The National Weather Service’s hurricane center warned Thursday that Hurricane Helene will “penetrate well inland across the southeastern United States” after making landfall in Florida.
Tropical storm warnings were posted as far north as North Carolina.
The unusual reach as far north and inland as forecasters expect — and the potential impacts — is raising questions about the Fujiwhara Effect, a rare weather event where two storms rotate around a shared midpoint.
But Hurricane Helene isn’t interacting with another tropical storm at surface level, so it’s not technically an example of the Fujiwhara Effect. Instead, Helene is feeling the effects of a low-pressure weather system in the upper levels of the atmosphere.
The potential impact is still severe: The hurricane center has warned of prolonged power outages, downed trees and dangerous flooding miles away from the Florida coastline in parts of Georgia, the Carolinas and Tennessee.
Emergency officials in the North Carolina mountains are warning that heavy rains before Hurricane Helene even arrives have set the stage for potentially historic flooding.
The French Broad River and Swannanoa River, which run in and around Asheville and then south, are already predicted to break 100-year-old records Friday into Saturday. The flooding could be worse than in 2004 when water rose to car rooftops in Biltmore Village just outside the gates of the historic Biltmore estate built by George Vanderbilt.
“This is a potentially historic event with catastrophic, deadly consequences. This is not a maybe. This is on track to happen. So please, please take every precaution to take yourself out of harm’s way,” Buncombe County Emergency Services Director Taylor Jones said.
Seven inches of rain has already fallen in Asheville while some other areas have seen even more. All of the water is flowing downhill out of the mountains.
Mudslides are also a danger as swiftly flowing rivers and runoffs cut their own channels and bring down rocks, trees and other debris, said Andrew Kimball, a meteorologist with the National Weather Service in Greer, South Carolina.
