A severe thunderstorm watch is in effect until 9 p.m. Wednesday, with the possibility of hail.
The National Weather Service issued a severe thunderstorm watch for 20 counties in Missouri, including St. Louis County and St. Louis, and 16 counties in south central Illinois.
The storms could include very large hail, damaging wind gusts and a few tornadoes, the National Weather Service said.
The counties in Missouri under the watch include: St. Louis County, city of St. Louis, Jefferson, St. Charles, Warren, Lincoln, Franklin, Boone, Montgomery, Monroe, Knox, Shelby, Callaway, Audrain, Marion, Gasconade, Osage and Ralls.
In Illinois, the severe thunderstorm watch includes Monroe, Madison, Bond, St. Clair, Clinton, Montgomery, Fayette, Greene, Macoupin, Jersey, Washington, Marion, Brown, Calhoun, Adams and Pike.
