Hail is generally produced in strong convective weather and formed in the updraft in cumulonimbus clouds (also known as hail clouds). Ice crystals in the air collide with supercooled water droplets to form small hailstones. The updraft brings small hailstones near the cloud top and throws them forward along the high-altitude wind. When it drops to a certain height, it is "topped" by the updraft and rises again. Repeatedly, the hail will get bigger and bigger.
Characteristics of hail:
1, with strong locality, the impact range of each hail is generally tens of meters to thousands of meters wide and hundreds of meters to more than ten kilometers long.
2. The duration is short. A storm or hail usually lasts only 2 ~ 1 minute, and a few last more than 3 minutes.
It is greatly influenced by the terrain. The more complex the terrain, the greater the possibility of hail.
4. Seasonal, hail mostly occurs from March to 65438+ 10. During this period, warm air is active and cold air is active, which is easy to produce hail. Generally speaking, hail in China mostly occurs in spring, summer and autumn.