

000 

WWUS20 KWNS 210200

SEL2

SPC WW 210200

IAZ000-NEZ000-SDZ000-210900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 712

NWS STORM PREDICTION CENTER NORMAN OK

900 PM CDT SUN JUL 20 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       CENTRAL AND EASTERN NEBRASKA

       FAR SOUTHERN SOUTH DAKOTA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 900 PM UNTIL

400 AM CDT.



HAIL TO 3 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 NORTH AND SOUTH OF A LINE FROM 35 MILES NORTH

NORTHWEST OF BURWELL NEBRASKA TO 20 MILES EAST SOUTHEAST OF

DENISON IOWA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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 711...



DISCUSSION...SEVERE THUNDERSTORMS WILL BECOME INCREASINGLY

WIDESPREAD ACROSS WW THIS EVENING...WITH PRIMARY THREAT FROM

POSSIBLE DERECHO MCS EVOLVING AND TRACKING ESEWD ALONG SURFACE FRONT

INTO ERN NEB/WRN IA BY 06-09Z.  OTHER ISOLATED SEVERE STORMS CAN BE

EXPECTED AHEAD OF THIS MCS NEAR AND NORTH OF THE FRONT.  WIND DAMAGE

MAY BECOME WIDESPREAD/SIGNIFICANT WITH MAIN MCS.  LARGE HAIL /SOME

OF WHICH COULD BECOME QUITE LARGE/DAMAGING/ IS ALSO

POSSIBLE...ESPECIALLY WITH STORMS AHEAD OF MAIN LINE.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27035.





...EVANS

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