Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 211745
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
145 PM EDT THU AUG 21 2014

.SYNOPSIS...
A FRONTAL BOUNDARY REMAINS NEARLY STATIONARY ACROSS THE AREA INTO
THE UPCOMING WEEKEND. HIGH PRESSURE FROM NEW ENGLAND IS SLOW TO
BUILD OVER THE REGION FROM SUNDAY INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WARM FRONT HAS STALLED OVR THE FA...AND WILL RMN NRLY STATIONARY
TDA. EXPECT VRB CLDS TO PCLDY AGN TDA AS MORNING FOG/STRATUS
DISSIPATES. MOST OF THE DAY XPCD TO BE PCPN FREE.
HEATING...MODEST DEWPTS (FOR MID AUG) AND CONVERGENCE INVOF
STALLED FRONTAL BNDRY (OVR INTERIOR PORTIONS OF FA) XPCD TO RESULT
IN ISOLD TO PSBLY SCT CONVECTION BY LT THIS AFTN/EVE. WEAKENING
S/W FM THE WNW MAY BRING CONVECTION INTO FAR WNW AREAS LT IN THE
DAY AS WELL. HI TEMPS FM THE M80S AT THE CST...TO THE U80S TO L90S
INLAND.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
NW FLO ALOFT RMNS FM TNGT INTO THE WKND...W/ SERIES OF WK IMPULSES
PASSING THROUGH THE RGN. INITIAL IMPULSE (WKNG S/W) MAY KEEP AT
LEAST ISOLD CONVECTION OVR THE FA TNGT. A 2ND WK S/W PUSHES
THROUGH THE FA ON FRI WILL PTNTL FOR ADDITIONAL ISOLD/SCT
CONVECTION BY AFTN/EVE HRS.

A MORE VIGOROUS WAVE DROPS ACROSS THE REGION FRI NGT INTO SAT AS
SFC BNDRY RMNS OVR THE FA. THIS SHOULD PROVIDE BEST CHC OF AND
GREATEST AREAL COVERAGE OF SHOWERS/TSTMS ACROSS THE LOCAL AREA
DURING THE SHORT-TERM PERIOD DUE TO MORE FAVORABLE/STRONGER UPPER
JET SUPPORT. HIGH PRESSURE BUILD OVER NEW ENGLAND SATURDAY BEGINS
TO PUSH S TOWARD MDATLC RGN BY LT IN THE DAY. THIS WILL PUSH THE
REMNANT FRONT BACK S OF THE AREA.

HI TEMPS FRI MNLY IN THE M/U80S FRI...THEN FM THE L/M80S ON SAT
(PSBLY U70S ALG THE ATLC BEACHES ON THE ERN SHORE). LO TEMPS MNLY
BE IN THE U60S TO L70S FRIDAY AND SATURDAY MORNINGS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
DECREASING CHANCES FOR PRECIP AND NEAR SEASONABLE...LATE SUMMER
TEMPERATURES EXPECTED THRU THE EXTENDED PERIOD FORECAST.

UPPER FLOW CONTINUES TO BE DOMINATED BY BUILDING HIGH PRESSURE OVER
THE CNTRL CONUS AND LOW PRESSURE/TROUGHING OFF THE NE COAST. FLOW
REMAINS BLOCKED OVER ERN CANADA AND THE NERN US...RESULTING IN
LITTLE PROGRESSION OF THE CNTRL CONUS RIDGE THRU THE PERIOD. THE
RESULT WILL BE ONGOING NWLY FLOW INTO THE EARLY PERIOD. BACKDOOR
FRONT WILL PUSH WELL SOUTH OF THE LOCAL AREA SUN AS THE TROUGH
AMPLIFIES ALONG THE ERN SEABOARD. LATEST MODEL GUIDANCE HAS TRENDED
SLIGHTLY WETTER SUN AFTER PREVIOUSLY BRINGING IN DRIER AIR BEHIND
THE FRONT. SFC HIGH PRESSURE OVER THE NE STATES WILL RIDGE SWD OVER
THE LOCAL AREA IN WAKE OF THE FRONT...WITH SUBSIDENCE INDICATED IN
MODEL SOUNDINGS. MOISTURE ALSO LOOKS TO BE ON THE DOWNTREND AS MODEL
DERIVED PWATS DROP BELOW 1.5 INCHES. WITH THAT SAID...SUN MAY END UP
BEING DRY...BUT WILL RETAIN SLIGHT CHANCE POPS OVER THE PIEDMONT AND
COASTAL AREAS AS DISTURBANCES IN NWLY FLOW AND MODEL UNCERTAINTY
DECREASE CONFIDENCE. BETTER CONFIDENCE IN DRY CONDITIONS HEADING
INTO EARLY NEXT WEEK AS THE CNTRL CONUS HIGH BEGINS TO NUDGE IN FROM
THE WEST AND SUBSIDENCE ALOFT WINS OUT. BEST MOISTURE ALSO GETS
SHUNTED TO THE SOUTH AND WEST. TREND CONTINUES INTO TUES AND WEDS AS
HIGH PRESSURE BUILDS OVERHEAD AND DRY AIR AND SUBSIDENCE WIN OUT.

