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Tornado

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Tornado
AnF3tornado nearAnadarko, Oklahoma,1999.
SeasonPrimarilyspringandsummer,but can be at any time of year
EffectWind damage

Atornadois a tube of violently spinningairthat touches theground.Windinside the tornado spins fast, but the actual 'circle' of wind around them is huge. This makes tornadoes very dangerous.[1]Tornadoes are especially dangerous to people in cars, trucks, buses or mobile homes and about 60 people are killed by tornadoes every year. The word "tornado" might come from theSpanishwordtronada(thunderstorm), which comes from the wordtronar(to thunder).[2]

Tornadoes destroy things – they can tear houses to pieces. Cars and trucks may be thrown away and often leave peoplehomeless.Tornadoes can be caused by winds that have been going opposite directions withhumidity.They are smaller than hurricanes but stronger. Nearly three quarters of the world's tornadoes happen in theUnited States.However, they can happen anywhere.

Tornadoes mostly happen during strongthunderstormscalledsupercellstorms. They cause a lot of damage to anything in their path. Tornadoes are ranked on the EnhancedFujita scale,from EF0 to EF5. EF0 is used for tornadoes that cause the least amount of damage, and EF5 is used for tornadoes that cause the most amount of damage.[3]

Tornadoes can happen in nearly any part of the world. In theUnited States,a tornado has happened in every state. The middle part of the United States is nicknamed "Tornado Alley"because of the number of tornadoes there. A tornado can have wind speeds of over 300 miles per hour (480 km/h). Most tornadoes have wind speeds less than 110 miles per hour (180 km/h), are about 250 feet (80 m) across and travel a few miles before disappearing. Other tornado-like phenomena that exist in nature include the gustnado, dust devil,fire whirls,and steam devil; downbursts are frequently confused with tornadoes, though their action is not similar.

Characteristics[change|change source]

Condensation funnel[change|change source]

A tornado does not necessarily need to be visible; however, the extremely low pressure caused by the high wind speeds and rapid rotation usually causeswater vaporin the air to condense into a visiblecondensation funnel.The tornado is thevortexofwind,not the condensationcloud.

Tornado family[change|change source]

A single storm may produce multiple tornadoes andmesocyclones.Tornadoes produced from the same storm are referred to as atornado family.Sometimes multiple tornadoes from distinct mesocyclones occur at the same time.[4]

Occasionally, several tornadoes are spawned from the same very large storm. If there is no break in their activity, this is considered atornado outbreak,although there are various definitions. A period of several successive days with tornado outbreaks in the same general area (spawned by multiple weather systems) is atornado outbreak sequence,occasionally called an extended tornado outbreak.[1][5]

Sometimes, tornadoes happen in groups.[6]148 tornadoes struck on the same day in April 1974. Many towns in the midwesternUnited StatesandCanadawere destroyed. More than 300 people died.[6]They were hit by flying wrecks, buried underhouses,and thrown by powerful winds. That day, students in Xenia, Ohio were practicing for a play on the auditorium stage. One girl looked out the window and saw the tornado. The students ran into the hall, covering their heads. A few seconds later, all the school buses flew right onto the stage.[6]

A man in another town hid under the couch in hisliving room.He held onto one couch leg. The tornado struck his house, and winds blew around him. When the tornado left, he was outside. There was no house. The couch had disappeared, and he was only holding onto one couch leg.[6]

Damage scale[change|change source]

Tornado rating classifications[7][8]
F0
EF0 		F1
EF1 		F2
EF2 		F3
EF3 		F4
EF4 		F5
EF5
Weak Strong Violent
Significant
Intense
See the main article:Tornado intensity and damage
See also:Enhanced Fujita scale,Fujita scale,andTORRO scale

The Fujita scale and the Enhanced Fujita Scale rate tornadoes by how much damage they cause. The Enhanced Fujita (EF) Scale was an update to the older Fujita scale. The updated scale uses engineered wind estimates and has better damage descriptions. The EF Scale was designed so that a tornado rated on the Fujita scale would get the same numerical rating, and was used in the United States since 2007. An EF0 tornado will probably damage trees but not big buildings, whereas anEF5tornado can rip buildings off their foundations leaving them destroyed and even damage bigskyscrapers.

In the United States, 80% of tornadoes are EF0 and EF1 (T0 through T3) tornadoes. Less than 1% of tornadoes are violent tornadoes (EF4, T8 or stronger).[9]

Tornado watches/warnings/emergencies[change|change source]

A home damaged by an F3 tornado in Forney, Texas

A "tornado watch" is given when theweatherconditions look like a tornado could form. A 'PDS (Particularly Dangerous Situation)' watch is given when a likely tornado outbreak is to start, many strong tornadoes will form in the area, or an ongoing tornado outbreak is in the works in the area. A "tornado warning"is given if somebody has actually seen a tornado or if a tornado 'signature' (usually the storm has a'hook' or 'U' echo) has shown up onradar.[10]Tornado emergenciesare issued in Special Weather Statements or Tornado Warnings saying that a powerful tornado is about to hit an area with a lot of people in it (especially cities in Tornado Alley), a tornado has been spotted, and the tornado is expected to cause deaths.

Myths and misconceptions[change|change source]

The1999 Salt Lake City tornadodisproved several misconceptions, including the idea that tornadoes cannot happen in cities.

