FACTOID # 12: It's not the government they hate: Washington DC has the highest number of hate crimes per capita in the US.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Tornado" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Tornado
A tornado in central Oklahoma. The tornado itself is the thin tube reaching from the cloud to the ground. The lower part of this tornado is surrounded by a translucent dust cloud, kicked up by the tornado's strong winds at the surface
A tornado in central Oklahoma. The tornado itself is the thin tube reaching from the cloud to the ground. The lower part of this tornado is surrounded by a translucent dust cloud, kicked up by the tornado's strong winds at the surface

A tornado is a violently rotating column of air which is in contact with both a cumulonimbus cloud or, in rare cases, a cumulus cloud base and the surface of the earth. Tornadoes come in many sizes but are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris. Look up tornado in Wiktionary, the free dictionary. ... Image File history File links Download high-resolution version (1024x679, 59 KB) One of several tornadoes observed by the VORTEX-99 team on May 3, 1999, in central Oklahoma. ... Image File history File links Download high-resolution version (1024x679, 59 KB) One of several tornadoes observed by the VORTEX-99 team on May 3, 1999, in central Oklahoma. ... For other uses, see Oklahoma (disambiguation). ... Transparent glass ball In optics, transparency is the property of allowing light to pass. ... Cumulonimbus (Cb) is a type of cloud that is tall, dense, and involved in thunderstorms and other intense weather. ... This article or section does not adequately cite its references or sources. ... For other uses, see Condensation (disambiguation). ... A typical kitchen funnel. ... Debris (French, pronounced (IPA) dibri) is a word used to describe the remains of something that has been otherwise destroyed. ...


Most tornadoes have wind speeds between 40 mph (64 km/h) and 110 mph (177 km/h), are approximately 250 feet (75 m) across, and travel a few miles (several kilometers) before dissipating. Some attain wind speeds of more than 300 mph (480 km/h), stretch more than a mile (1.6 km) across, and stay on the ground for dozens of miles (more than 100 km).[1][2][3] Miles per hour is a unit of speed, expressing the number of international miles covered per hour. ... Kilometres per hour (American spelling: kilometers per hour) is a unit of both speed (scalar) and velocity (vector). ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... This article is about the unit of length. ... “Miles” redirects here. ... “km” redirects here. ...


Although tornadoes have been observed on every continent except Antarctica, most occur in the United States.[4] They also commonly occur in southern Canada, south-central and eastern Asia, east-central South America, Southern Africa, northwestern and southeast Europe, Italy, western and southeastern Australia, and New Zealand.[5] For other uses, see Asia (disambiguation). ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... Categories: Africa geography stubs | Southern Africa ... For other uses, see Europe (disambiguation). ...

Part of the Nature series on
Weather
 
Seasons

Spring · Summer
Autumn · Winter This article is about the physical universe. ... For the geological process, see Weathering or Erosion. ... This article or section is in need of attention from an expert on the subject. ... For the usage in virology, see temperate (virology). ... For other uses, see Spring. ... For other uses, see Summer (disambiguation). ... This article is about the temperate season. ... For other uses, see Winter (disambiguation). ...

Dry season
Wet season The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. ... This article or section does not cite any references or sources. ... A wet season or rainy season is a season in which the average rainfall in a region is significantly increased. ...

Storms

Thunderstorm · Tornado
Tropical cyclone (Hurricane)
Extratropical cyclone
Winter storm · Blizzard
Ice storm For other uses, see Storm (disambiguation). ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ... A fictitious synoptic chart of an extratropical cyclone affecting the UK & Ireland. ... A typical view of a winter storm. ... This article is about the winter storm condition. ... Ice storm could refer to: A type of winter storm characterized by freezing rain. ...

Precipitation

Fog · Drizzle · Rain
Freezing rain · Sleet
Hail · Snow For other uses, see Fog (disambiguation). ... Drizzle is fairly steady, light precipitation. ... This article is about precipitation. ... Freezing Rain is a type of precipitation that begins as snow at higher altitude, falling from a cloud towards earth, melts completely on its way down while passing through a layer of air above freezing temperature, and then encounters a layer below freezing at lower level to become supercooled. ... Sleet is a term used in a variety of ways to describe precipitation intermediate between rain and snow but distinct from hail. ... This article is about the precipitation. ... For other uses, see Snow (disambiguation). ...

Topics

Meteorology
Weather forecasting
Climate · Air pollution This page has a list of meteorology topics. ... // Meteorology (from Greek: μετέωρον, meteoron, high in the sky; and λόγος, logos, knowledge) is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. ... Modern weather predictions aid in timely evacuations and potentially save lives and property damage Human beings have attempted to predict the weather since time immemorial. ... Air pollution is the modification of the natural characteristics of the atmosphere by a chemical, particulate matter, or biological agent. ...

Weather Portal
 v  d  e 

Contents

Definitions

A tornado near Seymour, Texas.
A tornado near Seymour, Texas.
Tornado
A tornado is defined by the Glossary of Meteorology as "a violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud..."[6] In practice, for a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base. Scientists have not yet created a complete definition of the word; for example, there is disagreement as to whether separate touchdowns of the same funnel constitute separate tornadoes.[3]
Condensation funnel
A tornado is not necessarily visible; however, the intense low pressure caused by the high wind speeds (see Bernoulli's principle) and rapid rotation (due to cyclostrophic balance) usually causes water vapor in the air to condense into a visible condensation funnel.[4] The tornado is the vortex of wind, not the condensation cloud.
A funnel cloud is a visible condensation funnel with no associated strong winds at the surface. Not all funnel clouds evolve into a tornado. However, many tornadoes are preceded by a funnel cloud. Most tornadoes produce strong winds at the surface while the visible funnel is still above the ground, so it is difficult to discern the difference between a funnel cloud and a tornado from a distance.[3]
Tornado family
Occasionally, a single storm will produce more than one tornado, either simultaneously or in succession. Multiple tornadoes produced by the same storm are referred to as a tornado family. [7]
Tornado outbreak
Occasionally, several tornadoes are spawned from the same large-scale storm system. If there is no break in activity, this is considered a tornado 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 a tornado outbreak sequence, occasionally called an extended tornado outbreak.[6][8][9]

Image File history File links Seymour_Texas_Tornado. ... Image File history File links Seymour_Texas_Tornado. ... Seymour is the county seat and only town in Baylor County, Texas, United StatesGR6. ... A cumulus cloud (Cu) is a cloud belonging to a class characterized by puffs, mounds or towers, with flat bases and tops that often resemble cauliflower. ... A funnel cloud. ... Bernoullis Principle states that for an ideal fluid (low speed air is a good approximation), with no work being performed on the fluid, an increase in velocity occurs simultaneously with decrease in pressure or a change in the fluids gravitational potential energy. ... In Atmospheric Science, Balanced Flow is an idealization of atmospheric motion in which flow is considered steady-state. ... Water vapor or water vapour (see spelling differences), also aqueous vapor, is the gas phase of water. ... Vortex created by the passage of an aircraft wing, revealed by coloured smoke A vortex (pl. ... For other uses, see Wind (disambiguation). ... For other uses, see Cloud (disambiguation). ... A funnel cloud. ... Often mistaken for single long track tornadoes, Tornado families are a series of tornadoes which occur along a similar path. ... While there is no single agreed upon definition, generally more than six tornadoes in a day in the same region is considered a tornado outbreak. ... A tornado outbreak sequence (or extended tornado outbreak) is a period of continuous or near-continuous high tornado activity consisting of a series of tornado outbreaks. ...

Etymology

The word "tornado" is an altered form of the Spanish word tronada, which means "thunderstorm". This in turn was taken from the Latin tonare, meaning "to thunder". It most likely reached its present form through a combination of the Spanish tronada and tornar ("to turn"); however, this may be a folk etymology.[10][11] Tornadoes are also commonly referred to as twisters.[12] Latin was the language originally spoken in the region around Rome called Latium. ... For other uses, see Thunder (disambiguation). ... Folk etymology is a term used in two distinct ways: A commonly held misunderstanding of the origin of a particular word, a false etymology. ...


Types

A multiple-vortex tornado outside of Dallas, Texas on April 2, 1957.
A multiple-vortex tornado outside of Dallas, Texas on April 2, 1957.

Image File history File links 1957_Dallas_multi-vortex_1_edited. ... Image File history File links 1957_Dallas_multi-vortex_1_edited. ... Dallas redirects here. ... is the 92nd day of the year (93rd in leap years) in the Gregorian calendar. ... Year 1957 (MCMLVII) was a common year starting on Tuesday (link displays the 1957 Gregorian calendar). ...

True tornadoes

Multiple vortex tornado
A multiple vortex tornado is a type of tornado in which two or more columns of spinning air rotate around a common center. Multivortex structure can occur in almost any circulation, but is very often observed in intense tornadoes.
Satellite tornado
A satellite tornado is a term for a weaker tornado which forms very near a large, strong tornado contained within the same mesocyclone. The satellite tornado may appear to "orbit" the larger tornado (hence the name), giving the appearance of one, large multi-vortex tornado. However, a satellite tornado is a distinct funnel, and is much smaller than the main funnel.[3]
A waterspout near the Florida Keys.
A waterspout near the Florida Keys.
Waterspout
A waterspout is officially defined by the US National Weather Service simply as a tornado over water. However, researchers typically distinguish "fair weather" waterspouts from tornadic waterspouts.
  • Fair weather waterspouts are less severe but far more common, and are similar in dynamics to dust devils and landspouts.[13] They form at the bases of cumulus congestus cloud towers in tropical and semitropical waters.[13] They have relatively weak winds, smooth laminar walls, and typically travel very slowly, if at all.[13] They occur most commonly in the Florida Keys.[14]
  • Tornadic waterspouts are more literally "tornadoes over water". They can form over water like mesocyclonic tornadoes, or be a land tornado which crosses onto water. Since they form from severe thunderstorms and can be far more intense, faster, and longer-lived than fair weather waterspouts, they are considered far more dangerous.
A landspout near North Platte, Nebraska on May 22, 2004.
A landspout near North Platte, Nebraska on May 22, 2004.
Landspout
Landspout is an unofficial term for a tornado not associated with a mesocyclone. The name stems from their characterization as essentially a "fair weather waterspout on land". Waterspouts and landspouts share many defining characteristics, including relative weakness, short lifespan, and a small, smooth condensation funnel which often does not reach the ground. Landspouts also create a distinctively laminar cloud of dust when they make contact with the ground, due to their differing mechanics from true mesoform tornadoes. Though usually weaker than classic tornadoes, they still produce strong winds and may cause serious damage.[3][15]

A multiple vortex tornado is a tornado that contains several vortices rotating around and inside of and part of the main vortex. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... Image File history File links Trombe. ... Image File history File links Trombe. ... Palm trees in Islamorada The Florida Keys is an archipelago of about 1700 islands in the southeast United States. ... Waterspouts on the beach of Kijkduin near The Hague, the Netherlands on 2006 August 27. ... The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... Dust Devil Johnsonville, South Carolina A dust devil is a rotating updraft, 1000 meters or more high and tens of meters in diameter. ... A landspout is a tornado not associated with the mesocyclone of a thunderstorm. ... Cumulus congestus clouds are characteristic of unstable areas of the atmosphere which are undergoing convection. ... Laminar flow (bottom) and turbulent flow (top) over a submarine hull. ... Palm trees in Islamorada The Florida Keys is an archipelago of about 1700 islands in the southeast United States. ... It has been suggested that this article or section be merged into Supercell. ... A severe thunderstorm is a thunderstorm with winds 58 mph or greater, 3/4 inch or larger hail, or tornadoes. ... Image File history File links GID_Landspout. ... Image File history File links GID_Landspout. ... Grain elevator along the Union Pacific Railroad in downtown North Platte North Platte is a city in Lincoln County in southwestern Nebraska on I-80 where the South Platte River and the North Platte River join to form the Platte River. ... is the 142nd day of the year (143rd in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... A landspout is a tornado not associated with the mesocyclone of a thunderstorm. ... It has been suggested that this article or section be merged into Supercell. ... laminar and turbulent water flow over the hull of a submarine In fluid dynamics, laminar flow is a flow regime characterized by high momentum diffusion, low momentum convection, and pressure and velocity independence from time. ...

