL CROSS THE OHIO VALLEY. WARM AND
HUMID CONDITIONS WILL CONTINUE THIS MORNING AHEAD OF THE COLD
FRONT. CLOUDS WILL BE ON THE INCREASE AS THE COLD FRONT CHARGES
EAST FROM THE GREAT LAKES. WITH MODERATE ELEVATED INSTABILITY, THE
ISOLATED DEVELOPMENT OF CONVECTION CANNOT BE RULED OUT EARLY IN EASTERN
OHIO.
THUNDERSTORMS WILL BECOME NUMEROUS WITH THE 4KM NAM SUPPORTING
DEVELOPMENT CONGEALING INTO AN MCS BY LATE AFTERNOON AS THE FRONT
WORKS INTO REGION. STRONG TO SEVERE THUNDERSTORMS ALONG AND AHEAD
OF THE COLD FRONT ARE ANTICIPATED TO REACH EASTERN OHIO BY 18Z AND
BY 21Z ACROSS WESTERN PA. THE LATEST SPC DAY 1 OUTLOOK CONTINUES
TO HAVE THE AREA HIGHLIGHTED IN A SLIGHT RISK. MODERATE DEEP SHEAR
AND SURFACE BASED INSTABILITY, HEIGHT FALLS FROM THE APPROACHING
MID- LEVEL TROUGH AND THE SURFACE FRONT WILL ALL BE CONTRIBUTORS
IN FAVOR OF THE THREATS OF BOTH LARGE HAIL AND DAMAGING WINDS THIS
AFTERNOON. THE ONE NEGATING FACTOR POSSIBLE IS CLOUD COVERAGE
EARLY IN THE DAY AS MID TO UPPER LEVEL CLOUDS FILTER INTO THE AREA
AHEAD OF DEVELOPING UPSTREAM CONVECTION.
WITH WARM AIR ADVECTION AHEAD OF THE COLD FRONT AND CLOUD COVERAGE
INCREASING, THIS MAKES FOR A CHALLENGING TEMP FORECAST TODAY. HIGH
TEMPS TODAY ARE CLOSEST TO THE WARMER MAV GUIDANCE, RANGING FROM
THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
THERE IS ECMWF/GFS/NAM AGREEMENT THAT THE COLD FRONT WILL PUSH
EAST OF THE AREA TONIGHT AND USHER A DRIER AND MORE SEASONABLE AIR
MASS INTO THE AREA IN ITS WAKE. CONVECTION WILL MOSTLY DIMINISH THIS
EVENING, WITH SCHC OF THUNDER LINGERING UNTIL 06Z AND THE FORECAST
BECOMING DRY BY 12Z WED. LOWS TONIGHT ARE A MAV/MET BLEND, RANGING
FROM THE UPPER 50S TO LOWER 60S ACROSS THE AREA.
THERE IS SOME UNCERTAINTY ON WEDNESDAY IN REGARDS TO LINGERING
SHOWERS DEVELOPING EAST OF PITTSBURGH IN THE AFTERNOON. WEAK VORT
ENERGY CROSSING THE AREA IN A ZONAL MID-LEVEL FLOW MAY CONTRIBUTE
TO DIURNALLY DRIVEN SHOWERS ALONG THE RIDGES. CONFIDENCE IS LOW IN
THIS FEATURE CROSSING THE AREA, THUS, ONLY A SCHC OF SHOWERS ON
WEDNESDAY. COLD AIR ADVECTION ALOFT WILL BE ONGOING, WITH 850MB
TEMPS DECREASING TO 11-13C BY 00Z THURSDAY. DESPITE CAA, THE CORE
OF THE COOLEST WILL AIR REMAIN ACROSS THE GREAT LAKES ON THURSDAY
AND THUS HIGHS WILL BE AROUND 5 DEGREES ABOVE NORMAL. HIGH PRESSURE
WILL CROSS THE GREAT LAKES THURSDAY NIGHT AND AID IN RADIATIONAL
COOLING THAT WILL PROVIDE SEASONABLE TEMPERATURES FOR LOWS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGHLIGHTS...
- SHARP COOL DOWN LATE WEEK INTO THE WEEKEND
- NEEDED RAINFALL FRIDAY AND SATURDAY
- WARMING TREND BACK TO SEASONAL VALUES BY SUNDAY
CONFIDENCE ABOVE AVERAGE FOR THE LONG RANGE WITH GOOD AGREEMENT
AMONGST THE GFS AND ECMWF OPERATIONAL MODELS AND THEIR RESPECTIVE
ENSEMBLE MEANS. BOTH RIDE A CYCLONE /-3 STANDARD DEVIATIONS OFF THE
GEFS/ UP THE OHIO VALLEY SPREADING WIDESPREAD RAINFALL TO THE AREA
FRIDAY INTO SATURDAY. THIS PATTERN IS MORE CHARACTERISTIC IN WINTER
AND SPRING THAN THE FIRST DAYS OF THE NEWLY INDOCTRINATED
METEOROLOGICAL SUMMER. RAISED POPS OVER THE ENTIRE AREA FRIDAY WITH
NUMBERS PUSHING 80% AS GIVEN BY THE CONSENSUS STATISTICAL GUIDANCE.
GEFS PLUMES AT PITTSBURGH INDICATE AROUND AN INCH OF RAINFALL WITH
THIS SYSTEM. AS THE LOW WEAKENS AS IT CONTINUES A NE TRAJECTORY
INTO SRN ONTARIO...GUSTY WINDS ARE NOT FORESEEN ON THE BACKSIDE AT
THIS JUNCTURE. DUE TO ABUNDANCE OF CLOUDS...LOOK FOR THE MERCURY TO
STAY IN THE 60S FOR MOST LOCATIONS FRIDAY AND SATURDAY.
EVEN WITH THE UPPER AIR SYSTEM EXODUS SATURDAY...A FULL LATITUDE
TROF DEVELOPS FOR THE BALANCE OF THE FORECAST. CONFIDENCE IN THE
OUT PERIODS /DAYS 6 AND 7/ DECREASES...BECAUSE OF WEAK IMPULSES
CROSSING AND THE TIMING CHALLENGES NEARLY 200 HRS IN THE FUTURE.
TEMPERATURES RETURN TO NORMAL BENCHMARKS FOR EARLY JUNE SUNDAY AND
MONDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
UPSTREAM CONVECTION CONTINUES TO DEVELOP THIS EVENING...AS NEAR AS
THE EASTERN END OF LAKE ERIE. HOWEVER...INSTABILITY SHOULD REMAIN
TO THE WEST OF ALL SITES THROUGH THE NIGHT...WITH ONLY CONVECTIVE
DEBRIS CLOUDS AT HIGHER LEVELS MOVING OVER THE SITES THROUGH THE
REST OF THE NIGHT. INSTABILITY AND AN EASTERLY ADVANCING COLD
FRONT SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO PUSH ACROSS ALL
SITES ON TUESDAY BETWEEN ROUGHLY 17Z AND 22Z...WITH THUNDERSTORMS
LIKELY FOR A PERIOD AT ALL SITES. SOME STRONG WIND GUSTS AND HAIL
ARE POSSIBLE AT ANY GIVEN SITE...HOWEVER TIMING IS TOO UNCERTAIN
TO PINPOINT AT THIS TIME. SKIES SHOULD QUICKLY CLEAR BEHIND THE
FRONT AS EVENING ENSUES ON TUESDAY. FRIES
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
FRONT WILL PUSH EAST OF REGION BY TUESDAY NIGHT WITH IMPROVING
CONDITIONS TO GENERAL VFR. ON WEDNESDAY SECONDARY COLD FRONT WILL
CROSS REGION WITH ONLY A SLIGHT CHANCE FOR A SHOWER OR STORM WITH
GENERAL VFR. VFR THURSDAY UNDER SURFACE RIDGE. LOW PRESSURE
APPROACHES LATE THURSDAY NIGHT AND WILL SPREAD PRECIPITATION AND
RESTRICTIONS ACROSS REGION FRIDAY INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
228 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY, BRINGING SHOWERS
AND THUNDERSTORMS. SOME OF THE STORMS COULD BECOME SEVERE. A BREAK
FROM SHOWERS AND STORMS IS ANTICIPATED FOR THE MID-WEEK BEFORE A
MORE ORGANIZED LOW PRESSURE SPREADS WIDESPREAD RAINFALL AND MUCH
COOLER WEATHER BY WEEKS END.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED IN ORDER
TO MAKE ADJUSTMENTS TO SKY AND POP GRIDS THIS MORNING.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW AHEAD OF A TROUGH ACROSS THE UPPER
MIDWEST. AT THE SURFACE, A 1000MB LOW IS LOCATED NORTH OF LAKE
HURON WITH A COLD FRONT EXTENDING SOUTHWARD ACROSS MICHIGAN AND
INTO ILLINOIS. THIS FEATURE IS CONTRIBUTED TO AN ENHANCED
SOUTHERLY FLOW WITH WARM AIR ADVECTION KEEPING TEMPS AND DEW
POINTS FROM DROPPING OFF OVERNIGHT. THUS, TEMPS ARE IN THE LOWER
TO MID 70S ACROSS MUCH OF THE AREA WITH TDS IN THE MID TO UPPER
60S. TEMPS WILL ONLY DROP A FEW MORE DEGREES, WITH A MUGGY MORNING
ANTICIPATED ACROSS THE AREA.
TODAY...WARM AND HUMID CONDITIONS WILL CONTINUE THIS MORNING
AHEAD OF AN APPROACHING COLD FRONT. CLOUDS WILL BE ON THE
INCREASE EARLY TODAY AS THE COLD FRONT CHARGES EAST FROM THE GREAT
LAKES. WITH MODERATE ELEVATED INSTABILITY, THE ISOLATED
DEVELOPMENT OF CONVECTION CANNOT BE RULED OUT IN EASTERN OHIO BY
DAWN. SHOWERS AND THUNDERSTORMS WILL BECOME NUMEROUS AND MESOSCALE
MODELS ARE HINTING AT CONVECTION CONGEALING INTO AN MCS BY LATE
AFTERNOON AS THE FRONT WORKS INTO REGION. STRONG TO SEVERE
THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT ARE ANTICIPATED TO
REACH EASTERN OHIO BY 18Z AND BY 21Z ACROSS WESTERN PA. THE LATEST
SPC DAY 1 OUTLOOK CONTINUES TO HAVE THE AREA HIGHLIGHTED IN A
SLIGHT RISK. MODERATE DEEP SHEAR AND SURFACE BASED INSTABILITY,
HEIGHT FALLS FROM THE APPROACHING MID- LEVEL TROUGH AND THE
SURFACE FRONT WILL ALL BE CONTRIBUTORS IN FAVOR OF THE THREATS OF
BOTH LARGE HAIL AND DAMAGING WINDS THIS AFTERNOON. THE ONE
NEGATING FACTOR POSSIBLE IS CLOUD COVERAGE EARLY IN THE DAY AS MID
TO UPPER LEVEL CLOUDS FILTER INTO THE AREA AHEAD OF DEVELOPING
UPSTREAM CONVECTION.
WITH WARM AIR ADVECTION AHEAD OF THE COLD FRONT AND CLOUD COVERAGE
INCREASING, THIS MAKES FOR A CHALLENGING TEMP FORECAST TODAY. HIGH
TEMPS TODAY ARE CLOSEST TO THE WARMER MAV GUIDANCE, RANGING FROM
THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
WHATEVER ACTIVITY IS ASSOCIATED WITH THE BAROCLINIC ZONE PASSAGE
TUESDAY AFTERNOON...WILL AT A MINIMUM BE EAST OF THE OHIO RIVER BY
0Z WED. ALL AREAS SHOULD BE DRY BY MIDNIGHT AS DRIER / MORE STABLE
AIR FILTERS IN FROM THE WEST. A SECONDARY FRONT ASSOCIATED WITH THE
UPPER LEVEL TROUGH SWEEPS THROUGH WEDNESDAY AFTERNOON AND EVENING.
DESPITE ITS PASSAGE DURING PEAK HEATING HOURS...THERMODYNAMIC
INSTABILITY IS WEAK DESPITE MODEST KINEMATICS...SO NOT EXPECTING ANY
STORM TO BECOME `PLUGGED IN` /I.E. CONTAINING LIGHTNING/ SO ROLLED
WITH JUST SHOWERS. INCREASED POPS TO SCHC OUTSIDE THE MOUNTAINS
WITH CHC NUMBERS FOR HIGHER ELEVATIONS.
DRY WEATHER RETURNS THURSDAY UNDER A TRANSITORY MID LEVEL RIDGE.
THERE COULD BE A SHARP MAXT GRADIENT THUR AFTN AS H8 TEMPS GO FROM
8C OVER THE FAR NRN PART OF THE CWA / FOREST COUNTY/ TO 15C S OF THE
MASON DIXON LINE. RIGHT NOW...ROLLING WITH MID 60S N TO MID 70S S.
ATMOSPHERIC COLUMN QUICKLY SATURATES THURSDAY NIGHT AS MOISTURE
ADVECTION SURGES NE FROM THE LOWER OHIO RIVER VALLEY ASSOCIATED WITH
LOW PRESSURE. LOCATIONS WEST OF THE OHIO RIVER HAVE THE HIGHEST
PROBABILITY OF MEASURABLE RAINFALL PRIOR TO DAWN FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGHLIGHTS...
- SHARP COOL DOWN LATE WEEK INTO THE WEEKEND
- NEEDED RAINFALL FRIDAY AND SATURDAY
- WARMING TREND BACK TO SEASONAL VALUES BY SUNDAY
CONFIDENCE ABOVE AVERAGE FOR THE LONG RANGE WITH GOOD AGREEMENT
AMONGST THE GFS AND ECMWF OPERATIONAL MODELS AND THEIR RESPECTIVE
ENSEMBLE MEANS. BOTH RIDE A CYCLONE /-3 STANDARD DEVIATIONS OFF THE
GEFS/ UP THE OHIO VALLEY SPREADING WIDESPREAD RAINFALL TO THE AREA
FRIDAY INTO SATURDAY. THIS PATTERN IS MORE CHARACTERISTIC IN WINTER
AND SPRING THAN THE FIRST DAYS OF THE NEWLY INDOCTRINATED
METEOROLOGICAL SUMMER. RAISED POPS OVER THE ENTIRE AREA FRIDAY WITH
NUMBERS PUSHING 80% AS GIVEN BY THE CONSENSUS STATISTICAL GUIDANCE.
GEFS PLUMES AT PITTSBURGH INDICATE AROUND AN INCH OF RAINFALL WITH
THIS SYSTEM. AS THE LOW WEAKENS AS IT CONTINUES A NE TRAJECTORY
INTO SRN ONTARIO...GUSTY WINDS ARE NOT FORESEEN ON THE BACKSIDE AT
THIS JUNCTURE. DUE TO ABUNDANCE OF CLOUDS...LOOK FOR THE MERCURY TO
STAY IN THE 60S FOR MOST LOCATIONS FRIDAY AND SATURDAY.
EVEN WITH THE UPPER AIR SYSTEM EXODUS SATURDAY...A FULL LATITUDE
TROF DEVELOPS FOR THE BALANCE OF THE FORECAST. CONFIDENCE IN THE
OUT PERIODS /DAYS 6 AND 7/ DECREASES...BECAUSE OF WEAK IMPULSES
CROSSING AND THE TIMING CHALLENGES NEARLY 200 HRS IN THE FUTURE.
TEMPERATURES RETURN TO NORMAL BENCHMARKS FOR EARLY JUNE SUNDAY AND
MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
UPSTREAM CONVECTION CONTINUES TO DEVELOP THIS EVENING...AS NEAR AS
THE EASTERN END OF LAKE ERIE. HOWEVER...INSTABILITY SHOULD REMAIN
TO THE WEST OF ALL SITES THROUGH THE NIGHT...WITH ONLY CONVECTIVE
DEBRIS CLOUDS AT HIGHER LEVELS MOVING OVER THE SITES THROUGH THE
REST OF THE NIGHT. INSTABILITY AND AN EASTERLY ADVANCING COLD
FRONT SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO PUSH ACROSS ALL
SITES ON TUESDAY BETWEEN ROUGHLY 17Z AND 22Z...WITH THUNDERSTORMS
LIKELY FOR A PERIOD AT ALL SITES. SOME STRONG WIND GUSTS AND HAIL
ARE POSSIBLE AT ANY GIVEN SITE...HOWEVER TIMING IS TOO UNCERTAIN
TO PINPOINT AT THIS TIME. SKIES SHOULD QUICKLY CLEAR BEHIND THE
FRONT AS EVENING ENSUES ON TUESDAY. FRIES
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
FRONT WILL PUSH EAST OF REGION BY TUESDAY NIGHT WITH IMPROVING
CONDITIONS TO GENERAL VFR. ON WEDNESDAY SECONDARY COLD FRONT WILL
CROSS REGION WITH ONLY A SLIGHT CHANCE FOR A SHOWER OR STORM WITH
GENERAL VFR. VFR THURSDAY UNDER SURFACE RIDGE. LOW PRESSURE
APPROACHES LATE THURSDAY NIGHT AND WILL SPREAD PRECIPITATION AND
RESTRICTIONS ACROSS REGION FRIDAY INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 PM EDT WED MAY 30 2012
.UPDATE...
ISSUED AT 728 PM EDT WED MAY 30 2012
PERSISTENT CLOUDS CONTINUE TO SLOWLY DIMINISH OVER THE CWA THIS
EVENING. THEY HAVE BEEN THE THICKEST OVER THE WCNTRL/SCNTRL PORTION
OF THE AREA AND MAY EVEN BE PRODUCING A FEW SPRINKLES OVER NRN
MENOMINEE COUNTY. RAP RUNS CONTINUE TO HAVE THE BEST HANDLE ON THESE
CLOUDS ON THE 0.5-1KM LAYER AND WITH THE LOSS OF DIURNAL
HEATING...EXPECT THEM TO QUICKLY DIMINISH WHILE PUSHING S. DID DELAY
THE EXIT CLOSER TO MIDNIGHT OVER THE SCNTRL.
WITH THE CLOUDS DIMINISHING AND COOL DRY AIR IN PLACE...PWAT VALUES
AROUND 35 PERCENT OF NORM...EXPECT TEMPS TO QUICKLY FALL AFTER
SUNSET WHERE SKIES ARE CLEAR. HAVE SOME CONCERN THAT THE INITIAL
CLEAR SKIES OVER THE EAST WILL ALLOW SOME OF THE TRADITIONAL COLD
SPOTS TO NEAR FREEZE WARN CRITERIA...28 DEGREES FOR 3HRS. BUT
LINGERING WINDS ALOFT MAY PROVIDE JUST ENOUGH MIXING TO KEEP TEMPS
AT OR SLIGHTLY ABOVE. THUS...WILL LEAVE HEADLINES AS IS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
CURRENTLY...THERE IS AN UPPER TROUGH DRAPED N OF THE CWA...WITH SFC
RIDGING PUSHING IN FROM THE W. NW LOW LEVEL WINDS COMBINED WITH
LINGERING LOW LEVEL MOISTURE AND COOLER 850MB TEMPS AROUND -2C HAS
LEAD TO CLOUDS OVER THE AREA TODAY...BUT THE CLOUD COVER IS AND WILL
CONTINUE TO DIMINISH THROUGH THIS AFTERNOON AND EVENING. THE UPPER
TROUGH WILL MOVE TO THE CENTER OF THE CWA BETWEEN 12Z AND 18Z
THU...WITH THE SFC RIDGE MOVING FARTHER INTO THE CWA THROUGH THE
NIGHT. THIS LEADS TO CLEARING SKIES AS MUCH DRIER AIR MOVES
OVERHEAD...SO TEMPS WILL BE COLD TONIGHT SEEING AS HOW HIGH TEMPS
LATE THIS AFTERNOON INTO THIS EVENING WILL BE IN THE MID 40S TO MID
50S. EXPECT WIDESPREAD FROST OVER ALL BUT THE KEWEENAW
PENINSULA...MAINLY INLAND FROM THE GREAT LAKES WHERE TEMPS WILL FALL
INTO THE UPPER 20S...COLDEST OVER THE INTERIOR WEST AND CENTRAL.
THE SWRN EXTENT OF THE UPPER TROUGH DEEPENS OVER SW WI BY 00Z FRI IN
RESPONSE TO AN UPPER JET MOVING IN FROM THE NRN PLAINS. AT THE SAME
TIME...A W-E ORIENTED UPPER RIDGE WILL PUSH TO FAR NRN LAKE
SUPERIOR. HOWEVER...MOST OF THE CLOUDS AND ALL OF THE PRECIP FROM
THIS SYSTEM AS IS STRENGTHENS WILL STAY S OF THE CWA THU. 850MB
TEMPS WILL INCREASE TO A CWA AVG VALUE OF AROUND 5C BY 00Z
FRI...WHICH WILL ALLOW FOR WARMER HIGH TEMPS IN THE 50S NEAR LAKE
SUPERIOR...AND IN THE 60S INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
IN THE LONGER TERM...INITIAL FOCUS OF FCST WILL BE ON RAIN POTENTIAL
FRI/SAT AS SYSTEM LIFTS THRU LWR MI...POSSIBLY BRUSHING THE FCST
AREA WITH RAIN SHIELD. FARTHER DOWN THE LINE...PATTERN SHOULD
OVERALL SUPPORT DRY WEATHER AS MID/UPPER RIDGE BUILDS THRU CNTRL
NAMERICA.
BEGINNING THU NIGHT...SHORTWAVE DROPPING INTO THE MIDWEST WILL
DEEPEN INTO A MIDLEVEL LOW CENTERED VCNTY OF CHICAGO BY FRI MORNING.
UPPER MI REMAINS UNDER SFC RIDGING N OF SYSTEM...SO DRY WEATHER IS
EXPECTED THU NIGHT. SHOULD SEE AN INCREASE IN HIGH CLOUDS EXPANDING
N FROM THE ORGANIZING SYSTEM TO THE S. NONETHELESS...LIGHT/CALM WIND
AND PRECIPITABLE WATER 40-60PCT OF NORMAL SUGGEST FAVORING THE LOWER
END OF GUIDANCE. FROST MAY BE AN ISSUE IN THE TYPICAL COLD SPOTS...
DEPENDING ON HOW QUICKLY HIGH CLOUDS INCREASE.
SYSTEM ORGANIZING TO THE S THU NIGHT WILL TRACK THRU THE GREAT LAKES
REGION FRI/SAT. AFTER SHOWING A NW TREND TO SYSTEM YESTERDAY...
MODELS HAVE SETTLED TOWARD A MID LEVEL LOW TRACK ACROSS LWR MI AND
TOWARD JAMES BAY. TRACK IS FAR ENOUGH TO THE E THAT ONLY THE ERN
FCST AREA MAY GET BRUSHED BY ITS PCPN SHIELD FRI INTO SAT. AT THIS
POINT...CHC POPS STILL LOOK ON TRACK...BUT WILL TRIM WRN EXTENT OF
POPS E TO ROUGHLY A MUNISING/MENOMINEE LINE.
SUN THRU WED...MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN
AMPLIFYING CNTRL NAMERICA RIDGE NEXT WEEK AS A RIDGE OVER THE
ROCKIES THIS WEEKEND DRIFTS E AND MERGES WITH A POSITIVE ANOMALY
RETROGRADING FROM THE DAVIS STRAIT. A TROF WILL BE SITUATED OVER THE
WRN CONUS WITH A DEEPER TROF OVER THE NE. RESULT WILL BE NWRLY FLOW
GRADUALLY BECOMING NRLY BY THE MIDDLE OF THE WEEK AS RIDGE SHARPENS
JUST TO THE W. PATTERN SHOULD TEND TO FAVOR DRIER CONDITIONS HERE
WITH BUILDING MIDLEVEL RIDGE TO THE W AND NW SUPPORTING SFC HIGH
PRES GRADUALLY EXPANDING S FROM NCNTRL CANADA/HUDSON BAY INTO THE
GREAT LAKES REGION. HOWEVER...SUMMERTIME NWRLY FLOW CAN OFTEN LEAD
TO SCT DIURNAL CONVECTION WITH ANY MINOR SHORTWAVE PROGRESSING THRU
THE FLOW. TO SOME EXTENT...MEDIUM RANGE GUIDANCE OVER THE LAST FEW
DAYS HAS SUGGESTED THAT POTENTIAL. ALTHOUGH NOT WELL AGREED UPON...
THERE HAS BEEN A SIGNAL IN RECENT DAYS FOR A SHORTWAVE TO PASS THRU
THE AREA MON...SO FCST WILL CONTINUE TO INCLUDE LOW POPS LATE SUN
INTO MON. LATEST MODEL RUNS APPEAR TO BE TRENDING AWAY FROM THIS
SHORTWAVE CUTTING THRU THE BUILDING RIDGE AND INTO THE UPPER
LAKES...SO POPS HAVE BEEN DROPPED MOSTLY TO SLIGHT CHC. BEYOND
MON...SINCE THE EXPECTED PATTERN DOES NOT FAVOR ORGANIZED PCPN
EVENTS...PLAN TO KEEP FCST ON THE DRY SIDE GIVEN THE VERY LOW
PREDICTABILITY AT THIS TIME RANGE OF ANY MINOR SHORTWAVES AND
ASSOCIATED POTENTIAL SCT PCPN. WITH SFC HIGH PRES SLOWLY BUILDING S
FROM NRN CANADA...THERE SHOULD BE A WIND COMPONENT OFF LAKE SUPERIOR
MOST DAYS TO KEEP LAKESIDE LOCATIONS ON THE COOLER SIDE. INLAND...
TEMPS SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL FOR EARLY JUNE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 719 PM EDT WED MAY 30 2012
HIGH PRESSURE AND ASSOC DRIER AIR CONTINUES TO WORK IN FROM THE
WEST...PUSHING LAKE ENHANCED CLOUDS FURTHER TO THE SOUTHEAST. EXPECT
THEM TO COMPLETELY DIMINISH AS DAYTIME HEATING SUBSIDES THIS
EVENING...THOUGH A FEW LINGERING CLOUDS COULD BE POSSIBLE ON THE
PERIPHERY OF THE TAF SITES DURING THE FIRST FEW HOURS OF THE TAF
PERIOD. OTHERWISE EXPECT LIGHT WINDS AND VFR CONDITIONS TO PREVAIL
DURING THE REMAINDER OF THE TAF PERIOD AS HIGH PRESSURE AND
ASSOCIATED DRY AIR REMAIN OVER THE UPPER GREAT LAKE REGION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 439 PM EDT WED MAY 30 2012
GUSTY WINDS WILL CONTINUE TO DIMINISH FROM W TO E THIS EVENING AS
HIGH PRES BUILDS INTO THE UPPER LAKES. BY LATE TONIGHT...WINDS WILL
BE UNDER 15KT. WINDS WILL REMAIN MOSTLY UNDER 15KT THRU THU AND INTO
FRI AFTN. WINDS MAY INCREASE A LITTLE FRI NIGHT AND SAT OVER EASTERN
LAKE SUPERIOR AS LOW PRES MOVES NE THRU THE CNTRL GREAT LAKES
REGION. OTHERWISE...WINDS WILL GENERALLY REMAIN ON THE LIGHT SIDE
INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 8 AM EDT
/7 AM CDT/ THURSDAY FOR MIZ002-004>007-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...JMW
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
433 PM EDT TUE MAY 29 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT TUE MAY 29 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM NRN
ONTARIO INTO THE UPPER GREAT LAKES. VORT MAX TRACKING ACROSS LAKE
SUPERIOR COMBINED WITH DAYTIME HEATING HAS RESULTED IN SCT -SHRA
ACROSS UPPER MI THIS AFTN. WITH LOW FREEZING LEVELS (5700FT MSL ON
12Z KINL SOUNDING) MORE VIGOROUS CONVECTION HAS PROBABLY BEEN
PRODUCING PEA SIZE HAIL. SPOTTER REPORTED PEA SIZE HAIL AROUND
WAKEFIELD EARLIER IN THE DAY. A FEW LIGHTNING STRIKES HAVE BEEN
DETECTED ACROSS UPPER MI THIS AFTN.
AS VORT MAX SHIFTS E THIS EVENING AND DAYTIME HEATING IS LOST...THE
DIURNALLY DRIVEN -SHRA WILL DISSIPATE. HOWEVER...COOL CYCLONIC FLOW
ALONG WITH SFC TROF PASSING THRU THE AREA SHOULD RESULT IN SOME
-RA/-SHRA THRU THE NIGHT GIVEN CURRENT UPSTREAM RADAR RETURNS N AND
NW OF LAKE SUPERIOR. WITH 850MB TEMPS FALLING TO AROUND -3C MAY SEE
A LITTLE LAKE ENHANCEMENT IN THE UPSLOPE AREAS NEAR LAKE SUPERIOR.
ALSO...GIVEN THE SUBZERO C 850MB TEMPS AND 1000-850MB THICKNESS
FALLING JUST UNDER 1305M...NOT OUT OF THE QUESTION THAT THERE COULD
BE A LITTLE FROZEN PCPN AT TIMES OVER THE HIGH TERRAIN (IT WAS
SNOWING AT CYPL THIS MORNING).
TEMPS WED WILL BE WELL BLO NORMAL WITH 850MB THERMAL TROF PASSING
ACROSS THE AREA DURING THE FIRST HALF OF THE DAY. WITH THE 850MB
TROF OVER THE AREA...EXPECT ABUNDANT CLOUD COVER THRU THE MORNING
HRS. ALSO...SOME LIGHT -RA/-SHRA WILL PROBABLY LINGER NEAR LAKE
SUPERIOR IN THE MORNING. CLEARING WILL THEN BEGIN IN THE AFTN FROM
NW TO SE AS WAA STARTS TO GET UNDERWAY AND LOW-LEVEL FLOW BECOMES
ANTICYCLONIC. MOST AREAS SHOULD BE SUNNY BY LATE AFTN. TEMPS WILL
NOT GET OUT OF THE MID 40S NEAR LAKE SUPERIOR E OF KMQT UNDER CHILLY
AIR MASS AND GRADIENT FLOW ACROSS THE LAKE. LOW/MID 50S WILL BE THE
RULE ELSEWHERE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 432 PM EDT TUE MAY 29 2012
HIGH PRESSURE WILL BE OVER THE CWA ON WED NIGHT. NNE WINDS SHOULD
DIMINISH/DECOUPLE OVERNIGHT AND WITH PWATS AROUND 40 PERCENT OF
NORMAL...SHOULD LEAD TO A COLD NIGHT ACROSS MUCH OF THE CWA. HIGHER
RES MODELS TRYING TO KEEP LINGERING NW WINDS UP OVER THE ERN
CWA...WHICH MAY LIMIT THE COOLING IN THE MORE OPEN LOCATIONS.
WIDESPREAD FROST IS LIKELY OVER THE INTERIOR WEST...WHERE LOWS WILL
BE 28-31...WITH PATCHY/AREAS OF FROST ELSEWHERE AWAY FROM THE GREAT
LKS SHORELINE. MORE THAN LIKELY WILL NEED FROST ADVISORY OVER MUCH
OF THE CWA WED NIGHT AND POTENTIALLY A FREEZE WARNING OVER THE
INTERIOR WEST. CURRENT FORECAST DOESN/T QUITE REACH A HARD FREEZE
CRITERIA...28 DEGREES FOR 3HRS...SO WILL NOT ISSUE A WATCH.
WITH HIGH PRESSURE OVERHEAD AND DRIFTING SE ON THURS...EXPECT A
NICE DAY ACROSS UPPER MI WITH LK BREEZES AND DIURNAL CU THE MAIN
CONCERNS. MOISTURE SLIGHTLY LIMITED...BUT MAY BE ENOUGH FORCING
FROM LK BREEZES AND DIURNAL HEATING TO PRODUCE SOME CLOUDS ALONG THE
LK BREEZES. EXPECT LK BREEZES TO DEVELOP ALONG LK SUPERIOR/MICHIGAN
DURING THE EARLY AFTN...AND LEAD TO COOLING TEMPERATURES NEAR THE
GREAT LKS. BUT WITH THE SUN...SHOULD STILL SEE A QUICK WARM-UP FROM
THE FROSTY TEMPS TO START THE DAY. MIXING TO H800 WOULD YIELD HIGHS
IN THE MID 60S OVER THE INTERIOR LOCATIONS NOT INFLUENCED BY LK
BREEZES. FINALLY...COULD BE SOME HIGH CLOUDS BRUSHING THE WI BORDER
DURING THE AFTN AND ASSOCIATED WITH THE SYSTEM DROPPING THROUGH THE
UPPER/CNTRL MISS VALLEY. THIS SYSTEM WILL BE THE NEXT CONCERN FOR
THE CWA HEADING INTO FRI.
SHORTWAVE ROUNDING THE BASE OF THE TROUGH ON THURS NIGHT WILL HELP
SHARPEN THE TROUGH AND PUSH THE LOW FROM THE OHIO RIVER VALLEY AT
00Z FRI...NNE TO NEAR THE MACKINAC STRAITS AT 00Z SAT. SOME
DIFFERENCES IN THE INTENSITY AND LOCATION OF THE LOW...WITH 12Z GFS
THE STRONGEST AND THE MIDDLE GROUND BETWEEN THE FARTHER N 00Z ECMWF
AND THE WEAKER/SE TRACK OF THE 12Z NAM. PREFER A GENERAL
CONCENSUS OF THE 12Z GFS/GEM AND 00Z ECMWF...WHICH LOOKS MORE LIKE
SOMETHING THAT WOULD BE SEEN IN LATE WINTER OR EARLY SPRING. DUE
TO THE MORE ROBUST AND NORTHERN TRENDS IN THE MODELS OVER
THE LAST DAY...PREVIOUS SHIFT TRENDED IN THE RIGHT DIRECTION ON
CLOUD/POPS. HAVE FOLLOWED SUIT AND BUMPED POPS UP TO LIKELY OVER THE
ERN HALF OF THE CWA ON FRI...AS THE BEST H850-700 WAA PUSHES NNE
THROUGH THE ERN CWA.
FOR THE EXTENDED /FRI NIGHT THROUGH NEXT TUESDAY/...
THE FIRST PART OF THE EXTENDED WILL LARGELY DEPEND ON THE EVOLUTION
OF THE UPPER TROUGH ROTATING THROUGH THE GREAT LKS AND OHIO RIVER
VALLEY. MODELS STILL IN SOME DISAGREEMENT IN THE HANDLING OF THIS
TROUGH...BUT ALL INDICATE THE TROUGH LIFTING NE ON FRI NIGHT AND
INTO SAT. THIS SHOULD LEAD TO SCATTERED SHOWERS DIMINISHING FROM SW
TO NE AS THE TROUGH LIFTS TO THE NE INTO CANADA. THESE TIMING
DIFFERENCES CONTINUE INTO THE BEGINNING OF NEXT WEEK. GENERAL IDEA
OF WEAK HIGH PRESSURE RIDGE LEADING TO DRY WEATHER FOR 12-18HRS
BEHIND THE LOW BEFORE NEXT WAVE APPROACHES THE AREA...LIKELY ON SAT
NIGHT INTO SUN. THE NEXT WAVE...ASSOCIATED WITH WAA ALOFT AND WARM
FRONT STRETCHING SE FROM LOW CENTERED IN THE CANADIAN PRAIRIES WILL
PUSH ACROSS THE AREA SUN NIGHT INTO MON. BEHIND THE FRONT...EXPECT
TEMPS TO TREND BACK TO OR SLIGHTLY ABOVE NORMAL BY TUES AS HIGH
PRESSURE MOVES OVERHEAD AND UPPER RIDGE BEGINS TO DEVELOP OVER THE
NRN/CNTRL PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 143 PM EDT TUE MAY 29 2012
LOW PRESSURE TROF SLIDING ACROSS THE UPPER GREAT LAKES AND COOL AIR
ALOFT WILL RESULT IN PLENTY OF CLOUDS WITH SCT SHRA AT TIMES INTO
TONIGHT...MAINLY AT KIWD/KSAW. CIGS AT KIWD/KCMX/KSAW WILL BE VFR
BUT MAY SEE VERY BRIEF VIS RESTRICTION TO MVFR IN SOME OF THE -SHRA
THIS AFTN. SFC TROF MOVING ACROSS THE AREA TONIGHT SHOULD USHER IN
LOW MVFR CIGS ALONG WITH INTERMITTENT -RA. NOT OF THE QUESTION THAT
IFR CIGS COULD DEVELOP ESPECIALLY AT KIWD/KSAW. IMPROVEMENT TO VFR
EXPECTED WED AFTN AS 850MB THERMAL TROF SLIPS TO THE E AND LOW-LEVEL
WINDS BECOME INCREASINGLY ANTICYCLONIC.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT TUE MAY 29 2012
WITH COLD FRONT DROPPING ACROSS LAKE SUPERIOR TONIGHT...WESTERLY
WINDS GUSTING TO 20-25KT WILL SHIFT NORTHERLY. WINDS WILL THEN BEGIN
TO DIMINISH FROM W TO E WED AND ESPECIALLY WED NIGHT AS HIGH PRES
BUILDS INTO THE UPPER LAKES. BY LATE WED NIGHT...WINDS WILL BE UNDER
15KT. WINDS WILL REMAIN MOSTLY UNDER 15KT THRU THU AND INTO FRI
AFTN. WINDS MAY INCREASE A LITTLE LATER FRI INTO SAT OVER EASTERN
LAKE SUPERIOR AS LOW PRES MOVES NE THRU THE CNTRL GREAT LAKES
REGION. OTHERWISE...WINDS WILL GENERALLY REMAIN ON THE LIGHT SIDE
INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT TUE MAY 29 2012
.SYNOPSIS...
ISSUED AT 507 AM EDT TUE MAY 29 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NW
MN RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE NRN GREAT
LAKES. INSTABILITY LINGERING ALONG SFC COLD FRONT OVER FAR ERN UPR
MI HAS MAINTAINED LINE OF SHOWERS WHICH ARE NOW MOVING EAST OVER
DUCK LAKE WILDFIRE AREA OF NRN LUCE COUNTY. WFO MQT RECEIVED .2 INCH
OF RAINFALL FROM THESE SHOWERS WHEN THEY PASSED ACROSS THE AREA AT 1
AM THIS MORNING. ANOTHER LOW PRESSURE SYSTEM AND SECONDARY COLD
FRONT OVER THE NRN MN/CANADIAN BORDER IS POISED TO MOVE THROUGH THE
UPPER GREAT LAKES TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
EXPECT ANY PATCHY FOG TO LIFT TOWARD DAYBREAK AS SW GRADIENT WIND
INCREASES SLIGHTLY AHEAD OF APPROACHING LOW PRES TROUGH AND
SECONDARY COLD FRONT FROM THE NRN PLAINS. SW WIND WILL ALSO BE
ADVECTING IN DRIER DEWPOINTS...IN THE 40S.
TODAY...GOING FCST LOOKS ON TRACK WITH THICKENING CLOUDS AND SCT
INSTABILITY SHRA DEVELOPING BY LATE MORNING/AFTN AS THE MID/UPPER
TROUGH AXIS MOVES IN FROM THE WEST. MODELS ALSO INDICATE ANOTHER
SHORTWAVE TROUGH ROTATING THROUGH ALSO BOOSTING SHRA CHANCES. WITH
VERY LIMITED INSTABILITY (SBCAPE VALUES 100-200 J/KG) EXPECTED...NO
TSRA IS EXPECTED.
TONIGHT AND WEDNESDAY...DIURNAL SHOWERS WILL DIMINISH BY EARLY
EVENING AS SHORTWAVE PASSES EAST AND WE LOSE INSTABILITY.
HOWEVER...AS WE LOSE DIURNAL INSTABILITY...INSTABILITY OVER LAKE
SUPERIOR WILL INCREASE AS SECONDARY SFC TROUGH/COLD FRONT MOVES
THROUGH WRN LAKE SUPERIOR DURING THE EVENING AND ERN LAKE SUPERIOR
EARLY OVERNIGHT HRS. MODELS ALSO HINT AT ANOTHER SHORTWAVE
APPROACHING OVERNIGHT WHICH COMBINED WITH 850 MB TEMPS AROUND
-2C...LINGERING SFC-700 MB MOISTURE...AND WEAKLY CYCLONIC NW FLOW
COULD PROVIDE JUST ENOUGH WEAK FORCING FOR ISOLD/SCT LAKE ENHANCED
RAIN SHOWERS ALONG LAKE SUPERIOR. WILL MAINTAIN LOW CHC 20-30 POPS
FOR MAINLY COUNTIES BORDERING LAKE SUPERIOR TONIGHT INTO EARLY
WED.
SFC RDG BUILDING IN FROM THE NRN PLAINS AND ASSOC SUBSIDENCE/DRYING
WILL HELP SCOUR OUT LAKE CLOUDS BY LATE MORNING OVER WRN COUNTIES
AND BY LATE AFTERNOON/EVENING FOR ERN COUNTIES. WENT ON THE LOW END
OF GUIDANCE FOR WED TEMPS...ESPECIALLY OVER THE EAST HALF OF FCST
AREA WHERE NW WINDS 10 TO 20 MPH COMBINED WITH EXTENSIVE LAKE CLOUDS
AND 850 MB TEMPS AROUND -2C WILL LIKELY KEEP TEMPS IN THE MID TO
UPPER 40S FOR HIGHS. MID 50S MAY BE REALIZED FAR INLAND ALONG THE WI
BDR AND FOR DOWNSLOPING AREAS ALONG THE BAY OF GREEN BAY WHERE THERE
WILL BE A BIT MORE SUNSHINE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
THERMAL TROUGH AT H85 COULD STILL LEAD TO LAKE CLOUDS EARLY ON
WEDNESDAY EVENING WITH LINGERING NW WINDS. OTHERWISE...HIGH PRESSURE
DRIFTING ACROSS AREA ON WEDNESDAY NIGHT WITH PWATS BLO 40 PCT OF
NORMAL ADDS UP TO CHILLY LATE MAY NIGHT. WIDESPREAD FROST WITH HARD
FREEZE IN ISOLATED SPOTS STILL ON TRACK...ESPECIALLY INLAND WEST.
COULD SEE THE NEED FOR A FREEZE WATCH AS MANY INLAND AREAS MAY BE
INTO THE UPR 20S. AT THE LEAST...APPEARS A FROST ADVISORY WILL BE
NEEDED WITHIN THE NEXT DAY. CERTAINLY NOT UNHEARD OF TO SEE TEMPS
THIS COLD TOWARD 1ST OF JUNE. RECORD LOWS FOR INLAND AREAS ON 31
MAY ARE AROUND 25 DEGREES IN MANY LOCATIONS.
HIGH PRESSURE REMAINS IN VCNTY INTO THURSDAY SO WINDS WILL BE LIGHT
AND LAKE BREEZES SHOULD DOMINATE. WARMING 925-850MB TEMPS AND LIGHT
WINDS SHOULD ALLOW TEMPS INLAND TO WARM OVER THE COOLER READINGS ON
THURSDAY. EXPECT HIGHS INLAND TO BE IN THE MIDDLE 60S BUT ONSHORE
FLOW NEAR THE LAKES KEEPS TEMPS THERE IN THE UPPER 50S. IN ADDITION
TO SCT-BKN CU CLOUDS WITH MARGINALLY COOL H85-H7 TEMPS...COULD SEE
INCREASING HIGH CLOUDS BY LATE DAY AHEAD OF DEVELOPING LOW PRESSURE
SYSTEM IN THE CNTRL MISSISSIPPI RIVER VALLEY AND WESTERN PORTIONS OF
OHIO VALLEY.
PER HPC THE PREFERNCE FOR LATE WEEK IS TO FOLLOW ECMWF IDEA WITH
HANDLING OF THIS SFC LOW. ECMWF HAS SHOWN NOTABLE NORTHWARD TREND TO
THE LOW...NOW BRINGING IT CLOSE ENOUGH ON FRIDAY TO RESULT IN RAIN
CHANCES OVER MUCH OF UPR MICHIGAN. LATEST ECMWF IS EVEN QUICKER WITH
THIS SYSTEM...SHOVING QPF INTO SOUTH AND EAST CWA BY LATE THURSDAY
NIGHT. GIVEN THE PREFERENCE FM HPC AND DECENT AGREEMENT FM THE
ECMWF/GFS...HAVE WENT WITH INCREASED CLOUD COVER AND CHANCE POPS
MOST AREAS ON FRIDAY. CHANCE POPS CONTINUE INTO FRIDAY NIGHT. GIVEN
VERY AMPLIFIED UPPER LEVEL PATTERN FCST BY ECMWF CONSENSUS SHOWED
LINGERING POPS INTO SATURDAY AS WELL. SHOULD NOTE THAT SOME MODELS
STILL HANDLE THE SYSTEM MUCH DIFFERENTLY WITH THE NAM/CANADIAN
KEEPING THE UPPER/SFC LOWS TOO FAR SOUTH TO IMPACT UPR MICHIGAN.
WILL ROOT FOR THE ECMWF TO WORK OUT THOUGH AS THOSE KIND OF SYSTEMS
TYPICALLY CAN RESULT IN DECENT RAIN AMOUNTS FOR UPR LAKES...BOOSTED
BY STRONGER DEFORMATION ON NORTHWEST FLANK OF UPPER/MID LEVEL LOWS.
AS IT STANDS RIGHT NOW LAST COUPLE RUNS OF ECMWF WOULD PLACE THE
THAT HEAVIER RAIN AREA RIGHT OVER EASTERN CWA WHERE THE DUCK LAKE
AND PINE CREEK WILDFIRES ARE LOCATED.
REST OF WEEKEND INTO NEXT MONDAY FEATURES TRANSITION TO WARMER TEMPS
AND PATTERN MORE TYPICAL OF LATE SPRING VERSUS LATE WINTER/EARLY
SPRING ONE THAT MAY SET UP LATER THIS WEEK WITH THE STRONG UPPER LOW.
WARM AIR ADVECTION MAY TRIGGER SOME SHRA/TSRA LATER SUNDAY AND MORE
SO INTO MONDAY. FOLLOWED CONSENSUS FOR NOW AS MOST GUIDANCE WAS IN
REASONABLE AGREEMENT WITH THE GENERAL UPPER AIR/SFC PATTERNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 143 PM EDT TUE MAY 29 2012
LOW PRESSURE TROF SLIDING ACROSS THE UPPER GREAT LAKES AND COOL AIR
ALOFT WILL RESULT IN PLENTY OF CLOUDS WITH SCT SHRA AT TIMES INTO
TONIGHT...MAINLY AT KIWD/KSAW. CIGS AT KIWD/KCMX/KSAW WILL BE VFR
BUT MAY SEE VERY BRIEF VIS RESTRICTION TO MVFR IN SOME OF THE -SHRA
THIS AFTN. SFC TROF MOVING ACROSS THE AREA TONIGHT SHOULD USHER IN
LOW MVFR CIGS ALONG WITH INTERMITTENT -RA. NOT OF THE QUESTION THAT
IFR CIGS COULD DEVELOP ESPECIALLY AT KIWD/KSAW. IMPROVEMENT TO VFR
EXPECTED WED AFTN AS 850MB THERMAL TROF SLIPS TO THE E AND LOW-LEVEL
WINDS BECOME INCREASINGLY ANTICYCLONIC.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EDT TUE MAY 29 2012
OVERALL AN ACTIVE PERIOD WITH STRONG/GUSTY WINDS AT TIMES IS
POSSIBLE OVER LAKE SUPERIOR THROUGH THE UPCOMING WEEKEND...WITH THE
EXCEPTION OF WEDNESDAY INTO THURSDAY. GUSTY WEST WINDS TO 25 KTS
TODAY INTO TONIGHT AS SURFACE TROUGH CROSSES LK SUPERIOR. STRONGEST
WINDS TODAY EXPECTED OVR WESTERN AND NORTH CNTRL LK SUPERIOR AROUND
ISLE ROYALE AND KEWEENAW PENINSULA. STRONGER WINDS TONIGHT FROM
NORTH CENTRAL TO EASTERN SECTIONS AS WINDS SHIFT TO MORE NORTHWEST
DIRECTION. WAVES THROUGH TONIGHT WILL BE CHOPPY IN THESE AREAS AND
WILL AVERAGE 4 TO 6 FEET. WINDS DIMINISH ON WEDNESDAY AS HIGH
PRESSURE MOVES INTO AREA. WIND FCST FOR LATE WEEK UNCERTAIN AS
MODELS ARE TRENDING FARTHER NORTH WITH LOW PRESSURE INTO UPPER
LAKES. FCST SHOWS NORTHEAST WINDS BY FRIDAY BUT WINDS MAY NEED
INCREASED. WINDS SHIFT TO NORTHWEST ON SATURDAY IN WAKE OF THE
FRIDAY SYSTEM. AGAIN...WINDS MAY END UP STRONGER THAN CURRENTLY
FCST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...VOSS
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
754 AM EDT TUE MAY 29 2012
.SYNOPSIS...
ISSUED AT 507 AM EDT TUE MAY 29 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NW
MN RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE NRN GREAT
LAKES. INSTABILITY LINGERING ALONG SFC COLD FRONT OVER FAR ERN UPR
MI HAS MAINTAINED LINE OF SHOWERS WHICH ARE NOW MOVING EAST OVER
DUCK LAKE WILDFIRE AREA OF NRN LUCE COUNTY. WFO MQT RECEIVED .2 INCH
OF RAINFALL FROM THESE SHOWERS WHEN THEY PASSED ACROSS THE AREA AT 1
AM THIS MORNING. ANOTHER LOW PRESSURE SYSTEM AND SECONDARY COLD
FRONT OVER THE NRN MN/CANADIAN BORDER IS POISED TO MOVE THROUGH THE
UPPER GREAT LAKES TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
EXPECT ANY PATCHY FOG TO LIFT TOWARD DAYBREAK AS SW GRADIENT WIND
INCREASES SLIGHTLY AHEAD OF APPROACHING LOW PRES TROUGH AND
SECONDARY COLD FRONT FROM THE NRN PLAINS. SW WIND WILL ALSO BE
ADVECTING IN DRIER DEWPOINTS...IN THE 40S.
TODAY...GOING FCST LOOKS ON TRACK WITH THICKENING CLOUDS AND SCT
INSTABILITY SHRA DEVELOPING BY LATE MORNING/AFTN AS THE MID/UPPER
TROUGH AXIS MOVES IN FROM THE WEST. MODELS ALSO INDICATE ANOTHER
SHORTWAVE TROUGH ROTATING THROUGH ALSO BOOSTING SHRA CHANCES. WITH
VERY LIMITED INSTABILITY (SBCAPE VALUES 100-200 J/KG) EXPECTED...NO
TSRA IS EXPECTED.
TONIGHT AND WEDNESDAY...DIURNAL SHOWERS WILL DIMINISH BY EARLY
EVENING AS SHORTWAVE PASSES EAST AND WE LOSE INSTABILITY.
HOWEVER...AS WE LOSE DIURNAL INSTABILITY...INSTABILITY OVER LAKE
SUPERIOR WILL INCREASE AS SECONDARY SFC TROUGH/COLD FRONT MOVES
THROUGH WRN LAKE SUPERIOR DURING THE EVENING AND ERN LAKE SUPERIOR
EARLY OVERNIGHT HRS. MODELS ALSO HINT AT ANOTHER SHORTWAVE
APPROACHING OVERNIGHT WHICH COMBINED WITH 850 MB TEMPS AROUND
-2C...LINGERING SFC-700 MB MOISTURE...AND WEAKLY CYCLONIC NW FLOW
COULD PROVIDE JUST ENOUGH WEAK FORCING FOR ISOLD/SCT LAKE ENHANCED
RAIN SHOWERS ALONG LAKE SUPERIOR. WILL MAINTAIN LOW CHC 20-30 POPS
FOR MAINLY COUNTIES BORDERING LAKE SUPERIOR TONIGHT INTO EARLY
WED.
SFC RDG BUILDING IN FROM THE NRN PLAINS AND ASSOC SUBSIDENCE/DRYING
WILL HELP SCOUR OUT LAKE CLOUDS BY LATE MORNING OVER WRN COUNTIES
AND BY LATE AFTERNOON/EVENING FOR ERN COUNTIES. WENT ON THE LOW END
OF GUIDANCE FOR WED TEMPS...ESPECIALLY OVER THE EAST HALF OF FCST
AREA WHERE NW WINDS 10 TO 20 MPH COMBINED WITH EXTENSIVE LAKE CLOUDS
AND 850 MB TEMPS AROUND -2C WILL LIKELY KEEP TEMPS IN THE MID TO
UPPER 40S FOR HIGHS. MID 50S MAY BE REALIZED FAR INLAND ALONG THE WI
BDR AND FOR DOWNSLOPING AREAS ALONG THE BAY OF GREEN BAY WHERE THERE
WILL BE A BIT MORE SUNSHINE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
THERMAL TROUGH AT H85 COULD STILL LEAD TO LAKE CLOUDS EARLY ON
WEDNESDAY EVENING WITH LINGERING NW WINDS. OTHERWISE...HIGH PRESSURE
DRIFTING ACROSS AREA ON WEDNESDAY NIGHT WITH PWATS BLO 40 PCT OF
NORMAL ADDS UP TO CHILLY LATE MAY NIGHT. WIDESPREAD FROST WITH HARD
FREEZE IN ISOLATED SPOTS STILL ON TRACK...ESPECIALLY INLAND WEST.
COULD SEE THE NEED FOR A FREEZE WATCH AS MANY INLAND AREAS MAY BE
INTO THE UPR 20S. AT THE LEAST...APPEARS A FROST ADVISORY WILL BE
NEEDED WITHIN THE NEXT DAY. CERTAINLY NOT UNHEARD OF TO SEE TEMPS
THIS COLD TOWARD 1ST OF JUNE. RECORD LOWS FOR INLAND AREAS ON 31
MAY ARE AROUND 25 DEGREES IN MANY LOCATIONS.
HIGH PRESSURE REMAINS IN VCNTY INTO THURSDAY SO WINDS WILL BE LIGHT
AND LAKE BREEZES SHOULD DOMINATE. WARMING 925-850MB TEMPS AND LIGHT
WINDS SHOULD ALLOW TEMPS INLAND TO WARM OVER THE COOLER READINGS ON
THURSDAY. EXPECT HIGHS INLAND TO BE IN THE MIDDLE 60S BUT ONSHORE
FLOW NEAR THE LAKES KEEPS TEMPS THERE IN THE UPPER 50S. IN ADDITION
TO SCT-BKN CU CLOUDS WITH MARGINALLY COOL H85-H7 TEMPS...COULD SEE
INCREASING HIGH CLOUDS BY LATE DAY AHEAD OF DEVELOPING LOW PRESSURE
SYSTEM IN THE CNTRL MISSISSIPPI RIVER VALLEY AND WESTERN PORTIONS OF
OHIO VALLEY.
PER HPC THE PREFERNCE FOR LATE WEEK IS TO FOLLOW ECMWF IDEA WITH
HANDLING OF THIS SFC LOW. ECMWF HAS SHOWN NOTABLE NORTHWARD TREND TO
THE LOW...NOW BRINGING IT CLOSE ENOUGH ON FRIDAY TO RESULT IN RAIN
CHANCES OVER MUCH OF UPR MICHIGAN. LATEST ECMWF IS EVEN QUICKER WITH
THIS SYSTEM...SHOVING QPF INTO SOUTH AND EAST CWA BY LATE THURSDAY
NIGHT. GIVEN THE PREFERENCE FM HPC AND DECENT AGREEMENT FM THE
ECMWF/GFS...HAVE WENT WITH INCREASED CLOUD COVER AND CHANCE POPS
MOST AREAS ON FRIDAY. CHANCE POPS CONTINUE INTO FRIDAY NIGHT. GIVEN
VERY AMPLIFIED UPPER LEVEL PATTERN FCST BY ECMWF CONSENSUS SHOWED
LINGERING POPS INTO SATURDAY AS WELL. SHOULD NOTE THAT SOME MODELS
STILL HANDLE THE SYSTEM MUCH DIFFERENTLY WITH THE NAM/CANADIAN
KEEPING THE UPPER/SFC LOWS TOO FAR SOUTH TO IMPACT UPR MICHIGAN.
WILL ROOT FOR THE ECMWF TO WORK OUT THOUGH AS THOSE KIND OF SYSTEMS
TYPICALLY CAN RESULT IN DECENT RAIN AMOUNTS FOR UPR LAKES...BOOSTED
BY STRONGER DEFORMATION ON NORTHWEST FLANK OF UPPER/MID LEVEL LOWS.
AS IT STANDS RIGHT NOW LAST COUPLE RUNS OF ECMWF WOULD PLACE THE
THAT HEAVIER RAIN AREA RIGHT OVER EASTERN CWA WHERE THE DUCK LAKE
AND PINE CREEK WILDFIRES ARE LOCATED.
REST OF WEEKEND INTO NEXT MONDAY FEATURES TRANSITION TO WARMER TEMPS
AND PATTERN MORE TYPICAL OF LATE SPRING VERSUS LATE WINTER/EARLY
SPRING ONE THAT MAY SET UP LATER THIS WEEK WITH THE STRONG UPPER LOW.
WARM AIR ADVECTION MAY TRIGGER SOME SHRA/TSRA LATER SUNDAY AND MORE
SO INTO MONDAY. FOLLOWED CONSENSUS FOR NOW AS MOST GUIDANCE WAS IN
REASONABLE AGREEMENT WITH THE GENERAL UPPER AIR/SFC PATTERNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 752 AM EDT TUE MAY 29 2012
LOW PRESSURE SLIDING ACROSS THE UPPER GREAT LAKES AND COOL AIR ALOFT
WILL RESULT IN PLENTY OF CLOUDS WITH SCT SHRA AT TIMES INTO THIS
EVENING AT ALL THE TAF SITES. WILL NOT BE AN ALL DAY RAIN AND DO NOT
EXPECT MUCH IN THE WAY OF VSBY RESTRICTION. CIGS SHOULD BE LOWER END
VFR TODAY THEN SETTLE INTO MVFR RANGE TONIGHT. WEST WINDS COULD BE
GUSTY TODAY...ESPECIALLY AT THE MORE EXPOSED KCMX LOCATION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EDT TUE MAY 29 2012
OVERALL AN ACTIVE PERIOD WITH STRONG/GUSTY WINDS AT TIMES IS
POSSIBLE OVER LAKE SUPERIOR THROUGH THE UPCOMING WEEKEND...WITH THE
EXCEPTION OF WEDNESDAY INTO THURSDAY. GUSTY WEST WINDS TO 25 KTS
TODAY INTO TONIGHT AS SURFACE TROUGH CROSSES LK SUPERIOR. STRONGEST
WINDS TODAY EXPECTED OVR WESTERN AND NORTH CNTRL LK SUPERIOR AROUND
ISLE ROYALE AND KEWEENAW PENINSULA. STRONGER WINDS TONIGHT FROM
NORTH CENTRAL TO EASTERN SECTIONS AS WINDS SHIFT TO MORE NORTHWEST
DIRECTION. WAVES THROUGH TONIGHT WILL BE CHOPPY IN THESE AREAS AND
WILL AVERAGE 4 TO 6 FEET. WINDS DIMINISH ON WEDNESDAY AS HIGH
PRESSURE MOVES INTO AREA. WIND FCST FOR LATE WEEK UNCERTAIN AS
MODELS ARE TRENDING FARTHER NORTH WITH LOW PRESSURE INTO UPPER
LAKES. FCST SHOWS NORTHEAST WINDS BY FRIDAY BUT WINDS MAY NEED
INCREASED. WINDS SHIFT TO NORTHWEST ON SATURDAY IN WAKE OF THE
FRIDAY SYSTEM. AGAIN...WINDS MAY END UP STRONGER THAN CURRENTLY
FCST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...VOSS
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
517 AM EDT TUE MAY 29 2012
.SYNOPSIS...
ISSUED AT 507 AM EDT TUE MAY 29 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NW
MN RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE NRN GREAT
LAKES. INSTABILITY LINGERING ALONG SFC COLD FRONT OVER FAR ERN UPR
MI HAS MAINTAINED LINE OF SHOWERS WHICH ARE NOW MOVING EAST OVER
DUCK LAKE WILDFIRE AREA OF NRN LUCE COUNTY. WFO MQT RECEIVED .2 INCH
OF RAINFALL FROM THESE SHOWERS WHEN THEY PASSED ACROSS THE AREA AT 1
AM THIS MORNING. ANOTHER LOW PRESSURE SYSTEM AND SECONDARY COLD
FRONT OVER THE NRN MN/CANADIAN BORDER IS POISED TO MOVE THROUGH THE
UPPER GREAT LAKES TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
EXPECT ANY PATCHY FOG TO LIFT TOWARD DAYBREAK AS SW GRADIENT WIND
INCREASES SLIGHTLY AHEAD OF APPROACHING LOW PRES TROUGH AND
SECONDARY COLD FRONT FROM THE NRN PLAINS. SW WIND WILL ALSO BE
ADVECTING IN DRIER DEWPOINTS...IN THE 40S.
TODAY...GOING FCST LOOKS ON TRACK WITH THICKENING CLOUDS AND SCT
INSTABILITY SHRA DEVELOPING BY LATE MORNING/AFTN AS THE MID/UPPER
TROUGH AXIS MOVES IN FROM THE WEST. MODELS ALSO INDICATE ANOTHER
SHORTWAVE TROUGH ROTATING THROUGH ALSO BOOSTING SHRA CHANCES. WITH
VERY LIMITED INSTABILITY (SBCAPE VALUES 100-200 J/KG) EXPECTED...NO
TSRA IS EXPECTED.
TONIGHT AND WEDNESDAY...DIURNAL SHOWERS WILL DIMINISH BY EARLY
EVENING AS SHORTWAVE PASSES EAST AND WE LOSE INSTABILITY.
HOWEVER...AS WE LOSE DIURNAL INSTABILITY...INSTABILITY OVER LAKE
SUPERIOR WILL INCREASE AS SECONDARY SFC TROUGH/COLD FRONT MOVES
THROUGH WRN LAKE SUPERIOR DURING THE EVENING AND ERN LAKE SUPERIOR
EARLY OVERNIGHT HRS. MODELS ALSO HINT AT ANOTHER SHORTWAVE
APPROACHING OVERNIGHT WHICH COMBINED WITH 850 MB TEMPS AROUND
-2C...LINGERING SFC-700 MB MOISTURE...AND WEAKLY CYCLONIC NW FLOW
COULD PROVIDE JUST ENOUGH WEAK FORCING FOR ISOLD/SCT LAKE ENHANCED
RAIN SHOWERS ALONG LAKE SUPERIOR. WILL MAINTAIN LOW CHC 20-30 POPS
FOR MAINLY COUNTIES BORDERING LAKE SUPERIOR TONIGHT INTO EARLY
WED.
SFC RDG BUILDING IN FROM THE NRN PLAINS AND ASSOC SUBSIDENCE/DRYING
WILL HELP SCOUR OUT LAKE CLOUDS BY LATE MORNING OVER WRN COUNTIES
AND BY LATE AFTERNOON/EVENING FOR ERN COUNTIES. WENT ON THE LOW END
OF GUIDANCE FOR WED TEMPS...ESPECIALLY OVER THE EAST HALF OF FCST
AREA WHERE NW WINDS 10 TO 20 MPH COMBINED WITH EXTENSIVE LAKE CLOUDS
AND 850 MB TEMPS AROUND -2C WILL LIKELY KEEP TEMPS IN THE MID TO
UPPER 40S FOR HIGHS. MID 50S MAY BE REALIZED FAR INLAND ALONG THE WI
BDR AND FOR DOWNSLOPING AREAS ALONG THE BAY OF GREEN BAY WHERE THERE
WILL BE A BIT MORE SUNSHINE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 507 AM EDT TUE MAY 29 2012
THERMAL TROUGH AT H85 COULD STILL LEAD TO LAKE CLOUDS EARLY ON
WEDNESDAY EVENING WITH LINGERING NW WINDS. OTHERWISE...HIGH PRESSURE
DRIFTING ACROSS AREA ON WEDNESDAY NIGHT WITH PWATS BLO 40 PCT OF
NORMAL ADDS UP TO CHILLY LATE MAY NIGHT. WIDESPREAD FROST WITH HARD
FREEZE IN ISOLATED SPOTS STILL ON TRACK...ESPECIALLY INLAND WEST.
