FXUS61 KLWX 260243 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
943 PM EST FRI DEC 25 2009
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST INTO
EARLY SATURDAY. HIGH PRESSURE WILL BRIEFLY BUILD OVERHEAD SUNDAY.
AN UPPER LEVEL LOW PRESSURE AND SURFACE COLD FRONT WILL MOVE
ACROSS SUNDAY NIGHT AND MONDAY...WITH HIGH PRESSURE BUILDING IN
FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A MUCH QUIETER UPDATE THAN THE PAST FEW UPDATES. THE ONLY RESIDUAL
HAZARDS FROM THE EXITING STORM SYSTEM ARE THE FLOOD WATCH FOR THE
NORTHEASTERN-MOST PORTION OF MD AND THE SCA ACROSS THE WATERS.
LIGHT RAIN STILL COVERING MUCH OF THE CWA...BUT TRENDING DOWN AS
THE INTENSITIES AND COVERAGE DECREASE LATE TONIGHT.
EASTERLY SFC FLOW STILL HOLDING STRONG AS AN EMBEDDED SFC LOW
BEGINS TO WRAP-UP DOWN ACROSS SRN VA AND TRACKS NEWD OVERNIGHT.
THIS WILL CONTINUE TO REINFORCE LIFT E OF THE BLUE RIDGE...KEEP
TEMPS MODERATED AND ABOVE FREEZING OVERNIGHT. THE MIXING THAT HAS
TAKEN PLACE THROUGH THE EVENING HRS WILL PREVENT AREAS OF
WIDESPREAD DENSE FOG TO REDEVELOP AFTER THE RAIN ENDS. LOCALIZED
DENSE FOG COULD STILL MAKE APPEAR IN SHELTERED VALLEY REGIONS
ACROSS THE WRN ZONES-FOOTHILLS-PIEDMONT TOWARD THE PRE-DAWN HRS.
THE LOW-LEVEL JET WILL MAXIMIZE IN INTENSITY OVER CNTRL
PA...TAPERING-OFF BACK INTO NERN MD THRU THE NEXT SEVERAL HRS.
ALONG W/ THIS FEATURE WILL GO THE MAIN FORCING FOR THE PRECIP
WHICH WILL ALSO SLIDE NEWD INTO EARLY SAT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
LOW PRESSURE WILL SLOWLY MOVE NORTHEAST SATURDAY EVENTUALLY
REACHING SOUTHERN NEW JERSEY BY SATURDAY EVENING. RAIN WILL END
FROM SOUTHWEST TO NORTHEAST DURING THE DAY. CLOUDS WILL BREAK FOR
SOME SUNSHINE ACROSS THE SOUTHWESTERN CWA...FURTHER NORTH AND EAST
CLOUDS MAY HANG ON FOR MUCH OF THE DAY.
MAX TEMPS WILL BE IN THE 40S AND LOWER 50S ACROSS MOST LOCATIONS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
DP VERT STACKED SFC-H5 LOPRES STILL SPIRALS INVOF GRTLKS SAT
NGT-SUN. LCLLY AREA WL BE W/IN SUBSIDENCE FM RDGG BTWN LOW AND CDFNT
TO THE E. THAT WL LEAD TO MAINLY DRY CONDS...W/ PERHAPS A FEW
SPRNKLS/FLURRIES SLIDING INTO THE MTNS /CLSR TO PVA/ LT SUN. WUD
ALSO XPCT AT LEAST PRTL CLRG SAT NGT BEFORE MSTR/CLDS ADVECT BACK ON
SUN. CPLD W/ CU DVLPMNT DUE TO THE STEEPER LAPSE RATES...SUN SHUD BE
A MOCLDY DAY.
SPEAKING OF TEMPS...CAA YET TO COMMENCE IN EARNEST BY THIS PT. RADL
COOLING WL BE DECENT AT NGT...BUT MAXT WL BE CLS TO NRML.
