What does the weather forecast mean by "seven ups and eight downs"? Why is this happening?

The so-called eight phases of enamel means that the northern part of China has entered the rainy season. Because the obituaries affecting the distribution of summer rainfall gradually moved northward. This period is the period with the best thermal conditions and the largest energy in the ocean. Although the movement of obituaries is related to the thermal state, the hottest energy in the northern hemisphere is most concentrated in summer, and the obituaries will move northward. Therefore, the rainfall system usually distributed in the north and west of obituaries will move northward, making northeast China enter the summer rainstorm period.

It can also be said that on July 8, the typhoon period in China reached its peak, and more and more typhoons went northward. The overall rainy season and typhoon period in China come at the same time. It puts pressure on the weather prevention in China. So July, August and August are the rainfall patterns in China for many years. We can expect extreme weather during this period, so the national flood control department should be prepared. We should also pay attention to meteorological information in time, grasp the dynamics, and be prepared to prevent disasters caused by rainfall. The rainy season is from late July to early August every year. Due to the influence of sunlight moving from the equator to the north, more warm air masses are gathered in the atmosphere, which is the outbreak period of coastal double-sided typhoon, and various factors lead to continuous heavy rain in mainland China, especially in coastal cities.

It has something to do with the location of the obituary. From February to May, South China was controlled by Nanling, with heavy precipitation south of Nanling and smog around Jiangnan and Jianghan. From May to July, obituaries brought heavy rainfall to Lingnan, Jiangnan and Jianghan, and from July to August, obituaries brought heavy rain to Jiangnan, Jiangnan and North China. These three places are formed by the intersection of cold air in the north and warm and humid air in the south. The geographical cold front is raining. The official explanation of this order is: "The capital Beijing comes first, and other provincial capitals are divided according to the geographical location and climate characteristics, the work of the State Bureau of Surveying and Mapping and the China Meteorological Bureau, and the principle of north to south and west to east, which is decided and approved by the State Council.

There are also unpalatable cities, one is five cities with separate plans, the other is four tourist cities, and the other is two revolutionary holy places. The next few cities all have the flavor of declaring sovereignty. When writing The Legend of Kunming, I interviewed Yunnan Meteorological Observatory, Railway Station, Kunming Meteorological Observatory, Railway Station, and meteorological stations all over Yunnan, and referred to the meteorological data of grass-roots units in the whole country and even the whole world, including the National Meteorological Administration, provincial meteorological bureaus, local meteorological bureaus, and counties, and obtained the most original local meteorological data. In other words, the sequence of CCTV weather forecast is based on this.