The tumultuous 2017 Atlantic hurricane season proved to be one of the most active years on record, with 17 named storms and six major hurricanes.
But it can get quite a bit stormier than that.
In a study published Wednesday in the journal Science Advances, researchers looked at hurricane seasons dating back to 1851 and found that it’s quite unlikely any Atlantic hurricane season will surpass the 28 named storms and 15 hurricanes produced during the 2005 season, infamous for the deadly Hurricane Katrina that struck the Gulf Coast.
“To me, it makes sense that 2005 is about as many as you can get,” Phil Klotzbach, an atmospheric scientist at Colorado State University who had no role in the study, said in an interview.
Using sophisticated weather models, the research team ran over 6,000 simulations of a wide range of weather conditions — such as temperature, winds, and air pressure — that our present climate can produce.
They found that there’s less than a 3.2 percent chance that any combination of conditions might result in more than 28 storms forming in any given year, which they took to mean 28 cyclones is pretty much the Atlantic Ocean’s maximum storm potential.
This could be useful information for both Atlantic nations and the Bermuda Institute of Ocean Sciences’ Risk Prediction Initiative, the natural catastrophe research group that funded the study.
But, it’s not really the number of storms that matters for people on the ground.
“At the end of the day, if you have 28 weak pieces of junk, no one cares,” said Klotzbach. “It’s the Irmas people care about.”
Last year, Hurricane Irma made landfall several times in the Caribbean, including leveling 95 percent of the structures on the island of Barbuda, before hitting Florida and causing severe flooding.
Wind and water damage from the storm in the U.S. alone amounted to an estimated $50 billion, and, in total, Irma killed 47 people, though many more indirect deaths were reported.
It could be a quiet storm year overall, said Klotzbach, but “obviously all it takes is one or two high-profile storms to make the headlines and cause a lot of damage.”
How about future storms in a changing climate?
This study looked exclusively at what our present climate could produce in the Atlantic.
Running sophisticated models on powerful computers has time and budget constraints, so the researchers restricted their research to the present.
“Of course, future climate is very important to consider,” Sally Lavender, the study’s lead author and researcher at Australia’s Commonwealth Scientific and Industrial Research Organization’s Division of Marine and Atmospheric Research, said over email.
Yet, a changing climate doesn’t necessarily mean more hurricanes, like it does more heat waves and wildfires.
“Based on work by others it is not at all clear if we could expect an increase in the numbers of tropical cyclones in the North Atlantic,” said Lavender.
“Most models don’t show the number of storms increasing,” said Klotzbach. “In general, the number of storms is probably not going to change that much.”
Still, future storms may carry more water, noted Klotzbach, or they may bring stronger winds, said Lavender.
There’s also strong evidence that storms are slowing down, which would mean considerably more flooding and destruction over the unlucky regions the storms stall over.
Even so, Klotzbach emphasized that we might as well focus on preparing for what could happen today.
In the 1940s, for example, five Category 4 and 5 storms (the highest rated storms) pummeled Florida over the course of six years. And with coastal development and massive population increases since then, we’re not prepared to deal with that sort of storm onslaught, said Klotzbach.
“We’re not prepared for what we have now,” he said. “When Category 5’s start hitting Florida again, it’s going to be bad.”