SURFACE: Southerly winds howling out of the south 20-30mph sustained and gusty would develop in response to a very vigorous surface low rapidly getting wound up in Kansas/Nebraska. 70F+ degree dewpoints were advecting north rapidly in response to surface and low level jets cranking up. Combine this with hot temperature from mid 90's to near 100F expected along with cooling mid level temperatures from -8 to -10C at 500mb and the CAPE would be very high exceeding 5000. In fact, SW Oklahoma temperatures soared to near 110F at Altus that day. This is critical in the fact that these extremely hot temperatures would be advected N and NE up into Central Oklahoma adding fuel to the fire. I believe this to have been a major factor in the severity of these storms. For convergence, a sharp dryline would develop from the eastern Texas Panhandle and punch into western Oklahoma. We had a dickens of a time finding the dryline that day until storms started firing up along it. Surface obs were not giving us a clear indication as to where it was at. In fact, it was in the process of mixing eastward and finally started becoming more defined near Elk City at about 3:00pm. It was impossible to tell by the clouds as there were alot of elevated "popcorn" type towers everywhere due to the upper level disturbance coming in.
UPPER LEVELS: : The ETA was progging a moderate 700mb shortwave to approach Central Oklahoma later in the afternoon and evening with good vertical velocities. The AVN agreed, but a tad slower and a bit weaker. In watching the water vapor loop that morning and taking into consideration the active southern stream this year, I leaned towards the ETA. I also expected some slight cooling of the mid levels around 500mb nearing -10 according to that morning's analysis. The cap would strengthen some with warming in the layer up to 700mb level, but with the strong dryline convergence and approaching upper level energy, I expected it to break by late afternoon. Also, a 500mb jet of about 50 knots was approaching W. Texas and would nose NE into western Oklahoma. This was not initialized very well by the models. It was evident on the water vapor loop that morning and the EPZ sounding caught it. We verified this at about 1:00pm through profiler data. The Jayton and Vici profilers were starting to indicate some directional shear in addition to picking up the 500mb jet streak. The models were trying to keep the profile mostly unidirectional. I had thought that with such an intense surface low in Kansas and the winds backing to the SW at 700mb in response to the shortwave, the directional and speed shear would set up nicely. Although the 700mb winds were weak to start with, they were starting to pick up at 1:00pm in addition to some indication of backing to the SW. In reviewing the profilers after the chase, we noticed that the profilers went nuts about 4:00pm with picture perfect speed and directional shear. It was very awesome to look at. At 250mb, a jet was screaming along at about 100 knots from the WSW to W. 500mb was WSW to SW at 50-60 knots, 700mb SSW to SW at about 40-50 knots, 850mb at about 35-40 knots out of the south. Then throw in 25-30 knot S to SSE surface winds....awesome. Temps were cooling slightly at 500mb and nearing -10C. With surface temps near and above 100F, it was a powder keg waiting to explode.
SUMMARY: We picked western Oklahoma to start our chase as we expected a big collision between the dryline bulge, 500mb jet punching into the area, approaching 700mb shortwave, ideal vertical wind profiles, cooling mid levels, and deeper moisture along with the hot surface temperatures that had been persistent in SW Oklahoma. By 1:00pm when we did our final analysis from Vernon, Texas, we were getting very excited as everything was coming together. We became more confident of the target area...western Oklahoma. Again, I'll note the extremely hot temps in SW Oklahoma with temps around 110F. The powder keg had been lit.
DATA: 5:00pm (2200Z) - ARPS data for the area near Oklahoma City indicated CAPEs well over 5000; LI of -11 to -14; BRN of 100; BRN SHR of 12 to 14; tight THETA-E Ridge across western half of OK with max of 365 near OKC; excellent moisture convergence across west-central OK; and strong UVV (Upward Vertical Velocity) across west-central OK ahead of shortwave and obvious drypunch into W and NW Oklahoma. Check out the Purcell wind profiler for a beautiful and perfect wind profile.
I drove over to Blair Kooistra's house, loaded up his vehicle and we were off. He too was expecting the same area and we discussed the moderate risk for Kansas. We thought that if things didn't materialize as hoped, we would be close enough to Kansas to adjust our chase plan.
