UPDATE 4:03pm: Severe thunderstorm warning for City of STL and St. Louis County. It does not include West County to the west of I-270.
There is rotation near Stegman in northern Jefferson Co. This may move into southern St. Louis Co. It is moving NNE. Radar at 3:54pm
The tornado index is an extreme high value of 7 in SE Missouri and northern Arkansas. Note the line of thunderstorms in that area. The risk of major tornadoes is extremely high!