The word "TORNADO" comes from the Spanish word for "TURNED", which in turn comes from the Latin word torqueo, meaning "TO TWIST." Some common, related slang terms include: twister, whirlwind, wedge, funnel, willy-willy, or rope.

A Tornado is a violently spinning column of air in contact with both a cumiliform cloud base and the surface. A tornado is typically shaped like a funnel with the narrow end on the ground.

Tornadoes are known for being extremely destructive and are usually visible due to water vapor from clouds and debris from the ground.

They have been recorded in all fifty U.S. states, they form most famously in a broad area of the American Great Plains, Midwest, as well as South known colloquially as Tornado Alley. In pure number of incidences, the United States reports more tornadoes than any other country, however, the Netherlands is the most tornado-prone country relative to land area.

Tornadoes normally rotate in a cyclonic (counterclockwise) direction. In the United States (and predominately worldwide), the intensity of a tornado is measured on the FUJITA-PEARSON Tornado Scale (also known simply as Fujita scale).

The TORRO scale, developed in the United Kingdom by the Tornado and Storm Research Organisation (TORRO) and used primarily in the U.K.