Enhanced Fujita Scale
Developed in 1971 by Tetsuya "Ted" Fujita (1920 - 1998) "Mr. Tornado"  of the University of Chicago
The Fujita Scale is based on structural strength and engineering research done by Ted Fujita and a host of others. This research created the Fujita scale as a measurement of a tornadoes strength or intensity. Simply put, how intense would a wind have to be to move a cardboard box or to move bricks?  One questions to ask would be:  How fast or intense would the winds have to be to knock over a brick wall,? Obviously those winds would be significant.  Through extensive research the Fujita Scale was developed based on damage, not wind speeds. Based on the extent of this damage conclusions are drawn as to what the winds would likely have to be to cause that type of damage. Since two wooden structured homes can be vastly different in quality and strength, there can be some misleading conclusions from the damage. Because of this and other overly general conclusions, storm researchers came up with the Enhanced Fujita scale to better reflect a tornado’s strength. Below is the new Enhanced Fujita scale started February  2007.