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:

    Whoever digs a pit will fall into it; and whoever breaks through a wall will be bitten by a snake.
    Bible: Hebrew, Ecclesiastes 10:8.

    On a starred night Prince Lucifer uprose,
    Tired of his dark dominion, swung the fiend
    Above the rolling ball in cloud part screened,
    George Meredith (1828–1909)