Active Weather Alerts
Flash Flood Warning
Issued: 7:12 AM Sep. 20, 2026 – National Weather Service
The National Weather Service in Chicago has issued a * Flash Flood Warning for... Southern De Kalb County in north central Illinois... Northern La Salle County in north central Illinois... Lee County in north central Illinois... * Until 800 AM CDT. * At 212 AM CDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Up to 3 inches of rain have fallen. The expected rainfall rate is 1.5 to 2.5 inches per hour. Additional rainfall amounts of 1 to 3 inches are possible in the warned area. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar indicated. IMPACT...Rapid-onset flooding of creeks, streams, drainage ditches, streets, underpasses, low-lying areas, and other poor drainage areas. * Some locations that will experience flash flooding include... Sandwich, Mendota, Amboy, Sheridan, Shabbona, Lake Holiday, Hinckley, Somonauk, Earlville, Waterman, Serena, Leland, Paw Paw, Sublette, Woodhaven Lakes, Millington, Lee, Compton, Troy Grove, Nelson, West Brooklyn, Harmon, Triumph, Prairie Center and Lee Center. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Warning means rapid-onset flooding is imminent or may already be occurring. Persons along creeks, drainage ditches, and other waterways should take immediate precautions to protect life and property. Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. && FLASH FLOOD...RADAR INDICATED; EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR
Flood Watch
Issued: 6:33 AM Sep. 20, 2026 – National Weather Service
...FLOOD WATCH NOW IN EFFECT UNTIL 1 PM CDT THIS AFTERNOON... * WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...Portions of Illinois, including the following areas, Boone, Central Cook, De Kalb, DuPage, Eastern Will, Grundy, Kane, Kankakee, Kendall, La Salle, Lake IL, Lee, McHenry, Northern Cook, Northern Will, Ogle, Southern Cook, Southern Will and Winnebago and northwest Indiana, including the following areas, Lake IN and Porter. * WHEN...Until 1 PM CDT this afternoon. * IMPACTS...Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Underpasses may be flooded. Roads and streets may be flooded. Basement flooding may occur. * ADDITIONAL DETAILS... - Periods of showers and thunderstorms are expected through midday. Swaths of torrential rain with 2 inch per hour rainfall rates, or higher are likely to occur within the watch area and may result in areas of flash flooding and cause rapid rises on area rivers, creeks, and streams. - http://www.weather.gov/safety/flood PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flood Watch for flash flooding means rapid-onset flooding is possible, but not yet certain, based upon the latest forecasts. Flash flooding is a dangerous situation. Persons with interests along area rivers, creeks, and other waterways should monitor the latest forecasts and be prepared to take action should flooding develop. &&
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