Tornado Classification
(Classified by Maximum Winds)
     Damage
Speed (mph)
Category
Scale
261-318
207-260
158-206
113-157
73-112
40-72
car-sized structures moved, steel structures damaged
Violent
F5
frame house destroyed
Violent
F4
trees leveled, cars over-turned, walls removed
Strong
F3
large trees uprooted,        weak structures damaged
Strong
F2
trees snapped,             windows broken
Weak
F1
tree branches broken,        sign boards damaged
Weak
F0