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Area Forecast Discussion
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000
FXUS61 KAKQ 040233
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1033 PM EDT THU SEP 3 2015

.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL PERSIST OVER THE LOCAL AREA 
OVERNIGHT WITH HIGH PRESSURE CENTERED OVER THE OHIO VALLEY. STRONGER
HIGH PRESSURE THEN SLOWLY DROPS DOWN FROM THE NORTHEAST STATES
FRIDAY AFTERNOON THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WEAK SFC TROUGH PERSISTS ACRS THE REGION THIS EVENING...WITH LIGHT
NW FLOW ALOFT. AIRMASS REMAINS SLIGHTLY UNSTABLE AS OF 02Z...EVIDENCED
BY SOME MODEST ML CAPES PER SPC MESOANALYSIS AND ISOLATED/WIDELY
SCATTERED TSTMS CONTINUING OVER NORTHERN VA AND PORTIONS OF THE
PIEDMONT. HAVE EXTENDED 20-30% POPS OVER THE FAR NORTH AND IN THE
PIEDMONT THROUGH 1 AM. OTHERWISE...WARM/HUMID UNDER VARIABLY
CLOUDY SKIES WITH TEMPS MAINLY IN THE 70S. OVERNIGHT LOWS WILL
RANGE FROM THE UPPER 60S IN RURAL AREAS OF INTERIOR VA/MD TO THE
LWR 70S ELSEWHERE. PATCHY FOG DEVELOPING IN SOME AREAS...THOUGH
WITH DEW PTS THIS HIGH RARELY SEE DENSE FOG DEVELOPMENT AND
EXPECT MOST AREAS TO MAINTAIN VSBY OF 2SM OR GREATER OVERNIGHT.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
ANOMALOUS UPPER RIDGE BUILDS OVER THE NE CONUS DURING THE SHORT
TERM. A WEAKNESS UNDER THE RIDGE LOCATES OVER THE -SE
STATES...RESULTING IN WEAK FLOW ALOFT. LARGE SCALE CONFLUENCE OVER
ERN CANADA AND NEW ENGLAND WILL ALLOW STRONG SFC HIGH PRESSURE TO
BUILD SWD INTO NEW ENGLAND...PUSHING A BACKDOOR FRONT INTO THE RGN
FRI MRNG-AFTN. SFC WNDS TURN TO THE NE FRI...RESULTING IN THE
BEGINNINGS OF A COOL DOWN. A WARM/MOIST AND MODERATELY UNSTABLE
AIR MASS (SREF MLCAPE VALUES 1000-1500 J/KG) WILL REMAIN OVVR THE
FA IN ADVANCE OF THE FRONT. MORE STABLE ALONG THE COAST DUE TO
ONSHORE FLOW. HAVE MAINTAINED SLGT CHC TO CHC POPS E AND
CNTRL...BUT HAVE CONTD W/ SOLID CHANCE (40-50%) OVR THE PIEDMONT
AS WEAK S/W DROPS OVR THE RGN. VRB CLDS- PARTLY CLOUDY CONDS W/ HI
TEMPS FM THE M-U80S INVOF ERN SHORE/ALG THE CST TO THE U80S-ARND
90F INLAND.

