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WWUS20 KWNS 301953

SEL9

SPC WW 301953

ILZ000-INZ000-310300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 119

NWS STORM PREDICTION CENTER NORMAN OK

255 PM CDT FRI MAR 30 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN ILLINOIS

       FAR SOUTHWEST INDIANA



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 255 PM UNTIL

1000 PM CDT.



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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES SOUTHEAST

OF MATTOON ILLINOIS TO 25 MILES WEST SOUTHWEST OF SCOTT AFB

ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 118...



DISCUSSION...TSTMS DEVELOPING ALONG COLD FRONT SHOULD CONTINUE TO

INTENSIFY THIS AFTERNOON WHILE INTERACTING WITH A MOIST AND

MODERATELY UNSTABLE WARM SECTOR WHERE SBCAPE HAS RISEN TO 1500-2500

J/KG.  LARGE-SCALE FORCING FOR ASCENT AND VERTICAL SHEAR MAY TEND TO

DIMINISH WITH TIME OWING TO THE EWD PROGRESSION OF MIDLEVEL IMPULSE

AWAY FROM THE REGION.  NONETHELESS...THE STEEP LOW TO MIDLEVEL LAPSE

RATES AND MODERATE INSTABILITY WILL SUPPORT A RISK FOR SEVERE HAIL

AND DAMAGING WINDS WITH THE STRONGEST STORMS.



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 25025.





...MEAD

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