Fujita scale


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Fujita scale

(fo͞ojē`tə, fo͞o`jētə) or

F-Scale,

scale for rating the severity of tornadoes as a measure of the damage they cause, devised in 1951 by the Japanese-American meteorologist Tetsuya (Ted) Fujita (1920–98). Since 2007 the National Weather Service has used the Enhanced Fujita scale or EF-Scale, developed by the Texas Tech Univ. Wind Science and Engineering Research Center in conjunction with other wind engineers and meteorologists. Incorporating improved knowledge of wind speeds and the resulting damage, as well as including more damage indicators (and thus allowing for a more accurate assessment of a tornado based on the destruction it caused), the EF-scale retains the categories used by the Fujita scale but has revised the associated wind speeds.

The revised scale classifies tornadoes on a hierarchy beginning with category EF0, or "light" (winds of 65–85 mph; some damage to chimneys, TV antennas, roof shingles, trees, signs, and windows), which accounts for about 28% of all tornadoes. Category EF1, or "moderate" (winds of 86–110 mph; automobiles overturned, carports destroyed, and trees uprooted), accounts for about 39% of all tornadoes. Category EF2, or "significant" (winds of 111–135 mph; roofs blown off homes, sheds and outbuildings demolished, and mobile homes overturned), accounts for about 24% of all tornadoes. Category EF3, or "severe" (winds of 136–165 mph; exterior walls and roofs blown off homes, metal buildings collapsed or severely damaged, and forests and farmland flattened), accounts for about 6% of all tornadoes. Category EF4, or "devastating" (winds of 166–200 mph; few walls, if any, left standing in well-built homes and large steel and concrete missiles thrown great distances) accounts for about 2% of all tornadoes. Category EF5, or "incredible" (winds of over 200 mph; homes leveled or carried great distances and schools, motels, and other larger structures have considerable damage with exterior walls and roofs gone), accounts for less than 1% of all tornadoes. Under the original Fujita scale, Category F0 had estimated winds of 40–72 mph; F1, 73–112 mph; F2, 113–157 mph; F3, 158–206 mph; F4, 207–260 mph; and F5, 261–318 mph.

References in periodicals archive ?
The Met Office and TORRO (The Tornado and Storm Research Organisation) estimated that the tornado had a general 'T4' rating on the TORRO scale with a short spell as a 'T5' tornado, which would mean wind speeds between 93 and 130 mph, equivalent to an F2 on the Fujita scale.
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The National Weather Service ranks tornado intensity using the Enhanced Fujita Scale.
In a report issued today, Moody's says the monster tornado--rated EF5 on the Enhanced Fujita Scale, with winds of around 200 mph--tracked through both residential and commercial areas of the city, spelling potentially significant losses for both personal and commercial property insurance lines.
On the Enhanced Fujita scale that measures a tornado's strength based on the damage it causes, the twister was an EF-5, the highest possible level, said Kelly Pirtle of the National Weather Service's Severe Storms Laboratory.
Scientists concluded the storm was a rare and extraordinarily powerful type of twister known as an EF5, ranking it at the top of the enhanced Fujita scale used to measure tornado strength.
The storm is thought to have registered a four on what's called the Enhanced Fujita scale, laying waste to scores of buildings and a community of 41,000 people.
WITH winds of more than 200mph the Oklahoma tornado measured EF-5 on the Enhanced Fujita scale, the most powerful.
The National Weather Service upgraded its calculation of the storm's strength on Tuesday, saying it was a rare EF5, the most powerful ranking on the Enhanced Fujita Scale "I LOOKED UP AND SAW THE TORNADO" The last time a giant twister tore through the area, on May 3, 1999, it killed more than 40 people and destroyed thousands of homes.
But depending on the results of damage surveys, this rating could get bumped up to an EF-5, the highest on the Enhanced Fujita scale that measures tornado strength, (http://www.
Spokeswoman Keli Pirtle said Tuesday the agency upgraded the tornado from an EF-4 on the enhanced Fujita scale to an EF-5 based on what a damage assessment team saw on the ground.
The Joplin, Missouri, tornado was deemed an EF-5 on the Enhanced Fujita scale, and no tornado can be rated higher on this scale when it comes to wind strength and intensity.