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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 211812
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
212 PM EDT TUE MAY 21 2013

.SYNOPSIS...
THE COMBINATION OF HIGH PRESSURE OVER THE ATLANTIC AND SOUTHWEST
SURFACE WINDS WILL CONTINUE TO PULL A WARM AND HUMID AIRMASS INTO
THE REGION THROUGH THURSDAY. A COLD FRONT WILL PASS THROUGH THE
MID ATLANTIC STATES THURSDAY NIGHT. SURFACE HIGH PRESSURE RETURNS
TO THE AREA FRIDAY INTO THE WEEKEND WITH DRIER CONDITIONS AND
COOLER TEMPERATURES EXPECTED.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE IS PLENTY OF LOW LEVEL MOISTURE(PWATS ~1.5 IN) AND MODERATE
CAPE VALUES(~1100 J/KG)...SO GENERALLY HAVE 30 TO 40 PERCENT POPS
ON TODAY DURING THE AFTERNOON AND EARLY EVENING HOURS...DECREASING
FOR THE LATE NIGHT AND MORNING HOURS.

TEMPERATURE WILL MAX OUT NEAR 80 ALONG THE COAST TO THE MID 80S
INLAND. HIGH TEMPS MAY END UP BEING A FEW DEGREES COOLER IF CLOUD
AND PRECIPITATION REGIONS ARE MORE EXPANSIVE THAN ANTICIPATED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
ON WEDNESDAY...THERE WILL BE LESS COVERAGE OF PRECIPITATION AS
UPPER LEVEL SUPPORT WEAKENS. GUIDANCE ON WEDNESDAY IS STILL
UNCLEAR AS TO WHERE TO FOCUS PRECIPITATION AND KEPT 30 PERCENT
POPS AREA WIDE THAT AFTERNOON AND EARLY EVENING.

ON THURSDAY...UPPER LEVEL DYNAMICS INCREASE AS THE COLD FRONT OVER
THE PLAINS STATES APPROACHES THE AREA. HAVE 40-50 PERCENT POPS FOR
SHOWERS AND THUNDERSTORMS EXCEPT 30 PERCENT IN THE FAR SOUTHEAST.

NAM HAS LOWERED MAX TEMPERATURES SIGNIFICANTLY DURING THIS PERIOD
AND IS CLOSE TO EURO. LOWERED READINGS A FEW DEGREES FROM THE
PREVIOUS FORECAST WITH HIGHS LOW TO MID 80S TUESDAY...MID TO UPR 80S
WEDNESDAY AND AROUND 80 ON THURSDAY. READINGS WILL BE A BIT COOLER
NEAR THE COAST. LOWS WILL BE GENERALLY IN THE MID TO UPR 60S.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
LONG RANGE MODELS CONTINUE TO PUSH COLD FRONT ACROSS THE RGN THU
NITE AND OFFSHORE FRI AM. WILL KEEP THE CHC POPS WITH THIS
FEATURE. LINGERING MSTR NOW PROGGED TO SHIFT OFFSHORE WITH THE
BNDRY FRI SO WILL ONLY CARRY CHC POPS ALONG THE COAST FRI MORN.
LOWS THU NITE IN THE 60S.

CANADIAN HIGH PRES BUILDS INTO THE AREA FROM THE NW FRI AFTN THRU
THE REST OF THE HOLIDAY WEEKEND. UPSHOT WILL BE A DRY PRD WITH
TMPS A FEW DEGREES BLO NRML.

STILL WRM FRI WITH HIGHS IN THE U70S-L80S. CAA KICKS IN FRI NITE.
LOWS THRU WEEKEND IN THE 50S. HIGHS EACH DAY L-M70S...WRMG INTO THE
M-U70S MON.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
SW WINDS WILL PREVAIL DURING THE TAF PERIOD. WIDELY SCT CONVECTION
WILL BE PSBL OVER SE PORTIONS THROUGH EARLY EVENING. INCLUDED TEMPO
GROUP FOR TSTMS AT ECG THROUGH 20Z. ALL OF THE SITES WERE VARYING
BETWEEN VFR AND MVFR AND THIS WILL BE THE TREND FOR AT LEAST THE
FIRST FEW HOURS OF THE TAF PERIOD AND LIKELY AGAIN LATE WEDNESDAY
MORNING. IFR STRATUS IS INDICATED BY MOS AND NAM BUFR SOUNDINGS AT
MOST OF THE TAF SITES FOR WEDNESDAY MORNING ROUGHLY FROM 08 TO 14Z.
CONDITIONS WILL SLOWLY IMPROVE WEDNESDAY MORNING.

OUTLOOK: ISOLATED TO WIDELY SCATTERED CONVECTION WILL BE PSBL LATE
WEDNESDAY AFTN AND EVENING. IFR STRATUS WILL BE PSBL AGAIN THURSDAY
MORNING. MORE WIDESPREAD CONVECTION IS EXPECTED THURSDAY AFTN AND
EVENING AS A COLD FRONT APPROACHES. THE WEATHER IMPROVES FRIDAY AND
BEYOND FOLLOWING THE COLD FRONTAL PASSAGE.
-- End Changed Discussion --

&&

.MARINE...
NO FLAGS EXPECTED TODAY THRU WED...AS SSW FLO (AOB 15-20 KTS WITH
SEAS 2-4 FT) CONTINUES ARND HI PRES OFF THE CST. PRES GRADIENT
WILL INCREASE A BIT LATE WED THRU THU AHEAD OF APPROACHING COLD FRNT
PROGGED TO CROSS THE AREA THU NGT THRU FRI MORNG. ANY SCA CONDITIONS
THAT DEVELOP WILL BE MARGINAL AHEAD OF THE FRNT. WNA CONTINUES TO
FCST SEAS ARND 5 FT OUT NEAR 20 NM STARTING LATE WED...BUT WILL
HOLD OFF ON ANY HEADLINE FOR NOW. WINDS WILL SHIFT TO THE NW OR N FRI
AFTN BEHIND THE FRNT.

&&

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

&&

$$
SYNOPSIS...BMD
NEAR TERM...BMD/MAS/DAP
SHORT TERM...LSA
LONG TERM...MPR
AVIATION...LSA
MARINE...TMG