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
Altocumulus castellanus cloud Altocumulus castellanus cloud In meteorology, Altocumulus Castellanus (ACCAS) is a cloud type named for its tower-like projections that billow upwards from the base of the cloud. The base of the cloud can form as low as 2,000 metres (6,500 feet), or as high as 6,000 metres (20,000 feet). They are very similar to cumulus congestus clouds, but at a higher level and with the cloud heaps joined at the base. Castellanus clouds are evidence of mid-atmospheric instability and a high mid-altitude lapse rate. They may be a harbinger of heavy showers and thunderstorms and, if surface-based convection can connect to