[MCD] SWOMCD

Fri Dec 16 01:21:24 UTC 2005

ACUS11 KWNS 160118
SWOMCD
SPC MCD 160118 
CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-MDZ000-VAZ000-WVZ000-160545-

MESOSCALE DISCUSSION 2575
NWS STORM PREDICTION CENTER NORMAN OK
0718 PM CST THU DEC 15 2005

AREAS AFFECTED...SRN AND CNTRL NY/MUCH OF PA/WRN CT/NRN NJ/MD/FAR
NRN VA/WV PANHANDLE

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 160118Z - 160545Z

PRIMARILY FREEZING RAIN...WITH POTENTIAL FOR ICE
ACCUMULATIONS...WILL CONTINUE TO TRANSITION NEWD ACROSS CNTRL/ERN
PA...NRN NJ...INTO SRN/CNTRL NY AND WRN CT THIS EVENING. ACROSS WRN
PA/WRN NY...A CHANGE OVER TO ALL SNOW IS EXPECTED THIS
EVENING...WITH MDT/LOCALLY HEAVY SNOW DEVELOPING BY LATE
EVENING/OVERNIGHT. FURTHER SOUTH...INITIAL FREEZING RAIN SHOULD
CHANGE OVER TO RAIN ACROSS NRN VA/MUCH OF MD/SE PA/MOST OF NJ PRIOR
TO 06Z.

WITH BROAD NEGATIVE TILT TROUGH CENTERED OVER THE UPPER MISSISSIPPI
VALLEY...VORTICITY MAX AND STRONG MID/UPPER JET CONTINUES TO RACE
EWD TOWARD THE MID ATLANTIC/NORTHEAST STATES WITHIN BASE OF UPPER
TROUGH. ACCORDINGLY...BROAD/DEEP FORCING FOR ASCENT IS CONTRIBUTING
TO NEWD TRANSITION OF BROAD PRECIPITATION SHIELD INTO THE NORTHEAST
STATES.

AS SEEN IN THE 00Z WASHINGTON-DULLES RAOB...NWD EXTRAPOLATION OF
ELEVATED MELTING LAYER WILL REMAIN SUPPORTIVE OF FREEZING RAIN AS
PRIMARY PRECIP-TYPE ACROSS MUCH OF CNTRL/ERN PA AND NRN NJ INTO
SRN/CNTRL NY AND WRN CT MUCH OF THE EVENING...WHERE WEDGE OF SHALLOW
COLD AIR WILL BE MAINTAINED. SOME SLEET/SNOW WILL BE POSSIBLE AS
WELL.

FURTHER WEST...00Z PITTSBURG AND 00Z BUFFALO RAOBS FEATURE A 1-2C
WARM LAYER NEAR 850 MB...STILL AT LEAST MARGINALLY SUPPORTIVE OF
FREEZING RAIN/SOME SLEET. HOWEVER...WITH NOCTURNAL/DYNAMIC COOLING
AND EVENTUAL COLD ADVECTION...21Z RUC GUIDANCE SUGGESTS A GRADUAL
CHANGE OVER TO ALL SNOW SHOULD OCCUR ACROSS MUCH OF WRN PA/WRN NY BY
LATE EVENING...WITH MDT/LOCALLY HEAVY SNOW PREVALENT INTO THE
OVERNIGHT. SNOW RATES MAY REACH 1 IN/HR IN THESE AREAS BY 06Z.

..GUYER.. 12/16/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BOX...OKX...ALY...PHI...BGM...BUF...CTP...LWX...PBZ...RLX...CLE...

43007437 41607284 41177380 40127503 39637663 39227774
38567885 38737931 39677952 40097994 41568027 43177865
43397632 

WWWW