Southwest Oklahoma Classic-HP Supercell
Hollis to Apache, OK
13 Apr 12
SHORT: Chase route GCK-LBL-HHF-LTS-OUN. Intercepted occasionally photogenic supercell from inception near Hollis to N of Duke, then as it got absorbed into what became an HP “Stormzilla” NE of LTS that crossed Wichita Mountains. Activity forming SW of that merged/absorbed it after dark N of Apache.
LONG:
The day before turned into a storm-free “bustola” on the western Kansas dryline, with only distant convection to the north near sunset. Elke and I salvaged something from the 12th by heading to Monument Rocks for the late-afternoon light, then bunked down in GCK.
Today’s most straightforward storm intercept target was over the NW TX, SW OK and SE Panhandle region near CDS. We left GCK for a long but simple jaunt SSE down US-81, with lunch in Perryton. While there, storms already started firing over central and SW OK. Early initiation stinks, especially when the observer still is over 150 miles away!
A distant line of building convection hovered just above the SE horizon as we headed out of Perryton. Now we targeted the area of its prospective backbuilding into the slowly retreating late-afternoon dryline. The pre-dryline baroclinic zone upon which the storms were forming was supposed to retreat N also, after 21Z. My thinking was that the future western storms would represent the latest, highest-CAPE development, farthest removed from the threat of interference by upshear convection.
Given our distance and target area, we obviously missed the Norman tornado, not that we would have targeted specifically that needle-in-haystack HP supercell event anyway. As we reached Wellington, big towers began to backbuild on the pre-dryline boundary toward the Hollis-CDS area; so we turned E on US-63 into SW OK to get into position. We fueled up at Hollis as a young storm began rotating ESE of town, and newer convection with cores formed to our S-SW near Vernon and CDS.
Using phone radar, I noticed a nasty-looking hook had developed on the W side of Norman, with an HP supercell attached to a larger cluster of storms extending westward. It was a mess, but a mess with a meso. I called my daughter, who told me she just had experienced a tornado at the high school and had been safe in a windowless room, under a desk. The first concern, and relief, was that she was fine. My son was elsewhere, well SE of the path. Both were OK, so I could shake my head and marvel at the truth that, once again, a tornado had occurred in Norman with me observing other storms far away.
We cruised E out of Hollis, preliminarily targeting the storm to our ESE, but with a contingency to stop and let the newer development to our SW (then the tail-end conceptual target) come toward us if it started looking good. That’s exactly what happened. CGs from the newly organizing, tail-end convection slammed all around us between Hollis and Duke. We turned N out of Duke, found a good vantage 3 N of Duke, let the disorganizing eastern storm move away to our NE, and watched the newer storm approach and strengthen.
Alas, still more convection formed upshear, but the storm began looking distinctively supercellular as it crossed the section road to our W. This would become the Altus-Apache supercell, but not before producing a nice wall cloud, one with strong rising motion but only modest cyclonic turning. Another lowered area, likely from an older occlusion visible in the last windmill shot, loomed in the background.
Neither got any better organized; indeed, the entire storm started looking somewhat strung-out. We considered breaking off and heading toward the newer activity W of Hollis and W of CDS, as some others already were. However, we needed a pit stop in nearby LTS, while the supercell began turning into a dark, menacing, precip-filled mass to our N. We decided to stay with it for awhile, watching what by now was an HP “Stormzilla” over the western nubs of the Wichita Mountains.
Our supercell developed a nasty-looking HP hook on radar with a deep, intense mesocyclone; but we couldn’t see anything in the dark murk from LTS regarding the tornado report near Blair. Even without the bathroom break, I’m not sure we would have been able to get in position to see much.
By the time we reached Snyder, it was to late to do much with the western convection before dark. We also knew that the storm would head into an awkwardly configured road void in the Wichitas, cutting us off. [I had circumnavigated the void successfully last November 7, but from a different angle. That day, I beat the storm. This day, the storm would beat me.]
