Did it hail in Shenzhen?

It rains almost every year in Shenzhen, but there is not much hail. If it is a big natural disaster, it will usually be reported. What do you say: Hail is ice or hockey that falls to the ground from strong convective cumulonimbus clouds. It is a solid precipitate with transparent, opaque and hard cores on the outer layer, generally larger than 5 mm in diameter, as small as peas, as big as eggs, and even as big as a small bowl. Hail is often accompanied by thunderstorms and strong winds. Before the hail, the weather was sultry and the air pressure dropped, and the highest temperature could reach above 30℃. Hail clouds are black, the bottom is red, and thunder rumbles. Hail often appears in long and narrow areas, with a small range. As some people say, "hail hits the line" often appears in spring and summer, which has a negative impact on crops.

Hail mostly comes from strong convective cumulonimbus clouds. The diameter of hail is generally in the range of 5-50 mm, which can reach several centimeters to several tens of centimeters. It is conceivable that even if a small hail can exist in the cloud, it needs a strong updraft. According to statistics, the rising speed of hail must be greater than 20m/s, and it needs to be greater than 20m/s to produce hail with a diameter of 10cm. Therefore, it is possible to hail when the cloud top near the tropopause develops. When the airflow rises above 0℃, the hail is not produced immediately, and an opaque core can be seen by dissecting the hail. The outside is alternately surrounded by transparent and opaque ice. So hail is white from a distance, not as transparent as ice. Why is hail such a structure? This is determined by the process of hail formation. Because the temperature below 0℃ in cumulonimbus clouds is water droplets, and supercooled water droplets, ice crystals and snowflakes are above them. When supercooled water droplets rise with the updraft, they freeze with ice crystals or snowflakes to form the core of hail. Because the freezing time is short and the freezing speed is fast, the hail nuclei formed are mixed with air, and the organization is loose, forming an opaque white ice layer. The faster it freezes, the whiter and more opaque it becomes. After the hail core is formed, it will drop because of its heavy weight or weakened updraft. When the temperature drops below 0℃, the ice on the surface of the hail core will melt into water, and at the same time it will collide with some raindrops, and some water will stick outside. When the hail core covered by water meets a strong updraft, it is brought above 0℃ again. At this time, the water outside the hail core freezes into ice again, and then gradually freezes, so it becomes a transparent ice layer. When hail meets supercooled water droplets again, it condenses on them and collides with ice crystals and snowflakes to form an opaque ice layer. The volume of hail increases and decreases, and if it is repeated many times, it may form a big hail.