Forecasters said Arlene, the Atlantic hurricane season's first named tropical storm, could become a weak hurricane before making landfall in the Deep South late Saturday.
Arlene was then expected to move northward along the Mississippi-Alabama line, possibly reaching Tennessee by Sunday afternoon.
Tropical storm warnings and hurricane watches were posted from Florida's Panhandle to Louisiana's southeastern tip, as Arlene's top sustained winds reached 70 mph, up from 45 mph earlier in the day. The wind speed was likely to increase, but forecasters said the biggest impact would be heavy rain.
Arlene would become a hurricane if its sustained winds hit 74 mph.
In the Florida Panhandle, the Coast Guard said one of its helicopters rescued five crewmembers of a fishing trawler that was taking on water in 12-foot seas off Cape San Blas. A Russian exchange student died after being pulled from the waves off Miami Beach, officials said.
Residents in flood-prone areas were urged to move to higher ground. Several western Panhandle counties urged tens of thousands of people to leave. In the vulnerable marshes south of New Orleans, bulldozers were moved into place in case water from a storm surge broke through a levee.
While Arlene is the first named storm of the Atlantic hurricane season, the memories of last season are still fresh for Floridians, reports Carey Codd of CBS Station WFOR from Pompano Beach, Fla.
In Pensacola Beach, where many residents are still living in government trailers because of damage from last year's Hurricane Ivan, residents eyed the forecast warily.
Margie Wassner, 57, said she planned to ride out Arlene with friends inland in Pensacola.
"It's pretty scary to me. I just kept hoping that we wouldn't have anything, but I don't know. It's awfully early in the year to be having this," she said.
Jeff Jackson, a real estate agent in Gulf Shores, Ala., worried that Arlene's rain could undo some of the beach erosion repairs under way in his town since February.
"Coming so close to Ivan, it's got people a little edgy," he said.
In Homestead, Fla., where hurricanes have been known to hit like a curse, people know how to prepare, Codd reports.
"We have our shutters, we have our supplies, so we'll be fine," said Elaine Padilla.
They are even stocking up on supplies in Alabama, Codd added.
Arlene passed Cuba's westernmost tip early Friday, bringing heavy rain, gusty winds and rough seas to the region. By Friday night, Arlene was centered about 295 miles south-southeast of Pensacola and moving toward shore at about 18 mph. Tropical storm force winds extended up to 150 miles, mainly to the north and east of the center.
The Florida Panhandle was battered last year by Ivan, one of the four hurricanes to strike the state within a few weeks. Florida was also struck by Charley, Frances and Jeanne, and together the four storms caused about 130 deaths in the United States and were blamed for $22 billion in insured damage.
Hurricane season began June 1 and ends Nov. 30.