Illinois Flash Flood Warning | Effective 04/15/2026 21:30

Headline: 
Flash Flood Warning issued April 15 at 11:30PM CDT until April 16 at 2:30AM CDT by NWS Chicago IL
Event: 
Flash Flood Warning
Urgency: 
Immediate
Effective: 
April 15, 2026 - 9:30pm
Expires: 
April 16, 2026 - 12:30am
Description: 
At 1130 PM CDT, Doppler radar rainfall estimates indicated rainfall of 1.30 to 1.85 inches of rain had fallen across northwest Winnebago and far northwest Boone counties since earlier this evening. This rain fell in an area which saw in excess of three inches of rain Tuesday evening. Flash flooding is likely ongoing in some areas. Rainfall has tapered off, though additional showers and isolated thunderstorms remain possible overnight. HAZARD...Flash flooding. SOURCE...Radar. 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... Rockford, Belvidere, Loves Park, Machesney Park, Roscoe, South Beloit, Rockton, Poplar Grove, Rockford Airport, Candlewick Lake, Cherry Valley, Winnebago, Davis Junction, Pecatonica, Lake Summerset, Durand, Capron, Timberlane, New Milford and Garden Prairie. Areas from near Pecatonica to Rockton and South Beloit are in the axis of heaviest rainfall from this evening.
Instruction: 
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.
Area Description: 
Boone, IL; Winnebago, IL
Forcast Office: 
NWS Chicago IL
Sender: 
w-nws.webmaster@noaa.gov