Fujita Scale
The Fuijita 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. The scale is named for the late Professor Tetsuya Theodore Fujita, who co-developed the ratings.
Category F0: Light Damage (less than 73 mph winds); Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged.
Category F1: Moderate Damage (73 to 112 mph winds); Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off road.
Category F2: Considerable Damage (113 to 157 mph winds); Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.
Category F3: Severe Damage (158 to 206 mph winds); Roofs and some walls torn off well-constructed houses, trains overturned; most trees in forest uprooted; heavy cars lifted off ground and thrown.
Category F4: Devastating Damage (207 to 260 mph winds); Well-constructed houses leveled; structure with weak foundations blown off some distance; cars thrown and large missiles generated.
Category F5: Incredible Damage (261 to 318 mph); Strong frame houses lifted off foundations and swept away; automobile sized missiles fly through the air in excess of 100 meters (109 yards); trees debarked; incredible phenomena will occur.
Category F6: Inconceivable Damage (319 to 379 mph); If this is ever achieved, evidence for it might only be found is some manner of ground swirl pattern, for it may never be identifiable through engineering studies.
Category F0: Light Damage (less than 73 mph winds); Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged.
Category F1: Moderate Damage (73 to 112 mph winds); Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off road.
Category F2: Considerable Damage (113 to 157 mph winds); Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.
Category F3: Severe Damage (158 to 206 mph winds); Roofs and some walls torn off well-constructed houses, trains overturned; most trees in forest uprooted; heavy cars lifted off ground and thrown.
Category F4: Devastating Damage (207 to 260 mph winds); Well-constructed houses leveled; structure with weak foundations blown off some distance; cars thrown and large missiles generated.
Category F5: Incredible Damage (261 to 318 mph); Strong frame houses lifted off foundations and swept away; automobile sized missiles fly through the air in excess of 100 meters (109 yards); trees debarked; incredible phenomena will occur.
Category F6: Inconceivable Damage (319 to 379 mph); If this is ever achieved, evidence for it might only be found is some manner of ground swirl pattern, for it may never be identifiable through engineering studies.
