Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/19/12
AREA FORECAST DISCUSSION
NWS PUEBLO CO
317 PM MDT TUE JUL 17 2012
.SHORT TERM...
(TONIGHT AND WEDNESDAY)
CURRENT WATER VAPOR IMAGERY TELLING THE STORY WITH MUCH DRIER AIR
ACROSS WESTERN COLORADO MOVING INTO CENTRAL AND EASTERN COLORADO
ALONG WITH SUBSIDENCE ASSOCIATED WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHERN HIGH PLAINS AND SOUTHERN ROCKIES BUILDING INTO THE CENTRAL
ROCKIES...HAS HELPED TO TAME CONVECTION ACROSS THE AREA THROUGH THE
EARLY AFTERNOON. REGIONAL RADARS STILL INDICATING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN...WITH
THE BEST COVERAGE ACROSS THE SOUTHWEST AND CENTRAL MTS AT THIS TIME.
RADAR DATA ALSO INDICATING A FEW CELLS POPPING ACROSS KIOWA COUNTY AT
THIS TIME. SATELLITE AND VISUAL INSPECTION INDICATING CU ACROSS THE
EASTERN MTS SHOWING MORE VERTICAL DEVELOPMENT AS WELL. AT THE
SFC...WEAK FRONTAL BOUNDARY HAS PUSHED THROUGH ALL OF THE SOUTHEAST
PLAINS WITH LATEST DATA INDICATING LOWER PRESSURES ACROSS THE LEE OF
THE ROCKIES AT THIS TIME.
TONIGHT...WITH A FEW MORE HOURS OF HEATING ALONG WITH WINDS BECOMING
MORE UPSLOPE ACROSS THE EASTERN PLAINS...SHOULD CONTINUE TO SEE
ISOLATED TO SCATTERED STORMS FIRING ACROSS THE HIGHER TERRAIN
THROUGH THE EARLY EVENING...WITH A FEW STORMS FIRING ACROSS THE
IMMEDIATE ADJACENT PLAINS THROUGH THE FAR SE PLAINS. LATEST HIGHER
RESOLUTION HRRR MODEL CONTINUES TO INDICATE SCATTERED STORMS FIRING
ACROSS THE PIKES PEAK REGION THROUGH THE EARLY EVENING WITH THE
DEVELOPING LOW LEVEL UPSLOPE. THIS STILL POSES A THREAT FOR LOCALLY
HEAVY RAINFALL WITH WEAK WESTERLY FLOW ALOFT ACROSS THE EASTERN MTS
AT THIS TIME. NOT AS CONCERNED WITH THE HEAVY RAIN THREAT ACROSS
WESTERN PORTIONS OF THE AREA WITH FLOW ALOFT A TAD FASTER WITH DEW
PTS DOWN INTO THE 30S AT THIS TIME. CLEARING SKIES EXPECTED THROUGH
THE OVERNIGHT AND HAVE FOLLOWED CLOSER TO THE COOLER SIDE OF
GUIDANCE FOR OVERNIGHT LOWS.
WEDNESDAY...UPPER LEVEL RIDGING CONTINUES TO BUILD ACROSS THE
CENTRAL ROCKIES AND INTO THE NORTHERN ROCKIES WITH UPPER FLOW
BECOMING MORE SOUTHERLY ACROSS WESTERN PORTIONS OF THE AREA AND
MORE NORTHERLY ACROSS EASTERN PORTIONS OF THE STATE...THOUGH
REMAINING WEAK. MOISTURE PLUME ACROSS EASTERN COLORADO GETS PUSHED
SOUTH AND EAST OF THE AREA...THOUGH ENOUGH MOISTURE TO REMAIN
UNDERNEATH BUILDING RIDGE TO SUPPORT MORE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA...WITH BEST COVERAGE OVER
THE HIGHER TERRAIN. LATEST NAM CONTINUES TO INDICATED STORMS FIRING
ALONG OLD BOUNDARY ACROSS THE NEW MEXICO BORDER IN THE LATE
AFTERNOON WITH THE GFS KEEPING THE BOUNDARY WELL SOUTH OF THE AREA.
AT ANY RATE...HAVE KEPT ISOLATED POPS ACROSS THE FAR SOUTHEAST
PLAINS WITH CONVECTIVE TEMPS IN THE MID 90S BEING REACHED. WITH
DRIER AIR ACROSS REGION...HEAVY RAIN THREAT DIMINISHES...THOUGH A
LOCALLY HEAVY RAINER WILL STILL BE POSSIBLE WITH THE WEAK FLOW ALOFT.
TEMPERATURES LOOK TO BE AROUND OR SLIGHTLY WARMER THAN TODAY. -MW
.LONG TERM...
STAGNANT WX PATTERN WILL BE OVER THE REGION DURING THIS FCST PD.
CENTER OF MID LVL HI PRESSURE SYSTEM WILL DEVELOP PRETTY MUCH OVER
THE E PLAINS OF CO. THIS WILL FORCE THE MAIN MSTR PLUME TO THE WEST
OF THE FCST AREA...GENERALLY FROM THE CONTDVD ON WEST. EAST OF THE
CONTDVD IT WILL GENERALLY BE DRY...ESPECIALLY OVER THE PLAINS. WITH
THE HIGH DIRECTLY OVERHEAD...MAX TEMPERATURES ON THE PLAINS WILL
LIKELY GET UP INTO THE 100S AND REMAIN THERE THROUGHOUT THE FCST PD.
OVERALL THROUGH THIS FCST PD...I EXPECT SCTD AFTERNOON POPS OVER
THE CONTDVD...ISOLD POPS OVER THE REST OF THE MTNS AND VALLEYS...AND
HOT AND DRY ELSEWHERE.
GIVEN THE LOCATION OF THE MID LEVEL HIGH PRESSURE CELL DURING THIS
PERIOD...THE PROBABILITY OF FLASH FLOODING OVER THE WALDO BURN SCAR
WILL LIKELY BE LESS THAN NORMAL. /HODANISH
&&
.AVIATION...
ISOLATED TO SCATTERED STORMS TO REMAIN POSSIBLE ACROSS THE HIGHER
TERRAIN THROUGH THE EARLY EVENING...WITH A FEW STORMS SPREAD EAST
ACROSS THE IMMEDIATE ADJACENT PLAINS. BEST CHANCES OF AFFECTING
TERMINALS STILL REMAINS AT COS THROUGH 02Z WITH BRIEF MVFR CIGS AND
VIS ALONG WITH GUSTY OUTFLOW WINDS OF 25-35KTS POSSIBLE WITH STORMS.
VFR CONDITIONS WITH CLEARING SKIES AFT 06Z. AFTERNOON CONVECTION
TOMORROW TO REMAIN MORE OVER THE HIGHER TERRAIN. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/34
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICEABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A NICE START TO THE WEEKEND AS A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION ON SATURDAY. THE GFS WANTS TO LINGER ONTO THE UPPER TROF
AXIS AND RESULTS IN ISOLATED CONVECTION ACROSS THE REGION.
HOWEVER...THE GFS ALSO HINTS AT RISING HEIGHTS WHICH IS ALONG THE
SAME AS OTHER GLOBAL GUIDANCE. WE WILL RETAIN THE DRY FORECAST
ALONG WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
THEN TRENDS ON SUNDAY ARE BECOMING A LITTLE MORE ACTIVE...BUT NOT A
WASHOUT. ANOTHER SHORTWAVE WITHIN THE NORTHWEST FLOW REGIME ALOFT
IS EXPECTED TO TRACK TOWARD THE GREAT LAKES REGION LATER ON SUNDAY.
AT THIS TIME...WE WILL INTRODUCE A SLIGHT CHANCE FOR CONVECTION AND
CONTINUE TO MONITOR TRENDS. BY SUNDAY NIGHT...ALL OF THE AVAILABLE
GUIDANCE SUGGESTS A PV ANOMALY CROSSES THE REGION. WE WILL HAVE THE
HIGHER POPS...30-40 PERCENT...AT THIS TIME ACROSS MOST OF THE REGION
SUNDAY NIGHT.
BY MONDAY...THAT PV ANOMALY DOES TRACK EAST YET THE CYCLONIC FLOW
REGIME REMAINS IN PLACE. THE ECMWF/DGEX WANTS TO LINGER A SURFACE
TROUGH ACROSS THE REGION WHILE THE GFS IS THE MOST AGGRESSIVE TO
CLEAR OUT OF OUR SOUTHERN COUNTIES. HPC GUIDANCE IS SOMEWHAT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE AND HAVE FOLLOWED THE GUIDANCE
CLOSELY. TEMPERATURES AND DEWPOINTS WILL BE ON THE CLIMB AS WELL AS
WE AVERAGE TOWARD ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO FAR NORTHERN
AREAS LATER TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH FROM
CANADA. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER
SOUTH BUT TO LOW OF PROBABILITY TO MENTION IN A TAF. INCREASING
SOUTHWEST WINDS ARE EXPECTED TO RESULT IN DOWNSLOPING IN THE HUDSON
VALLEY WHICH SHOULD ALSO HELP LIMIT CONVECTIVE ACTIVITY FOR MOST OF
THE TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE AT KGFL LATE
THIS AFTERNOON INTO EARLY THIS EVENING. MODELS SHOW MOST CONVECTION
DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND FOG AND
STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT. FOR
TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE OF
THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES SOUTH.
SOUTHWEST WINDS 10 TO 15 KTS BY AFTERNOON SUBSIDING TO 3 TO 6 KTS
THIS EVENING. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONIGHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...BGM
AVIATION...
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MAINLY DRY CONDITIONS WITH TEMPS AVERAGING NEAR NORMAL ARE EXPECTED
DURING THE LONG TERM PERIOD.
A LARGE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS OUR REGION FROM
SOUTHERN CANADA ON FRIDAY AND SETTLE ACROSS OUR REGION ON SATURDAY
BEFORE SLIDING OFF THE EASTERN SEABOARD ON SUNDAY. A COLD FRONT IS
THEN EXPECTED TO DROP SOUTHEAST THROUGH OUR REGION FROM SOUTHERN
CANADA ON MONDAY. HOWEVER IT APPEAR AT THIS TIME THAT VERY LITTLE
MOISTURE EXISTS WITH THIS SYSTEM AND THE FRONTAL PASSAGE MAY OCCUR
WITH LITTLE IF ANY PCPN. H8 TEMPS GENERALLY REMAIN BETWEEN +10 AND
+14C UNTIL SUNDAY AFTERNOON WHEN VALUES RISE TO +15 TO +17 C AS
RETURN FLOW SETS UP WITH HIGH SLIDING OFF THE COAST TO OUR
SOUTHEAST. H8 TEMPS THEN ARE EXPECTED TO START FALLING BY MONDAY
AFTERNOON ACROSS NORTHERN HALF OF FA IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON FRIDAY IN THE 70S TO AROUND 80...MID 70S TO LOWER
80S ON SATURDAY...MAINLY UPPER 70S TO MID 80S ON SUNDAY AND MONDAY.
LOWS ARE EXPECTED TO BE IN THE UPPER 40S TO UPPER 50S FRIDAY
NIGHT...50S TO AROUND 60 SATURDAY NIGHT...AND MID 50S TO MID 60S
SUNDAY NIGHT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO FAR NORTHERN
AREAS LATER TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH FROM
CANADA. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER
SOUTH BUT TO LOW OF PROBABILITY TO MENTION IN A TAF. INCREASING
SOUTHWEST WINDS ARE EXPECTED TO RESULT IN DOWNSLOPING IN THE HUDSON
VALLEY WHICH SHOULD ALSO HELP LIMIT CONVECTIVE ACTIVITY FOR MOST OF
THE TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE AT KGFL LATE
THIS AFTERNOON INTO EARLY THIS EVENING. MODELS SHOW MOST CONVECTION
DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND FOG AND
STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT. FOR
TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE OF
THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES SOUTH.
SOUTHWEST WINDS 10 TO 15 KTS BY AFTERNOON SUBSIDING TO 3 TO 6 KTS
THIS EVENING. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONGIHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...11
AVIATION...11
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1205 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
...THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
WEDNESDAY...COMPLICATED CONVECTIVE FORECAST ONCE AGAIN. SPC JUST
CONTINUED THE SLIGHT RISK WHERE THEY LEFT OFF FROM DAY 1.
JUXTAPOSITION OF BEST SHEAR AND CAPE FROM THE ASSORTED GUIDANCE
INDICATES THE LIKELY LOCATIONS FOR A LARGE HAIL AND DAMAGING WIND
THREAT WILL BE SOUTH OF ALBANY...WHERE AN ABUNDANCE OF INSTABILITY
MAY BE IN PLACE WITH SBCAPES OF 1500-3500 J/KG /DUE TO SFC DEWPTS
IN THE L70S/. WE WILL MENTION FROM THE CAPITAL REGION SOUTH IN THE
HWO FOR A SEVERE WEATHER THREAT. LIFTED INDICES ARE IN THE -4C TO
-8C RANGE. ALSO...A SECOND SPEED MAX WILL BE MOVING THROUGH THE
MID AND UPPER JET ALOFT. PORTIONS OF THE ALY FCST AREA WILL BE IN
THE RIGHT REAR QUADRANT OF THE JET STREAK. DEEP ORGANIZED LOOKS
POSSIBLE WITH BULK SHEAR VALUES IN THE 0-6 KM LAYER AROUND 40 KTS
AGAIN.
THE QUESTION WILL BE HOW MUCH HEATING WILL OCCUR WITH CLOUDS
AROUND. IT IS LIKELY SOME ISOLATION WITH OCCURS WITH THUNDERSTORMS
OCCURRING QUICKLY...A MID LEVEL SHORT-WAVE SLICES THROUGH THE
REGION VIA THE GFS/CAN/NAM. THIS ACTUALLY LOOKS LIKE A BETTER CHC
FOR SOME SVR THUNDERSTORMS ON THIS DAY WITH A FEW CLUSTERS OR
LINES. MAX TEMPS WILL RANGE FROM THE U70S AND L80S OVER THE NRN
ZONES...TO THE M80S TO NEAR 90F FROM THE CAPITAL REGION SOUTH. IT
SHOULD ALSO BE EMPHASIZED THAT THE PWATS WILL BE A FEW STANDARD
DEVIATIONS ABOVE NORMAL IN THE 1.50-2.00 INCH RANGE. SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA. HEAT INDICES REMAINED BELOW ADVISORY CRITERIA OVER
THE MID HUDSON VALLEY...AND NW CT...WITH MAINLY 90S.
WED NIGHT...THE FRONT SLOWLY SAGS SOUTH OF THE AREA...AS COOLER
AND DRIER AIR MOVES INTO THE REGION. WE DIMINISHED THE SHOWERS AND
THUNDERSTORMS AROUND MIDNIGHT FROM ALY SOUTH...AND JUST KEPT A
SLIGHT CHC OF SHOWERS IN OVERNIGHT. HUMIDITY LEVELS WILL LEAVE THE
OPPRESSIVE CATEGORY. LOWS WILL RANGE FROM THE LOWER TO M60S FROM
THE CAPITAL REGION SOUTH AND EAST...AND MAINLY 50S NORTH AND WEST.
THU-THU NIGHT...LOW LEVEL COLD ADVECTION CONTINUES OVER THE FCST
AREA WITH H850 VALUES OF 10C TO 15C FROM THE NW TO SE. A LARGE
DOME OF CANADIAN HIGH PRESSURE BUILDS DOWN FROM JAMES BAY. ASIDE
FROM SOME FAIR WX CUMULUS...IT SHOULD BE A SEASONABLE MID JULY DAY
WITH COMFORTABLE HUMIDITY LEVELS. WE CONTINUED THE DRY WX INTO THU
NIGHT...THOUGH THE NAM TRIES TO RUN A DISTURBANCE CLOSE TO REGION
WITH SOME SHOWERS/TSTMS. WE INCREASED THE CLOUDS OVER THE SRN
TIER...BUT WE DID NOT BUY INTO THIS POSSIBLE CONVECTIVE FEEDBACK
DISTURBANCE. LOWS WILL MAINLY BE IN THE 50S...WITH SOME U40S OVER
THE SRN DACKS...AND GREENS...AND SOME L60S OVER THE MID HUDSON
VALLEY...AND SRN LITCHFIELD CTY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MAINLY DRY CONDITIONS WITH TEMPS AVERAGING NEAR NORMAL ARE EXPECTED
DURING THE LONG TERM PERIOD.
A LARGE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS OUR REGION FROM
SOUTHERN CANADA ON FRIDAY AND SETTLE ACROSS OUR REGION ON SATURDAY
BEFORE SLIDING OFF THE EASTERN SEABOARD ON SUNDAY. A COLD FRONT IS
THEN EXPECTED TO DROP SOUTHEAST THROUGH OUR REGION FROM SOUTHERN
CANADA ON MONDAY. HOWEVER IT APPEAR AT THIS TIME THAT VERY LITTLE
MOISTURE EXISTS WITH THIS SYSTEM AND THE FRONTAL PASSAGE MAY OCCUR
WITH LITTLE IF ANY PCPN. H8 TEMPS GENERALLY REMAIN BETWEEN +10 AND
+14C UNTIL SUNDAY AFTERNOON WHEN VALUES RISE TO +15 TO +17 C AS
RETURN FLOW SETS UP WITH HIGH SLIDING OFF THE COAST TO OUR
SOUTHEAST. H8 TEMPS THEN ARE EXPECTED TO START FALLING BY MONDAY
AFTERNOON ACROSS NORTHERN HALF OF FA IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON FRIDAY IN THE 70S TO AROUND 80...MID 70S TO LOWER
80S ON SATURDAY...MAINLY UPPER 70S TO MID 80S ON SUNDAY AND MONDAY.
LOWS ARE EXPECTED TO BE IN THE UPPER 40S TO UPPER 50S FRIDAY
NIGHT...50S TO AROUND 60 SATURDAY NIGHT...AND MID 50S TO MID 60S
SUNDAY NIGHT.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MID AND HIGH CLOUDS ARE EXPECTED TO GRADUALLY INCREASE ACROSS THE
TAF SITES THROUGH THIS MORNING WITH HOT AND BREEZY CONDITIONS
DEVELOPING BY THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL BE
PRIMARILY CONFINED TO FAR NORTHERN AREAS AS WELL AS SOME OF THE
HIGHER TERRAIN. INCREASING SOUTHWEST WINDS ARE EXPECTED TO RESULT IN
DOWNSLOPING IN THE HUDSON VALLEY WHICH SHOULD LIMIT CONVECTIVE
ACTIVITY FOR MOST OF THE TAF SITES. SINCE THE BEST CHANCE OF
THUNDERSTORMS WILL BE AT KGFL LATE THIS AFTERNOON INTO EARLY THIS
EVENING WILL LEAVE PROB 30 IN AT KGFL.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWEST BY MID MORNING AND
INCREASE TO 10 TO 15 KTS BY AFTERNOON AND THEN SUBSIDE TO 3 TO 6 KTS
THIS EVENING.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU-SAT...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A HOT AIR MASS WILL BE OVER NEW YORK AND NEW ENGLAND
TODAY. A COLD FRONT WILL APPROACH FROM THE NORTH THIS AFTERNOON AND
EVENING WITH A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY NORTH AND
WEST OF THE CAPITAL REGION. THE FRONTAL BOUNDARY WILL SLOWLY DRIFT
SOUTH OF THE CAPITAL REGION ON WEDNESDAY WITH MORE SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN ON THURSDAY FROM ONTARIO
AND THE GREAT LAKES REGION WITH DRY WEATHER INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL BE IN THE 25 TO 45 PERCENT RANGE
THIS AFTERNOON...THEN INCREASE TO 85 TO 100 PERCENT TONIGHT.
EXPECT THE RH VALUES TO BE HIGHER ON WEDNESDAY AFTERNOON IN THE 40
TO 55 PERCENT RANGE.
THE WINDS WILL INCREASE FROM THE SOUTHWEST TO WEST AT 10 TO 20 MPH
WITH SOME GUSTS AROUND 25 TO 30 MPH THIS AFTERNOON. THE WINDS WILL BE
LIGHT AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM
THE WEST NORTHWEST AT 5 TO 15 MPH ON WEDNESDAY WITH THE FRONTAL
PASSAGE.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TUESDAY THROUGH WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO
A SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN
THE 1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
355 AM EDT TUE JUL 17 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A VERY SUMMER-LIKE UPPER
LEVEL PATTERN IN PLACE OVER THE CENTRAL AND EASTERN CONUS. A FAST
NORTHERN STREAM FLOW IS BEGIN HELD WELL TO THE NORTH ACROSS SOUTHERN
CANADA BY A LARGE AND DOMINANT UPPER LEVEL RIDGE ALIGNED OVER THE MS
VALLEY. ANOTHER LARGE AREA OF UPPER LEVEL RIDGING IS CENTERED TO THE
NORTHEAST OF THE BAHAMAS...AND THIS FEATURE WILL BECOME THE DOMINANT
PLAYER IN OUR WEATHER FOR THE SECOND HALF OF THE WEEK. IN BETWEEN
THESE FEATURES...WE STILL FIND A TUTT (TROPICAL UPPER TROPOSPHERIC
TROUGH) CELL ROTATING SLOWLY WESTWARD ACROSS NORTHERN FLORIDA. THE
TUTT IS CURRENTLY CENTERED JUST TO THE WEST OF JACKSONVILLE AND WILL
ONLY VERY SLOWLY MIGRATE WESTWARD TOWARD THE SUWANNEE RIVER VALLEY
THROUGH THE DAY. SYNOPTIC SUPPORT ASSOCIATED WITH THIS TUTT CELL
COMBINED WITH THE LEADING EDGE OF AN ASSOCIATED RELATIVELY COLD
MID-LEVEL POCKET OF AIR HAS BEEN FORCING AN AXIS OF CONVECTION EARLY
THIS MORNING FROM APALACHEE BAY SE INTO THE TAMPA BAY AREA. AS WE
HEAD TOWARD DAWN...THE MAJORITY OF THE CONVECTION SHOULD SHIFT TO
THE COASTAL WATERS...HOWEVER DUE TO THE UPPER SUPPORT...CAN NOT RULE
OUT SHOWERS FOR THE COASTAL LAND ZONES.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS ALIGNED OVER THE SOUTHERN
HALF OF FL PENINSULA THIS MORNING...AND THIS GENERAL POSITION IS
EXPECTED TO HOLD THROUGH THE SHORT TERM FORECAST PERIOD.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY...TUTT CELL WILL CONTINUE TO INFLUENCE MAINLY THE CENTRAL
AND NORTHERN PORTIONS OF THE FORECAST AREA WITH SOME SYNOPTIC LIFT
AND ENHANCED INSTABILITY FROM ITS ASSOCIATED COOL POOL. THIS
INFLUENCE WILL BE FELT MOSTLY IN THE POTENTIAL FOR A FEW STRONGER
STORMS WITH SMALL HAIL AND FREQUENT LIGHTNING. SOUTH OF THE I-4
CORRIDOR...WHILE THE POTENTIAL FOR STRONGER STORMS WILL BE LESS...A
MOIST ATMOSPHERE AND DEVELOPING SEA-BREEZES WILL STILL ALLOW FOR A
GOOD COVERAGE OF DIURNAL CONVECTION. IN FACT...THE GFS IS SHOWING PW
VALUES REMAINING ABOVE 2" FOR THE SOUTHERN ZONES WHICH MAY LEAD TO
SOME HEAVY RAINFALL POTENTIAL. WE SAW THIS ON MONDAY OVER HIGHLANDS
COUNTY AND SIMILAR ATMOSPHERIC CONDITIONS WILL AGAIN LEAD TO THIS
LOCALIZED THREAT.
TONIGHT...TUTT CELL WILL BEGIN TO WEAKEN AND LIFT OUT TO THE NORTH.
LINGERING SCATTERED STORMS OVER THE INTERIOR SHOULD BE DIMINISHING
DURING THE LATE EVENING HOURS. AFTER MIDNIGHT EXPECT A SCATTERING OF
NOCTURNAL SHOWERS/STORMS TO DEVELOP OVER THE COASTAL WATERS. LOW
LEVEL FLOW WILL FAVOR THE BEST CHANCES FOR THESE STORMS TO MIGRATE
BACK TO THE COAST FROM MANATEE COUNTY NORTHWARD ALONG THE NATURE
COAST.
WEDNESDAY...HEIGHTS WILL BE BUILDING OVER THE PENINSULA AS UPPER
LEVEL RIDGING EXPANDS WESTWARD FROM THE BAHAMAS. A SIGNIFICANTLY
DRIER COLUMN ASSOCIATED WITH THIS FEATURE`S SUPPRESSION WILL BE
EXPANDING INTO SOUTHERN FLORIDA...HOWEVER IT APPEARS AS THOUGH THE
INFLUENCE OF THIS AIRMASS WILL REMAIN SOUTH OF OUR ZONES FOR THE
DAYLIGHT HOURS. EXPECT THE SCATTERED NOCTURNAL SHOWERS NEAR THE
COAST TO CONTINUE DURING THE MORNING HOURS AND SLOWLY BEGIN TO
MIGRATE INLAND. ONCE SEA-BREEZE CIRCULATIONS BECOME ESTABLISHED...
WILL EXPECT MORE ROBUST DEEP CONVECTION TO DEVELOP. THE GREATEST
CHANCES FOR THESE STORMS WILL BE SLIDING INLAND AS THE AFTERNOON
PROGRESSES WITH THE BEACHES LIKELY BECOMING MOSTLY DRY AFTER MID
AFTERNOON. THE BUILDING HEIGHTS WILL ALLOW HIGH TEMPS TO START
RISING A COUPLE DEGREES AS WELL.
THURSDAY...STACKED RIDGING WILL BE WELL ESTABLISHED OVER THE
FORECAST AREA. MAY SEE A FEW MORE NOCTURNAL SHOWERS OVER THE COASTAL
WATERS...WITH THE BEST CHANCES FOR ANY INLAND PENETRATION DURING THE
EARLY MORNING HOURS NORTH OF THE TAMPA BAY AREA. BY AFTERNOON...THE
SEA-BREEZE WILL BE PUSHING INLAND AND LIKELY ONCE AGAIN TAKING THE
MAJORITY OF THE SHOWERS/STORMS INLAND WITH IT. BEST CHANCES FOR THE
AFTERNOON STORMS WILL BE NORTH OF THE 1-4 CORRIDOR IN ASSOCIATED
WITH SOME STILL DECENT COLUMN MOISTURE. SOUTH OF I-4...A MUCH DRIER
AND MORE HOSTILE COLUMN FOR DEEP CONVECTION LOOKS TO BECOME
ESTABLISHED. WILL ONLY HIGHLIGHT WIDELY SCT STORMS FOR THESE INLAND
ZONES. TEMPERATURES SHOULD BE NOTICEABLY WARMER WAS WELL WITH
WIDESPREAD MIDDLE 90S AWAY FROM THE BEACHES.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
SUB-TROPICAL RIDGE WILL BE
WELL ESTABLISHED OVER THE REGION THURSDAY NIGHT AND FRIDAY WITH SLUG
OF DRY AIR LIFTING NORTHWARD ACROSS THE REGION. WILL CONTINUE WITH
JUST A SLIGHT CHANCE OF AFTERNOON STORMS WHICH IS AT OR ABOVE 00Z
MEX GUIDANCE POPS WHICH SHOW POPS BELOW 15 PERCENT SOUTH OF TAMPA
BAY.
THE TRICKY PART OF THE FORECAST WILL BE IN THE RETURN OF MOISTURE
FROM THE SOUTH. THE SUB-TROPICAL RIDGE REMAINS STRONG OVER CENTRAL
FLORIDA WHICH WILL SERVE TO SUPPRESS AFTERNOON STORMS. BUT ITS HARD
TO IGNORE PRECIPITABLE WATERS OF OVER TWO INCHES AS WELL. DRY SLOT
ON SATURDAY IS FORECAST TO BE IN PLACE FROM THE TAMPA BAY AREA
NORTHWARD THROUGH PORTIONS OF THE NATURE COAST. OTHERWISE...HIGHER
MOISTURE WARRANTS AT LEAST A CHANCE OF AFTERNOON STORMS WITH RAIN
CHANCES NEAR 30 PERCENT AROUND FORT MYERS.
DECIDED TO STAY A BIT ABOVE GUIDANCE FOR RAIN CHANCES ON SUNDAY AND
MONDAY. THE STORY REMAINS THE SAME...HIGH MOISTURE AVAILABILITY WILL
BE OFFSET BY SUBSIDENCE UNDER THE STRONG SUB-TROPICAL RIDGE. WILL
KEEP AFTERNOON RAIN CHANCES AROUND 40 PERCENT...WHICH IS A BIT ABOVE
GUIDANCE BUT NEAR OR EVEN A BIT BELOW NORMAL FOR THIS TIME OF YEAR.
WITH THE STRONG SUB-TROPICAL RIDGE OVERHEAD...TEMPERATURES WILL SOAR
GIVEN ENOUGH SUNSHINE...ESPECIALLY AWAY FROM THE INFLUENCE OF THE
SEA BREEZES. I WOULD NOT BE SURPRISED TO SEE SOME UPPER 90S ACROSS
THE INTERIOR OVER THE WEEKEND.
&&
.AVIATION...
PERSISTENT AREA OF SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO
IMPACT PIE AND SRQ THROUGH THE EARLY MORNING HOURS. FMY AND RSW MAY
SEE A FEW MORNING SHOWERS...BUT BEST CHANCE AT MVFR/IFR CONDITIONS
WILL OCCUR AFTER 16Z. CONFIDENCE IN TIMING STILL TOO LOW TO
INTRODUCE TEMPO GROUPS FOR THE AFTERNOON HOURS.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN ALIGNED ACROSS THE SOUTHERN
FLORIDA PENINSULA INTO THE EASTERN GULF OF MEXICO THROUGH THE NEXT
SEVERAL DAYS. THIS RIDGE POSITION WILL KEEP WINDS AND SEAS LOW
THROUGH THE PERIOD. LATE NIGHT AND EARLY MORNING SHOWERS AND STORMS
WILL BE FAIRLY COMMON OVER THE COASTAL WATERS THE NEXT COUPLE OF
NIGHTS.
&&
.FIRE WEATHER...
ABUNDANT LOW LEVEL MOISTURE WILL KEEP RELATIVE HUMIDITY LEVELS WELL
ABOVE CRITICAL VALUES THROUGH AT LEAST THURSDAY. NO SIGNIFICANT FIRE
WEATHER CONCERNS ARE ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 77 90 77 / 50 30 40 20
FMY 90 75 91 76 / 50 20 40 10
GIF 91 73 93 74 / 60 30 50 30
SRQ 89 76 90 76 / 40 30 30 10
BKV 90 71 92 72 / 50 30 50 20
SPG 89 79 90 80 / 40 30 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EDT TUE JUL 17 2012
.DISCUSSION...
TODAY-TONIGHT...
LATEST RAP ANALYSIS SHOWS A GENERAL DECREASE IN INSTABILITY OVER THE
PAST 24HRS. THE MID LVL VORTICITY FIELD OVER FL HAS BECOME SOMEWHAT
DISORGANIZED WITH NOTEWORTHY MAXES OVER N AND S PENINSULA...
SEPARATED BY AN ELONGATED MIN ALONG THE I-4 CORRIDOR. TEMPS ALOFT
HAVE WARMED A BIT WITH H50 READINGS NEAR -8C AREAWIDE. UPR LVL
DIVERGENCE FIELD HAS WEAKENED AS WELL. EVEN SO...EVENING SOUNDINGS
SHOW THE LCL AIRMASS REMAINS NEARLY SATURATED THRU THE H100-H50 LYR
WITH PW VALUES ARND 2.2" AT KTBW/KMFL. THE ATLC RIDGE AXIS IS PARKED
OVER THE FL STRAITS AND WILL INTERACT WITH AN INVERTED TROF AXIS
EXTENDING FROM THE CAROLINA COAST TO JUST N OF THE YUCATAN PENINSULA
TO PRODUCE A DEEP LYR SW FLOW ACRS CENTRAL FL.
THE TROF WILL DRIFT SLOWLY NWD THRU TONIGHT AS ANTICYCLONIC
CIRCULATIONS OVER THE DEEP S AND E OF THE BAHAMAS SQUEEZE IT FROM
BOTH FLANKS. AS A RESULT...DESPITE DECREASING INSTABILITY...CENTRAL
FL WILL REMAIN ON THE ASCENDING RIGHT SIDE OF THE TROF. THE LCL
AIRMASS REMAINS PRIMED FOR ANOTHER ROUND OF HIGH PRECIP COVERAGE
THIS AFTN WITH DEEP LOW/MID LVL MOISTURE IN PLACE. THE SWRLY
STEERING FLOW WILL FAVOR THE E FL COAST FOR TOTAL COVERAGE...MAINLY
N OF SEBASTIAN INLET AS THE W/SW FLOW WILL PLACE MARTIN/ST. LUCIE
CO. IN THE SHADOW OF LAKE OKEECHOBEE. THOUGH THE H75-H60 LYR
CONTINUES TO DISPLAY SOME RESPECTABLE LAPSE RATES...THE OVERALL
THREAT FOR STRG/SVR WX HAS DIMINISHED. PRIMARY WX THREATS WILL BE CG
LIGHTNING AND LCL FLOODING.
SCT SHRAS/ISOLD TSRAS WILL LINGER INTO THE EVENING AS THE INVERTED
TROF PUSHES NWD AND MERGES WITH A SHORT WAVE TROF OVER THE MID
ATLC/NEW ENGLAND SEABOARD. THIS WILL LEAVE THE LCL AIRMASS WITH
LITTLE TO NO DYNAMIC SUPPORT BEYOND LCL DIURNAL HEATING...THUS ANY
PRECIP SHOULD DISSIPATE BEFORE MIDNIGHT. NO CHANGE IN LOW LVL
AIRMASS... MAX/MIN TEMPS WILL BE WITHIN A DEG OR TWO OF MONDAY
READINGS.
WED-THU...MID/UPPER LEVEL CUT OFF LOW IS PROGGED TO LIFT SLOWLY
NORTH OVER GEORGIA ON WED THEN SHEAR OUT THU AS BROAD TROUGH TAKES
SHAPE OVER THE EASTERN HALF OF THE COUNTRY. HIGH MOISTURE WILL
CONTINUE ON WED ALONG WITH WESTERLY STEERING FLOW...SO HAVE GONE
ABOUT 10 PERCENT ABOVE MOS POPS.
DEEP LAYER RIDGING IS FORECAST TO BUILD IN OVER THE SOUTH CENTRAL
PENINSULA ON THU. SOME DRYING SHOULD AFFECT THE SOUTH BUT HIGHER
MOISTURE IS STILL SHOWN BY THE GFS ACROSS THE NORTH HALF. MOS POPS
ARE 20 PERCENT OR LESS AREAWIDE...BUT HAVE GONE WITH 30 PERCENT
ACROSS THE NORTH HALF WHERE MOISTURE AND WESTERLY STEERING STILL
SHOULD BE ABLE TO BRING SCATTERED COVERAGE TO THE EASTERN SIDE OF
THE PENINSULA.
A LITTLE MORE SUNSHINE WILL ALLOW MAX TEMPERATURES TO CLIMB INTO
THE MID 90S ACROSS THE INTERIOR AND POSSIBLY THE NORTH COAST WHERE
THE SEA BREEZE SHOULD BE INHIBITED.
FRI-SAT...DEEP LAYER RIDGE AXIS IS STILL FORECAST TO BUILD A
LITTLE FARTHER NORTH TO THE CENTRAL PENINSULA FRI WITH CONTINUED
DRYING WORKING UP FROM THE SOUTH. THE EAST/WEST COAST BOUNDARY
COLLISION ACROSS THE INTERIOR AND NORTH COAST SHOULD GENERATE
ISOLATED STORMS LATE IN THE DAY AND HAVE GONE WITH 20 PERCENT POPS
THERE. THE SPACE AND TREASURE COAST SHOULD ESCAPE STORMS ON FRI.
THE SAME GENERAL PATTERN WILL CONTINUE INTO SAT...THOUGH THE 00Z
GFS INDICATES SOME MOISTURE LIFTING INTO SOUTHERN SECTIONS. MOS
POPS ARE 25 TO 30 PERCENT AREAWIDE ON SAT BUT HAVE JUST INDICATED
20 PERCENT FOR NOW.
LITTLE CHANGE IN MAX TEMPERATURES...LOW-MID 90S...BUT WITH LOW
COVERAGE AND LATE OCCURRENCE OF STORMS...IT WILL FEEL HOTTER.
SUN-TUE...TROUGHING OVER THE EASTERN PART OF THE COUNTRY WILL KEEP
DEEP LAYER RIDGE AXIS DRAPED ACROSS THE FLORIDA PENINSULA. THE 00Z
GFS/ECMWF SHOW HIGHER MOISTURE LIFTING BACK ACROSS THE ENTIRE
AREA ON SUNDAY AND CONTINUING INTO MON. THIS SHOULD BRING A
TYPICAL SCATTERED COVERAGE OF AFTERNOON SHOWERS/STORMS...WITH
INTERIOR SECTIONS THE MOST FAVORED. THE MODELS INDICATE SOME
DRYING WORKING IN FROM THE SOUTHEAST TUE...BUT WILL NOT DEVIATE
FROM THE MOS POPS WHICH ARE 30-40 PERCENT.
&&
.AVIATION...
THRU 17/15Z...BRIEF IFR CIGS/MVFR VSBYS IN BR N OF KISM-KTTS...VCSH
S OF KFPR-KOBE WITH OCNL CIGS BTWN FL040-060...VFR ELSEWHERE.
BTWN 17/15Z-17/18Z...SFC WNDSHFT FROM SW TO S/SE COASTAL SITES
ASSOCD WITH THE E COAST SEA BREEZE...SEA BREEZE NOT EXPECTED TO
ADVANCE PAST THE I-95 CORRIDOR....SCT MVFR SHRAS/ISOLD IFR TSRAS ALL
SITES.
BTWN 17/18Z-17/24Z...VCTS ALL SITES WITH NMRS MVFR SHRAS AND SCT IFR
TSRAS DVLPG AREAWIDE...OCNL SFC WND G22KTS NEAR TSRAS.
BTWN 18/00Z-18/03Z...VCSH ALL SITES WITH SCT MVFR SHRAS AND ISOLD
IFR TSRAS.
AFT 18/03Z...PREVAILING VFR ALL SITES WITH CIGS AOA FL120...BRIEF
IFR CIGS N OF KISM-KEVB.
&&
.MARINE...
TODAY-TONIGHT...ATLC RIDGE OVER THE FL STRAITS WILL GENERATE A LIGHT
TO GENTLE SW BREEZE AREAWIDE. WINDS WILL VEER TO THE S/SE NEAR THE
COAST IN THE AFTN AS THE EAST COAST SEA BREEZE FORMS...BUT WILL
SHIFT BACK TO THE SW SHORTLY AFT SUNSET. INCREASED POTENTIAL FOR
OFFSHORE MOVING TSTMS...ESPECIALLY N OF SEBASTIAN INLET. SEAS
2-3FT NEARSHORE AND 3-4FT OFFSHORE...LARGELY IN AN ERLY SWELL.
DOMINANT PDS BTWN 9-10 SEC.
WED-THU...SOUTH/SOUTHWEST FLOW SHOULD PERSIST AS AXIS OF ATLANTIC
SURFACE RIDGE LIFTS SLOWLY TOWARDS THE CENTRAL PENINSULA. SPEEDS
SHOULD BE AROUND 10 KNOTS...WITH SOME NOCTURNAL INCREASE TO 10-15
KNOTS ACROSS NORTHERN SECTIONS. SCATTERED STORMS ARE EXPECTED TO
PUSH OFF THE MAINLAND ON WED AND POSSIBLE AGAIN ON THU FROM ABOUT
SEBASTIAN INLET NORTH.
FRI-SAT...VERY LITTLE CHANGE IN THE SURFACE RIDGE POSITION AND
HENCE THE WINDS. WEAKER STEERING LEVEL WINDS AND DRIER AIR SHOULD
INHIBIT STORMS FROM AFFECTING THE ATLANTIC.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 74 93 76 / 70 40 50 20
MCO 91 74 94 75 / 60 30 50 20
MLB 89 74 92 75 / 70 40 50 20
VRB 89 73 92 76 / 70 40 40 20
LEE 91 75 94 77 / 60 30 50 20
SFB 92 75 95 77 / 60 30 50 20
ORL 91 75 95 78 / 60 30 50 20
FPR 89 74 91 75 / 60 40 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
345 PM EDT TUE JUL 17 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
COLD FRONT IS WELL TO THE SOUTH OF UPPER MICHIGAN AS PORTIONS OF
SOUTHERN WICSONSIN AND LOWER MICHIGAN CONTINUE TO BAKE. YET...DRY
DAY THAT WAS SUPPOSED TO BE OVER MOST OF THE AREA HAS HAD TOUGH TIME
TAKING SHAPE. MAIN CULPRIT FOR THE SHRA CURRENTLY ROAMING CNTRL UPR
MICHIGAN SEEMS TO HAVE BEEN A SUBTLE H6-H5 JET STREAK ALONG WITH
RIBBON OF LINGERING HIGHER H7 DWPNTS ACROSS THE AREA. ADDITIONAL
LIFT IS PROVIDED BY A WEAK SHORTWAVE NOW PUSHING INTO WESTERN LK
SUPERIOR. BULK OF ANY TSRA HAVE STAYED OVR NORTHERN WISCONSIN ALONG
NORTH EDGE OF 1-6KM MUCAPE GRADIENT. SHRA IN THE NORTH HAVE NOT
BEEN ALL THAT HEAVY...WITH ONLY A FEW HUNDREDTHS OBSERVED AT RAIN
GAGES OVR WESTERN UPR MICHIGAN THIS AFTN. EXPECT ALL THE MENTIONED
FORCING MECHANISMS TO DRIFT SOUTH OUT OF THE AREA EARLY THIS EVENING
AND HAVE PUT AN END TO POPS AT THAT TIME. RAPID REFRESH RUC MODEL
/HRRR/ WHICH DID NOT DO WELL SHOWING THE SHRA/TSRA FOR MUCH OF THE
MORNING FINALLY CAUGHT ON BY EARLY THIS AFTN...AND FCSTS A SIMILAR
FATE TO PRECIP THIS EVENING.
CLEARING SKIES THEN EXPECTED FM NORTHWEST TO SOUTHEAST THROUGH THE
EVENING. THINK THE CLEARING COULD LEAD TO FOG OVERNIGHT TONIGHT
THROUGH EARLY WEDNESDAY MORNING. PLUSES FOR FOG FORMATION ARE ADDED
SFC MOISTURE FROM THE RAIN TODAY/MINIMAL MIXING OR DRYING TODAY
ALONG WITH FAIRLY LIGHT WINDS/COOLING TEMPS. BEST CHANCE FOR FOG
WILL BE OVER WEST HALF AND ALSO WHERE NORTHEAST WINDS UPSLOPE
/HIGHER TERRAIN OF WEST AND NORTH CENTRAL/. LOOKS LIKE AM ON MY
OWN ON THIS ONE THOUGH AS NO GUIDANCE HAS REALLY ANY HINT OF FOG
TONIGHT. GIVEN THOSE SIGNALS...IT IS TOUGH TO GO WITH ANYTHING MORE
THAN PATCHY FOG AT THIS POINT.
IF ANY FOG/STRATUS DEVELOPS TONIGHT IT WILL DEPART SHORTLY AFTER
SUNRISE ON WEDNESDAY MORNING SINCE IT WILL SFC BASED/SHALLOW. WITH
MAINLY SUNNY SKIES FOR THE AFTN HIGH TEMPS SHOULD RISE WELL INTO
THE 70S MOST AREAS WITH EVEN SOME LOWER 80S POSSIBLE TOWARD THE
WISCONSIN BORDER. DAYTIME MIXING WILL RESULT IN LESS HUMID
CONDITIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
AREA WILL BE BETWEEN TWO UPPER TROUGHS ON WED NIGHT...ONE OVER
QUEBEC AND THE OTHER OVER THE PAC NW. THIS WILL LEAD TO A RIDGE
OVER THE NRN PLAINS AND CANADIAN PRAIRIES THAT WILL TRY TO PUSH
EAST TOWARDS THE CWA...BUT WILL BE HELD OFF REINFORCING NRN STREAM
WAVES ATTEMPTING TO KEEP THE UPPER TORUGH OVER QUEBEC. THIS WILL
PUT THE CWA ON THE EDGE OF THE WARM TEMPS THIS WEEKEND...UNTIL THE
UPPER RIDGE FINALLY MOVES OVERHEAD DURING THE BEGINNING OF NEXT
WEEK.
CANADIAN HIGH PRESSURE RIDGE WILL BE OVER UPPER MI ON WED NIGHT AND
THEN GRADUALLY SHIFT SOUTHEAST THROUGH THE REST OF THE WORK WEEK AS
THE TROUGH OVER QUEBEC MOVES INTO THE NEW ENGLAND STATES. MODELS
CONSISTENT ON A SHORTWAVE SLIDING THROUGH THE FLOW ON WED NIGHT INTO
THURS...BUT VARY CONSIDERABLY ON THE LOCATION/INTENSITY. ECMWF IS
THE FARTHEST N AND STRONGEST WITH THE LLVL WAA OVER NRN WI...WHILE
THE REST OF THE MODELS ARE MUCH WEAKER WITH THE WAA AND FARTHER SW.
DRY AIR DOES TRY TO BREAK DOWN THE MOISTURE IN THE MID LVLS OVER THE
SW HALF OF THE CWA WED NIGHT INTO THURS MORNING...BEFORE DIMINISHING
IN THE AFTN. LLVL DRY AIR WILL LIKELY KEEP IT MID CLOUDS AND WITH
THE BEST FORCING LIKELY STAYING TO THE S...WANTED TO KEEP POPS
IN NRN WI. BUT WITH 12Z ECMWF CONTINUING TO SHOW PCPN MAKING IT
INTO UPPER MI...WILL CONTINUE MENTION SLIGHT CHANCES JUST OVER
THE WI BORDER.
OTHERWISE...HIGH PRESSURE RIDGE AND DRY CANADIAN AIR WILL KEEP THE
AREA MOSTLY/PARTLY CLEAR INTO FRI. TEMPS WILL BE SLIGHTLY ABOVE
NORMAL ON THURS AND THEN WARM SLIGHTLY ON FRI...AS WARM AIR ALOFT
STARTS TO WORK E AND BACK OVER THE CWA.
NRN STREAM WAVE SLIDING THROUGH CNTRL CANADA FRI NIGHT AND INTO NRN
ONTARIO WILL TRY TO PUSH A COLD FRONT TOWARDS THE AREA ON SAT INTO
SUN. IT ACTUALLY MOVES INTO NRN MN ON FRI...BUT STALLS AS IT
RUNS INTO THE SFC HIGH OVER UPPER MI. WITH IT BEING A GOOD WAYS AWAY
FROM IT/S SOURCE...AND LIMITED CONVERGENCE...EXPECT PCPN TO BE
SCATTERED ALONG THE FRONT. THUS...WILL CONTINUE TO MENTION SLIGHT
AND LOW CHANCE POPS FRI NIGHT INTO SUN. FRONT FINALLY SLIDES S OF
THE AREA ON SUN NIGHT AND WILL END PCPN CHANCE AT THAT POINT.
UPPER RIDGE THEN REALLY BUILDS IN MON/TUES AS ANOTHER CANADIAN HIGH
PRESSURE RIDGE SLIDES INTO THE AREA. THERE ARE A FEW
WEAK SHORTWAVES TRYING TO ROUND THE RIDGE...BUT WITH LITTLE
TO NO INSTABILITY...WILL KEEP THE FORECAST DRY FOR MON AND
MON NIGHT. ANOTHER COLD FRONT WILL LIKELY APPROACH THE UPPER GREAT
LAKES LATE TUES AFTN AND INTO WED...SO HAVE BROUGHT IN CHANCES
OVER THE WEST. HIGHS ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGH
THE PERIOD...IN THE 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 156 PM EDT TUE JUL 17 2012
CIGS LIFTING LAST FEW HOURS AND EXPECT SLOW IMPROVEMENT THROUGH REST
OF AFTN. AREA OF LGT SHRA IMPACTS KIWD VERY EARLY THIS AFTN WITH SCT
SHRA IMPACTING KSAW THROUGH LATE AFTN. GENERALLY EXPECT SHRA TO MISS
KCMX TO SOUTH. BECOMING CONCERNED MAY SEE FOG WITH LOW VSBY/CIGS
TONIGHT WITH ADDED MOISTURE FM SHOWERS TODAY AND AS NIGHTTIME COOLING
OCCURS SETTING UP SFC BASED INVERSION. BEST CHANCE FOR FOG WILL BE AT
KSAW WITH IDEAL UPSLOPE LOW-LEVELS WIND FCST. THINKING THERE
CERTAINLY IS POTENTIAL FOR CONDITIONS TO FALL BLO ALTERNATE MINS
OVERNIGHT TONIGHT. TAF ONLY SHOWS MVFR RIGHT NOW...BUT MAY NEED TO
UPDATE THIS LATER THIS AFTN. ELSEWHERE...LIGHTER FOG IS POSSIBLE AS
WINDS ARE NOT AS FAVORABLE FOR UPSLOPE. IF WINDS BECOME LIGHT ENOUGH
THOUGH...COULD SEE PATCHY DENSE FOG AT KIWD AND KCMX AS WELL. VFR
CONDITIONS EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH ON WEDNESDAY
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 343 PM EDT TUE JUL 17 2012
HIGH PRES BUILDING S TOWARD THE UPPER LAKES WILL ARRIVE IN FULL
FORCE LATE TONIGHT INTO WEDNESDAY. THE HIGH WILL REMAIN OVERHEAD
THROUGH THE UPCOMING WEEKEND...SO WINDS WILL BE ON THE LIGHT SIDE...
MAINLY LESS THAN 15 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
157 PM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 1212 PM EDT TUE JUL 17 2012
FOG/DRIZZLE IS ALL BUT GONE AS DRIER AIR IS TRYING TO WORK IN FM
NORTH. PRETTY CLEAR OVR MUCH OF NORTHERN AND EASTERN LK SUPERIOR AS
OF NOON. MAIN ISSUE WITH THE FCST IS WHAT TO DO WITH COMPLEX OF SHRA
AND ISOLD TSRA PUSHING ACROSS NORTHWEST WISCONSIN. MAJORITY OF
MODELS HAVE REALLY MISSED THIS AREA OF SHRA. RUC AND SREF DO HAVE
SOME CLUE WITH IT AND INDICATE WEST AND SOUTHWEST CWA BEING
IMPACTED MOST THROUGH THE AFTN...WHICH MATCHES CURRENT RADAR TRENDS
WELL. STARTED TO SEE SIGNS OF MOST TSRA STAYING SOUTH OF WI
BORDER...SO WILL CONTINUE TO CUT BACK ON THOSE CHANCES. LOW CLOUDS
MAY HANG AROUND THROUGH GOOD PART OF AFTN WHERE NORTH/NORTHEAST
WINDS ACROSS LK SUPERIOR IS RESULTING IN UPSLOPE LIFTING. FAR WEST
AND NORTH CNTRL APPEAR MOST PRONE TO LINGERING LOW CLOUDS. DUE TO THE
PERSISTENT ONSHORE FLOW AND CLOUDS...TWEAKED TEMPS DOWN SOME IN THE
NORTH. MOST AREAS WILL END UP IN THE 70S FOR THE AFTN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 156 PM EDT TUE JUL 17 2012
CIGS LIFTING LAST FEW HOURS AND EXPECT SLOW IMPROVEMENT THROUGH REST
OF AFTN. AREA OF LGT SHRA IMPACTS KIWD VERY EARLY THIS AFTN WITH SCT
SHRA IMPACTING KSAW THROUGH LATE AFTN. GENERALLY EXPECT SHRA TO MISS
KCMX TO SOUTH. BECOMING CONCERNED MAY SEE FOG WITH LOW VSBY/CIGS
TONIGHT WITH ADDED MOISTURE FM SHOWERS TODAY AND AS NIGHTTIME COOLING
OCCURS SETTING UP SFC BASED INVERSION. BEST CHANCE FOR FOG WILL BE AT
KSAW WITH IDEAL UPSLOPE LOW-LEVELS WIND FCST. THINKING THERE
CERTAINLY IS POTENTIAL FOR CONDITIONS TO FALL BLO ALTERNATE MINS
OVERNIGHT TONIGHT. TAF ONLY SHOWS MVFR RIGHT NOW...BUT MAY NEED TO
UPDATE THIS LATER THIS AFTN. ELSEWHERE...LIGHTER FOG IS POSSIBLE AS
WINDS ARE NOT AS FAVORABLE FOR UPSLOPE. IF WINDS BECOME LIGHT ENOUGH
THOUGH...COULD SEE PATCHY DENSE FOG AT KIWD AND KCMX AS WELL. VFR
CONDITIONS EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH ON WEDNESDAY
MORNING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1213 PM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 1212 PM EDT TUE JUL 17 2012
FOG/DRIZZLE IS ALL BUT GONE AS DRIER AIR IS TRYING TO WORK IN FM
NORTH. PRETTY CLEAR OVR MUCH OF NORTHERN AND EASTERN LK SUPERIOR AS
OF NOON. MAIN ISSUE WITH THE FCST IS WHAT TO DO WITH COMPLEX OF SHRA
AND ISOLD TSRA PUSHING ACROSS NORTHWEST WISCONSIN. MAJORITY OF
MODELS HAVE REALLY MISSED THIS AREA OF SHRA. RUC AND SREF DO HAVE
SOME CLUE WITH IT AND INDICATE WEST AND SOUTHWEST CWA BEING
IMPACTED MOST THROUGH THE AFTN...WHICH MATCHES CURRENT RADAR TRENDS
WELL. STARTED TO SEE SIGNS OF MOST TSRA STAYING SOUTH OF WI
BORDER...SO WILL CONTINUE TO CUT BACK ON THOSE CHANCES. LOW CLOUDS
MAY HANG AROUND THROUGH GOOD PART OF AFTN WHERE NORTH/NORTHEAST
WINDS ACROSS LK SUPERIOR IS RESULTING IN UPSLOPE LIFTING. FAR WEST
AND NORTH CNTRL APPEAR MOST PRONE TO LINGERING LOW CLOUDS. DUE TO THE
PERSISTENT ONSHORE FLOW AND CLOUDS...TWEAKED TEMPS DOWN SOME IN THE
NORTH. MOST AREAS WILL END UP IN THE 70S FOR THE AFTN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
853 AM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 852 AM EDT TUE JUL 17 2012
ADDED DRIZZLE TO NORTH CENTRAL UPR MICHIGAN...ROUGHLY NEGAUNEE TO
MUNISING WITH MOIST NORTHERLY FLOW. MAINLY A HIGHER TERRAIN ISSUE.
OTHERWISE...KEPT TSRA MENTION FOR TODAY RESTRICTED TO VCNTY OF WI
BORDER AS COMPLEX OF SHRA/TSRA NEAR KDLH IS EXPECTED TO PROPEL ESE
THROUGH THE EARLY AFTN. FINALLY...BASED ON SFC OBS AND WEB CAMS
TRIMMED FOG OUT OF MOST CWA EXCEPT NORTH CENTRAL DUE TO THE SLIGHTLY
CONVERGENT NORTHERLY FLOW OFF LK SUPERIOR. NO OTHER CHANGES NEEDED
AT THIS POINT.
COOLER TEMPERATURES ARE LIKELY MOST NOTABLE WEATHER EVERYONE WILL
KEY IN ON TODAY. CURRENT FCST HAS FINE HANDLE ON TEMP TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
736 AM EDT TUE JUL 17 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT TUE JUL 17 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE JUL 17 2012
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA OVERNIGHT. SINCE FOG HAS
BEEN PRESENT OVER LAKE SUPERIOR...WIND SHIFT TO THE N SHOULD BRING
IFR/POTENTIAL LIFR CONDITIONS TO ALL SITES AFTER FROPA OVERNIGHT. LOW
CONFIDENCE IN SHRA/TSRA ACCOMPANYING FRONT WITH MOST OF THE PCPN
REMAINING TO THE NORTH AND EAST. EXPECT DRIER AIR MOVING IN WITH ACYC
NRLY FLOW TO BRING IMPROVING CONDITIONS BY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED FOR 00Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
545 PM CDT WED JUL 18 2012
.DISCUSSION...ISSUED 307 PM CDT
OVERALL THE LARGE SCALE PATTERN WILL CHANGE LITTLE FOR US OVER
THROUGH THE FORECAST PERIOD... WITH THE BROAD UPPER RIDGE
CONTINUING TO REIGN OVER THE CENTER OF THE CONTINENT. WE WILL
CONTINUE TO SEE ABOVE NORMAL TEMPERATURES AS A RESULT... WITH
CHANCES FOR PCPN AND SLIGHT COOL DOWNS TIED TO SHORTWAVES MOVING
THEIR WAY AROUND THE PERIPHERY OF THE UPPER RIDGE. THE GFS AND
ECMWF ARE IN REMARKABLY GOOD AGREEMENT THROUGH EARLY NEXT WEEK...
