053
FXUS61 KLWX 210213 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 PM EST FRI NOV 20 2009
SYNOPSIS
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SATURDAY. HIGH
PRESSURE WILL RETREAT TO THE NORTH SUNDAY AND LOW PRESSURE WILL MOVE
UP THE EASTERN SEABOARD SUNDAY NIGHT THROUGH MONDAY NIGHT...BRINGING
ANOTHER ROUND OF RAIN. HIGH PRESSURE WILL RETURN TUESDAY...BUT A
COLD FRONT WILL PASS THROUGH DURING THE MIDDLE OF NEXT WEEK.
NEAR TERM /UNTIL 7 AM SATURDAY MORNING/
A RESIDUAL UPPER WAVE REMAINS BACK TO THE NW...SLIDING DOWN THRU
THE UPPER MIDWEST TONIGHT W/ LITTLE-NO PRECIP BUT A LARGE MASS OF
LOW CLOUDS STREAMING FROM THE SHORES OF LAKE ERIE DOWN INTO THE
CNTRL APLCNS. THIS WILL BE ABOUT THE ONLY WX ACTIVITY FOR THE
REGION INTO THE EARLY PART OF THE WEEKEND. PORTIONS OF THIS CLOUD
BANK WILL BREAK-UP AND SLIDE DOWN ACROSS THE NRN SHENANDOAH VLY
AND POTOMAC HIGHLANDS THRU THE OVERNIGHT HRS. WINDS DECREASING
AND AFTER A LONG PERIOD OF NWLY WINDS THIS AFTN...CONDITIONS ARE
RELATIVELY DRY...SO WIDESPREAD FOG DEVELOPMENT NOT EXPECTED
/OUTSIDE OF SHELTERED VLYS AND OTHER TYPICAL FOG-PRONE AREAS
TOWARD THE PRE-DAWN HRS/. THE RELATIVELY DRY CONDITIONS WILL ALSO
ALLOW TEMPS TO SLIDE DOWN INTO M/U30S /L40S IN THE METRO AREAS AND
CLOSER TO THE BAY/.
SHORT TERM /7 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/
SURFACE HIGH WILL REMAIN OVER THE REGION SATURDAY BRINGING DRY AND
SEASONABLE CONDITIONS. MAX TEMPS WILL BE IN THE MID TO UPPER 50S
ACROSS MOST LOCATIONS. MOSTLY/PARTLY SUNNY SKIES ARE EXPECTED WITH A
SCATTERED CU DECK DUE TO DIURNAL HEATING AND SOME HIGH CLOUDS DUE TO
A SOUTHWEST FLOW ALOFT.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
LRG HIPRES HANGING OUT ACRS THE NE/GRTLKS RGN SAT NGT-SUN. DIFF THIS
CYCLE IS THE COMBO OF SFC HIGH AND H5 RDGG...MAKING IT HARDER TO
DISLODGE. THRFR..GDNC THIS CYCLE SLOER THAN PRVS CYCLES. GFS SEEMS
TO BE QUICKER...BUT IT ALSO SEEMS TO BE AFFECTED BY GRIDSCALE
FEEDBACK...OWING TO S/WV PHASING. GGEM/NAM IN CONCERT...SUGGESTING
PCPN WL BE CENTERED ON SUN NGT-MON. A WK LOW WL THEN EMERGE OFF MID
ATLC CST MON NGT. WL MAKE APPRO CHGS TO GRIDS. ONE THING OF NOTE IS
THAT THERE/S NO COLD AIR ARND. AFTR MAKING APPRO MOS TEMP
ADJUSTMENTS /NEGLECTING THE COOLER MAXT OF WET GFS AND SIDING WARMER
SUN NGT AS CLDS ADVECT NWD/...MAXT WL BE NEAR NRML BUT MIN-T WARMER
THAN NRML.
SHUD GET A RESPITE TUE BEFORE ANTHR STORM AFFECTS CWFA IN THE
WED-THU TIMEFRAME. WL NEED TO MONITOR DUE TO TRAVEL IMPACTS. ATTM...
THE WARM TREND CONTS AS A CUTOFF H5 LOW DVLPS W OF THE MISSISSIPPI.
AVIATION /01Z SATURDAY THROUGH WEDNESDAY/
HIGH PRESSURE WILL BRING VFR CONDITIONS THROUGH SATURDAY. A
SCATTERED STRATUS DECK /3-4 KFT/ WILL CONTINUE TO DRIFT IN FROM
THE NW /BUT ONLY IN SMALLER PORTIONS FROM ITS LARGER MASS - BACK
ACROSS OH/WRN PA. THIS AREA OF CLOUDS WILL CONTINUE TO MOVE INTO
THE AREA TOWARD SATURDAY MORNING AND INTO THE AFTERNOON...DRIFTING
THRU AND DISSIPATING BY LATER IN THE EVNG. WIND SPEEDS WILL REMAIN
BELOW 10 KNOTS THRU THIS TIME.
VFR THRU SUN. FLGT RESTRICTION DUE TO LOPRES SUN NGT-MON NGT.
MARINE
NLY WINDS WILL CONTINUE TO MOVE OVER THE WATERS OVERNIGHT...AND
HIGH PRESSURE BEGINS TO MOVE IN FROM THE WEST...THOUGH WINDS WILL
BE LIGHT W/ A MINIMAL PRES GRADIENT...SO NO WX CONCERNS INTO THE
WEEKEND.
NO FLAGS XPCTD THRU THE WKND. LOPRES AFFECTING WATERS MON. WNDS MAY
PICK UP IN ADVC OF LOW...W/ A ENELY FETCH.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
UPDATE...GMS
PREV DISCUSSION...BJL/HTS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page