What is the definition of hail (GR)?

Hail is defined as balls or other pieces of ice that have diameters greater than 0.2 inches. This definition highlights the specific characteristics of hail, distinguishing it from other forms of precipitation. Unlike ice crystals, which are smaller and typically form in clouds in the coldest parts of the atmosphere, hail forms during severe thunderstorms where strong updrafts carry water droplets into extremely cold areas of the atmosphere. When these droplets are lifted high enough, they freeze and accumulate layers of ice, creating larger ice pellets, which we recognize as hail.

The reference to "greater than 0.2 inches" in diameter is critical, as it sets an important threshold that differentiates hail from other types of frozen precipitation, such as sleet, which involves smaller ice pellets and typically occurs under different meteorological conditions. Understanding hail is crucial for pilots and meteorologists because it can pose significant hazards during flight operations.