How Hurricane Helene became a deadly disaster in six states

Some hurricanes are remembered for his or her wind damage or rainfall. Others due to their coastal flooding. Hurricane Helene was a stew of all the above and more. Its near-record size, storm surge, winds and rainfall combined to make Helene an almost unimaginable disaster that stretched greater than 500 miles inland from the Florida coast.

At least 230 people died as Helene through Florida, Georgia, South Carolina, North Carolina, Tennessee and Virginia flooded cities, destroyed roads and bridges And Houses swept away.

In Florida, the storm surge from Helene caused damage to a whole lot of kilometers of coastline. As residents began the cleanup and restoration work there, one other dangerous hurricane was on the method to them. Some of the identical areas hit hard by Helene on September 26, 2024 – including Tampa Bay and Cedar Key – could experience flooding again Hurricane Miltonexpected to land on October ninth.

Most of Helene's victims were removed from the coast and were caught by surprise when the storm dumped greater than 20 inches of rain on the mountains, quickly turning streams and rivers into torrential torrents.

I study hurricane history as a geographer and climatologist in one in every of these hardest hit states, South Carolina. Helene was by far the deadliest inland hurricane of all time. surpass Hurricane Agnes In 1972, 128 people died within the northeastern United States. And it was the third commonest within the continental US because the start of the operational forecast within the Sixties, after hurricanes Katrina (2005) and Camille (1969).

Meteorologists routinely assess three most important components of hurricanes: wind intensity, storm surge and rain. Here you’ll be able to see how these elements, together with Helene's enormous size and forward speed, made the storm way more destructive than its wind speed alone suggested.

Helene's destructive winds

Helene was undoubtedly the one The strongest hurricane to hit Florida's Big Bend Area north of Tampa since 1851. It made landfall late on September 26 near Perry, Florida a Category 4 hurricane with sustained winds of 140 miles per hour.

The storm rapid forward movement — it flew northward about 30 miles per hour after landing — and its size meant Helene's winds were still strong because it reached Georgia and South Carolina, areas that rarely experience such damaging winds. In the 2 states, greater than two million households lost power, greater than 1 / 4 of 1,000,000 of them still without power per week after the storm.

Valdosta, in southern Georgia, was hit by near Category 2 winds, with speeds around 90 to 95 miles per hour. The city has experienced only just a few hurricanes within the last century, including Idalia in 2023. Augusta, on the opposite side of Georgia near the South Carolina border, experienced a sustained tropical storm Wind gusts as much as 69 miles per hour.

Storm surge almost record-breaking

Helene's size was a vital factor. The hurricane was huge – about 400 miles wide, similar in size to Hurricane KatrinaAnd are amongst the biggest to ever hit land within the continental US

This size contributed to Helene's destructive storm surge. Hurricanes push toward the ocean, making a storm surge that may inundate the coast with water several feet above normal sea level. Large, strong storms impact a bigger area of ​​ocean over an extended time frame and construct up a bigger storm surge.

Helene's storm surge reached its peak about 15 feet within the Big Bend areain line with initial estimates. This would make it one in every of the best storm surges recorded within the region because the mid-Nineteenth century. Field surveys will take several weeks to confirm elevation.

Cedar Key, Florida, about 50 miles east of central Helene, had one Storm surge of roughly 9.3 feetwhich could be the best within the history of the twentieth century. Three major storm surges have been reported on this area up to now: 1896, at 12.5 feetAnd 1842 and 1848, each at about 15 feet.

Tampa Bay, nearly 200 miles south of Helene's center, experienced a destructive storm surge of greater than 6 feet. The Tampa area has seen worse, including a 15-foot storm surge in 1848but Helene's damage there was still widespread. Twelve people near Tampa died within the storm.

Rain and floods within the mountains

Much of Helene's most devastating impact occurred far inland because the storm moved up the mountains.

Normally, fast-moving storms present a lower threat of rain, but Helene was a serious exception. In the southern Blue Ridge Mountains, Helene's rain was enhanced by the terrain and the so-called orographic uplift. When a storm is forced to climb up a mountainside, the air cools and condenses, causing more precipitation to fall.

In the mountains, precipitation flows quickly into streams and rivers. Asheville, North Carolina fast-growing city with around 95,000 inhabitantslies in a bowl in mountainous terrain. This made it and other nearby towns very vulnerable to high river flows and extreme flooding. What made matters worse was that the world just before Helene was already saturated by a storm.

The French Broad River crested at 24.67 feet at Asheville, crushing the previous river 1916 record of twenty-two feetAlso brought on by remnants of a hurricane.

In South Carolina, the storm was so large that its rain bands covered your complete state. The National Weather Service at Greenville-Spartanburg reported that 8 to 2 feet of rain fell within the state of South Carolina.

Atlanta received 11.2 inches set a record inside 48 hours.

Assessing Hurricane Risk in a Warming World

Helene's devastation is a vital reminder that hurricanes can’t be judged based on wind speed alone. The commonly used one Saffir-Simpson scaleswhich classifies storms into categories 1-5 relies totally on wind intensity. Helene was classified as a Category 4 storm, but its damage was comparable to a number of the most destructive hurricanes in history.

As the climate warms, the chance of hurricanes changes. Warmer ocean water fuels hurricanes, and warmer air can hold more moisture, resulting in stronger, more destructive storms. The exceptional rainfall in Helene and the implications may very well be an indication of future hurricanes.