A storm that dumped up to 12 inches of rain in Louisiana and Mississippi moved into Alabama, Georgia, Tennessee and western North Carolina on Friday.
The National Weather Service posted flash flood watches and warnings for much of the South from Louisiana into southwest Virginia.
The storm system was blamed for a death in Louisiana earlier this week when a tree fell on a camper.
No deaths or serious injuries had been reported in Mississippi by early Friday, Glenn Flynn with the Mississippi Emergency Management Agency said in an email.
Forecasters said up to 5 inches of rain were possible in northern Alabama and central and north Georgia. A flood warning was also issued for Asheville, North Carolina.
Water flooded more than a dozen homes in St. Charles Parish, Louisiana, on Thursday.
A Trader Joe’s store in Metairie outside New Orleans lost power during the storm Thursday, prompting the chain to donate more than 10,000 pounds of perishable grocery items to the Second Harvest Food Bank.
Food bank spokesman Joe Vise said the refrigerated and frozen items will be distributed across 23 parishes in the state.
Teams were heading out in Mississippi on Friday to determine the extent of damage.
Three emergency shelters were set up in Forrest and Jones counties, but only a few people were in them early Friday, Flynn said.
The National Weather Service planned to check the Vicksburg area on Friday for evidence of a tornado, said forecaster Mike Edmunston in Jackson.
There had been at least two dozen water rescues in the Hattiesburg area, Edmunston said.