Global heating makes intense storms twice as likely, data shows

As Hurricane Milton surges through Florida, fuelled by a record-hot Gulf of Mexico, a new analysis has shown how the Gulf's heat that worsened last month's Hurricane Helene was 200 to 500 times more likely because of human-caused global heating.

- Oliver Milman ,Jonathan Watts Edward Helmore

Milton was last night expected to double its wind field with up to 15ft (4.5 metres) of storm surge and crash into a low-lying stretch of the Florida coast in the early hours of today.

Described as the "storm of a century", Milton turned north-east yesterday about 300 miles (480km) south-west of Tampa, heading towards heavily populated and highly vulnerable communities, including St Petersburg and Sarasota. It was expected to weaken slightly when it made landfall to a category 4 hurricane with sustained wind speeds of about 130mph.

Helene, one of the deadliest storms in US history, gathered pace over the Gulf before crashing ashore with 140mph winds last month.

The new analysis found climate heating increased by 10% the amount of rainfall hurled down by Helene, which left more than 220 people dead across six states as it barrelled north two weeks ago, flattening and drowning towns, tearing up roads and severing water supplies. It also made Helene's winds about 13mph, or 11%, more intense.

The burning of fossil fuels has made storms as severe as Hurricane Helene about 2.5 times more likely than they were in the pre-industrial age, the multinational group of scientists at the World Weather Attribution group stated. Should the world warm by 2C above this pre-industrial level, which will occur without major cuts to emissions, storms such as Helene will get a further 10% more rainfall, the study found.

"The heat that human activities are adding to the atmosphere and oceans is like steroids for hurricanes," said Bernadette Woods Placky, chief meteorologist at Climate Central, part of the attribution group. She added that storms such as Helene and Milton were becoming "explosive" because of excess heat.