ST. CLAIR COUNTY – St. Clair County emergency officials activated outdoor warning sirens across the county Monday afternoon, May 4, 2026, after a report of a possible tornado in Smithton near a school. The National Weather Service in St. Louis later said the decision was based on visible storm rotation that did not appear organized enough to produce a tornado on the ground.
St. Clair County 911 received the report at 2:43 p.m. Monday, May 4, 2026, according to the St. Clair County Emergency Management Agency. The agency said contact was made with Smithton Police, who “confirmed the observation and provided additional information as to its current location and path of travel.”
Officials then made “a determination … to conduct a county-wide activation of the Outdoor Warning Sirens based upon the confirmed Public Safety sighting.”
The emergency management agency said it contacted the National Weather Service through a direct communications channel and shared information about the report and the siren activation. “Shortly thereafter, they issued a Severe Thunderstorm Warning with a ‘Tornado Possible’ tag,” the agency said.
Jared Maples, a meteorologist with the National Weather Service in St. Louis, said there was “definitely some rotation,” but added there was “no verification of damage or tornado occurring.” He described what was observed as “a wall cloud rotating.”
Maples said some factors argued against a tornado forming. He cited a “high cloud basis 4,000 feet or so” and said that “typically when looking for a tornadic environment, the cloud base needs to be lower than that.” He added that the storm “did have rotation, but it was broad enough to be visible to the naked eye and didn’t produce anything.”
In its statement, the emergency management agency said the situation required “quick decisions and actions based upon the information immediately available,” noting that some residents questioned the use of sirens. In contrast, others would have objected if sirens had not been activated. The agency said it also sent a countywide message through its Everbridge notification platform explaining the activation.
The agency said that when the National Weather Service issues a Tornado Warning, a polygon identifying the threatened area is transmitted electronically and “only those sirens are activated.” When there is a public safety sighting without a Tornado Warning, the agency said, “that shape does not exist and thus requires the countywide activation, such as what occurred today.”