It is often thought that opening windows will lessen the damage caused by a tornado. While there is a big drop inatmospheric pressureinside a strong tornado, it is unlikely that the pressure drop would be enough to cause the house to explode. Opening windows may actually increase the tornado's damage.[11]A violent tornado can destroy a house whether its windows are open or closed.[11][12] Another common misconception is that highway overpasses provide adequate shelter from tornadoes. Due to theVenturi effect,tornadic winds are stronger in the small space of an overpass.[13]In the1999 Oklahoma tornado outbreakof May 3, 1999, three highway overpasses were directly hit by tornadoes. At each of the three places there was a death, along with many life-threatening injuries.[14]By comparison, during the same tornado outbreak, more than 2000 homes were completely destroyed, with another 7000 damaged, and yet only a few dozen people died in their homes.[15]

There are areas which people believe to be safe from tornadoes, whether by being in a city, near a major river, hill, or mountain, or even protected bysupernaturalforces.[16]Tornadoes have been known to cross major rivers, climb mountains,[17]hit valleys, and have damagedseveral city centers.As a general rule, no area is safe from tornadoes, though some areas are more likely to be hit than others.[11][12][18]

Safety tips[change|change source]

To keep safe in a tornado, here are some tips people can follow:[19]

  • Go to the lowestfloorof the building. Stay close to the center of thebuildingand away fromwindows,for example, a bathroom with no windows and get into the bathtub.
  • Find a piece of strong furniture or a mattress to go under or hide in a closet and wait until it is over.
  • If inside a school, donotgo to the gymnasium or any other place that has a high ceiling. Squat near the wall, placing the hands on the back of the head.
  • If shelter is not available, find the lowest, most protected ground and cover the head with the hands.
  • Do not drive in tornadoes. If a person finds themselves in their car, they should position their head above the steering wheel, and cover themselves up.
  • Do not seek shelter underneath an underpass or a bridge, as winds can send debris into it.

Related pages[change|change source]

References[change|change source]

  1. ↑1.01.1"Glossary of Meteorology, 2nd ed".American Meteorological Society. 2000. Archived fromthe originalon 2007-04-06.Retrieved2006-11-17.
  2. ↑Harper, Douglas."Etymology of tornado".Online Etymology Dictionary.Retrieved2022-04-13.
  3. ↑"Fujita Tornado Damage Scale".www.spc.noaa.gov.Retrieved2017-11-01.
  4. ↑Branick, Michael (2006)."A Comprehensive Glossary of Weather Terms for Storm Spotters".NOAA. Archived from the original on 2003-08-03.Retrieved2007-02-27.{{cite web}}:CS1 maint: bot: original URL status unknown (link)
  5. ↑Dylan J. Livengood; Harold E. Brooks, and Joseph T. Schaefer (2004)."Tornado Outbreak Day Sequences: Historic Events and Climatology (1875–2003)"(PDF).Archived fromthe original(PDF)on 2006-05-01.Retrieved2007-03-20.
  6. ↑6.06.16.26.3Herman, Gail (15 May 2010).Storm Chasers.New York: Penguin Group.ISBN978-0-448-43337-0.
  7. ↑Thomas P Grazulis (July 1993).Significant Tornadoes 1680–1991.St. Johnsbury, VT: The Tornado Project of Environmental Films.ISBN978-1-879362-03-1.
  8. ↑ "The Fujita Scale of Tornado Intensity".Archived fromthe originalon 2011-12-30.Retrieved2013-05-08.
  9. ↑Edwards, Moller, Purpura; et al. (1998-03-31)."Basic Spotters' Field Guide"(PDF).National Weather Service.National Oceanic and Atmospheric Administration. Archived fromthe original(PDF)on 2010-08-08.Retrieved2006-11-01.{{cite web}}:CS1 maint: multiple names: authors list (link)
  10. ↑"Tornado Season, Watches, and Warnings".Archived fromthe originalon 2010-08-12.Retrieved2010-08-27.
  11. ↑11.011.111.2Tim Marshall (2005-03-15)."Myths and Misconceptions about Tornadoes".The Tornado Project.Retrieved2007-02-28.
  12. ↑12.012.1Thomas P Grazulis (2001). "Tornado Myths".The Tornado: Nature's Ultimate Windstorm.University of Oklahoma Press.ISBN978-0-8061-3258-7.
  13. ↑Climate Services and Monitoring Division (2006-08-17)."Tornado Myths, Facts, and Safety".National Climatic Data Center. Archived from the original on 2012-08-05.Retrieved2012-03-27.{{cite web}}:CS1 maint: bot: original URL status unknown (link)
  14. ↑Chris Cappella (2005-05-17)."Overpasses are tornado death traps".USA Today.Archived fromthe originalon 2005-04-08.Retrieved2007-02-28.
  15. ↑"Highway Overpasses as Tornado Shelters".National Weather Service.National Oceanic and Atmospheric Administration. 2000-03-01. Archived fromthe originalon 2000-06-16.Retrieved2007-02-28.
  16. ↑Kenneth F Dewey (2002-07-11)."Tornado Myths & Tornado Reality".High Plains Regional Climate Center andUniversity of Nebraska–Lincoln.Archived fromthe originalon June 11, 2008.Retrieved2009-11-17.
  17. ↑John Monteverdi; Roger Edwards; Greg Stumpf; Daniel Gudgel (2006-09-13)."Tornado, Rockwell Pass, Sequoia National Park, 2004-07-07".Archived fromthe originalon 2015-08-19.Retrieved2009-11-19.
  18. ↑Walter A Lyons (1997)."Tornadoes".The Handy Weather Answer Book(2nd ed.).Detroit, Michigan:Visible Ink press. pp.175–200.ISBN978-0-7876-1034-0.
  19. ↑Oard, Michael (1997).The Weather Book.P.O. Box 126, Green Forest, AR 72638: Master Books.ISBN0-89051-211-6.{{cite book}}:CS1 maint: location (link)

Other websites[change|change source]

Wikimedia Commons has media related toTornadoes.
CyclonesandTropical cyclonesof the World
Cyclone-Tropical-Extratropical-Subtropical-Mesocyclone-Polar cyclone-Polar low
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