Flash Flood — Union, South Dakota

2025-07-24 · near Beresford, Union, South Dakota

Event narrative

Multiple roadways and intersections were inundated by water deep enough to impede travel.

Wider weather episode

A cluster of thunderstorms erupted within a very moist and unstable airmass ahead of a slow moving frontal boundary during the evening of July 23. These thunderstorms bisected the city of Sioux Falls from southwest to northeast with neighborhoods southeast of I-229 reporting 2 to 5 inches of rain in a matter of 1-2 hours. This resulted in significant flash flooding across impacted portions of the city. Later in the evening, a large mesoscale convective system across Nebraska moved north and east, bringing heavy rain to portions of southeast South Dakota. Additional localized flash flooding was observed after midnight in Beresford, South Dakota.

View location on OpenStreetMap → (43.0834, -96.7652)

Source: NOAA Storm Events Database, event_id 1287280. Narrative written by the NWS forecast office that issued the report.