Why is the weather so abnormal recently?

The direct cause of the recent rain and snow weather is the abnormal atmospheric circulation. According to the analysis, judging from the evolution of atmospheric circulation in the short and medium term, cold air has been frequent and warm and humid airflow has been active since winter this year. Especially since June+10 in 5438, the circulation in the middle and high latitudes is mainly meridional, with frequent cold air activities. In addition, the subtropical system is strong, northwest than normal, which is conducive to transporting warm and humid air from the south to the north. On the one hand, the cold air in the north is very active, on the other hand, the warm and humid airflow in the south is continuously transported to the north. The intersection of cold and warm air flow is mainly located in the central and eastern regions of China, which creates favorable circulation conditions for large-scale rain and snow weather.

This year's atmospheric circulation anomaly is related to the "La Nina event" that is taking place in the equatorial Middle East Pacific. Li Weijing, deputy director of the National Climate Center, said that from the perspective of climate change, the current low temperature in the equatorial Middle East Pacific is one of the manifestations of the "La Nina" phenomenon. Statistical analysis shows that the latitude of mid-latitude atmospheric circulation may be strengthened in the winter of the year and the spring of the following year when the strong La Ni? a event occurred, that is, the cold air activity is frequent, which easily leads to low temperature in most parts of northern and eastern China and more precipitation in the north of the Yangtze River.