Flash Flood Warnings Hit St. Louis Metro Area as Storms Dump Heavy Rain
Thunderstorms dumped up to 2 inches of rain across the St. Louis metro area Sunday, triggering multiple flash flood warnings as officials warned of dangerous conditions on roadways and in low-lying areas.
ST. LOUIS, MISSOURI — Flash flood warnings covered the St. Louis metropolitan area Sunday evening as thunderstorms brought heavy rainfall to east central Missouri and southwestern Illinois, raising concerns about flooding.
The National Weather Service in St. Louis issued a flash flood warning at 8:09 PM CDT for areas including Belleville, Granite City, O’Fallon, East St. Louis, Collinsville, Edwardsville, Fairview Heights, Cahokia, Swansea, Glen Carbon, Shiloh, Highland, Troy, Waterloo, Columbia, Maryville, Mascoutah, Pontoon Beach, and Centreville. The warning was in effect until 9:00 PM CDT.
Doppler radar data indicated that between 1 and 2 inches of rain had already fallen across the warned areas by Sunday evening. Additional rainfall amounts of 1 to 2 inches were possible, creating conditions for ongoing or imminent flash flooding.
Multiple Counties Under Warning
Earlier Sunday, the weather service issued a separate flash flood warning at 5:12 PM CDT for Saint Charles County, Saint Louis County, and Saint Louis City, which remained in effect until 8:15 PM CDT. Communities expected to experience flash flooding included St. Louis, O’Fallon, St. Charles, St. Peters, Florissant, Chesterfield, Wildwood, University City, Ballwin, Wentzville, Kirkwood, Maryland Heights, and Hazelwood.
The warnings affected major transportation corridors, including Interstate 64 in Illinois between exits 9 and 27, and Interstate 70. State recreational areas Frank Holten State Park and Horseshoe Lake State Park were also within the flash flood warning zones.
Urban Areas Face Particular Risk
Weather officials warned that flash flooding would primarily impact small creeks and streams, urban areas, highways, streets, and underpasses, as well as other poor drainage and low-lying areas. The combination of heavy rainfall and urban development increased risks for rapidly rising water levels.
Flood advisories were also issued earlier in the day, beginning at 1:22 PM CDT for Saint Louis County and Saint Louis City, warning of urban area and small stream flooding caused by excessive rainfall. These advisories extended until 7:15 PM CDT and covered additional communities including Webster Groves, Manchester, Creve Coeur, Clayton, Jennings, Crestwood, Town and Country, and Eureka.
The thunderstorms marked a significant weather event for the region, with radar-indicated rainfall totals consistently showing 1 to 2 inches across affected areas. Weather service officials noted that the flooding was caused by thunderstorms producing heavy rain, with additional rainfall expected to worsen conditions in low-lying and poorly drained areas throughout the evening hours.
