Hailstorms

Hailstorms are weather events in which hail, hard ice spheres or irregular chunks, falls to the ground from thunderclouds. Hail is produced when strong updrafts within a cumulonimbus cloud repeatedly lift water droplets above the freezing level, allowing layered ice to accumulate. The size and distribution of hail depend on storm dynamics, atmospheric moisture, and how long the hailstone remains aloft.

Hailstone sizes vary from small pellets to golf ball size or larger. Large hail requires powerful updrafts and extended residence in the cloud, often with supercell thunderstorms. Most hail falls during spring and early summer in temperate regions; severe events are episodic and localized and can produce significant property damage in a short period.

Impacts include damage to vehicles, roofs, and windows, as well as agricultural losses and injuries to people and animals. Hail can disrupt transportation, disrupt service infrastructure, and generate substantial economic costs in both insured and uninsured sectors.

Detection and forecasts rely on weather radar to identify hail-producing storms through reflectivity patterns and, increasingly, debris signatures. Dual-polarization radar helps discriminate hail from rain. Weather warnings and watches inform the public and responders, but predicting the exact size and timing of hail remains uncertain.

Mitigation strategies emphasize protective construction and barriers. Protective coatings, hail nets for orchards and greenhouses, sheltered parking, and reinforced roof materials can reduce damage. Early warnings enable people to seek shelter. Hail suppression efforts have not demonstrated reliable, large-scale effectiveness and are not widely practiced.