What causes hailstorms?

Hailstorms occur when strong updrafts in thunderclouds carry raindrops into extremely cold regions of the atmosphere, where they freeze. As the frozen droplets fall and are lifted again by the updraft, additional layers of ice form around them. This process continues until the hailstones become too heavy for the updraft to support, and they fall to the ground. Hailstones can vary in size, from small pellets to large chunks capable of causing significant damage to crops, vehicles, and buildings.