THE UPR LOW FINALLY FILLS AND EJECTS EWD SUN NGT-MON. LOOKING FOR
SCT SHSN ACRS ENTIRE CWFA SUN NGT /WRN SLOPES OF APPLCHNS SHUD
RECEIVE A DECENT SNWFL OUT OF THIS/ THEN REVERT BACK TO A MAINLY MTN
PTTN DURING MON. SINCE MD N OF DC WL BE VERY NEAR THE TRACK OF THE
UPR LOW...WL BE KEEPING SCHC THERE AS WELL...AS FEEL THERE SHUD BE A
FEW FLURRIES ARND. THIS WL BE WHEN THE CAA RESUMES...AND TEMPS ONCE
AGN BLO SEASONAL MEANS.
HIPRES BLDS ACRS CWFA TUE-WED. TEMPS RMN BLO NRML THRU THE PD. ATTN
THEN DRAWN TWD THE GLFMEX CST...WHERE WK LOPRES DVLPS WED NGT-ELY
THU...AND EJECTS OFF THE CAROLINA/DELMARVA COAST AOB 12Z FRI. IF
THAT PANS OUT /AND THERE/S A LOT OF ROOM FOR THINGS TO CHG/ THERE
CUD BE ANTHR SNW STORM FOR CWFA NEW YRS EVE/DAY. ATTM...THREAT WL
BE REPRESENTED BY CHC SN THU NGT...SPCLY FOR ERN SXNS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
RAIN WILL CONTINUE TO AFFECT THE TERMINALS LATE TONIGHT INTO
SATURDAY MORNING..THOUGH COVERAGE AND INTENSITY WILL DECREASE OVER
TIME AND ESPECIALLY INTO THE PRE-DAWN HOURS. CIGS AND VSBYS WILL
REMAIN IFR/SUBIFR DURING THIS TIME. VSBYS WILL IMPROVE LATER
SATURDAY MORNING AND AFTERNOON ONCE THE RAIN STOPS...BUT IFR CIGS
ARE POSSIBLE THROUGHOUT MUCH OF THE DAY...ESPECIALLY ACROSS THE
NORTHERN AND EASTERN TERMINALS.
VFR THRU SUN...THEN MVFR PSBL SUN NGT AS UPR IMPULSE PASSES...
SUPPORTING SCT SHSN. CHCS BEST AT MRB. A FEW FLURRIES MAY LINGER
INTO MON. WL BE A VFR/OCNL MVFR MIX.
VFR REST OF PD.
&&
.MARINE...
WINDS WILL CONTINUE TO INCREASE FROM THE EAST AHEAD OF LOW PRESSURE
TONIGHT. WINDS WILL SLOWLY DIMINISH SATURDAY BEHIND THE LOW. WIND
GUSTS TONIGHT AROUND 30 KNOTS ARE EXPECTED ACROSS THE LOWER TIDAL
POTOMAC AND CHESAPEAKE BAY.
WATERS WL BE BTWN CDFNT TO THE E AND LOPRES OVR GRTLKS. NO FLAGS
XPCTD SAT NGT-SUN AS NW WNDS BACK TO THE S. UPR IMPULSE WL PASS
MON...WHICH WL SWING WNDS BACK TO THE NW AND INCR SPDS. SCA PSBL.
&&
.HYDROLOGY...
FLOODING CONCERNS WILL CONTINUE TO DECREASE LATE TONIGHT AND INTO
THE EARLY MORNING HOURS. WIDESPREAD LIGHT RAIN WILL CONTINUE TO
FALL ACROSS MUCH OF THE AREA INTO THE EARLY MORNING HOURS...THOUGH
QPF WILL BE LIGHT AND ACCUMULATED OVER SEVERAL HOURS.
FOCUS WILL SHIFT TOWARD THE EFFECTS OF SNOW-MELT AND EFFECTS ON
AREA RIVERS THROUGH THE NEXT FEW DAYS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FLOOD WATCH UNTIL 6 AM EST SATURDAY FOR MDZ005>007-010-011-014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ530>534-
537>543.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR ANZ535-536.
&&
$$
UPDATE...GMS
PREV DISCUSSION...BJL/HTS
