FARMERSBURG, Ind. (WTWO/WAWV) – We owe much to the late Dr. Ted Fujita. His scale for classifying the strength of a tornado is still used today, more than 50 years after it’s introduction. He is responsible for saving hundreds of thousands of lives through the discovery of microbursts—a breakthrough that helped transform airline safety.
Fujita died in 1998 and is the “F” in the F0 to F5 scale. The Enhanced Fujita Scale or EF Scale, became operational on February 1, 2007.
An EF 0 tornado is minor with winds of 65 to 86 miles an hour. Power outages, damage to gutters and siding, shingles peeled off and large branches broken off can be expected.
An EF 1 causes moderate damage. Poles toppled, small trees uprooted, broken windows and significant roof damage caused by winds of 86 to 110 mph.
An EF 2 causes considerable damage with winds of 111 to 135 mph. Most poles knocked over, cars can be flipped, larger trees uprooted and roofs blown off.
An EF 3 is severe with winds of 136 to 165 miles an hour. A high-end EF 3 is what moved from Crawford County, Illinois through the city of Sullivan and into Owen County. Eight killed and many homes destroyed, millions in damage. Most standing objects demolished, vehicles displaced, bark stripped from trees and entire floors destroyed.
An EF 4 is extreme with winds of 165 to 200 mph. Much of the landscape stripped, most homes leveled and cars thrown into the air.
An EF 5 is incredible. Winds 201 miles an hour and higher. Grass can be ripped from the ground, homes completely swept away and even concrete ripped from the ground.
While hurricanes can cause damage to a wide area, tornadoes pack the most destructive winds on the planet.
Courtesy of Chief Meteorologist Jesse Walker, AMS/NWA: Most tornadoes are considered weak with just over one-hafl being EF0. EF0 – EF2 make up the majority of tornadoes. About 96%-97% are rated EF0-EF2. EF3 tornadoes are much more rare with only about 2-3% being EF3. EF4 is even more rare with only about 0.5% being EF4. EF5 are extremely rare. Less than 0.1%. Last EF5 in the U.S. was 10 years ago. May of 2013 in Oklahoma. Last EF5 in Illinois was in August of 1990 and last in Indiana was in April 1974. About the biggest we ever see in the Wabash Valley are one-half mile wide. The Easter Sunday tornado in March 1913 that hit Terre Haute was one-half mile wide and was an F4. Largest tornado ever recorded was in Oklahoma in 2013 and was 2.6 miles wide.
From the National Weather Service. The EF Scale was revised from the original Fujita Scale to reflect better examinations of tornado damage surveys so as to align wind speeds more closely with associated storm damage. The new scale has to do with how most structures are designed.
EF SCALE
EF Rating 3 Second Gust (mph)
0 65-85
1 86-110
2 111-135
3 136-165
4 166-200
5 Over 200
*** IMPORTANT NOTE ABOUT EF SCALE WINDS: The EF scale still is a set of wind estimates (not measurements) based on damage. Its uses three-second gusts estimated at the point of damage based on a judgment of 8 levels of damage to the 28 indicators listed below. These estimates vary with height and exposure. Important: The 3 second gust is not the same wind as in standard surface observations. Standard measurements are taken by weather stations in open exposures, using a directly measured, “one minute mile” speed.
Assigning a Tornado Rating Using the EF Scale
The NWS is the only federal agency with authority to provide ‘official’ tornado EF Scale ratings. The goal is assign an EF Scale category based on the highest wind speed that occurred within the damage path. First, trained NWS personnel will identify the appropriate damage indicator (DI) [Notes:see list below] from more than one of the 28 used in rating the damage. The construction or description of a building should match the DI being considered, and the observed damage should match one of the 8 degrees of damage (DOD) used by the scale. The tornado evaluator will then make a judgment within the range of upper and lower bound wind speeds, as to whether the wind speed to cause the damage is higher or lower than the expected value for the particular DOD. This is done for several structures not just one, before a final EF rating is determined.)
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