Funnel cloud Funnel cloud A funnel cloud is a funnel-shaped cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud (usually a cumulonimbus or towering cumulus cloud) but not reaching the ground or a water surface. A funnel cloud is usually visible as a cone-shaped or needle like protuberance from the main cloud base. Funnel clouds form most frequently in association with supercell thunderstorms. If a funnel cloud touches the ground it becomes a tornado. Most tornadoes begin as funnel clouds, but many funnel clouds do not make ground contact and so
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,