[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 210102
SWOMCD
SPC MCD 210101 
NYZ000-PAZ000-MDZ000-210500-

MESOSCALE DISCUSSION 0181
NWS STORM PREDICTION CENTER NORMAN OK
0701 PM CST SUN FEB 20 2005

AREAS AFFECTED...CNTRL/ERN PA AND SW/SCNTRL NY

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 210101Z - 210500Z

MDT/LOCALLY HEAVY SNOW TO SPREAD EWD ACROSS SRN NY AND CNTRL/ERN PA
THIS EVENING...WITH ACCUMULATIONS OF 1.0-1.5 IN/HR POSSIBLE ON A
LOCALIZED BASIS. SNOW EXPECTED TO GRADUALLY CHANGE OVER TO
FZRA/SLEET ACROSS WCNTRL PA PRIOR TO 06Z.

SHORTWAVE TROUGH CURRENTLY SEEN IN WATER VAPOR IMAGERY ACROSS SRN
WI/NRN IL WILL CONTINUE TO TRACK EWD OVER LWR MI/SW ONTARIO TONIGHT.
AHEAD OF THIS FEATURE...WARM AIR ADVECTION/MOISTURE TRANSPORT REGIME
WILL CONTINUALLY SPREAD THROUGH THE OHIO VALLEY AND NRN/CNTRL
APPALACHIANS. SNOW ONGOING ACROSS MUCH OF SW NY AND NRN/CNTRL PA
EXPECTED TO INTENSITY THROUGH 03Z-06Z AS INCREASING UVVS COINCIDE
WITH FAVORABLE DENDRITIC LAYER. FURTHERMORE...MID LEVEL
FRONTOGENETICAL FORCING /600-800 MB/ COINCIDENT WITH WEAK POTENTIAL
INSTABILITY -- INCLUDING RECENT LIGHTNING STRIKES IN WCNTRL PA --
SUGGESTS A POTENTIAL FOR MESOSCALE ENHANCEMENT OF SNOW RATES WITH
EMBEDDED NW-SE ORIENTED BANDS. 00Z PIT RAOB FEATURED 6.9 C/KM MID
LEVEL LAPSE RATE.

ACROSS WCNTRL PA...ELEVATED 700-850 MB WARM LAYER SEEN IN 00Z PIT
RAOB WILL CONTINUE TO OVERSPREAD SHALLOW/BELOW 1 KM FREEZING LAYER.
ACCORDINGLY 18Z NAM/21Z RUC/09Z SREF CONSENSUS SUGGESTS SNOW WILL
LIKELY MIX WITH AND/OR CHANGE OVER TO FZRA/SLEET IN 03Z-06Z
TIMEFRAME WITHIN DUJ/PSB/AOO CORRIDOR.

..GUYER.. 02/21/2005

...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 00-01 UTC...
06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28.

ATTN...WFO...PHI...BGM...BUF...CTP...LWX...PBZ...CLE...

43297812 42677619 41937512 40597541 39867641 39717782
39877855 40777933 41287975 42057971 42597933 43067886 

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