Tropical Storm Helene is expected to hit Florida’s Gulf Coast as a powerful hurricane later Thursday, in what could be the strongest storm to hit the U.S. in more than a year.

The storm is expected to strengthen to a Category 3 hurricane as it moves across the Gulf of Mexico.

moving from the coast of Mexico’s Yucatán Peninsula into the Gulf of Mexico, where it “will rapidly intensify to a major hurricane and increase in size in the eastern Gulf of Mexico (with) the potential for life-threatening storm surge along (the) entire west coast of Florida and the Big Bend area,” the National Hurricane Center said Wednesday morning.

According to the center, which is part of a federal agency, Helene is expected to produce winds stronger than 90 percent of other major hurricanes. The wind and rain bands are expected to extend more than 140 miles (225 kilometers) east of the eye.

Weather experts predicted early Wednesday morning that the storm would strengthen from a 45 mph (72 km/h) tropical storm to a Category 3 hurricane in less than 48 hours.

On its current track, the storm’s powerful core could pass directly over Florida’s state capital, Tallahassee. Hurricane and tropical storm warnings have been issued for the state’s west coast, from the Florida Keys and inland to Orlando, as well as for most of the east coast, and up through the so-called Big Bend coast and the Tallahassee area, as the coast then extends west into the Florida Panhandle.

Evacuations of thousands of people south of Tallahassee were underway Wednesday morning, and Joe Biden declared a state of emergency for Florida on Tuesday afternoon, pledging federal resources before the storm hit.

Florida Governor Ron DeSantis expanded the state of emergency to 61 of Florida’s 67 counties and mandatory evacuations will take place in the Big Bend area, where the highest storm surges are expected.

At a news conference Tuesday morning, DeSantis said the state had deployed the Florida National Guard, search and rescue teams and Florida Fish and Game teams to respond. The U.S. Federal Emergency Management Agency also deployed teams.

“You can hide from the wind,” DeSantis added. “But it’s the water that can be very, very devastating if you stay there when you’re told to evacuate.”

Kevin Guthrie, director of the Federal Emergency Management Agency, said Helene will be a very large storm, even compared to recent storms, warning that the storm “could be nearly twice the size of Debby and Idalia, with potentially a stronger core.”

Jamie Rhome, deputy director of the hurricane center, said, “The wind gusts are going to be tremendous with this system, and it’s actually going to carve a path across much of the Florida peninsula, including the heavily traveled I-4 corridor.”

Further north, Georgia Gov. Brian Kemp also declared a state of emergency and directed management teams to “prepare for and dispatch resources well in advance of the storm’s arrival. Remain vigilant and stay safe,” he said on X.

The storm is rapidly intensifying as Gulf water temperatures rise to 90 degrees Fahrenheit. Hurricane forecasters had expected an unusually busy season, but that hasn’t happened. This has allowed storm-friendly sea temperatures to rise uninterrupted, fueling Helene’s strength, driven by the climate crisis that is rapidly warming seas and is believed to be making storms more intense.

When Helene makes landfall in the United States, which is expected to happen Thursday night or Friday morning, it will be the fourth hurricane to make landfall in the U.S. this year and the fifth to hit Florida since 2022.