

805 

WWUS20 KWNS 222030

SEL6

SPC WW 222030

IDZ000-MTZ000-WYZ000-230400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 86

NWS STORM PREDICTION CENTER NORMAN OK

230 PM MDT TUE APR 22 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EASTERN IDAHO

  SOUTHWEST MONTANA

  WESTERN WYOMING



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 230 PM UNTIL

  1000 PM MDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES SOUTHEAST OF

MALAD CITY IDAHO TO 40 MILES WEST NORTHWEST OF HARLOWTON MONTANA.

 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...TSTMS EXPECTED TO INCREASE IN COVERAGE/STRENGTH THROUGH

EARLY TNGT ALONG AND AHEAD OF INTENSIFYING COLD FRONT CROSSING THE

NRN GRT BASIN/NRN RCKYS...WITH DEVELOPMENT AIDED BY UPR IMPULSE

APPROACHING FROM NV. STRENGTH OF LARGELY UNIDIRECTIONAL SSWLY WIND

FIELD AND RELATIVELY STEEP LOW TO MID-LVL LAPSE RATES SUGGEST

POTENTIAL FOR DOWNWARD MOMENTUM TRANSFER AND POSSIBLY DMGG SFC WIND

GUSTS DESPITE SPARSE MOISTURE.



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 400. MEAN STORM MOTION

VECTOR 21040.





...CORFIDI

