User:CapeVerdeWave/List of F5 and EF5 tornadoes (draft)

This is a list of tornadoes which have been officially or unofficially labeled as F5, EF5, or an equivalent rating, the highest possible ratings on the various tornado intensity scales. These scales – the Fujita scale, the Enhanced Fujita scale, and the TORRO tornado intensity scale – attempt to estimate the intensity of a tornado by classifying the damage caused to natural features and man-made structures in the tornado's path. Tornadoes are among the most violent known meteorological phenomena. Each year, more than 2,000 tornadoes are recorded worldwide, with the vast majority occurring in the United States and Europe. In order to assess the intensity of these events, meteorologist Ted Fujita devised a method to estimate maximum wind speeds within tornadic storms based on the damage caused; this became known as the Fujita scale. The scale ranks tornadoes from F0 to F5, with F0 being the least intense and F5 being the most intense. F5 tornadoes were estimated to have had maximum winds between 261 and 318 mph.

Following two particularly devastating tornadoes in 1997 and 1999, engineers questioned the reliability of the Fujita scale. Ultimately, a new scale was devised that took into account 28 different damage indicators; this became known as the Enhanced Fujita scale. With building design and structural integrity taken more into account, winds in an EF5 tornado were estimated to be in excess of 200 mph. The Enhanced Fujita scale is used predominantly in North America. Most of Europe, on the other hand, uses the TORRO tornado intensity scale (or T-Scale), which ranks tornado intensity between T0 and T11; F5/EF5 tornadoes are approximately equivalent to T10–T11 on the T-Scale.

In the United States, between 1950 and January 31, 2007, a total of 50 tornadoes were officially rated F5, and since February 1, 2007, a total of nine tornadoes have been officially rated EF5. Since 1950, Canada has had one tornado officially rated an F5. Outside the United States and Canada, seven tornadoes have been rated F5/EF5 or equivalent: two each in France, Germany, and Italy and one in Russia.

Several other tornadoes have also been documented as possibly attaining this status, though they are not officially rated as such. The work of tornado expert Thomas P. Grazulis revealed the existence of several dozen likely F5 tornadoes between 1880 and 1995. Grazulis also called into question the ratings of several tornadoes currently rated F5 by official sources. Many tornadoes officially rated F4/EF4 or equivalent have been disputed and described as actual F5/EF5 or equivalent tornadoes, and vice versa; since structures are completely destroyed in both cases, distinguishing between an EF4 tornado and an EF5 tornado is often very difficult.

List of events
The tornadoes on this list have been formally rated F5 by an official government source. Unless otherwise noted, the source of the F5 rating is the U.S. National Weather Service (NWS), as shown in the archives of the Storm Prediction Center (SPC) and National Climatic Data Center (NCDC).

Prior to 1950, assessments of F5 tornadoes are based primarily on the work of Thomas P. Grazulis. The NCDC has accepted 38 of his F5 classifications of tornadoes occurring between 1880 and 1950. In addition to the accepted ones, Grazulis rated a further 25 during the same period which were not accepted. Grazulis' work has identified 16 additional F5 tornadoes between 1950 and 1995, with four later being accepted by the NCDC. From 1950 to 1970, tornadoes were assessed retrospectively, primarily using information recorded in government databases, as well as newspaper photographs and eyewitness accounts. Beginning in 1971, tornadoes were rated by the NWS using on-site damage surveys.

As of February 1, 2007, tornadoes in the United States are rated using the Enhanced Fujita Scale, which replaced the Fujita scale in order to more accurately correlate tornadic intensity with damage indicators and to augment and refine damage descriptors. No earlier tornadoes will be reclassified on the Enhanced Fujita scale, and no new tornadoes in the United States will be rated on the original Fujita scale. France and Canada also adopted the EF-Scale in subsequent years.

Official F5/EF5 tornadoes
Worldwide, a total of 62 tornadoes have been officially rated F5/EF5 since 1950: 59 in the United States and one each in France, Russia, and Canada. Of the 59 tornadoes in the United States, 50 are officially rated F5 on the original Fujita scale (with dates of occurrence between May 11, 1953, and May 3, 1999), and nine are officially rated EF5 on the Enhanced Fujita scale (with dates of occurrence between May 4, 2007, and May 20, 2013). An additional four tornadoes which occurred prior to 1950, all in Europe, have been officially rated F5 or equivalent by the European Severe Storms Laboratory (ESSL) or the Tornado and Storm Research Organisation (TORRO), bringing the worldwide total for official ratings of F5/EF5 or equivalent to 66.

– Official F5/EF5; undisputed – Officially rated F5/EF5, but rating is explicitly disputed among reliable sources; event may not have been F5/EF5

Possible F5/EF5 tornadoes officially rated F4/EF4 or lower
Because the distinctions between F4/EF4 and F5/EF5 tornadoes are often ambiguous, the official ratings of numerous other tornadoes formally rated below F5/EF5 or equivalent have been disputed, with certain government sources or independent studies contradicting the official record.

– Listed as an F5/EF5 on the 2000 NCDC tornado climatology memorandum – Rated or mentioned as a possible F5/EF5 by tornado expert Thomas P. Grazulis – Rated or mentioned as a possible F5/EF5 by an international agency

Possible F5/EF5 tornadoes with no official rating
Many other tornadoes have never been formally rated by an official government source but have nonetheless been described as F5/EF5 or equivalent, often by independent studies. Most of these tornadoes occurred prior to 1950, before tornadoes were rated according to standardized damage assessments, and their unofficial classifications as F5/EF5 or equivalent have been made in retrospect, largely on the basis of photographic analysis and eyewitness accounts. A few, such as the Tri-State Tornado of 1925, are widely accepted as F5/EF5 tornadoes, despite not being rated as such in official records.

– Listed as an F5/EF5 on the 2000 NCDC tornado climatology memorandum – Rated or mentioned as a possible F5/EF5 by tornado expert Thomas P. Grazulis – Rated or mentioned as a possible F5/EF5 by an international agency