text: definition: a tornado is a violently rotating, tall, narrow column of air (vortex), typically about 300 ft (100 m) in diameter, that extends to the ground from a cumulonimbus cloud.\n\nCause:The tornado begins outside the precipitation region as a dust whirl on the ground and a short funnel pendant from a wall cloud on the southwest side of the thunderstorm; it intensifies as the funnel lengthens downward, and attains its greatest power as the funnel reaches its greatest width and is almost vertical; then it shrinks and becomes more tilted, and finally becomes contorted and ropelike as it decays. A downdraft and curtain of rain and large hail gradually spiral from the northeast cyclonically around the tornado, which often ends its life in rain!!!!!