Hail is a form of precipitation which consists of balls or irregular lumps of ice. It forms on condensation nuclei such as dust, insects, or ice crystals, when super-cooled water freezes on contact.
Once a hailstone is too heavy to be supported by the storm's updraft, it falls out of the cloud. These hailstones can range from pea-sized to softball-sized clusters of ice, with large stones falling at speeds faster than 100 mph.
Before the hail storm:
If a severe thunderstorm has been predicted to produce hail, you should: