system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do baseball sized hails stay supported in culumonimbus clouds long enough to form that mass before they fall in hailstorms?
gpt
The hailstones travel up and down inside the thunderhead, gaining mass and size on each leg, cycling up & down several times.  They are trapped in the updrafts, and at some point get so heavy that they fall to the ground.  The updrafts in those storms are very powerful, and provide a lot of lift.