Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Wakefield, VA banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4]



000
FXUS61 KAKQ 020750
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
350 AM EDT WED SEP 2 2015

.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL PERSIST OVER THE MID ATLANTIC
THROUGH THURSDAY WITH WEAK HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. STRONGER HIGH PRESSURE THEN SLOWLY DROPS DOWN FROM THE
NORTHEAST STATES FRIDAY INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST GOES WATER VAPOR IMAGERY CENTERS SUBTROPICAL HIGH PRESSURE 
OFF THE SOUTHEAST COAST...WITH THE RIDGE AXIS EXTENDING NWD ALONG 
THE ERN SEABOARD. AT THE SFC...HIGH PRESSURE REMAINS CENTERED OVER 
THE OH VALLEY. DEWPOINTS HAVE CLIMBED BACK INTO THE LOW 
70S...RESULTING IN MILD TEMPS IN THE UPPER 60S TO LOW 70S EARLY THIS 
MORNING. PATCHY GROUND FOG LIMITED TO MAINLY SE VA/NE NC AND THE MD 
ERN SHORE...AND WILL QUICKLY BURN OFF AFTER SUNRISE. 

FOR TODAY...A COMPACT UPPER LOW OVER THE OH VALLEY WILL OPEN AND 
DROP SEWD TOWARD THE MID-ATLANTIC REGION. SHORTWAVE ENERGY AND 
UPSLOPE FLOW WILL PRODUCE SHOWERS/THUNDERSTORMS OVER THE CENTRAL 
APPALACHIANS THIS AFTERNOON. LOWER RES MODELS PUSH THIS CONVECTION 
EWD INTO THE PIEDMONT AND CENTRAL VA LATE THIS AFTERNOON AND EARLY 
EVENING...BUT HI RES GUIDANCE LIMITS ANY PRECIP TO THE PIEDMONT. A 
WARM/MOIST AND MARGINALLY UNSTABLE AIR MASS WILL BE IN PLACE OVER 
THE LOCAL AREA...BUT DOWNSLOPE WINDS...LIMITED MOISTURE AND WEAK 
FLOW/SHEAR WILL LIMIT CONVECTION POTENTIAL. HAVE CAPPED AT LOW END 
CHANCE POPS. SLIGHT INCREASE IN LOW LEVEL THICKNESSES AND H85 TEMPS 
+16 TO 18 (+1 STD DEV) WILL RESULT IN A DEG OR TWO OF WARMING TODAY 
COMPARED TO 24 HOURS AGO. HIGHS FORECAST IN THE LOW 90S...EXCEPT 
UPPER 80S ALONG THE COAST. 

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ANOMALOUS UPPER RIDGE BUILDS EWD DURING THE SHORT TERM 
PERIOD...RESULTING IN GENERALLY WEAK NWLY FLOW ALOFT. AN UPPER 
TROUGH DROPS OVER THE CANADIAN MARITIMES THURS...PUSHING AN 
ASSOCIATED SFC LOW OFF THE ERN CANADIAN COST. A WEAK SFC TROUGH WILL 
EXTEND SWD OVER ERN VA. SHORTWAVE ENERGY CONTINUES TO DROP OVER THE 
SRN LOCAL AREA THURS AFTERNOON...RESULTING IN SUBTLE FORCING FOR 
ASCENT ALONG THE SFC TROUGH. WARM/MOIST AIR MASS REMAINS IN PLACE. 
WEAK FLOW UNDER THE RIDGE PRODUCES LITTLE SHEAR...SO 
ORGANIZED/WIDESPREAD CONVECTION IS NOT EXPECTED. WILL RETAIN SLIGHT 
CHANCE TO LOW END CHANCE POPS...FOCUSED ALONG THE SFC TROUGH IN THE 
SE. H85 TEMPS OF +16 TO 18C (+1 STD DEV) WILL AGAIN RESULT IN TEMPS 
IN THE LOW 90S. MILD THURS MORNING WITH LOWS IN THE UPPER 60S TO 
LOW 70S.  

LARGE SCALE CONFLUENCE ACROSS SERN CANADA IN WAKE OF THE DEPARTING 
UPPER TROUGH WILL ALLOW STRONG SFC HIGH PRESSURE TO BUILD SEWD INTO 
NEW ENGLAND FRIDAY. THIS WILL PUSH A BACKDOOR FRONT INTO THE REGION. 
WEAK PERTURBATIONS IN NWLY FLOW MAY BE ENOUGH TO PROVIDE SUBTLE 
FORCING...BUT MOISTURE REMAINS LIMITED WITH NEAR NORMAL PWATS AND 60-
70 PCT 1000-500MB MEAN RH. WILL MAINTAIN LOW END CHANCE POPS. HIGH 
PRESSURE RIDGING INTO THE REGION WILL RESULT IN NELY/ONSHORE FLOW 
AND COOLER TEMPS COMPARED TO THURS. HIGHS FORECAST IN THE MID TO 
UPPER 80S. 

