Weather Alerts For Caseyville, IL

# SUMMARY -------------------- TORNADO WATCH 363 REMAINS VALID UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING AREAS IN ILLINOIS THIS WATCH INCLUDES 10 COUNTIES IN SOUTH CENTRAL ILLINOIS BOND CLINTON FAYETTE MARION MONTGOMERY WASHINGTON IN SOUTHWEST ILLINOIS MADISON MONROE RANDOLPH SAINT CLAIR IN MISSOURI THIS WATCH INCLUDES 1 COUNTY IN SOUTHEAST MISSOURI SAINTE GENEVIEVE THIS INCLUDES THE CITIES OF ALTON, BELLEVILLE, CAHOKIA, CENTRALIA, CHESTER, EDWARDSVILLE, LITCHFIELD, SALEM, SPARTA, AND VANDALIA. # DETAILS -------------------- ISSUED AT Sunday, June 21, 2026 at 8:21 PM CDT ISSUED BY NATIONAL WEATHER SERVICE ST LOUIS MO HEADER WATCH COUNTY NOTIFICATION FOR WATCHES 363/366

# HEADLINE -------------------- FLOOD WATCH REMAINS IN EFFECT UNTIL 7 AM CDT MONDAY # DETAILS -------------------- WHAT Flash flooding caused by excessive rainfall continues to be possible. WHERE Portions of Illinois, including the following areas, Clinton IL, Marion IL, Monroe IL, Randolph IL, Saint Clair IL and Washington IL and Missouri, including the following areas, Crawford MO, Iron MO, Jefferson MO, Madison MO, Reynolds MO, Saint Francois MO, Sainte Genevieve MO and Washington MO. WHEN Until 7 AM CDT Monday. IMPACTS Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. ADDITIONAL DETAILS - Thunderstorms producing heavy rainfall moving over the same locations could produce flash flooding. Rainfall amounts of 1-3 inches are expected with locally higher amounts up to 6 inches possible. ISSUED AT Sunday, June 21, 2026 at 7:14 PM CDT ISSUED BY National Weather Service St Louis MO HEADER Flood Watch # PRECAUTIONARY/PREPAREDNESS ACTIONS -------------------- You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. # AREAS AFFECTED -------------------- Monroe IL, Clinton IL, Crawford MO, Iron MO, Jefferson MO, Madison MO, Marion IL, Randolph IL, Reynolds MO, Saint Clair IL, Saint Francois MO, Sainte Genevieve MO, Washington IL, Washington MO Including the cities of Farmington, Chester, Salem, Cahokia, Belleville, Centralia, and Sparta

There is a Slight Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST KS INTO NORTH-CENTRAL OK SUMMARY Tornadoes (possibly strong) and damaging winds remain possible this evening into parts of the Mississippi and Ohio Valleys. A swath of severe gusts (possibly greater than 75 mph) appears possible later tonight from southwest Kansas into central Oklahoma. Mid MS Valley into the Ohio Valley An MCV moving across IN will eventually encounter weaker low-level moisture and instability with eastward extent. However, a long-lived storm cluster may continue eastward toward parts of southwest OH and eastern KY, before a definitive weakening trend occurs. Damaging wind and embedded tornadoes will remain possible with the primary storm cluster until weakening occurs. Semi-discrete cells and small clusters trailing the MCV will also continue to pose a threat of tornadoes (possibly strong) and damaging winds through the evening, within a moist and favorably sheared environment. See MCD 1237 for more information. Central High Plains into OK and southern MO Widely scattered storm development is underway near a surface boundary draped from northwest OK into southeast KS/southwest MO. While large-scale forcing is generally modest at best, MLCAPE of 2500-4000 J/kg and effective shear of 40+ kt are conditionally quite favorable for organized storms. A few supercells may persist along the front through the evening, with a threat of large to very large hail and localized severe gusts. Also, while low-level flow is weak, vorticity and backed surface winds near the boundary could support some tornado potential, if a robust supercell can become established. Farther northwest, a supercell cluster is ongoing across western KS this evening. This cluster will continue to pose a threat of large to very large hail, severe gusts, and possibly a tornado through the evening. See MCD 1239 for more information regarding the short-term threat. Short-term guidance (notably the HRRR and RRFS) suggests that this cluster will continue to grow upscale, and potentially evolve into an MCS that will move southeastward across southwest KS into northwest and central OK, with threat of severe gusts (potentially above 75 mph) through the overnight hours. This evolution appears plausible, if evening convection across northwest OK is not too disruptive to the environment. Given the very favorable midlevel lapse rates on the 00Z DDC and OUN soundings, rich moisture, and strong instability and deep-layer shear, a 30%/CIG1 wind area was added from southwest KS into central OK.