Although much weaker than the Pacific winds, the Atlantic Niña current can partially counteract the La Niña current by weakening the summer winds that promote upwelling that cools the eastern Pacific.
Why are both of these happening now?
In July and August 2024, meteorologists cooling is noted appears to be the development of an Atlantic Niña along the equator. Winds at the ocean surface are weak throughout most of the summer and sea surface temperatures there quite warm until early JuneSo the appearance of the Atlantic hurricane Niña was a surprise.
At the same time, the waters along the equator in the eastern Pacific Ocean are also cooling, with Expected La Niña conditions in October or November.
The combination of the Pacific and Atlantic Oceans is Niña rare but not impossible. It’s like finding two different pendulums that are weakly coupled to swing in opposite directions that move together over time. The combination of La Niña and Atlantic Niño, or the more common El Niño and Atlantic Niña.
Good news or bad news for hurricane season?
Atlantic Hurricane Niña may initially bring good news to those living in hurricane-prone areas.
Cooler-than-average sea water off the coast of Africa could prevent the formation of the East African wave. These are the clusters of storm activity can form tropical disturbances and eventually tropical storms or hurricanes.
Tropical storm get energy from water evaporation associated with warm sea surface temperatures. So cooling in the tropical Atlantic could weaken this process. That would leave less energy for thunderstorms, reducing the chance of a tropical storm forming.
However, NOAA will take all factors into account when It updates the Atlantic hurricane season outlook.was released in early August and is still predicting an extremely exciting 2024 season. Tropical storm season usually peaks in early to mid-September.
There are two reasons behind the busy forecast: near record warm sea surface temperatures in much of the North Atlantic could intensify hurricanes. And the projected development of La Niña in the Pacific is likely to weaken wind shear—changes in wind speed with altitude can tear storms apart. The much stronger effects of La Niña can overwhelm any effects associated with the Atlantic Niña.
Exacerbating the problem: Global warming
The past two years have witnessed unusually high ocean temperatures in the Atlantic and around many of the world’s oceans. The two Niñas storms may contribute to cooling in certain areas, but it may not last.
In addition to these cycles, the global warming trend due to increased greenhouse gas emissions is increasing core temperatures and may fuel for major hurricanes.
