

451 

WWUS20 KWNS 051912

SEL0

SPC WW 051912

MTZ000-NEZ000-SDZ000-WYZ000-060300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 490

NWS Storm Prediction Center Norman OK

110 PM MDT Fri Jul 5 2019



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Extreme southeastern Montana

  The western Nebraska Panhandle

  Western South Dakota

  Eastern Wyoming



* Effective this Friday afternoon and evening from 110 PM until

  900 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...Scattered severe thunderstorms are expected to form this

afternoon from southeastern Montana across eastern Wyoming, and then

move east-southeastward into western South Dakota and the western

Nebraska Panhandle through late evening.  Supercells are probable

initially with isolated very large hail possible, while storms may

cluster into this evening with an attendant threat for damaging

winds.  An isolated, brief tornado cannot be ruled out with the

initial discrete supercells.



The severe thunderstorm watch area is approximately along and 65

statute miles east and west of a line from 110 miles north northwest

of Rapid City SD to 30 miles east southeast of Cheyenne WY. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU0).



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 500. Mean storm motion vector

29025.



...Thompson

