

891 

WWUS20 KWNS 202048

SEL5

SPC WW 202048

MTZ000-NDZ000-SDZ000-210400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 425

NWS Storm Prediction Center Norman OK

250 PM MDT Thu Jul 20 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Eastern Montana

  Western North Dakota

  Northwest South Dakota



* Effective this Thursday afternoon and evening from 250 PM until

  1000 PM MDT.



* Primary threats include...

  Scattered large hail likely with isolated very large hail events

    to 2.5 inches in diameter possible

  Scattered damaging wind gusts to 70 mph possible

  A tornado or two possible



SUMMARY...Thunderstorms will continue to intensify over the watch

area this afternoon and early evening, posing a threat of very large

hail and damaging wind gusts.



The severe thunderstorm watch area is approximately along and 80

statute miles east and west of a line from 60 miles north northeast

of Williston ND to 40 miles south southwest of Buffalo 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 424...



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

27030.



...Hart