COULD SEE THE NEED FOR A FREEZE WATCH AS MANY INLAND AREAS MAY BE
INTO THE UPR 20S. AT THE LEAST...APPEARS A FROST ADVISORY WILL BE
NEEDED WITHIN THE NEXT DAY. CERTAINLY NOT UNHEARD OF TO SEE TEMPS
THIS COLD TOWARD 1ST OF JUNE. RECORD LOWS FOR INLAND AREAS ON 31
MAY ARE AROUND 25 DEGREES IN MANY LOCATIONS.
HIGH PRESSURE REMAINS IN VCNTY INTO THURSDAY SO WINDS WILL BE LIGHT
AND LAKE BREEZES SHOULD DOMINATE. WARMING 925-850MB TEMPS AND LIGHT
WINDS SHOULD ALLOW TEMPS INLAND TO WARM OVER THE COOLER READINGS ON
THURSDAY. EXPECT HIGHS INLAND TO BE IN THE MIDDLE 60S BUT ONSHORE
FLOW NEAR THE LAKES KEEPS TEMPS THERE IN THE UPPER 50S. IN ADDITION
TO SCT-BKN CU CLOUDS WITH MARGINALLY COOL H85-H7 TEMPS...COULD SEE
INCREASING HIGH CLOUDS BY LATE DAY AHEAD OF DEVELOPING LOW PRESSURE
SYSTEM IN THE CNTRL MISSISSIPPI RIVER VALLEY AND WESTERN PORTIONS OF
OHIO VALLEY.
PER HPC THE PREFERNCE FOR LATE WEEK IS TO FOLLOW ECMWF IDEA WITH
HANDLING OF THIS SFC LOW. ECMWF HAS SHOWN NOTABLE NORTHWARD TREND TO
THE LOW...NOW BRINGING IT CLOSE ENOUGH ON FRIDAY TO RESULT IN RAIN
CHANCES OVER MUCH OF UPR MICHIGAN. LATEST ECMWF IS EVEN QUICKER WITH
THIS SYSTEM...SHOVING QPF INTO SOUTH AND EAST CWA BY LATE THURSDAY
NIGHT. GIVEN THE PREFERENCE FM HPC AND DECENT AGREEMENT FM THE
ECMWF/GFS...HAVE WENT WITH INCREASED CLOUD COVER AND CHANCE POPS
MOST AREAS ON FRIDAY. CHANCE POPS CONTINUE INTO FRIDAY NIGHT. GIVEN
VERY AMPLIFIED UPPER LEVEL PATTERN FCST BY ECMWF CONSENSUS SHOWED
LINGERING POPS INTO SATURDAY AS WELL. SHOULD NOTE THAT SOME MODELS
STILL HANDLE THE SYSTEM MUCH DIFFERENTLY WITH THE NAM/CANADIAN
KEEPING THE UPPER/SFC LOWS TOO FAR SOUTH TO IMPACT UPR MICHIGAN.
WILL ROOT FOR THE ECMWF TO WORK OUT THOUGH AS THOSE KIND OF SYSTEMS
TYPICALLY CAN RESULT IN DECENT RAIN AMOUNTS FOR UPR LAKES...BOOSTED
BY STRONGER DEFORMATION ON NORTHWEST FLANK OF UPPER/MID LEVEL LOWS.
AS IT STANDS RIGHT NOW LAST COUPLE RUNS OF ECMWF WOULD PLACE THE
THAT HEAVIER RAIN AREA RIGHT OVER EASTERN CWA WHERE THE DUCK LAKE
AND PINE CREEK WILDFIRES ARE LOCATED.
REST OF WEEKEND INTO NEXT MONDAY FEATURES TRANSITION TO WARMER TEMPS
AND PATTERN MORE TYPICAL OF LATE SPRING VERSUS LATE WINTER/EARLY
SPRING ONE THAT MAY SET UP LATER THIS WEEK WITH THE STRONG UPPER LOW.
WARM AIR ADVECTION MAY TRIGGER SOME SHRA/TSRA LATER SUNDAY AND MORE
SO INTO MONDAY. FOLLOWED CONSENSUS FOR NOW AS MOST GUIDANCE WAS IN
REASONABLE AGREEMENT WITH THE GENERAL UPPER AIR/SFC PATTERNS. &&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 133 AM EDT TUE MAY 29 2012
THERE IS A CONSIDERABLE AMOUNT OF MARINE FOG ON LAKE SUPERIOR DUE TO
REMAINING LOW LEVEL MOISTURE. ONSET OF UPSLOPE WRLY WINDS AT KCMX
WITH SECONDARY COLD FRONT COULD RESULT IN BRIEF LOWERING CIGS/VIS
OVER THE NEXT COUPLE OF HOURS. OTHERWISE...EXPECT VFR CONDITIONS AT
KIWD AND KSAW WITH INCREASINGLY DRIER WRLY FLOW THROUGH THE OVERNIGHT
HRS. ALSO EXPECT ANY LOW STRATUS/PATCHY FOG AT KCMX TO LIFT TOWARD
SUNRISE WITH DRIER FLOW. CONTINUED LOW PRESSURE OVER THE UPPER GREAT
LAKES WILL MEAN THE RETURN OF -SHRA CHANCES OVER MUCH OF INLAND UPPER
MI BY TOMORROW MORNING...SO WENT WITH VCSH AT KIWD AND KSAW...THOUGH
DO NOT EXPECT MUCH IN THE WAY OF VIS RESTRICTION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EDT TUE MAY 29 2012
OVERALL AN ACTIVE PERIOD WITH STRONG/GUSTY WINDS AT TIMES IS
POSSIBLE OVER LAKE SUPERIOR THROUGH THE UPCOMING WEEKEND...WITH THE
EXCEPTION OF WEDNESDAY INTO THURSDAY. GUSTY WEST WINDS TO 25 KTS
TODAY INTO TONIGHT AS SURFACE TROUGH CROSSES LK SUPERIOR. STRONGEST
WINDS TODAY EXPECTED OVR WESTERN AND NORTH CNTRL LK SUPERIOR AROUND
ISLE ROYALE AND KEWEENAW PENINSULA. STRONGER WINDS TONIGHT FROM
NORTH CENTRAL TO EASTERN SECTIONS AS WINDS SHIFT TO MORE NORTHWEST
DIRECTION. WAVES THROUGH TONIGHT WILL BE CHOPPY IN THESE AREAS AND
WILL AVERAGE 4 TO 6 FEET. WINDS DIMINISH ON WEDNESDAY AS HIGH
PRESSURE MOVES INTO AREA. WIND FCST FOR LATE WEEK UNCERTAIN AS
MODELS ARE TRENDING FARTHER NORTH WITH LOW PRESSURE INTO UPPER
LAKES. FCST SHOWS NORTHEAST WINDS BY FRIDAY BUT WINDS MAY NEED
INCREASED. WINDS SHIFT TO NORTHWEST ON SATURDAY IN WAKE OF THE
FRIDAY SYSTEM. AGAIN...WINDS MAY END UP STRONGER THAN CURRENTLY
FCST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...VOSS
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JMW/JV
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
142 AM EDT TUE MAY 29 2012
.SYNOPSIS...
ISSUED AT 450 PM EDT MON MAY 28 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NW
NORTH DAKOTA RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE NRN
GREAT LAKES. AT THE SFC...A BROAD AREA OF LOW PRES EXTENDED FROM SE
MANITOBA TO LAKE SUPERIOR WITH A COLD FRONT EXTENDING FROM CNTRL LAKE
SUPERIOR INTO CNTRL WI AND ERN IA. CLUSTERS OF STRONG TSRA HAVE
DEVELOPED AHEAD OF THE COLD FRONT OVER NE WI INTO S CNTRL UPPER MI
WHERE A SVR WATCH HAS BEEN ISSUED. LAKE BREEZE BOUNDARIES OFF OF LAKE
SUPERIOR HAVE PUSHED QUICKLY THROUGH NW AND N CNTRL UPPER MI.
ADDITIONAL TSRA HAD DEVELOPED ALONG AND OVER THE LK BREEZE AND MOVED
THROUGH N CNTRL UPPER MI INTO LAKE SUPERIOR. ANOTHER AREA OF TSRA HAD
DEVELOPED FROM DLH TO STC AHEAD OF A TRAILING SHRTWV TROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 450 PM EDT MON MAY 28 2012
LATE THIS AFTERNOON AND TONIGHT...WITH SBCAPE VALUES INTO THE
1000-1500 J/KG RANGE AHEAD OF NE MOVING SHRA/TSRA...EXPECT
CONTINUING SVR POTENTIAL FROM ESC TO ERY THROUGH 00Z. THE MAIN
HAZARD WILL CONTINUE TO BE DAMAGING WIND GUSTS. EXPECT THE SHRA/TSRA
OVER THE EAST HALF TO DIMINISH/END OVER THE CNTRL/EAST LATER THIS
EVENING AS THE INITIAL FRONT/TROUGH MOVES THROUGH THE AREA AND
SLIGHTLY DRIER AIR MOVES IN. HOWEVER...PER RADAR/SATELLITE TRENDS
EXPECT SCT SHRA/TSRA TO MOVE INTO THE WRN CWA LATER THIS EVENING AND
LIFT OVER LAKE SUPERIOR LATE TONIGHT.
TUESDAY...GOING FCST LOOKS ON TRACK WITH THICKENING CLOUDS AND
INCREASING SCT INSTABILITY SHRA BY AFTN AS THE MID/UPPER TROUGH AXIS
SETTLES CLOSE BY. HINT OF ANOTHER SHORTWAVE TROUGH ROTATING THROUGH
SHOULD ALSO BOOST SHRA CHANCES. WITH VERY LIMITED INSTABILITY
(SBCAPE VALUES AOB 200 J/KG) EXPECTED...NO TSRA WERE MENTIONED AT
THIS TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 450 PM EDT MON MAY 28 2012
TUES NIGHT THROUGH THURSDAY...SHOWERS SHOULD DEVELOP TUES AFTN
ASSOCIATED WITH STEEP LLVL LAPSE RATES AND SHORTWAVE ROTATING
THROUGH. EXPECT THESE SHOWERS TO DIMINISH TOWARDS THE START OF THE
PERIOD...ESPECIALLY OVER THE ERN CWA AS MUCH OF THE UPPER LEVEL
DYNAMICS SHIFT TO THE NE OF THE CWA. WITH THAT BEING SAID...EXPECT
SCATTERED SHOWERS TO LINGER OVER THE WRN THIRD OF THE CWA DURING THE
EVENING AS THE SFC TROUGH SLIDES S ACROSS THE AREA. THE WRN THIRD
WILL BE UNDER THE STRONGER FORCING FROM THE H925-850 TROUGH AND
DEEPER MOISTURE. THUS...HAVE BUMPED POPS UP TO CHANCES AND LINGERED
THROUGH MUCH OF THE NIGHT OVER THE FAVORED HIGHER TERRAIN LOCATIONS
FAVORED BY NW WINDS. HIGH RES MODEL RUNS PICK UP ON THIS FAIRLY WELL
AND HAVE FOLLOWED THE TRENDS...ALTHOUGH POPS MAY END UP NEEDING TO
BUMPED UP FURTHER. HAVE PUT SLIGHT POPS IN FARTHER EAST NEAR LK
SUPERIOR DURING THE OVERNIGHT HOURS DUE TO THE LIGHT UPSLOPE FLOW
AND FRICTIONAL CONVERGENCE. EXPECT THESE SHOWERS TO TO LINGER INTO
THE FIRST PART OF WED MORNING...BEFORE DRIER AIR ARRIVES.
UPPER TROUGH OVER ERN CANADA WILL PIVOT THROUGH ON WED...WHILE SFC
HIGH PRESSURE MOVES OVER THE AREA ON WED AND REMAINS THROUGH THURS.
THE DRIER AIR WITH THE HIGH PRESSURE WILL LEAD TO DECREASING CLOUDS
FROM WEST TO EAST FROM MID MORNING ON. SHOULD SEE SOME SCT CLOUDS
REDEVELOP WITH LINGERING MOISTURE AND DIURNAL HEATING AWAY FROM LK
SUPERIOR BUT THEN DIMINISH WITH THE INCREASING DRY AIR. FAIRLY COLD
CANADIAN AIR ALOFT WITH H850 TEMPS AROUND -2C OVER THE AREA AROUND
MID DAY THEN GRADUALLY WARM INTO THE LOWER SINGLE DIGITS IN THE
AFTN. THIS SHOULD LEAD TO WELL BELOW NORMAL HIGHS ACROSS THE
AREA ON WED. DID TWEAK TEMPS UP SLIGHTLY FROM THE GOING FORECAST
OVER THE INTERIOR W WHERE THE MOST SUN WILL LIKELY BE HAD.
MEANWHILE...COOL NNW FLOW OFF LK SUPERIOR WILL CAUSE TEMPS TO
STRUGGLE TO REACH 50 FROM MARQUETTE EASTWARD ALONG THE SHORELINE.
LOOKS LIKE A GOOD POTENTIAL OF FROST ON WED NIGHT UNDER MOSTLY CLEAR
SKIES. PWATS ARE AROUND 30 PERCENT OF NORMAL...LIGHT WINDS UNDER THE
HIGH...AND COOL DAYTIME TEMPS ON WED SHOULD LEAD TO A COLD NIGHT
ACROSS THE CWA. EXPECT TEMPS TO FALL INTO THE UPPER 20S AND LOWER
30S AWAY FROM THE GREAT LKS. DID BUMP UP FROST MENTION TO AREAS
OVER THE INTERIOR WEST AND PORTIONS OF THE EAST.
SHORTWAVE MOVING OUT OF THE ROCKIES ON WED NIGHT WILL AMPLIFY AN
UPPER WAVE OVER THE PLAINS STATES ON THURS AND LEAD TO A LOW
DEVELOPING OVER THE CNTRL/SRN PLAINS. NAM/GFS HINTING AT SOME
DIURNAL CU DEVELOPING OVER INLAND AREAS ON THURS...ESPECIALLY ALONG
THE LK BREEZE AREAS AND DID TRY TO SHOW SOME INCREASED CLOUD COVER
IN THOSE AREAS. OTHERWISE...HIGH PRESSURE WILL BE IN CONTROL AND
LEAD TO LK BREEZES DEVELOPING OFF BOTH LK SUPERIOR/MI.
FOR THE EXTENDED /THURSDAY NIGHT THROUGH NEXT MONDAY/...
EXTENDED FORECAST LOOKS TO BE MORE SIMILAR TO LATE WINTER AND EARLY
SPRING THAN THE FIRST PART OF JUNE. LOW DEVELOPING IN THE CNTRL/SRN
PLAINS ON THURS WILL MOVE NE THROUGH THE OHIO RIVER VALLEY ON FRIDAY
AND THE EASTERN GREAT LKS ON SAT. 00Z ECMWF NOT AS WRAPPED UP AND
FARTHER N THAN 00Z GEM/GFS. AFTER LOOKING AT THEIR ENS MEANS...A
GENERAL CONSENSUS SEEMS REASONABLE AND WILL FOLLOW THAT FOR THE
MOVEMENT OF THE LOW. THIS TRACK WILL BRUSH THE CWA AND COULD SEE
SOME SHOWERS OVER THE ERN PART OF THE CWA ON FRI NIGHT...BUT MAINLY
EXPECT MID-HIGH CLOUDS OVER MUCH OF THE CWA.
SFC RIDGE WILL MOVE OVER THE CWA ON SUN IN ASSOCIATION WITH HIGH
PRESSURE OVER THE CNTRL PLAINS AND BUILDING UPPER RIDGE OVER THE
CNTRL CONUS. THIS RIDGE WILL SHIFT E ON MON AS SFC LOW DROPS OUT OF
THE CANADIAN ROCKIES AND COLD FRONT MOVES THROUGH THE DAKOTAS. 12Z
GFS HAS PUSHED THIS THROUGH MUCH FASTER AND WILL FOLLOW MORE
CONSISTENT ECMWF. IT SHOWS H850-700 Q-VECTOR CONV AND MOISTURE
MOVING THROUGH MON...WHICH WARRANTS MENTIONING A CHANCE OF PCPN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 133 AM EDT TUE MAY 29 2012
THERE IS A CONSIDERABLE AMOUNT OF MARINE FOG ON LAKE SUPERIOR DUE TO
REMAINING LOW LEVEL MOISTURE. ONSET OF UPSLOPE WRLY WINDS AT KCMX
WITH SECONDARY COLD FRONT COULD RESULT IN BRIEF LOWERING CIGS/VIS
OVER THE NEXT COUPLE OF HOURS. OTHERWISE...EXPECT VFR CONDITIONS AT
KIWD AND KSAW WITH INCREASINGLY DRIER WRLY FLOW THROUGH THE OVERNIGHT
HRS. ALSO EXPECT ANY LOW STRATUS/PATCHY FOG AT KCMX TO LIFT TOWARD
SUNRISE WITH DRIER FLOW. CONTINUED LOW PRESSURE OVER THE UPPER GREAT
LAKES WILL MEAN THE RETURN OF -SHRA CHANCES OVER MUCH OF INLAND UPPER
MI BY TOMORROW MORNING...SO WENT WITH VCSH AT KIWD AND KSAW...THOUGH
DO NOT EXPECT MUCH IN THE WAY OF VIS RESTRICTION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EDT MON MAY 28 2012
EXPECT WINDS TO SHIFT SOUTHWEST TO WEST WINDS TO 25 KTS IN THE WAKE
OF A TROUGH/FRONTAL PASSAGE...ESPECIALLY OVR WRN AND NCNTRL LAKE
SUPERIOR AROUND ISLE ROYALE AND THE KEWEENAW PENINSULA. WINDS
VEERING NORTHWEST TUE NIGHT BEHIND A SECONDARY COLD FRONT COULD THEN
REMAIN GUSTY TO NEAR 30 KTS OVER EASTERN LK SUPERIOR TUE NIGHT INTO
WEDNESDAY MORNING. WINDS WILL DIMINISH LATER WEDNESDAY AS HIGH
PRESSURE BUILDS BACK OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JMW/JV
MARINE...JLB
AREA FORECAST DISCUSSION...CORRECTED
NWS GLASGOW MT
846 PM MDT WED MAY 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
00Z KGGW SOUNDING SHOWED AN UNSTABLE AIRMASS OVER THE
AREA...LIFTED INDEX -4. THIS ALONG WITH CHANNELED VORTICITY
CAUSING SCATTERED SHOWERS ALONG WITH AN ISOLATED THUNDERSTORM HERE
AND THERE ALSO. THESE HAVE FOCUSED ALONG THE NW-SE
ORIENTED...NEARLY STATIONARY...SURFACE BOUNDARY THAT SPLITS OUR
CWA ROUGHLY IN HALF. 50 DEGREE DEW POINTS POOLING ALONG IT.
ADJUSTED POPS FOR THE EVENING PART OF THE UPDATE. LOSS OF HEATING
AND WEAKENING UPPER DYNAMICS SHOULD CAUSE MOST OF THE SHOWERS TO
DIE OUT BY MIDNIGHT...ALTHOUGH THE SURFACE TROUGH WILL REMAIN OVER
OUR AREA. HRRR INDICATING SUCH WITH FORECAST 88D REFLECTIVITY.
SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT
THROUGH FRIDAY...SCATTERED CONVECTIVE SHOWERS WITH POSSIBLY A
LITTLE THUNDER ARE AROUND THE REGION THIS EVENING. EXPECT ACTIVITY
TO DECLINE AFTER DARK AS UPPER FORCING IS LIMITED. HRRR HAS
ACTIVITY ON DECLINE AFTER 3Z. SHOWER ACTIVITY IS AIDED BY A VERY
WEAK UPPER WAVE EMBEDDED IN NORTHWESTERLY FLOW ALOFT. THIS WAVE
BECOMES UNIDENTIFIABLE IN THE MODELS AFTER 3Z.
MORE WEAK DISTURBANCES IN THE UPPER FLOW ARE EXPECTED TO GIVE A
CHANCE FOR SHOWERS AGAIN THURSDAY AFTERNOON INTO FRIDAY...WITH RIDGING
BEGINNING TO DOMINATE...AND SHOWERS ON THE DECLINE...LATER ON
FRIDAY.
SHORT TERM PATTERN OF AN APPROACHING RIDGE IS NOT CONDUCIVE TO
SURFACE LOW FORMATION AND SURFACE WINDS SHOULD REMAIN LIGHT
THROUGH FRIDAY. INCREASING HIGH PRESSURE WILL LEAD TO AN INCREASE
IN TEMPERATURES THE NEXT COUPLE DAYS WITH LOWS NEAR 50 AND HIGHS
INTO THE 70S. MARTIN
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
FRIDAY NIGHT AND SATURDAY THE REGION WILL BE UNDER THE INFLUENCE
OF AN UPPER RIDGE. HOWEVER AROUND SATURDAY EVENING A PAC-NW UPPER
TROUGH SENDS MOISTURE AND A COLD FRONT ACROSS NORTHEAST MONTANA.
CONVECTIVE PARAMETERS APPEAR STRONG FOR THE CENTRAL REGIONS TO OUR
WEST. BUT WEAKER PARAMETERS COULD SUPPORT GENERAL THUNDERSTORMS
AND POSSIBLY SUSTAIN ANY STRONG STORMS FOR A WHILE THAT MOVE INTO
OUR AREA. TIMING ISSUES BETWEEN THE GFS AND THE EC WILL MAINLY
AFFECT WHEN THE FRONT MEETS THE PEAK AREAS OF INSTABILITY. SO WX
TYPE IS SOMEWHAT UNCERTAIN.
MODELS IN GENERAL DO NOT AGREE WITH THE TIMING OF THE NEXT TROUGH
MOVING IN FROM THE WEST EARLY NEXT WEEK. BUT THERE IS LIMITED
AGREEMENT WITH A COLD FRONT AND OVERRUNNING MOISTURE SUNDAY NIGHT
AND MONDAY THAT WILL AFFECT MONTANA AND POSSIBLY NORTHEAST MONTANA
WITH SHOWERS.
BY TUESDAY THE EC AND GFS ARE TOTALLY OUT OF PHASE WITH THE TROUGH
MOVEMENT OVER THE WEST. THE PATTERN LOOKS WET IN GENERAL SO WILL
LEAVE POPS MOSTLY ALONE FOR NOW. THE WAVES ARE SO FAR OUT OF PHASE
AS TO PREVENT BLENDING. HPC THINKS THE EC HAS THE STRONGEST
SOLUTION BUT IS TOO WARM...AND THE GFS IS THE FASTEST. TAKING
SOMETHING OF A BLEND IT LOOKS LIKE NEXT WEEK WILL BE COOL AND WET.
THE LAST BIG STORM WAS NAILED BY THE EC AND IT IS TEMPTING TO
LEAN ON IT AGAIN. A NOTE LATE IN THE SHIFT FROM THE CPC SAYS
CONFIDENCE IN THE EC FOR THAT PERIOD IS ABOVE AVERAGE. BUT
WAITING FOR MORE AGREEMENT IS THE WAY TO GO FOR NOW.
BASED ON THE LATEST GUIDANCE A FEW GRID EDITS FOR POPS WERE MADE
TO DAY 3 NIGHT AND DAY 4...BUT LIMITED CHANGES ELSEWHERE. SCT
PREVIOUS DISCUSSION...
THE EXTENDED FORECAST PERIOD BEGINS WITH A MODERATELY-WELL
ESTABLISHED UPPER LEVEL RIDGE OVER THE SPINE OF THE THE ROCKY
MOUNTAINS AND THE ADJACENT NORTHERN HIGH PLAINS REGION.
UNFORTUNATELY...ONLY 24 HOURS LATER...THE GFS AND THE EC MODELS
BEGIN TO FALL OUT OF PHASE WITH ONE ANOTHER AND NEVER COME CLOSE
TO ANY KIND OF A CONSENSUS THEREAFTER. CONSEQUENTLY...CONFIDENCE IN
THE ACCURACY OF THE EXTENDED FORECAST IS SHAKY FOR SUNDAY AND GETS
ONLY WORSE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST
PERIOD.
THE VERY GENERAL WEATHER PATTERN TRENDS I THINK WILL GO AS
FOLLOWS...
SUNDAY THROUGH MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES IN
RESPONSE TO AN APPROACHING AND DEEPENING WEST COAST UPPER LEVEL
TROUGH. EXACTLY HOW THIS TROUGH EVOLVES IS HANDLED COMPLETELY
DIFFERENTLY DEPENDING ON WHICH MODEL YOU TRUST. THE EC DIG THE
TROUGH INTO A CLOSED UPPER LOW AS FAR SOUTH AS DEATH VALLEY
CALIFORNIA BE EARLY WEDNESDAY WHILE THE GFS MESSES AROUND WITH A
SIMPLE OPEN WAVE OVER THE CENTRAL AND NORTHERN ROCKIES WHICH
DISAPPEARS VERY QUICKLY. BEYOND THEN...ANY SEMBLANCE OF MODEL
CONSENSUS IS GONE. OVERALL THE GFS IS THE VERY WET MODEL AND THE
EC IS THE VERY DRY MODEL. LOWEST FORECAST CONFIDENCE I HAVE HAD IN
QUITE SOME TIME FOR THE EXTENDED PERIOD. BMICKELSON
&&
.AVIATION...
UNSTABLE AIR...BEHIND A COLD FRONT THAT PUSHED THROUGH NORTHEAST
MONTANA THIS MORNING...HAS SPAWNED CONVECTION WITH ISOLATED RAIN
SHOWERS AND LIGHTNING STRIKES. ISOLATED THUNDERSTORMS WILL
DIMINISH DURING THE EVENING BUT WITH A SURFACE TROUGH AND
OVERRUNNING MOISTURE OVER THE STATIONARY COLD BOUNDARY ISOLATED
RAIN SHOWERS WILL CONTINUE INTO THURSDAY...GENERALLY SHIFTING
EAST. THE SHIFTING OF THE SURFACE TROUGH WILL SHIFT SE WINDS OF
AROUND 10KT TO THE WEST THROUGH THURSDAY. SCT
&&
.HYDROLOGY...
THE RECENT HEAVY RAINFALL CONTINUES TO MAKE ITS WAY INTO MAIN STEM
RIVERS. BEAVER CREEK NEAR HINSDALE AND THE FRENCHMAN CREEK NEAR
THE INTERNATIONAL BORDER HAVE ALSO RECORDED STREAM CRESTS. THE
POPLAR RIVER NEAR THE INTERNATIONAL BORDER HAS RISEN TO ACTION
STAGE...BUT APPEARS TO HAVE CRESTED.
THE LATEST MILK RIVER FORECASTS KEEP ALL POINTS BELOW ACTION
STAGE. THE MILK RIVER AT GLASGOW IS EXPECTED TO CREST AT 18.0 FT
LATE THIS AFTERNOON AND NASHUA SHOULD CREST AT 11.3 FT LATE
THURSDAY AFTERNOON. TAMPICO CRESTED AT 15.7 FT AROUND NOON AND IS
NOW FALLING. AREA CREEKS AND SMALLER TRIBUTARIES WILL CONTINUE TO
RUN HIGH FOR A COUPLE OF DAYS AS THE GENERAL 1.3 TO 2.7 INCHES OF
RECENT RAINFALL DRAINS THROUGH THE BASINS. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
844 PM MDT WED MAY 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
00Z KGGW SOUNDING SHOWED AN UNSTABLE AIRMASS OVER THE
AREA...LIFTED INDEX -4. THIS ALONG WITH CHANNELED VORTICITY
CAUSING SCATTERED SHOWERS ALONG WITH AN ISOLATED THUNDERSTORM HERE
AND THERE ALSO. THESE HAVE FOCUSED ALONG THE NW-SE
ORIENTED...NEARLY STATIONARY...SURFACE BOUNDARY THAT SPLITS OUR
CWA ROUGHLY IN HALF. 50 DEGREE DEW POINTS POOLING ALONG IT.
ADJUSTED POPS FOR THE EVENING PART OOF THE UPDATE. LOSS OF HEATING
AND WEAKENING UPPER DYNAMICS SHOULD CAUSE MOST OF THE SHOWERS TO
DIE OUT BY MIDNIGHT...ALTHOUGH THE SURFACE TROUGH WILL REMAIN OVER
OUR AREA. HRRR INDICATING SUCH WITH FORECAST 88D REFLECTIVITY.
SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT
THROUGH FRIDAY...SCATTERED CONVECTIVE SHOWERS WITH POSSIBLY A
LITTLE THUNDER ARE AROUND THE REGION THIS EVENING. EXPECT ACTIVITY
TO DECLINE AFTER DARK AS UPPER FORCING IS LIMITED. HRRR HAS
ACTIVITY ON DECLINE AFTER 3Z. SHOWER ACTIVITY IS AIDED BY A VERY
WEAK UPPER WAVE EMBEDDED IN NORTHWESTERLY FLOW ALOFT. THIS WAVE
BECOMES UNIDENTIFIABLE IN THE MODELS AFTER 3Z.
MORE WEAK DISTURBANCES IN THE UPPER FLOW ARE EXPECTED TO GIVE A
CHANCE FOR SHOWERS AGAIN THURSDAY AFTERNOON INTO FRIDAY...WITH RIDGING
BEGINNING TO DOMINATE...AND SHOWERS ON THE DECLINE...LATER ON
FRIDAY.
SHORT TERM PATTERN OF AN APPROACHING RIDGE IS NOT CONDUCIVE TO
SURFACE LOW FORMATION AND SURFACE WINDS SHOULD REMAIN LIGHT
THROUGH FRIDAY. INCREASING HIGH PRESSURE WILL LEAD TO AN INCREASE
IN TEMPERATURES THE NEXT COUPLE DAYS WITH LOWS NEAR 50 AND HIGHS
INTO THE 70S. MARTIN
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
FRIDAY NIGHT AND SATURDAY THE REGION WILL BE UNDER THE INFLUENCE
OF AN UPPER RIDGE. HOWEVER AROUND SATURDAY EVENING A PAC-NW UPPER
TROUGH SENDS MOISTURE AND A COLD FRONT ACROSS NORTHEAST MONTANA.
CONVECTIVE PARAMETERS APPEAR STRONG FOR THE CENTRAL REGIONS TO OUR
WEST. BUT WEAKER PARAMETERS COULD SUPPORT GENERAL THUNDERSTORMS
AND POSSIBLY SUSTAIN ANY STRONG STORMS FOR A WHILE THAT MOVE INTO
OUR AREA. TIMING ISSUES BETWEEN THE GFS AND THE EC WILL MAINLY
AFFECT WHEN THE FRONT MEETS THE PEAK AREAS OF INSTABILITY. SO WX
TYPE IS SOMEWHAT UNCERTAIN.
MODELS IN GENERAL DO NOT AGREE WITH THE TIMING OF THE NEXT TROUGH
MOVING IN FROM THE WEST EARLY NEXT WEEK. BUT THERE IS LIMITED
AGREEMENT WITH A COLD FRONT AND OVERRUNNING MOISTURE SUNDAY NIGHT
AND MONDAY THAT WILL AFFECT MONTANA AND POSSIBLY NORTHEAST MONTANA
WITH SHOWERS.
BY TUESDAY THE EC AND GFS ARE TOTALLY OUT OF PHASE WITH THE TROUGH
MOVEMENT OVER THE WEST. THE PATTERN LOOKS WET IN GENERAL SO WILL
LEAVE POPS MOSTLY ALONE FOR NOW. THE WAVES ARE SO FAR OUT OF PHASE
AS TO PREVENT BLENDING. HPC THINKS THE EC HAS THE STRONGEST
SOLUTION BUT IS TOO WARM...AND THE GFS IS THE FASTEST. TAKING
SOMETHING OF A BLEND IT LOOKS LIKE NEXT WEEK WILL BE COOL AND WET.
THE LAST BIG STORM WAS NAILED BY THE EC AND IT IS TEMPTING TO
LEAN ON IT AGAIN. A NOTE LATE IN THE SHIFT FROM THE CPC SAYS
CONFIDENCE IN THE EC FOR THAT PERIOD IS ABOVE AVERAGE. BUT
WAITING FOR MORE AGREEMENT IS THE WAY TO GO FOR NOW.
BASED ON THE LATEST GUIDANCE A FEW GRID EDITS FOR POPS WERE MADE
TO DAY 3 NIGHT AND DAY 4...BUT LIMITED CHANGES ELSEWHERE. SCT
PREVIOUS DISCUSSION...
THE EXTENDED FORECAST PERIOD BEGINS WITH A MODERATELY-WELL
ESTABLISHED UPPER LEVEL RIDGE OVER THE SPINE OF THE THE ROCKY
MOUNTAINS AND THE ADJACENT NORTHERN HIGH PLAINS REGION.
UNFORTUNATELY...ONLY 24 HOURS LATER...THE GFS AND THE EC MODELS
BEGIN TO FALL OUT OF PHASE WITH ONE ANOTHER AND NEVER COME CLOSE
TO ANY KIND OF A CONSENSUS THEREAFTER. CONSEQUENTLY...CONFIDENCE IN
THE ACCURACY OF THE EXTENDED FORECAST IS SHAKY FOR SUNDAY AND GETS
ONLY WORSE THROUGHOUT THE REMAINDER OF THE EXTENDED FORECAST
PERIOD.
THE VERY GENERAL WEATHER PATTERN TRENDS I THINK WILL GO AS
FOLLOWS...
SUNDAY THROUGH MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES IN
RESPONSE TO AN APPROACHING AND DEEPENING WEST COAST UPPER LEVEL
TROUGH. EXACTLY HOW THIS TROUGH EVOLVES IS HANDLED COMPLETELY
DIFFERENTLY DEPENDING ON WHICH MODEL YOU TRUST. THE EC DIG THE
TROUGH INTO A CLOSED UPPER LOW AS FAR SOUTH AS DEATH VALLEY
CALIFORNIA BE EARLY WEDNESDAY WHILE THE GFS MESSES AROUND WITH A
SIMPLE OPEN WAVE OVER THE CENTRAL AND NORTHERN ROCKIES WHICH
DISAPPEARS VERY QUICKLY. BEYOND THEN...ANY SEMBLANCE OF MODEL
CONSENSUS IS GONE. OVERALL THE GFS IS THE VERY WET MODEL AND THE
EC IS THE VERY DRY MODEL. LOWEST FORECAST CONFIDENCE I HAVE HAD IN
QUITE SOME TIME FOR THE EXTENDED PERIOD. BMICKELSON
&&
.AVIATION...
UNSTABLE AIR...BEHIND A COLD FRONT THAT PUSHED THROUGH NORTHEAST
MONTANA THIS MORNING...HAS SPAWNED CONVECTION WITH ISOLATED RAIN
SHOWERS AND LIGHTNING STRIKES. ISOLATED THUNDERSTORMS WILL
DIMINISH DURING THE EVENING BUT WITH A SURFACE TROUGH AND
OVERRUNNING MOISTURE OVER THE STATIONARY COLD BOUNDARY ISOLATED
RAIN SHOWERS WILL CONTINUE INTO THURSDAY...GENERALLY SHIFTING
EAST. THE SHIFTING OF THE SURFACE TROUGH WILL SHIFT SE WINDS OF
AROUND 10KT TO THE WEST THROUGH THURSDAY. SCT
&&
.HYDROLOGY...
THE RECENT HEAVY RAINFALL CONTINUES TO MAKE ITS WAY INTO MAIN STEM
RIVERS. BEAVER CREEK NEAR HINSDALE AND THE FRENCHMAN CREEK NEAR
THE INTERNATIONAL BORDER HAVE ALSO RECORDED STREAM CRESTS. THE
POPLAR RIVER NEAR THE INTERNATIONAL BORDER HAS RISEN TO ACTION
STAGE...BUT APPEARS TO HAVE CRESTED.
THE LATEST MILK RIVER FORECASTS KEEP ALL POINTS BELOW ACTION
STAGE. THE MILK RIVER AT GLASGOW IS EXPECTED TO CREST AT 18.0 FT
LATE THIS AFTERNOON AND NASHUA SHOULD CREST AT 11.3 FT LATE
THURSDAY AFTERNOON. TAMPICO CRESTED AT 15.7 FT AROUND NOON AND IS
NOW FALLING. AREA CREEKS AND SMALLER TRIBUTARIES WILL CONTINUE TO
RUN HIGH FOR A COUPLE OF DAYS AS THE GENERAL 1.3 TO 2.7 INCHES OF
RECENT RAINFALL DRAINS THROUGH THE BASINS. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
629 PM MDT WED MAY 30 2012
.SHORT TERM...VALID FOR THU AND FRI...
UPDATED FORECAST FOR THIS EVENING TO INCREASE POPS AND ADD
THUNDERSTORM MENTION TO EASTERN ZONES. CONTINUE TO SEE CONVECTIVE
DEVELOPMENT OVER NORTHEAST MONTANA SLIDE SOUTHEAST ACROSS
CUSTER/FALLON/CARTER COUNTIES. LATEST RUC KEEPS THIS AREA OF LOW
LEVEL CONVERGENCE/UPPER DIVERGENCE IN PLACE UNTIL AROUND
MIDNIGHT...THOUGH COOLING WITH SUNSET WILL TAKE THE EDGE OFF OF
CONVECTIVE INSTABILITY BEFORE THEN. INCREASED POPS TO HIGH CHANCE
CATEGORY FOR THESE AREAS INCLUDING MILES CITY...BAKER AND
EKALAKA. ELSEWHERE SEEING INFLUENCE OF SOME UPSTREAM ENERGY
VEERING SURFACE FLOW MORE NORTHERLY GENERATING SOME BETTER
UPSLOPE INTO WESTERN MOUNTAINS AND FOOTHILLS. THINK 20 PERCENT
POPS SHOULD COVER THIS WITH MAINLY SPRINKLES OR VERY LIGHT
PRECIPITATION DUE TO DRY LOWER LEVELS. CHAMBERS
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH ABOUT MONDAY...BUT
THEN DIVERGE SIGNIFICANTLY THEREAFTER. SOUTHWEST FLOW ALOFT WILL
PREVAIL SATURDAY THROUGH MONDAY WITH OCCASIONAL SHORT WAVES
TRACKING ACROSS THE FORECAST AREA...THOUGH GENERALLY ACROSS THE
WESTERN ZONES TO THE NORTHWESTERN ZONES DRAGGING A SURFACE TROUGH
OR FRONT BEHIND THEM. OVERALL I EXPECT TO SEE VERTICAL WIND
PROFILES WITH ENOUGH SHEAR AT TIMES TO SUSTAIN UPDRAFTS. IF OUR
DEWPOINTS GET HIGH ENOUGH WE MAY SEE SOME ISOLATED HAIL AND WIND
THREATS...TYPICAL OF THIS TIME OF YEAR.
BY TUESDAY...THE GFS AND EC DEVELOP DIFFERENT SOLUTIONS FOR
HANDLING THE TROUGHINESS OFF THE PACIFIC NORTHWEST COAST. THE GFS
SOLUTION IS MORE TYPICAL FOR THIS TIME OF YEAR WITH A PROGRESSIVE
WAVE LIFTING E/NE ACROSS MONTANA. THE ECMWF DIGS THE TROUGH SOUTH
CUTTING IT OFF BY WEDNESDAY OVER SALT LAKE CITY. I WOULD NORMALLY
TREND TO THE GFS...BUT THE EC SOLUTION IS SIMILAR TO OUR RECENT
RAIN EVENT LAST WEEKEND...AND THESE PATTERNS CAN SOMETIMES GET
INTO A GROOVE. I HAVE NO CONFIDENCE IN EITHER SOLUTION AT THIS
TIME...SO WILL USE A BROAD BRUSHED BLEND APPROACH PAST MONDAY.
THE MAIN CHANGE TO THIS EXTENDED PACKAGE WAS TO WARM UP SATURDAY
AS A STRONG THERMAL RIDGE IS PROGGED TO SHIFT OVER US WITH 850MB
TEMPS IN THE MID 20S CELSIUS...WHICH SHOULD PUT US IN THE LOWER
TO MID 80S WITH ANY DECENT MIXING. BT
&&
.AVIATION...
SCATTERED SHOWERS CONTINUE ACROSS MUCH OF THE REGION. HEAVIER
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS EASTERN
ROUTES...ESPECIALLY EAST OF KMLS AND BROADUS. PRECIPITATION WILL
SLOWLY TAPER OFF FROM WEST TO EAST OVERNIGHT. MVFR CONDITIONS ARE
EXPECTED IN THE STRONGER SHOWERS. PERIODIC MOUNTAIN OBSCURATIONS
CONTINUE...BUT ARE EXPECTED TO DIMINISH OVERNIGHT. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 047/073 052/077 054/084 054/076 051/074 051/073 052/075
20/B 32/T 23/T 33/T 33/T 22/T 22/T
LVM 040/069 044/075 046/083 047/072 044/070 044/071 042/070
12/T 22/T 24/T 33/T 33/T 33/T 33/T
HDN 044/075 049/077 050/085 052/080 050/077 051/076 052/079
20/B 31/B 23/T 33/T 32/T 33/T 22/T
MLS 044/073 052/077 054/086 057/078 054/078 054/081 056/078
40/B 31/B 12/T 32/W 22/T 43/T 23/T
4BQ 041/072 049/075 052/084 054/080 052/079 053/083 053/078
30/B 31/B 12/T 32/W 22/T 33/T 23/T
BHK 040/070 046/073 053/082 052/078 053/077 054/080 055/074
41/B 32/T 12/T 32/W 22/T 43/T 33/T
SHR 041/071 045/073 047/082 049/078 049/075 050/078 048/077
21/B 21/B 12/T 22/T 22/T 32/T 23/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
938 PM CDT WED MAY 30 2012
.UPDATE...AFTER A MORE-ACTIVE-THAN-EXPECTED DAY THAT FEATURED
ROUGHLY 6 HOURS OF SEVERE THUNDERSTORMS MAINLY ACROSS THE SOUTHERN
1/2 OF THE CWA...THINGS HAVE QUIETED DOWN CONSIDERABLY OVER THE
PAST FEW HOURS...WITH WHAT SHOULD BE THE LAST FEW WEAK STORMS OF
THE EVENING GRADUALLY EXITING A HANDFUL OF FAR SOUTHERN/SOUTHEASTERN
COUNTIES WITHIN THE NEXT 1-2 HOURS. 02Z OBJECTIVE SURFACE ANALYSIS
DEPICTS THE PRIMARY SYNOPTIC COLD FRONT PUSHING SOUTH OUT OF FAR
SOUTHERN NEB ZONES INTO KS...WITH STEADY BUT NOT OVERLY STRONG NORTH
BREEZES PUSHING IN BEHIND THE FRONT...DRIVEN BY A 1020MB HIGH
CENTERED OVER SOUTHERN ND/NORTHERN SD. ALTHOUGH OBJECTIVE
MESOSCALE ANALYSIS INDICATED THAT PARTS OF NORTH CENTRAL KS ZONES
MAY STILL BE HOLDING ON TO MUCAPE IN EXCESS OF 500 J/KG...THUNDER
POTENTIAL IS DEFINITELY ON A FAST DECLINE AS THE LOW LEVEL COLD
FRONT CONTINUES TO PUSH SOUTHWARD. ALOFT...WATER VAPOR IMAGERY
SHOWS THE PRIMARY WEST-NORTHWEST FLOW 500MB VORT MAX CENTERED NEAR
THE IA/NE/SD/MN BORDER AREA...WITH THE BEST LARGE SCALE FORCING
STEADILY DEPARTING EAST AS THE NIGHT PROGRESSES. ALTHOUGH SOME
LIGHT SHOWER POTENTIAL CANNOT BE RULED OUT AFTER MIDNIGHT EVEN
AFTER THUNDER EXITS...DECIDED THAT SUPPORT FOR MEASURABLE PRECIP
WAS LOW ENOUGH POST-06Z TO SIMPLY GO WITH A SLIGHT CHANCE OF
SPRINKLES...AND EVEN THIS MAY BE OVERKILL PER THE LATEST HRRR RUNS.
MAY TWEAK OVERNIGHT LOWS DOWNWARD VERY SLIGHTLY ON ONE MORE
FORECAST UPDATE WITHIN THE NEXT HOUR...WITH MUCH OF THE NORTHERN
CWA LIKELY HEADED FOR THE MID 40S...WITH UPPER 40S/NEAR 50
PREVAILING SOUTH. CLOUD TRENDS OVERNIGHT ARE SOMEWHAT
UNCERTAIN...AND EXPECT SOME VARIABILITY AS MID/HIGH CLOUDS RETREAT
SOMEWHAT FROM THE SOUTH AND LOWER STRATUS WORKS IN FROM THE NORTH.
&&
.PREV DISCUSSION... /ISSUED 552 PM CDT WED MAY 30 2012/
AVIATION...00Z TAF. THERE ARE SOME SHOWERS AND ISOLATED
THUNDERSTORMS TO THE WEST OF THE KGRI TERMINAL AREA. THEY SHOULD
MOVE THROUGH THE TERMINAL AREA IN THE FIRST HOUR OR TWO. EXPECT
THERE COULD BE SOME LOWER CLOUDS DURING THE NIGHT AND BE MVFR
CONDITIONS. THE CLOUDS SHOULD LIFT DURING THE MORNING AND START
TO CLEAR OUT IN THE AFTERNOON.
PREV DISCUSSION... /ISSUED 306 PM CDT WED MAY 30 2012/
SHORT TERM...THROUGH 00Z FRIDAY. MORNING UPPER AIR ANALYSIS
INDICATES QUASI-ZONAL TO NORTHWESTERLY MID AND UPPER LEVEL FLOW
ACROSS CENTRAL PORTIONS OF THE CONUS...WITH SUBTLE RIDGING ACROSS
THE WESTERN AND EASTERN CONUS. MID AND UPPER LEVEL JET ENERGY IS
POSITIONED FROM THE NORTHWESTERN CONUS...ACROSS CENTRAL PORTIONS
OF THE CONUS AND ON INTO THE EASTERN CONUS. EARLY AFTERNOON WATER
VAPOR IMAGERY SHOWS INCREASED VALUES OF MID LEVEL MOISTURE FLOWING
IN FROM THE PACIFIC...PUSHING ACROSS THE NORTHWESTERN CONUS AND
INTO THE CENTRAL PLAINS. A MID LEVEL SHORT WAVE IS ALSO NOTED OVER
THE NORTHERN PLAINS...MOVING EAST/SOUTHEAST. AT THE SURFACE A
TROUGH OF LOW PRESSURE IS NOTED EXTENDING ACROSS WESTERN NEBRASKA.
IN ADDITION...AN AREA OF HIGH PRESSURE IS LOCATED OVER THE UPPER
MISSISSIPPI VALLEY...WITH LOW LEVEL RETURN FLOW ON THE BACK SIDE
OF THE SURFACE RIDGE INFILTRATING PORTIONS OF THE CENTRAL PLAINS.
THAT BEING SAID...CONVECTIVELY INDUCED OUTFLOW AT THE SURFACE
IS PROMOTING A BIT MORE CHAOTIC LOW LEVEL WIND FIELD ACROSS OUR
CWA...THAN THAT OF THE TRUE SOUTHEASTERLY WINDS WHICH ARE TRYING
TO DEVELOP. THIS MESO-HIGH IS PROMOTING A DIFFERENTIAL HEATING
BOUNDARY NOW EVIDENT ACROSS WESTERN PORTIONS OF OUR CWA. KUEX
INDICATES CONVECTION PERSISTING ACROSS MUCH OF SOUTH CENTRAL
NEBRASKA AS OF MID AFTERNOON.
LOW LEVEL RETURN FLOW IS HELPING PROMOTE LOW LEVEL THERMAL
ADVECTION AND RESULTANT ISENTROPIC UPGLIDE AND SATURATION OVER OUR
CWA...PRIMARILY ALONG THE 300-310K SURFACES. LAPS PROXIMITY
SOUNDINGS FROM ACROSS OUR WESTERN CWA SUGGEST AIR
PARCELS...ASCENDING FROM AROUND 700MB...ARE CONTENDING WITH LESS
THAN 30J/KG CIN AND WORKING WITH 600-1000J/KG CAPE. IN ADDITION...MID
AND UPPER LEVEL JET ENERGY IS HELPING PROMOTE DEEP LAYER BULK
SHEAR VALUES OF 30-40KTS. EVEN THOUGH THE INSTABILITY IS NOT
OVERLY IMPRESSIVE...THE COOL LOW TO MID LEVEL AIRMASS AND THE DEEP
LAYER SHEAR ARE MORE THAN COMPENSATING...WITH SEVERAL REPORTS OF
HAIL ALREADY REPORTED ACROSS THE AREA TODAY. BROAD-SCALE ASCENT
SHOULD PERSIST THROUGH THE REST OF THIS AFTERNOON AND INTO
TONIGHT...WITH DEEP LAYER SHEAR AND INSTABILITY ALSO LIKELY
PERSISTING. IN ADDITION...VISIBLE SATELLITE IMAGERY INDICATES LOW
LEVEL CONVERGENCE...ALONG THE DIFFERENTIAL HEATING BOUNDARY ACROSS
WESTERN PORTIONS OF THE CWA...IS HELPING TO PROMOTE WEAK
CONVECTIVE ACTIVITY. FINALLY...KLNX INDICATES ADDITIONAL
CONVECTION FIRING ALONG THE SURFACE TROUGH ACROSS WESTERN
NEBRASKA. THE TROUGH ACROSS WESTERN NEBRASKA...AND THE
DIFFERENTIAL HEATING BOUNDARY OVER WESTERN PORTIONS OF THE
CWA...ARE EXPECTED TO PUSH ACROSS OUR CWA THIS EVENING AND TONIGHT
AS THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN
PLAINS...ALSO PUSHES EAST/SOUTHEAST. AT THIS TIME IT APPEARS THE
BULK OF THE BROAD-SCALE ASCENT AHEAD OF THE NORTHERN PLAINS MID
LEVEL TROUGH AXIS SHOULD REMAIN TO OUR NORTHEAST...BUT ADDITIONAL
CONVECTIVE ACTIVITY WILL BE POSSIBLE OVER OUR AREA THROUGH TONIGHT
AS THE SURFACE TROUGH AND DIFFERENTIAL HEATING
BOUNDARY/STRENGTHENING LOW LEVEL BAROCLINIC ZONE CLEARS THE AREA.
GIVEN ALL THIS...WENT AHEAD AND PRESENTED LIKELY TO DEFINITE POPS
ACROSS THE CWA THROUGH 06Z...WITH POPS TAPERING OFF AFTER 06Z AS
LOW LEVEL FORCING MOVES OFF TO THE EAST/SOUTHEAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND DEEP LAYER SHEAR...WILL ALSO
CONTINUE THE SEVERE WORDING ACROSS THE AREA THROUGH THIS EVENING.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCES FOR THUNDERSTORMS ON AND OFF DURING THE
PERIOD AND TEMPERATURES.
START OFF THE PERIOD WITH NORTHWEST FLOW THAT BRINGS SEVERAL WEAK
UPPER LEVEL WAVES THROUGH THE REGION THURSDAY NIGHT THROUGH
SATURDAY. THE BEST OF THOSE WAVES SEEMS TO BE DURING THE FRIDAY TO
FRIDAY NIGHT TIME FRAME.
SATURDAY NIGHT THROUGH TUESDAY THERE IS AN UPPER LEVEL RIDGE THAT
MOVES THROUGH THE PLAINS. TEMPERATURES WARM UP...BUT THERE REMAINS
SOME WEAK UPPER LEVEL WAVES THAT MOVE THROUGH THE AREA AND BRING
SOME SPORADIC CHANCES FOR THUNDERSTORMS TO THE FORECAST AREA.
TUESDAY NIGHT INTO WEDNESDAY AN UPPER LEVEL LOW BREAKS DOWN THE
RIDGE AND A SURFACE LOW IN THE SOUTHERN PLAINS HAS AN INVERTED
TROUGH TO THE NORTH ACROSS THE AREA. WITH THIS THERE IS A CHANCE FOR
SOME THUNDERSTORMS. TEMPERATURES WILL COOL A LITTLE BIT AGAIN AFTER
THE RIDGE BREAKS DOWN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...BRYANT
AVIATION/LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
311 PM EDT TUE MAY 29 2012
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS...SOME SEVERE...WILL FINISH MOVING
THROUGH THE AREA LATE AFTERNOON THROUGH EVENING. DRIER AIR WILL
FILL IN BEHIND THE ASSOCIATED COLD FRONT TONIGHT...BUT A SECOND
FRONT WILL STILL BRING ISOLATED TO SCATTERED SHOWERS WEDNESDAY.
EVEN COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...WITH DRY WEATHER. HOWEVER...A WETTER PERIOD IS
EXPECTED FRIDAY THROUGH A GOOD PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
3 PM UPDATE...
FORECAST TWEAKED FOR LATEST TRENDS AND OBSERVATIONS...BUT OVERALL
THINGS ARE EVOLVING PRETTY MUCH AS EXPECTED...WITH SEVERE WEATHER
OUTBREAK WELL UNDERWAY. ONE ADJUSTMENT THAT HAS BEEN MADE
THOUGH...IS TO FOCUS CONVECTION MORE EXCLUSIVELY ON THE VORTICITY
LOBE...AND MUCH LESS ON THE FRONT ITSELF. IN OTHER WORDS...APPEARS
TO BE ONE MAIN BATCH VERSUS TWO SEPARATE ONES.
WHAT BEGAN AS DISCRETE LARGE CELLS WITH LARGE HAIL...WITH GREATER
THAN 2K J/KG MIXED LAYER CAPE...IS EVOLVING WITH TIME TO MORE OF
AN ORGANIZED LINE WITH A HIGH WIND THREAT. ENTIRE CWA IS UNDER A
SEVERE THUNDERSTORM WATCH...AND ABOUT 13 WARNINGS HAVE BEEN ISSUED
FOR THE EVENT SO FAR. UPPER 80S TO LOWER 90S FOR TEMPERATURES
AHEAD OF THE STORMS...WITH DEWPOINTS OF UPPER 60S...YIELDED A VERY
UNSTABLE AIR MASS FOR THE APPROACHING WAVE AND COLD FRONT TO PLAY
WITH.
ALSO...1 HOUR FLASH FLOOD GUIDANCE IS MOSTLY AROUND 2
INCHES PLUS...WITH SOME SUB-COUNTY AREAS AS LOW AS 1.5 INCHES.
WHILE STORMS IN GENERAL WILL MOVE ALONG AT A GOOD ENOUGH PACE TO
PREVENT FLASH FLOODING...WE WILL HAVE TO MONITOR CLOSELY TO SEE IF
ANY SPECIFIC LOCATIONS THAT GET MORE THAN ONE STORM...COULD HAVE
LOCALIZED FLOOD ISSUES. AT THIS TIME...DOES NOT APPEAR TO ENOUGH OF AN
ORGANIZED AREAWIDE THREAT FOR A FLASH FLOOD WATCH...ONLY ISOLATED
AT BEST.
PREVIOUS DISCUSSION...
AFTER SOME EARLY MORNING CONVECTION NEAR THE TUG HILL
PLATEAU...FULL HEATING OCCURRING AREAWIDE WITH NEARLY CLOUD FREE
SKY. THIS ALONG WITH WEAK CAP EVIDENT IN MODELS /MOST CLEARLY IN
RUC/ AND BUF 12Z SOUNDING WILL SERVE TO ENHANCE INSTABILITY FOR
REMAINDER OF THE DAY. MESOANALYSIS REVEALS CAPES ALREADY IN EXCESS
OF 2000 J/KG IN SOME LOCATIONS...WHILE CAP IS BEGINNING TO WEAKEN
AND 500MB HEIGHT FALLS ARE OCCURRING. CONVECTIVE TEMPERATURE IN
BUF SOUNDING WAS 87 DEGREES...SYRACUSE AS OF 10 AM WAS ALREADY
HITTING IT.
FORECAST HAS BEEN UPDATED TO PLACE DETERMINISTIC POPS ON EXPECTED
CONVECTIVE EVOLUTION THROUGH TONIGHT. FIRST FEATURE OF NOTE IS A
WEAK VORTICITY LOBE THAT IS SET TO PASS THROUGH /AS DEPICTED BY
WRF-ARW VORTICITY FIELD AND HRRR QPF FIELD/ 16Z WEST TO 20Z EAST.
GIVEN GREAT DIURNAL HEATING TIMING AND WEAKENING CAP...THIS
FEATURE ALOFT SHOULD TIP THE SCALE AND RESULT IN AND ORGANIZED
CONVECTIVE LINE. GOOD DEEP LAYER SHEAR EXISTS FOR DAMAGING WINDS
AS A MAIN THREAT...WITH FAT CAPES BLASTING THROUGH AND BEYOND
MINUS-20 CELSIUS LEVEL...SUPPORTIVE OF LARGE HAIL. DIRECTIONAL
SHEAR IS PRETTY MUDDLED...BUT COULD BE ENOUGH FOR AT LEAST WEAK
MESOCYCLONES FOR ANY DISCRETE CELLS AHEAD OF MAIN LINE...OR
INTERSECTIONS OF BOWING SEGMENTS. CONVECTIVE PARAMETERS
OVERALL...COMPARED TO OUR DATABASE OF PAST EVENTS...ARE SUPPORTIVE
OF AT LEAST BROKEN LINES WITH BOWING SEGMENTS...WITH AT LEAST
SPORADIC DAMAGING WIND REPORTS IF NOT MORE ORGANIZED.
THIS IS NOT QUITE SO SIMPLE AS A SINGLE CONVECTIVE
LINE...HOWEVER. THE ACTUAL SURFACE FRONT LINGERS BEHIND...SET TO
ARRIVE 20Z OR SO WEST TO 01Z EAST. SOME MODELS SUGGEST THAT A
SECOND LINE COULD DEVELOP ALONG THIS SURFACE CONVERGENCE.
MESOSCALE INFLUENCES WILL DICTATE HOW QUICKLY AND HOW WELL THIS
SECONDARY LINE WILL ORGANIZE...INCLUDING INFLUENCES IN WAKE OF
FIRST LINE /THAT IS...HOW MUCH OF THE INSTABILITY IS USED UP/.
POPS HAVE BEEN UPDATED FOR THIS POTENTIAL SECOND BATCH...AND ALSO
CLEANED OUT LATER THIS EVENING AS CONVECTIVE ACTIVITY SHOULD
QUICKLY END BEHIND THE SURFACE FEATURE TONIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
3 PM UPDATE...
COLD AIR ADVECTION AND DRYING WILL OCCUR THROUGHOUT THE SHORT
TERM...HOWEVER...A PART OF THAT WILL BE A SECONDARY COLD FRONT
PASSING THROUGH WEDNESDAY. STEEP LAPSE RATES/DIURNAL HEATING WILL
HELP REALIZE SOME MARGINAL INSTABILITY. PRECIPITABLE WATER WILL BE
MUCH LOWER THAN TODAY...YET ADEQUATE ENOUGH FOR AT LEAST SOME
COVERAGE FOR DIURNALLY DRIVEN SHOWERS...ISOLATED TO
SCATTERED...ALONG WITH A SLIGHT CHANCE OF THUNDER.
COURTESY OF THAT SECONDARY FRONT...EVEN COOLER WEDNESDAY NIGHT
THROUGH ESPECIALLY THURSDAY NIGHT. NORTHWEST FLOW WILL INCLUDE
WEAK EMBEDDED WAVES...YET WITH PRECIPITABLE WATER DROPPING BELOW
TWO-THIRDS OF AN INCH...NOT EXPECTING ANYTHING MORE THAN SOME
DIURNAL CUMULUS AND WAS THUS ABLE TO KEEP MENTION OF
SPRINKLES/SHOWERS OUT OF THE FORECAST THURSDAY. TEMPERATURES IN
40S AREA WIDE BY DAWN FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
XTNDD PD FEATURES A LRG UPR LOW BRINGING UNSETTLED WX TO THE FCST
AREA. SFC FNTL BNDRY PASSES LATE FRI OR EARLY SAT USHERING IN
COOLER AIR AS THE UPR LOW SETTLES OVER THE ERN GREAT LAKES. AFT A
BRIEF PD OF DRY WX DIRECTLY BHD THE FNT...MOISTURE ASSOCIATED WITH
THE UPR LOW ROTATES INTO THE FCST AREA AND LINGERS THRU MUCH OF
THE PD. DAYTIME TEMPS WILL BE BLO NRML WITH H8 TEMPS TO ARND 8C.
LOW BEGINS TO LIFT LATE IN THE PD...BUT WAA MAY GENERATE A FEW
SHWRS THRU MON.
WITH ONGOING SVR WX...RELIED ON HPC GUID FOR MUCH OF THE XTNDD
PD...WITH ONLY A FEW MINOR ADJUSTMENTS.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
WIDESPREAD SVR WX XPCTD AHD OF AN APRCHG FNTL BNDRY INVOF ALL TAF
SITES. GUSTY WINDS WILL BE THE MAIN THREAT WITH LRG HAIL ALSO
PSBL. SLOW IMPRVMT XPCTD THIS EVE WITH THE LACK OF HTG AND AS THE
BNDRY PUSHES EWRD. SOME PTCHY MVFR PSBL IN ELM AS THE BNDRY LYR
DECPS LATE. VFR XPCTD WED AS MORE STABLE AIR MVES IN
.OUTLOOK...
WEDNESDAY NIGHT TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY THRU SUNDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
146 PM EDT TUE MAY 29 2012
.SYNOPSIS...
A COLD FRONT WILL RUN INTO A VERY WARM AND HUMID UNSTABLE AIR
MASS THIS AFTERNOON AND EVENING. THUNDERSTORMS WILL RESULT...SOME
OF WHICH COULD BE SEVERE WITH GUSTY WINDS AND HAIL. DRIER AIR
WILL FILL IN BEHIND THE COLD FRONT TONIGHT...BUT A SECOND FRONT
WILL STILL BRING A SLIGHT CHANCE OF A SHOWER WEDNESDAY. EVEN
COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...
FORECAST TWEAKED FOR LATEST TRENDS AND OBSERVATIONS...BUT OVERALL
THINGS ARE EVOLVING PRETTY MUCH AS EXPECTED...WITH SEVERE WEATHER
OUTBREAK JUST BEGINNING TO MOVE IN. ALL THAT HAS CHANGED IS THE
CERTAINTY /EVEN MORE/. SPC HAS UPGRADED MOST OF OUR AREA TO
MODERATE RISK OF SEVERE WEATHER...AND ENTIRE CWA IS NOW UNDER A
SEVERE THUNDERSTORM WATCH. MOSTLY UPPER 80S TO LOWER 90S FOR
TEMPERATURES...WITH DEWPOINTS OF UPPER 60S...HAS YIELDED A VERY
UNSTABLE AIR MASS FOR THE APPROACHING WAVE AND COLD FRONT TO PLAY
WITH. STORMS ARE ALREADY WIDESPREAD THROUGHOUT WESTERN
PA/NY...THROUGH THE MOHAWK VALLEY. REST OF DISCUSSION BELOW STILL
APPLIES.
