They are not. Tornadoes frequently cause property damage and can kill and injure people. They can clear out old vegetation, allowing for new growth, but this benefit is minor compared to the harm caused.
The only way tornadoes might be beneficial is that they can clear out old trees, allowing new growth.
Tornadoes are harmful in that they kill and injure people and damage and destroy crops and property. They are not beneficial.
Natural tornadoes are not constructive. They cause damage and kill people, so they are destructive; however, there are people who believe stationary "tornadoes" can be created and used for a source of power. If it is possible, those man-made "tornadoes" would be constructive by providing inexpensive power.
Tornadoes in the U.S. are called tornadoes.
Tornadoes are sometimes divided into "weak" tornadoes "strong" and "violent" tornadoes. Weak tornadoes are those rated EF0 and EF1. Most tornadoes are weak. Strong tornadoes are those rated EF2 and EF3. Violent tornadoes are those rated EF4 and EF5. They are the rarest of tornadoes, only about 1% of tornadoes are this strong.
It depends on what you mean by extreme. Tornadoes of EF4 and EF5 tornadoes, however are often referred to as violent tornadoes. These account for about 1% of all tornadoes.
Tornadoes don't get named, Hurricanes do, but Tornadoes don't.
Florida frequently has tornadoes, though several states have more tornadoes annually.
No. Tornadoes are dangerous.
Yes, some strong tornadoes create brief satellite tornadoes that circle the main funnel.
Antarctica is the continent that does not have tornadoes. Tornadoes typically form over land, so the cold and uninhabited nature of Antarctica makes it unlikely for tornadoes to occur there.
Tornadoes are often referred to simply as "tornadoes" or "twisters."