Storms – Pathfinder


John M. Wylie II, Editor and Publisher


Locally, the events of April 26, 1991 are referred to as the Oologah Tornado. But a retrospective by the National Weather Service notes that the storm system was one of the most powerful and widespread on record, affecting dozens of communities. The NWS calls the event the Plains Tornado Outbreak.

The date is also significant because it was the first real test of the Pathfinder radar system, which used computers instead of grease pencils and rulers to project the path of tornadoes and project time of impact for affected communities.

While taken for granted by those 25 and younger, Pathfinder was a remarkable achievement back in 1991 and is widely credited for providing early warning to Oologah and saving countless lives.

The security camera at PSO captured this image of the tornado as it moved into Oologah

The Leader printed a two-week package of stories marking this significant anniversary and now offers that package online.

The first part describes the historic meteorological aspects of the storm system and the development of Pathfinder radar in the words of people who were involved.

The second part deals with the impact the storm had on a variety of residents, then and now.

This project would not have been possible without the online retrospective being produced by the National Weather Service offices in Tulsa, Wichita and Norman and the NWS Storm Prediction Center. Karen Hatfield, a forecaster with the NWS Tulsa office, has provided invaluable information and allowed us to reproduce selected material from the site. She allowed us advance access to the site, which should be “live” in a few days.

We covered these storms and we learned a great deal from compiling this report. We hope you will, too.


David Oldham, Pathfinder inventor

By DAVID OLDHAM, Weather Nerd

I grew up in Tulsa with my junior high and high school friends, Tom Bennett and James Aydelott. The three of us were all extremely interested in weather, and we had internships at KTUL with Travis Meyer throughout high school.

When other kids were out getting in trouble late nights, we were being “weather nerds” learning how to use weather computers, work the radar, and track severe weather. The weather office even had several paper maps behind a sheet of plastic where we would plot storms by hand and estimate their tracks.

All three of us were hooked on weather after our experience with Travis.

The Idea

I had my first idea for storm-tracking software while I was a meteorology student at the University Of Oklahoma.

The idea was actually very simple in concept; rather than using a map, ruler and grease pencil to sketch out a storm’s track like I did so many times as an intern, why not program a computer to do it instantly and precisely. I originally called this idea STAT – Storm Threat Analysis and Tracking.

I approached Gary England at KWTV-9 in Oklahoma City in January of 1991 about my idea of a developing “point and click” storm tracking program. I worked on the program at home, and then would bring prototypes to the TV station where we would try it out.

The team at KWTV had considered this as a “behind the scenes” tool throughout the development, but I had a different idea. I wanted the viewers at home to able to see their own town on the screen, and the time they would be threatened by approaching storms and tornadoes.

By mid-March, the system was connected so that it could be used on-air. Only a few days later, on March 21st, we used the system live to give residents of Ada more than 20 minutes advance warning of an F3 tornado that struck their town.

To our knowledge, this was the first time anywhere that public was shown live on-air the precise time of arrival of dangerous storms in each threatened community.


While I was working on my program in Oklahoma City, I was on my own as an independent contractor.

During this time, James Aydelott was working as a weather producer for Jim Giles at KOTV-6 in Tulsa. A weather producer works mostly off-camera to prepare the maps and forecasts for presentation during the news.

In the spring of 1991, James was leaving KOTV to accept an on-air position away from Tulsa. Upon leaving, he had discussed with Jim the idea of me taking the weather producer position, as well as bringing my storm tracking program to KOTV.

In late March or early April, I had joined KOTV. I continued making improvements to the program and calibrating it for use with KOTV’s radar.

My original name for the program, STAT, was not very catchy, so the KOTV promotions team came up with the name “Pathfinder”. It was a great name, because it said exactly what the program did: find the path of the storm.

Pathfinder debuted the night of the Plains tornado outbreak, predicting the path of the Oologah tornado

 April 26 outbreak

On April 26, all of the atmospheric ingredients were in place for a major severe weather event. We were still making adjustments to Pathfinder most of that day but, by late afternoon, the system was ready.

Tom Bennett was chasing that afternoon. I remember him calling back to the weather office from near Red Rock in north central Oklahoma, on one of the first storms of the day.

He saw a monster F4 tornado that ultimately was on the ground for more than 60 miles. This confirmed to us what we had suspected, that extremely violent tornadoes were likely all evening long.

Oologah Tornado

I remember the storm that spawned the Oologah tornado when it first started developing south of Stillwater. This storm would become a cyclic supercell, going through multiple stages of intensification that each would produce a tornado. Each tornado would mature and eventually dissipate, to be followed by another cycle of tornado development.

The storm first produced an F2 tornado southeast of Stillwater, on the ground for 7 miles. The next tornado was a large, long-track, F4 tornado going through the Terlton and Westport areas, ending 32 miles away at Skiatook.

While the storm was still west of Skiatook, I remember Oologah first coming up on Pathfinder, and Jim Giles working at his best both on the air and off.

During one of the breaks in our coverage, the news director came to the studio to ask Jim if he could try not to interrupt programming. The next-to-last episode of “Dallas” was being shown that night.

To put it kindly, Jim made sure the news director would not be calling the shots about giving viewers advance warning of when they would be in danger.

We watched the storm as it continued across the Tulsa-Washington county line, and it approached Oologah. By this time of evening it was completely dark, and none of the television stations had as many storm chasers as they do today.

We could not be sure that a tornado was on the ground, but all indications on the radar showed that a violent tornado was still likely.

