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All right. As if a pandemic weren't bad enough, this was the most active Atlantic hurricane season on record. The 2020 season ends today. All in all, there were 30 named hurricanes and tropical storms. NPR's Greg Allen reports.
GREG ALLEN, BYLINE: Here's another record - the last hurricane, Iota, was the latest in the season any storm reached Category 5 status. It slammed into Nicaragua and Honduras in mid-November. That was just 15 miles from where Eta, another major hurricane, hit two weeks earlier. Eta later made not one but two landfalls in Florida. Given the number of storms, the United States got off relatively lightly this year, even though the season set another record with 12 continental U.S. landfalls.
PHIL KLOTZBACH: We did not have any of these hurricanes make landfall in any major metropolitan areas.
ALLEN: Phil Klotzbach is a research scientist at Colorado State University in the Department of Atmospheric Science. Damage from hurricanes and tropical storms this year is estimated at between $35 and $40 billion, Klotzbach says, far below the more than $200 billion of 2017 with Harvey, Irma and Maria.
KLOTZBACH: Hurricane Laura back in August made landfall in southwest Louisiana, was a very, very significant hurricane for Lake Charles area. But had that storm gone 100 miles farther west and headed up towards Houston, obviously, the economic damage would have been much, much higher.
ALLEN: Hurricane Sally did some $5 billion in damage in September after coming ashore near the Alabama-Florida border. In August, Hurricane Isaias' wind and rain knocked out power for millions of people, from Florida to Connecticut. One reason this season was so active is La Nina. That's a weather pattern caused by the interaction of the ocean and atmosphere in the Pacific. Michael Mann, a scientist at Penn State University, says there's another important factor - ocean temperatures in the Atlantic, Caribbean and Gulf of Mexico set new records.
MICHAEL MANN: What we have this year is sort of a perfect storm - no pun intended - of very warm ocean waters and a La Nina pattern that reduces vertical wind shear, creating yet a more favorable environment for these storms to form.
ALLEN: Scientists say climate change is making hurricanes stronger, wetter and more damaging. Mann says it's simple thermodynamics. Hurricanes get their energy from the heat in the tropical oceans.
MANN: The warmer you make those oceans, the deeper you make that well of warm water beneath the surface, the more energy there is to intensify these storms into the sorts of monster hurricanes that we're seeing more and more of.
ALLEN: Scientists say, in keeping track of records, there's a major caveat. Modern forecasting relies on satellite imagery and aircraft, providing information that wasn't available in previous decades. In earlier years, forecasters would never know about many short-lived storms that didn't make landfall. Phil Klotzbach says in 1933, for example, when the U.S. weather bureau recorded 20 named storms.
KLOTZBACH: Obviously, in 1933, we didn't have satellites. We didn't have aircraft. So it's really hard to know how many storms we missed.
ALLEN: With so many storms this year, the National Hurricane Center went further into the Greek alphabet for names than ever before. But some meteorologists see a problem. The World Meteorological Organization, the WMO, says some particularly damaging storms this year, Eta and Iota, won't have their names retired. The letters remain part of the Greek alphabet and are available for future storms. James Franklin, former branch chief at the National Hurricane Center, says the issue also came up the only other time Greek letters were used - after the 2005 season.
JAMES FRANKLIN: The suggestion back in 2006 was to come up with an alternative list of regular names that could be used if the alphabet was exhausted. And that, of course, would make it very easy to retire a name.
ALLEN: It's an idea that's expected to come up once again the WMO meets in the spring. Greg Allen, NPR News, Miami.
(SOUNDBITE OF SUFJAN STEVENS AND LOWELL BRAMS' "THE RUNAROUND")
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