Hails

Hail is a form of solid precipitation consisting of ice pellets that form inside strong thunderstorms. Hailstones develop as updrafts in cumulonimbus clouds repeatedly lift droplets above the freezing level, where they accrete ice and grow. As a storm's updrafts keep the stones suspended, they can accumulate concentric layers. When the hailstones become too heavy for the updraft to support, they fall to the ground as hail, often traveling with gusty winds.

Hail differs from sleet and from graupel. Sleet forms when raindrops freeze before they reach the ground, while graupel consists of soft, snow-like pellets. Hail typically requires very strong vertical air motions and a substantial supercooled water content, and is more common in regions with intense convective activity. Hail sizes vary from small pellets to several centimeters in diameter; exceptionally large hailstones can exceed 5 cm.

Meteorologists detect and study hail using weather radar, surface hail pads, and observations during and after storms. Areas with frequent intense thunderstorms, such as temperate regions in late spring and early summer, have higher hail risk. Hail can cause property damage, crop losses, and personal injury, and is a factor in insurance claims and disaster reporting.

Mitigation and safety measures focus on sheltering indoors during storms, protecting vehicles and crops, and, in some regions, evaluating hail suppression experiments regarding cloud seeding; however, their effectiveness remains uncertain. Understanding hail formation and monitoring thunderstorms help improve forecasts and reduce its impacts.