ALSO...1 HOUR FLASH FLOOD GUIDANCE IS MOSTLY AROUND 2
INCHES PLUS...WITH SOME SUB-COUNTY AREAS AS LOW AS 1.5 INCHES.
WHILE STORMS IN GENERAL WILL MOVE ALONG AT A GOOD ENOUGH PACE TO
PREVENT FLASH FLOODING...WE WILL HAVE TO MONITOR CLOSELY TO SEE IF
ANY SPECIFIC LOCATIONS THAT GET MORE THAN ONE STORM...COULD HAVE
LOCALIZED FLOOD ISSUES. AT THIS TIME...DOES NOT APPEAR TO ENOUGH OF AN
ORGANIZED AREAWIDE THREAT FOR A FLASH FLOOD WATCH...ONLY ISOLATED
AT BEST.
PREVIOUS DISCUSSION...
AFTER SOME EARLY MORNING CONVECTION NEAR THE TUG HILL
PLATEAU...FULL HEATING OCCURRING AREAWIDE WITH NEARLY CLOUD FREE
SKY. THIS ALONG WITH WEAK CAP EVIDENT IN MODELS /MOST CLEARLY IN
RUC/ AND BUF 12Z SOUNDING WILL SERVE TO ENHANCE INSTABILITY FOR
REMAINDER OF THE DAY. MESOANALYSIS REVEALS CAPES ALREADY IN EXCESS
OF 2000 J/KG IN SOME LOCATIONS...WHILE CAP IS BEGINNING TO WEAKEN
AND 500MB HEIGHT FALLS ARE OCCURRING. CONVECTIVE TEMPERATURE IN
BUF SOUNDING WAS 87 DEGREES...SYRACUSE AS OF 10 AM WAS ALREADY
HITTING IT. SEVERE THUNDERSTORM WATCH HAS JUST BEEN ISSUED
INCLUDING SEVERAL OF OUR NORTHWESTERN ZONES...AND WE FIGURE THAT
IT IS LIKELY THAT THE REMAINDER OF THE AREA COULD BE PLACED IN A
LATER WATCH.
FORECAST HAS BEEN UPDATED TO PLACE DETERMINISTIC POPS ON EXPECTED
CONVECTIVE EVOLUTION THROUGH TONIGHT. FIRST FEATURE OF NOTE IS A
WEAK VORTICITY LOBE THAT IS SET TO PASS THROUGH /AS DEPICTED BY
WRF-ARW VORTICITY FIELD AND HRRR QPF FIELD/ 16Z WEST TO 20Z EAST.
GIVEN GREAT DIURNAL HEATING TIMING AND WEAKENING CAP...THIS
FEATURE ALOFT SHOULD TIP THE SCALE AND RESULT IN AND ORGANIZED
CONVECTIVE LINE. GOOD DEEP LAYER SHEAR EXISTS FOR DAMAGING WINDS
AS A MAIN THREAT...WITH FAT CAPES BLASTING THROUGH AND BEYOND
MINUS-20 CELSIUS LEVEL...SUPPORTIVE OF LARGE HAIL. DIRECTIONAL
SHEAR IS PRETTY MUDDLED...BUT COULD BE ENOUGH FOR AT LEAST WEAK
MESOCYCLONES FOR ANY DISCRETE CELLS AHEAD OF MAIN LINE...OR
INTERSECTIONS OF BOWING SEGMENTS. CONVECTIVE PARAMETERS
OVERALL...COMPARED TO OUR DATABASE OF PAST EVENTS...ARE SUPPORTIVE
OF AT LEAST BROKEN LINES WITH BOWING SEGMENTS...WITH AT LEAST
SPORADIC DAMAGING WIND REPORTS IF NOT MORE ORGANIZED.
THIS IS NOT QUITE SO SIMPLE AS A SINGLE CONVECTIVE
LINE...HOWEVER. THE ACTUAL SURFACE FRONT LINGERS BEHIND...SET TO
ARRIVE 20Z OR SO WEST TO 01Z EAST. SOME MODELS SUGGEST THAT A
SECOND LINE COULD DEVELOP ALONG THIS SURFACE
CONVERGENCE. MESOSCALE INFLUENCES WILL DICTATE HOW QUICKLY AND HOW
WELL THIS SECONDARY LINE WILL ORGANIZE...INCLUDING INFLUENCES IN
WAKE OF FIRST LINE /THAT IS...HOW MUCH OF THE INSTABILITY IS USED
UP/. POPS HAVE BEEN UPDATED FOR THIS POTENTIAL SECOND BATCH...AND
ALSO CLEANED OUT LATER THIS EVENING AS CONVECTIVE ACTIVITY SHOULD
QUICKLY END BEHIND THE SURFACE FEATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
4 AM UPDATE...
CAA AND DRYING WILL OCCUR THROUGHOUT THE SHORT TERM. WEDNESDAY A
WEAK SECONDARY COLD FRONT WILL MOVE THROUGH BUT MOISTURE WILL BE
WANING. SOME DIURNAL SHOWERS AND MAYBE A THUNDERSTORM MOSTLY
ACROSS THE TERRAIN. WED NGT MOSTLY PRECIP FREE AND COLDER WITH
MINS IN THE 50S TO A60. WITH DRYING FOG WILL NOT BE WIDESPREAD.
THURSDAY AGAIN COOLER. WEAK FORCING AND NW FLOW COULD CAUSE SOME
SHOWERS IN CENTRAL NY BUT ONLY SCHC. THURSDAY NIGHT LOWS IN THE
LOW AND MID 40S BEFORE TEMPERATURES MODERATE IN THE LONG TERM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
XTNDD PD FEATURES A LRG UPR LOW BRINGING UNSETTLED WX TO THE FCST
AREA. SFC FNTL BNDRY PASSES LATE FRI OR EARLY SAT USHERING IN
COOLER AIR AS THE UPR LOW SETTLES OVER THE ERN GREAT LAKES. AFT A
BRIEF PD OF DRY WX DIRECTLY BHD THE FNT...MOISTURE ASSOCIATED WITH
THE UPR LOW ROTATES INTO THE FCST AREA AND LINGERS THRU MUCH OF
THE PD. DAYTIME TEMPS WILL BE BLO NRML WITH H8 TEMPS TO ARND 8C.
LOW BEGINS TO LIFT LATE IN THE PD...BUT WAA MAY GENERATE A FEW
SHWRS THRU MON.
WITH ONGOING SVR WX...RELIED ON HPC GUID FOR MUCH OF THE XTNDD
PD...WITH ONLY A FEW MINOR ADJUSTMENTS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WIDESPREAD SVR WX XPCTD AHD OF AN APRCHG FNTL BNDRY INVOF ALL TAF
SITES. GUSTY WINDS WILL BE THE MAIN THREAT WITH LRG HAIL ALSO
PSBL. SLOW IMPRVMT XPCTD THIS EVE WITH THE LACK OF HTG AND AS THE
BNDRY PUSHES EWRD. SOME PTCHY MVFR PSBL IN ELM AS THE BNDRY LYR
DECPS LATE. VFR XPCTD WED AS MORE STABLE AIR MVES IN
.OUTLOOK...
WEDNESDAY NIGHT TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY THRU SUNDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
117 PM EDT TUE MAY 29 2012
.SYNOPSIS...
A COLD FRONT WILL RUN INTO A VERY WARM AND HUMID UNSTABLE AIR
MASS THIS AFTERNOON AND EVENING. THUNDERSTORMS WILL RESULT...SOME
OF WHICH COULD BE SEVERE WITH GUSTY WINDS AND HAIL. DRIER AIR
WILL FILL IN BEHIND THE COLD FRONT TONIGHT...BUT A SECOND FRONT
WILL STILL BRING A SLIGHT CHANCE OF A SHOWER WEDNESDAY. EVEN
COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...
FORECAST TWEAKED FOR LATEST TRENDS AND OBSERVATIONS...BUT OVERALL
THINGS ARE EVOLVING PRETTY MUCH AS EXPECTED...WITH SEVERE WEATHER
OUTBREAK JUST BEGINNING TO MOVE IN. ALL THAT HAS CHANGED IS THE
CERTAINTY /EVEN MORE/. SPC HAS UPGRADED MOST OF OUR AREA TO
MODERATE RISK OF SEVERE WEATHER...AND ENTIRE CWA IS NOW UNDER A
SEVERE THUNDERSTORM WATCH. MOSTLY UPPER 80S TO LOWER 90S FOR
TEMPERATURES...WITH DEWPOINTS OF UPPER 60S...HAS YIELDED A VERY
UNSTABLE AIR MASS FOR THE APPROACHING WAVE AND COLD FRONT TO PLAY
WITH. STORMS ARE ALREADY WIDESPREAD THROUGHOUT WESTERN
PA/NY...THROUGH THE MOHAWK VALLEY. REST OF DISCUSSION BELOW STILL
APPLIES.
ALSO...1 HOUR FLASH FLOOD GUIDANCE IS MOSTLY AROUND 2
INCHES PLUS...WITH SOME SUB-COUNTY AREAS AS LOW AS 1.5 INCHES.
WHILE STORMS IN GENERAL WILL MOVE ALONG AT A GOOD ENOUGH PACE TO
PREVENT FLASH FLOODING...WE WILL HAVE TO MONITOR CLOSELY TO SEE IF
ANY SPECIFIC LOCATIONS THAT GET MORE THAN ONE STORM...COULD HAVE
LOCALIZED FLOOD ISSUES. AT THIS TIME...DOES NOT APPEAR TO ENOUGH OF AN
ORGANIZED AREAWIDE THREAT FOR A FLASH FLOOD WATCH...ONLY ISOLATED
AT BEST.
PREVIOUS DISCUSSION...
AFTER SOME EARLY MORNING CONVECTION NEAR THE TUG HILL
PLATEAU...FULL HEATING OCCURRING AREAWIDE WITH NEARLY CLOUD FREE
SKY. THIS ALONG WITH WEAK CAP EVIDENT IN MODELS /MOST CLEARLY IN
RUC/ AND BUF 12Z SOUNDING WILL SERVE TO ENHANCE INSTABILITY FOR
REMAINDER OF THE DAY. MESOANALYSIS REVEALS CAPES ALREADY IN EXCESS
OF 2000 J/KG IN SOME LOCATIONS...WHILE CAP IS BEGINNING TO WEAKEN
AND 500MB HEIGHT FALLS ARE OCCURRING. CONVECTIVE TEMPERATURE IN
BUF SOUNDING WAS 87 DEGREES...SYRACUSE AS OF 10 AM WAS ALREADY
HITTING IT. SEVERE THUNDERSTORM WATCH HAS JUST BEEN ISSUED
INCLUDING SEVERAL OF OUR NORTHWESTERN ZONES...AND WE FIGURE THAT
IT IS LIKELY THAT THE REMAINDER OF THE AREA COULD BE PLACED IN A
LATER WATCH.
FORECAST HAS BEEN UPDATED TO PLACE DETERMINISTIC POPS ON EXPECTED
CONVECTIVE EVOLUTION THROUGH TONIGHT. FIRST FEATURE OF NOTE IS A
WEAK VORTICITY LOBE THAT IS SET TO PASS THROUGH /AS DEPICTED BY
WRF-ARW VORTICITY FIELD AND HRRR QPF FIELD/ 16Z WEST TO 20Z EAST.
GIVEN GREAT DIURNAL HEATING TIMING AND WEAKENING CAP...THIS
FEATURE ALOFT SHOULD TIP THE SCALE AND RESULT IN AND ORGANIZED
CONVECTIVE LINE. GOOD DEEP LAYER SHEAR EXISTS FOR DAMAGING WINDS
AS A MAIN THREAT...WITH FAT CAPES BLASTING THROUGH AND BEYOND
MINUS-20 CELSIUS LEVEL...SUPPORTIVE OF LARGE HAIL. DIRECTIONAL
SHEAR IS PRETTY MUDDLED...BUT COULD BE ENOUGH FOR AT LEAST WEAK
MESOCYCLONES FOR ANY DISCRETE CELLS AHEAD OF MAIN LINE...OR
INTERSECTIONS OF BOWING SEGMENTS. CONVECTIVE PARAMETERS
OVERALL...COMPARED TO OUR DATABASE OF PAST EVENTS...ARE SUPPORTIVE
OF AT LEAST BROKEN LINES WITH BOWING SEGMENTS...WITH AT LEAST
SPORADIC DAMAGING WIND REPORTS IF NOT MORE ORGANIZED.
THIS IS NOT QUITE SO SIMPLE AS A SINGLE CONVECTIVE
LINE...HOWEVER. THE ACTUAL SURFACE FRONT LINGERS BEHIND...SET TO
ARRIVE 20Z OR SO WEST TO 01Z EAST. SOME MODELS SUGGEST THAT A
SECOND LINE COULD DEVELOP ALONG THIS SURFACE
CONVERGENCE. MESOSCALE INFLUENCES WILL DICTATE HOW QUICKLY AND HOW
WELL THIS SECONDARY LINE WILL ORGANIZE...INCLUDING INFLUENCES IN
WAKE OF FIRST LINE /THAT IS...HOW MUCH OF THE INSTABILITY IS USED
UP/. POPS HAVE BEEN UPDATED FOR THIS POTENTIAL SECOND BATCH...AND
ALSO CLEANED OUT LATER THIS EVENING AS CONVECTIVE ACTIVITY SHOULD
QUICKLY END BEHIND THE SURFACE FEATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
4 AM UPDATE...
CAA AND DRYING WILL OCCUR THROUGHOUT THE SHORT TERM. WEDNESDAY A
WEAK SECONDARY COLD FRONT WILL MOVE THROUGH BUT MOISTURE WILL BE
WANING. SOME DIURNAL SHOWERS AND MAYBE A THUNDERSTORM MOSTLY
ACROSS THE TERRAIN. WED NGT MOSTLY PRECIP FREE AND COLDER WITH
MINS IN THE 50S TO A60. WITH DRYING FOG WILL NOT BE WIDESPREAD.
THURSDAY AGAIN COOLER. WEAK FORCING AND NW FLOW COULD CAUSE SOME
SHOWERS IN CENTRAL NY BUT ONLY SCHC. THURSDAY NIGHT LOWS IN THE
LOW AND MID 40S BEFORE TEMPERATURES MODERATE IN THE LONG TERM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
XTNDD PD FEATURES A LRG UPR LOW BRINGING UNSETTLED WX TO THE FCST
AREA. SFC FNTL BNDRY PASSES LATE FRI OR EARLY SAT USHERING IN
COOLER AIR AS THE UPR LOW SETTLES OVER THE ERN GREAT LAKES. AFT A
BRIEF PD OF DRY WX DIRECTLY BHD THE FNT...MOISTURE ASSOCIATED WITH
THE UPR LOW ROTATES INTO THE FCST AREA AND LINGERS THRU MUCH OF
THE PD. DAYTIME TEMPS WILL BE BLO NRML WITH H8 TEMPS TO ARND 8C.
LOW BEGINS TO LIFT LATE IN THE PD...BUT WAA MAY GENERATE A FEW
SHWRS THRU MON.
WITH ONGOING SVR WX...RELIED ON HPC GUID FOR MUCH OF THE XTNDD
PD...WITH ONLY A FEW MINOR ADJUSTMENTS.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
FOG DID NOT DEVELOP THIS MORNING AS TEMPERATURES UNEXPECTEDLY ROSE
OVERNIGHT, INCREASING DEWPOINT DEPRESSIONS. THE MAIN CONCERN NOW
TURNS TO CONVECTION.
SCATTERED CONVECTION IS EXPECTED FROM JUST NORTH OF SYR TO JUST
NORTH OF RME THROUGH MID MORNING. THEREAFTER CONVECTION WILL
INCREASE IN COVERAGE AND INTENSITY.
THE BEST CHANCE FOR CONVECTION WILL BE BETWEEN 17Z AND 23Z.
THUNDERSTORMS WILL PRODUCE HAIL, HEAVY RAIN, AND GUSTY WINDS.
TEMPORARY MVFR RESTRICTIONS ARE EXPECTED IN THUNDERSTORMS.
.OUTLOOK...
WEDNESDAY TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY AND SATURDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...DGM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1211 PM EDT TUE MAY 29 2012
.SYNOPSIS...
A COLD FRONT WILL RUN INTO A VERY WARM AND HUMID UNSTABLE AIR
MASS THIS AFTERNOON AND EVENING. THUNDERSTORMS WILL RESULT...SOME
OF WHICH COULD BE SEVERE WITH GUSTY WINDS AND HAIL. DRIER AIR
WILL FILL IN BEHIND THE COLD FRONT TONIGHT...BUT A SECOND FRONT
WILL STILL BRING A SLIGHT CHANCE OF A SHOWER WEDNESDAY. EVEN
COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...AFTER SOME EARLY MORNING CONVECTION NEAR THE TUG
HILL PLATEAU...FULL HEATING OCCURRING AREAWIDE WITH NEARLY CLOUD
FREE SKY. THIS ALONG WITH WEAK CAP EVIDENT IN MODELS /MOST CLEARLY
IN RUC/ AND BUF 12Z SOUNDING WILL SERVE TO ENHANCE INSTABILITY FOR
REMAINDER OF THE DAY. MESOANALYSIS REVEALS CAPES ALREADY IN EXCESS
OF 2000 J/KG IN SOME LOCATIONS...WHILE CAP IS BEGINNING TO WEAKEN
AND 500MB HEIGHT FALLS ARE OCCURRING. CONVECTIVE TEMPERATURE IN
BUF SOUNDING WAS 87 DEGREES...SYRACUSE AS OF 10 AM WAS ALREADY
HITTING IT. SEVERE THUNDERSTORM WATCH HAS JUST BEEN ISSUED
INCLUDING SEVERAL OF OUR NORTHWESTERN ZONES...AND WE FIGURE THAT
IT IS LIKELY THAT THE REMAINDER OF THE AREA COULD BE PLACED IN A
LATER WATCH.
FORECAST HAS BEEN UPDATED TO PLACE DETERMINISTIC POPS ON EXPECTED
CONVECTIVE EVOLUTION THROUGH TONIGHT. FIRST FEATURE OF NOTE IS A
WEAK VORTICITY LOBE THAT IS SET TO PASS THROUGH /AS DEPICTED BY
WRF-ARW VORTICITY FIELD AND HRRR QPF FIELD/ 16Z WEST TO 20Z EAST.
GIVEN GREAT DIURNAL HEATING TIMING AND WEAKENING CAP...THIS
FEATURE ALOFT SHOULD TIP THE SCALE AND RESULT IN AND ORGANIZED
CONVECTIVE LINE. GOOD DEEP LAYER SHEAR EXISTS FOR DAMAGING WINDS
AS A MAIN THREAT...WITH FAT CAPES BLASTING THROUGH AND BEYOND
MINUS-20 CELSIUS LEVEL...SUPPORTIVE OF LARGE HAIL. DIRECTIONAL
SHEAR IS PRETTY MUDDLED...BUT COULD BE ENOUGH FOR AT LEAST WEAK
MESOCYCLONES FOR ANY DISCRETE CELLS AHEAD OF MAIN LINE...OR
INTERSECTIONS OF BOWING SEGMENTS. CONVECTIVE PARAMETERS
OVERALL...COMPARED TO OUR DATABASE OF PAST EVENTS...ARE SUPPORTIVE
OF AT LEAST BROKEN LINES WITH BOWING SEGMENTS...WITH AT LEAST
SPORADIC DAMAGING WIND REPORTS IF NOT MORE ORGANIZED.
THIS IS NOT QUITE SO SIMPLE AS A SINGLE CONVECTIVE
LINE...HOWEVER. THE ACTUAL SURFACE FRONT LINGERS BEHIND...SET TO
ARRIVE 20Z OR SO WEST TO 01Z EAST. SOME MODELS SUGGEST THAT A
SECOND LINE COULD DEVELOP ALONG THIS SURFACE
CONVERGENCE. MESOSCALE INFLUENCES WILL DICTATE HOW QUICKLY AND HOW
WELL THIS SECONDARY LINE WILL ORGANIZE...INCLUDING INFLUENCES IN
WAKE OF FIRST LINE /THAT IS...HOW MUCH OF THE INSTABILITY IS USED
UP/. POPS HAVE BEEN UPDATED FOR THIS POTENTIAL SECOND BATCH...AND
ALSO CLEANED OUT LATER THIS EVENING AS CONVECTIVE ACTIVITY SHOULD
QUICKLY END BEHIND THE SURFACE FEATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
4 AM UPDATE...
CAA AND DRYING WILL OCCUR THROUGHOUT THE SHORT TERM. WEDNESDAY A
WEAK SECONDARY COLD FRONT WILL MOVE THROUGH BUT MOISTURE WILL BE
WANING. SOME DIURNAL SHOWERS AND MAYBE A THUNDERSTORM MOSTLY
ACROSS THE TERRAIN. WED NGT MOSTLY PRECIP FREE AND COLDER WITH
MINS IN THE 50S TO A60. WITH DRYING FOG WILL NOT BE WIDESPREAD.
THURSDAY AGAIN COOLER. WEAK FORCING AND NW FLOW COULD CAUSE SOME
SHOWERS IN CENTRAL NY BUT ONLY SCHC. THURSDAY NIGHT LOWS IN THE
LOW AND MID 40S BEFORE TEMPERATURES MODERATE IN THE LONG TERM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
XTNDD PD FEATURES A LRG UPR LOW BRINGING UNSETTLED WX TO THE FCST
AREA. SFC FNTL BNDRY PASSES LATE FRI OR EARLY SAT USHERING IN
COOLER AIR AS THE UPR LOW SETTLES OVER THE ERN GREAT LAKES. AFT A
BRIEF PD OF DRY WX DIRECTLY BHD THE FNT...MOISTURE ASSOCIATED WITH
THE UPR LOW ROTATES INTO THE FCST AREA AND LINGERS THRU MUCH OF
THE PD. DAYTIME TEMPS WILL BE BLO NRML WITH H8 TEMPS TO ARND 8C.
LOW BEGINS TO LIFT LATE IN THE PD...BUT WAA MAY GENERATE A FEW
SHWRS THRU MON.
WITH ONGOING SVR WX...RELIED ON HPC GUID FOR MUCH OF THE XTNDD
PD...WITH ONLY A FEW MINOR ADJUSTMENTS.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
FOG DID NOT DEVELOP THIS MORNING AS TEMPERATURES UNEXPECTEDLY ROSE
OVERNIGHT, INCREASING DEWPOINT DEPRESSIONS. THE MAIN CONCERN NOW
TURNS TO CONVECTION.
SCATTERED CONVECTION IS EXPECTED FROM JUST NORTH OF SYR TO JUST
NORTH OF RME THROUGH MID MORNING. THEREAFTER CONVECTION WILL
INCREASE IN COVERAGE AND INTENSITY.
THE BEST CHANCE FOR CONVECTION WILL BE BETWEEN 17Z AND 23Z.
THUNDERSTORMS WILL PRODUCE HAIL, HEAVY RAIN, AND GUSTY WINDS.
TEMPORARY MVFR RESTRICTIONS ARE EXPECTED IN THUNDERSTORMS.
.OUTLOOK...
WEDNESDAY TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY AND SATURDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...DGM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1048 AM EDT TUE MAY 29 2012
.SYNOPSIS...
A COLD FRONT WILL RUN INTO A VERY WARM AND HUMID UNSTABLE AIR
MASS THIS AFTERNOON AND EVENING. THUNDERSTORMS WILL RESULT...SOME
OF WHICH COULD BE SEVERE WITH GUSTY WINDS AND HAIL. DRIER AIR
WILL FILL IN BEHIND THE COLD FRONT TONIGHT...BUT A SECOND FRONT
WILL STILL BRING A SLIGHT CHANCE OF A SHOWER WEDNESDAY. EVEN
COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...AFTER SOME EARLY MORNING CONVECTION NEAR THE TUG
HILL PLATEAU...FULL HEATING OCCURRING AREAWIDE WITH NEARLY CLOUD
FREE SKY. THIS ALONG WITH WEAK CAP EVIDENT IN MODELS /MOST CLEARLY
IN RUC/ AND BUF 12Z SOUNDING WILL SERVE TO ENHANCE INSTABILITY FOR
REMAINDER OF THE DAY. MESOANALYSIS REVEALS CAPES ALREADY IN EXCESS
OF 2000 J/KG IN SOME LOCATIONS...WHILE CAP IS BEGINNING TO WEAKEN
AND 500MB HEIGHT FALLS ARE OCCURRING. CONVECTIVE TEMPERATURE IN
BUF SOUNDING WAS 87 DEGREES...SYRACUSE AS OF 10 AM WAS ALREADY
HITTING IT. SEVERE THUNDERSTORM WATCH HAS JUST BEEN ISSUED
INCLUDING SEVERAL OF OUR NORTHWESTERN ZONES...AND WE FIGURE THAT
IT IS LIKELY THAT THE REMAINDER OF THE AREA COULD BE PLACED IN A
LATER WATCH.
FORECAST HAS BEEN UPDATED TO PLACE DETERMINISTIC POPS ON EXPECTED
CONVECTIVE EVOLUTION THROUGH TONIGHT. FIRST FEATURE OF NOTE IS A
WEAK VORTICITY LOBE THAT IS SET TO PASS THROUGH /AS DEPICTED BY
WRF-ARW VORTICITY FIELD AND HRRR QPF FIELD/ 16Z WEST TO 20Z EAST.
GIVEN GREAT DIURNAL HEATING TIMING AND WEAKENING CAP...THIS
FEATURE ALOFT SHOULD TIP THE SCALE AND RESULT IN AND ORGANIZED
CONVECTIVE LINE. GOOD DEEP LAYER SHEAR EXISTS FOR DAMAGING WINDS
AS A MAIN THREAT...WITH FAT CAPES BLASTING THROUGH AND BEYOND
MINUS-20 CELSIUS LEVEL...SUPPORTIVE OF LARGE HAIL. DIRECTIONAL
SHEAR IS PRETTY MUDDLED...BUT COULD BE ENOUGH FOR AT LEAST WEAK
MESOCYCLONES FOR ANY DISCRETE CELLS AHEAD OF MAIN LINE...OR
INTERSECTIONS OF BOWING SEGMENTS. CONVECTIVE PARAMETERS
OVERALL...COMPARED TO OUR DATABASE OF PAST EVENTS...ARE SUPPORTIVE
OF AT LEAST BROKEN LINES WITH BOWING SEGMENTS...WITH AT LEAST
SPORADIC DAMAGING WIND REPORTS IF NOT MORE ORGANIZED.
THIS IS NOT QUITE SO SIMPLE AS A SINGLE CONVECTIVE
LINE...HOWEVER. THE ACTUAL SURFACE FRONT LINGERS BEHIND...SET TO
ARRIVE 20Z OR SO WEST TO 01Z EAST. SOME MODELS SUGGEST THAT A
SECOND LINE COULD DEVELOP ALONG THIS SURFACE
CONVERGENCE. MESOSCALE INFLUENCES WILL DICTATE HOW QUICKLY AND HOW
WELL THIS SECONDARY LINE WILL ORGANIZE...INCLUDING INFLUENCES IN
WAKE OF FIRST LINE /THAT IS...HOW MUCH OF THE INSTABILITY IS USED
UP/. POPS HAVE BEEN UPDATED FOR THIS POTENTIAL SECOND BATCH...AND
ALSO CLEANED OUT LATER THIS EVENING AS CONVECTIVE ACTIVITY SHOULD
QUICKLY END BEHIND THE SURFACE FEATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
4 AM UPDATE...
CAA AND DRYING WILL OCCUR THROUGHOUT THE SHORT TERM. WEDNESDAY A
WEAK SECONDARY COLD FRONT WILL MOVE THROUGH BUT MOISTURE WILL BE
WANING. SOME DIURNAL SHOWERS AND MAYBE A THUNDERSTORM MOSTLY
ACROSS THE TERRAIN. WED NGT MOSTLY PRECIP FREE AND COLDER WITH
MINS IN THE 50S TO A60. WITH DRYING FOG WILL NOT BE WIDESPREAD.
THURSDAY AGAIN COOLER. WEAK FORCING AND NW FLOW COULD CAUSE SOME
SHOWERS IN CENTRAL NY BUT ONLY SCHC. THURSDAY NIGHT LOWS IN THE
LOW AND MID 40S BEFORE TEMPERATURES MODERATE IN THE LONG TERM.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
105 PM UPDATE...
THOUGH THE 12Z GFS AND 00Z ECMWF DISAGREE ON THE DETAILS...BUT
THERE IS DECENT OVERALL OVERALL PATTERN AGREEMENT. A CUT OFF LOW
MOVES IN FROM EITHER THE PLAINS OR THE UPPER MIDWEST LATE IN THE
WEEK AND INTO THE WEEKEND...WHILE AN ASSOCIATED NEGATIVELY TILTED
COLD/OCCLUDED FRONT COMES AT US FROM THE MID MISSISSIPPI RIVER
VALLEY. GENERALLY WENT ALONG WITH HPC FORECAST...EXCEPT FOR
SCALING BACK POPS TO JUST CHANCE RANGE SATURDAY NIGHT/SUNDAY
BECAUSE OF UNCERTAINTY FOR HOW LONG IT TAKES UPPER LOW TO MOVE
OUT...AND HOW MUCH DRY AIR GETS INVOLVED ON THE BACK SIDE OF IT.
GFS IS DIGS QUITE A BIT DEEPER WITH THE CUT OFF LOW...AND THUS IS
ALSO SLOWER IN THE EVOLUTION OF THINGS THROUGH THE WEEKEND. ECMWF
IS A LITTLE MORE PROGRESSIVE. EITHER WAY...A WET PERIOD IS IN
STORE...CENTERED ON FRIDAY NIGHT INTO SATURDAY. ONLY QUESTIONS ARE
TIMING ON THE FRONT END FRIDAY...AND THE BACK END SUNDAY. EMBEDDED
THUNDER FROM MARGINAL INSTABILITY IS NOT OUT OF THE
QUESTION...PARTICULARLY IF THINGS TAKE A MORE NEGATIVE TILT LIKE
THE GFS...BUT FOR NOW WITH HPC LEANING TOWARDS ECMWF...I HAVE LEFT
MENTION OF IT OUT. I HAVE THUS ALSO HAVE GONE WITH THE COOLER
HPC TEMPERATURES FOR SATURDAY.
UPPER LOW GRADUALLY PULLS AWAY TOWARDS THE END OF THE
WEEKEND...THOUGH STILL WITH SOME SORT OF CYCLONIC NORTHWESTERLY
FLOW LASTING PERHAPS EVEN INTO MONDAY. I HAVE CHANCE POPS
SUNDAY...BUT LESS THAN THAT SUNDAY NIGHT/MONDAY WITH LACK OF
CERTAINTY...AND WITH DRIER ATMOSPHERE AS WELL AS RISING HEIGHTS
HEADING INTO EARLY NEXT WEEK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
FOG DID NOT DEVELOP THIS MORNING AS TEMPERATURES UNEXPECTEDLY ROSE
OVERNIGHT, INCREASING DEWPOINT DEPRESSIONS. THE MAIN CONCERN NOW
TURNS TO CONVECTION.
SCATTERED CONVECTION IS EXPECTED FROM JUST NORTH OF SYR TO JUST
NORTH OF RME THROUGH MID MORNING. THEREAFTER CONVECTION WILL
INCREASE IN COVERAGE AND INTENSITY.
THE BEST CHANCE FOR CONVECTION WILL BE BETWEEN 17Z AND 23Z.
THUNDERSTORMS WILL PRODUCE HAIL, HEAVY RAIN, AND GUSTY WINDS.
TEMPORARY MVFR RESTRICTIONS ARE EXPECTED IN THUNDERSTORMS.
.OUTLOOK...
WEDNESDAY TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY AND SATURDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...MDP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
126 AM EDT TUE MAY 29 2012
.SYNOPSIS...
AFTER A HOT AND MUGGY MEMORIAL DAY...A COUPLE SHOWERS AND
THUNDERSTORMS ARE POSSIBLE IN THE AREA TONIGHT. HOWEVER...A MUCH
BETTER LIKELIHOOD FOR THUNDER WILL OCCUR TUESDAY...AS A COLD FRONT
APPROACHES AND RUNS INTO A VERY WARM AND HUMID UNSTABLE AIR MASS.
SOME OF THE STORMS COULD BE SEVERE WITH GUSTY WINDS AND HAIL.
DRIER FRESH AIR WILL FILL IN BEHIND THE FIRST FRONT...BUT A
SECOND FRONT WILL STILL BRING A SLIGHT CHANCE OF A SHOWER OR
THUNDERSTORM WEDNESDAY. COOLER TEMPERATURES WILL FOLLOW FOR WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1050 PM UPDATE...REMOVED POPS FROM THE AREA FOR THE NEXT FEW
HOURS. WE ARE WATCHING A SHORT WAVE OVER NWPA NOW THAT WILL MOVE
INTO THE LAKE PLAIN AFTER MIDNIGHT. WITH SBCAPES STILL IN THE 1000
TO 2000 J/KG RANGE WE HAVE PLENTY OF INSTABILITY TO WORK WITH BUT
THE 0Z KBUF SOUNDING SHOWS WE HAVE A MID LEVEL CAP AROUND 800 MB.
STILL FELT SLIGHT CHANCE WAS THE WAY TO GO FROM 05Z THROUGH 09Z
OVER THE LAKE PLAIN DUE TO THE SHORT WAVE MOVING THROUGH.
CONTINUED CHANCE POPS ACROSS CNY IN THE 07Z TO 10Z TIME-FRAME AS
BOTH THE NEW 0Z NAM AND HRRR SHOW A POSSIBLE MCS TRACKING ACROSS
NNY DURING THIS TIME. FEEL THE HIGHEST THREAT FOR THIS TO OCCUR
WILL BE JUST NORTH OF OUR CWA BUT CHANCE POPS ON THE SOUTHERN EDGE
OF THIS LOOK GOOD. GUSTY WINDS AND HEAVY RAIN ARE A DISTINCT
POSSIBILITY IF THIS MCS FORMS.
615 PM UPDATE...BASED ON DISSIPATING CU FIELDS AND THE LACK OF
ANYTHING ON RADAR CONTINUE TO CUT BACK ON POPS. AN INITIAL UPDATE
2 HOURS AGO DOWN TO SLIGHT CHANCE STILL LOOKS GOOD. I DID TRIM
POPS BACK TO NOTHING ROUGHLY WEST OF I-81. SOME SLIGHTLY HIGHER
CLOUD TOPS ON A LINE FROM NEAR MONTROSE SOUTH TOWARD KAVP MOVING
EAST...OTHERWISE THE CU IS CLEARING OUT AS WE SPEAK. WILL CONTINUE
TO MONITOR THE RADAR CLOSELY WITH SBCAPES AROUND 3000 J/KG AND
PLENTY OF MOISTURE AROUND. OUR LACKING THIRD INGREDIENT...A
LIFTING MECHANISM OR TRIGGER...IS NOT APPARENT. IN ADDITION TO THE
LACK OF A TRIGGER WARM MID LEVELS HAS PUT A NICE CAP ON ANYTHING.
LATE TONIGHT SOME OF THE HI RES MODELS SUGGEST OUR NORTHERN ZONES
MAY BE ON THE SOUTHERN EDGE OF A POSSIBLE MCS AS H5 SHORT WAVE
MOVES OVER THE TOP OF THE RIDGE. WILL CONTINUE WITH CHANCE POPS LATE
TONIGHT ACROSS CNY TO ACCOUNT FOR THIS. PREVIOUS AFD IS BELOW...
2 PM UPDATE...CLUSTER OF STORMS MOVED SOUTHEAST OVER THE EASTERN
HALF OF THE NY ZONES THIS MORNING. GOT SOME REPORTS OF PEA TO DIME
SIZE HAIL FROM THE STRONGEST CELLS. SKIES HAVE CLEARED WITH A
MESO HIGH BUBBLE OVER THE NE ZONES. BOUNDARY LIES FROM NY/PA
BORDER NW ACROSS STEUBEN COUNTY WITH SCATTER CUMULUS BUILDING OVER
THE HILLS. FEW SHOWERS DEVELOPING IN THIS. SHOULD CONTINUE TO
DESTABILIZE INTO THE LATE AFTERNOON. LOOKS LIKE ANOTHER WEAK SHORT
WAVE MOVING OVER THE RIDGE THIS AFTERNOON THAT MAY HELP. IF WE CAN
PASS THE CIN WE HAVE POTENTIAL FOR SEVERE AND ARE WATCHING THE
DEVELOPMENT CLOSELY AS IS SPC FOR THE NEED FOR WATCH/WARNING.
MODIFIED TEMPERATURES AND DEW POINTS FOR CURRENT TRENDS. TEMPS
SHOULD REBOUND QUICKLY WHERE SHOWERS OCCURRED...SO DID CHANGE THE
EXPECTED MAX HIGHS. SHOWERS JUST MADE IT FEEL MUGGIER.
OVERNIGHT SOUNDING SHOW IT STABILIZING IN THE LOWEST LAYER BUT
STILL A LOT OF ELEVATED CAPE SHOULD SOMETHING COME OVER THE UPPER
LEVEL RIDGE TO TRIGGER IT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
430 PM UPDATE...
MODELS STILL INDICATE A FAIRLY GOOD SET UP FOR STRONG CONVECTIVE
EVENT ON TUESDAY. NOT QUITE AS MUCH CAPE AS TODAY /MEMORIAL
DAY/...BUT WITH UPPER RIDGE AXIS SHIFTING WELL TO OUR EAST AND
RESULTANT HEIGHT FALLS...CONVECTIVE INHIBITION WILL BE REMOVED. A
WARM AND HUMID AIRMASS OVER THE REGION CAPE VALUES AROUND
1500-2000 J/KG...AND DECENT SHEAR...AMONG OTHER PARAMETERS...ARE
SHOWING SEVERE POTENTIAL. DAMAGING WIND FROM POSSIBLE BOW SEGMENTS
APPEARS TO BE THE PRIMARY THREAT...THOUGH WE WILL HAVE TO MONITOR
CELLS /ESPECIALLY FIRST ONES THAT DEVELOP ASSOCIATED WITH
PREFRONTAL TROUGH/ FOR MESOCYCLONES AND LARGE HAIL. AS OF 430
PM...STORM PREDICTION CENTER HAS ENTIRE REGION IN SLIGHT RISK FOR
SEVERE THUNDERSTORMS TUESDAY. MAX TEMPS IN 80S AND DEWPOINTS IN
MID 60S YIELDS ANOTHER CASE OF THE MUGGIES.
REMAINDER OF CONVECTION WILL QUICKLY SCOOT EAST TUESDAY EVENING
BEFORE ENDING...WITH THE REAL COLD FRONT LIKELY PASSING THROUGH
FAIRLY QUIETLY OVERNIGHT. THIS WILL REALLY DROP DEWPOINTS INTO
WEDNESDAY...WELL INTO THE 50S AND PERHAPS EVEN A FEW UPPER 40S.
WITH VERY LIMITED MOISTURE...SECONDARY FRONT PASSING WEDNESDAY
AFTERNOON SHOULD ONLY HAVE ISOLATED COVERAGE TO ANY CONVECTION
THAT DEVELOPS.
BEHIND SECONDARY FRONT...HIGH TEMPERATURES THURSDAY WILL BE
ANOTHER GOOD 10 OR SO DEGREES COOLER THAN WEDNESDAY /WHICH WILL
ALREADY BE COOLER THAN TUESDAY/...AND DEWPOINTS WILL PLUMMET WELL
INTO THE 40S. SURFACE HIGH PRESSURE WILL BE BUILDING IN...BUT AN
UPPER TROUGH AXIS SKIMMING BY THE NORTHERN ZONES COULD YIELD A FEW
POSSIBLE SPRINKLES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
105 PM UPDATE...
THOUGH THE 12Z GFS AND 00Z ECMWF DISAGREE ON THE DETAILS...BUT
THERE IS DECENT OVERALL OVERALL PATTERN AGREEMENT. A CUT OFF LOW
MOVES IN FROM EITHER THE PLAINS OR THE UPPER MIDWEST LATE IN THE
WEEK AND INTO THE WEEKEND...WHILE AN ASSOCIATED NEGATIVELY TILTED
COLD/OCCLUDED FRONT COMES AT US FROM THE MID MISSISSIPPI RIVER
VALLEY. GENERALLY WENT ALONG WITH HPC FORECAST...EXCEPT FOR
SCALING BACK POPS TO JUST CHANCE RANGE SATURDAY NIGHT/SUNDAY
BECAUSE OF UNCERTAINTY FOR HOW LONG IT TAKES UPPER LOW TO MOVE
OUT...AND HOW MUCH DRY AIR GETS INVOLVED ON THE BACK SIDE OF IT.
GFS IS DIGS QUITE A BIT DEEPER WITH THE CUT OFF LOW...AND THUS IS
ALSO SLOWER IN THE EVOLUTION OF THINGS THROUGH THE WEEKEND. ECMWF
IS A LITTLE MORE PROGRESSIVE. EITHER WAY...A WET PERIOD IS IN
STORE...CENTERED ON FRIDAY NIGHT INTO SATURDAY. ONLY QUESTIONS ARE
TIMING ON THE FRONT END FRIDAY...AND THE BACK END SUNDAY. EMBEDDED
THUNDER FROM MARGINAL INSTABILITY IS NOT OUT OF THE
QUESTION...PARTICULARLY IF THINGS TAKE A MORE NEGATIVE TILT LIKE
THE GFS...BUT FOR NOW WITH HPC LEANING TOWARDS ECMWF...I HAVE LEFT
MENTION OF IT OUT. I HAVE THUS ALSO HAVE GONE WITH THE COOLER
HPC TEMPERATURES FOR SATURDAY.
UPPER LOW GRADUALLY PULLS AWAY TOWARDS THE END OF THE
WEEKEND...THOUGH STILL WITH SOME SORT OF CYCLONIC NORTHWESTERLY
FLOW LASTING PERHAPS EVEN INTO MONDAY. I HAVE CHANCE POPS
SUNDAY...BUT LESS THAN THAT SUNDAY NIGHT/MONDAY WITH LACK OF
CERTAINTY...AND WITH DRIER ATMOSPHERE AS WELL AS RISING HEIGHTS
HEADING INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
WE CONTINUE TO FORECAST IFR CONDITIONS TO DEVELOP EARLY THIS
MORNING AT ELM, AND POSSIBLY BGM. THESE SITES LOOK MOST PRONE TO
FOG BASED ON POSITION OF WARM FRONT, RECENT HISTORY, AND CURRENT
T/TD SPREADS. TEMPO MVFR CONDITIONS ARE FORECAST AT THE RME AND
ITH TERMINALS.
A COLD FRONT WILL BRING THUNDERSTORMS INTO NY/PA THIS AFTERNOON.
THE BEST CHANCE FOR THUNDERSTORMS WILL BE BETWEEN 18Z AND 24Z.
HEAVY DOWNPOURS AND SMALL HAIL ARE POSSIBLE, WITH MVFR
RESTRICTIONS IN THUNDERSTORMS EXPECTED.
.OUTLOOK...
WEDNESDAY TO THURSDAY NIGHT...MAINLY VFR.
FRIDAY AND SATURDAY...MVFR IN OCCASIONAL SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BMW/MDP
NEAR TERM...BMW/HEDEN
SHORT TERM...MDP
LONG TERM...MDP
AVIATION...DJP
CLIMATE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 PM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL WILL TRACK TO THE NORTHEAST OVER THE
COASTAL CAROLINAS TONIGHT THROUGH WEDNESDAY. BERYL WILL THEN MOVE
NORTHEAST AWAY FROM THE COAST LATE WEDNESDAY THROUGH WEDNESDAY
NIGHT. A STORM SYSTEM WILL APPROACH FROM THE WEST LATE THURSDAY
NIGHT AND MOVE THROUGH THE AREA FRIDAY THROUGH FRIDAY NIGHT. WEAK
HIGH PRESSURE WILL BUILD OVER THE AREA SATURDAY THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 PM TUESDAY...
OVERVIEW: CENTRAL NC WEATHER WILL BE LARGELY DRIVEN BY THE EFFECTS
OF T.D. BERYL AND ITS PRECEDING INFLUX OF TROPICAL MOISTURE. THE
CENTER OF BERYL... NOW LOCATED OVER SE GA... IS EXPECTED TO CONTINUE
A MOVEMENT TO THE NE ALONG COASTAL SECTIONS OF SC TONIGHT INTO MID
MORNING WEDNESDAY... BEFORE SCRAPING ALONG THE SRN COAST OF NC
WEDNESDAY AFTERNOON INTO THE EVENING... AND MOVING AWAY FROM THE
COAST WEDNESDAY NIGHT. (PLEASE SEE THE LATEST BULLETINS FROM THE NHC
CONCERNING THE SPECIFICS OF BERYL). HEAVY RAIN REMAINS A SIGNIFICANT
THREAT MAINLY IN AREAS ALONG AND EAST OF A LINE FROM LAURINBURG TO
DUNN TO TARBORO. FLASH FLOOD WATCH WILL BE CONTINUED FOR THIS AREA.
REST OF TODAY INTO TONIGHT: SCATTERED SHOWERS AND ISOLATED STORMS
ARE ONGOING WITH THE GREATEST COVERAGE OVER THE COASTAL PLAIN...
ALONG THE INLAND-MOVING SEA BREEZE AND COINCIDENT WITH THE BETTER
INSTABILITY (MLCAPE NEAR 1500 J/KG). AS MENTIONED THIS MORNING...
THE HRRR MODEL IS HANDLING THIS TROPICAL CONVECTION PRETTY WELL... A
COUPLE OF HOURS TOO SLOW BUT OVERALL AN ACCURATE DEPICTION OF
COVERAGE AND MODE OF CONVECTION. LOCALLY HEAVY RAIN REMAINS A THREAT
THIS AFTERNOON ESPECIALLY IN THE EASTERN FORECAST AREA WHERE THE
LCL-TO-FREEZING-LEVEL DEPTH IS NEAR 4 KM... FAVORING WARM RAIN
PROCESSES... AND WINDS MAY LOCALLY GUST TO 25 MPH NEAR SHOWERS. THE
HRRR SHOWS THIS ACTIVITY DECREASING WITH LOSS OF HEATING BY EARLY
EVENING... VERY REASONABLE CONSIDERING THE LACK OF OTHER FORCING
MECHANISMS AND THE ABSENCE OF DEEP LAYER SHEAR. WILL TREND POPS
DOWN... FROM 30% (NORTH CENTRAL) TO 60% (SOUTHEAST) COVERAGE OVER
THE NEXT FEW HOURS DOWN TO ISOLATED TO SCATTERED UNTIL MID EVENING.
THEN... ATTENTION TURNS NOT ONLY TO THE APPROACH OF BERYL`S RAIN
SHIELD FROM THE SOUTH BUT ALSO TO THE ORGANIZED LINE OF PREFRONTAL
SHOWERS/STORMS NOW RUNNING FROM CENTRAL PA ACROSS WV INTO ERN KY/TN.
THE HRRR HAS CONSISTENTLY SHOWN THIS HOLDING TOGETHER AS IT CROSSES
THE MOUNTAINS/FOOTHILLS INTO THE NW PIEDMONT THROUGH MID TO LATE
EVENING... SUPPORTED BY THE LATEST WRF-NMM AND WRF-ARW. WILL RAMP
POPS BACK UP TO GOOD CHANCE IN THE NW CWA BY LATE EVENING. AS THIS
BAND OF SHOWERS AND STORMS SPREADS EASTWARD THROUGH THE PIEDMONT
AFTER MIDNIGHT... WE EXPECT THE RAIN SHIELD DIRECTLY ASSOCIATED WITH
BERYL TO SPREAD NORTHWARD INTO THE SOUTHERN PORTION OF THE FORECAST
AREA THEN NNE... CULMINATING IN WHAT SHOULD BE WIDESPREAD RAIN AND A
FEW STORMS ESPECIALLY ALONG AND EAST OF HIGHWAY 1 OVERNIGHT. AS WE
HEAD TOWARD DAWN WEDNESDAY... EARLY PARTS OF THE MORNING COMMUTE
COULD BE A RAINLY MESS FROM THE TRIANGLE AREA TO THE SOUTH AND EAST.
LOWS TONIGHT 66-71. -GIH
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM TUESDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: WIDESPREAD MODERATE TO HEAVY RAIN AND
A FEW STORMS ARE EXPECTED TO CONTINUE ALONG AND EAST OF HIGHWAY 1
THROUGH MIDDAY WEDNESDAY. BASED ON THE ANTICIPATED TRACK OF BERYL...
ALONG-TRACK DIRECTED DEEP LAYER SHEAR... AND A FOCUS OF THE
ANOMALOUSLY HIGH PW AND 850 MB THETA-E ALONG COASTAL NC... THE
GREATEST RAINFALL SHOULD OCCUR ALONG COASTAL SC/NC... JUST SE OF THE
FORECAST AREA. BUT MODELS AGREE ON ENOUGH STRONG LOW LEVEL MOISTURE
TRANSPORT NORTH OF THE CENTER COINCIDENT WITH AN UPPER DIVERGENCE
MAXIMUM AND ABUNDANT DEEP MOISTURE IN PLACE TO SUPPORT WIDESPREAD
RAINFALL AMOUNTS OF 1.5-3.0 INCHES ALONG AND EAST OF HIGHWAY 1
THROUGH EARLY WEDNESDAY AFTERNOON. FLASH FLOOD GUIDANCE IN THE WATCH
AREA SHOWS THAT MUCH OF THE WATCH AREA CAN WITHSTAND AROUND 2 INCHES
OF RAIN IN AN HOUR OR SO WITHOUT MAJOR FLOODING PROBLEMS... HOWEVER
SOME URBAN LOCATIONS... INCLUDING FAYETTEVILLE / CLINTON / GOLDSBORO
/ WILSON / SMITHFIELD... MAY ONLY BE ABLE TO TAKE A QUICK INCH OR
SO BEFORE STREAMS AND DITCHES FILL UP AND STREETS BEGIN TO FLOOD.
WILL LEAVE THE WATCH IN PLACE. FOLLOWING NHC GUIDANCE FOR BERYL AND
THE CONSENSUS OF MODEL OUTPUT REGARDING RAINFALL AND TIMING... WE
SHOULD SEE RAIN TAPERING OFF WEST TO EAST FROM MID AFTERNOON THROUGH
EARLY WEDNESDAY EVENING... WITH GRADUAL CLEARING TAKING PLACE IN ITS
WAKE AS LOW LEVEL FLOW BECOMES NORTHWESTERLY AND POST-STORM DRY AIR
FILTERS IN. HIGHS OF 78-86 AND LOWS 61-65. -GIH
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THURSDAY AND THURSDAY NIGHT...THE GFS MOISTENS THE AIR MASS MUCH
MORE QUICKLY THAN THE NAM...WITH PRECIPITABLE WATER VALUES ON THAT
MODEL RISING TO 1.5 INCHES BY 00Z FRIDAY COMPARED WITH 1.25 INCHES
AND THAT ONLY OVER THE SOUTHWEST PIEDMONT BY THE SAME TIME. NAM BUFR
SOUNDINGS ARE MUCH MORE STABLE AS WOULD BE EXPECTED...WHILE GFS BUFR
SOUNDINGS ARE NOT ALL THAT UNSTABLE...WITH MODEST CIN PARTICULARLY
IN THE BOUNDARY LAYER. GIVEN THE WEAK SHEAR IN PLACE THURSDAY...LESS
THAN 20KT AT 0-3KM...THE BEST CHANCES FOR ANY SHOWERS THURSDAY
AFTERNOON INTO THURSDAY NIGHT MAY BE SOUTH OF A LINE FROM ABOUT THE
TRIAD TO FAYETTEVILLE...IN VICINITY OF THE BEST 850MB THETA-E
ADVECTION AND CLOSER TO THE APPROACHING SURFACE AND 850MB BOUNDARY
THAT SHOULD MOVE INTO CENTRAL NORTH CAROLINA LATE IN THE DAY AND
OVERNIGHT. SLIGHT CHANCE OR CHANCE POPS WERE IN THE FORECAST
ALREADY...AND GIVEN THE UNCERTAINTY IN THE MOISTURE ADVECTION WILL
NOT REMOVE ANY OF THESE...BUT FOR THIS FORECAST WILL LEAN TOWARD
CHANCE POPS BEING THURSDAY NIGHT AND AWAY FROM THE NORTHERN COASTAL
PLAIN...WHERE THE COMBINATION OF LIFT AND MOISTURE IS LEAST THROUGH
12Z FRIDAY. HIGHS THURSDAY IN THE MID 80S TO NEAR 90. OVERNIGHT LOWS
SOLIDLY IN THE 60S.
FRIDAY...UPPER DIFFLUENCE INCREASES ON BOTH THE NAM AND THE GFS...
ALONG WITH AVAILABLE INSTABILITY. LIFTED INDICES ON THE GFS FALL TO
NEAR -7C FRIDAY AFTERNOON...AND WHILE THE NAM IS LESS...IT STILL
FORECASTS A RESPECTABLE -3C TO -5C WITH BOTH MODELS INDICATING
NEARLY 1500J/KG OF SURFACE-BASED CAPE AS 0-6KM SHEAR INCREASES TO
AROUND 30KT...SLIGHTLY HIGHER BY 00Z SATURDAY TOWARD THE YADKIN
RIVER. AS THE SURFACE COLD FRONT SLOWLY APPROACHES FROM THE WEST...
ENOUGH LIFT SHOULD OVERCOME THE CIN AVAILABLE ON GFS BUFR SOUNDINGS
TO GENERATE AT LEAST SCATTERED THUNDERSTORMS...LIKELY BECOMING
NUMEROUS TOWARD THE YADKIN RIVER LATER IN THE DAY. THE INCREASING
LOW-LEVEL WIND FLOW SHOULD SUPPORT THE POTENTIAL FOR SEVERE WEATHER
MAINLY IN THE FORM OF WIND...HOWEVER...WILL NOTE THAT 0-3KM HELICITY
ON BOTH THE NAM AND GFS IS AROUND 125M2/S2...AND THE LOW-LEVEL WIND
FIELD ON THE GFS SHOWS GREATER TURNING AS COMPARED TO THE NAM. HIGHS
FRIDAY WILL BE MOSTLY IN THE 80S.
BEYOND FRIDAY...TIMING DIFFERENCES BETWEEN THE GFS AND THE ECMWF
REMAIN DIFFICULT TO RESOLVE...PARTICULARLY AS BOTH SETS OF GUIDANCE
ARE VERY CONSISTENT WITH THEMSELVES. THE DGEX LEANS MORE TOWARD THE
FASTER ECWMF...BUT THAT MODEL HAS TRENDED EVER SO SLIGHTLY SLOWER...
PARTICULARLY WITH THE SPEED OF THE SURFACE FRONT AND LIKELY DUE TO
ITS TREND HIGHER WITH MID- AND UPPER-LEVEL HEIGHTS FROM SOUTHEAST
CANADA OFFSHORE OF CONUS IN THE ATLANTIC. THIS WOULD SUGGEST THE GFS
MAY ACTUALLY VERIFY BETTER...BUT CONCERNS REGARDING CONVECTIVE
FEEDBACK IN THAT MODEL CONTINUE.
HAVE KEPT THE PREVIOUS FORECAST ESSENTIALLY INTACT...THOUGH FEEL
THERE IS ENOUGH CONFIDENCE THIS FORECAST TO MENTION LIKELY CHANCES
FOR SHOWERS AND THUNDERSTORMS OVER MOST OF CENTRAL NORTH CAROLINA
FRIDAY NIGHT TRANSITIONING FROM FRIDAY...IN ADVANCE OF THE FRONT AND
IN AN ATMOSPHERE WITH HIGH MOISTURE...AS PRECIPITABLE WATER VALUES
SHOULD EASILY EXCEED 1.5 INCHES AND LIKELY APPROACH 1.75 INCHES.
DEPENDING ON THE TIMING OF THE FRONT...IF THE GFS VERIFIES EXACTLY
SOME SEVERE WEATHER POTENTIAL WOULD EXIST EVEN LATE SATURDAY MAINLY
INTERSTATE 95 AND EAST...BUT FOR NOW WILL NOT MENTION THIS
POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK...WHILE IN DEFERENCE TO
THE GFS FORECASTING A SLIGHT CHANCE OF SHOWERS THROUGHOUT CENTRAL
NORTH CAROLINA SATURDAY MORNING AND A SLIGHT CHANCE OF THUNDERSTORMS
MAINLY FROM U.S. 1 AND EAST SATURDAY AFTERNOON. IT SHOULD BE NOTED
THAT THE GFS HAS TRENDED SLIGHTLY DRIER SATURDAY...PARTICULARLY
SATURDAY AFTERNOON...FROM ITS 06Z TUESDAY RUN TO THE 12Z TUESDAY RUN.
THE FORECAST WILL REMAIN DRY SATURDAY NIGHT THROUGH MONDAY...AS
DRIER AIR MOVES INTO CENTRAL NORTH CAROLINA AND HIGH PRESSURE BUILDS
IN. UPPER-LEVEL LOW PRESSURE OVER THE FAR NORTHEAST STATES AND THE
CANADIAN MARITIMES...ALONG WITH HIGH AMPLITUDE RIDGING OVER THE
CENTER OF THE NATION...WILL KEEP CENTRAL NORTH CAROLINA IN NORTHWEST
FLOW ALOFT FROM SUNDAY THROUGH THE EARLY PART OF THE NEXT WORK WEEK.
BOTH THE ECMWF AND THE GFS SUGGEST A SERIES OF MID-LEVEL SHORTWAVES
MOVING OVER OR JUST NORTH OF CENTRAL NORTH CAROLINA MONDAY AND AGAIN
ON TUESDAY...AND NEAR WHAT LIKELY WILL BE A FRONTAL BOUNDARY FROM
THE CENTRAL PLAINS AND MID-MISSISSIPPI VALLEY INTO THE OHIO VALLEY...
THUNDERSTORMS SHOULD DEVELOP AT TIMES AND MOVE EAST-SOUTHEAST OR
SOUTHEAST ON THE PREVAILING FLOW ALOFT AND FOLLOWING THE THERMAL
WIND AS FORECAST SIMILARLY BY BOTH THE GFS AND ECMWF. ALTHOUGH SOME
QPF IS FORECAST PARTICULARLY BY THE 00Z ECMWF FOR MONDAY...WILL KEEP
THAT DAY DRY FOR NOW AS ALL OF THE GFS MOS ENSEMBLES ARE BELOW
CLIMATOLOGY IN TERMS OF CHANCES FOR PRECIPITATION ON MONDAY.
HOWEVER...BY TUESDAY...THE FRONT MAY SAG SOUTH JUST ENOUGH TO ALLOW
FOR A BETTER POTENTIAL FOR A FEW SHOWERS OR THUNDERSTORMS TO REACH
CENTRAL NORTH CAROLINA FROM THE NORTHWEST. DID NOT FORECAST HIGHS AS
WARM AS THE GFS THICKNESSES WOULD IMPLY...STICKING CLOSER TO HIGHS
AS SUGGESTED BY THE 1000-850MB THICKNESSES OF THE ECMWF CONSIDERING
ANY POTENTIAL FOR DEBRIS CLOUDINESS. DESPITE THIS...WARMEST HIGHS
SHOULD BE IN THE SOUTHWEST PIEDMONT...WHERE MID 90S ARE MOST
PROBABLE BY TUESDAY. AS THE AIR MOISTENS ONCE AGAIN...OVERNIGHT LOWS
MOSTLY IN THE 50S SATURDAY NIGHT WILL RISE TO NEAR 70 OR SLIGHTLY
WARMER BY TUESDAY NIGHT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 155 PM TUESDAY...
THIS AFTERNOON`S PRIMARILY VFR CONDITIONS OVER CENTRAL NC TERMINAL
FORECAST SITES WILL DETERIORATE TO MVFR (AND BRIEFLY IFR) FROM SOUTH
TO NORTH STARTING LATE TONIGHT. T.D. BERYL IS EXPECTED TO MOVE FROM
SE GA OVER COASTAL SECTIONS OF SC TONIGHT THEN ALONG THE SRN NC
COAST ON WEDNESDAY (SEE NHC BULLETINS FOR THE LATEST INFO).
CURRENTLY... PATCHY SHOWERS WERE NOTED AROUND THE TRIAD REGION BUT
ARE UNLIKELY TO DOMINATE AT INT/GSO THROUGH TONIGHT. FARTHER EAST...
MORE NUMEROUS SHOWERS AND A FEW STORMS WILL BRING A SHORT PERIOD OF
IFR CONDITIONS AT RWI/FAY AND MAY AFFECT RDU AS WELL THROUGH 22Z.
THEN AFTER NIGHTFALL... LOSS OF HEATING WILL LEAD TO DIMINISHING
SHOWERS... BUT BERYL`S APPROACH FROM THE SOUTH IS EXPECTED TO BRING
WIDESPREAD HEAVY SHOWERS AND A FEW ISOLATED STORMS TO
CENTRAL/EASTERN SITES MAINLY AFTER MIDNIGHT... STARTING FIRST AT FAY
AFTER 06Z AND THEN AT RDU/RWI AFTER 08Z. MVFR TO IFR CIGS/VSBYS ARE
LIKELY AT FAY/RWI/RDU. INT/GSO SHOULD SEE A ROUND OF MVFR SHOWERS
THIS EVENING BUT THE MOST WIDESPREAD RAIN SHOULD HOLD EAST OF THIS
AREA. THE GREATEST RISK OF ADVERSE AVIATION CONDITIONS WILL OCCUR
08Z-15Z AT FAY... 09Z-16Z AT RDU... AND 10Z-18Z AT RWI. FAY IS MOST
LIKELY TO SEE WINDS SUSTAINED FROM THE NE AT 12-15 KTS GUSTING TO
20-25 KTS STARTING LATE TONIGHT. NE WINDS WILL BE A BIT LIGHTER AT
RDU/RWI.
LOOKING BEYOND 18Z WEDNESDAY... HIGH CONFIDENCE IN RETURNING VFR
CONDITIONS WEST TO EAST WEDNESDAY AFTERNOON THROUGH EARLY EVENING AS
BERYL MOVES AWAY. VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THURSDAY
NIGHT... ALTHOUGH SHALLOW GROUND FOG IS POSSIBLE TOWARD DAWN
FRIDAY... AND BORDERLINE LOW LEVEL WIND SHEAR MAY BE SEEN AS WELL AS
WINDS JUST OFF THE GROUND INCREASE OUT OF THE SOUTHWEST. AN
APPROACHING STORM SYSTEM WILL BRING A CHANCE OF MVFR CONDITIONS WITH
SHOWERS AND STORMS STARTING EARLY AFTERNOON FRIDAY THROUGH FRIDAY
NIGHT. VFR CONDITIONS ARE EXPECTED TO RETURN BEHIND THIS SYSTEM
SATURDAY AFTERNOON THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON FOR
NCZ028-042-043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...DJF
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
158 PM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL WILL MOVE SLOWLY TO THE NORTHEAST OVER
SOUTHEAST GEORGIA TODAY... THEN TRACK ALONG THE CAROLINA COAST
TONIGHT AND WEDNESDAY. A STORM SYSTEM WILL APPROACH FROM THE WEST
THURSDAY NIGHT AND MOVE THROUGH THE AREA FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1005 AM TUESDAY...
