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WWUS20 KWNS 312205

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URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 238

NWS Storm Prediction Center Norman OK

405 PM MDT Sun May 31 2020



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Parts of east central and southeast Montana

  Southwest North Dakota

  West central and northwest South Dakota

  Northeast Wyoming



* Effective this Sunday afternoon and evening from 405 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



SUMMARY...Scattered thunderstorm development is underway along and

east of a surface trough, and the storms will encounter somewhat

richer moisture to the east and should intensify some this evening.

The storm environment is supportive of a mix of organized clusters

and supercells, with the attendant threat for large hail and

damaging winds.



The severe thunderstorm watch area is approximately along and 60

statute miles east and west of a line from 15 miles east northeast

of Glendive MT to 15 miles southwest of Rapid City SD. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU8).



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

few cumulonimbi with maximum tops to 500. Mean storm motion vector

27025.



...Thompson

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