Tornado-like circulations

Gustnado
A gustnado (gust front tornado) is a small, vertical swirl associated with a gust front or downburst. Because they are technically not associated with the cloud base, there is some debate as to whether or not gustnadoes are actually tornadoes. They are formed when fast moving cold, dry outflow air from a thunderstorm is blown through a mass of stationary, warm, moist air near the outflow boundary, resulting in a "rolling" effect (often exemplified through a roll cloud). If low level wind shear is strong enough, the rotation can be turned horizontally (or diagonally) and make contact with the ground. The result is a gustnado.[3][16] They usually cause small areas of heavier rotational wind damage among areas of straight-line wind damage. It is also worth noting that since they are absent of any Coriolis influence from a mesocyclone, they seem to be alternately cyclonic and anticyclonic without preference.
Dust devil
A dust devil resembles a tornado in that it is a vertical swirling column of air. However, they form under clear skies and are rarely as strong as even the weakest tornadoes. They form when a strong convective updraft is formed near the ground on a hot day. If there is enough low level wind shear, the column of hot, rising air can develop a small cyclonic motion that can be seen near the ground. They are not considered tornadoes because they form during fair weather and are not associated with any actual cloud. However, they can, on occasion, result in major damage, especially in arid areas.[17][18]
Winter Waterspout
A winter waterspout, also known as a snow devil, an icespout, an ice devil or a snowspout, is an extremely rare meteorological phenomenon in which a vortex resembling that of a waterspout forms under the base of a snow squall.
Fire whirl
Tornado-like circulations occasionally occur near large, intense wildfires and are called fire whirls. They are not considered tornadoes except in the rare case where they connect to a pyrocumulus or other cumuliform cloud above. Fire whirls usually are not as strong as tornadoes associated with thunderstorms. However, they can produce significant damage.[8]
Steam devil
A steam devil is a term describing a rotating updraft that involves steam or smoke. A steam devil is very rare, but they mainly form from smoke emitting from a power plant smokestack. Hot springs and deserts may also be suitable locations for a steam devil to form.
Cold air vortex
A cold air vortex or shear funnel is a tiny, harmless funnel cloud which occasionally forms underneath or on the sides of normal cumuliform clouds, rarely causing any winds at ground-level.[19] Their genesis and mechanics are poorly understood, as they are quite rare, short lived, and hard to spot (due to their non-rotational nature and small size).

A Gustnado is a type of short-lived cyclonic circulation that can form with severe thunderstorms. ... An outflow boundary is a storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature. ... The curl phase soon after an intense microburst impacted the surface Downburst damages in a straight line. ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ... A roll cloud is a low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front). ... This article is about the meteorological phenomenon. ... In meteorology, an anticyclone is a weather phenomenon associated with atmospheric high pressure. ... Dust Devil Image copyleft: Image taken by me, released under GFDL Pollinator 05:53, Sep 19, 2004 (UTC) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Dust Devil Image copyleft: Image taken by me, released under GFDL Pollinator 05:53, Sep 19, 2004 (UTC) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Johnsonville is a city located in Florence County, South Carolina. ... A dust devil in the Mojave Desert. ... For the Marvel Comics character, see Windshear (comics). ... In general terms, the climate of a locale or region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life. ... A winter waterspout seen over Lake Ontario from Whitby Ontario, January 26, 1994 A winter waterspout, also known as a snow devil or a snowspout, is an extremely rare meteorological phenomenon in which a vortex resembling that of a waterspout forms under the base of a snow squall. ... For other uses, see Wildfire (disambiguation). ... A fire whirl with flames in the vortex. ... Pyrocumulus, or fire cumulus, is a dense cumuliform cloud usually found at an altitude of 1500 m. ... This article is about rotation as a movement of a physical body. ... An Updraft or Downdraft is refers to the vertical movement of air as a weather related phenomenom. ... For other uses, see Steam (disambiguation). ... This article does not cite any references or sources. ... A power station (also power plant) is a facility for the generation of electric power. ... Chimney stacks on a Newcastle upon Tyne building A chimney is a system for venting hot gases and smoke from a stove, furnace or fireplace to the outside atmosphere. ... Green Dragon Spring at Norris Geyser A hot spring is a place where warm or hot groundwater issues from the ground on a regular basis for at least a predictable part of the year, and is significantly above the ambient ground temperature (which is usually around 55~57°F or... A dune in the Egyptian desert In geography, a desert is a landscape form or region that receives little precipitation. ... A funnel cloud. ...

Characteristics

A wedge tornado, nearly a mile wide. This tornado hit Binger, Oklahoma.
A wedge tornado, nearly a mile wide. This tornado hit Binger, Oklahoma.
A rope tornado in its dissipating stage.
A rope tornado in its dissipating stage.

Image File history File links Binger_Oklahoma_Tornado. ... Image File history File links Binger_Oklahoma_Tornado. ... Binger is a town located in Caddo County, Oklahoma. ... Image File history File links Download high resolution version (700x911, 57 KB) Summary A roping tornado, in the last stages of its life. ... Image File history File links Download high resolution version (700x911, 57 KB) Summary A roping tornado, in the last stages of its life. ...

Shape

Most tornadoes take on the appearance of a narrow funnel, a few hundred yards (a few hundred meters) across, with a small cloud of debris near the ground. However, tornadoes can appear in many shapes and sizes. A typical kitchen funnel. ... For other uses, see Cloud (disambiguation). ... Debris (French, pronounced (IPA) dibri) is a word used to describe the remains of something that has been otherwise destroyed. ...


Small, relatively weak landspouts may only be visible as a small swirl of dust on the ground. While the condensation funnel may not extend all the way to the ground, if associated surface winds are greater than 40 mph (64 km/h), the circulation is considered a tornado.[15] A tornado with a nearly cylindrical profile and relative low height is sometimes referred to as a stovepipe tornado. Large single-vortex tornadoes can look like large wedges stuck into the ground, and so are known as wedge tornadoes or wedges. The stovepipe classification is also used for this type of tornado, if it otherwise fits that profile. A wedge can be so wide that it appears to be a block of dark clouds, wider than the distance from the cloud base to the ground. Even experienced storm observers may not be able to tell the difference between a low-hanging cloud and a wedge tornado from a distance.[20] A landspout is a tornado not associated with the mesocyclone of a thunderstorm. ... For other uses, see Wedge (disambiguation). ...


Tornadoes in the dissipating stage can resemble narrow tubes or ropes, and often curl or twist into complex shapes. These tornadoes are said to be roping out, or becoming a rope tornado. Multiple-vortex tornadoes can appear as a family of swirls circling a common center, or may be completely obscured by condensation, dust, and debris, appearing to be a single funnel.[21]


In addition to these appearances, tornadoes may be obscured completely by rain or dust. These tornadoes are especially dangerous, as even experienced meteorologists might not spot them.[17]


Size

In the United States, on average tornadoes are around 500 feet (150 m) across, and stay on the ground for 5 miles (8 km).[17] Yet, there is an extremely wide range of tornado sizes, even for typical tornadoes. Weak tornadoes, or strong but dissipating tornadoes, can be exceedingly narrow, sometimes only a few feet across. A tornado was once reported to have a damage path only 7 feet (2 m) long.[17] On the other end of the spectrum, wedge tornadoes can have a damage path a mile (1.6 km) wide or more. A tornado that affected Hallam, Nebraska on May 22, 2004 was at one point 2.5 miles (4 km) wide at the ground.[2] is the 142nd day of the year (143rd in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...


In terms of path length, the Tri-State Tornado, which affected parts of Missouri, Illinois, and Indiana on March 18, 1925, was officially on the ground continuously for 219 miles (352 km). Many tornadoes which appear to have path lengths of 100 miles (160 km) or longer are actually a family of tornadoes which have formed in quick succession; however, there is no substantial evidence that this occurred in the case of the Tri-State Tornado.[8] In fact, modern reanalysis of the path suggests that the tornado began 15 miles (24 km) further west than previously thought.[22] 1Time from first tornado to last tornado 2Most severe tornado damage; see Fujita Scale The Great Tri-State Tornado of Wednesday, March 18, 1925, crossed from southeastern Missouri, through southern Illinois, then into southwestern Indiana, and was the deadliest tornado in U.S. history. ... This article is about the U.S. state. ... Official language(s) English[1] Capital Springfield Largest city Chicago Largest metro area Chicago Metropolitan Area Area  Ranked 25th  - Total 57,918 sq mi (140,998 km²)  - Width 210 miles (340 km)  - Length 390 miles (629 km)  - % water 4. ... For other uses, see Indiana (disambiguation). ... is the 77th day of the year (78th in leap years) in the Gregorian calendar. ... Year 1925 (MCMXXV) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar. ...


Appearance

Tornadoes can have a wide range of colors, depending on the environment in which they form. Those which form in a dry environment can be nearly invisible, marked only by swirling debris at the base of the funnel. Condensation funnels which pick up little or no debris can be gray to white. While travelling over a body of water as a waterspout, they can turn very white or even blue. Funnels which move slowly, ingesting a lot of debris and dirt, are usually darker, taking on the color of debris. Tornadoes in the Great Plains can turn red because of the reddish tint of the soil, and tornadoes in mountainous areas can travel over snow-covered ground, turning brilliantly white.[17] For other uses, see Great Plains (disambiguation). ...

Photographs of the Waurika, Oklahoma tornado of May 30, 1976, taken at nearly the same time by two photographers. In the top picture, the tornado is front-lit, with the sun behind the east-facing camera, so the funnel appears nearly white. In the lower image, where the camera is facing the opposite direction, the tornado is back-lit, with the sun behind the clouds.
Photographs of the Waurika, Oklahoma tornado of May 30, 1976, taken at nearly the same time by two photographers. In the top picture, the tornado is front-lit, with the sun behind the east-facing camera, so the funnel appears nearly white. In the lower image, where the camera is facing the opposite direction, the tornado is back-lit, with the sun behind the clouds.[23]

Lighting conditions are a major factor in the appearance of a tornado. A tornado which is "back-lit" (viewed with the sun behind it) appears very dark. The same tornado, viewed with the sun at the observer's back, may appear gray or brilliant white. Tornadoes which occur near the time of sunset can be many different colors, appearing in hues of yellow, orange, and pink.[24][12] Image File history File linksMetadata Download high resolution version (498x636, 30 KB)Montage of Waurika_Oklahoma_Tornado_Front-Lit. ... Image File history File linksMetadata Download high resolution version (498x636, 30 KB)Montage of Waurika_Oklahoma_Tornado_Front-Lit. ... Waurika is a city located in Jefferson County, Oklahoma. ... is the 150th day of the year (151st in leap years) in the Gregorian calendar. ... Year 1976 Pick up sticks(MCMLXXVI) was a leap year starting on Thursday (link will display full calendar) of the Gregorian calendar. ... For other uses, see Camera (disambiguation). ... Martha Byrne from As the World Turns, exhibiting the effects of back lighting on ones hair. ...


Dust kicked up by the winds of the parent thunderstorm, heavy rain and hail, and the darkness of night are all factors which can reduce the visibility of tornadoes. Tornadoes occurring in these conditions are especially dangerous, since only weather radar observations, or possibly the sound of an approaching tornado, serve as any warning to those in the storm's path. Fortunately most significant tornadoes form under the storm's rain-free base, or the area under the thunderstorm's updraft, where there is little or no rain. In addition, most tornadoes occur in the late afternoon, when the bright sun can penetrate even the thickest clouds.[8] Also, night-time tornadoes are often illuminated by frequent lightning. Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ...


There is mounting evidence, including Doppler On Wheels mobile radar images and eyewitness accounts, that most tornadoes have a clear, calm center with extremely low pressure, akin to the eye of tropical cyclones. This area would be clear (possibly full of dust), have relatively light winds, and be very dark, since the light would be blocked by swirling debris on the outside of the tornado. Lightning is said to be the source of illumination for those who claim to have seen the interior of a tornado.[25][26][27] A Doppler On Wheels unit observing a tornado near Attica, Kansas. ... Eye of the storm redirects here. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ...


