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WWUS20 KWNS 111042

SEL5

SPC WW 111042

ILZ000-INZ000-MIZ000-LMZ000-111700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 625

NWS STORM PREDICTION CENTER NORMAN OK

545 AM CDT MON JUL 11 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ILLINOIS

       NORTHERN INDIANA

       WESTERN AND SOUTHERN LOWER MICHIGAN

       LAKE MICHIGAN



EFFECTIVE THIS MONDAY MORNING FROM 545 AM UNTIL NOON CDT.



HAIL TO 1.5 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 120

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTHEAST OF

MARSEILLES ILLINOIS TO 25 MILES NORTH NORTHWEST OF ROBEN HOOD

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 624...



DISCUSSION...ERN IA BOW MCS EXPECTED TO CONTINUE GENERALLY E...WITH

FURTHER DEVELOPMENT POSSIBLE ALONG INTERSECTION OF THAT SYSTEM WITH

W-E OUTFLOW BOUNDARY LEFT BY MCS NOW ENTERING LK MI FROM WI.

DEEP...MODERATE TO STRONG UNIDIRECTIONAL WLY FLOW SAMPLED BY AREA

VWPS SHOULD SUPPORT ADDITIONAL BOWING LINE SEGMENTS ACROSS NRN

IL/SRN WI AS BAND OF ENHANCED FLOW SPREADS E IN TANDEM WITH PASSING

JET STREAK/UPR LOW IN WRN ONT.  AHEAD OF THE IA SYSTEM...LOW LVL AIR

MASS RECOVERY AND 925-850 MB THETA-E ADVECTION EWD INTO LWR MI/NRN

IND E OF THE LK MI MCS MAY SUPPORT A SEPARATE...MORE ISOLD DMGG WIND

THREAT THROUGH LATER THIS MORNING.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 28040.





...CORFIDI

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