The Atlantic is churning with storms.
There are currently five tropical cyclones spinning in the Atlantic Ocean, making for some vivid satellite imagery of an aggressive, bustling sea. As of 2:00 p.m. EST, there are two hurricanes (including rapidly intensifying Sally, which is expected to make landfall Tuesday near the Louisiana-Mississippi border), two tropical storms (organized storms with sustained wind speeds of at least 39 mph), and one tropical depression (38 mph winds or less). It’s only the second time on record that five cyclones have simultaneously occurred in the Atlantic.
‘Tis the season for many storms: The peak of the active Atlantic hurricane period happens in late August through the first few weeks of September. During this time, hurricanes feed off of warm ocean waters, and the winds that tear storms apart are typically diminished. 2020, however, has already seen an extreme number of Atlantic storms, and could potentially break the record for the most named storms (which meet the criteria for a tropical storm) in a season. So far, 20 storms have formed, largely stoked by unusually warm ocean temperatures. Before 2020, the earliest 20th named storm formed way later, in early October.
“The number of storms is extraordinary,” said Falko Judt, a research meteorologist at the National Center for Atmospheric Research.
But, most of these storms (though certainly not Hurricane Laura!) have been short-lived or relatively weak. “At the moment it’s been quantity over quality,” Judt said, resulting in an average of total storm energy produced for this time of year. However, that can change quickly, Judt noted, and it soon might with active developments in the Atlantic.
In the coming weeks, conditions are ripe for robust storm activity. Warmer waters fuel hurricanes, as more water naturally evaporates into the air, giving storms energy and moisture to intensify. “Ocean temperatures are really warm,” said Brian Tang, an atmospheric scientist at the University of Albany. “There’s a lot of fuel for tropical cyclones to form and strengthen.”
What’s more, the “seeds” of many hurricanes — clusters of thunderstorms (called “tropical waves”) that form over Africa and then travel over the Atlantic — have been quite numerous. “There’s a lot of material coming over the Atlantic that could potentially become a hurricane,” said Judt.
“It’s almost like a train,” explained Tang. “Once they move off the African coast, the natural thing they want to do is continue to develop.”
Warmer oceans are often an important factor in allowing tropical hurricanes to grow stronger, but certainly not the only important ingredient. As 2020 shows, a storm can form but not pick up much steam. Other factors, like opposing winds ripping a storm apart, can diminish a cyclone.
But, overall, warmer waters boost the odds for storm formation. “That signal alone usually portends an active season,” explained Tang. More hurricane fuel means a greater likelihood of storms becoming cyclones, and then strengthening into hurricanes.
Overall, global oceans are absorbing nearly unfathomable amounts of heat as they soak up over 90 percent of the warmth created by human-caused climate change. Since 1900, the ocean’s surface has warmed by nearly 2 degrees Fahrenheit (1 degree Celsius). As the planet continues to warm in the coming decades and beyond, hurricane researchers don’t expect more hurricanes overall. However, they expect hurricanes to grow more intense, meaning higher wind speeds and more damaging and dangerous storms.
All it takes is one potent storm to upend lives. Just look at the continued fallout from Hurricane Laura in August. The Atlantic storm season has largely seen (relatively) weaker storms this year, but the story could change, dramatically.
“We’ll see what the rest of the season holds,” said Tang. “Obviously, you don’t want to call a game at halftime.”