SO ALTHOUGH THEY MAY BE WRONG IT IS TOUGH TO DEVIATE TOO FAR FROM
WHAT THEY ARE SHOWING WITH RESPECT TO THE BIG PICTURE. WILL STICK
CLOSER TO THE ECMWF FOR SOME OF THE DETAILS... MAINLY DUE TO THE
LOW LEVEL COOL/WET BIASES IN THE GFS AND WHAT APPEARS TO BE AN
ASSOCIATED WET BIAS. IN THE SHORTER TERM... UTILIZED THE NAM AND
SREF FOR POP/WEATHER CHANCES AND A CONSENSUS APPROACH FOR
TEMPERATURES... BLENDING WITH POTENTIAL MIX-DOWN VALUES FOR HIGHS.
AN ELONGATED SHORTWAVE TROUGH CURRENTLY APPARENT ON WATER VAPOR
IMAGERY AND RAP UPPER LEVEL PV ANALYSES EXTENDS FROM SOUTHERN
MANITOBA INTO EASTERN NEBRASKA. A LOWER LEVEL MCV FEATURE CAN ALSO
BE SEEN MOVING EAST INTO SOUTH CENTRAL MINNESOTA. THE LATTER
FEATURE IS WORKING TO SUPPORT THE CONVECTIVE ACTIVITY CURRENTLY
OVER THE SOUTHERN PART OF THE AREA... WITH AN OUTFLOW BOUNDARY
FROM THIS MORNING/S CONVECTION ASSISTING WITH THINGS OVER
SOUTHEAST MINNESOTA. THE LARGER SCALE FRONT/BAROCLINIC ZONE IS
NEAR THE MINNESOTA/IOWA BORDER... AND SHOULD HELP TO FURTHER FOCUS
ACTIVITY AS WE HEAD INTO THE EVENING AND THE AFOREMENTIONED LARGE
SCALE SHORTWAVE TROUGH WORKS THROUGH THE AREA. MLCAPE VALUES AOA
2000 J/KG ARE PRESENT ACROSS MOST OF THE AREA... SO THERE IS NO
SHORTAGE OF INSTABILITY. WITH SOME FORCING WORKING ACROSS THE AREA
THROUGH THE EVENING HOURS... THINK WE SHOULD CONTINUE TO SEE SOME
SHRA/TSRA UNTIL WE SEE MORE SUBSTANTIAL MID-LEVEL DRYING AND
SUBSIDENCE LATER TONIGHT. ISOLATED SEVERE STORMS ARE STILL
POSSIBLE GIVEN THE DEGREE OF INSTABILITY... BUT WITH THE DEEP
LAYER SHEAR GENERALLY AOB 30 KT... THE POTENTIAL FOR WIDESPREAD
SEVERE WEATHER APPEARS TO BE LIMITED GIVEN LACK OF EXPECTED
ORGANIZATION WITH MOST STORMS. HOWEVER... A FEW STORMS COULD TAKE
ADVANTAGE OF LOCALLY ENHANCED SHEAR OWING TO THEIR STORM MOTION...
SUCH AS SOME OF THE ACTIVITY CURRENTLY OVER SOUTHEAST MINNESOTA...
AND THOSE WOULD BE THE STORMS MOST LIKELY TO GENERATE SEVERE WEATHER.
SURFACE RIDGING AND MID-LEVEL DRYING/SUBSIDENCE WILL BUILD EAST
ACROSS THE CWFA OVERNIGHT... BRINGING ANY LINGERING SHRA/TSRA TO
AN END. THE NEXT CHANCE FOR PCPN THEN LOOKS TO HOLD OFF UNTIL
FRIDAY NIGHT AND SATURDAY AS THE BAROCLINIC ZONE LIFTS BACK NORTH
ACROSS THE AREA. AT THIS POINT... THE BEST CHANCE LOOKS LIKE IT
WILL BE NORTH OF OUR CWFA CLOSER TO THE WARM FRONTAL BOUNDARY...
BUT THERE IS SUFFICIENT UNCERTAINTY IN THE BOUNDARY PLACEMENT TO
INCLUDE A CHANCE FOR SHRA/TSRA OVER THE NORTHERN HALF OR SO OF THE
AREA. THESE CHANCES WILL THEN SAG SOUTH AND EAST SATURDAY NIGHT
INTO SUNDAY AS A WAVE TRAVELS EAST ALONG THE NEARLY STATIONARY WARM
FRONTAL BOUNDARY. WILL INCLUDE SOME CHANCES FOR PCPN FROM MONDAY
NIGHT INTO WEDNESDAY AS WELL... AFTER DRYING THINGS OUT LATE
SUNDAY AND SUNDAY NIGHT... WITH THE ECMWF AND GFS BOTH SUGGESTING
WE WILL BE NEAR THE BAROCLINIC ZONE/RING OF FIRE AROUND THE
PERIPHERY OF THE UPPER RIDGE AS A FEW SHORTWAVES DROP EAST-
SOUTHEAST FROM WESTERN AND CENTRAL CANADA.
&&
.AVIATION.../00Z TAF ISSUANCE/
WHAT SHUD BE THE LAST OF THE EVENING CONVECTION HAS DEVELOPED INTO A
NARROW LINE NEAR THE MN/WI BORDER. NICE SFC PRES FALL CENTER AHD OF
THIS LINE SHUD HELP TO MAINTAIN IT AS IT MOVES EAST. ONLY TAF WHICH
SHUD BE AFFECTED WILL BE EAU AS STORMS SHUD BE EAST OF RNH BY ISSUE
TIME. CONVECTION EARLIER TODAY ALONG WITH CURRENT PCPN HAS LEFT
LOWER LEVELS MOIST WITH CONSIDERABLE MVFR CIGS. EXPECT DURING THE
OVERNITE WITH LIGHT WINDS THAT LOWER CIGS WILL EXPAND ACROSS MUCH OF
AREA.
KMSP...THUNDER THREAT HAS MOVED EAST OF MSP. OUTFLOW FROM PCPN HAS
LEFT MSP WITH A LIGHT S WIND...BUT TREND IN NEXT 1-2 HOURS WILL BE
FOR GRADIENT TO AGAIN DEVELOP AN ENE WIND. AREAS MVFR CIGS FROM
TSTMS WILL PRBLY REMAIN IN AREA FOR A COUPLE HRS...THEN IMPROVE TO
VFR BEFORE MORE WDSPRD MVFR CIGS DEVELOP AGAIN AFT 06Z.
OUTLOOK...
THU NIGHT/FRI...VFR.
SAT...VFR BUT INCREASING HIGH CLOUDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1100 PM MDT MON JUL 16 2012
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS MOST OF THE COUNTY
WARNING AREA. THE UPPER LOW ALONG THE CALIFORNIA/OREGON COAST IS
WELL DEPICTED BY SATELLITE IMAGERY AND CONTINUES TO SEND MOISTURE
AND SHORT WAVE ENERGY ACROSS SOUTHWEST MONTANA...INTO NORTH CENTRAL
MONTANA. SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED ARE GENERALLY
ISOLATED IN NATURE AND ARE MAINLY PRODUCING BRIEF HEAVY RAIN DUE TO
CONTINUED HIGH PRECIPITABLE WATER VALUES. HAVE DROPPED POPS BACK
INTO THE SCATTERED CATEGORY. HRRR ANALYSIS CONTINUES TO SHOW
CONVECTIVE ACTIVITY CONTINUING THROUGH THE EVENING BEFORE
DIMINISHING AFTER 09Z. TEMPERATURE FORECASTS LOOK ON TRACK. EMANUEL
&&
.AVIATION...
UPDATED 0500Z.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DIMINISH OVER THE
REGION...WITH MOST ACTIVITY DIMINISHING AFTER 09Z...HOWEVER MORE
STORMS WILL REDEVELOP AFTER 14Z IN NORTH CENTRAL MONTANA...AND AFTER
19Z IN SOUTHWEST MONTANA. SOME STORMS COULD PRODUCE BRIEF HEAVY
RAIN. BRUSDA
&&
.PREV DISCUSSION...ISSUED 251 PM MDT MON JUL 16 2012
TONIGHT THROUGH WEDNESDAY...A WEATHER DISTURBANCE ALOFT OVER
SOUTHERN IDAHO MONDAY AFTERNOON WILL BE MOVING NORTH TONIGHT. IT
WILL MOVE INTO SOUTHWEST MONTANA THIS EVENING AND REACH CENTRAL
MONTANA LATE TONIGHT. MONSOONAL MOISTURE IS ASSOCIATED WITH THE
DISTURBANCE ALONG WITH INSTABILITY. WILL GO WITH SCATTERED SHOWERS
AND THUNDERSTORMS FOR MOST LOWER ELEVATIONS WITH MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS OVER SOUTHWEST AND
CENTRAL MONTANA. THE PLAINS OF NORTHERN MOUNTAIN WILL CONTINUE
RELATIVELY DRIER UNTIL THURSDAY WHEN THE DISTURBANCE REACHES THAT
AREA. EVEN THOUGH SOUTHWEST AND MOST OF CENTRAL MONTANA WILL BE
SOUTH OF THE DISTURBANCE TUESDAY AFTERNOON AND SOMEWHAT
DRIER..THERE WILL AGAIN BE INSTABILITY OVER THAT AREA SO WILL
CONTINUE THE IDEA OF A CHANCE OF SHOWERS AND THUNDERSTORMS. AS THE
DISTURBANCE MOVES INTO CANADA BY TUESDAY EVENING A DRIER AIRMASS
WILL SPREAD OVER THE FORECAST AREA RESULTING IN MOSTLY CLEAR SKIES
WITH LITTLE IF ANY THREAT OF PRECIPITATION. STILL SEE A WARMING
TREND TUESDAY AND WEDNESDAY AND ESPECIALLY WEDNESDAY WITH HIGHS
THAT DAY EXPECTED TO BE SOME 5 TO 10 DEGREES WARMER THAN THOSE OF
TUESDAY. BLANK
WEDNESDAY NIGHT THROUGH MONDAY NIGHT...A LOW PRESSURE TROF WILL
BE OVER THE PACIFIC NORTHWEST WEDNESDAY NIGHT WITH
UNSETTLED...SOUTHWEST FLOW ALOFT OVER THE ZONES. A SHORTWAVE WILL
MOVE THROUGH THIS FLOW ALOFT THURSDAY. THE AIRMASS SHOULD BE VERY
DRY ACROSS THE SOUTHWEST ZONES AND MOST INSTABILITY AND CONVECTION
IS EXPECTED TO THE NORTH. THE TROF WILL REMAIN OVER THE PACIFIC
NORTHWEST FRIDAY ALTHOUGH THE AIRMASS WILL BE QUITE DRY AND THE
CHANCE OF AFTERNOON CONVECTION WILL BE SLIGHT. THE UPPER LEVEL
TROF WILL FINALLY MOVE EAST SATURDAY BUT THE LOW WILL BE QUITE FAR
NORTH...CROSSING THROUGH ALBERTA. CENTRAL MONTANA WILL REMAIN
QUITE DRY. HIGH PRESSURE AND CONTINUED VERY WARM TEMPERATURES WILL
CONTINUE THROUGH MONDAY. AT THIS TIME...A RETURN OF MONSOONAL
MOISTURE IS POSSIBLE ACROSS THE SOUTHWEST ZONES MONDAY AND THE
POSSIBILITY OF AFTERNOON CONVECTION WILL INCREASE. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 83 60 94 / 30 40 20 10
CTB 53 75 55 90 / 30 50 30 10
HLN 58 87 58 93 / 60 40 20 10
BZN 51 88 50 93 / 50 30 20 10
WEY 42 75 40 80 / 40 30 10 10
DLN 51 81 51 88 / 40 30 20 10
HVR 57 84 59 95 / 20 50 30 10
LWT 55 83 56 90 / 50 50 30 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL/BLANK
LONG TERM...ZELZER
AVIATION...BRUSDA
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1011 PM CDT WED JUL 18 2012
.UPDATE...CONTINUED A SLIGHT CHANCE OF THUNDERSTORMS THROUGH LATE
THIS EVENING...MAINLY ALONG AND NORTHWEST OF A LINE FROM LEXINGTON
TO SPALDING NEBRASKA BASED ON CURRENT RADAR AND SATELLITE TRENDS.
&&
.PREV DISCUSSION... /ISSUED 619 PM CDT WED JUL 18 2012/
AVIATION...00Z KGRI TAF...EXPECT SOME SHOWERS AND THUNDERSTORMS
TO CONTINUE TO PUSH EASTWARD AND APPROACH THE TERMINAL OVER THE
NEXT COUPLE OF HOURS...POSSIBLY IMPACTING THE TERMINAL AT TIMES
BETWEEN 19/00Z-19/03Z. SO FAR THESE STORMS HAVE BEEN SPOTTY...BUT
PER LATEST GUIDANCE COULD SEE THEM CONTINUE TO INTENSIFY AND
SPREAD IN COVERAGE AS THEY WORK EAST BEFORE SUNSET. LOWERED CIGS
IN AREAS OF SHRAS TO 5KFT...KEEPING CONDITIONS VFR...BUT CERTAINLY
COULD SEE CIGS BELOW THIS IF A HEAVIER SHOWER IMPACTS KGRI.
OTHERWISE...WINDS ARE EXPECTED TO BE LIGHT OVERNIGHT ONCE THE SHRA
AND TSRA ACTIVITY DIMINISHES...BECOMING E TO SE AT LESS THAN 10KTS
DURING THE DAY THURSDAY. AFTER TONIGHTS ACTIVITY...VFR CONDITIONS
ARE EXPECTED THROUGH REMAINDER OF PERIOD.
PREV DISCUSSION... /ISSUED 407 PM CDT WED JUL 18 2012/
SHORT TERM...TODAY THROUGH THURSDAY. WILL KEEP THE VERY SLIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH EARLY
EVENING. THIS IS ONLY A 20 PERCENT CHANCE OF PRECIPITATION. VERY HOT
WEATHER WILL CONTINUE THROUGHOUT THE PERIOD.
VISIBLE SATELLITE IMAGERY DEPICTS AN EXPANDING CU FIELD WITH
DEVELOPING THUNDERSTORMS ACROSS WESTERN NEBRASKA. MOST OF THESE
STORMS WILL DIE PRIOR TO MAKING IT INTO OR CWA. HOWEVER...THERE IS A
SLIGHT CHANCE THAT A FEW OF THESE THUNDERSTORMS MIGHT MAKE IT AS
FAR EAST AS OUR FAR WESTERN ZONES BEFORE DIEING OUT. IT IS HARD TO
PICK OUT BOUNDARIES ON THE SFC MAP WITH THE SFC WINDS BEING VERY
LIGHT AND VARIABLE ACROSS MOST OF OUR CWA. THERE IS A SLIGHTLY
MORE DEFINED SFC BOUNDARY OVER NORTH CENTRAL KANSAS WITH SOUTH
SOUTHWEST WINDS SOUTH OF THE FRONT AND NORTHEAST WINDS NORTH OF
THE FRONT. THE HRRR AND 4KM WRF CONTINUE TO HINT AT THE
POSSIBILITY OF A FEW ISOLATED THUNDERSTORMS OVER OUR CWA EARLY
THIS AFTERNOON. WE HAVE BEEN SEEING A FEW OFF AND ON SHOWERS
ACROSS THE AREA THIS AFTERNOON AND BELIEVE THIS COULD CONTINUE
UNTIL WE LOSE DIURNAL HEATING LATER THIS EVENING.
THE UPPER RIDGE WILL CONTINUE TO BUILD ON THURSDAY AND THIS SHOULD
SHUT DOWN ALL PRECIPITATION CHANCES FOR AWHILE. THEREFORE...EXPECT
DRY CONDITIONS ON THURSDAY AND IT WILL CONTINUE TO BE VERY HOT.
HEAT INDEX VALUES ARE NOT HIGH ENOUGH YET TO PUT NORTHERN ZONES IN
THE HEAT ADVISORY...BUT SOUTHERN ZONES SHOULD ONCE AGAIN SEE
TEMPERATURES/HEAT INDEX VALUES OF 100 TO 105 DEGREES.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE HOT TEMPERATURES AND A CHANCE FOR SOME
THUNDERSTORMS ON WEDNESDAY.
THE UPPER LEVEL RIDGE THAT HAS BEEN THE MAINSTAY ACROSS THE PLAINS
FOR SEVERAL DAYS WILL CONTINUE TO PLAGUE THE FORECAST AREA THROUGH
TUESDAY. TEMPERATURES WILL TOP OUT AROUND 10 DEGREES ABOVE NORMAL.
IN ADDITION TO THE HEAT THE HUMIDITY WILL ALSO CAUSE HEAT INDEX
VALUES TO RISE TO 100 TO 105 FOR NORTH CENTRAL KANSAS AND FAR
SOUTHERN NEBRASKA FOR SATURDAY INTO SUNDAY. THE HEAT CONTINUES
ACROSS THE ENTIRE AREA FOR MONDAY AND TUESDAY...WITH HIGH
TEMPERATURES ACROSS THE AREA EXPECTED TO BE AT OR ABOVE 100 DEGREES.
THERE IS A POTENTIAL FOR A BREAK IN THE HEAT MID WEEK NEXT WEEK. THE
UPPER LEVEL RIDGE FINALLY BREAKS DOWN AS AN UPPER LEVEL WAVE MOVES
THROUGH THE NORTHERN PLAINS. MODELS STILL HAVE SOME DIFFERENCES IN
TIMING AND LOCATION OF THE UPPER WAVE AND THE SURFACE FRONT THAT IS
EXPECTED TO MOVE THROUGH THE AREA. THE GFS IS A LITTLE SLOWER WITH
THE SURFACE FRONT AND A LITTLE FURTHER SOUTH WITH THE UPPER WAVE
THAN THE ECMWF. WILL GO MORE WITH THE SLOWER SOLUTION SINCE THAT IS
TYPICAL OF THE MODELS TO MOVE THINGS THROUGH TOO QUICKLY. WILL HAVE
A CHANCE FOR SOME THUNDERSTORMS IN THE WEST FOR WEDNESDAY AND
TEMPERATURES SHOULD BE A BIT COOLER WITH READINGS ONLY IN THE 90S.
AVIATION...18Z KGRI TAF. A WEAK SFC FRONTAL BOUNDARY HAS STALLED
ACROSS SOUTH CENTRAL NEBRASKA...AND THE BOUNDARY MAY TRIGGER A FEW
SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON. HOWEVER...THIS
ACTIVITY IS EXPECTED TO BE ISOLATED AND HAS NOT BEEN INCLUDED FOR
THE TERMINAL DUE TO THE LIMITED COVERAGE. WITH THE MEANDERING
BOUNDARY RIGHT OVERHEAD...WINDS WILL BE LIGHT AND VARIABLE THROUGH
TONIGHT. THE WIND WILL BECOME MORE EASTERLY TOMORROW. CLEAR TO
SCATTERED CLOUD COVER IS EXPECTED WITH A CONTINUATION OF VFR
CONDITIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR NEZ082>087.
KS...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KSZ005>007-017>019.
&&
$$
UPDATE...GUERRERO
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
619 PM CDT WED JUL 18 2012
.AVIATION...00Z KGRI TAF...EXPECT SOME SHOWERS AND THUNDERSTORMS
TO CONTINUE TO PUSH EASTWARD AND APPROACH THE TERMINAL OVER THE
NEXT COUPLE OF HOURS...POSSIBLY IMPACTING THE TERMINAL AT TIMES
BETWEEN 19/00Z-19/03Z. SO FAR THESE STORMS HAVE BEEN SPOTTY...BUT
PER LATEST GUIDANCE COULD SEE THEM CONTINUE TO INTENSIFY AND
SPREAD IN COVERAGE AS THEY WORK EAST BEFORE SUNSET. LOWERED CIGS
IN AREAS OF SHRAS TO 5KFT...KEEPING CONDITIONS VFR...BUT CERTAINLY
COULD SEE CIGS BELOW THIS IF A HEAVIER SHOWER IMPACTS KGRI.
OTHERWISE...WINDS ARE EXPECTED TO BE LIGHT OVERNIGHT ONCE THE SHRA
AND TSRA ACTIVITY DIMINISHES...BECOMING E TO SE AT LESS THAN 10KTS
DURING THE DAY THURSDAY. AFTER TONIGHTS ACTIVITY...VFR CONDITIONS
ARE EXPECTED THROUGH REMAINDER OF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 407 PM CDT WED JUL 18 2012/
SHORT TERM...TODAY THROUGH THURSDAY. WILL KEEP THE VERY SLIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH EARLY
EVENING. THIS IS ONLY A 20 PERCENT CHANCE OF PRECIPITATION. VERY HOT
WEATHER WILL CONTINUE THROUGHOUT THE PERIOD.
VISIBLE SATELLITE IMAGERY DEPICTS AN EXPANDING CU FIELD WITH
DEVELOPING THUNDERSTORMS ACROSS WESTERN NEBRASKA. MOST OF THESE
STORMS WILL DIE PRIOR TO MAKING IT INTO OR CWA. HOWEVER...THERE IS A
SLIGHT CHANCE THAT A FEW OF THESE THUNDERSTORMS MIGHT MAKE IT AS
FAR EAST AS OUR FAR WESTERN ZONES BEFORE DIEING OUT. IT IS HARD TO
PICK OUT BOUNDARIES ON THE SFC MAP WITH THE SFC WINDS BEING VERY
LIGHT AND VARIABLE ACROSS MOST OF OUR CWA. THERE IS A SLIGHTLY
MORE DEFINED SFC BOUNDARY OVER NORTH CENTRAL KANSAS WITH SOUTH
SOUTHWEST WINDS SOUTH OF THE FRONT AND NORTHEAST WINDS NORTH OF
THE FRONT. THE HRRR AND 4KM WRF CONTINUE TO HINT AT THE
POSSIBILITY OF A FEW ISOLATED THUNDERSTORMS OVER OUR CWA EARLY
THIS AFTERNOON. WE HAVE BEEN SEEING A FEW OFF AND ON SHOWERS
ACROSS THE AREA THIS AFTERNOON AND BELIEVE THIS COULD CONTINUE
UNTIL WE LOSE DIURNAL HEATING LATER THIS EVENING.
THE UPPER RIDGE WILL CONTINUE TO BUILD ON THURSDAY AND THIS SHOULD
SHUT DOWN ALL PRECIPITATION CHANCES FOR AWHILE. THEREFORE...EXPECT
DRY CONDITIONS ON THURSDAY AND IT WILL CONTINUE TO BE VERY HOT.
HEAT INDEX VALUES ARE NOT HIGH ENOUGH YET TO PUT NORTHERN ZONES IN
THE HEAT ADVISORY...BUT SOUTHERN ZONES SHOULD ONCE AGAIN SEE
TEMPERATURES/HEAT INDEX VALUES OF 100 TO 105 DEGREES.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE HOT TEMPERATURES AND A CHANCE FOR SOME
THUNDERSTORMS ON WEDNESDAY.
THE UPPER LEVEL RIDGE THAT HAS BEEN THE MAINSTAY ACROSS THE PLAINS
FOR SEVERAL DAYS WILL CONTINUE TO PLAGUE THE FORECAST AREA THROUGH
TUESDAY. TEMPERATURES WILL TOP OUT AROUND 10 DEGREES ABOVE NORMAL.
IN ADDITION TO THE HEAT THE HUMIDITY WILL ALSO CAUSE HEAT INDEX
VALUES TO RISE TO 100 TO 105 FOR NORTH CENTRAL KANSAS AND FAR
SOUTHERN NEBRASKA FOR SATURDAY INTO SUNDAY. THE HEAT CONTINUES
ACROSS THE ENTIRE AREA FOR MONDAY AND TUESDAY...WITH HIGH
TEMPERATURES ACROSS THE AREA EXPECTED TO BE AT OR ABOVE 100 DEGREES.
THERE IS A POTENTIAL FOR A BREAK IN THE HEAT MID WEEK NEXT WEEK. THE
UPPER LEVEL RIDGE FINALLY BREAKS DOWN AS AN UPPER LEVEL WAVE MOVES
THROUGH THE NORTHERN PLAINS. MODELS STILL HAVE SOME DIFFERENCES IN
TIMING AND LOCATION OF THE UPPER WAVE AND THE SURFACE FRONT THAT IS
EXPECTED TO MOVE THROUGH THE AREA. THE GFS IS A LITTLE SLOWER WITH
THE SURFACE FRONT AND A LITTLE FURTHER SOUTH WITH THE UPPER WAVE
THAN THE ECMWF. WILL GO MORE WITH THE SLOWER SOLUTION SINCE THAT IS
TYPICAL OF THE MODELS TO MOVE THINGS THROUGH TOO QUICKLY. WILL HAVE
A CHANCE FOR SOME THUNDERSTORMS IN THE WEST FOR WEDNESDAY AND
TEMPERATURES SHOULD BE A BIT COOLER WITH READINGS ONLY IN THE 90S.
AVIATION...18Z KGRI TAF. A WEAK SFC FRONTAL BOUNDARY HAS STALLED
ACROSS SOUTH CENTRAL NEBRASKA...AND THE BOUNDARY MAY TRIGGER A FEW
SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON. HOWEVER...THIS
ACTIVITY IS EXPECTED TO BE ISOLATED AND HAS NOT BEEN INCLUDED FOR
THE TERMINAL DUE TO THE LIMITED COVERAGE. WITH THE MEANDERING
BOUNDARY RIGHT OVERHEAD...WINDS WILL BE LIGHT AND VARIABLE THROUGH
TONIGHT. THE WIND WILL BECOME MORE EASTERLY TOMORROW. CLEAR TO
SCATTERED CLOUD COVER IS EXPECTED WITH A CONTINUATION OF VFR
CONDITIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR NEZ082>087.
KS...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KSZ005>007-017>019.
&&
$$
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1131 AM EDT TUE JUL 17 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER INLAND AREAS THROUGH
THURSDAY. A COLD FRONT WILL MOVE INTO THE AREA FRIDAY AND STALL
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1115 AM TUESDAY...MINOR CHANGES TO PREV FCST. SATL SHOWS SKIES
CLEAR ACROSS MOST OF THE REGION WITH SOME SHRA OFFSHORE AND TO THE
S. AXIS OF BEST PRECIP WTR IS CURRENTLY TO THE SE WITH DRIER AIR TO
THE NW. LOWERED POPS A BIT FOR INLAND AND NRN COUNTIES GIVEN THE
DRIER AIR IN THESE AREAS. ALSO LOWERED INIT SKY COVER GIVEN CLR
SKIES ACROSS THE REGION...SHLD BECOME PC LATER AS CU DEVELOP.
PREV DISC...SOME ISOLATED SHOWERS HAVE DEVELOPED EAST OF WILMINGTON
AND ARE MOVING OFFSHORE INTO OUR FAR SOUTHERN COASTAL WATERS. THESE
SHOWERS SHOULD REMAIN OFFSHORE AND EXPECT GENERALLY DRY CONDITIONS
THRU THE MORNING. UPPER AIR ANALYSIS SHOWS A WEAK EAST-WEST ORIENTED
500 MB TROUGH ACROSS EASTERN NORTH CAROLINA WITH A CLOSED UPPER LOW
OVER NORTHEASTERN FLORIDA. WHILE THE TROUGH GRADUALLY LIFTS
OUT...LEAVING EASTERN NC IN A COL AREA...THERE IS STILL SOME DECENT
MID-LEVEL VORTICITY AROUND DURING THE MID-AFTERNOON HOURS. AT THE
SURFACE A TROUGH LINGERS OVER THE PIEDMONT REGION AS HIGH PRESSURE
WELL OFFSHORE CONTINUES TO PROVIDE WARM...MOISTURE AND UNSTABLE TO
EASTERN NC. BOTH THE RAP AND GFS INDICATE THAT GIVEN MAX
TEMPERATURES INTO THE LOWER 90S AND DEWPOINTS IN THE LOWER AND
MIDDLE 70S LATER THIS AFTERNOON...CAPE VALUES IN EXCESS OF 3000 J/KG
AND LI VALUES OF -6 TO -8 ARE FORECAST. GIVEN THESE FACTORS...THINK
ANOTHER GOOD COVERAGE OF SHOWERS AND TSTMS CAN BE EXPECTED WITH THE
HIGHEST PROBABILITY IN AREAS SIMILAR TO YESTERDAY OVER THE
NORTHWESTERN CWA WITH POPS TAPERING BACK TO MINIMAL NEAR THE
SOUTHERN COASTAL AREA. WILL AGAIN HIGHLIGHT LOCALLY STRONG STORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...SHOWERS AND TSTMS WILL ONCE AGAIN DISSIPATE
WITH LOSS OF HEATING AFTER ABOUT 02Z. MINIMUM TEMPERATURES WILL
AGAIN BE BETWEEN 73 AND 78 DEGREES WITH LIKELY SOME LEFTOVER HIGH
DEBRIS CLOUDS FROM ANY CONVECTION THAT DEVELOPS DURING THE
AFTERNOON AND EVENING HOURS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 330 AM TUE...LONG TERM PERIOD WILL FEATURE THE POTENTIAL FOR
PERIODS OF WIDESPREAD HEAVY RAIN THIS WEEKEND. FOR WED AND THUR...E
NC WILL REMAIN IN TYPICAL SUMMER REGIME WITH ISO-SCT AFTERNOON
THUNDERSTORMS MAINLY ASSOCIATED WITH SEA BREEZE FRONT.
WEAKNESS IN THE MID LEVELS WILL BRING A CHANCE OF DIURNAL CONVECTION
ACROSS INLAND AREAS WED AFTERNOON. SUBTROPICAL MOISTURE WILL STREAM
NORTHEASTWARD OFF THE COAST WED NIGHT...AND WILL BRING SCT
THUNDERSTORMS FOR THE COASTAL WATERS. SOME OF THIS CONVECTION MAY
ADVECT OFF THE OCEAN AND AFFECT THE COASTAL COUNTIES LATE WED NIGHT.
FOR THUR...PIEDMONT THERMAL TROUGH WILL STRENGTHEN SOMEWHAT IN
RESPONSE TO BUILDING CENTRAL CONUS RIDGE AND DIGGING OF EASTERN
CONUS TROUGH. SOMEWHAT BETTER CHANCE FOR MORE ORGANIZED CONVECTION
WELL INLAND NEARER THE THERMAL TROUGH. BOTH GFS AND ECMWF IN FAIRLY
GOOD AGREEMENT WITH THE SYNOPTIC REGIME THROUGH THIS WEEKEND...
THOUGH SOME TIMING DIFFERENCES IN ARRIVAL OF SFC BOUNDARY THAT WILL
SET THE STAGE FOR POSSIBLE PERIODS OF HEAVY RAIN THIS WEEKEND. SIDED
WITH MORE CONSISTENT/SLOWER ECM SOLN...AS THIS HAS SUPPORT FROM ITS
ENSEMBLE MEAN...GEFS ENSEMBLE MEAN SOLN...AND OPERATIONAL 17/00Z
CANADIAN MODEL. THIS SOLN HANGS UP THE EAST-WEST ORIENTED FRONT
THROUGH THE WEEKEND...AND WITH PWATS AROUND 2.25 INCHES OR HIGHER...
COULD BRING THREAT FOR FLOODING. IF THESE PWAT VALS COME TO
FRUITION...THEY WOULD BE NEAR THE 99TH PERCENTILE FOR CLIMATOLOGICAL
VALUES FOR JULY...WHICH COULD CERTAINLY POSE THREAT FOR FLOODING
RAINS. THE UNSETTLED WEATHER MAY LINGER INTO THE BEGINNING OF NEXT
WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 00Z WEDNESDAY/...
AS OF 645 AM TUESDAY...AGAIN THIS MORNING...A LIGHT 3 TO 5 KNOT
WIND HAS PREVENTED ANY FOG FORMATION AT THE TAF SITES. WITH A
SURFACE TROUGH INLAND AND SOME WEAK UPPER ENERGY IN PLACE..SCATTERED
TSTMS WILL BE A GOOD POSSIBILITY LATER TODAY...ESPECIALLY AT KPGV
AND PERHAPS AGAIN AT KEWN/KISO.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUESDAY...MAINLY VFR CONDITIONS OTHER THAN SOME TEMPO
REDUCTION TO VSBYS/CIGS LATE AT NIGHT/EARLY IN THE MORNING DUE TO
RADIATION FOG/BR. SMALL CHANCES OF AFTERNOON THUNDERSTORMS DUE TO
SEA BREEZE FRONT PROPAGATING INLAND EACH AFTERNOON. BETTER CHANCE
FOR WIDESPREAD RAIN AND THUNDERSTORMS ARRIVES ON FRIDAY AND WILL
LINGER INTO THE WEEKEND...WITH PERIODS OF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY...
AS OF 1115 AM TUESDAY...NO CHANGES WITH SW WINDS 10 TO 20 KTS AND
SEAS 2 TO 4 FEET...HIGHEST OFFSHORE.
PREV DISC...CURRENT BUOY OBSERVATIONS INDICATING GENERALLY SW WINDS
OF 10 TO 15 KNOTS WITH A GUST TO 18 KNOTS AT DIAMOND BUOY WITH SEAS
AT 2 TO 4 FEET WITH A ROLLING 10 TO 11 SECOND SWELL. THE SAME
PATTERN THAT WE HAVE SEEN OVER THE PAST SEVERAL DAYS WILL CONTINUE.
GRADIENT BETWEEN SURFACE TROUGH OVER THE PIEDMONT REGION AND THE
SEMI-PERMANENT BERMUDA HIGH OFFSHORE WILL LEAD TO STOUTEST WINDS OF
10 TO 15 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS. SEAS WILL RUN 2 TO
4 FEET WITH OCCASIONAL 5 FOOT SEAS OVER THE OUTER
WATERS...ESPECIALLY IN THE CENTRAL WATERS.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUE...LATEST RUN OF THE MAJOR MODELS IN VERY CLOSE
AGREEMENT THROUGH LATE WEEK. STILL PREFER THE 00Z ECMWF HANDLING OF
THE SOUTHWARD MOVING COOL FRONT THIS WEEKEND...WHICH HANGS UP THE
FRONT OVER EASTERN NC THIS WEEKEND. THE GFS PUSHES THE FRONT TO THE
SOUTH WHICH IS HARD TO DO THIS TIME OF YEAR. SOUTHWEST FLOW
CONTINUES THROUGH FRIDAY. EXPECTING A NORTHEAST FLOW OVER THE
CENTRAL AND NORTHERN WATERS SATURDAY AND SUNDAY NORTH OF THE FRONT
WITH A SOUTHWEST FLOW OVER THE SOUTHERN WATERS. STILL LOOKING AT
SMALL CRAFT SEAS DEVELOPING OVER THE CENTRAL AND SOUTHERN WATERS
LATE WED NIGHT THROUGH FRIDAY NIGHT AHEAD OF THE FRONT. WINDS AND
SEAS SHOULD FALL BELOW SCA THIS WEEKEND WITH FRONT OVERHEAD.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...RF/CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...RF/CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
347 AM EDT TUE JUL 17 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER INLAND AREAS THROUGH
THURSDAY. A COLD FRONT WILL MOVE INTO THE AREA FRIDAY AND STALL
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 335 AM TUESDAY...UPPER AIR ANALYSIS SHOWS A WEAK EAST-WEST
ORIENTED 500 MB TROUGH ACROSS EASTERN NORTH CAROLINA WITH A CLOSED
UPPER LOW OVER NORTHEASTERN FLORIDA. WHILE THE TROUGH GRADUALLY
LIFTS OUT...LEAVING EASTERN NC IN A COL AREA...THERE IS STILL SOME
DECENT MID-LEVEL VORTICITY AROUND DURING THE MID-AFTERNOON HOURS. AT
THE SURFACE A TROUGH LINGERS OVER THE PIEDMONT REGION AS HIGH PRESSURE
WELL OFFSHORE CONTINUES TO PROVIDE WARM...MOISTURE AND UNSTABLE TO
EASTERN NC. BOTH THE RAP AND GFS INDICATE THAT GIVEN MAX
TEMPERATURES INTO THE LOWER 90S AND DEWPOINTS IN THE LOWER AND
MIDDLE 70S LATER THIS AFTERNOON...CAPE VALUES IN EXCESS OF 3000
J/KG AND LI VALUES OF -6 TO -8 ARE FORECAST. GIVEN THESE
FACTORS...THINK ANOTHER GOOD COVERAGE OF SHOWERS AND TSTMS CAN BE
EXPECTED WITH THE HIGHEST PROBABILITY IN AREAS SIMILAR TO
YESTERDAY OVER THE NORTHWESTERN CWA WITH POPS TAPERING BACK TO
MINIMAL NEAR THE SOUTHERN COASTAL AREA. WILL AGAIN HIGHLIGHT
LOCALLY STRONG STORMS IN THE HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...SHOWERS AND TSTMS WILL ONCE AGAIN DISSIPATE
WITH LOSS OF HEATING AFTER ABOUT 02Z. MINIMUM TEMPERATURES WILL
AGAIN BE BETWEEN 73 AND 78 DEGREES WITH LIKELY SOME LEFTOVER HIGH
DEBRIS CLOUDS FROM ANY CONVECTION THAT DEVELOPS DURING THE
AFTERNOON AND EVENING HOURS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 330 AM TUE...LONG TERM PERIOD WILL FEATURE THE POTENTIAL FOR
PERIODS OF WIDESPREAD HEAVY RAIN THIS WEEKEND. FOR WED AND THUR...E
NC WILL REMAIN IN TYPICAL SUMMER REGIME WITH ISO-SCT AFTERNOON
THUNDERSTORMS MAINLY ASSOCIATED WITH SEA BREEZE FRONT.
WEAKNESS IN THE MID LEVELS WILL BRING A CHANCE OF DIURNAL CONVECTION
ACROSS INLAND AREAS WED AFTERNOON. SUBTROPICAL MOISTURE WILL STREAM
NORTHEASTWARD OFF THE COAST WED NIGHT...AND WILL BRING SCT
THUNDERSTORMS FOR THE COASTAL WATERS. SOME OF THIS CONVECTION MAY
ADVECT OFF THE OCEAN AND AFFECT THE COASTAL COUNTIES LATE WED NIGHT.
FOR THUR...PIEDMONT THERMAL TROUGH WILL STRENGTHEN SOMEWHAT IN
RESPONSE TO BUILDING CENTRAL CONUS RIDGE AND DIGGING OF EASTERN
CONUS TROUGH. SOMEWHAT BETTER CHANCE FOR MORE ORGANIZED CONVECTION
WELL INLAND NEARER THE THERMAL TROUGH. BOTH GFS AND ECMWF IN FAIRLY
GOOD AGREEMENT WITH THE SYNOPTIC REGIME THROUGH THIS WEEKEND...
THOUGH SOME TIMING DIFFERENCES IN ARRIVAL OF SFC BOUNDARY THAT WILL
SET THE STAGE FOR POSSIBLE PERIODS OF HEAVY RAIN THIS WEEKEND. SIDED
WITH MORE CONSISTENT/SLOWER ECM SOLN...AS THIS HAS SUPPORT FROM ITS
ENSEMBLE MEAN...GEFS ENSEMBLE MEAN SOLN...AND OPERATIONAL 17/00Z
CANADIAN MODEL. THIS SOLN HANGS UP THE EAST-WEST ORIENTED FRONT
THROUGH THE WEEKEND...AND WITH PWATS AROUND 2.25 INCHES OR HIGHER...
COULD BRING THREAT FOR FLOODING. IF THESE PWAT VALS COME TO
FRUITION...THEY WOULD BE NEAR THE 99TH PERCENTILE FOR CLIMATOLOGICAL
VALUES FOR JULY...WHICH COULD CERTAINLY POSE THREAT FOR FLOODING
RAINS. THE UNSETTLED WEATHER MAY LINGER INTO THE BEGINNING OF NEXT
WEEK.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 00Z WEDNESDAY/...
AS OF 1250 AM TUESDAY...WILL CONTINUE PREVIOUS TAF FORECAST OF
SHOWING SOME PATCHY FOG AT EWN WHERE HEAVY RAINFALL OCCURRED IN
THUNDERSTORMS EARLIER THIS EVENING. OTHERWISE...EXPECT VFR
CONDITIONS WITH A BIT OF A LIGHT SOUTHWEST BREEZE PREVENTING ANY
DENSE FOG AT THE REMAINING TERMINALS. ONCE AGAIN...SCATTERED TSTMS
WILL BE A GOOD POSSIBILITY LATER TODAY...ESPECIALLY AT KPGV AND
PERHAPS AGAIN AT KEWN/KISO.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUESDAY...MAINLY VFR CONDITIONS OTHER THAN SOME TEMPO
REDUCTION TO VSBYS/CIGS LATE AT NIGHT/EARLY IN THE MORNING DUE TO
RADIATION FOG/BR. SMALL CHANCES OF AFTERNOON THUNDERSTORMS DUE TO
SEA BREEZE FRONT PROPAGATING INLAND EACH AFTERNOON. BETTER CHANCE
FOR WIDESPREAD RAIN AND THUNDERSTORMS ARRIVES ON FRIDAY AND WILL
LINGER INTO THE WEEKEND...WITH PERIODS OF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY...
AS OF 345 AM TUESDAY...THE SAME PATTERN THAT WE HAVE SEEN OVER THE
PAST SEVERAL DAYS WILL CONTINUE. GRADIENT BETWEEN SURFACE TROUGH
OVER THE PIEDMONT REGION AND THE SEMI-PERMANENT BERMUDA HIGH
OFFSHORE WILL LEAD TO STOUTEST WINDS OF 10 TO 15 KNOTS WITH
OCCASIONAL GUSTS TO 20 KNOTS. SEAS WILL RUN 2 TO 4 FEET WITH
OCCASIONAL 5 FOOT SEAS OVER THE OUTER WATERS...ESPECIALLY IN THE
CENTRAL WATERS.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUE...LATEST RUN OF THE MAJOR MODELS IN VERY CLOSE
AGREEMENT THROUGH LATE WEEK. STILL PREFER THE 00Z ECMWF HANDLING OF
THE SOUTHWARD MOVING COOL FRONT THIS WEEKEND...WHICH HANGS UP THE
FRONT OVER EASTERN NC THIS WEEKEND. THE GFS PUSHES THE FRONT TO THE
SOUTH WHICH IS HARD TO DO THIS TIME OF YEAR. SOUTHWEST FLOW
CONTINUES THROUGH FRIDAY. EXPECTING A NORTHEAST FLOW OVER THE
CENTRAL AND NORTHERN WATERS SATURDAY AND SUNDAY NORTH OF THE FRONT
WITH A SOUTHWEST FLOW OVER THE SOUTHERN WATERS. STILL LOOKING AT
SMALL CRAFT SEAS DEVELOPING OVER THE CENTRAL AND SOUTHERN WATERS
LATE WED NIGHT THROUGH FRIDAY NIGHT AHEAD OF THE FRONT. WINDS AND
SEAS SHOULD FALL BELOW SCA THIS WEEKEND WITH FRONT OVERHEAD.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1045 AM CDT TUE JUL 17 2012
.DISCUSSION...
15 UTC SURFACE ANALYSIS SHOWS A LOW PRESSURE CENTER ACROSS SOUTH-
CENTRAL SD AND A WEAK FRONTAL BOUNDARY EXTENDING EASTWARD INTO
SOUTHWEST MN. SHOWERS AND ISOLATED THUNDER HAVE BEEN CONFINED TO
A NARROW CORRIDOR COINCIDENT WITH BEST MID-LEVEL CONVERGENCE ALONG
AND SOUTH OF A LINE FROM MOBRIDGE SD TO WAHPETON TO PARK RAPIDS.
THERE IS A SECONDARY CONVECTIVE CLUSTER ALONG I-94 WEST OF
BISMARCK...MOVING TO THE EAST-NORTHEAST AROUND 20 KTS. NORTHEAST
SURFACE FLOW...COMBINED WITH DRIER MID-LEVELS AND LITTLE TO NO
INSTABILITY SHOULD RESULT IN THESE SHOWERS AND STORMS DISSIPATING
LATER THIS MORNING. AS SUCH...FOCUSED CHANCE POPS LATE THIS
MORNING ACROSS THE SOUTH...DECREASING TO SLIGHT CHANCE THIS
AFTERNOON. LATEST HRRR DOES SUGGEST ACTIVITY FARTHER WEST WILL
HOLD TOGETHER...SO WILL NEED TO MONITOR LATEST OBSERVATIONS AND
ADJUST FORECAST IF PRECIPITATION HOLDS TOGETHER ACROSS EASTERN ND.
WARMEST TEMPERATURES ALOFT ARE ACROSS THE SOUTH TODAY...BUT
SIGNIFICANT CONVECTIVE DEBRIS FROM OVERNIGHT HAS LIMITED
TEMPERATURE RISE THIS MORNING. AREAS FARTHER NORTH WILL SEE MORE
SUN...BUT COOLER TEMPERATURES ALOFT. ALL SAID...HIGHS THIS
AFTERNOON WILL BE A BALANCE BETWEEN CLOUD COVER AND BOUNDARY LAYER
THERMAL PROFILE...MAXING OUT IN THE UPPER 70S TO LOWER 80S. DID
DECREASE A DEGREE OR TWO ACROSS THE SOUTH WHERE PREVIOUS FORECAST
CURVE WAS RISING TOO FAST.
&&
.AVIATION...
PATCHY MVFR CIGS LIKELY TO SCATTER OUT THIS AFTERNOON AS SOME DRYING
IN THE LOWER LEVELS TAKES HOLD. TSRA TO BE CONFINED TO AREAS ALONG
ND/SD/MN BORDER AREA.
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT TUE JUL 17 2012/
DISCUSSION...FORECAST CHALLENGE CONCERNS MAINLY SHORT TERM PCPN
CHANCES...TEMPERATURES AND NEAR TERM AVIATION/CLOUD TRENDS. MODELS
IN GOOD AGREEMENT WITH MAIN FEATURES WITH GFS ACTUALLY DOING BEST
WITH LOW LEVEL MOISTURE FIELDS. WILL USE BLEND FOR FORECAST
CHALLENGE.
CURRENT CONVECTION ORIENTED ALONG ND/SD BORDER AREA VCNTY ELEVATED
BOUNDARY IN MOIST AXIS WITH SUPPORT FROM ENTRANCE REGION OF UPPER
JET MAXIMA. FAVORED CONVECTIVE PARAMETERS REMAIN ACROSS NE SD TO
SD/ND BORDER AREA THROUGH THE MORNING. WITH JET MAXIMA SHIFTING EAST
THIS MORNING WOULD EXPECT CONVECTION TO GRADUALLY DIMINISH. WILL
MONITOR TRENDS FOR MORNING POPS HOWEVER WILL LIKELY CONFINE ANY POPS
TO ALONG AND SOUTH OF I94 CORRIDOR. FOR TEMPERATURES PATCHY MVFR
CIGS BECOMING MASKED BY UPPER LEVEL CONVECTIVE DEBRIS CLOUDS. COLUMN
CONTINUES TO COOL SLIGHTLY TODAY IN WAKE OF BOUNDARY PASSAGE. GFS
HINTS AT SOME DRYING IN LOWER LEVELS SO FEEL THERE WILL AT THE LEAST
BE SOME PARTIAL SUNSHINE. WARMEST AIR ACROSS THE SOUTH HOWEVER
CLOUDS LIKELY TO STICK AROUND LONGER WITH CURRENT CONVECTION.
OVERALL LOOKING AT COOLER MORE SEASONAL TEMPERATURES TODAY.
SURFACE AND ELEVATED BOUNDARY MOVES VERY LITTLE OVER THE NEXT 24-36
HOURS. ALONG WITH DAY TIME HEATING MODELS HINTING AT ANOTHER
WEAK WEAK IMPULSE TO INTERACT WITH NEAR STATIONARY BOUNDARY FOR MORE
CONVECTIVE DEVELOPMENT ACROSS NORTHERN HIGH PLAINS THIS AFTERNOON.
THIS CONVECTION LIKELY TO PROPAGATE ALONG ND/SD BORDER AGAIN LATER
TONIGHT ALONG LOW LEVEL MOISTURE AXIS. AT THIS POINT WILL HOLD OFF
ANY ANY SEVERE MENTION ALTHOUGH ANY CHANCES LIKELY CONFINED TO
BORDER AREA. FARTHER NORTH EASTERLY FLOW/UPSLOPE WILL LIMIT ANY
PCPN CHANCES TO FAR WESTERN FA AT BEST. ALTHOUGH CONFIDENCE LOW WILL
INTRODUCE SLIGHT CHANCE POPS TO FAR WEST WITH BETTER CHANCES
CONTINUING ALONG ND/SD/MN BORDER AREA. MORE COMFORTABLE MINIMUM
TEMPERATURES WILL CONTINUE ACROSS MOST AREAS.
COULD SEE SOME LINGERING CONVECTION ACROSS FAR SOUTH WEDNESDAY AM
AND WILL INTRODUCE LOW POPS TO THIS AREA. REMAINDER LIKELY TO REMAIN
DRY AND AM HESITANT TO SPREAD POPS FURTHER WEST AND NORTH WITH
CURRENT DRY CONDITIONS AND DRIER EASTERLY FLOW. TEMPERATURES AGAIN
LOOK TO BE AT OR A LITTLE BLO SEASONAL AVERAGES.
HEIGHTS BUILD LATER IN THE WORK WEEK WITH INCREASING SOUTHERLY FLOW
AND WARM ADVECTION. THIS WILL ALLOW TEMPERATURES TO RECOVER BACK
ABOVE AVERAGE. WITH LACK OF ANY LOW LEVEL CONVERGENCE AND LOW LEVEL
JET CONVERGENCE WELL TO OUR WEST AND PCPN CHANCES LOOK MINIMAL. AT
THIS POINT WILL STAY CONSISTENT AND LEAVE POPS AS IS AS CONDITIONS
OVERALL LOOK DRY.
LONG TERM (FRI-MON)...
MODELS IN GOOD AGREEMENT WITH THE EXTENDED PERIOD WITH WRT 500MB
FLOW. RIDGING CONTINUES TO BUILD INTO THE NORTHERN PLAINS FRIDAY
WITH THE THERMAL AXIS TO MOVE OVER THE CWFA ON SATURDAY. SLGT CHC
POPS CONTINUE AS CONVECTION IS POSSIBLE AS COMPLEXES RIDE THE RIDGE
ON THE EDGE OF THE CAP...THOUGH WIDE SPREAD RAINFALL IS NOT
EXPECTED. UPPER 80 ANS LOW 90S ON FRI AND SAT. WIND SHIFT SATURDAY
NIGHT WILL ALLOW TEMPS TO RETURN TO NEAR MID SUMMER NORMALS FOR THE
BEGINNING OF THE WEEK..
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/WJB/VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
937 AM CDT TUE JUL 17 2012
.DISCUSSION...BOWMAN RADAR THIS MORNING DEPICTING A MID LEVEL
SHORTWAVE SPINNING NEAR KDIK WHICH IS MOVING NORTHEAST WITH TIME.
AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH THIS
DISTURBANCE WILL CONTINUE TO MIGRATE NORTHEAST THROUGH 18Z AND
HAVE INCREASED POPS ACROSS NORTH CENTRAL NORTH DAKOTA...WHICH IS
WHAT THE HRRR MODEL IS ALSO IMPLYING. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SHOULD SUFFICE TO COVER THIS SHORTWAVE.
THE WEST/SOUTHWEST/AND FAR SOUTH CENTRAL IS UNDER A SLIGHT RISK
FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. THE HRRR IS SUGGESTING
AN AREA OF THUNDERSTORMS DEVELOPING OVER SOUTHWEST NORTH DAKOTA
EARLY THIS AFTERNOON AND THEN PROGRESSING EAST. LATEST VISIBLE
IMAGERY ALREADY SHOWING SOME CLEARING IN THE SOUTHWEST AND WILL
NEED TO WATCH THIS AREA BY 18Z. THE HRRR/GFS SHOW MORE
THUNDERSTORMS DEVELOPING OVER EASTERN MONTANA THIS EVENING AND THIS
SHOULD BE THE MAIN ACTION WITH THE UPPER SHORTWAVE THAT ROLLS
THROUGH TONIGHT. FOR TONIGHT...A POSSIBLE MCS COULD DEVELOP PER
SPC OVER SOUTH DAKOTA OR SOUTHERN NORTH DAKOTA. HEAVY RAIN/LARGE
HAIL AND/OR DAMAGING WINDS WILL BE THE MAIN THREATS. WILL FOCUS ON
THIS DURING THE AFTERNOON AND EVENING UPDATES.
&&
.AVIATION...AT 930 AM CDT...A STATIONARY FRONTAL BOUNDARY EXTENDED
EAST-WEST ACROSS SOUTH DAKOTA...THEN EXTENDED FROM NORTHWESTERN
SOUTH DAKOTA ACROSS EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN. THE
FRONT ACROSS SOUTH DAKOTA WILL BE THE FOCUS FOR THUNDERSTORMS ACROSS
THE SOUTHERN THIRD OF NORTH DAKOTA THIS MORNING. A MOIST EAST TO
NORTHEASTERLY LOW LEVEL FLOW ACROSS NORTH DAKOTA WAS BRINGING MVFR
TO OCNL IFR CONDITIONS. HAZARDS TO AVIATION TODAY INCLUDE MVFR TO
OCNL IFR CONDITIONS INCLUDING KISN/KMOT/KJMS/KBIS/KDIK THROUGH 18Z
TUESDAY. THUNDERSTORMS WILL CONTINUE TO FORM AND TRACK ACROSS THE
SOUTHERN THIRD OF THE STATE AS WELL AS FAR WESTERN NORTH DAKOTA.
THIS SHOULD IMPACT KISN/KDIK/KBIS/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
125 PM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...DID ELECT TO ADD AT LEAST A SLIGHT CHANCE OF POPS
CWA WIDE THIS AFTERNOON. IN THE MOIST...HUMID...ATMOSPHERE...DONT
FEEL CAN TOTALLY RULE IT OUT DURING PEAK DAYTIME HEATING. IN
ADDITION...NAM SUGGESTING UPPER AIR DISTURBANCES ROUNDING RIDGE
COULD TRIGGER STORMS IN THE EASTERN PARTS OF CWA...ALTHOUGH GREATER
CHANCES EXIST WEST OF THE CWA. ALSO DID BUMP UP MAX TEMPS A DEGREE OR
SO IN A FEW LOCATIONS FOR TODAY BASED ON THE FACT THAT WE ARE
ALREADY SEVERAL DEGREES WARMER IN MANY LOCATIONS THAT THE CURRENT
GUIDANCE WOULD SUGGEST...AND WITH A LACK OF CLOUD COVER THIS
AM...SHOULD GET SOME DECENT HEATING GOING. CURRENT HEAT ADVISORY
LOCATION LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
18Z TUESDAY THROUGH 18Z WEDNESDAY...
MAINLY VFR CONDITIONS FOR THE PERIOD. SCATTERED SHOWERS AND
THUNDERSTORMS ARE DEVELOPING ON RADAR...AND ARE EXPECTED TO
CONTINUE THROUGH ABOUT 02Z...WHEN LOSS OF DAYTIME HEATING ALLOWS
THEM TO DISSIPATE. GREATEST CHANCE FOR CONVECTION IS IN SOUTHEAST
OHIO...EASTERN KENTUCKY...AND SOUTHERN WV. EXPECT BRIEF HEAVY
DOWNPOURS AND GUSTY WINDS IN VICINITY OF STORMS. ALSO...BRIEF MVFR
CONDITIONS ARE ALSO POSSIBLE IN VICINITY OF STORMS.
