Tornado Warning NW Part of STL Metro

Purple = tornado warning. St. Louis is dense road network at right center part of image. Strong thunderstorm farther south is also moving toward STL area.

click to enlarge

There is a hook echo (tornado signature) in western St. Charles Co. and a tornado warning is in effect for the purple area.  There is also some rotation on the southern storm (arrow).

Update 7:23pm. Tornado warning on southern storm.