FXUS61 KAKQ 080303 AAA
AFDAKQ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE WAKEFIELD VA
1003 PM EST MON DEC 7 2009
.SYNOPSIS...
A WEAKENING...DRY COLD FRONT CROSSES THE REGION THIS
EVENING...THEN HIGH PRESSURE RETURNS TONIGHT THROUGH TUESDAY. LOW
PRESSURE TRACKS NORTHEAST ALONG THE ATLANTIC SEABOARD
WEDNESDAY...WHILE A MORE INTENSE LOW PRESSURE SYSTEM TRACKS ACROSS
THE UPPER MIDWEST AND GREAT LAKES REGION. A COLD FRONT WILL PUSH
OFF THE MID ATLANTIC COAST BY LATE WEDNESDAY NIGHT...AS HIGH
PRESSURE BUILDS BACK INTO THE AREA THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
LATEST WX ANALYSIS DEPICTS ~1025MB SFC HIGH PRESSURE OVER THE
REGION THIS EVENING...WITH A QUICK/DRY COLD FRONT CROSSING THE
AREA. TO THE SOUTH...DEVELOPING LOW PRESSURE WAS NOTED ALONG SOUTH
TEXAS/NORTHERN MEXICO...WITH SHRAS AND EMBEDDED THUNDERSTORMS
BLOSSOMING ALONG THE CENTRAL GULF COAST IN ASSN WITH A WARM
FRONTAL BOUNDARY EXTENDING ACROSS E TEXAS...INTO SOUTHERN LA/MS.
ALOFT...SUBJECTIVE ANALYSIS REVEALS A FAST (QUASI- ZONAL) FLOW
OVER THE EASTERN CONUS...AHEAD OF A STRONG/DEEP AREA OF LOW
PRESSURE CURRENTLY OVER THE DESERT SOUTHWEST.
THE FRONT WILL CROSS THE AREA THIS EVENING...BRINGING ABOUT LTL
MORE THAN A WIND SHIFT FROM THE SW TO NW AFTER MIDNIGHT. RUC
SHOWING DRIER AIR AND WEAK NEG VORTICITY ADVECTION
OVERNIGHT...COURTESY OF AFOREMENTIONED DEEP LAYERED WNW FLOW. AS A
RESULT...WL HOLD ONTO MAINLY CLEAR SKIES EARLY ON TONIGHT...WITH
MID TO HIGH CLOUDS PUSHING IN LATER ON TONIGHT. SHOULD HV GOOD
3-5 HOUR WINDOW OF IDEAL RADIATING CONDITIONS BEFORE THIS
HAPPENS...SO HV DROPPED MIN T FORECAST ABT 2-3 DEG ACROSS THE
BOARD. LOWS UPR 20S NW TO NEAR 40 SERN ZONES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
TUESDAY...
SFC HIGH PRES QUICKLY RETREATS TO NEW ENGLAND WHILE MSTR
INCREASES OUT OF THE SW...AS YET ANOTHER SYSTEM HEADS TOWARD THE
REGION. MDL TRENDS CONTINUE TO FAVOR A SPLIT FLOW SOLN...WITH ONE
(MORE INTENSE) LOW SHIFTING THRU THE GREAT LAKES AND ANOTHER LOW
MVING NE ALONG THE ATLC COAST THRU EARLY THU. DID NOT STRAY FAR
FROM CURRENT POPS...WHICH INCREASE (FROM W TO E)TO CATEGORIAL TUE
EVENING...THEN 100% AFTER MIDNIGHT THRU EARLY WED MORN.
TEMPS TUE EVENING REMAIN MUCH TOO WARM FOR ANY WINTRY PRECIP...AND
WITH WAA OVERNIGHT THE NON-DIURNAL TEMP CURVE WILL CONTINUE TO KEEP
ALL PRECIP ACROSS THE FA IN THE FORM OF RAIN. LOW TEMPS WILL OCCUR
EARLY TUE EVENING BEFORE THE COASTAL LOW AND ASSOCIATED WARM FRONT
LIFT ACROSS THE REGION.
WEDNESDAY...
SYS A LITTLE SLOW IN EXITING TO THE NE ON WED...AT
LEAST SLOWER THAN PREV RUNS. HV CARRIED CATEGORICAL+ POPS SLIGHTLY
LONGER INTO EARLY WED BASED ON THIS TREND...THEN CLEARING OUT RAIN
BY WED AFTN/EVENING. AGREE WITH PREV FORECAST THAT THE AIR MASS
MAY BECOME MORE UNSTABLE AHEAD OF THE MID LAYER DRY SLOT..MAINLY
ACROSS SRN COUNTIES. SPC INCLUDED THIS AREA IN THEIR DY 2 DISC
BASED ON THE LARGE SCALE FORCING AND MOIST LLVL ENVIRONMENT...BUT
BASED ON THE MDLS BEST CHC FOR ANY INSTABILITY SHOULD REMAIN S OF
ALBEMARLE SND FOR NOW. BY THE EVENT'S END LATE ON WED, THE FA
COULD BE LOOKING ANOTHER 1 TO 1.5" OF PRECIP ACROSS AN ALREADY
WELL SATURATED REGION.
