Supercell near Matador TX, and Other Storms
20 Apr 9
SHORT: Intercepted briefly sculpted supercell N of Matador TX, under anvil of another storm farther W that produced a tornado that we saw, but didn’t realize was such due to distance. Observed HP merger and evolution of resulting “Pac Man.” Drove back in great light show.
After getting off shift and getting enough sleep to chase safely, I looked at a little data and called Rich, who was off and agreed to join me on what looked like a marginal shear/large CAPE setup. The target area was the outflow boundary from the morning MCS, sunny and cooking well on both sides, in NW TX. At last, the Two ChumpsTM were on the road again, brother, and ready to partake of the smorgasbord of atmospheric violence.
We left Norman shortly before 1330 CDT (1730Z) and took the I-44/US-62/US-183 zigzag to Vernon, through the cold, stratus-enshrouded outflow pool and past numerous flooded fields drainning with active runoff. [it was great to see SW OK so wet and green, for once!] While refueling with both gasoline and the usual regional snacks, a supercell already was apparent along the NW-ward curving segment of the boundary near Estelline, too distant to get to without interference from a newer storm going up to its SE.
Headed WSW out of vernon on US-70, we noticed the anvil from the southeastern “Dunlap” storm was getting rather robust, and the radar presentation looked decent with unimpeded inflow. It could have been a case where having onboard radar hurt us, in 20/20 hindsight. This was the “sucker storm” along the way to something better, and we fell for it. Naturally, had we known that, we wouldn’t have bothered.
We detoured N almost to Crowell then WSW toward Paducah to take a look, and while we measured low 70s temps in what had been its inflow region, the storm crapped out right as we got there. Hardly anything was left but fall streaks, beneath the thickening and spreading anvil of two newer supercells NW-W of Matador. The eastern of the two (Matador storm) was closer to us, very near the western segment of the old outflow boundary, all by itself (for a little while anyway) and crawling eastward very slowly in order to maximize its low level SRH on the hodograph. Sweet!
We roared W almost to Matador then NNE on FM-94 to get into the immediate inflow sector of the Matador storm. We could see it was under the thick anvil of yet another storm farther to our W, which was producing a copiously arching outflow boundary on reflectivity imagery. The western storm was the “Cedar Hill” tornado producer, despite all that outflow and unknown to us at that moment.
We saw a smooth-sided lowering from cloud base to apparent ground level way off to the WNW, under what seemed at the time to be either a very scuddy, ragged updraft base or rear-flank gust front with the “Cedar Hill” storm. We laughed at it, unable to see rotation at such distance (~15 miles), and knowing the storm was producing lots of outflow. Well, it also was producing a fat tornado, and that turned out to be one. Looking back at my phone and GPS logs, this perfectly matches one of the tornado report times.
This video capture, posted to Storm-Track by Matt Chatelain, shows what it looked like to us, but a little more distant, with some slight terrain rises and mesquite trees in the way — just enough to cast doubts. Our viewing angle and lighting were very nearly the same.
Of course, reviewing the facts post-mortem removed all doubts. Again, what’s that hindsight vision? We were driving up to the Matador storm and not taking photos of that feature far to the W, but had I bothered to stop, slap on the zoom lens quickly and shoot “just in case”, I would have had my first (very distant) tornado shot of the year.
The closer “Matador” storm beckoned, its base already visible with a bell-shaped structure above. We found a good parking spot and vantage at the entrance to the Stitch Ranch, soon joined by our forecasting colleague Jonathan Garner, then a few moments later, none other than the father of storm chasing himself, Dave Hoadley.
It was great to chat with Dave and Jon during our short time at the Stitch Ranch gates. We admired the nice structure above an elongated cyclonic shear zone at cloud base. Occasionally smaller areas of rotation would develop, but tornadogenesis never appeared imminent, despite being in an environment that didn’t seem appreciably different (except for having less outflow) than the “Cedar Hill” storm. Here’s a shot of the eastern side of the supercell, looking N up FM-94, showing the sinewy curvature of cloud banding with this storm.
