2. Rain exists in the form of water droplets, and liquid forms convection from clouds.
3. Hail is a spherical or irregular solid rainfall.
Rain is changed by clouds. The volume of raindrops is 6.5438+0 million times that of cloud drops. In other words, it takes 6.5438+0 million cloud drops to form a raindrop. In humid air, cloud droplets condense due to cooling. In warm clouds with cloud body temperature higher than 0℃, there are cloud drops of different sizes in the clouds, and the big cloud drops fall fast and rise slowly.
Xiaoyun drops down slowly, but rises quickly. Therefore, due to the difference in relative velocity between large and small cloud droplets, large cloud droplets may collide with small cloud droplets, and as a result, small cloud droplets merge into large cloud droplets. In this way, the number of large cloud droplets is increasing, and because of the uneven distribution of updraft, large cloud droplets can move up and down many times in the cloud. Coupled with the turbulence in the cloud, the probability of large cloud droplets increasing increases, so the large cloud droplets become bigger and bigger until they rise.
As a large number of graupel particles fall into the sea of clouds, the water mist in the clouds gathers on the graupel particles and freezes into larger graupel particles. When it gathers to a diameter of about 1 mm, the original graupel particles melt into water and fall to the ground in the form of raindrops. In winter, the original graupel particles did not dissolve, forming snowflakes or large graupel particles and falling to the ground.
On a clear day, when high-altitude graupel particles pass through cloudless clouds in Wan Li, they melt in mid-air due to rising temperature and become mist, or fall to the ground to become dew and frost, or be evaporated again by sunlight and wind the next day. These high-altitude graupel particles are too small to dissolve easily and it is difficult to "catch" on the spot.
Hail falls from the clouds like rain and snow. But the clouds that hail are very strong cumulonimbus clouds, and only very strong cumulonimbus clouds can hail.