For a more complete explanation of the Fujita & Enhanced Fujita Scales,

go to

http://www.spc.noaa.gov/efscale/

F
Scale
#

Intensity
Phrase

Wind
Speed
(mph)

Type of Damage Done

F0
Gale Tornado
40-72
Some damage to chimneys; breaks branches off trees; pushes over shallow-rooted trees; damages sign boards.

F1
Moderate Tornado
73-112
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
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
Roof and some walls torn off well constructed houses; trains overturned; most trees in forest uprooted.

F4
Devastating Tornado
207-260
Well-constructed houses leveled; structures with weak foundations blown off some distance; cars thrown and large missiles generated.

F5
Incredible Tornado
261-318
Strong frame houses lifted off foundations and carried considerable distances to disintegrate; automobile sized missiles fly through the air in excess of 100 meters; trees debarked; steel re-enforced concrete structures badly damaged.

F6
Inconceivable Tornado
319-379
These winds are very unlikely. The 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 refrigerators would do serious secondary damage that could not be directly identified as F6 damage. If this level is ever achieved, evidence for it might only be found in some manner of ground swirl pattern, for it may never be identifiable through engineering studies.