Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/03/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
316 PM MDT WED AUG 1 2012
.SHORT TERM...THE UPPER LEVEL RIDGE OVER THE TEXAS PANHANDLE WILL
SHIFT FURTHER SOUTH TONIGHT ALLOWING FOR A WEAK WESTERLY FLOW
ALOFT OVER THE REGION ON THURSDAY. THE 16Z HRRR REPRESENTS THE
ONGOING CONVECTION FAIRLY WELL AT THIS TIME. IT ALLOWS FOR THE
MAIN WINDOW OF TSTMS TO MOVE ACROSS THE FOOTHILLS AND URBAN
CORRIDOR THROUGH 00Z AND ACROSS THE NORTHEASTERN PLAINS THROUGH
04Z. THE AMS IS STILL QUITE MOIST WITH PW VALUES AROUND ONE INCH.
WET MICROBURSTS WITH BRIEF HEAVY RAIN...0.5 TO 1 INCH IN 30 MINUTES
AND WIND GUSTS TO 40 KTS. WILL FOLLOW THE TIMING OF THE HRRR
SOLUTION IN THIS EVENINGS PACKAGE. THE AMS IS PROGGED TO STABILIZE
FAIRLY FAST AFTER 04Z. ON THURSDAY...SUBTROPICAL MOISTURE WILL
CONTINUE OVER THE CWFA...WITH SOME SLIGHT DECREASE IN PW VALUES
ADVERTISED WITH THE LOWER LEVELS SLIGHTLY DRIER BELOW 600 MB.
STILL ENUF HOWEVER FOR THE THREAT OF BRIEF HEAVY RAIN SHOWERS.
FCST CAPES ON THE SOUNDINGS IN THE 400-700 J/KG RANGE. WITH THAT
IN MIND...THE SEVERE THREAT WILL BE LOW.
.LONG TERM...NO BIG CHANGES IN FORECAST REASONING THIS TIME
AROUND. IT STILL LOOKS LIKE INCREASING WESTERLY FLOW ACROSS THE
NORTHERN HALF OF THE U.S. WILL BE GOOD ENOUGH TO CUT OFF THE FLOW
OF MONSOONAL MOISTURE FROM THE DESERT SOUTHWEST. IT SEEMS LIKE
FRIDAY IS GOING TO BE THE FIRST DRY DAY OF THE SHORT BREAK FROM
THE MONSOON. WARM TEMPERATURES WILL CONTINUE THROUGH FRIDAY AS NO
CHANGE IN THE LOW LEVEL AIRMASS IS EXPECTED UNTIL SATURDAY
MORNING. THE MOSTLY SUNNY DAY ON FRIDAY WILL ALLOW TEMPERATURES TO
CLIMB BACK INTO THE MID 90S AS THE WEEK DRAWS TO A CLOSE. SAUTRDAY
MORNING WILL BRING A NICE INTRUSION OF COOLER AIR ACROSS THE
FORECAST AREA AS AN UPPER DISTURBANCE CROSSES THE STATE. LOW
TEMPERATURES SATURDAY MORNING MAY DROP INTO THE MID 50S ACROSS THE
PLAINS. THE HUMIDITY LEVELS ASSOCIATED WITH THIS COLD FRONT LOOK
QUESTIONABLE AT THIS POINT...SO I HESITATE TO MENTION TOO MUCH
PRECIPITATION IN THE FOOTHILLS SATURDAY MORNING. SOME AREAS MAY
SEE SOME LIGHT RAIN OR DRIZZLE. BY AFTERNOON...THE AIRMASS BEGINS
DRYING OUT WHILE MODEL SOUNDINGS SHOW THAT A MID LEVEL CAP WILL BE
IN PLACE TO HINDER THE DEVELOPMENT OF ANY SHOWERS. THE ONLY
EXCEPTION TO THIS MIGHT BE THE CENTRAL MOUNTAINS WHERE THE HEATING
OVER THE HIGHER TERRAIN MAY BE ENOUGH TO OVERCOME THE MID-LEVEL
INVERSION. HIGHS ON SATURDAY WILL PROBABLY REMAIN BELOW 90 ACROSS
THE PLAINS. SUNDAY MORNING WILL ALSO BE RELATIVELY CHILLY COMPARED
TO THE PAST FEW WEEKS.
FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...THE MONSOON LOOKS
LIKE IT WILL RE-ESTABLISH ITSELF...AND AFTERNOON THUNDERSTORMS
WILL DEVELOP EACH AFTERNOON. FOR A FEW DAYS AT LEAST...HIGHS WILL
AGAIN BE BACK INTO THE 90S.
&&
.AVIATION...THE PEAK WINDOW FOR TSTMS IN THE DENVER AREA WILL BE
UNTIL THROUGH 00Z THEN THE FOCUS SHOULD SHIFT FURTHER EAST ACROSS
THE ADJACENT PLAINS. BRIEF MVFR CIG AND VSBY RESTRICTIONS POSSIBLE
IF HEAVY RAIN SHOWERS DEVELOP AT THE AIRPORTS. NORTH/NORTHWEST
WINDS WILL TRANSITION TO EAST/SOUTHEASTERLY 01-02Z THEN
SOUTH/SOUTHWESTERLY AFTER 04Z.
&&
.HYDROLOGY...THE MAIN WINDOW FOR TSTMS IN THE FOOTHILLS WILL BE
THROUGH 00Z THEN THE COVERAGE WILL BECOME MORE ISOLATED. BRIEF
HEAVY RAIN THE MAIN ISSUE SO FLASH FLOODING WILL BE A THREAT IN
THE BURN AREAS. THE STRONGER STORMS WILL LIKELY PRODUCE AROUND
0-25-0.50 INCHES IN 30 MINUTES...WITH LESSER CHANCE OF UP TO ONE
INCH. MAIN CONCERN WILL BE TRAINING CELLS SO WILL NEED TO KEEP A
CLOSE EYE ON THAT. TSTMS WITH THE POTENTIAL FOR HEAVY RAINFALL
WILL RETURN THURSDAY AFTERNOON...BUT THE THREAT SHOULD BE SLIGHTLY
LOWER.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....DANKERS
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
157 PM EDT WED AUG 1 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...ESPECIALLY TO WESTERN NEW ENGLAND. WARMER AND MORE
HUMID WEATHER IS EXPECTED FOR THE MIDDLE AND END OF THE WEEK ALONG
WITH A LOW CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY LEADING UP
TO MONDAY WHEN A COLD FRNT SLIDES THRU NEW ENGLAND ALONG AND AHEAD
OF WHICH A LINE OF SHOWERS AND THUNDERSTORMS IS EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
FOG/STRATUS HAS LIFTED AND IS MOVING OFF TO THE EAST. LINGERING
LATE MORNING CLOUDS ESPECIALLY OVER WESTERN AND CENTRAL
SECTIONS. CLEARING IS MOVING IN FROM THE WEST AND WAS REACHING
THE NY/MA BORDER BY 10 AM. BUT WATER VAPOR IMAGERY SHOWS MOIST AIR
OVER EASTERN NY AND WESTERN NEW ENGLAND...SO EXPECT ANY CLEARING
TO FILL IN WITH MORE CLOUDS THIS AFTERNOON.
STABILITY PARAMETERS ARE RATHER MARGINAL FOR THIS
AFTERNOON/EVENING. TOTALS CLIMB TO THE MID 40S...LI FALLS TO
AROUND -3...SURFACE BASED CAPE VALUES 500-800 J/KG. ALL OF THIS
POINTS TO SOME SUPPORT FOR SCATTERED TSTMS BUT QUESTIONABLE FOR
DAMAGING STORMS. PARAMETERS ARE MORE PRONOUNCED OVER EASTERN AND
CENTRAL NY/PA WITH TOTALS 50-52...LI OF -6...SBCAPE 1500-2000
J/KG...AND A THETA-E RIDGE FROM THE ADIRONDAKS TO CENTRAL PA.
PRECIPITABLE WATER VALUES ARE 1.5 TO 1.8 INCHES...SO ANY
SHOWERS/STORMS THAT FORM WOULD HAVE POTENTIAL FOR HEAVY DOWNPOURS.
STORM MOTION FROM THE 12Z ALB SOUNDING IS FROM THE WEST AT 11
KNOTS...WHICH WOULD MEAN THE HEAVY DOWNPOURS WOULD SLOWLY MOVE OUT
OF AN AREA. SO POTENTIAL FOR URBAN/POOR DRAINAGE FLOODING.
PUT IT ALL TOGETHER...HIGHEST POPS WEST AND LOWEST EAST THIS
AFTERNOON/EVENING WITH SHOWERS/TSTMS AND HEAVY DOWNPOURS.
TEMPS/DEWPOINTS GRIDS ARE ON TARGET SO NO CHANGES PLANNED TO THOSE
FORECASTS.
PREVIOUS DISCUSSION...
MAIN CONCERN FOR TODAY IS DEVELOPMENT OF SHOWERS/STORMS AS MID
LEVEL TROUGH AND WEAKENING COLD FRONT HEAD E FROM GREAT LAKES.
AIRMASS REMAINS UNSTABLE TO OUR W ACROSS PA WHERE STORMS HAVE
MAINTAINED THEMSELVES MOST OF THE NIGHT. 3KM HRRR BRINGS SOME OF
THIS WEAKENING ACTIVITY INTO WESTERN NEW ENGLAND AROUND 10 AM.
AFTER THAT DEVELOPMENT OF ADDITIONAL CONVECTION WILL DEPEND ON HOW
MUCH INSTABILITY CAN BE GENERATED. 00Z MODELS CONTINUE TO INDICATE
MORE FAVORABLE CONDITIONS WILL REMAIN TO OUR W THIS AFTERNOON...
BUT MARGINAL INSTABILITY COMBINED WITH WEAK CONVERGENCE ALONG
FRONT AND PLENTY OF LOW LEVEL MOISTURE SHOULD GENERATE MORE
SHOWERS AND STORMS ACROSS WESTERN NEW ENGLAND. SEVERE WEATHER
THREAT REMAINS LOW DUE TO WEAK MID LEVEL LAPSE RATES AND WEAK WIND
FIELDS ALOFT.
TOUGH CALL ON FORECAST HIGHS GIVEN UNCERTAINTY WITH CLOUD COVER
TODAY. LOWERED HIGHS SLIGHTLY WITH BLEND OF GFS/NAM MOS...IN 70S
TO MID 80S WITH WARMEST READINGS ACROSS INTERIOR EASTERN MA.
WEAK PRESSURE GRADIENT SHOULD ALLOW SEA BREEZES TO DEVELOP LATER
THIS MORNING. ALSO OF NOTE IS MODERATE RISK OF RIP CURRENTS WHICH
IS BEING FORECAST FOR CAPE COD AND ISLANDS AS WELL AS E MA COAST
TODAY. THIS IS DUE TO WIND WAVES OF 6-8 FT OFFSHORE TRANSITIONING
INTO E/SE SWELL.
&&
.SHORT TERM /THURSDAY/...
ANY CONVECTION SHOULD DIMINISH THIS EVENING ALBEIT SLOWLY AS
PLENTY OF LOW LEVEL MOISTURE REMAINS IN PLACE. EXPECT RETURN OF
PATCHY LOW CLOUDS AND FOG...ESPECIALLY NEAR COAST WITH LIGHT S/SW
FLOW.
CHANCES FOR SHOWERS/STORMS THU IS LOWER THAN TODAY DESPITE
CONTINUED PRESENCE OF MID LEVEL TROUGH. CROSS SECTIONS SHOW SOME
DRIER AIR WORKING IN ALOFT WHICH SHOULD LIMIT OVERALL CONVECTIVE
POTENTIAL. NONETHELESS WITH S/SW FLOW PROVIDING PLENTY OF LOW
LEVEL MOISTURE AND WEAK BOUNDARY NEARBY...INCLUDED ISOLATED
SHOWERS/STORMS ACROSS INTERIOR THU AFTERNOON. ONCE AGAIN SEVERE
THREAT IS VERY LOW.
ANOTHER LOW IS EXPECTED TO EMERGE OFF CAROLINAS BUT UPPER FLOW IS
PROGRESSIVE ENOUGH TO ALLOW THIS SYSTEM TO PASS WELL SE OF NEW
ENGLAND THU AFTERNOON.
NAM/GFS MOS CLOSE TONIGHT AND THU SO CONTINUED TO RUN WITH A BLEND
OF BOTH. SHOULD COME CLOSE TO 90 THU AFTERNOON IN PARTS OF PIONEER
AND MERRIMACK VALLEYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* HOT AND HUMID CONDITIONS FOR THE END OF THE WEEK INTO THE WEEKEND
* DIURNALLY DRIVEN STORMS PSBL FRIDAY AND SATURDAY
* QUIET WX FOR SUNDAY...COLD FRNT WITH SHOWERS AND THUNDERSTORMS MONDAY
* COOLER AND DRIER WX PSBL BEYOND MONDAY
MODEL DIAGNOSIS...
GENERAL AGREEMENT AMONGST FCST SOLNS CONTINUES TO BE EXHIBITED WITH
INITIAL 01/0Z MODEL GUIDANCE. ONLY SCRUTINY IS A SLIGHTLY FASTER H5
TROF DISTURBANCE ALONG THE US-CANADIAN BORDER AROUND 12Z SATURDAY...
YET BRIEFLY PER 01/0Z GFS WITH THE H5 TROF SLOWING IN ITS APPROACH
EWD AGAINST THE WRN ATLANTIC RIDGE INTO THE END OF THE WEEKEND. THIS
IS NOT SEEN THOUGH IN THE 01/0Z UKMET. AM LEFT TO CONSIDER GREATER
WEIGHT TOWARDS EUROPEAN FCST GUIDANCE...BUT WILL BLEND GFS/NAM FCST
GUIDANCE ACCORDINGLY.
THEREAFTER THERE IS SERIOUS DOUBT WITH THE 01/0Z GFS INVOKING A DEEP
CLOSED LOW ACROSS CENTRAL CANADA GOING AGAINST ITS RESPECTIVE 31/12Z
ENSEMBLE OUTPUT. YET THERE IS SOME UNCERTAINTY WITH THE 31/12Z ECMWF
USHERING THE SRN PLAINS/SRN ROCKIES H5 RIDGE EWD. GLOBAL ENSEMBLE
FCST GUIDANCE IN AGREEMENT OF A NEGATIVE NAO PATTERN FOR THE FIRST
WEEK OF AUGUST...BUT SOLNS BECOME DIVERSE AND THERE IS A LARGE AMNT
OF SPREAD BEYOND. AM EXPECTING A GENERAL TROF PATTERN FOR THE NERN
CONUS INTO THE EARLY PORTION OF NEXT WEEK WITH CONTINUED POS HEIGHT
ANOMALIES AND RIDGING OVER THE WRN ATLANTIC NWD INTO GREENLAND. AS
TO WHETHER THE TROF PATTERN CONTINUES...OR RATHER BREAKS DOWN...
AFTER THE FIRST WEEK OF AUGUST IS FAIRLY UNCERTAIN. AM NOT GIVING
MUCH CONSIDERATION TO THE FCST TUESDAY /7TH/ AND BEYOND.
THURSDAY NIGHT INTO FRIDAY NIGHT...
THE DEPARTURE OF THURS SYSTEM DRAWS WARM MOIST AIR NWD ALONG AND
AHEAD INVOKING POS HEIGHT RISES THRU THE WRN ATLANTIC AND
STRENGTHENING THE BERMUDA HIGH. SUBSEQUENTLY...W/SWLY FLOW IS
ENHANCED ACROSS NEW ENGLAND UNDER A MORE ZONAL FLOW REGIME THEREBY
DRAWING WARM AND MOIST AIR NEWD. MDL FCST SOUNDINGS EXHIBIT CAPPING
AROUND H85 WITH A FAIR AMNT OF ELEVATED INSTABILITY. THERE ARE
SUBTLE HINTS OF WEAK ENERGY ADVECTING THRU THE ZONAL FLOW REGIME
DURING THE DAY FRIDAY...AND WITH THAT BEING SAID THERE IS THE
PLAUSIBILITY OF CONVECTION FORCED VIA CYCLONIC FLOW AND ENHANCED
ASCENT THRU THE CAPPING INVERSION. HEAVY RAIN WILL REMAIN A THREAT
WITH PWAT VALUES AROUND 1.5 INCHES. FEEL ANY CONVECTION WILL BE
ISOLATED /GREATER CHCS ACROSS THE INTERIOR/. AM NOT THINKING
ANYTHING SEVERE. LOOKING AT A VERY HOT AND HUMID DAY FRIDAY.
SATURDAY INTO SATURDAY NIGHT...
FCST GUIDANCE SUGGESTS AN ATTENDANT WEAK WARM FRNTL BOUNDARY PARENT
WITH THE SFC LOW AND H5 TROF ACROSS THE GRT LKS WILL BE THE FOCUS
FOR DIURNALLY FORCED CONVECTION. CAPPING INVERSION AROUND H85 IS
STILL APPARENT AND A STRENGTHENING BERMUDA HIGH TOWARDS THE ERN
CONUS RESULTS IN THE INTRUSION OF DRIER AIR THRU THE MID-LVLS. YET
HEIGHT FALLS ARE EXPECTED ACROSS THE WRN INTERIOR WITH THE APPROACH
OF THE H5 TROF AXIS...AND SHOULD SOME SFC CONVERGENCE PREVAIL ALONG
THE WEAK WARM FRNTL BOUNDARY...FEEL THE WRN INTERIOR WILL HAVE CHC
FOR SHOWERS AND THUNDERSTORMS. NOT COMPLETELY SOLD ON THE OUTCOME...
ITS PSBL THE PERIOD MAY TURN OUT DRY. IF ANY POPS...SLGT CHC. HOT
AND HUMID CONDITIONS CONTINUE FOR THE INTERIOR...COOLER NEAR THE
SHORES.
SUNDAY INTO MONDAY...
SUNDAY APPEARS THE BETTER OF THE TWO DAYS WITH THE RGN FINDING
ITSELF WITHIN THE WARM SECTOR AHEAD OF THE APPROACHING TROF AXIS AND
ATTENDANT COLD FRNT. ANY FORCING MAY BE WELL N OF THE FCST AREA.
OTHERWISE THE MAIN SHOW PREVAILS FOR MONDAY AS A COLD FRNT WITH
SHOWERS AND THUNDERSTORMS SWEEPS THRU THE RGN. AM VERY CONCERNED
WITH THE POSSIBILITY OF HEAVY RAIN AND FLASH FLOODING AS PWATS ARE
ADVERTISED AROUND 2 INCHES /IN SOME CASES 2.5/. NOT CERTAIN STORMS
WILL BE SEVERE /PARAMETERS OF SHEAR APPEAR WEAK WITH MODEST
INSTABILITY THOUGH SKINNY AND THIN THRU THE ATMOS COLUMN/.
TUESDAY AND BEYOND...
WILL PREVAIL A DRY FCST FOR NOW. AS NOTED BY THE PREV FORECASTER...
THE STRONGER WRN ATLANTIC RIDGE MAY SLOW THE PROGRESSION OF THE COLD
FRNT ON MONDAY THEREBY RESULTING IN ACTIVE WX TO LINGER INTO TUE. AS
IT STANDS PRESENTLY...FCST GUIDANCE IS QUICK TO MOVE THE SYS
OFFSHORE AND USHER ACROSS THE RGN COOLER AND DRIER HIGH PRES. WILL
PREVAIL AS SUCH.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THIS AFTERNOON...MODERATE CONFIDENCE
RADAR SHOWS SEVERAL SHOWERS MOVING NORTHEAST THROUGH NORTHERN CT
AND CENTRAL MASS. A SHOWER ALSO POPPED NEAR BOSTON ALONG THE SEA
BREEZE FRONT. EXPECT THIS ACTIVITY TO CONTINUE THROUGH THE EVENING
WHILE FAVORABLE INSTABILITY IS IN PLACE. CIGS ARE GENERALLY AROUND
3500 FEET BUT DIP TO 2500 FEET IN PLACES. SO EXPECT LOW-END
VFR...POSSIBLY BRIEF MVFR IN SHOWERS. SEA BREEZES CONTINUE ALONG
THE COAST THROUGH SUNSET.
TONIGHT...LOW CONFIDENCE
LINGERING CLOUDS OVERNIGHT WITH SOME LIGHT FOG POSSIBLE AFTER
MIDNIGHT. BEST POTENTIAL FOR DENSE FOG WOULD BE AT NANTUCKET. MOST
FOG OVERNIGHT WOULD BE MVFR...WITH IFR IN A FEW SPOTS.
THURSDAY...MODERATE CONFIDENCE
GENERALLY VFR. CLEARING SKIES IN THE MORNING. DIURNAL CLOUDS THEN
DEVELOP. CONDITIONS MARGINAL FOR SCATTERED SHOWERS/TSTMS BUT MAY
BE ISOLATED SHOWERS/STORMS. BRIEF MVFR IN ANY PRECIP.
THURSDAY NIGHT...MODERATE CONFIDENCE.
VFR EARLY. AREAS OF IFR IN FOG AFTER MIDNIGHT.
KBOS TAF...MODERATE CONFIDENCE.
VFR WITH SEA BREEZE. SCATTERED TO WIDELY SCATTERED SHOWERS MAY
DEVELOP ALONG SEA BREEZE IN THE VICINITY OF THE AIRPORT WITH MVFR
CIGS/VSBYS IN ANY PCPN. VFR TONIGHT WITH POTENTIAL FOR MVFR VSBYS
IN FOG LATE AT NIGHT. VFR THURSDAY WITH ISOLATED TSTMS POSSIBLE IN
THE AFTERNOON...MVFR IN ANY PCPN THAT DOES FORM.
KBDL TAF...MODERATE CONFIDENCE.
VFR THIS AFTERNOON/EVENING WITH BRIEF MVFR CIGS/VSBYS IN ANY TSTMS
THAT MOVE THROUGH. ANY STORMS SHOULD BE SLOW MOVING...AND SO LOCALLY
HEAVY DOWNPOURS ARE POSSIBLE WITH IFR CONDITIONS. VFR TONIGHT
WITH POTENTIAL FOR MVFR VSBYS IN PATCHY FOG LATE AT NIGHT. VFR
THURSDAY WITH ISOLATED TSTMS AND RESULTING BRIEF MVFR CIGS/VSBYS.
OUTLOOK...FRIDAY THROUGH MONDAY...
FRIDAY INTO FRIDAY NIGHT... PSBL CONVECTION FRI ACROSS THE
INTERIOR...LOW CONFIDENCE. OTHERWISE PREVAIL VFR WITH MODEST
W/SWLY FLOW. GUSTS OVER SHORELINE TERMINALS AROUND 20 KTS.
SATURDAY INTO SATURDAY NIGHT...
RENEWED CHCS FOR SHRA/TSRA ACROSS THE INTERIOR...LOW CONFIDENCE. SLY
FLOW WITH GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
COLD FRNT APPROACHES WITH SHRA/TSRA ALONG AND AHEAD. SUNDAY VFR WITH
INCREASING SLY FLOW /GUSTS AROUND 20 KTS/. SHOULD REMAIN DRY.
MONDAY...SHRA/TSRA EXPECTED CLEARING LATE INTO TUE MORN.
&&
.MARINE...
WEAKER WINDS THIS AFTERNOON AS SURFACE LOW HEADS OUT TO SEA.
AFTERNOON SEA BREEZES EXPECTED. S/SW FLOW PREVAILS TONIGHT AND
THU WITH PATCHY LATE NIGHT AND EARLY MORNING FOG.
LOW PRESSURE SHOULD PASS WELL S AND E OF NEW ENGLAND THU BUT WE
MAY SEE SEAS OF 5-6 FT REACH OUTER WATERS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
W/SWLY FLOW BECOMING SLY WITH GUSTS AROUND 20 KTS FOR THE S WATERS
WILL INVOKE SEAS OF 5 FT ALL THE WAY INTO THE LOCAL SOUNDS AND BAYS.
NOT EXPECTING ANY STORMS.
SATURDAY INTO SATURDAY NIGHT...
SLY FLOW WILL REMAIN BRISK BUT WEAKER ENOUGH TO ALLOW SWELL TO
DIMINISH. GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
SLY FLOW INCREASING INTO SUNDAY IN RESPONSE TO APPROACHING COLD
FRNT. SEAS BUILDING ALONG THE S AND E WATERS IN RESPONSE. COLD FRNT
TO SLIDE ACROSS THE WATERS LATE MONDAY ALONG AND AHEAD OF WHICH
SHOWERS AND THUNDERSTORMS ARE EXPECTED AND LIKELY TO LINGER INTO THE
TUE MORN HRS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SIPPRELL/JWD
NEAR TERM...WTB/SIPPRELL/JWD
SHORT TERM...JWD
LONG TERM...SIPPRELL
AVIATION...WTB/SIPPRELL
MARINE...SIPPRELL/JWD/WTB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1040 AM EDT WED AUG 1 2012
.SYNOPSIS...
LOW PRESSURE OVER THE GULF OF MAINE THIS MORNING WILL MOVE OFF
THROUGH THE MARITIMES THIS AFTERNOON. A WEAKENING COLD FRONT WILL
BRING SHOWERS AND THUNDERSTORMS THIS AFTERNOON...ESPECIALLY TO
WESTERN NEW ENGLAND. WARMER AND MORE HUMID WEATHER IS EXPECTED FOR
THE MIDDLE AND END OF THE WEEK ALONG WITH A LOW CHANCE OF SHOWERS
AND THUNDERSTORMS EACH DAY LEADING UP TO MONDAY WHEN A COLD FRNT
SLIDES THRU NEW ENGLAND ALONG AND AHEAD OF WHICH A LINE OF SHOWERS
AND THUNDERSTORMS IS EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
FOG/STRATUS HAS LIFTED AND IS MOVING OFF TO THE EAST. LINGERING
LATE MORNING CLOUDS ESPECIALLY OVER WESTERN AND CENTRAL
SECTIONS. CLEARING IS MOVING IN FROM THE WEST AND WAS REACHING
THE NY/MA BORDER BY 10 AM. BUT WATER VAPOR IMAGERY SHOWS MOIST AIR
OVER EASTERN NY AND WESTERN NEW ENGLAND...SO EXPECT ANY CLEARING
TO FILL IN WITH MORE CLOUDS THIS AFTERNOON.
STABILITY PARAMETERS ARE RATHER MARGINAL FOR THIS
AFTERNOON/EVENING. TOTALS CLIMB TO THE MID 40S...LI FALLS TO
AROUND -3...SURFACE BASED CAPE VALUES 500-800 J/KG. ALL OF THIS
POINTS TO SOME SUPPORT FOR SCATTERED TSTMS BUT QUESTIONABLE FOR
DAMAGING STORMS. PARAMETERS ARE MORE PRONOUNCED OVER EASTERN AND
CENTRAL NY/PA WITH TOTALS 50-52...LI OF -6...SBCAPE 1500-2000
J/KG...AND A THETA-E RIDGE FROM THE ADIRONDAKS TO CENTRAL PA.
PRECIPITABLE WATER VALUES ARE 1.5 TO 1.8 INCHES...SO ANY
SHOWERS/STORMS THAT FORM WOULD HAVE POTENTIAL FOR HEAVY DOWNPOURS.
STORM MOTION FROM THE 12Z ALB SOUNDING IS FROM THE WEST AT 11
KNOTS...WHICH WOULD MEAN THE HEAVY DOWNPOURS WOULD SLOWLY MOVE OUT
OF AN AREA. SO POTENTIAL FOR URBAN/POOR DRAINAGE FLOODING.
PUT IT ALL TOGETHER...HIGHEST POPS WEST AND LOWEST EAST THIS
AFTERNOON/EVENING WITH SHOWERS/TSTMS AND HEAVY DOWNPOURS.
TEMPS/DEWPOINTS GRIDS ARE ON TARGET SO NO CHANGES PLANNED TO THOSE
FORECASTS.
PREVIOUS DISCUSSION...
MAIN CONCERN FOR TODAY IS DEVELOPMENT OF SHOWERS/STORMS AS MID
LEVEL TROUGH AND WEAKENING COLD FRONT HEAD E FROM GREAT LAKES.
AIRMASS REMAINS UNSTABLE TO OUR W ACROSS PA WHERE STORMS HAVE
MAINTAINED THEMSELVES MOST OF THE NIGHT. 3KM HRRR BRINGS SOME OF
THIS WEAKENING ACTIVITY INTO WESTERN NEW ENGLAND AROUND 10 AM.
AFTER THAT DEVELOPMENT OF ADDITIONAL CONVECTION WILL DEPEND ON HOW
MUCH INSTABILITY CAN BE GENERATED. 00Z MODELS CONTINUE TO INDICATE
MORE FAVORABLE CONDITIONS WILL REMAIN TO OUR W THIS AFTERNOON...
BUT MARGINAL INSTABILITY COMBINED WITH WEAK CONVERGENCE ALONG
FRONT AND PLENTY OF LOW LEVEL MOISTURE SHOULD GENERATE MORE
SHOWERS AND STORMS ACROSS WESTERN NEW ENGLAND. SEVERE WEATHER
THREAT REMAINS LOW DUE TO WEAK MID LEVEL LAPSE RATES AND WEAK WIND
FIELDS ALOFT.
TOUGH CALL ON FORECAST HIGHS GIVEN UNCERTAINTY WITH CLOUD COVER
TODAY. LOWERED HIGHS SLIGHTLY WITH BLEND OF GFS/NAM MOS...IN 70S
TO MID 80S WITH WARMEST READINGS ACROSS INTERIOR EASTERN MA.
WEAK PRESSURE GRADIENT SHOULD ALLOW SEA BREEZES TO DEVELOP LATER
THIS MORNING. ALSO OF NOTE IS MODERATE RISK OF RIP CURRENTS WHICH
IS BEING FORECAST FOR CAPE COD AND ISLANDS AS WELL AS E MA COAST
TODAY. THIS IS DUE TO WIND WAVES OF 6-8 FT OFFSHORE TRANSITIONING
INTO E/SE SWELL.
&&
.SHORT TERM /THURSDAY/...
ANY CONVECTION SHOULD DIMINISH THIS EVENING ALBEIT SLOWLY AS
PLENTY OF LOW LEVEL MOISTURE REMAINS IN PLACE. EXPECT RETURN OF
PATCHY LOW CLOUDS AND FOG...ESPECIALLY NEAR COAST WITH LIGHT S/SW
FLOW.
CHANCES FOR SHOWERS/STORMS THU IS LOWER THAN TODAY DESPITE
CONTINUED PRESENCE OF MID LEVEL TROUGH. CROSS SECTIONS SHOW SOME
DRIER AIR WORKING IN ALOFT WHICH SHOULD LIMIT OVERALL CONVECTIVE
POTENTIAL. NONETHELESS WITH S/SW FLOW PROVIDING PLENTY OF LOW
LEVEL MOISTURE AND WEAK BOUNDARY NEARBY...INCLUDED ISOLATED
SHOWERS/STORMS ACROSS INTERIOR THU AFTERNOON. ONCE AGAIN SEVERE
THREAT IS VERY LOW.
ANOTHER LOW IS EXPECTED TO EMERGE OFF CAROLINAS BUT UPPER FLOW IS
PROGRESSIVE ENOUGH TO ALLOW THIS SYSTEM TO PASS WELL SE OF NEW
ENGLAND THU AFTERNOON.
NAM/GFS MOS CLOSE TONIGHT AND THU SO CONTINUED TO RUN WITH A BLEND
OF BOTH. SHOULD COME CLOSE TO 90 THU AFTERNOON IN PARTS OF PIONEER
AND MERRIMACK VALLEYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* HOT AND HUMID CONDITIONS FOR THE END OF THE WEEK INTO THE WEEKEND
* DIURNALLY DRIVEN STORMS PSBL FRIDAY AND SATURDAY
* QUIET WX FOR SUNDAY...COLD FRNT WITH SHOWERS AND THUNDERSTORMS MONDAY
* COOLER AND DRIER WX PSBL BEYOND MONDAY
MODEL DIAGNOSIS...
GENERAL AGREEMENT AMONGST FCST SOLNS CONTINUES TO BE EXHIBITED WITH
INITIAL 01/0Z MODEL GUIDANCE. ONLY SCRUTINY IS A SLIGHTLY FASTER H5
TROF DISTURBANCE ALONG THE US-CANADIAN BORDER AROUND 12Z SATURDAY...
YET BRIEFLY PER 01/0Z GFS WITH THE H5 TROF SLOWING IN ITS APPROACH
EWD AGAINST THE WRN ATLANTIC RIDGE INTO THE END OF THE WEEKEND. THIS
IS NOT SEEN THOUGH IN THE 01/0Z UKMET. AM LEFT TO CONSIDER GREATER
WEIGHT TOWARDS EUROPEAN FCST GUIDANCE...BUT WILL BLEND GFS/NAM FCST
GUIDANCE ACCORDINGLY.
THEREAFTER THERE IS SERIOUS DOUBT WITH THE 01/0Z GFS INVOKING A DEEP
CLOSED LOW ACROSS CENTRAL CANADA GOING AGAINST ITS RESPECTIVE 31/12Z
ENSEMBLE OUTPUT. YET THERE IS SOME UNCERTAINTY WITH THE 31/12Z ECMWF
USHERING THE SRN PLAINS/SRN ROCKIES H5 RIDGE EWD. GLOBAL ENSEMBLE
FCST GUIDANCE IN AGREEMENT OF A NEGATIVE NAO PATTERN FOR THE FIRST
WEEK OF AUGUST...BUT SOLNS BECOME DIVERSE AND THERE IS A LARGE AMNT
OF SPREAD BEYOND. AM EXPECTING A GENERAL TROF PATTERN FOR THE NERN
CONUS INTO THE EARLY PORTION OF NEXT WEEK WITH CONTINUED POS HEIGHT
ANOMALIES AND RIDGING OVER THE WRN ATLANTIC NWD INTO GREENLAND. AS
TO WHETHER THE TROF PATTERN CONTINUES...OR RATHER BREAKS DOWN...
AFTER THE FIRST WEEK OF AUGUST IS FAIRLY UNCERTAIN. AM NOT GIVING
MUCH CONSIDERATION TO THE FCST TUESDAY /7TH/ AND BEYOND.
THURSDAY NIGHT INTO FRIDAY NIGHT...
THE DEPARTURE OF THURS SYSTEM DRAWS WARM MOIST AIR NWD ALONG AND
AHEAD INVOKING POS HEIGHT RISES THRU THE WRN ATLANTIC AND
STRENGTHENING THE BERMUDA HIGH. SUBSEQUENTLY...W/SWLY FLOW IS
ENHANCED ACROSS NEW ENGLAND UNDER A MORE ZONAL FLOW REGIME THEREBY
DRAWING WARM AND MOIST AIR NEWD. MDL FCST SOUNDINGS EXHIBIT CAPPING
AROUND H85 WITH A FAIR AMNT OF ELEVATED INSTABILITY. THERE ARE
SUBTLE HINTS OF WEAK ENERGY ADVECTING THRU THE ZONAL FLOW REGIME
DURING THE DAY FRIDAY...AND WITH THAT BEING SAID THERE IS THE
PLAUSIBILITY OF CONVECTION FORCED VIA CYCLONIC FLOW AND ENHANCED
ASCENT THRU THE CAPPING INVERSION. HEAVY RAIN WILL REMAIN A THREAT
WITH PWAT VALUES AROUND 1.5 INCHES. FEEL ANY CONVECTION WILL BE
ISOLATED /GREATER CHCS ACROSS THE INTERIOR/. AM NOT THINKING
ANYTHING SEVERE. LOOKING AT A VERY HOT AND HUMID DAY FRIDAY.
SATURDAY INTO SATURDAY NIGHT...
FCST GUIDANCE SUGGESTS AN ATTENDANT WEAK WARM FRNTL BOUNDARY PARENT
WITH THE SFC LOW AND H5 TROF ACROSS THE GRT LKS WILL BE THE FOCUS
FOR DIURNALLY FORCED CONVECTION. CAPPING INVERSION AROUND H85 IS
STILL APPARENT AND A STRENGTHENING BERMUDA HIGH TOWARDS THE ERN
CONUS RESULTS IN THE INTRUSION OF DRIER AIR THRU THE MID-LVLS. YET
HEIGHT FALLS ARE EXPECTED ACROSS THE WRN INTERIOR WITH THE APPROACH
OF THE H5 TROF AXIS...AND SHOULD SOME SFC CONVERGENCE PREVAIL ALONG
THE WEAK WARM FRNTL BOUNDARY...FEEL THE WRN INTERIOR WILL HAVE CHC
FOR SHOWERS AND THUNDERSTORMS. NOT COMPLETELY SOLD ON THE OUTCOME...
ITS PSBL THE PERIOD MAY TURN OUT DRY. IF ANY POPS...SLGT CHC. HOT
AND HUMID CONDITIONS CONTINUE FOR THE INTERIOR...COOLER NEAR THE
SHORES.
SUNDAY INTO MONDAY...
SUNDAY APPEARS THE BETTER OF THE TWO DAYS WITH THE RGN FINDING
ITSELF WITHIN THE WARM SECTOR AHEAD OF THE APPROACHING TROF AXIS AND
ATTENDANT COLD FRNT. ANY FORCING MAY BE WELL N OF THE FCST AREA.
OTHERWISE THE MAIN SHOW PREVAILS FOR MONDAY AS A COLD FRNT WITH
SHOWERS AND THUNDERSTORMS SWEEPS THRU THE RGN. AM VERY CONCERNED
WITH THE POSSIBILITY OF HEAVY RAIN AND FLASH FLOODING AS PWATS ARE
ADVERTISED AROUND 2 INCHES /IN SOME CASES 2.5/. NOT CERTAIN STORMS
WILL BE SEVERE /PARAMETERS OF SHEAR APPEAR WEAK WITH MODEST
INSTABILITY THOUGH SKINNY AND THIN THRU THE ATMOS COLUMN/.
TUESDAY AND BEYOND...
WILL PREVAIL A DRY FCST FOR NOW. AS NOTED BY THE PREV FORECASTER...
THE STRONGER WRN ATLANTIC RIDGE MAY SLOW THE PROGRESSION OF THE COLD
FRNT ON MONDAY THEREBY RESULTING IN ACTIVE WX TO LINGER INTO TUE. AS
IT STANDS PRESENTLY...FCST GUIDANCE IS QUICK TO MOVE THE SYS
OFFSHORE AND USHER ACROSS THE RGN COOLER AND DRIER HIGH PRES. WILL
PREVAIL AS SUCH.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THIS AFTERNOON THROUGH THURSDAY...MODERATE CONFIDENCE.
LINGERING 1000-2000 FOOT CEILINGS AROUND SOUTHERN NEW ENGLAND LATE
MORNING SHOULD SCATTER OUT THIS AFTERNOON. EXPECT VFR CEILINGS
THIS AFTERNOON WITH SHOWERS/TSTMS DEVELOPING THIS AFTERNOON. BEST
CHANCE FOR THIS WILL BE IN THE CT VALLEY AND EAST SLOPES OF THE
BERKSHIRES...LOWEST CHANCE WOULD BE ALONG THE MASS EAST COAST.
PSBL LOW CIGS AND VSBYS WILL RETURN TONIGHT /BETTER CHCS ALONG
THE IMMEDIATE COAST/. WILL ALLOW LATER SHIFTS TO INTERPRET WITH
FUTURE SETS OF TAFS...DID NOT PREVAIL DUE TO LOW CONFIDENCE.
EXPECT VFR FOR THURS WITH PSBL ISOLATED STORMS BY THE AFTN HRS
MAINLY ACROSS INTERIOR TERMINALS.
KBOS TAF...MODERATE CONFIDENCE.
VFR WITH DEVELOPING SEA BREEZE MIDDAY. POTENTIAL FOR AN HOUR OR
TWO OF 1500 FOOT CEILINGS AROUND MIDDAY. SHOWERS/TSTMS DEVELOPING
NORTH AND WEST OF THE AIRPORT BUT WILL LIKELY STAY NORTH AND WEST
THROUGH EVENING. VFR TONIGHT WITH POTENTIAL FOR MVFR VSBY IN FOG.
VFR THURSDAY WITH ISOLATED TSTMS AND BRIEF MVFR CIGS/VSBYS.
KBDL TAF...MODERATE CONFIDENCE.
VFR CIGS/VSBYS BUT WITH POTENTIAL FOR AN HOUR OR TWO OF MVFR
MIDDAY. SHOWERS/TSTMS DEVELOP THIS AFTERNOON WITH BRIEF MVFR/IFR
IN ANY PCPN. ANY STORMS SHOULD BE SLOW MOVING...AND SO LOCALLY
HEAVY DOWNPOURS ARE POSSIBLE WITH IFR CONDITIONS. VFR TONIGHT WITH
MVFR VSBYS IN PATCHY FOG LATE AT NIGHT. VFR THURSDAY WITH ISOLATED
TSTMS AND BRIEF MVFR CIGS/VSBYS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
PSBL CONVECTION FRI ACROSS THE INTERIOR...LOW CONFIDENCE. OTHERWISE
PREVAIL VFR WITH MODEST W/SWLY FLOW. GUSTS OVER SHORELINE TERMINALS
AROUND 20 KTS.
SATURDAY INTO SATURDAY NIGHT...
RENEWED CHCS FOR SHRA/TSRA ACROSS THE INTERIOR...LOW CONFIDENCE. SLY
FLOW WITH GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
COLD FRNT APPROACHES WITH SHRA/TSRA ALONG AND AHEAD. SUNDAY VFR WITH
INCREASING SLY FLOW /GUSTS AROUND 20 KTS/. SHOULD REMAIN DRY.
MONDAY...SHRA/TSRA EXPECTED CLEARING LATE INTO TUE MORN.
&&
.MARINE...
SCA REMAINS POSTED INTO AFTERNOON FOR THE EASTERN OUTER WATERS AS
WINDS AND SEAS CONTINUE TO DIMINISH.
WEAKER WINDS THIS AFTERNOON AS SURFACE LOW HEADS OUT TO SEA.
AFTERNOON SEA BREEZES EXPECTED. S/SW FLOW PREVAILS TONIGHT AND
THU WITH PATCHY LATE NIGHT AND EARLY MORNING FOG.
LOW PRESSURE SHOULD PASS WELL S AND E OF NEW ENGLAND THU BUT WE
MAY SEE SEAS OF 5-6 FT REACH OUTER WATERS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
W/SWLY FLOW BECOMING SLY WITH GUSTS AROUND 20 KTS FOR THE S WATERS
WILL INVOKE SEAS OF 5 FT ALL THE WAY INTO THE LOCAL SOUNDS AND BAYS.
NOT EXPECTING ANY STORMS.
SATURDAY INTO SATURDAY NIGHT...
SLY FLOW WILL REMAIN BRISK BUT WEAKER ENOUGH TO ALLOW SWELL TO
DIMINISH. GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
SLY FLOW INCREASING INTO SUNDAY IN RESPONSE TO APPROACHING COLD
FRNT. SEAS BUILDING ALONG THE S AND E WATERS IN RESPONSE. COLD FRNT
TO SLIDE ACROSS THE WATERS LATE MONDAY ALONG AND AHEAD OF WHICH
SHOWERS AND THUNDERSTORMS ARE EXPECTED AND LIKELY TO LINGER INTO THE
TUE MORN HRS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ250-
254-255.
&&
$$
SYNOPSIS...SIPPRELL/JWD
NEAR TERM...WTB/SIPPRELL/JWD
SHORT TERM...JWD
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/JWD
MARINE...SIPPRELL/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
712 AM EDT WED AUG 1 2012
.SYNOPSIS...
LOW PRESSURE OVER THE GULF OF MAINE THIS MORNING WILL HEAD FARTHER
OUT TO SEA TODAY. A WEAKENING COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...ESPECIALLY TO WESTERN NEW ENGLAND.
WARMER AND MORE HUMID WEATHER IS EXPECTED FOR THE MIDDLE AND END
OF THE WEEK ALONG WITH A LOW CHANCE OF SHOWERS AND THUNDERSTORMS
EACH DAY LEADING UP TO MONDAY WHEN A COLD FRNT SLIDES THRU NEW
ENGLAND ALONG AND AHEAD OF WHICH A LINE OF SHOWERS AND
THUNDERSTORMS IS EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
7 AM UPDATE...
CLUSTER OF SHOWERS MOVING THRU THE NYC METRO LIKELY A RESULT OF
A LOCALIZED LOW-LVL JET ABOVE THE SFC INVERSION AND BELOW A
SHALLOW RGN /AROUND H7/ OF STEEP LAPSE RATES AND ELEVATED
INSTABILITY. VERY LITTLE IF ANY LIGHTNING ASSOCIATED WITH THE
CLUSTER AGREEING WITH FCST MDL SOUNDINGS HIGHLIGHTING MUCH OF THE
ELEVATED INSTABILITY BELOW THE FRZG MARK /AND MORE IMPORTANTLY
-10C/. ENERGY IS GRADUALLY FIZZLING...BUT IT IS PLAUSIBLE TO SEE
SOME OF THAT ENERGY IMPACT THE LOWER CT VLY BY 13-14Z.
OTHERWISE EXPECTING ADDITIONAL ENERGY TO BLOSSOM UPSTREAM ALONG
AND AHEAD OF THE SFC COLD FRNT PRESENTLY ACROSS THE ERN GRT LKS...
BETTER CHCS FOR SHOWERS AND THUNDERSTORMS WILL ERUPT AS THE SUN
RISES AND QUICKLY MIXES OUT THE BOUNDARY LYR /FOG AND LOW STRATUS
TO SUBSEQUENTLY DISSIPATE/. PER MDL FCST SOUNDINGS...INSTABILITY
IS THIN AND ELONGATED THRU THE ATMOS COLUMN...A MAJORITY OF WHICH
IS BELOW THE BETTER FRZG LVLS. AM IN BELIEF THAT ANY CONVECTION
WILL BE ISOLATED TO SCATTERED AND SUB-SEVERE. PWATS ARE HIGH
/AROUND 1.75 INCHES/ SO THERE IS THE THREAT FOR HEAVY DOWNPOURS
AND LOCALIZED FLOODING WITH ANY STORMS.
PREVIOUS DISCUSSION...
MAIN CONCERN FOR TODAY IS DEVELOPMENT OF SHOWERS/STORMS AS MID
LEVEL TROUGH AND WEAKENING COLD FRONT HEAD E FROM GREAT LAKES.
AIRMASS REMAINS UNSTABLE TO OUR W ACROSS PA WHERE STORMS HAVE
MAINTAINED THEMSELVES MOST OF THE NIGHT. 3KM HRRR BRINGS SOME OF
THIS WEAKENING ACTIVITY INTO WESTERN NEW ENGLAND AROUND 10 AM.
AFTER THAT DEVELOPMENT OF ADDITIONAL CONVECTION WILL DEPEND ON HOW
MUCH INSTABILITY CAN BE GENERATED. 00Z MODELS CONTINUE TO INDICATE
MORE FAVORABLE CONDITIONS WILL REMAIN TO OUR W THIS AFTERNOON...
BUT MARGINAL INSTABILITY COMBINED WITH WEAK CONVERGENCE ALONG
FRONT AND PLENTY OF LOW LEVEL MOISTURE SHOULD GENERATE MORE
SHOWERS AND STORMS ACROSS WESTERN NEW ENGLAND. SEVERE WEATHER
THREAT REMAINS LOW DUE TO WEAK MID LEVEL LAPSE RATES AND WEAK WIND
FIELDS ALOFT.
TOUGH CALL ON FORECAST HIGHS GIVEN UNCERTAINTY WITH CLOUD COVER
TODAY. LOWERED HIGHS SLIGHTLY WITH BLEND OF GFS/NAM MOS...IN 70S
TO MID 80S WITH WARMEST READINGS ACROSS INTERIOR EASTERN MA.
WEAK PRESSURE GRADIENT SHOULD ALLOW SEA BREEZES TO DEVELOP LATER
THIS MORNING. ALSO OF NOTE IS MODERATE RISK OF RIP CURRENTS WHICH
IS BEING FORECAST FOR CAPE COD AND ISLANDS AS WELL AS E MA COAST
TODAY. THIS IS DUE TO WIND WAVES OF 6-8 FT OFFSHORE TRANSITIONING
INTO E/SE SWELL.
&&
.SHORT TERM /THURSDAY/...
ANY CONVECTION SHOULD DIMINISH THIS EVENING ALBEIT SLOWLY AS
PLENTY OF LOW LEVEL MOISTURE REMAINS IN PLACE. EXPECT RETURN OF
PATCHY LOW CLOUDS AND FOG...ESPECIALLY NEAR COAST WITH LIGHT S/SW
FLOW.
CHANCES FOR SHOWERS/STORMS THU IS LOWER THAN TODAY DESPITE
CONTINUED PRESENCE OF MID LEVEL TROUGH. CROSS SECTIONS SHOW SOME
DRIER AIR WORKING IN ALOFT WHICH SHOULD LIMIT OVERALL CONVECTIVE
POTENTIAL. NONETHELESS WITH S/SW FLOW PROVIDING PLENTY OF LOW
LEVEL MOISTURE AND WEAK BOUNDARY NEARBY...INCLUDED ISOLATED
SHOWERS/STORMS ACROSS INTERIOR THU AFTERNOON. ONCE AGAIN SEVERE
THREAT IS VERY LOW.
ANOTHER LOW IS EXPECTED TO EMERGE OFF CAROLINAS BUT UPPER FLOW IS
PROGRESSIVE ENOUGH TO ALLOW THIS SYSTEM TO PASS WELL SE OF NEW
ENGLAND THU AFTERNOON.
NAM/GFS MOS CLOSE TONIGHT AND THU SO CONTINUED TO RUN WITH A BLEND
OF BOTH. SHOULD COME CLOSE TO 90 THU AFTERNOON IN PARTS OF PIONEER
AND MERRIMACK VALLEYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* HOT AND HUMID CONDITIONS FOR THE END OF THE WEEK INTO THE WEEKEND
* DIURNALLY DRIVEN STORMS PSBL FRIDAY AND SATURDAY
* QUIET WX FOR SUNDAY...COLD FRNT WITH SHOWERS AND THUNDERSTORMS MONDAY
* COOLER AND DRIER WX PSBL BEYOND MONDAY
MODEL DIAGNOSIS...
GENERAL AGREEMENT AMONGST FCST SOLNS CONTINUES TO BE EXHIBITED WITH
INITIAL 01/0Z MODEL GUIDANCE. ONLY SCRUTINY IS A SLIGHTLY FASTER H5
TROF DISTURBANCE ALONG THE US-CANADIAN BORDER AROUND 12Z SATURDAY...
YET BRIEFLY PER 01/0Z GFS WITH THE H5 TROF SLOWING IN ITS APPROACH
EWD AGAINST THE WRN ATLANTIC RIDGE INTO THE END OF THE WEEKEND. THIS
IS NOT SEEN THOUGH IN THE 01/0Z UKMET. AM LEFT TO CONSIDER GREATER
WEIGHT TOWARDS EUROPEAN FCST GUIDANCE...BUT WILL BLEND GFS/NAM FCST
GUIDANCE ACCORDINGLY.
THEREAFTER THERE IS SERIOUS DOUBT WITH THE 01/0Z GFS INVOKING A DEEP
CLOSED LOW ACROSS CENTRAL CANADA GOING AGAINST ITS RESPECTIVE 31/12Z
ENSEMBLE OUTPUT. YET THERE IS SOME UNCERTAINTY WITH THE 31/12Z ECMWF
USHERING THE SRN PLAINS/SRN ROCKIES H5 RIDGE EWD. GLOBAL ENSEMBLE
FCST GUIDANCE IN AGREEMENT OF A NEGATIVE NAO PATTERN FOR THE FIRST
WEEK OF AUGUST...BUT SOLNS BECOME DIVERSE AND THERE IS A LARGE AMNT
OF SPREAD BEYOND. AM EXPECTING A GENERAL TROF PATTERN FOR THE NERN
CONUS INTO THE EARLY PORTION OF NEXT WEEK WITH CONTINUED POS HEIGHT
ANOMALIES AND RIDGING OVER THE WRN ATLANTIC NWD INTO GREENLAND. AS
TO WHETHER THE TROF PATTERN CONTINUES...OR RATHER BREAKS DOWN...
AFTER THE FIRST WEEK OF AUGUST IS FAIRLY UNCERTAIN. AM NOT GIVING
MUCH CONSIDERATION TO THE FCST TUESDAY /7TH/ AND BEYOND.
THURSDAY NIGHT INTO FRIDAY NIGHT...
THE DEPARTURE OF THURS SYSTEM DRAWS WARM MOIST AIR NWD ALONG AND
AHEAD INVOKING POS HEIGHT RISES THRU THE WRN ATLANTIC AND
STRENGTHENING THE BERMUDA HIGH. SUBSEQUENTLY...W/SWLY FLOW IS
ENHANCED ACROSS NEW ENGLAND UNDER A MORE ZONAL FLOW REGIME THEREBY
DRAWING WARM AND MOIST AIR NEWD. MDL FCST SOUNDINGS EXHIBIT CAPPING
AROUND H85 WITH A FAIR AMNT OF ELEVATED INSTABILITY. THERE ARE
SUBTLE HINTS OF WEAK ENERGY ADVECTING THRU THE ZONAL FLOW REGIME
DURING THE DAY FRIDAY...AND WITH THAT BEING SAID THERE IS THE
PLAUSIBILITY OF CONVECTION FORCED VIA CYCLONIC FLOW AND ENHANCED
ASCENT THRU THE CAPPING INVERSION. HEAVY RAIN WILL REMAIN A THREAT
WITH PWAT VALUES AROUND 1.5 INCHES. FEEL ANY CONVECTION WILL BE
ISOLATED /GREATER CHCS ACROSS THE INTERIOR/. AM NOT THINKING
ANYTHING SEVERE. LOOKING AT A VERY HOT AND HUMID DAY FRIDAY.
SATURDAY INTO SATURDAY NIGHT...
FCST GUIDANCE SUGGESTS AN ATTENDANT WEAK WARM FRNTL BOUNDARY PARENT
WITH THE SFC LOW AND H5 TROF ACROSS THE GRT LKS WILL BE THE FOCUS
FOR DIURNALLY FORCED CONVECTION. CAPPING INVERSION AROUND H85 IS
STILL APPARENT AND A STRENGTHENING BERMUDA HIGH TOWARDS THE ERN
CONUS RESULTS IN THE INTRUSION OF DRIER AIR THRU THE MID-LVLS. YET
HEIGHT FALLS ARE EXPECTED ACROSS THE WRN INTERIOR WITH THE APPROACH
OF THE H5 TROF AXIS...AND SHOULD SOME SFC CONVERGENCE PREVAIL ALONG
THE WEAK WARM FRNTL BOUNDARY...FEEL THE WRN INTERIOR WILL HAVE CHC
FOR SHOWERS AND THUNDERSTORMS. NOT COMPLETELY SOLD ON THE OUTCOME...
ITS PSBL THE PERIOD MAY TURN OUT DRY. IF ANY POPS...SLGT CHC. HOT
AND HUMID CONDITIONS CONTINUE FOR THE INTERIOR...COOLER NEAR THE
SHORES.
SUNDAY INTO MONDAY...
SUNDAY APPEARS THE BETTER OF THE TWO DAYS WITH THE RGN FINDING
ITSELF WITHIN THE WARM SECTOR AHEAD OF THE APPROACHING TROF AXIS AND
ATTENDANT COLD FRNT. ANY FORCING MAY BE WELL N OF THE FCST AREA.
OTHERWISE THE MAIN SHOW PREVAILS FOR MONDAY AS A COLD FRNT WITH
SHOWERS AND THUNDERSTORMS SWEEPS THRU THE RGN. AM VERY CONCERNED
WITH THE POSSIBILITY OF HEAVY RAIN AND FLASH FLOODING AS PWATS ARE
ADVERTISED AROUND 2 INCHES /IN SOME CASES 2.5/. NOT CERTAIN STORMS
WILL BE SEVERE /PARAMETERS OF SHEAR APPEAR WEAK WITH MODEST
INSTABILITY THOUGH SKINNY AND THIN THRU THE ATMOS COLUMN/.
TUESDAY AND BEYOND...
WILL PREVAIL A DRY FCST FOR NOW. AS NOTED BY THE PREV FORECASTER...
THE STRONGER WRN ATLANTIC RIDGE MAY SLOW THE PROGRESSION OF THE COLD
FRNT ON MONDAY THEREBY RESULTING IN ACTIVE WX TO LINGER INTO TUE. AS
IT STANDS PRESENTLY...FCST GUIDANCE IS QUICK TO MOVE THE SYS
OFFSHORE AND USHER ACROSS THE RGN COOLER AND DRIER HIGH PRES. WILL
PREVAIL AS SUCH.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
AM ANTICIPATING CONDITIONS TO GRADUALLY IMPROVE TO VFR INTO THE
MID-MORNING HRS WITH THE INCREASE OF SHRA AND PSBL TSRA INTO THE
MIDDAY AND AFTN HRS. LOW CONFIDENCE WITH TSRA SO REMOVED FROM TAF.
FEEL TSRA CHCS WILL BE ISOLATED TO SCT. ANY SHRA/TSRA IMPACTS WILL
LIKELY RESULT IN MVFR-IFR VSBY IMPACTS /PSBL MVFR CIGS BUT WILL
PREVAIL VFR/. LESSER CHANCE OF TSTMS E OF MHT-ORH-IJD. PSBL LOW
CIGS AND VSBYS WILL RETURN TONIGHT /BETTER CHCS ALONG THE
IMMEDIATE COAST/. WILL ALLOW LATER SHIFTS TO INTERPRET WITH FUTURE
SETS OF TAFS...DID NOT PREVAIL DUE TO LOW CONFIDENCE. EXPECT VFR
FOR THURS WITH PSBL ISOLATED STORMS BY THE AFTN HRS MAINLY ACROSS
INTERIOR TERMINALS.
KBOS TAF...MODERATE CONFIDENCE.
IFR TO GRADUALLY LIFT INTO MORNING BY WHICH TIME HEATING OF THE
DAY MAY PROMOTE A SEA-BREEZE AROUND 16Z. AM NOT CONFIDENT AFTN
SHRA WILL IMPACT THE TERMINAL BUT WILL WATCH CLOSELY.
KBDL TAF...MODERATE CONFIDENCE.
MVFR CIGS TO GRADUALLY LIFT ALLOWING FOR THE DEVELOPMENT OF SHRA
AND PSBL TSRA INTO THE MIDDAY TO AFTN PD. SHOULD ANY STORMS IMPACT
THE TERMINAL...MVFR-IFR VSBYS PSBL.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
PSBL CONVECTION FRI ACROSS THE INTERIOR...LOW CONFIDENCE. OTHERWISE
PREVAIL VFR WITH MODEST W/SWLY FLOW. GUSTS OVER SHORELINE TERMINALS
AROUND 20 KTS.
SATURDAY INTO SATURDAY NIGHT...
RENEWED CHCS FOR SHRA/TSRA ACROSS THE INTERIOR...LOW CONFIDENCE. SLY
FLOW WITH GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
COLD FRNT APPROACHES WITH SHRA/TSRA ALONG AND AHEAD. SUNDAY VFR WITH
INCREASING SLY FLOW /GUSTS AROUND 20 KTS/. SHOULD REMAIN DRY.
MONDAY...SHRA/TSRA EXPECTED CLEARING LATE INTO TUE MORN.
&&
.MARINE...
SCA REMAINS POSTED INTO AFTERNOON FOR OUTER WATERS AS WINDS AND
SEAS CONTINUE TO DIMINISH.
WEAKER GRADIENT TODAY AS SURFACE LOW HEADS OUT TO SEA WITH
AFTERNOON SEA BREEZES EXPECTED. S/SW FLOW PREVAILS TONIGHT AND THU
WITH PATCHY LATE NIGHT AND EARLY MORNING FOG.
LOW PRESSURE SHOULD PASS WELL S AND E OF NEW ENGLAND THU BUT WE
MAY SEE SEAS OF 5-6 FT REACH OUTER WATERS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
W/SWLY FLOW BECOMING SLY WITH GUSTS AROUND 20 KTS FOR THE S WATERS
WILL INVOKE SEAS OF 5 FT ALL THE WAY INTO THE LOCAL SOUNDS AND BAYS.
NOT EXPECTING ANY STORMS.
SATURDAY INTO SATURDAY NIGHT...
SLY FLOW WILL REMAIN BRISK BUT WEAKER ENOUGH TO ALLOW SWELL TO
DIMINISH. GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
SLY FLOW INCREASING INTO SUNDAY IN RESPONSE TO APPROACHING COLD
FRNT. SEAS BUILDING ALONG THE S AND E WATERS IN RESPONSE. COLD FRNT
TO SLIDE ACROSS THE WATERS LATE MONDAY ALONG AND AHEAD OF WHICH
SHOWERS AND THUNDERSTORMS ARE EXPECTED AND LIKELY TO LINGER INTO THE
TUE MORN HRS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ250-
254-255.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ256.
&&
$$
SYNOPSIS...SIPPRELL/JWD
NEAR TERM...SIPPRELL/JWD
SHORT TERM...JWD
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/JWD
MARINE...SIPPRELL/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
310 AM EDT WED AUG 1 2012
.SYNOPSIS...
LOW PRESSURE OVER THE GULF OF MAINE THIS MORNING WILL HEAD FARTHER
OUT TO SEA TODAY. A WEAKENING COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...ESPECIALLY TO WESTERN NEW ENGLAND.
WARMER AND MORE HUMID WEATHER IS EXPECTED FOR THE MIDDLE AND END
OF THE WEEK ALONG WITH A LOW CHANCE OF SHOWERS AND THUNDERSTORMS
EACH DAY.
&&
.NEAR TERM /THROUGH TODAY/...
310 AM UPDATE...
LAST OF SHOWERS WERE EXITING EASTERN MA COAST AS LOW PRESSURE
HEADS ACROSS GULF OF MAINE EARLY THIS MORNING. CLOUDS REMAIN
LOCKED IN ACROSS REGION FROM LEFTOVER MOISTURE AND CLEARING IS NOT
EXPECTED TO TAKE PLACE UNTIL MID MORNING.
MAIN CONCERN FOR TODAY IS DEVELOPMENT OF SHOWERS/STORMS AS MID
LEVEL TROUGH AND WEAKENING COLD FRONT HEAD E FROM GREAT LAKES.
AIRMASS REMAINS UNSTABLE TO OUR W ACROSS PA WHERE STORMS HAVE
MAINTAINED THEMSELVES MOST OF THE NIGHT. 3KM HRRR BRINGS SOME OF
THIS WEAKENING ACTIVITY INTO WESTERN NEW ENGLAND AROUND 10 AM.
AFTER THAT DEVELOPMENT OF ADDITIONAL CONVECTION WILL DEPEND ON HOW
MUCH INSTABILITY CAN BE GENERATED. 00Z MODELS CONTINUE TO INDICATE
MORE FAVORABLE CONDITIONS WILL REMAIN TO OUR W THIS AFTERNOON...
BUT MARGINAL INSTABILITY COMBINED WITH WEAK CONVERGENCE ALONG
FRONT AND PLENTY OF LOW LEVEL MOISTURE SHOULD GENERATE MORE
SHOWERS AND STORMS ACROSS WESTERN NEW ENGLAND. SEVERE WEATHER
THREAT REMAINS LOW DUE TO WEAK MID LEVEL LAPSE RATES AND WEAK WIND
FIELDS ALOFT.
TOUGH CALL ON FORECAST HIGHS GIVEN UNCERTAINTY WITH CLOUD COVER
TODAY. LOWERED HIGHS SLIGHTLY WITH BLEND OF GFS/NAM MOS...IN 70S
TO MID 80S WITH WARMEST READINGS ACROSS INTERIOR EASTERN MA.
WEAK PRESSURE GRADIENT SHOULD ALLOW SEA BREEZES TO DEVELOP LATER
THIS MORNING. ALSO OF NOTE IS MODERATE RISK OF RIP CURRENTS WHICH
IS BEING FORECAST FOR CAPE COD AND ISLANDS AS WELL AS E MA COAST
TODAY. THIS IS DUE TO WIND WAVES OF 6-8 FT OFFSHORE TRANSITIONING
INTO E/SE SWELL.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
ANY CONVECTION SHOULD DIMINISH THIS EVENING ALBEIT SLOWLY AS
PLENTY OF LOW LEVEL MOISTURE REMAINS IN PLACE. EXPECT RETURN OF
PATCHY LOW CLOUDS AND FOG...ESPECIALLY NEAR COAST WITH LIGHT S/SW
FLOW.
CHANCES FOR SHOWERS/STORMS THU IS LOWER THAN TODAY DESPITE
CONTINUED PRESENCE OF MID LEVEL TROUGH. CROSS SECTIONS SHOW SOME
DRIER AIR WORKING IN ALOFT WHICH SHOULD LIMIT OVERALL CONVECTIVE
POTENTIAL. NONETHELESS WITH S/SW FLOW PROVIDING PLENTY OF LOW
LEVEL MOISTURE AND WEAK BOUNDARY NEARBY...INCLUDED ISOLATED
SHOWERS/STORMS ACROSS INTERIOR THU AFTERNOON. ONCE AGAIN SEVERE
THREAT IS VERY LOW.
ANOTHER LOW IS EXPECTED TO EMERGE OFF CAROLINAS BUT UPPER FLOW IS
PROGRESSIVE ENOUGH TO ALLOW THIS SYSTEM TO PASS WELL SE OF NEW
ENGLAND THU AFTERNOON.
NAM/GFS MOS CLOSE TONIGHT AND THU SO CONTINUED TO RUN WITH A BLEND
OF BOTH. SHOULD COME CLOSE TO 90 THU AFTERNOON IN PARTS OF PIONEER
AND MERRIMACK VALLEYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* HOT AND HUMID CONDITIONS FOR THE END OF THE WEEK INTO THE WEEKEND
* DIURNALLY DRIVEN STORMS PSBL FRIDAY AND SATURDAY
* QUIET WX FOR SUNDAY...COLD FRNT WITH SHOWERS AND THUNDERSTORMS MONDAY
* COOLER AND DRIER WX PSBL BEYOND MONDAY
MODEL DIAGNOSIS...
GENERAL AGREEMENT AMONGST FCST SOLNS CONTINUES TO BE EXHIBITED WITH
INITIAL 01/0Z MODEL GUIDANCE. ONLY SCRUTINY IS A SLIGHTLY FASTER H5
TROF DISTURBANCE ALONG THE US-CANADIAN BORDER AROUND 12Z SATURDAY...
YET BRIEFLY PER 01/0Z GFS WITH THE H5 TROF SLOWING IN ITS APPROACH
EWD AGAINST THE WRN ATLANTIC RIDGE INTO THE END OF THE WEEKEND. THIS
IS NOT SEEN THOUGH IN THE 01/0Z UKMET. AM LEFT TO CONSIDER GREATER
WEIGHT TOWARDS EUROPEAN FCST GUIDANCE...BUT WILL BLEND GFS/NAM FCST
GUIDANCE ACCORDINGLY.
THEREAFTER THERE IS SERIOUS DOUBT WITH THE 01/0Z GFS INVOKING A DEEP
CLOSED LOW ACROSS CENTRAL CANADA GOING AGAINST ITS RESPECTIVE 31/12Z
ENSEMBLE OUTPUT. YET THERE IS SOME UNCERTAINTY WITH THE 31/12Z ECMWF
USHERING THE SRN PLAINS/SRN ROCKIES H5 RIDGE EWD. GLOBAL ENSEMBLE
FCST GUIDANCE IN AGREEMENT OF A NEGATIVE NAO PATTERN FOR THE FIRST
WEEK OF AUGUST...BUT SOLNS BECOME DIVERSE AND THERE IS A LARGE AMNT
OF SPREAD BEYOND. AM EXPECTING A GENERAL TROF PATTERN FOR THE NERN
CONUS INTO THE EARLY PORTION OF NEXT WEEK WITH CONTINUED POS HEIGHT
ANOMALIES AND RIDGING OVER THE WRN ATLANTIC NWD INTO GREENLAND. AS
TO WHETHER THE TROF PATTERN CONTINUES...OR RATHER BREAKS DOWN...
AFTER THE FIRST WEEK OF AUGUST IS FAIRLY UNCERTAIN. AM NOT GIVING
MUCH CONSIDERATION TO THE FCST TUESDAY /7TH/ AND BEYOND.
THURSDAY NIGHT INTO FRIDAY NIGHT...
THE DEPARTURE OF THURS SYSTEM DRAWS WARM MOIST AIR NWD ALONG AND
AHEAD INVOKING POS HEIGHT RISES THRU THE WRN ATLANTIC AND
STRENGTHENING THE BERMUDA HIGH. SUBSEQUENTLY...W/SWLY FLOW IS
ENHANCED ACROSS NEW ENGLAND UNDER A MORE ZONAL FLOW REGIME THEREBY
DRAWING WARM AND MOIST AIR NEWD. MDL FCST SOUNDINGS EXHIBIT CAPPING
AROUND H85 WITH A FAIR AMNT OF ELEVATED INSTABILITY. THERE ARE
SUBTLE HINTS OF WEAK ENERGY ADVECTING THRU THE ZONAL FLOW REGIME
DURING THE DAY FRIDAY...AND WITH THAT BEING SAID THERE IS THE
PLAUSIBILITY OF CONVECTION FORCED VIA CYCLONIC FLOW AND ENHANCED
ASCENT THRU THE CAPPING INVERSION. HEAVY RAIN WILL REMAIN A THREAT
WITH PWAT VALUES AROUND 1.5 INCHES. FEEL ANY CONVECTION WILL BE
ISOLATED /GREATER CHCS ACROSS THE INTERIOR/. AM NOT THINKING
ANYTHING SEVERE. LOOKING AT A VERY HOT AND HUMID DAY FRIDAY.
SATURDAY INTO SATURDAY NIGHT...
FCST GUIDANCE SUGGESTS AN ATTENDANT WEAK WARM FRNTL BOUNDARY PARENT
WITH THE SFC LOW AND H5 TROF ACROSS THE GRT LKS WILL BE THE FOCUS
FOR DIURNALLY FORCED CONVECTION. CAPPING INVERSION AROUND H85 IS
STILL APPARENT AND A STRENGTHENING BERMUDA HIGH TOWARDS THE ERN
CONUS RESULTS IN THE INTRUSION OF DRIER AIR THRU THE MID-LVLS. YET
HEIGHT FALLS ARE EXPECTED ACROSS THE WRN INTERIOR WITH THE APPROACH
OF THE H5 TROF AXIS...AND SHOULD SOME SFC CONVERGENCE PREVAIL ALONG
THE WEAK WARM FRNTL BOUNDARY...FEEL THE WRN INTERIOR WILL HAVE CHC
FOR SHOWERS AND THUNDERSTORMS. NOT COMPLETELY SOLD ON THE OUTCOME...
ITS PSBL THE PERIOD MAY TURN OUT DRY. IF ANY POPS...SLGT CHC. HOT
AND HUMID CONDITIONS CONTINUE FOR THE INTERIOR...COOLER NEAR THE
SHORES.
SUNDAY INTO MONDAY...
SUNDAY APPEARS THE BETTER OF THE TWO DAYS WITH THE RGN FINDING
ITSELF WITHIN THE WARM SECTOR AHEAD OF THE APPROACHING TROF AXIS AND
ATTENDANT COLD FRNT. ANY FORCING MAY BE WELL N OF THE FCST AREA.
OTHERWISE THE MAIN SHOW PREVAILS FOR MONDAY AS A COLD FRNT WITH
SHOWERS AND THUNDERSTORMS SWEEPS THRU THE RGN. AM VERY CONCERNED
WITH THE POSSIBILITY OF HEAVY RAIN AND FLASH FLOODING AS PWATS ARE
ADVERTISED AROUND 2 INCHES /IN SOME CASES 2.5/. NOT CERTAIN STORMS
WILL BE SEVERE /PARAMETERS OF SHEAR APPEAR WEAK WITH MODEST
INSTABILITY THOUGH SKINNY AND THIN THRU THE ATMOS COLUMN/.
TUESDAY AND BEYOND...
WILL PREVAIL A DRY FCST FOR NOW. AS NOTED BY THE PREV FORECASTER...
THE STRONGER WRN ATLANTIC RIDGE MAY SLOW THE PROGRESSION OF THE COLD
FRNT ON MONDAY THEREBY RESULTING IN ACTIVE WX TO LINGER INTO TUE. AS
IT STANDS PRESENTLY...FCST GUIDANCE IS QUICK TO MOVE THE SYS
OFFSHORE AND USHER ACROSS THE RGN COOLER AND DRIER HIGH PRES. WILL
PREVAIL AS SUCH.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE...MAINLY THIS MORNING DUE TO
UNCERTAINTY IN HOW QUICKLY CONDITIONS IMPROVE.
IFR/LIFR EXPECTED TO BECOME MORE WIDEPSPREAD BEFORE DAYBREAK...
ALTHOUGH AM MORE CONFIDENT THIS WILL BE CASE NEAR COAST AS OPPOSED
TO INTERIOR. SHOULD SEE IMPROVEMENT TO VFR BY MID TO LATE MORNING
ALTHOUGH CAPE COD TERMINALS MAY REMAIN MVFR OR EVEN IFR THROUGH
MUCH OF DAY WITH LIGHT S/SE FLOW.
SHOWERS AND TSTMS WILL DEVELOP AFTER 16Z ACROSS WESTERN NEW
ENGLAND WITH LOCAL MVFR/IFR. STORMS WILL BE SLOW MOVING WITH HEAVY
RAIN BEING MAIN THREAT. LESSER CHANCE OF TSTMS E OF MHT-ORH-IJD.
LOW CIGS RETURN TONIGHT WITH MVFR/IFR CONDITIONS...LIFR MORE
LIKELY ALONG IMMEDIATE COAST. CIGS LIFT BY MID MORNING THU WITH
VFR EXPECTED THROUGH AFTERNOON. ONLY ANTICIPATE ISOLD
SHOWERS/TSTMS THU AFTERNOON...MAINLY ACROSS INTERIOR.
KBOS TAF...MODERATE CONFIDENCE.
FAIRLY CONFIDENT ON RETURN TO IFR CIGS BEFORE DAYBREAK...BEFORE
CONDITIONS IMPROVE BY MID MORNING. GRADIENT LOOKS WEAK ENOUGH TO
SUPPORT SEA BREEZE BY 15Z. LOW CHANCE OF TSTMS 20Z-23Z.
KBDL TAF...MODERATE CONFIDENCE.
UNCERTAINTY AS TO IFR CIGS DEVELOPING BEFORE DAYBREAK SO TAF
REFLECTS MVFR CIGS. CONDITIONS SHOULD IMPROVE QUICKLY AFTER
SUNRISE. MAIN WINDOW FOR TSTMS 15Z-18Z BUT MAY BE AS LATE AS
18Z-21Z.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
PSBL CONVECTION FRI ACROSS THE INTERIOR...LOW CONFIDENCE. OTHERWISE
PREVAIL VFR WITH MODEST W/SWLY FLOW. GUSTS OVER SHORELINE TERMINALS
AROUND 20 KTS.
SATURDAY INTO SATURDAY NIGHT...
RENEWED CHCS FOR SHRA/TSRA ACROSS THE INTERIOR...LOW CONFIDENCE. SLY
FLOW WITH GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
COLD FRNT APPROACHES WITH SHRA/TSRA ALONG AND AHEAD. SUNDAY VFR WITH
INCREASING SLY FLOW /GUSTS AROUND 20 KTS/. SHOULD REMAIN DRY.
MONDAY...SHRA/TSRA EXPECTED CLEARING LATE INTO TUE MORN.
&&
.MARINE...
SCA REMAINS POSTED INTO AFTERNOON FOR OUTER WATERS AS WINDS AND
SEAS CONTINUE TO DIMINISH.
WEAKER GRADIENT TODAY AS SURFACE LOW HEADS OUT TO SEA WITH
AFTERNOON SEA BREEZES EXPECTED. S/SW FLOW PREVAILS TONIGHT AND THU
WITH PATCHY LATE NIGHT AND EARLY MORNING FOG.
LOW PRESSURE SHOULD PASS WELL S AND E OF NEW ENGLAND THU BUT WE
MAY SEE SEAS OF 5-6 FT REACH OUTER WATERS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY NIGHT...
W/SWLY FLOW BECOMING SLY WITH GUSTS AROUND 20 KTS FOR THE S WATERS
WILL INVOKE SEAS OF 5 FT ALL THE WAY INTO THE LOCAL SOUNDS AND BAYS.
NOT EXPECTING ANY STORMS.
SATURDAY INTO SATURDAY NIGHT...
SLY FLOW WILL REMAIN BRISK BUT WEAKER ENOUGH TO ALLOW SWELL TO
DIMINISH. GUSTS AROUND 15 KTS.
SUNDAY INTO MONDAY...
SLY FLOW INCREASING INTO SUNDAY IN RESPONSE TO APPROACHING COLD
FRNT. SEAS BUILDING ALONG THE S AND E WATERS IN RESPONSE. COLD FRNT
TO SLIDE ACROSS THE WATERS LATE MONDAY ALONG AND AHEAD OF WHICH
SHOWERS AND THUNDERSTORMS ARE EXPECTED AND LIKELY TO LINGER INTO THE
TUE MORN HRS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ250-
254-255.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ256.
&&
$$
SYNOPSIS...SIPPRELL/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/JWD
MARINE...SIPPRELL/JWD
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1252 AM EDT WED AUG 1 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM EAST OF NEW JERSEY WILL MOVE THROUGH THE NEW
ENGLAND COASTAL WATERS TONIGHT. A WEAK COLD FRONT MOVING THROUGH THE
GREAT LAKES WILL DISSIPATE BEFORE REACHING THE FORECAST AREA ON
WEDNESDAY. A SECOND LOW PRESSURE WILL DEVELOP OVER THE SOUTHEAST
STATES WEDNESDAY AND TRACK WELL OFF THE NEW JERSEY COAST ON
THURSDAY. A BERMUDA HIGH PRESSURE SYSTEM WILL THEN BUILD INTO THE
WESTERN ATLANTIC FOR THE REST OF THE WEEK. IT WILL STOP THE
PROGRESSION OF ANOTHER COLD FRONT AS IT TRIES TO EXIT THE SAINT
LAWRENCE VALLEY ON SATURDAY. A THIRD AND SLIGHTLY STRONGER COLD
FRONT IS FORECAST TO MOVE THROUGH THE GREAT LAKES ON SUNDAY AND
SLOWLY MOVE THROUGH OUR FORECAST AREA ON MONDAY BEFORE STALLING
SOUTH OF THE REGION ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LINE OF THUNDERSTORMS APPROACHING FROM SOUTH CENTRAL
PENNSYLVANIA IS FALLING APART...AS IT OUTRUNS ITS INSTABILITY
SOURCE. A FEW GUSTS TO 40 MPH ARE POSSIBLE WITH THE STORMS AS THEY
REACH THE LEHIGH VALLEY AND POSSIBLE SOUTHEAST PENNSYLVANIA.
HOWEVER...THE OVERALL WEAKENING TREND SHOULD CONTINUE AS THE LOW
LEVEL STABILIZE AHEAD OF THE AREA OF SHOWERS AND THUNDERSTORMS.
THE LATEST HRRR TRIES TO KEEP THIS LINE INTACT AS IT APPROACHES
PHILADELPHIA AFTER 0300 UTC. THIS IS LOOK MORE LIKELY NOW BASED ON
THE TREND OF THE AREAL MOVEMENT. THE UPTICK IN ACTIVITY WAS
INCLUDED IN THE MOST RECENT FORECAST UPDATE.
A BRIEF LULL IS EXPECTED BEFORE MORE SHOWERS APPROACH FROM THE
WEST DURING THE LATE OVERNIGHT HOURS AS A FRONTAL BOUNDARY PUSHES
EAST. TEMPERATURES ARE EXPECTED TO BOTTOM OUT IN THE LOW 60S NORTH
AND IN THE UPPER 60S SOUTH. WITH DEW POINT TEMPERATURES WITHIN A
DEGREE OR TWO OF THESE LOWS...SOME PATCHY FOG IS POSSIBLE TOWARD
MORNING. LIGHT AND VARIABLE WINDS DURING THE OVERNIGHT HOURS ARE
EXPECTED TO BECOME SOUTHERLY TOWARD MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
SHOWERS...AND POSSIBLY A THUNDERSTORM OR TWO...ARE EXPECTED TO
APPROACH OUR WESTERN COUNTIES DURING THE LATE OVERNIGHT HOURS...THEN
OVERSPREAD THE REST OF OUR FORECAST AREA AS THE DAY WEARS ON. GIVEN
THE AMOUNT OF MOISTURE AVAILABLE IN THE ATMOSPHERE...SOME HEAVY
DOWNPOURS ARE POSSIBLE ON WEDNESDAY. THESE DOWNPOURS ARE EXPECTED TO
BE ISOLATED...BUT WHERE THEY DO OCCUR...THEY COULD PRODUCE A
SIGNIFICANT AMOUNT OF RAIN IN A SHORT PERIOD OF TIME. TEMPERATURES
ARE EXPECTED TO MAX OUT IN THE MID 80S MOST PLACES GIVEN A GOOD
CLOUD COVER AND RAIN CONDITIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NO BIG CHANGES TO THE LONG TERM VS YESTERDAY AS THE TROFINESS IN
THE EASTERN CONUS WILL BE REPLACED BY A MORE ZONAL FLOW. THIS WILL
BRING THE RETURN OF A HOTTER AND MORE HUMID AIR MASS INTO MONDAY
WITH THE POSSIBILITY OF SOME DRYING AND LESSER POSSIBILITY OF
"COOLING" ON TUESDAY.
WHILE THE GFS INITIALIZATION LOOKED BETTER AT 500MB, ITS PERFECTLY
SPHERICAL GRID SCALE PRODUCED LOW PRESSURE SYSTEMS IN THE SHORT TERM
HAS MADE US DISCARD IT FOR THE LONG TERM. THE PASSING OF A STRONGER
LOW PRESSURE SYSTEM FASTER ON THURSDAY IS ILLOGICAL. STRONGER
SHOULD BE SLOWER AND STRONGER SOLUTIONS SHOULD NOT OCCUR AS TROFS
ARE SHEARING. OUR SOLUTION IN THE NEARER END OF THE SHORT TERM
WAS TOWARD A WRF-NMMB AND ECMWF COMPROMISE AND AN ECMWF-HPC
COMPROMISE IN THE REST OF THE LONG TERM. THE GFS HAS NOT BEEN
ALONE WITH THESE LOWS COMING OFF THE SE COAST, DP/DTING SOME
CANADIAN AND WRF-NMMB SOLUTIONS HAS SHOWN LOW NUMBER ONE WAS
OVERFORECAST IN STRENGTH ALSO.
THE IMPULSE ASSOCIATED WITH THE DISSIPATING COLD FRONT WILL CONTINUE
TO MOVE THROUGH OUR CWA ON WEDNESDAY EVENING AND WE MAINTAIN
RELATIVELY HIGH POPS FOR THE START OF THE OVERNIGHT AND MAINLY IN
THE OFFSHORE WATERS LATE. STAT GUIDANCE LOOKS REASONABLE AND WAS
FOLLOWED.
ON THURSDAY THE FASTER AND STRONGER GFS AND STRONGER CAN GGEM WERE
DISCOUNTED AS LIKELY BEING AFFECTED BY GRIDSCALE FEEDBACK EFFECTS.
OUR SOLUTION IS CLOSEST TO THE WRF-NMMB TRACK AND STRENGTH. THIS
WOULD ALLOW ENOUGH SEPARATION BETWEEN SYSTEMS FOR SCATTERED
THUNDERSTORMS TO DEVELOP DURING THE DAY. HIGHEST POPS WERE PLACED IN
THE DELAWARE VALLEY WHERE CONSENSUS HIEST FCST CAPES EXIST. BECAUSE
OF THE STRONG SYSTEM, GFS MOS MAX TEMPS ARE LOWER ON THU. WE ARE
OPTING FOR A WARMER AIR MASS AND ARE CLOSER TO NAM MOS.
PRECIPITATION SHOULD BE DIURNALLY DRIVEN AND AS WE APPROACH THE 72HR
ITS HARD TO ACCEPT THAT THE WRF-NMMB IS GOING TO VERIFY ITS TIMING
AND PLACEMENT WITH THE OVERNIGHT SHORTWAVE NORTH. SO POPS WERE
DROPPED QUICKLY THURSDAY EVENING. MIN TEMPS WERE A STAT GUIDANCE
COMPROMISE.
FRIDAY MIGHT STILL BE THE "DRY POPLESS DAY". BUT FOR NOW, MODEL
FORECAST SOUNDINGS DO NOT SHOW A STRONG ENOUGH CAP. POPS WERE PLACED
NORTHWEST WHERE HIEST FCST INSTABILITY WAS SHOWN BY THE MAJORITY OF
MODELS. HERE WE DO NOT THINK THAT THE WRF-NMMB SOLUTION OF
BRINGING THE AXIS OF INSTABILITY CAN BUCK THE ZONAL FLOW AND GET
INTO THE SOUTHERN PART OF OUR CWA. BY THIS TIME PERIOD ITS LIKELY
SHOWING ITS HOT BIAS AND OUR MAX TEMPS ARE CLOSER TO GFS MOS. BTW
THE 00Z MEX MOS GUIDANCE WAS AMONG THE HOTTEST OF ITS ENSEMBLE
MEMBERS. FCST DEW POINTS KEEP AFTERNOON HEAT INDICES SHORT OF HEAT
HEADLINE CRITERIA IN URBAN AREAS.
NO BIG CHANGES TO WEEKEND THINKING WITH SUNDAY BEING THE MORE
LIKELIER DAY TO HAVE TSTMS AROUND. NEXT ATTEMPTED COLD FRONT SHOULD
STOP SHORT OF OUR CWA ON SATURDAY, BUT IMPULSES FROM IT SHOULD
TRIGGER AT LEAST SOME WIDELY SCATTERED TSTMS. A BETTER CHANCE ON
SUNDAY AS THE FRONT APPROACHES AND IN LIKELIHOOD A LEE SIDE TROF
FORMS. MAX TEMPS ARE KEPT AS STATUS QUO VS DROPPING THEM ON THE
WEEKEND BASED ON FCST 850MB AND 925MB TEMPS AND NOT COUNTING ON
EXCESS CLOUDINESS TO KEEP TEMPS DOWN. WITH HIGHER DEW POINTS, WE
MIGHT MAKE HEAT HEADLINE CRITERIA ON THE WEEKEND IN THE MORE
URBANIZED LOCALES AND WE WILL CONTINUE MENTION IN THE HWO.
NOT AS SURE FOR MONDAY,
THE FRONT IS EXPECTED TO TRUNDLE THROUGH OUR FORECAST AREA ON
MONDAY. THE MODEL TIMING IS NOT THAT DIFFERENT AND THE 00Z ECMWF
ENSEMBLE MEAN WAS CLOSE TO THE MODEL`S DETERMINISTIC SOLUTION. THUS
NOT AS CONFIDENT ABOUT THE 90S OR HEAT HEADLINES ON MONDAY AS THERE
SHOULD BE MORE CLOUDS AROUND AND HAVE PLACED HIEST POPS EAST BASED
ON THE ENSEMBLE FRONTAL POSN AT 12Z MON.
WHILE THIS FRONT MAY BE `STRONGER", ITS ONLY BECAUSE THE PREVIOUS
TWO WERE LEFT IN THE METEOROLOGICAL GUTTER. SO ON TUESDAY ITS BEST
IMPACT MAY BE TO LOWER DEW POINTS SOMEWHAT WITH NOT A BIG DROP IN
TEMPS FORECAST. WE WILL START TUESDAY AS A DRY DAY AND SEE WHAT
TOMORROW BRINGS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
NEAR TERM MODEL SUGGEST THAT THE SHOWERS COULD AFFECT THE KPHL
METRO AIRPORTS AND KILG THROUGH 0600 UTC. IT IS POSSIBLE THAT THE
KPHL METRO AIRPORTS COULD SEE A BRIEF PERIOD OF MVFR CONDITIONS
WITH THE SHRINKING AREA OF SHOWERS AND THUNDERSTORMS. THE TERMINAL
FORECASTS THERE WILL BE UPDATED AS THE AREA GETS CLOSER.
AFTER THIS...THE FORECAST SHOULD BE DRY. THE EAST SOUTHEAST FLOW
COULD RESULT IN A PERIOD OF MVFR CEILINGS AT KRDG...KABE AND KTTN.
FURTHER SOUTH AND EAST...THE CEILING FORECAST WAS MAINLY VFR...WITH
PATCHY FOG AT KMIV.
FOR WEDNESDAY...MAINLY VFR CONDITIONS ARE EXPECTED. AN ONGOING LINE
OF SHOWERS AND THUNDERSTORMS COULD BEGIN TO AFFECT KRDG AND KABE AS
EARLY AS 1400 UTC...AND THIS IS INCLUDED AS A VCSH REMARK AT THESE
LOCATIONS. ELSEWHERE...THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS
WAS PUSHED BACK UNTIL 1700 UTC...AND INDICATED WITH A PROB30 REMARK.
WHILE THUNDERSTORMS COULD PRODUCE LOCAL MVFR/IFR CONDITIONS...IT IS
STILL TO EARLY TO INCLUDE THIS IN THE FORECAST. THE THREAT FOR
SHOWERS AND THUNDERSTORMS SHOULD DIMINISH AFTER 0100 UTC THURSDAY.
OUTLOOK...
WEDNESDAY NIGHT...PRIMARILY VFR, EXCEPT LOCALLY IFR IN SCATTERED
HEAVY SHOWERS AND STRONG THUNDERSTORMS. ALSO LOCALLY MVFR TO IFR
IN FOG LATE WED NIGHT.
THURSDAY THROUGH FRIDAY NIGHT...VFR, ISOLATED MVFR CONDITIONS IN
EARLY MORNING FOG AND MORE ISOLATED (VS WEDNESDAY) SHOWERS AND
THUNDERSTORMS.
SATURDAY...PRIMARILY VFR. ISOLATED AFTN/EVENING TSTM. SOME
EARLY MORNING FOG OUTLYING AIRPORTS.
SUNDAY...PRIMARILY VFR. SCATTERED AFTN/EVENING TSTM SHOULD HAVE
MORE OF A MVFR AND OPERATIONAL IMPACT. SOME EARLY MORNING FOG
OUTLYING AIRPORTS.
&&
.MARINE...
THE FORECAST WAS UPDATED TO BEEF UP WINDS OVER THE DELAWARE BAY.
BOTH BRND1 AND SJSN4 ARE GUSTING TO NEAR 20 KNOTS. THE INCREASE IN
WIND SPEED APPEARS TO BE DUE TO THE WIND DIRECTION (FUNNELING ON
THE DAY) AND THE DIURNAL WIND MAXIMUM (WHICH SHOULD START TO BACK
OFF SOON). WINDS SHOULD DROP OFF FAIRLY QUICKLY LATER THIS EVENING.
A BRIEF LULL IS EXPECTED OVER THE FORECAST WATERS LATER TONIGHT
AS LOW PRESSURE OFF THE COAST MOVES NORTHEAST. A GENERAL EASTERLY
FLOW WILL SHIFT TO A MORE SOUTHERLY FLOW LATE TONIGHT AND CONTINUE
THROUGH WEDNESDAY. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A
ADVANCING FRONT WILL MOVE IN FROM THE WEST WEDNESDAY AFTERNOON AND
CONTINUE INTO WEDNESDAY NIGHT. SOME OF THESE THUNDERSTORMS COULD
PRODUCE LOCALLY HAZARDOUS MARINE CONDITIONS...BUT RIGHT NOW SUB-
SCA CONDITIONS ARE EXPECTED ON THE LARGE SCALE.
OUTLOOK...
AS PER PMDHMD AND OPC MIMATN DISCUSSION, WE ARE NOT GOING TO BE
FOLLOWING THE GFS SOLUTION. THUS WINDS AND SEAS WITH THE NEXT
OFFSHORE LOW ARE EXPECTED TO REMAIN BELOW SCA CRITERIA IN OUR
COASTAL WATERS UNTIL THE LOW PASSES TO OUR EAST AROUND THURSDAY.
BEYOND THAT, A GENERAL SOUTHERLY FLOW IS EXPECTED TO PERSIST INTO
SUNDAY. ITS POSSIBLE BY SUNDAY OR BEYOND DETERMINISTIC FORECAST
MONDAY, THE GRADIENT OR PERSISTENCE OF THE SOUTHERLY FLOW MIGHT BE
ENOUGH FOR SMALL CRAFT ADVISORY CRITERIA TO BE MET. IT MAY BE MORE
FOR SEAS THAN WINDS. REGARDLESS CONFIDENCE ABOUT REMAINING BELOW
SMALL CRAFT ADVISORY CRITERIA LOWERS AS THE WEEKEND PROGRESSES.
&&
.HYDROLOGY...
HEAVY DOWNPOURS ASSOCIATED WITH THUNDERSTORMS...ESPECIALLY WEDNESDAY
AFTERNOON...COULD PRODUCE RAPID RUNOFF IN SOME AREAS. THIS SCENARIO
BRINGS WITH IT THE THREAT OF HIGHLY LOCALIZED FLOODING...ESPECIALLY
IN URBAN SETTINGS. RIGHT NOW THIS THREAT DOESN`T APPEAR TO BE
WIDESPREAD ENOUGH TO WARRANT A FLASH FLOOD WATCH...BUT GIVEN THE
AMOUNT OF MOISTURE AVAILABLE IN THE ATMOSPHERE...CAN`T RULE OUT ONE
OR TWO ISOLATED PROBLEMS.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING ADVISORY FOR THE UPPER DELAWARE BAY WAS LOWERWS
AT 1230 AM.
ANOTHER ROUND OF MINOR TIDAL FLOODING MAY OCCUR WEDNESDAY EVENING
DUE TO A PERSISTENT SOUTHERLY FLOW AND FULL MOON.
&&
.RIP CURRENTS...
MODERATE RISK INTO WEDNESDAY WITH A CONTINUED 2-3 FT SWELL AND
HIGHER THAN NORMAL ASTRONOMICAL TIDES ASSOCIATED WITH THE UPCOMING
FULL MOON.
&&
.CLIMATE...
TOP FIVE WARMEST JULYS ON RECORD IN PARTS OF OUR AREA.
IN TERMS OF 90 DEGREE DAYS FOR THE MONTH OF JULY.
AT PHILADELPHIA 21 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
HIGHER OCCURRED THROUGH THE 29TH. THIS TIES THE RECORD FOR
THE MOST NUMBER OF 90 DEGREES DAYS ALL TIME WITH 1952, 1988, 1995
AND 2011.
AT ALLENTOWN 15 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR HIGHER
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1983, 2010 AND
2011. GREATEST IS 20 DAYS IN 1999, 1966 AND 1955.
AT WILMINGTON 17 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1952. GREATEST
IS 22 DAYS IN 1894.
AT ATLANTIC CITY 14 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
MORE OCCURRED THROUGH THE 29TH. THIS IS FIFTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 2010. GREATEST IS
21 DAYS IN 1983.
AT READING 19 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SECOND ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY. GREATEST IS 20 DAYS
SET IN 2011, 2010, 1999 AND 1955.
IN TERMS OF WARMEST AVERAGE TEMPERATURE RECORDED FOR THE MONTH OF
JULY.
AT PHILADELPHIA THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 30TH
WAS 81.9. WE ARE PROJECTING 81.7 FOR THE MONTH. THIS IS THE THE
THIRD WARMEST JULY ON RECORD BEHIND 2011 82.4 AND 1994 82.1 AND
EQUALING THE 81.7 IN 2010.
AT WILMINGTON THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 30TH
WAS 80.4. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2011 AND
1955.
AT ATLANTIC CITY THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 30TH
WAS 78.7. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2010
AND 2011.
AT ALLENTOWN THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 30TH
WAS 77.6 AND IS THE SEVENTH WARMEST JULY ON RECORD.
DATA SINCE 6/28 THROUGH 7/30...33 DAYS.
RDG ONLY 2 DAYS BELOW NORMAL
PHL/ABE/GED ONLY 3 DAYS BELOW NORMAL
TTN 5 DAYS BELOW NORMAL
MPO 5 DAYS BELOW NORMAL
ILG 6 DAYS BELOW NORMAL
ACY 10 DAYS BELOW NORMAL
90 OR HIGHER FOR THE SEASON
SO FAR TOTAL
NORMAL THIS YR LAST YR POR
ABE 17 24 21 1922
ACY 22 31
GED 29 40
ILG 27 27
PHL 21 30 33 1874
RDG 30 30
TTN 25 26
MPO 3 4
THE NORMAL AND PERIOD OF RECORD /POR/ IS LISTED FOR ONLY TWO CLIMATE
SITES WHERE THE DATASET IS EASILY AVAILABLE AND COMPLETE.
WITH RESPECT TO OCCURRENCES OF 95 OR GREATER PHL CLIMATOLOGICALLY
AVG`S 4/YR SO FAR THIS YR 12 LAST YRS TOTAL 11.
STATISTICALLY FOR PHL AS EVALUATED BY MARK DELISI...THE NUMBER OF 95
OR WARMER DAYS THIS YEAR IS UNUSUAL.
FOR OUR FORECAST AREA...
PCPN FOR THE MONTH SO FAR NOW GENERALLY WITHIN 75 PCT OF NORMAL.
TEMP FOR THE MONTH SO FAR NOW GENERALLY 2.5 TO 5F ABOVE NORMAL.
&&
.EQUIPMENT...
KDOX RADAR IS EXPECTED TO BE OFFLINE FOR SEVERAL DAYS DUE TO A
PEDESTAL DYNAMIC FAULT. TECHNICIANS ARE WORKING ON THE PROBLEM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI
NEAR TERM...MIKETTA
SHORT TERM...MIKETTA
LONG TERM...GIGI
AVIATION...DRAG/GIGI/HAYES
MARINE...GIGI/HAYES/MIKETTA
HYDROLOGY...
TIDES/COASTAL FLOODING...
RIP CURRENTS...
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
935 PM MDT THU AUG 2 2012
.UPDATE...
ISSUED AT 930 PM MDT THU AUG 2 2012
UPDATED THE FORECAST BASED ON THE LATEST RADAR TRENDS. THE LINE OF
SHOWERS AND THUNDERSTORMS MOVING INTO THE AREA NOW ARE EXPECTED TO
PERSIST UNTIL AROUND MIDNIGHT BEFORE DISSIPATING AS THEY MOVE INTO
THE DRIER AIR ROUGHLY EAST OF A MCCOOK TO GOVE LINE. DURING THE
LATE EVENING A STRONGER UPPER LEVEL SHORT WAVE TROUGH WILL MOVE
OVER THE WESTERN PART OF THE AREA. HOWEVER SOUNDINGS SHOW THE
ENVIRONMENT DRYING OUT UP TO 500MB AHEAD OF THE TROUGH...SO AM NOT
EXPECTING ANY STORM DEVELOPMENT BEHIND THE CURRENT LINE OF STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 219 PM MDT THU AUG 2 2012
THROUGH TONIGHT...CU FIELD CONTINUES TO DEVELOP AND EXPAND ACROSS
THE SOUTHWEST PORTION OF THE FORECAST AREA THIS AFTERNOON. FEEL THIS
WILL BE A FAVORED LOCATION FOR THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS OVER THE NEXT FEW HOURS SO HAVE ADDED IN A MENTION OF
ISOLATED CONVECTION. ADDITIONAL CONVECTION IS BEGINNING TO INITIATE
ALONG THE FRONT RANGE. SIMILAR TO THE PAST FEW DAYS...CONVECTION
WILL GRADUALLY SHIFT EASTWARD TOWARD NORTHWEST KANSAS AND SOUTHWEST
NEBRASKA. HAVE UPPED POPS TO LIKELY OVER EASTERN COLORADO AFTER 00Z
WITH A GRADUAL DECREASE BACK TO SLIGHT CHANCE/CHANCE AS THE COMPLEX
BEGINS TO DIMINISH ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA BY
AROUND 06Z. EXPECT A GRADUALLY CLEARING SKY FOR THE REMAINDER OF THE
NIGHT WITH LIGHT WINDS.