THE WX FM FRI NGT THROUGH SUN LOOKING MORE UNSETTLED THAN BEFORE.
PDS OF LO LVL CLDS XPCD INTO SUN W/ CONTD ENE WNDS. GUSTS UP TO
25 MPH NR THE CST LT FRI NGT. MDLS TDA ARE LESS EMPHATIC ABT DRIER
AIR MASS PUSHING SSW INTO/ACRS THE FA THIS WKND. COMBO HI PRES TO
THE NNE AND LO PRES OVR SE CONUS TO KEEP MOIST ONSHORE WNDS AND
LIKELIHOOD OF WK IMPULSES TRACKING ACRS THE FA FM THE E. WILL HAVE
20-40% POPS SAT-SUN...HIGHEST IN SE VA/NE NC. CONTD BREEZY (GUSTS
TO 25-30 MPH NR THE CST IN ERN VA/NE NC) ON SAT...LESS WND XPCD
SUN. HI TEMPS SAT FM THE M-U70S NR THE CST TO ARND 80F INLAND. LO
TEMPS SAT NGT FM THE M60S TO ARND 70F. HI TEMPS SUN FM THE U70S TO
L80S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LONG TERM PERIOD STARTS OFF SUN NGT AND MON WITH SFC LO PRES
SPINNING OFF THE CAROLINA CST WITH HI PRES N AND W OF THE FA.
RESULTANT ONSHORE FLOW WILL LEAD TO TEMPS ONLY MAKING IT INTO THE
MID 80S MON UNDER A PRTLY-MSTLY SKY. WITH THE MOIST ONSHORE FLOW
DID HOLD ONTO SOME SLGT CHANCE-CHANCE POPS OVER MUCH OF THE FA
SUN NGT/MON. KEPT THUNDER OUT DUE TO A LACK OF INSTABILITY. THE
SFC LO WEAKENS AND STARTS SLIDING E TUE ALLOWING FOR DRIER CONDS
AND TEMPS REBOUNDING INTO THE MID/UPR 80S UNDER A PRTLY CLOUDY
SKY. DRY WX CONTINUES MIDWEEK WITH TEMPS FURTHER INCREASING AS SLY
FLOW DEVELOPS AHEAD OF THE NEXT COLD FRNT...WITH HI TEMPS IN THE
UPR 80S TO NR 90 WED AND THUR. THE FRNT WILL CROSS THE AREA
SOMETIME LATE THU OR FRI.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SOME WIDELY SCATTERED CONVECTION STILL REMAINING ACROSS THE
REGION WHICH SHOULD GENERALLY DISSIPATE DURING THE OVERNIGHT. NO
TAF SITES ARE AT RISK FOR ANY ACTIVITY. EXPECT SOME AREAS OF MVFR
FOG/HAZE TO AGAIN DEVELOP OVERNIGHT WITH THE CHC FOR PTCHY IFR
CONDS. SCATTERED DIURNAL CONVECTION POSSIBLE AGAIN FRIDAY ALONG
BACKDOOR COLDFRONT PASSAGE.

DRY WEATHER AND VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA HEADLINES HAVE BEEN ISSUED WITH THIS FORECAST PACKAGE FOR THE
OCEAN/BAY/LWR JAMES. FOR TNGT...WEAK TROF OF LO PRES OVER THE WTRS
WILL LEAD TO VRB WINDS UNDER 10 KT. NE FLOW THEN DEVELOPS FRI AS A
BACKDOOR COLD FRNT DROPS TWRDS THE REGION AND HI PRES OVERSPREADS
THE NE STATES. WINDS WILL SLOWLY INCREASE THRU THE DAY OVER ALL
WTRS...TO 15-20 KT OVER THE BAY/OCEAN BY THE EVENG HRS AND LWR
JAMES BY ERLY OVRNGT. AT THE SAME TIME...WAVES OVER THE LWR BAY
WILL INCREASE TO 4 FT WITH SEAS OVER CSTL WTRS UP TO 6 FT. THE SCA
WILL RUN THRU THE END OF THE 4TH PERIOD FOR NOW (SAT AFTN) BUT
MAY HAVE TO BE EXTENDED FURTHER OUT IN TIME ESPECIALLY OVER CSTL
WTRS WITH SEAS AOA 5 FT LIKELY CONTINUING INTO SAT NGT/SUN. IN
ADDITION...THE ONSHORE FLOW AND HI WAVES WILL ENHANCE THE RIP
CURRENT THREAT FOR THE HOLIDAY WKEND. GUID CONTS TO BUILD TIDES
TO 1 FOOT ABOVE NRML BY SAT...CLOSE TO MINOR FLOODING THRESHOLDS
IN SOME LOCATIONS.

WINDS/WAVES/SEAS DECREASE INTO ERLY NEXT WEEK AS THE SFC HI
WEAKENS AND FLOW BCMS MORE OUT OF THE E THAN NE. WINDS THEN TURN
TO THE S MIDWEEK AHEAD OF THE NEXT COLD FRNT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM FRIDAY TO 7 PM EDT SATURDAY FOR 
     ANZ630>632-634-650-652-654-656-658.
     SMALL CRAFT ADVISORY FROM 10 PM FRIDAY TO 7 PM EDT SATURDAY 
     FOR ANZ638.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...ALB/SAM
LONG TERM...MAS
AVIATION...DAP/JEF
MARINE...MAS



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