Batten down the hatches for another nasty hurricane season.
Nearly every natural force and a bunch of human-caused ones—more than just climate change—have turned the last several Atlantic hurricane seasons into deadly and expensive whoppers. The season that starts Wednesday looks like another note in a record-breaking refrain because all those ingredients for disaster are still going strong, experts warn.
They say these factors point to but don’t quite promise more trouble ahead: the natural climate event La Nina, human-caused climate change, warmer ocean waters, the Gulf of Mexico’s deep hot Loop Current, increased storminess in Africa, cleaner skies, a multi-decade active storm cycle and massive development of property along the coast.
“It’s everything and the kitchen sink,” Colorado State University hurricane researcher Phil Klotzbach said.
In the past two years, forecasters ran out of names for storms. It’s been a costly rogue’s gallery of major hurricanes—with winds of at least 111 mph (179 kph)—striking land in the past five years: Harvey, Irma, Maria, Florence, Michael, Dorian, Humberto, Laura, Teddy, Delta, Zeta, Eta, Iota, Grace and Ida.
“That’s the pattern that we’ve been locked into. And what a statistic to think about: From 2017 to 2021, more Category four and five (hurricanes) made U.S. landfall than from 1963 to 2016,” National Hurricane Center Director Ken Graham said in an Associated Press interview in front of two hurricane-hunter planes that fly into the storms.
Graham, echoing most experts and every pre-season forecast, said “we’ve got another busy one” coming. Last year, the Atlantic set a record for six above average hurricane seasons in a row, smashing the old record of three in a row, and forecasters predict a seventh.
The only contrary sign is that for the first time since 2014, a storm didn’t form before the official June 1 start of the hurricane season, but forecasters are watching the Eastern Pacific’s record-setting Hurricane Agatha that looks likely to cross over land and reform as Alex in the Gulf of Mexico later this week.
Here’s what may make the Atlantic chaotic this season:
One of the biggest influences on Atlantic hurricane seasons occurs half a world away in the temporarily cooling waters of the equatorial Pacific, the natural cyclical phenomenon called La Nina, the more dangerous for the United States flip side to El Nino.
La Nina alters weather across the world, including making hurricane development in the Atlantic more likely. It starts with the Sahel region of Africa, where the seeds of the many of the strongest mid-season hurricanes, called Cape Verde storms, form. That often dry region is wet and stormy in La Nina and that helps with early formation.
One weather feature that can decapitate storms or prevent them from forming in the first place is high cross winds called shear. But La Nina pretty much deadens shear, which is “a huge factor” for more storm activity, University of Albany hurricane researcher Kristen Corbosiero said.