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233 

WWUS20 KWNS 230349

SEL9

SPC WW 230349

IAZ000-231100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 389

NWS STORM PREDICTION CENTER NORMAN OK

1050 PM CDT TUE JUN 22 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHERN IOWA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 1050 PM

UNTIL 600 AM 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 35 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 50 MILES WEST NORTHWEST OF

FORT DODGE IOWA TO 10 MILES NORTH OF WATERLOO IOWA.  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...CONTINUE...WW 385...WW 386...WW

387...WW 388...



DISCUSSION...A SMALL GROUP OF SUPERCELLS WERE LOCATED IN NRN IOWA

AND THOUGH LARGE HAIL AND WIND DAMAGE WILL BE THE MAIN THREAT...

TORNADOES ARE ALSO POSSIBLE GIVEN THAT THE STORMS ARE LOCATED NEAR A

BOUNDARY IN A VERY MOIST BOUNDARY LAYER.



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 27020.





...IMY

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