According to the American Climate Forecasting Center, in the period from December 2021 to February 2022, i.e. this winter, the chances of the appearance of the La Nina phenomenon reach 90 percent.
Scientists from the US Climate Prediction Center, which is an agency of the National Weather Service, reported that temperatures in the central and eastern parts of the Pacific have been lower than usual for weeks. In addition, there are favorable wind gusts – for the last month the wind near the equator has been low. The so-called passats, which usually blow from east to west, were stronger than usual. The same was the case with gusts in the higher parts of the atmosphere.
Looking at the available indicators, according to specialists, everything indicates that similar conditions will continue, and maybe strengthen, also in the coming months. Currently, the odds of La Nina being affected by the weather from December 2021 to February 2022 are estimated to be 87 percent.
Preliminary forecasts indicate that the return to normal ocean conditions is not expected until around March and May.
What is La Nina?
The La Nina phenomenon occurs when the surface temperature of the Pacific Ocean near the equator, especially off the coast of South America, is below average. This is due to the increased activity of trade winds – permanent winds – in this part of the world. They bring cool deep water to the ocean’s surface.
The relationship between the ocean and the atmosphere influences the position of the jet stream, thus affecting the world’s weather. La Nina increases the flow of cold air from Canada to the United States, which cools the winters in the region. It also contributes to the occurrence of stronger monsoon rainfall in India.
La Nina can also affect the weather in Europe, but due to its great distance from the Pacific Ocean, these relationships are the most difficult to predict. This is the opposite of El Niño, where the Pacific is warmer and the trade winds fade away.
More accurate forecasts for winter weather in the United States should be expected next week.
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