FXUS61 KLWX 021605
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1105 AM EST WED DEC 2 2009
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN MISSISSIPPI WILL TRACK INTO THE TENNESSEE
VALLEY TODAY...BEFORE MOVING THROUGH THE OHIO VALLEY AND INTO
UPSTATE NEW YORK TONIGHT. HIGH PRESSURE BUILDS IN THURSDAY NIGHT
AND FRIDAY. A COASTAL DISTURBANCE DEVELOPS OFF THE CAROLINAS
SATURDAY. HIGH PRESSURE TO RETURN FOR SUNDAY AND MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
CERTAINLY A PLATE FULL OF THINGS TO CONTEMPLATE THIS MRNG...FIRST
OFF PUSHED BACK THE START TIME OF THE WIND AVSRY FM 10 AM TO 3 PM.
NOTICED BLF JUST RCVD A GUST TO 45 KT..SO IT SEEMS LKLY THAT IT WL
GET HERE...JUST A FEW HRS LATER THAN PRVSLY XPCTD.
RAIN HAS ALREADY BEGUN IN THE CENTRAL SHEN HGLNDS W/ THE LEAD BAND
WELL AHD OF THE PARENT LOW. THIS WL OVERSPREAD THE ENTIRE CWA BY
MID AFTN...W/ HVIER PCPN MOVG INTO THE CHO AREA BTWN 21-00Z...THEN
ACROSS THE ENTIRE AREA BY 00Z. I'VE ADDED MENTION OF PTNL SMALL
STREAM FLDG TO THE HWO.
TEMPS RANGING FM U40S-M50S.
&&
.SHORT TERM /TONIGHT/...
THE LOW PRESSURE SYSTEM WILL MOVE INTO THE OHIO VALLEY OVERNIGHT...
PUSHING A FRONT THROUGH THE CWFA AFTER 06Z. WINDS ARE EXPECTED TO
SHIFT AROUND TO THE WEST TOWARDS SUNRISE. HAVE EXPIRED THE WIND
ADVISORY AT 10 PM...AGAIN THE HIGHEST WINDS ARE EXPECTED IN THE
HIGHER TERRAIN.
MODELS HAVE CONTINUED TO PRODUCE SOME INSTABILITY ALONG THE FRONT
OVERNIGHT. HAVE KEPT THE MENTION OF THUNDER OVERNIGHT FOR AREAS
ALONG AND EAST OF THE BLUE RIDGE. WITH STRONG WINDS ALOFT...EVEN
SHOWERS (AND DEFINITELY ANY THUNDERSTORMS) COULD PRODUCE SOME HIGHER
WIND GUSTS IN THE LOWER ELEVATIONS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THURSDAY MORNING...LOW CENTER OVER UPSTATE NY AND QUICKLY MOVING NE.
ANY LINGERING SHOWERS TO CLEAR THE BAY BY MID MORNING /IF NOT
EARLIER/ AS DRYSLOT/DOWNSLOPING CUTS OFF PRECIP. UPSLOPE PRECIP
PERIOD BEGINNING OUT WEST AS FLOW BECOMES WLY. DENSE PRESSURE
GRADIENT CONTINUES THROUGH THURSDAY WITH WINDS 25 TO 30 MPH
EXPECTED THROUGH THE AFTERNOON /35 MPH GUSTS ACROSS THE ENTIRE CWA
THURSDAY MORNING NOT OUT OF THE QUESTION/.
LATER THURSDAY THROUGH FRIDAY. OUT WEST...UPSLOPE RAIN FOR THE
ALLEGHENY FRONT THROUGH THE AFTERNOON HOURS BEFORE A CHANGEOVER TO
SNOW IN THE EVENING. ACCUMULATION BEGINS BY MIDNIGHT. UP TO A COUPLE
INCHES OF SNOWFALL EXPECTED FOR PRIME UPSLOPE LOCALES AT THIS TIME
AS GUIDANCE CONTINUES TO INDICATE WINDS SOUTH OF WEST AFTER SUNRISE
FRIDAY...CUTTING OFF GREAT LAKES MOISTURE SOURCE.
EAST OF THE ALLEGHENY FRONT...PARTLY CLOUDY CONDITIONS IN
DOWNLSOPING FLOW ALLOWS TEMPERATURES TO DROP TO AROUND 30F FOR THE
WESTERN VALLEYS AND LOW TO MID 30S EAST OF THE BLUE RIDGE /40F NEAR
SHORE/. THE JET STREAM INTENSIFIES OVERHEAD FRIDAY...EXPECT HIGH/MID
CLOUD COVER TO THICKEN THROUGH THE DAY LIMITING TEMPERATURES TO THE
UPPER 40S /MID TO UPPER 40S FOR VALLEYS/.
