FXUS61 KAKQ 070148
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
848 PM EST SUN DEC 6 2009
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TONIGHT. A WEAKENING COLD FRONT MOVES
ACROSS THE AREA MONDAY EVENING. HIGH PRESSURE RETURNS MONDAY NIGHT
AND TUESDAY. LOW PRESSURE TRACKS NORTHEAST ALONG THE ATLANTIC SEABOARD
WEDNESDAY. HIGH PRESSURE BUILDS ACROSS THE AREA THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CRNT FCST ON TRACK WITH ONLY MINOR CHANGES MADE TO GRIDS THIS EVE.
SFC HIGH OVRHD ATTM CONTS TO SLIDE OFFSHORE OVRNITE. SAT LOOP SHWNG
WDSPRD HIGH/MID LVL CLDNS ACROSS THE FA. SINCE THESE CLDS ARE AOA
12K FT...WILL KEEP WORDING IN ZFP AS PT CLDY. DESPITE THE CLDNS...
TMPS HAVE ALRDY DROPPED INTO THE 30S SINCE SS. TMPS XPCTD TO DROP
TO NR CRNT DP TMPS. LOWS IN THE 20S...XCPT L30S SERN CNTYS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...
CLOUDS INCREASE THROUGH THE MORNING AHEAD OF INCREASING
ISENTROPIC MOISTURE ALONG THE 285-295K SFC. BRIEF WINDOW OF
RELATIVELY DEEPER OVERRUNNING MSTR WITH THE QUICK
MOVING...DAMPENING UPR SHORTWAVE AND DECAYING SFC COLD
FRONT/COASTAL TROF. FLATTENING VORT LOBE TO REMAIN N OF THE
AREA...MEANING THAT ANY OPPORTUNITY FOR SUFFICIENTLY DEEP MSTR
(FOR POPS) WILL BE SHORT-LIVED (MAINLY LT MORNING THROUGH THE
EARLY EVENING HOURS). GFS HAS TRENDED TOWARDS MORE AGGRESSIVE
NAM/SREF SOLUTION...SO HV DECIDED TO MAINTAIN SLIGHT CHC/LOW CHC
POPS (20-30% TOPS) FOR LIGHT RAIN OVER SERN VA/NERN NC WHERE SE
BOUNDARY LAYER FLOW AHEAD OF THE TROUGH (ORIGINATING OVER THE GULF
STREAM) WOULD LEAD TO MORE FAVORABLE 850-700 MB MOIST ISENTROPIC
ASCENT. WENT WITH LIGHT RAIN WORDING...WITH QPF LIKELY ON THE
ORDER OF A FEW HUNDREDTHS OR LESS. EVEN WITH CLOUD COVER...WAA
SHOULD MAKE FOR A MODESTLY WARMER DAY TOMORROW. HIGHS L/M 40S NW
TO L/M 50S SE.
TUESDAY...
HIGH PRESSURE OVER THE CAROLINAS BUILDS BACK OVER THE REGION FOR
TUESDAY AND SHOULD PROVIDE A DRY START TO THE DAY. BY
MIDDAY...ISENTROPIC LIFT AHEAD OF AFOREMENTIONED LOW PRESSURE
CURRENTLY OVER THE GREAT PLAINS WILL SPREAD INCREASING CLOUDS AND
THE CHC OF SHOWERS OVER THE WESTERN TIER OF THE CWA AS EARLY AS
TUESDAY AFTN. TRENDED UP TO LKLY/CATEGORICAL POPS TUESDAY NIGHT
EARLY WEDNESDAY. POTENTIAL FOR NOCTURNAL CONVECTION DOES EXIST
ACROSS SOUTHERN TIER OF COUNTIES BEHIND THE WARM FRONT AND AHEAD
OF COLD FRONTAL PASSAGE LTR TUESDAY NIGHT/EARLY WED MORNING...AS
SOUTHERLY LLJ SHOULD ALLOW FOR INCREASING MOISTURE IN A
DECREASINGLY UNSTABLE ENVIRONMENT IVOF THE WARM FRONT. FOR NOW...HV
DECIDED TO KEEP THUNDER MENTION OUT OF THE FORECAST UNTIL TIMING
BECOMES MORE CERTAIN. WHAT DOES LOOK LIKE A MORE OF A NEAR
CERTAINTY...BESIDES THE RAIN ITSELF...IS A NON-DIURNAL
TEMPERATURE CURVE TUESDAY NIGHT ACROSS THE SOUTHERN HALF OF THE
AREA. HV GONE CLOSE TO MET DEPICTION OF TEMPS TUESDAY NIGHT AND
WEDNESDAY IN ASSN WITH THIS FEATURE. LOOK FOR LOWS IN THE 40S
TUESDAY NIGHT...RISING INTO THE L/M 50S WED MORNING.
