

203 

WWUS20 KWNS 200430

SEL0

SPC WW 200430

ARZ000-ILZ000-MOZ000-201300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 720

NWS STORM PREDICTION CENTER NORMAN OK

1130 PM CDT WED AUG 19 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTH CENTRAL ARKANSAS

       SOUTHWEST ILLINOIS

       CENTRAL...EAST CENTRAL...AND SOUTHEAST MISSOURI



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1130 PM

UNTIL 800 AM CDT.



HAIL TO 1.5 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 75

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH

SOUTHEAST OF MOUNT VERNON ILLINOIS TO 65 MILES WEST SOUTHWEST OF

FORT LEONARD WOOD MISSOURI.  FOR A COMPLETE DEPICTION OF THE

WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 717...WW 718...WW 719...



DISCUSSION...SW MO FORWARD-PROPAGATING MCS EXPECTED TO CONTINUE

MAINLY E OR SLIGHTLY N OF E...WITH LCLY DMG WIND AND WITH ADDITIONAL

DEVELOPMENT POSSIBLE ON ITS NRN END.  ASSOCIATED STORMS MAY INCREASE

SOMEWHAT AS SYSTEM ENCOUNTERS MORE MOIST BOUNDARY LAYER UPON

APPROACHING THE MS RVR VALLEY.  OTHER STORMS MAY FORM/REDEVELOP INTO

WRN PART OF WW AS COLD FRONT NOW IN ERN KS INTERACTS WITH ELEVATED

POST-MCS STORMS NOW IN SE KS.  THE RESULTING STORM CLUSTER SHOULD

ALSO MOVE E...OR PERHAPS A BIT S OF EAST...WITH A THREAT FOR SVR

HAIL.



AVIATION...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 26030.





...CORFIDI

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