April 24, 1993 Killer Tornado in Tulsa, Oklahoma

April 24, 1993

The Killer Tornado in Tulsa, Oklahoma

Click on the image for a larger view.

The lower set of images were greatly enhanced using unsharp mask to increase detail in an otherwise low contrast tornado image.

Al Moller, his friend Patty and my youngest son Scott had just pulled into a Pizza Hut to make a badly needed "pit stop". An outflow boundary was pushing south toward what we thought was a fairly weak updraft to our southwest. (Al had commented earlier that he thought the rain free base might be weakly rotating, as we passed north and northeast of it on the interstate in northern Tulsa. At the time, we were focused on a severe thunderstorm north of Tulsa.) Inflow was fairly strong, about 20 to 25 mph. As we got out of the car, I could see scud forming quickly a few miles to our WNW.

While walking into the Pizza Hut, I assumed that the rapidly forming scud was on the leading edge of an intense outflow boundary that was surging south from the severe storm north of Tulsa and that the outflow boundary would undercut and weaken the updraft. I commented to Al that we had to make it fast and get back on the road before the gust front, rain and hail hit.

We had encountered light hail earlier as we passed through the transparent precip core, northeast of the "weak updraft". We had turned south at the truck stop that was soon to be devastated by the tornado! Al and I had both assumed that we had caught up to the complex late in its evolution and the storms were becoming outflow dominant.

Back to the Pizza Hut. The restroom was small and would only accommodate one person at a time. I was last.

Al immediately went back outside to check the progress of the storm, but within seconds he returned and began beating on the restroom door, yelling "TORNADO! TORNADO! TORNADO FORMING NORTHWEST! WE'VE GOT TO GET OUT OF HERE QUICK!" He then ran back outside. Through the door, I could hear the muffled, but excited comments of customers as Al's message started sinking in.

When I exited the restroom, the Pizza Hut customers and employees were all wide eyed, standing up, alternately looking at me and each other. A few rushed to the windows. One or two started toward the door wanting to know more, as I ran outside. When I emerged from the building, I was confronted by rapidly rotating scud clouds under a dark ragged round base located about 1/2 mile to our NW. Inflow was tremendous and had increased to 30 to 40 mph, with higher gusts. Fortunately, although at the time I had not yet perceived it, the storm and the developing tornado was again moving NE and not towards us, even though it had been shoved south by its initial encounter with the outflow boundary. (The inflow had apparently increased and balanced the force of the outflow as the mesocyclone and its associated updraft exploded above.)

I immediately checked into the local SKYWARN net and reported what we saw as we left the parking lot and drove east, back toward the interstate. It was 1/2 to 3/4 of a mile back to the southbound entrance ramp to the same N/S interstate that led to the soon to be devastated truck stop. An inflow jet had developed and was kicking up dust, paper, leaves and other small debris, pulling it all rapidly northward into the tornado. The core of the inflow jet was only 100 yards or so east, just on the other side of the interstate.

Al intensely studied our precarious situation and judged that we could safely stop. I pulled up on the grass at the side of the entrance ramp to the southbound side of the interstate, so we could quickly escape if necessary. As soon as I stopped the car, Al jumped out with his camera. I sat in the car with the motor running, rolled down the window and took a quick sequence of photographs as the tornado developed fully a mile or so to our north. Patty and Scott watched nervously from inside the car.

We didn't know it at the time, but this was when the tornado devastated the truck stop we had passed earlier and killed more than a dozen people. Many of those killed were motorists driving down the interstate. Several victims had abandoned their cars and sought refuge in roadside ditches, only to be crushed underneath their cars and other debris that was blown on top of them by the tornado.

A thick curtain of precipitation wrapped around the south side of the mesocyclone, obscuring the tornado. We drove up the entrance ramp, intent on finding an east road that would let us get ahead of the tornado. It was about this time that we heard a report over the SKYWARN net that a used car lot and a church 1/2 mile north-northwest of the Pizza Hut had received moderate damage. Several minutes later, the local SKYWARN spotters began reporting the devastation at the truck stop.

Looking NNE, RFD and wrap around precipitation obscured our view of the tornado.

Our intended path to the east was blocked due to the river east of Tulsa and south of the interstate, there were no bridges to cross over the river. We were forced to go several miles north to the interstate several miles east of the carnage at the truck stop. Ten or fifteen miles east of Tulsa, we penetrated the wrap around precip west of the meso, but large hail forced us to end the chase. We never saw the tornado again.

We drove through another tornado's damage track farther south and skirted a third tornadic thunderstorm in southeastern Oklahoma after dark.

Later in the evening, as reality started to sink in, we were both taken aback because we, both experienced chasers, had not anticipated the rapid development that occurred as a result of the outflow boundary intensifying convergence under the updraft.

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