La Nina is back, but it's weak and may be brief. Will it still amp up the Atlantic hurricane season?

Andrew Zinin
lead editor

La Niña, the cooler and at times costlier flip side of El Niño, has arrived to warp weather worldwide, meteorologists said Thursday. This natural weather phenomenon often turbocharges the Atlantic hurricane season, but this La Niña may be too weak and fleeting to cause much trouble.
In the United States, La Niña often means more precipitation—including possible snowstorms—in northern areas and winter dryness in the South. It can bring heavier rains in Indonesia, the Philippines, parts of Australia, Central America, northern South America and southeastern Africa. It also can mean drought in the Middle East, eastern Argentina, eastern China, Korea and southern Japan, meteorologists said.
A La Niña occurs when certain parts of the Central Pacific Ocean cool by half a degree Celsius (0.9 degrees Fahrenheit) compared to normal. The world had been flirting with one this year and the National Oceanic and Atmospheric Administration declared Thursday that La Niña conditions have formed. But it's likely to be not very strong and may disappear in the next few months, based on multi-factor computer model forecasts by NOAA and Columbia University, said Michelle L'Heureux, lead scientist on the NOAA team that studies both La Niña and El Niño.
"There is a three out of four chance it will remain a weak event," L'Heureux said in an email. "A weaker event tends to exert less of an influence on the global circulation, so it's possible there will be surprises ahead."

Surprising already describes the 2025 Atlantic hurricane season, which was forecast to be stronger than normal, but so far is a in activity. Traditionally, during a La Niña, there's a weakening of the wind shear that hampers hurricane formation and strengthening, allowing more and bigger storms, especially later in the year, such as late October and into early November and in the Caribbean, said University of Albany hurricane expert Brian Tang.
But Brian McNoldy, who studies tropical cyclones, sea level rise and extreme heat at the University of Miami, said he thinks this La Niña is too late and too little to do much.
The conditions, especially wind shear, favor more hurricane activity, yet it's not happening and long-range computer models don't show much forming for the next couple weeks, said Colorado State University hurricane expert Phil Klotzbach.

Winter a year ago had a similar weak La Niña but there were still some signs of its impact, L'Heureux said.
Some studies have shown that in the United States, La Niña can be more costly than its warmer El Niño cousin. A found that drought from La Niña cost U.S. agriculture between $2.2 billion to $6.5 billion, which is far more than the $1.5 billion cost of El Niño.
A cold La Niña is not always the more expensive version, but it is often the case, said research scientist Azhar Ehsan, who heads Columbia University's El Niño/La Niña forecasting.
© 2025 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.