cumulonimbus
More commonly known as thunderclouds, cumulonimbus is the only cloud type that can produce hail, thunder and lightning.
Cumulonimbus (from Latin cumulus, "heaped" and nimbus, "rainstorm") is a dense, towering vertical cloud,[1] forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes and hailstones. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell. Cumulonimbus is abbreviated Cb.