THROUGH THE REST OF THE AFTERNOON: TOUGH CALL ON THE COVERAGE OF
SHOWERS AND ISOLATED STORM ACTIVITY TODAY. THE CENTER OF T.D. BERYL
REMAINED OVER SE GEORGIA THIS MORNING... AND THE NHC EXPECTS A SLOW
AND STEADY NORTHEASTWARD MOVEMENT TODAY TO NEAR CHS SHORTLY AFTER
MIDNIGHT. ISOLATED SHOWERS HAVE ALREADY BLOSSOMED OVER THE SOUTHERN
PORTIONS OF CENTRAL NC WITH BETTER COVERAGE NEAR THE INLAND-MOVING
SEA BREEZE IN COASTAL SECTIONS. WHILE THESE SHOWERS ARE NOT DIRECTLY
A PRODUCT OF BERYL... 12Z UPPER AIR ANALYSES SHOWED A VERY MOIST
ATLANTIC-SOURCE LOW LEVEL INFLOW INTO CENTRAL NC WITH ABUNDANT
POSITIVE ADVECTION OF WELL-ABOVE-NORMAL PRECIPITABLE WATER (140% TO
NEARLY 200% OF NORMAL ACCORDING TO MORNING SOUNDINGS AND BLENDED TPW
IMAGERY). THE LATEST HRRR MODEL OUTPUT IS HANDLING THE ONGOING
PRECIP ACROSS THE REGION QUITE WELL... ALTHOUGH IT IS A COUPLE OF
HOURS SLOW WITH THIS INITIAL SHOWER DEVELOPMENT. FOLLOWING ITS
GENERAL THEME HOWEVER SUPPORTS TRENDING UP TO SCATTERED COVERAGE IN
THE SOUTHEAST CWA (WHERE PW IS HIGHEST) AND ISOLATED ELSEWHERE BY
EARLY AFTERNOON. THE PICTURE GETS A BIT MORE MURKY AFTER THIS TIME.
YESTERDAY`S SHOWERS/STORMS PEAKED IN COVERAGE AND INTENSITY BY MID
AFTERNOON... THEN QUICKLY FELL OFF AS THE WEAKLY SHEARED ENVIRONMENT
AND CONVECTIVE DEBRIS CLOUDS LIMITED INSTABILITY AND SUPPRESSED
FURTHER DEVELOPMENT. WHILE THE SHEAR REMAINS MEAGER... TODAY`S
ENVIRONMENT IS WETTER AND THE MID LEVEL LAPSE RATES ARE A BIT HIGHER
THAN YESTERDAY YIELDING INSTABILITY APPROACHING MODERATE VALUES
(SKINNY 750-1000 J/KG OF MLCAPE AS OF 10 AM)... AND STRATUS THIS
MORNING WAS A LITTLE LESS WIDESPREAD THAN YESTERDAY. HAVE HELD ONTO
A PERIOD OF LIKELY POPS IN THE COASTAL PLAIN BUT HAVE BACKED UP
TIMING TO BETTER FOLLOW HRRR TRENDS. LOCALLY HEAVY RAIN REMAINS A
THREAT TODAY ESPECIALLY IN THE EASTERN FORECAST AREA WHERE THE
LCL-TO-FREEZING-LEVEL DEPTH IS NEAR 4 KM... FAVORING WARM RAIN
PROCESSES. WINDS MAY GUST TO 25 MPH NEAR SHOWERS. HIGHS IN THE
MID-UPPER 80S STILL APPEAR REASONABLE. -GIH
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 317 AM TUESDAY...
TONIGHT INTO WEDNESDAY...PRESENCE OF MID LEVEL TROUGH WILL LIKELY
AID TO SUSTAIN A FEW SHOWERS AND ISOLATED T-STORMS IN THE NW
PIEDMONT THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS. HOWEVER
WITH LOSS OF HEATING AND RESULTANT STABILIZING BOUNDARY
LAYER...EXPECT CONVECTION TO SLOWLY WANE IN COVERAGE AND INTENSITY
AFTER 11 PM. TO OUR SE...THE REMNANT CIRCULATION OF BERYL WILL DRIFT
NE ALONG THE GA/SC COAST. THE APPROACH OF THIS SYSTEM IN TANDEM WITH
INCREASING DIVERGENCE ALOFT ASSOCIATED WITH AN UPPER JET LIFTING
ACROSS THE UPPER OH VALLEY-SOUTHERN NEW ENGLAND...AND THE MID LEVEL
TROUGH OVER THE PIEDMONT WILL INCREASE LIFT THROUGH A LARGE PART OF
THE ATMOSPHERE OVER EASTERN NC. WITH PRECIP WATER VALUES AT OR ABOVE
2 INCHES...SHOWERS WILL BE EFFICIENT RAIN PRODUCERS AND COULD SEE
RAINFALL RATES BY EARLY WEDNESDAY OF 1-1.5 INCHES PER HOUR OVER THE
SOUTHERN COASTAL PLAIN. THIS PERIOD OF MODERATE TO HEAVY RAIN WILL
EXTEND INTO THE CENTRAL COASTAL PLAIN DURING THE MORNING HOURS. MAY
SEE RAIN TOTALS 2-4 INCHES ALONG AND EAST OF A
FAYETTEVILLE-SMITHFIELD-TARBORO LINE BY EARLY AFTERNOON WEDNESDAY
WITH THE BULK OF THAT RAIN FALLING IN 4 HOURS OR LESS.
DURING THE AFTERNOON...THE MID LEVEL TROUGH WILL PUSH EWD AND SHUNT
THE DEEPER MOISTURE AND BETTER LIFT TOWARD THE COAST. THUS SHOULD
SEE SHOWER COVERAGE AND INTENSITY DIMINISH DURING THE COURSE OF THE
AFTERNOON. MAX TEMPS AGAIN DEPENDENT UPON EXTENT OF SHOWER COVERAGE.
EXPECT THE COOLER MAX TEMPS IN THE FAR EAST WHERE SHOWERS WILL BE
PREVALENT MOST OF THE DAY WHILE THE WARMER MAX TEMPS WILL LIKELY BE
FOUND IN THE WEST WHERE DRIER AIR BEHIND THE EXITING MID LEVEL
TROUGH MAY ALLOW FOR PARTIAL SUN AND ALLOW TEMPS TO REBOUND. MAX
TEMPS MID 80S WEST TO AROUND 80 FAR EAST.
IMPROVING WEATHER CONDITIONS WEDNESDAY NIGHT AS SUBSIDENCE BEHIND
THE EXITING MID LEVEL TROUGH AND THE REMNANT CIRCULATION OF BERYL
SHOULD DISSIPATE CLOUD COVERAGE. WHILE SKIES MAY CLEAR
ALOFT...RESIDUAL BOUNDARY LAYER MOISTURE WILL REMAIN PLENTIFUL. THIS
MAY LEAD TO THE DEVELOPMENT OF FOG BY EARLY THU AM...ESPECIALLY
ALONG AND EAST OF HIGHWAY 1. MIN TEMPS LOW-MID 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 320 AM TUESDAY...
THURSDAY AND THURSDAY NIGHT:
BRIEF S/W RIDGING ALOFT WILL MOVE ACROSS CENTRAL NC ON THURSDAY IN
THE WAKE OF BERYL... WHILE A RATHER POTENT SYSTEM AMPLIFIES ACROSS
THE CENTRAL PART OF THE COUNTRY. BOTH THE GFS AND NAM SHOW A WEAK
BACKDOOR COLD FRONT POSSIBLE DROPPING SOUTHWARD INTO THE REGION ON
THURSDAY... BEFORE LIFTING BACK NORTHWARD AS A WARM FRONT ON
THURSDAY NIGHT. THIS BOUNDARY INTERACTING (IF IT DROPS INTO OUR
AREA) WITH STILL A RATHER MOIST LOW LEVEL AIRMASS CHARACTERIZED BY
DEWPOINTS IN THE 60S WILL ALLOW FOR THE POTENTIAL OF SOME ISOLATED
TO SCATTERED SHOWERS AND STORMS... WITH HIGHEST PROBABILITIES OF
SHOWERS/STORMS ACROSS THE NORTH/NORTHWEST FROM THURSDAY AFTERNOON
INTO THE EVENING/EARLY OVERNIGHT HOURS OF FRIDAY. HAVE RAISED HIGHS
BY A COUPLE OF DEGREES GIVEN AFTERNOON LOW LEVEL THICKNESS VALUES
ARE EXPECTED TO TOP OUT IN THE 1405 TO 1420 METER RANGE. THIS YIELDS
HIGHS RANGING FROM THE LOWER 90S S/SW TO THE UPPER 80S NE. GIVEN THE
BACKDOOR COLD FRONT IS EXPECTED TO STALL/THEN SHIFT BACK AS A WARM
FRONT THURSDAY NIGHT... WILL GO WITH LOWS RANGING FROM THE MID TO
UPPER 60S... COOLEST ACROSS THE NE.
FRIDAY THROUGH MONDAY:
A POTENT UPPER LOW AND ASSOCIATED PRIMARY SURFACE LOW ARE EXPECTED
TO LIFT NNE`WARD FROM THE MIDWEST IN THE GREAT LAKES REGION ON
FRIDAY INTO SATURDAY. MODELS CONTINUE TO DIFFER ON THE AMPLIFICATION
OF THE UPPER LEVEL TROUGH. HOWEVER... STILL EXPECT INCREASING
CHANCES FOR SHOWERS AND STORMS ON FRIDAY INTO FRIDAY NIGHT...
POSSIBLY LINGERING INTO SATURDAY ACROSS OUR FAR EAST... AS AN
ASSOCIATED SURFACE COLD FRONT CROSSES THE AREA. THE GFS CONTINUES TO
BE SLOWER AND FURTHER SOUTH WITH ITS PLACEMENT OF THE UPEPR LOW...
WHICH YIELDS A GOOD 6-12 HOUR SLOWER FROPA THAN THE ECMWF.
HOWEVER... GIVEN THE INCREASING LARGE SCALE LIFT FROM THE
UNSEASONABLY STRONG TROUGH ALOFT WILL RAISE POPS A BIT ON FRIDAY
AFTERNOON INTO THE EVENING. THIS YIELDS LIKELY POPS NW TO CHANCE
ELSEWHERE. GIVEN THE TIMING DIFFERENCES AMONG THE MEDIUM RANGE
MODELS STILL NOT SURE WHEN THE HIGHEST THREAT OF STRONG TO SEVERE
STORMS WILL BE. HOWEVER... GIVEN THE IMPRESSIVE 40-45 KTS OF DEEP
LAYER SHEAR WITH AT LEAST SOME SURFACE INSTABILITY (RANGES GIVEN
DIFFERENCES OF FRONTAL TIMING) EXPECT WE WILL SEE SOME ORGANIZED
CONVECTION... WITH SOME SEVERE STORMS POSSIBLE. HOWEVER... WILL SKEW
THE FORECAST CLOSER TO THE LATEST ECMWF... WHICH IS PREFERRED BY HPC
AND HAS DECENT RUN TO RUN CONSISTENCY AT LEAST FOR THE FRIDAY/FRIDAY
SYSTEM. THE LATEST ECWMF BRINGS THE FRONT THROUGH THE AREA LATE
FRIDAY INTO FRIDAY NIGHT. THUS... WILL ACCORDINGLY SHOW POPS
LOWERING TO SLIGHT CHANCE AREAWIDE BY DAYBREAK SATURDAY... WITH NO
MENTION OF SHOWERS AND STORMS BY SATURDAY AFTERNOON.
HIGH TEMPS ON FRIDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S...
GIVEN THE EXPECTED SHOWERS AND STORMS/CLOUD COVER. LOWS SATURDAY
MORNING IN THE LOWER 60S NW TO MID TO UPPER 60S SE. EXPECT HIGHS
SATURDAY WILL BE IN THE UPPER 70S NW/N TO LOWER 80S ELSEWHERE.
EXPECT GENERALLY DRY CONDITIONS FOR SATURDAY NIGHT THROUGH MONDAY...
AS SURFACE HIGH PRESSURE MOVES ACROSS THE REGION. HOWEVER... WITH
NORTHWEST FLOW ALOFT CANNOT RULE OUT SOME DISTURBANCES TRACKING
ACROSS BY EARLY NEXT WEEK. HIGH TEMPS FOR SUNDAY AND MONDAY ARE
EXPECTED TO BE IN THE 80S... WITH LOWS GENERALLY IN THE LOWER TO MID
60S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 155 PM TUESDAY...
THIS AFTERNOON`S PRIMARILY VFR CONDITIONS OVER CENTRAL NC TERMINAL
FORECAST SITES WILL DETERIORATE TO MVFR (AND BRIEFLY IFR) FROM SOUTH
TO NORTH STARTING LATE TONIGHT. T.D. BERYL IS EXPECTED TO MOVE FROM
SE GA OVER COASTAL SECTIONS OF SC TONIGHT THEN ALONG THE SRN NC
COAST ON WEDNESDAY (SEE NHC BULLETINS FOR THE LATEST INFO).
CURRENTLY... PATCHY SHOWERS WERE NOTED AROUND THE TRIAD REGION BUT
ARE UNLIKELY TO DOMINATE AT INT/GSO THROUGH TONIGHT. FARTHER EAST...
MORE NUMEROUS SHOWERS AND A FEW STORMS WILL BRING A SHORT PERIOD OF
IFR CONDITIONS AT RWI/FAY AND MAY AFFECT RDU AS WELL THROUGH 22Z.
THEN AFTER NIGHTFALL... LOSS OF HEATING WILL LEAD TO DIMINISHING
SHOWERS... BUT BERYL`S APPROACH FROM THE SOUTH IS EXPECTED TO BRING
WIDESPREAD HEAVY SHOWERS AND A FEW ISOLATED STORMS TO
CENTRAL/EASTERN SITES MAINLY AFTER MIDNIGHT... STARTING FIRST AT FAY
AFTER 06Z AND THEN AT RDU/RWI AFTER 08Z. MVFR TO IFR CIGS/VSBYS ARE
LIKELY AT FAY/RWI/RDU. INT/GSO SHOULD SEE A ROUND OF MVFR SHOWERS
THIS EVENING BUT THE MOST WIDESPREAD RAIN SHOULD HOLD EAST OF THIS
AREA. THE GREATEST RISK OF ADVERSE AVIATION CONDITIONS WILL OCCUR
08Z-15Z AT FAY... 09Z-16Z AT RDU... AND 10Z-18Z AT RWI. FAY IS MOST
LIKELY TO SEE WINDS SUSTAINED FROM THE NE AT 12-15 KTS GUSTING TO
20-25 KTS STARTING LATE TONIGHT. NE WINDS WILL BE A BIT LIGHTER AT
RDU/RWI.
LOOKING BEYOND 18Z WEDNESDAY... HIGH CONFIDENCE IN RETURNING VFR
CONDITIONS WEST TO EAST WEDNESDAY AFTERNOON THROUGH EARLY EVENING AS
BERYL MOVES AWAY. VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THURSDAY
NIGHT... ALTHOUGH SHALLOW GROUND FOG IS POSSIBLE TOWARD DAWN
FRIDAY... AND BORDERLINE LOW LEVEL WIND SHEAR MAY BE SEEN AS WELL AS
WINDS JUST OFF THE GROUND INCREASE OUT OF THE SOUTHWEST. AN
APPROACHING STORM SYSTEM WILL BRING A CHANCE OF MVFR CONDITIONS WITH
SHOWERS AND STORMS STARTING EARLY AFTERNOON FRIDAY THROUGH FRIDAY
NIGHT. VFR CONDITIONS ARE EXPECTED TO RETURN BEHIND THIS SYSTEM
SATURDAY AFTERNOON THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON FOR
NCZ028-042-043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1007 AM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL WILL MOVE SLOWLY TO THE NORTHEAST OVER
SOUTHEAST GEORGIA TODAY... THEN TRACK ALONG THE CAROLINA COAST
TONIGHT AND WEDNESDAY. A STORM SYSTEM WILL APPROACH FROM THE WEST
THURSDAY NIGHT AND MOVE THROUGH THE AREA FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1005 AM TUESDAY...
THROUGH THE REST OF THE AFTERNOON: TOUGH CALL ON THE COVERAGE OF
SHOWERS AND ISOLATED STORM ACTIVITY TODAY. THE CENTER OF T.D. BERYL
REMAINED OVER SE GEORGIA THIS MORNING... AND THE NHC EXPECTS A SLOW
AND STEADY NORTHEASTWARD MOVEMENT TODAY TO NEAR CHS SHORTLY AFTER
MIDNIGHT. ISOLATED SHOWERS HAVE ALREADY BLOSSOMED OVER THE SOUTHERN
PORTIONS OF CENTRAL NC WITH BETTER COVERAGE NEAR THE INLAND-MOVING
SEA BREEZE IN COASTAL SECTIONS. WHILE THESE SHOWERS ARE NOT DIRECTLY
A PRODUCT OF BERYL... 12Z UPPER AIR ANALYSES SHOWED A VERY MOIST
ATLANTIC-SOURCE LOW LEVEL INFLOW INTO CENTRAL NC WITH ABUNDANT
POSITIVE ADVECTION OF WELL-ABOVE-NORMAL PRECIPITABLE WATER (140% TO
NEARLY 200% OF NORMAL ACCORDING TO MORNING SOUNDINGS AND BLENDED TPW
IMAGERY). THE LATEST HRRR MODEL OUTPUT IS HANDLING THE ONGOING
PRECIP ACROSS THE REGION QUITE WELL... ALTHOUGH IT IS A COUPLE OF
HOURS SLOW WITH THIS INITIAL SHOWER DEVELOPMENT. FOLLOWING ITS
GENERAL THEME HOWEVER SUPPORTS TRENDING UP TO SCATTERED COVERAGE IN
THE SOUTHEAST CWA (WHERE PW IS HIGHEST) AND ISOLATED ELSEWHERE BY
EARLY AFTERNOON. THE PICTURE GETS A BIT MORE MURKY AFTER THIS TIME.
YESTERDAY`S SHOWERS/STORMS PEAKED IN COVERAGE AND INTENSITY BY MID
AFTERNOON... THEN QUICKLY FELL OFF AS THE WEAKLY SHEARED ENVIRONMENT
AND CONVECTIVE DEBRIS CLOUDS LIMITED INSTABILITY AND SUPPRESSED
FURTHER DEVELOPMENT. WHILE THE SHEAR REMAINS MEAGER... TODAY`S
ENVIRONMENT IS WETTER AND THE MID LEVEL LAPSE RATES ARE A BIT HIGHER
THAN YESTERDAY YIELDING INSTABILITY APPROACHING MODERATE VALUES
(SKINNY 750-1000 J/KG OF MLCAPE AS OF 10 AM)... AND STRATUS THIS
MORNING WAS A LITTLE LESS WIDESPREAD THAN YESTERDAY. HAVE HELD ONTO
A PERIOD OF LIKELY POPS IN THE COASTAL PLAIN BUT HAVE BACKED UP
TIMING TO BETTER FOLLOW HRRR TRENDS. LOCALLY HEAVY RAIN REMAINS A
THREAT TODAY ESPECIALLY IN THE EASTERN FORECAST AREA WHERE THE
LCL-TO-FREEZING-LEVEL DEPTH IS NEAR 4 KM... FAVORING WARM RAIN
PROCESSES. WINDS MAY GUST TO 25 MPH NEAR SHOWERS. HIGHS IN THE
MID-UPPER 80S STILL APPEAR REASONABLE. -GIH
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 317 AM TUESDAY...
TONIGHT INTO WEDNESDAY...PRESENCE OF MID LEVEL TROUGH WILL LIKELY
AID TO SUSTAIN A FEW SHOWERS AND ISOLATED T-STORMS IN THE NW
PIEDMONT THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS. HOWEVER
WITH LOSS OF HEATING AND RESULTANT STABILIZING BOUNDARY
LAYER...EXPECT CONVECTION TO SLOWLY WANE IN COVERAGE AND INTENSITY
AFTER 11 PM. TO OUR SE...THE REMNANT CIRCULATION OF BERYL WILL DRIFT
NE ALONG THE GA/SC COAST. THE APPROACH OF THIS SYSTEM IN TANDEM WITH
INCREASING DIVERGENCE ALOFT ASSOCIATED WITH AN UPPER JET LIFTING
ACROSS THE UPPER OH VALLEY-SOUTHERN NEW ENGLAND...AND THE MID LEVEL
TROUGH OVER THE PIEDMONT WILL INCREASE LIFT THROUGH A LARGE PART OF
THE ATMOSPHERE OVER EASTERN NC. WITH PRECIP WATER VALUES AT OR ABOVE
2 INCHES...SHOWERS WILL BE EFFICIENT RAIN PRODUCERS AND COULD SEE
RAINFALL RATES BY EARLY WEDNESDAY OF 1-1.5 INCHES PER HOUR OVER THE
SOUTHERN COASTAL PLAIN. THIS PERIOD OF MODERATE TO HEAVY RAIN WILL
EXTEND INTO THE CENTRAL COASTAL PLAIN DURING THE MORNING HOURS. MAY
SEE RAIN TOTALS 2-4 INCHES ALONG AND EAST OF A
FAYETTEVILLE-SMITHFIELD-TARBORO LINE BY EARLY AFTERNOON WEDNESDAY
WITH THE BULK OF THAT RAIN FALLING IN 4 HOURS OR LESS.
DURING THE AFTERNOON...THE MID LEVEL TROUGH WILL PUSH EWD AND SHUNT
THE DEEPER MOISTURE AND BETTER LIFT TOWARD THE COAST. THUS SHOULD
SEE SHOWER COVERAGE AND INTENSITY DIMINISH DURING THE COURSE OF THE
AFTERNOON. MAX TEMPS AGAIN DEPENDENT UPON EXTENT OF SHOWER COVERAGE.
EXPECT THE COOLER MAX TEMPS IN THE FAR EAST WHERE SHOWERS WILL BE
PREVALENT MOST OF THE DAY WHILE THE WARMER MAX TEMPS WILL LIKELY BE
FOUND IN THE WEST WHERE DRIER AIR BEHIND THE EXITING MID LEVEL
TROUGH MAY ALLOW FOR PARTIAL SUN AND ALLOW TEMPS TO REBOUND. MAX
TEMPS MID 80S WEST TO AROUND 80 FAR EAST.
IMPROVING WEATHER CONDITIONS WEDNESDAY NIGHT AS SUBSIDENCE BEHIND
THE EXITING MID LEVEL TROUGH AND THE REMNANT CIRCULATION OF BERYL
SHOULD DISSIPATE CLOUD COVERAGE. WHILE SKIES MAY CLEAR
ALOFT...RESIDUAL BOUNDARY LAYER MOISTURE WILL REMAIN PLENTIFUL. THIS
MAY LEAD TO THE DEVELOPMENT OF FOG BY EARLY THU AM...ESPECIALLY
ALONG AND EAST OF HIGHWAY 1. MIN TEMPS LOW-MID 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 320 AM TUESDAY...
THURSDAY AND THURSDAY NIGHT:
BRIEF S/W RIDGING ALOFT WILL MOVE ACROSS CENTRAL NC ON THURSDAY IN
THE WAKE OF BERYL... WHILE A RATHER POTENT SYSTEM AMPLIFIES ACROSS
THE CENTRAL PART OF THE COUNTRY. BOTH THE GFS AND NAM SHOW A WEAK
BACKDOOR COLD FRONT POSSIBLE DROPPING SOUTHWARD INTO THE REGION ON
THURSDAY... BEFORE LIFTING BACK NORTHWARD AS A WARM FRONT ON
THURSDAY NIGHT. THIS BOUNDARY INTERACTING (IF IT DROPS INTO OUR
AREA) WITH STILL A RATHER MOIST LOW LEVEL AIRMASS CHARACTERIZED BY
DEWPOINTS IN THE 60S WILL ALLOW FOR THE POTENTIAL OF SOME ISOLATED
TO SCATTERED SHOWERS AND STORMS... WITH HIGHEST PROBABILITIES OF
SHOWERS/STORMS ACROSS THE NORTH/NORTHWEST FROM THURSDAY AFTERNOON
INTO THE EVENING/EARLY OVERNIGHT HOURS OF FRIDAY. HAVE RAISED HIGHS
BY A COUPLE OF DEGREES GIVEN AFTERNOON LOW LEVEL THICKNESS VALUES
ARE EXPECTED TO TOP OUT IN THE 1405 TO 1420 METER RANGE. THIS YIELDS
HIGHS RANGING FROM THE LOWER 90S S/SW TO THE UPPER 80S NE. GIVEN THE
BACKDOOR COLD FRONT IS EXPECTED TO STALL/THEN SHIFT BACK AS A WARM
FRONT THURSDAY NIGHT... WILL GO WITH LOWS RANGING FROM THE MID TO
UPPER 60S... COOLEST ACROSS THE NE.
FRIDAY THROUGH MONDAY:
A POTENT UPPER LOW AND ASSOCIATED PRIMARY SURFACE LOW ARE EXPECTED
TO LIFT NNE`WARD FROM THE MIDWEST IN THE GREAT LAKES REGION ON
FRIDAY INTO SATURDAY. MODELS CONTINUE TO DIFFER ON THE AMPLIFICATION
OF THE UPPER LEVEL TROUGH. HOWEVER... STILL EXPECT INCREASING
CHANCES FOR SHOWERS AND STORMS ON FRIDAY INTO FRIDAY NIGHT...
POSSIBLY LINGERING INTO SATURDAY ACROSS OUR FAR EAST... AS AN
ASSOCIATED SURFACE COLD FRONT CROSSES THE AREA. THE GFS CONTINUES TO
BE SLOWER AND FURTHER SOUTH WITH ITS PLACEMENT OF THE UPEPR LOW...
WHICH YIELDS A GOOD 6-12 HOUR SLOWER FROPA THAN THE ECMWF.
HOWEVER... GIVEN THE INCREASING LARGE SCALE LIFT FROM THE
UNSEASONABLY STRONG TROUGH ALOFT WILL RAISE POPS A BIT ON FRIDAY
AFTERNOON INTO THE EVENING. THIS YIELDS LIKELY POPS NW TO CHANCE
ELSEWHERE. GIVEN THE TIMING DIFFERENCES AMONG THE MEDIUM RANGE
MODELS STILL NOT SURE WHEN THE HIGHEST THREAT OF STRONG TO SEVERE
STORMS WILL BE. HOWEVER... GIVEN THE IMPRESSIVE 40-45 KTS OF DEEP
LAYER SHEAR WITH AT LEAST SOME SURFACE INSTABILITY (RANGES GIVEN
DIFFERENCES OF FRONTAL TIMING) EXPECT WE WILL SEE SOME ORGANIZED
CONVECTION... WITH SOME SEVERE STORMS POSSIBLE. HOWEVER... WILL SKEW
THE FORECAST CLOSER TO THE LATEST ECMWF... WHICH IS PREFERRED BY HPC
AND HAS DECENT RUN TO RUN CONSISTENCY AT LEAST FOR THE FRIDAY/FRIDAY
SYSTEM. THE LATEST ECWMF BRINGS THE FRONT THROUGH THE AREA LATE
FRIDAY INTO FRIDAY NIGHT. THUS... WILL ACCORDINGLY SHOW POPS
LOWERING TO SLIGHT CHANCE AREAWIDE BY DAYBREAK SATURDAY... WITH NO
MENTION OF SHOWERS AND STORMS BY SATURDAY AFTERNOON.
HIGH TEMPS ON FRIDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S...
GIVEN THE EXPECTED SHOWERS AND STORMS/CLOUD COVER. LOWS SATURDAY
MORNING IN THE LOWER 60S NW TO MID TO UPPER 60S SE. EXPECT HIGHS
SATURDAY WILL BE IN THE UPPER 70S NW/N TO LOWER 80S ELSEWHERE.
EXPECT GENERALLY DRY CONDITIONS FOR SATURDAY NIGHT THROUGH MONDAY...
AS SURFACE HIGH PRESSURE MOVES ACROSS THE REGION. HOWEVER... WITH
NORTHWEST FLOW ALOFT CANNOT RULE OUT SOME DISTURBANCES TRACKING
ACROSS BY EARLY NEXT WEEK. HIGH TEMPS FOR SUNDAY AND MONDAY ARE
EXPECTED TO BE IN THE 80S... WITH LOWS GENERALLY IN THE LOWER TO MID
60S.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
AS OF 603 AM TUESDAY...
LOW END MVFR/IFR CEILINGS WIDESPREAD ACROSS CENTRAL NC
EARLY THIS MORNING AS MOIST SLY FLOW PERSIST ACROSS THE REGION.
SIMILAR TO MONDAY MORNING...EXPECT CEILINGS TO LIFT BETWEEN 12Z-15Z
WITH MOST LOCATIONS SCATTERING INTO A CU FIELD BY LATE MORNING-EARLY
AFTERNOON. A FEW HOURS OF HEATING WILL LEAD TO THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED T-STORMS...MOST LIKELY IN THE
SANDHILLS AND COASTAL PLAIN COUNTIES BY EARLY AFTERNOON. BY LATE
AFTERNOON-EARLY EVENING EXPECT A SECOND AREA OF CONVECTION TO
DEVELOP IN THE NW PIEDMONT...A RESULT OF AN APPROACHING MID LEVEL
TROUGH. SCATTERED SHOWERS AND ISOLATED T-STORMS MAY PLAGUE THE TRIAD
TERMINALS MOST OF THE EVENING INTO THE OVERNIGHT HOURS.
THE APPROACH OF THE REMNANT CIRCULATION OF BERYL MAY BRING A ROUND
OF SHOWERS WITH HEAVY RAIN INTO THE SANDHILLS AND COASTAL PLAIN
PRIOR TO DAYBREAK WEDNESDAY AND PERSIST ALONG AND EAST OF I-95
THROUGH MUCH OF WEDNESDAY MORNING. THIS MAY CAUSE AN EXTENDED PERIOD
OF MVFR/IFR CEILING AND VISIBILITY. AS THE CIRCULATION CENTER
ASSOCIATED WITH BERYL MOVES OFF TO THE NE WEDNESDAY AFTERNOON AND
THE MID LEVEL TROUGH CROSSES THE PIEDMONT...SHOWERS AND T-STORMS
WILL DIMINISH IN COVERAGE AND INTENSITY.
EXPECT IMPROVING AVIATION WEATHER CONDITIONS WED NIGHT INTO THU
THOUGH COULD SEE A PERIOD OF MVFR/IFR FOG EARLY THU MORNING.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST LATE THU.
THIS MAY CAUSE A PERIOD OF MVFR/IFR CEILINGS THU NIGHT ASSOCIATED
WITH A WARM FRONT PASSAGE...AND SUB-VFR CONDITIONS LATE
FRIDAY-FRIDAY NIGHT ASSOCIATED WITH SHOWERS AND T-STORMS EXPECTED
ALONG A COLD FRONT THAT TRAVERSES THE REGION LATE FRIDAY NIGHT.
IMPROVING AVIATION CONDITIONS EXPECTED SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON FOR
NCZ028-042-043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
221 AM EDT TUE MAY 29 2012
.SYNOPSIS...
TROPICAL DEPRESSION BERYL MAY BRING SUBSTANTIAL RAINFALL AND GUSTY
WINDS TO THE AREA WEDNESDAY AS IT MOVES NORTHEAST ALONG THE CAROLINA
COAST. AN UNSEASONABLY STRONG UPPER LEVEL TROUGH AND ITS ASSOCIATED
COLD FRONT MAY IMPACT THE EASTERN CAROLINAS LATE FRIDAY INTO NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1030 PM MONDAY...THIS LATE EVENING UPDATE ADDRESSES CHANGES TO
CLOUD COVERAGE BASED ON LATEST SATELLITE AND ASOS OBSERVATIONS...AND
POP/WX BASED ON RADAR COMPOSITES. THE LATEST HRRR RUN KEEPS OUR
ENTIRE FORECAST AREA DRY OVERNIGHT. TOO MUCH INSTABILITY REMAINS
JUST ABOVE THE SURFACE FOR ME TO FEEL COMFORTABLE WITH A COMPLETELY
DRY FORECAST OVERNIGHT SO SMALL SHOWER/T-STORM CHANCES WILL BE
RETAINED SOUTH OF A LINE FROM FLORENCE...MARION...CONWAY TO
SOUTHPORT OVERNIGHT. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
TD BERYL`S CIRCULATION CENTER REMAINS OVER SOUTH GEORGIA THIS
EVENING...SURROUNDED BY SWIRLING BANDS OF SHOWERS AND THUNDERSTORMS.
AN OUTER BAND PERHAPS PERIPHERALLY LINKED TO THE CYCLONE IS PUSHING
WEST ACROSS THE SOUTH CAROLINA PIEDMONT AND WESTERN COASTAL PLAIN.
NOCTURNAL COOLING OF THE BOUNDARY LAYER SHOULD BRING AN END TO MOST
OF OUR PRECIP CHANCES TONIGHT EXCEPT FOR LINGERING CHANCES ALONG AND
SOUTH OF A LINE FROM FLORENCE TO MYRTLE BEACH. HERE NEW SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM ARE POSSIBLE AT ANY TIME OVERNIGHT
AS CONVECTION PREFERENTIALLY DEVELOPS ACROSS THE GEORGIA AND SOUTH
CAROLINA COASTAL WATERS AND MAY ADVECT INLAND WITH THE CYCLONIC
SOUTH TO SOUTHEAST FLOW. PRECIP CHANCES RANGE FROM 10 PERCENT AT
LUMBERTON...WHITEVILLE AND WILMINGTON...TO 20 PERCENT FROM FLORENCE
TO MARION...AND FINALLY TO 30-40 PERCENT IN THE KINGSTREE-GEORGETOWN
VICINITY.
BERYL IS CONTINUING TO ADVECT A TROPICAL AIRMASS ONSHORE ACROSS AN
INCREASINGLY TROPICAL-LIKE ATLANTIC OCEAN. THIS MEANS WE CAN EXPECT
PLENTY OF MARINE INFLUENCE WITH WELL-ABOVE NORMAL LOW TEMPERATURES
EXPECTED AGAIN TONIGHT. LOWS SHOULD ONLY FALL INTO THE LOWER 70S
WITH SOME UPPER 60S POSSIBLE INLAND. BEACHES WILL DO GOOD TO FALL
INTO THE MID 70S TONIGHT NOW THAT OCEAN WATER TEMPERATURES ARE NEAR
80 IN MANY LOCATIONS. LOW STRATUS CLOUDS ARE ALSO EXPECTED TO
DEVELOP BETWEEN 2-4 AM WITH AREAS MORE THAN 10-20 MILES INLAND FROM
THE COAST POTENTIALLY BECOMING NEARLY OVERCAST LATE TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BERYL WILL BE MOVING UP FROM GEORGIA ON
TUESDAY AND WILL TRACK OVER CAPE FEAR ON WEDNESDAY. IT IS FORECAST
TO REMAIN A DEPRESSION WITH MAX WINDS UP TO 30 MPH MAINLY ON THE
EASTERN SIDE OF THE STORM AS IT MAKES ITS CLOSEST PASS. ALL MODELS
KEEP BERYL ON A NORTHEAST TRACK RUNNING UP THE SOUTHEAST COAST UP
TO HATTERAS AND OUT INTO THE ATLANTIC. THE ECMWF AND CMC ARE RUNNING
THE FARTHEST EAST WHILE THE NAM IS THE SLOWEST WITH THE GFS REMAINING
CLOSEST TO THE COAST. THE GFS HAS BERYL OVER HATTERAS WED NIGHT
WHILE THE NAM HAS IT JUST EAST OF HATTERAS THURS AFTN. AS BERYL
TRACKS UP THE SOUTHEAST COAST...A MID TO UPPER TROUGH WILL DIG
DOWN FROM THE NORTHERN GREAT LAKES PUSHING A COLD FRONT EAST
THROUGH THE CAROLINAS TUES NIGHT INTO WED AND HELP GUIDE BERYL OFF
TO THE NORTHEAST. THIS COLD FRONT WILL INTERACT WITH BERYL TO
PRODUCE A CONSIDERABLE AMOUNT OF PCP ACROSS THE COASTAL CAROLINAS
ON WED. LOOKS LIKE THE GREATEST PCP WILL COME AFTER MIDNIGHT ON
TUES INTO THE FIRST HALF OF WED AS COLD FRONT INTERACTS WITH
BERYL. INITIALLY EXPECT SHOWERS TO PASS ON SHORE ON TUES IN
SOUTHERLY FLOW AHEAD OF BERYL BUT AS BERYL MOVES CLOSER...DEEP
LAYER MOISTURE WILL WORK ITS WAY INTO AREA WITH PCP WATER VALUES
REACHING UP TO 2.25 INCHES IN STRONG S-SE PUSH OF ATLANTIC
MOISTURE. DEWPOINT TEMPS WILL BE AROUND 70 THROUGH WED AFTN. BERYL
WILL ALSO PRODUCE GUSTY WINDS AND COASTAL HAZARDS BUT THE EXTENT
OF THESE WILL DEPEND ON TRACK AND INTENSITY OF BERYL AS IT MOVES
NORTHEAST. DRIER AIR WILL MAKES ITS WAY INTO AREA IN DEEP NW FLOW AS
BERYL EXITS OFF TO THE NORTHEAST WED NIGHT. OVERALL EXPECT
CONSIDERABLE AMOUNT OF CLOUDS ON TUES WITH SHOWERY WEATHER
EXPECTED BUT THE MAIN EFFECTS OF BERYL WILL BE FELT ON WED OVER
THE LOCAL AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...DEEP SOUTHWEST FLOW THU AND FRI WILL INCREASE
THE POTENTIAL FOR DIURNAL CONVECTION ACROSS THE AREA. 5H TROUGH
DIPPING INTO THE MISSISSIPPI VALLEY FRI WILL ENHANCE DIVERGENCE
ALOFT OVER THE SOUTHEASTERN CONUS...INCREASING PRECIP COVERAGE.
SLIGHT CHANCE SEEMS REASONABLE FOR THU GIVEN THE LIMITED DYNAMICS
ALOFT AND MID LEVEL DRY AIR INDICATED BY FORECAST SOUNDINGS. DID
BUMP UP POP A LITTLE FOR FRI...BUT STILL IN THE CHANCE CATEGORY.
KEEPING INHERITED 40 POP FOR FRI NIGHT. STILL A GOOD BIT OF
UNCERTAINTY IN THE FRI/FRI NIGHT FORECAST AS THE ECMWF IS SHOWING
LESS AMPLIFICATION OF THE PATTERN ALOFT WHILE THE LATEST GFS IS MORE
AMPLIFIED AND THUS LITTLE SLOWER. EITHER SOLUTION ENDS UP WITH THE
BULK OF THE MOISTURE AND BEST DYNAMICS PASSING NORTHWEST OF THE
AREA. REGION DRYS OUT OVER THE WEEKEND UNDER DEEP WESTERLY FLOW AS
THE PATTERN ALOFT FLATTENS A LITTLE. WEAK 5H RIDGE STARTING TO BUILD
NORTH FROM THE NORTHERN GULF OF MEXICO LATE IN THE PERIOD.
TEMPERATURES WILL BE ABOVE CLIMO THU THROUGH FRI NIGHT. TIMING OF
THE COLD FRONT WILL HAVE A SIGNIFICANT IMPACT ON TEMPS SAT. AT THIS
POINT THE SLIGHTLY FASTER AND COOLER ECMWF SOLUTION IS FAVORED. IT
APPEARS THE GFS MAY BE SUFFERING FROM SOME FEEDBACK WHICH CAUSES
OVER AMPLIFICATION OF THE TROUGH...SLOWING EVERYTHING DOWN. THE
RESULT IS NEAR TO SLIGHTLY BELOW CLIMO TEMPS OVER THE WEEKEND WITH
TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...THIS TAF VALID PERIOD EXPECT TD BERYL TO MOVE TOWARDS
THE TERMINALS. EXPECT AN INCREASE IN OVERALL CLOUDINESS...AN
INCREASE IN THE COVERAGE AND INTENSITY OF SHOWERS AHEAD OF THE
SYSTEM ESPECIALLY TOMORROW AFTERNOON...AND STEADY RAIN DEVELOPING BY
EVENING AT ALL TERMINALS EXCEPT ILM.
A DEEP SOUTHEASTERLY WIND FLOW WILL MAINTAIN A VERY MOIST AIRMASS
ACROSS THE TERMINALS THIS TAF VALID PERIOD. MAINLY BROKEN MVFR LEVEL
LOW CLOUDS CAN BE EXPECTED WITH ONLY SHORT PERIODS OF VFR. A BRIEF
SHOWER WILL BE POSSIBLE AT THE COASTAL TERMINALS THROUGH SUNRISE.
IFR CEILINGS WILL BE POSSIBLE AT ALL TERMINALS THROUGH
SUNRISE...WITH THE HIGHEST CONFIDENCE AND LOWEST CEILINGS AT THE
FLO/LBT TERMINALS AFTER 08Z. THERE IS LOWER CONFIDENCE OF IFR
ASSOCIATED WITH THE SHOWER ACTIVITY AT THE COASTAL TERMINALS.
ANY IFR CEILINGS SHOULD RISE TO MVFR A COUPLE OF HOURS AFTER
SUNRISE. SCATTERED SHOWERS EXPECTED TERMINAL-WIDE TUESDAY...WITH THE
BEST CHANCE OF SHOWERS MID TO LATE MORNING AT ALL TERMINALS...AND AT
THE SOUTHERN-MOST TERMINALS IN THE LATE AFTERNOON. SOUTHEASTERLY TO
SOUTH SURFACE WINDS EXPECTED...STRONGEST AT THE COASTAL TERMINALS.
WINDS WILL BEGIN TO BACK TO THE EAST SOUTHEAST AS TD BERYL
APPROACHES TOMORROW EVENING.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
THROUGH THE EXTENDED PERIOD...EXCEPT WEDNESDAY WHEN NUMEROUS SHOWERS
AND SCATTERED THUNDERSTORMS ALONG WITH TEMPO IFR CONDITIONS ARE
LIKELY...ESPECIALLY AT THE COASTAL TERMINALS. CHANCE OF IFR MORNING
FOG THURSDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...PREVIOUS FORECAST REMAINS ON TRACK. LATEST
SEA HEIGHT OBSERVATIONS RANGE FROM 6 FT OUT AT THE FRYING PAN SHOALS
BUOY TO 3 FT AT THE NEARSHORE WRIGHTSVILLE BEACH AND SUNSET BEACH
BUOYS...WITH DOMINANT 8 SECOND SWELL. PREVIOUS DISCUSSION FROM 730
PM FOLLOWS...
TROPICAL DEPRESSION BERYL REMAINS INLAND ACROSS SOUTH GEORGIA...BUT
ITS EXPANSIVE WIND FIELD ENCOMPASSES THE CAROLINA COASTAL
WATERS...WHERE SOUTHERLY WINDS 10-15 KT ARE THE DIRECT RESULT OF THE
DEPRESSION. BERYL SHOULD MOVE VERY LITTLE THROUGH TONIGHT AND WE ARE
EXPECTING NEARLY STEADY WINDS THROUGH THE NIGHT AS A RESULT.
SCATTERED SHOWERS AND A FEW THUNDERSTORMS MAY DEVELOP OVER THE
OFFSHORE WATERS TONIGHT AND SHOULD PUSH NORTHWEST...AFFECTING MAINLY
THE WATERS SOUTH OF CAPE FEAR. COVERAGE SHOULD REMAIN AROUND 30
PERCENT EXCEPT PERHAPS A LITTLE HIGHER EAST OF WINYAH BAY AND
GEORGETOWN.
NOW THAT BERYL IS ONSHORE AND OUR WINDS ARE MUCH WEAKER THAN WERE
OBSERVED OVER THE PREVIOUS 2-3 DAYS...SEAS HAVE FINALLY FALLEN BELOW
6 FT IN ALL OF OUR 0-20 MILE COASTAL WATERS FORECAST ZONES. THE LAST
SMALL CRAFT ADVISORY WAS ALLOWED TO EXPIRE AT 6 PM...AND SEAS NO
HIGHER THAN 4-5 FT SHOULD CONTINUE THROUGH THE NIGHT...WITH A GOOD
PORTION OF THAT WAVE ENERGY IN AN 8-9 SECOND SOUTHEAST SWELL.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...EXPECT A SOUTHERLY FLOW MOST OF THE DAY
TUESDAY BETWEEN 10-15 KNOTS AS BERYL MAKES ITS WAY UP FROM GEORGIA
INTO SOUTH CAROLINA. BERYL WILL APPROACH THE AREA LATE TUES MAKING
ITS CLOSEST PASS TO THE LOCAL AREA ON WEDNESDAY. LOCAL WATERS WILL
SEE INCREASING WINDS AND SEAS FROM SOUTH TO NORTH BEGINNING AROUND
MIDNIGHT TUES NIGHT AND INCREASING THROUGH WED MORNING BEFORE
VEERING AROUND THROUGH WED AFTN BECOMING OFF SHORE AS SYSTEM LIFTS
OFF TO THE NORTHEAST BY WED NIGHT. THE INITIAL SOUTHERLY PUSH
AHEAD OF BERYL ON TUES WILL PRODUCE AN INCREASE IN SEAS FROM 2 TO
4 FT TUES MORNING UP TO 3 TO 5 FT BY TUES EVENING. THE GREATEST
INCREASE WILL COME AFTER MIDNIGHT TUES NIGHT WITH SEAS REACHING 6
TO 8 FT WITH INCREASING S-SE WINDS IN OUTER WATERS UP TO 20 TO 25
KTS. BY WED AFTN WINDS SHOULD BEGIN OFF SHORE ALLOWING NEAR SHORE
SEAS TO DIMINISH THROUGH WED NIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...DEVELOPING SOUTH TO SOUTHWEST FLOW ACROSS THE
WATERS THU WILL INCREASE FRI AS GRADIENT TIGHTENS UP AHEAD OF
APPROACHING COLD FRONT. WINDS 10 TO 15 KT WILL INCREASE TO 15 TO 20
KT FRI WHICH COULD...GIVEN THE EXTENDED PERIOD OF SOUTHERLY
FLOW...BUILD SEAS OVER 5 FT LATE FRI. ONCE FRONT CROSSES THE
WATERS...EARLY TO MID MORNING SATURDAY...WEAK OFFSHORE FLOW
DEVELOPS. LACK OF SIGNIFICANT GRADIENT OR COLD ADVECTION WILL KEEP
OFFSHORE FLOW SAT LIGHT...AROUND 10 KT...WITH SEAS DECREASING TO 3
FT OR LESS BY THE END OF THE DAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR
SCZ017-023-024-032-033-039-053>056.
NC...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR
NCZ087-096-099-105>110.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EDT
WEDNESDAY FOR AMZ250-252-254-256.
&&
$$
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
216 PM EDT TUE MAY 29 2012
.SYNOPSIS...
COLD FRONT BRINGS SHOWERS AND POSSIBLE STORMS THIS EVENING. MAINLY
DRY WEDNESDAY. LOW PRESSURE WILL BRING A GOOD CHANCE OF SHOWERS
AND STORMS THURSDAY NIGHT INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...
CONVECTION FURTHER TO THE SOUTHWEST IN WEST CENTRAL KENTUCKY HAS
CUT OFF THE MOISTURE SUPPLY INTO SOUTHERN OHIO...WHICH HAS
ESSENTIALLY KILLED THE SHOWERS AND STORMS BEHIND THE MAIN LINE
THAT IS NOT SOUTH/EAST OF THE OHIO RIVER. THEREFORE...HAVE TRIMMED
BACK SIGNIFICANTLY...BUT NOT ELIMINATED...THE POPS OVER THIS
AREA...WHERE IT APPEARS THE BULK OF THE CONVECTION MAY BE THROUGH
FOR NOW. OTHERWISE...HAVE ACCELERATED THE EASTWARD POPS A BIT FROM
THIS MORNING...AND CUT BACK ON THE END TIMING LATER TONIGHT.
PREVIOUS DISCUSSION...
MOSTLY CLEAR SKIES DURING THE EARLY MORNING HOURS...WILL BECOME
MOSTLY CLOUDY AS CONVECTION ASSOCIATED WITH AN APPROACHING COLD
FRONT SPREADS WEST TO EAST ACROSS THE REGION. SATELLITE IMAGES AND
LIGHTNING DATA INDICATES COLD FRONT OVER IL AROUND 08Z. SOME
CONVECTION IS EVIDENT WELL AHEAD OF THE COLD FRONT OVER INDIANA AT
THE SAME TIME.
ALTHOUGH A TRACKING TOOL BRINGS THE CONVECTION ASSOCIATED WITH
THE FRONT INTO SOUTHEAST OH BY 15Z...BELIEVE THAT CONVECTION WILL
DIE OFF...WHILE ADDITIONAL STORMS REDEVELOP ACROSS KY AND OH...TO
PRODUCE A DELAY ON THE ACTUAL FRONT. MOST MODEL GUIDANCE AGREE
WITH THIS SLOWER SOLUTION WITH THE FRONT...REACHING SOUTHEAST OH
BY 18-21Z...THEN SPREADING SLOWLY EAST ACROSS WV THROUGH 00Z
WEDNESDAY. CODED POPS ACCORDINGLY WITH THIS SLOWER SOLUTION HAVING
CATEGORICAL POPS.
MOST SOUTHEAST OH...AND THE WESTERN HALF OF WV REMAINS IN A SLIGHT
RISK FOR SEVERE STORMS TODAY. SEVERE STORMS ARE EXPECTED TO
DEVELOP UNDER A THERMODYNAMICALLY ENVIRONMENT...WITH HIGH SFC
BASED CAPE EXCEEDING 2500 J/KG OVER BOUNDARY LAYERED CONVERGENCE
PRODUCED BY THE FRONT AND OUTFLOW BOUNDARIES ASSOCIATED WITH
UPSTREAM CONVECTION. BUFKIT SOUNDINGS FROM NAM AND RUC SHOW A
THICK CAPE FEATURE WITH PW AROUND 1.7 INCHES...WITH EQUILIBRIUM
LEVELS REACHING 3500 FEET UNDER WEAK DEEP LAYERED SHEAR. WITH
FREEZING LEVELS AROUND 11000 FEET...VERY STRONG UPDRAFTS COULD
PRODUCE LARGE HAIL...AND DAMAGING DOWNBURSTS.
THE PCPN ACTIVITY SHOULD BE OVER THE EASTERN MOUNTAINS BY
03Z...WHILE THE COLD FRONT DEBILITATES AS IT ENTERS INTO WV.
LOOKING AT BASE PARAMETERS...THERE IS A GOOD INDICATION THAT THE
FRONT LOSES ITS PUNCH AND BECOME DIFFUSE OR NEARLY STATIONARY
ACROSS WV LATE THIS AFTERNOON AND EVENING.
AREAS OF FOG WILL BE COMMON TUESDAY NIGHT INTO WEDNESDAY MORNING
PER ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...ESPECIALLY
OVER AREAS THAT RECEIVE RAIN. LOW LEVEL STRATUS ARE LIKELY TO
PERSIST OVERNIGHT MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS THRU
EARLY WEDNESDAY.
MINOR CHANGES NOTED IN TEMPERATURES THROUGH THE PERIOD.
GENERALLY...EXPECT MID TO UPPER 80S LOWLANDS DUE TO CLOUD COVER
AND PERIODS OF RAIN...TODAY. LOWS WILL REMAIN IN THE 60S DUE TO
HIGH DEWPOINTS TONIGHT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE AREA AT THE BEGINNING
OF THE PERIOD. HOWEVER...AN AREA OF LOW PRESSURE AND AN ASSOCIATED
WARM FRONT WILL APPROACH FROM THE WEST...RESULTING IN A CHANCE OF
STORMS ACROSS THE SOUTH BY THURSDAY NIGHT.
THE LOW WILL THEN MOVE NORTHEAST THROUGH THE REMAINDER OF THE
PERIOD. THE MODELS DIFFER ON THE EXACT MOVEMENT OF THIS SYSTEM...
WITH THE NAM FARTHEST EAST AND THE GFS WELL TO THE WEST OF THE
NAM TRACK.
WILL USE A BLEND OF THE NAM/GFS TRACK AND AS A RESULT...PRECIP CHANCES
SHOULD RAPIDLY INCREASE WITH CATEGORICAL POPS AEXPECTED CROSS MANY
LOCATIONS ON FRIDAY.
FEEL MAIN AREA OF PRECIP WILL PUSH EAST FRIDAY NIGHT AND HAVE
LOWERED POPS ACROSS THE WEST. HOWEVER...GFS WOULD SUGGEST
MEASURABLE RAIN WILL STILL BE POSSIBLE ACROSS OUR WESTERN COUNTIES
INTO FRIDAY NIGHT.
PREVIOUS FORECAST NUMBERS GENERALLY LOOKED GOOD...SO ONLY TWEAKS
MADE BASED ON LATEST GUIDANCE. WITH RAIN EXPECTED ON FRIDAY...WENT
CLOSER TO MET NUMBERS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HAVE GONE WITH HPC THINKING FOR THIS PORTION OF THE FORECAST.
LOW PRESSURE AND ASSOCIATED COLD FRONT WILL PUSH AWAY OVER THE
WEEKEND...ALLOWING SURFACE HIGH PRESSURE TO NOSE INTO THE REGION
BY MONDAY. HOWEVER...NORTHWEST WINDS AND SEVERAL DISTURBANCES
SHOULD RESULT IN A FEW SHOWERS AND STORMS.
A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON TUESDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CONVECTION ROLLING THROUGH THE AREA IS NOW PAST THE OHIO RIVER.
CAN EXPECT TSRA AT CRW AND CKB OVER THE NEXT FEW HOURS...AND WITH
SOME UNCERTAINTY OF THE EVOLUTION...CARRY PREVAILING VCTS AT EKN
AND BKW...WITH TEMPO TSRA. IFR POSSIBLE IN ALL OF THESE SCENARIOS.
COLD FRONT PASSES THROUGH THIS EVENING INTO TONIGHT...AND WILL S
GET CLEARING FROM WEST TO EAST BY DAWN...WITH THE EXCEPTION OF THE
EASTERN MOUNTAINS. THE CHALLENGE HERE...ASIDE FROM THE
CONVECTION...IS THE TIMING OF THE CLEARING. WITH SITES SEEING
RAIN...VALLEY FOG IS A GOOD BET TONIGHT WHEN RADIATION OCCURS.
LIFR LIKELY AT PKB...HTS...AND CRW...AND SHOULD MATERIALIZE FAIRLY
QUICKLY UPON CLEARING. TAFS CURRENTLY HAVE ROUGHLY A 2 HOUR BUFFER
FROM CLEARING TO LIFR VISIBILITIES...BUT THAT MAY BE TOO GENEROUS.
00Z ISSUANCE COULD TELL THE SAME STORY...BUT HAVE MUCH DIFFERENT
TIMING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: EVOLUTION OF CONVECTION AND CLEARING LATER
THIS EVENING AND TONIGHT LIKELY TO PLAY HAVOC WITH THE FORECAST
OVER THE NEXT FEW HOURS. AMENDMENTS LIKELY.
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 M H H H H H H H
HTS CONSISTENCY H M M M M H H H H H H L
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 M M M M H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR IN STORMS POSSIBLE FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/26
NEAR TERM...ARJ/26
SHORT TERM...JSH
LONG TERM...JSH
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 PM EDT TUE MAY 29 2012
.SYNOPSIS...
COLD FRONT BRINGS SHOWERS AND POSSIBLE SEVERE STORMS THIS AFTERNOON
AND EVENING. FRONT BECOMES DIFFUSE LATE TONIGHT. DRIER WEDNESDAY.
STRONGER WAVE AND FRONT LIKELY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
CONVECTION FURTHER TO THE SOUTHWEST IN WEST CENTRAL KENTUCKY HAS
CUT OFF THE MOISTURE SUPPLY INTO SOUTHERN OHIO...WHICH HAS
ESSENTIALLY KILLED THE SHOWERS AND STORMS BEHIND THE MAIN LINE
THAT IS NOT SOUTH/EAST OF THE OHIO RIVER. THEREFORE...HAVE TRIMMED
BACK SIGNIFICANTLY...BUT NOT ELIMINATED...THE POPS OVER THIS
AREA...WHERE IT APPEARS THE BULK OF THE CONVECTION MAY BE THROUGH
FOR NOW. OTHERWISE...HAVE ACCELERATED THE EASTWARD POPS A BIT FROM
THIS MORNING...AND CUT BACK ON THE END TIMING LATER TONIGHT.
PREVIOUS DISCUSSION...
MOSTLY CLEAR SKIES DURING THE EARLY MORNING HOURS...WILL BECOME
MOSTLY CLOUDY AS CONVECTION ASSOCIATED WITH AN APPROACHING COLD
FRONT SPREADS WEST TO EAST ACROSS THE REGION. SATELLITE IMAGES AND
LIGHTNING DATA INDICATES COLD FRONT OVER IL AROUND 08Z. SOME
CONVECTION IS EVIDENT WELL AHEAD OF THE COLD FRONT OVER INDIANA AT
THE SAME TIME.
ALTHOUGH A TRACKING TOOL BRINGS THE CONVECTION ASSOCIATED WITH
THE FRONT INTO SOUTHEAST OH BY 15Z...BELIEVE THAT CONVECTION WILL
DIE OFF...WHILE ADDITIONAL STORMS REDEVELOP ACROSS KY AND OH...TO
PRODUCE A DELAY ON THE ACTUAL FRONT. MOST MODEL GUIDANCE AGREE
WITH THIS SLOWER SOLUTION WITH THE FRONT...REACHING SOUTHEAST OH
BY 18-21Z...THEN SPREADING SLOWLY EAST ACROSS WV THROUGH 00Z
WEDNESDAY. CODED POPS ACCORDINGLY WITH THIS SLOWER SOLUTION HAVING
CATEGORICAL POPS.
MOST SOUTHEAST OH...AND THE WESTERN HALF OF WV REMAINS IN A SLIGHT
RISK FOR SEVERE STORMS TODAY. SEVERE STORMS ARE EXPECTED TO
DEVELOP UNDER A THERMODYNAMICALLY ENVIRONMENT...WITH HIGH SFC
BASED CAPE EXCEEDING 2500 J/KG OVER BOUNDARY LAYERED CONVERGENCE
PRODUCED BY THE FRONT AND OUTFLOW BOUNDARIES ASSOCIATED WITH
UPSTREAM CONVECTION. BUFKIT SOUNDINGS FROM NAM AND RUC SHOW A
THICK CAPE FEATURE WITH PW AROUND 1.7 INCHES...WITH EQUILIBRIUM
LEVELS REACHING 3500 FEET UNDER WEAK DEEP LAYERED SHEAR. WITH
FREEZING LEVELS AROUND 11000 FEET...VERY STRONG UPDRAFTS COULD
PRODUCE LARGE HAIL...AND DAMAGING DOWNBURSTS.
THE PCPN ACTIVITY SHOULD BE OVER THE EASTERN MOUNTAINS BY
03Z...WHILE THE COLD FRONT DEBILITATES AS IT ENTERS INTO WV.
LOOKING AT BASE PARAMETERS...THERE IS A GOOD INDICATION THAT THE
FRONT LOSES ITS PUNCH AND BECOME DIFFUSE OR NEARLY STATIONARY
ACROSS WV LATE THIS AFTERNOON AND EVENING.
AREAS OF FOG WILL BE COMMON TUESDAY NIGHT INTO WEDNESDAY MORNING
PER ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...ESPECIALLY
OVER AREAS THAT RECEIVE RAIN. LOW LEVEL STRATUS ARE LIKELY TO
PERSIST OVERNIGHT MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS THRU
EARLY WEDNESDAY.
MINOR CHANGES NOTED IN TEMPERATURES THROUGH THE PERIOD.
GENERALLY...EXPECT MID TO UPPER 80S LOWLANDS DUE TO CLOUD COVER
AND PERIODS OF RAIN...TODAY. LOWS WILL REMAIN IN THE 60S DUE TO
HIGH DEWPOINTS TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
BY 12Z WED THE MOISTURE ASSOC WITH THE COLD FRONT TUESDAY WILL BE
WELL EAST OF THE FORECAST AREA. GOOD LARGE SCALE FORCING FOR ASCENT
BEGINS TO OVERSPREAD THE AREA FROM THE WEST. A GOOD AMOUNT OF LOW
LEVEL MOISTURE WILL BE TRAPPED AGAINST THE EASTERN MOUNTAINS ON
WEST/NW WINDS PER 925MB RH PLOTS BUT AT THIS POINT IT APPEARS THINGS
WILL BE VERY DRY ABOVE THIS AT 850MB ON NORTHERLY WINDS...SO WILL
KEEP FORECAST DRY BY THIS TIME WITH LOW STRATUS IN PLACE...WHICH
WILL BURN OFF RAPIDLY BY MID-MORNING. INHERITED MAXES LOOK GOOD WITH
HIGHS IN THE LOWER/MID 80S LOWLANDS WITH 70S EASTERN HIGH TERRAIN.
MEANWHILE VARIOUS SHORT-TERM NWP DEPICTING A COLD FRONT/SFC BOUNDARY
PUSHING INTO THE NW ZONES. NOT EXPECTING ENOUGH LLVL MOISTURE BEFORE
OR BY 18Z TO GENERATE ANY CONVECTION. MID-LEVEL MOISTURE IS ON THE
INCREASE ACROSS THE NW ZONES BY 18Z BUT WITH LCL/S OF
4-5KFT...DOESN/T APPEAR THAT ANY SFC CONVERGENCE WOULD BE STRONG
ENOUGH TO INITIATE CONVECTION AT THIS POINT AND WILL LOWER POPS TO
HIGH SILENTS ACROSS NW ZONES. LATER IN THE AFTERNOON DEEPER MOISTURE
ARRIVES ROUGHLY HTS-CRW-CKB AND POINTS NW OF THAT...ALBEIT MUCH OF
IT WILL RESIDE ABOVE 800MB. IN ADDITION...A BIT MORE ORGANIZED
CONVERGENCE IS NOTED AS WELL ACROSS NW ZONES AS STRONGER COLD FRONT
ENTERS NW ZONES WHILE A WEAK S/W TROUGH APPROACHES FROM THE WEST.
LIKE INHERITED POPS FOR THIS PERIOD AND WILL MAKE ONLY MINOR
TWEAKS...REFLECTING SLIGHTLY BETTER CHANCES ACROSS NW AROUND 21Z AND
FURTHER EAST AROUND 00Z AS ANY SHOWERS/STORMS PROGRESS EASTWARD.
WED NIGHT AS USUAL ANY CONVECTIVE ACTIVITY WILL DIMINISH WITH THE
LOSS OF DAYTIME HEATING. BEHIND THE SECONDARY FRONT WINDS VEER FROM
NW TO N BY DAYBREAK. SLIGHTLY COOLER AIR WILL ALSO ARRIVE WITH MINS
DROPPING INTO THE MID/UPPER 50S MOST LOWLAND LOCATIONS...WITH NEAR
50 DEGREES EASTERN HIGHLANDS. BY THURSDAY NEXT SYSTEM WILL BE
DIGGING ACROSS MIDWEST WITH S/W RIDGING OVERHEAD BY THU 18Z. DID
REMOVE POPS FOR MUCH OF THE FORECAST AREA THURSDAY AS DEEP MOISTURE
DOES NOT ARRIVE UNTIL AFTER 00Z FRI ALONG WITH A STOUT CAP IN PLACE.
FURTHER SOUTH...WILL KEEP SLIGHT CHANCE POPS IN AREAS WHERE CAP IS
REMOVED AND A BIT MORE LLVL MOISTURE IN PLACE. ALSO NUDGED MAXES
DOWN 2-3F DEGREES INTO THE MID/UPPER 70S LOWLANDS EXCEPT FAR SOUTH
WHERE LOW 80S EXPECTED. THURSDAY EVENING BETTER DYNAMICS AND
MOISTURE ARRIVE WITH THE SYSTEM TO THE WEST BRINGING LIKELY
SHOWERS/THUNDERSTORMS TO THE FORECAST AREA FROM SOUTHWEST TO
NORTHEAST BY 06Z FRI. GOOD BET MOST IF NOT ALL LOCATIONS WILL SEE
SOME PRECIP OVERNIGHT BUT WITH UNCERTAINTY IN TIMING CAPPED POPS AT
HIGH LIKELIES FOR NOW.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE PATTERN CHANGE TO COOLER THAN NORMAL TEMPERATURES STILL APPEAR
ON TRACK THIS PERIOD.
