May 24, 2010
A strong upper level wave combined with abundant moisture to produce strong thunderstorms over western South Dakota. Torrential rain of two to four inches fell across the eastern and southern slopes of the Black Hills in a brief period, causing flooding from Piedmont southward to the Nebraska border. Flood waters continued downstream on the Cheyenne River to the Missouri River.
Source: NOAA National Weather Service Storm Events Database (event 230453). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Pennington County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.