How A Tornado Works

A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud. It typically has a narrow, funnel-shaped appearance, with a wide base and a tapering top. The funnel shape is formed as the rotating air rises and condenses, creating a visible vortex. This shape allows the tornado to efficiently channel and concentrate its destructive power. Therefore, the correct answer is funnel shaped.

A funnel cloud is the term used to describe a tornado that has not yet touched the ground. It is a rotating, cone-shaped cloud that extends from the base of a thunderstorm towards the ground. Funnel clouds are often associated with severe weather conditions and can be a precursor to the formation of a tornado. Once a funnel cloud makes contact with the ground, it becomes a tornado.

A tornado is a wind-based event because it is a violent and rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud. The strong winds within a tornado can cause significant damage to structures and the environment. Therefore, it is accurate to say that a tornado is a wind-based event.

Tornadoes normally form from a class of thunderstorms called supercells. Supercells are large, powerful thunderstorms that have a rotating updraft. These storms are characterized by a persistent, rotating updraft called a mesocyclone, which provides the necessary conditions for tornado formation. Supercells are capable of producing severe weather, including large hail, damaging winds, and tornadoes. The rotation within a supercell allows for the development of a strong, low-level mesocyclone, which can then produce a tornado. Tornadoes are most commonly associated with supercell thunderstorms, making supercells the correct answer.

The statement is false because most tornadoes have wind speeds much higher than 20-45 mph. Tornadoes are known for their violent and destructive nature, with wind speeds typically ranging from 65-110 mph or even higher. Therefore, the given statement is incorrect.