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WWUS20 KWNS 101147

SEL1

SPC WW 101147

IAZ000-NEZ000-SDZ000-101900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 291

NWS STORM PREDICTION CENTER NORMAN OK

645 AM CDT THU JUN 10 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND CENTRAL IOWA

       EASTERN NEBRASKA

       EXTREME SOUTHEASTERN SOUTH DAKOTA



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 645 AM UNTIL

200 PM CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

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 40 MILES WEST OF

TEKAMAH NEBRASKA TO 40 MILES NORTH NORTHEAST OF KNOXVILLE IOWA.

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 290...



DISCUSSION...BAND OF TSTMS...IN ELEVATED WAA ZONE PRECEDING PRIMARY

MCS...WILL MOVE INTO WW AREA SHORTLY...POSING THREAT FOR LARGE HAIL.

 THEREAFTER...BOWING MCS IS FCST TO MOVE EWD TO ESEWD ACROSS ERN NEB

AND MO RIVER VALLEY.  ALTHOUGH ENTERING GRADUALLY MORE STABLE

ENVIRONMENT WITH TIME...MOIST/WARM ADVECTION WITH FOREGOING/VEERING

LLJ WILL YIELD AT LEAST MARGINALLY FAVORABLE BUOYANCY TO EXTEND

THREAT FOR DAMAGING WIND E OF WW 269 AND ACROSS PORTIONS IA.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 27035.





...EDWARDS/CORFIDI

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