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WWUS20 KWNS 050358

SEL8

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IAZ000-ILZ000-MOZ000-050900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 258

NWS STORM PREDICTION CENTER NORMAN OK

1100 PM CDT FRI JUN 4 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME SOUTHEAST IOWA

       EXTREME WEST CENTRAL ILLINOIS

       NORTHERN MISSOURI



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 1100 PM

UNTIL 400 AM CDT.



HAIL TO 2 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 40

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

NORTHWEST OF SAINT JOSEPH MISSOURI TO 60 MILES EAST OF KIRKSVILLE

MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

SEVERE THUNDERSTORM WATCH NUMBER 256. WATCH NUMBER 256 WILL NOT

BE IN EFFECT AFTER 1100 PM CDT.



DISCUSSION...A CLUSTER OF SUPERCELLS PERSISTS ACROSS NW MO...AND

ADDITIONAL CONVECTION HAS BEEN DEVELOPING OVER N CENTRAL MO DURING

THE PAST HOUR.  THE STORMS ARE BEING MAINTAINED BY AN INFLUX OF

MOISTURE/INSTABILITY ON A 30 KT WSWLY SEGMENT OF THE LLJ...AND THE

THREAT FOR LARGE HAIL/DAMAGING WINDS MAY CONTINUE FOR A FEW MORE

HOURS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 28015.





...THOMPSON

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