What does Meiyu mean?

Plum rain refers to the rain in Huangmei season.

There will be continuous rainy weather in the solar calendar from early June to mid-July every year. At this time, due to the long-term rainy, sunny and humid weather, household utensils are prone to mildew, which is also called "mildew rain" by the people.

Meiyu weather mainly occurs in Jiangnan, the middle and lower reaches of the Yangtze River, Jianghuai, South Korea, Japan and other places. Meiyu season is called "Meiyu" because it coincides with the maturity of plums in Jiangnan.

Meiyu is a unique product of East Asian summer monsoon advancing northward in stages, and it is a unique weather and climate phenomenon in East Asia. Meiyu is also the most significant season of monsoon precipitation in China. The climate in Meiyu season is characterized by concentrated precipitation, heavy rainfall, few sunshine hours, cloudy weather and low wind.

Formation conditions of plum rain:

1. There is blocking high pressure or stable high pressure ridge in the middle troposphere in high latitudes of Asia, and the atmospheric circulation is relatively stable with little change.

2. The westerly circulation in the mid-latitude area is gentle, and frequent short-wave activities provide cold air conditions for the Jianghuai area.

3. The western Pacific subtropical high has an obvious process of extending westward and jumping northward. The ridge line of the 500 hPa subtropical high is stable between 20 and 25 degrees north latitude, and the warm and humid air flow is transported from the edge of the subtropical high to the Jianghuai Basin.

Under this circulation condition, Meiyu front lingers in the Jianghuai basin, often accompanied by southwest vortex and shear line, and the mesoscale system on Meiyu front is active. It not only maintains the continuous precipitation during the Meiyu period, but also provides abundant water for the rainstorm.