Hailstones can cause major damage to buildings and vehicles depending on the size they reach; in the central plains, there are commonly hailstones the size of softballs or even bigger. The largest hailstone ever documented was found in Vivian, South Dakota on July 23, 2010, and it was over 18.5 inches in circumference.
The former record holder was recovered in Aurora, Illinois in 2003. It measured an approximate 18.25 inches (because about 40 percent of it broke off when it hit a gutter), and no weight could be taken because it wasn’t preserved right away.
According to the University Corporation for Atmospheric Research (UCAR), “In Orient, Iowa, in August 1980, hail drifts were reported to be 2 meters (6 feet) deep. On 11 July 1990, softball-sized hail in Denver, Colorado, caused $625 million in property damage, mostly to automobiles and roofs. Forty-seven people at an amusement park were seriously injured when a power failure trapped them on a Ferris wheel and they were battered by softball-sized hail."
How is hail formed in such massive proportions; in these cases, as large as a soccer ball, and how can such expensive damage be avoided?