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747 

WWUS20 KWNS 072310

SEL7

SPC WW 072310

IAZ000-MNZ000-NEZ000-SDZ000-080600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 397

NWS STORM PREDICTION CENTER NORMAN OK

605 PM CDT SUN JUL 7 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHWEST IOWA

  SOUTWEST MINNESOTA

  MUCH OF NORTHERN AND CENTRAL NEBRASKA

  SOUTHERN AND WESTERN SOUTH DAKOTA



* EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 605 PM

  UNTIL 100 AM CDT.



* PRIMARY THREATS INCLUDE...

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

    2.5 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 95

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

NORTHWEST OF CHADRON NEBRASKA TO 60 MILES EAST SOUTHEAST OF SIOUX

FALLS SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 394...WW 395...WW 396...



DISCUSSION...THUNDERSTORMS CONTINUE MOVING SOUTHEASTWARD ACROSS

SOUTHEAST SOUTH DAKOTA INTO AN AXIS OF MODERATE INSTABILITY.

MEANWHILE...STORMS ARE DEVELOPING FARTHER WEST -- ACROSS PARTS OF

NORTHERN NEB...WHILE STILL OTHER/ISOLATED CELLS ARE ONGOING AS FAR

NORTHWEST AS NORTHEAST WYOMING.  AN ANTICIPATED INCREASE IN

CONVECTIVE COVERAGE ACROSS THE WW THIS EVENING WITHIN AN

AMPLY-SHEARED/FAVORABLY UNSTABLE ENVIRONMENT WILL RESULT IN A BROAD

AREA EXPERIENCING POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS

THROUGH THE EVENING HOURS...AS STORMS MOVE SOUTHEASTWARD WITH TIME

ACROSS THE WW AREA.



AVIATION...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 500. MEAN STORM

MOTION VECTOR 29035.





...GOSS

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