Rotation

Tornadoes normally rotate cyclonically in direction (counterclockwise in the northern hemisphere, clockwise in the southern). While large-scale storms always rotate cyclonically due to the Coriolis effect, thunderstorms and tornadoes are so small that the direct influence of Coriolis effect is inconsequential, as indicated by their large Rossby numbers. Supercells and tornadoes rotate cyclonically in numerical simulations even when the Coriolis effect is neglected.[28][29] Low-level mesocyclones and tornadoes owe their rotation to complex processes within the supercell and ambient environment.[30] This article is about the meteorological phenomenon. ... Northern hemisphere highlighted in yellow. ... southern hemisphere highlighted in yellow (Antarctica not depicted). ... In the inertial frame of reference (upper part of the picture), the black object moves in a straight line. ... The Rossby number, named for Carl-Gustav Arvid Rossby, is a dimensionless number used in describing fluid flow, usually in geophysical phenomena in the oceans and atmosphere. ... It has been suggested that this article or section be merged into Supercell. ...


Approximately 1% of tornadoes rotate in an anticyclonic direction. Typically, only landspouts and gustnados rotate anticyclonically, and usually only those which form on the anticyclonic shear side of the descending rear flank downdraft in a cyclonic supercell.[31] However, on rare occasions, anticyclonic tornadoes form in association with the mesoanticyclone of an anticyclonic supercell, in the same manner as the typical cyclonic tornado, or as a companion tornado—either as a satellite tornado or associated with anticyclonic eddies within a supercell.[32] A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ... An anticyclonic tornado is a tornado which rotates in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. ...


Sound and seismology

Tornadoes emit widely on the acoustics spectrum and the sounds are cased by multiple mechanisms. Various sounds of tornadoes have been reported throughout time, mostly related to familiar sounds for the witness and generally some variation of a whooshing roar. Popularly reported sounds include a freight train, rushing rapids or waterfall, a jet engine from close proximity, or combinations of these. Many tornadoes are not audible from much distance; the nature and propagation distance of the audible sound depends on atmospheric conditions and topography. Acoustics is the branch of physics concerned with the study of sound (mechanical waves in gases, liquids, and solids). ... An audio frequency (abbreviation: AF) is any frequency from about 20 hertz to about 20 kilohertz, which is the approximate range of sound frequencies that is audible to humans. ... For other uses, see Train (disambiguation). ... For other uses, see Waterfall (disambiguation). ... A Pratt and Whitney turbofan engine for the F-15 Eagle is tested at Robins Air Force Base, Georgia, USA. The tunnel behind the engine muffles noise and allows exhaust to escape. ...


The winds of the tornado vortex and of constituent turbulent eddies, as well as airflow interaction with the surface and debris, contribute to the sounds. Funnel clouds also produce sounds. Funnel clouds and small tornadoes are reported as whistling, whining, humming, or the buzzing of innumerable bees or electricity, or more or less harmonic, whereas many tornadoes are reported as a continuous, deep rumbling, or an irregular sound of “noise”.[33] Turbulent flow around an obstacle; the flow further away is laminar Laminar and turbulent water flow over the hull of a submarine Turbulence creating a vortex on an airplane wing In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by low-momentum diffusion, high momentum convection, and... In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle. ... For other uses, see Western honey bee and Bee (disambiguation). ...


Since many tornadoes are audible only in very close proximity, sound is not reliable warning of a tornado. And, any strong, damaging wind, even a severe hail volley or continuous thunder in a thunderstorm may produce a roaring sound.[34]

An illustration of generation of infrasound in tornadoes by the Earth System Research Laboratory's Infrasound Program.
An illustration of generation of infrasound in tornadoes by the Earth System Research Laboratory's Infrasound Program.

Tornadoes also produce identifiable inaudible infrasonic signatures.[35] Unlike audible signatures, tornadic signatures have been isolated; due to the long distance propagation of low-frequency sound, efforts are ongoing to develop tornado prediction and detection devices with additional value in understanding tornado morphology, dynamics, and creation.[36] Tornadoes also produce a detectable seismic signature, and research continues on isolating it and understanding the process.[37] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The Earth System Research Laboratory (ESRL) is a laboratory in National Oceanic and Atmospheric Administration (NOAA)/Office of Oceanic and Atmospheric Research (OAR). ... Infrasound is sound with a frequency too low to be detected by the human ear (less than approximately 20 hertz). ... Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the movement of waves through the Earth. ...


Electromagnetic, lightning, and other effects

Tornadoes emit on the electromagnetic spectrum, for example, with sferics and E-field effects detected.[36][38] The effects vary, mostly with little observed consistency. Although some radiations are marked as N for no in the diagram, some waves do in fact penetrate the atmosphere, although extremely minimally compared to the other radiations The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. ... A frequency vs. ... In physics, an electric field or E-field is an effect produced by an electric charge that exerts a force on charged objects in its vicinity. ...


Correlations with patterns of lightning activity have also been observed, but little in way of consistent correlations have been advanced. Tornadic storms do not contain more lightning than other storms, and some tornadic cells never contain lightning. More often than not, overall cloud-to-ground (CG) lightning activity decreases as a tornado reaches the surface and returns to the baseline level when the tornado lifts. In many cases, very intense tornadoes and thunderstorms exhibit an increased and anomalous dominance in positive polarity CG discharges.[39] Electromagnetics and lightning have little to nothing to do directly with what drives tornadoes (tornadoes are basically a thermodynamic phenomenon), though there are likely connections with the storm and environment affecting both phenomena. Not to be confused with lighting. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... Thermodynamics (Greek: thermos = heat and dynamic = change) is the physics of energy, heat, work, entropy and the spontaneity of processes. ...


Luminosity has been reported in the past, and is probably due to misidentification of external light sources such as lightning, city lights, and power flashes from broken lines, as internal sources are now uncommonly reported and are not known to ever been recorded. This article does not cite any references or sources. ...


In addition to winds, tornadoes also exhibit changes in atmospheric variables such as temperature, moisture, and pressure. For example, on June 24, 2003 near Manchester, South Dakota, a probe measured a 100 mbar (hPa) (2.95 inHg) pressure deficit. The pressure dropped gradually as the vortex approached then dropped extremely rapidly to 850 mbar (hPa) (25.10 inHg) in the core of the violent tornado before rising rapidly as the vortex moved away, resulting in a V-shape pressure trace. Temperature tends to decrease and moisture content to increase in the immediate vicinity of a tornado.[40] For other uses, see Temperature (disambiguation). ... Dew on a spider web Moldy bread Moisture generally refers to the presence of water, often in trace amounts. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ... is the 175th day of the year (176th in leap years) in the Gregorian calendar. ... Year 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... Manchester, South Dakota was a small town located in South Dakota. ... The bar (symbol bar), decibar (symbol dbar) and the millibar (symbol mbar, also mb) are units of pressure. ... For other uses, see Pascal. ... Pressure is the application of force to a surface, and the concentration of that force in a given area. ... The bar (symbol bar), decibar (symbol dbar) and the millibar (symbol mbar, also mb) are units of pressure. ... For other uses, see Pascal. ... Pressure is the application of force to a surface, and the concentration of that force in a given area. ...


Life cycle

A sequence of images showing the birth of a tornado. First, the rotating cloud base lowers. This lowering becomes a funnel, which continues descending while winds build near the surface, kicking up dust and other debris. Finally, the visible funnel extends to the ground, and the tornado begins causing major damage. This tornado, near Dimmitt, Texas, was one of the best-observed violent tornadoes in history.
A sequence of images showing the birth of a tornado. First, the rotating cloud base lowers. This lowering becomes a funnel, which continues descending while winds build near the surface, kicking up dust and other debris. Finally, the visible funnel extends to the ground, and the tornado begins causing major damage. This tornado, near Dimmitt, Texas, was one of the best-observed violent tornadoes in history.
Further information: Tornadogenesis

Image File history File links Download high resolution version (700x1389, 75 KB) Summary This sequence of three photographs was taken by a member of the VORTEX project outside of Dimmit, TX on June 2, 1995. ... Image File history File links Download high resolution version (700x1389, 75 KB) Summary This sequence of three photographs was taken by a member of the VORTEX project outside of Dimmit, TX on June 2, 1995. ... Dimmitt is a city located in Castro County, Texas. ... A sequence of images showing the birth of a supercellular tornado. ...

Supercell relationship

See also: Supercell

Tornadoes often develop from a class of thunderstorms known as supercells. Supercells contain mesocyclones, an area of organized rotation a few miles up in the atmosphere, usually 1–6 miles (2–10 km) across. Most intense tornadoes (EF3 to EF5 on the Enhanced Fujita Scale) develop from supercells. In addition to tornadoes, very heavy rain, frequent lightning, strong wind gusts, and hail are common in such storms. Satellite view of a supercell A supercell is a severe thunderstorm with a deep rotating updraft (a mesocyclone) [1]. Supercell thunderstorms are the largest, most severe class of single-cell thunderstorms. ... Satellite view of a supercell A supercell is a severe thunderstorm with a deep rotating updraft (a mesocyclone) [1]. Supercell thunderstorms are the largest, most severe class of single-cell thunderstorms. ... It has been suggested that this article or section be merged into Supercell. ... The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States estimated via the damage they cause. ...


Most tornadoes from supercells follow a recognizable life cycle.[15] That begins when increasing rainfall drags with it an area of quickly descending air known as the rear flank downdraft (RFD). This downdraft accelerates as it approaches the ground, and drags the supercell's rotating mesocyclone towards the ground with it. A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ...


Formation

As the mesocyclone approaches the ground, a visible condensation funnel appears to descend from the base of the storm, often from a rotating wall cloud. As the funnel descends, the rear flank downdraft, also known as RFD, also reaches the ground, creating a gust front that can cause damage a good distance from the tornado. Usually, the funnel cloud becomes a tornado within minutes of the RFD reaching the ground. A wall cloud with tail cloud A wall cloud is a cloud formation. ...


Maturity

Initially, the tornado has a good source of warm, moist inflow to power it, so it grows until it reaches the mature stage. This can last anywhere from a few minutes to more than an hour, and during that time a tornado often causes the most damage, and in rare cases can be more than one mile (1.6 km) across. Meanwhile, the RFD, now an area of cool surface winds, begins to wrap around the tornado, cutting off the inflow of warm air which feeds the tornado.


Demise

As the RFD completely wraps around and chokes off the tornado's air supply, the vortex begins to weaken, and become thin and rope-like. This is the dissipating stage; often lasting no more than a few minutes, after which the tornado fizzles. During this stage the shape of the tornado becomes highly influenced by the winds of the parent storm, and can be blown into fantastic patterns.[23][24][8]


As the tornado enters the dissipating stage, its associated mesocyclone often weakens as well, as the rear flank downdraft cuts off the inflow powering it. In particularly intense supercells tornadoes can develop cyclically. As the first mesocyclone and associated tornado dissipate, the storm's inflow may be concentrated into a new area closer to the center of the storm. If a new mesocyclone develops, the cycle may start again, producing one or more new tornadoes. Occasionally, the old (occluded) mesocyclone and the new mesocyclone produce a tornado at the same time.


Though this is a widely-accepted theory for how most tornadoes form, live, and die, it does not explain the formation of smaller tornadoes, such as landspouts, long-lived tornadoes, or tornadoes with multiple vortices. These each have different mechanisms which influence their development—however, most tornadoes follow a pattern similar to this one.[41]

Intensity and damage

An example of EF1 damage. Here, the roof has been substantially damaged, and the garage door blown outwards, but the walls and supporting structures are still intact.
An example of EF1 damage. Here, the roof has been substantially damaged, and the garage door blown outwards, but the walls and supporting structures are still intact.

