INTERVIEW: Weather Channel’s Gregory S. Forbes remembers his mentor, Dr. Fujita, namesake of F-scale
Photo: Dr. Tetsuya Theodore Fujita had a unique vision for using any and all available technology to gather detailed data. Photo courtesy of © Roger Tully / Provided by PBS Pressroom with permission.
The Fujita scale, otherwise known as the F-scale, is a tornado classification system that has helped scientists, government officials and, perhaps most importantly, individuals living in high-risk areas to gauge the dangers that crop up from these often-deadly storms. The F-scale was the brainchild of Dr. Tetsuya Theodore Fujita, a Japanese-American scientist who is the subject of a new episode of American Experience on PBS.
Mr. Tornado is set to premiere on the network Tuesday, May 19 at 9 p.m. On the one-hour program, Fujita’s advancements in the field of meteorology will be held under the microscope. Audience members will see the career trajectory that took the scientist from his study of atomic blasts to the deconstruction of tornadoes — two monsters of a different breed.
After studying the devastation wrought by the atomic bombs dropped on Hiroshima and Nagasaki, Japan, Fujita headed for the University of Chicago for further research, according to press notes. At the research institution, he studied under Dr. Horace Byers, head of the Thunderstorm Project.
The TV special looks at the many highlights and challenges of his career, including a seminal moment in 1974 when he studied the many tornadoes that cropped up over a two-day period in what is known as a super-outbreak. Another aspect of the documentary involves the 1975 crash of Eastern Airlines Flight 66 and Fujita’s theories about its mysterious demise.
One of the voices in the documentary, and one of the voices who knew Fujita’s work and influence best, is Gregory S. Forbes, longtime severe weather expert for The Weather Channel. Forbes actually studied tornadoes and severe thunderstorms under Fujita’s advisement at the University of Chicago.
Recently Hollywood Soapbox exchanged emails with Forbes about the continuing impact of Fujita’s tornado work. Questions and answers have been slightly edited for style.
What are your memories of working with Dr. Fujita at the University of Chicago?
I have a great many memories. Most fundamental was the exciting chance to work with such a great meteorologist. Almost every day he would come to the office, set down the materials he had brought in from home, and then call me to his office to show me what he had worked on the night before. He would ask for my reactions and feedback on his research.
Following the 1974 super-outbreak and in subsequent years I got to go on a number of tornado damage survey trips with him, flying in Cessna aircraft, National Guard helicopter, and by car. He and I worked closely together in documenting the super-outbreak tornadoes and performing research on them. I flew with him on Learjet missions to monitor the behavior of thunderstorm tops while severe weather was in progress below. I helped him set up the first research project on downbursts and microbursts — NIMROD in northern Illinois — while I was a post-doctoral research associate. I had great experiences!
How monumental of an advancement was the F-Scale?
This was a tremendous improvement in our ability to assess risk from tornadoes. Prior to the F-Scale, it was just the number of tornadoes that were counted, along with their path lengths and path widths (as best as they could be determined). But some tornadoes were weak and caused little damage, while others destroyed large parts of communities. The development of the F-Scale and then its operational use by the Weather Bureau and National Weather Service has allowed us to know how frequent tornadoes are of various intensities.
What’s the main difference between the Enhanced F-Scale and the original scale that Dr. Fujita formed?
There are two main differences. One is that the estimated wind speeds associated with EF ratings are different from those used with the original F ratings. A large amount of data collected by structural engineers over the years relating the type and extent of damage to various structures have now been used to estimate wind speeds needed to cause various EF-scale damage. Wind speeds estimated for EF3 to EF5 tornadoes are less than those of F3 to F5, but EF5 is open-ended (over 200 mph).
Second, Dr. Fujita grouped buildings, vehicles and trees together in his descriptions of damage used to assess the F-scale ratings, based upon the worst damage. Then the wind speed was estimated.