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
GOING WITH A BLEND OF THE 12Z GFS/12Z ECMWF FOR THE EXTENDED PERIOD. 
INITIALLY...20-30% POP FOR A SHOWER AND MAYBE A TSTM FRI NGT THRU 
SAT AFTN...AS WEAK BACKDOOR FRONT DROPS THRU THE AREA...AS HI PRES 
BLDS FM ERN CANADA SWRD TO ALNG THE NEW ENGLAND CST. THEN...WILL 
HAVE DRY WX FM SAT NGT THRU TUE...AS THE CNTR OF HI PRES BLDS DOWN 
OVR THE MID ATLC REGION AND JUST OFFSHR. HIGHS WILL BE 80 TO 85 SAT 
AND SUN...GENERALLY IN THE MID 80S MON...AND IN THE MID TO UPR 80S 
TUE. LOWS WILL BE IN THE MID 60S TO LWR 70S SAT MORNG...IN THE 60S 
SUN AND MON MORNGS...AND IN THE MID 60S TO NEAR 70 TUE MORNG.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
FCST PRBLM IN THE SHORT TERM WILL BE FOG DVLPMNT BEFORE SR GIVEN
THE CALM WNDS AND NEARLY SATURATED AIRMASS. ECG ALREADY DOWN TO
1/2SM OR LESS WITH SBY BOUNCING BACK AND FORTH IN THE MVFR RANGE.
LTST DATA CONTS TOWARD FOG RTHR THAN STRATUS SO HAVE LEANED THAT
WAY WITH THE 06Z FCSTS. XPCT THAT ECG WILL STAY LIFR GIVEN THE
ASOS LOCATION TO THE WATER. SBY WILL PRBLY CONT TO BOUNCE UP AND
DOWN GIVEN THE FACT THAT IT RAINED THERE YSTRDY. WENT WITH A TEMPO
GROUP AT RIC/PHF CLOSER TO SR BUT KEPT FOG OUT OF ORF ATTM.

THE FOG BURNS OFF BY OR SHORTLY AFTR 12Z WITH VFR CNDTNS. XPCT
ANTHR DAY OF SEA BREEZE DVLPMNT SO ADDED ANTHR LINE TO THE CSTL
TAFS SITES FOR THIS AFTR 16Z. NEXT CONCERN IS FOR ISLTD CONVECTION
DVLPNG ALONG THE SEA BREEZE BNDRY MUCH LIKE YSTRDY ALONG WITH SCT
CONVECTION THAT DVLPS OVR THE MTS THEN DRIFTS EASTWRD DRNG THE
LATE AFTRN/ERLY EVE. KEPT PCPN OUT OF FCST ATTM GIVEN LOW CONFIDENCE
OF WHERE AND WHEN ANY CONVECTION DVLPS.

OUTLOOK...DRY WEATHER IS EXPECTED THROUGH SUNDAY. SCT DIURNAL
CONVECTION PSBL THU/FRI. ALSO LOOK FOR SOME STRATUS AND FOG AT
SOME OF THE TAF SITES WITHIN A FEW HOURS OF SUNRISE.

&&

.MARINE...
NO HEADLINES IN SHORT TERM. WNDS REMAIN AOB 10 KTS ALONG WITH SEAS 
AOB 2 FT THRU THU NIGHT AS HIGH PRS DOMINATES. XPCT ONSHORE SEA 
BREEZES BOTH THIS AFTRN AND THU AFTRN WITH WNDS BCMG MORE WSW AT 
NIGHT. 
 
DATA SUGGESTS HIGH PRS TO THE N WILL BE STRONG ENUF TO PUSH A BKDR 
CDFRNT S ACROSS THE WTRS FRI. THE HIGH WILL BE SLOW TO MOVE OFF THE 
NEW ENGLAND COAST THIS WKEND. THIS SCENARIO RESULTS IN A XTNDD PRD 
OF NE FLOW. DATA EVEN SUGGESTS SOLID SCA CNDTNS DVLPNG N-S FRI NIGHT 
AND CONTG SAT AS WNDS INCRS TO BTWN 15-25 KTS ALONG WITH BLDG SEAS 
TO BTWN 4-6 FT. 

IN ADDITION...THE ONSHORE FLOW WILL LIKELY RESULT IN NEARSHORE WAVES 
OF 3-4 FT WHICH WILL INCRG THE RIP CURRENT THREAT FOR THE UPCOMING 
HOLIDAY WKEND. DESPITE BEING OUT 3 DAYS...TIDAL GUID SUGGESTS TIDES 
BUILDING TO BTWN 1/2 TO 1 FOOT ABOVE NRML BY SAT...BUT REMAINING BLO 
MINOR FLOODING THRESHOLDS.

&&

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

&&

$$
SYNOPSIS...MAS
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...
AVIATION...MPR/LSA
MARINE...MPR



National Weather Service
Disclaimer Privacy Policy