STORMS WILL DISSIPATE AFTER 02Z. CLOUDS WILL BE ON THE INCREASE
OVERNIGHT IN ADVANCE OF A COLD FRONT...PROGGED TO MOVE INTO THE
AREA WEDNESDAY NIGHT. INCREASING CLOUDS SHOULD HELP TO PREVENT
WIDESPREAD FOG FORMATION TONIGHT...HOWEVER...PATCHY IFR/MVFR FOG
IS STILL EXPECTED IN FAVORED MOUNTAIN/RIVER VALLEYS. ANY FOG THAT
DOES DEVELOP WILL DISSIPATE AFTER 13Z. OTHERWISE...SHOWERS AND
STORMS WILL BE ON THE INCREASE AFTER 14Z IN ADVANCE OF THE
APPROACHING COLD FRONT. EXPECT HEAVY DOWNPOURS...BRIEF GUSTY
WINDS...AND MVFR/IFR CONDITIONS IN VICINITY OF STORMS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: IF CLOUDS SLOWER TO ENTER AREA
TONIGHT...COULD SEE MORE WIDESPREAD FOG DEVELOP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
NIGHT AND AGAIN ON THURSDAY AND THURSDAY NIGHT...WITH IFR IN HEAVIER
SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ005>011-014.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ/SL
SHORT TERM...KMC
LONG TERM...SL
AVIATION...SL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
957 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...DID ELECT TO ADD AT LEAST A SLIGHT CHANCE OF POPS
CWA WIDE THIS AFTERNOON. IN THE MOIST...HUMID...ATMOSPHERE...DONT
FEEL CAN TOTALLY RULE IT OUT DURING PEAK DAYTIME HEATING. IN
ADDITION...NAM SUGGESTING UPPER AIR DISTURBANCES ROUNDING RIDGE
COULD TRIGGER STORMS IN THE EASTERN PARTS OF CWA...ALTHOUGH GREATER
CHANCES EXIST WEST OF THE CWA. ALSO DID BUMP UP MAX TEMPS A DEGREE OR
SO IN A FEW LOCATIONS FOR TODAY BASED ON THE FACT THAT WE ARE
ALREADY SEVERAL DEGREES WARMER IN MANY LOCATIONS THAT THE CURRENT
GUIDANCE WOULD SUGGEST...AND WITH A LACK OF CLOUD COVER THIS
AM...SHOULD GET SOME DECENT HEATING GOING. CURRENT HEAT ADVISORY
LOCATION LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SOME PATCHES OF MAINLY MVFR FOG FLOATING AROUND THE FORECAST AREA
THIS MORNING...EXPECTING THINGS RETURN TO VFR SHORTLY AND REMAIN
THERE FOR BULK OF THE DAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON THIS
AFTERNOON...WHICH COULD BRING ABOUT SOME BRIEF PERIODS OF MVFR IN
THE HEAVIEST SHOWERS. EXPECTING ENOUGH WIND AND INCOMING CLOUDS TO
PRECLUDE MUCH FOG WEDNESDAY MORNING...HOWEVER KEKN WILL BE THE
LAST TO SEE THE INCOMING CLOUDS SO PUT IN SOME IFR FOG THERE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG DISSIPATION MAY
VARY THIS MORNING. IF CLOUDS SLOWER TO ENTER AREA TONIGHT...COULD
SEE MORE WIDESPREAD FOG DEVELOP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ005>011-014.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ/SL
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
646 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SOME PATCHES OF MAINLY MVFR FOG FLOATING AROUND THE FORECAST AREA
THIS MORNING...EXPECTING THINGS RETURN TO VFR SHORTLY AND REMAIN
THERE FOR BULK OF THE DAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON THIS
AFTERNOON...WHICH COULD BRING ABOUT SOME BRIEF PERIODS OF MVFR IN
THE HEAVIEST SHOWERS. EXPECTING ENOUGH WIND AND INCOMING CLOUDS TO
PRECLUDE MUCH FOG WEDNESDAY MORNING...HOWEVER KEKN WILL BE THE
LAST TO SEE THE INCOMING CLOUDS SO PUT IN SOME IFR FOG THERE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG DISSIPATION MAY
VARY THIS MORNING. IF CLOUDS SLOWER TO ENTER AREA TONIGHT...COULD
SEE MORE WIDESPREAD FOG DEVELOP.
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 H H H
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 H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
WVZ005>011-014.
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ066-067-075-076-083>087.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
305 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL RIDGE
BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL MOISTURE
AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION TODAY. NAM
DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN CENTRAL
KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH THERE. GFS
PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO EXPANDED
THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR THIS
AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
AREAS OF FOG STARTING TO SHOW UP IN OBS...LIKE KEKN. IN GENERAL
EXPECT AREAS OF MVFR VISIBILITIES THROUGH 12Z OR SO...DROPPING
INTO IFR IN MOST PRONE LOCATIONS LIKE KEKN. SHOULD RETURN TO VFR
FOR BULK OF THE DAY TUESDAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON TUESDAY
AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 07/17/12
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 M M M H H M 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...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
WVZ005>011-014.
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ066-067-075-076-083>087.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
741 PM EDT WED JUL 18 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH THE
WEEK...WHILE A WEAK TROUGH OF LOW PRESSURE LINGERS INLAND THROUGH
FRIDAY. A COLD FRONT WILL APPROACH FROM THE NORTH SATURDAY...YET
DISSIPATE SUNDAY AS THE ATLANTIC HIGH BUILDS BACK INTO THE AREA.
A LEE SIDE TROUGH WILL DEVELOP AGAIN FOR NEXT TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RECENTLY UPDATED OUR GRIDDED AND TEXT PRODUCTS TO KEEP UP WITH TRENDS
IN TEMPERATURES AND CONVECTIVE TRENDS. OVERALL IT/S LOOKING LIKE
POTENTIAL FOR SCATTERED SHOWERS AND TSTMS IS WANING. OUR WESTERN ZONES
HAVE LITTLE IN THE WAY OF CUMULUS TOWERS PER LATEST VISIBLE DESPITE
GOOD LATE DAY INSOLATION. THE BULK OF THE CONVECTION IS FIRING ON THE
N SIDE OF THE UPPER LOW IN THE LEE SIDE SURFACE TROUGH TO THE NW OF
THE FORECAST AREA.
THE OTHER REGION OF TSTMS WERE DOWN TO THE S OF THE ALTAMAHA RIVER
AND THE RUC RAPID REFRESH WHICH DEPICTS THIS ACTIVITY...GENERALLY
WEAKENS IT IN THE NEXT 1-2 HOURS. OVERALL WE HAVE DIMINISHED POPS TO
15-20 PERCENT IN MANY AREAS. WE MAINTAINED CHANCE POPS TO THE S OF
I-16 IN GEORGIA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THE PERSISTENT TUTT FEATURE WILL GRADUALLY DISSIPATE ON
THURSDAY...LEAVING A BROAD UPPER TROUGH ALONG THE EAST COAST AND AN
ATLANTIC RIDGE OTHERWISE IN CONTROL OF THE PATTERN ALOFT. THE
SURFACE PATTERN WILL BE DEFINED BY AN INLAND TROUGH LINGERING ACROSS
THE CENTRAL CAROLINAS THROUGH FRIDAY...WHILE ATLANTIC HIGH PRESSURE
STRETCHES TOWARD THE COASTLINE INTO THE WEEKEND.
DECENT DEEP LAYER MOISTURE WILL REMAIN OVER THE MID ATLANTIC AND
SOUTHEAST STATES...AS SEEN IN PWAT VALUES NEAR OR SLIGHTLY ABOVE 2
INCHES. WHEN COMBINED WITH WARM TEMPERATURES PEAKING IN THE LOW TO
MID 90S AND MODERATE INSTABILITY...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON EACH DAY. THERE WILL
BE NUMEROUS BOUNDARIES FOR INITIATING AND ENHANCING
CONVECTION...INCLUDING THE SEA BREEZE...LAKE BREEZES FROM LAKE
MOULTRIE/MARION...DIFFERENTIAL HEATING BOUNDARIES...AS WELL AS
OUTFLOWS THAT DEVELOP ONCE CONVECTION GETS UNDERWAY. A COLD FRONT
WILL BE DESCENDING AND LIKELY STALLING TO THE NORTH BY
SATURDAY...AND CONVECTIVE COVERAGE WILL LIKELY INCREASE ACROSS
NORTHERN AREAS AS A RESULT. EXPECT MAINLY PULSE TYPE STORMS THURSDAY
AND FRIDAY...EXCEPT WHERE BOUNDARY COLLISIONS OCCUR AND POTENTIALLY
INITIATE MULTICELL CLUSTERS. ISOLATED THUNDERSTORMS COULD BECOME
SEVERE...WITH THE MAIN THREATS BEING HEAVY RAINFALL AND WET
DOWNBURSTS PRODUCING LOCALLY DAMAGING WINDS. DEPENDING ON THE
PROXIMITY OF THE FRONT ON SATURDAY...CONVECTION COULD BECOME MORE
ORGANIZED. WILL CONTINUE TO INDICATE PRECIPITATION CHANCES IN THE 30
TO 40 PERCENT RANGE THURSDAY...INCREASING INTO THE 40 PERCENT RANGE
TO NEAR 50 PERCENT FRIDAY AND SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE COLD FRONT TO THE NORTH WILL DISSIPATE SUNDAY...AS ATLANTIC
RIDGING BOTH AT THE SURFACE AND ALOFT BUILDS ACROSS THE AREA INTO
MONDAY. HOWEVER...THE RIDGE ALOFT RETROGRADES WESTWARD FROM THE
ATLANTIC INTO THE NORTHERN GULF BY TUESDAY AND WEDNESDAY...WHILE
AT THE SAME TIME A SURFACE TROUGH AGAIN SETS UP TO THE LEE OF THE
APPALACHIANS. WHILE HEIGHTS ALOFT ARE HIGHER DURING THIS TIME...
THERE IS STILL A WEST AND NORTHWEST FLOW ALOFT TO ALLOW FOR
UPSTREAM CONVECTION TO FORM AND INTERACT WITH LOW LEVEL MESOSCALE
BOUNDARIES. THUS...FEEL OBLIGATED TO HOLD ON TO SLIGHT CHANCE OR
EVEN CHANCE POPS THROUGHOUT THE ENTIRE LONG TERM PERIOD.
CONVECTION WILL BE DIURNALLY DRIVEN...WITH ISOLATED PULSE SEVERE
WEATHER NOT OUT OF THE QUESTION WITHIN THE AFOREMENTIONED WEST AND
NORTHWEST FLOW ALOFT. TEMPERATURES WILL BE NEAR NORMAL VALUES.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
MAINLY VFR CONDITIONS THROUGH 00Z/20. ONCE AGAIN...THE MAIN RISK
FOR CONVECTION DIRECTLY IMPACTING THE TERMINALS WILL BE DURING
THE AFTERNOON HOURS ON THURSDAY. KSAV RECEIVED AROUND 1 INCH OF
RAIN WED AND THERE COULD BE SOME PATCHY LOW CLOUDS OR FOG AROUND
DAYBREAK PRODUCING SUB-VFR CONDITIONS...ALTHOUGH BOTH THE DEEP
MOISTURE PROFILE AND WARM LOW LEVELS SUGGEST THIS CHANCE IS LOW-
END.
&&
.MARINE...
AN ENHANCED GRADIENT BETWEEN AN INLAND TROUGH AND ATLANTIC HIGH
PRESSURE WILL SUPPORT SLIGHTLY HIGHER WINDS AND SEAS ACROSS THE
MARINE ZONES. A TYPICAL SOUTHWEST FLOW WILL PREVAIL THROUGH THE
ENTIRE PERIOD...WITH VEERING AT NIGHT UNDER LAND BREEZE
CIRCULATIONS...AND BACKING DURING THE DAYTIME HOURS WITH THE SEA
BREEZE. THERE WILL BE PERIODIC SURGES...EITHER FROM THE SEA BREEZE
DEVELOPMENT AND/OR FROM NOCTURNAL LOW LEVEL JETTING. AS A
RESULT...WINDS WILL BE AS HIGH AS HIGH AS 15 KT...EVEN
OCCASIONALLY CLOSE TO 20 KT. SEAS WILL GENERALLY HOLD IN THE 2 TO
4 FT RANGE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH BY THE
WEEKEND...AND WITH WEAK LOW PRESSURE DEVELOPING ALONGSIDE...EXPECT
A WEAKENING PRESSURE GRADIENT TO RESULT.
RIP CURRENTS...A PERSISTENT 2 FT 10 SEC SWELL IS EVIDENT FROM
LOCAL BUOY REPORTS...AND CONSIDERING THE NEW MOON ON THURSDAY...
HAVE EXTENDED A MODERATE RISK FOR RIP CURRENTS FOR ALL AREA
BEACHES THURSDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...79
LONG TERM...RJB
AVIATION...
MARINE...JRL/RJB/79
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1055 PM CDT WED JUL 18 2012
.DISCUSSION.../ISSUED AT 815 PM CDT/
QUIET EVENING CONTINUES ACROSS THE REGION. WEAK AND SLOW MOVING
BOUNDARY EXTENDING FROM NEAR SLAYTON TO SIOUX FALLS TO YANKTON
KICKED UP SOME TOWERING CUMULUS THIS AFTERNOON BUT THESE CLOUDS...AS
SEEN ON SATELLITE...ARE RAPIDLY DIMINISHING. DO NOT EXPECT ANY
ADDITIONAL DEVELOPMENT OVERNIGHT WITH THE SLOW MOVING STORMS OVER
NORTH CENTRAL NEBRASKA EXPECTED TO REMAIN WELL SOUTH OF THE FORECAST
AREA. TWEAKED POPS TO KEEP THE CWA DRY THIS EVENING...OTHERWISE
FORECAST LOOKS GOOD.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. EASTERLY FLOW IS
EXPECTED TO PERSIST ACROSS THE AREA THROUGH THE FORCAST
PERIOD...INCREASING AFTER 00Z FRIDAY.
&&
.PREV DISCUSSION.../ISSUED AT 403 PM CDT/
CURRENTLY SEEING CLEARING SKIES IN THE SUBSIDENCE ZONE BEHIND THIS
MORNINGS AND EARLY AFTERNOON CONVECTION. INSTABILITY BEGINNING TO
RECOVER OVER THE CWA...BUT ATMOSPHERE REMAINS STRONGLY CAPPED. FEEL
THIS WILL REMAIN THE CASE THROUGH THE EVENING HOURS OVER MUCH OF THE
AREA. HRRR AND SREF SHOWING SOME REDEVELOPMENT FROM BROOKINGS EAST
INTO SOUTHWEST MINNESOTA THIS EVENING. NOT REALLY MUCH OF ANY
FORCING...OTHER THAN MAYBE SOME WEAK CONVERGENCE. THUS THINK
ANYTHING THAT FORMS IN THIS AREA WILL BE ISOLATED AT BEST. OTHERWISE
WILL SEE CLEARING SKIES AND GENERALLY LIGHT WINDS TONIGHT. COULD SEE
SOME LOW CLOUDS AND OR FOG DEVELOP LATE TONIGHT INTO TOMORROW
MORNING...WITH THE BEST CHANCE ACROSS SOUTHWEST MINNESOTA WHERE
MIXING WAS LEAST TODAY. LOWS TONIGHT WILL BE A BIT
COOLER...GENERALLY UPPER 60S SOUTHWEST MINNESOTA TO LOW 70S ALONG
THE MISSOURI RIVER.
THURSDAY WILL BE ANOTHER HOT DAY OVER THE REGION UNDER MOSTLY SUNNY
SKIES. 850 MB TEMPERATURES LIKELY TO RANGE FROM AROUND 22C IN THE
EAST TO 28C IN THE WEST. EXPECT DEEP MIXING...ESPECIALLY ALONG AND
WEST OF INTERSTATE 29. THIS WILL RESULT IN HIGHS CLOSER TO THE
WARMER MET GUIDANCE...IN THE UPPER 80S TO AROUND 90 SOUTHWEST
MINNESOTA...LOW TO MID 90S IN THE INTERSTATE 29 CORRIDOR...AND
AROUND 100 WEST OF THE JAMES RIVER. DEWPOINTS WILL LIKELY MIX INTO
THE 50S WHERE TEMPERATURES ARE HOTTEST...SO THINKING IS MOST AREAS
GENERALLY REMAIN AT 100 OR BELOW FOR HEAT INDICES. /CHENARD
STRENGTHENING UPPER RIDGE LOOKS TO PROTECT THE AREA FROM PRECIP
THROUGH THE REMAINDER OF THE SHORT TERM...AT LEAST UNTIL SATURDAY
WHEN MAY HEAT ENOUGH TO BREAK AN ISOLATED STORM NEAR THE FRONTAL
BOUNDARY ALONG THE NORTHWEST EDGE OF THE CWA. NOCTURNAL DEVELOPMENT
WILL LIKELY CYCLE NORTH AND EAST OF THE AREA...BUT A COUPLE OF
MODELS TRYING TO DEVELOP SYSTEMS AND DIVE SOUTH SOUTHEAST THROUGH
THE EASTERN HALF OF THE AREA. MIXING OF 850-925 THERMAL FIELDS
KEEP THE 100S IN THE GAME FOR FRIDAY AND ESPECIALLY SATURDAY...
MAINLY WEST OF INTERSTATE 29...AND FORECAST IS ACTUALLY SOMEWHAT
CONSERVATIVE FOR FAR WEST FRIDAY AND WEST OF I29 ON SATURDAY...
HANGING OUT CLOSER TO THE MEAN MIXED NUMBERS BETWEEN NAM/ECMWF.
AGAIN...BIG ISSUE ON POTENTIAL DEGREE OF HEAT HEADLINES WILL BE
DEGREE OF DEWPOINTS AND HOW FAR DOWN THEY MIX...OR HOW MUCH THE
MOISTURE CAN POOL. AT THIS TIME...AGAIN APPEARS THAT WORST OF
POSSIBLE CONDITIONS WILL BE LESSENED BY DEWPOINTS WHICH WILL MIX
INTO THE 50S...WHERE AFTERNOON READINGS REACH NEAR OR ABOVE 100
DEGREES. THE FARTHER EAST LOCATIONS WILL KEEP HANGING ON TO HIGHER
DEWPOINTS...BUT WILL NOT WARM QUITE AS MUCH. CURRENT ISSUANCE OF
HEAT ADVISORY IS DEFINED MORE BY WHERE IS EXPECTED TO TAKE EFFECT ON
THURSDAY. WILL LIKELY NOT BE THE FINAL EVOLUTION...AND EXPECT TO ADD
ON OVER THE NEXT DAY OR TWO AREAS TOWARD THE EAST/SOUTHEAST FOR
CONDITIONS THAT DEVELOP ON FRIDAY THROUGH SUNDAY. NEVERTHELESS...
IT WILL CONTINUE HOT.
FOR THE EXTENDED RANGE /SATURDAY NIGHT THROUGH WEDNESDAY/...
CHANCES FOR RAIN REMAIN FAIRLY UNFOCUSED AND POORLY TIMED AT THAT...
AND BEYOND A WAVE WHICH WILL MOVE NORTH OF THE AREA MONDAY NIGHT
INTO TUESDAY...DID NOT SEE A GREAT NEED TO CARRY ANY LOW POPS AT
THIS TIME. RIDGE LOOKS TO GENERALLY REMAIN STRONG BEFORE HEIGHTS
START TO FALL AT VERY END OF THE PERIOD...BUT WITH BOUNDARY PRESSING
SOUTHWARD INTO WARMER AIR ALOFT...KEPT THIS ALSO CLEAR OF RAINFALL
CHANCES FOR THE TIME. EXPECT MAX TEMPS TO REMAIN HOT THROUGH THE
PERIOD...WITH BOUNDARY UNABLE TO MAKE ANY STRONG MOVES SOUTH...
WITH 90S TO AROUND 100 CONTINUING...AND LOWS MAINLY UPPER 60S TO MID
70S. STRETCHED DIURNAL RANGE A BIT FROM GUIDANCE WITH THE VERY DRY
CONDITIONS. /CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...HEAT ADVISORY FROM 1 PM THURSDAY TO 9 PM CDT SATURDAY FOR
SDZ050-052-057>060-063>065-068-069.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
815 PM CDT WED JUL 18 2012
.DISCUSSION.../ISSUED AT 815 PM CDT/
QUIET EVENING CONTINUES ACROSS THE REGION. WEAK AND SLOW MOVING
BOUNDARY EXTENDING FROM NEAR SLAYTON TO SIOUX FALLS TO YANKTON
KICKED UP SOME TOWERING CUMULUS THIS AFTERNOON BUT THESE CLOUDS...AS
SEEN ON SATELLITE...ARE RAPIDLY DIMINISHING. DO NOT EXPECT ANY
ADDITIONAL DEVELOPMENT OVERNIGHT WITH THE SLOW MOVING STORMS OVER
NORTH CENTRAL NEBRASKA EXPECTED TO REMAIN WELL SOUTH OF THE FORECAST
AREA. TWEAKED POPS TO KEEP THE CWA DRY THIS EVENING...OTHERWISE
FORECAST LOOKS GOOD.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LIGHT EASTERLY FLOW IS
EXPECTED TO PERSIST ACROSS THE AREA THROUGH THE OVERNIGHT HOURS. AS
BOUNDARY LAYER GROWS ON THURSDAY...MODELS SUGGEST WINDS MAY BECOME
NORTHWESTERLY BUT WOULD REMAIN LIGHT. FOR NOW...WITH WINDS
REMAINING LIGHT DID NOT MAKE A SEPARATE GROUPING FOR POTENTIAL LIGHT
NORTHWESTERLY WINDS TOMORROW AFTERNOON.
&&
.PREV DISCUSSION.../ISSUED AT 403 PM CDT/
CURRENTLY SEEING CLEARING SKIES IN THE SUBSIDENCE ZONE BEHIND THIS
MORNINGS AND EARLY AFTERNOON CONVECTION. INSTABILITY BEGINNING TO
RECOVER OVER THE CWA...BUT ATMOSPHERE REMAINS STRONGLY CAPPED. FEEL
THIS WILL REMAIN THE CASE THROUGH THE EVENING HOURS OVER MUCH OF THE
AREA. HRRR AND SREF SHOWING SOME REDEVELOPMENT FROM BROOKINGS EAST
INTO SOUTHWEST MINNESOTA THIS EVENING. NOT REALLY MUCH OF ANY
FORCING...OTHER THAN MAYBE SOME WEAK CONVERGENCE. THUS THINK
ANYTHING THAT FORMS IN THIS AREA WILL BE ISOLATED AT BEST. OTHERWISE
WILL SEE CLEARING SKIES AND GENERALLY LIGHT WINDS TONIGHT. COULD SEE
SOME LOW CLOUDS AND OR FOG DEVELOP LATE TONIGHT INTO TOMORROW
MORNING...WITH THE BEST CHANCE ACROSS SOUTHWEST MINNESOTA WHERE
MIXING WAS LEAST TODAY. LOWS TONIGHT WILL BE A BIT
COOLER...GENERALLY UPPER 60S SOUTHWEST MINNESOTA TO LOW 70S ALONG
THE MISSOURI RIVER.
THURSDAY WILL BE ANOTHER HOT DAY OVER THE REGION UNDER MOSTLY SUNNY
SKIES. 850 MB TEMPERATURES LIKELY TO RANGE FROM AROUND 22C IN THE
EAST TO 28C IN THE WEST. EXPECT DEEP MIXING...ESPECIALLY ALONG AND
WEST OF INTERSTATE 29. THIS WILL RESULT IN HIGHS CLOSER TO THE
WARMER MET GUIDANCE...IN THE UPPER 80S TO AROUND 90 SOUTHWEST
MINNESOTA...LOW TO MID 90S IN THE INTERSTATE 29 CORRIDOR...AND
AROUND 100 WEST OF THE JAMES RIVER. DEWPOINTS WILL LIKELY MIX INTO
THE 50S WHERE TEMPERATURES ARE HOTTEST...SO THINKING IS MOST AREAS
GENERALLY REMAIN AT 100 OR BELOW FOR HEAT INDICES. /CHENARD
STRENGTHENING UPPER RIDGE LOOKS TO PROTECT THE AREA FROM PRECIP
THROUGH THE REMAINDER OF THE SHORT TERM...AT LEAST UNTIL SATURDAY
WHEN MAY HEAT ENOUGH TO BREAK AN ISOLATED STORM NEAR THE FRONTAL
BOUNDARY ALONG THE NORTHWEST EDGE OF THE CWA. NOCTURNAL DEVELOPMENT
WILL LIKELY CYCLE NORTH AND EAST OF THE AREA...BUT A COUPLE OF
MODELS TRYING TO DEVELOP SYSTEMS AND DIVE SOUTH SOUTHEAST THROUGH
THE EASTERN HALF OF THE AREA. MIXING OF 850-925 THERMAL FIELDS
KEEP THE 100S IN THE GAME FOR FRIDAY AND ESPECIALLY SATURDAY...
MAINLY WEST OF INTERSTATE 29...AND FORECAST IS ACTUALLY SOMEWHAT
CONSERVATIVE FOR FAR WEST FRIDAY AND WEST OF I29 ON SATURDAY...
HANGING OUT CLOSER TO THE MEAN MIXED NUMBERS BETWEEN NAM/ECMWF.
AGAIN...BIG ISSUE ON POTENTIAL DEGREE OF HEAT HEADLINES WILL BE
DEGREE OF DEWPOINTS AND HOW FAR DOWN THEY MIX...OR HOW MUCH THE
MOISTURE CAN POOL. AT THIS TIME...AGAIN APPEARS THAT WORST OF
POSSIBLE CONDITIONS WILL BE LESSENED BY DEWPOINTS WHICH WILL MIX
INTO THE 50S...WHERE AFTERNOON READINGS REACH NEAR OR ABOVE 100
DEGREES. THE FARTHER EAST LOCATIONS WILL KEEP HANGING ON TO HIGHER
DEWPOINTS...BUT WILL NOT WARM QUITE AS MUCH. CURRENT ISSUANCE OF
HEAT ADVISORY IS DEFINED MORE BY WHERE IS EXPECTED TO TAKE EFFECT ON
THURSDAY. WILL LIKELY NOT BE THE FINAL EVOLUTION...AND EXPECT TO ADD
ON OVER THE NEXT DAY OR TWO AREAS TOWARD THE EAST/SOUTHEAST FOR
CONDITIONS THAT DEVELOP ON FRIDAY THROUGH SUNDAY. NEVERTHELESS...
IT WILL CONTINUE HOT.
FOR THE EXTENDED RANGE /SATURDAY NIGHT THROUGH WEDNESDAY/...
CHANCES FOR RAIN REMAIN FAIRLY UNFOCUSED AND POORLY TIMED AT THAT...
AND BEYOND A WAVE WHICH WILL MOVE NORTH OF THE AREA MONDAY NIGHT
INTO TUESDAY...DID NOT SEE A GREAT NEED TO CARRY ANY LOW POPS AT
THIS TIME. RIDGE LOOKS TO GENERALLY REMAIN STRONG BEFORE HEIGHTS
START TO FALL AT VERY END OF THE PERIOD...BUT WITH BOUNDARY PRESSING
SOUTHWARD INTO WARMER AIR ALOFT...KEPT THIS ALSO CLEAR OF RAINFALL
CHANCES FOR THE TIME. EXPECT MAX TEMPS TO REMAIN HOT THROUGH THE
PERIOD...WITH BOUNDARY UNABLE TO MAKE ANY STRONG MOVES SOUTH...
WITH 90S TO AROUND 100 CONTINUING...AND LOWS MAINLY UPPER 60S TO MID
70S. STRETCHED DIURNAL RANGE A BIT FROM GUIDANCE WITH THE VERY DRY
CONDITIONS. /CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...HEAT ADVISORY FROM 1 PM THURSDAY TO 9 PM CDT SATURDAY FOR
SDZ050-052-057>060-063>065-068-069.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
621 PM CDT WED JUL 18 2012
.DISCUSSION.../ISSUED AT 403 PM CDT/
CURRENTLY SEEING CLEARING SKIES IN THE SUBSIDENCE ZONE BEHIND THIS
MORNINGS AND EARLY AFTERNOON CONVECTION. INSTABILITY BEGINNING TO
RECOVER OVER THE CWA...BUT ATMOSPHERE REMAINS STRONGLY CAPPED. FEEL
THIS WILL REMAIN THE CASE THROUGH THE EVENING HOURS OVER MUCH OF THE
AREA. HRRR AND SREF SHOWING SOME REDEVELOPMENT FROM BROOKINGS EAST
INTO SOUTHWEST MINNESOTA THIS EVENING. NOT REALLY MUCH OF ANY
FORCING...OTHER THAN MAYBE SOME WEAK CONVERGENCE. THUS THINK
ANYTHING THAT FORMS IN THIS AREA WILL BE ISOLATED AT BEST. OTHERWISE
WILL SEE CLEARING SKIES AND GENERALLY LIGHT WINDS TONIGHT. COULD SEE
SOME LOW CLOUDS AND OR FOG DEVELOP LATE TONIGHT INTO TOMORROW
MORNING...WITH THE BEST CHANCE ACROSS SOUTHWEST MINNESOTA WHERE
MIXING WAS LEAST TODAY. LOWS TONIGHT WILL BE A BIT
COOLER...GENERALLY UPPER 60S SOUTHWEST MINNESOTA TO LOW 70S ALONG
THE MISSOURI RIVER.
THURSDAY WILL BE ANOTHER HOT DAY OVER THE REGION UNDER MOSTLY SUNNY
SKIES. 850 MB TEMPERATURES LIKELY TO RANGE FROM AROUND 22C IN THE
EAST TO 28C IN THE WEST. EXPECT DEEP MIXING...ESPECIALLY ALONG AND
WEST OF INTERSTATE 29. THIS WILL RESULT IN HIGHS CLOSER TO THE
WARMER MET GUIDANCE...IN THE UPPER 80S TO AROUND 90 SOUTHWEST
MINNESOTA...LOW TO MID 90S IN THE INTERSTATE 29 CORRIDOR...AND
AROUND 100 WEST OF THE JAMES RIVER. DEWPOINTS WILL LIKELY MIX INTO
THE 50S WHERE TEMPERATURES ARE HOTTEST...SO THINKING IS MOST AREAS
GENERALLY REMAIN AT 100 OR BELOW FOR HEAT INDICES. /CHENARD
STRENGTHENING UPPER RIDGE LOOKS TO PROTECT THE AREA FROM PRECIP
THROUGH THE REMAINDER OF THE SHORT TERM...AT LEAST UNTIL SATURDAY
WHEN MAY HEAT ENOUGH TO BREAK AN ISOLATED STORM NEAR THE FRONTAL
BOUNDARY ALONG THE NORTHWEST EDGE OF THE CWA. NOCTURNAL DEVELOPMENT
WILL LIKELY CYCLE NORTH AND EAST OF THE AREA...BUT A COUPLE OF
MODELS TRYING TO DEVELOP SYSTEMS AND DIVE SOUTH SOUTHEAST THROUGH
THE EASTERN HALF OF THE AREA. MIXING OF 850-925 THERMAL FIELDS
KEEP THE 100S IN THE GAME FOR FRIDAY AND ESPECIALLY SATURDAY...
MAINLY WEST OF INTERSTATE 29...AND FORECAST IS ACTUALLY SOMEWHAT
CONSERVATIVE FOR FAR WEST FRIDAY AND WEST OF I29 ON SATURDAY...
HANGING OUT CLOSER TO THE MEAN MIXED NUMBERS BETWEEN NAM/ECMWF.
AGAIN...BIG ISSUE ON POTENTIAL DEGREE OF HEAT HEADLINES WILL BE
DEGREE OF DEWPOINTS AND HOW FAR DOWN THEY MIX...OR HOW MUCH THE
MOISTURE CAN POOL. AT THIS TIME...AGAIN APPEARS THAT WORST OF
POSSIBLE CONDITIONS WILL BE LESSENED BY DEWPOINTS WHICH WILL MIX
INTO THE 50S...WHERE AFTERNOON READINGS REACH NEAR OR ABOVE 100
DEGREES. THE FARTHER EAST LOCATIONS WILL KEEP HANGING ON TO HIGHER
DEWPOINTS...BUT WILL NOT WARM QUITE AS MUCH. CURRENT ISSUANCE OF
HEAT ADVISORY IS DEFINED MORE BY WHERE IS EXPECTED TO TAKE EFFECT ON
THURSDAY. WILL LIKELY NOT BE THE FINAL EVOLUTION...AND EXPECT TO ADD
ON OVER THE NEXT DAY OR TWO AREAS TOWARD THE EAST/SOUTHEAST FOR
CONDITIONS THAT DEVELOP ON FRIDAY THROUGH SUNDAY. NEVERTHELESS...
IT WILL CONTINUE HOT.
FOR THE EXTENDED RANGE /SATURDAY NIGHT THROUGH WEDNESDAY/...
CHANCES FOR RAIN REMAIN FAIRLY UNFOCUSED AND POORLY TIMED AT THAT...
AND BEYOND A WAVE WHICH WILL MOVE NORTH OF THE AREA MONDAY NIGHT
INTO TUESDAY...DID NOT SEE A GREAT NEED TO CARRY ANY LOW POPS AT
THIS TIME. RIDGE LOOKS TO GENERALLY REMAIN STRONG BEFORE HEIGHTS
START TO FALL AT VERY END OF THE PERIOD...BUT WITH BOUNDARY PRESSING
SOUTHWARD INTO WARMER AIR ALOFT...KEPT THIS ALSO CLEAR OF RAINFALL
CHANCES FOR THE TIME. EXPECT MAX TEMPS TO REMAIN HOT THROUGH THE
PERIOD...WITH BOUNDARY UNABLE TO MAKE ANY STRONG MOVES SOUTH...
WITH 90S TO AROUND 100 CONTINUING...AND LOWS MAINLY UPPER 60S TO MID
70S. STRETCHED DIURNAL RANGE A BIT FROM GUIDANCE WITH THE VERY DRY
CONDITIONS. /CHAPMAN
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LIGHT EASTERLY FLOW IS
EXPECTED TO PERSIST ACROSS THE AREA THROUGH THE OVERNIGHT HOURS. AS
BOUNDARY LAYER GROWS ON THURSDAY...MODELS SUGGEST WINDS MAY BECOME
NORTHWESTERLY BUT WOULD REMAIN LIGHT. FOR NOW...WITH WINDS
REMAINING LIGHT DID NOT MAKE A SEPARATE GROUPING FOR POTENTIAL LIGHT
NORTHWESTERLY WINDS TOMORROW AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR
IAZ001-002-012-013- 020-021-031-032.
MN...NONE.
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ013-014.
SD...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR SDZ050-052-053-
057>071.
HEAT ADVISORY FROM 1 PM THURSDAY TO 9 PM CDT SATURDAY FOR SDZ050-
052-057>060-063>065-068-069.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
403 PM CDT WED JUL 18 2012
.DISCUSSION.../ISSUED AT 403 PM CDT/
CURRENTLY SEEING CLEARING SKIES IN THE SUBSIDENCE ZONE BEHIND THIS
MORNINGS AND EARLY AFTERNOON CONVECTION. INSTABILITY BEGINNING TO
RECOVER OVER THE CWA...BUT ATMOSPHERE REMAINS STRONGLY CAPPED. FEEL
THIS WILL REMAIN THE CASE THROUGH THE EVENING HOURS OVER MUCH OF THE
AREA. HRRR AND SREF SHOWING SOME REDEVELOPMENT FROM BROOKINGS EAST
INTO SOUTHWEST MINNESOTA THIS EVENING. NOT REALLY MUCH OF ANY
FORCING...OTHER THAN MAYBE SOME WEAK CONVERGENCE. THUS THINK
ANYTHING THAT FORMS IN THIS AREA WILL BE ISOLATED AT BEST. OTHERWISE
WILL SEE CLEARING SKIES AND GENERALLY LIGHT WINDS TONIGHT. COULD SEE
SOME LOW CLOUDS AND OR FOG DEVELOP LATE TONIGHT INTO TOMORROW
MORNING...WITH THE BEST CHANCE ACROSS SOUTHWEST MINNESOTA WHERE
MIXING WAS LEAST TODAY. LOWS TONIGHT WILL BE A BIT
COOLER...GENERALLY UPPER 60S SOUTHWEST MINNESOTA TO LOW 70S ALONG
THE MISSOURI RIVER.
THURSDAY WILL BE ANOTHER HOT DAY OVER THE REGION UNDER MOSTLY SUNNY
SKIES. 850 MB TEMPERATURES LIKELY TO RANGE FROM AROUND 22C IN THE
EAST TO 28C IN THE WEST. EXPECT DEEP MIXING...ESPECIALLY ALONG AND
WEST OF INTERSTATE 29. THIS WILL RESULT IN HIGHS CLOSER TO THE
WARMER MET GUIDANCE...IN THE UPPER 80S TO AROUND 90 SOUTHWEST
MINNESOTA...LOW TO MID 90S IN THE INTERSTATE 29 CORRIDOR...AND
AROUND 100 WEST OF THE JAMES RIVER. DEWPOINTS WILL LIKELY MIX INTO
THE 50S WHERE TEMPERATURES ARE HOTTEST...SO THINKING IS MOST AREAS
GENERALLY REMAIN AT 100 OR BELOW FOR HEAT INDICES. /CHENARD
STRENGTHENING UPPER RIDGE LOOKS TO PROTECT THE AREA FROM PRECIP
THROUGH THE REMAINDER OF THE SHORT TERM...AT LEAST UNTIL SATURDAY
WHEN MAY HEAT ENOUGH TO BREAK AN ISOLATED STORM NEAR THE FRONTAL
BOUNDARY ALONG THE NORTHWEST EDGE OF THE CWA. NOCTURNAL DEVELOPMENT
WILL LIKELY CYCLE NORTH AND EAST OF THE AREA...BUT A COUPLE OF
MODELS TRYING TO DEVELOP SYSTEMS AND DIVE SOUTH SOUTHEAST THROUGH
THE EASTERN HALF OF THE AREA. MIXING OF 850-925 THERMAL FIELDS
KEEP THE 100S IN THE GAME FOR FRIDAY AND ESPECIALLY SATURDAY...
MAINLY WEST OF INTERSTATE 29...AND FORECAST IS ACTUALLY SOMEWHAT
CONSERVATIVE FOR FAR WEST FRIDAY AND WEST OF I29 ON SATURDAY...
HANGING OUT CLOSER TO THE MEAN MIXED NUMBERS BETWEEN NAM/ECMWF.
AGAIN...BIG ISSUE ON POTENTIAL DEGREE OF HEAT HEADLINES WILL BE
DEGREE OF DEWPOINTS AND HOW FAR DOWN THEY MIX...OR HOW MUCH THE
MOISTURE CAN POOL. AT THIS TIME...AGAIN APPEARS THAT WORST OF
POSSIBLE CONDITIONS WILL BE LESSENED BY DEWPOINTS WHICH WILL MIX
INTO THE 50S...WHERE AFTERNOON READINGS REACH NEAR OR ABOVE 100
DEGREES. THE FARTHER EAST LOCATIONS WILL KEEP HANGING ON TO HIGHER
DEWPOINTS...BUT WILL NOT WARM QUITE AS MUCH. CURRENT ISSUANCE OF
HEAT ADVISORY IS DEFINED MORE BY WHERE IS EXPECTED TO TAKE EFFECT ON
THURSDAY. WILL LIKELY NOT BE THE FINAL EVOLUTION...AND EXPECT TO ADD
ON OVER THE NEXT DAY OR TWO AREAS TOWARD THE EAST/SOUTHEAST FOR
CONDITIONS THAT DEVELOP ON FRIDAY THROUGH SUNDAY. NEVERTHELESS...
IT WILL CONTINUE HOT.
FOR THE EXTENDED RANGE /SATURDAY NIGHT THROUGH WEDNESDAY/...
CHANCES FOR RAIN REMAIN FAIRLY UNFOCUSED AND POORLY TIMED AT THAT...
AND BEYOND A WAVE WHICH WILL MOVE NORTH OF THE AREA MONDAY NIGHT
INTO TUESDAY...DID NOT SEE A GREAT NEED TO CARRY ANY LOW POPS AT
THIS TIME. RIDGE LOOKS TO GENERALLY REMAIN STRONG BEFORE HEIGHTS
START TO FALL AT VERY END OF THE PERIOD...BUT WITH BOUNDARY PRESSING
SOUTHWARD INTO WARMER AIR ALOFT...KEPT THIS ALSO CLEAR OF RAINFALL
CHANCES FOR THE TIME. EXPECT MAX TEMPS TO REMAIN HOT THROUGH THE
PERIOD...WITH BOUNDARY UNABLE TO MAKE ANY STRONG MOVES SOUTH...
WITH 90S TO AROUND 100 CONTINUING...AND LOWS MAINLY UPPER 60S TO MID
70S. STRETCHED DIURNAL RANGE A BIT FROM GUIDANCE WITH THE VERY DRY
CONDITIONS. /CHAPMAN
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 18Z THURSDAY. CURRENTLY
SEEING SCATTERED SHOWERS AND THUNDERSTORMS EAST OF OUR TAF SITES
ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA. EXPECT
THESE TO CONTINUE TO PUSH EAST EARLY THIS AFTERNOON. COULD HAVE A
FEW STORMS REDEVELOP LATER THIS AFTERNOON...BUT THINK BEST CHANCE OF
THIS IS AGAIN EAST OF THE TAF SITES. BOTH MET AND MAV WANT TO
DEVELOP SOME FOG TOMORROW MORNING. GIVEN RAINFALL THIS MORNING
AROUND KHON AND KFSD...CAN NOT COMPLETELY RULE OUT SOME MVFR FOG.
HOWEVER CONFIDENCE IS TOO LOW AT THIS TIME TO MENTION IN THE TAFS.
/CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR
IAZ001-002-012-013- 020-021-031-032.
MN...NONE.
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ013-014.
SD...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR SDZ050-052-053-
057>071.
HEAT ADVISORY FROM 1 PM THURSDAY TO 9 PM CDT SATURDAY FOR SDZ050-
052-057>060-063>065-068-069.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
629 PM CDT WED JUL 18 2012
.AVIATION...
CONTINUED VFR WITH LIGHT SOUTHERLY WINDS. THREAT OF SHRA/TSRA THIS
EVENING HAS DIMINISHED GREATLY AND WILL REMAIN NEAR ZERO THROUGH
THURSDAY AS HIGH PRESSURE ALOFT OVERSPREADS THE REGION.
&&
.PREV DISCUSSION... /ISSUED 318 PM CDT WED JUL 18 2012/
SHORT TERM...
AGAIN...CONSIDERABLE QUESTIONS REMAIN AS TO WHETHER OR NOT
CONVECTION WILL BE ABLE TO DEVELOP ACROSS THE FORECAST AREA OR NOT.
UPPER LOW CONTINUES TO SPIN JUST SOUTHEAST OF THE BIG BEND OVER THE
RIO GRANDE AND THERE REMAINS SOME ENHANCED MOISTURE OVER THE REGION.
MODELS REMAIN ALL OVER THE PLACE WITH TIMING...COVERAGE...AND HOW
LONG STORMS MAY STAY AROUND /IF/ THEY DEVELOP. HRRR HAS BEEN FAIRLY
CONSISTENT WITH DEVELOPING ISOLATED TO SCATTERED STORMS ALONG AND
EAST OF THE CAPROCK WHILE THE NAM AND TTU WRF ARE DRY. CU FIELD ON
VISIBLE SATELLITE IS A BIT MORE EXTENSIVE THAN THIS TIME YESTERDAY
BUT TAKING A LOOK OUTSIDE SHOWS LITTLE VERTICAL EXTENT FOR NOW.
RADAR IS SHOWING SOME RETURNS ACROSS THE SOUTHWESTERN TEXAS
PANHANDLE INTO EASTERN NEW MEXICO BUT EVEN THESE ARE DISSIPATING
FAIRLY FAST. WILL KEEP THE FORECAST DRY FOR TONIGHT BUT WILL NEED
TO WATCH THROUGH THE LATE AFTERNOON INTO THE EVENING. TEMPERATURES
WILL BE FAIRLY SIMILAR TO TODAY AND THIS MORNING FOR HIGHS AND LOWS
TOMORROW RESPECTIVELY.
JORDAN
LONG TERM...
UA RIDGE ACROSS COLORADO WILL AMPLIFY AND SHIFT NE TO ACROSS THE
CENTRAL PLAINS ON FRIDAY...AND PERSIST THERE THROUGH THE WEEKEND.
THE MONSOONAL MOISTURE WILL GET NUDGED WEST TO CENTRAL/WESTERN NEW
MEXICO. LARGE SCALE SUBSIDENCE WILL MITIGATE STORM POTENTIAL AND
SLOWLY INCREASING THICKNESS VALUES WILL PROMOTE WARMING TEMPS /UPPER
90S ON THE CAPROCK TO LOWER TRIPLE DIGITS OFF THE CAPROCK/. WILL
NEED TO KEEP AN EYE ON A WEAKNESS/UA IMPULSE ROUNDING THE SOUTHERN
PERIPHERY OF THE SAID RIDGE...AND MOVING ACROSS THE SOUTHERN
PLAINS FRIDAY EVENING/NIGHT. THUS FAR...FORECAST MODELS ARE VOID
OF PRECIP GIVEN A MID LEVEL CAPPING INVERSION AND THIS IMPULSE
APPEARING RELATIVELY WEAK. EARLY NEXT WEEK...BOTH THE GFS AND
ECMWF HINT AT A PACIFIC UA LOW PROPAGATING ENE ACROSS NORTHERN
IDAHO/SOUTHERN ALBERTA. THIS WILL ENCOURAGE THE CENTER OF THE UA
RIDGE TO TRANSLATE SE TO THE SERN CONUS...WHERE IT IS PROGGED TO
REMAIN THROUGH MID-WEEK. AS A RESULT...THE MONSOONAL MOISTURE
PLUME MAY HAVE THE OPPORTUNITY TO NEAR THE WESTERN ZONES.
CONCURRENTLY...AN EASTERLY WAVE IS SHOWN TO MOVE ACROSS THE THE FA
TUESDAY. THE GFS AND ECMWF SOLUTIONS EXHIBIT RATHER LIGHT QPF JUST
EAST AND SE OF THE CWA. WILL NEED TO ANALYZE FUTURE MODEL RUNS TO
SEE IF THIS WAVE WILL TURN OUT TO BE EVEN STRONGER THAN CURRENTLY
INDICATED...AND THUS CREATE CHANCES FOR PRECIP. ATTM...A SILENT
POP FORECAST WILL ENSUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 94 66 93 67 / 10 0 0 10 10
TULIA 66 94 67 95 68 / 10 0 0 10 10
PLAINVIEW 66 94 68 94 69 / 10 0 0 10 10
LEVELLAND 66 93 66 94 69 / 10 0 0 10 10
LUBBOCK 70 94 68 96 70 / 10 0 0 10 10
DENVER CITY 67 91 66 94 68 / 10 0 0 10 10
BROWNFIELD 67 92 67 95 69 / 10 0 0 10 10
CHILDRESS 71 100 73 101 73 / 10 0 0 10 10
SPUR 70 96 71 98 72 / 10 0 0 10 10
ASPERMONT 73 98 74 101 74 / 10 0 0 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
336 PM CDT TUE JUL 17 2012
.SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
&&
.LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 20 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 20 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 20 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 20 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/29
AREA FORECAST DISCUSSION
NWS SPOKANE WA
231 PM PDT Tue Jul 17 2012
.SYNOPSIS...
An unusually strong and moist upper level low will continue to
dominate our weather through Thursday. The presence of this low
will equate to localized showers and thunderstorms each day with
heavy rain at times. Another strong upper level low is expected
to move into the region via the Gulf of Alaska Thursday night and
Friday and will bring a better chance of thunderstorms. The
possibility showers and thunderstorms will remain over the
northern mountains through the weekend...otherwise the forecast
will be dry.
&&
.DISCUSSION...
Tonight...A large closed low will remain along the Northern
California coast with southerly flow ahead of this low over the
Inland Northwest. The wave that brought thunderstorms to the
region Monday night and Tuesday will continue to pull away from
the area into Southern British Columbia through the evening.
Another wave over Oregon will weaken as it moves north into
Washington this evening. Net result for tonight should be much
less lightning activity compared to last night. However there is
plenty of instability this afternoon with surface based CAPES as
of 1 pm per LAPS data of 1500-2000 J/KG. A lack of forcing and a
weak cap has limited thunderstorm activity south of Highway 2
today but some cells are developing across Northeast Oregon, the
Blues, and Camas Prairie this afternoon that will be tracking
north tonight. These may weaken when coming off the higher terrain
but potential also exists for an outflow boundary to tap into the
strong instability for thunderstorms propogating north from the
Blues into the Palouse, Lewiston area, Upper Columbia Basin,
Spokane, and Coeur D`Alene areas. HRRR which has been handling the
convection reasonably well today suggests a better potential for
storms to come off the mountains and impact Pullman and Lewiston
so will indicate better thunder chances here and only slight
chance mention from Moses Lake to Spokane. This activity will
weaken after sunset although a lingering area of mid level
instability could trigger a stray thunderstorm overnight from the
Blues to the Central Panhandle Mountains. A secondary weak wave
with less instability will track across Southern BC overnight
which could bring a few showers to areas near the Canadian border.
Also with very moist low levels and a trend towards clearing skies
overnight will likely see some patchy fog in the northern valleys
as well as the Idaho Panhandle valleys. JW
Wednesday through Friday Evening...The models are actually in
pretty good agreement after showing numerous solution changes
over the past 2-3 days. The closed low that has been cut-off from
any steering flow will remain nearly stationary through Thursday.
Meanwhile the first upper level trough that was thought to nudge
the closed low out of the region will track meekly through
northern BC. A secondary low currently near the Aleutian chain
will track into the Gulf of Alaska. This low is progged by the
models to gain strength and result in the closed low getting
ejected northeast through the Pacific Northwest late Thursday
night and Friday. There are still some minor timing issues, but
this is the second run in a row for the majority of the models to
show this solution.
Wednesday through Thursday...As mentioned above the closed low
will continue to remain nearly stationary along the southwest
Oregon coast. Pacific moisture will continue to wrap around the
low and move into the Inland Northwest. The atmosphere will
remain unstable, however the difference from the past few days is
there will not be any robust short wave disturbances moving
through the region. Therefore convection for the area will rely on
surface based heating and orographics for shower and thunderstorm
initiation. So while showers and Thunderstorms are expected, they
should not be as widespread and should not be as active. Meanwhile
the models are indicating the passage of the closed low will hold
off 24 hours until Friday. Therefore temperatures for Thursday
have been increased with highs remaining warmer then normals.
Thursday night through Friday evening. The stronger secondary
upper level low is now progged by the models to begin pushing the
closed low inland Thursday night and Friday. There will be
abundant moisture to work with as PW`s will be well above an inch
which is 150-180 percent of normal. The trough becomes negatively
tilted through the night. This pattern is good for very active
thunderstorms and there is no reason not to think this will happen Thursday
night ad Friday. Instability parameters and 0-6km wind shear will
definitely be in place and the kicker will be provided by a mid-
level cold front that tracks from near the Washington/Oregon
Cascades at 06z Friday and is mainly east of the the forecast area
by Friday afternoon. Nocturnal thunderstorms tend to be high
based with gusty outflow winds and the chance of medium to large
hail. This should be case again Thursday and Friday, however
because of the amounts of moisture expected locally heavy rain will
result in localized urban and small stream flooding. Debris flows
will also be possible. /Tobin
Friday night through Tuesday: An upper level low pressure system
that kicks out the cut off low over the region for Friday will
make its way across British Columbia through this period. There
is some question how far south this low will actually get amongst
the latest 00Z model runs. The GFS keeps the low north of the
region; the Canadian is much further south with the center of the
low tracking right across eastern WA; and the ECMWF is right in
the middle, but is the strongest of the three. How far south this
low actually tracks will determine how much precipitation we get,
if any.
The Canadian model does not track this low very well and
actually retrogrades it a bit Monday into Tuesday. This idea does
not make any sense, especially since this low pressure system is
not expected to be cut off from the Polar Jet stream unlike the
past systems we have been experiencing. Thus, the Canadian run was
thrown out of my decision making process. The GEFS ensemble mean
is a nice compromise between the 00Z GFS and ECMWF operational
runs. This would swing the low pressure system through the region
Sunday afternoon through Monday afternoon. Kept a mention of a
slight chance of showers across the northern mountains. We could
see some thunderstorms, but it looks like the best instability
will remain to our north where British Columbia will have the best
shot at thunderstorms. This low will draw up some monsoonal
moisture from the south as well, but this moisture looks as if it will
remain to our south. However, we may see some showers and
thunderstorms that could track southwest to northeast from the
Northeast Blue Mountains into the Central Panhandle. Confidence is
too low to mention showers or thunderstorms across these areas at
this time. If this low decides to track even further south, then
temperatures will need to be lowered even more, but for now went
with temperatures near normal through Monday.
The general long wave trend after Monday continues to indicate that
there will be very little movement of the strong ridge of higher
pressure over the central United States and over the eastern
Pacific. This will allow the possibility for more weather systems
to dive southward over the eastern Pacific high down into the Pac
NW. At this time, I don`t see any other strong low pressure
systems that will track into the region after Monday. This should
result in more of a zonal flow pattern over the Northwest. It
looks like we will be lacking moisture, which should result in a
fairly dry forecast after Monday. We should see temperatures warming a
bit with highs slight above average for Tuesday. /SVH
&&
.AVIATION...
18Z TAFS: A band of showers and thunderstorms north of the
Columbia Basin will impact KOMK and KCQV through the afternoon as
a slow moving wave continues to track north. Elsewhere
thunderstorms will likely develop 20-22z over the Blue Mountains
and track north towards KPUW/KLWS and used VCTS to account for
possible thunderstorms at these terminals. These storms may
survive the trip north to KGEG-KSFF-KCOE but confidence is lower
of storms impacting these sites with the main threat being from
00z-04z. This activity should wind down after 04z as the lower
atmosphere stabilizes with the loss of day time heating. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 87 62 89 62 82 / 20 20 20 30 30 50
Coeur d`Alene 61 86 59 89 60 80 / 20 20 20 30 30 60
Pullman 58 86 56 86 58 81 / 40 20 20 30 30 20
Lewiston 67 94 65 95 68 91 / 40 30 30 30 30 20
Colville 60 90 59 90 58 85 / 30 20 30 30 30 60
Sandpoint 58 85 56 89 55 79 / 20 20 20 30 30 60
Kellogg 60 85 57 90 57 82 / 20 20 20 30 30 60
Moses Lake 64 93 62 93 63 89 / 20 20 10 20 30 50
Wenatchee 68 92 65 94 65 88 / 20 20 10 20 40 40
Omak 64 94 62 95 62 88 / 30 20 10 20 40 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1129 AM PDT Tue Jul 17 2012
.SYNOPSIS...
An unusually strong and moist upper level low will continue to
dominate our weather through midweek. The presence of this low
will equate to more showers and thunderstorms each day with
localized flooding possible. Yet another strong upper level low is
expected to move into the region via the Gulf of Alaska late week
or weekend. This will bring a renewed threat of thunderstorms.
&&
.DISCUSSION...
Radar imagery as of 11 am indicated a west-east band of showers
and thunderstorms stretching from Omak through Chewelah and
Sandpoint. With this band slowly moving through pops remain high
through the afternoon north of Highway 2. Cloud cover and
precipitation will also keep temperatures cooler than previously
thought so high temperatures were lowered for this afternoon. South
of Highway 2 increased sun breaks will aid in destabilizing the
atmosphere this afternoon. However with no strong wave to initate
convection thunderstorms may have a hard time making it off the
mountains. The latest HRRR suggests thunderstorms developing over
the Blues, Camas Prairie, and Central Panhandle Mountains early
this afternoon but dissipating after coming off the mountains.
With LAPS data indicating surface based CAPES of around 1000 J/KG
and with potential outflow winds from thunderstorms acting as a
forcing mechanism for convection to develop in the lower elevations,
will not completely remove pops for the rest of today in places
like Ritzville, Pullman, and Spokane. Pullman and Lewiston areas
may have a better chance this afternoon given closer proximity to
where convection is expected to initiate. With convection over the
Blues unlikely to make it as far north as Spokane/Coeur D`Alene
areas this afternoon pops were trimmed down quite a bit. These
areas may have a better chance in the evening depending on how
much thunderstorm activity can make it off the mountains. JW
&&
.AVIATION...
18Z TAFS: A band of showers and thunderstorms north of the
Columbia Basin will impact KOMK and KCQV through the afternoon as
a slow moving wave continues to track north. Elsewhere
thunderstorms will likely develop 20-22z over the Blue Mountains
and track north towards KPUW/KLWS and used VCTS to account for
possible thunderstorms at these terminals. These storms may
survive the trip north to KGEG-KSFF-KCOE but confidence is lower
of storms impacting these sites with the main threat being from
00z-04z. This activity should wind down after 04z as the lower
atmosphere stabilizes with the loss of day time heating. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 84 65 83 60 80 59 / 20 30 20 20 30 30
Coeur d`Alene 84 62 82 58 79 57 / 20 40 20 20 40 30
Pullman 85 60 81 55 79 56 / 30 30 20 20 40 30
Lewiston 94 68 90 64 89 66 / 30 30 30 30 40 30
Colville 82 61 86 59 80 55 / 70 50 20 30 40 30
Sandpoint 79 59 81 56 76 52 / 70 50 20 20 40 30
Kellogg 81 59 81 56 78 55 / 30 40 20 20 40 30
Moses Lake 92 65 88 61 85 60 / 10 30 20 10 20 30
Wenatchee 90 69 88 63 84 62 / 20 30 20 10 20 40
Omak 80 66 90 60 82 58 / 90 30 20 10 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
638 PM CDT WED JUL 18 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COMPLICATED
SYNOPTIC PATTERN ACROSS THE REGION AT THE MOMENT. FIRST
OFF...REMNANT MCV CONTINUES TO WEAKEN AS IT MOVES NORTHEAST OVER
NORTHWEST WISCONSIN. CAN STILL EXPECT AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS NORTH-CENTRAL AND FAR NORTHEAST
WISCONSIN THROUGH LATE AFTERNOON. PERHAPS A BIGGER CONCERN WILL BE
A DEVELOPING CLUSTER OF SHOWERS AND STORMS OVER SOUTHERN MINNESOTA
AND NORTHERN IOWA THAT IS TRACKING NORTHEAST AS WELL. THIS CLUSTER
IS ALSO GETTING THAT MCV LOOK TO IT AND ITS TRACKING IN THE SAME
TRAJECTORY AS THE MCV FARTHER NORTH. THE LATEST TIMING WOULD CALL
FOR THIS NEXT CLUSTER OF STORMS TO MOVE INTO CENTRAL WISCONSIN
AROUND 00Z. OTHERWISE...THE 850MB BAROCLINIC ZONE REMAINS IN PLACE
FROM NW WISCONSIN TO AROUND KEWAUNEE THIS AFTERNOON. AS SHORTWAVE
ENERGY OVER THE PLAINS INTERACTS WITH THIS THERMAL
GRADIENT...THUNDERSTORM CHANCES AND SEVERITY ARE THE MAIN FORECAST
CONCERNS IN THE SHORT TERM.
