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645 

WWUS20 KWNS 290456

SEL0

SPC WW 290456

NDZ000-291000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 500

NWS STORM PREDICTION CENTER NORMAN OK

1155 PM CDT WED AUG 28 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  WESTERN AND NORTHERN NORTH DAKOTA



* EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1155

  PM UNTIL 500 AM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 100

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 75 MILES NORTHEAST

OF DICKINSON NORTH DAKOTA TO 10 MILES SOUTH SOUTHWEST OF SIDNEY

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 499...



DISCUSSION...TSTMS ALONG/AHEAD OF ERN MT COLD FRONT HAVE ORGANIZED

INTO A N-S BAND WITH EMBEDDED LEWPS. MOIST...SELY LOW-LVL

WINDS...SURMOUNTED BY 25-30 KT WLY MID-LVL FLOW...MAY CONTINUE TO

SUPPORT FORWARD PROPAGATING LINE SEGMENTS WITH A RISK FOR ISOLD DMGG

WIND AS THE CONVECTIVE BAND CONTINUES E INTO ND. IN ADDITION...SOME

DEGREE OF LARGE-SCALE ASCENT WILL BE PROVIDED BY PROGRESSIVE SK/NRN

MT UPR IMPULSE.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 26030.





...CORFIDI

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