The Fujita scale and the Enhanced Fujita Scale rate tornadoes by damage caused. The Enhanced Fujita Scale was an upgrade to the older Fujita scale, with engineered (by expert elicitation) wind estimates and better damage descriptions, but was designed so that a tornado rated on the Fujita scale would receive the same numerical rating. An EF0 tornado will likely damage trees but not substantial structures, whereas an EF5 tornado can rip buildings off their foundations leaving them bare and even deform large skyscrapers. The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. Doppler radar data, photogrammetry, and ground swirl patterns (cycloidal marks) may also be analyzed to determine intensity and award a rating. Image File history File links EF1_tornado_damage_example. ... Image File history File links EF1_tornado_damage_example. ... The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States estimated via the damage they cause. ... A garage door is a large door on a garage or carport that can either be opened manually or by a garage door opener. ... One of the earliest photographs of a tornado. ... F-scale redirects here. ... The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States estimated via the damage they cause. ... In science, engineering, and research, expert elicitation is the synthesis of opinions of experts of a subject where there is uncertainty due to insufficient data, when such data is unattainable because of physical constraints or lack of resources. ... For other uses, see Skyscraper (disambiguation). ... The TORRO tornado intensity scale (or T-Scale) is a scale measuring tornado intensity between T0 and T10. ... Pulse-Doppler is a radar system capable of not only detecting target location (bearing, range, and altitude), but also measuring its radial velocity (range-rate). ... Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... Photogrammetry is a remote sensing technology in which geometric properties about objects are determined from photographic images. ...


Tornadoes vary in intensity regardless of shape, size, and location, though strong tornadoes are typically larger than weak tornadoes. The association with track length and duration also varies, although longer track tornadoes tend to be stronger.[42] In the case of violent tornadoes, only a small portion of the path is of violent intensity, most of the higher intensity from subvortices.[8] A multiple vortex tornado is a tornado that contains several vortices rotating around and inside of and part of the main vortex. ...


In the United States, 80% of tornadoes are EF0 and EF1 (T0 through T3) tornadoes. The rate of occurrence drops off quickly with increasing strength—less than 1% are violent tornadoes, stronger than EF4, T8.[43]


Outside the United States, areas in south-central Asia, and perhaps portions of southeastern South America and southern Africa, violent tornadoes are extremely rare. This is apparently mostly due to the lesser number of tornadoes overall, as research shows that tornado intensity distributions are fairly similar worldwide. A few significant tornadoes occur annually in Europe, Asia, southern Africa, and southeastern South America, respectively.[44]

Climatology

Main article: Tornado climatology
Areas worldwide where tornadoes are most likely, indicated by orange shading.
Areas worldwide where tornadoes are most likely, indicated by orange shading.
Intense tornado activity in the United States. The darker-colored areas denote the area commonly referred to as Tornado Alley.

The United States has the most tornadoes of any country, about four times more than estimated in all of Europe, not including waterspouts.[45] This is mostly due to the unique geography of the continent. North America is a relatively large continent that extends from the tropical south into arctic areas, and has no major east-west mountain range to block air flow between these two areas. In the middle latitudes, where most tornadoes of the world occur, the Rocky Mountains block moisture and atmospheric flow, allowing drier air at mid-levels of the troposphere, and causing cyclogenesis downstream to the east of the mountains. The desert Southwest also feeds drier air and the dry line, while the Gulf of Mexico fuels abundant low-level moisture. This unique topography allows for many collisions of warm and cold air, the conditions that breed strong, long-lived storms many times a year. A large portion of these tornadoes form in an area of the central United States known as Tornado Alley.[4] This area extends into Canada, particularly Ontario and the Prairie Provinces. Strong tornadoes also occasionally occur in northern Mexico. Areas worldwide which experience the highest chance of seeing tornadoes, indicated by orange shading. ... Image File history File linksMetadata Globdisttornado. ... Image File history File linksMetadata Globdisttornado. ... Image File history File links Tornado_Alley. ... Image File history File links Tornado_Alley. ... An outline of Significant Tornado Alley in the United States, where the highest percentage of violent tornadoes occur Tornado Alley is a colloquial term most often used in reference to the area of the United States in which tornadoes are most frequent. ... North American redirects here. ... A noontime scene from the Philippines on a day when the Sun is almost directly overhead. ... The red line indicates the 10°C isotherm in July, sometimes used to define the Arctic region border Artificially coloured topographical map of the Arctic region For the ship, see SS Arctic. ... The middle latitudes are the areas between 30 and 60 degrees north latitude and 30 and 60 degrees south, or, roughly, the earths temperate zones between the tropics and the Arctic and Antarctic. ... For individual mountains named Rocky Mountain, see Rocky Mountain (disambiguation). ... Atmosphere diagram showing the mesosphere and other layers. ... Cyclogenesis is the development or strengthening of cyclonic circulation in the atmosphere. ... A dry line, dew point line, or Marfa front[1] is a boundary separating moist and dry air masses, and an important factor in severe weather frequency in the Great Plains of North America. ... Gulf of Mexico in 3D perspective. ... The Central United States is a bridge region between the Eastern United States and Western United States. ... An outline of Significant Tornado Alley in the United States, where the highest percentage of violent tornadoes occur Tornado Alley is a colloquial term most often used in reference to the area of the United States in which tornadoes are most frequent. ... Motto: Ut Incepit Fidelis Sic Permanet (Latin: Loyal she began, loyal she remains) Capital Toronto Largest city Toronto Official languages English (de facto) Government Lieutenant-Governor David C. Onley Premier Dalton McGuinty (Liberal) Federal representation in Canadian Parliament House seats 107 Senate seats 24 Confederation July 1, 1867 (1st) Area... The Canadian prairies is a vast area of flat sedimentary land that stretches from Ontario and the Canadian Shield to the Canadian Rockies covering much of the provinces of Manitoba, Saskatchewan, and Alberta - the Prairie Provinces. ...


The United States averages about 1,200 tornadoes per year. The Netherlands has the highest average number of recorded tornadoes per area of any country (more than 20, or 0.0013 per sq mi (0.00048 per km²), annually), followed by the UK (around 33, or 0.00035 per sq mi (0.00013 per km²), per year), but most are small and cause minor damage. In absolute number of events, ignoring area, the UK experiences more tornadoes than any other European country, excluding waterspouts.[45]


Bangladesh and surrounding areas of eastern India suffer from tornadoes of equal severity to those in the US, and occurring more frequently than anywhere else in the world, but such events are under-reported due to the scarcity of media coverage in third-world countries. Tornados kill about 179 people per year in Bangladesh, many more than in the US. This is due to high population density, poor quality of construction, lack of tornado safety knowledge, and other factors.[46] Other areas of the world that have frequent tornadoes include South Africa, parts of Argentina, Paraguay, and southern Brazil, as well as portions of Europe, Australia and New Zealand, and far eastern Asia.[5] For other uses, see Europe (disambiguation). ... For other uses, see Asia (disambiguation). ...


Tornadoes are most common in spring and least common in winter.[8] Since autumn and spring are transitional periods (warm to cool and vice versa) there are more chances of cooler air meeting with warmer air, resulting in thunderstorms. Tornadoes can also be caused by landfalling tropical cyclones, which tend to occur in the late summer and autumn. But favorable conditions can occur at any time of the year. Hurricane Charley making landfall on August 13, 2004 at its peak intensity. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ...


Tornado occurrence is highly dependent on the time of day, because of solar heating.[47] Worldwide, most tornadoes occur in the late afternoon, between 3 and 7 pm local time, with a peak near 5 pm.[48][49][50][51][52] However, destructive tornadoes can occur at any time of day. The Gainesville Tornado of 1936, one of the deadliest tornadoes in history, occurred at 8:30 am local time.[8] Solar irradiance spectrum at top of atmosphere. ... 1Time from first tornado to last tornado 2Maximum windspeed of most powerful tornado The Tupelo-Gainesville Outbreak was the outbreak of tornadoes that included the 4th and 5th deadliest tornadoes in U.S. history. ...


Associations to climate and climate change

Associations to various climate and environmental trends exist. For example, an increase in the sea surface temperature of source region (e.g. Gulf of Mexico and Mediterranean Sea) increases moisture content, potentially fueling an increase in severe weather and tornado activity, particularly in the cool season.[53] Annual mean sea surface temperature for the World Ocean. ... Mediterranean redirects here. ...


Although insufficient support exists to make conclusions, evidence does suggest that the Southern Oscillation is weakly correlated with some changes in tornado activity; which vary by season and region as well as whether the ENSO phase is that of El Niño or La Niña.[54] The Southern Oscillation refers to an oscillation in air pressure between the southeastern and southwestern Pacific waters. ... Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 ENSO (El Niño-Southern Oscillation) is a global coupled ocean-atmosphere phenomenon. ... Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. ... La Niña is a coupled ocean-atmosphere phenomenon similar to El Niño. ...


Climatic shifts affect tornadoes via teleconnections in shifting the jet stream and the larger weather patterns. The climate-tornado link is confounded by the forces affecting larger patterns and by the local, nuanced nature of tornadoes. Although it is reasonable that the climate change phenomenon of global warming may affect tornado activity, any such effect is not yet identifiable due to the complexity, local nature of the storms, and database quality issues. Any effect would vary by region.[55] Variations in CO2, temperature and dust from the Vostok ice core over the last 450,000 years For current global climate change, see Global warming. ... Global warming refers to the increase in the average temperature of the Earths near-surface air and oceans in recent decades and its projected continuation. ...


Prediction

Probabilistic maps issued by the Storm Prediction Center during the heart of the April 6-8, 2006 Tornado Outbreak. The top map indicates the risk of general severe weather (including large hail, damaging winds, and tornadoes), while the bottom map specifically shows the percent risk of a tornado forming within 25 miles (40 km) of any point within the enclosed area. The hashed area on the bottom map indicates a 10% or greater risk of an F2 or stronger tornado forming within 25 miles (40 km) of a point.
Probabilistic maps issued by the Storm Prediction Center during the heart of the April 6-8, 2006 Tornado Outbreak. The top map indicates the risk of general severe weather (including large hail, damaging winds, and tornadoes), while the bottom map specifically shows the percent risk of a tornado forming within 25 miles (40 km) of any point within the enclosed area. The hashed area on the bottom map indicates a 10% or greater risk of an F2 or stronger tornado forming within 25 miles (40 km) of a point.

Weather forecasting is handled regionally by many national and international agencies. For the most part, they are also in charge of the prediction of conditions conducive to tornado development. Image File history File links Download high-resolution version (582x818, 42 KB) Summary Probabilistic maps issued by the Storm Prediction Center during the heart of the April 6-8, 2006 Tornado Outbreak. ... Image File history File links Download high-resolution version (582x818, 42 KB) Summary Probabilistic maps issued by the Storm Prediction Center during the heart of the April 6-8, 2006 Tornado Outbreak. ... Probability is the likelihood that something is the case or will happen. ... The Storm Prediction Center, located in Norman, Oklahoma, is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service, which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. government. ... 1Time from first tornado to last tornado 2Most severe tornado damage; see Fujita scale The April 6-8, 2006 Tornado Outbreak was a major tornado outbreak in the Central and parts of the Southern United States that began on April 6, 2006 in the Great Plains and continued until April... NOAA scientists observe severe weather using a mobile doppler radar and a helicopter (in the distance) Severe weather phenomena are weather conditions that are hazardous. ... This article is about the precipitation. ... F-scale redirects here. ... Modern weather predictions aid in timely evacuations and potentially save lives and property damage Human beings have attempted to predict the weather since time immemorial. ...


Australia

Severe thunderstorm warnings are provided to Australia by the Bureau of Meteorology. The country is in the middle of an upgrade to Doppler radar systems, with their first benchmark of installing six new radars reached in July 2006.[56] The Bureau of Meteorology is an Executive Agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. ... Pulse-Doppler is a radar system capable of not only detecting target location (bearing, range, and altitude), but also measuring its radial velocity (range-rate). ... Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ...


