026
FXUS61 KLWX 271500 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1000 AM EST FRI NOV 27 2009
SYNOPSIS
LOW PRESSURE WILL CONTINUE TO MOVE OFF THE NEW ENGLAND COAST
TODAY...WHILE HIGH PRESSURE IS MOVING INTO THE CENTRAL
APPALACHIANS. THE HIGH WILL BUILD ACROSS THE AREA THIS WEEKEND.
A COLD FRONT WILL REACH THE EAST COAST MONDAY. HIGH PRESSURE WILL
RETURN TUESDAY...FOLLOWED BY AN AREA OF LOW PRESSURE ACROSS
SOUTHEAST VIRGINIA THURSDAY.
NEAR TERM /UNTIL 8 PM THIS EVENING/
ONE AREA OF ACTIVITY LEAVES...ANOTHER ENTERS. SUCH IS THE CASE W/
THE COMPLEX LOW PRESSURE SYSTEM ROTATING AROUND THE NORTHEAST. A
WEAK CONVECTIVE BAND OF SHOWERS/STORMS MOVED THRU OVERNIGHT...W/
A TENDENCY TO MIX SOME OF THE STRONGER LOW LEVEL WINDS TO THE SFC.
THIS AREA HAS SINCE MOVED WELL EAST OF THE AREA...NOW TRAVELING
OVER DELMARVA...LEAVING A BROAD AREA OF INACTIVITY BETWEEN IT AND
THE INCOMING AREA OF UPSLOPE SNOW ACROSS THE APLCNS.
A WINTER WX ADVISORY OUT FOR THE WRN 5 ZONES INTO THE OVERNIGHT
HRS...W/ EXPECTATIONS OF A COUPLE OF INCHES ACROSS THE HIGHER
TERRAIN...LESSER AMOUNTS DOWN INTO THE ADJACENT VALLEYS. TEMPS IN
THE L40S OUTSIDE OF THE RIDGELINES...SO MAINLY RAIN FOR MANY OF
THESE AREAS THIS MRNG. AS THE DAY PROGRESSES...THE CAA BURST
ASSOCIATED W/ THE INCOMING LAST UPPER VORT LOBE W/ DROP TEMPS
ACROSS THE WRNMOST ZONES...AND THE DOWNSLOPING WILL WARM AREAS
TO THE EAST OF THE ALLEGHENY MTNS.
TEMPS WILL TOP OUT IN THE U40S-L50S ACROSS THE VA/MD PIEDMONT...
THO IT WILL FEEL MUCH COLDER /IN THE U30S-L40S/ AS WINDS PICK UP
INTO THE 15-25 MPH RANGE LATER THIS MRNG AND INTO THE AFTN HRS.
BANDS OF INCOMING STRATUS WILL BREAK-UP A BIT OVER THE MTNS AND
SLIDE THRU THE AREA...SO SKIES WILL BE INTERMITTENTLY MOSTLY
CLOUDY-MOSTLY SUNNY.
A FAIRLY PRONOUNCED AREA OF LOW LEVEL MOISTURE SLIDING INTO THE
WRN SLOPES OF THE CNTRL APLCNS...AND A SMALLER PORTION OF THIS
MAKING IT EAST...INTO THE NRN SHENANDOAH VLY AND NRN PIEDMONT.
SO...AN ISOLATED SHOWER DOWN ACROSS EVEN THE METRO AREAS NOT OUT
OF THE QUESTION THIS AFTN.
SHORT TERM /8 PM THIS EVENING THROUGH 6 AM SATURDAY/
HIGH PRES BLDG OVR THE AREA. WINDS SHOULD BEGIN DIMINISHING BY
MDNGT. BLV BY MRNG SAT SKIES SHOULD BE CLRG. LOWS RANGE FM M20S
MTNS TO U30S BY THE WATERS.
