Hurricane Milton, like Hurricane Helene before it, is souped up on hot water in the Gulf of Mexico. Hurricanes need warm water to develop, with higher temperatures helping them gather strength. It's a risk that's growing with climate change, and we're already seeing the alarming consequences this hurricane season.
"The warmer the water is, effectively, the more fuel that is available for the storm engine to work with," says Scott Braun, a research meteorologist at NASA's Goddard Space Flight Center who specializes in hurricanes.
Milton exploded on October 7th, rapidly intensifying from a Category 1 to a Category 5 storm in near-record time. That day, it passed over waters in the Gulf of Mexico that might have felt similar to a hot bath. Sea surface temperatures reached roughly 88 degrees Fahrenheit (31 degrees Celsius). That's well above the temperature needed for a hurricane to develop, at least 79F (26C). Not only was the Gulf running a temperature, the unusually warm water also ran fairly deep, making it less likely the storm would churn up deeper, cooler waters.
It's not typically quite this hot this time of year. The 88 degree sea surface temperature is close to 4 degrees Fahrenheit (2C) above the long-term average. But every fraction of a degree matters when it comes to climate-related disasters like more intense storms.
"It's pretty darn warm," Braun says. "With the temperatures getting as warm as they are, and being above the long term average, you're basically getting more energy available to these storms than in the past."
More heat energy means the potential for stronger storms. Milton is the second major hurricane within two weeks to threaten Florida. Helene made landfall on September 26th as a Category 4 storm with wind speeds reaching 140 mph and a massive 15-foot storm surge.
Milton is forecast to make landfall on Florida's central west coast tonight as another major hurricane, with Category 3 or 4 strength on the Saffir-Simpson scale that tops out at Category 5. Milton ran into strong wind shear, weakening it as it approached Florida, which is why it's been downgraded from a Category 5 storm. Nevertheless, it'll be "an extremely dangerous major hurricane," the National Hurricane Center says. Tampa Bay could be hit with as high as a 12-foot storm surge.
"That storm surge is still the biggest issue that we're looking at. Any of you who went through Hurricane Helene, that was 4-6 feet and that was more devastation than I've seen in my life," City of Tampa Mayor Jane Castor said in a press conference today.
It's too soon to know exactly how much climate change might have influenced Milton's development. We do know that with Helene, the high sea surface temperatures along the storm's path were 200-500 times more likely as a result of greenhouse gas emissions from fossil fuels that are causing climate change, according to a study published today by an international group of researchers.
Off the bat, forecasters already expected a rough hurricane season this year with near-record heat in the Atlantic. With warmer than average sea surface temperatures lingering into the fall, coastal communities could once again find themselves in hot water before the Atlantic hurricane season comes to an end on November 30th.
With greenhouse gas emissions still on the rise and global average temperatures climbing, they could be feeling the heat again next season, too.