Hurricane Delta, gaining strength as it bears down on the U.S. Gulf Coast, is the latest and nastiest in a recent flurry of rapidly intensifying Atlantic hurricanes that scientists largely blame on global warming.
Earlier, before hitting Mexico’s Yucatan Peninsula and temporarily losing strength, Delta set a record for going from a 35 mph (56 kph) unnamed tropical depression to a monstrous 140 mph (225 kph) Category 4 storm in just 36 hours, beating a mark set in 2000, according to University of Colorado weather data scientist Sam Lillo.
“We’ve certainly been seeing a lot of that in the last few years,” said National Oceanic and Atmospheric Administration climate and hurricane scientist Jim Kossin. “It’s more likely that a storm will rapidly intensify now than it did in the 1980s ... A lot of that has to do with human-caused climate change.”
Over the past couple decades, meteorologists have been increasingly worried about storms that just blow up from nothing to a whopper, just like Delta. They created an official threshold for this dangerous rapid intensification — a storm gaining 35 mph (56 kph) in wind speed in just 24 hours.
Delta is the sixth storm this year and the second in a week to reach the threshold, Lillo calculated.
Hurricanes Hannah, Laura, Sally and Teddy and tropical storm Gamma all gained at least 35 mph (56 kph) in strength in 24 hours. And a seventh storm, Marco, just missed the mark. Laura, which jumped 65 mph (105 kph) in the day before landfall, tied the record for the biggest rapid intensification in the Gulf of Mexico, said former hurricane hunter meteorologist Jeff Masters.
The run of killer hurricanes in 2017 featured a lot of rapid intensification, especially Harvey, Kossin said.
This is not only happening more often, it is more dangerous, said MIT hurricane scientist Kerry Emanuel. Hurricane damage doesn’t just rise with wind speed, it goes up exponentially, Masters said.