Hurricane Helene made landfall in Florida's Big Bend region late Thursday as one of the most powerful storms to hit the state, raising fears of deaths, widespread damage and even worse floods than the severe deluge which had preceded its arrival.

Helene hit Florida packing sustained winds of around 130 mph (209 kph), the National Hurricane Center said, making it a powerful Category 4 storm. Even before it made landfall, the storm had flooded the Gulf Coast and knocked out power for at least 1 million customers in the state.

Officials pleaded with residents in the path of the storm to heed mandatory evacuation orders or face life-threatening conditions. Helene's surge - the wall of seawater pushed on land by hurricane-force winds - could rise to as much as 20 feet (6.1 meters) in some spots, as tall as a two-story house, the center's director, Michael Brennan, said in a video briefing.

"A really unsurvivable scenario is going to play out" in the coastal area, Brennan said, with water capable of destroying buildings and carrying cars pushing inland.

Strong rain bands were whipping parts of coastal Florida, and rainfall had already lashed Georgia, South Carolina, central and western North Carolina and portions of Tennessee. Atlanta, hundreds of miles north of Florida's Big Bend, was under a tropical storm warning.

Florida Governor Ron DeSantis told reporters late Thursday the hurricane had already caused one fatality. He gave no details.

In Pinellas County, which sits on a peninsula surrounded by Tampa Bay and the Gulf of Mexico, roads were already filling with water before noon. Officials warned the storm's impact could be as severe as last year's Hurricane Idalia, which flooded 1,500 homes in the low-lying coastal county.

Videos posted on the county's social media site showed some swamped beachside roads and water rising over boat docks.

Airports in Tampa, Tallahassee and St. Petersburg all suspended operations on Thursday.

Helene is expected to remain a full-fledged hurricane as it rolls through the Macon, Georgia, area on Friday, forecasters said. It could bring 12 inches (30.5 cm) of rain or more, potentially devastating the state's cotton and pecan crops, which are in the middle of harvesting season.

"The current forecast for Hurricane Helene suggests this storm will impact every part of our state," Georgia Governor Brian Kemp said.

After making landfall across the Florida coast, Helene is expected move more slowly over the Tennessee Valley on Friday and Saturday, the NHC said.

Item 1 of 10 Waves impact a house seawall as Hurricane Helene intensifies before its expected landfall on Florida’s Big Bend, in Eastpoint, Florida, U.S. September 26, 2024. REUTERS/Marco Bello

[1/10]Waves impact a house seawall as Hurricane Helene intensifies before its expected landfall on Florida’s Big Bend, in Eastpoint, Florida, U.S. September 26, 2024. REUTERS/Marco Bello Purchase Licensing Rights, opens new tab

WALL OF WATER

Storm surge was forecast to reach 15 to 20 feet (4.6 to 6.1 meters) in the Big Bend area of Florida's Panhandle region where the storm came ashore.

Numerous evacuations were ordered along Florida's Gulf Coast, including Sarasota and Charlotte counties.

Not everyone heeded the evacuation orders. In coastal Dunedin, Florida, about 25 miles west of Tampa, state ferry boat operator Ken Wood, 58, planned to ride out the storm with his 16-year-old cat, Andy.

"We're under orders, but I'm going to stay right here at the house," Wood told Reuters by telephone. "The storm looks like it'll be a bit west of us, but who knows? I'm sure it'll be interesting, to say the least."

In Taylor County, the Sheriff's Department asked residents who decided not to evacuate to write their names and dates of birth on their arms in ink - so that they could be identified in the case they lost their lives in the hurricane.

Reinsurance broker Gallagher Re said preliminary private insurance losses could reach $3 billion to $6 billion, with additional losses to federal insurance programs approaching a potential $1 billion.

Energy facilities along the U.S. Gulf Coast scaled back operations and evacuated some production sites.

The director of the Federal Emergency Management Agency, Deanne Criswell, said at a White House briefing that she would travel to Florida on Friday to assess the damage.

Helene was expected to dump up to 15 inches (38.1 cm) of rain in some isolated spots after making landfall in Florida, causing considerable flash and urban flooding, the hurricane center said.

"You need to prepare for prolonged (energy) outages. Those trees are going to come down in strong winds, block roads," National Hurricane Center Deputy Director Jamie Rhome said.