Winter Weather in Virginia, January 9, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
120 AM EST WED JAN 9 2002

OPERATIVE WORD FOR THE NEXT TWO DAYS FOR THIS FORECAST PACKAGE...
MILDER. OF COURSE THERE IS SOME VARIATION IN MOS MDL GUIDANCE TEMPS
FOR THURS...WITH THE NGM COMING IN ANYWHERE FROM 5 TO AS MUCH AS 10
DEG F COOLER THAN THE NEW 00Z AVN/MAV MOS GUIDANCE. WILL ADDRESS
THIS ISSUE LATER IN THIS DISCUSSION.

DISC:  OVERALL THE WEATHER PATTERN OVER THE U.S. IS RELATIVELY FREE
OF ANY SIGNIFICANT ARTIC AIR THROUGH THE NEXT WEEK. OVER THE ERN
U.S. A ZONAL FLOW WILL KEEP THE COLD AIR BOTTLED UP IN CANADA. EVEN
TONIGHT...AT MIDNIGHT THE TEMPERATURE OF 47 DEG-F IN BISMARCK ND IS
A SHADE HIGHER THAN THE 46 DEG READING FOUND AT PALM BEACH FL EVEN
FOR OUR MID-ATLANTIC REGION...FOR THIS PACKAGE IT WILL BE MOSTLY
NORMAL TO ABOVE NORMAL FOR TEMPERATURES THROUGH THE NEXT SEVEN DAYS.
HENCE THE THREAT IS SMALL FOR ANY SIG ARTIC AIR OUTBREAK AND/OR BIG
SNOW FOR THE AREA.

FOR THEN NEXT SRVL DAYS...WE WILL SEE A MODERATION IN TEMPS BOTH
TODAY AND THUR. AN AREA OF LOW PRES WELL TO THE NORTH OVER ONTARIO
CANADA WILL MOVE E INTO THE GULF OF ST. LAWERENCE BY LATE THUR. A
COLD FRONT FROM THIS LOW WILL GRADUALLY DROP ACROSS THE MIDWEST AND
INTO THE SOUTHERN PLAINS ON THU. A WEAK AREA OF LOW PRES WILL
DEVELOP ON THE FRNT. THIS LOW WILL MOVE FROM THE SOUTHERN PLAINS
REGION ON THU NE INTO THE MID-ATLANTIC REGION ON FRI AND THEN MOVE
OFF THE DELMARVA COAST FRI NIGHT.

OVERALL OUR AREA WILL BE IN A WESTERLY ZNL FLOW ALOFT THROUGH THU
ALLOWING FOR A MODERATION IN TEMPS. FRCST 85 HPA TEMPS TODAY WILL BE
A GOOD 4-7 DEG C WARMER TODAY THAN YESTERDAY BEHIND A DRY WARM FRONT
THAT WILL CROSS MOST OF THE ENTIRE EASTERN U.S. TODAY. SEVERAL UPR
LVL SHORT WAVES ARE INDICATED BY THE MDLS DROPPING DOWN FROM CANADA
AND DIGGING SE OVER THE WRN/CNTRL U.S. HOW THESE WAVES WILL INTERACT
IS ABIT UNCERTAIN RIGHT NOW. BUT BOTH THE 00Z EXTND ETA AND AVN MDLS
SHOW AN UPR LVL 50 HPA TROUGH TO FORM OVER THE CENTRAL U.S. BY
FRI...WITH THIS TROUGH SWEEPING EASTWARD FRI AND OFF THE COAST FRI
NIGHT...FOLLOWED BY ANOTHER UPR LVL WAVE TO MOVE OVER OUR AREA ON
SUN.

TODAY...SO JUST HOW WARM WILL IT GO TODAY AND THU. THINK THAT TODAY
THE AVN/ETA MOS MAX TEMPS ARE IN REASONABLE AGREEMENT AND LOOK
REASONABLE UNDER PRTLY SUNNY SKIES.

FOR TODAY...EXPECT PARTLY SUNNY SKIES OWING TO THE PASSAGE OF OUR
WARM FRONT TODAY. TEMPERATURE READINGS WILL BE MILDER WITH SW-RLY
WINDS.

TONIGHT...MORE PARTLY CLOUDY SKIES WITH TEMPS NOT AS COLD.

FOR THUR...BOTH THE 00Z AVN AND ETA FRCST 85 HPA TEMPS THU ARE
ACTUALLY A FEW DEG C COOLER THAN FOR TDY. ALSO BOTH MDLS SHOW MID/HI
LEVEL MOISTURE COMING IN FOR EARLY THUR. THE QUESTION IS WHETHER
THIS WILL RESULT IN A BAND OF HIGH RH RESULTING IN WIDESPREAD
CLOUDINESS THU WHICH WOULD TEND TO KEEP TEMPS DOWN ABIT AT LEAST
FROM CURRENT MAV MOS MAXES. THINK THE FWC MOS MAX TEMPS ON THU ARE
CLOSER TO REALITY...BUT WILL RAISE THEM A CAT OR SO.

FOR FRI...AS THE LOW MOVES NE...CLDS INCREASE AS DOES OUR RAIN
CHANCES LATE THUR AND FRI. ALOT OF THE PCPN WILL BE RELATED TO THE
UPR LVL JET DYNAMICS (RGT-REAR QUAD OF THE JET). THINK THE BEST
CHANCE FOR RAIN WILL BE DURING THE DAY ON FRI...BUT ENDING FROM NW
TO SE FRI EVENING...JUST AS THE COLDER AIR STARTS TO MOVE IN.

FRI NIGHT...CURRENT FRCST RECOGNIZED POTENTIAL THAT AS THE LOW MOVES
OFF THE COAST FRI NIGHT AND EARLY SAT...THERE COULD STILL BE SOME
LINGERING SHOWER ACTIVITY FRI NIGHT. WITH COLDER...SUB-FREEZING AIR
EXPECTED TO FILTER INTO THE REGION FRI NIGHT...THERE IS MENTION OF
FRZN PCPN. HOWEVER...AT THIS TIME...AFTER LOOKING AT THE NEW 00Z AVN
AND 84 HR ETA EXTNSN...THINK THE THREAT IS PRETTY SMALL AND WILL
REMOVE FROM CURRENT FRCST SAVE FOR A MENTION OF -SNSH IN OUR WRN
ZNS. SO WE WILL KEEP AN EYE OUT FOR THIS POTENTIAL

SATURDAY THROUGH TUESDAY...SHOULD BE DRY THROUGH THE REMAINDER OF
THE EXTENDED WITH SEASONABLE TO SLGHTLY ABOVE NORMAL READINGS.

.LWX...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.

SMZ

DCZ001-MDZ004>006-009>011-VAZ039>042-051>054-091300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
600 AM EST WED JAN 9 2002

AN AREA OF LIGHT FREEZING RAIN HAS FORMED OVER LOUDOUN COUNTY
VIRGINIA AND FREDERICK COUNTY MARYLAND. THIS IS EXPECTED TO MOVE
SLOWLY EAST OVER THE NEXT TWO HOURS. WITH TEMPERATURES HOVERING
SLIGHTLY BELOW THE FREEZING MARK...IT IS POSSIBLE THAT THERE COULD
BE SOME ICY PATCHES ON ROADS..BRIDGES..AND OVERPASSES DURING THE
MORNING COMMUTE. TEMPERATURES ARE EXPECTED TO RISE ABOVE FREEZING
BETWEEN 800 AND 900 AM. UNTIL THIS HAPPENS USE CAUTION WHEN DRIVING.

ABW