What is the cause of extreme cold weather?

Extremely cold weather is due to the development of La Nina time similar to that of East Taiping, which leads to the low temperature in most of winter in China. At the same time, the sea surface temperature in the North Pacific continues to be warmer, and the Siberian high continues to increase, resulting in a great difference in heat between the sea surface and the land, while the winter gale in East Asia brings cold air.

Extreme cold weather, especially in the middle and late June of 65438+ 10, on the eve of the Spring Festival, due to the obvious change of atmospheric circulation, polar cold air will spread southward, and northern cold air will affect China southward. When they are stable, there will be more rainy days in the south and more rain, snow and freezing weather in winter.

Arctic oscillation refers to the pressure change in the Arctic. The control of high altitude and low pressure will make the cold air in the Arctic shrink, and the corresponding temperature in mid-latitude will be higher. When the high altitude in the Arctic is controlled by high pressure, the cold air in the polar region will also erupt southward, and there will also be strong cold wave weather.

Extreme cold weather, that is, in the cold degree scale table formulated by meteorological specialty, there is a low-to-high grade between MINUS 40 degrees and 9.9 degrees, which is called extreme cold weather, and extreme cold weather usually represents MINUS 40 degrees.