No. General scientific consensus is that most tornadoes start forming up inside a thunderstorm and extend downward. There is evidence that some tornadoes form from the ground up, however.
No. A tornado starts in the clouds and extends towards the ground. Until it reaches the ground it is not a tornado but a funnel cloud.
A tornado that does not touch the ground is a funnel cloud.
Yes
The Tuscaloosa-Birmingham tornado of 2011 was on the ground for about 90 minutes.
Usually. If you see rotation in the clouds it means a tornado may form. If you see a cone, cyclinder, or "elephant trunk" shaped cloud extending from cloud base a tornado may already be on the ground.
When a tornado first reaches the ground and becomes a tornado it is said to have touched down.
Before it reaches the ground, the precursor to a tornado is called a funnel cloud.
Tornadoes fluctuate in intensity. An F5 tornado is only at F5 strength for part of the time it is on the ground.
A tornado is considered a tornado when it reaches the ground
No. A tornado starts in the clouds and extends towards the ground. Until it reaches the ground it is not a tornado but a funnel cloud.
A tornado that does not touch the ground is a funnel cloud.
A tornado becomes a tornado when the circulation reaches the ground.
A tornado often appears dark were it is touching the ground be cause the powerful winds of the tornado lift dirt from the ground.
Yes
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.
The intensity of a tornado is rated based on damage done on the ground.
The Tuscaloosa-Birmingham tornado of 2011 was on the ground for about 90 minutes.