MESOSCALE DISCUSSION 0056
   NWS STORM PREDICTION CENTER NORMAN OK
   0332 AM CST MON JAN 28 2013
   
   AREAS AFFECTED...FAR SWRN NY AND PARTS OF NWRN PA
   
   CONCERNING...FREEZING RAIN 
   
   VALID 280932Z - 281430Z
   
   SUMMARY...ONGOING LIGHT SNOW...POSSIBLY MIXED WITH SLEET...IS
   EXPECTED TO CHANGE TO FREEZING RAIN BY 12Z ACROSS PART OF NWRN PA
   INTO FAR SWRN NY. THIS DISCUSSION AREA IS GENERALLY 40-60 MILES WIDE
   AND EXTENDS NNWWD FROM CLEARFIELD COUNTY PA TO FAR ERN LAKE ERIE.
   FREEZING RAIN RATES SHOULD RANGE FROM 0.03-0.06 INCH PER HOUR...WITH
   THE PA PORTION OF THIS REGION HAVING A PROLONGED FREEZING RAIN EVENT
   THROUGH 15Z...WHILE THE NY PORTION CHANGES TO RAIN BETWEEN 12-15Z AS
   SURFACE TEMPERATURES RISE ABOVE 32 F.
   
   DISCUSSION...SIMILAR TO PRECIPITATION-TYPE TRENDS NOTED UPSTREAM
   ACROSS ERN OH INTO FAR WRN PA INCLUDING THE PITTSBURGH METRO
   AREA...ONGOING LIGHT SNOW ACROSS THE DISCUSSION AREA PER LATEST
   SURFACE OBSERVATIONS ARE EXPECTED TO CHANGE TO FREEZING RAIN BY 12Z.
   REGIONAL RADAR IMAGERY SHOWED PRECIPITATION CONTINUING TO ADVANCE
   EWD EARLY THIS MORNING ACROSS MUCH OF THE WRN HALF OF PA...AND
   BEGINNING TO AFFECT FAR SWRN NY AS THE INITIAL DRY SUB-CLOUD LAYER
   PER 00Z PIT/BUF SOUNDINGS MOISTENS. SURFACE TEMPERATURES MAY
   CONTINUE TO RISE SOME DUE TO ONGOING WAA...BUT FORECAST SOUNDINGS
   SUGGEST WET-BULB EFFECTS WILL HELP TO KEEP THESE TEMPERATURES IN THE
   UPPER 20S TO JUST BELOW FREEZING. 
   
   SINCE 05Z...LOW LEVEL WINDS PER WSR-88D VWPS ACROSS ERN OH INTO WRN
   PA HAVE VEERED TO WLY AND STRENGTHENED TO 40-50 KT. MODELS SUGGEST A
   FURTHER INCREASE OF THE LLJ CAN BE EXPECTED INTO THE MORNING ACROSS
   WRN PA/SWRN NY TRANSPORTING A PRONOUNCED WARM NOSE /+4 TO +7 C/ 850
   MB TEMPERATURES ATOP THE SUB-FREEZING SURFACE TEMPERATURES.  AS
   SUCH...THIS WILL RESULT IN AN EXTENDED PERIOD OF FREEZING RAIN
   ACROSS PRIMARILY THE PA PORTION OF THE DISCUSSION AREA THROUGH 15Z.
   
   ..PETERS.. 01/28/2013
   
   
   ATTN...WFO...BUF...CTP...PBZ...CLE...
   
   LAT...LON   42817889 42387840 41487825 40887841 40927879 41597913
               41837969 42327966 42887936 42817889