

560 

WWUS20 KWNS 042213

SEL8

SPC WW 042213

INZ000-OHZ000-PAZ000-WVZ000-050600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 428

NWS STORM PREDICTION CENTER NORMAN OK

615 PM EDT SAT JUN 4 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL INDIANA

       OHIO

       SOUTHWEST PENNSYLVANIA

       NORTHERN WEST VIRGINIA



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 615 PM

UNTIL 200 AM EDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHWEST

OF TERRE HAUTE INDIANA TO 25 MILES NORTH NORTHEAST OF WHEELING

WEST VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 426...WW 427...



DISCUSSION...MULTIPLE TSTM CLUSTERS ARE EVOLVING ALONG W-E ORIENTED

FRONT EARLY THIS EVENING WITHIN A MODERATELY TO STRONGLY UNSTABLE

AIR MASS WITH MLCAPE OF 2000-3500 J/KG.  MODEST /20-30 KT/ WLY

MIDLEVEL FLOW OBSERVED OVER CNTRL IND INCREASES TO 30-40 KT FROM THE

NW ACROSS OH/WRN PA WHICH SHOULD SUPPORT FURTHER UPSCALE GROWTH INTO

MULTIPLE CONVECTIVE SYSTEMS WITH A RISK FOR DAMAGING WINDS AND HAIL.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 29030.





...MEAD

