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633 

WWUS20 KWNS 072315

SEL0

SPC WW 072315

ILZ000-INZ000-MOZ000-080700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 260

NWS STORM PREDICTION CENTER NORMAN OK

615 PM CDT THU MAY 7 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND SOUTHERN ILLINOIS

       WESTERN INDIANA

       NORTHEAST MISSOURI



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 615 PM

UNTIL 200 AM 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 60 MILES WEST

SOUTHWEST OF QUINCY ILLINOIS TO 45 MILES SOUTH SOUTHEAST OF TERRE

HAUTE INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 258...WW 259...



DISCUSSION...TSTMS EXPECTED TO INCREASE THROUGH LATE EVE ALONG /1/

W-E BOUNDARY OVER NE MO/W CNTRL IL...AND /2/ INVOF DIFFUSE WARM

FRONTAL SEGMENT ORIENTED MORE N-S ACROSS CNTRL MO.  PROXIMITY TO

STRONG ZONAL MID/UPR LVL FLOW AND SIZABLE TEMPERATURE-DEW POINT

SPREADS SUGGEST POTENTIAL FOR BOWING SEGMENTS WITH SVR WIND/HAIL AS

STORMS MERGE INTO A FORWARD-PROPAGATING MCS.



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 29035.





...CORFIDI

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