MESOSCALE DISCUSSION 2614 NWS STORM PREDICTION CENTER NORMAN OK 0556 PM CST SUN DEC 14 2003 AREAS AFFECTED...UPSTATE NEW YORK...VT/NH AND MUCH OF WRN/NRN ME CONCERNING...HEAVY SNOW VALID 142356Z - 150600Z VERY HEAVY SNOWFALL WITH HOURLY RATES IN EXCESS OF 2 INCHES ARE ANTICIPATED TO AFFECT A 50-100 MILE WIDE BAND FROM THE MOHAWK VALLEY OF NY NEWD INTO NRN/CENTRAL VT/NRN NH/NWRN ME OVER THE NEXT 3-6 HOURS. SNOWFALL WILL LIKELY DIMINISH IN INTENSITY OVER PORTIONS OF SERN NY/SRN VT/SRN NH DURING THE SAME TIME PERIOD. ADDITIONALLY...THE ONSET OF HEAVY SNOWFALL WILL MOVE FROM SW-NE ACROSS MUCH OF WRN AND INTO CENTRAL ME OVER THE NEXT FEW HOURS...WITH HOURLY ACCUMULATION RATES UP TO 1 INCH FOR A SEVERAL HOUR PERIOD. RECENT TRENDS IN IR SATELLITE IMAGERY SUGGESTED MID LEVEL VERTICAL MOTION HAS INCREASED OVER CENTRAL NY AHEAD OF A DEEPENING VORTICITY CENTER OVER NRN PA. THE STRONGEST VERTICAL MOTION IN THE 600-500 MB LAYER...OWING IN PART TO FRONTOGENESIS AND COINCIDENT WITH THE MOST FAVORABLE DENDRITIC SNOW GROWTH PROFILE...WILL OCCUR ALONG AN AXIS FROM THE MOHAWK VALLEY NEWD INTO THE CHAMPAIGN RIVER VALLEY OF NERN NY/NRN/CENTRAL VT...AND INTO NRN NH. HOURLY ACCUMULATION RATES AROUND 2 INCHES WILL BE POSSIBLE IN THIS REGION BEGINNING IN THE NEXT FEW HOURS...AS CONTINUED STRONG LOW LEVEL MOISTURE ADVECTION ALLOWS FOR INCREASING PRECIPITABLE WATER VALUES/HIGHER PRECIPITATION EFFICIENCY. ALTHOUGH A COUPLE OF MID LEVEL DRY SLOTS HAVE DEVELOPED OVER THE LAST FEW HOURS ACROSS NJ INTO SERN NY AND OVER CENTRAL PA...WHICH MAY LIMIT THE SNOWFALL RATES OVER THE HUDSON RIVER VALLEY OF SERN NY...SRN VT/NH DURING THE NEXT FEW HOURS...A SECONDARY VORT CENTER OVER MD IN ASSOCIATION WITH THE MAIN UPPER LOW...SHOULD PROVIDE FOR INCREASING SNOWFALL RATES ACROSS THIS AREA LATER THIS EVENING. ADDITIONALLY...THE ONSET OF HEAVY SNOW COINCIDENT WITH A REGION OF STRONG MID LEVEL FRONTOGENESIS OVER ERN NH/NERN VT WILL PUSH ACROSS WRN ME DURING THE NEXT FEW HOURS. ALTHOUGH DRY LOW LEVELS WILL MITIGATE THE TOTAL SNOWFALL AMOUNTS WITH THIS INITIAL BAND OF HEAVY SNOW...A SEVERAL HOUR PERIOD OF AROUND 1 INCH/HR SNOWFALL RATES ARE STILL ANTICIPATED...ESPECIALLY GIVEN THE HIGH SNOW- LIQUID WATER EQUIVALENT RATIOS WITH SFC TEMPERATURES IN THE TEENS. ..CROSBIE.. 12/14/2003 ATTN...WFO...GYX...BOX...BTV...ALY...BGM...BUF... 44987400 43947608 42327569 42377390 43907014 45106968
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