A Strange and Damaging Hurricane Season Comes to a Close
Forecasters Reflect on the Surprising Lull in Activity
A strange, damaging hurricane season comes to its official end Saturday, and forecasters are taking stock of its many surprises.
A Season of Unpredictability
"Every year there’s one or two things that make me scratch my head, and this year I was doing more head-scratching than normal," Philip Klotzbach, a meteorologist at Colorado State University who specializes in Atlantic hurricane forecasts, told NBC News.
A Busier Season than Expected
Most forecasters predicted a hyperactive hurricane season as early as April, with the National Oceanic and Atmospheric Administration issuing its highest-ever forecast. In the end, 18 named storms, 11 hurricanes, and five major hurricanes formed – at the lower end of the range most forecasters expected, though still an above-normal and "extremely active" season.
The Bizarre Pattern of the Season
What surprised researchers was the bizarre way the season played out. It got off to a roaring start when Hurricane Beryl became the first Category 5 storm seen in the Atlantic Ocean in June. But from mid-August through early September, all went quiet. That’s usually when the season reaches its peak – around September 10. But not a single named storm developed during those weeks, the first time since 1968 that has happened.
The Switch to a Busy Season
Just when researchers thought their forecasts were turning into busts, storm activity roared back to life and hurricanes Helen and Milton struck, causing billions in damage.
"It took your normal seasonal cycle and turned it on its head," Klotzbach said. "What stood out to me – it was like a switch flipped and it went completely off and completely on. It went from nothing to Helene and a bunch of storms in the east Atlantic and Milton."
The Factors Behind the Season’s Unpredictability
Researchers are studying what led to the strange pattern to boost their understanding of the factors that drive hurricanes and improve future forecasts. The reasons researchers predicted a busy, dangerous hurricane season this spring were record high ocean temperatures in the Atlantic and a likelihood that La Niña, a natural pattern of variability, would take hold. Ocean heat provides fuel for hurricanes, and it can enable them to intensify more quickly. La Niña is associated with hurricanes because it often decreases stability in the atmosphere.
The Investigation Continues
Researchers will spend the winter investigating which factors had the most influence via climate and weather models. "It’s an opportunity to learn, to look at the system and have the Earth teach us something new," he said.
Records Set This Season
Despite the midseason break from tropical storms, 2024 set several records. Five hurricanes made landfall in the continental U.S., tying several years for the second most in history, according to a review Klotzbach published. Helene was the strongest hurricane to ever strike Florida’s Big Bend. And seven hurricanes formed in the Atlantic after September 25, the most in recorded history.
The Impact of Climate Change
Research suggests climate change made Helene and Milton worse. Both hurricanes went through a rapid intensification process, in which a hurricane’s sustained wind speeds increase by at least 35 mph over 24 hours. The trend has become more common as global temperatures rise. What’s more, scientists who study the influence of climate change on weather found that rainfall in one-day events like Milton is now about 20% to 30% more intense because of climate change. The researchers, with the World Weather Attribution project, also determined that Milton’s wind speeds were most likely 10% stronger because of climate change’s influence. The group produced similar results for Hurricane Helene.
Conclusion
The 2024 hurricane season was a season of surprises, with a late-season surge in activity that caught many by surprise. As researchers continue to study the factors that contributed to this season’s unpredictability, they are learning more about the complexities of hurricane forecasting and the impact of climate change on the weather.
Frequently Asked Questions
Q: What were the predictions for the 2024 hurricane season?
A: Most forecasters predicted a hyperactive hurricane season, with the National Oceanic and Atmospheric Administration issuing its highest-ever forecast.
Q: How many named storms, hurricanes, and major hurricanes formed in the 2024 season?
A: 18 named storms, 11 hurricanes, and five major hurricanes formed.
Q: What was unusual about the 2024 hurricane season?
A: The season got off to a roaring start, but then went quiet from mid-August through early September, the first time since 1968 that this happened.
Q: What factors contributed to the season’s unpredictability?
A: Record high ocean temperatures, La Niña, and a shift in the African monsoon season all played a role.
Q: How did climate change impact the 2024 hurricane season?
A: Climate change made hurricanes Helene and Milton worse, with higher wind speeds and more intense rainfall due to global warming.
