Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/13/12
AREA FORECAST DISCUSSION
NWS DENVER CO
847 PM MDT THU JUL 12 2012
.UPDATE...SHOWERS AND THUNDERSTORMS HAVE COME TO AN END ACROSS THE
FORECAST AREA...SO WILL CLEAN OUT THE MENTION OF PRECIPITATION
FROM THE EVENING UPDATE. SKIES SHOULD BECOME MOSTLY CLEAR BY
MIDNIGHT AND REMAIN THAT WAY THROUGH THE MORNING HOURS. HIGH
PRESSURE ALOFT AND WEAK SURFACE PRESSURE GRADIENTS WILL BE IN
PLACE FOR FRIDAY...WHICH WILL MAKE ANY CONVECTION THAT DEVELOPS
SLOW MOVING IN NATURE.
&&
.AVIATION...NO AVIATION IMPACTS EXPECTED TONIGHT. WEAK DIURNAL
WINDS WILL DEVELOP OVER THE NEXT COUPLE HOURS AND CONTINUE THROUGH
SUNRISE. SURFACE PRESSURE GRADIENTS TOMORROW WILL BE WEAK...
LEADING TO LIGHT WINDS IN THE MORNING AND AN EASTERLY WIND REGIME
THROUGH FRIDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 331 PM MDT THU JUL 12 2012/
SHORT TERM...IN THE VERY SHORT TERM...MONITORING A LINE OF
CUMULUS/TOWERING CUMULUS BUILDING ALONG A SFC CONVERGENCE
BOUNDARY ALIGNED ACROSS SOUTHEAST ELBERT...NORTHERN LINCOLN...
SOUTHEAST WASHINGTON AND EASTERN PORTIONS OF PHILLIPS AND
SEDGWICK COUNTIES. LOWER/MID 50 DEWPTS POOLED ALONG THIS
LINE OF WITH THE 18Z/RUC INDICATING CAPES IN THE 1500-2000 J/KG
RANGE IN THE AREA. HOWEVER THE RUC WAS ALSO INDICATING
CIN/CONVECTIVE INHIBITION/ VALUES IN THE 40-80 J/KG IN THE AREA.
ONE REASON FOR THE SLUGGISH CONVECTIVE DEVELOPMENT OUT THAT WAY.
OTHERWISE HEAT GENERATED ISOLATED T-STORMS POPPING UP IN THE HIGH
COUNTRY GENERALLY LOW INTENSITY. LIGHT RAIN SHOWERS...CG
LIGHTNING AND GUSTY WINDS PRETTY MUCH ALL WE/VE SEEN SO FAR
THIS AFTERNOON. TRAJECTORY OF STORMS SHIFTED FROM SOUTHEASTERLY
TO SOUTHERLY EARLY IN THE AFTERNOON WITH THE UPPER RIDGE OUT WEST
NOSE EASTWARD OVER COLORADO. CURRENT PRECIPITABLE WATER VALUES
ALONG THE FRONT RANGE LOWER THAN 24 HRS AGO BY ABOUT 0.10
INCH...BUT UP SLIGHTLY IN THE PAST 1-2 HOURS WITH LIGHT
NORTHEASTERLY UPSLOPE FLOW. SHOULD COULD TO SEE FURTHER STORM
DEVELOPMENT IN THE HIGH COUNTRY AND ALONG THE CONVERGENCE BOUNDARY
ON THE PLAINS DURING THE NEXT 2-4 HOURS. WITH ALL THE PENT UP
ENERGY ALONG THE PLAINS BOUNDARY...WOULD NOT BE SURPRISED TO SEE A
FEW STORMS GENERATE HAIL AT LEAST 3/4 INCH IN DIAMETER...RAINFALL
RATES UP TO 0.75 INCH PER HOUR...AND OUTFLOW WIND GUSTS TO 50 MPH.
PROBABLY BEST CHANCE FOR THIS OCCURRING IS UP NEAR THE NORTHEAST
CORNER WHERE GREATEST CAPE VALUES NOW EXIST.
FOR TONIGHT...AFTER THE ISOLATED STORMS DESCRIBED ABOVE DISSIPATE
SOMETIME AROUND 20-21Z...SHOULD SEE SKIES CLEAR AND THE
DEVELOPMENT OF A TYPICAL NOCTURNAL DRAINAGE WIND PATTERN IN AND
NEAR THE HIGH TERRAIN...AND A SOUTHERLY WIND OF 8-15KT FARTHER OUT
ACROSS THE PLAINS. LOOK FOR LOWS TONIGHT NEAR SEASONAL VALUES.
ON FRIDAY...THE HOT UPPER RIDGE OUT WEST AT THE MOMENT MIGRATES
EASTWARD OVER COLORADO...RESULTING IN A MUCH LIGHTER FLOW ALOFT
AND LIGHTER WINDS AT THE SURFACE. WARMING ALOFT FURTHER
STABILIZES THE BOUNDARY LAYER ESPECIALLY OVER THE PLAINS.
THEREFORE CHANCES FOR STORMS AT LOWER ELEVATIONS LOWER THAN TODAY.
IN THE HIGH COUNTRY CHANCES ABOUT THE SAME...BUT ANY STORMS THAT
MANGE TO FORM IN THIS SLIGHTLY DRIER AND POORLY SHEARED ATMOSPHERE
NOT EXPECTED TO REMAIN INTACT FOR LONG. HIGH TEMPERATURES ON
FRIDAY 1-2C HIGHER THAN TODAY. COULD SEE THE MERCURY PUSHING THE
CENTURY MARK ALONG THE SOUTH PLATTE RIVER NORTHEAST OF DENVER.
LONG TERM...A FEW STORMS WILL BE POSSIBLE ACROSS THE HIGHER
TERRAIN FRIDAY EVENING WHERE WEAK UPSLOPE WILL PERSIST. CAPES
MINIMAL...GENERALLY AROUND 200 J/KG...SO ANY STORMS WILL BE WEAK.
PRECIPITABLE WATER VALUES AROUND SIX TENTHS OF AN INCH...SO ONLY
LIGHT RAINFALL EXPECTED. MODELS SHOW UPPER RIDGE AXIS CENTERED
OVER COLORADO BEGINS TO SHIFT A BIT EASTWARD INTO EASTERN COLORADO
OVERNIGHT FRIDAY INTO SATURDAY. FLOW ALOFT TO BECOME MORE
SOUTHWEST ALLOWING FOR SOME INCREASE IN MOISTURE ACROSS AREA. A
FEW STORMS COULD LINGER BEYOND MIDNIGHT BUT WILL BE FIGHTING
SUBSIDENCE. ON SATURDAY...BOTH NAM AND GFS CONTINUE TO SHOW AN
INCREASE IN THE MOISTURE FROM THE SOUTHWEST ACROSS THE AREA...
THOUGH THE BULK OF THE MOISTURE LOOKS TO REMAIN WEST OF COLORADO.
THERE APPEARS TO BE SOME INCREASE IN MOISTURE ACROSS CENTRAL
PLAINS AS WELL. GFS PRECIPITABLE WATER VALUES INCREASE TO AROUND
EIGHT TENTHS OF AN INCH ACROSS THE MOUNTAINS BY AFTERNOON. SHOULD
SEE STORM CHANCES INCREASE..NAM LESS WITH VALUES AROUND SEVEN TENTHS OF
AN INCH. BOTH MODELS SIMILAR ACROSS PLAINS WITH VALUES CLOSE TO AN
INCH. MODEL CROSS SECTIONS SHOWING MOST OF THIS MOISTURE ABOVE
MOUNTAIN TOP. BETTER CHANCE FOR STORMS EXPECTED BY AFTERNOON...
MAINLY ACROSS MOUNTAINS AND HIGHER FOOTHILLS. CAPE VALUES ROUGHLY
IN THE 300-500 J/KG RANGE...SO NOT EXPECTING WIDESPREAD COVERAGE.
WINDS ALOFT WILL REMAIN LIGHT SO ANY STORMS WILL BE SLOW MOVING.
THE STRONGER STORMS COULD PRODUCE MODERATE TO BRIEF HEAVY RAIN.
TEMPERATURES ACROSS PLAINS LOOK TO REACH THE MID 90S. MODELS SHOW
RIDGE AXIS SHIFTING INTO WESTERN KANSAS SUNDAY...WHICH SHOULD
ALLOW FOR A BIT MORE MOISTURE TO BE ADVECTED INTO AREA IN THE
SOUTHWEST FLOW ALOFT. MODELS INDICATE 700 MB SPECIFIC WATER VALUES
INCREASING TO AROUND 8 G/KG. INTERESTING THAT THE GFS PRECIPITABLE
WATER VALUES IS ONLY AROUND EIGHT TENTHS OF AN INCH.
ANYWAY...SHOULD SEE A GOOD CHANCE OF MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WITH THE BEST CHANCE OVER THE HIGHER TERRAIN.
STORMS TO BE SLOW MOVING AND COULD DUMP BRIEF HEAVY RAIN.
TEMPERATURES TO BE A FEW DEGREES COOLER WITH EXPECTED CLOUD COVER
AND ANTICIPATED PRECIPITATION.
PATTERN LOOKS TO CHANGE LITTLE MONDAY THROUGH THURSDAY...WITH A
CONTINUED MOISTURE FLOW FROM THE SOUTHWEST. MODELS CONTINUE TO
GENERATE QPF DURING THE AFTERNOON AND EVENING HOURS. WILL CONTINUE
THE SLIGHT CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. MODELS
CONTINUE TO HINT AT A WEAK DISTURBANCE MOVING ACROSS THE AREA
TUESDAY WHICH COULD INCREASE STORM CHANCES ALONG WITH PERHAPS A
BETTER CHANCE OF PRECIPITATION. TEMPERATURES TO REMAIN NEAR OR
SLIGHTLY ABOVE NORMAL.
AVIATION...VFR CONDITIONS ANTICIPATED AT DENVER AREA AIRPORTS
DURING THE NEXT 24 HOURS. ANY HIGH BASED CONVECTION PASSING OVER
THE DENVER METRO AREA BETWEEN 21Z/THU AND 01Z/FRI COULD STILL
PRODUCE BRIEF OUTFLOW GUSTS TO 30KTS AND SOME CLOUD-TO-GROUND
LIGHTNING...BUT LITTLE IF ANY RAINFALL. AFTER 01Z THIS EVENING...
SKIES WILL GRADUALLY CLEAR WITH TYPICAL DRAINAGE WINDS OF 7-13KT
OVERNIGHT. ON FRIDAY...THIS DRAINAGE WIND PATTERN IS EXPECTED TO
LINGER THROUGH MOST OF THE MORNING BEFORE GRADUALLY SHIFTING A
TYPICAL UPSLOPE/EAST-NORTHEAST COMPONENT OF 6-12KT IN THE
AFTERNOON. ANY THUNDERSTORMS TOMORROW EXPECTED TO REMAIN WEST-
SOUTHWEST OF THE DENVER METRO AREA.
HYDROLOGY...NO THREAT OF HEAVY RAIN OR FLASH FLOODING DURING THE
NEXT 24 HOURS. ISOLATED WEAK THUNDERSTORMS DRIFTING SOUTHWEST OVER
THE FRONT RANGE MOUNTAINS AND FOOTHILLS COULD DEPOSIT UP TO 0.25
INCH IN 45 MINUTES AND WIND GUSTS TO 35 MPH. STORMS SHOULD END IN
THE MOUNTAIN AREAS BY 8 PM THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....99
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
315 PM MDT WED JUL 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM MDT WED JUL 11 2012
SMALL DISTURBANCE MOVING INTO NE UT AT MID-AFTERNOON REACHES FAR
NW CO THIS EVENING PER RAP MODEL. HIGH-RES MODELS DO NOT SHOW MUCH
PRECIP WITH IT...CONSISTENT WITH THE DRIER AIR SHOWN THERE ON THE
19Z PRECIPITABLE WATER ANALYSIS. BUT A BIT MORE VERTICAL SHEAR
WITH THIS DISTURBANCE COULD RESULT IN LONGER LIVED STORMS THERE.
DAYTIME HEATING AND INSTABILITY APPEARED TO BE THE MAIN DRIVER OF
AFTERNOON CONVECTION ACROSS THE CENTRAL AND SOUTHERN MTNS WITH THE
DEEPER MOISTURE ACROSS THE SOUTH WHERE LOCALLY MODERATE TO HEAVY
RAIN IS POSSIBLE. STORMS WILL DRIFT OVER THE LOWER VALLEYS LATE
TODAY AND THIS EVENING. A FEW STORMS MAY PRODUCE SMALL HAIL...AS
SOME DID TUESDAY EVENING. GUSTY OUTFLOW WINDS ARE POSSIBLE FROM
ANY STORM BUT ESPECIALLY ACROSS THE NORTH WHERE FORECAST SOUNDINGS
EXHIBITED A MORE PRONOUNCED INVERTED-V SIGNATURE. CONVECTION
SHOULD DIMINISH BY LATE EVENING.
NOT MUCH CHANGE IS EXPECTED ON THU WITH SOME AFTERNOON AND EVENING
THUNDERSTORMS ONCE AGAIN. AFTERNOON TEMPS WILL CLIMB ANOTHER
COUPLE OF DEGREES WITH SOME LOWER VALLEYS IN ERN UT AND WEST-
CENTRAL CO AROUND THE 100 DEG MARK. THE UPPER RIDGE THAT HAS BEEN
ENTRENCHED OVER THE GREAT BASIN SHOULD FINALLY BEGIN SLIDING EAST
LATE THU. MODELS HAVE IT CENTERED IN THE VICINITY OF THE 4 CORNERS
BY FRI MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM MDT WED JUL 11 2012
THE HIGH PRESSURE CENTER WILL SHIFT SOUTHEAST IN RESPONSE TO LOW
PRESSURE MOVING INTO THE PACIFIC NORTHWEST LATE THIS WEEK. AS THE
HIGH SHIFTS EAST...THE SUB-TROPICAL MOISTURE PLUME WILL ALSO SHIFT
EAST FROM EASTERN NV/WESTERN UT TO EASTERN UT/WESTERN CO.
THEREFORE MOISTURE WILL BEGIN TO INCREASE OVER OUR AREA ON FRIDAY
AND DEEPEN ON SATURDAY...FOR A RETURN TO A WETTER REGIME. IN
ADDITION...THE GRADIENT WILL TIGHTEN BETWEEN THE PACIFIC LOW AND
THE HIGH PRESSURE MOVING TO OUR SOUTHEAST...FOR A MORE ENERGETIC
SOUTHWEST FLOW OVER OUR AREA. MODELS INDICATE A DISTURBANCE
ROTATING AROUND THE LOW FRI NIGHT INTO EARLY SAT MAY KEEP
CONVECTION ONGOING OVERNIGHT. BY SATURDAY THE HIGH WILL BE
CENTERED OVER NORTH-CENTRAL NM TO SOUTHEAST CO...THEN GRADUALLY
SHIFT EAST THROUGH THE FIRST HALF OF THE WORK WEEK. A MOIST AND
UNSTABLE SOUTHWEST FLOW WILL CONTINUE TO STREAM OVER THE AREA. ANY
EMBEDDED DISTURBANCES WILL ONLY ENHANCE CONVECTION. BY MIDWEEK THE
LOW SHIFTS EAST ACROSS THE NORTHERN ROCKIES AND DRIER AIR MOVES
INTO OUR AREA...ESPECIALLY OVER THE WEST-NORTHWEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 315 PM MDT WED JUL 11 2012
VFR CONDITIONS IN GENERAL EXPECTED AT THE TAF SITES THROUGH
THURSDAY AFTERNOON. ISOLATED TO SCATTERED THUNDERSTORMS AFTERNOON
AND EVENING THUNDERSTORMS WILL DIMINISH AFTER SUNSET TODAY AND ON
THU. LOCAL MVFR CONDITIONS POSSIBLE IN STORMS PRODUCING HEAVIER
RAIN. ALL THUNDERSTORMS WILL BE CAPABLE OF PRODUCING STRONG AND
ERRATIC OUTFLOW WIND GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 315 PM MDT WED JUL 11 2012
A FEW THUNDERSTORMS THIS EVENING AND AGAIN ON THURSDAY AFTERNOON
ALONG OVER THE FAR NORTH MAY PRODUCE LIGHTNING AND GUSTY WINDS BUT
LITTLE RAIN. HOWEVER THE COVERAGE OF THESE DRY STORMS IS EXPECTED
TO BE ISOLATED AT BEST...WITH SOME STORMS OVER THIS SAME PORTION
OF THE AREA PRODUCING BETTER RAINFALL. ISOLATED TO SCATTERED
STORMS OVER THE REMAINDER OF THE FORECAST AREA THROUGH THURSDAY
EVENING ARE GENERALLY EXPECTED TO BE OF THE WET VARIETY.
MOISTURE INCREASES OVER THE AREA BEGINNING ON FRIDAY AND INTO THE
WEEKEND. THEREFORE THE MAIN FIRE WEATHER CONCERN FOR LATE THIS
WEEK THROUGH EARLY NEXT WEEK WILL BE THE POTENTIAL FOR MODERATE TO
HEAVY RAIN ON RECENT BURN SCARS. ANY GOOD RAINS OVER THESE SCARS
COULD PRODUCE EXCESSIVE RUNOFF AND DEBRIS FLOWS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JAD
LONG TERM...EH
AVIATION...JAD
FIRE WEATHER...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1119 AM MDT WED JUL 11 2012
.UPDATE...
ISSUED AT 1104 AM MDT WED JUL 11 2012
SEE FIRE WEATHER DISCUSSION BELOW.
UPDATE ISSUED AT 1048 AM MDT WED JUL 11 2012
SATELLITE REVEALED A DISTURBANCE PUSHING ACROSS NRN UT THIS MORNING
GENERATING SOME CLOUDS AND A FEW LIGHTNING STRIKES. RAP MODEL SHOWS
IT REACHING NW CO LATE TODAY. EXPECT THIS TO TRIGGER SCATTERED
THUNDERSTORMS OVER THE UINTA MTNS AGAIN TODAY...SOME OF WHICH WILL
MOVE OFF OVER THE LOWER VALLEYS OF NW CO. DISTURBANCE MAY INCREASE
SHEAR ENOUGH THAT SOME STORMS COULD ALSO BE LONGER LIVED. HAVE ADDED
MENTION OF AT LEAST ISOLATED THUNDERSTORMS TO THE LOWER ELEVATIONS
OF NE UT/NW CO THIS AFTERNOON AS A RESULT. OTHERWISE...ANTICIPATE A
DAY SIMILAR TO YESTERDAY ACROSS THE CENTRAL AND SOUTH WHERE DAYTIME
HEATING SHOULD BE THE MAIN DRIVER OF AFTERNOON CONVECTION. SURFACE
DEWPOINTS CONTINUE TO LOWER. FORECAST SOUNDINGS EXHIBIT SOME SEMBLANCE
OF AN INVERTED-V SIGNATURE FOR THE POTENTIAL OF GUSTY OUTFLOW WINDS.
DEEPEST MOISTURE REMAINS ACROSS THE SOUTH WHERE LOCALLY MODERATE TO
HEAVY RAIN IS POSSIBLE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 410 AM MDT WED JUL 11 2012
HIGH PRESSURE WILL BE PARKED OVER UTAH TODAY WITH MOISTURE
CIRCULATING AROUND IN A CLOCKWISE FASHION. IN THE WEAKLY SHEARED
ENVIRONMENT...STORMS WILL PRIMARILY HUG THE HIGHER TERRAIN
ALTHOUGH ISOLATED STORMS MAY DRIFT OVER THE LOWER VALLEYS. THE
BEST CHANCE OF THIS OCCURRING WILL BE OVER SOUTHWEST COLORADO
WHERE MOISTURE IS DEEPER. SCATTERED STORMS THAT FIRE OVER THE SAN
JUAN MOUNTAINS WILL DRIFT TOWARD THE SOUTHWEST AND IMPACT THE
LOWER VALLEYS...INCLUDING CORTEZ AND DURANGO. ENOUGH MOISTURE
WITH PWATS IN THE 0.75 RANGE AND INSTABILITY REMAIN FOR STORMS TO
LAST UNTIL AROUND MIDNIGHT BEFORE TAPERING OFF. THE RIDGE OF HIGH
PRESSURE WILL REMAIN CENTERED OVER THE CWA WITH MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN ON THURSDAY.
PWATS WILL BE IN THE 0.5 TO 0.7 RANGE ACROSS MOST OF THE CWA FOR
HIGH BASED THUNDERSTORMS WITH GUSTY OUTFLOW WINDS AND LIGHTNING
THE BIGGEST CONCERNS. THE EXCEPTION TO THIS WILL BE SW COLORADO
AND SE UTAH WHERE PWATS WILL BE BETWEEN 0.75 AND 0.8 INCHES FOR
SOME BRIEF HEAVY RAINERS AND SMALL HAIL PRODUCERS. STORMS LOOK TO
OCCUR AMONG THOSE SOUTHERN VALLEYS AGAIN AND LAST INTO THE EVENING
WITH MOISTURE AND INSTABILITY GREATEST THERE. ABOVE NORMAL
TEMPERATURES WILL BE FELT ON THURSDAY WITH TRIPLE DIGIT HEAT IN
SOME OF THE LOWER VALLEYS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 AM MDT WED JUL 11 2012
A LOW PRESSURE SYSTEM WILL MOVE ONTO THE PACIFIC NORTHWEST COAST
THURSDAY NIGHT INTO FRIDAY HELPING TO PUSH THE RIDGE OF HIGH
PRESSURE FURTHER EASTWARD. THIS WILL ALLOW THE MOISTURE PLUME TO
SHIFT FROM OVER NEVADA AND WESTERN UTAH INTO EASTERN UTAH AND
WESTERN COLORADO FOR FRIDAY. PWATS WILL INCREASE TO AROUND AN INCH
LATE FRIDAY AFTERNOON INTO THE EVENING AND BE OVER AN INCH FRIDAY
NIGHT...ESPECIALLY ACROSS EASTERN UTAH. IN ADDITION TO THE
MOISTURE...A 40 TO 50 KT JET STREAK WILL MOVE THROUGH THE RIDGE OF
HIGH PRESSURE LATE IN THE DAY ON FRIDAY PROVIDING SOME FORCING TO
THE CWA. ALL OF THESE INGREDIENTS WILL LEAD TO INCREASED COVERAGE OF
SHOWERS AND THUNDERSTORMS ACROSS MOST OF THE CWA WITH STORMS
INITIALLY OVER THE HIGHER TERRAIN AND SPREADING INTO THE ADJACENT
VALLEYS BY MID TO LATE AFTERNOON. THESE STORMS ON FRIDAY WILL BE
CAPABLE OF PRODUCING SOME WETTING RAINS ALONG WITH GUSTY OUTFLOW
WINDS AND SMALL HAIL. STORM MOTION WILL BE ABOUT 10 KTS SO FLASH
FLOODING COULD BE POSSIBLE ESPECIALLY IF ANY STORMS SIT OVER ALREADY
BURNED AREAS FROM RECENT WILDFIRES. STORMS WILL BE MORE LIKELY TO
LAST INTO THE EVENING AND OVERNIGHT ON FRIDAY AS MOISTURE CONTINUES
TO INCREASE. TEMPERATURES ON FRIDAY WILL BE COOLER WITH CLOSER TO
NORMAL READINGS DUE TO INCREASED CLOUDS AND SHOWERS.
SATURDAY THROUGH TUESDAY...WITH HIGH PRESSURE STAYING EAST OF
COLORADO..SUBTROPICAL MONSOONAL PLUME WILL CONTINUE TO STREAM OVER
THE FORECAST AREA. THE WETTEST DAY WILL BE SATURDAY DUE TO SHORT
WAVE ENERGY PROVIDING SOME DYNAMICAL FORCING AND INCREASED SHEAR.
BUT THE REMAINING DAYS WILL STAY MOIST AND CONDITIONALLY UNSTABLE
WITH DIURNALLY DRIVEN CONVECTION FORMING OVER THE HIGH TERRAIN.
WITH THE MEAN FLOW FROM THE SOUTHWEST...STORMS WILL TRACK TOWARD
THE NORTHEAST AND OCCASIONALLY AFFECT THE LOWER VALLEYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1048 AM MDT WED JUL 11 2012
VFR CONDITIONS EXPECTED IN GENERAL AT THE TAF SITES. CONVECTIVE
BUILDUPS OVER THE HIGHER TERRAIN AGAIN THIS AFTERNOON WILL LEAD TO
ISOLATED TO SCATTERED THUNDERSTORMS THAT WILL THEN DRIFT OVER THE
VALLEYS. LOCAL MVFR CONDITIONS POSSIBLE FROM STORMS PRODUCING HEAVIER
RAIN. ALL THUNDERSTORMS WILL BE CAPABLE OF PRODUCING STRONG AND
ERRATIC OUTFLOW WIND GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 1119 AM MDT WED JUL 11 2012
WITH SURFACE DEWPOINTS DOWN A LITTLE...AND AN INVERTED V
SIGNATURE TO FORECAST SOUNDINGS UP NORTH...A FEW OF THE
THUNDERSTORMS THAT FORM ALONG THE NORTHERN BORDERS OF NORTHWEST
COLORADO AND NORTHEAST UTAH COULD BE DRY. ALSO LIGHTNING ON THE
EDGES OF THUNDERSTORMS THAT DO PRODUCE WETTING RAINS COULD PRODUCE
A FEW FIRE STARTS. HOWEVER COVERAGE OF DRY STORMS STILL EXPECTED
TO REMAIN ISOLATED...SO WILL NOT HOIST ANY FIRE WEATHER HIGH
LIGHTS AT THIS TIME. IN ADDITION...THUNDERSTORMS IN THIS INVERTED
V ENVIRONMENT ARE APT TO PRODUCE STRONG GUSTY OUTFLOW WINDS. SEE
UPDATE SECTION ISSUED AT 1048 AM MDT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...PF/MA
LONG TERM...MA/PF
AVIATION...JAD
FIRE WEATHER...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1050 AM MDT WED JUL 11 2012
.UPDATE...
ISSUED AT 1048 AM MDT WED JUL 11 2012
SATELLITE REVEALED A DISTURBANCE PUSHING ACROSS NRN UT THIS MORNING
GENERATING SOME CLOUDS AND A FEW LIGHTNING STRIKES. RAP MODEL SHOWS
IT REACHING NW CO LATE TODAY. EXPECT THIS TO TRIGGER SCATTERED
THUNDERSTORMS OVER THE UINTA MTNS AGAIN TODAY...SOME OF WHICH WILL
MOVE OFF OVER THE LOWER VALLEYS OF NW CO. DISTURBANCE MAY INCREASE
SHEAR ENOUGH THAT SOME STORMS COULD ALSO BE LONGER LIVED. HAVE ADDED
MENTION OF AT LEAST ISOLATED THUNDERSTORMS TO THE LOWER ELEVATIONS
OF NE UT/NW CO THIS AFTERNOON AS A RESULT. OTHERWISE...ANTICIPATE A
DAY SIMILAR TO YESTERDAY ACROSS THE CENTRAL AND SOUTH WHERE DAYTIME
HEATING SHOULD BE THE MAIN DRIVER OF AFTERNOON CONVECTION. SURFACE
DEWPOINTS CONTINUE TO LOWER. FORECAST SOUNDINGS EXHIBIT SOME SEMBLANCE
OF AN INVERTED-V SIGNATURE FOR THE POTENTIAL OF GUSTY OUTFLOW WINDS.
DEEPEST MOISTURE REMAINS ACROSS THE SOUTH WHERE LOCALLY MODERATE TO
HEAVY RAIN IS POSSIBLE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 410 AM MDT WED JUL 11 2012
HIGH PRESSURE WILL BE PARKED OVER UTAH TODAY WITH MOISTURE
CIRCULATING AROUND IN A CLOCKWISE FASHION. IN THE WEAKLY SHEARED
ENVIRONMENT...STORMS WILL PRIMARILY HUG THE HIGHER TERRAIN
ALTHOUGH ISOLATED STORMS MAY DRIFT OVER THE LOWER VALLEYS. THE
BEST CHANCE OF THIS OCCURRING WILL BE OVER SOUTHWEST COLORADO
WHERE MOISTURE IS DEEPER. SCATTERED STORMS THAT FIRE OVER THE SAN
JUAN MOUNTAINS WILL DRIFT TOWARD THE SOUTHWEST AND IMPACT THE
LOWER VALLEYS...INCLUDING CORTEZ AND DURANGO. ENOUGH MOISTURE
WITH PWATS IN THE 0.75 RANGE AND INSTABILITY REMAIN FOR STORMS TO
LAST UNTIL AROUND MIDNIGHT BEFORE TAPERING OFF. THE RIDGE OF HIGH
PRESSURE WILL REMAIN CENTERED OVER THE CWA WITH MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN ON THURSDAY.
PWATS WILL BE IN THE 0.5 TO 0.7 RANGE ACROSS MOST OF THE CWA FOR
HIGH BASED THUNDERSTORMS WITH GUSTY OUTFLOW WINDS AND LIGHTNING
THE BIGGEST CONCERNS. THE EXCEPTION TO THIS WILL BE SW COLORADO
AND SE UTAH WHERE PWATS WILL BE BETWEEN 0.75 AND 0.8 INCHES FOR
SOME BRIEF HEAVY RAINERS AND SMALL HAIL PRODUCERS. STORMS LOOK TO
OCCUR AMONG THOSE SOUTHERN VALLEYS AGAIN AND LAST INTO THE EVENING
WITH MOISTURE AND INSTABILITY GREATEST THERE. ABOVE NORMAL
TEMPERATURES WILL BE FELT ON THURSDAY WITH TRIPLE DIGIT HEAT IN
SOME OF THE LOWER VALLEYS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 AM MDT WED JUL 11 2012
A LOW PRESSURE SYSTEM WILL MOVE ONTO THE PACIFIC NORTHWEST COAST
THURSDAY NIGHT INTO FRIDAY HELPING TO PUSH THE RIDGE OF HIGH
PRESSURE FURTHER EASTWARD. THIS WILL ALLOW THE MOISTURE PLUME TO
SHIFT FROM OVER NEVADA AND WESTERN UTAH INTO EASTERN UTAH AND
WESTERN COLORADO FOR FRIDAY. PWATS WILL INCREASE TO AROUND AN INCH
LATE FRIDAY AFTERNOON INTO THE EVENING AND BE OVER AN INCH FRIDAY
NIGHT...ESPECIALLY ACROSS EASTERN UTAH. IN ADDITION TO THE
MOISTURE...A 40 TO 50 KT JET STREAK WILL MOVE THROUGH THE RIDGE OF
HIGH PRESSURE LATE IN THE DAY ON FRIDAY PROVIDING SOME FORCING TO
THE CWA. ALL OF THESE INGREDIENTS WILL LEAD TO INCREASED COVERAGE OF
SHOWERS AND THUNDERSTORMS ACROSS MOST OF THE CWA WITH STORMS
INITIALLY OVER THE HIGHER TERRAIN AND SPREADING INTO THE ADJACENT
VALLEYS BY MID TO LATE AFTERNOON. THESE STORMS ON FRIDAY WILL BE
CAPABLE OF PRODUCING SOME WETTING RAINS ALONG WITH GUSTY OUTFLOW
WINDS AND SMALL HAIL. STORM MOTION WILL BE ABOUT 10 KTS SO FLASH
FLOODING COULD BE POSSIBLE ESPECIALLY IF ANY STORMS SIT OVER ALREADY
BURNED AREAS FROM RECENT WILDFIRES. STORMS WILL BE MORE LIKELY TO
LAST INTO THE EVENING AND OVERNIGHT ON FRIDAY AS MOISTURE CONTINUES
TO INCREASE. TEMPERATURES ON FRIDAY WILL BE COOLER WITH CLOSER TO
NORMAL READINGS DUE TO INCREASED CLOUDS AND SHOWERS.
SATURDAY THROUGH TUESDAY...WITH HIGH PRESSURE STAYING EAST OF
COLORADO..SUBTROPICAL MONSOONAL PLUME WILL CONTINUE TO STREAM OVER
THE FORECAST AREA. THE WETTEST DAY WILL BE SATURDAY DUE TO SHORT
WAVE ENERGY PROVIDING SOME DYNAMICAL FORCING AND INCREASED SHEAR.
BUT THE REMAINING DAYS WILL STAY MOIST AND CONDITIONALLY UNSTABLE
WITH DIURNALLY DRIVEN CONVECTION FORMING OVER THE HIGH TERRAIN.
WITH THE MEAN FLOW FROM THE SOUTHWEST...STORMS WILL TRACK TOWARD
THE NORTHEAST AND OCCASIONALLY AFFECT THE LOWER VALLEYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1048 AM MDT WED JUL 11 2012
VFR CONDITIONS EXPECTED IN GENERAL AT THE TAF SITES. CONVECTIVE
BUILDUPS OVER THE HIGHER TERRAIN AGAIN THIS AFTERNOON WILL LEAD TO
ISOLATED TO SCATTERED THUNDERSTORMS THAT WILL THEN DRIFT OVER THE
VALLEYS. LOCAL MVFR CONDITIONS POSSIBLE FROM STORMS PRODUCING HEAVIER
RAIN. ALL THUNDERSTORMS WILL BE CAPABLE OF PRODUCING STRONG AND
ERRATIC OUTFLOW WIND GUSTS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...PF/MA
LONG TERM...MA/PF
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS ALBANY NY
1033 PM EDT THU JUL 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO SATURDAY WITH MAINLY
FAIR WEATHER AND GRADUALLY INCREASING TEMPERATURES AND
HUMIDITY...AND ONLY A WIDELY ISOLATED SHOWER OR THUNDERSTORM
POSSIBLE. A WEATHER DISTURBANCE WILL MOVE FROM THE OHIO VALLEY
TOWARDS OUR REGION ON SATURDAY. IT WILL BRING A THREAT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS LATE SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A LIGHT SHOWER OR TWO DEVELOPING TO THE WEST OF THE CWA TONIGHT
OVER CORTLAND COUNTY MOVING TOWARD MADISON COUNTY. THIS ACTIVITY
LOOKS TO BE ELEVATED AS CLOUD BASES THERE ARE MID LEVELS. PERHAPS
SOME MID LEVEL COOLING OF THE CLOUD TOPS CONTRIBUTING TO SOME
INSTABILITY IN THIS REGION. RUC SHOWS BETTER ELEVATED INSTABILITY
/NEGATIVE SHOWALTERS/ THIS AREA AS WELL. EXPECTATION IS FOR THIS
ACTIVITY TO NOT MAKE IT INTO THE CWA.
HAVE GONE WITH MOSTLY CLEAR SKIES OVERNIGHT...ALTHOUGH SOME HIGHER
CLOUDS WILL LIKELY WORK ACROSS THE FAR SOUTHERN PART OF THE CWA.
ADJUSTED HOURLY TEMPS/DEW POINTS/CLOUD COVER. NO CHANGES TO MINS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
BASED ON MODEL SOUNDINGS...TOMORROW LOOKS SIMILAR TO TODAY. AREAS
OF FOG WILL BURN OFF LEADING TO MOSTLY SUNNY SKIES DURING THE
MORNING. BY AFTERNOON SCATTERED TO BROKEN CUMULUS CLOUDS WILL
ONCE AGAIN DEVELOP. SOUNDINGS SHOW WELL MIXED ATMOSPHERE TOMORROW
WITH MID LEVEL CAP REMAINING IN PLACE. BECAUSE OF CAP ONLY AN
ISOLATED SHOWER OR THUNDERSTORM EXPECTED...WITH BEST CHANCES OF
DEVELOPMENT OVER HIGHER TERRAIN. MUCH LIKE TODAY...MODEL SOUNDINGS
FOR TOMORROW SHOW AROUND 10 KNOTS OF WIND UP THROUGH THE COLUMN SO
ANY SHOWERS THAT DO DEVELOP WILL BE VERY SLOW MOVING FROM NW TO
SE. ANOTHER HOT DAY EXPECTED SIMILAR TO TODAY WITH LIGHT BREEZES
AS NO WIND TO MIX DOWN.
SIMILAR CONDITIONS EXPECTED AGAIN FOR SATURDAY WITH MORNING FOG
GIVING WAY TO SUNSHINE AND HEAT. HEIGHT FALLS AND WEAK MID LEVEL
COOLING ASSOCIATED WITH APPROACHING SHORT WAVE FROM OHIO VALLEY MAY
WEAKEN THE CAP LEADING TO BETTER CHANCES ON SATURDAY FOR AFTERNOON
CONVECTION. ALSO...H850 TEMPS FORECAST TO BE WARMEST ON SATURDAY
WHICH SHOULD LEAD TO INCREASING INSTABILITY. COVERAGE STILL LOOKS TO
BE ISOLATED. BY SATURDAY NIGHT...MOISTURE FROM LOWER MISS VALLEY
STARTS TO INTERACT WITH THE SHORT WAVE APPROACHING FROM THE OHIO
VALLEY. OVERNIGHT...SHOWERS EXPECTED WITH BEST CHANCES OVER
SOUTHWESTERN AREAS. SOME TIMING DIFFERENCES WITH PRECIPITATION ONSET
WITH NAM FASTEST BRING PRECIP INTO AREA SHORTLY AFTER DARK AND EURO
SLOWEST WITH PRECIP ARRIVING TOWARDS DAYBREAK. SOME EMBEDDED THUNDER
POSSIBLE WITH SHOWERS AS FORECAST SHOWALTER VALUES ARE NEGATIVE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GETTING INTO A WARM AND UNSTABLE PATTERN WITH GENERALLY LIGHT AND
SCATTERED QPFS...AS FRONTAL BOUNDARIES AND LOW PRESSURE WAVES
REMAIN NEARBY TO OUR NORTH THROUGH MIDWEEK. SUNDAY WILL BE WETTEST
OVERALL...WITH THE ONLY REALLY DECENT CHANCES FOR SOME MUCH NEEDED
RAINFALL. THEREAFTER...MOISTURE WILL BE LIMITED...WITH THE BEST
CHANCES FOR WETTING MAINLY IN THE ADIRONDACKS. THUNDERSTORMS MAY
BE INCLUDED IN ANY SHOWER ACTIVITY THROUGH MUCH OF THE PERIOD AS
INSTABILITIES WILL BE ABOVE NORMAL FOR MOST PERIODS. WITH A
POSSIBLE FRONTAL PASSAGE AT MID-WEEK... THURSDAY COULD TURN OUT TO
BE THE COOLEST AND DRIEST DAY OF THE PERIOD.
HIGH TEMPERATURES ON SUNDAY WILL BE MOSTLY IN THE 80S...WITH FROM
AROUND 80 TO AROUND 90 THE HIGHS MONDAY THROUGH WEDNESDAY. THEN
HIGHS ON THURSDAY WILL RANGE FROM THE MID AND UPPER 70S IN THE HIGH
TERRAIN...TO THE UPPER 80S IN THE MID-HUDSON VALLEY. LOWS FROM THE
MID AND UPPER 50S IN THE HIGH TERRAIN...TO THE UPPER 60S OR AROUND
70 IN THE MID-HUDSON VALLEY...WILL BE COMMON ALL NIGHTS. MOS
GUIDANCE.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
MAINLY VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD.
EXCEPTIONS WILL BE AT KGFL AND KPSF WHERE SOME MVFR BR IS FORECAST
IN THE PRE-DAWN HOURS OF FRIDAY. DIDN/T SEE ANY OBVIS THIS MORNING
AT KGFL OR KPSF. WITH TEMP/DEW POINT SPREADS SIMILAR TO
YESTERDAY...AND CONTINUED VERY DRY CONDITIONS WILL NOT FORECAST
ANY IFR CONDITIONS AT KGFL TONIGHT.
OUTLOOK...
FRI NITE...VFR. NO SIG WX. SOME PATCHY BR/FG IS POSSIBLE FRIDAY
MORNING.
SAT-MON...VFR/MVFR. ISOLD- SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL DOMINATE OUR WEATHER INTO SATURDAY WITH MAINLY
FAIR WEATHER AND GRADUALLY INCREASING TEMPERATURES AND
HUMIDITY...AND ONLY A WIDELY ISOLATED SHOWER OR THUNDERSTORM
POSSIBLE. A WEATHER DISTURBANCE WILL MOVE FROM THE OHIO VALLEY
TOWARDS OUR REGION ON SATURDAY. IT WILL BRING A THREAT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS LATE SATURDAY INTO SUNDAY.
RELATIVE HUMIDITY VALUES WILL RECOVER TO BETWEEN 80 TO 100
PERCENT EACH NIGHT...THEN DROP BACK TO BETWEEN 30 AND 50 PERCENT
EACH AFTERNOON THROUGH SATURDAY.
SURFACE WINDS WILL BE LIGHT AND VARIABLE AND 10 MPH OR LESS.
&&
.HYDROLOGY...
MAINLY DRY WEATHER WILL CONTINUE INTO SATURDAY AS HIGH PRESSURE
DOMINATES WITH ONLY ISOLATED SHOWERS OR THUNDERSTORMS. MOST RIVER
AND STREAM FLOWS ARE BELOW NORMAL FOR JULY.
THERE IS AN INCREASING THREAT FOR SHOWERS AND THUNDERSTORMS
SATURDAY NIGHT INTO SUNDAY. PRECIPITATION IS FORECAST TO BE 0.25
TO 0.50 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE FROM
THUNDERSTORMS. MINOR RISES ARE EXPECTED ON THE RIVERS EXCEPT WHERE
HEAVIER DOWNPOURS OCCUR FROM THUNDERSTORMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SND
NEAR TERM...OKEEFE
SHORT TERM...SND
LONG TERM...ELH
AVIATION...OKEEFE
FIRE WEATHER...SND
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
158 PM EDT WED JUL 11 2012
.SYNOPSIS...
WEAK SURFACE HIGH PRESSURE WILL REMAIN IN PLACE THROUGH
FRIDAY...WHILE WEAK OFFSHORE LOW PRESSURE PASSES TO THE SOUTH AND
EAST. THE HIGH WILL MOVE OFFSHORE LATE FRIDAY... ALLOWING A RETURN
OF HEAT AND HUMIDITY FOR THE WEEKEND INTO EARLY NEXT WEEK...ALONG
WITH SCATTERED CONVECTION SATURDAY NIGHT AND AGAIN SUNDAY
AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A 500 HPA SHORTWAVE PASSES JUST TO OUR N THIS AFTERNOON BASED ON
LATEST WATER VAPOR AND RUC ANALYSIS...WHILE AT 700 HPA A VORTICITY
MINIMUM ROTATES AROUND THE AREA. THE RESULT WILL BE NET SLIGHTLY
NEGATIVE DYNAMICALLY FORCING. THIS COUPLED WITH ONLY A FEW HUNDRED
J/KG OF CAPE FORECAST THIS AFTERNOON LEADS TO LITTLE CONFIDENCE
THERE WILL BE ENOUGH THERMODYNAMIC ENERGY TO OVERCOME THE MID LEVEL
NEGATIVE FORCING...SO HAVE CONTINUED WITH A DRY FORECAST. AN
ISOLATED -SHRA/TSTM OVER FAR WESTERN ZONES CANNOT BE COMPLETELY
RULED OUT HOWEVER...BUT WITH ONLY A 5-10 PERCENT CHANCE OF
OCCURRENCE IT CANNOT BE REFLECTED IN THE FORECAST.
FOR HIGHS THIS AFTERNOON...WILL HAVE A SEABREEZE ENHANCED SE FLOW
THIS AFTERNOON...WHICH WILL CUTOFF DEEP MIXING FROM S TO N.
UPDATED HIGHS WITH A BLEND OF MIXING DOWN FROM 875 HPA NEAR THE
IMMEDIATE COAST...775 HPA WELL INLAND AND 825 HPA IN
BETWEEN...WITH NAM 2-METER TEMPERATURES...6Z MAV AND 00Z MET
GUIDANCE. THIS PRODUCE RESULTS FAIRLY CONSISTENT WITH 12Z
SOUNDINGS SUGGESTING HIGHS IN THE LOWER 80S NEAR THE COAST AND MID
TO MAYBE UPPER 80S ACROSS THE INTERIOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
SKIES SHOULD BE MOSTLY CLEAR TONIGHT AFTER ANY DAYTIME CONVECTION
NORTH/WEST OF NYC WANES. THIS PLUS LIGHT WINDS WILL LEAD TO FAIRLY
GOOD RADIATIONAL COOLING...WITH MORE WIDESPREAD LOWS IN THE 50S
ACROSS THE INTERIOR AND THE LONG ISLAND PINE BARRENS...60S MOST
ELSEWHERE...AND AROUND 70 IN NYC.
THU SHOULD ALSO BE MOSTLY SUNNY...WITH WEAK DOWNSLOPE FLOW IN THE
WAKE OF WEAK LOW PRESSURE PASSING OFF TO THE EAST. THIS PLUS
RISING HEIGHTS ALOFT SHOULD LEAD TO A WARMER DAY...WITH MOST
PLACES TOPPING OUT IN THE MID AND UPPER 80S. GFS SUGGESTION OF
ISOLD LATE DAY TSTMS WELL NORTH/WEST OF NYC LOOKS OVERDONE DUE TO
ITS LOW LEVEL DEWPOINTS SURGING TOWARD EVENING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
NO SIGNIFICANT CHANGES IN THE LONG TERM FCST THIS MORNING.
HIGH PRESSURE SETS UP OFFSHORE AS THE FRONTAL ZONE THAT HAS BEEN
ACROSS THE MID ATLANTIC BECOMES DIFFUSE ON FRIDAY. NWP SYSTEMS
SUGGEST THAT THE DIFFUSE WARM FRONT PASSES SATURDAY NGT AS WEAK
SURFACE LOW PRESSURE TRACKS EAST THROUGH THE ST LAWRENCE AND INTO
THE GULF OF MAINE OR OVER SOUTHERN MAINE SUNDAY EVE. THIS DRAGS A
WEAK COLD FRONT INTO OUR REGION WITH SFC TROUGHING. GFS AND CMC IN
GOOD AGREEMENT HERE - LATEST 00Z ECMWF STILL DOES NOT HAVE THIS FOR
SOME REASON. THE 00Z GEFS THOUGH ARE IN GENERAL AGREEMENT WITH THE
OPERATIONAL GFS AND THUS AM KEEPING FORECAST IN AGREEMENT WITH
LATEST AVAILABLE GFS.
DEW POINT TEMPERATURES START IN THE LOWER 60S ON FRIDAY...BUT CLIMB
TO AN UNCOMFORTABLE 70 BY SUNDAY AS SOUTHWESTERLY FLOW SETS UP
BEHIND THE WARM FRONT WITH A TRUE MARITIME TROPICAL AIR MASS MOVES
OVER THE REGION ON SUNDAY.
AS IT STANDS NOW...IT APPEARS THERE WILL BE SOME PCPN WITH THE
PASSAGE OF THE WARM FRONT SAT EVE. THEN AGAIN SUNDAY AFTN WITH
INCREASED INSTABILITY - LI OF -2 TO -4 C AND SBCAPES OF 1500
J/KG. SEVERE DOES NOT SEEM LIKELY AS SHEAR IS LOW - PERHAPS 20 KT.
THE THREAT/CONCERN WOULD BE MORE WITH THE PWATS BEING AT OR OVER 2
INCHES AND RELATIVELY SLOW MOVING. FORTUNATELY...ANTECEDENT
CONDITIONS ARE DRY...SO THE MAIN THREAT IS URBAN IN NATURE.
THIS WOULD BE SAT NGT AND/OR SUNDAY AFTN/EVE.
WE REMAIN IN THE MT AIR MASS INTO NEXT WEEK WITH DIFFUSE BOUNDARY IN
THE REGION. SO CHANCES FOR MAINLY AFTN CONVECTION CONTINUES.
WHILE GFS SUGGESTS A RETURN TO CP AIR MASS FOR LATE IN THE WEEK -
THAT IS REALLY BEYOND THE RANGE OF PREDICTABILITY IN THIS PATTERN.
HIGHS THROUGH THE PERIOD ARE 85 TO 90...THOUGH SOME LOWER 90S FOR
THE NJ/NY METRO STAYING CLOSE TO PREVIOUS FORECAST AND GFS MOS DATA
SETS. THE HUMIDITY PUSHES HEAT INDICES INTO THE MID AND UPPER 90S
STARTING ON SUNDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR THROUGH THE PERIOD. WEAK HIGH PRESSURE WILL REMAIN OVER THE
REGION WITH AN AREA OF LOW PRESSURE PASSING SOUTH OF THE
TERMINALS.
SCT TO BKN MID AND HIGH LEVEL CLOUDS PERSIST THROUGH THE EARLY
AFTERNOON...WHILE SCATTERING OUT THIS LATE THIS AFTERNOON AND
TONIGHT
SE WINDS 5-10 KT WILL BECOME LIGHT AND VARIABLE TONIGHT. WINDS
INCREASE TO 5-12 KT TOMORROW MORNING FROM THE NORTHEAST AND WILL
GRADUALLY BECOME SOUTHERLY LATE IN THE AFTERNOON FOR THE 30 HOUR
TAF SITES.
...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)
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY-FRIDAY NIGHT...MAINLY VFR.
.SATURDAY-MONDAY...MVFR POSSIBLE IN ISO-SCT SHRA/TSRA.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SEAS SHOULD BUILD LATE TODAY INTO THU AS WEAK LOW PRESSURE PASSES
SE OF THE AREA. MODEL GUIDANCE IS TRENDING TOWARD IDEA OF A
STRONGER OFFSHORE LOW PASSING BY...WITH BRIEF SCA CONDITIONS ON
THE ERN-MOST OCEAN WATERS FOR A SHORT PD LATE TONIGHT. FOR NOW MAX
SEAS HAVE BEEN CAPPED AT 4 FT BUT WILL HAVE TO REVISIT THIS WITH
NEXT SET OF NEW GUIDANCE.
WINDS AND SEAS SHOULD REMAIN WELL BELOW SCA CRITERIA THEREAFTER.
TSTMS ARE POSSIBLE SATURDAY NIGHT AND SUNDAY AFTN.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH SATURDAY.
LOCALIZED HEAVY RAINFALL IS POSSIBLE SATURDAY NIGHT AND ON SUNDAY
AFTERNOON AS PRECIPITABLE WATER VALUES RISE TO OVER 2 INCHES.
THUNDERSTORMS WOULD BE SLOW MOVING...AROUND 15 KT...AND THUS THERE
IS A THREAT OF URBAN FLOODING WITH AN OUTSIDE CHANCE FOR FLASH
FLOODING. ANTECEDENT CONDITIONS ARE DRY...THUS RIVER FLOODING IS
UNLIKELY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/MALOIT/JST
NEAR TERM...MALOIT
SHORT TERM...GOODMAN
LONG TERM...JST
AVIATION...BC
MARINE...GOODMAN/MALOIT/JST
HYDROLOGY...GOODMAN/JST
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1239 PM EDT WED JUL 11 2012
.SYNOPSIS...
WEAK SURFACE HIGH PRESSURE WILL REMAIN IN PLACE THROUGH
FRIDAY...WHILE WEAK OFFSHORE LOW PRESSURE PASSES TO THE SOUTH AND
EAST. THE HIGH WILL MOVE OFFSHORE LATE FRIDAY... ALLOWING A RETURN
OF HEAT AND HUMIDITY FOR THE WEEKEND INTO EARLY NEXT WEEK...ALONG
WITH SCATTERED CONVECTION SATURDAY NIGHT AND AGAIN SUNDAY
AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A 500 HPA SHORTWAVE PASSES JUST TO OUR N THIS AFTERNOON BASED ON
LATEST WATER VAPOR AND RUC ANALYSIS...WHILE AT 700 HPA A VORTICITY
MINIMUM ROTATES AROUND THE AREA. THE RESULT WILL BE NET SLIGHTLY
NEGATIVE DYNAMICALLY FORCING. THIS COUPLED WITH ONLY A FEW HUNDRED
J/KG OF CAPE FORECAST THIS AFTERNOON LEADS TO LITTLE CONFIDENCE
THERE WILL BE ENOUGH THERMODYNAMIC ENERGY TO OVERCOME THE MID LEVEL
NEGATIVE FORCING...SO HAVE CONTINUED WITH A DRY FORECAST. AN
ISOLATED -SHRA/TSTM OVER FAR WESTERN ZONES CANNOT BE COMPLETELY
RULED OUT HOWEVER...BUT WITH ONLY A 5-10 PERCENT CHANCE OF
OCCURRENCE IT CANNOT BE REFLECTED IN THE FORECAST.
FOR HIGHS THIS AFTERNOON...WILL HAVE A SEABREEZE ENHANCED SE FLOW
THIS AFTERNOON...WHICH WILL CUTOFF DEEP MIXING FROM S TO N.
UPDATED HIGHS WITH A BLEND OF MIXING DOWN FROM 875 HPA NEAR THE
IMMEDIATE COAST...775 HPA WELL INLAND AND 825 HPA IN
BETWEEN...WITH NAM 2-METER TEMPERATURES...6Z MAV AND 00Z MET
GUIDANCE. THIS PRODUCE RESULTS FAIRLY CONSISTENT WITH 12Z
SOUNDINGS SUGGESTING HIGHS IN THE LOWER 80S NEAR THE COAST AND MID
TO MAYBE UPPER 80S ACROSS THE INTERIOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
SKIES SHOULD BE MOSTLY CLEAR TONIGHT AFTER ANY DAYTIME CONVECTION
NORTH/WEST OF NYC WANES. THIS PLUS LIGHT WINDS WILL LEAD TO FAIRLY
GOOD RADIATIONAL COOLING...WITH MORE WIDESPREAD LOWS IN THE 50S
ACROSS THE INTERIOR AND THE LONG ISLAND PINE BARRENS...60S MOST
ELSEWHERE...AND AROUND 70 IN NYC.
THU SHOULD ALSO BE MOSTLY SUNNY...WITH WEAK DOWNSLOPE FLOW IN THE
WAKE OF WEAK LOW PRESSURE PASSING OFF TO THE EAST. THIS PLUS
RISING HEIGHTS ALOFT SHOULD LEAD TO A WARMER DAY...WITH MOST
PLACES TOPPING OUT IN THE MID AND UPPER 80S. GFS SUGGESTION OF
ISOLD LATE DAY TSTMS WELL NORTH/WEST OF NYC LOOKS OVERDONE DUE TO
ITS LOW LEVEL DEWPOINTS SURGING TOWARD EVENING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
NO SIGNIFICANT CHANGES IN THE LONG TERM FCST THIS MORNING.
HIGH PRESSURE SETS UP OFFSHORE AS THE FRONTAL ZONE THAT HAS BEEN
ACROSS THE MID ATLANTIC BECOMES DIFFUSE ON FRIDAY. NWP SYSTEMS
SUGGEST THAT THE DIFFUSE WARM FRONT PASSES SATURDAY NGT AS WEAK
SURFACE LOW PRESSURE TRACKS EAST THROUGH THE ST LAWRENCE AND INTO
THE GULF OF MAINE OR OVER SOUTHERN MAINE SUNDAY EVE. THIS DRAGS A
WEAK COLD FRONT INTO OUR REGION WITH SFC TROUGHING. GFS AND CMC IN
GOOD AGREEMENT HERE - LATEST 00Z ECMWF STILL DOES NOT HAVE THIS FOR
SOME REASON. THE 00Z GEFS THOUGH ARE IN GENERAL AGREEMENT WITH THE
OPERATIONAL GFS AND THUS AM KEEPING FORECAST IN AGREEMENT WITH
LATEST AVAILABLE GFS.
DEW POINT TEMPERATURES START IN THE LOWER 60S ON FRIDAY...BUT CLIMB
TO AN UNCOMFORTABLE 70 BY SUNDAY AS SOUTHWESTERLY FLOW SETS UP
BEHIND THE WARM FRONT WITH A TRUE MARITIME TROPICAL AIR MASS MOVES
OVER THE REGION ON SUNDAY.
AS IT STANDS NOW...IT APPEARS THERE WILL BE SOME PCPN WITH THE
PASSAGE OF THE WARM FRONT SAT EVE. THEN AGAIN SUNDAY AFTN WITH
INCREASED INSTABILITY - LI OF -2 TO -4 C AND SBCAPES OF 1500
J/KG. SEVERE DOES NOT SEEM LIKELY AS SHEAR IS LOW - PERHAPS 20 KT.
THE THREAT/CONCERN WOULD BE MORE WITH THE PWATS BEING AT OR OVER 2
INCHES AND RELATIVELY SLOW MOVING. FORTUNATELY...ANTECEDENT
CONDITIONS ARE DRY...SO THE MAIN THREAT IS URBAN IN NATURE.
THIS WOULD BE SAT NGT AND/OR SUNDAY AFTN/EVE.
WE REMAIN IN THE MT AIR MASS INTO NEXT WEEK WITH DIFFUSE BOUNDARY IN
THE REGION. SO CHANCES FOR MAINLY AFTN CONVECTION CONTINUES.
WHILE GFS SUGGESTS A RETURN TO CP AIR MASS FOR LATE IN THE WEEK -
THAT IS REALLY BEYOND THE RANGE OF PREDICTABILITY IN THIS PATTERN.
HIGHS THROUGH THE PERIOD ARE 85 TO 90...THOUGH SOME LOWER 90S FOR
THE NJ/NY METRO STAYING CLOSE TO PREVIOUS FORECAST AND GFS MOS DATA
SETS. THE HUMIDITY PUSHES HEAT INDICES INTO THE MID AND UPPER 90S
STARTING ON SUNDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR THROUGH THE PERIOD WITH WEAK SURFACE HIGH PRESSURE REMAINING OVER
THE REGION.
SCT TO BKN MID AND HIGH LEVEL CLOUDS PERSIST THROUGH THE LATE
MORNING...WHILE SCATTERING OUT THIS AFTERNOON AND TONIGHT
LIGHT AND VARIABLE WINDS WILL BECOME SE THIS AFTERNOON 5-10 KT.
THE TIMING OF THE WIND SHIFT MAY BE OFF BY AN HOUR OR TWO.
TONIGHT...WINDS BECOME LIGHT AND VARIABLE ONCE AGAIN.
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)
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR WINDS
INCREASING ABOVE 10 KTS SOONER THAN FORECASTED.
KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THURSDAY-FRIDAY NIGHT...MAINLY VFR.
.SATURDAY-SUNDAY...MVFR POSSIBLE IN ISO-SCT SHRA/TSRA.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SEAS SHOULD BUILD LATE TODAY INTO THU AS WEAK LOW PRESSURE PASSES
SE OF THE AREA. MODEL GUIDANCE IS TRENDING TOWARD IDEA OF A
STRONGER OFFSHORE LOW PASSING BY...WITH BRIEF SCA CONDITIONS ON
THE ERN-MOST OCEAN WATERS FOR A SHORT PD LATE TONIGHT. FOR NOW MAX
SEAS HAVE BEEN CAPPED AT 4 FT BUT WILL HAVE TO REVISIT THIS WITH
NEXT SET OF NEW GUIDANCE.
WINDS AND SEAS SHOULD REMAIN WELL BELOW SCA CRITERIA THEREAFTER.
TSTMS ARE POSSIBLE SATURDAY NIGHT AND SUNDAY AFTN.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH SATURDAY.
LOCALIZED HEAVY RAINFALL IS POSSIBLE SATURDAY NIGHT AND ON SUNDAY
AFTERNOON AS PRECIPITABLE WATER VALUES RISE TO OVER 2 INCHES.
