How long does the rainy day usually last?

How is the plum rain formed and why does it last for a month?

First, what is the "Meiyu" season

"Meiyu season" refers to the climate phenomenon that the warm and humid air flow in the Pacific Ocean brought by the southeast monsoon passes through the middle and lower reaches of the Yangtze River in China, Taiwan Province Province in China, south-central Japan and South Korea every June and July, and causes continuous rain. When the summer monsoon warm air flows northward and meets the cold air from north to south, because the warm air is light and the cold air is heavy, the lighter warm humidity will be lifted above the cold air. It forms the frontal rain every summer, and the winter and summer monsoons in the middle reaches of the Yangtze River are evenly matched. The rain lasted for a month. Because the plums in Jiangnan are ripe, they are called "Meiyu". .

What's the reason? Every year from late April to early May, cold air in the north and warm air in the south meet in South China. When encountering cold air masses, there will be a lot of convective activities. Because of the equal influence of cold and warm air during this period, the front stays in Jianghuai area. It is easy to form floods.

2. The movement characteristics of Meiyu

In May, the rain belt landed from the southern coast; . In mid-June, the rain belt moved northward to the middle and lower reaches of the Yangtze River, swinging between Jianghuai for about a month. From the middle and late July to August, the rain belt moved northward to North China and Northeast China, and there was a drought in the middle and lower reaches of the Yangtze River. In September, the rain belt moved southward. The rainy season ended in June 5438+10. ? On the contrary, there is no rainy season in the north. Due to the influence of altitude, the precipitation in the north is insufficient all the year round, which leads to serious drought in the northwest, which is also the reason why most people think that the north is "short of water".

Three: Why did it last for more than a month?

The rainy weather in the south is due to the influence of warm and humid airflow and the experience of cold air in the north. When hot and cold meet, it will form a continuous rainy weather. In fact, this is also a natural climate phenomenon, just like the snowy northeast. Warm and humid air from the Pacific Ocean, transported by the southeast wind, meets the cold air in the north and gathers in the middle and lower reaches of the Yangtze River to form continuous rainfall. High humidity and high temperature in rainy season make clothes moldy. Therefore, some people call' plum rain'' mildew rain'. After the meiyu, the south officially entered the high temperature and high fever period in summer!