Hail is a form of precipitation composed of lumps of ice that fall from severe thunderstorms, specifically those with strong updrafts. Unlike sleet or snow, hailstones are solid ice spheres or irregularly shaped masses that do not melt before reaching the ground. The physical consequences of this phenomenon are often destructive, stemming from the transfer of significant kinetic energy upon impact. This article examines the tangible effects of hail, focusing on its impact on stationary property, cultivated resources, and biological life.
Impact on Built Structures
The damage inflicted on man-made structures is directly related to the hailstone’s kinetic energy, which increases exponentially with its size and velocity. This energy transfer upon contact leads to physical degradation of building materials and vehicles. Damage to roofing is a primary concern, as materials like asphalt shingles suffer from granule loss, which exposes the underlying mat to ultraviolet light and shortens the roof’s lifespan.
Metal roofing can be severely dented, compromising its aesthetic value, though its structural integrity often remains intact against smaller hail. Brittle materials such as clay or concrete tiles, along with wood shakes, are prone to cracking, splitting, or shattering. Vehicles are also highly vulnerable, sustaining countless dents on body panels and damage to glass components. Large hailstones can shatter windshields and side windows, while smaller impacts can crack the glass and compromise the protective shell.
The impact force can also break window seals and frames, creating hidden damage that leads to air drafts and moisture intrusion. This damage reduces energy efficiency and creates conditions for mold growth inside a structure. The resulting need for assessment and repair generates billions in insurance claims annually, making hail one of the most costly weather events for property owners.
Destruction of Agricultural Resources
A hailstorm can instantly ruin entire harvests, earning it the moniker of the “white combine” among farmers. The physical assault on field crops, such as corn and soybeans, results in shredded or stripped leaves, severely limiting the plant’s ability to photosynthesize. Bruising and breakage along the stem or stalk also provide entry points for pathogens, leading to secondary infection and further loss. For corn, a direct hit to the growing point after the V6 stage can kill the plant, resulting in zero yield.
In orchards and vineyards, hail damage is often more complex and long-lasting, affecting perennial plants. Hailstones tear leaves, bruise shoots, and cause open wounds on the woody trunk and canes, creating avenues for diseases like Crown Gall. Fruit that is not knocked to the ground may be scarred or bruised, rendering it unmarketable or vulnerable to rot from fungi like Botrytis.
The impact on livestock is also a concern for farmers. Large hailstones, typically 3.75 inches or greater in diameter, can cause severe bruising in open-pasture cattle. If animals are sent to market too soon after a storm, this bruising can lead to significant trim loss and reduced carcass value.
Immediate Safety Hazards to Life
The direct threat hail poses to people and animals is related to the hailstone’s size and its terminal velocity. A hailstone’s speed is a combination of its terminal velocity and any wind component, which can propel it into a trajectory more damaging than a purely vertical drop. A small hailstone (around 1 centimeter) might fall at approximately 45 miles per hour, but larger stones (5 centimeters or more) can exceed 100 miles per hour.
This high-speed impact can result in blunt force trauma, with severity ranging from minor contusions to life-threatening injuries. Smaller hailstones generally cause stinging sensations and minor bruising. Larger ones are capable of causing deep lacerations and concussions upon striking the head. In rare cases involving exceptionally large hailstones, the impact energy is sufficient to cause severe head trauma, skull fractures, or fatalities.
The immediate protective measure is always to seek substantial shelter, as the ice masses can strike with energy comparable to a projectile. The unpredictable nature of a hailstorm means that the speed and angle of impact can vary dramatically, making any exposure a significant risk to biological tissue.