Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/06/12
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 AM MDT SAT AUG 4 2012
.AVIATION...SMALL PATCH OF MVFR STRATUS NEAR KCOS AS OF 17Z WILL
DISSIPATE OVER THE NEXT HOUR AND WON`T INCLUDE IN THE NEW 18Z TAF.
ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS
THIS AFTERNOON...THOUGH STORMS SHOULD DISSIPATE AS THEY MOVE OFF
THE MTNS AND WILL LIKELY NOT IMPACT KCOS AND KPUB...AS MOISTURE
AND INSTABILITY ON THE PLAINS IS LIMITED. SLIGHTLY BETTER ODDS OF
A STORM AT KALS...THOUGH CHANCE IS STILL TOO LOW TO MENTION IN THE
TAF AT THIS POINT. TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY
AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH
THE NIGHT.
&&
.PREV DISCUSSION... /ISSUED 408 AM MDT SAT AUG 4 2012/
SHORT TERM...
(TODAY AND TONIGHT)
COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH
THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE
BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF
SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW
POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT
ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS
HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN
SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS
OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY
THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS
EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE.
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING
AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE
PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY
AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH
SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS.
MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH
TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG
THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH
MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE
SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM
BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY.
LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE
FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS
TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE
TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING
AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE
GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS
SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY.
TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS
OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS
UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD
BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE
DEGREES. -KT
LONG TERM...
(SUNDAY THROUGH SATURDAY)
THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE
FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER
ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO
BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST
ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE
BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND
HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP
THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH
PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH
AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT
WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL
HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS
FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON
SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE
PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO
LOWER 100S FOR THE PLAINS.
TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER
THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP
KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO
LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP
WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM
COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN.
WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL
REMAIN ANCHORED TO THE MOUNTAINS. 88
AVIATION...
MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND
NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO
30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS
DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE
AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY
PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO
SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE
AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND
SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER
CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO
LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE
LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER
SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE
NIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10/27
AREA FORECAST DISCUSSION
NWS PUEBLO CO
408 AM MDT SAT AUG 4 2012
.SHORT TERM...
(TODAY AND TONIGHT)
COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH
THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE
BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF
SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW
POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT
ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS
HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN
SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS
OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY
THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS
EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE.
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING
AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE
PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY
AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH
SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS.
MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH
TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG
THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH
MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE
SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM
BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY.
LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE
FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS
TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE
TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING
AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE
GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS
SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY.
TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS
OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS
UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD
BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE
DEGREES. -KT
.LONG TERM...
(SUNDAY THROUGH SATURDAY)
THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE
FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER
ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO
BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST
ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE
BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND
HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP
THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH
PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH
AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT
WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL
HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS
FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON
SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE
PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO
LOWER 100S FOR THE PLAINS.
TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER
THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP
KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO
LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP
WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM
COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN.
WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL
REMAIN ANCHORED TO THE MOUNTAINS. MOZLEY
&&
.AVIATION...
MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND
NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO
30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS
DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE
AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY
PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO
SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE
AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND
SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER
CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO
LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE
LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER
SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE
NIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/88
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 PM EDT SAT AUG 4 2012
.SHORT TERM...(TONIGHT-MONDAY NIGHT)
THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING SOUTH OF A
WEAK LOW PRESSURE AREA CENTERED ALONG IT NORTHWEST OF THE BAHAMAS
OR EAST SOUTHEAST OF FT PIERCE. LIGHT WNW FLOW ACROSS THE LOCAL
AREA TO ITS SOUTHWEST COMBINED WITH THE ATLANTIC SEA BREEZE HAS
ALREADY LED TO A FEW SHOWERS DEVELOPING ALONG IT OVER PALM BEACH
COUNTY NEAR THE COAST AND FARTHER SOUTH ALONG THE EAST COAST AREAS.
LOCAL WRF AND HRRR MODEL REFLECTIVITIES SEEM TO BE INITIALIZING
WELL WITH THIS PATTERN AND GENERALLY INDICATE THIS ACTIVITY
INCREASING IN COVERAGE THROUGH THE COURSE OF THE AFTERNOON TODAY
AS THE ATL SEA BREEZE CONTINUES TO MAKE ITS PUSH INLAND. THIS
COMBINED WITH THE ACTIVITY FROM YESTERDAY COULD GENERATE MORE
FLOODING CONCERNS DEPENDING ON WHERE THE HEAVIEST ACTIVITY
BECOMES CONCENTRATED AS THE DAY PROGRESSES. THE MORNING UPPER AIR
SOUNDING AT MIAMI ALONG WITH THE LATEST SATELLITE DERIVED 500 MB
TEMPERATURES INDICATE A MORE STABLE ENVIRONMENT COMPARED TO
YESTERDAY AND WITH THE BEST INSTABILITY OR COOLER MID /UPPER-LEVEL
AIR NOW TO THE WEST OF THE FL PENINSULA CLOSER TO THE BROAD UPPER
LOW CENTER OVER THE GULF OF MEXICO. THEREFORE...THE MAIN IMPACTS
FROM ANY STRONG STORMS THAT DO DEVELOP SHOULD REMAIN SUB-SEVERE
AND MAINLY ASSOCIATED WITH STRONG WIND GUSTS UP TO 50 MPH.
THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS
SURFACE TROUGH AND LOW JUST EAST OF THE LOCAL AREA AND GENERALLY
INDICATES THIS FEATURE CONTINUING WESTWARD OVER SOUTH FLORIDA
THROUGH TONIGHT...THEN WEST OF THE FL PENINSULA SUNDAY THROUGH
MONDAY. IN ITS WAKE...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE
AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM
THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE
CARIBBEAN SEA AND PASSES THE LOCAL AREA TO THE SOUTH SUNDAY THROUGH
MONDAY NIGHT. MODERATE EAST AND SOUTHEAST FLOW THROUGH THE LOW
LEVELS DUE TO A SLIGHTLY ENHANCED GRADIENT BETWEEN ERNESTO TO THE
SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH
PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE
RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD.
.LONG TERM (TUESDAY-FRIDAY)...
ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND
LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE
EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE
BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. WITH THE
EASTERLY FLOW IN PLACE...SHOWERS/TSTMS THAT DEVELOP DURING THIS TIME
SHOULD HAVE THE BEST CHANCE OF FORMING OVER THE INLAND AND WESTERN
LOCATIONS EACH AFTERNOON. MOISTURE BEGINS TO INCREASE ACROSS THE
AREA BY FRI.
&&
.MARINE...
A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED
NORTH OF THE BAHAMAS OR EAST SOUTHEAST OF CAPE CANAVERAL IS
FORECAST TO TRACK WEST AND NORTHWEST ACROSS THE FLORIDA PENINSULA
THROUGH TONIGHT. SCATTERED SHOWER AND STORMS ASSOCIATED WITH THIS
FEATURE WILL LEAD TO PERIODS WITH REDUCED VISIBILITIES ALONG WITH
LOCALLY HIGHER WINDS AND SEAS...ESPECIALLY ACROSS THE ATLANTIC
WATERS. SUNDAY THROUGH THE MID WEEK PERIOD...MODERATE EASTERLY
WINDS AND SEAS WILL BE ANTICIPATED AS TROPICAL STORM ERNESTO
PASSES SOUTH OF THE MARINE AREA ACROSS THE CARIBBEAN SEA. FOR THE
LATEST INFORMATION REGARDING ERNESTO...REFER TO THE LATEST
FORECASTS AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.FIRE WEATHER...
NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY
OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST.SOME DRIER AIR
WITH MODERATE EASTERLY FLOW APPEARS POSSIBLE THROUGH THE MID-WEEK
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 88 79 88 / 50 60 40 60
FORT LAUDERDALE 79 90 80 89 / 50 60 40 60
MIAMI 78 89 79 89 / 50 60 40 60
NAPLES 76 92 76 90 / 40 50 40 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 PM EDT SAT AUG 4 2012
.AVIATION...
SATELLITE AND RADAR SHOW AN AREA OF LOW PRESSURE OFF THE COAST OF
CENTRAL FLORIDA AND MOVING TO THE NORTHWEST. SHOWERS AND
THUNDERSTORMS REMAINED OVER THE LOCAL WATERS AND BAHAMAS. THE SEA
BREEZE BOUNDARIES WERE BEGINNING TO MOVE INLAND...WITH ISOLATED
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG IT. EXPECT ACTIVITY TO
BECOME MORE NUMEROUS OVER THE NEXT COUPLE OF HOURS...BUT MOST OF
THE ACTIVITY MAY BE JUST TO THE WEST OF THE EAST COAST TAF SITES.
SO WILL KEEP VCTS AT THE TAF SITES. KEPT VCSH TONIGHT ACROSS THE
REGION AS THE AREA OF LOW PRESSURE MOVES ACROSS FLORIDA TONIGHT
THROUGH SUNDAY. AT THIS TIME DID NOT CARRY THUNDERSTORMS
OVERNIGHT...BUT THIS WILL NEED TO BE MONITORED. EXPECT NUMEROUS
SHOWERS AND THUNDERSTORMS TO REDEVELOP ACROSS THE REGION ON
SUNDAY...PUSHING TOWARDS KAPF IN THE AFTERNOON. MOSTLY VFR
CONDITIONS WILL CONTINUE...BUT MVFR CIG/VIS ARE POSSIBLE IN AND
AROUND SHOWERS AND THUNDERSTORMS. EAST TO SOUTHEAST WINDS AROUND
10 KNOTS ARE EXPECTED AT THE EAST COAST TAF SITES THIS
AFTERNOON...WITH A WEST TO NORTHWEST WIND AT NAPLES. LIGHT
EASTERLY FLOW IS EXPECTED OVERNIGHT...WITH THE EAST COAST SEA
BREEZE PUSHING BY MID/LATE MORNING.
&&
.PREV DISCUSSION... /ISSUED 724 AM EDT SAT AUG 4 2012/
AVIATION...
A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS
SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS
FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND
WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD
TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY
LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST.
WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY
16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND
POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS
TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK
OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E
COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION.
SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE
MOVES PAST ANY ONE TERMINAL LATER TODAY.
PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/
.LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
.MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
724 AM EDT SAT AUG 4 2012
.AVIATION...
A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS
SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS
FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND
WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD
TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY
LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST.
WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY
16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND
POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS
TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK
OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E
COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION.
SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE
MOVES PAST ANY ONE TERMINAL LATER TODAY.
&&
.PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
..MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
358 AM EDT SAT AUG 4 2012
...LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
...MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
.DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
&&
.MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
&&
.FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
143 AM EDT SAT AUG 4 2012
.PREV DISCUSSION... /ISSUED 1013 PM EDT FRI AUG 3 2012/
UPDATE...
SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT
OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY
ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP
BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO
THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS
THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO
SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...
03
PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW.
ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS
THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT
STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN
THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO
2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE
INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS
CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL
PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH
00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK
NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE
ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON
AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR
OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD
COVER EXPECTED.
01
LONG TERM /SUNDAY THROUGH FRIDAY/...
DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD
AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND
SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF
MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND
TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE.
DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z
GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM
WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT
BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO
THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE
GFS...POPS MAY BE A LITTLE ON THE LOW SIDE.
11
&&
.AVIATION...
06Z UPDATE...
CONVECTION IN EASTERN ZONES WILL CONTINUE TO WEAKEN THROUGH THE
EARLY MORNING. EXPECT THAT MOST SITES WILL SEE IFR CIGS...POSSIBLY
LIFR...AROUND 12Z. CIGS WILL LIFT THROUGH MID-MORNING. EXPECT A
SIMILAR CONVECTIVE PATTERN TO FRIDAY...WITH PEAK ACTIVITY AROUND
00Z. WINDS GENERALLY SOUTHEAST THROUGH THE PERIOD...LIGHT
OVERNIGHT AND BETWEEN 5-10KT DURING THE DAY EXCEPT IN
THUNDERSTORMS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON MOST ELEMENTS...INCLUDING TIMING OF CONVECTION AND
DEVELOPMENT OF IFR CIGS.
LOW ON POTENTIAL LIFR CIG DEVELOPMENT.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 70 89 72 / 60 60 30 20
ATLANTA 89 72 91 74 / 60 60 30 20
BLAIRSVILLE 80 69 85 68 / 60 60 40 30
CARTERSVILLE 88 71 90 69 / 60 50 40 30
COLUMBUS 90 72 91 74 / 50 50 40 20
GAINESVILLE 85 71 87 72 / 60 60 30 30
MACON 93 72 91 73 / 40 40 40 20
ROME 88 71 90 71 / 50 50 40 30
PEACHTREE CITY 88 69 89 70 / 60 60 30 20
VIDALIA 93 74 92 75 / 30 30 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
341 PM CDT SAT AUG 4 2012
.DISCUSSION...
ISSUED 341 PM CDT SAT AUG 4 2012
COLD FRONT HAS BEEN MOVING A BIT QUICKER TOWARD THE CWA...AND WAS
LOCATED FROM NEAR THE QUAD CITIES SOUTHWEST TO NEAR KANSAS CITY.
WELL-DEFINED MESOSCALE VORTEX FROM CONVECTION IN IOWA HELPED TO
DEVELOPED AN MCS WHICH HAS BEEN ROLLING ACROSS THE NORTHERN THIRD
OF ILLINOIS THIS AFTERNOON. SOME OF THE SOUTHERN FRINGES CONTINUE
TO PUSH ACROSS AREAS FROM CANTON EAST TO EL PASO AT MID AFTERNOON.
INSTABILITY OVER THE AREA PEAKED EARLY THIS AFTERNOON WITH CAPES
AROUND 4000 J/KG...BUT SPC MESOANALYSIS HAS BEEN SHOWING SOME
DECREASE IN CAPES AND INCREASE IN CAPPING ALOFT. HOWEVER...STILL
QUITE A BIT OF INSTABILITY AVAILABLE FROM SOUTHERN MISSOURI
NORTHEAST INTO EAST CENTRAL ILLINOIS. LATEST NAM AND HRRR SHOW
DEVELOPMENT OCCURRING IN THESE AREAS OVER THE NEXT COUPLE HOURS.
WILL MAINTAIN LIKELY POPS OVER A LARGE PART OF THE CWA THIS
EVENING...THEN LIMIT THEM TO 40-50 PERCENT AFTER MIDNIGHT ACROSS
THE EAST CENTRAL AND SOUTHEAST CWA. ANY LINGERING RAIN ACROSS THE
FAR SOUTHEAST WILL LIKELY BE ENDING BEFORE SUNRISE.
LITTLE CHANGE MADE TO THE REMAINDER OF THE FORECAST. BRIEF
COOL DOWN WILL BE NOTED EARLY THIS WEEK AS HIGH PRESSURE DRIFTS
EAST ACROSS THE AREA. A SLOW WARMING TREND WILL BRING TEMPERATURES
BACK TO NEAR 90 MUCH OF THE REMAINDER OF THE WEEK...WITH HOTTER
WEATHER KNOCKING ON THE DOOR AS WE REMAIN ON THE FRINGE OF THE
UPPER RIDGING ACROSS THE WESTERN HALF OF THE NATION. MAIN FEATURE
OF CONCERN IN THE LONG RANGE IS ON THURSDAY AND FRIDAY...WHEN A
PIECE OF ENERGY DROPS SOUTHEAST OUT OF THE CANADIAN PRAIRIES. GFS
AND ECMWF NOT TOO FAR APART WITH THE TRACK OF THIS SHORTWAVE OVER
THE GREAT LAKES...BUT THE GFS IS MORE AGGRESSIVE WITH BRINGING
RAIN CHANCES ALL THE WAY SOUTH ACROSS ILLINOIS. WILL KEEP SOME
SLIGHT CHANCES IN THE GRIDS THURSDAY AND THURSDAY NIGHT...BUT WILL
LEAN MORE TOWARD THE ECMWF WITH ITS ODDS OF DRY WEATHER.
GEELHART
&&
.AVIATION...
ISSUED 1233 PM CDT SAT AUG 4 2012
TS ADVANCING ON THE ILLINOIS RIVER VALLEY THIS AFTERNOON RESULTING
IN TS ADDED TO PIA TAF. MORE LIKELY CLOSER TO 1830Z...BUT TEMPO
GROUP IN. ALSO HAVE ADDED GUSTS FOR THE AFTERNOON MOMENTUM
TRANSFER THAT MAY BE SLIGHTLY DELAYED BY THE SLOW IN DIURNAL
HEATING WITH THE EXPANSIVE ALTOSTRATUS AND AC OUT THERE NOW. SO
FAR...CONVECTIVE DEVELOPMENT REMAINS QUESTIONABLE ELSEWHERE...AND
AM KEEPING THE VCSH IN THE BEST TIME FRAME. WILL UPDATE AS BECOMES
NECESSARY FOR TS. TOWARDS MORNING...CHANCE FOR BR AND REDUCED
VSBYS INTO MVFR/IFR CAT REMAIN FOR TERMINALS WITH RAIN. SO
FAR...PIA AND BMI ARE MOST LIKELY AT THIS POINT. AND HAVE PUT IN A
BRIEF TEMPO FOR THE EARLY MORNING/DAWN HOURS.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1208 AM CDT SAT AUG 4 2012
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING
THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED
COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY
FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST
FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY
ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME
REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND
HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE
DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD
SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT
HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT
CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE
AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY
IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED
SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY
ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR
PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP
IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL
NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO
MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS
THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK
EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE
EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY
LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY
EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT
LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE
CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS
SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE
FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS
CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE
FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS
NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE
FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID
80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO
90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE
DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN
ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS
MONDAY NIGHT ACROSS MUCH OF THE CWA.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK
AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A
COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN
COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING.
READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT
NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY.
SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK
SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH
THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST
FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE
INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW
CONTINUING BEYOND THE FORECAST PERIOD.
&&
.AVIATION...04/06Z
CDFNT ENTERING NWRN IA WILL MOVE TO NEAR CENTRAL IA BY SHORTLY AFTER
SUNRISE...AND PASS SOUTHEAST OF THE TAF SITES BY EARLY SAT
AFTERNOON. LOW PRESSURE WAVE WILL TRAVEL NORTHEAST ALONG THE
FRONT. SCATTERED TSRA WILL ACCOMPANY THE FRONT AND ALSO WILL
DEVELOP NORTH OF THE FRONTAL BOUNDARY AS THE SURFACE WAVE LIFTS
NEWD. HAVE CARRIED A FEW HOURS OF TSRA AROUND THE FRONT AND SHOWERS
AFTER THE FRONT. THINKING IS THAT CONDITIONS WILL REMAIN VFR.
CLEARING WILL SPREAD SOUTH ACROSS THE STATE LATE SAT AFTERNOON AND
EVENING WITH LIGHT NWLY WINDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MS AUG 12
LONG TERM...COGIL
AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CDT SAT AUG 4 2012
...LONG TERM SECTION UPDATED AT 355 AM...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM CDT SAT AUG 4 2012
THIS MORNING:
SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE
TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH
THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES
FROM THE NW.
TODAY:
MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE
REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T
THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD
OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND
BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT
OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND
ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS
SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP
LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF
OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE
THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES
GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST
CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL
ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A
250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN
COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND
ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC
PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY
DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS
FOR THE REST OF TODAY.
TONIGHT:
THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY
OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED
ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850
HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION.
WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL
NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE
FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY
ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT
WITH VALUES IN THE 50S AND 60S DEG F.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 353 AM CDT SAT AUG 4 2012
TROPICAL THUNDERSTORMS CONTINUE TO BE VERY ACTIVE NORTH OF THE
EQUATOR FROM NEAR 120E TO 170E, AND A TROPICAL CYCLONE IS EVIDENT ON
SATELLITE IMAGERY SOUTH OF JAPAN. THE INDIAN OCEAN HAS BEEN FAIRLY
QUIET IN RECENT DAYS. IT DOES APPEAR THAT A COHERENT FEATURE IS
PROPAGATING RAPIDLY EASTWARD INTO THE WESTERN HEMISPHERE AND WILL
REACH THE WESTERN INDIAN OCEAN AGAIN BY MID AUGUST. ATMOSPHERIC
RELATIVE ANGULAR MOMENTUM CONTINUES TO BE SLIGHTLY ABOVE
CLIMATOLOGICAL VALUES, AND MOUNTAIN TORQUE HAS BECOME POSITIVE
RECENTLY. ALTHOUGH THE SIGNAL IS VERY WEAK, THE ATMOSPHERE MAY BE
HEADED TOWARD PHASE 5 OF THE WEICKMANN/BERRY GLOBAL WIND OSCILLATION
PHASE SPACE DIAGRAM. IF THIS OCCURS, ANTICYCLONIC FLOW WILL BE
FAVORED ON THE WESTERN UNITED STATES WITH A TENDENCY TOWARD
TROUGHING IN THE EAST BY MID AUGUST. MOST OF THE NUMERICAL MODELS
ARE SUGGESTING THIS TREND. THE ECMWF IS MORE AGGRESSIVE IN WEAKENING
THE UPPER LEVEL RIDGING IN THE CENTRAL PART OF THE COUNTRY THAN THE
GFS, AND MOST OF THE GEM ENSEMBLE MEMBERS MAINTAIN MORE RIDGING THAN
THE ECMWF DETERMINISTIC SOLUTION. GIVEN THE HOT, DRY CONDITIONS IN
THE CENTRAL AND SOUTHERN PLAINS AND IMPROBABILITY OF WIDESPREAD
BENEFICIAL RAINFALL, THE GFS SOLUTION SEEMS MORE REASONABLE.
THE UPPER LEVEL ANTICYCLONE CENTERED OVER SOUTHERN OKLAHOMA AND
NORTHERN TEXAS WILL WEAKEN AND RETROGRADE TO NEAR 110W BY MONDAY,
AND TROUGHING WILL AMPLIFY IN THE EASTERN UNITED STATES. THE PLUME
OF SUBTROPICAL MOISTURE EXTENDING FROM WESTERN MEXICO TO THE CENTRAL
PLAINS WILL DROP SOUTHWARD TO NEAR THE KANSAS/OKLAHOMA BORDER BY
SUNDAY MORNING, AND A FEW HIGH BASED SHOWERS MAY BE IN PROGRESS
UNDER THE TROPICAL PLUME SUNDAY MORNING. A WEAK UPPER LEVEL TROUGH
EVIDENT ON SATELLITE IMAGERY IN NORTHERN ARIZONA WILL APPROACH THE
CENTRAL PLAINS LATE SATURDAY NIGHT AND MAY ENHANCE SHOWER AND
THUNDERSTORMS UNDER THE TROPICAL PLUME ALONG AND NORTH OF THE
FRONTAL BOUNDARY IN THE SOUTHERN PLAINS. THE PLUME OF SUBTROPICAL
MOISTURE WILL CONTINUE TO DROP SOUTHWARD AS FLOW OVER THE CENTRAL
PLAINS BECOMES MORE NORTHWEST ON SUNDAY. THERE IS A MARGINAL CHANCE
THAT THUNDERSTORMS IN SOUTHEASTERN COLORADO COULD CLIP THE SOUTHWEST
CORNER OF KANSAS AS THEY PROPAGATE SOUTHEAST DURING THE EVENING
HOURS SUNDAY, BUT CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE POPS
YET. TEMPERATURES SUNDAY SHOULD BE NEAR SEASONAL AVERAGES.
VERY WARM AIR WILL SPREAD BACK INTO WESTERN KANSAS ON MONDAY AS
ANOTHER UPPER LEVEL TROUGH DIGS TOWARD THE GREAT LAKES AND LOW LEVEL
FLOW BECOMES MORE SOUTHWEST. TEMPERATURES MONDAY SHOULD RETURN TO
NEAR 100 DEGREES ACROSS WESTERN KANSAS. A WEAK UPPER LEVEL TROUGH
ROTATING AROUND THE WESTERN UNITED STATES ANTICYCLONE WILL APPROACH
THE CENTRAL PLAINS BY TUESDAY MORNING. WEAK SYNOPTIC SCALE LIFTING
MAY BE SUFFICIENT TO SUPPORT A FEW THUNDERSTORMS IN CENTRAL KANSAS
LATE MONDAY NIGHT INTO EARLY TUESDAY, BUT CONFIDENCE IS NOT HIGH.
ANOTHER UPPER LEVEL TROUGH ORIGINATING IN THE TROPICAL PACIFIC WILL
MOVE OVER THE UPPER LEVEL RIDGE AND APPROACH KANSAS ON WEDNESDAY,
AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE DAY WEDNESDAY
WITH THE BEST OPPORTUNITY IN CENTRAL AND EASTERN KANSAS.
UPPER LEVEL HIGH PRESSURE WILL BUILD BACK INTO KANSAS THURSDAY
THROUGH SATURDAY, AND MORE TEMPERATURES IN EXCESS OF 100 DEGREES CAN
BE EXPECTED. THE NEXT POSSIBILITY OF RAINFALL WILL BE AROUND 12
AUGUST WHEN ANOTHER UPPER LEVEL TROUGH DIGS INTO THE UPPER MIDWEST
AND SUPPORTS PROGRESSION OF A COLD FRONT INTO KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 62 93 64 / 20 10 0 0
GCK 83 62 92 65 / 20 10 0 0
EHA 84 65 88 68 / 20 10 10 10
LBL 87 65 90 66 / 20 10 10 10
HYS 85 58 93 63 / 20 10 0 0
P28 99 67 95 66 / 20 20 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...RUTHI
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 AM CDT SAT AUG 4 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM CDT SAT AUG 4 2012
THIS MORNING:
SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE
TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH
THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES
FROM THE NW.
TODAY:
MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE
REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T
THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD
OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND
BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT
OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND
ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS
SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP
LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF
OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE
THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES
GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST
CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL
ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A
250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN
COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND
ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC
PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY
DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS
FOR THE REST OF TODAY.
TONIGHT:
THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY
OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED
ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850
HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION.
WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL
NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE
FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY
ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT
WITH VALUES IN THE 50S AND 60S DEG F.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CDT FRI AUG 3 2012
ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM
SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL
MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY
SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST
NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS.
UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH
SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH
CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER
BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY.
GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS
EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION
HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST.
ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN
AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE
CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB
TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN
TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO
SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS
FORECAST STILL LOOKS ON TRACK.
ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID
MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH
I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST
KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL
YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD
COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING
PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING
TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE
SUGGESTS.
ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG
THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A
4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE
MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY
FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS
TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT
REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS.
BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR
CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL
ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK
SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY
NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE
DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE
ALONG THE NORTHWEST FLOW AND ACROSS KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 62 91 70 / 20 10 10 10
GCK 83 62 90 69 / 20 10 10 10
EHA 84 65 90 69 / 20 10 10 10
LBL 87 65 91 70 / 20 10 10 10
HYS 85 58 91 69 / 20 10 0 10
P28 99 67 94 71 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT AUG 4 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 352 PM CDT FRI AUG 3 2012
A NEARLY STATIONARY FRONT EXTENDED FROM SOUTHEAST KANSAS INTO THE
TEXAS PANHANDLE THIS AFTERNOON. LOW LEVEL MOISTURE WAS "POOLING"
NORTH OF THE FRONT OVER SOUTHWEST KANSAS WITH DEWPOINTS IN THE
UPPER 50S TO LOWER 60S, LEADING TO SURFACE BASED CAPE FROM
1000-1500 J/KG. A SHORTWAVE TROUGH WAS PROGRESSING ACROSS THE
NORTHERN ROCKIES TODAY AND WILL MOVE ACROSS THE NORTHERN PLAINS ON
SUNDAY. THIS FEATURE WILL HELP DRAG A COLD FRONT THROUGH SOUTHWEST
KANSAS SATURDAY MORNING. THE WARM FRONT WILL MOVE NORTHWARD
TONIGHT INTO SOUTHWEST KANSAS. A FEW THUNDERSTORMS MAY DEVELOP
NEAR AND NORTH OF THE WARM FRONT THIS AFTERNOON AND PROPAGATE
NORTHWARD AND EASTWARD THIS EVENING INTO KANSAS. ALSO, SURFACE
BASED CONVECTIVE INITIATION COULD OCCUR ACROSS SOUTHEAST COLORADO
THIS EVENING AND THEN PROGRESS INTO SOUTHWEST KANSAS PER NAM/HRRR.
GIVEN THE AFOREMENTIONED CAPE AND INCREASING HIGH LEVEL WINDS TO
40-45KTS, THESE STORMS ARE CAPABLE OF HAIL AS LARGE AS QUARTERS
AND WINDS ARE HIGH AS 60 MPH.
DECIDED TO CARRY THE HIGHEST POPS IN FAR SOUTHWEST KANSAS THIS
EVENING. ADDITIONAL ELEVATED THUNDERSTORMS COULD DEVELOP LATER
TONIGHT FURTHER NORTHEAST AND POSSIBLY INTO THE FIRST HALF OF THE
DAY SATURDAY. THE PREVIOUS TEMPERATURE FORECAST WAS IN GOOD SHAPE
FOR TONIGHT AND FRIDAY. SOME CLOUD COVER SHOULD KEEP TEMPERATURES
FROM FALLING TOO MUCH TONIGHT, ALTHOUGH THE WINDS COULD GO LIGHT
AROUND 12Z AHEAD OF THE FRONT WHICH WOULD PROMOTE RADIATIONAL COOLING.
WINDS SHOULD BE JUST SHY OF ADVISORY CRITERIA FOR FRIDAY BEHIND
THE COLD FRONT. TEMPERATURES WILL RISE INTO THE MID TO UPPER 80S
FOR MOST OF SOUTHWEST KANSAS, EXCEPT FOR 95 TO 101 IN SOUTH
CENTRAL KANSAS INCLUDING BARBER, PRATT AND COMANCHE COUNTIES WHERE
THE FRONT WILL NOT ARRIVE UNTIL 2-3 PM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CDT FRI AUG 3 2012
ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM
SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL
MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY
SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST
NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS.
UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH
SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH
CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER
BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY.
GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS
EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION
HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST.
ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN
AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE
CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB
TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN
TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO
SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS
FORECAST STILL LOOKS ON TRACK.
ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID
MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH
I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST
KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL
YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD
COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING
PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING
TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE
SUGGESTS.
ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG
THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A
4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE
MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY
FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS
TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT
REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS.
BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR
CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL
ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK
SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY
NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE
DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE
ALONG THE NORTHWEST FLOW AND ACROSS KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 87 61 91 / 80 20 10 10
GCK 71 86 59 90 / 60 20 10 10
EHA 70 86 61 90 / 80 20 20 10
LBL 71 88 62 91 / 80 20 20 10
HYS 71 86 58 91 / 20 20 0 0
P28 76 99 68 94 / 80 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
936 AM EDT SAT AUG 04 2012
.Mesoscale Discussion...
Issued at 936 AM EDT Sat Aug 4 2012
With the exception of a slight uptick in intensity over the southern
Blue Grass, storms in the rest of the LMK CWA are continuing to fall
apart this morning. Once the Blue Grass convection heads
east/weakens, we should see a relative lull in the precip before
scattered storms are able to fire up in the warm unstable air this
afternoon. In the grids we have decreased PoPs for the late morning
hours before bringing them back up in the afternoon.
Have been keeping an eye on the convection south of St Louis this
morning. HRRR has had the best handle on this activity, and that
model dives the thunderstorms to the SSE through western Kentucky,
west Tennessee, and into Alabama. So far this is being borne out on
regional radar loops. However, while that path would be to the west
of the LMK CWA, model data are hinting at new convection possibly
firing up on outflow heading east from the Mississippi Valley storms
into central Kentucky and, to a lesser extent, southern Indiana.
This further supports chance PoPs for the afternoon hours.
We have cut high temps in the southeast where morning clouds and
showers will linger the longest. Have left temperatures alone in
the rest of the area where more sunshine is occurring or expected.
May flirt with Heat Advisory criteria briefly this afternoon in the
far west, thanks more to dew points in the lower and middle 70s than
the air temperature, but with cirrus shield moving in from the west
and the brevity of any indices AOA 105, will stick with the SPS for
now.
Issued at 810 AM EDT Sat Aug 4 2012
Storms have been on the decrease over the past couple of hours as
the NLLJ weakens. However, some strong storms remain, especially
INVOF Elizabethtown and Hodgenville. Torrential rainfall is
occurring in these low centroid storms thanks to very high
precipitation efficiency in a soupy air mass. Have upped PoPs to
categorical where it is currently raining as well as downstream to
the east. Have also introduced "heavy rain" wording -- the
Elizabethtown KY Mesonet site reported 0.31 inches of rain in just 5
minutes. Have also greatly increased QPF numbers, to around an inch
and a half INVOF the Hardin/LaRue storms, and 0.50-0.75" downstream
into the Blue Grass.
&&
.Short Term (Today through Sunday)...
Issued at 325 AM EDT Sat Aug 4 2012
A lot to talk about in the short-term period. To start off with, a
weak low-level jet is setting up early this morning across central
Kentucky. This is aiding in moisture advection and lift. A few
showers and thunderstorms have developed along the KY-TN border and
continue to push northeast into central Kentucky. Additional
development is possible, but overall areal coverage should be
limited. These, mainly isolated, showers and thunderstorms will
dissipate as the low-level jet relaxes shortly after sunrise. We
should then be mainly dry until the afternoon hours, but an isolated
shower/storm cannot be ruled out given the moist air mass.
For the rest of today, there is a weak wave across portions of
Missouri propagating eastward early this morning. It seems this will
initiate convection across eastern Missouri a little later, which
will push east into our area later this afternoon. This should act
to increase our thunderstorm potential and coverage throughout the
day, particularly with diurnal heating. Will have to see if this
solution pans out, but either way, convection should fire this
afternoon just due to heating, with highs topping out in the lower
90s. Heat indices will top out in mid and upper 90s across the east,
with 100 to around 105 expected along and west of I-65. Still
expecting convection to decrease as the sun sets this evening.
Activity should ramp up again, mainly across southern Indiana and
north-central Kentucky as a low-level jet increases ahead of our
approaching cold front. Convection associated with this feature
appears to dissipate a bit shortly after sunrise as well, with the
loss of the low-level jet. However, convection will increase in
coverage throughout the day Sunday, mainly across central Kentucky
and points south/east, as the cold front pushes southeast through
the forecast area during peak heating.
Here is a caveat. The latest 4km NAM indicates convection along the
cold front should initiate late this afternoon/early evening across
portions of northern Illinois and central Missouri. This model
generates a good cold pool, which drops the convection quickly
southeast and into portions of southern Indiana shortly after
midnight. This line appears to be in a weakening stage, but arrives
faster than most models are predicting. This solution also continues
pushing the outflow boundary southeast where additional storm
development occurs across central and south-central Kentucky before
sunrise Sunday. If this pans out, most convection will be overnight,
with the Sunday afternoon storms having less coverage and being
confined to the frontal boundary forcing. Given the uncertainty
amongst models and this seeming to be an outlier, will not jump
completely on this solution, but this will be key to watch as the
day unfolds. This model has shown some positive results over the
last few days.
Otherwise, models continue to indicate total PWs of almost 2 inches
for today, which increases to just over 2 inches for Sunday. High
temperatures Sunday should reach the mid and upper 80s, with a few
locations perhaps touching 90 degrees. This will yield CAPE values
in the 2000-3000 J/kg range, especially across southern and eastern
portions of the forecast area during Sunday afternoon. Shear appears
to be maximized in the afternoon as well, with 0-6km bulk shear
values in the 20-30 knot range. Damaging wind, very heavy rainfall,
and some hail will be the main threats. Given the recent rainfall
across the area and the increase in total moisture through Sunday,
there could be localized flash flooding concerns.
.Long Term (Sunday Night through Friday)...
Issued at 304 AM EDT Sat Aug 4 2012
The first forecast challenge in the long term will be the timing of
Sunday`s cold front pushing through the region Sun night/early Mon.
Models vary in exactly when the front and unstable airmass will push
south of our area. Because this weather system is on in the
stronger side, will go with a more progressive soln closer to the 0Z
GFS and GFS ensembles. This would push the front through early Mon
morning and stall it out just to our south over TN during the day
Mon. So, with this timing in mind, strong to severe storms with
damaging winds, torrential rainfall, and cloud to ground lightning
may linger east of I-65 early Sun night. After midnight, expect
storms to decrease in strength and be more confined to the Lake
Cumberland region. For Mon, will keep 20-30% chance POPs in the
southeast CWA which may or may not pan out depending on the exact
location of the front and left over showers/t-storms. Temps will be
tricky to nail down Sun night and Mon depending on the exact front
position and clearing of clouds from NW to SE. Will go with a
decent gradient of highs/lows for the Sun night/Mon time
period. Looks like lows Sun night should bottom out in the mid 60s
north to lower 70s south. Highs on Monday should range from the
upper 80s to around 90 north to lower 80s southeast.
Sfc high pressure will settle in for Tues and most of Wed keeping
conditions dry with low humidity. Seasonal temps will prevail in
the upper 80s and lower 90s for highs both days. With mostly clear
skies, low temps will bottom out in the 60s.
By late Wed, the left over boundary from early in the week, will
transition to more of an inverted trough forecast to move back north
into our region by Thurs. Along with this weak boundary, an upper
low will dive south into the Great Lakes region with an upper level
shortwave around its periphery making its way into the Ohio Valley.
Therefore, will continue 30% POPs for Thurs.
For Fri and into the weekend, long range models diverge on how far
south the upper low will travel and to what degree of strength it
will have. At this point, at least some troughing and a cold front
look possible toward Thurs night/Fri time frame. Thus will keep low
POPs going with cooler temps (mid 80s) in store for the weekend.
&&
.Aviation (12Z TAF Issuance)...
Issued at 648 AM EDT Sat Aug 4 2012
Isolated to scattered showers/storms around BWG and LEX early this
morning will continue to push northeast as a weak low-level jet
remains overhead. Isolated cells are moving away from BWG, while
thunderstorms will be in the vicinity of LEX for a little longer
this morning. Could see cigs drop at LEX too if the storms move
directly overhead. Storm coverage should decrease as the low-level
jet relaxes.
Winds will become south-southwesterly and increase between 10 and 15
mph, with gusts 20-25 mph by this afternoon. Diurnal Cu will develop
once again, with storm chances increasing during peak heating. A
weak wave across Missouri this morning is initiating convection
across the mid Mississippi Valley. This activity should push east,
which could mean slightly greater areal storm coverage later this
afternoon. Will continue VCTS and a CB group in the TAFs for this.
Overnight, another low-level jet will strengthen overhead, with
borderline LLWS setting up across the area starting around 06Z. At
the same time, storms could develop during the pre-dawn hours along
the Ohio River. At this time, will not mention LLWS, but will
include VCTS at SDF for the early morning storm chance.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Mesoscale........13
Short Term.......MJP
Long Term........AMS
Aviation.........MJP
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE
COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...NO SIGNIFICANT CHANGES NEEDED FOR THIS UPDATE.
ONLY MADE MINOR TWEAKS TO TREND TOWARD CURRENT CONDITIONS.
PREV DISCUSSION...
CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND
HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE.
TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE
APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS
PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS
AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS
INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND
GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO
AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH
WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND
DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW
BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER
AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT
MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND
DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT
INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE
IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY
FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME
WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS
WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL.
HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL
PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX
TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S
W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE
MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE
COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT
INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT
HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO
THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS
WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS
WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF
AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY
LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY.
AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH
POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD
OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY
LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT
AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE
SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY
MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE
OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO
EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE
FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL
BE LAST TO CLEAR DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT.
DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY
NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY
THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES
ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE
NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING
W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY
MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED
TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE
VFR.
SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART.
HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN
EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING
COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER
COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5
FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME
OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS
HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE
OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED
THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT
AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3
FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW.
SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES
GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING
DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY
DROPPING THEM BACK 1-2 FEET.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...FITZSIMMONS
LONG TERM...OKULSKI
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT SAT AUG 4 2012
.SHORT TERM...(TONIGHT)
ISSUED AT 432 PM EDT SAT AUG 4 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS LOOKING
SHORTWAVE TROF ACROSS THE ERN DAKOTAS/MN. AT THE SFC...ASSOCIATED
COLD FRONT IS SLICING THRU WRN LAKE SUPERIOR/WRN UPPER MI AND NW
WI. DESPITE VIGOROUS LOOK OF SHORTWAVE...CONVECTION HAS BEEN KEPT IN
CHECK BY ABUNDANT CLOUD COVER THAT HAS PERSISTED THRU THE DAY ACROSS
GOOD PORTIONS OF UPPER MI AND NRN WI. LATEST SPC MESOANALYSIS SHOWS
MLCAPE OF MOSTLY UNDER 500J/KG ACROSS THE FCST AREA. HIGHEST
VALUES...A LITTLE OVER 500J/KG...ARE OVER THE E WHERE THERE HAS BEEN
MORE SUNSHINE WITH SFC DWPTS AROUND 70F. IF MORE INSTABILITY HAD
DEVELOPED...A FAIRLY SIGNIFICANT SVR WEATHER OUTBREAK WOULD PROBABLY
BE GETTING UNDERWAY ACROSS THE FCST AREA AS DEEP LAYER SHEAR IS
STEADILY INCREASING TOWARD THE 40-50KT RANGE DUE TO MIDLEVEL SPEED
MAX APPROACHING THE AREA.
MAIN SHOW TONIGHT WILL BE S OF THE AREA WITH CONVECTIVELY ENHANCED
SHORTWAVE TRACKING TOWARD SRN WI/NRN IL/LWR MI. THE ONGOING
ASSOCIATED CLUSTER OF STRONG/SVR STORMS WILL PASS S OF THE AREA.
THAT SAID...OVER THE NEXT FEW HRS...SHRA/TSRA SHOULD TEND TO EXPAND
NE ACROSS ROUGHLY THE E HALF OF THE FCST AREA AS HEIGHT FALLS AND
RIGHT ENTRANCE OF UPPER JET STREAK WORK TO INCREASE UPWARD MOTION.
THERE IS STILL THE POTENTIAL OF ISOLD SVR STORMS...BUT WITH CLOUD
COVER NOW INCREASING EVEN OVER THE ERN FCST AREA TO PREVENT
INSTABILITY FROM BUILDING HIGHER...IT APPEARS RISK OF SVR STORMS IS
DIMINISHING. WILL KEEP SLIGHT RISK OF SVR WORDING IN HAZARDOUS WX
OUTLOOK FOR THE NEXT FEW HRS OR SO.
AFTER ANY SHRA/TSRA WITH COLD FRONT DEPART...ATTENTION TURNS TO VORT
MAX AND SECONDARY COLD FRONT THAT WILL SWING INTO THE AREA LATE
TONIGHT. THERE HAS BEEN FAIRLY SOLID COVERAGE OF SHRA AND EVEN SCT
TSRA ACROSS SE MANITOBA INTO ADJACENT NRN ONTARIO WITH TROF AXIS
THOUGH PCPN HAS TAKEN ON MORE OF A DIURNAL SCT COVERAGE THIS AFTN.
AS TROF AXIS/VORT MAX DROP INTO THE AREA...THERE SHOULD BE DECENT
SHRA COVERAGE LATE TONIGHT INTO SUN MORNING...ESPECIALLY SINCE CAA
DROPS 850MB TEMPS TO AROUND 6C BY 12Z SUN. WITH WATER TEMPS AROUND
20C ON LAKE SUPERIOR...THE OVERWATER INSTABILITY WILL BE MORE THAN
SUFFICIENT FOR LAKE ENHANCEMENT UNDER CYCLONIC FLOW WITH ARRIVAL OF
VORT MAX. THUS...EXPECT SCT/NMRS SHRA TO DEVELOP LATE TONIGHT OVER
THE NW HALF OF UPPER MI. AS ALWAYS...UPSLOPE NW WINDS WILL LEAD TO
MOST NMRS COVERAGE OVER THE HIGHER TERRAIN DOWNWIND OF THE LAKE.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 432 PM EDT SAT AUG 4 2012
GOOD AGREEMENT FM THE GFS/ECMWF/GEM-NHEM WITH OVERALL UPPER AIR
PATTERN THROUGH THIS WEEK. PATTERN STARTS OFF WITH DEEP TROUGH OVER
THE UPPER GREAT LAKES AND BROAD WEST-TO-EAST RIDGE ACROSS THE
SOUTHERN TIER OF THE CONUS. BY MIDWEEK...RIDGE BECOMES MORE
AMPLIFIED OVER INTERMOUNTAIN WEST INTO WESTERN CANADA WHILE
TROUGHING REMAINS IN PLACE OVER EASTERN CANADA AND THE GREAT LAKES
AND NORTHEAST CONUS.
WEATHER WILL STAY ON THE ACTIVE SIDE AS MULTIPLE SYSTEMS IMPACT THE
UPPER GREAT LAKES. FIRST WILL BE RIGHT AT BEGINNING OF LONG TERM ON
SUNDAY. ANOTHER WEAKER COLD FRONT COMES THROUGH AREA ON TUESDAY.
MUCH STRONGER LOW PRESSURE SYSTEM FCST TO PUSH ACROSS GREAT LAKES
LATER THURSDAY INTO FRIDAY. IT IS THIS SYSTEM THAT SHOWS THE MOST
POTENTIAL TO PRODUCE NOTEABLE PRECIPITATION AMOUNTS IN THE LONG TERM.
SINCE THE LARGE TROUGH IS CLOSE BY AND RIDING REMAINS WELL TO THE
WEST...EXPECT TEMPERATURES TO GENERALLY BE WITHIN A FEW DEGREES OF
NORMAL. ONLY WARM EXCEPTION WILL BE ON MONDAY AHEAD OF ANOTHER COLD
FRONT. SOME COOL PERIODS ARE EXPECTED AS WELL. COOLEST OF THE BUNCH
LIKELY WILL BE ON SUNDAY...BUT SIMILAR COOLER TEMPERATURES MAY OCCUR
AGAIN ON FRIDAY ON IN WAKE OF LOW PRESSURE SYSTEM MOVING THROUGH THE
GREAT LAKES.
A VERY CHAGEABLE WEATHER DAY IS IN STORE FOR SUNDAY. COLD FRONT
THROUGH UPR MICHIGAN BY DAYBREAK WHILE SFC LOW PUSHES ACROSS JAMES
BAY. COOL AND MOIST CYCLONIC FLOW SFC THROUGH H7 AFFECTS MOST CWA
THROUGH LATE MORNING THEN HEIGHTS RISE QUICKLY WHILE EDGE OF SFC
HIGH BUILDS IN MID-LATE AFTN. MOIST CYCLONIC FLOW AND THERMAL TROUGH
WITH H85 TEMPS AS LOW AS +5C IN ADDITION TO A SHARP SECONDARY WAVE
DROPPING THROUGH MEAN TROUGH SHOULD COMBINE TO BRING A PERIOD OF
SHOWERS TO PORTIONS OF CWA THROUGH THE MORNING. WARM LK SUPERIOR
TEMPS NEAR +20C ALSO ALLOW LAKE EFFECT PROCESSES TO ENHANCE PCPN
AS DELTA T/S ARE AROUND 14-15C/LAKE INDUCED CAPES UP TO 250 J/KG.
INCREASED POPS OVER UPSLOPE AREAS FAVORED BY NW BLYR WINDS. HIGHEST
POPS IN THE MORNING...THEN RAPIDLY DROPPING OFF IN THE AFTN AS AREA
QUICKLY RESIDES IN SUBSIDENCE REGION OF THE STRONG SHORTWAVE. SKIES
PROBABLY CLEAR QUICKLY IN THE AFTN DUE TO SUBSIDENCE AND DRY AIR.
TEMPS KIND OF TRICKY...BUT FOLLOWED TREND CLOSER TO GEM-REGIONAL
SHOWING TEMPS STUCK IN THE MID 50S-LOW 60S INTO EARLY AFTN...THEN
RISING TOWARD 70 DEGREES LATER IN THE DAY WITH INCREASING SUNSHINE.
GUSTY WINDS OTHER FACTOR ON SUNDAY AS DEEP MIXING EXPECTED THROUGH
EARLY AFTN BEFORE H85 WARM ADVECTION INCREASES STABILITY. MIXED
LAYER WINDS THROUGH 16Z 35-40KT AND EXPECT GOOD PORTION OF THESE TO
MIX TO SFC. STRONGEST WINDS NEAR EXPOSED LK SUPERIOR SHORE OF CNTRL
AND EAST. EXPECT WINDS TO DIMINISH BY LATE DAY.
HIGH PRESSURE AXIS REMAINS JUST SOUTH OF AREA SUNDAY NIGHT BUT WINDS
BECOME LIGHT ENOUGH/PWAT LOW ENOUGH TO SEE SOME RADIATIONAL COOLING
TAKE PLACE. LOWEST MINS SEEM LIKELY IN THE INTERIOR CNTRL AND EAST
WHERE COLD SPOTS MAY DROP INTO LOWER 40S.
MUCH DIFFERENT DAY ON MONDAY COMPARED TO COOLER/WINDY DAY ON SUNDAY.
HIGH PRESSURE SLIDES EAST AND A WEAK COLD FRONT IS FCST TO DROP INTO
UPR LAKES MONDAY NIGHT. NOT A LOT OF CLOUD COVER AHEAD OF FRONT
THOUGH OTHER THAN ON THE KEWEENAW IN THE LATER AFTN. WITH H85 TEMPS
15C-16C EXPECT HIGHS TO REACH WELL INTO THE 80S AWAY FM LK MICHIGAN
SHORE. AS UPR JET SLIDES ACROSS ONTARIO MONDAY NIGHT AND MID-LEVEL
FGEN INCREASES OVR LK SUPERIOR...EXPECT BAND OF SHRA/TSRA TO DEVELOP
ALONG SFC FRONT. FRONT SLIDES THROUGH CWA ON MONDAY NIGHT...WITH
BETTER CHANCES OF SHRA/TSRA TIED INTO THE MID-LEVEL FORCING.
SOUNDINGS SHOW DRY AIR LINGERING BLO H85-H7 DUE TO LIMITED MOISTURE
ADVECTION FM THE GULF INTO THIS SYSTEM. SO...COVERAGE OF PRECIP WILL
BE SPOTTY WITH THE FRONT. HIGH PRESSURE BUILDS BACK IN FOR TUESDAY
WITH TEMPS IN THE 70S NORTH AND NEARING 80 DEGREES OVR THE SOUTH AND
NEAR LK MICHIGAN.
EXTENDED...MAIN CHANCES FOR SHRA/TSRA COME IN LATER WEDNESDAY NIGHT
INTO THURSDAY AS ANOTHER UPPER LOW AND SFC LOW MOVE ACROSS THE UPR
LAKES. CYCLONIC FLOW LINGERING IN THE WAKE OF THE SFC LOW COULD
KEEP SOME SHRA GOING OVR THE AREA INTO FRIDAY...KIND OF SIMILAR TO
WHAT IS EXPECTED ON SUNDAY. WITH EXPECTED CLOUDS/PCPN...TRIMMED
TEMPS THURSDAY AND FRIDAY CLOSER TO LK SUPERIOR WHERE ONSHORE
NORTHEAST FLOW SHOULD RESULT IN COOLER CONDITIONS. INCREASED WINDS
OVR LK SUPERIOR SOME COMPARED TO GUIDANCE CONSENSUS BUT MAY NEED TO
INCREASE FURTHER WITH LATER FCSTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT AUG 4 2012
COLD FRONT MOVING ACROSS THE AREA THIS AFTN/EVENING AND FOLLOWED BY
SECONDARY COLD FRONT LATE TONIGHT/SUN MORNING WILL BE THE FEATURES OF
INTEREST. CLOUD COVER PER SATELLITE IMAGERY SHOULD SUFFICIENTLY HOLD
INSTABILITY DOWN TO KEEP TSRA POTENTIAL MINIMAL WITH FIRST COLD FROPA
AT KIWD/KCMX. HAVE ONLY INCLUDED VCSH MENTION THRU THE MID TO LATE
AFTN HRS AT THOSE SITES. KSAW IS MORE LIKELY TO SEE TSRA LATER THIS
AFTN DUE TO BETTER POTENTIAL FOR INSTABILITY TO BUILD PRIOR TO FROPA.
IF TSRA OCCUR...IFR/LIFR CONDITIONS POSSIBLE ALONG WITH GUSTY WINDS.
A PERIOD OF VFR CONDITIONS EXPECTED AT ALL SITES AFTER FIRST FROPA.
SECONDARY COLD FROPA LATER TONIGHT/SUN MORNING WILL BRING GUSTY NW
WINDS TO ROUGHLY 25-30KT...STRONGEST AT KCMX DUE TO FAVORABLE WIND
DIRECTION AND INCREASING OVERWATER INSTABILITY UNDER INCOMING BRIEF
SHOT OF COOL AIR. WITH OVERWATER INSTABILITY BECOMING SUFFICIENT FOR
LAKE ENHANCEMENT...CYCLONIC FLOW AND PASSING SHORTWAVE SHOULD RESULT
IN A SEVERAL HR PERIOD OF IFR CONDITIONS IN SHRA/BR AT ALL SITES
LATER TONIGHT/SUN MORNING. IMPROVEMENT TO VFR EXPECTED AT KIWD/KCMX
LATE MORNING/EARLY AFTN AND AT KSAW JUST AFTER THIS FCST PERIOD AS
STRONG SUBSIDENCE/DRYING ARRIVE UNDER PROGRESSIVE FLOW PATTERN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SAT AUG 4 2012
COLD FRONT PASSES ACROSS LK SUPERIOR THIS EVENING. PERIOD OF STRONG
WINDS AND HIGH WAVES /LIKELY OVR 10 FEET/ EXPECTED LATE TONIGHT
THROUGH MUCH OF SUNDAY AFTERNOON. EXPECT 25-30 KT WINDS FM THE
NORTHWEST DURING ON SUNDAY WITH FREQUENT GALE GUSTS 35-40 KTS. A
GALE WATCH HAS BEEN POSTED FOR THE EAST HALF OF LK SUPERIOR MOST
OF SUNDAY. WINDS DIMINISH SUNDAY NIGHT...BUT THEN INCREASE FM THE
SOUTHWEST ON MONDAY AHEAD OF A COLD FRONT THAT SLIDES THROUGH ON
MONDAY NIGHT. IN WAKE OF THE FRONT...EXPECT WINDS 20 KTS OR LESS
TUESDAY INTO WEDNESDAY AS HIGH PRESSURE MOVES ACROSS THE REGION.
WINDS MAY END UP STRONGER THAN FCST FOR LATE THIS WEEK AS DETAILS
ARE SORTED OUT REGARDING ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH
THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LSZ251-
267.
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON FOR
LSZ249-250-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
154 PM CDT SAT AUG 4 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THE POWERFUL UPPER LEVEL SYSTEM WHICH SPARKED THE SQUALL LINE THAT
MARCHED ACROSS THE REGION OVERNIGHT WILL BE RESPONSIBLE FOR A
FEW MORE STORMS TODAY. IN THE WAKE OF THIS SYSTEM IS MUCH COOLER
AND DRIER AIR...WHICH WILL SETTLE IN ACROSS THE UPPER MIDWEST FOR
A MAJORITY OF THIS COMING WEEK.
TODAY...EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND
WINDS SHOWED A BEAUTIFUL UPPER LEVEL WAVE SLIDING DOWN ACROSS THE
DAKOTAS. THIS WAVE HAD ITS ORIGINS FROM ALBERTA CANADA...BUT THE
DIFFERENCE BETWEEN THIS SYSTEM AND A TYPICAL ALBERTA CLIPPER IS THAT
THIS STORM WAS ABLE TO TAP INTO THE MONSOONAL MOISTURE ASSOCIATED
WITH THE SUBTROPICAL JET OFF THE SOUTHWEST US. THE COMBINATION OF
THE STRONG DYNAMICAL FORCING WITH THE CANADIAN WAVE...AND THE
FAVORABLE THERMODYNAMICS OF THE SUBTROPICAL AIRMASS LED TO SEVERAL
AREAS OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WISCONSIN THROUGH
CENTRAL NEBRASKA. THE COMBINATION OF BOTH THE PHASING OF THE
SUBTROPICAL AND NORTHERN STREAM JETS...ALONG WITH THE CONTINUED
BANGING ON THE TROPOSPHERIC DRUM BY REPEATED ROUNDS OF CONVECTION
WILL CAUSE A +110KT JET STREAK TO FORM OVER NORTHERN MINNESOTA BY
LATER THIS AFTERNOON. THE AGEOSTROPHIC DIVERGENCE IN THE RIGHT
ENTRANCE REGION OF THIS JET...THE DOWNSTREAM POSITIVE VORTICITY
ADVECTION ASSOCIATED WITH THE UPPER LEVEL WAVE...AND THE LOW/MID
LEVEL FRONTOGENESIS WITH THE APPROACHING COLD FRONT WILL SUPPLY
PLENTY OF FORCING FOR CONTINUED PRECIP THROUGH THIS MORNING AND
EARLY AFTERNOON ACROSS THE SOUTHERN AND EASTERN CWA. FORECAST
SOUNDINGS SHOW DEEP LAYER SPEED SHEAR FAVORABLE FOR ORGANIZED
CONVECTION...BUT THE COLD AIR ADVECTION SHOULD LIMIT THE
INSTABILITY AND CONFINE SEVERE POTENTIAL TO CENTRAL AND EASTERN
WISCONSIN...DESPITE THE STRONG DYNAMICS. NONE THE LESS...COULD SEE
A FEW STRONGER STORMS EARLIER TODAY ACROSS FAR SOUTHERN AND EASTERN
MINNESOTA...AND WESTERN WISCONSIN. IN THE WAKE OF THIS
FRONT...NORTHWEST WINDS WILL INCREASE ACROSS THE ALEXANDRIA/ST
CLOUD AREA WITH AFTERNOON MIXING AND COLD AIR ADVECTION.
TONIGHT THROUGH FRIDAY...AN UPPER LEVEL RIDGE WILL SET UP ACROSS
THE 4-CORNERS REGION AND NORTHWEST FLOW WILL PREVAIL OVER THE
UPPER MIDWEST. FOR SUNDAY...COOLER AIR ON THE BACK SIDE OF THE
AFOREMENTIONED UPPER LEVEL WAVE WILL WRAP IN AND LIKELY BRING AN
END TO THE 80 DEGREE STREAK AT MINNEAPOLIS...WITH HIGHS ONLY
EXPECTED TO BE IN THE 70S REGION WIDE. A WEAK WAVE EMBEDDED IN
THIS FLOW REGIME WILL TRACK ACROSS THE REGION ON MONDAY...AND
COULD SEE SOME PRECIP DEVELOP ACROSS THE SOUTH LATE MONDAY ALONG
AN AREA OF H850 THETA_E ADVECTION. A SIMILAR FEATURE WILL TRACK
ACROSS THE REGION ON WEDNESDAY...WITH A MORE POTENT WAVE DROPPING
DOWN FROM CANADA OVER LAKE SUPERIOR ON THURSDAY. HAVE SOME 20-30
POPS IN THE GRIDS TO ACCOUNT FOR THESE TWO FEATURES. TEMPERATURES
WILL BE NEAR THE SEASONAL AVERAGE FOR LATE SUMMER.
&&
.AVIATION.../18Z TAF ISSUANCE/
PRIMARY FRONT HAS JUST CLEARED EAU...WITH A SECONDARY COLD FRONT
ASSOCIATED WITH THE UPPER LOW SLIDING SE ACROSS NODAK AND NW MN.
BAND OF MVFR CIGS IS WORKING ACROSS WRN WI BEHIND THE FRONT AND
WILL LINGER IN EAU THROUGH NO LATER THAN 20Z. COLD AIR ALOFT
ASSOCIATED WITH TROUGH LEADING TO THE DEVELOPMENT OF SCT SHOWERS
NW OF THE MPX AREA...THOUGH AS THE UPPER WAVE MOVES IN...EXPECT SCT
SHOWERS TO REACH DOWN INTO THE AXN/STC AREAS. FEEL HRRR IS A BIT
TOO AGGRESSIVE IN BRINGING SCT SHOWERS CLEAR DOWN TO THE IA BORDER.
TONIGHT...AS SECONDARY COLD FRONT SWINGS THROUGH...WINDS WILL TURN
NW AND WILL LIKELY COME WITH A BOUT OF MVFR CIGS...ESPECIALLY
ACROSS CENTRAL MN...THOUGH MSP/RNH/EAU MAY SEE SOME MVFR
CONDITIONS AS THE COLD AIR TROUGH MOVES THROUGH. AFTER
THAT...WEATHER LOOKS QUITE TRANQUIL FOR SUNDAY.
