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After a tornado, meteorologists look at the damage it caused to estimate its wind speeds, then assign it a numerical ranking of F0 through F5. The “F” stands for “Fujita,” the name of the tornado researcher—Tetsuya Theodore “Ted” Fujita—who developed the original scale in 1971.
On February 1, 2007—just three months before the Greensburg tornado—researchers adopted a revised scale they consider more precise. Called the Enhanced Fujita (EF) Scale, the new scale accounts for variables such as the type and quality of a building’s construction. The Greensburg tornado was the first tornado to be assigned a rating of EF5.
The Enhanced Fujita Scale assigns tornado damage according to the following definitions:
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EF0: Light damage
Some damage to shingles and siding; branches broken off trees; shallow-rooted trees pushed over.
Estimated wind speed: 65–85 mph.
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EF1: Moderate damage
Roofs stripped; mobile homes overturned; trees uprooted; flagpoles bent.
Estimated wind speed: 86–110 mph.
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EF2: Considerable damage
Roofs torn off well-constructed homes; mobile homes destroyed; cars lifted off ground; softwood trees stripped of bark; flagpoles collapsed.
Estimated wind speed: 111–135 mph
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EF3: Severe damage
Entire stories of well-constructed homes destroyed; cars and homes with weak foundations lifted and tossed; trains overturned; hardwood trees debarked.
Estimated wind speed: 136–165 mph.
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EF4: Devastating damage
Well-constructed homes and large sections of school buildings destroyed.
Estimated wind speed: 166–200 mph.
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EF5: Incredible damage
Houses leveled off foundations and swept away; cars thrown more than 100 yards; high-rise buildings structurally deformed.
Estimated wind speed: greater than 200 mph. |
Continue to Chasing Tornadoes. >>
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