Fast-moving Hurricane Helene was advancing Thursday across the Gulf of Mexico toward Florida, threatening a “catastrophic” storm surge in northwestern parts of the state as well as tornadoes, damaging winds, rains and flash floods hundreds of miles inland across much of the southeastern U.S., forecasters said.

According to AP News:

Helene was upgraded Thursday morning to a Category 2 storm and is expected to be a major hurricane — meaning a Category 3 or higher — when it makes landfall on Florida’s northwestern coast Thursday evening. Tropical storm force winds already started hitting the state in advance. Hurricane warnings and flash flood warnings extended far beyond the coast up into south-central Georgia. The governors of Florida, Georgia, the Carolinas and Virginia have all declared emergencies in their states.

In Florida, Gov. Ron DeSantis said Thursday morning that models suggest Helene will make landfall further east, lessening the chances for a direct hit on the capital city of Tallahassee, whose metro has a population of around 395,000.

The shift has the storm aimed squarely at the sparsely-populated Big Bend area, where rain began to blow in Thursday morning along coastal U.S. Highway 98, which winds through fishing villages and vacation hideaways in this region where Florida’s panhandle and peninsula meet. Shuttered gas stations dotted the two-lane highway, their windows boarded up with plywood.

The National Weather Service office in Tallahassee forecast storm surges of up to 20 feet (6 meters) and warned they could be particularly “catastrophic and unsurvivable” in Florida’s Apalachee Bay. It added that high winds and heavy rains also posed risks.

“This forecast, if realized, is a nightmare surge scenario for Apalachee Bay,” the office said. “Please, please, please take any evacuation orders seriously!”

This stretch of Florida known as the Forgotten Coast has been largely spared by the widespread condo development and commercialization that dominates so many of Florida’s beach communities. The sparsely populated region is loved for its natural wonders — the vast stretches of salt marshes, tidal pools and barrier islands; the dwarf cypress trees of Tate’s Hell State Forest; and Wakulla Springs, considered one of the world’s largest and deepest freshwater springs.