The Fujita scale is used to classify the extent of a storm's damage and power.
Gale Tornado Wind Speed: 40-72 mph
Damage: Some damage to chimneys, breaks branches off trees, pushes over shallow-rooted trees, damages sign boards.
Moderate Tornado Wind Speed: 73-112 mph
Damage: The lower limit is the begriming 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.
Significant Tornado Wind Speed: 113-157 mph
Damage: Considerable damage. Roofs torn off frame houses, mobile homes demolished, boxcars pushed over, large trees snapped or uprooted, light object missiles generated.
Severe Tornado Wind Speed: 158-206
Damage: Roof and some walls torn off well-constructed houses, trains overturned, most trees in forest uprooted.
Devastating Tornado Wind Speed: 207-260 mph
Damage: Well-constructed houses leveled, structures with weak foundations blown off some distance, cars thrown, large missiles generated.
Incredible Tornado Wind Speed: 261-318 mph
Damage: 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 reinforced concrete structures badly damaged.