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
Wall cloud the wall cloud, as it is also an inflow feature. Most movement is horizontal, but some rising motion is often apparent as well. Some wall clouds also have a band of cloud fragments encircling the top of the wall cloud where it meets the ambient cloud base; this feature is a collar cloud. Another accessory cloud is the flumen, commonly known as the beaver's tail. It is formed by the warm, humid inflow of a strong thunderstorm, and is often mistaken for tornadoes. Although the presence of a flumen is associated with tornado risk, the flumen, similar to scud clouds,