As the storm passed through Oologah, we slowly began to get reports that the town had been struck. This tornado would also be rated an F4, with a four-mile long path starting just west of Oologah, and ending 3 miles northeast of town. The storm eventually produced one more tornado, rated F1, near Chelsea.


It was not until the next day that we began to hear reports from our news crews of people who were watching our coverage the previous night. It was very humbling to hear so many people credit our work with saving their lives, by giving them the information they needed to protect themselves.

I continued working with Jim Giles and KOTV for eight more years. In 1996, Jim, his wife Hanna, and I went to Oologah on the fifth anniversary of the tornado. The governor had declared April 26th, 1996 as “Pathfinder Day” in recognition of our work five years earlier.

I was amazed to hear everyone’s stories of that terrible night, and to see the rebuilding that had taken place.

Creating Pathfinder was one of the most rewarding experiences of my life, and I am grateful to Jim to this day for having the faith to hire a young “weather nerd” and his computer program.

Tom Bennett, Meteorologist, The News on Six

By TOM BENNETT, Meteorologist/Senior weather producer, The News on Six

April 26, 1991. This date and anniversary is a big deal to many folks, including myself. I was still in college and was freelance chasing on that day. I was able get video of the F5 tornado earlier in the day near the town of Red Rock in North central Oklahoma. Enroute back to Channel 6, a small tornado crossed in front of my car on Oklahoma 18 northwest of Yale in Payne County. This tornado would later strengthen and hit Westport, Skiatook, and Oologah. I chose to not chase this storm, but to get my video back to the TV station for the 10 p.m. news.

This decision had a huge impact on Jim Giles’ decision to offer me a full time job at KOTV. I now live in Skiatook and have many friends who remember or were even in the tornado on that Friday evening.

Since Channel 6 debuted a new software device on this date, there was an enormous amount of attention and press following the event about KOTV and their new device “Pathfinder.”

A childhood friend, Dave Oldham wrote the software while attending OU. The program gave arrival times to towns and cities with a projection. The program was in development leading up to this event.

The decision was made to use the program as an overlay to Doppler 6 radar, which was located at that time in Sand Springs, near the KOTV tower.

Jim Giles and Tom Bennett

The tornado that later hit Skiatook and Oologah passed within five miles of the radar to the North. The debris ball could be seen in the radar data near the hook of the storm. I remember Jim Giles’ saying, “this type of an event only occurs in a metro area as tornado prone as Tulsa about once every 10 to 20 years.”

Besides Catoosa, April 24 1993, the Tulsa metro has not had a tornado rated above F3 in Tulsa County.

As a meteorologist with News on 6 still to this day some 20 years later and as the GM of Jim Giles’ Safe Rooms, I still hear from people about how much that night still keeps them awake and how they cannot believe that more people were not killed by that storm.

Especially amazing was that just 125 miles NW of Tulsa, Andover, Kan., was hit by an F5 on that same day and they lost 24 people to the storm, while only 1 person was killed in the tornado as it passed near Westport, southwest of Skiatook. No one was killed in Skiatook or Oologah.

Two ladies were killed in their car as another tornado hit north of Bartlesville, near Copan. This is the same parent storm that I had video of earlier in the day from Red Rock.

Coming full circle, I work again with Travis Meyer now and 20+ years ago. I used everything I learned from my internship with Travis while back in high school to chase on this historic date.

It was an amazing day that I hope does not occur for another 20 years.

Karen Hatfield, Forecaster, National Weather Service

By KAREN HATFIELD, Forecaster, NWS Tulsa office

Residents of the Plains states are no stranger to severe thunderstorms and tornadoes during the spring months, with April and May being the peak tornado months particularly for areas in the Southern and Central Plains region.

While the occurrence of tornadoes in Oklahoma, Kansas, or Nebraska on any given April 26th would not be surprising to most people, the areal extent and violence of the tornado outbreak on April 26th in 1991 would stun even life-long residents of the region.

On that day, tornadoes ravaged the Plains from morning until after dark, affecting areas from east Texas as far north as the Iowa/Minnesota border. Fifty-five total tornadoes developed, thirty of which were rated an F2 or greater on the Fujita scale. Unfortunately, 21 people – 17 from one storm alone – died that day as a direct result of the severe weather.

The most memorable and devastating tornadoes of the day occurred during the afternoon and evening hours across northern Oklahoma and southern Kansas.

These included the much photographed long-tracked F5 that raked across McConnell Air Force Base near Wichita and the Golden Spur Mobile Home park in Andover, Kansas, the 66-mile long F4 known as the “Red Rock” or “Billings” tornado that moved through north central Oklahoma, and the infamous Kansas Turnpike tornado near El Dorado filmed by a KSNW news crew as they sought cover beneath an overpass.

Somewhat lesser filmed and therefore, lesser-known violent tornadoes also touched down near Arkansas City, Kansas, Terlton, Oklahoma, and Oologah, Oklahoma, all three rated F4.

The Terlton tornado heavily damaged portions of Westport and Skiatook, while the Oologah tornado destroyed much of the Oologah-Talala Public School district infrastructure.

At one time, three separate F4 or F5 tornadoes – Andover, Red Rock, and Arkansas City – were on the ground simultaneously over a relatively small geographical distance.

MAP CATION: The Plains Tornado Outbreak
The National Weather Service reported 332 severe storms on April 26-27, 1991.
Tornado: 54 tornadoes F-3 or higher, 21 deaths, 313 injuries
Wind: 68 severe wind storms, 1 death, 18 injuries
Hail: 210 severe hail storms, 0 deaths, 0 injuries
Total: 332 severe storms, 22 deaths, 331 injuries

Oologah Lake Leader


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