funnel cloud(redirected from Cold air funnel)
Also found in: Encyclopedia.
A funnel-shaped cloud descending from a larger cloud, especially from a wall cloud, caused by the sudden condensation of water in the extreme low pressure of rapidly rotating air, as typically occurs in a tornado.
(Physical Geography) a whirling column of cloud extending downwards from the base of a cumulonimbus cloud: part of a waterspout or tornado
a rapidly rotating funnel-shaped cloud extending downward from the base of a cumulonimbus cloud, which, if it touches the surface of the earth, is a tornado or waterspout.