A BROAD UPPER LEVEL TROF DEVELOPS OVER THE GREAT LAKES AND MIDWEST
ON THURSDAY INTO FRIDAY...WITH THE DEEPER MOISTURE AND LOW PRESSURE
WAVE SWEEPING THROUGH FRIDAY. NOT A COMMON FEATURE HERE...BUT HAVE
GONE WITH LIKELY POPS...SINCE MODELS CONTINUE TO BE FAIRLY
CONSISTENT WITH THIS FEATURE. HAVE POPS INCREASING THURSDAY
AFTERNOON INTO THURSDAY NIGHT...THEN DECREASING FRIDAY NIGHT. CANNOT
RULE OUT SEVERE.
STILL PROJECTING A NICE COOL DOWN FOR THE WEEKEND INTO MONDAY. A FEW
LIGHTER SHOWERS MAY LINGER ON SATURDAY IN THE LEFTOVER LOW LEVEL
MOISTURE...THEN POPS AOB 14 SATURDAY NIGHT INTO SUNDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CONVECTION ROLLING THROUGH THE AREA IS NOW PAST THE OHIO RIVER.
CAN EXPECT TSRA AT CRW AND CKB OVER THE NEXT FEW HOURS...AND WITH
SOME UNCERTAINTY OF THE EVOLUTION...CARRY PREVAILING VCTS AT EKN
AND BKW...WITH TEMPO TSRA. IFR POSSIBLE IN ALL OF THESE SCENARIOS.
COLD FRONT PASSES THROUGH THIS EVENING INTO TONIGHT...AND WILL S
GET CLEARING FROM WEST TO EAST BY DAWN...WITH THE EXCEPTION OF THE
EASTERN MOUNTAINS. THE CHALLENGE HERE...ASIDE FROM THE
CONVECTION...IS THE TIMING OF THE CLEARING. WITH SITES SEEING
RAIN...VALLEY FOG IS A GOOD BET TONIGHT WHEN RADIATION OCCURS.
LIFR LIKELY AT PKB...HTS...AND CRW...AND SHOULD MATERIALIZE FAIRLY
QUICKLY UPON CLEARING. TAFS CURRENTLY HAVE ROUGHLY A 2 HOUR BUFFER
FROM CLEARING TO LIFR VISIBILITIES...BUT THAT MAY BE TOO GENEROUS.
00Z ISSUANCE COULD TELL THE SAME STORY...BUT HAVE MUCH DIFFERENT
TIMING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: EVOLUTION OF CONVECTION AND CLEARING LATER
THIS EVENING AND TONIGHT LIKELY TO PLAY HAVOC WITH THE FORECAST
OVER THE NEXT FEW HOURS. AMENDMENTS LIKELY.
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 M H H H H H H H
HTS CONSISTENCY H M M M M H H H H H H L
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 M M M M H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR IN STORMS POSSIBLE FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...KTB/JMV
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1010 AM EDT TUE MAY 29 2012
.SYNOPSIS...
COLD FRONT BRINGS SHOWERS AND POSSIBLE SEVERE STORMS THIS AFTERNOON
AND EVENING. FRONT BECOMES DIFFUSE LATE TONIGHT. DRIER WEDNESDAY.
STRONGER WAVE AND FRONT LIKELY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
DESTABILIZATION ALREADY OCCURRING...AND HAVE DEEPER CONVECTION
TAKING PLACE OVER THE OHIO RIVER VALLEY. WILL EXPECT COVERAGE TO
INCREASE OVER THE NEXT FEW HOURS. STORMS WILL HAVE HEALTHY
RAINFALL RATES AND THE POTENTIAL FOR HAIL...ALTHOUGH WILL NEED
VERTICAL EXTENT ABOVE 30KFT FOR SEVERE HAIL. 0-6KM BULK SHEAR
VECTORS TO INCREASE TO 35KTS THIS AFTERNOON.
PREVIOUS DISCUSSION...
MOSTLY CLEAR SKIES DURING THE EARLY MORNING HOURS...WILL BECOME
MOSTLY CLOUDY AS CONVECTION ASSOCIATED WITH AN APPROACHING COLD
FRONT SPREADS WEST TO EAST ACROSS THE REGION. SATELLITE IMAGES AND
LIGHTNING DATA INDICATES COLD FRONT OVER IL AROUND 08Z. SOME
CONVECTION IS EVIDENT WELL AHEAD OF THE COLD FRONT OVER INDIANA AT
THE SAME TIME.
ALTHOUGH A TRACKING TOOL BRINGS THE CONVECTION ASSOCIATED WITH
THE FRONT INTO SOUTHEAST OH BY 15Z...BELIEVE THAT CONVECTION WILL
DIE OFF...WHILE ADDITIONAL STORMS REDEVELOP ACROSS KY AND OH...TO
PRODUCE A DELAY ON THE ACTUAL FRONT. MOST MODEL GUIDANCE AGREE
WITH THIS SLOWER SOLUTION WITH THE FRONT...REACHING SOUTHEAST OH
BY 18-21Z...THEN SPREADING SLOWLY EAST ACROSS WV THROUGH 00Z
WEDNESDAY. CODED POPS ACCORDINGLY WITH THIS SLOWER SOLUTION HAVING
CATEGORICAL POPS.
MOST SOUTHEAST OH...AND THE WESTERN HALF OF WV REMAINS IN A SLIGHT
RISK FOR SEVERE STORMS TODAY. SEVERE STORMS ARE EXPECTED TO
DEVELOP UNDER A THERMODYNAMICALLY ENVIRONMENT...WITH HIGH SFC
BASED CAPE EXCEEDING 2500 J/KG OVER BOUNDARY LAYERED CONVERGENCE
PRODUCED BY THE FRONT AND OUTFLOW BOUNDARIES ASSOCIATED WITH
UPSTREAM CONVECTION. BUFKIT SOUNDINGS FROM NAM AND RUC SHOW A
THICK CAPE FEATURE WITH PW AROUND 1.7 INCHES...WITH EQUILIBRIUM
LEVELS REACHING 3500 FEET UNDER WEAK DEEP LAYERED SHEAR. WITH
FREEZING LEVELS AROUND 11000 FEET...VERY STRONG UPDRAFTS COULD
PRODUCE LARGE HAIL...AND DAMAGING DOWNBURSTS.
THE PCPN ACTIVITY SHOULD BE OVER THE EASTERN MOUNTAINS BY
03Z...WHILE THE COLD FRONT DEBILITATES AS IT ENTERS INTO WV.
LOOKING AT BASE PARAMETERS...THERE IS A GOOD INDICATION THAT THE
FRONT LOSES ITS PUNCH AND BECOME DIFFUSE OR NEARLY STATIONARY
ACROSS WV LATE THIS AFTERNOON AND EVENING.
AREAS OF FOG WILL BE COMMON TUESDAY NIGHT INTO WEDNESDAY MORNING
PER ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...ESPECIALLY
OVER AREAS THAT RECEIVE RAIN. LOW LEVEL STRATUS ARE LIKELY TO
PERSIST OVERNIGHT MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS THRU
EARLY WEDNESDAY.
MINOR CHANGES NOTED IN TEMPERATURES THROUGH THE PERIOD.
GENERALLY...EXPECT MID TO UPPER 80S LOWLANDS DUE TO CLOUD COVER
AND PERIODS OF RAIN...TODAY. LOWS WILL REMAIN IN THE 60S DUE TO
HIGH DEWPOINTS TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
BY 12Z WED THE MOISTURE ASSOC WITH THE COLD FRONT TUESDAY WILL BE
WELL EAST OF THE FORECAST AREA. GOOD LARGE SCALE FORCING FOR ASCENT
BEGINS TO OVERSPREAD THE AREA FROM THE WEST. A GOOD AMOUNT OF LOW
LEVEL MOISTURE WILL BE TRAPPED AGAINST THE EASTERN MOUNTAINS ON
WEST/NW WINDS PER 925MB RH PLOTS BUT AT THIS POINT IT APPEARS THINGS
WILL BE VERY DRY ABOVE THIS AT 850MB ON NORTHERLY WINDS...SO WILL
KEEP FORECAST DRY BY THIS TIME WITH LOW STRATUS IN PLACE...WHICH
WILL BURN OFF RAPIDLY BY MID-MORNING. INHERITED MAXES LOOK GOOD WITH
HIGHS IN THE LOWER/MID 80S LOWLANDS WITH 70S EASTERN HIGH TERRAIN.
MEANWHILE VARIOUS SHORT-TERM NWP DEPICTING A COLD FRONT/SFC BOUNDARY
PUSHING INTO THE NW ZONES. NOT EXPECTING ENOUGH LLVL MOISTURE BEFORE
OR BY 18Z TO GENERATE ANY CONVECTION. MID-LEVEL MOISTURE IS ON THE
INCREASE ACROSS THE NW ZONES BY 18Z BUT WITH LCL/S OF
4-5KFT...DOESN/T APPEAR THAT ANY SFC CONVERGENCE WOULD BE STRONG
ENOUGH TO INITIATE CONVECTION AT THIS POINT AND WILL LOWER POPS TO
HIGH SILENTS ACROSS NW ZONES. LATER IN THE AFTERNOON DEEPER MOISTURE
ARRIVES ROUGHLY HTS-CRW-CKB AND POINTS NW OF THAT...ALBEIT MUCH OF
IT WILL RESIDE ABOVE 800MB. IN ADDITION...A BIT MORE ORGANIZED
CONVERGENCE IS NOTED AS WELL ACROSS NW ZONES AS STRONGER COLD FRONT
ENTERS NW ZONES WHILE A WEAK S/W TROUGH APPROACHES FROM THE WEST.
LIKE INHERITED POPS FOR THIS PERIOD AND WILL MAKE ONLY MINOR
TWEAKS...REFLECTING SLIGHTLY BETTER CHANCES ACROSS NW AROUND 21Z AND
FURTHER EAST AROUND 00Z AS ANY SHOWERS/STORMS PROGRESS EASTWARD.
WED NIGHT AS USUAL ANY CONVECTIVE ACTIVITY WILL DIMINISH WITH THE
LOSS OF DAYTIME HEATING. BEHIND THE SECONDARY FRONT WINDS VEER FROM
NW TO N BY DAYBREAK. SLIGHTLY COOLER AIR WILL ALSO ARRIVE WITH MINS
DROPPING INTO THE MID/UPPER 50S MOST LOWLAND LOCATIONS...WITH NEAR
50 DEGREES EASTERN HIGHLANDS. BY THURSDAY NEXT SYSTEM WILL BE
DIGGING ACROSS MIDWEST WITH S/W RIDGING OVERHEAD BY THU 18Z. DID
REMOVE POPS FOR MUCH OF THE FORECAST AREA THURSDAY AS DEEP MOISTURE
DOES NOT ARRIVE UNTIL AFTER 00Z FRI ALONG WITH A STOUT CAP IN PLACE.
FURTHER SOUTH...WILL KEEP SLIGHT CHANCE POPS IN AREAS WHERE CAP IS
REMOVED AND A BIT MORE LLVL MOISTURE IN PLACE. ALSO NUDGED MAXES
DOWN 2-3F DEGREES INTO THE MID/UPPER 70S LOWLANDS EXCEPT FAR SOUTH
WHERE LOW 80S EXPECTED. THURSDAY EVENING BETTER DYNAMICS AND
MOISTURE ARRIVE WITH THE SYSTEM TO THE WEST BRINGING LIKELY
SHOWERS/THUNDERSTORMS TO THE FORECAST AREA FROM SOUTHWEST TO
NORTHEAST BY 06Z FRI. GOOD BET MOST IF NOT ALL LOCATIONS WILL SEE
SOME PRECIP OVERNIGHT BUT WITH UNCERTAINTY IN TIMING CAPPED POPS AT
HIGH LIKELIES FOR NOW.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE PATTERN CHANGE TO COOLER THAN NORMAL TEMPERATURES STILL APPEAR
ON TRACK THIS PERIOD.
A BROAD UPPER LEVEL TROF DEVELOPS OVER THE GREAT LAKES AND MIDWEST
ON THURSDAY INTO FRIDAY...WITH THE DEEPER MOISTURE AND LOW PRESSURE
WAVE SWEEPING THROUGH FRIDAY. NOT A COMMON FEATURE HERE...BUT HAVE
GONE WITH LIKELY POPS...SINCE MODELS CONTINUE TO BE FAIRLY
CONSISTENT WITH THIS FEATURE. HAVE POPS INCREASING THURSDAY
AFTERNOON INTO THURSDAY NIGHT...THEN DECREASING FRIDAY NIGHT. CANNOT
RULE OUT SEVERE.
STILL PROJECTING A NICE COOL DOWN FOR THE WEEKEND INTO MONDAY. A FEW
LIGHTER SHOWERS MAY LINGER ON SATURDAY IN THE LEFTOVER LOW LEVEL
MOISTURE...THEN POPS AOB 14 SATURDAY NIGHT INTO SUNDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS PREVAILING FOR THE MOST PART THIS MORNING UNDER
MOSTLY CLEAR SKIES.
AN APPROACHING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS
INTO THE SOUTHEAST OH TUESDAY AFTERNOON...AND SPREAD SLOWLY EAST
INTO CENTRAL WV AND EASTERN MOUNTAINS THROUGH 00Z WED. MVFR/IFR
VISIBILITIES WILL BE POSSIBLE ALONG THE HEAVIEST SHOWERS. STRONG
TO SEVERE DAMAGING WINDS AND LARGE HAIL WILL ACCOMPANY THE
STRONGEST STORMS. SITES MORE VULNERABLE TO BE AFFECTED WILL BE PKB
CRW AND HTS BETWEEN 18 TO 22Z.
LOCALIZED HEAVY RAIN WILL ALSO BE POSSIBLE. AFTER 00Z WED...MOST
MODELS TAKE THE PCPN EAST ALONG THE EASTERN MOUNTAINS. EXPECT
IFR/LIFR CONDITIONS OVER AREAS THAT RECEIVE RAINFALL AFTER 06Z
WEDNESDAY INTO 12-13Z WEDNESDAY MAINLY WEST.
SOME LINGERING LOW LEVEL MOISTURE IS POSSIBLE WEDNESDAY
NIGHT...PARTICULARLY ACROSS WEST VIRGINIA AND SOUTHWEST
VIRGINIA...LEADING TO THE POTENTIAL FOR LOW STRATUS WESTERN SLOPES
AND ALONG EASTERN MOUNTAINS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: TIMING OF CONVECTION AHEAD OF THE FRONT
TUESDAY AFTERNOON MAY VARY. INTENSITY AND LOCATION OF FOG AND LOW
STRATUS MAY VARY AS WELL.
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 M H M
HTS CONSISTENCY H H H H H H M M M M 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 M M M H H H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 12Z WEDNESDAY...
POST RAIN IFR STRATUS AND FOG EARLY WEDNESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...KTB/JMV
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
646 AM EDT TUE MAY 29 2012
.SYNOPSIS...
COLD FRONT BRINGS SHOWERS AND POSSIBLE SEVERE STORMS THIS AFTERNOON
AND EVENING. FRONT BECOMES DIFFUSE LATE TONIGHT. DRIER WEDNESDAY.
STRONGER WAVE AND FRONT LIKELY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOSTLY CLEAR SKIES DURING THE EARLY MORNING HOURS...WILL BECOME
MOSTLY CLOUDY AS CONVECTION ASSOCIATED WITH AN APPROACHING COLD
FRONT SPREADS WEST TO EAST ACROSS THE REGION. SATELLITE IMAGES AND
LIGHTNING DATA INDICATES COLD FRONT OVER IL AROUND 08Z. SOME
CONVECTION IS EVIDENT WELL AHEAD OF THE COLD FRONT OVER INDIANA AT
THE SAME TIME.
ALTHOUGH A TRACKING TOOL BRINGS THE CONVECTION ASSOCIATED WITH
THE FRONT INTO SOUTHEAST OH BY 15Z...BELIEVE THAT CONVECTION WILL
DIE OFF...WHILE ADDITIONAL STORMS REDEVELOP ACROSS KY AND OH...TO
PRODUCE A DELAY ON THE ACTUAL FRONT. MOST MODEL GUIDANCE AGREE
WITH THIS SLOWER SOLUTION WITH THE FRONT...REACHING SOUTHEAST OH
BY 18-21Z...THEN SPREADING SLOWLY EAST ACROSS WV THROUGH 00Z
WEDNESDAY. CODED POPS ACCORDINGLY WITH THIS SLOWER SOLUTION HAVING
CATEGORICAL POPS.
MOST SOUTHEAST OH...AND THE WESTERN HALF OF WV REMAINS IN A SLIGHT
RISK FOR SEVERE STORMS TODAY. SEVERE STORMS ARE EXPECTED TO
DEVELOP UNDER A THERMODYNAMICALLY ENVIRONMENT...WITH HIGH SFC
BASED CAPE EXCEEDING 2500 J/KG OVER BOUNDARY LAYERED CONVERGENCE
PRODUCED BY THE FRONT AND OUTFLOW BOUNDARIES ASSOCIATED WITH
UPSTREAM CONVECTION. BUFKIT SOUNDINGS FROM NAM AND RUC SHOW A
THICK CAPE FEATURE WITH PW AROUND 1.7 INCHES...WITH EQUILIBRIUM
LEVELS REACHING 3500 FEET UNDER WEAK DEEP LAYERED SHEAR. WITH
FREEZING LEVELS AROUND 11000 FEET...VERY STRONG UPDRAFTS COULD
PRODUCE LARGE HAIL...AND DAMAGING DOWNBURSTS.
THE PCPN ACTIVITY SHOULD BE OVER THE EASTERN MOUNTAINS BY
03Z...WHILE THE COLD FRONT DEBILITATES AS IT ENTERS INTO WV.
LOOKING AT BASE PARAMETERS...THERE IS A GOOD INDICATION THAT THE
FRONT LOSES ITS PUNCH AND BECOME DIFFUSE OR NEARLY STATIONARY
ACROSS WV LATE THIS AFTERNOON AND EVENING.
AREAS OF FOG WILL BE COMMON TUESDAY NIGHT INTO WEDNESDAY MORNING
PER ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...ESPECIALLY
OVER AREAS THAT RECEIVE RAIN. LOW LEVEL STRATUS ARE LIKELY TO
PERSIST OVERNIGHT MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS THRU
EARLY WEDNESDAY.
MINOR CHANGES NOTED IN TEMPERATURES THROUGH THE PERIOD.
GENERALLY...EXPECT MID TO UPPER 80S LOWLANDS DUE TO CLOUD COVER
AND PERIODS OF RAIN...TODAY. LOWS WILL REMAIN IN THE 60S DUE TO
HIGH DEWPOINTS TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
BY 12Z WED THE MOISTURE ASSOC WITH THE COLD FRONT TUESDAY WILL BE
WELL EAST OF THE FORECAST AREA. GOOD LARGE SCALE FORCING FOR ASCENT
BEGINS TO OVERSPREAD THE AREA FROM THE WEST. A GOOD AMOUNT OF LOW
LEVEL MOISTURE WILL BE TRAPPED AGAINST THE EASTERN MOUNTAINS ON
WEST/NW WINDS PER 925MB RH PLOTS BUT AT THIS POINT IT APPEARS THINGS
WILL BE VERY DRY ABOVE THIS AT 850MB ON NORTHERLY WINDS...SO WILL
KEEP FORECAST DRY BY THIS TIME WITH LOW STRATUS IN PLACE...WHICH
WILL BURN OFF RAPIDLY BY MID-MORNING. INHERITED MAXES LOOK GOOD WITH
HIGHS IN THE LOWER/MID 80S LOWLANDS WITH 70S EASTERN HIGH TERRAIN.
MEANWHILE VARIOUS SHORT-TERM NWP DEPICTING A COLD FRONT/SFC BOUNDARY
PUSHING INTO THE NW ZONES. NOT EXPECTING ENOUGH LLVL MOISTURE BEFORE
OR BY 18Z TO GENERATE ANY CONVECTION. MID-LEVEL MOISTURE IS ON THE
INCREASE ACROSS THE NW ZONES BY 18Z BUT WITH LCL/S OF
4-5KFT...DOESN/T APPEAR THAT ANY SFC CONVERGENCE WOULD BE STRONG
ENOUGH TO INITIATE CONVECTION AT THIS POINT AND WILL LOWER POPS TO
HIGH SILENTS ACROSS NW ZONES. LATER IN THE AFTERNOON DEEPER MOISTURE
ARRIVES ROUGHLY HTS-CRW-CKB AND POINTS NW OF THAT...ALBEIT MUCH OF
IT WILL RESIDE ABOVE 800MB. IN ADDITION...A BIT MORE ORGANIZED
CONVERGENCE IS NOTED AS WELL ACROSS NW ZONES AS STRONGER COLD FRONT
ENTERS NW ZONES WHILE A WEAK S/W TROUGH APPROACHES FROM THE WEST.
LIKE INHERITED POPS FOR THIS PERIOD AND WILL MAKE ONLY MINOR
TWEAKS...REFLECTING SLIGHTLY BETTER CHANCES ACROSS NW AROUND 21Z AND
FURTHER EAST AROUND 00Z AS ANY SHOWERS/STORMS PROGRESS EASTWARD.
WED NIGHT AS USUAL ANY CONVECTIVE ACTIVITY WILL DIMINISH WITH THE
LOSS OF DAYTIME HEATING. BEHIND THE SECONDARY FRONT WINDS VEER FROM
NW TO N BY DAYBREAK. SLIGHTLY COOLER AIR WILL ALSO ARRIVE WITH MINS
DROPPING INTO THE MID/UPPER 50S MOST LOWLAND LOCATIONS...WITH NEAR
50 DEGREES EASTERN HIGHLANDS. BY THURSDAY NEXT SYSTEM WILL BE
DIGGING ACROSS MIDWEST WITH S/W RIDGING OVERHEAD BY THU 18Z. DID
REMOVE POPS FOR MUCH OF THE FORECAST AREA THURSDAY AS DEEP MOISTURE
DOES NOT ARRIVE UNTIL AFTER 00Z FRI ALONG WITH A STOUT CAP IN PLACE.
FURTHER SOUTH...WILL KEEP SLIGHT CHANCE POPS IN AREAS WHERE CAP IS
REMOVED AND A BIT MORE LLVL MOISTURE IN PLACE. ALSO NUDGED MAXES
DOWN 2-3F DEGREES INTO THE MID/UPPER 70S LOWLANDS EXCEPT FAR SOUTH
WHERE LOW 80S EXPECTED. THURSDAY EVENING BETTER DYNAMICS AND
MOISTURE ARRIVE WITH THE SYSTEM TO THE WEST BRINGING LIKELY
SHOWERS/THUNDERSTORMS TO THE FORECAST AREA FROM SOUTHWEST TO
NORTHEAST BY 06Z FRI. GOOD BET MOST IF NOT ALL LOCATIONS WILL SEE
SOME PRECIP OVERNIGHT BUT WITH UNCERTAINTY IN TIMING CAPPED POPS AT
HIGH LIKELIES FOR NOW.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE PATTERN CHANGE TO COOLER THAN NORMAL TEMPERATURES STILL APPEAR
ON TRACK THIS PERIOD.
A BROAD UPPER LEVEL TROF DEVELOPS OVER THE GREAT LAKES AND MIDWEST
ON THURSDAY INTO FRIDAY...WITH THE DEEPER MOISTURE AND LOW PRESSURE
WAVE SWEEPING THROUGH FRIDAY. NOT A COMMON FEATURE HERE...BUT HAVE
GONE WITH LIKELY POPS...SINCE MODELS CONTINUE TO BE FAIRLY
CONSISTENT WITH THIS FEATURE. HAVE POPS INCREASING THURSDAY
AFTERNOON INTO THURSDAY NIGHT...THEN DECREASING FRIDAY NIGHT. CANNOT
RULE OUT SEVERE.
STILL PROJECTING A NICE COOL DOWN FOR THE WEEKEND INTO MONDAY. A FEW
LIGHTER SHOWERS MAY LINGER ON SATURDAY IN THE LEFTOVER LOW LEVEL
MOISTURE...THEN POPS AOB 14 SATURDAY NIGHT INTO SUNDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS PREVAILING FOR THE MOST PART THIS MORNING UNDER
MOSTLY CLEAR SKIES.
AN APPROACHING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS
INTO THE SOUTHEAST OH TUESDAY AFTERNOON...AND SPREAD SLOWLY EAST
INTO CENTRAL WV AND EASTERN MOUNTAINS THROUGH 00Z WED. MVFR/IFR
VISIBILITIES WILL BE POSSIBLE ALONG THE HEAVIEST SHOWERS. STRONG
TO SEVERE DAMAGING WINDS AND LARGE HAIL WILL ACCOMPANY THE
STRONGEST STORMS. SITES MORE VULNERABLE TO BE AFFECTED WILL BE PKB
...CRW AND HTS BETWEEN 18 TO 22Z.
LOCALIZED HEAVY RAIN WILL ALSO BE POSSIBLE. AFTER 00Z WED...MOST
MODELS TAKE THE PCPN EAST ALONG THE EASTERN MOUNTAINS. EXPECT
IFR/LIFR CONDITIONS OVER AREAS THAT RECEIVE RAINFALL AFTER 06Z
WEDNESDAY INTO 12-13Z WEDNESDAY MAINLY WEST.
SOME LINGERING LOW LEVEL MOISTURE IS POSSIBLE WEDNESDAY
NIGHT...PARTICULARLY ACROSS WEST VIRGINIA AND SOUTHWEST
VIRGINIA...LEADING TO THE POTENTIAL FOR LOW STRATUS WESTERN SLOPES
AND ALONG EASTERN MOUNTAINS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: TIMING OF CONVECTION AHEAD OF THE FRONT
TUESDAY AFTERNOON MAY VARY. INTENSITY AND LOCATION OF FOG AND LOW
STRATUS MAY VARY AS WELL.
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 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
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 M M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
POST RAIN IFR STRATUS AND FOG EARLY WEDNESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...KTB/JMV
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
428 AM EDT TUE MAY 29 2012
.SYNOPSIS...
COLD FRONT BRINGS SHOWERS AND POSSIBLE SEVERE STORMS THIS AFTERNOON
AND EVENING. FRONT BECOMES DIFFUSE LATE TONIGHT. DRIER WEDNESDAY.
STRONGER WAVE AND FRONT LIKELY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOSTLY CLEAR SKIES DURING THE EARLY MORNING HOURS...WILL BECOME
MOSTLY CLOUDY AS CONVECTION ASSOCIATED WITH AN APPROACHING COLD
FRONT SPREADS WEST TO EAST ACROSS THE REGION. SATELLITE IMAGES AND
LIGHTNING DATA INDICATES COLD FRONT OVER IL AROUND 08Z. SOME
CONVECTION IS EVIDENT WELL AHEAD OF THE COLD FRONT OVER INDIANA AT
THE SAME TIME.
ALTHOUGH A TRACKING TOOL BRINGS THE CONVECTION ASSOCIATED WITH
THE FRONT INTO SOUTHEAST OH BY 15Z...BELIEVE THAT CONVECTION WILL
DIE OFF...WHILE ADDITIONAL STORMS REDEVELOP ACROSS KY AND OH...TO
PRODUCE A DELAY ON THE ACTUAL FRONT. MOST MODEL GUIDANCE AGREE
WITH THIS SLOWER SOLUTION WITH THE FRONT...REACHING SOUTHEAST OH
BY 18-21Z...THEN SPREADING SLOWLY EAST ACROSS WV THROUGH 00Z
WEDNESDAY. CODED POPS ACCORDINGLY WITH THIS SLOWER SOLUTION HAVING
CATEGORICAL POPS.
MOST SOUTHEAST OH...AND THE WESTERN HALF OF WV REMAINS IN A SLIGHT
RISK FOR SEVERE STORMS TODAY. SEVERE STORMS ARE EXPECTED TO
DEVELOP UNDER A THERMODYNAMICALLY ENVIRONMENT...WITH HIGH SFC
BASED CAPE EXCEEDING 2500 J/KG OVER BOUNDARY LAYERED CONVERGENCE
PRODUCED BY THE FRONT AND OUTFLOW BOUNDARIES ASSOCIATED WITH
UPSTREAM CONVECTION. BUFKIT SOUNDINGS FROM NAM AND RUC SHOW A
THICK CAPE FEATURE WITH PW AROUND 1.7 INCHES...WITH EQUILIBRIUM
LEVELS REACHING 3500 FEET UNDER WEAK DEEP LAYERED SHEAR. WITH
FREEZING LEVELS AROUND 11000 FEET...VERY STRONG UPDRAFTS COULD
PRODUCE LARGE HAIL...AND DAMAGING DOWNBURSTS.
THE PCPN ACTIVITY SHOULD BE OVER THE EASTERN MOUNTAINS BY
03Z...WHILE THE COLD FRONT DEBILITATES AS IT ENTERS INTO WV.
LOOKING AT BASE PARAMETERS...THERE IS A GOOD INDICATION THAT THE
FRONT LOSES ITS PUNCH AND BECOME DIFFUSE OR NEARLY STATIONARY
ACROSS WV LATE THIS AFTERNOON AND EVENING.
AREAS OF FOG WILL BE COMMON TUESDAY NIGHT INTO WEDNESDAY MORNING
PER ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...ESPECIALLY
OVER AREAS THAT RECEIVE RAIN. LOW LEVEL STRATUS ARE LIKELY TO
PERSIST OVERNIGHT MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS THRU
EARLY WEDNESDAY.
MINOR CHANGES NOTED IN TEMPERATURES THROUGH THE PERIOD.
GENERALLY...EXPECT MID TO UPPER 80S LOWLANDS DUE TO CLOUD COVER
AND PERIODS OF RAIN...TODAY. LOWS WILL REMAIN IN THE 60S DUE TO
HIGH DEWPOINTS TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
BY 12Z WED THE MOISTURE ASSOC WITH THE COLD FRONT TUESDAY WILL BE
WELL EAST OF THE FORECAST AREA. GOOD LARGE SCALE FORCING FOR ASCENT
BEGINS TO OVERSPREAD THE AREA FROM THE WEST. A GOOD AMOUNT OF LOW
LEVEL MOISTURE WILL BE TRAPPED AGAINST THE EASTERN MOUNTAINS ON
WEST/NW WINDS PER 925MB RH PLOTS BUT AT THIS POINT IT APPEARS THINGS
WILL BE VERY DRY ABOVE THIS AT 850MB ON NORTHERLY WINDS...SO WILL
KEEP FORECAST DRY BY THIS TIME WITH LOW STRATUS IN PLACE...WHICH
WILL BURN OFF RAPIDLY BY MID-MORNING. INHERITED MAXES LOOK GOOD WITH
HIGHS IN THE LOWER/MID 80S LOWLANDS WITH 70S EASTERN HIGH TERRAIN.
MEANWHILE VARIOUS SHORT-TERM NWP DEPICTING A COLD FRONT/SFC BOUNDARY
PUSHING INTO THE NW ZONES. NOT EXPECTING ENOUGH LLVL MOISTURE BEFORE
OR BY 18Z TO GENERATE ANY CONVECTION. MID-LEVEL MOISTURE IS ON THE
INCREASE ACROSS THE NW ZONES BY 18Z BUT WITH LCL/S OF
4-5KFT...DOESN/T APPEAR THAT ANY SFC CONVERGENCE WOULD BE STRONG
ENOUGH TO INITIATE CONVECTION AT THIS POINT AND WILL LOWER POPS TO
HIGH SILENTS ACROSS NW ZONES. LATER IN THE AFTERNOON DEEPER MOISTURE
ARRIVES ROUGHLY HTS-CRW-CKB AND POINTS NW OF THAT...ALBEIT MUCH OF
IT WILL RESIDE ABOVE 800MB. IN ADDITION...A BIT MORE ORGANIZED
CONVERGENCE IS NOTED AS WELL ACROSS NW ZONES AS STRONGER COLD FRONT
ENTERS NW ZONES WHILE A WEAK S/W TROUGH APPROACHES FROM THE WEST.
LIKE INHERITED POPS FOR THIS PERIOD AND WILL MAKE ONLY MINOR
TWEAKS...REFLECTING SLIGHTLY BETTER CHANCES ACROSS NW AROUND 21Z AND
FURTHER EAST AROUND 00Z AS ANY SHOWERS/STORMS PROGRESS EASTWARD.
WED NIGHT AS USUAL ANY CONVECTIVE ACTIVITY WILL DIMINISH WITH THE
LOSS OF DAYTIME HEATING. BEHIND THE SECONDARY FRONT WINDS VEER FROM
NW TO N BY DAYBREAK. SLIGHTLY COOLER AIR WILL ALSO ARRIVE WITH MINS
DROPPING INTO THE MID/UPPER 50S MOST LOWLAND LOCATIONS...WITH NEAR
50 DEGREES EASTERN HIGHLANDS. BY THURSDAY NEXT SYSTEM WILL BE
DIGGING ACROSS MIDWEST WITH S/W RIDGING OVERHEAD BY THU 18Z. DID
REMOVE POPS FOR MUCH OF THE FORECAST AREA THURSDAY AS DEEP MOISTURE
DOES NOT ARRIVE UNTIL AFTER 00Z FRI ALONG WITH A STOUT CAP IN PLACE.
FURTHER SOUTH...WILL KEEP SLIGHT CHANCE POPS IN AREAS WHERE CAP IS
REMOVED AND A BIT MORE LLVL MOISTURE IN PLACE. ALSO NUDGED MAXES
DOWN 2-3F DEGREES INTO THE MID/UPPER 70S LOWLANDS EXCEPT FAR SOUTH
WHERE LOW 80S EXPECTED. THURSDAY EVENING BETTER DYNAMICS AND
MOISTURE ARRIVE WITH THE SYSTEM TO THE WEST BRINGING LIKELY
SHOWERS/THUNDERSTORMS TO THE FORECAST AREA FROM SOUTHWEST TO
NORTHEAST BY 06Z FRI. GOOD BET MOST IF NOT ALL LOCATIONS WILL SEE
SOME PRECIP OVERNIGHT BUT WITH UNCERTAINTY IN TIMING CAPPED POPS AT
HIGH LIKELIES FOR NOW.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE PATTERN CHANGE TO COOLER THAN NORMAL TEMPERATURES STILL APPEAR
ON TRACK THIS PERIOD.
A BROAD UPPER LEVEL TROF DEVELOPS OVER THE GREAT LAKES AND MIDWEST
ON THURSDAY INTO FRIDAY...WITH THE DEEPER MOISTURE AND LOW PRESSURE
WAVE SWEEPING THROUGH FRIDAY. NOT A COMMON FEATURE HERE...BUT HAVE
GONE WITH LIKELY POPS...SINCE MODELS CONTINUE TO BE FAIRLY
CONSISTENT WITH THIS FEATURE. HAVE POPS INCREASING THURSDAY
AFTERNOON INTO THURSDAY NIGHT...THEN DECREASING FRIDAY NIGHT. CANNOT
RULE OUT SEVERE.
STILL PROJECTING A NICE COOL DOWN FOR THE WEEKEND INTO MONDAY. A FEW
LIGHTER SHOWERS MAY LINGER ON SATURDAY IN THE LEFTOVER LOW LEVEL
MOISTURE...THEN POPS AOB 14 SATURDAY NIGHT INTO SUNDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS PREVAILING FOR THE MOST PART OVERNIGHT UNDER MOSTLY
CLEAR SKIES AND DEWPOINT DEPRESSION ABOUT 4-5 DEGREES.
THE EXCEPTION WILL BE EKN PROTECTED VALLEY WHERE IFR FOG IS
EXPECTED THROUGH AT LEAST 12-13Z UNDER SATURATED CONDITIONS.
AN APPROACHING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS
INTO THE SOUTHEAST OH TUESDAY AFTERNOON...AND SPREAD SLOWLY EAST
INTO CENTRAL WV AND EASTERN MOUNTAINS THROUGH 00Z WED. MVFR/IFR
VISIBILITIES WILL BE POSSIBLE ALONG THE HEAVIEST SHOWERS. STRONG
GUSTY WINDS AND HAIL WILL ACCOMPANY THE STRONGEST STORMS. SOME
STORMS COULD BECOME SEVERE IN THE VICINITY OF PKB...CRW AND HTS.
LOCALIZED HEAVY RAIN WILL ALSO BE POSSIBLE. AFTER 00Z WED...MOST
MODELS TAKE THE PCPN EAST ALONG THE EASTERN MOUNTAINS. EXPECT
IFR/LIFR CONDITIONS OVER AREAS THAT RECEIVE RAINFALL AFTER 06Z
WEDNESDAY INTO 12-13Z WEDNESDAY MAINLY WEST.
SOME LINGERING LOW LEVEL MOISTURE IS POSSIBLE WEDNESDAY
NIGHT...PARTICULARLY ACROSS WEST VIRGINIA AND SOUTHWEST
VIRGINIA...LEADING TO THE POTENTIAL FOR LOW STRATUS WESTERN SLOPES
AND ALONG EASTERN MOUNTAINS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: TIMING OF CONVECTION AHEAD OF THE FRONT
TUESDAY AFTERNOON MAY VARY. INTENSITY AND LOCATION OF FOG AND LOW
STRATUS MAY VARY AS WELL.
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 TUE 05/29/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
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 L L L L L L 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 06Z WEDNESDAY...
POST RAIN IFR STRATUS AND FOG AFTER 06-12Z WEDNESDAY TIME FRAME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...KTB/JMV
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS NORMAN OK
1210 PM CDT TUE MAY 29 2012
.AVIATION...
18Z TAFS... SCATTERED SHOWERS/STORMS WILL DEVELOP LATE THIS
AFTERNOON AND TONIGHT. THERE ARE CHANCES AT ALL TAF SITES BUT TOO
LOW FOR MENTION IN TAFS TO THE WEST. BEST CHANCE WILL BE
KPNC/KOUN/KOKC. STRONG AND VARIABLE WINDS WILL BE POSSIBLE NEAR
ANY STORMS. VFR AND POSSIBLY MVFR CEILINGS WILL AFFECT PARTS OF
THE AREA TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1147 AM CDT TUE MAY 29 2012/
UPDATE...
LOWERED RAIN CHANCES THIS AFTERNOON AND DELAYED THEM UNTIL
AFTER 4 PM CDT. ALSO...INCREASED HIGHS A FEW DEGREES.
DISCUSSION...
SOME SEVERE THUNDERSTORMS CAN BE EXPECTED LATE THIS
AFTERNOON AND EVENING.
THINK RAINFREE CONDITIONS WITH ABUNDANT SUN WILL PREVAIL
THROUGH 4 PM CDT TODAY. INCREASED HIGHS A FEW DEGREES WITH
MOST LOCATIONS IN THE 90S.
BELIEVE THE FIRST FEW STORMS WILL DEVELOP WILL OCCUR NEAR THE
KANSAS AND OKLAHOMA BORDER OR NEAR A DRYLINE SOMEWHERE NEAR A
WOODWARD TO ALTUS LINE BETWEEN 4 AND 7 PM CDT. LATEST HRRR AND
NAM12 HINTED AT THIS DEVELOPMENT. ANY STORMS WILL MOVE EAST OR
SOUTHEAST AND MAY ORGANIZE INTO A CLUSTER/MCS AFTER 7 PM CDT AND
AFFECT LOCATIONS MAINLY NORTHEAST OF A WOODWARD TO DURANT LINE.
THINK THE OKLAHOMA CITY METRO AREA WILL HAVE BEST SHOT FOR STORMS
BETWEEN 6 PM AND MIDNIGHT CDT.
REGARDING SEVERE POTENTIAL...WITH THE FIRST STORM DEVELOPMENT
BELIEVE LARGE...POTENTIALLY VERY LARGE HAIL...POSSIBLY GREATER
THAN TENNIS BALLS...WILL BE THE MAIN HAZARD DUE TO VERY UNSTABLE
AIR WITH 600 TO 900 J/KG BETWEEN -10 AND -30C. DAMAGING WINDS OVER
65 MPH IS ANOTHER HAZARD...ESPECIALLY IF STORMS CAN ORGANIZE INTO
A CLUSTER/LINE/MCS THIS EVENING. DUE TO FAIRLY HIGH CLOUD BASES
AND LACK OF STRONG LOW LEVEL SHEAR...THINK THE TORNADO THREAT
REMAINS LOW. BELIEVE SEVERE POTENTIAL WILL DIMINISH AFTER MIDNIGHT
CDT AS THE AIR BECOMES MORE STABLE.
PRODUCTS HAVE BEEN UPDATED.
MBS
PREV DISCUSSION... /ISSUED 643 AM CDT TUE MAY 29 2012/
AVIATION...
29/12Z...VFR CONDITIONS EXPECTED TO PREVAIL UNTIL LATE THIS
AFTERNOON AND EVENING WHEN SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP ONCE AGAIN. GREATEST IMPACTS EXPECTED NEAR KPNC/KOKC/KOUN
TERMINALS...BUT WILL MENTION PROB30 ACROSS WESTERN OKLAHOMA
TERMINALS. MVFR/IFR RESTRICTIONS EXPECTED NEAR ANY STORMS.
DISCUSSION...
ANOTHER ROUND OF SEVERE WEATHER EXPECTED THIS AFTERNOON AND
EVENING. EXPECTATIONS OF CONVECTIVE INITIATION WILL BE FARTHER
NORTH THAN YESTERDAY...WITH INITIATION PROBABLE ACROSS FAR
NORTHERN OKLAHOMA OR SOUTHERN KANSAS. AN EAST AND SOUTHEAST
PROGRESSION AND UPSCALE GROWTH EXPECTED THROUGH THE EVENING
ACROSS NORTH-CENTRAL AND PERHAPS CENTRAL OKLAHOMA. MORE ISOLATED
STORMS STILL POSSIBLE FARTHER SOUTH AND WEST ALONG DRYLINE WHICH
WOULD AFFECT WESTERN OKLAHOMA/NORTH TEXAS.
STRONG MODEL AGREEMENT CONTINUES WITH POSSIBLY SIGNIFICANT SEVERE
WEATHER EVENT WEDNESDAY AFTERNOON AND LASTING WELL INTO THE
EVENING AND OVERNIGHT HOURS. STRONG S/WV TROUGH WILL MOVE INTO
CENTRAL PLAINS...AND WITH RESIDUAL BAROCLINIC ZONE AND RICH
MOISTURE IN PLACE...WE HAVE A SETUP FOR DAMAGING MCS EVENT.
GREATEST IMPACTS APPEAR TO BE AIMED FOR NORTHERN...CENTRAL...AND
EASTERN PORTIONS OF OKLAHOMA. WE WILL GO AHEAD AND INCLUDE
WORDING OF DAMAGING WIND AND HAIL IN GRIDS GIVEN RUN TO RUN
CONSISTENCY OF MODEL OUTPUT AND COLLABORATION/OUTLOOKS FROM SPC.
COLD FRONT WILL INTRODUCE DRIER AIR AND END TO SEVERE WEATHER
POTENTIAL BY LATE THURSDAY. WILL LEAVE SOME LOW POPS GOING FOR THE
FIRST HALF OF THURSDAY ACROSS MAINLY NORTHERN AND EASTERN PARTS OF
CWA WITH FROPA AND COLD TEMPS ALOFT. NEW INITIALIZATIONS WILL
YIELD DRY FORECAST AFTER THURSDAY WITH WARMING TREND AND RETURN TO
MODERATE SOUTHERLY WINDS OVER THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 90 70 88 64 / 20 50 30 70
HOBART OK 93 69 90 63 / 30 40 30 50
WICHITA FALLS TX 96 72 93 65 / 20 30 20 40
GAGE OK 91 65 82 61 / 30 30 30 60
PONCA CITY OK 90 65 82 60 / 30 60 30 80
DURANT OK 92 72 88 70 / 20 30 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
1147 AM CDT TUE MAY 29 2012
.UPDATE...
LOWERED RAIN CHANCES THIS AFTERNOON AND DELAYED THEM UNTIL
AFTER 4 PM CDT. ALSO...INCREASED HIGHS A FEW DEGREES.
&&
.DISCUSSION...
SOME SEVERE THUNDERSTORMS CAN BE EXPECTED LATE THIS
AFTERNOON AND EVENING.
THINK RAINFREE CONDITIONS WITH ABUNDANT SUN WILL PREVAIL
THROUGH 4 PM CDT TODAY. INCREASED HIGHS A FEW DEGREES WITH
MOST LOCATIONS IN THE 90S.
BELIEVE THE FIRST FEW STORMS WILL DEVELOP WILL OCCUR NEAR THE
KANSAS AND OKLAHOMA BORDER OR NEAR A DRYLINE SOMEWHERE NEAR A
WOODWARD TO ALTUS LINE BETWEEN 4 AND 7 PM CDT. LATEST HRRR AND
NAM12 HINTED AT THIS DEVELOPMENT. ANY STORMS WILL MOVE EAST OR
SOUTHEAST AND MAY ORGANIZE INTO A CLUSTER/MCS AFTER 7 PM CDT AND
AFFECT LOCATIONS MAINLY NORTHEAST OF A WOODWARD TO DURANT LINE.
THINK THE OKLAHOMA CITY METRO AREA WILL HAVE BEST SHOT FOR STORMS
BETWEEN 6 PM AND MIDNIGHT CDT.
REGARDING SEVERE POTENTIAL...WITH THE FIRST STORM DEVELOPMENT
BELIEVE LARGE...POTENTIALLY VERY LARGE HAIL...POSSIBLY GREATER
THAN TENNIS BALLS...WILL BE THE MAIN HAZARD DUE TO VERY UNSTABLE
AIR WITH 600 TO 900 J/KG BETWEEN -10 AND -30C. DAMAGING WINDS OVER
65 MPH IS ANOTHER HAZARD...ESPECIALLY IF STORMS CAN ORGANIZE INTO
A CLUSTER/LINE/MCS THIS EVENING. DUE TO FAIRLY HIGH CLOUD BASES
AND LACK OF STRONG LOW LEVEL SHEAR...THINK THE TORNADO THREAT
REMAINS LOW. BELIEVE SEVERE POTENTIAL WILL DIMINISH AFTER MIDNIGHT
CDT AS THE AIR BECOMES MORE STABLE.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 643 AM CDT TUE MAY 29 2012/
AVIATION...
29/12Z...VFR CONDITIONS EXPECTED TO PREVAIL UNTIL LATE THIS
AFTERNOON AND EVENING WHEN SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP ONCE AGAIN. GREATEST IMPACTS EXPECTED NEAR KPNC/KOKC/KOUN
TERMINALS...BUT WILL MENTION PROB30 ACROSS WESTERN OKLAHOMA
TERMINALS. MVFR/IFR RESTRICTIONS EXPECTED NEAR ANY STORMS.
DISCUSSION...
ANOTHER ROUND OF SEVERE WEATHER EXPECTED THIS AFTERNOON AND
EVENING. EXPECTATIONS OF CONVECTIVE INITIATION WILL BE FARTHER
NORTH THAN YESTERDAY...WITH INITIATION PROBABLE ACROSS FAR
NORTHERN OKLAHOMA OR SOUTHERN KANSAS. AN EAST AND SOUTHEAST
PROGRESSION AND UPSCALE GROWTH EXPECTED THROUGH THE EVENING
ACROSS NORTH-CENTRAL AND PERHAPS CENTRAL OKLAHOMA. MORE ISOLATED
STORMS STILL POSSIBLE FARTHER SOUTH AND WEST ALONG DRYLINE WHICH
WOULD AFFECT WESTERN OKLAHOMA/NORTH TEXAS.
STRONG MODEL AGREEMENT CONTINUES WITH POSSIBLY SIGNIFICANT SEVERE
WEATHER EVENT WEDNESDAY AFTERNOON AND LASTING WELL INTO THE
EVENING AND OVERNIGHT HOURS. STRONG S/WV TROUGH WILL MOVE INTO
CENTRAL PLAINS...AND WITH RESIDUAL BAROCLINIC ZONE AND RICH
MOISTURE IN PLACE...WE HAVE A SETUP FOR DAMAGING MCS EVENT.
GREATEST IMPACTS APPEAR TO BE AIMED FOR NORTHERN...CENTRAL...AND
EASTERN PORTIONS OF OKLAHOMA. WE WILL GO AHEAD AND INCLUDE
WORDING OF DAMAGING WIND AND HAIL IN GRIDS GIVEN RUN TO RUN
CONSISTENCY OF MODEL OUTPUT AND COLLABORATION/OUTLOOKS FROM SPC.
COLD FRONT WILL INTRODUCE DRIER AIR AND END TO SEVERE WEATHER
POTENTIAL BY LATE THURSDAY. WILL LEAVE SOME LOW POPS GOING FOR THE
FIRST HALF OF THURSDAY ACROSS MAINLY NORTHERN AND EASTERN PARTS OF
CWA WITH FROPA AND COLD TEMPS ALOFT. NEW INITIALIZATIONS WILL
YIELD DRY FORECAST AFTER THURSDAY WITH WARMING TREND AND RETURN TO
MODERATE SOUTHERLY WINDS OVER THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 90 70 88 64 / 20 50 30 70
HOBART OK 93 69 90 63 / 30 40 30 50
WICHITA FALLS TX 96 72 93 65 / 20 30 20 40
GAGE OK 91 65 82 61 / 30 30 30 60
PONCA CITY OK 90 65 82 60 / 30 60 30 80
DURANT OK 92 72 88 70 / 20 30 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1050 PM CDT WED MAY 30 2012
.DISCUSSION.../ISSUED AT 700 PM CDT/
WIDESPREAD RAIN CONTINUES TO TRACK EASTWARD ACROSS THE BULK OF THE
FORECAST AREA. HRRR AND NAM HAVE A DECENT GRASP ON THE FASTER TIMING
OF THIS WAVE AND ASSOCIATED PRECIPITATION SO HAVE LARGELY FOLLOWED
THESE MODELS FOR THE UPDATE. BUMPED UP POPS TO 100 PERCENT WITH THE
SWATH OF RAIN...WITH POPS DECREASING DRASTICALLY BEHIND THIS BAND AS
IT TRACKS EASTWARD. THE BULK OF THE PRECIPITATION SHOULD COME TO AN
END BY AROUND MIDNIGHT WITH SOUTH CENTRAL SD AREAS ALREADY LARGELY
DONE WITH RAIN. THESE DO MODELS HINT AT THE POTENTIAL SLOWING OF THE
MID LEVEL WAVE AFTER MIDNIGHT NEAR OUR EASTERN PERIMETER WHICH COULD
LEAVE SOME ISOLATED TO SCATTERED LIGHT RAIN SHOWERS OR SPRINKLES IN
ITS WAKE THROUGH AROUND MID MORNING THURSDAY. UPDATES ARE OUT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
WIDESPREAD SHOWERS QUICKLY WINDING DOWN. LIGHT RAIN OR SOME LIGHT
SPRINKLES BEHIND THE BAND OF RAIN WILL CONTINUE TO TRACK
SOUTHEASTWARD THROUGH THE EARLY MORNING HOURS AND WILL BRING SOME
MVFR CEILINGS WHICH SHOULD LIFT FROM WEST TO EAST THROUGH AROUND
14Z. VFR CONDITIONS WILL PREVAIL LATE THURSDAY MORNING THROUGH THE
END OF THE TAF PERIOD. NORTHERLY WINDS WILL INCREASE TO AROUND 10 TO
15 KT LATE TONIGHT BUT WILL BECOME LIGHT AND VARIABLE BY LATE
THURSDAY AFTERNOON WITH SURFACE HIGH PRESSURE TRACKING OVERHEAD.
&&
.PREV DISCUSSION.../ISSUED AT 310 PM CDT/
SHORT WAVE DROPPING SOUTHEAST FROM NORTHCENTRAL SOUTH DAKOTA WITH
WIDESPREAD RAIN OCCURRING ALONG AND EAST OF H85 TROF. SO WOULD
EXPECT THE AREAS ALONG AND EAST OF A HON-SUX LINE TO HAVE THE BEST
CHANCE FOR RAIN BEFORE 06Z AND THEN ACROSS NORTHWEST IOWA 06Z-12Z.
FURTHER WEST...CHANCE OF SHOWERS WILL PERSIST THROUGH 06Z AND WILL
END CHANCE OF RAIN THEREAFTER. COULD SEE AN ADDITIONAL HALF INCH OF
RAIN ACROSS THE EAST 00Z-06Z ON TOP OF WHAT OCCURS PRIOR TO 00Z. SO
SOME LOCALIZED AREAS COULD SEE AN INCH OF RAIN...BUT MOST AREAS WILL
SEE LESS. PLENTY OF CLOUD COVER WILL KEEP LOWS IN THE 40S WITH WINDS
GRADUALLY BECOMING NORTHEAST TO NORTH.
LIGHT RAIN CHANCE WILL LINGER EARLY THURSDAY MORNING FROM EAST TO
SOUTH OF FSD...MAINLY IN NORTHWEST IA...WITH ANY LIGHT RAIN
DECREASING STEADILY DURING THE MORNING. THIS REFLECTS THE CONTINUED
SPEEDUP BY MODELS OF THIS SYSTEM WHICH A DAY AGO WAS PROGGED TO DIG
A LOT MORE AND BE SLOWER. RETREATING OF THE WAVE SHOULD END THE
THREAT BY 18Z. CLEARING FROM THE NORTH AND WEST WILL BE GRADUAL BUT
STEADY WITH DRYING AT LOW LEVELS ALMOST MATCHING MID LEVEL DRYING.
WITH THE THINNING CLOUD COVER...TEMPERATURES WILL HAVE A CHANCE TO
WARM INTO THE 60S...THE COOLEST BEING OVER THE CLOUDY SOUTHEAST IN
NORTHWEST IOWA.
SECONDARY SHORT WAVE IS STILL DEPICTED TO DROP DOWN OVER AREA BEHIND
SYSTEM BY LATE FRIDAY AND WILL HAVE MENTION OF A FEW SHOWERS AND
THUNDERSTORMS INTO THE EVENING.
SATURDAY SHOULD BE A DRY AND WARMER DAY. THEN THE SUNDAY THROUGH
TUESDAY PERIOD SEEMS BOOKED TO BRING MODERATELY WARM AND KIND OF
HUMID WEATHER. MODELS UP TO TODAY HAVE BEEN FORECASTING RIDGING
ALOFT BEING FLATTENED BY ENSUING WEAK SHORT WAVES...HINTING AT A
PERIODIC FAIRLY LOW THREAT OF THUNDERSTORMS WILL GO WITH THIS
SOLUTION EXCEPT FOR CUTTING OUT MENTION FOR TUESDAY DAYTIME PERIOD.
BOTH GFS AND ECMWF RUNS TODAY SUGGEST MORE AMPLITUDE TO RIDGING AND
PERHAPS THUNDERSTORM THREAT BEING BELOW MENTION THRESHOLD VIA
CAPPING FOR THIS THREE DAY PERIOD. AS OUR CHANCES ARE PRETTY LOW
ANYWAY...WILL HOLD OFF ON TAKING ALL MENTIONS OF STORMS OUT IN CASE
MODELS GO BACK TO A FLATTER SOLUTION...GIVEN MOISTURE AND
INSTABILITY WILL IN ANY EVENT BE INCREASING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
700 PM CDT WED MAY 30 2012
.DISCUSSION.../ISSUED AT 700 PM CDT/
WIDESPREAD RAIN CONTINUES TO TRACK EASTWARD ACROSS THE BULK OF THE
FORECAST AREA. HRRR AND NAM HAVE A DECENT GRASP ON THE FASTER TIMING
OF THIS WAVE AND ASSOCIATED PRECIPITATION SO HAVE LARGELY FOLLOWED
THESE MODELS FOR THE UPDATE. BUMPED UP POPS TO 100 PERCENT WITH THE
SWATH OF RAIN...WITH POPS DECREASING DRASTICALLY BEHIND THIS BAND AS
IT TRACKS EASTWARD. THE BULK OF THE PRECIPITATION SHOULD COME TO AN
END BY AROUND MIDNIGHT WITH SOUTH CENTRAL SD AREAS ALREADY LARGELY
DONE WITH RAIN. THESE DO MODELS HINT AT THE POTENTIAL SLOWING OF THE
MID LEVEL WAVE AFTER MIDNIGHT NEAR OUR EASTERN PERIMETER WHICH COULD
LEAVE SOME ISOLATED TO SCATTERED LIGHT RAIN SHOWERS OR SPRINKLES IN
ITS WAKE THROUGH AROUND MID MORNING THURSDAY. UPDATES ARE OUT.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
WIDESPREAD SHOWERS WILL CONTINUE TO SPREAD EAST ACROSS THE AREA
THROUGH AROUND 06Z...AND WILL TAPER OFF FROM WEST TO EAST OVERNIGHT.
CEILINGS WILL DROP TO MVFR AFTER THROUGH 06Z...AND COULD HOVER THERE
OVERNIGHT. CEILINGS WILL GRADUALLY BECOME VFR FROM THE WEST AFTER
12Z. WINDS WILL BECOME MORE NORTHERLY OVERNIGHT AND WILL INCREASE TO
AROUND 10 TO 15 KT DURING THE DAYTIME.
&&
.PREV DISCUSSION.../ISSUED AT 310 PM CDT/
SHORT WAVE DROPPING SOUTHEAST FROM NORTHCENTRAL SOUTH DAKOTA WITH
WIDESPREAD RAIN OCCURRING ALONG AND EAST OF H85 TROF. SO WOULD
EXPECT THE AREAS ALONG AND EAST OF A HON-SUX LINE TO HAVE THE BEST
CHANCE FOR RAIN BEFORE 06Z AND THEN ACROSS NORTHWEST IOWA 06Z-12Z.
FURTHER WEST...CHANCE OF SHOWERS WILL PERSIST THROUGH 06Z AND WILL
END CHANCE OF RAIN THEREAFTER. COULD SEE AN ADDITIONAL HALF INCH OF
RAIN ACROSS THE EAST 00Z-06Z ON TOP OF WHAT OCCURS PRIOR TO 00Z. SO
SOME LOCALIZED AREAS COULD SEE AN INCH OF RAIN...BUT MOST AREAS WILL
SEE LESS. PLENTY OF CLOUD COVER WILL KEEP LOWS IN THE 40S WITH WINDS
GRADUALLY BECOMING NORTHEAST TO NORTH.
LIGHT RAIN CHANCE WILL LINGER EARLY THURSDAY MORNING FROM EAST TO
SOUTH OF FSD...MAINLY IN NORTHWEST IA...WITH ANY LIGHT RAIN
DECREASING STEADILY DURING THE MORNING. THIS REFLECTS THE CONTINUED
SPEEDUP BY MODELS OF THIS SYSTEM WHICH A DAY AGO WAS PROGGED TO DIG
A LOT MORE AND BE SLOWER. RETREATING OF THE WAVE SHOULD END THE
THREAT BY 18Z. CLEARING FROM THE NORTH AND WEST WILL BE GRADUAL BUT
STEADY WITH DRYING AT LOW LEVELS ALMOST MATCHING MID LEVEL DRYING.
WITH THE THINNING CLOUD COVER...TEMPERATURES WILL HAVE A CHANCE TO
WARM INTO THE 60S...THE COOLEST BEING OVER THE CLOUDY SOUTHEAST IN
NORTHWEST IOWA.
SECONDARY SHORT WAVE IS STILL DEPICTED TO DROP DOWN OVER AREA BEHIND
SYSTEM BY LATE FRIDAY AND WILL HAVE MENTION OF A FEW SHOWERS AND
THUNDERSTORMS INTO THE EVENING.
SATURDAY SHOULD BE A DRY AND WARMER DAY. THEN THE SUNDAY THROUGH
TUESDAY PERIOD SEEMS BOOKED TO BRING MODERATELY WARM AND KIND OF
HUMID WEATHER. MODELS UP TO TODAY HAVE BEEN FORECASTING RIDGING
ALOFT BEING FLATTENED BY ENSUING WEAK SHORT WAVES...HINTING AT A
PERIODIC FAIRLY LOW THREAT OF THUNDERSTORMS WILL GO WITH THIS
SOLUTION EXCEPT FOR CUTTING OUT MENTION FOR TUESDAY DAYTIME PERIOD.
BOTH GFS AND ECMWF RUNS TODAY SUGGEST MORE AMPLITUDE TO RIDGING AND
PERHAPS THUNDERSTORM THREAT BEING BELOW MENTION THRESHOLD VIA
CAPPING FOR THIS THREE DAY PERIOD. AS OUR CHANCES ARE PRETTY LOW
ANYWAY...WILL HOLD OFF ON TAKING ALL MENTIONS OF STORMS OUT IN CASE
MODELS GO BACK TO A FLATTER SOLUTION...GIVEN MOISTURE AND
INSTABILITY WILL IN ANY EVENT BE INCREASING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
706 PM CDT WED MAY 30 2012
.UPDATE...
LAPS CAP CONTINUES TO EXPAND THIS EVENING WHILE CAPES ARE ON THE
DOWNSWING. GIVEN THE ISC STATUS AND LATEST SHORT TERM QPF
EXPECTATIONS OVERNIGHT...WILL GO AHEAD AND SLASH POPS FOR ALL BUT
THE WESTERN QUARTER OF THE MID STATE. WILL KEEP 20 POPS GOING
ACROSS THE FAR WEST GIVEN THE SLIGHT MOISTURE ENHANCEMENT THAT IS
EXPECTED TOWARD 12Z FOR THAT AREA.
OTW...WILL INCREASE CLOUD COVERAGE ACROSS THE SOUTH FOR THIS
EVENING...GIVEN THE UPPER LEVEL BLOW OFF FROM THE WEAKENING STORMS
TO OUR SW. REMAINDER OF THE FORECAST...LOOKS TO BE IN GOOD SHAPE.
&&
.PREV DISCUSSION... /ISSUED 611 PM CDT WED MAY 30 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT OF SHWRS/TSTM 31/16Z-31/24Z.
EXPECT SCT AC/CI THRU 31/14Z WITH MVFR FOG POSSIBLE CSV PER LOW
LEVEL MOISTURE POOLING...CALM WINDS...AND CLRING SKIES. EXPECT
INCREASING UNSTABLE ATM TO SUPPORT SCT TO NUMEROUS SHWRS/TSTMS
BY 31/24Z...BUT WITH SOME UNCERTAINTIES PER LOCATION DEVELOPMENT
DUE TO DEVELOPMENT BEING MAINLY DIURNAL DRIVEN IN NATURE...THUS
WILL MENTION VCTS/CB REMARKS IN TAFS ONLY. EXPECT BKN VFR CB
BASED CEILINGS BY 31/24Z...BUT TEMP MVFR/IFR/LIFR CEILINGS POSSIBLE.
PREV DISCUSSION.../ISSUED 459 PM CDT WED MAY 30 2012/
UPDATE...
WRF...NAM AND GFS ARE ALL VIRTUALLY BONE DRY OVERNIGHT. RUC STILL
TRYING TO HANG ON TO CONVECTION WHICH HAS YET TO OCCUR. CURRENT
FCST IS IN THE 20-30 PERCENT RANGE. CONVECTION COULD STILL FIRE
BUT ITS LOOKING LESS AND LESS LIKELY.
THE PLAN FOR TONIGHT WILL BE TO GIVE THE CONVECTION CHANCES
ANOTHER HOUR OR TWO BEFORE WITHDRAWING THE OVERNIGHT POPS.
