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000 

WWUS20 KWNS 212054

SEL0

SPC WW 212054

IAZ000-MNZ000-WIZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 680

NWS STORM PREDICTION CENTER NORMAN OK

355 PM CDT FRI SEP 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF CENTRAL AND NORTHEAST IOWA

       SMALL PART OF SOUTHEAST MINNESOTA

       PARTS OF SOUTHWEST WISCONSIN



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 355 PM UNTIL

1100 PM 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH OF

LONEROCK WISCONSIN TO 15 MILES WEST SOUTHWEST OF KNOXVILLE IOWA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 679...



DISCUSSION...CAP HAS WEAKENED ALLOWING STORMS TO DEVELOP ALONG/AHEAD

OF COLD FRONT. WITH THE STRONG WIND PROFILES ASSOCIATED WITH

APPROACHING VIGOROUS S/WV TROUGH...CONDITIONS ARE FAVORABLE FOR

DAMAGING WINDS AND LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 24035.





...HALES

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