Driving several miles N out of Snyder, we hoped to see whatever the storm had to offer before it got into that road void. Here was its S side, along the rear-flank gust front looking W. Here was the E side, looking NNW toward a small but slowly rotating cloud protrusion with a clear slot. That looked interesting for a few minutes, until being undercut by a massive surge of the heavy precip-loaded RFD.
The photogenic HP storm moved off into the road void to our NE, and we knew it would be dark by the time we could get through Lawton and go N toward Apache to see the storm again. The storm produced a rainy twilight tornado during that interval when we were repositioning, fittingly enough.
By the time we reached Apache to see what was left, we found a storm still supercellular but again messy. Our viewing timing with respect to the best-organized stages simply wasn’t working out. At least, for a short time, the downshear anvil region sparked mightily and beautifully overhead. Our last decent wide-angle view of the storm, from a hill just E of town, featured the lights of the wind farm and Apache to our W, what was left of the wall cloud and main updraft region near center (NW), the vault area to the right (NNW), and of course, cows.
Before the storm could cut off itinerary options again, we headed NE toward Chickasha and home. The storm merged with convection to its W, evolving into a small bow, then moving over Chickasha and toward the Purcell/Pauls Valley area a weakening blob of rain and occasional hail. By then, we were home, tired from the two-day, thousand-mile trek, but eagerly anticipating the big severe-weather day of the 14th.
November to Remember
Tornadic Supercell in Southwest Oklahoma
7 November 11
SHORT: Intercepted two nontornadic supercells and one tornadic in SW OK. Witnessed multivortex tornado move through wind farm, among others.
LONG: This has been a very fortunate year for me for storm observing, and a rare juxtaposition of a day off with a November chase day offered the promise of icing on the fine tornadic cake that has been 2011.
Pre-storm
For several days, a classical, spring-like, near-dryline supercell setup appeared to be looming…in autumn. Looking at the morning charts and RAOBs, the presence of very nearly surface-based effective inflow parcels even during early-mid morning (using FWD and OUN soundings) reinforced my main concern–the potential for early initiation, maybe too many storms too soon. Otherwise the foci for supercell and tornado potential looked fairly well-defined, the target area compact: approaching, progressive shortwave trough aloft with deep-layer shear strengthening throughout the day, adequate moisture return, backed winds, and enhanced low-level vorticity along an outflow boundary E of a dryline and cold front…all in the southwest OK/NW TX area.
After morning appointments (I try to avoid scheduling any immovable commitments for afternoons even in the “off-season”), visible imagery showed good clearing from the southern tier of OK counties (LTS-FSI) southward, and towers already starting to deepen in the weak CINH even before noon. The deepest warm-sector convection already was forming near 100W (TX/OK border longitude), with other clumps of shallower convection farther ESE over NW TX. Time to head out the door!
Early, non-tornadic supercells
Perhaps I left a little too soon; this is a longstanding bias of mine. Still, I targeted the LTS area via the NE (HBR) instead of E (FSI), in case any decent storm rode up the western fringe of OK and into the baroclinic zone. I’ve had a few successes with early-event tornadic storms tucked in the NW side of a SE-expanding storm regime, and a supercell SW of Mangum was getting larger.
By the time I reached Lone Wolf, on the way toward Mangum, a messy cluster of storms with some banding and supercellular tendencies had formed to the SW (wide-angle). I considered staying near there, and perhaps should have in hindsight, given a few observers’ later reports of a short-lived multivortex tornado with an eventual supercell SW of HBR. Instead, I headed to the western storm, somewhat concerned that my onboard thermometer indicated only the narrowest of slivers of diabatic warming between the HBR cluster and the now tornado-warned Mangum storm.
The western storm came into view NW of Mangum; I parked 2 WSW Brinkman to let the storm move just to my W and N. It was somewhat pretty, but not too promising. An earlier, distant wall cloud had vanished, and the storm looked rather strung-out. A new mesocyclonic cycle yielded a weakly rotating, nice-looking little wall cloud, but it couldn’t tighten up and produce. Moreover, the probability it would was dropping by the minute; inflow air was getting cooler! Naturally, the storm started to weaken.
