SPC MESOSCALE DISCUSSION 1338 FOR WRN PA...MUCH OF OH...CNTRL IND
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 011444Z - 011700Z

CONVECTIVE TRENDS ACROSS THE OHIO VALLEY ARE BEING MONITORED.  ONE
OR MORE SEVERE THUNDERSTORM WATCHES MAY BE NEEDED WITHIN THE NEXT
COUPLE OF HOURS.

PRE-FRONTAL SQUALL LINE IS INCREASING IN AREAL COVERAGE AND
INTENSIFYING ACROSS THE EASTERN GREAT LAKES AND OHIO VALLEY.  GIVEN
WEAK CAP/RAPID DESTABILIZATION ASSOCIATED WITH SURFACE HEATING/AND
STRENGTHENING LOW-LEVEL CONVERGENCE...THIS TREND IS LIKELY TO
CONTINUE INTO THE EARLY AFTERNOON HOURS FROM AREAS NORTH AND WEST
OF PITTSBURGH PA...WESTWARD TOWARD THE INDIANAPOLIS IND AREA. 
STEADY INCREASE IN STRENGTH OF MEAN FLOW...ASSOCIATED WITH JET
STREAK IN BASE OF SHORT WAVE TROUGH DIGGING ACROSS THE GREAT LAKES
REGION...WILL SUPPORT ACCELERATING SOUTHEASTWARD STORM MOTION AND
INCREASING THREAT FOR DAMAGING WINDS...PARTICULARLY FROM EASTERN
OHIO AND WESTERN PENNSYLVANIA SOUTHEASTWARD TOWARD THE CENTRAL
APPALACHIANS.

IN RESPONSE TO HEIGHT RISES ACROSS THE UPPER MISSISSIPPI VALLEY...
TAIL END OF SQUALL LINE OVER PARTS OF CENTRAL INDIANA WILL BE SLOW
MOVING/QUASI-STATIONARY...BUT STRENGTHENING VERTICAL SHEAR PROFILES
WILL STILL SUPPORT AT LEAST A THREAT OF LARGE HAIL AFTER 18Z.

..KERR.. 07/01/01