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WWUS20 KWNS 011741

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MTZ000-NDZ000-SDZ000-WYZ000-020100-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 143

NWS Storm Prediction Center Norman OK

1145 AM MDT Fri Jun 1 2018



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Eastern Montana

  Southwest North Dakota

  Western South Dakota

  Northeast Wyoming



* Effective this Friday morning and evening from 1145 AM until

  700 PM MDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2.5

    inches in diameter likely

  Scattered damaging wind gusts to 70 mph possible



SUMMARY...Strong to severe thunderstorms ongoing across southeast

Montana and northeast Wyoming at midday will continue to spread

northeastward into a destabilizing air mass across the region. Some

supercells as well as northeastward-racing line segments can be

expected with large hail and damaging winds expected.



The severe thunderstorm watch area is approximately along and 100

statute miles east and west of a line from 30 miles north northwest

of Glendive MT to 65 miles south southeast of Gillette WY. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU3).



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.



&&



AVIATION...A few severe thunderstorms with hail surface and aloft to

2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A

few cumulonimbi with maximum tops to 450. Mean storm motion vector

23035.



...Guyer

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