60% chance for La Niña in late 2024. Mild or cold winter?


La Niña in late 2024: A cutaway shot of the ocean surface, showing both the surface and some of the depths.
La Niña in late 2024? Spanish for “the girl,” La Niña is a periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. Typically, La Niña events occur every 3 to 5 years, but they can also happen over successive years, affecting weather around the globe. Image via NOAA’s World Ocean Database.

Will we have La Niña in late 2024?

NOAA’s Climate Prediction Center has issued a La Niña Watch, meaning that conditions are favorable for La Niña in late 2024 or early 2025. La Niña occurs when cold water from the depths of the equatorial Pacific rises up to the ocean surface, causing a change in weather patterns around the world.

NOAA is predicting a 60% chance for a weak La Niña event, developing in the Northern Hemisphere autumn months. And, if it happens, the La Niña is expected to persist through January-March, 2025. This event could lead to a dry and mild winter in the U.S. South and parts of Mexico, and a colder winter in the U.S. Northeast. And the northern tier of the U.S. and southern Canada could be wetter than average.

La Niña and El Niño are phases within the El Niño-Southern Oscillation, a naturally occurring global climate pattern. This pattern involves changes in wind and ocean temperatures in the Pacific and can cause extreme weather across the planet. La Nina is the cool phase of the pattern. And El Niño is the warm phase, occurring along with a weakening of trade winds that typically blow across the Pacific toward Asia. These winds weaken, allowing warm ocean waters to pile up along the western edge of South America.

A recent triple-dip La Niña

AP reported:

These cold ocean temperatures and changes in the atmosphere affect the position of the jet stream — a narrow band of fast moving air flowing from west to east around the planet—by bumping it northward. The jet stream sits over the ocean and can tap into its moisture, influence the path storms take and boost precipitation.

Just recently Earth experienced a ‘triple-dip’ La Niña event from 2020 to 2023. ‘We had three back-to-back winters where we had La Niña conditions, which was unusual because the only other case of that happening was back in 1973 to 1976,’ said Michelle L’Heurex, a climate scientist at NOAA.

L’Heurex said that La Niña’s tend to last longer and be more recurrent than El Niño events.

Chart showing cooler ocean temperatures than usual in 2024.
La Niña in late 2024? Ocean surface waters have been cooler than usual in recent months. Image via NOAA.

Bottom line: The National Oceanic and Atmospheric Administration (NOAA) has issued a La Niña for the northern autumn of 2024. If it happens, conditions will likely persist to early 2025.

Via AP

The post 60% chance for La Niña in late 2024. Mild or cold winter? first appeared on EarthSky.



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La Niña in late 2024: A cutaway shot of the ocean surface, showing both the surface and some of the depths.
La Niña in late 2024? Spanish for “the girl,” La Niña is a periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. Typically, La Niña events occur every 3 to 5 years, but they can also happen over successive years, affecting weather around the globe. Image via NOAA’s World Ocean Database.

Will we have La Niña in late 2024?

NOAA’s Climate Prediction Center has issued a La Niña Watch, meaning that conditions are favorable for La Niña in late 2024 or early 2025. La Niña occurs when cold water from the depths of the equatorial Pacific rises up to the ocean surface, causing a change in weather patterns around the world.

NOAA is predicting a 60% chance for a weak La Niña event, developing in the Northern Hemisphere autumn months. And, if it happens, the La Niña is expected to persist through January-March, 2025. This event could lead to a dry and mild winter in the U.S. South and parts of Mexico, and a colder winter in the U.S. Northeast. And the northern tier of the U.S. and southern Canada could be wetter than average.

La Niña and El Niño are phases within the El Niño-Southern Oscillation, a naturally occurring global climate pattern. This pattern involves changes in wind and ocean temperatures in the Pacific and can cause extreme weather across the planet. La Nina is the cool phase of the pattern. And El Niño is the warm phase, occurring along with a weakening of trade winds that typically blow across the Pacific toward Asia. These winds weaken, allowing warm ocean waters to pile up along the western edge of South America.

A recent triple-dip La Niña

AP reported:

These cold ocean temperatures and changes in the atmosphere affect the position of the jet stream — a narrow band of fast moving air flowing from west to east around the planet—by bumping it northward. The jet stream sits over the ocean and can tap into its moisture, influence the path storms take and boost precipitation.

Just recently Earth experienced a ‘triple-dip’ La Niña event from 2020 to 2023. ‘We had three back-to-back winters where we had La Niña conditions, which was unusual because the only other case of that happening was back in 1973 to 1976,’ said Michelle L’Heurex, a climate scientist at NOAA.

L’Heurex said that La Niña’s tend to last longer and be more recurrent than El Niño events.

Chart showing cooler ocean temperatures than usual in 2024.
La Niña in late 2024? Ocean surface waters have been cooler than usual in recent months. Image via NOAA.

Bottom line: The National Oceanic and Atmospheric Administration (NOAA) has issued a La Niña for the northern autumn of 2024. If it happens, conditions will likely persist to early 2025.

Via AP

The post 60% chance for La Niña in late 2024. Mild or cold winter? first appeared on EarthSky.



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