WWUS20 KWNS 011741
SEL3
SPC WW 011741
MTZ000-NDZ000-SDZ000-WYZ000-020100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 143
NWS Storm Prediction Center Norman OK
1145 AM MDT Fri Jun 1 2018

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Eastern Montana
  Southwest North Dakota
  Western South Dakota
  Northeast Wyoming

* Effective this Friday morning and evening from 1145 AM until
  700 PM MDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter likely
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Strong to severe thunderstorms ongoing across southeast
Montana and northeast Wyoming at midday will continue to spread
northeastward into a destabilizing air mass across the region. Some
supercells as well as northeastward-racing line segments can be
expected with large hail and damaging winds expected.

The severe thunderstorm watch area is approximately along and 100
statute miles east and west of a line from 30 miles north northwest
of Glendive MT to 65 miles south southeast of Gillette WY. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU3).

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
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
23035.

...Guyer