OVERNIGHT UPPER DIVERGENCE AND MOISTURE LEVELS ARE HELD AT
BAY. HOWEVER...MAY KEEP A SLIGHT CHANCE GOING ACROSS OUR SOUTHWEST AS PER
THE CURRENT PROXIMITY OF THIS AFTERNOONS CONVECTION.
OTW...QUIET NIGHT...ESPECIALLY COMPARED TO WHAT MAY BE TOMORROW AT
THIS TIME.
NO UPDATE AT THIS MOMENT...BUT LOOK FOR UPDATE WITH THE NEXT FEW HOURS.
PREV DISCUSSION... /ISSUED 311 PM CDT WED MAY 30 2012/
DISCUSSION...
AIR MASS SOMEWHAT STABLE THIS AFTERNOON ACROSS THE TENNESSEE
VALLEY WITH TEMPS IN THE 80S. DRIER AIR ALOFT HAS MIXED DOWN TO
THE SURFACE. WILL HAVE SMALL POPS IN FOR TONIGHT BUT THINK WE WILL
HAVE TO WAIT ON BOUNDARY TO OUR SOUTH TO LIFT NORTHWARD INTO
TENNESSEE THURSDAY MORNING TO PROVIDE FOCUS. EXPECT WE WILL SEE
SHOWERS AND STORMS ON THE INCREASE THURSDAY ESPECIALLY BY
AFTERNOON IN MOST AREAS. SHOWERS AND STORMS LOOK CATEGORICAL
THURSDAY NIGHT...ESPECIALLY EVENING. SOME STORMS COULD BE SEVERE
IN THE MID STATE LATE AFTERNOON AND THURSDAY EVENING AS SURFACE
LOW UNDERGOES CYCLOGENSIS AS IT ROLLS EAST FROM OKLAHOMA ON
THURSDAY AND INTO THE TENNESSEE AND OHIO VALLEYS BY LATE IN THE
DAY THURSDAY. WIND PROFILES WOULD SUGGEST DAMAGING WINDS AND LARGE
HAIL TO BE THE MAIN THREAT. RAIN SHOULD END FROM THE WEST FRIDAY
MORNING WITH HIGH PRESSURE WORKING INTO THE AREA FROM MISSOURI. A
DIRTY SURFACE RIDGE WILL BE OVER THE TENNESSEE VALLEY FOR THE NEXT
SEVERAL DAYS AS UPPER TROUGH RULES...WITH NO SIGNIFICANT RAIN
CHANCE UNTIL ABOUT TUESDAY OF NEXT WEEK AND THEN MODELS HAVE
FAIRLY LOW QPF.
AND NOW A LITTLE TRIVIA: NASHVILLE IS ON PACE TO HAVE THE 6TH
WARMEST MAY ON RECORD AND THE WARMEST SINCE 1991. NASHVILLE HAD
TWO DAYS OF 95 DEGREE HEAT THIS MONTH. THE HOTTEST TEMPERATURE
EVER RECORDED IN THE MONTH OF MAY IS 96 BACK IN 1937.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
611 PM CDT WED MAY 30 2012
.UPDATE...FOR 00Z AVIATION DISCUSSION.
&&
.AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT OF SHWRS/TSTM 31/16Z-31/24Z.
EXPECT SCT AC/CI THRU 31/14Z WITH MVFR FOG POSSIBLE CSV PER LOW
LEVEL MOISTURE POOLING...CALM WINDS...AND CLRING SKIES. EXPECT
INCREASING UNSTABLE ATM TO SUPPORT SCT TO NUMEROUS SHWRS/TSTMS
BY 31/24Z...BUT WITH SOME UNCERTAINTIES PER LOCATION DEVELOPMENT
DUE TO DEVELOPMENT BEING MAINLY DIURNAL DRIVEN IN NATURE...THUS
WILL MENTION VCTS/CB REMARKS IN TAFS ONLY. EXPECT BKN VFR CB
BASED CEILINGS BY 31/24Z...BUT TEMP MVFR/IFR/LIFR CEILINGS POSSIBLE.
&&
.PREV DISCUSSION.../ISSUED 459 PM CDT WED MAY 30 2012/
UPDATE...
WRF...NAM AND GFS ARE ALL VIRTUALLY BONE DRY OVERNIGHT. RUC STILL
TRYING TO HANG ON TO CONVECTION WHICH HAS YET TO OCCUR. CURRENT
FCST IS IN THE 20-30 PERCENT RANGE. CONVECTION COULD STILL FIRE
BUT ITS LOOKING LESS AND LESS LIKELY.
THE PLAN FOR TONIGHT WILL BE TO GIVE THE CONVECTION CHANCES
ANOTHER HOUR OR TWO BEFORE WITHDRAWING THE OVERNIGHT POPS.
OVERNIGHT UPPER DIVERGENCE AND MOISTURE LEVELS ARE HELD AT
BAY. HOWEVER...MAY KEEP A SLIGHT CHANCE GOING ACROSS OUR SOUTHWEST AS PER
THE CURRENT PROXIMITY OF THIS AFTERNOONS CONVECTION.
OTW...QUIET NIGHT...ESPECIALLY COMPARED TO WHAT MAY BE TOMORROW AT
THIS TIME.
NO UPDATE AT THIS MOMENT...BUT LOOK FOR UPDATE WITH THE NEXT FEW HOURS.
PREV DISCUSSION... /ISSUED 311 PM CDT WED MAY 30 2012/
DISCUSSION...
AIR MASS SOMEWHAT STABLE THIS AFTERNOON ACROSS THE TENNESSEE
VALLEY WITH TEMPS IN THE 80S. DRIER AIR ALOFT HAS MIXED DOWN TO
THE SURFACE. WILL HAVE SMALL POPS IN FOR TONIGHT BUT THINK WE WILL
HAVE TO WAIT ON BOUNDARY TO OUR SOUTH TO LIFT NORTHWARD INTO
TENNESSEE THURSDAY MORNING TO PROVIDE FOCUS. EXPECT WE WILL SEE
SHOWERS AND STORMS ON THE INCREASE THURSDAY ESPECIALLY BY
AFTERNOON IN MOST AREAS. SHOWERS AND STORMS LOOK CATEGORICAL
THURSDAY NIGHT...ESPECIALLY EVENING. SOME STORMS COULD BE SEVERE
IN THE MID STATE LATE AFTERNOON AND THURSDAY EVENING AS SURFACE
LOW UNDERGOES CYCLOGENSIS AS IT ROLLS EAST FROM OKLAHOMA ON
THURSDAY AND INTO THE TENNESSEE AND OHIO VALLEYS BY LATE IN THE
DAY THURSDAY. WIND PROFILES WOULD SUGGEST DAMAGING WINDS AND LARGE
HAIL TO BE THE MAIN THREAT. RAIN SHOULD END FROM THE WEST FRIDAY
MORNING WITH HIGH PRESSURE WORKING INTO THE AREA FROM MISSOURI. A
DIRTY SURFACE RIDGE WILL BE OVER THE TENNESSEE VALLEY FOR THE NEXT
SEVERAL DAYS AS UPPER TROUGH RULES...WITH NO SIGNIFICANT RAIN
CHANCE UNTIL ABOUT TUESDAY OF NEXT WEEK AND THEN MODELS HAVE
FAIRLY LOW QPF.
AND NOW A LITTLE TRIVIA: NASHVILLE IS ON PACE TO HAVE THE 6TH
WARMEST MAY ON RECORD AND THE WARMEST SINCE 1991. NASHVILLE HAD
TWO DAYS OF 95 DEGREE HEAT THIS MONTH. THE HOTTEST TEMPERATURE
EVER RECORDED IN THE MONTH OF MAY IS 96 BACK IN 1937.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1259 PM CDT TUE MAY 29 2012
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
LINE OF TSRA/SHRA IS CURRENTLY PASSING NEAR CSV...BUT ATMOSPHERE
HAS STABILIZED SOMEWHAT TO THE WEST OF THE LINE AS SHOWN BY WATER
VAPOR IMAGERY. LATEST HRRR RUNS INDICATE AN ADDITIONAL LINE OF
SHOWERS/STORMS WILL FORM ALONG WEAK COLD FRONT LOCATED OVER THE
PAH CWA AND MOVE INTO THE MID STATE LATER THIS AFTERNOON. HAVE
ADJUSTED TIMING OF VCSH AND TEMPO TSRA BASED ON THE LATEST
GUIDANCE. ALL ACTIVITY EXPECTED TO DIMINISH LATE THIS EVENING
WITH PATCHY MVFR/IFR FOG OVERNIGHT AT CKV/CSV.
&&
.PREV DISCUSSION... /ISSUED 926 AM CDT TUE MAY 29 2012/
UPDATE...EARLY MORNING PRE FRONTAL STORMS HAVE BEEN TRACKING OVER
OUR WESTERN COUNTIES WITH ISOLATED WIND GUSTS AND POCKETS OF
LOCALLY HEAVY RAINFALL...ESPECIALLY OVER BENTON COUNTY. THE
OVERALL INTENSITY AND COVERAGE OF STORMS IS EXPECTED TO DECREASE
THROUGH LATE MORNING. ADDITIONAL SCATTERED STORMS MAY DEVELOP
FARTHER EAST ALONG THE OUTFLOW. AS WE GO INTO THE
AFTERNOON...STORMS WILL INCREASE IN COVERAGE AND INTENSITY
AGAIN...ESPECIALLY FOR AREAS ALONG AND EAST OF I 65. SHORT RANGE
MODELS INDICATE MU CAPES >2500 J/KG WITH STEEPENING MID LEVEL
LAPSE RATES AND HEIGHTS FALLS. WE COULD SEE MORE STORMS WITH
LOCALIZED BRIEF SEVERE WIND GUSTS...AND VERY HEAVY DOWNPOURS
THANKS TO COPIOUS MOISTURE AND RELATIVELY SLOW STORM MOVEMENT.
THUNDERSTORM ACTIVITY MAY LINGER WELL INTO THE EVENING...
ESPECIALLY SOUTH...AS FRONTAL MOVEMENT BECOMES SLUGGISH AND TAKES
ON AN E TO W ORIENTATION.
13
PREV DISCUSSION... /ISSUED 312 AM CDT TUE MAY 29 2012/
DISCUSSION...FRONTAL SYSTEM NEAR ST LOUIS IS MOVING SEWD TOWARD
THE AREA. AT THE SAME TIME...MOISTURE ASSOCIATED WITH BERYL IS
INCREASING OVER EAST TN. THE INCREASED COLUMN MOISTURE AND THE
PRESENCE OF THE FRONT WILL PUSH POPS INTO THE CHANCE CATEGORY FOR
TODAY. LOCAL WRF BRINGS MOISTURE ASSOCIATED WITH THE FRONT INTO
STEWART COUNTY BY LATE MORNING AS MOISTURE ASSOCIATED WITH BERYL
BUILDS UP OVER EAST TN AND THE CUMBERLAND PLATEAU.
FRONT PUSHES THROUGH THE MIDSTATE...GOING QUASI-STATIONARY JUST TO
THE SOUTH OF THE AREA BY LATE TONIGHT. POPS DIMINISH TONIGHT AS
MID LEVEL DRY AIR PUSHES INTO THE AREA. NOT MUCH HAPPENING ON WED
UNTIL DRY AIR GETS PUSHED OUT OF THE AREA AND THE FRONT TO THE
SOUTH MOVES BACK NORTH DRIFTS BACK NORTH BY THU AM.
BY THU AM A VIGOROUS H5 WAVE DROPS INTO THE PLAINS...SPINNING UP A
MAJOR SFC LOW IN THE LOWER PLAINS. THE SFC LOW PUSHES NEWD INTO
THE MID MS/OH/TN VALLEYS BY LATE THU. OF COURSE...THIS INCREASES
POPS SIGNIFICANTLY FOR THU THROUGH FRI AM. AT THIS POINT THE GFS
AND ECM DIVERGE A BIT. THE ECM MOVES THE SYSTEM FASTER EAST ON THU
NGT AND FRI WITH COLD AIR COMING IN FASTER ON THE ECM COMPARED TO
THE GFS. HAVE STRUCK COMPROMISES ON POPS AND TEMPS TO BRIDGE THESE
DIFFERENCES.
THERE WAS SOME INDICATION OF POST FRONTAL SHOWERS ON BOTH MODELS
BUT LOCATION AND TIMING WAS RATHER DIFFICULT TO DETERMINE AND HAVE
THUS LEFT SUN AND MON DRY.
AS FAR AS WX THREATS GO...THE DAY 3 OUTLOOK FOR THU/THU NGT HAS A SLIGHT
RISK FOR SVR TSTMS. HPC HAS ABOUT 1-2 INCHES OF RAINFALL FOR THEIR 5
DAY TOTALS FOR THIS WEEK(MON-FRI) WITH THE HEAVIEST RAINFALL
RESERVED FOR THE OH VALLEY AREA.
WELL I GUESS THE GOOD NEWS IS THAT WE`LL GET A COUPLE OF
DAYS (FRI-SAT) OF AT OR BELOW NORMAL TEMPS BEFORE THE HEAT COMES
BACK. MAY WILL WIND UP WELL ABOVE NORMAL TEMPERATURE WISE...THE
SEVENTH MONTH IN A ROW.
JLM
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS MIAMI FL
201 AM EDT THU MAY 31 2012
.AVIATION...
A LIGHT WESTERLY TO SOUTHWESTERLY FLOW WILL PREVAIL ACROSS ALL
TERMINALS THROUGH THE EARLY MORNING HOURS WITH THE EAST COAST
TERMINALS HAVING PERIODS WITH VARIABLE WINDS OR NEAR CALM. MAINLY
VFR CONDITIONS EXPECTED TO PREVAIL ACROSS ALL TERMINALS THROUGH THE
MORNING HOURS. A SURGE OF TROPICAL MOISTURE IS MOVING NORTHWARD
INTO THE REGION WITH CONVECTION EXPECTED ACROSS SOUTH FLORIDA BY
LATE MORNING AND THE AFTERNOON. SHOWERS AND THUNDERSTORMS MAINLY
EXPECTED IN VICINITY OF EAST COAST TERMINALS. A SSE SEA BREEZE IS
POSSIBLE FOR EAST COAST TERMINALS AROUND 17-20Z BUT WINDS COULD
REMAIN SSW AT TERMINALS KTMB AND KOPF IF SEA BREEZE DOES NOT
PENETRATE THAT FAR INLAND. WITH AFTERNOON AND EVENING CONVECTION
PERIODS OF SUB-VFR TO BRIEF PERIODS OF IFR CONDITIONS POSSIBLE
WITH SHOWERS/THUNDERSTORMS MAINLY EAST COAST TERMINALS.
60
&&
.PREV DISCUSSION... /ISSUED 638 PM EDT WED MAY 30 2012/
AVIATION...AS REMNANTS OF BERYL MOV NE ALG THE SE U.S. COAST...A
RDG OF SFC HI PRES...XTNDG W FM THE SW N ATLC OVR THE LWR FLA
STRAITS AND N CUBA INTO THE SE GULF OF MEX...SLOLY MOVS N AND OVR S
FLA AFT 31/12Z. AS THE RDG MOVS N...DEEP TROPICAL MOISTURE OVR THE
SW CARIB IS PULLED NORTHWARD. BUT...VFR XPCTD ALL TERMINALS THRU
31/18Z THOUGH SOME SHRA/PSBL ISOLD TSRA PSBL W COAST AND PSBLY
AFFECTING KAPF OVRNITE. XPCT INCRSD SHRA/TSRA ACTIVITY E COAST AFT
31/18Z AS WNDS ALOFT SW-W AND ACTIVITY WL MOV FM THE INTERIOR AND
THE E COAST DURG THE AFTN HRS. ATTM HAV ONLY VCTS IN E COAST TAFS
SEEING PSBLTY 18 HRS OUT. SFC WNDS BCMG SW AND LESS THAN 10 KTS ALL
TERMINALS THRU 18Z BUT E COAST SEA BRZE SE-SSE ARND 10 KTS TO DVLP.
PREV DISCUSSION... /ISSUED 229 PM EDT WED MAY 30 2012/
SHORT TERM (TONIGHT-FRIDAY NIGHT)...
THE LATEST NUMERICAL GUIDANCE HAS INITIALIZED WELL WITH THE
CURRENT SYNOPTIC PATTERN AND GENERALLY REMAINS IN GOOD AGREEMENT
THROUGH THE SHORT-TERM PERIOD. DESPITE THE DRIER AIR IN PLACE ACROSS
MUCH OF THE LOCAL AREA...SCATTERED AFTERNOON SHOWERS AND STORMS ARE
EXPECTED TO DEVELOP ACROSS THE EASTERN HALF OF THE LOCAL AREA
THROUGH THE EARLY EVENING PERIOD TODAY...MAINLY ACROSS THE LAKE AND
EAST COAST AREAS. THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL
WITH THIS PATTERN CONTINUING THROUGH THE MID-EVENING HOURS BEFORE
TRENDING DOWN THROUGH THE OVERNIGHT PERIOD TONIGHT AND INDICATES THE
BEST COVERAGE REMAINING OVER THE EASTERN AREAS NORTH OF FORT
LAUDERDALE TO THE LAKE ACROSS PALM BEACH COUNTY.
THURSDAY THROUGH FRIDAY...THE MODELS CONTINUE TO INDICATE PLENTY OF
DEEP LAYER MOISTURE SPREADING NORTH ACROSS THE KEYS INTO SOUTH
FLORIDA...WHICH HAS BEEN A PERSISTENT FEATURE OVER THE PAST COUPLE
OF DAYS FROM EACH RUN. THIS INCREASE IN DEEP LAYER MOISTURE COMBINED
WITH SOUTHWEST FLOW ALOFT AHEAD OF AN UPPER TROUGH WILL KEEP THE
RAINFALL CHANCES ELEVATED. MODEL PWAT VALUES REFLECT THIS PATTERN
AND INDICATE VALUES AROUND AND EVEN ABOVE THE TWO INCH MARK. AT THIS
TIME...TOTAL RAINFALL ACCUMULATIONS THROUGH THIS PERIOD ARE FORECAST
TO RANGE FROM 1 TO 3 INCHES NORTH OF ALLIGATOR ALLEY TO 2 TO 4
INCHES SOUTH OF ALLIGATOR ALLEY. AS TYPICALLY OBSERVED DURING THESE
EVENTS...LOCALLY HIGHER AMOUNTS WILL CERTAINLY BECOME A POSSIBILITY
WHERE THE HEAVIER ACTIVITY BECOMES CONCENTRATED. INTERESTS ARE
ENCOURAGED TO MONITOR LATER FORECASTS FOR UPDATES THROUGH THIS TIME.
AS CONFIDENCE CONTINUES TO INCREASE...A FLOOD WATCH MAY BECOME
NECESSARY.
LONG TERM (SATURDAY-TUESDAY)...
THE UPPER TROUGH IS PROGGED TO LIFT NORTHEAST ALLOWING UPPER HEIGHTS
ACROSS THE REGION TO GRADUALLY RISE. THIS COMBINED WITH MUCH DRIER
MID/UPPER LEVEL AIR SPREADING INTO THE AREA WILL LIKELY LIMIT THE
DAILY RAINFALL COVERAGE TO A MORE TYPICAL PATTERN EACH DAY.
MARINE...
LIGHT TO MODERATE SOUTH AND SOUTHWEST WINDS WILL BE EXPECTED
THROUGH THE MID-WEEK PERIOD WITH ISOLATED SHOWERS AND STORMS
REMAINING POSSIBLE EACH DAY. LATE MORNING AND AFTERNOON SEA
BREEZES WILL TRANSLATE TO CHOPPIER CONDITIONS EACH DAY...MAINLY
NEAR THE COAST.
AVIATION...
DRIER AIR HAS WORKED INTO SOUTH FLORIDA FROM THE GULF OF MEXICO
THIS MORNING...AND SHOULD REMAIN OVER SOUTH FLORIDA THROUGH REST
OF TODAY INTO TONIGHT. AT THE SAME TIME...THE EAST COAST SEA
BREEZE WILL DEVELOP AND PUSH SLOWLY INLAND THROUGH THE AFTERNOON
HOURS AND SHOULD STALL BETWEEN KMIA...KFLL...AND KTMB TAF SITES.
THIS MEANS THAT THE MOST OF THE EAST COAST TAF SITES SHOULD BECOME
SOUTHEAST BETWEEN 20Z AND 21Z TODAY...EXCEPT FOR KFXE AND KTMB
WHERE THEY WILL REMAIN SOUTHWEST. THE SPEEDS WILL ALSO BE AT 5 TO
10 KNOTS FOR REST OF THIS AFTERNOON.
THE WINDS WILL THEN SWING BACK TO A SOUTHWEST DIRECTION AFTER 00Z
TONIGHT INTO THURSDAY MORNING WITH SPEEDS AT 5 KNOTS OR LESS ALONG
THE EAST COAST TAF SITES. AT KAPF TAF SITE...THE WINDS WILL REMAIN
SOUTHWEST DIRECTION AT 5 T0 10 KNOTS EXCEPT LESS THAN 5 KNOTS TONIGHT.
THERE COULD BE SOME ISOLATED SHOWERS THIS AFTERNOON OVER MOST OF
THE TAF SITES BEFORE GOING DRY TONIGHT. THE ONLY EXCEPTION IS FOR
KPBI WHERE THERE COULD BE SOME THUNDERSTORMS THIS AFTERNOON. SO
WILL SHOW VCSH FOR ALL TAF SITES UNTIL 00Z TONIGHT...EXCEPT VCTS
FOR KPBI.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 73 83 73 / 30 30 60 50
FORT LAUDERDALE 88 74 84 77 / 40 30 60 50
MIAMI 89 74 85 76 / 50 30 60 50
NAPLES 89 74 83 74 / 40 30 60 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 AM CDT THU MAY 31 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
//PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PRECIPITATION TIMING AND IMPACTS TO FLIGHT CATEGORY.
* STRONG GUSTY WINDS THURSDAY AFTERNOON. BMD
//DISCUSSION...UPDATED 06Z...
SHOWERS ARE BEGINNING TO MOVE INTO NORTHERN ILLINOIS AHEAD OF UPPER
LOW TRACKING ACROSS NORTHERN IOWA. INITIAL ROUND OF SHOWERS IS
ENCOUNTERING DRY AIR LEADING TO SOME EROSION ALONG THE LEADING EDGE.
AS THE ATMOSPHERE GRADUALLY SATURATES...EXPECT COVERAGE TO INCREASE
ESPECIALLY AFTER AROUND 08Z FOR ROCKFORD AND 10Z FOR THE CHICAGO
AREA. WINDS ARE EXPECTED TO STAY OUT OF THE NORTHEAST MUCH OF THE
DAY THURSDAY...WITH GUSTS INTO THE MID TO UPPER TEENS EARLY IN THE
DAY INCREASING TO ABOVE 20 KT IN THE AFTERNOON. CIGS WILL GRADUALLY
DROP DURING THIS TIME...BUT CONFIDENCE IS NOT HIGH AT THIS POINT AS
TO HOW LOW. NAM MODEL SOUNDINGS AND MOS GUIDANCE INDICATE THAT CIGS
WILL DROP TO IFR...THOUGH GFS/MAV IS A BIT MORE RESERVED KEEPING
THINGS MVFR OR BETTER. GIVEN THE NAMS TENDENCY TO OVERDO LOW LEVEL
MOISTURE...WILL KEEP FLIGHT CATEGORY ABOVE IFR FOR NOW...BUT WILL
HAVE TO MONITOR TRENDS FOR POSSIBLY LOWER CONDITIONS. SHOWERS MAY
LINGER INTO FRIDAY MORNING WHEN THE SURFACE LOW IS PROGGED TO PULL
AWAY FROM THE REGION TAKING SHOWERS ALONG WITH IT. WINDS WILL SHIFT
BACK TO THE NNW IN THE WAKE OF THE SURFACE LOW EARLY FRIDAY MORNING
AND SHOULD THEN SEE GRADUALLY IMPROVING CONDITIONS. BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN OVERSPREADING THE TERMINALS
TONIGHT...LOW CONFIDENCE ON TIMING.
* MEDIUM TO HIGH CONFIDENCE IN CIGS DROPPING TO AT LEAST MVFR. LOW
CONFIDENCE ON CIGS DROPPING INTO IFR CATEGORY.
* MEDIUM CONFIDENCE ON WINDSPEEDS THURSDAY. BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
253 AM CDT
A POTENT LOW PRESSURE SYSTEM WILL APPROACH THE GREAT LAKES TODAY
WITH NORTHEASTERLY WINDS INCREASING TO NEAR 30 KT LATER TODAY
ACROSS THE SOUTHERN HALF OF LAKE MICHIGAN. WILL EXPAND THE SMALL
CRAFT ADVISORY TO INCLUDE THE ILLINOIS NEARSHORE WATERS BEGINNING
THIS AFTERNOON. AS THE LOW LIFTS NORTHEAST TO NEAR OHIO
TONIGHT...WINDS WILL BEGIN TO BACK TO THE NORTH...AND MAINTAIN
THEIR 30 KT MAGNITUDE WITH WAVES ACROSS THE FAR SOUTHERN PART OF
THE LAKE EXPECTED TO GROW INTO THE 7 TO 10 FT RANGE. THE LOW WILL
SLOWLY LIFT NORTH TOWARDS ONTARIO FRIDAY...BUT THE TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE OVER LAKE MICHIGAN WITH WINDS
CONTINUING TO BACK TO THE NORTHWEST. WINDS AND WAVES SHOULD
FINALLY BEGIN TO TAPER SATURDAY NIGHT INTO SUNDAY AS THE LOW
BEGINS TO DEPART TO THE EAST. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 AM CDT THU MAY 31 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
//PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PRECIPITATION TIMING AND IMPACTS TO FLIGHT CATEGORY.
* STRONG GUSTY WINDS THURSDAY AFTERNOON. BMD
//DISCUSSION...UPDATED 06Z...
SHOWERS ARE BEGINNING TO MOVE INTO NORTHERN ILLINOIS AHEAD OF UPPER
LOW TRACKING ACROSS NORTHERN IOWA. INITIAL ROUND OF SHOWERS IS
ENCOUNTERING DRY AIR LEADING TO SOME EROSION ALONG THE LEADING EDGE.
AS THE ATMOSPHERE GRADUALLY SATURATES...EXPECT COVERAGE TO INCREASE
ESPECIALLY AFTER AROUND 08Z FOR ROCKFORD AND 10Z FOR THE CHICAGO
AREA. WINDS ARE EXPECTED TO STAY OUT OF THE NORTHEAST MUCH OF THE
DAY THURSDAY...WITH GUSTS INTO THE MID TO UPPER TEENS EARLY IN THE
DAY INCREASING TO ABOVE 20 KT IN THE AFTERNOON. CIGS WILL GRADUALLY
DROP DURING THIS TIME...BUT CONFIDENCE IS NOT HIGH AT THIS POINT AS
TO HOW LOW. NAM MODEL SOUNDINGS AND MOS GUIDANCE INDICATE THAT CIGS
WILL DROP TO IFR...THOUGH GFS/MAV IS A BIT MORE RESERVED KEEPING
THINGS MVFR OR BETTER. GIVEN THE NAMS TENDENCY TO OVERDO LOW LEVEL
MOISTURE...WILL KEEP FLIGHT CATEGORY ABOVE IFR FOR NOW...BUT WILL
HAVE TO MONITOR TRENDS FOR POSSIBLY LOWER CONDITIONS. SHOWERS MAY
LINGER INTO FRIDAY MORNING WHEN THE SURFACE LOW IS PROGGED TO PULL
AWAY FROM THE REGION TAKING SHOWERS ALONG WITH IT. WINDS WILL SHIFT
BACK TO THE NNW IN THE WAKE OF THE SURFACE LOW EARLY FRIDAY MORNING
AND SHOULD THEN SEE GRADUALLY IMPROVING CONDITIONS. BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN OVERSPREADING THE TERMINALS
TONIGHT...LOW CONFIDENCE ON TIMING.
* MEDIUM TO HIGH CONFIDENCE IN CIGS DROPPING TO AT LEAST MVFR. LOW
CONFIDENCE ON CIGS DROPPING INTO IFR CATEGORY.
* MEDIUM CONFIDENCE ON WINDSPEEDS THURSDAY. BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
411 PM CDT
LARGE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS AND THE
UPPER MIDWEST GRADUALLY EXPANDS EASTWARD ACROSS THE GREAT LAKES
TONIGHT AND THURSDAY ALLOWING WINDS TO DIMINISH...AT LEAST
TEMPORARILY. AS LOW PRESSURE LIFTS NORTHEAST AND DEEPENS IS IT
CROSSES THE MID MISSISSIPPI VALLEY THURSDAY AFTERNOON THE
PRESSURE GRADIENT BETWEEN THE RIDGE ACROSS THE GREAT LAKES AND THE
APPROACHING LOW WILL BE ON THE INCREASE AND WILL CONTINUE TO
INCREASE THURSDAY NIGHT AS THE LOW MOVES TO NEAR WESTERN LAKE ERIE
BY FRIDAY MORNING. WINDS WILL RESPOND TO THE TIGHTENING PRESSURE
GRADIENT BY INCREASING OUT OF THE NORTH AND NORTHEAST...ESPECIALLY
ON THE SOUTH PORTION OF THE LAKE. WINDS WILL GRADUALLY BACK AND
SLACKEN LATER FRIDAY AND FRIDAY NIGHT AS THE LOW MOVES NORTH INTO
ONTARIO.
WIND AND WAVE CONDITIONS REQUIRING A SMALL CRAFT ADVISORY ARE
LIKELY FOR THE SOUTHERN PORTION OF THE ILLINOIS WATERS AND ALL OF
THE INDIANA WATERS FROM THURSDAY AFTERNOON UNTIL LATE FRIDAY.
HAZARDOUS CONDITIONS FOR SMALL CRAFT AREA ALSO LIKELY FOR THE
NORTHERN PORTION OF THE ILLINOIS WATERS THURSDAY NIGHT INTO
FRIDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1226 AM CDT THU MAY 31 2012
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 120 PM CDT WED MAY 30 2012
THE HRRR AND RAP MODELS HAVE SHOWN A PERSISTENT CONVECTIVE
INITIATION SIGNAL ACROSS WEST CENTRAL OR SOUTHWEST KANSAS...ROUGHLY
IN AN AREA BOUNDED BY KALVESTA-GOVE-NESS CITY-KALVESTA...BY 20 TO
21Z. THIS WOULD SEEM TO MATCH THE LOCATION OF WHERE THE BOUNDARY
IS...ALTHOUGH IS A BIT FARTHER SOUTH. IT WOULD SEEM THE BEST AREA
FOR CONVECTIVE INITIATION WOULD BE JUST NORTH OF WHERE THE LATEST
HRRR RUNS HAVE IT...BUT EITHER WAY CONVECTIVE INITIATION SHOULD
OCCUR BY NO LATER THAN 22Z NORTH OF HIGHWAY 50 AND ALONG/SOUTH OF
INTERSTATE 70 IN SOUTHWEST/WEST-CENTRAL KANSAS. THE EARLY STAGE OF
CONVECTIVE MODE SHOULD BE SUPERCELLULAR WITH SURFACE-BASED CAPE
CONTINUING TO INCREASE ABOVE 3000 J/KG AND A SUBSTANTIAL AMOUNT OF
DEEP LAYER SHEAR TO SUPPORT VIGOROUS SUPERCELL THUNDERSTORMS.
SUPERCELL STORM MOTION WILL BE SOUTHEAST AT AROUND 20 TO 25 KNOTS
(NON SUPERCELL STORM MOTION BEING MORE EASTERLY). THE STORM
PREDICTION CENTER (SPC) PROBABILISTIC HAIL AND WIND ARE VERY HIGH
ACROSS MUCH OF THE DDC FORECAST AREA...INCLUDING ALL POINTS SOUTH OF
HIGHWAY 4 AND EAST OF HIGHWAY 83. THE SPC PROBABILISTIC SEVERE
WEATHER THREATS LOOK PRETTY GOOD AND AGREE ON JUST ABOUT ALL
ACCOUNTS. THE ONLY THING I QUESTION IS THE TORNADO POTENTIAL...AS
CONVECTIVE MODE AFTER A FEW HOURS MAY TRANSITION MORE TO A
QUASI-LINEAR SIGNIFICANT SEVERE EPISODE (DAMAGING TO DESTRUCTIVE
WIND POTENTIAL 80+ MPH). THIS MAY NOT OCCUR UNTIL LATER THIS
EVENING AS THE SEVERE WEATHER EVENT SHIFTS INTO OKLAHOMA. IF THE
SUPERCELL PHASE CAN LAST SEVERAL HOURS THEN THE TORNADO POTENTIAL
WILL DEFINITELY BE ENHANCED...AND FOR THAT REASON THE 10 PERCENT
TORNADO POTENTIAL (PROB OF A TORNADO WITHIN 25 MILES OF A POINT)
DOES LOOK JUSTIFIED FOR AREAS GENERALLY SOUTHEAST OF A LIBERAL TO
JETMORE TO LARNED LINE. DURING THE EVENING HOURS...THE SEVERE
WEATHER THREAT WILL DIMINISH FROM NORTH TO SOUTH AS THE MAIN AREA
SHIFTS INTO NORTHERN OKLAHOMA...HOWEVER WILL MAINTAIN SOME 20-50
POPS IN THE SOUTHEAST HALF OF THE FORECAST AREA THROUGH THE 06-09Z
TIME FRAME AS ADDITIONAL STORMS MAY DEVELOP IN THE WAKE OF THE
PRIMARY ROUND. ANYTHING DEVELOPING AFTER THE PRIMARY ROUND WILL
HAVE MUCH LESS INSTABILITY TO WORK WITH AND THE SEVERE WEATHER
THREAT SHOULD BE RATHER LOW.
THE REST OF THE FORECAST FOR LATE TONIGHT AND TOMORROW WAS
ESSENTIALLY UNCHANGED AS SUBSIDENCE AND DRIER AIR MOVES IN ON
NORTHEAST WINDS. TEMPERATURES WILL STRUGGLE TO ESCAPE THE LOWER 70S
OVER MUCH OF SOUTHWEST KANSAS ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 256 PM CDT WED MAY 30 2012
AFTER THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION
PASSES TO THE EAST, SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN
KANSAS THURSDAY AND THURSDAY NIGHT. THURSDAY WILL BE COOLER BEHIND
THE FRONT WITH HIGHS IN THE 70S. THURSDAY NIGHT`S LOWS WILL BE FAIRLY
CHILLY IN THE 40S AS SKIES REMAIN PARTLY CLOUDY WITH FAIRLY LIGHT
SOUTHERLY WINDS. HOWEVER, IF THERE ARE MORE CLOUDS THAN CLEAR AREAS,
THEN UPPER 40S WOULD BE MORE LIKELY THAN LOWER OR MID 40S. THERE IS
A VERY SLIGHT CHANCE OF ELEVATED SHOWERS DEVELOPING TOWARD THURSDAY
MORNING AS WARM ADVECTION BEGINS IN THE ABSENCE OF SIGNIFICANT
MID-LEVEL CAPPING.
WEAK UPPER-LEVEL RIDGING IS PROGGED BY ALL THE MODELS TO DEVELOP
ACROSS THE ROCKIES BY FRIDAY AND SATURDAY AND PERSIST INTO SUNDAY,
WITH NORTHWEST TO WEST-NORTHWESTERLY MID TO HIGH-LEVEL FLOW ACROSS
THE ROCKIES. THERE WILL BE A SLIGHT MID-LEVEL DOWNSLOPE COMPONENT
ACROSS THE ROCKIES, WHICH WILL TEND TO SUPPORT SOUTHERLY WINDS AND
MOISTURE TRANSPORT INTO KANSAS. GIVEN THAT MID-LEVEL CAPPING TENDS
TO BE WEAK IN THESE REGIMES, NOCTURNAL STORM CLUSTERS COULD DEVELOP
SOMEWHERE ACROSS THE CENTRAL PLAINS IN THE MID-LEVEL BAROCLINIC
ZONE, POSSIBLY AS EARLY AS THURSDAY NIGHT(AS ALREADY MENTIONED), BUT
MORE LIKELY BY FRIDAY NIGHT. THE WARMEST TEMPERATURES FRIDAY AND
SATURDAY WILL BE IN FAR SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH
WHERE HIGHS COULD REACH INTO THE UPPER 80S TO LOWER 90S, WHILE
SLIGHTLY COOLER TEMPERATURES CAN BE EXPECTED FURTHER EAST. THE MID
TO UPPER-LEVEL FLOW WILL BECOME MORE ZONAL BY SUNDAY, ALLOWING FOR
SOME LOWERING OF SURFACE PRESSURES AND WARM ADVECTION IN THE LEE OF
THE ROCKIES ALONG WITH WARMING TEMPERATURES IN THE LOWER TROPOSPHERE
ACROSS THE CENTRAL PLAINS. HIGHS COULD REACH TO BETWEEN 95 AND 100F.
A DEEP UPPER-LEVEL TROUGH WILL AMPLIFY OFF OF THE WEST COAST BY
MONDAY, WITH UPPER-LEVEL RIDGING ACROSS THE PLAINS. MONDAY SHOULD BE
FAIRLY DRY WITH HIGH AFTERNOON TEMPERATURES IN THE LOWER TO MID 90S.
ISOLATED EVENING THUNDERSTORMS CANNOT BE RULED OUT AS THE MODELS ARE
DEPICTING A WEAK SURFACE BOUNDARY CLOSE BY. THERE IS SOME
UNCERTAINTY WITH REGARDS TO THE EVOLUTION OF THE LARGE SCALE PATTERN
BY TUESDAY AND WEDNESDAY OF NEXT WEEK AND THEREAFTER. THE ECMWF AND
GEM PROGRESS THE UPPER-LEVEL TROUGH INTO CALIFORNIA/NEVADA AREA BY
WEDNESDAY WHILE THE GFS PROGRESSES THE TROUGH INTO THE NORTHERN
ROCKIES AND WESTERN CANADA. BUT ALL THREE OF THESE MODELS MAINTAIN
UPPER-LEVEL RIDGING ACROSS THE PLAINS THROUGH WEDNESDAY. HOWEVER,
THE GFS AND ECMWF SHOW PRECIPITATION IN THE MIDDLE OF THE RIDGE AXIS
EACH DAY, POSSIBLY AS A RESULT OF DAYTIME HEATING AND WEAK CAPPING.
ALSO, THE ECMWF HINTS AT A PLUME OF MID-LEVEL MOISTURE PROGRESSING
FROM THE TROPICS INTO WESTERN KANSAS, AND THIS COULD ALSO RESULT IN
PRECIPITATION EVEN IN THE UPPER-LEVEL RIDGE AXIS. DESPITE THE
UPPER-LEVEL RIDGING, AFTERNOON TEMPERATURES COULD BE HELD DOWN INTO
THE UPPER 80S TO LOWER 90S TUESDAY BY CLOUDS AND PRECIPITATION IF
THIS MOIST SCENARIO ACTUALLY PANS OUT. SEVERE WEATHER CHANCES LOOK
MINIMAL DUE TO THE WEAK WINDS THROUGHOUT THE TROPOSPHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1226 AM CDT THU MAY 31 2012
A COLD FRONT HAS PASSED THROUGH THE TAF SITES SHIFTING THE WINDS
TO THE NORTH. THE PRESSURE GRADIENT ACROSS WILL INCREASE BEHIND
THIS FRONT AS HIGH PRESSURE BUILDS INTO SOUTHWEST KANSAS
INCREASING WINDS FROM AROUND 12 KNOTS TO AROUND 20 KNOTS BY 09Z
ACROSS DDC AND GCK TERMINALS. THE HAYS TERMINAL SHOULD REMAIN
AROUND 12 KNOTS. MVFR CONDITIONS WILL ALSO BE POSSIBLE AFTER 09Z
AS STRATUS AOA020 FILTERS IN BEHIND THE AFOREMENTIONED FRONT.
CLEARING IS ANTICIPATED AFTER SUNRISE TOMORROW WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 83 59 88 / 10 20 20 20
GCK 47 84 59 88 / 10 20 10 20
EHA 50 89 59 90 / 10 10 10 20
LBL 49 87 59 90 / 10 10 10 20
HYS 46 78 57 86 / 20 20 20 10
P28 48 78 59 86 / 10 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...FINCH
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1155 PM CDT WED MAY 30 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM - THROUGH THURSDAY...
19Z WATER VAPOR IMAGERY SHOWS A COMPACT SHORTWAVE DIVING SOUTHEAST
INTO SD. ELEVATED STORMS HAVE PERSISTED ACROSS CENTRAL NEB DUE TO
THIS WAVE. AT THE SFC...A WARM FRONT IS LIFTING NORTH THROUGH THE
FORECAST AREA WITH DEEPER MOISTURE ADVECTING NORTH INTO CENTRAL
AND WESTERN KS. AT 19Z THE WARM FRONT WAS NEAR OR JUST SOUTH OF
THE KS RIVER.
FOR TONIGHT...THUNDERSTORMS ARE EXPECTED TO BECOME WIDESPREAD AND
MOVE SOUTHEAST ACROSS THE AREA. THE PAST SEVERAL RUNS OF THE HIGH
RES HRRR HAVE SUGGESTED THAT AN ISOLATED STORM OR TWO MAY TRY TO
DEVELOP ON THE WARM FRONT AROUND 4 PM...THEN A LINEAR CONVECTIVE
SYSTEM MOVE ACROSS THIS EVENING. WITH THE WARM SECTOR MOVING INTO
THE AREA...INSTABILITY HAS BEEN INCREASING. MID LEVEL LAPSE RATES
ARE NEAR 8 C/KM WITH ML CAPE AS HIGH AS 2000 J/KG. SO THERE WOULD BE
ENOUGH INSTABILITY FOR STORMS TO BECOME SEVERE. IF DISCRETE STORMS
ARE ABLE TO DEVELOP THIS AFTERNOON ALONG THE WARM FRONT...THERE
COULD BE A TORNADO THREAT INITIALLY. HOWEVER LOW LEVEL SHEER IS
RATHER MARGINAL SO THIS WOULD WORK AGAINST TORNADOS. IF THE LINE OF
STORMS IS ABLE TO FORM A STRONG COLD POOL...STRONG STRAIGHT LINE
WINDS MAY BE MORE OF A CONCERN AFTER DARK IN EASTERN KS. SO WITH THE
STRONG DYNAMICS FROM THE UPPER WAVE AND INCREASING MOISTURE FROM THE
SOUTH...WILL INCREASE POPS FOR TONIGHT TO CATEGORICAL. EXPECT LOWS
TO BE FAIRLY SIMILAR TO THE PREV FORECAST WITH AROUND 50 IN THE FAR
NORTHWEST TO NEAR 60 IN THE FAR SOUTHEAST.
BY THURSDAY...THINK THAT THE BULK OF CONVECTION WILL BE MOVING EAST
OF THE AREA AS THE SHORTWAVE BEGINS TO CLOSE OFF OVER THE MID MS
RIVER VALLEY. MODELS INDICATE THERE IS STILL SOME PV ANOMALIES
MOVING AROUND THE BACK SIDE OF THE UPPER WAVE ALONG THE MO RIVER.
ALTHOUGH MUCH IF NOT ALL OF THE INSTABILITY SHOULD BE SHIFTED TO THE
EAST. SO THERE MAY BE SOME PRECIP LINGER ACROSS NORTHEAST KS DURING
THE DAY. BUT WOULD EXPECT THAT TO BE MAINLY SHOWERS. THERE COULD BE
SOME INSOLATION THURSDAY...ESPECIALLY ACROSS NORTH CENTRAL KS AND
WITH THE MODELS TENDED TO BE A LITTLE COOL THE PAST COUPLE
DAYS...HAVE BUMPED UP HIGHS TO THE UPPER 60S AND AROUND 70 IN NORTH
CENTRAL AND EAST CENTRAL KS AND THE MID 60S NORTHEAST WHERE CLOUD
COVER AND PRECIP CHANCES SHOULD BE HIGHER.
WOLTERS
MID TERM - THURSDAY NIGHT THROUGH SATURDAY...
THERE ARE TWO PRIMARY WEATHER STORIES IN THE MID TERM. THE FIRST
SURROUNDS A CHILLY START TO FRIDAY MORNING. A COOL AIRMASS WILL
SETTLE OVERHEAD WHILE SURFACE HIGH PRESSURE DRIFTS ACROSS EASTERN
KANSAS. EXPECT MOST CLOUD COVER TO HOLD OFF UNTIL AFTER SUNRISE SO
THE COMBINATION OF LIGHT WINDS...CLEAR SKIES...AND A COOL AIRMASS
SHOULD LEAD TO MORNING LOWS IN THE MIDDLE 40S. ANY UNCERTAINTY IN
THIS COLD FORECAST WOULD REST WITH CLOUD COVER POTENTIAL AS ANY MID
CLOUDS MOVING IN FROM THE WEST WOULD RESULT IN A SHARP JUMP IN LOW
TEMPS UNDER THE CLOUDS.
THE OTHER FOCUS DURING THE MID TERM IS ON RAIN CHANCES FRIDAY INTO
FRIDAY NIGHT. A CLOSED UPPER TROUGH WILL REMAIN NEARLY STATIONARY
OVER THE GREAT LAKES ON FRIDAY WHILE A SHORT WAVE TROUGH WILL PASS
THROUGH NEBRASKA AND EASTERN KANSAS ON THE BACK SIDE OF THE MAIN
SYSTEM. IT APPEARS THAT THERE WILL BE AN ENHANCED ZONE OF
ISENTROPIC ASCENT ACROSS THE AREA ALONG A MID LEVEL FRONTAL
BOUNDARY LOOSELY ASSOCIATED WITH THIS SHORT WAVE. THE ADDITION OF
WEAK UPPER LEVEL ASCENT ASSOCIATED WITH THE WAVE AND A VERY WEAK
SURFACE COLD FRONT SHOULD LEAD TO ISOLATED TO SCATTERED SHOWERS
WITH A THUNDERSTORM OR TWO POSSIBLE. THE BEST PRECIP CHANCES
APPEAR TO COME LATE FRIDAY AFTERNOON INTO EARLY SATURDAY
MORNING...AND DO NOT EXPECT MUCH MORE THAN SCATTERED LIGHT TO
MODERATE RAIN.
A WARMING TREND WILL BEGIN FOR SATURDAY WITH SOME WARM AIR
ADVECTION ALOFT AND PLENTY OF SUNSHINE BRINGING HIGHS INTO THE
80S.
BARJENBRUCH
LONG TERM - SUNDAY THROUGH WEDNESDAY...
A LONG WAVE TROUGH AXIS WILL SET UP ACROSS THE EASTERN HALF OF THE
CONUS WHILE LONG WAVE RIDGING GRADUALLY INCREASES ACROSS THE
ROCKIES AND HIGH PLAINS. EXPECT THE LOCAL FORECAST AREA TO BE IN A
BIT OF A PINCH POINT BETWEEN THE TROUGH AND RIDGE THROUGH THE
FIRST PART OF THE EXTENDED PERIOD WITH EPISODES OF ENHANCED LIFT
ACROSS THE AREA AS WARM ADVECTION ATTEMPTS TO SURGE NORTH OVER A
WEAK STATIONARY FRONTAL BOUNDARY DRAPED ACROSS KANSAS. THUS...IT
WILL BE A FAIRLY UNSETTLED PERIOD WITH OCCASIONAL CHANCES FOR
THUNDERSTORMS BOTH DURING THE PEAK HEATING HOURS AS WELL AS SOME
POTENTIAL FOR OVERNIGHT MCS ACTIVITY. THE BEST CHANCE FOR
WIDESPREAD PRECIP APPEARS TO COME SUNDAY NIGHT AS A SHORT WAVE
TROUGH MOVES OVER THE RIDGE AND ACROSS THE REGION. THE BEST CHANCE
FOR DRY WEATHER APPEARS TO COME MONDAY THROUGH TUESDAY AS SLIGHTLY
DRIER AIR MOVES IN...BUT THUNDERSTORM CHANCES COME BACK INTO THE
FORECAST BY THE MIDDLE OF NEXT WEEK AS A TROUGH DEEPENS OVER THE
ROCKIES AND MOISTURE PUSHES BACK NORTH INTO THE AREA.
TEMPERATURES WILL BE WARM...LIKELY IN THE 90S AT TIMES...BUT WILL
ALSO BE HIGHLY DEPENDENT UPON CLOUD COVER. ANY SUNNY DAYS IN THE
LONG TERM WILL LIKELY RESULT IN HIGHS AT LEAST IN THE LOWER 90S
WHILE LOW TEMPS MOST NIGHTS SHOULD BE IN THE UPPER 60S TO AROUND
70.
BARJENBRUCH
&&
.AVIATION...
TIMING AND HEIGHTS OF STRATUS DECK ARE THE MAIN CONCERNS FOR THIS
FORECAST. CIGS ON IFR/MVFR BORDER COMING SOUTHEAST FROM EASTERN
NEBRASKA SHOULD REACH THE TERMINALS IN THE 9-12Z PERIOD BASED ON
TRENDS...THOUGH GUIDANCE IS A BIT QUICKER. WILL GO WITH OBS AT
THIS POINT. GIVEN UPSTREAM AND GUIDANCE AGREEMENT...EXPECT A FEW
HOURS OF IFR CIGS BEFORE RISING TO VFR AROUND 16Z.
65
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
251 AM EDT THU MAY 31 2012
.UPDATE...
ISSUED AT 728 PM EDT WED MAY 30 2012
PERSISTENT CLOUDS CONTINUE TO SLOWLY DIMINISH OVER THE CWA THIS
EVENING. THEY HAVE BEEN THE THICKEST OVER THE WCNTRL/SCNTRL PORTION
OF THE AREA AND MAY EVEN BE PRODUCING A FEW SPRINKLES OVER NRN
MENOMINEE COUNTY. RAP RUNS CONTINUE TO HAVE THE BEST HANDLE ON THESE
CLOUDS ON THE 0.5-1KM LAYER AND WITH THE LOSS OF DIURNAL
HEATING...EXPECT THEM TO QUICKLY DIMINISH WHILE PUSHING S. DID DELAY
THE EXIT CLOSER TO MIDNIGHT OVER THE SCNTRL.
WITH THE CLOUDS DIMINISHING AND COOL DRY AIR IN PLACE...PWAT VALUES
AROUND 35 PERCENT OF NORM...EXPECT TEMPS TO QUICKLY FALL AFTER
SUNSET WHERE SKIES ARE CLEAR. HAVE SOME CONCERN THAT THE INITIAL
CLEAR SKIES OVER THE EAST WILL ALLOW SOME OF THE TRADITIONAL COLD
SPOTS TO NEAR FREEZE WARN CRITERIA...28 DEGREES FOR 3HRS. BUT
LINGERING WINDS ALOFT MAY PROVIDE JUST ENOUGH MIXING TO KEEP TEMPS
AT OR SLIGHTLY ABOVE. THUS...WILL LEAVE HEADLINES AS IS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
CURRENTLY...THERE IS AN UPPER TROUGH DRAPED N OF THE CWA...WITH SFC
RIDGING PUSHING IN FROM THE W. NW LOW LEVEL WINDS COMBINED WITH
LINGERING LOW LEVEL MOISTURE AND COOLER 850MB TEMPS AROUND -2C HAS
LEAD TO CLOUDS OVER THE AREA TODAY...BUT THE CLOUD COVER IS AND WILL
CONTINUE TO DIMINISH THROUGH THIS AFTERNOON AND EVENING. THE UPPER
TROUGH WILL MOVE TO THE CENTER OF THE CWA BETWEEN 12Z AND 18Z
THU...WITH THE SFC RIDGE MOVING FARTHER INTO THE CWA THROUGH THE
NIGHT. THIS LEADS TO CLEARING SKIES AS MUCH DRIER AIR MOVES
OVERHEAD...SO TEMPS WILL BE COLD TONIGHT SEEING AS HOW HIGH TEMPS
LATE THIS AFTERNOON INTO THIS EVENING WILL BE IN THE MID 40S TO MID
50S. EXPECT WIDESPREAD FROST OVER ALL BUT THE KEWEENAW
PENINSULA...MAINLY INLAND FROM THE GREAT LAKES WHERE TEMPS WILL FALL
INTO THE UPPER 20S...COLDEST OVER THE INTERIOR WEST AND CENTRAL.
THE SWRN EXTENT OF THE UPPER TROUGH DEEPENS OVER SW WI BY 00Z FRI IN
RESPONSE TO AN UPPER JET MOVING IN FROM THE NRN PLAINS. AT THE SAME
TIME...A W-E ORIENTED UPPER RIDGE WILL PUSH TO FAR NRN LAKE
SUPERIOR. HOWEVER...MOST OF THE CLOUDS AND ALL OF THE PRECIP FROM
THIS SYSTEM AS IS STRENGTHENS WILL STAY S OF THE CWA THU. 850MB
TEMPS WILL INCREASE TO A CWA AVG VALUE OF AROUND 5C BY 00Z
FRI...WHICH WILL ALLOW FOR WARMER HIGH TEMPS IN THE 50S NEAR LAKE
SUPERIOR...AND IN THE 60S INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
IN THE LONGER TERM...INITIAL FOCUS OF FCST WILL BE ON RAIN POTENTIAL
FRI/SAT AS SYSTEM LIFTS THRU LWR MI...POSSIBLY BRUSHING THE FCST
AREA WITH RAIN SHIELD. FARTHER DOWN THE LINE...PATTERN SHOULD
OVERALL SUPPORT DRY WEATHER AS MID/UPPER RIDGE BUILDS THRU CNTRL
NAMERICA.
BEGINNING THU NIGHT...SHORTWAVE DROPPING INTO THE MIDWEST WILL
DEEPEN INTO A MIDLEVEL LOW CENTERED VCNTY OF CHICAGO BY FRI MORNING.
UPPER MI REMAINS UNDER SFC RIDGING N OF SYSTEM...SO DRY WEATHER IS
EXPECTED THU NIGHT. SHOULD SEE AN INCREASE IN HIGH CLOUDS EXPANDING
N FROM THE ORGANIZING SYSTEM TO THE S. NONETHELESS...LIGHT/CALM WIND
AND PRECIPITABLE WATER 40-60PCT OF NORMAL SUGGEST FAVORING THE LOWER
END OF GUIDANCE. FROST MAY BE AN ISSUE IN THE TYPICAL COLD SPOTS...
DEPENDING ON HOW QUICKLY HIGH CLOUDS INCREASE.
SYSTEM ORGANIZING TO THE S THU NIGHT WILL TRACK THRU THE GREAT LAKES
REGION FRI/SAT. AFTER SHOWING A NW TREND TO SYSTEM YESTERDAY...
MODELS HAVE SETTLED TOWARD A MID LEVEL LOW TRACK ACROSS LWR MI AND
TOWARD JAMES BAY. TRACK IS FAR ENOUGH TO THE E THAT ONLY THE ERN
FCST AREA MAY GET BRUSHED BY ITS PCPN SHIELD FRI INTO SAT. AT THIS
POINT...CHC POPS STILL LOOK ON TRACK...BUT WILL TRIM WRN EXTENT OF
POPS E TO ROUGHLY A MUNISING/MENOMINEE LINE.
SUN THRU WED...MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN
AMPLIFYING CNTRL NAMERICA RIDGE NEXT WEEK AS A RIDGE OVER THE
ROCKIES THIS WEEKEND DRIFTS E AND MERGES WITH A POSITIVE ANOMALY
RETROGRADING FROM THE DAVIS STRAIT. A TROF WILL BE SITUATED OVER THE
WRN CONUS WITH A DEEPER TROF OVER THE NE. RESULT WILL BE NWRLY FLOW
GRADUALLY BECOMING NRLY BY THE MIDDLE OF THE WEEK AS RIDGE SHARPENS
JUST TO THE W. PATTERN SHOULD TEND TO FAVOR DRIER CONDITIONS HERE
WITH BUILDING MIDLEVEL RIDGE TO THE W AND NW SUPPORTING SFC HIGH
PRES GRADUALLY EXPANDING S FROM NCNTRL CANADA/HUDSON BAY INTO THE
GREAT LAKES REGION. HOWEVER...SUMMERTIME NWRLY FLOW CAN OFTEN LEAD
TO SCT DIURNAL CONVECTION WITH ANY MINOR SHORTWAVE PROGRESSING THRU
THE FLOW. TO SOME EXTENT...MEDIUM RANGE GUIDANCE OVER THE LAST FEW
DAYS HAS SUGGESTED THAT POTENTIAL. ALTHOUGH NOT WELL AGREED UPON...
THERE HAS BEEN A SIGNAL IN RECENT DAYS FOR A SHORTWAVE TO PASS THRU
THE AREA MON...SO FCST WILL CONTINUE TO INCLUDE LOW POPS LATE SUN
INTO MON. LATEST MODEL RUNS APPEAR TO BE TRENDING AWAY FROM THIS
SHORTWAVE CUTTING THRU THE BUILDING RIDGE AND INTO THE UPPER
LAKES...SO POPS HAVE BEEN DROPPED MOSTLY TO SLIGHT CHC. BEYOND
MON...SINCE THE EXPECTED PATTERN DOES NOT FAVOR ORGANIZED PCPN
EVENTS...PLAN TO KEEP FCST ON THE DRY SIDE GIVEN THE VERY LOW
PREDICTABILITY AT THIS TIME RANGE OF ANY MINOR SHORTWAVES AND
ASSOCIATED POTENTIAL SCT PCPN. WITH SFC HIGH PRES SLOWLY BUILDING S
FROM NRN CANADA...THERE SHOULD BE A WIND COMPONENT OFF LAKE SUPERIOR
MOST DAYS TO KEEP LAKESIDE LOCATIONS ON THE COOLER SIDE. INLAND...
TEMPS SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL FOR EARLY JUNE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 251 AM EDT THU MAY 31 2012
HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL KEEP LIGHT/VRB WINDS
AND VFR CONDITIONS THROUGH THE TAF PERIOD. MODELS SHOW HIGH CLOUDS
DEVELOPING OVER INLAND AREAS /KIWD AND KSAW/...BUT WITH SIGNIFICANT
DRY AIR IN PLACE...ONLY WENT WITH SCATTERED DECK.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 439 PM EDT WED MAY 30 2012
GUSTY WINDS WILL CONTINUE TO DIMINISH FROM W TO E THIS EVENING AS
HIGH PRES BUILDS INTO THE UPPER LAKES. BY LATE TONIGHT...WINDS WILL
BE UNDER 15KT. WINDS WILL REMAIN MOSTLY UNDER 15KT THRU THU AND INTO
FRI AFTN. WINDS MAY INCREASE A LITTLE FRI NIGHT AND SAT OVER EASTERN
LAKE SUPERIOR AS LOW PRES MOVES NE THRU THE CNTRL GREAT LAKES
REGION. OTHERWISE...WINDS WILL GENERALLY REMAIN ON THE LIGHT SIDE
INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ002-
004>007-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...JMW
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
403 AM CDT Thu May 31 2012
.DISCUSSION...
Short Range (Thursday through Saturday)
Bulk of shower and thunderstorm activity appears to be splitting the
forecast area this morning. MCS over southwest Missouri should
continue general eastward progression, while shower activity associated
with deepening upper level trough so far has mainly been confined to
north of the Missouri-Iowa state line. Short range HRRR model has
been persistent this morning in filling area of precipitation in over
northern Missouri and it appears to be materializing with the last
few radar volume scans over northern central Missouri.
Surface low currently located over northeast Oklahoma forecast to
push northeast across southern Missouri today as decent cold air
advection sets in behind the system. Still anticipating a good deal
of cloud cover across the region today, however given current radar
trends will lower PoPs especially over the western 2/3 of forecast
area. There may be some clearing this afternoon over the western
part of the forecast area, however model soundings seem to hint at
bringing some additional cloud cover back into the region after
sunset. Will refine with later forecasts, but this could have an
impact on morning low temperatures on Friday.
With surface high pressure dominating the weather on Friday,
depending on morning cloud cover, should see chilly start with
temperatures in the 40s at most locations. In the meantime upper
level trough becomes established over the Great Lakes putting
forecast area in northwest flow pattern. Some indications that weak
low-level warm advection and isentropic ascent set up for Friday
night into Saturday morning. This could interact with subtle
shortwave/speed max rotating through mean trough over the Great Lakes
to provide for some elevated convection. At this time though it
appears best chance for activity would remain north and east of
forecast area so have trimmed PoPs a bit to into the slight chance
category.
MJM
Medium Range (Sunday through Wednesday)...
Later half of the forecast arrives Sunday with conditions across the
Central Plains warming back up after a few days of below to near
normal temperatures. The pattern across the nation Sunday will begin
rather benignly as it will still be relatively flat, though that
will quickly change as a trough shifts onshore across the Pacific
Coast, with a corresponding amplification of a ridge across the
Plains States. This amplification will bring above normal
temperatures back to the region, which should then prevail through
at least the first half of the work week.
Some focus will be needed for POPs late in the weekend and into the
beginning of the work week. Verity of mid-range models are
advertising a shortwave crossing the ridge axis Sunday, which
generates precipitation across our neck-of-the-woods Sunday and
Sunday night, with some models lingering precipitation into the day
Monday. Confidence on the specifics of the shortwave (like timing
and location) are fairly low, but given the nocturnal environment
that the expanding ridge will bring to the Plains, thoughts are this
shortwave my spawn a MCS Sunday night. Have limited chance POPs to
the overnight hours of Sunday with this expectation. Otherwise,
models also have a smattering of slight chance POPs in the coming
work week, but the output seems to suggest that they are having
issues with the generally warm and moist environment present under
the ridge. So, have trimmed much of the slight chance POPs from the
days after Monday.
Cutter
&&
.AVIATION...
For the 06Z TAFs...VFR showers continue to effect the Kansas City
terminals early this morning, with still another wave of showers
poised to spread across the Kansas-Missouri border again early this
morning. Next round of showers will have some lower ceilings
associated, but have limited the low CIGS to 2500 ft owing to current
upstream trends. What ceilings do move in this morning should scatter
out by the mid-morning hours, with boundary layer mixing then
bringing the days gusty winds.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
354 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 1215 AM CDT THU MAY 31 2012
OBSERVED TRENDS ON RADAR AS WELL AS THE LATEST MODEL GUIDANCE NOW
STRONGLY SUGGEST THAT THE TWO MAIN GENERATORS OF RAIN WILL LARGELY
DO THE SPLITS AROUND THE FA. THE FIRST UPPER LEVEL DISTURBANCE
DRIVING THE MCS OVER SERN KS AND FAR SWRN MO WILL EDGE THE FA IN
THE SW AND CLIP KCOU LATE TONIGHT BUT SHOULD ENTIRELY MISS THE STL
METRO TAFS. PCPN ASSOCIATED WITH THE SECOND MORE NLY UPPER LEVEL
SYSTEM IS FILLING IN A BIT MORE OVER IA AND ERN NEBRASKA AND IS
EXPECTED TO MAINLY EDGE THE NRN AND ERN FA LATE TONIGHT AND
THURSDAY. SOME DEGREE OF FILLING IN IS EXPECTED FOR AREAS FURTHER
S INTO STL METRO MAINLY DURING THURSDAY MORNING AND MIDDAY BEFORE
IT ALL HEADS E. SFC LO PRES WILL OOZE THRU THE FA THURSDAY MORNING
WHEN THIS PCPN SHOULD TRY TO FILL IN...WITH A TRAILING CDFNT IS
THEN EXPECTED TO SWEEP THRU AND END MUCH OF THE PCPN CHCS AT THAT
POINT. SOME PATCHY LIGHT PCPN IS STILL POSSIBLE HEADING INTO THE
EVENING.
