Jul 1, 2019
Thunderstorms developed during the evening along an outflow-reinforced frontal zone as a zonal pattern aloft sent a minor wave rippling from central South Dakota into southern Minnesota during the evening. A low-level jet of 30 knots interacted with the boundary to create a favorable environment for redeveloping and training storms over a several hour period, which progressed very slowly southward through portions of northwest Iowa.
Source: NOAA National Weather Service Storm Events Database (event 842487). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Sioux County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.