LONG TERM /SATURDAY THROUGH THURSDAY/
ZONAL FLOW ALOFT WILL DEVELOP THIS WEEKEND WHILE SFC HIPRES BUILDS
IN FROM THE GULF STATES...RESULTING IN DRY WX AND MODERATING TEMPS.
MAX TEMPS SAT RANGING FROM THE U40S TO M50S AND SUN FROM THE M50S TO
L60S.
NEXT UPPER SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL PUSH THRU
QUICKLY ERY NEXT WEEK WITH PROGRESSIVE WX PATTERN OVER THE CONUS
CONTINUING THRU THE FIRST HALF OF NEXT WEEK. PREFERRED A BLEND
BETWEEN THE FASTER GFS AND SLOWER ECMWF SOLUTION REGARDING FROPA
SOMETIME MON/MON NGT. AFTER HIPRES BRIEFLY BUILDS IN TUE...LONG
RANGE MODELS HINT AT A STORM SYSTEM EMBEDDED IN THE SUBTROPIC JET
STREAM TO DEVELOP ALONG THE GULF COAST AND MOVE NEWD TOWARDS THE MID
ATLANTIC REGION WED INTO THU.
AVIATION /14Z FRIDAY THROUGH TUESDAY/
GUSTY WNW WINDS NOW MAKING THEIR ENTRANCE ACROSS THE MID ATLC...
SPREADING WELL INTO THE METRO AREAS AND SURROUNDING REGIONS. THE
ONLY CHANGE ON THAT FRONT WILL BE A STEADY INCREASE DURING THE
EARLY AFTN HRS...THEN JUST HOVERING IN THE 20-30KT RANGE /FOR
GUSTS/ INTO THE EVNG HRS. SCATTERED STRATUS DECKS SLIDING INTO THE
REGION FROM THE APLCNS...BUT ONLY A PORTION OF THIS MAKING IT E OF
MTNS /MAINLY SCT-BKN 4-5KFT/. ONLY ISOLATED SHOWERS POSSIBLE...THO
WINDS IN THE LOWEST FEW THOU FT THE BIGGEST CONCERN TODAY /DIR
280-310 STEADY/.
WNW FLOW WILL GRADUALLY RELAX SAT BUT REMAIN GUSTY WITH WINDS
15-20 KT AND A FEW GUSTS TO 25 KT IN THE MRNG. VFR CONDITIONS THRU
ERY NEXT WEEK. THE NEXT CHANCE FOR SHOWERS WILL BE MON/MON NGT AS
COLD FRONT PASSES THRU MON NGT. HIPRES BRIEFLY BUILDS IN BEHIND
THE FRONT TUE/ERY WED.
MARINE
SOLID SCA CONDITIONS ACROSS THE WATERS INTO THE EARLY AFTN
HRS...THO GALE WINDS WILL INTERMITTENTLY BEGIN TO APPEAR WITHIN
THE NEXT COUPLE OF HRS. GALE NOW IN EFFECT FOR ALL BUT THE 2 WRN
TDL PTMC ZONES...DIMINISHING TNGT BUT WINDS RMNG AT SCA LVLS.
SOLID SCA CONDITIONS EXPECTED ACROSS THE WATERS SAT BEFORE RELAXING
SAT EVNG INTO SUN AS THE COASTAL LOW MOVES INTO THE CANADIAN
MARITIMES. HAVE ACCORDINGLY EXTENDED HEADLINES TO KEEP SCA ACROSS
ALL MARINE ZONES THRU 23Z SAT. GUSTS TO 30 KT ARE STILL POSSIBLE
OVER THE MD CHSPK BAY SAT MRNG.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR VAZ021.
WV...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR WVZ054-501-
503.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR
ANZ530>534-537>543.
GALE WARNING UNTIL 6 AM EST SATURDAY FOR ANZ530>534-537>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR ANZ535-536.
UPDATE...GMS
PREV DISCUSSION...WOODY!/JRK
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