What is hail? Where is the hail most likely to appear?

Hail is some ice particles as small as mung beans and soybeans and as big as chestnuts and eggs.

The water on the local surface is evaporated by sunlight and then rises into the air. A lot of water vapor condenses into clouds. The relative humidity at this time is 100%. When it meets cold air, it will liquefy, and the dust in the air will condense, forming raindrops (tropical rain) or ice crystals (mid-latitude rain), which are getting bigger and bigger. When the temperature drops to a certain extent, the water vapor in the air will be supersaturated, so it will rain. if

Every year, all parts of China are hit by different degrees of hail. Especially in the mountainous and hilly areas in the north, the eastern part of the Qinghai-Tibet Plateau and the Yunnan-Guizhou area, the terrain is complex, the weather is changeable and there are many hail, which is very harmful to agriculture. Heavy hail destroyed crops and houses, injured people and killed livestock. Extraordinary hail is bigger than grapefruit, which will kill people, destroy a large area of farmland and trees, and destroy buildings and vehicles. It has powerful lethality. Hail disaster is one of the serious natural disasters in China.

Hail occurs in a wide area, from subtropical to temperate climate zones, but most of them occur in temperate regions. It mainly occurs in the mid-latitude continent, usually more in the north than in the south, more in the mountains than in the plains, and more in the inland than in the coastal areas. This distribution is related to large-scale cold air activities and topography. China suffered severe hail disasters in southern Gansu, Longdong, the yinshan mountains, Taihang Mountain, western Sichuan and Yunnan Province.

It is greatly influenced by the terrain. The more complex the terrain, the greater the possibility of hail.

The area with the most hail in China is the Qinghai-Tibet Plateau, such as Heihe (Naqu) in the northeast of Xizang Autonomous Region, with an average annual hail of 35.9 days (53 days in the most years, at least 23 days); Followed by Bango 3 1.4 days, Shenzha 28.0 days, Amdo 27.9 days, Suoxian 27.6 days, all appeared in the Qinghai-Tibet Plateau.