S: http://www.redcross.org/mobile-apps/tornado-app/setup-alerts (last access: 3 July 2015); http://www.prep4agthreats.org/Natural-Disasters/tornadoes (last access: 3 July 2015)
N: 1. 1550s, ternado, navigator’s word for violent windy thunderstorm in the tropical Atlantic, probably a mangled borrowing from Spanish tronada “thunderstorm,” from tronar “to thunder,” from Latin tonare “to thunder”. Also in 17c. spelled tornatho, tornathe, turnado; modern spelling by 1620s. Metathesis of -o- and -r- in modern spelling influenced by Spanish tornar “to twist, turn,” from Latin tornare “to turn.” Meaning “extremely violent whirlwind” is first found 1620s; specifically “destructive rotary funnel cloud” (especially in the U.S. Midwest) from 1849. Related: Tornadic.
2. A severe rotating windstorm of small diameter and great destructive power. It is the most violent natural meteorological phenomenon. With certain frequency they can occur within hurricanes circulation. Although tornadoes occur over land areas in many parts of the world associated with several weather situations, they are relatively frequent in the foreward portion of the hurricane periphery.
3. A violently rotating storm of small diameter; the most violent weather phenomenon. It is produced in a very severe thunderstorm and appears as a funnel cloud extending from the base of a Cumulonimbus to the ground. (GLIDE)
4. Cultural Interrelation: We can mention an American Native Legend (a Caddo Legend) called Coyote and the origin of Death.
S: 1. OED – http://www.etymonline.com/index.php?term=tornado (last access: 3 July 2015). 2. METEOTERM/IMV/WMO (last access: 3 July 2015). 3. RWP – http://www.who.int/hac/about/reliefweb-aug2008.pdf (last access: 4 August 2015) (p. 53). 4. http://www.native-languages.org/legends-tornado.htm (last access: 3 July 2015).
CR: cyclogenesis, cyclone, disasters, explosive cyclogenesis, hurricane, storm, thunderstorm.