bodyType

customContents

entityId

entityUuid

articlePageQuery

filter

article

articleBaseAdvertisingInfoArticle

articleListArticle

articleSeoArticle

hooksArticleAcknowledgementGateOverlayArticle

hooksTrackPageViewArticle

hooksContentInterestArticle

articleLinkingDataContent

hooksAmpRedirectArticle

articleSchemaContent

liveArticle

advertZone

sentiment

contentLock

topics

types

sections

paywallTypes

createdDate

publishedDate

urlAlias

moreOnThisArticles

sponsorType

commentCount

authorLocations

authors

corrections

displaySlideShow

multimediaEmbed

printHeadline

seriesContainer

articleSpeeches

socialHeadline

headline

images

flag

firstTopic

glossary

flattenTypeIds

image

relatedLinks

relatedNewsletters

__typename

sponsor

pdfFiles

seriesReverseOrder

series

disableOffPlatformContent

published

updatedDate

summary

subHeadline

body

keywords

readingTime

customTimezone

liveContents

Reuters

The tornado that slammed into the Oklahoma City suburb of Moore on Monday was given a preliminary ranking of EF4, the second most powerful category on the Enhanced Fujita Scale.
The Enhanced Fujita scale is an updated version of an earlier chart to measure the ferocity of tornadoes published in 1971 by University of Chicago professor Tetsuya Fujita.

In rating the intensity of tornadoes, meteorologists and other experts study damage on the ground, along with wind speeds and other data, to rate twisters between EF0 (the weakest) and EF5 (the most intense).
The scale is as follows:
 


		An EF5 tornado, capable of causing incredible damage, is characterised by three-second wind gusts of 320-376km/h and can level strong-framed houses off their foundations, according to the National Oceanic and Atmospheric Administration (NOAA).

 
Car-sized missiles can fly through the air in excess of 100 metres and trees can be stripped of their bark.
On May 3, 1999, a tornado rated as an F5 under the original Fujita scale also struck Moore, killing 40 people and destroying thousands of homes.
A tornado that struck the town of Joplin, Missouri, on May 22, 2011, was also an EF5.
 


		An EF4 tornado can cause devastating damage and is capable of levelling well-constructed homes and blowing away those with weak foundations.

 
Cars can be thrown and large missiles generated. Such a twister includes wind gusts of 270-320km/h.
The tornado that struck Moore on Monday, ripping up at least two schools, has been preliminarily rated an EF4, according to a spokeswoman for the National Weather Service Storm Prediction Centre in Norman, Oklahoma.
 


		An EF3 tornado can cause severe damage, tearing roofs and walls off well-constructed homes, uprooting trees and lifting cars off the ground and throwing them. It has wind gusts of 220-270km/h. Several EF3 tornadoes have been recorded in the US this year, including one that touched down in Kemper County, Mississippi, in April, killing one person and injuring four.

 
 


		An EF2 tornado can cause considerable damage, tearing roofs off frame homes, demolishing mobile homes, overturning boxcars and snapping or uprooting large trees.

 
Such a tornado is characterised by wind gusts of 177-220km/h. Several EF2 tornadoes have struck the US so far this year, in some cases causing injuries or substantial damage.
 


		An EF1 tornado can cause moderate damage, with wind gusts of between 138 and 177km/h. Damage caused in such twisters includes surfaces peeled off roofs, mobile homes pushed off foundations or overturned and cars blown off roads.

 
 


		An EF0 tornado causes light damage with wind gusts of 104-136 km/h. The impact can include damage to chimneys, branches broken off trees and shallow-rooted trees being knocked over.


TORNADO DEATH TOLL
People killed by the 10 deadliest tornadoes in the US since 1900:
695 deaths. March 18, 1925, in Missouri, Illinois and Indiana.
216 deaths. April 5, 1936, in Tupelo, Mississippi.
203 deaths. April 6, 1936, in Gainesville, Georgia.
181 deaths. April 9, 1947, in Woodward, Oklahoma.
158 deaths. May 22, 2011, in Joplin, Missouri.
143 deaths. April 24, 1908, in Amite, Louisiana, and Purvis, Mississippi.
116 deaths. June 8, 1953, in Flint, Michigan.
114 deaths. May 11, 1953 in Waco, Texas.
114 deaths. May 18, 1902 in Goliad, Texas.
103 deaths. March 23, 1913, in Omaha, Nebraska.
 
Associated Press


Oklahoma tornado ranked in second place on power scale

Rescue workers look through the rubble at Plaza Towers Elementary school in Moore. Photo: Reuters

Tornado survivors describe terror of sheltering in buildings being ripped apart

Injured teachers lead children away from Briarwood Elementary school. Photo: AP

Monday's enormous tornado ploughed a 32-kilometre of destruction trail through the suburbs of Oklahoma City. Photo: AP

Firemen check on an elderly resident who lost his home. Photo: AP

The path of the tornado as it struck the Oklahoma City suburb of Moore

The tornado flattened entire neighbourhoods and destroyed schools and a hospital. Photo: AP

Survivors pulled from Oklahoma tornado debris as toll falls

Victor Gonzalez seeks shelter from the rain under a sheet of plastic as he helps a friend salvage items from his tornado-ravaged home. Photo: AP

Rescue workers help free one of the 15 people that were trapped in a medical building at the Moore hospital complex in Moore. Photo: Reuters

Two girls stand in rubble after a tornado struck Moore, Oklahoma. Photo: Reuters

News

World

The tornado that slammed into the Oklahoma City suburb of Moore on Monday was given a preliminary ranking of EF4, the second most powerful category on the Enhanced Fujita Scale.