We headed up 287 out of Fort Worth towards Vernon. We got there around 12:30 and after finding a place to hook up, we began analyzing the 1:00pm data. We really liked what we were seeing! Temps were soaring in SW Oklahoma and already busting 100 at Childress and Altus. The 500mb jet was nosing towards western Oklahoma quite nicely as was the slight drop in mid level temps. The 250mb jet was screaming from the west at 100-110 knots as well. The moisture was making excellent progress into the area with Td now near 70 advecting into the target area. The wind profilers were starting to look better and already hinting at some directional shear setting up. The surface winds were really starting to pick up and intensify. We analyzed the dryline bulge setting up nicely focusing on W and NW Oklahoma. Good moisture convergence was setting up in western Oklahoma. However, the dryline was still mixing eastward along with the higher dewpoints still advecting northward....so we couldn't find a good demarcation line to peg its location. We decided that our target area was still looking good. We headed that way up 283 through Altus where we ate lunch. The bank signs said 109F and it certainly felt like it!! We noticed some turkey towers to the distant NW..the dryline we wondered? We continued on north through Mangum towards I-40.
At around 3:00pm, we arrived at I-40 and 283. By this time, elevated "popcorn" towers were going up all around us as far as we could see but nothing really getting organized. This was due to the very hot temps, cooling mid level temps and the increasing UVV ahead of the 700mb shortwave. This was encouraging as it clearly showed the instability was there. The towers were leaning and exhibiting hints of excellent shear setting up.
We then noticed two particular clouds that were looking different to the north of Elk City. The bases were getting a little broader with very compact and crisp heads. They would build up a little then get mushy producing rain showers. At this point, we continued to watch them try to build, but with little success. However, they were persistent. I was thinking that these were just some elevated showers in response to the shortwave.
We kept trying to determine where the dryline might be from listening to NWR and conversations with Blair's friend via cell phone....no clear demarcation yet. We did not know it at the time, but we were practically on top of the mixing dryline!! We stayed with these cells as we had a suspicion of the dryline being a bit further east, so we headed east on I-40 paralleling the "showers".
All of a sudden, these "showers" started gaining more vertical growth. Shortly thereafter, we heard a tornado watch issued for central and west-central Oklahoma. We were right in the middle of it on the western edge! Right after that, these "showers" had grown into severe thunderstorms with warnings going up for Custer and Blaine counties. High fives and the forbidden sacred dance of chaser merriment ensued. These storms were really starting to go nuts with each successive updraft more powerful than the one before it and in rapid succession. It was time to intercept!!!
From I-40, we took 281 north through Geary and to Greenfield. At about 5:00pm, we saw a developing wall cloud to our NNE by about 5 miles. The anvil was really well defined and crisp. Taking into consideration some right turning, we took off east along a dirt/gravel road. The wall cloud continued to organize and rotation was evident (no need for the scanners and radios now!). We went a few miles to the east keeping up with it until we found a nice clearing through the trees. There, we setup to video and get some stills of a nice rotating wall cloud. It was at this time that my severe SDS broke because I started to become rather giddy, light headed, dizzy, rapid breathing, racing pulse, and total elation.
We watched the wall cloud continue to rotate and organize. Seeing that it was picking up forward motion, we decided to try and find Highway 33 so we could keep up with it. Just as we started heading out, I looked over my shoulder and noticed this red column of dust rising towards the wall cloud....tornado #1. Just as I started babbling and pointing over my shoulder, Blair quickly picked up on it and scrambled for his video camera. He bailed out while I pulled off the road. He got some great video of this dust cloud rising up as a column into the center of the wall cloud. The touchdown was brief and fairly close about 1/2 mile away to our NNE. It started moving on, so did we.
After some very tricky navigation and a wrong turn (the county roads in Oklahoma have no signs and all look alike), we finally found Hwy 33 just east of Watonga. We soon caught up to the back edge of the storm just south of Omega. We saw a white funnel cloud which was just roping out. The storm had gained some distance on us, but we were on an excellent intercept path. We came into Kingfisher where the tornado sirens were blaring.
Coming out of Kingfisher, we could see that the storm had weakened some in the updraft area, but towers were continuing to try and build. We caught up to it and got right under the new updraft region near the Kingfisher/Logan county line. I saw the updraft region reorganizing with strong updrafts erupting. We were just to the NW of this new development at this time. The winds shifted several times as the inflow/outflow was duking it out for supremacy. The clouds were boiling and churning overhead. I told Blair that I thought this beast was going to come to life again.
The outflow finally won out and shoved to the SE. Just about the time it reached the new updraft, a wall cloud quickly formed and began to organize exhibiting some rotation. It was quite a treat to watch the whole process from the very start. The wall cloud started growing a tail cloud and a nice inflow band quickly established itself. This thing was going nuts! This is where we saw a truly amazing sight.
