||Gale Tornado--light damage. Some damage to chimneys; break branches off trees; push over shallow-rooted trees; damage sign boards.
||Moderate Tornado--moderate damage. The lower limit is the beginning of hurricane wind speed; peel surface off roofs; mobile homes pushed off foundations or overturned; moving autos pushed off the roads.
||Significant Tornado--considerable damage. Roofs torn off frame houses; mobile homes demolished; boxcars pushed over; large trees snapped or uprooted; light-object missiles generated.
||Severe Tornado--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.
||Devastating Tornado--devastating damage. Well-constructed houses leveled; structures with weak foundations blown off some distance; cars thrown and large missiles generated.
||Incredible Tornado--Incredible damage. Strong frame houses lifted off foundations and carried considerable distance to disintegrate; automobile-sized missiles fly through the air in excess of 100 meters (109 yds.); trees debarked; incredible phenomena will occur.
|F6 - F12
||319 mph - MACH 1 (speed of sound)
||The maximum wind speeds of tornadoes are not expected to reach the F6 wind speeds.