

401 

WWUS20 KWNS 302101

SEL7

SPC WW 302101

SDZ000-310300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 477

NWS Storm Prediction Center Norman OK

305 PM MDT Mon Aug 30 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Westner to central South Dakota



* Effective this Monday afternoon and evening from 305 PM until

  900 PM MDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2.5

    inches in diameter possible

  Isolated significant damaging wind gusts to 75 mph possible

  A tornado or two possible



SUMMARY...A couple supercells may develop from the Black Hills to

the South Dakota-North Dakota border area this evening.



The severe thunderstorm watch area is approximately along and 60

statute miles east and west of a line from 40 miles northwest of

Mobridge SD to 55 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 475...WW 476...



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

2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A

few cumulonimbi with maximum tops to 550. Mean storm motion vector

32025.



...Grams

