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WWUS20 KWNS 092331

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URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 357

NWS Storm Prediction Center Norman OK

535 PM MDT Fri Jul 9 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Southwest South Dakota

  Northeast Wyoming



* Effective this Friday afternoon and evening from 535 PM until

  1100 PM MDT.



* Primary threats include...

  Scattered damaging wind gusts to 70 mph possible

  Scattered large hail events to 1.5 inches in diameter possible



SUMMARY...A small cluster with embedded supercells is expected to

move east-southeastward across northeast Wyoming and southwest South

Dakota this evening through early tonight.  The strongest storms

will be capable of producing occasional large hail and damaging

outflow gusts.



The severe thunderstorm watch area is approximately along and 40

statute miles north and south of a line from 25 miles west northwest

of Gillette WY to 40 miles south southeast of Rapid City SD. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU7).



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 356...



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 450. Mean storm motion vector

30035.



...Thompson

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