Wind / Hail Damage During the course of an average year, wind and/or hail causes more than $1.6 billion worth of damage to residential roofs in the United States. These storms usually move through quickly and sometimes you don’t realize your home has been damaged. Sometimes there can be noticeable damage or you may begin to find spots on your ceiling where rain has been leaking in from damage to your roof. The average person can’t look at their roof and see the damage that has occurred. It usually takes a trained eye to see the damage and tell if there is the potential for leaks or perhaps that a new roof is needed to protect your home from further damages. It is always best to have your roof inspected after a storm, before it starts to damage the inside of your home. Windstorms are very strong high winds or violent gusts and may or may not be accompanied by precipitation. Wind speeds during a windstorm typically exceed 34 miles per hour. Wind damage can be attributed to gusts (short bursts of high-speed winds) or longer periods of stronger sustained winds. Windstorms may last for just a few minutes when caused by downbursts from thunderstorms, or they may last for hours when they result from large-scale weather systems. A windstorm that travels in a straight line and is caused by the gust front (the boundary between descending cold air and warm air at the surface) of an approaching thunderstorm is called a derecho. Derechos are capable of causing widespread damage.
Hailstorms include precipitation of balls or pieces of ice with a diameter of about 0.2 inch to more than about 6 inches. Because the formation of hail usually requires cumulonimbus or other convective clouds with strong updrafts, it often accompanies thunderstorms. Large hailstones are often characterized by alternating layers of clear and opaque ice, caused by irregular rates of freezing. In areas where the temperature is not far below 32 °F, freezing occurs slowly, allowing trapped air to escape and producing clear ice. When the hailstone then moves into a much colder area, freezing occurs quickly, trapping air and producing a layer of white ice. Hail is extremely destructive to buildings, if large enough. Hailstones about 6 inches in diameter have fallen during thunderstorms in the Middle West of the United States. Hailstones are most common in the midlatitudes and usually last around 15 minutes. They ordinarily occur in mid-to-late afternoon.