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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 300123
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
923 PM EDT TUE JUL 29 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO AND OVER THE AREA FROM THE NORTHWEST
THROUGH WEDNESDAY...THEN SLIDE OFF THE COAST ON THURSDAY. A
FRONTAL BOUNDARY WILL DEVELOP ALONG THE COAST BY FRIDAY INTO THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST WATER VAPOR IMAGERY AND 30/00Z RAOB UPPER AIR PLOTS PLACE
-3 STD DEV MID-LEVEL LONGWAVE TROUGH OVER THE ERN CONUS...WITH THE
TROUGH AXIS ALIGNED N-S OVER THE CNTRL APPALACHIANS. REMNANT MID-
LEVEL MOISTURE HAS COMBINED WITH FORCING FOR ASCENT FROM THE
STRONG UPPER TROUGH AND STEEP LOW/MID LEVEL LAPSE RATES FOR A FEW
LIGHT SHOWERS OVER THE ERN VA PIEDMONT THIS EVENING. CAPE
CONTINUES TO BE OVERDONE IN CONVECTIVE MODELS...SO SHOWER ACTIVITY
IS NOT BEING HANDLED WELL. EXPECT CURRENT TRENDS TO DIMINISH...BUT
CANNOT RULE OUT A STRAY SHOWER OR TWO OVERNIGHT FROM THE PIEDMONT
INTO CNTRL VA. HOWEVER...COVERAGE AND CONFIDENCE IS NOT HIGH ENOUGH
TO GO MORE THAN 10% POPS. DRY LOW-LEVELS WILL ALSO MAKE IT VERY
DIFFICULT TO GET MEASURABLE PRECIP. EXPECT GENERALLY PARTLY CLOUDY
SKIES OVERNIGHT FROM THE PIEDMONT INTO CNTRL VA AS BUFR SOUNDINGS
INDICATE THAT THE MID CLOUD DECK WILL STICK AROUND. TEMP FORECAST
REMAINS ON TRACK WITH LOWS GENERALLY IN THE MID 50S TO LOW
60S...NEARLY 10 DEGS BELOW NORMAL. RICHMOND RECORD LOW FOR JULY 30
IS 58 DEGS AND THE CURRENT FORECAST IS 61.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
A TROUGH ALOFT LINGERS OVER THE EASTERN CONUS THROUGH WEDNESDAY...
BEFORE WEAKENING/SHIFTING FARTHER WEST BY THURSDAY/FRIDAY. WEDNESDAY
WILL HAVE CONTINUED SUBSIDENCE KEEPING DRY CONDITIONS IN PLACE
WITH A SLIGHT WARMING TREND BUT STILL IN THE LOW/MID 80S FOR
HIGHS. LOWS WED NIGHT IN THE UPPER 50S TO MID 60S. WEAK SFC HIGH
PRESSURE WILL BE OFF THE COAST FOR THURS...WITH SSE LOW LVL FLOW
ACROSS THE AREA. ONLY A VERY SLIGHT INCREASE IN HUMIDITY IS
EXPECTED...OTHERWISE PARTLY TO MOSTLY SUNNY WITH HIGH TEMPS IN THE
MID TO UPR 80S. BY FRIDAY...BERMUDA HIGH PRESSURE BEGINS TO
REBOUND ACROSS THE WESTERN ATLANTIC WITH A FRONTAL BOUNDARY
DEVELOPING ALONG THE VA/NC COAST. THIS FEATURE WILL BE THE FOCUS
FOR INCREASED TSTM CHANCES LOCALLY (ESPECIALLY AFTN)...AND THUS
WILL CARRY SOLID CHC POPS (30-40%). WITH PLENTY OF CLOUDS AROUND
AND PCPN POSSIBLE...MAX TEMPS FRIDAY WILL LIKELY BE A TOUCH COOLER
THAN THURSDAY. HIGHS IN THE LOW/MID 80S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
FORECAST RATIONALE REMAINS LARGELY THE SAME FOR MEDIUM RANGE PERIOD.
PERSISTENT UPPER LEVEL TROUGH OVER THE EASTERN THIRD OF THE CONUS
WILL RETROGRADE BACK WEST INTO THE MS VLY AHEAD OF THE BUILDING
WESTERN ATLANTIC RIDGE. THIS WILL ALLOW FOR PW VALUES/DEEP LYR
MOISTURE RAMPING UP THROUGH THE PERIOD. THUS, SCT SHRAS EXPECTED
THROUGH THE PERIOD AHEAD OF THE ADVANCING COASTAL FRONT/INVERTED
TROUGH, WHICH WILL LOCATE ALONG/JUST OFF THE MID-ATLANTIC/SOUTHEAST
COAST SATURDAY, EVENTUALLY MOVING INLAND ACROSS THE COASTAL PLAIN BY
MONDAY. GIVEN THAT THERE IS NO SIGNIFICANT FORCING MECHANISM TO KEY
IN ON, WILL LEAN TOWARDS CLIMATOLOGY AND USE DIURNALLY DRIVEN POPS
THROUGH THE SAT-TUE TIME PERIOD. FOR TEMPS, LOOK FOR HIGHS TO REMAIN
AT OR BELOW CLIMO NORMAL...GENERALLY RANGING INTO THE L-M 80S
SUNDAY/MONDAY...85 TO 90 ON TUESDAY AHEAD OF AN APPROACHING COLD
FRONT. EARLY MORNING LOWS IN THE 60S SUN MORNING, INCREMENTALLY
INCREASING TO U60S TO AROUND 70 BY EARLY MONDAY/TUESDAY.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
GENERALLY CLEARING SKIES ACROSS THE AKQ FORECAST AREA. WEAK AREA OF
HIGH PRESSURE WILL SLIDE OVER THE AREA OVERNIGHT. MID LEVEL WAVE
PASSING THROUGH THE MID-ATLANTIC MAY BE STRONG ENOUGH TO HELP
INITIATE SOME VERY ISOLATED SHOWERS ACROSS THE AREA. EXPECT WINDS TO
VEER TO THE S/SE WED AFTERNOON WITH A SCT CU FIELD DEVELOPING.

OUTLOOK...DRY WEATHER IS FORECAST THROUGH THURSDAY. THERE WILL BE A
A CHANCE FOR MAINLY AFTN/EVENING TSTMS FRIDAY. VFR IS EXPECTED
OUTSIDE OF PCPN THROUGH FRIDAY.

NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.

&&

.MARINE...
LATEST OBS REFLECT N-NE WINDS ACROSS THE WATERS THIS AFTN, WITH
SLACKENING PRESSURE GRADIENT OVER THE REGION AS HIGH PRESSURE BUILDS
IN FROM THE OHIO VLY. LIGHT WINDS CONTINUE ~10 KT LATE THIS AFTN AND
TONIGHT. SEAS 2-3FT, WAVES 1-2 FT. WINDS REMAIN AOB 10 KT WED/ WED
NGT AS SFC HI PRESSURE REMAINS OVERHEAD. WINDS VEER AROUND TO THE
E-SE BY THU AS THE HIGH SLIDES OFFSHORE AND LOW PRES PASSES WELL N
OF THE LOCAL AREA. COASTAL FRONT/INVERTED TROUGH APPROACHES FROM THE
EAST BY THE WEEKEND...WITH WINDS VEERING AROUND TO THE S-SW LATE
FRIDAY INTO THE WEEKEND WITH RAIN CHANCES INCREASING AGAIN OVER THE
WATERS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...SAM
SHORT TERM...ALB/JDM
LONG TERM...MAM
AVIATION...DAP
MARINE...MAM