By Margo Waldrop
Tornadoes come in all strengths and sizes, from small dusters to one mile long monsters. Their damage can be extensive and varied. In 1971 Tetsuya Theodore Fujita of the University of Chicago, invented a scale to measure tornadoes based on the extent of damage they produced. The scale measures wind forces required to destroy homes and buildings and ranged from F0 (smaller twisters) to F5 (larger twisters).
In recent years, an Enhanced Fujita Scale was devised by engineers and meteorologists to more accurately determine a tornadoes wind speed and ability for destruction. This enhanced scale now details damage for 23 specific types of buildings such as mobile homes, homes, and schools. It also includes destruction parameters for additional objects such as trees, power poles and cell towers.
Enhanced Fujita Scale Ratings:
- EF-0: Wind speeds between 65 and 85 mph. Light structural damage including surface peel to roofs and broken tree branches.
- EF-1: Wind speeds between 86 and 110 mph. Moderate structural damage. Stripped roofs, overturned mobile homes and cars.
- EF-2: Wind speeds between 111 and 135 mph. Considerable structural damage. Complete loss of roofs, shifting foundations, cars and mobile homes destroyed. Uprooted or snapped trees.
- EF-3: Wind speeds between 136 and 165 mph. Severe structural damage. Weak structures blown from foundations, large buildings severely damaged.
- EF-4: Wind speeds between 166 and 200 mph. Devastating damage. Homes completely leveled, cars turned into missiles.
- EF-5: Wind speeds over 200 mph. Incredible damage. Strong framed homes leveled from foundations. High rise buildings with significant structural damage. Cars thrown through air as high as 109 yards.
The purpose of the Fujita scale is to help people better prepare for tornadoes, and to enhance the strength of buildings, homes and even storm shelters. This knowledge helps to build structures that are better able to withstand the intensity of tornadoes.