The northern Gulf of Mexico is a hotspot
Flickr / eutrophication&hypoxia
These keeps happening. Back in September 2018, the Weather Channel ran a story on the unexpectedly rapid intensification of Florence into a Category 4 hurricane, whose headline read in part, “We didn’t expect it to get so strong so soon.”
In 2017, Harvey spun up from a tropical depression to a Category 4 superstorm in two days, while that same year, Maria intensified explosively in one day from a Category 1 storm to Category 5 superstorm.
What’s going on?
Hurricanes draw their ferocious power from warm ocean waters. One of the ways hurricanes are weakened is the upwelling of colder, deeper water due to the hurricane’s own violent churning action.
But if the deeper water is also warm, it doesn’t weaken the hurricane and often continues to intensify it. As human-caused global warming continues decade after decade, not only do sea-surface temperatures rise, but the warming penetrates deeper into the ocean.
“Storms are intensifying at a much more rapid pace than they used to 25 years back,” explained the author of a 2012 study on hurricane intensification trends. “They are getting stronger more quickly and also [to a] higher category. The intensity as well as the rate of intensity is increasing.”
A 2015 study on the impact of sea-surface temperatures on the intensity of hurricanes in the North Atlantic found “intensification increases by 16 percent for every 1°C increase in mean SST.” And a 2016 study warned that “the vast majority (79 percent) of major storms” are rapid intensification storms,” and “the most intense storms” are those that undergo rapid intensification.