What is the Fujita scale and what is it used for?
The Fujita scale is a scale for rating tornado intensity based on damage to human-built structures and vegetation.Depending on the circumstances, ground-swirl patterns, weather radar data, witness testimonies, media reports and damage imagery are used to determine the official Fujita scale category.The Enhanced Fujita scale was introduced in the United States in February of 2007.The Fujita scale and 31 "Specific Damage Indicators" were used by Environment Canada in their ratings.It was [1][2].
The National Severe Storms Forecast Center/NSSFC was founded in 1971 by Ted Fujita of the University of Chicago and Allen Pearson.The scale was updated in 1973.In 1973, tornadoes were rated in the United States.The Fujita scale was applied retroactively to tornadoes reported between 1950 and 1972.Tom Grazulis of The Tornado Project retroactively rated all known significant tornadoes (F2–F5 or causing a fatality) in the U.S. back to 1880.Most areas outside of Great Britain adopted the Fujita scale.There is a citation needed.
The Enhanced Fujita Scale was introduced in the United States on February 1, 2007.The new scale matches the severity of the tornado damage with wind speeds.
The Fujita scale is a damage scale and the wind speeds associated with the damage listed aren't rigorously verified.Research suggested that the wind speeds needed to cause damage by tornadoes on the Fujita scale are overstated.The wind speeds are biased to the United States because of a process of expert elicitation.The damage parameters were improved by the scale.
The scale Fujita created was a theoretical 13 level scale designed to connect the two scales.F1 and F12 correspond to the twelfth and eleventh levels of the scale.The position F0 was placed in was similar to how the zeroth level of the scale specifies little to no wind.qualitative descriptions of damage were made for each category of the Fujita scale and used to classify tornadoes.The diagram on the right shows the relationship between the number scales.
The original scale presented little more than educated guesses at wind speed ranges for specific tiers of damage, as little information was available at the time Fujita derived the scale.Fujita intended that only F0–F5 be used in practice, as this covered all possible levels of damage to frame homes as well as the estimated bounds of wind speeds.He added a description for F6 to allow for the possibility of wind speeds exceeding F5 and damage analysis that might show it.Fujita assigned the strongest tornado of the 1974 Super Outbreak, which affected Xenia, Ohio, a preliminary rating of F6 intensity 1 scale based on aerial photographs.[9]
The original wind speed numbers have been found to be higher than the actual speeds required to cause damage.The error increases as the category increases, especially in the range of F3 through F5.The wind speed numbers have never been scientifically verified.Different wind speeds can cause damage from place to place.The wind speeds needed to cause tornado damage are unknown without a thorough engineering analysis.The Enhanced Fujita Scale has been created using better wind estimates.
There was damage to chimneys, branches broken off trees, and sign boards.
The lower limit is the beginning of the wind's speed, which can include peeling off roofs, mobile homes being pushed off foundations, and moving vehicles being thrown off the road.
Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; high-rise windows broken and blown in; light-object generated missiles.
Heavy cars lifted off the ground and were thrown after roofs and some walls torn off well-constructed houses.