FRIDAY...WILL SEE ANOTHER DAY OF TEMPS IN THE UPPER 90S TO AROUND
100 DEGREES. SOUTHERLY/SOUTHWESTERLY WINDS WILL DEVELOP AHEAD OF
A LEAD SURFACE TROUGH WHICH WILL APPROACH THE AREA BY LATE AFTERNOON
AIDING IN THE DEVELOPMENT OF ISOLATED TO SCATTERED CONVECTION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 219 PM MDT THU AUG 2 2012
FRIDAY NIGHT-SUNDAY...WITH STRONG SHORT WAVE MOVING INTO THE
NORTHERN PLAINS AT THE START OF THE PERIOD...THE TIMING OF
ASSOCIATED COLD FRONT WILL BE THE MAIN FOCUS OF THE PERIOD. GENERAL
CONSENSUS OF OPERATIONAL MODELS BRINGS FRONT THROUGH THE AREA IN THE
6 TO 12Z SAT TIME PERIOD WITH PREVIOUS RUNS OF SREF AND GEFS SHOWING
SIMILAR TRENDS. HAVE SOME CONCERNS THAT Q VECTORS INDICATE A STRONG
NORTHERLY COMPONENT TO THE AGEOSTROPHIC WIND WHICH COULD SPEED UP
FROPA...BUT HARD TO IGNORE ALL THE AGREEMENT BETWEEN VARIOUS
SIMULATIONS. GIVEN THE TIMING OF THE COLD FRONT...THINK BEST
PRECIPITATION CHANCES WILL COME IN BASICALLY 2 PERIODS. THE FIRST
WILL LIKELY BE ALONG SFC TROUGH AHEAD OF FRONT DURING THE LATE
AFTERNOON AND EVENING SUGGESTING STORMS WILL INITIATE NEAR THE KS-CO
BORDER AND DRIFT EAST IN THE EVENING. BETTER CHANCES SHOULD OCCUR IN
THE 9 TO 15Z TIME FRAME ON SATURDAY AS DEEP FRONTAL CIRCULATION
EXPECTED TO DEVELOP BEHIND COLD FRONT...CO-LOCATED IN AREA OF LARGE
SCALE ASCENT AND WEAKLY CAPPED ELEVATED INSTABILITY. WHILE RAIN
CHANCES WILL BE BETTER OVERNIGHT...OVERALL INSTABILITY LIMITED AND
THINK ANY PRECIPITATION THAT FALLS WILL BE MUCH LIGHTER THAN IN THE
EARLY EVENING. AS FRONT CONTINUES TO DIVE TO THE SOUTH AND SHORT
WAVE TROUGH CONTINUES ACROSS THE DAKOTAS FORCING WILL GRADUALLY
DIMINISH AND MID LEVEL CINH INCREASE THROUGH THE LATE MORNING HOURS
BRINGING AN END TO PRECIPITATION CHANCES. WITH A COOLER...RELATIVELY
STABLE AIR MASS BUILDING OVER THE AREA THINK PRECIP CHANCES WILL END
FAIRLY QUICKLY AND REMAIN LOW THROUGH SUNDAY.
IN THE EXTENDED (SUNDAY NIGHT-THURSDAY)...MEDIUM RANGE MODELS HAVE
COME INTO A LITTLE BETTER AGREEMENT WITH DEVELOPMENT OF RIDGE
THROUGH THE MIDDLE OF NEXT WEEK WITH GFS ENSEMBLES AND ECMWF COMING
INTO A BIT BETTER AGREEMENT WITH THE MORE AMPLIFIED RIDGE OF THE
GFS. GIVEN RIDGE AXIS WILL BE TO THE WEST OF THE AREA...THINK THERE
WILL BE AT LEAST A SMALL THREAT FOR STORMS AS WEAK DISTURBANCES MOVE
AROUND PERIPHERY OF LARGE SCALE RIDGE. CONSENSUS PRODUCTS SEEM TO BE
SHOWING A LOT OF RUN TO RUN VARIABILITY WITH THE HIGHER POP VALUES
THOUGH...SO DO NOT THINK GOING MORE THAN ISOLATED DURING ANY PERIOD
IS WARRANTED. TEMPS WILL WARM BACK INTO THE UPPER 90S LOW 100S
THROUGH THE WEEK. CONSIDERED GOING A BIT WARMER...ESPECIALLY IN
EAST BUT WITH POTENTIAL FOR OVERNIGHT MCS ACTIVITY AM A LITTLE
CONCERNED ABOUT OUTFLOW HOLDING TEMPS BACK A BIT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 518 PM MDT THU AUG 2 2012
VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. LATEST RADAR TRENDS
INDICATE SHOWERS AND THUNDERSTORMS ARE REMAINING TO THE NORTH AND
SOUTH OF KGLD AS THEY MOVE EASTWARD. WITH THE COOL OUTFLOW FROM
THE STORMS BEING PUSHED WELL INTO KIT CARSON COUNTY...AM NOT
ANTICIPATING ANY STORMS MOVING OVER KGLD FOR A COUPLE HOURS BEFORE
ANOTHER ROUND OF STORMS MOVE IN. DIFFICULT TO REALLY PINPOINT A
TIME FRAME FOR STORMS FOR KGLD. GOING OFF OF LATEST FORECAST AS
WELL AS THE HRRR AND TRENDS FROM THE LAST FEW NIGHTS...STORMS
SHOULD MOVE NEAR/OVER KGLD DURING THE EARLY EVENING. A STRONGER
UPPER LEVEL SHORT WAVE TROUGH MOVES OVER KGLD DURING THE OVERNIGHT
HOURS. HOWEVER SOUNDINGS SHOW THE ENVIRONMENT AHEAD OF THE TROUGH
DRYING OUT...SO AM NOT ANTICIPATING ANYTHING MORE THAN A CLOUD
COVER WITH THE TROUGH PASSAGE. OTHERWISE GUSTY OUTFLOW WINDS FROM
THE THUNDERSTORMS TO THE SOUTHEAST SHOULD DIMINISH WITHIN THE NEXT
COUPLE OF HOURS IF NOT SOONER.
FOR KMCK AM NOT ANTICIPATING THE STORM ACTIVITY TO MAKE IT THAT
FAR EAST DUE TO THE DRIER ENVIRONMENT. HOWEVER WILL MONITOR
IN CASE ANY OUTFLOW BOUNDARIES TONIGHT DO SPARK STORMS NEAR KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
844 PM CDT THU AUG 2 2012
.UPDATE...
TRENDED DOWN POPS A LITTLE BETWEEN NOW AND 6Z GIVEN RECENT RADAR
AND SATELLITE TRENDS FOR AT LEAST THE CENTRAL PART OF THE CWA.
BOUNDARY IS STILL LOCATED IN NORTHERN OKLAHOMA WITH SOME CU AND
WIDELY SCATTERED STORMS DEVELOPING. THE BOUNDARY IS STILL PROGGED
TO SLOWLY MOVE NORTH INTO SOUTHERN KANSAS THROUGHOUT TONIGHT.
MOISTURE ADVECTION ISN`T VERY DESIRABLE AND A SIGNIFICANT SOURCE
OF LIFT IS LACKING...BUT STILL CANNOT RULE OUT SOME HIT OR MISS
ELEVATED SHOWERS ON THIS BOUNDARY DURING THE OVERNIGHT HOURS.
&&
ARL
.PREV DISCUSSION... /ISSUED 647 PM CDT THU AUG 2 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MONSOONAL MOISTURE CONTINUES TO RIDE UP AND OVER THE RIDGE
CENTERED OVER EASTERN NEW MEXICO AT THIS TIME. WIDELY SCATTERED
STORMS ARE UNDERWAY OVER THE HIGH PLAINS AND ARE VERY SLOWLY
DRIFING EAST. LATEST GUIDANCE KICKS OFF MORE CONVECTION ALONG LAST
NIGHT`S OUTFLOW BOUNDARY/850MB BAROCLINIC ZONE...BUT KEEPS IT
SOUTH OF THE OKLAHOMA BORDER FOR THE MOST PART. THIS IS CONFIRMED
BY A LITTLE CU DEVELOPMENT OVER NORTHERN OKLAHOMA RIGHT NOW.
ALSO...LATEST HRRR TENDS TO FIZZLE OUT THE CURRENT CONVECTION OVER
WESTERN KANSAS...BUT BRINGS IN ANOTHER ROUND OVERNIGHT AROUND
9-12Z. CONFIDENCE IS STILL LOW...BUT A HINT OF A MID LEVEL WAVE
ON WATER VAPOR MEANS SOME UPPER SUPPORT MAY ACCOMPANY THIS
DEVELOPMENT...AND DECIDED TO ADD SOME VCSH TO RSL AND SLN FOR JUST
A FEW PREDAWN HOURS. WILL CONTINUE TO MONITOR ONGOING CONVECTION
TO OUR WEST AND DEVELOPMENT TO OUR SOUTH...AND WILL LOOK AT 00Z
MODEL RUNS TO DETERMINE CHANCES FOR PRECIPITATION AT THE OTHER
SITES OVERNIGHT. IN THE MEAN TIME VFR CONDITIONS WILL DOMINATE.
ARL
PREV DISCUSSION... /ISSUED 332 PM CDT THU AUG 2 2012/
DISCUSSION...
TONIGHT...LIKE THE PAST FEW NIGHTS...CANNOT RULE OUT A FEW
THUNDERSTORMS AFTER MIDNIGHT ACROSS THE REGION...AS WEAK MONSOONAL
ENERGY TOPS STOUT UPPER RIDGE AND APPROACHES FROM THE WEST.
WONDERING IF BETTER CHANCES TONIGHT WILL BE GENERALLY SOUTH OF
I-70...ALONG/NORTH OF 850-700MB BOUNDARY...AND ALSO WITHIN HIGHEST
PRECIPITABLE WATER AXIS. WIDESPREAD RELIEF APPEARS
UNLIKELY...ALTHOUGH A FEW LOCATIONS COULD PICK UP A QUARTER INCH OR
SO.
FRIDAY TEMPERATURES...WITH THE POTENTIAL FOR ANOTHER OUTFLOW
BOUNDARY FROM OVERNIGHT CONVECTION...TEMPERATURES WILL ONCE AGAIN BE
TRICKY. HOWEVER...DO THINK AT LEAST SOUTHERN KANSAS TEMPERATURES
WILL SOAR WELL INTO THE 100S...SO WENT AHEAD AND EXTENDED CURRENT
EXCESSIVE HEAT WARNING THROUGH FRIDAY GENERALLY SOUTH OF HIGHWAY 54.
DEPENDING ON HOW CONVECTION EVOLVES TONIGHT...NIGHT SHIFT MAY NEED
TO EXTEND THIS HEADLINE A TAD FURTHER NORTH.
FRIDAY-SATURDAY...A FEW SHOWERS/THUNDERSTORMS MAY LINGER OVER THE
AREA INTO THE FRIDAY MORNING HOURS. OTHERWISE...WITH BOUNDARY
REMAINING IN PLACE...CANNOT RULE OUT A STRAY LATE AFTERNOON/EVENING
THUNDERSTORM OVER FAR SOUTHERN KS. SOMEWHAT BETTER CHANCES MAY
ARRIVE LATE FRIDAY NIGHT OVER CENTRAL KS...AS A STRONG COLD FRONT
APPROACHES FROM THE NORTHWEST. THE BEST THUNDERSTORM CHANCES SHOULD
BE ALONG THE COLD FRONT SATURDAY AFTERNOON-NIGHT OVER MAINLY
SOUTHERN KANSAS. DESPITE MARGINAL INSTABILITY AND BEST UPPER FORCING
REMAINING NORTH OF THE REGION...THINKING FRONTAL FORCING WILL BE
ENOUGH FOR AT LEAST WIDELY SCATTERED STORMS. PROBABLY NOT A
WIDESPREAD HEAVY RAINFALL EVENT...BUT PROBABLY AT LEAST SOME MODEST
RELIEF. WIDESPREAD SEVERE WEATHER APPEARS UNLIKELY...ALTHOUGH
ISOLATED STRONG/SEVERE WILL BE POSSIBLE.
SUNDAY...MODEST TEMPERATURE RELIEF IN WAKE OF THE COLD FRONT
EXPECTED...WITH HIGHS IN THE 90S ALL AREAS.
MONDAY-THURSDAY...MEDIUM RANGE GUIDANCE AND ASSOCIATED GFS ENSEMBLES
SUGGEST UPPER RIDGE WILL RETROGRADE WEST A BIT FOR NEXT WEEK KEEPING
NORTHWEST FLOW ALOFT ACROSS THE REGION. CONSEQUENTLY...WHILE ABOVE
NORMAL TEMPERATURES ARE STILL ANTICIPATED...CONFIDENCE IS INCREASING
THAT NEXT WEEK WILL ONLY BE IN THE 90S TO MAYBE LOW 100S.
ADDITIONALLY...NORTHWEST FLOW ALOFT BODES WELL FOR PERIODIC
PRECIPITATION CHANCES...AS AFTERNOON WESTERN HIGH PLAINS
THUNDERSTORM ACTIVITY ROLLS SOUTHEAST ALONG EASTERN EDGE OF WARM
850-700MB THERMAL RIDGE DURING THE EVENING AND NIGHTTIME HOURS.
HOWEVER...LEFT FORECAST DRY FOR NOW TO WAIT FOR BETTER RUN-TO-RUN
CONSISTENCY.
KLEINSASSER
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH
CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR
ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS
AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR
TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT
INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER
AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO
LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE
CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN
TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 76 105 78 101 / 30 10 10 30
HUTCHINSON 74 103 76 97 / 30 10 20 30
NEWTON 74 103 77 97 / 30 10 10 30
ELDORADO 74 104 78 100 / 30 10 10 30
WINFIELD-KWLD 78 107 80 103 / 30 10 10 30
RUSSELL 73 102 73 91 / 30 10 30 30
GREAT BEND 73 102 74 93 / 30 10 30 30
SALINA 73 102 75 94 / 30 10 30 30
MCPHERSON 73 103 76 96 / 30 10 20 30
COFFEYVILLE 77 107 79 104 / 30 10 10 30
CHANUTE 74 103 79 101 / 30 10 10 30
IOLA 75 102 79 101 / 30 10 10 30
PARSONS-KPPF 75 105 79 103 / 30 10 10 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT FRIDAY FOR KSZ069-082-083-
091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
647 PM CDT THU AUG 2 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MONSOONAL MOISTURE CONTINUES TO RIDE UP AND OVER THE RIDGE
CENTERED OVER EASTERN NEW MEXICO AT THIS TIME. WIDELY SCATTERED
STORMS ARE UNDERWAY OVER THE HIGH PLAINS AND ARE VERY SLOWLY
DRIFING EAST. LATEST GUIDANCE KICKS OFF MORE CONVECTION ALONG LAST
NIGHT`S OUTFLOW BOUNDARY/850MB BAROCLINIC ZONE...BUT KEEPS IT
SOUTH OF THE OKLAHOMA BORDER FOR THE MOST PART. THIS IS CONFIRMED
BY A LITTLE CU DEVELOPMENT OVER NORTHERN OKLAHOMA RIGHT NOW.
ALSO...LATEST HRRR TENDS TO FIZZLE OUT THE CURRENT CONVECTION OVER
WESTERN KANSAS...BUT BRINGS IN ANOTHER ROUND OVERNIGHT AROUND
9-12Z. CONFIDENCE IS STILL LOW...BUT A HINT OF A MID LEVEL WAVE
ON WATER VAPOR MEANS SOME UPPER SUPPORT MAY ACCOMPANY THIS
DEVELOPMENT...AND DECIDED TO ADD SOME VCSH TO RSL AND SLN FOR JUST
A FEW PREDAWN HOURS. WILL CONTINUE TO MONITOR ONGOING CONVECTION
TO OUR WEST AND DEVELOPMENT TO OUR SOUTH...AND WILL LOOK AT 00Z
MODEL RUNS TO DETERMINE CHANCES FOR PRECIPITATION AT THE OTHER
SITES OVERNIGHT. IN THE MEAN TIME VFR CONDITIONS WILL DOMINATE.
&&
ARL
.PREV DISCUSSION... /ISSUED 332 PM CDT THU AUG 2 2012/
DISCUSSION...
TONIGHT...LIKE THE PAST FEW NIGHTS...CANNOT RULE OUT A FEW
THUNDERSTORMS AFTER MIDNIGHT ACROSS THE REGION...AS WEAK MONSOONAL
ENERGY TOPS STOUT UPPER RIDGE AND APPROACHES FROM THE WEST.
WONDERING IF BETTER CHANCES TONIGHT WILL BE GENERALLY SOUTH OF
I-70...ALONG/NORTH OF 850-700MB BOUNDARY...AND ALSO WITHIN HIGHEST
PRECIPITABLE WATER AXIS. WIDESPREAD RELIEF APPEARS
UNLIKELY...ALTHOUGH A FEW LOCATIONS COULD PICK UP A QUARTER INCH OR
SO.
FRIDAY TEMPERATURES...WITH THE POTENTIAL FOR ANOTHER OUTFLOW
BOUNDARY FROM OVERNIGHT CONVECTION...TEMPERATURES WILL ONCE AGAIN BE
TRICKY. HOWEVER...DO THINK AT LEAST SOUTHERN KANSAS TEMPERATURES
WILL SOAR WELL INTO THE 100S...SO WENT AHEAD AND EXTENDED CURRENT
EXCESSIVE HEAT WARNING THROUGH FRIDAY GENERALLY SOUTH OF HIGHWAY 54.
DEPENDING ON HOW CONVECTION EVOLVES TONIGHT...NIGHT SHIFT MAY NEED
TO EXTEND THIS HEADLINE A TAD FURTHER NORTH.
FRIDAY-SATURDAY...A FEW SHOWERS/THUNDERSTORMS MAY LINGER OVER THE
AREA INTO THE FRIDAY MORNING HOURS. OTHERWISE...WITH BOUNDARY
REMAINING IN PLACE...CANNOT RULE OUT A STRAY LATE AFTERNOON/EVENING
THUNDERSTORM OVER FAR SOUTHERN KS. SOMEWHAT BETTER CHANCES MAY
ARRIVE LATE FRIDAY NIGHT OVER CENTRAL KS...AS A STRONG COLD FRONT
APPROACHES FROM THE NORTHWEST. THE BEST THUNDERSTORM CHANCES SHOULD
BE ALONG THE COLD FRONT SATURDAY AFTERNOON-NIGHT OVER MAINLY
SOUTHERN KANSAS. DESPITE MARGINAL INSTABILITY AND BEST UPPER FORCING
REMAINING NORTH OF THE REGION...THINKING FRONTAL FORCING WILL BE
ENOUGH FOR AT LEAST WIDELY SCATTERED STORMS. PROBABLY NOT A
WIDESPREAD HEAVY RAINFALL EVENT...BUT PROBABLY AT LEAST SOME MODEST
RELIEF. WIDESPREAD SEVERE WEATHER APPEARS UNLIKELY...ALTHOUGH
ISOLATED STRONG/SEVERE WILL BE POSSIBLE.
SUNDAY...MODEST TEMPERATURE RELIEF IN WAKE OF THE COLD FRONT
EXPECTED...WITH HIGHS IN THE 90S ALL AREAS.
MONDAY-THURSDAY...MEDIUM RANGE GUIDANCE AND ASSOCIATED GFS ENSEMBLES
SUGGEST UPPER RIDGE WILL RETROGRADE WEST A BIT FOR NEXT WEEK KEEPING
NORTHWEST FLOW ALOFT ACROSS THE REGION. CONSEQUENTLY...WHILE ABOVE
NORMAL TEMPERATURES ARE STILL ANTICIPATED...CONFIDENCE IS INCREASING
THAT NEXT WEEK WILL ONLY BE IN THE 90S TO MAYBE LOW 100S.
ADDITIONALLY...NORTHWEST FLOW ALOFT BODES WELL FOR PERIODIC
PRECIPITATION CHANCES...AS AFTERNOON WESTERN HIGH PLAINS
THUNDERSTORM ACTIVITY ROLLS SOUTHEAST ALONG EASTERN EDGE OF WARM
850-700MB THERMAL RIDGE DURING THE EVENING AND NIGHTTIME HOURS.
HOWEVER...LEFT FORECAST DRY FOR NOW TO WAIT FOR BETTER RUN-TO-RUN
CONSISTENCY.
KLEINSASSER
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH
CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR
ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS
AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR
TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT
INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER
AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO
LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE
CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN
TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 76 105 78 101 / 30 10 10 30
HUTCHINSON 74 103 76 97 / 30 10 20 30
NEWTON 74 103 77 97 / 30 10 10 30
ELDORADO 74 104 78 100 / 30 10 10 30
WINFIELD-KWLD 78 107 80 103 / 30 10 10 30
RUSSELL 73 102 73 91 / 30 10 30 30
GREAT BEND 73 102 74 93 / 30 10 30 30
SALINA 73 102 75 94 / 30 10 30 30
MCPHERSON 73 103 76 96 / 30 10 20 30
COFFEYVILLE 77 107 79 104 / 30 10 10 30
CHANUTE 74 103 79 101 / 30 10 10 30
IOLA 75 102 79 101 / 30 10 10 30
PARSONS-KPPF 75 105 79 103 / 30 10 10 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT FRIDAY FOR KSZ069-082-083-
091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
530 PM MDT THU AUG 2 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 219 PM MDT THU AUG 2 2012
THROUGH TONIGHT...CU FIELD CONTINUES TO DEVELOP AND EXPAND ACROSS
THE SOUTHWEST PORTION OF THE FORECAST AREA THIS AFTERNOON. FEEL THIS
WILL BE A FAVORED LOCATION FOR THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS OVER THE NEXT FEW HOURS SO HAVE ADDED IN A MENTION OF
ISOLATED CONVECTION. ADDITIONAL CONVECTION IS BEGINNING TO INITIATE
ALONG THE FRONT RANGE. SIMILAR TO THE PAST FEW DAYS...CONVECTION
WILL GRADUALLY SHIFT EASTWARD TOWARD NORTHWEST KANSAS AND SOUTHWEST
NEBRASKA. HAVE UPPED POPS TO LIKELY OVER EASTERN COLORADO AFTER 00Z
WITH A GRADUAL DECREASE BACK TO SLIGHT CHANCE/CHANCE AS THE COMPLEX
BEGINS TO DIMINISH ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA BY
AROUND 06Z. EXPECT A GRADUALLY CLEARING SKY FOR THE REMAINDER OF THE
NIGHT WITH LIGHT WINDS.
FRIDAY...WILL SEE ANOTHER DAY OF TEMPS IN THE UPPER 90S TO AROUND
100 DEGREES. SOUTHERLY/SOUTHWESTERLY WINDS WILL DEVELOP AHEAD OF
A LEAD SURFACE TROUGH WHICH WILL APPROACH THE AREA BY LATE AFTERNOON
AIDING IN THE DEVELOPMENT OF ISOLATED TO SCATTERED CONVECTION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 219 PM MDT THU AUG 2 2012
FRIDAY NIGHT-SUNDAY...WITH STRONG SHORT WAVE MOVING INTO THE
NORTHERN PLAINS AT THE START OF THE PERIOD...THE TIMING OF
ASSOCIATED COLD FRONT WILL BE THE MAIN FOCUS OF THE PERIOD. GENERAL
CONSENSUS OF OPERATIONAL MODELS BRINGS FRONT THROUGH THE AREA IN THE
6 TO 12Z SAT TIME PERIOD WITH PREVIOUS RUNS OF SREF AND GEFS SHOWING
SIMILAR TRENDS. HAVE SOME CONCERNS THAT Q VECTORS INDICATE A STRONG
NORTHERLY COMPONENT TO THE AGEOSTROPHIC WIND WHICH COULD SPEED UP
FROPA...BUT HARD TO IGNORE ALL THE AGREEMENT BETWEEN VARIOUS
SIMULATIONS. GIVEN THE TIMING OF THE COLD FRONT...THINK BEST
PRECIPITATION CHANCES WILL COME IN BASICALLY 2 PERIODS. THE FIRST
WILL LIKELY BE ALONG SFC TROUGH AHEAD OF FRONT DURING THE LATE
AFTERNOON AND EVENING SUGGESTING STORMS WILL INITIATE NEAR THE KS-CO
BORDER AND DRIFT EAST IN THE EVENING. BETTER CHANCES SHOULD OCCUR IN
THE 9 TO 15Z TIME FRAME ON SATURDAY AS DEEP FRONTAL CIRCULATION
EXPECTED TO DEVELOP BEHIND COLD FRONT...CO-LOCATED IN AREA OF LARGE
SCALE ASCENT AND WEAKLY CAPPED ELEVATED INSTABILITY. WHILE RAIN
CHANCES WILL BE BETTER OVERNIGHT...OVERALL INSTABILITY LIMITED AND
THINK ANY PRECIPITATION THAT FALLS WILL BE MUCH LIGHTER THAN IN THE
EARLY EVENING. AS FRONT CONTINUES TO DIVE TO THE SOUTH AND SHORT
WAVE TROUGH CONTINUES ACROSS THE DAKOTAS FORCING WILL GRADUALLY
DIMINISH AND MID LEVEL CINH INCREASE THROUGH THE LATE MORNING HOURS
BRINGING AN END TO PRECIPITATION CHANCES. WITH A COOLER...RELATIVELY
STABLE AIR MASS BUILDING OVER THE AREA THINK PRECIP CHANCES WILL END
FAIRLY QUICKLY AND REMAIN LOW THROUGH SUNDAY.
IN THE EXTENDED (SUNDAY NIGHT-THURSDAY)...MEDIUM RANGE MODELS HAVE
COME INTO A LITTLE BETTER AGREEMENT WITH DEVELOPMENT OF RIDGE
THROUGH THE MIDDLE OF NEXT WEEK WITH GFS ENSEMBLES AND ECMWF COMING
INTO A BIT BETTER AGREEMENT WITH THE MORE AMPLIFIED RIDGE OF THE
GFS. GIVEN RIDGE AXIS WILL BE TO THE WEST OF THE AREA...THINK THERE
WILL BE AT LEAST A SMALL THREAT FOR STORMS AS WEAK DISTURBANCES MOVE
AROUND PERIPHERY OF LARGE SCALE RIDGE. CONSENSUS PRODUCTS SEEM TO BE
SHOWING A LOT OF RUN TO RUN VARIABILITY WITH THE HIGHER POP VALUES
THOUGH...SO DO NOT THINK GOING MORE THAN ISOLATED DURING ANY PERIOD
IS WARRANTED. TEMPS WILL WARM BACK INTO THE UPPER 90S LOW 100S
THROUGH THE WEEK. CONSIDERED GOING A BIT WARMER...ESPECIALLY IN
EAST BUT WITH POTENTIAL FOR OVERNIGHT MCS ACTIVITY AM A LITTLE
CONCERNED ABOUT OUTFLOW HOLDING TEMPS BACK A BIT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 518 PM MDT THU AUG 2 2012
VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. LATEST RADAR TRENDS
INDICATE SHOWERS AND THUNDERSTORMS ARE REMAINING TO THE NORTH AND
SOUTH OF KGLD AS THEY MOVE EASTWARD. WITH THE COOL OUTFLOW FROM
THE STORMS BEING PUSHED WELL INTO KIT CARSON COUNTY...AM NOT
ANTICIPATING ANY STORMS MOVING OVER KGLD FOR A COUPLE HOURS BEFORE
ANOTHER ROUND OF STORMS MOVE IN. DIFFICULT TO REALLY PINPOINT A
TIME FRAME FOR STORMS FOR KGLD. GOING OFF OF LATEST FORECAST AS
WELL AS THE HRRR AND TRENDS FROM THE LAST FEW NIGHTS...STORMS
SHOULD MOVE NEAR/OVER KGLD DURING THE EARLY EVENING. A STRONGER
UPPER LEVEL SHORT WAVE TROUGH MOVES OVER KGLD DURING THE OVERNIGHT
HOURS. HOWEVER SOUNDINGS SHOW THE ENVIRONMENT AHEAD OF THE TROUGH
DRYING OUT...SO AM NOT ANTICIPATING ANYTHING MORE THAN A CLOUD
COVER WITH THE TROUGH PASSAGE. OTHERWISE GUSTY OUTFLOW WINDS FROM
THE THUNDERSTORMS TO THE SOUTHEAST SHOULD DIMINISH WITHIN THE NEXT
COUPLE OF HOURS IF NOT SOONER.
FOR KMCK AM NOT ANTICIPATING THE STORM ACTIVITY TO MAKE IT THAT
FAR EAST DUE TO THE DRIER ENVIRONMENT. HOWEVER WILL MONITOR
IN CASE ANY OUTFLOW BOUNDARIES TONIGHT DO SPARK STORMS NEAR KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 PM MDT WED AUG 1 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED AUG 1 2012
THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP
ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT
EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS
NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS
AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID
THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID
BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN
CONFIDENCE IS HIGHEST.
TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED
THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY
CLEARING SKY ARE EXPECTED.
THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY
WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100
DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING
DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND
135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A
THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON
POINT SOUNDINGS FROM ACROSS THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 225 PM MDT WED AUG 1 2012
THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE
THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE
NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA
FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO
THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION
CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE
SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY
WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST
NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM
VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS
ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS
AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK
OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST
CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON
FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT
ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER
ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT
COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS.
WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST
SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO
HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS
EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC
OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50
PERCENT WARRANTED ATTM.
IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES
SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE
UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO
DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME
ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS
WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS
CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME
BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE
TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE
PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A
FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA
KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR
LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND
STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH
DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH
VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK
PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR
MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING
NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT
DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA
BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT
TUES INTO WED MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1203 PM MDT WED AUG 1 2012
ANTICIPATE PRIMARILY VFR CONDITIONS OVER THE NEXT 24 HOURS AT BOTH
KGLD AND KMCK. CONVECTION SHOULD DEVELOP ACROSS THE HIGHER TERRAIN
OF EASTERN COLORADO LATE THIS AFTERNOON. QUESTIONS REMAIN AS TO
JUST HOW FAR EAST THIS PRECIP WILL MAKE IT. MAY SEE A FEW STORMS
DEVELOP ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA AFTER 22Z
BUT THESE SHOULD REMAIN AWAY FROM THE TERMINALS. WILL CARRY VCTS
FOR KGLD AFTER 03Z WITH VCSH FOR KMCK AFTER 04Z. CAN`T COMPLETELY
RULE OUT A BRIEF PERIOD OF MVFR VSBY SHOULD A HEAVIER STORM
DIRECTLY IMPACT A TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1249 AM MDT WED AUG 1 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 226 PM MDT TUE JUL 31 2012
15Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED LARGE
ANTICYCLONIC CIRCULATION ALOFT IN PLACE ACROSS THE SOUTHERN PLAINS
WITH CWA ON NORTHERN PERIPHERY OF CIRCULATION...WITH ANOTHER SHORT
WAVE TROUGH NOTED UPSTREAM ALONG THE UTAH AND COLORADO BORDER. 12Z
RAOBS INDICATED LITTLE CHANGE OVER THE PAST 24 HOURS ASIDE FROM SOME
LOW LEVEL DRYING AT LBF...WITH STEEP LAPSE RATES STILL OBSERVED
MAINLY BETWEEN H7 AND H6 AT BOTH DDC AND DNR.
MAIN SHORT TERM ISSUE WILL BE PRECIPITATION CHANCES LATE THIS
AFTERNOON AND EVENING.
TONIGHT...OVERALL PATTERN HAS CHANGED LITTLE FROM YESTERDAY WITH
LARGE SCALE RIDGE REMAINING TO THE SOUTH OF THE AREA AND SHORT WAVE
TROUGH MOVING OVER THE TOP OF THE RIDGE TONIGHT. OVERALL INSTABILITY
AND PW PROFILES SIMILAR AS WELL...WITH ONLY LOW LEVEL SHEAR BEING
NOTICEABLY WEAKER THAN YESTERDAY. WITH CU FIELDS DEVELOPING OVER THE
HIGHER TERRAIN AND NEAR MESOLOW NOTED OVER YUMA COUNTY...FAIRLY
LARGE LCLS IN PLACE FAVORING STRONG COLD POOLS AND MCS VECTORS
FAVORING EASTWARD MOTION INTO STRONGER INSTABILITY ACROSS THE CWA
THINK CHANCES FOR ANOTHER ROUND OF PRECIPITATION FAIRLY GOOD
ACROSS MUCH OF THE CWA...BUT UNTIL SOME ECHOES BEGIN TO DEVELOP
DOWNSTREAM AM HESITANT TO GO MUCH ABOVE THE 40-50% RANGE FOR POPS
ATTM. BEST TIMING FOR PRECIP LOOKS TO BE IN THE 00-04Z RANGE...BUT
WITH LINGERING WAA THROUGH THE NIGHT THINK AT LEAST A FEW WEAK
SHOWERS WILL CONTINUE THROUGH THE EARLY MORNING HOURS.
TEMPERATURES SHOULD BE FAIRLY SIMILAR TO WHAT OCCURRED LAST NIGHT
WITH WET BULB TEMPS WITH THUNDERSTORMS LIKELY BRINGING TEMPS DOWN
INTO THE 60S AS STORMS PASS RESULTING IN AT LEAST FEW LOCATIONS
SEEING LOW TEMPS OCCURRING EARLIER THAN NORMAL. WITH HIGH
PRECIPITABLE WATERS AND DEEP WARM CLOUD LAYER/FREEZING LEVEL
AROUND 17 KFT MSL...HEAVY RAIN WILL BE A THREAT BUT THINK OVERALL
MCS MOTION WILL BE FAST ENOUGH TO LIMIT ANY WIDESPREAD FLASH FLOOD
THREAT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1245 AM MDT WED AUG 1 2012
STRONG SYSTEM MOVING ACROSS THE NORTHERN PLAINS ON SATURDAY WILL
PUSH A SURFACE COLD FRONT WELL SOUTH OF THE FORECAST AREA.
TEMPERATURES ON SATURDAY WILL BE NEAR NORMAL...BUT PRECIPITATION
CHANCES SHOULD STAY SOUTH NEAR THE FRONT. RIDGE WILL REBUILD LATE
IN THE WEEKEND AND EARLY NEXT WEEK WITH TEMPERATURES BACK TO ABOVE
NORMAL. PRECIPITATION CHANCES COULD RETURN AS EARLY AS TUESDAY
WITH THE RIDGE BREAKING DOWN AND SHORTWAVE TROUGHS MOVING OUT OF
COLORADO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM MDT TUE JUL 31 2012
REMAINING SHOWERS AND THUNDERSTORMS ACROSS THE REGION SHOULD BE
DISSIPATING THROUGH THE OVERNIGHT HOURS BEFORE THEY HAVE AN
OPPORTUNITY TO MOVE OVER THE TAF SITES. HAVE NOT INCLUDED ANY
SHOWERS IN THE TAFS UNTIL WEDNESDAY EVENING BETWEEN 00Z-06Z.
THERE IS A POSSIBILITY CONDITIONS WILL DETERIORATE BELOW VFR IF A
STRONGER STORM MOVES DIRECTLY OVER ONE OF THE OBSERVATION
SITES...OTHERWISE HAVE KEPT CONDITIONS VFR THROUGH THE PERIOD AT
BOTH KMCK AND KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...024
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1148 PM MDT TUE JUL 31 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 226 PM MDT TUE JUL 31 2012
15Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED LARGE
ANTICYCLONIC CIRCULATION ALOFT IN PLACE ACROSS THE SOUTHERN PLAINS
WITH CWA ON NORTHERN PERIPHERY OF CIRCULATION...WITH ANOTHER SHORT
WAVE TROUGH NOTED UPSTREAM ALONG THE UTAH AND COLORADO BORDER. 12Z
RAOBS INDICATED LITTLE CHANGE OVER THE PAST 24 HOURS ASIDE FROM SOME
LOW LEVEL DRYING AT LBF...WITH STEEP LAPSE RATES STILL OBSERVED
MAINLY BETWEEN H7 AND H6 AT BOTH DDC AND DNR.
MAIN SHORT TERM ISSUE WILL BE PRECIPITATION CHANCES LATE THIS
AFTERNOON AND EVENING.
TONIGHT...OVERALL PATTERN HAS CHANGED LITTLE FROM YESTERDAY WITH
LARGE SCALE RIDGE REMAINING TO THE SOUTH OF THE AREA AND SHORT WAVE
TROUGH MOVING OVER THE TOP OF THE RIDGE TONIGHT. OVERALL INSTABILITY
AND PW PROFILES SIMILAR AS WELL...WITH ONLY LOW LEVEL SHEAR BEING
NOTICEABLY WEAKER THAN YESTERDAY. WITH CU FIELDS DEVELOPING OVER THE
HIGHER TERRAIN AND NEAR MESOLOW NOTED OVER YUMA COUNTY...FAIRLY
LARGE LCLS IN PLACE FAVORING STRONG COLD POOLS AND MCS VECTORS
FAVORING EASTWARD MOTION INTO STRONGER INSTABILITY ACROSS THE CWA
THINK CHANCES FOR ANOTHER ROUND OF PRECIPITATION FAIRLY GOOD
ACROSS MUCH OF THE CWA...BUT UNTIL SOME ECHOES BEGIN TO DEVELOP
DOWNSTREAM AM HESITANT TO GO MUCH ABOVE THE 40-50% RANGE FOR POPS
ATTM. BEST TIMING FOR PRECIP LOOKS TO BE IN THE 00-04Z RANGE...BUT
WITH LINGERING WAA THROUGH THE NIGHT THINK AT LEAST A FEW WEAK
SHOWERS WILL CONTINUE THROUGH THE EARLY MORNING HOURS.
TEMPERATURES SHOULD BE FAIRLY SIMILAR TO WHAT OCCURRED LAST NIGHT
WITH WET BULB TEMPS WITH THUNDERSTORMS LIKELY BRINGING TEMPS DOWN
INTO THE 60S AS STORMS PASS RESULTING IN AT LEAST FEW LOCATIONS
SEEING LOW TEMPS OCCURRING EARLIER THAN NORMAL. WITH HIGH
PRECIPITABLE WATERS AND DEEP WARM CLOUD LAYER/FREEZING LEVEL
AROUND 17 KFT MSL...HEAVY RAIN WILL BE A THREAT BUT THINK OVERALL
MCS MOTION WILL BE FAST ENOUGH TO LIMIT ANY WIDESPREAD FLASH FLOOD
THREAT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 226 PM MDT TUE JUL 31 2012
H5 RIDGE WILL BEGIN TO FLATTEN WITH WESTERLY ZONAL FLOW
DEVELOPING OVER THE NORTHERN PLAINS. THIS WILL ALLOW FOR A SERIES OF
STRONGER SHORTWAVE TROUGHS TO MOVE THROUGH THE NORTHERN PLAINS...AND
ASSOCIATED COLD FRONTS TO DROP SOUTH TOWARDS THE CWA.
THE FIRST OF THESE FRONT WILL ARRIVE LATE WEDNESDAY EVENING.
INSTABILITY AND MOISTURE WILL REMAIN IN PLACE THROUGH THE DAY
WEDNESDAY...WITH INITIATION DURING THE AFTERNOON FOLLOWING SIMILAR
PATTERN AS THE LAST FEW NIGHTS IN THE WEST/NORTHWEST. ISOLATED
ACTIVITY SHOULD INCREASE IN COVERAGE DURING THE EVENING HOURS AS
THUNDERSTORMS BECOME MORE ORGANIZED UNDER WEAK FLOW. DIFFERENCE WILL
BE WITH LARGE SCALE ASSOCIATED WITH COLD FRONT IN THE EVENING
HOURS...WHICH COULD HELP WITH COVERAGE/STRENGTH OF THUNDERSTORMS.
SOUNDINGS APPEAR TO BE DRIER THAN THE LAST FEW DAYS...HOWEVER PWAT
VALUES OVER 1 INCH ARE STILL BEING ADVERTISED. DEPENDING ON THE
TIMING OF THE FRONT POSITION OF THE BEST THUNDERSTORM COVERAGE COULD
BE PUSHED TO THE SOUTH AND EAST QUICKER THAN CURRENTLY
ADVERTISED...SO I WAS NOT CONFIDENT ENOUGH TO GO HIGHER THAN 40 POPS
DURING THE EVENING.
WEAK SHORTWAVE TROUGHS WILL CONTINUE TO MOVE NORTH OF THE CWA ON
THURSDAY...HOWEVER WITH POST FRONTAL AIRMASS IN PLACE I HAVE
QUESTIONS TO HOW MUCH SURFACE BASE AND MIXED LAYER CAPE WILL
BE AROUND TO INITIATE THUNDERSTORMS. FOR NOW I HAVE KEPT POPS
LIMITED TO 20 RANGE THU/THU NIGHT. BETTER CHANCES RETURN FRIDAY
NIGHT WHEN A STRONGER TROUGH MOVES THROUGH THE NORTHERN PLAINS AND
ANOTHER COLD FRONT DROPS SOUTH ACROSS THE CWA. HAVE INCREASED POPS
TO CHANCE CATEGORY. GUIDANCE CONTINUES TO SHOW CHANCES LINGERING
THROUGH SATURDAY NIGHT AS ADDITIONAL WEAKER SHORTWAVES MOVE
THROUGH THE AREA ON NORTHERN EXTENT OF RIDGE. CONFIDENCE IS LOWER
ON THIS ACTIVITY...SO I LIMITED IT TO SLIGHT CHANCE.
TEMPERATURES ON WEDNESDAY AND THURSDAY SHOULD BE AROUND OR ABOVE
100F WITH GOOD WAA AHEAD OF APPROACHING COLD FRONTS. BEHIND THE
FRONT ON THURSDAY AFTERNOON TEMPS WILL BE IN THE MID TO UPPER
90S...WITH NEAR NORMAL TEMPERATURES ON SATURDAY IN THE UPPER 80S/LOW
90S. THE H5 RIDGE WILL BEGIN TO BUILD NORTH AGAIN AND STRENGTHEN
SUNDAY INTO EARLY NEXT WEEK AND BRING US BACK TO 100 DEGREE
TEMPERATURES AND A DRIER PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM MDT TUE JUL 31 2012
REMAINING SHOWERS AND THUNDERSTORMS ACROSS THE REGION SHOULD BE
DISSIPATING THROUGH THE OVERNIGHT HOURS BEFORE THEY HAVE AN
OPPORTUNITY TO MOVE OVER THE TAF SITES. HAVE NOT INCLUDED ANY
SHOWERS IN THE TAFS UNTIL WEDNESDAY EVENING BETWEEN 00Z-06Z.
THERE IS A POSSIBILITY CONDITIONS WILL DETERIORATE BELOW VFR IF A
STRONGER STORM MOVES DIRECTLY OVER ONE OF THE OBSERVATION
SITES...OTHERWISE HAVE KEPT CONDITIONS VFR THROUGH THE PERIOD AT
BOTH KMCK AND KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
922 PM EDT THU AUG 02 2012
.Forecast Update...
Issued at 921 PM EDT Thu Aug 2 2012
Significant update to the forecast this evening as convective
complex is making its way into southwest Indiana. Numerous
thunderstorms are expected west of I-65 this evening and into the
overnight as convection centered around an MCV over southern
Illinois also responds to an increase of a LLJ (20-25 knots). MCV
center will slide southeast toward the BWG region, however
convective bands east of the center will impact southwest Indiana
and west central Kentucky this evening. Surface analysis, shows a
weak low pressure over southern Illinois, with the instability
gradient extending from southern KY to the St. Louis region. Do
expect storms to weaken the further east they get toward I-65 and
out of the more favorable environment. West of I-65, a few strong or
even severe storms cannot be ruled out as PAH has already issued on
several storms. The main threats, however, will be frequent cloud to
ground lightning and heavy rainfall. The Storm Prediction Center has
issued a mesoscale discussion mentioning a 40 percent chance of a
severe thunderstorms watch over the western CWA over the next couple
of hours.
&&
.Short Term (Today through Friday)...
Issued at 310 AM EDT Thu Aug 2 2012
Another hot and sunny day today as high pressure dewpoints in the
upper 50s to lower 60s over the Ohio Valley limited cloud cover to
just a few vertically challenged cumulus over southern Kentucky.
Surface temperatures as of 3 pm EDT ranged from around 90 along I-75
to the upper 90s on the western edge of our forecast area.
The status quo will NOT be the forecast for the area over the next
36 hours. On the plus side, high temperatures Friday will drop 5-10
degrees from today as cloud cover associated with thunderstorms
moving east of the Mississippi after midnight will reduce insolation
during the day. On the down side, the relatively dry air of the
past few days will be just a memory by midday Friday as southerly
winds set up in advance of deepening low pressure from the southern
Plains to the upper Mississippi valley send 70+ dewpoints back north
of the Ohio River.
The aforementioned thunderstorms are currently developing along the
Mississippi from around Quincy, Illinois southeast to around Lake
Barkley. Despite the near proximity of the southern edge, however,
eastward progression of the precipitation will be limited,
especially in the northern part of the forecast area, as the
greatest upper level energy associated with this system is progged
to dive southward into Tennessee. There is actually some
disagreement on this progression among the forecast models, but our
office`s local WRF model, which pegged the similar track of storms
Tuesday night, shows the bulk of the precip staying southwest of the
Natcher Parkway overnight. These would then migrate eastward over
southern KY during the day Friday, with storms more scattered north
of the Western/Bluegrass Parkways. As the main short wave
supporting this races east on Friday, precip chances will wane but
the clouds and higher dewpoints will linger.
After overnight lows within a few degrees of 70 across the area, max
temperatures Friday will rebound to the upper 80s to lower 90s. By
Saturday morning, low temperatures will remain in the low to mid 70s
across the area.
.Long Term (Saturday through Wednesday night)...
Issued at 330 PM EDT Thu Aug 2 2012
Saturday afternoon is still looking good for diurnal convection to
fire up as the Ohio Valley remains in an unsettled pattern
through Sunday. Warm, moist air will be advecting into the region
under southerly flow and combined with decent instability,
thunderstorms could become strong and an isolated severe cell cannot
be entirely ruled out. There doesn`t appear to be much organization
or shear to anything that does develop so it will most likely be
pulse-like in nature and wain after sunset.
The main concern for this forecast period remains to be on Sunday as
the synoptic pattern comes together for the possibility of a more
organized severe weather event. The trough that will be affecting
the forecast area is already visible on water vapor imagery in
British Columbia, Canada. This deep low pressure system is
anticipated to mature and occlude between now and Sunday, traversing
the Great Lakes region over the weekend. Trailing from this low will
be a cold front that continues to look stout for this time of year.
Ensemble 850mb temperature anomalies are a bit more apparent on
today`s runs as compared to yesterday`s. Looking at the upper-air
pattern associated with this system is a jet that appears at 250mb
and 300mb, leaving the Ohio Valley close to the right entrance
region. Low to mid level moisture appears abundant since southerly
flow will already be advecting the moist, unstable air into the
area. PWATS exceeding the 2 inch mark as well as decent CAPE values
show up on model soundings. Mentionable 0-6km shear is also showing
up at around 30kts. Therefore, will need to continue to keep an eye
on how this all develops given that it is still a few days out and
exact details are yet to be determined.
The remainder of the forecast period could end up being generally
dry after the fropa late Sunday/early Monday and is reflected in the
grids. Some locations in the southeastern portions of the
forecast area could see some lingering precip associated with the
frontal boundary early Monday, depending on the speed of everything.
With regard to temperatures, highs on Saturday should linger near
the 90 degree mark but could change depending on cloud cover and
precip. The same uncertainty for temperatures is in store for Sunday
as the highs could very well occur early on in the day, depending on
the timing of the front but regardless of that, precip and clouds
should keep them in the upper 80s overall. Monday will most likely
be the coolest of this forecast period (in the mid to upper 80s) as
dry, northwest air flows in. Tuesday and Wednesday will rebound into
the 90s. Overnight lows throughout the entirety of this period will
range from the mid 60s to the low 70s with the warmest night looking
to happen Saturday into Sunday and the coolest night occurring
Monday into Tuesday.
&&
.Aviation (03/00Z TAF Issuance)...
Issued at 714 PM EDT Thu Aug 2 2012
VFR conditions are expected for much of the forecast period. Main
aviation concern is the eventual track of an MCV just east of the
St. Louis Metro area. Latest runs of the HRRR suggest that this
feature will head east and diminish in intensity with the loss of
heating this evening. LMK local WRF model suggests the same thing,
but redevelops another batch of convection over western KY later
tonight along left over convective boundaries. Dry conditions are
expected at the terminals through at least 03/06Z. However, KBWG
and KSDF could see some convection later tonight as the remnants of
the aforementioned MCV head east and/or southeast across the
region. Improving conditions are expected after 03/13-14Z with
isolated-scattered convection redeveloping again Friday
afternoon/evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......JBS
Long Term........LG
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
714 PM EDT THU AUG 02 2012
...Updated Aviation Discussion...
.Short Term (Today through Friday)...
Issued at 310 AM EDT Thu Aug 2 2012
Another hot and sunny day today as high pressure dewpoints in the
upper 50s to lower 60s over the Ohio Valley limited cloud cover to
just a few vertically challenged cumulus over southern Kentucky.
Surface temperatures as of 3 pm EDT ranged from around 90 along I-75
to the upper 90s on the western edge of our forecast area.
The status quo will NOT be the forecast for the area over the next
36 hours. On the plus side, high temperatures Friday will drop 5-10
degrees from today as cloud cover associated with thunderstorms
moving east of the Mississippi after midnight will reduce insolation
during the day. On the down side, the relatively dry air of the
past few days will be just a memory by midday Friday as southerly
winds set up in advance of deepening low pressure from the southern
Plains to the upper Mississippi valley send 70+ dewpoints back north
of the Ohio River.
The aforementioned thunderstorms are currently developing along the
Mississippi from around Quincy, Illinois southeast to around Lake
Barkley. Despite the near proximity of the southern edge, however,
eastward progression of the precipitation will be limited,
especially in the northern part of the forecast area, as the
greatest upper level energy associated with this system is progged
to dive southward into Tennessee. There is actually some
disagreement on this progression among the forecast models, but our
office`s local WRF model, which pegged the similar track of storms
Tuesday night, shows the bulk of the precip staying southwest of the
Natcher Parkway overnight. These would then migrate eastward over
southern KY during the day Friday, with storms more scattered north
of the Western/Bluegrass Parkways. As the main short wave
supporting this races east on Friday, precip chances will wane but
the clouds and higher dewpoints will linger.
After overnight lows within a few degrees of 70 across the area, max
temperatures Friday will rebound to the upper 80s to lower 90s. By
Saturday morning, low temperatures will remain in the low to mid 70s
across the area.
.Long Term (Saturday through Wednesday night)...
Issued at 330 PM EDT Thu Aug 2 2012
Saturday afternoon is still looking good for diurnal convection to
fire up as the Ohio Valley remains in an unsettled pattern
through Sunday. Warm, moist air will be advecting into the region
under southerly flow and combined with decent instability,
thunderstorms could become strong and an isolated severe cell cannot
be entirely ruled out. There doesn`t appear to be much organization
or shear to anything that does develop so it will most likely be
pulse-like in nature and wain after sunset.
The main concern for this forecast period remains to be on Sunday as
the synoptic pattern comes together for the possibility of a more
organized severe weather event. The trough that will be affecting
the forecast area is already visible on water vapor imagery in
British Columbia, Canada. This deep low pressure system is
anticipated to mature and occlude between now and Sunday, traversing
the Great Lakes region over the weekend. Trailing from this low will
be a cold front that continues to look stout for this time of year.
Ensemble 850mb temperature anomalies are a bit more apparent on
today`s runs as compared to yesterday`s. Looking at the upper-air
pattern associated with this system is a jet that appears at 250mb
and 300mb, leaving the Ohio Valley close to the right entrance
region. Low to mid level moisture appears abundant since southerly
flow will already be advecting the moist, unstable air into the
area. PWATS exceeding the 2 inch mark as well as decent CAPE values
show up on model soundings. Mentionable 0-6km shear is also showing
up at around 30kts. Therefore, will need to continue to keep an eye
on how this all develops given that it is still a few days out and
exact details are yet to be determined.
The remainder of the forecast period could end up being generally
dry after the fropa late Sunday/early Monday and is reflected in the
grids. Some locations in the southeastern portions of the
forecast area could see some lingering precip associated with the
frontal boundary early Monday, depending on the speed of everything.
With regard to temperatures, highs on Saturday should linger near
the 90 degree mark but could change depending on cloud cover and
precip. The same uncertainty for temperatures is in store for Sunday
as the highs could very well occur early on in the day, depending on
the timing of the front but regardless of that, precip and clouds
should keep them in the upper 80s overall. Monday will most likely
be the coolest of this forecast period (in the mid to upper 80s) as
dry, northwest air flows in. Tuesday and Wednesday will rebound into
the 90s. Overnight lows throughout the entirety of this period will
range from the mid 60s to the low 70s with the warmest night looking
to happen Saturday into Sunday and the coolest night occurring
Monday into Tuesday.
&&
.Aviation (03/00Z TAF Issuance)...
Issued at 714 PM EDT Thu Aug 2 2012
VFR conditions are expected for much of the forecast period. Main
aviation concern is the eventual track of an MCV just east of the
St. Louis Metro area. Latest runs of the HRRR suggest that this
feature will head east and diminish in intensity with the loss of
heating this evening. LMK local WRF model suggests the same thing,
but redevelops another batch of convection over western KY later
tonight along left over convective boundaries. Dry conditions are
expected at the terminals through at least 03/06Z. However, KBWG
and KSDF could see some convection later tonight as the remnants of
the aforementioned MCV head east and/or southeast across the
region. Improving conditions are expected after 03/13-14Z with
isolated-scattered convection redeveloping again Friday
afternoon/evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......JBS
Long Term........LG
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
151 PM EDT WED AUG 1 2012
.UPDATE...
ISSUED AT 150 PM EDT WED AUG 1 2012
FRESHENED UP THE TEMPERATURE AND DEW POINT TRENDS TO BETTER MATCH THE
CURRENT OBSERVATIONAL TRENDS. OTHERWISE...NO UPDATE IS PLANNED.
UPDATE ISSUED AT 1057 AM EDT WED AUG 1 2012
MORNING CONVECTION DIMINISHED BETWEEN 9 AND 10 AM...AS SCHEDULED.
TEMPERATURES CAME IN COOLER THIS MORNING COMPARED TO TUESDAY
MORNING...AND THIS HAS HAMPERED THE DIURNAL RISE SO FAR. HAVE LOWERED
THE HIGHS A TOUCH TO ACCOUNT FOR THIS TREND...BUT GENERALLY MOST
LOCATIONS WILL STILL SEE AROUND 90. A WEAK STATIONARY FRONT REMAINS
DRAPED FROM JUST SOUTH OF A LINE FROM KEVV...TO KSDF...TO KILN.
ANOTHER SHORT WAVE TROUGH...CURRENTLY MOVING SOUTHEAST ACROSS INDIANA
WILL ALSO MOVE INTO EASTERN KENTUCKY THIS AFTERNOON. GIVEN THESE TWO
FEATURES...HAVE GONE AHEAD AND INCLUDED SLIGHT CHANCE POPS FOR ALL.
THE HRRR HAS BEEN GENERATING SOME CONVECTION ACROSS MOST OF THE
AREA...ALTHOUGH THE 06 AND 12Z NAM RUNS HAVE REMAINED DRY. THE
FORECAST SOUNDINGS HAVE TRENDED A BIT WEAKER WITH THE CAP THIS
AFTERNOON...AND THERE IS PLENTY OF DRY AIR ALOFT...WITH MUCH LOWER
WET-BULB ZERO HEIGHTS TODAY. WILL HAVE TO WATCH FOR A FEW PULSERS
THAT CAN TAKE ADVANTAGE OF THIS ENVIRONMENT.
UPDATE ISSUED AT 750 AM EDT WED AUG 1 2012
UPDATED THE GRIDS...MINORLY...TO BETTER REFLECT POPS EARLY THIS
MORNING. ALSO TWEAKED SKY...T AND TD GRIDS FOR CURRENT OBS AND
TRENDS. UPDATES HAVE BEEN SENT TO NDFD AND THE WEB.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT WED AUG 1 2012
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE LAYING ACROSS THE
NORTHWEST PORTION OF EASTERN KENTUCKY...RELATED TO A MINOR COLD FRONT
THAT IS PASSING THROUGH THE AREA EARLY THIS MORNING. THIS HAS JUST
RECENTLY HELPED TO TRIGGER A FEW CELLS OF CONVECTION IN THE WESTERN
PARTS OF THE CUMBERLAND VALLEY...DRIFTING SOUTHEAST INTO THE
SOUTHERN INTERSTATE 75 CORRIDOR. ON SATELLITE...THE CLOUDS HAVE
INCREASED DURING THE PAST COUPLE OF HOURS IN RESPONSE TO THE
BOUNDARY AND SOME ENERGY PASSING THROUGH AT MID LEVELS. THE CLOUDS
WILL HELP TO LIMIT ANY FURTHER DROP IN TEMPERATURES THROUGH THE REST
OF THE NIGHT. AS IT STANDS...A MINOR RIDGE TO VALLEY TEMPERATURE
SPLIT ON THE ORDER OF ABOUT 5 DEGREES EXISTS OUT THERE...MAINLY IN
THE NORTHEAST AS OF 3 AM EDT. LOW DEW POINT DEPRESSIONS ARE ALSO
FOUND IN THE VALLEYS AND ANY PLACE THAT MANAGE TO STAY MOSTLY CLEAR
CAN EXPECT PATCHY FOG IN THE VALLEYS TOWARD DAWN...POSSIBLY DENSE IN
LOCATIONS CLOSER TO THE VIRGINIA BORDER THAT SAW SOME DECENT RAINS ON
TUESDAY AFTERNOON.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT WITH THE MAIN FEATURES
AFFECTING THE SHORT TERM FORECAST. THEY AGREE THAT STRONG RIDGING
WILL REMAIN PARKED OFF TO THE SOUTHWEST OF THE AREA...IN NORTHERN
TEXAS...AND THAT THE EASTERN THIRD OF THE NATION WILL BE IN BROAD
TROUGHING...DOWNSTREAM OF THE RIDGE. LOCALLY...EAST KENTUCKY WILL BE
UNDER THE INFLUENCE OF NORTHWEST FLOW WITH A COUPLE OF WEAK
SHORTWAVES PASSING OVERHEAD INTO THURSDAY. ONE OF THESE WAVES IS
PASSING THIS MORNING AND IS PARTIALLY RESPONSIBLE FOR THE CURRENT
CONVECTION IMPACTING OUR WESTERNMOST COUNTIES. THE NEXT WILL COME
THROUGH THIS EVENING AND SHOULD BRING AN UPTICK IN CONVECTIVE
POTENTIAL TO THE AREA...THOUGH ITS BEST INFLUENCE WILL LIKELY BE FELT
FURTHER TO THE EAST. TOWARD THE END OF THE PERIOD...THE PATTERN
BECOMES MORE ZONAL AS THE EASTERN TROUGH STARTS TO FLATTEN OUT AND
THE WESTERN RIDGE SHIFTS SOUTH. GIVEN THE MODEL SIMILARITIES HAVE
FOLLOWED A BLENDED SOLUTION WITH A STRONG LEAN TOWARD THE HIGHER
RESOLUTION NAM12 OUTSIDE OF THE NEXT 12 HOURS...WHEN THE HRRR IS
PREFERRED.
SENSIBLE WEATHER WILL FEATURE THE CURRENT CONVECTION WINDING DOWN
LATER THIS MORNING IN THE SOUTH WITH BUILDING INSTABILITY POSSIBLY
HELPING TO KICK OFF SOME MORE IN THE FAR EAST LATER IN THE
AFTERNOON...SIMILAR TO WHAT OCCURRED ON TUESDAY. THIS SHOULD BE THE
LAST THREAT OF CONVECTION THROUGH THE SHORT TERM...THOUGH...AS
LIMITED UPPER LEVEL SUPPORT AND WEAK SFC HIGH PRESSURE WILL LIKELY
SUPPRESS CONVECTION AFTER 00Z TONIGHT. AS SUCH...WE CAN EXPECT
ANOTHER WARM AND HUMID COUPLE OF DAYS WITH HEAT INDICES MAXING OUT
BETWEEN 95 AND 100 DEGREES EACH AFTERNOON. WILL MENTION THIS IN THE
FORTHCOMING HWO. AT NIGHT...PATCHY VALLEY FOG WILL BE THE NORM WITH A
SMALL RIDGE TO VALLEY TEMPERATURE SPLIT EACH NIGHT AS TEMPERATURES
AND DEWPOINTS KEEP A MUGGINESS IN THE AIR...AND PATCHY FOG IN THE
VALLEYS TOWARD DAWN.
FOLLOWED A BLEND OF PERSISTENCE...EXISTING GRIDS...AND THE LATEST
MET GUIDANCE FOR TEMPERATURES THROUGH THE SHORT TERM. AS FOR POPS...
ENDED UP JUST ON THE HIGH SIDE OF GUIDANCE TODAY AND IN LINE WITH IT
FOR TONIGHT AND THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM EDT WED AUG 1 2012
OVERALL...THE LONG TERM LOOKS TO BE UNSETTLED WITH QUITE A BIT OF
RAIN POTENTIAL OVER THE PERIOD. A BERMUDA HIGH IS EXPECTED TO BE
STRENGTHENING OVER THE ERN U.S. WHILE AN AREA OF LOW PRESSURE GAINS
MOMENTUM OVER CANADIAN PRAIRIES BENEATH A RELATIVELY ZONAL FLOW
ALOFT OVER THE OHIO VALLEY TO START THE PERIOD. RETURN FLOW IS
EXPECTED TO BE UNDER WAY BY FRIDAY...USHERING AMPLE MOISTURE BACK
INTO THE REGION WITH PWATS PROGGED TO BE AROUND 2 INCHES FROM LATE
FRIDAY THROUGH SUNDAY AFTERNOON.
GUIDANCE CONTINUES TO POINT TOWARDS A COUPLE OF SHORT WAVES SKIRTING
THE AREA AROUND THE FRIDAY/SATURDAY TIME FRAME. THE LATEST GFS ALONG
WITH THE GEM ARE STILL ADVERTISING A RATHER POTENT WAVE REACHING THE
TN VALLEY ON FRIDAY IN CONJUNCTION WITH MODEST ISENTROPIC LIFT AT
H85 OVER ERN KY DURING THE AFTERNOON. STILL NOT CONFIDENT ENOUGH TO
GO HIGHER THAN CHANCE AT THIS POINT BUT ANOTHER ROUND OF OFFERINGS
WITH THE SAME SOLUTIONS SHOULD WARRANT A BUMP UP TO LIKELY POPS FOR
AT LEAST PART OF THE CWA ON FRIDAY. SATURDAY IS LOOKING SIMILAR TO
FRIDAY...THOUGH WITH LESS IN THE WAY OF SHORT WAVE TRIGGERS...BUT
ATTAINABLE FCST CONVECTIVE TEMPS IN THE LOWER 80S ALONG WITH ANY
REMNANT BOUNDARIES FROM FRIDAY MAY BE ENOUGH TO GET THINGS GOING
BEFORE OUTFLOW PROCESSES TAKE OVER.
FOCUS THEN SHIFTS TO AN ALBERTA CLIPPER SYSTEM MOVING THROUGH THE
UPPER MIDWEST AND INTO THE GREAT LAKES ON SUNDAY. THE MODELS
CONTINUE TO COME INTO BETTER ALIGNMENT WITH THE TIMING OF THE SYSTEM
OVERALL. FORCING ASSOCIATED WITH THE COLD FRONT LOOKS TO BEGIN
APPROACHING THE AREA ON SUNDAY WITH SHOWERS AND THUNDERSTORMS
OVERSPREADING THE AREA DURING THE AFTERNOON AND EVENING BEFORE UPPER
LEVEL SUPPORT ARRIVES SUNDAY NIGHT INTO MONDAY. MODELS STILL SUGGEST
THE FRONT STALLING OVER THE AREA ON MONDAY AND DESPITE WHAT SHOULD
BE DIMINISHING MOISTURE BY THAT POINT...WILL KEEP CHANCE POPS FOR
MONDAY TO ACCOUNT FOR MODELS TENDENCIES TO BE A LITTLE FAST IN
MOVING THINGS OUT TOO QUICKLY THIS FAR OUT.
GIVEN THE INCREASING AGREEMENT AMONG THE MODELS...STAYED FAIRLY
CLOSE TO THE CONSENSUS NUMBERS FOR TEMPS THROUGHOUT THE PERIOD. THIS
RESULTED IN HIGHS ON FRIDAY AND SATURDAY RUNNING ABOVE NORMAL
BEFORE SLIDING BACK TOWARDS CLIMO FROM SUNDAY ONWARD. AFTER A MODEST
RIDGE/VALLEY SPLIT THURSDAY NIGHT...LOWS LOOK TO REMAIN WITHIN REACH
OF NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 150 PM EDT WED AUG 1 2012
EXPECT SOME ISOLATED CONVECTION TO POP UP THROUGH THE REST OF THIS
AFTERNOON BEFORE DISSIPATING BY DUSK. ANY STORMS WILL BRING IFR
CONDITIONS OR WORSE...BUT GENERALLY LESS THAN 15 MINUTES OVER A GIVEN
LOCATION. GIVEN THE ISOLATED COVERAGE...WILL CONTINUE TO NOT MENTION
THESE AT THE TAF SITES. FOG WILL LIKELY FORM IN THE VALLEYS
TONIGHT...AND HAVE INCLUDED TEMPORARY IFR CONDITIONS FOR LOZ AND
SME...OTHERWISE VFR CONDITIONS WILL PREVAIL THE MAJORITY OF THE TIME
THROUGH THE PERIOD. WEST WINDS BETWEEN 5 AND 10 KTS WILL BECOME
LIGHT AND VARIABLE BY DUSK.
STRAY CONVECTION CONTINUES TO SPARSELY AFFECT THE AREA EARLY THIS
MORNING. THIS SHOULD CLEAR UP BY 14Z. OTHERWISE...VFR CONDITIONS WILL
DOMINATE THROUGH THE PERIOD. EXPECT TO SEE SOME PATCHY DENSE VALLEY
FOG LATE TONIGHT AND INTO EARLY THURSDAY MORNING...BUT THE MAIN TAF
SITES SHOULD REMAIN CLEAR. OUTSIDE OF ANY STRAY THUNDERSTORMS
TODAY...THE WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM....MB
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT WED AUG 1 2012
.UPDATE...
ISSUED AT 1057 AM EDT WED AUG 1 2012
MORNING CONVECTION DIMINISHED BETWEEN 9 AND 10 AM...AS SCHEDULED.
TEMPERATURES CAME IN COOLER THIS MORNING COMPARED TO TUESDAY
MORNING...AND THIS HAS HAMPERED THE DIURNAL RISE SO FAR. HAVE LOWERED
THE HIGHS A TOUCH TO ACCOUNT FOR THIS TREND...BUT GENERALLY MOST
LOCATIONS WILL STILL SEE AROUND 90. A WEAK STATIONARY FRONT REMAINS
DRAPED FROM JUST SOUTH OF A LINE FROM KEVV...TO KSDF...TO KILN.
ANOTHER SHORT WAVE TROUGH...CURRENTLY MOVING SOUTHEAST ACROSS INDIANA
WILL ALSO MOVE INTO EASTERN KENTUCKY THIS AFTERNOON. GIVEN THESE TWO
FEATURES...HAVE GONE AHEAD AND INCLUDED SLIGHT CHANCE POPS FOR ALL.
THE HRRR HAS BEEN GENERATING SOME CONVECTION ACROSS MOST OF THE
AREA...ALTHOUGH THE 06 AND 12Z NAM RUNS HAVE REMAINED DRY. THE
FORECAST SOUNDINGS HAVE TRENDED A BIT WEAKER WITH THE CAP THIS
AFTERNOON...AND THERE IS PLENTY OF DRY AIR ALOFT...WITH MUCH LOWER
WET-BULB ZERO HEIGHTS TODAY. WILL HAVE TO WATCH FOR A FEW PULSERS
THAT CAN TAKE ADVANTAGE OF THIS ENVIRONMENT.
UPDATE ISSUED AT 750 AM EDT WED AUG 1 2012
UPDATED THE GRIDS...MINORLY...TO BETTER REFLECT POPS EARLY THIS
MORNING. ALSO TWEAKED SKY...T AND TD GRIDS FOR CURRENT OBS AND
TRENDS. UPDATES HAVE BEEN SENT TO NDFD AND THE WEB.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT WED AUG 1 2012
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE LAYING ACROSS THE
NORTHWEST PORTION OF EASTERN KENTUCKY...RELATED TO A MINOR COLD FRONT
THAT IS PASSING THROUGH THE AREA EARLY THIS MORNING. THIS HAS JUST
RECENTLY HELPED TO TRIGGER A FEW CELLS OF CONVECTION IN THE WESTERN
PARTS OF THE CUMBERLAND VALLEY...DRIFTING SOUTHEAST INTO THE
SOUTHERN INTERSTATE 75 CORRIDOR. ON SATELLITE...THE CLOUDS HAVE
INCREASED DURING THE PAST COUPLE OF HOURS IN RESPONSE TO THE
BOUNDARY AND SOME ENERGY PASSING THROUGH AT MID LEVELS. THE CLOUDS
WILL HELP TO LIMIT ANY FURTHER DROP IN TEMPERATURES THROUGH THE REST
OF THE NIGHT. AS IT STANDS...A MINOR RIDGE TO VALLEY TEMPERATURE
SPLIT ON THE ORDER OF ABOUT 5 DEGREES EXISTS OUT THERE...MAINLY IN
THE NORTHEAST AS OF 3 AM EDT. LOW DEWPOINT DEPRESSIONS ARE ALSO
FOUND IN THE VALLEYS AND ANY PLACE THAT MANAGE TO STAY MOSTLY CLEAR
CAN EXPECT PATCHY FOG IN THE VALLEYS TOWARD DAWN...POSSIBLY DENSE IN
LOCATIONS CLOSER TO THE VIRGINIA BORDER THAT SAW SOME DECENT RAINS ON
TUESDAY AFTERNOON.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT WITH THE MAIN FEATURES
AFFECTING THE SHORT TERM FORECAST. THEY AGREE THAT STRONG RIDGING
WILL REMAIN PARKED OFF TO THE SOUTHWEST OF THE AREA...IN NORTHERN
TEXAS...AND THAT THE EASTERN THIRD OF THE NATION WILL BE IN BROAD
TROUGHING...DOWNSTREAM OF THE RIDGE. LOCALLY...EAST KENTUCKY WILL BE
UNDER THE INFLUENCE OF NORTHWEST FLOW WITH A COUPLE OF WEAK
SHORTWAVES PASSING OVERHEAD INTO THURSDAY. ONE OF THESE WAVES IS
PASSING THIS MORNING AND IS PARTIALLY RESPONSIBLE FOR THE CURRENT
CONVECTION IMPACTING OUR WESTERNMOST COUNTIES. THE NEXT WILL COME
THROUGH THIS EVENING AND SHOULD BRING AN UPTICK IN CONVECTIVE
POTENTIAL TO THE AREA...THOUGH ITS BEST INFLUENCE WILL LIKELY BE FELT
FURTHER TO THE EAST. TOWARD THE END OF THE PERIOD...THE PATTERN
BECOMES MORE ZONAL AS THE EASTERN TROUGH STARTS TO FLATTEN OUT AND
THE WESTERN RIDGE SHIFTS SOUTH. GIVEN THE MODEL SIMILARITIES HAVE
FOLLOWED A BLENDED SOLUTION WITH A STRONG LEAN TOWARD THE HIGHER
RESOLUTION NAM12 OUTSIDE OF THE NEXT 12 HOURS...WHEN THE HRRR IS
PREFERRED.
SENSIBLE WEATHER WILL FEATURE THE CURRENT CONVECTION WINDING DOWN
LATER THIS MORNING IN THE SOUTH WITH BUILDING INSTABILITY POSSIBLY
HELPING TO KICK OFF SOME MORE IN THE FAR EAST LATER IN THE
AFTERNOON...SIMILAR TO WHAT OCCURRED ON TUESDAY. THIS SHOULD BE THE
LAST THREAT OF CONVECTION THROUGH THE SHORT TERM...THOUGH...AS
LIMITED UPPER LEVEL SUPPORT AND WEAK SFC HIGH PRESSURE WILL LIKELY
SUPPRESS CONVECTION AFTER 00Z TONIGHT. AS SUCH...WE CAN EXPECT
ANOTHER WARM AND HUMID COUPLE OF DAYS WITH HEAT INDICES MAXING OUT
BETWEEN 95 AND 100 DEGREES EACH AFTERNOON. WILL MENTION THIS IN THE
FORTHCOMING HWO. AT NIGHT...PATCHY VALLEY FOG WILL BE THE NORM WITH A
SMALL RIDGE TO VALLEY TEMPERATURE SPLIT EACH NIGHT AS TEMPERATURES
AND DEWPOINTS KEEP A MUGGINESS IN THE AIR...AND PATCHY FOG IN THE
VALLEYS TOWARD DAWN.
FOLLOWED A BLEND OF PERSISTENCE...EXISTING GRIDS...AND THE LATEST
MET GUIDANCE FOR TEMPERATURES THROUGH THE SHORT TERM. AS FOR POPS...
ENDED UP JUST ON THE HIGH SIDE OF GUIDANCE TODAY AND IN LINE WITH IT
FOR TONIGHT AND THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM EDT WED AUG 1 2012
OVERALL...THE LONG TERM LOOKS TO BE UNSETTLED WITH QUITE A BIT OF
RAIN POTENTIAL OVER THE PERIOD. A BERMUDA HIGH IS EXPECTED TO BE
STRENGTHENING OVER THE ERN U.S. WHILE AN AREA OF LOW PRESSURE GAINS
MOMENTUM OVER CANADIAN PRAIRIES BENEATH A RELATIVELY ZONAL FLOW
ALOFT OVER THE OHIO VALLEY TO START THE PERIOD. RETURN FLOW IS
EXPECTED TO BE UNDER WAY BY FRIDAY...USHERING AMPLE MOISTURE BACK
INTO THE REGION WITH PWATS PROGGED TO BE AROUND 2 INCHES FROM LATE
FRIDAY THROUGH SUNDAY AFTERNOON.
GUIDANCE CONTINUES TO POINT TOWARDS A COUPLE OF SHORT WAVES SKIRTING
THE AREA AROUND THE FRIDAY/SATURDAY TIME FRAME. THE LATEST GFS ALONG
WITH THE GEM ARE STILL ADVERTISING A RATHER POTENT WAVE REACHING THE
TN VALLEY ON FRIDAY IN CONJUNCTION WITH MODEST ISENTROPIC LIFT AT
H85 OVER ERN KY DURING THE AFTERNOON. STILL NOT CONFIDENT ENOUGH TO
GO HIGHER THAN CHANCE AT THIS POINT BUT ANOTHER ROUND OF OFFERINGS
WITH THE SAME SOLUTIONS SHOULD WARRANT A BUMP UP TO LIKELY POPS FOR
AT LEAST PART OF THE CWA ON FRIDAY. SATURDAY IS LOOKING SIMILAR TO
FRIDAY...THOUGH WITH LESS IN THE WAY OF SHORT WAVE TRIGGERS...BUT
ATTAINABLE FCST CONVECTIVE TEMPS IN THE LOWER 80S ALONG WITH ANY
REMNANT BOUNDARIES FROM FRIDAY MAY BE ENOUGH TO GET THINGS GOING
BEFORE OUTFLOW PROCESSES TAKE OVER.
FOCUS THEN SHIFTS TO AN ALBERTA CLIPPER SYSTEM MOVING THROUGH THE
UPPER MIDWEST AND INTO THE GREAT LAKES ON SUNDAY. THE MODELS
CONTINUE TO COME INTO BETTER ALIGNMENT WITH THE TIMING OF THE SYSTEM
OVERALL. FORCING ASSOCIATED WITH THE COLD FRONT LOOKS TO BEGIN
APPROACHING THE AREA ON SUNDAY WITH SHOWERS AND THUNDERSTORMS
OVERSPREADING THE AREA DURING THE AFTERNOON AND EVENING BEFORE UPPER
LEVEL SUPPORT ARRIVES SUNDAY NIGHT INTO MONDAY. MODELS STILL SUGGEST
THE FRONT STALLING OVER THE AREA ON MONDAY AND DESPITE WHAT SHOULD
BE DIMINISHING MOISTURE BY THAT POINT...WILL KEEP CHANCE POPS FOR
MONDAY TO ACCOUNT FOR MODELS TENDENCIES TO BE A LITTLE FAST IN
MOVING THINGS OUT TOO QUICKLY THIS FAR OUT.
GIVEN THE INCREASING AGREEMENT AMONG THE MODELS...STAYED FAIRLY
CLOSE TO THE CONSENSUS NUMBERS FOR TEMPS THROUGHOUT THE PERIOD. THIS
RESULTED IN HIGHS ON FRIDAY AND SATURDAY RUNNING ABOVE NORMAL
BEFORE SLIDING BACK TOWARDS CLIMO FROM SUNDAY ONWARD. AFTER A MODEST
RIDGE/VALLEY SPLIT THURSDAY NIGHT...LOWS LOOK TO REMAIN WITHIN REACH
OF NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 750 AM EDT WED AUG 1 2012
STRAY CONVECTION CONTINUES TO SPARSELY AFFECT THE AREA EARLY THIS
MORNING. THIS SHOULD CLEAR UP BY 14Z. OTHERWISE...VFR CONDITIONS
WILL DOMINATE THROUGH THE PERIOD. EXPECT TO SEE SOME PATCHY DENSE
VALLEY FOG LATE TONIGHT AND INTO EARLY THURSDAY MORNING...BUT THE
MAIN TAF SITES SHOULD REMAIN CLEAR. OUTSIDE OF ANY STRAY
THUNDERSTORMS TODAY...THE WINDS WILL BE LIGHT AND VARIABLE THROUGH
THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM....MB
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
750 AM EDT WED AUG 1 2012
.UPDATE...
ISSUED AT 750 AM EDT WED AUG 1 2012
UPDATED THE GRIDS...MINORLY...TO BETTER REFLECT POPS EARLY THIS
MORNING. ALSO TWEAKED SKY...T AND TD GRIDS FOR CURRENT OBS AND
TRENDS. UPDATES HAVE BEEN SENT TO NDFD AND THE WEB.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT WED AUG 1 2012
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE LAYING ACROSS THE
NORTHWEST PORTION OF EASTERN KENTUCKY...RELATED TO A MINOR COLD FRONT
THAT IS PASSING THROUGH THE AREA EARLY THIS MORNING. THIS HAS JUST
RECENTLY HELPED TO TRIGGER A FEW CELLS OF CONVECTION IN THE WESTERN
PARTS OF THE CUMBERLAND VALLEY...DRIFTING SOUTHEAST INTO THE
SOUTHERN INTERSTATE 75 CORRIDOR. ON SATELLITE...THE CLOUDS HAVE
INCREASED DURING THE PAST COUPLE OF HOURS IN RESPONSE TO THE
BOUNDARY AND SOME ENERGY PASSING THROUGH AT MID LEVELS. THE CLOUDS
WILL HELP TO LIMIT ANY FURTHER DROP IN TEMPERATURES THROUGH THE REST
OF THE NIGHT. AS IT STANDS...A MINOR RIDGE TO VALLEY TEMPERATURE
SPLIT ON THE ORDER OF ABOUT 5 DEGREES EXISTS OUT THERE...MAINLY IN
THE NORTHEAST AS OF 3 AM EDT. LOW DEWPOINT DEPRESSIONS ARE ALSO
FOUND IN THE VALLEYS AND ANY PLACE THAT MANAGE TO STAY MOSTLY CLEAR
CAN EXPECT PATCHY FOG IN THE VALLEYS TOWARD DAWN...POSSIBLY DENSE IN
LOCATIONS CLOSER TO THE VIRGINIA BORDER THAT SAW SOME DECENT RAINS ON
TUESDAY AFTERNOON.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT WITH THE MAIN FEATURES
AFFECTING THE SHORT TERM FORECAST. THEY AGREE THAT STRONG RIDGING
WILL REMAIN PARKED OFF TO THE SOUTHWEST OF THE AREA...IN NORTHERN
TEXAS...AND THAT THE EASTERN THIRD OF THE NATION WILL BE IN BROAD
TROUGHING...DOWNSTREAM OF THE RIDGE. LOCALLY...EAST KENTUCKY WILL BE
UNDER THE INFLUENCE OF NORTHWEST FLOW WITH A COUPLE OF WEAK
SHORTWAVES PASSING OVERHEAD INTO THURSDAY. ONE OF THESE WAVES IS
PASSING THIS MORNING AND IS PARTIALLY RESPONSIBLE FOR THE CURRENT
CONVECTION IMPACTING OUR WESTERNMOST COUNTIES. THE NEXT WILL COME
THROUGH THIS EVENING AND SHOULD BRING AN UPTICK IN CONVECTIVE
POTENTIAL TO THE AREA...THOUGH ITS BEST INFLUENCE WILL LIKELY BE FELT
FURTHER TO THE EAST. TOWARD THE END OF THE PERIOD...THE PATTERN
BECOMES MORE ZONAL AS THE EASTERN TROUGH STARTS TO FLATTEN OUT AND
THE WESTERN RIDGE SHIFTS SOUTH. GIVEN THE MODEL SIMILARITIES HAVE
FOLLOWED A BLENDED SOLUTION WITH A STRONG LEAN TOWARD THE HIGHER
RESOLUTION NAM12 OUTSIDE OF THE NEXT 12 HOURS...WHEN THE HRRR IS
PREFERRED.
SENSIBLE WEATHER WILL FEATURE THE CURRENT CONVECTION WINDING DOWN
LATER THIS MORNING IN THE SOUTH WITH BUILDING INSTABILITY POSSIBLY
HELPING TO KICK OFF SOME MORE IN THE FAR EAST LATER IN THE
AFTERNOON...SIMILAR TO WHAT OCCURRED ON TUESDAY. THIS SHOULD BE THE
LAST THREAT OF CONVECTION THROUGH THE SHORT TERM...THOUGH...AS
LIMITED UPPER LEVEL SUPPORT AND WEAK SFC HIGH PRESSURE WILL LIKELY
SUPPRESS CONVECTION AFTER 00Z TONIGHT. AS SUCH...WE CAN EXPECT
ANOTHER WARM AND HUMID COUPLE OF DAYS WITH HEAT INDICES MAXING OUT
BETWEEN 95 AND 100 DEGREES EACH AFTERNOON. WILL MENTION THIS IN THE
FORTHCOMING HWO. AT NIGHT...PATCHY VALLEY FOG WILL BE THE NORM WITH A
SMALL RIDGE TO VALLEY TEMPERATURE SPLIT EACH NIGHT AS TEMPERATURES
AND DEWPOINTS KEEP A MUGGINESS IN THE AIR...AND PATCHY FOG IN THE
VALLEYS TOWARD DAWN.
FOLLOWED A BLEND OF PERSISTENCE...EXISTING GRIDS...AND THE LATEST
MET GUIDANCE FOR TEMPERATURES THROUGH THE SHORT TERM. AS FOR POPS...
ENDED UP JUST ON THE HIGH SIDE OF GUIDANCE TODAY AND IN LINE WITH IT
FOR TONIGHT AND THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM EDT WED AUG 1 2012
OVERALL...THE LONG TERM LOOKS TO BE UNSETTLED WITH QUITE A BIT OF
RAIN POTENTIAL OVER THE PERIOD. A BERMUDA HIGH IS EXPECTED TO BE
STRENGTHENING OVER THE ERN U.S. WHILE AN AREA OF LOW PRESSURE GAINS
MOMENTUM OVER CANADIAN PRAIRIES BENEATH A RELATIVELY ZONAL FLOW
ALOFT OVER THE OHIO VALLEY TO START THE PERIOD. RETURN FLOW IS
EXPECTED TO BE UNDER WAY BY FRIDAY...USHERING AMPLE MOISTURE BACK
INTO THE REGION WITH PWATS PROGGED TO BE AROUND 2 INCHES FROM LATE
FRIDAY THROUGH SUNDAY AFTERNOON.
GUIDANCE CONTINUES TO POINT TOWARDS A COUPLE OF SHORT WAVES SKIRTING
THE AREA AROUND THE FRIDAY/SATURDAY TIME FRAME. THE LATEST GFS ALONG
WITH THE GEM ARE STILL ADVERTISING A RATHER POTENT WAVE REACHING THE
TN VALLEY ON FRIDAY IN CONJUNCTION WITH MODEST ISENTROPIC LIFT AT
H85 OVER ERN KY DURING THE AFTERNOON. STILL NOT CONFIDENT ENOUGH TO
GO HIGHER THAN CHANCE AT THIS POINT BUT ANOTHER ROUND OF OFFERINGS
WITH THE SAME SOLUTIONS SHOULD WARRANT A BUMP UP TO LIKELY POPS FOR
AT LEAST PART OF THE CWA ON FRIDAY. SATURDAY IS LOOKING SIMILAR TO
FRIDAY...THOUGH WITH LESS IN THE WAY OF SHORT WAVE TRIGGERS...BUT
ATTAINABLE FCST CONVECTIVE TEMPS IN THE LOWER 80S ALONG WITH ANY
REMNANT BOUNDARIES FROM FRIDAY MAY BE ENOUGH TO GET THINGS GOING
BEFORE OUTFLOW PROCESSES TAKE OVER.
FOCUS THEN SHIFTS TO AN ALBERTA CLIPPER SYSTEM MOVING THROUGH THE
UPPER MIDWEST AND INTO THE GREAT LAKES ON SUNDAY. THE MODELS
CONTINUE TO COME INTO BETTER ALIGNMENT WITH THE TIMING OF THE SYSTEM
OVERALL. FORCING ASSOCIATED WITH THE COLD FRONT LOOKS TO BEGIN
APPROACHING THE AREA ON SUNDAY WITH SHOWERS AND THUNDERSTORMS
OVERSPREADING THE AREA DURING THE AFTERNOON AND EVENING BEFORE UPPER
LEVEL SUPPORT ARRIVES SUNDAY NIGHT INTO MONDAY. MODELS STILL SUGGEST
THE FRONT STALLING OVER THE AREA ON MONDAY AND DESPITE WHAT SHOULD
BE DIMINISHING MOISTURE BY THAT POINT...WILL KEEP CHANCE POPS FOR
MONDAY TO ACCOUNT FOR MODELS TENDENCIES TO BE A LITTLE FAST IN
MOVING THINGS OUT TOO QUICKLY THIS FAR OUT.
GIVEN THE INCREASING AGREEMENT AMONG THE MODELS...STAYED FAIRLY
CLOSE TO THE CONSENSUS NUMBERS FOR TEMPS THROUGHOUT THE PERIOD. THIS
RESULTED IN HIGHS ON FRIDAY AND SATURDAY RUNNING ABOVE NORMAL
BEFORE SLIDING BACK TOWARDS CLIMO FROM SUNDAY ONWARD. AFTER A MODEST
RIDGE/VALLEY SPLIT THURSDAY NIGHT...LOWS LOOK TO REMAIN WITHIN REACH
OF NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 750 AM EDT WED AUG 1 2012
STRAY CONVECTION CONTINUES TO SPARSELY AFFECT THE AREA EARLY THIS
MORNING. THIS SHOULD CLEAR UP BY 14Z. OTHERWISE...VFR CONDITIONS
WILL DOMINATE THROUGH THE PERIOD. EXPECT TO SEE SOME PATCHY DENSE
VALLEY FOG LATE TONIGHT AND INTO EARLY THURSDAY MORNING...BUT THE
MAIN TAF SITES SHOULD REMAIN CLEAR. OUTSIDE OF ANY STRAY
THUNDERSTORMS TODAY...THE WINDS WILL BE LIGHT AND VARIABLE THROUGH
THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM....MB
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
355 AM EDT WED AUG 1 2012
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT WED AUG 1 2012
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE LAYING ACROSS THE
NORTHWEST PORTION OF EASTERN KENTUCKY...RELATED TO A MINOR COLD FRONT
THAT IS PASSING THROUGH THE AREA EARLY THIS MORNING. THIS HAS JUST
RECENTLY HELPED TO TRIGGER A FEW CELLS OF CONVECTION IN THE WESTERN
PARTS OF THE CUMBERLAND VALLEY...DRIFTING SOUTHEAST INTO THE
SOUTHERN INTERSTATE 75 CORRIDOR. ON SATELLITE...THE CLOUDS HAVE
INCREASED DURING THE PAST COUPLE OF HOURS IN RESPONSE TO THE
BOUNDARY AND SOME ENERGY PASSING THROUGH AT MID LEVELS. THE CLOUDS
WILL HELP TO LIMIT ANY FURTHER DROP IN TEMPERATURES THROUGH THE REST
OF THE NIGHT. AS IT STANDS...A MINOR RIDGE TO VALLEY TEMPERATURE
SPLIT ON THE ORDER OF ABOUT 5 DEGREES EXISTS OUT THERE...MAINLY IN
THE NORTHEAST AS OF 3 AM EDT. LOW DEWPOINT DEPRESSIONS ARE ALSO
FOUND IN THE VALLEYS AND ANY PLACE THAT MANAGE TO STAY MOSTLY CLEAR
CAN EXPECT PATCHY FOG IN THE VALLEYS TOWARD DAWN...POSSIBLY DENSE IN
LOCATIONS CLOSER TO THE VIRGINIA BORDER THAT SAW SOME DECENT RAINS ON
TUESDAY AFTERNOON.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT WITH THE MAIN FEATURES
AFFECTING THE SHORT TERM FORECAST. THEY AGREE THAT STRONG RIDGING
WILL REMAIN PARKED OFF TO THE SOUTHWEST OF THE AREA...IN NORTHERN
TEXAS...AND THAT THE EASTERN THIRD OF THE NATION WILL BE IN BROAD
TROUGHING...DOWNSTREAM OF THE RIDGE. LOCALLY...EAST KENTUCKY WILL BE
UNDER THE INFLUENCE OF NORTHWEST FLOW WITH A COUPLE OF WEAK
SHORTWAVES PASSING OVERHEAD INTO THURSDAY. ONE OF THESE WAVES IS
PASSING THIS MORNING AND IS PARTIALLY RESPONSIBLE FOR THE CURRENT
CONVECTION IMPACTING OUR WESTERNMOST COUNTIES. THE NEXT WILL COME
THROUGH THIS EVENING AND SHOULD BRING AN UPTICK IN CONVECTIVE
POTENTIAL TO THE AREA...THOUGH ITS BEST INFLUENCE WILL LIKELY BE FELT
FURTHER TO THE EAST. TOWARD THE END OF THE PERIOD...THE PATTERN
BECOMES MORE ZONAL AS THE EASTERN TROUGH STARTS TO FLATTEN OUT AND
THE WESTERN RIDGE SHIFTS SOUTH. GIVEN THE MODEL SIMILARITIES HAVE
FOLLOWED A BLENDED SOLUTION WITH A STRONG LEAN TOWARD THE HIGHER
RESOLUTION NAM12 OUTSIDE OF THE NEXT 12 HOURS...WHEN THE HRRR IS
PREFERRED.
SENSIBLE WEATHER WILL FEATURE THE CURRENT CONVECTION WINDING DOWN
LATER THIS MORNING IN THE SOUTH WITH BUILDING INSTABILITY POSSIBLY
HELPING TO KICK OFF SOME MORE IN THE FAR EAST LATER IN THE
AFTERNOON...SIMILAR TO WHAT OCCURRED ON TUESDAY. THIS SHOULD BE THE
LAST THREAT OF CONVECTION THROUGH THE SHORT TERM...THOUGH...AS
LIMITED UPPER LEVEL SUPPORT AND WEAK SFC HIGH PRESSURE WILL LIKELY
SUPPRESS CONVECTION AFTER 00Z TONIGHT. AS SUCH...WE CAN EXPECT
ANOTHER WARM AND HUMID COUPLE OF DAYS WITH HEAT INDICES MAXING OUT
BETWEEN 95 AND 100 DEGREES EACH AFTERNOON. WILL MENTION THIS IN THE
FORTHCOMING HWO. AT NIGHT...PATCHY VALLEY FOG WILL BE THE NORM WITH A
SMALL RIDGE TO VALLEY TEMPERATURE SPLIT EACH NIGHT AS TEMPERATURES
AND DEWPOINTS KEEP A MUGGINESS IN THE AIR...AND PATCHY FOG IN THE
VALLEYS TOWARD DAWN.
FOLLOWED A BLEND OF PERSISTENCE...EXISTING GRIDS...AND THE LATEST
MET GUIDANCE FOR TEMPERATURES THROUGH THE SHORT TERM. AS FOR POPS...
ENDED UP JUST ON THE HIGH SIDE OF GUIDANCE TODAY AND IN LINE WITH IT
FOR TONIGHT AND THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM EDT WED AUG 1 2012
OVERALL...THE LONG TERM LOOKS TO BE UNSETTLED WITH QUITE A BIT OF
RAIN POTENTIAL OVER THE PERIOD. A BERMUDA HIGH IS EXPECTED TO BE
STRENGTHENING OVER THE ERN U.S. WHILE AN AREA OF LOW PRESSURE GAINS
MOMENTUM OVER CANADIAN PRAIRIES BENEATH A RELATIVELY ZONAL FLOW
ALOFT OVER THE OHIO VALLEY TO START THE PERIOD. RETURN FLOW IS
EXPECTED TO BE UNDER WAY BY FRIDAY...USHERING AMPLE MOISTURE BACK
INTO THE REGION WITH PWATS PROGGED TO BE AROUND 2 INCHES FROM LATE
FRIDAY THROUGH SUNDAY AFTERNOON.
GUIDANCE CONTINUES TO POINT TOWARDS A COUPLE OF SHORT WAVES SKIRTING
THE AREA AROUND THE FRIDAY/SATURDAY TIME FRAME. THE LATEST GFS ALONG
WITH THE GEM ARE STILL ADVERTISING A RATHER POTENT WAVE REACHING THE
TN VALLEY ON FRIDAY IN CONJUNCTION WITH MODEST ISENTROPIC LIFT AT
H85 OVER ERN KY DURING THE AFTERNOON. STILL NOT CONFIDENT ENOUGH TO
GO HIGHER THAN CHANCE AT THIS POINT BUT ANOTHER ROUND OF OFFERINGS
WITH THE SAME SOLUTIONS SHOULD WARRANT A BUMP UP TO LIKELY POPS FOR
AT LEAST PART OF THE CWA ON FRIDAY. SATURDAY IS LOOKING SIMILAR TO
FRIDAY...THOUGH WITH LESS IN THE WAY OF SHORT WAVE TRIGGERS...BUT
ATTAINABLE FCST CONVECTIVE TEMPS IN THE LOWER 80S ALONG WITH ANY
REMNANT BOUNDARIES FROM FRIDAY MAY BE ENOUGH TO GET THINGS GOING
BEFORE OUTFLOW PROCESSES TAKE OVER.
FOCUS THEN SHIFTS TO AN ALBERTA CLIPPER SYSTEM MOVING THROUGH THE
UPPER MIDWEST AND INTO THE GREAT LAKES ON SUNDAY. THE MODELS
CONTINUE TO COME INTO BETTER ALIGNMENT WITH THE TIMING OF THE SYSTEM
OVERALL. FORCING ASSOCIATED WITH THE COLD FRONT LOOKS TO BEGIN
APPROACHING THE AREA ON SUNDAY WITH SHOWERS AND THUNDERSTORMS
OVERSPREADING THE AREA DURING THE AFTERNOON AND EVENING BEFORE UPPER
LEVEL SUPPORT ARRIVES SUNDAY NIGHT INTO MONDAY. MODELS STILL SUGGEST
THE FRONT STALLING OVER THE AREA ON MONDAY AND DESPITE WHAT SHOULD
BE DIMINISHING MOISTURE BY THAT POINT...WILL KEEP CHANCE POPS FOR
MONDAY TO ACCOUNT FOR MODELS TENDENCIES TO BE A LITTLE FAST IN
MOVING THINGS OUT TOO QUICKLY THIS FAR OUT.
GIVEN THE INCREASING AGREEMENT AMONG THE MODELS...STAYED FAIRLY
CLOSE TO THE CONSENSUS NUMBERS FOR TEMPS THROUGHOUT THE PERIOD. THIS
RESULTED IN HIGHS ON FRIDAY AND SATURDAY RUNNING ABOVE NORMAL
BEFORE SLIDING BACK TOWARDS CLIMO FROM SUNDAY ONWARD. AFTER A MODEST
RIDGE/VALLEY SPLIT THURSDAY NIGHT...LOWS LOOK TO REMAIN WITHIN REACH
OF NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 215 AM EDT WED AUG 1 2012
CONVECTION IS POPPING UP TO THE NORTHWEST OF PART OF THE FORECAST
AREA IN RELATION TO AN APPROACHING SFC BOUNDARY AND SOME ENERGY
ALOFT. HAVE PUSHED UP THE TIME OF THE VCSH IN THE EXISTING TAFS FOR
EARLY THIS MORNING. WILL HAVE TO MONITOR FOR A POSSIBLE VCTS AND CB
ADDITION AS THIS SCENARIO UNFOLDS OVER THE NEXT COUPLE OF HOURS. DO
EXPECT THE ACTIVITY TO SETTLE BY MID MORNING AND HAVE DROPPED ANY
MENTION OF PCPN BY THAT TIME. OTHERWISE...VFR CONDITIONS WILL
DOMINATE THROUGH THE PERIOD. DO STILL EXPECT TO SEE SOME PATCHY DENSE
VALLEY FOG LATE TONIGHT AND EARLY THIS MORNING...ESPECIALLY OVER
AREAS IN THE FAR SOUTHEAST THAT SAW THE RAIN YESTERDAY AFTERNOON...
BUT THE MAIN TAF SITES SHOULD REMAIN CLEAR. OUTSIDE OF ANY STRAY
THUNDERSTORMS...THE WINDS WILL BE LIGHT AND VARIABLE THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM....MB
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 AM EDT WED AUG 1 2012
.UPDATE...
ISSUED AT 205 AM EDT WED AUG 1 2012
DID A QUICK PRE-PACKAGE UPDATE TO NUDGE UP POPS IN THE WESTERN
CUMBERLAND VALLEY FOR A FEW HOURS WITH THE NOCTURNAL CONVECTION NOW
SPROUTING TO THE AREA/S NORTHWEST. ALSO TWEAKED SKY...T...AND TD
GRIDS TO REFLECT CURRENT OBS AND TRENDS. UPDATES HAVE BEEN SENT TO
NDFD AND THE WEB.
