[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 160648
SWOMCD
SPC MCD 160647 
MEZ000-MAZ000-NHZ000-RIZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-161215-

MESOSCALE DISCUSSION 2576
NWS STORM PREDICTION CENTER NORMAN OK
1247 AM CST FRI DEC 16 2005

AREAS AFFECTED...MUCH OF NEW ENGLAND/NRN APPALACHIANS

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 160647Z - 161215Z

A MIX OF FREEZING RAIN/SLEET AND SNOW WILL DEVELOP ACROSS MUCH OF
NEW ENGLAND OVERNIGHT. FREEZING RAIN WILL CHANGEOVER TO MODERATE TO
HEAVY SNOW /HRLY RATES UP TO 1 INCH/ ACROSS PORTIONS OF CENTRAL/NRN
PA INTO WRN/NRN NY...WITH FREEZING RAIN CHANGING OVER TO RAIN OVER
FAR NRN NJ/NERN PA...THE LOWER HUDSON RIVER VALLEY AND MUCH OF CT
THROUGH 12Z. HOURLY FREEING RAIN/SLEET RATES AROUND 0.10 INCH WILL
BE COMMON ACROSS PORTIONS OF THE MIDDLE HUDSON RIVER VALLEY OF
ECENTRAL NY AND WRN PORTIONS OF MA/FAR SRN VT/SRN NH...LEADING TO
THE POTENTIAL FOR SIGNIFICANT SLEET AND ICING IN THESE AREAS THROUGH
12Z. 

STRONG LOW LEVEL WAA WILL CONTINUE IN ADVANCE OF POTENT UPPER TROUGH
MOVING THROUGH THE OHIO VALLEY. AT THE SURFACE...THE TREND OF A
SLOWLY LIFTING SURFACE 32 DEG F LINE WILL CONTINUE OVERNIGHT AS A
SURFACE LOW PRESSURE CENTERED OVER NEAR BWI AT 05Z LIFTS TOWARDS NYC
BY 12Z. THEREFORE...NRN NJ...NERN PA...THE LOWER HUDSON RIVER VALLEY
AND MUCH OF CT WILL SEE A CHANGEOVER FROM FREEZING PRECIP TO RAIN
THROUGH 12Z. FURTHER NORTH...THE STRENGTH OF THE WAA AND GRADUAL
SHRINKING OF THE ELEVATED WARM LAYER DEPTH DUE TO ASCENT WILL
SUPPORT A MIX OF MODERATE TO OCCASIONALLY HEAVY FREEZING RAIN AND
SLEET ACROSS MUCH OF ECENTRAL/NERN NY...VT/NH AND MA THROUGH 12Z. 

FURTHER WEST...LOW LEVEL CAA WAS COMMENCING PER VWP DATA AT PBZ. IN
ADDITION...MID LEVEL FRONTOGENESIS WILL CONTINUE TO INTENSIFY IN THE
700-600 MB LAYER SUPPORTING DENDRITIC SNOW GROWTH. THESE TWO WILL
COMBINE TO AID IN A CHANGEOVER OF P-TYPE FROM FREEZING RAIN TO
MOD-HVY SNOW OVER NCENTRAL PA NWD INTO WRN/NRN NY...ESPECIALLY
DURING THE 08-12Z TIME FRAME.

..CROSBIE.. 12/16/2005

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

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...BUF...CTP...PBZ...

44387148 43317068 42237116 41737201 41157332 41117459
41077533 40937637 40587783 41147903 43077776 44837533
44907298 

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