About the rainy weather in the south in recent days. . . . .

The main reasons are the recent abnormal atmospheric circulation and frequent precipitation weather system.

1. When winter goes and spring comes, the cold air forces gradually weaken, the subtropical high begins to move northward, and the warm and humid air on the ocean becomes active. When spring comes, cold and warm air often meet in Jiangnan, thus forming rainy weather.

2. In the spring in the south of the Yangtze River, there are many depressions. The clouds in the low pressure move fast, the wind is strong and the rain is urgent. Whenever the low pressure passes, there will be rainy weather.

When spring comes, there is a lot of water vapor in the atmosphere. When it gets cold at night, these water vapor can easily condense into fog or Mao Mao rain.