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000 

WWUS20 KWNS 220215

SEL1

SPC WW 220215

ILZ000-INZ000-MOZ000-220800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 721

NWS STORM PREDICTION CENTER NORMAN OK

915 PM CDT MON JUL 21 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN ILLINOIS

       SOUTHWEST INDIANA

       CENTRAL AND EASTERN MISSOURI



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 915 PM UNTIL

300 AM CDT.



HAIL TO 2.5 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST OF

COLUMBIA MISSOURI TO 50 MILES NORTHEAST OF EVANSVILLE INDIANA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 719...WW 720...



DISCUSSION...LINEAR MCS WILL CONTINUE TO SAG SSEWD ACROSS THIS

REGION TONIGHT AND FEED OF A VERY UNSTABLE AIR MASS IN PLACE

REPRESENTED BY MLCAPE IN EXCESS OF 4000 J/KG AT MID EVENING.

COMBINED WITH 30-40 KT DEEP LAYER SHEAR...THIS WILL PROVE MORE THAN

ADEQUATE FOR THREATS OF LARGE HAIL AND DAMAGING WINDS.  ORGANIZATION

INTO ONE OR MORE BOWING MCSS ALSO REMAINS POSSIBLE LATE THIS

EVENING.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 34025.





...EVANS

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