ONSHORE FLOW AND LOW-LEVEL THICKNESSES YIELD DAYTIME TEMPS GENERALLY
IN THE UPPER 70S TO LOWER 80S THRU TUES (-1 STD DEV FOR THIS TIME OF
YEAR). RETURN FLOW ON WEDS AND WARMING THICKNESSES PUSH TEMPS BACK
INTO THE MID 80S. LOWS GENERALLY IN THE LOW-MID 60S THRU THE PERIOD
AS DEWPOINTS REMAIN IN THE LOW-MID 60S.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
A WEAK FRONTAL BOUNDARY IS OVER THE NORTHEAST PART OF THE AREA.
A STRONGER FRONT WILL MOVE INTO THE MID ATLANTIC TONIGHT AND
FRIDAY. THESE FRONTS COMBINED WITH A MOIST AIR MASS WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH FRIDAY.
THUNDERSTORMS ARE EXPECTED TO BE MORE NUMEROUS ON FRIDAY. WITH A
SEA BREEZE AND A WEAK FRONTAL BOUNDARY OVER THE EASTERN PART OF
THE AREA THIS AFTERNOON WILL HAVE SCATTERED THUNDERSTORMS DEVELOP.
VERY DIFFICULT TO TIME THESE BUT THESE SHOULD END BY AROUND 00Z.
OUT TO THE WEST SEVERAL MESOSCALE CONVECTIVE SYSTEMS ARE MOVING
TOWARD THE AREA. THESE SHOUDL DIMINISH AS THEY CROSS THE MOUNTAIN
BUT COULD STILL TRIGGER A SHOWER OR THUNDERSTORM NEAR KRIC THIS
EVENING. THE THUNDERSTORMS TO THE WEST WILL PRODUCE PLENTY OF MID
LEVEL CLOUDS ACROSS THE AREA TONIGHT. THIS SHOULD PREVENT ANY WIDE
SPREAD FOG FROM FORMING. THE BEST CHANCE FOR THUNDERSTORMS WILL
DEVELOP FRIDAY AFTERNOON AND EVENING ACROSS ALL TAF SITES. EXPECT
CLEARING WEATHER FOR THE WEEKEND WITH VFR CONDITIONS RETURNING.
WINDS WILL BE VERY LIGHT THROUGH FRIDAY WITH MAINLY SOME EAST
WINDS NEAR THE COAST AND SOUTHWEST INLAND. ALL AREAS WILL SWITCH
TO NORTH OR NORTHEAST BY SATURDAY.

&&

.MARINE...
NO HEADLINES NEC WITH THIS FORECAST PACKAGE. A STATIONARY FRNT WILL
REMAIN JUST INLAND TDA OVR THE MID ATLANTIC REGION. THIS WILL LEAD
TO LGT WINDS OVR ALL WTRS (AOB 10 KT) OUT OF THE S/SE. EXPECT MAINLY
2 FT SEAS (3 FT THIS MORNG OUT 20NM). THE FRNT STALLS OVR THE WTRS
TNGT AS A WAVE OF LO PRES DEVELOPS ALONG THE FRNT...VEERING WINDS
BEHIND THE LO TO AVG OUT OF THE N ON FRI. HI PRES OVR THE NE STATES
RIDGES SWD OVR THE WTRS FRI NGT INTO SAT AS LO PRES PUSHES OFF THE
NC COAST. A STRENGTHENING PRES GRADIENT WILL RESULT IN INCREASING
NELY WINDS OVER THE CSTAL WTRS LATE FRI NGT THRU SAT. HI PRES
REMAINS ANCHORED OFF THE NE CST THRU ERLY NEXT WEEK RESULTING IN
PERSISTENT ONSHORE FLOW. ATTM...SPEEDS APPEAR TO REMAIN
SUB-SCA...BUT SEAS ARE FORECAST TO BLD TO 4-5 FT LATE SAT THRU
MON.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
     MDZ025.
NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
     NCZ102.
VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
     VAZ098>100.
MARINE...NONE.

&&

$$
SYNOPSIS...AJZ/ALB
NEAR TERM...AJZ/ALB
SHORT TERM...AJZ/ALB
LONG TERM...SAM
AVIATION...MAS/JAB
MARINE...MAS






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