KMSP...ONLY A COUPLE OF MINOR THINGS TO WATCH THIS PERIOD.
FIRST...WITH SECONDARY FRONT TO DROP THROUGH THIS EVENING...MAY
SEE ENOUGH BACKING IN WINDS TO RESULT IN AN OCCASIONAL 250/260
DIRECTIONAL THROUGH 00Z BEFORE A MORE UNIFORM NW WINDS SETS UP
THIS EVENING. THERE WILL ALSO BE THE VERY SMALL THREAT OF AN
ISOLATED SHOWER AT THE AIRPORT THIS AFTERNOON...BUT BEST CHANCES
SHOULD BE CLOSER TO THE COLD AIR ALOFT NW OF THE FIELD.
FINALLY...PER THE RAP/NAM...EXPECT A BAND OF MVFR CIGS TO SWING
ACROSS NRN/CENTRAL MN THIS EVENING...WHICH MAY BRING THE THREAT
FOR AN MVFR CIG BETWEEN 5 AND 10Z BEFORE SKIES GO SKC.
/OUTLOOK/
.MONDAY...VFR. WINDS SW AT 10KT.
.TUESDAY...VFR. WINDS NW AT 5KT.
.WEDNESDAY...VFR. WINDS SOUTH 5 KNOTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1236 PM CDT SAT AUG 4 2012
.AVIATION...18Z TAFS
MVFR CIGS WILL LINGER ACROSS FAR E MINNESOTA AND NW WISCONSIN
THROUGH EARLY THIS AFTERNOON...INCLUDING AT KDLH/KHYR...DUE TO THE
LOW STRATUS ASSOCIATED WITH A COLD FRONT THAT MOVED THROUGH THE
REGION EARLIER THIS MORNING. THE VFR CONDITIONS THAT HAVE
DEVELOPED ACROSS THE REST OF THE NE MINNESOTA SHOULD SPREAD INTO
NW WISCONSIN THIS AFTERNOON. VFR CONDITIONS SHOULD PREDOMINATE FOR
THE MID TO LATE AFTERNOON...BUT ANOTHER COLD FRONT BEGINNING TO
MOVE INTO FAR NW MINNESOTA WILL BEGIN TO MOVE INTO NE MINNESOTA
MID TO LATE AFTERNOON. THIS SECOND COLD FRONT WILL PROBABLY RESULT
IN SCATTERED RAIN SHOWERS...AND MAYBE SOME WEAK THUNDERSHOWERS. AT
THIS POINT...INCLUDED VCSH AND TEMPO OF -RA FOR
KINL/KHIB/KBRD...BUT MAY NEED TO INCLUDE VCTS OR TEMPO OF -TSRA
ONCE ANY STORMS MOVE INTO OR DEVELOP OVER NE MINNESOTA.
ALSO...THE SHOWERS AND STORMS MAY RESULT IN BRIEF PERIODS OF MVFR
CIGS AND VSBYS. WESTERLY WINDS OF 10 TO 15 KNOTS WITH GUSTS UP TO
25 KNOTS ARE GENERALLY EXPECTED THROUGH EARLY THIS EVENING AT ALL
TERMINALS...WITH WINDS RELAXING AND BECOMING NORTHWESTERLY
TONIGHT. MVFR CIGS WILL PROBABLY REAPPEAR THIS THIS EVENING IN THE
WAKE OF THE COLD FRONT...BUT CLEAR SKIES SHOULD DEVELOP LATE
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 933 AM CDT SAT AUG 4 2012/
UPDATE...
SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER
ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS
MORNING.
SHORT TERM...
THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING
THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW
AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS
SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES
PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND
THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS
ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW...
BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A
LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER.
PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/
AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 53 76 55 83 / 20 10 0 10
INL 45 77 54 80 / 40 10 0 20
BRD 53 77 53 85 / 10 10 0 10
HYR 54 76 50 84 / 10 10 0 10
ASX 55 77 54 82 / 20 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...EOM
LONG TERM....GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
933 AM CDT SAT AUG 4 2012
.UPDATE...
SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER
ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS
MORNING.
&&
.SHORT TERM...
THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING
THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW
AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS
SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES
PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND
THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS
ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW...
BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A
LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER.
.PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/
AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 40 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 50 10 10 0
ASX 81 58 76 56 / 50 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...EOM
LONG TERM....GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 AM CDT SAT AUG 4 2012
.AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 20 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 40 10 10 0
ASX 81 58 76 56 / 40 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
323 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
&&
.AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 20 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 40 10 10 0
ASX 81 58 76 56 / 40 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM....GSF
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
554 PM CDT Sat Aug 4 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Well, looks like we have to wait for rain again. At least in many
areas this seems to be the appropriate theme for today, as yet
another shortwave/MCV race ahead of the surface front this morning
effectively shoving stabilizing much of northern Missouri and
allowing a weak surface trough to sneak southeast into Missouri and
Kansas. Currently the primary surface trough stretches from Ottumwa,
IA southwest through Kansas City and further south towards Wichita,
KS. A continued stream of mid-level strato-cu has suppressed the
warm surface temperatures in the extreme southern CWA with 88D radar
composites indicating northward extent of surface warm front is just
south of the Pleasant Hill office.
For tonight, highest convective potential remains along our southern
and southeastern tier of counties and again in areas near Kirksville
as mid-level shortwave currently moving through central Kansas
reaches the area after 4pm. HRRR and RAP suggest widely scattered
convection forming along the differential heating axis in the
southern CWA after 4pm with this convection slowly sinking southeast
this evening. Instability and shear plots indicate multi-cell
clusters would be the preferred storm type with downburst winds the
main threat. Elsewhere in areas further north, scattered high based
showers or sprinkles may the result of the weak shortwave and 850
trough passing through the area this evening. Dew points will remain
elevated through the evening as true front is just arriving into the
northwest corner of the CWA.
Will linger chc pops across the southern CWA through the overnight
hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied
with the right entrance region of the upr jet may be enough forcing
for west to east ling of elevated convection through early Sunday
morning in west central into central MO.
Sunday-Monday: Surface high pressure will drift southeast into the
region by Sunday morning. North to northeast winds will prevail
through the daytime hours with temperatures struggling to reach the
middle 80s in northern MO and barely hitting 90 towards east central
Kansas and central MO. This surface ridge will quickly slide into
the Ohio river valley by Monday allowing winds to take a more
southerly track. The resultant bump in low-level temperatures will
push daytime highs in the lower to middle 90s.
Tuesday-Friday: The overall longwave pattern will feature a building
ridge over the western CONUS and broad northwesterly flow over the
central and eastern US. GFS/EC/GEM indicate a weak disturbance in
the NW flow pattern moving through as we reach Tuesday night into
Wednesday. Always hard to time these shortwaves and their impact
especially considering the lack of boundary layer moisture. However
one could justify at least a slight chance for precip. Temperatures
will run near or slightly above normal through the end of the week.
31
&&
.AVIATION...
VFR conditions expected for all terminals through the forecast
period. Widely scattered showers continue to move across the area
this evening but should push east of the TAF sites in a few hours.
Otherwise, light north winds are expected to persist through
tomorrow.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053-
054.
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
323 PM CDT Sat Aug 4 2012
.DISCUSSION...
Well, looks like we have to wait for rain again. At least in many
areas this seems to be the appropriate theme for today, as yet
another shortwave/MCV race ahead of the surface front this morning
effectively shoving stabilizing much of northern Missouri and
allowing a weak surface trough to sneak southeast into Missouri and
Kansas. Currently the primary surface trough stretches from Ottumwa,
IA southwest through Kansas City and further south towards Wichita,
KS. A continued stream of mid-level strato-cu has suppressed the
warm surface temperatures in the extreme southern CWA with 88D radar
composites indicating northward extent of surface warm front is just
south of the Pleasant Hill office.
For tonight, highest convective potential remains along our southern
and southeastern tier of counties and again in areas near Kirksville
as mid-level shortwave currently moving through central Kansas
reaches the area after 4pm. HRRR and RAP suggest widely scattered
convection forming along the differential heating axis in the
southern CWA after 4pm with this convection slowly sinking southeast
this evening. Instability and shear plots indicate multi-cell
clusters would be the preferred storm type with downburst winds the
main threat. Elsewhere in areas further north, scattered high based
showers or sprinkles may the result of the weak shortwave and 850
trough passing through the area this evening. Dew points will remain
elevated through the evening as true front is just arriving into the
northwest corner of the CWA.
Will linger chc pops across the southern CWA through the overnight
hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied
with the right entrance region of the upr jet may be enough forcing
for west to east ling of elevated convection through early Sunday
morning in west central into central MO.
Sunday-Monday: Surface high pressure will drift southeast into the
region by Sunday morning. North to northeast winds will prevail
through the daytime hours with temperatures struggling to reach the
middle 80s in northern MO and barely hitting 90 towards east central
Kansas and central MO. This surface ridge will quickly slide into
the Ohio river valley by Monday allowing winds to take a more
southerly track. The resultant bump in low-level temperatures will
push daytime highs in the lower to middle 90s.
Tuesday-Friday: The overall longwave pattern will feature a building
ridge over the western CONUS and broad northwesterly flow over the
central and eastern US. GFS/EC/GEM indicate a weak disturbance in
the NW flow pattern moving through as we reach Tuesday night into
Wednesday. Always hard to time these shortwaves and their impact
especially considering the lack of boundary layer moisture. However
one could justify at least a slight chance for precip. Temperatures
will run near or slightly above normal through the end of the week.
31
&&
.AVIATION...
For the 18Z TAFs...Quick progression of a cold front across Missouri
has resulted in winds at the terminals turning to the northeast in
the wake of some scattered convection this morning. Further
thunderstorm development might occur across northern and central
Missouri this afternoon, but at this time thoughts are this activity
will be east of all the terminals. As a result, only issue to watch
for looks to be the slightly gusty north winds this afternoon in the
post-frontal environment. Winds should stay from the north
overnight, with VFR skies prevailing.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053-
054.
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
406 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE
NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING
ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED
BY JUST HOW COOL WILL IT GET TONIGHT.
19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER
MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE
MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED
WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA
TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST
OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE
STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE
SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE
AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF
ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING
TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE
CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG
MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE
500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE
RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP
WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO
BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW
80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE
SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN
THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN
THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF
THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL
HANGING ON IN THE SOUTHEAST.
STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A
LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS
LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE
BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST
COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE
LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS
OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST
OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED
SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS
LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL
CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB.
GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE
EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS
THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED
SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST
OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS
THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION
OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE
RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS
WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO
THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY
LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN
SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY
OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING
SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL
NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z
MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS
FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN
COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL
AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE
VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S.
FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE
OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING.
FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED
OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS
FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL
REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE
AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS
NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT
TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND
VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE
AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE
AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE
AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL
GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY
REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT
REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY
81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST
MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY
DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL
WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO
EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL
THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND
ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS
YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS
ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM
PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND
LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD
DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A
FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF
FIRE WEATHER CRITERIA.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD
OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY
EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER
LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE
SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST.
DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER
TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE
DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST
DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING
S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY
SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ
DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS
LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE
CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL
FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY
DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD
COVER.
INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A
MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY
DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE
AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY
LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA.
DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE
N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER
SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY
WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER
TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR
MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS
SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE
LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE
EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE
TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO
TREND UP WINDS/TREND DOWN DPS.
KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY
ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE
SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB
AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF
THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT.
WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT
BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND
FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE
LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS
THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY
NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS
EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE
NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS
IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE
POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR
TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS
THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT
OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO
WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT
EXPECTING SEVERE WEATHER AT THIS POINT.
INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER
LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN
THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN
PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER
CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM
PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE
REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL
ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS
SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF
THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE
RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE
POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER
TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM
ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT.
&&
.PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST
THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA
THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL
3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM
OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING
SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER
MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN
THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS
WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW
HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS
COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD
AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH
TIME.
&&
.CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST
DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON
FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY
HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP
SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST
78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE
THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES
WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT
TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD
ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED
78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR
BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3
DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES
ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994.
ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE
THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND
ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE
NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING
ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED
BY JUST HOW COOL WILL IT GET TONIGHT.
19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER
MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE
MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED
WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA
TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST
OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE
STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE
SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE
AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF
ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING
TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE
CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG
MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE
500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE
RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP
WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO
BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW
80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE
SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN
THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN
THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF
THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL
HANGING ON IN THE SOUTHEAST.
STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A
LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS
LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE
BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST
COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE
LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS
OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST
OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED
SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS
LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL
CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB.
GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE
EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS
THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED
SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST
OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS
THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION
OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE
RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS
WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO
THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY
LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN
SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY
OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING
SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL
NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z
MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS
FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN
COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL
AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE
VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S.
FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE
OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING.
FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED
OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS
FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL
REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE
AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS
NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT
TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND
VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE
AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE
AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE
AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL
GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY
REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT
REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY
81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST
MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY
DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL
WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO
EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL
THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND
ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS
YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS
ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM
PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND
LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD
DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A
FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF
FIRE WEATHER CRITERIA.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD
OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY
EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER
LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE
SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST.
DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER
TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE
DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST
DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING
S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY
SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ
DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS
LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE
CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL
FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY
DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD
COVER.
INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A
MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY
DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE
AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY
LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA.
DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE
N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER
SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY
WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER
TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR
MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS
SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE
LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE
EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE
TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO
TREND UP WINDS/TREND DOWN DPS.
KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY
ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE
SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB
AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF
THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT.
WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT
BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND
FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE
LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS
THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY
NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS
EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE
NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS
IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE
POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR
TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS
THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT
OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO
WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT
EXPECTING SEVERE WEATHER AT THIS POINT.
INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER
LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN
THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN
PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER
CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM
PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE
REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL
ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS
SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF
THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE
RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE
POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER
TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM
ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT.
&&
.PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/
UPDATE...THE PRIMARY CHALLENGE FOR THE REST OF TODAY INVOLVES
WHETHER THERE IS MUCH RISK AT ALL FOR MEASURABLE RAIN...AND JUST
HOW COOL HIGH TEMPS MAY END UP BEING UNDER THE AREAS THAT HOLD
ONTO CLOUDS THE LONGEST. 1630Z RADAR IMAGERY AND VISIBLE SATELLITE
REVEAL A SCATTERED STREAM OF LIGHT SHOWERS/SPRINKLES LIKELY BASED
AROUND 700MB STREAMING INTO SOUTHWEST PORTIONS OF THE CWA FROM THE
WEST. THIS HIGH BASED ACTIVITY SEEMS FAIRLY WELL TIED TO A MODEST
CORRIDOR OF CONVERGENCE/FRONTOGENESIS EVIDENT AT 700MB AND ALSO ON
THE 315K ISENTROPIC SURFACE. THIS FORCING IS ALIGNED ALONG THE
SOUTHERN PERIPHERY OF THE MAIN MID LEVEL SHORTWAVE AXIS TRAILING
SOUTHWEST FROM THE PARENT STOUT VORT MAX NEAR THE MN/QUEBEC
BORDER. EXPECTATION BASED ON SHORT TERM TRENDS FROM THE LATEST
HRRR/RAP IS FOR MAINLY LIGHT HIGH BASED SHOWERS TO CONTINUE
SPREADING FROM WEST TO EAST TROUGH AT LEAST 21Z OR SO ACROSS AREAS
PRIMARILY SOUTH OF INTERSTATE 80...LIKELY AMOUNTING TO LITTLE MORE
THAN A BRIEF SPRINKLE MOST SPOTS. HOWEVER...LEFT AN ISOLATED
THUNDER AND EVEN A SMALL HAIL MENTION INTACT...JUST IN CASE A FEW
STRONGER STORMS ARE ABLE TO FLARE UP AND TAP INTO ELEVATED MUCAPE
POSSIBLY AS HIGH AS THE 500-1000 J/KG RANGE...BUT LIKELY LESS THAN
THIS. THE MOST FAVORABLE AREA FOR ONE OF THESE STRONGER
STORMS...SHOULD THEY EVEN DEVELOP...WOULD BE ACROSS A HANDFUL OF
FAR SOUTHEASTERN COUNTIES. OTHERWISE...CURRENT EXPECTATION IS
THAT ANY PRECIPITATION RISK FOR THE NEXT FEW DAYS WILL BE OVER
WITH BY...OR SHORTLY AFTER 21Z THIS AFTERNOON. TEMP WISE
TODAY...HAVE ESSENTIALLY LEFT PREVIOUS HIGH TEMPERATURES
UNCHANGED. ANTICIPATE THAT AT LEAST CENTRAL/NORTHWEST PORTIONS OF
THE CWA SHOULD SEE A RAPID CLEARING TREND AS THE AFTERNOON WEARS
ON...LIKELY ALLOWING TEMPS TO EVENTUALLY JUMP UP TO FORECAST
VALUES AROUND 83. HOWEVER...SOUTHEAST PORTIONS OF THE CWA THAT
WILL LIKELY REMAIN UNDER THE CLOUDS THE LONGEST COULD STRUGGLE TO
REACH THE FORECAST VALUES OF 82-84...AND AGREE WITH OVERNIGHT
FORECASTER THAT SOME SPOTS MAY NOT ESCAPE THE UPPER 70S. WILL HAVE
A BETTER HANDLE ON THIS BY AFTERNOON FORECAST ISSUANCE TIME.
OTHERWISE...INTRUSION OF DRIER AIR BEHIND THE COLD FRONT HAS BEEN
FAIRLY IMPRESSIVE WITH ORD DOWN TO 49 DEWPOINT NOW. AS A
RESULT...LOWERED AFTERNOON DEWPOINTS 6-8 DEGREES ACROSS MUCH OF
THE CWA...WITH COMFORTABLE 40S/LOW 50S DEWS LIKELY INTO MOST
COUNTIES BY MID-LATE AFTERNOON. NORTH BREEZES WILL CONTINUE
GUSTING AT LEAST 20-25 MPH THROUGH MID AFTERNOON...BEFORE STEADILY
DECLINING BEFORE SUNSET.
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST
THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA
THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL
3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM
OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING
SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER
MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN
THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS
WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW
HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS
COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD
AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH
TIME.
&&
.CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST
DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON
FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY
HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP
SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST
78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE
THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES
WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT
TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD
ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED
78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR
BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3
DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES
ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994.
ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE
THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND
ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
419 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...ECMWF AND GFS MODELS SHOW A WEAK
RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT AND
WILL REMAIN OVER THE REGION THROUGH EARLY WEDNESDAY...WITH FAIR
AND DRY WEATHER EXPECTED. ON WEDNESDAY...ECMWF AND GFS MODELS SHOW
SOME WEAK SHORTWAVES WILL MOVE THROUGH THE REGION ON WEDNESDAY AND
EARLY WEDNESDAY NIGHT. GFS AND ECMWF MODELS BOTH SHOW SOME
CONVECTION DEVELOPING ALONG THE INTERNATIONAL BORDER BY WEDNESDAY
AFTERNOON AND EARLY WEDNESDAY NIGHT...SO HAVE GONE WITH SLIGHT
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS NEAR THE CANADIAN
BORDER. ON THURSDAY... MODEL GUIDANCE AGAIN SHOWING SOME MORE WEAK
SHORTWAVES MOVING THROUGH THE REGION...SO HAVE GONE WITH SLIGHT
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. EXPECTING
DRY CONDITIONS THURSDAY NIGHT. ON FRIDAY...ECMWF AND GFS MODELS IN
GOOD AGREEMENT IN SHOWING A LOW AT THE SURFACE AND ALOFT MOVING
EAST FROM THE WESTERN GREAT LAKES... WITH BOTH MODELS SHOWING
SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE REGION ON FRIDAY.
ECMWF AND GFS MODELS IN GOOD AGREEMENT THROUGH THE FORECAST
PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR
SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN
AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS
...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY
AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL
LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS
DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE
BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE
WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE
ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF
THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT
KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL
BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME
SURFACE HEATING.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z
SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...WGH
AVIATION...WGH/RJS
MARINE...KGM/MUCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
235 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF
SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND
UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN
BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION
BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE
COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S.
ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF
HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH
EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF
WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY
AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS
AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND
ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE
PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE
WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT.
TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH
THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD
COVER.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR
SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN
AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS
...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY
AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW
LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH
CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS
THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS
IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN
THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND
KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO
DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE
HEATING.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z
SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...WGH/RJS
MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
138 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD.
PREV BLO...
730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA
TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM
ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS.
RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL
POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS
AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND
DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV
BLO...
4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
IN GENERAL VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD.
THERE MAY BE MVFR VSBY RESTRICTIONS DUE TO HZ/BR AT KELM/KAVP
EARLY THIS MORNING BETWEEN 09Z-12Z. JUST SCATTERED CI THROUGH MID
MORNING THEN SCT CU AROUND 5K FT TODAY. ISOLATED CONVECTION IS
POSSIBLE THIS AFTERNOON IN THE HIGHER TERRAIN BUT NOT INCLUDED IN
TAFS DUE TO VERY LIMITED AREAL COVERAGE. OVERNIGHT AS NEXT SYSTEM
APPROACHES REGION SCT MID CLOUDS ARE LIKELY.
WINDS WILL BE LIGHT AND VARIABLE INTO MID MORNING THEN SOUTHERLY
AROUND 10 KNOTS BECOMING SOUTHEAST TONIGHT AROUND 5 KNOTS.
OUTLOOK...
SUN MORNING...VFR WITH POSSIBLE MVFR VSBYS RESTRICTIONS EARLY SUN
AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...HEDEN
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF
SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND
UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN
BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION
BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE
COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S.
ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF
HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH
EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF
WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY
AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS
AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND
ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE
PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE
WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT.
TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH
THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD
COVER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS
THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR
CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS
AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON
AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY
BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE
SOUTHERLY DIRECTION LATE SATURDAY MORNING INTO AFTERNOON.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN
BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...EVENSON/RJS
MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 PM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING
ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH
LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL
CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN
FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW
TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO
BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT
ALL.
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...TROPICAL ENVIRONMENT WITH SOUTHEAST FLOW THROUGH 500 MB.
THIS REGIME WILL GIVE US SCATTERED CONVECTION ALONG THE RESULTANT
THIS AFTERNOON. GIVEN THE UPPER FLOW...SEA BREEZE CONVECTION SHOULD
GENERALLY REMAIN INLAND FROM THE COASTAL TERMINALS. MOST OF THE
STUFF WILL BE FAIRLY LOW TOPPED...HOWEVER SCATTERED THUNDER IS
EXPECTED. SOUTHEAST WINDS WILL CONTINUE INTO THE EVENING HOURS.
SUNDAY...SYNOPTICALLY SIMILAR TO TODAY...WITH AFTERNOON THUNDER
PERSISTING.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY
41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY.
JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT
OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE
CAROLINAS.
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING
ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH
LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL
CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN
FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW
TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO
BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT
ALL.
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z.
FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK
FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE
BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST
IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR
CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL
LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING
CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR
DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A
COUPLE OF HOURS BEFORE SUNRISE.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY
41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY.
JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT
OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE
CAROLINAS.
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
716 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z.
FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK
FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE
BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST
IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR
CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL
LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING
CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR
DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A
COUPLE OF HOURS BEFORE SUNRISE.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
701 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE
08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER
POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL
TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000
FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW
SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD
DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE
PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH
CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH
EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT
EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
656 AM EDT SAT AUG 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A
COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL
STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 650 AM SATURDAY...PER EARLIER RUNS OF THE RAP MODEL AND THE
06Z NAM...SCATTERED SHOWERS AND A FEW TSTMS HAVE DEVELOPED IN AN
AREA OF SURFACE MOISTURE CONVERGENCE AND INSTABILITY NEAR THE
COAST AND HAVE MOVED INLAND. HAVE RAISED POPS TO CHC OVER ROUGHLY
THE EASTERN THIRD OR SO OF THE CWA. RAP INDICATES THESE SHOWERS
WILL AROUND FOR ALOT OF MORNING...WITH ADDITIONAL ISOLATED SHOWERS
AND TSTMS THIS AFTERNOON WITH THE SEA BREEZE. NO CHANGES TO
FORECAST TEMPERATURES MAINLY IN THE UPPER 80S TO AROUND 90 TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND
SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING
WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL
HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY
NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD
AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH
WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS
ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY...
SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK
SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR
CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE
IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE
EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE
AROUND MID TO LATE WEEK TIME FRAME.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 7 AM SAT...SOME MVFR FOG HAS DEVELOPED AT ALL OF THE TAF
SITES AND VSBY HAS BEEN BOUNCING UP AND DOWN FOR THE PAST COUPLE
OF HOURS. THIS FOG SHOULD DISSIPATE BY ABOUT 13Z WITH ANOTHER
ROUND OF ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE
AFTERNOON. SIMILAR PATTERN EXPECTED TONIGHT WITH A FEW SHOWERS
DEVELOPING NEAR THE COAST...BUT OVERALL MVFR CONDITIONS EXPECTED
WITH SOME PATCHY FOG TOWARD MORNING ON SUNDAY.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH
AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE
LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT
RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING
TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 7 AM SATURDAY...CURRENT BUOY OBSERVATIONS CONTINUE TO
INDICATE S/SW WINDS OF 12 KNOTS OR LESS WITH SEAS 2 TO 3 FEET WITH
A 7 TO 8 SECOND SWELL COMPONENT. A FEW SHOWERS MOVING ALONG THE
COAST MAY BRIEFLY CAUSE SOME GUSTINESS TO ABOUT 18 KNOTS OR SO. S/SW
WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST
TODAY AND TONIGHT WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE
WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15
KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE
LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS...
AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT
RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE
CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT
AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 330 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO RIDGE
ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC
TROF TO PASS OVER THE BAHAMAS TODAY...AND TRACK NW TO AND ACROSS THE
NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR
SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES
TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY
ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA
BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE
THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY
THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2
INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5
AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL
BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING
THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW TO
EVOLVE THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE
COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE
FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE
08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER
POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL
TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000
FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW
SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD
DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE
PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH
CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH
EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT
EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE FLORIDA PENINSULA SUNDAY. WIND SPEEDS MAY
INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL
BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND
PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE
CLOSER PROXIMITY OF THE EFFECTS FROM THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
329 AM EDT SAT AUG 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A
COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL
STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 3 AM SATURDAY...LATEST RAP MODEL ALONG THE NAM12/GFS SHOW A
THREAT OF SOME SHOWERS AND POSSIBLE TSTMS WILL AFFECT THE COAST
DURING THE EARLY MORNING HOURS AS STRONG MID-LEVEL VORT CENTER
TRACKS UP THE CAROLINA COAST IN AN UPPER-LEVEL WEAKNESS. RADAR
ALREADY SHOWING SOME SHOWERS DEVELOPING ABOUT 100 MILES DUE SOUTH
OF THE CRYSTAL COAST...SO HAVE RAISED POPS TO LOW CHC ALONG THE
COAST THROUGH MIDDAY. ADDITIONAL ISOLATED SHOWERS WITH A FEW TSTMS
MAY OCCUR ALONG THE SEA BREEZE LATER THIS AFTERNOON AND WILL HAVE
A SLIGHT CHC ALONG THE SEA BREEZE ZONE AT THAT TIME. MAX TEMPS
SHOULD MAINLY BE IN THE UPPER 80S TO AROUND 90 UNDER PARTLY CLOUDY
SKIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND
SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING
WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL
HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY
NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD
AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH
WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS
ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY...
SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK
SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR
CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE
IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE
EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE
AROUND MID TO LATE WEEK TIME FRAME.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND
GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY
FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW
WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH
AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE
LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT
RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING
TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 310 AM SATURDAY...WINDS HAVE DROPPED A BIT IN THE PAST
COUPLE OF HOURS AND ARE GENERALLY 12 KNOTS OR LESS FROM THE S/SW
WITH SEAS AT 1 TO 3 FEET WITH 7 TO 8 SECOND SWELLS. NOT PLANNING
ANY MAJOR CHANGES TO MARINE FORECAST AS S/SW WINDS WILL CONTINUE
TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST WITH FRONTAL
BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS
WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET
THROUGH TONIGHT.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE
LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS...
AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT
RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE
CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT
AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 AM EDT SAT AUG 4 2012
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS
HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND
STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM SATURDAY...SIGNALS IN SEVERAL OF THE SHORT-TERM
MODELS INDICATE A DECENT MID-LEVEL SHORTWAVE TO MOVE NORTH ACROSS
EASTERN NORTH CAROLINA IN WEAKNESS BETWEEN AREAS OF HIGH PRESSURE
WELL TO THE EAST AND OVER THE SOUTHERN PLAINS. THE RAP/GFS AND TO
A LESSER EXTENT THE NAM ALL SHOW LIGHT QPF NEAR THE COAST FROM
ABOUT 10Z THIS MORNING INTO EARLY AFTERNOON. HAVE FOLLOWED SUIT
WITH CHANCE POPS NEAR THE COAST TAPERING TO NIL WEST OF HIGHWAY 17
THROUGH EARLY AFTERNOON. NO OTHER MAJOR CHANGES TO THE FORECAST AT
THIS TIME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO
EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE
LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN
THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST
SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS
OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES
OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND
ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON
HOURS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM
AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS
THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME
STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL
DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH
FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH 00Z SUNDAY/...
AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND
GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY
FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S
FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE
AFTERNOON.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE
PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT
NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH
LOCALLY LOWER CEILINGS/VISIBILITIES.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 1 AM SAT...WINDS ARE RUNNING JUST A BIT ABOVE FORECAST
VALUES WITH OBSERVED VALUES NEAR 15 KNOTS AT OREGON
INLET...DIAMOND BUOY AND CAPE LOOKOUT. HAVE UPPED THE WINDS BASED
ON THE LATEST RAP MODEL. SEAS REMAIN IN THE 2 TO 3 FEET RANGE AND
NO CHANGES NEEDED TO THE WAVEHEIGHT FORECAST.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE
AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND.
THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER
MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW
SMALL CRAFT LEVELS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DAG
NEAR TERM...CTC
SHORT TERM...DAG
LONG TERM...HSA
AVIATION...CTC/HSA/JBM
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT SAT AUG 4 2012
.SYNOPSIS...
