human
What is the difference between a tornado and a funnel cloud?
assistant
A tornado is a rapidly rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It usually has a narrow, funnel-shaped cloud at its base and is often accompanied by loud thunder and sometimes heavy rain or hail. Funnel clouds are similar but lack the rotation and tend to be more localized and short-lived.