Hurricane Helene slammed into Florida’s Gulf coast on Thursday night with winds above 140mph (225km/h) and a 15ft (4.5m) storm surge. The storm caused deadly flooding as it dumped almost unprecedented amounts of rain through Georgia and the Carolinas, to Tennessee, Virginia and Kentucky.
Dozens were killed, communities wrecked or changed forever, and early estimates by insurance experts calculate losses at up to $160bn.
Before unleashing its full fury on the continental US, Helene, the eighth named storm of the 2024 Atlantic hurricane season, spent several days building up strength over the warm waters of the Gulf of Mexico.
Here is the timeline of one of the most deadly and costly hurricanes in recent memory:
Monday 23 September
The National Hurricane Center (NHC) in Miami warned that a broad area of pressure over the north-western Caribbean Sea, producing disorganized showers and thunderstorms, had “a high chance” of tropical development over the following two days. It posted tropical storm warnings for western Cuba and Mexico’s Yucatán peninsula, while noting the motion of the developing weather system was uncertain.
Tuesday 24 September
After being classified as a tropical storm, Helen’s forecast track began to come into focus. An NHC advisory projected it “accelerating toward the north-eastern Gulf coast through Thursday” after causing heavy rain, considerable flooding and mudslides across western Cuba overnight.
Anticipating a severe impact, Ron DeSantis, Florida’s governor, expanded an existing emergency order to 61 of his state’s 67 counties, while Brian Kemp, Georgia’s governor, did the same for all 159 of his.
Wednesday 25 September
Helene, upgraded during the morning to a category 1 hurricane, dumped substantial quantities of rain over the Mexican province of Quintana Roo, churning up beaches and flooding hotel rooms in the popular tourist towns of Cozumel and Cancún.
After sideswiping the Yucatán coast, Helene made a turn north, with the NHC stating it was “expected to rapidly intensify and grow in size over the eastern Gulf of Mexico”. Hurricane warnings were posted for Florida’s Big Bend, along with the first alerts for flash and urban flooding across much of the south-eastern US as far as the southern Appalachians and Tennessee Valley.
Thursday 26 September
Fueled by the ultra-warm waters of the Gulf of Mexico, Helene bulked up at a rapid pace through the day into a category 4 hurricane, with winds above 130mph, as it closed in on landfall on Florida’s Gulf coast.
The NHC said the storm surge and wind combination would be “catastrophic”, and warned the storm’s sheer size meant life-threatening conditions would penetrate far inland. Helene made landfall at Keaton Beach, Florida, at 11.10pm.
Friday 27 September
Residents along the Gulf coast awoke, if they were able to sleep, to scenes of devastation and destruction, with entire coastal communities swept away by the storm surge and countless buildings blown apart. First responders conducted thousands of water rescues in Florida, Georgia and the Carolinas, and large areas of metropolitan Atlanta were flooded.
Although downgraded again to a tropical storm, the center of Helene continued to cause havoc as it passed from Georgia into the Carolinas. More than 50 patients and staff were airlifted from the roof of a flooded hospital in Erwin, Tennessee.
Saturday 28 September
The scale of the emergency in North Carolina began to emerge, with authorities declaring that all roads in the west of the state could be considered closed due to flooding, damage, debris and fallen trees and power lines. The town of Asheville was largely underwater and cut off, with a local sheriff, Quentin Miller, declaring: “To say this caught us off-guard would be an understatement.”
The NHC issued its final bulletin on the now dissipated storm but warned widespread and significant river flooding was still ongoing across the southern Appalachians, and lengthy power outages were expected.