Sep 16, 2025
An omega block pattern set up in mid September and on the 16th Iowa was just west of the ridge axis. This resulted in a hot and humid period and MLCAPE was around 2000-3000 J/kg. The 0-6 km shear was weak under the ridge at under 20 kts. In the deeply unstable environment, pulse thunderstorms were able to develop quickly but the lack of shear prevented better organization and the storms would eventually collapse on themselves. This resulted in widespread scattered thunderstorms across Iowa that
Source: NOAA National Weather Service Storm Events Database (event 1297982). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Webster County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.