

337 

WWUS20 KWNS 200449

SEL4

SPC WW 200449

INZ000-KYZ000-OHZ000-WVZ000-201100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 484

NWS STORM PREDICTION CENTER NORMAN OK

1250 AM EDT SAT JUN 20 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST INDIANA

       NORTHERN KENTUCKY

       SOUTHERN HALF OF OHIO

       CENTRAL AND NORTHWEST WEST VIRGINIA



EFFECTIVE THIS SATURDAY MORNING FROM 1250 AM UNTIL 700 AM 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES WEST OF

CINCINNATI OHIO TO 55 MILES EAST SOUTHEAST OF PARKERSBURG WEST

VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 483...



DISCUSSION...EARLIER CONVECTION WEAKENED ACROSS SE INDIANA...BUT A

NEW CONVECTIVE LINE IS EVOLVING FARTHER TO THE W.  THIS CONVECTION

APPEARS TO BE MORE CLOSELY PHASED WITH MID LEVEL JET ASSOCIATED WITH

THE SHORTWAVE TROUGH PASSING JUST N OF THE WATCH AREA...AND RECENT

RADAR IMAGERY SUGGESTS AN ACCELERATED EWD MOTION OF 45-55 KT.  GIVEN

THE PRESENCE OF LINGERING MODERATE INSTABILITY IN THE WARM SECTOR

AND INCREASING LOW-MID LEVEL FLOW WITH TIME FROM THE W...THERE WILL

BE THE POTENTIAL FOR A CORRIDOR OF DAMAGING WINDS OVERNIGHT FROM SE

INDIANA ALONG THE OH RIVER INTO WV.



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 27045.





...THOMPSON

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