A possible tornado touched down in eastern Missouri on Wednesday, the National Weather Service said.
The weather service also said there was a moderate risk of severe thunderstorms across portions of northern Oklahoma, southeastern Kansas and western Missouri. There was a lower risk of severe thunderstorms from the southern Plains to the Ohio Valley and from north Texas to the Appalachian Mountains.
A tornado warning was in effect for four counties in western Oklahoma. Forecasters said a severe thunderstorm was moving east at 35 mph and was capable of producing hail as big as tennis balls.
The weather service indicated a tornado may have touched down in the small town of Potosi, Missouri, about 70 miles from St. Louis.
CNN affiliate KMOV reported that it had received reports of wind damage and flooding in the town.
One Instagram user there posted a photo of a fallen tree.
Aerial footage also showed damage to roofs and one street overtaken by water.
Not far away from Potosi, Shyler and Christin Strube in Leadington posted an Instagram picture of some unusual dark clouds.
And a Twitter user in Farmington got bad news when he went out to his car.
“They weren’t kidding when they said baseball size (hail),” Kevin Knox wrote.