The most serious risk — a level 3 of 5 — exists for about 9 million people in parts of southern Mississippi, parts of the Florida Panhandle, southern and central Alabama and Georgia, and parts of South Carolina, the prediction center said.
Storms already were battering parts of Louisiana, Mississippi and Alabama Tuesday morning.
As the system moves east, the Atlanta area could see conditions deteriorate by 11 am ET and see strong storms into the afternoon.
The following cities will see their greatest chance of severe storms from 4 to 10 pm ET: Tallahassee, Florida; Savannah, Georgia; Charleston, South Carolina; and Charlotte, Raleigh and Wilmington in North Carolina.
More severe weather possible in the South on Wednesday
Tuesday’s severe weather is the latest in a series of storms that have battered the southern US for three weeks straight.
Many of the same areas that have seen severe weather over the past few weeks will be in threat of it again over the week ahead, the Storm Prediction Center’s Bill Bunting told CNN.
“The very moist air flowing northward from the Gulf of Mexico, which has helped the storms develop over the last few weeks, is once again what we will see this week,” Bunting said.
By Thursday, the threat diminishes, as the storms push off the East Coast. While the system is primarily bringing storms to the South, we will still see rain Thursday for much of the Eastern Seaboard.
Anywhere from Florida to New England will see rain, so Wednesday and Thursday could bring a few travel delays at some major airports as this system moves through.
CNN’s Dave Hennen, Gene Norman, Jennifer Gray, and Chris Boyette contributed to this report.