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