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Fujita Scale
The Fujita scale (F-Scale; ), or Fujita–Pearson scale (FPP scale), is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation. The official Fujita scale category is determined by meteorologists and engineers after a ground or aerial damage survey, or both; and depending on the circumstances, ground-swirl patterns (cycloidal marks), weather radar data, witness testimonies, media reports and damage imagery, as well as photogrammetry or videogrammetry if motion picture recording is available. The Fujita scale was replaced with the Enhanced Fujita scale (EF-Scale) in the United States in February 2007. In April 2013, Canada adopted the EF-Scale over the Fujita scale along with 31 "Specific Damage Indicators" used by Environment Canada (EC) in their ratings. Background The scale was introduced in 1971 by Ted Fujita of the University of Chicago, in collaboration with Allen Pearson, head of the National ...
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Tornado Intensity
Tornado intensity can be measured by ''in situ'' or remote sensing measurements, but since these are impractical for wide-scale use, intensity is usually inferred by proxies, such as damage. The Fujita scale, Enhanced Fujita scale, and the International Fujita scale rate tornadoes by the 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. In contrast to other major storms such as hurricanes and typhoons, such classifications are only assigned retroactively. Wind speed alone is not enough to determine the intensity of a tornado.An EF0 tornado will probably damage trees and peel some shingles off the roof. An EF5 tornado can rip well-anchored homes off their foundations, leaving them bare, and can even deform large skyscrapers. The similar TORRO scale ranges from a ...
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Tom Grazulis
Thomas P. Grazulis (born August 17, 1942) is an American meteorologist who has written extensively about tornadoes and is head of ''The Tornado Project''. Biography Early career Thomas Grazulis grew up in Worcester, Massachusetts and first confronted the power of a tornado at age 11 following the violent 1953 Worcester tornado, an F4 which killed 94 people and passed approximately north of his childhood home. Grazulis earned a bachelor's degree in meteorology from Florida State University (FSU) and was briefly a broadcaster, in part presenting the weather. He was a science teacher in New Jersey and worked on the "Earth Science Curriculum Project" with the National Science Foundation (NSF). He and his wife Doris, also a teacher and a small business operator, then moved to the St. Johnsbury, Vermont area in 1970. In 1972, he and Doris released ''Approaching the Unapproachable'', a documentary film on tornadoes that was the first to consider tornadoes in a scientific cont ...
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Km/h
The kilometre per hour ( SI symbol: km/h; non-standard abbreviations: kph, km/hr) is a unit of speed, expressing the number of kilometres travelled in one hour. History Although the metre was formally defined in 1799, the term "kilometres per hour" did not come into immediate use – the myriametre () and myriametre per hour were preferred to kilometres and kilometres per hour. In 1802 the term "''myriamètres par heure''" appeared in French literature. The Dutch on the other hand adopted the kilometre in 1817 but gave it the local name of the ''mijl'' ( Dutch mile). Notation history The SI representations, classified as symbols, are "km/h", "" and "". Several other abbreviations of "kilometres per hour" have been used since the term was introduced and many are still in use today; for example, dictionaries list "kph", "kmph" and "km/hr" as English abbreviations. While these forms remain widely used, they are explicitly disallowed by the International Bureau of Weights and Measure ...
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Miles Per Hour
Miles per hour (mph, m.p.h., MPH, or mi/h) is a British imperial and United States customary unit of speed expressing the number of miles travelled in one hour. It is used in the United Kingdom, the United States, and a number of smaller countries, most of which are UK or US territories, or have close historical ties with the UK or US. Usage Road traffic Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions: * Antigua and Barbuda *Bahamas *Belize * Dominica * Grenada *Liberia (occasionally) *Marshall Islands * Micronesia * Palau * Saint Kitts and Nevis *Saint Lucia *Saint Vincent and the Grenadines * Samoa (along with kilometres per hour) *United Kingdom *The following British Overseas Territories: **Anguilla **British Virgin Islands ** British Indian Ocean Territory ** Cayman Islands **Falkland Islands **Montserrat ** Saint Helena, Ascension and Tristan da Cunha **Turks and Caicos Islands *The Crown dependencies: ** Bail ...
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1999 Bridge Creek–Moore Tornado
On the evening of Monday, May 3, 1999, a large and exceptionally powerful F5 tornado registered the highest wind speeds ever measured globally; winds were recorded at by a Doppler on Wheels (DOW) radar. Considered the strongest tornado ever recorded to have affected the metropolitan area, the tornado devastated southern portions of Oklahoma City, Oklahoma, along with surrounding suburbs and towns to the south and southwest. The tornado covered during its 85-minute existence, destroying thousands of homes, killing 36 people (plus an additional five indirectly), and leaving US$1 billion (1999 USD) in damage, ranking it as the fifth-costliest on record not accounting for inflation. It was the first use of the tornado emergency statement by the National Weather Service. The tornado first touched down at 6:23 p.m. Central Daylight Time (CDT) in Grady County, roughly south-southwest of the town of Amber. It quickly intensified into a violent F4, and gradually r ...
