Fujita scale

"F-scale" redirects here. For other uses, see F scale. The Fujita scale (F-Scale), or Fujita-Pearson scale, is a scale for rating tornado intensity, based on the damage tornadoes inflict on human-built structures and vegetation. The official Fujita scale category is determined by meteorologists (and engineers) after a ground and/or aerial damage survey; and depending on the circumstances, ground-swirl patterns (cycloidal marks), radar tracking, eyewitness testimonies, media reports and damage imagery, as well as photogrammetry/videogrammetry if video is available.
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A scale of wind damage intensity in which wind speeds are inferred from an analysis of wind damage: F0 (weak): 40- 72 mph, light damage.
F1 (weak): 73-112 mph, moderate damage. F2 (strong): 113-157 mph, considerable damage. F3 (strong): 158-206 mph, severe damage. F4 (violent): 207-260 mph, devastating damage. F5 (violent): 261-318 mph, (rare) incredible damage.
All tornadoes , and most other severe local windstorms, are assigned a single number from this scale according to the most intense damage caused by the storm.