By this time, a small cell I earlier had noted on radar, S of the Red River and S of FDR, had exploded and was taking on obvious supercellular signatures. I was out of position for anything it would do in the next 1-1.5 hours, and knew it. But I also knew it would have a long potential trek through vorticity-rich air of at least marginal buoyancy, all the way N of the Wichita Mountains, if no other storms erupted to its S or SE. For now and for hours, that southeastern storm would remain unimpeded that way.
I wasted no time in deciding to go toward the FDR storm, but two other supercells were in the way: one just SW of HBR (the early multivortex producer I missed) and the other slightly farther SW, also approaching HBR. My best chance at shooting the gap between these two supercellular obstacles and stay on course for the southeastern storm was to head back through Lone Wolf to HBR, around the northern flank of the southern-middle storm and S of the hook of the northern one (beautiful rainbow scene on their collective W side). I threaded between the two most dense core regions; but the gap was small and I did encounter some small to marginal-severe hail in the southern (nontornadic) HBR storm’s forward flank. Here’s a wide-angle look at the southern-middle storm between HBR and Roosevelt, looking WSW.
Turning S out of HBR, my timing looked barely adequate, and more likely too slow, to reach the FDR storm S of the Wichitas. By now, I already had heard of a couple of tornadoes it had produced; and the storm appeared to be trucking along nicely with a powerful low-tilt velocity signature. Instead of trying to stern-chase it on US-62, only to encounter a road void in the Wichitas, I chose to head E out of Roosevelt, skirt the storm’s northern flank, and wait N of the Slick Hills for the supercell’s business end to come toward me. I knew the massive, E-W oriented Blue Canyon Wind Farm was a couple miles S of OK-19 too, right in the meso’s path, and might provide an interesting foreground for whatever emerged from the rough terrain. It would be my first correct strategic decision all day.
Post-Wichitas phase of tornadic supercell
Heading E from Roosevelt, I could see some of the rear-flank convective wall of the FDR supercell to my S; while a very bright rainbow with secondary accompaniment festooned the fringes of its left-flank precip core. I zigzagged the necessary roads toward the area NE of Saddle Mountain, encountering more mainly sub-severe hail in the tornadic storm’s northern rim. The hook echo was very impressive on radar, when I had any phone data in this reception-deprived area, with one scan of ~100-kt gate-to-gate shear. By now, I was preparing for the possibility of a big tornado coming out of the mountains and through that wind farm.
A fine viewpoint appeared ~5 SW Alden on OK19, with a surprisingly green field of winter wheat leading SW toward the ridge-top wind farm. The mesocyclone’s orbiting rim of cloud-base scud came into view to the SW, circulating at impressive peripheral speeds that I’ve seen only with tornadic settings. The meso was translating directly toward me, but still with plenty of time to spare and a good escape route eastward. Time to rock and roll. Alas, a furious bombardment of close CGs kept me under within the vehicle for several more minutes. A group of unrecognized chasers showed up at the same vantage, standing outside rather unwisely despite the occasional CGs still hitting within hundreds of yards.
Fortunately the electrical attack from above abated fairly quickly, and we all could concentrate again on the approaching mesocyclonic menace. I was very confident a tornado still was lurking beyond the ridge line near Saddle Mountain; and within minutes, that suspicion was confirmed! The visible condensation funnel of the tornado, still beyond the ridge, vanished from obvious view for a minute or two, the visible parts of the cloud base seemingly boiling with furious movements. The tornado reappeared even better. I strongly suspect this was the same tornado as before, given
1. Its temporal and spatial continuity relative to the ambient mesocyclone circulation, and
2. Later TV-chopper videos I’ve seen of the Saddle Mountain tornado, which dissipated right before reaching the wind farm.
A new, strongly rotating wall cloud formed N of the dissipated tornado and over the western part of the wind farm. In fact, its base was so low that the turbine blades extended into the cloud! The new circulation also extended E of the visible wall cloud, which seemed to subsist on recycling of rain-cooled air from the precip wrapping around the N and NW sides of the hook. This fascinating process was about to get more so, and fast.
