If a tornado hits a cornfield and does not hit a building, it is almost impossible to rate it higher than an EF0 or EF1, even if the wind speeds were theoretically 200 mph. Because there is no "damage indicator" to prove the intensity, the rating remains low. This is why the strongest tornadoes are often those that hit urban areas where the damage is observable.
While the USA uses the Enhanced Fujita Scale, other regions use different systems: tornado ranking system
Tornadoes are often also measured by their physical dimensions using the , though this is less common than intensity ratings: If a tornado hits a cornfield and does
It is a common misconception that a machine measured the wind speed. The wind speeds in the EF scale are . When you see a news report saying "The tornado had 170 mph winds," they usually mean "The damage suggests the winds were around 170 mph." While the USA uses the Enhanced Fujita Scale,
In 2007, the was implemented. It retained the same 0-to-5 ranking system but refined the wind speed estimates and, crucially, introduced standardized "Damage Indicators."
