What is hail? There are four different types of precipitations that fall from the sky, and hail is one among them. When frozen rain falls from the clouds in the form of pellets and pebbles, we call it as hail. It is a common phenomenon on higher elevations during severe thunderstorms. If the hails measure more than 0.75 inches in diameter, then the situation is usually classified as a severe weather condition.
Hailstorms are formed within a unstable air mass. In such unstable air mass very fast current of air move upwards (updrafts) and downwards (downdrafts). Inside those upward movements water vapour and rain are pushed into the cumulonimbus cloud. At a specific height, the air temperature drops below the freezing point to form tiny ice particles. When these tiny ice particles move through rain and vapour, it will have further layers. The several movements of these particles through updrafts and downdrafts within the thunderstorm makes the hail a considerably big ice piece. Once it reaches to a weight that the updrafts cannot take the hail away from the force of gravity, it will be caught by the downdraft and brought to earth in the form of hailstorm. If you understood what is hail through this article, you may be interested to learn about the river of hail in Iraq.