On the E (left) side of the mesocyclone, slightly displaced from the lowest part of the wall cloud, a multiple-vortex tornado, containing a dominant central condensation tube, developed over the wind farm. This was obviously separate from the earlier tornado. Since some of my home’s power comes from this wind farm, I was hoping against its destruction; in fact, as the tornadic circulation continued to swirl through and around the turbines (wide view and cropped), I saw no clear evidence of damage.
Small suction vortices occasionally formed and pirouetted gracefully among the turbines (wide view and cropped), as the main cone became more sharply defined (wide view and cropped). The entire scene was strange and ironic — a wind farm under siege from the ultimate in “wind power” (wide view and cropped).
Through the whole ordeal, the disabled blades held firm, not budging nor popping loose, despite the undoubtedly intense mechanical stresses. The functional turbines seemed to adjust their alignment (with some lag) to the mesocyclonic wind shift, but of course, couldn’t do so fast enough at tornado-vortex scale. The blades’ rotation speed seemed to remain fairly steady, which fits the purposeful design of such machines to brake the spin rates in order to minimize damage in extreme wind. This certainly qualifies as extreme wind!
A powerful, precip-laden RFD surge hit the tornado, weakening it while sending the remains of the circulation careening ENE through the N side of the wind farm, at an oblique angle. A newer mesocyclone was tightening up rapidly, immediately (just over a mile ) to my SW, so it was time to reposition a tad east. While driving, a glance in the right-side rear-view mirror revealed a new, entirely separate tornado developing as a tall, slender tube. This pretty, partially rain-wrapped tornado (the third for me so far) only lasted a couple of minutes, dissipating as it reached OK-19 near where I had parked before.
This newest mesocirculation, with wrapping rain curtains, shot toward the NNE beyond OK-19. I headed E a little over a mile to OK-58 then N, watching it weaken as it obliquely approached the road to my immediate WNW. The mesocyclone dissipated fast. Still, rain curtains seemed to be moving fairly quickly in assorted directions around me. Frequent glances at the cloud base above revealed strengthening, convergent westerly flow. I soon saw why.
Yet another quick occlusion was about to occur, as another mesocyclone developed a short distance to the E. This was not the optimal position for any storm observer to occupy, so I searched for a good E option that would take me out of the backside of the hook. [Fortunately, the storm continued its trend of producing non-damaging hail with respect to my vehicle.] Now WNW of the new circulation, I turned E on E1380 Road toward “Pine Ridge”, a crossroads with neither a ridge nor pines. The road was reasonably well-drained, alternating between paved and hard-packed gravel with occasional shallow puddles, and was good to go at 50-55 mph in high 4WD.
Right after my turn, a fuzzy cone tornado materialized to the ESE, allowing a brief stop to photograph it before the rear-hook firehose started dousing me. The white smudge in the last shot, below and to the left of the tornado bottom, was a hail splash.
Back on the road again, I carefully approached the mesocyclone and tornado from the W, watching the latter dissipate and the former rotate intensely as it crossed E1390 about a mile away. This circulation moved N, and yet another one (the eventual Ft. Cobb tornado producer) developed just to its E. By now, the storm definitely was translating poleward and speeding up, getting away from me even as I drove the short few miles to my N turn on N2550 at “Pine Ridge”.
Seeing occasional multivortex filaments form under the new circulation (the Ft. Cobb tornado), I stopped briefly to photograph the storm structure with the mesocyclonic cloud base below (deeply enhanced crop-n-zoom). Heading N toward Ft. Cobb, I could see occasional plantings of full ground-cloud condensation; but every one of the 4-5 times I tried to pull over and photograph them, the condensation would go away. Daylight and contrast each grew dimmer also.
After escaping Ft. Cobb, I drew closer to what was left of the circulation near Albert, its cloud base still rotating and low-hanging in the twilight, but obviously weakening. I couldn’t complain much, though, I had found my fifth tornado of the day, a pretty remarkable feat considering some poor tactical decisions early in the afternoon that caused me to miss a fantastic tornado show SW of the Wichita Mountains.
