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WWUS20 KWNS 311816

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 543

NWS STORM PREDICTION CENTER NORMAN OK

115 PM CDT TUE JUL 31 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN ILLINOIS

       WESTERN AND SOUTHWESTERN INDIANA



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 115 PM UNTIL

700 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF

BLOOMINGTON ILLINOIS TO 45 MILES SOUTH SOUTHWEST OF BLOOMINGTON

INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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...ADDITIONAL TSTMS ARE EXPECTED TO DEVELOP THIS AFTERNOON

ACROSS EAST CENTRAL IL AND TRACK SOUTHEASTWARD AFFECTING ERN IL AND

WRN/SWRN IND.  THE COMBINATION OF STEEP LAPSE RATES...MODERATE

INSTABILITY AND EFFECTIVE BULK SHEAR OF 40-50 KT WILL SUPPORT

SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS.



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 35020.





...PETERS/CARBIN

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