NWS Issues Tornado Watch, Flood Alerts for St. Louis Region
A Tornado Watch covering 11 counties across Missouri and Illinois and multiple Flood Watches threatening up to 6 inches of rain are in effect Sunday as severe storms strike the St. Louis region.
ST. LOUIS, MISSOURI — The National Weather Service in St. Louis issued a Tornado Watch and multiple Flood Watches Sunday afternoon for a broad area of Missouri and Illinois, with severe thunderstorms already affecting parts of the region as of midday June 21, 2026.
Tornado Watch in Effect Through Sunday Evening
Tornado Watch 363, issued at 1:35 p.m. CDT, covers 10 Illinois counties and one Missouri county through 9 p.m. CDT Sunday evening, according to the National Weather Service. The sole Missouri county included is Sainte Genevieve, located in southeast Missouri.
In Illinois, the watch spans South Central and Southwest Illinois and covers the following counties: Bond, Clinton, Fayette, Marion, Montgomery, Washington, Madison, Monroe, Randolph, and Saint Clair. The cities of Alton, Belleville, Cahokia, Centralia, Chester, Edwardsville, Litchfield, Salem, Sparta, and Vandalia all fall within the watch area.
Flash Flood Watches Span Wide Area Into Monday Morning
Three separate Flood Watch alerts, all issued at 1:09 p.m. CDT by NWS St. Louis, cover different portions of Missouri and Illinois with varying expiration times. The National Weather Service warns that thunderstorms producing heavy rainfall moving over the same locations could trigger flash flooding, with rainfall totals of 1 to 3 inches expected and locally higher amounts up to 6 inches possible.
The longest-running Flood Watch extends through 7 a.m. CDT Monday and covers Clinton, Marion, Monroe, Randolph, Saint Clair, and Washington counties in Illinois, as well as Crawford, Iron, Jefferson, Madison, Reynolds, Saint Francois, Sainte Genevieve, and Washington counties in Missouri. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone areas, the NWS said.
A second Flood Watch runs through 1 a.m. CDT Monday and covers Bond, Fayette, Greene, Jersey, Macoupin, Madison, and Montgomery counties in Illinois, along with Franklin, Saint Charles, Saint Louis City, and Saint Louis counties in east central Missouri.
A third, shorter-duration Flood Watch expired at 7 p.m. CDT Sunday and included Calhoun County in southwest Illinois and Boone, Callaway, Cole, Gasconade, Lincoln, Moniteau, Montgomery, Osage, and Warren counties in Missouri.
Severe Thunderstorms Already Striking Franklin County Area
Severe thunderstorm activity was already underway in the region Sunday afternoon before the tornado watch was issued. The NWS St. Louis office issued a Severe Thunderstorm Warning at 12:53 p.m. CDT for east central Franklin County in Missouri, valid until 1:30 p.m. CDT. At 12:53 p.m., a severe thunderstorm was located near Parkway, approximately 5 miles east of St. Clair, moving northeast at 25 mph.
The warning cited radar-indicated 60 mph wind gusts capable of causing damage to roofs, siding, and trees. Locations affected included Moselle, Robertsville, Catawissa, Gray Summit, and Pacific, along with Robertsville State Park and Interstate 44 between exits 253 and 257.
A second Severe Thunderstorm Warning was issued at 1:01 p.m. CDT, also through 1:30 p.m. CDT, as the same storm moved northeast and approached Pacific at 40 mph. That warning covered Robertsville, Catawissa, Pacific, and Gray Summit, including Robertsville State Park and Interstate 44 near exit 257, with the same hazard of 60 mph wind gusts.
Residents across the warned counties are advised to monitor official updates from the National Weather Service and seek shelter if conditions deteriorate. Drivers should avoid flooded roadways and low-water crossings throughout the remainder of the day and into Monday morning.