SPECIFICS FOR KSTL...VFR CONDITIONS TO PREVAIL AT THIS POINT UNTIL
PROBABLY THURSDAY AFTERNOON WHEN CD FROPA IS EXPECTED TO BRING IN
SOME WRAPAROUND LO CLOUDS THAT WILL LAST THRU MUCH OF THURSDAY
NIGHT. PCPN CHCS LOOK PRETTY MINIMAL WITH FIRST WAVE NOW
PROCEEDING THRU SERN KS AND SWRN MO AND IFFY WITH THE SECOND WAVE.
MAY SEE SOME FILLING IN THURSDAY MORNING AND MIDDAY WHEN SECOND
WAVE PASSES MAINLY TO THE N BUT FROPA SHOULD LARGELY END PCPN
CHCS...ALTHOUGH SOME PATCHY LIGHT PCPN STILL POSSIBLE. HAVE HELD
OFF ON IFR LATE THURSDAY UNTIL WE SEE BETTER EVIDENCE OF
WIDESPREAD LO CLOUD DEVELOPMENT.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
301 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.AVIATION...
ISSUED AT 1215 AM CDT THU MAY 31 2012
OBSERVED TRENDS ON RADAR AS WELL AS THE LATEST MODEL GUIDANCE NOW
STRONGLY SUGGEST THAT THE TWO MAIN GENERATORS OF RAIN WILL LARGELY
DO THE SPLITS AROUND THE FA. THE FIRST UPPER LEVEL DISTURBANCE
DRIVING THE MCS OVER SERN KS AND FAR SWRN MO WILL EDGE THE FA IN
THE SW AND CLIP KCOU LATE TONIGHT BUT SHOULD ENTIRELY MISS THE STL
METRO TAFS. PCPN ASSOCIATED WITH THE SECOND MORE NLY UPPER LEVEL
SYSTEM IS FILLING IN A BIT MORE OVER IA AND ERN NEBRASKA AND IS
EXPECTED TO MAINLY EDGE THE NRN AND ERN FA LATE TONIGHT AND
THURSDAY. SOME DEGREE OF FILLING IN IS EXPECTED FOR AREAS FURTHER
S INTO STL METRO MAINLY DURING THURSDAY MORNING AND MIDDAY BEFORE
IT ALL HEADS E. SFC LO PRES WILL OOZE THRU THE FA THURSDAY MORNING
WHEN THIS PCPN SHOULD TRY TO FILL IN...WITH A TRAILING CDFNT IS
THEN EXPECTED TO SWEEP THRU AND END MUCH OF THE PCPN CHCS AT THAT
POINT. SOME PATCHY LIGHT PCPN IS STILL POSSIBLE HEADING INTO THE
EVENING.
SPECIFICS FOR KSTL...VFR CONDITIONS TO PREVAIL AT THIS POINT UNTIL
PROBABLY THURSDAY AFTERNOON WHEN CD FROPA IS EXPECTED TO BRING IN
SOME WRAPAROUND LO CLOUDS THAT WILL LAST THRU MUCH OF THURSDAY
NIGHT. PCPN CHCS LOOK PRETTY MINIMAL WITH FIRST WAVE NOW
PROCEEDING THRU SERN KS AND SWRN MO AND IFFY WITH THE SECOND WAVE.
MAY SEE SOME FILLING IN THURSDAY MORNING AND MIDDAY WHEN SECOND
WAVE PASSES MAINLY TO THE N BUT FROPA SHOULD LARGELY END PCPN
CHCS...ALTHOUGH SOME PATCHY LIGHT PCPN STILL POSSIBLE. HAVE HELD
OFF ON IFR LATE THURSDAY UNTIL WE SEE BETTER EVIDENCE OF
WIDESPREAD LO CLOUD DEVELOPMENT.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1238 AM CDT THU MAY 31 2012
.AVIATION...06Z KGRI TAF...IFR CIGS WILL CONTINUE FOR THE NEXT
HOUR OR TWO AT KGRI AS CIGS ALONG LEADING EDGE OF STRATUS RUNNING
BETWEEN 7 AND 9 HUNDRED FEET. HOWEVER...EXPECT THESE IFR CIGS TO
BE BRIEF BASED ON UPSTREAM OBSERVATIONS...AND BROUGHT CIGS UP TO
MVFR LEVELS BY 08Z. THEREAFTER...EXPECT LOW LEVEL STRATUS TO HOVER
AT THE TERMINAL THROUGH THE AFTERNOON HOURS THURSDAY...SLOWLY
LIFTING AND EVENTUALLY CLEARING BY AROUND 02Z FRIDAY. WINDS WILL
GENERALLY REMAIN NORTHERLY THROUGH THE PERIOD BETWEEN
12-18KTS...AS A SURFACE HIGH ACROSS THE NORTHERN PLAINS CONTINUES
ITS ADVANCE SOUTHWARD. THIS HIGH WILL BECOME CENTERED ACROSS
NEBRASKA BY EARLY EVENING...AND THEREFORE EXPECT A RETURN TO LIGHT
WINDS AROUND SUNSET.
&&
.PREV DISCUSSION... /ISSUED 938 PM CDT WED MAY 30 2012/
UPDATE...AFTER A MORE-ACTIVE-THAN-EXPECTED DAY THAT FEATURED
ROUGHLY 6 HOURS OF SEVERE THUNDERSTORMS MAINLY ACROSS THE SOUTHERN
1/2 OF THE CWA...THINGS HAVE QUIETED DOWN CONSIDERABLY OVER THE
PAST FEW HOURS...WITH WHAT SHOULD BE THE LAST FEW WEAK STORMS OF
THE EVENING GRADUALLY EXITING A HANDFUL OF FAR SOUTHERN/SOUTHEASTERN
COUNTIES WITHIN THE NEXT 1-2 HOURS. 02Z OBJECTIVE SURFACE ANALYSIS
DEPICTS THE PRIMARY SYNOPTIC COLD FRONT PUSHING SOUTH OUT OF FAR
SOUTHERN NEB ZONES INTO KS...WITH STEADY BUT NOT OVERLY STRONG NORTH
BREEZES PUSHING IN BEHIND THE FRONT...DRIVEN BY A 1020MB HIGH
CENTERED OVER SOUTHERN ND/NORTHERN SD. ALTHOUGH OBJECTIVE
MESOSCALE ANALYSIS INDICATED THAT PARTS OF NORTH CENTRAL KS ZONES
MAY STILL BE HOLDING ON TO MUCAPE IN EXCESS OF 500 J/KG...THUNDER
POTENTIAL IS DEFINITELY ON A FAST DECLINE AS THE LOW LEVEL COLD
FRONT CONTINUES TO PUSH SOUTHWARD. ALOFT...WATER VAPOR IMAGERY
SHOWS THE PRIMARY WEST-NORTHWEST FLOW 500MB VORT MAX CENTERED NEAR
THE IA/NE/SD/MN BORDER AREA...WITH THE BEST LARGE SCALE FORCING
STEADILY DEPARTING EAST AS THE NIGHT PROGRESSES. ALTHOUGH SOME
LIGHT SHOWER POTENTIAL CANNOT BE RULED OUT AFTER MIDNIGHT EVEN
AFTER THUNDER EXITS...DECIDED THAT SUPPORT FOR MEASURABLE PRECIP
WAS LOW ENOUGH POST-06Z TO SIMPLY GO WITH A SLIGHT CHANCE OF
SPRINKLES...AND EVEN THIS MAY BE OVERKILL PER THE LATEST HRRR RUNS.
MAY TWEAK OVERNIGHT LOWS DOWNWARD VERY SLIGHTLY ON ONE MORE
FORECAST UPDATE WITHIN THE NEXT HOUR...WITH MUCH OF THE NORTHERN
CWA LIKELY HEADED FOR THE MID 40S...WITH UPPER 40S/NEAR 50
PREVAILING SOUTH. CLOUD TRENDS OVERNIGHT ARE SOMEWHAT
UNCERTAIN...AND EXPECT SOME VARIABILITY AS MID/HIGH CLOUDS RETREAT
SOMEWHAT FROM THE SOUTH AND LOWER STRATUS WORKS IN FROM THE NORTH.
PREV DISCUSSION... /ISSUED 306 PM CDT WED MAY 30 2012/
SHORT TERM...THROUGH 00Z FRIDAY. MORNING UPPER AIR ANALYSIS
INDICATES QUASI-ZONAL TO NORTHWESTERLY MID AND UPPER LEVEL FLOW
ACROSS CENTRAL PORTIONS OF THE CONUS...WITH SUBTLE RIDGING ACROSS
THE WESTERN AND EASTERN CONUS. MID AND UPPER LEVEL JET ENERGY IS
POSITIONED FROM THE NORTHWESTERN CONUS...ACROSS CENTRAL PORTIONS
OF THE CONUS AND ON INTO THE EASTERN CONUS. EARLY AFTERNOON WATER
VAPOR IMAGERY SHOWS INCREASED VALUES OF MID LEVEL MOISTURE FLOWING
IN FROM THE PACIFIC...PUSHING ACROSS THE NORTHWESTERN CONUS AND
INTO THE CENTRAL PLAINS. A MID LEVEL SHORT WAVE IS ALSO NOTED OVER
THE NORTHERN PLAINS...MOVING EAST/SOUTHEAST. AT THE SURFACE A
TROUGH OF LOW PRESSURE IS NOTED EXTENDING ACROSS WESTERN NEBRASKA.
IN ADDITION...AN AREA OF HIGH PRESSURE IS LOCATED OVER THE UPPER
MISSISSIPPI VALLEY...WITH LOW LEVEL RETURN FLOW ON THE BACK SIDE
OF THE SURFACE RIDGE INFILTRATING PORTIONS OF THE CENTRAL PLAINS.
THAT BEING SAID...CONVECTIVELY INDUCED OUTFLOW AT THE SURFACE
IS PROMOTING A BIT MORE CHAOTIC LOW LEVEL WIND FIELD ACROSS OUR
CWA...THAN THAT OF THE TRUE SOUTHEASTERLY WINDS WHICH ARE TRYING
TO DEVELOP. THIS MESO-HIGH IS PROMOTING A DIFFERENTIAL HEATING
BOUNDARY NOW EVIDENT ACROSS WESTERN PORTIONS OF OUR CWA. KUEX
INDICATES CONVECTION PERSISTING ACROSS MUCH OF SOUTH CENTRAL
NEBRASKA AS OF MID AFTERNOON.
LOW LEVEL RETURN FLOW IS HELPING PROMOTE LOW LEVEL THERMAL
ADVECTION AND RESULTANT ISENTROPIC UPGLIDE AND SATURATION OVER OUR
CWA...PRIMARILY ALONG THE 300-310K SURFACES. LAPS PROXIMITY
SOUNDINGS FROM ACROSS OUR WESTERN CWA SUGGEST AIR
PARCELS...ASCENDING FROM AROUND 700MB...ARE CONTENDING WITH LESS
THAN 30J/KG CIN AND WORKING WITH 600-1000J/KG CAPE. IN ADDITION...MID
AND UPPER LEVEL JET ENERGY IS HELPING PROMOTE DEEP LAYER BULK
SHEAR VALUES OF 30-40KTS. EVEN THOUGH THE INSTABILITY IS NOT
OVERLY IMPRESSIVE...THE COOL LOW TO MID LEVEL AIRMASS AND THE DEEP
LAYER SHEAR ARE MORE THAN COMPENSATING...WITH SEVERAL REPORTS OF
HAIL ALREADY REPORTED ACROSS THE AREA TODAY. BROAD-SCALE ASCENT
SHOULD PERSIST THROUGH THE REST OF THIS AFTERNOON AND INTO
TONIGHT...WITH DEEP LAYER SHEAR AND INSTABILITY ALSO LIKELY
PERSISTING. IN ADDITION...VISIBLE SATELLITE IMAGERY INDICATES LOW
LEVEL CONVERGENCE...ALONG THE DIFFERENTIAL HEATING BOUNDARY ACROSS
WESTERN PORTIONS OF THE CWA...IS HELPING TO PROMOTE WEAK
CONVECTIVE ACTIVITY. FINALLY...KLNX INDICATES ADDITIONAL
CONVECTION FIRING ALONG THE SURFACE TROUGH ACROSS WESTERN
NEBRASKA. THE TROUGH ACROSS WESTERN NEBRASKA...AND THE
DIFFERENTIAL HEATING BOUNDARY OVER WESTERN PORTIONS OF THE
CWA...ARE EXPECTED TO PUSH ACROSS OUR CWA THIS EVENING AND TONIGHT
AS THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN
PLAINS...ALSO PUSHES EAST/SOUTHEAST. AT THIS TIME IT APPEARS THE
BULK OF THE BROAD-SCALE ASCENT AHEAD OF THE NORTHERN PLAINS MID
LEVEL TROUGH AXIS SHOULD REMAIN TO OUR NORTHEAST...BUT ADDITIONAL
CONVECTIVE ACTIVITY WILL BE POSSIBLE OVER OUR AREA THROUGH TONIGHT
AS THE SURFACE TROUGH AND DIFFERENTIAL HEATING
BOUNDARY/STRENGTHENING LOW LEVEL BAROCLINIC ZONE CLEARS THE AREA.
GIVEN ALL THIS...WENT AHEAD AND PRESENTED LIKELY TO DEFINITE POPS
ACROSS THE CWA THROUGH 06Z...WITH POPS TAPERING OFF AFTER 06Z AS
LOW LEVEL FORCING MOVES OFF TO THE EAST/SOUTHEAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND DEEP LAYER SHEAR...WILL ALSO
CONTINUE THE SEVERE WORDING ACROSS THE AREA THROUGH THIS EVENING.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCES FOR THUNDERSTORMS ON AND OFF DURING THE
PERIOD AND TEMPERATURES.
START OFF THE PERIOD WITH NORTHWEST FLOW THAT BRINGS SEVERAL WEAK
UPPER LEVEL WAVES THROUGH THE REGION THURSDAY NIGHT THROUGH
SATURDAY. THE BEST OF THOSE WAVES SEEMS TO BE DURING THE FRIDAY TO
FRIDAY NIGHT TIME FRAME.
SATURDAY NIGHT THROUGH TUESDAY THERE IS AN UPPER LEVEL RIDGE THAT
MOVES THROUGH THE PLAINS. TEMPERATURES WARM UP...BUT THERE REMAINS
SOME WEAK UPPER LEVEL WAVES THAT MOVE THROUGH THE AREA AND BRING
SOME SPORADIC CHANCES FOR THUNDERSTORMS TO THE FORECAST AREA.
TUESDAY NIGHT INTO WEDNESDAY AN UPPER LEVEL LOW BREAKS DOWN THE
RIDGE AND A SURFACE LOW IN THE SOUTHERN PLAINS HAS AN INVERTED
TROUGH TO THE NORTH ACROSS THE AREA. WITH THIS THERE IS A CHANCE FOR
SOME THUNDERSTORMS. TEMPERATURES WILL COOL A LITTLE BIT AGAIN AFTER
THE RIDGE BREAKS DOWN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ROSSI
UPDATE...PFANNKUCH
SHORT TERM...BRYANT
LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
102 AM CDT THU MAY 31 2012
.DISCUSSION...
THE OVERALL FORECAST IS WELL ON TRACK...WITH ONLY MINIMAL CHANGES
REQUIRED TO BLEND TO THE LAST EST 06 UTC OBSERVED TRENDS. DID ADD A
SLIGHT CHANCE MENTION OF SHOWERS TO THE FAR SOUTHWEST OVERNIGHT
WITH THE LATEST RUNS OF THE HRRR SUPPORTING THE PROPAGATION OF
ONGOING SHOWER ACTIVITY ACROSS SOUTHEAST MONTANA INTO THE FAR
SOUTHWEST PORTIONS OF NORTH DAKOTA. DID MAINTAIN A MENTION OF
PATCHY FOG FOR LOCATIONS IMPACTED BY RAINFALL YESTERDAY. THE
CURRENT FROST ADVISORY LOOKS GOOD...WITH NO CHANGES REQUIRED.
&&
.AVIATION...
AT MIDNIGHT CDT...HIGH PRESSURE CENTERED NEAR MOBRIDGE
SOUTH DAKOTA IS EXPECTED TO REMAIN NEARLY STATIONARY OVERNIGHT. THE
FORECAST IS FOR VFR CONDITIONS AT ALL TAF SITES THROUGH 7 PM CDT
THURSDAY. ALTHOUGH VFR IS EXPECTED...ONE UNCERTAINTY IS THE ABUNDANT
LOW LEVEL MOISTURE FROM THE RECENT RAIN SOUTHWEST AND SOUTH CENTRAL.
WITH MAINLY CLEAR SKIES AND LIGHT WINDS THERE IS AN INCREASE THE FOG
POSSIBILITY. SO EXPECT KDIK/KBIS TO HAVE SOME LOCAL OR VICINITY FOG
BETWEEN 09Z/4 AM CDT AND 14Z/9 AM CDT. MENTIONED VCFG THERE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
NDZ018>020-033>036-041-042-044>047-050.
&&
$$
UPDATE...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
353 AM CDT THU MAY 31 2012
.DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
06Z TAF SET
COLD FRONT WILL MOVE INTO THE CWA AFTER 16Z. EXPECT TSRAS TO DEVELOP
ALONG AND AHEAD OF THE FRONT. HAVE TEMPOS AT EACH TAF SITE FOR BEST
TIME PERIOD OF SEEING TSRAS. THE TSRAS MAY TEMPORARILY BRING MVFR OR
LOWER CONDITIONS BUT OTHERWISE EXPECT VFR CONDITIONS OVER THE NEXT
24 HOURS. LIGHT WINDS WILL BECOME SW AT 10-12 KTS AHEAD OF THE
FRONT. BEHIND THE FRONT WINDS WILL SWITCH TO THE NW.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1154 PM CDT WED MAY 30 2012
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT SHWRS/TSTM 31/16Z-01/00Z. MVFR
FOG POSSIBLE CSV...OTHERWISE VFR/SKC CONDITIONS THRU 31/16Z.
EXPECT INCREASING DIURNAL BASED UNSTABLE ATM TO SUPPORT SCT TO
NUMEROUS SHWRS/TSTMS BY 31/22Z...BUT WITH SOME UNCERTAINTIES
PER LOCATION DEVELOPMENT DUE TO DEVELOPMENT BEING MAINLY DIURNAL
DRIVEN IN NATURE...WILL MENTION VCTS/CB REMARKS IN TAFS THRU 01/01Z.
EXPECT BKN VFR CB BASED CEILINGS BY 01/01Z ALSO...BUT TEMP MVFR
/IFR/LIFR CEILINGS POSSIBLE. BEST POTENTIAL FOR MVFR VSBYS/CEILINGS
AT OR AFTER 01/00Z AS SFC FRONTAL DYNAMICS SLOWLY APPROACH AREA.
&&
.PREV DISCUSSION.../ISSUED 706 PM CDT WED MAY 30 2012/
UPDATE...
LAPS CAP CONTINUES TO EXPAND THIS EVENING WHILE CAPES ARE ON THE
DOWNSWING. GIVEN THE ISC STATUS AND LATEST SHORT TERM QPF
EXPECTATIONS OVERNIGHT...WILL GO AHEAD AND SLASH POPS FOR ALL BUT
THE WESTERN QUARTER OF THE MID STATE. WILL KEEP 20 POPS GOING
ACROSS THE FAR WEST GIVEN THE SLIGHT MOISTURE ENHANCEMENT THAT IS
EXPECTED TOWARD 12Z FOR THAT AREA.
OTW...WILL INCREASE CLOUD COVERAGE ACROSS THE SOUTH FOR THIS
EVENING...GIVEN THE UPPER LEVEL BLOW OFF FROM THE WEAKENING STORMS
TO OUR SW. REMAINDER OF THE FORECAST...LOOKS TO BE IN GOOD SHAPE.
PREV DISCUSSION... /ISSUED 611 PM CDT WED MAY 30 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT OF SHWRS/TSTM 31/16Z-31/24Z.
EXPECT SCT AC/CI THRU 31/14Z WITH MVFR FOG POSSIBLE CSV PER LOW
LEVEL MOISTURE POOLING...CALM WINDS...AND CLRING SKIES. EXPECT
INCREASING UNSTABLE ATM TO SUPPORT SCT TO NUMEROUS SHWRS/TSTMS
BY 31/24Z...BUT WITH SOME UNCERTAINTIES PER LOCATION DEVELOPMENT
DUE TO DEVELOPMENT BEING MAINLY DIURNAL DRIVEN IN NATURE...THUS
WILL MENTION VCTS/CB REMARKS IN TAFS ONLY. EXPECT BKN VFR CB
BASED CEILINGS BY 31/24Z...BUT TEMP MVFR/IFR/LIFR CEILINGS POSSIBLE.
PREV DISCUSSION.../ISSUED 459 PM CDT WED MAY 30 2012/
UPDATE...
WRF...NAM AND GFS ARE ALL VIRTUALLY BONE DRY OVERNIGHT. RUC STILL
TRYING TO HANG ON TO CONVECTION WHICH HAS YET TO OCCUR. CURRENT
FCST IS IN THE 20-30 PERCENT RANGE. CONVECTION COULD STILL FIRE
BUT ITS LOOKING LESS AND LESS LIKELY.
THE PLAN FOR TONIGHT WILL BE TO GIVE THE CONVECTION CHANCES
ANOTHER HOUR OR TWO BEFORE WITHDRAWING THE OVERNIGHT POPS.
OVERNIGHT UPPER DIVERGENCE AND MOISTURE LEVELS ARE HELD AT
BAY. HOWEVER...MAY KEEP A SLIGHT CHANCE GOING ACROSS OUR SOUTHWEST AS PER
THE CURRENT PROXIMITY OF THIS AFTERNOONS CONVECTION.
OTW...QUIET NIGHT...ESPECIALLY COMPARED TO WHAT MAY BE TOMORROW AT
THIS TIME.
NO UPDATE AT THIS MOMENT...BUT LOOK FOR UPDATE WITH THE NEXT FEW HOURS.
PREV DISCUSSION.../ISSUED 311 PM CDT WED MAY 30 2012/
DISCUSSION...
AIR MASS SOMEWHAT STABLE THIS AFTERNOON ACROSS THE TENNESSEE
VALLEY WITH TEMPS IN THE 80S. DRIER AIR ALOFT HAS MIXED DOWN TO
THE SURFACE. WILL HAVE SMALL POPS IN FOR TONIGHT BUT THINK WE WILL
HAVE TO WAIT ON BOUNDARY TO OUR SOUTH TO LIFT NORTHWARD INTO
TENNESSEE THURSDAY MORNING TO PROVIDE FOCUS. EXPECT WE WILL SEE
SHOWERS AND STORMS ON THE INCREASE THURSDAY ESPECIALLY BY
AFTERNOON IN MOST AREAS. SHOWERS AND STORMS LOOK CATEGORICAL
THURSDAY NIGHT...ESPECIALLY EVENING. SOME STORMS COULD BE SEVERE
IN THE MID STATE LATE AFTERNOON AND THURSDAY EVENING AS SURFACE
LOW UNDERGOES CYCLOGENSIS AS IT ROLLS EAST FROM OKLAHOMA ON
THURSDAY AND INTO THE TENNESSEE AND OHIO VALLEYS BY LATE IN THE
DAY THURSDAY. WIND PROFILES WOULD SUGGEST DAMAGING WINDS AND LARGE
HAIL TO BE THE MAIN THREAT. RAIN SHOULD END FROM THE WEST FRIDAY
MORNING WITH HIGH PRESSURE WORKING INTO THE AREA FROM MISSOURI. A
DIRTY SURFACE RIDGE WILL BE OVER THE TENNESSEE VALLEY FOR THE NEXT
SEVERAL DAYS AS UPPER TROUGH RULES...WITH NO SIGNIFICANT RAIN
CHANCE UNTIL ABOUT TUESDAY OF NEXT WEEK AND THEN MODELS HAVE
FAIRLY LOW QPF.
AND NOW A LITTLE TRIVIA: NASHVILLE IS ON PACE TO HAVE THE 6TH
WARMEST MAY ON RECORD AND THE WARMEST SINCE 1991. NASHVILLE HAD
TWO DAYS OF 95 DEGREE HEAT THIS MONTH. THE HOTTEST TEMPERATURE
EVER RECORDED IN THE MONTH OF MAY IS 96 BACK IN 1937.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1002 AM CDT THU MAY 31 2012
.UPDATE...
RADAR TRENDS INDICATE THE CONVECTION HAS STRATIFORMED OUT SO THE
THREAT OF ANY TSRA ACROSS THE SOUTH THIRD OF THE CWFA HAS ENDED.
OVERALL THE FCST IS GENERALLY ON TRACK. MAX TEMPERATURES HAVE BEEN
LOWERED SLIGHTLY BASED ON READINGS UNDER THE COLD POOL YESTERDAY
AND THE EFFECT OF RAIN IN OTHER AREAS.
BASED ON CURRENT RADAR AND RAP TRENDS...TEMPERATURES WILL REMAIN
NEARLY STEADY IN THE UPPER 40S TO LOWER 50S THROUGH THE LATE
MORNING AND EARLY AFTERNOON HOURS. AS PRECIPITATION INTENSITY AND
AREAL COVERAGE DECREASES IN THE MID TO LATE AFTERNOON HOURS
TEMPERATURES WILL SLOWLY RISE. MAX TEMPERATURES WILL LIKELY OCCUR
IN THE 5 TO 7 PM TIME FRAME. AN UPDATE REFLECTING THESE CHANGES
WILL BE AVAILABLE SHORTLY. ..08..
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT THU MAY 31 2012/
AVIATION...
LOW PRESSURE SYSTEM WILL MOVE ACROSS MISSOURI TODAY WITH A TROUGH
EXTENDING NORTH INTO THE REGION. THIS WILL BRING A LARGE AREA OF
RAIN ACROSS THE TERMINALS TODAY. KCID AND KDBQ ARE ALREADY IN THE
MVFR TO EVEN IFR CIGS WITH MVFR TO VFR VISIBILITIES...AND THESE
ARE EXPECTED TO SPREAD EAST TO AFFECT KMLI AND KBRL IN THE NEXT
FEW HOURS. THESE LOWERED CONDITIONS TO CONTINUE TO AFFECT THE
TERMINALS UNTIL SOMETIME THIS AFTERNOON WHEN THE PRECIPITATION AND
LOWERED VISIBILITIES WILL END FIRST. MVFR CIGS LIKELY LINGER INTO
THE EVENING...AND SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY ALSO BE
POSSIBLE. CLEARING SHOULD GRADUALLY OCCUR FROM WEST TO EAST AFTER
00Z THIS EVENING. FOG IS POSSIBLE TOWARDS 12Z WITH RECENT RAINFALL
AND LIGHT WINDS. HAVE LEFT OUT OF TERMINALS FOR NOW...BUT WILL BE
CONSIDERED FOR LATER ISSUANCES. LE
PREV DISCUSSION... /ISSUED 336 AM CDT THU MAY 31 2012/
SYNOPSIS...
AN INVERTED TROUGH IS EXTENDED UP OVER THE REGION FROM A WEAK
SURFACE LOW OVER EASTERN OKLAHOMA AS OF 3 AM THIS MORNING. THIS
INVERTED TROUGH...AND THE LARGE AREA OF PRESSURE FALLS WITH IT IS ON
THE EAST SIDE OF A FAIRLY LARGE AREA OF LIGHT TO MODERATE
RAINFALL...EXTENDING FROM SOUTHERN WISCONSIN ACROSS THE NORTHERN
HALF OF THE FORECAST AREA BACK INTO SOUTHERN IOWA. AT 850MB...THERE
IS A CLOSED CIRCULATION MOVING OUT OF SOUTH DAKOTA INTO NORTHWEST
IOWA AS OF THE 00Z ANALYSIS...AND ANTICIPATE THAT BY NOW IT IS OVER
NORTHWEST IOWA. THERE IS ALSO A STRONG BAROCLINIC ZONE OVER THE
MIDWEST...WITH TEMPERATURES CHANGING FROM -1C AT KABR TO +16 AT
KTOP. THE 500MB TROUGH AND VORT MAX APPEAR TO BE RIGHT BEHIND
IT...PASSING OVER KFSD. THIS SYSTEM HAS MANY CHARACTERISTICS OF A
WINTER OR EARLY SPRING SYSTEM...AND IS STRONGLY DYNAMICALLY FORCED.
LE
SHORT TERM...TODAY AND TONIGHT...
THIS STRONGLY DYNAMICALLY FORCED SYSTEM WILL CONTINUE TO MOVE ACROSS
THE FORECAST AREA TODAY...AND OFF TO THE EAST TONIGHT. THE MAIN
AREA OF PRECIPITATION...WHICH SHOULD BE CENTERED OVER THE NORTHWEST
HALF OF THE FORECAST AREA AS OF 12Z THIS MORNING...WILL SLOWLY
ROTATE SOUTHEAST AHEAD OF THE 850MB LOW...CONTINUING THE RAIN ACROSS
MOST OF THE FORECAST AREA THIS MORNING. BY THIS AFTERNOON THE 850MB
LOW WILL BE NEAR KDBQ...AND AS THE FORCING WEAKENS WE SHOULD SEE THE RAIN
BEGINNING TO WEAKEN AND PERHAPS EVEN STOP DURING THE AFTERNOON FROM
THE NORTHWEST. HOWEVER...BY THIS EVENING THIS SYSTEM SHIFTS OFF TO
THE EAST FAIRLY QUICKLY AND WE SHOULD SEE THE RAIN STOP FROM WEST TO
EAST DURING THE LATE AFTERNOON AND EVENING HOURS. BY MIDNIGHT...I
ANTICIPATE THAT ONLY THE FAR EASTERN COUNTIES WILL STILL HAVE
RAIN...WHICH SHOULD SHUT OFF SOON AFTER. INITIALLY WE WERE THINKING
THERE WOULD BE SOME ELEVATED THUNDER THREAT WITH THIS SYSTEM ACROSS
THE SOUTH...BUT THERE HAS BEEN NO LIGHTING REPORTED OVER SOUTHERN
IOWA WHERE I WOULD HAVE EXPECTED IT TO START SHOWING UP IF IT WAS
GOING TO...SO HAVE DECIDED TO LEAVE IT OUT OF THE FORECAST FOR NOW.
THERE WILL BE SOME CONVECTIVE ELEMENTS WHICH MAY ENHANCE RAINFALL
RATES AT TIMES...BUT DO NOT EXPECT LIGHTNING TO BE A SIGNIFICANT
FACTOR WITH THIS STORM AT THIS TIME. WITH THE RAINFALL MOVING
IN...TEMPERATURES HAVE FALLEN INTO THE LOW 50S WHERE IT WAS IN THE
MID AND UPPER 50S BEFORE. EXPECT THAT TODAY IS GOING TO BE A CHILLY
MISERABLE DAY WITH THE RAIN FALLING...TEMPERATURES ONLY IN THE
50S...AND A BRISK EAST TO NORTHEAST WIND. IT IS GOING TO FEEL MORE
LIKE FALL OR EARLY SPRING THAN THE LAST DAY OF MAY. HIGHS WILL ONLY
BE IN THE MID 50S WHERE IT RAINS THE LONGEST...THOUGH SOME AREAS IN
THE WEST WHERE IT STOPS RAINING THE SOONEST MAY RISE INTO THE MID
AND EVEN UPPER 50S. THE DIURNAL RANGE TODAY IS NOT LIKELY TO BE
MUCH OVER 10 DEGREES...IF THAT. TONIGHT THE COOLER AND DRIER AIR
MOVING IN FROM THE NORTHWEST ALONG WITH THE CLEARING SKIES SHOULD
ALLOW TEMPERATURES TO FALL INTO THE 40 TO 45 DEGREE RANGE NEARLY
EVERYWHERE. LE
LONG TERM...FRIDAY THROUGH WEDNESDAY...
THE SURFACE AND UPPER LEVEL LOWS EXIT EAST INTO THE EASTERN GREAT
LAKES AND ONTARIO FRIDAY...LEAVING A NW FLOW OVER THE LOCAL AREA.
MODELS CONTINUE TO SUGGEST ONE OR MORE POSSIBLE WEAK MID LEVEL
SHORTWAVES THAT COULD PRODUCE SHOWERS IN THE NW FLOW UNTIL THE
BUILDING UPPER RIDGE OUT WEST PLACES A MORE SUBSIDENT REGIME OVER
THE AREA BY SATURDAY NIGHT.
FRIDAY...SURFACE RIDGE BUILDS INTO WESTERN IA...PROVIDING A DRY
AIRMASS ON NW WINDS OVER EASTERN IA INTO NW IL. A CONFLUENT FLOW
OVERHEAD AT 500 MB...AND THE STRONGER MID AND UPPER FLOW WELL TO THE
SW SHOULD RESULT IN A DRY DAY WITH AT LEAST PARTLY SUNNY SKIES.
MODELS SUGGEST MIXING WILL BE SUFFICIENTLY DEEP INTO THE STILL COOL
AIR ALOFT TO RESULT IN HIGHS IN THE UPPER 60S TO AROUND 70.
FRIDAY NIGHT INTO SATURDAY....WILL HAVE A POTENTIAL FOR LATE NIGHT
SHOWERS AND DAYTIME THUNDERSTORMS AS THE RIDGE AXIS OUT WEST BEGINS
TO MIGRATE EASTWARD SENDING THE MID LEVEL WAVE TRAIN OVERHEAD. THERE
CONTINUES TO BE SOME DISAGREEMENT AMONG THE MODELS AS TO WHICH
TIMEFRAME WILL SEE THE PRIMARY FORCING...SO POPS ARE KEPT IN A
SLIGHT TO LOW END CHANCE RANGE THROUGHOUT. TEMPERATURES SHOULD CONTINUE TO
MODERATE...WITH MINS IN THE 50S AND HIGHS SATURDAY INTO THE LOWER
70S.
SUNDAY THROUGH WEDNESDAY...A BLOCKY UPPER LEVEL PATTERN DEVELOPS AS
THE UPPER LEVEL RIDGE BUILDS AND SHARPENS OVER THE CENTRAL
U.S...FLANKED BY TROUGHS OVER THE COASTS. THIS SHOULD PUSH HIGHS
BACK INTO THE 80S...WHILE INCREASING GULF MOISTURE AND RISING
DEWPOINTS LIMIT MINS TO THE 60S. THERE CONTINUES TO BE A WEAK SIGNAL
TO SUGGEST A POSSIBLE MCS LATE SUNDAY NIGHT INTO MONDAY WHERE LOW
POPS ARE MAINTAINED. SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
642 AM CDT Thu May 31 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Thursday through Saturday)
Bulk of shower and thunderstorm activity appears to be splitting the
forecast area this morning. MCS over southwest Missouri should
continue general eastward progression, while shower activity associated
with deepening upper level trough so far has mainly been confined to
north of the Missouri-Iowa state line. Short range HRRR model has
been persistent this morning in filling area of precipitation in over
northern Missouri and it appears to be materializing with the last
few radar volume scans over northern central Missouri.
Surface low currently located over northeast Oklahoma forecast to
push northeast across southern Missouri today as decent cold air
advection sets in behind the system. Still anticipating a good deal
of cloud cover across the region today, however given current radar
trends will lower PoPs especially over the western 2/3 of forecast
area. There may be some clearing this afternoon over the western
part of the forecast area, however model soundings seem to hint at
bringing some additional cloud cover back into the region after
sunset. Will refine with later forecasts, but this could have an
impact on morning low temperatures on Friday.
With surface high pressure dominating the weather on Friday,
depending on morning cloud cover, should see chilly start with
temperatures in the 40s at most locations. In the meantime upper
level trough becomes established over the Great Lakes putting
forecast area in northwest flow pattern. Some indications that weak
low-level warm advection and isentropic ascent set up for Friday
night into Saturday morning. This could interact with subtle
shortwave/speed max rotating through mean trough over the Great Lakes
to provide for some elevated convection. At this time though it
appears best chance for activity would remain north and east of
forecast area so have trimmed PoPs a bit to into the slight chance
category.
MJM
Medium Range (Sunday through Wednesday)...
Later half of the forecast arrives Sunday with conditions across the
Central Plains warming back up after a few days of below to near
normal temperatures. The pattern across the nation Sunday will begin
rather benignly as it will still be relatively flat, though that
will quickly change as a trough shifts onshore across the Pacific
Coast, with a corresponding amplification of a ridge across the
Plains States. This amplification will bring above normal
temperatures back to the region, which should then prevail through
at least the first half of the work week.
Some focus will be needed for POPs late in the weekend and into the
beginning of the work week. Verity of mid-range models are
advertising a shortwave crossing the ridge axis Sunday, which
generates precipitation across our neck-of-the-woods Sunday and
Sunday night, with some models lingering precipitation into the day
Monday. Confidence on the specifics of the shortwave (like timing
and location) are fairly low, but given the nocturnal environment
that the expanding ridge will bring to the Plains, thoughts are this
shortwave my spawn a MCS Sunday night. Have limited chance POPs to
the overnight hours of Sunday with this expectation. Otherwise,
models also have a smattering of slight chance POPs in the coming
work week, but the output seems to suggest that they are having
issues with the generally warm and moist environment present under
the ridge. So, have trimmed much of the slight chance POPs from the
days after Monday.
Cutter
&&
.AVIATION...
For the 12Z TAFs...Low end MVFR clouds have spread south into the
terminals this morning in the cool air behind last night convective
system. Clouds are expected to lift and break up later this morning,
leaving VFR conditions to prevail through the rest of the daylight
hours. As clouds scatter later this morning, gusty winds will onset
from the north as boundary layer mixing ramps up. Gusty winds will
calm as the sun sets this evening. Otherwise, models indicate that
some low ceilings will rotate south across the terminals again
tonight. Confidence is not high enough to bite on the model guidance
that MVFR, and especially the sub-MVFR, ceilings will be moving in,
so have limited them in at 4000ft for tonight.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
607 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 606 AM CDT THU MAY 31 2012
LARGE AREA OF SHRA/TSRA OVER S CNTRL MO WILL CONTINUE TO MOVE EWD OVER
THE NEXT FEW HOURS. THE NORTHERN EDGE OF THIS MASS WILL PASS CLOSE
ENOUGH TO THE ST. LOUIS METRO AREA TAF SITES THROUGH 14Z TO
WARRANT EITHER VCSH OR A SHORT TEMPO GROUP FOR VFR -SHRA. RADAR IS
SHOWING A GRADUAL INCREASE IN AREAL COVERAGE OR SHRA/SCT TSRA FROM
NERN MO SWWD INTO W CNTRL MO THE PAST COUPLE OF HOURS IN RESPONSE
TO DEEPENING TROUGH OVER THE CENTRAL PLAINS. EXPECT THIS AREA TO
CONTINUE TO INCREASE IN SIZE AND MOVE EWD THROUGH THE MORNING.
HAVE INCLUDED ABOUT 4 HOURS OF -SHRA AT ALL OF THE TAF SITES THIS
MORNING/EARLY AFTERNOON TO ACCOUNT FOR A FAIRLY WIDESPREAD
COVERAGE OF RAIN DURING THIS PERIOD. INITIAL VFR CONDITIONS WILL
DECREASE TO MVFR WITH THE RAIN...WITH CIGS BECOMING MVFR/IFR AS
AREA OF LOW CIGS CURRENTLY OVER WRN IA/ERN NE/NERN KS MOVES SEWD
INTO THE AREA. THESE LOW CLOUDS WILL REMAIN OVER THE AREA UNTIL
TONIGHT WHEN THEY WILL BEGIN TO CLEAR OUT FROM WEST TO EAST.
SURFACE LOW OVER SW MO WILL MOVE ACROSS SRN MO CAUSING CURRENT
ELY WINDS TO BACK NWLY THIS MORNING AT ALL OF THE TAF SITES.
SPECIFICS FOR KSTL...MAY SEE SOME VFR -SHRA AT THE TERMINAL THROUGH
13Z ALONG NRN EDGE OF LARGE MASS OF -SHRA/-TSRA MOVES THROUGH SRN
MO. WILL LIKELY SEE -SHRA BETWEEN 16-20Z AS AREA OF RAIN FILLS IN
OVER THE NEXT FEW HOURS OVER WRN AND CNTRL MO THE NEXT FEW HOURS
AND MOVES EWD. CIGS WILL DECREASE FROM VFR TO MVFR AS THE RAIN
MOVES THROUGH...AND THEN REMAIN MVFR/POSSIBLY IFR AT TIMES LATE
THIS AFTERNOON AND EVENING AFTER THE RAIN EXITS THE REGION. VFR
CONDITIONS SHOULD RETURN AFT 06Z AS CLOUDS MOVE OUT OF THE AREA.
SFC WINDS WILL BACK FROM ELY TO NWLY QUICKLY BETWEEN 17-20Z AS
SFC LOW PASSES TO THE SOUTH.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1015 AM CDT THU MAY 31 2012
.UPDATE...
CURRENT FORECAST IS ON TRACK AT THIS TIME. NO UPDATES TO GRIDS AS
OF THIS MOMENT. SEE BELOW FOR UPDATED DISCUSSION ON SEVERE WEATHER
POTENTIAL.
RRH
&&
.DISCUSSION...
AS OF 10 AM...CONDITIONS ACROSS THE MIDSOUTH RANGED FROM MOSTLY
CLEAR ACROSS THE TENNESSEE RIVER VALLEY TO MOSTLY CLOUDY ACROSS
THE MAJORITY OF NORTHERN MISSISSIPPI AND EASTERN ARKANSAS. THE SUN
HAS BEEN OUT FOR MOST OF THE MORNING ACROSS WESTERN TENNESSEE AND
NORTHEASTERN MISSISSIPPI. SOME ADDITIONAL CLEARING IS VISIBLE ON
SATELLITE OVER WESTERN MISSISSIPPI...SOUTHERN ARKANSAS...AND
NORTHERN LOUISIANA. A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
OVER NORTHEASTERN ARKANSAS BUT THESE STORMS HAVE POSED NO THREAT
OF SEVERE WEATHER SO FAR.
THE INSTABILITY WILL GRADUALLY INCREASE THROUGH THE REST OF THE
MORNING AND EARLY AFTERNOON HOURS IN AREAS WHERE CLOUD COVER HAS
CLEARED. MODELS ARE INDICATING CAPE VALUES BETWEEN 2000 J/KG TO
3000 J/KG WILL BE POSSIBLE BY EARLY THIS AFTERNOON. LATEST RUN OF
THE NAM MODEL HAS INITIALIZED WELL AND IS HANDLING THE CURRENT
CONVECTION OVER MISSOURI AND TEXAS WITH GOOD ACCURACY. GOING BY
THIS MODEL...CONVECTION WILL RAPIDLY INCREASE ACROSS ARKANSAS
BETWEEN THE HOURS OF NOON AND 2 PM. THIS AREA OF THUNDERSTORMS
WILL MOVE ACROSS THE MIDSOUTH THIS AFTERNOON AND CLEAR THE REGION
BY THIS EVENING. A FEW SHOWERS MAY DEVELOP ALONG THE COLD FRONT
THIS EVENING BUT THE SEVERE WEATHER SHOULD HAVE CLEARED OUT BY
THEN. THE MAIN THREATS FOR THIS AFTERNOONS STORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. TORNADOES DO NOT SEEM LIKELY ACROSS THE
MAJORITY OF THE MIDSOUTH AT THIS TIME DUE TO A UNIDIRECTIONAL WIND
FIELD. HOWEVER...AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM...AN
ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT FOR NORTHWEST
TENNESSEE AND THE MISSOURI BOOTHEEL. THIS IS BECAUSE THE SURFACE
WINDS WILL REMAIN BACKED TO THE SOUTHEAST A LITTLE LONGER ACROSS
THIS AREA OF CONCERN THAN THE REST OF THE MIDSOUTH. SOUNDINGS FOR
TODAY SHOW DRIER AIR IN THE LOWER ATMOSPHERE WITH DOWNDRAFT CAPE
VALUES AS HIGH AS 1000 J/KG TO 1500 J/KG...WHICH WOULD INDICATE A
BETTER POTENTIAL FOR DAMAGING WINDS. STEEP LOW LEVEL LAPSE RATES
WILL ALLOW FOR STRONG UPDRAFTS...WHICH WILL SOMEWHAT INCREASE THE
HAIL POTENTIAL.
RRH
&&
PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
12Z TAF CYCLE
A DIFFICULT FORECAST ONCE AGAIN FOR TODAY AS MULTIPLE MESOSCALE
FEATURES MAY DOMINATE THE EVOLUTION OF THE OVERALL PATTERN OVER
THE NEXT 24 HOURS. THIS RESULTS IN LOWER THAN PREFERRED FORECAST
CONFIDENCE.
A DECAYING MCS CONTINUES TO MOVE EAST WITH AN OUTFLOW BOUNDARY
THAT SHOULD WEAKEN AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST BY MID MORNING. LATEST HIGH RESOLUTION RAPID REFRESH MODEL
RUN WHICH HANDLED OVERNIGHT CONVECTION BEST INDICATES AT LEAST
SCATTERED DEVELOPMENT ALONG THIS EASTWARD MOVING OUTFLOW BOUNDARY.
PLAN TO MAINTAIN A VCTS BEGINNING AT 14Z AT JBR AND CONTINUING
INTO AFTERNOON POINTS FURTHER EAST. WINDS SHOULD INITIALLY BE
SOUTHEASTERLY AND LIGHT BUT VEER TO THE SOUTH AND EVENTUALLY
SOUTHWEST BY THIS AFTERNOON AND INCREASE IN INTENSITY.
AT THIS TIME...IT APPEARS THAT THE GREATEST THUNDERSTORM POTENTIAL
WILL HOLD OFF UNTIL THIS AFTERNOON AS A RATHER WELL DEFINED
SHORTWAVE OVER EASTERN OKLAHOMA THIS MORNING MOVES EAST INTO THE
REGION. HAVE MAINTAINED TEMPO GROUPS FOR STORMS THROUGH THE
AFTERNOON AND EARLY EVENING HOURS FROM WEST TO EAST AT ALL SITES.
THUNDERSTORM POTENTIAL SHOULD END FROM WEST TO EAST DURING THE
EVENING HOURS AS A COLD FRONT SWEEPS EAST ACROSS THE AREA. WINDS
SHOULD COME OUT OF THE NORTHWEST AND NORTH WITH SOME GUSTS
OVERNIGHT BEHIND THE FRONTAL PASSAGE.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
715 AM CDT THU MAY 31 2012
.UPDATE...
UPDATED FOR THE 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
12Z TAF CYCLE
A DIFFICULT FORECAST ONCE AGAIN FOR TODAY AS MULTIPLE MESOSCALE
FEATURES MAY DOMINATE THE EVOLUTION OF THE OVERALL PATTERN OVER
THE NEXT 24 HOURS. THIS RESULTS IN LOWER THAN PREFERRED FORECAST
CONFIDENCE.
A DECAYING MCS CONTINUES TO MOVE EAST WITH AN OUTFLOW BOUNDARY
THAT SHOULD WEAKEN AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST BY MID MORNING. LATEST HIGH RESOLUTION RAPID REFRESH MODEL
RUN WHICH HANDLED OVERNIGHT CONVECTION BEST INDICATES AT LEAST
SCATTERED DEVELOPMENT ALONG THIS EASTWARD MOVING OUTFLOW BOUNDARY.
PLAN TO MAINTAIN A VCTS BEGINNING AT 14Z AT JBR AND CONTINUING
INTO AFTERNOON POINTS FURTHER EAST. WINDS SHOULD INITIALLY BE
SOUTHEASTERLY AND LIGHT BUT VEER TO THE SOUTH AND EVENTUALLY
SOUTHWEST BY THIS AFTERNOON AND INCREASE IN INTENSITY.
AT THIS TIME...IT APPEARS THAT THE GREATEST THUNDERSTORM POTENTIAL
WILL HOLD OFF UNTIL THIS AFTERNOON AS A RATHER WELL DEFINED
SHORTWAVE OVER EASTERN OKLAHOMA THIS MORNING MOVES EAST INTO THE
REGION. HAVE MAINTAINED TEMPO GROUPS FOR STORMS THROUGH THE
AFTERNOON AND EARLY EVENING HOURS FROM WEST TO EAST AT ALL SITES.
THUNDERSTORM POTENTIAL SHOULD END FROM WEST TO EAST DURING THE
EVENING HOURS AS A COLD FRONT SWEEPS EAST ACROSS THE AREA. WINDS
SHOULD COME OUT OF THE NORTHWEST AND NORTH WITH SOME GUSTS
OVERNIGHT BEHIND THE FRONTAL PASSAGE.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
338 PM MDT THU MAY 31 2012
.SHORT TERM...
(TONIGHT AND TOMORROW)
CURRENTLY...
AS OF 2 PM...ISOLATED SHOWERS WERE DEVELOPING OVER THE SANGRES AND
SAN JUAN MTNS. OTHERWISE...SKIES WERE MOSTLY CLEAR OVER THE
REMAINDER OF THE REGION. TEMPS OVER THE REGION WERE ON THE COOLER
SIDE...WITH THE SAN LUIS VALLEY AND THE PLAINS IN THE 70-75 RANGE. A
WEAK DIURNAL WIND REGIME WAS DEVELOPING OVER THE AREA.
REST OF AFTERNOON/EVENING...
BEST CHANCE OF ISOLD TSRA ACTIVITY WILL BE OVER THE MTNS...WITH THE
BEST CHANCE OF SOME STRONGER STORMS OVER THE S SANGRES AND RATON
MESA REGION. BOTH LOCAL WRF AND HRRR ARE SHOWING HEAVIER QPF
BREAKING OUT THESE REGIONS DURING THIS TIME PD. ONCE ACTIVITY GETS
GOING...IT SHOULD MOVE IN A SE DIRECTION GIVEN THE NW FLOW ALOFT.
MARGINAL SVR HAIL AND SOME STRONGER GUSTS COULD OCCUR WITH STORMS
GIVEN THE SHEAR IN PLACE.
ONE ISSUE I AM NOT TOO CONFIDENT ABOUT IS SOME CONVECTION MOVING
ACROSS THE FAR E PLAINS THIS EVENING. LATEST HRRR IS HINTING AT THIS
BUT OTHER GUIDANCE KEEPS THE PLAINS ON THE DRY SIDE. FOR NOW WILL
KEEP SILENT POPS OVER THIS REGION AND ALLOW EVENING SHIFT TO ADJUST
POPS IF WARRANTED.
TONIGHT...
DRY CONDITIONS ANTICIPATED DURING THE EARLY MORNING HOURS.
SIMULATIONS DO SHOW A MCS DEVELOPING OVER W NE/SW NE MOVING EAST
LATE TONIGHT...BUT BELIEVE THIS ACTIVITY SHOULD REMAIN OUT OF OUR
CWA AS IT MOVES SE ACROSS W KS.
TOMORROW...
COOL FRONT WILL MOVE ACROSS THE REGION TOMORROW MORNING ASSOCIATED
WITH AFORMENTIONED MCS. WE COULD SEE SOME GUSTY N WINDS...25-30 MPH
IN THE MORNING...OVER THE PLAINS AND POSSIBLY E SXNS OF EL PASO
COUNTY. WINDS WILL QUICKLY TRANSISTION TO AN UPSLOPE COMPONENT...AND
BEST CHANCE OF POPS ONCE AGAIN WILL BE OVER E FACING SLOPES OF E
MTNS. DEPENDING IF THE FRONT STALLS ALONG THE CO/NM BORDER...WE MAY
SEE A BETTER CHANCE OF POPS ALONG THE RATON MESA REGION LATER IN THE
DAY. TEMPS OVERALL SHOULD BE ABOUT 4-8F WARMER THAN TODAY.
.LONG TERM...
(FRIDAY NIGHT THROUGH NEXT THURSDAY)
ISOLATED TSRA FRI EVENING SHOULD SHIFT SOUTHEAST INTO THE TEXAS
PANHANDLE OVERNIGHT...AS DEEPER MOISTURE REMAINS JUST SOUTH OF THE
AREA. ON SAT...NICE SOUTHEAST UPSLOPE FLOW DEVELOPS OVER THE
PLAINS...WHICH SHOULD ADVECT A MORE MOIST AND UNSTABLE AIR MASS
INTO THE AREA BY AFTERNOON. MODEL PERFORMANCE THE PAST COUPLE DAYS
SUGGESTS GFS DEWPOINTS APPROACHING 60F ARE SLIGHTLY
OVERDONE...THOUGH EVEN GOING WITH LOWER NAM NUMBERS IN THE 40S TO
50S YIELDS CAPES WELL ABOVE 1000 J/KG ACROSS MUCH OF THE EASTERN
PLAINS EAST OF I-25 BY LATE IN THE DAY. STILL APPEARS WEAK WAVE
WILL WIGGLE EAST THROUGH THE RIDGE AS WELL...ENHANCING UPWARD
MOTION OVER THE AREA INTO SAT EVENING. SOME THREAT OF A SEVERE
STORM OR TWO OVER THE PLAINS NEAR THE KS BORDER...WHERE DEEPER
INSTABILITY AND 0-6KM SHEAR OF 30-40 KNOTS COINCIDE. THUS
CONTINUED TO NUDGE POPS UPWARD SAT AFTERNOON AND EVENING...WITH AT
LEAST A SCATTERED MENTION IN MOST EASTERN MOUNTAIN AND PLAINS
ZONES. SUNDAY STILL LOOKS DRIER AS DEEPER MOISTURE IS PUSHED
EAST...THOUGH LATEST MODELS KEEP SURFACE DEWPOINTS HIGHER THAN
PREVIOUS RUNS...WHICH MAY LEAD TO SLIGHTLY BETTER CONVECTIVE
COVERAGE THAN EARLIER THOUGHT. STILL DON`T SEE MUCH MORE THAN
ISOLATED TSRA OVER MAINLY THE MOUNTAINS...ESPECIALLY AS STEERING
FLOW IS WEAK AS UPPER RIDGE IS OVERHEAD. SHOULD SEE MAX TEMPS STAY
WARM BOTH SAT AND SUN AS 700 MB THERMAL RIDGE REMAINS IN PLACE
ACROSS THE STATE.
UPPER RIDGE AXIS DRIFTS VERY SLOWLY EASTWARD EARLY NEXT WEEK AS
DEEP TROUGH MOVES ONSHORE OVER THE PACIFIC NORTHWEST. BOTH GFS
AND ECMWF ALLOW LOW LEVEL MOISTURE TO CREEP BACK WESTWARD MON IN
THE ABSENCE OF STRONG FLOW ALOFT...WITH BOTH MODELS SUGGESTING AN
UPTURN IN TSRA OVER THE EASTERN HALF OF THE AREA MON
AFTERNOON/EVENING. WEAK UPPER LOW TRAPPED UNDER THE RIDGE MAY ALSO
AID IN UPWARD MOTION...AT LEAST THROUGH MON EVENING. UPPER TROUGH
INCHES CLOSER TO THE REGION TUE/WED...WITH DRYLINE SHARPENING UP
OVER THE EASTERN PLAINS. MAY THUS SEE DAILY ROUNDS OF TSRA ALONG
AND EAST OF THE DRYLINE EACH AFTERNOON TUE-THU...WHILE MOUNTAINS
UNFORTUNATELY STAY MAINLY DRY AND INCREASINGLY BREEZY THROUGH MID-
WEEK. --PETERSEN
&&
.AVIATION...VFR CONDITIONS ANTICIPATED DURING THE NEXT 24H AT
KCOS...KPUB AND KALS. THERE IS A VERY SLIGHT CHANCE OF A PASSING
TSRA AT KCOS LATE THIS AFTERNOON AND EARLY EVENING...AND LATE
TOMORROW AFTERNOON.
A WEAK COOL FRONT WILL CROSS THE KCOS REGION TOWARDS SUNRISE FRIDAY.
BRIEF WIND GUSTS TO 20 MPH MAY OCCUR AFTER FROPA. NO OTHER SENSIBLE
WX IS ANTICIPATED WITH THE FROPA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34/10
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
608 PM EDT THU MAY 31 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL TRACK ACROSS THE OHIO VALLEY AND
INTO THE EASTERN GREAT LAKES FRIDAY INTO SATURDAY, DRAGGING A COLD
FRONT ACROSS THE AREA FRIDAY NIGHT. WEAK HIGH PRESSURE WILL TRY TO
BUILD IN FROM THE SOUTH FOR SATURDAY INTO EARLY SUNDAY BEFORE LOW
PRESSURE TO OUR EAST DEEPENS AND SENDS WEAK DISTURBANCES TOWARD OUR
AREA THROUGH TUESDAY. ANOTHER AREA OF LOW PRESSURE TRACKING ACROSS
THE UPPER PLAINS WILL MOVE ACROSS THE OHIO AND TENNESSEE VALLEYS
MONDAY AND TUESDAY BUT WILL LIKELY REMAIN TO OUR SOUTH AS IT IS
SUPPRESSED BY THE LOW OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NO BIG CHANGES WITH THIS ESTF UPDATE. WE DID USE A COMBINATION OF
THE HIRES WRF-ARW AND WRF-NMM TO ADJUST THE SLOW PROGRESSION OF
THE SEA BREEZE INLAND. BASED ON CURRENT PERFORMANCE (AND HOPEFULLY
FUTURE TRENDS) THEY WERE HANDLING IT BETTER THAN THE RAP OR HRRR.
OTHER THAN SOME INCREASE IN HIGH CLOUDINESS OVERNIGHT AS THE MID
LEVEL RIDGE AXIS ARRIVES, WE SHOULD HAVE FAIR WEATHER IN THE NEAR
TERM. WINDS WILL GO LIGHT FOR MOST OF THE NIGHT, BUT EASTERLY
WINDS MAY BEGIN TO PICK UP JUST PRIOR TO DAYBREAK. TEMPERATURES
WERE A BLEND OF GUIDANCE AND CONTINUITY. DEW POINTS OVER MOST
LOCATIONS HAD DROPPED LATE THIS AFTERNOON AND THERE MAY BE SOME
RADIATING THIS EVENING, BUT THE GROUND IS GETTING WARM AND THE
NIGHTS ARE RATHER SHORT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WARM FRONT WILL TRY TO PUSH ACROSS THE AREA ON FRIDAY WHILE A COLD
FRONT APPROACHES FROM THE WEST. THERE IS SOME ISENTROPIC LIFT AHEAD
OF THE WARM FRONT, ALTHOUGH SATURATION TAKES A WHILE TO OCCUR. THE
MID LEVEL TROUGH AXIS MOVING INTO THE UPPER OHIO RIVER VALLEY, THE
TRIPLE POINT MOVING INTO CENTRAL PA AND THE APPROACHING COLD FRONT
LOOK MORE LIKE THE CUES FOR SIGNIFICANT RAINFALL. MOISTURE WILL BE
ON THE INCREASE THROUGH THE AFTERNOON, AND WE SEE AN APPROACHING
UPPER JET, SOME GOOD MID LEVEL Q-VECTOR CONVERGENCE, LOWER LEVEL
FRONTOGENESIS, AND DIFFERENTIAL DIVERGENCE BEGINNING TO COME
TOGETHER VERY NEAR US. INSTABILITY INVADES BEHIND THE WARM FRONT,
AND THAT LIKELY FAVORS SOUTHERN AND WESTERN PARTS OF OUR AREA. THERE
IS VERY GOOD BULK SHEAR AS ONE APPROACHES THE TRIPLE POINT. WE HAVE
NO ENHANCED WORDING THROUGH THE SHORT TERM, BUT STRONG STORMS
CERTAINLY MAY BE APPROACHING OUR WESTERN ZONES BY LATE FRIDAY
AFTERNOON. OUR POPS BY THE END OF THE DAY RANGE FROM LIKELY WEST TO
SLIGHT CHANCE OFF THE COAST. TEMPERATURES ARE VERY CLOSE TO
CONTINUITY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL MOVE THROUGH THE REGION ON FRIDAY NIGHT AS THE
STRONG PARENT LOW PRESSURE SYSTEM MOVES INTO SOUTHEASTERN CANADA AND
MOVES VERY LITTLE THROUGH EARLY SUNDAY. SURFACE LOW PRESSURE
DEVELOPS ALONG A BOUNDARY JUST TO OUR NORTH AND MOVES OVER THE NEW
ENGLAND COAST WHILE SLOWLY DRIFTING EASTWARD. A WEAK AREA OF HIGH
PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH FOR SATURDAY AND EARLY
SUNDAY. THE SOUTHEASTERN CANADIAN LOW WILL THEN BEGIN TO MOVE
SOUTHEAST ON SUNDAY AND EVENTUALLY ABSORB THE NEW ENGLAND COASTAL
LOW. THIS MOVEMENT WILL THEN DRAG A BOUNDARY ACROSS THE AREA ON
SUNDAY NIGHT. THE LOW SEEMS TO SET UP SHOP OFF THE NEW ENGLAND COAST
THROUGH ABOUT TUESDAY. ENERGY ROTATING AROUND THIS CLOSED LOW WILL
BRING UNSETTLED WEATHER ACROSS OUR AREA THROUGH ABOUT MIDWEEK.
ANOTHER AREA OF LOW PRESSURE TRACKING ACROSS THE UPPER PLAINS WILL
MOVE ACROSS THE OHIO AND TENNESSEE VALLEYS MONDAY AND TUESDAY BUT
WILL LIKELY REMAIN TO OUR SOUTH AS IT IS SUPPRESSED BY THE LOW OFF
THE NEW ENGLAND COAST. THE STRONGER SURFACE LOW TO OUR NORTHEAST
FINALLY STARTS TO MOVE EASTWARD ON WEDNESDAY. THE UPPER LEVEL LOW
SLOWLY MOVES TO EAST BUT REMAINS NEARBY THROUGH THE END OF NEXT
WEEK.
FOR FRIDAY NIGHT WE MAY SEE HEAVY RAIN AND GUSTY WINDS AS
THUNDERSTORMS MOVE THROUGH AHEAD OF AND ALONG THE FRONTAL PASSAGE.
AREAS THAT HAVE SEEN COPIOUS AMOUNTS OF RAIN OVER THE PAST WEEK MAY
SEE SOME MORE AS PRECIPITABLE WATER VALUES REMAIN FAIRLY HIGH. THIS
MAY CONTRIBUTE TO LOCALIZED FLOODING ISSUES SO EXERCISE CAUTION IF
OUT WHEN STORMS MOVE THROUGH. WE WILL CONTINUE TO MONITOR THE HEAVY
RAINFALL THREAT.
AN UNSETTLED PERIOD OF WEATHER IS EXPECTED THROUGH THE EXTENDED AND
WITH THE EXCEPTION OF SATURDAY, WE CANNOT RULE OUT THE POSSIBILITY
OF SHOWERS AND/OR THUNDERSTORMS TO OCCUR. CONFIDENCE IS NOT
PARTICULARLY HIGH AT THIS POINT SO WE HAVE KEPT POPS MAINLY IN THE
CHC/SCHC RANGE.
OVERALL THOUGH, WE WILL SEE A COOLING TREND AS COOLER AIR GETS
PUSHED DOWN ACROSS THE REGION THROUGH THE PERIOD. WE WENT WITH A
BLEND OF HPC GUIDANCE AND CONTINUITY FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE FORECAST VFR CONDITIONS THROUGH THE SHORT TERM, ALTHOUGH
CONDITIONS MAY BEGIN TO DETERIORATE IN CONVECTION LATE IN THE
AFTERNOON WEST.
FOR TONIGHT, WINDS SHOULD BE LIGHT UNTIL AROUND DAYBREAK WHEN THEY
WILL BEGIN TO DEVELOP AN EASTERLY COMPONENT AND APPROACH 10 KT.
HIGH CLOUDS WILL BEGIN TO INVADE AND WE DON`T EXPECT VISIBILITY
ISSUES. CLOUDS WILL INCREASE AND CEILINGS WILL LOWER DURING THE DAY
ON FRIDAY. WINDS MAINLY WILL BE FROM THE SOUTHEAST AND WILL DEVELOP
SOME GUSTS OF AROUND 20 KT.
