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000 

WWUS20 KWNS 182025

SEL4

SPC WW 182025

ILZ000-INZ000-MIZ000-LHZ000-LMZ000-190400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 724

NWS STORM PREDICTION CENTER NORMAN OK

325 PM CDT THU OCT 18 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PART OF SOUTHERN AND EASTERN ILLINOIS

       MUCH OF INDIANA

       MUCH OF LOWER MICHIGAN

       LAKE HURON

       LAKE MICHIGAN



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 325 PM UNTIL

1100 PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 90 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 95 STATUTE

MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHEAST OF

ALPENA MICHIGAN TO 40 MILES SOUTHEAST OF MOUNT VERNON ILLINOIS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 722...WW 723...



DISCUSSION...VERY STRONG WIND FIELDS ROTATING NEWD ACROSS MID MS

VALLEY INTO GREAT LAKES TO E OF DEEP LOW OVER MN.  AIR MASS NOW

MDTLY UNSTABLE AND WITH LITTLE REMAINING CINH.  STEEP LAPSE RATES

HAVE DEVELOPED IN THE MOIST AXIS WHICH WILL FURTHER ENHANCE WIND

DAMAGE POTENTIAL AS STORMS DEVELOP INTO LINES AND BOWS.

ADDITIONALLY SUPERCELLS WILL BE LIKELY WITH POTENTIAL FOR STRONG

TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 80 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 22045.





...HALES

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