There are various explanations of how these large stones form and grow. These tiny hailstones are then blown repeatedly up and down by the winds in a cloud. Each time they are blown downward to a region whose temperature is above freezing, the stones collect more moisture, and each time they are blown upward to a region below freezing, the moisture solidifies into ice, and some snow may collect. The stones continue to grow, adding layer after layer, until they are too heavy to be supported by the winds and fall to the ground. In another explanation, it is suggested that hailstones continuously descend, gaining layers by passing through regions of the air that contain different amounts of water.
Hail causes much damage and injury to crops, livestock, property, and airplanes.
See sleet .