Spring is finally in full bloom, but some weather forecasters are already fast-forwarding a few months to hurricane season.
The Atlantic season spans from June through November, and because of a burgeoning El Niño, this year’s could diverge from the active seasons of much of the past decade, according to a new forecast from hurricane researchers at Colorado State University.
They are calling for a slightly below-average season consisting of 13 named storms — that means tropical storms and hurricanes. They expect six of those will become hurricanes and two will strengthen into Category 3 or stronger major hurricanes.
Only one Atlantic hurricane season since 2016 ended with a below-average number of storms: 2025. Last year saw 13 named storms, including five hurricanes, most notably Category 5 Melissa, which devastated Jamaica. CSU’s initial forecast of 17 storms overshot the mark, as did the official National Oceanic and Atmospheric Administration forecast.
The CSU experts last predicted a slightly below-average season in their initial forecast in 2023. But tropical activity that year, fueled by record warm oceans, ended up above-normal, defying almost all early forecasts.
Predicting the future so far in advance has pitfalls, especially in a world warming due to fossil fuel pollution, but CSU isn’t consulting a Magic 8 Ball.
They consult forecast models they’ve been fine-tuning for years that have been better at predictions than seasonal averages alone.
There are also some other significant signals — including the impending return of El Niño — that have given the forecasters slightly more confidence than normal that there will be less tropical activity overall, according to Phil Klotzbach, a senior research scientist and lead author of CSU’s forecast.
The El Niño of it all
The CSU forecast pinpoints El Niño as the “dominant factor” for the upcoming hurricane season.
The La Niña that’s been in place since the fall ended this month, giving way to so-called neutral conditions. El Niño is expected to build later this spring and officially commence mid-summer, according to NOAA’s latest forecast. That means El Niño will be in place for the peak of hurricane season, which spans mid-August to mid-October.
As a refresher: El Niño is a natural climate pattern marked by warmer than average water temperatures in the equatorial Pacific that also leads to changes in upper atmosphere patterns. Together, these factors influence weather globally.
Forecasters closely monitor El Niño and its cooler counterpart La Niña because they affect weather in a way that’s largely consistent and predictable well in advance — especially when the patterns are strong.
El Niño conditions typically lead to an increased amount of wind shear — a change in wind speed or direction with height — in the upper atmosphere over parts of the Atlantic basin. High amounts of wind shear can weaken storms by blowing apart their spin or prevent them from forming in the first place.
Even so, El Niño conditions do not guarantee a quieter hurricane season. They were in place during the peak of 2023’s season, but extremely warm ocean temperatures acted like rocket fuel, allowing systems to develop and thrive despite increased wind shear.
The exact timing and strength of El Niño will ultimately determine how much of an influence the pattern has on the season. There are early signs that El Niño could become quite strong, but it’s still too early to say that with any certainty.
Ocean temperatures matter
While El Niño signals the potential for a slightly below-average season, current ocean temperature trends are sending more of a mixed message.
Ocean temperatures are warmer than normal in the western tropical Atlantic, the part of the ocean closest to the Caribbean. In April, these temperatures typically “correlate well” to “busy” hurricane seasons, according to CSU.
But ocean temperatures are currently a bit cooler than normal in parts of the central and eastern tropical Atlantic, which is normally associated with “quieter” hurricane seasons, according to CSU.
Sea surface temperatures will warm through the spring and summer and eventually hit a peak around early September. The timing of the warmest water matters because it is every tropical system’s source of fuel.
Planet-warming fossil fuel pollution is tipping the scales toward hotter oceans that power more dangerous storms.
Scientists say unusually warm oceans will likely lead to more instances of storms rapidly intensifying, like four of last year’s hurricanes did. Three of the four hurricanes that underwent this explosive intensification ultimately became Category 5 monsters: Erin, Humberto and Melissa.
If ocean temperatures get hotter than expected, they could once again chip away at El Niño’s influence and leave the door open for a busier season.
“There is still a lot that can change between now and the peak of the season,” Klotzbach cautioned.
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