THUNDERSTORMS WOULD BE SLOW MOVING...AROUND 15 KT...AND THUS THERE
IS A THREAT OF URBAN FLOODING WITH AN OUTSIDE CHANCE FOR FLASH
FLOODING. ANTECEDENT CONDITIONS ARE DRY...THUS RIVER FLOODING IS
UNLIKELY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/JST
NEAR TERM...MALOIT
SHORT TERM...GOODMAN
LONG TERM...JST
AVIATION...BC/SEARS
MARINE...MALOIT/GOODMAN/JST
HYDROLOGY...GOODMAN/JST
AREA FORECAST DISCUSSION
NWS GOODLAND KS
245 PM MDT WED JUL 11 2012
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1202 PM MDT WED JUL 11 2012
14Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE
ACROSS THE MUCH OF THE WESTERN CONUS...WITH CENTER OF RIDGE LOCATED
OVER THE FOUR CORNERS. RUC 1.5 PVU ANALYSIS INDICATED SEVERAL SMALL
PV ANOMALIES MOVING AROUND PERIPHERY OF RIDGE INTO THE NORTHERN
PLAINS. 12Z RAOBS CONTINUED THE WARMING/DRYING TREND OBSERVED
YESTERDAY...WITH MOST SIGNIFICANT WARMING NOTED AT DNR AROUND H65.
AT THE SFC...1020MB HIGH WAS IN PLACE ACROSS THE EASTERN CWA WITH
TROUGH EXTENDING SOUTH FROM LOW ACROSS WESTERN NORTH DAKOTA.
PRIMARY FORECAST CONCERNS WILL BE TEMPS AND PRECIP CHANCES TOMORROW.
REST OF TODAY...EXPECT QUIET WEATHER TO CONTINUE THROUGH THE
AFTERNOON AS SFC HIGH SHIFTS EAST AND TROUGH BECOMES ESTABLISHED
ACROSS COLORADO. NET RESULT WILL BE FOR LIGHT WINDS TO CONTINUE
ACROSS THE EASTERN CWA WITH WINDS GRADUALLY SHIFTING TO THE SOUTH
AND INCREASING ACROSS THE WEST. TEMPS SHOULD BE SLIGHTLY WARMER
TODAY THAN YESTERDAY...BUT GIVEN MINIMAL CHANGES OBSERVED ON
SOUNDINGS DO NOT THINK THINGS WILL BE DRASTICALLY DIFFERENT TEMP
WISE. WHILE THERE IS A BIT OF INSTABILITY AND WEAK CINH TODAY...HAVE
DOUBTS THAT ANYTHING WILL DEVELOP GIVING WARMING ALOFT NOTED TO THE
NORTH OF THE AREA AND THINK DRY FORECAST STILL WARRANTED.
TONIGHT-TOMORROW...PV ANOMALY WILL MOVE INTO THE NEB PANHANDLE
THROUGH THE EVENING HOURS...INDUCING AN AREA OF WEAK WARM AIR
ADVECTION ON EDGE OF H7 THERMAL RIDGE. WHILE THERE APPEARS TO BE A
SMALL POCKET OF ELEVATED INSTABILITY IN THIS AREA...ELEVATED CINH
PROFILES REMAIN QUITE STRONG AND HAVE DOUBTS THAT OVERALL WEAK LARGE
SCALE FORCING WILL BE ENOUGH TO INITIATE ANY OVERNIGHT SHOWERS OR
STORMS. PV ANOMALY WILL BE MOVING ACROSS AREA DURING THE EARLY
AFTERNOON ON THURSDAY...WITH SFC FRONT LAGGING WELL BEHIND IT. GIVEN
LIMITED INSTABILITY AND BEST NEAR SFC FORCING ALONG FRONTAL
ZONE...HAVE DOUBTS ABOUT HOW MUCH OF A PRECIP THREAT THERE WILL BE
DURING THE AFTERNOON HOURS. SLOW STORM MOTIONS ALSO MAKE IT DOUBTFUL
THAT ANYTHING INITIATING ALONG THE FRONT WILL MAKE IT FAR INTO THE
CWA BY 00Z. AS A RESULT...HAVE DELAYED PRECIP CHANCES UNTIL AFTER
21Z IN THE NORTH AND REMOVED THEM ELSEWHERE.
FOR TEMPS...EXPECT SOUTHERLY WINDS AND INCREASING TEMPS ALOFT TO
HOLD UP LOWS A FEW DEGREES IN THE WEST...BUT WITH A PERIOD OF LIGHT
AND VARIABLE WINDS EXPECTED IN EASTERN CWA WILL NOT BE SURPRISED TO
SEE TEMPS DIP INTO THE UPPER TO MID 50S IN SOME LOCATIONS. HIGHS
WILL WARM A FEW DEGREES TOMORROW WITH MID AND UPPER 90S EXPECTED
ACROSS ENTIRE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM MDT WED JUL 11 2012
LONGER TERM GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH THE EVOLUTION
OF THE UPPER PATTERN INTO THE WEEKEND. CLOSED UPPER LOW CURRENTLY
OFF THE PACIFIC NORTHWEST COAST IS FORECAST TO MOVE ONSHORE AND
GRADUALLY CARVE OUT A SIGNIFICANT TROUGH OVER THE WESTERN THIRD OF
THE COUNTRY BY FRIDAY. AS THIS OCCURS...THE UPPER HIGH OVER UTAH
WILL SHIFT EAST TO THE PLAINS RESULTING IN A WEAK SOUTHWEST FLOW
ALOFT ACROSS THE CENTRAL HIGH PLAINS. THIS WILL OPEN THE DOOR THIS
WEEKEND FOR THE POSSIBILITY OF AFTERNOON THUNDERSTORMS FORMING OVER
THE HIGHER TERRAIN AND MOVING TOWARD THE FORECAST AREA BY EVENING.
IN THE NEARTERM...AN UPPER TROUGH NOW OVER MONTANA WILL CONTINUE TO
SLOWLY DEEPEN AS IT WORKS TOWARD THE WESTERN GREAT LAKES BY LATE
TOMORROW. THIS FEATURE AND AN ASSOCIATED SURFACE COLD FRONT WILL
RESULT IN THUNDERSTORM FORMATION THURSDAY OVER THE DAKOTAS AND
NEBRASKA WHICH WILL THEN MOVE SOUTH AND SOUTHEAST TOWARD THE
FORECAST AREA THURSDAY NIGHT. STILL SOME UNCERTAINTIES IN TERMS OF
COVERAGE BUT HAVE KEPT POPS GOING THURSDAY NIGHT.
HAVE INCLUDED LOW CHANCES OF EVENING AND OVERNIGHT THUNDERSTORMS
STARTING SATURDAY...MAINLY ACROSS THE WEST AND NORTHWEST...TO COVER
THE POTENTIAL FOR STORMS WORKING OFF THE HIGHER TERRAIN AND
ADVECTING IN. THE ECMWF CONTINUES TO KEEP THINGS DRIER THROUGH THE
EXTENDED PERIOD WHILE THE GFS IS MAYBE TOO AGGRESSIVE WITH PRECIP
CHANCES. CONFIDENCE IN WHICH DAYS HAVE THE BEST POTENTIAL REMAINS
LOW UNTIL IT BECOMES MORE APPARENT HOW THE UPPER PATTERN ULTIMATELY
EVOLVES.
TEMPERATURE GUIDANCE FROM ALL MODELS SUGGESTS A CONTINUATION OF THE
SLOW WARMING TREND INTO THE WEEKEND AS 850 MB TEMPERATURES WARM 2-3
DEGREES EACH DAY THROUGH FRIDAY AND THEN HOLD IN THE 30-32C RANGE
OVER THE WEEKEND. FORECAST AFTERNOON HIGHS WILL THEREFORE TREND
BACK INTO THE 90S TO POSSIBLY NEAR 100...BUT AT THIS TIME IT DOES
NOT APPEAR THAT A REPEAT OF THE RECORD HEAT FROM LATE JUNE WILL
RETURN DURING THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1202 PM MDT WED JUL 11 2012
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS WITH WINDS
GRADUALLY BECOMING SOUTHERLY AS SFC TROUGH DEVELOPS ACROSS EASTERN
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DLF
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS WICHITA KS
255 PM CDT WED JUL 11 2012
.DISCUSSION...
FORECAST CHALLENGE...TEMPERATURES WITH RETURN OF ANOTHER HOT AND
DRY STRETCH OF WEATHER THRU EARLY NEXT WEEK.
TONIGHT-SATURDAY
DIURNAL HEATING HAS PROMOTED AN EXTENSIVE CU FIELD MAINLY
ALONG/EAST OF THE KANSAS TURNPIKE THIS AFTERNOON. SOMEWHAT COOLER
TEMPERATURES WITHIN THE THERMAL TROF ALOFT HAS ALSO RESULTED IN A
BIT MORE INSTABILITY WITH MLCAPE VALUES OF 1000-1500 J/KG. A FEW
ISOLATED SHOWERS HAVE DEVELOPED AND LATEST RUC AND HRRR SUGGEST
THEY WILL CONTINUE THRU THE LATE AFTERNOON...SO WILL CARRY ISOLATED
MENTION UNTIL AROUND 00Z. OTHERWISE TEMPERATURES WILL WARM A BIT
UNDER SUBTLE RIDGING ALOFT INTO THURSDAY...SO EXPECT A BIT LESS
DIURNAL CU AND LITTLE CHANCE FOR MEASURABLE RAIN. AN UPPER
SHORTWAVE TROF IS STILL PROGGED TO DROP SOUTHEAST ACROSS THE
UPPER MIDWEST ON FRIDAY WITH THE TAIL END OF VORTICITY AND UPPER
JET NOSING INTO KANSAS. HOWEVER MODEST MOISTURE AND INSTABILITY
SHOULD MITIGATE OR LIMIT CONVECTIVE CHANCES TO A ROGUE/ISOLATED
NATURE SO WILL KEEP FORECAST DRY FOR NOW. THE UPPER RIDGE WILL
BUILD EAST ACROSS THE HIGH PLAINS FROM FRIDAY INTO SATURDAY WITH
TEMPERATURES CREEPING BACK ABOVE SEASONAL CLIMO AND PERHAPS
APPROACHING THE CENTURY MARK ACROSS CENTRAL KANSAS.
SUNDAY-WEDNESDAY
WHILE THE MEDIUM RANGE GENERALLY SUGGESTS HOT AND DRY CONDITIONS
THRU EARLY NEXT WEEK...SUBTLE VARIANCES IN THE HANDLING OF WEAK
TROUGHINESS WITHIN THE UPPER RIDGE DO POSE SOME CHALLENGES. THIS
IS MAINLY WITHIN THE EASTERLIES MIGRATING UNDER THE RIDGE FROM
THE LOUISIANA/TEXAS GULF COAST PERHAPS ACROSS THE SOUTHERN PLAINS
EARLY NEXT WEEK. THIS COULD TEMPER THE COMING HOT STRETCH AND AT
THE MOMENT IT DOES NOT LOOK AS BRUTAL AS WHAT WE EXPERIENCED IN
LATE JUNE. THAT SAID...MAXS AROUND THE CENTURY MARK AND HEAT
INDICES TO MATCH SEEM VERY REASONABLE AND CLOSE TO THE GOING
FORECAST.
DARMOFAL
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
QUIET AVIATION WEATHER ANTICIPATED THROUGH AT LEAST THE NEXT 24
HOURS FOR ALL TERMINALS ACROSS CENTRAL...SOUTH-CENTRAL AND
SOUTHEAST KS. LIGHT NORTHEAST SURFACE WINDS WILL TRANSITION TO
LIGHT EAST/SOUTHEASTERLY WINDS TONIGHT...AND VEERING TO MORE
SOUTHERLY AND INCREASING SLIGHTLY AFTER SUNRISE THURSDAY.
AFTERNOON HEATING WILL GIVE WAY TO FEW-SCT DIURNAL CUMULUS AROUND
FROM 6000-9000 FT AGL THIS AFTERNOON. CANNOT COMPLETELY RULE OUT A
VERY ISOLATED SHOWER/THUNDERSTORM THIS AFTERNOON IN THE VICINITY
OF KCNU...AS A WEAK UPPER IMPULSE APPROACHING FROM THE NORTH
INTERACTS WITH A WEAKLY UNSTABLE AIRMASS...BUT WILL LEAVE OUT OF
KCNU TAF DUE TO LOW PROBABILITIES AND SPARSE COVERAGE.
KLEINSASSER
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 69 96 69 96 / 0 0 0 10
HUTCHINSON 66 96 68 96 / 0 0 0 10
NEWTON 67 95 68 95 / 0 0 0 10
ELDORADO 66 95 67 95 / 0 0 0 10
WINFIELD-KWLD 67 96 69 96 / 0 0 0 10
RUSSELL 65 96 68 97 / 0 0 10 10
GREAT BEND 65 95 67 96 / 0 0 10 10
SALINA 67 96 69 96 / 0 0 0 10
MCPHERSON 66 96 68 96 / 0 0 0 10
COFFEYVILLE 68 96 69 96 / 10 10 0 10
CHANUTE 66 95 68 95 / 10 10 0 10
IOLA 66 95 68 95 / 10 10 0 10
PARSONS-KPPF 66 95 68 95 / 10 10 0 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1206 PM MDT WED JUL 11 2012
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1202 PM MDT WED JUL 11 2012
14Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE IN PLACE
ACROSS THE MUCH OF THE WESTERN CONUS...WITH CENTER OF RIDGE LOCATED
OVER THE FOUR CORNERS. RUC 1.5 PVU ANALYSIS INDICATED SEVERAL SMALL
PV ANOMALIES MOVING AROUND PERIPHERY OF RIDGE INTO THE NORTHERN
PLAINS. 12Z RAOBS CONTINUED THE WARMING/DRYING TREND OBSERVED
YESTERDAY...WITH MOST SIGNIFICANT WARMING NOTED AT DNR AROUND H65.
AT THE SFC...1020MB HIGH WAS IN PLACE ACROSS THE EASTERN CWA WITH
TROUGH EXTENDING SOUTH FROM LOW ACROSS WESTERN NORTH DAKOTA.
PRIMARY FORECAST CONCERNS WILL BE TEMPS AND PRECIP CHANCES TOMORROW.
REST OF TODAY...EXPECT QUIET WEATHER TO CONTINUE THROUGH THE
AFTERNOON AS SFC HIGH SHITS EAST AND TROUGH BECOMES ESTABLISHED
ACROSS COLORADO. NET RESULT WILL BE FOR LIGHT WINDS TO CONTINUE
ACROSS THE EASTERN CWA WITH WINDS GRADUALLY SHIFTING TO THE SOUTH
AND INCREASING ACROSS THE WEST. TEMPS SHOULD BE SLIGHTLY WARMER
TODAY THAN YESTERDAY...BUT GIVEN MINIMAL CHANGES OBSERVED ON
SOUNDINGS DO NOT THINK THINGS WILL BE DRASTICALLY DIFFERENT TEMP
WISE. WHILE THERE IS A BIT OF INSTABILITY AND WEAK CINH TODAY...HAVE
DOUBTS THAT ANYTHING WILL DEVELOP GIVING WARMING ALOFT NOTED TO THE
NORTH OF THE AREA AND THINK DRY FORECAST STILL WARRANTED.
TONIGHT-TOMORROW...PV ANOMALY WILL MOVE INTO THE NEB PANHANDLE
THROUGH THE EVENING HOURS...INDUCING AN AREA OF WEAK WARM AIR
ADVECTION ON EDGE OF H7 THERMAL RIDGE. WHILE THERE APPEARS TO BE A
SMALL POCKET OF ELEVATED INSTABILITY IN THIS AREA...ELEVATED CINH
PROFILES REMAIN QUITE STRONG AND HAVE DOUBTS THAT OVERALL WEAK LARGE
SCALE FORCING WILL BE ENOUGH TO INITIATE ANY OVERNIGHT SHOWERS OR
STORMS. PV ANOMALY WILL BE MOVING ACROSS AREA DURING THE EARLY
AFTERNOON ON THURSDAY...WITH SFC FRONT LAGGING WELL BEHIND IT. GIVEN
LIMITED INSTABILITY AND BEST NEAR SFC FORCING ALONG FRONTAL
ZONE...HAVE DOUBTS ABOUT HOW MUCH OF A PRECIP THREAT THERE WILL BE
DURING THE AFTERNOON HOURS. SLOW STORM MOTIONS ALSO MAKE IT DOUBTFUL
THAT ANYTHING INITIATING ALONG THE FRONT WILL MAKE IT FAR INTO THE
CWA BY 00Z. AS A RESULT...HAVE DELAYED PRECIP CHANCES UNTIL AFTER
21Z IN THE NORTH AND REMOVED THEM ELSEWHERE.
FOR TEMPS...EXPECT SOUTHERLY WINDS AND INCREASING TEMPS ALOFT TO HOLD
UP LOWS A FEW DEGREES IN THE WEST...BUT WITH A PERIOD OF LIGHT AND
VARIABLE WINDS EXPECTED IN EASTERN CWA WILL NOT BE SURPRISED TO SEE
TEMPS DIP INTO THE UPPER TO MID 50S IN SOME LOCATIONS. HIGHS WILL
WARM A FEW DEGREES TOMORROW WITH MID AND UPPER 90S EXPECTED ACROSS
ENTIRE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 AM MDT WED JUL 11 2012
MODELS APPEAR TO BE MORE IN LINE TONIGHT IN SHIFTING THE UPPER LEVEL
RIDGE OVER THE ROCKIES BY THE WEEKEND. BY EARLY NEXT WEEK...RIDGE
WILL GRADUALLY FLATTEN AS TROUGH MOVES INTO THE PACIFIC NORTHWEST
WITH ANOTHER RIGHT ON ITS HEELS MOVING ACROSS BRITISH COLUMBIA. BY
TUESDAY THE BROAD RIDGE WILL BE OVER THE CENTRAL PORTION OF THE
COUNTRY. UPPER LEVEL FLOW WILL TRANSITION TO SOUTHWESTERLY ONCE
AGAIN...ALLOWING MONSOONAL FLOW TO DEVELOP OVER THE SOUTHWEST AND
INTO NORTHERN HIGH PLAINS. PRECIPITATION CHANCES REMAIN TRICKY AS
MODELS DIFFER QUITE A BIT. FEEL THAT WITH SURFACE TROUGH POSITION
OVER THE AREA A SOMEWHAT UNSTABLE AIRMASS...MAY SEE SOME CONVECTION
MOVE NORTHEASTWARD FROM THE HIGHER TERRAIN. BEST CHANCES APPEAR TO
REMAIN ACROSS THE NORTHEAST PORTION OF THE CWA. A SHORTWAVE TROUGH
WILL MOVE THROUGH THE FLOW SUNDAY NIGHT INTO MONDAY MORNING AN MAY
HELP TO SUSTAIN ANY PRECIPITATION THAT IS ONGOING ACROSS EASTERN
COLORADO. SURFACE TROUGH APPROACHES THE AREA TUESDAY MORNING AS
UPPER LEVEL WAVE MOVES ACROSS THE NORTHERN PLAINS. FELT THERE WAS A
CHANCE FOR SOME CONVECTION...WITH BETTER CHANCES FURTHER NORTH INTO
NEBRASKA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1202 PM MDT WED JUL 11 2012
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS WITH WINDS
GRADUALLY BECOMING SOUTHERLY AS SFC TROUGH DEVELOPS ACROSS EASTERN
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...LOCKHART
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1050 PM EDT THU JUL 12 2012
.UPDATE...
ISSUED AT 1050 PM EDT THU JUL 12 2012
ISSUED AN UPDATE TO FRESHEN UP THE GRIDS. THE FORECAST IS IN GREAT
SHAPE AND A NEW ZFP WILL NOT BE NEEDED. SENT THE GRIDS TO NDFD.
UPDATE ISSUED AT 854 PM EDT THU JUL 12 2012
WITH THE BOUNDARY DOWN SOUTH SLOW TO GENERATE AND PUSH NORTH TO
PROVIDE SOME INSTABILITY...HAVE ISSUED AN UPDATE. PULLED THUNDER OUT
OF THE EARLY PART OF THE NIGHT TILL DAWN AS LIGHTNING STRIKES HAVE
BEEN NONEXISTENT. LATER TONIGHT AS THE LOW CONTINUES TO DEVELOP...THE
BOUNDARY WILL EVENTUALLY SLIDE NORTH BINGING SOME INSTABILITY INTO
THE AREA. A NEW ZFP WAS ISSUED AND THE FORECAST IS GOOD TO GO.
UPDATE ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 724 PM EDT THU JUL 12 2012
WITH DEVELOPING PRECIP SHIELD MOVING NORTH AND CONTINUE TO PROVIDE
AMPLE COVERAGE OF SHOWER ACTIVITY, MVFR TO IFR CONDITIONS WILL
PERSIST ACROSS THE AREA...INCLUDING THE TAF SITES...FOR MOST OF THE
NEXT 24 HOUR TAF PERIOD. WITH SOME HEATING TOMORROW...MVFR TO IFR
WILL PERSIST...BUT AS WARMER AIR TRACKS NORTH AND DAYTIME
HEATING...ADDED VCTS TO THE TAF SITES. OTHERWISE...POOR CONDITIONS
WILL PERSIST THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
854 PM EDT THU JUL 12 2012
.UPDATE...
ISSUED AT 854 PM EDT THU JUL 12 2012
WITH THE BOUNDARY DOWN SOUTH SLOW TO GENERATE AND PUSH NORTH TO
PROVIDE SOME INSTABILITY...HAVE ISSUED AN UPDATE. PULLED THUNDER OUT
OF THE EARLY PART OF THE NIGHT TILL DAWN AS LIGHTNING STRIKES HAVE
BEEN NONEXISTENT. LATER TONIGHT AS THE LOW CONTINUES TO DEVELOP...THE
BOUNDARY WILL EVENTUALLY SLIDE NORTH BINGING SOME INSTABILITY INTO
THE AREA. A NEW ZFP WAS ISSUED AND THE FORECAST IS GOOD TO GO.
UPDATE ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 724 PM EDT THU JUL 12 2012
WITH DEVELOPING PRECIP SHIELD MOVING NORTH AND CONTINUE TO PROVIDE
AMPLE COVERAGE OF SHOWER ACTIVITY, MVFR TO IFR CONDITIONS WILL
PERSIST ACROSS THE AREA...INCLUDING THE TAF SITES...FOR MOST OF THE
NEXT 24 HOUR TAF PERIOD. WITH SOME HEATING TOMORROW...MVFR TO IFR
WILL PERSIST...BUT AS WARMER AIR TRACKS NORTH AND DAYTIME
HEATING...ADDED VCTS TO THE TAF SITES. OTHERWISE...POOR CONDITIONS
WILL PERSIST THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
724 PM EDT THU JUL 12 2012
.UPDATE...
ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 724 PM EDT THU JUL 12 2012
WITH DEVELOPING PRECIP SHIELD MOVING NORTH AND CONTINUE TO PROVIDE
AMPLE COVERAGE OF SHOWER ACTIVITY, MVFR TO IFR CONDITIONS WILL
PERSIST ACROSS THE AREA...INCLUDING THE TAF SITES...FOR MOST OF THE
NEXT 24 HOUR TAF PERIOD. WITH SOME HEATING TOMORROW...MVFR TO IFR
WILL PERSIST...BUT AS WARMER AIR TRACKS NORTH AND DAYTIME
HEATING...ADDED VCTS TO THE TAF SITES. OTHERWISE...POOR CONDITIONS
WILL PERSIST THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
827 PM CDT THU JUL 12 2012
.UPDATE...
...SOUNDING DISCUSSION...
NO PROBLEMS WITH THE FLIGHT THIS EVENING. THE SOUNDING SHOWS A BIT
OF A SURFACE INVERSION IN PLACE ON THE NORTHSHORE WHICH HAS HELPED
TO QUIET THE SHOWER AND THUNDERSTORM ACTIVITY. ON THE SOUTHSHORE...
A FEW STORMS ARE CONTINUING TO FIRE IN THE METRO NEW ORLEANS AREA.
A STEADY STREAM OF MOISTURE IS WORKING INTO LOWER LEVELS FROM THE
SOUTHWEST TO THE NORTHEAST ACROSS THE AREA SO ADDITIONAL
DEVELOPMENT IS POSSIBLE AS HINTED TO BY THE HRRR MODELING. THAT
SAID...CONVECTION IS ALREADY WANING OVERALL AND THERE COULD BE
ANOTHER LULL ACROSS THE ENTIRE AREA FOR SEVERAL HOURS BEFORE
THINGS BEGIN TO DEVELOP AGAIN TOMORROW. WINDS ARE OF OUT THE
SOUTHWEST AT THE SURFACE AND INTO MID LEVELS AND ARE LIGHT AND
VARIABLE ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 69 90 71 91 / 30 60 30 60
BTR 72 91 72 91 / 30 60 30 60
ASD 72 90 72 90 / 30 50 30 50
MSY 74 90 75 90 / 30 50 30 50
GPT 73 90 73 89 / 30 50 30 50
PQL 71 92 71 90 / 30 50 30 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
98/SO
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1025 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL ALLOW FOR MOSTLY
DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY THROUGH THURSDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MIDWEST AT THE END OF
THE WEEK, PUSHING A FRONTAL BOUNDARY AND DEEPER MOISTURE INTO THE
AREA WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WITH 1030AM UPDATE...HAVE ADDED ISOLATED SHOWERS INTO SOME OHIO
COUNTIES FOR THE NEXT COUPLE OF HOURS. ALTHOUGH KPBZ RADAR IS DOWN
FOR MAINTENANCE...TPIT RADAR SHOWS SOME LIGHT ECHOES OVER GUERNSEY
AND MUSKINGUM COUNTIES...WHICH IS VERIFIED BY KRLX AND KILN.
APPARENTLY THE CLOUDS ACROSS EASTERN OHIO WILL BE WITH US FOR A
FEW MORE HOURS. WILL ALSO KNOCK TEMPS DOWN A FEW DEGREES IN THIS
AREA AS WELL. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A DRY,
ZONAL MID-LEVEL FLOW WITH A 1022MB SURFACE HIGH CENTERED ACROSS
THE GREAT LAKES. WITH THIS PATTERN IN PLACE, SKIES ARE MOSTLY CLEAR
ACROSS MOST OF THE UPPER OHIO VALLEY WITH BROKEN MID DECK CLOUDS
ADVECTING ACROSS CENTRAL OHIO.
THE FORECAST AREA WILL CONTINUES TO BE IN A ZONAL FLOW TODAY AS HIGH
PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND THE NORTHEAST.
THUS, THE FORECAST IS DRY FOR THE MAJORITY. THE ONE CAVEAT IN THE
FORECAST TODAY IS POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS AREAS SOUTHEAST OF PITTSBURGH, PARTICULARLY ACROSS
THE RIDGES. DIURNAL HEATING WITH WEAK INSTABILITY (500-1000 J/KG
SBCAPE) MAY BE ENOUGH TO DEVELOP ISOLATED LATE AFTERNOON
CONVECTION OVER THE RIDGES. TAKING THIS INTO CONSIDERATION ALONG
WITH SUPPORT FROM THE WRF-ARW AND SREF, CHC POPS ARE FORECAST
ACROSS THE SOUTHEASTERN RIDGES. ANY CONVECTION WILL QUICKLY
DIMINISH BY SUNSET WITH CLOUD COVERAGE DECREASING OVERNIGHT.
850 TEMPS WARM SLIGHTLY AND BELIEVE TREND WILL CONTINUE WITH TEMPS
WARMER THAN MAV/MET GUIDANCE. THUS, HIGHS TODAY ARE FORECAST TO WARM
INTO THE UPPER 80S ACROSS MOST OF THE LOWLANDS AND THE UPPER 70S FOR
THE EASTERN RIDGES. RADIATIONAL COOLING WILL BE LIMITED A BIT BY A
WEAK SOUTHEASTERLY WIND TONIGHT, SO LOWS ARE FORECAST TO BE CLOSER
TO THE WARMER MET GUIDANCE, IN THE LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A GENERAL MODEL CONSENSUS INDICATES THAT THE 500MB FLOW WILL
BECOME MORE SOUTHWESTERLY LATE THURSDAY INTO FRIDAY AS A TROUGH
DEVELOPS ACROSS THE ARKLATEX REGION. THIS WILL ALLOW FOR LOW-LEVEL
MOISTURE AND INSTABILITY TO INCREASE FROM THE SOUTHWEST ON
THURSDAY. THUS, SCHC POPS ARE FORECAST SOUTH AND WEST OF
PITTSBURGH FOR THE LATE AFTERNOON INTO THE EARLY EVENING.
DEEPER MOISTURE WILL ADVECT INTO THE AREA ON FRIDAY AS THE TROUGH
SHIFTS NORTHWARD INTO THE LOWER GREAT LAKES AND A FRONTAL BOUNDARY
PUSHES NORTHWARD ACROSS THE AREA. WITH THIS IN MIND, AN INCREASE IN
COVERAGE OF DIURNALLY DRIVEN CONVECTION IS ANTICIPATED ON FRIDAY
WITH CHC POPS ACROSS THE AREA.
TEMPS ARE CLOSEST TO MET GUIDANCE ON THURSDAY FORECAST TO BE A FEW
DEGREES ABOVE NORMAL. WITH INCREASED CLOUD COVERAGE BY FRIDAY
AFTERNOON, THIS WILL LIMIT HIGHS TO A FEW DEGREES BELOW SEASONAL
NORMALS FOR AREAS SOUTH OF PITTSBURGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOWS A WEAK UPPER
LEVEL TROUGH ACROSS THE GREAT LAKES MUCH OF THIS PERIOD WITH WEAK
SOUTHERLY WINDS AT LOW LEVELS. THIS SYNOPTIC SCENARIO WILL RESULT IN
AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY ACROSS THE UPPER
OHIO VALLEY. THERE WILL ALSO LIKELY BE A SLOW NORTHWARD MOVING WARM
FRONT AFFECTING THE UPPER OHIO VALLEY THIS PERIOD, BUT HAVE LOW
CONFIDENCE IN ITS POSITION ON ANY GIVEN DAY.
SO HAVE MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD WITH TEMPERATURES GENERALLY ABOUT 5 DEGREES WARMER THAN
NORMAL, USING BLEND OF GFS MOS AND ECMWF MODEL OUTPUT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CONDITIONS AND LIGHT WINDS THROUGH DAYTIME TODAY WITH LITTLE
MORE THAN SCATTERED AFTERNOON CUMULUS. CLEAR SKIES
CAN BE EXPECTED TONIGHT WITH CUMULUS DISSIPATING RAPIDLY AFTER
SUNSET.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RESTRICTIONS ARE POSSIBLE IN PATCHY FOG DURING EARLY MORNING EACH
DAY. STARTING LATE FRIDAY...SCATTERED THUNDERSTORMS ASSOCIATED
WITH A SLOWLY NORTHWARD MOVING WARM FRONT MAY ALSO CAUSE SOME
RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
818 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL ALLOW FOR MOSTLY
DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY THROUGH THURSDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MIDWEST AT THE END OF
THE WEEK, PUSHING A FRONTAL BOUNDARY AND DEEPER MOISTURE INTO THE
AREA WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONLY CHANGES WITH THE 815AM UPDATE WERE TO TWEAK HOURLY
TEMPERATURE TRENDS AND ADJUST CLOUD COVER. PREVIOUS DISCUSSION
FOLLOWS.
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A DRY,
ZONAL MID-LEVEL FLOW WITH A 1022MB SURFACE HIGH CENTERED ACROSS
THE GREAT LAKES. WITH THIS PATTERN IN PLACE, SKIES ARE MOSTLY CLEAR
ACROSS MOST OF THE UPPER OHIO VALLEY WITH BROKEN MID DECK CLOUDS
ADVECTING ACROSS CENTRAL OHIO.
THE FORECAST AREA WILL CONTINUES TO BE IN A ZONAL FLOW TODAY AS HIGH
PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND THE NORTHEAST.
THUS, THE FORECAST IS DRY FOR THE MAJORITY. THE ONE CAVEAT IN THE
FORECAST TODAY IS POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS AREAS SOUTHEAST OF PITTSBURGH, PARTICULARLY ACROSS
THE RIDGES. DIURNAL HEATING WITH WEAK INSTABILITY (500-1000 J/KG
SBCAPE) MAY BE ENOUGH TO DEVELOP ISOLATED LATE AFTERNOON
CONVECTION OVER THE RIDGES. TAKING THIS INTO CONSIDERATION ALONG
WITH SUPPORT FROM THE WRF-ARW AND SREF, CHC POPS ARE FORECAST
ACROSS THE SOUTHEASTERN RIDGES. ANY CONVECTION WILL QUICKLY
DIMINISH BY SUNSET WITH CLOUD COVERAGE DECREASING OVERNIGHT.
850 TEMPS WARM SLIGHTLY AND BELIEVE TREND WILL CONTINUE WITH TEMPS
WARMER THAN MAV/MET GUIDANCE. THUS, HIGHS TODAY ARE FORECAST TO WARM
INTO THE UPPER 80S ACROSS MOST OF THE LOWLANDS AND THE UPPER 70S FOR
THE EASTERN RIDGES. RADIATIONAL COOLING WILL BE LIMITED A BIT BY A
WEAK SOUTHEASTERLY WIND TONIGHT, SO LOWS ARE FORECAST TO BE CLOSER
TO THE WARMER MET GUIDANCE, IN THE LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A GENERAL MODEL CONSENSUS INDICATES THAT THE 500MB FLOW WILL
BECOME MORE SOUTHWESTERLY LATE THURSDAY INTO FRIDAY AS A TROUGH
DEVELOPS ACROSS THE ARKLATEX REGION. THIS WILL ALLOW FOR LOW-LEVEL
MOISTURE AND INSTABILITY TO INCREASE FROM THE SOUTHWEST ON
THURSDAY. THUS, SCHC POPS ARE FORECAST SOUTH AND WEST OF
PITTSBURGH FOR THE LATE AFTERNOON INTO THE EARLY EVENING.
DEEPER MOISTURE WILL ADVECT INTO THE AREA ON FRIDAY AS THE TROUGH
SHIFTS NORTHWARD INTO THE LOWER GREAT LAKES AND A FRONTAL BOUNDARY
PUSHES NORTHWARD ACROSS THE AREA. WITH THIS IN MIND, AN INCREASE IN
COVERAGE OF DIURNALLY DRIVEN CONVECTION IS ANTICIPATED ON FRIDAY
WITH CHC POPS ACROSS THE AREA.
TEMPS ARE CLOSEST TO MET GUIDANCE ON THURSDAY FORECAST TO BE A FEW
DEGREES ABOVE NORMAL. WITH INCREASED CLOUD COVERAGE BY FRIDAY
AFTERNOON, THIS WILL LIMIT HIGHS TO A FEW DEGREES BELOW SEASONAL
NORMALS FOR AREAS SOUTH OF PITTSBURGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOWS A WEAK UPPER
LEVEL TROUGH ACROSS THE GREAT LAKES MUCH OF THIS PERIOD WITH WEAK
SOUTHERLY WINDS AT LOW LEVELS. THIS SYNOPTIC SCENARIO WILL RESULT IN
AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY ACROSS THE UPPER
OHIO VALLEY. THERE WILL ALSO LIKELY BE A SLOW NORTHWARD MOVING WARM
FRONT AFFECTING THE UPPER OHIO VALLEY THIS PERIOD, BUT HAVE LOW
CONFIDENCE IN ITS POSITION ON ANY GIVEN DAY.
SO HAVE MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD WITH TEMPERATURES GENERALLY ABOUT 5 DEGREES WARMER THAN
NORMAL, USING BLEND OF GFS MOS AND ECMWF MODEL OUTPUT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CONDITIONS AND LIGHT WINDS THROUGH DAYTIME TODAY WITH LITTLE
MORE THAN SCATTERED AFTERNOON CUMULUS. CLEAR SKIES
CAN BE EXPECTED TONIGHT WITH CUMULUS DISSIPATING RAPIDLY AFTER
SUNSET.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RESTRICTIONS ARE POSSIBLE IN PATCHY FOG DURING EARLY MORNING EACH
DAY. STARTING LATE FRIDAY...SCATTERED THUNDERSTORMS ASSOCIATED
WITH A SLOWLY NORTHWARD MOVING WARM FRONT MAY ALSO CAUSE SOME
RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
540 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL ALLOW FOR MOSTLY
DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY THROUGH THURSDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MIDWEST AT THE END OF
THE WEEK, PUSHING A FRONTAL BOUNDARY AND DEEPER MOISTURE INTO THE
AREA WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A QUICK UPDATE HAS BEEN ISSUED TO ADD THE MENTION OF ISOLATED
SPRINKLES IN EAST-CENTRAL OHIO.
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A DRY,
ZONAL MID-LEVEL FLOW WITH A 1022MB SURFACE HIGH CENTERED ACROSS
THE GREAT LAKES. WITH THIS PATTERN IN PLACE, SKIES ARE MOSTLY CLEAR
ACROSS MOST OF THE UPPER OHIO VALLEY WITH BROKEN MID DECK CLOUDS
ADVECTING ACROSS CENTRAL OHIO.
THE FORECAST AREA WILL CONTINUES TO BE IN A ZONAL FLOW TODAY AS HIGH
PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND THE NORTHEAST.
THUS, THE FORECAST IS DRY FOR THE MAJORITY. THE ONE CAVEAT IN THE
FORECAST TODAY IS POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS AREAS SOUTHEAST OF PITTSBURGH, PARTICULARLY ACROSS
THE RIDGES. DIURNAL HEATING WITH WEAK INSTABILITY (500-1000 J/KG
SBCAPE) MAY BE ENOUGH TO DEVELOP ISOLATED LATE AFTERNOON
CONVECTION OVER THE RIDGES. TAKING THIS INTO CONSIDERATION ALONG
WITH SUPPORT FROM THE WRF-ARW AND SREF, CHC POPS ARE FORECAST
ACROSS THE SOUTHEASTERN RIDGES. ANY CONVECTION WILL QUICKLY
DIMINISH BY SUNSET WITH CLOUD COVERAGE DECREASING OVERNIGHT.
850 TEMPS WARM SLIGHTLY AND BELIEVE TREND WILL CONTINUE WITH TEMPS
WARMER THAN MAV/MET GUIDANCE. THUS, HIGHS TODAY ARE FORECAST TO WARM
INTO THE UPPER 80S ACROSS MOST OF THE LOWLANDS AND THE UPPER 70S FOR
THE EASTERN RIDGES. RADIATIONAL COOLING WILL BE LIMITED A BIT BY A
WEAK SOUTHEASTERLY WIND TONIGHT, SO LOWS ARE FORECAST TO BE CLOSER
TO THE WARMER MET GUIDANCE, IN THE LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A GENERAL MODEL CONSENSUS INDICATES THAT THE 500MB FLOW WILL
BECOME MORE SOUTHWESTERLY LATE THURSDAY INTO FRIDAY AS A TROUGH
DEVELOPS ACROSS THE ARKLATEX REGION. THIS WILL ALLOW FOR LOW-LEVEL
MOISTURE AND INSTABILITY TO INCREASE FROM THE SOUTHWEST ON
THURSDAY. THUS, SCHC POPS ARE FORECAST SOUTH AND WEST OF
PITTSBURGH FOR THE LATE AFTERNOON INTO THE EARLY EVENING.
DEEPER MOISTURE WILL ADVECT INTO THE AREA ON FRIDAY AS THE TROUGH
SHIFTS NORTHWARD INTO THE LOWER GREAT LAKES AND A FRONTAL BOUNDARY
PUSHES NORTHWARD ACROSS THE AREA. WITH THIS IN MIND, AN INCREASE IN
COVERAGE OF DIURNALLY DRIVEN CONVECTION IS ANTICIPATED ON FRIDAY
WITH CHC POPS ACROSS THE AREA.
TEMPS ARE CLOSEST TO MET GUIDANCE ON THURSDAY FORECAST TO BE A FEW
DEGREES ABOVE NORMAL. WITH INCREASED CLOUD COVERAGE BY FRIDAY
AFTERNOON, THIS WILL LIMIT HIGHS TO A FEW DEGREES BELOW SEASONAL
NORMALS FOR AREAS SOUTH OF PITTSBURGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOWS A WEAK UPPER
LEVEL TROUGH ACROSS THE GREAT LAKES MUCH OF THIS PERIOD WITH WEAK
SOUTHERLY WINDS AT LOW LEVELS. THIS SYNOPTIC SCENARIO WILL RESULT IN
AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY ACROSS THE UPPER
OHIO VALLEY. THERE WILL ALSO LIKELY BE A SLOW NORTHWARD MOVING WARM
FRONT AFFECTING THE UPPER OHIO VALLEY THIS PERIOD, BUT HAVE LOW
CONFIDENCE IN ITS POSITION ON ANY GIVEN DAY.
SO HAVE MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD WITH TEMPERATURES GENERALLY ABOUT 5 DEGREES WARMER THAN
NORMAL, USING BLEND OF GFS MOS AND ECMWF MODEL OUTPUT.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CONDITIONS AND LIGHT WINDS THROUGH DAYTIME TODAY WITH LITTLE
MORE THAN SCATTERED AFTERNOON CUMULUS. CLEAR SKIES
CAN BE EXPECTED TONIGHT WITH CUMULUS DISSIPATING RAPIDLY AFTER
SUNSET.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RESTRICTIONS ARE POSSIBLE IN PATCHY FOG DURING EARLY MORNING EACH
DAY. STARTING LATE FRIDAY...SCATTERED THUNDERSTORMS ASSOCIATED
WITH A SLOWLY NORTHWARD MOVING WARM FRONT MAY ALSO CAUSE SOME
RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
354 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL ALLOW FOR MOSTLY
DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY THROUGH THURSDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MIDWEST AT THE END OF
THE WEEK, PUSHING A FRONTAL BOUNDARY AND DEEPER MOISTURE INTO THE
AREA WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A DRY,
ZONAL MID-LEVEL FLOW WITH A 1022MB SURFACE HIGH CENTERED ACROSS
THE GREAT LAKES. WITH THIS PATTERN IN PLACE, SKIES ARE CLEAR
ACROSS MOST OF THE UPPER OHIO VALLEY WITH MID-LEVEL CLOUDS
ADVECTING ACROSS THE SOUTHEASTERN RIDGES.
THE FORECAST AREA WILL CONTINUES TO BE IN A ZONAL FLOW TODAY AS HIGH
PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND THE NORTHEAST.
THUS, THE FORECAST IS DRY FOR THE MAJORITY. THE ONE CAVEAT IN THE
FORECAST TODAY IS POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS AREAS SOUTHEAST OF PITTSBURGH, PARTICULARLY ACROSS
THE RIDGES. DIURNAL HEATING WITH WEAK INSTABILITY (500-1000 J/KG
SBCAPE) MAY BE ENOUGH TO DEVELOP ISOLATED LATE AFTERNOON
CONVECTION OVER THE RIDGES. TAKING THIS INTO CONSIDERATION ALONG
WITH SUPPORT FROM THE WRF-ARW AND SREF, CHC POPS ARE FORECAST
ACROSS THE SOUTHEASTERN RIDGES. ANY CONVECTION WILL QUICKLY
DIMINISH BY SUNSET WITH CLOUD COVERAGE DECREASING OVERNIGHT.
850 TEMPS WARM SLIGHTLY AND BELIEVE TREND WILL CONTINUE WITH TEMPS
WARMER THAN MAV/MET GUIDANCE. THUS, HIGHS TODAY ARE FORECAST TO WARM
INTO THE UPPER 80S ACROSS MOST OF THE LOWLANDS AND THE UPPER 70S FOR
THE EASTERN RIDGES. RADIATIONAL COOLING WILL BE LIMITED A BIT BY A
WEAK SOUTHEASTERLY WIND TONIGHT, SO LOWS ARE FORECAST TO BE CLOSER
TO THE WARMER MET GUIDANCE, IN THE LOWER 60S.
&&
SHORT TERM /THURSDAY THROUGH FRIDAY/...
A GENERAL MODEL CONSENSUS INDICATES THAT THE 500MB FLOW WILL
BECOME MORE SOUTHWESTERLY LATE THURSDAY INTO FRIDAY AS A TROUGH
DEVELOPS ACROSS THE ARKLATEX REGION. THIS WILL ALLOW FOR LOW-LEVEL
MOISTURE AND INSTABILITY TO INCREASE FROM THE SOUTHWEST ON
THURSDAY. THUS, SCHC POPS ARE FORECAST SOUTH AND WEST OF
PITTSBURGH FOR THE LATE AFTERNOON INTO THE EARLY EVENING.
DEEPER MOISTURE WILL ADVECT INTO THE AREA ON FRIDAY AS THE TROUGH
SHIFTS NORTHWARD INTO THE LOWER GREAT LAKES AND A FRONTAL BOUNDARY
PUSHES NORTHWARD ACROSS THE AREA. WITH THIS IN MIND, AN INCREASE IN
COVERAGE OF DIURNALLY DRIVEN CONVECTION IS ANTICIPATED ON FRIDAY
WITH CHC POPS ACROSS THE AREA.
TEMPS ARE CLOSEST TO MET GUIDANCE ON THURSDAY FORECAST TO BE A FEW
DEGREES ABOVE NORMAL. WITH INCREASED CLOUD COVERAGE BY FRIDAY
AFTERNOON, THIS WILL LIMIT HIGHS TO A FEW DEGREES BELOW SEASONAL
NORMALS FOR AREAS SOUTH OF PITTSBURGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOWS A WEAK UPPER
LEVEL TROUGH ACROSS THE GREAT LAKES MUCH OF THIS PERIOD WITH WEAK
SOUTHERLY WINDS AT LOW LEVELS. THIS SYNOPTIC SCENARIO WILL RESULT IN
AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY ACROSS THE UPPER
OHIO VALLEY. THERE WILL ALSO LIKELY BE A SLOW NORTHWARD MOVING WARM
FRONT AFFECTING THE UPPER OHIO VALLEY THIS PERIOD, BUT HAVE LOW
CONFIDENCE IN ITS POSITION ON ANY GIVEN DAY.
SO HAVE MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD WITH TEMPERATURES GENERALLY ABOUT 5 DEGREES WARMER THAN
NORMAL, USING BLEND OF GFS MOS AND ECMWF MODEL OUTPUT.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CONDITIONS AND LIGHT WINDS THROUGH DAYTIME TODAY WITH LITTLE
MORE THAN SCATTERED AFTERNOON CUMULUS. CLEAR SKIES
CAN BE EXPECTED TONIGHT WITH CUMULUS DISSIPATING RAPIDLY AFTER
SUNSET.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RESTRICTIONS ARE POSSIBLE IN PATCHY FOG DURING EARLY MORNING EACH
DAY. STARTING LATE FRIDAY...SCATTERED THUNDERSTORMS ASSOCIATED
WITH A SLOWLY NORTHWARD MOVING WARM FRONT MAY ALSO CAUSE SOME
RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
210 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL ALLOW FOR MOSTLY
DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY THROUGH THURSDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE MIDWEST AT THE END OF
THE WEEK, PUSHING A FRONTAL BOUNDARY AND DEEPER MOISTURE INTO THE
AREA WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A DRY,
ZONAL MID-LEVEL FLOW WITH A 1022MB SURFACE HIGH CENTERED ACROSS
THE GREAT LAKES. WITH THIS PATTERN IN PLACE, SKIES ARE CLEAR
ACROSS MOST OF THE UPPER OHIO VALLEY WITH MID-LEVEL CLOUDS
ADVECTING ACROSS THE SOUTHEASTERN RIDGES.
THE FORECAST AREA WILL REMAIN IN A ZONAL FLOW TODAY AS HIGH PRESSURE
REMAINS PARKED ACROSS THE GREAT LAKES AND THE NORTHEAST. THUS, THE
FORECAST IS DRY FOR THE MAJORITY. THE ONE CAVEAT IN THE FORECAST
TODAY IS POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TO DEVELOP
ACROSS AREAS SOUTHEAST OF PITTSBURGH, PARTICULARLY ACROSS THE
RIDGES. DIURNAL HEATING WITH WEAK INSTABILITY (500-1000 J/KG SBCAPE)
MAY BE ENOUGH TO DEVELOP ISOLATED LATE AFTERNOON CONVECTION OVER THE
RIDGES. TAKING THIS INTO CONSIDERATION ALONG WITH SUPPORT FROM THE
WRF-ARW AND SREF, CHC POPS ARE FORECAST ACROSS THE SOUTHEASTERN
RIDGES. ANY CONVECTION WILL QUICKLY DIMINISH BY SUNSET WITH CLOUD
COVERAGE DECREASING OVERNIGHT.
850 TEMPS WARM SLIGHTLY AND BELIEVE TREND WILL CONTINUE WITH TEMPS
WARMER THAN MAV/MET GUIDANCE. THUS, HIGHS TODAY ARE FORECAST TO WARM
INTO THE UPPER 80S ACROSS MOST OF THE LOWLANDS AND THE UPPER 70S FOR
THE EASTERN RIDGES. RADIATIONAL COOLING WILL BE LIMITED A BIT BY A
WEAK SOUTHEASTERLY WIND TONIGHT, SO LOWS ARE FORECAST TO BE CLOSER
TO THE WARMER MET GUIDANCE, IN THE LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
GEFS AND SREF REMAIN SLIGHTLY MORE AGGRESSIVE ABOUT BRINGING
PRECIPITATION INTO THE SOUTHERN TIER COUNTIES ON THURSDAY...WITH
DETERMINISTIC MODELS SHUNTING PRECIPITATION INTO INDIANA AND
WESTERN OHIO. WILL KEEP FORECAST DRY FOR THURSDAY...AND BRING JUST
SOME SLIGHT CHANCE POPS TOWARDS INTERSTATE 70 THURSDAY NIGHT.
CANNOT IGNORE THE CHANCE POPS SHOWN EVERYWHERE BY THE ENSEMBLES ON
FRIDAY...AND HAVE THOSE POPS INCLUDED IN THE FORECAST...WITH
HIGHER VALUES ACROSS EASTERN OHIO WHERE THE DETERMINISTIC MODELS
ALSO SHOW PRECIPITATION. THURSDAY COULD BE ANOTHER DEGREE OR TWO
WARMER THAN WEDNESDAY...BUT TEMPERATURES SHOULD COOL BACK TO
AROUND 80 WITH MOSTLY CLOUDY SKIES ON FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT SHOWS A WEAK UPPER
LEVEL TROUGH ACROSS THE GREAT LAKES MUCH OF THIS PERIOD WITH WEAK
SOUTHERLY WINDS AT LOW LEVELS. THIS SYNOPTIC SCENARIO WILL RESULT IN
AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY ACROSS THE UPPER
OHIO VALLEY. THERE WILL ALSO LIKELY BE A SLOW NORTHWARD MOVING WARM
FRONT AFFECTING THE UPPER OHIO VALLEY THIS PERIOD, BUT HAVE LOW
CONFIDENCE IN ITS POSITION ON ANY GIVEN DAY.
SO HAVE MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD WITH TEMPERATURES GENERALLY ABOUT 5 DEGREES WARMER THAN
NORMAL, USING BLEND OF GFS MOS AND ECMWF MODEL OUTPUT.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CONDITIONS AND LIGHT WINDS THROUGH DAYTIME TODAY WITH LITTLE
MORE THAN SCATTERED AFTERNOON CUMULUS. CLEAR SKIES
CAN BE EXPECTED TONIGHT WITH CUMULUS DISSIPATING RAPIDLY AFTER
SUNSET.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RESTRICTIONS ARE POSSIBLE IN PATCHY FOG DURING EARLY MORNING EACH
DAY. STARTING LATE FRIDAY...SCATTERED THUNDERSTORMS ASSOCIATED
WITH A SLOWLY NORTHWARD MOVING WARM FRONT MAY ALSO CAUSE SOME
RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
716 PM CDT THU JUL 12 2012
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
TONIGHT AND FRIDAY...TRANSITIONING FLOW ALOFT ALONG WITH AN
INCOMING FRONTAL SYSTEM WILL MAKE FOR A BIT OF A MESSY FCST OVER
THE NEXT 12-24 HOURS. LARGE UPPER RIDGE CENTERED OVER THE
4-CORNERS REGION WILL RETROGRADE BACK TO THE SW...WANING ITS
INFLUENCE OVER THE REGION TONIGHT. MEANWHILE...AS THE RIDGE BACKS
OFF...A COMPACT UPPER LEVEL LOW WILL DROP IN FROM MANITOBA AND
HELP NUDGE ALONG THE FRONTAL SYSTEM. AN INCREASE IN MID- AND
UPPER-LEVEL MOISTURE BEING DRAGGED IN FROM THE PACIFIC ALONG WITH
MUCAPES INCRG TO THE 1500-2000 J/KG RANGE MAY BE CAPABLE OF
PRODUCING ISOLD STRONG TO SEVERE TSTMS TNGT THRU TMRW. HOWEVER...
POOR LAPSE RATES SHOULD MITIGATE ANY SUBSTANTIAL COVERAGE. HAVE
CAPPED POPS IN THE CHC RANGE SINCE THIS WILL NOT BE ANY KIND OF
WASHOUT BUT RATHER SHORT-DURATION PRECIP OF THE HIT-AND-MISS
VARIETY. POPS INCRS TNGT WITH HIGHEST POPS DURG THE DAY ON FRIDAY.
HAVE ALSO KEPT THE HIGHEST QPF OVER NRN PORTIONS OF THE AREA...BUT
THAT SAID...AM NOT LOOKING FOR SITES TO RECEIVE MORE THAN 0.25
INCHES OF RAIN. TEMPS WILL CONTINUE THEIR WARMING TREND THRU THE
NEXT 24 HRS AS LOW LEVEL SOUTHERLY FLOW TAKES HOLD OVER THE
REGION. WARM SECTORING WILL PLAY A PART AS THE COLD FRONT SLOGS
ITS WAY INTO WESTERN AND CENTRAL MN...ALTHOUGH TEMPERED A BIT BY
SCATTERED SHWRS/TSTMS. HIGHS WILL REACH THE UPPER 80S TO ARND 90.
FRIDAY NIGHT THROUGH SUNDAY...ELEVATED INSTABILITY WILL REMAIN IN
PLACE THRU SATURDAY AHEAD OF THE CDFNT WHILE MODEST UPPER FORCING
ALSO SLOWLY PROGRESSES THRU THE REGION. LAPSE RATES STILL ARE NOT
OVERLY IMPRESSIVE...BUT RELATIVELY WEAK CAPPING SHOULD PROMOTE
SHWR/TSTM ACTIVITY ONGOING FRI EVENING THAT WILL CONTINUE SLOWLY
SHIFT E THRU THE DAY SAT INTO SAT EVE. AGAIN...CAPPED POPS IN THE
CHC RANGE DUE TO LARGE UNCERTAINTY WITH THE COVERAGE/LOCATION OF
CONVECTIVE ACTIVITY. IT MAY AGAIN WELL BE THAT LOCATIONS THAT
RECEIVED RAINFALL FRIDAY MAY SEE IT AGAIN ON SATURDAY WHILE SOME
SPOTS SEE PRECIP ON NEITHER DAY...AGAIN THE HIT-AND-MISS VARIETY.
THE CDFNT WILL PUSH INTO ERN MN AND WRN WI SAT EVE THEN EXIT THE
REGION SAT NIGHT INTO SUN...RESULTING IN A DRY DAY ON SUN. STILL
THE POSSIBILITY IS THERE FOR ISOLD STRONG TO SEVERE TSTMS FRI EVE
BUT AS THE FORCING SHIFTS E...THE THREAT WILL DIMINISH FRI NIGHT
INTO SAT. EVEN WITH THE COLD FROPA...THERE WILL NOT BE A DROP IN
TEMPS BEHIND AS A WARM DOME OF HIGH PRESSURE OVER THE 4-CORNERS
REGION LOOKS TO RE-EXTEND ITSELF INTO THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY. BY SUNDAY...HIGHS WILL REACH THE
LOWER 90S FOR MUCH OF THE WFO MPX CWFA.
MONDAY THROUGH WEDNESDAY...STRONG WARMING WILL CONTINUE INTO
MONDAY AS THE UPPER LEVEL RIDGE AXIS SHIFTS ACRS THE REGION...
RESULTING IN STRONG CAPPING DESPITE INCREASED HUMIDITY AND
TEMPERATURES. MAY SEE SOME ISOLD ACTIVITY OVER NRN PORTIONS OF THE
AREA MONDAY...BUT THE MAIN STORY WILL BE THE HEAT. HIGHS WILL
REACH THE MIDDLE TO POSSIBLY UPPER 90S WHILE DEWPOINTS INCREASE TO
ARND 70. THIS WILL NUDGE HEAT INDEX VALUES INTO THE 100-105
DEGREES RANGE...SO THIS WITH LOWS IN THE LOW TO MID 70S SUN NIGHT
AND MON NIGHT MAY CREATE HEAT ADVISORY CONDITIONS. AS THE BUBBLE
HIGH SHIFTS E...THE HEAT WILL THEN TRANSITION INTO CENTRAL WI TUE
THEN LOSE ITS INFLUENCE BY WED AS NORTHERLY SFC WINDS WITH NW
UPPER FLOW BRINGS A SLIGHT COOLDOWN TO THE AREA. AS FOR PRECIP...
NOT A WHOLE LOT TO SPEAK UP DURING THE FIRST HALF OF THE WEEK AS
SIDE FROM A FEW WEAK UPPER LEVEL DISTURBANCES GLIDING THROUGH NRN
MN WHICH MAY EXTEND ENOUGH S INTO CENTRAL MN TO SPARK OFF ISOLD
CONVECTION. CAPPED POPS AT 20 PERCENT...WITH MANY LOCATIONS NOT
EVEN HAVING ANYTHING MENTIONABLE THROUGH THE PERIOD.
&&
.AVIATION.../00Z TAF ISSUANCE/
NICE UPPER LOW NEAR GRAND FORKS AT 00Z WILL SLOWLY TRANSITION OVER
TO AROUND DULUTH BY THE END OF THE TAF PERIOD. RATHER DIFFUSE SFC
BOUNDARY ACROSS THE DAKOTAS HAS COMBINED WITH MODEST INSTABILITY
AND LITTLE CAPPING TO GENERATE SCT STORMS FROM NW MN ALL THE WAY
DOWN TO NE NEB. THIS THEME OF WEAK UPPER FORCING AND A RATHER
DIFFUSE SFC BOUNDARY WILL CONTINUE WELL PAST THIS TAF
PERIOD...RESULTING IN A VERY LOW CONFIDENCE PRECIP FORECAST. GIVEN
LOW CONFIDENCE...STUCK WITH NOTHING MORE THAN A VC MENTION FOR
PRECIP WITH THESE TAFS. BASED VC MENTION TONIGHT ON FORECAST
MOVEMENT OF THE TROUGH AT 850 MB ALONG WITH THE HRRR REFLECTIVITY
FORECAST...WHICH CLOSELY MIRRORS THIS LOW LEVEL FORCING.
AGAIN...NOT ALL THAT EXCITED ABOUT COVERAGE WITH THIS ACTIVITY AT
THE MOMENT. FOR THE AFTERNOON...THE QUESTION BECOMES HOW FAR EAST
DOES THE SFC BOUNDARY MAKE IT. AT THE MOMENT...LOOKING LIKE IT
WILL BE IN THE NEIGHBORHOOD OF MSP BY THE AFTERNOON...WITH BEST
PRECIP CHANCES POSSIBLY RESIDING EAST OF MSP ACROSS WI...WHERE THE
VCTS MENTION WAS INTRODUCED. BAND OF MID LEVEL FORCING AND
ASSOCIATED CLOUDS MAY THROW OFF A SPIT OF RAIN OR TWO THIS
EVENING...BUT REPORTS HAVE BEEN FEW AND FAR BETWEEN...SO EXPECT
THIS TO CONTINUE TO REMAIN AS VIRGA. FOR WINDS...GRADIENT WILL BE
GETTING BAGGIER THROUGH THE NIGHT...WITH WEAKER WINDS EXPECTED
THIS TAF PERIOD AS A RESULT. ONLY EXCEPTION WOULD BE AT AXN IN THE
AFTERNOON...WHICH COULD SEE SOME GUSTINESS TO THE NW WIND BEHIND
THE FRONT.
