and nine are officially rated EF5 on the Enhanced Fujita scale (with dates of occurrence between May 4, 2007, and May 20, 2013). In total, 57 of these tornadoes have been rated F5 and ten have been rated EF5. Possible F5/EF5/T10+ tornadoes officially rated F4/EF4/T9 or lower Because the distinctions between F4/EF4/T9 and F5/EF5/T10 tornadoes are often ambiguous, the official ratings of numerous other tornadoes formally rated below F5/EF5/T10 or equivalent have been disputed, with certain government sources or independent studies contradicting the official record. This list includes tornadoes rated F5/EF5/IF5/T10 by government meteorologists, non-government employeed tornado experts (i.e. Thomas P. Grazulis or Ted Fujita) or meteorological research institutions (i.e. European Severe Storms Laboratory) that rated a tornado differently than the official government organization in charge of the rating. Published academic papers or presentations at academically held meteorological conferences that rate tornadoes as F5/EF5/IF5/T10 or present some evidence to support damage or winds in that category are also ways a tornado can be added to this list. This list can also include tornadoes previously officially rated as an F5 or EF5, but have since been downgraded officially to a lower rating. This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by participating in discussions about tornadoes for this list. Possible F5/EF5/T10+ 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/T10+ 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/T10+ 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/T10+ tornadoes, despite not being rated as such in official records. This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by participating in discussions about tornadoes for this list. See also Tornado intensity and damage List of tornadoes and tornado outbreaks List of F4 and EF4 tornadoes List of F4 and EF4 tornadoes (2010–2019) List of F4 and EF4 tornadoes (2020–present) List of tornadoes striking downtown areas Tornado myths Notes References Bibliography External links F5 Tornadoes in the U.S. since 1950 (SPC/NOAA) U.S. F5 tornadoes