Treacherous Hurricane Helene is expected to make landfall Thursday evening on Florida’s northwestern coast and then continue on to torment parts of Georgia, the Carolinas and Tennessee with heavy rain, flash floods and gusty winds. While Helene will likely weaken as it moves inland, its “fast forward speed will allow strong, damaging winds, especially in gusts, to penetrate well inland across the southeastern United States,” including in the southern Appalachian Mountains, the National Weather Service’s hurricane center said Thursday. Less severe 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 — are raising questions about the Fujiwhara Effect, a rare weather event. What is the Fujiwhara Effect? The National Weather Service defines the Fujiwhara Effect as “a binary interaction where tropical cyclones within a certain distance ..
. of each other begin to rotate about a common midpoint.” That means the two storms interact with and are shaped by one another, sometimes even combining into one storm.
The concept was born out of the interaction between typhoons in the Pacific Ocean, said Peter Mullinax, the acting Warning Coordination Meteorologist with the National Oceanic and Atmospheric Administration’s Weather Prediction Center. It was first identified over a century ago by Sakuhei Fujiwhara, a meteorologist in Tokyo, who published his findings about .
