Seasons and Genesis of Quasi-static Front in Tianshan Mountains

The quasi-static front of Tianshan Mountain mostly appears in winter and spring. The reason is that the cold air going south in winter is blocked by the topography of Yunnan-Guizhou Plateau. Because the topography of Yunnan-Guizhou Plateau is high in the southwest and low in the northeast, the speed of cold air slows down in the process of climbing southwest, forming a quasi-static front.

After the cold air mass from Siberia and the North Atlantic enters the Junggar Basin, it is blocked by the Tianshan Mountains, which makes the cold front stagnate and often forms a Tianshan quasi-static front with the nature of topographic front, resulting in cloudy, foggy or light snow weather. The excessive precipitation in winter and spring in the northern slope of Tianshan Mountain and most parts of northern Xinjiang is related to the quasi-static frontal activity in Tianshan Mountain. Tianshan quasi-static front is one of the main quasi-static fronts affecting China.

South China quasi-stationary weather front, also known as Nanling stationary front, refers to a quasi-stationary front located in South China and distributed in the east-west direction. When it is located in the northern part of the South China Sea, it is also called the static front of the South China Sea. Its formation is mostly caused by the weakening of cold air after going south and the blocking of Nanling mountains. It often appears with the air shear line. It is easterly to the north and southerly to the south, with obvious precipitation, which is an important weather system affecting South China.

Jianghuai quasi-static front, the formation of plum rain-Jianghuai quasi-static front, from the Jianghuai valley in China to the southern part of Japan and South Korea, has a continuous rainy period from June to July in early summer every year, with more precipitation and more precipitation times, which coincides with the yellow ripening period of plums in the south of the Yangtze River, so it is called "plum rain".

Kunming quasi-static front, also known as Yunnan-Guizhou quasi-static front, is an atmospheric phenomenon in Yunnan-Guizhou Plateau, which is mainly formed by the denatured polar continental air mass and southwest airflow blocked by the topography of Yunnan-Guizhou Plateau. Clouds are low and thin, and it is easy to form continuous rainy weather. This weather phenomenon mostly occurs in winter, and the number of winter days accounts for about half of the whole year.

Tianshan quasi-static front, after the weak cold air mass from Siberia and the North Atlantic enters the Junggar Basin, it is blocked by Tianshan Mountain, which makes the cold front stagnate, and often forms Tianshan quasi-static front with the nature of topographic front, resulting in cloudy, foggy or light snow weather. The excessive precipitation in winter and spring in the northern slope of Tianshan Mountain and most parts of northern Xinjiang is related to the quasi-static frontal activity in Tianshan Mountain. Tianshan quasi-static front is one of the main quasi-static fronts affecting China.

The formation of quasi-static front is not necessarily equal to the formation of cold and warm air masses, but it can also be formed in some areas due to topography. In China, there are two quasi-static fronts formed by topographic factors, namely "Tianshan quasi-static front" and "Kunming quasi-static front". Due to the cold air from the Arctic Ocean and the prevailing westerly wind from the Atlantic Ocean, the quasi-static front of Tianshan Mountain appears on the northern slope of Tianshan Mountain in northwest Xinjiang, China.

After entering the Junggar basin in China, it was blocked by Tianshan Mountains, which made the cold air climb along the northern slope of Tianshan Mountains, and the speed gradually slowed down, and it formed continuous rainy weather on the northern slope of Tianshan Mountains, forming the effect of quasi-static front stop.