Epilogue
The trip back was mercifully short, as the former FDR-Ft. Cobb supercell got absorbed ingloriously into a building band of storms near Okarche. How often does one arrive home by 7 p.m. after a multi-tornado intercept? Despite what I had missed, these were my latest tornadoes seen in a calendar year, and multiplied by six the sum total of lifetime November tornadoes.
To make the day truly unique, I got to experience an earthquake too. Not long after settling in at the house, a low, thunderous rumble and weak vibrating of the house signaled the magnitude 4.7 aftershock from the Sparks earthquake swarm that had been rattling off and on for several days. I had felt the Oklahoma-record magnitude 5.6 shaker a couple of nights earlier while in a cabin at Greenleaf State Park (my first ever). With multiple earthquakes and tornadoes witnessed in a 3-day span, it was a marvelous time for an earth scientist in Oklahoma. 2011 also has been, by far, my most prolific tornado year.
As with the 20 June tornado-fest in Kansas and Nebraska, I sent an itemized table of tornado times and estimated locations to the WFO, with embedded links to many of the same photos as above. That table includes times, locations and links to the photos. What had been listed as one tornado on coarse-resolution maps, from S of the Wichitas to OK-19, should become three in the final record. The tornado log file is in the public domain, and linked here in MS Excel format, freely accessible for anyone interested.
Mesmerizing Mammatus Moments
Pritchett CO Supercell
Assorted Storms and Sunset from Boise City OK to Liberal KS
11 June 11
SHORT: From McPherson KS, drove almost directly to Pritchett Co, saw brief tornado with supercell due W but no photos due to untimely town transect. Supercell died, as did another SW of Boise City. Intercepted back side of Turpin storm, photogenic outflows from trailing squall line. Amazing mammatus sunset followed by fun dinner with CoD crews in LBL.
LONG:
This was a splendid first day on the High Plains for us in 2011! The day after hanging out in the beautiful Flint Hills, Elke and I headed W out of McPherson KS on the most direct route bypassing DDC to our target area of SE CO. We stopped along the way just briefly for fuel and to photograph an abandoned shed.
As we got to Syracuse KS, storms already had formed N of the RTN Mesa and W of US-287 in CO, our decision being to intercept the northern storms in a better road network, or the southern, newer storms that promised more unimpeded inflow for longer. We quickly decided on the latter and went S and W through Springfield to Pritchett.
Despite the densely wrapping hook echo on reflectivity displays, we didn’t expect anything substantially tornadic from the southern storm W of Pritchett, which by now had evolved into a mature, intense but high-based supercell. Alas, right as we started to enter town from the N, Elke noticed a conical funnel under the base to our distant W, protruding about 1/3 groundward, with a dust whirl beneath and thin, translucent debris sheath extending between dust whirl and condensation funnel. Of course, it had to be while we were trying to get through the only town within many miles; and I only caught a couple of brief but unmistakable glimpses between buildings. So did a cop; for staring that direction, he tore out of a nearby alley, sirens and lights blaring, briefly blocking the road before drag-racing Duke Boys style around a gas station and vanishing in a dust plume of his own making.
By the time we exited the S side of town, the tornado was gone–no photos, only memories. All visible vortex traces vanished into Colorado-thin air before I could call it in; but I did so anyway. The PUB forecaster seemed relieved that the warning verified, even if by a brief cheezenado.
We cruised W to an observing spot E of Kim, admiring mammatus to our N more than the increasingly featureless and drab storm now devolving to our W. A broad mass of showers and thunderstorms was growing to the older storm’s SE and dumping cold outflow into its inflow–certain doom for a once-powerful and briefly tornadic storm. Where next? Plenty of daylight, and we were storm-orphans. Cells were firing in the north-central Panhandle of OK, far away but reachable; and we could see the anvil of a persistent, solitary but undoubtedly very high-based cell to our S in NM. We had to go to Boise City for a chance to peek at either; so back we headed to the far fringes of our current home state.
Fifteen to twenty minutes spent at the front of a stopped line of vehicles, waiting for a flagman and pilot car on US-287, either cost us an inflow view of an intense supercell later or saved our necks; I’m still not sure which! By the time we got out of that, the remnants of the NM storm passed by CAO and came into view–not surprisingly, a widespread virga bomb dumping downbursts…albeit a wonderfully textured and photogenic virga bomb.
