

673 

WWUS20 KWNS 142003

SEL1

SPC WW 142003

IDZ000-MTZ000-WYZ000-150300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 421

NWS STORM PREDICTION CENTER NORMAN OK

205 PM MDT MON JUL 14 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHEAST IDAHO

  WESTERN MONTANA

  NORTHWEST WYOMING



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 205 PM UNTIL

  900 PM MDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 115

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTHWEST

OF SALMON IDAHO TO 45 MILES EAST SOUTHEAST OF WEST YELLOWSTONE

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 417...WW 418...WW

419...WW 420...



DISCUSSION...SCATTERED THUNDERSTORMS ARE FORMING OVER NORTHEAST ID

AHEAD OF A STRONG UPPER TROUGH.  OTHER STORMS WILL FORM ACROSS THE

WATCH AREA THROUGH THE AFTERNOON AND EARLY EVENING HOURS.  STRONG

VERTICAL SHEAR AND STEEP LAPSE RATES WILL POSE A RISK OF ORGANIZED

STORMS CAPABLE OF HAIL AND DAMAGING WINDS.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27030.





...HART

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