Europe

The European Union founded a project in 2002 called the European Severe Storms virtual Laboratory, or ESSL, which is meant to fully document tornado occurrence across the continent. The ESTOFEX (European Storm Forecast Experiment) arm of the project also issues one day forecasts for severe weather likelihood.[57] In Germany, Austria, and Switzerland, an organization known as TorDACH collects information regarding tornadoes, waterspouts, and downbursts from Germany, Austria, and Switzerland. A secondary goal is collect all severe weather information. This project is meant to fully document severe weather activity in these three countries.[58]


United Kingdom

In the United Kingdom, the Tornado and Storm Research Organisation (TORRO) makes experimental predictions. The Met Office provides official forecasts for the UK. The Tornado and Storm Research Organisation (TORRO) was founded by Dr Terence Meaden in 1974. ... The new building on the edge of Exeter The Met Office (originally an abbreviation for Meteorological Office, but now the official name in itself), which has its headquarters at Exeter in Devon, is the United Kingdoms national weather service. ...


United States

In the United States, generalized severe weather predictions are issued by the Storm Prediction Center, based in Norman, Oklahoma. For the next one, two, and three days, respectively, they will issue categorical and probabilistic forecasts of severe weather, including tornadoes. There is also a more general forecast issued for the four to eight day period. Just prior to the expected onset of an organized severe weather threat, SPC issues severe thunderstorm and tornado watches, in collaboration with local National Weather Service offices. Warnings are issued by local National Weather Service offices when a severe thunderstorm or tornado is occurring or imminent. The Storm Prediction Center, located in Norman, Oklahoma, is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service, which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. government. ... Norman, Oklahoma, is the county seat and largest city in Cleveland County in the U.S. state of Oklahoma, and is part of the Oklahoma City Metropolitan Statistical Area. ... The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... Insert non-formatted text here--24. ...


Other areas

In Japan, predictions and study of tornadoes in Japan are handled by the Japan Meteorological Agency. In Canada, weather forecasts and warnings, including tornadoes, are produced by the seven regional offices of the Meteorological Service of Canada, a division of Environment Canada. Japan Meteorological Agency (気象庁) is a government agency, which is a central place responsible for gathering and reporting weather data and forecasts in Japan. ... The Meteorological Service of Canada (MSC) is a Canadian government agency which provides meteorological information. ... Environment Canada is the department of the government of Canada with responsibility for coordinating environmental policies and programs as well as preserving and enhancing the natural environment and conservation of wildlife. ...


Detection

A Doppler radar image indicating the likely presence of a tornado over DeLand, Florida. Green colors indicate areas where the precipitation is moving towards the radar dish, while red areas are moving away. In this case the radar is in the bottom right corner of the image. Strong mesocyclones show up as adjacent areas of bright green and bright red, and usually indicate an imminent or occurring tornado. When these bright colors are one against the other on a radar display when in association with rotation, it is called a Tornado vortex signature.
A Doppler radar image indicating the likely presence of a tornado over DeLand, Florida. Green colors indicate areas where the precipitation is moving towards the radar dish, while red areas are moving away. In this case the radar is in the bottom right corner of the image. Strong mesocyclones show up as adjacent areas of bright green and bright red, and usually indicate an imminent or occurring tornado. When these bright colors are one against the other on a radar display when in association with rotation, it is called a Tornado vortex signature.

Rigorous attempts to warn of tornadoes began in the United States in the mid-20th century. Before the 1950s, the only method of detecting a tornado was by someone seeing it on the ground. Often, news of a tornado would reach a local weather office after the storm. Image File history File links Download high-resolution version (785x748, 756 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tornado 2007 Central Florida Tornado ... Image File history File links Download high-resolution version (785x748, 756 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tornado 2007 Central Florida Tornado ... Pulse-Doppler is a radar system capable of not only detecting target location (bearing, range, and altitude), but also measuring its radial velocity (range-rate). ... Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... 1Time from first tornado to last tornado 2Most severe tornado damage; see Enhanced Fujita Scale The 2007 Central Florida Tornadoes were a localized, but devastating, tornado event that took place in central Florida early on February 2, 2007. ... The Annual Dog Parade in DeLand Old Volusia County Courthouse in DeLand Manatees in Blue Spring State Park near DeLand DeLand is the county seat of Volusia County, Florida. ... It has been suggested that this article or section be merged into Supercell. ...


However, with the advent of weather radar, areas near a local office could get advance warning of severe weather. The first public tornado warnings were issued in 1950 and the first tornado watches and convective outlooks in 1952. In 1953 it was confirmed that hook echoes are associated with tornadoes. By recognizing these radar signatures, meteorologists could detect thunderstorms likely producing tornadoes from dozens of miles away.[59] Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... Tornado at beginning of life. ... A tornado watch is issued when weather conditions are favorable for the development of severe thunderstorms that are capable of producing tornados. ... The Storm Prediction Center, located in Norman, Oklahoma, is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service, which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. government. ... A classic hook echo. ...


Storm spotting

In the mid 1970s, the US National Weather Service (NWS) increased its efforts to train storm spotters to spot key features of storms which indicate severe hail, damaging winds, and tornadoes, as well as damage itself and flash flooding. The program was called Skywarn, and the spotters were local sheriff's deputies, state troopers, firefighters, ambulance drivers, amateur radio operators, civil defense (now emergency management) spotters, storm chasers, and ordinary citizens. When severe weather is anticipated, local weather service offices request that these spotters look out for severe weather, and report any tornadoes immediately, so that the office can issue a timely warning. A storm spotter is any individual who actively maintains a visual watch of the development and progression of specific weather events while actively relaying important information to the local weather agency in a timely manner. ... Lower Antelope Canyon was carved out of sandstone by flash floods A Flash Flood is a rapid flooding of geomorphic low-lying areas (washes), rivers and streams, caused by the intense rainfall associated with a thunderstorm, or multiple training thunderstorms. ... SKYWARN is a program of the United States National Weather Service (NWS). ... Look up Sheriff in Wiktionary, the free dictionary. ... State police are a type of sub-national territorial police force, particularly in Australia and the United States. ... This article is about the profession. ... The Star of Life, a global symbol for medical service EMTs loading an injured skier into an ambulance An Emergency Medical Technician (EMT) is an emergency responder trained to provide emergency medical services to the critically ill and injured. ... An amateur radio operator is an individual who, typically, uses equipment at an amateur radio station to engage in two-way personal communications with other similar individuals on radio frequencies assigned to the Amateur Radio Service. ... The old United States civil defense logo. ... // Emergency management (or disaster management) is the discipline dealing of with and avoiding risks. ... NSSL vehicles on Project Vortex. ...


Usually spotters are trained by the NWS on behalf of their respective organizations, and report to them. The organizations activate public warning systems such as sirens and the Emergency Alert System, and forward the report to the NWS.[60] There are more than 230,000 trained Skywarn weather spotters across the United States.[61] Thunderbolt 1000/1000T Civil Defense siren. ... The Emergency Alert System (EAS) is a national system in the U.S. put into place in 1994, superseding the Emergency Broadcast System (EBS) and is jointly coordinated by the Federal Communications Commission (FCC), Federal Emergency Managemant Agency (FEMA), and the National Weather Service (NWS). ...


In Canada, a similar network of volunteer weather watchers, called Canwarn, helps spot severe weather, with more than 1,000 volunteers.[62] In Europe, several nations are organizing spotter networks under the auspices of Skywarn Europe[63] and the Tornado and Storm Research Organisation (TORRO) has maintained a network of spotters in the United Kingdom since the 1970s. The Canwarn program is an organized severe weather spotting and reporting program organized and run by Environment Canada. ... The Tornado and Storm Research Organisation (TORRO) was founded by Terence Meaden in 1974. ...


Storm spotters are needed because radar systems such as NEXRAD do not detect a tornado; only indications of one. Radar may give a warning before there is any visual evidence of a tornado or imminent tornado, but ground truth from an observer can either verify the threat or determine that a tornado is not imminent. The spotter's ability to see what radar cannot is especially important as distance from the radar site increases, because the radar beam becomes progressively higher in altitude further away from the radar, chiefly due to curvature of Earth, and the beam also spreads out. Therefore, when far from a radar, only high in the storm is observed and the important areas are not sampled, and data resolution also suffers. Also, some meteorological situations leading to tornadogenesis are not readily detectable by radar and on occasion tornado development may occur more quickly than radar can complete a scan and send the batch of data. NEXRAD Radar at NSSL NEXRAD or Nexrad (Next-Generation Radar) is a network of 158 high-resolution Doppler radars operated by the National Weather Service, an agency of the National Oceanic and Atmospheric Administration (NOAA), in the United States. ... In cartography, analysis of aerial photographs, satellite imagery and a range of other remote sensing techniques in which data are gathered at a distance, ground truth is information that is collected on location. In remote sensing, this is especially important in order to relate image data with real features and...


Visual evidence

A rotating wall cloud with rear flank downdraft clear slot evident to its left rear.
A rotating wall cloud with rear flank downdraft clear slot evident to its left rear.

Storm spotters are trained to discern whether a storm seen from a distance is a supercell. They typically look to its rear, the main region of updraft and inflow. Under the updraft is a rain-free base, and the next step of tornadogenesis is the formation of a rotating wall cloud. The vast majority of intense tornadoes occur with a wall cloud on the backside of a supercell.[43] Image File history File links Size of this preview: 800 × 514 pixelsFull resolution (1836 × 1180 pixel, file size: 1. ... Image File history File links Size of this preview: 800 × 514 pixelsFull resolution (1836 × 1180 pixel, file size: 1. ... A wall cloud with tail cloud A wall cloud is a cloud formation. ... A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ... Satellite view of a supercell A supercell is a severe thunderstorm with a deep rotating updraft (a mesocyclone) [1]. Supercell thunderstorms are the largest, most severe class of single-cell thunderstorms. ... An Updraft or Downdraft is refers to the vertical movement of air as a weather related phenomenom. ... A sequence of images showing the birth of a supercellular tornado. ... A wall cloud with tail cloud A wall cloud is a cloud formation. ...


Evidence of a supercell comes from the storm's shape and structure, and cloud tower features such as a hard and vigorous updraft tower, a persistent, large overshooting top, a hard anvil (especially when backsheared against strong upper level winds), and a corkscrew look or striations. Under the storm and closer to where most tornadoes are found, evidence of a supercell and likelihood of a tornado includes inflow bands (particularly when curved) such as a "beaver tail", and other clues such as strength of inflow, warmth and moistness of inflow air, how outflow- or inflow-dominant a storm appears, and how far is the front flank precipitation core from the wall cloud. Tornadogenesis is most likely at the interface of the updraft and rear flank downdraft, and requires a balance between the outflow and inflow.[15] Cumulonimbus (Cb) is a type of cloud that is tall, dense, and involved in thunderstorms and other intense weather. ... An overshooting top protruding above the anvil at the top of a thunderstorm An overshooting top is a domed structure shooting out of the anvil of a thunderstorm, sometimes into the stratosphere. ... For other uses, see Wind (disambiguation). ... Bodybuilding In bodybuilding, striations are the tiny grooves of muscle across major muscle groups characteristic of a well-developed body. ... A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ...


Only wall clouds that rotate spawn tornadoes, and usually precede the tornado by five to thirty minutes. Rotating wall clouds are the visual manifestation of a mesocyclone. Barring a low-level boundary, tornadogenesis is highly unlikely unless a rear flank downdraft occurs, which is usually visibly evidenced by evaporation of cloud adjacent to a corner of a wall cloud. A tornado often occurs as this happens or shortly after; first, a funnel cloud dips and in nearly all cases by the time it reaches halfway down, a surface swirl has already developed, signifying a tornado is on the ground before condensation connects the surface circulation to the storm. Tornadoes may also occur without wall clouds, under flanking lines, and on the leading edge. Spotters watch all areas of a storm, and the cloud base and surface.[64] It has been suggested that this article or section be merged into Supercell. ... A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ... For other uses, see Cloud (disambiguation). ... A funnel cloud. ... This article refers to meterology, for the airborne base of Captain Scarlet see Cloudbase. ...