KMSP...TRICKY FORECAST THIS PERIOD...WITH IT HARD TO SAY WHEN THERE
WILL BE NO CHANCE FOR RAIN BEGINNING AROUND 9Z TONIGHT AND LASTING
THROUGH THE REST OF THE TAF PERIOD. NOT WANTING NEARLY 20 HOURS OF
VCSH...LIMITED THE VC MENTION TO LATER TONIGHT...WHEN BETTER LLJ
FORCING MOVES IN AND THE RAP/HRRR/ECMWF WANT TO SHOW SOME PRECIP
MOVING THROUGH. WILL LIKELY HAVE TSRA AROUND AGAIN FRIDAY
AFTERNOON...BUT HARD TO SAY WHERE/WHEN THEY WILL BE...SO RATHER
THAN GO WITH A LONG PERIOD OF VCSH FROM 14.19Z TO 15.06Z...WENT
WITH THE LOWER CIG ROUTE FOR NOW. IS LOOKING LIKE THE BEST FORCING
WILL BE JUST EAST OF MSP FOR THE AFTERNOON. AGAIN...CAN NOT RULE
OUT TSRA FRI AFTERNOON...BUT GIVEN CURRENT CONFIDENCE...LEFT THE
VC MENTION OUT.
/OUTLOOK/
SATURDAY...VFR WITH SHRA ENDING IN THE MORNING. WINDS NW AT 5 TO 10KTS.
SUNDAY...VFR. WINDS SE AT 5-10 KTS.
MONDAY...VFR. WINDS S-SW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
254 PM CDT WED JUL 11 2012
.SYNOPSIS...WATER VAPOR IMAGERY INDICATES TWO SIGNIFICANT SHORT
WAVES MOVING AROUND THE WESTERN STATES UPPER RIDGE. THE FIRST IS
PUSHING INTO WRN ND AND THE SECOND MOVING INTO SWRN MT PER WV
IMAGERY AND RAP PVU FIELDS. AHEAD OF THESE FEATURES SCT
THUNDERSTORMS HAVE DEVELOPED IN THE HIGHER TERRAIN AND ARE PUSHING
EWD. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA SKIES ARE MAINLY
CLEAR EXCEPT FOR CUMULUS FIELD DEVELOPING FROM MCK TO VTN. NORTH
CENTRAL NEBRASKA LIES IN SFC THERMAL RIDGE AHEAD OF ADVANCING COLD
FRONT PUSHING INTO THE NORTHERN HIGH PLAINS.
&&
.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT). UPPER FEATURE
MOVING INTO SOUTHWEST MT WILL CONTINUE TO PUSH SEWD TONIGHT INTO
THURSDAY. MODELS SIMILAR IN PROGRESSION OF THIS FEATURE BUT DIFFER
IN THE HANDLING OF ASSOCIATED UPPER PV FEATURES AND RESULTING
CONVECTION AS THE SFC REFLECTION /COLD FRONT/ MOVES INTO NORTHWEST
NEBRASKA. GFS KEEPS A STRONGER UPPER PV MAX AND HENCE BETTER LARGE
SCALE FORCING FOR ASCENT ACROSS THE DAKOTAS...WHILE THE NAM HAS AN
UPPER PV MAX MOVING INTO NWRN NEBRASKA WHICH SERVES TO PROMOTE
BETTER CONVERGENCE ALONG THE FRONT IN WESTERN NEBRASKA THROUGH THE
DAY THURSDAY. WILL SIDE WITH THE NAM SOLUTION BELIEVING THE GFS
IDEA IS AT LEAST PARTIAL DRIVEN BY CONVECTIVE FEEDBACK. THIS WOULD
YIELD CHC POPS ALONG AND IN THE VCNTY OF THE FRONT AS THE FRONT
SLIDES SLOWLY SOUTH ACROSS NEBRASKA. FRONT WILL BE MEETING
RESISTENCE AS IT ENCOUNTERS DIURNAL PLAINS LLJ THRU THURS MORNING
AND PRE-EXISTING HEAT ACROSS THE CENTRAL PLAINS. TEMPERATURES
AHEAD OF THE FRONT SHOULD WARM QUICKLY THURSDAY WITH PLENTY OF
SUNSHINE....SO LOW TO MID 90S IN THE SOUTH STILL LOOKS PLAUSIBLE.
CONVECTION SHOULD BE LIMITED PRIMARILY TO THE FORCING ALONG THE
FRONT BUT AS LOW LEVEL MOISTURE POOLS AHEAD OF IT THE INSTABILITY
SHOULD INCREASE THROUGH THE AFTERNOON. HOWEVER...FCST SOUNDINGS
SUGGEST CAPE DISTRIBUTION IS IN A NARROW CORRIDOR VERTICALLY SO
WITH MARGINAL DEEP LAYER SHEAR WOULD EXPECT UPDRAFTS WILL BE PULSE
TYPE EXCEPT WHERE ORGANIZATION CAN BE SUSTAINED...SUCH AS CLOSE TO
THE FRONT AND WHERE STORM-SCALE INTERACTIONS DICTATE. RESULT
SHOULD BE LIMTED LARGE HAIL THREAT BUT SOME POTENTIAL FOR NEAR SVR
WIND GUSTS.
.EXTENDED...FRIDAY THROUGH NEXT WEDNESDAY...
ON FRIDAY...AN UPPER LEVEL WAVE WILL BE EXITING THE REGION WITH
NORTHWEST FLOW ALOFT EXPECTED ACROSS THE REGION IN ITS WAKE. A WEAK
COLD FRONT WILL PUSH INTO NEBRASKA FROM THE NORTH ON FRIDAY
MORNING...BUT HAVE A HARD TIME MAKING IT TOO FAR INTO THE STATE.
BEHIND THE DEPARTING UPPER WAVE...AN UPPER LEVEL RIDGE WILL BUILD IN
OVER THE CENTRAL U.S. ALLOWING ABOVE AVERAGE TEMPERATURES TO
CONTINUE ACROSS THE AREA FOR SATURDAY. THE UPPER LEVEL RIDGE AXIS
WILL DRIFT EAST OVER THE WEEKEND...WITH AN UPPER LEVEL DISTURBANCE
FOLLOWING RIGHT BEHIND IT IN SOUTHWEST FLOW ALOFT. THE ECMWF AND GFS
MODELS ARE IN GOOD AGREEMENT REGARDING THIS WAVE...WHICH MAY PROVIDE
SOME PRECIPITATION CHANCES ACROSS THE NORTHWEST FORECAST AREA
SATURDAY NIGHT. HAVE NUDGED TEMPERATURES UP FOR FRIDAY AND
SATURDAY...CLOSER TO THE WARMER ECMWF/GEM/FIM MODELS...AND MANY OF
THE BIAS CORRECTED GRID VALUES.
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE AVERAGE FOR THE BEGINNING
OF NEXT WEEK AS SOUTHWEST FLOW ALOFT WILL KEEP WARM SOUTHERLY FLOW
IN THE LOW LEVELS. MODELS HINT AT AN UPPER WAVE MOVING EAST ACROSS
THE CANADIAN BORDER TOWARD MID WEEK...POSSIBLY USHERING IN A COLD
FRONT ACROSS THE NORTHERN PLAINS STATES.
&&
.AVIATION...18Z TAF FOR KLBF AND KVTN.
VFR CIGS/VSBY THROUGH THE PERIOD. WILL LIKELY SEE SOME HIGH BASED
CU THIS AFTERNOON ESPECIALLY ACROSS NORTH CENTRAL NEBRASKA FROM
KVTN-KLBF BUT SHOULDNT GET BEYOND SCT. OTHERWISE COLD FRONT WILL
APPROACH THE AREA LATE IN THE PERIOD BUT PASSAGE EXPECTED AFTER
18Z...WHEN ISOLD TO SCT TSRA WOULD BE POSSIBLE NEAR KVTN...BUT
AGAIN AFTER 12/18Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...JWS
EXTENDED...KNUTSVIG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
211 PM EDT WED JUL 11 2012
.SYNOPSIS...
OTHER THAN AN ISOLATED SHOWER OR THUNDERSTORM THIS AFTERNOON,
PRIMARILY OVER NORTHEAST PENNSYLVANIA, PARTLY TO MOSTLY SUNNY
SKIES ARE EXPECTED THROUGH LATE WEEK. TEMPERATURES WILL GRADUALLY
WARM AS THE WEEK PROGRESSES. THE NEXT CHANCE FOR RAIN WILL COME ON
THE WEEKEND, AS HIGH PRESSURE OFF THE EAST COAST, BRINGS A WARM AND
HUMID SOUTHERLY FLOW INTO THE REGION.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATED AT 1 PM... ISOLATED SHOWERS ARE DEVELOPING ON SCHEDULE
OVER THE HIGHER TERRAIN OF THE POCONOS... AS A WEAK MID-LEVEL
SHORT WAVE MOVES ACROSS THE AREA. LATEST AREA RUC SOUNDINGS ARE
SHOWING CAPE VALUES FROM 400 TO 800 J/KG BUT WITH LOTS OF DRY AIR
THIS AFTERNOON. HI RESOLUTION MODELS ALSO SHOWING SCT-ISOLATED
SHOWERS DEVELOPING OVER NE PA THIS AFTERNOON. CURRENT FORECAST
SEEMS TO HAVE THIS HANDLED VERY WELL WITH ISOLATED POPS FOR
NORTHEAST PA. WILL TWEAK POPS UP IN THE LOCALIZED AREA WHERE
SHOWERS ARE DEVELOPING ATTM... OTHERWISE NO CHANGES TO THE ONGOING
FORECAST. PREVIOUS DISCUSSION BELOW.
UPDATED AT 10 AM... CURRENT FORECAST IN GOOD SHAPE. LATEST 12Z BUF
AND PIT SOUNDINGS SHOWING LOTS OF DRY AIR THROUGH A DEEP LAYER
ALONG WITH SOME CAPPING. FULL MIXING OF THESE SOUNDINGS WOULD
ALLOW FOR TEMPERATURES TO REACH MOSTLY THE MID 80S THIS AFTERNOON.
WATER VAPOR AND BLENDED TPW PRODUCTS SHOWING A LITTLE MORE
MOISTURE OVER EASTERN PA. SHORT WAVE CURRENTLY DIGGING SOUTHEAST
ACROSS NY COULD STILL INTERACT WITH THIS MOISTURE TO PRODUCE A FEW
ISOLATED SHOWERS MAINLY OVER THE SOUTHEAST HALF OF THE FORECAST
AREA THIS AFTERNOON. BASED ON THIS HAVE KEPT POPS IN THE 15 TO 20 PCT
RANGE ACROSS NORTHEAST PA... AND LOWER TO THE NORTH AND WEST.
PREVIOUS DISCUSSION BELOW.
640 AM UPDATE...CURRENT FORECAST IN GOOD SHAPE JUST MINOR SHORT
TERM TEMP/DEW POINT ADJUSTMENTS.
PREVIOUS DISC...
AT 415 AM...SATELLITE SHOWED CLEAR SKIES ACROSS THE REGION WITH A
BIT MORE CLOUD ACROSS THE WYOMING VALLEY AND POCONOS.
SFC HIGH PRES WILL RESIDE OVER THE REGION TODAY AS A BROAD UPPER
LEVEL TROF REMAINS OVER THE NORTHEAST. THIS AFTERNOON WITH
DAYTIME HEATING MODELS INDICATE THE BEST INSTABILITY 700-1200 J/KG
WILL RESIDE ACROSS NORTHEAST PA, THE SOUTHERN CATSKILLS AND ALONG
THE NY/PA BORDER. ONCE AGAIN MODEL SOUNDINGS INDICATE A MID LEVEL
CAP SO ACTIVITY WILL BE CONFINED TO THE AFTERNOON AND EARLY
EVENING HOURS. NOT MUCH OF A TRIGGER TODAY BUT HIGHER DEW POINTS
IN THIS REGION ALONG WITH DAYTIME HEATING SHOULD RESULT IN
ISOLATED CONVECTIVE ACTIVITY.
UNDER MOSTLY SUNNY SKIES MAX TEMPS WILL RANGE IN THE LOWER TO
MIDDLE 80S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT AND FRIDAY...GFS...EURO..CMC AND NAM ALL
INDICATE THAT A SURFACE HIGH WILL SHIFT OFF THE EAST COAST AND
FAIRLY FLAT UPPER LEVEL RIDGING WILL DEVELOP OVERHEAD BY FRI PM.
THIS WILL OPEN THE GATES TO A SWRLY LOW-LEVEL FLOW OF INCREASING
LOW-LEVEL MOISTURE AND HUMIDITY UP THE APPALACHIANS BEGINNING THU
NGT BUT LASTING THRU FRIDAY INTO SATURDAY. THIS INCREASE IN LOW-
LEVEL MOISTURE WILL LEAD TO MORE AND MORE DESTABILIZATION WITH DIURNAL
HEATING EACH DAY. MODELS VARY QUITE A BIT ON VARIOUS SCENARIOS
THIS FAR IN ADVANCE. THE NAM AND EURO SUGGESTS FRIDAY REMAINS
MOSTLY DRY WITH THE GFS AND CMC BRINGING MORE IN THE WAY OF SCT
SHRA AND TSRA FRI PM. THEN ON SATURDAY...GFS LOOKS TO BE A LITTLE
OVERDONE WITH WIDESPREAD CONVECTIVE ACVTY OVR NY AND PA WITH THE
CMC AND NAM LESS SO. THE EURO DOES NOT HAVE ANY CONVECTIVE
PRECIPITATION REACHING ANY OF OUR CWA EVEN ON SAT.
SO WHAT TO DO...I DECIDED TO GO WITH A BLEND OF THE MODEL
SOLUTIONS AND COLLABORATE WITH NEIGHBORING OFFICES WITH GRADUALLY
INCREASING POPS FROM FRI INTO SAT. POPS PEAK IN THE 30S ON
SATURDAY. TEMPERATURES WILL CONTINUES TO SLOWLY CLIMB THRU THE
PERIOD TO ABOVE SEASONAL NORMALS. I SEE NO SIGNIFICANT SEVERE
WEATHER OR FLOOD EVENTS THRU THIS PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
IN THE LONG RANGE I USED HPC AND BLENDED MY GRIDS WITH SURROUNDING
OFFICES. MORE TWEEKS WILL COME BEFORE WE SEND THEM TO THE NDFD
SERVER AS NEIGHBORING OFFICES FINISH THEIR LONG TERM GRIDS. FOR
THE WEEKEND...THE SWRLY MOIST LL FLOW CONTINUES ON THE EURO...CMC
AND GFS WITH A FLAT RIDGE ALOFT. BELIEVE SCTRD SHRA AND
THUNDERSTORMS WILL BREAK OUT AGAIN SUN PM...AFTER A WANING PERIOD
SAT NGT. FOR MONDAY MODELS INDICATE THAT SOME SORT OF SHRT WAVE
TROF PUSHES EAST INTO NY AND PA WITH MORE CHC/S FOR SHRA AND TSRA.
THIS TROF WILL PUSH A FRNT THRU THE REGION WHICH WILL EVENUALLY
CLEAR THE REGION LATER ON TUESDAY. HENCE MORE POPS AGAIN FOR
TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
EXCEPT FOR SCATTERED THUNDERSTORMS SOUTHEAST OF AVP OVER THE
POCONOS... CONDITIONS WILL BE VFR THROUGH THIS EVENING WITH SCT
CLOUDS FROM 5 TO 8 KFT. SOME FOG WILL FORM IN THE RIVER VALLEYS
LATE TONIGHT THROUGH ABOUT 13Z... WITH CONDITIONS AT ELM LIKELY
FALLING TO IFR VSBYS AT TMIES... OTHERWISE GENERALLY VFR
CONDITIONS WILL CONTINUE THROUGH THURSDAY MORNING. WINDS WILL BE
VARIABLE LESS THAN 10 KTS THROUGH THURSDAY MORNING.
OUTLOOK...
THU AFTERNOON THROUGH FRI...MOSTLY VFR.
SAT AND SUN...GENERALLY VFR. CHC MVFR SHWRS/TSTMS SAT
AFTN/EVE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MSE/RRM
SHORT TERM...DJN
LONG TERM...DJN
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
109 PM EDT WED JUL 11 2012
.SYNOPSIS...
OTHER THAN AN ISOLATED SHOWER OR THUNDERSTORM THIS AFTERNOON,
PRIMARILY OVER NORTHEAST PENNSYLVANIA, PARTLY TO MOSTLY SUNNY
SKIES ARE EXPECTED THROUGH LATE WEEK. TEMPERATURES WILL GRADUALLY
WARM AS THE WEEK PROGRESSES. THE NEXT CHANCE FOR RAIN WILL COME ON
THE WEEKEND, AS HIGH PRESSURE OFF THE EAST COAST, BRINGS A WARM AND
HUMID SOUTHERLY FLOW INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1 PM... ISOLATED SHOWERS ARE DEVELOPING ON SCHEDULE
OVER THE HIGHER TERRAIN OF THE POCONOS... AS A WEAK MID-LEVEL
SHORT WAVE MOVES ACROSS THE AREA. LATEST AREA RUC SOUNDINGS ARE
SHOWING CAPE VALUES FROM 400 TO 800 J/KG BUT WITH LOTS OF DRY AIR
THIS AFTERNOON. HI RESOLUTION MODELS ALSO SHOWING SCT-ISOLATED
SHOWERS DEVELOPING OVER NE PA THIS AFTERNOON. CURRENT FORECAST
SEEMS TO HAVE THIS HANDLED VERY WELL WITH ISOLATED POPS FOR
NORTHEAST PA. WILL TWEAK POPS UP IN THE LOCALIZED AREA WHERE
SHOWERS ARE DEVELOPING ATTM... OTHERWISE NO CHANGES TO THE ONGOING
FORECAST. PREVIOUS DISCUSSION BELOW.
UPDATED AT 10 AM... CURRENT FORECAST IN GOOD SHAPE. LATEST 12Z BUF
AND PIT SOUNDINGS SHOWING LOTS OF DRY AIR THROUGH A DEEP LAYER
ALONG WITH SOME CAPPING. FULL MIXING OF THESE SOUNDINGS WOULD
ALLOW FOR TEMPERATURES TO REACH MOSTLY THE MID 80S THIS AFTERNOON.
WATER VAPOR AND BLENDED TPW PRODUCTS SHOWING A LITTLE MORE
MOISTURE OVER EASTERN PA. SHORT WAVE CURRENTLY DIGGING SOUTHEAST
ACROSS NY COULD STILL INTERACT WITH THIS MOISTURE TO PRODUCE A FEW
ISOLATED SHOWERS MAINLY OVER THE SOUTHEAST HALF OF THE FORECAST
AREA THIS AFTERNOON. BASED ON THIS HAVE KEPT POPS IN THE 15 TO 20 PCT
RANGE ACROSS NORTHEAST PA... AND LOWER TO THE NORTH AND WEST.
PREVIOUS DISCUSSION BELOW.
640 AM UPDATE...CURRENT FORECAST IN GOOD SHAPE JUST MINOR SHORT
TERM TEMP/DEW POINT ADJUSTMENTS.
PREVIOUS DISC...
AT 415 AM...SATELLITE SHOWED CLEAR SKIES ACROSS THE REGION WITH A
BIT MORE CLOUD ACROSS THE WYOMING VALLEY AND POCONOS.
SFC HIGH PRES WILL RESIDE OVER THE REGION TODAY AS A BROAD UPPER
LEVEL TROF REMAINS OVER THE NORTHEAST. THIS AFTERNOON WITH
DAYTIME HEATING MODELS INDICATE THE BEST INSTABILITY 700-1200 J/KG
WILL RESIDE ACROSS NORTHEAST PA, THE SOUTHERN CATSKILLS AND ALONG
THE NY/PA BORDER. ONCE AGAIN MODEL SOUNDINGS INDICATE A MID LEVEL
CAP SO ACTIVITY WILL BE CONFINED TO THE AFTERNOON AND EARLY
EVENING HOURS. NOT MUCH OF A TRIGGER TODAY BUT HIGHER DEW POINTS
IN THIS REGION ALONG WITH DAYTIME HEATING SHOULD RESULT IN
ISOLATED CONVECTIVE ACTIVITY.
UNDER MOSTLY SUNNY SKIES MAX TEMPS WILL RANGE IN THE LOWER TO
MIDDLE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT THROUGH FRIDAY NIGHT...UPPER LEVEL HEIGHTS WILL BUILD
OVER THE REGION THROUGH THE PERIOD AS A RIDGE DEVELOPS AND HEIGHTS
RISE TO 590DM BY FRIDAY AFTERNOON. SFC HIGH PRES WILL MOVE OFF THE
EAST COAST PROVIDING A SOUTHERLY FLOW OF MORE HUMID AIR BY FRIDAY
AFTERNOON. SKIES WILL REMAIN PARTLY TO MAINLY CLEAR THROUGH THE
PERIOD WITH MAX TEMPS MODIFYING A COUPLE OF DEGREES EACH DAY. MAX
TEMPS ON THURSDAY WILL RANGE IN THE MID TO UPPER 80S WITH HIGHS
ON FRIDAY MID 80S TO AROUND 90.
AREA SHOULD REMAIN DRY ON THURSDAY DUE TO BUILDING UPPER LEVEL
RIDGE AND LACK OF ANY TRIGGER. ON FRIDAY, SOUTHERLY FLOW WITH
BRING INCREASING DEW POINTS WITH MODELS INDICATING BETTER CAPE
ACROSS THE CENTRAL SOUTHERN TIER AND FINGER LAKES REGION. WITH
CAPE VALUES AROUND 1000J/KG WILL INCLUDE SLIGHT CHC FOR TSRA
DURING THE AFTERNOON OVER THE ABOVE MENTIONED AREAS.
FRIDAY NIGHT, WILL CONTINUE WITH SLIGHT CHC POPS WEST AS MOIST
SOUTHWEST FLOW CONTINUES AND SFC LOW PRES LIFTS NORTH INTO THE
WESTERN LAKES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
345AM UPDATE...NO SIGNIFICANT CHANGES TO PREVIOUS FORECAST OTHER THAN
TWEAKING TEMPS/DP/RH, SKY COVER, AND WINDS/WIND GUSTS. MODELS ARE
IN DISAGREEMENT WITH THE EXTENDED FORECAST, LEADING TO A HIGH
AMOUNT OF UNCERTAINTY. THIS WOULD WARRANT LEAVING CURRENT FORECAST
IN PLACE FOR THE TIME BEING, AS IT REFLECTS THIS.
330 PM TUESDAY UPDATE... WEAK UPPER LEVEL TROUGH DEVELOPING OVER THE
MISSISSIPPI VALLEY WILL GRADUALLY FUNNEL INCREASINGLY MOIST
UNSTABLE AIR NORTH UP THE APPALACHIANS TOWARD OUR AREA FRIDAY
THROUGH SATURDAY. THE GFS IS FASTER THAN THE ECMWF WITH
DEVELOPING SPOTTY QPF OVER THE AREA BY FRIDAY NIGHT AND
SATURDAY... HOWEVER BOTH MODELS WOULD INDICATE A SLOWLY INCREASING
POP THROUGH THIS PERIOD. HOWEVER WILL KEEP POPS GENERALLY IN THE
LOW CHC CATEGORY THROUGH SATURDAY WITH NO STRONG FORCING FOR
ORGANIZED UPWARD MOTION EXPECTED. TEMPERATURES WILL ALSO CONTINUE
A GRADUAL WARMING TREND THROUGH THIS TIME WITH HIGHS MOSTLY IN THE
MID TO UPPER 80S FRIDAY AND SATURDAY... AND NEAR 90 POSSIBLE IN THE
LAKE PLAIN.
NEXT CHC FOR ORGANIZED CONVECTION APPEARS TO BE SUNDAY... ALTHOUGH
CONFIDENCE WITH THIS TIMING IS OBVIOUSLY LOW GIVEN THE LONG RANGE
OF THE FORECAST. HOWEVER AT THIS TIME BOTH THE GFS AND ECMWF ARE
IN GOOD AGREEMENT INDICATING THAT THE TROUGH OVER THE MIDWEST
WILL SHIFT EAST WITH POTENTIAL FOR AN ORGANIZED ROUND OF SHOWERS
AND THUNDERSTORMS SUNDAY INTO MONDAY. CONDITIONS WILL REMAIN WARM
AND PROBABLY QUITE HUMID INTO EARLY NEXT WEEK.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE WILL KEEP VFR IN PLACE THROUGH THE TAF PERIOD.
THERE IS ANOTHER SLIGHT CHANCE OF SOME LIGHT RAIN SHOWERS IN THE
KAVP AREA ONCE AGAIN TODAY. HOWEVER, WITH LOW CONFIDENCE, HAVE NOT
PLACED ANY SHRA IN TAFS AT THIS TIME.
LIGHT AND VARIABLE WINDS WILL CONTINUE INTO MID DAY TOMORROW. SOME
LOCATIONS MAY STAY LIGHT AND VARIABLE THROUGH THE TAF PERIOD,
WHILE OTHER LOCATIONS HAVE TERRAIN DRIVEN WIND AROUND 5KTS DURING
THE AFTERNOON.
OUTLOOK...
THU THROUGH FRI...VFR.
SAT AND SUN...GENERALLY VFR. CHC MVFR SHWRS/TSTMS SAT
AFTN/EVE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MSE/RRM
SHORT TERM...RRM
LONG TERM...MSE/SLI
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
346 AM EDT WED JUL 11 2012
.SYNOPSIS...
OTHER THAN AN ISOLATED SHOWER OR THUNDERSTORM WEDNESDAY
AFTERNOON...PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED THROUGH LATE
WEEK. TEMPERATURES WILL GRADUALLY WARM AS THE WEEK PROGRESSES.
THE NEXT CHANCE FOR RAIN WILL COME ON THE WEEKEND...AS A LARGE
HIGH PRESSURE DEVELOPS OFF THE EAST COAST...BRINGING A MOIST AND
HUMID SOUTHERLY FLOW OF AIR TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1230 AM UPDATE...RADAR TRENDS SHOW CONVECTION OVER SOUTHERN
LUZERNE AND LACKAWANNA COUNTIES CONTINUE TO WEAKEN AND DISSIPATE.
HRRR INDICATES ACTIVITY WILL END BY 07Z BUT CURRENT TRENDS WOULD
IMPLY SOONER, WILL CONTINUE WITH CURRENT FORECAST OF ENDING SHOWERS
BY 06Z.
10 PM UPDATE...
MORE ADJUSTMENTS TO KEEP THE SHOWERS GOING IN NE PA. STILL SOME
LOW LEVEL INSTABILITY. WITH THE CLOUDS TEMPERATURES HAVE NOT
FALLEN VERY QUICKLY. WITH THE LOW LEVEL CONVERGENCE POOLING
DEW POINT TEMPS IN THE 60S. MODELS NOT HANDLING WELL. EXTENDING THE
SHOWERS INTO THE EARLY MORNING. MOVEMENT IS SLOWLY TO THE ESE BUT
SOME HEAVY RAIN STILL THERE. SHOULD BE A SLOW DECREASE IN COVERAGE
AND INTENSITY AS THE LOW LEVELS COOL AND THE SHORT WAVE PASSES TO
THE SE. CLEAR SKIES AND LIGHT TO CALM WINDS IN CENTRAL NY HAS
ALLOWED TEMPERATURES TO FALL FASTER THAN EXPECTED.
7 PM UPDATE...
SHOWERS AND CLOUDY SKIES HANGING ON ALONG A TROF IN NORTHEAST PA
AND SULLIVAN COUNTY NY. ADJUSTED GRIDS TO HANG ONTO THE CLOUDS AND
SHOWERS FOR A FEW MORE HOURS. WITH CLEAR SKIES AND DEW POINT
TEMPERATURES IN THE LOW AND MID 50S IN NEW YORK ADJUSTED THE MIN
TEMPS DOWN THERE.
PREVIOUS DISCUSSION...
RADAR SHOWS ISLD TO SCT SHRA FORMING OVER THE CENTRAL SOUTHERN
TIER. NOT SURE HOW MUCH OF THIS ACVTY IS REACHING THE GROUND BUT
ASSUMING QUITE A BIT OF IT IS...SO UPPED POPS TO SCT CATEGORY. THE
CONVECTION WAS FORMING ALONG A BNDRY THAT WAS DEVELOPING FROM
ABOUT RME TO BTWN ITH AND BGM TO ELM. WATER VAPOR IMAGERY SHOWS A
SHORT WAVE DROPPING SOUTHEAST TWD NY STATE AND PA. THIS WAVE WAS
APPARENTLY SUPPLYING ENUF LIFT DESPITE THE FACT THAT IT WAS
SHEARING OUT AS PER WATER VAPOR. THE WAVE WAS APPARENTLY ORGANIZING
A SFC BNDRY AND INITIATING CONVECTION. MODEL SOUNDINGS SHOW LITTLE
CAPE...GENERALLY BTWN 250 TO 500 J/KG OF MIXED LAYER CAPE. THE 0-6
KM WAS IMPRESSIVE RUNNING CLOSE TO 35 KNOTS BUT THE 0-1 KM AND 0-3
KM WERE VERY WEAK. NOT EXPECTING ANY SVR CONVECTION BUT AS THE
AFTERNOON HEATING PROGRESSES AND THE SHORT WAVE CONTS TO TRACK
SOUTHEAST BELIEVE ACVTY WILL HOLD TOGETHER INTO NRN PA/POCONOS BY LATE
AFTERNOON/EARLY EVENING AS SHRT WAVE PUSHES FRONT SOUTHWARD INTO
PA. LATEST HRRR SHOWS THIS EVOLUTION VERY WELL AND WILL TWEAK POPS
AGAIN TO BETTER REFLECT TIMING AND COVERAGE BASED ON HRRR. BELIEVE
THUNDER WILL BE ISLD THOUGH AS SOUNDING EQUILIBRIUM LEVELS ARE
REALLY NOT THAT HIGH RUNNING MAINLY BELOW 25 KFT.
ACVTY WILL WANE AFTER SUNSET AND WITH THE PASSAGE OF THIS UPPER
LEVEL WAVE. FOG CHECKLIST SUGGESTS PATCHY VALLEY FOG...BELIEVE
THERE WILL BE A BIT MORE FOG E OF BGM IN THE HILLY TERRAIN THAN TO
THE W BASED ON THE FACT THAT IT HAS BEEN FAIRLY DRY AND THE
CHEMUNG RIVER WAS RUNNING VERY LOW. HENCE THERE WON/T BE AS MUCH
WATER VAPOR OFF THE CHEMUNG VS THE SUSQUEHANNA WHICH IS RUNNING A
BIT HIGHER. THIS IS OFTEN OBSERVED DURING RELATIVELY DRY SPELLS
AND WE SEE MORE FOG IN THE VALLEYS E OF BGM...VS ELM AND VCNTY.
FOR WEDNESDAY...DEW POINTS ARE A BIT HIGHER ESP IN FROM NE PA TO
THE CATSKILLS AS ANTHR SHRT WAVE TRACKS SOUTHWARD FROM CANADA. THE
LL FLOW WILL TURN MORE SWRLY INTO NRN PA IN RESPONSE TO THIS
SHRT WAVE WED PM AND LIKELY WILL SPARK OFF MORE ISLD SHRA AND TSRA
BY AFTERNOON. I SEE LESS THE FARTHER N YOU GO INTO C NY. SO HIGHER
POPS FOR NE PA/CATSKILLS WED PM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
WARM DRY WEATHER CAN BE EXPECTED THROUGH THIS PERIOD AS HIGH
PRESSURE HOLDS NEARLY STEADY OFF THE EAST COAST WHILE MID-LEVEL
HEIGHTS CONTINUE TO SLOWLY RISE. PATCHY FOG MAY FORM IN THE RIVER
VALLEYS LATE WEDNESDAY NIGHT. MODEST CAPE VALUES DEVELOP WITH
DIURNAL HEATING THURSDAY AFTERNOON... BUT WITH NO FORCING AND LOTS
OF DRY AIR IN PLACE EXPECT DRY CONDITIONS TO CONTINUE.
TEMPERATURES THURSDAY AFTERNOON WILL BE A FEW DEGREES ABOVE
NORMAL... GENERALLY IN THE MID 80S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
345AM UPDATE...NO SIGNIFICANT CHANGES TO PREVIOUS FORECAST OTHER THAN
TWEAKING TEMPS/DP/RH, SKY COVER, AND WINDS/WIND GUSTS. MODELS ARE
IN DISAGREEMENT WITH THE EXTENDED FORECAST, LEADING TO A HIGH
AMOUNT OF UNCERTAINTY. THIS WOULD WARRANT LEAVING CURRENT FORECAST
IN PLACE FOR THE TIME BEING, AS IT REFLECTS THIS.
330 PM TUESDAY UPDATE... WEAK UPPER LEVEL TROUGH DEVELOPING OVER THE
MISSISSIPPI VALLEY WILL GRADUALLY FUNNEL INCREASINGLY MOIST
UNSTABLE AIR NORTH UP THE APPALACHIANS TOWARD OUR AREA FRIDAY
THROUGH SATURDAY. THE GFS IS FASTER THAN THE ECMWF WITH
DEVELOPING SPOTTY QPF OVER THE AREA BY FRIDAY NIGHT AND
SATURDAY... HOWEVER BOTH MODELS WOULD INDICATE A SLOWLY INCREASING
POP THROUGH THIS PERIOD. HOWEVER WILL KEEP POPS GENERALLY IN THE
LOW CHC CATEGORY THROUGH SATURDAY WITH NO STRONG FORCING FOR
ORGANIZED UPWARD MOTION EXPECTED. TEMPERATURES WILL ALSO CONTINUE
A GRADUAL WARMING TREND THROUGH THIS TIME WITH HIGHS MOSTLY IN THE
MID TO UPPER 80S FRIDAY AND SATURDAY... AND NEAR 90 POSSIBLE IN THE
LAKE PLAIN.
NEXT CHC FOR ORGANIZED CONVECTION APPEARS TO BE SUNDAY... ALTHOUGH
CONFIDENCE WITH THIS TIMING IS OBVIOUSLY LOW GIVEN THE LONG RANGE
OF THE FORECAST. HOWEVER AT THIS TIME BOTH THE GFS AND ECMWF ARE
IN GOOD AGREEMENT INDICATING THAT THE TROUGH OVER THE MIDWEST
WILL SHIFT EAST WITH POTENTIAL FOR AN ORGANIZED ROUND OF SHOWERS
AND THUNDERSTORMS SUNDAY INTO MONDAY. CONDITIONS WILL REMAIN WARM
AND PROBABLY QUITE HUMID INTO EARLY NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE WILL KEEP VFR IN PLACE THROUGH THE TAF PERIOD.
SOME RESIDUAL CLOUD COVER OVER NEPA WILL CLEAR OVER THE NEXT
COUPLE OF HOURS. WHILE CURRENTLY NOT IN THE TAFS, THERE IS A
CHANCE THAT SOME FOG MAY DEVELOP AT KAVP, AND POSSIBLY EVEN KELM
DUE TO SOME SFC MOISTURE FROM RAIN SHOWERS YESTERDAY.
LIGHT AND VARIABLE WINDS WILL CONTINUE INTO MID DAY TOMORROW. SOME
LOCATIONS MAY STAY LIGHT AND VARIABLE THROUGH THE TAF PERIOD,
WHILE OTHER LOCATIONS HAVE TERRAIN DRIVEN WIND AROUND 5KTS DURING
THE AFTERNOON.
OUTLOOK...
THU THROUGH FRI...VFR.
SAT AND SUN...GENERALLY VFR. CHC MVFR SHWRS/TSTMS SAT
AFTN/EVE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/RRM/TAC
SHORT TERM...MSE
LONG TERM...MSE/SLI
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
125 AM EDT WED JUL 11 2012
.SYNOPSIS...
OTHER THAN AN ISOLATED SHOWER OR THUNDERSTORM WEDNESDAY
AFTERNOON...PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED THROUGH LATE
WEEK. TEMPERATURES WILL GRADUALLY WARM AS THE WEEK PROGRESSES.
THE NEXT CHANCE FOR RAIN WILL COME ON THE WEEKEND...AS A LARGE
HIGH PRESSURE DEVELOPS OFF THE EAST COAST...BRINGING A MOIST AND
HUMID SOUTHERLY FLOW OF AIR TO THE REGION.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...RADAR TRENDS SHOW CONVECTION OVER SOUTHERN
LUZERNE AND LACKAWANNA COUNTIES CONTINUE TO WEAKEN AND DISSIPATE.
HRRR INDICATES ACTIVITY WILL END BY 07Z BUT CURRENT TRENDS WOULD
IMPLY SOONER, WILL CONTINUE WITH CURRENT FORECAST OF ENDING SHOWERS
BY 06Z.
10 PM UPDATE...
MORE ADJUSTMENTS TO KEEP THE SHOWERS GOING IN NE PA. STILL SOME
LOW LEVEL INSTABILITY. WITH THE CLOUDS TEMPERATURES HAVE NOT
FALLEN VERY QUICKLY. WITH THE LOW LEVEL CONVERGENCE POOLING
DEW POINT TEMPS IN THE 60S. MODELS NOT HANDLING WELL. EXTENDING THE
SHOWERS INTO THE EARLY MORNING. MOVEMENT IS SLOWLY TO THE ESE BUT
SOME HEAVY RAIN STILL THERE. SHOULD BE A SLOW DECREASE IN COVERAGE
AND INTENSITY AS THE LOW LEVELS COOL AND THE SHORT WAVE PASSES TO
THE SE. CLEAR SKIES AND LIGHT TO CALM WINDS IN CENTRAL NY HAS
ALLOWED TEMPERATURES TO FALL FASTER THAN EXPECTED.
7 PM UPDATE...
SHOWERS AND CLOUDY SKIES HANGING ON ALONG A TROF IN NORTHEAST PA
AND SULLIVAN COUNTY NY. ADJUSTED GRIDS TO HANG ONTO THE CLOUDS AND
SHOWERS FOR A FEW MORE HOURS. WITH CLEAR SKIES AND DEW POINT
TEMPERATURES IN THE LOW AND MID 50S IN NEW YORK ADJUSTED THE MIN
TEMPS DOWN THERE.
PREVIOUS DISCUSSION...
RADAR SHOWS ISLD TO SCT SHRA FORMING OVER THE CENTRAL SOUTHERN
TIER. NOT SURE HOW MUCH OF THIS ACVTY IS REACHING THE GROUND BUT
ASSUMING QUITE A BIT OF IT IS...SO UPPED POPS TO SCT CATEGORY. THE
CONVECTION WAS FORMING ALONG A BNDRY THAT WAS DEVELOPING FROM
ABOUT RME TO BTWN ITH AND BGM TO ELM. WATER VAPOR IMAGERY SHOWS A
SHORT WAVE DROPPING SOUTHEAST TWD NY STATE AND PA. THIS WAVE WAS
APPARENTLY SUPPLYING ENUF LIFT DESPITE THE FACT THAT IT WAS
SHEARING OUT AS PER WATER VAPOR. THE WAVE WAS APPARENTLY ORGANIZING
A SFC BNDRY AND INITIATING CONVECTION. MODEL SOUNDINGS SHOW LITTLE
CAPE...GENERALLY BTWN 250 TO 500 J/KG OF MIXED LAYER CAPE. THE 0-6
KM WAS IMPRESSIVE RUNNING CLOSE TO 35 KNOTS BUT THE 0-1 KM AND 0-3
KM WERE VERY WEAK. NOT EXPECTING ANY SVR CONVECTION BUT AS THE
AFTERNOON HEATING PROGRESSES AND THE SHORT WAVE CONTS TO TRACK
SOUTHEAST BELIEVE ACVTY WILL HOLD TOGETHER INTO NRN PA/POCONOS BY LATE
AFTERNOON/EARLY EVENING AS SHRT WAVE PUSHES FRONT SOUTHWARD INTO
PA. LATEST HRRR SHOWS THIS EVOLUTION VERY WELL AND WILL TWEAK POPS
AGAIN TO BETTER REFLECT TIMING AND COVERAGE BASED ON HRRR. BELIEVE
THUNDER WILL BE ISLD THOUGH AS SOUNDING EQUILIBRIUM LEVELS ARE
REALLY NOT THAT HIGH RUNNING MAINLY BELOW 25 KFT.
ACVTY WILL WANE AFTER SUNSET AND WITH THE PASSAGE OF THIS UPPER
LEVEL WAVE. FOG CHECKLIST SUGGESTS PATCHY VALLEY FOG...BELIEVE
THERE WILL BE A BIT MORE FOG E OF BGM IN THE HILLY TERRAIN THAN TO
THE W BASED ON THE FACT THAT IT HAS BEEN FAIRLY DRY AND THE
CHEMUNG RIVER WAS RUNNING VERY LOW. HENCE THERE WON/T BE AS MUCH
WATER VAPOR OFF THE CHEMUNG VS THE SUSQUEHANNA WHICH IS RUNNING A
BIT HIGHER. THIS IS OFTEN OBSERVED DURING RELATIVELY DRY SPELLS
AND WE SEE MORE FOG IN THE VALLEYS E OF BGM...VS ELM AND VCNTY.
FOR WEDNESDAY...DEW POINTS ARE A BIT HIGHER ESP IN FROM NE PA TO
THE CATSKILLS AS ANTHR SHRT WAVE TRACKS SOUTHWARD FROM CANADA. THE
LL FLOW WILL TURN MORE SWRLY INTO NRN PA IN RESPONSE TO THIS
SHRT WAVE WED PM AND LIKELY WILL SPARK OFF MORE ISLD SHRA AND TSRA
BY AFTERNOON. I SEE LESS THE FARTHER N YOU GO INTO C NY. SO HIGHER
POPS FOR NE PA/CATSKILLS WED PM.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
WARM DRY WEATHER CAN BE EXPECTED THROUGH THIS PERIOD AS HIGH
PRESSURE HOLDS NEARLY STEADY OFF THE EAST COAST WHILE MID-LEVEL
HEIGHTS CONTINUE TO SLOWLY RISE. PATCHY FOG MAY FORM IN THE RIVER
VALLEYS LATE WEDNESDAY NIGHT. MODEST CAPE VALUES DEVELOP WITH
DIURNAL HEATING THURSDAY AFTERNOON... BUT WITH NO FORCING AND LOTS
OF DRY AIR IN PLACE EXPECT DRY CONDITIONS TO CONTINUE.
TEMPERATURES THURSDAY AFTERNOON WILL BE A FEW DEGREES ABOVE
NORMAL... GENERALLY IN THE MID 80S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
330 PM TUESDAY UPDATE... WEAK UPPER LEVEL TROUGH DEVELOPING OVER THE
MISSISSIPPI VALLEY WILL GRADUALLY FUNNEL INCREASINGLY MOIST
UNSTABLE AIR NORTH UP THE APPALACHIANS TOWARD OUR AREA FRIDAY
THROUGH SATURDAY. THE GFS IS FASTER THAN THE ECMWF WITH
DEVELOPING SPOTTY QPF OVER THE AREA BY FRIDAY NIGHT AND
SATURDAY... HOWEVER BOTH MODELS WOULD INDICATE A SLOWLY INCREASING
POP THROUGH THIS PERIOD. HOWEVER WILL KEEP POPS GENERALLY IN THE
LOW CHC CATEGORY THROUGH SATURDAY WITH NO STRONG FORCING FOR
ORGANIZED UPWARD MOTION EXPECTED. TEMPERATURES WILL ALSO CONTINUE
A GRADUAL WARMING TREND THROUGH THIS TIME WITH HIGHS MOSTLY IN THE
MID TO UPPER 80S FRIDAY AND SATURDAY... AND NEAR 90 POSSIBLE IN THE
LAKE PLAIN.
NEXT CHC FOR ORGANIZED CONVECTION APPEARS TO BE SUNDAY... ALTHOUGH
CONFIDENCE WITH THIS TIMING IS OBVIOUSLY LOW GIVEN THE LONG RANGE
OF THE FORECAST. HOWEVER AT THIS TIME BOTH THE GFS AND ECMWF ARE
IN GOOD AGREEMENT INDICATING THAT THE TROUGH OVER THE MIDWEST
WILL SHIFT EAST WITH POTENTIAL FOR AN ORGANIZED ROUND OF SHOWERS
AND THUNDERSTORMS SUNDAY INTO MONDAY. CONDITIONS WILL REMAIN WARM
AND PROBABLY QUITE HUMID INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE WILL KEEP VFR IN PLACE THROUGH THE TAF PERIOD.
SOME RESIDUAL CLOUD COVER OVER NEPA WILL CLEAR OVER THE NEXT
COUPLE OF HOURS. WHILE CURRENTLY NOT IN THE TAFS, THERE IS A
CHANCE THAT SOME FOG MAY DEVELOP AT KAVP, AND POSSIBLY EVEN KELM
DUE TO SOME SFC MOISTURE FROM RAIN SHOWERS YESTERDAY.
LIGHT AND VARIABLE WINDS WILL CONTINUE INTO MID DAY TOMORROW. SOME
LOCATIONS MAY STAY LIGHT AND VARIABLE THROUGH THE TAF PERIOD,
WHILE OTHER LOCATIONS HAVE TERRAIN DRIVEN WIND AROUND 5KTS DURING
THE AFTERNOON.
OUTLOOK...
THU THROUGH FRI...VFR.
SAT AND SUN...GENERALLY VFR. CHC MVFR SHWRS/TSTMS SAT
AFTN/EVE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/RRM/TAC
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1236 AM EDT WED JUL 11 2012
.SYNOPSIS...
OTHER THAN AN ISOLATED SHOWER OR THUNDERSTORM WEDNESDAY
AFTERNOON...PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED THROUGH LATE
WEEK. TEMPERATURES WILL GRADUALLY WARM AS THE WEEK PROGRESSES.
THE NEXT CHANCE FOR RAIN WILL COME ON THE WEEKEND...AS A LARGE
HIGH PRESSURE DEVELOPS OFF THE EAST COAST...BRINGING A MOIST AND
HUMID SOUTHERLY FLOW OF AIR TO THE REGION.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...RADAR TRENDS SHOW CONVECTION OVER SOUTHERN
LUZERNE AND LACKAWANNA COUNTIES CONTINUE TO WEAKEN AND DISSIPATE.
HRRR INDICATES ACTIVITY WILL END BY 07Z BUT CURRENT TRENDS WOULD
IMPLY SOONER, WILL CONTINUE WITH CURRENT FORECAST OF ENDING SHOWERS
BY 06Z.
10 PM UPDATE...
MORE ADJUSTMENTS TO KEEP THE SHOWERS GOING IN NE PA. STILL SOME
LOW LEVEL INSTABILITY. WITH THE CLOUDS TEMPERATURES HAVE NOT
FALLEN VERY QUICKLY. WITH THE LOW LEVEL CONVERGENCE POOLING
DEWPOINT TEMPS IN THE 60S. MODELS NOT HANDLING WELL. EXTENDING THE
SHOWERS INTO THE EARLY MORNING. MOVEMENT IS SLOWLY TO THE ESE BUT
SOME HEAVY RAIN STILL THERE. SHOULD BE A SLOW DECREASE IN COVERAGE
AND INTENSITY AS THE LOW LEVELS COOL AND THE SHORT WAVE PASSES TO
THE SE. CLEAR SKIES AND LIGHT TO CALM WINDS IN CENTRAL NY HAS
ALLOWED TEMPERATURES TO FALL FASTER THAN EXPECTED.
7 PM UPDATE...
SHOWERS AND CLOUDY SKIES HANGING ON ALONG A TROF IN NORTHEAST PA
AND SULLIVAN COUNTY NY. ADJUSTED GRIDS TO HANG ONTO THE CLOUDS AND
SHOWERS FOR A FEW MORE HOURS. WITH CLEAR SKIES AND DEWPOINT
TEMPERATURES IN THE LOW AND MID 50S IN NEW YORK ADJUSTED THE MIN
TEMPS DOWN THERE.
PREVIOUS DISCUSSION...
RADAR SHOWS ISLD TO SCT SHRA FORMING OVER THE CENTRAL SOUTHERN
TIER. NOT SURE HOW MUCH OF THIS ACVTY IS REACHING THE GROUND BUT
ASSUMING QUITE A BIT OF IT IS...SO UPPED POPS TO SCT CATEGORY. THE
CONVECTION WAS FORMING ALONG A BNDRY THAT WAS DEVELOPING FROM
ABOUT RME TO BTWN ITH AND BGM TO ELM. WATER VAPOR IMAGERY SHOWS A
SHORT WAVE DROPPING SOUTHEAST TWD NY STATE AND PA. THIS WAVE WAS
APPARENTLY SUPPLYING ENUF LIFT DESPITE THE FACT THAT IT WAS
SHEARING OUT AS PER WATER VAPOR. THE WAVE WAS APPARENTLY ORGANIZING
A SFC BNDRY AND INITIATING CONVECTION. MODEL SOUNDINGS SHOW LITTLE
CAPE...GENERALLY BTWN 250 TO 500 J/KG OF MIXED LAYER CAPE. THE 0-6
KM WAS IMPRESSIVE RUNNING CLOSE TO 35 KNOTS BUT THE 0-1 KM AND 0-3
KM WERE VERY WEAK. NOT EXPECTING ANY SVR CONVECTION BUT AS THE
AFTERNOON HEATING PROGRESSES AND THE SHORT WAVE CONTS TO TRACK
SOUTHEAST BELIEVE ACVTY WILL HOLD TOGETHER INTO NRN PA/POCONOS BY LATE
AFTERNOON/EARLY EVENING AS SHRT WAVE PUSHES FRONT SOUTHWARD INTO
PA. LATEST HRRR SHOWS THIS EVOLUTION VERY WELL AND WILL TWEAK POPS
AGAIN TO BETTER REFLECT TIMING AND COVERAGE BASED ON HRRR. BELIEVE
THUNDER WILL BE ISLD THOUGH AS SOUNDING EQUILIBRIUM LEVELS ARE
REALLY NOT THAT HIGH RUNNING MAINLY BELOW 25 KFT.
ACVTY WILL WANE AFTER SUNSET AND WITH THE PASSAGE OF THIS UPPER
LEVEL WAVE. FOG CHECKLIST SUGGESTS PATCHY VALLEY FOG...BELIEVE
THERE WILL BE A BIT MORE FOG E OF BGM IN THE HILLY TERRAIN THAN TO
THE W BASED ON THE FACT THAT IT HAS BEEN FAIRLY DRY AND THE
CHEMUNG RIVER WAS RUNNING VERY LOW. HENCE THERE WON/T BE AS MUCH
WATER VAPOR OFF THE CHEMUNG VS THE SUSQUEHANNA WHICH IS RUNNING A
BIT HIGHER. THIS IS OFTEN OBSERVED DURING RELATIVELY DRY SPELLS
AND WE SEE MORE FOG IN THE VALLEYS E OF BGM...VS ELM AND VCNTY.
FOR WEDNESDAY...DEWPOINTS ARE A BIT HIGHER ESP IN FROM NE PA TO
THE CATSKILLS AS ANTHR SHRT WAVE TRACKS SOUTHWARD FROM CANADA. THE
LL FLOW WILL TURN MORE SWRLY INTO NRN PA IN RESPONSE TO THIS
SHRT WAVE WED PM AND LIKELY WILL SPARK OFF MORE ISLD SHRA AND TSRA
BY AFTERNOON. I SEE LESS THE FARTHER N YOU GO INTO C NY. SO HIGHER
POPS FOR NE PA/CATSKILLS WED PM.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
WARM DRY WEATHER CAN BE EXPECTED THROUGH THIS PERIOD AS HIGH
PRESSURE HOLDS NEARLY STEADY OFF THE EAST COAST WHILE MID-LEVEL
HEIGHTS CONTINUE TO SLOWLY RISE. PATCHY FOG MAY FORM IN THE RIVER
VALLEYS LATE WEDNESDAY NIGHT. MODEST CAPE VALUES DEVELOP WITH
DIURNAL HEATNIG THURSDAY AFTERNOON... BUT WITH NO FORCING AND LOTS
OF DRY AIR IN PLACE EXPECT DRY CONDITIONS TO CONTINUE.
TEMPERATURES THURSDAY AFTERNOON WILL BE A FEW DEGREES ABOVE
NORMAL... GENERALLY IN THE MID 80S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
330 PM TUESDAY UPDATE... WEAK UPPER LEVEL TROUGH DEVELOPING OVER THE
MISSISSIPPI VALLEY WILL GRADUALLY FUNNEL INCREASINGLY MOIST
UNSTABLE AIR NORTH UP THE APPALACHIANS TOWARD OUR AREA FRIDAY
THROUGH SATURDAY. THE GFS IS FASTER THAN THE ECMWF WITH
DEVELOPING SPOTTY QPF OVER THE AREA BY FRIDAY NIGHT AND
SATURDAY... HOWEVER BOTH MODELS WOULD INDICATE A SLOWLY INCREASING
POP THROUGH THIS PERIOD. HWOEVER WILL KEEP POPS GENERALLY IN THE
LOW CHC CATEGORY THROUGH SATURDAY WITH NO STRONG FORCING FOR
ORGANIZED UPWARD MOTION EXPECTED. TEMPERATURES WILL ALSO CONTINUE
A GRADUAL WARMING TREND THROUGH THIS TIME WITH HIGHS MOSTLY IN THE
MID TO UPPER 80S FRIDAY AND SATURDAY... AND NEAR 90 POSSIBLE IN THE
LAKE PLAIN.
NEXT CHC FOR ORGANIZED CONVECTION APPEARS TO BE SUNDAY... ALTHOUGH
CONFIDENCE WITH THIS TIMING IS OBVIOUSLY LOW GIVEN THE LONG RANGE
OF THE FORECAST. HOWEVER AT THIS TIME BOTH THE GFS AND ECMWF ARE
IN GOOD AGREEMENT INDICATING THAT THE TROUGH OVER THE MIDWEST
WILL SHIFT EAST WITH POTENTIAL FOR AN ORGANIZED ROUND OF SHOWERS
AND THUNDERSTORMS SUNDAY INTO MONDAY. CONDITIONS WILL REMAIN WARM
AND PROBABLY QUITE HUMID INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
UPR WV PASSING THRU NE PA WILL TRIGGER A FEW SHWRS ARND AVP FOR
THE NEXT CPL HRS...OTRW LTL IN THE WAY OF WX THIS PD. VFR CONDS
WILL PREVAIL THRU THE PD. ONCE AGAIN...IT LOOKS A BIT TOO DRY FOR
XTNSV FOG FORMATION AT ELM. LGT WINDS TNGT WILL BECOME NLY AND WED
WITH MIXING.
OUTLOOK...
THU THROUGH FRI...VFR.
SAT AND SUN...GENERALLY VFR. CHC MVFR SHWRS/TSTMS SAT
AFTN/EVE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/RRM/TAC
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1036 PM EDT THU JUL 12 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT HAS ACTUALLY PUSHED SOUTH THROUGH
WILMINGTON...WHITEVILLE...CONWAY...MARION AND FLORENCE THIS EVENING
WHERE WEAK NORTHEAST WINDS ARE NOW BEING OBSERVED. ABOVE AND AHEAD
OF THE BOUNDARY NO INCREASE IN SOUTHEAST WINDS ARE EXPECTED SO THERE
IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT BACK TO
THE THE NORTH. THERE IS LITTLE REAL AIRMASS DIFFERENCE ON EITHER
SIDE OF THE FRONT SO IMPACTS ON SENSIBLE WEATHER (OTHER THAN WIND
DIRECTION) ARE LIKELY TO BE MINOR. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A STATIONARY FRONT ACROSS THE CAROLINAS IS OUTLINED ALONG A WEAK
PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST TO NORTHEAST WINDS.
THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE NC ACROSS SOUTHERN
DUPLIN AND SAMPSON COUNTIES TO NEAR FAYETTEVILLE...THEN
SOUTHWESTWARD THROUGH BENNETTSVILLE AND DARLINGTON TO JUST NORTH OF
COLUMBIA. THUNDERSTORMS IGNITED TODAY ALONG THIS FRONT AND ALSO
ALONG THE SEABREEZE BOUNDARY...PUSHED SLOWLY NORTHWESTWARD BY THE
0-6 KM MEAN WIND. SURFACE-BASED INSTABILITY HAS BEEN NEARLY
EXHAUSTED NOW WITH RADAR PRECIPITATION ESTIMATES SHOWING AT LEAST 80
PERCENT OF OUR FORECAST AREA RECEIVED SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY..IT WILL TURN DECIDEDLY DRIER AS WE MOVE FROM
FRI TO SAT WITH PRECIPITABLE WATER VALUES DROPPING FROM AROUND 2
INCHES FRI TO ONE AND A QUARTER INCHES DURING SAT.
BERMUDA RIDGE WILL EXPAND FROM THE WESTERN ATLANTIC AND ACROSS THE
EASTERN CAROLINAS THIS PERIOD...WITH A DEEP EASTERLY FLOW ENVELOPING
THE AREA. FRI WILL BEGIN WITH AN INVERTED TROUGH NEAR OR AT THE
COAST AND MOVING WESTWARD. THERE IS ALSO A SUBTLE FEATURE ALOFT
BEING DEPICTED BY THE MODELS...MOVING WESTWARD DURING FRI. THIS
COUPLED WITH THE SEABREEZE SHOULD BRING ANOTHER GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO COASTAL LOCATIONS DURING THE MORNING
WITH POPS INCREASING INLAND AS THESE FEATURES MOVE INLAND DURING THE
AFTERNOON WHILE LOWERING AT THE COAST. AT THIS TIME...WILL HOLD
COVERAGE AT SCATTERED ALTHOUGH LOCALLY...COVERAGE MAY BECOME
NUMEROUS. STORM MOTIONS AROUND 5 KT AND HIGH ATMOSPHERIC WATER
CONTENT SHOULD YIELD SLOW MOVING THUNDERSTORMS WITH HEAVY DOWNPOURS.
THIS MAY RESULT IN PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. EXAMINATION OF OTHER PARAMETERS INDICATE THE RISK FOR SEVERE
WEATHER IS OTHERWISE LOW AT THIS TIME.
SAT...DRIER AIR AND DEVELOPING CAP AROUND 8-10 KFT...WILL NOT BE AN
ENVIRONMENT CONDUCIVE FOR CONVECTION...EVEN ALONG THE SEABREEZE.
WILL CONFINE POPS TO SMALL CHANCE AT THIS TIME.
IT SHOULD BE NOTED THAT WITH THE DEVELOPING AND DEEPENING EASTERLY
FLOW...NOCTURNAL SHOWERS DEVELOPING ACROSS THE CLIMATOLOGICALLY
FAVORED WATERS MAY MOVE ONSHORE OVERNIGHT/EARLY MORNING HOURS AND
THIS SEEMS MOST PLAUSIBLE LATE FRI NIGHT AND SAT MORNING.
TEMPS WILL NOT DEVIATE MUCH FROM NORMAL VALUES FOR MID JULY...WITH
HIGHS AND LOWS GENERALLY STAYING WITHIN A DEG OR TWO OF NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...RETURN FLOW WILL CONTINUE AROUND BERMUDA
HIGH THROUGH THE PERIOD. LOCAL AREA WILL REMAIN ON THE WESTERN
PERIPHERY OF THE RIDGE WITH DEEPER S-SW RETURN FLOW THROUGH THE
LOW LEVELS OF THE ATMOSPHERE. A MINOR PERTURBATION IN THE FLOW MAY
RIDE THROUGH FROM THE EAST SUN INTO MON WITH INCREASED CHC OF
PCP...BUT BASICALLY EXPECT DRIER MORE SUBSIDENT CONDITIONS THROUGH
THE MID TO UPPER LEVELS THROUGH MOST OF THE PERIOD. OVERALL EXPECT
MORE TYPICAL SUMMERTIME WEATHER WITH CU BUILDING EACH AFTERNOON
AND CONVECTION POSSIBLE MAINLY ALONG SEA BREEZE AND FURTHER INLAND
ALONG PIEDMONT TROUGH.
AS RIDGE GETS SUPPRESSED A BIT FURTHER SOUTH HEADING LATE
MON THROUGH MID WEEK...A BETTER WESTERLY COMPONENT TO THE FLOW WILL
DEVELOP THROUGH THE LOW LEVELS. THIS SHOULD HELP TO PRODUCE A SLIGHT
WARMING TREND. MAX TEMPS WILL REACH BETWEEN 90 AND 95 MOST DAYS AND
REMAIN IN THE 70S OVERNIGHT.
