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436 

WWUS20 KWNS 252225

SEL5

SPC WW 252225

IAZ000-MNZ000-NEZ000-SDZ000-260600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 445

NWS STORM PREDICTION CENTER NORMAN OK

520 PM CDT THU JUL 25 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN AND WESTERN IOWA

  FAR SOUTHWEST MINNESOTA

  SOUTH CENTRAL THROUGH NORTHEAST AND EAST CENTRAL NEBRASKA

  FAR SOUTHEAST SOUTH DAKOTA



* EFFECTIVE THIS THURSDAY AFTERNOON AND FRIDAY MORNING FROM 520

  PM UNTIL 100 AM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHEAST

OF STORM LAKE IOWA TO 70 MILES SOUTHWEST OF BROKEN BOW NEBRASKA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 443...WW 444...



DISCUSSION...TSTMS EXPECTED TO INCREASE IN COVERAGE/STRENGTH ALONG

PRE-COLD FRONTAL TROUGH/WIND SHIFT ARCING FROM S CNTRL NEB NE AND

ENE ACROSS PARTS OF ERN NEB INTO NW IA/SRN MN....WHERE ASCENT WILL

INCREASE DOWNSTREAM FROM AMPLIFYING NRN STREAM SHORTWAVE IMPULSE.

THE STORMS WILL BE SOMEWHAT REMOVED FROM THE STRONGEST LARGE SCALE

FORCING FOR ASCENT. BUT COMBINATION OF FAIRLY RICH LOW-LVL MOISTURE

WITH SUFFICIENT DEEP SHEAR FOR A FEW SUSTAINED STORMS/SUPERCELLS

SUGGESTS A RISK FOR SVR HAIL...LOCALLY DMGG WIND...AND PERHAPS A

TORNADO THROUGH MID TO LATE EVE.



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 29020.





...CORFIDI

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