MUGGY AUGUST AIR THROUGH WEEKEND. WITH A LOCAL DOWNPOUR POSSIBLE.
MORE WIDESPREAD AND ORGANIZED CONVECTION LIKELY SUNDAY...WELL AHEAD
OF COLD FRONT. DRIER AIR TRIES TO CREEP SOUTH MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX
SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE
POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR.
NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT
A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER
STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES
CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS.
EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY
AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH
FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE
STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE
PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES
ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD
EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR
THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE
BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD
TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING.
STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD
MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER
STORMS.
BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN
PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES.
WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW
LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL
REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS
FORECAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
WE ARE HOPING THE PREFRONTAL CONVECTION DOES NOT ORIENT MORE EAST TO
WEST...BUT THE FLASH FLOOD WATCH WAS POSTED EARLY...FOR THAT
POSSIBILITY. AS WE HEAD INTO SUNDAY EVENING...OUR SOUTHERN COUNTIES
SEEM TO BE MORE VULNERABLE TO SOME TRAINING...DESPITE THE 25 TO 30
KNOT CELL MOVEMENT THAT WE ARE EXPECTED.
WILL BASE FORECAST ON SURFACE FRONT FROM NEAR EKN TO CRW TO SOUTH OF
HTS AT 12Z MONDAY. SO HAD TO LEAVE SOME CHANCE POPS ALONG THAT
FEATURE. PICTURING LOW CLOUDS ALONG THAT FRONT TOO. PROBABLY MOSTLY
JUST LINGERING RAIN SHOWERS RATHER THAN THUNDER.
PROBLEM THEN BECOMES...HOW LONG TO LINGER SOME 20/30 POPS IN OUR
EXTREME SOUTH INTO TUESDAY. WE ARE TYPICALLY LEARY OF THE DRIER AIR
IN THE LOW LEVELS MAKING IT THROUGH THE SOUTHERN MOUNTAINS. SO EVEN
THOUGH THE MID LEVELS SHOULD DRY OUT...WILL NOW HOLD ONTO SOME 20/30
POPS IN SW VIRGINIA TO NEAR BECKLEY FOR TUESDAY.
THERE COULD BE WIDESPREAD FOG MONDAY NIGHT FROM EKN TO CRW INTO THE
COAL FIELDS. YET...BEING THE THIRD NIGHT INTO THE FUTURE...WILL HOLD
OFF INCLUDING THOSE SPECIFICS FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
12Z GFS AND 12Z ECMWF SOLUTIONS CONTINUE TO AGREE THAT THE MID LEVEL
RIDGE...BAKING THE PLAINS THIS SUMMER...WILL SLIDE BACK WEST INTO
THE GREAT BASIN...WITH A STRONG TROF SWINGING THROUGH OUR VICINITY
ON DAY 7...WITH THE SURFACE FRONT LIKELY AHEAD OF IT...ON DAY
6/FRIDAY.
PROBLEM FOR WEDNESDAY AND THURSDAY IS THE DEEP MOISTURE LINGERING TO
OUR SOUTHEAST. WILL TRY TO HOLD WEDNESDAY DRY MAINLY FOR COUNTIES
NORTH OF A HTS-CRW-EKN LINE...WITH SOME 20/30 POPS ALONG OUR
SOUTHEASTERN COUNTIES WEDNESDAY. WENT ALONG WITH HPC MEDIUM RANGE
CHANCE POPS FOR THURSDAY AND FRIDAY...WITH A COOL DOWN FOR SATURDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND
ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE
AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO
THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS
POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND
REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED
MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN.
TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND
THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE
FROM WEST TO EAST AS COLD FRONT APPROACHES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY
VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM
OVERNIGHT IF CLOUD BREAKS DEVELOP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H M M H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT.
IFR IN LOW STRATUS POSSIBLE NEAR SURFACE FRONT MONDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR WVZ005-006-013>020-024>040-046-047.
OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR OHZ087.
KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ
SHORT TERM...KTB/ARJ
LONG TERM...KTB
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
225 PM EDT SAT AUG 4 2012
.SYNOPSIS...
WARM AND HUMID...WITH SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
THIS AFTERNOON. A COLD FRONT BRINGS WIDESPREAD AND STRONGER
STORMS...WITH HEAVY RAIN AND SEVERE WEATHER SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX
SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE
POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR.
NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT
A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER
STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES
CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS.
EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY
AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH
FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE
STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE
PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES
ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD
EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR
THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE
BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD
TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING.
STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD
MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER
STORMS.
BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN
PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES.
WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW
LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL
REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS
FORECAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
A COLD FRONT APPROACHES TO SOUTHEAST OH SUNDAY. MODELS ARE IN GOOD
AGREEMENT TIGHTENING THE PRESSURE GRADIENT AND FLOW AT H850 FROM THE
SOUTHWEST...AND BRINGING MOISTURE ADVECTION TO THE AREA EARLY
SUNDAY MORNING. THETA-E VALUES REACHING 340K SUGGEST VERY JUICY
AIR CAPABLE TO PRODUCE HEAVY RAIN AND STRONG STORMS WILL SPREAD
EAST ACROSS WV DURING THE PEAK OF DIURNAL HEATING. THIS MOISTURE
IS ALSO NOTED IN PRECIPITABLE WATER VALUES EXCEEDING 2.2 INCHES.
ALTHOUGH EQUILIBRIUM LEVEL EXCEEDING 40 KFT...A THIN CAPE SOUNDING
AND LOW UNIDIRECTIONAL DEEP LAYERED SHEAR VALUES SUGGEST WATER
LOADING EFFECTS WITH TALL STORMS. THESE CONDITIONS COULD REDUCE
SEVERE UPDRAFTS...BUT WILL PROMOTE VERY HEAVY DOWNPOURS. STRONG
H5 VORTICITY MAXIMUM REACHES SOUTHEAST OH BY MON 00Z...SUGGESTING
GOOD DYNAMICS COULD ENHANCE STORMS DURING THE AFTERNOON HOURS.
THEREFORE...EXPECT CONVECTION FIRING UP AHEAD OF THE FRONT BY MID
DAY SUNDAY...AND SPREAD EAST NORTHEAST...WITH CONTINUING CONVECTION
DEVELOPING ACROSS SOUTHEAST OH WITH THE STRONGER UPPER FORCING
APPROACHING THROUGH THE EVENING.
ALTHOUGH THERE IS A SLIGHT RISK FOR SEVERE STORMS ACROSS THE ENTIRE
AREA...WILL ALSO WATCH FOR WATER PROBLEMS WITH THE AFOREMENTIONED
SCENARIO. KEPT CAP POPS SUNDAY AFTERNOON ACROSS SOUTHEAST
OH...SPREADING EAST THROUGH SUNDAY NIGHT. THE FRONT SEEMS TO SLOW
DOWN AS IT ENTERS WV...AND LINGER ACROSS THE SOUTHERN COAL FIELDS
AND CENTRAL MOUNTAINS THROUGH TUESDAY MORNING.
A FLASH FLOOD WATCH MAY BE REQUIRED FOR SUNDAY.
KEPT HIGH TEMPS IN THE 80S SUNDAY AND MONDAY PER ABUNDANT CLOUDS
AND RAINFALL EXPECTED. KEPT LOWS IN THE LOWER 70S SUNDAY NIGHT PER
ABUNDANT MOISTURE AND LACK OF EXTRA PUSH OF DRIER AIR TO DISPLACE
HIGH DEWPOINTS...BUT IN THE MID 60S MONDAY NIGHT PER CLEARING
SPREADING FROM THE WEST AND ASSOCIATED RADIATIONAL COOLING.
AREAS OF DENSE FOG WILL BE POSSIBLE UNDER CLEAR SKIES AND AREAS
THAT RECEIVE RAINFALL TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GOING WITH HPC. NORTHWEST FLOW ALOFT STRENGTHENS...WITH THE HOT AND
HUMID AIR BEING SHUNTED TO THE SOUTH. TRANQUIL PERIOD OF DRY AND
NEAR SEASONABLE TEMPERATURES DOMINATE THIS PERIOD AS WEAK HIGH
PRESSURE DOMINATES. GOOD MODEL AGREEMENT ON THIS SCENARIO.
BY FRIDAY...NEXT SYSTEM APPROACHES AS THE UPPER FLOW BECOMES MORE
WESTERLY AND ALLOWS THE HEAT AND MOISTURE TO RETURN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND
ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE
AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO
THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS
POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND
REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED
MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN.
TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND
THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE
FROM WEST TO EAST AS COLD FRONT APPROACHES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY
VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM
OVERNIGHT IF CLOUD BREAKS DEVELOP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M H H H M M H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR WVZ005-006-013>020-024>040-046-047.
OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR OHZ087.
KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...ARJ/MZ
NEAR TERM...MZ
SHORT TERM...ARJ
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
637 AM EDT SAT AUG 4 2012
.SYNOPSIS...
SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS
LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER
WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER
LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY
NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY
NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD
INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN
THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING
INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT
ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED
FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS
THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR
FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION.
WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN
ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD
COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY
LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES
DO APPROACH 100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION
AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN
BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER
TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY
DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY
DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS
THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN
IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE
REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL
ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE
DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT
STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE
ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS
OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR
POTENTIAL OF VERY HIGH RAINFALL RATES.
WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO
RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH
POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS
TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL
SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON
HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION.
HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE
AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE.
WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR
SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH
TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY
CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO
OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE
REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED
COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW
SEASONABLE VALUES DURING THE DAY.
THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH
TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW
PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE
WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE
SOUTH...TO THE MID 50S ACROSS THE NORTHEAST.
BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE
OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE
OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE
SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL
THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION
TOWARD THE END OF THE WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SCATTERED CONVECTION WILL BE ONGOING TODAY WITH GENERALLY VFR
CONDITIONS OUTSIDE OF THE PASSING SHOWERS. WINDS WILL PICK UP THIS
AFTERNOON AND A COLD FRONT WILL CROSS THE REGION AROUND THIS TIME
TOMORROW. EXPECT WIND SHIFT AT DAYBREAK TOMORROW WITH MORE
PREVALENT THUNDERSTORMS ALONG AND AHEAD OF IT AS THE LOW LEVEL
MOISTURE TRANSPORT KICKS IN OVERNIGHT.
.OUTLOOK...SHOWERS AND THUNDERSTORMS WILL BECOME MORE LIKELY TONIGHT
AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...JDR
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
452 AM EDT SAT AUG 4 2012
.SYNOPSIS...
SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS
LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER
WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER
LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY
NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY
NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD
INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN
THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING
INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT
ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED
FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS
THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR
FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION.
WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN
ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD
COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY
LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES
DO APPROACH 100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION
AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN
BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER
TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY
DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY
DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS
THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN
IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE
REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL
ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE
DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT
STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE
ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS
OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR
POTENTIAL OF VERY HIGH RAINFALL RATES.
WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO
RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH
POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS
TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL
SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON
HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION.
HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE
AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE.
WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR
SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH
TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY
CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO
OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE
REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED
COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW
SEASONABLE VALUES DURING THE DAY.
THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH
TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW
PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE
WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE
SOUTH...TO THE MID 50S ACROSS THE NORTHEAST.
BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE
OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE
OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE
SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL
THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION
TOWARD THE END OF THE WEEK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS MAY BE INTERRUPTED BY BR TONIGHT IN A HUMID
AIRMASS. SCATTERED CONVECTION TRIGGERED BY WEAK DISTURBANCES IN
AN UNSTABLE REGIME WILL AFFECT TAF SITES ON SATURDAY. WINDS WILL
BE OUT OF THE SOUTH WITH GUSTS NEAR 20 KNOTS SATURDAY AFTERNOON.
.OUTLOOK...SHOWERS AND THUNDERSTORMS ARE LIKELY SATURDAY NIGHT
AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...JDR
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
420 PM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG TO
SEVERE ON SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT
WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE
MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH
INHIBITION DIMINISHING RAPIDLY.
HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS
AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS
AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z.
AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST
AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF
THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN
DAMAGING WINDS.
ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF
THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE
MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL
SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO
OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF
THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF
OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
FROM MID AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS...FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL
REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS
HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 10 PM IN EAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
BY MONDAY MORNING...COLD FRONT WILL BE JUST SE OF CWA. WILL TAKE
SOME TIME TO CLEAR OUT RESIDUAL MOISTURE IN SOUTHEAST. BUT WITH
WESTERLY WINDS...DRIER AIR WILL EVENTUALLY WORK INTO THE BOUNDARY
LAYER IN THE SE. PW FALLS BELOW NORMAL STATE WIDE MONDAY.
CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE KEEPING FORECAST
DRY. WEAK WAVE OVER SE U.S. SLIDES UP THE COAST FOR
WED/THU...NUDGING MOISTURE BACK INTO CWA. SO INTRODUCED SLIGHT
CHANCE FOR A TSTM WED/THU AS HUMIDITY BEGINS TO INCREASE. MORE
POTENT TROUGH APPROACHES IN NW FLOW FOR THU NIGHT-FRI NIGHT.
MODELS HANDLING THIS FEATURE WELL...THOUGH GFS TRIES TO LIFT
TROUGH NORTHWARD. EITHER WAY...CHANCE OF SHOWERS/TSTMS FITS THE
BILL BEFORE A MAINLY DRY WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL TO START THE WEEK...THEN SLOWLY
RISE BACK ABOVE NORMAL FOR MIDWEEK. AS HUMIDITY INCREASES LATE
WEEK AHEAD OF APPROACHING TROUGH...TEMPS AGAIN GET A BIT MUGGY -
EVEN THOUGH THEY REMAIN JUST A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS
SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME
HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND
OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS
FROM STORMS TAKE PLACE.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...RXR
LONG TERM...RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
159 PM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE
MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH
INHIBITION DIMINISHING RAPIDLY.
HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS
AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS
AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z.
AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST
AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF
THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN
DAMAGING WINDS.
ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF
THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE
MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS
SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME
HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND
OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS
FROM STORMS TAKE PLACE.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1053 AM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A
COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING
CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIS AFTERNOON AND
EVENING.
MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON
HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH
CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND
STORMS.
SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE
OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY
OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING
OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED
PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE
UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT
DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF
THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE
MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS
AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC
FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH
PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE
SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG
AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CONDITIONS HAVE IMPROVED TO HIGH MVFR/LOW VFR AS LAST OF THE HAZE
CONTINUES TO THIN OUT.
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED LATER TODAY IN AND
AROUND AN THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND EARLY EVENING...FROM ABOUT 22Z THROUGH 03Z TONIGHT.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/CERU/MARTIN
NEAR TERM...LA CORTE/CERU/MARTIN
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 AM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
STILL SOME PATCHY LOW CLOUDS AND MAINLY THIN FOG THAT WILL BURN
OFF SMARTLY NOW THAT THE SUN IS UP.
MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A
COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING
CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIA AFTERNOON AND
EVENING.
MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON
HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH
CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND
STORMS.
SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE
OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY
OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING
OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED
PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE
UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT
DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF
THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE
MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS
AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC
FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH
PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE
SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG
AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
PATCHY IFR AND LOWER CIGS AND VSBYS WILL CONTINUE THROUGH 14Z THIS
MORNING. LOW STRATO CU WILL SPREAD ACROSS THE LOWER SUSQ...AND
OVER THE NW MTNS. THE CENTRAL PA REGION HAS SEEN THE DEVELOPMENT
OF SOME MID LEVEL CLOUDS. LOW STRATOCU COULD STILL SPREAD OUT
THROUGH 15Z...BEFORE IT AND THE PATCHY FOG DISSIPATES.
IFR IS POSSIBLE IN AND AROUND TSRA THIS AFTERNOON AND EARLY
EVENING DUE TO A STRONGER CHANCE FOR CONVECTION...ESPECIALLY
JST...AOO AND ALONG THE LOWER SUSQ TAF SITES FROM 22Z THROUGH 03Z
TONIGHT.
OUTLOOK...
.SAT-SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...
ESPECIALLY SUNDAY AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/CERU/MARTIN
NEAR TERM...LA CORTE/CERU/MARTIN
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
840 PM CDT SUN AUG 5 2012
.UPDATE...
CONVECTION ACROSS OUR NW COUNTIES JUST AHEAD OF A SOUTHWARD MOVING
SHORTWAVE. FRONTAL BOUNDARY STILL WELL TO THE NORTH ALONG THE
OHIO RIVER. HRRR AND OTHER MODELS CONTINUE TO SHY AWAY FROM
DEVELOPMENT BEHIND THE CURRENT CONVECTION. FURTHERMORE...NUMERICAL
POPS BETWEEN 06Z AND 12Z ARE NOT ALL THAT IMPRESSIVE. THUS...FOR
THE FCST...WILL BE LOWERING POPS ACROSS THE PLATEAU AND FAR
WESTERN AREAS AS WELL(BEFORE 06Z). OTW...POPS IN THE SLT CHANCE TO
CHANCE CATEGORY WILL RESUME AFT 06Z AS THE BOUNDARY WITH THE
DRIER AIR WILL REMAIN NORTH OF THE MID STATE.
AS FOR THE FOG POTENTIAL ACROSS THE WEST...DEWPOINT DEPRESSIONS
ARE RATHER LOW AND NUMERICAL GUIDANCE STILL CARRYING LOW VSBY
LEVELS AT CKV. WILL THEREFORE KEEP THE FOG GOING.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 753 PM CDT SUN AUG 5 2012/
UPDATE...FOR 00Z TAFS.
AVIATION...
ANOTHER TOUGH FORECAST WITH QUESTION OF HOW FAR SOUTH COLD FRONT
JUST NORTHWEST WILL SINK. AIRMASS REMAINS PLENTY MOIST AND UNSTABLE
AND UPSTREAM CONVECTION SHOULD HOLD TOGETHER AND POSSIBLY AFFECT
CKV/BNA THIS EVENING. STORMS ALSO EXPECTED TO AFFECT CSV OVERNIGHT.
VSBYS ALSO LIKELY REDUCED BY FOG LATER TONIGHT. VFR CONDITIONS
MOSTLY MONDAY AS DEEP MOISTURE MOVES SOUTH BUT CSV EXPECTED TO
HAVE BRIEF DECREASE IN CEILING/VSBY FROM PASSING STORMS.
PREV DISCUSSION... /ISSUED 627 PM CDT SUN AUG 5 2012/
UPDATE...
FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND
CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE
CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE
COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT
WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE
TONIGHT.
OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE
ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME
GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM
INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL
BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS...
SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST
RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR
NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW.
PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/
DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF
THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND
PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY
RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND
GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA.
LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED
HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE
DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED
EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE.
WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD
OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE
BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE
MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD
FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY
LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS
THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND
HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS
WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH
THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR
WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY
WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN
WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT.
ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY
DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND
STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL
THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR
NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE
WOULD BE RATHER ISOLATED.
LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL
JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER
MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A
CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE
HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES.
FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID.
LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS
ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE
FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND
MOISTURE CONVERGENCE IS INDICATED.
BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER
MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH
THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT
LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL
FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND
MORE PLEASANT HUMIDITY LEVELS.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
753 PM CDT SUN AUG 5 2012
.UPDATE...FOR 00Z TAFS.
&&
.AVIATION...
ANOTHER TOUGH FORECAST WITH QUESTION OF HOW FAR SOUTH COLD FRONT
JUST NORTHWEST WILL SINK. AIRMASS REMAINS PLENTY MOIST AND UNSTABLE
AND UPSTREAM CONVECTION SHOULD HOLD TOGETHER AND POSSIBLY AFFECT
CKV/BNA THIS EVENING. STORMS ALSO EXPECTED TO AFFECT CSV OVERNIGHT.
VSBYS ALSO LIKELY REDUCED BY FOG LATER TONIGHT. VFR CONDITIONS
MOSTLY MONDAY AS DEEP MOISTURE MOVES SOUTH BUT CSV EXPECTED TO
HAVE BRIEF DECREASE IN CEILING/VSBY FROM PASSING STORMS.
&&
.PREV DISCUSSION... /ISSUED 627 PM CDT SUN AUG 5 2012/
UPDATE...
FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND
CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE
CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE
COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT
WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE
TONIGHT.
OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE
ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME
GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM
INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL
BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS...
SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST
RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR
NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW.
PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/
DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF
THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND
PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY
RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND
GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA.
LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED
HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE
DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED
EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE.
WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD
OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE
BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE
MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD
FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY
LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS
THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND
HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS
WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH
THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR
WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY
WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN
WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT.
ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY
DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND
STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL
THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR
NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE
WOULD BE RATHER ISOLATED.
LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL
JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER
MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A
CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE
HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES.
FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID.
LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS
ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE
FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND
MOISTURE CONVERGENCE IS INDICATED.
BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER
MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH
THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT
LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL
FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND
MORE PLEASANT HUMIDITY LEVELS.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
627 PM CDT SUN AUG 5 2012
.UPDATE...
FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND
CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE
CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE
COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT
WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE
TONIGHT.
OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE
ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME
GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM
INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL
BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS...
SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST
RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR
NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/
DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF
THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND
PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY
RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND
GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA.
LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED
HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE
DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED
EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE.
WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD
OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE
BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE
MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD
FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY
LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS
THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND
HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS
WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH
THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR
WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY
WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN
WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT.
ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY
DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND
STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL
THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR
NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE
WOULD BE RATHER ISOLATED.
LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL
JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER
MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A
CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE
HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES.
FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID.
LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS
ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE
FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND
MOISTURE CONVERGENCE IS INDICATED.
BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER
MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH
THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT
LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL
FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND
MORE PLEASANT HUMIDITY LEVELS.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE APPALACHIANS LATE ON SUNDAY
AND SLOWLY MOVE THROUGH THE REGION ON MONDAY. THIS FRONT WILL
PROVIDE THE TRIGGER FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS...
SOME WITH VERY HEAVY RAINFALL. THE FRONT WILL DRIFT INTO THE
CAROLINAS BY TUESDAY AND DISSIPATE...BUT LINGERING MOISTURE BEHIND
IT WILL ALLOW SOME SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE
THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY/...
AS 0F 205 PM EDT SATURDAY...
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN THE MOIST AND
UNSTABLE AIR ACROSS OUR REGION THIS AFTERNOON. VORT LOBE WILL MOVE
ACROSS THE APPALACHIANS ENHANCING SHOWERS AND THUNDERSTORMS. THE
WRFARW-RNK...HRRR...NAM...RUC AND GFS KEEP SCATTERED STORMS THIS
EVENING INTO TONIGHT. ANY SLOW MOVING THUNDERSTORM MAY PRODUCE HEAVY
RAIN. FLASH FLOOD GUIDANCE IS RUNNING ABOUT 2 INCHES AN HOUR IN THE
MTNS AND 3 INCHES AN HOUR IN THE PIEDMONT. LOCAL FLOODING PROBLEMS
MAY BE A PROBLEM WITH TRAINING OF THUNDERSTORMS.
WITH THE LOW LEVEL FLOW FROM THE SOUTH...EXPECT THE GREATEST
CONVERGENCE ALONG THE BLUE RIDGE MOUNTAINS . SECONDARY AREA OF LOW
LEVEL CONVERGENCE LIKELY TO DEVELOP THIS AFTERNOON INTO THIS EVENING
OVER THE PIEDMONT. BOTH THE RUC AND NAM SHOWED SOME DEVELOPMENT OVER
THE EAST THIS EVENING.
LEANED TOWARDS THE NAM FOR TONIGHT POPS WITH ACTIVITY LINGER WELL
INTO THE OVERNIGHT AIDED BY CONTINUED MOIST LOW LEVEL MOISTURE
TRANSPORT INTO THE AREA UNDERNEATH NEARLY STATIONARY DISTURBANCE
ALOFT. WENT WITH LOWS CLOSE TO THE ADJMETBC WITH READINGS FROM THE
MID 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE SOUTHEAST UNDER A
BLANKET OF CLOUDS AND ELEVATED DEWPOINTS.
UNSETTLED WEATHER WILL CONTINUE ON SUNDAY AHEAD OF APPROACHING
FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY. SOME INCREASE IN SHEAR
AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A BETTER SEVERE POTENTIAL
AS WELL...WITH MORE ORGANIZED CLUSTERS COMING OUT OF OF WV AHEAD OF
FRONT. WITH PWATS INCREASES THERE IS THE POTENTIAL FOR HEAVY RAINS.
MAIN THREAT DURING THE DAY WOULD MAINLY BE IN THE WEST. PLAYED HIGH
TEMPERATURES NEAR COOLER GUIDANCE WITH HIGHS FROM THE UPPER 70S IN
THE MOUNTAINS TO AROUND 90 IN THE SOUTHEAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 345 PM EDT SATURDAY...
COLD FRONT NOT TO ARRIVE UNTIL SUNDAY NIGHT...AND IT MAY BE THAT
BEST CHANCE FOR ORGANIZED CONVECTION...INCLUDING SLIGHT CHC OF
SEVERE AND HEAVIEST RAINFALL RATES...DO NOT ARRIVE UNTIL THE
EVENING. WITH SLOWER TIMING THE SEVERE POTENTIAL MAY BE LIMITED TO
EXTREME WESTERN PORTIONS OF AREA IF IT COMES IN LATE ENOUGH IN
EVENING...BUT HEAVY RAIN IS LOOKING LIKE A BIGGER CONCERN NOW UP
UNTIL AT LEAST MIDNIGHT. CONTEMPLATED FLASH FLOOD WATCH FOR THIS
PERIOD BUT WOULD NOT BE FOR MORE THAN ABOUT 6 HRS AS ANY HIGH RAINFALL
RATES DISSIPATE THROUGHOUT THE EVENING...AND PROBABLY LIMITED TO FAR
WESTERN PORTIONS...WV COUNTIES AND TAZEWELL MAINLY. SOME OF THESE
LOCATIONS HAVE HAD SIGNIFICANT RAINFALL RECENTLY BUT IT`S BEEN HIT
AND MISS. SO FOR NOW DECIDED TO HOLD OFF TO SEE IF FURTHER
GUIDANCE SUGGESTS EITHER AN EARLIER START OR LONGER THREAT TIME
INTO THE OVERNIGHT. INCREASES POPS SUNDAY NIGHT TO LIKELY AND
CATEGORICAL IN WEST.
MILDER OVERNIGHT LOWS MONDAY MORNING WITH EXTENSIVE CLOUD COVER
AND LINGERING PRECIP...AND ALSO COOLER HIGHS MONDAY UNDER SIMILAR
CONDITIONS AS FRONT SLOWLY MOVES ACROSS AREA. WENT SLIGHTLY COOLER
THAN LOWEST GUIDANCE NUMBERS. NOT SURE HOW MUCH INSTABILITY WILL
BE REALIZED FOR CONVECTION...SO MAINLY SHOWERS WITH ONLY SLIGHT
CHC FIRST HALF OF DAY...AND WITH LIKELY POPS ACROSS THE SOUTH BY
LATE IN THE DAY...STILL DOWNPLAYED THUNDER WITH ONLY A CHANCE. BETTER
TSTORM COVERAGE MAY BE WELL SOUTH OF OUR AREA.
BY TUESDAY SOME DIFFERENCES BETWEEN NAM AND GFS ARE EVIDENT...WITH
NAM TAKEING FRONTAL BOUNDARY FARTHER SOUTH...AND GFS WASHING IT
OUT ALLOWING BETTER SOUTHERLY FLOW TO RETURN. NAM HAS MID LEVEL
DRY AIR AND SUBSIDENCE ACROSS THE NORTHERN HALF OF FCST
AREA...SUPRESSING MOST CONVECTIVE THREATS DESPITE MODEST
INSTABILITY...WHEREAS GFS REMAINS MOIST AND HINTS AT WEAK UPPER
WAVE RIDING FROM SW TO NE HELPING TO SPREAD PRECIP BACK TO THE
NORTH AGAIN. COMPROMISED BETWEEN THE TWO BUT WITH A LEAN TOWARD
GFS...WITH SLIGHT CHC POPS ACROSS FAR NORTH BUT LIKELY ACROSS THE
SOUTH. INCREASED CLOUD COVER AND LOWERED HIGHS A BUT AS WELL GIVEN
FAVORED GFS SOLUTION...AGAIN GOING SLIGHTLY COOLER THAN LOWEST
GUIDANCE. THIS HAS SOME BUST POTENTIAL IF NAM IS CORRECT AND
PRECIP STAYS WELL SOUTH AND SOME CLEARING TAKES PLACE FARTHER
NORTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 1245 PM EDT SATURDAY...
DURING THE MID TO LATE PORTION OF THE WEEK...THE FRONTAL BOUNDARY IS
EXPECTED TO STALL ALONG THE SOUTHERN PERIPHERY OF THE FORECAST
AREA...IN RESPONSE TO A SLOWLY DIGGING UPPER LEVEL TROUGH OVER THE
SOUTHERN GREAT LAKES REGION. THE CONSENSUS OF GUIDANCE IS NOT
INDICATING THIS BOUNDARY WILL REMAIN CLOSE ENOUGH TO THE REGION TO
CONTINUE TO PROVIDE A FOCUSING MECHANISM FOR DAILY
CONVECTION...AIDED BY SOME WEAK UPPER LEVEL WAVES MOVING FROM
SOUTHWEST TO NORTHEAST. GENERALLY DURING THE WED/THURS TIME FRAME
THE PRECIP CHANCES WILL BE A LITTLE GREATER ACROSS THE SOUTHEAST
CLOSER TO THE WEAKENING FRONTAL BOUNDARY...BUT AM CONTINUING WITH
LOW TO MID CHANCE POPS FOR ALL LOCATIONS...EXCEPT FOR DIURNAL DROP
TO SLIGHT CHC OVERNIGHT. THEN...AS THE UPPER TROUGH DEEPENS TOWARD
THE END OF THE WEEK...A SECOND WEAK FRONTAL BOUNDARY WILL APPROACH
FROM THE NORTH LATE FRIDAY OR EARLY SATURDAY...INCREASING THE
CHANCES AGAIN FROM THE WEST. SOME MODELS ARE DEEPER WITH THIS TROUGH
THAN OTHERS...AND SUGGEST A BETTER POSSIBILITY THAT THE FRONT WILL
PUSH FARTHER THROUGH THE REGION BY LATE NEXT SATURDAY WITH POTENTIAL
FOR SOME DRYING AND SLIGHTLY COOLER TEMPS. ONLY HEDGING SLIGHTLY
TOWARD THIS IDEA SINCE THE CONSENSUS IN ENSEMBLES IS FOR A WEAKER
TROUGH AND LIFTING NORTHEAST BY NEXT WEEKEND...SO STILL SOME
UNCERTAINTY AS TO WHETHER THIS FRONT WILL REALLY PUSH THROUGH ANY
FARTHER THAN THE ONE FOR EARLIER IN THE WEEK.