TEMPS FOR WED CONTINUE TO BE A CHALLENGE...BUT GENERALLY STUCK WITH
CURRENT FORECAST RANGING FROM MID 50S ACROSS THE FAR NW TO LOW 70S SE.
HIGH PRES RETURNS FOR THU. HIGHS MID 40S-MID 50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
COLDER THAN NRML PTRN APRS TO LOCK IN THE END OF THE WK AND FOR
WKND. SFC HI PRES FM THE W SLIDES OVR THE RGN THU NGT THROUGH
FRI...THEN IS SLO TO WKN ON SAT. XTNDD MDLS CONT TO HV DIFFICULTY W/
UPCOMING (NRLY) ZNL PTRN (ALOFT) ACRS CONUS. TMG OF WK SFC LO PRES
TRACKING ACRS THE GULF STATES THROUGH SE CONUS OVR THE WKND...APRS
TO BE (ATTM) TO BE ABT 12 HRS SLOER THAN WAS PORTRAYED YDA. CONTG W/
IDEA OF MSTLY LGT PCPN PTNTLLY BRUSHING (MNLY) SRN HALF VA/NE NC -
OTRW CLDY. LATEST/12Z07 GFS HAS PSBL AREA OF HIER QPF MVG ACRS THE
NRN PORTION OF VA/MD (ASSOCIATED W/ M/ULVL JET DYNAMICS)...THOUGH
UNCERTAIN ABT THIS PSBL PCPN ATTM. ALSO...NOT ALL THAT CONFIDENT ABT
FCST WRMG (IN L/MLVLS) FM SAT NGT INTO SUN MRNG NOR THE "SLOWING DN"
OF THE SYS UPON REACHED THE CST (ERY SUN MRNG) (AS DEPICTED BY
LATEST GFS). FAST/ZNL FLO ALOFT AND SHORT TIME FRAME FOR (SGFNT)
INCRSD LLVL FLO FM THE E OR S AS SFC HI RETREATS/SFC LO PRES TRACKS
BY TO OUR S. W/ THAT IN MIND...AND FOR SIMPLIFICATION AT THIS
STAGE...HV CHOSEN TO GO W/ CHC RA/SN MOST PLCS FM LT SAT INTO ERY
SUN...W/ FURTHER MODIFICATIONS LIKELY AS THE WK PROGRESSES.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
LITTLE CHANGE TO TAFS AS FCST REMAINS ON TRACK THIS EVNG. SCT TO BKN
HIGH CLDS CONTINUE TO MV FROM W TO E ACRS THE RGN. SW WNDS AROUND
5 KT WL BECOME NWRLY OVERNIGHT BEHIND COLD FRONTAL PASSAGE.
ONSHORE FLOW RESUMES BY TUE MRNG AS VFR CONDS CONTINUE.
A COMPLEX AREA OF LOW PRESSURE WL BEGIN TO AFFECT THE AREA TUE
EVNG. EXPECT CIGS TO LWR THROUGH TUE AFTN WITH MVFR BY TUE EVNG.
AS FOR PRECIP...COULD SEE A FEW AREAS OF RAIN MVNG INTO THE AREA
EARLY TUE EVNG. HOWEVER...THE MAJORITY OF PCPN SHOULD HOLD OFF
UNTIL AFTER 00Z WED. CONDITIONS IMPROVE TO VFR AND PCPN ENDS FROM
W TO E LATE WED AS LOW PRES PULLS OFF TO THE NE. WRLY WNDS THU WL
PROMOTE VFR CONDITIONS. HI PRES BUILDS INTO THE AREA FRI AND EARLY
SAT WITH GOOD WEATHER CONTINUING. AS THE NEXT WEATHER SYSTEM
APPROACHES FROM THE SW...CLOUDS MAY THICKEN OVER THE TAF SITES BY
SAT AFTN.
&&
.MARINE...
SFC TROUGH TO CRS THE WTRS ERY TNGT...FOLLOWED BY AN AREA OF WK HI
PRES FM LTR TNGT THROUGH TUE. NEXT STM SYS TRACKS QUIKLY FM THE
CNTRL PLNS (TUE) TO THE LWR LAKES RGN BY ERY WED. SCNDRY/TRPL PT 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.
WDSPDS THROUGH ERY TNGT RMN GENLY AOB 10 KT...AS PREVAILING STAYS
WSW. DRCTN SHIFTS TO NNW AND SPDS INCRSG TO 10-15 KT FM FM AFT MDNGT
TNGT 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. LIKELY TO NEED SCAS FM ARND A CPL HRS (B4 OR AFT) MDNGT TUE NGT
THROUGH WED NGT (PTNTLLY LNGR AS NEXT LLVL CAA PD XPCTD LT WED NGT
INTO ERY FRI).
&&
.HYDROLOGY...
RIVER FLOOD WARNING FOR THE NOTTOWAY AT SEBRELL REMAINS IN EFFECT
THROUGH MIDWEEK. SEE WBCFLSAKQ FOR DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TUESDAY NIGHT TO 6 PM EST
WEDNESDAY FOR ANZ630>633-650-652-654-656-658.
&&
$$
SYNOPSIS...SMF/MAM
NEAR TERM...SMF/MAM
SHORT TERM...SMF
LONG TERM...ALB
AVIATION...AM
MARINE...ALB
HYDROLOGY...
