Timeline of Florence as slow-moving, deadly storm batters Carolinas

Since coming ashore more than 24 hours ago, Florence has wrecked havoc on the Carolinas as the hurricane-turned-tropical storm slowly crept further inland.

By the afternoon of Sunday, Sept. 16, the storm had caused at least 15 deaths.

Here's a look at when Florence first formed, its deadly impact and where the storm is forecast to go next.

Aug. 30

The National Weather Service announced that a potential tropical cyclone had formed in the eastern Atlantic Ocean, packing 30 mph maximum sustained winds.

At the time, the weather system had an 80 percent chance of developing into a tropical cyclone over the next 48 hours.

Aug. 31

The weather system developed into a tropical depression, with peak wind speeds near 35 mph, according to the National Weather Service.

At the time, the system was forecast to pass just south of the Cape Verde Islands that night before moving over the open eastern Atlantic in the coming days.

Sept. 1

The weather system developed into a tropical storm, dubbed Florence, with peak wind speeds near 40 mph, according to the National Weather Service.

Sept. 4

The National Weather Service announced that Tropical Storm Florence had developed into a hurricane, packing 75 mph maximum sustained winds.

It was the third hurricane to form during the 2018 Atlantic hurricane season.

By the end of the day, Florence had strengthened to a Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. The National Weather Service said the storm, carrying maximum sustained winds near 100 mph, was "stronger than anticipated."

Sept. 5

The National Weather Service announced that Florence had become a "major hurricane," the first of the 2018 Atlantic hurricane season.

Florence seesawed in strength throughout the day and night, from a Category 3 to a 4 then back to a 3. During that time, peak wind speeds reached 130 mph.

The storm was forecast to gradually weaken over the next several hours.

Sept. 6

Florence clung to hurricane status as it continued to reduce in strength.

By the end of the day, the National Weather Service announced that the system had weakened back to a tropical storm but was expected to restrengthen back to a hurricane over the coming weekend.

Sept. 9

Florence strengthened back into a hurricane and was forecast to "rapidly intensify into a major hurricane" by the following night, the National Weather Service said.

Sept. 10

The National Weather Service announced that Florence had "rapidly" strengthened back into a "major hurricane," first a Category 3 and then a 4, with peak wind speeds at 140 mph.

The storm was expected to intensify further and be an "extremely dangerous major hurricane" through landfall later in the week, the National Weather Service said.

The White House announced that President Donald Trump had approved an emergency declaration for both North and South Carolina in anticipation of Hurricane Florence, authorizing the Federal Emergency Management Agency (FEMA) to coordinate all disaster relief efforts.

Sept. 12

Florence's peak wind speeds gradually fell to 110 mph by the end of the day, downgrading the hurricane to a Category 2.

But the size of the storm's wind field increased as the "large hurricane" neared the coast of the southeastern United States, the National Weather Service said. Hurricane-force winds extended outward up to 80 miles from the center and tropical-storm-force winds extended outward up to 195 miles.

Sept. 14

Florence made landfall as a Category 1 hurricane near Wrightsville Beach, North Carolina, at 7:15 a.m. local time, according to the National Weather Service. The storm was moving at just 6 mph at the time and had maximum sustained winds near 90 mph.

The slow-moving hurricane lashed eastern North Carolina with relentless rain and wind throughout the day, causing catastrophic flooding in some areas that saw as much as 40 inches of rainfall.

Footage taken from the ground in hard-hit areas showed flooded streets, downed trees, scattered debris and storefronts blown out. The number of customers without power in the Tar Heel State quickly soared past half a million.

A number of residents who chose not to evacuate, or tried to do so too late, were stranded in their homes, cars and even on rooftops amid rising floodwaters. First responders, volunteers and even private citizens rescued hundreds of people -- and some animals -- throughout the day, and many more still await rescue services.

Reports of deaths from the storm began to come in.

Among the dead were a mother and her baby died after a tree fell on their home in Wilmington, North Carolina. The father was transported to a nearby hospital with injuries, police said.

A third person died in North Carolina's coastal Pender County, where an official called it a medical fatality but did not elaborate.

Another two people died in Kinston, North Carolina, officials said. A 78-year-old man was electrocuted at his home while attempting to connect two extension cords outside in the rain. A 77-year-old is believed to have died after he was blown away by heavy winds while attempting to check on his hunting dogs.

A woman in South Carolina died after her car struck a tree, the state's highway patrol told ABC News.

Two more people died in Duplin County, North Carolina, "due to flash flooding and swift water on roadways," officials said. An 81-year-old man fell and struck his head in Wayne County, and a husband and wife died in a house fire Cumberland.

By the end of the day, Florence was downgraded to a tropical storm and was moving slowly west into South Carolina at just 3 mph.

Sept. 15

Tropical Storm Florence continued crawling westward across eastern South Carolina. The storm is expected to gradually weaken to a tropical depression by the end of the day, according to the National Weather Service. But the torrential rain shows no signs of letting up anytime soon.

Florence is expected to dump another 14 to 20 inches of rain on southern and central parts of North Carolina into far northeast South Carolina. This will continue to produce "catastrophic flash flooding and prolonged significant river flooding," the National Weather Service said.

Rainfall totals could reach 40 inches along the coastal areas of southeast North Carolina.

"We just don't want people to think this thing is over because it's not," North Carolina Gov. Roy Cooper said at a press conference Saturday.

We're going to see areas of flooding that have not flooded before," he said, adding, "I have a real concern about that."

The National Weather Service also warned that a few tornadoes are possible in southeastern North Carolina and northeastern South Carolina throughout the day and night.

Nearly a million customers were without power in both North and South Carolina by 8:45 a.m. local time. Thousands of residents remained in shelters.

The White House announced that President Donald Trump had approved a disaster declaration for North Carolina, which makes federal aid available to supplement state funding for temporary housing and home repairs, among other forms of assistance.

Florence is forecast to take a northwest turn on Sunday and then head northward through the Ohio Valley by Monday, according to the National Weather Service.