Hail is produced when strong updrafts within thunderstorms carry raindrops high into the atmosphere where they freeze into ice. These frozen particles then fall back down to the ground, getting carried back up again by the updrafts and growing in size as they collide with other frozen particles and collect additional moisture.
The updrafts within thunderstorms are caused by the heating of the earth's surface by the sun, which causes the air near the ground to rise. This rising air then encounters cooler air in the upper atmosphere, causing it to cool and condense into clouds. As the clouds continue to rise, the air becomes even cooler, causing any moisture in the clouds to freeze into ice.
The hailstones can vary in size depending on how many times they are carried up and down by the updrafts and how much moisture they are able to collect before falling to the ground. In some cases, hailstones can grow to be several inches in diameter, causing damage to buildings, vehicles, and crops.
