Unlike ice pellets, hailstones are layered and can be irregular and clumped together. Hail is composed of transparent ice or alternating layers of transparent and translucent ice at least {{convert|1|mm|in}} thick, which are deposited upon the hailstone as it travels through the cloud, suspended aloft by air with strong upward motion until its weight overcomes the [[vertical draft|updraft]] and falls to the ground. Although the diameter of hail is varied, in the United States, the average observation of damaging hail is between 2.5 cm (1 in) and [[golf ball]]-sized (1.75 in).<ref>{{cite web|url=http://www.spc.noaa.gov/publications/jewell/hailslsc.pdf|title=P9.5 Evaluation of an Alberta Hail Growth Model Using Severe Hail Proximity Soundings in the United States|author=Ryan Jewell and Julian Brimelow|date=2004-08-17|accessdate=2009-07-15}}</ref> |
Unlike ice pellets, hailstones are layered and can be irregular and clumped together. Hail is composed of transparent ice or alternating layers of transparent and translucent ice at least {{convert|1|mm|in}} thick, which are deposited upon the hailstone as it travels through the cloud, suspended aloft by air with strong upward motion until its weight overcomes the [[vertical draft|updraft]] and falls to the ground. Although the diameter of hail is varied, in the United States, the average observation of damaging hail is between 2.5 cm (1 in) and [[golf ball]]-sized (1.75 in).<ref>{{cite web|url=http://www.spc.noaa.gov/publications/jewell/hailslsc.pdf|title=P9.5 Evaluation of an Alberta Hail Growth Model Using Severe Hail Proximity Soundings in the United States|author=Ryan Jewell and Julian Brimelow|date=2004-08-17|accessdate=2009-07-15}}</ref> |