This hurricane season is confusing experts and defying forecasts. What the heck is going on here?

CNN
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It is the beginning of September – the stormiest part of the hurricane season. Meteorologists have predicted dire consequences: storm after storm, the most optimistic forecasts ever.

Instead, there is a rare and strange calm in the Atlantic that has confounded meteorologists and set back their expectations. And it could be a taste of what's to come as the planet warms.

Despite ideal conditions that led to forecasts of over 20 named storms early in the season, the immediate prospect of such a storm is slim, and none has formed in the Atlantic since Ernesto in mid-August – a streak unmatched in 56 years.

“If you had told me a month ago that nothing would develop after Ernesto, I wouldn't have believed you,” said Phil Klotzbach, a hurricane expert and scientist at Colorado State University. “It's really surprising.”

The strange season has been influenced by extreme atmospheric conditions that are a byproduct of climate change caused by fossil fuel pollution, experts said. And it may also offer a “glimpse” of more volatile storm behavior in the future, said Matthew Rosencrans, lead hurricane season forecaster at NOAA's Climate Prediction Center.

Scientists have long believed that global warming will ultimately lead to fewer but stronger storms. This trend has been confirmed this season.

Hurricane forecasters, including Klotzbach, had predicted that the shift from August to September would revive the hurricane season. Many widely used forecast models signaled the same thing. It didn't work out.

The ideal conditions for the formation of hurricanes – warm sea water, hardly any storm-damaging winds at high altitudes and plenty of moist air – are present, but the storms are not occurring. Less well-understood atmospheric factors have stood in the way, said Klotzbach, and they are related to global warming.

Take the extremely warm ocean waters, for example: The Atlantic was already near record-breakingly warm before the season began. This fueled the record-breaking Category 5 Hurricane Beryl, a hurricane of such immense strength so early in the season that it was considered a potential harbinger of a turbulent season to come.

But warm water cannot intensify storms if it does not get there in the first place.

Almost all hurricanes are formed by stormy weather off the coast of central Africa. Since about mid-summer, these hurricane populations have been pushed farther north than usual – even into one of the driest places on Earth – the Sahara. They have also left Africa much further north than usual and have therefore stunted. Dry, dusty air and cooler sea temperatures have combined to smother the storms here off the continent's northwest coast.

The northward shift could be related to the interaction between extremely warm water in the tropical Atlantic and a small area of ​​unusually cold water – a burgeoning Atlantic Niña – near the equator, say Klotzbach and his research group at the CSU.

The African monsoon is loaded with a lot of moisture, which can actually delay the development of tropical storms, a study published in June in the Journal of Advances in Modeling Earth Systems found. It turns out there's a Goldilocks zone for hurricanes – dry conditions deprive thunderstorms of the fuel they need, but too much of it can make them so chaotic that they can't organize into a cyclone. The moisture has to be just right.

“For the first time, we're seeing that this is actually the case,” said the study's lead author, Kelly Núñez Ocasio, who is also an associate professor at Texas A&M University. “We're seeing it right now in the Atlantic hurricane season.”

The scenario could occur more frequently as the Earth continues to warm because the atmosphere will retain more moisture. Further research is needed to definitively determine the change over time, warned Núñez Ocasio.

Due to the climate crisis, conditions at the Earth's surface and higher in the atmosphere are very warm. This also limits the available chaotic energy needed to form tropical systems.

In addition to warming at the surface, the highest layers of the troposphere – the layer of Earth where all life and most weather occurs – are also warming over time, according to a study published in the journal Nature in 2023. This trend could potentially cause storms in the Atlantic to be much more subdued during the hottest season, similar to what happened this year.

Because of the vagaries of the weather, there is no immediate threat of storms. If no storms form by the typical peak of hurricane season on September 10, it would be a quiet period at the height of the season, the likes of which has not been seen in nearly 100 years, according to hurricane expert Michael Lowry.

Nevertheless, experts warn that the season is not over yet and that there could soon be signs of life again.

More than 40% of all tropical activity in a typical season occurs after September 10, so there is ample precedent for storms to rejuvenate the Atlantic in the following months.

Klotzbach believes the season could pick up again in the second half of September if these limiting factors ease.

And as the season progresses, the area where storms form later in the hurricane season is moving closer to the Caribbean and the U.S. coast, including the Gulf of Mexico, where it's record-breakingly warm. Additionally, La Niña is expected to strengthen throughout the fall and could increase activity in October and November.

Those staying in tropical areas should not become complacent in view of the recent lull in activity.

The storms “will come back,” warned Klotzbach. “I still don't think this season will end well.”