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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 230

NWS STORM PREDICTION CENTER NORMAN OK

110 PM CDT THU MAY 3 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST ILLINOIS

       SOUTHEAST WISCONSIN

       LAKE MICHIGAN



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 110 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTH

SOUTHWEST OF MADISON WISCONSIN TO 70 MILES EAST SOUTHEAST OF

RACINE WISCONSIN.  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 229...



DISCUSSION...STORMS ARE INCREASING OVER SRN WI ALONG REMNANT OUTFLOW

BOUNDARY LEFT IN THE WAKE OF MCS NOT OVER NRN LOWER MI. ADDITIONAL

ACTIVITY IS EXPECTED TO FORM ALONG RESIDUAL OUTFLOW BOUNDARY FROM

NRN IL SWWD. WITH MLCAPE IN THE 1000-2000 J/KG RANGE AND EFFECTIVE

VERTICAL SHEAR ON THE ORDER OF 25-35 KT...SOME UPDRAFT

ORGANIZATION/PERSISTENCE IS LIKELY. GREATEST THREAT IN THE NEAR TERM

WILL BE SEVERE HAIL. HOWEVER...SOME UPSCALE GROWTH INTO LINE

SEGMENTS/CLUSTERS WILL BE  POSSIBLE IF STORM COVERAGE INCREASES

LATER THIS AFTERNOON AND THUS A DAMAGING WIND THREAT COULD EVOLVE

LATER TODAY.



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 28025.





...CARBIN

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