UPDATE ISSUED AT 1029 PM EDT TUE JUL 31 2012
THE SHOWER ES AND THUNDERSTORMS HAVE MOVED OUT OF KENTUCKY INTO
VIRGINIA. A COLD FRONT IS APPROACHING THE AREA FROM THE NORTHWEST. I
HAVE KEPT SOME ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST AS
THE FRONT MOVES INTO THE AREA. CURRENTLY...THE ONLY UPSTREAM SHOWERS
ARE ON A TRAJECTORY TO MISS EASTERN KENTUCKY. MOST OF THE MODELS ARE
DEVELOPING PRECIPITATION OVER THE AREA. THE HRRR IS HINTING THAT THE
SHOWERS MAY DEVELOP AS THE FRONT INTERSECTS SOME OF THE OLD OUTFLOW
BOUNDARIES THAT WERE ALL OVER THE PLACE THIS EVENING. ONE OF THE
OUTFLOWS DIED ON A LINE FROM JOHNSON TO PULASKI COUNTIES. WILL HAVE
TO KEEP AN EYE ON THINGS TO SEE IF ANYTHING DEVELOPS. THE AIR MASS IN
FAIRLY UNSTABLE THIS EVENING...HOWEVER THE NAM BUFR IS SHOWING A MID
LEVEL CAP DEVELOPING AFTER MIDNIGHT. THIS MAY KEEP ANY SHOWERS THAT
DEVELOP FROM GROWING INTO THUNDERSTORMS. THE REST OF THE FORECAST IS
ON TRACK. WILL ISSUE NEW ZONES MOMENTARILY.
UPDATE...
ISSUED AT 705 PM EDT TUE JUL 31 2012
AN ACTIVE AREA OF THUNDERSTORMS HAS FLARED UP THIS AFTERNOON. SOME OF
STORMS OVER LETCHER COUNTY BECAME SEVERE AND PUT DOWN SOME ONE INCH
HAIL AND DOWNED SOME TREE. SOME OF THE STORMS HAVE BEEN
TRAINING...AND AS SUCH...SOME FLOODING POTENTIAL HAS BE REALIZED. A
FLASH FLOOD WARNING WAS ISSUED FOR PIKE COUNTY...PARTLY BECAUSE OF
SOME OF THE HEAVY RAIN OVER BUCHANAN COUNTY FLOWED INTO THE AREA AND
THEN HEAVY RAIN DEVELOPED OVER PIKE COUNTY AS WELL. SOMETIMES
RADAR RAINFALL AMOUNTS ARE A BIT DUBIOUS BECAUSE OF HAIL
CONTAMINATION...HOWEVER THE FLASH FLOOD GUIDANCE FOR THAT AREA BEEN
MORE THAN DOUBLED BY RADAR ESTIMATES. AS THE THUNDERSTORMS MOVE
SOUTHEAST OUT OF THE AREA BY 9 PM...ANOTHER AREA OF STORMS WILL BE
MOVING INTO THE BLUE GRASS FROM THE NORTHWEST LATER TONIGHT. THE REST
OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 335 PM EDT TUE JUL 31 2012
CONVECTION THAT WAS OVER SE COUNTIES HAS DIMINISHED...THOUGH CU
REMAINS IN PLACE ACROSS THE SOUTHEASTERN COUNTIES. UPPER LEVEL
RIDGING REMAINS IN PLACE NEAR THE TX AND OK PANHANDLE REGIONS AT MID
AFTERNOON WITH TROUGH GENERALLY FROM CENTRAL CANADA DOWN THROUGH THE
GREAT LAKES TO THE EASTERN SEABOARD. NW FLOW ALOFT IS IN PLACE
BETWEEN THE TWO SYSTEMS. A SHORTWAVE IN THIS NW FLOW IS CURRENTLY
MOVING THROUGH ONTARIO AND THE GREAT LAKES REGION AND IS APPROACHING
THE UPPER OH RIVER VALLEY. AN OUTFLOW BOUNDARY FROM OVERNIGHT
CONVECTION HAS LOST SOME DEFINITION...BUT IS PROBABLY STILL IN PLACE
TO THE NORTHWEST OF THE REGION IN NORTHERN KY. FURTHER TO THE
NORTHWEST A COLD FRONT ASSOCIATED WITH THE SHORTWAVE MOVING THROUGH
THE GREAT LAKES IS STARTING TO APPROACH THE OH VALLEY.
THE SHORTWAVE WILL PASS BY TO THE NORTH AND NORTHEAST OF THE AREA
LATE THIS EVENING AND OVERNIGHT ALTHOUGH MODELS HINT AT ANOTHER WEAK
SHORTWAVE POSSIBLY MOVING ACROSS THE REGION ON WED AS WELL. INSTABILITY
PARAMETERS SUGGEST THAT ISOLATED CONVECTION COULD STILL DEVELOP OVER
THE SOUTHEASTERN COUNTIES OVER THE NEXT FEW HOURS. RECENT UPPER LEVEL
RADAR SCANS SUGGEST SHOWERS TRYING TO DEVELOP OVER THE SOUTHEASTERN
COUNTIES. OTHERWISE...CONVECTION THAT IS FORECAST TO DEVELOP OUR NW
IN ADVANCE OF THE COLD FRONT AND POSSIBLE DEVELOPMENT ALONG THE OLD
OUTFLOW SHOULD AFFECT THE NORTHWEST OR NORTHERN SECTIONS DURING THE
EVENING AS THE SHORTWAVE MOVES BY TO THE NORTHEAST. MEANWHILE COLD
FRONT NOW NORTHEAST OF THE OH VALLEY WILL DROP DOWN INTO THE REGION
TONIGHT AND WILL BECOME RATHER DIFFUSE BY WED...BUT STILL MAY BE A
FOCUS FOR CONVECTION IN THE FAR EAST...ESPECIALLY WHEN COUPLED BY
THE POTENTIAL SHORTWAVE CROSSING THE REGION. SFC AND UPPER LEVEL HIGH
PRESSURE BUILDING INTO THE AREA SHOULD LEAD TO DRY WEATHER FOR WED NIGHT.
CONFIDENCE IN AREAL EXTENT AND TIMING OF CONVECTION FROM LATE THIS
AFTERNOON INTO EARLY IN THE EVENING IS NOT ALL THAT HIGH...BUT SAT
AND RADAR TRENDS AS WELL AS SOME OF THE GUIDANCE SUGGESTS MORE
ACTIVITY THROUGH EARLY EVENING IN THE SOUTHEAST. THIS MAY THEN BE
FOLLOWED BY ISOLATED TO PERHAPS SCATTERED CONVECTION DURING THE MID
TO LATE EVENING OR EVEN OVERNIGHT...ESPECIALLY IN THE NORTH.
PATCHY FOG MAY DEVELOP TOWARD DAWN WHERE ANY PRECIP FALLS THIS
EVENING OR OVERNIGHT...AND THEN MORE TYPICAL VALLEY FOG ON WED NIGHT
WITH HIGH PRESSURE IN PLACE.
TEMPERATURES THROUGH THE PERIOD WILL AVERAGE A FEW DEGREES ABOVE
NORMAL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 418 PM EDT TUE JUL 31 2012
WEAKENING SURFACE HIGH PRESSURE OVER THE REGION OVERLAID BY NW FLOW
ALOFT IS EXPECTED TO BRING DRY WX AND MAINLY CLEAR SKIES THURSDAY AND
THURSDAY NIGHT. AS THE HIGH CONTINUES TO WEAKEN...IT WILL LEAVE US IN
BETWEEN A LARGE SUBTROPICAL HIGH OVER THE ATLANTIC...AND LOW PRESSURE
OVER THE PLAINS WITH A COLD FRONT APPROACHING FROM THE NORTHERN
PLAINS. THE RESULTING WIND FLOW OVER THE LOCAL AREA WILL CARRY GULF
OF MEXICO MOISTURE NORTHWARD AGAIN...BRINGING INSTABILITY AND THE
POSSIBILITY OF SHOWERS AND THUNDERSTORMS. WILL USE ONLY 20-30 PERCENT
POP FRIDAY THROUGH SATURDAY NIGHT...DUE TO A LACK OF FEATURES AND LIGHT
FLOW ALOFT.
SUNDAY AND SUNDAY NIGHT AN UPPER TROUGH WILL MOVE ESE OVER THE GREAT
LAKES AND OHIO VALLEY...BRING THE AFOREMENTIONED SURFACE COLD FRONT
WITH IT. THE INCREASING FLOW ALOFT AND THE FOCUS FOR CONVECTIVE
INITIATION NEAR THE FRONT FRONT WILL PROVIDE A GREATER POP. THINK
THAT MOST PLACES WILL HAVE RAIN AT SOME POINT WITH THIS SYSTEM...BUT
HAVE USED 50 PERCENT FOR BOTH PERIODS FOR NOW. WANTED TO AVOID 60 YET
BECAUSE OF TIMING UNCERTAINTY AT THE EXTENDED TIME FRAME.
PRECIP COULD LINGER INTO MONDAY...ESPECIALLY IN THE SOUTHEAST...BUT
SHOULD END. DRY WEATHER AND SLIGHTLY LOWER HUMIDITY IS THEN EXPECTED
THROUGH TUESDAY AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE COLD
FRONT AND PASSES BY TO OUR NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 215 AM EDT WED AUG 1 2012
CONVECTION IS POPPING UP TO THE NORTHWEST OF PART OF THE FORECAST
AREA IN RELATION TO AN APPROACHING SFC BOUNDARY AND SOME ENERGY
ALOFT. HAVE PUSHED UP THE TIME OF THE VCSH IN THE EXISTING TAFS FOR
EARLY THIS MORNING. WILL HAVE TO MONITOR FOR A POSSIBLE VCTS AND CB
ADDITION AS THIS SCENARIO UNFOLDS OVER THE NEXT COUPLE OF HOURS. DO
EXPECT THE ACTIVITY TO SETTLE BY MID MORNING AND HAVE DROPPED ANY
MENTION OF PCPN BY THAT TIME. OTHERWISE...VFR CONDITIONS WILL
DOMINATE THROUGH THE PERIOD. DO STILL EXPECT TO SEE SOME PATCHY DENSE
VALLEY FOG LATE TONIGHT AND EARLY THIS MORNING...ESPECIALLY OVER
AREAS IN THE FAR SOUTHEAST THAT SAW THE RAIN YESTERDAY AFTERNOON...
BUT THE MAIN TAF SITES SHOULD REMAIN CLEAR. OUTSIDE OF ANY STRAY
THUNDERSTORMS...THE WINDS WILL BE LIGHT AND VARIABLE THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JP
LONG TERM....HAL
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1124 AM CDT WED AUG 1 2012
.DISCUSSION...
MOSTLY SUNNY WEST WITH LOWER 90S...TO PARTLY TO MOSTLY CLOUDY FOR
A SOME ZONE GROUPINGS NORTH AND EAST WITH MID TO UPPER 80S.
LOOKING UPSTREAM STILL SOME MORE CLOUDS TO FILTER DOWN ACROSS S AR
INTO N LA...SO HAVE EASED DOWN HIGH TEMPS A DEGREE OR FEW HERE AND
THERE...BUT NOTHING TOO DIFFERENT FROM HOT. THE HEAT ADVISORY
CONTINUES AREA WIDE WITH HX AROUND 105 OR MORE IN SPOTS. WE HAVE
PEARED BACK A BIT ON THE WESTERN EXTENT OF SLIGHT CHANCE FOR REST
OF TODAY...AND IT WAS LEANING THAT WAY ALREADY...THIS JUST MAKES
FOR LESS WORDING AS THE TEXT FORECAST TRANSITIONS FROM MORNING TO
AFTERNOON WORDING. THE LATEST RAP AND NAM MODELS SHOWING NO QPF
FOR THE CWA...BUT GFS AND EURO BOTH CONSENTED TO A SLIGHT CHANCE
EARLIER. ONE THING IS FOR SURE THE RAINFALL OF CHANCE FOR ANYWAY IS
GETTING CLOSER AS THE UPPER RIDGE IS ALL BUT SHUNTED WEST OF THE
MISSISSIPPI RIVER LOOKING AT THE LATEST WATER VAPOR IMAGERY. /24/
&&
.AVIATION...
VFR CONDITIONS EXPECTED THIS AFTERNOON AND TONIGHT ACROSS THE AREA.
TERMINALS HAVE MAINTAINED VFR STATUS THIS MORNING...WITH ONLY KLFK
BRIEFLY DROPPING TO MVFR AS SOME LOW CLOUDS BRIEFLY PASSED OVER.
WINDS WILL BE PRIMARILY OUT OF THE SOUTH TODAY...IN THE 5 TO 10 KNOT
RANGE WITH A FEW HIGHER GUSTS POSSIBLE. A FEW THUNDERSTORMS MAY BE
POSSIBLE FROM KELD TO KMLU THIS AFTERNOON. WITH CONFIDENCE NOT VERY
HIGH IN COVERAGE...HAVE ADDED VCTS TO WORDING. OTHERWISE...SCATTERED
AFTERNOON CU WILL DEVELOP IN THE 5KFT RANGE. /20/
&&
.PREV DISCUSSION... /ISSUED 713 AM CDT WED AUG 1 2012/
DISCUSSION...
A FEW SHOWERS HAVE DEVELOPED AND MOVED INTO SE OK/SW AR. PRODUCTS
ARE ALREADY OUT ON A QUICK UPDATE TO EXTEND 20 POPS FURTHER WWD
TODAY TO COVER THE ONGOING SHOWERS. /12/
PREV DISCUSSION... /ISSUED 349 AM CDT WED AUG 1 2012/
DISCUSSION...
ANOTHER HOT ONE IS ON TAP FOR TODAY...AS THE UPPER RIDGE CONTINUES
TO HOLD STRONG OVER NRN TX. MODELS INDICATE SOME WEAKNESS ALONG
THE ERN PERIPHERY...WHICH MAY BRING SOME CONVECTION ACROSS N LA/SW
AR TODAY. HAVE KEPT THE CURRENT HEAT ADVISORY IN TACT ACROSS THE
ENTIRE REGION...AS HEAT INDICES LOOK TO RUN 103-108 AREAWIDE. WE
MAY SEE SOME ISOLATED 110-112 HEAT INDICES ACROSS THE E...BUT WILL
NOT GO WITH THE EXCESSIVE HEAT WARNING DUE TO THE ANTICIPATED
SHORT DURATION AND ISOLATED NATURE. MIXING MAY KEEP A FEW SITES IN
THE W FROM REACHING THE 105 DEGREE THRESHOLD...BUT AGAIN...THIS
SHOULD BE VERY ISOLATED AND DOESN`T WARRANT KEEPING THESE AREAS
OUT OF THE ADVISORY. THU IS ALSO SHAPING UP TO BE SIMILAR TO
TODAY...SO HAVE EXTENDED THE HEAT ADVISORY ONE MORE DAY.
CONTINUED WEAKNESS ON THE ERN SIDE OF THE RIDGE WILL KEEP SLIGHT
CHANCE POPS IN THROUGH THE REMAINDER OF THE WORK WEEK AND INTO THE
WEEKEND. A WEAK COLD FRONT ASSOCIATED WITH A TROF OVER THE GREAT
LAKES REGION IS FCST TO BEGIN BACK-DOORING INTO THE REGION BY
SUNDAY...ADDING RAIN CHANCES FOR THE ENTIRE REGION...AND ALSO
BREAKING THE HEAT TO SOME EXTENT. THE PRESENCE OF THE BOUNDARY
WILL KEEP THOSE RAIN CHANCES IN FOR THE REMAINDER OF THE PD...AND
KEEP TEMPS CLOSER TO NORMAL. /12/
AVIATION...
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE NEXT 24 HOURS.
ISOLATED CONVECTION MAY DEVELOP MID TO LATE AFTERNOON ACROSS SOUTH
CENTRAL ARKANSAS INTO NORTH CENTRAL LOUISIANA...BUT COVERAGE TOO
SMALL TO MENTION IN KELD OR KMLU TERMINAL FORECAST AT THIS TIME.
SURFACE WIND ACROSS THE REGION MOSTLY SOUTH TO SOUTHWEST 5 TO 10
KTS. /14/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 101 77 100 78 100 / 20 10 10 10 10
MLU 100 80 100 78 99 / 20 20 20 20 20
DEQ 101 72 102 73 102 / 20 10 10 10 10
TXK 101 78 101 77 101 / 20 10 10 10 10
ELD 98 78 100 76 99 / 20 20 20 20 20
TYR 102 78 102 79 100 / 10 10 10 10 10
GGG 102 77 101 78 101 / 10 10 10 10 10
LFK 99 76 99 76 98 / 10 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR THE FOLLOWING ZONES:
ARZ050-051-059>061-070>073.
LA...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR THE FOLLOWING ZONES:
LAZ001>006-010>014-017>022.
OK...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR THE FOLLOWING ZONES:
OKZ077.
TX...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR THE FOLLOWING ZONES:
TXZ096-097-108>112-124>126-136>138-149>153-165>167.
&&
$$
24/20
AREA FORECAST DISCUSSION
NWS CARIBOU ME
834 AM EDT WED AUG 1 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK ACROSS THE GULF OF MAINE EARLY TODAY. A
COLD FRONT APPROACHING FROM THE WEST AND NORTHWEST WEAKEN AS IT
CROSSES THE AREA TONIGHT. ANOTHER COLD FRONT WILL CROSS THE AREA
ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: UPDATED THE POPS AND SKY TO BRING PERCENTAGES UP AND
INCREASE THE AREAL EXTENT FURTHER NNE PER THE LATEST RADAR AND
VISIBLE SATL IMAGERY. HRRR AND RAP MODEL BOTH SHOW NORTHERN EXTENT
OF RAINFALL MAKING ITS WAY INTO PRESQUE ISLE AND HOULTON AFTER
12Z. THE NAM/GFS/CANADIAN REGIONAL ALL SHOW PRECIP TOO FAR SOUTH
AND EAST. THE 00Z ECMWF LINES A BIT BETTER W/THE HRRR AND RAP.
DECIDED TO LEAN TOWARD THE HRRR W/TH ECMWF BLENDED IN AND RE-
ADJUSTED THE POPS WHICH SHOW 60-80% POPS ACROSS THE HOULTON-
MILLINOCKET REGIONS AND 20-30% FOR THE CARIBOU-PRESQUE ISLE
AREAS. FURTHER NORTH AND WEST, A DRY DAY IN STORE. STRATUS WILL
HOLD ON LONGER AS WELL W/DEFINED CLEAR ZONE ACROSS THE WEST-NORTHWEST.
CLEARING WILL TAKE PLACE THIS AFTERNOON ACROSS THE EASTERN 1/2 OF THE
CWA W/RAIN ENDING.
PREVIOUS DISCUSSION...
WELL-DEFINED...COMPACT SFC LOW PRES CNTRD E OF BOS ATTM AND CONTS
TO LIFT RATHER QUICKLY NE. EXPECT RAIN CONT TO SPREAD NEWRD
AFFECTING MOST OF SRN AND SERN AREAS W/THE NRN EDGE OF THE SHIELD
REACHING E CENTRAL AREAS...PSBLY AS FAR N AS KHUL BY MID AM BEFORE
THE ENTIRE AREAS SHIFTS E OF THE FA BY LATE AM/ERLY AFTN. THIS
GENERAL AREA OF RAIN WILL LIKELY DROP .25-.50 INCHES ACROSS MOST
OF OUR SRN/SERN AREAS.
OTHRWS...A WEAKENING COLD FRONT APPROACHING FROM THE W AND NW WILL
LIKELY BE CLOSE ENUF TO TRIGGER SOME AFTN SHOWERS AND PSBL THUNDER
MAINLY ACROSS OUR WRN/NWRN AREAS W/ SOME ISOLATED ACTIVITY REACHING
CENTRAL AND PSBLY EVN ERN AREAS TNGT AS THIS FRONT DISSIPATES
ACROSS THE REGION.
CLOUDS...SOME PRECIP AND A BRIEF WEAK NRLY FLOW BEHIND THE
DEPARTING SFC LOW WILL LIKELY RESULT IN COOLER TEMPS ACROSS THE
REGION TDY W/ LOW TNGT PRETTY SIMILAR TO THE LAST FEW NGTS...
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
WARM...HUMID CONDITIONS ARE EXPECTED ON THURSDAY IN ADVANCE OF A
COLD FRONT APPROACHING FROM THE WEST. IMPULSES MOVING THROUGH THE
WEST TO SOUTHWEST FLOW ALOFT WILL BRING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS ESPECIALLY DURING THE AFTERNOON HOURS. THURSDAY
NIGHT SHOULD BE MAINLY DRY ALTHOUGH COULDNT RULE OUT A FEW SHOWERS
ACROSS NORTHWEST MAINE AS THE COLD FRONT APPROACHES. THE COLD
FRONT WILL CROSS THE REGION ON FRIDAY WITH THE CHANCE FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY ACROSS DOWNEAST AREAS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FRIDAY NIGHT AND
SATURDAY AS FRONTAL BOUNDARY REMAINS JUST TO OUR SOUTH. THE FRONT
WILL PUSH BACK TO OUR NORTH SATURDAY NIGHT AND EARLY SUNDAY WITH
WARM AND HUMID CONDITIONS EXPECTED. A COLD FRONT WILL CROSS THE
REGION ON MONDAY WITH THE CHANCE FOR SHOWERS. DRIER WEATHER SHOULD
RETURN FOR TUESDAY.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: IFR CONDS EXPECTED AT KBHB AND KBGR INTO THIS AM IN
RAIN AND STRATUS W/ CONDS IMPRVG TO VFR BY MID-LATE AM. IFR IN
AREAS OF FOG RETURNS AT OUR SRN TAF SITES LATER THIS EVE AND
OVERNIGHT. MAINLY VFR CONDS EXPECTED AT THE REMAINING TAF SITES THO
EXPECT SOME PSBL MVFR AT KHUL ERLY THIS AM AND PSBL MVFR/IFR IN
PATCHY FOG LATER TNGT...
SHORT TERM: MAINLY VFR EXCEPT THE CHANCE FOR MVFR/IFR IN ANY SCT
SHOWERS AND TSTMS AND PATCHY MORNING FOG.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THRU TONIGHT. VISIBILITIES WILL BE REDUCED IN
RAIN AND PATCHY FOG THIS MORNING AND IN AREAS OF FOG TNGT.
SHORT TERM: WIND/SEAS SHOULD REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT/KHW
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/KHW
MARINE...HEWITT/KHW/DUDA
AREA FORECAST DISCUSSION
NWS GRAY ME
1220 AM EDT WED AUG 1 2012
.SYNOPSIS...
MID ATLANTIC LOW PRESSURE WILL MOVE ALONG THE NEW ENGLAND COAST
OVERNIGHT AND INTO THE CANADIAN MARITIMES WEDNESDAY. A WEAK COLD
FRONT WILL MOVE INTO THE REGION FROM THE WEST ON FRIDAY AND BECOME
STATIONARY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...
HAVE UPDATED GRIDS BASED ON LATEST (DUAL POL) RADAR TRENDS AND
MOST RECENT SFC ANALYSIS. COASTAL LOW NOW WRAPPING BANDS OF RAIN
BACK TO THE COAST. HAVE RAISED POPS SIGNIFICANTLY FOR THIS REGION
AND PLACED LOCALLY UP TO A HALF INCH OF RAIN OVER THE NEXT FEW
HOURS IN THE REGION FOR QPF. PCPN SHOULD BEGIN TO WIND DOWN AROUND
SUNRISE AS LOW QUICKLY PULLS THROUGH THE GULF OF MAINE.
ONLY MINOR MODIFICATIONS TO THE REMAINDER OF THE GRIDS.
PREV DISC...
CUMULUS FIELD AND ISOLATED SHOWERS HAVE NOW
DEVELOPED OVER COOS COUNTY. THE HRRR MODEL INDICATES A FEW SHOWERS
AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER
TERRAIN FOR THE REMAINDER OF THE AFTERNOON.
NORTHERN NEW ENGLAND IS CAUGHT IN BETWEEN TWO SYSTEMS...ONE
LOCATED TO OUR WEST AND THE OTHER TO OUR SOUTH. A COASTAL LOW
PRESSURE SYSTEM WAS DEEPENING NEAR LONG ISLAND THIS AFTERNOON AND
WILL MOVE ALONG THE NEW ENGLAND COASTLINE OVERNIGHT. MODELS ARE IN
BETTER AGREEMENT THAT COASTAL AREAS AND AREAS AS FAR INLAND AS THE
FOOTHILLS WILL SEE PRECIPITATION OVERNIGHT. THE MIDCOAST AREA AS
WELL AS THE ISLANDS LOOK TO RECEIVE THE HIGHEST QPF AMOUNTS.
CURRENTLY DO NOT EXPECT THUNDERSTORMS...BUT THERE COULD BE A FEW
STRIKES OFFSHORE CLOSER TO THE CORE OF THE SYSTEM. WIDESPREAD FOG
AND CLOUDY CONDITIONS WILL KEEP TEMPERATURES ON THE WARM SIDE
OVERNIGHT.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
THE COASTAL LOW WILL BE JUST OFFSHORE TOMORROW MORNING AND WILL
MOVE INTO THE CANADIAN MARITIMES BY EARLY AFTERNOON. AS SHOWERS
END OVER THE MIDCOAST REGION (ASSOCIATED WITH THE COASTAL LOW)
THEY WILL BEGIN TO CREEP INTO NEW HAMPSHIRE AND WESTERN MAINE
AHEAD OF THE COLD FRONT.
PW VALUES INCREASE TO NEAR 1.75 INCHES INDICATING POOLING MOISTURE
AHEAD OF THE APPROACHING COLD FRONT TO OUR WEST. FORECAST SKEW T
PROFILES SHOW SKINNY CAPE...WARM CLOUD LAYERS...AND VERY LIGHT
WINDS. THIS ALL POINTS TOWARDS POSSIBLE FLASH FLOODING PROBLEMS.
INSTABILITY WILL BE HIGH ENOUGH FOR SCATTERED THUNDERSTORMS.
HIGH TEMPERATURES SHOULD REACH THE UPPER 70S/LOWER 80S TOMORROW
WITH LOW TEMPERATURES IN THE UPPER 50S TO MID 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
COLD FRONT STALLS IN THE NORTHWESTERN PART OF THE AREA ON
THURSDAY... A SECOND AREA OF LOW PRESSURE PASSES OFFSHORE OF CAPE
COD DURING THE DAY. MOST OF THE RAIN WITH THIS LOW WILL STAY
OFFSHORE... BUT INSTABILITY AND LIFT ASSOCIATED WITH THE
DISSIPATING COLD FRONT AND A PASSING UPPER LEVEL SHORTWAVE TROUGH
MAY LEAD TO A FEW SHOWERS OR THUNDERSTORMS IN INLAND AREAS.
AS THE UPPER LEVEL TROUGH PUSHES EAST... A COLD FRONT WILL PUSH
SOUTHWARD INTO NORTHERN NEW ENGLAND ON FRIDAY... WITH SHOWERS AND
THUNDERSTORMS POSSIBLE ALONG AND AHEAD OF IT. THE FRONT STALLS AS
IT GETS CLOSER TO THE COAST ON SATURDAY AND WEAKENS.
LARGER TROUGH ALOFT PUSHES EASTWARD OUT OF THE GREAT LAKES SUNDAY
INTO MONDAY... WITH LIFT AHEAD OF THIS SYSTEM PROVIDING INCREASED
CHANCES FOR SHOWERS AND THUNDERSTORMS. THUNDERSTORMS WILL BE MOST
LIKELY ON MONDAY AHEAD OF A MORE PRONOUNCED COLD FRONT.
TEMPERATURES THROUGH THE PERIOD WILL REMAIN ABOVE NORMAL AS THE
JET STREAM STAYS NORTH AND WARM... MOIST AIR CONTINUES TO FLOW
INTO NEW ENGLAND.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...GUSTY SOUTHERLY WINDS THIS AFTERNOON WITH VFR
CONDITIONS CONTINUING. LOWERING CEILINGS AND VISIBILITIES WILL
ARRIVE AS LOW PRESSURE MOVES ALONG THE NEW ENGLAND COASTLINE
TONIGHT. LIFR/IFR CONDITIONS LIKELY AT ALL TERMINALS JUST PRIOR TO
MIDNIGHT WITH SHOWERS EVERYWHERE EXCEPT KHIE...KLEB...AND KCON.
LONG TERM...GENERALLY VFR EXPECTED... BUT WITH INCREASING MOISTURE
LEVELS INTO THE WEEKEND... NOCTURNAL FOG WILL BECOME MORE AND MORE
LIKELY ESPECIALLY IN TRADITIONALLY FAVORED AREAS LIKE WHITEFIELD
AND LEBANON.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL FALL JUST SHORT OF SMALL CRAFT
THRESHOLDS LATE TONIGHT INTO WEDNESDAY AS LOW PRESSURE CROSSES
THE GULF OF MAINE.
LONG TERM...LOW PRESSURE PASSES EAST OF CAPE COD AND INTO NOVA
SCOTIA AGAIN ON THURSDAY. BUT WINDS SHOULD STAY BELOW 20 KT. HIGH
PRESSURE OVER THE ATLANTIC BRINGS A LIGHT SOUTHERLY FLOW THROUGH
THE WEEKEND.
&&
.EQUIPMENT...
THE DUAL POLARIZATION RADAR INSTALLATION AT THE NATIONAL
WEATHER SERVICE SITE IN GRAY MAINE IS IN PROGRESS. GRAY MAINE
/KGYX/ RADAR DATA WILL NOT BE AVAILABLE FOR ANOTHER DAY OR TWO
DURING THE INSTALLATION AND FOLLOW UP TESTING OF THIS NEW
EQUIPMENT.
STILL MISSING OBSERVATIONS. ISSUE IS BEING WORKED ON ATTM.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
317 PM EDT WED AUG 1 2012
.SYNOPSIS...
EXPECT ANY REMAINING THUNDERSTORMS TO END EARLY TONIGHT. HIGH
PRESSURE WILL PROVIDE DRY AND VERY WARM CONDITIONS THURSDAY AND
FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
RECENT SURFACE AND RADAR DATA SHOW SCATTERED THUNDERSTORMS ACROSS
THE APPALACHIAN MOUNTAINS, AND NO MORE THAN ISOLATED STORMS ELSEWHERE.
PER RECENT HRRR MODEL OUTPUT, EXPECT THIS WILL BE THE TREND INTO
EARLY EVENING.
FOR THE REST OF THE NIGHT, NOCTURNAL COOLING AND THE UPPER TROUGH
EXITING EAST WILL STABILIZE CONDITIONS. NAM MODEL PROFILES SHOW A
STRONG, SHALLOW SURFACE TEMPERATURE, WHICH CAN RESULT IN PATCHY
FOG, PERHAPS MORE WIDESPREAD IN THE RIVER VALLEYS.
FORECASTED TEMPERATURES, USING RECENT GFS AND NAM MOS, THAT
PROJECTED LOWS TONIGHT TO BE NEAR NORMAL, AS SURFACE DEW POINTS
ALSO LOWER TO NEAR NORMAL VALUES. HIGHS THURSDAY AFTERNOON CAN BE
5 DEGREES WARMER THAN NORMAL, WHILE SURFACE DEW POINTS WILL REMAIN
CLOSE TO NORMAL.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
SREF MODEL OUTPUT CONTINUES TO SHOW HIGH PRESSURE WILL BRING DRY
WEATHER FOR THURSDAY AND FRIDAY.
FORECASTED TEMPERATURES TO BE WARMER THAN NORMAL, WITH AFTERNOON
HIGHS THURSDAY WELL INTO THE 80S AND HIGHS FRIDAY IN THE LOWER 90S
ACROSS LOWER ELEVATIONS. EARLY MORNING LOWS WILL BE SLIGHTLY
WARMER THAN NORMAL, AS SOUTHERLY WINDS BRING INCREASING HUMIDITY
AS INDICATED BY SURFACE DEW POINTS IN THE MID TO UPPER 60S BY
FRIDAY.
AS THE NEXT EASTBOUND CANADIAN LOW PRESSURE SYSTEM NEARS THE GREAT
LAKES SATURDAY, HAVE CONTINUED A CHANCE OF THUNDERSTORMS SATURDAY.
INCREASED CLOUDS MAY RESTRICT AFTERNOON HIGH TEMPERATURES FROM
BEING AS WARM AS FRIDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONSENSUS OF MODELS SHOWS A CLOSED UPPER LOW AND SURFACE LOW
TRACKING NORTH OF THE GREAT LAKES INTO SOUTHERN QUEBEC BY MONDAY.
INSTABILITY WILL BE INCREASED AS ALREADY HUMID CONDITIONS WILL BE
FURTHER AUGMENTED BY LOW LEVEL SOUTHERLY WINDS PROVIDING AN
ADDITIONAL INFLUX OF GULF MOISTURE. SO EXPECT SCATTERED
THUNDERSTORMS TO CONTINUE ACROSS THE UPPER OHIO VALLEY THROUGH EARLY
MONDAY.
SPC HAS INDICATED SOME POTENTIAL FOR SEVERE STORMS SUNDAY DUE TO
INCREASED VERTICAL SHEAR.
SURFACE HIGH PRESSURE IS PROGGED TO BUILD IN AND PROVIDE DRY AND
STABLE CONDITIONS TUESDAY AND WEDNESDAY.
FORECAST TEMPERATURES WILL REMAIN AT LEAST SLIGHTLY WARMER THAN
NORMAL BASED ON BLEND OF RECENT GFS AND ECMWF MOS AND NAEFS MEDIAN
VALUES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
EXPECT MAINLY VFR INTO EARLY TONIGHT, ALTHOUGH ISOLATED
THUNDERSTORMS MAY CAUSE BRIEF RESTRICTIONS. NO MENTION WAS INCLUDED
IN TAFS AS CONFIDENCE OF OCCURRENCE REMAINS LOW FOR ANY GIVEN
LOCATION.
EXPECT AREAS OF IFR FOG DEVELOP LATE TONIGHT MAINLY AFTER 08Z AS
SURFACE INVERSION SETS UP WITH LIGHT SURFACE WINDS. FOG SHOULD
QUICKLY BURN OFF WITH STRONG SUN THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
EXPECT VFR AND GENERALLY DRY CONDITIONS FOR THURSDAY NIGHT AND
FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN WITH THUNDERSTORMS
SATURDAY AND SUNDAY...AS ANOTHER LOW PRESSURE SYSTEM MOVES ACROSS THE
GREAT LAKES INTO SOUTHERN QUEBEC AND PUSHES A COLD FRONT THROUGH THE
REGION. SURFACE HIGH PRESSURE SHOULD BRING IMPROVEMENT TO VFR MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
252 PM EDT WED AUG 1 2012
.SYNOPSIS...
A PASSING WEAK UPPER LEVEL DISTURBANCE WILL SUPPORT THUNDERSTORM
CHANCES THROUGH EARLY EVENING. HIGH PRESSURE WILL BRING DRY AND
VERY WARM CONDITIONS THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RECENT SURFACE AND RADAR DATA SHOW SCATTERED THUNDERSTORMS ACROSS
THE APPALACHIAN MOUNTAINS, AND NO MORE THAN ISOLATED ELSEWHERE.
PER RECENT HRRR MODEL OUTPUT, EXPECT THIS WILL BE THE TREND INTO
EARLY EVENING.
FOR THE REST OF THEN NIGHT, NOCTURNAL COOLING AND THE UPPER
TROUGH EXITING EAST WILL STABILIZE CONDITIONS. NAM MODEL PROFILES
SHOW A STRONG, SHALLOW SURFACE TEMPERATURE, WHICH CAN RESULT IN
PATCHY FOG, PERHAPS MORE WIDESPREAD IN THE RIVER VALLEYS.
FORECASTED TEMPERATURES TO AGAIN BE SLIGHTLY WARMER THAN NORMAL,
BASED ON RECENT GFS AND NAM MOS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
HIGH PRESSURE WILL BRING DRY WEATHER AND FOR THURSDAY AND FRIDAY.
FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL, WITH AFTERNOON
HIGHS THURSDAY AND FRIDAY WELL INTO THE 80S. EARLY MORNING LOWS WILL
BE SLIGHTLY WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
CONTINUED HUMID AND VERY WARM CONDITIONS WILL EVOLVE INTO UNSETTLED
CONDITIONS THIS PERIOD.
CONSENSUS OF MODELS SHOW A STRONG UPPER LEVEL TROUGH AND CLOSED
SURFACE LOW TRACKING, EAST ALONG THE CANADIAN BORDER THIS WEEKEND
THAT WILL PASS EASTWARD THROUGH THE EASTERN GREAT LAKES MONDAY.
INSTABILITY WILL BE INCREASED AS ALREADY HUMID CONDITIONS WILL BE
FURTHER AUGMENTED BY LOW LEVEL SOUTHERLY WINDS PROVIDING AN
ADDITIONAL INFLUX OF GULF MOISTURE. SO EXPECT A DECENT CHANCE OF
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY THIS WEEKEND.
SURFACE HIGH PRESSURE IS PROGGED TO PROVIDE DRY, STABLE CONDITIONS
TUESDAY.
FORECAST TEMPERATURES TO CONTINUE AT LEAST SLIGHTLY WARMER THAN
NORMAL BASED ON BLEND OF RECENT GFS AND ECMWF MOS AND NAEFS MEDIAN
VALUES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
EXPECT MAINLY VFR INTO EARLY TONIGHT, ALTHOUGH ISOLATED
THUNDERSTORMS MAY CAUSE BRIEF RESTRICTIONS. NO MENTION WAS INCLUDED
IN TAFS AS CONFIDENCE OF OCCURRENCE REMAINS LOW FOR ANY GIVEN
LOCATION.
EXPECT AREAS OF IFR FOG DEVELOP LATE TONIGHT MAINLY AFTER 08Z AS
SURFACE INVERSION SETS UP WITH LIGHT SURFACE WINDS. FOG SHOULD
QUICKLY BURN OFF WITH STRONG SUN THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
EXPECT VFR AND GENERALLY DRY CONDITIONS FOR THURSDAY NIGHT AND
FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN WITH THUNDERSTORMS
SATURDAY AND SUNDAY...AS ANOTHER LOW PRESSURE SYSTEM MOVES ACROSS THE
GREAT LAKES INTO SOUTHERN QUEBEC AND PUSHES A COLD FRONT THROUGH THE
REGION. SURFACE HIGH PRESSURE SHOULD BRING IMPROVEMENT TO VFR MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
956 AM EDT WED AUG 1 2012
.SYNOPSIS...
INCREASED HUMIDITY AND A WEAK UPPER LEVEL DISTURBANCE WILL SUPPORT
SHOWER AND THUNDERSTORM CHANCES TODAY. HIGH PRESSURE WILL BRING
DRY WEATHER THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT HRRR MODEL OUTPUT CONTINUES TO SHOW THAT SCATTERED THUNDERSTORMS
CAN DEVELOP THIS AFTERNOON INTO EARLY EVENING, AHEAD OF A SLOWLY
MOVING EASTBOUND WEAK UPPER LEVEL SHORT WAVE TROUGH.
NOCTURNAL COOLING AND THE TROUGHS EXIT EAST WILL STABILIZE
CONDITIONS TONIGHT.
FORECASTED TEMPERATURES TO AGAIN BE SLIGHTLY WARMER THAN NORMAL,
BASED ON RECENT GFS AND NAM MOS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BRING DRY WEATHER AND FOR THURSDAY AND FRIDAY.
FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL, WITH AFTERNOON
HIGHS THURSDAY AND FRIDAY WELL INTO THE 80S. EARLY MORNING LOWS WILL
BE SLIGHTLY WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
CONTINUED HUMID AND VERY WARM CONDITIONS WILL EVOLVE INTO UNSETTLED
CONDITIONS THIS PERIOD.
CONSENSUS OF MODELS SHOW A STRONG UPPER LEVEL TROUGH AND CLOSED
SURFACE LOW TRACKING, EAST ALONG THE CANADIAN BORDER THIS WEEKEND
THAT WILL PASS EASTWARD THROUGH THE EASTERN GREAT LAKES MONDAY.
INSTABILITY WILL BE INCREASED AS ALREADY HUMID CONDITIONS WILL BE
FURTHER AUGMENTED BY LOW LEVEL SOUTHERLY WINDS PROVIDING AN
ADDITIONAL INFLUX OF GULF MOISTURE. SO EXPECT A DECENT CHANCE OF
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY THIS WEEKEND.
SURFACE HIGH PRESSURE IS PROGGED TO PROVIDE DRY, STABLE CONDITIONS
TUESDAY.
FORECAST TEMPERATURES TO CONTINUE AT LEAST SLIGHTLY WARMER THAN
NORMAL BASED ON BLEND OF RECENT GFS AND ECMWF MOS AND NAEFS MEDIAN
VALUES.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR INTO TONIGHT, ALTHOUGH SCATTERED THUNDERSTORMS
MAY CAUSE BRIEF RESTRICTIONS. THESE WERE NOT INCLUDED IN TAF AS
NOT CONFIDENT TO PINPOINT FOR ANY LOCATION.
DID INCLUDE MVFR RESTRICTIONS FOR FOG DEVELOPMENT LATE TONIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...
EXPECT VFR AND GENERALLY DRY CONDITIONS FOR THURSDAY AND FRIDAY.
RESTRICTIONS WILL BE POSSIBLE AGAIN WITH THUNDERSTORMS SATURDAY
AND SUNDAY...AS ANOTHER LOW PRESSURE SYSTEM MOVES INTO THE GREAT
LAKES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
154 AM EDT WED AUG 1 2012
.SYNOPSIS...
LOW PRESSURE ALOFT AND A WARM AND HUMID AIRMASS WILL PERSIST
ALONG THE EASTERN SEABOARD THIS WEEK. A WEAK COLD FRONT WILL
APPROACH THE MID-ATLANTIC REGION ON WEDNESDAY. A SECOND FRONTAL
BOUNDARY IS EXPECTED TO CROSS THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
BROKEN LINE OF THUNDERSTORMS CONTINUE TO DROP SOUTHEAST THROUGH
CENTRAL VIRGINIA. MUCAPE OVER EASTERN LWX CWA IS STILL 1500 TO
2000 J/KG ACCORDING TO RAP MODEL ON SPC MESO PAGE. STRATIFORM
APPROACHING DC MAY BE ALL THE METRO AREA GETS. HOWEVER...THE
SCATTERED THUNDERSTORMS THAT DEVELOPED OVER THE PAST HALF HOUR
EAST OF BALTIMORE IS INDICATIVE OF THE REMNANT INSTABILITY.
THROUGH THE MIDNIGHT HOUR ACTIVITY IS THE MAIN FEATURE
TONIGHT...WITH ONLY ISOLATED ACTIVITY AT BEST AFTERWARDS. EXPECT
AT LEAST PATCHY FOG IN THE WAKE OF THE THUNDERSTORMS.
WITH STAGNANT AMS...CU FIELD SHOULD DVLP QUICKLY AGAIN WED MRNG.
SHWRS AND TSTMS ONCE AGAIN CAN BE XPCD DURG THE DAY ON WED WITH
TROF RMNG ALONG APLCNS AND WEAK CDFNT APRCHG RGN. THERE IS SOME
UNCERTAINTY AS TO THE SWD ADVCMT OF THE BNDRY DURG THE DAY...SO
POPS WERE FOCUSED IN NWRN PORTION OF FCST AREA. MAXIMA IN MID-UPR
80S XPCD.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
UPPER-LEVEL AND SFC TROUGH WILL MOVE OFFSHORE THU...ALLOWING THE
MID-ATLC TO DRY OUT FOR A COUPLE OF DAYS. OUTSIDE OF A WEAK SFC
TROUGH THAT WILL DRIFT OVER THE AREA LATE THU INTO FRI...THE AREA
SHOULD BE FAIRLY QUIET. THIS WILL ALLOW FOR A BIT OF A WARM-UP
BOTH DAYS... ESPECIALLY FRI. HUMIDITY VALUES WILL NOT CHALLENGE
SOME OF THE HOTTER VALUES THIS YEAR...BUT TEMPS AND HEAT INDICES
WILL APPROACH THE M90S EACH AFTN.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE MAIN STORY FOR NEXT WEEKEND WILL BE THE BUILD-UP TO A FRONTAL
PASSAGE ON MONDAY. A POTENT LOW PRESSURE SYSTEM WILL SWING DOWN FROM
THE CANADIAN ROCKIES LATE THIS WEEK...DRAGGING ALONG THE US/CANADA
BORDER THIS WEEKEND. AS THE SYSTEM APPROACHES...A LARGE BERMUDA HIGH
WILL CREATE A FETCH OF WARM-MOIST AIR UP THE EASTERN SEABOARD BOTH
SAT AND SUN. SHOWERS AND TSTMS OF AN ISOLATED NATURE WILL BE
POSSIBLE EACH DAY THIS WEEKEND...ALONG WITH HIGHS IN THE L90S HIGHER
HUMIDITY THAN IN PAST DAYS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MVFR LEVELS ARE POSSIBLE OVERNIGHT AT CHO AND MRB AS THE AIR REMAINS
SATURATED AFTER EVENING SHOWERS/TSTORMS. WITH OVC TO BKN CLOUD COVER
OVER THE AREA...EXPECT COOLING TO BE GRADUAL AND ONLY MVFR
REDUCTIONS IN VSBY. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THROUGH THE DAY TOMORROW WILL REDUCE VSBY TO IFR LEVELS AT TIMES
ACROSS AREA TERMINALS. PRECIP SHOULD END WED AFTERNOON WITH SKIES
BEGINNING TO CLEAR. WIND WILL REMAIN LIGHT OVERALL EXCEPT FOR
OCCASIONAL 7KT GUSTS DEVELOPING FROM THE SOUTH WED AFTERNOON.
THESE GUSTS WILL DIMINISH INTO THE EVENING HOURS.
A COUPLE OF DRY DAYS TO CLOSE OUT THE WORK WEEK...AS HIGH PRESSURE
BRIEFLY BUILDS IN ACROSS THE REGION. THE WEEKEND WILL SEE THE RETURN
OF MOISTURE AND CUMULUS FIELD...ALONG WITH ISOLATED TSTMS. A LOW
PRESSURE SYSTEM APPROACHES FROM THE GREAT LAKES THIS WEEKEND...
DRAGGING A COLD FRONT ACROSS THE AREA ON MONDAY.
&&
.MARINE...
ISOLATED THUNDERSTORMS EXPECTED ACROSS THE WATERS THROUGH 2AM.
ADDITIONAL SPECIAL MARINE WARNINGS ARE POSSIBLE. SLY FLOW WILL
CONTINUE TO GUST AROUND 15 KT THROUGH WEDNESDAY.
GENERALLY LIGHT SLY WINDS LATE THIS WEEK INTO THE WEEKEND...THOUGH
SLY CHANNELING WILL OCCUR EACH AFTN/EVE. A COLD FRONT WILL THEN
MOVE ACROSS THE AREA LATE MON INTO TUE OF NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
ISSUED A COASTAL FLOOD ADVISORY FOR ANNAPOLIS AND ALEXANDRIA. WATER
LEVELS ARE AROUND THREE QUARTERS OF A FOOT ABOVE PREDICTED LEVELS
TONIGHT IN THIS WAXING GIBBOUS MOON PHASE. THE MOST SENSITIVE
LOCATIONS OF ALEXANDRIA AND ANNAPOLIS WILL PROBABLY HIT THEIR
MINOR THRESHOLDS OVER THE NEXT COUPLE OF HOURS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ014.
VA...COASTAL FLOOD ADVISORY FROM 6 AM TO 10 AM EDT THIS MORNING FOR
VAZ054.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...JACKSON/CLS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
128 PM EDT WED AUG 1 2012
.SYNOPSIS...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL DRIFT THROUGH THE GREAT LAKES REGION TODAY...
BRINGING SEASONABLY WARM AND DRY CONDITIONS. MEANWHILE...THE NEXT
LOW PRESSURE SYSTEM AND COOL FRONT...WILL MIGRATE ALONG THE CANADIAN
BORDER. THIS LOW WILL MOVE THROUGH TONIGHT...WITH ITS TRAILING COOL
FRONT SLIDING THROUGH THURSDAY. SCATTERED SHOWERS AND STORMS...WILL
ACCOMPANY THIS FRONT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY...BUT THE COOL FRONT WILL BECOME STATIONARY...JUST SOUTH OF
THE REGION...WITH NORTHERN PLAINS LOW PRESSURE APPROACHING FROM THE
WEST. THE NEXT CHANCE OF RAIN...WILL APPROACH WITH THIS SYSTEM OVER
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 128 PM EDT WED AUG 1 2012
SPECTACULAR START TO THE MONTH OF AUGUST WELL UNDERWAY WITH HIGH
PRESSURE OVERHEAD. NO CHANGES MADE TO GOING FORECAST...WITH JUST
SOME CU DEVELOPMENT NEAR THE IMMEDIATE COASTLINES. WATCHING
UPSTREAM CONVECTIVE DEVELOPING ON THE FRINGE OF PRONOUNCED
MOISTURE RETURN AND STEEP MID LEVEL LAPSE RATE ENVIRONMENT. THIS
WILL BE OUR MAIN ISSUE HEADING INTO THE EVENING AND OVERNIGHT.
MORE ON THAT IN A BIT...
UPDATE ISSUED AT 907 AM EDT WED AUG 1 2012
GOING TO BE A BEAUTIFUL DAY ALL THROUGHOUT NORTHERN MICHIGAN
TODAY...COURTESY OF LOW/MID LEVEL RIDGE AXIS DIRECTLY OVERHEAD.
STILL WATCHING THE EVOLUTION OF SOME PESKY STRATUS ACROSS
NORTHEAST LOWER INTO LAKE HURON WITHIN RESIDUAL LOW LEVEL MOISTURE
AXIS BENEATH A VERY SHARP NEAR-SURFACE INVERSION. PER TRENDS NOTED
YESTERDAY AND THE NATURE OF THESE THINGS...WILL LIKELY SEE THIS
CLOUD BAND HANG ON FOR A FEW MORE HOURS AND HAVE ADJUSTED THE
CLOUD FORECAST AS SUCH. HOWEVER...EARLY AUGUST SUN SHOULD WORK ITS
MAGIC BY LATE MORNING...HELPING RAPIDLY ERODE SAID CLOUD DECK BY
AROUND 16Z AT THE LATEST.
HAVE ALSO SEEN QUITE A BIT OF FOG OVERNIGHT AS EXPECTED...BUT THIS
TOO IS ON THE WAY OUT. QUITE DRY AIRMASS (12Z APX RAOB PWAT WAS
JUST 0.42 INCHES!) DUE OVERHEAD COMBINED WITH INCREASED MIXING
SHOULD SEND DEW POINTS PLUMMETING FOR INLAND LOCATIONS INTO THE
AFTERNOON...AND PER TRENDS UPSTREAM YESTERDAY AND STRONG
GUIDANCE/FORECAST RAOB HINTS...HAVE LOWERED READINGS DOWN INTO THE
40S. THIS WILL RESULT IN MINIMUM RH VALUES DOWN IN THE MID
20S...BUT WITH LIGHT WINDS AND RECENT WIDESPREAD RAIN...NO FIRE
CONCERNS EXPECTED. OUTSIDE OF THAT...GOING HIGHS WELL INTO THE 80S
LOOK JUST FINE. OVERALL A GREAT START TO THE MONTH...ENJOY!
UPDATE ISSUED AT 646 AM EDT WED AUG 1 2012
BAND OF STRATUS HAS DEVELOPED OVER THE LAST HOUR OR SO ACROSS NE
LOWER AND INTERIOR EASTERN UPPER...WHILE SHALLOW GROUND FOG
CONTINUED IN MANY LOW LYING AREAS. BOTH OF THESE WILL MIX
OUT/ERODE OVER THE NEXT COUPLE OF HOURS AS DAYTIME HEATING MIXES
IN SOME QUITE DRY AIR THROUGH 700MB. ALSO HAD TO COOL THE LOWEST
LYING AREAS WHICH DROPPED INTO THE MIDDLE/UPPER 40S. OTHERWISE THE
FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 348 AM EDT WED AUG 1 2012
TROUGHING OVER THE EASTERN COUNTRY AND AN UPPER RIDGE OVER THE
PLAINS...LEADS TO CONTINUED NW FLOW ALOFT INTO THE GREAT LAKES.
ONE SHORTWAVE IS WORKING ACROSS SRN ONTARIO AND IS ASSOCIATED
WITH AN AREA OF INCREASED UPPER LEVEL MOISTURE SEEN ON LATEST WV
IMAGERY. THIS FEATURE IS RUNNING INTO SOME MINOR UPPER RIDGING
OVER NRN MICHIGAN AND ASSOCIATED CLOUDS IN THE HIGHER LEVELS HAS
BEEN WANING WITH TIME. A STRONGER MORE DEFINED SHORTWAVE IS SEEN
IN MANITOBA ALSO PER SATELLITE DATA...AND IN RUC ANALYSIS FOCUSED
AROUND 700MB. THIS WAVE IS WORKING ON A WARM FRONT EXTENDING EAST
FROM A SFC LOW IN SRN MANITOBA. MAXIMUM LOW LEVEL CONVERGENCE
ASSOCIATED WITH A LLJ POINTING INTO THIS REGION AND WESTERN ONTARIO
HAS RESULTED IN AN MCS WITH A SWATH OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS. SKIES ARE CLEAR HERE...WITH ONLY SOME PATCHY HIGH
LEVEL CLOUDS SCRAPING EASTERN UPPER. ALTHOUGH SFC BASED MOISTURE
LINGERS IN THE NORTH WOODS (TDS IN THE 50S AND EVEN LOW 60S)...THE
LOW LEVEL MOISTURE PROFILE SHOWS DRYING FROM ALOFT. THIS HAS HELD
FOG DEVELOPMENT IN CHECK FROM AN AERIAL PERSPECTIVE.
TODAY...NO CONCERNS. HIGH PRESSURE AND LIGHT WINDS CURRENTLY OVER
THE FAR WESTERN GREAT LAKES WILL GRADUALLY WORK IN OVER THE SW
CWA/GTV BAY REGION THROUGH THE DAY. THIS WILL BRING A RETURN TO
SOUTHERLY WINDS THAT INCREASE MORE SO ACROSS EASTERN UPPER. A
LIGHTER WIND REGIME ACROSS NRN LOWER WILL LEAD TO THE DEVELOPMENT
OF LAKE BREEZES AND CONVERGENCE ACROSS NE LOWER. ONE WOULD TEND TO
BELIEVE THAT CUMULUS WILL BE MORE SO CONFINED TO THIS AREA.
HOWEVER...THE LOW LEVEL AIR MASS PROFILE (GENERALLY 700MB AND
BELOW)...IS QUITE DRY. CUMULUS WILL BE HARD TO COME BY WITH MAYBE
JUST SOME STRANDS OF CIRRUS OVERHEAD. A TRULY DECENT SUMMERTIME
DAY WITH TEMPERATURES IN THE WARMER SOUTHERLY FLOW RISING INTO THE
MID AND UPPER 80S ALL AREAS...OUTSIDE OF ONSHORE FLOW CREATED BY
MESOSCALE LAKE BREEZE/ONSHORE FLOW.
BY TONIGHT...THE LOW PRESSURE FROM MANITOBA WILL HAVE SHIFTED
ACROSS SRN MANITOBA...WITH A PRE-FRONTAL TROUGH/COLD FRONT AND
AXIS OF HIGHER THETA-E AIR TO LAY ACROSS EASTERN UPPER IN THE LATE
EVENING...AND ULTIMATELY IN NRN LOWER OVERNIGHT. THE UPPER WAVE
BECOMES SLIGHTLY MORE SHARP TONIGHT...AND THE THETA-E AIR
INCREASES IN THE EVENING BEFORE LOWERING OVERNIGHT...AS
CONVERGENCE ALONG THE TROUGH/COLD FRONT WANES IN THE DEPARTURE OF
THE SHORTWAVE ALOFT. FROM A PATTERN PERSPECTIVE...APPEARS AS
THOUGH THIS SCENARIO LEADS TO BEST CHANCES FOR SEEING
PRECIPITATION WILL BE ACROSS EASTERN UPPER AND FAR NRN LOWER
MICHIGAN WHEN FORCING IS MAXIMIZED WITH GREATEST MOISTURE/WARMTH
AND INSTABILITY (MUCAPES NEARING 1200 J/KG). POPS WILL DECREASE
NEARER THE SAGINAW BAY AS THE SHORTWAVE FORCING AND LOW LEVEL
CONVERGENCE MAXIMUMS DON`T QUITE REACH. REGARDLESS...THE BOUNDARY
DOES WORK THROUGH THIS AREA AS WELL. THE PRECIPITATION PICTURE
BEING PAINTED HERE IS FOR BEST/AND MOST PROLONGED CHANCE FOR
SEEING SHOWERS AND STORMS IN THE NRN HALF OF THE CWA. WILL KEEP
TREND OF ONLY 40% CHANCE THERE WITH 30% FURTHER SOUTH. JUST HAVE
TOO MANY CONCERNS REVOLVING AROUND ANTECEDENT RELATIVELY DRY AIR
MASS...ESPECIALLY THE LOW LEVELS WHICH DON`T EXACTLY DON`T BLOW MY
MIND IN A MOISTURE ADVECTION PERSPECTIVE. THIS FURTHER SUPPORTED
BY LACK OF/NO FGEN IN THE H8-H5 LAYER. ALL-IN-ALL...THIS IS
SEEMINGLY A LACKLUSTER EFFORT FOR PRECIPITATION. CAN FORESEE A HIT
AND MISS SHOWERY IDEA NORTH...WITH DECAYING/LESS AREAL COVERAGE
FURTHER SOUTH INTO THE PRE-DAWN HOURS HOURS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM EDT WED AUG 1 2012
NORTHERN HEMISPHERIC LARGE SCALE PATTERN CONFIGURATION ENSURES
CURRENT NOAM PATTERN IN NO HURRY TO CHANGE ANYTIME SOON...PLACING
THE NORTHERN LAKES IN PERSISTENT...AND AT TIMES ACTIVE...NORTHWEST
FLOW REGIME THROUGH THE REMAINDER OF THE WORK WEEK. CONSISTENT MID
RANGE GUIDANCE SUPPORT FOR SOME RELAXATION IN EASTERN NOAM TROUGHING
OVER THE WEEKEND...ALLOWING RATHER POTENT SHORTWAVE TO DIVE INTO THE
NORTHERN PLAINS...FORCING DOWNSTREAM HEIGHT RISES AND MORE
IMPRESSIVE SURGE OF LOW LEVEL MOISTURE INTO THE REGION. THIS SETS
THE STAGE FOR A POTENTIALLY ACTIVE (SEVERE WEATHER?) WEEKEND AS SAID
WAVES PLOWS THROUGH A SEASONABLY MOIST...INCREASINGLY UNSTABLE
AIRMASS. IN LIGHT OF THE ABOVE...FORECAST CONCERNS CENTER ON
MULTI-PERIOD PRECIP POTENTIAL...AS WELL AS TEMPERATURE AND CLOUD
TRENDS THROUGHOUT.
START OF THE PERIOD SHAPING UP TO BE SOMEWHAT ACTIVE AS LOW
AMPLITUDE WAVE AND ATTENDANT SURFACE LOW DRAG A SLOW MOVING COLD
FRONT SOUTH ACROSS THE MITT THURSDAY. ALTHOUGH BEST MID LEVEL
SUPPORT ACTUALLY PUSHES EAST EARLY...STILL NICE ENOUGH TRIFECTA OF
WEAKISH RER JET DYNAMICS...FRONTAL INDUCED CONVERGENCE...AND FOLDING
OVER THETA-E RIDGE TO SUPPORT INHERITED SHOWER AND THUNDERSTORM
THREAT. GREATEST POTENTIAL LIKELY SOUTH OF THE BIG BRIDGE...
ESPECIALLY IN THE ALL-TO-OFTEN FAVORED NORTHEAST LOWER WHERE LOW
LEVEL CONVERGENCE WILL BE MAXIMIZED. ML CAPE VALUES HOVERING AROUND
1K J/KG AND CORE OF BULK SHEAR REMAINING POST-FRONTAL AND TO OUR
NORTH SUGGEST STORMS SHOULD BEHAVE THEMSELVES. UNCERTAINTY INCREASES
TO ROUND OUT THE WORK WEEK. WHILE GUIDANCE TRENDS AGREE SURFACE
FRONT WILL PUSH SOUTH OF THE REGION (CONVECTIVE OUTFLOW ENHANCED?)
AS HIGH PRESSURE ROTATES SOUTHEAST ACROSS ONTARIO....SAME CANNOT BE
SAID FOR OFF THE DECK CONVERGENCE AXES AND CORE OF DEEPER MOISTURE.
SOME EVIDENCE THESE WILL RESIDE CLOSE ENOUGH TO KEEP AT LEAST A LOW
END SHOWER/STORM THREAT THURSDAY NIGHT INTO FRIDAY. WILL NOT GO THIS
ROUTE JUST YET (PROBS JUST TOO LOW)...BUT SOMETHING TO KEEP IN MIND
AS WE HEAD TOWARDS THE WEEKEND.
AS FOR THE WEEKEND...POTENTIALLY THE MOST "INTERESTING" PORTION OF
THE FORECAST AS GUIDANCE REMAINS AMAZINGLY STEADFAST PINWHEELING A
STRONG SHORTWAVE TROUGH THROUGH THE NORTHERN LAKES LATER SATURDAY
INTO SUNDAY. RETURN FLOW LOOKS TO BE WELL ESTABLISHED AHEAD OF THIS
FEATURE...WITH PERUSAL OF AVAILABLE MOISTURE PROGS SUGGESTING PWAT
VALUES AOA 1.50 INCHES. DYNAMICS LOOK PRETTY FORMIDABLE...WITH NEAR
NEUTRAL TILT WAVE AND POSSIBLE RER JET DYNAMICS OVERTOPPING A
SEASONABLY STRONG COLD FRONT. STILL SOME MINOR TIMING DIFFERENCES
WITH ALL THE ABOVE...BUT OVERALL A PRETTY WELL AGREED UPON FORECAST.
NO DOUBT A MODEL CONSENSUS WILL SUFFICE...FEATURING POSSIBLE SHOWERS
AND STORMS THROUGH THE WEEKEND...WITH THE GREATEST POTENTIAL
OVERNIGHT SATURDAY INTO EARLY SUNDAY. MUCH TOO EARLY TO GET CAUGHT
UP IN INSTABILITY PROGS AND SPECIFIC MID LEVEL WIND CORES...BUT FROM
A PATTERN RECOGNITION STANDPOINT...THIS SYSTEM LOOKS TO HAVE THE
POTENTIAL TO DRIVE A RATHER VIGOROUS (SEVERE?) SQUALL LINE THROUGH
AT LEAST A PORTION OF THE LAKES REGION. FRONTAL TIMING (CURRENT
TRENDS SUPPORT AN UNFAVORABLE EARLY SUNDAY MORNING FRONTAL PASSAGE)
MIGHT NOT EVEN MATTER MUCH GIVEN SUGGESTED DYNAMICS. DEFINITELY
SOMETHING TO MONITOR IN THE COMING DAYS. DRY WEATHER RETURNS FOR THE
BEGINNING OF NEXT WORK WEEK WITH AN AGGRESSIVE PUSH OF HIGH PRESSURE
BUILDING IN BEHIND THE DEPARTING FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 128 PM EDT WED AUG 1 2012
VFR CONDITIONS ARE PRIMARILY EXPECTED AT ALL TERMINAL SITES
THROUGH THE TAF PERIOD. A COLD FRONT SLOWLY DROPPING THROUGH THE
REGION WILL BRING WITH IT SCATTERED SHOWERS AND THUNDERSTORMS FROM
MID EVENING INTO THE OVERNIGHT HOURS...THOUGH WITH COVERAGE NOT
EXPECTED TO BE HIGH...WILL CONTINUE TO HAVE JUST A VICINITY
MENTION. OF COURSE...ANY HEAVIER RAINS MAY BRIEFLY BRING VISBYS
INTO MVFR OR EVEN IFR RANGE. THE FRONT IS EXPECTED TO WASH OUT
ALONG THE M-55 CORRIDOR...LEAVING LINGERING CHANCES FOR A SHOWER
OR STORM FOR MBL AND PERHAPS TVC RIGHT ON THROUGH 18Z
THURSDAY...WHILE APN/PLN DRY OUT. WITH AN INCREASING JET JUST OFF
THE SURFACE OVERNIGHT...LOW LEVEL WIND SHEAR IS A BIG CONCERN.
OTHERWISE...WINDS ARE EXPECTED TO REMAIN MAINLY 10 KNOTS OR LESS
THROUGH THE PERIOD.
&&
.MARINE...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL SLIP SOUTH AND EAST OF THE REGION
TODAY...ALLOWING A SOUTHERLY AND INCREASING WIND FLOW TO
REINTRODUCE A HIGHER MOISTURE CONTENT TO THE GREAT LAKES. A COLD
FRONT ARRIVING LATE TONIGHT WILL WORK ON THIS AIR MASS AND BRING A
CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS TO THE AREA. THE
PRESSURE GRADIENT TIGHTENS UP ENOUGH IN A NEUTRAL STABILITY
SCENARIO FOR A CHANCE AT LOW END SMALL CRAFT ADVISORIES LATER
TONIGHT. WILL NOT INTRODUCE THIS JUST YET...BUT COASTAL CONVERGENT
REGIONS OF NW LOWER MICHIGAN WILL BE THE BEST SHOT AT +25KT GUSTS.
THIS FRONT CONTINUES TO DIVE SOUTH OF US INTO THURSDAY...BEFORE
LIFTING BACK AS A WARM FRONT LATE FRIDAY NIGHT AND INTO THE
WEEKEND. NO OTHER WIND ISSUES ARE FORESEEN THROUGH THE WORK
WEEK...BUT ADVISORIES MAY BE NEEDED FOR THE WEEKEND AHEAD OF NEXT
MORE POTENT COLD FRONT...BOTH AHEAD OF AND BEHIND THIS BOUNDARY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...MB
SHORT TERM...SD
LONG TERM...MB
AVIATION...LAWRENCE
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
907 AM EDT WED AUG 1 2012
.SYNOPSIS...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL DRIFT THROUGH THE GREAT LAKES REGION TODAY...
BRINGING SEASONABLY WARM AND DRY CONDITIONS. MEANWHILE...THE NEXT
LOW PRESSURE SYSTEM AND COOL FRONT...WILL MIGRATE ALONG THE CANADIAN
BORDER. THIS LOW WILL MOVE THROUGH TONIGHT...WITH ITS TRAILING COOL
FRONT SLIDING THROUGH THURSDAY. SCATTERED SHOWERS AND STORMS...WILL
ACCOMPANY THIS FRONT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY...BUT THE COOL FRONT WILL BECOME STATIONARY...JUST SOUTH OF
THE REGION...WITH NORTHERN PLAINS LOW PRESSURE APPROACHING FROM THE
WEST. THE NEXT CHANCE OF RAIN...WILL APPROACH WITH THIS SYSTEM OVER
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 907 AM EDT WED AUG 1 2012
GOING TO BE A BEAUTIFUL DAY ALL THROUGHOUT NORTHERN MICHIGAN
TODAY...COURTESY OF LOW/MID LEVEL RIDGE AXIS DIRECTLY OVERHEAD.
STILL WATCHING THE EVOLUTION OF SOME PESKY STRATUS ACROSS
NORTHEAST LOWER INTO LAKE HURON WITHIN RESIDUAL LOW LEVEL MOISTURE
AXIS BENEATH A VERY SHARP NEAR-SURFACE INVERSION. PER TRENDS NOTED
YESTERDAY AND THE NATURE OF THESE THINGS...WILL LIKELY SEE THIS
CLOUD BAND HANG ON FOR A FEW MORE HOURS AND HAVE ADJUSTED THE
CLOUD FORECAST AS SUCH. HOWEVER...EARLY AUGUST SUN SHOULD WORK ITS
MAGIC BY LATE MORNING...HELPING RAPIDLY ERODE SAID CLOUD DECK BY
AROUND 16Z AT THE LATEST.
HAVE ALSO SEEN QUITE A BIT OF FOG OVERNIGHT AS EXPECTED...BUT THIS
TOO IS ON THE WAY OUT. QUITE DRY AIRMASS (12Z APX RAOB PWAT WAS
JUST 0.42 INCHES!) DUE OVERHEAD COMBINED WITH INCREASED MIXING
SHOULD SEND DEW POINTS PLUMMETING FOR INLAND LOCATIONS INTO THE
AFTERNOON...AND PER TRENDS UPSTREAM YESTERDAY AND STRONG
GUIDANCE/FORECAST RAOB HINTS...HAVE LOWERED READINGS DOWN INTO THE
40S. THIS WILL RESULT IN MINIMUM RH VALUES DOWN IN THE MID
20S...BUT WITH LIGHT WINDS AND RECENT WIDESPREAD RAIN...NO FIRE
CONCERNS EXPECTED. OUTSIDE OF THAT...GOING HIGHS WELL INTO THE 80S
LOOK JUST FINE. OVERALL A GREAT START TO THE MONTH...ENJOY!
UPDATE ISSUED AT 646 AM EDT WED AUG 1 2012
BAND OF STRATUS HAS DEVELOPED OVER THE LAST HOUR OR SO ACROSS NE
LOWER AND INTERIOR EASTERN UPPER...WHILE SHALLOW GROUND FOG
CONTINUED IN MANY LOW LYING AREAS. BOTH OF THESE WILL MIX
OUT/ERODE OVER THE NEXT COUPLE OF HOURS AS DAYTIME HEATING MIXES
IN SOME QUITE DRY AIR THROUGH 700MB. ALSO HAD TO COOL THE LOWEST
LYING AREAS WHICH DROPPED INTO THE MIDDLE/UPPER 40S. OTHERWISE THE
FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 348 AM EDT WED AUG 1 2012
TROUGHING OVER THE EASTERN COUNTRY AND AN UPPER RIDGE OVER THE
PLAINS...LEADS TO CONTINUED NW FLOW ALOFT INTO THE GREAT LAKES.
ONE SHORTWAVE IS WORKING ACROSS SRN ONTARIO AND IS ASSOCIATED
WITH AN AREA OF INCREASED UPPER LEVEL MOISTURE SEEN ON LATEST WV
IMAGERY. THIS FEATURE IS RUNNING INTO SOME MINOR UPPER RIDGING
OVER NRN MICHIGAN AND ASSOCIATED CLOUDS IN THE HIGHER LEVELS HAS
BEEN WANING WITH TIME. A STRONGER MORE DEFINED SHORTWAVE IS SEEN
IN MANITOBA ALSO PER SATELLITE DATA...AND IN RUC ANALYSIS FOCUSED
AROUND 700MB. THIS WAVE IS WORKING ON A WARM FRONT EXTENDING EAST
FROM A SFC LOW IN SRN MANITOBA. MAXIMUM LOW LEVEL CONVERGENCE
ASSOCIATED WITH A LLJ POINTING INTO THIS REGION AND WESTERN ONTARIO
HAS RESULTED IN AN MCS WITH A SWATH OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS. SKIES ARE CLEAR HERE...WITH ONLY SOME PATCHY HIGH
LEVEL CLOUDS SCRAPING EASTERN UPPER. ALTHOUGH SFC BASED MOISTURE
LINGERS IN THE NORTH WOODS (TDS IN THE 50S AND EVEN LOW 60S)...THE
LOW LEVEL MOISTURE PROFILE SHOWS DRYING FROM ALOFT. THIS HAS HELD
FOG DEVELOPMENT IN CHECK FROM AN AERIAL PERSPECTIVE.
TODAY...NO CONCERNS. HIGH PRESSURE AND LIGHT WINDS CURRENTLY OVER
THE FAR WESTERN GREAT LAKES WILL GRADUALLY WORK IN OVER THE SW
CWA/GTV BAY REGION THROUGH THE DAY. THIS WILL BRING A RETURN TO
SOUTHERLY WINDS THAT INCREASE MORE SO ACROSS EASTERN UPPER. A
LIGHTER WIND REGIME ACROSS NRN LOWER WILL LEAD TO THE DEVELOPMENT
OF LAKE BREEZES AND CONVERGENCE ACROSS NE LOWER. ONE WOULD TEND TO
BELIEVE THAT CUMULUS WILL BE MORE SO CONFINED TO THIS AREA.
HOWEVER...THE LOW LEVEL AIR MASS PROFILE (GENERALLY 700MB AND
BELOW)...IS QUITE DRY. CUMULUS WILL BE HARD TO COME BY WITH MAYBE
JUST SOME STRANDS OF CIRRUS OVERHEAD. A TRULY DECENT SUMMERTIME
DAY WITH TEMPERATURES IN THE WARMER SOUTHERLY FLOW RISING INTO THE
MID AND UPPER 80S ALL AREAS...OUTSIDE OF ONSHORE FLOW CREATED BY
MESOSCALE LAKE BREEZE/ONSHORE FLOW.
BY TONIGHT...THE LOW PRESSURE FROM MANITOBA WILL HAVE SHIFTED
ACROSS SRN MANITOBA...WITH A PRE-FRONTAL TROUGH/COLD FRONT AND
AXIS OF HIGHER THETA-E AIR TO LAY ACROSS EASTERN UPPER IN THE LATE
EVENING...AND ULTIMATELY IN NRN LOWER OVERNIGHT. THE UPPER WAVE
BECOMES SLIGHTLY MORE SHARP TONIGHT...AND THE THETA-E AIR
INCREASES IN THE EVENING BEFORE LOWERING OVERNIGHT...AS
CONVERGENCE ALONG THE TROUGH/COLD FRONT WANES IN THE DEPARTURE OF
THE SHORTWAVE ALOFT. FROM A PATTERN PERSPECTIVE...APPEARS AS
THOUGH THIS SCENARIO LEADS TO BEST CHANCES FOR SEEING
PRECIPITATION WILL BE ACROSS EASTERN UPPER AND FAR NRN LOWER
MICHIGAN WHEN FORCING IS MAXIMIZED WITH GREATEST MOISTURE/WARMTH
AND INSTABILITY (MUCAPES NEARING 1200 J/KG). POPS WILL DECREASE
NEARER THE SAGINAW BAY AS THE SHORTWAVE FORCING AND LOW LEVEL
CONVERGENCE MAXIMUMS DON`T QUITE REACH. REGARDLESS...THE BOUNDARY
DOES WORK THROUGH THIS AREA AS WELL. THE PRECIPITATION PICTURE
BEING PAINTED HERE IS FOR BEST/AND MOST PROLONGED CHANCE FOR
SEEING SHOWERS AND STORMS IN THE NRN HALF OF THE CWA. WILL KEEP
TREND OF ONLY 40% CHANCE THERE WITH 30% FURTHER SOUTH. JUST HAVE
TOO MANY CONCERNS REVOLVING AROUND ANTECEDENT RELATIVELY DRY AIR
MASS...ESPECIALLY THE LOW LEVELS WHICH DON`T EXACTLY DON`T BLOW MY
MIND IN A MOISTURE ADVECTION PERSPECTIVE. THIS FURTHER SUPPORTED
BY LACK OF/NO FGEN IN THE H8-H5 LAYER. ALL-IN-ALL...THIS IS
SEEMINGLY A LACKLUSTER EFFORT FOR PRECIPITATION. CAN FORESEE A HIT
AND MISS SHOWERY IDEA NORTH...WITH DECAYING/LESS AREAL COVERAGE
FURTHER SOUTH INTO THE PRE-DAWN HOURS HOURS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM EDT WED AUG 1 2012
NORTHERN HEMISPHERIC LARGE SCALE PATTERN CONFIGURATION ENSURES
CURRENT NOAM PATTERN IN NO HURRY TO CHANGE ANYTIME SOON...PLACING
THE NORTHERN LAKES IN PERSISTENT...AND AT TIMES ACTIVE...NORTHWEST
FLOW REGIME THROUGH THE REMAINDER OF THE WORK WEEK. CONSISTENT MID
RANGE GUIDANCE SUPPORT FOR SOME RELAXATION IN EASTERN NOAM TROUGHING
OVER THE WEEKEND...ALLOWING RATHER POTENT SHORTWAVE TO DIVE INTO THE
NORTHERN PLAINS...FORCING DOWNSTREAM HEIGHT RISES AND MORE
IMPRESSIVE SURGE OF LOW LEVEL MOISTURE INTO THE REGION. THIS SETS
THE STAGE FOR A POTENTIALLY ACTIVE (SEVERE WEATHER?) WEEKEND AS SAID
WAVES PLOWS THROUGH A SEASONABLY MOIST...INCREASINGLY UNSTABLE
AIRMASS. IN LIGHT OF THE ABOVE...FORECAST CONCERNS CENTER ON
MULTI-PERIOD PRECIP POTENTIAL...AS WELL AS TEMPERATURE AND CLOUD
TRENDS THROUGHOUT.
START OF THE PERIOD SHAPING UP TO BE SOMEWHAT ACTIVE AS LOW
AMPLITUDE WAVE AND ATTENDANT SURFACE LOW DRAG A SLOW MOVING COLD
FRONT SOUTH ACROSS THE MITT THURSDAY. ALTHOUGH BEST MID LEVEL
SUPPORT ACTUALLY PUSHES EAST EARLY...STILL NICE ENOUGH TRIFECTA OF
WEAKISH RER JET DYNAMICS...FRONTAL INDUCED CONVERGENCE...AND FOLDING
OVER THETA-E RIDGE TO SUPPORT INHERITED SHOWER AND THUNDERSTORM
THREAT. GREATEST POTENTIAL LIKELY SOUTH OF THE BIG BRIDGE...
ESPECIALLY IN THE ALL-TO-OFTEN FAVORED NORTHEAST LOWER WHERE LOW
LEVEL CONVERGENCE WILL BE MAXIMIZED. ML CAPE VALUES HOVERING AROUND
1K J/KG AND CORE OF BULK SHEAR REMAINING POST-FRONTAL AND TO OUR
NORTH SUGGEST STORMS SHOULD BEHAVE THEMSELVES. UNCERTAINTY INCREASES
TO ROUND OUT THE WORK WEEK. WHILE GUIDANCE TRENDS AGREE SURFACE
FRONT WILL PUSH SOUTH OF THE REGION (CONVECTIVE OUTFLOW ENHANCED?)
AS HIGH PRESSURE ROTATES SOUTHEAST ACROSS ONTARIO....SAME CANNOT BE
SAID FOR OFF THE DECK CONVERGENCE AXES AND CORE OF DEEPER MOISTURE.
SOME EVIDENCE THESE WILL RESIDE CLOSE ENOUGH TO KEEP AT LEAST A LOW
END SHOWER/STORM THREAT THURSDAY NIGHT INTO FRIDAY. WILL NOT GO THIS
ROUTE JUST YET (PROBS JUST TOO LOW)...BUT SOMETHING TO KEEP IN MIND
AS WE HEAD TOWARDS THE WEEKEND.
AS FOR THE WEEKEND...POTENTIALLY THE MOST "INTERESTING" PORTION OF
THE FORECAST AS GUIDANCE REMAINS AMAZINGLY STEADFAST PINWHEELING A
STRONG SHORTWAVE TROUGH THROUGH THE NORTHERN LAKES LATER SATURDAY
INTO SUNDAY. RETURN FLOW LOOKS TO BE WELL ESTABLISHED AHEAD OF THIS
FEATURE...WITH PERUSAL OF AVAILABLE MOISTURE PROGS SUGGESTING PWAT
VALUES AOA 1.50 INCHES. DYNAMICS LOOK PRETTY FORMIDABLE...WITH NEAR
NEUTRAL TILT WAVE AND POSSIBLE RER JET DYNAMICS OVERTOPPING A
SEASONABLY STRONG COLD FRONT. STILL SOME MINOR TIMING DIFFERENCES
WITH ALL THE ABOVE...BUT OVERALL A PRETTY WELL AGREED UPON FORECAST.
NO DOUBT A MODEL CONSENSUS WILL SUFFICE...FEATURING POSSIBLE SHOWERS
AND STORMS THROUGH THE WEEKEND...WITH THE GREATEST POTENTIAL
OVERNIGHT SATURDAY INTO EARLY SUNDAY. MUCH TOO EARLY TO GET CAUGHT
UP IN INSTABILITY PROGS AND SPECIFIC MID LEVEL WIND CORES...BUT FROM
A PATTERN RECOGNITION STANDPOINT...THIS SYSTEM LOOKS TO HAVE THE
POTENTIAL TO DRIVE A RATHER VIGOROUS (SEVERE?) SQUALL LINE THROUGH
AT LEAST A PORTION OF THE LAKES REGION. FRONTAL TIMING (CURRENT
TRENDS SUPPORT AN UNFAVORABLE EARLY SUNDAY MORNING FRONTAL PASSAGE)
MIGHT NOT EVEN MATTER MUCH GIVEN SUGGESTED DYNAMICS. DEFINITELY
SOMETHING TO MONITOR IN THE COMING DAYS. DRY WEATHER RETURNS FOR THE
BEGINNING OF NEXT WORK WEEK WITH AN AGGRESSIVE PUSH OF HIGH PRESSURE
BUILDING IN BEHIND THE DEPARTING FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 907 AM EDT WED AUG 1 2012
MAINLY VFR CONDITIONS ARE EXPECTED THRU WEDNESDAY EVENING AS HIGH
PRESSURE PUSHES THROUGH NORTHERN MICHIGAN. THE EXCEPTION WILL BE A
BRIEF ROUND OF LOW STRATUS IMPACTING THE APN TERMINAL THROUGH MID
MORNING...WITH FOG BURNING OFF QUICKLY BY 14Z. OTHERWISE...LAKE
BREEZES WILL DEVELOP BY THIS AFTERNOON AND SKIES WILL BECOME
RATHER SUNNY WITH DAYTIME HEATING MIXING IN DRY AIR ALOFT. OUR
NEXT CHANCE OF SHRA/TSRA WILL DEVELOP LATE TONIGHT AS A WEAK FRONT
DROPS INTO NRN MICHIGAN. STILL APPEARS BETTER CHANCES OF PRECIP
WILL HOLD OFF UNTIL AFTER 06Z THURSDAY...BUT COVERAGE IS EXPECTED
TO BE SMALL. WILL INTRODUCE A VCSH IN THIS TAF ISSUANCE.
&&
.MARINE...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL SLIP SOUTH AND EAST OF THE REGION
TODAY...ALLOWING A SOUTHERLY AND INCREASING WIND FLOW TO
REINTRODUCE A HIGHER MOISTURE CONTENT TO THE GREAT LAKES. A COLD
FRONT ARRIVING LATE TONIGHT WILL WORK ON THIS AIR MASS AND BRING A
CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS TO THE AREA. THE
PRESSURE GRADIENT TIGHTENS UP ENOUGH IN A NEUTRAL STABILITY
SCENARIO FOR A CHANCE AT LOW END SMALL CRAFT ADVISORIES LATER
TONIGHT. WILL NOT INTRODUCE THIS JUST YET...BUT COASTAL CONVERGENT
REGIONS OF NW LOWER MICHIGAN WILL BE THE BEST SHOT AT +25KT GUSTS.
THIS FRONT CONTINUES TO DIVE SOUTH OF US INTO THURSDAY...BEFORE
LIFTING BACK AS A WARM FRONT LATE FRIDAY NIGHT AND INTO THE
WEEKEND. NO OTHER WIND ISSUES ARE FORESEEN THROUGH THE WORK
WEEK...BUT ADVISORIES MAY BE NEEDED FOR THE WEEKEND AHEAD OF NEXT
MORE POTENT COLD FRONT...BOTH AHEAD OF AND BEHIND THIS BOUNDARY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...MB
SHORT TERM...SD
LONG TERM...MB
AVIATION...SMD/LAWRENCE
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
655 AM EDT WED AUG 1 2012
.SYNOPSIS...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL DRIFT THROUGH THE GREAT LAKES REGION TODAY...
BRINGING SEASONABLY WARM AND DRY CONDITIONS. MEANWHILE...THE NEXT
LOW PRESSURE SYSTEM AND COOL FRONT...WILL MIGRATE ALONG THE CANADIAN
BORDER. THIS LOW WILL MOVE THROUGH TONIGHT...WITH ITS TRAILING COOL
FRONT SLIDING THROUGH THURSDAY. SCATTERED SHOWERS AND STORMS...WILL
ACCOMPANY THIS FRONT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY...BUT THE COOL FRONT WILL BECOME STATIONARY...JUST SOUTH OF
THE REGION...WITH NORTHERN PLAINS LOW PRESSURE APPROACHING FROM THE
WEST. THE NEXT CHANCE OF RAIN...WILL APPROACH WITH THIS SYSTEM OVER
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 646 AM EDT WED AUG 1 2012
BAND OF STRATUS HAS DEVELOPED OVER THE LAST HOUR OR SO ACROSS NE
LOWER AND INTERIOR EASTERN UPPER...WHILE SHALLOW GROUND FOG
CONTINUED IN MANY LOW LYING AREAS. BOTH OF THESE WILL MIX
OUT/ERODE OVER THE NEXT COUPLE OF HOURS AS DAYTIME HEATING MIXES
IN SOME QUITE DRY AIR THROUGH 700MB. ALSO HAD TO COOL THE LOWEST
LYING AREAS WHICH DROPPED INTO THE MIDDLE/UPPER 40S. OTHERWISE THE
FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 348 AM EDT WED AUG 1 2012
TROUGHING OVER THE EASTERN COUNTRY AND AN UPPER RIDGE OVER THE
PLAINS...LEADS TO CONTINUED NW FLOW ALOFT INTO THE GREAT LAKES.
ONE SHORTWAVE IS WORKING ACROSS SRN ONTARIO AND IS ASSOCIATED
WITH AN AREA OF INCREASED UPPER LEVEL MOISTURE SEEN ON LATEST WV
IMAGERY. THIS FEATURE IS RUNNING INTO SOME MINOR UPPER RIDGING
OVER NRN MICHIGAN AND ASSOCIATED CLOUDS IN THE HIGHER LEVELS HAS
BEEN WANING WITH TIME. A STRONGER MORE DEFINED SHORTWAVE IS SEEN
IN MANITOBA ALSO PER SATELLITE DATA...AND IN RUC ANALYSES FOCUSED
AROUND 700MB. THIS WAVE IS WORKING ON A WARM FRONT EXTENDING EAST
FROM A SFC LOW IN SRN MANITOBA. MAXIMUM LOW LEVEL CONVERGENCE
ASSOCIATED WITH A LLJ POINTING INTO THIS REGION AND WESTERN ONTARIO
HAS RESULTED IN AN MCS WITH A SWATH OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS. SKIES ARE CLEAR HERE...WITH ONLY SOME PATCHY HIGH
LEVEL CLOUDS SCRAPING EASTERN UPPER. ALTHOUGH SFC BASED MOISTURE
LINGERS IN THE NORTH WOODS (TDS IN THE 50S AND EVEN LOW 60S)...THE
LOW LEVEL MOISTURE PROFILE SHOWS DRYING FROM ALOFT. THIS HAS HELD
FOG DEVELOPMENT IN CHECK FROM AN AERIAL PERSPECTIVE.
TODAY...NO CONCERNS. HIGH PRESSURE AND LIGHT WINDS CURRENTLY OVER
THE FAR WESTERN GREAT LAKES WILL GRADUALLY WORK IN OVER THE SW
CWA/GTV BAY REGION THROUGH THE DAY. THIS WILL BRING A RETURN TO
SOUTHERLY WINDS THAT INCREASE MORE SO ACROSS EASTERN UPPER. A
LIGHTER WIND REGIME ACROSS NRN LOWER WILL LEAD TO THE DEVELOPMENT
OF LAKE BREEZES AND CONVERGENCE ACROSS NE LOWER. ONE WOULD TEND TO
BELIEVE THAT CUMULUS WILL BE MORE SO CONFINED TO THIS AREA.
HOWEVER...THE LOW LEVEL AIR MASS PROFILE (GENERALLY 700MB AND
BELOW)...IS QUITE DRY. CUMULUS WILL BE HARD TO COME BY WITH MAYBE
JUST SOME STRANDS OF CIRRUS OVERHEAD. A TRULY DECENT SUMMERTIME
DAY WITH TEMPERATURES IN THE WARMER SOUTHERLY FLOW RISING INTO THE
MID AND UPPER 80S ALL AREAS...OUTSIDE OF ONSHORE FLOW CREATED BY
MESOSCALE LAKE BREEZE/ONSHORE FLOW.
BY TONIGHT...THE LOW PRESSURE FROM MANITOBA WILL HAVE SHIFTED
ACROSS SRN MANITOBA...WITH A PRE-FRONTAL TROUGH/COLD FRONT AND
AXIS OF HIGHER THETA-E AIR TO LAY ACROSS EASTERN UPPER IN THE LATE
EVENING...AND ULTIMATELY IN NRN LOWER OVERNIGHT. THE UPPER WAVE
BECOMES SLIGHTLY MORE SHARP TONIGHT...AND THE THETA-E AIR
INCREASES IN THE EVENING BEFORE LOWERING OVERNIGHT...AS
CONVERGENCE ALONG THE TROUGH/COLD FRONT WANES IN THE DEPARTURE OF
THE SHORTWAVE ALOFT. FROM A PATTERN PERSPECTIVE...APPEARS AS
THOUGH THIS SCENARIO LEADS TO BEST CHANCES FOR SEEING
PRECIPITATION WILL BE ACROSS EASTERN UPPER AND FAR NRN LOWER
MICHIGAN WHEN FORCING IS MAXIMIZED WITH GREATEST MOISTURE/WARMTH
AND INSTABILITY (MUCAPES NEARING 1200 J/KG). POPS WILL DECREASE
NEARER THE SAGINAW BAY AS THE SHORTWAVE FORCING AND LOW LEVEL
CONVERGENCE MAXIMUMS DON`T QUITE REACH. REGARDLESS...THE BOUNDARY
DOES WORK THROUGH THIS AREA AS WELL. THE PRECIPITATION PICTURE
BEING PAINTED HERE IS FOR BEST/AND MOST PROLONGED CHANCE FOR
SEEING SHOWERS AND STORMS IN THE NRN HALF OF THE CWA. WILL KEEP
TREND OF ONLY 40% CHANCE THERE WITH 30% FURTHER SOUTH. JUST HAVE
TOO MANY CONCERNS REVOLVING AROUND ANTECEDENT RELATIVELY DRY AIR
MASS...ESPECIALLY THE LOW LEVELS WHICH DON`T EXACTLY DON`T BLOW MY
MIND IN A MOISTURE ADVECTION PERSPECTIVE. THIS FURTHER SUPPORTED
BY LACK OF/NO FGEN IN THE H8-H5 LAYER. ALL-IN-ALL...THIS IS
SEEMINGLY A LACKLUSTER EFFORT FOR PRECIPITATION. CAN FORESEE A HIT
AND MISS SHOWERY IDEA NORTH...WITH DECAYING/LESS AREAL COVERAGE
FURTHER SOUTH INTO THE PRE-DAWN HOURS HOURS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM EDT WED AUG 1 2012
NORTHERN HEMISPHERIC LARGE SCALE PATTERN CONFIGURATION ENSURES
CURRENT NOAM PATTERN IN NO HURRY TO CHANGE ANYTIME SOON...PLACING
THE NORTHERN LAKES IN PERSISTENT...AND AT TIMES ACTIVE...NORTHWEST
FLOW REGIME THROUGH THE REMAINDER OF THE WORK WEEK. CONSISTENT MID
RANGE GUIDANCE SUPPORT FOR SOME RELAXATION IN EASTERN NOAM TROUGHING
OVER THE WEEKEND...ALLOWING RATHER POTENT SHORTWAVE TO DIVE INTO THE
NORTHERN PLAINS...FORCING DOWNSTREAM HEIGHT RISES AND MORE
IMPRESSIVE SURGE OF LOW LEVEL MOISTURE INTO THE REGION. THIS SETS
THE STAGE FOR A POTENTIALLY ACTIVE (SEVERE WEATHER?) WEEKEND AS SAID
WAVES PLOWS THROUGH A SEASONABLY MOIST...INCREASINGLY UNSTABLE
AIRMASS. IN LIGHT OF THE ABOVE...FORECAST CONCERNS CENTER ON
MULTI-PERIOD PRECIP POTENTIAL...AS WELL AS TEMPERATURE AND CLOUD
TRENDS THROUGHOUT.
START OF THE PERIOD SHAPING UP TO BE SOMEWHAT ACTIVE AS LOW
AMPLITUDE WAVE AND ATTENDANT SURFACE LOW DRAG A SLOW MOVING COLD
FRONT SOUTH ACROSS THE MITT THURSDAY. ALTHOUGH BEST MID LEVEL
SUPPORT ACTUALLY PUSHES EAST EARLY...STILL NICE ENOUGH TRIFECTA OF
WEAKISH RER JET DYNAMICS...FRONTAL INDUCED CONVERGENCE...AND FOLDING
OVER THETA-E RIDGE TO SUPPORT INHERITED SHOWER AND THUNDERSTORM
THREAT. GREATEST POTENTIAL LIKELY SOUTH OF THE BIG BRIDGE...
ESPECIALLY IN THE ALL-TO-OFTEN FAVORED NORTHEAST LOWER WHERE LOW
LEVEL CONVERGENCE WILL BE MAXIMIZED. ML CAPE VALUES HOVERING AROUND
1K J/KG AND CORE OF BULK SHEAR REMAINING POST-FRONTAL AND TO OUR
NORTH SUGGEST STORMS SHOULD BEHAVE THEMSELVES. UNCERTAINTY INCREASES
TO ROUND OUT THE WORK WEEK. WHILE GUIDANCE TRENDS AGREE SURFACE
FRONT WILL PUSH SOUTH OF THE REGION (CONVECTIVE OUTFLOW ENHANCED?)
AS HIGH PRESSURE ROTATES SOUTHEAST ACROSS ONTARIO....SAME CANNOT BE
SAID FOR OFF THE DECK CONVERGENCE AXES AND CORE OF DEEPER MOISTURE.
SOME EVIDENCE THESE WILL RESIDE CLOSE ENOUGH TO KEEP AT LEAST A LOW
END SHOWER/STORM THREAT THURSDAY NIGHT INTO FRIDAY. WILL NOT GO THIS
ROUTE JUST YET (PROBS JUST TOO LOW)...BUT SOMETHING TO KEEP IN MIND
AS WE HEAD TOWARDS THE WEEKEND.
AS FOR THE WEEKEND...POTENTIALLY THE MOST "INTERESTING" PORTION OF
THE FORECAST AS GUIDANCE REMAINS AMAZINGLY STEADFAST PINWHEELING A
STRONG SHORTWAVE TROUGH THROUGH THE NORTHERN LAKES LATER SATURDAY
INTO SUNDAY. RETURN FLOW LOOKS TO BE WELL ESTABLISHED AHEAD OF THIS
FEATURE...WITH PERUSAL OF AVAILABLE MOISTURE PROGS SUGGESTING PWAT
VALUES AOA 1.50 INCHES. DYNAMICS LOOK PRETTY FORMIDABLE...WITH NEAR
NEUTRAL TILT WAVE AND POSSIBLE RER JET DYNAMICS OVERTOPPING A
SEASONABLY STRONG COLD FRONT. STILL SOME MINOR TIMING DIFFERENCES
WITH ALL THE ABOVE...BUT OVERALL A PRETTY WELL AGREED UPON FORECAST.
NO DOUBT A MODEL CONSENSUS WILL SUFFICE...FEATURING POSSIBLE SHOWERS
AND STORMS THROUGH THE WEEKEND...WITH THE GREATEST POTENTIAL
OVERNIGHT SATURDAY INTO EARLY SUNDAY. MUCH TOO EARLY TO GET CAUGHT
UP IN INSTABILITY PROGS AND SPECIFIC MID LEVEL WIND CORES...BUT FROM
A PATTERN RECOGNITION STANDPOINT...THIS SYSTEM LOOKS TO HAVE THE
POTENTIAL TO DRIVE A RATHER VIGOROUS (SEVERE?) SQUALL LINE THROUGH
AT LEAST A PORTION OF THE LAKES REGION. FRONTAL TIMING (CURRENT
TRENDS SUPPORT AN UNFAVORABLE EARLY SUNDAY MORNING FRONTAL PASSAGE)
MIGHT NOT EVEN MATTER MUCH GIVEN SUGGESTED DYNAMICS. DEFINITELY
SOMETHING TO MONITOR IN THE COMING DAYS. DRY WEATHER RETURNS FOR THE
BEGINNING OF NEXT WORK WEEK WITH AN AGGRESSIVE PUSH OF HIGH PRESSURE
BUILDING IN BEHIND THE DEPARTING FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM EDT WED AUG 1 2012
MAINLY VFR CONDITIONS ARE EXPECTED THRU WEDNESDAY EVENING AS HIGH
PRESSURE PUSHES THROUGH NORTHERN MICHIGAN. FOG WILL CONTINUOUSLY
IMPACT MBL AND PLN FOR ANOTHER HOUR OR SO. OTHERWISE...LAKE
BREEZES WILL DEVELOP BY THIS AFTERNOON AND SKIES WILL BECOME
RATHER SUNNY WITH DAYTIME HEATING MIXING IN DRY AIR ALOFT. OUR
NEXT CHANCE OF SHRA/TSRA WILL DEVELOP LATE TONIGHT AS A
WEAK FRONT DROPS INTO NRN MICHIGAN. STILL APPEARS BETTER CHANCES
OF PRECIP WILL HOLD OFF UNTIL AFTER 06Z THURSDAY...BUT COVERAGE IS
EXPECTED TO BE SMALL. WILL INTRO A VCSH IN THIS TAF ISSUANCE.
&&
.MARINE...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL SLIP SOUTH AND EAST OF THE REGION
TODAY...ALLOWING A SOUTHERLY AND INCREASING WIND FLOW TO
REINTRODUCE A HIGHER MOISTURE CONTENT TO THE GREAT LAKES. A COLD
FRONT ARRIVING LATE TONIGHT WILL WORK ON THIS AIR MASS AND BRING A
CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS TO THE AREA. THE
PRESSURE GRADIENT TIGHTENS UP ENOUGH IN A NEUTRAL STABILITY
SCENARIO FOR A CHANCE AT LOW END SMALL CRAFT ADVISORIES LATER
TONIGHT. WILL NOT INTRODUCE THIS JUST YET...BUT COASTAL CONVERGENT
REGIONS OF NW LOWER MICHIGAN WILL BE THE BEST SHOT AT +25KT GUSTS.
THIS FRONT CONTINUES TO DIVE SOUTH OF US INTO THURSDAY...BEFORE
LIFTING BACK AS A WARM FRONT LATE FRIDAY NIGHT AND INTO THE
WEEKEND. NO OTHER WIND ISSUES ARE FORESEEN THROUGH THE WORK
WEEK...BUT ADVISORIES MAY BE NEEDED FOR THE WEEKEND AHEAD OF NEXT
MORE POTENT COLD FRONT...BOTH AHEAD OF AND BEHIND THIS BOUNDARY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...MB
SHORT TERM...SD
LONG TERM...MB
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
349 AM EDT WED AUG 1 2012
.SYNOPSIS...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL DRIFT THROUGH THE GREAT LAKES REGION TODAY...
