Wall Cloud

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:

    “Mountain, mountain, mountain,
    marking time. Each
    nameless, wall beyond wall, wavering
    redefinition of
    horizon.”
    —Denise Levertov (b. 1923)

    “Genius detects through the fly, through the caterpillar, through the grub, through the egg, the constant individual; through countless individuals the fixed species; through many species the genus; through all genera the steadfast type; through all the kingdoms of organized life the eternal unity. Nature is a mutable cloud which is always and never the same.”
    —Ralph Waldo Emerson (1803–1882)