2017 hurricane season follows year of extremes

Lead author Jennifer Collins, PhD, associate professor in the School of Geosciences at the University of South Florida in Tampa, FL, writes "Overall 2016 was notable for a series of extremes, some rarely and a few never before observed in the Atlantic basin, a potential harbinger of seasons to come in the face of ongoing global climate change."

"The 2016 North Atlantic Hurricane Season: A season of Extremes" examines 15 tropical storms, seven hurricanes and three intense hurricanes. The season was slightly above average when considering Accumulated Cyclone Energy (ACE), which the National Oceanic and Atmospheric Administration (NOAA) uses to measure cyclonic activity.

Hurricane Alex started the 2016 season in January, causing minor damage in the Azores. The season ended 318 days later in late November when Otto made landfall over southern Central America. Otto was record-breaking in location and intensity being a high-end Category 2 storm.

In October, Hurricane Matthew became a Category 5 at the southernmost latitude on record for the North Atlantic Ocean. It was the first Category 5 in almost a decade and ended the longest stretch without one since 1950. Matthew claimed more than 600 lives, mainly in Haiti, and caused $15 billion in damage.

Up until that point, conditions had been extremely dry. A dramatic change in relative humidity lead to the month generating more than 50% of the season's ACE. It's also the first October to have two Category 4 or stronger storms.