F-Scale Number
|
Common terms |
Wind Speed |
What Kind
of Damage is Done |
| F0 |
Mild tornado |
40-72 mph |
Some damage 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 fly through air. |
| F3 |
Severe tornado |
158-206 mph |
Roof and some walls torn off well constructed
houses; trains can be overturned; most trees in forest uprooted. |
| F4 |
Devastating tornado |
207-260 mph |
Well-constructed houses knocked down; structures
with weak foundations blown off some distance; cars thrown. |
| F5 |
Extremely devastating tornado |
261-318 mph |
Strong frame houses lifted off foundations
and carried considerable distances; very large (car size)
objects can fly through the air in excess of 100 meters; trees
debarked; steel reinforced concrete structures badly damaged. |
Tornado
size is measured using the Fujita scale developed by Dr.
T. Theodore Fujita which relates the amount of damage
caused to the wind speed. The scale is only a general
idea and shouldn't be thought of as what really happened
since wind speeds inside tornadoes have never been scientifically
observed.