⚠️ Severe Thunderstorm Warning – Clay, SD; Union, SD; Yankton, SD – Tuesday, September 1, 2026

Severe Thunderstorm Warning issued September 1 at 8:41PM CDT until September 1 at 9:30PM CDT by NWS Sioux Falls SD

Details

SVRFSD

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for…
Clay County in southeastern South Dakota…
Southeastern Yankton County in southeastern South Dakota…
Northwestern Union County in southeastern South Dakota…

* Until 930 PM CDT.

* At 840 PM CDT, a severe thunderstorm was located near St. Helena,
or 12 miles southeast of Yankton, moving east at 40 mph.

THIS IS A DESTRUCTIVE STORM FOR GAYVILLE, VERMILLION, AND UNION
GROVE STATE PARK

HAZARD…80 mph wind gusts and half dollar size hail.

SOURCE…Public.

IMPACT…Flying debris will be dangerous to those caught without
shelter. Mobile homes will be heavily damaged. Expect
considerable damage to roofs, windows, and vehicles.
Extensive tree damage and power outages are likely.

* This severe thunderstorm will be near…
Vermillion and Meckling around 850 PM CDT.
Union Grove State Park around 905 PM CDT.

Instructions

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Sioux Falls.

This alert was automatically posted by SkyGuard, MWSC’s severe weather alerting system. Source: National Weather Service.