Why does hail fall from the sky?

Hail falls when storm winds can no longer hold growing pellets of ice inside a thundercloud. A raindrop is lifted into cold air, freezes, gathers more frozen water, and gets heavy. When its weight becomes stronger than the rising wind, it drops to the ground.

The neat clue is inside each hailstone: many have rings, because every trip through the cold, watery parts of the cloud adds another icy coat. Small hail may have taken only a few rides upward, while very large hail needed a much stronger storm.