BRINGING SEASONABLY WARM AND DRY CONDITIONS. MEANWHILE...THE NEXT
LOW PRESSURE SYSTEM AND COOL FRONT...WILL MIGRATE ALONG THE CANADIAN
BORDER. THIS LOW WILL MOVE THROUGH TONIGHT...WITH ITS TRAILING COOL
FRONT SLIDING THROUGH THURSDAY. SCATTERED SHOWERS AND STORMS...WILL
ACCOMPANY THIS FRONT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY...BUT THE COOL FRONT WILL BECOME STATIONARY...JUST SOUTH OF
THE REGION...WITH NORTHERN PLAINS LOW PRESSURE APPROACHING FROM THE
WEST. THE NEXT CHANCE OF RAIN...WILL APPROACH WITH THIS SYSTEM OVER
THE WEEKEND.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 348 AM EDT WED AUG 1 2012
TROUGHING OVER THE EASTERN COUNTRY AND AN UPPER RIDGE OVER THE
PLAINS...LEADS TO CONTINUED NW FLOW ALOFT INTO THE GREAT LAKES.
ONE SHORTWAVE IS WORKING ACROSS SRN ONTARIO AND IS ASSOCIATED
WITH AN AREA OF INCREASED UPPER LEVEL MOISTURE SEEN ON LATEST WV
IMAGERY. THIS FEATURE IS RUNNING INTO SOME MINOR UPPER RIDGING
OVER NRN MICHIGAN AND ASSOCIATED CLOUDS IN THE HIGHER LEVELS HAS
BEEN WANING WITH TIME. A STRONGER MORE DEFINED SHORTWAVE IS SEEN
IN MANITOBA ALSO PER SATELLITE DATA...AND IN RUC ANALYSES FOCUSED
AROUND 700MB. THIS WAVE IS WORKING ON A WARM FRONT EXTENDING EAST
FROM A SFC LOW IN SRN MANITOBA. MAXIMUM LOW LEVEL CONVERGENCE
ASSOCIATED WITH A LLJ POINTING INTO THIS REGION AND WESTERN ONTARIO
HAS RESULTED IN AN MCS WITH A SWATH OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS. SKIES ARE CLEAR HERE...WITH ONLY SOME PATCHY HIGH
LEVEL CLOUDS SCRAPING EASTERN UPPER. ALTHOUGH SFC BASED MOISTURE
LINGERS IN THE NORTH WOODS (TDS IN THE 50S AND EVEN LOW 60S)...THE
LOW LEVEL MOISTURE PROFILE SHOWS DRYING FROM ALOFT. THIS HAS HELD
FOG DEVELOPMENT IN CHECK FROM AN AERIAL PERSPECTIVE.
TODAY...NO CONCERNS. HIGH PRESSURE AND LIGHT WINDS CURRENTLY OVER
THE FAR WESTERN GREAT LAKES WILL GRADUALLY WORK IN OVER THE SW
CWA/GTV BAY REGION THROUGH THE DAY. THIS WILL BRING A RETURN TO
SOUTHERLY WINDS THAT INCREASE MORE SO ACROSS EASTERN UPPER. A
LIGHTER WIND REGIME ACROSS NRN LOWER WILL LEAD TO THE DEVELOPMENT
OF LAKE BREEZES AND CONVERGENCE ACROSS NE LOWER. ONE WOULD TEND TO
BELIEVE THAT CUMULUS WILL BE MORE SO CONFINED TO THIS AREA.
HOWEVER...THE LOW LEVEL AIR MASS PROFILE (GENERALLY 700MB AND
BELOW)...IS QUITE DRY. CUMULUS WILL BE HARD TO COME BY WITH MAYBE
JUST SOME STRANDS OF CIRRUS OVERHEAD. A TRULY DECENT SUMMERTIME
DAY WITH TEMPERATURES IN THE WARMER SOUTHERLY FLOW RISING INTO THE
MID AND UPPER 80S ALL AREAS...OUTSIDE OF ONSHORE FLOW CREATED BY
MESOSCALE LAKE BREEZE/ONSHORE FLOW.
BY TONIGHT...THE LOW PRESSURE FROM MANITOBA WILL HAVE SHIFTED
ACROSS SRN MANITOBA...WITH A PRE-FRONTAL TROUGH/COLD FRONT AND
AXIS OF HIGHER THETA-E AIR TO LAY ACROSS EASTERN UPPER IN THE LATE
EVENING...AND ULTIMATELY IN NRN LOWER OVERNIGHT. THE UPPER WAVE
BECOMES SLIGHTLY MORE SHARP TONIGHT...AND THE THETA-E AIR
INCREASES IN THE EVENING BEFORE LOWERING OVERNIGHT...AS
CONVERGENCE ALONG THE TROUGH/COLD FRONT WANES IN THE DEPARTURE OF
THE SHORTWAVE ALOFT. FROM A PATTERN PERSPECTIVE...APPEARS AS
THOUGH THIS SCENARIO LEADS TO BEST CHANCES FOR SEEING
PRECIPITATION WILL BE ACROSS EASTERN UPPER AND FAR NRN LOWER
MICHIGAN WHEN FORCING IS MAXIMIZED WITH GREATEST MOISTURE/WARMTH
AND INSTABILITY (MUCAPES NEARING 1200 J/KG). POPS WILL DECREASE
NEARER THE SAGINAW BAY AS THE SHORTWAVE FORCING AND LOW LEVEL
CONVERGENCE MAXIMUMS DON`T QUITE REACH. REGARDLESS...THE BOUNDARY
DOES WORK THROUGH THIS AREA AS WELL. THE PRECIPITATION PICTURE
BEING PAINTED HERE IS FOR BEST/AND MOST PROLONGED CHANCE FOR
SEEING SHOWERS AND STORMS IN THE NRN HALF OF THE CWA. WILL KEEP
TREND OF ONLY 40% CHANCE THERE WITH 30% FURTHER SOUTH. JUST HAVE
TOO MANY CONCERNS REVOLVING AROUND ANTECEDENT RELATIVELY DRY AIR
MASS...ESPECIALLY THE LOW LEVELS WHICH DON`T EXACTLY DON`T BLOW MY
MIND IN A MOISTURE ADVECTION PERSPECTIVE. THIS FURTHER SUPPORTED
BY LACK OF/NO FGEN IN THE H8-H5 LAYER. ALL-IN-ALL...THIS IS
SEEMINGLY A LACKLUSTER EFFORT FOR PRECIPITATION. CAN FORESEE A HIT
AND MISS SHOWERY IDEA NORTH...WITH DECAYING/LESS AREAL COVERAGE
FURTHER SOUTH INTO THE PRE-DAWN HOURS HOURS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM EDT WED AUG 1 2012
NORTHERN HEMISPHERIC LARGE SCALE PATTERN CONFIGURATION ENSURES
CURRENT NOAM PATTERN IN NO HURRY TO CHANGE ANYTIME SOON...PLACING
THE NORTHERN LAKES IN PERSISTENT...AND AT TIMES ACTIVE...NORTHWEST
FLOW REGIME THROUGH THE REMAINDER OF THE WORK WEEK. CONSISTENT MID
RANGE GUIDANCE SUPPORT FOR SOME RELAXATION IN EASTERN NOAM TROUGHING
OVER THE WEEKEND...ALLOWING RATHER POTENT SHORTWAVE TO DIVE INTO THE
NORTHERN PLAINS...FORCING DOWNSTREAM HEIGHT RISES AND MORE
IMPRESSIVE SURGE OF LOW LEVEL MOISTURE INTO THE REGION. THIS SETS
THE STAGE FOR A POTENTIALLY ACTIVE (SEVERE WEATHER?) WEEKEND AS SAID
WAVES PLOWS THROUGH A SEASONABLY MOIST...INCREASINGLY UNSTABLE
AIRMASS. IN LIGHT OF THE ABOVE...FORECAST CONCERNS CENTER ON
MULTI-PERIOD PRECIP POTENTIAL...AS WELL AS TEMPERATURE AND CLOUD
TRENDS THROUGHOUT.
START OF THE PERIOD SHAPING UP TO BE SOMEWHAT ACTIVE AS LOW
AMPLITUDE WAVE AND ATTENDANT SURFACE LOW DRAG A SLOW MOVING COLD
FRONT SOUTH ACROSS THE MITT THURSDAY. ALTHOUGH BEST MID LEVEL
SUPPORT ACTUALLY PUSHES EAST EARLY...STILL NICE ENOUGH TRIFECTA OF
WEAKISH RER JET DYNAMICS...FRONTAL INDUCED CONVERGENCE...AND FOLDING
OVER THETA-E RIDGE TO SUPPORT INHERITED SHOWER AND THUNDERSTORM
THREAT. GREATEST POTENTIAL LIKELY SOUTH OF THE BIG BRIDGE...
ESPECIALLY IN THE ALL-TO-OFTEN FAVORED NORTHEAST LOWER WHERE LOW
LEVEL CONVERGENCE WILL BE MAXIMIZED. ML CAPE VALUES HOVERING AROUND
1K J/KG AND CORE OF BULK SHEAR REMAINING POST-FRONTAL AND TO OUR
NORTH SUGGEST STORMS SHOULD BEHAVE THEMSELVES. UNCERTAINTY INCREASES
TO ROUND OUT THE WORK WEEK. WHILE GUIDANCE TRENDS AGREE SURFACE
FRONT WILL PUSH SOUTH OF THE REGION (CONVECTIVE OUTFLOW ENHANCED?)
AS HIGH PRESSURE ROTATES SOUTHEAST ACROSS ONTARIO....SAME CANNOT BE
SAID FOR OFF THE DECK CONVERGENCE AXES AND CORE OF DEEPER MOISTURE.
SOME EVIDENCE THESE WILL RESIDE CLOSE ENOUGH TO KEEP AT LEAST A LOW
END SHOWER/STORM THREAT THURSDAY NIGHT INTO FRIDAY. WILL NOT GO THIS
ROUTE JUST YET (PROBS JUST TOO LOW)...BUT SOMETHING TO KEEP IN MIND
AS WE HEAD TOWARDS THE WEEKEND.
AS FOR THE WEEKEND...POTENTIALLY THE MOST "INTERESTING" PORTION OF
THE FORECAST AS GUIDANCE REMAINS AMAZINGLY STEADFAST PINWHEELING A
STRONG SHORTWAVE TROUGH THROUGH THE NORTHERN LAKES LATER SATURDAY
INTO SUNDAY. RETURN FLOW LOOKS TO BE WELL ESTABLISHED AHEAD OF THIS
FEATURE...WITH PERUSAL OF AVAILABLE MOISTURE PROGS SUGGESTING PWAT
VALUES AOA 1.50 INCHES. DYNAMICS LOOK PRETTY FORMIDABLE...WITH NEAR
NEUTRAL TILT WAVE AND POSSIBLE RER JET DYNAMICS OVERTOPPING A
SEASONABLY STRONG COLD FRONT. STILL SOME MINOR TIMING DIFFERENCES
WITH ALL THE ABOVE...BUT OVERALL A PRETTY WELL AGREED UPON FORECAST.
NO DOUBT A MODEL CONSENSUS WILL SUFFICE...FEATURING POSSIBLE SHOWERS
AND STORMS THROUGH THE WEEKEND...WITH THE GREATEST POTENTIAL
OVERNIGHT SATURDAY INTO EARLY SUNDAY. MUCH TOO EARLY TO GET CAUGHT
UP IN INSTABILITY PROGS AND SPECIFIC MID LEVEL WIND CORES...BUT FROM
A PATTERN RECOGNITION STANDPOINT...THIS SYSTEM LOOKS TO HAVE THE
POTENTIAL TO DRIVE A RATHER VIGOROUS (SEVERE?) SQUALL LINE THROUGH
AT LEAST A PORTION OF THE LAKES REGION. FRONTAL TIMING (CURRENT
TRENDS SUPPORT AN UNFAVORABLE EARLY SUNDAY MORNING FRONTAL PASSAGE)
MIGHT NOT EVEN MATTER MUCH GIVEN SUGGESTED DYNAMICS. DEFINITELY
SOMETHING TO MONITOR IN THE COMING DAYS. DRY WEATHER RETURNS FOR THE
BEGINNING OF NEXT WORK WEEK WITH AN AGGRESSIVE PUSH OF HIGH PRESSURE
BUILDING IN BEHIND THE DEPARTING FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 145 AM EDT WED AUG 1 2012
MAINLY VFR CONDITIONS ARE EXPECTED THRU WEDNESDAY EVENING AS HIGH
PRESSURE BUILDS INTO MICHIGAN. FOG WILL CONTINUOUSLY IMPACT MBL
AND LIKELY PLN OVER THE NEXT HOUR OR SO...EVEN TVC HAS A DECENT
SHOT WITH HIGH PRESSURE AND LIGHT WINDS AND SMALL TEMP/DEW POINT
SPREADS. LAKE BREEZES WILL DEVELOP BY WEDNESDAY AFTERNOON. OUR
NEXT CHANCE OF SHRA/TSRA WILL DEVELOP LATE WEDNESDAY NIGHT AS A
WEAK FRONT DROPS INTO NRN MICHIGAN. STILL APPEARS BETTER CHANCES
OF PRECIP WILL HOLD OFF UNTIL AFTER 06Z THURSDAY...THUS WILL LEAVE
PRECIP CHANCES OUT OF TAFS FOR NOW.
&&
.MARINE...
ISSUED AT 348 AM EDT WED AUG 1 2012
HIGH PRESSURE WILL SLIP SOUTH AND EAST OF THE REGION
TODAY...ALLOWING A SOUTHERLY AND INCREASING WIND FLOW TO
REINTRODUCE A HIGHER MOISTURE CONTENT TO THE GREAT LAKES. A COLD
FRONT ARRIVING LATE TONIGHT WILL WORK ON THIS AIR MASS AND BRING A
CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS TO THE AREA. THE
PRESSURE GRADIENT TIGHTENS UP ENOUGH IN A NEUTRAL STABILITY
SCENARIO FOR A CHANCE AT LOW END SMALL CRAFT ADVISORIES LATER
TONIGHT. WILL NOT INTRODUCE THIS JUST YET...BUT COASTAL CONVERGENT
REGIONS OF NW LOWER MICHIGAN WILL BE THE BEST SHOT AT +25KT GUSTS.
THIS FRONT CONTINUES TO DIVE SOUTH OF US INTO THURSDAY...BEFORE
LIFTING BACK AS A WARM FRONT LATE FRIDAY NIGHT AND INTO THE
WEEKEND. NO OTHER WIND ISSUES ARE FORESEEN THROUGH THE WORK
WEEK...BUT ADVISORIES MAY BE NEEDED FOR THE WEEKEND AHEAD OF NEXT
MORE POTENT COLD FRONT...BOTH AHEAD OF AND BEHIND THIS BOUNDARY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MB
SHORT TERM...SD
LONG TERM...MB
AVIATION...MR
MARINE...SD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
309 PM CDT WED AUG 1 2012
.DISCUSSION...
STRONG CONVECTION CONTINUES ACROSS PORTIONS OF NORTHERN WI AT MID
AFTERNOON AHEAD OF A SHORT WAVE OVER NORTHERN MN. MORE CONVECTION
IS EXPECTED LATE THIS AFTERNOON AND EVENING ALONG A COLD FRONT
STRETCHING FROM THE ARROWHEAD OF MN TO CENTRAL SD. THIS CONVECTION
WILL LIKELY HAVE SOME BOUTS OF SEVERE WEATHER WITH LARGE HAIL AND
DAMAGING WINDS. THE WIND THREAT HAS ME MOST CONCERNED WITH DCAPE
VALUES CURRENTLY 1500-1800 J/KG. IN ADDITION... THE RIGHT ENTRANCE
REGION OF A 100+ KNOT JET WILL BE PASSING ACROSS CENTRAL MN EARLY
TONIGHT.
THE FRONT WILL PROGRESS EAST AND SOUTH OF THE FA OVERNIGHT WITH
LINGERING SHOWERS OVER FAR SOUTHERN MN AND WEST CENTRAL WI. THERE
IS SOME CONCERN THAT A SECOND SHORT WAVE OVER WESTERN ND MAY CAUSE
SOME SHOWERS OVER CENTRAL MN DURING THE OVERNIGHT HOURS. A PERIOD
OF DRY WEATHER IS FORECAST FOR MUCH OF THURSDAY AND THURSDAY NIGHT
AS HIGH PRESSURE PASSES ACROSS THE UPPER MISSISSIPPI VALLEY.
A MUCH STRONGER SHORT WAVE AND FRONTAL SYSTEM WILL MOVE ACROSS THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY FROM FRIDAY THROUGH
SATURDAY. VIRTUALLY ALL SOLUTIONS HAVE A CLOSED H5 LOW PASSING
ALONG THE INTERNATIONAL BORDER. THE THREAT FOR SEVERE WEATHER WILL
BE ON THE RISE FRIDAY AFTERNOON IN FAR WESTERN MN AND ACROSS THE
REST OF THE FA FRIDAY NIGHT. AT THIS TIME... CONFIDENCE IS
HIGHEST FOR SEVERE WEATHER FROM WEST CENTRAL MN INTO NORTHERN
AREAS OF THE STATE FRIDAY AFTERNOON AND EVENING WHEN CONSIDERING
SHEAR VALUES... THE LOW LEVEL JET AND THE DIFFERENTIAL TEMPERATURE
ADVECTION SCHEME.
SOME SHOWERS WILL LINGER ON SATURDAY IN THE COLD TROUGH ALOFT
ACROSS THE FA. A PERIOD OF DRY WEATHER IS EXPECTED OR SUNDAY AND
MONDAY ALONG WITH TEMPERATURES MUCH CLOSER TO SEASONAL NORMALS. IN
FACT... I HAVE MSP FORECAST BELOW 80 DEGREES FOR THE HIGH ON
SUNDAY... THIS WOULD BE THE FIRST TIME SINCE JUNE 25TH. A WEAK COLD
FRONT WILL DRIFT SOUTHEAST ACROSS THE REGION MONDAY NIGHT AND
TUESDAY WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE... ALTHOUGH
CONFIDENCE IS NOT HIGH ON COVERAGE AT THIS TIME. A COOL NORTHWEST
FLOW WILL END THE FORECAST PERIOD NEXT WEDNESDAY WITH HIGHS AGAIN
FORECAST BELOW THE 80 DEGREE MARK IN MANY AREAS OF THE FA.
&&
.AVIATION... /18Z TAF ISSUANCE/
COMPLEX OF TSRA THAT DEVELOPED IN WC MN EARLIER THIS MORNING AND
MOVED EASTWARD...HAS NEARLY DISSIPATED ACROSS EC MN AND WC WI.
HOWEVER...THE LEFTOVER BOUNDARY HAS CREATED MORE TSRA NEAR
MADISON/MONTEVIDEO AS OF 12 NOON.
AS A SFC LOW DEVELOPS ACROSS CENTRAL SD...AND THE COOL
FRONT/OUTFLOW BOUNDARY HOLDS ON ACROSS SOUTHERN MN...SHRA/TSRA
WILL LIKELY DEVELOP ALONG IT. TIMING REMAINS THE PROBLEM WITH THE
LATEST HRRR INDICATING ARND 21-22Z WHERE TSRA DEVELOP ALONG A LINE
FROM MONTEVIDEO TO THE TWIN CITIES. SINCE TSRA HAVE ALREADY
DEVELOPED IN WC MN...EXPECT THE HRRR HAS A RELATIVELY GOOD HANDLE
ON CONVECTION DEVELOPING THIS AFTN. WILL LIKELY HIGHLIGHT THE BEST
TIME PERIOD OF TSRA AT RWF/MSP/EAU BETWEEN 21-01Z. AFT THIS
ACTIVITY MOVES SOUTH OF MPX TAF SITES...EXPECT MORE DEVELOPMENT
LATER THIS EVENING/OVERNIGHT AS THE MAIN SHRTWV AND A STRONG JET
INTERACTS WITH THE SLOWLY MOVING COOL FRONT IN FAR SOUTHERN MN.
WILL BEGIN TO INTRODUCE VCSH FOR MOST LOCATIONS STARTING AFT
3Z...WITH TRENDS OF THE SHRA MOVING TO THE S/SE OVERNIGHT. THERE
COULD BE PERIODS OF IFR/MVFR CIGS/VSBYS...ESPECIALLY THIS
AFTERNOON IF THE COMPLEX OF TSRA BECOMES MORE WIDESPREAD ACROSS S
MN. WILL CONTINUE WITH VFR CIGS...AND MVFR VSBYS IN TSRA. LATER
SHIFTS CAN UPDATE IF NEEDED. WNDS WILL EVENTUALLY SHFT TO THE N/NE
OVERNIGHT...BUT REMAIN BELOW 10 KTS.
MSP...BELIEVE THE BEST POTENTIAL OF MVFR/IFR CIGS/VSBYS WILL OCCUR
FROM 21-01Z AS A COMPLEX OF TSRA DEVELOPS ACROSS S MN. TIMING AND
HOW WIDESPREAD THIS ACTIVITY BECOMES REMAINS THE CONCERN/QUESTION.
WILL CONTINUE WITH MVFR VSBYS IN TSRA...AND VFR CIGS. WNDS WILL
SLOWLY BECOME W...THEN NW BY THIS EVENING AS THE COOL FRONT SAGS
SOUTHWARD. LATER TONIGHT WINDS WILL BE MORE FROM THE N/NE AND
CONTINUE THRU THE TAF PERIOD.
OUTLOOK...
THURSDAY...VFR. WINDS N AT 5G10KTS.
FRIDAY...VFR DURING THE DAY. EVENING MVFR/IFR CONDITIONS LIKELY IN
SHWRS/TSTMS. WIND SE AT 10G20KTS.
SATURDAY...VFR/MVFR WITH SHWRS/TSTMS POSSIBLE EARLY. WINDS W AT
10G20KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1212 PM CDT WED AUG 1 2012
.DISCUSSION...
OVERVIEW...FEW THINGS TO SORT OUT THIS MORNING. RAISED TEMPS
TODAY...SEEMS WE HAVE UNDERESTIMATED THE WARMING POTENTIAL THE
PAST COUPLE DAYS. CHANCE TO LIKELY POPS THIS AFTERNOON AND EVENING
WITH A SLIGHT RISK OF SEVERE WEATHER FOR WIND AND HAIL...BUT
CAPPING REMAINS A CONCERN. UPPER LOW...THUNDERSTORMS...AND A
COOLING TREND STILL ON TAP LATE IN THE WEEK.
COUPLE FEATURES OF NOTE ON THE MORNING SATELLITE IMAGERY. CONTINUE
TO WATCH AN AREA OF CONVECTION IN SD FALL APART WITH CONTINUED
WARMING CLOUD TOPS. HOWEVER...THINK THE MORE INTERESTING
DEVELOPMENT IS SOME ALTO CU JUST NORTH OF THIS AREA MOVING INTO
EASTERN ND AND WESTERN MN THIS MORNING. THIS IS TIED TO THE STRONG
WARM AIR ADVECTION AND WE ARE OBVIOUSLY GETTING ENOUGH ISENTROPIC
LIFT TO GET US NEAR SATURATION. INCLUDED SMALL POPS ACROSS
NORTHERN FORECAST AREA BETWEEN 15-18Z TO ACCOUNT FOR POSSIBILITY
OF ELEVATED SHOWERS. 00Z NAM AND EC REFLECT THIS IN THE FIRST
12-15 HOURS OF THE FORECAST. PROBABLY THE MORE IMPORTANT QUESTION
IS WHEN AND WHERE SHOWERS/STORMS INITIATE THIS AFTERNOON OR
EVENING. WE PULLED POPS OUT OF THE 12-18Z IN MOST LOCATIONS...AND
STILL SOME SERIOUS QUESTION ABOUT EARLY DEVELOPMENT BETWEEN 18-22Z
WITH THE STRONG WARMING AND CAPPING TODAY. THE 00Z SOUNDING AT MPX
HAD +16C AT 850MB...BUT EXPECT THE 12Z SOUNDING TO LOOK MORE LIKE
THE 00Z ABR SOUNDING WITH +20C TO +23C...ABR WAS ACTUALLY +24.
THINK MORE LIKELY PERIOD FOR STORM INITIATION WILL BE AFTER 22Z
WHEN BOTH NAM/GFS ERODE MOST OF THE CAPPING. WE WILL BE ON THE
SOUTHERN FRINGE OF BEST MID LEVEL FLOW...SO SHEAR WILL BE MARGINAL
FOR ORGANIZATION. HOWEVER...WITH THE EXPECTED WARMING AND MODEST
LOW LEVEL MOISTURE AND STEEP LAPSE RATES...WE WILL HAVE VERY HIGH
CAPE VALUES. SO STRONG UPDRAFTS WITH WIND AND HAIL ARE POSSIBLE
ASSUMING THE CAP DOES INDEED GIVE WAY. THINK IT WILL BY THIS
EVENING. MESO MODEL GUIDANCE FAVORS SOUTHERN MN.
MEANWHILE...WITH 850MB TEMPS THAT WARM AND WHAT SHOULD BE A WELL
MIXED ATMOSPHERE TO GO ALONG WITH PLENTY OF SUN EARLY...THERE
SHOULD BE SOME SERIOUS HEAT TODAY. HAVE TO LIKE THE STRONG W-SW
FLOW TODAY. IN FACT...INCREASED WINDS THIS AFTERNOON. BUMPED HIGHS
TODAY BY 2-4 DEGREES AND HAVE 96 FOR THE TWIN CITIES METRO. THE
NAM IS QUITE AGGRESSIVE AND HAS CLOSE TO OR HIGHER THAN 100 IN MANY
SPOTS. THE GFS IS AS ALWAYS TOO COOL. THE FORECAST HIGHS TODAY ARE
PROBABLY CLOSEST TO THE EC...BUT A DEGREE OR SO HIGHER THAN THE EC
OVERALL. JUST HOPE I DONT WAKE UP AT 1 PM AFTER THIS MID NIGHT
SHIFT AND SEE SITES ALREADY REPORTING MID 90S...WITH HIGHS
EVENTUALLY IN THE UPPER 90S. NOT OUT OF THE QUESTION GIVEN THE
BACKWARD TRAJECTORIES SUGGESTING A FEED OF AIR FROM NEBRASKA WHERE
HIGHS WHERE IN THE MID TO UPPER 90S YESTERDAY.
SYSTEM ON FRIDAY HAS THE POTENTIAL FOR WIDESPREAD THUNDERSTORMS
AND WHAT LOOKS LIKE THE BEST SEVERE THREAT WE HAVE HAD IN A WHILE.
FAVORABLE UPPER FLOW PATTERN WITH THE SUBTROPICAL AND POLAR JETS
COMING TOGETHER AND GOOD THICKNESS DIFFLUENCE OUT AHEAD OF THE
UPPER LOW AND COOLING HEIGHTS SUGGEST LIKELY POPS. THERE WILL ALSO
BE NICE OVERLAP OF SHEAR AND INSTABILITY. GFS HAS 40-55KTS AT
500MB BY 06Z SATURDAY TO GO ALONG WITH 2000-2500 J/KG OF MUCAPE.
THE UPPER LOW LOOKS MORE LIKE SOMETHING TYPICALLY OBSERVED IN
SEPT/OCT...BUT WITH AUGUST WARMTH. A LITTLE WARM AT
850-700MB...BUT 9-11C AT 700MB IS NOT A SHOW STOPPER BY ANY MEANS.
PRIMARY AREA OF FOCUS IS IN CENTRAL MN AND NORTHWEST WI.
&&
.AVIATION.../18Z TAF ISSUANCE/
COMPLEX OF TSRA THAT DEVELOPED IN WC MN EARLIER THIS MORNING AND
MOVED EASTWARD...HAS NEARLY DISSIPATED ACROSS EC MN AND WC WI.
HOWEVER...THE LEFTOVER BOUNDARY HAS CREATED MORE TSRA NEAR
MADISON/MONTEVIDEO AS OF 12 NOON.
AS A SFC LOW DEVELOPS ACROSS CENTRAL SD...AND THE COOL
FRONT/OUTFLOW BOUNDARY HOLDS ON ACROSS SOUTHERN MN...SHRA/TSRA
WILL LIKELY DEVELOP ALONG IT. TIMING REMAINS THE PROBLEM WITH THE
LATEST HRRR INDICATING ARND 21-22Z WHERE TSRA DEVELOP ALONG A LINE
FROM MONTEVIDEO TO THE TWIN CITIES. SINCE TSRA HAVE ALREADY
DEVELOPED IN WC MN...EXPECT THE HRRR HAS A RELATIVELY GOOD HANDLE
ON CONVECTION DEVELOPING THIS AFTN. WILL LIKELY HIGHLIGHT THE BEST
TIME PERIOD OF TSRA AT RWF/MSP/EAU BETWEEN 21-01Z. AFT THIS
ACTIVITY MOVES SOUTH OF MPX TAF SITES...EXPECT MORE DEVELOPMENT
LATER THIS EVENING/OVERNIGHT AS THE MAIN SHRTWV AND A STRONG JET
INTERACTS WITH THE SLOWLY MOVING COOL FRONT IN FAR SOUTHERN MN.
WILL BEGIN TO INTRODUCE VCSH FOR MOST LOCATIONS STARTING AFT
3Z...WITH TRENDS OF THE SHRA MOVING TO THE S/SE OVERNIGHT. THERE
COULD BE PERIODS OF IFR/MVFR CIGS/VSBYS...ESPECIALLY THIS
AFTERNOON IF THE COMPLEX OF TSRA BECOMES MORE WIDESPREAD ACROSS S
MN. WILL CONTINUE WITH VFR CIGS...AND MVFR VSBYS IN TSRA. LATER
SHIFTS CAN UPDATE IF NEEDED. WNDS WILL EVENTUALLY SHFT TO THE N/NE
OVERNIGHT...BUT REMAIN BELOW 10 KTS.
MSP...BELIEVE THE BEST POTENTIAL OF MVFR/IFR CIGS/VSBYS WILL OCCUR
FROM 21-01Z AS A COMPLEX OF TSRA DEVELOPS ACROSS S MN. TIMING AND
HOW WIDESPREAD THIS ACTIVITY BECOMES REMAINS THE CONCERN/QUESTION.
WILL CONTINUE WITH MVFR VSBYS IN TSRA...AND VFR CIGS. WNDS WILL
SLOWLY BECOME W...THEN NW BY THIS EVENING AS THE COOL FRONT SAGS
SOUTHWARD. LATER TONIGHT WINDS WILL BE MORE FROM THE N/NE AND
CONTINUE THRU THE TAF PERIOD.
OUTLOOK...
THURSDAY...VFR. WINDS N AT 5G10KTS.
FRIDAY...VFR DURING THE DAY. EVENING MVFR/IFR CONDITIONS LIKELY IN
SHWRS/TSTMS. WIND SE AT 10G20KTS.
SATURDAY...VFR/MVFR WITH SHWRS/TSTMS POSSIBLE EARLY. WINDS W AT
10G20KTS. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/JLT
AREA FORECAST DISCUSSION
NWS DULUTH MN
646 AM CDT WED AUG 1 2012
.AVIATION...12Z TAFS.
UNSTABLE ATMOSPHERE IN PLACE IS ALLOWING CU/TCU TO FORM AHEAD OF
FRONT IN NW MN. ALREADY A STORM HAS FIRED NEAR DTL AND HAVE A
VCTS AT BRD AS THIS CELL IS MOVING E. WAA WILL MAKE ADDITIONAL
DEVELOPMENT DIFFICULT TO TIME. HAVE ADDED VCSH AFTER 01Z TO
HYR/DLH/HIB/INL AHEAD OF SECOND FRONT EXPECTED NEAR THE CANADIAN
BORDER. VFR IS EXPECTED THROUGHOUT...EVEN IN THE VCNTY OF STORMS.
&&
.PREV DISCUSSION... /ISSUED 337 AM CDT WED AUG 1 2012/
SHORT TERM...
TODAY THROUGH THURSDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL
FOR SHOWERS AND THUNDERSTORMS TODAY...WITH A SLIGHT RISK OF STRONG
TO SEVERE STORMS SOUTH OF A LINE FROM HINCKLEY TO ASHLAND...ALONG
WITH VERY WARM AND HUMID CONDITIONS TODAY...AND A FEW SHOWERS AND
STORMS POSSIBLE ACROSS THE ARROWHEAD TOMORROW.
SURFACE HIGH PRESSURE AND DRY CONDITIONS ARE DOMINATING MUCH OF
THE WRN GREAT LAKES REGION THIS MORNING...WITH THE HIGH CENTERED
OVER CENTRAL WI. A LARGE UPPER LOW IS SITUATED OVER HUDSON BAY AND
AN UPPER HIGH IS POSITIONED OVER THE SRN PLAINS. A COUPLE WEAK
SHORT WAVES ARE RIDING IN BETWEEN THESE TWO FEATURES ACROSS THE
NRN PLAINS AND UPPER MIDWEST. A SFC LOW IS LOCATED OVER SRN
MANITOBA WITH A STATIONARY/WARM FRONT EXTENDING EWD INTO NRN
ONTARIO AND A TROUGH/COLD FRONT DROPPING SOUTH INTO THE DAKOTAS.
THIS LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EWD INTO THE
NORTHLAND TODAY AND EVENTUALLY TRIGGER SHOWERS AND STORMS ALONG
AND AHEAD OF THE FRONT.
THERE ARE SIGNIFICANT MODEL DIFFERENCES REGARDING THE CONVECTIVE
INITIATION THIS AFTERNOON...WITH THE 00Z GFS NAM AND ECMWF BEING
FAIRLY MORE AGGRESSIVE THAN THE 00Z GEM AND LATEST 06Z NAM. THE
MORE AGGRESSIVE MODELS ARE NOT INITIALIZING VERY WELL LOOKING AT
CURRENT REGIONAL RADAR...SO CONFIDENCE IN CHC POPS/SCT SHOWERS AND
STORMS IS MUCH WEAKER. UPPER LEVEL SUPPORT IS NOT REALLY EVIDENT
WITH A WEAK JET AND MINIMAL 500MB PVA. THE LOW LEVELS WILL BECOME
QUITE UNSTABLE WITH ML CAPE VALUES OVER 2000 J/KG AND 0-6KM SHEAR
AROUND 30 KT...ALONG WITH STEEP LAPSE RATES...WHICH WILL PROVIDE
THE NECESSARY INGREDIENTS FOR STRONG CONVECTION. SO...WILL LIKELY
SEE SHOWERS AND WEAK STORMS INITIATE ACROSS NE MN INTO CENTRAL MN
AND MOVE E/SEWD WITH THE FRONT AND POSSIBLY INTERACT WITH AN
INCREASINGLY UNSTABLE ATMOSPHERE TO PRODUCE A FEW STRONG TO
POSSIBLY SEVERE STORMS OVER THE SERN SECTIONS OF THE CWA...MAINLY
IN NW WI. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS.
CHECK THE LATEST DAY 1 CONVECTIVE OUTLOOK FROM SPC FOR FURTHER
INFORMATION.
THE OTHER CONCERN TODAY WILL BE THE HOT AND HUMID CONDITIONS ONCE
AGAIN. WE JUST ENDED THE SECOND WARMEST JULY ON RECORD IN DULUTH
YESTERDAY...AND NOW WE ARE STARTING OFF AUGUST ON A WARM NOTE AS
WELL. HIGHS WILL CLIMB INTO THE MID TO UPPER 80S WITH DEW POINTS
INTO THE MID TO UPPER 60S. THIS WILL CAUSE HEAT INDICES TO ROCKET
INTO THE LOWER TO MID 90S. TAKE THE NECESSARY PRECAUTIONS IF
OUTSIDE TODAY.
WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE DEPARTING SYSTEM
TONIGHT AND ALLOW CONDITIONS TO DRY OUT RAPIDLY. ANOTHER WEAK
UPPER WAVE SLIDES IN FROM THE NW TOMORROW AFTERNOON AND INTERACTS
WITH A WEAKLY UNSTABLE ATMOSPHERE TO TRIGGER OFF A FEW ISOLATED
STORMS ACROSS THE ARROWHEAD. AT THIS TIME CONFIDENCE IS LOW IN
PRECIP ON THURSDAY AFTERNOON. TEMPERATURES WILL BE SLIGHTLY COOLER
ON THURSDAY WITH LOWER...MORE COMFORTABLE HUMIDITIES. HIGHS WILL
ONLY REACH INTO THE LOWER TO MID 80S.
LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
SFC RIDGING OVER THE EASTERN GREAT LAKES WILL KEEP THE FA DRY
THURSDAY NIGHT. ON FRIDAY...A LARGE CUT OFF UPPER LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE CANADIAN PLAINS. THIS WILL PUSH A SFC
LOW CENTER OVER THE NORTHERN RED RIVER VALLEY IN CANADA WHILE A SFC
FRONT MOVES INTO THE RED RIVER VALLEY. PLENTY OF LOW LEVEL MOISTURE
WILL BE TRANSPORTED INTO THE FA AHEAD OF THE FRONT. SHOWERS AND
STORMS WILL FORM AHEAD OF THE FRONT AND OVERSPREAD THE FA THROUGH
FRIDAY NIGHT. THE COLD FRONT DEPARTS THE FA ON SATURDAY AS THE SFC
LOW OPENS UP AND THE UPPER LOW CONTINUES TO DRIVE EASTWARD THROUGH
SOUTH CENTRAL CANADA. A SECONDARY COLD FRONT WITH COLDER AIR ALOFT
FOLLOWS BEHIND AND CROSS THE FA SATURDAY NIGHT. SOME ISOLD
THUNDERSTORMS WILL ACCOMPANY THIS FRONT. A DRY PERIOD FOLLOWS FOR
SUNDAY THROUGH WEDNESDAY AS UPPER LEVEL/SFC RIDGING COVER THE
WESTERN GREAT LAKES.
AVIATION.../06Z TAF ISSUANCE/
PULLED OUT THE LLWS OVERNIGHT AS LATEST NAM BUFR SOUNDINGS SHOW
WIND SPEEDS UNDER 30 KNOTS BELOW 2000 FT AGL. ALSO SHIFTED THE
TIMING OF VCTS TO THE MORNING HOURS AS LATEST HRRR REFLECTIVITY
BRINGS IN SOME THUNDER AFTER 10Z ACROSS THE WESTERN AERODROMES.
A COLD FRONT WILL PASS THROUGH THE TERMINALS BY 18Z THAT WILL
BRING IN WESTERLY WINDS WITH A FEW GUSTS NEARING 20 KNOTS. WINDS
WILL DIMINISH BEFORE SUNSET AND COME FROM THE NORTHWEST.
&&
.POINT TEMPS/POPS...
DLH 87 64 80 57 / 40 30 10 0
INL 86 57 79 56 / 30 10 20 0
BRD 89 64 84 60 / 40 20 10 0
HYR 89 62 84 58 / 30 40 10 0
ASX 89 64 82 59 / 40 40 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
337 AM CDT WED AUG 1 2012
.SHORT TERM...
TODAY THROUGH THURSDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL
FOR SHOWERS AND THUNDERSTORMS TODAY...WITH A SLIGHT RISK OF STRONG
TO SEVERE STORMS SOUTH OF A LINE FROM HINCKLEY TO ASHLAND...ALONG
WITH VERY WARM AND HUMID CONDITIONS TODAY...AND A FEW SHOWERS AND
STORMS POSSIBLE ACROSS THE ARROWHEAD TOMORROW.
SURFACE HIGH PRESSURE AND DRY CONDITIONS ARE DOMINATING MUCH OF
THE WRN GREAT LAKES REGION THIS MORNING...WITH THE HIGH CENTERED
OVER CENTRAL WI. A LARGE UPPER LOW IS SITUATED OVER HUDSON BAY AND
AN UPPER HIGH IS POSITIONED OVER THE SRN PLAINS. A COUPLE WEAK
SHORT WAVES ARE RIDING IN BETWEEN THESE TWO FEATURES ACROSS THE
NRN PLAINS AND UPPER MIDWEST. A SFC LOW IS LOCATED OVER SRN
MANITOBA WITH A STATIONARY/WARM FRONT EXTENDING EWD INTO NRN
ONTARIO AND A TROUGH/COLD FRONT DROPPING SOUTH INTO THE DAKOTAS.
THIS LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EWD INTO THE
NORTHLAND TODAY AND EVENTUALLY TRIGGER SHOWERS AND STORMS ALONG
AND AHEAD OF THE FRONT.
THERE ARE SIGNIFICANT MODEL DIFFERENCES REGARDING THE CONVECTIVE
INITIATION THIS AFTERNOON...WITH THE 00Z GFS NAM AND ECMWF BEING
FAIRLY MORE AGGRESSIVE THAN THE 00Z GEM AND LATEST 06Z NAM. THE
MORE AGGRESSIVE MODELS ARE NOT INITIALIZING VERY WELL LOOKING AT
CURRENT REGIONAL RADAR...SO CONFIDENCE IN CHC POPS/SCT SHOWERS AND
STORMS IS MUCH WEAKER. UPPER LEVEL SUPPORT IS NOT REALLY EVIDENT
WITH A WEAK JET AND MINIMAL 500MB PVA. THE LOW LEVELS WILL BECOME
QUITE UNSTABLE WITH ML CAPE VALUES OVER 2000 J/KG AND 0-6KM SHEAR
AROUND 30 KT...ALONG WITH STEEP LAPSE RATES...WHICH WILL PROVIDE
THE NECESSARY INGREDIENTS FOR STRONG CONVECTION. SO...WILL LIKELY
SEE SHOWERS AND WEAK STORMS INITIATE ACROSS NE MN INTO CENTRAL MN
AND MOVE E/SEWD WITH THE FRONT AND POSSIBLY INTERACT WITH AN
INCREASINGLY UNSTABLE ATMOSPHERE TO PRODUCE A FEW STRONG TO
POSSIBLY SEVERE STORMS OVER THE SERN SECTIONS OF THE CWA...MAINLY
IN NW WI. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS.
CHECK THE LATEST DAY 1 CONVECTIVE OUTLOOK FROM SPC FOR FURTHER
INFORMATION.
THE OTHER CONCERN TODAY WILL BE THE HOT AND HUMID CONDITIONS ONCE
AGAIN. WE JUST ENDED THE SECOND WARMEST JULY ON RECORD IN DULUTH
YESTERDAY...AND NOW WE ARE STARTING OFF AUGUST ON A WARM NOTE AS
WELL. HIGHS WILL CLIMB INTO THE MID TO UPPER 80S WITH DEW POINTS
INTO THE MID TO UPPER 60S. THIS WILL CAUSE HEAT INDICES TO ROCKET
INTO THE LOWER TO MID 90S. TAKE THE NECESSARY PRECAUTIONS IF
OUTSIDE TODAY.
WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE DEPARTING SYSTEM
TONIGHT AND ALLOW CONDITIONS TO DRY OUT RAPIDLY. ANOTHER WEAK
UPPER WAVE SLIDES IN FROM THE NW TOMORROW AFTERNOON AND INTERACTS
WITH A WEAKLY UNSTABLE ATMOSPHERE TO TRIGGER OFF A FEW ISOLATED
STORMS ACROSS THE ARROWHEAD. AT THIS TIME CONFIDENCE IS LOW IN
PRECIP ON THURSDAY AFTERNOON. TEMPERATURES WILL BE SLIGHTLY COOLER
ON THURSDAY WITH LOWER...MORE COMFORTABLE HUMIDITIES. HIGHS WILL
ONLY REACH INTO THE LOWER TO MID 80S.
.LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
SFC RIDGING OVER THE EASTERN GREAT LAKES WILL KEEP THE FA DRY
THURSDAY NIGHT. ON FRIDAY...A LARGE CUT OFF UPPER LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE CANADIAN PLAINS. THIS WILL PUSH A SFC
LOW CENTER OVER THE NORTHERN RED RIVER VALLEY IN CANADA WHILE A SFC
FRONT MOVES INTO THE RED RIVER VALLEY. PLENTY OF LOW LEVEL MOISTURE
WILL BE TRANSPORTED INTO THE FA AHEAD OF THE FRONT. SHOWERS AND
STORMS WILL FORM AHEAD OF THE FRONT AND OVERSPREAD THE FA THROUGH
FRIDAY NIGHT. THE COLD FRONT DEPARTS THE FA ON SATURDAY AS THE SFC
LOW OPENS UP AND THE UPPER LOW CONTINUES TO DRIVE EASTWARD THROUGH
SOUTH CENTRAL CANADA. A SECONDARY COLD FRONT WITH COLDER AIR ALOFT
FOLLOWS BEHIND AND CROSS THE FA SATURDAY NIGHT. SOME ISOLD
THUNDERSTORMS WILL ACCOMPANY THIS FRONT. A DRY PERIOD FOLLOWS FOR
SUNDAY THROUGH WEDNESDAY AS UPPER LEVEL/SFC RIDGING COVER THE
WESTERN GREAT LAKES.
&&
.AVIATION.../06Z TAF ISSUANCE/
PULLED OUT THE LLWS OVERNIGHT AS LATEST NAM BUFR SOUNDINGS SHOW
WIND SPEEDS UNDER 30 KNOTS BELOW 2000 FT AGL. ALSO SHIFTED THE
TIMING OF VCTS TO THE MORNING HOURS AS LATEST HRRR REFLECTIVITY
BRINGS IN SOME THUNDER AFTER 10Z ACROSS THE WESTERN AERODROMES.
A COLD FRONT WILL PASS THROUGH THE TERMINALS BY 18Z THAT WILL
BRING IN WESTERLY WINDS WITH A FEW GUSTS NEARING 20 KNOTS. WINDS
WILL DIMINISH BEFORE SUNSET AND COME FROM THE NORTHWEST.
&&
.POINT TEMPS/POPS...
DLH 87 64 80 57 / 40 30 10 0
INL 86 57 79 56 / 30 10 20 0
BRD 89 64 84 60 / 40 20 10 0
HYR 89 62 84 58 / 30 40 10 0
ASX 89 64 82 59 / 40 40 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GSF
AVIATION...KK
AREA FORECAST DISCUSSION
NWS DULUTH MN
1225 AM CDT WED AUG 1 2012
.AVIATION.../06Z TAF ISSUANCE/
PULLED OUT THE LLWS OVERNIGHT AS LATEST NAM BUFR SOUNDINGS SHOW
WIND SPEEDS UNDER 30 KNOTS BELOW 2000 FT AGL. ALSO SHIFTED THE
TIMING OF VCTS TO THE MORNING HOURS AS LATEST HRRR REFLECTIVITY
BRINGS IN SOME THUNDER AFTER 10Z ACROSS THE WESTERN AERODROMES.
A COLD FRONT WILL PASS THROUGH THE TERMINALS BY 18Z THAT WILL
BRING IN WESTERLY WINDS WITH A FEW GUSTS NEARING 20 KNOTS. WINDS
WILL DIMINISH BEFORE SUNSET AND COME FROM THE NORTHWEST.
&&
.PREV DISCUSSION... /ISSUED 731 PM CDT TUE JUL 31 2012/
UPDATE...
WE PULLED POPS FOR EARLY THIS EVENING...AND HAVE A SLIGHT CHANCE
FOR A SHOWER/STORM IN THE FAR NORTHWEST LATE THIS EVENING...THEN
CONTINUED TO SPREAD POPS FURTHER EAST AND SOUTH OVERNIGHT.
INITIAL WEAK WAVE THAT COMBINED WITH WAA TO PRODUCE A FEW
SHOWERS/STORMS IN NORTHWEST MN HAS MOVED EAST AND INTO MORE STABLE
AIR. MODELS FORECAST INCREASING LLJ WITH 925MB WINDS INCREASING TO
35-40KT AS FRONT MOVES EAST INTO NORTHWEST MINNESOTA BY 12Z WED.
STABILITY WILL BE DROPPING OVERNIGHT. THERE REALLY ISN`T MUCH OF A
MID LEVEL WAVE TO AID IN LARGER SCALE FORCING TONIGHT...SO THERE
ARE SOME DOUBTS AS TO COVERAGE AND STRENGTH OF THE STORMS
OVERNIGHT. WE WILL KEEP POPS AS IS FOR NOW FOR LATER TONIGHT...AND
WAIT FOR THE LATEST MODELS BEFORE MAKING ANY FURTHER ADJUSTMENT.
PREV DISCUSSION... /ISSUED 624 PM CDT TUE JUL 31 2012/
AVIATION.../0Z TAF ISSUANCE/
MARGINAL LLWS TONIGHT OVER THE PARTS OF THE AREA TONIGHT AND KEPT
THE THREAT OF SOUTHWEST WINDS OF 30 KNOTS UP TO 2000 FT AGL OVER
BRD AND HIB AFTER MIDNIGHT. ANY PATCHY FOG THAT DOES DEVELOP
TONIGHT SHOULD BE LIMITED TO HYR WHERE VISIBILITIES MAY FALL TO
LOW END MVFR RANGE BY DAYBREAK. INCLUDED A TEMPO GROUP AFTER
MIDNIGHT FOR THUNDERSTORMS AT INL AND HAVE VCTS FOR ALL TERMINALS
BY EARLY WEDNESDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 342 PM CDT TUE JUL 31 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT.
SOME HIGH CLOUDS HAVE MOVED ACROSS THE NORTHLAND DURING THE
AFTERNOON ALONG WITH SOME CUMULUS DEVELOPMENT. THERE WERE ALSO A
FEW AREAS OF ELEVATED SMOKE...ONE POTENTIALLY FROM FIRES IN THE
NORTHERN ROCKIES AND ANOTHER FROM CANADIAN FIRES. THERE HAVE BEEN
REPORTS OF PEOPLE SMELLING THE SMOKE AS WELL...SPECIFICALLY IN
NORTHERN WISCONSIN. HIGH TEMPERATURES WERE GENERALLY IN THE LOWER
80S THIS AFTERNOON...BUT WERE A BIT COOLER NEAR THE LAKE.
THE FOCUS FOR TONIGHT WILL BE ON THE CHANCE OF SHOWERS AND
THUNDERSTORMS. IT LOOKS LIKE COVERAGE WILL BE QUITE SPOTTY FOR THE
MOST PART. THE 4 KM NMM WRF ACTUALLY HAS VERY LITTLE IN THE WAY OF
FORECAST SURFACE REFLECTIVITY ACROSS THE AREA OVERNIGHT. THE
CHANCE OF STORMS WILL CONTINUE ON WEDNESDAY ACROSS MUCH OF THE CWA
AS A COLD FRONT/TROUGH DROPS ACROSS THE CWA. THE NAM ACTUALLY
HINTS AT A DECENT COMPLEX OF THUNDERSTORMS DEVELOPING ACROSS EC MN
AND NW WI DURING THE AFTERNOON BUT THE 4 KM NMM WRF SURFACE
REFLECTIVITY KEEPS PRECIPITATION ALONG THE INTERNATIONAL BORDER.
THE GFS IS SIMILAR TO THE NAM AS IS THE ECMWF. AS A RESULT...WE
FEEL THERE WILL BE AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING ACROSS THAT AREA TOMORROW AFTERNOON AND
EVENING...BEFORE DIMINISHING FROM THE NW TO SE. TEMPS SHOULD SOAR
THROUGH THE 80S FOR MOST AREAS...AND HEAT INDEX VALUES ARE
EXPECTED TO BE ABOVE 90 IN AREAS OF THE SOUTH/SE.
LONG TERM...THURSDAY THROUGH TUESDAY...
FRONTAL BDRY WILL SLIDE SOUTH OF REGION THURSDAY WITH ONLY SLIGHT CHC
OF RW/TRW ACROSS ARROWHEAD AND SERN WISC ZONES. STRENGTHENING SFC
HIGH WILL MOVE INTO CTRL ONTARIO FRIDAY WITH WARM ADVECTION REGIME
INCREASING OVER CWA. POPS WILL SPREAD EAST AND INCREASE FRI/SAT AS
AN UPPER TROF/SFC LOW INTENSIFY ALONG INTERNATIONAL BORDER JUST WEST
OF CWA. HIGHEST POPS WOULD APPEAR TO BE FRI NIGHT AS MAIN MSTR
TRANSPORT AXIS SHIFTS ACROSS THE AREA. OCCLUDED FRONT WILL MOVE
ACROSS THE REGION SATURDAY...WITH THE UPPER TROF LAGGING BEHIND SFC
FEATURE . EXPECT RESIDUAL POPS AS CONVECTIVE INSTABILITY REMAINS
SUFFICIENT WITHIN A FAIRLY DEEP CYCLONIC CIRCULATION. GRADUAL
DECREASE IN PRECIP FROM WEST TO EAST SUNDAY AS SFC HIGH IS FINALLY
ALLOWED TO BUILD INTO THE REGION UNDERNEATH A PROGRESSIVE FLOW
ALOFT. SFC HIGH THEN SHIFTS EAST MONDAY WITH RETURN FLOW
DEVELOPING. AT THE SAME TIME...MID LVL RIDGE IS FCST TO AMPLIFY
OVERHEAD. DESPITE SOME INCREASE IN MSTR TRANSPORT HAVE COLLABORATED
WITH SURROUNDING OFFICES TO LEAVE POPS OUT OF FCST FOR NOW AS VERY
LARGE POOL OF MID LVL WARM AIR ADVECTS INTO CWA MAKING CONVECTIVE
POTENTIAL QUITE LIMITED. CURRENT FCST MAX TEMPS BASED ON CONSENSUS
BLEND OF NWP WITH HEAVIER WEIGHTING TO 0Z EC. LATEST EC
SIGNIFICANTLY WARMER SO SUSPECT NEXT UPDATE WILL INCREASE MAX TEMPS
MON AND ESPECIALLY TUESDAY.
&&
.POINT TEMPS/POPS...
DLH 65 86 63 81 / 30 40 30 10
INL 64 87 59 80 / 50 40 20 10
BRD 65 90 64 84 / 30 40 20 10
HYR 56 89 65 84 / 0 30 40 10
ASX 58 89 65 82 / 10 30 40 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...KK
AREA FORECAST DISCUSSION
NWS JACKSON MS
1015 AM CDT WED AUG 1 2012
.UPDATE...CLEAR SKIES ACROSS THE ARKLAMISS THIS MORNING FOR THE MOST
PART AS WEAK HIGH PRESSURE PREVAILS. THE GFS/NAM INDICATE A PRETTY
STRONG WAVE MOVING SOUTHEAST ACROSS THE ARKLAMISS THIS MORNING AND
THIS COMBINED WITH AROUND 2.0 INCH PWATS SHOULD KICK OF SOME
ISOLATED TO SCATTERED THUNDERSTORMS WITH THE BEST CHANCES ALONG AND
NORTH OF I-20 THIS AFTERNOON. THE LOCAL WRF MODEL AND HRRR ALSO
INDICATE THIS..SO WILL UP POPS A TOUCH THIS AFTERNOON FOR THE ABOVE
MENTIONED AREAS. ALSO MADE MINOR ADJUSTMENTS TO TEMPS WITH THE
UPDATES ARE ALREADY OUT./15/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
THE PRIMARY CONCERNS WILL BE THE CONTINUED EXCESSIVE HEAT POTENTIAL
FOR THE REGION THROUGH THE PERIOD AS WELL AS THE POTENTIAL FOR A
FEW SPOTTY STRONG TO SEVERE STORMS.
LATEST SATELLITE IMAGERY SHOWED A MUCH LESS ACTIVE PATTERN THAN WAS
NOTED YESTERDAY MORNING. IT STILL SHOWED A SERIES OF WEAK
DISTURBANCES MOVING FROM THE CENTRAL PLAINS SOUTHEASTWARD THROUGH
THE MISSISSIPPI VALLEY REGION. THIS WAS AROUND THE MEAN MID TO UPPER
LEVEL RIDGE CENTERED OVER THE SOUTHERN PLAINS. AREA RADARS WERE
PRETTY QUIET ON CONVECTIVE ACTIVITY THIS MORNING. TEMPS ARE DOING A
LITTLE BETTER THIS MORNING IN THE EAST WITH LOWER TO MIDDLE
70S...WHILE THE WEST HALF WAS STILL IN THE UPPER 70S TO LOWER 80S AS
OF 3 AM. A WEAK SURFACE BOUNDARY WAS NOTED ACROSS THE EXTREME NORTH.
A CHALLENGING FORECAST IN THE TOUGH TIMING OF THE DISTURBANCES
COMING DOWN IN NORTHERLY FLOW FOR TODAY THROUGH THURSDAY NIGHT
AROUND THE DOMINANT MID TO UPPER RIDGE CENTERED OVER THE SOUTHERN
PLAINS. MODELS HAVE BEEN HAVING A TOUGH TIME WITH THIS. HAD AN
ISOLATED SEVERE STORM IN THE SOUTHEAST YESTERDAY AFTERNOON. STILL
THINK THAT THE WEAK DISTURBANCES WILL TRIGGER ISOLATED STRONG TO
SEVERE STORMS FOR TODAY...WHICH CAN REALLY FLARE UP DUE TO DAY TIME
HEATING...INSTABILITY...AND STRONG UPPER NORTHERLY FLOW OF 35-45
KNOTS AT 200-300 MB. THE FLOW WILL BE WEAKER ON THURSDAY...BUT STILL
HAVE SOME DECENT INSTABILITY. NORTHWEST FLOW WILL BE MORE PRONOUNCED
ACROSS THE REGION...SO THESE STRONG ISOLATED STORMS COULD OCCUR
ANYWHERE THROUGH TONIGHT. MOISTURE CONVERGENCE WILL BE PRETTY GOOD
ACROSS THE REGION WHERE ANY ISOLATED STORMS DEVELOP. WITH THIS HEAT
WE WILL HAVE GOOD MICROBURST POTENTIAL THE PRIMARY RISK WILL BE
GUSTY WINDS OF 50 TO 60 MPH. THE TIMING OF THESE DISTURBANCES COULD
HAPPEN ANYTIME DURING THE DAY OR NIGHT...WHICH IS EVIDENT BY LATEST
SATELLITE IMAGERY. PWATS WILL BE AROUND 1.5-2.0 INCHES.
AS FAR AS HEAT POTENTIAL IS CONCERN MODELS SHOW THAT THE EXCESSIVE
HEAT POTENTIAL WILL CONTINUE...WITH NO REAL RECOVERY AT NIGHT WITH
LIGHT MOISTURE SOUTHWEST FLOW AT THE SURFACE. THE ONLY EXCEPTION
WILL BE SOME RECOVERY IN THE EAST WITH TEMPS IN THE LOWER TO MIDDLE
70S THIS MORNING. SO WITH THIS IN MIND HAVE OPTED TO LET THE CURRENT
EXCESSIVE HEAT WARNING AND ADVISORY TO EXPIRE AT 8 PM...BUT WILL LET
A HEAT ADVISORY BE IN EFFECT FOR THURSDAY IN THE WEST UNTIL 8 PM.
SO AS FAR AS TEMPS ARE CONCERN ADJUSTED LOWS SLIGHTLY FROM NAM
GUIDANCE WITH LOWS IN THE MID TO UPPER 70S FOR TONIGHT AND THURSDAY
NIGHT. SOME LOCATIONS WILL PROBABLY NOT GET BELOW 80 WITH SUCH HIGH
DEWPOINTS. FOR HIGHS WENT WITH THE CURRENT FORECAST FOR TODAY HIGHS
AND WENT WITH A BLEND OF MAV AND GMOS GUIDANCE FOR THURSDAY. HIGHS
WILL GENERALLY BY IN THE MID 90S TO AROUND 100./17/
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)...
BY THE END OF THE WEEK THE NORTHERLY FLOW ALOFT REGIME THAT`S BEEN
IN PLACE WILL WEAKEN AS UPPER RIDGING TO OUR WEST NOSES IN ACROSS
THE ARKLAMISS IN RESPONSE TO A S/WV TROF DEPARTING THE SE CONUS. THE
RISK OF MCS ACTIVITY DIVING IN FROM THE NORTH WILL LESSEN AS A
RESULT...SHIFTING FOCUS TO MORE OF A DIURNAL SHOWER/THUNDERSTORM
PATTERN TYPICAL FOR THIS TIME OF YEAR. THE OPPRESSIVE HEAT WE`VE
BEEN DEALING WITH LOOKS TO EASE A BIT AS WELL AND IT DOES NOT APPEAR
ANY HEAT HEADLINES WILL BE NECESSARY HEADED INTO THE WEEKEND...
ALTHOUGH AREAS ACROSS THE DELTA MAY FLIRT WITH CRITERIA ON FRIDAY.
RELATIVELY HIGHER RAIN CHANCES LOOK TO DEVELOP SUN/MON AS THE UPPER
RIDGE SHIFTS WEST AND A FRONTAL BOUNDARY ASSOCIATED WITH A CLIPPER
SYSTEM TRANSITING THE NORTHERN CONUS MOVES INTO THE TN VALLEY. IN
ADDITION...AN UPPER TROPOSPHERIC LOW OVER THE FAR SERN CONUS WILL
BEGIN TO SHIFT WEST WITH THE MODELS INDICATING A TRACK SOMEWHERE
ACROSS THE NORTHERN/CENTRAL GULF OF MEXICO. THE COMBINATION OF THESE
FEATURES WITH A WARM AND MOIST ATMOSPHERE IN PLACE SHOULD RESULT IN
DECENT SHOWER/THUNDERSTORM COVERAGE BOTH SUNDAY AND MONDAY
AFTERNOONS. TAME LAPSE RATES AND WEAK OVERALL FLOW SHOULD MITIGATE
THE RISK FOR SEVERE THUNDERSTORMS DURING THIS TIME BUT A FEW STRONG
STORMS IS CERTAINLY NOT OUT OF THE QUESTION. THE INCREASED CHANCE
FOR RAIN WILL HELP KEEP TEMPS A TAD COOLER DURING THIS TIME BUT
STILL EXPECTING READINGS TO COME IN ABOVE NORMAL AT MOST LOCALES.
HEADED INTO TUE/WED...THE GFS IS MUCH MORE AGGRESSIVE PUSHING DRIER
AIR IN WAKE OF THE FRONT INTO CENTRAL MS WHERE THE ECMWF HANGS THE
BOUNDARY UP ACROSS NORTHERN MS. DECIDED TO LEAN MORE ON THE ECMWF
SOLUTION WHICH MEANT A SLIGHT INCREASE IN OVERNIGHT LOWS FOR MON
NIGHT/TUE NIGHT. POPS WERE ADJUSTED A BIT...MOSTLY TO MAINTAIN AT
LEAST A SLIGHT CHANCE ACROSS ALL AREAS WITH BETTER RAIN CHANCES
FURTHER SOUTH. /BK/
&&
.AVIATION...FOCUS FOR THE AFTERNOON WILL BE ON THE ISO/SCT T-STORMS
THAT LOOK TO BE POSSIBLE. AT THIS POINT...WILL INCLUDE A VCTS FOR A
COUPLE SITES TO ACCOUNT FOR THIS. AT THIS TIME...N-CENTRAL AND
CENTRAL PORTIONS MAY HAVE THE BEST RISK FOR THAT. TIMING LOOKS TO BE
AFTER 20-21Z AND TIL 01-02Z. STORMS COULD CONTAIN GUSTY WINDS AND
WILL UTILIZE AMD TO SHOW THOSE IMPACTS IF/WHEN A STORM MAY THREATEN
A SITE. OUTSIDE THAT...THE NGT PERIOD LOOKS TO BE GENERALLY QUIET.
THERE MAY BE SOME SMALL PERIOD OF MVFR VIS AROUND SUNRISE THU
MORNING AND WILL COVER THAT WITH A SMALL PERIOD AT A COUPLE SITES.
/CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 98 79 96 77 / 20 22 23 21
MERIDIAN 98 77 96 77 / 20 22 23 23
VICKSBURG 97 79 97 78 / 22 20 23 22
HATTIESBURG 97 79 95 78 / 21 18 23 22
NATCHEZ 95 77 96 76 / 22 19 23 21
GREENVILLE 99 79 97 78 / 22 23 23 23
GREENWOOD 98 78 95 77 / 19 23 23 23
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR
MSZ026>033-036>039- 043>046-048>052-054>058-061>066-072>074.
EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR MSZ018-
019-025-034-035-040-041-047.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM CDT THURSDAY FOR
MSZ018-019-025-034-035-040-041-047.
HEAT ADVISORY UNTIL 8 PM CDT THURSDAY FOR MSZ042-053-059-060.
LA...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023-025.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM CDT THURSDAY FOR
LAZ007>009-015-016-023-025.
HEAT ADVISORY UNTIL 8 PM CDT THURSDAY FOR LAZ024-026.
AR...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR ARZ074-
075.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM CDT THURSDAY FOR
ARZ074-075.
$$
17/BK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
611 PM CDT THU AUG 2 2012
.AVIATION...00Z KGRI TAF. VFR CONDITIONS ARE ANTICIPATED.
SCATTERED SKY COVER FROM TIME TO TIME WITH LIGHT AND VARIABLE
WIND EVENTUALLY BECOMING SOUTH BY THURSDAY MORNING. CONVECTION TO
THE WEST AND SOUTHWEST WILL PROBABLY STAY CLEAR OF THE
TERMINAL...AND WITH ONLY A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST...THIS HAS NOT BEEN INCLUDED IN THIS
FORECAST.
&&
.PREV DISCUSSION... /ISSUED 333 PM CDT THU AUG 2 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY AFTERNOON. CONCERN IN THE NEXT
24 HRS WILL BE SLIGHT CHANCES FOR TSTMS EARLY ON ALONG WITH HIGH
TEMPERATURES FOR FRIDAY.
CURRENT WATER VAPOR IMAGERY ALONG WITH UPPER AIR AND WIND PROFILER
DATA SHOW UPPER RIDGE NOW ANCHORED OVER TEXAS...AN UPPER LOW
DROPPING SSE AND INTO THE WESTERN PART OF ALBERTA...PUTTING THE
PLAINS IN WESTERLY FLOW. ONE CAN ALSO SEE THE SUBTROPICAL MOISTURE
TAP STREAMING NORTH ACROSS WESTERN MEXICO...INTO THE FOUR CORNERS
REGION AND THEN SWINGING EAST AROUND THE HIGH ACROSS OUR REGION.
AT THE SURFACE...PRESSURE GRADIENT VERY WEAK ACROSS NEB/KS WITH ONE
WEAK SURFACE LOW OVER OKLAHOMA AND ANOTHER ONE SITUATED ACROSS
EASTERN MT/WY. SURFACE DEWPOINTS REMAIN FAIRLY HIGH OVER THE CWA
RANGING FROM THE MID TO UPPER 60S AT LUNCHTIME. WEAK CONVECTIVE
ACTIVITY HAS NEVER QUITE FADED AWAY IN OUR KS CWA ALTHOUGH DOUBT
ANYTHING IS REACHING THE GROUND. CLOUD COVER ACROSS OUR SOUTHERN CWA
HAS BEEN HOLDING IN A LITTLE LONGER THAN ANTICIPATED AND WITH SOME
RE-DEVELOPMENT TO THE WEST...MAY NOT SEE HIGHS QUITE AS WARM AS
EXPECT. ALSO WEAK CELLS MOVING ACROSS NORTHERN NEBRASKA HAVE ALSO
HUNG IN DURING THE DAY. SOME OF THE HOURLY HRRR MODEL RUNS HAVE
SHOWN THIS HANGING TOGETHER AND MOVING INTO THE WESTERN PART OF THE
CWA LATER THIS AFTERNOON. WILL NEED TO MONITOR THIS OVER THE NEXT
FEW HOURS.
BELIEVE OUR BETTER...ALTHOUGH NOT GREAT...CHANCES FOR RAIN WILL BE
LATER THIS EVENING AND OVERNIGHT. CHECKING OUT THE NEEDED
INGREDIENTS...WE HAVE ADEQUATE INSTABILITY...MOISTURE AND SHEAR AT
PRESENT BUT SEEM TO BE LACKING A FORCING MECHANISM. BELIEVE THE
SURFACE TROUGH ALONG THE FRONT RANGE MAY FIT THE BILL AND WILL
MONITOR CONVECTIVE DEVELOPMENT OUT WEST LATER THIS AFTERNOON.
QUESTION THEN BECOMES WILL THIS ACTIVITY MAKE IT FAR ENOUGH EAST TO
AFFECT OUR CWA. EARLY LOOK AT HRRR SHOWS THIS IS POSSIBLE AND WILL
CHECK OUT THE 4KM WRF WHEN IT ARRIVES. SEEMS LIKE BETTER LOW LEVEL
JET REMAINS WEST OVERNIGHT.
ON FRIDAY AFTERNOON...THE UPPER LOW NOTED ABOVE WILL SHOULD BE
CENTERED SOMEWHERE NEAR THE MT/NDAK/CANADA BORDER. THIS IS A DECENT
WAVE AND SHOULD PROVIDE GOOD HEIGHT FALLS AND COOLER TEMPS ALOFT TO
THE NORTHERN PLAINS. IT WILL ALSO PUSH A COLD FRONT INTO OUR NW CWA
BY LATE AFTN OR EARLY EVENING. EXPECT SOME COMPRESSIONAL HEATING
AHEAD OF THE FRONT AND WITH SURFACE WINDS BECOMING SOUTH TO SSW
ANOTHER HOT DAY WILL BE IN STORE. DO NOT PLAN ON ISSUING ANY HEAT
HEADLINES AS APPARENT TEMPERATURE VALUES FORECAST TO BE BETWEEN 98
AND 102 DEGREES IN THE SOUTHERN CWA. NOT SURE IF CONVECTION WILL
BREAK OUT LATE FRIDAY AFTERNOON OR HOLD OFF UNTIL THE EVENING AS
MOST MODELS SHOWING THE BULK OF THE PRECIPITATION BEING POST
FRONTAL. IF I DO PUT IN AFTERNOON POPS...IT WILL MAINLY BE IN THE
NORTHWEST AND WEST PART OF THE CWA.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
CONCERNS FOR THE MID AND LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR THUNDERSTORMS AS WELL AS COOLER TEMPERATURES FOR THE
WEEKEND.
BEGINNING THE MID TERM PERIOD...THE MODELS REMAIN IN FAIRLY
CONSISTENT AGREEMENT AS THE UPPER LEVEL LOW CONTINUES TO SHIFT
EASTWARD ACROSS PORTIONS OF MONTANA AND NORTH DAKOTA. AT THE
SURFACE...A LARGE AREA OF LOW PRESSURE ALSO CONTINUES TO PUSH
EASTWARD...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY KNOCKING ON OUR
DOORSTEP BY FRIDAY EVENING. THUNDERSTORM CHANCES CONTINUE INTO THE
OVERNIGHT HOURS...WITH THE POSSIBILITY OF A FEW STRONG STORMS IN THE
EARLY EVENING. BY LATE SATURDAY MORNING...THE FRONTAL BOUNDARY
SHOULD BEGIN TO SAG SOUTHEAST OUT OF THE REGION WITH LINGERING
SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG THE ELEVATED
BOUNDARY. WITH FRONTAL PASSAGE OVERNIGHT FRIDAY...HIGH PRESSURE AND
COOLER TEMPERATURES WILL SINK INTO THE REGION ALONG WITH NORTH
WINDS. MUCH COOLER 850 TEMPERATURES ON THE ORDER OF 10 DEGREES
COOLER THAN PREVIOUS DAYS WILL HELP DRASTICALLY REDUCE HIGH
TEMPERATURES. A VERY NICE WEEKEND IS IN STORE WITH HIGHS IN THE MID
TO UPPER 80S.
BY THE BEGINNING OF THE WORKWEEK...THE UPPER LEVEL RIDGE WILL BEGIN
TO BUILD BACK IN ACROSS THE ROCKIES...RESULTING IN NORTHWEST FLOW
THROUGH THE EXTENDED PERIOD. A DRY FORECAST IS EXPECTED THROUGH THE
BEGINNING OF THE WORKWEEK AS THE CENTRAL PLAINS REMAIN UNDER SURFACE
HIGH PRESSURE.
HOWEVER...TOWARDS THE END OF THE PERIOD...A FEW SHORT WAVE
PERTURBATIONS ROUND THE EASTERN EDGE OF THE UPPER LEVEL RIDGE...AND
COMBINED WITH A SURFACE TROUGH AXIS ALONG THE FRONT RANGE WILL HELP
GENERATE SOME CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
EXTENDED. CONTINUED SLIGHT CHANCES THROUGH THE PERIOD...MONDAY AND
AGAIN TUESDAY NIGHT THROUGH WEDNESDAY.
AS FOR TEMPERATURES...ALTHOUGH MUCH OF THE WARMER 850 TEMPERATURES
REMAIN FARTHER WEST ACROSS THE ROCKIES...EXPECT A RISE IN
TEMPERATURES THROUGH THE WORKWEEK. CONTINUED WITH HIGHS IN THE MID
TO UPPER 90S.
PREV DISCUSSION... /ISSUED 1213 PM CDT THU AUG 2 2012/
AVIATION...EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST
PERIOD. THERE IS JUST A SLIGHT CHANCE FOR THUNDERSTORMS LATER THIS
AFTERNOON AND INTO THE OVERNIGHT HOURS BUT LOOKS TO BE 20 PERCENT
SO WILL LEAVE OUT OF TAF. OTHERWISE WINDS WILL REMAIN LIGHT FOR
MOST OF THE PERIOD ALTHOUGH THEY SHOULD BEGIN TO PICK UP OUT OF
THE SOUTH A BIT BY MID MORNING FRIDAY AS THE PRESSURE GRADIENT
TIGHTENS UP WITH APPROACHING COLD FRONT MOVING IN FROM THE
NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...HEINLEIN
SHORT TERM...EWALD
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
501 PM CDT WED AUG 1 2012
.DISCUSSION...
IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS
THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD
FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER
WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE
DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY
SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN
PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO
STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF
DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT
UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY
DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS...
WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE
MIDNIGHT.
CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE
WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE
TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS
UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT
WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH
DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES
AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT.
POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN
CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY
AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER
BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE
MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS.
DEE/BCM
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED TO DOMINATE THE TAF CYCLE. HAVE OPTED
TO REMOVE MENTION OF TSRA AT ALL SITES TONIGHT RATHER THAN
CONVERT THE PROB30 TO TEMPO OR PREVAILING...AS AM NOT CONFIDENT
ABOUT COVERAGE ONCE STORMS DROP OUT OF SD INTO AN AIRMASS THAT IS
VERY DRY BELOW 9-10KFT. THINK STORMS MAY BE SCT TO ISO IN
COVERAGE BY THE TIME THEY REACH KOFK...AND DISSIPATE BEFORE
REACHING KOMA...WITH ANY SCT TO ISO STORMS AT KOFK MOST LIKELY TO
OCCUR AROUND 07-09Z. WILL NEED TO MONITOR POTENTIAL AROUND KLNK
AROUND 08-10Z FOR TSRA POTENTIAL AS THE AIRMASS THERE IS LESS DRY
AND CIGS MAY BE A LITTLE LOWER...WITH PERHAPS MORE OF A CHANCE
THERE THAN THE OTHER SITES. WILL TEMPER TSRA/SHRA MENTION...WITH
LATER SHIFTS ABLE TO ADD TSRA SHOULD A THREAT MATERIALIZE.
OTHERWISE...VFR CONDITIONS ARE EXPECTED...WITH CLOUDS AT OR ABOVE
15KFT OUTSIDE OF ANY SHRA/TSRA. WINDS WILL SHIFT FROM SOUTHERLY TO
MAINLY EASTERLY BEHIND THE WEAK BOUNDARY THAT PASSES THROUGH LATE
TONIGHT.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
$$
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
331 PM PDT WED AUG 1 2012
SYNOPSIS...A DISTURBANCE IN THE ATMOSPHERE COMBINED WITH ABUNDANT
MOISTURE AND INSTABILITY WILL RESULT IN SHOWERS AND THUNDERSTORMS
AROUND AT TIMES THROUGH THIS WEEKEND. ALTHOUGH HEAVY RAIN WILL BE
THE PRIMARY THREAT WITH HEAVIER STORMS...GUSTY WINDS AND HAIL MAY
ALSO OCCUR. BY EARLY NEXT WEEK DRIER AIR LOOKS TO SLOWLY SPREAD EAST
ACROSS THE AREA WHICH SHOULD DECREASE THE CHANCES FOR THUNDERSTORMS
AND ALSO RESULT IN A WARMING TREND.
&&
.SHORT TERM...SO FAR THINGS HAVE NOT BEEN AS ACTIVE THIS AFTERNOON
AS THEY WERE AT THIS POINT YESTERDAY DESPITE AN EXTREMELY MOIST
ATMOSPHERE...PLENTY OF INSTABILITY AND MUCH MORE SUNSHINE. WATER
VAPOR IMAGERY SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW WAS OVER
SOUTHERN CLARK COUNTY AND MOVING SLOWLY NORTHEASTWARD. RADAR SHOWS
AT THE PRESENT MOST OF THE ACTIVITY WAS ABOUT 100 MILES AWAY FROM
THE CENTER OF THE LOW. THE ATMOSPHERE REMAINS EXCEPTIONALLY MOIST
WITH THE 12Z SOUNDING THIS MORNING FROM OUR OFFICE HAVING A PWAT OF
1.82 INCHES. THIS TIED FOR THE SECOND HIGHEST PWAT EVER RECORDED IN
THE SOUNDING CLIMATOLOGY FOR SOUTHERN NEVADA WITH A VALUE BACK IN
AUGUST OF 1984 (THE HIGHEST EVER WAS 1.86 INCHES IN JULY 1966). WITH
SO MUCH MOISTURE PRESENT ANY SHOWER OR THUNDERSTORM THAT GETS GOING
WILL HAVE THE POTENTIAL TO PRODUCE EXTREMELY HEAVY RAIN IN A SHORT
PERIOD OF TIME. THUS THE FLASH FLOOD WATCH OUT WILL REMAIN IN EFFECT.
THE MAIN CHALLENGE FOR THIS EVENING AND THE REST OF TONIGHT WILL BE
JUST HOW ACTIVE THINGS WILL GET. WITH THE MID/UPPER LEVEL LOW
PROGGED TO BE AROUND THROUGH TONIGHT IT WILL BE HARD TO COMPLETELY
SHUT DOWN ALL CONVECTION EXCEPT IN ANY AREAS WHERE THE AIR MASS GETS
WORKED OVER ENOUGH THAT IT BECOMES MUCH MORE STABLE. IF YOU BELIEVE
THE WRF...GFS AND ECMWF CONVECTION SHOULD WIND DOWN AROUND 03Z OR SO
THIS EVENING. ON THE OTHER HAND...THE LOCAL ARW AND NMM MODELS AS
WELL AS THE HRRR MODEL SHOW THE REVERSE WITH THINGS BECOMING MUCH
MORE ACTIVE LATER THIS EVENING. 700 MB STEERING FLOW IS FROM THE
NORTHEAST AND RADAR PRESENTLY SHOWS SHOWERS AND THUNDERSTORMS IN AN
ARCH FROM AROUND ELY TO KANAB. TYPICALLY THIS PATTERN WOULD FAVOR
THIS CONVECTION EVENTUALLY WORKING IN DURING THE LATE EVENING INTO
CLARK COUNTY. IN THE PAST STORMS IN LAS VEGAS ORIGINATING FROM A
NORTHEAST FLOW HAVE USUALLY BEEN RATHER POTENT. THUS...BASED ON A
BLEND OF MODELS WE HAVE KEPT POPS IN THROUGH THE NIGHT FOR MUCH OF
LINCOLN...CLARK...MOHAVE....EASTERN SAN BERNARDINO AND SOUTHERN NYE
COUNTIES. ALTHOUGH FLASH FLOODING REMAINS A THREAT...WE CANNOT RULE
OUT GUSTY WINDS OR HAIL WITH SOME STORMS ESPECIALLY IF THINGS DRY
OUT A LITTLE.
VERY LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR THURSDAY
AND FRIDAY. THE MID/UPPER LEVEL LOW IS FORECAST TO GET TRAPPED NEAR
THE TRIPLE POINT OF CALIFORNIA...NEVADA AND ARIZONA AND EVENTUALLY
WEAKEN TO A MORE ILL-DEFINED VORTICITY FEATURE. MEANWHILE HIGH
PRESSURE IN THE MID AND UPPER LEVELS IS FORECAST TO BECOME CENTERED
OVER CENTRAL NEVADA. THIS HIGH WILL KEEP AN EASTERLY MID-LEVEL FLOW
OVER OUR AREA WHICH BY FRIDAY WILL HELP TO PUSH THE VORTICITY
FEATURE TO THE SOUTHWEST AND BY FRIDAY NIGHT PUSH IT OFFSHORE OF
SOCAL. OVER THE NEXT 2 DAYS THE FARTHER NORTHWEST ONE GOES IN THE
CWFA THE LESS OF CHANCE FOR CONVECTION AS THE HIGH ALOFT WILL KEEP
THE ATMOSPHERE MUCH MORE STABLE. FURTHER SOUTH THE COMBINATION OF
THE VORTICITY FEATURE...INSTABILITY AND SUFFICIENT MOISTURE WILL
KEEP THE POTENTIAL FOR THUNDERSTORMS AROUND. WHILE PWATS ARE
FORECAST TO REMAIN OVER AN INCH OVER THE MOJAVE DESERT WHICH WILL
SUPPORT HEAVY RAIN PRODUCING STORMS...WE WILL NOT ISSUE ANY FLASH
FLOOD WATCHES FOR THURSDAY OR FRIDAY AT THIS TIME DUE TO
UNCERTAINTIES IN JUST HOW ACTIVE IT WILL GET. TEMPS SHOULD BE A FEW
DEGREES ABOVE NORMAL BUT MUCH WARMER THAN WHAT WE HAVE SEEN THE PAST
FEW DAYS OVER THE MOJAVE DESERT. WELL ABOVE NORMAL TEMPS WILL
CONTINUE OVER INYO AND ESMERALDA COUNTY.
.LONG TERM...THE OLD VORTICITY FEATURE OFF OF SOCAL GETS CAUGHT UP
IN A BROAD MID/UPPER LEVEL TROUGH OFF THE WEST COAST ON SATURDAY. IT
APPEARS ENOUGH MOISTURE AND INSTABILITY REMAIN AROUND ON SATURDAY
THAT THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE ESPECIALLY ACROSS
THE NORTHERN HALF OF THE CWFA WHERE THE BEST INSTABILITY LOOKS TO
SET UP. BY SATURDAY NIGHT INTO SUNDAY DRIER AND MORE STABLE AIR IS
SHOWN TO WORK IN FROM THE SOUTH AS THE OFFSHORE TROUGH EDGES CLOSER
TO THE COAST AND MOST OF THE EMBEDDED ENERGY WITHIN THE TROUGH
STARTS TO LIFT ON NORTH. THUS SUNDAY MAY NOT BE QUITE AS ACTIVE FOR
CONVECTION AND POPS SHOW A SLIGHT TREND DOWN THEN. BY MONDAY INTO
NEXT WEDNESDAY THE TROUGH OFFSHORE STILL EXISTS AND RIDGING ALOFT
SITS OVER THE FOUR CORNERS. THIS WOULD FAVOR A SOUTHWEST FLOW ALOFT
ACROSS OUR AREA WHICH WOULD SPREAD DRIER AND STABLE AIR FURTHER EAST
WITH TIME. I DID LOWER POPS AND DEWPOINTS IN THE WESTERN HALF OF THE
AREA TO ACCOUNT FOR THIS HOWEVER MOIST AND UNSTABLE AIR IS SHOWN TO
LINGER OVER MOHAVE COUNTY AND THIS PART OF THE AREA MAY NEVER REALLY
DRY OUT. TEMPS SHOULD RISE BACK CLOSER TO NORMAL IN MOST AREAS AND
MAY EVEN BE A FEW DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY AS
THINGS REALLY DRY OUT. I LEANED CLOSELY TO THE ECMWF MOS AND BIAS
CORRECTED NUMBERS FOR HIGHS.
&&
.AVIATION...FOR MCCARRAN...LOW CONFIDENCE IN THE TIMING OF ANY
SHRA/TSRA THIS EVENING. THERE IS SOME POSSIBILITY ACTIVITY IN THE
FORM OF AN OUTFLOW BOUNDARY OR SHRA/TSRA ARRIVING FROM THE NORTHEAST
BETWEEN 03Z AND 09Z THIS EVENING. WILL JUST LEAVE IN VCTY ACTIVITY
AND ADJUST THE TAF AS NEEDED. FOR THURSDAY SHRA/TSRA ARE MOST LIKELY
AFTER 19Z. SIMILAR TIMING FOR SHRA/TSRA IN THE APPROACH CORRIDORS.
OTHERWISE WINDS SHOULD FAVOR DIURNAL TRENDS WITH BKN CLOUDS AOA
10K-14K FEET. REDUCED CIGS/VSBY AND GUSTY AND ERRATIC WINDS IN AND
NEAR HEAVIER SHRA/TSRA.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT SHRA/TSRA THROUGH THIS EVENING WITH ACTIVITY
GENERALLY TRENDING DOWN AFTER 06Z. COVERAGE OF SCT SHRA/TSRA SHOULD
INCREASE AFTER 19Z ON THURSDAY. THE BEST CHANCES FOR SHRA/TSRA WILL
CONTINUE TO BE IN MOHAVE...LINCOLN...CLARK AND THE SAN BERNARDINO
COUNTY DESERTS. GUSTY AND ERRATIC WINDS AND REDUCED CIGS/VSBY NEAR
ANY SHRA/TSRA. OTHERWISE WINDS FAVORING DIURNAL TRENDS WITH BKN CIGS
AOA 10K-14K FEET. DRY AT KBIH WITH A FEW CLOUDS AOA 14K FEET IN THE
AFTERNOON AND EVENING.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR NVZ016>022.
AZ...FLASH FLOOD WATCH UNTIL 11 PM MST THIS EVENING FOR AZZ001>003-
036.
CA...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR CAZ524>527.
&&
$$
STACHELSKI
HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1124 AM EDT WED AUG 1 2012
.SYNOPSIS...
A WEAK COOL FRONT AND AN AREA OF UPPER LEVEL LOW PRESSURE WILL
KEEP A CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST
THROUGH THIS EVENING. HIGH PRESSURE BUILDS IN WITH MAINLY DRY AND
SOMEWHAT WARMER CONDITIONS FOR THURSDAY. ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS IS EXPECTED ON FRIDAY AFTERNOON AS A
WARM FRONT TAKES SHAPE ACROSS NORTH CENTRAL NEW YORK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL WAVE ACROSS THE EASTERN
LAKES THIS MORNING. THE WAVE WAS COINCIDENT WITH MUCH DRIER AIR
ALOFT AND WAS SLOWLY MOVING EAST INTO CENTRAL NY AND NORTHEAST PA.
THE WAVE ALOFT WAS ALSO COINCIDENT WITH A WEAK SFC BOUNDARY. THIS
BOUNDARY WILL WORK EAST THIS AFTERNOON. AT PRESENT THERE WAS A
LOT OF LOW CLOUDS AND STRATUS ACROSS MUCH OF THE REGION. AS THIS
DRIER AIR ALOFT WORKS E IT WILL BREAK UP THE LOWER ST LAYER IN
CONCERT WITH THE DIURNAL HEATING OF THE BNDRY LAYER. ONE CAN SEE
THIS HAPPENING ON THE VISIBLE SATL IMAGERY IN NY AND PA. RADAR WAS
SHOWG SOME ISLD CELLS DEVELOPING OVER THE ROC AREA ALONG THE FRNT.
AS THIS DRY AIR WORKS E AND GETS OUT AHEAD OF THE FRNT...THERE
WILL BE SIGNIFICANT MIXING IN THE BNDRY LAYER AND DESTABILIZATION
THIS AFTERNOON IN ADVANCE OF THE FRNT. MODEL SOUNDINGS FROM THE
NAM AND RUC ARE MOST UNSTABL THIS AFTERNOON WITH PROJECTED MIXED
LAYER CAPES AOA 1000 J/KG. THE GFS...LOCAL WRF AND SREF HAVE LESS
INSTABILITY PROJECTING GENERALLY AROUND 500 J/KG. ALL MODELS HAVE
WEAK WIND FIELDS ALOFT WITH 0-6 KM, 0-3 AND 0-1 KM BULK SHEARS
LESS THAN 10 KNOTS. HOWEVER...THERE WAS A LOT OF DRY AIR ALOFT
ADVECTING EAST AS CONFIRMED ON THE WATER VAPOR IMAGERY AND THE 12Z
BUF AND ESPECIALLY THE 12Z DTX SOUNDING IN SERN LWR MI. IF THE
WEAK FRONT AND WAVE ALOFT CAN ORGANIZE SOME CAPE INTO A LINE OR CLUSTER
OF CELLS...THERE CUD BE AN ISOLATED DOWNBURST OR TWO. BUT...THE
FRONT IS RATHER WEAK AND DIFFUSE AND THE FORCING ALOFT IS NOT
IMPRESSIVE EITHER...SO THIS DRY AIR LIKELY WILL GO AGAINST DEEP
CONVECTION IN THESE AREAS. SO POPS WILL BE LOWER IN THE WESTERN
PART OF THE BGM FORECAST AREA INCLUDING THE FINGER LAKES WHERE THE
DRIER AIR MAKES IT E DURING MAX HEATING.
CONVECTION WILL BE MORE WIDESPREAD IN THE EASTERN PART OF THE BGM
SERVICE AREA WHERE CONVECTION WILL HAVE DEEPER MOISTURE TO TAP
INTO AS THE DRY AIR ALOFT IS NOT PROJECTED TO REACH THESE AREAS
UNTIL 22Z OR LATER...HENCE MOST OF THE CAPE WILL BE REALIZED
BEFORE THIS DRYING ALOFT OCCURS. HENCE PWATS WERE HIGHER AND GIVEN
THE LIGHT WINDS ALOFT...I CUD SEE SOME SLOW MOVING STORMS WITH
LOCALLY HEAVY RAINFALL. I THINK COVERAGE WILL BE HIGHER IN THE
EAST ALSO BECAUSE THERE WILL BE LESS ENTRAINMENT OF DRIER AIR
ALOFT AND SUFFICIENT INSTABILITY. POPS FROM PREVIOUS SHIFT LOOK
FINE.
CONVECTION ALLOWING MESOSCALE MODELS ALL SHOW MORE CONVECTION IN
THE EASTERN PART OF THE BGM CWA THAN IN THE WEST WHICH GO ALONG
WITH THE ABOVE THINKING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ANY CONVECTION THIS EVENING SHOULD WANE OVERNIGHT WITH LOSS OF
HEATING AND GENERAL RIDGING DEVELOPING THROUGH 850 MB. THIS TREND
WILL CONTINUE THROUGH THURSDAY WITHIN A ZONAL FLOW ALOFT AND A
FRONT REMAINING TO OUR WEST. MODELS THEN SUGGEST ANOTHER FRONTAL
SYSTEM MAKING IT`S WAY TOWARD THE REGION ON FRIDAY BUT REMAINING
JUST TO OUR NORTH. INCREASING HEAT AND MOISTURE SOURCES WILL
DECREASE STABILITY WITH ENOUGH WEAK FORCING FROM UPPER WAVES
PASSING THROUGH THE FLOW THAT SCATTERED THUNDERSTORMS SHOULD FORM
FRIDAY AFTERNOON INTO THE EVENING.
TEMPERATURES WARMING UP FOR THURSDAY AND FRIDAY WELL INTO THE 80S
TO NEAR 90 AS WARM SECTOR BECOMES ESTABLISHED AND 850 MB TEMPS
RISE TO 18-20C.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED PERIOD BEGINS WITH A ZONAL FLOW ACROSS THE NERN
CONUS, WHILE A JET DIGS INTO THE NORTHERN PLAINS. THIS JET WILL
CARVE OUT A TROF, WHICH WILL SLIDE EASTWARD TOWARD THE GREAT LAKES
EARLY SUNDAY. THE RESULT WILL BE AN UNSETTLED PERIOD, WITH A COLD
FRONT PROGGED TO PUSH INTO NY/PA SUNDAY NIGHT OR
MONDAY...ACCOMPANIED BY THUNDERSTORMS.
DAYTIME MAXES WILL CHALLENGE THE MID TO UPPER 80S ACROSS MUCH OF
THE FA ON SATURDAY...WITH THE LAKE PLAIN APPROACHING 90. AFTER THE
COLD FRONT PASSES...TEMPS WILL RETURN TO NORMAL LEVELS FOR MID WEEK.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS FORECAST, ELM FELL DEEP INTO LIFR TERRITORY THIS MORNING IN
DENSE FOG. THIS WAS THE RESULT OF WET ANTECEDENT CONDITIONS, LIGHT
WIND FLOW AT THE SFC AND ALOFT, AND LOW TDD VALUES. LIGHT FOG
AFFECTED BGM BRIEFLY...OTHERWISE NO RESTRICTIONS ARE BEING
OBSERVED OUTSIDE OF ELM.
MIXING THIS MORNING SHOULD ALLOW ELM TO RECOVER TOWARD VFR
TERRIORY BETWEEN 13Z AND 14Z.
THE REMAINDER OF THE DAY SHOULD BE VFR, BUT THERE IS A CHANCE FOR
SOME ISOLATED THUNDERSTORM ACTIVITY IN THE AFTERNOON. ANY STORM
WHICH DEVELOPS COULD PRODUCE BRIEF MVFR RESTRICTIONS IN DOWNPOURS.
OUTLOOK...
THU THROUGH SUN...MVFR RESTRICTIONS PSBL...IN DIURNALLY DRIVEN
SHRA/TSRA ACTIVITY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/JAB
NEAR TERM...DJN
SHORT TERM...JAB
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
725 AM EDT WED AUG 1 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE SOUTHEAST INTO THE
CAROLINAS THROUGH THURSDAY. UPPER LEVEL HIGH PRESSURE WILL THEN
BUILD INTO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...
THIS MORNING...
COMPLICATED UPPER LEVEL FLOW CONTINUES OVER THE REGION WITH
NUMEROUS DISTURBANCES ROTATING THROUGH THE BASE OF THE UPPER LEVEL
TROUGH...WHICH CURRENTLY EXTENDS ALL THE WAY SOUTH INTO SOUTHERN
GA. THE MOST NOTABLE VORTICES WERE LOCATED OVER EASTERN
NC...UPSTATE SC...AND WESTERN VA. RECENT RADAR TRENDS SUGGEST THE
BROKEN LINE OF CONVECTION OVER VA WILL CONTINUE TO MOVE SLOWLY
EASTWARD AND THE OUTFLOW MAY BE THE FOCUS FOR SHOWERS OVER THE
NORTHERN COASTAL PLAIN DURING THE NEXT COUPLE OF HOURS. TO THE
SOUTH... SCATTERED SHOWERS AND A COUPLE THUNDERSTORMS ARE
EXPANDING NORTHWARD OUT OF SC INTO THE SOUTHERN PIEDMONT AND
SANDHILLS. A WEAK LOW PRESSURE CENTER IS FORECAST TO DEVELOP NEAR
THE SAVANNAH RIVER BASIN IN RESPONSE TO THE DPVA APPROACHING A
STALLED OUT...WEAK FRONTAL ZONE OVER THE SC/NC COASTAL REGIONS.
HOWEVER... IT IS HARD TO DETECT AN ACTUAL LOW SO FAR. 00Z RAOBS
FROM KMHX AND KCHS SHOW A FAIR AMOUNT OF ELEVATED INSTABILITY FOR
THE ONGOING SHOWERS TO FEED ON...AND THE HRRR SEEMS TO BE HANDLING
THE TIMING OF THE PRECIP WELL..ALTHOUGH THE RADAR ECHOES EXTEND
FURTHER WEST THAN THE SIMULATIONS. OVER THE NEXT 3-6
HOURS...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED STORMS...ALONG
WITH MORE DEVELOPMENT BACK TO THE SOUTHWEST...SHOULD CONTINUE TO
MOVE TO THE NORTHEAST TO THE EAST OF US HWY 1...WITH MORE ISOLATED
SHOWERS POSSIBLE FURTHER WEST.
WHILE AN AXIS OF AROUND 1000 J/KG OF MUCAPE WILL EXIST THIS
MORNING...THE THREAT IF ANY SEVERE WEATHER IS LOW THROUGH MIDDAY
GIVEN THE WEAK DEEP LAYER FLOW IN THE TROUGH. IF/WHEN THE SURFACE
LOW DEVELOPS AND MOVES NORTHEAST ALONG THE COAST...THE MAY BE A
SHORT WINDOW WHERE LOW LEVEL SHEAR IS ENHANCED...BUT THE 0-1KM AND
0-3KM FLOW JUST LOOKS TOO WEAK FOR THE SMALL TORNADIC CONCERNS THAT
MODELS HAD SHOWN IN PREVIOUS RUNS.
THIS AFTERNOON...
AS THE AXIS OF DEEPER MOISTURE MOVES OFFSHORE...CONVECTION SHOULD
COME TO AN END OVER THE COASTAL PLAIN. ANOTHER UPPER DISTURBANCE
CURRENTLY OVER THE UPPER MIDWEST WILL DIVE INTO THE BACK SIDE OF
THE TROUGH THIS EVENING AND MAY KICK OFF SOME STORMS OVER THE
MOUNTAINS. HOWEVER...MUCH DRIER AIR ALOFT APPROACHING FROM THE
WEST...NOTED ON WATER VAPOR IMAGERY...SHOULD KEEP ANY STORMS
ISOLATED TO WIDELY SCATTERED OVER THE WESTERN PIEDMONT AND MAINLY
AFTER 20Z.
FULL HEATING WOULD SUPPORT HIGHS AROUND 90 TO THE WEST OF US HWY 1
THIS AFTERNOON. TO THE EAST...CLOUD COVER AND SHOWERS ARE GOING TO
LIMIT HEATING THIS MORNING...THOUGH THE EXPECTED DRYING ALOFT AND
THINNING OF CLOUDS FROM THE WEST SHOULD ALLOW MOST AREAS TO REACH
THE MID 80S.
TONIGHT...
OUTSIDE OF THE POTENTIAL FOR A FEW SHOWERS/STORMS MOVING
OFF THE HIGHER TERRAIN TO MAKE IT INTO THE PIEDMONT...CONDITIONS
SHOULD BE RELATIVELY QUIET WITH LOWS IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...
THURSDAY AND THURSDAY NIGHT...
A WEAK UPPER LEVEL LOW/SHEAR AXIS IS FORECAST TO BREAK OFF FROM
THE UPPER TROUGH AND SLIP SOUTH TOWARD THE SC COAST ON THURSDAY.
THE FOCUS FOR CONVECTION WILL MAINLY BE ALONG THE COAST...WITH
WEAK ANTICYCLONIC FLOW AND DRIER AIR ALOFT OVER MUCH OF CENTRAL
NC. MAINLY A SLIGHT CHANCE OF SHOWERS/STORMS SOUTH AND EAST OF THE
TRIANGLE DURING THE AFTERNOON. LOW LEVEL THICKNESSES GENERALLY
SUPPORT LOWER 90S AREA WIDE. WITH LITTLE CLOUD COVER
OVERNIGHT...TEMPS SHOULD FALL QUICKLY TO THE UPPER 60S TO LOWER
70S...AND STRATUS/FOG MAY BE AN ISSUE.
FRIDAY AND FRIDAY NIGHT...