The updraft core was clearly visible as it rose vertically as a separate cylindrical cumulus cloud then tilted over horizontally wrapping around the meso and disappearing into the updraft. Blair described it best as it looking like a drier vent hose wrapping around the meso base. I strongly believe this to be the horizontal vorticity roll column in the process of being stretched and pulled into the meso. We got some great stills and video of this. It was truly amazing.
We watched as a new RFD started approaching the wall cloud from the north. When it collided with the wall cloud, rotation quickly increased, became organized, rapidly intensified and grew producing a funnel cloud. We followed it a little ways on 33 to near Twin Lakes. This wall cloud was really amazing as it started evolving and moving northward away from the general storm motion...a bit unusual. I believe that the precipitation core suddenly intensified creating an RFD/gust front that stretched/pushed the updraft to the WNW side of the storm with the storm moving east.
As we got closer to the Hwy. 33/74 intersection, the wall cloud was really rotating pretty rapidly producing brief little needle funnels. The meso itself was rotating quite nicely as well. All of a sudden, we looked up and saw a long funnel cloud extending horizontally out of the upper side of the wall cloud/meso rotating about a horizontal plane and horizontal axis. It was wriggling around like a snake and persisted for at least a couple of minutes. Absolutely incredible!!!
Soon after this, the rotation in the wall cloud became better concentrated and was rotating more rapidly. A funnel cloud started forming and extended outward at an angle pointing to the NW away from the precip core (keep in mind that the storm is moving east). We watched the funnel dance and gyrate while it slowly continued growing. The funnel continued extending towards the ground and made contact about 2 miles NW of Guthrie....tornado #2. It roped out after about 10 minutes as the updraft was finally stretched out and cut off. Another wall cloud was already forming to the SE.
We quickly loaded up and headed out to catch it. We passed through Guthrie as we watched another loosely organized wall cloud that formed and hung to the NNE of Guthrie. It quickly fizzled out and another new wall cloud was rapidly organizing to the SE on the SE quadrant of the storm...where it should be. It was at this time that the thick mammatus filled anvil from a different supercell further to the WSW started "seeding" the updraft area with anvil precip as well as putting a lid on it. We just got to I-35 as I started thinking this storm was going to die pretty quick. At this point, we should have pulled off right then and headed south to intercept the storm approaching OKC. That 10 minute indecision made a difference, but didn't hurt us. We followed the remaining updraft/meso until it quickly decayed.
We did an immediate 180 degree turn to intercept the other storm approaching from the SW. Looking over our shoulder as we were headed south on I-35, we saw the updraft finally die. This would have normally been a great chase but it was yet to reach its climax. Another huge tornadic cell beckoned us to the SW.
We spied the perfect spot, A Love's Gas Station near the 44/35 merge by Frontier City. Expediency was of the highest necessity as the main precip core along with baseball sized hail was too close for comfort and bearing down on us. I whipped up to the nearest pump while Blair raced inside and I pumped. It was like a Richard Petty pit crew in action!! I was warning folks outside while Blair was trying to warn folks inside. He told the girl at the counter of the impending danger as the TVS trajectory was targeted on this area. Her lackadaisical reply was, "Well, it's gonna hit where it's gonna hit I guess". She would find out later it would hit them. I hope she was able to find shelter. Most people I had warned seemed to take an indifferent attitude as if we were crying wolf. I couldn't believe it. They certainly would receive a heavy handed slap from reality shortly. Complacency certainly is a leading cause of fatalities in this country.
We certainly had sense enough to continue high-tailing it south on I-35. We soon encountered part of the precip core with a couple of spatterings of mushy nickel hail. We were just a bit apprehensive as we knew large hail was very close to us and a tornado was just on the other side. We soon cleared the precip and saw this breathtaking and humongous meso to our SW about near Yukon. The best that I can estimate is that the meso base was at least 6 miles wide with a wall cloud/area of organized rotation of close to 2 miles wide. A large lump formed in my throat and the adrenaline shot through me like a jolt of electricity. This was one of the biggest mesos I have ever seen in person as well as the most beautiful. It was definitely a religious experience! Blair and I both were totally speechless. I experienced totally elation and exhilaration but at the same time a deep feeling of dread as I realized this monster was bearing down on OKC. A thing of awe and beauty now took on a dark and sinister appearance as it's deadly threat focused on Oklahoma City. The time is about 7:30pm.