WITH FRONTAL BOUNDARY LINGERING THROUGH MID WEEK JUST TO OUR
SOUTH...LOOKS LIKE INSTABILITY MAY BE LIMITED WITH PLENTY OF CLOUD
COVER EXPECTED...SO SEVERE POTENTIAL NOT ESPECIALLY HIGH...BUT
RELATIVELY HIGH MOISTURE CONTENT WITH WEAK CONVERGENCE ALONG OLD
BOUNDARY SUGGESTS A BIT MORE OF A FLASH FLOOD POTENTIAL ALTHOUGH
THIS STILL MUCH DEPENDENT ON GETTING HIGHER RAINFALL RATES.
INCREASED THE CLOUD COVER AND LOWERED HIGH TEMPS SOMEWHAT FROM
PREVIOUS FORECAST FOR WED AND THURS...BUT STILL GOING CLOSE TO
GFS-BASED GUIDANCE. SLIGHT WARMING BY FRIDAY AHEAD OF NEXT FRONTAL
BOUNDARY BUT STILL BORDERLINE IF THERE WILL BE ANY 90S ACROSS THE
PIEDMONT.
TROPICAL ACTIVITY TO MONITOR WITH ERNESTO MOVING TOWARD YUCATAN AND
INTO GULF BY MID WEEK BUT CURRENTLY EXPECTED TO REMAIN WELL SOUTH
AND NOT INFLUENCE THE MID ATLANTIC REGION. A TROPICAL WAVE CURRENTLY
OVER FLORIDA MAY EVENTUALLY EJECT SOME MOISTURE INTO OLD FRONTAL
BOUNDARY TO OUR SOUTH...AND COULD HELP ENHANCE SOME OF THE PRECIP
POTENTIAL BY MID WEEK. TROPICAL STORM FLORENCE WELL OUT IN THE
ATLANTIC LIKELY TO REMAIN WELL AWAY FROM MAINLAND BEFORE WEAKENING.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 1215 PM EDT SATURDAY...
LOW CLOUDS AND CONVECTION WILL HINDER AVIATION OPERATIONS
THIS AFTERNOON INTO TONIGHT. ATMOSPHERE REMAINS VERY MOIST...WITH
UPPER VORT REMAINING ALONG THE APPALACHIANS THIS AFTERNOON.
SCATTERED MVFR SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON
INTO TONIGHT...KEPT VCTS AT TAF SITES UNTIL SUNSET. BELIEVE
THAT BCB AND DAN TAF SITES HAS THE BEST CHANCE OF A THUNDERSTORM.
DAN IS LOCATED BY THE RICHEST MOISTURE COMBINED WITH BEST INSTABILITY
CREATED BY SOLAR HEATING. ANY THUNDERSTORMS THIS AFTERNOON WILL BE
SLOW MOVING AND COULD CONTAIN HEAVY DOWNPOURS. EXPECT AREAS OF FOG
TO DEVELOP OVERNIGHT ESPECIALLY WHERE THUNDERSTORMS OCCUR THIS
AFTERNOON INTO THIS EVENING.
DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF
SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH
DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED
WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY
DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE
FROM OVERNIGHT VALLEY FOG.
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY
MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF
THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF
DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR
MID WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...KK
SHORT TERM...SK
LONG TERM...SK
AVIATION...KK/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT SAT AUG 4 2012
.SHORT TERM...TODAY THROUGH SUNDAY.
STORMS FIRED ALONG BOUNDARY IN MANITOWOC AND WAUPACA COUNTIES THIS
AFTN...AS THE MORNING RUNS OF THE HRRR MODEL INDICATED. CORRIDOR
OF HIGH INSTABILITY FROM S WI INTO THE FAR E PART OF THE STATE AND
CONVERGENCE ALONG BOUNDARIES ENOUGH TO INITIATE DEEP CONVECTION.
MAIN LINE OF SHOWERS AND STORMS...HOWEVER...MOVING INTO THE WEST
PART OF FORECAST AREA. THIS WILL MOVE ACROSS THE AREA LATE THIS
AFTERNOON AND EARLY EVENING PER LATEST RUN OF HRRR. BEST CHANCE OF
SEVERE WILL BE SOUTH OF FORECAST AREA...BUT STILL A THREAT IN THE
EAST-CENTRAL IN UNSTABLE AIRMASS AND INTERACTION OF LOW-LEVEL
BOUNDARIES.
UPPER TROF WILL QUICKLY SWING THROUGH TONIGHT. SMALL CHANCE FOR
LINGERING SHOWERS BEHIND MAIN LINE LATER THIS EVENING.
OTHERWISE...CLEARING SKIES ACROSS MUCH OF AREA. EXCEPTION IS IN THE
FAR NORTH CLOSER TO THE UPPER LOW AND RESIDUAL MOISTURE.
TEMPS TONIGHT AND SUNDAY ARE A BLEND OF MODELS...CLOSE TO
PREVIOUS FORECAST.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY.
MEAN LONGWAVE PATTERN FOR THE EXTENDED FORECAST PERIOD GENERALLY
CHARACTERIZED BY A TROUGH OVER THE OHIO VALLEY AND RIDGE OVER THE
INTERMOUNTAIN WEST. WESTERN GREAT LAKES REGION WILL RESIDE IN
NORTHWESTERLY FLOW REGIME WITH AN OCCASIONAL EMBEDDED SHORTWAVE
DISTURBANCES TRAVERSING THE AREA. TIMING AND INTENSITY OF EMBEDDED
SHORTWAVE DISTURBANCES WITHIN THIS FLOW REGIME ARE TYPICALLY
PROBLEMATIC...THUS FORECAST CONFIDENCE IN THIS REGARD IS LOW TO
MEDIUM. EARLY IN THE WORK WEEK... DAYTIME TEMPERATURES WILL START
OUT ABOVE NORMAL...THEN SLOWLY FALL BACK TO NEAR...OR PERHAPS
SLIGHTLY BELOW NORMAL FOR EARLY AUGUST.
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD EASTWARD ACROSS THE
FORECAST AREA SUNDAY NIGHT INTO MONDAY. WENT ON THE COOLER SIDE
SIDE OF AVAILABLE GUIDANCE WITH RESPECT TO MIN TEMPERATURES SUNDAY
NIGHT GIVEN CLEAR SKIES...LIGHT WINDS AND RATHER DRY DRY AIRMASS.
MONDAY LOOKS LIKE A PLEASANT DAY WITH SUNNY SKIES...RELATIVELY
LIGHT WINDS WITH DAYTIME HIGHS A FEW DEGREES ABOVE NORMAL.
SHORTWAVE DISTURBANCE THEN FORECAST TO HEAD SOUTHEAST ACROSS
SOUTHERN HUDSON BAY MONDAY NIGHT INTO EARLY TUESDAY. ASSOCIATED
COLD FRONT WILL GET SHOVED SOUTHEAST TOWARD NORTHWEST WISCONSIN BY
AROUND 06Z TUESDAY. APPEARS TO BE A PLUME OF HIGHER MID-LEVEL
LAPSE RATES AND MODEST 850 WAA OUT AHEAD OF THIS SYSTEM. HOWEVER
AVAILABLE MOISTURE IS SOMEWHAT LIMITED. THUS...HAVE MAINLY SMALL
CHANCE POPS OVER NORTHWEST COUNTIES OVERNIGHT...THEN CARRY THESE
SMALL POPS SOUTHEAST ACROSS THE AREA TUESDAY MORNING. MAJORITY OF
GUIDANCE SUGGEST THAT FRONT WILL PASS SOUTHEAST OF THE FORECAST
AREA BY ABOUT 18Z TUESDAY WITH CAA TO ENSUE DURING THE AFTERNOON.
WEAK HIGH PRESSURE RETURNS TO THE AREA TUESDAY NIGHT INTO EARLY
WEDNESDAY...WITH NEXT DISTURBANCE ALREADY APPROACHING THE NORTHERN
MISSISSIPPI VALLEY BY WEDNESDAY MORNING. MODEL CONSENSUS SUGGESTS
THIS SYSTEM WILL BE A BIT MORE POTENT AS IT TRAVERSES SOUTHEAST
ACROSS THE FORECAST AREA THURSDAY. OPERATIONAL GFS AND ECMWF ARE A
BIT FURTHER SOUTH WITH STRENGTHENING SURFACE LOW WHILE GEM A BIT
FURTHER NORTH. BOTTOM LINE IS THAT IT LOOKS LIKE THERE WILL BE A
PRETTY DECENT CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON
THURSDAY. BUMPED UP POPS FROM PREVIOUS FORECAST. SOME MODEL
DIFFERENCES ON EVOLUTION OF UPPER TROUGH AND ASSOCIATED SURFACE LOW
THURSDAY NIGHT INTO FRIDAY. SYSTEM DOES APPEARS TO SLOW DOWN
SOMEWHAT AS IT DEEPENS JUST TO THE EAST OF THE FORECAST AREA...THUS
PRECIPITATION COULD VERY WELL LINGER INTO FRIDAY ESPECIALLY OVER THE
EASTERN HALF OF THE FORECAST AREA. CLOUDS...SCATTERED PRECIPITATION
AND NORTHEASTERLY BOUNDARY LAYER FLOW ON FRIDAY WILL LIKELY HOLD
TEMPERATURES MAINLY IN THE 70S.
&&
.AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF
FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR
CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER
40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST-
CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF
STATE.
JKL
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JKL/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...THIS AFTERNOON THROUGH SUNDAY
1225 PM CDT SAT AUG 4 2012
LINE OF MVFR/IFR SHRA/TSRA WILL BE EXITING EAST OF KLSE BY 19Z WITH
ONLY LINGERING -SHRA THRU 20Z. SMALL AREA OF POST-FRONTAL STRATO-CU
IN THE 2500 TO 3500 FT RANGE WILL ROTATE ACROSS THE TAF SITES THRU
ABOUT 21Z...BUT BE PROGRESSIVE WITH DECREASING CLOUDS/CLEARING SKIES
FOR THE LATE AFTERNOON/EVENING HOURS AS A DRIER/COOLER AIRMASS AND
SUBSIDENCE SPREAD ACROSS THE AREA. OF CONCERN IS THE MVFR CLOUD
SHIELD OVER MUCH OF ND/NORTHERN MN...WRAPPED AROUND/BEHIND THE
SFC-850BM LOW. INCREASING NORTHWEST FLOW BEHIND THE DEPARTING
LOW/COLD FRONT WILL ADVECT THIS MOISTURE/CLOUDS SOUTHEAST TONIGHT.
ADDED A PERIOD OF 2500-3000FT CLOUDS/CIGS TO BOTH KRST/LSE FOR THE
LATE EVENING/OVERNIGHT HOURS AS THIS MOISTURE ROTATES ACROSS THE
AREA. DRIER HIGH PRESSURE/ANTI-CYCLONIC FLOW BUILDS INTO THE AREA
FOR SUN. WITH DIURNAL WARMING/MIXING GOOD VFR EXPECTED SUNDAY WITH
ONLY SCT VFR CUMULUS..AND CLOUD BASES RISING THRU THE DAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....RRS
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1055 AM CDT SAT AUG 4 2012
UPDATED NEAR-TERM AND AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
NEAR-TERM...
HAD TO ADJUST TIMING OF CONVECTION INTO AREA PER EXTRAPOLATION OF
IA CONVECTION AND 04/12Z RUN OF HRRR AND RAP. BEGAN PRECIP EARLIER
THIS AFTERNOON AND ENDING EARLIER IN THE EVENING AS FRONT IS
MOVING A BIT FASTER THAN EARLIER ANTICIPATED. BEST SEVERE
PARAMETERS POINT TO THE SOUTH OF THE FORECAST AREA...BUT SHORT-
TERM MODELS INDICATE SCATTERED CONVECTION AHEAD OF MAIN LINE
BEGINNING BY 19Z IN EAST-CENTRAL WI IN CORRIDOR OF INSTABILITY
AND DIFFERENTIAL HEATING. OTHERWISE...MAIN LINE /HEAVIEST RAIN/
EXPECTED TO MOVE THROUGH THE FORECAST AREA BY ABOUT 00Z.
JKL
PREVIOUS SHORT TERM DISCUSSION...
REGARDLESS OF THE SEVERITY OF THE THUNDERSTORMS WE SHOULD GET A
LINE OF STORMS WITH HEAVY RAIN. PRECIPITABLE WATER VALUES OVER 2
INCHES ARE FORECAST DURING THE LATE AFTERNOON AND EARLY EVENING.
THE FRONT SHOULD BE MOVING QUICK ENOUGH TO PREVENT WIDESPREAD
FLOODING BUT WOULD NOT BE SURPRISED IF THERE ARE SOME 1 TO 2 INCH
PER HOUR RAINFALL RATES AND LOCAL URBAN OR SMALL STREAM FLOODING.
AREA SOUTH OF HIGHWAY 29 IS SO DRY THAT THE RAINFALL IS MUCH
NEEDED. THE FRONT WILL EXIT TONIGHT AND THE RAIN WILL END BY
MIDNIGHT IN MOST PLACES. COOLER AND DRIER AIR WILL ARRIVE
OVERNIGHT AND END THE NEED FOR AIR CONDITIONING FOR AWHILE.
"REAL WISCONSIN" SUMMER WEATHER SHOULD RETURN SUNDAY WITH HIGHS IN
THE 70S...LOW HUMIDITIES AND A NICE BREEZE. IT WILL PROBABLY BE THE
NICEST DAY SINCE JUNE 25TH OVER MUCH OF THE AREA.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY.
THE LATEST MEDIUM RANGE MODELS PLACE THE WESTERN GREAT LAKES REGION
WITHIN NW FLOW ALOFT FOR MUCH OF THE NEXT WEEK. SEVERAL SHORTWAVES
WITHIN THIS NW FLOW COULD IMPACT THE REGION...BUT OUTSIDE OF THE
FIRST WAVE ARRIVING MONDAY NIGHT...MODELS DO NOT HAVE A GOOD HANDLE
OF THESE IMPULSES. COULD SEE ANOTHER WAVE DROP INTO THE AREA
WEDNESDAY INTO WEDNESDAY NIGHT AND ANOTHER LATER IN THE WEEK...BUT
MOISTURE WILL BE LACKING WITH EACH SYSTEM. WILL HAVE TO TAKE A
GENERAL BLEND MID-WEEK ONWARD.
SUNDAY NIGHT INTO MONDAY NIGHT...HIGH PRESSURE WILL MOVE FROM THE
CENTRAL GREAT PLAINS TO THE SOUTHERN GREAT LAKES SUNDAY NIGHT.
WINDS LOOK LIGHT ENOUGH FOR DECOUPLING AND WILL SEE MOSTLY CLEAR
CONDITIONS...SO WILL SIDE ON THE COLD SIDE OF GUIDANCE FOR LOW
TEMPS. ON MONDAY...AN AMPLIFYING NORTHERN STREAM SHORTWAVE WILL
DROP A COOL FRONT INTO LAKE SUPERIOR IN THE AFTERNOON. BUT HIGH
PRESSURE WILL STICK AROUND OUR AREA TO GIVE A MOSTLY SUNNY AND WARM
DAY WITH HIGHS IN THE LOW TO MID 80S. THIS FRONT WILL THEN DROP
ACROSS NORTHERN WISCONSIN AND INTO CENTRAL WISCONSIN MONDAY NIGHT.
HARD TO SAY IF THERE WILL BE ENOUGH MOISTURE FOR PRECIP...BUT
POTENTIAL WILL EXIST SO WILL KEEP A SPOTTY MENTION IN THE FORECAST
FOR NORTHERN WISCONSIN.
REST OF THE FORECAST...THE FRONT WILL FINISH CROSSING CENTRAL AND
NORTHEAST WISCONSIN TUESDAY MORNING BEFORE DEPARTING BY THE
AFTERNOON. NOT TO THRILLED WITH PRECIP CHANCES IN THE MORNING...AS
MID-LEVEL MOISTURE WILL HAVE ALREADY PULLED OUT BY THIS POINT. WILL
REMOVE POPS. TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT TO THE UPPER
70S AND LOWER 80S. HIGH PRESSURE WILL DRIFT ACROSS THE REGION
TUESDAY NIGHT BUT THEN WILL BE ANTICIPATING THE NEXT WAVE SWINGING
ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. WILL HAVE SOME
SMALL PRECIP CHANCES OVER THIS PERIOD. MAY HAVE ANOTHER WAVE ARRIVE
FRIDAY INTO SATURDAY...THOUGH AGAIN PRECIP CHANCES LOOK SMALL. WILL
TRY TO REMOVE CHANCES WHERE POSSIBLE UNTIL MODELS GET A BETTER
HANDLE ON THE DETAILS.
&&
.AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF
FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR
CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER
40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST-
CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF
STATE.
JKL
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1003 AM CDT SAT AUG 4 2012
.UPDATE...MAKING CHANGES ON TIMING AS IOWA CONVECTION LOOKS TO BE
OUR SHOW THIS AFTERNOON. HAVE UPPED POPS TO CATEGORICAL AND HAVE
ADDED SEVERE TO THE GRIDS AS WELL. AXIS OF 1000 DCAPE INTO
SOUTHERN WI...WITH WATER VAPOR/RUC COMBO SHOWING SHORTWAVE NE KS
VICINITY SHIFTING NORTHEAST. MID LEVEL LAPSE RATES OF AROUND 7
WITH BUILDING CAPES INTO SRN WI. ONLY THIN CIRRUS TO CONTEND SO
PLENTY OF HEATING. 0-8 KM SHEAR AROUND 50 KNOTS...AND SEEING SOME
40 KNOTS 0-6 KM. 0-1 SHEAR MORE SO- SO...TORNADO THREAT MINIMAL
BUT NON-ZERO. MAIN CONCERN WILL BE FOR DAMAGING WINDS.
PC
&&
.AVIATION/18Z TAFS/...HAVE ADJUSTED TIMING OF CONVECTION BASED ON
TRENDS ACROSS IOWA. LOOKS LIKE AROUND 19Z IN KMSN AND AROUND 21Z
TOWARDS KMKE.
PC
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT AUG 4 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION
AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY.
SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING
TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A
SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM
AND 3AM ON CURRENT PACE.
HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES
AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS
SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING
FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE
INCREASES AHEAD OF TROUGH.
STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE
AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR
INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500
MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE
WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY
UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING
ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING.
IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE
BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED
INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES.
FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL
BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS
TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S.
BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE
AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR
DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000
J/KG.
PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH
DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE
WEST.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND
MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A
FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS
THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER
AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR
NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY.
TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM
MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT
OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION
IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD
SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL.
THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH
CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM.
NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK
WEEK...WITH 80S CONTINUING.
AVIATION/12Z TAFS/...
WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL
EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z
AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY
EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST.
NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN
BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW
CLOUDS/FOG AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
640 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...
640 AM CDT SAT AUG 4 2012
WAVES OF CONVECTION PASSING THROUGH REGION AHEAD OF APPROACHING
UPPER LOW HAVE BEEN A BIT PROBLEMATIC EARLY THIS MORNING. GENERALLY
VFR CONDITIONS PREVAIL EXCEPT IN AREAS OF STRONGER CONVECTION SO
TRIED TO TIME BETTER THUNDERSTORM WINDOWS IN SHORT TERM.
OFF AND ON ACTIVITY LIKELY TO CONTINUE THROUGH MOST OF THE MORNING
THOUGH AND AS UPPER LOW GETS EVEN CLOSER...ASSOCIATED COLD FRONT
WILL BEGIN LIMITING STORM CHANCES...PUSHING THREAT EAST. MESOSCALE
MODELS STILL HINT AT STRONGER STORMS REFORMING THIS AFTERNOON MAINLY
SOUTH AND SOUTHEAST OF TAF SITES SO EXPECT GENERALLY DRYING TREND BY
EVENING AS NORTHWEST WINDS TAKE OVER. SHOULD ALSO SEE CLEARING
TONIGHT AS HIGH PRESSURE BUILDS IN BUT NORTHWEST WINDS BEHIND SYSTEM
SHOULD KEEP THINGS MIXED AND PREVENT ANY FOG.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT SAT AUG 4 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION
AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY.
SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING
TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A
SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM
AND 3AM ON CURRENT PACE.
HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES
AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS
SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING
FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE
INCREASES AHEAD OF TROUGH.
STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE
AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR
INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500
MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE
WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY
UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING
ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING.
IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE
BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED
INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES.
FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL
BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS
TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S.
BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE
AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR
DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000
J/KG.
PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH
DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE
WEST.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND
MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A
FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS
THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER
AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR
NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY.
.TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM
MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT
OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION
IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD
SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL.
.THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH
CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM.
NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK
WEEK...WITH 80S CONTINUING.
&&
.AVIATION/12Z TAFS/...
WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL
EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z
AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY
EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST.
NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN
BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW
CLOUDS/FOG AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...
1120 PM CDT FRI AUG 3 2012
LINE OF CONVECTION CONTINUES TO TRACK EAST ACROSS MN LATE THIS
EVENING...AND THIS WILL IMPACT KRST AND KLSE. AT ITS CURRENT PACE IT
WILL REACH KRST BY 0530Z AND KLSE NEAR 07Z. THE STORMS ARE PACKING
QUITE A BIT OF WIND...EXPECT NORTHWEST GUSTS UPWARDS OF 40 TO 50 KTS
AT KRST...CLOSER TO 40 KTS AT KLSE. THE LINE SHOULD SWEEP EAST OF
KRST BY 09Z AND KLSE BY 11Z.
MORE SHRA/TS WILL MOVE IN LATER SAT MORNING...CONTINUING INTO THE
AFTERNOON...AS A COLD FRONT DRIVES EAST ACROSS THE REGION. NAM12
BRINGS IT ACROSS KRST AROUND 16Z AND KLSE NEAR 18Z. SOME OF THESE
STORMS COULD ALSO BECOME STRONG TO SEVERE...WITH WIND AND HAIL THE
THREATS. THE GREATER THREAT WILL LIKELY BE AT KLSE WHERE TIMING WILL
FAVOR MORE INSTABILITY...AND THUS THE POTENTIAL FOR STRONGER STORMS.
EXPECT MOST OF THE ACTIVITY TO EXIT EAST BETWEEN 21-00Z...WITH A
CLEARING TREND IN THE EVENING AS HIGH PRESSURE OVER THE PLAINS
STARTS TO INFLUENCE THE LOCAL AREA. PRESSURE GRADIENT STAYS
RELATIVELY TIGHT THOUGH...SO THERE MIGHT NOT BE A LOT OF DROP OFF IN
WINDS SAT NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
551 AM EDT MON AUG 6 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHEASTWARD EARLY TODAY.
HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE MIDWEST AND
PROVIDE A DRY START TO THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A QUICK EARLY MORNING UPDATE HAS BEEN ISSUED TO SPEED UP CLEARING
THIS MORNING AS DRIER DEW POINTS ADVECT INTO WESTERN PA FROM OHIO. IN
ADDITION, POP GRIDS HAVE BEEN REDUCED TO SCHC ACROSS THE WV/MD
RIDGES FOR THIS MORNING INTO THE EARLY AFTERNOON.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX
ADVECTING SLOWLY SOUTHEASTWARD FROM EASTERN OHIO INTO NORTH-CENTRAL
WV. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE DEW
POINT GRADIENT, EXTENDS FROM ZANESVILLE TO BUTLER TO DU BOIS. WITH
TDS STILL IN THE UPPER 60S AND ABUNDANT LOW-LEVEL MOISTURE FROM
RECENT RAINFALL, PATCHY FOG HAS DEVELOPED SOUTH AND EAST OF THE
PITTSBURGH METRO. THE BACK EDGE OF THE CLOUD DECK IS REACHING WESTERN
PA WITH CLEARING IN OHIO.
TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP
SOUTHEASTWARD AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA
WITH THE HIGH SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS WILL
ALLOW FOR ANY LINGERING CONVECTION TO PUSH SOUTHEAST OF THE WV/MD
RIDGES. SOME CLEARING WILL OCCUR FROM THE WEST INITIALLY,
FOLLOWED BY SCATTERED CUMULUS DEVELOPING DURING THE LATE MORNING.
THE MOST CLOUD COVERAGE IS ANTICIPATED EARLY FOR AREAS SOUTH OF
THE BOUNDARY. A GENERAL CLEARING TREND IS EXPECTED LATER THIS
AFTERNOON INTO THE EVENING. HIGHS TODAY SIDE WITH THE COOLER MAV
EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV WHERE THE BOUNDARY WILL
BE SLOWER TO CLEAR. WITH CLEAR SKIES AND NEAR CALM WINDS
OVERNIGHT, THIS WILL ALLOW FOR RADIATIONAL COOLING TONIGHT. LOWS
ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING FROM NEAR 50
ACROSS THE I-80 CORRIDOR TO THE UPPER 50S ACROSS NORTH-CENTRAL WV.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE DEEP LAYER OF DRY AIR WILL
REMAIN ACROSS THE AREA AS THE SURFACE HIGH SHIFTS EAST OF THE AREA
ON TUESDAY. WITH THIS IN MIND, ABUNDANT SUNSHINE IS ANTICIPATED.
850MB TEMPS WARMING TO AROUND 16C ON TUESDAY ALONG WITH SUNSHINE
WILL ALLOW FOR HIGHS TO BE AROUND 5 DEGREES ABOVE SEASONAL
NORMALS.
FORECAST UNCERTAINTY BEGINS WEDNESDAY AS THE NEXT FRONTAL BOUNDARY
APPROACHES FROM THE NORTHWEST AND SOUTHWESTERLY WINDS INCREASE
LOW-LEVEL MOISTURE ACROSS THE AREA LATE IN THE DAY. WITH LITTLE
FORCING, INSTABILITY, AND SHEAR, FORECAST IS CLOSEST TO THE COOLER
GFS AND CONSISTS OF SCHC POPS. TEMPS WILL CONTINUE TO BE AROUND 5
DEGREES ABOVE NORMAL FOR HIGHS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON
POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH
AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS
BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON
THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT
THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS
FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE
WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER
CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB
AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C).
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL
PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING
HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT
INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE
LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE
AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO
KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC
FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT
BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR
LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL
DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW
CUMULUS LIKELY BY THE AFTERNOON. FRIES
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH
PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE
GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND
RESTRICTIONS BY THE END OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
417 AM EDT MON AUG 6 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHWARD EARLY TODAY. HIGH
PRESSURE WILL THEN BUILD INTO THE AREA FROM THE MIDWEST AND
PROVIDE A DRY START TO THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX
ADVECTING SLOWLY SOUTHEASTWARD FROM EASTERN OHIO INTO NORTH-CENTRAL
WV. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE DEW
POINT GRADIENT, EXTENDS FROM ALONG A LINE JUST NORTH OF NEW
PHILADELPHIA TO NEW CASTLE TO DU BOIS. SHOWERS THAT HAVE BEEN
CONFINED TO LOCATIONS SOUTH OF THE BOUNDARY ARE QUICKLY COMING TO
AN END THIS MORNING. WITH TDS STILL IN THE LOWER 70S AND ABUNDANT
LOW-LEVEL MOISTURE FROM RECENT RAINFALL, PATCHY FOG HAS DEVELOPED
ACROSS THE AREA. IN ADDITION, FURTHER UPSTREAM SKIES ARE CLEAR, AS
A SURFACE HIGH IS CENTERED ACROSS THE MIDWEST.
TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP SOUTHWARD
AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA WITH THE HIGH
SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS WILL ALLOW FOR ANY
LINGERING SHOWERS AND THUNDERSTORMS TO PUSH SOUTHEAST OF THE
WV/MD RIDGES. SOME CLEARING WILL OCCUR FROM THE WEST INITIALLY,
FOLLOWED BY SCATTERED CUMULUS DEVELOPING DURING THE LATE MORNING.
THE MOST CLOUD COVERAGE IS ANTICIPATED EARLY FOR AREAS SOUTH OF
THE BOUNDARY. A GENERALLY CLEARING TREND IS EXPECTED LATER THIS
AFTERNOON INTO THE EVENING. HIGHS TODAY SIDE WITH THE COOLER MAV
EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV, WHERE THE BOUNDARY
WILL BE SLOW TO CLEAR. THE SKIES WILL CLEAR LATER TODAY AND
TONIGHT AS THE HIGH BECOMES CENTERED OVER THE UPPER OHIO VALLEY.
WITH CLEAR SKIES AND NEAR CALM WINDS, THIS WILL ALLOW FOR
RADIATIONAL COOLING TONIGHT. LOWS ARE CLOSER TO THE COOLER MAV
GUIDANCE, RANGING FROM THE LOWER 50S ACROSS THE I-80 CORRIDOR TO
THE UPPER 50S ACROSS NORTH-CENTRAL WV.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE DEEP LAYER OF DRY AIR WILL
REMAIN ACROSS THE AREA AS THE SURFACE HIGH SHIFTS EAST OF THE AREA
ON TUESDAY. WITH THIS IN MIND, ABUNDANT SUNSHINE IS ANTICIPATED.
850MB TEMPS WARMING TO AROUND 16C ON TUESDAY ALONG WITH SUNSHINE
WILL ALLOW FOR HIGHS TO BE AROUND 5 DEGREES ABOVE SEASONAL
NORMALS.
FORECAST UNCERTAINTY BEGINS WEDNESDAY AS THE NEXT FRONTAL BOUNDARY
APPROACHES FROM THE NORTHWEST AND SOUTHWESTERLY WINDS INCREASE
LOW-LEVEL MOISTURE ACROSS THE AREA LATE IN THE DAY. WITH LITTLE
FORCING, INSTABILITY, AND SHEAR, FORECAST IS CLOSEST TO THE COOLER
GFS AND CONSISTS OF SCHC POPS. TEMPS WILL CONTINUE TO BE AROUND 5
DEGREES ABOVE NORMAL FOR HIGHS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON
POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH
AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS
BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON
THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT
THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS
FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE
WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER
CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB
AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C).
