Types of Tornados
A tornado is a violent spinning storm typically shaped like a funnel with the narrow end on the ground. Tornados are known for being extremely destructive and are almost always visible due to water vapor from clouds and debri from the ground. Tornadoes form in storms all over the world, and though they have been recorded in all 50 U.S. states, they form most famously in a broad area of the American Midwest and South known as Tornado Alley. Although, in pure number of incidences, the United States experiences more tornadoes than any other country, the United Kingdom is the most tornado-prone country relative to land area.
The Word "Tornado"
The word "tornado" comes from the Spanish or Portuguese verb tornar, meaning "to turn." Some common, related slang terms include: twister, whirlwind, wedge, funnel, willy-willy, or rope.
Cyclone is also another term for a tornado, although it must be noted that in parts of the world (notably Australia) a cyclone refers to what is more correctly known as a tropical cyclone (also known as a hurricane, or a typhoon), and meteorologists use the term cyclone to refer to a wide range of circular weather systems (using adjectives to disambiguate).
Thunderstorms and Waterspouts
In general tornadoes are associated with a thunderstorm however National Weather Service in the United States considers all waterspouts, including "fair weather" waterspouts, to be tornadoes. Larger vortexes not associated with a thunderstorm are sometimes called landspouts.
Dust devils are small vortexes that form near the ground, which may or may not be considered tornadoes.
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