Rich and I then cruised N a few miles to get closer to the occasional areas of cloud base rotation before the storm got E of FM-94 and into a gigantic road void. As we did, the bigger, faster-moving and more outflow-dominant “Cedar Hill” storm began to encroach upon and seed the hell out of the our supercell. That gave it more HP character, lowering light levels ominously, and turning it into a more prototypically North Texas MUN (mean, ugly, nasty) stormzilla. We bailed S to get back to US-70, taking one more look back through the turbulent and eerily colorful “whale’s mouth” and consigning the conjoining supercells to HP-from-hell status.
A left-mover developed in situ to the SE of the combined “Pac-Man” supercell (shot from Jon Garner), then split in its own right, the continuing left member being drawn into the forward flank of the cyclonic HP monster as we hurtled E in a thread-the-needle maneuver between them. Meanwhile, the rotation in SRM imagery got very intense and tight somewhere out there in the mesquite brush to our N and NW as we headed back to Paducah, but good luck seeing anything in the deep, dark murk!
We tried to circumnavigate the growing area of elevated nocturnal convection by driving E to SPS then N through FSI, but hit heavy rain and a barrage of CGs around FSI anyway. It brought back memories of our many chases from the late 1980s down to NW TX, then back on I-44 through rain and lightning bombs. The crawler show on the N side was fantastic when they did erupt, but very sporadic and intermittent. I stopped just W of CHK for lightning photography, trying the 17 mm wide angle at slightly higher than usual F-stop. This was in effort to catch some of the insanely bright crawlers that would sparkle nearly overhead from the MCS to our SSE, then slam a CG miles behind us with a deep, long, window-rattling report of thunder. I missed the best crawlers between shots and while setting up, but did get a few more distant crawler+CG combos.
If we had left earlier, if we hadn’t gotten sidetracked with the “Dunlap” storm…well, we might have seen the tornado from closer with much more confidence and certainty…or hit some fat, stupid cow and ended the day upside down in a flooded ditch, slurping mud and crying for mommy. Who knows? As we’ve said before: “If ifs and buts were candy and nuts, it would be Christmas every day.”
We got back to Norman fairly satisfied with the chase, tornado or not, having seen a sculpted storm and a fascinating morphology and interaction process. All in all, it was a worthwhile trip for such a distance, considering the constraints imposed by sleep rotation from evening shifts to overnights.
Three remarkable non-events happened on this chase that are absolutely amazing, if you know either of us:
1. Rich didn’t blow a head gasket and launch into a tirade the whole day!
2. I didn’t fill the car interior with buttgas even once, despite consuming two Allsups burritos!
3. We didn’t hit a single red light from Matador to my house in east Norman, including all the usual unsynchronized flytraps along Highway-9 around south Norman!
The odds of all three of those must be as low as the odds of seeing a fat tornado in a different county from NNE of Matador, and not believing it at the time.
(reposted from Weather or Not [Roger’s weblog])
My target area is where I expect to begin the active intercept, plain and simple.
THE IDEAL: Forecast location of initiation of storms most likely to become photogenic and/or tornadic supercells.
THE REALITY (situationally dependent):
Situation: The above, if I can leave early enough and storms aren’t going to be racing along at Warp Six.
* Example: This strategy worked absolutely perfectly for Rich and me on the Stockton KS day (15 May 99). We made a fantastic storm initiation forecast that morning in GLD, saw no more data the rest of the day, ate a leisurely late (all you can eat!) lunch in Colby, then sat on a hilltop NW of Hays for an hour or so watching Tcu in the narrow corridor between advancing dryline and retreating outflow boundary. The eventual Stockton supercell went up just to our NW, with roads favorably aligned/positioned for observing, and intercept and viewing of the tornadic phase was ridiculously simple. This is extraordinarily rare, the ultimate dream of every chaser, and for that, the #1 ranked chase day of my ~20 years doing it.
* Situation: If storms will be fast moving and/or there are unfavorable geographic barriers like a river valley or lack of roads, the target is about an hour downshear from where we expect CI, based on forecast storm speed and direction.
