Some hurricanes are notorious for their wind damage or heavy rainfall, while others are remembered for coastal flooding. Hurricane Helene, however, combined all these elements and more, resulting in an unprecedented disaster that impacted areas over 500 miles inland from the Florida coast.
The storm tragically claimed at least 230 lives across several states, including Florida, Georgia, South Carolina, North Carolina, Tennessee, and Virginia, as it flooded towns, destroyed roads and bridges, and obliterated homes.
In Florida, Helene’s storm surge wreaked havoc along hundreds of miles of coastline. Just as residents began their recovery efforts, they faced the looming threat of another hurricane. Areas already hit hard by Helene on September 26, 2024—including Tampa Bay and Cedar Key—were at risk of additional flooding from Hurricane Milton, anticipated to make landfall as early as October 9.
Most of Helene’s casualties occurred far from the coast, where many were caught off guard by over 20 inches of rain that transformed streams and rivers into torrents.
As a geographer and climatologist studying hurricane history in South Carolina, I can attest that Helene was the deadliest inland hurricane on record, surpassing Hurricane Agnes in 1972, which resulted in 128 fatalities in the northeastern U.S. It ranks as the third deadliest in the continental U.S. since operational forecasting began in the 1960s, following Hurricanes Katrina (2005) and Camille (1969).
Meteorologists typically analyze three key components of hurricanes: wind intensity, storm surge, and rainfall. Helene’s vast size and rapid forward movement contributed to its extraordinary destructiveness, overshadowing what its wind speed might suggest.
Helene made landfall near Perry, Florida, late on September 26, as a Category 4 hurricane with sustained winds of 140 mph—the strongest to strike Florida’s Big Bend region since 1851. Its rapid northward movement of about 30 mph after landfall meant that damaging winds extended far into Georgia and South Carolina, areas not accustomed to such intensity. Over 2 million homes lost power across these states, with more than a quarter-million still in the dark a week later.
In southern Georgia, Valdosta experienced winds approaching Category 2 intensity, around 90 to 95 mph. Augusta, near the South Carolina border, recorded tropical storm wind gusts up to 69 mph.
Helene’s immense size played a crucial role in its storm surge. Measuring about 400 miles across—comparable to Hurricane Katrina—it was among the largest hurricanes to make landfall in the continental U.S. This scale allowed for a significant storm surge, with estimates peaking around 15 feet in the Big Bend area, potentially marking it as one of the highest surges on record in the region.
Cedar Key, located approximately 50 miles east of Helene’s center, recorded a storm surge of about 9.3 feet, the highest in its 20th-century history. The Tampa Bay area experienced a destructive surge exceeding 6 feet, leading to widespread damage, including 12 fatalities nearby.
The most severe impacts of Helene were felt far inland, particularly as the storm moved through mountainous regions. Typically, fast-moving storms pose a lower risk of heavy rain, but Helene defied this trend. In the southern Blue Ridge Mountains, the terrain amplified rainfall through orographic uplift, causing excessive precipitation.
The rainfall rapidly filled streams and rivers. Asheville, North Carolina, situated in a basin surrounded by mountains, faced significant flooding, exacerbated by pre-existing saturation from an earlier storm. The French Broad River reached 24.67 feet, shattering the previous record of 22 feet set in 1916.
In South Carolina, Helene’s expansive rain bands covered the entire state, with the National Weather Service reporting rainfall totals of 8 to 24 inches. Atlanta recorded a remarkable 11.2 inches within just 48 hours, setting a new record.
Evaluating Hurricane Risk in a Warming World
Helene’s devastation serves as a stark reminder that hurricanes cannot be evaluated solely by their wind speed. The Saffir-Simpson scale, which classifies storms from Categories 1 to 5 based on wind intensity, does not capture the full scope of a storm’s potential damage. Despite being categorized as a Category 4 hurricane, Helene’s impact rivaled that of some of history’s most destructive storms.
As the climate warms, the nature of hurricane risk is evolving. Warmer ocean waters fuel hurricane intensity, while increased atmospheric moisture can lead to heavier rainfall. Helene’s extraordinary precipitation and consequences may represent a troubling trend for future hurricanes.