Most of them touch down on ground.
A tornado that does not touch the ground is a funnel cloud.
A funnel cloud that touches the ground is commonly known as a tornado.
A tornado that doesn't touch the ground isn't a tornado; it is a funnel cloud. However if the funnel is pulling debris off the ground or making some other type of contact with the ground it is a tornado.
A tornado often appears dark were it is touching the ground be cause the powerful winds of the tornado lift dirt from the ground.
The Tuscaloosa-Birmingham tornado of 2011 was on the ground for about 90 minutes.
The intensity of a tornado is rated based on damage done on the ground.
Not technically. It is the beginning of a tornado, but they are categorized differently. It is not considered a tornado until it reaches the ground with damaging winds.
When a tornado has not touched the ground yet, it is called a funnel cloud. A funnel cloud is a rotating cone-shaped cloud descending from the base of a thunderstorm but not reaching the ground. Once it touches the ground, it is classified as a tornado.
tornado clouds
True. A tornado is a rapidly rotating column of air that extends from a thunderstorm to the ground, and when it touches the ground it is then classified as a tornado. The funnel cloud is the visible condensation funnel attached to the rotating column of air but becomes a tornado once it touches the ground.
By the meteorological definition a tornado extends from cloud base to the ground. If it does not, it cannot produce damage. However, just because the visible funnel doesn't touch the ground doesn't mean the strong winds don't. It is the vortex of wind which defines a tornado, not the funnel.
A funnel cloud is a rotating column of air that does not reach the ground, while a tornado is a funnel cloud that extends to the ground and causes damage. Both are formed from the same weather conditions and can be associated with severe thunderstorms.