Why is there rainy weather in the south?

South China belongs to a typical maritime subtropical monsoon climate. Therefore, from March to April every year, warm and humid air from the South China Sea in China meets cold air from the north of China, forming a quasi-static front in Lingnan, which makes the weather in South China changeable and very humid, with light rain or fog in between, resulting in the phenomenon of returning to the south.

Some cold objects begin to condense after encountering warm and humid airflow, forming water droplets on the surface of the objects.

Second, rainy weather.

Every year from late April to early May, cold air from the north and warm air from the south meet in South China, forming a quasi-static front in South China. By the end of May, the influence of warm air was strengthened, and the quasi-static front moved northward to Jianghuai area, becoming the quasi-static front of Jianghuai (also known as Meiyu front).

Because warm air from the south carries a lot of water vapor, when it meets a cold air mass, it will produce a lot of convection activities. During this period, the strength of cold and warm air is so great that the front stays in the Jianghuai area. At this time, it is the mature period of plums in Jiangnan, so it is called "Meiyu", and this period is called Meiyu season.

When the extended data "Return to the South Sky" appears, the air humidity is close to saturation, and the walls and even the ground will "bubble", and there are wet scenes everywhere, and the air seems to be able to wring out water. Dense fog is the most distinctive appearance of "returning to the south sky" According to statistics, when the phenomenon of returning to the south is serious, the visibility can be reduced to 50 meters.

Meiyu mainly occurs in the middle and lower reaches of the Yangtze River in China and the southernmost part of Taiwan Province Province, Liaodong Peninsula, Korean Peninsula and south-central Japan in the subtropical monsoon climate zone. There is no plum rain in other parts of the world at the same latitude. There is no obvious plum rain in South China.

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Baidu Encyclopedia-Meiyu Season