Hail

urn:aero:airm:1.0.0:ConceptualModel:Subjects:Meteorology:Hail

Precipitation of either transparent, or partly or completely opaque particles of ice (hailstones), usually spheroidal, conical or irregular in form and of diameter very generally between 5 and 50 millimetres, which falls from a cloud either separately or agglomerated into irregular lumps.

Source: WMO International Meteorological Vocabulary,