MESOSCALE DISCUSSION 0069
   NWS STORM PREDICTION CENTER NORMAN OK
   0328 AM CST TUE FEB 03 2004
   
   AREAS AFFECTED...WRN PA...WV PNHDL...WRN/NRN VA...AND WRN/CNTRL MD
   
   CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 
   
   VALID 030928Z - 031230Z
   
   PRECIPITATION CHANGEOVER TO HEAVY SNOW...AT RATES IN EXCESS OF AN
   INCH PER HOUR...APPEARS LIKELY ACROSS WESTERN PENNSYLVANIA WITHIN
   NEXT COUPLE OF HOURS.  MEANWHILE FREEZING RAIN AT RATES UP TO A
   TENTH OF AN INCH PER HOUR WILL CONTINUE/DEVELOP FROM NORTHWESTERN
   VIRGINIA INTO SOUTH CENTRAL PENNSYLVANIA.
   
   PRECIPITATION SHIELD IN ZONE OF ENHANCED ISENTROPIC ASCENT ALONG
   SOUTHERLY LOW-LEVEL JET AXIS CONTINUES TO SHIFT SLOWLY EASTWARD INTO
   THE UPPER OHIO VALLEY/CENTRAL APPALACHIANS REGION.  BY 12Z...
   LOW-LEVEL JET AXIS APPEARS LIKELY TO EXTEND FROM NORTH CENTRAL NORTH
   CAROLINA THROUGH CENTRAL VIRGINIA AND WESTERN PENNSYLVANIA....WITH
   LOWER LEVELS WARMING ABOVE FREEZING TO SOUTHEAST OF CREST OF
   APPALACHIANS.  SHALLOW LAYER OF SUBFREEZING SURFACE TEMPERATURES
   WILL PERSIST... HOWEVER...IN A NARROW CORRIDOR IN THE IMMEDIATE LEE
   OF THE APPALACHIANS.  THIS WILL LIKELY RESULT IN PERIOD OF MODERATE
   FREEZING RAIN AND SIGNIFICANT ICING ROUGHLY ALONG AND WEST OF A
   LYNCHBURG/ CHARLOTTESVILLE/ FREDERICK LINE THROUGH MID MORNING.
   
   PRECIPITATION RATES WILL BE ENHANCED BY MID-LEVEL FORCING AHEAD OF
   SHORT WAVE TROUGH LIFTING OUT OF THE LOWER OHIO VALLEY...WHICH WILL
   BECOME FOCUSED FROM NORTHWESTERN VIRGINIA INTO WESTERN PENNSYLVANIA
   BY DAYBREAK...THEN CONTINUE TO SPREAD NORTHEASTWARD.  MODELS ALL
   SUGGEST STRONG DEEP LAYER LIFT WILL CONTRIBUTE TO SUFFICIENT
   LOWER/MID TROPOSPHERIC COOLING FOR CHANGEOVER TO ALL SNOW
   ALONG/NORTH OF CREST OF APPALACHIANS ACROSS WESTERN PENNSYLVANIA
   BY/SHORTLY AFTER 12Z.  CHANGEOVER MAY OCCUR EARLIER AROUND
   PITTSBURGH...BUT HEAVIEST SNOW FALL BY MID DAY APPEARS LIKELY IN
   SWATH SOUTHEAST OF PITTSBURGH INTO AREAS NEAR/SOUTH AND WEST OF
   BINGHAMTON NY.
   
   ..KERR.. 02/03/2004
   
   
   ATTN...WFO...BGM...AKQ...BUF...CTP...LWX...RNK...PBZ...RLX...
   
   40498024 41277986 41907855 42047779 42217668 41707628
   41037626 40507707 39027749 37597851 37297969 38258019
   39277976 39828008