AT THE VERY END OF PERIOD MAY SEE NORTHERN STREAM SHORTWAVE DIG DOWN
INTO THE CAROLINAS AND PUSH A FRONT THROUGH LATE THURS INTO FRI.
THIS WOULD PRODUCE MORE WIDESPREAD CONVECTION BUT TOO FAR OUT TO
FEEL CONFIDENT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...PERIODS OF MVFR OVERNIGHT DUE FOG/STRATUS LATE TONIGHT
INTO EARLY FRIDAY MORNING. OTHERWISE EXPECT VFR...WITH AFTERNOON
CONVECTION POSSIBLE.
CURRENT RADAR IMAGERY DEPICTS SHOWERS AFFECTING THE INLAND
SITES...GRADUALLY PROGRESSING NORTHWARD. FCST GUIDANCE SUGGESTS
ADDITIONAL SHRA TO DEVELOP LATE OVERNIGHT OFFSHORE...MOVING ONSHORE
AFTER MIDNIGHT. FOR NOW HAVE INTRODUCED VCSH. GIVEN ABUNDANT
RAINFALL IN SOME LOCATIONS AND LIGHT AND VARIABLE WINDS...ANTICIPATE
MVFR FOG...WITH LOW CIGS DUE TO STRATUS POSSIBLE AS WELL BY EARLY
MORNING. EXPECT ANY LINGERING FOG TO CLEAR OUT BY MORNING..WITH
GUIDANCE DEPICTING CIGS AROUND 2500-3000FT AND ISOLATED SHRA FOR
MOST OF THE EARLY AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED
SHRA/TSRA ANTICIPATED FRIDAY AFTERNOON...WITH SOUTH-SOUTHEAST
WINDS AOB 10 KTS AND GUSTS POSSIBLE IN ANY STORM. ANTICIPATE STORMS
TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...HIGH PRESSURE WILL DOMINATE THE MARINE
ENVIRONMENT. A WEAK INVERTED TROUGH IS EXPECTED TO DEVELOP AND
PERSIST THROUGH AT LEAST THE FIRST PART OF FRI...BUT THIS FEATURE
WILL BE LOCATED MAINLY W OF THE WATERS. SE TO ESE WINDS ON FRI WILL
BACK TO A MORE EASTERLY DIRECTION ON SAT. WIND SPEEDS ARE NOT
EXPECTED TO EXCEED 15 KT. AN ESE SWELL IS EXPECTED TO INCREASE
THROUGH THE PERIOD. THE SWELL WILL LENGTHEN FROM 7 SECONDS TO 9
SECONDS. THIS SWELL WILL ALLOW OVERALL SEAS TO BUILD FROM 2 TO 3 FT
FRI TO 3 TO 4 FT SAT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...EXPECT SOUTHERLY RETURN FLOW AROUND
BERMUDA HIGH THROUGH THE PERIOD. AS HIGH BECOMES SUPPRESSED A BIT
FURTHER SOUTH MON INTO TUES EXPECT S-SE WINDS TO VEER AROUND
BECOMING MORE S TO SW. OVERALL SPEEDS SHOULD BE AROUND 10 KTS
INCREASING SLIGHTLY AND BECOMING A BIT GUSTY EACH AFTERNOONS IN
SEA BREEZE. THIS PERSISTENT SOUTHERLY PUSH WILL KEEP SEAS AROUND 2
TO 4 FT THROUGH THE PERIOD. WNA SHOWS LONGER PERIOD 9 TO 10 SECOND
E-SE SWELL MIXING WITH LOCALLY DRIVEN WIND WAVES THROUGH THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...MJC/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
740 PM EDT THU JUL 12 2012
.SYNOPSIS...
A WEAK FRONT STALLED TO OUR NORTH PLUS A HUMID TROPICAL AIRMASS WILL
BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS BERMUDA HIGH
PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...A STATIONARY FRONT ACROSS THE CAROLINAS IS
OUTLINED ALONG A WEAK PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST
TO NORTHEAST WINDS. THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE
NC ACROSS SOUTHERN DUPLIN AND SAMPSON COUNTIES TO NEAR
FAYETTEVILLE...THEN SOUTHWESTWARD THROUGH BENNETTSVILLE AND
DARLINGTON TO JUST NORTH OF COLUMBIA. THUNDERSTORMS IGNITED TODAY
ALONG THIS FRONT AND ALSO ALONG THE SEABREEZE BOUNDARY...PUSHED
SLOWLY NORTHWESTWARD BY THE 0-6 KM MEAN WIND. SURFACE-BASED
INSTABILITY HAS BEEN NEARLY EXHAUSTED NOW WITH RADAR PRECIPITATION
ESTIMATES SHOWING AT LEAST 80 PERCENT OF OUR FORECAST AREA RECEIVED
SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY..IT WILL TURN DECIDEDLY DRIER AS WE MOVE FROM
FRI TO SAT WITH PRECIPITABLE WATER VALUES DROPPING FROM AROUND 2
INCHES FRI TO ONE AND A QUARTER INCHES DURING SAT.
BERMUDA RIDGE WILL EXPAND FROM THE WESTERN ATLANTIC AND ACROSS THE
EASTERN CAROLINAS THIS PERIOD...WITH A DEEP EASTERLY FLOW ENVELOPING
THE AREA. FRI WILL BEGIN WITH AN INVERTED TROUGH NEAR OR AT THE
COAST AND MOVING WESTWARD. THERE IS ALSO A SUBTLE FEATURE ALOFT
BEING DEPICTED BY THE MODELS...MOVING WESTWARD DURING FRI. THIS
COUPLED WITH THE SEABREEZE SHOULD BRING ANOTHER GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO COASTAL LOCATIONS DURING THE MORNING
WITH POPS INCREASING INLAND AS THESE FEATURES MOVE INLAND DURING THE
AFTERNOON WHILE LOWERING AT THE COAST. AT THIS TIME...WILL HOLD
COVERAGE AT SCATTERED ALTHOUGH LOCALLY...COVERAGE MAY BECOME
NUMEROUS. STORM MOTIONS AROUND 5 KT AND HIGH ATMOSPHERIC WATER
CONTENT SHOULD YIELD SLOW MOVING THUNDERSTORMS WITH HEAVY DOWNPOURS.
THIS MAY RESULT IN PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. EXAMINATION OF OTHER PARAMETERS INDICATE THE RISK FOR SEVERE
WEATHER IS OTHERWISE LOW AT THIS TIME.
SAT...DRIER AIR AND DEVELOPING CAP AROUND 8-10 KFT...WILL NOT BE AN
ENVIRONMENT CONDUCIVE FOR CONVECTION...EVEN ALONG THE SEABREEZE.
WILL CONFINE POPS TO SMALL CHANCE AT THIS TIME.
IT SHOULD BE NOTED THAT WITH THE DEVELOPING AND DEEPENING EASTERLY
FLOW...NOCTURNAL SHOWERS DEVELOPING ACROSS THE CLIMATOLOGICALLY
FAVORED WATERS MAY MOVE ONSHORE OVERNIGHT/EARLY MORNING HOURS AND
THIS SEEMS MOST PLAUSIBLE LATE FRI NIGHT AND SAT MORNING.
TEMPS WILL NOT DEVIATE MUCH FROM NORMAL VALUES FOR MID JULY...WITH
HIGHS AND LOWS GENERALLY STAYING WITHIN A DEG OR TWO OF NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...RETURN FLOW WILL CONTINUE AROUND BERMUDA
HIGH THROUGH THE PERIOD. LOCAL AREA WILL REMAIN ON THE WESTERN
PERIPHERY OF THE RIDGE WITH DEEPER S-SW RETURN FLOW THROUGH THE
LOW LEVELS OF THE ATMOSPHERE. A MINOR PERTURBATION IN THE FLOW MAY
RIDE THROUGH FROM THE EAST SUN INTO MON WITH INCREASED CHC OF
PCP...BUT BASICALLY EXPECT DRIER MORE SUBSIDENT CONDITIONS THROUGH
THE MID TO UPPER LEVELS THROUGH MOST OF THE PERIOD. OVERALL EXPECT
MORE TYPICAL SUMMERTIME WEATHER WITH CU BUILDING EACH AFTERNOON
AND CONVECTION POSSIBLE MAINLY ALONG SEA BREEZE AND FURTHER INLAND
ALONG PIEDMONT TROUGH.
AS RIDGE GETS SUPPRESSED A BIT FURTHER SOUTH HEADING LATE
MON THROUGH MID WEEK...A BETTER WESTERLY COMPONENT TO THE FLOW WILL
DEVELOP THROUGH THE LOW LEVELS. THIS SHOULD HELP TO PRODUCE A SLIGHT
WARMING TREND. MAX TEMPS WILL REACH BETWEEN 90 AND 95 MOST DAYS AND
REMAIN IN THE 70S OVERNIGHT.
AT THE VERY END OF PERIOD MAY SEE NORTHERN STREAM SHORTWAVE DIG DOWN
INTO THE CAROLINAS AND PUSH A FRONT THROUGH LATE THURS INTO FRI.
THIS WOULD PRODUCE MORE WIDESPREAD CONVECTION BUT TOO FAR OUT TO
FEEL CONFIDENT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...PERIODS OF MVFR OVERNIGHT DUE FOG/STRATUS LATE TONIGHT
INTO EARLY FRIDAY MORNING. OTHERWISE EXPECT VFR...WITH AFTERNOON
CONVECTION POSSIBLE.
CURRENT RADAR IMAGERY DEPICTS SHOWERS AFFECTING THE INLAND
SITES...GRADUALLY PROGRESSING NORTHWARD. FCST GUIDANCE SUGGESTS
ADDITIONAL SHRA TO DEVELOP LATE OVERNIGHT OFFSHORE...MOVING ONSHORE
AFTER MIDNIGHT. FOR NOW HAVE INTRODUCED VCSH. GIVEN ABUNDANT
RAINFALL IN SOME LOCATIONS AND LIGHT AND VARIABLE WINDS...ANTICIPATE
MVFR FOG...WITH LOW CIGS DUE TO STRATUS POSSIBLE AS WELL BY EARLY
MORNING. EXPECT ANY LINGERING FOG TO CLEAR OUT BY MORNING..WITH
GUIDANCE DEPICTING CIGS AROUND 2500-3000FT AND ISOLATED SHRA FOR
MOST OF THE EARLY AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED
SHRA/TSRA ANTICIPATED FRIDAY AFTERNOON...WITH SOUTH-SOUTHEAST
WINDS AOB 10 KTS AND GUSTS POSSIBLE IN ANY STORM. ANTICIPATE STORMS
TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 7230 PM THURSDAY...A WEAK FRONT STALLED ACROSS THE INLAND
CAROLINAS HELPED FOCUS SHOWER AND THUNDERSTORM ACTIVITY THERE THIS
AFTERNOON. ACROSS THE COASTAL WATERS A SOUTHEAST WIND AROUND 10 KT
WILL CONTINUE THROUGH THE NIGHT. AS IS TYPICAL IN THESE TROPICAL
AIRMASSES SCATTERED SHOWERS AND EVEN A FEW THUNDERSTORMS MAY DEVELOP
ACROSS THE COASTAL WATERS OVERNIGHT IN THIS WARM AND HUMID REGIME.
ACTIVITY SHOULD GENERALLY DRIFT TOWARD THE NORTH-NORTHWEST AND MAY
BEGIN TO REACH THE BEACHES AFTER 3 AM ACCORDING TO THE LATEST
RAPID-UPDATE HRRR COMPUTER MODEL. ALTHOUGH SEVERE WEATHER IS NOT
EXPECTED BRIEFLY HEAVY RAINFALL AND THE POTENTIAL OF WATERSPOUTS
WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...HIGH PRESSURE WILL DOMINATE THE MARINE
ENVIRONMENT. A WEAK INVERTED TROUGH IS EXPECTED TO DEVELOP AND
PERSIST THROUGH AT LEAST THE FIRST PART OF FRI...BUT THIS FEATURE
WILL BE LOCATED MAINLY W OF THE WATERS. SE TO ESE WINDS ON FRI WILL
BACK TO A MORE EASTERLY DIRECTION ON SAT. WIND SPEEDS ARE NOT
EXPECTED TO EXCEED 15 KT. AN ESE SWELL IS EXPECTED TO INCREASE
THROUGH THE PERIOD. THE SWELL WILL LENGTHEN FROM 7 SECONDS TO 9
SECONDS. THIS SWELL WILL ALLOW OVERALL SEAS TO BUILD FROM 2 TO 3 FT
FRI TO 3 TO 4 FT SAT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...EXPECT SOUTHERLY RETURN FLOW AROUND
BERMUDA HIGH THROUGH THE PERIOD. AS HIGH BECOMES SUPPRESSED A BIT
FURTHER SOUTH MON INTO TUES EXPECT S-SE WINDS TO VEER AROUND
BECOMING MORE S TO SW. OVERALL SPEEDS SHOULD BE AROUND 10 KTS
INCREASING SLIGHTLY AND BECOMING A BIT GUSTY EACH AFTERNOONS IN
SEA BREEZE. THIS PERSISTENT SOUTHERLY PUSH WILL KEEP SEAS AROUND 2
TO 4 FT THROUGH THE PERIOD. WNA SHOWS LONGER PERIOD 9 TO 10 SECOND
E-SE SWELL MIXING WITH LOCALLY DRIVEN WIND WAVES THROUGH THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...MJC/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
251 AM EDT WED JUL 11 2012
.SYNOPSIS...
A VERY MOIST AIR MASS AND WEAK SURFACE FRONT WILL PERSIST OVER
THE CAROLINAS THROUGH MID WEEK... BRINGING PERIODS OF SHOWERS AND
THUNDERSTORMS EACH DAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 1018 PM TUESDAY...
WEAK CONVERGENCE ALONG A STALLED 850-700MB BOUNDARY DRAPED
WEST-TO-EAST ACROSS THE NORTHERN COUNTIES COUPLED WITH AN AREA OF
UPPER DIVERGENCE SUPPLIED BY A 130KT JET CROSSING NEW ENGLAND WILL
INTERACT WITH A MOIST AIR MASS (PRECIP WATER VALUES 1.8 NW PIEDMONT
TO 2.1 INCHES SOUTHERN COASTAL PLAIN) TO MAINTAIN SCATTERED SHOWERS
AND ISOLATED THUNDER THROUGH THE REMAINDER OF THE NIGHT. 22Z RUN OF
THE HRRR AS WELL AS THE 12Z SPC WRF SUGGEST SHOWERS GRADUALLY
DIMINISHING NEXT FEW HOURS ACROSS THE SOUTH. AFTER MIDNIGHT...SHOWER
COVERAGE EXPECTED TO INCREASE ACROSS THE NORTH AND LINGER INTO EARLY
MORNING HOURS OF WEDNESDAY. AM A BIT CONCERNED THAT COULD SEE
LOCALLY HEAVY RAINFALL IN A FEW SPOTS AS DEEP SW-W FLOW WILL CAUSE
SHOWERS TO TRAIN OVER THE SAME LOCATION. HOWEVER CONFIDENCE NOT HIGH
ENOUGH TO WARRANT A FLASH FLOOD WATCH AS BELIEVE SUCH OCCURRENCES
WILL BE LIMITED IN NUMBER.
MIN TEMPS IN THE UPPER 60S TO LOWER 70S.
WEDNESDAY/WEDNESDAY NIGHT...CENTRAL NORTH CAROLINA REMAINS IN A
REGION OF WEAK SOUTHWESTERLY FLOW AT LOW AND MID LEVELS ON WEDNESDAY
AND WEDNESDAY NIGHT. THE STALLED SURFACE TROUGH/DECAYING DIFFUSE
FRONT REMAINS IN PLACE ACROSS EASTERN AND CENTRAL NC DURING THE
PERIOD WITH A RATHER MOIST AIR MASS AS NOTED BY PRECIPITABLE WATER
VALUES THAT RANGE NEAR 1.8 INCHES ACROSS THE SOUTHERN COASTAL PLAIN
AND SANDHILLS AREA TO 1.5 INCHES ACROSS THE FAR NORTHERN PIEDMONT
NEAR THE VIRGINIA BORDER. BOTH THE NAM/GFS INDICATE A SHEAR AXIS
WILL PERSIST ACROSS FAR WESTERN NC AND NEAR THE VA/NC BORDER DURING
THE PERIOD. WITH THIS IN MIND...WILL MAKE ONLY MINOR CHANGES TO
ONGOING FORECAST WHICH HIGHLIGHTS THE GREATEST PRECIPITATION CHANCES
DURING THE AFTERNOON AND EARLY EVENING...ESPECIALLY ACROSS THE
SOUTHERN HALF OF THE CWA. LIMITED INSTABILITY SHOULD KEEP THE SEVERE
WEATHER THREAT LIMITED BUT THE 12Z NAM NOTED SOMEWHAT STRONGER BULK
SHEAR VALUES OF AROUND 15-25 KTS ON WEDNESDAY AFTERNOON WHICH COULD
SUPPORT STORM ORGANIZATION. HIGH TEMPERATURES ON WEDNESDAY WILL BE
BELOW TO NEAR NORMAL AND RANGE FROM 83-88 WHILE LOWS WEDNESDAY NIGHT
SHOULD FALL TO AROUND 70 DEGREES. -BLAES
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 245 AM WEDNESDAY...
OVERALL PATTERN DOES NOT CHANGE TOO MUCH BY THURSDAY...WITH THE
BROAD MID LEVEL TROUGH AXIS STILL TO OUR WEST AND A WEAK SURFACE
FRONT/TROUGH NEAR THE REGION. MODELS ARE NOW IN DECENT AGREEMENT
WITH REGARDS TO A SURFACE WAVE MOVING ALONG THE AFOREMENTIONED
BOUNDARY...WITH THE NAM NOW ALSO MOVING THE WAVE OUT TO SEA AND
THEREFORE NOT DRAWING AS MUCH DRY AIR INTO THE REGION. ALL MODELS
SHOW SOME DRIER AIR MOVING INTO THE NORTHEASTERN PORTIONS OF THE
FORECAST AREA BEHIND THE DEPARTING LOW...THEREFORE WILL TREND POPS
FROM CHANCE ACROSS THE NORTHEAST TO LIKELY FURTHER SOUTH AND WEST.
WITH REGARDS TO ANY SEVERE THREAT...THE DEEP LAYER FLOW...SHEAR AND
MID LEVEL LAPSE RATES ARE ALL PROGGED TO BE RATHER WEAK...THEREFORE
AM NOT EXPECTING MUCH IN THE WAY ORGANIZATION. HOWEVER...CANNOT RULE
OUT A FEW ISOLATED STRONG TO SEVERE STORMS...WITH THE MAIN THREAT
BEING DAMAGING DOWNBURST WINDS...AS CAPE VALUES ARE PROGGED TO BE ON
THE ORDER OF 800-1200 J/KG...HIGHEST ACROSS THE SOUTH AND EAST.
NEVERTHELESS...THE PRIMARY CONCERN WILL CONTINUE TO BE LOCALLY HEAVY
RAINFALL. HIGH TEMPS WILL REMAIN BELOW NORMAL...GENERALLY MID TO
UPPER 80S DUE TO THE CONSIDERABLE CLOUD COVER AND ABOVE NORMAL
PRECIP CHANCES...WHILE OVERNIGHT LOWS ARE EXPECTED TO BE IN THE
UPPER 60S/LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 245 AM WEDNESDAY...
BY THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND...UPPER LEVEL
RIDGING WILL GRADUALLY BUILD BACK TO THE WEST FROM THE ATLANTIC AND
INTO THE CAROLINAS. THIS WILL RESULT IN A GRADUAL DOWNWARD TREND IN
PRECIP CHANCES AREAWIDE THROUGH MONDAY (WITH SUNDAY AND MONDAY
LOOKING TO BE MOSTLY DRY) AND THE BEST CHANCES EACH DAY OCCURRING
ACROSS THE WESTERN PORTIONS OF THE FORECAST AREA AS THE EAST WILL
SEE MORE INFLUENCE FROM THE UPPER RIDGING AS IT BUILDS IN. THEN BY
LATE MONDAY/EARLY TUESDAY...ANOTHER MID LEVEL TROUGH IS EXPECTED TO
APPROACH THE AREA...RESULTING IN INCREASING PRECIP CHANCES FOR
TUESDAY. WITH INCREASING HEIGHTS ALOFT AND MORE IN THE WAY OF
SUNSHINE EXPECTED...HIGH TEMPS WILL BEGIN TO TREND BACK TO ABOVE
NORMAL...WITH AT LEAST LOW 90S EXPECTED BY THE END OF THE PERIOD.
OVERNIGHT LOWS WILL REMAIN IN THE UPPER 60S/LOWER 70S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM WEDNESDAY...
SCATTERED SHOWERS AND STORMS CONTINUE THIS MORNING...MOST NUMEROUS
FROM THE TRIAD SOUTH TOWARD THE SOUTHERN PIEDMONT. BASED ON CURRENT
RADAR TRENDS...THE HEAVY SHOWERS AND STORMS SHOULD REMAIN SOUTH OF
KGSO AND KINT OVER THE NEXT FEW HOURS. CEILINGS SHOULD BEGIN TO
LOWER AT MOST LOCATIONS...IF THEY HAVE NOT ALREADY...TO MVFR AND
IFR. VSBYS WILL ALSO BE LOWER IN SOME AREAS...PARTICULARLY WHERE
HEAVIER RAIN HAS FALLEN IN THE PAST 6 TO 9 HOURS.
HOWEVER...CONFIDENCE IN HOW LOW CEILINGS/VSBYS WILL GET AT
INDIVIDUALLY LOCATIONS THROUGH 12Z IS LOW.
MOST OF THE SHOWERS AND STORMS ARE EXPECTED TO BE ACROSS THE
SOUTHERN PORTIONS OF NC TODAY...IN CLOSER PROXIMITY TO A WEAK AND
NEARLY STATIONARY FRONT. COVERAGE WILL INCREASE DURING THE
AFTERNOON...DURING WHICH TIME BRIEF HEAVY DOWNPOURS...GUSTY WINDS
AND LOW CEILINGS/VSBYS WILL BE POSSIBLE.
THE UNSETTLED WEATHER PATTERN IS EXPECTED TO PERSIST THROUGH
THURSDAY WITH PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS ALONG
WITH EXTENDED PERIODS OF SUB VFR CEILINGS. BY THE WEEKEND...THE
OCCURRENCE OF PROLONGED STRETCHES OF SUB VFR CEILINGS AS WELL AS
SCATTERED CONVECTION WILL BEGIN TO DECREASE AS AN AREA OF HIGH
PRESSURE BEGINS TO EXERT ITS INFLUENCE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...WSS/BLAES
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...WSS/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 AM EDT WED JUL 11 2012
.SYNOPSIS...
A VERY MOIST AIR MASS AND WEAK SURFACE FRONT WILL PERSIST OVER
THE CAROLINAS THROUGH MID WEEK... BRINGING PERIODS OF SHOWERS AND
THUNDERSTORMS EACH DAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH THE OVERNIGHT/...
AS OF 1018 PM TUESDAY...
WEAK CONVERGENCE ALONG A STALLED 850-700MB BOUNDARY DRAPED
WEST-TO-EAST ACROSS THE NORTHERN COUNTIES COUPLED WITH AN AREA OF
UPPER DIVERGENCE SUPPLIED BY A 130KT JET CROSSING NEW ENGLAND WILL
INTERACT WITH A MOIST AIR MASS (PRECIP WATER VALUES 1.8 NW PIEDMONT
TO 2.1 INCHES SOUTHERN COASTAL PLAIN) TO MAINTAIN SCATTERED SHOWERS
AND ISOLATED THUNDER THROUGH THE REMAINDER OF THE NIGHT. 22Z RUN OF
THE HRRR AS WELL AS THE 12Z SPC WRF SUGGEST SHOWERS GRADUALLY
DIMINISHING NEXT FEW HOURS ACROSS THE SOUTH. AFTER MIDNIGHT...SHOWER
COVERAGE EXPECTED TO INCREASE ACROSS THE NORTH AND LINGER INTO EARLY
MORNING HOURS OF WEDNESDAY. AM A BIT CONCERNED THAT COULD SEE
LOCALLY HEAVY RAINFALL IN A FEW SPOTS AS DEEP SW-W FLOW WILL CAUSE
SHOWERS TO TRAIN OVER THE SAME LOCATION. HOWEVER CONFIDENCE NOT HIGH
ENOUGH TO WARRANT A FLASH FLOOD WATCH AS BELIEVE SUCH OCCURRENCES
WILL BE LIMITED IN NUMBER.
MIN TEMPS IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 310 PM TUESDAY...
CENTRAL NORTH CAROLINA REMAINS IN A REGION OF WEAK SOUTHWESTERLY
FLOW AT LOW AND MID LEVELS ON WEDNESDAY AND WEDNESDAY NIGHT. THE
STALLED SURFACE TROUGH/DECAYING DIFFUSE FRONT REMAINS IN PLACE
ACROSS EASTERN AND CENTRAL NC DURING THE PERIOD WITH A RATHER
MOIST AIR MASS AS NOTED BY PRECIPITABLE WATER VALUES THAT RANGE
NEAR 1.8 INCHES ACROSS THE SOUTHERN COASTAL PLAIN AND SANDHILLS
AREA TO 1.5 INCHES ACROSS THE FAR NORTHERN PIEDMONT NEAR THE
VIRGINIA BORDER. BOTH THE NAM/GFS INDICATE A SHEAR AXIS WILL
PERSIST ACROSS FAR WESTERN NC AND NEAR THE VA/NC BORDER DURING THE
PERIOD. WITH THIS IN MIND...WILL MAKE ONLY MINOR CHANGES TO
ONGOING FORECAST WHICH HIGHLIGHTS THE GREATEST PRECIPITATION
CHANCES DURING THE AFTERNOON AND EARLY EVENING...ESPECIALLY ACROSS
THE SOUTHERN HALF OF THE CWA. LIMITED INSTABILITY SHOULD KEEP THE
SEVERE WEATHER THREAT LIMITED BUT THE 12Z NAM NOTED SOMEWHAT
STRONGER BULK SHEAR VALUES OF AROUND 15-25 KTS ON WEDNESDAY
AFTERNOON WHICH COULD SUPPORT STORM ORGANIZATION. HIGH
TEMPERATURES ON WEDNESDAY WILL BE BELOW TO NEAR NORMAL AND RANGE
FROM 83-88 WHILE LOWS WEDNESDAY NIGHT SHOULD FALL TO AROUND 70
DEGREES. -BLAES
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 215 PM...
BROAD UPPER LEVEL HIGH PRESSURE IS FORECAST TO EXTEND OVER THE
ATLANTIC COASTLINE OF THE SOUTHEAST STATES THURSDAY MORNING... WITH
A BROAD WEAK TROUGH OVER THE MISSISSIPPI VALLEY. THE ATLANTIC HIGH
SLOWLY EXTENDED FURTHER INLAND FOR FRIDAY AND PERSISTS OVER THE
SOUTHEAST FOR THE REMAINDER OF THE FORECAST PERIOD. AT THE SURFACE A
WEAK TROUGH IS FORECAST JUST INLAND OVER THE COASTAL PLAIN FOR
THURSDAY AND FRIDAY BEFORE DISSIPATING IN THE WAKE OF SOUTH TO
SOUTHEAST FLOW AROUND AN ATLANTIC HIGH PRESSURE SYSTEM. WEAK SURFACE
TROUGHING RETURNS TO THE PIEDMONT FOR THE BEGINNING OF THE WORK
WEEK.
LOW LEVEL FORCING FOR CONVECTION THURSDAY MOSTLY ABSENT OTHER THAN
DAYTIME HEATING EXCEPT AS NOTED BELOW. PRECIPITABLE WATERS REMAIN
HIGH AT AROUND TWO INCHES. HIGHEST POPS SOUTHEAST (70 PERCENT) WHERE
SOUTHEAST FLOW POTENTIALLY FRICTIONALLY CONVERGENT... OR WITH A
SEABREEZE... DROPPING TO FIFTY PERCENT NORTH. CONVECTION WILL WANE
IN THE LATE EVENING... WITH SOME SHOWERS PERHAPS SURVIVING TO DAWN.
MINIMAL CHANGES TO THE ABOVE SCENARIO FOR FRIDAY... SO A SIMILAR
FORECAST.
THE AIR MASS DRYS SLIGHTLY SATURDAY AS WINDS SHIFT TOWARD SOUTH AND
OFFSHORE HIGH PRESSURE BECOMES MORE DOMINATE. AFTERNOON RAIN CHANCES
30 PERCENT THOUGH SLIGHTLY FAVORING THE SOUTHEAST. AS THE HIGH
FURTHER EXERTS ITS INFLUENCE SUNDAY AND MONDAY... AFTERNOON RAIN
CHANCES FALL TO ONE IN SEVEN.
WITH A SURFACE TROUGH ESTABLISHING ITSELF OVER THE PIEDMONT FOR THE
EARLY WORK WEEK... AND A BROAD UPPER LEVEL TROUGH EXTENDING SOUTH...
WILL INCREASE RAIN CHANCES TO THIRTY PERCENT NORTH AND SLIGHT
CHANCES SOUTH.
A WARMING TREND IN AFTERNOON HIGH TEMPERATURES AS MOISTURE AND
RAIN CHANCES BEGIN TO DECREASE. HIGH TEMPERATURES IN THE MID 80S
THURSDAY AND FRIDAY... 85 TO 90 SATURDAY... AND UPPER 80S TO LOWER
90S SUNDAY INTO TUESDAY. OVERNIGHT LOWS UPPER 60S TO LOWER 70S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM WEDNESDAY...
SCATTERED SHOWERS AND STORMS CONTINUE THIS MORNING...MOST NUMEROUS
FROM THE TRIAD SOUTH TOWARD THE SOUTHERN PIEDMONT. BASED ON CURRENT
RADAR TRENDS...THE HEAVY SHOWERS AND STORMS SHOULD REMAIN SOUTH OF
KGSO AND KINT OVER THE NEXT FEW HOURS. CEILINGS SHOULD BEGIN TO
LOWER AT MOST LOCATIONS...IF THEY HAVE NOT ALREADY...TO MVFR AND
IFR. VSBYS WILL ALSO BE LOWER IN SOME AREAS...PARTICULARLY WHERE
HEAVIER RAIN HAS FALLEN IN THE PAST 6 TO 9 HOURS.
HOWEVER...CONFIDENCE IN HOW LOW CEILINGS/VSBYS WILL GET AT
INDIVIDUALLY LOCATIONS THROUGH 12Z IS LOW.
MOST OF THE SHOWERS AND STORMS ARE EXPECTED TO BE ACROSS THE
SOUTHERN PORTIONS OF NC TODAY...IN CLOSER PROXIMITY TO A WEAK AND
NEARLY STATIONARY FRONT. COVERAGE WILL INCREASE DURING THE
AFTERNOON...DURING WHICH TIME BRIEF HEAVY DOWNPOURS...GUSTY WINDS
AND LOW CEILINGS/VSBYS WILL BE POSSIBLE.
THE UNSETTLED WEATHER PATTERN IS EXPECTED TO PERSIST THROUGH
THURSDAY WITH PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS ALONG
WITH EXTENDED PERIODS OF SUB VFR CEILINGS. BY THE WEEKEND...THE
OCCURRENCE OF PROLONGED STRETCHES OF SUB VFR CEILINGS AS WELL AS
SCATTERED CONVECTION WILL BEGIN TO DECREASE AS AN AREA OF HIGH
PRESSURE BEGINS TO EXERT ITS INFLUENCE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...WSS
SHORT TERM...BLAES
LONG TERM...
AVIATION...WSS/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
642 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE GREAT LAKES AND NORTHERN OHIO
VALLEY TODAY...LIMITING ANY CHANCES OF RAIN THROUGH EARLY THURSDAY
TO AREAS NEAR AND SOUTH OF THE OHIO RIVER. AN APPROACHING TROUGH OF
LOW PRESSURE WILL ALLOW MOISTURE OVER THE SOUTHEASTERN STATES TO
MOVE NORTH INTO THE OHIO VALLEY...BRINGING PERIODS OF RAIN AND
THUNDERSTORMS FROM LATE THURSDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PATCHES OF ALTOCUMULUS ARE LOCATED ALONG AN EAST-WEST LINE FROM
NORTH OF ST LOUIS TO THE NORTHERN PANHANDLE OF WEST VIRGINIA. THIS
IS WELL NORTH OF THE LOCATION OF THE MAIN BOUNDARY THAT IS HOLDING
THE MOISTURE OVER THE SOUTHERN STATES. THE RAP IS HANDLING THESE
CLOUDS (AND VERY LIGHT SHOWERS) FAIRLY WELL...SHOWING AN AREA OF
850MB CONVERGENCE AND ENHANCED RH. THIS MOISTURE MAY NOT DISSIPATE
COMPLETELY...LEADING TO THE POSSIBILITY OF A FEW MORE CLOUDS TODAY
THAN YESTERDAY.
ASIDE FROM THIS...THE AIR MASS HAS NOT CHANGED TOO APPRECIABLY
OVER THE LAST 24 HOURS. WITH THE EXTRA CLOUDS...THE HIGH
TEMPERATURE FORECAST WILL BE SLIGHTLY LOWER THAN THE OBSERVED
TEMPS YESTERDAY...BUT STILL A COUPLE DEGREES ABOVE THE PREVIOUS
FORECAST AND CLOSE TO NAM/MET NUMBERS.
DIURNAL HEATING WILL ALLOW SOME INSTABILITY TO BUILD INTO THE FAR
SOUTH AND SOUTHEAST PORTIONS OF THE CWA. WITH THE HIGHER-RES
MODELS INDICATING SOME POTENTIAL FOR CONVECTIVE DEVELOPMENT...A
SLIGHT CHANCE OF PRECIPITATION HAS BEEN INCLUDED FOR A FEW HOURS
ALONG AND SOUTH OF AN OWENTON-TO-LUCASVILLE LINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE FORECAST FOCUS IN THE SHORT TERM WILL BE ON THE MOISTURE
MOVING NORTH OUT OF THE DEEP SOUTH. AS AN INVERTED SURFACE TROUGH
STRETCHES THROUGH THE OHIO VALLEY AND UP TOWARD LAKE ERIE...AN
AREA OF MID-LEVEL TROUGHING IS EXPECTED TO DEVELOP OVER THE
MISSISSIPPI VALLEY. MOISTURE WILL BEGIN PUSHING NORTH LATE ON
THURSDAY...WITH THE HIGHEST PRECIPITATION CHANCES EXPECTED FRIDAY
DURING THE PEAK DIURNAL CYCLE. CALLING THIS SYSTEM A WARM FRONT
MAY BE COUNTER-INTUITIVE...SINCE MAX TEMPS ARE EXPECTED TO DROP AS
THE MOISTURE ESTABLISHES ITSELF OVER THE AREA.
WHILE THE GENERAL EXPECTATIONS FOR THIS SYSTEM ARE PRETTY WELL
FIGURED...THE DETAILS ON WHEN THE MOISTURE SURGE ARRIVES AND THE
LOCATION OF THE HIGHEST CHANCES OF RAINFALL ARE NOT BEING HANDLED
CONSISTENTLY FROM MODEL TO MODEL OR RUN TO RUN. THERE REMAINS
ENOUGH SUPPORT ON FRIDAY EVENING TO USE LIKELY POPS ACROSS THE
SOUTHWESTERN CWA...BUT OTHERWISE CHANCE POPS WILL BE USED FOR MUCH
OF THURSDAY NIGHT THROUGH THE WEEKEND. MODEL SIGNALS FOR THE
POSSIBILITY OF SOME AREAS OF HEAVY RAIN HAVE INCREASED SOMEWHAT IN
THE LATEST RUNS...ALTHOUGH THIS THREAT WILL STILL LIKELY BE A BIT
DEPENDENT ON THE LOCATION OF CONVECTION WITHIN THE OVERALL AREA OF
RAINFALL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE THREAT FOR THUNDERSTORMS WILL PERSIST THROUGH THE WEEKEND
INTO MONDAY AS THE LONG WAVE TROUGH MAKES ITS WAY SLOWLY
EAST...ENHANCED BY SHORT WAVE ENERGY FROM TIME TO TIME. A RETURN
TO DRIER WEATHER WILL BE POSSIBLE NEXT TUESDAY WHEN THE FLOW ALOFT
IS FORECAST TO BECOME ZONAL WHILE SURFACE HIGH PRESSURE BUILDS
OVER THE SOUTHEAST STATES.
TEMPERATURES WILL HOVER WITHIN A FEW DEGREES OF NORMAL WITH HIGHS IN
THE 80S. FRIDAY MAY BE THE COOLEST DAY OF THE PERIOD WITH HIGHS IN
THE LOWER 80S DUE TO WIDESPREAD CLOUDS AND NUMEROUS THUNDERSTORMS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AN ELONGATED WEST TO EAST RIDGE OF HIGH PRESSURE FROM THE GREAT
LAKES TO NEW ENGLAND WILL HOLD STEADY THROUGH THE TAF PERIOD. A
SURFACE INVERTED TROF EXTENDING FROM THE BOOT HEEL OF MISSOURI
NORTHEAST TO NORTHERN WEST VIRGINIA WILL SLOWLY ROTATE NORTHWEST
THROUGH THE TAF PERIOD. MEANWHILE...A WEAK EMBEDDED DISTURBANCE
WILL PUSH SOUTHEAST ACRS THE REGION IN A NORTHWEST FLOW ALOFT. ALL
IN ALL...TODAY WILL LOOK LIKE A CARBON COPY OF TUESDAY WITH HIGH
BASED CUMULUS EXPECTED. THE DIFFERENCE WILL BE THAT THE SFC
INVERTED TROF ALONG WITH THE WEAK DISTURBANCE ALOFT MAY POP A FEW
SHOWERS AND THUNDERSTORMS ALONG AND SOUTH OF THE OHIO RIVER. PLAN
ON KEEPING ALL TAFS DRY CONSIDERING THE COVERAGE OF CONVECTION.
ANY CONVECTION SHOULD DIMINISH THIS EVENING ONCE THE LOW LEVELS OF
THE ATMOSPHERE COOL. NORTHEAST TO EAST FLOW AROUND 10 KNOTS WILL
BECOME MORE EAST TO SOUTHEAST TOWARD 12Z THURSDAY.
OUTLOOK...THUNDERSTORMS POSSIBLE THURSDAY THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
419 AM EDT WED JUL 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE GREAT LAKES AND NORTHERN OHIO
VALLEY TODAY...LIMITING ANY CHANCES OF RAIN THROUGH EARLY THURSDAY
TO AREAS NEAR AND SOUTH OF THE OHIO RIVER. AN APPROACHING TROUGH OF
LOW PRESSURE WILL ALLOW MOISTURE OVER THE SOUTHEASTERN STATES TO
MOVE NORTH INTO THE OHIO VALLEY...BRINGING PERIODS OF RAIN AND
THUNDERSTORMS FROM LATE THURSDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PATCHES OF ALTOCUMULUS ARE LOCATED ALONG AN EAST-WEST LINE FROM
NORTH OF ST LOUIS TO THE NORTHERN PANHANDLE OF WEST VIRGINIA. THIS
IS WELL NORTH OF THE LOCATION OF THE MAIN BOUNDARY THAT IS HOLDING
THE MOISTURE OVER THE SOUTHERN STATES. THE RAP IS HANDLING THESE
CLOUDS (AND VERY LIGHT SHOWERS) FAIRLY WELL...SHOWING AN AREA OF
850MB CONVERGENCE AND ENHANCED RH. THIS MOISTURE MAY NOT DISSIPATE
COMPLETELY...LEADING TO THE POSSIBILITY OF A FEW MORE CLOUDS TODAY
THAN YESTERDAY.
ASIDE FROM THIS...THE AIR MASS HAS NOT CHANGED TOO APPRECIABLY
OVER THE LAST 24 HOURS. WITH THE EXTRA CLOUDS...THE HIGH
TEMPERATURE FORECAST WILL BE SLIGHTLY LOWER THAN THE OBSERVED
TEMPS YESTERDAY...BUT STILL A COUPLE DEGREES ABOVE THE PREVIOUS
FORECAST AND CLOSE TO NAM/MET NUMBERS.
DIURNAL HEATING WILL ALLOW SOME INSTABILITY TO BUILD INTO THE FAR
SOUTH AND SOUTHEAST PORTIONS OF THE CWA. WITH THE HIGHER-RES
MODELS INDICATING SOME POTENTIAL FOR CONVECTIVE DEVELOPMENT...A
SLIGHT CHANCE OF PRECIPITATION HAS BEEN INCLUDED FOR A FEW HOURS
ALONG AND SOUTH OF AN OWENTON-TO-LUCASVILLE LINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE FORECAST FOCUS IN THE SHORT TERM WILL BE ON THE MOISTURE
MOVING NORTH OUT OF THE DEEP SOUTH. AS AN INVERTED SURFACE TROUGH
STRETCHES THROUGH THE OHIO VALLEY AND UP TOWARD LAKE ERIE...AN
AREA OF MID-LEVEL TROUGHING IS EXPECTED TO DEVELOP OVER THE
MISSISSIPPI VALLEY. MOISTURE WILL BEGIN PUSHING NORTH LATE ON
THURSDAY...WITH THE HIGHEST PRECIPITATION CHANCES EXPECTED FRIDAY
DURING THE PEAK DIURNAL CYCLE. CALLING THIS SYSTEM A WARM FRONT
MAY BE COUNTER-INTUITIVE...SINCE MAX TEMPS ARE EXPECTED TO DROP AS
THE MOISTURE ESTABLISHES ITSELF OVER THE AREA.
WHILE THE GENERAL EXPECTATIONS FOR THIS SYSTEM ARE PRETTY WELL
FIGURED...THE DETAILS ON WHEN THE MOISTURE SURGE ARRIVES AND THE
LOCATION OF THE HIGHEST CHANCES OF RAINFALL ARE NOT BEING HANDLED
CONSISTENTLY FROM MODEL TO MODEL OR RUN TO RUN. THERE REMAINS
ENOUGH SUPPORT ON FRIDAY EVENING TO USE LIKELY POPS ACROSS THE
SOUTHWESTERN CWA...BUT OTHERWISE CHANCE POPS WILL BE USED FOR MUCH
OF THURSDAY NIGHT THROUGH THE WEEKEND. MODEL SIGNALS FOR THE
POSSIBILITY OF SOME AREAS OF HEAVY RAIN HAVE INCREASED SOMEWHAT IN
THE LATEST RUNS...ALTHOUGH THIS THREAT WILL STILL LIKELY BE A BIT
DEPENDENT ON THE LOCATION OF CONVECTION WITHIN THE OVERALL AREA OF
RAINFALL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE THREAT FOR THUNDERSTORMS WILL PERSIST THROUGH THE WEEKEND
INTO MONDAY AS THE LONG WAVE TROUGH MAKES ITS WAY SLOWLY
EAST...ENHANCED BY SHORT WAVE ENERGY FROM TIME TO TIME. A RETURN
TO DRIER WEATHER WILL BE POSSIBLE NEXT TUESDAY WHEN THE FLOW ALOFT
IS FORECAST TO BECOME ZONAL WHILE SURFACE HIGH PRESSURE BUILDS
OVER THE SOUTHEAST STATES.
TEMPERATURES WILL HOVER WITHIN A FEW DEGREES OF NORMAL WITH HIGHS IN
THE 80S. FRIDAY MAY BE THE COOLEST DAY OF THE PERIOD WITH HIGHS IN
THE LOWER 80S DUE TO WIDESPREAD CLOUDS AND NUMEROUS THUNDERSTORMS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AN ELONGATED WEST TO EAST RIDGE OF HIGH PRESSURE FROM THE GREAT
LAKES TO NEW ENGLAND WILL HOLD STEADY THROUGH THE TAF PERIOD. A
SURFACE INVERTED TROF EXTENDING FROM THE BOOT HEEL OF MISSOURI
NORTHEAST TO NORTHERN WEST VIRGINIA WILL SLOWLY ROTATE NORTHWEST
THROUGH THE TAF PERIOD. MEANWHILE...A WEAK EMBEDDED DISTURBANCE
WILL PUSH SOUTHEAST ACRS THE REGION IN A NORTHWEST FLOW ALOFT. ALL
IN ALL...TODAY WILL LOOK LIKE A CARBON COPY OF TUESDAY WITH HIGH
BASED CUMULUS EXPECTED. THE DIFFERENCE WILL BE THAT THE SFC
INVERTED TROF ALONG WITH THE WEAK DISTURBANCE ALOFT MAY POP A FEW
SHOWERS AND THUNDERSTORMS ALONG AND SOUTH OF THE OHIO RIVER. PLAN
ON KEEPING ALL TAFS DRY CONSIDERING THE COVERAGE OF CONVECTION.
ANY CONVECTION SHOULD DIMINISH THIS EVENING ONCE THE LOW LEVELS OF
THE ATMOSPHERE COOL. NORTHEAST TO EAST FLOW AROUND 10 KNOTS WILL
BECOME MORE EAST TO SOUTHEAST TOWARD 12Z THURSDAY.
OUTLOOK...THUNDERSTORMS POSSIBLE THURSDAY THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
907 PM CDT THU JUL 12 2012
.DISCUSSION...
RIVER FLOOD WARNINGS ONGOING FOR PORTIONS OF NW HARRIS COUNTY AND
MATAGORDA COUNTY..SEE APPROPRIATE FLSHGX FLOOD STATEMENTS...PART
OF NW HARRIS COUNTY RECEIVED 8.5 TO 10.3 INCHES OF RAIN IN THE
PAST 24 HOURS. ONE OF THE CYPRESS CREEK STREAM GAUGES WAS
REPORTING STAGE HEIGHTS REMINISCENT OF VALUES FROM TS ALLISON.
LATEST HRRR (WHICH HAS PERFORMED WELL THE PAST TWO NIGHTS) AND TX
TECH WRF REFLECTIVITY FIELD FORECASTS AGAIN SHOW SHRA/TSRA
DEVELOPING IN THE 07-08Z RANGE OVERNIGHT IN SE TX PARTICULARLY
CLOSE OR JUST UPSTREAM OF WORST HIT FLOODING TODAY. COVERAGE AND
RAINFALL INTENSITY DO NOT APPEAR TO BE AS LARGE AND INTENSE AS
LAST NIGHT BUT IS OF LITTLE CONSOLATION IF ADDITIONAL RAINS DO
FALL. THE MEAN 1000-700MB TROUGH HAS SHIFTED A BIT SOUTHEAST IN
THE PAST 24HRS AS DEPICTED BY RADAR/PROFILER LOOPS. AREA 00Z
SOUNDINGS ARE A TAD BIT DRIER...KLCH WAS 2.04 INCH LAST NIGHT AND
TONIGHT IS AROUND 1.85 INCH. BLENDED PWAT IMAGERY ON AWIPS2 ALSO A
TAD BIT DRIER...HENCE PREVIOUS SHIFTS OUTLOOK OF LESS INTENSIVE
AND LESS COVERAGE SEEMS GOOD. GIVEN THE PREDICTED RECURRENCE OF
LATE NIGHT RAINS JUST N AND NW OF METRO HOUSTON THESE MAY BEGIN TO
MOVE SW AS DEPICTED BY HRRR/TTECH WRF WITH ANOTHER AREA OF HVY
RAIN MAINLY EAST OF I45...SAY EASTERN 1/3 OF HARRIS..CHAMBERS AND
LIBERTY COUNTIES IN THE MORNING HOURS. BEARS WATCHING. NONETHELESS...CURRENT
OUTLINE OF FLASH FLOOD WATCH LOOKS GOOD FOR THE OVERNIGHT AND
MORNING HOURS.
OTHERWISE A FEW TWEAKS FOR TEMPERATURES AND SKY COVERAGE AS
POCKETS OF SUN APPEARED LATE IN THE AFTERNOON IN SE TX AND SENT
TEMPS INTO THE MID 80S IN A FEW LOCATIONS.
04
&&
.PREV DISCUSSION... /ISSUED 629 PM CDT THU JUL 12 2012/
AVIATION...
WITH THE UPPER LEVEL AXIS IN THE AREA MOVING LITTLE OVER THE NEXT DAY
OR SO...EXPECT TO SEE ANOTHER ROUND OF SHRA/TSRA DEVELOPMENT ACROSS
PORTIONS OF SOUTHEAST TEXAS OVERNIGHT THROUGH AROUND MIDDAY TOMORROW...
PERHAPS SIMILAR TO WHAT WAS OBSERVED ACROSS THE AREA TODAY. TAF SITES
COULD EXPERIENCE MVFR/IFR CEILINGS AND VISIBILITIES IN/NEAR THE STORMS
WITH MOSTLY/GENERALLY VFR CONDITIONS OTHERWISE. 42
PREV DISCUSSION... /ISSUED 406 PM CDT THU JUL 12 2012/
DISCUSSION...
THE LARGE AREA OF RAINFALL THAT AFFECTED THE SOUTHERN HALF OF THE
REGION THIS MORNING HAS LARGELY DISSIPATED OR MOVED OFFSHORE THIS
MORNING. ADDITIONAL PRECIPITATION HAS DEVELOPED ACROSS THE
NORTHERN PORTIONS OF THE REGION ALONG THE SURFACE FRONT BUT THIS
ACTIVITY IS MOVING TO THE WEST SOUTHWEST AND IS NOT EXPECTED TO
MOVE INTO THE AREAS AFFECTED THIS MORNING.
MAIN CONCERN FOR THIS FORECAST ISSUANCE REMAINS THE POTENTIAL FOR
A REPEAT EARLY MORNING HEAVY RAINFALL EVENT ACROSS THE SOUTHERN
PORTION OF THE REGION. ALL OF THE MODELS ARE HINTING AT
REDEVELOPMENT AFTER MIDNIGHT TONIGHT ACROSS PORTIONS OF SOUTHEAST
AND EAST TEXAS. THE NAM IS THE FARTHEST NORTH WITH THIS ACTIVITY
WHILE THE GFS AND ECMWF KEEP DEVELOPMENT CLOSER TO GALVESTON BAY.
THE 3KM TEXAS TECH WRF RUN THAT PERFORMED VERY WELL WITH THE
ACTIVITY TODAY IS THE MOST TROUBLING...WITH REDEVELOPMENT
OCCURRING ACROSS HARRIS COUNTY EARLY FRIDAY MORNING. ALTHOUGH IT
DOES APPEAR THAT THE AREAL EXTENT OF THE RAINFALL WILL BE LESS
TONIGHT ANY ADDITIONAL RAINFALL WOULD BE UNWELCOME ACROSS MUCH OF
THE REGION. WITH THIS IN MIND HAVE EXTENDED THE FLASH FLOOD WATCH
FOR MUCH OF THE REGION THROUGH MIDDAY ON FRIDAY.
NOT MANY CHANGES TO THE EXTENDED FORECAST. THE UPPER WEAKNESS WILL
REMAIN CLOSE TO THE REGION THROUGH THE WEEKEND ALLOWING FOR A
CONTINUATION OF THE CURRENT WET PATTERN. CONVECTION IS EXPECTED TO
SHIFT MORE TOWARDS A DIURNALLY DRIVEN PATTERN WITH SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING EACH AFTERNOON. THE UPPER
RIDGE WILL BEGIN TO REDEVELOP ACROSS THE CENTRAL PLAINS NEXT WEEK
WHICH SHOULD INCREASE TEMPS A BIT ACROSS THE REGION BUT STILL
ALLOW FOR SOME CONVECTION CLOSE TO THE COAST EACH AFTERNOON. 38
MARINE...
NO SIGNIFICANT CHANGES TO CURRENT FCST TRENDS. A WEAK SURFACE TROUGH
WILL KEEP A LIGHT WINDS IN PLACE THROUGH THE WEEKEND. THE LINGERING
UPPER LEVEL TROF WILL ALSO KEEP SCATTERED STORMS IN THE FCST THROUGH
THE END OF THE WEEK. BRIEF GUSTY WINDS/ELEVATED SEAS ARE POSSIBLE IN
AND NEAR THE STRONGER STORMS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 89 72 91 73 / 30 50 30 30 30
HOUSTON (IAH) 73 89 72 91 73 / 50 50 40 40 30
GALVESTON (GLS) 80 88 80 89 80 / 50 50 50 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...WALLER...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...04
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
356 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...TODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
342 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...ODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
333 AM CDT FRI JUL 13 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
&&
.SHORT TERM...ODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RUC
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE.
08
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT THROUGH TUESDAY WARMER AIR POURS BACK TO INTO THE
REGION AS UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS
LIKE WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY
WITH HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A
DRY FORECAST IS IN ORDER.
FOR WEDNESDAY AND THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WILL KEEP SOME LOW POPS GOING WEDNESDAY THROUGH THURSDAY...
BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE RANGE SINCE MODELS KEEP
MID LEVEL TEMPS ON THE WARM SIDE NEAR THE BOUNDARY. IF THE
GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH SETTING UP OVER THE
WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST LOW LEVEL FLOW OVER
THE AREA...TAKING THE EDGE OFF THE HEAT FOR THE END OF THE WEEK.
DLF
&&
.AVIATION...
ELEVATED CONVECTION HAS DEVELOPED IN RESPONSE TO AN UPPER LEVEL
DISTURBANCE. KCID IS BEING AFFECTED WITH KDBQ/KMLI POSSIBLY BEING
AFFECTED AS WELL. MVFR CONDITIONS THAT MAY BRIEFLY DROP TO IFR ARE
EXPECTED. ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO PERSIST
THROUGH 00Z/14 AND POSSIBLY BEYOND. WHEN TSRA OR VCTS IS NOT
AFFECTING A TAF SITE...VFR CONDITIONS ARE EXPECTED.
08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
321 AM CDT FRI JUL 13 2012
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
THE NAM AND GFS ARE A LITTLE MORE AGGRESSIVE IN SHOWING SOME MID
LEVEL ISENTROPIC LIFT THROUGH THE NIGHT AND ISOLATED PRECIP
SPREADING INTO NORTHEAST KS AS A WEAK DISTURBANCE MOVES THROUGH
SOUTHERN NEB. CONFIDENCE IN LOCATION AND COVERAGE IS LOW. HOWEVER
LATEST RUNS OF THE HRRR SUGGEST SCT TS MAY BE POSSIBLE ACROSS
NORTHEAST KS BEFORE 12Z. IN ANY CASE ODDS ARE THAT VFR CONDITIONS
WILL PREVAIL. IF STORMS DEVELOP THERE COULD BE A BRIEF 15 TO 30
MINUTE WINDOW OF REDUCED VSBY. WITH LOW CONFIDENCE AND LOW SKILL IN
FORECASTING CONVECTIVE DETAILS...WILL OPT TO KEEP A VFR FORECAST AND
MONITOR TRENDS FOR POSSIBLE ADDITION OF A TEMPO FOR MVFR VSBY AND
TS.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1045 PM MDT THU JUL 12 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 146 PM MDT THU JUL 12 2012
SURFACE TROUGH IS STARTING TO PUSH INTO THE WESTERN PORTION OF
THE AREA WITH A SHORTWAVE MOVING OVER THE TOP OF IT BEGINNING THIS
AFTERNOON. DECENT SURFACE CONVERGENCE ALONG IT WITH LITTLE TO NO
INHIBITION. SO DO EXPECT THUNDERSTORMS TO DEVELOP BUT HOW FAR EAST
TO TAKE THEM IS A QUESTION. STORM MOVEMENTS NEAR 15 KNOTS SO THEY
SHOULD MAKE SOME PROGRESS. EARLIER MODEL OUTPUT WAS NOT TOTALLY
EXCITED ABOUT GENERATING PRECIPITATION ACROSS CWA THROUGH TONIGHT.
HOWEVER...THE LATEST HRRR IS GENERATING SOME LIGHT QPF.
WITH THE AMOUNT OF INSTABILITY AND LIFT BELIEVE THERE IS ENOUGH
THERE TO HAVE A SLIGHT CHANCE THROUGH THE ENTIRE NIGHT. SO GRIDS
WERE ADJUSTED ACCORDINGLY THROUGH TONIGHT. WINDS LOOK TO BECOME
LIGHT AND CLOUDS DECREASE AFTER WHATEVER CONVECTION THERE IS IS
DONE. DEPENDING ON HOW LOW THE DEWPOINTS ARE...TEMPERATURES COULD
DROP A LITTLE...ESPECIALLY IN THE WEST. LOOK TO HAVE PLENTY OF SUN
TOMORROW WITH MODELS SHOWING A RATHER CHAOTIC WIND FIELD...MOSTLY
FROM AN EASTERLY DIRECTION. NAM 2M/NWP HAS BEEN DOING WELL IN THIS
HOT PATTERN AND THINK IT IS ON THE RIGHT TRACK. GFS STILL LOOKS TOO
MOIST AND COOL IN THE LOWER LEVELS. SO BASED ON THE NAM 2M/NWP AND
850 MB TEMPERATURE CONCENSUS...RAISED MAXES FOR FRIDAY TO NEAR 100
FOR MANY LOCATIONS. MUCH WARMER AND DRIER AT MID LEVELS LOOKS TO
KEEP IT DRY TOMORROW AS WELL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 240 PM MDT THU JUL 12 2012
AT THE START OF THE EXTENDED PERIOD...THE UPPER HIGH NOW OVER UTAH
WILL HAVE MIGRATED TO THE CO-NM AREA AS THE LARGE SCALE UPPER TROUGH
BECOMES ESTABLISHED IN THE WEST. THE UPPER HIGH WILL BE THE
DOMINANT PLAYER IN OUR WEATHER AS IT STALLS OVER THE CENTRAL PLAINS
EARLY NEXT WEEK. WITH WEAK FLOW ALOFT AND LACK OF SURFACE FEATURES
TO FOCUS CONVECTION...THUNDERSTORM POTENTIAL DURING THIS PERIOD WILL
BE ISOLATED AT BEST. BOTH THE GFS AND ECMWF SUGGEST THE POTENTIAL
FOR INCREASING THUNDERSTORM COVERAGE IN DAYS 6 AND 7 AS A CANADIAN
SURFACE HIGH BUILDS SOUTH AND STALLS CLOSE TO OUR FORECAST AREA. IF
THIS SCENARIO DOES UNFOLD THEN POPS IN THE FAR EXTENDED PERIODS WILL
NEED TO BE ADJUSTED UPWARD.
DAY-TO-DAY TEMPERATURE CHANGES ARE EXPECTED TO BE INSIGNIFICANT.
MODELS FORECAST 850 TEMPS AROUND 30-32C THROUGH THE PERIOD WHICH
WILL TRANSLATE TO HIGHS IN THE MID 90S TO NEAR 100 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1038 PM MDT THU JUL 12 2012
THE CURRENT RADAR TREND INDICATES THAT STORMS SHOULD MOVE PAST
KMCK PRIOR TO 06Z AND THE REST OF THE NIGHT SHOULD BE QUIET.
THE NAM HAS A GOOD HANDLE ON CURRENT ACTIVITY AND DOES NOT BRING
ANY STORMS INTO KGLD OVERNIGHT. THEREFORE EXPECT VFR CONDITIONS
AND LIGHT SOUTHEAST WIND FOR THE NEXT 24 HOURS AS HIGH PRESSURE
ALOFT CONTINUES OVER THE ROCKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1138 PM CDT THU JUL 12 2012
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE NAM AND GFS ARE A LITTLE MORE AGGRESSIVE IN SHOWING SOME MID
LEVEL ISENTROPIC LIFT THROUGH THE NIGHT AND ISOLATED PRECIP
SPREADING INTO NORTHEAST KS AS A WEAK DISTURBANCE MOVES THROUGH
SOUTHERN NEB. CONFIDENCE IN LOCATION AND COVERAGE IS LOW. HOWEVER
LATEST RUNS OF THE HRRR SUGGEST SCT TS MAY BE POSSIBLE ACROSS
NORTHEAST KS BEFORE 12Z. IN ANY CASE ODDS ARE THAT VFR CONDITIONS
WILL PREVAIL. IF STORMS DEVELOP THERE COULD BE A BRIEF 15 TO 30
MINUTE WINDOW OF REDUCED VSBY. WITH LOW CONFIDENCE AND LOW SKILL IN
FORECASTING CONVECTIVE DETAILS...WILL OPT TO KEEP A VFR FORECAST AND
MONITOR TRENDS FOR POSSIBLE ADDITION OF A TEMPO FOR MVFR VSBY AND
TS.
