Illinois - United States   2026-09-20   Sunday   41.78N, -89.69W

Rock Falls

Illinois - United States
2026-09-20

Flash Flood Warning issued September 20 at 5:00AM CDT until September 20 at 7:30AM CDT by NWS Quad Cities IA IL

Issue date: 2026-09-20T10:00+00:00

At 500 AM CDT, Doppler radar indicated a large area of light to moderate rain was occurring across the warned area. Heavy rain producing storms earlier brought rainfall of 1 to 3.5 inches across the warned area. Flash flooding is either ongoing or expected to begin shortly due to runoff from the earlier heavy rain combined with the steady rain falling. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar indicated. IMPACT...Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas. Some locations that will experience flash flooding include... Davenport, Moline, Rock Island, Bettendorf, Muscatine, East Moline, Kewanee, Aledo, Cambridge, Silvis, Geneseo, Eldridge, Colona, Milan, Le Claire, Coal Valley and Galva. This includes the following State Parks... Big Bend Fish and Wildlife Area, Johnson-Sauk Trail State Recreation Area and Prophetstown State Park. This includes the following highways... Interstate 74 in Iowa between mile markers 1 and 5. Interstate 280 between mile markers 1 and 18. Interstate 80 in Iowa between mile markers 279 and 306. Interstate 80 in Illinois between mile markers 1 and 43. Interstate 74 in Illinois between mile markers 1 and 33. Interstate 88 between mile markers 1 and 32...and between mile markers 36 and 43.

Flood Watch issued September 19 at 9:12PM CDT until September 25 at 9:00AM CDT by NWS Quad Cities IA IL

Issue date: 2026-09-20T02:12+00:00

...Forecast flooding changed from Minor to Moderate severity and increased in duration for the following rivers in Illinois... Rock River near Joslin affecting Rock Island, Whiteside and Henry IL zones. Rock River at Moline affecting Rock Island and Henry IL zones. * WHAT...Flooding is possible. * WHERE...Rock River near Joslin. * WHEN...From late Sunday night to Friday morning. * ADDITIONAL DETAILS... - At 7:45 PM CDT Saturday the stage was 5.9 feet. - Forecast...Flood stage may be reached early Monday morning. - Flood stage is 12.0 feet.

Flood Watch issued September 19 at 8:00PM CDT until September 20 at 7:00AM CDT by NWS Quad Cities IA IL

Issue date: 2026-09-20T01:00+00:00

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...Portions of northwest Illinois, including the following counties, Carroll, Jo Daviess, Mercer, Rock Island, Stephenson and Whiteside and Iowa, including the following counties, Benton, Buchanan, Cedar, Clinton, Delaware, Dubuque, Iowa, Jackson, Johnson, Jones, Linn, Louisa, Muscatine, Scott and Washington. * WHEN...Until 7 AM CDT Sunday. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - Widespread showers and storms are expected to develop again this evening and last into Sunday. These storms will be capable of rainfall rates between 1 to 2 inches per hour. Rainfall totals of 1 to 3 inches are likely in the hardest hit areas tonight, with the potential for localized areas of 3+ inches.