SATURDAY...DEEP CENTRAL CONUS TROUGH ROTATES FROM POSITIVE TILT DOWN
THE SOUTHERN PLAINS FRIDAY TO A NEGATIVE TILT TO THE SERN CONUS BY
SATURDAY MORNING. SOME WEAK FRONTOGENESIS ALONG BAROCLINIC ZONE ON
APPALACHIAN SPINE /BELOW THE JET/ COULD SQUEEZE OUT SOME SNOW FOR
BLUE RIDGE AND WEST LATE FRIDAY NIGHT/EARLY SATURDAY MORNING /WENT
FOR SCHC/. BROAD CYCLOGENESIS OFF THE CAROLINA COAST EXPECTED SAT
MORNING. SOME AREAS/BANDED PRECIP EXTENDING NORTHWEST INTO THE CWA
EXPECTED...TEMPERATURES COLD ENOUGH FOR SNOW EXCEPT OVER THE BAY.
INCLUDED SOME LOW CHANCES FOR SNOW OR RAIN/SNOW MIX...IMPACT
POTENTIAL LOOKS LOW AT THIS TIME...THOUGH THE SITUATION WILL
CONTINUE TO BE MONITORED CLOSELY.
SUNDAY AND INTO NEXT WEEK...TROUGH AXIS PUSHES OFF THE COAST
/PUSHING LOW WELL OUT TO SEA/ AS A RIDGE BUILDS OVER THE ERN CONUS.
TEMPERATURES SUNDAY/MONDAY AROUND EARLY DECEMBER NORMALS OF UPPER
40S FOR MAXES AND LOW 30S FOR MINS. THE NEXT DISTURBANCE LOOKS TO BE
TUESDAY AT THE EARLIEST.
&&
.AVIATION /THIS AFTN THROUGH SUNDAY/...
CIGS HV DROPPED TO MVFR AT KCHO...AND EARLY THIS AFTERNOON FOR THE
REMAINDER OF THE TERMINAL SITES. VSBYS MAY LOWER TO IFR VALUES
WITH THE HEAVIEST RAIN DURING THE LATE EVENING AND OVERNIGHT
HOURS...WITH THE CHANCE FOR THUNDERSTORMS.
GUSTY SWLY WINDS /25 TO POSSIBLY 30 KT/ THURSDAY MORNING AS FRONT
PUSHES THROUGH AND LOW PRESSURE CENTER LIFTS THROUGH UPSTATE NEW
YORK. WINDS BECOME WESTERLY FOR THE AFTERNOON WITH GUSTS 20 TO 25
KT. HIGH PRESSURE/VFR THEN THROUGH FRIDAY. LATER FRIDAY INTO
SATURDAY...MID LEVEL CLOUDS THICKEN AND LOW IN ADVANCE OF UPPER
TROUGH. COULD BE ENOUGH LIFT FOR SNOW /MIX WITH RAIN NEAR SHORE INCL
DCA/BWI/ ON SATURDAY. HIGH PRESSURE/VFR SUNDAY AND MONDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE OUT OF THE LOWER MISSISSIPPI RIVER VALLEY
INTO THE OHIO RIVER VALLEY TODAY AND TONIGHT. THE PRESSURE GRADIENT
IS EXPECTED TO BEGIN TIGHTENING LATER THIS AFTERNOON...WITH
SUSTAINED SE WINDS INCREASING...ALONG WITH THE GUST POTENTIAL. GUSTS
TO 25 KT WILL BECOME MORE LIKELY LATER THIS AFTERNOON. BUFKIT
SOUNDINGS SHOW THE POTENTIAL FOR GUSTS NEAR GALE FORCE OVERNIGHT
FOR THE LOWER TIDAL POTOMAC AND BAY. A GALE WARNING IN EFFECT FOR
THOSE AREAS.
STRONG LOW PRESSURE SYSTEM LIFTS AWAY FROM THE MID ATLANTIC THURSDAY
MORNING...ANY LINGERING SHOWERS OVER THE WATERS END MID MORNING.
STRONG SCA WINDS CONTINUE THROUGH WEDNESDAY MORNING WITH SWLY THEN
WLY FLOW IN THE WAKE OF THE SYSTEM. SCA EXPECT TO CONTINUE THROUGH
MOST OF THURSDAY NIGHT. HIGH PRESSURE/MORE TRANQUIL FRIDAY AS CLOUD
COVER THICKENS.
A COASTAL LOW DEVELOPS OFF THE CAROLINAS SATURDAY...INTENSITY OF
WHICH IS YET TO BE SEEN IN GUIDANCE. EXPECT MORE SCA/S OVER THE
WEEKEND.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS SLTLY ABV NRML WILL CONT TO RISE ON ESE FLOW TO ABT 1
FT ABV NRML. LATE AFTERNOON/EARLY EVENING HIGH TIDE MAY APPROACH
MINOR COASTAL FLOODING VALUES. WATER LEVELS SHOULD REMAIN ABOVE
NORMAL VALUES THURSDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS
EVENING FOR MDZ501.
VA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS
EVENING FOR VAZ021-025-026-029-036>040.
WV...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS
EVENING FOR WVZ054-501-503.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM EST THURSDAY FOR
ANZ530>534-537>543.
GALE WARNING FROM 6 PM THIS EVENING TO 4 AM EST THURSDAY FOR
ANZ530>534-537>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ535-536.
&&
$$
PRODUCTS...WOODY!
PRVS...NWL/BAJ
