Enhancing the Fujita Scale

Upon the completion of my entry level internship with the National Weather Service in Milwaukee, I was assigned to be the program leader for severe weather preparedness in Indianapolis in April 1976. My first task was to pour through a stack of newspapers about a foot high to determine the storm track and intensity of seventeen tornadoes that occurred in Indiana in March.

My assessments were based on field reports from observers and emergency managers, communicated via the print media. The Fujita-Pearson scale was developed in 1971 and my job was to determine the tornado's intensity, along with a path length and width for historical documentation. The storm data report also encompassed a narrative of the damage and an estimated dollar loss.

Allan Pearson, the Director of the Severe Storm Center at the time, worked with Dr. Ted Fujita to create this rating scale. This scale was updated by a collective group of individuals to define the intensity based on actual assessment of property damage. There are currently 28 indicators that can be used to estimate a tornado's wind speed.

Original work done by Dr. Fujita

In May of 1999, I was part of the NOAA assessment team following the devastating tornadoes in Oklahoma and southern Kansas. I have personally seen the damage caused by an F5 tornado, where cars were wrapped around trees and in some cases pavement and sod stripped from the earth's surface.

Earlier this spring I sat in on a presentation by Tim Marshall, who was on the team to devise the Enhanced Fujita Scale. Tim suggested in his seminar that Dr. Fujita, prior to his death, knew the scale needed some re-evaluation.

Enhanced Fujita Scale and damage indicators

CE