Flash Flood Warning issued August 12 at 3:53PM CDT until August 12 at 6:30PM CDT by NWS St Louis MO

At 353 PM CDT, Doppler radar indicated thunderstorms were producing
heavy rain in St. Louis City, MO. Between 2 and 3 inches of rain
have fallen. Additional rainfall amounts up to 1 inch are possible
in the warned area. Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

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...
St. Louis, Granite City, Alton, East St. Louis, Edwardsville,
Cahokia, Glen Carbon, Bellefontaine Neighbors, Wood River,
Bethalto, Pontoon Beach, Centreville, Washington Park, Madison,
Riverview, Venice, Spanish Lake, Cahokia Parks Airport, East Alton
and Fairmont City.

This includes the following State Parks...
Scott Joplin Historic Site, Confluence State Park and Horseshoe Lake
State Park.

Numerous instances of flooding due to heavy rain rates and poor
drainage were reported along highways 70, 64, 55, and 44 in downtown
St. Louis City.