A wall cloud (or pedestal cloud) is a large, lowering cloud formation that develops beneath the base of a cumulonimbus cloud that often forms tornadoes. It is typically beneath the rain-free base (RFB) portion of a thunderstorm, and indicates the area of the strongest updraft within a storm. Wall clouds are sometimes an indication of a rotating mesocyclone in a thunderstorm, and most strong tornadoes form from wall clouds. However, wall clouds do not always rotate.
Read more about Wall Cloud: Genesis, Structure, Supercell and Tornado Significance
Famous quotes containing the words wall and/or cloud:
“And ye shall know the truth, and the truth shall make you free.”
—Bible: New Testament Jesus, in John, 8:32.
These words are inscribed on the wall of the main lobby at the CIA headquarters, Langley, Virginia.
“The sea was wet as wet could be,
The sands were dry as dry.
You could not see a cloud, because
No cloud was in the sky:
No birds were flying overhead—
There were no birds to fly.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)