WOLTERS
&&
.PREV DISCUSSION.../ISSUED 341 PM CDT THU JUL 12 2012/
SHORT TERM - THROUGH FRIDAY...ISOLATED THUNDERSTORMS HAVE
DEVELOPED IN THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON
IN A ZONE OF WEAK LOW LEVEL CONVERGENT FLOW WITH A HINT OF ASCENT
ALOFT COURTESY OF A VERY WEAK SHORT WAVE TROUGH. INSTABILITY WAS
ON THE ORDER OF 1000 TO 2000 J/KG...AND DEEP LAYER SHEAR IS ON THE
ORDER OF 10 KTS SO THE END RESULT IS A VERY PULSE-LIKE STORM MODE
WITH CELLS QUICK TO GO UP AND QUICK TO COLLAPSE. THERE IS A RATHER
DEEP LAYER OF DRY ADIABATIC LAPSE RATES IN THE LOW LEVELS SO THE
STRONGER STORMS HAVE PUT OUT SOME WIND GUSTS IN THE 40 TO 50 MPH
RANGE. THIS ISOLATED ACTIVITY SHOULD CONTINUE THROUGH MID TO LATE
AFTERNOON WITH A GRADUAL DECREASING TREND LIKELY AS OUTFLOW
STABILIZES THE BOUNDARY LAYER BIT BY BIT.
THERE IS SOME POTENTIAL FOR REDEVELOPMENT BETWEEN 22Z AND 02Z IN FAR
NORTHERN KANSAS AS A SLIGHTLY STRONGER PIECE OF SHORT WAVE ENERGY
MOVES INTO THE AREA FROM CENTRAL NEBRASKA. CONVECTIVE DEVELOPMENT
DEPENDS LARGELY ON WHETHER THE MID/UPPER FORCING WILL ARRIVE BEFORE
THE CAP STRENGTHENS. AT THE CURRENT TIME...IT APPEARS THAT A FEW
STORMS WILL BE POSSIBLE THROUGH MID EVENING WITH ISOLATED STRONG
WIND GUSTS ASSOCIATED WITH ANY STRONG STORMS.
YET ANOTHER SHORT WAVE TROUGH WILL MOVE FROM THE DAKOTAS SOUTH INTO
NORTHEAST KANSAS ON FRIDAY WITH ISOLATED TO SCATTERED STORMS
EXPECTED JUST ABOUT ANY TIME DURING THE DAY. THE BEST CHANCES APPEAR
TO BE IN NORTHEAST AND EAST CENTRAL KANSAS. THIS WILL BE A
CONVECTIVE SET UP SIMILAR TO THURSDAY WITH SLIGHTLY MORE DEEP LAYER
SHEAR AND A SLIGHTLY SHALLOWER DRY ADIABATIC LAYER. COULD SEE A FEW
STRONG STORMS WITH ISOLATED HAIL OR STRONG WIND GUSTS. HIGH TEMPS
WILL BE DEPENDENT UPON DAYTIME CLOUD COVER BUT WOULD EXPECT THE
ENTIRE AREA TO HIT THE MIDDLE 90S WITH SOME HIGHER READINGS POSSIBLE
IN AREAS WITH LESS CLOUDS.
BARJENBRUCH
SATURDAY THROUGH THURSDAY...EXPECT SHOWERS AND THUNDERSTORMS TO
WIND DOWN ON FRIDAY NIGHT INTO SATURDAY MORNING...WITH THE BEST
CHANCES FOR SHOWERS ENDING GRADUALLY FROM WEST TO EAST. THE
WARMING TREND WILL CONTINUE THROUGH THE WEEKEND AND NEXT WORK WEEK
AS 500 MB PRESSURE HEIGHTS WILL RISE...INDICATING THE PRESENCE OF
THE UPPER LEVEL RIDGE. WITH SOUTHERLY FLOW AND AMPLE SUNSHINE
EXPECT HIGHS TO REACH THE UPPER 90S TO LOWER 100S BY EARLY NEXT
WEEK...WITH HOT TEMPERATURES LASTING THROUGH THE ENTIRE WEEK. WILL
MAINTAIN A DRY FORECAST FOR THE REST OF THE WEEK GIVEN LACK OF ANY
LOW LEVEL TRIGGERING MECHANISM AND UPPER LEVEL SUPPORT. LONG RANGE
MODELS HINT AT THE POSSIBILITY OF A VERY WEAK BOUNDARY MOVING INTO
NORTHEAST KANSAS BY THE WED/THU TIME PERIOD AND THIS BOUNDARY MAY
BE ABLE TO KICK OFF SOME SHOWERS...BUT GIVEN HOW WEAK THE BOUNDARY
LOOKS TO BE IT MAY STALL OUT NORTH OF THE FORECAST AREA. SHOULD
THE BOUNDARY BE ABLE TO SLIDE SOUTH OF THE KS/NE BORDER SOME
SLIGHT RELIEF FROM THE HEAT WOULD BE EXPERIENCED NORTH OF THE
BOUNDARY.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
126 AM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 122 AM EDT FRI JUL 13 2012
STEADY BUT MOSTLY LIGHT RAIN...IDEAL TO BREAK THE RECENT DROUGHT
CONTINUES WITH RADAR STILL SHOWING MORE RAIN ADVANCING THROUGH MIDDLE
TENN. UPDATED GRIDS TO REFLECT CURRENT VALUES BUT NO CHANGE NEEDED
FOR ZONES.
UPDATE ISSUED AT 1050 PM EDT THU JUL 12 2012
ISSUED AN UPDATE TO FRESHEN UP THE GRIDS. THE FORECAST IS IN GREAT
SHAPE AND A NEW ZFP WILL NOT BE NEEDED. SENT THE GRIDS TO NDFD.
UPDATE ISSUED AT 854 PM EDT THU JUL 12 2012
WITH THE BOUNDARY DOWN SOUTH SLOW TO GENERATE AND PUSH NORTH TO
PROVIDE SOME INSTABILITY...HAVE ISSUED AN UPDATE. PULLED THUNDER OUT
OF THE EARLY PART OF THE NIGHT TILL DAWN AS LIGHTNING STRIKES HAVE
BEEN NONEXISTENT. LATER TONIGHT AS THE LOW CONTINUES TO DEVELOP...THE
BOUNDARY WILL EVENTUALLY SLIDE NORTH BINGING SOME INSTABILITY INTO
THE AREA. A NEW ZFP WAS ISSUED AND THE FORECAST IS GOOD TO GO.
UPDATE ISSUED AT 557 PM EDT THU JUL 12 2012
ACROSS EASTERN KENTUCKY...A SHIELD OF SOAKING RAINFALL CONTINUES TO EDGE
NORTH INTO THE FORECAST AREA WITH AN EMBEDDED RUMBLE OF THUNDER OR TWO.
THE CONVECTION NORTH OF THE EDGE OF THE RAINFALL HAS SINCE DIED OFF
AND SO WILL EXPECT FEW INSTANCES OF THUNDER THROUGH THE OVERNIGHT
PERIOD. HAVE ADJUSTED THE TEMPERATURE TRENDS AND DEWS ACCORDING TO
THE APPROACH OF THE RAINFALL. DECIDED NOT TO ISSUE A NEW ZFP AND SENT
GRIDS TO NDFD...HOWEVER...IF STRIKES ACROSS THE AREA CONTINUE TO BE
NIL INTO THE EVENING...MAY PULL THUNDER FOR THE NIGHT WITH THE NEXT
ZFP ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 340 PM EDT THU JUL 12 2012
18Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE NORTHEAST OF THE AREA
WITH AN INVERTED TROUGH TAKING SHAPE THROUGH WESTERN TENNESSEE AND UP
INTO CENTRAL KENTUCKY. AT THE NOSE OF THIS...A LARGE PCPN SHIELD IS
STEADILY OVERTAKING MORE OF THE JKL CWA FROM SOUTHEAST TO NORTHWEST.
THE THICK CLOUDS AND EARLY PCPN REALLY KEPT TEMPERATURES FROM
CLIMBING TOO HIGH IN THE CUMBERLAND VALLEY AND AS SUCH THE STABILITY
HAS TAKEN THE FORM OF MAINLY SHOWERS THERE. FURTHER TO THE NORTH AND
WEST...THOUGH...MORE HEATING AND INSTABILITY HAS LED TO HEALTHIER
CONVECTIVE CELLS AND EVEN THE ODD THUNDERSTORM. EXPECT THAT TO BE THE
CASE THROUGH THE EVENING...THOUGH THE BULK OF THE PCPN WILL FALL AS
SHOWERS. SPECIFICALLY...TEMPERATURE READINGS AT 2 PM EDT VARIED FROM
THE LOWER 80S IN THE NORTHWEST WITH THE THINNER CLOUDS...TO LOWER 70S
IN THE FAR SOUTHEAST IN THE SHOWERS. WINDS HAVE BEEN LIGHT THROUGH
THE DAY AND GENERALLY FROM THE SOUTHEAST...WHICH HAS ALSO LIKELY
HELPED TO GENERATE LOW LEVEL DOWNSLOPING WORKING AGAINST THE PCPN
THROUGH THIS AFTERNOON. EVEN SO...WHERE THE CONVECTION HAS BEEN
STRONGER IT ALSO HAS MOVED SLOWLY AND IS LEAVING BEHIND DECENT
RAINFALL TOTALS OVER A SHORT AMOUNT OF TIME...GIVEN THE HIGH PW
ENVIRONMENT.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AND FEATURES TO AFFECT THE REGION THROUGH THE SHORT TERM. KENTUCKY
AND THE MID MISSISSIPPI VALLEY WILL BE IN BETWEEN TWO RIDGES TO THE
WEST AND EAST. THIS LOWER HEIGHT REGION IS POOLING WEAK PACKETS OF
SHORTWAVE ENERGY WHILE THE NEAREST TROUGH STAYS OFF TO THE NORTH
CLOSER TO GREAT LAKES AND NOT ABLE TO PUSH OUT THE LOST ENERGY...
THROUGH SATURDAY MORNING. THE WEAKNESS ALOFT COMBINED WITH SOME
ENERGY AND HIGH PWS OVER THE AREA WILL KEEP THE THREAT OF WIDESPREAD
AND OCCASIONALLY HEAVY RAINS IN THE FORECAST FOR THE BULK OF THE
PERIOD. WITH THE MODEL SIMILARITIES HAVE FOLLOWED A BLENDED APPROACH
FAVORING THE NAM12 FOR MESOSCALE DETAILS.
SENSIBLE WEATHER WILL FEATURE A MUCH NEEDED SOAKING RAIN EVENT
THROUGH FRIDAY AS THE UPPER LEVEL FACTORS COMBINE WITH THE HIGH PWS
AIR IN PLACE TO SUPPORT CONVECTION. SPECIFICALLY...EXPECT THE BEST
CHANCE FOR HEAVY RAINS TO OCCUR LATER TONIGHT AND INTO THE FIRST
PART OF FRIDAY PER THE EVOLUTION DEPICTED IN THE LATEST HRRR AND
NAM12. THIS WILL GIVE A FAIRLY UNIFORM PATTERN OF HIGHER RAIN
AMOUNTS...BUT THERE WILL STILL LIKELY BE CONSIDERABLE VARIABILITY
WITH LOCALIZED HIGHER AMOUNTS GIVEN THE CONVECTIVE NATURE. WILL
CONTINUE TO MENTION THE EXCESSIVE POTENTIAL IN THE HWO...BUT STILL
LEAVE IT OUT FROM THE GRIDS AND ZONES. THE PCPN WILL START TO WANE
LATER ON FRIDAY AS THE CORE OF IT SHIFTS NORTHWEST AND OUT OF THE
BULK OF THE CWA. THERE WILL STILL BE A GOOD THREAT OF SHOWERS AND
EVEN A THUNDERSTORM INTO SATURDAY MORNING BUT THE BEST RAINS WILL
HAVE MOVED ON BY THEN. THIS RAIN IS QUITE BENEFICIAL AND WILL
HOPEFULLY PUT A DECENT DENT IN OUR RAINFALL DEFICIT. AS FOR TEMPS...
KEPT THEM FAIRLY UNIFORM SPATIALLY AND ELEVATIONALLY...WITH THE
DIFFERENCES DRIVEN MORE BY THE RAIN PATTERN AND HIGH MOISTURE CONTENT
OF THE AIR RATHER THAN ANY TERRAIN DIFFERENCES.
FOLLOWED THE MET TEMPERATURES AND DEWPOINTS MOST CLOSELY FOR THE
SHORT TERM AS THEY LOOKED REASONABLE FOR THE PCPN PATTERN AND MATCHED
WELL WITH THE INHERITED GRIDS. AS FOR POPS...GENERALLY ENDED UP ON
THE HIGH SIDE OF GUIDANCE...WHICH WAS ALSO FAIRLY SIMILAR THROUGH THE
PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU JUL 12 2012
THE MODELS CONTINUE TO SHOW AN UNSETTLED PATTERN TO REMAIN ACROSS
THE OHIO AND TENNESSEE VALLEYS THROUGH THE EXTENDED AS AN UPPER
LEVEL RIDGE REMAINS NEARLY ANCHORED ACROSS BERMUDA...KEEPING A
PERSISTENT FEED OF MOISTURE ACROSS EASTERN KENTUCKY...WHILE AT THE
SAME TIME EXPOSING THE REGION TO PASSING WEAK DISTURBANCES IN THE
FLOW AROUND THE RIDGE. GIVEN THE CONTINUED LOW CONFIDENCE IN TIMING
ANYTHING THIS FAR OUT...WILL KEEP THE HIGHEST POPS CENTERED AROUND
THE DIURNALLY FAVORED PERIODS. TOWARDS THE END OF THE WORK WEEK...A
NORTHERN STREAM TROUGH WILL ATTEMPT TO BRING A COLD FRONT THROUGH
THE AREA. WILL STICK WITH A SLOWER TIMING WITH THIS FEATURE.
FOR TEMPERATURES...SLIGHTLY ABOVE NORMAL READINGS WILL REIGN...WITH
HIGHS IN THE MID TO UPPER 80S...AND LOWS AROUND 70.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 130 AM EDT FRI JUL 13 2012
WITH DEVELOPING PRECIP SHIELD MOVING NORTH AND CONTINUING TO PROVIDE
AMPLE COVERAGE OF SHOWER ACTIVITY...MVFR TO IFR CONDITIONS WILL
PERSIST ACROSS THE AREA...INCLUDING THE TAF SITES...FOR MOST OF THE
NEXT 24 HOUR TAF PERIOD. WITH SOME HEATING TOMORROW...MVFR TO IFR
WILL PERSIST...BUT AS WARMER AIR TRACKS NORTH AND DAYTIME
HEATING...ADDED VCTS TO THE TAF SITES. OTHERWISE...IFR UNTIL THIS
AFTERNOON WHEN HEATING MAY BRING CONDITIONS TO VFR EVEN WITH
OCCASIONAL TSRA UNTIL AFTER SUNSET AND THEN THE FOG...BR...RETURNS
VSBY TO MVFR.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DUSTY
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1147 PM CDT THU JUL 12 2012
.AVIATION...
VFR CONDITIONS TO PREVAIL OUTSIDE CONVECTION...WHICH SHOULD ONLY
DIP BRIEFLY TO MVFR CIGS/VSBY. CONVECTION MAY HAVE EARLIER
INITIATION AS CONVERGENT BAND OFF THE COAST BECOMES MORE ACTIVE
AND SPREADS INLAND IN THE MORNING ON OUTFLOW BOUNDARIES AND SEA
BREEZE. GUST POTENTIAL CAN BE NEAR 40 KT WITH EARLY CONVECTION BUT
SETTLE TO 25 KT IN LATE MORNING/AFTERNOON AS COVERAGE INCREASES. 24/RR
&&
.PREV DISCUSSION... /ISSUED 827 PM CDT THU JUL 12 2012/
UPDATE...
..SOUNDING DISCUSSION...
NO PROBLEMS WITH THE FLIGHT THIS EVENING. THE SOUNDING SHOWS A BIT
OF A SURFACE INVERSION IN PLACE ON THE NORTHSHORE WHICH HAS HELPED
TO QUIET THE SHOWER AND THUNDERSTORM ACTIVITY. ON THE SOUTHSHORE...
A FEW STORMS ARE CONTINUING TO FIRE IN THE METRO NEW ORLEANS AREA.
A STEADY STREAM OF MOISTURE IS WORKING INTO LOWER LEVELS FROM THE
SOUTHWEST TO THE NORTHEAST ACROSS THE AREA SO ADDITIONAL
DEVELOPMENT IS POSSIBLE AS HINTED TO BY THE HRRR MODELING. THAT
SAID...CONVECTION IS ALREADY WANING OVERALL AND THERE COULD BE
ANOTHER LULL ACROSS THE ENTIRE AREA FOR SEVERAL HOURS BEFORE
THINGS BEGIN TO DEVELOP AGAIN TOMORROW. WINDS ARE OF OUT THE
SOUTHWEST AT THE SURFACE AND INTO MID LEVELS AND ARE LIGHT AND
VARIABLE ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 69 90 71 91 / 30 60 30 60
BTR 72 91 72 91 / 30 60 30 60
ASD 72 90 72 90 / 30 50 30 50
MSY 74 90 75 90 / 30 50 30 50
GPT 73 90 73 89 / 30 50 30 50
PQL 71 92 71 90 / 30 50 30 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
422 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA. THIS WILL LIMIT HEATING AND
INSTABILITY, THUS ONLY HAVE A SCHC THUNDER LIMITED TO THE I-80
CORRIDOR WITH JUST SHOWERS ELSEWHERE.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
INCREASE POPS SOUTH OF PITTSBURGH THIS AFTERNOON AND TO ACCOUNT
FOR THE LATEST TRENDS IN TEMP.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF SOUTHERN WEST VIRGINIA. A TIGHT
500MB MOISTURE GRADIENT IS LOCATED ACROSS NORTH-CENTRAL WV AND IS
SLOWLY SLIDING NORTHWARD INTO THE AREA. 1000-850MB LAYER REMAINS
QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS MUCH OF
THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA. THIS WILL LIMIT HEATING AND
INSTABILITY, THUS ONLY HAVE A SCHC THUNDER MENTION FOR MOST OF THE
AREA AND JUST SHOWERS ACROSS THE SOUTHEASTERN RIDGES.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS COULD KEEP TEMPS DOWN SOUTH OF
PITTSBURGH. MAV GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INTO CONSIDERATION AND IS CLOSER TO THE COOLER MAV
GUIDANCE FOR AREAS SOUTH OF PITTSBURGH. HIGHS ARE FORECAST TO
RANGE FROM THE MID 70S ACROSS NORTH-CENTRAL WV TO THE MID 80S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
BLEND OF RECENT SREF MODEL OUTPUT, COUPLED WITH DETAILS FROM
RECENT NAM MODEL OUTPUT, SHOW THUNDERSTORM CHANCES ACROSS THE
UPPER OHIO VALLEY INCREASING THIS PERIOD.
THIS IS DUE TO A COUPLE FACTORS. THE FIRST FACTOR IS INCREASING
SURFACE LAYER HUMIDITY THAT WILL PROMOTE INCREASED VERTICAL
INSTABILITY. THE SECOND FACTOR IS A TREND TOWARD BETTER ORGANIZED
LIFTING MECHANISMS. AT SOME POINT THERE WILL BE INCREASED
MOISTURE CONVERGENCE ALONG THE LEADING EDGE OF THE HIGHER SURFACE
DEW POINTS, A MESOSCALE FEATURE THAT COULD BE TERMED A DEW POINT
WARM FRONT. THE SLOW EASTWARD PROGRESSION OF AN UPPER LEVEL SHORT-
WAVE TROUGH NEAR THE GREAT LAKES, CAN PROVIDE ANOTHER SOURCE OF
LIFT AND INSTABILITY WITH ITS PRECEDING DIFFLUENT FLOW AND
SLIGHTLY COLDER TEMPERATURES ALOFT.
DESPITE THE INCREASED THUNDERSTORM POTENTIAL, CONCUR WITH SPC
REGARDING RESTRICTED SEVERE POTENTIAL DUE TO LACK OF VERTICAL
WIND SHEAR. THERE CAN BE MORE OF A POTENTIAL FOR HEAVIER
THUNDERSTORM RAINS DUE TO LARGER THAN NORMAL PRECIPITABLE WATER
VALUES AND POTENTIAL FOR SLOW THUNDERSTORM MOVEMENT OR TRAINING.
SOIL CONDITIONS ARE SUCH THAT MORE THAN 2 INCHES OF RAIN WOULD BE
NEEDED IN 2 HOURS OR LESS TO CAUSE FLOODING ISSUES.
FORECASTED WARMER THAN NORMAL TEMPERATURES THIS PERIOD, BUT WITH A
SLIGHTLY SMALL DIURNAL TEMPERATURE RANGE DUE TO AN INCREASED CLOUD
COVER, MORE HUMID SURFACE LAYER, AND THUNDERSTORM POTENTIAL. THIS
IS SUPPORTED BY RECENT GFS AND NAM MOS, WHICH SHOWED MOST PERIODS
WITH TEMPERATURES 2 TO 5 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
325 AM CDT FRI JUL 13 2012
.DISCUSSION...
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT OVER
THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.AVIATION.../06Z TAF ISSUANCE/
/ISSUED 1025 PM CDT THU JUL 12 2012/
LINE OF SCT SHWRS AND TSTMS EXTENDING FROM NW MN INTO SE SODAK
CONTINUES TO MAKE PROGRESS EASTWARD AHEAD OF UPPER TROF IN THE DKTS.
WEAK VORT IN NE SODAK NEAR KHON APPEARS TO BE LENDING SOME SUPPORT
TO STORMS IN WC MN TOWARD KBKX AND KHON. MID LEVEL WARM ADVECTION
SHUD HELP TO MAINTAIN SOME OF THIS ACTIVITY AS IT PUSHES EAST. PCPN
WILL BE EAST OF AXN BY TAF ISSUE TIME...AND COVERAGE PROBBLY LOW
ENUF TO CONFINE PCPN MENTION TO A VCNTY GROUP. WEAK SURFACE TROF
WILL CONTINUE TO PROGRESS EAST INTO E MN FRI AFTN AND EXPECTED TO
GENERATE ANOTHER ROUND OF SCT SHWRS AND TSTMS.
KMSP...UPSTREAM CONVECTION MAY REACH THE MSP AREA ARND 08-09Z...BUT
EXPECT COVERAGE TO REMAIN LOW ENUF TO CONFINE PCPN MENTION TO VCSH.
WEAK SURFACE TROF NEAR THE DKTS BORDER AROUND 20-21Z AND SHUD BE
SUFFICIENT INSTABILITY FOR ANOTHER ROUND OF SHWRS AND TSTMS...BUT
EXPECT BETTER COVERAGE TO BE EAST OF MSP.
/OUTLOOK/
SATURDAY...VFR WITH SHRA ENDING IN THE MORNING. WINDS NW AT 5 TO 10KTS.
SUNDAY...VFR. WINDS SE AT 5-10 KTS.
MONDAY...VFR. WINDS S-SW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
558 AM EDT FRI JUL 13 2012
.SYNOPSIS...
MOSTLY QUIET WEATHER TODAY...WITH POSSIBLY AN ISOLATED SHOWER OR
EVEN A THUNDERSTORM LATE THIS AFTERNOON AS AN UPPER LEVEL RIDGE
HOLDS ON FOR ON MORE DAY. MOISTURE WILL BEGIN TO RETURN ON
SATURDAY WITH AN INCREASING CHANCE OF RAIN AND THUNDERSTORMS
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF THE
MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT ADV
MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON. THERE
WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS AFTERNOON AS
WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG UPPER LEVEL
RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT. ALSO, MODELS
ARE DIFFERING WITH COVERAGE AND TIMING OF ANY CONVECTION THIS
AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT KEPT THE ACTUAL POP
VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF CAPE AROUND TODAY,
WITH THE NAM COMING IN AT AROUND 1600 JOULES OVER THE SOUTHERN
TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE CAPE, BRINGING
LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS SHOWING ABOUT
600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS LOOK TO BE
SOUTH OF THE GFS CAPE FORECASTED LOCATION. WENT MORE IN LINE WITH
THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH STILL KEPT
THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME WEAK
DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA
THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY LOW,
SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. MID LEVEL MOISTURE AND A WEAK
UPPER LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS AROUND 6-7K FT
TODAY. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON ACROSS NE PA
AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED
AREAL COVERAGE. OVERNIGHT, AS THIS WAVE PASSES SKIES SHOULD
SCATTER OUT WITH THE POSSIBILITY OF MVFR VSBYS AT KELM TOWARD
DAYBREAK DUE TO BR.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY LATE MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
440 AM EDT FRI JUL 13 2012
.SYNOPSIS...
MOSTLY QUIET WEATHER TODAY...WITH POSSIBLY AN ISOLATED SHOWER OR
EVEN A THUNDERSTORM LATE THIS AFTERNOON AS AN UPPER LEVEL RIDGE
HOLDS ON FOR ON MORE DAY. MOISTURE WILL BEGIN TO RETURN ON
SATURDAY WITH AN INCREASING CHANCE OF RAIN AND THUNDERSTORMS
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF THE
MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT ADV
MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON. THERE
WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS AFTERNOON AS
WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG UPPER LEVEL
RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT. ALSO, MODELS
ARE DIFFERING WITH COVERAGE AND TIMING OF ANY CONVECTION THIS
AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT KEPT THE ACTUAL POP
VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF CAPE AROUND TODAY,
WITH THE NAM COMING IN AT AROUND 1600 JOULES OVER THE SOUTHERN
TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE CAPE, BRINGING
LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS SHOWING ABOUT
600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS LOOK TO BE
SOUTH OF THE GFS CAPE FORECASTED LOCATION. WENT MORE IN LINE WITH
THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH STILL KEPT
THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME WEAK
DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA
THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY LOW,
SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. INCREASING MID LEVEL MOISTURE AND
AND A WEAK MID LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS
AROUND 6-7K FT THROUGH THE PERIOD. FOG IS NOT EXPECTED AT KELM
THIS MORNING DUE TO MID LEVEL CLOUDS AND A LARGE TEMP/DEW POINT
SPREAD AT 05Z. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON
ACROSS NE PA AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO
VERY LIMITED AREAL COVERAGE.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY MID MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
405 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM FRIDAY...THE SFC RIDGE AXIS EXTENDING WEST AND INLAND
FROM THE WESTERN ATLANTIC HIGH AKA BERMUDA HIGH...WILL REMAIN JUST
NORTH OF THE COASTAL WATERS. THIS SFC PRESSURE PATTERN WILL YIELD A
E-SE WIND FLOW AROUND 10 KT. IN FACT BY SATURDAY MORNING...MODEL
SOUNDINGS OVER THE WATERS INDICATE A DEEP TROPICAL SE FLOW TO HAVE
EVOLVED...IE. SFC THRU 50K FT. THE SFC PG WILL REMAIN RATHER RELAXED
THRU THE PERIOD...RESULTING WITH CONTINUED 10 KT WIND SPEEDS.
SCATTERED ATLANTIC SHRA ACTIVITY WILL BE HIGHER DURING THE NOCTURNAL
PORTIONS OF THE 24 HR DAY...WANING TO JUST ISOLATED DURING THE DAY.
SIG SEAS WILL BECOME DOMINATED BY THE ESE GROUND SWELL AT 1 TO 2
FT...BUILDING TO 2 TO 3 FT...AND LIKELY HIGHER BEYOND THE NEAR TERM
PERIOD. WAVEWATCH3 ILLUSTRATES THE INITIAL SWELL INCREASE
TODAY...AND THEN FURTHER BUILDING IT TO POSSIBLY UP TO 4 FT
SATURDAY. RIP CURRENT RISK WILL BE ON THE INCREASE THIS WEEKEND.
THE IN-HOUSE WATERSPOUT RISK ASSESSMENT PLACES A MODERATE CHANCE
ACROSS THE LOCAL WATERS TODAY. WILL HIGHLIGHT ITS POSSIBILITY IN THE
COASTAL SECTION OF THE HAZARDOUS WEATHER OUTLOOK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
355 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
309 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT HAS ACTUALLY PUSHED SOUTH THROUGH
WILMINGTON...WHITEVILLE...CONWAY...MARION AND FLORENCE THIS EVENING
WHERE WEAK NORTHEAST WINDS ARE NOW BEING OBSERVED. ABOVE AND AHEAD
OF THE BOUNDARY NO INCREASE IN SOUTHEAST WINDS ARE EXPECTED SO THERE
IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT BACK TO
THE THE NORTH. THERE IS LITTLE REAL AIRMASS DIFFERENCE ON EITHER
SIDE OF THE FRONT SO IMPACTS ON SENSIBLE WEATHER (OTHER THAN WIND
DIRECTION) ARE LIKELY TO BE MINOR. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A STATIONARY FRONT ACROSS THE CAROLINAS IS OUTLINED ALONG A WEAK
PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST TO NORTHEAST WINDS.
THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE NC ACROSS SOUTHERN
DUPLIN AND SAMPSON COUNTIES TO NEAR FAYETTEVILLE...THEN
SOUTHWESTWARD THROUGH BENNETTSVILLE AND DARLINGTON TO JUST NORTH OF
COLUMBIA. THUNDERSTORMS IGNITED TODAY ALONG THIS FRONT AND ALSO
ALONG THE SEABREEZE BOUNDARY...PUSHED SLOWLY NORTHWESTWARD BY THE
0-6 KM MEAN WIND. SURFACE-BASED INSTABILITY HAS BEEN NEARLY
EXHAUSTED NOW WITH RADAR PRECIPITATION ESTIMATES SHOWING AT LEAST 80
PERCENT OF OUR FORECAST AREA RECEIVED SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
155 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT HAS ACTUALLY PUSHED SOUTH THROUGH
WILMINGTON...WHITEVILLE...CONWAY...MARION AND FLORENCE THIS EVENING
WHERE WEAK NORTHEAST WINDS ARE NOW BEING OBSERVED. ABOVE AND AHEAD
OF THE BOUNDARY NO INCREASE IN SOUTHEAST WINDS ARE EXPECTED SO THERE
IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT BACK TO
THE THE NORTH. THERE IS LITTLE REAL AIRMASS DIFFERENCE ON EITHER
SIDE OF THE FRONT SO IMPACTS ON SENSIBLE WEATHER (OTHER THAN WIND
DIRECTION) ARE LIKELY TO BE MINOR. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
A STATIONARY FRONT ACROSS THE CAROLINAS IS OUTLINED ALONG A WEAK
PRESSURE TROUGH AND BY A SHIFT FROM SOUTHEAST TO NORTHEAST WINDS.
THE FRONT RUNS APPROXIMATELY FROM JACKSONVILLE NC ACROSS SOUTHERN
DUPLIN AND SAMPSON COUNTIES TO NEAR FAYETTEVILLE...THEN
SOUTHWESTWARD THROUGH BENNETTSVILLE AND DARLINGTON TO JUST NORTH OF
COLUMBIA. THUNDERSTORMS IGNITED TODAY ALONG THIS FRONT AND ALSO
ALONG THE SEABREEZE BOUNDARY...PUSHED SLOWLY NORTHWESTWARD BY THE
0-6 KM MEAN WIND. SURFACE-BASED INSTABILITY HAS BEEN NEARLY
EXHAUSTED NOW WITH RADAR PRECIPITATION ESTIMATES SHOWING AT LEAST 80
PERCENT OF OUR FORECAST AREA RECEIVED SOME RAINFALL TODAY.
INLAND CONVECTION SHOULD COMPLETELY DISSIPATE OVER THE NEXT 2 HOURS
BUT PLENTY OF CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN THROUGH THE
NIGHT. ATTENTION THEN WILL SHIFT BACK TO THE COASTAL WATERS WHERE
THE HRRR AND EVEN THE SYNOPTIC MODELS (GFS AND NAM) SHOW A RENEWED
FOCUS FOR CONVECTION AFTER MIDNIGHT. THE STEERING FLOW WILL REMAIN
ORIENTED ONSHORE MEANING WE WILL CONTINUE TO SHOW INCREASING
PROBABILITIES FOR SHOWERS AND THUNDERSTORMS FOR THE COASTAL COUNTIES
LATE TONIGHT. LOWS TONIGHT SHOULD REACH 70-75...WARMEST AT THE
BEACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY..IT WILL TURN DECIDEDLY DRIER AS WE MOVE FROM
FRI TO SAT WITH PRECIPITABLE WATER VALUES DROPPING FROM AROUND 2
INCHES FRI TO ONE AND A QUARTER INCHES DURING SAT.
BERMUDA RIDGE WILL EXPAND FROM THE WESTERN ATLANTIC AND ACROSS THE
EASTERN CAROLINAS THIS PERIOD...WITH A DEEP EASTERLY FLOW ENVELOPING
THE AREA. FRI WILL BEGIN WITH AN INVERTED TROUGH NEAR OR AT THE
COAST AND MOVING WESTWARD. THERE IS ALSO A SUBTLE FEATURE ALOFT
BEING DEPICTED BY THE MODELS...MOVING WESTWARD DURING FRI. THIS
COUPLED WITH THE SEABREEZE SHOULD BRING ANOTHER GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO COASTAL LOCATIONS DURING THE MORNING
WITH POPS INCREASING INLAND AS THESE FEATURES MOVE INLAND DURING THE
AFTERNOON WHILE LOWERING AT THE COAST. AT THIS TIME...WILL HOLD
COVERAGE AT SCATTERED ALTHOUGH LOCALLY...COVERAGE MAY BECOME
NUMEROUS. STORM MOTIONS AROUND 5 KT AND HIGH ATMOSPHERIC WATER
CONTENT SHOULD YIELD SLOW MOVING THUNDERSTORMS WITH HEAVY DOWNPOURS.
THIS MAY RESULT IN PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. EXAMINATION OF OTHER PARAMETERS INDICATE THE RISK FOR SEVERE
WEATHER IS OTHERWISE LOW AT THIS TIME.
SAT...DRIER AIR AND DEVELOPING CAP AROUND 8-10 KFT...WILL NOT BE AN
ENVIRONMENT CONDUCIVE FOR CONVECTION...EVEN ALONG THE SEABREEZE.
WILL CONFINE POPS TO SMALL CHANCE AT THIS TIME.
IT SHOULD BE NOTED THAT WITH THE DEVELOPING AND DEEPENING EASTERLY
FLOW...NOCTURNAL SHOWERS DEVELOPING ACROSS THE CLIMATOLOGICALLY
FAVORED WATERS MAY MOVE ONSHORE OVERNIGHT/EARLY MORNING HOURS AND
THIS SEEMS MOST PLAUSIBLE LATE FRI NIGHT AND SAT MORNING.
TEMPS WILL NOT DEVIATE MUCH FROM NORMAL VALUES FOR MID JULY...WITH
HIGHS AND LOWS GENERALLY STAYING WITHIN A DEG OR TWO OF NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...RETURN FLOW WILL CONTINUE AROUND BERMUDA
HIGH THROUGH THE PERIOD. LOCAL AREA WILL REMAIN ON THE WESTERN
PERIPHERY OF THE RIDGE WITH DEEPER S-SW RETURN FLOW THROUGH THE
LOW LEVELS OF THE ATMOSPHERE. A MINOR PERTURBATION IN THE FLOW MAY
RIDE THROUGH FROM THE EAST SUN INTO MON WITH INCREASED CHC OF
PCP...BUT BASICALLY EXPECT DRIER MORE SUBSIDENT CONDITIONS THROUGH
THE MID TO UPPER LEVELS THROUGH MOST OF THE PERIOD. OVERALL EXPECT
MORE TYPICAL SUMMERTIME WEATHER WITH CU BUILDING EACH AFTERNOON
AND CONVECTION POSSIBLE MAINLY ALONG SEA BREEZE AND FURTHER INLAND
ALONG PIEDMONT TROUGH.
AS RIDGE GETS SUPPRESSED A BIT FURTHER SOUTH HEADING LATE
MON THROUGH MID WEEK...A BETTER WESTERLY COMPONENT TO THE FLOW WILL
DEVELOP THROUGH THE LOW LEVELS. THIS SHOULD HELP TO PRODUCE A SLIGHT
WARMING TREND. MAX TEMPS WILL REACH BETWEEN 90 AND 95 MOST DAYS AND
REMAIN IN THE 70S OVERNIGHT.
AT THE VERY END OF PERIOD MAY SEE NORTHERN STREAM SHORTWAVE DIG DOWN
INTO THE CAROLINAS AND PUSH A FRONT THROUGH LATE THURS INTO FRI.
THIS WOULD PRODUCE MORE WIDESPREAD CONVECTION BUT TOO FAR OUT TO
FEEL CONFIDENT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR OVERNIGHT DUE FOG/STRATUS THROUGH
THE EARLY FRIDAY MORNING HRS. MORNING MVFR CONVECTION AT THE COASTAL
TERMS...WILL EXPAND TO THE INLAND TERMS THIS AFTERNOON.
FCST GUIDANCE/LATEST KLTX88D SUGGEST ADDITIONAL SHRA/TSRA TO
DEVELOP OVER THE ADJACENT ATLANTIC WATERS EARLY THIS MORNING
...SPORADICALLY MOVING ONSHORE PRIOR TO SUNRISE. FOR NOW HAVE
INTRODUCED VCSH. GIVEN ABUNDANT RAINFALL IN SOME LOCATIONS AND LIGHT
AND VARIABLE WINDS...ANTICIPATE MVFR FOG...WITH MVFR/IFR LOW CIGS
DUE TO STRATUS EARLY THIS MORNING. EXPECT ANY LINGERING FOG TO CLEAR
OUT BY SEVERAL HRS AFTER SUNRISE. GUIDANCE DEPICTS CIGS BETWEEN
2000-3000FT AND ISOLATED/SCATTERED TSRA AT THE COAST AFTER
SUNRISE...EXPANDING INLAND BY THE EARLY AFTERNOON. SYNOPTIC NE-E
WINDS 5 KT OR LESS THIS MORNING WILL VEER TO THE SE 5 TO 10 KT...
WITH GUSTS UP TO 15 KT AT THE COASTAL TERMS...BY MIDDAY. ANTICIPATE
STORMS TO GRADUALLY TAPER OFF INTO THE LATE EVENING HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...THE FRONT INLAND HAS ACTUALLY SLID SOUTH AS
A COLD FRONT TO NEAR CAPE FEAR LATE THIS EVENING. NORTHEAST WINDS
ARE NOW BEING OBSERVED AT WRIGHTSVILLE BEACH AND AT THE WILMINGTON
AIRPORT. WITH NO INCREASE IN SOUTHEASTERLY WINDS OFFSHORE EXPECTED
THERE IS LITTLE REASON TO BELIEVE THE BOUNDARY WILL SUDDENLY SHIFT
BACK TO THE NORTH OVERNIGHT...SO WE`VE ADJUSTED OUR WIND FORECAST TO
SHOW EAST TO NORTHEAST FLOW NEAR AND NORTH OF CAPE FEAR OVERNIGHT.
FORTUNATELY NO INCREASE IN WIND SPEEDS ARE EXPECTED. ANY OTHER
CHANGES TO THE FORECAST ARE MINOR THIS EVENING. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
A WEAK FRONT STALLED ACROSS THE INLAND CAROLINAS HELPED FOCUS SHOWER
AND THUNDERSTORM ACTIVITY THERE THIS AFTERNOON. ACROSS THE COASTAL
WATERS A SOUTHEAST WIND AROUND 10 KT WILL CONTINUE THROUGH THE
NIGHT. AS IS TYPICAL IN THESE TROPICAL AIRMASSES SCATTERED SHOWERS
AND EVEN A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE COASTAL WATERS
OVERNIGHT IN THIS WARM AND HUMID REGIME. ACTIVITY SHOULD GENERALLY
DRIFT TOWARD THE NORTH-NORTHWEST AND MAY BEGIN TO REACH THE BEACHES
AFTER 3 AM ACCORDING TO THE LATEST RAPID-UPDATE HRRR COMPUTER MODEL.
ALTHOUGH SEVERE WEATHER IS NOT EXPECTED BRIEFLY HEAVY RAINFALL AND
THE POTENTIAL OF WATERSPOUTS WILL EXIST.
AREA BUOYS SHOW 2-FOOT SEAS THIS EVENING WITH ALMOST ALL OF THE WAVE
ENERGY EMBODIED IN A 9-SECOND SOUTHEAST SWELL. NO SIGNIFICANT CHANGE
IS EXPECTED OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...HIGH PRESSURE WILL DOMINATE THE MARINE
ENVIRONMENT. A WEAK INVERTED TROUGH IS EXPECTED TO DEVELOP AND
PERSIST THROUGH AT LEAST THE FIRST PART OF FRI...BUT THIS FEATURE
WILL BE LOCATED MAINLY W OF THE WATERS. SE TO ESE WINDS ON FRI WILL
BACK TO A MORE EASTERLY DIRECTION ON SAT. WIND SPEEDS ARE NOT
EXPECTED TO EXCEED 15 KT. AN ESE SWELL IS EXPECTED TO INCREASE
THROUGH THE PERIOD. THE SWELL WILL LENGTHEN FROM 7 SECONDS TO 9
SECONDS. THIS SWELL WILL ALLOW OVERALL SEAS TO BUILD FROM 2 TO 3 FT
FRI TO 3 TO 4 FT SAT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...EXPECT SOUTHERLY RETURN FLOW AROUND
BERMUDA HIGH THROUGH THE PERIOD. AS HIGH BECOMES SUPPRESSED A BIT
FURTHER SOUTH MON INTO TUES EXPECT S-SE WINDS TO VEER AROUND
BECOMING MORE S TO SW. OVERALL SPEEDS SHOULD BE AROUND 10 KTS
INCREASING SLIGHTLY AND BECOMING A BIT GUSTY EACH AFTERNOONS IN
SEA BREEZE. THIS PERSISTENT SOUTHERLY PUSH WILL KEEP SEAS AROUND 2
TO 4 FT THROUGH THE PERIOD. WNA SHOWS LONGER PERIOD 9 TO 10 SECOND
E-SE SWELL MIXING WITH LOCALLY DRIVEN WIND WAVES THROUGH THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS MIAMI FL
903 AM EDT FRI JUL 13 2012
.UPDATE...
WATER VAPOR AND VISIBLE SATELLITE FROM THIS MORNING SHOWED A WEAK
TROPICAL WAVE ACROSS THE EASTERN GULF WITH SHOWER ACTIVITY OVER
THE LOCAL GULF WATERS. ISOLATED TO SCATTERED STREAMER SHOWERS
CONTINUED TO MOVE ACROSS THE LOCAL ATLANTIC WATERS AND TOWARD THE
EAST COAST. THE 12Z SOUNDING SHOWED PWATS STILL AROUND 2.1
INCHES...WITH DEEP EASTERLY FLOW ACROSS SOUTH FLORIDA.
HOWEVER...WATER VAPOR SHOWED DRIER AIR BEGINNING TO MOVE TOWARDS
THE EAST COAST OF FLORIDA THIS MORNING...AND FORECAST SOUNDINGS
SHOW THIS DRIER AIR MOVING INTO THE REGION THROUGHOUT THE DAY.
THIS SHOULD KEEP THE HIGHEST CHANCES OF RAIN FOR THE EAST COAST
AREAS IN THE MORNING TO EARLY AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL MOVE INLAND AND DRIER AIR SHOULD LIMIT ACTIVITY TO
JUST A FEW STREAMER SHOWERS BY THE MID AFTERNOON. FOR THE WEST
COAST...THE GULF COAST SEA BREEZE IS EXPECTED TO MOVE INLAND THIS
AFTERNOON. LOW LEVEL CONVERGENCE AND SEA BREEZE INTERACTIONS WILL
LEAD TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR
AND GULF COAST. LIGHTNING PROBABILITIES ARE ALSO VERY HIGH FOR THE
GULF COAST AND THE HRRR AND LOCAL WRF SUPPORT THE IDEA OF HIGH
RAIN CHANCES FOR THE GULF COAST...ESPECIALLY AFTER 18Z. THE
CURRENT FORECAST SUPPORTS THIS THINKING AS WELL...AND THE ONLY
CHANGE WAS TO BUMP UP POPS THIS MORNING FOR THE GULF WATERS DOING
TO THE ONGOING CONVECTION.
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT FRI JUL 13 2012/
AVIATION...S FLA WILL BE ON THE EAST SIDE OF A TROPICAL WAVE THAT
HAS MOVED INTO THE EASTERN GULF OF MEX. A DEEP MOIST E TO ESE WIND
FLOW HAS DEVELOPED. SCATTERED SHRA WITH ISOLD TSRA WILL MOVE W-WNW
ACROSS THE ATLC AND ONSHORE. VCSH IN E COAST TERMINALS AND EXPECT
BRIEF MVFR CIG/VSBY AS SHRA PASS WILL AMEND AS NECESSARY ESPECIALLY
IF A TSRA NEARS ANY ONE TERMINAL. EXPECT TSRA TO DEVELOP OVER THE
MAINLAND AFT 14Z AND VCTS 14Z TO 18Z AND EXPECT ACTIVITY TO MOVE
INLAND AWAY FROM THE E COAST TERMINALS. AT KAPF...DEVELOPING TSRA
INLAND FROM TERMINAL AFTER 18Z WILL MOVE W TOWARD THE GULF AND VCTS
AFT 18Z. SURFACE WINDS E COAST CALM TO E-SE < 10 KTS BECOMING 10 TO
15 KTS AFT 14Z. AT KAPF...SURFACE WINDS E < 10 KTS BECOMING SSW-SW
AFT 17Z AS WEST COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 416 AM EDT FRI JUL 13 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS RIDGING ALOFT BUILDING
INTO SOUTH FL FROM THE NORTHEAST. A MID/UPPER LEVEL LOW SPINNING
EAST OF THE BAHAMAS WILL MOVE NORTHWEST TOWARDS THE CAROLINA COAST
BY SUNDAY...BUT WITH A TROUGH EXTENDING SW OF THIS FEATURE AND
MOVING NW ACROSS SOUTH FL SAT NIGHT-SUN. PWATS WILL SLOWLY
DECREASE FROM EAST TO WEST TODAY (BUT STILL AROUND 1.75 EAST
COAST THIS AFTERNOON) BEFORE INCREASING BACK TO AROUND 2 INCHES
ALONG THIS TROUGH AXIS SAT NIGHT-SUN. IT NEVER DOES BECOME DRY
ENOUGH TO PRECLUDE ANYTHING LESS THAN CHANCE POPS. HIGHEST
MOISTURE/CONVERGENCE THIS AFTERNOON WILL BE ALONG THE GULF
COAST...SO HAVE INCREASED POPS TO LIKELY THERE FOR THIS AFTERNOON.
THE WEATHER THROUGH THE WEEKEND WILL FEATURE BEST CHANCES FOR
SHOWERS/STORMS ALONG THE ATLANTIC COAST AT NIGHT THEN OVER THE
INTERIOR/GULF IN THE AFTERNOON. THE TROUGH SAT NIGHT-SUN COULD ACT
TO PRODUCE GOOD CONVERGENCE ALONG A PORTION OF THE ATLANTIC
COAST...SO WILL NEED TO WATCH THIS IN LATER MODEL RUNS TO SEE IF
POPS MAY NEED TO BE INCREASED.
THE WEATHER PATTERN FOR NEXT WEEK WILL FEATURE RIDGING BUILDING
INTO SOUTH FLORIDA FROM THE ATLANTIC...AND THIS RIDGE WILL BE
STRONGER THAN NORMAL WHICH WILL LEAD TO INCREASING TEMPS ALONG
WITH HUMIDITY ESPECIALLY BY THE MIDDLE TO LATER PART OF NEXT WEEK.
IMPRESSIVE 500 MB HEIGHTS ARE OVER AFRICA AND INTO THE EASTERN
ATLANTIC WITH BOTH GFS/ECMWF SHOWING 500 MB HEIGHTS OF NEAR 600
DECAMETERS EARLY NEXT WEEK. THE STRONG RIDGE WILL GRADUALLY BUILD
WESTWARD WITH TIME NEXT WEEK WITH AN INCREASINGLY HOT AIRMASS
LOCALLY. GFS/ECMWF SHOW 850 MB TEMPS UP TO 20C BY MID WEEK...SOME
+2.5C ABOVE AVG. FOLLOWED CLOSER TO THE MEX/MCX GUIDANCE BEYOND
THE SHORT TERM AS OPPOSED TO BIAS CORRECTED GUIDANCE AS THE HOTTER
GFS NUMBERS LOOK MORE APPROPRIATE...AND IT COULD END UP HOTTER.
HEAT INDICES LIKELY WILL BE IN THE 100-105 RANGE ACROSS SOUTH FL.
ALSO...A FORMIDABLE SAHARAN AIR LAYER (SAL) COULD MOVE IN SOMETIME
DURING THE MIDDLE TO LATTER PART OF NEXT WEEK. THIS WOULD BRING
HAZY SKIES TO THE AREA AND A LESSER COVERAGE OF TSTORMS, THOUGH
THEY COULD BE STRONGER GIVEN INCREASED INSTABILITY. WE HAVE DAYS
TO SEE HOW STRONG THIS RIDGE WILL BE AND IF A SAL MOVES IN...BUT
RIGHT NOW IT LOOKS AS SUCH.
MARINE...WINDS WILL REMAIN LIGHT TO MODERATE WITH SEAS OF LESS
THAN 4 FEET EXPECTED THROUGH THE PERIOD...SO NO CONCERNS.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 77 / 40 30 30 30
FORT LAUDERDALE 88 79 89 78 / 40 30 30 40
MIAMI 88 77 89 78 / 40 30 30 40
NAPLES 91 74 93 75 / 60 40 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
653 AM CDT FRI JUL 13 2012
.UPDATE...
RAP TRENDS AND THE LIFT TOOL CONTINUE TO GENERALLY SUPPORT EARLIER
THINKING. CONVECTION SHOULD CONTINUE THROUGH MID MORNING BEFORE
SLOWLY DISSIPATING EITHER LATE THIS MORNING OR BY EARLY AFTERNOON.
BASED ON RADAR TRENDS...WILL ADJUST POPS FOR THE MORNING HOURS
WITH HIGHER COVERAGE IN THE NORTHWEST/NORTH PARTS OF THE CWFA. IF
THE CURRENT RAP TRENDS ARE CORRECT DIURNAL CONVECTION SHOULD
DEVELOP BY MID AFTERNOON AS THE VORT MAX/SHORTWAVE BEHIND THE
CURRENT ONE BEGINS MOVING INTO EASTERN IOWA. WEAK WIND FLOW/SHEAR
ALOFT SHOULD RESULT IN NON-SEVERE STORMS. OVERALL COVERAGE THIS
AFTERNOON WILL AGAIN BE ISOLATED TO SCATTERED. ..08..
&&
.AVIATION...
NOCTURNAL ELEVATED CONVECTION CONTINUES TO BE HELPED BY A
DISTURBANCE ALOFT. POTENTIAL MVFR CONDITIONS WITH TSRA MAY BE SEEN
AT KCID/KDBQ/KMLI 12Z-18Z/13. DIURNAL TSRA CONVECTION IS EXPECTED
TO DVLP AFT 18Z/13 AND DISSIPATE AFTER SUNSET. OTHERWISE...VFR
CONDITIONS ARE EXPECTED OUTSIDE OF TSRA THROUGH 03Z/14. THERE IS A
POSSIBILITY OF NOCTURNAL TSRA AFT 06Z/14. ..08..
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT FRI JUL 13 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
TWO TROFS ACROSS THE PLAINS. DEW POINTS WERE IN THE 50S ACROSS THE
IMMEDIATE GREAT LAKES WITH 60S OVER MOST OF THE MIDWEST.
SHORT TERM...TODAY AND TONIGHT...
SATELLITE TRENDS THE PAST SEVERAL HOURS HAS HAD CONSIDERABLE
DEVELOPMENT OF MID LEVEL CLOUDS. RADAR IN TURN HAS ALSO DEVELOPED
ELEVATED ISOLATED TO SCATTERED CONVECTION ACROSS IOWA.
RAP TRENDS AND THE LIFT TOOL HAVE BEEN QUITE USEFUL IN DEPICTING THE
CURRENT CONVECTION. THE LIFT TOOL SHOWS WEAK THETA E GRADIENTS
WORKING IN CONCERT WITH CONVERGENCE TO PRODUCE THE CONVECTION. RAP
TRENDS PERSIST THIS ACROSS ROUGHLY THE NORTHWEST TWO THIRDS OF THE
CWFA DURING THE MORNING HOURS IN ASSOCIATION WITH THE VORT MAX
MOVING THROUGH IN THE FLOW ALOFT. INTERESTINGLY...THE VORT MAX
SUDDENLY STRENGTHENS BY LATE MORNING WHICH MAY OR MAY NOT BE A
CONVECTIVE FEEDBACK ISSUE WITH THE RAP MODEL.
THE QUESTION THEN TURNS TO WHETHER OR NOT CONVECTION WILL DEVELOP
DURING THE AFTERNOON HOURS. THE LIFT TOOL HAS NEGATIVE THETA E LAPSE
RATES ACROSS THE AREA WITH SOME WEAK CONVERGENCE ALOFT. THE MAIN
VARIABLE WILL BE HOW MUCH THE CLOUDS HOLD DOWN TEMPERATURES.
CONVECTIVE TEMPERATURES ARE ESSENTIALLY IN THE UPPER 80S TO LOWER
90S WHICH IS THE FCST MAX TEMPERATURES. THUS WILL CONTINUE WITH
ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON.
ANY DIURNAL CONVECTION THAT DEVELOPS THIS AFTERNOON WILL CONTINUE
INTO THE EARLY EVENING AND SHOULD DISSIPATE SHORTLY AFTER SUNSET.
HOWEVER...ANOTHER VORT MAX IN THE FLOW IS JUST UPSTREAM SO
CONVECTION COULD PERSIST LATER INTO THE EVENING...OR...RE-DEVELOP
AROUND MIDNIGHT AND THEN PERSIST THROUGH THE NIGHT. GIVEN THE WEAK
CHARACTERISTICS OF THE FLOW ALOFT...THE SECOND SCENARIO WOULD SEEM
MORE PLAUSIBLE. INDEED THE LIFT TOOL DOES SUGGEST ANOTHER THETA E
GRADIENT MOVING INTO THE CWFA AROUND MIDNIGHT. THUS...WILL GO WITH
THE CONCEPT OF ISOLATED TO SCATTERED NOCTURNAL CONVECTION DEVELOPING
AND THEN PERSISTING THROUGH SUNRISE. ..08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THE LATEST MODEL RUNS CONTINUE TO DROP A WEAK BOUNDARY INTO THE
REGION SATURDAY. THIS SHOULD GIVE AT LEAST THE NORTHERN HALF OF
THE AREA A REASONABLE CHANCE OF SCATTERED THUNDERSTORMS
ESPECIALLY WITH THE BOUNDARY SETTLING INTO THE NORTH DURING PRIME
HEATING. WILL GO WITH 30/40 POPS FOR THE NORTHERN HALF OF THE CWFA
AND KEEP LOW CHANCE POPS GOING IN THE FAR SOUTH WHERE THUNDERSTORM
DEVELOPMENT WILL BE DEPENDENT ON OUTFLOWS TO PROVIDE SOME FOCUS
FOR TSRA INITIATION. ANY STORMS THAT DEVELOP SATURDAY SHOULD BE
OF THE PULSE VARIETY WITH THE WEAK DEEP LAYER SHEAR IN PLACE. THE
NAM WAS SHOWING CAPES EXCEEDING 3000 J/KG DURING THE AFTERNOON. IF
THESE CAPES ARE REALIZED THEN SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING SOME STRONG WINDS GUSTS. KEPT SOME LOW POPS
GOING FOR SATURDAY NIGHT WITH THE BOUNDARY STILL IN THE AREA AND
CONTINUED SOME LOW POPS SOUTHEAST SUNDAY TO ACCOUNT FOR THE ECMWF
SOLUTION WHICH HOLDS A WEAK BOUNDARY IN OUR SOUTHEAST DURING THE
DAY.
SUNDAY NIGHT AND MONDAY WARMER AIR POURS BACK TO INTO THE REGION AS
UPPER RIDGING BUILDS EAST OUT OF THE ROCKIES. IT LOOKS LIKE
WIDESPREAD 90S WILL RETURN TO THE REGION MONDAY AND TUESDAY WITH
HEAT INDICES APPROACHING 100. WITH THE RIDGE BUILDING IN...A DRY
FORECAST IS IN ORDER MONDAY AND MONDAY NIGHT.
FOR TUESDAY THROUGH THURSDAY THE GFS/ECMWF CONTINUE TO SHOW A S/W
MOVING THROUGH THE NORTHERN TIER OF STATES AND SUPPRESSING THE
MIDWEST RIDGE. THE S/W WILL ALSO DROP ANOTHER BOUNDARY SOUTH INTO
THE REGION. WITH THE GFS/ECMWF HOLDING THE BOUNDARY JUST SOUTH OF
THE AREA INTO THURSDAY WILL KEEP SOME LOW POPS GOING TUESDAY
THROUGH THURSDAY...BUT HOLD THEM IN THE SLIGHT CHANCE/LOW CHANCE
RANGE SINCE MODELS KEEP MID LEVEL TEMPS ON THE WARM SIDE NEAR THE
BOUNDARY. IF THE GFS/ECMWF PROGS VERIFY THEN A SURFACE HIGH
SETTING UP OVER THE WESTERN GREAT LAKES SHOULD KEEP EAST/NORTHEAST
LOW LEVEL FLOW OVER THE AREA FOR MID/LATE WEEK. TEMPERATURES
TUESDAY SHOULD STILL BE IN THE 90S AS THE FRONT MOVES THROUGH THEN
INCREASING EAST OR NORTHEAST FLOW WEDNESDAY INTO THURSDAY SHOULD
TAKE THE EDGE OFF THE HEAT.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
652 AM CDT FRI JUL 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
SCATTERED THUNDERSTORMS WILL PREVAIL FOR MUCH OF THE DAY AS A
SHORT WAVE MOVES SOUTHEAST ACROSS NORTHEAST KANSAS THROUGH THE
DAY. AFTER 22Z CONVECTION SHOULD COME TO AN END AS THE FORCING
WITH THE WAVE SHIFTS TO THE EAST. MAINLY STAYED WITH VCTS...BUT
DID GO WITH A TEMPO FOR TOP BETWEEN 13Z-15Z WITH MVFR VSBYS AND
ALSO CIGS WITH HEAVIER RAIN ARE POSSIBLE. VFR EXPECTED OUTSIDE OF
THE CONVECTION.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 1030AM UPDATE...STILL TRYING TO GET A HANDLE ON JUST HOW FAR
NORTH PRECIPITATION WILL MAKE IT DURING THE DAY. SURFACE DEWPOINT
DEPRESSION AT MORGANTOWN IS 6 DEGREES...WHILE IT IS 17 DEGREES AT
PITTSBURGH. 12Z PIT SOUNDING STILL SHOWS A GOOD BIT OF DRY AIR IN
THE SURFACE-850MB LAYER...AND EXPECT THAT IT COULD BE SEVERAL
HOURS BEFORE AIR IN EASTERN OHIO...NORTHERN WV PANHANDLE...AND
SOUTHWESTERN PENNSYLVANIA MOISTENS UP ENOUGH AT LOW LEVELS FOR
PRECIPITATION TO START FALLING. HAVE ALSO LOWERED HIGH
TEMPERATURES BY A FEW DEGREES IN LOCATIONS THAT HAVE CHANCE FOR
PRECIPITATION TODAY. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
817 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES ALONG WITH INCREASING HUMIDITY
WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MINOR CHANGES WERE MADE TO TEMPERATURES AND POPS BASED ON SURFACE
OBSERVATIONS AND RECENT RADAR TREND.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A TROUGH AXIS
CENTERED ACROSS THE MISSOURI VALLEY WITH THE UPPER OHIO VALLEY IN
A SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A DEVELOPING SHORT
WAVE IS RIDING NORTHEASTWARD ALONG THE OHIO RIVER ON THE EASTERN
PERIPHERY OF THE LONG WAVE TROUGH. THIS FEATURE IS PROVIDING
FORCING FOR SHOWERS ACROSS MUCH OF WEST VIRGINIA. A TIGHT 500MB
MOISTURE GRADIENT IS LOCATED ALONG THE MASON-DIXON LINE AND IS
SLOWLY SLIDING NORTHWARD INTO SOUTHWESTERN PA. 1000-850MB LAYER
REMAINS QUITE DRY WITH 10-15 DEGREE DEW POINT DEPRESSIONS ACROSS
MUCH OF THE AREA.