In the Enhanced Fujita Scale each type of building (e.g., mobile home, frame home, school, high-rise, etc.) and a few other objects [are] listed separately, and then the extent of damage is used to estimate the wind speed needed to cause the damage. The highest wind speed is then used to give the EF-rating. The EF-Scale damage assessment process, therefore, is more involved than for the F-Scale. F-Scale is generally possible to assess from the air, whereas details needed to assess some upper-end EF-Scale ratings can only be determined from a detailed close-up ground survey.
When did you first fall in love with the weather?
When I was in the seventh grade a teacher taught weather/meteorology as part of the science program. We drew isobars on a weather map and looked at clouds. I started watching the TV meteorologists (both Pittsburgh stations had meteorologists rather than just announcers presenting the weather). These showed me that meteorology was a legitimate science, and predictions could be made to help people plan their daily activities. I had known I wanted to be a scientist, and this convinced me that my work every day as a weather forecaster could help people.
How many tornadoes have you seen in person? What’s the experience like?
At least five. One on May 10, 2010, was rated EF3 east of Oklahoma City, Oklahoma, and was large. We saw it from probably a mile or two away. I was tracking tornadoes with Mike Bettes of The Weather Channel, and we were embedded with a tornado research project called VORTEX-2. The project started the day east of the area, and then suddenly tornadoes started to form to our west. We were racing there, seeing the storms on radar and trying to find an area to pull off that didn’t have trees so we could have an open field of view. Frustrating. Suddenly, there it was. We were able to show and report on the tornado live. It was very exciting.
Another exciting tornado sighting was east of Rozel, Kansas, on May 18, 2013. I was again tracking tornadoes with Mike Bettes. It had been a frustrating day trying to get a view of tornadoes that were hidden by rain and hail. We gave up on one storm, headed back south and caught the next storm. As we were driving, in the distance we saw a large tornado. It disappeared, and we pulled off the road near a wheat field (I believe it was) where we thought the next tornado in the family might form. We watched a tornado form about 200-300 yards east of us and tilted back aloft in a roped funnel right overhead. The whooshing noise of the tornado sounded like a waterfall. Then the rain and wind of the gust front blasted us, and the tornado was gone.
For the layperson, why do tornadoes form?
Tornadoes form when there is a combination of a strong thunderstorm having a strong updraft (inward and upward-flowing air) near the ground and strong wind shear (wind varying strongly vertically and/or laterally) that gets caught up in and concentrated by that updraft. In the extreme cases, the whole thunderstorm updraft is usually rotating, forming what we call a supercell thunderstorm. Strong, long-lived tornadoes often form beneath these strongly rotating thunderstorms. These favorable conditions and strong tornadoes usually form in warm, moist (unstable) air as a disturbance in the upper-level jet stream approaches.
Do you feel that the research of Dr. Fujita is still pertinent in 2020?
Dr. Fujita’s research is still very much pertinent today in many ways. Some of his earliest studies of the Fargo, North Dakota, tornado of 1957 revealed thunderstorm structure and features which he named that are still in use today (e.g., wall cloud, collar cloud, tail cloud). His studies of tornado damage patterns suggested that tornadoes often have a substructure, sometimes in the form of vortices — tornadoes within the tornado — that we call suction vortices. Videos now frequently show these.
His Fujita Scale has been modified to the Enhanced Fujita Scale that is still used. His discovery of narrow, intense thunderstorm downdrafts called microbursts led to tremendous advances in aviation safety. Microbursts had caused hundreds of deaths from crashes of commercial aircraft in the U.S. from 1975-1985. His discovery led to research programs to detect them using radar and surface instruments, and these detection tools were then put into operation. Pilots still receive microburst detection, avoidance and recovery training. He taught us severe storm meteorology fundamentals that research still builds upon.
By John Soltes / Publisher / John@HollywoodSoapbox.com
Mr. Tornado, a new episode of American Experience, will air Tuesday, May 19 at 9 p.m. Click here for more information.
