First of all…WHAT IS HAIL???!!!

Hail is a rainfall of ice pellets with diameters about five millimeters or more. Below that size, the pellets are defined as snow. Hail pellets can grow to be much bigger than the minimum: they can exceed ten centimeters in diameter - the size of a grapefruit. It’s created in the center of thunderstorms like so: water vapor in warm, rapidly rising air masses condenses to become water at higher, cooler altitudes. This normally produces heavy showers. However, when the vapor or water is pushed up enough to meet cold enough air, the object can become ice. Then, layers and layers of ice then form around minute specks like dust picked up from the ground. The center increase in size as more water freezes to their surfaces. Then when the pellets are too heavy for the rising air currents, they fall as hail. They may pick up more water on the way down, becoming larger, heavier and more imperiling.

http://cgdi.gc.ca/ccatlas/hazardnet/f_hail/hailintro.htm