Illinois, Missouri Flood Warning | Effective 05/01/2026 19:40

Headline: 
Flood Warning issued May 1 at 9:40PM CDT until May 5 at 11:30PM CDT by NWS St Louis MO
Event: 
Flood Warning
Urgency: 
Immediate
Effective: 
May 1, 2026 - 7:40pm
Expires: 
May 3, 2026 - 7:45am
Description: 
...The Flood Warning continues for the following rivers in Missouri...Illinois... Mississippi River at Alton. Mississippi River near Herculaneum. Mississippi River at Chester. ...The Flood Warning is extended for the following rivers in Missouri...Illinois... Mississippi River at Mel Price LD. Mississippi River at Grafton. River forecasts are based on observed precipitation and forecast precipitation for the next 24 hours. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Mississippi River at Grafton. * WHEN...Until Tuesday evening. * IMPACTS...At 22.5 feet, East end of Main Street in Portage des Sioux begins flooding near this height. * ADDITIONAL DETAILS... - At 9:00 PM CDT Friday the stage was 22.6 feet and falling. - Recent Activity...The river rose above flood stage on April 19. It crested near 22.9 feet on May 1. - Forecast...The river is expected to fall below flood stage Monday afternoon and continue falling over the following days. - Flood stage is 20.0 feet.
Instruction: 
Motorists should not attempt to drive around barricades or drive cars through flooded areas. This product, along with additional weather and stream information, is available at https://water.noaa.gov/wfo/lsx
Area Description: 
Jersey, IL; St. Charles, MO
Forcast Office: 
NWS St Louis MO
Sender: 
w-nws.webmaster@noaa.gov