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL
PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING
HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT
INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE
LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE
AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO
KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC
FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT
BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR
LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL
DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW
CUMULUS LIKELY BY THE AFTERNOON. FRIES
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH
PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE
GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND
RESTRICTIONS BY THE END OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
221 AM EDT MON AUG 6 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHWARD EARLY TODAY, WITH
SHOWERS COMING TO AN END THIS MORNING. HIGH PRESSURE WILL THEN BUILD
INTO THE AREA FROM THE MIDWEST AND PROVIDE A DRY START TO THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX
ADVECTING SLOWLY SOUTHEASTWARD FROM SW PA INTO NORTH-CENTRAL WV AND
WESTERN MD. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE
DEW POINT GRADIENT, EXTENDS FROM ALONG A LINE JUST NORTH OF NEW
PHILADELPHIA TO NEW CASTLE TO DUBOIS. REMAINING SHOWERS SOUTH OF
THE BOUNDARY ARE CONFINED MOSTLY TO NORTH-CENTRAL WV. WITH TDS
STILL IN THE LOWER 70S AND ABUNDANT LOW- LEVEL MOISTURE FROM
RECENT RAINFALL, PATCHY FOG HAS BEGUN TO DEVELOP ACROSS THE AREA.
IN ADDITION, FURTHER UPSTREAM SKIES ARE CLEAR, AS A SURFACE HIGH
IS CENTERED ACROSS THE MIDWEST.
TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP SOUTHWARD
AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA WITH THE HIGH
SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS ALLOW FOR SHOWERS AND
THUNDERSTORMS ACROSS TO PUSH SOUTHEAST OF THE WV/MD RIDGES. CUMULUS
WILL DEVELOP TODAY, WITH THE MOST CLOUD COVERAGE EARLY FOR AREAS
SOUTH OF THE BOUNDARY. HIGHS TODAY SIDE WITH THE COOLER MAV
EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV, WHERE THE BOUNDARY
WILL BE SLOW TO CLEAR. THE SKIES WILL CLEAR LATER TODAY AND
TONIGHT AS THE HIGH BECOMES CENTERED OVER THE UPPER OHIO VALLEY.
WITH CLEAR SKIES AND NEAR CALM WINDS, THIS WILL ALLOW FOR
RADIATIONAL COOLING TONIGHT. LOWS ARE CLOSER TO THE COOLER MAV
GUIDANCE, RANGING FROM THE LOWER 50S ACROSS THE I-80 CORRIDOR TO
THE UPPER 50S ACROSS NORTH-CENTRAL WV.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN THE MAIN STORY THROUGH MOST OF
WEDNESDAY. WITH STRONG SUBSIDENCE AND RADIATIVE
COOLING...TEMPERATURES OVERNIGHT MONDAY AND TUESDAY COULD BE BELOW
NORMAL AND INTO THE 50`S. THIS IS CLOSEST TO MAV GUIDANCE THROUGH
THE PERIOD.
MODELS ARE IN DISAGREEMENT ON THE APPROACH OF THE NEXT SYSTEM WITH
THE NAM BRINGING A FRONTAL BOUNDARY/SHORTWAVE ACROSS THE REGION
LATE WEDNESDAY. THIS IS QUICKER THAN THE GFS. AT THIS POINT...WILL
JUST HEDGE WITH SLIGHT CHANCE POPS WITH THE TIMING
INCONSISTENCIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON
POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH
AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS
BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON
THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT
THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS
FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE
WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER
CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB
AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C).
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL
PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING
HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT
INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE
LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE
AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO
KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC
FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT
BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR
LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL
DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW
CUMULUS LIKELY BY THE AFTERNOON. FRIES
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH
PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE
GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND
RESTRICTIONS BY THE END OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1200 AM MDT MON AUG 6 2012
.AVIATION...
06Z TAF CYCLE
SOME LINGERING SHOWERS AND THUNDERSTORMS MAINLY NEAR AND N OF
INTERSTATE 40 FOR A FEW HOURS PAST MIDNIGHT BEFORE MOST OF THEM
DIMINISH. MOST OF THE ACTIVITY WILL NOT BE STRONG ENOUGH TO CREATE
MAJOR AVIATION HAZARDS...THOUGH SOME BRIEF MVFR CONDITIONS POSSIBLE
WITH THE STRONGEST ACTIVITY IN MAINLY CENTRAL AND PERHAPS NE NM.
ALSO A FEW POCKETS OF MVFR OR VERY LOCALLY IFR CIGS AND FOG IN
WETTER NORTHERN MT VALLEYS AND IMMEDIATE E SLOPES OF SANGRE DE
CRISTOS...ESPECIALLY AFTER 09Z UNTIL MID MORN MON. WHILE SOME SHRA
AND TSRA LIKELY TO DEVELOP IN ISOLATED TO SCT FASHION MAINLY ACROSS
N AND W CENTRAL MT REGIONS AFTER 19Z...COVERAGE AND INTENSITY SHOULD
OVERALL BE A LITTLE LESS THAN TODAY. VERY LOCALIZED AND BRIEF MVFR
CIGS STILL POSS WITH STRONGEST STORMS...BUT LESS THAN ON SUN.
43
&&
.PREV DISCUSSION...1024 PM MDT SUN AUG 5 2012...
FIRST ORDER OF BUSINESS WAS TO EXPIRE THE FLASH FLOOD WATCH AT 10
PM. ABX RADAR INDICATED HANDS DOWN OUR BEST STORM CORE PRECIP
TOTALS ACROSS THE WEST TODAY. A FEW AREAS MAY HAVE PICKED UP 4 TO
6 INCHES OF RAIN. ONE SUCH AREA WAS THOREAU WHERE SIGNIFICANT FLASH
FLOODING HAS BEEN REPORTED TODAY.
NOW THE FOCUS IS WHERE ADJUST HIGHEST POPS. CURRENTLY THE RADAR AND
SATELLITE TRENDS FOCUS THE BEST COVERAGE OVER THE NORTHERN MTS AND
STILL SOMEWHAT ALONG THE CONT DVD. THE 01Z HRRR AND 03Z RUC HANDLE
THE CURRENT PRECIP WELL SO HAVE GONE IN THIS DIRECTION ONCE AGAIN
TONIGHT. THEREFORE EXPECTING CURRENT NMRS COVERAGE ACROSS THE NORTH
TO MOVE SLOWLY ESE INTO THE JEMEZ AND SOUTHERN SANGRES AND THE NE
HIGHLANDS. PLACED SCATTERED COVERAGE THERE WITH ISOLD AT BEST FOR
THE REMAINDER OF THE AREA. GUYER
.PREV DISCUSSION...610 PM MDT SUN AUG 5 2012...
.AVIATION...
00Z TAF CYCLE
ANOTHER FAIRLY ACTIVE CONVECTIVE DAY WAS REALIZED TODAY...BUT MAINLY
JUST ACROSS THE NW THIRD OR SO OF THE STATE. THROUGH THIS EVE EXPECT
SCT TO LOCALLY NUMEROUS SHRA AND TSRA AGAIN MOSTLY WEST AND NORTH NM.
STRONGEST STORMS WILL LIKELY ALSO REMAIN MAINLY N AND W WITH
LOCALIZED AND RELATIVELY SHORT LIVED MVFR CIGS AS WELL AS ISOLATED
INSTANCES OF SMALL HAIL ASSOCIATED WITH STRONGER TSRA. TSRA
MENTIONED ONLY IN SAF...LVS AND FMN TO ACCOUNT FOR BEST CHANCE
LOCALES FOR TSRA. OTHERWISE IN AREAS ALREADY WORKED OVER IN WEST OR
OTHERWISE TOO UNLIKELY TO PICK UP A TSRA IN CENTRAL AND E NM EITHER
VCSH MENTIONED OR NOTHING AT ALL.. MOST IF NOT ALL TSRA SHOULD
DISSIPATE BY OR WITHIN A COUPLE HOURS OF MIDNIGHT. WHILE SOME SHRA
AND TSRA LIKELY TO DEVELOP MON MAINLY AFTER 19Z...COVERAGE AND
INTENSITY SHOULD OVERALL BE A LITTLE LESS THAN TODAY.
43
.PREV DISCUSSION...315 PM MDT SUN AUG 5 2012...
AS EXPECTED...SOMEWHAT OF A SLOW START TO THE SHOWER AND THUNDERSTORM
DEVELOPMENT THIS AFTERNOON. PRECIPITABLE WATER VALUES IN THE FLASH
FLOOD WATCH AREA REMAIN ABOUT 120-150 PERCENT OF NORMAL SO NO
CHANGES TO THE ONGOING WATCH. LOW LEVEL GULF MOISTURE COMBINING
WITH MID LEVEL MONSOON MOISTURE PLUME TO GET PWAT VALUES UP THIS
HIGH. STORMS FIRING OVER THE WEST-CENTRAL MTNS ARE MOVING NORTH
AROUND 15 KTS BUT TRAINING OF SHOWERS AND STORMS OVER THE SAME
AREA/DRAINAGE REMAINS THE MAIN CONCERN. DOPPLER RADAR ESTIMATING
OVER 2 INCHES OF RAIN HAVE FALLEN FROM ONE CELL OR CELLS TRAINING
OVER THOREAU IN THE PAST HOUR AND A HALF. ELSEWHERE...STORMS ARE
DEVELOPING OVER THE NORTHERN MOUNTAINS AND SUSPECT THAT STORMS WILL
BEGIN FIRING OVER OTHER MOUNTAIN LOCATIONS SHORTLY...AS MORE
SURFACE HEATING ALLOWS UPDRAFTS TO PUNCH THROUGH THE SUBSIDENCE
INVERSION AROUND 14K FEET AGL.
MODELS ARE IN VERY GOOD TO EXCELLENT AGREEMENT FOR MONDAY...SLIDING
THE CENTER OF THE UPPER LEVEL HIGH OVER NORTHWEST NM. STEERING
LEVEL FLOW GRADUALLY BECOMES NORTH/NORTHWESTERLY OVER THE NORTH
AND NORTHEAST TO EASTERLY OVER THE SOUTHWEST MOUNTAINS. RESIDUAL
MOISTURE WILL COMBINE WITH THE ELEVATED HEAT SOURCES/MOUNTAINS TO
GET SCATTERED SHOWERS AND THUNDERSTORMS GOING MONDAY AFTERNOON.
HIGH RESOLUTION MODELS INDICATING THAT STORMS MOVING SOUTH FROM
THE JEMEZ MOUNTAINS COULD BRING A ROUND OF THUNDERSTORMS TO
BERNALILLO AND THE ALBUQUERQUE METRO AREA EARLY MONDAY EVENING.
AND WITH STORM MOTION BECOMING NORTHWESTERLY MONDAY LATE
AFTERNOON AND EVENING...SHOWERS AND STORMS WILL MOVE OFF THE
SANGRE DE CRISTOS OUT ONTO THE NORTHEAST HIGHLANDS AND PLAINS.
TUESDAY LOOKS VERY SIMILAR TO MONDAY WITH ONE EXCEPTION. AS THE
UPPER HIGH CENTER SHIFTS FAR ENOUGH WESTWARD...NELY FLOW AT ALL
LEVELS DEVELOPS AND BRINGS GULF MOISTURE TO THE NERN PLAINS AND
CENTRAL HIGHLANDS TUESDAY AFTERNOON AND EVENING. THE MOIST NELY
FLOW COMBINES WITH A WEAK WAVE TRANSLATING AROUND THE UPPER HIGH
TO BRING HIGHER STORM CHANCES FROM THE CENTRAL MOUNTAINS EWD
TUESDAY AFTERNOON AND EVENING.
SIMILAR UPPER LEVEL AND SURFACE PATTERN CONTINUES INTO WEDNESDAY.
DRIER MID AND UPPER LEVEL AIR BEGINS TO FILTER INTO CENTRAL AND
SRN NM THURSDAY...WITH THE BEST THUNDERSTORM CHANCES OVER THE NRN
MOUNTAINS. FRIDAY LOOKS...AT THIS POINT...LIKE THE DOWN DAY FOR
THUNDERSTORMS THIS WEEK...OUTSIDE OF THE NRN AND WRN MOUNTAINS BUT WITH
A NELY STEERING LEVEL FLOW IN PLACE...CANNOT RULE OUT SLIGHT
CHANCES/ISOLATED STORMS FOR THE CENTRAL VALLEYS AS STORMS MOVE
SOUTHWESTWARD.
EXCELLENT AGREEMENT IN THE MEDIUM RANGE OPERATIONAL MODELS EXISTS FOR
NEXT WEEKEND. UPPER HIGH REMAINS FAR ENOUGH NORTHWEST OF THE STATE
FOR OCCASIONAL SHORT-WAVES/DISTURBANCES TO ROTATE AROUND THE HIGH CENTER
AND INITIATE A NORTHEAST TO ELY SURFACE FLOW OVER THE REGION...RECHARGING
SFC MOISTURE. THIS NW FLOW ALOFT IS QUITE THE FAVORABLE PATTERN
FOR THE NORTHEAST AND EAST CENTRAL PLAINS. LONG RANGE FORECASTS GET
QUITE INTERESTING. LATEST ECMWF FORECASTS A MAJOR BLOCKING PATTERN
(OMEGA BLOCK) OVER THE GULF OF ALASKA...FORCING A LARGE AND
UNSEASONABLY DEEP CLOSED UPPER LEVEL LOW OVER THE PACNW. THIS
PATTERN WOULD FORCE THE UPPER HIGH BACK OVER THE SRN PLAINS STATES
AND POSSIBLY OPEN THE DOOR FOR A DEEP SOUTHERLY FETCH OF
SUBTROPICAL/TROPICAL MOISTURE INTO THE STATE. WE SHALL SEE.
33
.FIRE WEATHER...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE QUITE NUMEROUS GOING
INTO THE EVENING...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF
NEW MEXICO. THIS BOOST IN STORM COVERAGE AND THE RELATIVELY LARGE
FOOTPRINT OF WETTING RAINS RECEIVED YESTERDAY SHOULD PRECLUDE ANY
FIRE WEATHER CONCERNS THROUGH THE NEAR TERM. BACK DOOR FRONT
ADVANCED TOWARD ARIZONA...AND SHOULD CONTINUE TO PROVIDE SOME
UPSLOPE TO AID IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE
CONTINENTAL DIVIDE. TEMPERATURES HAVE ALSO FALLEN BACK TO MORE
REASONABLE VALUES AND CLOSER TO SEASONAL AVERAGES...ESPECIALLY IN
THE EASTERN PLAINS. THIS ALONG WITH INCREASED CLOUD COVER AND
ANTECEDENT RAIN CONDITIONS HAS KEPT RELATIVE HUMIDITY AT OR ABOVE 30
PERCENT IN THE FORECAST AREA...AND ANY GAP/CANYON WINDS HAVE
DIMINISHED.
GOOD TO EXCELLENT RH RECOVERY CAN BE EXPECTED TONIGHT AND INTO EARLY
MONDAY MORNING. AS HIGH PRESSURE ALOFT REGAINS SOME SYMMETRY OVER
THE FOUR CORNERS...IT WILL STEER FEWER STORMS INTO THE NORTHERN AND
WESTERN MOUNTAINS OF NEW MEXICO ON MONDAY. ONCE THE HIGH NUDGES
NORTHWESTWARD INTO TUESDAY...ANOTHER BACK DOOR FRONT WILL SLIDE INTO
THE NORTHEASTERN PLAINS OF NEW MEXICO. AT THIS POINT...THE
DIRECTIONAL SHIFT IN THE WINDS APPEARS TO BE A PRIMARY IMPACT AS NO
MAJOR INCREASE IN DEWPOINTS IS ANTICIPATED. ANY UPTICK IN STORM
COVERAGE IN THE NORTHEAST ON TUESDAY WOULD BE FAIRLY SUBTLE. FROM
MID WEEK AND THROUGH THE EXTENDED FORECAST PERIOD VERY LITTLE
MOVEMENT OF THE UPPER LEVEL HIGH IS FORESEEN. THIS WILL LIKELY DRIVE
STORMS MOSTLY TO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO
WITH LESS THAN AVERAGE COVERAGE.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1024 PM MDT SUN AUG 5 2012
.UPDATE...
FIRST ORDER OF BUSINESS WAS TO EXPIRE THE FLASH FLOOD WATCH AT 10
PM. ABX RADAR INDICATED HANDS DOWN OUR BEST STORM CORE PRECIP
TOTALS ACROSS THE WEST TODAY. A FEW AREAS MAY HAVE PICKED UP 4 TO
6 INCHES OF RAIN. ONE SUCH AREA WAS THOREAU WHERE SIGNIFICANT FLASH
FLOODING HAS BEEN REPORTED TODAY.
NOW THE FOCUS IS WHERE ADJUST HIGHEST POPS. CURRENTLY THE RADAR AND
SATELLITE TRENDS FOCUS THE BEST COVERAGE OVER THE NORTHERN MTS AND
STILL SOMEWHAT ALONG THE CONT DVD. THE 01Z HRRR AND 03Z RUC HANDLE
THE CURRENT PRECIP WELL SO HAVE GONE IN THIS DIRECTION ONCE AGAIN
TONIGHT. THEREFORE EXPECTING CURRENT NMRS COVERAGE ACROSS THE NORTH
TO MOVE SLOWLY ESE INTO THE JEMEZ AND SOUTHERN SANGRES AND THE NE
HIGHLANDS. PLACED SCATTERED COVERAGE THERE WITH ISOLD AT BEST FOR
THE REMAINDER OF THE AREA. GUYER
&&
.PREV DISCUSSION...610 PM MDT SUN AUG 5 2012...
.AVIATION...
00Z TAF CYCLE
ANOTHER FAIRLY ACTIVE CONVECTIVE DAY WAS REALIZED TODAY...BUT MAINLY
JUST ACROSS THE NW THIRD OR SO OF THE STATE. THROUGH THIS EVE EXPECT
SCT TO LOCALLY NUMEROUS SHRA AND TSRA AGAIN MOSTLY WEST AND NORTH NM.
STRONGEST STORMS WILL LIKELY ALSO REMAIN MAINLY N AND W WITH
LOCALIZED AND RELATIVELY SHORT LIVED MVFR CIGS AS WELL AS ISOLATED
INSTANCES OF SMALL HAIL ASSOCIATED WITH STRONGER TSRA. TSRA
MENTIONED ONLY IN SAF...LVS AND FMN TO ACCOUNT FOR BEST CHANCE
LOCALES FOR TSRA. OTHERWISE IN AREAS ALREADY WORKED OVER IN WEST OR
OTHERWISE TOO UNLIKELY TO PICK UP A TSRA IN CENTRAL AND E NM EITHER
VCSH MENTIONED OR NOTHING AT ALL.. MOST IF NOT ALL TSRA SHOULD
DISSIPATE BY OR WITHIN A COUPLE HOURS OF MIDNIGHT. WHILE SOME SHRA
AND TSRA LIKELY TO DEVELOP MON MAINLY AFTER 19Z...COVERAGE AND
INTENSITY SHOULD OVERALL BE A LITTLE LESS THAN TODAY.
43
.PREV DISCUSSION...315 PM MDT SUN AUG 5 2012...
AS EXPECTED...SOMEWHAT OF A SLOW START TO THE SHOWER AND THUNDERSTORM
DEVELOPMENT THIS AFTERNOON. PRECIPITABLE WATER VALUES IN THE FLASH
FLOOD WATCH AREA REMAIN ABOUT 120-150 PERCENT OF NORMAL SO NO
CHANGES TO THE ONGOING WATCH. LOW LEVEL GULF MOISTURE COMBINING
WITH MID LEVEL MONSOON MOISTURE PLUME TO GET PWAT VALUES UP THIS
HIGH. STORMS FIRING OVER THE WEST-CENTRAL MTNS ARE MOVING NORTH
AROUND 15 KTS BUT TRAINING OF SHOWERS AND STORMS OVER THE SAME
AREA/DRAINAGE REMAINS THE MAIN CONCERN. DOPPLER RADAR ESTIMATING
OVER 2 INCHES OF RAIN HAVE FALLEN FROM ONE CELL OR CELLS TRAINING
OVER THOREAU IN THE PAST HOUR AND A HALF. ELSEWHERE...STORMS ARE
DEVELOPING OVER THE NORTHERN MOUNTAINS AND SUSPECT THAT STORMS WILL
BEGIN FIRING OVER OTHER MOUNTAIN LOCATIONS SHORTLY...AS MORE
SURFACE HEATING ALLOWS UPDRAFTS TO PUNCH THROUGH THE SUBSIDENCE
INVERSION AROUND 14K FEET AGL.
MODELS ARE IN VERY GOOD TO EXCELLENT AGREEMENT FOR MONDAY...SLIDING
THE CENTER OF THE UPPER LEVEL HIGH OVER NORTHWEST NM. STEERING
LEVEL FLOW GRADUALLY BECOMES NORTH/NORTHWESTERLY OVER THE NORTH
AND NORTHEAST TO EASTERLY OVER THE SOUTHWEST MOUNTAINS. RESIDUAL
MOISTURE WILL COMBINE WITH THE ELEVATED HEAT SOURCES/MOUNTAINS TO
GET SCATTERED SHOWERS AND THUNDERSTORMS GOING MONDAY AFTERNOON.
HIGH RESOLUTION MODELS INDICATING THAT STORMS MOVING SOUTH FROM
THE JEMEZ MOUNTAINS COULD BRING A ROUND OF THUNDERSTORMS TO
BERNALILLO AND THE ALBUQUERQUE METRO AREA EARLY MONDAY EVENING.
AND WITH STORM MOTION BECOMING NORTHWESTERLY MONDAY LATE
AFTERNOON AND EVENING...SHOWERS AND STORMS WILL MOVE OFF THE
SANGRE DE CRISTOS OUT ONTO THE NORTHEAST HIGHLANDS AND PLAINS.
TUESDAY LOOKS VERY SIMILAR TO MONDAY WITH ONE EXCEPTION. AS THE
UPPER HIGH CENTER SHIFTS FAR ENOUGH WESTWARD...NELY FLOW AT ALL
LEVELS DEVELOPS AND BRINGS GULF MOISTURE TO THE NERN PLAINS AND
CENTRAL HIGHLANDS TUESDAY AFTERNOON AND EVENING. THE MOIST NELY
FLOW COMBINES WITH A WEAK WAVE TRANSLATING AROUND THE UPPER HIGH
TO BRING HIGHER STORM CHANCES FROM THE CENTRAL MOUNTAINS EWD
TUESDAY AFTERNOON AND EVENING.
SIMILAR UPPER LEVEL AND SURFACE PATTERN CONTINUES INTO WEDNESDAY.
DRIER MID AND UPPER LEVEL AIR BEGINS TO FILTER INTO CENTRAL AND
SRN NM THURSDAY...WITH THE BEST THUNDERSTORM CHANCES OVER THE NRN
MOUNTAINS. FRIDAY LOOKS...AT THIS POINT...LIKE THE DOWN DAY FOR
THUNDERSTORMS THIS WEEK...OUTSIDE OF THE NRN AND WRN MOUNTAINS BUT WITH
A NELY STEERING LEVEL FLOW IN PLACE...CANNOT RULE OUT SLIGHT
CHANCES/ISOLATED STORMS FOR THE CENTRAL VALLEYS AS STORMS MOVE
SOUTHWESTWARD.
EXCELLENT AGREEMENT IN THE MEDIUM RANGE OPERATIONAL MODELS EXISTS FOR
NEXT WEEKEND. UPPER HIGH REMAINS FAR ENOUGH NORTHWEST OF THE STATE
FOR OCCASIONAL SHORT-WAVES/DISTURBANCES TO ROTATE AROUND THE HIGH CENTER
AND INITIATE A NORTHEAST TO ELY SURFACE FLOW OVER THE REGION...RECHARGING
SFC MOISTURE. THIS NW FLOW ALOFT IS QUITE THE FAVORABLE PATTERN
FOR THE NORTHEAST AND EAST CENTRAL PLAINS. LONG RANGE FORECASTS GET
QUITE INTERESTING. LATEST ECMWF FORECASTS A MAJOR BLOCKING PATTERN
(OMEGA BLOCK) OVER THE GULF OF ALASKA...FORCING A LARGE AND
UNSEASONABLY DEEP CLOSED UPPER LEVEL LOW OVER THE PACNW. THIS
PATTERN WOULD FORCE THE UPPER HIGH BACK OVER THE SRN PLAINS STATES
AND POSSIBLY OPEN THE DOOR FOR A DEEP SOUTHERLY FETCH OF
SUBTROPICAL/TROPICAL MOISTURE INTO THE STATE. WE SHALL SEE.
33
.FIRE WEATHER...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE QUITE NUMEROUS GOING
INTO THE EVENING...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF
NEW MEXICO. THIS BOOST IN STORM COVERAGE AND THE RELATIVELY LARGE
FOOTPRINT OF WETTING RAINS RECEIVED YESTERDAY SHOULD PRECLUDE ANY
FIRE WEATHER CONCERNS THROUGH THE NEAR TERM. BACK DOOR FRONT
ADVANCED TOWARD ARIZONA...AND SHOULD CONTINUE TO PROVIDE SOME
UPSLOPE TO AID IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE
CONTINENTAL DIVIDE. TEMPERATURES HAVE ALSO FALLEN BACK TO MORE
REASONABLE VALUES AND CLOSER TO SEASONAL AVERAGES...ESPECIALLY IN
THE EASTERN PLAINS. THIS ALONG WITH INCREASED CLOUD COVER AND
ANTECEDENT RAIN CONDITIONS HAS KEPT RELATIVE HUMIDITY AT OR ABOVE 30
PERCENT IN THE FORECAST AREA...AND ANY GAP/CANYON WINDS HAVE
DIMINISHED.
GOOD TO EXCELLENT RH RECOVERY CAN BE EXPECTED TONIGHT AND INTO EARLY
MONDAY MORNING. AS HIGH PRESSURE ALOFT REGAINS SOME SYMMETRY OVER
THE FOUR CORNERS...IT WILL STEER FEWER STORMS INTO THE NORTHERN AND
WESTERN MOUNTAINS OF NEW MEXICO ON MONDAY. ONCE THE HIGH NUDGES
NORTHWESTWARD INTO TUESDAY...ANOTHER BACK DOOR FRONT WILL SLIDE INTO
THE NORTHEASTERN PLAINS OF NEW MEXICO. AT THIS POINT...THE
DIRECTIONAL SHIFT IN THE WINDS APPEARS TO BE A PRIMARY IMPACT AS NO
MAJOR INCREASE IN DEWPOINTS IS ANTICIPATED. ANY UPTICK IN STORM
COVERAGE IN THE NORTHEAST ON TUESDAY WOULD BE FAIRLY SUBTLE. FROM
MID WEEK AND THROUGH THE EXTENDED FORECAST PERIOD VERY LITTLE
MOVEMENT OF THE UPPER LEVEL HIGH IS FORESEEN. THIS WILL LIKELY DRIVE
STORMS MOSTLY TO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO
WITH LESS THAN AVERAGE COVERAGE.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
GUYER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1040 AM EDT Mon Aug 6 2012
.NEAR TERM [Through Tonight]...
Updated at: 1035am
The main updates this morning were based on a forecast of a rainy
and cloudy day over much of the area. PoPs were bumped up to
categorical in the morning hours where a large area of rain is
located (centered roughly near Lake Seminole). Hourly temperatures
were trended towards the RAP which seemed to initialize quite well
the location of the area of rain as well as the low and mid-level
circulations associated with the lingering tropical wave. This
resulted in high temperatures that were cooler than the previous
forecast - in the mid 80s in many areas - and that may even be a
stretch in areas like Marianna and Bainbridge which could very
well see rain and dense cloud cover for much of the daytime hours.
Therefore, the trends in temperature will be closely monitored in
the event another update is warranted. The only other change was
to add heavy rain wording into the areas with highest PoPs. Our
12z TAE sounding showed very high PWATs around 2.33", which is
close to 130% of normal. Combined with light flow, moist adiabatic
lapse rates, and very deep warm cloud depth over 14,000 feet - the
ingredients are all there for any showers or storms to be
efficient rainfall producers. Bias flags already inidicate that
some of the area radars are underestimating the rain rates in this
tropical environment, so areas that receive persistent heavy
rainfall will need to be closely monitored for localized flooding
potential. Given 3-hr BiasHPE rain estimates already close to FFG
in some areas, and 1-hr values up to 60% of FFG in the areas of
heavier rain, it is certainly within the realm of possibility that
additional rain today will lead to a few spots of flooding. This
threat will be added to the HWO. We could very well see a repeat of
yesterday to the east of the circulation center of the tropical
wave, just displaced slightly further west to account for the
westward drift of the wave. Yesterday there was a substantial amount
of deep convection and thunderstorms that formed near the I-75
corridor in Florida near a low-level convergence zone. It appears
that a similar band of deep convection is beginning to form from
near K40J to the south into offshore areas. This could affect the
eastern portions of our forecast area today, from CTY/40J north to
near VLD, TMA, FZG.
&&
.SHORT TERM [Tuesday Through Wednesday]...
On Tuesday we will still be dealing with the passing trough
mentioned above, and will likely have another waiting in the wings
across eastern Florida. In addition to the surface features, the
upper level trough will expand into the Southeast, providing a bit
more synoptic scale forcing for ascent. These combined will keep
rain chances well above average on Tuesday, and high temperatures
near or just below average. By Wednesday, the surface subtropical
ridge will begin to nose back in from the east and start to shunt
the pesky tropical waves out of the local area. However, it won`t
be until late in the day that the ridge will take hold, and the
upper level trough will remain in place, so we will probably still
have plenty of shower and thunderstorm activity across our western
forecast area. Thus, rain chances will remain above average in
those locations on Wednesday.
&&
.LONG TERM [Wednesday Night through Sunday]...
Not much change from the previous extended package, as our very
atypical summer governed by an unusually steep Upper Level Trof
down the eastern seaboard will continue through the bulk of the
period. This "disturbed pattern" combined with onshore SW flow at
lower levels, and plenty of deep layer Tropical Moisture will keep
rain chances elevated and daytime high temperatures near or slightly
below climo. By the very end of the period (Sunday and Monday), we
could see some slight improvements to the current fcst as the Trof
tries to exit off to the E, but the deep layer moisture might very
well remain entrenched over the region due to very weak forcing, so
PoPs could still remain elevated. Therefore, will likely need to see
a few more model cycles before confidence is high enough to make a
final determination.
