Nov 2, 2017
A cold front moved southeastward through south central Illinois and eastern and southern Missouri during the night. Strong thunderstorms located ahead of the front in southern Illinois occurred along a weakening axis of instability. Effective wind shear of around 30 knots, along with marginally steep mid-level lapse rates, was sufficient for nickel-size hail with the stronger updrafts. Locally heavy rain resulted in an isolated flash flooding event.
Source: NOAA National Weather Service Storm Events Database (event 724331). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Franklin County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.