Dozens of tornado and severe thunderstorm warnings were issued Wednesday in parts of Arkansas, Illinois, Indiana, Missouri and Mississippi as storms hit those and other states in the evening. Numerous possible twisters were reported in the South overnight, particularly in Tennessee and Kentucky.

At least six people were killed in western Tennessee, Missouri and Indiana in the first wave on Wednesday and early Thursday that spun off powerful tornadoes.

The National Weather Service says a "multi-day catastrophic and potentially historic" storm is expected to impact multiple states. Thousands have lost power in Missouri and other states, and a person was killed Wednesday evening in the southeast part of the state.