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Flash Flood — Sioux, IA

Jun 9, 2020

Additional severe thunderstorms developed near a slowly advancing cold front during the late afternoon and evening hours across southeast South Dakota and northwest Iowa. MLCAPE reached a bit over 1000 J/kg with marginal deep-layer shear at around 30 knots. A strong wake low developed within the stratiform region behind the main line of convection, and produced high winds and some damage in parts of northwest Iowa later in the evening.

Source: NOAA National Weather Service Storm Events Database (event 905600). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Sioux, IA

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.

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