Hurricane Risks Remain High in Atlantic Even as La Nina Fades

La Nina and its hold over global weather patterns has faded, but there’s little hope this will blunt Atlantic storms this hurricane season.

The cooling of the equatorial Pacific is known to wreak havoc the world over, causing droughts across the western U.S. and parts of South America, as well as bringing more rain to Indonesia and parts of Australia, and roiling energy and agriculture markets in the process. On Thursday, the U.S. Climate Prediction Center declared La Nina, which began in September, had ended.

As the Pacific returns to neutral from La Nina, the pressure will drop off, but both states lead to less wind shear, which allows hurricanes and tropical storms to grow stronger.

“Even if we end up with neutral as opposed to La Nina, we could still have a very active season,” said Phil Klotzbach, lead author of the Colorado State University seasonal Atlantic storm forecast. Some of the most active Atlantic seasons in recent years came during neutral conditions across the Pacific.

Thanks to La Nina, last year saw a record 30 storms named in the Atlantic, while the 30-year average is for 14 storms to form during hurricane season. For hurricane watchers across the Atlantic, it would take an El Nino, the warming of waters in the equatorial Pacific, to make a significant difference. El Nino causes winds to blow at different speeds or strengths at varying altitudes, ripping apart budding tropical storms and hurricanes, reducing the overall numbers.

“I like to describe it as a forcing, it is pushing on the atmosphere and causing the ripple effect,” said Michelle L’Heureux, a climate scientists with the U.S. Climate Prediction Center. “Neutral is the absence of that pushing effect.”

L’Heureux said there is a chance that La Nina could return sometime in November, December, and January, which is when it would have its greatest impact on U.S. weather.

©2021 Bloomberg L.P.

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