FXUS61 KAKQ 020906
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
406 AM EST WED DEC 2 2009
.SYNOPSIS...
LOW PRESSURE OVER THE GULF COAST REGION WILL STRENGTHEN AS IT
TRACKS NORTHEAST AND UP ALONG THE WEST SIDE OF THE APPALACHIANS
TONIGHT. THE ASSOCIATED WARM FRONT WILL LIFT NORTH OVER THE REGION
THIS EVENING...FOLLOWED BY A COLD FRONT EARLY THURSDAY MORNING. THE
LOW MOVES INTO NORTHERN NEW ENGLAND BY THURSDAY AFTERNOON. HIGH
PRESSURE BUILDS INTO THE AREA ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS A CLOSED MID/UPR LOW CENTERED OVR TX THIS
MORN...AND A SFC LOW OVR THE NRN GOM, WHICH WILL DE-AMPLIFY AS IT
ACCELERATES NEWRD JUST W OF THE MTNS TODAY/TNGHT...REACHING CENTRAL
NY BY 12Z THU. THE WARM SECTOR FROM THIS SYSTEM WILL SPREAD NWD
ACROSS THE SERN STATES...REACHING THE FAR SRN FA AREA BY AS EARLY AS
LATE AFTN. (HV ADDED ISO THUNDER TO NC COUNTIES DURING THIS TIME.)
PER NATIONAL RADAR OVERRUNNING PRECIP IS BEGINNING TO REACH THE
CAROLINAS EARLY THIS MORNING...AND SHOULD BEGIN REACHING THE FAR SW
FA BY LATE MORNING.
LLVL FLOW INCREASES OUT OF THE SE...RESULTING IN BRZY/WNDY CONDS BY
LATE AFTRN. GENERALLY STUCK WITH A TRANSITION OF POPS INCREASING
OUT OF THE SW THROUGHOUT TODAY W/ CATEGORICAL POPS OVR MUCH OF THE
AREA BY LATE THIS AFTN. HI TEMPS M50S FAR NW TO M60S SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
MDLS REMAIN CONSISTENT WRT TRACK OF SYS, THOUGH THE GFS IS SLIGHTLY
DEEPER/STRONGER. WITH THE FA FIRMLY IN THE WARM SECTOR BY THIS
EVENING, SPC CONTINUES TO PLACE ALL OF SERN VA/NE NC IN A SLGHT
RISK...WITH THE MAIN THREATS BEING DAMGNG WNDS AND PSBL TORNADOS...
DUE TO VERY STRNG INCRG SHEAR. ISO THUNDER IS EVEN POSSIBLE ACROSS
NRN COUNTIES DUE TO THREAT OF ELEVATED CONVECTION. HV THUS
EXPANDED MENTION OF THUNDER TO REST OF THE FA..EXCEPT FOR FAR SW.
BY FAR THE BEST INSTABILITY AND SHEAR LIES OVR THE SE. AND THOUGH
THIS SYS IS A QUICK MOVER...IT HAS THE POTENTIAL TO PRODUCE 1 TO 2
INCHES OF QPF OVR THE AREA...WHICH IS ALREADY STILL VERY SATURATED
FROM PAST COUPLE OF EVENTS. ANY POSSIBLE FLOODING SHOULD BE
LOCALIZED...SO NOT PLANNING ON A FLOOD WATCH AT THIS TIME. HV
ADDED IN LOCALLY HVY RAINFALL WORDING TO THE FORECAST FROM 00-06Z
TONIGHT. HV ISSUED WIND ADVSY FOR COASTAL COUNTIES AS SSE
INCREASES THIS EVENING AND GUSTS UP TO 40-45 MPH CANNOT BE RULED
OUT ALONG THE COAST. TEMPS REMAIN STEADY ALL NIGHT AND DO NOT
BEGIN DROPPING OFF UNTIL LATE THU MORN POST FROPA. LOWS FROM U40S
XTREME NW CNTYS TO L60S SERN CSTL AREAS.
FRONT WILL BE QUICK TO EXIT OFF THE COAST THU MORN...BUT THEN STALLS
NEAR THE GULF STREAM. MAINTAINED LOW CHC SHWRS ALONG THE COAST
FOR A FEW HRS AFTR SUNRISE. AS FOR THE REST OF THE DAY...FLOW THEN TURNS
SW, ALLOWING SIG DRYING TO COMMENCE ACROSS THE REGION. TEMPS WELL
INTO THE 60S TO NR 70 SE.