Radar

Today, most developed countries have a network of weather radars, which remains the main method of detecting signatures likely associated with tornadoes. In the United States and a few other countries, Doppler radar stations are used. These devices measure the velocity and radial direction (towards or away from the radar) of the winds in a storm, and so can spot evidence of rotation in storms from more than a hundred miles (160 km) away. Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... Pulse-Doppler is a radar system capable of not only detecting target location (bearing, range, and altitude), but also measuring its radial velocity (range-rate). ... Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... This article is about positional information. ...


Also, most populated areas on Earth are now visible from the Geostationary Operational Environmental Satellites (GOES), which aid in the nowcasting of tornadic storms.[62] The Geostationary Operational Environmental Satellite (GOES) program is a key element in United States National Weather Service (NWS) operations. ... Modern weather predictions aid in timely evacuations and potentially save lives and property damage Human beings have attempted to predict the weather since time immemorial. ...

Extremes

Main article: Tornado records

The most extreme tornado in recorded history was the Tri-State Tornado which roared through parts of Missouri, Illinois, and Indiana on March 18, 1925. It was likely an F5, though tornadoes were not ranked on any scale in that era. It holds records for longest path length (219 miles, 352 km), longest duration (about 3.5 hours), and fastest forward speed for a significant tornado (73 mph, 117 km/h) anywhere on earth. In addition, it is the deadliest single tornado in United States history (695 dead).[8] It was also the second costliest tornado in history at the time, but has been surpassed by several others non-normalized. When costs are normalized for wealth and inflation, it still ranks third today.[65] This is a list of some tornado records. ... 1Time from first tornado to last tornado 2Most severe tornado damage; see Fujita Scale The Great Tri-State Tornado of Wednesday, March 18, 1925, crossed from southeastern Missouri, through southern Illinois, then into southwestern Indiana, and was the deadliest tornado in U.S. history. ... This article is about the U.S. state. ... Official language(s) English[1] Capital Springfield Largest city Chicago Largest metro area Chicago Metropolitan Area Area  Ranked 25th  - Total 57,918 sq mi (140,998 km²)  - Width 210 miles (340 km)  - Length 390 miles (629 km)  - % water 4. ... For other uses, see Indiana (disambiguation). ... is the 77th day of the year (78th in leap years) in the Gregorian calendar. ... Year 1925 (MCMXXV) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar. ...


The deadliest tornado in world history was the Daultipur-Salturia Tornado in Bangladesh on April 26, 1989, which killed approximately 1300 people.[46] The Daultipur-Salturia tornado which occurred in Manikganj District, Bangladesh on the 26 April 1989. ... is the 116th day of the year (117th in leap years) in the Gregorian calendar. ... Year 1989 (MCMLXXXIX) was a common year starting on Sunday (link displays 1989 Gregorian calendar). ...

A map of the tornado paths in the Super Outbreak.
A map of the tornado paths in the Super Outbreak.

The most extensive tornado outbreak on record, in almost every category, was the Super Outbreak, which affected a large area of the central United States and extreme southern Ontario in Canada on April 3 and April 4, 1974. Not only did this outbreak feature an incredible 148 tornadoes in only 18 hours, but an unprecedented number of them were violent; six were of F5 intensity, and twenty-four F4. This outbreak had a staggering sixteen tornadoes on the ground at the same time at the peak of the outbreak. More than 300 people, possibly as many as 330, were killed by tornadoes during this outbreak.[66] Image File history File links Download high resolution version (591x724, 199 KB)Tracks of tornadoes generated during the 1974 Super Outbreak. ... Image File history File links Download high resolution version (591x724, 199 KB)Tracks of tornadoes generated during the 1974 Super Outbreak. ... While there is no single agreed upon definition, generally more than six tornadoes in a day in the same region is considered a tornado outbreak. ... 1Time from first tornado to last tornado 2Most severe tornado damage; see Fujita Scale The Super Outbreak is the largest tornado outbreak on record. ... Motto: Ut Incepit Fidelis Sic Permanet (Latin: Loyal she began, loyal she remains) Capital Toronto Largest city Toronto Official languages English (de facto) Government Lieutenant-Governor David C. Onley Premier Dalton McGuinty (Liberal) Federal representation in Canadian Parliament House seats 107 Senate seats 24 Confederation July 1, 1867 (1st) Area... is the 93rd day of the year (94th in leap years) in the Gregorian calendar. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ... Year 1974 (MCMLXXIV) was a common year starting on Tuesday (link will display full calendar) of the 1974 Gregorian calendar. ...


While it is nearly impossible to directly measure the most violent tornado wind speeds (conventional anemometers would be destroyed by the intense winds), some tornadoes have been scanned by mobile Doppler radar units, which can provide a good estimate of the tornado's winds. The highest wind speed ever measured in a tornado, which is also the highest wind speed ever recorded on the planet, is 301 ± 20 mph (484 ± 32 km/h) in the F5 Moore, Oklahoma tornado. Though the reading was taken about 100 feet (30 m) above the ground, this is a testament to the power of the strongest tornadoes.[1] A hemispherical cup anemometer of the type invented in 2000 by John Thomas Romney Robinson An anemometer is a device for measuring the velocity or the pressure of the wind, and is one instrument used in a weather station. ... A Doppler On Wheels unit observing a tornado near Attica, Kansas. ... Moore is a rapidly growing suburb in Cleveland County, Oklahoma and is part of the Oklahoma City Metropolitan Area. ...


Storms which produce tornadoes can feature intense updrafts (sometimes exceeding 150 mph, 240 km/h). Debris from a tornado can be lofted into the parent storm and carried a very long distance. A tornado which affected Great Bend, Kansas in November, 1915 was an extreme case, where a "rain of debris" occurred 80 miles (130 km) from the town, a sack of flour was found 110 miles (177 km) away, and a cancelled check from the Great Bend bank was found in a field outside of Palmyra, Nebraska, 305 miles (491 km) to the northeast.[67] Great Bend is the largest city and county seat of Barton County, Kansas, United States. ... Palmyra is a village located in Otoe County, Nebraska. ...

Safety

Though tornadoes can strike in an instant, there are precautions and preventative measures that people can take to increase the chances of surviving a tornado. Authorities such as the Storm Prediction Center advise having a tornado plan. When a tornado warning is issued, going to a basement or an interior first-floor room of a sturdy building greatly increases chances of survival.[68] In tornado-prone areas, many buildings have storm cellars on the property. These underground refuges have saved thousands of lives.[69] The Storm Prediction Center, located in Norman, Oklahoma, is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service, which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. government. ... Categories: Stub ...


Some countries have meteorological agencies which distribute tornado forecasts and increase levels of alert of a possible tornado (such as tornado watches and warnings in the United States and Canada). Weather radios provide an alarm when a severe weather advisory is issued for the local area, though these are mainly available only in the United States. A tornado watch is issued when weather conditions are favorable for the development of severe thunderstorms that are capable of producing tornados. ... Tornado at beginning of life. ... Weatheradio is a special radio service available over much of North America that transmits weather warnings and forecasts 24 hours a day. ...


Unless the tornado is far away and highly visible, meteorologists advise that drivers park their vehicles far to the side of the road (so as not to block emergency traffic), and find a sturdy shelter. If no sturdy shelter is nearby, getting low in a ditch is the next best option. Highway overpasses are extremely bad shelter during tornadoes (see next section).[70]


Myths and misconceptions

Salt Lake City Tornado, August 11, 1999. This tornado disproved several myths, including the idea that tornadoes cannot occur in areas like Utah.
Salt Lake City Tornado, August 11, 1999. This tornado disproved several myths, including the idea that tornadoes cannot occur in areas like Utah.
Main article: Tornado myths

One of the most persistent myths associated with tornadoes is that opening windows will lessen the damage caused by the tornado. While there is a large drop in atmospheric pressure inside a strong tornado, it is unlikely that the pressure drop would be enough to cause the house to explode. Some research indicates that opening windows may actually increase the severity of the tornado's damage. Regardless of the validity of the explosion claim, time would be better spent seeking shelter before a tornado than opening windows. A violent tornado can destroy a house whether its windows are open or closed.[71][72] Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Avenues neighborhood damage The Salt Lake City Tornado was a very rare tornado that occurred in Salt Lake City, Utah on August 11, 1999, during an unusually strong summer monsoon season. ... is the 223rd day of the year (224th in leap years) in the Gregorian calendar. ... Events of 2008: (EMILY) Me Lesley and MIley are going to China! This article is about the year. ... This article is about the U.S. state. ... This article or section does not adequately cite its references or sources. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ...


Another commonly held belief is that highway overpasses provide adequate shelter from tornadoes. On the contrary, a highway overpass is a dangerous place during a tornado. In the 1999 Oklahoma tornado outbreak of May 3, 1999, three highway overpasses were directly struck by tornadoes, and at all three locations there was a fatality, along with many life-threatening injuries. The small area under the overpasses created a kind of wind tunnel, increasing the wind's speed, making the situation worse.[73] 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.[70] is the 123rd day of the year (124th in leap years) in the Gregorian calendar. ... Events of 2008: (EMILY) Me Lesley and MIley are going to China! This article is about the year. ... NASA wind tunnel with the model of a plane A wind tunnel is a research tool developed to assist with studying the effects of air moving over or around solid objects. ...


An old belief is that the southwest corner of a basement provides the most protection during a tornado. The safest place is the side or corner of an underground room opposite the tornado's direction of approach (usually the northeast corner), or the central-most room on the lowest floor. Taking shelter under a sturdy table, in a basement, or under a staircase increases chances of survival even more.[71][72]


Finally, there are areas which people believe to be protected from tornadoes, whether by a major river, a hill or mountain, or even protected by "spirits". Tornadoes have been known to cross major rivers, climb mountains,[74] and affect valleys. As a general rule, no area is "safe" from tornadoes, though some areas are more susceptible than others.[71][72][17] (See Tornado climatology). For other uses, see Spirit (disambiguation). ... Areas worldwide which experience the highest chance of seeing tornadoes, indicated by orange shading. ...

Continuing research

A Doppler On Wheels unit observing a tornado near Attica, Kansas.
A Doppler On Wheels unit observing a tornado near Attica, Kansas.

Meteorology is a relatively young science and the study of tornadoes even more so. Although studied for about 140 years and intensively for around 60 years, there are still aspects of tornadoes which remain a mystery.[75] Scientists do have a fairly good idea of the development of thunderstorms and mesocyclones, and the meteorological conditions conducive to their formation; however, the step from supercell (or other respective formative processes) to tornadogenesis and predicting tornadic vs. non-tornadic mesocyclones is not yet well understood and is the focus of much research. Image File history File links Tornado_with_DOW.jpg‎ File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tornado ... Image File history File links Tornado_with_DOW.jpg‎ File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tornado ... A Doppler On Wheels unit observing a tornado near Attica, Kansas. ... Attica is a city located in Harper County, Kansas. ... It has been suggested that this article or section be merged into Supercell. ... Satellite view of a supercell A supercell is a severe thunderstorm with a deep rotating updraft (a mesocyclone) [1]. Supercell thunderstorms are the largest, most severe class of single-cell thunderstorms. ... A sequence of images showing the birth of a supercellular tornado. ...


Also under study are the low-level mesocyclone and the stretching of low-level vorticity which tightens into a tornado, namely, what are the processes and what is the relationship of the environment and the convective storm. Intense tornadoes have been observed forming simultaneously with a mesocyclone aloft (rather than succeeding mesocyclogenesis) and some intense tornadoes have occurred without a mid-level mesocyclone. In particular, the role of downdrafts, particularly the rear-flank downdraft, and the role of baroclinic boundaries, are intense areas of study. Vorticity is a mathematical concept used in fluid dynamics. ... A downdraft is downward moving air, usually the direct result of air convection within the thunderstorm. ... A classic hook echo, indicating the presence of a rear flank downdraft (and in this case, a tornado). ... In fluid dynamics, the baroclinity (sometimes called baroclinicity) is a measure of the stratification in a fluid. ...


