URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 689
NWS Storm Prediction Center Norman OK
135 PM MDT Fri Sep 22 2023
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest South Dakota
* Effective this Friday afternoon and evening from 135 PM until
900 PM MDT.
* Primary threats include…
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
Isolated damaging wind gusts to 70 mph possible
A tornado or two possible
SUMMARY…Isolated severe thunderstorms including some supercells
are expected to develop through mid/late afternoon and spread
east-northeastward across the region through early evening.
The severe thunderstorm watch area is approximately along and 70
statute miles east and west of a line from 35 miles east northeast
of Gillette WY to 55 miles south southeast of Scottsbluff NE. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU9).
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
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