THE NAM AND THE GFS ARE FAIRLY CONSISTENT IN FORECASTING A WEAK
UPPER LOW OR SHEAR AXIS TOWARD THE COASTAL PLAIN AND THE CAROLINA
COAST. UNDER A BROAD SOUTHERLY FLOW FROM THE SURFACE THROUGH
850MB...MEAN MOISTURE GRADUALLY INCREASES...AND PRECIPITABLE WATER
VALUES THAT ARE AROUND 1.5 INCHES FRIDAY MORNING ARE FORECAST TO
INCREASE TO AROUND 1.75 INCHES BY 00Z SATURDAY. 250MB WINDS
DIMINISH AND WINDS FROM 850MB THROUGH 500MB ARE LIGHT... ONLY
AROUND 10KT AT BEST...MAKING FOR 0-6KM SHEAR VALUES ALSO AROUND
10KT AT BEST. WEAK LIFT IS FORECAST...BUT MUCH OF CENTRAL NORTH
CAROLINA MAY LIE JUST ON THE WEST SIDE OF THE UPPER LOW OR SHEAR
AXIS...AND NAM AND GFS BUFR SOUNDINGS SHOW A COUPLE OF DEGREES OF
MID- AND UPPER-LEVEL WARMING DURING THE DAY FRIDAY. WITH SLIGHT
MOISTURE ADVECTION...AND SOME UNCERTAINTY IN THE OVERALL LOCATION
OF THE WEAK UPPER-LEVEL FEATURES...THERE SHOULD BE ENOUGH
INSTABILITY... AROUND 1000J/KG OF MLCAPE...THAT A SEA BREEZE IN
THE SOUTHERLY FLOW...FOR EXAMPLE...COULD PROVIDE AN ISOLATED
SHOWER OR THUNDERSTORM. SLIGHT CHANCES WERE IN THE FORECAST AND
WILL NOT REMOVE THOSE...BUT CURRENTLY THINK THAT ISOLATED TO
WIDELY SCATTERED COVERAGE AT BEST WOULD OCCUR FRIDAY AFTERNOON
INTO FRIDAY EVENING.
BOTH THE NAM AND THE GFS PROVIDE FOR LIGHT QPF TOWARD AND WEST OF
THE YADKIN RIVER FRIDAY NIGHT...THOUGH BUFR SOUNDINGS WOULD TEND TO
SUPPORT MORE STABILITY AND THE TYPICAL DIURNAL MIN IN TERMS OF
CHANCES OF RAINFALL. THE GFS...AND TO SOME DEGREE THE NAM...FORECAST
A MODERATELY-STRONG MID-LEVEL SHORTWAVE MOVING INTO THE APPALACHIANS
LATE FRIDAY NIGHT...WHICH MAY BE A RESULT OF CONVECTIVE FEEDBACK.
THE SOUTHERLY 850MB FLOW IS FORECAST BY THE GFS TO STRENGTHEN NEAR
THE MOUNTAINS LATE FRIDAY NIGHT...SO AS THE AIR MASS MOISTENS IT IS
POSSIBLE FOR OVERNIGHT DEVELOPMENT OF SOME DEEP CONVECTION THERE...
THOUGH THE THERMAL WIND WOULD SEEM TO INDICATE A GENERAL MOTION
KEEPING MOST ACTIVITY WEST OF CENTRAL NORTH CAROLINA. WILL NOT
INTRODUCE ANY SLIGHT CHANCES FOR A SHOWER OR THUNDERSTORM OVERNIGHT
FRIDAY...THOUGH TRENDS WILL NEED TO BE WATCHED PARTICULARLY WITH
REGARD TO THE LOCATION AND STRENGTH OF ANY MID-LEVEL WAVE.
1000-850MB THICKNESSES SUPPORT THE SLIGHTLY COOLER MAV GUIDANCE FOR
HIGHS FRIDAY...MAINLY 90 TO 95. LOWS FRIDAY NIGHT AROUND 70.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...
THERE SEEM TO BE SOME CHANGES IN THE UPPER-AIR PATTERN AS
FORECAST BY THE GFS AND ECMWF...MOST NOTABLY HIGHER HEIGHTS ALOFT
OFFSHORE OF THE MID-ATLANTIC EARLY IN THIS PART OF THE LONG-TERM
PERIOD. AT THE SAME TIME...THE LOW-LEVEL FLOW AROUND BROAD BERMUDA
HIGH PRESSURE IS MORE SOUTHERLY ESPECIALLY EARLY IN THIS PART OF
THE LONG-TERM PERIOD...SUCH THAT THE MEAN AIR MASS IS GENERALLY
MORE MOIST THAN APPARENTLY WAS THE CASE AS FORECAST BY PREVIOUS
GUIDANCE. CERTAINLY THE TREND INTO EARLY NEXT WEEK
CONTINUES...WITH LOWERING HEIGHTS ALOFT AFTER THE WEEKEND AS AN
UPPER TROUGH MOVES EAST ACROSS THE GREAT LAKES AND SOUTHEAST
CANADA...EXTENDING INTO THE MID-ATLANTIC. BOTH THE GFS AND ECMWF
FORECAST A TROUGH AXIS ALOFT MOVING INTO CENTRAL NORTH CAROLINA
WITH A SHEAR AXIS LINGERING INTO TUESDAY. THE DGEX IS ALSO SIMILAR
IN REGARD TO THIS.
ANOTHER CONTINUING TREND OF THE CONSENSUS OF THE GFS AND ECMWF IS
THE GRADUAL INCREASE IN PRECIPITABLE WATER VALUES FROM SATURDAY
THROUGH MONDAY INTO TUESDAY. VALUES AROUND 1.75 INCHES OR SO
SATURDAY CLIMB TO AT OR JUST ABOVE TWO INCHES BY MONDAY AND
CONTINUE FOR THE MOST PART INTO TUESDAY...WITH POSSIBLY SOME
DRYING OVER THE NORTHWEST PIEDMONT LATE ON TUESDAY BASED ON THE
COARSE MODEL SOUNDINGS FROM THE GFS AND ECMWF. FOR THIS FORECAST...
MADE LITTLE CHANGES TO THE PREVIOUS FORECAST IN TERMS OF CHANCES FOR
PRECIPITATION...LOWER CHANCE PROBABILITIES FOR SATURDAY...GRADUALLY
INCREASING TO AROUND 40 PERCENT MONDAY WITH CHANCES CONTINUING
OVERNIGHT MONDAY NIGHT THROUGH TUESDAY NIGHT IN BETTER SYNOPTIC
FORCING ALOFT AS HEIGHTS FALL WITH THE ATTENDANT SHORTWAVE OR SHEAR
AXIS. THE HIGHEST CHANCES WILL BE FORECAST MONDAY...WHEN THERE
SHOULD BE THE BEST MID-LEVEL VORTICITY ADVECTION AND WHERE THE
GUIDANCE FORECASTS THE BEST LIFT. THE GFS HAS TRENDED SLIGHTLY
FASTER WITH THE TROUGH AXIS TUESDAY INTO TUESDAY NIGHT...AND FOR
THEN WILL NOTE HIGHER CHANCES...RELATIVE TO THE REST OF CENTRAL
NORTH CAROLINA...SOUTH AND EAST OF THE TRIAD. 1000-850MB THICKNESSES
HAVE TRENDED LOWER FROM RECENT DAYS IN THIS PART OF THE FORECAST...
AND WILL FORECAST HIGHS WITHIN A DEGREE OR THREE OF 90 SATURDAY
THROUGH MONDAY...THEN 85 TO 90 TUESDAY. OVERNIGHT LOWS WITHIN A
DEGREE OR THREE OF 70 EACH DAY...EXCEPT WARMER MONDAY NIGHT
ANTICIPATING MORE CLOUDS IN A VERY MOIST AIR MASS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 725 AM WEDNESDAY....
SHOWERS AND A FEW ISOLATED THUNDERSTORMS CONTINUE TO MOVE SOUTHWEST
TO NORTHEAST ACROSS THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
MORNING...WITH A FEW OF THE SHOWERS IN THE VICINITY OF KFAY.
HOWEVER...LITTLE IMPACT IS EXPECTED OTHER THAN POSSIBLY A BRIEF
PERIOD OF MVFR CEILINGS OR VSBYS THROUGH 15Z. THESE SHOWERS ARE
EXPECTED TO CONTINUE MOVING NORTHEAST ACROSS THE COASTAL PLAIN AND
EVENTUALLY OFFSHORE BY EARLY AFTERNOON. THERE IS SOME UNCERTAINTY
AS TO WHETHER OR NOT THEY WILL DEVELOP AS FAR NORTH AS KRWI AND
KRDU...BUT IF THEY DO THEN A SHOWER/STORM WILL BE POSSIBLY BETWEEN
13-16Z. OUTSIDE OF THESE SHOWERS/STORMS....VFR CONDITIONS ARE
GENERALLY EXPECTED.
LATER THIS AFTERNOON...AN UPPER LEVEL DISTURBANCE APPROACHING FROM
THE NORTHWEST SHOULD TRIGGER SOME STORMS ALONG THE NC/VA
MOUNTAINS...A FEW OF WHICH MAY MOVE SOUTHEAST INTO THE WESTERN
PIEDMONT AFTER 20Z. HOWEVER....THERE IS LOW CONFIDENCE IN EXACTLY IF
OR WHEN KINT/KGSO WOULD BE TERMINAL COULD BE IMPACTED.
LOOKING AHEAD:
AFTERNOON STORMS AND EARLY MORNING STRATUS/FOG WILL BE POSSIBLE EACH
DAY THROUGH THE WEEKEND...WITH A BETTER CHANCE OF STORMS EARLY NEXT
WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...SMITH/DJF
LONG TERM...DJF
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
307 AM EDT WED AUG 1 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE SOUTHEAST INTO THE
CAROLINAS THROUGH THURSDAY. UPPER LEVEL HIGH PRESSURE WILL THEN
BUILD INTO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...
THIS MORNING...
COMPLICATED UPPER LEVEL FLOW CONTINUES OVER THE REGION WITH
NUMEROUS DISTURBANCES ROTATING THROUGH THE BASE OF THE UPPER LEVEL
TROUGH...WHICH CURRENTLY EXTENDS ALL THE WAY SOUTH INTO SOUTHERN
GA. THE MOST NOTABLE VORTICES WERE LOCATED OVER EASTERN
NC...UPSTATE SC...AND WESTERN VA. RECENT RADAR TRENDS SUGGEST THE
BROKEN LINE OF CONVECTION OVER VA WILL CONTINUE TO MOVE SLOWLY
EASTWARD AND THE OUTFLOW MAY BE THE FOCUS FOR SHOWERS OVER THE
NORTHERN COASTAL PLAIN DURING THE NEXT COUPLE OF HOURS. TO THE
SOUTH... SCATTERED SHOWERS AND A COUPLE THUNDERSTORMS ARE
EXPANDING NORTHWARD OUT OF SC INTO THE SOUTHERN PIEDMONT AND
SANDHILLS. A WEAK LOW PRESSURE CENTER IS FORECAST TO DEVELOP NEAR
THE SAVANNAH RIVER BASIN IN RESPONSE TO THE DPVA APPROACHING A
STALLED OUT...WEAK FRONTAL ZONE OVER THE SC/NC COASTAL REGIONS.
HOWEVER... IT IS HARD TO DETECT AN ACTUAL LOW SO FAR. 00Z RAOBS
FROM KMHX AND KCHS SHOW A FAIR AMOUNT OF ELEVATED INSTABILITY FOR
THE ONGOING SHOWERS TO FEED ON...AND THE HRRR SEEMS TO BE HANDLING
THE TIMING OF THE PRECIP WELL..ALTHOUGH THE RADAR ECHOES EXTEND
FURTHER WEST THAN THE SIMULATIONS. OVER THE NEXT 3-6
HOURS...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED STORMS...ALONG
WITH MORE DEVELOPMENT BACK TO THE SOUTHWEST...SHOULD CONTINUE TO
MOVE TO THE NORTHEAST TO THE EAST OF US HWY 1...WITH MORE ISOLATED
SHOWERS POSSIBLE FURTHER WEST.
WHILE AN AXIS OF AROUND 1000 J/KG OF MUCAPE WILL EXIST THIS
MORNING...THE THREAT IF ANY SEVERE WEATHER IS LOW THROUGH MIDDAY
GIVEN THE WEAK DEEP LAYER FLOW IN THE TROUGH. IF/WHEN THE SURFACE
LOW DEVELOPS AND MOVES NORTHEAST ALONG THE COAST...THE MAY BE A
SHORT WINDOW WHERE LOW LEVEL SHEAR IS ENHANCED...BUT THE 0-1KM AND
0-3KM FLOW JUST LOOKS TOO WEAK FOR THE SMALL TORNADIC CONCERNS THAT
MODELS HAD SHOWN IN PREVIOUS RUNS.
THIS AFTERNOON...
AS THE AXIS OF DEEPER MOISTURE MOVES OFFSHORE...CONVECTION SHOULD
COME TO AN END OVER THE COASTAL PLAIN. ANOTHER UPPER DISTURBANCE
CURRENTLY OVER THE UPPER MIDWEST WILL DIVE INTO THE BACK SIDE OF
THE TROUGH THIS EVENING AND MAY KICK OFF SOME STORMS OVER THE
MOUNTAINS. HOWEVER...MUCH DRIER AIR ALOFT APPROACHING FROM THE
WEST...NOTED ON WATER VAPOR IMAGERY...SHOULD KEEP ANY STORMS
ISOLATED TO WIDELY SCATTERED OVER THE WESTERN PIEDMONT AND MAINLY
AFTER 20Z.
FULL HEATING WOULD SUPPORT HIGHS AROUND 90 TO THE WEST OF US HWY 1
THIS AFTERNOON. TO THE EAST...CLOUD COVER AND SHOWERS ARE GOING TO
LIMIT HEATING THIS MORNING...THOUGH THE EXPECTED DRYING ALOFT AND
THINNING OF CLOUDS FROM THE WEST SHOULD ALLOW MOST AREAS TO REACH
THE MID 80S.
TONIGHT...
OUTSIDE OF THE POTENTIAL FOR A FEW SHOWERS/STORMS MOVING
OFF THE HIGHER TERRAIN TO MAKE IT INTO THE PIEDMONT...CONDITIONS
SHOULD BE RELATIVELY QUIET WITH LOWS IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...
THURSDAY AND THURSDAY NIGHT...
A WEAK UPPER LEVEL LOW/SHEAR AXIS IS FORECAST TO BREAK OFF FROM
THE UPPER TROUGH AND SLIP SOUTH TOWARD THE SC COAST ON THURSDAY.
THE FOCUS FOR CONVECTION WILL MAINLY BE ALONG THE COAST...WITH
WEAK ANTICYCLONIC FLOW AND DRIER AIR ALOFT OVER MUCH OF CENTRAL
NC. MAINLY A SLIGHT CHANCE OF SHOWERS/STORMS SOUTH AND EAST OF THE
TRIANGLE DURING THE AFTERNOON. LOW LEVEL THICKNESSES GENERALLY
SUPPORT LOWER 90S AREA WIDE. WITH LITTLE CLOUD COVER
OVERNIGHT...TEMPS SHOULD FALL QUICKLY TO THE UPPER 60S TO LOWER
70S...AND STRATUS/FOG MAY BE AN ISSUE.
FRIDAY AND FRIDAY NIGHT...
THE NAM AND THE GFS ARE FAIRLY CONSISTENT IN FORECASTING A WEAK
UPPER LOW OR SHEAR AXIS TOWARD THE COASTAL PLAIN AND THE CAROLINA
COAST. UNDER A BROAD SOUTHERLY FLOW FROM THE SURFACE THROUGH
850MB...MEAN MOISTURE GRADUALLY INCREASES...AND PRECIPITABLE WATER
VALUES THAT ARE AROUND 1.5 INCHES FRIDAY MORNING ARE FORECAST TO
INCREASE TO AROUND 1.75 INCHES BY 00Z SATURDAY. 250MB WINDS
DIMINISH AND WINDS FROM 850MB THROUGH 500MB ARE LIGHT... ONLY
AROUND 10KT AT BEST...MAKING FOR 0-6KM SHEAR VALUES ALSO AROUND
10KT AT BEST. WEAK LIFT IS FORECAST...BUT MUCH OF CENTRAL NORTH
CAROLINA MAY LIE JUST ON THE WEST SIDE OF THE UPPER LOW OR SHEAR
AXIS...AND NAM AND GFS BUFR SOUNDINGS SHOW A COUPLE OF DEGREES OF
MID- AND UPPER-LEVEL WARMING DURING THE DAY FRIDAY. WITH SLIGHT
MOISTURE ADVECTION...AND SOME UNCERTAINTY IN THE OVERALL LOCATION
OF THE WEAK UPPER-LEVEL FEATURES...THERE SHOULD BE ENOUGH
INSTABILITY... AROUND 1000J/KG OF MLCAPE...THAT A SEA BREEZE IN
THE SOUTHERLY FLOW...FOR EXAMPLE...COULD PROVIDE AN ISOLATED
SHOWER OR THUNDERSTORM. SLIGHT CHANCES WERE IN THE FORECAST AND
WILL NOT REMOVE THOSE...BUT CURRENTLY THINK THAT ISOLATED TO
WIDELY SCATTERED COVERAGE AT BEST WOULD OCCUR FRIDAY AFTERNOON
INTO FRIDAY EVENING.
BOTH THE NAM AND THE GFS PROVIDE FOR LIGHT QPF TOWARD AND WEST OF
THE YADKIN RIVER FRIDAY NIGHT...THOUGH BUFR SOUNDINGS WOULD TEND TO
SUPPORT MORE STABILITY AND THE TYPICAL DIURNAL MIN IN TERMS OF
CHANCES OF RAINFALL. THE GFS...AND TO SOME DEGREE THE NAM...FORECAST
A MODERATELY-STRONG MID-LEVEL SHORTWAVE MOVING INTO THE APPALACHIANS
LATE FRIDAY NIGHT...WHICH MAY BE A RESULT OF CONVECTIVE FEEDBACK.
THE SOUTHERLY 850MB FLOW IS FORECAST BY THE GFS TO STRENGTHEN NEAR
THE MOUNTAINS LATE FRIDAY NIGHT...SO AS THE AIR MASS MOISTENS IT IS
POSSIBLE FOR OVERNIGHT DEVELOPMENT OF SOME DEEP CONVECTION THERE...
THOUGH THE THERMAL WIND WOULD SEEM TO INDICATE A GENERAL MOTION
KEEPING MOST ACTIVITY WEST OF CENTRAL NORTH CAROLINA. WILL NOT
INTRODUCE ANY SLIGHT CHANCES FOR A SHOWER OR THUNDERSTORM OVERNIGHT
FRIDAY...THOUGH TRENDS WILL NEED TO BE WATCHED PARTICULARLY WITH
REGARD TO THE LOCATION AND STRENGTH OF ANY MID-LEVEL WAVE.
1000-850MB THICKNESSES SUPPORT THE SLIGHTLY COOLER MAV GUIDANCE FOR
HIGHS FRIDAY...MAINLY 90 TO 95. LOWS FRIDAY NIGHT AROUND 70.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...
THERE SEEM TO BE SOME CHANGES IN THE UPPER-AIR PATTERN AS
FORECAST BY THE GFS AND ECMWF...MOST NOTABLY HIGHER HEIGHTS ALOFT
OFFSHORE OF THE MID-ATLANTIC EARLY IN THIS PART OF THE LONG-TERM
PERIOD. AT THE SAME TIME...THE LOW-LEVEL FLOW AROUND BROAD BERMUDA
HIGH PRESSURE IS MORE SOUTHERLY ESPECIALLY EARLY IN THIS PART OF
THE LONG-TERM PERIOD...SUCH THAT THE MEAN AIR MASS IS GENERALLY
MORE MOIST THAN APPARENTLY WAS THE CASE AS FORECAST BY PREVIOUS
GUIDANCE. CERTAINLY THE TREND INTO EARLY NEXT WEEK
CONTINUES...WITH LOWERING HEIGHTS ALOFT AFTER THE WEEKEND AS AN
UPPER TROUGH MOVES EAST ACROSS THE GREAT LAKES AND SOUTHEAST
CANADA...EXTENDING INTO THE MID-ATLANTIC. BOTH THE GFS AND ECMWF
FORECAST A TROUGH AXIS ALOFT MOVING INTO CENTRAL NORTH CAROLINA
WITH A SHEAR AXIS LINGERING INTO TUESDAY. THE DGEX IS ALSO SIMILAR
IN REGARD TO THIS.
ANOTHER CONTINUING TREND OF THE CONSENSUS OF THE GFS AND ECMWF IS
THE GRADUAL INCREASE IN PRECIPITABLE WATER VALUES FROM SATURDAY
THROUGH MONDAY INTO TUESDAY. VALUES AROUND 1.75 INCHES OR SO
SATURDAY CLIMB TO AT OR JUST ABOVE TWO INCHES BY MONDAY AND
CONTINUE FOR THE MOST PART INTO TUESDAY...WITH POSSIBLY SOME
DRYING OVER THE NORTHWEST PIEDMONT LATE ON TUESDAY BASED ON THE
COARSE MODEL SOUNDINGS FROM THE GFS AND ECMWF. FOR THIS FORECAST...
MADE LITTLE CHANGES TO THE PREVIOUS FORECAST IN TERMS OF CHANCES FOR
PRECIPITATION...LOWER CHANCE PROBABILITIES FOR SATURDAY...GRADUALLY
INCREASING TO AROUND 40 PERCENT MONDAY WITH CHANCES CONTINUING
OVERNIGHT MONDAY NIGHT THROUGH TUESDAY NIGHT IN BETTER SYNOPTIC
FORCING ALOFT AS HEIGHTS FALL WITH THE ATTENDANT SHORTWAVE OR SHEAR
AXIS. THE HIGHEST CHANCES WILL BE FORECAST MONDAY...WHEN THERE
SHOULD BE THE BEST MID-LEVEL VORTICITY ADVECTION AND WHERE THE
GUIDANCE FORECASTS THE BEST LIFT. THE GFS HAS TRENDED SLIGHTLY
FASTER WITH THE TROUGH AXIS TUESDAY INTO TUESDAY NIGHT...AND FOR
THEN WILL NOTE HIGHER CHANCES...RELATIVE TO THE REST OF CENTRAL
NORTH CAROLINA...SOUTH AND EAST OF THE TRIAD. 1000-850MB THICKNESSES
HAVE TRENDED LOWER FROM RECENT DAYS IN THIS PART OF THE FORECAST...
AND WILL FORECAST HIGHS WITHIN A DEGREE OR THREE OF 90 SATURDAY
THROUGH MONDAY...THEN 85 TO 90 TUESDAY. OVERNIGHT LOWS WITHIN A
DEGREE OR THREE OF 70 EACH DAY...EXCEPT WARMER MONDAY NIGHT
ANTICIPATING MORE CLOUDS IN A VERY MOIST AIR MASS.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM WEDNESDAY....
SHOWERS AND A COUPLE THUNDERSTORMS ARE BEGINNING TO EXPAND
NORTHEASTWARD ACROSS CENTRAL SC IN TO SOUTHERN NC. THIS AREA OF
PRECIP SHOULD CONTINUE TO MOVE NORTHEAST TOWARD KFAY OVER THE NEXT
HOUR OR TWO...AND CONTINUE THROUGH AT LEAST 12Z. A PERIOD OF
MVFR/IFR VSBYS AND CEILINGS CAN BE EXPECTED WITH THE HEAVIER
SHOWERS. ELSEWHERE...VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH
THE 12Z...THOUGH CEILINGS AND VSBYS MAY LOWER TO MVFR AT KRDU AND
KRWI JUST PRIOR TO SUNRISE.
SHOWERS AND ISOLATED STORMS WILL SPREAD NORTHEAST THROUGH THE
COASTAL PLAIN DURING THE MORNING HOURS...MAINLY TO THE EAST OF KRWI
BASED ON THE MOST RECENT MODEL GUIDANCE. HOWEVER...IT IS POSSIBLE
THAT SHOWERS/STORMS MAY BE NEAR KRWI DURING THE 12-16Z TIME FRAME.
ONCE THIS ARE OF PRECIP MOVES OFF TO THE NORTHEAST BY LATE
MORNING...CONDITIONS ARE EXPECTED TO IMPROVE AT KRWI/KFAY/KRDU FOR
THE REMAINDER OFT HE TAF PERIOD. FURTHER WEST...SHOWERS AND STORMS
MAY DEVELOP ALONG THE MOUNTAINS AND PUSH EAST TOWARD KGSO/KINT LATE
TODAY...MOST LIKELY AFTER 20Z. HOWEVER....THERE IS LOW CONFIDENCE IN
EXACTLY IF OR WHEN EITHER TERMINAL COULD BE IMPACTED.
LOOKING AHEAD:
EXPECT A RELATIVELY TYPICAL SUMMER-TIME PATTERN CONSISTING OF
ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...AND A POTENTIAL FOR FOG/STRATUS DURING THE PRE-DAWN
HOURS (ROUGHLY 06-12Z) EACH DAY THROUGH THE REMAINDER OF THE WEEK
INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...SMITH/DJF
LONG TERM...DJF
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
335 PM CDT WED AUG 1 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...
MAIN FOCUS OF THE SHORT TERM IS CHANCES OF THUNDERSTORMS TONIGHT IN
THE NORTH...THEN THE CHANCE OF MORE WIDESPREAD THUNDERSTORMS WITH
SEVERE POSSIBILITIES THURSDAY AFTERNOON/NIGHT.
CURRENTLY...SURFACE LOW PRESSURE WAS OVER EASTERN WYOMING WITH A
FRONT/TROUGH EXTENDING EASTWARD ACROSS CENTRAL SOUTH DAKOTA. ONGOING
CONVECTION FROM MID-LEVEL BASED SHOWERS AND THUNDERSTORMS CONTINUED
MOVING EASTWARD ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THIS
ACTIVITY SHOULD BE EAST OF THE FORECAST AREA BY 7 PM.
THE MAIN FOCUS FOR THIS EVENING INVOLVES THE LATEST WATER VAPOR SAT
IMAGERY THAT SHOWS ROTATION DEPICTING AN UPPER LEVEL SHORTWAVE
MOVING EASTWARD ACROSS SOUTHERN SASKATCHEWAN. AN IMPULSE FROM THIS
SHORTWAVE APPEARS TO BE ASSOCIATED WITH A STRONG/SEVERE THUNDERSTORM
THAT DEVELOPED OVER CENTRAL/SOUTHERN SASKATCHEWAN. THIS STORM WAS
MOVING SOUTHEASTWARD TOWARDS THE FAR NORTHEASTERN COUNTIES OF
MONTANA. A FEW OTHER CONVECTIVE CELLS HAVE DEVELOPED AHEAD OF THIS
STORM AS WELL. THE LATEST HRRR MODEL DEPICTS THIS UPPER LEVEL
IMPULSE TO MOVE EAST ALONG THE NORTHERN TIER OF COUNTIES OF NORTH
DAKOTA EARLY THIS EVENING. THUS HAVE ADDED A MENTION OF SLIGHT
CHANCE OF THUNDERSTORMS EARLY THIS EVENING ACROSS NORTHWESTERN AND
NORTH CENTRAL NORTH DAKOTA.
SHOULD BE CLEARING SKIES LATER THIS EVENING WITH OVERNIGHT LOWS FROM
THE UPPER 50S TO LOWER 60S.
ATTENTION THEN TURNS TO THURSDAY...WITH THE APPROACH OF A LARGE
UPPER LEVEL LOW AND SHORTWAVE TROUGH THAT WILL AFFECT WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY AFTERNOON INTO SATURDAY. A SURFACE
TROUGH DEVELOPS IN THE LEE OF THE ROCKIES IN RESPONSE TO THE UPPER
LEVEL LOW/WAVE...WHICH MOVES SOUTH OUT OF ALBERTA THURSDAY AFTERNOON
AND DIVES SOUTHEAST INTO MONTANA BY FRIDAY MORNING. OUT AHEAD OF
THIS ALBERTA CLIPPER SYSTEM...AN UPPER LEVEL IMPULSE MOVES
EASTWARD INTO THE DAKOTAS THURSDAY AFTERNOON...AND MOVES ACROSS THE
STATE THURSDAY NIGHT. IN RESPONSE...THE SURFACE TROUGH IS PROGGED TO
DEVELOP OVER EASTERN MONTANA THURSDAY MORNING AND MOVE INTO WESTERN
NORTH DAKOTA THURSDAY AFTERNOON...MOVING EASTWARD INTO CENTRAL NORTH
DAKOTA THURSDAY NIGHT.
THIS SCENARIO WILL PROVIDE PLENTY OF WIND SHEAR AND LOW LEVEL
MOISTURE AHEAD AND ALONG THE SURFACE TROUGH FOR SOME STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP. KEPT THURSDAY MORNING DRY IN THE
FORECAST...WITH A CHANCE OF THUNDERSTORMS THURSDAY AFTERNOON OVER
MAINLY WESTERN NORTH DAKOTA IN THE VICINITY OF THE SURFACE TROUGH.
THURSDAY NIGHT CHANCES INCREASE AND HAVE KEPT THE 60 PERCENT
"LIKELY" CATEGORY FOR THE EASTERN PART OF CENTRAL NORTH DAKOTA LATE
THURSDAY NIGHT.
STORM PREDICTION CENTER DOES HAVE OUR AREA IN A SLIGHT RISK FOR
SEVERE THUNDERSTORMS THURSDAY AFTERNOON/NIGHT FOR THE WESTERN
DAKOTAS...AND FOR THE EASTERN DAKOTAS ON FRIDAY. STRONG HEATING
AHEAD OF THE MAIN SYSTEM WILL ALLOW TEMPERATURES TO RISE INTO THE
UPPER 80S/LOWER 90S THURSDAY...WITH LOWS THURSDAY NIGHT 60 TO 65.
STRONG COLD FRONT BEHIND THE SYSTEM FOR A COOLER WEEKEND.
.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
THE EXTENDED PERIOD BEGINS WITH A SFC TROUGH OVER THE DAKOTAS AND A
STRONG UPPER LEVEL LOW APPROACHING THE NORTHERN PLAINS. WILL LIKELY
SEE ONGOING PRECIPITATION FROM THURSDAY NIGHT AT THE VERY START OF
THE PERIOD. CHANCES FOR SHOWERS ARE LIKELY OVER CENTRAL AND EASTERN
NORTH DAKOTA...WITH A GOOD CHANCE ACROSS THE WEST FRIDAY DAYTIME. I
DID SCALE BACK ON THUNDER WORDING FROM WEST TO CENTRAL FRIDAY
MORNING INTO FRIDAY AFTERNOON AS WE STABILIZE ONCE THE UPPER LOW
ADVECTS INTO WESTERN ND. MODELS SHOWING AN ENHANCED POSSIBILITY OF
STRONG TO SEVERE WEATHER EAST OF HIGHWAY 83 FRIDAY DAYTIME. WILL
MENTION IN THE HWO. WRAP AROUND PRECIPITATION...ESPECIALLY ACROSS
THE NORTH...FRIDAY NIGHT INTO SATURDAY WITH THE LOW PROPAGATING EAST
ALONG THE INTERNATIONAL BORDER. MAINTAINED A SLIGHT CHANCE OF
THUNDER FRIDAY NIGHT...AND WENT ALL SHOWERS SATURDAY DAYTIME WITH
LITTLE IF ANY CAPE. TEMPERATURES WILL BE NOTICEABLY COOLER FRIDAY
AND SATURDAY DUE TO THE CLOUDS...PRECIP...AND STRONG CAA ASSOCIATED
WITH THE LOW. HIGHS FRIDAY WILL CLIMB INTO THE 80S AHEAD OF THE SFC
TROUGH OVER MY SOUTHEAST...BUT SHOULD REMAIN IN THE 70S ELSEWHERE.
HIGHS SATURDAY WILL CONTINUE TO BE WELL BELOW AVERAGE...FROM AROUND
70 EAST TO NEAR 75 WEST.
HIGH PRESSURE WILL KEEP THINGS DRY SATURDAY NIGHT THROUGH SUNDAY
NIGHT ALONG WITH A WARMING TREND BEGINNING. HIGHS SUNDAY SHOULD BE
ABOUT 10-15 DEGREES WARMER THAN SATURDAY.
NORTHWESTERLY FLOW ALOFT IS DEPICTED MON-WED. THIS WILL HELP KEEP
THE REAL WARM AIR WEST AND SOUTH OF THE STATE MONDAY AND TUESDAY
RESULTING IN NEAR NORMAL HIGHS AND LOWS. WILL ALSO MAINTAIN A DRY
FORECAST FOR NOW MONDAY-WEDNESDAY. WHILE IT IS POSSIBLE A WEAK
EMBEDDED WAVE COULD DEVELOP ISOLD-SCT SHOWERS/THUNDER...TOO
UNCERTAIN RIGHT NOW TO INTRODUCE WEATHER INTO THE FORECAST.
&&
.AVIATION...
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH THE 18Z TAF ISSUANCE
PERIOD. A MID LEVEL DISTURBANCE CONTINUES TO BRING EXTENSIVE CLOUD
COVER TO WEST AND CENTRAL NORTH DAKOTA ALONG WITH SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS. CLOUD BASES REMAIN RELATIVELY HIGH AT
AROUND 10K FT AGL...OCCASIONALLY DROPPING TO NEAR 4K FT AGL IN
SHRA/TSRA. WILL CONTINUE THE MENTION OF VCTS/VCSH DUE TO THE ISOLD
NATURE OF THE PRECIPITATION. WILL ISSUE TEMPO GROUPS AS NEEDED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM/AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
318 PM CDT WED AUG 1 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY
PRIMARY FORECAST CHALLENGE IS SHORT-TERM PRECIPITATION CHANCES...
FOLLOWED BY FRIDAY/S SYSTEM. GFS/NAM/ECMWF/GEM ARE IN REASONABLE
AGREEMENT...BUT HAVE HANDLED TODAY/S SHOWERS AND STORMS POORLY.
LATEST HRRR BEST REFLECTS CURRENT SITUATION AND WILL FOLLOW ITS
SOLUTION FOR THE NEXT 6-12 HOURS.
20 UTC RADAR LOOP SHOWS TWO AREAS OF PRECIPITATION. THE FIRST IS
A LINE OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS FROM GLENDIVE
MT TO NEAR DEVILS LAKE...MOVING EAST AROUND 35 KTS. THE SECOND IS
A LINE OF SHOWERS AND THUNDERSTORMS FROM WALL SD TO ORTONVILLE
MN...ALSO MOVING TO THE EAST AROUND 35 KTS. BOTH BANDS ARE
ASSOCIATED WITH AN UPPER LEVEL SHORT-WAVE CROSSING INTO WESTERN
ND...BUT WEAK INSTABILITY ACROSS MUCH OF ND IS LIMITING
THUNDERSTORM ACTIVITY. MAJORITY OF THUNDERSTORMS SHOULD REMAIN
SOUTH OF THE ND/SD STATE LINE ALONG 2000 TO 3000 J/KG MLCAPE
INSTABILITY AXIS.
LATEST HRRR BRINGS SHOWERS AND ISOLATED THUNDERSTORMS ACROSS
CENTRAL ND MAINLY INTO THE CENTRAL/NORTHERN VALLEY AND THEN PORTIONS
OF NORTHWEST MN LATE THIS AFTERNOON AND EVENING. EXPANDED 20 POPS
INTO THESE AREAS THROUGH 03 UTC. WITH NO OTHER MODEL ACCURATELY
REFLECTING THIS SCENARIO...UNCERTAIN HOW LONG SHOWERS WILL HOLD
TOGETHER AND WILL KEEP FORECAST DRY ACROSS THE NORTH AFTER 03 UTC.
DID ADD AN AREA OF 20 POPS ACROSS THE FAR SOUTH AS WELL THROUGH 06
UTC TO CATCH ANY STRAY ACTIVITY FROM SD CROSSING THE BORDER THIS
EVENING. NO SEVERE WEATHER IS EXPECTED AT THIS TIME.
SURFACE HIGH PRESSURE BUILDS ACROSS THE CWA BY 12 UTC THURSDAY...
SO SHOULD SEE DECREASING CLOUDS AND LIGHT WIND ALLOWING MORNING
LOWS TO DROP INTO THE UPPER 50S TO LOWER 60S. THE REST OF THE DAY
WILL BE DRY WITH A MIX OF SUN AND CLOUDS AND TEMPERATURES SIMILAR
TO TODAY.
ATTENTION THEN TURNS TO THURSDAY NIGHT THROUGH SATURDAY AS A
STRONG CANADIAN CLOSED LOW MOVES ACROSS THE NORTHERN PLAINS.
PRIMARY CHANGE TO PREVIOUS FORECAST WAS TO SLOW EASTWARD
PROGRESSION OF POPS. GFS/ECMWF IN GOOD AGREEMENT...SUGGESTING BEST
FORCING WILL BE ALONG MID-LEVEL TROUGH WITH ADDITIONAL SUPPORT
FROM A 50 TO 80 KT 300 HPA JET ROUNDING THE BASE OF THE UPPER LOW.
SPREAD 60 TO 70 POPS FROM WEST TO EAST THURSDAY NIGHT THROUGH
EARLY SATURDAY MORNING WITH THE BEST CHANCE FOR ACCUMULATING
RAINFALL ALONG THE VALLEY FRIDAY AFTERNOON. STILL TO EARLY TO
PINPOINT MOST FAVORED AREA FOR SEVERE CONVECTION...BUT LATEST
GFS/ECMWF DO DEVELOP SOME KIND OF MCS ACROSS SOUTHEAST ND FRIDAY
AFTERNOON. SPC DAY 3 CONVECTIVE OUTLOOK PAINTS A SLIGHT RISK
ACROSS THE ENTIRE CWA EXCEPT THE FAR WESTERN DEVILS LAKE BASIN.
SOMETHING TO WATCH CLOSELY OVER THE NEXT SEVERAL MODEL RUNS.
COLD FRONT WILL MOVE WELL EAST OF THE AREA FOR SATURDAY...USHERING
IN A CHANGE OF AIR MASS. HIGHS SATURDAY ONLY EXPECTED TO REACH THE
UPPER 60S TO LOWER 70S WITH PERIODS OF SCATTERED WRAP AROUND RAIN
SHOWERS. WINDS WILL ALSO BE BREEZY FROM THE NORTHWEST WITH
OCCASIONAL GUSTS TO 30 MPH.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
LONG RANGE MODELS AGREEABLE THROUGH MONDAY...THEN DIVERGE.
NORTHWEST FLOW ALOFT APPEARS LIKELY THROUGH THE PERIOD AS UPPER
RIDGE TO THE WEST GRADUALLY PROPAGATES TO THE EAST. MODELS
INDICATE A CANADIAN UPPER LOW SENDING A COLD FRONT THROUGH THE
REGION ON MONDAY...BUT DRY AIRMASS SHOULD LIMIT PRECIP. MONDAY HAS
THE POTENTIAL TO BE THE WARMEST DAY...DEPENDING ON THE FROPA
TIMING. THE ECMWF IS WEAKER WITH THE UPPER RIDGE AND DOES ALLOW
FOR SOME WAVES TO ROUND THIS FEATURE BY LATER IN THE PERIOD. WILL
CONTINUE WITH DRY FORECAST WITH SFC RIDGING AND DRY AIRMASS
EXPECTED.
&&
.AVIATION...
VFR CIGS THROUGH THE PERIOD. ISOLATED SHOWERS POSSIBLE INTO THE
EVENING...BUT WILL BE VERY LIGHT. WINDS WILL BECOME LIGHT THIS
EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
107 AM EDT WED AUG 1 2012
.SYNOPSIS...
UPPER LEVEL DISTURBANCE THIS AFTERNOON INTO TONIGHT. COLD FRONT
MOVES THROUGH WEDNESDAY. HIGH PRESSURE WEDNESDAY NIGHT THROUGH
FRIDAY. COLD FRONT ARRIVES LATER SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...SHOWERS/STORMS WINDING DOWN ACROSS THE FORECAST
AREA AS LACK OF REGENERATION ALLOWED ONGOING CONVECTION TO FINALLY
BEGIN MOVING OFF TO THE EAST. CURRENT SHOWERS OVER FAR EASTERN HIGH
TERRAIN WILL END OVER THE NEXT HOUR OR TWO. THOUGH MOST LOCATIONS
WILL REMAIN DRY...WILL CONTINUE A SLIGHT CHANCE OF RAIN SHOWERS
OVERNIGHT FOR MUCH OF THE AREA WITH BOTH THE RUC AND NAM DEPICTING
ANOTHER VORT MAX PUSHING SE-WARD ACROSS OHIO...WITH SOME LLVL
MOISTURE IN PLACE ALONG WITH EXISTING MESOSCALE OUTFLOW BOUNDARIES
FROM THIS EVENING/S STORMS.
PREVIOUS DISCUSSION...
NUMEROUS SHOWERS AND THUNDERSTORMS CURRENTLY DEPICTED BY RADAR
OVER NORTHERN WV MOUNTAINS...WITH MORE ISOLATED ACTIVITY SOUTHWARD
OVER THE MOUNTAINS. RAP SHOWS A VORT MAX ASSOCIATED WITH THIS
ACTIVITY...WHICH PUSHES OFF TO THE EAST THROUGH THE
AFTERNOON...WITH A SECOND VORT MAX MOVING IN FROM THE WEST. STILL
WAITING FOR SIGNS OF THE SECOND WAVE TO SHOW...AS AN OUTFLOW
BOUNDARY FROM EARLIER CONVECTION IN NORTHERN INDIANA ALSO MOVES
IN. VISIBLE SAT SHOWED SOME BUILDING CUMULUS CLOUDS IN PERRY
COUNTY...UP TOWARDS PBZ...ALONG THIS BOUNDARY BUT IT HAS BEEN
FAIRLY SLOW TO CONTINUE DEVELOPMENT. EXPECTING MORE DEVELOPMENT AS
THIS BOUNDARY PUSHES INTO CWA...WHERE THERE HAS BEEN A GOOD AMOUNT
OF HEATING SO FAR TODAY. INTERESTINGLY...THE WRFNMM SHOWS AN
OUTFLOW BOUNDARY COMING WEST OUT OF THE ACTIVITY NEAR
EKN...MEETING THE BOUNDARY APPROACHING FROM THE
NORTHEAST...DEVELOPING PRETTY ROBUST CONVECTION ALONG I-79. WILL
HAVE TO WAIT AND SEE JUST HOW THIS GOES...BUT AT ANY RATE...EXPECT
ISOLATED TO SCATTERED SHOWERS AND STORMS THIS AFTERNOON. ISOLATED
SHOWERS AND STORMS MAY LINGER OVERNIGHT...WITH SCATTERED STORMS
AGAIN WEDNESDAY AS ANOTHER UPPER LEVEL SHORTWAVE TROUGH PASSES
THROUGH.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
MODELS SHOW A BRIEF LULL IN THE ACTIVE THUNDERSTORM PATTERN AS AN
UPPER LEVEL DISTURBANCE IN NORTHWEST FLOW ALOFT EXITS TO THE
SOUTHEAST AND ALLOWS WEAK HIGH PRESSURE TO BUILD IN FOR WEDNESDAY
NIGHT AND THURSDAY. THIS WILL ALLOW DRIER AIR TO OVERSPREAD THE
AREA...THOUGH TEMPERATURES THURSDAY WILL BE SIMILAR TO WEDNESDAY.
HOWEVER...WITH THE DRIER AIR...WEDNESDAY NIGHT WILL BE SOMEWHAT
COOLER THAN PREVIOUS NIGHTS. LOOK FOR TEMPERATURES TO REACH AROUND
90 DEGREES MANY LOW LAND LOCATIONS AGAIN THURSDAY...BUT LESS
HUMIDITY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HEIGHTS ONCE AGAIN BUILD IN FROM THE WEST BY FRIDAY WITH THE BERMUDA
HIGH STRENGTHENING...ALLOWING THE HEAT AND HUMIDITY TO MOVE BACK IN
FROM THE SOUTHWEST. CHANCES FOR STORMS INCREASE LATER FRIDAY AND
SATURDAY ON MORE OF A DIURNAL BASIS WITH THE INCREASING INSTABILITY.
THIS WILL ALSO BRING MORE HEAT BACK...WITH HIGH TEMPERATURES FRIDAY
AND SATURDAY REACHING INTO THE 90S AGAIN.
ANOTHER STRONGER NORTHWEST FLOW SYSTEM AND ATTENDING COLD FRONT DROP
SOUTHEASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THIS WILL
INCREASE CHANCES FOR STORMS SUNDAY AND SUNDAY NIGHT AHEAD OF THE
FRONT. MODELS ARE SOMEWHAT DIFFERENT IN TIMING OF THE SYSTEM...BUT
SUING THE SLOWER EURO AND GFS MODELS IN THIS HIGH SUMMER PATTERN LOOKS
REASONABLE. THIS WILL PUSH THE FRONT THROUGH MONDAY MORNING WITH
SHOWERS DECREASING FROM NORTHWEST TO SOUTHEAST ON MONDAY...FOLLOWED
BY SLIGHTLY COOLER TEMPS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
PATCHY DENSE FOG CAN BE EXPECTED EARLY THIS MORNING IN AREAS THAT
RECEIVED RAINFALL TODAY. A WEAK COLD FRONT WILL SLOWLY MOVE ACROSS
THE AREA TODAY. SHOWERS AND THUNDERSTORMS REMAIN A POSSIBILITY ALONG
AND EAST OF THE FRONT. AFTER THE FOG BURNS OFF BY MID MORNING...VFR
CONDITIONS WILL PREVAIL OUTSIDE OF SHOWERS AND THUNDERSTORMS. PATCHY
DENSE FOG IS POSSIBLE AGAIN LATE WEDNESDAY NIGHT...MORE LIKELY IN
THE MOUNTAIN VALLEYS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS COULD VARY.
TIMING AND DENSITY OF FOG COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 08/01/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M M H H M H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L L L H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY L L L L L L L L H H H H
AFTER 06Z THURSDAY...
IFR POSSIBLE IN DENSE FOG IN THE MOUNTAIN VALLEYS LATE WEDNESDAY
NIGHT AND THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ
NEAR TERM...MZ/50
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS TULSA OK
931 PM CDT THU AUG 2 2012
...UPDATE...
.DISCUSSION...
WELL DEFINED OUTFLOW BOUNDARY HAS PUSHED TO NEAR A PAWNEE TO JAY
LINE...AND CONTINUES TO SLOWLY WORK SOUTHWARD. ISOLATED CONVECTION
HAS RECENTLY FIRED ALONG THE BOUNDARY BOTH ACROSS NE OK / NW AR
BUT ALSO FURTHER WEST ACROSS NW OK. WILL MAINTAIN LOW PRECIP
CHANCES OVERNIGHT THOUGH COVERAGE WILL LIKELY REMAIN RATHER LOW.
ALSO UPDATED WINDS NEARER THE RUC OUTPUT WHICH IS SLIGHTLY FURTHER
SOUTH WITH THE BOUNDARY OVERNIGHT. THIS BRINGS MORE OF A
NORTHEASTERLY WIND ACROSS THE TULSA METRO...WHICH WILL IMPACT THE
PLACEMENT OF THE URBAN HEAT ISLAND PLUME AND CORRESPONDING
ADJUSTMENTS WERE MADE WHICH LOWERED KTUL AND RAISED KRVS VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 82 110 86 108 / 10 20 10 20
FSM 78 105 79 102 / 10 20 10 20
MLC 78 107 81 105 / 10 10 10 10
BVO 74 108 76 108 / 20 20 20 30
FYV 75 104 77 100 / 20 20 10 20
BYV 74 101 76 101 / 30 30 20 20
MKO 79 109 80 107 / 10 20 10 20
MIO 76 104 79 104 / 20 20 20 30
F10 79 112 79 107 / 10 10 10 10
HHW 78 104 78 99 / 10 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055-
OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-
OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010-
ARZ019-ARZ029.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020.
&&
$$
SHORT TERM...07
AREA FORECAST DISCUSSION
NWS TULSA OK
607 PM CDT THU AUG 2 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES
THROUGH THE ENTIRE 24 HOUR FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT THU AUG 2 2012/
DISCUSSION...
ANOTHER OUTFLOW BOUNDARY STRIKES AGAIN. CONVECTION OVER KANSAS
ONCE AGAIN SENT AN OUTFLOW BOUNDARY DOWN INTO OKLAHOMA EARLY THIS
MORNING...AND IT HAS HAD SOME AFFECT ON TEMPS TODAY. BECAUSE OF
THIS...IT DOES NOT APPEAR THAT THE ALL-TIME TEMP RECORD WILL BE
REACHED AT TULSA. THE LATEST RUNS OF THE HRRR SUGGEST SOME
ISOLATED TO WIDELY SCATTERED STORMS COULD DEVELOP ALONG THE EAST-
WEST ORIENTED LOW LVL TROUGH/CONVERGENT ZONE LATE THIS AFTERNOON
AND THIS EVENING. OTHER ELEVATED STORMS COULD DEVELOP ON THE EDGE
OF THE CAP LATE TONIGHT TO OUR EAST.
NAM MODEL 850MB DATA SUGGESTS THAT FRIDAY WILL BE ANOTHER
SCORCHER...WITH HIGHS NEAR 110...ALTHOUGH CONVECTIVE OUTFLOW COULD
AFFECT THIS LIKE IT HAS THE PAST COUPLE OF DAYS. SATURDAY IS
SHAPING UP TO BE HOTTER DUE TO SOME COMPRESSIONAL WARMING AHEAD OF
AN APPROACHING FRONT. SW WINDS WILL BE STRONGER AS WELL...AND THIS
WILL REALLY INCREASE FIRE WEATHER CONCERNS. THE HEAT HEADLINES
WILL CONTINUE ON THROUGH FRIDAY...HOWEVER THIS MAY NEED TO BE
EXTENDED INTO SATURDAY IN LATER FORECASTS. STORMS THAT FORM ALONG
THE FRONT IN KANSAS SATURDAY MAY MAKE THEIR WAY DOWN INTO OKLAHOMA
AND ARKANSAS LATE SATURDAY AND SATURDAY NIGHT. MUCH
COOLER...RELATIVELY SPEAKING...850MB TEMPS...MORE CLOUDS...AND
HIGHER HUMIDITY WILL YIELD HIGHS BELOW 100 DEGREES ON SUNDAY.
TEMPS WARM BACK UP NEXT WEEK INTO THE 100S...HOWEVER IT DOES APPEAR
THAT THE REBUILDING RIDGE AND RESULTING HEAT WILL NOT BE AS
INTENSE THIS GO AROUND. THERE MAY BE ANOTHER WEAK BOUNDARY BY NEXT
THURSDAY OR SO...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INSERT POPS
JUST YET.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055-
OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-
OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010-
ARZ019-ARZ029.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
430 PM EDT WED AUG 1 2012
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION
TONIGHT...THEN WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY
THROUGH SATURDAY. THE HIGH PRESSURE WILL START TO BREAK DOWN FROM
THE NORTHWEST ON SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE
REGION MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
2030 UTC UPDATE...SKY COVER WAS UPDATED FROM THE VISIBLE SATELLITE
IMAGERY. POPS WERE ADJUSTED PER RADAR TRENDS...ACCOUNTING FOR
ONGOING ISOLATED CONVECTION...AND THE MOVEMENT OF MORE WIDESPREAD
CELLS IN EAST TN APPROACHING THE SW NC MOUNTAINS.
AS OF 220 PM EDT...THE RAP CURRENTLY SHOWS A WEAK H5 SHORT WAVE OVER
THE NC MTNS. A STRONGER WAVE IS UPSTREAM OF THE REGION OVER NRN
KY. AN ENHANCED CU FIELD IS BEGINNING TO DEVELOP OVER NRN TN...SE KY
AND SW VA AHEAD OF THIS SHORT WAVE. THE 0-6KM EFFECTIVE SHEAR IS ON
THE ORDER OF 30 KTS WITH THIS FEATURE...AND I/D EXPECT THAT
CONVECTION WILL MAKE IT INTO THE MTNS BY EARLY EVENING. MORE
ISOLATED CONVECTION MAY ALSO DEVELOP OVER THE NEXT COUPLE HOURS
ACROSS THE HIGH TERRAIN...BUT THE MORE ORGANIZED CONVECTIVE ACTIVITY
SHOULD BEGIN TO AFFECT THE WRN CAROLINAS AROUND 6 PM. CONFIDENCE IN
AN ORGANIZED MCS AFFECTING A LARGE AREA ISN/T THAT HIGH...THOUGH
IT/S NOT OUT OF THE QUESTION. HOWEVER...BEEFIER HIGH CHANCE POPS
SEEM REASONABLE OVER THE MOUNTAINS...AND STORMS COULD LAST A WAYS
INTO THE OVERNIGHT PERIOD OVER THE FOOTHILLS AND PIEDMONT AS WELL. A
FEW OF THE STORMS WILL PRODUCE DAMAGING WINDS AS THE DCAPE VALUES
RANGE FROM 1000-1200 ACROSS THE REGION. THIS WILL BE ADDED TO THE
HWO.
H5 HEIGHTS RISE A LITTLE TOMORROW AS THE SRN PLAINS RIDGE WILL
BRIEFLY PUSH TO THE EAST. HOWEVER...A WEAK SFC FRONT WILL SET UP
OVER THE FOOTHILLS. THE NAM GENERATES GOOD CONVERGENCE OVER THE
FOOTHILLS AND PIEDMONT IN THE AFTN. THE MASS AND MOISTURE
CONVERGENCE RESULTS IS CONSIDERABLE CONVECTIVE COVERAGE ON THAT
MODEL EAST OF THE MTNS LATE IN THE DAY. EVEN THE SREF IS SHOWING
SOME FAIRLY HIGH 3-HLY POPS. THEREFORE I/VE RAISED POPS INTO THE LOW
CHANCE RANGE OVER PARTS OF THE I-85 URBAN CORRIDOR FOR TMRW. IT WILL
ALSO BE A HOT DAY WITH MANY FOOTHILL AND PIEDMONT LOCATIONS WARMING
INTO THE MID 90S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
AS OF 230 PM EDT WED...THE OVERALL PATTERN THROUGH THE SHORT RANGE
CONTINUES TO SHOW A WEAKNESS ALONG THE EAST COAST BETWEEN TWO RIDGES
TO OUR EAST AND WEST. EXPECT ISOLATED CONVECTION TO DIMINISH
THURSDAY EVENING WITH THE LOSS OF HEATING. FRIDAY LOOKS MORE
FAVORABLE FOR A LARGER NUMBER OF STORMS. THE MODELS SHOW SOME SORT
OF SHORT WAVE MOVING ACROSS THE TN VALLEY AND CUMBERLAND PLATEAU IN
THE AFTERNOON...WHICH SHOULD HELP TO ORGANIZE STORMS OVER THE MTNS.
ONCE FORMED...THE STORMS SHOULD SPREAD OUT ACROSS THE FOOTHILLS AND
PIEDMONT LATE IN THE DAY IN THE USUAL MANNER. TEMPS WERE NUDGED
TOWARD A GUIDANCE BLEND...WHICH WAS A FEW DEGREES COOLER THAN THE
PREVIOUS FCST. THE WAVE DAMPENS OUT ON SATURDAY BUT MOISTURE IS
DEEPER WITH A MORE SW FLOW AT LOW LEVELS. WE SHOULD SEE AN INCREASE
IN UPPER DIVERGENCE LATE IN THE DAY. THIS SHOULD LEAD TO COVERAGE A
BIT BETTER YET THAN FRIDAY...SO POP WAS RAISED WELL INTO THE CHANCE
RANGE. TEMPS WERE KEPT NEAR THE OLD FCST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WED...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A DEEP MOIST SW FLOW REMAINS IN PLACE OVER THE REGION
THROUGH THE WEEKEND AS WEAK RIDGE OF HIGH PRESSURE PERSISTS OVER THE
SOUTHEASTERN STATES. THE HEIGHTS WILL GRADUALLY FALL SUN INTO MON AS
A STRONG NORTHERN STREAM UPPER LOW PRESSURE MOVES THROUGH THE GREAT
LAKES REGION. A COLD FRONT WILL APPROACH FROM THE NW ON LATE SUNDAY
AND LIKELY STALL IN OR JUST NORTH OF THE AREA THROUGH WEDNESDAY.
HAVE MENTIONED HEALTHY DIURNAL SCATTERED POPS EACH AFTN/EVENING AS
MODEL SOUNDINGS SHOW HIGH PW VALUES (OVER 2 INCHES) AND MODERATE
INSTABILITY ACROSS OUR CWA. TEMPERATURES WILL REMAIN NEAR...OR A
COUPLE DEGREES BELOW SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...SCT CU SHOULD RISE TO AROUND 5 KFT LATER IN THE AFTN. A
WEAK UPPER LOW MAY BRING SOME SHRA/TSTMS TO THE VICINITY IN SEVERAL
HOURS TIME...PROBABLY INTO THE EVENING HOURS. CONFIDENCE ISN/T HIGH
ENOUGH TO ADD A TEMPO GROUP YET...BUT VCSH HAS BEEN ADDED STARTING
IN THE EARLY EVENING. NOT EXPECTING ANY CIG OR VSBY PROBLEMS
OVERNIGHT UNLESS A SHRA HAPPENS TO AFFECT THE AIRFIELD. THE WINDS
SHOULD REMAIN LIGHT OUT OF THE W TO NW THIS AFTN...THOUGH THEY WILL
BE VARIABLE. A MORE S TO SW COMPONENT TO THE FLOW IS EXPECTED
TONIGHT AND THU MORNING.
ELSEWHERE...A WEAK UPPER LOW WILL CROSS THE REGION THIS EVENING.
THIS MAY GIVE RISE TO SCT SHRA/TSTM ACTIVITY STARTING IN THE LATE
AFTN OR EARLY EVENING ACROSS THE FOOTHILLS AND PIEDMONT. STORMS WILL
GO A LITTLE EARLIER AT KAVL. HOWEVER...CONFIDENCE ISN/T HIGH ENOUGH
TO ADD TEMPO/S ANYWHERE YET. WINDS WILL BE LIGHT NW OVER THE NC
ZONES AND OUT OF THE W TO WSW OVER THE UPSTATE. WINDS ACROSS THE
REGION WILL TURN A LITTLE MORE SOUTHERLY TONIGHT. WITH A DAY OF
DRYING UNDER OUR BELTS...LOW CLOUDS AND FOG SHOULD BE FAR LESS
WIDESPREAD TONIGHT. HOWEVER...THE FRENCH BROAD VALLEY SHOULD SEE A
GOOD AMOUNT OF FOG AND LIFR CONDITIONS HAVE BEEN ADDED TO KAVL A
LITTLE LATER THAN THEY DEVELOPED LAST NIGHT.
OUTLOOK...SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL
SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT/MCAVOY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
339 PM EDT WED AUG 1 2012
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION
TONIGHT...THEN WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY
THROUGH SATURDAY. THE HIGH PRESSURE WILL START TO BREAK DOWN FROM
THE NORTHWEST ON SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE
REGION MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
1935 UTC UPDATE...SKY COVER WAS UPDATED FROM THE LATEST VISIBLE
SATELLITE IMAGERY...AND POPS ADJUSTED ACCORDINGLY. POPS WERE REDUCED
FOR THE NEXT FEW HOURS ACROSS MUCH OF THE AREA...ESPECIALLY EAST OF
THE MOUNTAINS...BUT WERE RAISED IN A FEW AREAS WHERE SHOWERS WERE
ALREADY FORMING.
AS OF 220 PM EDT...THE RAP CURRENTLY SHOWS A WEAK H5 SHORT WAVE OVER
THE NC MTNS. A STRONGER WAVE IS UPSTREAM OF THE REGION OVER NRN
KY. AN ENHANCED CU FIELD IS BEGINNING TO DEVELOP OVER NRN TN...SE KY
AND SW VA AHEAD OF THIS SHORT WAVE. THE 0-6KM EFFECTIVE SHEAR IS ON
THE ORDER OF 30 KTS WITH THIS FEATURE...AND I/D EXPECT THAT
CONVECTION WILL MAKE IT INTO THE MTNS BY EARLY EVENING. MORE
ISOLATED CONVECTION MAY ALSO DEVELOP OVER THE NEXT COUPLE HOURS
ACROSS THE HIGH TERRAIN...BUT THE MORE ORGANIZED CONVECTIVE ACTIVITY
SHOULD BEGIN TO AFFECT THE WRN CAROLINAS AROUND 6 PM. CONFIDENCE IN
AN ORGANIZED MCS AFFECTING A LARGE AREA ISN/T THAT HIGH...THOUGH
IT/S NOT OUT OF THE QUESTION. HOWEVER...BEEFIER HIGH CHANCE POPS
SEEM REASONABLE OVER THE MOUNTAINS...AND STORMS COULD LAST A WAYS
INTO THE OVERNIGHT PERIOD OVER THE FOOTHILLS AND PIEDMONT AS WELL. A
FEW OF THE STORMS WILL PRODUCE DAMAGING WINDS AS THE DCAPE VALUES
RANGE FROM 1000-1200 ACROSS THE REGION. THIS WILL BE ADDED TO THE
HWO.
H5 HEIGHTS RISE A LITTLE TOMORROW AS THE SRN PLAINS RIDGE WILL
BRIEFLY PUSH TO THE EAST. HOWEVER...A WEAK SFC FRONT WILL SET UP
OVER THE FOOTHILLS. THE NAM GENERATES GOOD CONVERGENCE OVER THE
FOOTHILLS AND PIEDMONT IN THE AFTN. THE MASS AND MOISTURE
CONVERGENCE RESULTS IS CONSIDERABLE CONVECTIVE COVERAGE ON THAT
MODEL EAST OF THE MTNS LATE IN THE DAY. EVEN THE SREF IS SHOWING
SOME FAIRLY HIGH 3-HLY POPS. THEREFORE I/VE RAISED POPS INTO THE LOW
CHANCE RANGE OVER PARTS OF THE I-85 URBAN CORRIDOR FOR TMRW. IT WILL
ALSO BE A HOT DAY WITH MANY FOOTHILL AND PIEDMONT LOCATIONS WARMING
INTO THE MID 90S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
AS OF 230 PM EDT WED...THE OVERALL PATTERN THROUGH THE SHORT RANGE
CONTINUES TO SHOW A WEAKNESS ALONG THE EAST COAST BETWEEN TWO RIDGES
TO OUR EAST AND WEST. EXPECT ISOLATED CONVECTION TO DIMINISH
THURSDAY EVENING WITH THE LOSS OF HEATING. FRIDAY LOOKS MORE
FAVORABLE FOR A LARGER NUMBER OF STORMS. THE MODELS SHOW SOME SORT
OF SHORT WAVE MOVING ACROSS THE TN VALLEY AND CUMBERLAND PLATEAU IN
THE AFTERNOON...WHICH SHOULD HELP TO ORGANIZE STORMS OVER THE MTNS.
ONCE FORMED...THE STORMS SHOULD SPREAD OUT ACROSS THE FOOTHILLS AND
PIEDMONT LATE IN THE DAY IN THE USUAL MANNER. TEMPS WERE NUDGED
TOWARD A GUIDANCE BLEND...WHICH WAS A FEW DEGREES COOLER THAN THE
PREVIOUS FCST. THE WAVE DAMPENS OUT ON SATURDAY BUT MOISTURE IS
DEEPER WITH A MORE SW FLOW AT LOW LEVELS. WE SHOULD SEE AN INCREASE
IN UPPER DIVERGENCE LATE IN THE DAY. THIS SHOULD LEAD TO COVERAGE A
BIT BETTER YET THAN FRIDAY...SO POP WAS RAISED WELL INTO THE CHANCE
RANGE. TEMPS WERE KEPT NEAR THE OLD FCST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WED...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A DEEP MOIST SW FLOW REMAINS IN PLACE OVER THE REGION
THROUGH THE WEEKEND AS WEAK RIDGE OF HIGH PRESSURE PERSISTS OVER THE
SOUTHEASTERN STATES. THE HEIGHTS WILL GRADUALLY FALL SUN INTO MON AS
A STRONG NORTHERN STREAM UPPER LOW PRESSURE MOVES THROUGH THE GREAT
LAKES REGION. A COLD FRONT WILL APPROACH FROM THE NW ON LATE SUNDAY
AND LIKELY STALL IN OR JUST NORTH OF THE AREA THROUGH WEDNESDAY.
HAVE MENTIONED HEALTHY DIURNAL SCATTERED POPS EACH AFTN/EVENING AS
MODEL SOUNDINGS SHOW HIGH PW VALUES (OVER 2 INCHES) AND MODERATE
INSTABILITY ACROSS OUR CWA. TEMPERATURES WILL REMAIN NEAR...OR A
COUPLE DEGREES BELOW SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...SCT CU SHOULD RISE TO AROUND 5 KFT LATER IN THE AFTN. A
WEAK UPPER LOW MAY BRING SOME SHRA/TSTMS TO THE VICINITY IN SEVERAL
HOURS TIME...PROBABLY INTO THE EVENING HOURS. CONFIDENCE ISN/T HIGH
ENOUGH TO ADD A TEMPO GROUP YET...BUT VCSH HAS BEEN ADDED STARTING
IN THE EARLY EVENING. NOT EXPECTING ANY CIG OR VSBY PROBLEMS
OVERNIGHT UNLESS A SHRA HAPPENS TO AFFECT THE AIRFIELD. THE WINDS
SHOULD REMAIN LIGHT OUT OF THE W TO NW THIS AFTN...THOUGH THEY WILL
BE VARIABLE. A MORE S TO SW COMPONENT TO THE FLOW IS EXPECTED
TONIGHT AND THU MORNING.
ELSEWHERE...A WEAK UPPER LOW WILL CROSS THE REGION THIS EVENING.
THIS MAY GIVE RISE TO SCT SHRA/TSTM ACTIVITY STARTING IN THE LATE
AFTN OR EARLY EVENING ACROSS THE FOOTHILLS AND PIEDMONT. STORMS WILL
GO A LITTLE EARLIER AT KAVL. HOWEVER...CONFIDENCE ISN/T HIGH ENOUGH
TO ADD TEMPO/S ANYWHERE YET. WINDS WILL BE LIGHT NW OVER THE NC
ZONES AND OUT OF THE W TO WSW OVER THE UPSTATE. WINDS ACROSS THE
REGION WILL TURN A LITTLE MORE SOUTHERLY TONIGHT. WITH A DAY OF
DRYING UNDER OUR BELTS...LOW CLOUDS AND FOG SHOULD BE FAR LESS
WIDESPREAD TONIGHT. HOWEVER...THE FRENCH BROAD VALLEY SHOULD SEE A
GOOD AMOUNT OF FOG AND LIFR CONDITIONS HAVE BEEN ADDED TO KAVL A
LITTLE LATER THAN THEY DEVELOPED LAST NIGHT.
OUTLOOK...SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL
SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT/MCAVOY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
250 PM EDT WED AUG 1 2012
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION
TONIGHT...THEN WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY
THROUGH SATURDAY. THE HIGH PRESSURE WILL START TO BREAK DOWN FROM
THE NORTHWEST ON SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE
REGION MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 220 PM EDT...THE RAP CURRENTLY SHOWS A WEAK H5 SHORT WAVE OVER
THE NC MTNS. A STRONGER WAVE IS UPSTREAM OF THE REGION OVER NRN
KY. AN ENHANCED CU FIELD IS BEGINNING TO DEVELOP OVER NRN TN...SE KY
AND SW VA AHEAD OF THIS SHORT WAVE. THE 0-6KM EFFECTIVE SHEAR IS ON
THE ORDER OF 30 KTS WITH THIS FEATURE...AND I/D EXPECT THAT
CONVECTION WILL MAKE IT INTO THE MTNS BY EARLY EVENING. MORE
ISOLATED CONVECTION MAY ALSO DEVELOP OVER THE NEXT COUPLE HOURS
ACROSS THE HIGH TERRAIN...BUT THE MORE ORGANIZED CONVECTIVE ACTIVITY
SHOULD BEGIN TO AFFECT THE WRN CAROLINAS AROUND 6 PM. CONFIDENCE IN
AN ORGANIZED MCS AFFECTING A LARGE AREA ISN/T THAT HIGH...THOUGH
IT/S NOT OUT OF THE QUESTION. HOWEVER...BEEFIER HIGH CHANCE POPS
SEEM REASONABLE OVER THE MOUNTAINS...AND STORMS COULD LAST A WAYS
INTO THE OVERNIGHT PERIOD OVER THE FOOTHILLS AND PIEDMONT AS WELL. A
FEW OF THE STORMS WILL PRODUCE DAMAGING WINDS AS THE DCAPE VALUES
RANGE FROM 1000-1200 ACROSS THE REGION. THIS WILL BE ADDED TO THE
HWO.
H5 HEIGHTS RISE A LITTLE TOMORROW AS THE SRN PLAINS RIDGE WILL
BRIEFLY PUSH TO THE EAST. HOWEVER...A WEAK SFC FRONT WILL SET UP
OVER THE FOOTHILLS. THE NAM GENERATES GOOD CONVERGENCE OVER THE
FOOTHILLS AND PIEDMONT IN THE AFTN. THE MASS AND MOISTURE
CONVERGENCE RESULTS IS CONSIDERABLE CONVECTIVE COVERAGE ON THAT
MODEL EAST OF THE MTNS LATE IN THE DAY. EVEN THE SREF IS SHOWING
SOME FAIRLY HIGH 3-HLY POPS. THEREFORE I/VE RAISED POPS INTO THE LOW
CHANCE RANGE OVER PARTS OF THE I-85 URBAN CORRIDOR FOR TMRW. IT WILL
ALSO BE A HOT DAY WITH MANY FOOTHILL AND PIEDMONT LOCATIONS WARMING
INTO THE MID 90S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
AS OF 230 PM EDT WED...THE OVERALL PATTERN THROUGH THE SHORT RANGE
CONTINUES TO SHOW A WEAKNESS ALONG THE EAST COAST BETWEEN TWO RIDGES
TO OUR EAST AND WEST. EXPECT ISOLATED CONVECTION TO DIMINISH
THURSDAY EVENING WITH THE LOSS OF HEATING. FRIDAY LOOKS MORE
FAVORABLE FOR A LARGER NUMBER OF STORMS. THE MODELS SHOW SOME SORT
OF SHORT WAVE MOVING ACROSS THE TN VALLEY AND CUMBERLAND PLATEAU IN
THE AFTERNOON...WHICH SHOULD HELP TO ORGANIZE STORMS OVER THE MTNS.
ONCE FORMED...THE STORMS SHOULD SPREAD OUT ACROSS THE FOOTHILLS AND
PIEDMONT LATE IN THE DAY IN THE USUAL MANNER. TEMPS WERE NUDGED
TOWARD A GUIDANCE BLEND...WHICH WAS A FEW DEGREES COOLER THAN THE
PREVIOUS FCST. THE WAVE DAMPENS OUT ON SATURDAY BUT MOISTURE IS
DEEPER WITH A MORE SW FLOW AT LOW LEVELS. WE SHOULD SEE AN INCREASE
IN UPPER DIVERGENCE LATE IN THE DAY. THIS SHOULD LEAD TO COVERAGE A
BIT BETTER YET THAN FRIDAY...SO POP WAS RAISED WELL INTO THE CHANCE
RANGE. TEMPS WERE KEPT NEAR THE OLD FCST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WED...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A DEEP MOIST SW FLOW REMAINS IN PLACE OVER THE REGION
THROUGH THE WEEKEND AS WEAK RIDGE OF HIGH PRESSURE PERSISTS OVER THE
SOUTHEASTERN STATES. THE HEIGHTS WILL GRADUALLY FALL SUN INTO MON AS
A STRONG NORTHERN STREAM UPPER LOW PRESSURE MOVES THROUGH THE GREAT
LAKES REGION. A COLD FRONT WILL APPROACH FROM THE NW ON LATE SUNDAY
AND LIKELY STALL IN OR JUST NORTH OF THE AREA THROUGH WEDNESDAY.
HAVE MENTIONED HEALTHY DIURNAL SCATTERED POPS EACH AFTN/EVENING AS
MODEL SOUNDINGS SHOW HIGH PW VALUES (OVER 2 INCHES) AND MODERATE
INSTABILITY ACROSS OUR CWA. TEMPERATURES WILL REMAIN NEAR...OR A
COUPLE DEGREES BELOW SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...SCT CU SHOULD RISE TO AROUND 5 KFT LATER IN THE AFTN. A
WEAK UPPER LOW MAY BRING SOME SHRA/TSTMS TO THE VICINITY IN SEVERAL
HOURS TIME...PROBABLY INTO THE EVENING HOURS. CONFIDENCE ISN/T HIGH
ENOUGH TO ADD A TEMPO GROUP YET...BUT VCSH HAS BEEN ADDED STARTING
IN THE EARLY EVENING. NOT EXPECTING ANY CIG OR VSBY PROBLEMS
OVERNIGHT UNLESS A SHRA HAPPENS TO AFFECT THE AIRFIELD. THE WINDS
SHOULD REMAIN LIGHT OUT OF THE W TO NW THIS AFTN...THOUGH THEY WILL
BE VARIABLE. A MORE S TO SW COMPONENT TO THE FLOW IS EXPECTED
TONIGHT AND THU MORNING.
ELSEWHERE...A WEAK UPPER LOW WILL CROSS THE REGION THIS EVENING.
THIS MAY GIVE RISE TO SCT SHRA/TSTM ACTIVITY STARTING IN THE LATE
AFTN OR EARLY EVENING ACROSS THE FOOTHILLS AND PIEDMONT. STORMS WILL
GO A LITTLE EARLIER AT KAVL. HOWEVER...CONFIDENCE ISN/T HIGH ENOUGH
TO ADD TEMPO/S ANYWHERE YET. WINDS WILL BE LIGHT NW OVER THE NC
ZONES AND OUT OF THE W TO WSW OVER THE UPSTATE. WINDS ACROSS THE
REGION WILL TURN A LITTLE MORE SOUTHERLY TONIGHT. WITH A DAY OF
DRYING UNDER OUR BELTS...LOW CLOUDS AND FOG SHOULD BE FAR LESS
WIDESPREAD TONIGHT. HOWEVER...THE FRENCH BROAD VALLEY SHOULD SEE A
GOOD AMOUNT OF FOG AND LIFR CONDITIONS HAVE BEEN ADDED TO KAVL A
LITTLE LATER THAN THEY DEVELOPED LAST NIGHT.
OUTLOOK...SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL
SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...MCAVOY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1047 PM CDT THU AUG 2 2012
.DISCUSSION.../ISSUED AT 942 PM CDT/
FOR THE MOST PART...FORECAST IS RUNNING ON TRACK THIS EVENING. HAD
A COUPLE OF ISOLATED SHOWERS BRUSH UP IN AREAS AROUND K9V9...BUT
ANYTHING SIGNIFICANT REMAINS WELL WEST SO FAR THIS EVENING WITH SOME
SEVERE STORMS WITH WIND OUT WHERE LOW LEVEL JET IS MORE SUPPORTIVE.
AIRMASS TOWARD THE EAST IS NO GIFT TO STORMS...SO ATTEMPT TO OUTRUN
THE VEERING LOW LEVEL JET MAY LEAD TO A QUICK WEAKENING OF SYSTEM
NEXT FEW HOURS. HRRR SEEMS TO BE FAR TOO OPTIMISTIC WITH SOUTHEAST
SPREAD TO CONVECTION...WITH INDICATION OF SOMEWHAT BETTER
CONVERGENCE FOCUSING MORE AND MORE NORTHWARD OVERNIGHT. AS LONG AS
FEATURE CAN REMAIN ELEVATED AND TIED TO LOWER TO MID LEVEL
ADVECTION...WILL BE ABLE TO MAINTAIN SOME DEGREE OF ORGANIZATION
WITH STEEP ELEVATED MIXED LAYER. THEREFORE...DO ACKNOWLEDGE MORE OF
A RIGHT TURN AND EASTWARD SPREAD WITH SOME SLIGHTLY HIGHER POPS
THROUGH THE MISSOURI RIVER CORRIDOR.
DID INCREASE WINDS SOMEWHAT LATER TONIGHT AND EARLY TOMORROW IN THE
WEST...BUT COULD ALSO BE DEALING WITH AN OUTFLOW POOL WHICH MAY
DISRUPT THE STRENGTHENING SYNOPTIC GRADIENT. A FEW ADJUSTMENTS TO
HOURLY TRENDS...AND WILL KNOCK A COUPLE DEGREES OFF THE FAR WEST TO
ACCOUNT FOR COOLER OUTFLOW. /CHAPMAN
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
SCATTERED HIGH BASED THUNDERSTORMS IN WESTERN SOUTH DAKOTA COULD
PUSH INTO THE FAR WESTERN FORECAST AREA FROM 06Z THROUGH 10Z AND
WILL LIKELY DISSIPATE AS THEY MOVE EASTWARD INTO THE JAMES RIVER
VALLEY. VFR CONDITIONS SHOULD PREVAIL OVERNIGHT. SCATTERED
THUNDERSTORMS ARE EXPECTED TO REDEVELOP AHEAD OF A COLD FRONT IN
SOUTH CENTRAL SOUTH DAKOTA LATE FRIDAY MORNING INTO THE AFTERNOON
HOURS AND WILL SPREAD EASTWARD THROUGH 06Z/SATURDAY. WINDS ARE ALSO
EXPECTED TO BECOME BREEZY FROM THE SOUTH SOUTHEAST AHEAD OF THE
FRONT BY LATE MORNING AND WILL BEGIN SHIFTING NORTH NORTHWEST BEHIND
THE FRONT LATE IN THE TAF PERIOD.
&&
.PREV DISCUSSION.../ISSUED AT 250 PM CDT/
FAIRLY TRANQUIL EVENING ACROSS THE AREA EXPECTED WITH LIGHT
NORTHEAST FLOW TAKING ON MORE OF A TRUE EASTERLY COMPONENT
OVERNIGHT. STORMS ACROSS WESTERN PORTIONS OF THE STATE WILL SHIFT
EAST...POSSIBLY WORKING INTO THE WESTERN CWA AFTER MIDNIGHT. AXIS
OF WARM AIR ADVECTION ALOFT REMAINS WEST OF CWA THROUGH 12Z...AND
WEST OF I-29 THROUGH 18Z. COULD SEE SOME ELEVATED STORMS FRIDAY
MORNING IN THE WEST...BUT ANY ACTIVITY WILL BE FIGHTING LOW LEVEL
DRY AIR.
MODELS TRENDING SLOWER WITH THE FRONTAL PASSAGE ON FRIDAY. QUESTION
AS TO HOW MUCH CLOUD COVER WILL HAMPER HEATING...BUT GIVEN WE HAVE
BEEN ABLE TO HEAT OUT FAIRLY WELL NEAR FRONTAL PASSAGES AS OF LATE
SIDED MUCH CLOSER TO WARMER MET GUIDANCE AS OPPOSED TO THE MUCH
COOLER MAV. UPPER WAVE DRIVING THE FRONT REMAINS MAINLY ACROSS NORTH
DAKOTA INTO EXTREME SOUTH DAKOTA...SO BEST CHANCES FOR PRECIPITATION
APPEAR TO BE ACROSS THE NORTHERN HALF OF THE FORECAST AREA. ANY
SURFACE BASED STORMS THAT DEVELOP WILL HAVE A STRONG WIND
COMPONENT...WITH AN OUTSIDE THREAT OF LARGE HAIL.
FOCUS FOR FRIDAY NIGHT WILL BE ON CONVECTION ALONG AND AHEAD OF COLD
FRONT. EXPECT AT LEAST A SCATTERED LINE OF THUNDERSTORMS TO REACH
I29 AROUND 00Z OR SLIGHTLY AFTER DEPENDING ON EXACT LOCATION OF
AFTERNOON DEVELOPMENT ACROSS THE WEST. AS THE LINE DEVELOPS WOULD
EXPECT IT TO ACCELERATE IT EASTWARD PROGRESSION AS UPPER LOW PUSHES
INTO ND DURING THE EVENING. MAIN THREAT WITH THE STORMS SHOULD BE
WIND AS THEY MOVE EAST DURING THE EVENING HOURS WITH A FEW DISCRETE
STORMS PRODUCING LARGER HAIL. AS FRONT BECOMES MORE PARALLEL TO
UPPER FLOW ACROSS FAR SOUTHEAST CWA LATER IN THE NIGHT...MAY SEE
REDEVELOPMENT THROUGH THE NIGHT AFTER 06Z ALONG AND NORTH OF FRONT
MAINLY SOUTH OF I90...AND PERSIST INTO EARLY SATURDAY MORNING. SO
WILL NEED TO KEEP STORMS CHANCES IN FORECAST THROUGH THE NIGHT WITH
BEST CHANCE ACROSS NORTHERN CWA THROUGH 06Z AND ACROSS PORTIONS OF
NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA AFTER INITIAL SURGE OF
STORMS.
SHOULD BE BREEZY AND COOLER ACROSS THE CWA ON SATURDAY WITH SPOTTY
STORMS POSSIBLY REDEVELOPING ACROSS SOUTHWEST MINNESOTA IN THE
AFTERNOON WITH CYCLONIC FLOW ALOFT.
THE PLEASANT WEATHER WILL CONTINUE ON SUNDAY ACROSS THE CWA WITH
MORE SUN AND LIGHTER WINDS EXPECTED.
MONDAY THROUGH THURSDAY WILL SEE ABOVE NORMAL TEMPERATURES...BUT NOT
AS HOT AS BEFORE AS RIDGE ALOFT WILL NOT BE QUITE AS STRONG WITH
HOTTEST AIR BEING SHUNTED OFF TO THE WEST AND SOUTH.
WILL BE SMALL CHANCES FOR STORMS AS WEAK WAVES RIDE OVER RIDGE. FOR
NOW WILL KEEP SMALL CHANCES FOR TUESDAY NIGHT INTO WEDNESDAY...BUT
COULD SEE AN ISOLATED STORMS MONDAY AFTERNOON/EVENING OVER SOUTHEAST
CWA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
942 PM CDT THU AUG 2 2012
.DISCUSSION.../ISSUED AT 942 PM CDT/
FOR THE MOST PART...FORECAST IS RUNNING ON TRACK THIS EVENING. HAD
A COUPLE OF ISOLATED SHOWERS BRUSH UP IN AREAS AROUND K9V9...BUT
ANYTHING SIGNIFICANT REMAINS WELL WEST SO FAR THIS EVENING WITH SOME
SEVERE STORMS WITH WIND OUT WHERE LOW LEVEL JET IS MORE SUPPORTIVE.
AIRMASS TOWARD THE EAST IS NO GIFT TO STORMS...SO ATTEMPT TO OUTRUN
THE VEERING LOW LEVEL JET MAY LEAD TO A QUICK WEAKENING OF SYSTEM
NEXT FEW HOURS. HRRR SEEMS TO BE FAR TOO OPTIMISTIC WITH SOUTHEAST
SPREAD TO CONVECTION...WITH INDICATION OF SOMEWHAT BETTER
CONVERGENCE FOCUSING MORE AND MORE NORTHWARD OVERNIGHT. AS LONG AS
FEATURE CAN REMAIN ELEVATED AND TIED TO LOWER TO MID LEVEL
ADVECTIONS...WILL BE ABLE TO MAINTAIN SOME DEGREE OF ORGANIZATION
WITH STEEP ELEVATED MIXED LAYER. THEREFORE...DO ACKNOWLEDGE MORE OF
A RIGHT TURN AND EASTWARD SPREAD WITH SOME SLIGHTLY HIGHER POPS
THROUGH THE MISSOURI RIVER CORRIDOR.
DID INCREASE WINDS SOMEWHAT LATER TONIGHT AND EARLY TOMORROW IN THE
WEST...BUT COULD ALSO BE DEALING WITH AN OUTFLOW POOL WHICH MAY
DISRUPT THE STRENGTHENING SYNOPTIC GRADIENT. A FEW ADJUSTMENTS TO
HOURLY TRENDS...AND WILL KNOCK A COUPLE DEGREES OFF THE FAR WEST TO
ACCOUNT FOR COOLER OUTFLOW. /CHAPMAN
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
SCATTERED HIGH BASED THUNDERSTORMS IN WESTERN SOUTH DAKOTA COULD
PUSH INTO THE FAR WESTERN FORECAST AREA FROM 06Z THROUGH 12Z AND
WILL LIKELY DISSIPATE AS THEY MOVE EASTWARD INTO THE JAMES RIVER
VALLEY. VFR CONDITIONS SHOULD PREVAIL OVERNIGHT...INCLUDING IN
THUNDERSTORM ACTIVITY. SCATTERED THUNDERSTORMS ARE EXPECTED TO
REDEVELOP AHEAD OF A COLD FRONT IN SOUTH CENTRAL SOUTH DAKOTA LATE
FRIDAY MORNING INTO THE AFTERNOON HOURS. WINDS ARE ALSO EXPECTED TO
BECOME BREEZY FROM THE SOUTH SOUTHEAST AHEAD OF THE FRONT BY LATE
MORNING.
&&
.PREV DISCUSSION.../ISSUED AT 250 PM CDT/
FAIRLY TRANQUIL EVENING ACROSS THE AREA EXPECTED WITH LIGHT
NORTHEAST FLOW TAKING ON MORE OF A TRUE EASTERLY COMPONENT
OVERNIGHT. STORMS ACROSS WESTERN PORTIONS OF THE STATE WILL SHIFT
EAST...POSSIBLY WORKING INTO THE WESTERN CWA AFTER MIDNIGHT. AXIS
OF WARM AIR ADVECTION ALOFT REMAINS WEST OF CWA THROUGH 12Z...AND
WEST OF I-29 THROUGH 18Z. COULD SEE SOME ELEVATED STORMS FRIDAY
MORNING IN THE WEST...BUT ANY ACTIVITY WILL BE FIGHTING LOW LEVEL
DRY AIR.
MODELS TRENDING SLOWER WITH THE FRONTAL PASSAGE ON FRIDAY. QUESTION
AS TO HOW MUCH CLOUD COVER WILL HAMPER HEATING...BUT GIVEN WE HAVE
BEEN ABLE TO HEAT OUT FAIRLY WELL NEAR FRONTAL PASSAGES AS OF LATE
SIDED MUCH CLOSER TO WARMER MET GUIDANCE AS OPPOSED TO THE MUCH
COOLER MAV. UPPER WAVE DRIVING THE FRONT REMAINS MAINLY ACROSS NORTH
DAKOTA INTO EXTREME SOUTH DAKOTA...SO BEST CHANCES FOR PRECIPITATION
APPEAR TO BE ACROSS THE NORTHERN HALF OF THE FORECAST AREA. ANY
SURFACE BASED STORMS THAT DEVELOP WILL HAVE A STRONG WIND
COMPONENT...WITH AN OUTSIDE THREAT OF LARGE HAIL.
FOCUS FOR FRIDAY NIGHT WILL BE ON CONVECTION ALONG AND AHEAD OF COLD
FRONT. EXPECT AT LEAST A SCATTERED LINE OF THUNDERSTORMS TO REACH
I29 AROUND 00Z OR SLIGHTLY AFTER DEPENDING ON EXACT LOCATION OF
AFTERNOON DEVELOPMENT ACROSS THE WEST. AS THE LINE DEVELOPS WOULD
EXPECT IT TO ACCELERATE IT EASTWARD PROGRESSION AS UPPER LOW PUSHES
INTO ND DURING THE EVENING. MAIN THREAT WITH THE STORMS SHOULD BE
WIND AS THEY MOVE EAST DURING THE EVENING HOURS WITH A FEW DISCRETE
STORMS PRODUCING LARGER HAIL. AS FRONT BECOMES MORE PARALLEL TO
UPPER FLOW ACROSS FAR SOUTHEAST CWA LATER IN THE NIGHT...MAY SEE
REDEVELOPMENT THROUGH THE NIGHT AFTER 06Z ALONG AND NORTH OF FRONT
MAINLY SOUTH OF I90...AND PERSIST INTO EARLY SATURDAY MORNING. SO
WILL NEED TO KEEP STORMS CHANCES IN FORECAST THROUGH THE NIGHT WITH
BEST CHANCE ACROSS NORTHERN CWA THROUGH 06Z AND ACROSS PORTIONS OF
NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA AFTER INITIAL SURGE OF
STORMS.
SHOULD BE BREEZY AND COOLER ACROSS THE CWA ON SATURDAY WITH SPOTTY
STORMS POSSIBLY REDEVELOPING ACROSS SOUTHWEST MINNESOTA IN THE
AFTERNOON WITH CYCLONIC FLOW ALOFT.
THE PLEASANT WEATHER WILL CONTINUE ON SUNDAY ACROSS THE CWA WITH
MORE SUN AND LIGHTER WINDS EXPECTED.
MONDAY THROUGH THURSDAY WILL SEE ABOVE NORMAL TEMPERATURES...BUT NOT
AS HOT AS BEFORE AS RIDGE ALOFT WILL NOT BE QUITE AS STRONG WITH
HOTTEST AIR BEING SHUNTED OFF TO THE WEST AND SOUTH.
WILL BE SMALL CHANCES FOR STORMS AS WEAK WAVES RIDE OVER RIDGE. FOR
NOW WILL KEEP SMALL CHANCES FOR TUESDAY NIGHT INTO WEDNESDAY...BUT
COULD SEE AN ISOLATED STORMS MONDAY AFTERNOON/EVENING OVER SOUTHEAST
CWA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
829 PM MDT THU AUG 2 2012
.UPDATE...ONE COUNTY REMAINING IN THE WATCH AT 8 PM BUT WE WILL BE
ABLE TO CANCEL THAT ONE WITHIN THE HOUR. THE SEVERE THUNDERSTORM
IN EASTERN PENNINGTON COUNTY WILL MOVE INTO A MORE STABLE AIRMASS
SHORTLY SO NOT SURE HOW MUCH LONGER IT CAN SUSTAIN THE STRONG
UPDRAFT THAT KEPT IT GOING FOR OVER 160 MILES. HRRR HAS HAD A GOOD
HANDLE ON THE LEADING EDGE OF THE SYSTEM ALL EVENING BUT KEEPS TOO
MUCH PRECIP ONGOING BEHIND THE MAIN BAND. A BROAD SURFACE LOW OVER
EASTERN WYOMING IS JUST STARTING TO SHIFT EASTWARD A BIT WITH
SURFACE PRESSURE RISES OF 1 TO 1.5 MB/3HR SHOWING UP IN THE OBS
OVER SOUTHEAST MONTANA AND NORTHEASTERN WYOMING THIS PAST HOUR.
&&
.PREV DISCUSSION... /ISSUED 500 PM MDT THU AUG 2 2012/
AVIATION...00Z TAFS
ISO-SCT TSRA WILL CONTINUE OVER FAR NERN WY AND NWRN/CNTRL SD INTO
THE EVENING HOURS. SOME STORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING
WIND GUSTS. LCL IFR VIS WILL BE POSSIBLE IN HEAVIER PRECIP....OTHERWISE
VFR CONDITIONS ARE EXPECTED. BREEZY NORTHERLY WINDS ARE EXPECTED WITH
FRONTAL PASSAGE ON FRIDAY MORNING.
PREV DISCUSSION... /ISSUED 234 PM MDT THU AUG 2 2012/
DISCUSSION...UPPER LEVEL ANALYSIS HAS RIDGING ACROSS THE SOUTHERN
AND SOUTHWESTERN PARTS OF THE UNITED STATES...WITH A WEAK
SHORTWAVE RIDGE CROSSING THE NORTHERN PLAINS. VIGOROUS UPPER LOW
IS CURRENTLY MOVING SOUTHEAST ALONG THE SPINE OF THE SOUTHERN
CANADIAN ROCKIES. SHORTWAVE TROF IS UNDERCUTTING THE RIDGING
ACROSS THE FORECAST AREA...PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS. A STRONG LINE OF STORMS HAVE DEVELOPED FROM NEAR
GILLETTE INTO SOUTHEAST MONTANA. 20Z SURFACE ANALYSIS HAS HIGH
PRESSURE OVER THE EASTERN DAKOTAS WITH LOW PRESSURE DEVELOPING
OVER NORTHEAST WYOMING AND SOUTHEAST MONTANA. TEMPERATURES ARE IN
THE 80S TO LOWER 90S WITH WINDS GENERALLY OUT OF THE SOUTH TO
SOUTHEAST AT 15 TO 25 MPH.
SURFACE LOW AND ASSOCIATED TROF OVER SOUTHEAST MONTANA AND
NORTHEAST WYOMING WILL SLOWLY PUSH EAST THIS AFTERNOON AND
EVENING...AND WILL BE FOCAL POINT FOR STRONG TO SEVERE CONVECTION.
BEST INSTABILITY AND SHEAR RESIDE MAINLY FROM THE BLACK HILLS INTO
NORTHWEST SOUTH DAKOTA...SO EXPECT STRONGEST STORMS TO CROSS THIS
AREA. TEMP/TD SPREADS ARE FAIRLY LARGE...SO MAIN STORM THREAT WILL
BE STRONG GUSTY WINDS...ALONG WITH SOME HAIL. SHOWERS AND STORMS
WILL SHIFT EAST OF THE FORECAST AREA BY LATE THIS EVENING.
FRIDAY...STRONG COLD FRONT WILL PUSH THROUGH OUR WESTERN ZONES IN
THE MORNING AND THROUGH OUR EASTERN ZONES BY EARLY AFTERNOON.
STRONG COLD ADVECTION AND PRESSURE RISES AROUND 3MB/3HR WILL SUPPORT
GUSTY NORTHWEST WINDS...ESPECIALLY ON THE PLAINS OF NORTHWESTERN SD.
CYCLONIC FLOW ALOFT...COMBINED WITH RESIDUAL INSTABILITY/MOISTURE
WILL LEAD TO CHANCES FOR SHOWERS/TSTMS ACROSS OUR CWFA. TEMPS WILL
BE WIDE RANGING...FROM THE 70S IN OUR WEST TO MID/UPPER 90S IN
SOUTH CENTRAL SD AHEAD OF THE COLD PUSH.
SATURDAY...DRY AND COOLER CONDITIONS EXPECTED...ALTHOUGH
BREEZY/WINDY CONDITIONS WILL PREVAIL WITH STRONG NW FLOW ALOFT
MIXING TOWARDS THE SURFACE DURING DAYTIME HEATING.
EXTENDED...RIDGE WILL REBUILD OVER THE WESTERN CONUS...BRINGING A
RETURN TO HOT AND DRY CONDITIONS EARLY IN THE WEEK. A VARIETY OF
WEAK DISTURBANCES WILL PUSH THRU THE RIDGE DURING THE MIDDLE PART OF
THE WEEK...BRINGING OCCASIONAL CHANCES FOR STORMS. ABOVE AVERAGE
TEMPERATURES WILL CONTINUE THROUGH THE PERIOD.
FIRE WEATHER...
KEPT RED FLAG WARNING FOR THE PLAINS OF NORTHEASTERN WYOMING AS DRY
THUNDERSTORMS MOVED ACROSS THE AREA THIS MORNING AND MORE STORMS ARE
FIRING AT THIS TIME. WINDS HAVE FREQUENTLY GUSTED ABOVE 35 MPH EVEN
THOUGH RH VALUES ARE STILL HOLDING AROUND 20 TO 25 PERCENT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR LOWER
ELEVATIONS OF CROOK AND WESTON COUNTIES-NORTHERN CAMPBELL-
SOUTHERN CAMPBELL.
&&
$$
SHORT TERM...CARPENTER
LONG TERM....WFO UNR
AVIATION...CARPENTER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1002 PM CDT THU AUG 2 2012
.UPDATE...TERMINAL FORECASTS
&&
.AVIATION...
COMPLEX THAT HAD BEEN HEADED THIS WAY HAS SHOWN A MORE EASTWARD
TREK TOWARD SOUTHWEST INDIANA/KENTUCKY. MODELS NOT HANDLING THIS
VERY WELL BUT NAM MAY HAVE THE BEST HANDLE AT THE MOMENT. CAP
CONTINUES TO HOLD OVER MIDDLE TENNESSEE BUT LATEST RUC FORECAST
HAS IT WEAKENING TOWARD 06Z WITH TEMPS < +12 CELSIUS AT 700
MILLIBARS BY 04Z ACROSS THE MID STATE. THIS SHOULD ALLOW FOR SOME
SOUTHWARD EXTENSION OF ACTIVITY DOWN INTO MIDDLE TENNESSEE AS WE
GO TOWARD MIDNIGHT AND THROUGH THE OVERNIGHT HOURS. I COMPLETELY
REWORKED TERMINAL FORECASTS FOR REMAINDER OF THE 24 HOUR PERIOD.
CONFIDENCE IS LOW ON ANY PARTICULAR TIMING FOR STORMS SO WENT WITH
VICINITY TSTMS.
BOYD
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT THU AUG 2 2012/
UPDATE...
FRONTAL BOUNDARY CONTINUES TO HANG JUST NORTH OF THE TN BORDER...
WITH MID-LEVELS ACROSS THE FCST AREA CAPPED AT THIS POINT. COMPLEX
IN WEST KY...SOUTH IL/IN WAS EXPECTED TO MOVE SOUTH BUT CURRENTLY
IS PUSHING MORE EAST...WITH SOUTHERN FLANK STRUGGLING TO DEVELOP.
CAP SLOWLY WEAKENS LATER THIS EVE BUT LATEST DATA SUGGESTING SCT
STORMS WILL AFFECT MAINLY THE NORTH AND ESPECIALLY ALONG THE KY
BORDER THRU 12Z...THEN BECOME MUCH MORE NUMEROUS ON FRIDAY. AT
THIS TIME WILL RUN WITH CHANCE POPS...LEANING HIGHER NORTH...AND
KEEP SOUTH GENERALLY UNCHANGED. MAY UPDATE AGAIN LATER SHOULD
COMPLEX MAKE STRONG TURN SOUTH.
PREV DISCUSSION... /ISSUED 754 PM CDT THU AUG 2 2012/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
GOOD CAP (+12 TO +13 DEGREES CELSIUS AT 700 MB) IN PLACE ACROSS
NORTHERN MIDDLE TENNESSEE THIS EVENING HAS KEPT CONVECTION FROM
DEVELOPING AROUND NASHVILLE. COMPLEX OVER SOUTHERN ILLINOIS HAS
BEEN HEADED SOUTHEAST BUT IN THE LAST COUPLE OF PICS IT HAS SHOWN
A LITTLE MORE EASTWARD COMPONENT. WILL HAVE TO KEEP TABS ON THIS
AS MODELS BRING IT DOWN INTO WESTERN KY DURING THE EVENING AND
INTO MIDDLE TN AROUND MIDNIGHT.
LOOK FOR SOME LATE NIGHT FOG AT CROSSVILLE.
BOYD
PREV DISCUSSION... /ISSUED 351 PM CDT THU AUG 2 2012/
DISCUSSION...
FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION
COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.
FORECAST QUANDARIES...IMPACTS OF POTENTIAL MCS TONIGHT AND ON FRI...
POTENTIAL FOR SHWRS/TSTMS THRU MID WEEK NEXT WEEK...TEMPS.
AS FOR TONIGHT...WILL BE WAITING CLOSE TO PRESS TIME PER REGIONAL
RADAR TRENDS FOR FINAL DECISION...BUT EXPECT MVV ACROSS NRN MO
PRESENTLY...ALONG WITH DEVELOPING EMBEDDED SHORTWAVE IN
PREDOMINATELY NWLY FLOW ALOFT...TO RESULTING IN EVENTUAL AN MCS
DEVELOPMENT EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING ACROSS
CNTRL AND SERN MO...EVENTUALLY MOVING SEWD INTO AT LEAST WRN
PORTIONS OF THE MID STATE DURING THE LATE EVENING HRS. MAY NEED TO
BREAK OUT A LATE AFTERNOON GROUPING IN THE ZONE FORECAST PRODUCT
TO EMPHASIZE ACTUAL TIMING IMPACTS. WILL CONTINUE TO GO WITH
REASONING CLOSE TO MORNING FORECAST PACKAGE WITH MOST LOCATIONS W
OF THE PLATEAU HAVING A CHANCE...TO EVEN LIKELY...SHWRS/TSTMS
TOWARD DAYBREAK. WILL GO CLOSE TO CONSENSUS MODEL GUIDANCE ON
LOWS...MAINLY IN THE MID 70S...BUT...WITH CLOUD COVERAGE POSSIBLY
NOT AS PRONOUNCED ACROSS THE PLATEAU AND ONLY A SLIGHT CHANCE OF
SHWRS/TSTMS PLATEAU LATE...WILL GO A COUPLE OF DEGREES COOLER THAN
CONSENSUS GUIDANCE WITH LOWS MAINLY IN THE MID 60S.
