A look at the Fujita tornado scale

Tornadoes are rated from F0 to F5 on the Fujita scale, based on wind speed and damage. The scale was developed by Theodore Fujita of the University of Chicago.

- F0: Light damage, wind under 73 mph. Some damage to chimneys, branches broken off trees, shallow-rooted trees pushed over, sign boards damaged.

- F1: Moderate damage, wind 73-112 mph. Surfaces peeled off roofs, mobile homes pushed off foundations or overturned, moving autos blown off roads.

- F2: Considerable damage, wind 113-157 mph. Roofs torn off frame houses, mobile homes demolished, boxcars overturned, large trees snapped or uprooted, light objects become missiles.

- F3: Severe damage, wind 158-206 mph. Roofs and some walls torn off well-constructed houses, trains overturned, most trees in forest uprooted, heavy cars lifted off ground and thrown.

- F4: Devastating damage, wind 207-260 mph. Well-constructed houses leveled, structures with weak foundations blown some distance, cars thrown, large missiles generated.

- F5: Incredible damage, wind 261-318 mph. Strong frame houses lifted off foundations and swept away, automobile-sized missiles fly through the air more than 100 yards, trees debarked.