How Does Hail Form? Hail is large, layered ice particles, often spherical, which are produced by thunderstorms having strong, powerful winds. Hailstorms form within an unusually unstable air mass, that is, an air mass in which the temperature falloff with height is much more significant than usual.
During the thunderstorm, powerful winds take raindrops within them. It is colder on top of the windstorm, and this causes the rain to freeze. The wind blows the icy drops up and down, up and down, through the storm; the drops collect more ice creating ice chunks. Finally, they get too heavy, and they fall to the ground. That is hail!
What causes a hailstorm to occur?
Several conditions are required in the atmosphere in order for hailstorms to occur. Highly developed Cumulonimbus clouds need to be present. Cumulonimbus Clouds are a dense, towering vertical cloud, forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus Clouds can form alone, in clusters, or along cold front squall lines (Wikipedia). These are the massive anvil or mushroom-shaped clouds that are seen during thunderstorms which can reach heights up to 65,000 feet.
The air currents in these clouds are commonly known as updrafts. The updrafts contain ice particles as discussed above. For a hail storm to occur, the last remaining condition is that the clouds will need to contain high concentrations of water.
Fun Hail Fact:
Pieces of hail are called hailstones, and if you cut a hailstone in half, you will see rings. You can count the rings to find out how many times the hailstorm went back up into the freezing cold top of the storm before it finally fell to the ground.
Another article post you might be interested in is “Graupel aka: Soft Hail” check it out. *