TONIGHT...MODELS DO NOT HAVE THE CURRENT WEATHER HANDLED VERY
WELL...SO COULDNT REALLY RELY ON ANY PARTICULAR GUIDANCE. MCV
MOVING OVER NORTHWEST WISCONSIN IS PUTTING A MONKEY WRENCH INTO THE
PLANS...THOUGH THINK IT WILL CONTINUE TO GRADUALLY WEAKEN AS IT
MOVES EAST. WHAT IMPACT THIS MCV WILL HAVE ON THUNDERSTORM
DEVELOPMENT FOR TONIGHT IS NOT CLEAR. IT MAY NOT HAVE MUCH IMPACT
ASSUMING THE STRENGTHENING TRENDS OF THE THUNDERSTORM CLUSTER OVER
SOUTHERN MINNESOTA CONTINUE. AS MENTIONED EARLIER...THIS
THUNDERSTORM COMPLEX WILL ARRIVE EARLY THIS EVENING OVER CENTRAL
WISCONSIN BEFORE TRACKING OVER THE FOX VALLEY AND NE WISCONSIN LATER
IN THE EVENING ASSUMING ITS DIRECTION OF TRAVEL DOES NOT CHANGE. IT WILL
ENCOUNTER ELEVATED CAPES TONIGHT FROM ABOUT 500-800 J/KG SO CANNOT
RULE OUT A STORM BECOMING FEISTY AND PRODUCING NEAR SEVERE
WEATHER...BUT ODDS OF ANYTHING SEVERE HAPPENING IS LOW. HEAVY RAIN
LOOKS TO BE THE MAIN THREAT AND 1 TO 2 INCHES OF RAIN APPEARS POSSIBLE.
HAVE BROAD BRUSHED POPS FOR THE 12 HOUR PERIOD TONIGHT AND HAVE
INCREASED THEM TO LIKELY. WITH THE EXPECTED CLOUD COVER AND
STORMS...RAISED LOWS A COUPLE DEGREES.
THURSDAY...THE SHORTWAVE TROUGH WILL PASS ACROSS THE FORECAST AREA
DURING THE MORNING AND HELP PUSH THE 850MB BAROCLINIC ZONE TO THE
SOUTH BY MIDDAY. WITH CONVERGENCE WEAKENING DURING THE AM
HOURS...WILL KEEP POPS LOW TOMORROW MORNING THEN CLEAR THEM OUT FOR
THE AFTERNOON. PLENTY OF MORNING CLOUD COVER...PLUS LINGERING LOW
LEVEL MOISTURE IN COOL EAST FLOW...SHOULD KEEP TEMPERATURES DOWN
AND WILL SHOW HIGHS IN THE MIDDLE TO UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...PCPN TRENDS
AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
WEAK HIGH PRESSURE WILL MOVE THROUGH THE AREA ON THURSDAY NIGHT
AND FRIDAY. A FEW MODELS GENERATE SOME LGT PCPN ACROSS NC WI ON
FRIDAY...DUE TO WAA/ISENT LIFT...INCREASING MOISTURE CONVERGENCE
AND ELEVATED INSTABILITY. CURRENT THINKING IS THAT THIS PCPN WILL
STAY NW OF GRB CWA THROUGH FRIDAY.
A COLD FRONT WILL WORK ITS WAY INTO NORTHERN WI ON FRIDAY NIGHT...
THEN GRADUALLY SAG SOUTH ACROSS THE FORECAST AREA OVER THE WEEKEND.
THIS FRONT SHOULD BE THE FOCUS FOR ISOLD/SCT TSTM DEVELOPMENT.
ALTHOUGH IT IS FAR FROM A CERTAINTY...MODELS ARE SUGGESTING THAT
THE FRONT MAY SAG FAR ENOUGH SOUTH ON MONDAY/MONDAY NIGHT TO ALLOW
WEAK HIGH PRESSURE TO SETTLE INTO NE WI. WILL TAKE A CHANCE ON A
DRY FCST FOR THOSE PERIODS FOR NOW.
LOW PRESSURE EXPECTED TO MOVE ACROSS SOUTHERN CANADA DURING THE
MIDWEEK PERIOD...WITH A COLD FRONT APPROACHING FROM THE NORTHERN
PLAINS. SW FLOW IN ADVANCE OF THE FRONT WILL LIFT THE OLD FRONT
BACK TO NORTH AS A WARM FRONT...BRINGING A SURGE OF WARMER AND
MORE UNSTABLE AIR INTO C/NE WI. WOULD NOT BE SURPRISED IF WE
SEE A PERIOD OR TWO OF ORGANIZED SEVERE WX LATER TUESDAY INTO
WEDNESDAY...AS INCREASING DEEP LAYER SHEAR COMBINES WITH THE
BUILDING INSTABILITY.
TEMPERATURES WILL REMAIN ABOVE NORMAL IN THE 80S TO AROUND 90
DURING THE PERIOD...AS H8 TEMPS STAY IN THE UPPER TEENS TO AROUND
20 C RANGE. WARMER H8 TEMPS ARE POSSIBLY BY NEXT WEDS...BUT TEMPS
MAY HELD BACK SOMEWHAT BY CONVECTION.
&&
.AVIATION...A STRONG UPPER LEVEL DISTURBANCE WILL PRODUCE SHOWERS
AND THUNDERSTORMS AS IT MOVES ACROSS THE REGION OVERNIGHT AND
EARLY THURSDAY. CIGS AND VSBYS WILL LOWER FROM VFR IN MOST AREAS
THIS EVENING TO IFR OR MVFR OVERNIGHT AND CONTINUING THROUGH
MIDDAY THURSDAY. VFR EXPECTED THURSDAY AFTERNOON.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
332 PM CDT TUE JUL 17 2012
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE SURFACE
COLD FRONT STRETCHING FROM ABOUT WISCONSIN RAPIDS TO APPLETON TO
KEWAUNEE EARLY THIS AFTERNOON. ELEVATED CONVECTION MOVED INTO N-C
WISCONSIN THIS MORNING IN A REGION OF UPPER DIVERGENCE...MID-LEVEL
FGEN...AND POSSIBLY AHEAD OF A WEAK MCV. ADDITIONAL CONVECTION HAS
JUST RECENTLY DEVELOPMENT IN THE WARM SECTOR OVER CENTRAL AND
EAST-CENTRAL WISCONSIN AND WILL NEED TO WATCH THIS AREA FOR SEVERE
DEVELOPMENT. WITH ML CAPES APPROACHING 2000 J/KG...INHIBITION HAS
BEEN ERODING THIS AFTERNOON AND THINK AN ISOLATED SEVERE STORM
REMAINS POSSIBLE GENERALLY SOUTH OF A MARSHFIELD TO GREEN BAY LINE.
THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. PRECIP
TRENDS THROUGH TONIGHT ARE THE MAIN FORECAST CONCERNS.
TONIGHT...AS THE UPPER FLOW VEERS TO THE NORTHWEST...THE SURFACE
COLD FRONT WILL GET DRIVEN SOUTH FROM CENTRAL WISCONSIN TO NORTHERN
ILLINOIS. THE 850MB FRONT WILL NOT BE SO QUICK AND WILL LINGER
ALONG THE ROUTE 29 CORRIDOR THROUGH THE EVENING BEFORE SHIFTING TO
THE SOUTH. THOUGH UPPER DIVERGENCE PULLS OUT BY THIS
EVENING...850-700MB FGEN WILL LINGER ALONG THE FRONTAL SLOPE AND
THEN PUSH SOUTH LATE TONIGHT. ANY SURFACE BASED STORMS WILL BE
MOVING SOUTH OF THE FORECAST AREA EARLY THIS EVENING...BUT THE
CONVERGENT FLOW AND MID-LEVEL FGEN WILL KEEP SCATTERED POTENTIAL OF
SHOWERS AND STORMS GOING THROUGH THE NIGHT OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. DO THINK STORM COVERAGE AND INTENSITY WILL
DIMINISH WITH LOSS OF HEATING...SO THE POSSIBILITY OF SEVERE
CONVECTION MAY ONLY OCCUR UNTIL EARLY THIS EVENING. COOLER AND
DRIER AIR WILL BE ARRIVING BEHIND THE FRONT AND TEMPS WILL BE
FALLING INTO THE LOWER 50S NORTH TO MID 60S SOUTH.
WEDNESDAY...A SLIGHT CHANCE OF SHOWERS WILL LINGER ACROSS CENTRAL
WISCONSIN AND THE SOUTHERN FOX VALLEY IN THE MORNING...BUT ELEVATED
CONVERGENCE HAS WEAKENED ENOUGH BY THIS TIME THAT DO NOT THINK THERE
WILL BE MANY ECHOES AROUND. AS A RESULT...WENT DRY FOR THE
AFTERNOON. NORTHERN AND NORTHEAST WISCONSIN WILL ENJOY A COOLER AND
LESS HUMID DAY UNDER PARTLY TO MOSTLY SUNNY CONDITIONS...WITH HIGHS
RANGING FROM THE UPPER 70S TO MID 80S. A FEW UPPER 80S WILL STILL
BE POSSIBLE OVER CENTRAL WISCONSIN.
.LONG TERM...WED NGT THRU NXT TUE. THE LARGE SCALE PATTERN IS
EXPECTED TO CONSIST OF A STRONG/PERSISTENT UPR RDG ALOFT OVER THE
CNTRL ROCKIES/CNTRL PLAINS AND AN UPR TROF OVER THE ERN CONUS.
BIGGEST FCST ISSUE REMAINS THE HANDLING OF SHORTWAVE TROFS MOVING
FROM THE NE PACIFIC...THRU SRN CANADA...THEN DROPPING SE INTO THE
ERN UPR TROF. EACH OF THESE SHORTWAVE TROFS WL BE ACCOMPANIED BY A
WEAK CDFNT WHICH ARE FCST TO DROP INTO WI AND EVENTUALLY STALL AS
THEY ENCOUNTER THE UPR RDG. ANY PCPN CHCS WL BE TIED TO THESE
CDFNTS...BUT AT LEAST WE WL HAVE A COUPLE CHCS FOR PCPN IN THE
EXTENDED PERIOD. TEMPS WL REMAIN ABOVE NORMAL UNTIL FURTHERN
NOTICE.
WHILE THE SFC BOUNDARY REMAINS QUASI-STNRY ACROSS CNTRL IA/NRN IL
WED NGT...THE 8H BOUNDARY TO SIT ACROSS SRN WI WITH A TIGHT
BAROCLINIC ZONE IN THE VCNTY OF THE 8H BOUNDARY. A SHORTWAVE TROF
IS FCST TO MOVE INTO THE WRN GREAT LKS BRINGING MODEST LEVELS OF
FRONTOGENETICAL FORCING INTO THE SRN HALF OF WI. BEST CONVERGENCE
SHOULD BE OVER SRN WI AS WELL...BUT CLOSE ENUF TO WARRANT CHC POPS
OVER CNTRL/E-CNTRL WI. NRN WI APPEARS TO BE TOO FAR AWAY FROM THE
PRIMARY FORCING/LIFT...THUS WL ONLY MENTION SLGT CHC POPS FOR THE
FAR NORTH.
PCPN CHCS ACROSS CNTRL/E-CNTRL WI SHOULD GRADUALLY DIMINISH THU
MORNING AS THE SHORTWAVE TROF BEGINS TO PULL AWAY FROM THE REGION.
A WEAK AREA OF HI PRES IS THEN SET TO BUILD SOUTH INTO THE NRN/WRN
GREAT LKS THU AFTERNOON AND BRING SOME MIXED SUNSHINE BACK TO NE
WI. MAX TEMPS ARE EXPECTED TO BE CLOSE TO SEASONAL NORMALS WITH
PLENTY OF LOCATIONS REACHING THE 80 TO 85 DEG RANGE (COOLER
LAKESIDE).
AS THE HI PRES SETTLES OVER THE REGION THU NGT...QUIET AND MORE
COMFORTABLE CONDITIONS WL EXIST AS COOLER/DRIER AIR FILTERS INTO
NE WI. UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS...THU NGT APPEARS
TO BE THE COOLEST NGT OF THE EXTENDED PERIOD WITH READINGS DIPPING
INTO THE LWR 50S NORTH...AROUND 60 DEGS E-CNTRL WI. NE WI TO STILL
RESIDE IN A NW FLOW ALOFT THRU FRI WITH THE BACK EDGE OF HI PRES
REACHING INTO WI. CLOCKWISE CIRCULATION AROUND THE SFC HI WL BRING
SOME COOLING TO THE LAKESHORE ON E-SE WINDS. THE REST OF THE FCST
AREA TO SEE MORE OF A S-SE WIND AND WITH PLENTY OF SUNSHINE
ANTICIPATED...TEMPS WL BEGIN TO GET WARM ONCE AGAIN AS READINGS
REACH THE MID TO UPR 80S.
ATTENTION TURNS TO OUR NORTH AND WEST FRI NGT WHERE A CDFNT WL
ATTEMPT TO PUSH SE INTO THE WRN GREAT LKS. AS HAS BEEN THE CASE OF
LATE...ANY CDFNT HAS BEEN A SLOW MOVER AND THIS LATEST ONE IS NO
DIFFERENT. LATEST MDL TIMING HAS THIS FNT ONLY REACHING NRN
SECTIONS OF THE GREAT LKS BY SAT AFTERNOON...THUS HAVE MAINTAINED
A DRY FRI NGT AND ONLY A MINIMAL POP FOR THE NORTH ON SAT. A MORE
PREVAILING S-SW WIND WL BRING WARMER/MORE HUMID AIR MASS INTO WI
WITH MAX TEMPS ON SAT AGAIN FLIRTING WITH 90 DEGS AND DEW POINTS
IN THE MID 60S. THE SLOW NATURE OF THIS CDFNT IS EVIDENT AS THE
MDLS NOW DO NOT BRING THE BOUNDARY INTO NRN WI UNTIL SUNDAY. BROAD
LOW-LEVEL WAA COUPLED WITH INCREASING INSTABILITY (CAPES BETWEEN
1K AND 2K J/KG/LI`S AROUND -4)...PLENTY OF MOISTURE (DEW POINTS
IN THE MID TO UPR 60S) AND THE FNT ITSELF SHOULD BE ABLE TO
GENERATE AT LEAST A CHC FOR SHWRS/TSTMS ESPECIALLY OVER THE NORTH.
TEMPS FOR SUNDAY MAY BE TRICKY DEPENDING ON THE AMOUNT OF CLOUD
COVER/EXTENT OF ANY PCPN...BUT DUE TO THE EXPECTED WARM START TO
THE DAY...ANOTHER VERY WARM DAY ON TAP WITH PLENTY OF UPR 80S TO
LWR 90S OVER THE REGION.
THE CDFNT IS PROGGED TO SLOWLY SAG THRU CNTRL/E-CNTRL WI SUNDAY
NGT...BUT WITH THE LOSS OF DAYTIME HEATING...THE SHWR/TSTM
ACTIVITY MAY BECOME MORE WIDELY SCATTERED WITH TIME. ANY PCPN CHCS
FOR MON WL BE FOCUSED OVER THE SRN HALF OF WI AS THE FNT GRINDS TO
A HALT AS IT HITS THE UPR RDG. TEMPS ARE FCST TO BE A BIT COOLER
BY MON WITH LOWER DEW POINTS OVER THE NORTH AS DRIER AIR TRIES TO
PUSH INTO THE AREA. WINDS ARE FCST TO BACK SW ONCE AGAIN BY NXT
TUE AHEAD OF THE NXT CDFNT WHICH IS EXPECTED TO MOVE ACROSS THE
UPR MS VALLEY. BETTER UPR SUPPORT TO BE SITUATED WELL TO OUR NORTH
WHERE A PROMINENT SHORTWAVE TROF TO BE SITUATED. NEVERTHELESS...MAY
NEED TO CARRY SOME SORT OF POP ACROSS PORTIONS OF THE FCST AREA TO
ACCOUNT FOR INCREASING LOW-LEVEL WAA/INSTABILITY PARAMETERS.
&&
.AVIATION...MVFR CIGS WILL CONTINUE TO SPREAD SOUTHWARD OVER
NORTHERN WISCONSIN AS A COLD FRONT DROPS SOUTH OVER THE STATE. THE
LATEST TRENDS SUPPORT THESE MVFR CIGS MOVING INTO CENTRAL WISCONSIN
THOUGH THINK DOWNSLOPING WILL KEEP THESE CIGS VFR OVER THE FOX
VALLEY. COVERAGE OF SHOWERS AND STORMS ARE TRENDING HIGHER ACROSS
THE ENTIRE AREA THIS AFTERNOON INTO THIS EVENING AS THIS COLD FRONT
MOVES SOUTH. HAVE ADDED TEMPO GROUPS TO ACCOUNT FOR THIS. DRIER
AIR OVER LAKE SUPERIOR WILL MOVE SOUTH BEHIND THE FRONT TONIGHT AND
WILL HELP SKIES CLEAR OVER NORTHERN AND NORTHEAST WISCONSIN. SOME
POTENTIAL FOR SHOWERS...STORMS AND MVFR CIGS REMAINING OVER CENTRAL
AND EVEN EAST-CENTRAL WISCONSIN AS MOISTURE LINGERS BEHIND THE
FRONT. CLEARING SKIES SHOULD OCCUR EVERYWHERE LATE TONIGHT INTO
WEDNESDAY MORNING.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR WIZ037-045-048.
&&
$$
MPC/KALLAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
248 PM CDT TUE JUL 17 2012
.SHORT TERM...THROUGH THURSDAY NIGHT
248 PM CDT TUE JUL 17 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT ACROSS SOUTHERN
MINNESOTA INTO CENTRAL WISCONSIN. REGIONAL RADARS INDICATE STORMS
HAVE DEVELOPED NORTH OF THE FRONT ACROSS WISCONSIN.
THE CONVECTION ACROSS WISCONSIN HAS DEVELOPED IN RESPONSE TO A
WEAK SHORT WAVE TROUGH THAT DEVELOPED OUT OF THE STORMS OVER THE
DAKOTAS LAST NIGHT. THIS IS ALSO BEING AIDED BY THE RIGHT ENTRACE
REGION OF THE UPPER LEVEL JET OVER LAKE SUPERIOR. THE BEST CAPE
EXISTS ALONG AND AHEAD OF THE FRONT WITH AN AXIS OF 2500 J/KG OF
ML CAPE FROM CENTRAL INTO EAST CENTRAL WISCONSIN. AS THE WAVE
MOVES EAST THIS AFTERNOON...WOULD EXPECT THE CONVECTION TO
GRADUALLY SINK TO THE SOUTHEAST TOWARD THE HIGHER CAPE BUT MOST
SHOULD REMAIN BEHIND THE FRONT WHERE THERE IS NO CAP IN PLACE. THE
17.12Z HI-RES ARW AND 17.15Z HRRR SHOW THIS TREND OCCURRING WITH
THE BEST CHANCE OF ANYTHING CLIPPING THE AREA IN THE I94 CORRIDOR.
AFTER THIS EVENING THROUGH WEDNESDAY...ANY ACTIVITY THAT DEVELOPS
WILL BE CLOSELY TIED TO THE POSITION OF THE FRONT. THE 17.12Z
MODELS ALL HAVE DIFFERENT SOLUTIONS ON HOW FAR SOUTH THE FRONT
WILL GET BEFORE STALLING OUT. THE NAM AND GFS TAKE THE FRONT INTO
CENTRAL IOWA AND NORTHERN ILLINOIS TONIGHT WHILE THE 17.00Z ECMWF
HAS THE FRONT FROM NORTHERN IOWA ALONG THE WISCONSIN/ILLINOIS
BORDER. ALL THE MODELS SHOW JUST A SLOW SOUTHWARD DRIFT TO THE
FRONT WEDNESDAY. AT THIS POINT...NOT EXPECTING ANY SHORT WAVE
TROUGHS TO INTERACT WITH THE FRONT...BUT THAT COULD CHANGE IF
CONVECTION DEVELOPS OVER THE HIGH PLAINS TUESDAY NIGHT.
THE MODELS THEN DO SHOW A SHORT WAVE TROUGH COMING OUT OF THE FLOW
OVER THE ROCKIES AND TOPPING THE UPPER LEVEL RIDGE AND MOVING
ACROSS MINNESOTA AND WISCONSIN. AGAIN...THE POSITION OF THE FRONT
WILL HAVE A BIG IMPACT ON WHERE ANY CONVECTION MAY DEVELOP. WOULD
BE MORE ENTHUSED ABOUT THE RAIN CHANCES WITH THIS WAVE IF THERE
WAS ANY MOISTURE TRANSPORT OF SIGNIFIGANCE WITH THE WAVE. WITH THE
LACK OF RETURNING MOISTURE AND ANECEDENT DRY CONDTIONS...HAVE HELD
THE RAIN CHANCES FOR WEDNESDAY NIGHT AROUND 40 PERCENT. AS THIS
WAVE THEN EXITS OFF TO THE EAST THURSDAY...EXPECT THE RAIN TO MOVE
EAST AS WELL DURING THE DAY WITH A DRY THURSDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NORTH.
.LONG TERM...FRIDAY THROUGH TUESDAY
248 PM CDT TUE JUL 17 2012
THE HIGH THEN LOOKS TO REMAIN OVER THE AREA INTO THE START OF THE
WEEKEND BEFORE THE NEXT FRONT STARTS TO SINK INTO THE AREA.
CURRENT INDICATIONS ARE THAT THIS FRONT WILL MOVE SOUTH ACROSS THE
AREA FROM SATURDAY NIGHT THROUGH MONDAY. THE UPPER LEVEL RIDGE IS
STILL EXPECTED TO BE ANCHORED OVER THE CENTRAL PART OF THE COUNTRY
WITH THE BULK OF THE SHORT WAVE ENERGY RIDING UP OVER THE RIDGE
ACROSS SOUTHERN CANADA. NOT OUT OF THE REALM OF POSSIBILITY THAT
ONE OF THESE WAVES COULD TEMPORARILY FLATTEN THE RIDGE AND GET
INTO THE AREA...BUT WOULD NOT COUNT ON THIS HAPPENING. THUS ANY
RAIN WITH THE FRONT SHOULD STAY ON THE SCATTERED SIDE.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1258 PM CDT TUE JUL 17 2012
CURRENTLY WATCHING A COLD FRONT DROPPING SOUTH THROUGH SOUTHERN
INTO CENTRAL WI. FROPA AT KRST/KLSE EXPECTED TO BE BETWEEN 21-24Z.
VERY WARM AIR MASS AHEAD OF THIS FRONT WITH A FAIRLY STRONG CAP
FOR CONVECTIVE INHIBITION DESPITE THE FRONTAL PASSAGE. THIS WILL
HAVE TO BE MONITORED VERY CLOSELY THIS AFTERNOON. ANY MORE
SURFACE HEATING OR COOLING ALOFT LATER THIS AFTERNOON COULD SPELL
SCATTERED SHRA/TS FOR THE TAF SITES. CONFIDENCE STILL NOT REAL
HIGH IN THIS SCENARIO..,WITH MOST CONVECTION IF ANY STAYING
NORTHEAST OF THE TAF SITES. WILL CONTINUE THE DRY FORECAST FOR
NOW AND CONTINUE TO MONITOR CLOSELY. AFTER FROPA THIS
EVENING/OVERNIGHT...EXPECT A FEW LOWER CLOUDS WITH BASES IN THE
2-3KFT RANGE AFTER 08Z. ALSO...ADDED SOME 6SM BR AT BOTH KRST/KLSE
TAF SITES WITH MOISTENING/COOLING BOUNDARY. WEDNESDAY WILL SEE LOW
PRESSURE PUSHING EAST OUT OF THE CENTRAL PLAINS. THIS LOW WILL
WORK ON THE FRONTAL BOUNDARY FOR SCATTERED SHRA/TS...BUT THIS
LOOKS TO BE MORE IN THE AFTERNOON IN PEAK HEATING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
248 PM CDT TUE JUL 17 2012
WI...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ041>044-053>055-
061.
MN...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ094>096.
IA...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
317 AM EDT THU JUL 19 2012
.SYNOPSIS..
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE UPPER LEVEL PATTERN
HAS NOT SEEN SIGNIFICANT SYNOPTIC CHANGE DURING THE PAST
24 HOURS...HOWEVER WV IMAGERY SHOWS QUITE NICELY THAT A SIGNIFICANT
COLUMN DEEP AIRMASS CHANGE IS APPROACHING FROM THE EAST. THIS
AIRMASS CHANGE WILL FIRST INFLUENCE THE FORECAST OVER THE SOUTHERN
HALF OF THE AREA TODAY...AND MUCH OF THE REGION FOR FRIDAY. UPPER
PATTERN CONSISTS OF RIDGING CENTERED OVER THE SOUTHERN PLAINS/MIDDLE
MS VALLEY...AND ANOTHER STRONG RIDGE CENTER (595DM) CENTERED OFF THE
SOUTHEAST CONUS COAST. IN BETWEEN THESE TWO FEATURES WE CONTINUE TO
FIND A WEAKNESS/TROUGH EXTENDING FROM THE NE GULF OF MEXICO
NORTHWARD ACROSS GA/CAROLINAS. THIS WEAKNESS IS SLOWLY GIVING UP ITS
INFLUENCE ON MUCH OF OUR FORECAST AREA ALLOWING THE RIDGE TO THE
EAST TO BEGIN BUILDING BACK OVER THE FL PENINSULA. THE 19/00Z KTBW
SOUNDING PROFILE STILL SHOWED A RATHER MOIST COLUMN WITH A PW VALUE
AROUND 2" (~120% OF NORMAL). THESE ELEVATED/MOIST VALUES SHOULD BE
FALLING IN THE NEXT 24-36 HOURS.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS CURRENTLY ALIGNED OVER
THE FAR SOUTHERN FL PENINSULA (ROUGHLY ALONG 1-75`S ALLIGATOR
ALLEY)...BUT WILL BE SLOWLY SHIFTING NORTHWARD TO THE CENTRAL
PENINSULA DURING THE NEXT 24 HOURS. OVERALL THE RADAR IS MUCH LESS
ACTIVE THIS MORNING THAN HAS BEEN OBSERVED EARLIER IN THE WEEK.
&&
.SHORT TERM (TODAY THROUGH SATURDAY)...
TODAY...STACKED RIDGING WILL BUILD OVER THE SOUTHERN HALF OF THE
FORECAST AREA ALONG WITH A MUCH DRIER COLUMN. THE I-4 CORRIDOR WILL
BE THE TRANSITION ZONES BETWEEN THIS WARMER AND MORE HOSTILE
ENVIRONMENT FOR CONVECTION...AND COOLER AND CONSIDERABLY MORE MOIST
ENVIRONMENT FURTHER NORTH. NORTH OF ROUGHLY THE I-4 CORRIDOR...THE
MOIST COLUMN AND WEAK SYNOPTIC SUPPORT IN CLOSER PROXIMITY TO THE
MID/UPPER TROUGH TO OUR NW WILL PROVIDE BETTER CHANCES FOR SCATTERED
SHOWERS/STORMS. EXPECT THIS ACTIVITY TO GET GOING IN THE PRE-DAWN
HOURS OVER THE NE GULF AND MIGRATE BACK TO THE NATURE COAST DURING
THE MORNING HOURS. SIMILAR TO WEDNESDAY...THE ENVIRONMENT OVER THESE
NORTHERN ZONES IS NOT VERY CONDUCIVE FOR SEVERE WEATHER...BUT RATHER
LOCALLY HEAVY RAINFALL WILL BE A BIGGER CONCERN. MID-LEVEL THETA-E
VALUES ARE OVER 330K WHICH IS VERY FAVORABLE FOR DEEP CONVECTION.
THE SYNOPTIC LIFT WILL ALSO LIKELY RESULT IN MORE CLOUDS THAN SUN
OVER THE NORTHERN ZONES...WHICH WILL RESULT IN COOLER TEMPS (UPPER
80S-90). HEADING SOUTH FROM I-4 THE FORECAST WILL BE QUITE
DIFFERENT. A DRIER COLUMN WILL LIKELY KEEP RAIN CHANCES BELOW CLIMO.
MORE SUN AND ADDED SUPPRESSION WILL ALLOW THINGS TO HEAT UP THIS
AFTERNOON. LOOKING FOR MANY INLAND AREA TO REACH THE MIDDLE 90S
(EVEN A FEW UPPER 90S). AS OF NOW...THE FORECAST MAXIMUM HEAT
INDICES ARE BETWEEN 100-105F...SO BE CAREFUL IF WORKING OUTDOORS.
HOWEVER...THIS IS BASED ON A 1-TO-1 BLEND OF THE MOIST MAV AND DRIER
MET DEWPOINTS. LOOKING AT THE 00Z UPSTREAM SOUNDING FROM NASSAU IN
THE BAHAMAS...IT WOULD APPEAR THE POTENTIAL FOR MORE SIGNIFICANT DRY
AIR MIXING DOWN IS CERTAINLY THERE. TENDING TO SIDE WITH THE NAM
BASED MET NUMBERS SINCE THE NAM IS GENERALLY BETTER GUIDANCE IN
TERMS OF LOW LEVEL MIXING. WITH THIS IN MIND...THESE HEAT INDICES
ARE LIKELY A WORST CASE SCENARIO...AND ACTUAL DEWPOINTS MAY END UP A
COUPLE DEGREES LOWER.
FRIDAY...UPPER RIDGE AXIS BUILDS STRONG ENOUGH OVERHEAD AND FAR
ENOUGH NORTH TO PUSH MOST INFLUENCE FROM THE UPPER TROUGH OUT OF OUR
NORTHERN ZONES. DRIEST AXIS OF AIR ALSO LOOKS TO MIGRATE A BIT
FURTHER NORTH INTO MAINLY THE CENTRAL AND NORTHERN ZONES. DUE TO THE
MORE UNIFORM SUPPRESSION AND BELOW CLIMO RAIN COVERAGE...WILL
ANTICIPATE A RATHER HOT DAY REGION-WIDE...WITH MANY MID 90S READINGS
AWAY FROM THE COAST. MAY STILL SEE A FEW MORNING SHOWERS MOVING
ONSHORE AROUND CITRUS/LEVY COUNTY...BUT THEREAFTER...THE BEST
CHANCES FOR A SHOWER OR STORM WILL BE LATE IN THE DAY DOWN TOWARD
FORT MYERS. SUBTROPICAL SURFACE RIDGE AXIS WILL MIGRATE NORTHWARD TO
THE CENTRAL PENINSULA ALLOWING A MORE E/SE 1000-700MB FLOW OVER THE
FAR SOUTHERN ZONES. ALONG WITH A SLIGHT INFLUX OF MOISTURE...THIS
FLOW WILL MAXIMIZE LATE DAY CONVERGENCE ALONG THE SW FL COAST
SEA-BREEZE AND LIKELY FIRE A FEW STORMS. ONCE AGAIN...HEAT INDICES
OVER THE INTERIOR LOOK TO MAX OUT BETWEEN 100-105 IN THE AFTERNOON.
SATURDAY...LOOKS LIKE THE DEFINITION OF A SUMMER DAY IN FLORIDA.
STACKED RIDGING WILL STILL BE IN PLACE...WITH BOTH THE LOW LEVEL AND
UPPER LEVEL RIDGE CENTERED OVER THE MID PENINSULA. THE UPPER RIDGE
WILL HOWEVER WEAKEN SLIGHTLY ALONG WITH THE RESULTING SUPPRESSION.
THEREFORE MODELS ARE SHOWING A SLIGHTLY LESS HOSTILE OVERALL
ENVIRONMENT FOR DEEP CONVECTION. SHOULD BE LOOKING AT A TYPICAL
DISTRIBUTION OF MAINLY AFTERNOON/EVENING STORMS ACROSS THE REGION
(30-40% POPS). SLIGHTLY HIGHER RAIN CHANCES WILL AGAIN EXIST DOWN
TOWARD CHARLOTTE/LEE COUNTIES (50%) WITH ANOTHER SETUP OF FAVORABLE
LATE DAY CONVERGENCE ALONG THE SW FL SEA-BREEZE.
&&
.LONG TERM (SUNDAY THROUGH NEXT WEDNESDAY)...
MODELS CONTINUE TO SHOW A STRONG SUB-TROPICAL RIDGE STRETCHING FROM
THE ATLANTIC...WESTWARD ACROSS FLORIDA THROUGH THE EXTENDED PERIOD.
THE RIDGE IS FARTHEST NORTH ON SUNDAY WITH THE AXIS ACTUALLY A BIT
NORTH OF THE STATE. GLOBAL MODELS SHOW DEEP MOISTURE IN THE WAKE OF
A TROPICAL WAVE OVERSPREADING THE STATE FROM THE SOUTHEAST. THE GFS
LOOKS WETTER THAN BOTH THE CANADIAN AND ECMWF...SO SHAVED ABOUT 10
POINTS OF THE MEX POPS FOR NOW. THIS STILL YIELDS SOLID 40 TO 50
PERCENT RAIN CHANCES DURING THE AFTERNOON SUNDAY...WHICH IS CLOSE TO
CLIMATOLOGY ANYWAY.
PRECIPITABLE WATERS REMAIN ELEVATED...ABOVE 2 INCHES THROUGH MONDAY
AFTERNOON BEFORE DRIER AIR MOVES IN BEHIND THE DEPARTING TROPICAL
WAVE. WITH DRIER AIR MOVING IN FROM THE SOUTHEAST...EXPECT HIGHEST
RAIN CHANCES TO BE NORTH OF TAMPA BAY AND LOWER CHANCES AS YOU HEAD
SOUTH.
THE SUB-TROPICAL RIDGE DRIFTS SLOWLY TO THE SOUTH TUESDAY AND
WEDNESDAY AS MID-LEVEL HEIGHTS BEGIN TO FALL OVER THE EASTERN
SEABOARD. THE GFS AND ECMWF ARE SIMILAR ENOUGH TO LEND AT LEAST
MODERATE CONFIDENCE TO THE END OF THE FORECAST PERIOD. WITH THE
RIDGE MOVING SOUTH...MOISTURE WILL MOVE BACK INTO OUR NORTHERN ZONES
ON SOUTHWESTERLY WINDS WHILE THE DRY AIR REMAINS LOCKED INTO THE
REST OF THE REGION FROM THE TAMPA BAY AREA SOUTH.
TEMPERATURES WILL LIKELY RUN A BIT ABOVE NORMAL...ESPECIALLY ON
TUESDAY AND WEDNESDAY WITH THE RIDGE AXIS OVERHEAD THE SOUTHERN HALF
OF OUR FORECAST AREA.
&&
.AVIATION...
SOME SHOWERS AND THUNDERSTORMS MAY DEVELOP OVER THE GULF WATERS
EARLY THIS MORNING AND MOVE NORTHEAST TOWARD TPA...PIE AND SRQ.
EXPECT ACTIVITY TO PUSH RAPIDLY INLAND BY AFTERNOON.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL BE ALIGNED OVER THE EASTERN GULF OF
MEXICO THROUGH SATURDAY KEEPING THE GRADIENT WEAK AND OUR WINDS AND
SEAS FORECAST GENERALLY LOW. LATE IN THE UPCOMING WEEKEND INTO THE
EARLY PORTION OF NEXT WEEK...THIS RIDGE AXIS IS FORECAST TO MIGRATE
NORTH OF THE FORECAST WATERS ALLOWING A MORE ELEVATED EAST TO
SOUTHEAST FLOW TO DEVELOP ACROSS THE EASTERN GULF.
&&
.FIRE WEATHER...
DRIER AIR AND WARMER TEMPERATURES WILL BE BUILDING INTO THE REGION
FOR THE END OF THE WEEK. THESE CONDITIONS WILL BE FIRST FELT ROUGHLY
SOUTH OF THE I-4 CORRIDOR TODAY AND THEN EXPAND NORTHWARD ON FRIDAY.
ALTHOUGH RELATIVE HUMIDITY VALUES WILL GENERALLY BE LOWER THAN WHAT
HAS BEEN EXPERIENCED LATELY...CRITICALLY LOW READINGS ARE NOT
ANTICIPATED AT THIS TIME. INCREASING LOW LEVEL MOISTURE WILL THEN
BEGIN TO ARRIVE FORM THE EAST DURING THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 78 93 78 / 20 10 20 10
FMY 94 77 93 77 / 20 10 40 30
GIF 93 76 95 76 / 30 10 20 10
SRQ 90 76 91 77 / 20 10 20 10
BKV 90 72 95 71 / 40 10 20 10
SPG 90 79 92 80 / 20 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
408 PM EDT TUE JUL 17 2012
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
PRIMARY CONCERN IS COVERAGE OF TSRA THIS AFTERNOON AND EVOLUTION
THIS EVENING. SO FAR TODAY...CONVECTION CLOSELY FOLLOWING MORNING
HRRR RUNS WITH ONE COMPLEX MOVING THROUGH EAST AND NOW SOUTHERN
PARTS OF ATL METRO. OTHER SCT STORMS ACROSS WESTCENTRAL AND FAR NE
GA. HRRR DID PROG ABUNDANT CONVECTION OVER NW GA TO NRN AL ALONG
CUMBERLAND PLATEAU AFTER 21Z WHICH IS NOT PANNING OUT SO FAR.
EXPECT TSRA TO CONTINUE TO PUSH SLOWLY SSW. HEAVY RAIN HAS BEEN
OCCURRING BUT FORTUNATELY...NO ONE AREA IS APPROACHING FFG.
EXPECTION TSRA TO WEAKEN SOME AFTER 6PM AND DISSIPATE BY 9PM.
UPPER LOW OVER NRN FL CONTINUES TO BE PRIMARY FEATURE. THIS LOW
PROGGED BY ALL MODELS TO DRIFT NORTH TONIGHT AND TOMORROW AS IT
GETS PICKED UP BY WEAK WESTERLIES WHICH DRIFT INTO THE MID
ATLANTIC WED. IMPACT FOR CWA IS HIGH MEAN RH AND CONTINUED DIURNAL
CONVECTION WITH NO PREFERENCE FOR ANY ONE LOCATION. CHC POPS
APPEAR MOST APPROPRIATE. ISOLD SVR STORMS AGAIN LIKELY. IF WE GET
MORE CLOUDS OR MORNING PRECIP WED...WILL SEE LESS THAN TODAY.
HAVE TWEAKED MAX TEMP GUIDANCE UP A LITTLE BASED ON RECENT TRENDS
AND MORE ISOLATED AFTERNOON CONVECTION THAN MODELS DEPICTING.
GUIDANCE BLEND WORKING WELL WITH SLIGHT UPWARD ADJUSTMENT FOR MIN
TEMPS.
SNELSON
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MINOR DISCREPANCIES IN MODEL SOLUTIONS FOR THE LONG TERM BUT OVERALL
DECENT GENERAL CONSENSUS. GFS HAS GREATER AMOUNTS OF MOISTURE THAN
THE ECMWF FOR MUCH OF THE FORECAST PERIOD AND SLIGHT DIFFERENCES IN
LOCATION OF THE SFC FRONT PROGGED TO DIP SOUTHWARD INTO THE AREA FOR
THE WEEKEND. DUE TO UNCERTAINTY WITH LOCATION OF THIS BOUNDARY THIS
LATE IN THE FORECAST PERIOD... HAVE MAINTAINED CURRENT FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
BAKER
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
AVIATION...
18Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD OF TSRA THIS AFTERNOON.
MOST LIKELY TIME FOR TSRA IS 18Z-22Z WITH DECREASING COVERAGE
AFTER. COULD SEE WIND GUSTS TO 25KTS WITH ANY STRONG STORMS. HAVE
INCLUDED VCSH FOR 22Z- 01Z FOR LINGERING PRECIP. SIMILAR PATTERN
TOMORROW WITH MAINLY AFTERNOON TSRA. WEST COMPONENT WINDS EXPECTED
THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING AND LIKELIHOOD OF TSRA
HIGH ON ALL OTHER ELEMENTS
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 95 71 94 / 20 40 30 40
ATLANTA 74 92 73 91 / 20 50 30 40
BLAIRSVILLE 67 88 68 87 / 20 40 30 50
CARTERSVILLE 69 93 70 92 / 20 50 30 50
COLUMBUS 75 94 73 92 / 30 50 40 50
GAINESVILLE 72 93 72 91 / 20 40 30 50
MACON 73 94 72 93 / 30 50 30 40
ROME 70 94 71 92 / 20 50 30 50
PEACHTREE CITY 70 93 70 91 / 20 50 40 40
VIDALIA 74 94 74 95 / 30 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
200 PM EDT TUE JUL 17 2012
.PREV DISCUSSION... /ISSUED 113 PM EDT TUE JUL 17 2012/
UPDATE...
QUICK UPDATE TO TWEAK POPS AND WX BASED ON CURRENT TRENDS. TWEAKED
DOWN TEMPS A LITTLE BASED ON MORNING CLOUDS AND EXPECTED PRECIP.
NEW WATCH CONFINED TO FAR SOUTHERN COUNTIES BUT COULD SEE ISOLD
SEVERE STORMS JUST ABOUT ANYWHERE. CONVECTION ALLOWING MODELS...ESP
RECENT HRRR RUNS...FAVORING SOUTHERN GA...NE GA AND ERN ATL METRO THRU
21Z THEN NW GA AFTER 21Z. SEEMS REASONABLE. MID LEVEL CLOUDS
FINALLY DISSIPATING WHICH SHOULD ALLOW TEMPS TO CLIMB QUICKLY.
CAPE ALREADY NEAR 3000 J/KG BASED ON SPC MESOANALYSIS. 0-1KM AND
0-6KM SHEAR VERY WEAK SO EXPECT SLOW MOVING PULSE STORMS YET
AGAIN. PW NEAR 1.9 INCHES SO VERY HEAVY RAINFALL LIKELY WITH ISOLD
FLOODING POSSIBLE.
SNELSON
PREV DISCUSSION... /ISSUED 723 AM EDT TUE JUL 17 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
A COMBINATION OF TWO MAIN FEATURES WILL BE THE FOCUS FOR
THUNDERSTORM DEVELOPMENT THROUGH 48 HOURS. AN H5 LOW JUST OFF THE
GA/FL COAST WAS MOVING ONSHORE AND THE GFS/NAM HAVE A GOOD HANDLE ON
THIS. THIS LOW WILL STALL OVER NORTH FL/SOUTH GA AND CONTINUE TO
PUMP IN ATLANTIC MOISTURE TO THE CWA. THIS UPPER LOW WAS ALSO
PULLING A WEAK SHORT WAVE INTO THE CWA. AT THE SAME TIME A LEE SIDE
TROUGH WAS DEVELOPING FROM LGC TO UPSTATE SOUTH CAROLINA. THE
COMBINATION OF THESE ARE BRINGING THE THREAT OF THUNDERSTORMS TO THE
CWA WITH THE MAIN THREAT DURING DAYTIME HEATING BOTH TODAY AND
WEDNESDAY. THE HIGHEST PROBABILITIES WILL BE IN THE VICINITY OF THE
UPPER LOW...ACROSS CENTRAL GA. THIS WILL ALSO HAVE A PLAY ON TEMPS.
MOST AREAS MONDAY SAW TEMPS IN THE LOW TO MID 90S...HOWEVER IN AREAS
THAT GOT RAIN...TEMPS STRUGGLED TO GET OUT OF THE UPPER 80S. NO
CHANGE IN AIRMASS THROUGH WEDNESDAY AND THIS SHOULD YIELD A
PERSISTENCE IN TEMP FORECASTS.
17
LONG TERM /THURSDAY THROUGH MONDAY/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
.AVIATION...
18Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD OF TSRA THIS AFTERNOON.
MOST LIKELY TIME FOR TSRA IS 18Z-22Z WITH DECREASING COVERAGE
AFTER. COULD SEE WIND GUSTS TO 25KTS WITH ANY STRONG STORMS. HAVE
INCLUDED VCSH FOR 22Z- 01Z FOR LINGERING PRECIP. SIMILAR PATTERN
TOMORROW WITH MAINLY AFTERNOON TSRA. WEST COMPONENT WINDS EXPECTED
THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING AND LIKELIHOOD OF TSRA
HIGH ON ALL OTHER ELEMENTS
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 72 94 72 / 50 30 50 30
ATLANTA 92 74 92 73 / 40 30 50 30
BLAIRSVILLE 87 68 87 67 / 40 30 40 30
CARTERSVILLE 92 70 92 71 / 50 30 40 30
COLUMBUS 93 74 94 73 / 40 30 50 30
GAINESVILLE 92 72 92 72 / 50 30 40 30
MACON 91 73 94 73 / 50 30 50 30
ROME 93 70 94 72 / 60 30 40 30
PEACHTREE CITY 91 71 92 71 / 40 30 50 30
VIDALIA 92 74 94 75 / 50 30 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
113 PM EDT TUE JUL 17 2012
.UPDATE...
QUICK UPDATE TO TWEAK POPS AND WX BASED ON CURRENT TRENDS. TWEAKED
DOWN TEMPS A LITTLE BASED ON MORNING CLOUDS AND EXPECTED PRECIP.
NEW WATCH CONFINED TO FAR SOUTHERN COUNTIES BUT COULD SEE ISOLD
SEVERE STORMS JUST ABOUT ANYWHERE. CONVECTION ALLOWING MODELS...ESP
RECENT HRRR RUNS...FAVORING SOUTHERN GA...NE GA AND ERN ATL METRO THRU
21Z THEN NW GA AFTER 21Z. SEEMS REASONABLE. MID LEVEL CLOUDS
FINALLY DISSIPATING WHICH SHOULD ALLOW TEMPS TO CLIMB QUICKLY.
CAPE ALREADY NEAR 3000 J/KG BASED ON SPC MESOANALYSIS. 0-1KM AND
0-6KM SHEAR VERY WEAK SO EXPECT SLOW MOVING PULSE STORMS YET
AGAIN. PW NEAR 1.9 INCHES SO VERY HEAVY RAINFALL LIKELY WITH ISOLD
FLOODING POSSIBLE.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 723 AM EDT TUE JUL 17 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
A COMBINATION OF TWO MAIN FEATURES WILL BE THE FOCUS FOR
THUNDERSTORM DEVELOPMENT THROUGH 48 HOURS. AN H5 LOW JUST OFF THE
GA/FL COAST WAS MOVING ONSHORE AND THE GFS/NAM HAVE A GOOD HANDLE ON
THIS. THIS LOW WILL STALL OVER NORTH FL/SOUTH GA AND CONTINUE TO
PUMP IN ATLANTIC MOISTURE TO THE CWA. THIS UPPER LOW WAS ALSO
PULLING A WEAK SHORT WAVE INTO THE CWA. AT THE SAME TIME A LEE SIDE
TROUGH WAS DEVELOPING FROM LGC TO UPSTATE SOUTH CAROLINA. THE
COMBINATION OF THESE ARE BRINGING THE THREAT OF THUNDERSTORMS TO THE
CWA WITH THE MAIN THREAT DURING DAYTIME HEATING BOTH TODAY AND
WEDNESDAY. THE HIGHEST PROBABILITIES WILL BE IN THE VICINITY OF THE
UPPER LOW...ACROSS CENTRAL GA. THIS WILL ALSO HAVE A PLAY ON TEMPS.
MOST AREAS MONDAY SAW TEMPS IN THE LOW TO MID 90S...HOWEVER IN AREAS
THAT GOT RAIN...TEMPS STRUGGLED TO GET OUT OF THE UPPER 80S. NO
CHANGE IN AIRMASS THROUGH WEDNESDAY AND THIS SHOULD YIELD A
PERSISTENCE IN TEMP FORECASTS.
17
LONG TERM /THURSDAY THROUGH MONDAY/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
AVIATION...
12Z UPDATE...
EXPECT RAPID CU DEVELOPMENT THIS MORNING WITH SCATTERED SHRA/TSRA
DEVELOPING AROUND NOON AND CONTINUING INTO THIS EVENING. WINDS
OVERALL WILL BE NORTH TO NORTHWEST AROUND 7 KTS OR LESS...EXCEPT
GUSTY IN TSRA. WINDS SHOULD GO CALM THIS EVENING.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON TIMING OF TSRA
HIGH ON ALL OTHER ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 72 94 72 / 50 30 50 30
ATLANTA 92 74 92 73 / 40 30 50 30
BLAIRSVILLE 87 68 87 67 / 40 30 40 30
CARTERSVILLE 92 70 92 71 / 50 30 40 30
COLUMBUS 93 74 94 73 / 40 30 50 30
GAINESVILLE 92 72 92 72 / 50 30 40 30
MACON 91 73 94 73 / 50 30 50 30
ROME 93 70 94 72 / 60 30 40 30
PEACHTREE CITY 91 71 92 71 / 40 30 50 30
VIDALIA 92 74 94 75 / 50 30 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1127 PM CDT WED JUL 18 2012
.DISCUSSION...
OVERALL THE LARGE SCALE PATTERN WILL CHANGE LITTLE FOR US OVER
THROUGH THE FORECAST PERIOD... WITH THE BROAD UPPER RIDGE
CONTINUING TO REIGN OVER THE CENTER OF THE CONTINENT. WE WILL
CONTINUE TO SEE ABOVE NORMAL TEMPERATURES AS A RESULT... WITH
CHANCES FOR PCPN AND SLIGHT COOL DOWNS TIED TO SHORTWAVES MOVING
THEIR WAY AROUND THE PERIPHERY OF THE UPPER RIDGE. THE GFS AND
ECMWF ARE IN REMARKABLY GOOD AGREEMENT THROUGH EARLY NEXT WEEK...
SO ALTHOUGH THEY MAY BE WRONG IT IS TOUGH TO DEVIATE TOO FAR FROM
WHAT THEY ARE SHOWING WITH RESPECT TO THE BIG PICTURE. WILL STICK
CLOSER TO THE ECMWF FOR SOME OF THE DETAILS... MAINLY DUE TO THE
LOW LEVEL COOL/WET BIASES IN THE GFS AND WHAT APPEARS TO BE AN
ASSOCIATED WET BIAS. IN THE SHORTER TERM... UTILIZED THE NAM AND
SREF FOR POP/WEATHER CHANCES AND A CONSENSUS APPROACH FOR
TEMPERATURES... BLENDING WITH POTENTIAL MIX-DOWN VALUES FOR HIGHS.
AN ELONGATED SHORTWAVE TROUGH CURRENTLY APPARENT ON WATER VAPOR
IMAGERY AND RAP UPPER LEVEL PV ANALYSES EXTENDS FROM SOUTHERN
MANITOBA INTO EASTERN NEBRASKA. A LOWER LEVEL MCV FEATURE CAN ALSO
BE SEEN MOVING EAST INTO SOUTH CENTRAL MINNESOTA. THE LATTER
FEATURE IS WORKING TO SUPPORT THE CONVECTIVE ACTIVITY CURRENTLY
OVER THE SOUTHERN PART OF THE AREA... WITH AN OUTFLOW BOUNDARY
FROM THIS MORNING/S CONVECTION ASSISTING WITH THINGS OVER
SOUTHEAST MINNESOTA. THE LARGER SCALE FRONT/BAROCLINIC ZONE IS
NEAR THE MINNESOTA/IOWA BORDER... AND SHOULD HELP TO FURTHER FOCUS
ACTIVITY AS WE HEAD INTO THE EVENING AND THE AFOREMENTIONED LARGE
SCALE SHORTWAVE TROUGH WORKS THROUGH THE AREA. MLCAPE VALUES AOA
2000 J/KG ARE PRESENT ACROSS MOST OF THE AREA... SO THERE IS NO
SHORTAGE OF INSTABILITY. WITH SOME FORCING WORKING ACROSS THE AREA
THROUGH THE EVENING HOURS... THINK WE SHOULD CONTINUE TO SEE SOME
SHRA/TSRA UNTIL WE SEE MORE SUBSTANTIAL MID-LEVEL DRYING AND
SUBSIDENCE LATER TONIGHT. ISOLATED SEVERE STORMS ARE STILL
POSSIBLE GIVEN THE DEGREE OF INSTABILITY... BUT WITH THE DEEP
LAYER SHEAR GENERALLY AOB 30 KT... THE POTENTIAL FOR WIDESPREAD
SEVERE WEATHER APPEARS TO BE LIMITED GIVEN LACK OF EXPECTED
ORGANIZATION WITH MOST STORMS. HOWEVER... A FEW STORMS COULD TAKE
ADVANTAGE OF LOCALLY ENHANCED SHEAR OWING TO THEIR STORM MOTION...
SUCH AS SOME OF THE ACTIVITY CURRENTLY OVER SOUTHEAST MINNESOTA...
AND THOSE WOULD BE THE STORMS MOST LIKELY TO GENERATE SEVERE WEATHER.
SURFACE RIDGING AND MID-LEVEL DRYING/SUBSIDENCE WILL BUILD EAST
ACROSS THE CWFA OVERNIGHT... BRINGING ANY LINGERING SHRA/TSRA TO
AN END. THE NEXT CHANCE FOR PCPN THEN LOOKS TO HOLD OFF UNTIL
FRIDAY NIGHT AND SATURDAY AS THE BAROCLINIC ZONE LIFTS BACK NORTH
ACROSS THE AREA. AT THIS POINT... THE BEST CHANCE LOOKS LIKE IT
WILL BE NORTH OF OUR CWFA CLOSER TO THE WARM FRONTAL BOUNDARY...
BUT THERE IS SUFFICIENT UNCERTAINTY IN THE BOUNDARY PLACEMENT TO
INCLUDE A CHANCE FOR SHRA/TSRA OVER THE NORTHERN HALF OR SO OF THE
AREA. THESE CHANCES WILL THEN SAG SOUTH AND EAST SATURDAY NIGHT
INTO SUNDAY AS A WAVE TRAVELS EAST ALONG THE NEARLY STATIONARY WARM
FRONTAL BOUNDARY. WILL INCLUDE SOME CHANCES FOR PCPN FROM MONDAY
NIGHT INTO WEDNESDAY AS WELL... AFTER DRYING THINGS OUT LATE
SUNDAY AND SUNDAY NIGHT... WITH THE ECMWF AND GFS BOTH SUGGESTING
WE WILL BE NEAR THE BAROCLINIC ZONE/RING OF FIRE AROUND THE
PERIPHERY OF THE UPPER RIDGE AS A FEW SHORTWAVES DROP EAST-
SOUTHEAST FROM WESTERN AND CENTRAL CANADA.
&&
.AVIATION.../06Z TAF ISSUANCE/
SEVERAL CONCERNS WITH LOW CIGS OVERNIGHT...AND EARLY THU MORNING
AS A POCKET OF DRIER AIR ACROSS NW WI/NE MN MOVES SOUTHWEST ACROSS
EASTERN/CENTRAL MN OVER THE NEXT 6 TO 12 HRS. AFT 18Z...NO
CONCERNS AS VFR WX SHOULD CONTINUE THRU 06Z/20.
SFC OBS/VIS FG SATELLITE TRENDS INDICATED THAT A BAND OF IFR
CIGS...ROUGHLY 50-75SM WIDE...CONTINUED TO MOVE SW ACROSS CENTRAL
MN. ONCE THIS BAND MOVES THRU...MVFR/VFR CIGS DEVELOP AS DRIER AIR
FROM THE NE PART OF MN MOVES SW ACROSS THE REGION.