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National Weather Service
The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970. The NWS performs its primary task through a collection of national and regional centers, and 122 local Weather Forecast Offices (WFOs). As the NWS is an agency of the U.S. federal government, most of its products are in the public domain and available free of charge. History Calls for the creation of a government weather bureau began as early as 1844, when the electrica ...
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Tornado Outbreak Of April 1977
A violent severe weather outbreak struck the Southeast on April 4–5, 1977. A total of 21 tornadoes touched down with the strongest ones occurring in Mississippi, Alabama, and Georgia. The strongest was a catastrophic F5 tornado that struck the Northern Birmingham, Alabama suburbs during the afternoon of Monday, April 4, 1977. In the end, the entire outbreak directly caused 24 deaths and over 200 injuries. The storm system also caused the crash of Southern Airways Flight 242, which killed 72 and injured 22. Confirmed tornadoes April 4 event April 5 event Birmingham–Smithfield, Alabama Beginning just a few miles north of Birmingham near Tarrant, the tornado proceeded north through northern Jefferson County producing F5 damage in Smithfield, northeast of Ensley. The tornado, which was at times wide, was blamed for 22 deaths, more than 125 injuries, and $25 million in damage. Hundreds of homes were completely destroyed, many of which were completely swept away, despite ...
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1974 Super Outbreak
The 1974 Super Outbreak was the second-largest tornado outbreak on record for a single 24-hour period, just behind the 2011 Super Outbreak. It was also the most violent tornado outbreak ever recorded, with 30 F4/F5 tornadoes confirmed. From April 3 to 4, 1974, there were 148 tornadoes confirmed in 13 U.S. states and the Canadian province of Ontario. In the United States, tornadoes struck Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia, and New York. The outbreak caused roughly $843 million USD (~equivalent to $4.58 billion in 2019) in damage, with more than $600 million (~equivalent to $3.3 billion in 2019) occurring in the United States. The outbreak extensively damaged approximately along a total combined path length of . At one point, as many as 15 separate tornadoes were on the ground simultaneously. The 1974 Super Outbreak was the first tornado outbreak in recorded history to produce more th ...
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Wind Speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed affects weather forecasting, aviation and maritime operations, construction projects, growth and metabolism rate of many plant species, and has countless other implications. Note that wind direction is usually almost parallel to isobars (and not perpendicular, as one might expect), due to Earth's rotation. Units Metres per second (m/s) is the SI unit for velocity and the unit recommended by the World Meteorological Organization for reporting wind speeds, and is amongst others used in weather forecasts in the Nordic countries. Since 2010 the International Civil Aviation Organization (ICAO) also recommends meters per second for reporting wind speed when approaching runways, replacing their former recommendation of using kilometres pe ...
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Qualitative Data
Qualitative properties are properties that are observed and can generally not be measured with a numerical result. They are contrasted to quantitative properties which have numerical characteristics. Some engineering and scientific properties are qualitative. A test method can result in qualitative data about something. This can be a categorical result or a binary classification (e.g., pass/fail, go/no go, conform/non-conform). It can sometimes be an engineering judgement. The data that all share a qualitative property form a nominal category. A variable which codes for the presence or absence of such a property is called a binary categorical variable, or equivalently a dummy variable. In businesses Some important qualitative properties that concern businesses are: Human factors, 'human work capital' is probably one of the most important issues that deals with qualitative properties. Some common aspects are work, motivation, general participation, etc. Although all of thes ...
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Mach Number
Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac, where: : is the local Mach number, : is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel), and : is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). Pilots of high-altitude aerospace vehicles use flight Mach number to express a vehicle's true airspeed, but the flow field around a vehicle varies in three dimensions, with corresponding variations in local Mach number. The loc ...
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Beaufort Scale
The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. History The scale was devised in 1805 by the Irish hydrographer Francis Beaufort (later Rear Admiral), a Royal Navy officer, while serving on . The scale that carries Beaufort's name had a long and complex evolution from the previous work of others (including Daniel Defoe the century before) to when Beaufort was Hydrographer of the Navy in the 1830s, when it was adopted officially and first used during the voyage of HMS ''Beagle'' under Captain Robert FitzRoy, who was later to set up the first Meteorological Office (Met Office) in Britain giving regular weather forecasts. In the 18th century, naval officers made regular weather observations, but there was no standard scale and so they could be very subjective – one man's "stiff breeze" might be another's "soft breeze". Beaufort succeeded in standardising the ...
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