MIAMI, Fla. – The extremely active 2020 Atlantic hurricane season came to an end Monday and coastal communities are breathing a sigh of relief.
However, while the hurricane season officially concludes on Nov. 30, that doesn’t necessarily mean the United States is out of the woods. The National Oceanic and Atmospheric Administration (NOAA) says tropical storms may continue to develop past that day.
Even without more storms, this season has been historic. We saw a record-breaking 30 named storms and 12 landfalling storms in the continental U.S., according to the NOAA. Before this year, the 2005 season held the record for the most named storms, with 28.
Of this season’s 30 named storms, 13 of them became hurricanes, meaning winds were 74 mph or greater. Six of those were considered major hurricanes, with winds reaching at least 111 mph: Laura, Teddy, Delta, Epsilon, Eta, and Iota.
Because the 2020 season got off to an early and rapid pace, officials quickly exhausted the 21-name Atlantic list when Wilfred formed in September.
So, for only the second time in history, the Greek alphabet was used for the remainder of the season, extending through the ninth name in the list, Iota.
“The 2020 Atlantic hurricane season ramped up quickly and broke records across the board,” said Neil Jacobs, Ph.D, acting NOAA administrator. “Our investments in research, forecast models, and computer technology allowed forecasters at the National Weather Service, and its National Hurricane Center, to issue forecasts with increasing accuracy, resulting in the advanced lead time needed to ensure that decision makers and communities were ready and responsive.”
NOAA says this was the fifth consecutive year with an above-normal Atlantic hurricane season, with 18 above-normal seasons out of the past 26.
Scientists attribute the increase in activity to the warm phase of the Atlantic Multi-Decadal Oscillation (AMO), which NOAA says began in 1995 and has favored more, stronger and longer-lasting storms. These kinds of eras have historically lasted about 25 to 40 years.
“As we correctly predicted, an interrelated set of atmospheric and oceanic conditions linked to the warm AMO were again present this year. These included warmer-than-average Atlantic sea surface temperatures and a stronger west African monsoon, along with much weaker vertical wind shear and wind patterns coming off of Africa that were more favorable for storm development. These conditions, combined with La Nina, helped make this record-breaking, extremely active hurricane season possible,” said Gerry Bell, Ph.D, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center.
Looking forward, the 2021 hurricane season will officially begin on June 1 and NOAA will issue its initial seasonal outlook in May.