Illinois, Indiana Flood Watch | Effective 04/17/2026 09:48

* WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...Portions of Illinois, including the following areas, Boone, Central Cook, De Kalb, DuPage, Eastern Will, Ford, Grundy, Iroquois, Kane, Kankakee, Kendall, La Salle, Lake IL, Lee, Livingston, McHenry, Northern Cook, Northern Will, Ogle, Southern Cook, Southern Will and Winnebago and northwest Indiana, including the following areas, Benton, Jasper, Lake IN, Newton and Porter. * WHEN...From 3 PM CDT /4 PM EDT/ this afternoon through late tonight. * IMPACTS...Creeks and streams may rise out of their banks. Ongoing river flooding may worsen. Flooding may occur in poor drainage and urban areas. Roads and streets may be flooded. Area creeks and streams are already elevated, increasing the risk of flooding due to additional rainfall. * ADDITIONAL DETAILS... - Locally heavy showers and thunderstorms with rainfall rates up to 1 to 2 inches per hour may occur across the area later today through the overnight hours. Despite the expected relatively fast storm movement, anomalously high atmospheric moisture content will support high rainfall rates. In many areas, soil moisture remains very high, including areas near the Illinois-Wisconsin border where nearly saturated soils exist due to recent rainfall. While many areas may see lighter accumulations less than 0.5 inches, soils will be sensitive to rainfall. Areas near and downstream of heavy rainfall, particularly urban areas and locations in far northern Illinois, may see flash flooding and river flooding impacts, some locally significant. - http://www.weather.gov/safety/flood