“No wind-measuring instrument has ever survived the impact of a full tornado” (Ludlum 112). Tornadoes are one of the most destructive natural disasters on earth (“Tornado”).
Tornadoes can generate winds in the three hundred mile per hour range. They have been reported on all continents except Antarctica. Tornadoes may occur wherever conditions favour the development of strong thunderstorms. Tornado alley is the region of maximum tornado frequency. Tornado alley starts in western Texas and extends through the western and central portions of Oklahoma, Kansas, and Nebraska (“Tornado”).
Tornadoes are most frequent from mid afternoon to early evening. The majority of all tornadoes develop in the spring and summer. 74% of all tornadoes are reported from March through July. Tornadoes in the United States often occur between five and six pm. Most tornadoes last for about two or three minutes, violent events may last over three hours. The average tornado moves at a speed of twenty-eight miles per hour. Some tornadoes have even reached high speeds of seventy-five miles per hour (“Tornado”).
A tornado outbreak occurs when several tornadoes form over a region. Outbreaks are usually created by thunderstorms in the same weather system. Small outbreaks include six to nine tornadoes, medium outbreaks include ten to nineteen, and large outbreaks include more than twenty tornadoes (“Tornado”).
Radars and satellite sensors are used by the National Weather Service to monitor the development of tornadoes. These tools help forecasters estimate the intensity of storms and tornadoes. A funnel cloud is a tapered column of water droplets that extends down from the base of the parent cloud. Throughout the nineteen hundreds, tornadoes claimed over 12,282 lives in the united states. Most deaths are caused by individuals being struck by flying debris (“Tornado”).
The twenty thirteen tornado of Moore, Oklahoma was a large and powerful EF five tornado that destroyed the area. The Moore tornado was formed on May twentieth at two fifty-six pm CDT and dissipated at three thirty-three pm CDT. The tornado had wind speeds up to two hundred ten miles per hour and lasted for twenty-seven minutes. The tornado caused two billion dollars in damage. Roughly twenty-four people were killed and two hundred twelve were injured. Urban search and rescue teams were deployed to the areas affected by the tornado from the Federal Emergency Mgt. Agency (“2013 Moore Tornado”).
The Tuscaloosa-Birmingham tornado of two thousand eleven was rated at an EF four. The tornado began at four forty-three pm and ended at six fourteen pm on April twenty-seven. This tornado killed sixty-five people and injured fifteen hundred. The damage path extended just over eighty miles. The tornado was produced by a supercell thunderstorm that began at two fifty-four pm CDT in Newton County, Mississippi. It dissipated in Macron County, North Carolina at ten eighteen CDT. The supercell lasted for seven hours and twenty-four minutes, traveling over approximately three hundred eighty miles. It produced several strong and powerful tornadoes along the way (“Tuscaloosa-Birmingham”).
The Tuscaloosa-Birmingham tornado began with an EF two rating and strengthened as it crossed the Black Warrior River to an EF four rating. Several buildings were destroyed including the Tuscaloosa County Emergency Operations Center. Other small stores and restaurants were destroyed by the tornado. The Alberta Elementary School suffered nearly complete destruction with only a few parts of walls still standing. The Alberta Park Shopping Center was completely destroyed in the tornado with no walls standing, reduced to a pile of debris on the foundation. The tornado swept away apartment buildings and ripped through many homes and businesses. Almost all trees in the vicinity were blown down or snapped (“Tuscaloosa-Birmingham”).
The Tuscaloosa-Birmingham tornado weakened to an EF three rating and still caused extensive damage to its surroundings. As the tornado moved into the Concord area, it became violent again by increasing to an EF four rating. Cinder block homes were completely destroyed. By the time the tornado reached Interstate sixty-five, it was clear that the storm was losing its energy. The damage included folded light poles and roof damage. The tornado diminished to an EF one and then EF zero rating. Tornado warnings for Central Alabama counties ended at eight pm (“Tuscaloosa-Birmingham”).
A tornado’s devastating wind blasts put all human life in jeopardy by sending dangerous pieces of debris into the air and lifting buildings from their foundations. “A funnel cloud is an incipient tornado whose column does not reach the ground” (Ludlum 107). A whirlwind is a small column of air that rotates and causes little damage but, lifts up paper and leaves as it moves along a street or across fields. They are also known as twisters, frowned on by meteorologists (Ludlum 107). Dust devils and sand devils are spiraling columns of dust or sand filled air that last for a few minutes (Ludlum 109).
A tornado undergoes considerable changes in size, shape, and behavior during its life cycle. A funnel cloud develops within a cumulonimbus cloud and extends toward the ground. When the rotating column of air reaches the ground, it becomes a tornado. In weak tornadoes a dust whirl may be visible before the funnel cloud. “During the tornado’s mature stage, the funnel reaches its greatest width” (Ludlum 109). Skipping may occur along a lengthy path. “At this time the tornado causes severe damage to whatever it encounters” (Ludlum 109).
During the shrinking stage of a tornado, the tunnel of wind narrows and starts to tilt away from its vertical position (Ludlum 109). “At this time the path of damage becomes smaller” (Ludlum 110). “As the tornado decays, the funnel stretches into a rope shape and the visible portion becomes contorted and finally dissipates” (Ludlum 110).
Tornadoes are one of the most destructive natural disasters on earth. “No wind-measuring instrument has ever survived the impact of a full tornado.” They usually last for a few minutes and cause major damage to homes. Tornadoes throw around debris and have the ability to injure many people.
- ‘2013 Moore Tornado.’ Tornado Facts, Lylesoft LLC, www.tornadofacts.net/tornado-records/2013-moore-tornado.html. Accessed 19 Nov. 2018.
- Ludlum, David M. ‘Tornadoes.’ National Audubon Society Field Guide to North American Weather. Chanticleer Press ed., New York, Alfred A. Knopf, Inc., 1991.
- ‘Tornado.’ Britannica School, Encyclopedia Britannica, 11 Aug. 2017. school.eb.com/levels/high/article/tornado/106250. Accessed 13 Nov. 2018.
- ‘Tuscaloosa-Birmingham Tornado – April 27, 2011.’ National Weather Service, Weather Forecast Office, www.weather.gov/bmx/event_04272011tuscbirm. Accessed 20 Nov. 2018.