

252 

WWUS20 KWNS 032238

SEL9

SPC WW 032238

MTZ000-NEZ000-SDZ000-WYZ000-040600-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 259

NWS Storm Prediction Center Norman OK

440 PM MDT Tue Jul 3 2018



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Extreme southeastern Montana

  Extreme northwestern Nebraska

  Western South Dakota

  Northeastern Wyoming



* Effective this Tuesday afternoon from 440 PM until Midnight

  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...Isolated storms are developing across northeastern Wyoming

and northwestern Nebraska this afternoon, and the storms should

gradually increase in coverage and grow upscale into a cluster or

two by this evening across western South Dakota.  Supercells will be

possible initially with large hail, while the damaging wind threat

will increase by this evening as upscale growth occurs.



The severe thunderstorm watch area is approximately along and 80

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

of Buffalo SD to 70 miles south of Rapid City SD. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU9).



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 550. Mean storm motion vector

24030.



...Thompson