HOWEVER...USUALLY LCL/S LOWER DURING THE OVERNIGHT PERIOD AND
ALLOW FOR LOWER CIGS TO CONTINUE. THIS IS WHAT THE CURRENT RAP
INDICATES ON THE LATEST MODEL RUN. ANOTHER PROBLEM IS WIND SPDS
SEEM TO INCREASE SLIGHTLY ABV THE BOUNDARY LAYER OVERNIGHT WHICH
WILL PRECLUDE FG/BR FORMATION...AND MAYBE ALLOW FOR DRIER AIR TO
FILTER FASTER INTO THE FA. WILL CONTINUE WITH A MORE OPTIMISTIC
FORECAST FOR AXN/STC/RWF THRU 12Z...WITH RNH/MSP/EAU WORSE IN
TERMS OF LOWER CIGS/VSBYS. ONCE THE DRIER AIR TAKES OVER FROM THE
NE...OR THE TYPICAL DAYTIME MIXING DEVELOPS...CIGS SHOULD AT
LEAST LIFT TO MVFR BY 15-18Z...THEN MAINLY VFR DURING THE
AFTN/EVENING. WINDS WILL BE GENERALLY FROM THE N/NE
OVERNIGHT...THEN MORE E/NE DURING THE AFTN...WITH A SHIFT TO THE
E/SE BY EVENING.
MSP...WILL CONTINUE WITH THE WORSE CONDS THRU 15Z...WITH A GENERAL
TREND OF INCREASING THE CIGS TO VFR BY 17-18Z...WITH VFR DURING
THE AFTN/EVENING. STILL CONCERN ON HOW LOW THE VSBY/CIGS BECOME
PRIOR TO SUNRISE AS EARLIER RAINFALL AND SFC WINDS REMAIN
PROBLEMATIC FOR FG/IFR CIGS THIS MORNING. CONFIDENCE IN LOW MVFR
CIGS GOOD UNTIL 12Z...WITH LOW CONFIDENCE AFT 12Z WITH CIGS
LIFTING TO MVFR/VFR DURING THE AFTN. NO RAINFALL/TSRA EXPECTED
THRU 12Z/20.
OUTLOOK...
THU NIGHT/FRI...VFR.
LATE FRI/SAT...VFR BUT INCREASING CHC/S OF TSRA/SHRA. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/JLT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1253 AM CDT THU JUL 19 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS ARE EXPECTED. WIND WILL
REMAIN LIGHT THROUGHOUT THE FORECAST. BEGINNING LIGHT FROM THE
NORTH DURING THE EARLY OVERNIGHT AND BECOMING MORE EAST BY EARLY
THURSDAY MORNING. HOT AND DRY WITH UPPER LEVEL HIGH PRESSURE IN
FIRM CONTROL.
&&
.PREV DISCUSSION... /ISSUED 1011 PM CDT WED JUL 18 2012/
UPDATE...CONTINUED A SLIGHT CHANCE OF THUNDERSTORMS THROUGH LATE
THIS EVENING...MAINLY ALONG AND NORTHWEST OF A LINE FROM LEXINGTON
TO SPALDING NEBRASKA BASED ON CURRENT RADAR AND SATELLITE TRENDS.
PREV DISCUSSION... /ISSUED 619 PM CDT WED JUL 18 2012/
AVIATION...00Z KGRI TAF...EXPECT SOME SHOWERS AND THUNDERSTORMS
TO CONTINUE TO PUSH EASTWARD AND APPROACH THE TERMINAL OVER THE
NEXT COUPLE OF HOURS...POSSIBLY IMPACTING THE TERMINAL AT TIMES
BETWEEN 19/00Z-19/03Z. SO FAR THESE STORMS HAVE BEEN SPOTTY...BUT
PER LATEST GUIDANCE COULD SEE THEM CONTINUE TO INTENSIFY AND
SPREAD IN COVERAGE AS THEY WORK EAST BEFORE SUNSET. LOWERED CIGS
IN AREAS OF SHRAS TO 5KFT...KEEPING CONDITIONS VFR...BUT CERTAINLY
COULD SEE CIGS BELOW THIS IF A HEAVIER SHOWER IMPACTS KGRI.
OTHERWISE...WINDS ARE EXPECTED TO BE LIGHT OVERNIGHT ONCE THE SHRA
AND TSRA ACTIVITY DIMINISHES...BECOMING E TO SE AT LESS THAN 10KTS
DURING THE DAY THURSDAY. AFTER TONIGHTS ACTIVITY...VFR CONDITIONS
ARE EXPECTED THROUGH REMAINDER OF PERIOD.
PREV DISCUSSION... /ISSUED 407 PM CDT WED JUL 18 2012/
SHORT TERM...TODAY THROUGH THURSDAY. WILL KEEP THE VERY SLIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH EARLY
EVENING. THIS IS ONLY A 20 PERCENT CHANCE OF PRECIPITATION. VERY HOT
WEATHER WILL CONTINUE THROUGHOUT THE PERIOD.
VISIBLE SATELLITE IMAGERY DEPICTS AN EXPANDING CU FIELD WITH
DEVELOPING THUNDERSTORMS ACROSS WESTERN NEBRASKA. MOST OF THESE
STORMS WILL DIE PRIOR TO MAKING IT INTO OR CWA. HOWEVER...THERE IS A
SLIGHT CHANCE THAT A FEW OF THESE THUNDERSTORMS MIGHT MAKE IT AS
FAR EAST AS OUR FAR WESTERN ZONES BEFORE DIEING OUT. IT IS HARD TO
PICK OUT BOUNDARIES ON THE SFC MAP WITH THE SFC WINDS BEING VERY
LIGHT AND VARIABLE ACROSS MOST OF OUR CWA. THERE IS A SLIGHTLY
MORE DEFINED SFC BOUNDARY OVER NORTH CENTRAL KANSAS WITH SOUTH
SOUTHWEST WINDS SOUTH OF THE FRONT AND NORTHEAST WINDS NORTH OF
THE FRONT. THE HRRR AND 4KM WRF CONTINUE TO HINT AT THE
POSSIBILITY OF A FEW ISOLATED THUNDERSTORMS OVER OUR CWA EARLY
THIS AFTERNOON. WE HAVE BEEN SEEING A FEW OFF AND ON SHOWERS
ACROSS THE AREA THIS AFTERNOON AND BELIEVE THIS COULD CONTINUE
UNTIL WE LOSE DIURNAL HEATING LATER THIS EVENING.
THE UPPER RIDGE WILL CONTINUE TO BUILD ON THURSDAY AND THIS SHOULD
SHUT DOWN ALL PRECIPITATION CHANCES FOR AWHILE. THEREFORE...EXPECT
DRY CONDITIONS ON THURSDAY AND IT WILL CONTINUE TO BE VERY HOT.
HEAT INDEX VALUES ARE NOT HIGH ENOUGH YET TO PUT NORTHERN ZONES IN
THE HEAT ADVISORY...BUT SOUTHERN ZONES SHOULD ONCE AGAIN SEE
TEMPERATURES/HEAT INDEX VALUES OF 100 TO 105 DEGREES.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE HOT TEMPERATURES AND A CHANCE FOR SOME
THUNDERSTORMS ON WEDNESDAY.
THE UPPER LEVEL RIDGE THAT HAS BEEN THE MAINSTAY ACROSS THE PLAINS
FOR SEVERAL DAYS WILL CONTINUE TO PLAGUE THE FORECAST AREA THROUGH
TUESDAY. TEMPERATURES WILL TOP OUT AROUND 10 DEGREES ABOVE NORMAL.
IN ADDITION TO THE HEAT THE HUMIDITY WILL ALSO CAUSE HEAT INDEX
VALUES TO RISE TO 100 TO 105 FOR NORTH CENTRAL KANSAS AND FAR
SOUTHERN NEBRASKA FOR SATURDAY INTO SUNDAY. THE HEAT CONTINUES
ACROSS THE ENTIRE AREA FOR MONDAY AND TUESDAY...WITH HIGH
TEMPERATURES ACROSS THE AREA EXPECTED TO BE AT OR ABOVE 100 DEGREES.
THERE IS A POTENTIAL FOR A BREAK IN THE HEAT MID WEEK NEXT WEEK. THE
UPPER LEVEL RIDGE FINALLY BREAKS DOWN AS AN UPPER LEVEL WAVE MOVES
THROUGH THE NORTHERN PLAINS. MODELS STILL HAVE SOME DIFFERENCES IN
TIMING AND LOCATION OF THE UPPER WAVE AND THE SURFACE FRONT THAT IS
EXPECTED TO MOVE THROUGH THE AREA. THE GFS IS A LITTLE SLOWER WITH
THE SURFACE FRONT AND A LITTLE FURTHER SOUTH WITH THE UPPER WAVE
THAN THE ECMWF. WILL GO MORE WITH THE SLOWER SOLUTION SINCE THAT IS
TYPICAL OF THE MODELS TO MOVE THINGS THROUGH TOO QUICKLY. WILL HAVE
A CHANCE FOR SOME THUNDERSTORMS IN THE WEST FOR WEDNESDAY AND
TEMPERATURES SHOULD BE A BIT COOLER WITH READINGS ONLY IN THE 90S.
AVIATION...18Z KGRI TAF. A WEAK SFC FRONTAL BOUNDARY HAS STALLED
ACROSS SOUTH CENTRAL NEBRASKA...AND THE BOUNDARY MAY TRIGGER A FEW
SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON. HOWEVER...THIS
ACTIVITY IS EXPECTED TO BE ISOLATED AND HAS NOT BEEN INCLUDED FOR
THE TERMINAL DUE TO THE LIMITED COVERAGE. WITH THE MEANDERING
BOUNDARY RIGHT OVERHEAD...WINDS WILL BE LIGHT AND VARIABLE THROUGH
TONIGHT. THE WIND WILL BECOME MORE EASTERLY TOMORROW. CLEAR TO
SCATTERED CLOUD COVER IS EXPECTED WITH A CONTINUATION OF VFR
CONDITIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR NEZ082>087.
KS...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KSZ005>007-017>019.
&&
$$
AVIATION...HEINLEIN
UPDATE...GUERRERO
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
346 AM EDT THU JUL 19 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER THE CENTRAL PART OF THE
STATE TODAY AND FRIDAY. A FRONTAL BOUNDARY WILL MOVE VERY SLOW AND
THEN STALL OVER EASTERN NORTH CAROLINA SATURDAY BEFORE DISSIPATING
ON SUNDAY. ANOTHER FRONT WILL APPROACH THE AREA FROM THE NORTH BY
WEDNESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 320 AM THURSDAY...MOST OF THE SHOWER ACTIVITY ASSOCIATED
WITH A WEAK CENTER OF VORTICITY MOVING UP THE COAST IS ON A
TRAJECTORY THAT WILL KEEP IT OFFSHORE AND HAVE DROPPED THE SLIGHT
CHC POPS OVER LAND...BUT CONTINUE IN THE COASTAL WATERS. WILL CONTINUE
TO MONITOR RADAR TRENDS THROUGH THE EARLY MORNING HOURS HOWEVER.
THE GFS/NAM AND RAP MODELS ALL INDICATE FAIRLY STRONG SUBSIDENCE
OVER THE INLAND AREAS THIS AFTERNOON. HOWEVER THE NSSL 4 KM
WRF...WHICH HAS DONE QUITE WELL OVER THE PAST SEVERAL DAYS
INDICATES SOME WIDELY SCATTERED CONVECTION BETWEEN ABOUT 19Z AND
01Z TONIGHT WITH THE SEA BREEZE. WILL HAVE A SLIGHT CHANCE POP OVER
AREAS AWAY FROM THE IMMEDIATE COAST FOR ISOLATED SEA BREEZE
CONVECTION THIS AFTERNOON. FOLLOWED PERSISTENCE FOR MAX
TEMPERATURES AS NUMERICAL GUIDANCE HAS BEEN A DEGREE OR TWO TOO
WARM OF LATE...SO AGAIN MOST AREAS WILL FALL A DEGREE OR TWO
EITHER SIDE OF 90 TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 320 AM THURSDAY...TONIGHT WILL BE A CARBON COPY OF THIS
MORNING AS AN AREA OF MID-LEVEL VORTICITY ASSOCIATED WITH THE
CLOSED UPPER LOW OVER NORTHEAST FLORIDA/SOUTH GEORGIA WILL AGAIN
MOVE UP THE COAST AND TRIGGER SOME LIGHT SHOWERS. WILL HAVE A
SLIGHT CHANCE ALONG THE COAST SOUTH OF HATTERAS AGAIN LATE TONIGHT
AND EARLY FRIDAY MORNING. WITH THE CONTINUED SSW/SW FLOW...ANOTHER
WARM MUGGY NIGHT IS IN STORE WITH MINIMUM TEMPERATURES FROM 75 TO
80 DEGREES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 330 AM THU...BROAD SW FLOW WILL CONTINUE ON FRI...THOUGH UPR
HTS WILL FALL JUST A BIT IN RESPONSE TO CENTRAL CONUS RIDGE. BACKED
OFF ON POPS A BIT ON FRI...AS LATEST RUN OF MODELS KEEP ORGANIZED
LIFT WEST AND NORTH OF THE AREA ON FRI. AREAS NEAR THE COAST MAY
REMAIN DRY THROUGH THE DAY...AND HAVE LOWERED POPS TO LOW CHANCE
HERE. STILL A CHANCE FOR SOME SHOWERS WITH ISOLATED THUNDER FRI
NIGHT AS BROAD ISENTROPIC LIFT IS IN PLACE...THOUGH ORGANIZED RAIN
WILL STILL REMAIN NORTHWEST OF E NC CLOSER TO FRONTAL BOUNDARY.
SATURDAY WILL BE THE BEST BET FOR RECEIVING THUNDERSHOWERS AS THE
APPROACHING COOL FRONT REACHES THE VA BORDER. KEPT LIKELY POPS
ACROSS WESTERN/NRN FA CLOSER TO THE FORCING...WITH HIGH CHANCE POPS
NEAR THE COAST. ANY FLOODING LOOKS TO BE MINIMAL...AS BEST MOISTURE
CONVERGENCE WILL RESIDE NORTH OF THE AREA.
FRONT BEGINS TO BECOME DIFFUSE AND LIFT NORTH SUNDAY AS BERMUDA HIGH
WINS BATTLE AND BEGINS TO BUILD BACK WESTWARD...SO THUNDERSHOWER
CHANCES WILL BE MUCH LOWER AND CONVECTION WILL BE MORE TYPICAL
AFTERNOON VARIETY TIED TO SEABREEZE PROPAGATING INLAND.
BROAD NW FLOW REGIME TAKES HOLD BY THE BEGINNING OF NEXT WEEK WITH
SMALL CHANCES FOR THUNDERSTORMS EACH DAY AS S TO SW FLOW CONTINUES
WITH BERMUDA HIGH ENTRENCHED ACROSS THE SW ATLANTIC BASIN.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THU/...
AS OF 1 AM THURSDAY...PERSISTENCE REMAINS THE KEY WORD IN THE
AVIATION FORECAST AS THE BOUNDARY LAYER WILL REMAIN WELL MIXED
WITH 5 TO 10 KNOT SOUTHWEST WINDS. DO NOT EXPECT ANY FOG
OVERNIGHT. APPROACHING SHRT WV FROM NW WILL PRODUCE MORE OF A
CONVECTIVE THREAT THU AFTN...MAINLY FROM NW TO SE...AND INCLUDED
PROB30 GROUPS ALL SITES AFT 20Z.
LONG TERM /THU NIGHT THROUGH MON/...
AS OF 330 AM THUR...MAINLY VFR ON FRI AS HIGH PRESSURE REMAINS NEAR
THE AREA. COULD SEE SOME THUNDERSHOWERS MAINLY IN THE AFTERNOON
ACROSS INLAND LOCALES. BETTER CHANCE OF WIDESPREAD THUNDERSHOWERS ON
SAT AS COOL FRONT DROPS SOUTH AND STALLS NEAR THE VA BORDER...
KEEPING KEEPING BEST CHANCE OF RAIN AWAY FROM THE COAST. MAINLY VFR
THROUGH THE PERIOD EXCEPT IN THUNDERSHOWERS PRODUCING REDUCED VSBYS.
MAY BE SOME FG/BR AT NIGHT/EARLY MORNING IN PLACES THAT RECEIVE
RAIN.
&&
.MARINE...
SHORT TERM /THROUGH THU/...
AS OF 325 AM THURSDAY...AS EXPECTED THE NOCTURNAL SURGE HAS EASED
A BIT...BUT STILL SEEING GUSTS TO 23 KNOTS ON THE PAMLICO
SOUND...TO 24 KNOTS AT OREGON INLET AND 25 KNOTS AT DIAMOND BUOY.
WILL LET THE MARINE WEATHER STATEMENT RUN THROUGH 10Z. SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE COASTAL WATERS SOUTH OF OREGON INLET
STARTING AT 21Z THIS AFTERNOON AND THIS LOOKS GOOD BASED ON LATEST
RUN OF THE WAVEWATCH SHOWING WIDESPREAD 6 FOOT SEAS DEVELOPING BY
LATE AFTERNOON WITH SOLID 15 TO 20 KNOT WINDS. SEAS BUILD TO AS
HIGH AS 7 FEET IN THE ADVISORY AREA TONIGHT WITH CONTINUED
SOUTHWEST WINDS OF 15 TO 20 KNOTS.
LONG TERM /THU NIGHT THROUGH MON/...
AS OF 330 AM THUR...SW WINDS AROUND 20 KT WITH GUSTS AROUND 20 KT
THROUGH SAT NIGHT AS COOL FRONT REMAINS AROUND THE VA BORDER. SEAS
WILL REMAIN ELEVATED ABOVE 6 FT SOUTH OF OREGON INLET THROUGH THIS
TIME PERIOD AS A RESULT. WINDS DIMINISH SOMEWHAT BUT WILL REMAIN
AROUND THE 15 KT RANGE OUT OF THE SW SUNDAY THROUGH EARLY NEXT WEEK.
COULD SEE ANOTHER BOUT OF SCA CONDITIONS DEVELOP AS EARLY AS LATE
MON AS SW GRADIENT GETS PINCHED ONCE AGAIN DUE TO BUILDING PIEDMONT
HEAT TROUGH.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EDT
SATURDAY NIGHT FOR AMZ152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
112 AM EDT THU JUL 19 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE ANCHORED EAST OF THE AREA AND DEEPENING LOW
PRESSURE INLAND WILL BRING MODERATE SOUTHWEST WINDS WITH SCATTERED
THUNDERSTORMS OVER THE NEXT COUPLE DAYS. A LOW PRESSURE TROUGH
INLAND WILL EDGE CLOSER TO THE COAST FRIDAY INTO THE WEEKEND AND
COULD BRING A BETTER CHANCE OF STORMS. A BUILDING RIDGE ALOFT WILL
BRING A DRYING TREND EARLY NEXT WEEK...ACCOMPANIED BY A WARMING
TREND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF MIDNIGHT...QUITE A FEW CHANGES ARE NEEDED TO THE FORECAST FOR
THE REMAINDER OF THE NIGHT. A STRONG LOW-LEVEL JET HAS DEVELOPED
OVERHEAD SINCE SUNSET. DOPPLER RADAR OBSERVED WINDS IN THE LOWEST
SEVERAL THOUSAND FEET OF THE ATMOSPHERE ARE SOUTH-SOUTHWEST AT 20-25
KT. WITH BOUNDARY LAYER LAPSE RATES STILL RELATIVELY STEEP FOR THIS
TIME OF NIGHT A GOOD DEAL OF THIS WIND IS MIXING DOWN TO THE SURFACE
OVER THE COASTAL WATERS AND INLAND WITHIN A FEW MILES OF THE
BEACHES. WINDS AT THE KCRE ASOS ARE SUSTAINED 16 KNOTS CURRENTLY...
WITH RELIABLE MESONET OBSERVATIONS OF 22-24 KNOT GUSTS FROM OAK
ISLAND TO SOUTHPORT AND BALD HEAD ISLAND. IN ADDITION TO INCREASING
COASTAL WIND FORECASTS SIGNIFICANTLY WE HAVE ALSO RAISED LOW
TEMPERATURE FORECASTS ACROSS THE BOARD...NOW RANGING FROM 73-74
INLAND TO AROUND 80 AT THE SOUTH-FACING BEACHES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY..LEFTOVERS OF A WEAKENING UPPER LOW CURRENTLY
NR GA/SC BORDER THE MAIN FEATURE TO DIFFERENTIATE THURSDAYS FORECAST
FROM A MORE TYPICAL/CLIMATOLOGICAL SETUP BASED SOLELY ON MESOSCALE
PROCESSES/HEATING AS FAR AS PRECIP COVERAGE. THIS FEATURE WILL
MEANDER ACROSS THE REGION THROUGH PEAK HEATING...ALTHOUGH GUIDANCE
SHOWS THAT IT WILL NO LONGER HAVE MUCH OF A THERMAL REPRESENTATION.
WHATEVER SMALL BOOST TO POPS IT WILL PROVIDE IT WILL DO SO THROUGH
PVA. THAT SAID THURSDAY SHOULD REPRESENT A SLIGHTLY HIGHER RAIN
CHANCE THAT THE TYPICAL JULY DAY AND STORM INITIATION MAY BE AN HOUR
EARLIER. NOT RAISING POPS TOO MUCH ABOVE CONTINUITY THOUGH AS GFS IS
MUCH SLOWER TO LIFT THIS FEATURE TO THE N. STORM LOCATION COULD
PROBABLY OCCUR AREA-WIDE DUE TO THE VORT MAX BUT LOCALES ALONG THE
FAIRLY PINNED SEABREEZE WILL BE MORE FAVORED DUE TO THE ADDED LIFT
PROVIDED IN THE LOW LEVELS. TEMPS WITHIN A FEW DEG OF CLIMO. HEIGHTS
REMAIN RATHER LOW FOR JULY ON FRIDAY AS THIS FEATURE IS SLOW TO
DRIFT NORTH AWAY FROM THE AREA AND ANOTHER MORE ORGANIZED TROUGH
APPROACHES FROM THE NW. THIS LATTER FEATURE EVEN CAUSES ISOLATED
COVERAGE OF SHOWERS/STORMS THROUGH THE NIGHT ACCORDING TO THE WRF.
SOME ADDITIONAL CLOUD COVER COULD HOLD TEMPS A FEW DEGREES COOLER
THAN THEIR THURSDAY AFTERNOON COUNTERPARTS BUT ANY DEVIATIONS FROM
ACTUAL CLIMATOLOGY WILL BE MINIMAL.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...STALLED FRONT IN THE AREA OVER THE WEEKEND
WILL LEAD TO AN INCREASED CHANCE OF PRECIP. FRONT ARRIVES SAT WITH
LIFT AND DEEP MOISTURE ENHANCED BY DIVERGENT FLOW ALOFT. WEAK 5
TROUGH AXIS WEST OF THE AREA SAT/SUN WILL KEEP DEEP SOUTHWEST FLOW
IN PLACE...ENSURING A STEADY STREAM OF GULF MOISTURE. SAT APPEARS TO
HAVE THE BEST PRECIP CHANCES AS GUIDANCE IS SHOWING SOME WESTWARD
EXPANSION OF THE 5H WESTERN ATLANTIC RIDGE LATER SUN INTO MON.
ARRIVAL OF MID LEVEL DRY AIR AND SUBSIDENCE MAY BE TOO LATE TO HAVE
A SIGNIFICANT IMPACT ON SUN...BUT STARTING MON THE MID LEVEL
INVERSION BEGINS TO STRENGTHEN...DECREASING COVERAGE. THE LESS
FAVORABLE VERTICAL PROFILE AND THE DISSIPATION OF SURFACE BOUNDARY
WILL RESULT IN A TRANSITION BACK TO MORE DIURNAL ACTIVITY FOCUSED ON
THE PIEDMONT TROUGH AND THE SEA BREEZE. INCREASED CLOUD COVER AND
PRECIP COVERAGE WILL KEEP HIGHS A FEW DEGREES BELOW CLIMO FOR THE
WEEKEND...BUT A RETURN TO LOWER 90S IS ANTICIPATED EARLY NEXT WEEK
AS 5H RIDGE BUILDS WEST. LOWS NEAR TO SLIGHTLY ABOVE CLIMO THROUGH
THE PERIOD...HELD UP BY SOUTHWEST FLOW AND LINGERING CLOUD COVER.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...EXPECT VFR THROUGH THE PERIOD WITH ISOLATED TO SCATTERED
SHRA/TSRA...MAINLY THIS AFTERNOON.
PIEDMONT TROUGH INLAND AND BERMUDA HIGH PRESSURE OFFSHORE WILL
PRODUCE A SOUTHWEST SURFACE WIND OVER THE NEXT 24 HOURS. A MODERATE
LOW LEVEL JET THIS MORNING (25 KT WINDS AT 1000-2000 FT AGL) SHOULD
PREVENT FOG FROM DEVELOPING...ALTHOUGH A FEW SHREDS OF LOW
STRATOCUMULUS COULD DEVELOP NEAR THE COAST WHERE TROPICAL MOISTURE
WILL BE GREATEST. LOW PROBABILITIES EXIST FOR CONVECTION THROUGH
DAYBREAK...MAINLY OFFSHORE EAST OF MYR/CRE/ILM AND ALSO INLAND WEST
OF FLO WHERE SOME T-STORM ACTIVITY HAS RECENTLY DEVELOPED.
PROBABILITIES ARE TOO LOW FOR INCLUSION IN THE FORECASTS AT THIS
TIME...BUT VCSH HAS BEEN INCLUDED IN THE KFLO TAF WHERE SHOWERS MAY
BRUSH JUST NORTH OF THE AIRPORT IN THE NEXT SEVERAL HOURS.
AFTER DAYBREAK TYPICAL MID-SUMMER WX IS EXPECTED WITH CUMULUS
DEVELOPING INLAND FROM THE BEACHES IN RESPONSE TO STRONG DAYTIME
HEATING. SCATTERED SHOWERS AND T-STORMS COULD DEVELOP AT ANY
TIME...BUT THE BEST CONCENTRATION SHOULD BE DURING THE AFTERNOON
HOURS (18-23Z) INLAND FROM THE COAST. A MODERATE SEABREEZE DURING
THE AFTERNOON WILL BACK WIND DIRECTIONS AROUND TO THE SOUTH AT
MYR/CRE WITH SURFACE WIND GUSTS EXCEEDING 20 KNOTS.
EXTENDED OUTLOOK...CHANCE OF AFTERNOON SHOWERS AND MORNING FOG EACH
DAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF MIDNIGHT...WE`VE MADE QUITE A FEW CHANGES TO THE FORECAST LATE
THIS EVENING. A "SMALL CRAFT EXERCISE CAUTION" HEADLINE HAS BEEN
ADDED TO THE FORECAST THROUGH 6 AM AS A STRONG LOW LEVEL JET HAS
BEEN PRODUCING 20 KT SUSTAINED WINDS AND GUSTS APPROACHING 25 KT
OVER THE PAST COUPLE OF HOURS. THE PERIOD OF STRONGEST WINDS
ACCORDING TO THE HRRR AND RUC MODELS SHOULD OCCUR BETWEEN NOW AND 6
AM...WHICH IS NOT COINCIDENTALLY THE ENDING TIME OF OUR CAUTIONARY
HEADLINE. WITH STRONGER WINDS HAVE BUILT SEAS TO 5 FT OUT AT THE
FRYING PAN SHOALS BUOY...AND TO 4 FT AT THE NEARSHORE WRIGHTSVILLE
BEACH BUOY. WE`VE ALSO MADE EDITS TO NEARSHORE SEAS FOR ALL OF THE
SOUTH-FACING BEACHES WHERE THIS WIND TRAJECTORY USUALLY RESULTS IN A
CONSIDERABLE AMOUNT OF WAVE ENERGY MAKING IT RIGHT UP TO THE
BEACHES. ISOLATED SHOWERS ARE ALREADY OBSERVED DEVELOPING ON RADAR
OFFSHORE...AND INDICATIONS ARE THESE WILL DEVELOP A LITTLE CLOSER TO
SHORE AS THE NIGHT WEARS ON. ENOUGH WESTERLY STEERING FLOW IS
EXPECTED HOWEVER TO KEEP THE BULK OF ANY NOCTURNAL CONVECTIVE
ACTIVITY AWAY FROM THE BEACHES.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY..A MODERATELY STRONG SOUTHWESTERLY GRADIENT
WIND AND THE PERSISTENCE OF SWELL ENERGY MIXING WITH WIND WAVES
WILL MAKE FOR A BORDERLINE SMALL CRAFT ADVISORY BEING NEEDED FOR
MOST OF THE PERIOD ALONG AREAS ADJACENT TO FRYING PAN SHOALS...ESP
STARTING THURS NIGHT. CONFIDENCE JUST ISNT QUITE HIGH ENOUGH AT THIS
TIME TO GO WITH THE ADVISORY HOWEVER. THE REST OF THE FORECAST
AREA WILL LIKELY BE UNDER SCEC HEADLINES AS 5 FT SEAS AFFECT THE
OUTERMOST PORTIONS IN THE LARGELY COAST-PARALLEL FLOW.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SUMMERTIME PATTERN TO REMAIN IN PLACE THROUGH
THE PERIOD...KEEPING WINDS SOUTHWEST AROUND BACKSIDE OF BERMUDA
HIGH. SPEEDS WILL BE HIGHEST EARLY IN THE PERIOD AS DISSIPATING
FRONT PINCHES THE GRADIENT. SPEEDS SAT INTO SUN WILL RUN 15 TO 20 KT
BUT DROP CLOSE TO 15 KT FOR SUN AND MON AS GRADIENT RELAXES A BIT.
SEAS WILL RUN 3 TO 5 FT ACROSS MUCH OF THE WATERS WITH 5 TO 6 FT
POSSIBLE ACROSS NC WATERS WITH EXTENDED SOUTHWEST FETCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...TRL
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1201 AM EDT THU JUL 19 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE ANCHORED EAST OF THE AREA AND DEEPENING LOW
PRESSURE INLAND WILL BRING MODERATE SOUTHWEST WINDS WITH SCATTERED
THUNDERSTORMS OVER THE NEXT COUPLE DAYS. A LOW PRESSURE TROUGH
INLAND WILL EDGE CLOSER TO THE COAST FRIDAY INTO THE WEEKEND AND
COULD BRING A BETTER CHANCE OF STORMS. A BUILDING RIDGE ALOFT WILL
BRING A DRYING TREND EARLY NEXT WEEK...ACCOMPANIED BY A WARMING
TREND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF MIDNIGHT...QUITE A FEW CHANGES ARE NEEDED TO THE FORECAST FOR
THE REMAINDER OF THE NIGHT. A STRONG LOW-LEVEL JET HAS DEVELOPED
OVERHEAD SINCE SUNSET. DOPPLER RADAR OBSERVED WINDS IN THE LOWEST
SEVERAL THOUSAND FEET OF THE ATMOSPHERE ARE SOUTH-SOUTHWEST AT 20-25
KT. WITH BOUNDARY LAYER LAPSE RATES STILL RELATIVELY STEEP FOR THIS
TIME OF NIGHT A GOOD DEAL OF THIS WIND IS MIXING DOWN TO THE SURFACE
OVER THE COASTAL WATERS AND INLAND WITHIN A FEW MILES OF THE
BEACHES. WINDS AT THE KCRE ASOS ARE SUSTAINED 16 KNOTS CURRENTLY...
WITH RELIABLE MESONET OBSERVATIONS OF 22-24 KNOT GUSTS FROM OAK
ISLAND TO SOUTHPORT AND BALD HEAD ISLAND. IN ADDITION TO INCREASING
COASTAL WIND FORECASTS SIGNIFICANTLY WE HAVE ALSO RAISED LOW
TEMPERATURE FORECASTS ACROSS THE BOARD...NOW RANGING FROM 73-74
INLAND TO AROUND 80 AT THE SOUTH-FACING BEACHES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY..LEFTOVERS OF A WEAKENING UPPER LOW CURRENTLY
NR GA/SC BORDER THE MAIN FEATURE TO DIFFERENTIATE THURSDAYS FORECAST
FROM A MORE TYPICAL/CLIMATOLOGICAL SETUP BASED SOLELY ON MESOSCALE
PROCESSES/HEATING AS FAR AS PRECIP COVERAGE. THIS FEATURE WILL
MEANDER ACROSS THE REGION THROUGH PEAK HEATING...ALTHOUGH GUIDANCE
SHOWS THAT IT WILL NO LONGER HAVE MUCH OF A THERMAL REPRESENTATION.
WHATEVER SMALL BOOST TO POPS IT WILL PROVIDE IT WILL DO SO THROUGH
PVA. THAT SAID THURSDAY SHOULD REPRESENT A SLIGHTLY HIGHER RAIN
CHANCE THAT THE TYPICAL JULY DAY AND STORM INITIATION MAY BE AN HOUR
EARLIER. NOT RAISING POPS TOO MUCH ABOVE CONTINUITY THOUGH AS GFS IS
MUCH SLOWER TO LIFT THIS FEATURE TO THE N. STORM LOCATION COULD
PROBABLY OCCUR AREA-WIDE DUE TO THE VORT MAX BUT LOCALES ALONG THE
FAIRLY PINNED SEABREEZE WILL BE MORE FAVORED DUE TO THE ADDED LIFT
PROVIDED IN THE LOW LEVELS. TEMPS WITHIN A FEW DEG OF CLIMO. HEIGHTS
REMAIN RATHER LOW FOR JULY ON FRIDAY AS THIS FEATURE IS SLOW TO
DRIFT NORTH AWAY FROM THE AREA AND ANOTHER MORE ORGANIZED TROUGH
APPROACHES FROM THE NW. THIS LATTER FEATURE EVEN CAUSES ISOLATED
COVERAGE OF SHOWERS/STORMS THROUGH THE NIGHT ACCORDING TO THE WRF.
SOME ADDITIONAL CLOUD COVER COULD HOLD TEMPS A FEW DEGREES COOLER
THAN THEIR THURSDAY AFTERNOON COUNTERPARTS BUT ANY DEVIATIONS FROM
ACTUAL CLIMATOLOGY WILL BE MINIMAL.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...STALLED FRONT IN THE AREA OVER THE WEEKEND
WILL LEAD TO AN INCREASED CHANCE OF PRECIP. FRONT ARRIVES SAT WITH
LIFT AND DEEP MOISTURE ENHANCED BY DIVERGENT FLOW ALOFT. WEAK 5
TROUGH AXIS WEST OF THE AREA SAT/SUN WILL KEEP DEEP SOUTHWEST FLOW
IN PLACE...ENSURING A STEADY STREAM OF GULF MOISTURE. SAT APPEARS TO
HAVE THE BEST PRECIP CHANCES AS GUIDANCE IS SHOWING SOME WESTWARD
EXPANSION OF THE 5H WESTERN ATLANTIC RIDGE LATER SUN INTO MON.
ARRIVAL OF MID LEVEL DRY AIR AND SUBSIDENCE MAY BE TOO LATE TO HAVE
A SIGNIFICANT IMPACT ON SUN...BUT STARTING MON THE MID LEVEL
INVERSION BEGINS TO STRENGTHEN...DECREASING COVERAGE. THE LESS
FAVORABLE VERTICAL PROFILE AND THE DISSIPATION OF SURFACE BOUNDARY
WILL RESULT IN A TRANSITION BACK TO MORE DIURNAL ACTIVITY FOCUSED ON
THE PIEDMONT TROUGH AND THE SEA BREEZE. INCREASED CLOUD COVER AND
PRECIP COVERAGE WILL KEEP HIGHS A FEW DEGREES BELOW CLIMO FOR THE
WEEKEND...BUT A RETURN TO LOWER 90S IS ANTICIPATED EARLY NEXT WEEK
AS 5H RIDGE BUILDS WEST. LOWS NEAR TO SLIGHTLY ABOVE CLIMO THROUGH
THE PERIOD...HELD UP BY SOUTHWEST FLOW AND LINGERING CLOUD COVER.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID PERIOD WITH ISOLATED TO
SCATTERED SHRA/TSRA THURSDAY AFTERNOON.
SOUTHWEST WINDS WILL PREVAIL THROUGH THE OVERNIGHT HOURS AOB 10
KTS...WITH GUSTS ALONG THE COAST SUBSIDING WITHIN THE NEXT HOUR OR
TWO. CAN EXPECT FEW/SCT HIGH-LEVEL CLOUDS OVERNIGHT...THOUGH WILL
NOT CREATE ANY RESTRICTIONS. FCST GUIDANCE SUGGESTS BRIEF PATCHY
MVFR FOG MAY DEVELOP IN THE EARLY MORNING HOURS AT THE INLAND SITES
GIVEN ANY PERIODS OF NEARLY CALM WINDS. HOWEVER...GIVEN LOWERED
CONFIDENCE...HAVE NOT INTRODUCED INTO CURRENT FCST. IF ANY PATCHY
FOG DOES DEVELOP...EXPECT IT TO CLEAR OUT JUST AFTER DAYBREAK
ALLOWING VFR TO PREVAIL. LOW FEW/SCT CLOUDS IN THE MORNING WILL GIVE
WAY TO MAINLY FEW/SCT MID TO HIGH-LEVEL CLOUDS THROUGHOUT THE
AFTERNOON. ISOLATED TO SCATTERED SHRA/TSRA POSSIBLE DURING THE
AFTERNOON HOURS. SOUTH-SOUTHWEST WINDS WILL PREVAIL AOB 12
KTS...WITH GUSTS UP TO 25 KTS POSSIBLE AT THE COAST...AND POSSIBLY
HIGHER IN ANY THUNDERSTORM. ANY CONVECTION WILL GRADUALLY TAPER OFF
INTO THE EARLY EVENING.
EXTENDED OUTLOOK...CHANCE OF AFTERNOON SHOWERS AND MORNING FOG EACH
DAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF MIDNIGHT...WE`VE MADE QUITE A FEW CHANGES TO THE FORECAST LATE
THIS EVENING. A "SMALL CRAFT EXERCISE CAUTION" HEADLINE HAS BEEN
ADDED TO THE FORECAST THROUGH 6 AM AS A STRONG LOW LEVEL JET HAS
BEEN PRODUCING 20 KT SUSTAINED WINDS AND GUSTS APPROACHING 25 KT
OVER THE PAST COUPLE OF HOURS. THE PERIOD OF STRONGEST WINDS
ACCORDING TO THE HRRR AND RUC MODELS SHOULD OCCUR BETWEEN NOW AND 6
AM...WHICH IS NOT COINCIDENTALLY THE ENDING TIME OF OUR CAUTIONARY
HEADLINE. WITH STRONGER WINDS HAVE BUILT SEAS TO 5 FT OUT AT THE
FRYING PAN SHOALS BUOY...AND TO 4 FT AT THE NEARSHORE WRIGHTSVILLE
BEACH BUOY. WE`VE ALSO MADE EDITS TO NEARSHORE SEAS FOR ALL OF THE
SOUTH-FACING BEACHES WHERE THIS WIND TRAJECTORY USUALLY RESULTS IN A
CONSIDERABLE AMOUNT OF WAVE ENERGY MAKING IT RIGHT UP TO THE
BEACHES. ISOLATED SHOWERS ARE ALREADY OBSERVED DEVELOPING ON RADAR
OFFSHORE...AND INDICATIONS ARE THESE WILL DEVELOP A LITTLE CLOSER TO
SHORE AS THE NIGHT WEARS ON. ENOUGH WESTERLY STEERING FLOW IS
EXPECTED HOWEVER TO KEEP THE BULK OF ANY NOCTURNAL CONVECTIVE
ACTIVITY AWAY FROM THE BEACHES.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY..A MODERATELY STRONG SOUTHWESTERLY GRADIENT
WIND AND THE PERSISTENCE OF SWELL ENERGY MIXING WITH WIND WAVES
WILL MAKE FOR A BORDERLINE SMALL CRAFT ADVISORY BEING NEEDED FOR
MOST OF THE PERIOD ALONG AREAS ADJACENT TO FRYING PAN SHOALS...ESP
STARTING THURS NIGHT. CONFIDENCE JUST ISNT QUITE HIGH ENOUGH AT THIS
TIME TO GO WITH THE ADVISORY HOWEVER. THE REST OF THE FORECAST
AREA WILL LIKELY BE UNDER SCEC HEADLINES AS 5 FT SEAS AFFECT THE
OUTERMOST PORTIONS IN THE LARGELY COAST-PARALLEL FLOW.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SUMMERTIME PATTERN TO REMAIN IN PLACE THROUGH
THE PERIOD...KEEPING WINDS SOUTHWEST AROUND BACKSIDE OF BERMUDA
HIGH. SPEEDS WILL BE HIGHEST EARLY IN THE PERIOD AS DISSIPATING
FRONT PINCHES THE GRADIENT. SPEEDS SAT INTO SUN WILL RUN 15 TO 20 KT
BUT DROP CLOSE TO 15 KT FOR SUN AND MON AS GRADIENT RELAXES A BIT.
SEAS WILL RUN 3 TO 5 FT ACROSS MUCH OF THE WATERS WITH 5 TO 6 FT
POSSIBLE ACROSS NC WATERS WITH EXTENDED SOUTHWEST FETCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...TRL
AVIATION...SGL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
332 AM MDT THU JUL 19 2012
.DISCUSSION...
TODAY THROUGH SATURDAY NIGHT
MASSIVE CENTRAL CONUS RIDGE WILL REMAIN ANCHORED IN PLACE WITH
ANOMALOUSLY LOW MID LEVEL HEIGHTS CONTINUING OVER THE PAC NW. DEEP
SOUTHERLY FLOW BETWEEN THE TWO AFOREMENTIONED SYSTEMS CONTINUES TO
SUPPORT THE ADVECTION OF MID LEVEL MONSOON MOISTURE INTO THE
ROCKIES...WITH NUMEROUS SMALL SCALE IMPULSES BEING EMBEDDED IN THE
FLOW. MEANWHILE A RATHER STRONGER NORTHERN STREAM UPPER TROUGH
CONTINUES TO DIVE SE INTO THE CANADIAN PRAIRIE PROVINCES ON THE
RIDGE PERIPHERY AS THE LINGERING BAJA UPPER VORT MAX EJECTS INTO THE
WESTERN CENTRAL ROCKIES. BOTH OF THESE FEATURES WILL BE PARAMOUNT TO
SENSIBLE WEATHER IN THE PERIOD...AS WELL AS THE STAUNCH THERMAL
RIDGE IN PLACE.
TODAY...THE AFOREMENTIONED NORTHERN STREAM IMPULSE WILL ADVECT ESE
AROUND THE RIDGE PERIPHERY...WITH MODERATE REFLECTED SOUTHERLY FLOW
AHEAD OF THIS FEATURE SUPPORTING CONTINUED LL THETA-E RIDGING AND
ASSOCIATED WAA. VERY WARM TEMPERATURES ARE EXPECTED ACROSS THE FA AS
H85 T/S ARE PROGGED IN THE LOW 30S C. RAP ANALYSIS HIGHLIGHTS A
DECENT AMOUNT OF THETA-E AT H7 WITH RIDGING CONTINUING THERE.
REFLECTED LL TROUGH FROM THE ADVECTING UPPER IMPULSE WILL ADVANCE
EAST THROUGH THE FA TODAY...SUPPORTING INCREASED LOCAL CONVERGENCE
AND MOISTURE POOLING ALL IN THE PRESENCE OF INCREASING LARGE SCALE
ASCENT. THIS SUGGESTS THE POTENTIAL OF CONVECTIVE INITIATION...WHICH
COULD CERTAINLY BE AIDED BY THE BLACK HILLS. EML PLUME WOULD
CERTAINLY SUPPORT THE POTENTIAL FOR INITIAL HIGH BASED CONVECTION
OVER SW AREAS WITH THE ADVANCING H7 TROUGH...BEING AIDED BY DEEP
DIURNAL MIXING. AMPLE LINGERING LL MOISTURE /WHICH WILL MIX OUT TO A
POINT/ WILL BE PRESENT ACROSS THE EASTERN THIRD OF THE FA...ESP
SCENTRAL SD...SUPPORTING THE POTENTIAL FOR BETTER COVERAGE AND
ROBUSTNESS OF CONVECTION. HENCE...HAVE EXPANDED POPS THIS AFTERNOON.
IF CONVECTION DOES DEVELOP AND BECOME ROOTED IN THE DEEPER MOISTURE
IN THE FAR EASTERN FA...THE POTENTIAL WILL EXIST FOR SEVERE CELLS
GIVEN MLCAPES IN EXCESS OF 2 KJ/KG. BULK DEEP LAYER SHEAR IS PROGGED
AT MARGINAL VALUES...BUT ENOUGH COULD CERTAINLY BE PRESENT FOR SOME
CELL ORGANIZATION. MAIN CONCERN WOULD BE DAMAGING WINDS. THE OTHER
CONCERN WILL BE THE HEAT. TEMPS ARE EXPECTED TO APPROACH RECORDS AT
MANY LOCATIONS...WITH HEAT INDEX READINGS IN THE LOW 100S. ANY TS
ACTIVITY WILL EXIT THE FA OVERNIGHT...WITH WARM OVERNIGHT LOWS 65 TO
75 EXPECTED.
FRIDAY-SATURDAY...NORTHERN STREAM RIDGE PERIPHERY IMPULSE WILL
DEPART THE REGION...ORPHANING A SFC BOUNDARY INTO THE FA...MAKING
FOR A TRICKY FORECAST. BASICALLY BLANKETED THE ENTIRE FA WITH POPS
THROUGH MOST OF THE PERIOD...ESP GIVEN AMPLE LL MOISTURE IN PLACE
WITH A MID LEVEL MONSOON CONNECTION/DISTURBED WESTERLY FLOW WITH THE
ARRIVAL OF THE MORE ROBUST CENTRAL ROCKIES UPPER TROUGH/AND AN
EASTERLY UPSLOPE FLOW REGIME. H7 THETA-E FIELDS SUGGEST SUBSTANTIAL
THETA-ADV AND MOISTURE POOLING OVER THE REGION FRIDAY AFTERNOON AND
EVENING WITH INCREASING CHANCES FOR STORMS. STORM CHANCES WILL
CONTINUE INTO SAT WITH DEEP LAYER MOISTURE REMAINING ACROSS MOST OF
THE AREA IN THE PRESENCE OF ANOTHER ADVANCING IMPULSE. RETAINED
HIGHER NUMBERS OVER THE HILLS WHERE HIGH LOCAL INSTABILITY CONTINUES
TO BE PROGGED. SUFFICIENT DEEP LAYER SHEAR/LL MOISTURE AND
ASSOCIATED CAPE WILL BE IN PLACE ACROSS THE FA /ESP NORTHERN
AREAS/...INCREASING THE THREAT FOR SEVERE THUNDERSTORMS. WILL
HIGHLIGHT IN THE HWO. TEMPS WILL BECOME TRICKY GIVEN POTENTIAL
CLOUDS/RAIN/AND NE LL FLOW. WITH THE SFC LOW EXPECTED TO BE OVER SW
SD...HAVE TRENDED TEMPS DOWN ACROSS THE NORTH SOME IN LINE WITH
MOS/MODEL TRENDS...RETAINING WARM NUMBERS OVER SCENTRAL SD BOTH DAYS.
EXTENDED...STRONG UPPER LEVEL RIDGING WILL DOMINATE OVER THE PLAINS
THROUGH MUCH OF THE EXTENDED FORECAST PERIOD. WEST TO SOUTHWEST FLOW
AROUND THE BACK SIDE OF THE RIDGE WILL PERSIST ACROSS THE FORECAST
AREA. THIS WILL BRING DAILY CHANCES FOR THUNDERSTORMS ACROSS A GOOD
PORTION OF THE CWA AS WEAK DISTURBANCES CROSS THE REGION. ABOVE
AVERAGE TEMPERATURES WILL ALSO CONTINUE INTO EARLY NEXT WEEK WITH
HIGHS IN THE 90S TO AROUND 100 ACROSS THE PLAINS. A STRONG SHORTWAVE
SYSTEM IS PROGGED TO MOVE ACROSS SOUTHWESTERN CANADA AND THE
SOUTHERN PRAIRIE PROVINCES TUESDAY AND WEDNESDAY. THIS WOULD WEAKEN
THE RIDGE AND PUSH IT FURTHER SOUTH ACROSS THE PLAINS DURING
MIDWEEK...DROPPING TEMPERATURES A BIT CLOSER TO AVERAGE ON WEDNESDAY
AND ESPECIALLY ON THURSDAY.
&&
.AVIATION...12Z TAFS
VFR CONDITIONS ARE GENERALLY EXPECTED TODAY AND INTO TONIGHT. WINDS
WILL BE SOUTHERLY ACROSS MOST OF THE AREA THIS MORNING. A WEAK
SURFACE TROF WILL SLOWLY MOVE THROUGH NORTHEASTERN WY AND INTO FAR
WESTERN SD IN THE AFTERNOON...SWITCHING WINDS TO THE NORTH-NORTHWEST
BEHIND IT. THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS
MUCH OF WESTERN AND CENTRAL SD THIS AFTERNOON AND EVENING. IF STORMS
DEVELOP...A FEW COULD PRODUCE HAIL AND STRONG WIND GUSTS...MAINLY
NORTH AND EAST OF THE BLACK HILLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...HEAT ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO MIDNIGHT MDT /1
AM CDT/ FRIDAY NIGHT FOR BENNETT-BUTTE-CUSTER CO PLAINS-
FALL RIVER-HAAKON-HARDING-HERMOSA FOOT HILLS-JACKSON-
MELLETTE-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS-
PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SHANNON-SOUTHERN
FOOT HILLS-SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT
HILLS-TODD-TRIPP-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...26
AVIATION...26
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1139 PM CDT WED JUL 18 2012
.AVIATION...
UPPER HIGH PRESSURE WILL EXPAND OVER THE TERMINALS THIS PERIOD
ENSURING VFR CONDITIONS WITH LIGHT SOUTHERLY WINDS.
PREV DISCUSSION... /ISSUED 318 PM CDT WED JUL 18 2012/
SHORT TERM...
AGAIN...CONSIDERABLE QUESTIONS REMAIN AS TO WHETHER OR NOT
CONVECTION WILL BE ABLE TO DEVELOP ACROSS THE FORECAST AREA OR NOT.
UPPER LOW CONTINUES TO SPIN JUST SOUTHEAST OF THE BIG BEND OVER THE
RIO GRANDE AND THERE REMAINS SOME ENHANCED MOISTURE OVER THE REGION.
MODELS REMAIN ALL OVER THE PLACE WITH TIMING...COVERAGE...AND HOW
LONG STORMS MAY STAY AROUND /IF/ THEY DEVELOP. HRRR HAS BEEN FAIRLY
CONSISTENT WITH DEVELOPING ISOLATED TO SCATTERED STORMS ALONG AND
EAST OF THE CAPROCK WHILE THE NAM AND TTU WRF ARE DRY. CU FIELD ON
VISIBLE SATELLITE IS A BIT MORE EXTENSIVE THAN THIS TIME YESTERDAY
BUT TAKING A LOOK OUTSIDE SHOWS LITTLE VERTICAL EXTENT FOR NOW.
RADAR IS SHOWING SOME RETURNS ACROSS THE SOUTHWESTERN TEXAS
PANHANDLE INTO EASTERN NEW MEXICO BUT EVEN THESE ARE DISSIPATING
FAIRLY FAST. WILL KEEP THE FORECAST DRY FOR TONIGHT BUT WILL NEED
TO WATCH THROUGH THE LATE AFTERNOON INTO THE EVENING. TEMPERATURES
WILL BE FAIRLY SIMILAR TO TODAY AND THIS MORNING FOR HIGHS AND LOWS
TOMORROW RESPECTIVELY.
JORDAN
LONG TERM...
UA RIDGE ACROSS COLORADO WILL AMPLIFY AND SHIFT NE TO ACROSS THE
CENTRAL PLAINS ON FRIDAY...AND PERSIST THERE THROUGH THE WEEKEND.
THE MONSOONAL MOISTURE WILL GET NUDGED WEST TO CENTRAL/WESTERN NEW
MEXICO. LARGE SCALE SUBSIDENCE WILL MITIGATE STORM POTENTIAL AND
SLOWLY INCREASING THICKNESS VALUES WILL PROMOTE WARMING TEMPS /UPPER
90S ON THE CAPROCK TO LOWER TRIPLE DIGITS OFF THE CAPROCK/. WILL
NEED TO KEEP AN EYE ON A WEAKNESS/UA IMPULSE ROUNDING THE SOUTHERN
PERIPHERY OF THE SAID RIDGE...AND MOVING ACROSS THE SOUTHERN
PLAINS FRIDAY EVENING/NIGHT. THUS FAR...FORECAST MODELS ARE VOID
OF PRECIP GIVEN A MID LEVEL CAPPING INVERSION AND THIS IMPULSE
APPEARING RELATIVELY WEAK. EARLY NEXT WEEK...BOTH THE GFS AND
ECMWF HINT AT A PACIFIC UA LOW PROPAGATING ENE ACROSS NORTHERN
IDAHO/SOUTHERN ALBERTA. THIS WILL ENCOURAGE THE CENTER OF THE UA
RIDGE TO TRANSLATE SE TO THE SERN CONUS...WHERE IT IS PROGGED TO
REMAIN THROUGH MID-WEEK. AS A RESULT...THE MONSOONAL MOISTURE
PLUME MAY HAVE THE OPPORTUNITY TO NEAR THE WESTERN ZONES.
CONCURRENTLY...AN EASTERLY WAVE IS SHOWN TO MOVE ACROSS THE THE FA
TUESDAY. THE GFS AND ECMWF SOLUTIONS EXHIBIT RATHER LIGHT QPF JUST
EAST AND SE OF THE CWA. WILL NEED TO ANALYZE FUTURE MODEL RUNS TO
SEE IF THIS WAVE WILL TURN OUT TO BE EVEN STRONGER THAN CURRENTLY
INDICATED...AND THUS CREATE CHANCES FOR PRECIP. ATTM...A SILENT
POP FORECAST WILL ENSUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 93 64 94 66 93 / 10 10 0 0 10
TULIA 95 66 94 67 95 / 10 10 0 0 10
PLAINVIEW 93 66 94 68 94 / 10 10 0 0 10
LEVELLAND 93 66 93 66 94 / 10 10 0 0 10
LUBBOCK 94 70 94 68 96 / 10 10 0 0 10
DENVER CITY 93 67 91 66 94 / 10 10 0 0 10
BROWNFIELD 93 67 92 67 95 / 10 10 0 0 10
CHILDRESS 101 71 100 73 101 / 10 10 0 0 10
SPUR 98 70 96 71 98 / 10 10 0 0 10
ASPERMONT 100 73 98 74 101 / 10 10 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
438 AM CDT THU JUL 19 2012
UPDATED VERY SHORT TERM AND ADDED AVIATION DISCUSSION.
.VERY SHORT TERM. TODAY AND TONIGHT.
TODAY.....FORECAST CONFIDENCE IS LOW TO MEDIUM.
CURRENT CONVECTION TRACKING OFF TO THE EAST WITH FORCING AHEAD OF
AXIS OF SHORT WAVE TROUGH. TIMING BACK EDGE OF SCATTERED
PRECIPITATION LEAVES JUST THE NORTHEASTERN CWA WITH ANY CHANCE FOR
PCPN AFTER 12Z...IN LINE WITH EXIT OF LAYER FRONTOGENESIS.
LOW CONFIDENCE PORTION OF FORECAST IS WITH SOME OPERATIONAL AND
HI-RES MODELS PAINTING LARGE QPF BULLS-EYES OVER EAST CENTRAL
WISCONSIN ON APEX OF INVERTED SURFACE TROUGH...WITH SOME UPPER
SUPPORT FROM TRAILING VORT MAX CURRENTLY OVER FAR NRN MN ON WATER
VAPOR LOOPS...AND THEN DROPPING IT THROUGH THE FORECAST AREA LATE
THIS MORNING/AFTERNOON IN NORTHERLY FLOW BEHIND SURFACE LOW AS IT
SHIFTS TOWARDS THE EASTERN GREAT LAKES. LACK OF FORCING AND
OVERDONE CAPE ON RAP SOUNDINGS DUE TO LOW TO MID 70 SURFACE DEW
POINTS GIVE LITTLE CONFIDENCE TO OVERALL SCENARIO SO WILL ONLY
KEEP A SLIGHT CHANCE IN THE NORTHEAST LATER THIS MORNING...AND GO
WITH A DRY AFTERNOON WHICH COLLABORATES WITH SURROUNDING OFFICES.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION DEPICTED ON FORECAST
SOUNDINGS PRODUCING FOG AND LOW CLOUDS TO THE NORTHWEST. HAVE ADDED
SOME FOG TO THE FORECAST IN THE WEST FOR THE REMAINDER OF THE
OVERNIGHT HOURS BEHIND PRECIPITATION AND WILL ALSO ADJUST AS NEEDED
AT ISSUANCE FOR THE EARLY MORNING HOURS.
CLOUDS COULD INHIBIT WARMING...ESPECIALLY IN NORTHEAST CWA...BUT
DELAY IN COLD AIR ADVECTION IN THE 925 MB TO 850 MB LAYER AND SOME
THINNING OF CLOUDS IN THE SOUTHWEST LEND SUPPORT TO CONSENSUS HIGHS
FOR TODAY.
TONIGHT...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE SETTLES OVER REGION WITH CORE OF COLDER 925 TO 850 MB
TEMPERATURES SWINGING THROUGH. ONLY MIXING WITH NORTHEAST WINDS
STAYING UP WELL INTO THE OVERNIGHT WILL PREVENT COOLER LOWS THAN
CONSENSUS LOW TO MID 60S.
.SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM TO HIGH.
UPPER LEVEL HIGH REMAINS OVER THE CENTRAL HIGH PLAINS DURING THIS
PERIOD...WITH NORTHERLY FLOW SHIFTING NORTHWESTERLY IN THE MID TO
UPPER LEVELS. AT THE SURFACE...HIGH PRESSURE SLIDES SLOWLY
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION FRIDAY THROUGH
SATURDAY...THEN SLIDES FURTHER SOUTHEAST SATURDAY NIGHT.
GFS/ECMWF/CANADIAN MODELS TRY TO BRING A WEAK COLD FRONT
SOUTHEAST INTO CENTRAL WISCONSIN BY 00Z SUNDAY. THIS IS
ACCOMPANIED BY A SHORTWAVE TROUGH SLIDING SOUTHEAST THROUGH THE
AREA. AREA FORECAST SOUNDINGS ON NAM/GFS SHOWING SOME MID LEVEL
MOISTURE WITH THESE FEATURES...BUT LOW LEVELS REMAIN QUITE DRY.
FOR NOW...WILL KEEP A DRY FORECAST GOING FOR THE FORECAST
AREA...EXCEPT SMALL POPS IN THE FAR NORTHERN COUNTIES LATE
SATURDAY INTO SATURDAY NIGHT WITH THE SHORTWAVE AND WEAK FRONT.
ONSHORE WINDS WILL CONTINUE TO BRING NEAR NORMAL TEMPERATURES
NEAR THE LAKE FRIDAY...WITH 925MB TEMPERATURES FROM THE NAM
SHOWING MID TO UPPER 80S WELL INLAND. LIGHT WINDS AND MOSTLY
CLEAR SKIES SHOULD ALLOW LOWS INTO THE LOWER 60S AWAY FROM THE
LAKE FRIDAY NIGHT.
WARMER AIRMASS MOVES INTO THE AREA FOR SATURDAY...WITH 925MB
TEMPERATURES ALLOWING FOR HIGHS INTO THE LOWER 90S ACROSS MOST OF
THE AREA. HIGHS SHOULD NEAR 90 CLOSE TO SHORE BEFORE LAKE BREEZE
KICKS IN DURING THE AFTERNOON. MILDER LOWS EXPECTED SATURDAY
NIGHT WITH THE WARMER AIRMASS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF SHOW THE UPPER HIGH LINGERING ACROSS THE CENTRAL PLAINS
DURING THIS PERIOD. THIS ALLOWS FOR WEST NORTHWEST MID TO UPPER
LEVEL FLOW ACROSS THE WESTERN GREAT LAKES REGION.
THESE MODELS DO SHOW A VORTICITY MAXIMUM SHIFTING THROUGH THE AREA
SUNDAY...WEAKER ON THE ECMWF THAN THE GFS. BOTH SHOWING QPF...WITH
THE GFS PROBABLY OVERDONE WITH ITS HIGH DEW POINT AND LOW LEVEL
MOISTURE BIAS. WILL LEAVE POPS IN FORECAST FOR SUNDAY...WITH WARM
TEMPERATURES CONTINUING ACROSS THE AREA.
ECMWF/GFS THEN BRING A WEAK COLD FRONT SOUTHWARD THROUGH
WISCONSIN MONDAY AND MONDAY NIGHT...STALLING TO THE WEST OF THE
AREA TUESDAY BEFORE SHIFTING BACK NORTHEAST THROUGH THE AREA AS A
WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. GFS CONTINUES TO BE
AGGRESSIVE WITH QPF THROUGH MOST OF THIS PERIOD...WITH THE ECMWF
HOLDING OFF UNTIL DEVELOPING QPF NEAR WARM FRONT TUESDAY INTO
WEDNESDAY. GFS AGAIN PROBABLY OVERDONE AT TIMES WITH MOIST LOW
LEVELS...BUT ENOUGH LIFT IN LOW LEVELS FOR LOW POPS TO CONTINUE
MONDAY NIGHT...WITH HIGHER CHANCE POPS BY TUESDAY NIGHT AND
WEDNESDAY.
VERY WARM TEMPERATURES WILL CONTINUE THROUGH THE PERIOD...WITH
HIGHS IN THE LOWER TO MID 90S EXPECTED ACROSS MOST LOCATIONS AWAY
FROM THE LAKE. LAKE BREEZES IN THE AFTERNOON PERIODS MAY LIMIT
HIGHS THERE TO THE UPPER 80S TO AROUND 90.
AVIATION/12Z TAFS/...
PRECIPITATION WILL CLEAR EASTERN-MOST TAF SITES BY 12Z. MOISTURE
FROM RAINS TRAPPED UNDER INVERSION ON FORECAST SOUNDINGS SUPPORT
MVFR CEILINGS...MIXING UP TO VFR LEVELS BY LATE MORNING/EARLY
AFTERNOON IN THE WEST...BUT LINGERING IN THE EAST WITH FLOW OFF OF
LAKE MICHIGAN REDUCING POTENTIAL OF INVERSION MIXING OUT. WATCHING
FOR POTENTIAL OF REDUCED VSBYS AS WELL...ESPECIALLY AT KMSN THIS MORNING.
NAM IFR CIGS APPEAR TO BE DUE TO OVERDONE LOW-LEVEL MOISTURE AND
WILL KEEP CIGS NO LOWER THAN MVFR IN THE EAST...TRENDING THEM UP AFTER
00Z FRIDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT THU JUL 19 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
CURRENT CONVECTION TRACKING OFF TO THE EAST WITH FORCING AHEAD OF
AXIS OF SHORT WAVE TROUGH. TIMING BACK EDGE OF SCATTERED
PRECIPITATION LEAVES JUST THE EASTERN CWA WITH ANY CHANCE FOR PCPN
AFTER 12Z...IN LINE WITH EXIT OF LAYER FRONTOGENESIS. WILL ADJUST
AT ISSUANCE TIME BUT RAPID DIMINISHING TREND MAY MEAN NO MORNING
PRECIPITATION IN FORECAST AREA.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION DEPICTED ON FORECAST
SOUNDINGS PRODUCING FOG AND LOW CLOUDS TO THE NORTHWEST. HAVE
ADDED SOME FOG TO THE FORECAST IN THE WEST FOR THE REMAINDER OF
THE OVERNIGHT HOURS BEHIND PRECIPITATION AND WILL ALSO ADJUST AS
NEEDED AT ISSUANCE FOR THE MORNING HOURS.
LOW CONFIDENCE PORTION OF FORECAST IS WITH SOME OPERATIONAL AND
HI-RES MODELS PAINTING LARGE QPF BULLSEYES OVER EAST CENTRAL
WISCONSIN ON APEX OF INVERTED SURFACE TROUGH...WITH SOME UPPER
SUPPORT FROM TRAILING VORT MAX CURRENTLY OVER FAR NRN MN ON WATER
VAPOR LOOPS...AND THEN DROPPING IT THROUGH THE FORECAST AREA LATE
THIS MORNING/AFTERNOON IN NORTHERLY FLOW BEHIND SURFACE LOW AS IT
SHIFTS TOWARDS THE EASTERN GREAT LAKES. LACK OF FORCING AND
OVERDONE CAPE ON RAP SOUNDINGS DUE TO LOW TO MID 70 SURFACE DEW
POINTS GIVE LITTLE CONFIDENCE TO OVERALL SCENARIO SO WILL GO WITH
A DRY AFTERNOON WHICH COLLABORATES WITH SURROUNDING OFFICES.
.SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM TO HIGH.
UPPER LEVEL HIGH REMAINS OVER THE CENTRAL HIGH PLAINS DURING THIS
PERIOD...WITH NORTHERLY FLOW SHIFTING NORTHWESTERLY IN THE MID TO
UPPER LEVELS. AT THE SURFACE...HIGH PRESSURE SLIDES SLOWLY
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION FRIDAY THROUGH
SATURDAY...THEN SLIDES FURTHER SOUTHEAST SATURDAY NIGHT.
GFS/ECMWF/CANADIAN MODELS TRY TO BRING A WEAK COLD FRONT
SOUTHEAST INTO CENTRAL WISCONSIN BY 00Z SUNDAY. THIS IS
ACCOMPANIED BY A SHORTWAVE TROUGH SLIDING SOUTHEAST THROUGH THE
AREA. AREA FORECAST SOUNDINGS ON NAM/GFS SHOWING SOME MID LEVEL
MOISTURE WITH THESE FEATURES...BUT LOW LEVELS REMAIN QUITE DRY.
FOR NOW...WILL KEEP A DRY FORECAST GOING FOR THE FORECAST
AREA...EXCEPT SMALL POPS IN THE FAR NORTHERN COUNTIES LATE
SATURDAY INTO SATURDAY NIGHT WITH THE SHORTWAVE AND WEAK FRONT.
ONSHORE WINDS WILL CONTINUE TO BRING NEAR NORMAL TEMPERATURES
NEAR THE LAKE FRIDAY...WITH 925MB TEMPERATURES FROM THE NAM
SHOWING MID TO UPPER 80S WELL INLAND. LIGHT WINDS AND MOSTLY
CLEAR SKIES SHOULD ALLOW LOWS INTO THE LOWER 60S AWAY FROM THE
LAKE FRIDAY NIGHT.
WARMER AIRMASS MOVES INTO THE AREA FOR SATURDAY...WITH 925MB
TEMPERATURES ALLOWING FOR HIGHS INTO THE LOWER 90S ACROSS MOST OF
THE AREA. HIGHS SHOULD NEAR 90 CLOSE TO SHORE BEFORE LAKE BREEZE
KICKS IN DURING THE AFTERNOON. MILDER LOWS EXPECTED SATURDAY
NIGHT WITH THE WARMER AIRMASS.
.LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF SHOW THE UPPER HIGH LINGERING ACROSS THE CENTRAL PLAINS
DURING THIS PERIOD. THIS ALLOWS FOR WEST NORTHWEST MID TO UPPER
LEVEL FLOW ACROSS THE WESTERN GREAT LAKES REGION.
THESE MODELS DO SHOW A VORTICITY MAXIMUM SHIFTING THROUGH THE AREA
SUNDAY...WEAKER ON THE ECMWF THAN THE GFS. BOTH SHOWING QPF...WITH
THE GFS PROBABLY OVERDONE WITH ITS HIGH DEWPOINT AND LOW LEVEL
MOISTURE BIAS. WILL LEAVE POPS IN FORECAST FOR SUNDAY...WITH WARM
TEMPERATURES CONTINUING ACROSS THE AREA.
ECMWF/GFS THEN BRING A WEAK COLD FRONT SOUTHWARD THROUGH
WISCONSIN MONDAY AND MONDAY NIGHT...STALLING TO THE WEST OF THE
AREA TUESDAY BEFORE SHIFTING BACK NORTHEAST THROUGH THE AREA AS A
WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. GFS CONTINUES TO BE
AGGRESSIVE WITH QPF THROUGH MOST OF THIS PERIOD...WITH THE ECMWF
HOLDING OFF UNTIL DEVELOPING QPF NEAR WARM FRONT TUESDAY INTO
WEDNESDAY. GFS AGAIN PROBABLY OVERDONE AT TIMES WITH MOIST LOW
LEVELS...BUT ENOUGH LIFT IN LOW LEVELS FOR LOW POPS TO CONTINUE
MONDAY NIGHT...WITH HIGHER CHANCE POPS BY TUESDAY NIGHT AND
WEDNESDAY.
VERY WARM TEMPERATURES WILL CONTINUE THROUGH THE PERIOD...WITH
HIGHS IN THE LOWER TO MID 90S EXPECTED ACROSS MOST LOCATIONS AWAY
FROM THE LAKE. LAKE BREEZES IN THE AFTERNOON PERIODS MAY LIMIT
HIGHS THERE TO THE UPPER 80S TO AROUND 90.
&&
.AVIATION/12Z TAFS/...COMING SOON...
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1209 AM CDT THU JUL 19 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COMPLICATED
SYNOPTIC PATTERN ACROSS THE REGION AT THE MOMENT. FIRST
OFF...REMNANT MCV CONTINUES TO WEAKEN AS IT MOVES NORTHEAST OVER
NORTHWEST WISCONSIN. CAN STILL EXPECT AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS NORTH-CENTRAL AND FAR NORTHEAST
WISCONSIN THROUGH LATE AFTERNOON. PERHAPS A BIGGER CONCERN WILL BE
A DEVELOPING CLUSTER OF SHOWERS AND STORMS OVER SOUTHERN MINNESOTA
AND NORTHERN IOWA THAT IS TRACKING NORTHEAST AS WELL. THIS CLUSTER
IS ALSO GETTING THAT MCV LOOK TO IT AND ITS TRACKING IN THE SAME
TRAJECTORY AS THE MCV FARTHER NORTH. THE LATEST TIMING WOULD CALL
FOR THIS NEXT CLUSTER OF STORMS TO MOVE INTO CENTRAL WISCONSIN
AROUND 00Z. OTHERWISE...THE 850MB BAROCLINIC ZONE REMAINS IN PLACE
FROM NW WISCONSIN TO AROUND KEWAUNEE THIS AFTERNOON. AS SHORTWAVE
ENERGY OVER THE PLAINS INTERACTS WITH THIS THERMAL
GRADIENT...THUNDERSTORM CHANCES AND SEVERITY ARE THE MAIN FORECAST
CONCERNS IN THE SHORT TERM.
TONIGHT...MODELS DO NOT HAVE THE CURRENT WEATHER HANDLED VERY
WELL...SO COULDNT REALLY RELY ON ANY PARTICULAR GUIDANCE. MCV
MOVING OVER NORTHWEST WISCONSIN IS PUTTING A MONKEY WRENCH INTO THE
PLANS...THOUGH THINK IT WILL CONTINUE TO GRADUALLY WEAKEN AS IT
MOVES EAST. WHAT IMPACT THIS MCV WILL HAVE ON THUNDERSTORM
DEVELOPMENT FOR TONIGHT IS NOT CLEAR. IT MAY NOT HAVE MUCH IMPACT
ASSUMING THE STRENGTHENING TRENDS OF THE THUNDERSTORM CLUSTER OVER
SOUTHERN MINNESOTA CONTINUE. AS MENTIONED EARLIER...THIS
THUNDERSTORM COMPLEX WILL ARRIVE EARLY THIS EVENING OVER CENTRAL
WISCONSIN BEFORE TRACKING OVER THE FOX VALLEY AND NE WISCONSIN LATER
IN THE EVENING ASSUMING ITS DIRECTION OF TRAVEL DOES NOT CHANGE. IT WILL
ENCOUNTER ELEVATED CAPES TONIGHT FROM ABOUT 500-800 J/KG SO CANNOT
RULE OUT A STORM BECOMING FEISTY AND PRODUCING NEAR SEVERE
WEATHER...BUT ODDS OF ANYTHING SEVERE HAPPENING IS LOW. HEAVY RAIN
LOOKS TO BE THE MAIN THREAT AND 1 TO 2 INCHES OF RAIN APPEARS POSSIBLE.
HAVE BROAD BRUSHED POPS FOR THE 12 HOUR PERIOD TONIGHT AND HAVE
INCREASED THEM TO LIKELY. WITH THE EXPECTED CLOUD COVER AND
STORMS...RAISED LOWS A COUPLE DEGREES.
THURSDAY...THE SHORTWAVE TROUGH WILL PASS ACROSS THE FORECAST AREA
DURING THE MORNING AND HELP PUSH THE 850MB BAROCLINIC ZONE TO THE
SOUTH BY MIDDAY. WITH CONVERGENCE WEAKENING DURING THE AM
HOURS...WILL KEEP POPS LOW TOMORROW MORNING THEN CLEAR THEM OUT FOR
THE AFTERNOON. PLENTY OF MORNING CLOUD COVER...PLUS LINGERING LOW
LEVEL MOISTURE IN COOL EAST FLOW...SHOULD KEEP TEMPERATURES DOWN
AND WILL SHOW HIGHS IN THE MIDDLE TO UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...PCPN TRENDS
AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
WEAK HIGH PRESSURE WILL MOVE THROUGH THE AREA ON THURSDAY NIGHT
AND FRIDAY. A FEW MODELS GENERATE SOME LGT PCPN ACROSS NC WI ON
FRIDAY...DUE TO WAA/ISENT LIFT...INCREASING MOISTURE CONVERGENCE
AND ELEVATED INSTABILITY. CURRENT THINKING IS THAT THIS PCPN WILL
STAY NW OF GRB CWA THROUGH FRIDAY.
A COLD FRONT WILL WORK ITS WAY INTO NORTHERN WI ON FRIDAY NIGHT...
THEN GRADUALLY SAG SOUTH ACROSS THE FORECAST AREA OVER THE WEEKEND.
THIS FRONT SHOULD BE THE FOCUS FOR ISOLD/SCT TSTM DEVELOPMENT.
ALTHOUGH IT IS FAR FROM A CERTAINTY...MODELS ARE SUGGESTING THAT
THE FRONT MAY SAG FAR ENOUGH SOUTH ON MONDAY/MONDAY NIGHT TO ALLOW
WEAK HIGH PRESSURE TO SETTLE INTO NE WI. WILL TAKE A CHANCE ON A
DRY FCST FOR THOSE PERIODS FOR NOW.
LOW PRESSURE EXPECTED TO MOVE ACROSS SOUTHERN CANADA DURING THE
MIDWEEK PERIOD...WITH A COLD FRONT APPROACHING FROM THE NORTHERN
PLAINS. SW FLOW IN ADVANCE OF THE FRONT WILL LIFT THE OLD FRONT
BACK TO NORTH AS A WARM FRONT...BRINGING A SURGE OF WARMER AND
MORE UNSTABLE AIR INTO C/NE WI. WOULD NOT BE SURPRISED IF WE
SEE A PERIOD OR TWO OF ORGANIZED SEVERE WX LATER TUESDAY INTO
WEDNESDAY...AS INCREASING DEEP LAYER SHEAR COMBINES WITH THE
BUILDING INSTABILITY.
TEMPERATURES WILL REMAIN ABOVE NORMAL IN THE 80S TO AROUND 90
DURING THE PERIOD...AS H8 TEMPS STAY IN THE UPPER TEENS TO AROUND
20 C RANGE. WARMER H8 TEMPS ARE POSSIBLY BY NEXT WEDS...BUT TEMPS
MAY HELD BACK SOMEWHAT BY CONVECTION.
&&
.AVIATION...A TROUGH OF LOW PRESSURE TRACKING OVER THE STATE THIS
MORNING WILL CONTINUE TO GENERATE SCATTERED SHOWERS. AN ISOLATED
STORM IS POSSIBLE AS WELL. MVFR CIGS AND VSBYS CAN BE EXPECTED
WITH THE CONVECTION. SHOWERS AND STORMS WILL COME TO AN END AROUND
18Z OVER EAST CENTRAL WISCONSIN. VFR CONDITIONS WILL THEN PREVAIL
LATER TODAY INTO TONIGHT AS A RIDGE OF HIGH PRESSURE BUILDS INTO
THE STATE.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1100 AM EDT THU JUL 19 2012
.SYNOPSIS...
A COLD FRONT JUST SOUTH OF LONG ISLAND WILL CONTINUE SINKING
FARTHER SOUTH TODAY. WEAK HIGH PRESSURE WILL BUILD FROM THE
NORTH...WHILE WAVES OF LOW PRESSURE MOVE ALONG THE FRONT TO THE
SOUTH THROUGH FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHEAST FOR THE WEEKEND...THEN SLIDE TO THE EAST EARLY NEXT
WEEK...WITH A WEAK COLD FRONT APPROACHING ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1430Z...A NARROW BAND OF SHOWERS WAS MOVING SLOWLY E ACROSS
THE INTERIOR...WHILE A FEW LIGHT SHOWERS ALSO DOTTED PARTS OF
THE NYC METRO AREA. THE 12Z RAP INDICATED THAT THESE AREAS SHOULD
HOLD TOGETHER AND POSSIBLY EXPAND IN AREAL COVERAGE AS A MID LEVEL
VORT MAX SLIDES ACROSS AND PROVIDES WEAK LIFT...SO UPDATED FOR SCT
COVERAGE ACROSS MOST OF THE CWA INTO EARLY AFTERNOON.
EXPECT ABUNDANT MID LEVEL MOISTURE TO REMAIN...WITH MOCLDY SKIES.
HIGH TEMPS WILL BE 10-15 DEGREES COOLER THAN THE LAST FEW DAYS...
IN THE LOWER AND MID 80S...ALONG WITH LOWER RH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
MODELS CONTINUE TO BE IN GENERAL AGREEMENT WITH SHORTWAVE ENERGY
CURRENTLY IN THE LOWER GREAT LAKES REGION TRACKING TOWARDS THE
AREA TONIGHT. THE DISAGREEMENT LIES WITH HOW FAR NORTH THE PRECIP
SHIELD GETS WITH AN INCREASING ELY FLOW...MOISTURE ADVECTION AND
UPSLOPE EFFECTS BATTLING HIGH PRES TO THE N. NAM MASS FIELDS
APPEARED TO BE THE MOST IN LINE AND SIDED MOSTLY WITH ITS SOLN
WITH HIGHEST RAINFALL AMOUNTS ACROSS SW PORTIONS OF THE AREA.
PWATS AROUND 1.5 INCHES THIS AFTN...WILL INCREASE BACK TO AROUND 2
INCHES BY FRI MORNING. SFC BASED INSTABILITY WILL REMAIN S OF THE
AREA AND DO NOT SEE ANY INDICATIONS OF ELEVATED INSTABILITY
PRESENT TONIGHT OR FRI SO NO THUNDER HAS BEEN INCLUDED. PERIODS OF
MODERATE RAINFALL IS POSSIBLE. SEE HYDRO SECTION FOR MORE INFORMATION.
TEMPS ON FRI WILL BE AROUND 10 DEGREES COOLER THAN NORMAL DUE TO ONSHORE
FLOW AND PRECIP...GENERALLY IN THE LOW TO MID 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MEAN TROUGHING APPEARS TO RULE THROUGH THE PERIOD. A WEAK TROUGH
AXIS SLIDES THROUGH THE REGION FRI NIGHT INTO SATURDAY
MORNING...WHICH SHOULD PUSH THE STATIONARY BOUNDARY AND LOW PRESSURE
WAVES FAR ENOUGH SOUTH FOR GRADUAL DRYING CONDITIONS. SCATTERED RAIN
SHOWER ACTIVITY FRIDAY NIGHT EXPECTED TO GRADUALLY TAPER OFF
OVERNIGHT AS A RESULT...BUT SKIES WILL LIKELY ONLY GRADUALLY IMPROVE
THROUGH SATURDAY AFTERNOON AS CANADIAN HIGH PRESSURE BEGINS BUILDING
IN AND A TROUGH AXIS WEAKENS AND DRIFTS EAST.
TROUGHING CONTINUES TO WEAKEN THROUGH THE WEEKEND...WITH CANADIAN
MARITIME HIGH PRESSURE IN CONTROL. TEMPS ON SATURDAY EXPECTED TO RUN
A FEW DEGREES BELOW SEASONABLE WITH ONSHORE FLOW AND EARLY CLOUD
COVER. FAIR AND SEASONABLY WARM CONDITIONS EXPECTED ON SUNDAY.
MODELS IN GOOD AGREEMENT WITH NORTHERN STREAM TROUGHING BEGINNING TO
AMPLIFY TOWARDS THE REGION EARLY NEXT WEEK...WITH A COLD FRONT
SLOWLY WORKING TOWARDS THE REGION THROUGH TUESDAY. AHEAD OF IT...A
RETURN FLOW DEVELOPS ACROSS THE AREA AS HIGH PRESSURE SLIDES
OFFSHORE...WITH INCREASING HEAT AND HUMIDITY LEVELS. INCREASED
INSTABILITY IN THE PRESENCE OF A THERMAL TROUGH WILL PRESENT A
THREAT FOR DIURNAL CONVECTION...MAINLY ACROSS INTERIOR AND WESTERN
SECTION...MONDAY AFTERNOON. PERHAPS A BETTER CHANCE FOR SCATTERED
CONVECTION ACROSS THE ENTIRE AREA TUESDAY AFT/EVE WITH SHORTWAVE
AXIS AND COLD FRONT APPROACHING.
SHORTWAVE AXIS SLIDES EAST ON WEDNESDAY WITH FAIR AND SEASONABLY
WARM CONDITIONS AS WEAK CANADIAN HIGH PRESSURE BUILDS IN.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
HAVE AMENDED MANY OF THE NYC TERMINALS TO BE MORE PESSIMISTIC
THAN PREVIOUSLY THOUGHT. MVFR CLOUD DECK EXPANDING IN NORTHEAST
FLOW BEHIND COLD FRONT PRESENTLY JUST SOUTH OF THE REGION. RADAR
ALSO SHOWS SHOWERS ACROSS NJ WHICH ARE EXPECTED TO HOLD TOGETHER AS
THEY REACH THE NYC AREA. NOT EXPECTING ANY THUNDER WITH THESE
SHOWERS BUT CIGS/VSBY MAY BE REDUCED FOR A BRIEF TIME.
WINDS START OFF FROM THE NORTHEAST AND WILL BECOME EASTERLY OR
E-SE. AROUND 090-130 DEGREES. SPEEDS WILL RANGE BETWEEN 8-12 KT
WITH THE EXCEPTION BEING KLGA WHERE SOUND ENHANCED WIND IS
HELPING TO KEEP WINDS NEAR 15-20KT ALONG THE IMMEDIATE COASTLINE.
THIS EVENING AND TONIGHT THE WINDS LIGHTEN AND BECOME MORE DUE
EASTERLY...AROUND 080-090. SPEEDS WILL BE AROUND 5 KT OR SO. WILL
INTRODUCE SOME SHOWERS ACROSS SOME OF THE SOUTHWEST TERMINALS
AFTER 01Z.
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: SHRA VCNTY OF THE AIRPORT BETWEEN 15-16Z
WITH AMENDMENTS POSSIBLE FOR CIGS/VSBY. ADDITIONAL AMENDMENTS
POSSIBLE FOR CIGS.
KLGA FCSTER COMMENTS: SHRA VCNTY OF THE AIRPORT BETWEEN 15-16Z
WITH AMENDMENTS POSSIBLE FOR CIGS/VSBY. ADDITIONAL AMENDMENTS FOR
CIGS.
KEWR FCSTER COMMENTS: SHRA VCNTY OF THE AIRPORT WITH AMENDMENTS
POSSIBLE FOR CIGS/VSBY. AMENDMENTS POSSIBLE THIS AFTERNOON FOR
CIGS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: SHRA VCNTY OF THE AIRPORT BETWEEN 15-16Z
WITH AMENDMENTS POSSIBLE FOR CIGS/VSBY. ADDITIONAL AMENDMENTS
POSSIBLE FOR CIGS.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
FLUCTUATIONS BETWEEN MVFR AND VFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR
FLUCTUATIONS BETWEEN MVFR AND VFR.
OUTLOOK FOR 12Z FRI THROUGH MON...
.FRI-SAT MORNING...SCT SHOWERS AND MVFR CONDITIONS POSSIBLE...BEST
CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SAT AFTERNOON-SUN NIGHT...VFR.
.MON...CHANCE OF TSTMS.
&&
.MARINE...
A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S COULD RESULT IN OCNL GUSTS UP
TO 25 KT THIS MORNING. FLOW THEN RELAXES WITH SUB-ADVY CONDS
THROUGH THE FIRST HALF OF THE NIGHT. ANOTHER LOW APPROACHING
FROM THE OH VALLEY WILL RESULT IN AN INCREASING E FLOW LATE
TONIGHT INTO FRI...AND MARGINAL SCA CONDS ARE POSSIBLE ON THE
OCEAN WATERS ON FRI.
MARGINAL SCA WINDS AND SEAS LIKELY ON THE OCEAN WATERS FRI NIGHT
WITH A TIGHTER PRES GRADIENT AND STRONGER NE FLOW. GUSTS WILL
LIKELY BE JUST BELOW SCA ON SURROUNDING WATERS. ALTHOUGH WAVEWATCH
HAS HAD A POSITIVE BIAS FOR MUCH OF THE SUMMER...WITH THE STRONGER
FLOW BETWEEN HIGH PRESSURE TO THE NORTH AND LOW PRESSURE TO THE
SOUTH THINK WAVEWATCH SEAS OF 6 TO 7 FT ARE REASONABLE.
CANADIAN MARITIMES HIGH PRESSURE GRADUALLY BUILDS IN ON SATURDAY
WITH DIMINISHING NE WINDS...BUT EASTERLY SCA SWELLS MAY LINGER INTO
SAT EVENING.
SUB SCA CONDITIONS EXPECTED SUNDAY INTO MONDAY WITH WEAK HIGH
PRESSURE IN CONTROL.
&&
.HYDROLOGY...
BASIN AVERAGE QPF IS EXPECTED TO RANGE FROM AROUND 1/10 TO CLOSE
TO 1 INCH...WITH HIGHEST AMOUNTS ACROSS NYC/NE NJ AND LOWEST
AMOUNTS ACROSS EASTERN LI/CT TONIGHT THROUGH FRI EVE. PWATS WILL
INCREASE TO AROUND 2 INCHES LATE TONIGHT AND FRIDAY SO THERE IS A
CHANCE OF MINOR URBAN FLOODING OF LOW LYING AND POOR DRAINAGE
AREAS...ESPECIALLY WHERE HEAVY RAIN FELL YESTERDAY.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRO TIDES DUE TO A RECENT NEW MOON...AND SURGE VIA A
STRONG NE FLOW...MAY COMBINE TO CAUSE MINOR COASTAL FLOODING FRI
NIGHT ALONG THE MORE VULNERABLE COASTAL AREAS OF WESTERN LONG
ISLAND SOUND... THE SOUTHERN AND EASTERN BAYS OF LONG ISLAND...AND
THE SOUTHERN THE BAYS OF NYC. SURGE OF ABOUT 1.5 TO 1.75 FT WILL
BE NEEDED FOR MINOR COASTAL FLOODING DURING THIS TIME.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...GOODMAN
AVIATION...IRD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1024 AM EDT THU JUL 19 2012
.Forecast Update...
Issued at 1023 AM EDT Thu Jul 19 2012
Updated the forecast to refresh grids with latest hourly data and
increase POPs to 50% quicker this morning. Already have storms
firing over the area in a warm soupy airmass. A couple different
boundaries were noted over central IN/OH moving southward this
morning. One of note was rather a lengthy boundary stretching from
western Ohio to southern Indiana to southern IL to southeast MO.
These boundaries will play a crucial role providing a focus for
convective initiation/location today. They`ve already sparked
storms near Jefferson Co, IN and Trimble Co, KY. The HRRR model
seems to be handling convection the best this morning and for the
past several days. According to the latest 10Z run, we should see 2
or 3 notable rounds of convection today. At least one during the
early afternoon hours and another this evening. There could be a
third round in between or possibly late this evening.
&&
.Short Term (Today - Friday)...
Issued at 316 AM EDT Thu Jul 19 2012
...Hot and Humid Followed by Another Round of Strong to Severe
Storms Today...
Current radar imagery shows convective complex that had looked
impressive over southeast Indiana earlier falling apart as it moves
into our less favorable environment. Will continue mention of
diminishing coverage of showers and storms across southeast IN to
the Bluegrass through dawn. Elsewhere, cannot rule out an isolated
shower or storm with moist airmass still in place and remnant
outflow boundaries wandering around.
We`ll set the stage for another hot and humid day as current IR
satellite shows heavy sky cover is rapidly diminishing from earlier
storms. This will likely lead to mostly clear to partly cloudy skies
by dawn and solid heating potential through at least the early
afternoon. As has been the case, temperatures are expected to
quickly rise into the solid mid 90s by early afternoon along and
west of I-65. These temperatures combined with dew points in the
lower 70s will result in heat indices peaking just above 105 degrees
for a few hours this afternoon. Have issued a Heat Advisory along
and west of I-65 to account for this. Further east, heat indices are
expected to max out in the 100-105 range and will likely issue a
special weather statement to highlight.
A look at current water vapor imagery shows a shortwave over the
upper Midwest with an associated surface low currently near the
confluence of SE Iowa, W Illinois, and NE Missouri. The surface low
is expected to move to central Indiana by this evening with
increasing deep layer flow/lift ahead of the positively tilted
shortwave. Coverage of thunderstorms is expected to increase through
the day with numerous storms by late this afternoon and evening. Our
airmass will be strongly unstable (CAPE values between 2500-3500
J/KG suggested by forecast soundings) and with the increasing deep
layer shear, better storm organization in the form of multicells and
forward propagating segments are anticipated. The main threats from
these storms will continue to be torrential rainfall, excessive
cloud to ground lightning and damaging winds. Could also see some
hail in the stronger storms. At this point, the best timing looks to
be from 3 PM to 11 PM EDT.
Scattered to numerous storm coverage will continue through the
evening and overnight hours as surface low drags a cold front to our
doorstep and trough axis remains just to our NW. Best coverage
should be in the east CWA.
Will see chances for showers and storms diminishing from northwest
to southeast through the day on Friday as cold front and trough axis
move through the region. High temperatures are tricky in this
convective and advective pattern, however a noticeable "cool" down
into the upper 80s and low 90s is on tap.
.Long Term (Friday night through Wednesday)...
Issued at 254 AM EDT Thu Jul 19 2012
The upper trof overhead at the start of the long term will weaken
and lift out of the region over the course of Friday night and
Saturday, and will be replaced by upper ridging stretching from the
Plains to the Atlantic through early in the new week with the Ohio
and Tennessee Valleys in a saddle between mounds of high pressure to
our west and east. By mid week the ridge will sink south towards
the Gulf. Since we won`t be right under the heart of the ridge
during this time, we will escape extreme heat and will not be able
to rule out scattered diurnal thunderstorm development -- both good
things for our drought-weary region.
As is typical for this time of year, surface features are weak and
amorphous. It looks like, though, the weak cool front that came
through the area in the short term will sag slowly south of Kentucky
Friday night/Saturday. High pressure to our southeast will weakly
try to build in by Monday, but then another weak cool front will
approach from the northwest during the Tuesday/Wednesday time frame.
The best chances for rain will be in the form of scattered storms
that can pop in the heat of the afternoon over southern Kentucky
Saturday-Monday, and then hopefully more widespread coverage
throughout the region by Wednesday as that front comes in from the
northwest.
High temperatures over the weekend look to be in the upper 80s and
lower 90s, and then in the lower and middle 90s for Monday through
Wednesday...with dew points in the upper 60s to lower 70s. Lows
will be around 70 Saturday morning and in the lower and middle 70s
for the rest of the long term.
&&
.Aviation (12Z TAF Issuance)...
Issued at 651 AM EDT Thu Jul 19 2012
An upper level impulse combined with a surface low moving into
southern Indiana will help to spark numerous afternoon/evening
showers and storms. Some of the storms are expected to be strong to
severe with torrential rains, excessive cloud to ground lightning,
and damaging winds being the main threats. Certainly, conditions
will go MVFR or worse within any thunderstorm. Best timing appears
to be from 3 PM EDT to 11 PM EDT, although there will be chances for
storms through the end of the forecast period. Surface winds will
gradually veer to a southwesterly component today, increasing to
around 10 mph by mid afternoon. Winds will continue to veer
overnight with a cool frontal passage during the first half of the
day on Friday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 10 PM EDT /9 PM CDT/ THIS EVENING FOR
INZ076>079-083-084-089>092.
KY...HEAT ADVISORY UNTIL 10 PM EDT /9 PM CDT/ THIS EVENING FOR
KYZ023>032-061-062-070>072.
$$
Update...........AMS
Short Term.......BJS
Long Term........13
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
637 AM EDT THU JUL 19 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER THE CENTRAL PART OF THE
STATE TODAY AND FRIDAY. A FRONTAL BOUNDARY WILL MOVE VERY SLOW AND
THEN STALL OVER EASTERN NORTH CAROLINA SATURDAY BEFORE DISSIPATING
ON SUNDAY. ANOTHER FRONT WILL APPROACH THE AREA FROM THE NORTH BY
WEDNESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 635 AM THURSDAY...A FEW STRONG TSTMS DEVELOPED AROUND
WILMINGTON EARLIER...BUT HAVE SINCE DISSIPATED. THINK THE FEW
SHOWERS OFF THE SOUTHEAST COAST WILL REMAIN OFFSHORE AND WILL KEEP
LAND AREAS DRY THIS MORNING AS AREA OF MID-LEVEL VORTICITY PASSES
TO OUR NORTH. THE GFS/NAM AND RAP MODELS ALL INDICATE FAIRLY
STRONG SUBSIDENCE OVER THE INLAND AREAS THIS AFTERNOON. HOWEVER
THE NSSL 4 KM WRF...WHICH HAS DONE QUITE WELL OVER THE PAST
SEVERAL DAYS INDICATES SOME WIDELY SCATTERED CONVECTION BETWEEN
ABOUT 19Z AND 01Z TONIGHT WITH THE SEA BREEZE. WILL HAVE A SLIGHT
CHANCE POP OVER AREAS AWAY FROM THE IMMEDIATE COAST FOR ISOLATED
SEA BREEZE CONVECTION THIS AFTERNOON. FOLLOWED PERSISTENCE FOR MAX
TEMPERATURES AS NUMERICAL GUIDANCE HAS BEEN A DEGREE OR TWO TOO
WARM OF LATE...SO AGAIN MOST AREAS WILL FALL A DEGREE OR TWO
EITHER SIDE OF 90 TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 320 AM THURSDAY...TONIGHT WILL BE A CARBON COPY OF THIS
MORNING AS AN AREA OF MID-LEVEL VORTICITY ASSOCIATED WITH THE
CLOSED UPPER LOW OVER NORTHEAST FLORIDA/SOUTH GEORGIA WILL AGAIN
MOVE UP THE COAST AND TRIGGER SOME LIGHT SHOWERS. WILL HAVE A
SLIGHT CHANCE ALONG THE COAST SOUTH OF HATTERAS AGAIN LATE TONIGHT
AND EARLY FRIDAY MORNING. WITH THE CONTINUED SSW/SW FLOW...ANOTHER
WARM MUGGY NIGHT IS IN STORE WITH MINIMUM TEMPERATURES FROM 75 TO
80 DEGREES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 330 AM THU...BROAD SW FLOW WILL CONTINUE ON FRI...THOUGH UPR
HTS WILL FALL JUST A BIT IN RESPONSE TO CENTRAL CONUS RIDGE. BACKED
OFF ON POPS A BIT ON FRI...AS LATEST RUN OF MODELS KEEP ORGANIZED
LIFT WEST AND NORTH OF THE AREA ON FRI. AREAS NEAR THE COAST MAY
REMAIN DRY THROUGH THE DAY...AND HAVE LOWERED POPS TO LOW CHANCE
HERE. STILL A CHANCE FOR SOME SHOWERS WITH ISOLATED THUNDER FRI
NIGHT AS BROAD ISENTROPIC LIFT IS IN PLACE...THOUGH ORGANIZED RAIN
WILL STILL REMAIN NORTHWEST OF E NC CLOSER TO FRONTAL BOUNDARY.
SATURDAY WILL BE THE BEST BET FOR RECEIVING THUNDERSHOWERS AS THE
APPROACHING COOL FRONT REACHES THE VA BORDER. KEPT LIKELY POPS
ACROSS WESTERN/NRN FA CLOSER TO THE FORCING...WITH HIGH CHANCE POPS
NEAR THE COAST. ANY FLOODING LOOKS TO BE MINIMAL...AS BEST MOISTURE
CONVERGENCE WILL RESIDE NORTH OF THE AREA.
FRONT BEGINS TO BECOME DIFFUSE AND LIFT NORTH SUNDAY AS BERMUDA HIGH
WINS BATTLE AND BEGINS TO BUILD BACK WESTWARD...SO THUNDERSHOWER
CHANCES WILL BE MUCH LOWER AND CONVECTION WILL BE MORE TYPICAL
AFTERNOON VARIETY TIED TO SEABREEZE PROPAGATING INLAND.
BROAD NW FLOW REGIME TAKES HOLD BY THE BEGINNING OF NEXT WEEK WITH
SMALL CHANCES FOR THUNDERSTORMS EACH DAY AS S TO SW FLOW CONTINUES
WITH BERMUDA HIGH ENTRENCHED ACROSS THE SW ATLANTIC BASIN.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THU/...
AS OF 635 AM THURSDAY...ONCE AGAIN A WELL-MIXED BOUNDARY LAYER HAS
PRECLUDED THE DEVELOPMENT OF ANY FOG AT THE TAF SITES THIS MORNING
DESPITE A VERY HUMID AIRMASS. MODELS INDICATE A GOOD DEAL OF
SUBSIDENCE OVER THE REGION TODAY...WITH ONLY ISOLATED CONVECTION
NEAR THE SEA BREEZE...THUS NOT ENOUGH COVERAGE OF VICINITY TSTM
LATER TODAY...ALTHOUGH WILL SEE SOME CUMULUS DEVELOPMENT DURING
THE AFTERNOON AND EARLY EVENING. SHOULD CONTINUE TO BE VFR TONIGHT
WITH AGAIN THE SOUTHWEST BREEZE KEEPING THE LOW-LEVELS WELL MIXED.
LONG TERM /THU NIGHT THROUGH MON/...
AS OF 330 AM THUR...MAINLY VFR ON FRI AS HIGH PRESSURE REMAINS NEAR
THE AREA. COULD SEE SOME THUNDERSHOWERS MAINLY IN THE AFTERNOON
ACROSS INLAND LOCALES. BETTER CHANCE OF WIDESPREAD THUNDERSHOWERS ON
SAT AS COOL FRONT DROPS SOUTH AND STALLS NEAR THE VA BORDER...
KEEPING KEEPING BEST CHANCE OF RAIN AWAY FROM THE COAST. MAINLY VFR
THROUGH THE PERIOD EXCEPT IN THUNDERSHOWERS PRODUCING REDUCED VSBYS.
MAY BE SOME FG/BR AT NIGHT/EARLY MORNING IN PLACES THAT RECEIVE
RAIN.
&&
.MARINE...
SHORT TERM /THROUGH THU/...
AS OF 635 AM THURSDAY...INITIATED A SMALL CRAFT ADVISORY FOR THE
COASTAL WATERS SOUTH OF OREGON INLET A BIT EARLIER GIVEN COMBINED
SEAS OF 6 FEET FROM BOTH THE DIAMOND BUOY AND THE BUOY 30 MILES SE
OF NEW RIVER INLET. AN EARLIER SURGE HAS SUBSIDED BUT STILL SEEING
SOLID 15 TO 20 KNOTS WINDS IN THE CENTRAL WATERS WITH GUSTS TO 22
KNOTS AT OREGON INLET AND 21 KNOTS AT DIAMOND BUOY AND 30 MILES SE
OF NEW RIVER INLET. SEAS BUILD TO AS HIGH AS 7 FEET IN THE
ADVISORY AREA TONIGHT WITH CONTINUED SOUTHWEST WINDS OF 15 TO 20
KNOTS.
LONG TERM /THU NIGHT THROUGH MON/...
AS OF 330 AM THUR...SW WINDS AROUND 20 KT WITH GUSTS AROUND 20 KT
THROUGH SAT NIGHT AS COOL FRONT REMAINS AROUND THE VA BORDER. SEAS
WILL REMAIN ELEVATED ABOVE 6 FT SOUTH OF OREGON INLET THROUGH THIS
TIME PERIOD AS A RESULT. WINDS DIMINISH SOMEWHAT BUT WILL REMAIN
AROUND THE 15 KT RANGE OUT OF THE SW SUNDAY THROUGH EARLY NEXT WEEK.
COULD SEE ANOTHER BOUT OF SCA CONDITIONS DEVELOP AS EARLY AS LATE
MON AS SW GRADIENT GETS PINCHED ONCE AGAIN DUE TO BUILDING PIEDMONT
HEAT TROUGH.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR
AMZ152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL/LEP
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
615 AM MDT THU JUL 19 2012
.AVIATION...12Z TAFS
VFR CONDITIONS ARE GENERALLY EXPECTED TODAY INTO TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS
NORTHWESTERN SD EARLY THIS MORNING AND WILL MOVE EASTWARD ACROSS
THE AREA THROUGH THE MID MORNING HOURS. WINDS WILL BE SOUTH-
SOUTHEAST ACROSS MOST OF THE AREA THIS MORNING. A WEAK SURFACE
TROF WILL SLOWLY MOVE THROUGH NORTHEASTERN WY THIS MORNING AND
INTO FAR WESTERN SD IN THE AFTERNOON...SWITCHING WINDS TO THE
NORTH- NORTHWEST BEHIND IT. THERE WILL BE A SLIGHT CHANCE FOR
THUNDERSTORMS ACROSS MUCH OF WESTERN AND CENTRAL SD THIS AFTERNOON
AND EVENING. IF STORMS DEVELOP LATER TODAY...A FEW COULD PRODUCE
HAIL AND STRONG WIND GUSTS...MAINLY NORTH AND EAST OF THE BLACK
HILLS.
&&
.PREV DISCUSSION... /ISSUED 332 AM MDT THU JUL 19 2012/
DISCUSSION...
TODAY THROUGH SATURDAY NIGHT
MASSIVE CENTRAL CONUS RIDGE WILL REMAIN ANCHORED IN PLACE WITH
ANOMALOUSLY LOW MID LEVEL HEIGHTS CONTINUING OVER THE PAC NW. DEEP
SOUTHERLY FLOW BETWEEN THE TWO AFOREMENTIONED SYSTEMS CONTINUES TO
SUPPORT THE ADVECTION OF MID LEVEL MONSOON MOISTURE INTO THE
ROCKIES...WITH NUMEROUS SMALL SCALE IMPULSES BEING EMBEDDED IN THE
FLOW. MEANWHILE A RATHER STRONGER NORTHERN STREAM UPPER TROUGH
CONTINUES TO DIVE SE INTO THE CANADIAN PRAIRIE PROVINCES ON THE
RIDGE PERIPHERY AS THE LINGERING BAJA UPPER VORT MAX EJECTS INTO THE
WESTERN CENTRAL ROCKIES. BOTH OF THESE FEATURES WILL BE PARAMOUNT TO
SENSIBLE WEATHER IN THE PERIOD...AS WELL AS THE STAUNCH THERMAL
RIDGE IN PLACE.
TODAY...THE AFOREMENTIONED NORTHERN STREAM IMPULSE WILL ADVECT ESE
AROUND THE RIDGE PERIPHERY...WITH MODERATE REFLECTED SOUTHERLY FLOW
AHEAD OF THIS FEATURE SUPPORTING CONTINUED LL THETA-E RIDGING AND
ASSOCIATED WAA. VERY WARM TEMPERATURES ARE EXPECTED ACROSS THE FA AS
H85 T/S ARE PROGGED IN THE LOW 30S C. RAP ANALYSIS HIGHLIGHTS A
DECENT AMOUNT OF THETA-E AT H7 WITH RIDGING CONTINUING THERE.
REFLECTED LL TROUGH FROM THE ADVECTING UPPER IMPULSE WILL ADVANCE
EAST THROUGH THE FA TODAY...SUPPORTING INCREASED LOCAL CONVERGENCE
AND MOISTURE POOLING ALL IN THE PRESENCE OF INCREASING LARGE SCALE
ASCENT. THIS SUGGESTS THE POTENTIAL OF CONVECTIVE INITIATION...WHICH
COULD CERTAINLY BE AIDED BY THE BLACK HILLS. EML PLUME WOULD
CERTAINLY SUPPORT THE POTENTIAL FOR INITIAL HIGH BASED CONVECTION
OVER SW AREAS WITH THE ADVANCING H7 TROUGH...BEING AIDED BY DEEP
DIURNAL MIXING. AMPLE LINGERING LL MOISTURE /WHICH WILL MIX OUT TO A
POINT/ WILL BE PRESENT ACROSS THE EASTERN THIRD OF THE FA...ESP
SCENTRAL SD...SUPPORTING THE POTENTIAL FOR BETTER COVERAGE AND
ROBUSTNESS OF CONVECTION. HENCE...HAVE EXPANDED POPS THIS AFTERNOON.
IF CONVECTION DOES DEVELOP AND BECOME ROOTED IN THE DEEPER MOISTURE
IN THE FAR EASTERN FA...THE POTENTIAL WILL EXIST FOR SEVERE CELLS
GIVEN MLCAPES IN EXCESS OF 2 KJ/KG. BULK DEEP LAYER SHEAR IS PROGGED
AT MARGINAL VALUES...BUT ENOUGH COULD CERTAINLY BE PRESENT FOR SOME
CELL ORGANIZATION. MAIN CONCERN WOULD BE DAMAGING WINDS. THE OTHER
CONCERN WILL BE THE HEAT. TEMPS ARE EXPECTED TO APPROACH RECORDS AT
MANY LOCATIONS...WITH HEAT INDEX READINGS IN THE LOW 100S. ANY TS
ACTIVITY WILL EXIT THE FA OVERNIGHT...WITH WARM OVERNIGHT LOWS 65 TO
75 EXPECTED.
FRIDAY-SATURDAY...NORTHERN STREAM RIDGE PERIPHERY IMPULSE WILL
DEPART THE REGION...ORPHANING A SFC BOUNDARY INTO THE FA...MAKING
FOR A TRICKY FORECAST. BASICALLY BLANKETED THE ENTIRE FA WITH POPS
THROUGH MOST OF THE PERIOD...ESP GIVEN AMPLE LL MOISTURE IN PLACE
WITH A MID LEVEL MONSOON CONNECTION/DISTURBED WESTERLY FLOW WITH THE
ARRIVAL OF THE MORE ROBUST CENTRAL ROCKIES UPPER TROUGH/AND AN
EASTERLY UPSLOPE FLOW REGIME. H7 THETA-E FIELDS SUGGEST SUBSTANTIAL
THETA-ADV AND MOISTURE POOLING OVER THE REGION FRIDAY AFTERNOON AND
EVENING WITH INCREASING CHANCES FOR STORMS. STORM CHANCES WILL
CONTINUE INTO SAT WITH DEEP LAYER MOISTURE REMAINING ACROSS MOST OF
THE AREA IN THE PRESENCE OF ANOTHER ADVANCING IMPULSE. RETAINED
HIGHER NUMBERS OVER THE HILLS WHERE HIGH LOCAL INSTABILITY CONTINUES
TO BE PROGGED. SUFFICIENT DEEP LAYER SHEAR/LL MOISTURE AND
ASSOCIATED CAPE WILL BE IN PLACE ACROSS THE FA /ESP NORTHERN
AREAS/...INCREASING THE THREAT FOR SEVERE THUNDERSTORMS. WILL
HIGHLIGHT IN THE HWO. TEMPS WILL BECOME TRICKY GIVEN POTENTIAL
CLOUDS/RAIN/AND NE LL FLOW. WITH THE SFC LOW EXPECTED TO BE OVER SW
SD...HAVE TRENDED TEMPS DOWN ACROSS THE NORTH SOME IN LINE WITH
MOS/MODEL TRENDS...RETAINING WARM NUMBERS OVER SCENTRAL SD BOTH DAYS.
EXTENDED...STRONG UPPER LEVEL RIDGING WILL DOMINATE OVER THE PLAINS
THROUGH MUCH OF THE EXTENDED FORECAST PERIOD. WEST TO SOUTHWEST FLOW
AROUND THE BACK SIDE OF THE RIDGE WILL PERSIST ACROSS THE FORECAST
AREA. THIS WILL BRING DAILY CHANCES FOR THUNDERSTORMS ACROSS A GOOD
PORTION OF THE CWA AS WEAK DISTURBANCES CROSS THE REGION. ABOVE
AVERAGE TEMPERATURES WILL ALSO CONTINUE INTO EARLY NEXT WEEK WITH
HIGHS IN THE 90S TO AROUND 100 ACROSS THE PLAINS. A STRONG SHORTWAVE
SYSTEM IS PROGGED TO MOVE ACROSS SOUTHWESTERN CANADA AND THE
SOUTHERN PRAIRIE PROVINCES TUESDAY AND WEDNESDAY. THIS WOULD WEAKEN
THE RIDGE AND PUSH IT FURTHER SOUTH ACROSS THE PLAINS DURING
MIDWEEK...DROPPING TEMPERATURES A BIT CLOSER TO AVERAGE ON WEDNESDAY
AND ESPECIALLY ON THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...HEAT ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO MIDNIGHT MDT /1
AM CDT/ FRIDAY NIGHT FOR BENNETT-BUTTE-CUSTER CO PLAINS-
FALL RIVER-HAAKON-HARDING-HERMOSA FOOT HILLS-JACKSON-
MELLETTE-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS-
PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SHANNON-SOUTHERN
FOOT HILLS-SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT
HILLS-TODD-TRIPP-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM....26
AVIATION...26
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1004 AM MDT THU JUL 19 2012
.UPDATE...15Z SURFACE ANALYSIS/RADAR SHOWED WEAK LOW NEAR
PIEDMONT. DECENT GRADIENT AHEAD OF LOW BRINGING A FEW BREEZY SPOTS
TO THE SD PLAINS...SO HAVE RAISED WIND SPEEDS SOME TODAY. MIXED
BOUNDARY LAYER INDUCED DRY LINE ALSO NOTED ON RADAR AROUND THE
NORTH/EAST FOOTHILLS WITH TD/S IN THE UPPER 30S FOR THE HIGHER
ELEVATIONS. HAVE THUS LOWERED DEW POINTS SOME FOR THE BLACK HILLS
AND NORTHEAST WY. LEFTOVER -TSRA EXITING CWA NORTHEAST OF
KD07...SO HAVE ADJUSTED POPS FOR THAT AREA THIS MORNING.
LOOKING AHEAD TO THIS AFTERNOON/THIS EVENING...THERMAL RIDGE
CONTINUES TO BUILD INTO THE CWA INCREASING THE CAP OVER THE AREA.
MLCAPE RISES TO 1-2KJ/KG IN A STRIPE FROM KD07 TO KICR...WITH
READINGS LESS THAN 1KJ/KG FURTHER WEST. WATER VAPOUR SHOWED WEAK
SHORTWAVE OVER CENTRAL WY HEADING NORTHEAST INTO ND THROUGH
TONIGHT. IT REMAINS TO BE SEEN HOW MUCH DIURNAL CONVECTION WE GET
TODAY GIVEN CAP...BUT HIGH-BASED -TSRA POSSIBLE GIVEN STRONG
HEATING EXPECTED TODAY IN WESTERN SD AND MORE VIGOROUS TSRA
POSSIBLE IN THE EAST WHERE BETTER MOISTURE LIES. WILL LEAVE POPS
ALONE FOR NOW.
&&
.AVIATION...18Z TAFS
THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS MUCH OF
WESTERN AND CENTRAL SD THIS AFTERNOON AND EVENING. IF STORMS
DEVELOP...A FEW COULD PRODUCE HAIL AND STRONG WIND GUSTS...MAINLY
ACROSS THE PLAINS NORTH AND EAST OF THE BLACK HILLS. OTHERWISE VFR
CONDITIONS ARE EXPECTED THROUGH FRIDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 332 AM MDT THU JUL 19 2012/
TODAY THROUGH SATURDAY NIGHT
MASSIVE CENTRAL CONUS RIDGE WILL REMAIN ANCHORED IN PLACE WITH
ANOMALOUSLY LOW MID LEVEL HEIGHTS CONTINUING OVER THE PAC NW. DEEP
SOUTHERLY FLOW BETWEEN THE TWO AFOREMENTIONED SYSTEMS CONTINUES TO
SUPPORT THE ADVECTION OF MID LEVEL MONSOON MOISTURE INTO THE
ROCKIES...WITH NUMEROUS SMALL SCALE IMPULSES BEING EMBEDDED IN THE
FLOW. MEANWHILE A RATHER STRONGER NORTHERN STREAM UPPER TROUGH
CONTINUES TO DIVE SE INTO THE CANADIAN PRAIRIE PROVINCES ON THE
RIDGE PERIPHERY AS THE LINGERING BAJA UPPER VORT MAX EJECTS INTO THE
WESTERN CENTRAL ROCKIES. BOTH OF THESE FEATURES WILL BE PARAMOUNT TO
SENSIBLE WEATHER IN THE PERIOD...AS WELL AS THE STAUNCH THERMAL
RIDGE IN PLACE.
TODAY...THE AFOREMENTIONED NORTHERN STREAM IMPULSE WILL ADVECT ESE
AROUND THE RIDGE PERIPHERY...WITH MODERATE REFLECTED SOUTHERLY FLOW
AHEAD OF THIS FEATURE SUPPORTING CONTINUED LL THETA-E RIDGING AND
ASSOCIATED WAA. VERY WARM TEMPERATURES ARE EXPECTED ACROSS THE FA AS
H85 T/S ARE PROGGED IN THE LOW 30S C. RAP ANALYSIS HIGHLIGHTS A
DECENT AMOUNT OF THETA-E AT H7 WITH RIDGING CONTINUING THERE.
