I don't know if you've heard the words "entering and leaving plum". Many people don't know what these two words mean. But if Xiaobian mentions Meiyu season, do you have a general understanding? Then what is the time of entering and leaving plum in 2019? Let's have a look
Meiyu refers to the continuous rainy weather in the middle and lower reaches of the Yangtze River in China from the middle of June to the first and middle of July every year. At this time, the utensils are easy to mould, so they are also called 'mould rain'. They are also called 'Meiyu' or 'huangmeiyu' because they are ripe yellow in the south of the Yangtze River. The duration of rain belt stay is called 'plum rain season', the beginning day of plum rain season is called 'entering plum', and the end day is called 'plum blossom'.
Weather characteristics in Meiyu Period
Continuous rain, high temperature and humidity. After less rain, the weather moved to the North China area.
Normal and abnormal Meiyu
On average, the normal Meiyu in the middle and lower reaches of the Yangtze River began in mid June and ended in mid July, lasting for more than 20 days. However, for each specific year, there are great differences in the beginning and end of Meiyu and the strength of Meiyu. As a result, the plum rain in some years is obvious, while it is not obvious in some years, even resulting in empty plum phenomenon.
Usually during the summer solstice, or from late June to early July, it is generally the period with the most abundant rainfall in the middle and lower reaches of the Yangtze River, which happens to coincide with the ripening of plums, which is called plum rain locally. The rain belt will swing from the Yangtze River Huaihe River to the south of the Yangtze River. Generally, the middle reaches of the Yangtze River reach the plum blossom on June 15, and the lower reaches on June 19. In fact, Meiyu corresponds to a major adjustment of the atmospheric circulation in early summer. The northward elevation of the subtropical high will push the main battlefield of cold and warm air from South China to the south of the Yangtze River to the middle and lower reaches of the Yangtze River. Once it enters the plum blossom, the pre flood season in South China is often over, and it turns into hot and muggy weather.
The Meiyu rainy season begins sooner or later and fluctuates every year. The key is to see the situation of atmospheric circulation. One is the location of the trough ridge of the westerly belt, the other is the location of the subtropical high. The location of the subtropical high should be as stable as possible. The warm and humid air should be continuously transported to the middle and lower reaches of the Yangtze River, and meet with the cold air from the south of the north. In order to make the location of rain belt relatively stable, from the middle and lower reaches of the Yangtze River to the southern part of Japan, the climate characteristics of rainy weather are formed from the middle and lower reaches of the Yangtze River to the southern part of Japan from the middle of June to the first and middle of July.
Before and after June 19, 2018, many places in the middle and lower reaches of the Yangtze River announced the arrival of plum blossom, which was basically normal and slightly late. However, during the Meiyu period in 2018, the subtropical high position was not very stable, and it first moved to the north and then fell down. Therefore, the rain belt did not completely stabilize and fluctuated from north to south. On June 25-26, the rain belt ran to the east of Northwest China to the Huanghuai River (that is, the record breaking flood in some areas of Shandong Province during the heavy rainstorm on June 25-26), and the rain belt fell to the south from the end of June to the beginning of July. The Meiyu in 2018 was not very typical. However, the precipitation in Meiyu period is not required to rain every day. There can be a pause or even a period of interruption, and then a period of rainy period, that is, multi period Meiyu period.