&&
.AVIATION [Beginning 12Z Monday]...
With plenty of deep layer moisture combined with a weak low-mid
level circulation moving slowly westward through the CWA today, low
clouds, showers, and thunderstorms will be sct to widespread at the
terminals. With the weakly defined "center" of this circulation
over central portions of the CWA as of early this morning, the best
chances for rain will be at TLH, ABY, DHN, and ECP, with rainfall
already ongoing at TLH and and ABY. VLD has temporarily cleared out,
which should hold off the convection until later this morning or
early this afternoon, but this clearing may also allow for a 1-2 hr
period of Low Cigs and Vis between 12 and 14 UTC. Overall, expect
prevailing MVFR to IFR conditions at most of the Taf sites with the
with periods of VFR conditions possible outside of the convection.
&&
.MARINE...
Showers and thunderstorms will be possible over the next couple of
days as a series of weak tropical waves traverse our waters from
southeast to northwest. Winds and seas will remain below headline
criteria through the period. However, winds will briefly rise to
near cautionary levels as the subtropical ridge noses back in over
our coastal waters Tuesday through Wednesday. Additionally, swells
from Tropical Storm Ernesto will enhance seas beginning on
Wednesday, especially over our western waters.
&&
.FIRE WEATHER...
A generally wet and disturbed pattern will continue across the
Tri-State area for much if not all of the upcoming week. This will
keep afternoon relative humidities well above critical thresholds
through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1028 AM EDT Mon Aug 6 2012
.NEAR TERM [Through Tonight]...
Updated at: 1025am
The main updates this morning were based on a forecast of a rainy
and cloudy day over much of the area. PoPs were bumped up to
categorical in the morning hours where a large area of rain is
located (centered roughly near Lake Seminole). Hourly temperatures
were trended towards the RAP which seemed to initialize quite well
the location of the area of rain as well as the low and mid-level
circulations associated with the lingering tropical wave. This
resulted in high temperatures that were cooler than the previous
forecast - in the mid 80s in many areas - and that may even be a
stretch in areas like Marianna and Bainbridge which could very
well see rain and dense cloud cover for much of the daytime hours.
Therefore, the trends in temperature will be closely monitored in
the event another update is warranted. The only other change was
to add heavy rain wording into the areas with highest PoPs. Our
12z TAE sounding showed very high PWATs around 2.33", which is
close to 130% of normal. Combined with light flow, moist adiabatic
lapse rates, and very deep warm cloud depth over 14,000 feet - the
ingredients are all there for any showers or storms to be
efficient rainfall producers. Bias flags already inidicate that
some of the area radars are underestimating the rain rates in this
tropical environment, so areas that receive persistent heavy
rainfall will need to be closely monitored for localized flooding
potential. Given 3-hr BiasHPE rain estimates already close to FFG
in some areas, and 1-hr values up to 60% of FFG in the areas of
heavier rain, it is certainly within the realm of possibility that
additional rain today will lead to a few spots of flooding. This
threat will be added to the HWO.
&&
.SHORT TERM [Tuesday Through Wednesday]...
On Tuesday we will still be dealing with the passing trough
mentioned above, and will likely have another waiting in the wings
across eastern Florida. In addition to the surface features, the
upper level trough will expand into the Southeast, providing a bit
more synoptic scale forcing for ascent. These combined will keep
rain chances well above average on Tuesday, and high temperatures
near or just below average. By Wednesday, the surface subtropical
ridge will begin to nose back in from the east and start to shunt
the pesky tropical waves out of the local area. However, it won`t
be until late in the day that the ridge will take hold, and the
upper level trough will remain in place, so we will probably still
have plenty of shower and thunderstorm activity across our western
forecast area. Thus, rain chances will remain above average in
those locations on Wednesday.
&&
.LONG TERM [Wednesday Night through Sunday]...
Not much change from the previous extended package, as our very
atypical summer governed by an unusually steep Upper Level Trof
down the eastern seaboard will continue through the bulk of the
period. This "disturbed pattern" combined with onshore SW flow at
lower levels, and plenty of deep layer Tropical Moisture will keep
rain chances elevated and daytime high temperatures near or slightly
below climo. By the very end of the period (Sunday and Monday), we
could see some slight improvements to the current fcst as the Trof
tries to exit off to the E, but the deep layer moisture might very
well remain entrenched over the region due to very weak forcing, so
PoPs could still remain elevated. Therefore, will likely need to see
a few more model cycles before confidence is high enough to make a
final determination.
&&
.AVIATION [Beginning 12Z Monday]...
With plenty of deep layer moisture combined with a weak low-mid
level circulation moving slowly westward through the CWA today, low
clouds, showers, and thunderstorms will be sct to widespread at the
terminals. With the weakly defined "center" of this circulation
over central portions of the CWA as of early this morning, the best
chances for rain will be at TLH, ABY, DHN, and ECP, with rainfall
already ongoing at TLH and and ABY. VLD has temporarily cleared out,
which should hold off the convection until later this morning or
early this afternoon, but this clearing may also allow for a 1-2 hr
period of Low Cigs and Vis between 12 and 14 UTC. Overall, expect
prevailing MVFR to IFR conditions at most of the Taf sites with the
with periods of VFR conditions possible outside of the convection.
&&
.MARINE...
Showers and thunderstorms will be possible over the next couple of
days as a series of weak tropical waves traverse our waters from
southeast to northwest. Winds and seas will remain below headline
criteria through the period. However, winds will briefly rise to
near cautionary levels as the subtropical ridge noses back in over
our coastal waters Tuesday through Wednesday. Additionally, swells
from Tropical Storm Ernesto will enhance seas beginning on
Wednesday, especially over our western waters.
&&
.FIRE WEATHER...
A generally wet and disturbed pattern will continue across the
Tri-State area for much if not all of the upcoming week. This will
keep afternoon relative humidities well above critical thresholds
through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1024 AM CDT MON AUG 6 2012
.UPDATE...
REDUCED/REMOVED RAIN CHANCES WEST OF AN ENID TO OKLAHOMA CITY TO
ATOKA LINE THROUGH 1 PM CDT. ALSO...NUDGED HIGHS UPWARD OVER
NORTHERN OKLAHOMA AND TWEAKED SKY COVER AND WINDS THIS AFTERNOON.
&&
.DISCUSSION...
HOT CONDITIONS WILL AGAIN PREVAIL THIS AFTERNOON WITH LOW CHANCES
FOR SHOWERS AND STORMS MAINLY SOUTHWEST OF AN ALVA TO CHICKASHA TO
ADA LINE.
THROUGH 1 PM CDT...MAINLY HOT AND DRY CONDITIONS ARE EXPECTED.
CONFINED 20 PERCENT RAIN CHANCES TO FAR WESTERN OKLAHOMA AND
PARTS OF WESTERN NORTH TEXAS SOUTH OF A KNOX CITY TO WICHITA FALLS
LINE WHERE LATEST SATELLITE IMAGERY DEPICTED SOME MID LEVEL
CLOUDINESS. LATEST HRRR RUNS SUGGESTED ISOLATED DEVELOPMENT NEAR
I-35...WHICH SEEMS TO BE VERY POORLY HANDLED AS THERE ARE NO
CUMULUS CLOUDS AND WEAK LAPSE RATES IN THESE AREAS.
THIS AFTERNOON AND EVENING...LATEST NAM12 AND HRRR RUNS
INDICATED ISOLATED TO PERHAPS SCATTERED SHOWERS AND STORMS
WILL DEVELOP OVER MAINLY WESTERN AND SOUTHERN OKLAHOMA
AS WELL AS WESTERN NORTH TEXAS. FIRST DEVELOPMENT MAY OCCUR
IN THE 1 TO 3 PM TIME FRAME NEAR A GAGE TO WICHITA FALLS
TO DURANT LINE ONCE CONVECTIVE TEMPERATURES IN THE 95 TO
100 DEGREE RANGE ARE MET. GUSTY WINDS...POSSIBLY SEVERE
OF 60 MPH OR GREATER DUE TO STEEP LOW LEVEL LAPSE RATES
AND DCAPE VALUES AROUND 1500 J/KG...AND LIGHTNING STRIKES WHICH
CAN IGNITE FIRES WILL BE THE MAIN HAZARDS. RAINFALL AMOUNTS
WILL GENERALLY BE LIGHT...THOUGH ONE OR TWO LOCATIONS MAY RECEIVE
0.50 INCH OR MORE. DUE TO FAIRLY WEAK SHEAR...STORMS SHOULD
REMAIN UNORGANIZED AND MOVE SOUTHEAST 15 TO 20 MPH. STORMS WILL
WEAKEN AROUND SUNSET WITH THE LOSS OF DAYTIME HEATING.
HIGHS TODAY SHOULD REACH THE CENTURY MARK OR HIGHER IN
MOST LOCATIONS. WILL BE CLOSE TO HEAT ADVISORY CRITERIA
WITH HEAT INDICES NEAR 105 DEGREES ACROSS WESTERN NORTH
TEXAS AND SOUTHERN OKLAHOMA...BUT HELD OFF WITH ISSUANCE
DUE TO LOW CONFIDENCE.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT MON AUG 6 2012/
AVIATION...
06/12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL. ISOLATED OR
SCATTERED STORMS POSSIBLE TODAY INTO THIS EVENING BUT PROBABILITY
TOO LOW TO MENTION IN THIS ISSUANCE.
UPDATE...
ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER
NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS
FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY
AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA
DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO
CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS
SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY.
PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/
DISCUSSION...
OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW
PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL
BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM
NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A
BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE
IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE
TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER
RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD
RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL
KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY
BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME
INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY
TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE
SLIGHT COOLING TREND INTO NEXT WEEKEND.
ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE...
LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS
ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS
NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY
FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY
OF MID-WEEK TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 102 77 103 78 / 10 10 10 20
HOBART OK 102 74 103 75 / 30 20 20 30
WICHITA FALLS TX 106 79 107 79 / 30 20 20 30
GAGE OK 99 71 102 71 / 30 10 30 30
PONCA CITY OK 102 72 103 74 / 0 10 10 20
DURANT OK 102 76 103 78 / 20 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/03
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
640 AM CDT MON AUG 6 2012
.AVIATION...
06/12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL. ISOLATED OR
SCATTERED STORMS POSSIBLE TODAY INTO THIS EVENING BUT PROBABILITY
TOO LOW TO MENTION IN THIS ISSUANCE.
&&
.UPDATE...
ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER
NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS
FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY
AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA
DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO
CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS
SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY.
&&
.PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/
DISCUSSION...
OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW
PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL
BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM
NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A
BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE
IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE
TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER
RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD
RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL
KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY
BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME
INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY
TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE
SLIGHT COOLING TREND INTO NEXT WEEKEND.
ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE...
LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS
ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS
NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY
FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY
OF MID-WEEK TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 102 77 103 78 / 20 10 10 20
HOBART OK 102 74 103 75 / 30 20 20 30
WICHITA FALLS TX 106 79 107 79 / 30 20 20 30
GAGE OK 99 71 102 71 / 20 10 30 30
PONCA CITY OK 98 72 103 74 / 0 10 10 20
DURANT OK 102 76 103 78 / 20 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/11
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
551 AM CDT MON AUG 6 2012
.UPDATE...
ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER
NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS
FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY
AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA
DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO
CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS
SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY.
&&
.PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/
DISCUSSION...
OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW
PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL
BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM
NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A
BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE
IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE
TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER
RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD
RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL
KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY
BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME
INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY
TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE
SLIGHT COOLING TREND INTO NEXT WEEKEND.
ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE...
LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS
ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS
NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY
FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY
OF MID-WEEK TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 102 77 103 78 / 20 10 10 20
HOBART OK 102 74 103 75 / 30 20 20 30
WICHITA FALLS TX 106 79 107 79 / 30 20 20 30
GAGE OK 99 71 102 71 / 20 10 30 30
PONCA CITY OK 98 72 103 74 / 0 10 10 20
DURANT OK 102 76 103 78 / 20 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/11
AREA FORECAST DISCUSSION
NWS GOODLAND KS
418 PM MDT MON AUG 6 2012
.UPDATE...
ISSUED AT 415 PM MDT MON AUG 6 2012
UPDATED TO INCLUDE THUNDERSTORM CHANCES IN THE WEST. CONVECTION
HAS INITIATED ALONG A SURFACE TROUGH IN NORTHEAST COLORADO. STORM
MOTIONS ARE ALMOST DUE SOUTH SO NOT SURE HOW FAR EAST THESE WILL
BE ABLE TO MOVE THIS EVENING. FURTHERMORE...DEW POINTS ARE QUITE
LOW. FOR THOSE REASONS...LIMITED POPS TO 30 IN THE FAR NORTHWEST
AND 20 ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE
NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST
OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS
NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST
AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE
CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU
FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP
CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD
MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP
POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND
REEVALUATE AS THE AFTERNOON GOES ON.
TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT
THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP
DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT
SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS.
DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE
AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE
LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE
VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V
STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY
THREAT TOMORROW AFTERNOON/EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE
NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE
CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY
NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT
LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW
ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO
THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE
SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD
BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT.
WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT
LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING
HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM
FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND
AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW.
ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN
EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN
20-40 PERCENT CHANCES THROUGH THE EVENING HOURS.
AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK
PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH
THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN
MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA.
WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL
FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK
INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD
BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE
MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE
INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL
VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO
NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST
IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL
GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR.
IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS
START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY
QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH
MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY
THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO
NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND
PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING
UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING
BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS
DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND
GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH
THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT
REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD
COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS
CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO
PICK UP OUR NORMALLY COLDEST SPOTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1152 AM MDT MON AUG 6 2012
EXPECT PRIMARILY VFR CONDITIONS AT KGLD AND KMCK THROUGH THE
EFFECTIVE PERIOD. PRIMARY QUESTION MARK WILL CENTER ON WHAT...IF
ANY...IMPACT CONVECTION WILL HAVE DURING THE OVERNIGHT HOURS.
GUIDANCE CONTINUES TO SUPPORT HIGHER CHANCES FOR CONVECTION AT
KMCK SO WILL CONTINUE VCTS MENTION. HAVE ADJUSTED THE TIMING TO
BETTER COINCIDE WITH THE HIGHEST LIKELIHOOD OF PRECIP. LEFT
MENTION OF PRECIP OUT OF THE KGLD TAF GIVEN THE LOWER PROBABILITY
OF A DIRECT IMPACT. WINDS WILL BECOME LIGHT AND VARIABLE LATE
TONIGHT THROUGH THE END OF THE EFFECTIVE PERIOD AS A SURFACE
TROUGH RESIDES OVER THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 PM MDT MON AUG 6 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE
NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST
OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS
NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST
AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE
CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU
FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP
CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD
MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP
POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND
REEVALUATE AS THE AFTERNOON GOES ON.
TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT
THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP
DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT
SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS.
DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE
AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE
LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE
VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V
STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY
THREAT TOMORROW AFTERNOON/EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE
NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE
CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY
NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT
LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW
ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO
THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE
SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD
BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT.
WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT
LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING
HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM
FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND
AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW.
ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN
EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN
20-40 PERCENT CHANCES THROUGH THE EVENING HOURS.
AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK
PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH
THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN
MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA.
WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL
FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK
INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD
BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE
MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE
INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL
VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO
NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST
IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL
GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR.
IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS
START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY
QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH
MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY
THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO
NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND
PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING
UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING
BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS
DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND
GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH
THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT
REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD
COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS
CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO
PICK UP OUR NORMALLY COLDEST SPOTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1152 AM MDT MON AUG 6 2012
EXPECT PRIMARILY VFR CONDITIONS AT KGLD AND KMCK THROUGH THE
EFFECTIVE PERIOD. PRIMARY QUESTION MARK WILL CENTER ON WHAT...IF
ANY...IMPACT CONVECTION WILL HAVE DURING THE OVERNIGHT HOURS.
GUIDANCE CONTINUES TO SUPPORT HIGHER CHANCES FOR CONVECTION AT
KMCK SO WILL CONTINUE VCTS MENTION. HAVE ADJUSTED THE TIMING TO
BETTER COINCIDE WITH THE HIGHEST LIKELIHOOD OF PRECIP. LEFT
MENTION OF PRECIP OUT OF THE KGLD TAF GIVEN THE LOWER PROBABILITY
OF A DIRECT IMPACT. WINDS WILL BECOME LIGHT AND VARIABLE LATE
TONIGHT THROUGH THE END OF THE EFFECTIVE PERIOD AS A SURFACE
TROUGH RESIDES OVER THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
414 PM CDT MON AUG 6 2012
.DISCUSSION...
OVERVIEW...ABOVE NORMAL TEMPS EXPECTED TOMORROW BEFORE SHOWERS AND
STORMS ON WEDNESDAY KICK START A COOLING TREND THAT WILL LAST THROUGH
THE WEEKEND. RAIN CHANCES ON THURSDAY AND FRIDAY ARE BASED ON TWO
INDEPENDENT FEATURES. INCREASED POPS DURING THIS TIME FRAME.
CERTAINLY A NON ZERO CHANCE OF PRECIP TONIGHT IN WESTERN WI AND IN
FAR SOUTHERN MN. A COUPLE RUNS OF THE HRRR AND THE RAP BOTH
HIGHLIGHT THESE AREAS WITH SHOWERS LATE THIS EVENING. SEEING THE
EFFECTS OF THE COLD FRONT STRETCHED OUT ACROSS NORTHERN MM.
GETTING NEAR SURFACE CONVERGENCE SHOWING UP IN THE MESO ANALYSIS
BUT ALSO PRETTY OBVIOUS JUST BASED ON THE LOW LEVEL FLOW. NICE
BAND OF CUMULUS AND EVENED EMBEDDED SHOWERS VISIBLE THIS
AFTERNOON. SECONDLY...SUBTLE SHORTWAVE ENERGY IN THE EASTERN
DAKOTAS ALSO DROPPING SOUTH THIS AFTERNOON. NOT MUCH BEING
REFLECTED IN THE SHORT TERM HEIGHT/VORTICITY FIELDS...BUT
DEFINITELY SOMETHING APPARENT ON THE WATER VAPOR. IN
GENERALLY...TRIMMED THE POPS BACK TONIGHT. POP VALUES WERE ALREADY
LOW...IN THE 20-30%...BY LIMITED THE AREAL EXTEND OF THE POPS
COMPARED TO THE PREVIOUS FORECAST. THINK A VAST MAJORITY OF THE
FORECAST AREA REMAINS DRY EVEN WITH THE WEAK FRONTAL PASSAGE.
WONDERING IF THE HIGH DEWPOINT BIAS OFF THE RAP IS PLAYING INTO
THE EXTRA PRECIP TONIGHT.
REALLY CAN NOT SEE HOW MUCH DIFFERENT TOMORROW WILL BE COMPARED
TO TODAY IN TERMS OF TEMPERATURES. IT MIGHT BE A DEGREE OR TWO
COOLER THAN TODAY...BUT 70-80% OF THE GUIDANCE HAS FORECAST 2M
TEMPS AND 850MB TEMPS VERY SIMILAR TO WHAT WAS SEEN TODAY. STILL
LOOKS GOOD FOR AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY WITH SHORTWAVE ROTATING AROUND THE RIDGE OVER THE NEXT
36-48HRS. SHEAR IS MARGINAL WITH RELATIVELY WEAK MID LEVEL
FLOW...BUT FORCING AND INSTABILITY SHOULD NOT BE A PROBLEM...SO
LIKELY POPS ARE NOT A STRETCH AT THIS POINT. WE BLEED THE POPS
INTO THURSDAY DUE TO THE UPPER LOW DROPPING SOUTH OUT OF THE
INTERIOR OF CANADA...NOW IN NORTH CENTRAL CANADA BETWEEN 70-75
NORTH. THIS SYSTEM HAS PROBABLY TRENDED A LITTLE BIT SLOWER AND
STRONGER WITH TIME OVER THE LAST COUPLE DAYS. THERE IS NOT MUCH
RECOVERY IN TERMS OF INSTABILITY...BUT COOL TEMPS ALOFT SUGGESTS
SHOWERY ACTIVITY WITH EMBEDDED THUNDER. COOLED TEMPS ON
THURSDAY...MIGHT BE HARD TO GET MUCH ABOVE 75 IN SOME LOCATIONS IN
CENTRAL MN AND WI WITH CLOUD COVER AND SHOWERS.
&&
.AVIATION.../18Z TAF ISSUANCE/
ONLY ITEM OF INTEREST THIS TAF PERIOD IS THE PASSAGE OF A COLD
FRONT THIS EVENING...THAT SHOULD COME THROUGH WITHOUT MUCH MORE
THAN A WIND SHIFT. MAIN SHORTWAVE DRIVING THIS FRONT IS GOING
ACROSS LAKE SUPERIOR NOW...WHICH MEANS THERE IS LITTLE UPPER
SUPPORT FOR PRECIP THIS FAR SOUTH. THIS COMBINED WITH THE STILL
DRY ATMO AFTER FRIDAY NIGHTS FROPA AND WEAK CONVERGENCE ALONG THE
FRONT SHOULD MAKE IT TOUGH TO GET MUCH ACTIVITY GOING. CAN NOT
RULE IT OUT...BUT CONFIDENCE/COVERAGE IN PRECIP NOT HIGH ENOUGH TO
INCLUDE A VC MENTION. FOR THE WIND SHIFT OVER TO THE
NORTH...FOLLOWED LAV TIMING...WHICH HAS GOOD AGREEMENT WITH THE
HRRR/RAP/SREF.
KMSP...FRONT WILL SLIP THROUGH THE MSP AREA BETWEEN 6Z AND
8Z...WITH WINDS VEERING OVER TOWARD THE NORTH BEHIND IT. BEST SHOT
FOR SEEING STORMS WOULD BE BETWEEN 5Z AND 9Z...BUT NOT EXPECTING
MUCH COVERAGE IF ANYTHING DOES DEVELOPED...SO REMOVED THE VCSH.
OUTSIDE OF THAT...WILL BE ANOTHER QUIET PERIOD.
/OUTLOOK/
.WEDNESDAY...VFR WITH MVFR/TSRA POSSIBLE. WINDS SE AT 5-10 KTS.
.THURSDAY...MVFR CLOUDS AND SHRA DURING THE DAY...BECOMING VFR
OVERNIGHT. WINDS N AT 10G15 KTS.
.FRIDAY...VFR. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/MPG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EDT MON AUG 6 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST THIS
EVENING....WILL DRIFT EAST ACROSS THE CAROLINAS AND SOUTHERN
VIRGINIA TONIGHT THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 PM MONDAY...
A WEAK COLD FRONT WEST OF THE MOUNTAINS WILL STALL FROM EASTERN TN
TO NORTHERN VA THIS EVENING...WHILE THE ASSOCIATED UPPER SHEAR AXIS
SLIPS EAST INTO CENTRAL NC. CONVECTION HAS DEVELOPED ALONG A
DIFFERENTIAL HEATING NEAR THE NC/VA BORDER FROM WIDESPREAD CLOUD
COVER THAT HAS BEEN DRIFTING ALONG AND EAST OF THE FRONTAL
ZONE...AND ALSO OVER SOUTHEAST NC AND COASTAL SC. THE COVERAGE OF
SHOWERS AND STORMS WILL INCREASE FROM THE WESTERN PIEDMONT TO THE
NORTHERN COASTAL PLAIN BY 21Z...AND THEN SLOWLY PUSH EAST ACROSS THE
PIEDMONT THIS EVENING AS THE SHEAR AXIS MOVES OVER THE AREA. MLCAPE
HAS BEEN LIMITED TO LESS THAN 1000 J/KG OVER MOST OF CENTRAL NC THUS
FAR...AND WEAK MID LEVEL FLOW HAS THE 0-6KM EFFECTIVE SHEAR WELL
BELOW 20KT. WITH VERY LITTLE DOWNDRAFT CAPE AND SOUNDINGS BECOMING
INCREASINGLY MOIST ADIABATIC DUE TO PW VALUES OF OVER 2 INCHES...THE
SEVERE THREAT IS LOW THIS EVENING OUTSIDE OF A MORE INTENSE STORM
WILL A PRECIP LOADED DOWNBURST. SOME MINOR FLASH FLOODING IS
POSSIBLE...MAINLY IN URBAN AREAS THIS EVENING AS FLASH FLOOD
GUIDANCE IS RELATIVELY HIGH AREAWIDE.
TONIGHT...
AS THE RIBBON OF VORTICITY ASSOCIATED WITH THE SHEAR AXIS SETTLES
INTO CENTRAL NC TONIGHT...SOME OF THE CAMS ALONG WITH THE HRRR SHOW
THE FOCUS FOR PRECIP SETTING UP ALONG OR JUST WEST OF US HWY 1.
WEAK LAPSE RATES ALOFT AND LIMITED INSTABILITY...COVERAGE SHOULD
DECREASE AFTER MIDNIGHT...BUT SCATTERED SHOWERS AND A FEW ISOLATED
STORMS WILL BE POSSIBLE OVERNIGHT. LOWS IN THE LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 320 PM MONDAY...
THE UPPER LEVEL SHEAR AXIS AND AXIS OF HIGHER PW WILL SHIFT SLIGHTLY
EAST ON TUESDAY...AND WITH IT THE FOCUS FOR GREAT COVERAGE OF
SHOWERS AND STORMS. CONDITIONS WILL BE VERY SIMILAR TO TODAY WITH
WEAK INSTABILITY AND SHEAR...BUT HIGH PW AND RELATIVELY SLOW
MOVEMENT OF CELLS...WHICH WILL LEAD TO MAINLY AN ISOLATED FLASH
FLOODING THREAT. ONE FEATURE TO NOTE IS AN AREA OF CONVECTION OVER
THE FL PANHANDLE AND ITS ASSOCIATED VORT MAX...WHICH MODELS SHOW
BEING DRAWN NORTH ACROSS GA AND SC ON TUESDAY. THE GFS HAS THE MOST
AGGRESSIVE NORTHWARD TRACK AND BRINGS IT ACROSS THE NC COASTAL
PLAIN LATE TUESDAY NIGHT INTO WEDNESDAY. HOWEVER...THERE IS TOO
MUCH MODEL SPREAD TO PUT MUCH FAITH IN HOW IT MIGHT IMPACT
CONVECTION TUESDAY NIGHT. FOR NOW...WE WILL CONTINUE TO SHOW 70-80
POPS ACROSS THE EAST TUESDAY AFTERNOON...TRENDING DOWNWARD TUESDAY
NIGHT BUT WITH AT LEAST CHANCE POPS OVERNIGHT. UNDER MORE
WIDESPREAD CLOUD COVER...HIGHS SHOULD BE A FEW DEGREES COOLER THAN
TODAY...AND MOST GUIDANCE GIVES LOW TO MID 80S. LOWS TUESDAY NIGHT
IN THE UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH THURSDAY NIGHT: THE MID/LOW LEVEL TROUGH WEAKENS
AND STALLS OVER THE EAST COAST ON WEDNESDAY...BRINGING THE BEST
CHANCES FOR PRECIP FROM THE COASTAL PLAIN EASTWARD. THE REMNANTS OF
THE SURFACE TROUGH WILL MOVE OFFSHORE WEDNESDAY NIGHT AND THURSDAY
AHEAD OF OUR NEXT LOW PRESSURE/FRONTAL SYSTEM. THIS SHOULD YIELD A
BREAK IN THE PRECIPITATION WEDNESDAY NIGHT AND INTO THURSDAY...WITH
MORE SHOWERS AND THUNDERSTORMS POSSIBLE THURSDAY AFTERNOON AND INTO
THURSDAY NIGHT. HAVE TRENDED MORE TOWARD THE MAV FOR TEMPS...HIGHS
WEDNESDAY IN THE MID 80S WITH LOWS OVERNIGHT IN THE UPPER 60S TO LOW
70S. HIGHS THURSDAY SLIGHTLY WARMER...MID TO UPPER 80S WITH
OVERNIGHT LOWS IN THE LOW 70S
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 320 PM MONDAY...
A COLD FRONT ASSOCIATED WITH AN ANOMALOUSLY STRONG LOW PRESSURE
SYSTEM WILL IMPACT CENTRAL NC AT THE END OF THE WEEK. THE UPPER
LEVEL LOW IS EXPECTED TO DEVELOP OVER CANADA ON WEDNESDAY AND TRACK
SOUTH AND EAST THROUGH MICHIGAN EARLY FRIDAY AND DEEPEN AS IT MOVES
OVER THE GREAT LAKES INTO THE WEEKEND. HAVE MAINLY GONE WITH A BLEND
OF THE ECMWF AND THE 12Z GFS AS THEY ARE IN FAIRLY GOOD AGREEMENT
AND SEEM TO HANDLE THE LOW PRESSURE SYSTEM THE BEST. THE COLD FRONT
ASSOCIATED WITH THIS SYSTEM SHOULD MOVE INTO THE AREA AROUND MID DAY
FRIDAY...BRINGING WITH IT THE POTENTIAL FOR STRONG TO SEVERE STORMS
TO DEVELOP. THE 12Z GFS GENERATES 1500-2000 J/KG OF SURFACE BASED
CAPE OVER CENTRAL NC FRIDAY AFTERNOON...0-6 KM BULK SHEAR VALUES OF
30-40 KTS...MID LEVEL LAPSE RATES OF 6-7 DEGREES C/KM...AND
PRECIPITABLE WATER VALUES OVER 2 INCHES. BOTH MODELS SHOW THE MAIN
PRECIP AXIS MOVING THROUGH CENTRAL NC FROM THE NW THROUGH APPROX 12Z
SATURDAY. THE FRONT COULD THEN LINGER OVER THE COAST THROUGH THE END
OF THE WEEKEND...LEADING TO A CONTINUED CHANCE FOR SHOWERS AND
STORMS OVER THE COASTAL PLAIN DURING THAT TIME. EXPECT HIGHS IN THE
MID TO UPPER 80S THROUGH SUNDAY...WITH SLIGHTLY COOLER TEMPS FOR
MONDAY...LOW TO MID 80S. OVERNIGHT LOWS RANGING FROM THE UPPER 60S
TO LOW 70S THROUGH THE END OF THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 140 PM MONDAY...