REFLECTED LL TROUGH FROM THE ADVECTING UPPER IMPULSE WILL ADVANCE
EAST THROUGH THE FA TODAY...SUPPORTING INCREASED LOCAL CONVERGENCE
AND MOISTURE POOLING ALL IN THE PRESENCE OF INCREASING LARGE SCALE
ASCENT. THIS SUGGESTS THE POTENTIAL OF CONVECTIVE INITIATION...WHICH
COULD CERTAINLY BE AIDED BY THE BLACK HILLS. EML PLUME WOULD
CERTAINLY SUPPORT THE POTENTIAL FOR INITIAL HIGH BASED CONVECTION
OVER SW AREAS WITH THE ADVANCING H7 TROUGH...BEING AIDED BY DEEP
DIURNAL MIXING. AMPLE LINGERING LL MOISTURE /WHICH WILL MIX OUT TO A
POINT/ WILL BE PRESENT ACROSS THE EASTERN THIRD OF THE FA...ESP
SCENTRAL SD...SUPPORTING THE POTENTIAL FOR BETTER COVERAGE AND
ROBUSTNESS OF CONVECTION. HENCE...HAVE EXPANDED POPS THIS AFTERNOON.
IF CONVECTION DOES DEVELOP AND BECOME ROOTED IN THE DEEPER MOISTURE
IN THE FAR EASTERN FA...THE POTENTIAL WILL EXIST FOR SEVERE CELLS
GIVEN MLCAPES IN EXCESS OF 2 KJ/KG. BULK DEEP LAYER SHEAR IS PROGGED
AT MARGINAL VALUES...BUT ENOUGH COULD CERTAINLY BE PRESENT FOR SOME
CELL ORGANIZATION. MAIN CONCERN WOULD BE DAMAGING WINDS. THE OTHER
CONCERN WILL BE THE HEAT. TEMPS ARE EXPECTED TO APPROACH RECORDS AT
MANY LOCATIONS...WITH HEAT INDEX READINGS IN THE LOW 100S. ANY TS
ACTIVITY WILL EXIT THE FA OVERNIGHT...WITH WARM OVERNIGHT LOWS 65 TO
75 EXPECTED.
FRIDAY-SATURDAY...NORTHERN STREAM RIDGE PERIPHERY IMPULSE WILL
DEPART THE REGION...ORPHANING A SFC BOUNDARY INTO THE FA...MAKING
FOR A TRICKY FORECAST. BASICALLY BLANKETED THE ENTIRE FA WITH POPS
THROUGH MOST OF THE PERIOD...ESP GIVEN AMPLE LL MOISTURE IN PLACE
WITH A MID LEVEL MONSOON CONNECTION/DISTURBED WESTERLY FLOW WITH THE
ARRIVAL OF THE MORE ROBUST CENTRAL ROCKIES UPPER TROUGH/AND AN
EASTERLY UPSLOPE FLOW REGIME. H7 THETA-E FIELDS SUGGEST SUBSTANTIAL
THETA-ADV AND MOISTURE POOLING OVER THE REGION FRIDAY AFTERNOON AND
EVENING WITH INCREASING CHANCES FOR STORMS. STORM CHANCES WILL
CONTINUE INTO SAT WITH DEEP LAYER MOISTURE REMAINING ACROSS MOST OF
THE AREA IN THE PRESENCE OF ANOTHER ADVANCING IMPULSE. RETAINED
HIGHER NUMBERS OVER THE HILLS WHERE HIGH LOCAL INSTABILITY CONTINUES
TO BE PROGGED. SUFFICIENT DEEP LAYER SHEAR/LL MOISTURE AND
ASSOCIATED CAPE WILL BE IN PLACE ACROSS THE FA /ESP NORTHERN
AREAS/...INCREASING THE THREAT FOR SEVERE THUNDERSTORMS. WILL
HIGHLIGHT IN THE HWO. TEMPS WILL BECOME TRICKY GIVEN POTENTIAL
CLOUDS/RAIN/AND NE LL FLOW. WITH THE SFC LOW EXPECTED TO BE OVER SW
SD...HAVE TRENDED TEMPS DOWN ACROSS THE NORTH SOME IN LINE WITH
MOS/MODEL TRENDS...RETAINING WARM NUMBERS OVER SCENTRAL SD BOTH DAYS.
EXTENDED...STRONG UPPER LEVEL RIDGING WILL DOMINATE OVER THE PLAINS
THROUGH MUCH OF THE EXTENDED FORECAST PERIOD. WEST TO SOUTHWEST FLOW
AROUND THE BACK SIDE OF THE RIDGE WILL PERSIST ACROSS THE FORECAST
AREA. THIS WILL BRING DAILY CHANCES FOR THUNDERSTORMS ACROSS A GOOD
PORTION OF THE CWA AS WEAK DISTURBANCES CROSS THE REGION. ABOVE
AVERAGE TEMPERATURES WILL ALSO CONTINUE INTO EARLY NEXT WEEK WITH
HIGHS IN THE 90S TO AROUND 100 ACROSS THE PLAINS. A STRONG SHORTWAVE
SYSTEM IS PROGGED TO MOVE ACROSS SOUTHWESTERN CANADA AND THE
SOUTHERN PRAIRIE PROVINCES TUESDAY AND WEDNESDAY. THIS WOULD WEAKEN
THE RIDGE AND PUSH IT FURTHER SOUTH ACROSS THE PLAINS DURING
MIDWEEK...DROPPING TEMPERATURES A BIT CLOSER TO AVERAGE ON WEDNESDAY
AND ESPECIALLY ON THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...HEAT ADVISORY UNTIL MIDNIGHT MDT /1 AM CDT/ FRIDAY NIGHT FOR
BENNETT-BUTTE-CUSTER CO PLAINS-FALL RIVER-HAAKON-HARDING-
HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID
CITY-SHANNON-SOUTHERN FOOT HILLS-SOUTHERN MEADE CO PLAINS-
STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...WFO UNR
AVIATION...13
UPDATE...WFO UNR
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
155 PM EDT THU JUL 19 2012
.AVIATION...
FOCUS WILL BE ON AFTERNOON PERIOD WITH POTENTIAL FOR CONVECTIVE
DEVELOPMENT AT BOTH SITES. GIVEN PROXIMITY OF SFC LOW...BETTER
CHANCE WILL EXIST AT KFWA WITH JUST AN OUTSIDE CHANCE AT KSBN.
PREV ISSUANCE/AMENDMENTS ALREADY HAVE THIS IN HAND SO NO CHANGES
WERE REQUIRED. LARGE AREA OF MVFR OR LOWER CIGS EXPECTED AT BOTH
SITES FROM COMBINATION OF STRATUS ALREADY MOVING IN BEHIND THE LOW
AND ADDITIONAL DEVELOPMENT IN AREAS OF CLEARING AS A RESULT OF
MOIST BL FROM RECENT RAINFALL. HAVE BROUGHT CIGS DOWN TO 1000 FT
AND MAY NEED TO LWR FURTHER IN LATER ISSUANCES. WINDS WILL COME
AROUND TO THE NE IN THE WAKE OF THE LOW AND REMAIN AROUND 10 KTS.
&&
.UPDATE...
GRIDS BEING UPDATED TO PUSH STEADY RAINFALL OUT OF THE FORECAST
AND FOCUS ON CONVECTIVE POTENTIAL THIS AFTERNOON.
WEAK SFC LOW WAS LOCATED NORTH OF CHAMPAIGN IL AS OF 1 PM EDT.
CLOUD COVER AHEAD OF IT CONTINUES TO SCOUR OUT WITH HEATING
UNDERWAY ACROSS THE WESTERN PARTS OF THE AREA. STRATUS DECK NORTH
OF THE LOW HAS UNDERWENT SOME BREAKDOWN WITH MORE OF A STRATOCU
APPEARANCE...INDICATING AMOUNT OF INCREASING INSTABILITY IN THESE
AREAS. HRRR 13Z RUN DEVELOPS CONVECTION RAPIDLY OVER THE NEXT
COUPLE OF HOURS JUST AHEAD OF THE LOW AND TRACKS SOUTH OF US 30.
SOME QUESTIONS REMAINS AS TO EXACTLY HOW THIS EVOLVE AND THE
TIMING WITH DESTABILIZATION STILL UNDERWAY AND LINGERING PATCHES
OF CLOUDS AROUND TO SLOW THIS PROCESS SOMEWHAT.
REGARDLESS...POTENTIAL EXISTS FOR STG-SVR STORMS IN THE ABOVE
MENTIONED AREA. RECENT SWODY1 CONFINED RISK TO FAR SOUTHERN TIER
OF COUNTIES /SOUTH OF US 24/. HWO KEEPS THREAT A BIT FURTHER NORTH
THAN THIS BUT AS NOTED IS CONTINGENT ON INITIATION AND INSTABILITY
MATERIALIZING.
&&
.PREV DISCUSSION... /ISSUED 1054 AM EDT THU JUL 19 2012/
UPDATE...
LARGE AREA OF MUCH NEEDED RAIN AND EMBEDDED STORMS WILL CONTINUE
TO DRIFT EAST OUT OF THE AREA THROUGH NOON. CLEARING SKIES ACROSS
ILLINOIS SHOULD EDGE INTO AT LEAST W/SW AREAS ALLOWING FOR SOME
HEATING TO TAKE PLACE. WEAK SFC LOW WAS LOCATED OVER EASTERN IOWA
THIS MORNING AND WILL DRIFT EAST THIS AFTERNOON. A LARGE AREA OF
STRATUS WAS DROPPING SOUTH BEHIND THE COLD FRONT WHICH MAY PUT AN
END TO RAIN CHANCES IN NORTHERN AREAS AND ALSO KEEP TEMPERATURES
FROM CLIMBING MUCH. FOR THE TIME BEING...AFTERNOON GRIDS REFLECT
LOW END CHC POPS NORTH TO NUMEROUS SHOWERS GENERALLY ALONG AND
SOUTH OF US 24. RECENT SWODY1 OUTLOOK PULLED MUCH OF THE AREA OUT
OF SLGT RISK. WHILE OVERALL RISK MAY BE REDUCED
SOMEWHAT...THREAT FOR DAMAGING WINDS AND LARGE HAIL WILL STILL
EXIST THIS AFTERNOON/EVE. GREATEST THREAT WILL BE IN LOCATIONS
THAT SEE HEATING OVER THE NEXT SEVERAL HOURS.
GIVEN ABOVE ISSUES...HAVE LOWERED HIGH TEMPS ACROSS THE BOARD 3 TO
5 DEGREES WITH ADDITIONAL CHANGES LIKELY WITH TIME AS CLEARING
TREND BECOMES ESTABLISHED.
PREV DISCUSSION... /ISSUED 402 AM EDT THU JUL 19 2012/
SHORT TERM...
TODAY AND TONIGHT...
ONGOING CONVECTION ASSOCIATED WITH THE MCS WILL PERSIST THROUGH
THE MORNING. SFC FRONT/TROF AXIS EXTENDS FROM LOWER LAKE MI
THROUGH KANSAS CITY...AND THIS APPEARS TO BE THE MAIN FOCUS OF THE
CURRENT CONVECTIVE COMPLEX.
IN THIS PERIOD...MODELS APPEAR TO HAVE CAPTURED THE APPROXIMATE
INTENSITY AND ORIENTATION OF THE CURRENT CONVECTION...HOWEVER NONE
HAVE THE TIMING AND PLACEMENT CORRECT. ALL THE MODELS APPEAR TO BE
3 TO 9 HOURS TOO SLOW. WITH THIS IN MIND...TOOK A BLEND OF MODELS
AND SHIFTED GRIDS FORWARD A FEW HOURS.
LOW LEVEL FLOW IS FAVORABLE FOR REDEVELOPMENT OF THUNDERSTORMS
ACROSS THE SOUTHERN HALF OF THE CWA TODAY AND EXPECT TO SEE
SIMILAR PULSE TYPE AND OCCASIONAL BOWING SEGMENTS. THE BOUNDARY
LAYER STILL FAVORS OUTFLOW BOUNDARY INTERACTION. FREEZING LEVEL IS
LOWER TODAY THAN IN THE PAST FEW DAYS...AND THIS WOULD FAVOR
ISOLATED HAIL THREAT. LIMITED SHEAR AND THIS WOULD FAVOR LOCALLY
HEAVY RAINFALL AS WELL.
EXPECT COOLER AND DRYER CONDITIONS TO SPREAD CWA-WIDE FRIDAY AND
FRIDAY NIGHT.
LONG TERM / SATURDAY THROUGH WEDNESDAY /...
GIVEN ONGOING SEVERE WEATHER EVENT...NO MAJOR CHANGES TO ONGOING
GRIDS AND WILL STAY THE COURSE WITH DRY FORECAST THRU MIDWEEK. RIDGE
WILL BEGIN TO BUILD BACK IN ON SATURDAY AND REMAIN CENTERED OVER THE
CENTRAL PLAINS INTO NEXT WEEK. ACTIVE W/NWESTERLY FLOW WILL ALLOW
FOR SEVERAL RIDGE TOPPING DISTURBANCE BUT MODELS STILL DIFFER ON
TIMING AND HOW FAR SE EACH WILL PROPAGATE. BEST CHANCE AT ANY PRECIP
LOOKS TO BE IN TUES/WEDS TIMEFRAME AS RIDGE FLATTENS AND SEMI
STATIONARY FRONTAL BOUNDARY BECOMES DRAPED NEAR THE AREA. COULD SEE
THE POSSIBILITY OF HAVING TO ADD LOW POPS IN THE FUTURE BUT WILL
REMAIN WITH DRY FORECAST GIVEN ONGOING DROUGHT CONDITIONS AND
TENDENCY OF MODELS TO OVERDO MOISTURE FIELDS IN THIS TYPE OF PATTERN.
THERMAL RIDGE WILL BUILD EASTWARD OVER THE REGION WITH TEMPS RISING
BACK INTO THE 90S BY SUNDAY. MID TO UPPER 90S NOT OUT OF THE
QUESTION BY END OF THE PERIOD BUT TEMPS WILL HINGE ON ANY CLOUD
COVER AND PRECIP FROM DISTURBANCES RIDING THE RIDGE. HAVE CONTINUED
TREND OF GOING ABOVE GUIDANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LEWIS
LONG TERM...OBERGFELL
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS WICHITA KS
348 PM CDT THU JUL 19 2012
.DISCUSSION...
ISOLATED SHOWERS AND THUNDERSTORMS WITH A THREAT FOR WIND GUSTS TO
55 MPH MAY LINGER THROUGH THE EARLY EVENING HOURS BEFORE DRIFTING
SOUTH/DIMINISHING IN THE ABSENCE OF HEATING.
A MORE SUBSIDENT REGIME IS ANTICIPATED OVER THE WEEKEND AS THE H5
RIDGE EXPANDS ACROSS THE CENTRAL PLAINS. THE H85-H7 THERMAL
RIDGE/INCREASE IN THICKNESS CONTINUES TO SUPPORT RISING TEMPERATURES
WITH VALUES IN THE 105-109 DEGREE RANGE ANTICIPATED. DEEP VERTICAL
MIXING WILL ALLOW DEWPOINT TEMPERATURES TO PLUMMET DURING THE
AFTERNOON HOURS BUT HEAT INDICES WILL STILL MANAGE TO CLIMB TO
AROUND 105+ DEGREES AT TIMES. THEREFORE THE HEAT ADVISORY WILL BE
EXPANDED THROUGH TUESDAY.
WED-THU...ALTHOUGH TEMPERATURES ARE EXPECTED TO REMAIN WELL ABOVE
NORMAL/POSSIBLY LINGERING IN THE 100-105 DEGREE RANGE THERE MAY BE A
TEMPORARY BREAK DOWN OF THE MID/UPPER RIDGE TOWARD THE MIDDLE OF THE
WEEK AS A ROBUST MID/UPPER TROUGH TRANSLATES EAST ALONG THE
US/CANADIAN BORDER. IF THE RIDGE DOES TEMPORARILY BREAK DOWN IT MAY
BE FAIRLY SHORT-LIVED SO ONLY A SUBTLE TREND DOWN IN TEMPERATURES
WAS INTRODUCED ON THU.
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
TOUGH CONVECTIVE FORECAST. STORMS HAVE LINGERED ALONG A COUPLE OF
WEAK BOUNDARIES AND OUTFLOW FROM EARLIER STORMS. LATEST RUC
SEEMS HAVE BETTER HANDLE ON THE CURRENT OBSERVATIONS AND VERY SHORT
TERM TRENDS THAN OTHER GUIDANCE. THIS KEEPS BOUNDARY NORTH OF
KICT/KCNU THROUGH AT LEAST EARLY EVENING AND THEN WILL BLEND INTO
NAM AS BOUNDARY SAGS SOUTH DURING THE NIGHT. OF NOTE RUC SHUTS
DOWN MOST OF THE PRECIPITATION BY 2100 UTC. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 75 106 75 105 / 20 10 10 0
HUTCHINSON 76 105 75 103 / 20 10 10 0
NEWTON 78 104 78 103 / 20 10 10 0
ELDORADO 76 104 76 102 / 20 10 0 0
WINFIELD-KWLD 78 107 78 105 / 30 10 10 0
RUSSELL 71 105 71 107 / 10 0 10 0
GREAT BEND 73 105 72 106 / 10 10 10 0
SALINA 74 105 74 105 / 10 10 10 0
MCPHERSON 72 104 73 104 / 20 10 10 0
COFFEYVILLE 78 104 78 103 / 30 10 10 10
CHANUTE 77 101 76 100 / 20 10 10 10
IOLA 75 100 76 101 / 20 10 10 10
PARSONS-KPPF 77 102 77 102 / 30 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR KSZ032-033-047>053-
067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1235 PM CDT THU JUL 19 2012
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
TOUGH CONVECTIVE FORECAST. STORMS HAVE LINGERED ALONG A COUPLE OF
WEAK BOUNDARIES AND OUTFLOW FROM EARLIER STORMS. LATEST RUC
SEEMS HAVE BETTER HANDLE ON THE CURRENT OBSERVATIONS AND VERY SHORT
TERM TRENDS THAN OTHER GUIDANCE. THIS KEEPS BOUNDARY NORTH OF
KICT/KCNU THROUGH AT LEAST EARLY EVENING AND THEN WILL BLEND INTO
NAM AS BOUNDARY SAGS SOUTH DURING THE NIGHT. OF NOTE RUC SHUTS
DOWN MOST OF THE PRECIPITATION BY 2100 UTC. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT THU JUL 19 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
A FEW CLUSTERS OF THUNDERSTORMS WILL AFFECT EASTERN/SOUTHEAST
KANSAS THIS MORNING...WITH KCNU LIKELY DIRECTLY AFFECTED THROUGH
AT LEAST 14-15Z...IF NOT LATER. MAIN HAZARDS WILL BE
LIGHTNING...LOCALLY HEAVY DOWNPOURS AND ERRATIC & GUSTY WINDS
IN/NEAR THUNDERSTORMS. BY MID-AFTERNOON...ISOLATED HIT-AND-MISS
THUNDERSTORMS WILL BE POSSIBLE OVER SOUTHERN KS ALONG A NEARLY
STALLED FRONTAL BOUNDARY. INSERTED VCSH FOR KHUT-KICT-KCNU AFTER
20Z AS ACTIVITY WILL LIKELY BE QUITE ISOLATED...ALTHOUGH LATER
SHIFTS MAY NEED TO EVENTUALLY UPGRADE TO VCTS. STALLED BOUNDARY
STRADDLING SOUTHERN KS WILL MAKE WIND FORECASTING CHALLENGING AT
KHUT-KICT-KCNU...WITH NORTHEAST WINDS NORTH OF THE BOUNDARY AND
SOUTH/SOUTHWEST WINDS SOUTH OF THE BOUNDARY.
KLEINSASSER
PREV DISCUSSION... /ISSUED 320 AM CDT THU JUL 19 2012/
DISCUSSION...
MAIN FORECAST CONCERNS WILL BE CONTINUED HOT AND DRY CONDITIONS FOR
MOST LOCATIONS. WITH SOME POSSIBLE ISOLATED STORMS FOR AREAS EAST OF
THE FLINT HILLS LATE THIS AFTERNOON.
TODAY-TONIGHT:
A WEAK PV-ANOMALY CONTINUES TO PUSH GRADUALLY SOUTHEAST EARLY
TODAY...WITH SOME FESTERING SHOWERS/STORMS OVER NORTHEAST KS. NOT
EXPECTING THIS FESTERING ACTIVITY TO MAKE INTO SOUTHEAST KS THIS
MORNING...PROBABLY WANING A LITTLE AFTER SUNRISE. BUT SHORT TERM
MODELS SUGGEST THAT A BACKDOOR SOUTHWEST MOVING FRONTAL BOUNDARY
WILL DROP INTO SOUTHEAST KS BY THIS AFTERNOON. WARM TEMPS ALOFT WILL
KEEP WIDESPREAD DEEP MOISTURE CONVECTION FROM LIGHTING UP ALONG THIS
BOUNDARY...BUT THINK AN ISOLATED STORM CHANCE LOOKS WARRANTED LATE
THIS AFTERNOON/EARLY THIS EVENING AS THE WEAK CONVERGENCE INCREASE
INSTABILITY SOME WITH LIFT PROVIDED FROM THIS ANOMALY AS IT DRIFTS
ACROSS SOUTHEAST KS. SO WILL PLACE A LOW POP IN FOR THIS CHANCE FOR
AREAS EAST OF THE FLINT HILLS LATE THIS AFTERNOON INTO THIS EVE.
NEXT CONCERN WILL BE THE CONTINUED HEAT WAVE ACROSS MOST OF THE
PLAINS. EXPECTING MAX TEMPS TODAY JUST AS HOT AS YESTERDAY...AS SFC
WINDS JUST TO THE SOUTHWEST OF THE BOUNDARY MIX OUT DWPTS ACROSS
SOUTH CENTRAL KS. THIS WILL LEAD TO MAX TEMPS AGAIN AROUND 105 FOR
KICT/KRSL AND KGBD. THE BIGGER CONCERN TODAY...WILL BE INCREASED SFC
DEWPOINTS POOLING JUST SOUTH AND WEST OF THE BOUNDARY AS IT DRIFTS
TO A POSITION FROM NEAR KCNU TO KSLN. THE SOMEWHAT HIGHER DWPTS WILL
LEAD TO HEAT INDEX VALUES OF 105 TO 108 TODAY. SO CURRENT HEAT
ADVISORY CERTAINLY LOOKS FINE...AS TODAY WILL FEEL MORE HUMID AND
HOT.
FRI-WED:
THE MAIN STORY FOR THE WEEKEND INTO THE BEGINNING OF NEXT WEEK WILL
BE THE CONTINUED STIFLING HEAT. PERSISTENT UPPER RIDGE CURRENTLY
OVER THE PLAINS...WILL CONTINUE FOR THE WEEKEND INTO THE BEGINNING
OF THE WEEK. WILL KEEP WITH A PERSISTENCE-TYPE FORECAST WITH THE
PATTERN LOOKING LIKE IT WILL STAY AROUND WITH HIGHS IN THE 100-105
RANGE AND MINIMAL CHANCES FOR PRECIP. MEDIUM RANGE MODELS DO SUGGEST
THAT THIS UPPER RIDGE MAY FLATTEN OUT SOME FOR TUE OR WED OF NEXT
WEEK...BUT ENSEMBLE MEANS HOLD THE RIDGE IN STRONG. SO UNTIL RIDGE
SHOWS DEFINITE SIGNS OF BREAKING DOWN...WILL KEEP BANGING THE HOT
AND DRY DRUM. NOT GONNA MESS WITH THE CURRENT HEAT ADVISORY
CURRENTLY IN EFFECT UNTIL SUN...AS THIS LOOKS GOOD. BUT THE
PROLONGED HEAT BY THE WEEKEND...MAY TIP US OVER INTO AN EXCESSIVE
HEAT SITUATION.
KETCHAM
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
TERMINALS DRAWING GREATEST ATTENTION ARE KSLN & KRSL WHERE SCT TSRA
CAPABLE OF 35-40KT GUSTS CONTINUE TO FESTER ALONG AN E-W ORIENTED
FRONT. A FEW CELLS MAY FESTER OVER THESE AREAS TIL ~07Z. AS SUCH MAY
ASSIGN "VCTS" TO BOTH TERMINALS DURING FIRST HOUR OF THE TAF. WITH THE
FRONT IN THESE AREAS WIND DIRECTIONS ARE LIKELY TO BE VARIABLE FOR THE
REST OF THE NGT/EARLY THU MORNING. OTHERWISE ALL 5 TERMINALS TO REMAIN
IN VFR STATUS FOR DURATION OF 06Z TAF CYCLE. ~ES
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 105 76 106 77 / 20 20 10 10
HUTCHINSON 105 77 104 76 / 20 20 10 10
NEWTON 104 79 103 77 / 20 20 10 10
ELDORADO 104 77 104 76 / 50 20 10 10
WINFIELD-KWLD 104 79 107 78 / 20 20 10 10
RUSSELL 105 72 106 75 / 10 10 0 10
GREAT BEND 105 74 106 75 / 10 10 10 10
SALINA 106 75 105 77 / 10 10 10 10
MCPHERSON 105 73 104 77 / 10 10 10 10
COFFEYVILLE 104 79 103 77 / 50 20 10 10
CHANUTE 102 78 100 76 / 70 20 10 10
IOLA 102 76 100 76 / 70 20 10 10
PARSONS-KPPF 103 78 102 77 / 50 20 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR KSZ032-033-047>053-
067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
135 PM EDT THU JUL 19 2012
...Updated Aviation Discussion...
.Forecast Update...
Issued at 1023 AM EDT Thu Jul 19 2012
Updated the forecast to refresh grids with latest hourly data and
increase POPs to 50% quicker this morning. Already have storms
firing over the area in a warm soupy airmass. A couple different
boundaries were noted over central IN/OH moving southward this
morning. One of note was rather a lengthy boundary stretching from
western Ohio to southern Indiana to southern IL to southeast MO.
These boundaries will play a crucial role providing a focus for
convective initiation/location today. They`ve already sparked
storms near Jefferson Co, IN and Trimble Co, KY. The HRRR model
seems to be handling convection the best this morning and for the
past several days. According to the latest 10Z run, we should see 2
or 3 notable rounds of convection today. At least one during the
early afternoon hours and another this evening. There could be a
third round in between or possibly late this evening.
&&
.Short Term (Today - Friday)...
Issued at 316 AM EDT Thu Jul 19 2012
...Hot and Humid Followed by Another Round of Strong to Severe
Storms Today...
Current radar imagery shows convective complex that had looked
impressive over southeast Indiana earlier falling apart as it moves
into our less favorable environment. Will continue mention of
diminishing coverage of showers and storms across southeast IN to
the Bluegrass through dawn. Elsewhere, cannot rule out an isolated
shower or storm with moist airmass still in place and remnant
outflow boundaries wandering around.
We`ll set the stage for another hot and humid day as current IR
satellite shows heavy sky cover is rapidly diminishing from earlier
storms. This will likely lead to mostly clear to partly cloudy skies
by dawn and solid heating potential through at least the early
afternoon. As has been the case, temperatures are expected to
quickly rise into the solid mid 90s by early afternoon along and
west of I-65. These temperatures combined with dew points in the
lower 70s will result in heat indices peaking just above 105 degrees
for a few hours this afternoon. Have issued a Heat Advisory along
and west of I-65 to account for this. Further east, heat indices are
expected to max out in the 100-105 range and will likely issue a
special weather statement to highlight.
A look at current water vapor imagery shows a shortwave over the
upper Midwest with an associated surface low currently near the
confluence of SE Iowa, W Illinois, and NE Missouri. The surface low
is expected to move to central Indiana by this evening with
increasing deep layer flow/lift ahead of the positively tilted
shortwave. Coverage of thunderstorms is expected to increase through
the day with numerous storms by late this afternoon and evening. Our
airmass will be strongly unstable (CAPE values between 2500-3500
J/KG suggested by forecast soundings) and with the increasing deep
layer shear, better storm organization in the form of multicells and
forward propagating segments are anticipated. The main threats from
these storms will continue to be torrential rainfall, excessive
cloud to ground lightning and damaging winds. Could also see some
hail in the stronger storms. At this point, the best timing looks to
be from 3 PM to 11 PM EDT.
Scattered to numerous storm coverage will continue through the
evening and overnight hours as surface low drags a cold front to our
doorstep and trough axis remains just to our NW. Best coverage
should be in the east CWA.
Will see chances for showers and storms diminishing from northwest
to southeast through the day on Friday as cold front and trough axis
move through the region. High temperatures are tricky in this
convective and advective pattern, however a noticeable "cool" down
into the upper 80s and low 90s is on tap.
.Long Term (Friday night through Wednesday)...
Issued at 254 AM EDT Thu Jul 19 2012
The upper trof overhead at the start of the long term will weaken
and lift out of the region over the course of Friday night and
Saturday, and will be replaced by upper ridging stretching from the
Plains to the Atlantic through early in the new week with the Ohio
and Tennessee Valleys in a saddle between mounds of high pressure to
our west and east. By mid week the ridge will sink south towards
the Gulf. Since we won`t be right under the heart of the ridge
during this time, we will escape extreme heat and will not be able
to rule out scattered diurnal thunderstorm development -- both good
things for our drought-weary region.
As is typical for this time of year, surface features are weak and
amorphous. It looks like, though, the weak cool front that came
through the area in the short term will sag slowly south of Kentucky
Friday night/Saturday. High pressure to our southeast will weakly
try to build in by Monday, but then another weak cool front will
approach from the northwest during the Tuesday/Wednesday time frame.
The best chances for rain will be in the form of scattered storms
that can pop in the heat of the afternoon over southern Kentucky
Saturday-Monday, and then hopefully more widespread coverage
throughout the region by Wednesday as that front comes in from the
northwest.
High temperatures over the weekend look to be in the upper 80s and
lower 90s, and then in the lower and middle 90s for Monday through
Wednesday...with dew points in the upper 60s to lower 70s. Lows
will be around 70 Saturday morning and in the lower and middle 70s
for the rest of the long term.
&&
.Aviation (18Z TAF Issuance)...
Issued at 130 PM EDT Thu Jul 19 2012
An upper level trough moving through the area as well as multiple
sfc boundaries will cause on and off chances of t-storms this
afternoon and tonight. According to the latest 12Z NAM and 13Z HRRR
models, scattered convection near SDF/LEX looks likely this
afternoon with t-storm chances increasing this evening at BWG. It
is hard to nail down timing of storms and have left VCTS in for a
good period this afternoon and evening. Will need to refine reduced
flight conditions (MVFR or IFR) and winds as t-storms approach the
TAF sites. Outside of any t-storms late this afternoon/evening, sfc
winds will become gusty out of the SW on approach of the main upper
level trough and sfc front. The best chance of widespread storms
looks to be associated with these features between 0Z and 6Z this
evening.
After 6Z to 9Z storms should exit the TAF sites with lingering
showers possible. NAM soundings and MOS guidance indicates low cigs
(MVFR) moving in behind the main convection lasting through the
morning hours. The main wind shift (WSW to NW) with the main sfc
front will occur near the very end of this TAF period between
15-19Z tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 10 PM EDT /9 PM CDT/ THIS EVENING FOR
INZ076>079-083-084-089>092.
KY...HEAT ADVISORY UNTIL 10 PM EDT /9 PM CDT/ THIS EVENING FOR
KYZ023>032-061-062-070>072.
$$
Update...........AMS
Short Term.......BJS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
324 PM EDT THU JUL 19 2012
.SYNOPSIS...
A COLD FRONT WILL INCH SOUTH ACROSS THE REGION TONIGHT. LOW
PRESSURE WILL DEVELOP ALONG THE STATIONARY FRONT TO OUR SOUTH
FRIDAY...CONTINUING A PERIOD OF ACTIVE WEATHER THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
LEE TROUGH EXTENDS FROM SRN NJ TO THE NC PIEDMONT PER 18Z RAP SFC
ANALYSIS. ISOLATED THUNDERSTORMS WRN SHORE OF THE BAY NORTH OF
ANNAPOLIS...WITH SCATTERED THUNDERSTORMS DEVELOPING IN THE LEE OF
THE ALLEGHENY FRONT. THROUGH 4PM EXPECT MORE DEVELOPMENT IN SRN MD
AND N-CNTRL MD.
AS OF 19Z...WIDE SWATH OF STRONG-NOT-SEVERE THUNDERSTORMS AHEAD OF A
WEAK SFC LOW STRETCH FROM WRN PA TO NERN KY IS SLOWLY SHIFTING
EAST...ON TRACK TO PUSH EAST OF THE ALLEGHENY FRONT BY 6PM. WHAT
WILL HAPPEN EAST FROM THERE IS MORE UNCERTAIN. INTENSITY WILL
CERTAINLY DIMINISH UPON CROSSING THE APPALACHIANS. MODERATE CAPE OF
1000-2000 J/KG SHOULD ALLOW AT LEAST SCATTERED ACTIVITY TO BE
MAINTAINED AS IT SHIFTS EAST. BEST GUESS RIGHT NOW IS FOR SCATTERED
THUNDERSTORMS ACROSS THE BALT-WASH METRO IN THE 9PM TO MIDNIGHT
TIMEFRAME /WITH ISOLATED TO SCATTERED STORMS ACROSS BALTIMORE LATE
THIS AFTERNOON/.
TONIGHT...FRONTAL BOUNDARY STALLS OVER THE AREA IN THE WAKE OF THE
APPROACHING SFC LOW. EXPECT ONGOING SHOWERS AND THUNDERSTORMS
THROUGH THE NIGHT PARTICULARLY FOR NRN SECTIONS OF THE CWA WHERE
UPPER DYNAMICS ARE BETTER WITH AN APPROACHING SHORTWAVE. THERE IS
ABUNDANT MOISTURE WITH PWATS WITH SATELLITE DERIVED BLENDED TOTAL
PWATS RIGHT AROUND 2 INCHES. THE PRESENCE OF MESOSCALE BOUNDARIES
FROM THIS AFTERNOON CONVECTION AND A LOW MOVING PERPENDICULAR TO
THEM COULD CAUSE LOCALIZED FLASH FLOODING. SHOULD THREAT AREAS
BECOME BETTER DEFINED...EVENING SHIFT MAY CONSIDER A FLASH FLOOD
WATCH. MIN TEMPS LOW TO MID 70S...UPR 70S URBAN.
FRIDAY...SECONDARY SFC LOW AHEAD OF A SHORTWAVE SHIFTS EAST ACROSS
THE CENTRAL MID ATLANTIC WITH PRECIP MOST OF THE DAY...WENT
CATEGORICAL FOR THE AFTERNOON CONSIDERING LOW PLACEMENT OVER CNTRAL
VA AND DIURNAL TRENDS. MAX TEMPS LOW TO MID 80S /UPR 80S SOUTH OF
LOW...INVOF KCHO/ UNDER CLOUDY SKIES AND PRECIP. PWATS REMAIN HIGH
SO BUMPED UP QPF TO IN EXCESS OF HALF AN INCH...LOCAL AMOUNTS OF 1-2
INCHES CERTAINLY POSSIBLE WITH AN ONSHORE FLOW NORTHEAST OF THE LOW
PROVIDING A GOOD MOISTURE FLUX.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
LOPRES PASSES S OF CWFA FRI EVE...PLACING AREA W/IN ZN OF STRONG
LLVL ONSHORE MARITIME FLOW. H8 FLOW WLY...MAKING FOR A GOOD
OVERRUNNING SETUP. PWAT AOA 2IN...EMPHASIZING PCPN POTL. AM CARRYING
CAT POPS NE OF HGR-DCA-XSA...BUT TRANSITIONING AWAY FM THUNDER TWD
RAIN DUE TO INCRSG MDL STABILITY.
THE CDFNT /MARKING THE TRANSITION BTWN STBL AND UNSTBL AIR/ REMAINS
ACRS CWFA SAT. GIVEN THE CONTD ELY FLOW INVOF A WK BNDRY...NEED TO
KEEP POPS IN THE FCST THRU THE DAY. HV SEPARATED THE S /TSRA/ FM THE
REST OF THE CWFA /-SHRA/. FM THE STANDPOINT OF PCPN PROCESSES...MAY
ALMOST BE ABLE TO MAKE AN ARGUMENT FOR -RA INSTEAD.
BNDRY SAGS SWD A PINCH SAT NGT...BUT STILL HV IMPULSES RIDING ALONG
IT. THEREFORE...NEED TO KEEP CHC SHRA RUNNING THRU ANOTHER NGT...
PRIMARILY CENTRAL VA AND SRN MD.
RDGG AND SLGTLY DRIER AIR BUMPS SWD SUN MRNG. BUT THERE/S STILL
MODEST INSTBY W/IN THE COLUMN /SUBZERO LI AND SVRL HND JOULES
CAPE/...WHICH SUGGESTS THAT DIURNAL ACTIVITY PSBL. THAT WUD DEPEND
ON CHARACTER OF H8-5 TROF AXIS...WHICH GDNC DRAWING A LTL SHAKY
ATTM. AM NOT SURE IF WE/D BE W/IN A SUBSIDENT RGN. HENCE...20-30 PCT
POPS /TSRA/ RTN FOR SUN AFTN.
THRUT THIS PD...MOS GDNC W/IN A CPL DEGREES OF EACH OTHER...AND
FAIRLY CONSISTENT WL GOING FCST. THEREFORE...HV BLENDED NEW GDNC IN
W/ A LTL BIT OF PRVS FCST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
H5 TROF AXIS PERSISTS ALONG EASTERN CONUS/ATLC COAST MON-TUE. AS
S/WV ENERGY DROPS INTO THE TROF AXIS MON NGT-TUE MRNG...IT/LL
PROVIDE THE FOCUS FOR MORE SHRA/TSRA. PRIMARILY DIURNAL SCHC/CHC
POPS THRUT.
HIPRES/SUBSIDENCE PROGGED TO BLD BHD THAT WED. IT/S STILL TBD
WHETHER THIS TIME THE FNT WL BE ABLE TO CLR AREA...OR IT TOO STALLS
OUT NEARBY. ATTM WL RUN OPTIMISTICALLY...PLACING A 36 HR DRY PD W/IN
DATABASE BEFORE WE CREEP BACK TWD CLIMO /20-30 PCT CHC TSTMS/ ON DAY
7.
PER TEMPS...MAXT LWR 90S...XCPT FOR UPR 80S WED BHD FNT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
A STATIONARY FRONT IS EXPECTED TO SETUP ACROSS THE CENTRAL MID
ATLANTIC TONIGHT AND PERSIST THROUGH FRIDAY. LOW PRESSURE MOVES EAST
ALONG THE FRONT ACROSS THE TERMINALS LATER FRIDAY. POTENTIAL FOR
HEAVY AND STRONG THUNDERSTORMS/IFR CONDS CONTINUES THIS EVENING
THROUGH FRIDAY.
MVFR TO LCL IFR W/IN MOSTLY WDLY SCT TSTMS. PCPN WL BE MOST PROLIFIC
/NMRS-DEF/ FRI NGT...WHEN CHARACTER WL BE TRANSITIONING TWD RAIN.
MOST OF THE TIME WL BE VFR THO. ELY MRNG BR ALSO A CONSIDERATION.
&&
.MARINE...
A STATIONARY FRONT IS EXPECTED TO SETUP ACROSS THE CENTRAL
CHESAPEAKE BAY REGION TONIGHT AND PERSIST THROUGH FRIDAY.
LOW PRESSURE MOVES EAST ALONG THE FRONT ACROSS THE WATERS LATER
FRIDAY. POTENTIAL FOR HEAVY AND STRONG THUNDERSTORMS/ AND SPECIAL
MARINE WARNINGS CONTINUES THIS EVENING THROUGH FRIDAY.
ELY FLOW AND A PASSING IMPULSE FRI NGT WL SUPPORT NMRS SHRA. BYD
THAT...A BNDRY WL BE STALLED NEARBY. SCHC/CHC TSRA DAILY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BAJ/HTS
NEAR TERM...BAJ
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...BAJ/HTS
MARINE...BAJ/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
104 PM EDT THU JUL 19 2012
.SYNOPSIS...
A LOW WILL CONTINUE TO APPROACH FROM THE MIDWEST THIS
AFTERNOON...AFFECTING THE MID ATLANTIC THIS EVENING INTO THE
OVERNIGHT. A STATIONARY FRONT IS THEN EXPECTED TO CONTINUE AN
ACTIVE WEATHER PERIOD THROUGH SATURDAY ACROSS THE AREA. HIGH
PRESSURE IS EXPECTED TO BUILD BY SUNDAY. A COLD FRONT WILL
APPROACH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DIFFUSE SFC TROUGH ROUGHLY FROM ATLANTIC CITY DOWN TO THE CAROLINA
PIEDMONT PER RAP SFC ANALYSIS...N-NWLY FLOW...AND ECHOES OFF SRN
JERSEY SHORE AND IN LEE OF BLUE RIDGE IN NC. IT WOULD SEEM ANY
PRECIP DEVELOPMENT OVER THE NEXT COUPLE OF HOURS ACROSS THE LWX
CWA WOULD BE ALONG THIS ZONE. HOWEVER...VIS SATELLITE IMAGERY IS
PRETTY ANEMIC THUS FAR FOR THE LWX CWA. THEREFORE REMOVED LIKELY
POPS FOR BALT-WASH UNTIL 6PM. MAIN FOCUS IS THE CONVECTIVE
CLUSTERS SHIFTING EAST ACROSS OHIO EARLY THIS AFTERNOON. TIME OF
ARRIVAL TOOL SUGGESTS THE CURRENT ACTIVITY CROSSES THE ALLEGHENY
FRONT AROUND 5PM. EXPECT SCATTERED THUNDERSTORMS TO DEVELOP AHEAD
OF THIS FEATURE THIS AFTERNOON FROM THE BLUE RIDGE AND WEST WITH
TERRAIN CIRCULATIONS BREAKING THE CAP.
MAX TEMPS ON TRACK FOR LOW 90S WITH ABUNDANT SUNSHINE FOR NRN VA
AND N-CNTRL MD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
INTERACTION OF APPROACHING S/W AND BOUNDARIES OVER THE AREA AND
WEAK SHEAR WILL LEAD TO LOCALLY ENHANCED RAINFALL AND POTENTIAL
FOR ISOLATED FLASH FLOODING THIS EVENING ACROSS THE LWX CWA.
MODERATE SBCAPE AROUND 2500 J/KG WILL ALLOW LOCALIZED SEVERE
ACTIVITY WITH DAMAGING WINDS AS MAIN THREAT. THUNDER THREAT
CONTINUES THROUGH TONIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AFTER ANOTHER LULL PERIOD OVERNIGHT TONIGHT INTO EARLY FRI...ANOTHER
SYSTEM WILL BE ON THE DOORSTEP. A STRENGTHENING UPPER VORT WILL
SLIDE DOWN FROM THE GREAT LAKES...TRUDGING ACROSS A BULK OF PA INTO
THE EARLY MRNG HRS FRI. AN ALSO STRENGTHENING BERMUDA HIGH WILL HALT
THE PROGRESS OF THIS UPPER WAVE UPON REACHING THE MID ATLC. A LIGHT
SLY FLOW FRI MRNG WILL KEEP DEWPOINTS RELATIVELY HIGH...WELL INTO
THE L70S - SO HUMIDITY WILL LINGER A BIT LONGER.
THE SFC LOW ASSOCIATED W/ THE INCOMING UPPER WAVE WILL MAKE ITS WAY
SEWD ACROSS THE CWA OVER THE COURSE OF THE MRNG/AFTN. NORTH OF
THE LOW...CONDITIONS WILL BE FAIRLY STABLE AND MUCH COOLER -
AROUND 10 DEGREES LOWER THAN THE PREVIOUS DAY. SOUTH OF THE
LOW...EVEN W/ MAINLY CLOUDY SKIES...TEMPS WILL RISE BACK INTO THE
80S/L90S AND CREATE AT LEAST MARGINAL INSTABILITY THAT WILL LIKELY
BE UTILIZED BY THE INCOMING SYSTEM. CONVECTIVE CHANCES DECREASE OF
THE COURSE OF THE DAY FROM NORTH-TO-SOUTH AS THE LOW TRACKS DOWN
ACROSS THE AREA. THE SRN TIER COUNTIES WILL HAVE THE HIGHEST
POTENTIAL FOR STRONG/SVR STORMS DURING THE DAYTIME HRS.
STABILIZING ONSHORE NELY FLOW WILL MOVE IN ACROSS NJ/DELMARVA AND
TURN ANY LINGERING TSTMS INTO A MORE GENERAL LIGHT-MODERATE RAIN
HEADING INTO THE NIGHTTIME HRS.
AN INTERESTING CHANGE OF PACE FROM THE TYPICAL WX PATTERNS WE`VE
SEEN OVER THE PAST SEVERAL WEEKS. W/ THE UPPER LOW SLOWING-DOWN OR
NEARLY STALLING OVER THE AREA FRI AND SAT...CREATING FAIRLY HIGH
RAIN CHANCES OVERNIGHT FRI INTO SAT. MOST OF THE TSTM ACTIVITY WILL
BE DISSIPATED BY THEN...BUT POCKETS OF RAIN WILL LIKELY CONTINUE
INTO SAT MRNG.
MUCH OF THE FORCING THAT CAME W/ THE UPPER LEVEL SYSTEM WILL GET
STREWN OUT FROM WEST TO EAST AND JUST TO OUR SOUTH THIS WEEKEND.
THERE WILL BE ENOUGH BANKING OF N-NELY FLOW INTO THE LEE OF THE BLUE
RIDGE TO CREATE SCATTERED SHOWERS ACROSS THE REGION. THE COVERAGE
WILL BE MORE WIDESPREAD ON SAT THAN SUN. PRECIP CHANCES WILL BE
LIMITED TO THE BLUE RIDGE AND CNTRL APLCNS ON SUN...AS NELY FLOW
FURTHER STABILIZES THE ERN SECTIONS OF THE CWA. THE MAIN STORY
THOUGH WILL BE MUCH COOLER TEMPS THIS WEEKEND...ABOUT 10 DEGREES
BELOW NORMAL ON SAT AND ONLY SLIGHTLY WARMER ON SUN.
THE UPPER WAVE WILL REMAIN STALLED TO OUR SOUTH HEADING INTO EARLY
NEXT WEEK...JUST IN TIME FOR YET ANOTHER UPPER LEVEL SYSTEM TO
ARRIVE FROM THE GREAT LAKES REGION. THIS NEXT FEATURE WILL SLIDE
THRU W/ A LITTLE MORE FORCE THAN THE PREVIOUS FEW AND PUSH THE
STALLED BOUNDARY AND THE BERMUDA HIGH FURTHER TO THE SOUTH AND AWAY
FROM THE ATLC COAST. NWLY FLOW WILL KEEP THE AREA QUIET AND BACK
TOWARD AVERAGE IN TERMS OF DAILY HIGHS/LOWS THRU THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
WEAK SFC TROUGH NOW S OF DC METROS AS INDICATED BY NNWLY FLOW. AREA
REMAINS IN A MOIST ENVIRONMENT...WITH SHOWERS/THUNDERSTORMS
EXPECTED TO DEVELOP FOR THE LATE AFTERNOON AND EVENING. SOME
ACTIVITY MAY CONTINUE INTO THE OVERNIGHT HOURS WITH THE FRONTAL
BOUNDARY SLOWLY PRESSING SOUTH OF THE MASON DIXON LINE. WIND
DIRECTION WILL BE LINKED TO THE POSITION OF THE FRONT...WITH A
SHIFT TO THE EAST TO THE NORTH OF THE FRONT /INITIALLY
MRB...BWI...MTN/ OVERNIGHT AND A SOUTHWEST WIND TO THE SOUTH OF
THE FRONT. AREAS NORTH OF THE FRONT WITH THE EASTERLY WIND MAY
EVENTUALLY HAVE FLIGHT RESTRICTIONS IN LOWER CEILINGS FRIDAY.
ANOTHER LOW PRESSURE SYSTEM WILL SLIDE DOWN ACROSS THE AREA FROM THE
NORTH ON FRI. SOME TSTM ACTIVITY EXPECTED FROM LATE MRNG INTO THE
EARLY AFTN HRS...BUT WILL DISSIPATE ACROSS MUCH OF THE REGION AND
MOVE FURTHER SOUTH TOWARD THE LATE AFTN/EVE HRS. BEHIND THE
ACCOMPANYING LOW...NELY WINDS WILL PUSH IN ACROSS THE I-95 CORRIDOR
AND PERIODS OF RAIN WILL CONTINUE INTO THE NIGHTTIME HRS FRI. SOME
LINGERING SHOWERS WILL AFFECT THE REGION ON SAT BUT LARGELY
DISSIPATE BY SUN. HIGH PRESSURE WILL MOVE INTO THE AREA FOR THE
FIRST PART OF NEXT WEEK...THOUGH PLENTY OF ACTIVITY WON`T BE TOO FAR
AWAY - W/ A STALLED FRONT JUST TO OUR SOUTH AND ANOTHER LOW PRESSURE
SYSTEM COMING IN FROM THE NW.
&&
.MARINE...
LIGHT NLY FLOW FROM A WEAK BOUNDARY THAT HAS CROSSED THE MD PORTION
OF THE BAY. MAIN CONCERN WILL BE THE POTENTIAL FOR STRONG THUNDERSTORMS
THIS EVENING AND OVERNIGHT WHICH MAY PRODUCE STRONG GUSTY WINDS.
A WEAK SFC LOW WILL MOVE DOWN ACROSS THE AREA DURING THE DAY FRIDAY.
BEHIND THE LOW...NELY FLOW WILL BEGIN AND CREATE SOME PERIODIC
10-15KT GUSTS ACROSS THE NRN-MIDDLE DAY. THIS WILL CONTINUE
OVERNIGHT AND INTO SAT. THE LOW WILL MOVE OFF THE COAST BY SUNDAY
AND LIGHT S-SWLY FLOW WILL ARRIVE AS HIGH PRESSURE SETTLES OVER THE
AREA.
&&
.CLIMATE...
DCA...
THE HIGH TEMPERATURE ON WEDNESDAY REACHED 101F. THE DAILY RECORD WAS
103 SET IN 1887. A RECORD HIGH MINIMUM OF 80 DEGREES WAS
SET...BREAKING THE OLD RECORD OF 79 SET IN 2002.
INCLUDING WEDNESDAY...THE HIGH TEMP HAS REACHED OR EXCEEDED 95F ON
18 DAYS AND 100F ON 7 DAYS SO FAR THIS YEAR...WHICH ARE BOTH THE
MOST ON RECORD THROUGH 18 JUL AT DCA. PRIOR TO THIS YEAR...THE MOST
95-DEGREE AND 100-DEGREE DAYS THROUGH 18 JUL WAS 16 IN 1991 AND 5 IN
1988...RESPECTIVELY. THE MOST 95-DEGREE AND 100-DEGREE DAYS ON
RECORD THAT OCCURRED IN A CALENDAR YEAR WAS 28 IN 1980 AND 11 IN
1930...RESPECTIVELY.
BWI...
THE HIGH TEMPERATURE WEDNESDAY REACHED 104F. THIS BROKE A 125 YR OLD
DAILY RECORD - 102 SET IN 1887.
INCLUDING WEDNESDAY...THE HIGH TEMP HAS REACHED OR EXCEEDED 95F ON
17 DAYS AND 100F ON 6 DAYS SO FAR THIS YEAR...WHICH ARE BOTH THE
MOST ON RECORD THROUGH 18 JUL AT BWI. PRIOR TO THIS YEAR...THE MOST
95-DEGREE AND 100-DEGREE DAYS THROUGH 18 JUL WAS 14 IN 1988 AND 5 IN
1988 AND 2010...RESPECTIVELY. THE MOST 95-DEGREE AND 100-DEGREE DAYS
ON RECORD THAT OCCURRED IN A CALENDAR YEAR WAS 23 IN 1991 AND 7 IN
BOTH 1988 AND 2010...RESPECTIVELY.
IAD...
THE HIGH TEMPERATURE WEDNESDAY REACHED 101F...WHICH IS A NEW DAILY
TEMPERATURE RECORD. THE OLD RECORD WAS 100F SET IN 1969 AND 1986.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BPP
NEAR TERM...BAJ
SHORT TERM...BAJ
LONG TERM...GMS
AVIATION...BAJ/BPP/GMS
MARINE...BAJ/BPP/GMS
CLIMATE...LWX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
400 PM EDT THU JUL 19 2012
.SYNOPSIS...
AN UPPER SHORT WAVE...COMBINED WITH ABUNDANT MOISTURE AND DIURNAL
HEATING PROVIDE UNSTABLE CONDITIONS THROUGH FRIDAY. A COLD FRONT WILL
MOVE THROUGH THE AREA FRIDAY NIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AN APPROACHING UPPER LEVEL TROUGH WILL PROVIDE ENOUGH FORCING OVER
A HIGH CAPE...HIGH PRECIPITABLE WATER ENVIRONMENT THROUGH FRIDAY.
SEVERAL BANDS OF THUNDERSTORMS ARE EXPECTED TO DEVELOP AND MOVE
FROM THE WEST THIS EVENING AND LATER TONIGHT. HPC QPF GUIDANCE
SUGGEST NEAR 3 INCHES MAINLY NORTHERN WV PANHANDLE...SOUTH ALONG
THE OH RIVER INTO PKB THROUGH 12Z FRIDAY.
EXPECT HEAVY DOWNPOURS WITH EVERY SINGLE STORM. MODELS SHOW PRECIPITABLE
WATER EXCEEDING 2 INCHES THROUGH THIS AFTERNOON THROUGH FRIDAY.
THE NAM AND HPC SUGGEST A STRONGER SHOT OF PRECIPITATION OVERNIGHT
TONIGHT. A MODERATE RISK FOR EXCESSIVE RAINFALL STILL IN EFFECT FROM
HPC THROUGH 00Z SATURDAY. DUE TO YESTERDAYS RAINFALL AMOUNTS
MEASURED BY RAINGAGE...BETWEEN 0.5 TO 1.8 INCHES ACROSS NORTH
CENTRAL WV...WHILE RADAR STORM TOTALS...ALTHOUGH
OVERESTIMATED...SHOWED HIGHER AMOUNTS AWAY FROM GROUND
GAGES...GROUNDS ARE NEARLY SATURATED. BESIDES THESE AREAS ARE MORE
PRONE TO FLOODING. THEREFORE...KEPT FLASH FLOOD WATCH FOR SEVERAL
COUNTIES ACROSS THE CENTRAL AND NORTH CENTRAL WV...INCLUDING
ATHENS COUNTY IN SOUTHEAST OH.
ADJUSTED POPS CLOSER TO THE HRRR PER BETTER AGREEMENT ON LACK OF
AFTERNOON CONVECTION...WHILE OTHER MESO AND SYNOPTIC MODELS
OVERDUE PCPN. A DISORGANIZED MCS TYPE FEATURE CONTINUES TO PRODUCE
BANDS OF THUNDERSTORMS ACROSS OH. THE FIRST BAND HAVE REACHED
SOUTHEAST OH BY MID AFTERNOON...AND IS EXPECTED TO MOVE EAST TO
AFFECT THE FLASH FLOOD WATCH AREA EARLY THIS EVENING. ADDITIONAL
BAND OF STORMS ARE EXPECTED TO DEVELOP OVERNIGHT POSING THE THREAT
FOR SIGNIFICANT RAIN ACCUMULATIONS.
MOIST...WARM...AND HIGH SFC CAPE ENVIRONMENT REMAIN IN PLACE ON
FRIDAY...WHILE A SECONDARY VORT MAX MOVES ACROSS ASSOCIATED WITH
THE AFOREMENTIONED UPPER TROUGH. THEREFORE...KEPT HIGH LIKELY POPS
THROUGH THE END OF THE PERIOD FOCUSING THE EASTERN HALF OF THE
AREA.
WENT CLOSER TO THE LAV/MAV NUMBERS THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
BY FRIDAY EVENING THE COLD FRONT IS EXPECTED TO BE NEAR THE OHIO
RIVER. MEANWHILE BEST LARGE SCALE FORCING FOR ASCENT IS LOCATED OVER
THE NORTHEAST PART OF FORECAST AREA. IN ADDITION...A VORT MAX WILL
BE PUSHING SE-WARD ACROSS NORTHERN WV...WITH LIFT ASSOC WITH IT OUT
AHEAD ACROSS NE PART OF CWA. FINALLY...WITH COLD FRONT MOVING INTO
NORTHERN PART OF AREA AND GOOD LLVL MOISTURE CONVERGENCE
NOTED...SHOWERS/STORMS A GOOD BET TO CONTINUE ACROSS MUCH OF THE
AREA WITH THE HIGHEST POPS WEIGHTED ACROSS NE ZONES BY THE EVENING
HOURS. THOUGH GREATEST COVERAGE IS EXPECTED NORTHEAST...BETTER
CHANCE AT STRONG TO SVR WX APPEARS TO BE ACROSS SOUTHERN AND WESTERN
PARTS OF FORECAST AREA WHERE MARGINAL SHEAR COINCIDES BEST WITH
HIGHEST AXIS OF INSTABILITY. HEAVY DOWNPOURS AND STRONG WINDS
CONTINUE TO BE THE PRIMARY HAZARDS MAINLY BTWN 00Z-03Z. DCAPE VALUES
OF BTWN 500J-800J WITH SFC-MIDLEVEL THETA-E DIFFERENCES OF ~25C
PARTICULARLY ACROSS THE WEST ZONES INDICATE BETTER POTENTIAL FOR
STRONG DOWNBURST WINDS IN THESE LOCALES. SHOWERS/STORMS WILL PUSH
EASTWARD AND SOUTHWARD OVERNIGHT WITH DIMINISHING INTENSITY WITH
LOSS OF INSTABILITY.