Reliably predicting tornado intensity and longevity remains a problem, as do details affecting characteristics of a tornado during its life cycle and tornadolysis. Other rich areas of research are tornadoes associated with mesovortices within linear thunderstorm structures and within tropical cyclones.[76]


Scientists still do not know the exact mechanisms by which most tornadoes form, and occasional tornadoes still strike without a tornado warning being issued, especially in under-developed countries. Analysis of observations including both stationary and mobile (surface and aerial) in-situ and remote sensing (passive and active) instruments generates new ideas and refines existing notions. Numerical modeling also provides new insights as observations and new discoveries are integrated into our physical understanding and then tested in computer simulations which validate new notions as well as produce entirely new theoretical findings, many of which are otherwise unattainable. Importantly, development of new observation technologies and installation of finer spatial and temporal resolution observation networks have aided increased understanding and better predictions. In situ is a Latin phrase meaning in the place. ... For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system. ... It has been suggested that simulation software be merged into this article or section. ...


Research programs, including field projects such as VORTEX, deployment of TOTO (the TOtable Tornado Observatory), Doppler On Wheels (DOW), and dozens of other programs, hope to solve many questions that still plague meteorologists.[36] Universities, government agencies such as the National Severe Storms Laboratory, private-sector meteorologists, and the National Center for Atmospheric Research are some of the organizations very active in research; with various sources of funding, both private and public, a chief entity being the National Science Foundation. Vortex created by the passage of an aircraft wing, revealed by coloured smoke A vortex (pl. ... TOTO The TOtable Tornado Observatory (nicknamed TOTO after the dog in the movie The Wizard of Oz was a large, instrumented metal barrel which scientists attempted to put in the path of a tornado during the 1980s. ... A Doppler On Wheels unit observing a tornado near Attica, Kansas. ... The National Severe Storms Laboratory (NSSL) is a weather research laboratory based in Norman, Oklahoma. ... NCAR, Boulder, Colorado National Center for Atmospheric Research (NCAR) is a U.S.-based institute whose stated mission is: NCARs flagship Mesa Laboratory is located in the outskirts of Boulder, Colorado, in a dramatic complex of buildings designed by architect I.M. Pei. ... The logo of the National Science Foundation The National Science Foundation (NSF) is an independent United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. ...


See also

Find more about tornado on Wikipedia's sister projects:
Dictionary definitions
Textbooks
Quotations
Source texts
Images and media
News stories
Learning resources
Weather Portal

Wikipedia does not have an article with this exact name. ... Image File history File links Wikibooks-logo. ... Image File history File links Wikiquote-logo. ... Image File history File links Wikisource-logo. ... Image File history File links Commons-logo. ... Image File history File links WikiNews-Logo. ... Image File history File links Wikiversity-logo-Snorky. ... Tornado damage to man-made structures is a result of the high wind velocity and windblown debris. ... This article is about the meteorological phenomenon. ... A derecho is a widespread and long-lived, violent convectively induced windstorm that is associated with a fast-moving band of severe thunderstorms usually taking the form of a bow echo. ... The curl phase soon after an intense microburst impacted the surface Downburst damages in a straight line. ... . ... // Tornado Events These are some notable tornadoes, tornado outbreaks, and tornado outbreak sequences that have occurred around the globe. ... This is a list of all official and possible F5 tornadoes ever recorded. ... // This article is a list of tornadoes that have impacted the central business district (downtown) of a large city. ... These are all tornadoes that have resulted in student deaths at schools in the United States from 1884 - 1990. ... NOAA scientists observe severe weather using a mobile doppler radar and a helicopter (in the distance) Severe weather phenomena are weather conditions that are hazardous. ... A skipping tornado is a vaguely defined term which refers to a tornado which has a discontinuous damage path. ... For the geological process, see Weathering or Erosion. ... Image File history File links Download high resolution version (1754x2646, 2231 KB) Rooster Weather Vane photographer: Arne Koehler File links The following pages link to this file: Weather vane ...

References

  1. ^ a b Doppler On Wheels. Center for Severe Weather Research (2006). Retrieved on 2006-12-29.
  2. ^ a b Hallam Nebraska Tornado. Omaha/Valley, NE Weather Forecast Office (2005-10-02). Retrieved on 2006-09-08.
  3. ^ a b c d e f Edwards, Roger (2006-04-04). The Online Tornado FAQ. Storm Prediction Center. Retrieved on 2006-09-08.
  4. ^ a b c Perkins, Sid (2002-05-11). Tornado Alley, USA. Science News 296–298. Retrieved on 2006-09-20.
  5. ^ a b Encyclopædia Britannica. Tornado: Global occurrence. Retrieved on 2007-03-21.
  6. ^ a b Glossary of Meteorology, Second Edition. American Meteorological Society (2000). Retrieved on 2006-11-17.
  7. ^ Branick, Michael (2006). A Comprehensive Glossary of Weather Terms for Storm Spotters. NOAA. Retrieved on 2007-02-27.
  8. ^ a b c d e f g h i Grazulis, Thomas P (1993 July). Significant Tornadoes 1680–1991. St. Johnsbury, VT: The Tornado Project of Environmental Films. ISBN 1-879362-03-1. 
  9. ^ Russell S. Schneider; Harold E. Brooks, and Joseph T. Schaefer (2004). Tornado Outbreak Day Sequences: Historic Events and Climatology (1875–2003) (PDF). Retrieved on 2007-03-20.
  10. ^ Harper, Douglas (November 2001). Online Etymology Dictionary. Retrieved on 2006-09-20.
  11. ^ (1993) Merriam Webster's Collegiate Dictionary, 10th Edition, Springfield, MA: Merriam-Webster, Incorporated. ISBN 0-87779-709-9. 
  12. ^ a b The Tornado Project's Terrific, Timeless and Sometimes Trivial Truths about Those Terrifying Twirling Twisters!. The Tornado Project (1999). Retrieved on 2007-03-21.
  13. ^ a b c Zittel, Dave (May 4, 2000). Tornado Chase 2000. USA Today. Retrieved on 2007-05-19.
  14. ^ Golden, Joseph. Waterspouts are tornadoes over water. USA Today. Retrieved on 2007-05-19.
  15. ^ a b c d Doswell, Moller, Anderson et al. (2005). Advanced Spotters' Field Guide (PDF). US Department of Commerce. Retrieved on 2006-09-20.
  16. ^ Gustnado. Glossary of Meteorology. American Meteorological Society. Retrieved on 2006-09-20.
  17. ^ a b c d e f Lyons, Walter A (1997). "Tornadoes", The Handy Weather Answer Book, 2nd Edition, Detroit, Michigan: Visible Ink press, pgs. 175–200. ISBN 0-7876-1034-8. 
  18. ^ Charles H. Jones; Charlie A. Liles (1999). Severe Weather Climatology for New Mexico. Retrieved on 2006-09-29.
  19. ^ Schumacher, Phil (2005). FAQ's of Summer Weather. National Weather Service, Sioux Falls, South Dakota. Retrieved on 2007-02-28.
  20. ^ Edwards, Roger. Wedge Tornado. National Weather Service Storm Prediction Center. Retrieved on 2007-02-28.
  21. ^ Edwards, Roger. Rope Tornado. National Weather Service Storm Prediction Center. Retrieved on 2007-02-28.
  22. ^ Doswell, Dr. Charles A, III. The Tri-State Tornado of 18 March 1925 Reanalysis Project (Powerpoint Presentation). Retrieved on 2007-04-07.
  23. ^ a b Edwards, Roger. Public Domain Tornado Images. National Severe Storms Laboratory. Retrieved on 2006-10-20.
  24. ^ a b Lloyd, Linda Mercer. (1996). Target: Tornado [Videotape]. Atlanta, Georgia: The Weather Channel Enterprises, Inc..
  25. ^ R. Monastersky (1999-05-15). Oklahoma Tornado Sets Wind Record. Science News 308–309. Retrieved on 2006-10-20.
  26. ^ Justice, Alonzo A (May 1930). Seeing the Inside of a Tornado (PDF). Monthly Weather Review 205–206. American Meteorological Society. Retrieved on 2006-10-20.
  27. ^ Hall, Roy S. (2003). "Inside a Texas Tornado", Tornadoes. Farmington Hills, MI: Greenhaven Press, 59–65. ISBN 0-7377-1473-5. 
  28. ^ Davies-Jones, Robert (October 1984). "Streamwise Vorticity: The Origin of Updraft Rotation in Supercell Storms". Journal of the Atmospheric Sciences 41 (20): 2991–3006. American Meteorological Society. Retrieved on 2007-04-13. 
  29. ^ Rotunno, Richard; Joseph Klemp (February 1985). "On the Rotation and Propagation of Simulated Supercell Thunderstorms". Journal of the Atmospheric Sciences 42 (3): 271–292. American Meteorological Society. Retrieved on 2007-04-13. 
  30. ^ Wicker, Louis J.; Robert B. Wilhelmson (August 1995). "Simulation and Analysis of Tornado Development and Decay within a Three-Dimensional Supercell Thunderstorm". Journal of the Atmospheric Sciences 52 (15): 2675–2703. American Meteorological Society. Retrieved on 2007-04-13. 
  31. ^ Forbes, Greg. weather.com - Blog: The Weather Channel on weather news, hurricanes, tornadoes & meteorology. Retrieved on 2006-12-30.
  32. ^ Monteverdi, John (2003-01-25). Sunnyvale and Los Altos, CA Tornadoes May 4, 1998. Retrieved on 2006-10-20.
  33. ^ Abdullah, Abdul (April 1966). "The "Musical" Sound Emitted by a Tornado"". Monthly Weather Review 94 (4): 213–220. American Meteorological Society. 
  34. ^ Hoadley, David (March 1983). "Tornado Sound Experiences". Stormtrack 6 (3): 5-9. 
  35. ^ Bedard, A. J. (January 2005). "Low-Frequency Atmospheric Acoustic Energy Associated with Vortices Produced by Thunderstorms". Monthly Weather Review 133 (1): 241–263. American Meteorological Society. 
  36. ^ a b c Bluestein, Howard (August 1999). "A History of Severe-Storm-Intercept Field Programs". Weather and Forecasting 14 (4): 558–577. American Meteorological Society. 
  37. ^ Tatom, Frank; Kevin R. Knupp, and Stanley J. Vitto (February 1995). "Tornado Detection Based on Seismic Signal". Journal of Applied Meteorology 34 (2): 572–582. American Meteorological Society. 
  38. ^ Samaras, Tim M. (October 2004). "A Historical Perspective of In-Situ Observations within Tornado Cores". Preprints of the 22nd Conference on Severe Local Storms, Hyannis, MA: American Meteorological Society. 
  39. ^ Perez, Antony H.; Louis J. Wicker, and Richard E. Orville (September 1997). "Characteristics of Cloud-to-Ground Lightning Associated with Violent Tornadoes". Weather and Forecasting 12 (3): 428-437. 
  40. ^ Lee, Julian J.; Timothy P. Samaras, Carl R. Young (October 2004). "Pressure Measurements at the ground in an F-4 tornado". Preprints of the 22nd Conference on Severe Local Storms, Hyannis, Massachusetts: American Meteorological Society. 
  41. ^ Markowski, Straka, and Rasmussen (2002-10-14). Tornadogenesis Resulting from the Transport of Circulation by a Downdraft: Idealized Numerical Simulations. Journal of the Atmospheric Sciences: Vol. 60, No. 6 28. Retrieved on 2006-09-13.
  42. ^ Brooks, Harold E. (2004-04-01). On the Relationship of Tornado Path Length and Width to Intensity. Weather and Forecasting: Vol. 19, No. 2 310–319. Retrieved on 2007-04-06.
  43. ^ a b Edwards, Moller, Purpura et al (2005). Basic Spotters’ Field Guide (PDF). US Department of Commerce, National Weather Service. Retrieved on 2006-11-01.
  44. ^ Dotzek, Nikolai, Jürgen Grieser, Harold E. Brooks (2003-03-01). Statistical modeling of tornado intensity distributions (PDF). Atmospheric Research: Vol. 67–68 163–187. Retrieved on 2007-04-06.
  45. ^ a b Dr. Nikolai Dotzek (March 2003). "An updated estimate of tornado occurrence in Europe" (PDF). Atmospheric Research. Retrieved on 2007-03-11. 
  46. ^ a b Paul, Bhuiyan (2004). The April 2004 Tornado in North-Central Bangladesh: A Case for Introducing Tornado Forecasting and Warning Systems. Retrieved on 2006-08-17.
  47. ^ Kelly, Schaefer, McNulty, et al. (1978-04-10). An Augmented Tornado Climatology (PDF). Monthly Weather Review 12. Retrieved on 2006-09-13.
  48. ^ Tornado: Diurnal patterns. Encyclopædia Britannica Online pg. 6 (2007). Retrieved on 2007-02-27.
  49. ^ Holzer, A. M. (2000). "Tornado Climatology of Austria". Atmospheric Research (56): 203–211. Retrieved on 2007-02-27. 
  50. ^ Dotzek, Nikolai (2000-05-16). "Tornadoes in Germany" (PDF). Atmospheric Research. Retrieved on 2007-02-27. 
  51. ^ South African Tornadoes. South African Weather Service (2003). Retrieved on 2007-05-21.
  52. ^ Finch, Jonathan D.; Dewan, Ashraf M. Bangladesh Tornado Climatology. Retrieved on 2007-02-27.
  53. ^ Edwards, Roger; Steven J. Weiss (Feb 1996). "Comparisons between Gulf of Mexico Sea Surface Temperature Anomalies and Southern U.S. Severe Thunderstorm Frequency in the Cool Season". 18th Conference on Severe Local Storms, San Francisco, CA: American Meteorological Society. 
  54. ^ Cook, Ashton Robinson; Joseph T. Schaefer (2008-01-22). "The Relation of El Nino Southern Oscillation (ENSO) to Winter Tornado Outbreaks". 19th Conference on Probability and Statistics, New Orleans, LA: American Meteorological Society. 
  55. ^ Solomon, Susan; et al (2007). Climate Change 2007 - The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK and New York, USA: Cambridge University Press for the Intergovernmental Panel on Climate Change. ISBN 9780521880091. 
  56. ^ Severe Thunderstorm Warning Service in NSW and the ACT. Australian Government Bureau of Meteorology (2006). Retrieved on 2006-10-25.
  57. ^ European Severe Weather Database. European Severe Storms Laboratory. Retrieved on 2006-10-25.
  58. ^ TorDACH Homepage. TorDACH. Retrieved on 2006-10-25.
  59. ^ Markowski, Paul M. (April 2002). "Hook Echoes and Rear-Flank Downdrafts: A Review". Monthly Weather Review 130 (4): 852-876. 
  60. ^ Doswell, Charles A. III; Alan R. Moller and Harold E. Brooks (August 1999). "Storm Spotting and Public Awareness since the First Tornado Forecasts of 1948". Weather and Forecasting 14 (4): 544-557. 
  61. ^ What is SKYWARN?. National Weather Service. Retrieved on 2007-02-27.
  62. ^ a b Tornado Detection at Environment Canada. Environment Canada (2004-06-02). Retrieved on 2007-03-16.
  63. ^ Skywarn Europe Retrieved on 2007-05-18
  64. ^ Questions and Answers about Tornadoes. A Severe Weather Primer. National Severe Storms Laboratory (2006-11-15). Retrieved on 2007-07-05.
  65. ^ Brooks, Harold E.; Doswell, Charles A, III (September 2000). Normalized Damage from Major Tornadoes in the United States: 1890–1999. Retrieved on 2007-02-28.
  66. ^ Hoxit, Lee R; Chappell, Charles F (October 1975). Tornado Outbreak of April 3–4, 1974; Synoptic Analysis (PDF). National Oceanic and Atmospheric Administration. Retrieved on 2007-03-02.
  67. ^ Grazulis, Thomas P. (1999). Tornado Oddities. Retrieved on 2007-02-28.
  68. ^ Edwards, Roger. Tornado Safety. Storm Prediction Center. Retrieved on 2007-02-28.
  69. ^ Storm Shelters (PDF). National Weather Service, Huntsville Alabama (August 2002). Retrieved on 2007-02-28.
  70. ^ a b Miller; Doswell, Brooks et al (October 1999). Highway Overpasses as Tornado Shelters. National Weather Service, Norman, Oklahoma. Retrieved on 2007-02-28.
  71. ^ a b c Grazulis, Thomas P (2001). "Tornado Myths", The Tornado: Nature's Ultimate Windstorm. Norman, OK: University of Oklahoma Press. ISBN 0-8061-3258-2. 
  72. ^ a b c Myths and Misconceptions about Tornadoes. The Tornado Project (1999). Retrieved on 2007-02-28.
  73. ^ Cappella, Chris (2005-05-17). Overpasses are tornado death traps. USA Today. Retrieved on 2007-02-28.
  74. ^ Tornado, Rockwell Pass, Sequoia National Park, July 7, 2004 (English) (2006-09-13).
  75. ^ VORTEX: Unraveling the Secrets. National Severe Storms Laboratory (2006). Retrieved on 2007-02-28.
  76. ^ Rasmussen, Erik (2000-12-31). Tornado Forecasting. Severe Storms Research by Erik Rasmussen and Collaborators. Retrieved on 2007-03-27.