THE SHORT WAVE WILL SLIDE SLOWLY NORTHEASTWARD INTO NORTH-CENTRAL
WV, EASTERN OHIO, AND SOUTHWESTERN PA TODAY. FORCING FROM THE WAVE
WILL ALLOW FOR SHOWERS TO DEVELOP AND MOVE INTO AREAS SOUTH OF THE
I-70 CORRIDOR LATE THIS MORNING INTO THE EARLY AFTERNOON. THERE
IS SOME UNCERTAINTY WITH THIS FORECAST IN REGARDS TO HOW LONG IT
WILL TAKE FOR 1000-850MB LAYER TO SATURATE. DEEPER MOISTURE SHOULD
ADVECT INTO THE AREA BY EVENING. MID-LEVEL MOISTURE WILL
CONTINUE TO FILTER ACROSS THE AREA THROUGHOUT THE DAY, KEEPING SKIES
MOSTLY CLOUDY ACROSS THE AREA.
TEMP FORECAST IS CHALLENGING TODAY AS NORTHWARD ENCROACHMENT OF
LOW-LEVEL MOISTURE AND SHOWERS WILL BE LIMITING FACTORS SOUTH OF
PITTSBURGH. MAV/ECS GUIDANCE IS IN THE MID 70S FOR AREAS SOUTH OF
PITTSBURGH AND MET GUIDANCE IS IN THE MID 80S FOR HIGHS IN THE
SAME AREAS. FORECAST TAKES COOLER POCKET OF 850MB TEMPS (AROUND
13-14C) INDICATED BY GFS/ECMWF INTO CONSIDERATION FOR AREAS SOUTH
OF PITTSBURGH. HIGHS ARE FORECAST TO RANGE FROM THE MID 70S ACROSS
NORTH-CENTRAL WV TO THE MID 80S ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE SHORT WAVE WILL SHIFT NORTHEAST
OF THE AREA OVERNIGHT. 305K ISENTROPIC ANALYSIS INDICATES THAT
UPLIFT WILL CONTINUE BEHIND THIS FEATURE IN A MOIST SOUTHWESTERLY
FLOW. THUS, CHANCE POPS CONTINUE ACROSS MOST OF THE AREA
OVERNIGHT. CLOUD COVERAGE ALONG WITH WARM TD ADVECTION WILL LIMIT
LOWS TONIGHT, RANGING FROM THE UPPER 60S ACROSS NORTH-CENTRAL WV
TO THE LOWER 60S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES.
OVER THE WEEKEND, AN UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE
ACROSS THE CAROLINAS WITH THE LONG WAVE TROUGH DE-AMPLIFYING AND
SLIDING EASTWARD ACROSS THE GREAT LAKES. WITH THE UPPER OHIO
VALLEY BETWEEN THESE TWO FEATURES, IT WILL REMAIN IN A MOIST,
SOUTHWESTERLY MID-LEVEL FLOW SATURDAY AND SUNDAY. THUS, CHANCE POPS
CONTINUE THROUGH THE WEEKEND, INCREASING TO LIKELY WITH MODERATE
INSTABILITY RETURNING THUNDERSTORMS TO THE FORECAST BY THE
AFTERNOON ON SATURDAY.
THUNDERSTORMS REMAIN IN THE FORECAST THROUGH SUNDAY AS DEW POINTS
WARM INTO THE LOWER 70S AND PWATS INCREASE TO AROUND 2 INCHES
ACROSS THE MAJORITY OF THE AREA. IT IS POSSIBLE THAT A FEW OF THE
STORMS MAYS BECOME STRONG WITH GUSTY WINDS AND HEAVY DOWNPOURS
OVER THE WEEKEND. AT THIS TIME, WIND PROFILE (0-6KM BULK SHEAR
25KTS) APPEARS TO BE MARGINALLY TOO WEAK TO MENTION A SEVERE
THREAT IN THE HWO AND THUS CONCUR WITH THE STORM PREDICTION
CENTER`S GENERAL THUNDERSTORM OUTLOOK.
HIGH TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES OVER THE
WEEKEND WITH LOWS AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAINTAINED A CHANCE OF SHOWERS AND THUNDERSTORMS THIS PERIOD WITH
CONTINUED HIGHER HUMIDITY AND WARMER THAN NORMAL TEMPERATURES.
BLEND OF RECENT NAEFS AND ECMWF MODEL OUTPUT CONTINUE TO SHOW
WEAK SOUTH TO SOUTHWESTERLY WINDS AT LOW LEVELS ACROSS THE UPPER
OHIO VALLEY.
AT UPPER LEVELS, THE INITIAL WEAK SHORT-WAVE TROUGH NEAR THE GREAT
LAKES MAY BE SHEARED AS SHORT-WAVE TROUGH MOVES TOWARD THE GREAT
LAKES FROM CENTRAL CANADA. THIS SCENARIO COULD RESULT IN A
SOUTHEASTWARD MOVING COLD FRONT THROUGH THE GREAT LAKES AND
PERHAPS UPPER OHIO VALLEY, BUT LIKELY NOT BEFORE THURSDAY.
SO EXPECT CONTINUED HUMID CONDITIONS ACROSS THE UPPER OHIO VALLEY
THIS PERIOD, WHICH WILL PROMOTE A CONTINUING CHANCE OF SHOWERS AND
THUNDERSTORMS.
FORECASTED TEMPERATURES UP TO 7 DEGREES WARMER THAN NORMAL BASED
ON HPC GUIDANCE WHICH IN GENERAL WAS A COUPLE DEGREES WARMER THAN
GFS AND ECMWF MOS BUT CLOSE TO NAEFS MEDIAN VALUES.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
EAST COAST HIGH PRESSURE WILL PROVIDE GENERAL VFR CONDITIONS FOR
TODAY INTO TONIGHT, ALTHOUGH SHOWERS AND ISOLATED THUNDERSTORMS CAN
POTENTIALLY PROVIDE BRIEF RESTRICTIONS...ESPECIALLY IN THE SOUTHERN
PORTS LATE THIS MORNING AND THIS AFTERNOON.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
CONTINUED HUMID CONDITIONS WILL PROMOTE POSSIBLE RESTRICTIONS DUE
TO PATCHY FOG AND HAZE EACH MORNING, AND SCATTERED THUNDERSTORMS
AT ANY TIME.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 PM EDT FRI JUL 13 2012
.SYNOPSIS...
ISSUED AT 337 AM EDT FRI JUL 13 2012
IT WILL REMAIN SUMMERY TODAY AND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES REACHING AROUND 90 EACH DAY. WE WILL HAVE SCATTERED
CHANCES FOR SHOWERS AND THUNDERSTORMS AS A WEAK FRONT AND UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. ALTHOUGH THE PRECIPITATION
IS EXPECTED TO REMAIN SCATTERED...THE BEST CHANCE FOR RAIN WILL COME
SATURDAY INTO EARLY SATURDAY NIGHT. WE WILL SEE LITTLE CHANGE IN
TEMPERATURES INTO NEXT WEEK...WITH ANOTHER CHANCE OF SCATTERED
STORMS TUESDAY NIGHT.
&&
.UPDATE...
ISSUED AT 1159 AM EDT FRI JUL 13 2012
HAVE UPDATED TO EXPAND A SMALL CHANCE (20 POP/ISOLATED WORDING)
ACROSS THE ENTIRE FORECAST AREA. COVERAGE IS OBVIOUSLY EXPECTED TO
BE LOW...BUT THE 4KM NSSL WRF...4KM SPC WRF AND THE LATEST HRRR
ARE ALL INDICATING ISOLATED DEVELOPMENT CWA WIDE THIS AFTERNOON.
A WEAK LAKE BREEZE MAY END UP BEING A FOCUS. IN ADDITION...WATER
VAPOR IMAGERY SEEMS TO INDICATE A WEAK SHORTWAVE MOVING THROUGH
THE CWA AT THIS TIME NOTED BY A LITTLE BETTER MOISTURE IN AN
OVERALL MINIMUM ACROSS THE SOUTHERN GREAT LAKES.
MODIFYING AREA MORNING SOUNDINGS INDICATE THAT WE SHOULD BE ABLE
TO REALIZE CAPE VALUES AROUND 1000 J/KG AND LI/S AROUND -3 TO -4C.
THESE VALUES ARE WITH TEMPS AROUND 90 AND DEW POINTS IN THE UPPER
50S. THE THINKING IS WE WILL LIKELY MIX DOWN SLIGHTLY DRIER AIR.
IF WE HANG ON TO THE LOW TO MID 60S DEW POINTS...THE INSTABILITY
WILL OBVIOUSLY BE HIGHER. NOT EXPECTING ANYTHING SEVERE AS VERY
LITTLE SHEAR EXISTS. THE NAM FOR INSTANCE HAS WINDS LESS THAN 15
KNOTS ALL THE WAY THROUGH ABOUT 18000FT. SO...PULSE STORMS ARE
EXPECTED FIRING OFF LAKE BREEZE CONVERGENCE AND OUTFLOW
BOUNDARIES. GIVEN THE WEAK SHEAR THE LIFE CYCLE OF STORMS TODAY WILL
BE FAIRLY SHORT. LOCALLY HEAVY RAIN AND LIGHTNING WOULD BE THE MAIN
THREATS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
OVERALL THINKING HAS NOT CHANGED MUCH THROUGH THE SHORT TERM...
ALTHOUGH SOME TWEAKS WERE MADE FOR SATURDAY NIGHT AND SUNDAY AS
THE TIMING OF THE UPPER WAVE HAS CHANGED SOMEWHAT.
MAIN NORTHERN STREAM SHORT WAVE WAS OVER THE DAKOTAS MOVING INTO
WESTERN MN THIS MORNING. HOWEVER TROUGHING EXTENDED AS FAR EAST AS
CHICAGO WHICH RESEMBLES A WARM FRONT ALOFT. THIS FEATURE MOVES NE
FROM CHI TOWARD CENTRAL LOWER THROUGH THE DAY. THERE WAS AN
EXPANDING AREA OF CLOUDS WITH THIS FEATURE AND ALSO A FEW SPOTTY
RADAR RETURNS. SOUNDINGS ARE QUITE DRY IN THE LOW LEVELS...SO
ANYTHING THAT TRIES TO GENERATE WILL BE HIGH BASED AND SHOULD ONLY
PRODUCE THE CHANCE OF A BRIEF SHOWER. CAN NOT RULE OUT A LIGHTNING
STRIKE TOO. SEEMS LIKE THIS WILL HEAD ACROSS THE NORTHERN CWA
WHERE 20 POPS WILL BE CARRIED TODAY.
SLIGHTLY BETTER CHANCES FOR RAIN SHOULD MOVE INTO THE AREA LATE
TONIGHT...PEAKING SATURDAY INTO SATURDAY EVENING AS THE MAIN SHORT
WAVE MAKES IT EAST INTO THE GREAT LAKES. STILL NOT OVERLY
IMPRESSED BY THE LACK OF JET DYNAMICS AND THE SYSTEM IS NOT
LOADED WITH MOISTURE EITHER. FEEL OUR 40 POPS COVER IT WELL FOR
SATURDAY. HOWEVER WILL INCREASE THE FORECAST TO 40 POPS INTO
SATURDAY EVENING AS THE SHORT WAVE SHOULD CROSS THE CWA IN THIS
TIME FRAME. SEVERE POTENTIAL LOOKS VERY LOW GIVEN THE WEAK WIND
FIELDS.
MUCH OF THE ACTION APPEARS TO BE EAST OF THE AREA INTO
SUNDAY...ALTHOUGH THE SE CWA MAY STILL SEE LINGERING
SHOWERS/STORMS. THEREFORE...REMOVED POPS OVER THE NW AND LOWERED
POPS OVER THE CENTRAL CWA AS THE UPPER SUPPORT MOVES SOUTH AND
EAST. ALSO BUMPED UP MAX TEMPS SEVERAL DEGREES WITH MORE SUNSHINE
EXPECTED.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
GIVEN THE PREVAILING AND TO SOME EXTENT EXPANDING DROUGHT OVER
SOUTHWEST LOWER MICHIGAN... THE MAIN ISSUE IS CAN WE GET A
SIGNIFICANT RAINFALL EVENT DURING THIS TIME? THE OTHER ISSUE IS THE
TEMPERATURE...JUST HOW HOT DOES IT GET THIS COMING WEEK?
THROUGH THURSDAY MORNING THE MODELS ARE LARGELY IN AGREEMENT AT THE
JET STREAM LEVEL AS TO WHAT WILL HAPPEN. A SYSTEM NOW IN THE GULF OF
ALASKA RACES ACROSS SOUTHERN CANADA AND PHASES WITH THE CLOSED UPPER
LOW CURRENTLY OVER NW CANADA BUT BY THEN EAST OF HUDSON BAY. THIS
CREATES AN UPPER LEVEL JET ASSIST FOR THE GULF OF ALASKA SYSTEM AS
IT PHASES WITH THE CLOSED UPPER LOW. THAT IN TURN HELPS PUSH THE
COLD FRONT SOUTH INTO THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IT IS AT THIS TIME WE STAND OUR BEST CHANCE OF SEEING
SHOWERS AND THUNDERSTORMS ACROSS THE CWA. BEYOND THAT SOME ISSUES
DEVELOP WITH THE NEXT PACIFIC SYSTEM LATE IN THE WEEK WHERE THE
ECMWF IS STRONGER WITH THE SYSTEM THAT COMES ON SHORE IN THE PACIFIC
NORTHWEST WHICH LEADS TO A LARGER UP-STREAM SUBTROPICAL HIGH.
AS FOR OUR CONVECTION WITH THE COLD FRONT TUESDAY NIGHT... THAT BY
ITSELF IS AN ISSUE. THE FRONT IS COMING THROUGH EARLY WEDNESDAY
MORNING. NOT THE BEST TIME FOR CONVECTION IN THE FIRST PLACE. ON THE
UP SIDE THE PRECIPITABLE WATER WILL BE OVER 2 INCHES (NEARLY DOUBLE
NORMAL). ALSO THERE IS A TAIL OF UPPER LEVEL JET CORE CROSSING
CENTRAL LOWER MICHIGAN TUESDAY NIGHT INTO WEDNESDAY MORNING THAT
PUTS SOUTHWEST MICHIGAN IN THE RIGHT ENTRANCE REGION OF THE JET CORE
(THAT WILL HELP WITH THE LIFT FOR CONVECTION). THERE IS CONVERGENCE
ON THE SURFACE FRONT... ANOTHER GOOD THING. THE MOST UNSTABLE CAP IS
BETWEEN 2000 AND 3000 J/KG EVEN AT NIGHT SO THAT IS A POSITIVE TOO.
THE DEEP LAYER SHEAR IS NEAR 30 KNOTS DUE TO JET CORE MOVING
THROUGH. SO IT WOULD SEEM WE DO HAVE A SHOT AT SOME CONVECTION WITH
THE FRONT SO I HAVE BETWEEN 30 AND 40 PCT FOR NOW AND CALLED THAT
GOOD.
THE OVER RIDING STORY FOR THIS WEEK THROUGH IS THE POLAR JET STREAM
STAYS WELL NORTH OF 55 NORTH THROUGH THIS COMING WEEK (BASED ON THE
PV15 WIND MAX). THAT MEANS WHATEVER COLD PUSH WE GET WILL BE FEEBLE
AT BEST AND SHORT LIVED. OVERALL OUR HOT WEATHER WILL LIKELY
CONTINUE THROUGH THE WEEK WITH ONLY A MINOR COOL OFF (NOT EVEN TO
NORMAL) WED/THU. GIVEN THE GFS MAX TEMP FOR THE 84 HOUR THROUGH 240
HOUR (8TH THROUGH THE 11TH) AS A MEAN AVERAGE ERROR OF OVER 8
DEGREES ON THE HIGH TEMPERATURE AND BIAS IS ABOUT THE SAME... WHILE
THE ECMWF FOR THE TIME HAS A MEAN AVERAGE ERROR OF ONLY 4 DEGREES...
I PUSHED THE HIGHS UP TO BE CLOSER TO THE ECMWF VALUES THROUGH THE
WEEK. NOTE: CURIOUSLY THE ERROR FOR THE LOW TEMPS FAVORS THE GFS SO
I DID NOT DO MUCH WITH THE LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM EDT FRI JUL 13 2012
VFR CIGS/VSBY ARE EXPECTED THROUGH SATURDAY MORNING. THERE COULD
BE A FEW THUNDERSTORMS AROUND MID AFTERNOON INTO THE EARLY EVENING
SO I CONTINUED THE VCTS IN ALL THE INLAND TAF SITES TODAY. ANY
STORM WILL BE SHORT LIVED BUT THERE COULD BE A BRIEF LOWERING OF
THE VISIBILITY IN THE HEAVER SHOWERS. CLOUD BASES SHOULD STILL BE
IN THE 6000 TO 7000 FT RANGE THIS MORNING AND MORE LIKE 8000 TO
9000 FT AGL THIS AFTERNOON (BASED ON 06Z NAM12 AND 09Z RAP SOUNDINGS).
&&
.MARINE...
ISSUED AT 337 AM EDT FRI JUL 13 2012
A LIGHT SOUTHERLY FLOW WILL CONTINUE THROUGH SATURDAY...THEN
VEER TO THE WEST LATE SATURDAY NIGHT WITH THE FRONT COMING
THROUGH. WAVE ACTION SHOULD REMAIN LOW.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT FRI JUL 13 2012
PCPN LATE TONIGHT INTO EARLY SUNDAY STILL LOOKS RATHER LIGHT...NOT
THE DROUGHT BUSTER THAT WE NEED. CAN NOT RULE OUT LOCALIZED HEAVY
RAINS...BUT MOST RIVER BASIN AVERAGES WILL BE UNDER A QUARTER
INCH...HAVING VERY LITTLE HYDRO IMPACT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
651 AM EDT FRI JUL 13 2012
.SYNOPSIS...
ISSUED AT 337 AM EDT FRI JUL 13 2012
IT WILL REMAIN SUMMERY TODAY AND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES REACHING AROUND 90 EACH DAY. WE WILL HAVE SCATTERED
CHANCES FOR SHOWERS AND THUNDERSTORMS AS A WEAK FRONT AND UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. ALTHOUGH THE PRECIPITATION
IS EXPECTED TO REMAIN SCATTERED...THE BEST CHANCE FOR RAIN WILL COME
SATURDAY INTO EARLY SATURDAY NIGHT. WE WILL SEE LITTLE CHANGE IN
TEMPERATURES INTO NEXT WEEK...WITH ANOTHER CHANCE OF SCATTERED
STORMS TUESDAY NIGHT.
&&
.UPDATE...
ISSUED AT 650 AM EDT FRI JUL 13 2012
BASED ON THE NSSL WAF (13TH 00Z) AND LOOKING AT SOUNDING FROM THE
09Z RAP AND 06Z NAM12 THE DEPTH OF THE MOISTURE IN THE SOUNDINGS
INCREASE FROM 800 TO 600 MB AT 15Z TO 75O MB TO 550 MB BY 21Z.
THIS SHOULD ALLOW SOME PARCELS TO GET A LITTLE MORE DEPTH BEFORE
THE RUN IN THE VERY DRY AIR ABOVE 550 MB. WITH THE AID UPSTREAM
SHORTWAVE SEEN NICELY ON OUR WATER VAPOR LOOPS...IN COMBINATION
WITH THE LAKE BREEZE CONVERGENCE THERE SHOULD BE ENOUGH LOCALIZED
LIFT TO ALLOW A FEW SHOWERS AND ISOLATED THUNDERSTORMS TO GET
GOING. I EXPANDED THE AREA OF POTENTIAL SHOWERS TO COVER MORE OF
THE CWA. EVEN SO THE CHANCE OF ANY ONE LOCATION GETTING THE
SHOWERS WILL BE LIMITED AT BEST.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
OVERALL THINKING HAS NOT CHANGED MUCH THROUGH THE SHORT TERM...
ALTHOUGH SOME TWEAKS WERE MADE FOR SATURDAY NIGHT AND SUNDAY AS
THE TIMING OF THE UPPER WAVE HAS CHANGED SOMEWHAT.
MAIN NORTHERN STREAM SHORT WAVE WAS OVER THE DAKOTAS MOVING INTO
WESTERN MN THIS MORNING. HOWEVER TROUGHING EXTENDED AS FAR EAST AS
CHICAGO WHICH RESEMBLES A WARM FRONT ALOFT. THIS FEATURE MOVES NE
FROM CHI TOWARD CENTRAL LOWER THROUGH THE DAY. THERE WAS AN
EXPANDING AREA OF CLOUDS WITH THIS FEATURE AND ALSO A FEW SPOTTY
RADAR RETURNS. SOUNDINGS ARE QUITE DRY IN THE LOW LEVELS...SO
ANYTHING THAT TRIES TO GENERATE WILL BE HIGH BASED AND SHOULD ONLY
PRODUCE THE CHANCE OF A BRIEF SHOWER. CAN NOT RULE OUT A LIGHTNING
STRIKE TOO. SEEMS LIKE THIS WILL HEAD ACROSS THE NORTHERN CWA
WHERE 20 POPS WILL BE CARRIED TODAY.
SLIGHTLY BETTER CHANCES FOR RAIN SHOULD MOVE INTO THE AREA LATE
TONIGHT...PEAKING SATURDAY INTO SATURDAY EVENING AS THE MAIN SHORT
WAVE MAKES IT EAST INTO THE GREAT LAKES. STILL NOT OVERLY
IMPRESSED BY THE LACK OF JET DYNAMICS AND THE SYSTEM IS NOT
LOADED WITH MOISTURE EITHER. FEEL OUR 40 POPS COVER IT WELL FOR
SATURDAY. HOWEVER WILL INCREASE THE FORECAST TO 40 POPS INTO
SATURDAY EVENING AS THE SHORT WAVE SHOULD CROSS THE CWA IN THIS
TIME FRAME. SEVERE POTENTIAL LOOKS VERY LOW GIVEN THE WEAK WIND
FIELDS.
MUCH OF THE ACTION APPEARS TO BE EAST OF THE AREA INTO
SUNDAY...ALTHOUGH THE SE CWA MAY STILL SEE LINGERING
SHOWERS/STORMS. THEREFORE...REMOVED POPS OVER THE NW AND LOWERED
POPS OVER THE CENTRAL CWA AS THE UPPER SUPPORT MOVES SOUTH AND
EAST. ALSO BUMPED UP MAX TEMPS SEVERAL DEGREES WITH MORE SUNSHINE
EXPECTED.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EDT FRI JUL 13 2012
GIVEN THE PREVAILING AND TO SOME EXTENT EXPANDING DROUGHT OVER
SOUTHWEST LOWER MICHIGAN... THE MAIN ISSUE IS CAN WE GET A
SIGNIFICANT RAINFALL EVENT DURING THIS TIME? THE OTHER ISSUE IS THE
TEMPERATURE...JUST HOW HOT DOES IT GET THIS COMING WEEK?
THROUGH THURSDAY MORNING THE MODELS ARE LARGELY IN AGREEMENT AT THE
JET STREAM LEVEL AS TO WHAT WILL HAPPEN. A SYSTEM NOW IN THE GULF OF
ALASKA RACES ACROSS SOUTHERN CANADA AND PHASES WITH THE CLOSED UPPER
LOW CURRENTLY OVER NW CANADA BUT BY THEN EAST OF HUDSON BAY. THIS
CREATES AN UPPER LEVEL JET ASSIST FOR THE GULF OF ALASKA SYSTEM AS
IT PHASES WITH THE CLOSED UPPER LOW. THAT IN TURN HELPS PUSH THE
COLD FRONT SOUTH INTO THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IT IS AT THIS TIME WE STAND OUR BEST CHANCE OF SEEING
SHOWERS AND THUNDERSTORMS ACROSS THE CWA. BEYOND THAT SOME ISSUES
DEVELOP WITH THE NEXT PACIFIC SYSTEM LATE IN THE WEEK WHERE THE
ECMWF IS STRONGER WITH THE SYSTEM THAT COMES ON SHORE IN THE PACIFIC
NORTHWEST WHICH LEADS TO A LARGER UP-STREAM SUBTROPICAL HIGH.
AS FOR OUR CONVECTION WITH THE COLD FRONT TUESDAY NIGHT... THAT BY
ITSELF IS AN ISSUE. THE FRONT IS COMING THROUGH EARLY WEDNESDAY
MORNING. NOT THE BEST TIME FOR CONVECTION IN THE FIRST PLACE. ON THE
UP SIDE THE PRECIPITABLE WATER WILL BE OVER 2 INCHES (NEARLY DOUBLE
NORMAL). ALSO THERE IS A TAIL OF UPPER LEVEL JET CORE CROSSING
CENTRAL LOWER MICHIGAN TUESDAY NIGHT INTO WEDNESDAY MORNING THAT
PUTS SOUTHWEST MICHIGAN IN THE RIGHT ENTRANCE REGION OF THE JET CORE
(THAT WILL HELP WITH THE LIFT FOR CONVECTION). THERE IS CONVERGENCE
ON THE SURFACE FRONT... ANOTHER GOOD THING. THE MOST UNSTABLE CAP IS
BETWEEN 2000 AND 3000 J/KG EVEN AT NIGHT SO THAT IS A POSITIVE TOO.
THE DEEP LAYER SHEAR IS NEAR 30 KNOTS DUE TO JET CORE MOVING
THROUGH. SO IT WOULD SEEM WE DO HAVE A SHOT AT SOME CONVECTION WITH
THE FRONT SO I HAVE BETWEEN 30 AND 40 PCT FOR NOW AND CALLED THAT
GOOD.
THE OVER RIDING STORY FOR THIS WEEK THROUGH IS THE POLAR JET STREAM
STAYS WELL NORTH OF 55 NORTH THROUGH THIS COMING WEEK (BASED ON THE
PV15 WIND MAX). THAT MEANS WHATEVER COLD PUSH WE GET WILL BE FEEBLE
AT BEST AND SHORT LIVED. OVERALL OUR HOT WEATHER WILL LIKELY
CONTINUE THROUGH THE WEEK WITH ONLY A MINOR COOL OFF (NOT EVEN TO
NORMAL) WED/THU. GIVEN THE GFS MAX TEMP FOR THE 84 HOUR THROUGH 240
HOUR (8TH THROUGH THE 11TH) AS A MEAN AVERAGE ERROR OF OVER 8
DEGREES ON THE HIGH TEMPERATURE AND BIAS IS ABOUT THE SAME... WHILE
THE ECMWF FOR THE TIME HAS A MEAN AVERAGE ERROR OF ONLY 4 DEGREES...
I PUSHED THE HIGHS UP TO BE CLOSER TO THE ECMWF VALUES THROUGH THE
WEEK. NOTE: CURIOUSLY THE ERROR FOR THE LOW TEMPS FAVORS THE GFS SO
I DID NOT DO MUCH WITH THE LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM EDT FRI JUL 13 2012
VFR CIGS/VSBY ARE EXPECTED THROUGH SATURDAY MORNING. THERE COULD
BE A FEW THUNDERSTORMS AROUND MID AFTERNOON INTO THE EARLY EVENING
SO I CONTINUED THE VCTS IN ALL THE INLAND TAF SITES TODAY. ANY
STORM WILL BE SHORT LIVED BUT THERE COULD BE A BRIEF LOWERING OF
THE VISIBILITY IN THE HEAVER SHOWERS. CLOUD BASES SHOULD STILL BE
IN THE 6000 TO 7000 FT RANGE THIS MORNING AND MORE LIKE 8000 TO
9000 FT AGL THIS AFTERNOON (BASED ON 06Z NAM12 AND 09Z RAP SOUNDINGS).
&&
.MARINE...
ISSUED AT 337 AM EDT FRI JUL 13 2012
A LIGHT SOUTHERLY FLOW WILL CONTINUE THROUGH SATURDAY...THEN
VEER TO THE WEST LATE SATURDAY NIGHT WITH THE FRONT COMING
THROUGH. WAVE ACTION SHOULD REMAIN LOW.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT FRI JUL 13 2012
PCPN LATE TONIGHT INTO EARLY SUNDAY STILL LOOKS RATHER LIGHT...NOT
THE DROUGHT BUSTER THAT WE NEED. CAN NOT RULE OUT LOCALIZED HEAVY
RAINS...BUT MOST RIVER BASIN AVERAGES WILL BE UNDER A QUARTER
INCH...HAVING VERY LITTLE HYDRO IMPACT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
704 AM CDT FRI JUL 13 2012
.UPDATED FOR 12Z AVIATION DISCUSSION...
&&
.DISCUSSION...
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT OVER
THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.AVIATION.../12Z TAF ISSUANCE/
AN UPPER LEVEL DISTURBANCE WILL SLIDE ACROSS THE REGION OVER THE
NEXT 24 HOURS AND CAUSE SOME SHOWERS AND THUNDERSTORMS TO DEVELOP.
THESE ARE ALREADY ONGOING NEAR THE MN/WI BORDER. EXPECT THESE
PULSE STORMS TO PERCOLATE THROUGHOUT THE DAY...WITH BETTER CHANCES
DURING THE LATE AFTERNOON AND EARLY EVENING AT THE EASTERN SITES.
KMSP...SHOWERS AND THUNDERSTORMS SEEM TO BE REDEVELOPING ON THE
EASTERN SIDE OF THE METRO THIS MORNING. ANTICIPATING A BREAK THIS
MORNING THROUGH THE EARLY AFTERNOON BEFORE MORE WIDESPREAD SHOWERS
DEVELOP ONCE AGAIN. THIS CONVECTION WILL BE VERY PULSE-LIKE IN
NATURE...SO CURRENTLY JUST HAVE A VC-GROUP. THIS WILL LIKELY NEED
TO BE FINE TUNED LATER TODAY...BUT DIDNT FEEL CONFIDENT WITH
SEVERAL HOURS OF THUNDER.
/OUTLOOK/
SATURDAY...VFR WITH TSRA ENDING. WINDS N AT 5 KT.
SUNDAY...VFR. WINDS W AT 10G15KT.
MONDAY...VFR. WINDS SSW AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/JRB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1107 AM EDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MOISTURE WILL LEAD TO ISOLATED TO SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM THIS AFTERNOON INTO EVENING...SOUTH OF THE
NEW YORK THRUWAY. MORE SIGNIFICANT MOISTURE WILL BEGIN TO RETURN
OVER THE WEEKEND WITH AN INCREASING CHANCE OF RAIN AND
THUNDERSTORMS...ESPECIALLY SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1045 AM UPDATE...
SOME MID TO HIGH LEVEL CLOUDS STREAMING INTO THE SOUTHERN PORTION
OF THE CWA AT THIS TIME. WATER VAPOR IMAGERY SHOWS HIGHER MOISTURE
VALUES ACROSS THE SOUTHERN AND CENTRAL CWA WITH DRY AIR HOLDING ON
ALONG AND NORTH OF THE THRUWAY. FORECAST PW AT VALUES ARE MUCH
HIGHER ACROSS NE PA AND THE SOUTHERN TIER OF NY WITH VALUES
APPROACHING 1.5 INCHES COMPARED TO AROUND .75 OF AN INCH ACROSS ONEIDA
COUNTY. ADDED CHANCE POPS FOR SHOWERS AND T`STORMS FOR THE CENTRAL
ZONES THIS AFTERNOON AND EVENING. EXPECTING AREAS ALONG AND NORTH
OF THE THRUWAY TO REMAIN DRY TODAY. WE ARE NOT EXPECTING ANY
SEVERE THUNDERSTORMS TODAY DUE TO NARROW CAPES AND VERY LITTLE
FLOW THROUGHOUT THE COLUMN...HOWEVER ANY STORMS THAT DO FORM WILL
BE SLOW MOVERS AND THEREFORE ADDED THE MENTION OF LOCALIZED HEAVY
RAINFALL IN THE HWO.
AS FOR TEMPERATURES, WE HAVE RAISED OUR EXPECTED MAXES A DEGREE OR
TWO INTO THE LOW TO MID 90S FOR LOWER ELEVATIONS OF THE NORTHERN
AND CENTRAL CWA WHERE A LITTLE BIT MORE SUN WILL FILTER THROUGH
THE HIGH CLOUDS. HIGHS SHOULD BE MAINLY IN THE MID TO UPPER 80S
ACROSS NE PA WITH MORE CLOUDS.
PREVIOUS DISCUSSION...
THE WEATHER SHOULD REMAIN QUIET FOR THE REMAINDER OF
THE MORNING. MODELS ARE INDICATING A MODERATE AREA OF 500MB VORT
ADV MOVING THROUGH NEPA AND THE SOUTHERN TIER THIS AFTERNOON.
THERE WILL BE MID AND UPPER LEVEL MOISTURE AVAILABLE THIS
AFTERNOON AS WELL. HOWEVER, THIS IS MOVING AROUND A FAIRLY STRONG
UPPER LEVEL RIDGE, WHICH SHOULD INHIBIT SOME OF THE DEVELOPMENT.
ALSO, MODELS ARE DIFFERING WITH COVERAGE AND TIMING OF ANY
CONVECTION THIS AFTERNOON. HAVE INCREASED COVERAGE OF POP, BUT
KEPT THE ACTUAL POP VALUE IN THE ISOLD RANGE. THERE IS PLENTY OF
CAPE AROUND TODAY, WITH THE NAM COMING IN AT AROUND 1600 JOULES
OVER THE SOUTHERN TIER TODAY. THE GFS IS NOT SO GENEROUS WITH THE
CAPE, BRINGING LESS THAN 100 JOULES TO THE SOUTHERN TIER, BUT IS
SHOWING ABOUT 600 JOULES IN THE SYRACUSE AREA. BUT, BEST DYNAMICS
LOOK TO BE SOUTH OF THE GFS CAPE FORECAST LOCATION. WENT MORE IN
LINE WITH THE NAM FOR ANY CONVECTIVE DEVELOPMENT TODAY, ALTHOUGH
STILL KEPT THE AREA FAIRLY BROAD. THE HRRR IS ALSO SHOWING SOME
WEAK DEVELOPMENT ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE
CWA THIS AFTERNOON. AS THE DAY PROGRESSES, MBE VALUES ARE FAIRLY
LOW, SO SHOWERS MAY NOT MOVE VERY FAST, AS WAS THE CASE YESTERDAY.
ALSO, PWATS LOOK TO RISE ABOVE AN INCH LATER TODAY, WHICH BOTH
SUPPORT THE NOTION OF POSSIBLE HEAVY RAIN THAT DOES NOT MOVE VERY
MUCH, IF ANY DO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH THE RETURN OF ABUNDANT MOISTURE THIS
WEEKEND. THIS WILL BE COMING UP FROM THE SOUTH, AROUND THE BERMUDA
HIGH. THEY ALSO INDICATE SEVERAL WEAK SHORT WAVES WILL MOVE
THROUGH THE UPPER LEVEL FLOW. THESE WILL COMBINE WITH THE MOISTURE
AND DAYTIME HEATING TO ALLOW THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS WEEKEND. CHANCES OF PRECIPITATION RISE THROUGH
THE WEEKEND.
BY SUNDAY, THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN AND A SFC
TROUGH MOVES ACROSS THE AREA. THIS WILL ALLOW SCT SHOWERS AND
STORMS THROUGHOUT THE DAY SUNDAY. CURRENTLY WENT WITH 50 POPS
ACROSS THE BOARD SUNDAY, BUT WOULD NOT BE SURPRISED IF HIGHER POPS
ARE NEEDED. THEN, AN UPPER LEVEL TROUGH FOLLOWS THE SFC TROUGH,
WHICH WILL PROLONG THE SHOWERS OVER THE CWA INTO SUNDAY NIGHT.
THERE IS SOME SMALL TIMING DIFFERENCES, BUT NOT ENOUGH TO MAKE A
SIGNIFICANT DIFFERENCE IN THE FORECAST. THERE IS THE POTENTIAL,
HOWEVER, FOR SOME HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
CURRENT QPF TOTALS ARE AROUND A HALF INCH FROM EARLY SUNDAY
MORNING THROUGH SUNDAY AFTERNOON. SOME MODELS ARE INDICATING THAT
AROUND AND INCH TO AN INCH AND A QUARTER ARE POSSIBLE THOUGH. OF
COURSE, THIS COULD VERY WELL CHANGE, EITHER MORE OR LESS RAIN,
OVER THE NEXT COUPLE OF MODELS RUNS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL REMAIN WARM AND HUMID THROUGH WEDNESDAY WITH
A SOUTHWEST FLOW ACROSS THE REGION DUE TO RETURN FLOW FROM HIGH
PRESSURE OFF THE MID ATLANTIC COAST. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE JUST ABOUT ANYTIME IN THIS TYPE OF PATTERN WITH THE MAIN
CHALLENGE BEING WHETHER ANY PERIODS OF ENHANCED ACTIVITY CAN BE
TIMED. COVERAGE OF STORMS IN THE ABSENCE OF SIGNIFICANT DYNAMICAL
FORCING WILL PROBABLY BE JUST 20 OR 30 PERCENT. LATEST GFS/ECMWF
GUIDANCE INDICATES THAT THE BEST CHANCE FOR STORMS WILL BE ON
WEDNESDAY AS A COLD FRONT DROPS THROUGH THE REGION. A COOLER/DRIER
AIR MASS WILL FOLLOW THE FRONT ON THURSDAY. TEMPERATURES WILL
CONTINUE TO AVERAGE ABOVE NORMAL...WITH HIGHS MAINLY IN THE MID
80S TO LOWER 90S AND LOWS IN THE 60S. HIGHS ON THURSDAY WILL BE
COOLER GENERALLY IN THE LOWER TO MIDDLE 80S.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD AS SFC HIGH
PRESSURE REMAINS OVER THE AREA. MID LEVEL MOISTURE AND A WEAK
UPPER LEVEL DISTURBANCE WILL MAKE FOR SCT/BKN CLOUDS AROUND 6-7K FT
TODAY. ISOLATED CONVECTION WILL OCCUR THIS AFTERNOON ACROSS NE PA
AND THE SOUTHERN TIER BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED
AREAL COVERAGE. OVERNIGHT, AS THIS WAVE PASSES SKIES SHOULD
SCATTER OUT WITH THE POSSIBILITY OF MVFR VSBYS AT KELM TOWARD
DAYBREAK DUE TO BR.
LIGHT AND VARIABLE WINDS BECOMING W/SW BY LATE MORNING AROUND 5
KNOTS THEN LIGHT AGAIN TONIGHT.
OUTLOOK...
SAT/SUN/MON...GENERALLY VFR. CHC FOR SCT MVFR IN
SHWRS/TSTMS...MAINLY IN THE AFTN/EVNG.
TUE...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI/MDP
NEAR TERM...MDP/SLI/MM
SHORT TERM...SLI
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1003 AM EDT FRI JUL 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE MID ATLANTIC STATES AND NEW
ENGLAND TODAY...THEN WILL SLIDE OFF THE EAST COAST DURING THE
UPCOMING WEEKEND. THIS FEATURE WILL CONTINUE TO CIRCULATE VERY WARM
AND INCREASINGLY MOIST AIR ACROSS THE REGION...RESULTING IN A
CONTINUATION OF ABOVE NORMAL TEMPERATURES...ALONG WITH SLOWLY
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
DEWPOINTS FROM KBUF TO KROC HAVE INCREASED 5-10F OVER THE PAST 24
HOURS WHILE DEWPOINTS WELL INLAND HAVE NOT CHANGED MUCH. THE 12Z
KBUF SOUNDING ALSO SHOWS A BIT MORE AVAILABLE LOW LEVEL MOISTURE
WITH PRECIPITABLE WATER CREEPING UP PAST THE ONE INCH MARK. WITH
MORE AVAILABLE LOW LEVEL MOISTURE...FORECAST CAPES WITH
TEMPERATURES NEAR 90 YIELD VALUES NEAR 1000J/KG. NUMEROUS RUNS OF
THE HRRR AND SOME OF THE HIGHER RES MODELS FROM SPC SHOW
CONVECTION THIS AFTERNOON ALONG LAKE BREEZES. CURRENT FORECAST
PORTRAYS THIS WELL WITH A 20-30 PERCENT CHANCE OF TSTORM
DEVELOPMENT LATER THIS AFTERNOON GENERALLY INLAND...WITH THE
HIGHEST THREAT ALONG THE LAKE ERIE BREEZE AND INTO THE HIGHER
TERRAIN IN THE SOUTHERN TIER. WILL LEAVE FORECAST ALONE ALTHOUGH
WILL ADD THE WORD INLAND TO THE WORDED ZFP. GRIDS LOOK GREAT.
AS WAS THE CASE YESTERDAY...THE VERY WEAK FLOW THROUGHOUT THE
DEPTH OF THE TROPOSPHERE WILL RESULT IN A VERY SLOW MOVEMENT TO
ANY SHOWERS AND STORMS THAT DO DEVELOP...RESULTING IN A POTENTIAL
FOR HIGHLY LOCALIZED AREAS OF HEAVY RAINFALL.
EXPECT ANY CONVECTION THAT FORMS THIS AFTERNOON TO ONCE AGAIN LINGER
INTO EARLY THIS EVENING...THEN SLOWLY DIE OUT AFTER SUNSET WITH THE
LOSS OF HEATING. THIS SHOULD RESULT IN A RETURN OF MAINLY DRY
WEATHER FOR THE SECOND HALF OF THE UPCOMING NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
CONDITIONS STILL LOOK FAVORABLE FOR SOME BADLY NEEDED RAINFALL
DURING THIS PERIOD...ESPECIALLY ON SUNDAY WHEN AN APPROACHING UPPER
LEVEL TROUGH WILL INTERACT WITH ABUNDANT LOW LEVEL MOISTURE THAT WILL
BE IN PLACE.
ON SATURDAY...THE MODELS ARE STILL SHOWING A VARIETY OF SOLUTIONS
REGARDING THE THE TIMING AND LOCATION OF A SERIES OF SHORTWAVES THAT
WILL BE MOVING NORTH FROM THE OHIO VALLEY. THEREFORE...WILL MAINTAIN
CONTINUITY AND INDICATE A GRADUAL SOUTH TO NORTH INCREASE IN CHANCE
POPS AS THE DEEP LAYERED SOUTHERLY FLOW TRANSPORTS INCREASING
MOISTURE NORTH TOWARD THE LOWER LAKES.
AS THE UPPER LEVEL TROUGH AND EMBEDDED SHORT WAVE HEAD EAST TOWARD
THE LOWER LAKES SATURDAY NIGHT AND SUNDAY...IT WILL INTERCEPT
MOISTURE THAT WILL BE STREAMING NORTH FROM THE OHIO VALLEY. WHILE
THIS PERIOD LOOKS TO BE OUR BEST CHANCE TO RECEIVE SOME MEASURABLE
PCPN...IT MUST BE EMPHASIZED THAT THE PRECIP MODE WILL BE
CONVECTIVE...MEANING SOME AREAS HAVE THE POTENTIAL TO RECEIVE A
CONSIDERABLE AMOUNT OF RAIN IN A SHORT AMOUNT OF TIME WHILE OTHER
AREAS RECEIVE NOTHING. THIS IS NOT THE KIND STEADY RAIN OVER AN
EXTENDED PERIOD OR AREA THAT WE TYPICALLY WANT TO MITIGATE DROUGHT
CONDITIONS. HOWEVER...THE LATEST CORFIDI VECTOR ANALYSIS DOES
HINT AT THE POSSIBILITY OF BACK BUILDING CELLS SATURDAY NIGHT INTO
SUNDAY MORNING AS A MODEST LOW LEVEL JET TRACKS EAST ACROSS WESTERN
AND CENTRAL NEW YORK. IF THIS COMES TO FRUITION...MORE BENEFICIAL
RAINFALL MAY BE POSSIBLE.
THERE IS HIGH CONFIDENCE THAT THIS WILL BE A RATHER WARM AND HUMID
PERIOD. WITH DEWPOINTS EXPECTED TO BE IN THE MID AND UPPER
60S...THERE WILL BE LITTLE RELIEF FROM THE UNCOMFORTABLE CONDITIONS
SATURDAY NIGHT. OVERNIGHT LOWS WILL RANGE FROM THE MID AND UPPER 60S
ACROSS THE SOUTHERN TIER TO THE LOWER 70S ALONG THE LAKE PLAINS.
HIGH TEMPERATURES ON SATURDAY AND SUNDAY WILL RANGE THROUGH THE
80S...ALTHOUGH SUNDAY WILL BE SLIGHTLY COOLER DUE TO THE ANTICIPATED
INCREASE IN CLOUD COVER AND BETTER CHANCE FOR RAIN.
AS THE UPPER LEVEL TROUGH PUSHES EAST INTO NEW ENGLAND SUNDAY
NIGHT...EXPECT ANY ONGOING CONVECTION TO TAPER OFF GRADUALLY FROM
WEST TO EAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
EXPECT WARM AND HUMID WEATHER TO CONTINUE THROUGH THE FIRST PORTION
OF NEXT WEEK AS THE AREA REMAINS ON THE NORTHERN FRINGE OF RETURN
FLOW AROUND THE BERMUDA HIGH ANCHORED OFF OF THE SOUTHEAST U.S.
COAST. WITH 850MB TEMPS HOLDING AROUND +18C...AND POSSIBLY
WARMER...EXPECT AFTERNOON HIGHS TO RUN IN THE UPPER 80S AND POSSIBLY
THE LOWER 90S. WITH PLENTY OF MOISTURE STILL IN PLACE...AFTERNOON
CONVECTION...MAINLY ALONG LAKE BREEZE BOUNDARIES...CANNOT BE RULED
OUT. GIVEN THE WARM AND MOIST BOUNDARY LAYER...WIDESPREAD CONVECTION
WILL LIKELY BE LIMITED BY WEAK MID-LEVEL LAPSE RATES. THERE IS ALSO
A POSSIBILITY THAT CONVECTION MAY BE TRIGGERED OR ENHANCED BY WEAK
SHORTWAVES MOVING THROUGH THE PROGRESSIVE FLOW ALOFT.
MODEL AGREEMENT IS CURRENTLY SURPRISINGLY GOOD IN SUGGESTING A
SIGNIFICANT CHANGE BY THE MIDDLE OF NEXT WEEK. NORTHERN STEAM
SHORTWAVE ENERGY IS CURRENTLY PROGGED TO PHASE WITH AN UPPER LOW
TRACKING ACROSS NORTHERN CANADA...SWINGING A STRONG SHORTWAVE TROUGH
ACROSS THE GREAT LAKES WEDNESDAY. AN ACCOMPANYING COLD FRONT IS
CURRENTLY PREDICTED TO SWING ACROSS THE LOWER GREAT LAKES SOMETIME
LATE WEDNESDAY...RESULTING IN SIGNIFICANTLY COOLER AND DRIER WEATHER
FOR THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
TODAY...EXPECT VFR CONDITIONS...WITH DIURNAL CU ALSO EXPECTED TO
REDEVELOP WITH DIURNAL HEATING.
WITH INCREASING DAYTIME INSTABILITY...ISOLATED TO SCATTERED
SHOWERS AND STORMS WILL ONCE AGAIN REDEVELOP ALONG FAVORED LAKE
BREEZE CONVERGENCE ZONES...TERRAIN FEATURES...AND LEFTOVER OUTFLOW
BOUNDARIES FROM CONVECTION YESTERDAY. THE BEST AREAL COVERAGE OF
THIS IS MOST LIKELY TO BE FROM THE WESTERN SOUTHERN TIER
NORTHEASTWARD ACROSS THE FINGER LAKES...WITH MORE SPARSE COVERAGE
MORE LIKELY FURTHER TO THE NORTH AND WEST FROM KBUF EASTWARD TO
KROC/KFZY. HAVE THEREFORE CONTINUED WITH A MENTION OF VCSH IN THE
KJHW TAF FOR NOW...WITH NO MENTION ELSEWHERE GIVEN THE EXPECTED
SPARSER COVERAGE.
TONIGHT...ANY CONVECTION SHOULD AGAIN TEND TO SLOWLY WIND DOWN
WITH THE LOSS OF HEATING THIS EVENING...LEAVING BEHIND VFR
CONDITIONS UNDER JUST SOME SCATTERED MID CLOUDS...ALONG WITH
SOME CIRRUS.
OUTLOOK...
SATURDAY AND SUNDAY...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
MONDAY AND TUESDAY...MAINLY VFR WITH THE CHANCE OF A SHOWER OR
THUNDERSTORM.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ACROSS THE LOWER GREAT LAKES REGION
TODAY...BEFORE DRIFTING OFF THE EAST COAST THIS WEEKEND. THIS
FEATURE WILL MAINTAIN GENERALLY LIGHT WINDS AND MINIMAL WAVES
THROUGH THE WEEKEND. FAIR WEATHER WILL ALSO GENERALLY CONTINUE
THROUGH TODAY...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THEN
INCREASING DURING THE COURSE OF THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...JJR/ZAFF
SHORT TERM...TJP
LONG TERM...TJP/WOOD
AVIATION...JJR
MARINE...JJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 AM EDT FRI JUL 13 2012
.SYNOPSIS...
A WEAK FRONT STALLED OVER THE CAROLINAS PLUS A HUMID TROPICAL
AIRMASS WILL BRING A CONTINUING RISK OF SHOWERS AND THUNDERSTORMS
THROUGH SATURDAY. A GRADUAL DRYING TREND WILL BEGIN SATURDAY AS
BERMUDA HIGH PRESSURE STRENGTHENS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 333 AM FRIDAY...MODELS INDICATE DEEPER ONSHORE TROPICAL
FLOW...E TO SE WINDS...WILL BECOME MORE DOMINATE THRU THE ATM COLUMN
DURING THIS NEAR TERM PERIOD. NAMBUFR HOURLY SOUNDINGS THRU SATURDAY
MORNING HIGHLIGHT THIS NICELY. VIA LATEST KLTX 88D...ALONG WITH THE
LATEST HRRR MODEL RUNS...THE ADJACENT ATLANTIC NOCTURNAL SHRA ENGINE
HAS RAMPED UP EARLY THIS MORNING. TRAJECTORIES MOVE THIS
ISOLATED/SCATTERED PCPN OCCASIONALLY ONSHORE THROUGH SUNRISE...WITH
MUCH OF IT DISSIPATING AS IT MOVES FURTHER INLAND. THIS ENGINE WILL
SLOWLY DWINDLE DOWN AFTER SUNRISE. PWS TO REMAIN IN THAT 2 INCH
REALM THRUOUT THE NEAR TERM AND WILL NOT TAKE TOO MUCH FORCING TO
IGNITE CONVECTION DURING THE DAY. DRIER AIR TO EVENTUALLY START
FILTERING INTO THE FA BY SATURDAY. NEVERTHELESS...THE DAYS
INSOLATION TO PROVIDE SOME DESTABILIZATION SEVERAL HRS AFTER SUNRISE
ALLOWING FOR CONVECTION TO DEVELOP MAINLY ALONG THE IMMEDIATE COAST.
THE ACTIVITY WILL EXPAND INLAND THRUOUT THE DAY. MODEL SOUNDINGS
INDICATE CONTINUED SLOW STORM MOTIONS IE. NW AT 5 MPH...AND WITH
PCPN MORE TROPICAL IN NATURE...EXPECT POSSIBLE HEAVY DOWNPOURS FROM
ANY CONVECTIVE ACTIVITY...EVEN WITHOUT THE PRESENCE OF THUNDER.
ONCE THE DAYS INSOLATION ENDS...OR THE AVAILABLE CAPE IS USED
UP...CONVECTION WILL QUICKLY DISSIPATE THIS EVENING...LEAVING
CONVECTIVE DEBRIS CLOUDS FOR THE REMAINDER OF TONIGHT. MODELS AGAIN
RAMP UP THE NOCTURNAL ATLANTIC SHRA ENGINE AFTER MIDNIGHT
TONIGHT...WITH SPORADIC ONSHORE MOVEMENT OF THE PCPN. AS FOR MAX/MIN
TEMPS...MAINLY COMPROMISED BETWEEN THE NAM AND GFS MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..UPPER RIDGE BUILDS INTO THE REGION FROM POINTS
EAST ON SATURDAY. MEANWHILE SURFACE HIGH ACROSS THE WEST ATLANTIC
REMAINS QUITE WEAK. A VERY DEEP BUT WEAK EAST TO SOUTHEASTERLY FLOW
WILL SET UP AND THE MID LEVELS WILL DRY SLIGHTLY BUT NOT SO MUCH HAD
THE HEIGHT RISES BUILT IN FROM THE WEST. SOME VERY BRIEF MORNING
TROPICAL SHOWERS APPEAR POSSIBLE ALONG THE COAST MAINLY IN THE
MORNING. AFTERNOON CONVECTION SHOULD BE ISOLATED AT BEST DUE TO THE
MID LEVEL DRYING...AND MAY STAY WEST OF THE FORECAST AREA
ALTOGETHER. AN UPPER LOW WILL BE APPROACHING IN THE EASTERLY FLOW
AND MODEL SPREAD IS CONSIDERABLE WITH NOT ONLY THE TRACK OF THIS
SYSTEM BUT ALSO WHETHER OR NOT IT HAS ANY SURFACE REFLECTION. MODELS
HAVE SLOWED WITH ITS PROGRESSION AND IT NOW LOOKS LIKE IT WILL STAY
EAST OF THE REGION DURING THE SHORT TERM...IF IT AFFECTS US AT ALL.
SUNDAY WILL THUS END UP VERY SIMILAR TO SATURDAY AS FAR AS RAIN
DISTRIBUTION AND CHANCES. GUIDANCE SHOWING SUNDAY AFTERNOON TURNING
OUT A LITTLE WARMER THAN SAT BUT NOT SO MUCH AS PREV FCST SO A SMALL
TWEAK WAS MADE THERE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BARRING ANY SIGNIFICANT WEATHER RESULTING FROM
THE UPPER LOW COMING FROM THE EAST THE LONG TERM LOOKS VERY QUIET.
AFOREMENTIONED LOW MAY RECURVE FROM THE COAST OR CONTINUE WESTWARD
OVER LAND...MODELS AREN`T TOO SURE. OTHERWISE MID LEVEL FLOW WILL BE
LIGHT AND VARIABLE AND THE WEST ATLANTIC HIGH WILL SHOW LITTLE
MOVEMENT. MOISTURE RETURN LOOKS WEAK BUT SOME ISOLATED DIURNAL
CONVECTION STILL SEEMS LIKELY EACH DAY. TEMPERATURES WILL BE RIGHT
WHERE THEY SHOULD BE FOR THE TIME OF YEAR.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...LIFR CONDITIONS INLAND SHOULD MIX OUT FAIRLY QUICKLY
WITH THE JULY SUN...13-14Z. A MVFR CUMULUS CEILING MAY FORM AROUND
14Z...WITH HIGH PWATS AND LOW LFC. ONSHORE FLOW WILL CREATE SHOWERS
A BIT EARLIER THAN USUAL ALONG THE SEA BREEZE BOUNDARY...MOVING WEST
OF THE COASTAL TERMINALS BY 18-19Z. A RUMBLE OF THUNDER IS
POSSIBLE...BUT MOST OF THE ACTIVITY WILL BE LOW TOPPED...TROPICAL IN
NATURE. TONIGHT...SOUTHEAST FLOW WILL PREVAIL THROUGH MOST OF THE
TROPOSPHERE WITH EXCELLENT VISIBILITIES EARLY. POSSIBLE MVFR FOG
TOWARD MORNING...DEPENDING ON CLOUD COVER AND RADIATIONAL COOLING
CONDITIONS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM FRIDAY...THE SFC RIDGE AXIS EXTENDING WEST AND INLAND
FROM THE WESTERN ATLANTIC HIGH AKA BERMUDA HIGH...WILL REMAIN JUST
NORTH OF THE COASTAL WATERS. THIS SFC PRESSURE PATTERN WILL YIELD A
E-SE WIND FLOW AROUND 10 KT. IN FACT BY SATURDAY MORNING...MODEL
SOUNDINGS OVER THE WATERS INDICATE A DEEP TROPICAL SE FLOW TO HAVE
EVOLVED...IE. SFC THRU 50K FT. THE SFC PG WILL REMAIN RATHER RELAXED
THRU THE PERIOD...RESULTING WITH CONTINUED 10 KT WIND SPEEDS.
SCATTERED ATLANTIC SHRA ACTIVITY WILL BE HIGHER DURING THE NOCTURNAL
PORTIONS OF THE 24 HR DAY...WANING TO JUST ISOLATED DURING THE DAY.
SIG SEAS WILL BECOME DOMINATED BY THE ESE GROUND SWELL AT 1 TO 2
FT...BUILDING TO 2 TO 3 FT...AND LIKELY HIGHER BEYOND THE NEAR TERM
PERIOD. WAVEWATCH3 ILLUSTRATES THE INITIAL SWELL INCREASE
TODAY...AND THEN FURTHER BUILDING IT TO POSSIBLY UP TO 4 FT
SATURDAY. RIP CURRENT RISK WILL BE ON THE INCREASE THIS WEEKEND.
THE IN-HOUSE WATERSPOUT RISK ASSESSMENT PLACES A MODERATE CHANCE
ACROSS THE LOCAL WATERS TODAY. WILL HIGHLIGHT ITS POSSIBILITY IN THE
COASTAL SECTION OF THE HAZARDOUS WEATHER OUTLOOK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY..WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC ON
SATURDAY WITH A SIMILARLY SUBTLE TROUGH WELL OFF THE COAST BY
SUNDAY. THE LATTER WILL TILT FLOW FROM THE SOUTHEAST TO EAST OR EVEN
NORTHEASTER WHILE SPEEDS REMAIN CAPPED AT JUST 10 KT. THE UPPER
FEATURE DEVELOPING THIS TROUGH IS RATHER STRONG BY JULY STANDARDS
AND COULD LEAD TO A SURFACE FEATURE STRONGER THAN CURRENTLY DEPICTED
IN GUIDANCE. IF THIS TURNS OUT TO BE THE CASE THEN WINDS WILL BE A
BIT HIGHER THAN FORECAST WITH A SIMILAR ADJUSTMENT MAYBE NEEDED FOR
SEAS. OTHERWISE WAVES WILL STAY AT OR BELOW 3 FT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SOUTHWEST WINDS GENERALLY IN THE 10 TO 15 KT
RANGE AND SEAS AVERAGING 2 TO 4 FT THROUGH THE PERIOD...THE MOST
COMMON SET OF CONDITIONS LOCALLY FOR THE SUMMER. HIGH PRESSURE
ACROSS THE WEST ATLANTIC WILL BE FAIRLY WEAK. SWELL ENERGY PROGGED
TO BE AROUND 10 SEC AND THE WIND CHOP 4-5 SECONDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1239 PM PDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MONSOON MOISTURE WILL BRING SCATTERED SHOWERS AND
THUNDERSTORMS TO THE MOUNTAINS AND DESERT THIS AFTERNOON AND
EVENING. THUNDERSTORMS WILL PRODUCE HEAVY RAIN...AND THERE IS THE
POTENTIAL FOR FLASH FLOODS. A WEAK SOUTH TO SOUTHWEST FLOW ALOFT
OVER THE WEEKEND WILL BRING DECREASING THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...