After fueling in Boise City, we targeted the supercell approaching LBL along the KS/OK border, glimpses of which we could see to our distant E and ENE ever since being stuck in the conga line on 287. Along the way to GUY, I couldn’t resist quick stops for two Great Plains specials: a striking scene of an abandoned barn high in late-day sunlight, as if sailing through an ocean of golden wheat, and from N of GUY, a high-based but beautiful Cb to our distant SE near Booker (the next storm W of what became the Follett supercell).
We headed NE from the GUY bypass toward Optima, greeted by the development and maturation of a pretty front-lit and under-lit arcus from the tail end of a short squall line to our W, NW and N. The earth, desperately dessicated and thirsty as you see, was about to get a much-needed drenching and quenching.
That’s what was happening behind the “Liberal-Turpin” supercell that, once we got to Hooker, was E of the road, sitting directly astride US-64 between Hooker and Turpin. Its meso wrapped across the highway to our E, blocking ready access. Police had US-54 blocked heading NE toward LBL, probably because of (by now) very old information about the supercell; so we turned E toward Turpin, creeping up to the back side of the raging HP monstrosity, able to see only scud and wrapping precip rolling southward in surges around the otherwise unseen mesocyclone. I knew what that meant, and considering past lessons, we weren’t about to core-punch it for any price or dare.
If we had arrived 15-20 minutes sooner, without the earlier traffic blockage N of Boise City, we might have made it; but then again, we also might have missed the amazing sunset show that followed. And that would have been a damn crying shame!
Instead of pondering could-have-beens, we admired still more outflow, this being the curiously lit E side of the arcus from the squall line to our N, looking past Hooker. We let that shelf roll over us for some eerie illumination, then plunged through the wet but harmless band of precip to get to our lodging in LBL.
As we entered LBL, it became glaringly obvious that a spectacular sunset show soon would ensue on the back side of the storm complex. The low, golden sun shone through the last curtains of trailing precip, and also through those, we already could see a field of mammatus aloft through chunks of ragged scud clouds evacuating eastward.
We secured our room keys from our favorite little motel there, then headed N of town for a gorgeous Great Plains sky of sunset mammatus that made the entire convoluted trip, every minute of it, worth its unforeseen destination in images such as this. Yet photos, beautiful as they may be, only can convey two dimensions of one sense: vision. This was not just a scene, it was an experience.
Land parched by drought sprang to life in a soothing blend of sound and aroma, cool and moist, as thoroughly refreshing to me as to the dozens of western meadowlarks celebrating in song across every compass point. I longed for the physical capacity to inhale ceaselessly, so as to miss not a millisecond of moist, earthen scent flowing across cool breezes, while sunset’s golden and reddening glow reflected first off the moving tapestry of mammatus clouds above, then off the land below and all around. For a fleeting few minutes, arms spread wide into the breeze, eyes gazing aloft, ears in stereophonic reception of the avian chorale’s cheerful spontaneity, smells of freshness and cleanliness and life, I ventured into a timeless place far outside the confines of self. It wasn’t the first time under such circumstances, either.
Let me assure you, when you are open to releasing your shackles of distraction and worry, and diving headlong into an experience of this nature, every sight, sound and breath swirls together as one multidimensional immersion in full appreciation reaching far beyond words and images. It’s a conscious decision, a gift to accept, an act of release and absorption, letting go and drawing in. These are the occasions when we let go unconditionally, in spiritual as well as sensory ways, bathing in a rejuvenation of sorts that cleanses all accumulated grime from even the farthest crevices of our being. If this is but an ephemeral and incomplete preview of heaven, count me in when the time comes.
Then came the slow descent back into reality, as the colors faded and a growling stomach begged for tangible nutritive sustenance. I noticed, via SpotterNetwork, that Paul Sirvatka and the CoD crew were headed into LBL from the S, so I called and invited them to join us for what turned out to be a fine dinner with enjoyable company.