In Mississippi, officials say 12 people died Monday, nine in Winston County, where hard-hit Louisville is the county seat. Three others died in separate traffic incidents.
In Alabama, three people were reported dead, two in the northern part of the state and one in Tuscaloosa. There, officials say a University of Alabama student died Monday when he took shelter in a home's basement and a retaining wall collapsed on him.
Tennessee officials say two people died in a home when a suspected tornado hit Monday night.
On Sunday, 15 were killed as a tornado blasted through Arkansas. One person died in Oklahoma, and two in Iowa.