A huge clash between unseasonably warm temperatures and bitter cold set the stage for a severe weather outbreak on Friday. The first wave hit parts of Missouri and Illinois around midday and early afternoon. A second wave hit the far south during the evening. Both sets of tornadoes caused fatalities.
Detailed tornado path and damage surveys: Missouri/Illinois Southern states
(This same system, although in a much weaker state, brought us the steady rain on New Year's Eve into Saturday morning.)
A full tally about all the severe weather items can be found here.