Example: This strategy worked reasonably well for us 19 Apr 96 in IL. No data seen after initial forecast that morning in KC. We targeted the area E of the dryline bulge in west-central IL. Initiation was expected in MO, but we wanted to be E of the MS River in order that our options would not be limited by the river itself, and that a fast moving storm would have room to mature into early tornadic potential before it got to us and active intercept would begin. We were within about 400 yards of the start of the first tornado near Winchester IL. Only unfavorable roads, and a long train of cars behind a puttering yokel who drove 25 mph in a 55 mph zone for 12 miles, kept us from being in optimal position for the next couple of tornadoes we saw.
* Situation: If initiation will occur before we can get there, or has already happened, the target is just downshear and slightly to the right (usually E) of where I expect a photogenic and/or tornadic supercell to be by the time we can reach the area of interest.
Example: This strategy worked fairly well on 10 Jun 4, where Elke and I headed W from LBF immediately upon noting initiation in VIS imagery near Julesburg, with the storm headed toward a narrow but intensely favorable area of combined buoyancy and shear. Secondary target was easily attainable farther SE once we would be done with this area. We knew the storm would head into the Sandhills, and that we had to zip there fast on favorably positioned I-80. The result: 38 minute tornado observed. Then we let the storm go off into the almost roadless Sandhills, still marginally tornadic but a messy HP that we didn’t mind leaving at that point. The secondary target (dryline bulge into SW Nebraska and NW Kansas) gave us two more supercells but nothing tornadic.
* Situation: First storm craps out, doesn’t develop, or becomes very difficult to intercept because of roads and terrain. Reposition to a preconceived secondary target.
Example: 10 Jun 4, as above. Also was 25 May 97, when Steve Corfidi and I were time constrained by being on a day shift at work. No data was seen while in the field on either day. The major area of potential S of ICT was unreachable…too far! Our initial target, therefore, was the supercell SW of Norman near Middleburg, which was ongoing by the time we could leave. Secondary target was the “tail end” area farther SW around Duncan or Elmore City, in case our storm went bad. We simply could not get there in time for the tornado on old Highway 9, and instead saw the storm wrap up into a horrendous HP bears cage — tornadic but terrible for observing. We briefly watched two more rotating storms in close proximity to the SW — one near Lindsay that was scrawny and didn’t look to have much future, the other near Purdy that had a rotating wall cloud and brief stubby funnels but was headed into unfavorable road network. On supercell number four, we found the treasure — friendly Okie farmers who gave us cold Pepsis in their west-facing garage as we casually chatted and watched the Duncan tornado in the distant WSW. It was an ad-hoc, rural Oklahoma, tornado-watching party. Quote of the day: “Yeah, we see them twisters all the time. There was one a few years ago over yonder across them fields, tore them fences all to hell.” We later observed the infamous “UFO funnel” near Loco. Photos and summary here.
* Situation: Multiple potential targets, pick the best for viewing based on meteorology, roads and terrain.
Example: 16 May 91, Haysville/Andover II storm. Another day with no data seen after making the forecast. I analyzed maps at DDC and picked a target area along the KS border N of END, near the forecast location of the dryline/outflow triple point. [Rich, who wasn’t with me that day, was even more precise on the phone: Anthony KS, earning him the temporary title of “Supercell Prophet.”] After a brief survey of damage in Laverne from the previous day’s event (which I missed!), headed E to END. All along the way I could scan for robust CI from within the crystal clear dry slot, while watching a magnificent arc of Cu and Tcu located W-N-SE. Saw the well positioned storm go up to our NNW while near Medford, intercepted it near Conway Springs, and observed five tornadoes along with 5 inch diameter hail. Other possibilities were farther E along the outflow boundary near TUL (distance, trees) and along the bent back occluded front ENE of DDC (closest target but concerns about both weak instability and too many storms). Tornadic storms did fire in both alternate areas, but we hit the jackpot that day.
Those are examples of how it can and should work. Other situations dictate different target determinations; but for me those have been the most common modes of targeting. Naturally, there have been many, many more days where it didn’t work out as well as hoped, including most chase days last year. The days I didn’t get on the “best” storm were those where the ideal target was too far away given personal circumstances, or where I didn’t make the best target choice (i.e., 11 Jun 4 in IA, too far E along the warm front). Such is life. Live and learn!
Thanks to Bob Henson for generating discussion offline about this topic.
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