MOSTLY 3-4K FT CEILINGS ARE CURRENTLY OBSERVED ACROSS CENTRAL NC
WITH A FEW AREAS OF SHOWERS AND ISOLATED THUNDERSTORMS NEAR
KGSO/KINT AND NORTH OF KRDU. A COLD FRONT WILL PUSH INTO WESTERN NC
THIS EVENING BUT CONTINUE TO WEAKEN AND WASH OUT OVER CENTRAL NC BY
TUESDAY. SHOWERS AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS
ALONG THE WEAK FRONT. WHERE SHOWERS ARE HEAVIEST...STRONG GUSTY
WINDS AND IFR...OR LOWER.... CEILINGS/VSBYS WILL BE POSSIBLE. THE
TIMING OF THESE SHOWERS AND STORMS IS DIFFICULT TO PIN DOWN...BUT
THE BEST TIME FRAME APPEARS AFTER 20Z TODAY AND INTO THE OVERNIGHT
HOURS...POSSIBLY DIMINISHING FROM WEST TO EAST AFTER MIDNIGHT. IFR
CEILINGS MAY THEN DEVELOP BY 09Z...WITH MODELS SHOWING THE GREATEST
PROBABILITY AT KGSO AND KINT.
SHOWERS AND STORMS ARE EXPECTED TO DEVELOP ALONG THE REMNANTS OF THE
FRONT ON TUESDAY...WITH THE GREATEST COVERAGE OVER EASTERN NC. ANY
MORNING STRATUS SHOULD LIFT BUT MAY HOLD AT OR JUST BELOW 3K FT
GIVEN THE MOIST AIRMASS IN PLACE.
OUTLOOK...
THE THREAT FOR SCATTERED...MAINLY AFTERNOON AND EVENING SHOWERS AND
T-STORMS...WILL RETURN THURSDAY AND FRIDAY. IN ADDITION THERE WILL
BE THE LIKELIHOOD OF SUB-VFR FOG AND CEILINGS DURING THE PRE-DAWN
THROUGH EARLY MORNING HOURS EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM..SMITH
SHORT TERM...SMITH/KMC
LONG TERM...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
305 PM EDT MON AUG 6 2012
.SYNOPSIS...
A FRONT WILL REMAIN STATIONARY TO THE NORTHWEST OF THE
REGION...AND THIS WILL ALLOW FOR A MOIST AND UNSTABLE AIR MASS TO
REMAIN IN PLACE THROUGH THE END OF THE WEEK. A SECOND FRONT WILL
APPROACH THE AREA AND BECOME STATIONARY ALONG THE COAST THIS
WEEKEND. THERE IS A CHANCE OF THUNDERSTORMS AND SHOWERS EACH DAY
WITH THE BEST CHANCES ARE TUESDAY AND THIS WEEKEND.
&&
.NEAR TERM /THROUGH 6 AM TUESDAY/...
AS OF 300 PM MONDAY...THE FORECAST SETUP IS QUITE SIMILAR TO
YESTERDAY. SURGE OF TROPICAL MOISTURE HAS LEAD TO A BAND OF SHOWERS
ALONG THE COAST...MAINLY INITIATED BY LL CONVG. THIS AREA OF RAIN IS
BEING ADVECTED FURTHER INLAND WHILE CELL MOTION IS TO THE NORTHEAST.
THE ACTUAL SEABREEZE HAS HAD VERY WEAK RADAR SIGNATURE TODAY AND IS
BETTER DEMARCATED IN VIS SAT IMAGERY...TO THE EAST OF WHICH CLOUD
COVER IS VERY MUCH DECREASED. SIMILAR TO YESTERDAY THE VERY NEAR
TERM FORECAST WILL SHOW THE WET WEATHER CONTINUE TO DRIFT WESTWARD
AND START TO DIMINISH WITH THE DIURNAL CYCLE. THE HRRR PERFORMED
QUITE WELL YESTERDAY AND HAS THIS LINE BECOME MUCH MORE BROKEN BY
22Z AND EVEN MORESO TOWARDS SUNSET. SOME QUESTION AS TO WHETHER OR
NOT PRECIP DEVELOPS OVER WATER DURING THE OVERNIGHT HOURS. MODEL
GUIDANCE NOT TOO EXCITED ABOUT THE PROSPECT BUT THE SLIGHT CHANCE
POPS FROM THE PREVIOUS FORECAST SEEMS PLAUSIBLE ENOUGH.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...WITH STATIONARY FRONT BACK TO THE WEST AND DEEP
MOISTURE IS IN PLACE OVER THE AREA...CONDITIONS CONTINUE TO FAVOR A
GOOD CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE REGION TUESDAY
AND WEDNESDAY. THE MODELS ARE INDICATING A SHORT WAVE TO CROSS THE
REGION ON TUESDAY AND WITH THIS LIFT SHOULD ENTICE THE DEVELOPMENT
OF RAIN FOR THE ENTIRE COUNTY WARNING AREA. THE MEAN STORM MOTION
IS FROM THE SOUTHWEST JUST BELOW 10 KNOTS AND WITH SOME HEAVY
DOWNPOURS EXPECT THE FLOW MAYBE QUICK ENOUGH TO HOLD OFF THE
CHANCES FOR ANY TYPE OF FLOODING ON TUESDAY. THE SOUTHWEST WINDS
ALOFT PATTERN HOLDS UP INTO WEDNESDAY SO EXPECT CHANCES OF RAIN
TO CONTINUE.
TEMPERATURES ARE EXPECTED REMAIN IN THE MID TO UPPER 80S AND LOWS
IN THE MIDDLE 70S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...PATTERN ALOFT WILL REMAIN AMPLIFIED THROUGH
THE PERIOD WITH RIDGING OVER THE WEST AND TROUGHING OVER THE EAST.
EARLY IN THE PERIOD TROUGHING IS ON THE WEAK SIDE...BUT IMPRESSIVE
SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE WESTERN RIDGE WILL
DRIVE A COLD FRONT INTO THE SOUTHEAST AND HELP AMPLIFY THE 5H
TROUGH OVER THE WEEKEND. WITH 5H TROUGH AXIS REMAINING OVER THE OH
AND TN VALLEYS GULF MOISTURE WILL CONTINUE TO STREAM INTO THE
REGION. COLD FRONT STALLS ACROSS THE AREA SUN THEN STARTS TO WASH
OUT MON. DEEP MOISTURE...DIVERGENCE ALOFT...DIURNAL HEATING...AND
CONVERGENCE ALONG THE SEA BREEZE AND PIEDMONT TROUGH/COLD FRONT
WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHEST POP DURING THE PERIOD WILL LIKELY BE SAT...THOUGH
WEAK SHORTWAVES THU AND/OR FRI COULD PRODUCE SIGNIFICANT COVERAGE.
TEMPERATURES WILL BE WITHIN A DEGREE OR TWO OF CLIMO THROUGH THE
PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...CONVECTION FIRING ALONG THE RESULTANT THAT WILL PUSH
WESTWARD WITH TIME...SLOWER THAN YESTERDAY DUE TO THE SOUTHWEST FLOW
ALOFT. LOOK FOR THE SHOWERS AND ISOLATED THUNDERSTORMS TO END AROUND
22Z...WITH MAINLY VFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT
HOURS. TIME HEIGHT INDICATES MID AND HIGH CLOUDS WILL BE ON THE
INCREASE AS A FRONTAL BOUNDARY THAT HAS BEEN JUST WEST OF THE REGION
FOR SEVERAL DAYS FINALLY MOVES IN. TUESDAY...AGAIN A MID OR HIGH
CLOUD CEILING WITH SCATTERED CONVECTION AROUND. MAINLY SOUTHWEST
FLOW THROUGH THE PERIOD...MORE SOUTHERLY ALONG THE COAST.
EXTENDED OUTLOOK...MVFR/IFR VSBYS AND LOW CEILINGS FROM BR/FG
POSSIBLE EACH MORNING WITH DAILY THREAT FOR DIURNALLY DRIVEN
CONVECTION EACH DAY.
&&
.MARINE...
AS OF 1030 AM MONDAY/THROUGH TONIGHT/...THE PRESSURE GRADIENT OVER
THE LANDMASS WILL BE QUITE LIGHT THROUGH THE PERIOD. HIGH PRESSURE
ACROSS THE WEST AND CENTRAL ATLANTIC WILL STILL BE THE DOMINANT WIND
AND WAVE MAKER THEN. A SOUTH TO SOUTHWESTERLY WIND WILL BE CAPPED AT
JUST 10KT. WIND WAVES IN THE 2 TO 3 FT RANGE WILL BE COMPRISED OF
BOTH THE LIGHT WIND WAVE AND SOME 9 SEC SWELL ENERGY.
SHORT TERM /6 AM TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTH TO SOUTHWEST WINDS OF 10 TO 15 KNOTS WILL
CONTINUE OVER THE WATERS THROUGH THE PERIOD AS A STATIONARY FRONT
REMAINS INLAND THROUGH THE PERIOD. SEAS WILL REMAINS AROUND 3 FEET
WITH AN INCREASE TO 4 TO 5 FEET AT 20 MILES OFF THE COAST LATE
WEDNESDAY EVENING. THIS WILL BE RELATED TO AN INCREASE IN THE
SOUTHERLY WINDS.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHWEST FLOW CONTINUES THROUGH THE
PERIOD...THOUGH WITH SPEEDS INCREASING AS A COLD FRONT APPROACHES
THE REGION FROM THE NORTHWEST. WINDS 10 TO 15 KT THU INTO THU
NIGHT INCREASE TO 15 TO 20 FRI AND FRI NIGHT AS GRADIENT TIGHTENS
UP AND LOW LEVEL JET DEVELOPS. FRONT MOVES INTO THE REGION SAT
RELAXING PRESSURE GRADIENT AND SHIFTING STRONGEST LOW LEVEL
JETTING NORTH AND EAST. THIS WILL ALLOW WINDS TO DROP BACK CLOSER
TO 15 KT. SEAS 2 TO 4 FT THU WILL BUILD WITH INCREASING WINDS FRI
AND FRI NIGHT. ISOLATED 6 FT MAY DEVELOP WELL AWAY FROM THE COAST.
HEADLINES ARE POSSIBLE FOR BOTH FRI AND FRI NIGHT...BUT LOW
CONFIDENCE WHETHER IT WILL BE SCA OR SCEC. REDUCTION IN WINDS
SAT/SAT NIGHT ALLOWS SEAS TO DROP BACK INTO THE 2 TO 4 FT RANGE
WITH SOME ISOLATED 5 FT POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/MBB
SHORT TERM...HAWKINS
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
305 PM CDT MON AUG 6 2012
.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...CONVECTION THIS
AFTERNOON HAS DIMINISH AS THE SEA-BREEZE MOVES INLAND. MAIN
THINKING IS THAT THE BEST DYNAMICS REMAIN TO THE SOUTH WHERE A
STRONGER VORTICITY MAX SHOWS UP IN THE RUC ANALYSIS...AND BIT
STRONGER CAP IS HOLDING ON ACROSS OUR REGION. WITH THE LOSS OF
HEATING LATE THIS EVENING...PRECIPITATION WILL REMAIN LOW AND HAVE
KEPT MENTION OUT OF THE FORECAST. DECENT MOISTURE IN PLACE
EXPECTED TO STAY AROUND FOR TOMORROW TO KEEP SLIGHT CHANCE OF
PRECIPITATION...BEGINNING OVER THE COASTAL WATERS TUESDAY MORNING
THEN AFTERNOON CONVECTION AGAIN FOR THE AFTERNOON HOURS. COULD SEE
A BIT OF LOWER VISIBILITIES WILL BE POSSIBLE JUST BEFORE SUNRISE
GIVEN THE LIGHT WINDS...HIGH DEW POINT VALUES AND GENERALLY CLEAR
SKIES. HOWEVER...CONFIDENCE REMAINS LOW ON FOG DEVELOPMENT
OVERNIGHT. AFTERNOON TEMPERATURES WILL ONCE AGAIN RUN ABOVE
GUIDANCE/SEASONAL AVERAGES. OVERALL...A PERSISTENT FORECAST FROM
WHAT WE HAVE SEE THE PAST FEW DAYS...JUST A BIT LESS IN THE WAY OF
CONVECTION WITH LACK OF MID/UPPER LEVEL SUPPORT.
&&
.LONG TERM (WEDNESDAY THROUGH MONDAY)...CONCUR WITH THE
DETERMINISTIC GFS/ECMWF AND GFS ENSEMBLE MEAN THAT THE UPPER RIDGE
WILL CONTINUE TO MOVE TOWARD THE NW BEFORE BECOMING QUASI-
STATIONARY. SUFFICIENT MOISTURE/INSTABILITY WILL CONTRIBUTE TO ISOLD
CONVECTION PRIMARILY OVER THE NERN SECTIONS/ADJACENT MSA
WEDNESDAY/THURSDAY. THE FOREGOING MODELS PROG AN UPPER DISTURBANCE
TO MOVE ACRS THE CNTRL/NRN PLAINS WEDNESDAY/THURSDAY WHICH WILL
CONTRIBUTE TO A WEAK FRONTAL BOUNDARY WHICH MAY ENTER CNTRL/SRN TX
FRIDAY/SATURDAY (ALONG WITH ASSOCIATED HIGH PW VALUES OWING TO MSTR
CONVERGENCE.) FURTHER...BASED ON THE CURRENT ERNESTO FCST TRACK...
THE NRN EDGE OF COPIOUS MSTR FROM ERNESTO EXPECTED TO ENTER THE
CWA/MSA COMMENCING LATE THURSDAY. THUS WILL MAINTAIN AT LEAST ISOLD
CONVECTION FRIDAY/SATURDAY. NOT CONFIDENCE ENOUGH TO FCST PCPN
SUNDAY/MONDAY. NO SIGNIFICANT CHANGE TO TEMPS DRG THE PERIOD EXCEPT
FOR SLIGHT DECREASE IN RESPONSE TO ERNESTO MSTR. ANTICIPATE MAX HEAT
INDEX VALUES AROUND 105F DRG THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 96 77 95 75 / 10 20 10 10 10
VICTORIA 73 95 75 95 74 / 10 20 10 20 10
LAREDO 78 102 79 102 79 / 10 10 10 10 10
ALICE 74 100 74 99 74 / 10 20 10 10 10
ROCKPORT 79 91 79 89 78 / 20 20 10 20 10
COTULLA 74 101 75 101 75 / 10 10 10 10 10
KINGSVILLE 74 98 76 97 75 / 10 20 10 10 10
NAVY CORPUS 79 90 80 88 80 / 10 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
RG/82...SHORT TERM
WC/87...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1221 PM CDT MON AUG 6 2012
.AVIATION...
CONCERNS THROUGH SUNSET WILL BE ISOLATED STORM DEVELOPMENT AND
BACKING OF WINDS FROM WSW TO SELY BY 00Z TUESDAY.
WEAK SHORTWAVE CONTINUES TO DROP SWD ACROSS E TX WITH A WEAKENING
MORNING STORMS OCCURRING BETWEEN KSLR AND KPSN. ALL TERMINALS ARE
JUST OUTSIDE OF THE HIGH CLOUD CANOPY WILL LIKELY SEE DIFFERENTIAL
HEATING AND AGEOSTROPHIC LIFTING PROCESSES AS THE AFTERNOON
PROGRESSES. THERE ARE INDICATIONS FROM THE RAP AND NORMAN WRF
MODELS THAT ISOLATED STORMS WILL BECOME MORE EVIDENT BY MAX
HEATING OR MID AFTERNOON. WITH A VERY MOIST AND TROPICAL AIRMASS IN
PLACE...PRECIP LOADING COULD RESULT IN GUSTY DOWNBURSTS IN EXCESS
OF 40 KTS POSSIBLE. ONLY DIFFERENCE IS WACO WILL LIKELY SEE THEIR
BEST POTENTIAL LATER IN DAY...BETWEEN 21Z-01Z.
OTHERWISE...VFR FORECAST CONTINUES WITH LIGHT SWLY FLOW BECOMING
SELY BY SUNSET...THEN SWLY BY DAYBREAK TUESDAY.
05/
&&
.UPDATE...
A WEAK BOUNDARY REMAINS ACROSS THE NORTHEASTERN ZONES AT MIDDAY.
THE MAIN CHANGE TO THE FORECAST WAS TO ADD ISOLATED THUNDERSTORMS
TO THE WEST WHERE THE HIGH RESOLUTION RAPID REFRESH IS SHOWING
SOME THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON. HAVE ALSO
ADJUSTED THE HOURLY TEMPERATURES IN THE NORTHEAST WHERE CLOUD
COVER AND EARLIER PRECIPITATION HAVE SLOWED THE WARM UP.
58
&&
.PREV DISCUSSION... /ISSUED 413 AM CDT MON AUG 6 2012/
NORTH TO NORTHWEST FLOW ALOFT WILL REMAIN OVER NORTH TEXAS THROUGH
THE WEEK AS UPPER LEVEL HIGH PRESSURE REMAINS CENTERED NEAR THE
FOUR CORNERS REGION. THIS PATTERN WILL RESULT IN SEASONALLY HOT
TEMPERATURES AND SOME LOW RAIN/THUNDERSTORM CHANCES THROUGH MUCH
OF THE WEEK.
A WEAK COLD FRONT THAT HAD MOVED INTO NORTH TEXAS ON SUNDAY
WAS LOCATED NEAR A SHERMAN TO SULPHUR SPRINGS LINE EARLY THIS
MORNING. THIS FRONT IS PROGGED TO SLOWLY BACKDOOR THE EASTERN
COUNTIES OF NORTH TEXAS THROUGH TUESDAY. THE FRONT WILL CONTINUE
TO ACT AS A FOCUSING MECHANISM FOR SCATTERED SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS.
THERE IS ALSO A SMALL CHANCE THAT SOME SHOWERS AND THUNDERSTORMS
COULD MOVE ACROSS THE WESTERN AND NORTHERN PORTIONS OF NORTH TEXAS
DURING THE OVERNIGHT/MORNING HOURS TONIGHT THROUGH THURSDAY
MORNING...AS AFTERNOON CONVECTION ACROSS THE CENTRAL PLAINS MOVES
SOUTH/SOUTHEAST DURING THE OVERNIGHT HOURS. FOR NOW WE WILL KEEP
ALL POPS LOW WITH ONLY WEAK FORCING EXPECTED AND A VERY DRY
SOLUTION FROM THE ECMWF.
UPPER LEVEL HIGH PRESSURE WILL BUILD BACK TO THE EAST BY THE
WEEKEND WHICH SHOULD DECREASE RAIN CHANCES DUE TO INCREASED LARGE
SCALE SUBSIDENCE.
HIGH TEMPERATURES THROUGH THE WEEK WILL RANGE FROM THE MIDDLE 90S
TO AROUND 101 WITH OVERNIGHT LOWS FROM THE MIDDLE 70S TO NEAR 80.
THE ONLY LOCATIONS THAT WILL SEE AFTERNOON HEAT INDEX VALUES UP TO
106 WILL BE THE EASTERN ZONES DUE TO SLIGHTLY BETTER MOISTURE.
THEREFORE...WILL KEEP THE HEAT ADVISORY THROUGH TUESDAY JUST FOR
THE EXTREME EASTERN COUNTIES OF NORTH TEXAS. HOWEVER...OVERNIGHT
LOWS MAY BE SLIGHTLY SHY OF REACHING CRITERIA IN SOME SPOTS.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 102 80 101 79 101 / 20 20 10 20 20
WACO, TX 100 77 102 80 100 / 20 20 10 10 20
PARIS, TX 98 76 99 75 98 / 20 20 10 10 20
DENTON, TX 102 77 102 76 101 / 20 10 10 20 20
MCKINNEY, TX 99 76 99 76 99 / 20 20 10 20 20
DALLAS, TX 101 82 101 80 100 / 20 20 10 20 20
TERRELL, TX 100 76 100 76 98 / 20 20 20 20 20
CORSICANA, TX 100 76 100 76 99 / 20 20 20 10 20
TEMPLE, TX 101 76 100 76 99 / 20 10 10 20 20
MINERAL WELLS, TX 101 78 101 78 102 / 10 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR TXZ107-122-123-135-
146>148-160>162-174-175.
&&
$$
05/58
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT MON AUG 6 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
305 PM CDT MON AUG 6 2012
MAIN FORECAST CHALLENGES ARE ON RAIN CHANCES TONIGHT AND EARLY
TUESDAY AND AGAIN WEDNESDAY THROUGH THURSDAY.
18Z SURFACE ANALYSIS SHOWS HIGH PRESSURE STRETCHING FROM NORTHERN
ILLINOIS INTO SOUTHERN LOWER MICHIGAN. VISIBLE SATELLITE IMAGERY
SHOWING CLEAR SKIES ACROSS THE ENTIRE UPPER MIDWEST AND GREAT LAKES
REGION.
06.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...SHORTWAVE TROUGH WILL ROTATE ACROSS LAKE SUPERIOR
TONIGHT...PUSHING A WEAK SURFACE TROUGH THROUGH THE FORECAST AREA.
MODELS SHOWING LOW LEVELS TO REMAIN RELATIVELY DRY WITH MOISTURE AT
OR ABOVE 800MB. MID LEVEL INSTABILITIES IN THE ORDER OF 400 J/KG
TO 800 J/KG ARE PROGGED OVER THE AREA AS THE TROUGH DROPS SOUTHWARD
OVERNIGHT. 06.12Z NAM GOING DRY TONIGHT...WHILE GFS SHOWS SOME
LIGHT QPF. VARIOUS MESO MODELS ALSO DIFFERING...WITH THE 06.14Z
HRRR DEVELOPING CONVECTION IN THE HIGHER CAPE AREA OVER CENTRAL
SOUTHERN MINNESOTA AND THE 06.12 NMM EAST KEEPING THINGS DRY UNTIL
AFTER 09Z. WITH THESE DIFFERENCES WILL CONTINUE THE LOWER END
PROBABILITIES FOR TONIGHT AND JUST ACROSS THE SOUTH ON TUESDAY.
HIGH PRESSURE THEN BUILDS ACROSS THE AREA TUESDAY NIGHT...BUT THIS
WILL BE QUITE TRANSITORY AS NEXT SHORTWAVE IN THE NORTHWEST FLOW
DROPS QUICKLY THROUGH THE DAKOTAS AND THIS WILL SPREAD SOME MID AND
HIGH LEVEL CLOUDS INTO THE AREA AFTER MIDNIGHT...BUT THE AREA WILL
REMAIN DRY.
MODELS HAVE BEEN PRETTY CONSISTENT IN THE WEDNESDAY THROUGH THURSDAY
TIME FRAME. MID LEVEL TROUGH DIGS ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY REGION...WITH AN INCREASE IN MOISTURE TRANSPORT INTO THE
AREA. ISENTROPIC LIFT INCREASES LATE WEDNESDAY...WITH THE MAIN RAIN
CHANCES WEDNESDAY NIGHT. GFS INDICATING BETTER INSTABILITIES TO
REMAIN TO THE SOUTH OF THE AREA. LIFT CONTINUES FOR MUCH OF THURSDAY
AS TROUGH AXIS REMAINS JUST WEST OF THE AREA. SYSTEM THEN BEGINS TO
PULL AWAY THURSDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD
SOUTHWARD.
.LONG TERM...FRIDAY THROUGH MONDAY
305 PM CDT MON AUG 6 2012
NORTH TO NORTHWEST FLOW WILL CONTINUE ACROSS THE AREA THROUGH THE
PERIOD. EXITING TROUGH WILL CONTINUE TO DEEPEN OVER THE GREAT LAKES
AND MOVE EASTWARD FRIDAY INTO SATURDAY...WHILE HIGH PRESSURE
DOMINATES THE WEATHER FOR THE LOCAL AREA. THE HIGH WILL SLIDE OFF TO
THE EAST SATURDAY NIGHT...ALLOWING FOR MOISTURE RETURN ON ITS
BACKSIDE AHEAD OF THE NEXT SHORTWAVE/SURFACE TROUGH. GFS MUCH DEEPER
WITH THIS FEATURE...WHILE 06.12Z ECMWF IS MUCH WEAKER AND EVEN DRY
IN ITS QPF FIELDS. SYSTEM THEM DROPS SOUTH WITH QUIET WEATHER
EXPECTED INTO MONDAY. WITH THE NORTHWEST FLOW...TEMPERATURES WILL BE
RATHER PLEASANT AVERAGING AT OR BELOW NORMAL.
&&
.AVIATION...
600 PM CDT MON AUG 6 2012
THERE APPEARS TO BE TWO FOCUSES FOR AN ISOLATED SHRA/TS TONIGHT.
FIRST IS NORTH WITH A SFC FRONT/TROUGH MOVING SOUTHWARD ACROSS THE
REGION. SOME FRONTOGENETIC FORCING AND WEAK MLCAPE AROUND THE
BOUNDARY. DECENT PUSH OF 850 MB MOISTURE VIA THE RAP. THE HRRR AND
NAM12 POP SOME CONVECTION ALONG THE BOUNDARY...BUT ITS MOSTLY
CONFINED ACROSS NORTHERN WI TONIGHT.
THE OTHER FOCUS IS ANOTHER SFC BOUNDARY WITH ACCOMPANYING LOW AROUND
THE IA/MN BORDER. SOME 900-700 MB FRONTOGENETIC FORCING INDICATED IN
THE RAP...ALONG WITH MLCAPES UPWARDS OF 3000 J/KG THIS EVENING. THE
HRRR AND NAM12 ALSO DEVELOP SOME ISOLATED SHRA/TS DUE TO THIS
FORCING...AND THIS ACTIVITY WOULD HAVE THE BETTER CHANCE OF
IMPACTING KRST/KLSE. IT SHOULD BE NOTED THAT MOST OF THE SATURATION
INDICATED FOR THE FORCING TO WORK ON IS MOSTLY MID TO UPPER LEVEL.
BASES ON ANY SHRA/TS COULD BE 8-10 KFT. RELATIVELY DRY NEAR SFC
LAYER COULD ENHANCE ANY GUSTINESS AROUND A STORM...OTHERWISE IMPACTS
VIA CIGS/VSBY LOOK MINIMAL AT THIS TIME.
CONFIDENCE NOT HIGH...BUT ENOUGH SUPPORT FROM THE VARIOUS MESO
MODELS TO CONTINUE THE VCSH MENTION AT KRST/KLSE FOR A PERIOD
TONIGHT.
FRONT TO THE NORTH WILL SLIDE THROUGH TUE MORNING...SWITCHING THE
WINDS TO THE NORTHWEST. HIGH PRESSURE WILL FOLLOW IN ITS WAKE...WITH
QUIET VFR CONDITIONS THEN INTO TUE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT MON AUG 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...JLR
LONG TERM....JLR
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
321 PM CDT MON AUG 6 2012
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM
INFLUENCE OF SURFACE HIGH WANES WITH SURFACE TROUGH APPROACHING
FROM NRN MN. CLEAR FOR MUCH OF THE NIGHT. 4 KM WRF MODEL NUDGES
PRECIP FROM SE MN INTO EXTREME SW WI LATE TONIGHT AS DOES
GFS...THOUGH FOCUSING BOUNDARY STILL BACK TO THE NORTHWEST. LOSS
OF HEATING WILL BE A FACTOR IN SUSTAINING ANYTHING INTO OUR AREA.
HOWEVER UPPER FLOW UPPER FLOW IS SWIFT AND CYCLONIC FROM THE
NORTHWEST WITH RUC SHOWING A 15 UNIT VORT MAX/JET STREAK IN
CENTRAL MN. BUT AGAIN AIRMASS IS SO VERY DRY AND ONLY SLIGHTLY
UNSTABLE ALOFT...SO WILL GO WITH A DRY FORECAST FOR NOW.
TUESDAY...FORECAST CONFIDENCE MEDIUM
NW UPPER FLOW CONTINUES WITH ONLY WEAK LOBES NOTED. WEAK
FRONTOGENETICAL FORCING NOTED WITHIN THE LAYER WHERE LIMITED
MOISTURE AND BASE OF ELEVATED CAPE RESIDE. REALLY CANNOT
COMPLETELY RULE OUT ISOLATED DEVELOPMENT...SO VERY SMALL CHANCES
SEEM OK. 925 TEMPS 24-26C SO TOASTY TOMORROW WITH AMPLE SUNSHINE.
TUESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM
A WEAK HIGH PRESSURE RIDGE WILL BUILD INTO SRN WI FROM THE NORTH
FOR TUE NT AND WED. HOWEVER CLOUDS WILL INCREASE WED AFTERNOON AS
A SHORTWAVE TROUGH WITHIN NW FLOW ALOFT MOVES TO NRN IA BY 00Z THU
WITH A DEVELOPING WARM FRONT ALONG THE MN/IA BORDER. THE SHORTWAVE
TROUGH WILL THEN PASS INTO IL WED NT WITH A WAVE OF LOW PRESSURE
TO MOVE FROM MN TO ERN IA IN RESPONSE TO A MUCH STRONGER UPPER
TROUGH DIGGING SWD FROM CANADA. THE WAVE OF LOW PRESSURE WILL THEN
LIKELY TRACK ACROSS IL ON THU WITH THE UPPER LOW MOVING SEWD
ACROSS WI. WITH THE ORGANIZED LOW PRESSURE AREA THERE WILL BE
DECENT SFC-850 MB FRONTOGENESIS WITH PWS INCREASING TO 1.3-1.5
INCHES. MODELS DO DIFFER ON TIMING...STRENGTH AND PLACEMENT OF THE
AFOREMENTIONED FEATURES BUT STILL ENOUGH CONFIDENCE FOR HIGH
CHANCE TO LIKELY POPS FOR WED NT AND THU WITH LINGERING POPS THU
NT.
.LONG TERM...
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM
THE UPPER LOW WILL MOVE AWAY FOR FRIDAY WITH NLY WINDS WEAKENING. A
WEAK NW FLOW ALOFT WILL THEN PREVAIL THROUGH THE PERIOD WITH SFC
HIGH PRESSURE AND DRY CONDITIONS OVER THE REGION. TEMPS WILL BE
NEAR NORMAL.
&&
.AVIATION/00Z TAFS/...VFR THROUGH THE FORECAST PERIOD. SOME MID
CLOUDS LATE TONIGHT/TUESDAY MORNING AS SURFACE TROUGH APPROACHES.
WILL LEAVE MENTION OR SHRA/TSRA DUE TO LOW CONFIDENCE OF OCCURRENCE
AND LIKELY ISOLATED AREAL COVERAGE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...GEHRING