AS FOR FRI...WILL CONTINUE CLOSE TO PREVIOUS MORNING FORECAST
REASONING CONCERNING FRI ALSO...WITH SHWRS/TSTMS LIKELY AREA WIDE
DURING AT LEAST THE MORNING HRS. WITH SOME TIMING UNCERTAINTIES
STILL IN PLAY THOUGH TO ACTUAL MOVEMENT AND EVENTUAL DISSIPATION
ACROSS THE MID STATE...ALONG WITH THE CONTINUED PRESENCE OF A WEAK
SFC BOUNDARY...EXPECT SOME CLRING POSSIBLY LATE...BUT WILL GO WITH
HIGH CHANCE POPS FOR LOCATIONS GENERALLY W OF THE PLATEAU. WILL GO
WITH A MODEL COMPROMISE ON HIGHS FOR FRI...WITH MOST LOCATIONS W OF
THE PLATEAU IN THE UPPER 80S...MID 80S PLATEAU.
AS FOR FRI NIGHT...EXPECT AN UNSETTLED WX PATTERN THRU FRI NIGHT WITH
A CHANCE OF SHWRS/TSTMS THRU THE NIGHT...WITH LOWS MAINLY IN THE LOWER
70S...UPPER 60S TO 70 PLATEAU AS UPPER LEVEL FLOW BECOMES MORE ZONAL
ORIENTATED IN NATURE...AND NOT MUCH POTENTIAL FOR OVERALL AIRMASS
MOISTURE TO SIGNIFICANTLY DRY OUT AFTER AFTERNOON MCS INFLUENCES
HAVE WEAKENED.
AS FOR SAT...AS MENTIONED ALSO IN THIS MORNINGS DISCUSSION...AND
MODELS CONSENSUS CONTINUING TO EMPHASIZE...ANOTHER SHORT WAVE IS
EXPECTED TO SCOOT EASTWARD IN THE UPPER LEVEL FLOW...ACROSS
KENTUCKY...ON SAT. HOWEVER...THIS DISTURBANCE CONTINUES TO LOOKS
TO BE A LITTLE WEAKER AND...PERHAPS...A LITTLE FURTHER N THAN THE
UPPER LEVEL FLOW PATTERN ACROSS THE MID STATE FRI NIGHT. HOWEVER...
TSTMS TO OUR N SHOULD BE CLOSE ENOUGH TO SWING SOME OUTFLOW
BOUNDARIES SWD INTO OUR OUR NRN COUNTIES. IN ADDITION...AND IT
CONTINUES TO LOOK SO...ATM ACROSS THE MID STATE WILL REMAIN
CHOCKED FULL OF MOISTURE...SUPPORTIVE OF AT LEAST SCT TSTMS DURING
THE DAY ON SAT PER DIURNAL HEATING INFLUENCES KICKING IN...AND
WILL CONTINUE WITH HIGH CHANCE POPS AREA-WIDE. WILL GO WITH HIGHS
CLOSE TO CONSENSUS GUIDANCE VALUES AROUND 90...MID 80S PLATEAU.
AS FOR SAT NIGHT...THE POTENTIAL FOR AN UPPER LEVEL EMBEDDED SHORTWAVE
PASSAGE AROUND THE BASE OF A DEVELOPING UPPER LEVEL TROUGH ACROSS AT
LEAST NRN PORTIONS OF THE MID STATE MAY BE POSSIBLE SAT NIGHT...AND
THUS WILL CONTINUE WITH A CHANCE OF SHWRS/TSTMS THRU THE NIGHT TIME
HRS. LOWS WILL MAINLY BE IN THE LOW TO MID 70S...AROUND 70 TO UPPER
60S PLATEAU.
AS FOR THE REMAINDER OF THE FORECAST PERIOD...A CONTINUANCE OF THE
OVERALL UNSETTLED WX PATTERN ON SUN AND MON...WITH A POTENTIAL DRYING
TREND TOWARD THE MID PORTION OF NEXT WEEK IS THE GENERAL TREND FOR
THE REMAINDER OF THE FORECAST PERIOD. OVERALL...IT LOOKS LIKE THE MID
STATE WILL EITHER BE POSITIONED BETWEEN A SUMMERTIME COLD FRONT TO
OUR N...AND A WARM MOIST AIRMASS TO OUR S...IF YOU LEAN MORE
TOWARD THE EURO SOLUTION...OR THIS FRONT WILL PASS THRU THE MID STATE
FROM OUR N SOMETIME LATE SUN NIGHT OR MON...AND THE AREA WILL BEGIN
TO EXPERIENCE A DRYING AND WARMING TREND...IF YOU LEAN MORE TOWARD
THE GFS SOLUTION. WITH SOME OVERALL UNCERTAINTY IN MIND...ESPECIALLY
WHEN YOU FIGURE IN THE POSSIBILITY OF A POTENTIAL SHORTWAVE PASSAGE
ACROSS THE NRN PORTIONS OF THE MID STATE ON SUN AIDING TO ADDITIONAL
POTENTIAL FOR TSTM DEVELOPMENT...BELIEVE AT THIS TIME...THAT OVERALL...
PREVIOUS FORECAST REASONING IS STILL VERY SOUND...AND OTHER THAN A
TWEEK HERE AND THERE...WILL CONTINUE TO LEAN TOWARD IT ACCORDINGLY...
I.E. MORE TOWARD THE GFS SOLUTION. THUS...WILL CONTINUE WITH THE
MENTIONING OF LIKELY SHWRS/TSTMS DURING THE DAYLIGHT HOURS ON SUN...
WITH A DRYING TREND BEGINNING TO ESTABLISH ITSELF BY MID WEEK. THIS
WILL RESULT IN TEMPS NEAR OR SLIGHTLY ABOVE SEASONABLE NORMS...WITH
HIGHS IN THE UPPER 80S TO LOWER 90S...MID 80S PLATEAU...AND LOWS
AROUND 70...MID 60S PLATEAU.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
411 PM CDT WED AUG 1 2012
.DISCUSSION...
A CLUSTER OF SEVERE STORMS HAS DEVELOPED THIS AFTERNOON OVER
PORTIONS OF WEST TENNESSEE INTO NORTHEAST MISSISSIPPI. THESE
STORMS HAVE FORMED ALONG AN OLD CONVECTIVE OUTFLOW BOUNDARY FROM
LAST NIGHTS STORMS THAT OCCURRED WEST OF THE MISSISSIPPI RIVER.
THESE STORMS CONTINUE TO WORK ON A STRONGLY UNSTABLE AIRMASS
REPRESENTED BY MLCAPE VALUES IN EXCESS OF 3000 J/KG. THE SEVERE
WEATHER THREAT SHOULD MOVE SOUTHEAST OF OUR FORECAST AREA LATER
THIS EVENING. ATTENTION WILL THEN TURN UPSTREAM TOWARDS NORTHEAST
ARKANSAS FOR LATE TONIGHT AS ADDITIONAL CONVECTION MAY DEVELOP
OVER MISSOURI AFTER MIDNIGHT.
THE MID SOUTH WILL REMAIN POSITIONED ALONG THE EASTERN PERIPHERY
OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTHERN PLAINS. A
SERIES OF MID LEVEL SHORTWAVE DISTURBANCES WILL TRAVERSE ACROSS
THE REGION THROUGH THE REMAINDER OF THE WEEK INTO NEXT WEEKEND.
THE FIRST OF SUCH SHORTWAVES IS CURRENTLY EVIDENT ACROSS WESTERN
MISSOURI ALONG WITH AN ASSOCIATED MCV (MESOSCALE CONVECTIVE
VORTEX). MODELS CONTINUE TO INDICATE THAT A LOW LEVEL JET WILL
STRENGTHEN LATER TONIGHT OVER THE SOUTHERN PLAINS AND NOSE INTO A
STALLED SURFACE BOUNDARY STRETCHED ACROSS SOUTHERN MISSOURI INTO
SOUTHERN KENTUCKY. NEW THUNDERSTORM DEVELOPMENT CAN BE EXPECTED
LATER THIS EVENING OVER SOUTHERN MISSOURI WHICH SHOULD DROP
SOUTHEAST INTO NORTHWEST PORTIONS OF THE MID SOUTH AFTER MIDNIGHT
IN NORTHWEST FLOW ALOFT. THIS CLUSTER WILL DIMINISH ACROSS WESTERN
AREAS DURING THURSDAY MORNING BUT NEW CONVECTION MAY INITIATE
DURING PEAK HEATING AGAIN OVER PORTIONS OF THE REGION ALONG
CONVECTIVE OUTFLOWS. HOT AND HUMID WEATHER WILL CONTINUE WITH HEAT
INDEX VALUES AGAIN REACHING OR EXCEEDING 105 DEGREES IN MOST
AREAS. THE HEAT ADVISORY HAS BEEN EXTENDED THROUGH 7 PM THURSDAY.
ANOTHER MORE SIGNIFICANT SHORTWAVE ROUNDS THE TOP OF THE RIDGE ON
THURSDAY NIGHT INTO FRIDAY. THIS SHOULD AGAIN GENERATE ADDITIONAL
SHOWERS AND THUNDERSTORMS. THE ATMOSPHERE SHOULD REMAIN UNSTABLE
SO A FEW SEVERE STORMS CANNOT BE RULED OUT.
THE THIRD MOST SIGNIFICANT WAVE SHOULD APPROACH ON SUNDAY AND
FORCE A COLD FRONT INTO THE REGION. ONCE AGAIN...SCATTERED
CONVECTIVE COVERAGE WITH A SEVERE POTENTIAL CAN BE EXPECTED.
THE FRONT SHOULD DROP INTO SOUTHERN PORTIONS OF THE AREA BY EARLY
NEXT WEEK AS THE UPPER RIDGE REBUILDS BACK INTO THE AREA FROM THE
WEST. THIS WILL BRING AN END TO THE CONVECTIVE CHANCES AND ALLOW
TEMPERATURES TO AGAIN HEAT UP FOR THE END OF THE EXTENDED FORECAST
PERIOD.
JLH
&&
.AVIATION...
18Z TAF SET
SHRAS CONTINUE TO DRIFT SOUTHEASTWARD ACROSS THE CWA. THE SHRAS
ARE ASSOCIATED WITH A DISTURBANCE. BOTH THE HRRR AND NAM SHOW THAT
ACTIVITY MAY BLOSSOM OVER THE NEXT COUPLE OF HOURS AS THE
DISTURBANCE INTERACTS WITH DAYTIME HEATING. AN ANOTHER DISTURBANCE
CURRENTLY OVER EASTERN KANSAS MAY ALSO MOVE INTO THE AREA LATER
TONIGHT FOLLOWED BY ANOTHER ONE BY 12Z. THIS GIVES AT LEAST KJBR
AND POSSIBLY KMEM MULTIPLE CHANCES OF SEEING A SHRA/TSRA.
PINPOINTING TIMING TOO HARD AT THIS POINT. WILL HAVE TEMPO GOING
AT ONSET OF TAFS FOR WHAT IS CURRENTLY GOING ON THEREAFTER WILL
JUST USE VICINITY WORDING. SOME PATCHY FOG MAY ALSO DEVELOP AT
KMKL OVERNIGHT.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 78 96 77 96 / 20 30 30 40
MKL 74 97 75 93 / 30 20 30 50
JBR 74 95 74 96 / 30 30 40 40
TUP 73 98 74 94 / 80 20 20 40
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY 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 THURSDAY FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1222 PM CDT WED AUG 1 2012
.UPDATE... /ISSUED 1148 AM CDT WED AUG 1 2012/
UPDATED TO RAISE TEMPERATURES IN THE EAST AND EXPAND CHANCE POPS
EASTWARD FOR THIS AFTERNOON.
&&
.DISCUSSION...
THE MID SOUTH REMAINS ALONG THE EASTERN PERIPHERY OF THE UPPER
RIDGE CENTERED OVER THE SOUTHERN PLAINS. NEW CONVECTION IS NOW
BEGINNING TO GENERATE ALONG OUTFLOW BOUNDARIES GENERATED BY A
DECAYED MCS (MESOSCALE CONVECTIVE SYSTEM) THAT HAS MOVED INTO
WESTERN PORTIONS OF THE MID SOUTH. THE ATMOSPHERE HAS BECOME
MODERATELY UNSTABLE WITH MLCAPES BETWEEN 1500-2500 J/KG...BUT
THERE REMAINS SOME RESIDUAL SUBSIDENCE/CAPPING AS NOTED BY SLOW
DEVELOPMENT OF ONGOING CONVECTION. AS HEATING CONTINUES...THE
ATMOSPHERE SHOULD CONTINUE TO DESTABILIZE ACROSS WESTERN SECTIONS
SO A STRONG STORM CANNOT BE RULED OUT LATER THIS AFTERNOON.
COVERAGE SHOULD STILL REMAIN SCATTERED EVEN ACROSS WESTERN AREAS.
TEMPERATURES WILL BE ABLE TO SOAR INTO THE UPPER 90S IN THE WEST
WITH BREAKS IN CLOUD COVER AND NEAR OR TOP 100 DEGREES EAST OF THE
MISSISSIPPI RIVER WITH LESS CLOUD COVER. HIGH HUMIDITY WILL
CONTINUE WITH LOW TO MID 70S DEWPOINTS PERSISTING.
UPDATES TO THE FORECAST AND GRIDS HAVE BEEN SENT.
JLH
&&
.PREV DISCUSSION... /ISSUED 314 AM CDT WED AUG 1 2012/
CURRENTLY THE MIDSOUTH WAS MOSTLY CLEAR WITH A FEW AREAS SEEING
PATCHY FOG. TEMPERATURES WERE RUNNING A FEW DEGREES COOLER THAN
LAST NIGHT DUE TO THIS RADIATIONAL COOLING...WITH WINDS EITHER
CALM OR LIGHT FROM THE SOUTH. RADAR WAS SHOWING AN AREA OF SHOWERS
AND A FEW THUNDERSTORMS ACROSS SOUTHWEST MISSOURI AND NORTH
CENTRAL ARKANSAS. MOVEMENT OF ACTIVITY WAS TOWARDS THE SOUTHEAST
AT 35 MPH.
FOR TODAY AND THURSDAY...PATCHY FOG EXPECTED TO PERSIST THROUGH 7 AM
THIS MORNING WITH VISIBILITIES AT TIMES DOWN TO ONE MILE. AFTER
SUNRISE THICKER CLOUD COVER FROM UPSTREAM CONVECTION WILL MOVE
INTO THE WESTERN HALF OF THE MIDSOUTH WITH A FEW SHOWERS LIKELY TO
PUSH INTO EASTERN ARKANSAS BEFORE 10 AM. MODELS ARE IN GOOD
AGREEMENT THAT A SHORTWAVE TROUGH SEEN ON WATER VAPOR ACROSS THE
CENTRAL CORN BELT WILL DROP SOUTHEAST THIS AFTERNOON SPREADING THE
RISK FOR ISOLATED STORMS EASTWARD THROUGH THE REMAINDER OF THE
MIDSOUTH COUNTIES. THICKEST CLOUD COVER THOUGH WILL REMAIN OVER THE
WESTERN HALF OF THE CWA. FOR THAT REASON HAVE LOWERED TEMPERATURES
A COUPLE OF DEGREES AND CANCELLED THE EXCESSIVE HEAT WATCH IN THE
SOUTHWEST DELTA COUNTIES. MORE SUN WILL BE SEEN FURTHER EAST WITH
TEMPERATURES LIKELY TO BE SLIGHTLY WARMER THAN YESTERDAY.
DEWPOINTS WILL REMAIN IN THE LOW TO MID 70S WITH HEAT INDICES
TOPPING OUT INTO THE 104-108F RANGE. THUS THE EXTENSION OF THE
HEAT ADVISORY EASTWARD APPEARS TO BE ON TRACK. WILL ALSO LEAVE THE
MENTION OF AN ISOLATED STRONG STORM IN THE HWO...WITH CONVECTION
EXPECTED TO WANE TONIGHT BEHIND THE SHORTWAVE. NEARLY THE SAME
PATTERN IS SHAPING UP FOR THURSDAY WITH THE SLIGHTLY BETTER
CHANCES FOR RAIN REMAINING ALONG AND WEST OF THE MISSISSIPPI
RIVER. TEMPERATURES WILL COOL TO MORE WIDESPREAD MID 90S AND A HEAT
ADVISORY MAY BE NEEDED FOR PORTIONS OF THE MIDSOUTH. WILL ALLOW
THE DAY CREW TO NARROW THAT POSSIBILITY DOWN.
FRIDAY THROUGH SUNDAY...MODELS INDICATE INCREASED RAIN CHANCES THIS
PERIOD AS A MIDWEST COLD FRONT/SHORTWAVE APPROACHES THE REGION.
THE GFS AND NAM ARE MORE BULLISH WITH THE STRENGTH OF BOTH
FEATURES THAN THE EURO AND ARE SLIGHTLY FASTER. HAVE TAKEN A BLEND
OF THE MODELS WITH POPS EXPECTED IN THE 30 TO 50 PERCENT RANGE
EACH DAY. A BETTER CHANCE OF A SEVERE STORM IS ALSO NOTED FOR THIS
TIME FRAME. TEMPERATURES WILL HOLD INTO THE LOW AND MID 90S WITH
A MIX OF CLOUDS AND SUN. DEWPOINTS SHOULD REMAIN IN THE 70S...WITH
UPPER 60S DIPPING INTO THE NORTHERN COUNTIES BEHIND THE FRONT BY
SUNDAY. FOR NOW...HEAT INDICES APPEAR TO BE BELOW 104 DEGREES.
EXTENDED PERIOD...LINGERING CONVECTION IS ANTICIPATED ACROSS THE FAR
SOUTH ON MONDAY AND TUESDAY AS THE FRONT DISSIPATES OVER THE MID
DEEP SOUTH. LIGHT NORTH WINDS WILL TEMPORARILY DRY OUT THE
NORTHERN HALF OF THE MIDSOUTH...WITH HIGH TEMPERATURES REMAINING
IN THE 90 TO 95 DEGREE RANGE.
JAB
&&
.AVIATION...
18Z TAF SET
SHRAS CONTINUE TO DRIFT SOUTHEASTWARD ACROSS THE CWA. THE SHRAS
ARE ASSOCIATED WITH A DISTURBANCE. BOTH THE HRRR AND NAM SHOW THAT
ACTIVITY MAY BLOSSOM OVER THE NEXT COUPLE OF HOURS AS THE
DISTURBANCE INTERACTS WITH DAYTIME HEATING. AN ANOTHER DISTURBANCE
CURRENTLY OVER EASTERN KANSAS MAY ALSO MOVE INTO THE AREA LATER
TONIGHT FOLLOWED BY ANOTHER ONE BY 12Z. THIS GIVES AT LEAST KJBR
AND POSSIBLY KMEM MULTIPLE CHANCES OF SEEING A SHRA/TSRA.
PINPOINTING TIMING TOO HARD AT THIS POINT. WILL HAVE TEMPO GOING
AT ONSET OF TAFS FOR WHAT IS CURRENTLY GOING ON THEREAFTER WILL
JUST USE VICINITY WORDING. SOME PATCHY FOG MAY ALSO DEVELOP AT
KMKL OVERNIGHT.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 99 78 97 77 / 30 20 30 20
MKL 98 72 97 73 / 20 20 20 20
JBR 97 75 96 76 / 30 30 30 20
TUP 98 73 98 74 / 20 10 20 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING 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 8 PM CDT THIS EVENING FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
325 PM CDT WED AUG 1 2012
.VERY SHORT TERM...TONIGHT AND THURSDAY.
CURRENT ELEVATED CONVECTION ACROSS NORTHERN WISCONSIN ASSOCIATED
WITH LOW LEVEL WARM AIR ADVECTION AND NOSE OF 30 KNOT PLUS WESTERLY
LOW LEVEL JET. THIS CONVECTION SHOULD SHIFT SOUTHEAST TOWARD CENTRAL
TO EAST CENTRAL WISCONSIN BUT WEAKEN...AS CAPPED AIRMASS LINGERS IN
SOUTHERN WISCONSIN. THIS IS SUPPORTED BY 16Z RUN OF HRRR MODEL. MAY
SEE SOME LEFTOVER DEBRIS CLOUDS MOVE THROUGH THE AREA LATER THIS
AFTERNOON INTO THE EARLY EVENING. WILL GO DRY FOR NOW IN THE FAR
NORTHERN COUNTIES THROUGH THE REST OF THE DAY.
SURFACE COLD FRONT SHIFTS SOUTHEAST TOWARD THE AREA TONIGHT...THEN
SLOWLY SOUTHWARD THROUGH THE AREA ON THURSDAY. WARM AIR ADVECTION
CONTINUES AHEAD OF THE FRONT TONIGHT...WITH THE RIGHT REAR QUADRANT
OF A 250MB JET STREAK PUSHING THROUGH LATER TONIGHT INTO THURSDAY
MORNING.
AREA FORECAST SOUNDINGS FROM NAM AND RAP SHOWING CAP FOR SURFACE
BASED PARCELS TONIGHT AND THURSDAY...WITH MODEST ELEVATED CAPES
AROUND 500 J/KG. LOW LEVELS REMAIN DRY...WITH SOME MID LEVEL
MOISTURE MOVING INTO THE AREA LATER TONIGHT INTO THURSDAY. HRRR
MODEL TRIES TO DEVELOP AN AREA OF CONVECTION IN SOUTHERN MINNESOTA
ALONG COLD FRONT AND BRING IT TOWARD THE WESTERN COUNTIES AFTER
MIDNIGHT TONIGHT.
FOR NOW...WILL BRING IN CHANCE POPS FROM NORTHWEST TO SOUTHEAST
TONIGHT. LINGERED CHANCE POPS THURSDAY MORNING IN THE NORTHERN
COUNTIES...LOWER TO THE SOUTH...WITH LOWER END POPS DURING THE
AFTERNOON.
TEMPERATURES WILL BE TRICKY DEPENDING ON HOW MUCH MID LEVEL
CLOUDINESS DEVELOPS/MOVES THROUGH THE AREA. WENT SOMEWHAT LOWER THAN
WARM 925MB TEMPERATURES FROM NAM...UPPER 60S TONIGHT WITH UPPER 80S
TO LOWER 90S THURSDAY. LAKE BREEZE IN THE AFTERNOON
.SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY.
WEAK Q-VECTOR CONVERGENCE AND FRONTEGENETICAL FORCING MAY RESULT IN
A FEW SHOWERS OR THUNDERSTORMS LINGERING INTO THURSDAY EVENING OVER
THE NORTHERN AREAS. BOTH ECMWF AND NAM SHOW THIS WEAK FORCING...BUT
WILL BE LIMITED BY DRYING MID LEVELS. SLIGHTLY BETTER FORCING
FARTHER NORTH...SO WL ONLY GO WITH SCHC POPS FOR NOW.
LOW LEVEL MIXING SHOULD PREVENT SIGNIFICANT FOG LATER THURSDAY
NIGHT. SHORT WAVE RIDGING AHEAD OF NEXT WEATHER SYSTEM IS EXPECTED
TO BRING A PLEASANT DAY FOR FRIDAY...WITH UNSETTLED CONDITIONS
FOCUSED TO THE SOUTH AND WEST OF WI.
SHORT TERM GUIDANCE IN SURPRISINGLY GOOD AGREEMENT ON MORE VIGOROUS
SHORT WAVE TROF MOVING ACROSS SOUTHERN CANADA AND THE WESTERN
GTLAKES FRIDAY NIGHT THROUGH SATURDAY NIGHT. ASSOCIATED LOW
PRESSURE WILL DRAG A COLD FRONT ACROSS SOUTHERN WI AND LAKE MICHIGAN
DURING PEAK HEATING OF THE AFTN AND EVE. WITH SFC DEWPTS LIKELY TO
BE IN THE MID 60S TO LOW 70S...SFC BASED CAPE VALUES MAY CLIMB TO
ABV 3000 J/KG. BULK SHEAR WILL BE STRONG ENOUGH...IN THE 25 TO 40KT
RANGE. LOW LEVEL JETS REMAIN FOCUSED FARTHER SOUTH ALONG WARM FRONT
AND NORTH...CLOSER TO LOW PRESSURE. HENCE WL KEEP POPS IN HIGH
CHANCE CATEGORY INTO SAT NGT...AND MENTION POSSIBILITY OF SEVERE IN
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY.
VIGOROUS SHORT WAVE TROUGH AND COLD FRONT PUSH EAST OF WISCONSIN
SATURDAY NIGHT...USHERING COOLER AND DRY CONDITIONS INTO THE REGION
FOR SUNDAY AND MONDAY. GFS ENSEMBLES IN FAIRLY GOOD AGREEMENT ON
THIS SCENARIO.
EXTENDED OUTLOOK TURNS MORE MURKY HEADING INTO MID-WEEK AS BOTH
ECMWF AND GFS HAVE BEEN FLIP-FLOPPING ON UPPER LEVEL STEERING FLOW.
LATEST SOLUTIONS HAVE TRENDED TOWARD MORE PROGRESSIVE WEST-NORTHWEST
STEERING FLOW FOR THE LATER HALF OF THE PERIOD. UKMT...GFS AND
ECMWF SOLUTIONS CARRY WEAK FRONTAL BOUNDARY THROUGH WI SOMETIME IN
THE MON NGT/TUESDAY TIME FRAME...WITH FRONT POSSIBLY BECOMING
STATIONARY ACROSS THE REGION...BUT CONFIDENCE LOW AS EXTENDED
GUIDANCE HAVING ISSUES WITH TIMING AND STRENGTH OF SHORT WAVE
TROFFING MOVING INTO WESTERN CONUS. AFTER COOLER...MORE SEASONAL
PERIOD ON SUNDAY AND MONDAY...85H TEMPS WARM BACK TO AROUND 20C.
GFS 5DAY ANOMOLIES SHOW RIDGING AND WARMER TEMPERATURES EXPANDING
BACK INTO THE UPPER MIDWEST LATER NEXT WEEK AHEAD OF LONG WAVE
TROUGH AMPLIFICATION IN THE EASTERN PAC/NORTHWEST CONUS.
&&
.AVIATION /00Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THURSDAY
ACROSS TAF SITES. FEW TO SCATTERED DIURNAL CUMULUS AT EASTERN TAF
SITES SHOULD DISSIPATE BY SUNSET. LIGHT SOUTH TO SOUTHWEST WINDS
EXPECTED AT MADISON DURING THIS TIME...WITH LIGHT SOUTHEAST WINDS
EVENTUALLY REACHING MILWAUKEE AND KENOSHA BY 22Z TO 23Z WEDNESDAY.
SOME MID LEVEL CLOUDS FROM STORMS TO THE NORTH MAY SHIFT THROUGH TAF
SITES LATE THIS AFTERNOON AND EARLY THIS EVENING.
SCATTERED TO BROKEN MIDDLE TO HIGH CLOUDS SHOULD GRADUALLY MOVE INTO
THE AREA LATER TONIGHT AND THURSDAY. COLD FRONT WILL SHIFT SOUTHEAST
TOWARD TAF SITES LATE TONIGHT...THEN SLIDES SOUTHWARD THROUGH TAF
SITES THURSDAY. MAY SEE SHOWERS AND STORMS APPROACH MADISON BETWEEN
06Z AND 12Z THURSDAY...AND ACROSS ALL SITES THURSDAY. HOWEVER...WILL
HOLD OFF MENTION IN TAFS FOR NOW DUE TO LOW CONFIDENCE IN AREAL
COVERAGE AND TIMING.
LIGHT WINDS WILL SHIFT TO THE NORTHEAST/EAST IN THE WAKE OF THE COLD
FRONT IN THE LATE MORNING AND EARLY AFTERNOON THURSDAY.
&&
.CONFIDENCE...
TONIGHT AND THURSDAY...MEDIUM
THURSDAY NIGHT...LOW TO MEDIUM.
FRIDAY AND FRIDAY NIGHT...MEDIUM.
SATURDAY AND SATURDAY NIGHT...MEDIUM.
SUNDAY AND MONDAY...MEDIUM TO HIGH.
TUESDAY AND WEDNESDAY...LOW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
VERY SHORT TERM/AVIATION...WOOD
SHORT TERM/LONG TERM...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
108 PM CDT WED AUG 1 2012
.SHORT TERM...
1148 AM CDT WED AUG 1 2012
HAVE UPDATED THE FORECAST FOR CURRENT TRENDS FOR THE AFTERNOON AND
ALSO A BIGGER INCREASE TO RAIN CHANCES TONIGHT.
MONITORING CURRENT TSRA/SHRA ACTIVITY OVER MN WHICH SEEMS TO BE TIED TO
THE 700MB LEVEL FORCING. THE 700MB TRANSPORT IS CONVERGENT ALONG
ITS EAST SIDE IN THE MAXIMIZED THETA-E ADVECTION AREA AT THE SAME
LEVEL AND THIS IS WHERE ACTIVITY HAS BEEN LIVING. USING RAP 01.15
RUN...THIS WOULD SUGGEST THE POTENTIAL FOR THIS TO SHIFT EAST
ACROSS THE FORECAST AREA IN THE AFTERNOON. WILL CONTINUE TO
MONITOR THIS HIGHER-BASED ACTIVITY AND MAY NEED TO UPDATE TO
HIGHER RAIN CHANCES. 12Z KMPX RAOB SUGGEST ABOUT 800 J/KG OF CAPE
FOR A PARCEL LIFTED FROM 700MB AND THIS WAS ENOUGH TO GENERATE A
HIGH-BASED TSRA WITH WIND DAMAGE OVER KMPX FORECAST AREA IN LAST
HOUR. GOES IR IMAGERY SUGGESTS THESE TOPS ARE COOLING IN SOME
AREAS BUT WARMING IN OTHERS. HAVE INCREASED CLOUD A BIT IN THE
NORTHWEST TODAY.
LATE THIS AFTERNOON AND EVENING WILL SEE A NICE INCREASE IN AN E-W
ORIENTED FRONTOGENESIS BAND IN THE 900-700 MB LAYER MOVING IN
FROM THE WEST/NORTHWEST. THIS WILL BE INCREASING AS THE CAPE IS
MAXIMIZING...PROVIDING A NICE LOW LEVEL TRIGGER FOR TSRA. TAKING A
0-2KM AGL MIXED LAYER PARCEL GENERATES 2000 J/KG ALONG THE FRONT
TO THE NORTHWEST...WITH THE 0-1KM LAYER PROVIDING 2500 J/KG OF
CAPE. SO...THE INSTABILITY WILL BE THERE AND FORCING SUGGESTS TSRA
WILL DEVELOP NW OF FORECAST AREA LATE AFTERNOON AND SHIFT IN THIS
EVENING. HRRR RUNS AGREE WITH THIS IDEA VIA REFLECTIVITY. ANY
STRONGER STORM COULD PRODUCE DAMAGING WIND GUSTS WITH
INVERTED-V...STEEP LAPSE RATE ENVIRONMENT THAT WILL BE OUT THERE
BY LATE AFTERNOON. HRRR HOURLY WIND GUST SPEED SUGGESTS 70 KTS
NEAR THE SURFACE ASSOCIATED WITH TSRA IN THE MODEL. SOMETIMES THIS
IS A GOOD INDICATOR FOR SEVERE POTENTIAL.
WITH 01.12Z AND 01.06Z NAM SUGGESTING FRONTOGENESIS AND 01.09Z
SREF PAINTING HIGHER RAIN PROBABILITIES FOR THE OVERNIGHT WITH
THIS FORCING AND STILL SOME CAPE REMAINING. SO...HAVE BUMPED RAIN
CHANCES MOST AREAS OVERNIGHT WITH MAX BEING ALIGNED ALONG I-90.
SHOULD SEE SOME STEADY RAINS WITH EMBEDDED TSRA OVERNIGHT.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
424 AM CDT THU AUG 1 2012
ON SATURDAY...THE STRONG SHORT WAVE TROUGH WILL MOVE ACROSS NORTHERN
MINNESOTA AND NORTHERN WISCONSIN. WHILE THE 0-6 KM SHEAR IS GREATER
THAN 50 KNOTS...PROFILERS SHOW THAT THAT MUCH OF THIS SHEAR IS
ASSOCIATED WITH SPEED SHEAR. THIS BRINGS UP THE QUESTION WHETHER
THIS SHEAR WILL OUTWEIGH THE AMOUNT OF INSTABILITY AVAILABLE BEHIND
THE FRONT. IF THIS DOES INDEED OCCUR...THE STORMS MAY GET SHEARED
APART...THUS LIMITING OUR SEVERE WEATHER POTENTIAL.
BEYOND THIS TIME PERIOD...IT LOOKS LIKE HIGH PRESSURE WILL PROVIDE
DRY WEATHER INTO EARLY NEXT WEEK. IN ADDITION...TEMPERATURES WILL
ONCE AGAIN CLIMB WELL ABOVE NORMAL.
&&
.AVIATION...THROUGH 18Z THURSDAY
108 PM CDT WED AUG 1 2012
INCREASING TSRA PROBABILITIES FOR THE TAF SITES THIS EVENING. A
COLD FRONT MOVING INTO MN WILL WORK WITH GROWING INSTABILITY LATE
IN THE AFTERNOON TO INITIATE TSRA ACTIVITY OVER
SOUTHCENTRAL/CENTRAL MN BY LATE AFTERNOON. THESE STORMS ARE
EXPECTED TO MOVE SOUTHEAST AND COULD AFFECT THE TAF SITES THIS
EVENING. HAVE KEPT VCTS AT THE TAF SITES AS CONFIDENCE IS NOT HIGH
ENOUGH ON THE COVERAGE OF STORMS THAT WILL OCCUR TO MOVE TO
PREVAILING/TEMPO TSRA. HOWEVER...WILL BE MONITORING RADAR FOR
DEVELOPMENT AND UPDATING THE TAF SHOULD CONFIDENCE INCREASE THAT
THE AIRFIELD WOULD BE HIT. FOR NOW...HAVE PUSHED BACK TIMING OF
VCTS TO EVENING.
THE STRONGER EVENING STORMS COULD PACK A WIND GUST THREAT TO 65KTS
SHOULD A DIRECT HIT TO THE AIRFIELD TAKE PLACE. THIS IS MAINLY
BECAUSE OF THE VERY DRY AND DEEP SUB-CLOUD LAYER WHICH WILL
ENHANCE MICROBURST TYPE THREATS.
LIFT WILL CONTINUE TO GROW AND IT APPEARS THIS WILL BE FOCUSED
OVER THE TAF SITES OVERNIGHT AS FRONTOGENESIS IN THE 900-600 MB
LAYER INCREASES. WITH SOME INSTABILITY LEFT OVERNIGHT...A BAND OF
SHRA/RA IS EXPECTED AND HAVE NOW INCLUDED THIS IN THE FORECAST.
SHOULD THE RAIN CONTINUE OVER THE TAF SITES FOR MANY
HOURS...LOWER CIGS/VSBYS WOULD RESULT AND WHILE KRST NOW WILL
INCLUDE MVFR...FUTURE FORECASTS MAY NEED TO LOWER CONDITIONS
AGAIN AT BOTH TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
424 AM CDT THU AUG 1 2012321 PM CDT TUE JUL 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BOYNE
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1233 PM CDT WED AUG 1 2012
.UPDATE...
SIMILAR SITUATION TO YESTERDAY. HIGH PRESSURE SLIDING OFF TO OUR
SOUTHEAST CONTINUES TO INFLUENCE THE WEATHER IN OUR CWA...EXPECT
QUIET CONDITIONS IN THE NEAR-TERM. NOT MANY CHANGES MADE TO THE
FORECAST PACKAGE IN THE FIRST PERIOD. TEMPERATURE TREND WAS
ADJUSTED...HOWEVER...HIGHS WERE LEFT AS IS. HIGHS WILL BE WARMER
THAN YESTERDAY BY A FEW DEGREES GIVEN WARMER TEMPS ALOFT AND LESS
CU. GIVEN THE INSOLATION AND ADEQUATE MIXING...TEMPS SHOULD MIX
DOWN FROM AT LEAST 925 HPA. 925 HPA TEMPS ON ECMWF ARE AROUND
25-28 C THAT YIELDS AROUND 89 TO 94 F...AS IS FORECASTED. NAM IS
RUNNING TOO WARM ALOFT AS HAS BEEN SEEN IN THE PAST. RAP MODEL
SOUNDINGS SHOW MIXING THROUGH AT LEAST 900 HPA. VIS SAT AND SFC OBS
CURRENTLY SHOW MOSTLY SUNNY SKIES WITH A FEW CU INLAND AND SCT CU
IN LIMITED PORTIONS OF THE LAKE SHORE COUNTIES. NOT ANTICIPATING MUCH
DIURNAL CU DEVELOPMENT TODAY. SHOULD SEE ONLY A FEW CU INLAND WITH
SCT CU LIMITED TO THE LAKE SHORE COUNTIES...AS MODEL SOUNDINGS ARE
NOTABLY MORE DRIER INLAND AT THE LOWER LEVELS.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH THURSDAY ACROSS TAF SITES. SCATTERED
DIURNAL CUMULUS SHOULD BE LIMITED TO EASTERN TAF SITES...CLOSER TO
HIGHER LOW LEVEL MOISTURE. MOSTLY SUNNY SKIES AND LIGHT SOUTH TO
SOUTHWEST WINDS EXPECTED AT MADISON THROUGH THE AFTERNOON. LIGHT
SOUTH TO SOUTHWEST WINDS WILL SHIFT SOUTHEAST AT MILWAUKEE AND
KENOSHA BY 19Z THIS AFTERNOON...MAYBE REACHING WAUKESHA BY 22Z.
SCATTERED TO BROKEN MIDDLE TO HIGH CLOUDS SHOULD GRADUALLY MOVE INTO
THE AREA LATER TONIGHT AND THURSDAY. WEAK COLD FRONT WILL SHIFT
SOUTHEAST TOWARD TAF SITES LATE TONIGHT...THEN SLIDES SOUTHWARD
THROUGH TAF SITES THURSDAY. MAY SEE SHOWERS AND STORMS APPROACH
MADISON BETWEEN 06Z AND 12Z THURSDAY...AND ACROSS ALL SITES
THURSDAY. HOWEVER...WILL HOLD OFF MENTION IN TAF DUE TO LOW
CONFIDENCE IN AREAL COVERAGE AND TIMING.
WINDS WILL SHIFT TO THE NORTH TO NORTHEAST IN THE WAKE OF THE COLD
FRONT BETWEEN 15Z AND 19Z THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 325 AM CDT WED AUG 1 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
EARLY THIS MORNING THERE WILL BE FOG IN LOW SPOTS AND RIVER VALLEYS
UNTIL 9 AM...ESPECIALLY EAST OF MADISON WHERE RAIN FELL OVERNIGHT
MONDAY. OTHERWISE QUIET WEATHER TODAY AS RIDGE OF HIGH PRESSURE
FROM IA TO WI TO LOWER MI PIVOTS TO AN IL TO LOWER MI LINE BY SUNSET.
UPSTAIRS A WEAK SHORT WAVE IS PROGGED TO SLIDE SOUTHEAST OVER WI
TODAY...WITH NO LOW-LEVEL EFFECTS DUE TO DRY AIR BELOW 10 THSD FT
AGL. MODELS VARY ON TIMING AND POSITION OF THIS SHORT WAVE...BUT
THAT DOESN/T MATTER ANYWAY.
SHORT-WAVE RIDGING ALOFT ALSO OCCURRING TODAY FOLLOWED BY THE
APPROACH OF A MORE SIGNIFICANT SHORT-WAVE BY LATE TONIGHT INTO WI.
BY LATE TONIGHT MODELS BRING ASSOCIATED SURFACE FRONT DOWN INTO
SOUTHERN WI...WITH NAM BEING THE FASTEST AND ECMWF THE WEAKEST. ALL
MODELS SHOW GENERATION OF PRECIP AFTER MIDNIGHT IN SOUTHERN WI...BUT
VARY ON TIMING/PLACEMENT/AMOUNTS. INTERESTINGLY... THE NAM KEEPS MY
COUNTY WARNING AREA /CWA/ DRY TONIGHT...THE GFS KEEPS MOST OF THE
CWA DRY...THE ECMWF HAS PCPN OVER ALL BUT THE SOUTHERN PART OF MY
CWA...AND THE CANADIAN BRINGS CONVECTION INTO SOUTHWEST AND
SOUTHCENTRAL WI COUNTIES BETWEEN 09 AND 12Z. SO WILL GO WITH CHANCE
OF SHOWERS/STORMS FOR TONIGHT OVER ALL BUT SOUTHEAST PART OF MY
CWA.
THURSDAY AND THURSDAY NIGHT - CONFIDENCE...MEDIUM
SURFACE BOUNDARY PROGGD TO SHIFT INTO FAR SRN WI OR NRN IL. NAM IS
QUICKER WITH FROPA ESTABLISHING THE NE FLOW SOONER. MEANWHILE
850/925 BAROCLINIC ZONE REMAINS WITH SOME MID LEVEL FRONTOGENETICAL
FORCING. BUFKIT SOUNDINGS SHOW SOME ELEVATED CAPE WITH LOW LEVELS
RATHER UNIMPRESSIVE MOISTURE WISE. SURFACE FORCING WILL NOT
INITATE PRECIP. WILL BE POST FRONTAL DEVELOPMENT WITHIN THE
REGION OF BEST MID LEVEL FRONTAL FOCRING. HUGE DIFFERENCES
BETWEEN GFS AND NAM MOS DEW POINTS AS MUCH AS 14 DEGREES. GFS OF
COURSE TOO MOIST SHOWING DEWS IN THE MID 70S. FAIRLY SWIFT WNW
UPPER FLOW CARRYING A SHORTWAVE THOUGH. SOME TIMING DIFFERENCES
WITH THIS. 12Z ECMWF SUGGESTS THIS WOULD CONTRIBUTE TO FORCING
THURSDAY NIGHT. THOUGH WITH FRONTOGENETICAL FORCING PROGGD TO
SHIFT FURTHER NORTH. WILL GO WITH SMALL POPS.
FRIDAY - CONFIDENCE...MEDIUM
UPPER FLOW BECOMES A BIT MORE WSW. A RIPPLE HERE AND THERE. ELEVATED
INSTABILITY APPEARS THOUGH SOUNDINGS ARE QUITE DRY IN THE LOW
LEVELS. NO 850/925 FORCING TO SPEAK OF. BETTER LOW LEVEL JET ACTION
TO THE WEST OF HERE WITH CWASP MAX TO OUR NORTHWEST.
SATURDAY AND SATURDAY NIGHT - CONFIDENCE...MEDIUM
VIGOROUS 500 MILLIBAR TROUGH DIGS INTO THE WESTERN GREAT LAKES.
FROPA AND BEST DIFFERENTIAL CYCLONIC VORTICITY ADVECTION ARRIVE
SATURDAY AFTERNOON/EVENING. MODELS HAVE TRENDED A BIT FASTER WITH
ALL SUGGESTING T-STORMS WILL BE IN THE AREA BEFORE 00Z SUNDAY.
DECENT RIGHT REAR QUADRANT DIVERGENCE ARRIVES INTO CWA DURING THE
AFTERNOON SATURDAY. BETTER LOW LEVEL JET FOCUSING IS NORTH WITH
STRONGEST DYNAMICS/VORTICITY PUNCH FOCUSING TO THE NORTH AS WELL.
CWASP NUMBERS ARE ALSO HIGHEST TO OUR NORTH AND NORTHEAST. HOWEVER
VERY WARM AND HUMID AIRMASS IN PLACE WITH FAVORABLE PLACEMENT OF
UPPER JET SUGGEST SEVERE WEATHER POTENTIAL IS STILL THERE. 0-6KM
SHEAR IS 40 KNOTS PLUS WITH FAVORABLE 576DM 1000-500 THICKNES ACROSS
CWA. 700-500 MILLIBAR LAPSE RATES AT LEAST 7C/KM...SO SOME FAVORABLE
PARAMETERS EXIST.
SUNDAY THROUGH TUESDAY - CONFIDENCE...MEDIUM
UPPER TROUGH SHIFTS EAST SUNDAY WITH NVA AND HIGH PRESSURE TAKING
HOLD INTO MONDAY. 00Z ECMWF THREW A LITTLE CURVE FOR MONDAY NIGHT
WITH A WAVE/WEAK FRONT SNEAKING IN THOUGH CONSENSUS WAS TO HOLD OFF
ON THIS FEATURE AT THIS POINT. 925 TEMPS START TO RAMP BACK UP A BIT
BY TUESDAY...REACHING THE MID/UPPER 20S CELSIUS.
AVIATION/12Z TAFS/...FOG ISSUES UNTIL ABOUT 14Z /9 AM/ THIS MORNING...
MAINLY EAST OF MADISON WHERE MORE RAIN FELL OVERNIGHT MONDAY.
VSBYS BOUNCED UP AND DOWN AT WEST BEND FROM 3/4 TO 10 MILES. WILL
PROBABLY GO WITH VARIATIONS OF 1 TO 3 MILES IN THE KUES AND KENW
TAFS AND 5 MI IN THE KMKE TAF. SURFACE HIGH PRESSURE RIDGE MOVES
SOUTHEAST OUT OF WI TODAY ALLOWING FOR SOUTH WINDS TO DEVELOP AT
SURFACE. OTHERWISE THE USUAL DIURNAL CUMULUS CLOUDS AROUND 5 THSD
FT AGL TODAY WITH HEATING...BUT ONLY SCATTERED AND FEWER IN
NUMBERS COMPARED TO TUESDAY/S AMOUNTS. MULTIPLE LAYERS OF MID AND
UPPER LEVEL CLOUDS BY LATE TONIGHT...WITH SCATTERED CUMULUS BELOW.
WITH APPROACH OF A SURFACE FRONT LATE TONIGHT WILL HAVE TO HAVE A
CHANCE OF STORMS. ONLY KENW WILL NOT HAVE A CHANCE OF STORMS LATE
TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/WOOD
TODAY/TONIGHT AND AVIATION/MARINE...KAPELA
THURSDAY THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 AM CDT WED AUG 1 2012
.SHORT TERM...
1148 AM CDT WED AUG 1 2012
HAVE UPDATED THE FORECAST FOR CURRENT TRENDS FOR THE AFTERNOON AND
ALSO A BIGGER INCREASE TO RAIN CHANCES TONIGHT.
MONITORING CURRENT TSRA/SHRA ACTIVITY OVER MN WHICH SEEMS TO BE TIED TO
THE 700MB LEVEL FORCING. THE 700MB TRANSPORT IS CONVERGENT ALONG
ITS EAST SIDE IN THE MAXIMIZED THETA-E ADVECTION AREA AT THE SAME
LEVEL AND THIS IS WHERE ACTIVITY HAS BEEN LIVING. USING RAP 01.15
RUN...THIS WOULD SUGGEST THE POTENTIAL FOR THIS TO SHIFT EAST
ACROSS THE FORECAST AREA IN THE AFTERNOON. WILL CONTINUE TO
MONITOR THIS HIGHER-BASED ACTIVITY AND MAY NEED TO UPDATE TO
HIGHER RAIN CHANCES. 12Z KMPX RAOB SUGGEST ABOUT 800 J/KG OF CAPE
FOR A PARCEL LIFTED FROM 700MB AND THIS WAS ENOUGH TO GENERATE A
HIGH-BASED TSRA WITH WIND DAMAGE OVER KMPX FORECAST AREA IN LAST
HOUR. GOES IR IMAGERY SUGGESTS THESE TOPS ARE COOLING IN SOME
AREAS BUT WARMING IN OTHERS. HAVE INCREASED CLOUD A BIT IN THE
NORTHWEST TODAY.
LATE THIS AFTERNOON AND EVENING WILL SEE A NICE INCREASE IN AN E-W
ORIENTED FRONTOGENESIS BAND IN THE 900-700 MB LAYER MOVING IN
FROM THE WEST/NORTHWEST. THIS WILL BE INCREASING AS THE CAPE IS
MAXIMIZING...PROVIDING A NICE LOW LEVEL TRIGGER FOR TSRA. TAKING A
0-2KM AGL MIXED LAYER PARCEL GENERATES 2000 J/KG ALONG THE FRONT
TO THE NORTHWEST...WITH THE 0-1KM LAYER PROVIDING 2500 J/KG OF
CAPE. SO...THE INSTABILITY WILL BE THERE AND FORCING SUGGESTS TSRA
WILL DEVELOP NW OF FORECAST AREA LATE AFTERNOON AND SHIFT IN THIS
EVENING. HRRR RUNS AGREE WITH THIS IDEA VIA REFLECTIVITY. ANY
STRONGER STORM COULD PRODUCE DAMAGING WIND GUSTS WITH
INVERTED-V...STEEP LAPSE RATE ENVIRONMENT THAT WILL BE OUT THERE
BY LATE AFTERNOON. HRRR HOURLY WIND GUST SPEED SUGGESTS 70 KTS
NEAR THE SURFACE ASSOCIATED WITH TSRA IN THE MODEL. SOMETIMES THIS
IS A GOOD INDICATOR FOR SEVERE POTENTIAL.
WITH 01.12Z AND 01.06Z NAM SUGGESTING FRONTOGENESIS AND 01.09Z
SREF PAINTING HIGHER RAIN PROBABILITIES FOR THE OVERNIGHT WITH
THIS FORCING AND STILL SOME CAPE REMAINING. SO...HAVE BUMPED RAIN
CHANCES MOST AREAS OVERNIGHT WITH MAX BEING ALIGNED ALONG I-90.
SHOULD SEE SOME STEADY RAINS WITH EMBEDDED TSRA OVERNIGHT.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
424 AM CDT THU AUG 1 2012
ON SATURDAY...THE STRONG SHORT WAVE TROUGH WILL MOVE ACROSS NORTHERN
MINNESOTA AND NORTHERN WISCONSIN. WHILE THE 0-6 KM SHEAR IS GREATER
THAN 50 KNOTS...PROFILERS SHOW THAT THAT MUCH OF THIS SHEAR IS
ASSOCIATED WITH SPEED SHEAR. THIS BRINGS UP THE QUESTION WHETHER
THIS SHEAR WILL OUTWEIGH THE AMOUNT OF INSTABILITY AVAILABLE BEHIND
THE FRONT. IF THIS DOES INDEED OCCUR...THE STORMS MAY GET SHEARED
APART...THUS LIMITING OUR SEVERE WEATHER POTENTIAL.
BEYOND THIS TIME PERIOD...IT LOOKS LIKE HIGH PRESSURE WILL PROVIDE
DRY WEATHER INTO EARLY NEXT WEEK. IN ADDITION...TEMPERATURES WILL
ONCE AGAIN CLIMB WELL ABOVE NORMAL.
&&
.AVIATION...TODAY AND TONIGHT
638 AM CDT WED AUG 1 2012
FOCUS IS ON THUNDERSTORM CHANCES THIS AFTERNOON THROUGH TONIGHT
ASSOCIATED WITH COLD FRONT DROPPING SOUTH ACROSS THE TAF SITES.
DEEP MIXING AND SOUTHERLY WINDS WILL BE FOUND FOR MUCH OF
TODAY...WITH COULD LEAD TO SOME GUSTY WINDS UP TO 20 KTS AT BOTH
KRST/KLSE. BY 01.22Z...SURFACE FRONT SHOULD BE ALONG A FSD TO MSP TO
HYR LINE AND SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
RIGHT ALONG AND BEHIND IT...ASSOCIATED WITH GREATEST 700 TO 850 MB
FRONTOGENESIS. 700 MB MOISTURE TRANSPORT IS LIMITED HOWEVER...AND
THERE IS QUESTION AS TO COVERAGE OF STORMS SO FEEL MAINTAINING VCTS
AND VFR CONDITIONS AT BOTH KRST/KLSE IS APPROPRIATE. THE LOWEST
2-2.5 KM ARE VERY DRY / INVERTED V SOUNDING / SO ANY STORMS THAT
DO DEVELOP COULD PRODUCE STRONG WINDS...ALONG WITH MVFR VISIBILITIES.
BEST TIMING LOOKS TO BE FROM 23Z THROUGH 06Z...THOUGH LATEST NAM
KEEPS STORMS ALONG SOUTHERN MINNESOTA / WESTERN WISCONSIN THROUGH
09Z. WINDS WILL GRADUALLY TURN TO THE NORTH BY 02.12Z AS FRONT
DROPS SOUTH OF TAF SITES...WITH BROKEN MID LEVEL CLOUDS LINGERING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
424 AM CDT THU AUG 1 2012321 PM CDT TUE JUL 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1104 PM MDT THU AUG 2 2012
.AVIATION...
VFR CONDITIONS EXPECTED AT ALL 3 TAF SITES...KCOS...KPUB AND KALS
NEXT 24H. THERE WILL BE A SLIGHT CHANCE OF THUNDER DURING THE LATE
AFTERNOON/EARLY EVENING BUT PROBABILITY TOO LOW TO MENTION
EXPLICITLY IN TAF PRODUCTS ATTM.
&&
.PREV DISCUSSION... /ISSUED 328 PM MDT THU AUG 2 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
THE MONSOON MOISTURE PLUME REMAINS OVER THE AREA WITH SHOWERS AND
THUNDERSTORMS OVER AND NEAR THE MOUNTAINS EARLY THIS AFTERNOON. THE
MODELS ARE SHOWING THE CONVECTIVE ACTIVITY SPREADING ACRS THE
PLAINS LATE THIS AFTERNOON THROUGH THE EVENING HOURS...IN
ASSOCIATION WITH A WEAK DISTURBANCE WORKING ITS WAY EAST ACRS
SOUTHERN CO. THE HRRR SHOWS A BAND OF PCPN COMING OFF THE MTS BY
00Z...MOVING EASTWARD ACRS THE PLAINS AND EXITING CO BY 04Z. THE
NSSL 4KM WRF IS VERY SIMILAR. BASED ON THESE HIGH RES MODELS WL GO
AHEAD AND END PCPN CHANCES IN THE FORECAST BY MIDNIGHT...HOWEVER
BOTH THE NAM AND GFS KEEP CHANCES FOR PCPN OVR THE FAR SERN PLAINS
THROUGH THE NIGHT AND INTO FRI MORNING. THERE IS THE POTENTIAL FOR
HEAVY RAIN TODAY UNDER SOME OF THE STRONGER STORMS...WITH THE WALDO
CANYON BURN SCARS BEING THE MOST VULNERABLE IF HEAVY RAIN DEVELOPS
OVR THAT AREA.
ON FRI THE BULK OF THE MONSOON MOISTURE WILL BE OVR SOUTHERN
PORTIONS OF THE FORECAST AREA...AS AN UPR TROF OVR THE NRN ROCKIES
FLATTENS THE RIDGE OVR OUR AREA. THUS THE BEST CHANCES FOR
CONVECTIVE ACTIVITY SHOULD OCCUR OVR THE SRN HALF OF THE CWA. THE
GFS HAS LITTLE IN THE WAY OF PCPN COVERAGE FOR FRI AFTERNOON...WHILE
THE NAM HAS A LITTLE MORE COVERAGE OVER THE FAR SOUTHEAST
PLAINS...THE SANGRES AND THE EASTERN SAN JUANS. HIGH TEMPS ON FRIDAY
SHOULD BE A FEW DEGREES ABOVE NORMAL IN MOST LOCATIONS.
LONG TERM...
(FRIDAY NIGHT THROUGH THURSDAY)
LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE POPS AND
TEMPERATURES. LATEST COMPUTER SOLUTIONS INDICATE THAT STRONG UPPER
RIDGE CENTERED OVER NORTHWESTERN TEXAS AT 00Z SATURDAY WILL BEGIN
TO PUSH WEST INTO NEW MEXICO BY LATER SUNDAY BEFORE BECOMING
CENTERED NEAR THE 4-CORNERS REGION BY NEXT TUESDAY. IN
ADDITION...HEALTHY NORTHERLY SURGE IS PROJECTED TO PUSH ACROSS
EASTERN SECTIONS OF THE FORECAST DISTRICT BY SATURDAY MORNING.
ENOUGH ATMOSPHERIC MOISTURE IS EXPECTED TO REMAIN AVAILABLE OVER
THE FORECAST DISTRICT AND COMBINE WITH OCCASIONAL UPPER WAVES AND
THE DAILY HEATING CYCLE/SURFACE BOUNDARIES TO ALLOW DAILY ISOLATED
TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE HIGHER TERRAIN REGIONS.
SOME OF THE STRONGER THUNDERSTORMS ARE EXPECTED TO PRODUCE PERIODS
OF LOCALLY HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED FLASH
FLOODING ISSUES...ESPECIALLY IF A STORM DIRECTLY IMPACTS BURN SCAR
AREAS...SUCH AS THE WALDO BURN SCAR. IN ADDITION...THE STRONGER
STORMS WILL ALSO BE CAPABLE OF PRODUCING HAZARDOUS LIGHTNING...HAIL
AND GUSTY WINDS.
FINALLY...BELOW SEASONAL MAXIMUM TEMPERATURES SHOULD BE NOTED IN
THE WAKE OF THE STRONG NORTHERLY SURGE SATURDAY(ESPECIALLY EASTERN
SECTIONS) WITH MAXIMUM TEMPERATURES THEN REBOUNDING TO ABOVE
EARLY AUGUST SEASONAL AVERAGES NEXT WEEK.
AVIATION...
KALS...KCOS AND KPUB WILL HAVE VFR CONDITIONS MOST OF THE TIME
DURING THE NEXT 24 HRS. THERE WILL BE A CHANCE FOR SHOWERS AND
THUNDERSTORMS AT OR IN THE VCNTY OF THE TAF SITES THROUGH AROUND
03Z. THUNDERSTORMS COULD BRING BRIEF MVFR CONDITIONS TO THE TAF
SITES. OUTFLOW WINDS COULD ALSO BRING WIND GUSTS UP TO 45 KTS.
ON FRIDAY AFTERNOON WE COULD SEE SOME THUNDERSTORMS IN THE VCNTY OF
THE TAF SITES AFTER 20Z...BUT CONFIDENCE IS LOW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34/34
AREA FORECAST DISCUSSION
NWS DES MOINES IA
335 AM CDT FRI AUG 3 2012
.SHORT TERM /TODAY/...
MOST IMMEDIATE CONCERN INVOLVES FATE OF SMALL MCS ALONG SD/NE
BORDER. CLUSTER IS ELEVATED...MOST LIKELY ALONG 310K ISENT
SURFACE...WITHIN STRONG MLCIN. RAP SUGGESTS MOISTURE TRANSPORT AND
CONVERGENCE ALONG THIS SURFACE WILL MAINTAIN ITSELF TO OUR WEST WITH
LITTLE MOVEMENT INTO THE MORNING SO WILL LEAVE OUR FORECAST DRY
TODAY. RECENT UPSTREAM DEVELOPMENT SUPPORTS THIS SCENARIO AS WELL.
NONE OF THE EXPLICIT OR PARAMETERIZED MODEL GUIDANCE SUGGESTS THIS
WILL MAINTAIN ITSELF EASTWARD INTO IA EITHER.
NEXT CONCERN WILL BE TEMPS. FORECAST SOUNDINGS AND LOW LEVEL TEMP
CHANGE FROM YESTERDAY SUGGEST HIGHS MAY BE A FEW DEGREES WARMER
WHICH MAKES SENSE AS LOW LEVEL WINDS SLOWLY VEER AND INCREASE
SLIGHTLY. TRIMMING A FEW DEGREES OFF THE OFTEN OVERAGGRESSIVE TOO
SUPER ADIABATIC NAM SUGGESTS HIGHS IN THE MID/UPPER 90S. LOWERING
DEWPOINTS WITH MIXING THIS AFTERNOON WILL KEEP HEAT INDICES
PLUS/MINUS A FEW DEGREES OF THE ACTUAL TEMPERATURE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
MODELS ARE A LITTLE SLOWER WITH THE SHORTWAVE TONIGHT ALSO THE BEST
FORCING. AS A RESULT A BACKED OFF ON POPS THIS EVENING AND ON AREAL
EXTENT OF POPS OVERNIGHT. UPPER TROUGH AND SURFACE COLD FRONT MOVE
THROUGH MOST OF CENTRAL IOWA DURING THE MORNING INTO EARLY
AFTERNOON. WHILE THE SYSTEM IS DYNAMIC...IT MOVES THROUGH MUCH OF
THE CWA BEFORE PEAK HEATING SO THE BEST INSTABILITY WON/T BE
REALIZED UNTIL THE SYSTEM IS MOSTLY EAST OF THE CWA. THE
INTERESTING THING TO FORECAST FOR SATURDAY WILL BE TEMPS. SOUNDINGS
SHOW THE DAYS HIGHS OCCURRING AROUND 18Z THEN BEGINNING TO FALL
OFF. CLOUDS/PRECIP WILL IMPACT THE CWA AND THERE WILL LIKELY BE A
PRETTY BIG THERMAL GRADIENT ACROSS THE STATE WITH MID 70S NORTHWEST
AND MID 90S SOUTHEAST. SUNDAY WILL SEEM LIKE FALL WITH HIGHS IN THE
70S AND 80S. THIS WILL BE SHORT LIVED HOWEVER AS THE UPPER RIDGE
REBUILDS OVER THE WEST EARLY NEXT WEEK. WHILE TEMPS ARE FORECAST TO
WARM BACK UP INTO THE 80S AND 90S...IT WILL NOT BE AS WARM AS IT HAS
BEEN. NUMEROUS SHORTWAVES WILL RIDE ATOP THE RIDGE ACROSS IOWA BUT
TIMING AND STRENGTH OF THESE WAVES LEAVES THE POP FORECAST DIFFICULT
AT BEST. MODELS DIFFER ON INTENSITY AND TIMING BUT IN THE TUESDAY
NIGHT/WEDNESDAY TIMEFRAME ONE WAVE LOOKS LIKE IT WILL AFFECT THE
WESTERN PORTION OF THE FORECAST AREA. ANOTHER STRONGER WAVE MOVES
IN LATE IN THE EXTENDED...AROUND FRIDAY/FRIDAY NIGHT. POPS WERE HIT
HARDEST DURING THIS TIME BUT WITH MODEL DISCREPANCIES AND WEAKER
WAVES IN BETWEEN THE AFOREMENTIONED DAYS...I DID NOT FEEL SLIGHT
POPS WERE WARRANTED. HOWEVER...AS RESOLUTION BECOMES BETTER...WE
WILL LIKELY SEE OTHER PERIODS OF PRECIP DURING THE EXTENDED.
&&
.AVIATION...03/06Z
LOCALIZED SHOWERS AND THUNDERSTORMS STILL LINGERING OVER NORTHEAST
IA. LOW POTENTIAL FOR THIS ACTIVITY TO REACH KALO AND IS NOT
MENTIONED IN THE FORECAST. REMAINDER OF THE FORECAST WILL CONSIST OF
LIGHT NORTHEAST TO EAST WINDS TONIGHT BECOMING SOUTHEAST ON FRIDAY
UNDER VFR CONDITIONS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BSS
LONG TERM...FAB
AVIATION...BSS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 AM CDT FRI AUG 3 2012
...LONG TERM DISCUSSION UPDATED AT 358 AM...
.SYNOPSIS...
ISSUED AT 1000 PM CDT THU AUG 2 2012
THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED THAT STRONGER JET FLOW WAS MAINLY
CONFINED TO THE NORTHERN HALF OF THE UNITED STATES AND INTO CANADA.
FLOW IN THIS REGION WAS GENERALLY GREATER THAN 50 KT. A FEW ~75 KT JET
STREAKS WERE NOTED ACROSS BRITISH COLUMBIA, NORTHERN MICHIGAN, AND QUEBEC.
ACROSS THE SOUTHERN HALF OF THE US, FLOW WAS GENERALLY LIGHT /15-30
KT/ WITH ANTICYCLONIC FLOW MOST PROMINENT ACROSS THE SOUTHERN PLAINS.
AT 500 HPA, A STRONG 562 DM CYCLONE WITH COLD -20 DEG C TEMPS WAS LOCATED
ACROSS CENTRAL ALBERTA. A SHORTWAVE TROUGH WAS MOVING ACROSS SOUTHEASTERN
CANADA. A STRONG 595 DM ANTICYCLONE WAS DOMINATE OVER WEST TEXAS WITH
RELATIVELY WARM /-5 TO -3 DEG C/ MID LEVEL TEMPERATURES. SOME MID LEVEL
MOISTURE WAS ADVECTING TO THE NORTHEAST AROUND SAID HIGH. AT 700 HPA,
THERE WAS ABOUT A 2 DEG C COOLING BETWEEN 00Z SYNOPTIC FLIGHTS ACROSS
KDDC COUNTRY. STILL, 700 HPA TEMPERATURES WERE STILL FAIRLY WARM ACROSS
THE CENTRAL AND SOUTHERN PLAINS WITH 13 TO 16 DEG C COMMONPLACE. THIS
COOLING /ALTHOUGH SOMEWHAT MORE SIGNIFICANT/ WAS ALSO NOTED AT 850 HPA,
ALTHOUGH TEMPS SOUTHWEST OF KDDC WERE STILL VERY WARM (IN THE 30S DEG
C). AT THE SFC, A FRONTAL BOUNDARY WAS LOCATED ACROSS OKLAHOMA. ANOTHER
FRONTAL SYSTEM WAS LOCATED ACROSS THE NORTHERN HIGH PLAINS. TROPICAL
STORM ERNESTO WAS LOCATED NEAR 13.4N 58.3W AT 03.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 100 AM CDT FRI AUG 3 2012
THIS MORNING:
FIRST CONCERN FOR THE SHORT TERM PERIOD IS OVERNIGHT CONVECTION. WAS
FAIRLY LIBERAL WITH POPS GIVEN RADAR TRENDS AND THE LATEST FORECAST
PROGRESSION FROM THE HRRR. THIS ACTIVITY WILL WEAKEN AS IT HEADS EAST
ACROSS THE REGION. THERE SHOULD BE A FAIR AMOUNT OF CLOUD DEBRIS FROM
THIS CONVECTION THROUGH THE NEXT 12 HOURS WHICH WILL HAVE IMPACTS ON
HIGH TEMPERATURES LATER ON.
TODAY:
MONSOONAL MOISTURE IS WORKING ITS WAY AROUND THE STRONG MID LEVEL ANTICYCLONE
TO OUR SOUTH. IN ADDITION, STRONGER FLOW ALOFT IS EXPECTED IN ASSOCIATION
WITH THE PASSAGE OF A SHORTWAVE TROUGH WELL TO OUR NORTH. CURRENTLY
THINK ANOTHER ROUND OF CONVECTION WILL BE LIKELY THIS AFTERNOON ACROSS
THE REGION. HAVE THE HIGHEST (CHANCE POPS) ACROSS THE NORTHWEST ZONES
WHERE BETTER LOW LEVEL CONVERGENCE AND UPPER LEVEL SUPPORT WILL BE.
ALSO HAVE GONE WITH THE COOLER SIDE OF MOS GUIDANCE IN ANTICIPATION
OF RESIDUAL CLOUD OVER FROM MORNING CONVECTION AND THEN ADDITIONAL CLOUD
DEVELOPMENT THIS AFTERNOON. WOULD NOT COMPLETELY RULE OUT SEVERE WEATHER
AS SBCAPE IS FORECAST TO BE AROUND 2000 J/KG AND 0-6 KM SHEAR FORECAST
TO BE 30-40 KT. WITH 700-500 HPA LAPSE RATES AROUND 7 DEG/KM, CANNOT
COMPLETELY RULE OUT AN ISOLATED SEVERE HAIL REPORT EITHER.
TONIGHT:
HAVE A CONCERN FOR OVERNIGHT CONVECTION AGAIN THIS EVENING BUT THE ACTIVITY
SHOULD BE TRENDING DOWNWARD OVERNIGHT. PWATS DO CLIMB TO THE 75TH PERCENTILE
SO THERE COULD BE HEAVY RAIN TONIGHT. MEANWHILE, AS THE AFOREMENTIONED
UPPER LEVEL SHORTWAVE TROUGH TRAVERSES EAST, THIS WILL USHER IN A COLD
FRONT BY SATURDAY MORNING. NORTHERLY WINDS MAY BECOME ON THE BREEZY
SIDE AS 850 HPA WINDS INCREASE TO AROUND 20-30 KT IN THE WAKE OF THE FRONT.
WILL GO WITH A BLEND OF THE 00Z NAM AND 00Z ALLBLEND WHICH HAS THE FRONT
BISECTING THE REGION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 356 AM CDT FRI AUG 3 2012
THE STRONG UPPER LEVEL CYCLONE SPINNING OVER SOUTHERN ALBERTA EARLY
THIS MORNING WILL PROPAGATE EASTWARD ALONG THE CANADIAN BORDER INTO
SOUTHEASTERN MANITOBA BY SATURDAY AFTERNOON. A COLD FRONT WILL MOVE
ACROSS WESTERN KANSAS SATURDAY MORNING, AND TEMPERATURES ACTUALLY
WILL BE BELOW CLIMATOLOGICAL AVERAGES THROUGH THE WEEKEND. THE
PERSISTENT SUBTROPICAL ANTICYCLONE THAT HAS BEEN PARKED OVER THE
CENTRAL AND SOUTHERN PLAINS WILL RETROGRADE TO THE SOUTHWESTERN PART
OF THE COUNTRY EARLY NEXT WEEK BUT WILL BUILD BACK INTO THE CENTRAL
PLAINS BY THURSDAY. THE ECMWF STILL DIGS A STRONGER TROUGH INTO THE
GREAT LAKES MONDAY NIGHT AND TUESDAY THAN THE GFS AND CARRIES A WEAK
COLD FRONT INTO NORTHERN KANSAS BY TUESDAY MORNING. THE GFS ALSO
BUILDS THE UPPER LEVEL ANTICYCLONE BACK INTO THE PLAINS STRONGER
THAN THE ECMWF LATE IN THE WEEK. MOST OF THE GEM ENSEMBLE MEMBERS
SUPPORT A SOLUTION MORE SIMILAR TO THE GFS, AND THE GFS LARGELY WAS
USED FOR GRID ADJUSTMENTS IN THE EXTENDED PERIOD.
THERE LIKELY WILL BE ONGOING THUNDERSTORM ACTIVITY IN NORTHERN AND
EASTERN KANSAS SATURDAY MORNING, AND OUTFLOW FROM THE CONVECTION
PROBABLY WILL HAVE EFFECTED A SHIFT TO NORTH OR NORTHEAST WINDS
ACROSS MUCH OF WESTERN KANSAS BEFORE THE ACTUAL COLD FRONT ARRIVES.
MID LEVEL TEMPERATURES WILL BE WARM IN SOUTHWEST KANSAS, AND THERE
LIKELY WILL BE LITTLE OPPORTUNITY FOR SURFACE BASED CONVECTION WITH
THE COLD FRONT. FRONTOGENETIC FORCING IN THE BAROCLINIC ZONE BEHIND
THE SURFACE FRONTAL POSITION ALONG WITH UPPER LEVEL DIVERGENCE IN
THE ENTRANCE REGION OF THE UPPER LEVEL JET STREAK WITH THE NORTHERN
PLAINS TROUGH WILL PRODUCE SYNOPTIC SCALE UPWARD VERTICAL MOTION
OVER WESTERN KANSAS SATURDAY. POST FRONTAL SHOWERS AND THUNDERSTORMS
LIKELY WILL PERSIST FOR MUCH OF THE DAY SATURDAY AND GRADUALLY
WEAKEN BY SUNDAY EVENING AS THE BAROCLINICITY IN WESTERN KANSAS
DIMINISHES. WITH CONSIDERABLE CLOUD COVER AND LOW LEVEL COLD AIR
ADVECTION, TEMPERATURES WILL BE RELATIVELY COOL SATURDAY AND LIKELY
WILL STRUGGLE TO REACH THE MID 80S IN WEST CENTRAL KANSAS.
TEMPERATURES WILL APPROACH 100 DEGREES AGAIN IN BARBER COUNTY, WHERE
COLD AIR ADVECTION WILL NOT BEGIN IN EARNEST UNTIL AFTERNOON.
SUNDAY NIGHT WILL BE COOL IN NORTHERN KANSAS NEAR THE SURFACE
ANTICYCLONE, BUT CLOUD COVER NEAR THE OKLAHOMA BORDER WILL KEEP
TEMPERATURES RELATIVELY WARM. SHOWERS MAY PERSIST NEAR THE OKLAHOMA
BORDER SATURDAY NIGHT BUT SHOULD END BEFORE SUNRISE SUNDAY. LOW
LEVEL WINDS WILL RETURN TO THE SOUTH SUNDAY, AND TEMPERATURES WILL
BE NEAR SEASONAL AVERAGES.
WARM AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL SPREAD BACK INTO
WESTERN KANSAS ON MONDAY, AND TEMPERATURES WILL WARM BACK INTO THE
UPPER 90S IN MOST AREAS. AN UPPER LEVEL TROUGH EVIDENT ON SATELLITE
IMAGERY NEAR 30N, 130W WILL MOVE AROUND THE WESTERN UNITED STATES
ANTICYCLONE AND APPROACH THE CENTRAL PLAINS TUESDAY NIGHT AND
WEDNESDAY. A DEEP BAROCLINIC ZONE WILL BE PRESENT IN THE
CENTRAL PLAINS BETWEEN THE COOL HIGH PRESSURE IN THE MIDWEST AND
VERY WARM AIR IN THE HIGHER TERRAIN OF COLORADO, AND SCATTERED
THUNDERSTORMS MAY DEVELOP TUESDAY NIGHT AND CONTINUE WEDNESDAY AS
THE UPPER LEVEL TROUGH RIPPLES DOWN THE BAROCLINC ZONE. ANTICYCLONIC
FLOW ALOFT WILL BECOME MORE PRONOUNCED BY THURSDAY AS THE
SUBTROPICAL HIGH BUILDS BACK INTO THE CENTRAL PART OF THE COUNTRY,
AND HOT, DRY WEATHER WILL RETURN TO WESTERN KANSAS. THE UPPER LEVEL
HIGH LIKELY WILL REMAIN ENTRENCHED IN THE CENTRAL PART OF THE
COUNTRY UNTIL AT LEAST MID AUGUST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM CDT FRI AUG 3 2012
ATTENTION WAS PAID TO MAINLY TO THE FIRST 6 TO 9 HOURS OF THE TAF. FIRST
CONCERN IS CONVECTION THROUGH THE OVERNIGHT HOURS AS AN MCS PROPAGATES
EASTWARD ACROSS WESTERN KANSAS. HAVE USED RADAR TRENDS AND HRRR TO TIME
CB/TS GROUPS FOR THE TAFS. CONVECTION WILL BE POSSIBLE AGAIN LATER IN
THE TAF PERIOD, HOWEVER, WILL MAKE ADJUSTMENTS REGARDING OVERNIGHT CONVECTION
AND LATER TAF ISSUANCE CAN MODIFY TAFS AS 12Z DATA COMES IN FOR CONVECTION
LATER THIS AFTERNOON. GENERALLY CIGS SHOULD BE VFR THROUGH THE ENTIRE
TAF PERIOD. E TO SE WINDS AROUND 10 KT EXPECTED AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 72 87 61 / 40 40 30 20
GCK 95 70 85 60 / 40 50 30 10
EHA 95 69 87 62 / 40 50 30 20
LBL 97 71 88 65 / 40 40 30 20
HYS 96 71 84 59 / 40 40 30 10
P28 104 76 93 70 / 30 30 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...RUTHI
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
322 AM CDT FRI AUG 3 2012
.DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP TRENDS OVER THE NEXT 24 HOURS.
SYNOPSIS:
STRONG UPPER SHORTWAVE IS CURRENTLY APPROACHING THE NORTHERN
ROCKIES. MEANWHILE WATER VAPOR IMAGERY SHOWS THE DIRTY MONSOONAL
FLOW SPILLING MOISTURE OVER THE ROCKIES AND INTO THE HIGH PLAINS. AT
THE SURFACE THE FRONT IS LOCATED FROM EXTREME SOUTHEAST KS TO NEAR ENID
OK.
TODAY-TONIGHT:
STORMS DEVELOPED AROUND MIDNIGHT OVER SE KS IN AREA OF ISENTROPIC
LIFT ALONG THE 315K SURFACE. THE STORMS THEN FILLED BACK TO THE WEST
WHERE THE NAM SHOWED THE CAPPING THE WEAKEST ABOVE 850MB. MEANWHILE
THE MCS THAT DEVELOPED OVER EASTERN CO THU EVENING IS STILL HOLDING
TOGETHER AS IT PASSES JUST NORTH OF DDC. CURRENT THINKING IS THAT IT
WILL FOLLOW THE WEAKEST CAPPING WHICH WOULD TAKE IT NORTH OF HIGHWAY
400. WHILE WE DO FEEL IT WILL EXHIBIT AN OVERALL DECREASE IN INTENSITY
AND COVERAGE...DO THINK IT WILL AT LEAST HOLD TOGETHER LONG ENOUGH TO
AFFECT THE WESTERN PORTION OF THE FORECAST AREA.
EVEN IF THIS MCS DOES DIMINISH AS IT PASSES ACROSS THE FORECAST
AREA...IT WILL STILL PLAY HAVOC WITH TEMPS AND THE TIMING OF THE
FRONT. AT THIS POINT FEEL THE SHORT TERM MODELS MAYBE A BIT TOO
AGGRESSIVE IN LIFTING THE FRONT NORTH TODAY. WILL THEREFORE BACK-OFF
TEMPS A COUPLE DEGREES NORTH OF HIGHWAY 400. DO NOT HAVE ENOUGH
CONFIDENCE TO ADD OR REMOVE COUNTIES FROM THE CURRENT HEADLINE...SO
WILL LEAVE ALONE FOR NOW.
THE COLD FRONT WILL START ITS JOURNEY ACROSS THE CENTRAL PLAINS
TONIGHT. BUY MIDNIGHT IT IS EXPECTED TO STRETCH FROM EASTERN
NEBRASKA INTO EXTREME NORTHWEST KS...WITH THIS FEATURE ENTERING THE
NW FRINGES OF THE FORECAST AREA TOWARD SUNRISE. SCT CONVECTION
SHOULD DEVELOP SOUTH OF THE FRONT OVER CENTRAL AND EASTERN KS AS
MOISTURE TRANSPORT IN THE 850-700MB LEVEL INCREASES.
SAT-SUN:
BY SUNRISE SAT THE COLD FRONT IS EXPECTED TO STRETCH FROM NORTHEAST
KS INTO WEST-CENTRAL KS. WITH LACK OF STRONG/DEEP CONVERGENCE ALONG
THE FRONT...WOULD NOT BE SURPRISED TO SEE THE MORE WIDESPREAD PRECIP
BEHIND THE FRONT WHERE THE BETTER UPPER DYNAMICS WILL BE SITUATED.
WHILE CONFIDENCE IS HIGH THAT THERE WILL BE SOME SCATTERED ACTIVITY
NEAR THE FRONT AS IT PUSHES SOUTH ON SAT...HAVE LOW CONFIDENCE
ON HOW WIDESPREAD IT WILL BE. WITH SURFACE WINDS VEERING OUT AHEAD
OF THE FRONT...FEEL TEMPS COULD REALLY SOAR ACROSS SOUTH CENTRAL AND
ESPECIALLY SOUTHEAST KS. WOULD NOT BE SURPRISED TO SEE A FEW
LOCATIONS PUSH 110-111 ALONG THE KS-OK BORDER. WILL LET THE DAY
SHIFT MAKE THE CALL...BUT WOULD NOT BE SURPRISED IF THE CURRENT HEAT
HEADLINE WOULD NEED TO BE EXTENDED ANOTHER DAY.
BY SUNSET ON SAT THE FRONT SHOULD STRETCH ALONG THE KS-OK BORDER
WITH SOME SHOWERS AND STORMS ALONG AND JUST BEHIND THE FRONT.
CONFIDENCE IS HIGH THAT BY SUN MORNING THE PRECIP WILL BE SOUTH OF
THE FORECAST AREA.
MON-THU:
THROUGH THESE EXTENDED PERIODS THE UPPER RIDGE IS EXPECTED TO SHIFT
SLIGHTLY WEST WHICH WILL ALLOW THE FORECAST AREA TO REMAIN IN WEAK
DIFFLUENCE ALOFT. IN ADDITION BOTH THE ECMWF AND GFS ARE TRACKING
SOME SHORTWAVE ENERGY OUT OF THE NORTHERN ROCKIES AND ACROSS THE
MISSOURI VALLEY ON TUE NIGHT THROUGH WED. WILL KEEP SOME SMALL
PRECIP CHANCES FOR TUE NIGHT INTO WED WITH THE THINKING THAT THE
BEST CHANCES WOULD BE CLOSER TO THE UPPER DYNAMICS OVER NORTHEAST KS.
AS FAR AS TEMPS GO THROUGH THESE PERIODS...THEY WILL NOT BE AS
EXTREME AS SOUTHERN KS HAS SEEN OVER THE LAST SEVERAL DAYS...BUT
WILL STILL BE ABOVE NORMAL.
LAWSON
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
BOUNDARY HAS STARTED ITS SLOW MIGRATION NORTHWARD EVIDENCED BY
INCREASED THETA-E CONVERGENCE AND WINDS VEERING TO THE SOUTHEAST IN
NORTHERN OKLAHOMA. FURTHER PROOF OF THIS IS THE SHOWERS WITH
ISOLATED THUNDER FORMING OVER SOUTHEAST KANSAS AND BUILDING
TOWARDS SOUTH CENTRAL KANSAS. LATEST HRRR GUIDANCE HAS THIS
CONVECTION LINGERING FROM HUT TO ICT AND CNU THROUGH ABOUT 12-13Z.
THE FOCUS SHIFTS TO FRIDAY AFTERNOON WHERE A VORT LOBE IS PROGGED
TO MOVE OFF THE HIGH PLAINS. THIS MAY SPARK OFF SOME SHOWERS AND
STORMS NEAR RSL AND SLN TOWARDS THE END OF THE TAF PERIOD. SINCE
CONFIDENCE ON DEVELOPMENT AND TIMING ISN`T TOO GREAT...HAVE
DECIDED TO LEAVE MENTION OF SHRA AND VCTS OUT FOR THOSE AREAS FOR
THE MOMENT.
ARL
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 102 78 100 69 / 30 20 30 40
HUTCHINSON 100 76 96 66 / 40 20 30 30
NEWTON 101 77 97 66 / 30 20 30 30
ELDORADO 102 77 99 68 / 30 20 30 40
WINFIELD-KWLD 106 80 105 71 / 20 20 30 40
RUSSELL 98 73 90 63 / 40 40 30 10
GREAT BEND 99 74 92 65 / 50 30 30 10
SALINA 100 75 92 64 / 40 30 30 20
MCPHERSON 100 75 95 65 / 40 20 30 20
COFFEYVILLE 108 80 106 71 / 20 10 20 40
CHANUTE 102 78 103 70 / 30 10 20 40
IOLA 102 78 101 69 / 30 10 20 40
PARSONS-KPPF 104 79 105 71 / 30 10 20 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069-
082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
100 AM CDT FRI AUG 3 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1000 PM CDT THU AUG 2 2012
THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED THAT STRONGER JET FLOW WAS MAINLY
CONFINED TO THE NORTHERN HALF OF THE UNITED STATES AND INTO CANADA.
FLOW IN THIS REGION WAS GENERALLY GREATER THAN 50 KT. A FEW ~75 KT JET
STREAKS WERE NOTED ACROSS BRITISH COLUMBIA, NORTHERN MICHIGAN, AND QUEBEC.
ACROSS THE SOUTHERN HALF OF THE US, FLOW WAS GENERALLY LIGHT /15-30
KT/ WITH ANTICYCLONIC FLOW MOST PROMINENT ACROSS THE SOUTHERN PLAINS.
AT 500 HPA, A STRONG 562 DM CYCLONE WITH COLD -20 DEG C TEMPS WAS LOCATED
ACROSS CENTRAL ALBERTA. A SHORTWAVE TROUGH WAS MOVING ACROSS SOUTHEASTERN
CANADA. A STRONG 595 DM ANTICYCLONE WAS DOMINATE OVER WEST TEXAS WITH
RELATIVELY WARM /-5 TO -3 DEG C/ MID LEVEL TEMPERATURES. SOME MID LEVEL
MOISTURE WAS ADVECTING TO THE NORTHEAST AROUND SAID HIGH. AT 700 HPA,
THERE WAS ABOUT A 2 DEG C COOLING BETWEEN 00Z SYNOPTIC FLIGHTS ACROSS
KDDC COUNTRY. STILL, 700 HPA TEMPERATURES WERE STILL FAIRLY WARM ACROSS
THE CENTRAL AND SOUTHERN PLAINS WITH 13 TO 16 DEG C COMMONPLACE. THIS
COOLING /ALTHOUGH SOMEWHAT MORE SIGNIFICANT/ WAS ALSO NOTED AT 850 HPA,
ALTHOUGH TEMPS SOUTHWEST OF KDDC WERE STILL VERY WARM (IN THE 30S DEG
C). AT THE SFC, A FRONTAL BOUNDARY WAS LOCATED ACROSS OKLAHOMA. ANOTHER
FRONTAL SYSTEM WAS LOCATED ACROSS THE NORTHERN HIGH PLAINS. TROPICAL
STORM ERNESTO WAS LOCATED NEAR 13.4N 58.3W AT 03.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 100 AM CDT FRI AUG 3 2012
THIS MORNING:
FIRST CONCERN FOR THE SHORT TERM PERIOD IS OVERNIGHT CONVECTION. WAS
FAIRLY LIBERAL WITH POPS GIVEN RADAR TRENDS AND THE LATEST FORECAST
PROGRESSION FROM THE HRRR. THIS ACTIVITY WILL WEAKEN AS IT HEADS EAST
ACROSS THE REGION. THERE SHOULD BE A FAIR AMOUNT OF CLOUD DEBRIS FROM
THIS CONVECTION THROUGH THE NEXT 12 HOURS WHICH WILL HAVE IMPACTS ON
HIGH TEMPERATURES LATER ON.
TODAY:
MONSOONAL MOISTURE IS WORKING ITS WAY AROUND THE STRONG MID LEVEL ANTICYCLONE
TO OUR SOUTH. IN ADDITION, STRONGER FLOW ALOFT IS EXPECTED IN ASSOCIATION
WITH THE PASSAGE OF A SHORTWAVE TROUGH WELL TO OUR NORTH. CURRENTLY
THINK ANOTHER ROUND OF CONVECTION WILL BE LIKELY THIS AFTERNOON ACROSS
THE REGION. HAVE THE HIGHEST (CHANCE POPS) ACROSS THE NORTHWEST ZONES
WHERE BETTER LOW LEVEL CONVERGENCE AND UPPER LEVEL SUPPORT WILL BE.
ALSO HAVE GONE WITH THE COOLER SIDE OF MOS GUIDANCE IN ANTICIPATION
OF RESIDUAL CLOUD OVER FROM MORNING CONVECTION AND THEN ADDITIONAL CLOUD
DEVELOPMENT THIS AFTERNOON. WOULD NOT COMPLETELY RULE OUT SEVERE WEATHER
AS SBCAPE IS FORECAST TO BE AROUND 2000 J/KG AND 0-6 KM SHEAR FORECAST
TO BE 30-40 KT. WITH 700-500 HPA LAPSE RATES AROUND 7 DEG/KM, CANNOT
COMPLETELY RULE OUT AN ISOLATED SEVERE HAIL REPORT EITHER.
TONIGHT:
HAVE A CONCERN FOR OVERNIGHT CONVECTION AGAIN THIS EVENING BUT THE ACTIVITY
SHOULD BE TRENDING DOWNWARD OVERNIGHT. PWATS DO CLIMB TO THE 75TH PERCENTILE
SO THERE COULD BE HEAVY RAIN TONIGHT. MEANWHILE, AS THE AFOREMENTIONED
UPPER LEVEL SHORTWAVE TROUGH TRAVERSES EAST, THIS WILL USHER IN A COLD
FRONT BY SATURDAY MORNING. NORTHERLY WINDS MAY BECOME ON THE BREEZY
SIDE AS 850 HPA WINDS INCREASE TO AROUND 20-30 KT IN THE WAKE OF THE FRONT.
WILL GO WITH A BLEND OF THE 00Z NAM AND 00Z ALLBLEND WHICH HAS THE FRONT
BISECTING THE REGION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 234 PM CDT THU AUG 2 2012
NAM AND GFS INDICATING A 500MB VORT LOBE WILL EXIT COLORADO AND
CROSS WESTERN KANSAS FRIDAY NIGHT. GIVEN LATE DAY INSTABILITY AND
A SURFACE BOUNDARY IN/NEAR WESTERN KANSAS THERE STILL APPEARS TO
BE AT LEAST A SLIGHT CHANCE FOR A SOME THUNDERSTORMS EARLY. BY
SATURDAY MORNING THERE WILL BE ANOTHER CHANCE FOR THUNDERSTORMS
AGAIN BEHIND A COLD FRONT AS SURGES SOUTH ACROSS WESTERN KANSAS.
ALTHOUGH SOME TIMING ISSUES STILL EXIST WITH THE SURFACE FRONTAL
PASSAGE...ALL THE MODELS TEND TO AGREE THAT THIS FRONT WILL
UNDERCUT SOME WARM (+13 TO +15C) 700MB TEMPERATURES. AS A RESULT
PRECIPITATION CHANCES WITH THE FRONT STILL APPEARS SMALL. THE
BETTER OPPORTUNITY WILL BE POST FRONTAL BASED ON WHEN THE BETTER
UPPER LEVEL DYNAMICS CROSS THE CENTRAL PLAINS. AS A RESULT BASED
ON THE TIMING AND LOCATION OF AN UPPER LEVEL JET, AND MID LEVEL
MOISTURE/FORCING WILL INCREASE PRECIPITATION CHANCES AFTER 12Z
SATURDAY. PRECIPITATION SHOULD THEN BEGIN TO TAPER OFF FROM
NORTHWEST TO SOUTHEAST EARLY SATURDAY NIGHT AS THE UPPER TROUGH
CROSSES THE CENTRAL PLAINS AND BETTER MOISTURE NEAR THE 700MB
BAROCLINIC ZONE EXITS WESTERN KANSAS.
BY EARLY SUNDAY THE UPPER TROUGH WILL BEGIN TO MOVE INTO THE
MISSISSIPPI VALLEY AS ANTICYCLONIC FLOW DEVELOPS ACROSS THE
WESTERN ROCKIES AND A SURFACE HIGH SETTLES INTO THE CENTRAL
PLAINS. BEHIND THIS COLD FRONT THE 850MB TEMPERATURES COOL FROM
THE 30S AT 00Z SATURDAY TO THE 20S AT 00Z SUNDAY. 850MB
TEMPERATURES REMAIN IN THE 20S AT 00Z SUNDAY AS THE SURFACE HIGH
BUILDS ACROSS KANSAS. BASED ON THESE TEMPERATURE TRENDS AND THE
EXPECTED POSSIBLE CLOUD COVER/PRECIPITATION BEHIND THIS FRONT ON
SATURDAY THE PREVIOUS FORECAST STILL LOOKS REASONABLE. IF THE GFS
VERIFIES IT MAY EVEN END UP BEING SLIGHTLY COOLER IN WEST CENTRAL
AND NORTH CENTRAL KANSAS. ON SUNDAY THE HIGHS WILL BE SLIGHTLY
WARMER, ESPECIALLY IN THE WEST BUT STILL BASED ON 00Z MONDAY 850MB
MIX DOWN TEMPERATURES THE HIGHS ARE EXPECTED TO BE MAINLY IN THE
90S.
EARLY NEXT WEEK AN AREA OF HIGH PRESSURE AT THE SURFACE WILL
SLIDE EAST AND GIVE WAY TO A TROUGH OF LOW PRESSURE DEVELOPING
ALONG THE LEE OF THE ROCKIES. THE UPPER LEVEL RIDGE AXIS WILL BE
LOCATED NEAR THE ROCKIES WHICH WILL PLACE THE CENTRAL PLAINS IN A
WEAK NORTHWEST FLOW. A WARMING TREND IS EXPECTED EARLY IN THE WORK
WEEK BUT PRECIPITATION CHANCES AT LEAST THROUGH TUESDAY NIGHT
STILL APPEARS SMALL WITH THE POSSIBLE EXCEPTION OF A FEW HIGH
BASED CLOUDS/SHOWERS NEAR THE 700MB BAROCLINIC ZONE.
A COLD FRONT MID WEEK WILL DROP SOUTH INTO CENTRAL KANSAS AS
ANOTHER NORTHERN BRANCH UPPER LOW/TROUGH DROPS SOUTH OUT OF CANADA
INTO THE GREAT LAKES. THIS WILL BRING ANOTHER BRIEF BREAK IN THE
HEAT AS WELL AS A CHANCE FOR SCATTERED PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM CDT FRI AUG 3 2012
ATTENTION WAS PAID TO MAINLY TO THE FIRST 6 TO 9 HOURS OF THE TAF. FIRST
CONCERN IS CONVECTION THROUGH THE OVERNIGHT HOURS AS AN MCS PROPAGATES
EASTWARD ACROSS WESTERN KANSAS. HAVE USED RADAR TRENDS AND HRRR TO TIME
CB/TS GROUPS FOR THE TAFS. CONVECTION WILL BE POSSIBLE AGAIN LATER IN
THE TAF PERIOD, HOWEVER, WILL MAKE ADJUSTMENTS REGARDING OVERNIGHT CONVECTION
AND LATER TAF ISSUANCE CAN MODIFY TAFS AS 12Z DATA COMES IN FOR CONVECTION
LATER THIS AFTERNOON. GENERALLY CIGS SHOULD BE VFR THROUGH THE ENTIRE
TAF PERIOD. E TO SE WINDS AROUND 10 KT EXPECTED AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 93 63 92 / 40 40 20 10
GCK 70 88 62 91 / 50 30 20 10
EHA 69 88 64 91 / 50 40 30 10
LBL 71 92 67 92 / 40 40 30 10
HYS 71 90 61 92 / 40 40 10 0
P28 76 99 72 94 / 30 40 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT FRI AUG 3 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1000 PM CDT THU AUG 2 2012
THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED THAT STRONGER JET FLOW WAS MAINLY
CONFINED TO THE NORTHERN HALF OF THE UNITED STATES AND INTO CANADA.
FLOW IN THIS REGION WAS GENERALLY GREATER THAN 50 KT. A FEW ~75 KT JET
STREAKS WERE NOTED ACROSS BRITISH COLUMBIA, NORTHERN MICHIGAN, AND QUEBEC.
ACROSS THE SOUTHERN HALF OF THE US, FLOW WAS GENERALLY LIGHT /15-30
KT/ WITH ANTICYCLONIC FLOW MOST PROMINENT ACROSS THE SOUTHERN PLAINS.
AT 500 HPA, A STRONG 562 DM CYCLONE WITH COLD -20 DEG C TEMPS WAS LOCATED
ACROSS CENTRAL ALBERTA. A SHORTWAVE TROUGH WAS MOVING ACROSS SOUTHEASTERN
CANADA. A STRONG 595 DM ANTICYCLONE WAS DOMINATE OVER WEST TEXAS WITH
RELATIVELY WARM /-5 TO -3 DEG C/ MID LEVEL TEMPERATURES. SOME MID LEVEL
MOISTURE WAS ADVECTING TO THE NORTHEAST AROUND SAID HIGH. AT 700 HPA,
THERE WAS ABOUT A 2 DEG C COOLING BETWEEN 00Z SYNOPTIC FLIGHTS ACROSS
KDDC COUNTRY. STILL, 700 HPA TEMPERATURES WERE STILL FAIRLY WARM ACROSS
THE CENTRAL AND SOUTHERN PLAINS WITH 13 TO 16 DEG C COMMONPLACE. THIS
COOLING /ALTHOUGH SOMEWHAT MORE SIGNIFICANT/ WAS ALSO NOTED AT 850 HPA,
ALTHOUGH TEMPS SOUTHWEST OF KDDC WERE STILL VERY WARM (IN THE 30S DEG
C). AT THE SFC, A FRONTAL BOUNDARY WAS LOCATED ACROSS OKLAHOMA. ANOTHER
FRONTAL SYSTEM WAS LOCATED ACROSS THE NORTHERN HIGH PLAINS. TROPICAL
STORM ERNESTO WAS LOCATED NEAR 13.4N 58.3W AT 03.03Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 353 PM CDT THU AUG 2 2012
AN UPPER LEVEL RIDGE AXIS REMAINED ACROSS THE SOUTHERN PLAINS TODAY
AND WILL PERSIST THROUGH FRIDAY. OUTFLOW FROM OVERNIGHT CONVECTION
PUSHED INTO OKLAHOMA TODAY AND REMAINED THERE. EASTERLY UPSLOPE
FLOW RESULTED IN COOLER TEMPERATURES TODAY IN THE MID 90S TO
AROUND 103F ACROSS SOUTHWEST KANSAS.
A FEW THUNDERSTORMS COULD MOVE OUT OF COLORADO AND FAR WESTERN
KANSAS ALONG THE INTERSTATE 70 CORRIDOR TONIGHT. THIS ACTIVITY IS
NOT EXPECTED TO BE VERY WIDESPREAD IN THE ABSENCE OF ANY WELL DEFINED
UPPER-LEVEL FEATURE. LOW LEVEL MOISTURE WILL GRADUALLY INCREASE
ACROSS SOUTHWEST KANSAS THROUGH FRIDAY AS WEAK UPSLOPE FLOW
CONTINUES TO THE NORTH OF A WEAK FRONTAL BOUNDARY. THIS WILL
RESULT IN INCREASED SURFACE BASED CAPE VALUES TO AROUND 1000-1500
J/KG. MEANWHILE, A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN
ROCKIES BY FRIDAY AFTERNOON, WITH INCREASING UPPER LEVEL FLOW AS
FAR SOUTH AS KANSAS. WITH DAYTIME HEATING, INCREASING MOISTURE AND
WEAK CAPPING, SOME AFTERNOON THUNDERSTORMS ARE POSSIBLE ONCE
AGAIN. HIGHS MAY BE HELD DOWN A FEW DEGREES BY AFTERNOON
CONVECTIVE INITIATION IN FAR WESTERN KANSAS AND THE RESULTANT
CIRRIFORM BLOW OFF. NEVERTHELESS, TEMPERATURES SHOULD REACH AT
LEAST AS HIGH AS TODAY`S NUMBERS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 234 PM CDT THU AUG 2 2012
NAM AND GFS INDICATING A 500MB VORT LOBE WILL EXIT COLORADO AND
CROSS WESTERN KANSAS FRIDAY NIGHT. GIVEN LATE DAY INSTABILITY AND
A SURFACE BOUNDARY IN/NEAR WESTERN KANSAS THERE STILL APPEARS TO
BE AT LEAST A SLIGHT CHANCE FOR A SOME THUNDERSTORMS EARLY. BY
SATURDAY MORNING THERE WILL BE ANOTHER CHANCE FOR THUNDERSTORMS
AGAIN BEHIND A COLD FRONT AS SURGES SOUTH ACROSS WESTERN KANSAS.
