Hector (cloud) Hector (cloud) Hector is the name given to a cumulonimbus, or thundercloud, that forms regularly nearly every afternoon on the Tiwi Islands in the Northern Territory of Australia, from approximately September to March each year. Hector, or sometimes "Hector the Convector", is known as one of the world's most consistently large thunderstorms, reaching heights of approximately . Named by pilots during the Second World War, the recurring position of the thunderstorm made it a navigational beacon for pilots and mariners in the region. Hector is caused primarily by a collision of several sea breeze boundaries across the Tiwi Islands and
Cloud of a squall line or thunderstorm outflow. A large arcus formation can have the appearance of a dark menacing arch. Several new supplementary features have been formally recognized by the World Meteorological Organization (WMO). The feature "fluctus" can form under conditions of strong atmospheric wind shear when a stratocumulus, altocumulus, or cirrus cloud breaks into regularly spaced crests. This variant is sometimes known informally as a Kelvin–Helmholtz (wave) cloud. This phenomenon has also been observed in cloud formations over other planets and even in the sun's atmosphere. Another highly disturbed but more chaotic wave-like cloud feature associated with stratocumulus or