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WWUS20 KWNS 311947

SEL0

SPC WW 311947

MTZ000-010400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 140

NWS Storm Prediction Center Norman OK

150 PM MDT Thu May 31 2018



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Montana



* Effective this Thursday afternoon and evening from 150 PM until

  1000 PM MDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible

  Scattered damaging wind gusts to 70 mph possible

  A tornado or two possible



SUMMARY...Strong to severe thunderstorms will continue to develop

this afternoon, initially across western and southern Montana, and

spread east-northeastward through late afternoon and evening. Strong

shear and a very moist environment will support the potential for

large hail and damaging winds.



The severe thunderstorm watch area is approximately along and 80

statute miles north and south of a line from 35 miles northwest of

Butte MT to 25 miles southeast of Miles City MT. 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 136...WW 137...WW

138...WW 139...



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 500. Mean storm motion vector

24030.



...Guyer

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