Introduced by the National Weather Service in February 2006, and first put into use on February 1, 2007, the Enhanced Fujita Scale (EFS) was created to better reflect actual damages recorded since the original Fujita Scale was developed. Meteorologists have recently concluded that structures could be damaged by tornadic winds that were slower than previously thought. The original scale, which was felt to be too general, did not take into careful enough account the different types of construction, and it was hard to evaluate tornadoes that struck in lowpopulated areas where not many structures were present. The new scale also offers more detailed descriptions of potential damages by using 28 Damage Indicators that describe building types, structures, and vegetation, accompanied by a Degrees of Damage scale. Otherwise, the EFS uses the same categories, ranking tornadoes from 0 up to 5.
The strength of a tornado is rated on the Fujita-Pearson Tornado Intensity Scale, which takes into account wind speeds and damage created by the twister.
||Wind Speed (mph/kph)
||Tree branches break off, trees with shallow roots fall over; house siding and gutters damaged; some roof shingles peel off or other minor roof damage.
||Mobile homes overturned; doors, windows, and glass broken; severe damage to roofs.
||Large tree trunks split and big trees fall over; mobile homes destroyed, and homes on foundations are shifted; cars lifted off the ground; roofs torn off; some lighter objects thrown at the speed of missiles.
||Trees broken and debarked; mobile homes completely destroyed and houses on foundations loose stories, and buildings with weaker foundations are lifted and blown distances; commerical buildings such as shopping malls are severely damaged; heavy cars are thrown and trains are tipped over.
||Frame houses leveled; cars thrown long distances; larger objects become dangerous projectiles.
||Homes are completely destroyed and even steelreinforced buildings are severely damaged; objects the size of cars are thrown distances of 300 feet (90 meters) or more. Total devastation.