The speed, beauty and absolutely intimidating sight of tornadoes have haunted the minds and attracted the curiosity of many. As Mother Nature's most violent windstorms, tornadoes don't just pick you up and transport you to the magical land of Oz. On the contrary, they usually throw you away like a rag doll, leaving disaster behind them. Interestingly, tornadoes are not yet fully understood. We know what a tornado is and how it forms, but why it forms in various circumstances and not others is still under scrutiny. According to Ahrens (2009), a tornado is defined as "a rapidly rotating column of air that blows around a small area of ​​intense low pressure extending from the base of a thunderstorm to the Earth's surface » (p. 394). Tornadoes can form in two ways, either by a supercell thunderstorm or by a non-supercell thunderstorm (Ahrens, 2009). A supercell thunderstorm forms when the ground warms in spring and summer and the air above the ground is cold (Ahrens, 2009). Warm air near the surface rises, as it cools, the water vapor it carries condenses to form cumulus clouds and eventually transform into cumulonimbus clouds (Ahrens, 2009). Winds near the surface blow in one direction while winds higher up blow in another; the difference creates a horizontally rotating air mass (Ahrens, 2009). Rising warm air pushes horizontally rotating air upward, creating a mesocyclone that is typically 2 to 6 miles wide (Nation Severe Storms Laboratory [NSSL], 1992). These rotating updrafts define a supercell thunderstorm and set the stage for possible tornadoes (Ahrens, 2009). Tornadoes typically occur in the tail portion of a supercell thunderstorm (Ahrens, 2009). This is said to be due to the timing ...... middle of paper ...... nadoes will continue to be unpredictable. Works Cited Ahrens, CD (2009). Meteorology Today: An Introduction to Weather, Climate, and the Environment (9th ed.). Belmont, CA: Cengage. Knight, M. (2007, 06 14). Fact or fiction? : If the sky is green, run for cover: a tornado is coming: Scientific American. Retrieved from http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-if-sky-is-green-run-for-cover-tornado-is-comingNation Severe Storms Laboratory (1992, 09 ). Tornadoes. Retrieved from: http://www.nssl.noaa.gov/edu/safety/tornadoguide.htmlNational Severe Storm Laboratory (2009, 07 20). Tornado Basics Retrieved from: http://www.nssl.noaa.gov/primer/tornado/tor_basics.html#Smith, R. (1996, 02 15). Non-supercell tornadoes: a review for forecasters. Retrieved from: http://www.srh.noaa.gov/topics/attach/html/ssd96-8.htm