To classify the intensity of a tornado, many meteorologists use the "Fujita-Pearson
Scale or otherwise known as simply the "Fujita Scale."
In 1971 Theodore Fujita, a meteorology professor at the University of
Chicago, devised a classification system based on damage to manmade structures.
Dr. Fujita teamed up with Dr. Pearson two years later to finish the "Fujita-Pearson
Scale"
The Fujita Scale
The Fujita Scale is used to rate the intensity of a tornado
by examining the damage caused by the tornado after it has passed over
a man-made structure.
| F-Scale Number |
Intensity Phrase |
Wind Speed |
Type of Damage Done |
| F 0 |
Gale Tornado |
40-72 mph |
Some Damage done to chimneys; breaks branches off trees; pushes
over shallow-rooted trees; damages sign boards.
|
| F1 |
Moderate Tornado |
73-112 mph |
The lower limit is the beginning of hurricane wind speed; peels
surface off roofs; mobile homes pushed off foundations or overturned;
moving autos pushed off the roads; attached garages may be destroyed
|
| F2 |
Significant Tornado |
113-157 mph |
Considerable damage. Roofs torn off frame houses; mobile homes
demolished; boxcars pushed over; large trees snapped or uprooted;
light object missiles generated.
|
| F3 |
Severe tornado |
158-206 mph |
Roof and some walls torn off well constructed houses;
trains overturned; most trees in fores uprooted. |
| F4 |
Devastating Tornado |
207-260 mph |
Well- constructed houses leveled; structures
with weak foundations blown off some distance; cars thrown and large
missiles generated. |
| F5 |
Incredible Tornado |
261-318mph |
Strong frame houses lifted off foundations
and carried considerable distances to disinigrate; automobile sized
missiles fly through the air in excess of 100 meters; trees debarked;
steel re-inforced concrete structures badly damaged |
| F6 |
Inconcievable Tornado |
319-379 mph |
Small area of damage they might produce
would probably not be recognizable along with the mess produced by
F4 and F5 wind that would surround the F6 winds. Missiles, such as
cars and houshold electrical appliances would do serious secondary
damage that could not be directly identified as F6 damage. If this
level is ever achieved, evidence for it might not only be found in
some manner of ground swirl pattern, for it may never be identifiable
through engineering studies. |
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