[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 061149
SWOMCD
SPC MCD 061148 
NYZ000-PAZ000-061745-

MESOSCALE DISCUSSION 2501
NWS STORM PREDICTION CENTER NORMAN OK
0548 AM CST MON DEC 06 2004

AREAS AFFECTED...PORTIONS OF WRN /CENTRAL NY AND NCENTRAL PA

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 061148Z - 061745Z

MODERATE SNOW WILL DEVELOP ACROSS PORTIONS OF WRN/CENTRAL NY THROUGH
18Z...WITH A MIX OF FREEZING RAIN/SLEET THE PREDOMINANT PTYPES
ACROSS NCENTRAL PA. SNOW SHOULD CHANGE OVER TO FREEZING RAIN/SLEET
NWD INTO SCENTRAL/SWRN NY AND PORTIONS OF NERN PA BETWEEN 15-18Z.
HOURLY ACCUMULATIONS AROUND 0.03-0.05 INCH LIQUID EQUIVALENT IS
ANTICIPATED TO BE COMMON ACROSS THE AREA FOR AT LEAST A 2-4 HR
PERIOD.

REGIONAL RADAR IMAGERY INDICATES THAT LIGHT PRECIPITATION CONTINUES
TO SPREAD RAPIDLY ENEWD ACROSS ERN MI AND NERN OH. 11Z SFC ANALYSIS
SHOWS THE SFC FREEZING LINE EXTENDING ACROSS FAR SWRN NY SEWD TO
NEAR STATE COLLEGE...WITH THE WET BULB FREEZING LINE ABOUT 50 MILES
SOUTH OF THIS AXIS. A COMBINATION OF MODERATE WARM ADVECTION IN THE
1-3 KM LAYER EVIDENT BY REGIONAL VWP/S OVER THE OHIO VALLEY AND EWD
MOVEMENT OF THE MID LEVEL FRONTOGENESIS FORCING OVER CENTRAL/ERN MI
WILL SUPPORT NEWD DEVELOPMENT OF LIGHT TO MODERATE PRECIPITATION
INTO THE AREA THROUGH THE MORNING HOURS. MODERATE SNOWFALL
ASSOCIATED WITH FRONTOGENETICALLY FORCED BANDS IN THE 600-700 MB
LAYER OVER CENTRAL MI WILL BEGIN TO MOVE INTO WRN NY BETWEEN 12-15Z.
FARTHER SOUTH...WHERE LOW LEVEL WAA WILL BE THE DOMINANT FORCING
MECHANISM...0-0.5 KM ENELY FLOW AND NUMEROUS NARROW VALLEY/S IN THE
REGION WILL SUPPORT COLD AIR BEING LOCKED IN WITH THE POTENTIAL FOR
FREEZING RAIN AND/OR SLEET AS ELEVATED WARM LAYER OVERSPREADS THE
AREA THROUGH THE MID-MORNING. THIS LOW LEVEL COLD DRAINAGE SHOULD
ALSO LIMIT THE NWD MOVEMENT OF THE FREEZING LINE THROUGH THE
MORNING. AS THE ELEVATED WARM LAYER GRADUALLY SHIFTS NWD THROUGH
DURING THE MID-LATE MORNING...SNOW OVER PORTIONS OF SWRN/SCENTRAL NY
AND NERN PA SHOULD THEN GRADUALLY BECOME MIXED WITH SLEET AND
POSSIBLY FREEZING RAIN BY 18Z.

..CROSBIE.. 12/06/2004

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 05-06 UTC...
11-12 UTC...17-18 UTC...AND 23-00 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28 TO ALLOW PARTNERS
AND USERS TO BETTER ANTICIPATE THE TIMING OF SPC WINTER WEATHER
MESOSCALE DISCUSSIONS.

ATTN...WFO...BGM...BUF...CTP...PBZ...

43317774 43217842 42397900 41787919 41297886 41157810
41077623 41507553 42137529 42757546 43337592 

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