Where is La Niña? Why the climate troublemaker is making a late arrival for 2024

The long-promised La Niña climate pattern hasn't yet formed, but is still expected to within the next month or so, federal scientists announced Thursday.

Specifically, the Climate Prediction Center said there is a 60% chance that La Niña conditions will emerge by the end of November. And once it forms, it is expected to persist through January-March 2025.

Speaking about La Niña, climate scientist Michelle L'Heureux told USA TODAY the "onset is delayed ... It has not formed yet." She added the delayed onset could mean a weaker version of La Niña, if indeed it does form.

Another forecaster, AccuWeather's Jason Nicholls, agreed, noting, "It still looks like a weak La Niña will form over the coming months and should be short lived."

La Niña often creates weather patterns that increase hurricane activity in the Atlantic Basin , which if it forms could still affect the tail end of this year's season . It also affects winter weather in the U.S. and around the world.

What is La Niña?

La Niña is a natural climate pattern marked by cooler-than-average seawater in the central and eastern Pacific Ocean. When the water cools at least 0.9 degree Fahrenheit below average for three straight months, a La Niña is declared.

"While this may sound like a small change in temperature, it can cause significant changes in the weather patterns around the globe," said AccuWeather meteorologist Brian Lada.

It is one of the main drivers of weather in the United States, especially during the late fall, winter and early spring. It's the opposite to the more well-known El Niño, which occurs when Pacific Ocean water is at least 0.9 degree warmer than average for three months.

What might La Niña bring next winter?

A typical La Niña winter in the U.S. brings cold and snow to the Northwest and unusually dry conditions to most of the Southern states, according to the Climate Prediction Center . The Southeast and mid-Atlantic also tend to see higher-than-average temperatures during a La Niña winter.

New England and the Upper Midwest into New York tend to see lower-than-average temperatures, the Weather Channel said.

The National Oceanic and Atmospheric Administration will be releasing its official winter forecast Thursday, and L'Heureux said the likely La Niña will be a major part of the forecast.

Other forecasters also were watching for La Nina: Earlier this week, Japan's weather bureau said that although there were no signs of El Niño or La Niña phenomena at this moment, characteristics of La Niña were approaching.

What is El Niño? What is ENSO-Neutral?

El Niño is a natural climate pattern in which sea surface temperatures in the central and eastern tropical Pacific Ocean are warmer than average. It occurs, on average, every two to seven years.

Its name means "the little boy," or "Christ child" in Spanish. El Niño originally was recognized by fishermen off the coast of South America in the 1600s with the appearance of unusually warm water in the Pacific Ocean around Christmas.

The entire natural climate cycle is officially known as El Niño – Southern Oscillation, called ENSO by scientists. The cycle swings between warmer and cooler seawater in a region along the equator in the tropical Pacific. La Niña is marked by cooler-than-average ocean water in the region.

When water temperatures are neither unusually warm nor cool, "ENSO-neutral" conditions are declared.

That's what's happening now: "Waters in the eastern and central Pacific Ocean near the equator have remained at near-average temperatures this month," said Weather.com meteorologist Chris Dolce Thursday. That means neither El Niño, nor its counterpart La Niña, are ongoing.

Contributing: Reuters

This article originally appeared on USA TODAY: Where is La Niña? Why the climate troublemaker is making a late arrival for 2024