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214 

WWUS20 KWNS 272339

SEL5

SPC WW 272339

SDZ000-280400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 355

NWS Storm Prediction Center Norman OK

640 PM CDT Mon Aug 27 2018



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  South central South Dakota



* Effective this Monday evening from 640 PM until 1100 PM CDT.



* Primary threats include...

  Scattered large hail likely with isolated very large hail events

    to 2 inches in diameter possible

  Isolated damaging wind gusts to 70 mph possible



SUMMARY...A small cluster of severe storms will likely persist while

moving east-southeastward along a frontal zone the next few hours,

in an environment that will remain supportive of supercells.  Large

hail will be the main threat, before the storms weaken by 10-11pm

CDT.



The severe thunderstorm watch area is approximately along and 45

statute miles north and south of a line from 55 miles southwest of

Pierre SD to 5 miles northeast of Mitchell SD. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU5).



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 353...WW 354...



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

28035.



...Thompson

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