Flash Flood — Lyman, South Dakota

2011-06-20 to 2011-06-21 · near Lower Brule, Lyman, South Dakota

Event narrative

Very heavy rainfall of 5 to 7 inches brought flash flooding to mainly eastern Lyman county. Many roads were flooded with some washed out. Two women died in two separate vehicles after driving into a washed out portion of a road. One woman was found 100 yards downstream while the other woman was found 4 miles downstream. The accidents were believed to happen between 930 and 10 am. The location was 9 miles north of Reliance on BIA 10 just north of the intersection with Highway 47.

Wider weather episode

A large upper level low pressure area along with deep moisture brought very heavy rains to central South Dakota. Rainfall amounts of 3 to 7 inches occurred across parts of the area resulting in flash flooding.

View location on OpenStreetMap → (44.0437, -99.4970)

Source: NOAA Storm Events Database, event_id 326376. Narrative written by the NWS forecast office that issued the report.