Hail weather appeared in many places in Henan. How is the hail formed?

Hail weather occurs in many places in Henan, which is undoubtedly abnormal weather. Recently, scattered showers and thunderstorms have occurred in some areas of Henan, accompanied by strong convective weather such as short-term heavy precipitation, short-term strong wind and hail. ? People don't understand how hail is formed. There are several processes for the formation of hail.

Hail is born in the development of powerful cumulonimbus clouds, which are called hail clouds. Hail clouds are composed of water droplets, ice crystals and snowflakes, which are usually divided into three layers: the bottom layer is composed of water droplets with a temperature above 0℃; The second layer consists of water droplets with a temperature higher than 0℃. The temperature in the middle layer is -20? 0℃, composed of supercooled water droplets, ice crystals and snowflakes. The temperature of the top layer is lower than -20℃, which is basically composed of ice crystals and snowflakes.

In the hail cloud, the updraft will change, sometimes strong and sometimes weak. When the updraft is strong, the water droplets in the lower part of the cloud are brought to the upper part of the cloud, and the water droplets quickly cool and solidify into small ice crystals. During the falling process, small ice crystals collide with supercooled water droplets and freeze on them, forming opaque ice cores and hail embryos. Due to the rapid change of airflow in hail clouds, hail embryos roll in the air again and again, and more supercooled water droplets, such as snowballs, are attached, and the rolling is getting bigger and bigger. Once involved in a big hail, when it rises in the clouds, it will fall from the sky and become what ordinary people say? Hail? . The strong updraft not only delivers enough water vapor to the hail cloud, but also supports the continuous growth of hail particles in the cloud, making them grow to a considerable size before falling.

The formation conditions of hail mainly include the following points. First of all, there must be a fairly thick unstable layer in the atmosphere. At the same time, the cumulonimbus cloud must be developed to a height that can freeze a single large water drop, and there must be strong wind shear. Finally, there should be an inclined, strong and uneven updraft in the cloud, usually 10-20 M/s or higher.