La Niña, the periodic cooling of Pacific Ocean waters, has finally arrived, but forecasters predict it is weak and unlikely to cause as many weather problems as typically seen.
Why It Matters
La Niña and its opposing climate pattern El Niño can impact weather, wildfires, ecosystems and economies worldwide, according to the National Oceanic and Atmospheric Administration (NOAA).
What To Know
The last El Niño, the periodic warming of Pacific Ocean waters, finished in June 2024. NOAA forecasters have been expecting La Niña for months. The previous La Niña concluded in 2023 after an abnormal three-year stretch.
Michelle L'Heureux, head of NOAA's El Niño team, told The Associated Press (AP), that the warming of the world's ocean in recent years may have influenced La Niña's late arrival.
However, the exact cause of La Niña's late arrival has yet to be determined.
"It's totally not clear why this La Niña is so late to form, and I have no doubt it's going to be a topic of a lot of research," L'Heureux told the AP.
What Is El Niño And La Niña?
El Niño and La Niña are opposing climate patterns that disrupt normal conditions in the Pacific Ocean. During normal conditions, trade winds blowing west along the equator take warm water from South America toward Asia.
During El Niño events, trade winds weaken and warm water is pushed toward the west coast of the Americas. La Niña events are when stronger-than-usual trade winds push warm water toward Asia.
What Weather Problems Can Be Caused?
La Niña events usually cause drier weather in the Southern and Western United States. Meanwhile, the weather in parts of Indonesia, northern Australia and southern Africa tends to become wetter during La Niñas, according to L'Heureux.
On the flip side, El Niños tends to cause rainier weather in the U.S.
Usually, La Niñas brings more Atlantic hurricanes in the summer, but L'Heureux expects this current La Niña to dissipate by this upcoming summer.
What People Are Saying
Emily Becker, a research professor at the University of Miami and one of the main authors of NOAA's ENSO blog, told CNN that the current La Niña "is really getting started right at the time when it would normally be peaking [in strength] and beginning to dwindle."
What Happens Next
Becker wrote in a post about the current La Niña published Thursday on NOAA's ENSO blog, which monitors and forecasts El Niño and La Niña events and their impacts, "There's a 59% chance La Niña will persist through February–April, followed by a 60% chance of neutral conditions in March–May."
This article includes reporting from The Associated Press.
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