WEDNESDAY...
RAIN CLEARS OUT THE FIRST HALF OF THE DAY WEDNESDAY AS LOW
PRESSURE EXITS TO THE NORTHEAST. HV CLEARED THINGS OUT QUICKLY WED
AFTN/EVENING AS FLOW GOES WNW. HIGHS IN THE U40S/NR 50 NW TO L60S
SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CDFNT CLRS THE CST WED EVE...CONTG E WED NGT...PUSHING MSTR WELL
OFFSHR. ZNL FLO ALOFT THU INTO NEXT WKND...RESULTING IN NR
SEASONABLE TEMPS. SFC HI PRES SLIDES OVR THE RGN THU INTO FRI...THEN
WKNS BY SAT. WK SFC LO PRES PASSING S OF THE FA SAT...MAY BRUSH SRN
VA/NE NC W/ PCPN (-RA) - OTRW P/MCLDY...B4 MVG OUT TO SEA SAT
NGT/SUN.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE LEFTOVER OF A BAY STREAMER WAS BRINGING STRATOCU TO THE ORF AREA
AT MIDDAY. THIS SHOULD MOVE OUT SHORTLY. GUSTY N WINDS AT ECG AND
ORF (AROUND 15 KT) SHOULD ALSO DIMINISH BY MID AFTN.
NAM AND GFS SUGGEST INCREASED MOISTURE IN THE 3-5K FT LEVEL
SE PORTIONS OF OUR AREA DURING THE DAY MON. INCLUDED BKN050 AT
ECG AFT 16Z. THIS WILL INCREASE BEYOND 18Z ALONG WITH A CHANCE OF
VERY LGT RAIN LATE MON/MON EVNG...MAINLY AT ORF AND ECG.
WIDESPREAD IFR AND PCPN CAN BE EXPECTED TUE NIGHT THROUGH WED AS
ANOTHER STORM SYSTEM IMPACTS THE AREA. VFR RETURNS BY THU.
&&
.MARINE...
SFC HI PRES ARRIVING FM THE W THIS EVE...AND IS SLO TO WKN/SLIDE
OFFSHR MON. WK SFC TROUGH TO CRS THE WTRS MON EVE...FOLLOWED BY
ANOTHER AREA OF WK HI PRES FM LTR MON NGT THROUGH TUE. NEXT STM SYS
TRACKS QUIKLY THE CNTRL PLNS (TUE) TO THE LWR LAKES RGN BY ERY WED.
SCNDRY LO PRES DVLPS INVOF CNTRL MTNS ERY WED...THEN CRSS THE MDATLC
STATES WED AFTN. ASSOCIATED CDFNT EXITS THE CST WED EVE...FOLLOWED
BY HI PRES FOR THU/FRI.
LINGERING (LO END) SCAS (MNLY FOR SEAS AOA 5 FT) ON THE OCN INTO ERY
EVE HRS (THROUGH 23Z...W/ XPCTN TO 00Z ON FAR NRN WTRS).
OTRW...WDSPDS RMN GENLY AOB 10 KT...AS DRCTN SHIFTS FM NNE TO SSW
TNGT THROUGH MON EVE. WNDSHFT TO NNW AND SPDS INCRSG TO 10-15 KT FM
MON NGT INTO TUE. FM TUE NGT INTO WED MRNG...ONSHR WNDS INCRS TO
SCA...RESULTING IN BUILDING WAVES/SEAS...THEN WDSHFT TO SSW XPCTD
WED AFTN. USED BLEND OF LCL WV GUID AND WVWATCH FOR WV/SEAS THROUGH
PD.
&&
.HYDROLOGY...
RIVER FLOOD WARNING FOR THE NOTTOWAY AT SEBRELL REMAINS IN EFFECT
THROUGH MIDWEEK. SEE WBCFLSAKQ FOR DETAILS.
&&
.EQUIPMENT...
NWR TRANSMITTER AT RIC IS EXPERIENCING PERIODIC OUTAGES. RADIO
IS ON AIR ATTM...BUT MAY EXPERIENCE INTERMITTANT OUTAGES TONIGHT
UNTIL SOURCE OF PROBLEM IS DETERMINED. SEE WBCPNSAKQ FOR MOST
TIMELY INFORMATION.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM/MPR
NEAR TERM...MPR/MAM
SHORT TERM...BKH/MAM
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
HYDROLOGY...AKQ
EQUIPMENT...AKQ