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 363rd day of the year (364th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 275th day of the year (276th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 251st day of the year (252nd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ... The Storm Prediction Center, located in Norman, Oklahoma, is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service, which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. government. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 251st day of the year (252nd in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ... is the 131st day of the year (132nd in leap years) in the Gregorian calendar. ... Science News is an American weekly magazine devoted to short articles about new scientific and technical developments, typically gleaned from recent scientific and technical journals. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 263rd day of the year (264th in leap years) in the Gregorian calendar. ... The Encyclopædia Britannica is a general English-language encyclopaedia published by Encyclopædia Britannica, Inc. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 80th day of the year (81st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... 17 November is also the name of a Marxist group in Greece, coinciding with the anniversary of the Athens Polytechnic uprising. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 79th day of the year (80th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 263rd day of the year (264th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 80th day of the year (81st in leap years) in the Gregorian calendar. ... is the 124th day of the year (125th in leap years) in the Gregorian calendar. ... Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ... USA Today is a national American daily newspaper published by the Gannett Company. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 139th day of the year (140th in leap years) in the Gregorian calendar. ... USA Today is a national American daily newspaper published by the Gannett Company. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 139th day of the year (140th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 263rd day of the year (264th in leap years) in the Gregorian calendar. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 263rd day of the year (264th in leap years) in the Gregorian calendar. ... Detroit redirects here. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 272nd day of the year (273rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 7 is the 97th day of the year in the Gregorian calendar (98th in leap years). ... The National Severe Storms Laboratory (NSSL) is a weather research laboratory based in Norman, Oklahoma. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Atlanta redirects here. ... The Weather Channel (TWC) is a cable and satellite television network that broadcasts weather and weather-related news 24 hours a day. ... Events of 2008: (EMILY) Me Lesley and MIley are going to China! This article is about the year. ... is the 135th day of the year (136th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Monthly Weather Review is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Journal of the Atmospheric Sciences is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 103rd day of the year (104th in leap years) in the Gregorian calendar. ... Journal of the Atmospheric Sciences is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 103rd day of the year (104th in leap years) in the Gregorian calendar. ... Journal of the Atmospheric Sciences is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 103rd day of the year (104th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 364th day of the year (365th in leap years) in the Gregorian calendar. ... Year 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... is the 25th day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Monthly Weather Review is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Stormtrack was the first magazine for and about storm chasing. ... Monthly Weather Review is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Weather and Forecasting is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Journal of Applied Meteorology and Climatology (formerly Journal of Applied Meteorology) is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Weather and Forecasting is a publication of the American Meteorological Society. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Also see: 2002 (number). ... is the 287th day of the year (288th in leap years) in the Gregorian calendar. ... Journal of the Atmospheric Sciences is a publication of the American Meteorological Society. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... is the 91st day of the year (92nd in leap years) in the Gregorian calendar. ... Weather and Forecasting is a publication of the American Meteorological Society. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 305th day of the year (306th in leap years) in the Gregorian calendar. ... Year 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... is the 60th day of the year (61st in leap years) in the Gregorian calendar. ... Atmospheric Research (ISSN 0169-8095) is scientific journal dealing with the part of the atmosphere where meteorological events occur; intended for atmospheric scientists (such as meteorologists and climatologists), aerosol scientists, and hydrologists. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 70th day of the year (71st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 229th day of the year (230th in leap years) in the Gregorian calendar. ... Year 1978 (MCMLXXVIII) was a common year starting on Sunday (link displays the 1978 Gregorian calendar). ... is the 100th day of the year (101st in leap years) in the Gregorian calendar. ... Monthly Weather Review is a publication of the American Meteorological Society. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ... is the 136th day of the year (137th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... The South African Weather Service (SAWS) is the meteorological service under the South African governments Department of Environmental Affairs and Tourism. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 141st day of the year (142nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 22nd day of the year in the Gregorian calendar. ... The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... Susan Solomon (born 1956 in Chicago)[1] is an atmospheric chemist working for the National Oceanic and Atmospheric Administration. ... The headquarters of the Cambridge University Press, in Trumpington Street, Cambridge. ... IPCC is the science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), to evaluate the risk of climate change brought on by humans, based mainly on... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 298th day of the year (299th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 298th day of the year (299th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 298th day of the year (299th in leap years) in the Gregorian calendar. ... Monthly Weather Review is a publication of the American Meteorological Society. ... Weather and Forecasting is a publication of the American Meteorological Society. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 58th day of the year in the Gregorian calendar. ... Environment Canada is the department of the government of Canada with responsibility for coordinating environmental policies and programs as well as preserving and enhancing the natural environment and conservation of wildlife. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... is the 153rd day of the year (154th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 75th day of the year (76th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 138th day of the year (139th in leap years) in the Gregorian calendar. ... The National Severe Storms Laboratory (NSSL) is a weather research laboratory based in Norman, Oklahoma. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 319th day of the year (320th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 186th day of the year (187th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 61st day of the year (62nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 137th day of the year (138th in leap years) in the Gregorian calendar. ... USA Today is a national American daily newspaper published by the Gannett Company. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 256th day of the year (257th in leap years) in the Gregorian calendar. ... The National Severe Storms Laboratory (NSSL) is a weather research laboratory based in Norman, Oklahoma. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 59th day of the year in the Gregorian calendar. ... Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ... is the 365th day of the year (366th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 86th day of the year (87th in leap years) in the Gregorian calendar. ...

Further reading

  • Grazulis, Thomas P (January 1997). Significant Tornadoes Update, 1992–1995. St. Johnsbury, VT: Environmental Films. ISBN 1-879362-04-X. 
  • Bradford, Marlene (2001). Scanning the Skies: a History of Tornado Forecasting. University of Oklahoma Press. ISBN 0-8061-3302-3. 
  • Bluestein, Howard B (1999). Tornado Alley: Monster Storms of the Great Plains. Oxford University Press. ISBN 0-19-510552-4. 

Thomas P. Grazulis (born 1942) is a meteorologist who has written extensively about tornadoes and is head of the Tornado Project. ...

External links

General
Research
Safety and Preparedness

The National Severe Storms Laboratory (NSSL) is a weather research laboratory based in Norman, Oklahoma. ... The National Geographic Magazine, later shortened to National Geographic, is the official journal of the National Geographic Society. ...


  Results from FactBites:
 
Tornadoes....Nature's Most Violent Storms (2198 words)
A tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground.
Tornadoes in the winter and early spring are often associated with strong, frontal systems that form in the Central States and move east.
Remember, tornadoes occasionally develop in areas in which a severe thunderstorm watch or warning is in effect.
Tornado - Wikipedia, the free encyclopedia (5017 words)
A tornado is a violently rotating column of air which is in contact with both a cumulonimbus (or, in rare cases, cumulus) cloud base and the surface of the earth.
The longest modern-day damage path was caused by a tornado which was on the ground for 160 miles (260 km) in northeastern North Carolina on November 22, 1992.
Tornadoes occurring in these conditions are especially dangerous, since only radar observations, or possibly the sound of an approaching tornado, serve as any warning to those in the storm's path.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m