QUICK TEMPERATURE UPDATE FOR THIS AFTERNOON. VALUES IN THE SOUTH
END OF THE SJV ARE COMING IN WELL AHEAD OF EXPECTED VALUES AND
ACHIEVING BETTER THAN PRACTICALLY ALL DATA WOULD SUGGEST. ON THE
OTHER SIDE OF THE MOUNTAINS OUR DESERT AREAS ARE VERY SLOW TO WARM
THIS AFTERNOON GIVEN THE HIGH MOISTURE CONTENT OF THE AIR AND GOOD
CLOUD COVER. SEEING SOME BREAKS NOW BUT THINK THOSE WILL BE
FILLING BACK IN AS THE AFTERNOON PROGRESSES.
FLASH FLOOD WATCH STILL LOOKS GOOD. INCREASED HEAT IN THE VALLEY
COULD SUPPORT MORE INSTABILITY IN THE NEARBY MOUNTAINS FOR THE
REMAINDER OF THE DAYS. LATEST RUNS OF THE HRRR CONTINUE TO POINT
TO THE MOUNTAINS OF TULARE AND KERN COUNTIES AS THE FAVORED AREA
FOR DEVELOPMENT.
&&
.PREV DISCUSSION... /ISSUED 1005 AM PDT FRI JUL 13 2012/
DISCUSSION...
DEEP MOISTURE COVERS THE SE HALF OF OUR CWA ATTM. REGIONAL 13.12Z
RAOBS AND LATEST OBJECTIVE ANALYSIS DEPICT PRECIPITABLE WATER
VALUES NEAR 2.0 INCHES JUST TO THE SOUTHEAST OF OUR CWA WHICH IS
NEAR THE 99TH PERCENTILE FOR THE RAOB SITES. THE PLUME OF
ANOMALOUSLY HIGH MOISTURE /PLUS-4 ST DEVS/ WILL BE ORIENTED FROM
NORTH TO SOUTH ALONG THE COLORADO RIVER AND UP INTO NV/UT...THE
HNX FORECAST AREA WILL BE JUST ON THE WESTERN PERIPHERY OF IT.
FEATURES OF NOTE ON SATELLITE IMAGERY INCLUDE THE UPPER LEVEL
LOW/POTENTIAL VORTICITY ANOMALY NEAR SAN DIEGO AND THE LARGER
LOW MOVING INTO WASHINGTON /WITH AN ASSOCIATED TROUGH DIPPING
TOWARD THE CENTRAL CALIFORNIA COAST/. THE 13.12Z NAM APPEARS TO
HAVE INITIALIZED EXCEPTIONAL WELL THIS MORNING...WILL BE UTILIZING
IT AND HRRR RUNS THROUGH THE DAY.
LATEST OBSERVATIONAL AND MODEL DATA SUPPORT OUR AREA OF CONCERN
TODAY WILL BE EASTERN FRESNO...TULARE...AND MUCH OF KERN COUNTIES.
THIS REGION WILL BE IN THE FAVORED MOISTURE CONVERGENCE AREA OF
THE SOUTHERN CALIFORNIA LOW AND WILL ALSO GET SOME MINOR UPPER
LEVEL SUPPORT FROM THE INCOMING UPSTREAM TROUGH. INSTABILITY MAY
STRUGGLE TO DEVELOP THROUGH THE DAY DUE TO THE INCREASED MOISTURE
BUT BY THIS AFTERNOON WE SHOULD SEE MLCAPE VALUES IN THE 500-1000
J/KG RANGE OVER THE SIERRA SOUTH OF KINGS CANYON AND THE
TEHACHAPIS. STORM MOTION /CORFIDI VECTORS/ SUPPORT A SLOW
SOUTHWARD MOVEMENT OF 5-10 KTS. WITH THIS SCENARIO...THE FLASH
FLOOD WATCH CURRENTLY IN EFFECT LOOKS GOOD. EXPECT SOME
PRECIPITATION TO CONTINUE INTO THE LATE EVENING/OVERNIGHT HOURS
THOUGH THE UPPER LEVEL FORCING AND DEEPEST MOISTURE WILL BE MOVING
EAST WITH TIME.
TEMPERATURES WILL BE DIFFICULT TODAY AS WELL. MID-LEVEL CLOUDS ARE
QUICKLY ERODING WHICH...AFTER A WARM MORNING...WILL ALLOW FOR A
WARM AND MUGGY AFTERNOON TO UNFOLD. SHOULD STILL SEE A SEVERAL
DEGREE DROP FROM YESTERDAY.
&&
.AVIATION...
SCATTERED THUNDERSTORMS ARE LIKELY OVER THE MOUNTAINS AND DESERT
THROUGH 18Z SATURDAY WITH ISOLATED THUNDERSTORMS POSSIBLE ALONG
THE EAST SIDE AND SOUTH END OF THE SAN JOAQUIN VALLEY AND ADJACENT
FOOTHILLS BETWEEN 20Z TODAY AND 06Z SATURDAY. OTHERWISE...VFR
CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 13 2012... UNHEALTHY IN FRESNO COUNTY. UNHEALTHY
FOR SENSITIVE GROUPS IN KERN... KINGS... MADERA... MERCED AND
TULARE COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AND/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING CAZ095-097>099.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...BEAN
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1005 AM PDT FRI JUL 13 2012
.SYNOPSIS...
INCREASING MONSOON MOISTURE WILL BRING SCATTERED SHOWERS AND
THUNDERSTORMS TO THE MOUNTAINS AND DESERT THIS AFTERNOON AND
EVENING. THUNDERSTORMS WILL PRODUCE HEAVY RAIN...AND THERE IS THE
POTENTIAL FOR FLASH FLOODS. A WEAK SOUTH TO SOUTHWEST FLOW ALOFT
OVER THE WEEKEND WILL BRING DECREASING THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...
DEEP MOISTURE COVERS THE SE HALF OF OUR CWA ATTM. REGIONAL 13.12Z
RAOBS AND LATEST OBJECTIVE ANALYSIS DEPICT PRECIPITABLE WATER
VALUES NEAR 2.0 INCHES JUST TO THE SOUTHEAST OF OUR CWA WHICH IS
NEAR THE 99TH PERCENTILE FOR THE RAOB SITES. THE PLUME OF
ANOMALOUSLY HIGH MOISTURE /PLUS-4 ST DEVS/ WILL BE ORIENTED FROM
NORTH TO SOUTH ALONG THE COLORADO RIVER AND UP INTO NV/UT...THE
HNX FORECAST AREA WILL BE JUST ON THE WESTERN PERIPHERY OF IT.
FEATURES OF NOTE ON SATELLITE IMAGERY INCLUDE THE UPPER LEVEL
LOW/POTENTIAL VORTICITY ANOMALY NEAR SAN DIEGO AND THE LARGER
LOW MOVING INTO WASHINGTON /WITH AN ASSOCIATED TROUGH DIPPING
TOWARD THE CENTRAL CALIFORNIA COAST/. THE 13.12Z NAM APPEARS TO
HAVE INITIALIZED EXCEPTIONAL WELL THIS MORNING...WILL BE UTILIZING
IT AND HRRR RUNS THROUGH THE DAY.
LATEST OBSERVATIONAL AND MODEL DATA SUPPORT OUR AREA OF CONCERN
TODAY WILL BE EASTERN FRESNO...TULARE...AND MUCH OF KERN COUNTIES.
THIS REGION WILL BE IN THE FAVORED MOISTURE CONVERGENCE AREA OF
THE SOUTHERN CALIFORNIA LOW AND WILL ALSO GET SOME MINOR UPPER
LEVEL SUPPORT FROM THE INCOMING UPSTREAM TROUGH. INSTABILITY MAY
STRUGGLE TO DEVELOP THROUGH THE DAY DUE TO THE INCREASED MOISTURE
BUT BY THIS AFTERNOON WE SHOULD SEE MLCAPE VALUES IN THE 500-1000
J/KG RANGE OVER THE SIERRA SOUTH OF KINGS CANYON AND THE
TEHACHAPIS. STORM MOTION /CORFIDI VECTORS/ SUPPORT A SLOW
SOUTHWARD MOVEMENT OF 5-10 KTS. WITH THIS SCENARIO...THE FLASH
FLOOD WATCH CURRENTLY IN EFFECT LOOKS GOOD. EXPECT SOME
PRECIPITATION TO CONTINUE INTO THE LATE EVENING/OVERNIGHT HOURS
THOUGH THE UPPER LEVEL FORCING AND DEEPEST MOISTURE WILL BE MOVING
EAST WITH TIME.
TEMPERATURES WILL BE DIFFICULT TODAY AS WELL. MID-LEVEL CLOUDS ARE
QUICKLY ERODING WHICH...AFTER A WARM MORNING...WILL ALLOW FOR A
WARM AND MUGGY AFTERNOON TO UNFOLD. SHOULD STILL SEE A SEVERAL
DEGREE DROP FROM YESTERDAY.
&&
.PREV DISCUSSION... /ISSUED 402 AM PDT FRI JUL 13 2012/
DISCUSSION...
ANOTHER UPPER TROF WAS LOCATED OVER WESTERN WA...WITH TROF AXIS
SAGGING SOUTH ALONG THE WEST COAST. THIS TROF WILL COMPETE WITH
THE MONSOON TRAJECTORY THE NEXT 24-48 HRS...BUT EVENTUALLY WILL
WIN OUT WITH A DRYING W-SW FLOW GRADUALLY SPREADING OVER CA. THIS
WILL MEAN DECREASING TSTM ACTIVITY SAT...AND EVEN LESS SUN.
HOWEVER...NOT COMPLETELY CONVINCED ALL TSTM ACTIVITY WILL END
AFTER THIS WEEKEND.
CLOUDS AND SCT PRECIP WILL BE THE CONTROLLING FACTOR IN TEMPS THE
NEXT FEW DAYS. THE OVERALL TREND THRU SUN WILL BE A GRADUAL
DOWNTURN IN THE HOT TEMPS...BUT IF ONE DAY IS MORE/OR LESS/ CLOUDY
THAN ANOTHER...TEMPS MAY NOT REFLECT THE OVERALL TREND. NIGHTS
WILL CONT TO BE WARM WHERE CLOUDS PERSIST...BUT WILL EVENTUALLY
COOL OFF AS WEAK ONSHORE FLOW ALOFT KICKS IN...AND THE SJV COMING
UNDER INCREASING MARINE INFLUENCE.
MODELS IN THE MEDIUM RANGE NOT CONSISTENT IN HANDLING WEST COAST
TROF THRU NEXT WEEK...OR PLACEMENT OF LOWEST HEIGHTS. FOR NOW
FOLLOWED PERSISTENCE WITH TEMPS AT OR SLIGHTLY LESS THAN NORMAL
AND DRY EVERYWHERE. A VERY LOW CONFIDENCE FACTOR IN THE MEDIUM
RANGE.
&&
.AVIATION...
SCATTERED THUNDERSTORMS ARE LIKELY OVER THE MOUNTAINS AND DESERT
THROUGH 18Z SATURDAY WITH ISOLATED THUNDERSTORMS POSSIBLE ALONG
THE EAST SIDE AND SOUTH END OF THE SAN JOAQUIN VALLEY AND ADJACENT
FOOTHILLS BETWEEN 20Z TODAY AND 06Z SATURDAY. OTHERWISE...VFR
CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 13 2012... UNHEALTHY IN FRESNO COUNTY. UNHEALTHY
FOR SENSITIVE GROUPS IN KERN... KINGS... MADERA... MERCED AND
TULARE COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AND/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING CAZ095-097>099.
&&
$$
PUBLIC...INIGUEZ/BINGHAM
AVN/FW...BEAN
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 PM EDT FRI JUL 13 2012
.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT THE S FL TERMINALS
THROUGH THE PERIOD. MODERATE EAST FLOW HAS PUSHED CONVECTION
INLAND AWAY FROM THE E CST EXCEPT FOR A FEW SHRA. SCT TSRA WILL
CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND MOVE W AND COULD
AFFECT THE KAPF TERMINAL UNTIL AROUND 22Z. SPARSE COVERAGE WILL
LIMIT THE CHANCES FOR A DIRECT HIT AND HAVE CONTINUED THE VCTS FOR
NOW AND WILL AMEND IF NECESSARY.
KOB
&&
.PREV DISCUSSION... /ISSUED 903 AM EDT FRI JUL 13 2012/
UPDATE...
WATER VAPOR AND VISIBLE SATELLITE FROM THIS MORNING SHOWED A WEAK
TROPICAL WAVE ACROSS THE EASTERN GULF WITH SHOWER ACTIVITY OVER
THE LOCAL GULF WATERS. ISOLATED TO SCATTERED STREAMER SHOWERS
CONTINUED TO MOVE ACROSS THE LOCAL ATLANTIC WATERS AND TOWARD THE
EAST COAST. THE 12Z SOUNDING SHOWED PWATS STILL AROUND 2.1
INCHES...WITH DEEP EASTERLY FLOW ACROSS SOUTH FLORIDA.
HOWEVER...WATER VAPOR SHOWED DRIER AIR BEGINNING TO MOVE TOWARDS
THE EAST COAST OF FLORIDA THIS MORNING...AND FORECAST SOUNDINGS
SHOW THIS DRIER AIR MOVING INTO THE REGION THROUGHOUT THE DAY.
THIS SHOULD KEEP THE HIGHEST CHANCES OF RAIN FOR THE EAST COAST
AREAS IN THE MORNING TO EARLY AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL MOVE INLAND AND DRIER AIR SHOULD LIMIT ACTIVITY TO
JUST A FEW STREAMER SHOWERS BY THE MID AFTERNOON. FOR THE WEST
COAST...THE GULF COAST SEA BREEZE IS EXPECTED TO MOVE INLAND THIS
AFTERNOON. LOW LEVEL CONVERGENCE AND SEA BREEZE INTERACTIONS WILL
LEAD TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR
AND GULF COAST. LIGHTNING PROBABILITIES ARE ALSO VERY HIGH FOR THE
GULF COAST AND THE HRRR AND LOCAL WRF SUPPORT THE IDEA OF HIGH
RAIN CHANCES FOR THE GULF COAST...ESPECIALLY AFTER 18Z. THE
CURRENT FORECAST SUPPORTS THIS THINKING AS WELL...AND THE ONLY
CHANGE WAS TO BUMP UP POPS THIS MORNING FOR THE GULF WATERS DOING
TO THE ONGOING CONVECTION.
PREV DISCUSSION... /ISSUED 740 AM EDT FRI JUL 13 2012/
AVIATION...S FLA WILL BE ON THE EAST SIDE OF A TROPICAL WAVE THAT
HAS MOVED INTO THE EASTERN GULF OF MEX. A DEEP MOIST E TO ESE WIND
FLOW HAS DEVELOPED. SCATTERED SHRA WITH ISOLD TSRA WILL MOVE W-WNW
ACROSS THE ATLC AND ONSHORE. VCSH IN E COAST TERMINALS AND EXPECT
BRIEF MVFR CIG/VSBY AS SHRA PASS WILL AMEND AS NECESSARY ESPECIALLY
IF A TSRA NEARS ANY ONE TERMINAL. EXPECT TSRA TO DEVELOP OVER THE
MAINLAND AFT 14Z AND VCTS 14Z TO 18Z AND EXPECT ACTIVITY TO MOVE
INLAND AWAY FROM THE E COAST TERMINALS. AT KAPF...DEVELOPING TSRA
INLAND FROM TERMINAL AFTER 18Z WILL MOVE W TOWARD THE GULF AND VCTS
AFT 18Z. SURFACE WINDS E COAST CALM TO E-SE < 10 KTS BECOMING 10 TO
15 KTS AFT 14Z. AT KAPF...SURFACE WINDS E < 10 KTS BECOMING SSW-SW
AFT 17Z AS WEST COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 416 AM EDT FRI JUL 13 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS RIDGING ALOFT BUILDING
INTO SOUTH FL FROM THE NORTHEAST. A MID/UPPER LEVEL LOW SPINNING
EAST OF THE BAHAMAS WILL MOVE NORTHWEST TOWARDS THE CAROLINA COAST
BY SUNDAY...BUT WITH A TROUGH EXTENDING SW OF THIS FEATURE AND
MOVING NW ACROSS SOUTH FL SAT NIGHT-SUN. PWATS WILL SLOWLY
DECREASE FROM EAST TO WEST TODAY (BUT STILL AROUND 1.75 EAST
COAST THIS AFTERNOON) BEFORE INCREASING BACK TO AROUND 2 INCHES
ALONG THIS TROUGH AXIS SAT NIGHT-SUN. IT NEVER DOES BECOME DRY
ENOUGH TO PRECLUDE ANYTHING LESS THAN CHANCE POPS. HIGHEST
MOISTURE/CONVERGENCE THIS AFTERNOON WILL BE ALONG THE GULF
COAST...SO HAVE INCREASED POPS TO LIKELY THERE FOR THIS AFTERNOON.
THE WEATHER THROUGH THE WEEKEND WILL FEATURE BEST CHANCES FOR
SHOWERS/STORMS ALONG THE ATLANTIC COAST AT NIGHT THEN OVER THE
INTERIOR/GULF IN THE AFTERNOON. THE TROUGH SAT NIGHT-SUN COULD ACT
TO PRODUCE GOOD CONVERGENCE ALONG A PORTION OF THE ATLANTIC
COAST...SO WILL NEED TO WATCH THIS IN LATER MODEL RUNS TO SEE IF
POPS MAY NEED TO BE INCREASED.
THE WEATHER PATTERN FOR NEXT WEEK WILL FEATURE RIDGING BUILDING
INTO SOUTH FLORIDA FROM THE ATLANTIC...AND THIS RIDGE WILL BE
STRONGER THAN NORMAL WHICH WILL LEAD TO INCREASING TEMPS ALONG
WITH HUMIDITY ESPECIALLY BY THE MIDDLE TO LATER PART OF NEXT WEEK.
IMPRESSIVE 500 MB HEIGHTS ARE OVER AFRICA AND INTO THE EASTERN
ATLANTIC WITH BOTH GFS/ECMWF SHOWING 500 MB HEIGHTS OF NEAR 600
DECAMETERS EARLY NEXT WEEK. THE STRONG RIDGE WILL GRADUALLY BUILD
WESTWARD WITH TIME NEXT WEEK WITH AN INCREASINGLY HOT AIRMASS
LOCALLY. GFS/ECMWF SHOW 850 MB TEMPS UP TO 20C BY MID WEEK...SOME
+2.5C ABOVE AVG. FOLLOWED CLOSER TO THE MEX/MCX GUIDANCE BEYOND
THE SHORT TERM AS OPPOSED TO BIAS CORRECTED GUIDANCE AS THE HOTTER
GFS NUMBERS LOOK MORE APPROPRIATE...AND IT COULD END UP HOTTER.
HEAT INDICES LIKELY WILL BE IN THE 100-105 RANGE ACROSS SOUTH FL.
ALSO...A FORMIDABLE SAHARAN AIR LAYER (SAL) COULD MOVE IN SOMETIME
DURING THE MIDDLE TO LATTER PART OF NEXT WEEK. THIS WOULD BRING
HAZY SKIES TO THE AREA AND A LESSER COVERAGE OF TSTORMS, THOUGH
THEY COULD BE STRONGER GIVEN INCREASED INSTABILITY. WE HAVE DAYS
TO SEE HOW STRONG THIS RIDGE WILL BE AND IF A SAL MOVES IN...BUT
RIGHT NOW IT LOOKS AS SUCH.
MARINE...WINDS WILL REMAIN LIGHT TO MODERATE WITH SEAS OF LESS
THAN 4 FEET EXPECTED THROUGH THE PERIOD...SO NO CONCERNS.
FIRE WEATHER...NO CONCERNS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
ISSUED BY NATIONAL WEATHER SERVICE WILMINGTON NC
304 PM EDT FRI JUL 13 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXPAND ACROSS THE SOUTHEAST STATES
THROUGH THE WEEKEND. HIGH PRESSURE WILL BEGIN TO SINK SOUTHWARD
BY EARLY NEXT WEEK AS A TROUGH OF LOW PRESSURE DEVELOPS INLAND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...CONVECTION ONGOING JUST WEST OF THE SEA BREEZE
AS ANTICIPATED...WITH WEAKER SHOWERS STILL ADVECTING ONSHORE DUE TO
THE DEEP SE FLOW.
LATEST RUC FORECAST PROFILES CONTINUE TO INDICATE 1500 TO 2500 J/KG
OF SURFACE BASED CAPE WHICH IS HELPING TO FUEL THE SCATTERED TSTMS
TODAY. MOST OF THE ACTIVITY IS NOW WEST OF THE SLOWLY PENETRATING
SEA BREEZE...BUT KCLX RADAR STILL INDICATES WEAK SHOWERS ADVECTING
INLAND FROM THE OCEAN. EXPECT THIS TO PERSIST AT LEAST UNTIL
NIGHTFALL...ALTHOUGH OVERALL COVERAGE AND INTENSITY WILL DECREASE
SIGNIFICANTLY WITH LOSS OF HEATING. THE BIGGEST THREAT THROUGH THE
REST OF THE EVE WILL BE VERY HEAVY RAINFALL WITH ISOLATED/LOCALIZED
FLOODING...MOSTLY WEST OF I-95. TEMPS WILL SLOWLY COOL NEAR THE
COAST WITH THE SEA BREEZE...AND LEVEL OUT NEAR 90 WELL INLAND.
AFTER NIGHTFALL THERE IS LIKELY TO BE A BREAK IN SHRA/TSRA...BUT
RENEWED ACTIVITY WILL DEVELOP ACROSS THE WATERS WHERE COOLING AIR
TEMPS WILL HELP FORCE STEEPER LOW LEVEL LAPSE RATES AND INCREASE
INSTABILITY. SIMILAR TO LAST NIGHT...SHOWERS WILL WORK TOWARDS THE
COAST AND HAVE CONTINUED SCHC TRW- ALONG THE COAST THROUGH THE
OVERNIGHT. DO NOTE A BUILDING MID LEVEL CAP DUE TO WESTWARD
RETROGRESSION OF MID LEVEL HIGH PRESSURE ACROSS THE ATLANTIC
HOWEVER...AND THIS WILL LIMIT INTENSITY AND COVERAGE OF SHOWERS.
MINS TONIGHT WILL BE TEMPERED BY CONTINUING SE FLOW AND SOME
ENHANCED LOW LEVEL CLOUD COVER. BUFR PROFILES INDICATE THAT
1500-2000 FT STRATUS WILL CREATE A CEILING DURING THE
OVERNIGHT...BUT WITH INCREASING DRY AIR ABOVE 850MB EVIDENT...EXPECT
THIS WILL BE TRANSIENT IN NATURE...MOSTLY DURING ANY SHOWERS THAT
MAY ADVECT ONSHORE. STILL...THIS WILL BE ENOUGH TO LIMIT OVERALL
COOLING...AND EXPECT MINS AROUND 73 WELL INLAND TO NEAR 80 AT THE
COAST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DEEP ONSHORE BUT RELATIVELY LIGHT WIND FLOW
TO PREVAIL OVER THE WEEKEND...BUT BECAUSE BERMUDA HIGH PRESSURE
EXPANDS WESTWARD...DRIER MID-LEVEL SUSIDENT AIR INFILTRATES THE
COLUMN VIA EASTERLY TRAJECTORIES. DESPITE NOTEWORTHY LOW-LEVEL
MOISTURE SATURDAY AND SUNDAY...THIS SOMEWHAT PARCHED AIR ALOFT
WILL SERVE TO LIMIT CONVECTIVE COVERAGE OVER THE WEEKEND AND WE
HAVE KEPT POP VALUES IN THE ISOLATED TO LOW-END SCATTERED RANGE.
THE LOWER PWAT VALUES WILL ALSO LESSEN THE FLOODING POTENTIAL.
HAVE TAYLORED POPS TO CORRELATE WITH DIURNAL HEATING AND WE SEE
LITTLE UPPER SUPPORT.
ONE ITEM OF NOTE. APPEARS A PEICE OR PORTION OF A TROPICAL WAVE
APPROACHING FLORIDA MAY INCREASE COASTAL SHOWERS OFF GA/SC. HAVE
HELP POPS IN THE ISOLATED-SCT CATEGORY HOWEVER UNTIL WE GET SOME
ADDITIONAL RESOLUTION ON THIS APPROACHING FEATURE BY 00Z MONDAY.
THE AFTERNOON SEA BREEZE CIRCULATION WILL LIKELY GENERATE SE-ESE
15-20 MPH WINDS GUSTS NEAR SHORE AND ALONG THE COAST AFTERNOONS.
THE PATTERN SUPPORTS TEMPERATURES VERY CLOSE TO CLIMATOLOGICAL
STANDARDS UPPER 80S COAST AND LOW/MID 90S INLAND...AND MAX TEMPS
NEAR THE COAST MAY BE REALIZED IN THE EARLY TO MIDDLE AFTERNOON
DUE TO THE SEA BREEZE CIRCUALTION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THIS PERIOD TO BE DOMINATED BY DEEP-LAYER HIGH PRESSURE..THOUGH
LOW PRESSURE WILL TRY TO EXERT MORE INFLUENCE BY THE MIDDLE OF
NEXT WEEK. OVERALL NO MAJOR CHANGES TO THE PREVIOUS FORECAST WITH
MAINLY SCATTERED AFTERNOON/EVENING SHOWERS AND TSTMS. POTENTIALLY
THE GREATEST COVERAGE LATE NEXT WEEK AS AN INLAND SURFACE TROUGH
DEVELOPS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 19Z...EXPECT MOST OF THE CONVECTION THIS AFTERNOON TO BE
INLAND FROM THE TERMINALS...BUT CLOSE ENOUGH FOR THE FIRST COUPLE
OF HOURS TO WARRENT A VCSH. A RUMBLE OF THUNDER IS POSSIBLE...BUT
MOST OF THE ACTIVITY WILL BE LOW TOPPED...TROPICAL IN NATURE.
TONIGHT...SOUTHEAST FLOW WILL PREVAIL THROUGH MOST OF THE
TROPOSPHERE WITH EXCELLENT VISIBILITIES EARLY. THERE MAY BE SOME
MVFR STRATUS DEVELOPMENT OVERNIGHT IN THE MOIST ENVIRONMENT...AND
SOUNDINGS SUGGEST BKN 1500 FT CIGS AT BOTH TERMINALS. HAVE
MENTIONED TEMPO MVFR FOR POTENTIAL...MOST LIKELY IN ANY SHOWERS
THAT MAY ADVECT ONSHORE DURING THE NIGHT.
SATURDAY...CONTINUE SOUTHEAST FLOW. THE ATMOSPHERE WILL BE A BIT
DRIER THAN TODAY...NEVERTHELESS AN ISOLATED SHOWER IS POSSIBLE
TOWARD THE END OF THE FORECAST PERIOD.
EXTENDED AVIATION OUTLOOK...LOW PROBABILITIES OF SUB-VFR CONDS IN
MOSTLY AFTERNOON/EVENING SH/TSTMS THROUGH THE MIDDLE OF NEXT WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...AN ONGOING 3FT/8SEC SE SWELL WILL CONTINUE
AND BE THE DOMINANT WAVE WITHIN THE SPECTRUM TODAY. LIGHT SE
WINDS OF 10-15 KTS WILL CONTRIBUTE LITTLE...SO OVERALL WAVE
HEIGHTS WILL BE 2-4 FT...HIGHEST IN THE OUTER PORTIONS OF
AMZ374. ADDITIONALLY...WINDS WILL GUST ABOVE 15 KTS NEAR THE
COAST DURING THE SEA BREEZE THROUGH THIS EVE WHICH MAY FORCE
SLIGHTLY STEEPER WAVE FACES...BUT THE MAJORITY OF THE WATERS
WILL SEE A SWELL- DOMINATED SPECTRUM. IN THIS TROPICAL AIRMASS
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
THROUGH THE PERIOD. BRIEFLY HIGHER WINDS/WAVES WITH HEAVY RAIN
WILL OCCUR WITHIN ANY OF THESE STORMS...BUT THEY WILL BE QUITE
ISOLATED BEFORE INCREASING IN COVERAGE LATE TONIGHT.
SATURDAY THROUGH WEDNESDAY...MODERATE SE-ESE WINDS EXPECTED OVER
THE WATERS THIS WEEKEND....WITH GUSTS NEAR 20 KT POSSIBLE EACH
AFTERNOON ASSOCIATED WITH THE SEA BREEZE CIRCUALTION. SEAS 3 FT
OVER THE WEEKEND BUT A FEW 4 FOOTERS MAY PREVAIL SINCE THE SE
FLOW IS PERSISTENT AND A DECENT WAVE BUILDER. EXPECT SE WAVES
SAT/SUN 3-4 FEET IN 6-8 SECOND INTERVALS. ISOLATED TSTMS ON THE
WATERS WLL BE FAVORED OVERNIGHT AND EARLY MORNING WHEN BUOYANCY
OVER THE OCEAN IS MAXIMIZED. MARINERS ARE ENCOURGAED TO CONSULT
RADAR TRENDS BEFORE HEADING OUT.
FOR MONDAY THROUGH WEDNESDAY...NEAR TYPICAL BERMUDA HIGH PRESSURE
IN PLACE AND MODERATE S-SW WINDS ARE EXPCETED. WE COULD SEE AN
INCREASE IN SW WINDS LATE TUE AS A SURFACE TROUGH AMPLIFIES OVER
THE CAROLINA INTERIOR...AGAINST BERMUDA HIGH PRESSURE OFFSHORE.
THIS COULD BRING SUSTAINED WINDS NEAR 20 KNOTS TUE AFTERNOON INTO
WEDNESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...HDL/JDW
AREA FORECAST DISCUSSION
NWS POCATELLO ID
101 PM MDT FRI JUL 13 2012
.SHORT TERM...UPPER FLOW FROM THE SOUTH TODAY IS BRINGING A LARGE
PLUME OF MONSOON MOISTURE THRU THE GREAT BASIN INTO ID. WIDESPREAD
SHOWERS AND A FEW TSTMS ARE MOVING THRU THE MAGIC VALLEY INTO THE
CENTRAL MTNS...WITH ISOLD SHOWERS ELSEWHERE. MODELS HAVING SOME
DIFFICULTY AGREEING ON A SOLUTION TONIGHT AND SATURDAY. BOTH THE
GFS AND NAM HAVE BEEN UP AND DOWN ON PRECIP CHANCES. THE NAM IS
NOT INITIALIZING AT ALL WELL WITH THE LOCATION PRECIP SO FAR...
AND THE GFS IS NOT MUCH BETTER. THE HRRR IS DOING QUITE WELL SO
FAR...BUT ONLY GOES OUT TO EARLY THIS EVENING. IT DOES SHOW A
RATHER LARGE AREA OF PRECIP MOVING NORTH FROM UT BY EARLY EVE.
THIS IS CONSISTENT WITH THE CURRENT FCST THINKING...SO WILL STAY
THE COURSE AND GO WITH INCREASING CHANCES FOR PRECIP TONIGHT AND
STAYING ON THE HIGH SIDE FOR SATURDAY. A LOOK AT MODEL SOUNDINGS
SHOW THE AIRMASS MOISTENING UP AT ALL LEVELS...SO MEASURABLE
RAINFALL AMOUNTS APPEAR LIKELY. THE PRECIP AND CLOUD COVER WILL
KEEP TEMPS ON THE COOL SIDE...SO ONLY EXPECTING ISOLD TO WIDELY
SCATTERED TSTMS EMBEDDED WITH THE SHOWERS THRU SATURDAY. BY SUNDAY
...A SMALL UPPER LOW DROPS INTO NW WA. A SMALL NORTHERN STREAM
TROF ROTATES THRU FOR MORE SHOWERS AND TSTMS ON SUNDAY.
.LONG TERM...THE UPPER LOW MIGRATES FROM NW WA TO SW OR BY MON
NIGHT... AND STAYS PUT THRU WED. THIS WILL PUSH DRIER AIR INTO THE
REGION AND RESULT IN ISOLD TO WIDELY SCATTERED TSTMS MAINLY IN THE
MTNS THRU THE END OF THE WEEK. TEMPS WILL CLIMB BACK TO NORMAL
READINGS NEXT WEEK. HEDGES
&&
.AVIATION...A STEADY STREAM OF MOISTURE WILL CONTINUE TO FLOW INTO
THE AREA THROUGH THE NEXT 24 TO 36 HOURS. SHOWERS...AND PERHAPS AN
ISOLATED THUNDERSTORM...ARE EXPECTED AT THE TERMINALS STARTING THIS
EVENING. MOS GUIDANCE MAY BE OVERDONE ON THE TS PROBABILITIES AS
MORE CLOUD COVER SHOULD CURTAIL MUCH OF THE CONVECTIVE ACTIVITY.
HINSBERGER
&&
.FIRE WEATHER...MONSOONAL MOISTURE WILL CONTINUE STREAMING INTO
IDAHO THROUGH THE WEEKEND LEADING TO INCREASED CHANCES OF A WETTING
RAINFALL. THUNDERSTORM POTENTIAL IS THE GREATEST AT THE LEADING EDGE
OF THE TROPICAL MOISTURE AND WILL THUS KEEP RED FLAG WARNING FOR THE
CENTRAL MOUNTAINS AND EASTERN HIGHLANDS BELOW 6500 FT. NO RED FLAG
HEADLINES ARE BEING CONSIDERED AT THE MOMENT FOR THE WEEKEND AS
LIGHTNING ACTIVITY SHOULD WANE DUE TO THE LACK OF SURFACE
HEATING...BUT SOME ISOLATED THUNDERSTORMS MAY OCCUR IF LIFT FROM THE
UPPER TROUGH IN OR/WA IS STRONG ENOUGH. HUMIDITY BEGINS TO DECREASE
GRADUALLY STARTING EARLY NEXT WEEK AND TEMPERATURES SHOULD ALSO
GRADUALLY RISE. HINSBERGER
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 11 PM MDT THIS EVENING BELOW 6500 FEET
FOR THE IDZ411-476-477.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
102 PM CDT FRI JUL 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
0Z UPPER AIR DATA HAD A FEW WESTERLY 60-65KT REPORTS AT 250MB IN
IDAHO AND WYOMING ROUNDING THE TOP OF THE WESTERN CONUS UPPER
RIDGE. NEARBY MID LEVELS REMAIN ON THE COOL AND DAMP SIDE
CONSIDERING LOWER LEVEL CONDITIONS OF HIGHS REACHING THE MIDDLE AND
UPPER 90S AND DEWPOINTS PRIMARILY IN THE LOWER AND MIDDLE 60S.
ISOLATED CONVECTION CONTINUES TO IMPACT EAST CENTRAL KANSAS AT 07Z
WHERE MID CLOUD HAS AGAIN PREVAILED THROUGH THE NIGHT. UPSTREAM
PRECIPITATION IN NEBRASKA HAS SLOWLY DIMINISHED THOUGH SOME RECENT
REDEVELOPMENT IS NOTED IN NORTHEASTERN SECTIONS OF THAT STATE.
MODELS CONTINUE TO BE CONSISTENT WITH RESPECTABLE MID-SUMMER UPPER
DYNAMICS WORKING THEIR WAY SOUTHEAST INTO EASTERN KANSAS TODAY.
ROCKIES UPPER JET TO DIVE SOUTHEAST INTO CENTRAL KANSAS WHILE
POTENTIAL VORTICITY ANOMALY REACHES NORTHERN KANSAS BY MIDDAY WITH
SOME UPPER LEVEL Q-VECTOR CONVERGENCE RESULTING. THESE FEATURES
REACH THE 2-4C 700MB DEWPOINTS AND THE BULK OF THE
GUIDANCE...INCLUDING THE LAST SEVERAL RUNS OF THE HRRR AND THE 06Z
NAM...EXPANDS PRECIP COVERAGE BY 18Z AS A RESULT. STRENGTH OF
PRECIPITATION IS SOMEWHAT IN QUESTION AS THE EARLY TIMING OF THE
FORCING MAY KEEP STRONG INSOLATION IN CHECK AND MIXED-LAYER CAPE
LIMITED. LARGER SCALE FORCING NOT REACHING EAST CENTRAL KANSAS UNTIL
LATER IN THE DAY WOULD SUGGEST THIS AREA COULD HAVE THE GREATER
POTENTIAL FOR STRONGER STORMS...BUT THIS WILL DEPEND ON HOW LONG THE
ONGOING PRECIP LASTS. HAVE INCREASED POPS WELL ABOVE CLIMO LEVELS
BUT HELD OFF ON ANYTHING ABOVE CHANCE GIVEN COVERAGE UNCERTAINTY.
TEMPERATURES ARE ALSO A CHALLENGE...AND FIRST PERIOD SREF SPREADS
ARE RATHER HIGH. WILL KEEP EASTERN AREAS A FEW DEGREES BELOW
THURSDAYS LEVELS WITH AT LEAST MORE CLOUD EXPECTED IN LIGHT SYNOPTIC
WINDS. PRECIP CONVERGE SHOULD TAPER FROM NORTHWEST TO SOUTHEAST IN
THE LATE AFTERNOON AND EVENING AS THE FORCING MOVES OFF...BUT NOT
EXPECTING A LOT OF CHANGE TO PROFILES...SUGGESTING SOME CHANCE FOR
ELEVATED CONVECTION COULD LINGER AT LEST INTO THE EVENING.
BEYOND TONIGHT...PRECIP CHANCES ARE ON THE LOW SIDE AS THE WESTERN
RIDGE BUILDS INTO THE PLAINS. HARD TO COMPLETELY RULE OUT MORE
EVENTS OF ISOLATED ACTIVITY...BUT HARD TO JUSTIFY A MENTION AT THIS
POINT. CONVERGENCE NEAR A STALLING FRONT IN NEBRASKA APPEARS WEAK AT
BEST FOR SATURDAY AND GETTING ANYTHING TO SURVIVE INTO KANSAS IS
UNLIKELY. THE GFS ATTEMPTS TO BRING A FRONT SOUTH TO NEAR THE KANSAS
BORDER EARLY NEXT WEEK...BUT THE ECMWF KEEPS IT NORTH. MUCH TOO
LITTLE CONFIDENCE FOR A MENTION WITH THIS POSSIBILITY AT THIS POINT.
AS FOR TEMPERATURES...850MB TEMPS WARM A BIT FURTHER SATURDAY WITH
UPPER 90S TO AROUND 100 COMMONPLACE. INCREASED LOW LEVEL SOUTHEAST
FLOW MAY TONE DOWN TEMPS SUNDAY...BUT A MORE WESTERLY COMPONENT
SHOULD PUSH HIGHS BACK UP TO AROUND 100 FOR MUCH OF NEXT WEEK.
HUMIDITIES STILL DONT LOOK TOO BAD...BUT THE APPEARS TO BE SOME
POTENTIAL FOR HEAT HEADLINES DUE TO HEATS PERSISTENCE.
65
&&
.AVIATION...
SHOWERS NEAR KTOP AND KFOE WILL DEPART THE AREA SHORTLY...WITH
SKIES GRADUALLY CLEARING UP. MODEL GUIDANCE SUGGESTS FOG FORMATION
AT THE TERMINALS OVERNIGHT...HOWEVER GIVEN THE DRY ATMOSPHERE IN
THE LOWEST 10KFT WILL OPT TO NOT INCLUDE FOG MENTION FOR TONIGHT.
HOWEVER...WITH THE RAINFALL FROM TODAY THERE IS A POSSIBILITY THAT
SOME SHALLOW GROUND FOG MAY OCCUR...BUT WITH CERTAINTY RATHER LOW
WILL HANDLE THE FOG THREAT WITH FUTURE FORECASTS AND AMENDMENTS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 1206 PM EDT FRI JUL 13 2012
SKIES REMAIN FAIRLY CLEAR OVR MUCH OF THE AREA. MID CLOUDS TRIED TO
MAKE PUSH INTO WESTERN CWA A FEW HOURS AGO BUT FELL APART RAPIDLY.
WV LOOP AND RUC ANALYSIS INDICATES THAT THERE IS A DECENT AMOUNT OF
DRY AIR OVR MUCH OF NORTHEAST AND NORTHERN WISCONSIN AND INTO WESTERN
UPR MICHIGAN. 12Z GRB SOUNDING TURNED UP A K INDEX NEAR 30C BUT THE
WV LOOP INDICATES THIS IS ONLY A VERY SMALL AREA OF HIGHER MOISTURE
LIFTING TOWARD BAY OF GREEN BAY. DELAYED INCREASING CLOUD TREND IN
THE WEST. EVENTUALLY COULD SEE AT LEAST ISOLD SHRA/TSRA FORM IN THE
WEST AS WE PUSH PAST CONVECTIVE TEMPS IN THE MID 80S AND SOME WEAK
FORCING AND MOISTURE ADVECTION EDGES ACROSS THAT AREA OUT AHEAD OF
STRONGER DYNAMICS FM LARGER SCALE TROUGH FM NORTHWEST ONTARIO INTO
NORTHERN MINNESOTA.
SINCE H85 TEMPS HAVE ROSE ANOTHER 1-2C COMPARED TO YDY AND SKY COVER
SHOULD BE MINIMAL FOR MUCH OF THE AREA...HAVE BUMPED UP FCST HIGHS
THIS AFTN TO VALUES A COUPLE DEGREES HIGHER THAN THOSE OBSERVED YDY.
MAIN RESULT WILL BE MANY AREAS PUSHING TOWARD OR JUST PAST THE 90
DEGREE MARK. EVEN SO...SINCE DWPNTS WILL CONTNIUE TO MIX OUT WITH
THE DRIER AIR OVERHEAD WILL NOT BE AS HUMID AS IT COULD BE GIVEN THE
WARMTH. THE DRIER AIR AND A BIT OF A SOUTH WIND WILL OVERALL MAKE FOR A
COMFORTABLE 90 DEGREE DAY.
FINALLY...LOOKING AHEAD FOR TONIGHT AND SATURDAY...CURRENT POPS/WX
ARE GENERALLY ON TRACK. UPPER TROUGH AXIS IS FCST TO BE SQUARELY
OVERHEAD UPR MICHIGAN BY SATURDAY AFTN...SO EXPECT HIGHER COVERAGE
TO SHRA/TSRA BY THAT TIME AS HAS OCCURRED BENEATH THE UPR TROUGH
AXIS THE LAST COUPLE DAYS. H85-H3 WINDS ARE WEAK BENEATH THE TROUGH
AXIS AND GIVEN INCREASING PWATS TOWARD 150 PCT OF NORMAL...SEEMS LIKE
MAIN ISSUE ON SATURDAY WILL BE HEAVY DOWNPOURS. ALREADY SEEING THIS
AS KBDE IN FAR NORTHERN MN THIS MORNING /BENEATH THE TROUGH AXIS/
RECEIVED JUST UNDER 2 INCHES OF RAIN IN LESS THAN 2 HOURS WITH A SLOW
MOVING THUNDERSTORM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT FRI JUL 13 2012
SHORT TERM PATTERN WILL BE DOMINATED BY A 500MB TROUGH CURRENTLY
OVER SRN MANITOBA/ND/NW MN...THAT WILL LATER PHASE WITH AN UPPER LOW
/AND ASSOCIATED TROUGH/ CURRENTLY OVER NRN ALBERTA. AT THE
SFC...CURRENTLY THERE IS A TROUGH JUST E OF THE UPPER TROUGH AXIS
INTO FAR WRN MN...AND HIGH PRESSURE OVER THE ERN SEABOARD. THIS PUTS
IN THE CWA UNDER SW LOW LEVEL FLOW INITIALLY. SHOWERS FROM JUST W OF
LAKE SUPERIOR STRETCHING ALONG THE WI/MN BORDER HAVE BEEN INCREASING
IN COVERAGE EARLY TONIGHT...ALONG A RIBBON OF HIGHER MOISTURE IN THE
WAA REGIME AHEAD OF THE SFC TROUGH.
FOR TODAY...THE SRN UPPER TROUGH WILL PHASE WITH THE NRN UPPER LOW
BY 00Z SAT...DEEPENING THE SRN EXTENT OF THE TROUGH THE AXIS MOVES
TO JUST W OF LAKE SUPERIOR AND ALONG THE WI/MN BORDER...WITH THE SFC
TROUGH ALMOST DIRECTLY BENEATH THE UPPER TROUGH. TRICKY TO SAY WHEN
SHOWERS WILL GET INTO UPPER MI...AS THE RIBBON OF MOISTURE SLOWLY
MOVES E. THE NAM IS ONE OF THE FASTER AND MORE AGRESSIVE MODELS WITH
BRINGING THE MOISTURE INTO WRN UPPER MI THIS AFTERNOON...BUT OUTPUTS
LITTLE QPF AS VER LOW LEVEL WILL BE DRY. PRIOR TO AROUND 21Z
TODAY...IF ANY PRECIP MAKES IT TO THE GROUND IT SHOULD BE FAIRLY
LIGHT. THINK BEST CHANCES FOR WRN UPPER MI TO SEE PRECIP TODAY WILL
BE THIS EVENING WHILE WE STILL HAVE DECENT SFC HEATING AND A
SHORTWAVE INDICATED BY MODELS MOVES IN FROM THE S. 850MB TEMPS OF UP
TO 19C BY LATE IN THE DAY WILL SUPPORT HIGH TEMPS IN THE 80S TO
AROUND 90...WARMEST CENTRAL AND E AWAY FROM LAKE MI.
TONIGHT...THE SFC AND UPPER TROUGHS WILL MOVE INTO FAR WRN UPPER MI
BY 12Z SAT. PRECIP WILL AGAIN BE TRICKY AS MODELS HAVE A HARD TIME
TO DEALING WITH CONVECTIVE LEFTOVERS. ONE THING AGREED ON BY MODELS
IS THAT ERN UPPER MI WILL BE DRIER THAN WRN UPPER MI...SINCE DRY LOW
LEVEL AIR WILL LINGER OVER THE E THROUGH THE NIGHT. SEEMS THE BEST
CHANCES FOR PRECIP WILL BE OVER WRN UPPER MI AND ALONG THE WI
BORDER...WHERE I KEPT CHANCE AND SLIGHT CHANCE POPS...AND THE E
SHOULD BE DRY. OVERALL CONFIDENCE IN OVERNIGHT PRECIP IS LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 456 AM EDT FRI JUL 13 2012
MEDIUM RANGE GUIDANCE IS IN OVERALL DECENT AGREEMENT ON THE BIG
PICTURE FOR NEXT WEEK AS IT PERTAINS TO UPPER MI. SLOW MOVING TROF
PASSING ACROSS THE WRN GREAT LAKES THIS WEEKEND WILL BE FOLLOWED BY
WEAK RIDGING EARLY NEXT WEEK AS WRN CONUS RIDGE EXPANDS EASTWARD.
SHORTWAVE CRUISING ACROSS THE NRN CONUS/SRN CANADA WILL THEN
TRANSLATE TO TROF AMPLIFICATION OVER SE CANADA/NE CONUS MIDWEEK.
THEREAFTER...RIDGE WILL BUILD/EXPAND ACROSS THE CONUS WITH CENTER OF
HOT RIDGE AGAIN SETTING UP OVER THE CNTRL STATES. END RESULT WILL BE
ABOVE NORMAL TEMPS THRU EARLY NEXT WEEK...2 MAYBE 3 DAYS OF MORE
PLEASANT SUMMER WEATHER MIDWEEK AS TROF AMPLIFIES TO THE E...AND
THEN A RETURN TO POTENTIALLY WELL ABOVE NORMAL TEMPS LATE WEEK/NEXT
WEEKEND AS HOT RIDGE EXPANDS OVER THE CNTRL CONUS. PATTERN DOES NOT
LOOK TO FAVOR WELL ORGANIZED PCPN EVENTS. BEST SHOTS FOR PCPN WILL BE
THIS WEEKEND WITH SLOW MOVING TROF AND POSSIBLY SOMETIME LATER
MON/TUE AS COLD FRONT PASSES. DRY DAYS ARE A GOOD BET MIDWEEK AS SFC
HIGH PRES SETTLES ACROSS THE UPPER LAKES...AND THEN RESURGENCE OF
HEAT TOWARD THE UPPER LAKES LATE NEXT WEEK WILL PROBABLY SUPPORT SOME
THREAT OF CONVECTION AT THAT TIME.
AS ALLUDED TO ABOVE...TROF CURRENTLY OVER THE ERN DAKOTAS/WRN MN
WILL SLOWLY MOVE ACROSS THE GREAT LAKES THIS WEEKEND. WITH TROF AXIS
REACHING UPPER MI SAT AND COINCIDING WITH DAYTIME HEATING...
SHRA/TSRA COVERAGE SHOULD BECOME NMRS. CNTRL UPPER MI MAY BE FAVORED
FOR BEST COVERAGE GIVEN MORE IDEAL TIMING OF TROF WITH RESPECT TO
DIURNAL CYCLE AND DUE TO SOME ASSISTANCE FROM LAKE BREEZES. DEEP
LAYER SHEAR IS GENERALLY UNDER 20KT...SO ORGANIZED SVR STORMS ARE
NOT EXPECTED. HOWEVER...IF THERE IS ENOUGH DAYTIME HEATING TO
SIGNIFICANTLY BOOST INSTABILITY...THERE MAY BE ISOLD PULSE TYPE SVR
STORMS SAT AFTN. RELATIVELY SLOW STORM MOVEMENT COULD LEAD TO SOME
LOCALLY HVY RAINFALL.
PCPN SHOULD GRADUALLY END FROM W TO E SAT NIGHT. SINCE MID LEVEL
TROF AXIS WILL BE E OF THE FCST AREA BY SUN MORNING...IT APPEARS SUN
WILL PROBABLY TURN OUT TO BE A DRY DAY. HOWEVER....RETAINED SLIGHT
CHC POPS ACROSS THE SCNTRL/SE AS LAKE BREEZE INTERACTION MIGHT STILL
YIELD ISOLD SHRA/TSRA. MIXING TO AROUND 800MB SUPPORTS MAX TEMPS
UPWARDS OF AROUND 90F AWAY FROM MODEST LAKE BREEZE COOLING.
SHORTWAVE WILL EJECT FROM TROF ALONG THE W COAST SUN NIGHT. IN
RESPONSE TO THE WAVE TRACKING TOWARD SCNTRL CANADA...LOW-LEVEL JET
WILL INCREASE ACROSS THE PLAINS. THIS SHOULD SUPPORT A CLUSTER OF
SHRA/TSRA ON NOSE OF LOW-LEVEL JET AND ALONG EDGE OF CAP ACROSS
ND/SRN SASKACHEWAN INTO NRN MN/SRN MANITOBA. AT THIS TIME... IT
APPEARS LOW-LEVEL JET WILL STILL BE W OF THE AREA BY 12Z MON...SO DO
NOT ANTICIPATE ANY CONVECTION LATE SUN NIGHT...EXCEPT POSSIBLY OVER
WRN LAKE SUPERIOR.
LOW-LEVEL JET SLIDES ACROSS THE AREA MON. THERE IS SOME UNCERTAINTY
ON WHERE THE EDGE OF THE CAP WILL RESIDE...BUT GENERAL CONSENSUS IS
THAT AT LEAST THE NRN/ERN PORTIONS OF THE FCST AREA WILL BE CLOSE
ENOUGH TO WARRANT A MENTION OF SHRA/TSRA. WITH AREA ON THE CAPE
GRADIENT AND UNDER 35-45KT OF DEEP LAYER SHEAR...ORGANIZED SVR
STORMS WILL BE POSSIBLE IF THERE IS CONVECTION. IF THERE IS NO PCPN
AND NOT MUCH CLOUD COVER...TEMPS UNDER WAA SHOULD EASILY RISE INTO
THE LWR 90S IN MOST AREAS AWAY FROM LOCAL COOLING NEAR THE GREAT
LAKES...MAINLY LAKE MI UNDER S TO SW BOUNDARY LAYER FLOW.
COLD FRONT SLIDES ACROSS THE AREA MON NIGHT/TUE MORNING...PROVIDING
A CHC OF SHRA/TSRA. WILL HANG ONTO CHC POPS THRU TUE AFTN GIVEN SOME
UNCERTAINTY IN FRONTAL TIMING. OTHERWISE...COOLER/DRIER MORE
COMFORTABLE AIR MASS WILL BEGIN SPREADING INTO THE AREA TUE. A MORE
PLEASANT SUMMER DAY SHAPING UP FOR WED AS SFC HIGH PRES SETTLES OVER
THE UPPER LAKES. HIGHS SHOULD BE IN THE LWR 70S ALONG LAKE SUPERIOR
TO UPPER 70S/AROUND 80 INLAND WITH DWPTS FALLING THRU THE 50S. IT
SHOULD REMAIN COMFORTABLE THU (DWPTS IN THE 50S)...THOUGH IT WILL
BEGIN TO WARM UP JUST A LITTLE AS RETURN FLOW DEVELOPS ON BACKSIDE
OF DEPARTING HIGH PRES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 147 PM EDT FRI JUL 13 2012
A COLD FRONT/UPPER LOW WILL APPROACH UPPER MICHIGAN LATE THIS
AFTERNOON INTO THIS EVENING WHICH MAY TRIGGER WIDELY SCATTERED SHRA
AND TSRA ACROSS FAR WESTERN UPPER MI INCLUDING IWD AND PERHAPS CMX.
WITH LOSS OF DAYTIME HEATING/INSTABILITY...EXPECT GENERALLY QUIET
CONDITIONS MOST OF TONIGHT. INCREASING SHRA/TSRA CHANCES ARE
EXPECTED LATE TONIGHT THROUGH SATURDAY AS THE UPPER LOW MOVES
OVERHEAD. BASED ON WHAT IS OCCURRING UPSTREAM IN MINNESOTA...BEST
CHANCE OF TSRA WILL BE FM MID MORNING THROUGH THE AFTN HOURS ON
SATURDAY. ALL TAF SITES COULD EXPERIENCE SCT SHRA/TSRA. APPEARS
GREATEST CHANCE FOR TSRA WOULD BE LATE SATURDAY MORNING AT CMX AND
INTO SATURDAY AFTN AT SAW. STORMS COULD DROP HEAVY RAIN WHICH COULD
BRIEFLY RESULT IN IFR OR MVFR CONDITIONS IF A STORM DIRECTLY IMPACTS
ONE OF THE TAF SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT FRI JUL 13 2012
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE REGION WILL SLOWLY GIVE
WAY TO A WEAK TROUGH THAT WILL MOVE THROUGH OVER THE WEEKEND. OUT
AHEAD OF THE TROUGH...S TO SE WINDS MAY REACH 20 KTS IN GUSTS OVR
PORTIONS OF CNTRL AND EAST LAKE SUPERIOR TODAY INTO EARLY TONIGHT.
OTHERWISE...WINDS WILL BE LESS THAN 20 KTS THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK IN WAKE OF THE TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1209 PM EDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 1206 PM EDT FRI JUL 13 2012
SKIES REMAIN FAIRLY CLEAR OVR MUCH OF THE AREA. MID CLOUDS TRIED TO
MAKE PUSH INTO WESTERN CWA A FEW HOURS AGO BUT FELL APART RAPIDLY.
WV LOOP AND RUC ANALYSIS INDICATES THAT THERE IS A DECENT AMOUNT OF
DRY AIR OVR MUCH OF NORTHEAST AND NORTHERN WISCONSIN AND INTO WESTERN
UPR MICHIGAN. 12Z GRB SOUNDING TURNED UP A K INDEX NEAR 30C BUT THE
WV LOOP INDICATES THIS IS ONLY A VERY SMALL AREA OF HIGHER MOISTURE
LIFTING TOWARD BAY OF GREEN BAY. DELAYED INCREASING CLOUD TREND IN
THE WEST. EVENTUALLY COULD SEE AT LEAST ISOLD SHRA/TSRA FORM IN THE
WEST AS WE PUSH PAST CONVECTIVE TEMPS IN THE MID 80S AND SOME WEAK
FORCING AND MOISTURE ADVECTION EDGES ACROSS THAT AREA OUT AHEAD OF
STRONGER DYNAMICS FM LARGER SCALE TROUGH FM NORTHWEST ONTARIO INTO
NORTHERN MINNESOTA.
SINCE H85 TEMPS HAVE ROSE ANOTHER 1-2C COMPARED TO YDY AND SKY COVER
SHOULD BE MINIMAL FOR MUCH OF THE AREA...HAVE BUMPED UP FCST HIGHS
THIS AFTN TO VALUES A COUPLE DEGREES HIGHER THAN THOSE OBSERVED YDY.
MAIN RESULT WILL BE MANY AREAS PUSHING TOWARD OR JUST PAST THE 90
DEGREE MARK. EVEN SO...SINCE DWPNTS WILL CONTNIUE TO MIX OUT WITH
THE DRIER AIR OVERHEAD WILL NOT BE AS HUMID AS IT COULD BE GIVEN THE
WARMTH. THE DRIER AIR AND A BIT OF A SOUTH WIND WILL OVERALL MAKE FOR A
COMFORTABLE 90 DEGREE DAY.
FINALLY...LOOKING AHEAD FOR TONIGHT AND SATURDAY...CURRENT POPS/WX
ARE GENERALLY ON TRACK. UPPER TROUGH AXIS IS FCST TO BE SQUARELY
OVERHEAD UPR MICHIGAN BY SATURDAY AFTN...SO EXPECT HIGHER COVERAGE
TO SHRA/TSRA BY THAT TIME AS HAS OCCURRED BENEATH THE UPR TROUGH
AXIS THE LAST COUPLE DAYS. H85-H3 WINDS ARE WEAK BENEATH THE TROUGH
AXIS AND GIVEN INCREASING PWATS TOWARD 150 PCT OF NORMAL...SEEMS LIKE
MAIN ISSUE ON SATURDAY WILL BE HEAVY DOWNPOURS. ALREADY SEEING THIS
AS KBDE IN FAR NORTHERN MN THIS MORNING /BENEATH THE TROUGH AXIS/
RECEIVED JUST UNDER 2 INCHES OF RAIN IN LESS THAN 2 HOURS WITH A SLOW
MOVING THUNDERSTORM. &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT FRI JUL 13 2012
SHORT TERM PATTERN WILL BE DOMINATED BY A 500MB TROUGH CURRENTLY
OVER SRN MANITOBA/ND/NW MN...THAT WILL LATER PHASE WITH AN UPPER LOW
/AND ASSOCIATED TROUGH/ CURRENTLY OVER NRN ALBERTA. AT THE
SFC...CURRENTLY THERE IS A TROUGH JUST E OF THE UPPER TROUGH AXIS
INTO FAR WRN MN...AND HIGH PRESSURE OVER THE ERN SEABOARD. THIS PUTS
IN THE CWA UNDER SW LOW LEVEL FLOW INITIALLY. SHOWERS FROM JUST W OF
LAKE SUPERIOR STRETCHING ALONG THE WI/MN BORDER HAVE BEEN INCREASING
IN COVERAGE EARLY TONIGHT...ALONG A RIBBON OF HIGHER MOISTURE IN THE
WAA REGIME AHEAD OF THE SFC TROUGH.