CONVECTION IS MOST LIKELY IN THE AFTERNOON WEST, AND IT MAY CARRY
SOME STRONG WIND GUSTS AND IFR CONDITIONS IF IT DEVELOPS.
OUTLOOK...
FRIDAY NIGHT...SHOWERS AND THUNDERSTORMS DURING THE EVENING AND
OVERNIGHT HOURS WILL CAUSE CONDITIONS TO DETERIORATE TO MVFR/IFR.
THERE IS ALSO THE POTENTIAL FOR LOCAL DOWNPOURS AND GUSTY WINDS.
SOUTHEAST WINDS AROUND 10 TO 15 KNOTS WILL TURN TO THE SOUTH AND
THEN SOUTHWEST DURING THE LATE EVENING BEFORE SHIFTING TO WEST
TOWARD MORNING.
SATURDAY...BECOMING VFR BY EARLY SATURDAY MORNING WITH WEST WINDS 10
TO 15 KNOTS. WINDS MAY BECOME GUSTY DURING THE DAY.
SUNDAY...VFR CONDITIONS WITH WEST WINDS AROUND 10 KNOTS. SHOWERS ARE
POSSIBLE LATER IN THE DAY AND COULD CAUSE WHICH COULD CAUSE LOWER
VISIBILITIES AND/OR CEILINGS TO OCCUR.
MONDAY...VFR WITH A WEST TO NORTHWEST WIND AROUND 10 KNOTS.
AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE WHICH COULD CAUSE
LOWER VISIBILITIES AND/OR CEILINGS TO OCCUR.
TUESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SHOWERS AND POSSIBLY A
THUNDERSTORM POSSIBLE, MAINLY TOWARD THE AFTERNOON HOURS. NORTH TO
NORTHEAST WINDS AROUND 10 KNOTS.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE FORECAST UNTIL THE EARLY EVENING ON
FRIDAY. TONIGHT SHOULD SEE LIGHT WINDS DEVELOPING AN EASTERLY
COMPONENT AND THEN INCREASING BY DAYBREAK. SEAS SHOULD REMAIN AT OR
BELOW 3 FT. THEN, EAST TO SOUTHEAST WINDS WILL CONTINUE TO INCREASE
DURING THE DAY ON FRIDAY UNTIL GUSTS TO 25 KT AND SEAS OF 5 FT
DEVELOP LATE.
OUTLOOK...
A STRONG COLD FRONT WILL CROSS THE AREA WATERS ON FRIDAY NIGHT
ACCOMPANIED BY STRONG GUSTY WINDS, RAIN AND POSSIBLY SOME
THUNDERSTORMS. ALTHOUGH AN INVERSION IS PRESENT ON MODEL SOUNDINGS,
THERE APPEARS TO BE A STRONG ENOUGH FLOW TO SUSTAIN SMALL CRAFT
ADVISORY GUSTS. THE STRONG SOUTH TO SOUTHEASTERLY FLOW AHEAD OF THE
FRONT WILL BRING GUSTS AROUND 25-30 KNOTS ALONG THE OCEAN AND 20-25
KNOTS IN THE DELAWARE BAY. SOME ENHANCEMENT ACROSS THE MOUTH OF THE
DELAWARE BAY COULD ALSO INCREASE GUSTS FOR A PERIOD AS WELL AHEAD OF
THE FRONT. SEAS ALSO BEGIN TO INCREASE IN THE SOUTHERLY FLOW AND
COULD REACH 5 FEET BY FRIDAY NIGHT. AS A RESULT, WE HAVE ISSUED A
SMALL CRAFT ADVISORY ON THE OCEAN FRONT FROM 6PM FRIDAY THROUGH 2PM
SATURDAY. A SMALL CRAFT FOR THE DELAWARE BAY WILL RUN FROM 6PM
FRIDAY THROUGH 10AM SATURDAY.
AS THE FRONT MOVES THROUGH THE WINDS TURN TO THE SOUTH THEN
SOUTHWEST AND EVENTUALLY BECOME MORE WESTERLY BY SATURDAY MORNING.
WINDS WILL THEN REMAIN WESTERLY THROUGH THE WEEKEND AND INTO THE NEW
WEEK. SEAS AND WINDS SUBSIDE ON SATURDAY AND WE DO NOT ANTICIPATE
THE NEED FOR ANY SMALL CRAFT ADVISORY HEADLINES FROM SATURDAY
THROUGH THE START OF THE NEW WEEK.
&&
.TIDES/COASTAL FLOODING...
DEPARTURES OF APPROXIMATELY THREE-QUARTERS OF A FOOT ARE NECESSARY
TO BEGIN MINOR TIDAL FLOODING ALONG OUR ATLANTIC COASTLINE, RARITAN
BAY, DELAWARE BAY AND THE TIDAL DELAWARE RIVER WITH THE HIGHER HIGH
TIDE FROM EARLY FRIDAY EVENING THROUGH MIDNIGHT. THE INCREASE IN
EASTERLY WINDS COULD MAKE IT HAPPEN, AND WE WILL MENTION THE
POSSIBILITY OF MINOR TIDAL FLOODING OVER THOSE SHORELINES IN THE
HWO.
THE MARYLAND EASTERN SHORE WOULD NEED DEPARTURES IN EXCESS OF ONE
FOOT, AND WE PRESENTLY DON`T ANTICIPATE ANY PROBLEMS THERE.
THE NEXT TIME FRAME OF CONCERN IS THE SUNDAY THROUGH TUESDAY HIGH
TIDE CYCLES. WITH THE FULL MOON EXPECTED ON MONDAY AND HIGHER
ASTRONOMICAL TIDES, LOCATIONS ALONG OUR ATLANTIC COASTLINE, RARITAN
BAY, DELAWARE BAY AND THE TIDAL DELAWARE RIVER MAY EXPERIENCE
MINOR TIDAL FLOODING. ASTRONOMICAL HIGH TIDES ARE ONLY RUNNING
0.2-0.4 TENTHS BELOW MINOR COASTAL FLOODING THRESHOLDS SO WE WILL
KEEP AN EYE ON THIS OVER THE NEXT FEW DAYS. ONE ITEM IN OUR FAVOR
APPEARS TO BE AN OFFSHORE FLOW, WHICH WILL HELP TO LIMIT POTENTIAL
FOR FLOODING.
AGAIN, WITH DEPARTURES AROUND ONE FOOT, NO PROBLEMS ARE
ANTICIPATED ALONG THE EASTERN SHORE OF MARYLAND ON THE CHESAPEAKE
BAY AT THIS TIME.
&&
.RIP CURRENTS...
WITH A FORECAST INCREASE OF SOUTHEAST WINDS DURING THE AFTERNOON
ON FRIDAY AND WITH US GETTING CLOSER TO THE FULL MOON, OUR IN HOUSE
PROCEDURE TAKES NEW JERSEY INTO A MODERATE RISK OF RIP CURRENTS AND
PLACES DELAWARE BEACHES JUST SHORT. WITH THE WINDS EXPECTED TO
INCREASE IN DELAWARE FIRST, WE DECIDED TO OUTLOOK ALL AREAS FOR A
MODERATE RISK ON FRIDAY. PLEASE LOOK FOR UPDATED INFORMATION ON
FRIDAY MORNING.
&&
.CLIMATE...
IN SPITE OF ANOTHER LA NINA WINTER AND A MILD ONE AT THAT, BOTH
APRIL AND MAY WERE UNSEASONABLY WARM AGAIN FOR THE FOURTH
CONSECUTIVE SPRING. SINCE 1872, THIS COMBINATION HAS OCCURRED ONLY
TWENTY-ONE TIMES, BUT NOW NINE TIMES SINCE 1990. WE HAVE ALSO HAVE HAD
NINE CONSECUTIVE MONTHS OF ABOVE NORMAL TEMPERATURES. BY OUR
CATEGORY DEFINITION UNSEASONABLY COOL/NORMAL/UNSEASONABLY WARM MONTHS
ARE DIVIDED INTO THIRDS. THIS IS ONLY THE 5TH TIME THIS HAS OCCURRED
AFTER A LA NINA WINTER AND GIVES US A LONE FOURSOME OF ANALOGS FOR
THIS UPCOMING SUMMER. THE SUMMER OF 1985 WAS THE LONE COOL ONE IN
THE FOURSOME AND HAS WEIGHED DOWN THE ANALOG AVERAGE. WE`LL FIND OUT
ON SEPTEMBER 1ST IF THIS WAS A GOOD OR BAD INCLUSION. THE OTHER
THREE SUMMERS WERE WARMER THAN NORMAL EVEN USING THE CURRENT
1981-2010 NORMALS. THAT THREESOME AVERAGE WAS 77.0 DEGREES. WE ARE
CERTAIN SOMEONE WILL NOTICE THAT ALL OF THESE ANALOG SUMMERS SAW
TROPICAL ACTIVITY THAT AFFECTED OUR AREA: CONNIE AND DIANE IN 1955,
GLORIA IN 1985, ALLISON IN 2001 AND IRENE IN 2011. WITH THREE OF
THEM OCCURRING IN AUGUST, THEY SKEWED THE SUMMER PRECIPITATION
AVERAGE TO WET. THE PRECIPITATION ASSOCIATED WITH ALLISON WAS NOT
ENOUGH TO OFFSET A VERY DRY JULY AND AUGUST.
YEAR JUNE AVG JULY AVG AUGUST AVG SUMMER AVG SUMMER PCPN
1955 69.2 81.4 78.1 76.2 14.80
1985 68.8 75.4 74.1 72.8 9.36
2001 75.2 75.4 79.9 76.8 8.20
2011 75.4 82.4 76.1 78.0 22.02
AVG 72.2 78.7 77.1 76.0 13.60
1981-2010 NML 73.3 78.1 76.6 76.0 11.28
THE OFFICIAL CPC OUTLOOK FOR THIS SUMMER IS FOR A GREATER CHANCE OF
IT BEING WARMER THAN NORMAL IN THE SOUTHERN PART OF OUR CWA AND
EQUAL CHANCES OF IT BEING EITHER WARMER OR COOLER THAN NORMAL IN THE
NORTHERN PART OF OUR CWA. THE PRECIPITATION OUTLOOK IS FOR EQUAL
CHANCES OF IT BEING EITHER DRIER OR WETTER THAN NORMAL.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM FRIDAY TO 2 PM EDT SATURDAY FOR
ANZ450>455.
SMALL CRAFT ADVISORY FROM 6 PM FRIDAY TO 10 AM EDT SATURDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...MEOLA
AVIATION...DELISI/MEOLA
MARINE...DELISI/MEOLA
TIDES/COASTAL FLOODING...MEOLA/DELISI
RIP CURRENTS...GIGI
CLIMATE...GIGI
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1258 PM CDT THU MAY 31 2012
.UPDATE...
ISSUED AT 1108 AM CDT THU MAY 31 2012
SHOWERS...ALONG WITH SCATTERED THUNDERSTORMS...WILL PERSIST ALONG
AND ESPECIALLY EAST OF THE MISSISSIPPI RIVER INTO THE MID
AFTERNOON HOURS. ALTHOUGH THERE HAS BEEN A DEFINITE EWD PUSH TO
THE BACK EDGE OF THE RAIN AREA...EXPECTING ADDITIONAL DEVELOPMENT
TO OCCUR AS SHORTWAVE OVER NW MO DIGS INTO MID MISSISSIPPI VALLEY.
IT STILL APPEARS THAT ANY SEVERE WEATHER POTENTIAL WILL BE
CONFINED TO A VERY NARROW WINDOW OF OPPORTUNITY IN OUR FAR SE
COUNTIES. PROPAGATION OF SURFACE BOUNDARY...ALONG WITH CURRENTLY
RAIN-COOLED AIRMASS IN OUR SE...CERTAINLY SUGGESTS THE GREATER
THREAT WILL BE EAST OF OUR CWA.
TEMP TRENDS STILL LOOKING REASONABLE...ALTHOUGH DID HAVE TO UP
MAX TEMPS OVER MID MO AS BREAK IN THE CLOUDS HERE HAS ALLOWED
TEMPS TO JUMP INTO THE LOWER 70S. THIS WARMUP SHOULD BE FAIRLY
BRIEF...AS CLOUDS AND CAA WILL DROP TEMPS BACK INTO THE 60S FOR
MUCH OF THE AFTERNOON.
TRUETT
&&
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 1235 PM CDT THU MAY 31 2012
FA WILL CERTAINLY BE EXPEREINCING ATYPICAL AVIATION CONDITIONS
FOR LATE MAY AND EARLY JUNE OVER THE NEXT 12-18 HOURS. SURFACE LOW
IS APPROACHING STL AREA ATTM...WITH SCT-BKN CLDS BTWN 1500-2000
FEET IN THE PROXIMITY OF THE LOW. MEANWHILE...A MUCH MORE
EXTENSIVE AREA OF MVFR...AND OCNL IFR...CIGS LOCATED TO THE N AND
NW OF THE LOW. THIS CLOUD DECK SHOULD PERSIST INTO THE EARLY
EVENING AT BOTH COU AND UIN...AND IS EXPECTED TO ROTATE INTO THE
STL BY MID AFTERNOON AS THE SURFACE LOW PUSHES INTO IL. STILL
EXPECTING SPOTTY SHOWERS ALONG THE MISSISSIPPI RIVER THIS
AFTERNOON...WITH THE THREAT OF STRONGER CONVECTION FOCUSED TO THE
SE OF THE STL AREA. 12Z MOS OUTPUT...AS WELL AS 12Z FORECAST
SOUNDINGS...ARE STILL STRONGLY SUGGESTING WIDESPREAD IFR CIGS
DEVELOPING EARLY THIS EVENING. AS MENTIONED AT THE START OF THE
AFD THIS WOULD BE HIGHLY UNUSUAL...BUT GIVEN THE UNSEASONAL NATURE
OF THIS SYSTEM TREND SEEMS REASONABLE. DRIER AIR ADVECTING INTO
THE BACK SIDE OF THE SURFACE SYSTEM SHOULD SLOWLY ERODE THIS LOWER
DECK LATE TONIGHT AND EARLY FRIDAY MORNING...MODELS DO NOT HAVE A
GOOD HANDLE ON THIS TREND SO FORECAST REPRESENTS A VERY FIRST
ROUGH APPROXIMATION ON WHEN CLEARING MAY OCCUR.
SPECIFICS FOR KSTL...
AS MENTIONED ABOVE...SCT-BKN CU/CUFRA WILL GIVE WAY TO A MORE
EXTENSIVE AREA OF MVFR CIGS...WITH CIGS BETWEEN 1500-2000 FT
BECOMING COMMON FROM MID/LATE AFTERNOON INTO EARLY EVENING. MOS
AND FORECAST SOUNDINGS THEN SUGGEST THAT THESE CIGS WILL LOWER
BELOW 1KFT DURING THE EVENING...WITH THESE IFR CIGS THEN
PERSISTING INTO EARLY FRIDAY MORNING. LOOKS LIKE THE MOST ROBUST
CONVECTION THIS AFTERNOON WILL OCCUR/REDEVELOP JUST TO THE SE OF
THE AREA...WITH GENERALLY SPOTTY LIGHT SHRA IN THE STL TAF VICINITY.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1119 AM CDT THU MAY 31 2012
.UPDATE...
ISSUED AT 1108 AM CDT THU MAY 31 2012
SHOWERS...ALONG WITH SCATTERED THUNDERSTORMS...WILL PERSIST ALONG
AND ESPECIALLY EAST OF THE MISSISSIPPI RIVER INTO THE MID
AFTERNOON HOURS. ALTHOUGH THERE HAS BEEN A DEFINITE EWD PUSH TO
THE BACK EDGE OF THE RAIN AREA...EXPECTING ADDITIONAL DEVELOPMENT
TO OCCUR AS SHORTWAVE OVER NW MO DIGS INTO MID MISSISSIPPI VALLEY.
IT STILL APPEARS THAT ANY SEVERE WEATHER POTENTIAL WILL BE
CONFINED TO A VERY NARROW WINDOW OF OPPORTUNITY IN OUR FAR SE
COUNTIES. PROPAGATION OF SURFACE BOUNDARY...ALONG WITH CURRENTLY
RAIN-COOLED AIRMASS IN OUR SE...CERTAINLY SUGGESTS THE GREATER
THREAT WILL BE EAST OF OUR CWA.
TEMP TRENDS STILL LOOKING REASONABLE...ALTHOUGH DID HAVE TO UP
MAX TEMPS OVER MID MO AS BREAK IN THE CLOUDS HERE HAS ALLOWED
TEMPS TO JUMP INTO THE LOWER 70S. THIS WARMUP SHOULD BE FAIRLY
BRIEF...AS CLOUDS AND CAA WILL DROP TEMPS BACK INTO THE 60S FOR
MUCH OF THE AFTERNOON.
TRUETT
&&
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 606 AM CDT THU MAY 31 2012
LARGE AREA OF SHRA/TSRA OVER S CNTRL MO WILL CONTINUE TO MOVE EWD OVER
THE NEXT FEW HOURS. THE NORTHERN EDGE OF THIS MASS WILL PASS CLOSE
ENOUGH TO THE ST. LOUIS METRO AREA TAF SITES THROUGH 14Z TO
WARRANT EITHER VCSH OR A SHORT TEMPO GROUP FOR VFR -SHRA. RADAR IS
SHOWING A GRADUAL INCREASE IN AREAL COVERAGE OR SHRA/SCT TSRA FROM
NERN MO SWWD INTO W CNTRL MO THE PAST COUPLE OF HOURS IN RESPONSE
TO DEEPENING TROUGH OVER THE CENTRAL PLAINS. EXPECT THIS AREA TO
CONTINUE TO INCREASE IN SIZE AND MOVE EWD THROUGH THE MORNING.
HAVE INCLUDED ABOUT 4 HOURS OF -SHRA AT ALL OF THE TAF SITES THIS
MORNING/EARLY AFTERNOON TO ACCOUNT FOR A FAIRLY WIDESPREAD
COVERAGE OF RAIN DURING THIS PERIOD. INITIAL VFR CONDITIONS WILL
DECREASE TO MVFR WITH THE RAIN...WITH CIGS BECOMING MVFR/IFR AS
AREA OF LOW CIGS CURRENTLY OVER WRN IA/ERN NE/NERN KS MOVES SEWD
INTO THE AREA. THESE LOW CLOUDS WILL REMAIN OVER THE AREA UNTIL
TONIGHT WHEN THEY WILL BEGIN TO CLEAR OUT FROM WEST TO EAST.
SURFACE LOW OVER SW MO WILL MOVE ACROSS SRN MO CAUSING CURRENT
ELY WINDS TO BACK NWLY THIS MORNING AT ALL OF THE TAF SITES.
SPECIFICS FOR KSTL...MAY SEE SOME VFR -SHRA AT THE TERMINAL THROUGH
13Z ALONG NRN EDGE OF LARGE MASS OF -SHRA/-TSRA MOVES THROUGH SRN
MO. WILL LIKELY SEE -SHRA BETWEEN 16-20Z AS AREA OF RAIN FILLS IN
OVER THE NEXT FEW HOURS OVER WRN AND CNTRL MO THE NEXT FEW HOURS
AND MOVES EWD. CIGS WILL DECREASE FROM VFR TO MVFR AS THE RAIN
MOVES THROUGH...AND THEN REMAIN MVFR/POSSIBLY IFR AT TIMES LATE
THIS AFTERNOON AND EVENING AFTER THE RAIN EXITS THE REGION. VFR
CONDITIONS SHOULD RETURN AFT 06Z AS CLOUDS MOVE OUT OF THE AREA.
SFC WINDS WILL BACK FROM ELY TO NWLY QUICKLY BETWEEN 17-20Z AS
SFC LOW PASSES TO THE SOUTH.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 PM EDT THU MAY 31 2012
.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE AREA WILL GIVE WAY TO A DEVELOPING WARM
FRONT... WHICH WILL HEAD NORTHWARD THROUGH VIRGINIA TONIGHT. A
POWERFUL STORM SYSTEM WILL APPROACH FROM THE WEST FRIDAY... WITH
COLD FRONT PASSAGE LATE FRIDAY EVENING. HIGH PRESSURE WILL BUILD
OVER THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM THURSDAY...
THROUGH THIS EVENING: THE MAIN CONCERN FOR THE NEXT SEVERAL HOURS IS
THE LOCATION AND AREAL EXTENT OF ANY STORMS. LATEST SURFACE ANALYSIS
SHOWS A HIGHLY DIFFUSE AND WEAK E-W BOUNDARY ACROSS NRN NC. IT IS
ALONG THIS BOUNDARY THAT SEVERAL MODELS... INCLUDING THE 12KM NAM /
4KM NAM CONUS NEST AND RAP... DEVELOP SCATTERED CONVECTION LATE THIS
AFTERNOON. WHILE THIS LOCATION APPEARS REASONABLE GIVEN THE
ANTECEDENT CONDITIONS... THE LOW MOISTURE HERE (BOTH NEAR THE
SURFACE AND WITH BELOW-NORMAL PRECIPITABLE WATER) AND LIKELIHOOD OF
LITTLE MORE THAN MARGINAL INSTABILITY (ESPECIALLY IN THE MID LEVELS
WHERE AIR REMAINS DRY/WARM WITH WEAK LAPSE RATES) WOULD LIMIT
COVERAGE. ANOTHER SUBTLE BOUNDARY SEPARATING DEW POINTS OF 60-65 TO
ITS SOUTH AND 55-60 TO ITS NORTH STRETCHES ACROSS THE SANDHILLS INTO
THE CENTRAL COASTAL PLAIN. THE LAST SEVERAL HRRR MODEL RUNS HAVE
CONSISTENTLY DEVELOPED A FEW STORMS HERE LATER TODAY... ALSO
REASONABLE CONSIDERING THE CONVECTIVE CLOUDS ALREADY FORMING IN THIS
AREA AND CURRENT MLCAPE OF 500-1000 J/KG. WILL HOLD ONTO A MENTION
OF ISOLATED STORMS IN THE SOUTHEAST SECTIONS AS WELL AS OVER THE
NORTH FOR A FEW HOURS LATE THIS AFTERNOON INTO EARLY THIS EVENING...
BEFORE THE LOSS OF HEATING LEADS TO DISSIPATION WITHIN THE WEAK
SHEAR ENVIRONMENT. SURFACE WINDS ARE EXPECTED TO REMAIN FAIRLY LIGHT
FROM THE SOUTH AND SSW AT 6-10 MPH OVERNIGHT... LEADING TO A
DECOUPLING OF THE LOWER TROPOSPHERE AS 925-850 MB WINDS BEGIN TO
STRENGTHEN OUT OF THE SOUTHWEST TO 25-30 MPH... AND THIS STRONG WARM
AIR ADVECTION JUST OFF THE SURFACE LATE TONIGHT MAY ALLOW US TO
RETAIN ENOUGH ELEVATED INSTABILITY FOR ISOLATED SHOWERS OVERNIGHT...
A SCENARIO PAINTED BY THE HIGH-RES WRF-NMM... ALTHOUGH THIS IS
PREDICATED UPON US SEEING A SUFFICIENT RETURN OF DEEPER MOISTURE AND
HIGHER PW VALUES OVERNIGHT. WITH PW EXPECTED TO BE JUST SLIGHTLY
ABOVE NORMAL AT MOST PRIOR TO DAWN FRIDAY... WILL MENTION JUST
ISOLATED SPRINKLES OVERNIGHT. LOWS IN THE MID TO UPPER 60S LOOK
GOOD. -GIH
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 315 PM THURSDAY...
...SEVERE STORMS POSSIBLE FRIDAY AFTERNOON AND EVENING...
FOR FRIDAY/FRIDAY NIGHT: THE OVERALL SYNOPTIC ENVIRONMENT AS WELL AS
SEVERAL KEY THERMODYNAMIC AND SHEAR PARAMETERS CONTINUE TO SUPPORT A
GOOD CHANCE OF STRONG TO SEVERE STORMS LATE FRIDAY AFTERNOON THROUGH
MUCH OF THE EVENING. THE DIFFUSE BOUNDARY ACROSS NRN NC THIS
AFTERNOON IS EXPECTED TO HAVE MOVED NORTH OF THE STATE FRIDAY...
PLACING CENTRAL NC FULLY IN THE PREFRONTAL WARM SECTOR. DEEP LAYER
SHEAR IS PREDICTED BY THE MODELS TO STRENGTHEN TO AROUND 30-35 KTS
AS THE DEEPENING MID LEVEL TROUGH... ASSOCIATED WITH THE LOW WHICH
MOVES FROM NEAR CHI NE ACROSS MI... DIGS INTO THE MID SOUTH AND
SWINGS THROUGH THE SRN/CENTRAL APPALACHIANS WITH A NEGATIVE TILT AND
DECENT DPVA OVER WRN/NRN NC. WHILE THE GREATEST MID LEVEL HEIGHT
FALLS WILL OCCUR TO OUR NW... WE WILL STILL SEE 20-50 METER DROPS
THROUGH FRIDAY. DYNAMIC FORCING WILL ALSO BE AUGMENTED BY
STRENGTHENING UPPER DIVERGENCE... INDUCED BY BOTH THE UPPER JET CORE
OVER OH/LAKE HURON AS WELL AS THE STRENGTHENING SUBTROPICAL JET OVER
THE SOUTHEAST STATES. THE AGEOSTROPHIC RESPONSE FROM THIS LATTER JET
AS IT ACCELERATES BY ABOUT 30-35 KTS IN 12 HOURS SHOULD CAUSE THE
UPPER DIVERGENCE TO INCREASE RAPIDLY OVER CENTRAL NC INTO VA BY
AFTERNOON... ADDING TO THE OVERALL ASCENT AND SUPPORT FOR ORGANIZED
STORMS. 850 MB WINDS DO SPEED UP TO 35-45 KTS OVER CENTRAL NC BY
AFTERNOON... ALTHOUGH THE STRONGEST WINDS WILL BE FOUND TO OUR NORTH
THROUGH VA/PA/NY. AS LOW LEVEL TEMPS AND DEW POINTS INCREASE WITH
STEADY OR COOLING MID LEVELS... INSTABILITY IS EXPECTED TO BECOME
MODERATE BY AFTERNOON WITH MODELS INDICATING MLCAPE OF 1000-1800
J/KG... AROUND 500-800 J/KG OF THIS LOCATED IN THE -10C TO -30C
LAYER... SUGGESTIVE OF A LARGE HAIL THREAT WITH ANY STORMS. WHILE
THE 0-1 KM SRH WILL LIKELY BE MAXIMIZED IN THE VICINITY OF THE
NORTHWARD-RETREATING WARM FRONT... 0-1 KM WIND VECTORS AND DERIVED
PARAMETERS SUCH AS THE BULK RICHARDSON NUMBER CONTINUE TO SUPPORT
THE POTENTIAL FOR SUPERCELLS IN CENTRAL NC. AT THE VERY LEAST WE ARE
LIKELY TO SEE AN ORGANIZED SQUALL LINE WITH A RISK OF LARGE HAIL AS
WELL AS DAMAGING WINDS WITHIN BOWING SEGMENTS. THE LATEST MODEL RUNS
CONTINUE TO PLACE THE GREATEST SEVERE RISK OVER THE CENTRAL AND
EASTERN CWA -- ALTHOUGH SEVERE STORMS COULD OCCUR ANYWHERE -- AND
MAINLY BETWEEN THE HOURS OF 4 PM AND 10 PM. HIGHS 84-90 WITH SW
WINDS 10-15 MPH GUSTING TO 22-27 MPH AFTER THE NOCTURNAL JET MIXES
OUT. GRADUAL CLEARING OVERNIGHT AS THE COLD FRONT MOVES EAST OF THE
AREA AND AS THE MID LEVEL VORTICITY LOBE SWINGS BY TO OUR NORTH.
LOWS 58-65. -GIH
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
BASED ON A MODEL CONSENSUS...FRIDAY EVENINGS CONVECTION WILL BE NEAR
THE COAST AT 12Z SATURDAY MORNING AS THE COLD FRONT PUSHES THROUGH
THE COASTAL PLAIN. A TRAILING UPPER JET WILL SURGE SOUTH UNDERNEATH
AN UPPER LOW OVER THE GREAT LAKES AND ACROSS THE TN VALLEY SATURDAY
AND SATURDAY NIGHT. SOME MID AND HIGH CLOUDS SHOULD ACCOMPANY THE
FAST FLOW ALOFT..SO WHILE SKIES SHOULD BE MOSTLY CLEAR IMMEDIATELY
BEHIND THE FRONT SATURDAY...WE WILL SHOW AN INCREASE IN CLOUD COVER
LATE SATURDAY. DESPITE THE UPPER JET AND A SHOT OF MODEST
DPVA...FORECAST SOUNDINGS APPEAR TO BE TOO TABLE AND DRY
FOR MEASURABLE PRECIP...AND THE NAM IS THE ONLY MODEL CURRENTLY
SHOWING ANY LIGHT PRECIP AT ALL. 850MB TEMPS ARE FORECAST TO FALL
TO AROUND 9-10C...AND DRY ADIABATIC MIXING AND LOW LEVEL THICKNESSES
SCHEMES ALL SUGGEST HIGHS UNDER GUIDANCE IN THE UPPER 70S. LOWS
SATURDAY NIGHT IN THE MID 50S. MORE OF THE SAME IS EXPECTED ON
SUNDAY WITH RELATIVELY DRY NORTHWESTERLY FLOW ALOFT....THOUGH WEAK
HEIGHT RISES AND DOWNSLOPE FLOW SHOULD SPRING HIGHS UP INTO THE LOW
TO MID 80S.
AMPLIFIED FLOW WITH AN OMEGA BLOCK IS THEN EXPECTED OVER THE CONUS
NEXT WEEK...LEADING TO EAST AND WEST COAST TROUGHS AND A RIDGE OVER
THE CENTRAL US. NORTHWESTERLY FLOW IS FORECAST TO CONTINUE MONDAY
BEFORE MODELS SHOW VORTICITY SWINGING AROUND THE EAST COAST
TROUGH...SOUTH ACROSS THE MID ATLANTIC STATES TO THE CAROLINAS.
WHILE THERE IS GENERALLY GOOD LARGE SCALE AGREEMENT...THE ECMWF AND
GFS VARY ON THE AMPLITUDE/TIMING OF FORCING AND THE LOCATION OF THE
MEAN FRONTAL ZONE...WHICH SHOULD STRETCH FROM THE SOUTHEAST US TO
THE UPPER MIDWEST. THIS LEADS TO A LOW CONFIDENCE FORECAST
REGARDING THE TIMING AND DURATION OF PRECIP CHANCES FROM LATE MONDAY
THROUGH THE END OF THE PERIOD. HIGHS ARE EXPECTED TO BE AROUND
NORMAL MONDAY IN THE MID 80S...FALLING TO SLIGHTLY BELOW NORMAL WITH
INCREASING PRECIP CHANCES THROUGH MID WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 120 PM THURSDAY...
VFR CONDITIONS WILL HOLD OVER CENTRAL NC THROUGH TONIGHT... WITH
WEAK HIGH PRESSURE AND A DRY AIR MASS OVER THE REGION. VERY ISOLATED
AND CIRCUMNAVIGABLE STORMS MAY DEVELOP PRIMARILY NEAR FAY BUT ALSO
POSSIBLE NEAR RDU/RWI BETWEEN 20Z THIS AFTERNOON AND 01Z THIS
EVENING... AND THE TYPICAL VARIABLE/GUSTY WINDS NEAR STORMS AND MVFR
CONDITIONS BENEATH STORMS ARE A SLIM POSSIBILITY... HOWEVER THE VAST
MAJORITY OF THE DAY EVEN AT THIS SPOTS WILL REMAIN VFR. VSBYS/CIGS
WILL STAY VFR TONIGHT... HOWEVER THERE IS A CHANCE OF BORDERLINE LOW
LEVEL WIND SHEAR CONDITIONS (MAINLY SPEED SHEAR) FROM 07Z-13Z FRIDAY
MORNING AT ALL CENTRAL NC LOCATIONS... AS NEAR-SURFACE WINDS FROM
THE S AND SSW AT 5-9 KTS ARE TOPPED BY SWRLY WINDS OF 25-30 KTS AT
1800-2500 FT AGL. THIS LOW LEVEL JET WILL MIX OUT WITH HEATING SOON
AFTER DAYBREAK FRIDAY. AN APPROACHING COLD FRONT WILL BRING
WIDESPREAD STRONG THUNDERSTORMS FRIDAY AFTERNOON... BUT MAINLY AFTER
THE END OF THIS TERMINAL AERODROME FORECAST VALID PERIOD.
LOOKING BEYOND 18Z FRIDAY... CONFIDENCE IS HIGH THAT CENTRAL NC
AIRPORTS WILL BE AFFECTED BY STRONG STORMS AHEAD OF A COLD FRONT
LATE FRIDAY AFTERNOON INTO THE EVENING... ESPECIALLY FROM 20Z
THROUGH 03Z. LARGE HAIL OVER 1 INCH IN DIAMETER AND SURFACE WIND
GUSTS TO OVER 60 KTS ARE POSSIBLE. AVIATION INTERESTS SHOULD PAY
CLOSE ATTENTION TO THE LATEST CONDITIONS AND FORECASTS FRIDAY
AFTERNOON/EVENING. MVFR CIGS MAY BRIEFLY LINGER BEHIND THE COLD
FRONT LATE FRIDAY NIGHT. VFR CIGS ARE EXPECTED LATE SATURDAY THROUGH
SUNDAY DUE TO UPPER LEVEL DISTURBANCES PASSING OVERHEAD. CONDITIONS
WILL REMAIN VFR THROUGH MONDAY... THEN ADDITIONAL DISTURBANCES AND A
BACKDOOR COOL FRONT MAY BRING MVFR CONDITIONS MONDAY NIGHT/TUESDAY.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1218 PM CDT THU MAY 31 2012
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION...
UPDATE... /ISSUED 1015 AM CDT THU MAY 31 2012/
CURRENT FORECAST IS ON TRACK AT THIS TIME. NO UPDATES TO GRIDS AS
OF THIS MOMENT. SEE BELOW FOR UPDATED DISCUSSION ON SEVERE WEATHER
POTENTIAL.
RRH
AS OF 10 AM...CONDITIONS ACROSS THE MIDSOUTH RANGED FROM MOSTLY
CLEAR ACROSS THE TENNESSEE RIVER VALLEY TO MOSTLY CLOUDY ACROSS
THE MAJORITY OF NORTHERN MISSISSIPPI AND EASTERN ARKANSAS. THE SUN
HAS BEEN OUT FOR MOST OF THE MORNING ACROSS WESTERN TENNESSEE AND
NORTHEASTERN MISSISSIPPI. SOME ADDITIONAL CLEARING IS VISIBLE ON
SATELLITE OVER WESTERN MISSISSIPPI...SOUTHERN ARKANSAS...AND
NORTHERN LOUISIANA. A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
OVER NORTHEASTERN ARKANSAS BUT THESE STORMS HAVE POSED NO THREAT
OF SEVERE WEATHER SO FAR.
THE INSTABILITY WILL GRADUALLY INCREASE THROUGH THE REST OF THE
MORNING AND EARLY AFTERNOON HOURS IN AREAS WHERE CLOUD COVER HAS
CLEARED. MODELS ARE INDICATING CAPE VALUES BETWEEN 2000 J/KG TO
3000 J/KG WILL BE POSSIBLE BY EARLY THIS AFTERNOON. LATEST RUN OF
THE NAM MODEL HAS INITIALIZED WELL AND IS HANDLING THE CURRENT
CONVECTION OVER MISSOURI AND TEXAS WITH GOOD ACCURACY. GOING BY
THIS MODEL...CONVECTION WILL RAPIDLY INCREASE ACROSS ARKANSAS
BETWEEN THE HOURS OF NOON AND 2 PM. THIS AREA OF THUNDERSTORMS
WILL MOVE ACROSS THE MIDSOUTH THIS AFTERNOON AND CLEAR THE REGION
BY THIS EVENING. A FEW SHOWERS MAY DEVELOP ALONG THE COLD FRONT
THIS EVENING BUT THE SEVERE WEATHER SHOULD HAVE CLEARED OUT BY
THEN. THE MAIN THREATS FOR THIS AFTERNOONS STORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. TORNADOES DO NOT SEEM LIKELY ACROSS THE
MAJORITY OF THE MIDSOUTH AT THIS TIME DUE TO A UNIDIRECTIONAL WIND
FIELD. HOWEVER...AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM...AN
ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT FOR NORTHWEST
TENNESSEE AND THE MISSOURI BOOTHEEL. THIS IS BECAUSE THE SURFACE
WINDS WILL REMAIN BACKED TO THE SOUTHEAST A LITTLE LONGER ACROSS
THIS AREA OF CONCERN THAN THE REST OF THE MIDSOUTH. SOUNDINGS FOR
TODAY SHOW DRIER AIR IN THE LOWER ATMOSPHERE WITH DOWNDRAFT CAPE
VALUES AS HIGH AS 1000 J/KG TO 1500 J/KG...WHICH WOULD INDICATE A
BETTER POTENTIAL FOR DAMAGING WINDS. STEEP LOW LEVEL LAPSE RATES
WILL ALLOW FOR STRONG UPDRAFTS...WHICH WILL SOMEWHAT INCREASE THE
HAIL POTENTIAL.
RRH
PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
18Z TAF CYCLE (31/18Z-01/18Z)
NUMEROUS THUNDERSTORMS ARE EXPECTED TO SPREAD INTO AND DEVELOP
ACROSS THE MIDSOUTH THIS AFTERNOON AS AN UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT APPROACH FROM THE WEST. A FEW STORMS MAY BE
SEVERE WITH DAMAGING WINDS AND LARGE HAIL. THUNDERSTORMS GRADUALLY
ENDING FROM THE WEST THIS EVENING AND OVERNIGHT. SOUTHWEST WINDS
10-12 KTS WITH OCCASIONAL GUSTS TO NEAR 18 KTS WILL PREVAIL THIS
AFTERNOON. WIND TURNING TO THE NORTHWEST AND NORTH TONIGHT AT 12
KTS WITH GUSTS TO 18 KTS. MVFR CEILINGS SPREADING INTO THE AREA
TONIGHT BEHIND THE COLD FRONT GRADUALLY CLEARING AT KMEM AND KJBR
AFTER 01/13-15Z.
JCL
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 57 74 58 83 / 50 10 0 20
MKL 55 73 48 81 / 60 10 0 10
JBR 55 74 54 82 / 30 10 10 20
TUP 62 76 53 83 / 80 10 0 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
309 PM CDT THU MAY 31 2012
.SHORT TERM (TONIGHT THROUGH FRIDAY)...OUTFLOW BOUNDARY HAS
REACHED VICTORIA. HOWEVER...SO FAR IT LOOKS LIKE THE CAP AND
NEGATIVE H85 THEATA-E ADVECTION IS WINNING OUT WITH LACK OF
CONVECTION ALONG THE OUTFLOW BOUNDARY ACROSS OUR NE CWA AND
EWX CWA. STILL THE POTENTIAL THROUGH THE LATE AFTERNOON AND
EVENING ACROSS MAINLY THE NORTHWEST CWA FOR CONVECTION TO
DEVELOP WHERE CAP ERODES AND BETTER LOW LEVEL CONVERGENCE IS
SITUATED. IN ADDITION...4 KM NMM AND HRRR HINTING AT CONVECTION
DEVELOPING ACROSS MEXICO POSSIBLY MAKING IT INTO WESTERN CWA LATER
THIS EVENING. WILL KEEP LOW CHANCE POPS IN THE FORECAST THIS
EVENING ALONG AND WEST OF A GEORGE WEST TO HEBBRONVILLE
LINE...WITH 10-20 POPS EAST OF THIS LINE. STILL SUFFICIENT
INSTABILITY AND SHEAR THAT SHOULD STORMS DEVELOP ACROSS THE BRUSH
COUNTRY OR RIO GRANDE PLAINS THEY COULD BECOME STRONG TO SEVERE.
EVENTUALLY THE WEAK BOUNDARY/FRONT WILL STALL OVER THE AREA
OVERNIGHT AND WASH OUT FRIDAY AFTERNOON. WILL MAINTAIN INHERITED
10-20 POPS IN THE FORECAST DURING THE DAY FRIDAY...ALTHOUGH
FORCING APPEARS PRETTY WEAK.
&&
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...DRYING IN THE LOWER
LEVELS WILL LEAD TO A DRY WEEKEND. MODELS ARE IN AGREEMENT WITH AN
UPPER LEVEL CLOSED LOW DEVELOPING ALONG THE WESTERN COAST OF MEXICO.
MODELS PROG THE LOW TO TREK NORTHEAST OVER THE SIERRA MADRE TO THE
RIO GRANDE SOUTH OF THE BIG BEND AREA THROUGH EARLY NEXT WEEK. THIS
WILL BRING MOISTURE TO THE MID AND UPPER LEVELS OF THE ATMOSPHERE...
WITH INCREASING HIGH CLOUDS. SURFACE HIGH OVER THE NORTHERN GULF AND
DEVELOPING LOW OVER THE SOUTHERN PLAINS WILL ALLOW FOR A MODERATE
SOUTHEASTERLY FLOW TO DEVELOP EACH AFTERNOON THROUGH THE
WEEK...BRINGING MOISTURE BACK TO THE LOW LEVELS. HOWEVER...CAPPING
REMAINS QUITE STRONG...WITH BEST MOISTURE IN THE LOW LEVELS...
LEADING TO POSSIBLY ISOLATED SHOWERS IN THE MORNING...WITH ISOLATED
THUNDERSTORM ACTIVITY POSSIBLE IN THE AFTERNOON ALONG THE DEVELOPING
SEABREEZE EACH AFTERNOON THROUGH THE END OF THE EXTENDED. A BIT MORE
COVERAGE WILL BE POSSIBLE AS THE UPPER LOW SHIFTS TO THE
NORTHEAST...THO WILL ALL BE DEPENDENT ON IF THE CAP CAN WEAKEN WELL
ENOUGH. WITH NO STRONG UPPER LEVEL DIFFLUENCE ALOFT...NO STRONG
STORMS ARE EXPECTED AT THIS TIME. OVERALL...TEMPERATURES WILL REMAIN
WARM WITH SIMILARITIES AS THE PAST COUPLE OF DAYS. DUE TO WARM H85
TEMPS MIXING DOWN EACH AFTERNOON...KEPT ABOVE GUIDANCE THROUGH THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 90 73 91 76 / 10 10 10 10 10
VICTORIA 72 93 71 93 73 / 20 20 10 10 10
LAREDO 76 97 76 100 76 / 40 20 10 10 10
ALICE 74 95 72 97 74 / 20 20 10 10 10
ROCKPORT 78 89 77 88 78 / 10 10 10 10 10
COTULLA 73 95 70 99 73 / 40 20 10 10 10
KINGSVILLE 75 93 73 93 75 / 10 20 10 10 10
NAVY CORPUS 78 89 77 89 78 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 PM CDT THU MAY 31 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
304 PM CDT THU MAY 31 2012
FORECAST CHALLENGES INCLUDE LINGERING SHOWERS INTO THIS
EVENING...THEN CLEARING AND FOG POTENTIAL OVERNIGHT/EARLY FRIDAY
MORNING. ANOTHER CHALLENGE WILL BE THE POTENTIAL FOR REDEVELOPMENT
OF ISOLATED SHOWERS FRIDAY.
CURRENT WATER VAPOR IMAGERY COMBINED WITH 500 MB RAP ANALYSIS SHOW
DEEP MID-LEVEL TROUGH ROTATING SOUTHEAST TROUGH WI/SOUTHERN WI. COLD
AIR ALOFT/LINGERING MID-LEVEL FRONTOGENESIS ASSOCIATED WITH THE
TROUGH WAS PRODUCING SCATTERED SHOWER ACTIVITY ACROSS PORTIONS OF
THE FORECAST AREA. OTHERWISE...CLOUD COVER WAS PRETTY EXTENSIVE
ACROSS THE AREA AND THIS WAS HOLDING TEMPERATURES DOWN IN THE MID/UPPER
50S WHICH IS SOME 20 DEGREES BELOW NORMAL.
31.12Z NCEP MODEL SUITE ALONG WITH THE 31.09Z SREF SHOWING GOOD
AGREEMENT WITH OVERALL SYNOPTIC SETUP THROUGH THE SHORT TERM.
FOR TONIGHT...WILL SEE THAT MID-LEVEL TROUGH MORPH INTO A CLOSED LOW
AND MOVE EAST TOWARD LAKE MICHIGAN THROUGH THE OVERNIGHT HOURS.
APPEARS A FEW DEFORMATION AREA -SHRA WILL LINGER ACROSS THE SOUTH
INTO THE EARLY EVENING HOURS...BUT THEN SHOULD DISSIPATE AROUND 8-9
PM. THE REST OF TONIGHT WILL SEE SLOWLY CLEARING SKIES FROM
NORTHWEST TO SOUTHEAST. CLEARING SKIES/LIGHT WINDS/FAIRLY MOIST
LOWER BOUNDARY LAYER WILL LEAD TO THE POTENTIAL FOR SOME FOG.
MITIGATING FACTOR TO WIDESPREAD FOG WILL BE LIGHT NORTHERLY
COMPONENT TO THE WIND WITH SPEEDS AROUND 10KT AT 500-1000AGL. KEPT
AREAS OF FOG LIMITED TO MISSISSIPPI/WISCONSIN RIVER VALLEYS WHERE
BETTER DECOUPLING OF THE WINDS WILL TAKE PLACE. OTHERWISE...LOOK FOR
OVERNIGHT LOWS ACROSS THE AREA IN THE UPPER 30S IN FAVORED
LOWER-LYING COLD AREAS...TO THE LOWER/MID 40S ELSEWHERE.
ON FRIDAY...THE CLOSED LOW WILL CONTINUE TO DEEPEN AND MOVE SLOWLY
EAST INTO LOWER MICHIGAN. CYCLONIC FLOW/COLD POOL ALOFT WILL RESIDE
OVER OUR AREA WITH STEEP 0-3KM TEMPERATURE LAPSE RATES IN THE
8.5-9C/KM RANGE. NAM ALSO SHOWING 0-3KM MUCAPE AROUND 300J/KG. THIS
SHOULD BE SUFFICIENT FOR EXTENSIVE CUMULUS/TOWERING CUMULUS FIELD
OVER THE FORECAST AREA ALONG WITH ISOLATED SHOWER ACTIVITY. LOOK FOR
HIGHS FRIDAY UNDER THE COLD POOL ALOFT TO TOP OFF IN THE 65-70
DEGREE RANGE. A FEW LINGERING -SHRA STILL POSSIBLE ALONG/NORTHEAST
OF I-94 EARLY FRIDAY EVENING. SCATTERED SHOWERS ALSO POSSIBLE
MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER FRIDAY NIGHT AS A
WEAK MID-LEVEL TROUGH DROPS SOUTHEAST FROM THE DAKOTAS INTO IA.
FOR SATURDAY...THE CLOSED LOW MOVES INTO EASTERN UPPER MI WITH COLD
CYCLONIC FLOW ALOFT LINGERING ACROSS OUR AREA. THE NAM SHOWS 0-3KM
MUCAPE INCREASING INTO THE 1000-1400J/KG RANGE WHILE 0-1KM ML CAPE
AROUND 500J/KG. THIS WILL LEAD TO ANOTHER DAY OF EXTENSIVE
CUMULUS/TOWERING CUMULUS FIELD ALONG WITH SCATTERED SHRA AND A FEW
THUNDERSTORMS. OTHERWISE...HIGHS SATURDAY ANTICIPATED TO TOP OFF
AGAIN IN THE 65-70 DEGREE RANGE. LOOK FOR THE CONVECTION/CLOUDS TO
DISSIPATED BY EARLY EVENING AS THE LOW/COLD POOL ALOFT MOVES FARTHER
EAST TOWARD LAKE HURON AND RIDGING BUILDS IN FROM THE NORTHERN
PLAINS.
WILL GO DRY ON SUNDAY AS MODELS ARE A BIT SLOWER WITH A MID-LEVEL
TROUGH TOPPING THE RIDGE OVER THE DAKOTAS/CENTRAL PLAINS. WILL
HOWEVER LIKELY SEE AN INCREASE IN MID-HIGH LEVEL CLOUDINESS IN
ADVANCE OF THIS FEATURE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
304 PM CDT THU MAY 31 2012
31.12Z GFS/ECMWF SHOW A RATHER BLOCKY PATTERN SETTING UP THROUGH THE
PERIOD WITH TROUGHS RESIDING OVER WEST/EAST COASTS AND RIDGE OF HIGH
PRESSURE GETTING PINCHED OVER THE CENTRAL CONUS. SHRA/TS CHANCES
WILL BE SEEN SUNDAY NIGHT THROUGH MONDAY AS A WEAKENING MID-LEVEL
TROUGH TOPS THE RIDGE OVER THE DAKOTAS AND HEADS TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY. FORCING NOT VERY IMPRESSIVE WITH THIS
FEATURE SO WILL CONTINUE WITH SMALLER-END CHANCES FOR NOW. NARROW
RIDGE OF HIGH PRESSURE LOOKS TO KEEP THE AREA DRY THROUGH THE
REMAINDER OF THE PERIOD. TEMPERATURES EXPECTED TO BE MORE SEASONABLE
MONDAY THROUGH THURSDAY AS WELL WITH HIGHS IN THE MID 70S TO AROUND
80.
&&
.AVIATION...THROUGH 18Z FRIDAY
1155 AM CDT THU MAY 31 2012
CIGS ASSOCIATED WITH AN AREA OF LOW PRESSURE WILL EXIT THE AREA THIS
EVENING AS AN AREA OF HIGH PRESSURE BUILDS IN FROM THE PLAINS.
SCT/ISOLD -SHRA STILL POSSIBLE AT KRST/KLSE THROUGH 21Z OR SO. WILL
LEAVE OUT OF TAFS FOR NOW AS CONFIDENCE IS HIGHER FOR PCPN CHANCES
TO THE SOUTH. WILL AMEND IF NECESSARY.
THE HIGH WILL BRING LIGHTER NEAR SFC WINDS...CLEARING SKIES...AND
DRIER AIR. HOWEVER...RECENT RAINS WILL LEAVE A MOISTURE SOURCE AT
THE SFC...AND SEE A THREAT FOR VALLEY FOG EARLY FRI MORNING. NAM12
BUFKIT SOUNDINGS SUGGESTS T/TD SPREAD DECREASES RAPIDLY AT KLSE THIS
EVENING...BUT THE RAP KEEPS A FEW DEGREE SPREAD THROUGH THE NIGHT AS
DOES THE GFS. COULD BE ADVECTING IN DRIER SFC AIR FROM THE
NORTH...WHICH WOULD KEEP FOG FROM DEVELOPING. CONFIDENCE SHAKY ON
HOW MUCH OR IF FOG WILL FORM. WILL GO WITH BCFG FOR NOW. TRENDS WILL
BE MONITORED THROUGH THE EVENING.
GOOD LOW LEVEL LAPSE RATES OF AROUND 9 C/KM IN THE 1000:850 MB LAYER
AND SOME RESIDUAL LOW LEVEL MOISTURE SHOULD LEAD TO SOME LATE
MORNING/AFTERNOON CU. NOT SURE THERE IS ENOUGH MOISTURE/INSTABILITY
TO PRODUCE -SHRA. SOMETHING TO WATCH FOR TOMORROW...BUT WILL LEAVE
OUT OF THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 PM CDT THU MAY 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1155 AM CDT THU MAY 31 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
322 AM CDT THU MAY 31 2012
MAIN FORECAST CONCERNS ARE ON RAIN SHOWERS TODAY MAINLY ALONG AND
SOUTH OF INTERSTATE 90. FOCUS THEN TURNS TO FOG POTENTIAL TONIGHT
ALONG THE MISSISSIPPI AND WISCONSIN RIVER VALLEYS.
AS OF 3 AM THIS MORNING...WATER VAPOR IMAGERY SHOWED AN UPPER LEVEL
TROUGH MOVING INTO UPPER AND MIDDLE MISSISSIPPI RIVER VALLEY. RAIN
WAS FALLING THIS MORNING ACROSS MUCH OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA INTO PORTIONS OF SOUTHWEST AND CENTRAL
WISCONSIN.
THE TROUGH WILL GRADUALLY DRIFT EAST ACROSS THE FORECAST AREA TODAY
AND IS EXPECTED TO CLOSE INTO AN UPPER LOW ALONG THE
WISCONSIN/ILLINOIS BORDER LATE THIS AFTERNOON. PLAN ON CLOUDY SKIES
ACROSS THE AREA TODAY WITH RAIN ALONG AND SOUTH OF INTERSTATE 90
THIS MORNING. THE RAIN BAND IS SUPPORTED BY A BAND OF FRONTOGENESIS
IN THE THE 700-500 MB LAYER. THIS BAND WEAKENS THROUGH 15Z THIS
MORNING...SO SHOULD SEE STRATIFORM RAIN SWITCH OVER TO RAIN SHOWERS
LATE THIS MORNING INTO THIS AFTERNOON. THE MAIN FORCING FOR THE
RAIN SHOWERS THIS AFTERNOON WILL BE DRIVEN BY WEAK OMEGA IN THE
900-700 MB LAYER AND COOLER AIR ALOFT PRODUCING STEEP LAPSE RATES.
SHOULD SEE THE SHOWERS BECOME MORE SCATTERED EARLY THIS AFTERNOON
THROUGH THE LATE AFTERNOON HOURS. PLAN ON HIGHS TODAY RANGING FROM
THE LOWER 60S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 50S OVER
NORTHEAST IOWA...RATHER CHILLY FOR THIS TIME OF YEAR. NORMAL HIGHS
FOR THIS TIME OF YEAR ARE IN THE LOWER TO MIDDLE 70S.
THE UPPER LOW WILL SHIFT EAST OF THE FORECAST AREA TONIGHT AS
SURFACE HIGH PRESSURE EDGES INTO THE AREA FROM THE NORTHERN PLAINS.
WINDS WILL BECOME LIGHT TONIGHT AND CLOUDS ARE EXPECTED TO DECREASE
THROUGH THE OVERNIGHT HOURS. THIS LEADS TO FOG CONCERNS TONIGHT WITH
THE PRECIPITATION AND CLOUD COVER ACROSS THE REGION TODAY. THE MAIN
FOG CONCERNS WILL BE ALONG THE RIVER VALLEYS. FORECAST SOUNDINGS ARE
SHOWING LIGHT WINDS FROM THE SURFACE THROUGH AROUND 2 KFT...WITH
TEMPERATURE AND DEWPOINT SPREADS RANGING FROM 0-2 DEGREES. LOOKS
LIKE A DECENT SET UP FOR VALLEY FOG IF SKIES CLEAR. WILL INCLUDE
AREAS OF FOG ALONG MISSISSIPPI AND WISCONSIN RIVER VALLEYS FROM
MIDNIGHT TONIGHT THROUGH 8 AM FRIDAY MORNING. IF THE FOG DEVELOPS
PLAN ON VISIBILITIES REDUCED TO AROUND 1/4 MILE. LOOK FOR LOWS
TONIGHT TO FALL INTO THE LOWER 40S.
SURFACE HIGH PRESSURE WILL BE IN CONTROL ON FRIDAY AND SHOULD
PROVIDE DRY WEATHER ACROSS THE FORECAST AREA AS THE UPPER LOW DRIFTS
EAST OVER LOWER MICHIGAN. FORECAST SOUNDINGS SHOW THE POTENTIAL FOR
SOME HIGH BASED CUMULUS CLOUDS LATE FRIDAY MORNING INTO FRIDAY
AFTERNOON. PLAN ON MOSTLY SUNNY SKIES EARLY IN THE DAY ON
FRIDAY...BECOMING PARTLY SUNNY IN THE AFTERNOON. PLAN ON HIGH
TEMPERATURES RANGING FROM THE MIDDLE TO UPPER 60S. A SHORTWAVE
TROUGH IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE EASTERN DAKOTAS
LATE FRIDAY AFTERNOON AND PUSH EAST APPROACHING THE UPPER
MISSISSIPPI RIVER VALLEY LATE FRIDAY NIGHT INTO SATURDAY. HIGH
CLOUDS WILL START TO SPILL INTO THE REGION AHEAD OF THIS FEATURE
LATE FRIDAY AFTERNOON INTO FRIDAY NIGHT. A FEW SHOWERS COULD MOVING
INTO PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA FRIDAY
NIGHT AS THE SHORTWAVE PUSHES INTO CENTRAL MINNESOTA. WINDS WILL
SWITCH TO THE WEST AS THIS WAVE DRAWS CLOSER...USHERING IN WARMER
AIR. PLAN ON LOWS FRIDAY NIGHT RANGING FROM THE MID 40S ACROSS NORTH
CENTRAL WISCONSIN TO THE UPPER 40S TO LOWER 50S OVER SOUTHEAST
MINNESOTA INTO NORTHEAST IOWA.
THE UPPER LEVEL LOW WILL FINALLY LIFT NORTH ACROSS WESTERN LAKE
HURON BY EARLY SATURDAY MORNING. THE SHORTWAVE PUSHES INTO THE UPPER
MISSISSIPPI RIVER VALLY DURING THE DAY ON SATURDAY BUT BECOMES
RATHER WASHED OUT AS IT MOVES INTO THE TROUGH ON THE BACK EDGE OF
THE UPPER LOW. THE NAM AND GFS TRY TO GENERATE CONVECTION ACROSS THE
FORECAST AREA DURING THE DAY ON SATURDAY WITH SURFACE BASED CAPE
VALUES INCREASING INTO THE 500-900 J/KG RANGE. THE GEM AND ECMWF
ARE DRY BUT HAVE SOME REFLECTION OF A WEAK SURFACE TROUGH IN THE
SURFACE PRESSURE FIELDS. COULD SEE ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOP ON SATURDAY AS THIS TROUGH MOVES THROUGH...BUT
CONFIDENCE LOW THAT THIS WILL OCCUR. WILL HAVE TO KEEP A CLOSE WATCH
ON THIS THE NEXT FEW MODEL RUNS. WILL MAINTAIN SLIGHT CHANCES FOR
PRECIPITATION ON SATURDAY BUT WILL ADD THUNDER MENTION. IF
PRECIPITATION DEVELOPS IT WILL LIKELY BE SURFACE BASED AND WILL TAP
INTO SOME WEAK CAPE LEADING TO A FEW THUNDERSTORMS. IF THE STORMS
DEVELOP THEY WILL BE BATTLING WEAK SHEAR AND SUBSIDENCE IN THE
800-600 MB LAYER...SO WOULD EXPECT ANYTHING ORGANIZED. UPPER LEVEL
RIDGING IS EXPECTED TO PUSH INTO THE FORECAST AREA FROM THE NORTHERN
PLAINS LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS SHOULD
PROVIDE QUIET WEATHER SATURDAY EVENING. CONVECTION LOOKS TO ERUPT
OVER THE DAKOTAS SATURDAY NIGHT INTO SUNDAY AS A SHORTWAVE MOVES
THROUGH THE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE
CENTRAL/NORTHERN PLAINS. WILL HAVE TO KEEP A WATCH ON THIS ACTIVITY
LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING. 850 MB MOISTURE
TRANSPORT LOOKS TO STAY WELL WEST OF THE FORECAST AREA UNTIL EARLY
SUNDAY MORNING...SO SATURDAY NIGHT SHOULD BE DRY. PLAN ON HIGHS ON
SATURDAY CLIMBING INTO THE 70S WITH OVERNIGHT LOWS IN THE 50S.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
322 AM CDT THU MAY 31 2012
31.00 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT ON SUNDAY SHOWING
A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN DAKOTAS AND HEADING
SOUTHEAST INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE SUNDAY
AFTERNOON INTO SUNDAY EVENING. LOOK FOR SHOWERS AND THUNDERSTORMS TO
SPREAD INTO THE AREA SUNDAY AFTERNOON INTO SUNDAY NIGHT AS THE
TROUGH MOVES ACROSS THE AREA. 0-3KM MUCAPE VALUES ARE EXPECTED TO
INCREASE INTO THE 1000-2500 J/KG RANGE...HIGHEST VALUES WEST OF THE
MISSISSIPPI RIVER...BY LATE SUNDAY EVENING. 0-6 KM SHEAR IS EXPECTED
TO BE AROUND 40 KTS...BUT THE STORMS WILL PROBABLY BE ELEVATED.
OVERALL EFFECTIVE SHEAR LOOKS LIMITED BUT WILL HAVE TO KEEP A CLOSE
WATCH ON THIS WITH THE NEXT FEW MODEL RUNS. HIGHS ON SUNDAY WILL
RANGE FROM THE MID 70S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER
70S ACROSS NORTHEAST IOWA. SHOWER AND THUNDERSTORM CHANCES WILL
CONTINUE INTO MONDAY BEFORE AN UPPER RIDGE BUILDS ACROSS THE AREA.
THE GFS AND ECMWF SHOW THE RIDGE HOLDING STRONG ACROSS THE AREA
MONDAY NIGHT INTO WEDNESDAY PROVIDING DRY AND QUIET WEATHER. THE
RIDGE LOOKS TO BREAK DOWN LATE WEDNESDAY INTO THURSDAY. PLAN ON
HIGHS IN THE 70S TO LOWER 80S MONDAY THROUGH TUESDAY. SLIGHTLY
COOLER TEMPERATURES ON POSSIBLE ON WEDNESDAY AS SURFACE HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE NORTHEAST.
&&
.AVIATION...
1155 AM CDT THU MAY 31 2012
CIGS ASSOCIATED WITH AN AREA OF LOW PRESSURE WILL EXIT THE AREA THIS
EVENING AS AN AREA OF HIGH PRESSURE BUILDS IN FROM THE PLAINS.
SCT/ISOLD -SHRA STILL POSSIBLE AT KRST/KLSE THROUGH 21Z OR SO. WILL
LEAVE OUT OF TAFS FOR NOW AS CONFIDENCE IS HIGHER FOR PCPN CHANCES
TO THE SOUTH. WILL AMEND IF NECESSARY.
THE HIGH WILL BRING LIGHTER NEAR SFC WINDS...CLEARING SKIES...AND
DRIER AIR. HOWEVER...RECENT RAINS WILL LEAVE A MOISTURE SOURCE AT
THE SFC...AND SEE A THREAT FOR VALLEY FOG EARLY FRI MORNING. NAM12
BUFKIT SOUNDINGS SUGGESTS T/TD SPREAD DECREASES RAPIDLY AT KLSE THIS
EVENING...BUT THE RAP KEEPS A FEW DEGREE SPREAD THROUGH THE NIGHT AS
DOES THE GFS. COULD BE ADVECTING IN DRIER SFC AIR FROM THE
NORTH...WHICH WOULD KEEP FOG FROM DEVELOPING. CONFIDENCE SHAKY ON
HOW MUCH OR IF FOG WILL FORM. WILL GO WITH BCFG FOR NOW. TRENDS WILL
BE MONITORED THROUGH THE EVENING.
GOOD LOW LEVEL LAPSE RATES OF AROUND 9 C/KM IN THE 1000:850 MB LAYER
AND SOME RESIDUAL LOW LEVEL MOISTURE SHOULD LEAD TO SOME LATE
MORNING/AFTERNOON CU. NOT SURE THERE IS ENOUGH MOISTURE/INSTABILITY
TO PRODUCE -SHRA. SOMETHING TO WATCH FOR TOMORROW...BUT WILL LEAVE
OUT OF THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
322 AM CDT THU MAY 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK