

132 

WWUS20 KWNS 080001

SEL4

SPC WW 080001

INZ000-MIZ000-LMZ000-080700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 4

NWS STORM PREDICTION CENTER NORMAN OK

555 PM CST MON JAN 7 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHERN AND WESTERN INDIANA

       WESTERN AND SOUTHERN LOWER MICHIGAN

       LAKE MICHIGAN



EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 555 PM

UNTIL 100 AM CST.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES SOUTH OF VALPARAISO

INDIANA TO 55 MILES NORTH NORTHEAST OF GRAND RAPIDS MICHIGAN.

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 1...WW 2...WW 3...



DISCUSSION...TSTMS IN NRN IL HAVE EVOLVED INTO LEWP-BEARING

MCS...WITH ONE LEWP CREST NOW NEAR CHI AND ANOTHER S OF MMO.  GIVEN

EXISTING SFC-BASED INSTABILITY AND STRONG LOW TO MID LEVEL WSWLY

WIND FIELD...EXPECT THESE FEATURES WILL CONTINUE ENE AT APPROX. 50

KTS AND POSE A THREAT FOR DAMAGING WIND AND POSSIBLY BOW-APEX

TORNADOES.  FARTHER N... STORMS CONTINUE TO FORM ATTM IN PLUME OF

SLIGHTLY ELEVATED INSTABILITY EXTENDING ENE FROM FAR NRN IL/SE WI.

GIVEN STRENGTH OF DOWNSTREAM WIND FIELD AND LIKELIHOOD THAT

LAKE-INDUCED STABILIZATION WILL BE LIMITED...A THREAT MAY DEVELOP

FOR ISOLATED DAMAGING WIND/HAIL AND/OR A TORNADO OVER PARTS OF

WRN/CNTRL LWR MI.



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

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 350.

MEAN STORM MOTION VECTOR 25050.





...CORFIDI

