MESOSCALE DISCUSSION 0138
   NWS STORM PREDICTION CENTER NORMAN OK
   0146 AM CST FRI FEB 25 2011
   
   AREAS AFFECTED...NRN OH...EXTREME SERN LOWER MI...NWRN/N-CNTRL
   PA...SWRN NY
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 250746Z - 251145Z
   
   PRECIPITATION WILL CONTINUE TO OVERSPREAD NRN OH...EXTREME SERN
   LOWER MI...NWRN/N-CNTRL PA...AND SWRN NY DURING THE OVERNIGHT HOURS
   AND INTO FRIDAY MORNING. THE PRECIPITATION WILL MAINLY BE
   SNOW...WITH RATES OF 1 TO 2 INCHES PER HOUR. HOWEVER...FREEZING RAIN
   WILL BE POSSIBLE ACROSS PORTIONS OF NERN OH AND NRN PA...WITH RATES
   OF 0.05 TO 0.10 INCH PER HOUR A CONCERN.
   
   AS COMPLEX LOW PRESSURE EVOLVES OVER THE OHIO VALLEY REGION...THE
   ASSOCIATED DEFORMATION ZONE WILL SHIFT NEWD ACROSS THE LOWER GREAT
   LAKES REGION. THE STRONG FRONTOGENETICAL CIRCULATION INVOF A
   LOW-LEVEL BAROCLINIC ZONE WILL FAVOR VIGOROUS LOW/MID-LEVEL ASCENT.
   ACCORDINGLY...SNOW WILL CONTINUE TO OVERSPREAD MUCH OF THE
   DISCUSSION AREA OVERNIGHT TONIGHT GIVEN SUBFREEZING TEMPERATURES
   THROUGHOUT THE TROPOSPHERE. THE PRESENCE OF SLANTWISE INSTABILITY
   PER THE 00Z RUN OF THE NAM WILL PROMOTE PRECIPITATION
   BANDING...WHERE RATES OF 1 TO 2 INCHES PER HOUR ARE ANTICIPATED.
   ACROSS NRN OH AND NWRN PA...RUC/NAM MODEL FORECAST SOUNDINGS
   HIGHLIGHT A NEARLY ISOTHERMAL PROFILE WITHIN THE 850-700-MB
   LAYER...FAVORING EFFICIENT SNOW AGGREGATION. 
   
   TEMPERATURES ALOFT ACROSS THE FAR SERN PART OF THE DISCUSSION AREA
   ARE FORECAST TO BE RELATIVELY WARMER AND POTENTIALLY LESS CONDUCIVE
   FOR SNOW GROWTH...WHILE SFC TEMPS REMAIN BELOW FREEZING. AS
   SUCH...FREEZING RAIN WITH RATES OF 0.05 TO 0.10 INCH PER HOUR WILL
   BE POSSIBLE IN THIS REGION.
   
   THE 04Z RUN OF THE EXPERIMENTAL HRRR INDICATES MOST OF THE HEAVIER
   PRECIP HAVING ENDED ACROSS NRN OH AND SERN MI BY 14Z FRIDAY...WHILE
   PERSISTING FARTHER NORTHEAST THROUGH FRIDAY MORNING.
   
   ..COHEN.. 02/25/2011
   
   
   ATTN...WFO...BGM...BUF...CTP...PBZ...CLE...ILN...DTX...IWX...
   
   LAT...LON   43367676 43387892 42718121 41968371 41178461 40208421
               40668159 41197991 41347753 41607645 42047594 42817594
               43367676