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878 

WWUS20 KWNS 171929

SEL6

SPC WW 171929

COZ000-IDZ000-UTZ000-WYZ000-180300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 526

NWS STORM PREDICTION CENTER NORMAN OK

130 PM MDT TUE SEP 17 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHWEST COLORADO

  EASTERN IDAHO

  NORTHERN UTAH

  WESTERN AND CENTRAL WYOMING



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 130 PM UNTIL

  900 PM MDT.



* 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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 105

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES WEST

NORTHWEST OF CODY WYOMING TO 25 MILES WEST SOUTHWEST OF VERNAL

UTAH.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



&&



DISCUSSION...THUNDERSTORMS ARE DEVELOPING OVER MUCH OF THE WATCH

AREA THIS AFTERNOON..IN A SUFFICIENTLY MOIST AND UNSTABLE

ENVIRONMENT.  AN APPROACHING UPPER TROUGH WILL STRENGTHEN THE WINDS

ALOFT...PROMOTING THE RISK OF GUSTY/DAMAGING WINDS AND HAIL IN THE

STRONGEST CELLS.



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 450. MEAN STORM

MOTION VECTOR 25035.





...HART

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