FAYETTEVILLE, Ark. (KNWA/KFTA) — April 10, 1929, was the day the only documented F5 tornado occurred in Arkansas. It stretched from southern Batesville to north of Swifton and southern Alicia. How are tornadoes rated, and why haven’t we seen any in Arkansas in such a long time?
The Fujita and Enhanced Fujita Scale
The Fujita scale, created in 1971 by Dr. Ted Fujita and first used in 1973 by the National Weather Service, was used to classify tornadoes based on wind speeds. Through several years of rating tornadoes, it became clear that tornadoes couldn’t be rated on wind speeds alone. For better rating accuracy, they introduced the Enhanced Fujita Scale on February 1, 2007. This takes the damage into account. This method is also better because as you get farther from a radar, the wind speed measured will be higher in the storm.
How does a tornado get its rating?
First, someone from the local National Weather Service office will identify the correct Damage Indicator (DI) from a list of 28 indicators based on the damage they see. Once they choose that, they pick one of the 8 Degrees of Damage (DOD) on the scale. The person evaluating the damage will then judge if the damage is within the upper and lower bounds of the wind speeds associated with the DOD. They go around to many structures in the path and then give it an official rating.
Damage Indicators
While the tornado rating is based on the damage it does, the damage indicators correspond to wind speeds given in the table above.
Example Rating …