Flood warnings as well as tornado watches and warnings were in effect around the region.
The lightening strike happened in Desoto County in north Mississippi and gave the person inside "a pretty good jolt" but the injuries were not life threatening, said Bob Storey, director of the county's emergency management agency. The resident was taken to a nearby hospital as a precaution.
In south Mississippi, what may have been a funnel cloud was spotted in Pike County and several homes, trees and power lines in the area were damaged, said Carlene Statham, assistant director of Pike County Civil Defense. There were no immediate reports of injuries and officials were working to confirm if it was indeed a funnel cloud, Statham said.
She said the damage at one home was caused when "the wind picked up the back porch and threw it on top of the house."
Hail ranging in size from golf balls to nickels was reported in areas of central and south-central Mississippi, said Mike Edmonston, a senior meteorologist with the National Weather Service.
There were no reports of major damage in Mississippi, but coastal Jackson County remained under a tornado warning, Katherine Gunby, a spokeswoman with the Mississippi Emergency Management Agency, said.
In St. Tammany Parish, a suburban New Orleans area on the north shore of Lake Pontchartrain, most of the attention was on the Pearl River, which crested near the town of Pearl River around 6 a.m. at 19.2 feet. That was above flood stage but a few inches below the 19.5 foot crest that had been predicted, easing the threat to low-lying properties a bit.
Water from the Pearl River covered roads and low-lying land Wednesday and early Thursday. Only one house was reported to have taken on water but officials were worried high winds from the afternoon thunderstorms could push water into homes or across other roads.
"There's several low lying subdivisions we're watching very carefully" parish spokeswoman Suzanne Stymiest said.
Parish officials stood ready to rescue anyone cut off by flood waters and Louisiana Gov. Bobby Jindal scheduled an afternoon visit to survey the area.
Meanwhile, a line of violent thunderstorms moved through the western Florida Panhandle leaving about foot of water on some low-lying streets in the downtown Pensacola business district. Flooding was reported elsewhere in the Panhandle including in Panama City where officials blocked off streets and limited other streets to one lane.
The National Weather Service issued flood warnings for the Tallahassee area and cities around Florida's central Panhandle.
"Our primary concern today is more flash flooding," said public safety director Dino Villani of Okaloosa County, which includes Fort Walton Beach. "Very little rain can cause a lot of problems."
Villani said officials were closely monitoring the development of storms after his county's swift water rescue team helped 15 residents from waterlogged homes after flash floods Saturday.
The Blackwater River, which runs through the Panhandle's Santa Rosa County, was expected to crest at 8 feet Thursday afternoon, the same height it reached Monday. Emergency officials urged residents along that river to take precautions.
All along the low-lying Gulf Coast on an arc from Florida to Louisiana, authorities were watching.
School officials in Enterprise, Ala., canceled classes Thursday as a precaution, mindful of a tornado that killed eight students at a high school there two years ago. Several other Alabama school systems said they would release students earlier than usual Thursday before the brunt of the system arrives.
"Everybody here is still a little antsy," said School Superintendent Jim Reese, alluding to the deadly March 2007 tornado. "We really give it a lot of thought."
Associated Press Writer Mel