WWUS20 KWNS 092041
SEL7
SPC WW 092041
KYZ000-OHZ000-PAZ000-WVZ000-100200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 567
NWS STORM PREDICTION CENTER NORMAN OK
440 PM EDT THU AUG 9 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 

       EXTREME NORTHERN KENTUCKY
       SOUTHERN AND EASTERN OHIO
       EXTREME WESTERN PENNSYLVANIA
       EXTREME NORTHERN WEST VIRGINIA AND THE NORTHERN WEST VIRGINIA
PANHANDLE

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 440 PM UNTIL
1000 PM EDT.

HAIL TO 1.5 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 40
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 115 MILES WEST
SOUTHWEST OF ATHENS OHIO TO 10 MILES EAST NORTHEAST OF PITTSBURGH
PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).

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.

DISCUSSION...STORMS WILL LIKELY INCREASE IN COVERAGE ALONG A SURFACE
CONFLUENCE BAND ACROSS OH...IN ADVANCE OF A LEAD SHORTWAVE TROUGH
MOVING EWD FROM INDIANA TO OH.  SURFACE HEATING TO THE SE OF THE
CONFLUENCE BAND HAS BOOSTED MLCAPE TO NEAR 1500 J/KG...WHILE
EFFECTIVE BULK SHEAR IS BECOMING FAVORABLE FOR ORGANIZED MULTICELL
CLUSTERS AND MARGINAL SUPERCELL STRUCTURES.  DAMAGING WINDS AND
LARGE HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS FOR THE NEXT
FEW HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 27020.


...THOMPSON