Tornadoes are sometimes called twisters.
Tornadoes in the United States are simply called tornadoes. In informal contexts they are sometimes called twisters.
Tornadoes in the U.S. are called tornadoes.
Tornadoes are sometimes called twisters, but tornado is the preferred scientific term.
Tornadoes are formally called tornadoes.
Smaller tornadoes near a larger tornadoes are often called satellite tornadoes. Smaller vortices within a tornado are called subvorticies or suction vorticies.
When two tornadoes merge, it is just called merging; there is no special term.
Tornadoes on water are called waterspouts.
Tornadoes are often called twisters.
Enormous vortices have been observed on the sun that resemble tornadoes. They have been called "solar tornadoes" but they are not tornadoes by the meteorological definition.
Enormous vortices have been observed on the sun that resemble tornadoes. They have been called "solar tornadoes" but they are not tornadoes by the meteorological definition.
Sometimes tornadoes are called tornadoes, though it is technically incorrect to do so.