MESOSCALE DISCUSSION 0079
   NWS STORM PREDICTION CENTER NORMAN OK
   1021 PM CST TUE FEB 01 2011
   
   AREAS AFFECTED...NERN NJ...SRN NY...LONG ISLAND INCLUDING NYC
   METRO...AND CT
   
   CONCERNING...FREEZING RAIN 
   
   VALID 020421Z - 021015Z
   
   FREEZING RAIN WITH RATES AROUND 0.05" TO 0.10" PER 3 HOURS WILL
   DEVELOP EWD FROM PA AND WRN NJ LATE THIS EVENING. ACROSS NRN
   PORTIONS OF THE MCD AREA WHERE TEMPERATURES ARE COLDER THROUGH MID
   LEVELS...SLEET MAY BE THE PREDOMINATE PRECIPITATION TYPE OR MIX WITH
   FREEZING RAIN.
   
   A STRONG 850-700 MB FRONTOGENETIC BAND AHEAD OF MID LEVEL LOW
   LOCATED NEAR THE CNTRL IL/IND STATE LINE AS OF 04Z WAS PARTLY
   RESPONSIBLE FOR STRONG VERTICAL MOTION THROUGH WARM CONVEYOR BELT
   ACROSS MUCH OF ERN OHIO AND MUCH OF PA. AS THIS SYSTEM CONTINUES TO
   TRACK E/NEWD TONIGHT...CONTINUED FORCING DUE TO INCREASING MID LEVEL
   JET AND VORTICITY MAX PROGRESSING THROUGH FLOW WILL HELP MAINTAIN
   PRECIP SHIELD EWD ACROSS NERN NJ INTO SRN NY...LONG ISLAND AND
   CT...AND WIDESPREAD FREEZING RAIN AND SLEET ARE EXPECTED. 02Z
   FORECAST RUC SOUNDINGS SHOW A COLDER SFC AND MID LEVEL COLUMN OF AIR
   /WARM NOSE LESS THAN 3 C/ UNTIL AFTER 12Z...THEREFORE SLEET OR A
   FREEZING RAIN/SLEET MIX MAY DOMINATE. FURTHER S...A WARM NOSE OF 3-5
   C SHOULD ALLOW THE PREDOMINATE PRECIP TYPE TO BE FREEZING RAIN AS
   FULL MELTING OCCURS WITHIN ELEVATED WARM LAYER. WHILE SOUNDINGS DID
   NOT APPEAR UNSTABLE...THE 00Z NAM INDICATED SOME WEAK SYMMETRIC
   INSTABILITY WHICH COULD LEAD TO BRIEF PERIODS OF HEAVIER DOWNPOURS
   WHERE RATES COULD BE HIGHER THAN THOSE MENTIONED ABOVE.
   
   ..STOPPKOTTE.. 02/02/2011
   
   
   ATTN...WFO...BOX...OKX...ALY...PHI...
   
   LAT...LON   41127489 41277473 41777410 41947369 42007329 42037279
               42007229 41947202 41747175 41537186 41247225 40987256
               40407341 40087426 40357459 40817485 41127489