Hurricane Helene, a dangerous storm, is poised to hit Florida’s northwestern coast Thursday evening, with subsequent impacts expected in Georgia, the Carolinas, and Tennessee. Despite projections of weakening as it moves inland, Helene’s fast speed will bring strong, damaging winds and heavy rain to the southeastern U.S. Tropical storm warnings have been issued as far north as North Carolina.

As the storm’s reach extends northward and inland, questions about the rare Fujiwhara Effect have surfaced in the forecasting community. The National Weather Service defines this phenomenon as a binary interaction where tropical cyclones interact and rotate around a common midpoint.

While Hurricane Helene is not undergoing the Fujiwhara Effect with another storm, it is responding to a low-pressure system in its vicinity. This interaction is occurring in the upper levels of the atmosphere, not at the surface, steering Helene towards Tennessee, northern Georgia, and the lower Appalachia.

Though the Fujiwhara Effect is infrequent, interactions between tropical storms and atmospheric systems are more common. Notable instances include Storm Sandy in 2012, illustrating the impact of such phenomena on weather patterns.

The unique movement and size of Hurricane Helene, combined with pressure system interactions, are heightening the risk of severe weather warnings throughout the southeastern U.S. Flash flooding, landslides, and gusty winds are anticipated, potentially causing extensive damage and threats to safety.

The approaching storm’s impacts have prompted state emergencies in Florida, Georgia, the Carolinas, and Virginia. Helene is projected to bring catastrophic storm surge to northwestern Florida, with the National Weather Service predicting surges of up to 20 feet.

Helene first formed in the Caribbean Sea before affecting the Yucatán Peninsula and western Cuba, leaving destruction in its wake. Moving forward, residents in the path of the storm are advised to prepare for potential power outages, dangerous flooding, and hazardous conditions, even as Helene’s intensity may decrease as it progresses inland.