MESOSCALE DISCUSSION 0026
   NWS STORM PREDICTION CENTER NORMAN OK
   0508 AM CST WED JAN 07 2009
   
   AREAS AFFECTED...PARTS OF NE PA...NRN NJ...SE NY THRU MUCH OF SRN
   NEW ENGLAND
   
   CONCERNING...FREEZING RAIN 
   
   VALID 071108Z - 071415Z
   
   STEADY MODERATE FREEZING RAIN IS EXPECTED TO DEVELOP ACROSS THE
   REGION...LIKELY LEADING TO SIGNIFICANT ICING THIS MORNING.
   
   A MID-LEVEL SHORT WAVE IMPULSE...EMANATING FROM THE BASE OF THE
   LARGE-SCALE TROUGH OVER THE MISSISSIPPI VALLEY...IS NOW RAPIDLY
   LIFTING NORTHEASTWARD THROUGH THE SOUTHERN/CENTRAL APPALACHIANS.  AS
   THIS MOTION CONTINUES...A STRONG DOWNSTREAM LOWER/MID TROPOSPHERIC
   WARM ADVECTION REGIME APPEARS LIKELY TO BECOME FOCUSED IN A BELT
   FROM THE LEE OF THE NORTH CENTRAL APPALACHIANS THROUGH THE LOWER
   HUDSON VALLEY AND MUCH OF SOUTHERN NEW ENGLAND BY THE 13-15Z TIME
   FRAME.  WITHIN AN ALREADY SATURATED ENVIRONMENT...ASSOCIATED FORCING
   FOR UPWARD VERTICAL MOTION IS EXPECTED TO INTENSIFY
   PRECIPITATION...MUCH OF WHICH WILL BE IN THE FORM OF RAIN.
   
   DESPITE CONTINUED DEEPENING OF THE PRIMARY SURFACE CYCLONE OVER THE
   LOWER GREAT LAKES...A SECONDARY SURFACE LOW ALREADY APPEARS TO BE
   DEVELOPING OFF NORTHERN MID ATLANTIC COASTAL AREAS.  AND...
   SUB-FREEZING BOUNDARY LAYER AIR SEEMS LIKELY TO REMAIN ENTRENCHED
   ACROSS THE POCONOS...CATSKILLS...LOWER HUDSON VALLEY /MOSTLY
   NORTHWEST THROUGH NORTH OF THE NEW YORK METROPOLITAN AREA/...AND
   MUCH OF SOUTHERN NEW ENGLAND INLAND OF COASTAL AREAS.  THIS PROBABLY
   WILL ALLOW FOR A THICK COATING OF ICE ON THE ORDER OF 1/4 TO 1/2+ ON
   MOST EXPOSED OBJECTS/SURFACES...AS RAIN RATES AVERAGE NEAR OR IN
   EXCESS OF .10 INCH PER HOUR THROUGH MUCH OF THE MORNING HOURS.
   
   WARMING ALOFT IS EXPECTED TO BECOME SUFFICIENT TO SUPPORT A
   CHANGEOVER FROM A LIGHT WINTRY MIX TO LIGHT TO MODERATE FREEZING
   RAIN NORTHWARD INTO AREAS NEAR/NORTH OF ALBANY...SOUTHERN VERMONT
   AND NEW HAMPSHIRE BY 15-18Z.
   
   ..KERR.. 01/07/2009
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
   SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
   TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
   FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.
   
   ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...
   
   LAT...LON   41707616 42367563 42737521 43137469 43067366 43167263
               43367099 41877058 41367239 40667407 40777523 40937583
               41407606 41707616