Midwest Chasing

  
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.