THU NITE/FRI...SKIES START OUT M CLR THU NITE...THEN BECOME PT CLDY
AS HIGH/MID LVL MSTR APPRCHS FROM DVLPNG CSTL SYSTM. CAA SETS IN
WITH LOWS DROPPING INTO THE 30S TO L40S. CLDNS CONTS TO INCRS FROM
THE SE FRI. HIGHS U40S-L50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE FORECAST PROBLEM WL BEGIN FROM 00Z SAT AS ANOTHER SYSTEM IS
PROGGED TO AFFECT THE FORECAST AREA. THE MAIN CONCERNS ARE PRECIP
CHANCES AND AMOUNTS BUT MORE SPECIFICALLY PRECIPITATION TYPE. MODELS
INDICATE A RATHER PROGRESSIVE SYSTEM WITH THE LOW MOVING NORTHEAST
UP THE COAST FRIDAY NIGHT INTO SATURDAY MORNING. WITH SOME COLD AIR
IN PLACE AT 850 AND BELOW AND UNCERTAINTY....HAVE INCLUDED A CHANCE
FOR A RAIN/SNOW MIX MAINLY FROM EARLY TO MID SATURDAY MORNING. AS
THE SYSTEM MOVES ALONG...EXPECT THE WINTRY MIX TO BE RATHER
SHORT-LIVED AND QUICKLY CHANGE OVER TO ALL RAIN CONTINUING FROM THE
AFTERNOON INTO THE EVENING HOURS. A LINGERING SHOWER IS POSSIBLE
EARLY SUNDAY BUT EARLY THOUGHTS ARE FOR THE SYSTEM TO SWEEP OUT OF
THE AREA BY SUNDAY EARLY AFTERNOON.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
DETERIORATING CONDITIONS LATER TODAY...LOW LVL WINDS WILL INCREASE
AND BECOME SE OVER THE REGION (MORE ESE WELL INLAND). RAIN/LOWER
CIGS LOOK TO OVERSPREAD THE TAF SITES BETWEEN ABOUT 17/18Z AND
20/21Z. WIND SPEEDS WILL BECOME STRONG AND GUSTY ALONG THE
COAST...WITH GUSTS OF 30 TO 35 KT EXPECTED AT ORF/PHF/ECG BETWEEN
22Z AND 05Z (EXPECTING MORE LIKE 25 KT AT RIC).
WIND DIRECTIONS SHIFT TO THE SSW BETWEEN 03Z AND 06Z...WITH SKIES
CLEARING OUT BY DAYBREAK THU...WITH DRY CONDITIONS AND WEST WINDS
PREVAILING. ANOTHER SYSTEM LOOKS TO AFFECT THE REGION LATE FRI NGT
THROUGH SAT NIGHT...WITH A PERIOD OF LOWER CIGS/VSBYS AND
PRECIPITATION POSSIBLE.
&&
.MARINE...
CHALLENGING FCST OVER THE NEXT 24 HRS...BIG CHANGES ARE ON THE WAY.
SEAS EARLY THIS MORNING ARE RUNNING 2-3 FT OR LESS AND WINDS ARE
10-15 KT OR LESS. LOW PRESSURE OVER THE GULF OF MEXICO WILL RAPIDLY
STRENGTHEN TODAY AS IT TRACKS NNE TWDS THE OHIO VALLEY. COMBINED
WITH THE RETREATING SFC HIGH OFFSHORE...THERE WILL BE A STRONG
PRESSURE GRADIENT ACRS THE WATERS. TYPICALLY...SOUTHERLY GALES ARE
VERY RARE DUE TO LIMITED MIXING OVER THE COOL WATERS...BUT THIS
EVENT IS A LITTLE DIFFERENT AS THE WIND DIRECTIONS WILL INITIALLY BE
CLOSER TO ESE...AND AIRMASS ALOFT IS INITIALLY COOL. WITH THIS IN
MIND...HAVE HOISTED GALE WARNINGS ALL ZONES FOR THE EVENING HRS
(BEFORE THE WINDS VEER TO THE SSW AND THE MIXING POTENTIAL
DIMINISHES). STILL...THIS SHOULD BE A BORDERLINE/MARGINAL GALE EVENT
WITH MAJORITY OF THE AREA SEEING 25-30KT SUSTAINED WITH GUSTS TO
AROUND 35 KT. SEAS WILL BUILD SIGNIFICANTLY HOWEVER...ON THE ORDER
OF 10-13 FT OFFSHORE (WITH 8 FT+ NEARSHORE FOR THE ERN SHORE ZONES
AND HAVE RAISED A HIGH SURF ADSY THERE).
AFTER MIDNIGHT...AS FLOW VEERS TO THE SSW WILL HAVE WIND SPEEDS
CAPPED JUST BELOW GALE FORCE (EXCEPT LINGERING THROUGH 6AM OVER NRN
CSTL WATERS WHERE THE SHIFT OCCURS A BIT LATER). OFFSHORE FLOW THEN
PREVAILS THU ALLOWING SEAS TO RAPIDLY SUBSIDE TO 4-5 FT OR LESS BY
THU AFTN. ANOTHER SYSTEM...THIS TIME A COASTAL ONE WILL INCREASE
SEAS/WINDS ONCE AGAIN LATE FRI INTO SAT...WITH AT LEAST SCA
CONDITIONS LIKELY RETURNING.
&&
.TIDES/COASTAL FLOODING...
TOO FAST OF A WIND SHIFT FROM ONSHORE TO OFFSHORE FOR TIDAL
ANOMALIES TO BUILD TO MUCH MORE THAN 1 FOOT ABOVE NORMAL...AND THE
TIME OF THE HIGHER ANOMALIES (THIS EVENING) WILL COINCIDE WITH THE
LOWER OF THE 2 HIGH TIDES...HENCE DO NOT EXPECT TIDAL FLOODING
THRESHOLDS TO BE REACHED. IF ANYTHING...MAY EVEN SEE LOWER WATER
LEVELS THAN NORMAL BY THU AS OFFSHORE FLOW PREVAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EST TONIGHT
FOR MDZ025.
HIGH SURF ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY
FOR MDZ025.
NC...WIND ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EST TONIGHT
FOR NCZ017-102.
VA...WIND ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EST TONIGHT
FOR VAZ095-098>100.
HIGH SURF ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY
FOR VAZ099-100.
MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT
FOR ANZ630>633-654-656-658.
GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY FOR
ANZ650-652.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM...KLL
AVIATION...LKB
MARINE...LKB
TIDES/COASTAL FLOODING...LKB