ALTHOUGH SOME TIMING ISSUES STILL EXIST WITH THE SURFACE FRONTAL
PASSAGE...ALL THE MODELS TEND TO AGREE THAT THIS FRONT WILL
UNDERCUT SOME WARM (+13 TO +15C) 700MB TEMPERATURES. AS A RESULT
PRECIPITATION CHANCES WITH THE FRONT STILL APPEARS SMALL. THE
BETTER OPPORTUNITY WILL BE POST FRONTAL BASED ON WHEN THE BETTER
UPPER LEVEL DYNAMICS CROSS THE CENTRAL PLAINS. AS A RESULT BASED
ON THE TIMING AND LOCATION OF AN UPPER LEVEL JET, AND MID LEVEL
MOISTURE/FORCING WILL INCREASE PRECIPITATION CHANCES AFTER 12Z
SATURDAY. PRECIPITATION SHOULD THEN BEGIN TO TAPER OFF FROM
NORTHWEST TO SOUTHEAST EARLY SATURDAY NIGHT AS THE UPPER TROUGH
CROSSES THE CENTRAL PLAINS AND BETTER MOISTURE NEAR THE 700MB
BAROCLINIC ZONE EXITS WESTERN KANSAS.
BY EARLY SUNDAY THE UPPER TROUGH WILL BEGIN TO MOVE INTO THE
MISSISSIPPI VALLEY AS ANTICYCLONIC FLOW DEVELOPS ACROSS THE
WESTERN ROCKIES AND A SURFACE HIGH SETTLES INTO THE CENTRAL
PLAINS. BEHIND THIS COLD FRONT THE 850MB TEMPERATURES COOL FROM
THE 30S AT 00Z SATURDAY TO THE 20S AT 00Z SUNDAY. 850MB
TEMPERATURES REMAIN IN THE 20S AT 00Z SUNDAY AS THE SURFACE HIGH
BUILDS ACROSS KANSAS. BASED ON THESE TEMPERATURE TRENDS AND THE
EXPECTED POSSIBLE CLOUD COVER/PRECIPITATION BEHIND THIS FRONT ON
SATURDAY THE PREVIOUS FORECAST STILL LOOKS REASONABLE. IF THE GFS
VERIFIES IT MAY EVEN END UP BEING SLIGHTLY COOLER IN WEST CENTRAL
AND NORTH CENTRAL KANSAS. ON SUNDAY THE HIGHS WILL BE SLIGHTLY
WARMER, ESPECIALLY IN THE WEST BUT STILL BASED ON 00Z MONDAY 850MB
MIX DOWN TEMPERATURES THE HIGHS ARE EXPECTED TO BE MAINLY IN THE
90S.
EARLY NEXT WEEK AN AREA OF HIGH PRESSURE AT THE SURFACE WILL
SLIDE EAST AND GIVE WAY TO A TROUGH OF LOW PRESSURE DEVELOPING
ALONG THE LEE OF THE ROCKIES. THE UPPER LEVEL RIDGE AXIS WILL BE
LOCATED NEAR THE ROCKIES WHICH WILL PLACE THE CENTRAL PLAINS IN A
WEAK NORTHWEST FLOW. A WARMING TREND IS EXPECTED EARLY IN THE WORK
WEEK BUT PRECIPITATION CHANCES AT LEAST THROUGH TUESDAY NIGHT
STILL APPEARS SMALL WITH THE POSSIBLE EXCEPTION OF A FEW HIGH
BASED CLOUDS/SHOWERS NEAR THE 700MB BAROCLINIC ZONE.
A COLD FRONT MID WEEK WILL DROP SOUTH INTO CENTRAL KANSAS AS
ANOTHER NORTHERN BRANCH UPPER LOW/TROUGH DROPS SOUTH OUT OF CANADA
INTO THE GREAT LAKES. THIS WILL BRING ANOTHER BRIEF BREAK IN THE
HEAT AS WELL AS A CHANCE FOR SCATTERED PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM CDT FRI AUG 3 2012
ATTENTION WAS PAID TO MAINLY TO THE FIRST 6 TO 9 HOURS OF THE TAF. FIRST
CONCERN IS CONVECTION THROUGH THE OVERNIGHT HOURS AS AN MCS PROPAGATES
EASTWARD ACROSS WESTERN KANSAS. HAVE USED RADAR TRENDS AND HRRR TO TIME
CB/TS GROUPS FOR THE TAFS. CONVECTION WILL BE POSSIBLE AGAIN LATER IN
THE TAF PERIOD, HOWEVER, WILL MAKE ADJUSTMENTS REGARDING OVERNIGHT CONVECTION
AND LATER TAF ISSUANCE CAN MODIFY TAFS AS 12Z DATA COMES IN FOR CONVECTION
LATER THIS AFTERNOON. GENERALLY CIGS SHOULD BE VFR THROUGH THE ENTIRE
TAF PERIOD. E TO SE WINDS AROUND 10 KT EXPECTED AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 98 72 93 / 40 40 40 40
GCK 69 95 70 88 / 50 40 50 30
EHA 69 95 69 88 / 60 40 50 40
LBL 70 97 71 92 / 50 40 40 40
HYS 70 96 71 90 / 40 40 40 40
P28 75 104 76 99 / 30 30 30 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1146 PM CDT THU AUG 2 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
BOUNDARY HAS STARTED ITS SLOW MIGRATION NORTHWARD EVIDENCED BY
INCREASED THETA-E CONVERGENCE AND WINDS VEERING TO THE SOUTHEAST IN
NORTHERN OKLAHOMA. FURTHER PROOF OF THIS IS THE SHOWERS WITH
ISOLATED THUNDER FORMING OVER SOUTHEAST KANSAS AND BUILDING
TOWARDS SOUTH CENTRAL KANSAS. LATEST HRRR GUIDANCE HAS THIS
CONVECTION LINGERING FROM HUT TO ICT AND CNU THROUGH ABOUT 12-13Z.
THE FOCUS SHIFTS TO FRIDAY AFTERNOON WHERE A VORT LOBE IS PROGGED
TO MOVE OFF THE HIGH PLAINS. THIS MAY SPARK OFF SOME SHOWERS AND
STORMS NEAR RSL AND SLN TOWARDS THE END OF THE TAF PERIOD. SINCE
CONFIDENCE ON DEVELOPMENT AND TIMING ISN`T TOO GREAT...HAVE
DECIDED TO LEAVE MENTION OF SHRA AND VCTS OUT FOR THOSE AREAS FOR
THE MOMENT.
&&
ARL
.PREV DISCUSSION... /ISSUED 844 PM CDT THU AUG 2 2012/
UPDATE...
TRENDED DOWN POPS A LITTLE BETWEEN NOW AND 6Z GIVEN RECENT RADAR
AND SATELLITE TRENDS FOR AT LEAST THE CENTRAL PART OF THE CWA.
BOUNDARY IS STILL LOCATED IN NORTHERN OKLAHOMA WITH SOME CU AND
WIDELY SCATTERED STORMS DEVELOPING. THE BOUNDARY IS STILL PROGGED
TO SLOWLY MOVE NORTH INTO SOUTHERN KANSAS THROUGHOUT TONIGHT.
MOISTURE ADVECTION ISN`T VERY DESIRABLE AND A SIGNIFICANT SOURCE
OF LIFT IS LACKING...BUT STILL CANNOT RULE OUT SOME HIT OR MISS
ELEVATED SHOWERS ON THIS BOUNDARY DURING THE OVERNIGHT HOURS.
ARL
PREV DISCUSSION... /ISSUED 647 PM CDT THU AUG 2 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MONSOONAL MOISTURE CONTINUES TO RIDE UP AND OVER THE RIDGE
CENTERED OVER EASTERN NEW MEXICO AT THIS TIME. WIDELY SCATTERED
STORMS ARE UNDERWAY OVER THE HIGH PLAINS AND ARE VERY SLOWLY
DRIFING EAST. LATEST GUIDANCE KICKS OFF MORE CONVECTION ALONG LAST
NIGHT`S OUTFLOW BOUNDARY/850MB BAROCLINIC ZONE...BUT KEEPS IT
SOUTH OF THE OKLAHOMA BORDER FOR THE MOST PART. THIS IS CONFIRMED
BY A LITTLE CU DEVELOPMENT OVER NORTHERN OKLAHOMA RIGHT NOW.
ALSO...LATEST HRRR TENDS TO FIZZLE OUT THE CURRENT CONVECTION OVER
WESTERN KANSAS...BUT BRINGS IN ANOTHER ROUND OVERNIGHT AROUND
9-12Z. CONFIDENCE IS STILL LOW...BUT A HINT OF A MID LEVEL WAVE
ON WATER VAPOR MEANS SOME UPPER SUPPORT MAY ACCOMPANY THIS
DEVELOPMENT...AND DECIDED TO ADD SOME VCSH TO RSL AND SLN FOR JUST
A FEW PREDAWN HOURS. WILL CONTINUE TO MONITOR ONGOING CONVECTION
TO OUR WEST AND DEVELOPMENT TO OUR SOUTH...AND WILL LOOK AT 00Z
MODEL RUNS TO DETERMINE CHANCES FOR PRECIPITATION AT THE OTHER
SITES OVERNIGHT. IN THE MEAN TIME VFR CONDITIONS WILL DOMINATE.
ARL
PREV DISCUSSION... /ISSUED 332 PM CDT THU AUG 2 2012/
DISCUSSION...
TONIGHT...LIKE THE PAST FEW NIGHTS...CANNOT RULE OUT A FEW
THUNDERSTORMS AFTER MIDNIGHT ACROSS THE REGION...AS WEAK MONSOONAL
ENERGY TOPS STOUT UPPER RIDGE AND APPROACHES FROM THE WEST.
WONDERING IF BETTER CHANCES TONIGHT WILL BE GENERALLY SOUTH OF
I-70...ALONG/NORTH OF 850-700MB BOUNDARY...AND ALSO WITHIN HIGHEST
PRECIPITABLE WATER AXIS. WIDESPREAD RELIEF APPEARS
UNLIKELY...ALTHOUGH A FEW LOCATIONS COULD PICK UP A QUARTER INCH OR
SO.
FRIDAY TEMPERATURES...WITH THE POTENTIAL FOR ANOTHER OUTFLOW
BOUNDARY FROM OVERNIGHT CONVECTION...TEMPERATURES WILL ONCE AGAIN BE
TRICKY. HOWEVER...DO THINK AT LEAST SOUTHERN KANSAS TEMPERATURES
WILL SOAR WELL INTO THE 100S...SO WENT AHEAD AND EXTENDED CURRENT
EXCESSIVE HEAT WARNING THROUGH FRIDAY GENERALLY SOUTH OF HIGHWAY 54.
DEPENDING ON HOW CONVECTION EVOLVES TONIGHT...NIGHT SHIFT MAY NEED
TO EXTEND THIS HEADLINE A TAD FURTHER NORTH.
FRIDAY-SATURDAY...A FEW SHOWERS/THUNDERSTORMS MAY LINGER OVER THE
AREA INTO THE FRIDAY MORNING HOURS. OTHERWISE...WITH BOUNDARY
REMAINING IN PLACE...CANNOT RULE OUT A STRAY LATE AFTERNOON/EVENING
THUNDERSTORM OVER FAR SOUTHERN KS. SOMEWHAT BETTER CHANCES MAY
ARRIVE LATE FRIDAY NIGHT OVER CENTRAL KS...AS A STRONG COLD FRONT
APPROACHES FROM THE NORTHWEST. THE BEST THUNDERSTORM CHANCES SHOULD
BE ALONG THE COLD FRONT SATURDAY AFTERNOON-NIGHT OVER MAINLY
SOUTHERN KANSAS. DESPITE MARGINAL INSTABILITY AND BEST UPPER FORCING
REMAINING NORTH OF THE REGION...THINKING FRONTAL FORCING WILL BE
ENOUGH FOR AT LEAST WIDELY SCATTERED STORMS. PROBABLY NOT A
WIDESPREAD HEAVY RAINFALL EVENT...BUT PROBABLY AT LEAST SOME MODEST
RELIEF. WIDESPREAD SEVERE WEATHER APPEARS UNLIKELY...ALTHOUGH
ISOLATED STRONG/SEVERE WILL BE POSSIBLE.
SUNDAY...MODEST TEMPERATURE RELIEF IN WAKE OF THE COLD FRONT
EXPECTED...WITH HIGHS IN THE 90S ALL AREAS.
MONDAY-THURSDAY...MEDIUM RANGE GUIDANCE AND ASSOCIATED GFS ENSEMBLES
SUGGEST UPPER RIDGE WILL RETROGRADE WEST A BIT FOR NEXT WEEK KEEPING
NORTHWEST FLOW ALOFT ACROSS THE REGION. CONSEQUENTLY...WHILE ABOVE
NORMAL TEMPERATURES ARE STILL ANTICIPATED...CONFIDENCE IS INCREASING
THAT NEXT WEEK WILL ONLY BE IN THE 90S TO MAYBE LOW 100S.
ADDITIONALLY...NORTHWEST FLOW ALOFT BODES WELL FOR PERIODIC
PRECIPITATION CHANCES...AS AFTERNOON WESTERN HIGH PLAINS
THUNDERSTORM ACTIVITY ROLLS SOUTHEAST ALONG EASTERN EDGE OF WARM
850-700MB THERMAL RIDGE DURING THE EVENING AND NIGHTTIME HOURS.
HOWEVER...LEFT FORECAST DRY FOR NOW TO WAIT FOR BETTER RUN-TO-RUN
CONSISTENCY.
KLEINSASSER
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH
CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR
ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS
AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR
TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT
INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER
AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO
LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE
CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN
TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 105 76 105 78 / 20 30 10 10
HUTCHINSON 103 74 103 76 / 20 30 10 20
NEWTON 103 74 103 77 / 20 30 10 10
ELDORADO 103 74 104 78 / 20 30 10 10
WINFIELD-KWLD 109 78 107 80 / 20 30 10 10
RUSSELL 98 73 102 73 / 20 30 10 30
GREAT BEND 100 73 102 74 / 20 30 10 30
SALINA 98 73 102 75 / 20 30 10 30
MCPHERSON 101 73 103 76 / 20 30 10 20
COFFEYVILLE 110 77 107 79 / 20 30 10 10
CHANUTE 105 74 103 79 / 20 30 10 10
IOLA 103 75 102 79 / 20 30 10 10
PARSONS-KPPF 107 75 105 79 / 20 30 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT FRIDAY FOR KSZ069-082-083-
091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
314 AM CDT FRI AUG 3 2012
.DISCUSSION...
CONVECTION MOVING THROUGH NORTH CENTRAL NEBRASKA WILL LIKELY BE
ONGOING ACROSS NORTHEAST NEBRASKA THIS MORNING...AT LEAST FOR AN
HOUR OR TWO...PROBABLY REMAINING JUST NORTH OF NORFOLK. OTHERWISE...
CONVECTION THAT FIRED YESTERDAY EVENING HAS SENT SOME CIRRUS OVER
THE FORECAST AREA...WITH ADDITIONAL BLOWOFF EXPECTED FROM ONGOING
CONVECTION ACROSS WESTERN KANSAS. THIS MAKES THE HIGH TEMPERATURE
FORECAST SLIGHTLY CHALLENGING TODAY...BUT FEEL WE SHOULD STILL HIT
THE UPPER 90S. THE MAJORITY OF THE FORECAST ALSO REMAINS DRY
TODAY...AND ADVANCE OF A COLD FRONT THAT IS EXPECTED TO MOVE
THROUGH THE FORECAST AREA TONIGHT. THE EXCEPTION WILL BE NORTHEAST
NEBRASKA...WHICH SHOULD SEE INCREASING CHANCES FOR STORMS BY VERY
LATE THIS AFTERNOON.
BETTER CHANCE FOR CONVECTION COMES THIS EVENING IN NORTHEAST
NEBRASKA WHEN THUNDERSTORMS SHOULD BECOME LIKELY IN THAT
AREA...PROBABLY NOT MAKING PROGRESS TOWARD THE I80 CORRIDOR UNTIL
AFTER MIDNIGHT. MEANWHILE...SPOTTY CONVECTION COULD MOVE OUT OF
NORTHEAST KANSAS INTO THE FAR SOUTHERN FORECAST AREA BY DAYBREAK
SATURDAY...SO AREAS SOUTH OF I80 COULD STILL SEE SMALL CHANCE OF
RAIN LATE FRIDAY NIGHT.
FOR SATURDAY...THE MAIN FRONT WILL CONTINUE TO PUSH SOUTH OF THE
REGION. HOWEVER...A SECONDARY AREA OF LIFT BEHIND THE FRONT WILL
BRING A DECENT CHANCE FOR ADDITIONAL SHOWERS AND THUNDERSTORMS
THAT SHOULD MOVE THROUGH THE FORECAST AREA...ALONG WITH BREEZY
NORTHWEST TO NORTHERLY WINDS. TEMPERATURE FORECAST IS SOMEWHAT
TRICKY SATURDAY...GIVEN COOLER READINGS BEHIND THE FRONT...ABUNDANT
CLOUD CLOVER WITHIN THE SHOWERS....POTENTIAL FOR CLEARING BEHIND
THE FRONT...AND ANY WARMING THAT CAN TAKE PLACE AHEAD OF THE
RAINFALL. LOWER TO MID 80S...WITH THE LOWER END OF THE RANGE ALONG
I80.
DRY WEATHER THEN CONTINUES FOR SUNDAY AND MONDAY WITH MUCH MORE
SEASONABLE TEMPERATURES ALONG WITH LOWER HUMIDITY. BY TUESDAY
NIGHT AND BEYOND...FORECAST AREA REMAINS IN NORTHWESTERLY
FLOW...WITH A FEW CHANCES FOR PRECIPITATION AS SUBTLE WAVES MOVE
ACROSS THE AREA.
DEWALD
&&
.AVIATION...06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS SHOULD PREVAIL THROUGH THE NEXT 24 HOURS. MID AND
HIGH LEVEL MOISTURE WILL SPREAD OVER THE TAF SITES DURING NIGHT.
TSRA CURRENTLY MOVING E/SE ACROSS SOUTHERN SD COULD APPROACH KOFK
LATE TONIGHT...BUT 01Z RUN OF HRRR MODEL SHOWED THESE WEAKENING
TOWARD SUNRISE. WINDS WILL TURN TO THE SOUTH/SOUTHEAST AND
INCREASE ON FRIDAY...AHEAD OF THE NEXT COLD FRONT.
THUNDERSTORMS COULD AFFECT PARTS OF NORTHEAST NEBRASKA BY FRIDAY
EVENING. DID NOT INCLUDE WITH THIS ISSUANCE...BUT MENTION OF TSRA
MAY BE NEEDED AT KOFK AFTER 00Z SATURDAY.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1222 AM CDT FRI AUG 3 2012
.AVIATION...06Z TAF. THUNDERSTORMS TO THE WEST HAVE ALLOWED FOR
SOME HIGH CLOUDS TO MOVE ACROSS THE KGRI TERMINAL EARLY THIS
MORNING. THE THUNDERSTORMS HAVE SINCE DIED OFF AND EXPECT DRY
CONDITIONS THROUGH THE NIGHT. THE SURFACE GRADIENT TIGHTENS DURING
THE DAY ON FRIDAY AND ALLOWS FOR WINDS FROM THE SOUTH TO INCREASE
SOME. DURING THE EVENING HOURS ON FRIDAY A COLD FRONT APPROACHES
AND WITH IT THERE ARE SOME THUNDERSTORMS POSSIBLE LATE IN THE
PERIOD. SINCE IT IS A BROAD LOW PRESSURE SYSTEM AND FRONT THE
WINDS WILL BE LIGHT AND TURN VERY GRADUALLY.
&&
.PREV DISCUSSION... /ISSUED 333 PM CDT THU AUG 2 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY AFTERNOON. CONCERN IN THE NEXT
24 HRS WILL BE SLIGHT CHANCES FOR TSTMS EARLY ON ALONG WITH HIGH
TEMPERATURES FOR FRIDAY.
CURRENT WATER VAPOR IMAGERY ALONG WITH UPPER AIR AND WIND PROFILER
DATA SHOW UPPER RIDGE NOW ANCHORED OVER TEXAS...AN UPPER LOW
DROPPING SSE AND INTO THE WESTERN PART OF ALBERTA...PUTTING THE
PLAINS IN WESTERLY FLOW. ONE CAN ALSO SEE THE SUBTROPICAL MOISTURE
TAP STREAMING NORTH ACROSS WESTERN MEXICO...INTO THE FOUR CORNERS
REGION AND THEN SWINGING EAST AROUND THE HIGH ACROSS OUR REGION.
AT THE SURFACE...PRESSURE GRADIENT VERY WEAK ACROSS NEB/KS WITH ONE
WEAK SURFACE LOW OVER OKLAHOMA AND ANOTHER ONE SITUATED ACROSS
EASTERN MT/WY. SURFACE DEWPOINTS REMAIN FAIRLY HIGH OVER THE CWA
RANGING FROM THE MID TO UPPER 60S AT LUNCHTIME. WEAK CONVECTIVE
ACTIVITY HAS NEVER QUITE FADED AWAY IN OUR KS CWA ALTHOUGH DOUBT
ANYTHING IS REACHING THE GROUND. CLOUD COVER ACROSS OUR SOUTHERN CWA
HAS BEEN HOLDING IN A LITTLE LONGER THAN ANTICIPATED AND WITH SOME
RE-DEVELOPMENT TO THE WEST...MAY NOT SEE HIGHS QUITE AS WARM AS
EXPECT. ALSO WEAK CELLS MOVING ACROSS NORTHERN NEBRASKA HAVE ALSO
HUNG IN DURING THE DAY. SOME OF THE HOURLY HRRR MODEL RUNS HAVE
SHOWN THIS HANGING TOGETHER AND MOVING INTO THE WESTERN PART OF THE
CWA LATER THIS AFTERNOON. WILL NEED TO MONITOR THIS OVER THE NEXT
FEW HOURS.
BELIEVE OUR BETTER...ALTHOUGH NOT GREAT...CHANCES FOR RAIN WILL BE
LATER THIS EVENING AND OVERNIGHT. CHECKING OUT THE NEEDED
INGREDIENTS...WE HAVE ADEQUATE INSTABILITY...MOISTURE AND SHEAR AT
PRESENT BUT SEEM TO BE LACKING A FORCING MECHANISM. BELIEVE THE
SURFACE TROUGH ALONG THE FRONT RANGE MAY FIT THE BILL AND WILL
MONITOR CONVECTIVE DEVELOPMENT OUT WEST LATER THIS AFTERNOON.
QUESTION THEN BECOMES WILL THIS ACTIVITY MAKE IT FAR ENOUGH EAST TO
AFFECT OUR CWA. EARLY LOOK AT HRRR SHOWS THIS IS POSSIBLE AND WILL
CHECK OUT THE 4KM WRF WHEN IT ARRIVES. SEEMS LIKE BETTER LOW LEVEL
JET REMAINS WEST OVERNIGHT.
ON FRIDAY AFTERNOON...THE UPPER LOW NOTED ABOVE WILL SHOULD BE
CENTERED SOMEWHERE NEAR THE MT/NDAK/CANADA BORDER. THIS IS A DECENT
WAVE AND SHOULD PROVIDE GOOD HEIGHT FALLS AND COOLER TEMPS ALOFT TO
THE NORTHERN PLAINS. IT WILL ALSO PUSH A COLD FRONT INTO OUR NW CWA
BY LATE AFTN OR EARLY EVENING. EXPECT SOME COMPRESSIONAL HEATING
AHEAD OF THE FRONT AND WITH SURFACE WINDS BECOMING SOUTH TO SSW
ANOTHER HOT DAY WILL BE IN STORE. DO NOT PLAN ON ISSUING ANY HEAT
HEADLINES AS APPARENT TEMPERATURE VALUES FORECAST TO BE BETWEEN 98
AND 102 DEGREES IN THE SOUTHERN CWA. NOT SURE IF CONVECTION WILL
BREAK OUT LATE FRIDAY AFTERNOON OR HOLD OFF UNTIL THE EVENING AS
MOST MODELS SHOWING THE BULK OF THE PRECIPITATION BEING POST
FRONTAL. IF I DO PUT IN AFTERNOON POPS...IT WILL MAINLY BE IN THE
NORTHWEST AND WEST PART OF THE CWA.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
CONCERNS FOR THE MID AND LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR THUNDERSTORMS AS WELL AS COOLER TEMPERATURES FOR THE
WEEKEND.
BEGINNING THE MID TERM PERIOD...THE MODELS REMAIN IN FAIRLY
CONSISTENT AGREEMENT AS THE UPPER LEVEL LOW CONTINUES TO SHIFT
EASTWARD ACROSS PORTIONS OF MONTANA AND NORTH DAKOTA. AT THE
SURFACE...A LARGE AREA OF LOW PRESSURE ALSO CONTINUES TO PUSH
EASTWARD...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY KNOCKING ON OUR
DOORSTEP BY FRIDAY EVENING. THUNDERSTORM CHANCES CONTINUE INTO THE
OVERNIGHT HOURS...WITH THE POSSIBILITY OF A FEW STRONG STORMS IN THE
EARLY EVENING. BY LATE SATURDAY MORNING...THE FRONTAL BOUNDARY
SHOULD BEGIN TO SAG SOUTHEAST OUT OF THE REGION WITH LINGERING
SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG THE ELEVATED
BOUNDARY. WITH FRONTAL PASSAGE OVERNIGHT FRIDAY...HIGH PRESSURE AND
COOLER TEMPERATURES WILL SINK INTO THE REGION ALONG WITH NORTH
WINDS. MUCH COOLER 850 TEMPERATURES ON THE ORDER OF 10 DEGREES
COOLER THAN PREVIOUS DAYS WILL HELP DRASTICALLY REDUCE HIGH
TEMPERATURES. A VERY NICE WEEKEND IS IN STORE WITH HIGHS IN THE MID
TO UPPER 80S.
BY THE BEGINNING OF THE WORKWEEK...THE UPPER LEVEL RIDGE WILL BEGIN
TO BUILD BACK IN ACROSS THE ROCKIES...RESULTING IN NORTHWEST FLOW
THROUGH THE EXTENDED PERIOD. A DRY FORECAST IS EXPECTED THROUGH THE
BEGINNING OF THE WORKWEEK AS THE CENTRAL PLAINS REMAIN UNDER SURFACE
HIGH PRESSURE.
HOWEVER...TOWARDS THE END OF THE PERIOD...A FEW SHORT WAVE
PERTURBATIONS ROUND THE EASTERN EDGE OF THE UPPER LEVEL RIDGE...AND
COMBINED WITH A SURFACE TROUGH AXIS ALONG THE FRONT RANGE WILL HELP
GENERATE SOME CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
EXTENDED. CONTINUED SLIGHT CHANCES THROUGH THE PERIOD...MONDAY AND
AGAIN TUESDAY NIGHT THROUGH WEDNESDAY.
AS FOR TEMPERATURES...ALTHOUGH MUCH OF THE WARMER 850 TEMPERATURES
REMAIN FARTHER WEST ACROSS THE ROCKIES...EXPECT A RISE IN
TEMPERATURES THROUGH THE WORKWEEK. CONTINUED WITH HIGHS IN THE MID
TO UPPER 90S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1140 PM CDT THU AUG 2 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS SHOULD PREVAIL THROUGH THE NEXT 24 HOURS. MID AND
HIGH LEVEL MOISTURE WILL SPREAD OVER THE TAF SITES DURING NIGHT.
TSRA CURRENTLY MOVING E/SE ACROSS SOUTHERN SD COULD APPROACH KOFK
LATE TONIGHT...BUT 01Z RUN OF HRRR MODEL SHOWED THESE WEAKENING
TOWARD SUNRISE. WINDS WILL TURN TO THE SOUTH/SOUTHEAST AND
INCREASE ON FRIDAY...AHEAD OF THE NEXT COLD FRONT.
THUNDERSTORMS COULD AFFECT PARTS OF NORTHEAST NEBRASKA BY FRIDAY
EVENING. DID NOT INCLUDE WITH THIS ISSUANCE...BUT MENTION OF TSRA
MAY BE NEEDED AT KOFK AFTER 00Z SATURDAY.
MILLER
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT THU AUG 2 2012/
DISCUSSION...
SYNOPSIS...12Z UPPER AIR ANALYSIS INDCD NEXT MAIN SYSTEM OF
INTERESTED WAS DIVING SEWD THROUGH AB AND BC ASSOCIATED WITH AN
90 KT H3 JET AND 70 M H5 HEIGHT FALLS. DOWNSTREAM FM THAT
SYSTEM...A WEAK SHRTWV TROF WAS NOTED OVER MN ASSOCIATED WITH A
COOL FNT AT H85 FM MN INTO ERN NEB. 19Z SFC ANLYS INDCD 1008 MB
LOW PRESSURE OVER SRN IA WITH CDFNT FM NRN MO INTO SRN KS.
FORECAST...THE MAIN STORY OVER THE NEXT 36 HRS WILL BE THE EFFECTS
OF THE CANADIAN SYSTEM AS IT DROPS INTO THE CNTRL US. FOR TONIGHT
WEAK SURFACE HIGH PRESSURE WILL CROSS THE AREA THIS EVENING WITH
AFTN CU FIELD GIVING WAY TO MOSTLY CLEAR SKIES. LOW LEVEL WAA OVER
THE HIGH PLAINS WILL SHIFT EWD INTO NRN NEB AFTER MIDNIGHT AND MAY
ALLOW FOR AN ISOLATED SHOWER TO CLIP OUR FAR NW FA AND LEFT A
SCHC POP THERE. SFC WINDS WILL TURN S/SE ON FRI AHEAD OF THE
STRONG CDFNT AND ASSOCIATED UPPER LEVEL SYSTEM. NAM CERTAINLY
MIXES OUT OUR BOUNDARY LAYER TO MUCH...BUT GIVEN 850 TMPS OFF THE
NAM/GFS...HIGHS SHOULD CLIMB TO AROUND 100 ON FRI AFTN. ALTHOUGH
THE ATMOSPHERE WILL BE STRONGLY CAPPED ON FRI AS ELEVATED MIXED
LAYER /SEEN IN THE +14 C H7 TMPS/ SPREADS OVER THE
FA...CONVERGENCE ALONG THE COLD FRONT AND SOME UPPER LEVEL SUPPORT
ASSOCIATED WITH IN THE INCOMING JET SHOULD ALLOW FOR SCT TSRA TO
DVLP FM ERN SD INTO NRN NEB...AND THESE WILL MAKE A PUSH TOWARD
AREA NW FA ON FRI EVNG WITH HIGH CHC POPS WARRANTED. AS WAS THE
CASE LAST NIGHT...THESE STORMS WILL LOSE SOME INTENSITY WITH THE
COOLING BOUNDARY LAYER AND LOSS OF UPPER LEVEL SUPPORT THE FURTHER
S THEY PUSH...AND THUS THE CNTRL AND SRN CWA HAVE A MUCH LOWER CHC
OF SEEING RAINFALL. THE SFC CDFNT WILL PUSH THRU THE SRN CWA ON
SAT MRNG WITH CAA KICKING IN FOR THE REST OF SAT. AT THE SAME TIME
THE MAIN UPPER LEVEL TROUGH WILL BE PUSHING THRU SD WITH DECENT
DPVA INDICATED IN THE MODELS ALONG WITH STRONG H7 FRONTOGENESIS.
THIS SHOULD LEAD TO A FEW SHOWERS THROUGH THE MRNG...AND MAYBE
EARLY AFTERNOON OVER NRN CWA AS THE FORCING MOVES THROUGH.
OTHERWISE THERE MAY BE A TSRA OR TWO DEVELOP NEAR OR SLIGHTLY
BEHIND THE FNT OVER FAR SE NEB/SW IA ON SAT AFTN. OTHERWISE WITH
THE CAA AND SOME CLOUDS WE ARE EXPECTING MUCH COOLER HIGHS ON SAT!
EXTENDED...THE COOLER AND DRY WEATHER WILL CONT FOR SUN/MON WITH
HIGHS IN THE 80S AND LOWS IN THE 60S...BEFORE A WARMING TREND
GETS GOING WITH HIGHS BACK INTO THE 90S FOR TUE-THU. MODELS SEEM
FAIRLY CONSISTENT ON TAKING A SHORTWAVE TROUGH OVER THE RIDGE ON
TUE NIGHT/WE AND WE HAVE SOME CHC POPS GOING FOR THIS PERIOD.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TULSA OK
1151 PM CDT THU AUG 2 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... SHOWERS AND THUNDERSTORMS ARE CURRENTLY TRACKING
SOUTHEASTWARD ACROSS A PORTION OF FAR NORTHEAST OKLAHOMA AND
NORTHWEST ARKANSAS. HAVE VCTS IN KXNA AND KFYV TAFS UNTIL 9Z FOR
THIS ACTIVITY. OTHERWISE... VFR CONDITIONS WILL PREVAIL AT ALL TAF
SITES THROUGH THE ENTIRE 24 HOUR FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 931 PM CDT THU AUG 2 2012/
..UPDATE...
DISCUSSION...
WELL DEFINED OUTFLOW BOUNDARY HAS PUSHED TO NEAR A PAWNEE TO JAY
LINE...AND CONTINUES TO SLOWLY WORK SOUTHWARD. ISOLATED CONVECTION
HAS RECENTLY FIRED ALONG THE BOUNDARY BOTH ACROSS NE OK / NW AR
BUT ALSO FURTHER WEST ACROSS NW OK. WILL MAINTAIN LOW PRECIP
CHANCES OVERNIGHT THOUGH COVERAGE WILL LIKELY REMAIN RATHER LOW.
ALSO UPDATED WINDS NEARER THE RUC OUTPUT WHICH IS SLIGHTLY FURTHER
SOUTH WITH THE BOUNDARY OVERNIGHT. THIS BRINGS MORE OF A
NORTHEASTERLY WIND ACROSS THE TULSA METRO...WHICH WILL IMPACT THE
PLACEMENT OF THE URBAN HEAT ISLAND PLUME AND CORRESPONDING
ADJUSTMENTS WERE MADE WHICH LOWERED KTUL AND RAISED KRVS VALUES.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055-
OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-
OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010-
ARZ019-ARZ029.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
159 AM EDT FRI AUG 3 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH SATURDAY. THE
HIGH PRESSURE WILL START TO BREAK DOWN FROM THE NORTHWEST ON
SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE REGION
MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
0530 UTC UPDATE...POPS HAVE BEEN REMOVED FOR THE REST OF TNGT PER
TRENDS. MEANWHILE...A SLOW-MOVING MCS IS GRADUALLY DRIFTING SE ACRS
CENTRAL KY. SOME OF THE OUTFLOW TO ITS EAST IS INITIATING SOME ISOLD
CELLS. THE RAP AND GFS BOTH HAVE ASSOCIATED DPVA ARRIVING AROUND
DAYBREAK ACRS THE NC MTNS. OTHERWISE...SKY/WIND GRIDS WERE UPDATED
FOR 06Z TAFS.
0230 UTC UPDATE...POPS HAVE BEEN UPDATED TO ACCOUNT FOR CONVECTION
IN NE GA...THE SC MOUNTAINS...AND SOUTH OF CHARLOTTE. SKY COVER WAS
UPDATED FROM THE LATEST INFRARED SATELLITE IMAGERY.
AT 907 PM EDT THURSDAY...A MEAN UPPER TROUGH REMAINED ALONG THE
EASTERN SEABOARD...WHILE A WEAK SURFACE TROUGH EXTENDED ALONG THE
APPALACHIANS. A MOIST UNSTABLE AIR MASS REMAINED OVER OUR AREA. AN
OUTFLOW BOUNDARY THAT MOVED NORTHEAST FORM THE SC MIDLANDS HAS
PROVIDED LIFT FOR CONVECTION TO FORM OVER THE UPPER SAVANNAH RIVER
VALLEY AND THE CHARLOTTE METROPOLITAN AREA. THIS CONVECTION SHOWS
LITTLE SIGN OF DECREASING OR MOVEMENT....AND IS EXPECTED OT LINGER
INTO THE LATE NIGHT HOURS. IF PRECIPITATION RATES CAN PERSIST...
HYDROLOGICAL PROBLEMS MAY DEVELOP. MINIMUM TEMPERATURES WILL BE BE
SLIGHTLY ABOVE NORMAL.
LATE IN THE DAY ON FRIDAY THE NAM AND GFS AGREE IN BRINGING AN MCV
INTO THE MTNS...OR PERHAPS A LITTLE WEST OF THE REGION. IN
FACT...THE OVERALL SYNOPTIC PATTERN SUPPORTS INCREASING TROUGHINESS
OVER THE DEEP SOUTH BETWEEN TWO STRONG RIDGES...ONE OVER THE PLAINS
AND ONE OVER THE WESTERN ATLANTIC. LAYER RH VALUES WILL BEGIN TO
INCREASE ACROSS THE REGION LATE FRIDAY...RESULTING IN AN
INCREASINGLY FRIENDLY ENVIRONMENT FOR CONVECTION. POPS HAVE BEEN
RAISED INTO THE HIGH CHANCE TO LOW LIKELY RANGE OVER THE MTNS. THE
PIEDMONT WILL REMAIN UNDER WEAK NVA THROUGH THE DAYLIGHT HOURS AND
POPS HAVE BEEN KEPT LOWER IN THESE ZONES. EVEN WITH THE MOISTENING
ATMOSPHERE...A FEW SEVERE STORMS ARE A GOOD BET IN THE
AFTN...ESPECIALLY OVER THE MOUNTAINS AND FOOTHILLS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 230 PM THU...THE SHORT RANGE WILL FEATURE THE PASSAGE OF A
WEAK WAVE ALOFT LATE FRIDAY NIGHT AND SATURDAY MORNING...WHICH MAY
SERVE TO KEEP CONVECTION FIRING WELL INTO THE OVERNIGHT HOURS GIVEN
THE RELATIVELY DEEP MOISTURE THAT SHOULD BE IN PLACE. SEE NOTHING
THAT SHOULD DISCOURAGE DEEP CONVECTION FROM DEVELOPING WITH DAYTIME
HEATING AGAIN ON SATURDAY...WITH STORMS BECOMING NUMEROUS ACROSS THE
HIGHER TERRAIN LATE IN THE DAY. THE STORMS SHOULD PUSH OFF THE BLUE
RIDGE IN THE EVENING AND EVENTUALLY DIE OFF LATE AT NIGHT...AS
USUAL...SINCE THE UPPER WAVE SHOULD NOT BE AROUND TO HELP MAINTAIN.
EXPECT MORE OF THE SAME ON SUNDAY AS THE SETUP DOES NOT REALLY
CHANGE MUCH. PROFILES LOOK RELATIVELY MOIST AND TEMPS ARE RELATIVELY
WARM AT MID LEVELS...WHICH MAY SERVE TO CUT BACK ON SEVERE STORM
CHANCES. TEMPS WILL STAY NEAR CLIMO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 2 AM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
MONDAY WITH SOME DEGREE OF BROAD UPPER TROFFING LIKELY TO PERSIST
OVER THE REGION THRU DAY 7. WITH THAT SAID...WE CAN EXPECT AN ACTIVE
PERIOD TO PERSIST THRU NEXT WEEK WITH DIURNAL SH AND TS AND NEAR
AVERAGE TEMPS.
PREVIOUS DISCUSSION...
LATEST GUIDANCE THROUGH THE MEDIUM RANGE FAVORS MAINTAINING A
WEAKNESS AT 500 MB BETWEEN THE ATLANTIC SUBTROPICAL HIGH AND THE
ANTICYCLONE OVER THE SOUTHWESTERN U.S.. THE GFS LEAVES AN AREA OF
WEAK Q CONVERGENCE DRAPED ACROSS THE WESTERN CAROLINAS THROUGH
WEDNESDAY AND KEEPS THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERHEAD. AT THE SURFACE...AN OLD FRONTAL BOUNDARY SHOULD BE STALLED
ACROSS THE OH VALLEY. A LIGHT S OR SW FLOW AT LOW LEVELS WILL
MAINTAIN A SUPPLY OF MOISTURE. IN GENERAL...THIS WOULD APPEAR TO
FAVOR AN ENHANCEMENT TO OUR USUAL DIURNAL THUNDERSTORM CHANCES...SO
THAT IS ESSENTIALLY WHAT WILL BE PUT IN THE FCST. THERE MIGHT BE A
SLIGHTLY IMPROVED CHANCE ON WEDNESDAY AS AN UPPER LEVEL FEATURE
MOVES BY TO OUR NORTH. ANY OF THE DAYS THROUGH MID WEEK COULD SEE
NUMEROUS STORMS...BUT FOR NOW WILL LIMIT THE CHANCE TO THE 40 PCT
RANGE. THURSDAY SHOULD HAVE SLIGHTLY DIMINISHED CHANCES IN THE WAKE
OF THE NORTHERN WAVE. TEMPS IN GENERAL WILL STAY NEAR CLIMATOLOGY
WITH THE WARMEST DAY BEING THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AT KCLT...WITH CLEAR SKIES AND CALM WINDS...MAIN CONCERN WILL BE
WHETHER ANY VSBY RESTRICTIONS DEVELOP ACRS THE AREA. GUIDANCE HAS
BEEN TOO PESSIMISTIC WITH VSBYS LATELY. SO GOING WITH 6SM BR FOR NOW
ARND DAYBREAK. EXPECTING NUMEROUS SHRA AND TSRA THIS
AFTN...CONTINUING WELL INTO THE EVENING...AND PROB30 WILL BE
CARRIED. WINDS WILL REMAIN SOUTHERLY...INCREASING TO NEAR 10 KNOTS
THIS AFTERNOON.
ELSEWHERE...GIVEN CLEARING SKIES...CALM/LGT WND AND RELATIVELY LOW
DWPT DEPRESSIONS...I HAVE ADDED A TEMPO FOR MVFR VSBY AT ALL
SITES...AND KEPT THE IFR TEMPO AT KAVL. AN ARRIVING UPPER SYSTEM
WILL SUPPORT MORE WIDESPREAD CONVECTION TODAY...AND PROB30 WILL BE
CARRIED AT ALL SITES. WINDS WILL FAVOR A SOUTHERLY COMPONENT.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...ARK/JAT/MCAVOY
SHORT TERM...PM
LONG TERM...PM
AVIATION...ARK
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1113 PM MDT THU AUG 2 2012
.AVIATION...06Z TAFS
SCT TSTMS MOVING THROUGH CNTRL SD WILL MOVE OUT OF THE AREA BY
09Z. IFR CONDITIONS EXPECTED IN HEAVIER STORMS...OTHERWISE VFR
CONDITIONS EXPECTED OVERNIGHT. STRONG COLD FRONT WILL MOVE THROUGH
NERN WY AROUND 12Z AND WRN SD AROUND 15Z PRODUCING GUSTY NW WINDS
OVER 30KTS IN SOME AREAS.
&&
.PREV DISCUSSION... /ISSUED 829 PM MDT THU AUG 2 2012/
UPDATE...ONE COUNTY REMAINING IN THE WATCH AT 8 PM BUT WE WILL BE
ABLE TO CANCEL THAT ONE WITHIN THE HOUR. THE SEVERE THUNDERSTORM
IN EASTERN PENNINGTON COUNTY WILL MOVE INTO A MORE STABLE AIRMASS
SHORTLY SO NOT SURE HOW MUCH LONGER IT CAN SUSTAIN THE STRONG
UPDRAFT THAT KEPT IT GOING FOR OVER 160 MILES. HRRR HAS HAD A GOOD
HANDLE ON THE LEADING EDGE OF THE SYSTEM ALL EVENING BUT KEEPS TOO
MUCH PRECIP ONGOING BEHIND THE MAIN BAND. A BROAD SURFACE LOW OVER
EASTERN WYOMING IS JUST STARTING TO SHIFT EASTWARD A BIT WITH
SURFACE PRESSURE RISES OF 1 TO 1.5 MB/3HR SHOWING UP IN THE OBS
OVER SOUTHEAST MONTANA AND NORTHEASTERN WYOMING THIS PAST HOUR.
PREV DISCUSSION... /ISSUED 234 PM MDT THU AUG 2 2012/
DISCUSSION...UPPER LEVEL ANALYSIS HAS RIDGING ACROSS THE SOUTHERN
AND SOUTHWESTERN PARTS OF THE UNITED STATES...WITH A WEAK
SHORTWAVE RIDGE CROSSING THE NORTHERN PLAINS. VIGOROUS UPPER LOW
IS CURRENTLY MOVING SOUTHEAST ALONG THE SPINE OF THE SOUTHERN
CANADIAN ROCKIES. SHORTWAVE TROF IS UNDERCUTTING THE RIDGING
ACROSS THE FORECAST AREA...PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS. A STRONG LINE OF STORMS HAVE DEVELOPED FROM NEAR
GILLETTE INTO SOUTHEAST MONTANA. 20Z SURFACE ANALYSIS HAS HIGH
PRESSURE OVER THE EASTERN DAKOTAS WITH LOW PRESSURE DEVELOPING
OVER NORTHEAST WYOMING AND SOUTHEAST MONTANA. TEMPERATURES ARE IN
THE 80S TO LOWER 90S WITH WINDS GENERALLY OUT OF THE SOUTH TO
SOUTHEAST AT 15 TO 25 MPH.
SURFACE LOW AND ASSOCIATED TROF OVER SOUTHEAST MONTANA AND
NORTHEAST WYOMING WILL SLOWLY PUSH EAST THIS AFTERNOON AND
EVENING...AND WILL BE FOCAL POINT FOR STRONG TO SEVERE CONVECTION.
BEST INSTABILITY AND SHEAR RESIDE MAINLY FROM THE BLACK HILLS INTO
NORTHWEST SOUTH DAKOTA...SO EXPECT STRONGEST STORMS TO CROSS THIS
AREA. TEMP/TD SPREADS ARE FAIRLY LARGE...SO MAIN STORM THREAT WILL
BE STRONG GUSTY WINDS...ALONG WITH SOME HAIL. SHOWERS AND STORMS
WILL SHIFT EAST OF THE FORECAST AREA BY LATE THIS EVENING.
FRIDAY...STRONG COLD FRONT WILL PUSH THROUGH OUR WESTERN ZONES IN
THE MORNING AND THROUGH OUR EASTERN ZONES BY EARLY AFTERNOON.
STRONG COLD ADVECTION AND PRESSURE RISES AROUND 3MB/3HR WILL SUPPORT
GUSTY NORTHWEST WINDS...ESPECIALLY ON THE PLAINS OF NORTHWESTERN SD.
CYCLONIC FLOW ALOFT...COMBINED WITH RESIDUAL INSTABILITY/MOISTURE
WILL LEAD TO CHANCES FOR SHOWERS/TSTMS ACROSS OUR CWFA. TEMPS WILL
BE WIDE RANGING...FROM THE 70S IN OUR WEST TO MID/UPPER 90S IN
SOUTH CENTRAL SD AHEAD OF THE COLD PUSH.
SATURDAY...DRY AND COOLER CONDITIONS EXPECTED...ALTHOUGH
BREEZY/WINDY CONDITIONS WILL PREVAIL WITH STRONG NW FLOW ALOFT
MIXING TOWARDS THE SURFACE DURING DAYTIME HEATING.
EXTENDED...RIDGE WILL REBUILD OVER THE WESTERN CONUS...BRINGING A
RETURN TO HOT AND DRY CONDITIONS EARLY IN THE WEEK. A VARIETY OF
WEAK DISTURBANCES WILL PUSH THRU THE RIDGE DURING THE MIDDLE PART OF
THE WEEK...BRINGING OCCASIONAL CHANCES FOR STORMS. ABOVE AVERAGE
TEMPERATURES WILL CONTINUE THROUGH THE PERIOD.
FIRE WEATHER...
KEPT RED FLAG WARNING FOR THE PLAINS OF NORTHEASTERN WYOMING AS DRY
THUNDERSTORMS MOVED ACROSS THE AREA THIS MORNING AND MORE STORMS ARE
FIRING AT THIS TIME. WINDS HAVE FREQUENTLY GUSTED ABOVE 35 MPH EVEN
THOUGH RH VALUES ARE STILL HOLDING AROUND 20 TO 25 PERCENT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...WFO UNR
LONG TERM....WFO UNR
AVIATION...JOHNSON
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1141 PM CDT THU AUG 2 2012
.UPDATE...FOR 06Z AVIATION FORECAST
&&
.AVIATION...
COMPLEX TO OUR NORTH NOT MAKING MUCH PROGRESS AND HAS SLOWED TO A
CRAWL WITH MERGING CELLS OVER WESTERN KENTUCKY AS MOST SOUTHERN
COMPLEX MERGES WITH THE NORTHERN ONE. NOT AN EASY FORECAST FOR THE
OVERNIGHT BUT HERE WHAT I THINK WILL HAPPEN. SHORT WAVE UPSTREAM
NOW OVER SOUTHERN ILLINOIS DOWN INTO SOUTHEAST MISSOURI WILL MOVE
EAST IN THE OVERNIGHT AND INTO THE WESTERN SIDE OF THE TENNESSEE/OHIO
VALLEYS. THE CAP THAT WE HAD EARLIER IS GONE. AS SHORT WAVE
APPROACHES IT WILL SHARPEN AND THIS WILL INTENSIFY CONVECTION ON
THE SOUTHWEST SIDE OF THE MCS ACROSS SOUTHERN ILLINOIS AND EXTEND DOWN
THROUGH WESTERN KENTUCKY. AS CONVECTION DEVELOPS IT WILL DROP
SOUTHEAST AND INTO MIDDLE TENNESSEE IN THE OVERNIGHT. I EXPECT
STORMS IN THE BNA AREA BY 08Z-10Z TIME FRAME/EARLIER AT CKV.
BOYD
&&
.PREV DISCUSSION... /ISSUED 1002 PM CDT THU AUG 2 2012/
UPDATE...TERMINAL FORECASTS
AVIATION...
COMPLEX THAT HAD BEEN HEADED THIS WAY HAS SHOWN A MORE EASTWARD
TREK TOWARD SOUTHWEST INDIANA/KENTUCKY. MODELS NOT HANDLING THIS
VERY WELL BUT NAM MAY HAVE THE BEST HANDLE AT THE MOMENT. CAP
CONTINUES TO HOLD OVER MIDDLE TENNESSEE BUT LATEST RUC FORECAST
HAS IT WEAKENING TOWARD 06Z WITH TEMPS < +12 CELSIUS AT 700
MILLIBARS BY 04Z ACROSS THE MID STATE. THIS SHOULD ALLOW FOR SOME
SOUTHWARD EXTENSION OF ACTIVITY DOWN INTO MIDDLE TENNESSEE AS WE
GO TOWARD MIDNIGHT AND THROUGH THE OVERNIGHT HOURS. I COMPLETELY
REWORKED TERMINAL FORECASTS FOR REMAINDER OF THE 24 HOUR PERIOD.
CONFIDENCE IS LOW ON ANY PARTICULAR TIMING FOR STORMS SO WENT WITH
VICINITY TSTMS.
BOYD
PREV DISCUSSION... /ISSUED 953 PM CDT THU AUG 2 2012/
UPDATE...
FRONTAL BOUNDARY CONTINUES TO HANG JUST NORTH OF THE TN BORDER...
WITH MID-LEVELS ACROSS THE FCST AREA CAPPED AT THIS POINT. COMPLEX
IN WEST KY...SOUTH IL/IN WAS EXPECTED TO MOVE SOUTH BUT CURRENTLY
IS PUSHING MORE EAST...WITH SOUTHERN FLANK STRUGGLING TO DEVELOP.
CAP SLOWLY WEAKENS LATER THIS EVE BUT LATEST DATA SUGGESTING SCT
STORMS WILL AFFECT MAINLY THE NORTH AND ESPECIALLY ALONG THE KY
BORDER THRU 12Z...THEN BECOME MUCH MORE NUMEROUS ON FRIDAY. AT
THIS TIME WILL RUN WITH CHANCE POPS...LEANING HIGHER NORTH...AND
KEEP SOUTH GENERALLY UNCHANGED. MAY UPDATE AGAIN LATER SHOULD
COMPLEX MAKE STRONG TURN SOUTH.
PREV DISCUSSION... /ISSUED 754 PM CDT THU AUG 2 2012/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
GOOD CAP (+12 TO +13 DEGREES CELSIUS AT 700 MB) IN PLACE ACROSS
NORTHERN MIDDLE TENNESSEE THIS EVENING HAS KEPT CONVECTION FROM
DEVELOPING AROUND NASHVILLE. COMPLEX OVER SOUTHERN ILLINOIS HAS
BEEN HEADED SOUTHEAST BUT IN THE LAST COUPLE OF PICS IT HAS SHOWN
A LITTLE MORE EASTWARD COMPONENT. WILL HAVE TO KEEP TABS ON THIS
AS MODELS BRING IT DOWN INTO WESTERN KY DURING THE EVENING AND
INTO MIDDLE TN AROUND MIDNIGHT.
LOOK FOR SOME LATE NIGHT FOG AT CROSSVILLE.
BOYD
PREV DISCUSSION... /ISSUED 351 PM CDT THU AUG 2 2012/
DISCUSSION...
FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION
COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.
FORECAST QUANDARIES...IMPACTS OF POTENTIAL MCS TONIGHT AND ON FRI...
POTENTIAL FOR SHWRS/TSTMS THRU MID WEEK NEXT WEEK...TEMPS.
AS FOR TONIGHT...WILL BE WAITING CLOSE TO PRESS TIME PER REGIONAL
RADAR TRENDS FOR FINAL DECISION...BUT EXPECT MVV ACROSS NRN MO
PRESENTLY...ALONG WITH DEVELOPING EMBEDDED SHORTWAVE IN
PREDOMINATELY NWLY FLOW ALOFT...TO RESULTING IN EVENTUAL AN MCS
DEVELOPMENT EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING ACROSS
CNTRL AND SERN MO...EVENTUALLY MOVING SEWD INTO AT LEAST WRN
PORTIONS OF THE MID STATE DURING THE LATE EVENING HRS. MAY NEED TO
BREAK OUT A LATE AFTERNOON GROUPING IN THE ZONE FORECAST PRODUCT
TO EMPHASIZE ACTUAL TIMING IMPACTS. WILL CONTINUE TO GO WITH
REASONING CLOSE TO MORNING FORECAST PACKAGE WITH MOST LOCATIONS W
OF THE PLATEAU HAVING A CHANCE...TO EVEN LIKELY...SHWRS/TSTMS
TOWARD DAYBREAK. WILL GO CLOSE TO CONSENSUS MODEL GUIDANCE ON
LOWS...MAINLY IN THE MID 70S...BUT...WITH CLOUD COVERAGE POSSIBLY
NOT AS PRONOUNCED ACROSS THE PLATEAU AND ONLY A SLIGHT CHANCE OF
SHWRS/TSTMS PLATEAU LATE...WILL GO A COUPLE OF DEGREES COOLER THAN
CONSENSUS GUIDANCE WITH LOWS MAINLY IN THE MID 60S.
AS FOR FRI...WILL CONTINUE CLOSE TO PREVIOUS MORNING FORECAST
REASONING CONCERNING FRI ALSO...WITH SHWRS/TSTMS LIKELY AREA WIDE
DURING AT LEAST THE MORNING HRS. WITH SOME TIMING UNCERTAINTIES
STILL IN PLAY THOUGH TO ACTUAL MOVEMENT AND EVENTUAL DISSIPATION
ACROSS THE MID STATE...ALONG WITH THE CONTINUED PRESENCE OF A WEAK
SFC BOUNDARY...EXPECT SOME CLRING POSSIBLY LATE...BUT WILL GO WITH
HIGH CHANCE POPS FOR LOCATIONS GENERALLY W OF THE PLATEAU. WILL GO
WITH A MODEL COMPROMISE ON HIGHS FOR FRI...WITH MOST LOCATIONS W OF
THE PLATEAU IN THE UPPER 80S...MID 80S PLATEAU.
AS FOR FRI NIGHT...EXPECT AN UNSETTLED WX PATTERN THRU FRI NIGHT WITH
A CHANCE OF SHWRS/TSTMS THRU THE NIGHT...WITH LOWS MAINLY IN THE LOWER
70S...UPPER 60S TO 70 PLATEAU AS UPPER LEVEL FLOW BECOMES MORE ZONAL
ORIENTATED IN NATURE...AND NOT MUCH POTENTIAL FOR OVERALL AIRMASS
MOISTURE TO SIGNIFICANTLY DRY OUT AFTER AFTERNOON MCS INFLUENCES
HAVE WEAKENED.
AS FOR SAT...AS MENTIONED ALSO IN THIS MORNINGS DISCUSSION...AND
MODELS CONSENSUS CONTINUING TO EMPHASIZE...ANOTHER SHORT WAVE IS
EXPECTED TO SCOOT EASTWARD IN THE UPPER LEVEL FLOW...ACROSS
KENTUCKY...ON SAT. HOWEVER...THIS DISTURBANCE CONTINUES TO LOOKS
TO BE A LITTLE WEAKER AND...PERHAPS...A LITTLE FURTHER N THAN THE
UPPER LEVEL FLOW PATTERN ACROSS THE MID STATE FRI NIGHT. HOWEVER...
TSTMS TO OUR N SHOULD BE CLOSE ENOUGH TO SWING SOME OUTFLOW
BOUNDARIES SWD INTO OUR OUR NRN COUNTIES. IN ADDITION...AND IT
CONTINUES TO LOOK SO...ATM ACROSS THE MID STATE WILL REMAIN
CHOCKED FULL OF MOISTURE...SUPPORTIVE OF AT LEAST SCT TSTMS DURING
THE DAY ON SAT PER DIURNAL HEATING INFLUENCES KICKING IN...AND
WILL CONTINUE WITH HIGH CHANCE POPS AREA-WIDE. WILL GO WITH HIGHS
CLOSE TO CONSENSUS GUIDANCE VALUES AROUND 90...MID 80S PLATEAU.
AS FOR SAT NIGHT...THE POTENTIAL FOR AN UPPER LEVEL EMBEDDED SHORTWAVE
PASSAGE AROUND THE BASE OF A DEVELOPING UPPER LEVEL TROUGH ACROSS AT
LEAST NRN PORTIONS OF THE MID STATE MAY BE POSSIBLE SAT NIGHT...AND
THUS WILL CONTINUE WITH A CHANCE OF SHWRS/TSTMS THRU THE NIGHT TIME
HRS. LOWS WILL MAINLY BE IN THE LOW TO MID 70S...AROUND 70 TO UPPER
60S PLATEAU.
AS FOR THE REMAINDER OF THE FORECAST PERIOD...A CONTINUANCE OF THE
OVERALL UNSETTLED WX PATTERN ON SUN AND MON...WITH A POTENTIAL DRYING
TREND TOWARD THE MID PORTION OF NEXT WEEK IS THE GENERAL TREND FOR
THE REMAINDER OF THE FORECAST PERIOD. OVERALL...IT LOOKS LIKE THE MID
STATE WILL EITHER BE POSITIONED BETWEEN A SUMMERTIME COLD FRONT TO
OUR N...AND A WARM MOIST AIRMASS TO OUR S...IF YOU LEAN MORE
TOWARD THE EURO SOLUTION...OR THIS FRONT WILL PASS THRU THE MID STATE
FROM OUR N SOMETIME LATE SUN NIGHT OR MON...AND THE AREA WILL BEGIN
TO EXPERIENCE A DRYING AND WARMING TREND...IF YOU LEAN MORE TOWARD
THE GFS SOLUTION. WITH SOME OVERALL UNCERTAINTY IN MIND...ESPECIALLY
WHEN YOU FIGURE IN THE POSSIBILITY OF A POTENTIAL SHORTWAVE PASSAGE
ACROSS THE NRN PORTIONS OF THE MID STATE ON SUN AIDING TO ADDITIONAL
POTENTIAL FOR TSTM DEVELOPMENT...BELIEVE AT THIS TIME...THAT OVERALL...
PREVIOUS FORECAST REASONING IS STILL VERY SOUND...AND OTHER THAN A
TWEEK HERE AND THERE...WILL CONTINUE TO LEAN TOWARD IT ACCORDINGLY...
I.E. MORE TOWARD THE GFS SOLUTION. THUS...WILL CONTINUE WITH THE
MENTIONING OF LIKELY SHWRS/TSTMS DURING THE DAYLIGHT HOURS ON SUN...
WITH A DRYING TREND BEGINNING TO ESTABLISH ITSELF BY MID WEEK. THIS
WILL RESULT IN TEMPS NEAR OR SLIGHTLY ABOVE SEASONABLE NORMS...WITH
HIGHS IN THE UPPER 80S TO LOWER 90S...MID 80S PLATEAU...AND LOWS
AROUND 70...MID 60S PLATEAU.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1158 PM CDT THU AUG 2 2012
.UPDATE...
UPDATED FORECAST FOR LINE OF SCATTERED CONVECTION DEVELOPING IN
850 MB CONFLUENT AREA AHEAD OF SURFACE FRONT. MAINLY SPOTTY
MODERATE SHOWERS BUT SOME ISOLATED THUNDER. LOW LEVEL CONVERGENCE
AIDED BY LIFT FROM UPPER DIVERGENCE IN RRQ OF 300 MB SPEED MAX.
EXPECT CONVECTION TO DIMINISH AS THIS ENHANCED LIFT MOVES OFF WITH
SPEED MAX OVERNIGHT.
&&
.AVIATION/06Z TAFS/...
HAVE PUT VICINITY AT EACH SITE WITH TEMPO MVFR VSBYS TIMED WITH
SOUTHEAST=MOVING LINE OF SCATTERED CONVECTION. EXPECT LINE TO
BEGIN TO DIMINISH FROM WEST TO EAST AFTER 08Z AS UPPER SUPPORT
SHIFTS TOT HE EAST. SURFACE COOL FRONT WILL DROP IN WITH NORTHEAST
WINDS BRIEFLY COMING UP TO AROUND 10 KTS AT NEAR-LAKE SITES. HAVE
MVFR VSBYS IN FOG POST-RAIN EXCEPT AT KMKE AND KENW DUE TO
EXPECTED HIGHER SFC WIND WITH FRONTAL PASSAGE.
&&
.PREV DISCUSSION... /ISSUED 354 PM CDT THU AUG 2 2012/
SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF RAIN SHOWERS CONTINUES TO SHIFT EAST ACROSS THE NORTHERN
COUNTIES OF THE FORECAST AREA. THIS AREA AIDED BY MODEST 850MB/700MB
MOISTURE POOLING/CONVERGENCE AND LOW LEVEL FRONTOGENESIS RESPONSE.
THIS AREA SHOULD CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF THE
AFTERNOON ACROSS THE NORTHEAST COUNTIES...ALONG WITH ASSOCIATED
UPWARD VERTICAL MOTION.
WEAK COLD FRONT FROM WEST CENTRAL TO NORTHEAST WISCONSIN IS EXPECTED
TO SAG SOUTHWARD THROUGH THE AREA THIS EVENING...THEN TO THE SOUTH
LATER TONIGHT. AREA OF WEAK TO MODEST 850MB CONFLUENCE ALSO SHIFTS
SOUTH INTO THE AREA AND LINGERS THROUGH THE NIGHT. AREA FORECAST
SOUNDINGS SHOWING CAP MIXING OUT ACROSS SOUTHERN PORTIONS OF THE
AREA WHERE CLOUDS MOVED AWAY...WITH AROUND 500 J/KG MEAN LAYER CAPE.
CLOUDIER AREAS WOULD HAVE LESS CAPE AND MORE CAPPING.
CAPE BECOMES MORE ELEVATED TONIGHT AND WOULD HAVE TO BE REACHED BY
ELEVATED PARCELS. HRRR MODEL SHOWING WIDELY SCATTERED CELLS AT BEST
DEVELOPING LATE THIS AFTERNOON INTO THE EARLY EVENING. KEPT POPS FOR
LATE THIS AFTERNOON INTO TONIGHT WITH THE ABOVE FORCING MECHANISMS
MOVING IN. A GOOD PORTION OF THE AREA LIKELY WILL BE DRY.
SCATTERED MID LEVEL CLOUDS EXPECTED TONIGHT INTO FRIDAY. DRIER AIR
WORKS INTO THE AREA FRIDAY ON EASTERLY WINDS. KEPT DRY FORECAST
GOING FOR FRIDAY WITH DECENT CAP ACROSS THE AREA. LOWS TONIGHT
SHOULD FALL TO THE MID TO UPPER 60S...WITH ANOTHER VERY WARM DAY IN
THE UPPER 80S TO LOWER 90S AWAY FROM THE LAKE. EAST WINDS KEEPS
HIGHS COOLER NEAR LAKESHORE.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
A FAIRLY SHARP UPPER TROUGH WILL TRACK EWD FROM THE NRN HIGH
PLAINS THROUGH THE GREAT LAKES DURING THIS PERIOD WITH AN
ORGANIZED LOW PRESSURE AREA MOVING ALONG THE US/CANADIAN BORDER.
THETAE ADVECTION WILL BOOST PWS TO NEARLY ONE INCH FOR SAT
AFTERNOON AND EVENING AHEAD OF AND ALONG THE COLD FRONT ALONG WITH
MODERATE INSTABILITY AND WIND SHEAR. THUNDERSTORMS WILL LIKELY
DEVELOP SAT AFTERNOON OVER WRN WI AND THEN MOVE EWD THROUGH SAT
EVENING. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST BY SPC
AND LOOKS GOOD. COLD AND DRY ADVECTION WILL THEN PREVAIL ON SUNDAY
WITH A PLEASANT DAY FOLLOWED BY HIGH PRESSURE THROUGH MON NT.
LONG TERM...
SRN WI WILL BE ON THE SRN PERIPHERY OF NW FLOW WITH ONLY A WEAK
COOL FRONT TO POSSIBLY BE IN THE VICINITY OF SRN WI FROM TUE-WED.
THUS ONLY SLIGHT CHANCE OF TSTORMS DURING THAT TIME. TEMPS WILL BE
AT LEAST SLIGHTLY ABOVE NORMAL NEXT WEEK.
AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH FRIDAY ACROSS TAF SITES. CURRENT
SHOWER ACTIVITY WILL CONTINUE TO REMAIN NORTH OF TAF SITES. EXPECT
SCATTERED TO BROKEN MID LEVEL CLOUDS THROUGH THE LATE AFTERNOON.
EAST/SOUTHEAST WINDS ARE EXPECTED TO LINGER AT MILWAUKEE AND REACH
WAUKESHA BY 22Z. LIGHT WINDS ARE EXPECTED TO LINGER AT MADISON.
WEAK COLD FRONT SLIDING SOUTH TOWARD THE AREA LATE THIS
AFTERNOON...AND THROUGH THE AREA THIS EVENING. FRONT WOULD BRING
MAINLY SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
EVENING...AND A SHOWER AFTER MIDNIGHT. HOWEVER...TOO MUCH
UNCERTAINTY RIGHT NOW TO MENTION IN TAFS.
LIGHT EAST TO NORTHEAST WINDS TONIGHT SHOULD REMAIN EASTERLY ON
FRIDAY ACROSS TAF SITES...WITH FEW TO SCATTERED MID LEVEL CLOUDS.
EASTERLY WINDS BRING DRIER AIR INTO THE AREA LATER TONIGHT AND
FRIDAY...WITH QUIET WEATHER EXPECTED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1055 AM EDT FRI AUG 3 2012
.UPDATE (REST OF TODAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE FLORIDA PENINSULA
CONTINUES TO RESIDE UNDERNEATH A SUBTLE WEAKNESS IN THE HEIGHT
FIELDS TO THE EAST OF AN IMPRESSIVE AND DOMINANT UPPER LEVEL RIDGE
ACROSS THE SOUTHERN PLAINS. THIS UPPER RIDGE IS ACTUALLY ONE OF THE
MORE VISUALLY IMPRESSIVE ANTICYCLONES ON WV IMAGERY THAT THIS
FORECASTER HAS SEEN...WITH A VERY SYMMETRIC LOOK OF DRY
AIR/SUPPRESSION AT ITS CORE AND RINGED BY A MID/UPPER LEVEL MOISTURE
BELT. LOOKING AT THE LARGER PICTURE...THE MAIN NORTHERN STREAM FLOW
IS HELD BY THIS RIDGE UP ALONG THE U.S/CANADIAN BORDER. AN
IMPRESSIVE DISTURBANCE WITHIN THIS FLOW IS CURRENTLY DROPPING OUT OF
THE CANADIAN ROCKIES INTO THE HIGH PLAINS. THIS ENERGY WILL LIKELY
BE THE FOCUS FOR A ROUND OF STRONG/SEVERE STORMS ACROSS THE HIGH
PLAINS STATES LATER TODAY.
AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS SHIFTED NORTHWARD
OVER THE PAST 24 HOURS AND IS NOW ALIGNED OVER THE NORTHERN FL
PENINSULA/NE GULF OF MEXICO. ROTATING AROUND THE SOUTHERN PERIPHERY
OF THIS RIDGE WE FIND A RATHER WELL DEFINED INVERTED TROUGH/TROPICAL
WAVE FEATURES CROSSING THE BAHAMAS AND APPROACHING THE FL EAST
COAST. THIS FEATURE IS THE FOCUS FOR QUITE A BIT OF CONVECTION TO
THE EAST OF FLORIDA...BUT SO FAR HAS NOT MOVES FAR ENOUGH WEST TO
SIGNIFICANTLY INFLUENCE THE CONVECTIVE POTENTIAL FOR OUR REGION.
MOSTLY SUNNY SKIES HAVE BEEN RULE ACROSS THE FL WEST COAST THIS
MORNING. THIS NEAR MAX OF INSOLATION HAS ALLOWED TEMPS TO QUICKLY
WARM INTO THE MID/UPPER 80S...AND WE ARE JUST ABOUT AT THE POINT TO
INITIATE THE SEA-BREEZE. WILL SEE A SCT CU FIELD BEGIN DEVELOPING
WITH THIS SEA-BREEZE WITHIN THE NEXT HOUR OR 2...ALONG WITH A FEW
ISOLATED SHOWERS.
THE CURRENT THINKING ON THE MOST LIKELY CONVECTIVE CYCLE FOR THE
REMAINDER OF THE DAY WILL BE FOR ISOLATED-WDLY SCT SHOWERS/STORMS
EARLY THIS AFTERNOON WHICH WILL MIGRATE INLAND FROM THE I-75
CORRIDOR. THEREAFTER...WITH THE APPROACH OF THE SURFACE WAVE FROM
THE EAST...WILL SEE OUR 1000-700MB FLOW TRANSITION TO A MORE
EASTERLY DIRECTION. THIS SYNOPTIC INFLUENCE SHOULD HELP PROPEL THE
EAST COAST SEA-BREEZE ACROSS THE PENINSULA BY LATE AFTERNOON/EARLY
EVENING. THE INTERACTION OF BOTH SEA-BREEZES SHOULD BE GREATEST FROM
TAMPA BAY SOUTHWARD WHERE A SECOND ROUND OF CONVECTION MAY
ACTUALLY PUSH BACK TOWARD THE WEST COAST WITH TIME. MID-LEVEL
CONVECTIVE POTENTIAL IS ACTUALLY VERY FAVORABLE FOR DEEP CONVECTION
WITH THETAE VALUES IN THE LOWER 330S. OUR LOCAL HIRES GUIDANCE ALONG
WITH SEVERAL OF THE NATIONAL HI-RES MEMBERS ARE SHOWING SOMETHING
SIMILAR TO THIS SCENARIO.
&&
.PREVIOUS DISCUSSION (TONIGHT THROUGH SUNDAY)...
THE TROUGHINESS ALOFT CONTINUES TO WEAKEN AS IT SLIDES WEST OVER
THE GULF AS THE UPPER RIDGE IN THE ATLANTIC BEGIN TO BUILD
SOUTHWESTWARD TODAY. THE SURFACE RIDGE AXIS LIFTS UP INTO NORTHERN
FL AS THE TROPICAL WAVE APPROACHES THE EAST FL COAST. ON SAT - THE
UPPER RIDGE SPREADS OVER FL AS THE SURFACE RIDGE AXIS MOVES INTO
SOUTHERN GA WITH THE TROPICAL WAVES CROSSING THE STATE TO THE WEST
COAST. FOR SUN - BOTH THE UPPER AND SURFACE RIDGES PIVOT NORTH...
TO THE SE U,S. COAST AS THE WAVE SLIDES OUT OVER THE GULF. THE SW
AND WEST LOW LEVEL FLOW OF THE PAST FEW DAYS WILL GIVE WAY TO
SOUTHEAST AND THEN EASTERLY FLOW AS THE RIDGE AXIS MOVES NORTH AND
THE WAVE CROSSES THE AREA. THE PREVAILING LOW LEVEL FLOW THEN BACKS
TO SE SUN AS THE RIDGE CONTINUES NORTH AND THE WAVE MOVES AWAY.
THE FLOW WILL BE LIGHT ENOUGH FOR SEA BREEZE CIRCULATIONS EACH
DAY...HOWEVER THE MORE EASTERLY FLOW SAT WILL KEEP THE SEA BREEZE
CLOSE TO THE COAST. THE ATMOSPHERE MOISTENS WITH PWAT VALES
RUNNING OVER 2 INCHES THROUGH THE WEEKEND.
THE FORECAST WILL BE TYPICAL FOR EARLY AUGUST. THE MOIST
AIR MASS...SEA BREEZE CONVERGENCE...AND DAY TIME HEATING WILL
RESULT IN ISOLATED BECOMING SCATTERED CONVECTION DURING THE DAY
THAT LINGERS INTO THE EVENING. EXCEPT SUN WILL SEE NUMEROUS STORMS
OVER COASTAL LOCATIONS DUE TO A MORE ROBUST SEA BREEZE. THIS
PATTERN FAVORS A FEW STORMS BECOMING STRONG WITH THE GREATEST
THREAT WIND. TEMPERATURES WILL RUN JUST ABOVE NORMAL ALTHOUGH THE
HIGHS WILL DIP A DEGREE OR TWO BETWEEN THIS AFTERNOON AND SUN.
&&
.AVIATION...
MAINLY VFR TODAY WITH JUST ISOLATED TO WIDELY SCATTERED STORMS
AROUND AFTER 15Z. CONFIDENCE IN COVERAGE AND TIMING TOO LOW TO
INCLUDE TEMPO GROUPS AT THIS TIME.
&&
.MARINE...
SOUTH AND SW WINDS WITH AN AFTERNOON SEA BREEZE FOR TODAY WILL SHIFT
TO SE AND EAST FOR THE WEEKEND AND EARLY NEXT WEEK...BUT WITH A SEA
BREEZE NEAR THE COAST IN THE AFTERNOONS. WITH WIND SPEEDS OF 10 KT
OR LESS THE MAIN MARINE HAZARD WILL BE ISOLATED TO SCATTERED
THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 92 77 92 76 / 40 20 40 30
FMY 93 75 92 75 / 40 20 50 30
GIF 94 74 93 74 / 40 30 50 20
SRQ 92 75 92 75 / 40 20 40 30
BKV 93 71 92 72 / 30 20 40 30
SPG 91 79 91 76 / 30 20 40 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
PREVIOUS DISCUSSION...RUDE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
630 AM CDT FRI AUG 3 2012
.SHORT TERM /TODAY/...
MOST IMMEDIATE CONCERN INVOLVES FATE OF SMALL MCS ALONG SD/NE
BORDER. CLUSTER IS ELEVATED...MOST LIKELY ALONG 310K ISENT
SURFACE...WITHIN STRONG MLCIN. RAP SUGGESTS MOISTURE TRANSPORT AND
CONVERGENCE ALONG THIS SURFACE WILL MAINTAIN ITSELF TO OUR WEST WITH
LITTLE MOVEMENT INTO THE MORNING SO WILL LEAVE OUR FORECAST DRY
TODAY. RECENT UPSTREAM DEVELOPMENT SUPPORTS THIS SCENARIO AS WELL.
NONE OF THE EXPLICIT OR PARAMETERIZED MODEL GUIDANCE SUGGESTS THIS
WILL MAINTAIN ITSELF EASTWARD INTO IA EITHER.
NEXT CONCERN WILL BE TEMPS. FORECAST SOUNDINGS AND LOW LEVEL TEMP
CHANGE FROM YESTERDAY SUGGEST HIGHS MAY BE A FEW DEGREES WARMER
WHICH MAKES SENSE AS LOW LEVEL WINDS SLOWLY VEER AND INCREASE
SLIGHTLY. TRIMMING A FEW DEGREES OFF THE OFTEN OVERAGGRESSIVE TOO
SUPER ADIABATIC NAM SUGGESTS HIGHS IN THE MID/UPPER 90S. LOWERING
DEWPOINTS WITH MIXING THIS AFTERNOON WILL KEEP HEAT INDICES
PLUS/MINUS A FEW DEGREES OF THE ACTUAL TEMPERATURE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
MODELS ARE A LITTLE SLOWER WITH THE SHORTWAVE TONIGHT ALSO THE BEST
FORCING. AS A RESULT A BACKED OFF ON POPS THIS EVENING AND ON AREAL
EXTENT OF POPS OVERNIGHT. UPPER TROUGH AND SURFACE COLD FRONT MOVE
THROUGH MOST OF CENTRAL IOWA DURING THE MORNING INTO EARLY
AFTERNOON. WHILE THE SYSTEM IS DYNAMIC...IT MOVES THROUGH MUCH OF
THE CWA BEFORE PEAK HEATING SO THE BEST INSTABILITY WON/T BE
REALIZED UNTIL THE SYSTEM IS MOSTLY EAST OF THE CWA. THE
INTERESTING THING TO FORECAST FOR SATURDAY WILL BE TEMPS. SOUNDINGS
SHOW THE DAYS HIGHS OCCURRING AROUND 18Z THEN BEGINNING TO FALL
OFF. CLOUDS/PRECIP WILL IMPACT THE CWA AND THERE WILL LIKELY BE A
PRETTY BIG THERMAL GRADIENT ACROSS THE STATE WITH MID 70S NORTHWEST
AND MID 90S SOUTHEAST. SUNDAY WILL SEEM LIKE FALL WITH HIGHS IN THE
70S AND 80S. THIS WILL BE SHORT LIVED HOWEVER AS THE UPPER RIDGE
REBUILDS OVER THE WEST EARLY NEXT WEEK. WHILE TEMPS ARE FORECAST TO
WARM BACK UP INTO THE 80S AND 90S...IT WILL NOT BE AS WARM AS IT HAS
BEEN. NUMEROUS SHORTWAVES WILL RIDE ATOP THE RIDGE ACROSS IOWA BUT
TIMING AND STRENGTH OF THESE WAVES LEAVES THE POP FORECAST DIFFICULT
AT BEST. MODELS DIFFER ON INTENSITY AND TIMING BUT IN THE TUESDAY
NIGHT/WEDNESDAY TIMEFRAME ONE WAVE LOOKS LIKE IT WILL AFFECT THE
WESTERN PORTION OF THE FORECAST AREA. ANOTHER STRONGER WAVE MOVES
IN LATE IN THE EXTENDED...AROUND FRIDAY/FRIDAY NIGHT. POPS WERE HIT
HARDEST DURING THIS TIME BUT WITH MODEL DISCREPANCIES AND WEAKER
WAVES IN BETWEEN THE AFOREMENTIONED DAYS...I DID NOT FEEL SLIGHT
POPS WERE WARRANTED. HOWEVER...AS RESOLUTION BECOMES BETTER...WE
WILL LIKELY SEE OTHER PERIODS OF PRECIP DURING THE EXTENDED.
&&
.AVIATION...03/12Z
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD WITH NOTHING MORE
THAN SCT-BKN MID CLOUDS AT BEST. ONLY OTHER CONCERN WOULD BE THE
POSSIBILITY OF CONVECTION AFFECTING NORTH AND WEST SITES /KFOD/KMCW/
EARLY SAT MORNING. CONFIDENCE IN THIS OCCURRENCE...TIMING AND
LOCATION...AS WELL AS POTENTIAL THUNDER AND/OR LOWER CATEGORY
CONDITIONS...ARE TOO LOW TO ADDRESS AT THIS TIME.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...BSS
LONG TERM...FAB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
909 AM MDT FRI AUG 3 2012
.UPDATE...
ISSUED AT 856 AM MDT FRI AUG 3 2012
JUST COMPLETED AN UPDATE. FIRST THING WAS TO ADJUST THE CLOUD
COVER DOWN TO NEXT TO NOTHING THIS MORNING. MAIN CHANGE WAS FOR
THE WINDS...MAINLY FOR TONIGHT AND TOMORROW. OUTFLOW BOUNDARY OR
WEAK FRONT OVER THE EASTERN OF THE AREA SHOULD PULL AWAY. THE RUC
AND NAM CATCHING THIS PLUS THE LOCATION OF THE INCOMING FRONT. RUC
AND ESPECIALLY NAM WAS CATCHING THE SURFACE LOW AND TROUGH
POSITION FROM WESTERN NEBRASKA INTO EASTERN COLORADO THE BEST AND
WAS THE FARTHEST SOUTH WITH IT.
SO WENT AHEAD AND ADJUSTED WINDS WITH THE NAM. NAM BRINGS THE
FRONT IN A LITTLE FASTER AND CONSIDERING WHAT AM SEEING WITH THE
INITIAL SURFACE AND UPPER AIR ANALYSIS THIS MORNING...THIS LOOKS
VERY REASONABLE. FRONT PUSHES INTO THE EXTREME NORTHWEST PORTION
OF THE AREA AT 06Z AND THEN THROUGH THE REST OF THE AREA BY 12Z.
CONSIDERING THE COLD AIR AM SEEING WITH THIS SYSTEM...THE PRESSURE
GRADIENT AND RATHER HIGH 3 HOUR PRESSURE RISES BEHIND...INCREASED
THE WINDS BEHIND THE FRONT. COULD GET WINDY FOR A FEW HOURS BEHIND
THE FRONT.
AM GETTING MIXED SIGNALS ON WHERE THE THUNDERSTORMS ARE GOING TO
DEVELOP THIS AFTERNOON. HRRR IS DEVELOPING STORMS IN THE FAR EAST
WITH THE RUC AND NAM DEVELOPING STORMS NEAR THE TROUGH NEAR/OVER
THE WESTERN PORTION OF OUR AREA. CURRENT GRIDS CAPTURE BOTH OF
THESE SCENARIOS FOR AND WILL LEAVE AS IS FOR NOW. PLAN ON LEAVING
MAXES AS IS FOR NOW AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 200 AM MDT FRI AUG 3 2012
IT APPEARS THAT WEATHER DISTURBANCE CURRENTLY GENERATING THUNDERSTORMS
IN NORTHERN NEW MEXICO WILL EMERGE OVER THE SOUTHERN PORTION OF
THE FORECAST AREA BY NOON TODAY THEN INCREASE IN COVERAGE OVER
AREAS GENERALLY EAST OF THE CO/KS BORDER BY THE END OF THE DAY.
THIS AREA OF PRECIPITATION SHOULD MOVE EAST BY MIDNIGHT TONIGHT WITH
ANOTHER CHANCE ACROSS THE AREA AFTER MIDNIGHT AS A COLD FRONT
MOVES THROUGH. THIS AREA OF PRECIP WILL MOVE SOUTHEAST DURING THE
DAY SATURDAY AND BY THE END OF THE DAY BE NEAR ARE
SOUTHERN/SOUTHEASTERN FORECAST AREA OR SLIGHTLY OUTSIDE OF IT.
SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BE DRY AS THE MOISTURE
SOURCE AND ANY FORCING REMAIN SOUTH AND WEST OF THE AREA.
HIGH TEMPERATURES TODAY IN THE 90S WITH AROUND 102 IN THE HILL
CITY AREA. ON SATURDAY NOTICEABLY COOLER TEMPERATURES IN THE MID
70S NEAR FLAGLER TO MID 80S NEAR HILL CITY WITH GUSTY NORTH TO
NORTHEAST WINDS. SLIGHTLY WARMER AND CLOSE TO NORMAL ON SUNDAY
WITH UPPER 80S TO MID 90S.
WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT LOW TEMPERATURES SHOULD
DROP INTO THE LOW TO MID 50S. RECORD OR NEAR RECORD LOW
TEMPERATURES ARE POSSIBLE IN HILL CITY (54 IN 1974)...YUMA
(50)...AND COLBY (51).
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 200 AM MDT FRI AUG 3 2012
PRECIPITATION CHANCES RETURN TO THE AREA MONDAY NIGHT THROUGH
WEDNESDAY NIGHT AS WEATHER DISTURBANCES WITHIN MONSOONAL MOISTURE
MOVE ACROSS THE AREA. THURSDAY APPEARS TO BE DRY. HIGH
TEMPERATURES THROUGH THE PERIOD GENERALLY IN THE 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 145 AM MDT FRI AUG 3 2012
VFR CONDITIONS EXPECTED AT KGLD THROUGH 00Z. FROM 00Z TO 12Z VFR
PREVAILING BUT COULD DROP INTO MVFR RANGE FOR CIGS/VIS SHOULD A
THUNDERSTORM MOVE OVER THE TERMINAL. AFTER 09Z MAY SEE SOME POST
FRONTAL STRATUS AND REDUCED CIGS FOR A BRIEF PERIOD. TOO FAR OUT
RIGHT NOW TO INCLUDE IN TAF.
FOR KMCK VFR ALSO EXPECTED THROUGH THE DAY WITH INCREASING CHANCE
TO LOWER INTO MVFR RANGE BY 00Z AND CONTINUING THROUGH 12Z AS
THUNDERSTORM COVERAGE INCREASES OVER THE AREA. HERE TOO STRATUS
MAY REDUCE CIGS IN THE 7-10Z TIMEFRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS WICHITA KS
659 AM CDT FRI AUG 3 2012
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MCV FROM EARLIER CONVECTION ACROSS WEST CENTRAL KANSAS CONTINUES
TO SPIN OVER CENTRAL KANSAS BRINGING LIGHT RAIN SHOWERS TO KRSL
AND KSLN. ADDITIONAL ACTIVITY WAS DEVELOPING OVER NORTHERN
OKLAHOMA AND MAY DRIFT TOWARD KCNU DURING THE MORNING HOURS. EVEN
WITH THE PRECIPITATION...VFR IS EXPECTED TO PREVAIL. WIND GUSTS
HAVE DIMINISHED WITH LIGHT SOUTHEAST WINDS EXPECTED TO PREVAIL AS
A WARM FRONT LIFTS NORTHWARD INTO SOUTHERN KANSAS THIS AFTERNOON.
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MAY REDEVELOP ALONG AND
NORTH OF THE FRONT THIS AFTERNOON AND TONIGHT.
MWM
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT FRI AUG 3 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP TRENDS OVER THE NEXT 24 HOURS.
SYNOPSIS:
STRONG UPPER SHORTWAVE IS CURRENTLY APPROACHING THE NORTHERN
ROCKIES. MEANWHILE WATER VAPOR IMAGERY SHOWS THE DIRTY MONSOONAL
FLOW SPILLING MOISTURE OVER THE ROCKIES AND INTO THE HIGH PLAINS. AT
THE SURFACE THE FRONT IS LOCATED FROM EXTREME SOUTHEAST KS TO NEAR ENID
OK.
TODAY-TONIGHT:
STORMS DEVELOPED AROUND MIDNIGHT OVER SE KS IN AREA OF ISENTROPIC
LIFT ALONG THE 315K SURFACE. THE STORMS THEN FILLED BACK TO THE WEST
WHERE THE NAM SHOWED THE CAPPING THE WEAKEST ABOVE 850MB. MEANWHILE
THE MCS THAT DEVELOPED OVER EASTERN CO THU EVENING IS STILL HOLDING
TOGETHER AS IT PASSES JUST NORTH OF DDC. CURRENT THINKING IS THAT IT
WILL FOLLOW THE WEAKEST CAPPING WHICH WOULD TAKE IT NORTH OF HIGHWAY
400. WHILE WE DO FEEL IT WILL EXHIBIT AN OVERALL DECREASE IN INTENSITY
AND COVERAGE...DO THINK IT WILL AT LEAST HOLD TOGETHER LONG ENOUGH TO
AFFECT THE WESTERN PORTION OF THE FORECAST AREA.
EVEN IF THIS MCS DOES DIMINISH AS IT PASSES ACROSS THE FORECAST
AREA...IT WILL STILL PLAY HAVOC WITH TEMPS AND THE TIMING OF THE
FRONT. AT THIS POINT FEEL THE SHORT TERM MODELS MAYBE A BIT TOO
AGGRESSIVE IN LIFTING THE FRONT NORTH TODAY. WILL THEREFORE BACK-OFF
TEMPS A COUPLE DEGREES NORTH OF HIGHWAY 400. DO NOT HAVE ENOUGH
CONFIDENCE TO ADD OR REMOVE COUNTIES FROM THE CURRENT HEADLINE...SO
WILL LEAVE ALONE FOR NOW.
THE COLD FRONT WILL START ITS JOURNEY ACROSS THE CENTRAL PLAINS
TONIGHT. BUY MIDNIGHT IT IS EXPECTED TO STRETCH FROM EASTERN
NEBRASKA INTO EXTREME NORTHWEST KS...WITH THIS FEATURE ENTERING THE
NW FRINGES OF THE FORECAST AREA TOWARD SUNRISE. SCT CONVECTION
SHOULD DEVELOP SOUTH OF THE FRONT OVER CENTRAL AND EASTERN KS AS
MOISTURE TRANSPORT IN THE 850-700MB LEVEL INCREASES.
SAT-SUN:
BY SUNRISE SAT THE COLD FRONT IS EXPECTED TO STRETCH FROM NORTHEAST
KS INTO WEST-CENTRAL KS. WITH LACK OF STRONG/DEEP CONVERGENCE ALONG
THE FRONT...WOULD NOT BE SURPRISED TO SEE THE MORE WIDESPREAD PRECIP
BEHIND THE FRONT WHERE THE BETTER UPPER DYNAMICS WILL BE SITUATED.
WHILE CONFIDENCE IS HIGH THAT THERE WILL BE SOME SCATTERED ACTIVITY
NEAR THE FRONT AS IT PUSHES SOUTH ON SAT...HAVE LOW CONFIDENCE
ON HOW WIDESPREAD IT WILL BE. WITH SURFACE WINDS VEERING OUT AHEAD
OF THE FRONT...FEEL TEMPS COULD REALLY SOAR ACROSS SOUTH CENTRAL AND
ESPECIALLY SOUTHEAST KS. WOULD NOT BE SURPRISED TO SEE A FEW
LOCATIONS PUSH 110-111 ALONG THE KS-OK BORDER. WILL LET THE DAY
SHIFT MAKE THE CALL...BUT WOULD NOT BE SURPRISED IF THE CURRENT HEAT
HEADLINE WOULD NEED TO BE EXTENDED ANOTHER DAY.
BY SUNSET ON SAT THE FRONT SHOULD STRETCH ALONG THE KS-OK BORDER
WITH SOME SHOWERS AND STORMS ALONG AND JUST BEHIND THE FRONT.
CONFIDENCE IS HIGH THAT BY SUN MORNING THE PRECIP WILL BE SOUTH OF
THE FORECAST AREA.
MON-THU:
THROUGH THESE EXTENDED PERIODS THE UPPER RIDGE IS EXPECTED TO SHIFT
SLIGHTLY WEST WHICH WILL ALLOW THE FORECAST AREA TO REMAIN IN WEAK
DIFFLUENCE ALOFT. IN ADDITION BOTH THE ECMWF AND GFS ARE TRACKING
SOME SHORTWAVE ENERGY OUT OF THE NORTHERN ROCKIES AND ACROSS THE
MISSOURI VALLEY ON TUE NIGHT THROUGH WED. WILL KEEP SOME SMALL
PRECIP CHANCES FOR TUE NIGHT INTO WED WITH THE THINKING THAT THE
BEST CHANCES WOULD BE CLOSER TO THE UPPER DYNAMICS OVER NORTHEAST KS.
AS FAR AS TEMPS GO THROUGH THESE PERIODS...THEY WILL NOT BE AS
EXTREME AS SOUTHERN KS HAS SEEN OVER THE LAST SEVERAL DAYS...BUT
WILL STILL BE ABOVE NORMAL.
LAWSON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
BOUNDARY HAS STARTED ITS SLOW MIGRATION NORTHWARD EVIDENCED BY
INCREASED THETA-E CONVERGENCE AND WINDS VEERING TO THE SOUTHEAST IN
NORTHERN OKLAHOMA. FURTHER PROOF OF THIS IS THE SHOWERS WITH
ISOLATED THUNDER FORMING OVER SOUTHEAST KANSAS AND BUILDING
TOWARDS SOUTH CENTRAL KANSAS. LATEST HRRR GUIDANCE HAS THIS
CONVECTION LINGERING FROM HUT TO ICT AND CNU THROUGH ABOUT 12-13Z.
THE FOCUS SHIFTS TO FRIDAY AFTERNOON WHERE A VORT LOBE IS PROGGED
TO MOVE OFF THE HIGH PLAINS. THIS MAY SPARK OFF SOME SHOWERS AND
STORMS NEAR RSL AND SLN TOWARDS THE END OF THE TAF PERIOD. SINCE
CONFIDENCE ON DEVELOPMENT AND TIMING ISN`T TOO GREAT...HAVE
DECIDED TO LEAVE MENTION OF SHRA AND VCTS OUT FOR THOSE AREAS FOR
THE MOMENT.
ARL
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 102 79 100 69 / 30 20 30 40
HUTCHINSON 100 76 96 66 / 40 20 30 30
NEWTON 101 77 97 66 / 30 20 30 30
ELDORADO 102 78 99 68 / 30 20 30 40
WINFIELD-KWLD 106 80 106 71 / 20 20 30 40
RUSSELL 99 73 89 63 / 40 40 30 10
GREAT BEND 99 74 91 65 / 50 30 30 10
SALINA 100 75 91 64 / 50 30 30 20
MCPHERSON 100 75 95 65 / 50 20 30 20
COFFEYVILLE 108 80 106 71 / 20 10 20 40
CHANUTE 102 78 103 70 / 30 10 20 40
IOLA 101 78 101 69 / 30 10 20 40
PARSONS-KPPF 104 79 105 71 / 20 10 20 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069-
082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
953 AM EDT FRI AUG 3 2012
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH
PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND
STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 945 AM FRIDAY...MINOR ADJUSTMENTS WITH THE MORNING UPDATE
MAINLY TO REMOVE POPS FOR WESTERN ZONES AS CONVECTION HAS REMAINED
JUST WEST OF THE AREA...WITH HRRR AND MESOMODELS KEEPING PRECIP
OUT UNTIL THIS AFTERNOON. MINOR TWEAKS TO TEMPS/DEWPOINTS WITH
TEMPS REBOUNDING SLIGHTLY FASTER THAN FORECAST DUE TO LACK OF
CLOUD COVER AND FULL INSOLATION...STILL EXPECT LOWS IN THE LOWER
90S INLAND TODAY. WEAK UPPER LEVEL LOW TO THE SOUTH WILL GRADUALLY
LIFT OUT TO THE NORTH TODAY. 500 MB ANALYSIS INDICATES -10 C AT
00Z AND GIVEN THIS RATHER COLD AIR ALOFT AND SOME MODERATE
SURFACE BASED INSTABILITY THIS AFTERNOON WITH CAPES IN THE 1000
TO 1500 J/KG RANGE AND LIFTED INDICES OF -4 TO -6 C...WILL FORECAST
ISOLATED TSTMS ALONG INLAND AREAS ASSOCIATED WITH THE SEA BREEZE.
MAX TEMPERATURES AREA-WIDE SHOULD BE IN THE UPPER 80S TO LOWER
90S.
&&
.SHORT TERM /TONIGHT/...
AS OF 315 AM FRIDAY...THE UPPER AIR PATTERN STARTS TO CHANGE BY
LATER TONIGHT AS H5 RIDGE NEAR BERMUDA STARTS TO BUILD WEST WITH
STEADY HEIGHT RISES INDICATED OVERNIGHT. ANY CONVECTION SHOULD
SHIFT FROM THE LAND TO THE COASTAL AREAS AND OFFSHORE WATERS AND
WILL HAVE A SLIGHT CHANCE OVERNIGHT. MINIMUM TEMPERATURES TONIGHT
GENERALLY FROM 73 TO 78 DEGREES ACROSS THE REGION.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 245 AM FRI...CONTINUED WITH LITTLE CHANGES TO THE FORECAST OR
FORECAST REASONING THROUGH THE LONG TERM. HIGH PRESSURE ALOFT WILL
CONTINUE TO EXTEND INTO THE AREA FROM THE WESTERN ATLANTIC THROUGH
THE WEEKEND. THE BERMUDA HIGH ALSO STRENGTHENS OFFSHORE ALLOWING
MOIST SOUTHERLY FLOW TO CONTINUE THROUGH THE EXTENDED. EXPECT
ISOLATED TO SCATTERED DIURNAL CONVECTION INLAND AND ALONG THE SEA
BREEZE BOUNDARY THROUGH THE WEEKEND. LOW LEVEL THICKNESSES WILL
PERSIST AT 1415-1420 METERS...YIELDING TEMPS NEAR CLIMATOLOGY WITH
HIGHS IN THE LOW/MID 90S INLAND TO 80S ALONG THE COAST.
A FRONTAL BOUNDARY IS PROGGED TO APPROACH THE AREA FROM THE
NORTHWEST MON WITH MOIST SOUTHWESTERLY FLOW AND INCREASING LOW
LEVEL SHEAR AHEAD OF A ROBUST MID LEVEL SHORTWAVE. SCATTERED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE MON AFTERNOON/EVENING WITH
PWATS AGAIN BUILDING ABOVE 2 INCHES. 12Z OPERATIONAL ECMWF AND GFS
INDICATE THE FRONT WILL STALL JUST WEST OF THE REGION ACROSS THE
CENTRAL PIEDMONT AND MID ATLANTIC STATES LATE MON THROUGH THURS
WHILE AN UPPER TROUGH BECOME RE-ESTABLISHED ACROSS THE EASTERN
CONUS. 00Z/12Z ECMWF SUGGEST A WEAK SURFACE LOW WILL FORM ALONG
THE FRONT TUES NIGHT AND PUSH NE OFF THE MID ATLANTIC COAST WED
INTO WED NIGHT. WILL MAINTAIN CHANCE POPS TUES THROUGH THURS WITH
THE UPPER TROUGH AND STALLED SURFACE FRONT CONTINUING ACROSS THE
REGION WHILE WEAK SHORTWAVES MOVE THROUGH THE FLOW ALOFT. LOW
LEVEL THICKNESSES WILL REMAIN AROUND 1415 METERS MON THROUGH THURS
HOWEVER GREATER CLOUD COVER AND PRECIP MAY MODERATE TEMPS FROM
REACHING ABOVE THE 90 DEGREE MARK EACH DAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 06Z SATURDAY/...