FOR TODAY...THE SRN UPPER TROUGH WILL PHASE WITH THE NRN UPPER LOW
BY 00Z SAT...DEEPENING THE SRN EXTENT OF THE TROUGH THE AXIS MOVES
TO JUST W OF LAKE SUPERIOR AND ALONG THE WI/MN BORDER...WITH THE SFC
TROUGH ALMOST DIRECTLY BENEATH THE UPPER TROUGH. TRICKY TO SAY WHEN
SHOWERS WILL GET INTO UPPER MI...AS THE RIBBON OF MOISTURE SLOWLY
MOVES E. THE NAM IS ONE OF THE FASTER AND MORE AGRESSIVE MODELS WITH
BRINGING THE MOISTURE INTO WRN UPPER MI THIS AFTERNOON...BUT OUTPUTS
LITTLE QPF AS VER LOW LEVEL WILL BE DRY. PRIOR TO AROUND 21Z
TODAY...IF ANY PRECIP MAKES IT TO THE GROUND IT SHOULD BE FAIRLY
LIGHT. THINK BEST CHANCES FOR WRN UPPER MI TO SEE PRECIP TODAY WILL
BE THIS EVENING WHILE WE STILL HAVE DECENT SFC HEATING AND A
SHORTWAVE INDICATED BY MODELS MOVES IN FROM THE S. 850MB TEMPS OF UP
TO 19C BY LATE IN THE DAY WILL SUPPORT HIGH TEMPS IN THE 80S TO
AROUND 90...WARMEST CENTRAL AND E AWAY FROM LAKE MI.
TONIGHT...THE SFC AND UPPER TROUGHS WILL MOVE INTO FAR WRN UPPER MI
BY 12Z SAT. PRECIP WILL AGAIN BE TRICKY AS MODELS HAVE A HARD TIME
TO DEALING WITH CONVECTIVE LEFTOVERS. ONE THING AGREED ON BY MODELS
IS THAT ERN UPPER MI WILL BE DRIER THAN WRN UPPER MI...SINCE DRY LOW
LEVEL AIR WILL LINGER OVER THE E THROUGH THE NIGHT. SEEMS THE BEST
CHANCES FOR PRECIP WILL BE OVER WRN UPPER MI AND ALONG THE WI
BORDER...WHERE I KEPT CHANCE AND SLIGHT CHANCE POPS...AND THE E
SHOULD BE DRY. OVERALL CONFIDENCE IN OVERNIGHT PRECIP IS LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 456 AM EDT FRI JUL 13 2012
MEDIUM RANGE GUIDANCE IS IN OVERALL DECENT AGREEMENT ON THE BIG
PICTURE FOR NEXT WEEK AS IT PERTAINS TO UPPER MI. SLOW MOVING TROF
PASSING ACROSS THE WRN GREAT LAKES THIS WEEKEND WILL BE FOLLOWED BY
WEAK RIDGING EARLY NEXT WEEK AS WRN CONUS RIDGE EXPANDS EASTWARD.
SHORTWAVE CRUISING ACROSS THE NRN CONUS/SRN CANADA WILL THEN
TRANSLATE TO TROF AMPLIFICATION OVER SE CANADA/NE CONUS MIDWEEK.
THEREAFTER...RIDGE WILL BUILD/EXPAND ACROSS THE CONUS WITH CENTER OF
HOT RIDGE AGAIN SETTING UP OVER THE CNTRL STATES. END RESULT WILL BE
ABOVE NORMAL TEMPS THRU EARLY NEXT WEEK...2 MAYBE 3 DAYS OF MORE
PLEASANT SUMMER WEATHER MIDWEEK AS TROF AMPLIFIES TO THE E...AND
THEN A RETURN TO POTENTIALLY WELL ABOVE NORMAL TEMPS LATE WEEK/NEXT
WEEKEND AS HOT RIDGE EXPANDS OVER THE CNTRL CONUS. PATTERN DOES NOT
LOOK TO FAVOR WELL ORGANIZED PCPN EVENTS. BEST SHOTS FOR PCPN WILL BE
THIS WEEKEND WITH SLOW MOVING TROF AND POSSIBLY SOMETIME LATER
MON/TUE AS COLD FRONT PASSES. DRY DAYS ARE A GOOD BET MIDWEEK AS SFC
HIGH PRES SETTLES ACROSS THE UPPER LAKES...AND THEN RESURGENCE OF
HEAT TOWARD THE UPPER LAKES LATE NEXT WEEK WILL PROBABLY SUPPORT SOME
THREAT OF CONVECTION AT THAT TIME.
AS ALLUDED TO ABOVE...TROF CURRENTLY OVER THE ERN DAKOTAS/WRN MN
WILL SLOWLY MOVE ACROSS THE GREAT LAKES THIS WEEKEND. WITH TROF AXIS
REACHING UPPER MI SAT AND COINCIDING WITH DAYTIME HEATING...
SHRA/TSRA COVERAGE SHOULD BECOME NMRS. CNTRL UPPER MI MAY BE FAVORED
FOR BEST COVERAGE GIVEN MORE IDEAL TIMING OF TROF WITH RESPECT TO
DIURNAL CYCLE AND DUE TO SOME ASSISTANCE FROM LAKE BREEZES. DEEP
LAYER SHEAR IS GENERALLY UNDER 20KT...SO ORGANIZED SVR STORMS ARE
NOT EXPECTED. HOWEVER...IF THERE IS ENOUGH DAYTIME HEATING TO
SIGNIFICANTLY BOOST INSTABILITY...THERE MAY BE ISOLD PULSE TYPE SVR
STORMS SAT AFTN. RELATIVELY SLOW STORM MOVEMENT COULD LEAD TO SOME
LOCALLY HVY RAINFALL.
PCPN SHOULD GRADUALLY END FROM W TO E SAT NIGHT. SINCE MID LEVEL
TROF AXIS WILL BE E OF THE FCST AREA BY SUN MORNING...IT APPEARS SUN
WILL PROBABLY TURN OUT TO BE A DRY DAY. HOWEVER....RETAINED SLIGHT
CHC POPS ACROSS THE SCNTRL/SE AS LAKE BREEZE INTERACTION MIGHT STILL
YIELD ISOLD SHRA/TSRA. MIXING TO AROUND 800MB SUPPORTS MAX TEMPS
UPWARDS OF AROUND 90F AWAY FROM MODEST LAKE BREEZE COOLING.
SHORTWAVE WILL EJECT FROM TROF ALONG THE W COAST SUN NIGHT. IN
RESPONSE TO THE WAVE TRACKING TOWARD SCNTRL CANADA...LOW-LEVEL JET
WILL INCREASE ACROSS THE PLAINS. THIS SHOULD SUPPORT A CLUSTER OF
SHRA/TSRA ON NOSE OF LOW-LEVEL JET AND ALONG EDGE OF CAP ACROSS
ND/SRN SASKACHEWAN INTO NRN MN/SRN MANITOBA. AT THIS TIME... IT
APPEARS LOW-LEVEL JET WILL STILL BE W OF THE AREA BY 12Z MON...SO DO
NOT ANTICIPATE ANY CONVECTION LATE SUN NIGHT...EXCEPT POSSIBLY OVER
WRN LAKE SUPERIOR.
LOW-LEVEL JET SLIDES ACROSS THE AREA MON. THERE IS SOME UNCERTAINTY
ON WHERE THE EDGE OF THE CAP WILL RESIDE...BUT GENERAL CONSENSUS IS
THAT AT LEAST THE NRN/ERN PORTIONS OF THE FCST AREA WILL BE CLOSE
ENOUGH TO WARRANT A MENTION OF SHRA/TSRA. WITH AREA ON THE CAPE
GRADIENT AND UNDER 35-45KT OF DEEP LAYER SHEAR...ORGANIZED SVR
STORMS WILL BE POSSIBLE IF THERE IS CONVECTION. IF THERE IS NO PCPN
AND NOT MUCH CLOUD COVER...TEMPS UNDER WAA SHOULD EASILY RISE INTO
THE LWR 90S IN MOST AREAS AWAY FROM LOCAL COOLING NEAR THE GREAT
LAKES...MAINLY LAKE MI UNDER S TO SW BOUNDARY LAYER FLOW.
COLD FRONT SLIDES ACROSS THE AREA MON NIGHT/TUE MORNING...PROVIDING
A CHC OF SHRA/TSRA. WILL HANG ONTO CHC POPS THRU TUE AFTN GIVEN SOME
UNCERTAINTY IN FRONTAL TIMING. OTHERWISE...COOLER/DRIER MORE
COMFORTABLE AIR MASS WILL BEGIN SPREADING INTO THE AREA TUE. A MORE
PLEASANT SUMMER DAY SHAPING UP FOR WED AS SFC HIGH PRES SETTLES OVER
THE UPPER LAKES. HIGHS SHOULD BE IN THE LWR 70S ALONG LAKE SUPERIOR
TO UPPER 70S/AROUND 80 INLAND WITH DWPTS FALLING THRU THE 50S. IT
SHOULD REMAIN COMFORTABLE THU (DWPTS IN THE 50S)...THOUGH IT WILL
BEGIN TO WARM UP JUST A LITTLE AS RETURN FLOW DEVELOPS ON BACKSIDE
OF DEPARTING HIGH PRES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 729 AM EDT FRI JUL 13 2012
VFR CONDITIONS ARE GENERALLY EXPECTED ACROSS ALL SITES FOR THE NEXT
24 HOURS. A COLD FRONT/UPPER DISTURBANCE WILL APPROACH UPPER
MICHIGAN LATE THIS AFTERNOON INTO THIS EVENING WHICH MAY TRIGGER
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON ACROSS FAR
WESTERN UPPER MI INCLUDING IWD. THIS COULD ALLOW FOR BRIEF IFR
CONDITIONS AT IWD AFT 22Z TODAY...BUT THERE IS NOT ENOUGH CONFIDENCE
TO INCLUDE IN THE TERMINAL AT THIS TIME. CONFIDENCE ON PRECIP IS
LOW...ESPECIALLY AT SAW AND CMX WHICH WILL BE MORE ON THE FRINGES OF
WHERE THE BEST PRECIP CHANCES ARE. FOR CMX AND SAW...JUST PUT VCSH
IN THE FORECAST AT THIS TIME GIVEN THE UNCERTAINTY. OTHERWISE...S-SW
WINDS WILL GUST TO AROUND 20 KT AHEAD OF THE COLD FRONT ON FRIDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT FRI JUL 13 2012
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE REGION WILL SLOWLY GIVE
WAY TO A WEAK TROUGH THAT WILL MOVE THROUGH OVER THE WEEKEND. OUT
AHEAD OF THE TROUGH...S TO SE WINDS MAY REACH 20 KTS IN GUSTS OVR
PORTIONS OF CNTRL AND EAST LAKE SUPERIOR TODAY INTO EARLY TONIGHT.
OTHERWISE...WINDS WILL BE LESS THAN 20 KTS THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK IN WAKE OF THE TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1236 PM CDT FRI JUL 13 2012
.AVIATION... /18Z TAF ISSUANCE/
TWO CONCERNS THIS TAF CYCLE. THE FIRST IS SHRA/TSRA CHANCES THIS
AFTERNOON AND EVENING WHILE THE OTHER IS MVFR OR LOWER
CEILINGS/VISIBILITIES IN FOG LATE TONIGHT. EARLY THIS AFTERNOON
SHOWERS WERE BEGINNING TO INCREASE IN COVERAGE BETWEEN KAXN AND
KSTC. THIS IS ALONG THE SURFACE FRONT AND UPPER LOW/TROF ALOFT.
SHORT TERM GUIDANCE IS IN PRETTY GOOD AGREEMENT THAT ACTIVITY
SHOULD CONTINUE TO INCREASE IN COVERAGE THIS AFTERNOON AND SPREAD
SOUTHEAST. KMSP...KRNH AND KEAU SEEM TO HAVE THE BEST CHANCE FOR
SHRA/TSRA BUT CONFIDENCE IS LOW ON COVERAGE AT ANY ONE SITE.
THEREFORE...CONTINUED VCSH/VCTS. THE WESTERN TERMINALS MAY SEE A
BRIEF SHOWER AS WELL WITH VCSH INDICATED AT KAXN AND KRWF. SCT-
BKN040-050 WILL BE COMMON THIS AFTERNOON WITH A MID LEVEL CEILING
ABOVE. WINDS THIS AFTERNOON WILL BE SOUTH AT NEAR 10 KNOTS FROM
KMSP ON EAST WITH SOUTHWEST TO WEST WINDS LESS THAN 10 KNOTS TO
THE WEST.
THE FRONTAL BOUNDARY ACROSS WESTERN MN WILL WASH OUT TONIGHT
ACROSS WESTERN WI AND SOUTHERN MN. LOW LEVEL MOISTURE COMBINED
WITH LIGHT WINDS AND THE POTENTIAL FOR ADDED GROUND MOISTURE FROM
AFTERNOON/EVENING SHOWERS SHOULD LEAD TO MVFR OR LOWER CONDITIONS
AT KRNH AND KEAU DURING THE LATE NIGHT HOURS. CONFIDENCE IS PRETTY
HIGH AND INDICATED MVFR OR LESS AFTER 08Z. IT/S QUITE CONCEIVABLE
THAT THE FOG COULD DEVELOP AS EARLY AS 04Z-06Z...DEPENDING ON HOW
MUCH RAIN OCCURS IN THE EVENING ALONG WITH THE CLEARING TREND.
KMSP...SHOWERS POSSIBLE AFTER 20Z WITH THUNDER CHANCES INCREASING
AFTER 22Z AND LASTING INTO THE EARLY EVENING. SMALL THREAT FOR
5-6SM IN FOG/HAZE TOWARD DAYBREAK SATURDAY WITH LIGHT WINDS.
/OUTLOOK/
SATURDAY AFTERNOON/NIGHT...VFR. WINDS NORTHERLY AT 5 TO 10 KTS.
SUNDAY...VFR. WINDS SE AT 5-15 KTS.
MONDAY...VFR. WINDS S-SW 10-20 KTS.
&&
.DISCUSSION... /ISSUED 325 AM CDT FRI JUL 13 2012/
THE UPCOMING SEVEN DAYS LOOKS TO BE RELATIVELY QUIET FROM A PCPN
PERSPECTIVE... WITH THE BEST CHANCES BEING OVER THE NEXT 24
HOURS... BUT IT STARTING TO LOOK MORE INTERESTING WITH RESPECT TO
A FEW CHANCES FOR EXCESSIVE HEAT. IN THE BIG PICTURE... THE LATEST
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW A FAIRLY
HEALTHY SHORTWAVE MOVING THROUGH THE REGION AT THE CURRENT TIME...
WITH TWO MAIN PV ANOMALIES AND AREAS OF ENHANCED FORCING. ONE CAN
BE SEEN DROPPING SOUTHEAST THROUGH SOUTHEAST SOUTH DAKOTA AT THE
CURRENT TIME... AND IS HELPING TO ENHANCE THE PCPN OUT AHEAD OF IT
OVER THE SOUTHERN PART OF MINNESOTA. THE SECOND ANOMALY IS OVER
NORTHEAST NORTH DAKOTA... AND IS SLOWLY SLIDING EAST WITH TIME...
AND HELPING TO KEEP SOME PCPN GOING IN THAT AREA. ZOOMING OUT...
AN AMPLIFIED RIDGE REMAINS OVER THE WESTERN CONUS... WITH AN UPPER
TROUGH OVER THE PACIFIC NORTHWEST. THE GENERAL THEME OVER THE NEXT
24 TO 36 HOURS WILL BE FOR THE SHORTWAVE CURRENTLY TO OUR WEST TO
DROP SLOWLY SOUTHEAST AND HELP PUSH THE SURFACE TROUGH/FRONT
THROUGH THE AREA TODAY THROUGH SATURDAY... BRINGING CHANCES FOR
SHRA/TSRA TO THE AREA. AFTER THAT WE WILL SEE THE RIDGE OVER THE
ROCKIES BUILD INTO THE AREA... AND BRING INCREASINGLY WARM
TEMPERATURES INTO THE AREA THROUGH MONDAY. WE SHOULD THEN SEE SOME
BRIEF DEPRESSION IN THE UPPER HEIGHTS OVER THE AREA... BUT BY THE
MIDDLE OF THE WEEK THE UPPER RIDGE LOOKS TO RE-AMPLIFY OVER THE
CENTER OF THE COUNTRY. BY THE END OF THE WEEK THERE IS A FAIR
AMOUNT OF DISAGREEMENT BETWEEN THE GFS AND ECMWF... WITH THE GFS
DROPPING AND UPPER TROUGH INTO EASTERN CANADA AND DEVELOPING
NORTHWEST FLOW OVER US... WHILE THE ECMWF CONTINUES TO BUILD THE
UPPER RIDGE AND WOULD REALLY HAVE US COOKING BY THE END OF THE
WEEK. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH THE IDEA THE PAST
FEW RUNS... SO IT WILL CERTAINLY BE SOMETHING TO MONITOR. AT THIS
POINT... A VERY WARM MONDAY LOOKS TO BE A GOOD BET... WITH ANOTHER
PERHAPS WARMER SPAN OF WEATHER DEVELOPING BY THE END OF THE WEEK
THROUGH THE FOLLOWING WEEKEND.
FOR TODAY... WE SHOULD CONTINUE TO SEE SOME SCATTERED SHRA/TSRA
MIGRATE SLOWLY EAST THROUGH THE DAY AS THE SURFACE TROUGH PUSHES
EAST AHEAD OF UPPER WAVE. THE LOW LEVEL CONVERGENCE/UPPER LEVEL
DIVERGENCE COUPLET LOOKS TO PUSH EAST OF THE I-35 CORRIDOR BY THIS
AFTERNOON... SO THE BEST CHANCE FOR MORE WIDESPREAD PCPN WILL BE
OVER THE EASTERN PART OF THE CWFA... ALONG WITH THE MAIN POTENTIAL
FOR ANY SEVERE STORMS. HOWEVER... WITH THE UPPER TROUGH MOVING SO
SLOWLY TODAY AND TONIGHT... WE COULD CERTAINLY SEE SOME LINGERING
SHRA BEHIND THE SURFACE BOUNDARY BENEATH THE UPPER PV ANOMALY AND
ASSOCIATED MID-LEVEL COLD POOL. IN TERMS OF SEVERE WEATHER
POTENTIAL... THINGS STILL LOOK LIKE THE HAVE THE PAST SEVERAL
DAYS... WITH DECENT MLCAPE VALUES AOA 1500 J/KG TODAY INTO THIS
EVENING... BUT MEAGER DEEP LAYER AND LOW LEVEL SHEAR. SO... STILL
LOOKS LIKE WE/LL MAINLY BE DEALING WITH MULTI-CELL PULSE STORMS...
WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL AND PERHAPS
SOME DOWNBURST WIND GUSTS GIVEN EXPECTED SURFACE DELTA THETA-E
VALUES AOA 25K. SOME PCPN COULD LINGER OVER THE EASTERN PART OF
THE AREA FOR A GOOD PART OF SATURDAY GIVEN THE SLOW EASTWARD
MIGRATION OF THE UPPER WAVE. HOWEVER... BY SATURDAY NIGHT WE
SHOULD SEE UPPER RIDGING WORK BACK ACROSS THE AREA... WITH A
SURFACE RIDGE NOSING DOWN FROM CENTRAL CANADA AS WELL. FAIRLY
ROBUST RETURN FLOW LOOKS TO SETUP SUNDAY AFTERNOON... PUSHING THE
WARM FRONT WELL NORTH THROUGH THE AREA BY EVENING. WE WILL THEN
SEE LOW PRESSURE ORGANIZE OVER THE HIGH PLAINS SUNDAY NIGHT INTO
MONDAY... WITH THE WARM SECTOR BECOME WELL ESTABLISHED OVER OUR
AREA. CHANCES FOR PCPN ON MONDAY AS THIS LOW PUSHES EAST LOOK LIKE
THEY WILL BE CONFINED TO THE NORTH OF OUR AREA CLOSER TO THE WARM
FRONTAL BOUNDARY AS 700MB TEMPERATURES AOA 12C ENCOMPASS ALL OF
CENTRAL AND SOUTHERN MINNESOTA. THE COLD FRONT WILL EVENTUALLY
DROP SOUTH THROUGH THE AREA MONDAY NIGHT AND TUESDAY AS THE
SURFACE LOW MOVES OFF INTO THE GREAT LAKES... AND WE COULD SEE
SOME SHRA/TSRA DROP THROUGH THE AREA AT THAT TIME AS WE FINALLY
PUSH THE CAP SOUTH OF THE REGION.
A BRIEF SHOT OF COOLER AND DRIER AIR LOOKS TO WORK INTO THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY AS 500MB HEIGHTS FALL AND A DECENT
SURFACE HIGH SETTLES SOUTH INTO THE AREA FROM CANADA. HOWEVER...
AS WE/VE SEEN MOST OF THE SUMMER... WE WON/T HAVE NEAR OR SLIGHTLY
BELOW NORMAL TEMPERATURES REMAINING OVER THE AREA FOR TOO LONG...
AND RETURN FLOW WILL SET BACK UP BY THURSDAY. AS SOUTHWESTERLY
FLOW DEVELOPS AND STARTS TO BRING WARMER TEMPERATURES AND MOISTURE
BACK INTO THE AREA... WE COULD SEE SOME PCPN DEVELOP OVER THE
AREA... SO INCLUDED SOME POPS ON THURSDAY TO ACCOUNT FOR THAT
SCENARIO. AFTER THURSDAY... AND BEYOND THE CURRENT FORECAST
PERIOD... IS THE POINT AT WHICH THE GFS AND ECMWF START TO
DIVERGE QUITE A BIT... AND THERE IS A FAIR AMOUNT OF SPREAD IN THE
GEFS AT THIS POINT AS WELL... WITH SOME MEMBERS SUGGESTING
SOLUTIONS CLOSER TO THAT OF THE ECMWF. IN A NUTSHELL... THE ECMWF
REALLY BUILDS THE UPPER RIDGE OVER THE CENTRAL CONUS AND INTO
SOUTHERN CANADA... WHILE THE GFS HOLDS A DEEP UPPER TROUGH OVER
EASTERN CANADA... AND MANAGES TO KEEP THE UPPER RIDGE AT BAY TO
OUR WEST. SHOULD THINGS PAN OUT AS THE ECMWF SUGGESTS... WE COULD
BE LOOKING AT A PROLONGED SPELL OF WELL ABOVE NORMAL TEMPERATURES
FROM THE END OF THE WEEK INTO THE FIRST PART OF THE FOLLOWING
WEEK.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/TRH
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
533 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 421 PM CDT FRI JUL 13 2012
OUTFLOW DOMINATED CONVECTION CONTINUES TO STEADILY REDEVELOP
SOUTHEAST TOWARD BEST SURFACE CONVERGENCE. BELIEVE THIS TREND WILL
CONTINUE THIS EVENING WITH SCATTERED STORMS PROPOGATING/DEVELOPING
AS FAR SOUTHEAST AS THE ST. LOUIS METROPOLITAN AREA BY DUSK.
LOSS OF DIURNAL INSTABILITY WILL CAUSE COVERAGE OF CONVECTION TO
RAPIDLY DECREASE AFTER SUNSET...BUT LIKE THE PAST FEW
NIGHTS...ISOLATED SHOWERS AND STORMS COULD PERCOLATE INTO THE
OVERNIGHT HOURS.
CVKING
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 527 PM CDT FRI JUL 13 2012
LINE OF SCATTERED THUNDERSTORMS FROM CENTRAL MISSOURI TO WEST
CENTRAL ILLINOIS HAS PRODUCED QUITE AN OUTFLOW THAT IS MOVING
SOUTHEAST TOWARD THE ST. LOUIS METRO TAF SITES. THIS WILL SWING
WINDS AROUND TO THE NORTHWEST WITH GUSTS TO 25KT AROUND 00Z.
COULD SEE THUNDERSTORMS REDEVELOP ALONG THIS BOUNDARY AND HAVE
INCLUDED A TEMPO FOR AN HOUR TO ACCOUNT FOR THIS. OF COURSE THIS
WILL BE NOWCASTED WITH LATEST RADAR TRENDS.
CONVECTION SHOULD WEAKEN WITH LOSS OF DAYTIME HEATING AFTER
SUNSET...ALTHOUGH A FEW SHOWERS COULD LINGER GIVEN VICINITY OF
WEAK MID/UPPER LEVEL TROF. WIND WILL BE LIGHT AND VARIABLE OVERNIGHT.
HAVE A RENEWED CHANCE OF SCATTERED CONVECTION TOMORROW AFTERNOON
FOR ST. LOUIS METRO TAF SITES AS 500MB SHEAR AXIS IS FORECAST TO
BE OVERHEAD. HAVE HANDLED THIS THREAT WITH A PROB30 GROUP.
SPECIFICS FOR KSTL...
EXPECT OUTFLOW BOUNDARY TO IMPACT TERMINAL AROUND 00Z WITH A WIND
SHIFT TO THE NORTHWEST AND GUSTS TO 25KT. ALSO WILL BE WATCHING TO
SEE IF THUNDERSTORMS CAN REDEVELOP ALONG THIS BOUNDARY.
OTHERWISE...VFR CONDITIONS EXPECTED OVERNIGHT WITH WINDS BECOMING
LIGHT AND VARIABLE. A RENEWED THREAT OF THUNDERSTORMS TOMORROW
AFTERNOON...BUT COVERAGE WILL REMAIN SCT...SO HAVE ONLY INCLUDED
A PROB30 GROUP AT THIS TIME.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
427 PM CDT FRI JUL 13 2012
.UPDATE...
ISSUED AT 421 PM CDT FRI JUL 13 2012
OUTFLOW DOMINATED CONVECTION CONTINUES TO STEADILY REDEVELOP
SOUTHEAST TOWARD BEST SURFACE CONVERGENCE. BELIEVE THIS TREND WILL
CONTINUE THIS EVENING WITH SCATTERED STORMS PROPOGATING/DEVELOPING
AS FAR SOUTHEAST AS THE ST. LOUIS METROPOLITAN AREA BY DUSK.
LOSS OF DIURNAL INSTABILITY WILL CAUSE COVERAGE OF CONVECTION TO
RAPIDLY DECREASE AFTER SUNSET...BUT LIKE THE PAST FEW
NIGHTS...ISOLATED SHOWERS AND STORMS COULD PERCOLATE INTO THE
OVERNIGHT HOURS.
CVKING
&&
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1235 PM CDT FRI JUL 13 2012
UPPER LEVEL SYSTEM IS GENERATING SCATTERED STORMS ACROSS NORTHEAST
MISSOURI/WEST CENTRAL ILLINOIS. SOME ISOLATED SHOWERS ARE POPPING
UP ON RADAR AS FAR SOUTH AS CENTRAL MISSOURI AT THIS TIME AS WELL.
THINK STORMS WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS
CENTRAL AND NORTHEAST MISSOURI AS WELL AS WEST CENTRAL ILLINOIS...PRODUCING
OCCASIONAL DOWN BURSTS WITH GUSTS TO 30-40KTS AND ISOLATED POCKETS
OF IFR IN HEAVY RAIN. ELSEWHERE...ISOLATED SHOWERS OR
THUNDERSTORMS WILL BE POSSIBLE. VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE.
SPECIFICS FOR KSTL...
UPPER LEVEL SYSTEM IS PRODDING THUNDERSTORMS NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CAN`T TOTALLY RULE OUT A THUNDERSTORM AT
LAMBERT...ESPECIALLY LATER IN THE AFTERNOON/EARLY EVENING.
HOWEVER...CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT
THIS TIME. OTHERWISE...VFR FLIGHT CONDITIONS ARE EXPECTED TO
PREVAIL. THERE WILL BE ANOTHER CHANCE FOR STORMS SATURDAY AFTERNOON.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
253 PM CDT FRI JUL 13 2012
.SHORT TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TONIGHT)
SCATTERED CONVECTION HAS DEVELOPED ACROSS THE NWRN HALF OF THE CWA
AHEAD OF A PV ANOMALY THAT WAS LOCATED OVER IA PER WATER VAPOR
IMAGERY AND RAP 1.5 PVU FIELDS. MAINLY PULSE-TYPE THUNDERSTORMS ARE
EXPECTED DUE TO WEAK SHEAR COMBINED WITH LITTLE CINH AND A FEW
THOUSAND J/KG OF CAPE. DRY SUBCLOUD LAYER AND A WELL-MIXED
BOUNDARY LAYER WILL ONCE AGAIN SUPPORT OCCASIONAL DOWNBURSTS WHEN
THE CORES OF THE STRONGEST STORMS COLLAPSE HOWEVER WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. PCPN COVERAGE SHOULD
DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING
HOWEVER A FEW AREAS OF ELEVATED CONVECTION MIGHT CONTINUE TO
PERCOLATE OVERNIGHT AS THE SHORTWAVE MOVES INTO NRN MO.
KANOFSKY/CARNEY
&&
.LONG TERM...
ISSUED AT 248 PM CDT FRI JUL 13 2012
(TOMORROW THROUGH NEXT THURSDAY)
VORT MAX MOVING ACROSS THE UPPER MIDWEST AND ITS ASSOCIATED SFC
TROF WILL PROVIDE BOTH A SOURCE OF LARGE SCALE LIFT AND A LOW
LEVEL FOCUSING MECHANISM FOR SCT TSRA/SHRA TOMORROW. GENERALLY
PULSE-TYPE THUNDERSTORMS ARE EXPECTED DUE TO WEAK SHEAR. ISOLATED
DIURNAL PCPN MAY REDEVELOP AND LINGER ACROSS THE SERN HALF OF THE
CWA ON SUN AND MON AS THE TROF SETTLES SEWD AND THE ELONGATED
VORTICITY AXIS SHEARS OUT.
A GRADUAL WARMING TREND IS EXPECTED OVER THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE BUILDS EWD. H85 TEMPERATURES OF 20-24 DEG C WOULD
SUPPORT AFTN HIGHS RANGING FROM THE MID 90S TO NEAR THE CENTURY
MARK. THE CENTRAL REGION ALLBLEND INITIALIZATION REMAINS
CONTAMINATED BY INCORRECT GFS OUTPUT /NCEP STAFF CONTINUE TO
TROUBLESHOOT BUT HAVE NOT YET IDENTIFIED THE SOURCE OF THE
PROBLEM/ THEREFORE I DEVIATED SIGNIFICANTLY FROM THE RECOMMENDED
INITIALIZATION TO REDUCE POPS AND RAISE TEMPS ON DAYS 4-7. A WEAK
SFC FRONT WILL APPROACH THE CWA ON WED/THU AND MOISTURE POOLING
AHEAD OF THE FRONT COULD DRIVE HEAT INDEX READINGS OVER 105 DEG F
IN SOME AREAS. ISOLATED TO SCATTERED THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE EXTENDED PD HOWEVER THERE ARE NO STRONG
SIGNALS TO SUPPORT HIGHER THAN SCHC POPS ACROSS MO/IL WHICH
REMAINS IN A MODERATE TO SEVERE DROUGHT.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1235 PM CDT FRI JUL 13 2012
UPPER LEVEL SYSTEM IS GENERATING SCATTERED STORMS ACROSS NORTHEAST
MISSOURI/WEST CENTRAL ILLINOIS. SOME ISOLATED SHOWERS ARE POPPING
UP ON RADAR AS FAR SOUTH AS CENTRAL MISSOURI AT THIS TIME AS WELL.
THINK STORMS WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS
CENTRAL AND NORTHEAST MISSOURI AS WELL AS WEST CENTRAL ILLINOIS...PRODUCING
OCCASIONAL DOWN BURSTS WITH GUSTS TO 30-40KTS AND ISOLATED POCKETS
OF IFR IN HEAVY RAIN. ELSEWHERE...ISOLATED SHOWERS OR
THUNDERSTORMS WILL BE POSSIBLE. VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE.
SPECIFICS FOR KSTL...
UPPER LEVEL SYSTEM IS PRODDING THUNDERSTORMS NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CAN`T TOTALLY RULE OUT A THUNDERSTORM AT
LAMBERT...ESPECIALLY LATER IN THE AFTERNOON/EARLY EVENING.
HOWEVER...CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT
THIS TIME. OTHERWISE...VFR FLIGHT CONDITIONS ARE EXPECTED TO
PREVAIL. THERE WILL BE ANOTHER CHANCE FOR STORMS SATURDAY AFTERNOON.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPOKANE WA
305 PM PDT Fri Jul 13 2012
.SYNOPSIS...
Warm and increasingly humid conditions are expected over the
Inland Northwest through the weekend as a slow-moving upper level
low tracks through the region. this air mass will contribute to a
chance of thunderstorms on both Saturday and Sunday. Some of the
storms could produce locally heavy rains and possibly some large
hail. the low will track out of the region late Sunday night or
Monday followed by Seasonably with slight chances for thunderstorms.
&&
.DISCUSSION...
Tonight: Upper level low pressure system is spinning along coastal
WA this afternoon. This is bring up monsoonal moisture from the
Desert Southwest. This moisture is expected to push into our
southeastern zones tonight. However, the more immediate threat
will be surface based convection that is expected to develop
during the late afternoon hours. First we need to break through
the cap to release what is potentially a considerable amount of
convective potential energy (CAPE). The strongest CAPE values of
up to 2000 J/KG is located across the northern mountains with
around 20-40 J/KG of convective inhibition (CIN) that has capped
the atmosphere. South of a line from southern Kootenai County to
Moses Lake will be significantly more CIN that will likely not get
broken through the evening hours. The HRRR model shows Some
convection begin to develop during the afternoon or early evening
hours along and north of a line from Coeur d`Alene, Wilbur and to
Moses Lake. This convection will move northward with potential
risks including hail (potentially some sever in size), gusty
outflow winds and cloud to ground lightning strikes.
During the overnight hours, the monsoonal moisture moving
northward will being to spread across our southeastern zones.
Upper level laps rates will become increasingly more unstable
through the night into tomorrow morning north and westward.
Water vapor satellite imagery shows an upper level wave at the
base of the low pressure system, currently across southwestern WA
into western OR. This short wave will continue to rotate around
the low in a counter-clockwise fashion where it is expected to
swing around into southeast WA by the early morning hours tomorrow
morning. This short wave will provide the lift that will kick off
more widespread thunderstorm activity. /SVH
Saturday...the closed upper low currently over NW WA will remain fixed
over the region at least through Saturday afternoon. Models are in
very good agreement that the low will dip slowly SE during the
next 24 hrs...centering itself near The Dalles. As the low moves
toward this area...it will begin to pool of monsoonal moisture
currently over southern Idaho northward into much of our forecast
area. This will result in increasing chances of precipitation
through the day especially for locations north and east of the
center of the low. Model guidance has been fairly wishy-washy on
where to place the heaviest rain...but it should be co-located
where we expected the greatest upper level difluence...NE WA/N ID
and near the core of the low near the Cascades. Model stability
parameters would place the greatest risk of thunderstorms along a
theta-e ridge axis wrapping around the top of the low...or from
the central ID Panhandle through the northern tier of WA and into
the Cascades. We cannot entirely rule out severe thunderstorms
based on CAPE values ranging from 1000-2000 j/kg with much weaker
CIN or convective caps than what we are seeing today...however
shear values away from the low are very weak.
By Sunday...the low is only expected to move into the Blue Mts before
opening up into a trough during the afternoon. This will result in
likely showers and thunderstorms across the eastern third of WA
and all of N Idaho through early afternoon. Then yet another
strong upper level low tracks into the nw WA by late in the day.
This low will likely destabilize the Cascades and result in
another round of thunderstorms for much of the area. Heavy rains
will again be possible.
By Monday the second low is expected to meander slowly
s-sw...through SW WA/NW OR which should lessen the chance for
widespread convection for locations north of i90 and keep the risk
of thunder going elsewhere.
Temperatures forecasts over the next several days will prove a
difficult task as much will depend on how widespread the convection
becomes and what areas are impacted. Locations which see full
sunshine will continue to see daytime readings in the 90s...while
locations which see little if any sun could conceivably see highs
in the mid 70s to lower 80s. fx
Monday Night through Friday: No significant changes were made to
the extended range part of the fcst, which keeps the upper low
nearly stationary over the Pacific Nw through Wed. The recent
trend in model guidance has the ECMWF becoming increasingly more
aligned with the GFS the last couple runs. However...the ECMWF was
the quickest with ejecting this stalled upper low NE across the
region than the GFS by mid weak. Now it`s the GFS that has the
faster ejection of the low, pushing its core NE through Oregon and
Wa Wed and Wed Nt. A nearly non-existent upper trough on the ECMWF
will dig south down the BC coast Wed Nt. These two models are
nearly 180 degrees out of phase with this digging 500 mb low at
this point...with the GFS much stronger, and certainly a more
effective kicker/ejector of the stalled low. That said, we
continued with a very conservative approach to making any big
changes in the fcst based on the high level of uncertainty caused
by the above mentioned differences. So, we did not go with a wet
fcst for Wed Nt per the GFS. Leaning heavily toward a pattern
recognition approach, we kept at least isolated rain showers and
thunderstorms in nearly every period of the fcst. bz
&&
.AVIATION...
18Z TAFS: Upper level low pressure system spinning over southwestern
WA will continue to bring the risk for thunderstorms through
Saturday afternoon. A wave rotating around the low into the Cascades
will continue to generate a line of elevated thunderstorms into the
early afternoon hours. There is a lot of uncertainty as far as where
and how much surface based convection we will see later this
afternoon. Models continue to show strong uncapped instability
across the Cascades over into the Okanogan Highlands, as well as
over into the Northern Panhandle. This is where we expect the best
chances for afternoon thunderstorms to develop with the potential
for a few strong storms. KEAT and more so KMWH will be on the
southern fringe of this convection and may see a thunderstorm or two
this afternoon before this activity lifts northward this evening. By
tonight, we will shift to an elevated threat of thunderstorms around
03Z around the KLWS and KPUW taf sites then continuing to shift
northward and westward into KGEG, KSFF, KCOE and possibly KMWH by
the lat nighttime hours. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 68 87 65 81 60 84 / 30 40 50 70 50 20
Coeur d`Alene 66 86 62 76 58 84 / 50 50 60 70 50 20
Pullman 64 86 61 82 58 83 / 50 40 50 70 30 20
Lewiston 71 94 70 91 66 92 / 50 30 50 70 20 10
Colville 64 89 62 79 60 87 / 50 60 50 70 60 30
Sandpoint 63 82 58 76 55 82 / 60 70 50 70 50 30
Kellogg 64 83 60 76 56 84 / 90 70 60 80 50 30
Moses Lake 67 93 66 92 62 89 / 20 40 30 30 20 20
Wenatchee 69 93 70 89 65 88 / 30 30 30 30 20 20
Omak 67 95 66 87 63 89 / 50 60 30 50 50 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Red Flag Warning until 5 PM PDT Sunday for East Washington
Central Cascade Valleys (Zone 677)-East Washington Northern
Columbia Basin (Zone 673)-East Washington Okanogan/Methow
Valleys (Zone 684)-East Washington South Central Cascade
Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1257 PM PDT Fri Jul 13 2012
.SYNOPSIS...
Warm and increasingly humid conditions are expected over the
Inland Northwest today and tomorrow. Showers and thunderstorms
will bring the potential for locally heavy rain. Some spots could
receive torrential rains on Saturday afternoon and Saturday
evening under slow moving thunderstorms. The slow moving storm
system responsible for the humid and stormy conditions will move
out of the region by Sunday night. Seasonably warm conditions are
expected next week with slight chances for thunderstorms.
&&
.DISCUSSION...
A quick update to the forecast for this afternoon. A tightly wound
short wave rotating around the upper level low pressure system has
shifted the elevated thunderstorm threat into the east slopes of
the northern Cascades. Our attention is now focusing on the
potential for surface based convection. Models continue to show
uncapped energy to be tapped into from the northern portion of the
Moses Lake Area, rotating clockwise around the northern portions
of the Spokane Area and into the Central Panhandle Mountains.
Visible satellite imagery does not show any cumulus development
through 1245 PM, which indicates at least a weak cap that still
needs to be overcome. The HRRR model suggests that we will see
this cap get broken around 400 PM with thunderstorms developing
across the Moses Lake Area, Waterville Plateau and Spokane Area.
Oddly enough, this model does not develop any convection over the
mountains initially. This is contrary to what is expected, thus I
do not have a lot of confidence in the placement of the initial
convection. We are going with convection to develop over the
higher terrain later this afternoon with some isolated cells
possible over the northern portion of the basin. LAPS data shows
CAPE values of up to 2000 J/KG with a convective inhibition of
around 20-50 J/KG across the northern mountains. Once this cap
gets broken, I expect isolated to scattered thunderstorms to
develop. Shear between 0-6 km is not strong, but will be enough to
support supercells with the large amount of energy that is
available to be tapped into. Any thunderstorms that develop will
be capable of producing at least penny size hail stones with some
isolated severe hail possible as well. /SVH
&&
.AVIATION...
18Z TAFS: Upper level low pressure system spinning over southwestern
WA will continue to bring the risk for thunderstorms through
Saturday afternoon. A wave rotating around the low into the Cascades
will continue to generate a line of elevated thunderstorms into the
early afternoon hours. There is a lot of uncertainty as far as where
and how much surface based convection we will see later this
afternoon. Models continue to show strong uncapped instability
across the Cascades over into the Okanogan Highlands, as well as
over into the Northern Panhandle. This is where we expect the best
chances for afternoon thunderstorms to develop with the potential
for a few strong storms. KEAT and more so KMWH will be on the
southern fringe of this convection and may see a thunderstorm or two
this afternoon before this activity lifts northward this evening. By
tonight, we will shift to an elevated threat of thunderstorms around
03Z around the KLWS and KPUW taf sites then continuing to shift
northward and westward into KGEG, KSFF, KCOE and possibly KMWH by
the lat nighttime hours. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 92 68 84 65 81 60 / 20 90 60 50 50 20
Coeur d`Alene 91 66 84 62 78 58 / 30 90 70 50 60 30
Pullman 87 64 84 61 83 58 / 10 80 50 60 50 20
Lewiston 95 71 89 70 89 66 / 10 50 50 60 50 20
Colville 96 64 85 62 79 60 / 50 90 70 50 60 50
Sandpoint 91 63 81 58 76 55 / 50 80 70 60 70 50
Kellogg 93 63 82 60 76 56 / 40 90 70 70 70 40
Moses Lake 95 68 91 66 92 62 / 20 40 30 30 20 20
Wenatchee 93 69 87 70 89 65 / 30 30 40 30 10 20
Omak 96 67 89 66 88 63 / 50 90 60 30 40 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
304 PM CDT FRI JUL 13 2012
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW VARIOUS
SHORTWAVE TROUGHS EXTENDING FROM THE BOUNDARY WATERS OF MINNESOTA TO
THE SOUTHERN MISSOURI VALLEY EARLY THIS AFTERNOON. AHEAD OF THESE
TROUGHS...SHOWERS AND THUNDERSTORMS ARE MOST CLUSTERED OVER NORTHERN
MINNESOTA AND ALSO OVER EASTERN IOWA AND NORTHERN MISSOURI. LOCAL
MESOANALYSIS SHOWS CIN HAS ERODED OVER MUCH OF THE AREA WITH DAYTIME
HEATING...AND WIDELY SCATTERED SHOWERS AND STORMS ARE NOW POPPING
ACROSS MUCH OF THE FORECAST AREA. AS THE UPPER TROUGHS UPSTREAM
SLOWLY MOVE EAST OVER THE NEXT 24 HOURS...PRECIP CHANCES ARE THE
MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER MINNESOTA AND OTHER WEAK IMPULSES
ROTATING AROUND IT WILL SLOWLY MOVE SOUTHEAST ACROSS EASTERN
MINNESOTA AND WESTERN WISCONSIN. LARGE-SCALE ASCENT IS PRETTY WEAK
AND MID-LEVEL LAPSE RATES ARE ONLY AROUND 6 C/KM BUT THERE IS AMPLE
MOISTURE AVAILABLE WITH PWATS AROUND AND SLIGHTLY HIGHER THAN 1.50
INCHES. AS A RESULT...THINK SPOTTY SHOWER ACTIVITY THAT POPPED UP
THIS AFTERNOON WILL DIMINISH THIS EVENING. THEN AS THE SHORTWAVE
ENERGY MOVES CLOSER...WILL SEE SCATTERED SHOWERS AND ISOLATED
THUNDER PUSH BACK INTO THE WESTERN AND SOUTHERN PARTS OF THE
FORECAST AREA. NOT ENTIRELY CONFIDENT IN COVERAGE SINCE SHOWERS AND
STORMS WERE FAIRLY WIDESPREAD OVER WESTERN WISCONSIN WHEN I WALKED
IN THE DOOR THIS MORNING. WILL PLAY THE ODDS OF THE DIURNAL CYCLE
AND ERROR ON THE LOW SIDE. A MUGGY NIGHT WITH LOWS IN THE 60S.
SATURDAY...THE SHORTWAVE TROUGH WILL MAKE SLOW PROGRESS EASTBOUND
ACROSS THE STATE THROUGH THE DAY. THE 09Z SREF INDICATES THAT WILL
SEE SHOWERS AND STORMS DEVELOP FAIRLY QUICKLY BETWEEN 15-18Z
TOMORROW WHEN LOW LEVEL LAPSE RATES HAVE A CHANCE TO STEEPEN AND
INSTABILITY TO DEVELOP. CAPES ARE NOT THAT IMPRESSIVE (600-700
J/KG) AND THEY ARE RATHER SKINNY...BUT THERE IS PLENTY OF MOISTURE
AROUND (STILL 1.5 INCHES). WIND FIELDS ARE RATHER LIGHT SO STORMS
SHOULD BE SLOW MOVING...BUT COVERAGE UPSTREAM ONLY SUGGESTS AN
ISOLATED DAMAGING WIND AND HEAVY RAIN THREAT. THOUGH TEMPS WILL BE
A FEW DEGREES COOLER...HIGHER HUMIDITY WILL MAKE IT FEEL MORE
MUGGY. HIGHS RANGING THROUGH THE 80S.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
AN UPPER LEVEL SHORT WAVE AND A SURFACE BOUNDARY WILL PASS EAST
OF WISCONSIN DURING THE FIRST PERIOD OF THE FORECAST. ONLY HAVE
CHANCE POPS GOING IN THE EAST AND THEN NOTHING AFTER 06Z
SUNDAY...EXCEPT FOR SOME PATCHY FOG. A WARM FRONT PUSHING NORTH
INTO WISCONSIN WILL BRING MUCH ABOVE NORMAL TEMPERATURES TO THE
AREA...MAINLY ON MONDAY. THERE WILL BE A SLIGHT CHANCE OF SHOWERS
AND STORMS IN THE NORTH ON MONDAY IN THE VICINITY OF THE FRONT.
THERE IS A CHANCE OF THUNDERSTORMS MONDAY NIGHT AND TUESDAY ACROSS
CENTRAL WISCONSIN AS A COLD FRONT MOVES THROUGH THE STATE.
TEMPERATURES SHOULD REMAIN VERY WARM/HOT ON TUESDAY BUT THEY
SHOULD BE A BIT COOLER THAN MONDAY WITH CLOUDS AND POSSIBLE
CONVECTION. PRECIPITATION CHANCES MAINLY CONFINED TO CENTRAL AND
EAST CENTRAL WISCONSIN ON TUESDAY NIGHT...THEN IT LOOKS LIKE A
PERIOD OF DRY WEATHER WITH TEMPERATURES A LITTLE CLOSER TO NORMAL
FOR THIS TIME OF YEAR. A SHORT WAVE MOVING SOUTHEAST ACROSS THE
WESTERN GREAT LAKES REGION WILL BRING A CHANCE OF SHOWERS AND
STORMS TO NORTHERN WISCONSIN ON FRIDAY.
&&
.AVIATION...FOR 12Z TAF ISSUANCE. EXPECT CLD BASES TO RESULT IN
MAINLY VFR CIGS. BUT SOME LOWER CIGS COULD DEVELOP IN RGNS OF MORE
CONCENTRATED SHOWER ACTIVITY. IF ENOUGH RAIN FALLS TDA...SOME FG
COULD DEVELOP TNGT...THOUGH BETTER CHC OF THAT WL BE SAT NGT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
242 PM CDT FRI JUL 13 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
242 PM CDT FRI JUL 13 2012
A RARE FORECAST CHALLENGE INVOLVING RAIN FOR THIS PACKAGE BUT DONT
WORRY - HEAT STILL AN UPCOMING CONCERN AS WELL.
WHILE UPPER RIDGE REMAINS OVER ROCKIES...AND IS PREDICTED TO BUILD
BACK IN BY END OF WEEKEND...SHORT WAVE TROUGH APROACHING AREA FROM
THE NORTHWEST. THIS HAD GENERATED SOME RAIN OVERNIGHT WITH LINGERING
SHOWERS STILL TRANSVERSING THE AREA. MEANWHILE...KEEPING A CLOSE EYE
ON NEW CONVECTIVE DEVELOPMENT IN REGION WITH DECENT DESTABILIZATION
OVER MUCH OF CENTRAL AND SOUTHERN MINNESOTA THIS AFTERNOON WHERE
EARLIER CLEARING HAD TAKEN PLACE.
A BIT UNCLEAR ON HOW EXPANSIVE CONVECTION WILL BECOME HEADING INTO
THE EVENING BUT WIND SHEAR IN ALL LAYERS REMAINS WEAK. MESOSCALE
MODELS CONTINUE TO HINT AT MORE SCATTERED COVERAGE BUT HIGHLY
VARIABLE IN THEIR OUTPUT. AIRMASS IS A BIT MORE STABLE OVER
SOUTHEAST MINNESOTA COMPARED TO AREAS WHERE STRONGER STORMS ARE
FORMING SO NOT SURE HOW INTENSE THEY COULD BE AS THEY ADVECT CLOSER.
EITHER WAY NOT EXPECTING MUCH FOR ORGANIZATION WITH STORMS BUT
LOCALIZED CORES COULD PRODUCE SMALL BOUTS OF HAIL AND GUSTY WINDS.
RAINFALL WILL GENERALLY BE SPOTTY BUT HOPING MOST AREAS AT LEAST SEE
SOME. MUCAPE VALUES WILL DROP OFF QUICKLY THIS EVENING SO CONVECTION
TOO SHOULD WANE. TRENDED RAINFALL RISK IN THAT DIRECTION OVERNIGHT.
13.12Z MODEL SUITES IN GOOD AGREEMENT WITH SHORT WAVE TROUGH PASSAGE
A BIT EARLIER THAN PREVIOUS FORECASTS...INTO GREAT LAKES BY SATURDAY
AFTERNOON /15.00Z/. TRIED TO PUSH MAIN RAIN RISK ON SATURDAY MORE
EAST OF THE RIVER THAN WEST WITH DIMINISHING CHANCES THROUGH THE
DAY. AGAIN...RAINFALL LIKELY TO BE SPOTTY.
HIGH PRESSURE BUILDS BACK IN FOR QUIET WEATHER SATURDAY NIGHT INTO
SUNDAY. LOW LEVEL WARM AIR ADVECTION RETURNS IN EARNEST BY SUNDAY
AFTERNOON THOUGH...ESPECIALLY NORTHWEST OF THE AREA. WILL SEE
TEMPERATURES REBOUND AS UPPER RIDGE BEGINS TO BUILD BACK IN WITH
HIGHS LIKELY IN THE 90S AND SOME HEAT INDEX VALUES APPROACHING 100.
GUIDANCE 850 TEMPERATURES OF 22-25C SUGGESTED WITH ANOMOLIES OF +2
COULD SUPPORT AT LEAST NEAR RECORD HIGHS INTO MONDAY WITH SOME
RETURNING MOISTURE AS WELL. DEPENDING ON HOW HEAT INDEX FORECAST
DETAILS WORK OUT OVER THE WEEKEND...COULD SEE AT LEAST SHORT BOUT OF
HEAT ADVISORIES FOR EARLY NEXT WEEK.
.LONG TERM...TUESDAY THROUGH FRIDAY
242 PM CDT FRI JUL 13 2012
WHILE MEAN UPPER RIDGE ACROSS NATIONS MID SECTION CONTINUES TO BUILD
IN OUTER FORECAST PERIODS...SUBTLE FEATURES IN LOWER LEVELS WILL
BARE WATCHING.
APPEARS THERE COULD BE ENOUGH NORTHWEST FLOW ALOFT TO PUSH FRONTAL
BOUNDARY SOUTH ON TUESDAY. HIGHS TUESDAY WILL BE DEPENDENT ON THIS
WITH ANOTHER HOT DAY AHEAD OF FRONT...ACROSS MAINLY SOUTH. GENERALLY
GOING WITH IDEA THAT LARGE HUDSON BAY HIGH PRESSURE AREA WILL PUSH
THIS BOUNDARY FAR ENOUGH SOUTH FOR DRY FORECAST AROUND MID WEEK
UNTIL MORE WARMER AIR HEADS IN BY FRIDAY.
&&
.AVIATION...THROUGH 18Z SATURDAY
1209 PM CDT FRI JUL 13 2012
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO BUBBLE ACROSS THE
AREA THIS MORNING AHEAD OF THE SHORT WAVE TROUGH AND COLD FRONT
CROSSING THE UPPER MIDWEST. JUST ENOUGH LIFT FROM THE SHORT WAVE
TROUGH ALONG WITH BEING ON THE CONVERGENT EASTERN EDGE OF THE WEAK
MOISTURE TRANSPORT IS PROVIDING JUST ENOUGH TO KEEP THE ACTIVITY
GOING. THE 13.12Z RAP AND NAM SUGGEST LITTLE CHANGE IN THIS SET UP
THROUGH THE AFTERNOON AS THE SHORT WAVE TROUGH AND COLD FRONT MOVE
SLOWLY TO THE EAST SO EXPECTING THE SCATTERED ACTIVITY TO KEEP
GOING/REDEVELOPING. CONFIDENCE ON WHEN THESE WILL BE NEAR THE TAF
SITES REMAINS LOW SO WILL CONTINUE WITH VCTS AND UPDATED WHEN OR
IF ANY ACTIVITY GETS CLOSE TO THE AIRPORTS. SHOULD SEE THE
CONVECTION DIE OUT PRETTY QUICK THIS EVENING AS THE CAPE
DIMINISHES. THE FRONT SHOULD MOVE THROUGH BOTH SITES SATURDAY
MORNING WITH THE WINDS COMING AROUND TO THE WEST AND THEN
NORTHWEST DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
242 PM CDT FRI JUL 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1209 PM CDT FRI JUL 13 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
245 AM CDT FRI JUL 13 2012
FORECAST CONCERNS FOCUS ON THE POTENTIAL FOR SHOWERS/STORMS OVER THE
NEXT COUPLE DAYS.
CURRENT CONVECTION ACROSS THE REGION FORMING AROUND A WEAK SFC
BOUNDARY...SOME ELEVATED FRONTOGENESIS AND INSTABILITY...ALONG WITH
A LOW LEVEL MOISTURE BOUNDARY. MESO MODELS NOT DOING A GREAT JOB
WITH CAPTURING THE SHOWERS/STORMS. TRENDS THOUGH WOULD SUGGEST THAT
THE ACTIVITY WILL GRADUALLY DIMINISH LATER THIS MORNING AS IT MOVES
AWAY FROM THE MORE FAVORABLE ATMOSPHERE IN THE WEST. CONFIDENCE NOT
OVERLY HIGH...BUT WILL TREND THE FORECAST WITH THIS IN MIND.
CONDITIONS WILL BE MONITORED AND UPDATES TO THE FORECAST MADE...AS
NEEDED.
UPPER LEVEL SHORTWAVE TROUGH SET TO DRIVE SLOWLY EAST/SOUTHEAST FROM
THE NORTHERN PLAINS EARLY THIS MORNING...TO ACROSS WI BY 18Z SAT. A
SFC FRONT WILL ACCOMPANY THE SYSTEM...WITH SOME FRONTOGENETIC
RESPONSE PORTRAYED BY THE NAM/GFS...ALTHOUGH NOT WELL DEFINED.
MOISTURE TRANSPORT IS SOMEWHAT MEAGER AHEAD OF THE FRONT WITH
SHALLOW WARM CLOUD DEPTHS...STILL ABOUT 1.5 PWS. NAM12 DOES BUILD
ABOUT 2-3K J/KG OF MUCAPE AHEAD OF THE FRONT TODAY...AND ABOUT THE
SAME FOR SAT. ITS A FAIRLY SKINNY CAPE PROFILE PER BUFKIT
SOUNDINGS...USUALLY NOT SUPPORTIVE FOR EXPLOSIVE CONVECTION/STRONG
UPDRAFTS. WIND SHEAR IS LOCATED WELL BEHIND THE SYSTEM THOUGH...AND
DOES NOT LOOK TO BE MUCH OF FACTOR IN STORM
DEVELOPMENT/ORGANIZATION. ALL IN ALL...THERE WILL BE ENOUGH ELEMENTS
FOR MORE SHOWER/STORM DEVELOPMENT THIS AFTERNOON INTO SATURDAY.
CAN/T RULE OUT A SEVERE RISK DESPITE THE POOR SETUP...MOSTLY WEST OF
THE MISSISSIPPI RIVER. WHILE THIS SYSTEM SHOULD BRING SOME MUCH
NEEDED RAIN TO PORTIONS OF THE FORECAST AREA...ITS NOT THE SOAKER
THAT MOST NEED.
.LONG TERM...MONDAY THROUGH THURSDAY
245 AM CDT FRI JUL 13 2012
DECENT AGREEMENT BETWEEN THE GFS AND ECMWF WITH TRACKING AN UPPER
LEVEL SHORTWAVE TROUGH ACROSS SOUTHERN CANADA MON
NIGHT-TUE...SLIDING AN ASSOCIATED SFC FRONT ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THERE LOOKS TO BE A FEED OF LOW LEVEL
MOISTURE AHEAD OF THE BOUNDARY...WITH PWS OVER 1.5 INCHES AND SOME
INSTABILITY ADDED TO THE MIX. SHOULD BE ENOUGH FOR SOME
SHOWER/STORMS...BUT HOW WIDESPREAD THE ACTIVITY WOULD BE IS IN
QUESTION. LATEST POSITIONING AND TIMING WOULD FAVOR THE BETTER
CHANCES ACROSS THE SOUTH. A SFC HIGH THEN BUILDS BACK ACROSS THE
REGION...WITH SOME SUGGESTION OF ANOTHER AMPLIFYING RIDGE FOR NEXT
WEEKEND.
AS FOR TEMPS...850 MB ANOMALIES CONTINUE TO PEG AROUND +2 FOR MON
INTO TUE. MONDAY IS STILL SHAPING UP TO BE THE HOT DAY...WITH SOME
LOCATIONS FLIRTING WITH 100 STILL POSSIBLE. THE FRONT WILL HAVE SOME
SAY IN HIGHS FOR TUE...SO TIMING/POSITIONING WILL BE IMPORTANT.
TEMPS SHOULD COOL BACK TO MORE SEASONABLE NORMALS...BUT HEAT COULD
QUICKLY RETURN FOR NEXT WEEKEND IF THE AFOREMENTIONED RIDGE BUILDING
OCCURS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1209 PM CDT FRI JUL 13 2012
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO BUBBLE ACROSS THE
AREA THIS MORNING AHEAD OF THE SHORT WAVE TROUGH AND COLD FRONT
CROSSING THE UPPER MIDWEST. JUST ENOUGH LIFT FROM THE SHORT WAVE
TROUGH ALONG WITH BEING ON THE CONVERGENT EASTERN EDGE OF THE WEAK
MOISTURE TRANSPORT IS PROVIDING JUST ENOUGH TO KEEP THE ACTIVITY
GOING. THE 13.12Z RAP AND NAM SUGGEST LITTLE CHANGE IN THIS SET UP
THROUGH THE AFTERNOON AS THE SHORT WAVE TROUGH AND COLD FRONT MOVE
SLOWLY TO THE EAST SO EXPECTING THE SCATTERED ACTIVITY TO KEEP
GOING/REDEVELOPING. CONFIDENCE ON WHEN THESE WILL BE NEAR THE TAF
SITES REMAINS LOW SO WILL CONTINUE WITH VCTS AND UPDATED WHEN OR
IF ANY ACTIVITY GETS CLOSE TO THE AIRPORTS. SHOULD SEE THE
CONVECTION DIE OUT PRETTY QUICK THIS EVENING AS THE CAPE
DIMINISHES. THE FRONT SHOULD MOVE THROUGH BOTH SITES SATURDAY
MORNING WITH THE WINDS COMING AROUND TO THE WEST AND THEN
NORTHWEST DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 AM CDT FRI JUL 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04