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000 

WWUS20 KWNS 252032

SEL3

SPC WW 252032

IAZ000-260300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 363

NWS STORM PREDICTION CENTER NORMAN OK

330 PM CDT SUN MAY 25 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       A LARGE PART OF IOWA



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 330 PM UNTIL

1000 PM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...

THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE

POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 60 MILES SOUTHWEST OF FORT

DODGE IOWA TO 50 MILES EAST SOUTHEAST OF CEDAR RAPIDS IOWA.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 357...WW 358...WW

359...WW 360...WW 361...



DISCUSSION...VERY TO EXTREMELY UNSTABLE AIR MASS ACROSS MUCH OF IA

AHEAD OF COLD FRONT.  THUNDERSTORMS WILL DEVELOP RAPIDLY AND WITH

STRONG DEEP LAYER SHEAR QUICKLY BECOME SUPERCELLS.  VERY LARGE HAIL

AND TORNADOES ARE LIKELY WITH ANY SUPERCELL. POTENTIAL FOR LONG

LIVED SUPERCELLS WITH STRONG TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 24035.





...HALES

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