AS OF 650 AM FRIDAY...FOG AND STRATUS HAS FAILED TO MATERIALIZE
THIS MORNING WITH THE EXCEPTION OF SOME 4 MILE VSBYS AT KOAJ. THIS
FOG...AND ANY FOG THAT DEVELOPS AT THE OTHER TAF SITES...SHOULD
DISSIPATE QUICKLY WITH VFR CONDITIONS EXPECTED THROUGH TODAY AND
INTO TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS OF 245 AM FRI...PREDOMINANT VFR AVIATION CONDITIONS EXPECTED
THROUGH THE EXTENDED. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE IN DIURNAL CONVECTION EACH DAY. SOUTHWESTERLY SURFACE
FLOW WILL PERSIST INTO EARLY NEXT WEEK WITH HIGH PRESSURE ANCHORED
OFFSHORE. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST MON
NIGHT INTO TUES WITH SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF
AND ALONG THE BOUNDARY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 950 AM FRIDAY...LATEST SURFACE AND BUOY OBSERVATIONS
INDICATE LIGHT SE BREEZE 4-8 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET
AT 8-9 SECONDS. A LIGHT S/SW WINDS AT 10 KNOTS OR LESS WITH A
GENTLE SOUTHEAST SWELL COMPONENT WILL MAKE FOR ANOTHER 24 HOURS OF
BENIGN MARINE CONDITIONS TODAY AND TONIGHT. WAVEWATCH AND LOCAL
SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TODAY AND
TONIGHT AND WINDS WILL GENERALLY NOT EXCEED ABOUT 10 OR 12 KNOTS
FROM THE SOUTH TO SOUTHWEST THROUGH EARLY SATURDAY MORNING.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS OF 245 AM FRI...GOOD BOATING CONDITIONS EXPECTED SAT AND SUN WITH
THE BERMUDA HIGH STRENGTHENING OVER THE WESTERN ATLANTIC BRINGING
SLY WINDS ACROSS THE WATERS. SPEEDS WILL RANGE GENERALLY 10-15
KNOTS WITH SEAS 2 TO 3 FT. ISOLATED SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE THROUGH THE WEEKEND AS WELL.
GRADIENT BEGINS TO TIGHTEN LATE SUN AND MON AS FRONTAL SYSTEM
APPROACHES FROM THE NW AND EXPECT WINDS TO INCREASE TO AROUND
15-20 KT...MAINLY ACROSS THE NORTHERN AND CENTRAL WATERS.
SWAN/WAVEWATCH HAVE BACKED OFF SLIGHTLY WITH SEAS EARLY NEXT
WEEK...NOW ONLY BUILDING ABOUT A FOOT OR SO...UP TO 4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC/DAG
SHORT TERM...CTC
LONG TERM...SK/DAG
AVIATION...CTC/SK/DAG
MARINE...CTC/SK/DAG
AREA FORECAST DISCUSSION
NWS NEW YORK NY
158 PM EDT FRI AUG 3 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE
TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS
OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY
ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON
TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA
FOR THE MIDDLE OF THE NEW WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WARM TO HOT TEMPS...HIGH DEW POINTS IN THE 70S HAVE RESULTED IN
SFC BASED CAPES AROUND 3K TO 4K J/KG ACROSS LONG ISLAND. ISOLATED
SHOWERS AND TSTMS COULD CONTINUE TO FORM ON THE SEA BREEZE
BOUNDARY...AND THE MAIN FORMATION SHOULD BE ACROSS THE INTERIOR AS
THE AFTERNOON PROGRESSES. THE OTHER TRIGGER WILL BE DIFFERENTIAL
HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY
UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE
STORMS.
WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND
HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES
ALREADY AROUND 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR
THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS
BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR
BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL
VALUES.
TEMPS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO
95 NYC METRO AND THE INTERIOR.
THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH
A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH
SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL
ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS...
RESULTING IN PRETTY MUCH A WASH.
594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST
BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH
SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD
BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR.
ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8
DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE
PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY
TROUGHING.
A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES
ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH
NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT
WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO
SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION
SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE
COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY.
ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH
WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL
OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING
THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS
POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS
TO STRENGTHEN.
INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT
WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND
APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF
STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON
HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE
AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO
WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT
AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION
WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST
OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED
ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW
BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG
TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY
AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY
STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR
LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID
LEVELS WINDS.
INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT
CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND
PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION.
SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS
POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD
BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING
TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS
NEARLY ALIGN WITH THE FRONT.
COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY
MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E.
GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON
AFTERNOON/NIGHT.
HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON
TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH
WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S.
UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF
THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT
SWINGS THROUGH ON THURSDAY.
TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF
PERIOD WITH MAINLY VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME
EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO
IMPROVE TO VFR BY 13Z-15Z.
AN ISOLATED THUNDERSTORM IS POSSIBLE AT ANY TIME FROM THIS AFTERNOON
INTO THE EARLY EVENING. ANY ADDITIONAL DEVELOPMENT WOULD LIKELY BE ALONG
THE SEA BREEZE CONVERGENCE OVER LONG ISLAND OR ACROSS THE LOWER
HUDSON VALLEY. HRRR KEEPS LOOKING TO BRING SOME ACTIVITY ACROSS
THE LOWER HUDSON VALLEY AND WESTERN NJ ACROSS NYC LATER THIS
AFTERNOON HOWEVER STILL NOT CONFIDENT ENOUGH CONFIDENCE TO INCLUDE
ANY ACTIVITY IN THE TAFS. CIRRUS STREAKING EASTWARD ACROSS PA
ATTM MAY ALSO HELP TO INHIBIT ADDITIONAL CU DEVELOPMENT IN THE
IMMEDIATE VICINTY OF THE TERMINALS.
WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD.
DURING THE AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS
MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND
VARIABLE ONCE AGAIN TONIGHT.
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: FORECAST ON TRACK. NO UNSCHEDULED
AMENDMENTS ANTICIPATED.
KLGA FCSTER COMMENTS: FORECAST ON TRACK. NO UNSCHEDULED
AMENDMENTS ANTICIPATED.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND
SHIFTS.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND
SHIFTS.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND
SHIFTS.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND
SHIFTS. ALSO NEARBY ISOLATED SHOWERS MAY REQUIRE AMENDMENTS IF
THEY PASS NEAR THE AIRPORT.
OUTLOOK FOR 18Z SAT THROUGH WED...
.SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING
TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE.
.SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS
POSSIBLE WITH AN APPROACHING COLD FRONT.
.MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING.
.TUE/WED...VFR.
&&
.MARINE...
SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH
PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE
EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON
AND EVENING DUE TO SEA BREEZES.
SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN
THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY
MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN
WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO
DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY
TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS.
COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL
BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND
THUNDERSTORM WIND GUSTS EXCEEDING 34 KT.
SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE
WEEK.
&&
.HYDROLOGY...
ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL
NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY
AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC.
THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON
INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A
THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM
BACK BUILDING OR TRAINING STORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NV/DW
NEAR TERM...DW/PW
SHORT TERM...DW
LONG TERM...NV
AVIATION...IRD
MARINE...NV/DW/PW
HYDROLOGY...NV/DW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
200 PM EDT FRI AUG 3 2012
.SYNOPSIS)...
18Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE FLORIDA PENINSULA
CONTINUES TO RESIDE UNDERNEATH A SUBTLE WEAKNESS IN THE HEIGHT
FIELDS TO THE EAST OF AN IMPRESSIVE AND DOMINANT UPPER LEVEL RIDGE
ACROSS THE SOUTHERN PLAINS. THIS UPPER RIDGE IS ACTUALLY ONE OF THE
MORE VISUALLY IMPRESSIVE ANTICYCLONES ON WV IMAGERY THAT THIS
FORECASTER HAS SEEN...WITH A VERY SYMMETRIC LOOK OF DRY
AIR/SUPPRESSION AT ITS CORE AND RINGED BY A MID/UPPER LEVEL MOISTURE
BELT.
AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS SHIFTED NORTHWARD
OVER THE PAST 24 HOURS AND IS NOW ALIGNED OVER THE NORTHERN FL
PENINSULA/NE GULF OF MEXICO. ROTATING AROUND THE SOUTHERN PERIPHERY
OF THIS RIDGE WE FIND A RATHER WELL DEFINED INVERTED TROUGH/TROPICAL
WAVE FEATURES CROSSING THE BAHAMAS AND APPROACHING THE FL EAST
COAST.
&&
.SHORT TERM (THIS EVENING THROUGH SUNDAY NIGHT)...
LATE AFTERNOON/EVENING...THE CURRENT THINKING ON THE MOST LIKELY
CONVECTIVE CYCLE THROUGH THE EVENING IS FOR ISOLATED-WDLY SCT
SHOWERS/STORMS EARLY/MID AFTERNOON MOVING SLOWLY INLAND FROM THE
I-75 CORRIDOR. THEREAFTER...WITH THE APPROACH OF THE SURFACE WAVE
FROM THE EAST...WILL SEE OUR 1000-700MB FLOW TRANSITION TO A MORE
EASTERLY DIRECTION. THIS SYNOPTIC INFLUENCE SHOULD HELP PROPEL THE
EAST COAST SEA-BREEZE ACROSS THE PENINSULA BY EARLY EVENING. THE
INTERACTION OF BOTH SEA-BREEZES SHOULD BE GREATEST FROM TAMPA BAY
SOUTHWARD WHERE A SECOND ROUND OF CONVECTION MAY ACTUALLY PUSH BACK
TOWARD THE WEST COAST WITH TIME. MID-LEVEL CONVECTIVE POTENTIAL IS
ACTUALLY VERY FAVORABLE FOR DEEP CONVECTION WITH THETAE VALUES IN
THE LOWER 330S. OUR LOCAL HIRES GUIDANCE ALONG WITH SEVERAL OF THE
NATIONAL HI-RES MEMBERS ARE SHOWING SOMETHING SIMILAR TO THIS
SCENARIO.
REST OF THE OVERNIGHT...DEVELOPING EASTERLY FLOW WILL PUSH ANY
LINGERING CONVECTION OFFSHORE ALLOWING FOR A MOSTLY DRY OVERNIGHT
PERIOD AFTER 02-03Z. NOT IMPOSSIBLE THAT A FEW SHOWERS MOVING ASHORE
ALONG THE FL EAST COAST WITHIN THE EASTERLY FLOW COULD REACH FAR
EASTERN PORTIONS OF THE AREA...HOWEVER MOST OF THIS ACTIVITY SHOULD
DISSIPATE SHORTLY AFTER MOVING INLAND.
SATURDAY/SATURDAY NIGHT...
TROUGH/WAVE PASSES OVER THE CENTRAL/SOUTHERN PENINSULA AND REACHES
THE WESTERN COAST BY EARLY EVENING. THE COMBINATION OF INCREASING
COLUMN MOISTURE AND ENHANCED LOW LEVEL FOCUS ASSOCIATED WITH THIS
FEATURE IS LIKELY TO RESULT IN A GOOD COVERAGE OF SHOWERS/STORMS
DURING THE AFTERNOON/EVENING HOURS. CURRENT GRIDS SHOWING 40-50%
POPS NORTH OF TAMPA BAY AND LIKELY 60% POPS FURTHER SOUTH. THE
EASTERLY FLOW SHOULD ALSO HELP KEEP THE MAIN CONVECTIVE AXIS FROM
MOVING INLAND AND AWAY FROM THE COAST. THEREFORE...WILL KEEP EQUAL
CHANCES FOR RAIN THROUGH THE AFTERNOON FOR BOTH COASTAL AND INLAND
ZONES. TEMPERATURES WILL BE HIGHLY DEPENDENT ON JUST HOW FAST THE
CONVECTION GETS ACTIVE. DO ANTICIPATE QUITE A BIT OF DEBRIS CLOUD
COVER BY THE END OF THE DAY. WILL ALLOW TEMPS TO REACH THE LOWER 90S
FOR MOST LOCATIONS...HOWEVER ACTUAL HIGHS MAY BE A BIT LOWER.
EVENING SHOWER AND STORMS WILL MIGRATE BACK OFFSHORE WITHIN THE
EASTERLY FLOW BY THE LATER EVENING HOURS. MOST INLAND LOCATIONS WILL
SEE A DRY OVERNIGHT PERIOD...WHILE PLENTY OF SHOWERS/STORMS ARE
LIKELY TO BE ONGOING OVER THE COASTAL WATERS. ONE THING TO
MENTION...AND ONE POTENTIAL ISSUE WITH THE FORECAST WOULD BE IF THE
NAM SOLUTION WERE TO VERIFY. THE NAM IS CONSOLIDATING THE SURFACE
WAVE MORE AS IT APPROACHES THE EAST COAST AND ACTUALLY CLOSING OFF A
LOW. THIS PATTERN SLOWS THE OVERALL PROGRESS AND MOISTURE INFLUX.
THE RESULT WOULD A DRIER FORECAST...ESPECIALLY SINCE THE LACK OF
EASTERLY FLOW WOULD LESSEN THE OVERALL CONVERGENCE. AT THIS
TIME...THIS SOLUTION IS AN OUTLIER AND WAS NOT CONSIDERED WITH THIS
FORECAST PACKAGE. IT IS HARD TO ARGUE WITH A GUIDANCE CONSENSUS
WHICH INCLUDES THE GFS/ECMWF/CMC AND SREF.
SUNDAY...ANOTHER ACTIVE CONVECTIVE DAY APPEARS ON TAP. THE MAIN AXIS
OF THE TROPICAL WAVE WILL HAVE MOVED OFFSHORE INTO THE EASTERN
GULF...HOWEVER STILL SOME ENHANCED FOCUS AND A MOIST COLUMN WILL
KEEP THE ATMOSPHERE FAVORABLE FOR DEEP CONVECTION. A 1000-700MB LOW
LEVEL FLOW WILL ALSO KEEP THE BEST LOW LEVEL CONVERGENCE ALIGNED
WITH THE WEST COAST SEA-BREEZE. OVERALL WE ARE NOT ANTICIPATING A
WASHOUT OF A WEEKEND...BUT THOSE WITH OUTDOOR PLANS THE NEXT COUPLE
OF DAYS SHOULD PREPARE FOR AT LEAST SOME RAINFALL.
&&
.LONG TERM (MONDAY-THURSDAY)...
AN U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE
SOUTHERN PLAINS THROUGH THE PERIOD. SURFACE HIGH PRESSURE OVER THE
WESTERN ATLANTIC WITH THE RIDGE AXIS NORTH OF FLORIDA WILL ALSO
PERSIST THROUGH THE PERIOD. EASTERLY BOUNDARY LAYER FLOW WILL HOLD
THE WEST COAST SEA BREEZE NEAR THE COAST WITH AFTERNOON BOUNDARY
COLLISIONS OVER WEST CENTRAL AND SOUTHWEST FLORIDA. DEEP TROPICAL
MOISTURE OVER THE REGION WILL ALLOW NUMEROUS SHOWERS AND
THUNDERSTORMS TO DEVELOP MONDAY AND TUESDAY AFTERNOONS. A FEW PULSE
SEVERE STORMS ARE POSSIBLE EACH DAY.
WILL HAVE TO MONITOR PROGRESS OF TROPICAL STORM ERNESTO NEAR THE
WINDWARD ISLANDS AS CURRENT FORECAST TRACKS THE STORM INTO THE
WESTERN CARIBBEAN TUESDAY AND WEDNESDAY. SUBSIDENCE AROUND THE
PERIPHERY OF THE TROPICAL SYSTEM WILL INCREASE OVER THE FORECAST
AREA WEDNESDAY AND THURSDAY WITH DECREASING AREAL COVERAGE OF
AFTERNOON THUNDERSTORMS WITH INCREASING DAYTIME TEMPERATURES.
DEPENDING ON STRENGTH OF ERNESTO...STRONG SUBSIDENCE AND EASTERLY
BOUNDARY LAYER FLOW ACROSS WEST CENTRAL FLORIDA COULD ALLOW
AFTERNOON TEMPERATURES TO CLIMB INTO THE MID 90S IN MANY AREAS
WEDNESDAY AND THURSDAY.
&&
.AVIATION...
HIGHER CONFIDENCE NOW IN THUNDERSTORM ACTIVITY IMPACTING
PGD..FMY...RSW AND LAL TAF SITES. TPA...PIE AND SRQ MAY SEE IMPACTS
LATER IN THE AFTERNOON OR EVEN INTO THE EARLY EVENING AS EAST COAST
ACTIVITY PUSHES WESTWARD. VFR OVERNIGHT AND THROUGH MID-DAY SATURDAY.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL CONTINUE TO MIGRATE NORTHWARD IN
RESPONSE TO THE APPROACH OF A TROPICAL WAVE FROM THE EAST. THIS
TROUGH WILL CROSS THE FL PENINSULA INTO THE SOUTHEAST GULF OF MEXICO
TONIGHT AND SATURDAY AND THEN REMAIN OVER THE CENTRAL AND EASTERN
GULF THROUGH THE REMAINDER OF THE WEEKEND. WINDS WILL BECOME MORE
EASTERLY WITH TIME AND ARE GENERALLY EXPECTED TO REMAIN BELOW
HEADLINE CRITERIA...HOWEVER THE PRESENCE OF THE SURFACE TROUGH WILL
LIKELY INCREASE THE COVERAGE OF SHOWERS AND STORMS OVER THE FORECAST
WATERS.
&&
.FIRE WEATHER...
AN INFLUX OF LOW LEVEL MOISTURE ASSOCIATED WITH A PASSING TROPICAL
WAVE WILL KEEP RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS
INTO THE EARLY PORTION OF NEXT WEEK...ALONG WITH DECENT CHANCES FOR
MAINLY AFTERNOON AND EVENING SHOWERS AND STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 92 77 91 / 30 50 20 50
FMY 76 93 76 93 / 30 60 30 50
GIF 74 94 75 94 / 30 50 20 50
SRQ 75 93 75 92 / 30 60 20 50
BKV 71 93 74 92 / 30 50 20 50
SPG 79 92 79 91 / 30 50 20 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...JILLSON
LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 PM CDT FRI AUG 3 2012
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING
THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED
COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY
FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST
FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY
ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME
REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND
HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE
DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD
SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT
HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT
CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE
AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY
IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED
SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY
ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR
PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP
IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL
NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO
MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS
THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK
EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE
EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY
LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY
EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT
LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE
CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS
SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE
FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS
CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE
FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS
NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE
FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID
80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO
90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE
DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN
ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS
MONDAY NIGHT ACROSS MUCH OF THE CWA.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK
AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A
COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN
COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING.
READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT
NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY.
SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK
SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH
THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST
FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE
INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW
CONTINUING BEYOND THE FORECAST PERIOD.
&&
.AVIATION...03/18Z
INCREASING CLOUDS EXPECTED THROUGHOUT THE PERIOD...MAINLY HIGH
CLOUDS IN THE CRITICAL TAF PERIOD AS UPPER LEVEL SYSTEM SLIDES
EASTWARD THROUGH THE DAKOTAS INTO MINNESOTA. AN ASSOCIATED COLD
FRONT WILL SWEEP THROUGH THE STATE SATURDAY INTO JUST BEYOND THE
CURRENT TAF PERIOD ALLOWING WINDS TO SHIFT AROUND TO THE NORTHWEST
BEHIND THE FRONT. THIS SYSTEM WILL ALSO BRING CHANCES FOR
THUNDERSTORMS TO THE AREA...WITH THE GREATEST CERTAINTY AT KFOD AND
KMCW AT THIS TIME THROUGH 18Z SATURDAY. THEREFORE HAVE HIGHLIGHTED
WITH A VCSH AWAITING FURTHER REFINEMENT AS THE SYSTEM APPROACHES.
GREATER CHANCES FOR EASTERN/SOUTHERN TAF SITES FOR PRECIP JUST
BEYOND THE CURRENT TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MJB
LONG TERM...COGIL
AVIATION...MJB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1215 PM CDT FRI AUG 3 2012
.SHORT TERM /TODAY/...
MOST IMMEDIATE CONCERN INVOLVES FATE OF SMALL MCS ALONG SD/NE
BORDER. CLUSTER IS ELEVATED...MOST LIKELY ALONG 310K ISENT
SURFACE...WITHIN STRONG MLCIN. RAP SUGGESTS MOISTURE TRANSPORT AND
CONVERGENCE ALONG THIS SURFACE WILL MAINTAIN ITSELF TO OUR WEST WITH
LITTLE MOVEMENT INTO THE MORNING SO WILL LEAVE OUR FORECAST DRY
TODAY. RECENT UPSTREAM DEVELOPMENT SUPPORTS THIS SCENARIO AS WELL.
NONE OF THE EXPLICIT OR PARAMETERIZED MODEL GUIDANCE SUGGESTS THIS
WILL MAINTAIN ITSELF EASTWARD INTO IA EITHER.
NEXT CONCERN WILL BE TEMPS. FORECAST SOUNDINGS AND LOW LEVEL TEMP
CHANGE FROM YESTERDAY SUGGEST HIGHS MAY BE A FEW DEGREES WARMER
WHICH MAKES SENSE AS LOW LEVEL WINDS SLOWLY VEER AND INCREASE
SLIGHTLY. TRIMMING A FEW DEGREES OFF THE OFTEN OVERAGGRESSIVE TOO
SUPER ADIABATIC NAM SUGGESTS HIGHS IN THE MID/UPPER 90S. LOWERING
DEWPOINTS WITH MIXING THIS AFTERNOON WILL KEEP HEAT INDICES
PLUS/MINUS A FEW DEGREES OF THE ACTUAL TEMPERATURE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
MODELS ARE A LITTLE SLOWER WITH THE SHORTWAVE TONIGHT ALSO THE BEST
FORCING. AS A RESULT A BACKED OFF ON POPS THIS EVENING AND ON AREAL
EXTENT OF POPS OVERNIGHT. UPPER TROUGH AND SURFACE COLD FRONT MOVE
THROUGH MOST OF CENTRAL IOWA DURING THE MORNING INTO EARLY
AFTERNOON. WHILE THE SYSTEM IS DYNAMIC...IT MOVES THROUGH MUCH OF
THE CWA BEFORE PEAK HEATING SO THE BEST INSTABILITY WON/T BE
REALIZED UNTIL THE SYSTEM IS MOSTLY EAST OF THE CWA. THE
INTERESTING THING TO FORECAST FOR SATURDAY WILL BE TEMPS. SOUNDINGS
SHOW THE DAYS HIGHS OCCURRING AROUND 18Z THEN BEGINNING TO FALL
OFF. CLOUDS/PRECIP WILL IMPACT THE CWA AND THERE WILL LIKELY BE A
PRETTY BIG THERMAL GRADIENT ACROSS THE STATE WITH MID 70S NORTHWEST
AND MID 90S SOUTHEAST. SUNDAY WILL SEEM LIKE FALL WITH HIGHS IN THE
70S AND 80S. THIS WILL BE SHORT LIVED HOWEVER AS THE UPPER RIDGE
REBUILDS OVER THE WEST EARLY NEXT WEEK. WHILE TEMPS ARE FORECAST TO
WARM BACK UP INTO THE 80S AND 90S...IT WILL NOT BE AS WARM AS IT HAS
BEEN. NUMEROUS SHORTWAVES WILL RIDE ATOP THE RIDGE ACROSS IOWA BUT
TIMING AND STRENGTH OF THESE WAVES LEAVES THE POP FORECAST DIFFICULT
AT BEST. MODELS DIFFER ON INTENSITY AND TIMING BUT IN THE TUESDAY
NIGHT/WEDNESDAY TIMEFRAME ONE WAVE LOOKS LIKE IT WILL AFFECT THE
WESTERN PORTION OF THE FORECAST AREA. ANOTHER STRONGER WAVE MOVES
IN LATE IN THE EXTENDED...AROUND FRIDAY/FRIDAY NIGHT. POPS WERE HIT
HARDEST DURING THIS TIME BUT WITH MODEL DISCREPANCIES AND WEAKER
WAVES IN BETWEEN THE AFOREMENTIONED DAYS...I DID NOT FEEL SLIGHT
POPS WERE WARRANTED. HOWEVER...AS RESOLUTION BECOMES BETTER...WE
WILL LIKELY SEE OTHER PERIODS OF PRECIP DURING THE EXTENDED.
&&
.AVIATION...03/18Z
INCREASING CLOUDS EXPECTED THROUGHOUT THE PERIOD...MAINLY HIGH
CLOUDS IN THE CRITICAL TAF PERIOD AS UPPER LEVEL SYSTEM SLIDES
EASTWARD THROUGH THE DAKOTAS INTO MINNESOTA. AN ASSOCIATED COLD
FRONT WILL SWEEP THROUGH THE STATE SATURDAY INTO JUST BEYOND THE
CURRENT TAF PERIOD ALLOWING WINDS TO SHIFT AROUND TO THE NORTHWEST
BEHIND THE FRONT. THIS SYSTEM WILL ALSO BRING CHANCES FOR
THUNDERSTORMS TO THE AREA...WITH THE GREATEST CERTAINTY AT KFOD AND
KMCW AT THIS TIME THROUGH 18Z SATURDAY. THEREFORE HAVE HIGHLIGHTED
WITH A VCSH AWAITING FURTHER REFINEMENT AS THE SYSTEM APPROACHES.
GREATER CHANCES FOR EASTERN/SOUTHERN TAF SITES FOR PRECIP JUST
BEYOND THE CURRENT TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BSS
LONG TERM...FAB
AVIATION...MJB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1153 AM MDT FRI AUG 3 2012
.UPDATE...
ISSUED AT 1145 AM MDT FRI AUG 3 2012
JUST COMPLETED ANOTHER UPDATE. MAIN THING WAS TO REFINE THE
THUNDERSTORM AREA THIS AFTERNOON. RIGHT NOW IT LOOKS LIKE THE
EASTERN PORTION OF THE FORECAST AREA MAY REMAIN CAPPED.
HOWEVER...THERE IS AN OLD OUTFLOW BOUNDARY IN THAT AREA. SURFACE
TROUGH HAS SET UP IN THE WESTERN PORTION OF THE AREA WHERE THE
LEAST CAP IS. PLAN ON ADJUSTING TONIGHTS AND TOMORROWS
PRECIPITATION. OTHERWISE TODAYS MAXES LOOK GOOD.
UPDATE ISSUED AT 856 AM MDT FRI AUG 3 2012
JUST COMPLETED AN UPDATE. FIRST THING WAS TO ADJUST THE CLOUD
COVER DOWN TO NEXT TO NOTHING THIS MORNING. MAIN CHANGE WAS FOR
THE WINDS...MAINLY FOR TONIGHT AND TOMORROW. OUTFLOW BOUNDARY OR
WEAK FRONT OVER THE EASTERN OF THE AREA SHOULD PULL AWAY. THE RUC
AND NAM CATCHING THIS PLUS THE LOCATION OF THE INCOMING FRONT. RUC
AND ESPECIALLY NAM WAS CATCHING THE SURFACE LOW AND TROUGH
POSITION FROM WESTERN NEBRASKA INTO EASTERN COLORADO THE BEST AND
WAS THE FARTHEST SOUTH WITH IT.
SO WENT AHEAD AND ADJUSTED WINDS WITH THE NAM. NAM BRINGS THE
FRONT IN A LITTLE FASTER AND CONSIDERING WHAT AM SEEING WITH THE
INITIAL SURFACE AND UPPER AIR ANALYSIS THIS MORNING...THIS LOOKS
VERY REASONABLE. FRONT PUSHES INTO THE EXTREME NORTHWEST PORTION
OF THE AREA AT 06Z AND THEN THROUGH THE REST OF THE AREA BY 12Z.
CONSIDERING THE COLD AIR AM SEEING WITH THIS SYSTEM...THE PRESSURE
GRADIENT AND RATHER HIGH 3 HOUR PRESSURE RISES BEHIND...INCREASED
THE WINDS BEHIND THE FRONT. COULD GET WINDY FOR A FEW HOURS BEHIND
THE FRONT.
AM GETTING MIXED SIGNALS ON WHERE THE THUNDERSTORMS ARE GOING TO
DEVELOP THIS AFTERNOON. HRRR IS DEVELOPING STORMS IN THE FAR EAST
WITH THE RUC AND NAM DEVELOPING STORMS NEAR THE TROUGH NEAR/OVER
THE WESTERN PORTION OF OUR AREA. CURRENT GRIDS CAPTURE BOTH OF
THESE SCENARIOS FOR AND WILL LEAVE AS IS FOR NOW. PLAN ON LEAVING
MAXES AS IS FOR NOW AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 200 AM MDT FRI AUG 3 2012
IT APPEARS THAT WEATHER DISTURBANCE CURRENTLY GENERATING THUNDERSTORMS
IN NORTHERN NEW MEXICO WILL EMERGE OVER THE SOUTHERN PORTION OF
THE FORECAST AREA BY NOON TODAY THEN INCREASE IN COVERAGE OVER
AREAS GENERALLY EAST OF THE CO/KS BORDER BY THE END OF THE DAY.
THIS AREA OF PRECIPITATION SHOULD MOVE EAST BY MIDNIGHT TONIGHT WITH
ANOTHER CHANCE ACROSS THE AREA AFTER MIDNIGHT AS A COLD FRONT
MOVES THROUGH. THIS AREA OF PRECIP WILL MOVE SOUTHEAST DURING THE
DAY SATURDAY AND BY THE END OF THE DAY BE NEAR ARE
SOUTHERN/SOUTHEASTERN FORECAST AREA OR SLIGHTLY OUTSIDE OF IT.
SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BE DRY AS THE MOISTURE
SOURCE AND ANY FORCING REMAIN SOUTH AND WEST OF THE AREA.
HIGH TEMPERATURES TODAY IN THE 90S WITH AROUND 102 IN THE HILL
CITY AREA. ON SATURDAY NOTICEABLY COOLER TEMPERATURES IN THE MID
70S NEAR FLAGLER TO MID 80S NEAR HILL CITY WITH GUSTY NORTH TO
NORTHEAST WINDS. SLIGHTLY WARMER AND CLOSE TO NORMAL ON SUNDAY
WITH UPPER 80S TO MID 90S.
WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT LOW TEMPERATURES SHOULD
DROP INTO THE LOW TO MID 50S. RECORD OR NEAR RECORD LOW
TEMPERATURES ARE POSSIBLE IN HILL CITY (54 IN 1974)...YUMA
(50)...AND COLBY (51).
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 200 AM MDT FRI AUG 3 2012
PRECIPITATION CHANCES RETURN TO THE AREA MONDAY NIGHT THROUGH
WEDNESDAY NIGHT AS WEATHER DISTURBANCES WITHIN MONSOONAL MOISTURE
MOVE ACROSS THE AREA. THURSDAY APPEARS TO BE DRY. HIGH
TEMPERATURES THROUGH THE PERIOD GENERALLY IN THE 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1145 AM MDT FRI AUG 3 2012
LOOKS LIKE THUNDERSTORMS WILL NOT AFFECT EITHER TAF SITE UNTIL THE
EVENING HOURS. WITH THE STORMS...IT LOOKS LIKE CONDITIONS WILL
REMAIN VFR UNLESS A STRONG STORM COMES OVER THE TOP OF THEM. THESE
STORMS WILL BE IN ADVANCE OF A STRONG COLD FRONT WHICH SHOULD
LOOKS TO MOVE THROUGH BOTH SITES IN THE 06Z TO 08Z TIME FRAME WITH
VERY GUSTY NORTHERLY WINDS EXPECTED. BEHIND THE FRONT IT IS
LOOKING MORE LIKELY THAT MVFR CEILINGS WILL OCCUR. AFTER THE MAIN
PUSH OF THE FRONT IS THROUGH PRECIPITATION AND CLOUDS SHOULD END
QUICKLY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...99
LONG TERM...99
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WICHITA KS
1219 PM CDT FRI AUG 3 2012
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MCV OVER EASTERN KS WILL CONTINUE TO MOVE EASTWARD INTO MISSOURI
LATER THIS AFTERNOON...WITH SHOWERS/T-STORMS DIMINISHING IN
SOUTHEAST KS. FLOW WILL BECOME LIGHT SOUTH-SOUTHEASTERLY TONIGHT
AHEAD OF APPROACHING COLD FRONT. ALTHOUGH MODELS WERE IN GOOD
AGREEMENT ON FRONTAL TIMING...USED THE NAM FOR ITS STRONGER WIND
GUSTS FROM NORTH BEHIND FROPA. FRONT SHOULD MOVE THROUGH CENTRAL
KS SATURDAY MORNING...AND SOUTH CENTRAL AND SOUTHEAST KS SATURDAY
PM/EVE. THUNDERSTORMS...AT LEAST A SCATTERED LINEAR
COVERAGE...APPEAR POSSIBLE WITH THE FRONTAL PASSAGE PARTICULARLY
SATURDAY PM/EVE AS STRONG HEATING DEVELOPS AHEAD OF IT.
JMC
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT FRI AUG 3 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MCV FROM EARLIER CONVECTION ACROSS WEST CENTRAL KANSAS CONTINUES
TO SPIN OVER CENTRAL KANSAS BRINGING LIGHT RAIN SHOWERS TO KRSL
AND KSLN. ADDITIONAL ACTIVITY WAS DEVELOPING OVER NORTHERN
OKLAHOMA AND MAY DRIFT TOWARD KCNU DURING THE MORNING HOURS. EVEN
WITH THE PRECIPITATION...VFR IS EXPECTED TO PREVAIL. WIND GUSTS
HAVE DIMINISHED WITH LIGHT SOUTHEAST WINDS EXPECTED TO PREVAIL AS
A WARM FRONT LIFTS NORTHWARD INTO SOUTHERN KANSAS THIS AFTERNOON.
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MAY REDEVELOP ALONG AND
NORTH OF THE FRONT THIS AFTERNOON AND TONIGHT.
MWM
PREV DISCUSSION... /ISSUED 322 AM CDT FRI AUG 3 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP TRENDS OVER THE NEXT 24 HOURS.
SYNOPSIS:
STRONG UPPER SHORTWAVE IS CURRENTLY APPROACHING THE NORTHERN
ROCKIES. MEANWHILE WATER VAPOR IMAGERY SHOWS THE DIRTY MONSOONAL
FLOW SPILLING MOISTURE OVER THE ROCKIES AND INTO THE HIGH PLAINS. AT
THE SURFACE THE FRONT IS LOCATED FROM EXTREME SOUTHEAST KS TO NEAR ENID
OK.
TODAY-TONIGHT:
STORMS DEVELOPED AROUND MIDNIGHT OVER SE KS IN AREA OF ISENTROPIC
LIFT ALONG THE 315K SURFACE. THE STORMS THEN FILLED BACK TO THE WEST
WHERE THE NAM SHOWED THE CAPPING THE WEAKEST ABOVE 850MB. MEANWHILE
THE MCS THAT DEVELOPED OVER EASTERN CO THU EVENING IS STILL HOLDING
TOGETHER AS IT PASSES JUST NORTH OF DDC. CURRENT THINKING IS THAT IT
WILL FOLLOW THE WEAKEST CAPPING WHICH WOULD TAKE IT NORTH OF HIGHWAY
400. WHILE WE DO FEEL IT WILL EXHIBIT AN OVERALL DECREASE IN INTENSITY
AND COVERAGE...DO THINK IT WILL AT LEAST HOLD TOGETHER LONG ENOUGH TO
AFFECT THE WESTERN PORTION OF THE FORECAST AREA.
EVEN IF THIS MCS DOES DIMINISH AS IT PASSES ACROSS THE FORECAST
AREA...IT WILL STILL PLAY HAVOC WITH TEMPS AND THE TIMING OF THE
FRONT. AT THIS POINT FEEL THE SHORT TERM MODELS MAYBE A BIT TOO
AGGRESSIVE IN LIFTING THE FRONT NORTH TODAY. WILL THEREFORE BACK-OFF
TEMPS A COUPLE DEGREES NORTH OF HIGHWAY 400. DO NOT HAVE ENOUGH
CONFIDENCE TO ADD OR REMOVE COUNTIES FROM THE CURRENT HEADLINE...SO
WILL LEAVE ALONE FOR NOW.
THE COLD FRONT WILL START ITS JOURNEY ACROSS THE CENTRAL PLAINS
TONIGHT. BUY MIDNIGHT IT IS EXPECTED TO STRETCH FROM EASTERN
NEBRASKA INTO EXTREME NORTHWEST KS...WITH THIS FEATURE ENTERING THE
NW FRINGES OF THE FORECAST AREA TOWARD SUNRISE. SCT CONVECTION
SHOULD DEVELOP SOUTH OF THE FRONT OVER CENTRAL AND EASTERN KS AS
MOISTURE TRANSPORT IN THE 850-700MB LEVEL INCREASES.
SAT-SUN:
BY SUNRISE SAT THE COLD FRONT IS EXPECTED TO STRETCH FROM NORTHEAST
KS INTO WEST-CENTRAL KS. WITH LACK OF STRONG/DEEP CONVERGENCE ALONG
THE FRONT...WOULD NOT BE SURPRISED TO SEE THE MORE WIDESPREAD PRECIP
BEHIND THE FRONT WHERE THE BETTER UPPER DYNAMICS WILL BE SITUATED.
WHILE CONFIDENCE IS HIGH THAT THERE WILL BE SOME SCATTERED ACTIVITY
NEAR THE FRONT AS IT PUSHES SOUTH ON SAT...HAVE LOW CONFIDENCE
ON HOW WIDESPREAD IT WILL BE. WITH SURFACE WINDS VEERING OUT AHEAD
OF THE FRONT...FEEL TEMPS COULD REALLY SOAR ACROSS SOUTH CENTRAL AND
ESPECIALLY SOUTHEAST KS. WOULD NOT BE SURPRISED TO SEE A FEW
LOCATIONS PUSH 110-111 ALONG THE KS-OK BORDER. WILL LET THE DAY
SHIFT MAKE THE CALL...BUT WOULD NOT BE SURPRISED IF THE CURRENT HEAT
HEADLINE WOULD NEED TO BE EXTENDED ANOTHER DAY.
BY SUNSET ON SAT THE FRONT SHOULD STRETCH ALONG THE KS-OK BORDER
WITH SOME SHOWERS AND STORMS ALONG AND JUST BEHIND THE FRONT.
CONFIDENCE IS HIGH THAT BY SUN MORNING THE PRECIP WILL BE SOUTH OF
THE FORECAST AREA.
MON-THU:
THROUGH THESE EXTENDED PERIODS THE UPPER RIDGE IS EXPECTED TO SHIFT
SLIGHTLY WEST WHICH WILL ALLOW THE FORECAST AREA TO REMAIN IN WEAK
DIFFLUENCE ALOFT. IN ADDITION BOTH THE ECMWF AND GFS ARE TRACKING
SOME SHORTWAVE ENERGY OUT OF THE NORTHERN ROCKIES AND ACROSS THE
MISSOURI VALLEY ON TUE NIGHT THROUGH WED. WILL KEEP SOME SMALL
PRECIP CHANCES FOR TUE NIGHT INTO WED WITH THE THINKING THAT THE
BEST CHANCES WOULD BE CLOSER TO THE UPPER DYNAMICS OVER NORTHEAST KS.
AS FAR AS TEMPS GO THROUGH THESE PERIODS...THEY WILL NOT BE AS
EXTREME AS SOUTHERN KS HAS SEEN OVER THE LAST SEVERAL DAYS...BUT
WILL STILL BE ABOVE NORMAL.
LAWSON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
BOUNDARY HAS STARTED ITS SLOW MIGRATION NORTHWARD EVIDENCED BY
INCREASED THETA-E CONVERGENCE AND WINDS VEERING TO THE SOUTHEAST IN
NORTHERN OKLAHOMA. FURTHER PROOF OF THIS IS THE SHOWERS WITH
ISOLATED THUNDER FORMING OVER SOUTHEAST KANSAS AND BUILDING
TOWARDS SOUTH CENTRAL KANSAS. LATEST HRRR GUIDANCE HAS THIS
CONVECTION LINGERING FROM HUT TO ICT AND CNU THROUGH ABOUT 12-13Z.
THE FOCUS SHIFTS TO FRIDAY AFTERNOON WHERE A VORT LOBE IS PROGGED
TO MOVE OFF THE HIGH PLAINS. THIS MAY SPARK OFF SOME SHOWERS AND
STORMS NEAR RSL AND SLN TOWARDS THE END OF THE TAF PERIOD. SINCE
CONFIDENCE ON DEVELOPMENT AND TIMING ISN`T TOO GREAT...HAVE
DECIDED TO LEAVE MENTION OF SHRA AND VCTS OUT FOR THOSE AREAS FOR
THE MOMENT.
ARL
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 102 79 100 69 / 30 20 30 40
HUTCHINSON 100 76 96 66 / 40 20 30 30
NEWTON 101 77 97 66 / 30 20 30 30
ELDORADO 102 78 99 68 / 40 20 30 40
WINFIELD-KWLD 106 80 106 71 / 40 20 30 40
RUSSELL 99 73 89 63 / 40 40 30 10
GREAT BEND 99 74 91 65 / 50 30 30 10
SALINA 100 75 91 64 / 50 30 30 20
MCPHERSON 100 75 95 65 / 50 20 30 20
COFFEYVILLE 108 80 106 71 / 50 10 20 40
CHANUTE 102 78 103 70 / 50 10 20 40
IOLA 101 78 101 69 / 50 10 20 40
PARSONS-KPPF 104 79 105 71 / 50 10 20 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069-
082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
653 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE
COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
7PM UPDATE...UPDATED POP/WX/SKY FOR LATEST RADAR/SATELLITE TRENDS.
ACTIVITY WILL CONTINUE TO DECREASE IN COVERAGE AND OVERALL
INTENSITY AS THE SUN CONTINUES TO SET.
PREV DISCUSSION...
CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND
HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE.
TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE
APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS
PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS
AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS
INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND
GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO
AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH
WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND
DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW
BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER
AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT
MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND
DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT
INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE
IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY
FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME
WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS
WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL.
HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL
PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX
TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S
W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE
MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE
COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT
INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT
HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO
THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS
WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS
WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF
AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY
LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY.
AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH
POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD
OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY
LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT
AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE
SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY
MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE
OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO
EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE
FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL
BE LAST TO CLEAR DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT.
DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY
NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY
THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES
ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE
NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING
W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY
MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED
TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE
VFR.
SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART.
HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN
EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING
COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER
COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5
FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME
OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS
HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE
OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED
THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT
AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3
FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW.
SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES
GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING
DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY
DROPPING THEM BACK 1-2 FEET.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT/NRR
SHORT TERM...FITZSIMMONS
LONG TERM...OKULSKI
AVIATION...HEWITT
MARINE...HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
317 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE
COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
CHALLENGES WILL CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW
STRONG AND HOW EXTENSIVE WILL THE FOG BE.
TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE
APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS
PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS
AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS
INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND
GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO
AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH
WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND
DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW
BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER
AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT
MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND
DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT
INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE
IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY
FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME
WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS
WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL.
HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL
PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX
TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S
W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE
MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE
COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT
INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT
HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO
THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS
WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS
WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF
AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY
LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY.
AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH
POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD
OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY
LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT
AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE
SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY
MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE
OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO
EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE
FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL
BE LAST TO CLEAR DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT.
DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY
NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY
THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES
ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE
NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING
W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY
MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED
TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE
VFR.
SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART.
HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN
EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING
COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER
COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5
FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME
OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS
HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE
OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED
THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT
AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3
FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW.
SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES
GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING
DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY
DROPPING THEM BACK 1-2 FEET.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...FITZSIMMONS
LONG TERM...OKULSKI
AVIATION...HEWITT
MARINE...HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
314 PM MDT FRI AUG 3 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
A LARGE MIDLEVEL LOW IS CURRENTLY SPINNING OVER NORTHEAST MONTANA.
THIS SYSTEM PULLED A COLD FRONT THROUGH YESTERDAY AND BROUGHT
WIDESPREAD SHOWERS AND CLOUD COVER TO THE REGION. WITH CLOUD COVER
AND RAIN ACTIVITY...HIGH TEMPERATURES HAVE NOT BEEN REACHING
FORECAST VALUES...EXCEPT IN THOSE AREAS WHICH SAW BREAKS IN THE
OVERCAST. SOME THUNDERSHOWER ACTIVITY HAS ALSO BEEN NOTED OVER
PHILLIPS COUNTY WHICH SAW SOME BREAKS IN CLOUDS AND SURFACE WARMING.
RADAR TRENDS AND RAP GUIDANCE CONTINUES SHOWER ACTIVITY WITH SOME
ISOLATED THUNDER THROUGH MIDNIGHT WITH SHOWERS ENDING GRADUALLY
FROM WEST TO EAST AS THE SYSTEM PROGRESSES EASTWARD.
WINDS HAVE BEEN BARELY STRONG ENOUGH TO JUSTIFY CONTINUING THE
LAKE WIND ADVISORY...HOWEVER...THEY HAVE BEEN CONSISTENTLY OVER
20MPH AT A NUMBER OF STATIONS AROUND THE LAKE. WINDS WILL DECLINE
BY OR SHORTLY AFTER NIGHTFALL AS SURFACE MIXING DECLINES AND
SURFACE PRESSURE RELAXES WITH THE PASSAGE OF THE WEATHER SYSTEM.
IN THE WAKE OF THIS SYSTEM...THE NEXT RIDGE MOVES IN FAIRLY
QUICKLY AND WILL BEGIN TO WARM THE REGION BY SUNDAY. MARTIN
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
A FEW CHANGES IN THE EXTENDED FORECAST DROPPED POPS ACROSS THE
WESTERN ZONES TUESDAY NIGHT. DECIDED TO STAND PAT WITH THE POPS THAT
WERE IN THE FORECAST FOR WEDNESDAY THROUGH FRIDAY EVEN THOUGH
MODELS ARE HINTING AT A RATHER LARGE RIDGE ACROSS CENTRAL AND
EASTERN MONTANA STARTING ON TUESDAY THROUGH THURSDAY WITH A
SHORTWAVE MOVING ACROSS ALBERTA AND SOUTHERN SASKATCHEWAN THURSDAY
NIGHT THROUGH FRIDAY. MODELS ALL SHOW THIS SHORTWAVE BUT DIFFER ON
WHETHER IT WILL PRODUCE ANY RAINFALL.
THE PRIMARY DIFFERENCE IS THAT THE MODELS ARE STRENGTHENING THE
MID WEEK UPPER RIDGE SO THAT IS WHY I DECIDE TO LOWER POPS TUESDAY
NIGHT THROUGH THURSDAY. THE 12Z MODEL RUNS ARE IN BETTER AGREEMENT
WITH THIS FEATURE THEN THEY WERE WITH THE 00Z MODELS RUNS. RSMITH
PREVIOUS DISCUSSION...THE EXTENDED FORECAST SHOWS LITTLE CHANGE AGAIN
TONIGHT FROM THE LAST FEW MODEL RUNS. THE BEGINNING OF THE PERIOD
SUNDAY NIGHT/MONDAY MORNING HAS RIDGING BUILDING INTO NORTHEAST
MONTANA. THIS WILL HOLD OVER THE REGION THROUGH TUESDAY. THEN THE
RIDGE MOVES A TOUCH SOUTH ALLOWING SOME RIPPLES IN THE UPPER FLOW
TO COME INTO PLAY. STILL NO MAJOR EVENT TO POINT TOWARDS A BETTER
CHANCE OF CONVECTION OVER ANOTHER SHORTWAVE. THEREFORE KEPT THE
POPS LOW MID WEEK THROUGH THE END OF THE EXTENDED.
TEMPERATURES WILL CONTINUE WITH AN ABOVE NORMAL TREND FOR THE
REGION THROUGH THE ENTIRE PERIOD. PROTON
&&
.AVIATION...
PRIMARILY VFR CEILINGS BUT COULD HAVE TEMPORARY MVFR CEILING
ACROSS THE TERMINALS DURING THIS AFTERNOON AND EVENING WITH CEILING
DROPPING BELOW 2000 FT AGL. EXPECT SCATTERED RAIN SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS TO CONTINUE ACROSS THE TERMINALS
THROUGH TONIGHT. NORTHWEST WINDS WILL DROP THIS EVENING FROM 15
TO 25 KNOTS THIS AFTERNOON TO BELOW 10 KNOTS THIS EVENING. RSMITH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR FOR FORT PECK
LAKEFORT PECK LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
409 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
4 PM UPDATE...MAINLY SKC ACRS THWEBGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWNBURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
145 PM UPDATE...
GENERALLY VFR THROUGH THE END OF THE TAF PERIOD...WITH A LOW
CHANCE AT MVFR VSBYS IN CONVECTION EARLY THIS EVENING...AND AGAIN
NEAR DAYBREAK DUE TO HAZE.
A COLD FRONT NOW JUST OVER WESTERN NY IS IN THE PROCESS OF FALLING
APART AS IT ENTERS OUR TERMINALS. WITH A RICH ENVIRONMENT AHEAD OF
THIS FRONT CONVECTION CAN`T BE RULED OUT. HOWEVER WITHOUT STRONG
UPPER LEVEL SUPPORT...ANYTHING THAT FORMS IS EXPECTED TO BE FAIRLY
ISOLATED. EVEN THOUGH WE ARE CLOSE TO THE TIME OF INITIATION (19Z
- 0Z)...COVERAGE STILL EXPECTED TO BE TOO ISOLATED TO INCLUDE IN
THE TAFS. MID AND HIGH CLOUDS EXPECTED FROM LATE THIS AFTERNOON
THROUGH TONIGHT.
NEAR DAYBREAK SATURDAY MOST OF THE MODEL GUIDANCE INDICATES MVFR
VSBYS IN HAZE AT ALL SITES. AGREE WITH THE PREVIOUS FORECASTER
THAT THE TEMP/DEW POINT SPREAD APPEARS TO BE TOO GREAT FOR A HAZY
NIGHT. IF WE WERE TO SEE HAZE KELM STILL STANDS THE BEST SHOT AND
LEFT A TEMPO GROUP IN TO COVER THAT.
WINDS SOUTH TO SOUTHWEST 5 TO 10 KTS THIS AFTERNOON...BECOMING L/V
OR LIGHT SOUTH TONIGHT. THE GRADIENT IS A BIT STRONGER SATURDAY
WHICH WILL PRODUCE SOUTH TO SOUTHWEST WINDS NEAR 10 KTS...WITH
GUSTS TOWARD 20 POSSIBLE ESPECIALLY BY AFTERNOON.
OUTLOOK...
SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD-
SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO
MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
246 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWNBURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
145 PM UPDATE...
GENERALLY VFR THROUGH THE END OF THE TAF PERIOD...WITH A LOW
CHANCE AT MVFR VSBYS IN CONVECTION EARLY THIS EVENING...AND AGAIN
NEAR DAYBREAK DUE TO HAZE.
A COLD FRONT NOW JUST OVER WESTERN NY IS IN THE PROCESS OF FALLING
APART AS IT ENTERS OUR TERMINALS. WITH A RICH ENVIRONMENT AHEAD OF
THIS FRONT CONVECTION CAN`T BE RULED OUT. HOWEVER WITHOUT STRONG
UPPER LEVEL SUPPORT...ANYTHING THAT FORMS IS EXPECTED TO BE FAIRLY
ISOLATED. EVEN THOUGH WE ARE CLOSE TO THE TIME OF INITIATION (19Z
- 0Z)...COVERAGE STILL EXPECTED TO BE TOO ISOLATED TO INCLUDE IN
THE TAFS. MID AND HIGH CLOUDS EXPECTED FROM LATE THIS AFTERNOON
THROUGH TONIGHT.
NEAR DAYBREAK SATURDAY MOST OF THE MODEL GUIDANCE INDICATES MVFR
VSBYS IN HAZE AT ALL SITES. AGREE WITH THE PREVIOUS FORECASTER
THAT THE TEMP/DEW POINT SPREAD APPEARS TO BE TOO GREAT FOR A HAZY
NIGHT. IF WE WERE TO SEE HAZE KELM STILL STANDS THE BEST SHOT AND
LEFT A TEMPO GROUP IN TO COVER THAT.
WINDS SOUTH TO SOUTHWEST 5 TO 10 KTS THIS AFTERNOON...BECOMING L/V
OR LIGHT SOUTH TONIGHT. THE GRADIENT IS A BIT STRONGER SATURDAY
WHICH WILL PRODUCE SOUTH TO SOUTHWEST WINDS NEAR 10 KTS...WITH
GUSTS TOWARD 20 POSSIBLE ESPECIALLY BY AFTERNOON.
OUTLOOK...
SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD-
SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO
MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
221 PM CDT FRI AUG 3 2012
.SHORT TERM (TONIGHT-MONDAY)...MAIN CONCERN WILL BE SEVERE
POTENTIAL. 12Z MODELS IN DECENT AGREEMENT AND WILL USE A BLEND FOR
DETAILS. SITUATION APPEARS TO BE UNFOLDING AS EXPECTED. SURFACE
BOUNDARY/COLD FRONT ACROSS CENTRAL NORTH DAKOTA WILL CONTINUE TO
PROPAGATE EASTWARD INTO THE EVENING HOURS. AS FORCING (SEEN BY
SHOWERS AND THUNDERSTORMS BEHIND THIS FEATURE) MOVES INTO THE AREA
OF HIGHER INSTABILITY (WEAKER CIN) EXPECT MORE SURFACE BASED AND
THUS STRONGER STORMS...LIKELY BY 20Z-21Z. EXPECTING A STRONG LINE
OF STORMS TO MOVE THROUGH THE REGION FROM WEST TO EAST...MUCH LIKE
THE HRRR HAS BEEN SUGGESTING. THE MAIN QUESTION AT THIS POINT IS
WHETHER OR NOT VERY STRONG DEEP LAYER (50+ KNOTS) ENTERING THE
WESTERN FA AFTER 00Z WILL INTERACT WITH THE LINE OF STORMS. THE
STRONGEST DEEP LAYER SHEAR MAY LAG THE STORMS...BUT INCREASING
SHEAR SHOULD HELP AID ORGANIZED ACTIVITY. SEE SWODY1/SWOMCD
1691/WATCH 553 FOR MORE DETAILS. MADE SOME MINOR CHANGES TO
POP/WX GRIDS BASED ON EXPECTED TIMING.
SATURDAY...UPPER LOW WILL SLOWLY PROPAGATE THROUGH THE REGION.
COLD AIR ADVECTION AND WINDY CONDITIONS EXPECTED BY THE AFTERNOON
HOURS...ALONG WITH SHOWERS AND POSSIBLY THUNDER.
SUNDAY-MONDAY...NORTHWEST FLOW ALOFT WITH WARMING AIRMASS WILL BE
THE GENERAL RULE. A WEAK FROPA IS EXPECTED ON MONDAY...BUT DRY
AIRMASS WILL REMAIN IN PLACE AND NO PRECIP EXPECTED.
.LONG TERM (MONDAY NIGHT-FRIDAY)...MEDIUM RANGE MODELS SHARE SAME
BASIC LARGE-SCALE SYNOPTIC PATTERN NEXT WEEK...BUT DIFFER QUITE A
BIT IN DETAIL. WITH RIDGE CENTERED OVER THE FOUR CORNERS AND A
HUDSON BAY TROUGH...NORTHWEST FLOW ALOFT WILL PREVAIL ACROSS THE
NORTHERN PLAINS. BOTH GFS/ECMWF PAINT PERIODS OF LIGHT QPF TUESDAY
NIGHT THROUGH THE END OF THE WEEK WITH WEAK EMBEDDED SHORT-
WAVES...SO WILL MAINTAIN ALL BLEND 20 TO 30 POPS. NO REAL CHANGE
IN AIR MASS...SO TEMPERATURES WILL RANGE FROM THE 80S DURING THE
DAY TO THE 60S AT NIGHT.
&&
.AVIATION...SHOWERS AND THUNDERSTORMS ACROSS CENTRAL ND WILL MOVE
EAST- NORTHEASTWARD LATE THIS AFTERNOON AND EVENING...IMPACTING
ALL TAF SITES. SOME STORMS MAY BE SEVERE WITH DAMAGING WIND AND
LARGE HAIL. CEILINGS AND VISIBILITY MAY ALSO DROP INTO THE
MVFR/IFR RANGE WITH STRONGER STORMS. GUSTY SOUTH-SOUTHEAST WIND
WILL SHIFT TO THE WEST-NORTHWEST OVERNIGHT AFTER COLD FRONTAL
PASSAGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG/ROGERS
AREA FORECAST DISCUSSION
NWS NORMAN OK
322 PM CDT FRI AUG 3 2012
.DISCUSSION...
ONGOING CRITICAL FIRE WEATHER CONDITIONS AND RECORD BREAKING
HEAT ARE THE MAIN CONCERNS.
HEAT ADVISORY IS IN GREAT SHAPE AND WILL NOT ALTER.
THROUGH TONIGHT...WINDS WILL STAY UP IN THE 10 TO 15 MPH OVER
MUCH OF THE AREA...THOUGH THE STRONGEST GUSTS SHOULD DIMINISH
BETWEEN 6 AND 9 PM CDT. KEPT 20 PERCENT FOR SHOWERS AND STORMS
OVER NORTHERN OKLAHOMA...MAINLY NORTH OF AN ARNETT TO STILLWATER
LINE WHERE CAP IS WEAKEST. LATEST HRRR INDICATED NEW DEVELOPMENT
THIS EVENING IN FAR NORTHWEST OKLAHOMA. GUSTY WINDS IS THE MAIN
HAZARD WITH ANY STORM DUE TO HIGH CLOUD BASES.
SATURDAY WILL BE ANOTHER VERY HOT DAY...THOUGH MAY BE SLIGHTLY
COOLER DUE TO SLIGHTLY COOLER LOW LEVEL TEMPERATURES. A WEAK
FRONT WILL PUSH INTO NORTHERN OKLAHOMA DURING THE AFTERNOON
AND EVENING HOURS WHICH MAY ALLOW FOR ISOLATED STORM
DEVELOPMENT...SO KEPT 20 PERCENT CHANCES IN THESE AREAS.
SUNDAY THROUGH NEXT FRIDAY...DRY AND HOT CONDITIONS WILL
LIKELY CONTINUE. TEMPERATURES WILL BE COOLER DURING THIS
TIME FRAME...ESPECIALLY ON SUNDAY AS SOME LOCATIONS
MAY NOT REACH 100 DEGREES. CANNOT COMPLETELY RULE OUT
A FEW STORMS SUNDAY AND MONDAY...BUT KEPT A DRY FORECAST
DUE TO LOW CONFIDENCE OF OCCURRENCE.
MBS
&&
.FIRE WEATHER...
CURRENT RED FLAG WARNING IS IN GOOD SHAPE AND CONTINUES UNTIL 10
PM CDT. GUSTY SOUTH TO SOUTHWEST WINDS WILL DIMINISH SLIGHTLY
BETWEEN 6 AND 9 PM CDT AND SHIFT MAINLY TO THE SOUTH. LOCATIONS
NORTH OF A WEAK OUTFLOW BOUNDARY FROM PUTNAM TO CHANDLER HAVE A
LOWER CHANCE FOR FIRE IGNITIONS.
UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR
THE SAME AREAS ON SATURDAY DUE TO VERY SIMILAR FORECAST CONDITIONS.
WINDS MAY BE A NUDGE STRONGER ON SATURDAY COMPARED TO TODAY.
LIGHTER WINDS AND COOLER TEMPERATURES WILL ALLOW FOR
SLIGHTLY LOWER WILDFIRE POTENTIAL SUNDAY INTO NEXT WEEK.
&&
.CLIMATE...
OKLAHOMA CITY HAS ALREADY REACHED 112 DEGREES TODAY
SETTING A NEW DAILY RECORD. THE ALL TIME RECORD OF 113
DEGREES MAY BE TIED OR EXCEEDED IN THE NEXT FEW HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 112 83 109 74 / 20 0 10 10
HOBART OK 111 79 109 75 / 10 0 0 10
WICHITA FALLS TX 111 80 110 77 / 0 0 0 0
GAGE OK 103 74 100 66 / 30 20 20 30
PONCA CITY OK 107 78 110 69 / 40 10 20 30
DURANT OK 106 78 107 77 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR OKZ008-012-013-
016>047-050-051.
RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR OKZ008-012-
013-016>047-050-051.
HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR OKZ004>048-050>052.
TX...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR TXZ083>090.
RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR TXZ083>090.
HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR TXZ083>090.
&&
$$
84/17
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
533 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
2130 UTC UPDATE...POPS WERE LOWERED ALONG THE TN BORDER IN THE
CENTRAL AND SOUTHERN NC MOUNTAINS PER RADAR TRENDS...AND RAISED IN
THE NORTHERN NC MOUNTAINS. QPF WAS LOWERED IN THE FOOTHILLS AND
PIEDMONT. SKY COVER WAS UPDATED FORM THE LATEST VISIBLE IMAGERY.
PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE
SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN
THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING
SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN.
THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS
THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND
LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS
EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN
WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP
CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED
AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE
AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING.
THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO
DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE.
OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST
ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD.
DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE
GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING.
PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT
EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT
WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY
HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS
POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS
MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN
UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE
IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE
AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY
JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE
REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN
SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND...
THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH
A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH
THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE
GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS
FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE
MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE
WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE
TO CLIMO.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SHOWERS ARE BEGINNING TO DEVELOP OVER THE FOOTHILLS ABOUT
80 MI WEST OF THE AIRFIELD. WHILE CONVECTION IS EXPECTED TO BUILD
OVER THE FOOTHILLS THE REST OF THE AFTN...IT WILL TAKE A WHILE FOR
STORMS TO DEVELOP OUT ACROSS THE PIEDMONT. HOWEVER...MANY NUMERICAL
MODELS ARE BULLISH ON DEVELOPING CONVECTION...AND I THINK THAT BY 22
UTC TSTMS ARE LIKELY TO DEVELOP IN PLACE OVER THE REGION. THE TEMPO
GROUP FOR CONVECTION FROM 22-02 UTC STILL LOOKS GOOD FOR THIS
REASON. THE MODEL GUIDANCE ALSO IS STRONGLY SUGGESTING THAT STRATUS
WILL DEVELOP OVERNIGHT. WITH DEWPOINTS GETTING UP INTO THE LOW 70S
AND EXPECTED WIDESPREAD UPSTREAM PRECIPITATION THIS LOOKS REASONABLE
AND AN 800 FOOT CIG HAS BEEN INTRODUCED INTO THE TAF VERY LATE
TONIGHT THROUGH MID MORNING ON SATURDAY.
AND ELSEWHERE...SHRA/TSTMS ARE BEGINNING TO DEVELOP IN THE VCNTY OF
THE KAVL AIRFIELD. VCTS HAS BEEN ADDED FOR THE NEXT FEW HOURS WITH
PREVAILING THUNDER FROM LATE AFTN INTO THE EARLY EVENING AS IT LOOKS
TO BE A STORMY EVENING IN THE MTNS AHEAD OF AN APPROACHING UPPER
LOW. ONCE CONVECTION ENDS LATER TONIGHT LOW CLOUDS AND VALLEY FOG
SHOULD DEVELOP. THE TIMING WILL DEPEND UPON HOW MUCH RAIN FALLS AT
THE AIRFIELD AND HOW QUICKLY MID AND HIGH CLOUDS THIN. THE SAME
APPLIES TO THE REST OF THE REGION...THOUGH IT WILL TAKE TSTMS A FEW
HOURS YET TO BEGIN TO DEVELOP OUTSIDE THE MTNS. TEMPO OR PREVAILING
GROUPS WILL PROBABLY BE NEEDED AT MOST AIRFIELDS...BUT CONFIDENCE
ISN/T HIGH ENOUGH TO DO THAT YET OUTSIDE THE MTNS. WITH LOW 70S
DEWPOINTS...15 KTS OF SLY LLVL FLOW AND MORE RAIN THIS
EVENING...STRATUS IS A GOOD BET TONIGHT. BASED ON THE AMOUNT OF
MIXING AND 800 FOOT DECK SEEMS REASONABLE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...JAT/MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
349 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
1930 UTC UPDATE...POPS WERE INCREASED ALONG THE TN BORDER IN THE
CENTRAL AND SOUTHERN NC MOUNTAINS PER RADAR TRENDS. SKY COVER WAS
UPDATED FORM THE LATEST VISIBLE IMAGERY.
PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE
SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN
THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING
SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN.
THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS
THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND
LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS
EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN
WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP
CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED
AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE
AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING.
THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO
DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE.
OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST
ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD.
DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE
GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING.
PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT
EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT
WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY
HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS
POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS
MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN
UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE
IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE
AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY
JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE
REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN
SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND...
THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH
A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH
THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE
GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS
FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE
MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE
WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE
TO CLIMO.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SHOWERS ARE BEGINNING TO DEVELOP OVER THE FOOTHILLS ABOUT
80 MI WEST OF THE AIRFIELD. WHILE CONVECTION IS EXPECTED TO BUILD
OVER THE FOOTHILLS THE REST OF THE AFTN...IT WILL TAKE A WHILE FOR
STORMS TO DEVELOP OUT ACROSS THE PIEDMONT. HOWEVER...MANY NUMERICAL
MODELS ARE BULLISH ON DEVELOPING CONVECTION...AND I THINK THAT BY 22
UTC TSTMS ARE LIKELY TO DEVELOP IN PLACE OVER THE REGION. THE TEMPO
GROUP FOR CONVECTION FROM 22-02 UTC STILL LOOKS GOOD FOR THIS
REASON. THE MODEL GUIDANCE ALSO IS STRONGLY SUGGESTING THAT STRATUS
WILL DEVELOP OVERNIGHT. WITH DEWPOINTS GETTING UP INTO THE LOW 70S
AND EXPECTED WIDESPREAD UPSTREAM PRECIPITATION THIS LOOKS REASONABLE
AND AN 800 FOOT CIG HAS BEEN INTRODUCED INTO THE TAF VERY LATE
TONIGHT THROUGH MID MORNING ON SATURDAY.
AND ELSEWHERE...SHRA/TSTMS ARE BEGINNING TO DEVELOP IN THE VCNTY OF
THE KAVL AIRFIELD. VCTS HAS BEEN ADDED FOR THE NEXT FEW HOURS WITH
PREVAILING THUNDER FROM LATE AFTN INTO THE EARLY EVENING AS IT LOOKS
TO BE A STORMY EVENING IN THE MTNS AHEAD OF AN APPROACHING UPPER
LOW. ONCE CONVECTION ENDS LATER TONIGHT LOW CLOUDS AND VALLEY FOG
SHOULD DEVELOP. THE TIMING WILL DEPEND UPON HOW MUCH RAIN FALLS AT
THE AIRFIELD AND HOW QUICKLY MID AND HIGH CLOUDS THIN. THE SAME
APPLIES TO THE REST OF THE REGION...THOUGH IT WILL TAKE TSTMS A FEW
HOURS YET TO BEGIN TO DEVELOP OUTSIDE THE MTNS. TEMPO OR PREVAILING
GROUPS WILL PROBABLY BE NEEDED AT MOST AIRFIELDS...BUT CONFIDENCE
ISN/T HIGH ENOUGH TO DO THAT YET OUTSIDE THE MTNS. WITH LOW 70S
DEWPOINTS...15 KTS OF SLY LLVL FLOW AND MORE RAIN THIS
EVENING...STRATUS IS A GOOD BET TONIGHT. BASED ON THE AMOUNT OF
MIXING AND 800 FOOT DECK SEEMS REASONABLE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...JAT/MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
331 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
1930 UTC UPDATE...POPS WERE INCREASED ALONG THE TN BORDER IN THE
CENTRAL AND SOUTHERN NC MOUNTAINS PER RADAR TRENDS. SKY COVER WAS
UPDATED FORM THE LATEST VISIBLE IMAGERY.
PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE
SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN
THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING
SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN.
THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS
THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND
LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS
EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN
WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP
CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED
AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE
AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING.
THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO
DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE.
OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST
ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD.
DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE
GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING.
PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT
EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT
WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY
HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS
POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS
MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUDNERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE APPROACH OF A WEAK COLD FRONT
WILL CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH
TUE...WITH AN UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME
PERIOD. THERE IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW
FAR SOUTH THE AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE
FRONTAL BOUNDARY JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT
DRYER INTO THE REGION FOR WED INTO THU. THIS WOULD PRODUCE A
DECREASE IN SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE
OTHER HAND... THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH
THE PERIOD WITH A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM
ACTIVITY THROUGH THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL
POSITION. WE GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN
CLIMO POPS FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY
ACROSS THE MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE
END OF THE WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH
ESSENTIALLY IS CLOSE TO CLIMO.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SHOWERS ARE BEGINNING TO DEVELOP OVER THE FOOTHILLS ABOUT
80 MI WEST OF THE AIRFIELD. WHILE CONVECTION IS EXPECTED TO BUILD
OVER THE FOOTHILLS THE REST OF THE AFTN...IT WILL TAKE A WHILE FOR
STORMS TO DEVELOP OUT ACROSS THE PIEDMONT. HOWEVER...MANY NUMERICAL
MODELS ARE BULLISH ON DEVELOPING CONVECTION...AND I THINK THAT BY 22
UTC TSTMS ARE LIKELY TO DEVELOP IN PLACE OVER THE REGION. THE TEMPO
GROUP FOR CONVECTION FROM 22-02 UTC STILL LOOKS GOOD FOR THIS
REASON. THE MODEL GUIDANCE ALSO IS STRONGLY SUGGESTING THAT STRATUS
WILL DEVELOP OVERNIGHT. WITH DEWPOINTS GETTING UP INTO THE LOW 70S
AND EXPECTED WIDESPREAD UPSTREAM PRECIPITATION THIS LOOKS REASONABLE
AND AN 800 FOOT CIG HAS BEEN INTRODUCED INTO THE TAF VERY LATE
TONIGHT THROUGH MID MORNING ON SATURDAY.
AND ELSEWHERE...SHRA/TSTMS ARE BEGINNING TO DEVELOP IN THE VCNTY OF
THE KAVL AIRFIELD. VCTS HAS BEEN ADDED FOR THE NEXT FEW HOURS WITH
PREVAILING THUNDER FROM LATE AFTN INTO THE EARLY EVENING AS IT LOOKS
TO BE A STORMY EVENING IN THE MTNS AHEAD OF AN APPROACHING UPPER
LOW. ONCE CONVECTION ENDS LATER TONIGHT LOW CLOUDS AND VALLEY FOG
SHOULD DEVELOP. THE TIMING WILL DEPEND UPON HOW MUCH RAIN FALLS AT
THE AIRFIELD AND HOW QUICKLY MID AND HIGH CLOUDS THIN. THE SAME
APPLIES TO THE REST OF THE REGION...THOUGH IT WILL TAKE TSTMS A FEW
HOURS YET TO BEGIN TO DEVELOP OUTSIDE THE MTNS. TEMPO OR PREVAILING
GROUPS WILL PROBABLY BE NEEDED AT MOST AIRFIELDS...BUT CONFIDENCE
ISN/T HIGH ENOUGH TO DO THAT YET OUTSIDE THE MTNS. WITH LOW 70S
DEWPOINTS...15 KTS OF SLY LLVL FLOW AND MORE RAIN THIS
EVENING...STRATUS IS A GOOD BET TONIGHT. BASED ON THE AMOUNT OF
MIXING AND 800 FOOT DECK SEEMS REASONABLE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...JAT/MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
238 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
CONVECTION HAS BEGUN TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC
MTNS. LAYER RH VALUES ARE THE HIGHEST IN THIS PART OF THE FORECAST
AREA...AND IT/S CLOSET TO THE APPROACHING SHORTWAVE TROUGH WHICH
CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN. THE FEATURE ITSELF IS
QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS THE REGION IS WELL
UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND LLVL MASS
CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS EVENING.
THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN WHAT I
SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP CONVECTION
OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED AS EARLIER.
THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE AREA OF
CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING. THE 12
UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO DEVELOPS
INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE. OVERALL...THE IDEA
OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST ACROSS THE FA THE
REST OF THE AFN AND EVENING STILL LOOKS GOOD. DCAPE VALUES ARE WELL
OVER 1000 J/KG ACROSS THE UPSTATE AND NE GA...AND PULSE SEVERE
STORMS ARE A GOOD BET AGAIN THIS EVENING. PULSE SEVERE WON/T BE
LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT EVEN THOUGH CURRENT
DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT WE/LL SEE A FEW
SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY HEAVY RAIN IS ALSO
POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS POSSIBLE. LATER
TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUDNERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE APPROACH OF A WEAK COLD FRONT
WILL CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH
TUE...WITH AN UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME
PERIOD. THERE IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW
FAR SOUTH THE AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE
FRONTAL BOUNDARY JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT
DRYER INTO THE REGION FOR WED INTO THU. THIS WOULD PRODUCE A
DECREASE IN SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE
OTHER HAND... THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH
THE PERIOD WITH A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM
ACTIVITY THROUGH THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL
POSITION. WE GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN
CLIMO POPS FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY
ACROSS THE MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE
END OF THE WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH
ESSENTIALLY IS CLOSE TO CLIMO.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SHOWERS ARE BEGINNING TO DEVELOP OVER THE FOOTHILLS ABOUT
80 MI WEST OF THE AIRFIELD. WHILE CONVECTION IS EXPECTED TO BUILD
OVER THE FOOTHILLS THE REST OF THE AFTN...IT WILL TAKE A WHILE FOR
STORMS TO DEVELOP OUT ACROSS THE PIEDMONT. HOWEVER...MANY NUMERICAL
MODELS ARE BULLISH ON DEVELOPING CONVECTION...AND I THINK THAT BY 22
UTC TSTMS ARE LIKELY TO DEVELOP IN PLACE OVER THE REGION. THE TEMPO
GROUP FOR CONVECTION FROM 22-02 UTC STILL LOOKS GOOD FOR THIS
REASON. THE MODEL GUIDANCE ALSO IS STRONGLY SUGGESTING THAT STRATUS
WILL DEVELOP OVERNIGHT. WITH DEWPOINTS GETTING UP INTO THE LOW 70S
AND EXPECTED WIDESPREAD UPSTREAM PRECIPITATION THIS LOOKS REASONABLE
AND AN 800 FOOT CIG HAS BEEN INTRODUCED INTO THE TAF VERY LATE
TONIGHT THROUGH MID MORNING ON SATURDAY.
AND ELSEWHERE...SHRA/TSTMS ARE BEGINNING TO DEVELOP IN THE VCNTY OF
THE KAVL AIRFIELD. VCTS HAS BEEN ADDED FOR THE NEXT FEW HOURS WITH
PREVAILING THUNDER FROM LATE AFTN INTO THE EARLY EVENING AS IT LOOKS
TO BE A STORMY EVENING IN THE MTNS AHEAD OF AN APPROACHING UPPER
LOW. ONCE CONVECTION ENDS LATER TONIGHT LOW CLOUDS AND VALLEY FOG
SHOULD DEVELOP. THE TIMING WILL DEPEND UPON HOW MUCH RAIN FALLS AT
THE AIRFIELD AND HOW QUICKLY MID AND HIGH CLOUDS THIN. THE SAME
APPLIES TO THE REST OF THE REGION...THOUGH IT WILL TAKE TSTMS A FEW
HOURS YET TO BEGIN TO DEVELOP OUTSIDE THE MTNS. TEMPO OR PREVAILING
GROUPS WILL PROBABLY BE NEEDED AT MOST AIRFIELDS...BUT CONFIDENCE
ISN/T HIGH ENOUGH TO DO THAT YET OUTSIDE THE MTNS. WITH LOW 70S
DEWPOINTS...15 KTS OF SLY LLVL FLOW AND MORE RAIN THIS
EVENING...STRATUS IS A GOOD BET TONIGHT. BASED ON THE AMOUNT OF
MIXING AND 800 FOOT DECK SEEMS REASONABLE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
204 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM...THE LATEST NAM HAS A LARGE CONVECTIVE BULLSEYE OVER
THE UPSTATE THIS EVENING. NORMALLY I WOULDN/T JUMP ON SUCH A FEATURE
ON THE NAM. HOWEVER...THE LATEST RAP HAS A BULLSEYE IN DARN NEAR THE
SAME PLACE. OUR TWO WORKSTATION WRF MODELS AND THE SPC HIGH RES WRF
ALSO HAVE MORE CONCENTRATED AREAS OF CONVECTION ACROSS NE GA AND THE
UPSTATE THIS EVENING. THE SRN NC PIEDMONT ALSO GETS INTO THE ACTION
ON THE WRF-ARW. THE OLD GFS HAD A BULLSEYE FARTHER TO THE SW...OVER
NE GA. THEY SEEM TO BE KEYING ON AN AREA OF LLVL CONVERGENCE THAT
DEVELOPS THIS AFTN AS THE BNDRY LAYER FLOW IS SW OVER THE WRN
UPSTATE AND NE GA...BUT BACKS TO THE SSE OVER THE I-77 CORRIDOR
AHEAD OF THE APPROACHING MCV. CONSIDERING THAT SOMETHING QUITE
SIMILAR HAPPENED LAST NIGHT WITH WEAKER FORCING...I/M GOING TO RAISE
POPS TO LIKELY ACROSS THE I-85 CORRIDOR FOR THIS EVENING WITH THIS
UPDATE. THE STORMS WILL BE SLOW MOVING AGAIN TODAY...RESULTING IN A
THREAT OF LOCALIZED FLOODING. EAST OF THE MTNS THE MID-LEVELS STAY
FAIRLY DRY INTO THE EVENING...YIELDING AN ISOLATED DAMAGING WIND
THREAT AS WELL.
AS OF 945 AM...ADDED A SMALL STRIPE OF LOW CHANCE POPS ACROSS THE
CENTRAL UPSTATE...NORTHWARD INTO THE SRN NC FOOTHILLS AND WESTERN
PIEDMONT. SCT SHRA HAVE DEVELOPED IN THIS AREA. BASED ON THE STRONG
CAP ON THE 12 UTC GSO SOUNDING I/M SURE THESE SHRA ARE ELEVATED AND
THEY SHOULD DISSIPATE ONCE MIXING INCREASES. HOWEVER...WE HAVE HAD
REPORTS OF A COUPLE GOOD DOWNPOURS UNDER THEM SO IT/S WORTH AN
UPDATE. THE REST OF THE GRIDS LOOK PRETTY GOOD. DECAYING MCS DEBRIS
ARE WELL HANDLED...THOUGH I/VE ADDED A LITTLE CLOUD COVER ALONG THE
ESCARPMENT WHEN A BAND OF STRATUS HAS DEVELOPED.
AS OF 645 AM...NO MAJOR CHANGES WERE MADE WITH THIS UPDATE. MAINLY
SKY COVER ADJUSTMENTS TO LINE UP WITH STRATUS DEVELOPMENT AND HIGH
CLOUDS BLOWING IN FROM THE WEST.
AS OF 230 AM...THE MAIN FCST CHALLENGE INVOLVES THE APPROACH OF AN
MCV CURRENTLY OVER CENTRAL KY. THE NEAR TERM GUIDANCE...INCLUDING
HI-RES MODELS ALL AGREE THAT THIS FEATURE SHUD SUPPORT SCATTERED TO
NUMEROUS SHWRS AND TSTMS...POSSIBLY STARTING NOT LONG AFTER DAYBREAK
IN THE WEST. THERE IS A LOT OF DEBRIS CLOUDINESS WITH THE MCS...AS
CONVECTION IS STILL ONGOING ATTM. SO IT IS POSSIBLE THAT THE WRN
ZONES MAY BE QUIET (DUE TO LACK OF INSOLATION)...WHILE THE EAST HAS
MORE ACTIVITY. THE NAM IS A LITTLE SLOWER WITH THE MCV AND THE
INITIATION OF STORMS...AND LIKE USUAL...HAS WARMER MAX TEMPS AND
HIGHER SBCAPE THIS AFTN THAN THE GFS. FOR NOW...WENT WITH A MODEL
BLEND...GIVEN UNCERTAINTY ON THE DISSIPATION OF THE MCS AND THINNING
CLOUD COVER. THE INHERITED POPS LOOK PRETTY GOOD WHEN COMPARING TO
THE MODEL CONSENSUS. FCST SNDGS SHOW MOISTENING MID LVLS AND VERY
WEAK SHEAR. SO PROBABLY A CASE WHERE THERE WILL BE DECENT COVERAGE
BUT ONLY A FEW PULSE SEVERE STORMS. MAX TEMPS WERE TWEAKED DOWN A
DEG OR TWO IN SPOTS WITH LATEST BIAS-CORRECTED MOSGUIDE.
TONIGHT...AS DEEP MOISTURE SETTLES INTO THE AREA AND AFOREMENTIONED
MCV STALLS JUST TO OUR WEST...INDICATIONS ARE THAT ISOLD-SCT
CONVECTION WILL LIKELY LINGER THRU MOST OF THE NIGHT. THE STEERING
FLOW REMAINS WEAK AND PWATS APPROACH 2.00"...SO A SMALL HYDRO THREAT
WILL EXIST. MIN TEMPS WILL BE TYPICAL OF LAST FEW DAYS (60S MTNS AND
GENERALLY LWR 70S PIEDMONT).
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...SAT OVERNIGHT THROUGH SUNDAY MORNING IS
EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE FLOW AND THE
APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD TRIGGER SCATTERED
TO NUMEROUS SHOWERS/THUDNERSTORMS ACROSS THE MOUNTAINS. ONLY
ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED ELSEWHERE. THE
MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS SUNDAY NIGHT
WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS THERE. ON
MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE WESTERN
CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM TEMPERATURES ARE
EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES ABOUT A CATEGORY
ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE APPROACH OF A WEAK COLD FRONT
WILL CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH
TUE...WITH AN UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME
PERIOD. THERE IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW
FAR SOUTH THE AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE
FRONTAL BOUNDARY JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT
DRYER INTO THE REGION FOR WED INTO THU. THIS WOULD PRODUCE A
DECREASE IN SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE
OTHER HAND... THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH
THE PERIOD WITH A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM
ACTIVITY THROUGH THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL
POSITION. WE GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN
CLIMO POPS FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY
ACROSS THE MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE
END OF THE WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH
ESSENTIALLY IS CLOSE TO CLIMO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SHOWERS ARE BEGINNING TO DEVELOP OVER THE FOOTHILLS ABOUT
80 MI WEST OF THE AIRFIELD. WHILE CONVECTION IS EXPECTED TO BUILD
OVER THE FOOTHILLS THE REST OF THE AFTN...IT WILL TAKE A WHILE FOR
STORMS TO DEVELOP OUT ACROSS THE PIEDMONT. HOWEVER...MANY NUMERICAL
MODELS ARE BULLISH ON DEVELOPING CONVECTION...AND I THINK THAT BY 22
UTC TSTMS ARE LIKELY TO DEVELOP IN PLACE OVER THE REGION. THE TEMPO
GROUP FOR CONVECTION FROM 22-02 UTC STILL LOOKS GOOD FOR THIS
REASON. THE MODEL GUIDANCE ALSO IS STRONGLY SUGGESTING THAT STRATUS
WILL DEVELOP OVERNIGHT. WITH DEWPOINTS GETTING UP INTO THE LOW 70S
AND EXPECTED WIDESPREAD UPSTREAM PRECIPITATION THIS LOOKS REASONABLE
AND AN 800 FOOT CIG HAS BEEN INTRODUCED INTO THE TAF VERY LATE
TONIGHT THROUGH MID MORNING ON SATURDAY.
AND ELSEWHERE...SHRA/TSTMS ARE BEGINNING TO DEVELOP IN THE VCNTY OF
THE KAVL AIRFIELD. VCTS HAS BEEN ADDED FOR THE NEXT FEW HOURS WITH
PREVAILING THUNDER FROM LATE AFTN INTO THE EARLY EVENING AS IT LOOKS
TO BE A STORMY EVENING IN THE MTNS AHEAD OF AN APPROACHING UPPER
LOW. ONCE CONVECTION ENDS LATER TONIGHT LOW CLOUDS AND VALLEY FOG
SHOULD DEVELOP. THE TIMING WILL DEPEND UPON HOW MUCH RAIN FALLS AT
THE AIRFIELD AND HOW QUICKLY MID AND HIGH CLOUDS THIN. THE SAME
APPLIES TO THE REST OF THE REGION...THOUGH IT WILL TAKE TSTMS A FEW
HOURS YET TO BEGIN TO DEVELOP OUTSIDE THE MTNS. TEMPO OR PREVAILING
GROUPS WILL PROBABLY BE NEEDED AT MOST AIRFIELDS...BUT CONFIDENCE
ISN/T HIGH ENOUGH TO DO THAT YET OUTSIDE THE MTNS. WITH LOW 70S
DEWPOINTS...15 KTS OF SLY LLVL FLOW AND MORE RAIN THIS
EVENING...STRATUS IS A GOOD BET TONIGHT. BASED ON THE AMOUNT OF
MIXING AND 800 FOOT DECK SEEMS REASONABLE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
335 PM EDT FRI AUG 3 2012
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES WILL MOVE EAST ACROSS OUR REGION
TONIGHT INTO SATURDAY. ALOFT...A LARGE RIDGE OF HIGH PRESSURE COVERED
TEXAS...THIS RIDGE FORECAST TO EXPAND OVER THE SOUTHEAST AND THE
MIDDLE ATLANTIC THROUGH THE WEEKEND. A COLD FRONT WILL DROP SOUTH
FROM THE GREAT LAKES AND THE OHIO VALLEY EARLY NEXT WEEK...THE
RESULT OF AN AGGRESSIVE UPPER LEVEL TROUGH WHICH IS FORECAST TO
MOVE THROUGH THE GREAT LAKES AND OHIO VALLEY REGION SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 305 PM EDT FRIDAY...
COMPLICATED FORECAST WITH PLACEMENT OF CONVECTION THIS EVENING
INTO TONIGHT. THE LOW CLOUDS WHICH LIFTED NORTH ACROSS THE REGION
THIS MORNING ESPECIALLY ALONG THE EASTERN SLOPES OF BLUE RIDGE HAS
SLOWED THE DEVELOPMENT OF THE THUNDERSTORMS THIS AFTERNOON AND
HINDERED INSTABILITY. KFCX 88D SHOWED ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF AREAS OF CONVECTION
ACROSS EASTERN KENTUCKY. THIS CONVECTION IS ASSOCIATED WITH
SHORTWAVE MOVING SLOWLY ESE. OUTFLOW AND LEFTOVER BOUNDARIES FROM
THUNDERSTORMS WILL MOVE ACROSS OUR REGION THIS EVENING INTO
TONIGHT.
CONVECTION WHICH FIRES ALONG THE UPPER LEVEL DISTURBANCE
ALONG THE CAROLINA COAST... MAY SEND AXIS OF DEEPER MOISTURE
NORTHWARD INTO OUR SE CWA INITIATING LATE AFTERNOON AND EVE
SHRA/TSRA. NAM...GFS...WRFARW-RNK AND HRRR PLACE THE HIGHEST POPS
ACROSS SOUTHWEST PORTION OF CWA THIS AFTERNOON INTO TONIGHT.
OVERALL...DEEP LAYER WINDS ACROSS THE MID ATLANTIC REGION
REMAIN WEAK...MEAN WIND LESS THAN 10 KTS. ANY DEEP CONVECTION THAT
DEVELOPS WILL BE SLOW MOVING WITH POTENTIAL OF HEAVY RAINS. TAPER
OFF POPS WITH THE LOSS OF SOLAR HEATING TONIGHT BUT HOLD ON TO SOME
ACTIVITY IN THE SOUTHWEST.
LEANED LOW TEMPERATURES TONIGHT TOWARDS THE ADJMET WITH THE IDEA OF
MORE CLOUDINESS KEEPING TEMPERATURES ELEVATED. ALSO ADD THE MENTION
OF PATCHY FOG OVERNIGHT WHICH CAN BE SHAPED TO WHERE THUNDERSTORMS
OCCUR.
DEEPER MOISTURE WILL REMAIN IN PLACE ESPECIALLY OVER THE WEST
SATURDAY. WEAKENING MID LEVEL WAVE AND OLD BOUNDARIES REMAINS ALONG
THE MOUNTAINS SATURDAY AFTERNOON DURING MAX HEATING. THE COMBINATION
OF W/NW FLOW ALOFT AND DECENT INSTABILITY WEST APPEARS TO BE A GOOD
SETUP FOR MULTICELLULAR BANDS ACROSS THE MOUNTAINS...WITH SOME OF
THIS ACTIVITY ABLE TO SPILL EAST OF THE BLUE RIDGE LATE. INCREASED
POPS AND EXTENDED CHANCES OUT EAST TO THE PIEDMONT. SHAPED TIMING
AND POPS CLOSE TO NAM. PLAYED HIGH CLOSER TO COOL MOS BECAUSE OF
CLOUD COVER WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO
AROUND 90 DEGREES IN THE SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 330 PM EDT FRIDAY...
SCATTERED LINGERING SHOWERS AND STORMS LATE SATURDAY ARE LIKELY TO
QUICKLY DISSIPATE BY LATE EVENING AS LITTLE IN THE WAY OF ORGANIZED
FORCING IS EXPECTED IN GENERALLY SOUTHERLY FLOW. THE 12Z GFS
PRODUCES SOME CONVECTIVELY INDUCED SHORT WAVES OVER TN/KY AND TRIES
TO CONTINUE SOME ACTIVITY MOST OF THE NIGHT ACROSS THE WEST BUT FEEL
THIS IS PROBABLY OVERDONE TO LARGE DEGREE...WHEREAS NAM HAS NOTHING ACROSS
THE WEST BUT CONTINUES CONVECTION ACROSS THE FAR EAST WELL PAST
MIDNIGHT IN ASSOC WITH A VERY WEAK LEE TROUGH. NOT SURE HOW MUCH TO
TRUST EITHER SOLUTION...BUT WILL LEAN MORE TOWARD THE GFS NOTION OF
KEEPING CHANCES GOING A LITTLE LONGER IN THE WEST...BUT WILL DROP
POPS QUICKLY AFTER MIDNIGHT.
SUNDAY APPEARS TO HAVE BETTER CHANCES...ESPECIALLY LATER IN THE DAY
OUT AHEAD OF APPROACHING FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY.
SOME INCREASE IN SHEAR AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A
BETTER SEVERE POTENTIAL AS WELL...WITH MORE ORGANIZED CLUSTERS
COMING OUT OF OF WV AHEAD OF FRONT. MAIN THREAT DURING THE DAY WOULD
MAINLY BE IN THE WEST. EXACT TIMING IS IN QUESTION...INCLUDING
WHETHER THERE WILL BE STORMS WELL OUT AHEAD OF FRONT DEVELOPING WITH
MAX HEATING AND OVER HIGHER TERRAIN...OR DOES IT WAIT UNTIL FRONTAL
BOUNDARY ACTUALLY ARRIVES WHICH WOULD BE MORE EVENING AND EVEN
OVERNIGHT IN THE WEST. SEVERE CHANCES MUCH LESS EAST OF THE BLUE
RIDGE GIVEN TIMING OF FRONT...BUT IF ANYTHING DEVELOPS WELL OUT
AHEAD...A FEW OF THESE STORMS COULD DRIFT INTO THE PIEDMONT LATE IN
THE DAY. IN ANY CASE...EXPECT AT LEAST MORE CLOUD COVER FROM
UPSTREAM CONVECTION TO KEEP TEMPS DOWN A BIT IN THE WEST...SO WENT
CLOSER TO COOLER MET GUIDANCE IN WEST...AND WARMER MAV IN EAST.
BOUNDARY SLOWLY DRIFTS ACROSS THE FCST AREA SUNDAY NIGHT INTO
MONDAY...AND MUCH BETTER CHANCE FOR LINGERING CONVECTION OR AT LEAST
SHOWERS MOST OF THE NIGHT SUNDAY NIGHT...AND ANY REDEVELOPMENT OF
DEEPER CONVECTION MONDAY WOULD BE ACROSS THE SOUTHEAST...AND
DEPENDENT ON ANY SMALL DEGREE OF SFC HEATING...BUT SEVERE CHANCES
SHOULD BE MUCH LOWER DUE TO LACK OF GOOD HEATING MONDAY. MONDAY
MORNING LOWS SHOULD BE PRETTY MILD WITH MOSTLY CLOUDY AND EVEN
ONGOING SHOWERS...AND MAV NUMBERS LOOK GOOD THERE WITH LOW TO MID
70S FOR MINS IN PIEDMONT AND UPPER 60S TO NEAR 70 WEST. SLIGHTLY
COOLER TEMPS FOR MONDAY...ESPECIALLY BEHIND BOUNDARY IN WEST...BUT
IN THE EAST WEVMAY NEED TO DROP TEMPS A LITTLE MORE IN THE EAST IF IT
LOOKS LIKE CLOUDS AND SHOWERS WILL NOT GIVE WAY TO ANY SUNSHINE AT
ALL DURING THE DAY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1230 PM EDT FRIDAY...
THE WEATHER PATTERN THROUGH MUCH OF NEXT WEEK WILL BE INFLUENCED BY
BOTH A STRONG RIDGE OF WARM HIGH PRESSURE OVER MUCH OF THE COUTH
CENTRAL PORTIONS OF THE COUNTRY...AS WELL AS A DEVELOPING WEAK
TROUGH ACROSS THE NORTHEAST WITH ASSOCIATED SLOW MOVING WEAK FRONTAL
BOUNDARYS MOVING IN FROM THE NORTHWEST. THESE FEATURES WILL KEEP TEMPERATURES
NEAR SEASONABLE READINGS THROUGH THE WEEK...WITH A CONTINUING CHANCE
FOR SHOWERS AND THUNDERSTORMS ON MOST DAYS.
MORE SPECIFICALLY...THE FRONTAL BOUNDARY SLOWLY MOVING ACROSS THE
APPALACHIAN REGION ON MONDAY WILL LIKELY BE LINGERING ACROSS THE
PIEDMONT INTO MONDAY NIGHT AND TUESDAY...BEFORE WASHING OUT ACROSS
THE CAROLINAS. THERE ARE SIGNS IN SOME OF THE GUIDANCE OF A WEAK
WAVE MOVING UP FROM THE SOUTHWEST...SO WHILE EXPECTING BETTER
COVERAGE OF SHOWERS AND STORMS CLOSER TO THE FRONT IN THE EASTERN
HALF OF THE FCST AREA TUESDAY...CAN ELIMINATE CHANCES FARTHER WEST
GIVEN THIS POSSIBLE WAVE. WITH FAIRLY GOOD CLOUD COVER LIKELY...THIS
COULD BE COOLEST DAY OF THE WEEK FOR SOME AREAS. WEDNESDAY WILL HAVE
LESS OF A FOCUSING MECHANISM...BUT WITH WEAK TROUGH DEVELOPING
OVERHEAD...AND MORE SUNSHINE PROBABLE...COULD RESULT IN STEEPER
LAPSE RATES OVERALL...SO WORTH KEEPING CHC FOR SCATTERED AFTERNOON
CONVECTION. PROBABLY BETTER CHANCES ACROSS THE SOUTHEAST...IF
LINGERING CONVERGENCE WITH OLD BOUNDARY IS STILL PRESENT. BY THURS
AND FRIDAY WILL HAVE TO RELY MORE ON DAYTIME HEATING AND LINGERING
LOW LEVEL MSTR...BUT WITH WEAK TROUGH ALOFT AND NO PUSH OF DRIER AIR
EVIDENT...FEEL ITS WORTH KEEPING LOW CHC POPS. ON FRIDAY THE
INFLUENCE OF ANOTHER WEAK FRONT TO THE NORTH MAY BE ENOUGH TO
PROVIDE SLIGHTLY BETTER CHANCES...BUT BY THIS TIME THERE IS ENOUGH
DIFFERENCE IN MODEL GUIDANCE...WITH SOME HOLDING THIS FRONT OFF
UNTIL SAT OR LATER...NOT TO PUT MUCH EMPHASIS ON MUCH OF A CHANGE
BETWEEN THURS AND FRIDAY. WITH GENERALLY MORE SUN BY MID TO LATE
WEEK ONCE THE FRONT FROM EARLY IN THE WEEK GOES BY AND
WEAKENS...EXPECTING A VERY GRADUAL WARMING TREND BY LATE IN THE
WEEK...WITH PIEDMONT HIGH TEMPS REACHING BACK INTO THE LOW TO MID
90S BY LATE IN THE WEEK.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
LOW CLOUDS ARE MIXING OUT IN THE NRV AND ROA VALLEYS THIS AFTERNOON.
AREA OF CONVECTION TO OUR WEST MOVING EAST TOWARD THE MOUNTAINS.
MVFR CONDITIONS EXPECTED IN LOW CLOUDS AND CONVECTION THIS
AFTERNOON INTO TONIGHT. MODELS EMPHASIZE A SHRTWV MOVING INTO FAR
WRN VA/NC LATE IN THE DAY. THIS MAY PRODUCE SCT STORMS...BUT LOW
CONFIDENCE ON EXACT TIME OF IMPACT FOR ANY OF TERMINALS. WILL
MAINTAIN VCTS WITH THE BEST CHANCE EXPECTED AFTER 20Z/4PM. MEAN
WINDS ALOFT ARE 10 KTS OR LESS...SO ANY SHRA/TSRA THAT DEVELOP
WILL BE SLOW MOVING.
DEEPER MOISTURE WILL OVERTAKE THE REGION THIS WEEKEND WITH
GREATER COVERAGE OF SHOWERS AND STORMS...ESPCLY DURING THE
AFTERNOON AND EVENING EACH DAY THROUGH MONDAY. LOCAL MVFR/IFR
CONDITIONS WILL BE ASSOCIATED WITH THE MORE ORGANIZED STORMS.
OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY
OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG.
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY
MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF
THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF
DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR
MID WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...KK
SHORT TERM...SK
LONG TERM...SK
AVIATION...KK/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
244 PM CDT FRI AUG 3 2012
.SHORT TERM...TODAY THROUGH SATURDAY.
IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO
EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD
DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z
RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN
3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT.
BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME.
SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS
MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD
RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES
TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM
TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY
INCREASING CLOUD COVER.
THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY.
WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT
WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF
UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING
DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE
STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER
SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL
LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF
INSTABILITY SATURDAY AFTERNOON.
TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH
ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N
WITH MORE CLOUDS AND PRECIP TO START THE DAY.
ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR
TWEAKING WAS NEEDED.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND
CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY.
...SATURDAY NIGHT AND SUNDAY...
COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z
SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER
SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS
FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL
SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE
BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE
HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING.
AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY.
THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF
CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY
AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB
TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND
THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH
THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS
AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY
NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA.
GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH
TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH
CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY
COLD SUNDAY NIGHT.
...MONDAY THROUGH FRIDAY...
HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH
WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF
CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT
INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE.
BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE
SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO
NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK.
&&
.AVIATION...SC DISSIPATING SLOWER THAN EARLIER THOUGHT...BUT EDGES
ARE THINNING AS WEAK MIXING DRAWS SOMEWHAT DRIER AIR DOWN TO
SURFACE. VFR CONDITIONS WILL CONTINUE TO EXPAND. LIGHT EASTERLY
WIND WILL BECOME SOUTHEAST THEN SOUTH BY 12Z. SOME MVFR VSBY WITH
BR 09Z-12Z AT CENTRAL AND NE WI AIRPORTS. RHI MAY SEE CONVECTION
AHEAD OF FRONT BY 09Z BUT WILL KEEP THUNDER OUT OF TAF FOR NOW.
JKL
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JKL/WOLF