The technical definition of rapid intensification is when a storm’s maximum sustained winds increase by at least 35 mph in 24 hours. This season, storm after storm outperformed this baseline. This includes Hurricane Iota, which intensified at the astonishing rate of 80 mph in 24 hours, before slamming into the coast of northeastern Nicaragua late Monday night.
Rapid intensification typically occurs in high-end hurricanes that reach Category 3 or above. Scientists now say this is happening more frequently, as storms are given a turbo boost from rising ocean temperatures. During the 2020 hurricane season, the waters of the Atlantic were unusually mild, the result of human-caused global warming superimposed atop natural climate cycles.
The increase in rapidly intensifying storms is “not surprising,” said Suzana Camargo, a hurricane researcher at the Lamont-Doherty Earth Observatory at Columbia University, because human-caused climate change is expected to increase the occurrence of these particularly dangerous storms, most prone to explosive development.
According to Kerry Emanuel, a hurricane scientist at MIT, the 2020 Atlantic season provides a warning: The increasing tendency for hurricanes to rapidly intensify is a better gauge for how climate change is influencing them rather than how strong they ultimately get.