Mid-Atlantic Storm on Thursday

[WindRunner]

This from the Sterling NWS office, pretty much says that the entire Baltimore/DC area will have mixed precip Wednesday night, Thursday, Thursday night, and into Friday. Much of southern and eastern PA and most of NJ are in a similar situation, but of course they can expect to see more snow/sleet in the mix. The chance for the mixed bag goes as far south as Richmond, so it seems the entire Mid-Atlantic region will be in for a fun end to the week.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
317 PM EST SUN DEC 11 2005

.SHORT TERM (TONIGHT-MON)...

GOES-8 VSBL SATL AND SFC OBS SHWNG BKN-OVC ACRSS CWA. MODEL RH
AND CLD COVER CONT TONIGHT AS LYR RH OF 80-90% CONT TO BLANKET THE
CWA. HAVE UNDERCUT GFS MOS GDNCE BY A COUPLE OF DEG BOTH TNGHT AND
MON. LEWISETTA ON THE LOWER TID POT G18-21KTS LAST 3 HOURS.

FOR MON...GFS HAS AN OPEN SFC WAVE OVR KENTUCKY AT 12Z...THEN MOVES
IT SE OVER NC PIEDMONT DURING THE AFT HOURS. WHILE BOTH GFS AND NAM
DOES NOT PROD PCPN ACRSS OUR CWA WITH THIS SYS...BOTH MDLS PROD CLDS
ESP ACRSS S TIER ZONES IN VA AND S MD. SO HAVE INCR SKY COVER ACRSS
MOST OF THE CWA FOR MON AND LWRD MAX TEMPS.

CNCRNG SN ADVSRY FOR WSTRN 5 ZONES...NAM GIVES 5 INCHES TOTAL SN
ACCUM THRU TUE 8AM. XPCTNG 1-2 INC ON GRND BY 12Z MON...WITH ADDTL
INCH ON MON AND MON NGHT.

&&

.MARINE...

HAVE DROPPED SCA FOR MON AFTER REVIEW OF 12Z/NAM/GFS. 12Z NAM
BUFR PROF AT NHK/BWI HAS SCA WINDS AT H85...BUT THOSE WINDS DO NOT
MIX DOWN TO THE SFC.

HAVE MENTIONED POSSIBLE SCA THU-FRI WITH STRONG SE ONSHORE FLOW
DUE TO DVLPG INVERTED COASTAL TROUGH.

&&

.AVIATION...

VFR COND THRU 24 HRS...WITH CIGS NOT BLO 040 XCPT MAYBE AT CHO
MON MRNG.

&&

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY...

MINOR UPSLOPE SNOW WILL BE ENDING MONDAY NGT AS RIDGING ENSUES. WILL
CARRY CHANCE POPS DURING THE EVENING. ARCTIC COLD FRONT DEPARTS MON
NGT AS WELL WITH STRONG CAA CARRYING INTO TUE. VERY COLD TEMPS ARE
EXPECTED TUE THROUGH WED MORNING WITH LOWS IN THE SINGLE DIGITS IN
SOME LOCATIONS. THIS IS REFLECTED WELL ON THE LATEST GFS MOS TEMPS
WHICH ARE USUALLY THE WAY TO GO FOR PERIODS 3-5...HOWEVER WE HAVE
UNDERCUT THOSE TEMPS BY A FEW EXTRA DEGS ESPECIALLY IN AREAS THAT
MAY STILL HAVE SOME SNOW COVER. STRONG WINDS OFF THE DECK SHOULD
KEEP TEMPS UP A BIT ON MON NGT...BUT TUE NGT WATCH OUT FOR THOSE
COLD TEMPS.

STRONG SRLY ADVECTION REGIME SHOULD BEGIN ON WED BUT PRECIP HOLDS
OFF TIL WED NGT AND MAINLY IN THE SOUTH. GFS SEEMS THE WAY TO GO
HERE WITH SOME RUN TO RUN CONSISTENCY NOTED. AS DISCUSSED ON THE
PREV MID SHIFT...WITH WEDGE IN PLACE AND SRLY FLOW WED NGT...MIXED
PRECIP ALMOST A CERTAINTY WITH ANYTHING THAT FORMS. FOR NOW WILL
HOLD POPS IN THE LOW CHANCE CATEGORY BUT WILL MENTION MIX OF
ZR/IP/SN. THEN ON THU...SHOULD SEE AS TRANSITION TO ALL RAIN IN THE
FAR SE WITH A HIGHER CHANCE OF POPS DUE TO THE POSSIBLE PERSISTENT
ONSHORE FLOW AND WARM ADVECTION OFF THE REL WARM WATER. MIXED PRECIP
WILL STILL BE POSSIBLE ON THU FOR MOST OF THE REMAINING AREA THOUGH.

GFSX MOS POPS ARE VERY HIGH FOR THE PERIOD WED NGT-FRI NGT. WE HAVE
BUMPED OUR POPS UP TO 50 ON THU AND ADDED SMALL CHANCE POPS ON FRI
AS WELL...AND WE'LL HOLD OFF ON ANYTHING ELSE TIL MORE CERTAINTY.

AFTER FRI MORE U/L TROUGHINESS DVLPS ACROSS THE EAST AND TEMPS WILL
DROP OFF ONCE AGAIN TO NEAR OR BLW NORMAL LVLS.