Q. How is the strength of a tornado determined?
A. The most common and practical way to determine the strength of a tornado is to look at the damage it caused. From the damage the wind speeds can be estimated. An “Enhanced Fujita Scale” was implemented by the National Weather Service in 2007 to rate tornadoes in a more consistent and accurate manner. The EF-Scale takes into account more variables than the original Fujita Scale (F-Scale) when assigning a wind speed rating to a tornado, incorporating 28 damage indicators such as building type, structures and trees. For each damage indicator, there are eight degrees of damage ranging from the beginning of visible damage to complete destruction of the damage indicator. The original F-Scale did not take these details into account. The original F-Scale historical database will not change. An F5 tornado rated years ago is still an F5, but the wind speed associated with the tornado may have been somewhat less than previously estimated.