

000 

WWUS20 KWNS 180438

SEL7

SPC WW 180438

ILZ000-MOZ000-181100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 717

NWS STORM PREDICTION CENTER NORMAN OK

1140 PM CDT WED OCT 17 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN ILLINOIS

       CENTRAL AND EASTERN MISSOURI



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1140 PM

UNTIL 600 AM CDT.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

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

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH NORTHWEST OF

ALTON ILLINOIS TO 35 MILES EAST SOUTHEAST OF WEST PLAINS

MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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...THIS TORNADO WATCH REPLACES TORNADO

WATCH NUMBER 714. WATCH NUMBER 714 WILL NOT BE IN EFFECT AFTER

1140 PM CDT. CONTINUE...WW 713...WW 715...WW 716...



DISCUSSION...LINE OF STRONG TO SEVERE STORMS WILL CONTINUE TO TRACK

EASTWARD ACROSS MO AND INTO WESTERN IL DURING THE OVERNIGHT PERIOD.

VERY STRONG VERTICAL SHEAR PROFILES COMBINED WITH SUFFICIENT

INSTABILITY MAY MAINTAIN A RISK OF ISOLATED TORNADOES...AS WELL AS

DAMAGING WINDS AND HAIL.



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

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

500. MEAN STORM MOTION VECTOR 24035.





...HART

