

000 

WWUS20 KWNS 242003

SEL8

SPC WW 242003

ILZ000-INZ000-MIZ000-OHZ000-LEZ000-LHZ000-250300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 648

NWS STORM PREDICTION CENTER NORMAN OK

405 PM EDT FRI AUG 24 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       A SMALL PART OF NORTHEASTERN ILLINOIS

       CENTRAL AND NORTHERN INDIANA

       SOUTH CENTRAL AND SOUTHEASTERN MICHIGAN

       NORTHWESTERN OHIO

       LAKE ERIE

       LAKE HURON



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 405 PM UNTIL

1100 PM EDT.



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 NORTH AND SOUTH OF A LINE FROM 35 MILES WEST

SOUTHWEST OF DANVILLE ILLINOIS TO 10 MILES EAST SOUTHEAST OF

MOUNT CLEMENS MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 647...



DISCUSSION...SEVERE THUNDERSTORMS EXPECTED TO INCREASE IN COVERAGE

ACROSS WW THIS AFTERNOON AND EVENING.  AIR MASS IS MODERATELY

UNSTABLE BUT STRONGLY SHEARED FOR THIS TIME OF YEAR.  BOTH

SUPERCELLS AND BOW ECHOES CAN BE EXPECTED...WITH ATTENDANT THREATS

OF LARGE HAIL AND DAMAGING WINDS.



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 25035.





...EVANS

