MESOSCALE DISCUSSION 2138
NWS STORM PREDICTION CENTER NORMAN OK
0526 PM CST SUN DEC 26 2010
AREAS AFFECTED...NRN NJ...SERN NY/WRN LONG ISLAND...SRN VT...SWRN
NH...WRN MA/CT
CONCERNING...HEAVY SNOW
VALID 262326Z - 270530Z
BAND OF HEAVY SNOW WITH RATES RANGING FROM 1-2 IN/HR IS FORECAST TO
SHIFT WWD OUT OF MA/CT THIS EVENING AND BECOME ALIGNED FROM NRN NJ
NWD ACROSS SERN NY AND THE HUDSON RIVER VALLEY INTO PORTIONS OF SRN
VT/SWRN NH. FREQUENT GUSTS NEAR 35 MPH WILL LEAD TO BLOWING SNOW
WITH VISIBILITY REDUCED TO A QUARTER MILE OR LESS.
SURFACE ANALYSIS AT 23Z SHOWED A SURFACE CYCLONE LOCATED SE OF LONG
ISLAND...WHICH CONTINUES TO DEEPEN...EVIDENT BY PRESSURE FALLS OF 3
MB/HR. NEEDLESS TO SAY...LARGE-SCALE ASCENT IS QUITE INTENSE...AND
HAS PROVIDED A FAVORABLE BACKGROUND ENVIRONMENT FOR HEAVY SNOWFALL
FROM THE MID ATLANTIC REGION NWD INTO PORTIONS OF SRN NEW ENGLAND
DURING THE AFTERNOON. SNOWFALL RATES ARE CURRENTLY MOST PRONOUNCED
NEAR THE JERSEY COAST N-NEWD INTO SRN NY...CT...AND MA...WHERE THE
EXIT REGION OF AN INTENSE E-NELY LOW-LEVEL JET /WITH WIND SPEEDS AOA
50 KT/ IS FOCUSING A ZONE OF STRONG CONVERGENCE AND FRONTOGENESIS.
DURING THE 00-06Z TIME PERIOD...THE LOW-LEVEL CYCLONE IS FORECAST TO
MOVE NWD TOWARD CAPE COD. THIS WILL CAUSE THE ZONE OF STRONGEST
MESOSCALE FORCING FOR ASCENT TO BECOME RE-ORIENTED ROUGHLY ALONG A
LINE FROM NRN NJ NWD ACROSS SERN NY AND THE HUDSON VALLEY INTO
PORTIONS OF SRN VT AND SWRN NH. BANDED HEAVY SNOWFALL WITH HRLY
RATES OF 1-2 INCHES WILL BE POSSIBLE OVER THESE AREAS. IN
ADDITION...STRONG GRADIENT WIND SPEEDS OVER THE LOWEST HALF KM AGL
WILL PROMOTE FREQUENT GUSTS NEAR 35 MPH...LEADING TO POSSIBLE
BLIZZARD CONDITIONS.
..GARNER.. 12/26/2010
ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...
LAT...LON 39807465 40617521 42277504 43157419 43567329 43617209
42747190 40747338 40007404 39807465
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