

691 

WWUS20 KWNS 091225

SEL1

SPC WW 091225

ILZ000-INZ000-KYZ000-MOZ000-TNZ000-091800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 111

NWS STORM PREDICTION CENTER NORMAN OK

725 AM CDT SAT APR 9 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR SOUTHEAST ILLINOIS

       SOUTHERN INDIANA

       WESTERN AND CENTRAL KENTUCKY

       FAR SOUTHEAST MISSOURI

       NORTHERN MIDDLE TENNESSEE



EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 725 AM UNTIL

100 PM CDT.



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 115

STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES SOUTH

SOUTHEAST OF CLARKSVILLE TENNESSEE TO 70 MILES NORTH NORTHWEST OF

LOUISVILLE KENTUCKY.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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...MCV OVER SRN IL WILL CONTINUE TO TRACK EWD THROUGH THE

OHIO VALLEY THROUGH THIS MORNING.  ENHANCED LOW-LEVEL SWLY FLOW IN

ADVANCE OF THIS FEATURE WILL BOOST WARM ADVECTION PROFILES AND

SUPPORT AN INCREASINGLY ORGANIZED MCS INVOF A STATIONARY FRONT.

WHILE LARGE HAIL WILL BE A THREAT EARLY THIS MORNING...AS THE

BOUNDARY LAYER CONTINUES TO HEAT...VERY STEEP LAPSE RATES AND

INCREASING DEEP WNW FLOW WILL BE FAVORABLE FOR BOW ECHOES GIVING

DAMAGING WINDS.



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 27040.





...RACY

