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627 

WWUS20 KWNS 212138

SEL9

SPC WW 212138

IAZ000-ILZ000-MOZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 369

NWS STORM PREDICTION CENTER NORMAN OK

440 PM CDT MON JUN 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHEASTERN IOWA

       WESTERN AND CENTRAL ILLINOIS

       NORTHEASTERN MISSOURI



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 440 PM UNTIL

1000 PM CDT.



TORNADOES...HAIL TO 2.5 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 70 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 45 MILES WEST NORTHWEST OF

KIRKSVILLE MISSOURI TO 30 MILES SOUTH SOUTHEAST OF MARSEILLES

ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 SEVERE

THUNDERSTORM WATCH NUMBER 366. WATCH NUMBER 366 WILL NOT BE IN

EFFECT AFTER 440 PM CDT. CONTINUE...WW 367...WW 368...



DISCUSSION...STORMS HAVE RECENTLY DEVELOP ALONG OLD OUTFLOW BOUNDARY

LOCATED NEAR THE SERN IA/NERN MO BORDER. STORMS ARE LIKELY TO

INCREASE IN COVERAGE AS UPPER WAVE MOVES EWD THROUGH THE REGION.

DEEP LAYER SHEAR AT 50 KT COMBINED WITH A VERY UNSTABLE AIR MASS IS

FAVORABLE FOR SUPERCELLS. THE MAIN THREAT WILL BE LARGE

HAIL...THOUGH THE

MOIST BOUNDARY LAYER...DEWPOINTS IN THE LOWER/MID 70S AND SHEAR

ALONG THE BOUNDARY ARE ALSO FAVORABLE FOR TORNADOES.



AVIATION...TORNADOES AND 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 25030.





...IMY

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