Already deluged by a stubborn cyclone that wouldn't move, northern Florida could get another 6 to 12 inches of rain over the next two days as Tropical Storm Debby hovers in the northern Gulf of Mexico.
The storm could also produce more tornadoes across Florida on Tuesday, the National Hurricane Center said.
As of late Monday night, Debby was centered about 35 miles south of Apalachicola, Florida, the weather agency said. The sprawling storm was creeping northeast at 2 mph, packing maximum sustained winds of 45 mph along the way.
A tropical storm warning is in effect for the Gulf coast of Florida from Mexico Beach to Englewood.
Debby has stalled multiple times in the Gulf of Mexico, dumping up to 5 inches of rain per hour on parts of the Florida Panhandle.
The storm already has been blamed for one death in Venus, Florida, about 100 miles southeast of Tampa, when a woman died while trying to shelter her 3-year-old daughter during a tornado. That Sunday twister struck Heather Town's home and flung the 32-year-old about 200 feet into the surrounding woods, the Highlands County Sheriff's Office said Monday.
Neighbors found her still cradling her 3-year-old daughter, who was being treated at a Tampa hospital,
"She never let go of her little one even in death," Highland County Sheriff Susan Benton said.
Another twister hit St. Pete Beach on Sunday night.
Laura Miller wedged herself between her refrigerator and a kitchen pantry as the tornado passed.
"We heard the proverbial noise -- the train," Miller said. "The transformer blew, the windows started busting out. It was just very chaotic, all the glass flying, the debris flying into the house. It was pretty intense."
Magalie Caragiorgio said Monday that she had been stuck in her home in New Port Richey, near St. Petersburg, since Sunday because of flooding and hasn't been able to get to her job as a nurse.
"It's unnerving because you can't do anything," she said. "I guess I wasn't prepared. I wasn't expecting to be flooded out like this."
Citing the threat of heavy rainfall and potential tornadoes, Florida Gov. Rick Scott declared a state of emergency Monday "so we can coordinate the use of all state resources to make sure we can respond promptly if anything happens."
Debby has followed an unpredictable path since forming over the weekend. Storm warnings once stretched as far west as Morgan City, Louisiana, before shifting eastward on Sunday afternoon and Monday. That raised concerns for crews working on 596 manned oil and gas production platforms throughout the Gulf, run by various companies.
Shell, BP and ExxonMobil began evacuating workers from offshore rigs on Sunday, but BP and Shell had made plans to return to those platforms as Debby turned toward Florida.
CNN's Dave Hennen, Sarah Dillingham, Meridith Edwards, Kim Segal and Ashley Hayes contributed to this report.