We were scrambling for a good place to setup and view this beast. Blair pointed out an excellent spot on the east side of I-35 near the 44/35 split and Remington Park on the eastern side of OKC. The whole sky seemed to be rotating as we watched the beautifully striated meso slowly churn over OKC. It looked like a scene out of Independence Day with this huge spaceship hovering over the city. I expected at any time a swarm of fighter jets from Tinker AFB to attack it. The storm had a very broad area of organized rotation at its center with many needle funnels dancing around the slightly lowering center...the wall cloud. We thought we were about to see a horrifying nightmare unfold before us with a large wedge plowing through OKC.
It was at this time a brief tornado/waterspout touched down at Lake Hefner. There was little in the way of any visible funnel, but we did catch on video a rotating debris cloud kicking up....tornado #3. The rotation eased up slightly, but still organized. Shortly thereafter, another faint debris cloud kicked up again as it briefly touched down in The Village area knocking down a radio tower and producing F1 damage to some homes and a church....tornado #4. After this, the wall cloud's rotation eased up some and raised more into the meso. However, I noticed a new RFD rapidly rushing toward it from the northwest as evidenced by some scud clouds. We grew very tense as we knew what was about to happen....intensification. I was horrified as I knew Edmond lay in its path.
We decided to quickly move about a mile to the south as we were too close to its path. We watched the RFD protrude into the center of the meso which quickly intensified the rotation. A new wall cloud formed and began lowering much more than the previous ones. The rotation rapidly became more organized and began to significantly increase. We had just setup the cameras when we noticed this separate lowering on the nose of the RFD with slight rotation bearing down rapidly on us from the NW. Blair didn't wait for me to say anything. Fearing a periphery rope tornado, we made a very hasty retreat to the south about a 1/4 mile until the threat dissipated.
We quickly setup again as we watched the well organized wall cloud begin to form a funnel. You could see the RFD notch starting to cut in quite clearly. The funnel lowered and touched down near Frontier City, across I-35 and into a small subdivision sending debris into the air causing F2 damage....tornado #5. It lifted again as it passed Arcadia Lake but the tornadic circulation itself was still on the ground. The huge wall cloud continued lowering and was almost on the ground. We thought it was about to wedge which it never did. We were paralleling it on Hwy. 62 watching it become more rain wrapped and slowly disappearing from sight. At this time, we noticed 2 news helicopters overhead hovering near the base of the meso adding to the atmosphere. We stayed with it on 62 in case another area of tornadogenesis developed to the E or SE of that.
The visibility was getting poor as was the road network. We tried to cut north, but soon decided to try and catch a third supercell approaching SW parts of OKC which was exhibiting a TVS. It was moving fast and cut off our attempt to intercept from the east. We decided to go around the north of it skirting the anvil precip along I-40 to the north of Tinker AFB. We encountered very strong outflow of at least 50mph blasting the chase vehicle broadside. We eventually got around the backside of it heading south on I-44. We soon decided to end the pursuit as the third storm began weakening and daylight had run out. We watched some lightning in the storm's last attempt of intensification with new updrafts. After nearly 7 hours straight, we could finally relax. The chase is over. We headed down to Norman where we got a room, ordered a victory pizza meal from Dominos and reviewed the video and watched TV news coverage. I got very little sleep that night as the adrenaline was still running through my veins. Definitely a lifetime chase to remember.
The one thing that really disturbs me is the lackadaisical attitude by the general public regarding weather warnings...especially tornado warnings. This could have been a major disaster. Most everybody we pleaded with to find shelter skoffed at us. An amusement park of over 500 people got a glancing blow by the tornado. With severe storms and tornadoes in the area for a couple of hours with another storm bearing down on them, park officials did nothing until the actual tornado was bearing down on them. (I have been told by a park employee that was there that in fact an announcement was made over the PA system about 10-20 minutes earlier). This was definitely a very scary storm and painfully obvious it wasn't a bird-fart thundershower. Even without hearing any warnings, just looking at the sky told you a vicious storm was approaching. With every TV and radio station pleading with everyone to take shelter, why did park officials or even patrons wait until the last minute? They were all rushed into a building/hall just seconds before the tornado struck....reportedly 500 people crammed in. If the tornado had been more powerful and hit that building directly, catastrophic loss of life would surely have occurred.
That's it for my report. Feel free to contact me. txt@gte.net
