Jul 19, 2025
As high pressure slowly crept northward towards the Quad State region, ridging remained over the middle Mississippi River Valley. A slow-moving MCS moved through the northeastern half of the Quad State midday to near sunset. CAPE rose to 1000-2000J/kg in northern portions of Southern Illinois with effective bulk shear around 30kts. Extremely high moisture content with precipitable water values of 2.25in resulted in torrential rainfall rates along and near the I-64 corridor. Several areas reporte
Source: NOAA National Weather Service Storm Events Database (event 1305164). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Williamson County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.