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027 

WWUS20 KWNS 052158

SEL2

SPC WW 052158

IDZ000-MTZ000-060500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 512

NWS STORM PREDICTION CENTER NORMAN OK

355 PM MDT THU SEP 5 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EASTERN IDAHO

  SOUTHWESTERN MONTANA



* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 355 PM UNTIL

  1100 PM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 75

    MPH POSSIBLE

  A FEW VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70

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

CITY IDAHO TO 45 MILES NORTHWEST OF DILLON MONTANA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU2).



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 511...



DISCUSSION...SVR POTENTIAL CHARACTERISTIC TO ERN PORTIONS WW 511 IS

EXPECTED TO SPREAD EWD ACROSS WW 512 AREA THROUGH REMAINDER AFTN AND

INTO EVENING...INTO AIR MASS WITH 40-50 KT EFFECTIVE SHEAR MAGNITUDE

AND AT LEAST MRGLLY FAVORABLE BUOYANCY.  DAMAGING WIND AND SPORADIC

LARGE HAIL ARE EXPECTED.  REF SPC MESOSCALE DISCUSSION 1839 FOR

ADDITIONAL/INITIAL METEOROLOGICAL DETAILS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

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

MOTION VECTOR 21035.





...EDWARDS

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