Tropical Storm Isaias was located about 55 miles southeast of Fort Pierce as of 11 a.m. ET.
The storm has maximum sustained winds of 65 mph. As it battered Grand Bahama Island early Sunday, a tropical storm warning was in effect from Jupiter Inlet, Florida, to Surf City, North Carolina. A tropical storm watch continues up the coast to Duck, North Carolina.
The wind and rain seemed to be dying down in Freeport, Bahamas, but not before giving Sidneka Munroe a scare. Heavy rains brought floodwaters up to 3 feet high, she told CNN, and if the storm had been any stronger or longer, she fears, it would've damaged her and her family's home.
"It was pretty terrifying, not knowing what to expect. The area we live in only started flooding since Dorian (in 2019), so the first sign of sunlight, it was necessary to see how bad the flooding was. This storm brought a lot of rain, for sure."
Forecasts indicate Isaias will not regain hurricane strength. Its center is expected to remain five to 10 miles off the coast as it moves north along Florida, but it could make landfall at any point Sunday, forecasts say.
A storm surge watch is also in effect from Edisto Beach, South Carolina, to Cape Fear North Carolina, while a storm surge of up to 4 feet is expected in portions of the Carolinas.
Forecasts show the storm making landfall between Charleston, South Carolina, and Myrtle Beach by Monday evening.
The storm will also dump up to 6 inches of water over parts of the state, and up to 7 inches in parts of the Carolinas and mid-Atlantic states. As it treks along the coast, Northeast Florida and coastal Georgia will see up to 4 inches of rain.
"Heavy rainfall from Isaias could result in potentially life-threatening flash flooding in the Bahamas and flash and urban flooding along the East Coast of the United States," according to the National Hurricane Center.
As Gov. Ron DeSantis warned, many Floridians were left without power. About 27,400 customers were experiencing outages; Palm Beach County being the hardest hit with almost 10,000 customers losing electricity, according to Florida Power & Light's outage map.
The utility has 10,000 workers ready to respond, the governor said before the storm's winds hit the coast.
North Carolina Gov. Roy Cooper authorized up to 150 members of the state's National Guard to be used if needed, his office said. The storm's center could affect the state early Tuesday.
In South Carolina, where the governor hasn't ordered an emergency declaration, some local governments are gearing up for what the storm could bring.
In Virginia, the governor said high winds and flooding will likely impact parts of the state.
CNN's Melissa Alonso, Brandon Miller, Rob Shackelford, Haley Brink and Amanda Jackson contributed to this report.