BY SATURDAY MORNING COLD FRONT SHOULD BE LOCATED ACROSS THE
SOUTHEAST PART OF CWA WITH LARGE SCALE FORCING FOR SUBSIDENCE
OVERSPREADING THE AREA FROM NW/SE. BEST DEEP LAYER MOISTURE WILL BE
LOCATED NEAR AND AHEAD OF THE FRONT AND THUS WILL CONTINUE SLIGHT
CHANCE/LOW CHANCE POPS IN THIS AREA. FRONTAL ZONE WILL STALL TO THE
SOUTH AND SOUTHEAST ALONG WITH MOISTURE WITH CONTINUED CHANCE OF
SHOWERS AND THUNDERSTORMS PRIMARILY FAR EAST AND SOUTH THE REMAINDER
OF SATURDAY. WILL CONTINUE PRIMARILY SLIGHT CHANCE POPS SUNDAY AGAIN
PRIMARILY FOR FAR EASTERN AND SOUTHERN ZONES AS INSTABILITY AND LLVL
MOISTURE REMAIN ENTRENCHED IN THOSE AREAS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
OPERATIONAL EXTENDED NWP CONTINUES TO BE IN REASONABLY GOOD
AGREEMENT REGARDING GENERAL FEATURES DURING THIS PERIOD...DEPICTING
A STRENGTHENING UPPER LEVEL RIDGE OVER THE CENTRAL CONUS/HIGH PLAINS
REGION WITH ANOTHER OFF SE ATLANTIC COAST...WITH WNW/NW FLOW ALOFT
OVER FORECAST AREA THROUGH MUCH OF THE PERIOD. AS UPPER HIGH
ATTEMPTS TO BUILD EASTWARD...MAX TEMPS WILL REMAIN SLIGHTLY ABOVE
NORMAL LEVEL WITH READING CONTINUING IN THE UPPER 80S/LOWER 90S
LOWLAND AREAS. EXTENDED NWP AND ENSEMBLES ALSO IN DECENT AGREEMENT
WITH MOVING A FRONT INTO THE AREA TUESDAY AND WILL GO AHEAD AND
RAISE POPS INTO THE LOW CHANCE CATEGORY FOR THIS PERIOD. DIFFERENCES
ARISE HOWEVER WITH THE HANDLING OF THIS FRONT HOWEVER AND WILL USE A
BLEND WITH A LEANING TOWARDS THE EC WITH REGARD TO DAYS 6-7. TEMPS
WILL GENERALLY CONTINUE IN THE UPPER 80S/LOWER 90S FOR THE
PERIOD...PERHAPS A FEW DEGREES COOLER TUESDAY WITH THE FRONT/MORE
CLOUDS IN AREA.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THE BEGINNING OF THE
PERIOD...OUTSIDE STORMS. THE HRRR MODEL SEEMS MORE CONVINCING
BRINGING CONVECTION INTO SOUTHEAST OH TO AFFECT HTS AROUND
19-22Z... PKB AND CRW AROUND 20-23Z. STORMS COULD DECAY AS THEY
MOVE OVER THE EASTERN SITES THIS EVENING TO PROVIDE VCTS AND RAIN
SHOWERS.
CAN NOT RULE OUT POST PCPN FOG AT HTS DEPENDING ON CLEARING.
THEREFORE...LEFT 4SM WITH MVFR CEILINGS.
LOOSING DIURNAL HEATING BUT GAINING UPPER LEVEL FORCING MAKE UP
FOR A TRICKY FORECAST OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF THUNDERSTORMS AND ANY
CATEGORY CHANGES MAY VARY. MORNING FOG COVERAGE MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY M L M M M M M M M M H H
HTS CONSISTENCY M M M H H H H H H H H H
BKW CONSISTENCY H M M M M H H H H H H H
EKN CONSISTENCY H M M M M M M M H H H H
PKB CONSISTENCY L L M M H H M M M M L H
CKB CONSISTENCY M L L M M M M M L L L L
AFTER 18Z FRIDAY...
IFR POSSIBLE FRIDAY AFTERNOON IN SCATTERED AFTERNOON CONVECTION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR WVZ009-016>020-
028>031-039-040.
OH...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR OHZ075.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...50
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
224 PM EDT THU JUL 19 2012
.SYNOPSIS...
AN UPPER SHORT WAVE...COMBINED WITH ABUNDANT MOISTURE AND DIURNAL
HEATING PROVIDE UNSTABLE CONDITIONS THROUGH FRIDAY. A COLD FRONT WILL
MOVE THROUGH THE AREA FRIDAY NIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AN APPROACHING UPPER LEVEL TROUGH WILL PROVIDE ENOUGH FORCING OVER
A HIGH CAPE...HIGH PRECIPITABLE WATER ENVIRONMENT THROUGH FRIDAY.
SEVERAL BANDS OF THUNDERSTORMS ARE EXPECTED TO DEVELOP AND MOVE
FROM THE WEST THIS EVENING AND LATER TONIGHT. HPC QPF GUIDANCE
SUGGEST NEAR 3 INCHES MAINLY NORTHERN WV PANHANDLE...SOUTH ALONG
THE OH RIVER INTO PKB THROUGH 12Z FRIDAY.
EXPECT HEAVY DOWNPOURS WITH EVERY SINGLE STORM. MODELS SHOW PRECIPITABLE
WATER EXCEEDING 2 INCHES THROUGH THIS AFTERNOON THROUGH FRIDAY.
THE NAM AND HPC SUGGEST A STRONGER SHOT OF PRECIPITATION OVERNIGHT
TONIGHT. A MODERATE RISK FOR EXCESSIVE RAINFALL STILL IN EFFECT FROM
HPC THROUGH 00Z SATURDAY. DUE TO YESTERDAYS RAINFALL AMOUNTS
MEASURED BY RAINGAGE...BETWEEN 0.5 TO 1.8 INCHES ACROSS NORTH
CENTRAL WV...WHILE RADAR STORM TOTALS...ALTHOUGH
OVERESTIMATED...SHOWED HIGHER AMOUNTS AWAY FROM GROUND
GAGES...GROUNDS ARE NEARLY SATURATED. BESIDES THESE AREAS ARE MORE
PRONE TO FLOODING. THEREFORE...KEPT FLASH FLOOD WATCH FOR SEVERAL
COUNTIES ACROSS THE CENTRAL AND NORTH CENTRAL WV...INCLUDING
ATHENS COUNTY IN SOUTHEAST OH.
ADJUSTED POPS CLOSER TO THE HRRR PER BETTER AGREEMENT ON LACK OF
AFTERNOON CONVECTION...WHILE OTHER MESO AND SYNOPTIC MODELS
OVERDUE PCPN. A DISORGANIZED MCS TYPE FEATURE CONTINUES TO PRODUCE
BANDS OF THUNDERSTORMS ACROSS OH. THE FIRST BAND HAVE REACHED
SOUTHEAST OH BY MID AFTERNOON...AND IS EXPECTED TO MOVE EAST TO
AFFECT THE FLASH FLOOD WATCH AREA EARLY THIS EVENING. ADDITIONAL
BAND OF STORMS ARE EXPECTED TO DEVELOP OVERNIGHT POSING THE THREAT
FOR SIGNIFICANT RAIN ACCUMULATIONS.
MOIST...WARM...AND HIGH SFC CAPE ENVIRONMENT REMAIN IN PLACE ON
FRIDAY...WHILE A SECONDARY VORT MAX MOVES ACROSS ASSOCIATED WITH
THE AFOREMENTIONED UPPER TROUGH. THEREFORE...KEPT HIGH LIKELY POPS
THROUGH THE END OF THE PERIOD FOCUSING THE EASTERN HALF OF THE
AREA.
WENT CLOSER TO THE LAV/MAV NUMBERS THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
MAIN WEATHER MAKER FOR THE SHORT TERM WILL BE SLOW MOVING COLD
FRONT/UPPER LEVEL SHORTWAVE TROUGH DRIFTING SOUTH ACROSS THE CWA
FRIDAY INTO SATURDAY. VERY ABUNDANT MOISTURE IN PLACE...NAM SHOWING
OVER 2 INCH PWATS ACROSS MUCH OF THE FORECAST AREA
FRIDAY...DECREASING TO 1.5-2 INCHES FRIDAY NIGHT...AND 1.25-1.5
INCHES SATURDAY. GENERALLY WENT THIS WAY WITH THE POPS AS
WELL...WITH THE HIGHEST POPS ON FRIDAY AFTERNOON...SLOWLY EXITING TO
THE SOUTHEAST THROUGH SATURDAY NIGHT. WITH PWATS THIS
HIGH...DOWNPOURS WITH LOCALIZED FLASH FLOODING COULD POSE A
PROBLEM...ESPECIALLY IF SEVERAL STRONG CELLS TRAIN OVER THE SAME
AREA THROUGH THE DAY FRIDAY.
WITH LOTS OF MOISTURE...INSTABILITY ALSO FAIRLY HIGH. NAM SHOWING
1500-3000 J/KG CAPE FRIDAY AFTERNOON...AND EVEN THE GFS RAMPING UP
TO AROUND 2500 J/KG ACROSS CENTRAL CWA FRIDAY. SHEAR NOT OVERLY
IMPRESSIVE...WITH 15-20 KTS BULK SHEAR AT PEAK INSTABILITY...BUT
STILL COULD SEE SOME STRONG TO MARGINALLY SEVERE WIND GUSTS OUT OF
THE BEST CELLS.
TEMPS A BIT DIFFICULT...MAV QUITE A BIT WARMER THAN MET ON
FRIDAY...WITH A FLIP FLOP ON SATURDAY WITH MET WARMER. IN
GENERAL...VERIFICATION INDICATES GUIDANCE HAS STRUGGLED THE LAST
COUPLE DAYS SO STAYED MIDDLE OF THE ROAD WITH NO SIGNIFICANT
CHANGES. DID COOL LOWS SATURDAY NIGHT A BIT...THINKING DRIER AIR
AND LESS CLOUDS SHOULD ALLOW FOR MORE RADIATIONAL COOLING.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
OPERATIONAL EXTENDED NWP IN GOOD AGREEMENT REGARDING GENERAL
FEATURES DURING THIS PERIOD...WITH USUAL DIFFS IN STRENGTH AND
PLACEMENT. A RETURN TO A NORTHWEST FLOW PATTERN IS IN STORE FOR THE
AREA FOR THE SUN-WED TIME FRAME AS AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BUILDS OVER THE CENTRAL HIGH PLAINS WITH ANOTHER RIDGE OFF
THE SE ATLANTIC SEABOARD AND WEAK TROUGHING OVER NORTHEAST
CONUS...RESULTING IN VARIOUS AMPLITUDES OF WNW-NW FLOW ALOFT FOR THE
PERIOD. A SLOW WARMING TREND CAN BE EXPECTED THROUGH THE WEEKEND AND
MONDAY BUT TEMPS LOOK TO REMAIN JUST SLIGHTLY ABOVE NORMAL WITH
READINGS INTO THE UPPER 80S/LOWER 90S. SUNDAY SHOULD REMAIN DRY FOR
ALL AREAS EXCEPT THE EASTERN HIGH TERRAIN AS MOISTURE REMAINS
GENERALLY SOUTH AND EAST OF AREA. BY MONDAY AND TUESDAY MOISTURE
BEGINS TO SURGE BACK NORTHWARD AROUND PERIPHERY OF HIGH TO THE EAST
AND APPROACHING COLD FRONT SLATED FOR TUESDAY...WHICH WILL HALT THE
WARMING TREND AND BRING SLIGHTLY COOLER TEMPS IN THE MID/UPPER 80S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THE BEGINNING OF THE
PERIOD...OUTSIDE STORMS. THE HRRR MODEL SEEMS MORE CONVINCING
BRINGING CONVECTION INTO SOUTHEAST OH TO AFFECT HTS AROUND
19-22Z... PKB AND CRW AROUND 20-23Z. STORMS COULD DECAY AS THEY
MOVE OVER THE EASTERN SITES THIS EVENING TO PROVIDE VCTS AND RAIN
SHOWERS.
CAN NOT RULE OUT POST PCPN FOG AT HTS DEPENDING ON CLEARING.
THEREFORE...LEFT 4SM WITH MVFR CEILINGS.
LOOSING DIURNAL HEATING BUT GAINING UPPER LEVEL FORCING MAKE UP
FOR A TRICKY FORECAST OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF THUNDERSTORMS AND ANY
CATEGORY CHANGES MAY VARY. MORNING FOG COVERAGE MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H M L M M M M M M M M
HTS CONSISTENCY M M M M M H H H H H H H
BKW CONSISTENCY H H H M M M M H H H H H
EKN CONSISTENCY H H H M M M M M M M H H
PKB CONSISTENCY H M L L M M H H M M M M
CKB CONSISTENCY M H M L L M M M M M L L
AFTER 18Z FRIDAY...
IFR POSSIBLE FRIDAY AFTERNOON IN SCATTERED AFTERNOON CONVECTION.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR WVZ009-016>020-
028>031-039-040.
OH...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR OHZ075.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...50
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
347 PM CDT THU JUL 19 2012
.DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT.
INTENSE HEAT HAS RETURNED TODAY WITH SEVERAL LOCATIONS OVER NERN
AR AND THE BOOTHEEL EXCEEDING 100 DEGREES. IN FACT...AT 3 PM
JONESBORO HAS REACHED AN IMPRESSIVE 105 DEGREES WITH MID 100S
EXTENDING TO THE SOUTHWEST FROM THERE. COOLER AIR TEMPERATURES
CAN BE FOUND TO THE SOUTHEAST OVER NERN MS...BUT DEW POINTS ARE
EXTREMELY OPPRESSIVE AND ARE APPROACHING 80 DEGREES IN SOME SPOTS
DOWN THERE...THUS THE DIFFERENCE IN HEAT INDEX AROUND THE AREA IS
ONLY A FEW DEGREES. OBVIOUSLY DECIDED TO EXPAND THE HEAT ADVISORY
ACROSS THE REST OF THE CWA FOR THIS AFTERNOON AND TONIGHT.
CONVECTION THIS AFTERNOON HAS BEEN RATHER UNIMPRESSIVE DUE TO THE
STABLE AIRMASS LEFT BEHIND FROM OUTFLOWS LAST NIGHT. HOWEVER...
ACTIVITY IS BEGINNING TO INCREASE IN COVERAGE AND INTENSITY OVER
ERN AR...NRN MS...AND SERN MO AS THE CAP FINALLY ERODES. THINK
THIS TREND WILL CONTINUE INTO THE EVENING WITH THE POTENTIAL FOR
ADDITIONAL ACTIVITY TO FORM ALONG THE FRONT THIS EVENING AS IT
SAGS SOUTH FROM SRN MO. MAINTAINED NEAR 50 POP FOR TONIGHT ACROSS
THE ENTIRE AREA...WHICH MAY NEED TO BE ADJUSTED WHEN IT BECOMES
CLEAR HOW EXISTING OUTFLOW BOUNDARIES CONTRIBUTE TO THE COVERAGE.
A FEW SEVERE STORMS WILL BE POSSIBLE WITH DAMAGING WINDS.
THE FRONT WILL SAG SOUTH INTO NRN MS FRIDAY...REDUCING POPS FROM
NORTH TO SOUTH. THERE ARE TWO CONCERNS FOR FRIDAY. ONE BEING HIGHS
AND DEW POINTS...AND THE OTHER BEING SEVERE WX POTENTIAL ALONG AND
AHEAD OF THE FRONT.
HIGH TEMPERATURES WILL BE HOT...QUESTION IS HOW HOT. THIS IS A
FAVORABLE PATTERN FOR 100 DEGREE DAYS OVER THE DELTA AS DRIER AIR
FEEDS IN ON NORTH WINDS AS THE THERMAL RIDGE LAGS ALONG AND BEHIND
THE SURFACE FRONT. COULD SEE SOME AREAS EXCEED 103 DEGREES AGAIN
TOMORROW...PARTICULARLY ALONG I-40 AND WEST OF I-55 WHERE THE 925
MB THERMAL RIDGE IS EXPECTED TO BE LAID OUT AROUND 21Z. THINK THE
MAV TEMPERATURES ARE EMBARRASSINGLY LOW SO DISREGARDED THEM
COMPLETELY. WENT SLIGHTLY HIGHER THAN A BLEND OF MET AND EURO.
DEW POINTS AGAIN WILL BE HIGH ALONG AND AHEAD OF THE FRONT WITH
SIGNIFICANT POOLING POSSIBLE. DESPITE HIGHS ONLY IN THE LOW TO MID
90S OVER LOCATIONS NEAR THE TN RIVER AND NERN MS...DEW POINTS WILL
AGAIN BE IN THE MID/UPPER 70S YIELDING HEAT INDICES AOA 105
DEGREES. FURTHER NORTHWEST...IT IS HARD TO SAY HOW MUCH DEW POINTS
WILL MIX BUT THINK THEY SHOULD REMAIN AT LEAST IN THE UPPER 60S.
THUS...ISSUED A HEAT ADVISORY FOR THE ENTIRE MIDSOUTH THROUGH 7 PM
FRIDAY. COULD SEE SOME LOCATIONS JUST BEHIND THE FRONT NEAR I-40
REMAINING HIGH ON DEW POINTS /MID 70S/...JUXTAPOSED WITH
TEMPERATURES EXCEEDING 100 /INCLUDING MEMPHIS/. IN THAT CASE...AN
UPGRADE TO AN EXCESSIVE HEAT WARNING WILL BE NEEDED.
THINK THE SEVERE THREAT FRIDAY WILL BE CONFINED INTO THE
SOUTHEASTERN-MOST COUNTIES. HERE...SBCAPE VALUES OF 4000 TO 5000
J/KG WILL BE OBTAINED FROM POOLING DEW POINTS AND DRYING MID
LEVELS.STRENGTHENING MID LEVEL FLOW ASSOCIATED WITH THE APPROACH
OF THE FRONT SHOULD PROVIDE ENOUGH SHEAR FOR AT LEAST SOME
ORGANIZATION OF STORM CLUSTERS OR LINE SEGMENTS CAPABLE OF WIND
DAMAGE...ALTHOUGH WITH THE DRYING MID LEVELS HAIL WILL ALSO BE
POSSIBLE.
DRIER AIR WILL ARRIVE SATURDAY...BUT TEMPERATURES WILL STILL
REMAIN ABOVE AVERAGE AS THE MID LEVEL RIDGE REMAINS IN PLACE OVER
THE MID MISSISSIPPI VALLEY. THE DRIER AIR SHOULD MITIGATE THE NEED
FOR ANOTHER HEAT ADVISORY.
.LONG TERM...SUNDAY THROUGH THURSDAY.
WEAK CONVERGENCE AND A LESSER INFLUENCE OF THE SEMI-PERMANENT 2012
RIDGE OVER NERN MS WILL ALLOW FOR SMALL CHANCES FOR STORMS EACH
DAY THROUGH TUESDAY. FURTHER NORTHWEST...NO LIFTING MECHANISMS AND
THE RIDGE SHOULD KEEP THE RISK AT BAY.
EURO SHOWS THE RIDGE EXPANDING FOR MID/LATE WEEK...WITH TEMPERATURES
INCREASING BACK TOWARD OR EXCEEDING 100. DEW POINTS MAY CREEP BACK
INTO THE LOWER 70S AND HEAT HEADLINES MAY BE NEEDED AGAIN AT SOME
POINT LATER NEXT WEEK.
BORGHOFF
&&
.AVIATION...
18Z TAFS
OUTFLOW BOUNDARY THAT MOVED THROUGH THE MIDSOUTH LAST EVENING FROM
THE EAST HAS RESULTED IN AN INITIALLY MORE STABLE LOWER ATMOSPHERE
TO START THE 18Z TAF PERIOD. THE REMNANTS OF THIS BOUNDARY EXTENDED
FROM NEAR TUP...WESTWARD TO 50SM SOUTH OF MEM... TO 70SM SW OF JBR.
BEST TSRA CHANCE WILL BE OVER NORTH MS... SOUTH OF MEM THIS
AFTERNOON. ISOLATED TSRA WILL BE POSSIBLE BEHIND THIS BOUNDARY...
INCLUDING NEAR MEM AFTER 20Z...ONCE CONVECTIVE TEMPS ARE REACHED.
12Z NAM AND 13Z HRRR MODELS SUGGEST A SECONDARY BANDED AREA OF
SHRA/TSRA MOVING SOUTH THROUGH MEM IN THE 01Z TO 03Z TIME FRAME.
THIS ACTIVITY WOULD BE A SOUTHERN PROGRESSION OF PREFRONTAL
SHRA/TSRA THAT WAS OBSERVED ACROSS SOUTH CENTRAL MO AT MIDDAY.
THERE IS SOME DOUBT WHETHER FORCING WILL BE SUFFICIENT TO
OVERCOME A STRENGTHENING CONVECTIVE CAP FOLLOWING SUNSET. GIVEN
MODEL CONSENSUS...HAVE INCLUDED A SHORT TEMPO FOR EARLY EVENING
PERIOD AT MEM.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 79 100 78 97 / 40 20 10 10
MKL 76 96 72 94 / 50 20 10 0
JBR 79 101 75 99 / 30 10 0 0
TUP 76 93 77 92 / 50 50 30 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR CLAY-
CRAIGHEAD-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-RANDOLPH.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT FRIDAY FOR CLAY-
CRAIGHEAD-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-RANDOLPH.
HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR CRITTENDEN-CROSS-LEE AR-
PHILLIPS-ST. FRANCIS.
MO...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-
PEMISCOT.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT FRIDAY FOR
DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR ALCORN-BENTON MS-CALHOUN-
CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-
TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR CARROLL-CHESTER-CROCKETT-
DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-HAYWOOD-
HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-OBION-
SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1255 PM CDT THU JUL 19 2012
.UPDATE...
UPDATED FOR AVIATION.
&&
.PREV DISCUSSION... /ISSUED 1045 AM CDT THU JUL 19 2012/
UPDATE...
GOING FORECAST LOOKS GOOD THIS MORNING. TEMPERATURES AND DEW
POINTS HAVE REBOUNDED QUICKLY WITH MANY AREAS NORTH OF I-40
APPROACHING OR EXCEEDING 90 AT 10 AM. THERMAL RIDGE BUILDING IN
ACROSS NERN AR AND NWRN TN SHOULD ALLOW TEMPERATURES TO RISE INTO
THE 100S THIS AFTERNOON WITH LITTLE DEW POINT MIXING EXPECTED
GIVEN SUCH A MOISTURE-LADEN AIRMASS. THUS...NO CHANGES TO THE
HEADLINES ARE ANTICIPATED ATTM...BUT WILL LIKELY BE EXTENDING
THEM INTO FRIDAY WITH THE AFTERNOON PACKAGE ISSUANCE.
SPC MESOANALYSIS INDICATES MUCH LOWER CAPE THIS MORNING AND A MUCH
STRONGER CAP THANKS TO OVERNIGHT CONVECTION CONTAMINATION. ANOTHER
OUTFLOW IS APPROACHING THE MEMPHIS METRO AS OF THIS WRITING FROM
CONVECTION ACROSS CENTRAL MO. A FEW STORMS HAVE BEEN FIRING OVER
TALLAHATCHIE COUNTY...WHICH IS IN AN AREA OF WEAKER CAPPING. THINK
STORMS WILL RE-FIRE THIS AFTERNOON AND EXPAND EASTWARD...BUT IT
MAY TAKE SEVERAL MORE HOURS TO DESTABILIZE THINGS SUFFICIENTLY.
BORGHOFF
PREV DISCUSSION... /ISSUED 308 AM CDT THU JUL 19 2012/
A FEW LEFTOVER SHOWERS FROM THIS EVENINGS CONVECTION REMAIN
ACROSS NORTH MISSISSIPPI. THE SHOWERS CONTINUE TO PUSH SOUTH AS
THEY DISSIPATE THUS ONLY EXPECT THEM TO REMAIN IN THE CWA FOR
ANOTHER HOUR OR TWO.
NONE OF THE MODELS INITIALIZED WELL THUS CONFIDENCE IN THIS FORECAST
IS PRETTY LOW. A FRONTAL BOUNDARY CURRENTLY STRETCHES FROM CENTRAL
KANSAS TO THE GREAT LAKES. A LINE OF SHOWERS AND THUNDERSTORMS ARE
OCCURRING JUST AHEAD OF THE FRONT. ALL OF THE MODELS SEEM TO
POINT AT THIS BOUNDARY AS BEING THE PRIMARY FOCUS OF RAIN CHANCES
THROUGH FRIDAY EVENING. IN FACT THE 12Z NAM BRINGS THE LINE OF
CONVECTION INTO NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL AND
NORTHWEST TENNESSEE BY LATE THIS AFTERNOON INTO EARLY THIS
EVENING. UNTIL THEN TRYING TO PINPOINT WHEN AND WHERE CONVECTION
WILL FIRE IS PRETTY HARD. THERE ARE SEVERAL LEFTOVER OUTFLOW
BOUNDARIES FROM THIS EVENINGS CONVECTION LEFT ACROSS THE CWA. ANY
ONE OF THESE COULD SET OFF SOME SHOWERS AND THUNDERSTORMS. IN
ADDITION...MODELS PINPOINT AT MUCH OF NORTH MISSISSIPPI FOR
DEVELOPMENT...DUE TO THE POSITION OF THE UPPER RIDGE. THUS WILL
GO WITH 20 POPS THIS MORNING ACROSS THE ENTIRE CWA. FOR THIS
AFTERNOON...WILL CONTINUE WITH LIKELYS ACROSS NORTHEAST
MISSISSIPPI WHILE LEAVING THE REST OF THE CWA WITH CHANCE POPS.
ALTHOUGH WILL BUMP UP NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL
FROM 30 POPS TO 40 POPS. A FEW STORMS COULD BE STRONG TO SEVERE.
ANOTHER TROUBLE SPOT IN THE FORECAST IS TEMPERATURES...YESTERDAYS
TEMPERATURES WERE WAY ABOVE GUIDANCE. THIS ALLOWED HEAT INDICES TO
ACTUALLY REACH 110 DEGREES...HEAT WARNING CRITERIA IN A FEW
LOCATIONS. WOULD THINK THIS WOULD OCCUR AGAIN TODAY BUT ONE OF THE
LEFTOVER OUTFLOW BOUNDARIES WENT THROUGH MEMPHIS AND JACKSON THIS
EVENING. TEMPERATURES ARE NOW RUNNING THREE TO SIX DEGREES COOLER
AT 1 AM CDT THAN THEY WERE 24 HOURS AGO. IN ADDITION...DEWPOINTS HAVE
ALSO DROPPED. ABUNDANT HIGH CLOUDS WILL ALSO INHIBIT TEMPERATURES
FROM RECOVERING QUICKLY THIS MORNING. THUS WILL GO WITH GUIDANCE
AND GO 98 DEGREES FOR A HIGH IN MEM THIS AFTERNOON. FOR MKL WILL
GO ONE DEGREE ABOVE AND GO WITH A HIGH OF 95 DEGREES. NOW
NORTHEAST ARKANSAS IS A DIFFERENT STORY...OUTFLOW BOUNDARIES HAVE
NOT AFFECTED JONESBORO OR WALNUT RIDGE THUS TEMPERATURES ARE
EXACTLY WHERE THEY WERE LAST NIGHT AT THIS TIME OR RUNNING UP TO
TWO DEGREES WARMER. DEWPOINTS HAVE NOT DROPPED AS MUCH AT WALNUT
RIDGE AND ARE ACTUALLY HIGHER AT JONESBORO THAN LAST NIGHT AT THIS
TIME. EXPECT THERE MAY BE SOME DEWPOINT POOLING AHEAD OF THE FRONT
THIS AFTERNOON. SO THINK NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL MAY BE ON TARGET TO REACH HEAT WARNING CRITERIA AGAIN
TODAY. WILL ISSUE AN EXCESSIVE HEAT WARNING AS A RESULT.
ELSEWHERE...WILL KEEP ONGOING HEAT ADVISORY GOING.
TONIGHT INTO FRIDAY...MODELS INDICATE A LINE OF CONVECTION AHEAD OF
THE APPROACHING FRONT WILL PUSH SOUTHWARD THROUGH THE CWA AND SHOULD
EXIT THE CWA BY FRIDAY AFTERNOON POSSIBLY AS EARLY AS FRIDAY NOON
TIME. HOW MUCH THE LINE STAY INTACT IS A DIFFERENT STORY. THE GFS
MAINTAINS THE LINE THROUGHOUT THE OVERNIGHT HOURS WHILE THE NAM SHOWS
IT DWINDLING AS THE NIGHT PROGRESSES. FOR NOW WILL CONTINUE WILL GO
WITH A RANGE OF 30-50 POPS FOR TONIGHT AND WILL LEAVE POPS MAINLY
FOR JUST NORTH MISSISSIPPI ON FRIDAY. INDICATIONS ARE THAT DRIER AIR
WILL BEGIN TO FILTER INTO NORTHERN PORTIONS OF THE CWA ON FRIDAY SO
DO NOT THINK HEAT ADVISORIES WILL BE NEEDED DESPITE EXPECTING SIMILAR
TEMPERATURES FOR HIGHS.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...EXPECT MAINLY DRY CONDITIONS
THROUGH THE PERIOD AS THE UPPER RIDGE TRIES TO REBUILD IN FROM THE
NORTH AND WEST. NORTHEAST WINDS WILL KEEP DRIER AIR IN THE MIDSOUTH
THROUGH AT LEAST SATURDAY NIGHT. ON SUNDAY...SFC WINDS WILL SWITCH
AROUND TO THE SOUTH AND HIGHER DEWPOINTS WILL BEGIN TO FILTER BACK
INTO THE CWA. LOWS WILL RANGE FROM THE UPPER 60S TO THE MID 70S WITH
HIGHS IN THE LOWER TO UPPER 90S.
MONDAY THROUGH WEDNESDAY...UPPER RIDGE WEAKENS SLIGHTLY MONDAY AND
TUESDAY WHICH MAY ALLOW FOR SOME DIURNAL CONVECTION BUT BY WEDNESDAY
THE RIDGE SEEMS TO RESTRENGTHEN. HIGHS ON MONDAY WILL BE IN THE
LOWER TO MID 90S BUT BY WEDNESDAY EXPECT TEMPERATURES BACK IN THE
MID TO UPPER 90S. LOWS WILL BE IN THE LOWER TO MID 70S.
KRM
&&
.AVIATION...
18Z TAFS
OUTFLOW BOUNDARY THAT MOVED THROUGH THE MIDSOUTH LAST EVENING FROM
THE EAST HAS RESULTED IN AN INITIALLY MORE STABLE LOWER ATMOSPHERE
TO START THE 18Z TAF PERIOD. THE REMNANTS OF THIS BOUNDARY EXTENDED
FROM NEAR TUP...WESTWARD TO 50SM SOUTH OF MEM... TO 70SM SW OF JBR.
BEST TSRA CHANCE WILL BE OVER NORTH MS... SOUTH OF MEM THIS
AFTERNOON. ISOLATED TSRA WILL BE POSSIBLE BEHIND THIS BOUNDARY...
INCLUDING NEAR MEM AFTER 20Z...ONCE CONVECTIVE TEMPS ARE REACHED.
12Z NAM AND 13Z HRRR MODELS SUGGEST A SECONDARY BANDED AREA OF
SHRA/TSRA MOVING SOUTH THROUGH MEM IN THE 01Z TO 03Z TIME FRAME.
THIS ACTIVITY WOULD BE A SOUTHERN PROGRESSION OF PREFRONTAL
SHRA/TSRA THAT WAS OBSERVED ACROSS SOUTH CENTRAL MO AT MIDDAY.
THERE IS SOME DOUBT WHETHER FORCING WILL BE SUFFICIENT TO
OVERCOME A STRENGTHENING CONVECTIVE CAP FOLLOWING SUNSET. GIVEN
MODEL CONSENSUS...HAVE INCLUDED A SHORT TEMPO FOR EARLY EVENING
PERIOD AT MEM.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 100 79 100 78 / 40 40 20 10
MKL 97 76 96 72 / 40 50 20 10
JBR 103 79 100 75 / 40 30 10 0
TUP 94 76 93 77 / 40 50 40 30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR CLAY-
CRAIGHEAD-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-RANDOLPH.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CRITTENDEN-CROSS-
LEE AR-PHILLIPS-ST. FRANCIS.
MO...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-
PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR COAHOMA-DESOTO-
QUITMAN-TATE-TUNICA.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CROCKETT-DYER-
FAYETTE-GIBSON-HAYWOOD-LAKE-LAUDERDALE-MADISON-OBION-SHELBY-
TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
650 PM EDT THU JUL 19 2012
.SYNOPSIS...
A STATIONARY FRONT EXTENDED FROM NEW JERSEY ACROSS THE OHIO VALLEY
INTO KANSAS. LOW PRESSURE WILL MOVE ALONG THIS FRONT REACHING
PENNSYLVANIA BY LATE FRIDAY AND PUSHING A COLD FRONT THROUGH THE
REGION ON SATURDAY. HIGH PRESSURE WILL BE OVER THE AREA MONDAY AND
TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 323 PM EDT THURSDAY...
LINE OF CONVECTION FALLING APART AS IT TRACKS EAST ACROSS THE
MOUNTAINS THIS EVENING. WIND GUSTS OF 20-30KTS MAY BE SEEN AHEAD
OF THE RAIN. ONCE THE HEAVIER SHOWERS PASS...LIGHT RAIN MAY
PERSIST FOR AN HOUR OR TWO.
AS OF 323 PM EDT THURSDAY...
A COLD FRONT IS STRETCHED ACROSS THE NORTHERN OHIO VALLEY AND
INTO PENNSYLVANIA THIS AFTERNOON. A SURFACE WAVE DEVELOPED ALONG
THE FRONT THIS MORNING AND WILL MOVE SLOWLY TO THE EAST OVER THE
NEXT 24 HOURS. THIS WAVE HAS BUCKLED THE FRONT TO THE NORTH THIS
AFTERNOON. THIS FRONT WILL STAY TO THE NORTH...POSSIBLY INTO
FRIDAY NIGHT...LEAVING THE AREA IN THE WARM SECTOR TOMORROW.
EVENTUALLY...THE SURFACE LOW ALONG THE FRONT WILL TRANSFER ENERGY
TO THE LEE TROUGH IN THE PIEDMONT. THE FRONT SHOULD FOLLOW
THEREAFTER. THIS MAY NOT OCCUR UNTIL FRIDAY NIGHT/SATURDAY
MORNING. WITH THE AREA REMAINING IN THE WARM SECTOR...AFTERNOON
TEMPERATURES FRIDAY WILL RUN ABOVE NORMAL AND IN THE M80/L90S.
THE SURFACE LOW HAS A LINE OF CONVECTION ASSOCIATED WITH IT. USING
THE HRRR AND LOCAL WRF...THIS LINE OF SHOWERS WILL ENTER SE WV
AROUND 800 PM THIS EVENING...THEN SPREADS TO THE NEW RIVER VALLEY
WHILE DIMINISHING IN INTENSITY BY MIDNIGHT. KEPT LOW POPS THROUGH THE
NIGHT AS INSTABILITIES LINGER.
STRONG CONVECTION IS EXPECTED FRIDAY AFTERNOON AS THE FRONT
APPROACHES THE REGION. THUNDERSTORM DEVELOPMENT COULD START AS EARLY
AS NOON ACROSS THE WEST THEN SPREADS TO THE EAST LATE AFTERNOON INTO
EARLY EVENING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM EDT THURSDAY...
TROUGH THRU THE NORTHEAST U.S. AND OFF THE MID ATLANTIC COAST THIS
PERIOD WILL BE A FACTOR IN FLOW ALOFT TURNING ANY STORM COMPLEXES
SOUTHEAST TOWARD OUR AREA MIDWEEK. THE 00Z ECMWF SHOWING A DECENT
WAVE MOVING ACROSS WITH A FRONT BY WEDNESDAY AND FOLLOWING IT WILL
HAVE CHANCE POPS CWA WIDE WEDNESDAY INTO WED EVENING. TIMING AND
PATH IS STILL UP IN THE AIR...BUT EXPECT AT LEAST AT SOME POINT NEXT
WEEK TO SEE A GOOD CHANCE OF STORMS. OTHERWISE...WILL STAY ON THE
HUMID SIDE AS THE UPPER RIDGE STAYS JUST WEST OF US AND FRONTS MAY
HAVE A HARD TIME SLICING FAR SOUTH...BUT AGAIN WILL DEPEND IF WE CAN
GET ENOUGH WWD TRANSLATION OF THE EAST COAST TROUGH.
LOOKING AT A WEEK WITH MUGGY LOWS AND SEASONAL HIGHS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 115 PM EDT THURSDAY...
TROUGH THRU THE NORTHEAST U.S. AND OFF THE MID ATLANTIC COAST THIS
PERIOD WILL BE A FACTOR IN FLOW ALOFT TURNING ANY STORM COMPLEXES
SOUTHEAST TOWARD OUR AREA MIDWEEK. THE 00Z ECMWF SHOWING A DECENT
WAVE MOVING ACROSS WITH A FRONT BY WEDNESDAY AND FOLLOWING IT WILL
HAVE CHANCE POPS CWA WIDE WEDNESDAY INTO WED EVENING. TIMING AND
PATH IS STILL UP IN THE AIR...BUT EXPECT AT LEAST AT SOME POINT NEXT
WEEK TO SEE A GOOD CHANCE OF STORMS. OTHERWISE...WILL STAY ON THE
HUMID SIDE AS THE UPPER RIDGE STAYS JUST WEST OF US AND FRONTS MAY
HAVE A HARD TIME SLICING FAR SOUTH...BUT AGAIN WILL DEPEND IF WE CAN
GET ENOUGH WWD TRANSLATION OF THE EAST COAST TROUGH.
LOOKING AT A WEEK WITH MUGGY LOWS AND SEASONAL HIGHS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 647 PM EDT THURSDAY...
LINE OF CONVECTION FALLING APART AS IT TRACKS EAST. WIND GUSTS OF
20-30KTS MAY BE SEEN AHEAD OF THE RAIN. RAIN MAY BRING VISIBILITIES
DOWN TO MVFR FOR AN HOUR OR LESS...THEN REBOUND BACK TO VFR.
CLEARING OVERNIGHT COULD LEAD TO FOG FORMING...ESPECIALLY IN THE
VALLEYS.
SIMILAR WEATHER PATTERN CONTINUES ON FRIDAY WITH MVFR CEILINGS AND
VISIBILITIES DUE TO THUNDERSTORMS IN THE AFTERNOON AND EVENING AND
MVFR FOG OVERNIGHT.
SATURDAY A COLD FRONT APPROACHES THE REGION AND WORKS IN FROM THE
NORTHWEST. THIS WILL RESULT IN MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS.
SATURDAY NIGHT INTO MONDAY...SOME LINGERING SHOWERS/STORMS WILL
STILL BE POSSIBLE...WITH LATE NIGHT/EARLY MORNING MOUNTAIN AND
RIVER VALLEY FOG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...WP
LONG TERM...WP
AVIATION...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
331 PM EDT THU JUL 19 2012
.SYNOPSIS...
A STATIONARY FRONT EXTENDED FROM NEW JERSEY ACROSS THE OHIO VALLEY
INTO KANSAS. LOW PRESSURE WILL MOVE ALONG THIS FRONT REACHING
PENNSYLVANIA BY LATE FRIDAY AND PUSHING A COLD FRONT THROUGH THE
REGION ON SATURDAY. HIGH PRESSURE WILL BE OVER THE AREA MONDAY AND
TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 323 PM EDT THURSDAY...
A COLD FRONT IS STRETCHED ACROSS THE NORTHERN OHIO VALLEY AND
INTO PENNSYLVANIA THIS AFTERNOON. A SURFACE WAVE DEVELOPED ALONG
THE FRONT THIS MORNING AND WILL MOVE SLOWLY TO THE EAST OVER THE
NEXT 24 HOURS. THIS WAVE HAS BUCKLED THE FRONT TO THE NORTH THIS
AFTERNOON. THIS FRONT WILL STAY TO THE NORTH...POSSIBLY INTO
FRIDAY NIGHT...LEAVING THE AREA IN THE WARM SECTOR TOMORROW.
EVENTUALLY...THE SURFACE LOW ALONG THE FRONT WILL TRANSFER ENERGY
TO THE LEE TROUGH IN THE PIEDMONT. THE FRONT SHOULD FOLLOW
THEREAFTER. THIS MAY NOT OCCUR UNTIL FRIDAY NIGHT/SATURDAY
MORNING. WITH THE AREA REMAINING IN THE WARM SECTOR...AFTERNOON
TEMPERATURES FRIDAY WILL RUN ABOVE NORMAL AND IN THE M80/L90S.
THE SURFACE LOW HAS A LINE OF CONVECTION ASSOCIATED WITH IT. USING
THE HRRR AND LOCAL WRF...THIS LINE OF SHOWERS WILL ENTER SE WV
AROUND 800 PM THIS EVENING...THEN SPREADS TO THE NEW RIVER VALLEY
WHILE DIMINISHING IN INTENSITY BY MIDNIGHT. KEPT LOW POPS THROUGH THE
NIGHT AS INSTABILITIES LINGER.
STRONG CONVECTION IS EXPECTED FRIDAY AFTERNOON AS THE FRONT
APPROACHES THE REGION. THUNDERSTORM DEVELOPMENT COULD START AS EARLY
AS NOON ACROSS THE WEST THEN SPREADS TO THE EAST LATE AFTERNOON INTO
EARLY EVENING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM EDT THURSDAY...
TROUGH THRU THE NORTHEAST U.S. AND OFF THE MID ATLANTIC COAST THIS
PERIOD WILL BE A FACTOR IN FLOW ALOFT TURNING ANY STORM COMPLEXES
SOUTHEAST TOWARD OUR AREA MIDWEEK. THE 00Z ECMWF SHOWING A DECENT
WAVE MOVING ACROSS WITH A FRONT BY WEDNESDAY AND FOLLOWING IT WILL
HAVE CHANCE POPS CWA WIDE WEDNESDAY INTO WED EVENING. TIMING AND
PATH IS STILL UP IN THE AIR...BUT EXPECT AT LEAST AT SOME POINT NEXT
WEEK TO SEE A GOOD CHANCE OF STORMS. OTHERWISE...WILL STAY ON THE
HUMID SIDE AS THE UPPER RIDGE STAYS JUST WEST OF US AND FRONTS MAY
HAVE A HARD TIME SLICING FAR SOUTH...BUT AGAIN WILL DEPEND IF WE CAN
GET ENOUGH WWD TRANSLATION OF THE EAST COAST TROUGH.
LOOKING AT A WEEK WITH MUGGY LOWS AND SEASONAL HIGHS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 115 PM EDT THURSDAY...
TROUGH THRU THE NORTHEAST U.S. AND OFF THE MID ATLANTIC COAST THIS
PERIOD WILL BE A FACTOR IN FLOW ALOFT TURNING ANY STORM COMPLEXES
SOUTHEAST TOWARD OUR AREA MIDWEEK. THE 00Z ECMWF SHOWING A DECENT
WAVE MOVING ACROSS WITH A FRONT BY WEDNESDAY AND FOLLOWING IT WILL
HAVE CHANCE POPS CWA WIDE WEDNESDAY INTO WED EVENING. TIMING AND
PATH IS STILL UP IN THE AIR...BUT EXPECT AT LEAST AT SOME POINT NEXT
WEEK TO SEE A GOOD CHANCE OF STORMS. OTHERWISE...WILL STAY ON THE
HUMID SIDE AS THE UPPER RIDGE STAYS JUST WEST OF US AND FRONTS MAY
HAVE A HARD TIME SLICING FAR SOUTH...BUT AGAIN WILL DEPEND IF WE CAN
GET ENOUGH WWD TRANSLATION OF THE EAST COAST TROUGH.
LOOKING AT A WEEK WITH MUGGY LOWS AND SEASONAL HIGHS.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 117 PM EDT THURSDAY...
ANOTHER ROUND OF SLOW MOVING STORMS LIKELY THIS AFTERNOON. SOME OF
THE STRONGER STORMS MAY PRODUCE WIND GUSTS OF AT LEAST 30 KTS. SINCE
HRRR WAS THE CLOSEST TO THE RADAR IMAGE AT 16Z THU...USED THIS MODEL
TO TIME SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. EXPECTING
VICINITY HIT AND MISS STORMS THROUGH MUCH OF THE AFTERNOON...THEN A
MORE ORGANIZED LINE THIS EVENING.
SIMILAR WEATHER PATTERN CONTINUES ON FRIDAY WITH MVFR CEILINGS AND
VISIBILITIES DUE TO THUNDERSTORMS IN THE AFTERNOON AND EVENING AND
MVFR FOG OVERNIGHT.
SATURDAY A COLD FRONT APPROACHES THE REGION AND WORKS IN FROM THE
NORTHWEST. THIS WILL RESULT IN MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS.
SATURDAY NIGHT INTO MONDAY...SOME LINGERING SHOWERS/STORMS WILL
STILL BE POSSIBLE...WITH LATE NIGHT/EARLY MORNING MOUNTAIN AND
RIVER VALLEY FOG.
&&
.EQUIPMENT...
NOAA ALL HAZARDS RADIO FOR THE HINTON TRANSMITTER REMAINS OFF THE
AIR. COMMERCIAL POWER HAS BEEN RESTORED...BUT TELCO SIGNAL IS NOT
REACHING THE SITE. WE ARE TRYING TO ESTABLISH A WIRELESS
CONNECTION TO THE SITE WITH THE HOPES OF BEING ABLE TO TRANSMIT
AGAIN FROM THIS SITE BY THE END OF THIS WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...WP
LONG TERM...WP
AVIATION...RCS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1157 AM CDT THU JUL 19 2012
.UPDATE...SLOWED WARMING AND LOWERED HIGHS A BIT IN OUR NORTHWEST
AS LOW CEILINGS AND LIGHT FOG SEEM TO HAVE LINGERED LATER THAN
ORIGINALLY ANTICIPATED...KEEPING TEMPERATURES IN THE 60S OR LOWER
70S. EDGE OF STRATUS ERODING OVER IOWA AND THINK THIS WILL
EVENTUALLY EXPAND INTO THE SOUTH ALLOWING SOME PARTIAL
CLEARING...SO HIGHS STILL IN THE 80S ACROSS THAT AREA. ALSO THREW
IN A MENTION OF ISOLATED SPRINKLES PRIOR TO 18Z PER FAINT ECHOES
OBSERVED ON RADAR.
&&
.AVIATION/18Z TAFS/...VIS SATELLITE SHOWS BKN-OVC SKIES OVER THE
CWA...WITH AN AREA OF HIGHER CIGS MOVING S-SSE OF A LINE FROM WEST
BEND TO MONROE CAUSING MKE AND UES TO RISE UP TO VFR. ENW SHOULD
SEE A SIMILAR EFFECT WITHIN THE HOUR...AT LEAST TO MVFR.
HOWEVER...THESE CONDITIONS ARE EXPECTED TO BE SHORT-LIVED AS
UPSTREAM LOWER CIGS...IFR TO MVFR...BEHIND THIS LINE MOVES
IN...THOUGH POTENTIAL IMPROVEMENT EXISTS OVER THE COURSE OF THE
DAY. ALSO EVIDENT FROM VIS SATELLITE IS STRATUS ERODING OVER NE
IOWA...THIS IS ANTICIPATED TO SPREAD INTO THE SW OF THE CWA. THIS
EROSION COMBINED WITH BETTER MIXING OUT WEST...AS SEEN VIA BUFKIT
MODEL SOUNDINGS...GIVE REASON TO EXPECT VFR CONDITIONS TO DEVELOP
IN WESTERN HALF OF THE CWA LATE MORNING TO EARLY EVENING...WHILE
THE EAST HALF STAYS IN MVFR. EAST HALF WILL THEN TREND UP TO VFR
BY LATE THURSDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 438 AM CDT THU JUL 19 2012/
VERY SHORT TERM. TODAY AND TONIGHT.
TODAY.....FORECAST CONFIDENCE IS LOW TO MEDIUM.
CURRENT CONVECTION TRACKING OFF TO THE EAST WITH FORCING AHEAD OF
AXIS OF SHORT WAVE TROUGH. TIMING BACK EDGE OF SCATTERED
PRECIPITATION LEAVES JUST THE NORTHEASTERN CWA WITH ANY CHANCE FOR
PCPN AFTER 12Z...IN LINE WITH EXIT OF LAYER FRONTOGENESIS.
LOW CONFIDENCE PORTION OF FORECAST IS WITH SOME OPERATIONAL AND
HI-RES MODELS PAINTING LARGE QPF BULLS-EYES OVER EAST CENTRAL
WISCONSIN ON APEX OF INVERTED SURFACE TROUGH...WITH SOME UPPER
SUPPORT FROM TRAILING VORT MAX CURRENTLY OVER FAR NRN MN ON WATER
VAPOR LOOPS...AND THEN DROPPING IT THROUGH THE FORECAST AREA LATE
THIS MORNING/AFTERNOON IN NORTHERLY FLOW BEHIND SURFACE LOW AS IT
SHIFTS TOWARDS THE EASTERN GREAT LAKES. LACK OF FORCING AND
OVERDONE CAPE ON RAP SOUNDINGS DUE TO LOW TO MID 70 SURFACE DEW
POINTS GIVE LITTLE CONFIDENCE TO OVERALL SCENARIO SO WILL ONLY
KEEP A SLIGHT CHANCE IN THE NORTHEAST LATER THIS MORNING...AND GO
WITH A DRY AFTERNOON WHICH COLLABORATES WITH SURROUNDING OFFICES.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION DEPICTED ON FORECAST
SOUNDINGS PRODUCING FOG AND LOW CLOUDS TO THE NORTHWEST. HAVE ADDED
SOME FOG TO THE FORECAST IN THE WEST FOR THE REMAINDER OF THE
OVERNIGHT HOURS BEHIND PRECIPITATION AND WILL ALSO ADJUST AS NEEDED
AT ISSUANCE FOR THE EARLY MORNING HOURS.
CLOUDS COULD INHIBIT WARMING...ESPECIALLY IN NORTHEAST CWA...BUT
DELAY IN COLD AIR ADVECTION IN THE 925 MB TO 850 MB LAYER AND SOME
THINNING OF CLOUDS IN THE SOUTHWEST LEND SUPPORT TO CONSENSUS HIGHS
FOR TODAY.
TONIGHT...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE SETTLES OVER REGION WITH CORE OF COLDER 925 TO 850 MB
TEMPERATURES SWINGING THROUGH. ONLY MIXING WITH NORTHEAST WINDS
STAYING UP WELL INTO THE OVERNIGHT WILL PREVENT COOLER LOWS THAN
CONSENSUS LOW TO MID 60S.
SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM TO HIGH.
UPPER LEVEL HIGH REMAINS OVER THE CENTRAL HIGH PLAINS DURING THIS
PERIOD...WITH NORTHERLY FLOW SHIFTING NORTHWESTERLY IN THE MID TO
UPPER LEVELS. AT THE SURFACE...HIGH PRESSURE SLIDES SLOWLY
SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION FRIDAY THROUGH
SATURDAY...THEN SLIDES FURTHER SOUTHEAST SATURDAY NIGHT.
GFS/ECMWF/CANADIAN MODELS TRY TO BRING A WEAK COLD FRONT
SOUTHEAST INTO CENTRAL WISCONSIN BY 00Z SUNDAY. THIS IS
ACCOMPANIED BY A SHORTWAVE TROUGH SLIDING SOUTHEAST THROUGH THE
AREA. AREA FORECAST SOUNDINGS ON NAM/GFS SHOWING SOME MID LEVEL
MOISTURE WITH THESE FEATURES...BUT LOW LEVELS REMAIN QUITE DRY.
FOR NOW...WILL KEEP A DRY FORECAST GOING FOR THE FORECAST
AREA...EXCEPT SMALL POPS IN THE FAR NORTHERN COUNTIES LATE
SATURDAY INTO SATURDAY NIGHT WITH THE SHORTWAVE AND WEAK FRONT.
ONSHORE WINDS WILL CONTINUE TO BRING NEAR NORMAL TEMPERATURES
NEAR THE LAKE FRIDAY...WITH 925MB TEMPERATURES FROM THE NAM
SHOWING MID TO UPPER 80S WELL INLAND. LIGHT WINDS AND MOSTLY
CLEAR SKIES SHOULD ALLOW LOWS INTO THE LOWER 60S AWAY FROM THE
LAKE FRIDAY NIGHT.
WARMER AIRMASS MOVES INTO THE AREA FOR SATURDAY...WITH 925MB
TEMPERATURES ALLOWING FOR HIGHS INTO THE LOWER 90S ACROSS MOST OF
THE AREA. HIGHS SHOULD NEAR 90 CLOSE TO SHORE BEFORE LAKE BREEZE
KICKS IN DURING THE AFTERNOON. MILDER LOWS EXPECTED SATURDAY
NIGHT WITH THE WARMER AIRMASS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF SHOW THE UPPER HIGH LINGERING ACROSS THE CENTRAL PLAINS
DURING THIS PERIOD. THIS ALLOWS FOR WEST NORTHWEST MID TO UPPER
LEVEL FLOW ACROSS THE WESTERN GREAT LAKES REGION.
THESE MODELS DO SHOW A VORTICITY MAXIMUM SHIFTING THROUGH THE AREA
SUNDAY...WEAKER ON THE ECMWF THAN THE GFS. BOTH SHOWING QPF...WITH
THE GFS PROBABLY OVERDONE WITH ITS HIGH DEW POINT AND LOW LEVEL
MOISTURE BIAS. WILL LEAVE POPS IN FORECAST FOR SUNDAY...WITH WARM
TEMPERATURES CONTINUING ACROSS THE AREA.
ECMWF/GFS THEN BRING A WEAK COLD FRONT SOUTHWARD THROUGH
WISCONSIN MONDAY AND MONDAY NIGHT...STALLING TO THE WEST OF THE
AREA TUESDAY BEFORE SHIFTING BACK NORTHEAST THROUGH THE AREA AS A
WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. GFS CONTINUES TO BE
AGGRESSIVE WITH QPF THROUGH MOST OF THIS PERIOD...WITH THE ECMWF
HOLDING OFF UNTIL DEVELOPING QPF NEAR WARM FRONT TUESDAY INTO
WEDNESDAY. GFS AGAIN PROBABLY OVERDONE AT TIMES WITH MOIST LOW
LEVELS...BUT ENOUGH LIFT IN LOW LEVELS FOR LOW POPS TO CONTINUE
MONDAY NIGHT...WITH HIGHER CHANCE POPS BY TUESDAY NIGHT AND
WEDNESDAY.
VERY WARM TEMPERATURES WILL CONTINUE THROUGH THE PERIOD...WITH
HIGHS IN THE LOWER TO MID 90S EXPECTED ACROSS MOST LOCATIONS AWAY
FROM THE LAKE. LAKE BREEZES IN THE AFTERNOON PERIODS MAY LIMIT
HIGHS THERE TO THE UPPER 80S TO AROUND 90.
AVIATION/12Z TAFS/...
PRECIPITATION WILL CLEAR EASTERN-MOST TAF SITES BY 12Z. MOISTURE
FROM RAINS TRAPPED UNDER INVERSION ON FORECAST SOUNDINGS SUPPORT
MVFR CEILINGS...MIXING UP TO VFR LEVELS BY LATE MORNING/EARLY
AFTERNOON IN THE WEST...BUT LINGERING IN THE EAST WITH FLOW OFF OF
LAKE MICHIGAN REDUCING POTENTIAL OF INVERSION MIXING OUT. WATCHING
FOR POTENTIAL OF REDUCED VSBYS AS WELL...ESPECIALLY AT KMSN THIS MORNING.
NAM IFR CIGS APPEAR TO BE DUE TO OVERDONE LOW-LEVEL MOISTURE AND
WILL KEEP CIGS NO LOWER THAN MVFR IN THE EAST...TRENDING THEM UP AFTER
00Z FRIDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/JCW
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...WOOD