The Fujita Tornado
Scale
The Fujita scale or F-scale was developed by Dr.
T. Theodore
Fujita of the
|
Fujita Rating |
Estimated Wind Speed |
Typical Damage |
Frequency |
|
F0 |
Less than 73 mph |
Light Damage - Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged. |
29% |
|
F1 |
73-112 mph |
Moderate Damage - Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off roads. |
40% |
|
F2 |
113-157 mph |
Considerable Damage - Roofs
torn off frame houses; mobile homes demolished; boxcars overturned;
large trees snapped or uprooted; light-object missiles generated; cars
lifted off ground. |
24% |
|
F3 |
158-206 mph |
Severe Damage - Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown. |
6% |
|
F4 |
207-260 mph |
Devastating Damage - Well-constructed houses leveled; structures with weak foundations blown away some distance; cars thrown and large missiles generated. |
2% |
|
F5 |
261-318 mph |
Incredible Damage - Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 meters (109 yds); trees debarked; incredible phenomena will occur. |
Less than 1% |
It
is important to
remember that the wind speeds listed are only very rough estimates and
have not
been scientifically analyzed. The Fujita
scale ratings are assigned subjectively and there is a lot of variation
in damage
depending on how well structures are built.
In addition, the tornado rating is not based on the size of the
funnel
or strength of the wind, but the
damage inflicted. Thus, if a
tornado occurs in an open area where no buildings are present, it could
be
assigned a weaker F-rating than if it hit a man-made structure.
MARCH 13-17, 2006
