Winter Weather in Virginia, December 14, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
930 PM EST SAT DEC 13 2003

WILL MAKE A FEW WORDING CHANGES TO THE FIRST TWO PERIOD OF THE
ZONES...BUT OVERALL CURRENT FORECAST LOOKS GOOD. ND

PREVS AFD

.SHORT TERM...
FEW RADAR ECHOES ACRS SRN CWFA ATTM...MARKING THE LEADING EDGE OF
SLY FLW ALFT. THIS RGN ASSOC W/ F-VCTR CNVGNC AS MNTND PAST CPL
DSCNS. NO EVIDENCE ANY RTNS REACHING GRND. IF IT WERE...PTYPE LIKELY
FLURRIES BASED UPON THRML PROFILE AND DEGREE OF DRY AIR AT SFC.

LOPRES DVLPG ALNG GLFMEX CST ATTM...W/ PRES FALLS INVOF TN/AL BRDR.
WATER VAPOR LOOP DEPICTING STREAM OF RICH MSTR WORKING NWD AHD OF
SYSTM. SO...THIS SYSTM WL HV PLENTY OF JUICE TO WORK WITH.
MEANWHILE...HIPRES CNTRD OVR GRTLKS RDGG DWN ACRS CWFA. THUS...
CLASSIC OVERRUNNING EVENT SETTING UP...W/ CAD LIKELY IN THE SHEN
VLY.

GFS/META/GEM FAIRLY COMPARABLE TRACKING SFC/H8/H5 LO ACRS AREA
TMRW. THUS...CWFA WL BE IMPACTED BY RAIN/SNW LINE AS ATLC AIR
BECOMES WRAPPED WWD INTO AREA AHD OF SYSTM TMRW. TKNS SCHEMES AND
ENERGY METHOD SUGGEST QUICK CHGOVR FM SNW TO IP/FZRA. PTMC
HIGHLANDS/CATOCTINS WL STAY COLD THE LONGEST...AND MAY NOT CHG OVER
PER H8 LOW TRACK. FCST OVRALL WL REFLECT SNW TO SLEET/FZRA MUCH OF
AREA TNGT...AND THEN TO FZRA/PL W AND TO RAIN E OF BLURDG TMRW.
TEMPS WL REMAIN IN 30S THRUOUT TMRW.

IN SHORT...WATCH AREA WL BECOME WRNGS. ADVSRYS WL BE POSTED TO THE
E. SNW ACCUM WL BE BIGGER CONCERN TO THE N...ICE ACCUM TO THE S.

THX SRRNDG OFFICES FOR COORD/COLLAB.
&&

.LONGER TERM...

ON SUNDAY EVE...SFC LOW PUSHES NE OF CWA AND FLOW TURNS NW BRINGING
COLDER AIR IN AT MID LVLS. THIS WILL TURN LINGERING PRECIP BACK
OVER TO SNOW CWA WIDE BETWEEN 00Z-06Z FROM W TO E. MODELS NOW AGREE
THAT A PERIOD OF WRAPAROUND LIFT WILL PUSH THROUGH SUNDAY NIGHT
MAINLY AROUND 06Z. WITH LOW LEVEL MOISTURE AROUND SOME MINOR
ADDITIONAL ACCUMULATIONS ARE ANTICIPATED.

EXPECT UP TO 3 INCHES OF ADDITIONAL ACCUMULATION ON FAR WESTERN
RIDGES SUN EVE THRU MON MORN...AROUND AN INCH OVER THE REST OF THE
NORTHERN HALF OF THE CWA MAINLY BEFORE 3 AM...AND LESS THAN ONE INCH
IN SOUTHERN THIRD WHERE ACTIVITY SHUD BE MORE LIKE FLURRIES DUE TO
DRY SLOT TRYING TO BUILD IN. MAY BE LITTLE OR NO ACCUMULATION IN FAR
SE ZONES WHERE A MIX OF RAIN AND SNOW MAY NOT BE ABLE TO CHANGE OVER
BEFORE THE PRECIP COMES TO AN END.

SCT UPSLOPE SHSN ON THE WESTERN RIDGES MON MORN WITH DRY WX
ELSEWHERE AS DRIER AIR MOVES IN. MOSUNNY BY AFT CWA WIDE. HAVE
UNDERCUT MODEL HIGHS MON DUE TO EXPECTED SNOWPACK.

A QUICK BREAK TUE AHEAD OF NEXT SYSTEM FCST TO DEVELOP OVER CENTRAL
PLAINS AND PUSH EWARD ACROSS CWA WED. LIFT FROM THIS SYSTEM STARTS
TO ARRIVE AROUND 00Z WED AND RAIN WILL OVERSPREAD THE AREA TUE NIGHT
AND CONTINUE THRU WED.

TEMPS LOOK WARM ENOUGH WITH RIDGING OVER CWA FOR LIQUID PRECIP
THROUGH WED AFT. HOWEVER WED EVE AS THE LOW PASSES COLD AIR MOVES IN
AS NW FLOW STARTS. UPPER LEVEL TROF BECOMES INVERTED OVER NEW
ENGLAND WHICH SLOWS EXIT OF LOW AND CAUSES LOW LEVEL MOISTURE AND
SOME LIFT TO LINGER INTO WED NIGHT. EXPECTING PRECIP TO MIX WITH OR
CHANGE OVER TO SNOW FROM W TO E WED NIGHT. NO MAJOR ACCUMULATIONS
BUT A DUSTING POSSIBLE BEFORE PRECIP COMES TO AN END. SHSN LINGERING
IN MTNS INTO THU MIDDAY. REST OF CWA IN PTCLDY SKIES AS MOISTURE
WRAPS AROUND FROM GREAT LAKES AS LOW SLOWLY PUSHES INTO NEW
ENGLAND.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY TONIGHT THROUGH SUNDAY EVENING DCZ001.

MD...WINTER STORM WARNING TONIGHT THROUGH SUNDAY EVENING MDZ002>005.
WINTER WEATHER ADVISORY TONIGHT THROUGH SUNDAY EVENING MDZ006>007...
MDZ009>011...MDZ013>014...MDZ016>018.

VA...WINTER STORM WARNING TONIGHT THROUGH SUNDAY EVENING VAZ021...
VAZ025>031...036>042...050>051.
WINTER WEATHER ADVISORY TONIGHT THROUGH SUNDAY EVENING VAZ052>057.

WV...WINTER STORM WARNING TONIGHT THROUGH SUNDAY NIGHT WVZ048>054.

MARINE...NONE.

HTS/MMARGRAF

HAZARDOUS WEATHER OUTLOOK...UPDATE
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
520 PM EST SAT DEC 13 2003

DCZ001-MDZ002>007-009>011-013-014-016>018-VAZ021-025>031-036>042-
050>057-WVZ048>055-141045-
ALBEMARLE VA-ALLEGANY MD-ANNE ARUNDEL MD-
ARLINGTON/FALLS CHURCH/ALEXANDRIA VA-AUGUSTA VA-BERKELEY WV-
CALVERT MD-CARROLL MD-CHARLES MD-CLARKE VA-CULPEPER VA-
DISTRICT OF COLUMBIA DC-FAIRFAX VA-FAUQUIER VA-FREDERICK VA-
FREDERICK MD-GRANT WV-GREENE VA-HAMPSHIRE WV-HARDY WV-HARFORD MD-
HIGHLAND VA-HOWARD MD-JEFFERSON WV-KING GEORGE VA-LOUDOUN VA-
MADISON VA-MINERAL WV-MONTGOMERY MD-MORGAN WV-NELSON VA-
NORTHERN BALTIMORE MD-ORANGE VA-PAGE VA-PENDLETON WV-
PRINCE GEORGES MD-PRINCE WILLIAM/MANASSAS/MANASSAS PARK VA-
RAPPAHANNOCK VA-ROCKINGHAM VA-SHENANDOAH VA-SOUTHERN BALTIMORE MD-
SPOTSYLVANIA VA-ST. MARYS MD-STAFFORD VA-WARREN VA-WASHINGTON MD-

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MARYLAND EAST OF GARRETT COUNTY
AND WEST OF THE CHESAPEAKE BAY...THE DISTRICT OF COLUMBIA...NORTHERN
VIRGINIA...THE NORTHERN AND CENTRAL SHENANDOAH VALLEY...AND THE
EASTERN PANHANDLE OF WEST VIRGINIA.

.DAY ONE...
A WINTER STORM WILL START TO AFFECT THE AREA TONIGHT.  CHECK THE
LATEST WINTER WEATHER MESSAGE FOR THE LATEST WATCHES...WARNINGS...OR
ADVISORIES.

.DAYS TWO THROUGH SEVEN...
THE WINTER STORM WILL CONTINUE TO AFFECT THE REGION THROUGH EARLY
MONDAY. SNOW...SLEET...FREEZING RAIN...AND RAIN ARE EXPECTED. IN
ADDITION...THE COMBINATION OF MELTING SNOW AND THE RAINFALL COULD BE
SUFFICIENT TO CAUSE FLOODING OF SMALL CREEKS AND STREAMS...AS WELL
AS LOW LYING AND POOR DRAINAGE AREAS. FLOODING OF SOME MAINSTEM
RIVERS IS ALSO POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS REQUESTED AT 400 AM SUNDAY MORNING FOR
PRECIPITATION REPORTS.

ND