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538 

WWUS20 KWNS 182028

SEL4

SPC WW 182028

INZ000-MIZ000-OHZ000-LEZ000-LHZ000-LMZ000-190400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 344

NWS STORM PREDICTION CENTER NORMAN OK

430 PM EDT FRI JUN 18 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN INDIANA

       LARGE PART OF SOUTHERN LOWER MICHIGAN

       SMALL PART OF NORTHWEST OHIO

       LAKE ERIE

       LAKE HURON

       LAKE MICHIGAN



EFFECTIVE THIS FRIDAY AFTERNOON FROM 430 PM UNTIL MIDNIGHT EDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTH OF

VALPARAISO INDIANA TO 30 MILES NORTH NORTHEAST OF MOUNT CLEMENS

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 342...WW 343...



DISCUSSION...WELL DEVELOPED FORWARD PROPAGATING MCS TRACKING EWD

ACROSS NRN IL/SRN WI.  WITH THE AIR MASS ACROSS THE WATCH BECOMING

INCREASINGLY UNSTABLE...CONDITIONS WILL REMAIN FAVORABLE FOR

WIDESPREAD DAMAGING WINDS TO PERSIST ASSOCIATED WITH THE MCS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 27040.





...HALES

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