MESOSCALE DISCUSSION 1313
   NWS STORM PREDICTION CENTER NORMAN OK
   1105 AM CDT THU JUN 17 2004
   
   AREAS AFFECTED...NW AND CNTRL PA
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 171605Z - 171800Z
   
   A THREAT FOR WIND DAMAGE WILL INCREASE OVER THE NEXT FEW HOURS AS
   CELLS DEVELOP AND MOVE EWD ACROSS NW AND CNTRL PA. A WW MAY BECOME
   NECESSARY BY EARLY AFTERNOON.
   
   SFC ANALYSIS CURRENTLY SHOWS A QUASI-STATIONARY FRONT ACROSS NEW
   YORK WITH A LOW NEAR LAKE ERIE. SOUTH OF THE BOUNDARY...SFC
   DEWPOINTS ARE IN THE LOWER TO MID 70S F WHERE MLCAPE IS
   INCREASING...CURRENTLY RANGING FROM 1000 TO 1500 J/KG. AN AXIS OF
   LOW-LEVEL CONVERGENCE IS LOCATED IN NRN OH EXTENDING ENEWD ACROSS
   LAKE ERIE AND LAKE ONTARIO WHERE SCATTERED THUNDERSTORMS HAVE
   DEVELOPED. STORM COVERAGE SHOULD GRADUALLY INCREASE AS A BAND OF PVA
   MOVES EWD ACROSS WRN PA EARLY THIS AFTERNOON. OBJECTIVE ANALYSIS
   SHOWS A LOW TO MID-LEVEL SPEED MAX LOCATED ACROSS OH AND NW PA AND
   THIS IS HELPING CREATE MODERATE DEEP LAYER SHEAR OF 30 TO 35 KT. AS
   THE INSTABILITY CONTINUES TO INCREASE THROUGH EARLY AFTERNOON...THE
   ENVIRONMENT WILL BECOME MORE FAVORABLE FOR MULTICELL SEVERE STORMS.
   STEEP LOW-LEVEL LAPSE RATES AND HIGH SFC MOISTURE CONTENT WILL FAVOR
   WIND DAMAGE AS THE PRIMARY THREAT.
   
   ..BROYLES.. 06/17/2004
   
   
   ATTN...WFO...BGM...CTP...PBZ...CLE...
   
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