Why is it so cold in spring?

Why does the cold air linger? It's cold.

The "beginning of spring" and "rain" in the 24 solar terms have all passed. Why is the cold air still lingering? It's too cold. First, the south branch trough, which has long been located near the southern part of the Qinghai-Tibet Plateau, is unstable and has recently moved eastward. This means that the cold steam flow from the northwest meets the warm water vapor from the Indian Ocean in the south of China, resulting in rainy weather.

Secondly, in recent months, influenced by the double-peak La Nina phenomenon, La Nina, which just disappeared, reappeared in August of 20021year. The water temperature in the central Pacific is 0.54 degrees Celsius lower than the average water temperature, 0.56 degrees Celsius lower than the average water temperature in September 20021year, and 0.95 degrees Celsius lower than the average water temperature in June 2022.

In the northern hemisphere, cold air comes from the cold North Pole. There is a strong extremely cold circulation over the North Pole, which rotates counterclockwise. It is called "Arctic Polar Vortex". If the polar vortex is unstable, the circulation will throw cold air to low latitudes. This is the source of cold air.

The biggest function of La Nina phenomenon is to enhance the intensity of cold air, turn it into a cold wave, make it colder in winter and make it linger.

In fact, there is heavy rain and snow all over the world.

There will be a wave of heavy rain and snow in Europe, and there may be heavy rain and blizzard in some areas. This is because the westerly belt trough system moves eastward and the westerly belt vortex system moves eastward from the North Atlantic to Western Europe.