Today, St. Louis weather takes a turbulent turn with the National Weather Service issuing a flash flood warning for parts of Illinois and Missouri as persistent rains batter the region. The cities impacted include southern Madison, northwestern Monroe, and Saint Clair counties in Illinois, as well as Saint Louis County and the city of Saint Louis in Missouri, with local law enforcement reporting heavy rainfall causing concerns of flash flooding continuing until 7:15 AM CST, NWS reports.