During the course of an average year, hail causes more than $1.6 billion worth of damage to residential roofs in the United States. Hail storms are most frequent in the Southern and Central Plains states where warm, moist air off of the Gulf of Mexico and cold, dry air from Canada collide. The combination of the two different air masses spawn violent thunderstorms.
Hail is created when frozen water drops are lifted in turbulent wind regimes during thunderstorms. As the frozen water is driven to the earth at speeds up to 90 mph, it has the ability to increase in size and form a hail stone. Hail stones can vary in size from pea sized (1/4-inch diameter, minimal roof damage), quarter sized (1-inch diameter, moderate roof damage), golf-ball sized (1.5-inch diameter, severe roof damage) or even larger, causing catastrophic damage.