FXUS61 KLWX 052348
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
648 PM EST SAT DEC 5 2009
.SYNOPSIS...
A LOW PRESSURE OVER THE NORTHERN GULF OF MEXICO WILL MOVE
NORTHEASTWARD UP THE EASTERN SEABOARD ON SATURDAY...AS COLDER AIR
FILTERS INTO THE MID ATLANTIC. HIGH PRESSURE WILL SETTLE IN OVER
THE AREA SUNDAY AND WILL BE CENTERED OVER THE REGION BY SUNDAY
EVENING. A WEAK DISTURBANCE WILL PASS NORTH OF THE AREA MONDAY EVENING.
THAT WILL BE FOLLOWED BY A LARGE STORM SYSTEM ON TUESDAY NIGHT AND
WEDNESDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
FURTHER CHOPPING OFF OF ADVISORY WAS DONE AS SNOW ENDS FROM WEST
TO EAST ACROSS THE NORTHWEST BURBS. PREV...
BANDING ASSOCIATED WITH SW/NE ORIENTED DEFORMATION ZONE ACROSS WRN
DC/BALTIMORE SUBURBS PRODUCING SNOWFALL RATES TO NEAR 1 INCH PER
HOUR. S/E OF THIS BAND...RAIN SNOW MIX WITH LITTLE ACCUMULATION.
FURTHER WEST 700MB DRYING RACING IN FROM THE SW KEEPING SNOWFALL
RATES LIGHT. TEMPS IN LOWER 30S MOST AREAS...JUST ABOVE FREEZING.
SNOW XPCD TO GRADUALLY DIMINISH WEST OF THE URBAN CORRIDOR BY 600
PM...WITH LINGERING PRECIPITATION ACROSS MD AND DC METRO THROUGH 800
PM. ADZYS WILL BE KEPT AS IS...XCPT AREA ALONG I-95 WILL BE HAVE AN
END TIME NOW OF 2Z INSTEAD OF 4Z. AFTER UPR SHRTWV PASSES THRU THIS
AFTN...LIFT WILL MOVE TO THE N/E AND SNOW WILL COME TO AN END FROM W
TO E DRNG THE EVE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 AM SUNDAY/...
SYSTEM WL QUICKLY EXIT THE MID ATLC RGN TNGT AND BE REPLACED BY
HIGH PRES. BLV THE EVE WL BEGIN W/ CLDY SKIES AND BY MRNG SKIES WL
BE SUNNY. PRES GRAD BTWN THE LOW/HIGH WL GIVE AREA A BRZY/WINDY
NGT ALONG W/ SUBFRZG TEMPS EVERYWHERE XCPT IMMEDIATELY ALONG THE
CHES BAY.
&&
.LONG TERM /SUNDAY THROUGH SATURDAY/...
SUNDAY WL LIVE UP TO ITS TITLE AS THERE WL BE ABUNDANT
SUNSHINE... ALTHO IT WL BE COOL GIVEN SNOW COVER AND FACT THAT SUN
WL BE USING ITS ENERGY TO MELT SNOW RATHER THAN WARM AIR. AVG
HIGHS AT THIS TIME OF YR ARE IN U40S. IN ERN HALF OF CWA TMRW WL
ONLY SEE HIGHS IN L40S...AND WRN HALF ONLY U30S. HIGHLANDS WL BE
LUCKY TO REACH M30S.
HIGH PRES RMNS OVR THE AREA SUN NGT. W/ GOOD RAD CONDS TEMPS WL AGN
BE SUBFRZG EVERYWHERE - MU TEENS IN HIGHLANDS TO L30S ALONG THE BAY.
UPR LVL SHORTWV TO MOVE N OF THE CWA MON NGT. CLDS WL BE ON THE
INCRS MON AFTN. GFS GDNC IS HINTING AT POPS ON MON BUT FOR NOW I'D
PREFER TO HOLD OFF AS ENERGY WL BE SO FAR TO THE N.
I'M GOING TO SKIP OVR MON NGT/TUE AND GO TO TUE NGT/WED. I AM
CONCERNED OVR THIS SYSTEM. WE'RE STILL 4 DAYS OUT...BUT FOR SECOND
DAY IN A ROW MDLS IMPLY A COMPLICATED OCCLUDED SYSTEM COMING OUT OF
UPPER MIDWEST LOW. I'M CONCERNED ABT THE PTNL FOR ICING TUE NGT/1ST
HALF OF WED IN NWRN VA/ERN WV/WRN MD. IN YRS PAST I'D JUST HV SAID
"CHC RA/SN" THIS FAR OUT...BUT MDLS HV IMPRVD SO MUCH THIS DECADE
THAT I FEEL COMFORTABLE W/ A FZRA/IP FCST. WARM FNT LKLY LOCATED IN
CENTRAL VA TUE NGT. WARM/MOIST AIR WL BE MOVG INTO THE AREA
ALOFT...BUT FEAR THAT COLD AIR WL RMN LOCKED AT THE SFC IN LEE OF
APLCHNS. THIS MRNG'S GFS PAINTS A SUB 1300M FM ROUGHLY RT 15 W INTO
THE MTNS ALL THE WAY TO AUGUSTA CNTY.
HIGH PRES LOOKS TO RETURN LATE IN THE WK.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
IFR TO CONT THRU AT LEAST MID EVE...THEN VSBYS/CIGS WL BE IMPRVG
TO MVFR W/ GUSTY NW WINDS...AND THEN VFR CONDS AFTR MDNGT AND
THEN PERSISTING THRU MON. NEXT SIGNIFICANT SYSTEM WL BE TUE NGT
AND WED.
&&
.MARINE...
SCA WINDS OVRNGT AND 1ST PART OF SUN. NEXT SIGNIFICANT SYSTEM WL BE
TUE NGT AND WED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
MDZ005>007-009>011-013-014-016.
VA...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ053-
054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ531>534-
538>541-543.
SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR ANZ530-537-542.
SMALL CRAFT ADVISORY UNTIL 2 AM EST SUNDAY FOR ANZ535-536.
&&
$$
PELOQUIN/SBK/WOODY!
