Hail in Pennsylvania, August 15, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
333 PM EDT THU AUG 15 2002

AFTERNOON CONVECTION SPARKED BY DIURNAL HEATING AND VORT MAX MOVING
THRU OHIO VALLEY. STORMS STILL EXPECTED TO INCREASE IN COVERAGE AS
EVENING WEARS ON WITH OUTSIDE CHANCE OF A SEVERE GUST OR TWO.  MAIN
THREAT WILL BE TRAINING CELLS WITH LOCALLY HEAVY RAINFALL OF 1 TO 2
INCHES OR MORE (PRECIPITABLE WATERS ARE APPROACHING 2.00)...BUT
GIVEN LOCATION OF DYNAMICS...EXPECT THIS THREAT MAINLY WEST OF OUR
COUNTRY WARNING FORECAST AREA TONIGHT.  MARGINAL WINDS FOR SEVERE
WEATHER OVERHEAD...20-30KT AT 500MB AND 30-40KT AT 300MB.

DIFFUSE BAROCLINIC ZONE WILL BE SLOW TO MOVE...BASICALLY STALLING
OVER THE REGION.  BASICALLY THE MAIN FORECAST PROBLEM WAS TRYING TO
PIN DOWN TIMING ON MOST LIKELY PERIODS OF SHOWERS AND
THUNDERSTORMS.  FRIDAY AND SATURDAYS ACTION WILL HAVE MAINLY A
DIURNAL MAXIMUM...OWING TO THE LACK OF DYNAMICS.  HOWEVER... LATE
SATURDAY NIGHT WE SHOULD SEE AN INCREASE OF CONVECTION OVER THE OHIO
VALLEY AND EASTERN GREAT LAKES AS A STRONG PUSH OF COOLER AIR
APPROACHES.  TIMING OF THIS FEATURE LOOKS FAVORABLE FOR POSSIBLE SVR
WEATHER OVR CENTRAL PA SUNDAY AFTERNOON.  THEN A COUPLE OF NICE DAYS
ON TAP FOR MON-TUE WITH LOWER HUMIDITY AND PLEASANT TEMPS.  SFC HIGH
PUSHES EASTWARD WEDNESDAY BRINGING A RETURN TO WARMER AND MORE HUMID
CONDITIONS...WITH THE NEXT CHANCE OF SHRA/TS ON THURSDAY AHEAD OF
THE NEXT APPROACHING FRONT.

WORK ZONES ALREADY SENT AS PHLWRKMIS.

.CTP...SPS (SEVERE WEATHER OUTLOOK) FOR SLIGHT RISK OF SVR TSRA
       THIS EVENING.

MCPHEE/DEVOIR