TALLAHASSEE, Fla. - Fast-moving Hurricane Helene is advancing across the Gulf of Mexico toward Florida.
Forecasters say it threatens an "unsurvivable" storm surge in parts of northwestern Florida, as well as damaging winds, rains and flash floods hundreds of miles inland across much of the southeastern United States.
The National Weather Service office in Tallahassee says storm surges could reach 20 feet in the state's northwest.
Landfall is expected Thursday evening.
Forecasters have also issued a hurricane warning far beyond the coast up into south central Georgia.
The governors of Florida, Georgia, North Carolina and South Carolina have all declared emergencies in their states.
Authorities say prolonged power outages, toppled trees and dangerous flooding are possible.