The outer bands of Tropical Storm Debby lashed Florida on Sunday, spurring two apparent tornadoes in the central part of the state that killed one woman, a county spokeswoman said.

Gloria Rybinski, emergency operations spokeswoman for Highland County, said the twisters destroyed four homes in the southern end of the county and damaged others.

The woman was found dead in a home in Venus, located in the middle of the state roughly between Port St. Lucie and Sarasota, Rybinski said. In addition, a child in one of the affected homes was injured and transported to a hospital for treatment.

The slowly moving center of Debby remains in the Gulf of Mexico, though it's already pounding the region with torrential rain.

High winds prompted authorities to shut down the Sunshine Skyway bridge on Interstate 275 connecting St. Petersburg and Bradenton, Florida, said Elizabeth LaRotonda with St. Petersburg police.

"We are receiving reports of drivers needing to be rescued in downtown Clearwater and reports of water reaching the bumpers of cars in Gulfport," CNN affiliate Bay News 9 reported. Drivers were also reported stranded in other areas, with some intersections closed, the station said.

A large swath of the state was under a tornado watch and a flood watch Sunday afternoon, as forecasters warned of heavy rainfall. Several tornado warnings were issued.

Louisiana's governor declared a state of emergency Sunday, but the National Hurricane Center Sunday afternoon canceled a tropical storm warning from the mouth of the Pearl River westward to Morgan City, Louisiana.

The new forecast track showed Debby remaining a tropical storm as it moves northward and makes landfall, possibly Thursday, on the Florida Panhandle. However, forecasters warned Debby's track remained uncertain and said the "new official track remains a low-confidence forecast."

Computer models showed a wide variety of places where the storm may make landfall, from the upper Texas coast to the Florida Panhandle, said Dave Hennen, CNN senior meteorologist.

A tropical storm warning remained in effect from the Mississippi-Alabama border eastward to the Suwannee River, Florida. And a tropical storm watch was extended southward from the Suwannee River to Englewood, Florida.

At 4 p.m. (5 p.m. ET), the center of Debby was located about 205 miles east-southeast of the mouth of the Mississippi River and about 100 miles south-southwest of Apalachicola, Florida. Packing 60-mph winds with higher gusts, it was moving northeast at about 3 mph. Some slight strengthening was forecast over the next 48 hours, forecasters said.

"Tropical storm conditions are already near or over portions of the northeast Gulf Coast and are expected to reach the remainder of the warning area by tonight," the Miami-based hurricane center said.

It described Debby as a "sprawling system," with tropical storm-force winds of at least 39 mph stretching some 200 miles from the storm's center.

Earlier Sunday, sustained winds of 37 mph with gusts to 43 mph were reported at Bald Point, Florida, about 45 miles south of Tallahassee, the hurricane center said.

The combination of a storm surge and the tide could cause 4 to 6 feet of flooding at Florida's Apalachee Bay, forecasters said. Florida's west coast, south of Apalachee Bay, and coastal Mississippi eastward to Apalachee Bay could see 2 to 4 feet of flooding, while southeastern Louisiana could see 1 to 3 feet.

Debby is expected to dump 5 to 10 inches of rain over much of the Florida panhandle, northern and central Florida and southeastern Georgia, with isolated amounts of 15 to 20 inches possible in some islolated areas, the hurricane center said.

"Given the recent heavy rainfall and wet soil conditions, these additional amounts will exacerbate the threat of flooding across portions of northern Florida and southern Alabama," forecasters said.

Alabama, Mississippi, southeastern Louisiana and southern Florida were forecast to receive 2 to 4 inches of rain, with up to 6 inches possible in some areas.

Tornadoes were also possible through Sunday night over west and central Florida.

Because of the storm's uncertain track, some Louisiana officials weren't taking any chances.

In Plaquemines Parish, the state's southernmost parish, authorities were utilizing baskets and tubes in an effort to keep Highway 23 -- the parish's main evacuation and emergency route -- free of water should the 4-foot levees be topped, said Billy Nungesser, parish president.

"We want to be ahead of that as a precautionary measure," Nungesser said. The area is forecast to receive a storm surge of 2 to 4 feet, he said -- "with a direct hit, if it goes up a little bit more, we'll have those levees topped."

Officials were also sandbagging the levees as an additional precaution, he said.

Following his declaration, Louisiana Gov. Bobby Jindal left Republican presidential candidate Mitt Romney's weekend retreat in Park City, Utah, early to return to Louisiana, spokesman Kyle Plotkin said.

In St. Mary Parish along the central Louisiana coast, officials were in "watch and wait" mode, according to Duval Arthur, the parish's emergency preparedness director.

"The way this storm is moving, so slow, it's really kind of hard to make any plans, to start any plans ... it's changed on us actually three times," he said.

Officials are planning to issue street-flooding warnings in recreational areas located on the water, he said. "As this storm gets closer, we're going to have 3-to-4-foot higher than normal tides."

Louisiana's Terrebonne Parish and Lafourche Parish also issued precautionary states of emergency Sunday.

BP said Sunday it was closely monitoring the progress of Debby and that all the company's oil and natural gas production in the Gulf was to be shut down by midday.