Inadvertent Tornado Avoidance

May 28, 2012 by · Comments Off on Inadvertent Tornado Avoidance
Filed under: Summary 

Central and Southern KS
14 Apr 12

[EDIT] The photo links work now! Thanks to Jim Caruso for noticing that.

SHORT: On a “HIGH RISK” outbreak day, intercepted 4 daytime supercells, somehow during mostly non-tornadic stages. Two brief spinups seen, lasting less than 20 seconds total. Great anvil-lightning show with Wichita supercell after dark.

LONG: On this day of a well-forecast “High Risk” tornado event, Elke and I headed N out of Norman in plenty of time to osition ourselves ahead of the dryline bulge in central Kansas — smack in the middle of the most probable track zone for one or more future supercells. Storms would be rather fast-moving, with limited time to view any single storm without driving at unsafe speeds on the township-range zigzags to keep up. Cells also were likely to develop later with southward extent. Given these conditions, therefore, our plan was to start somewhat north, tview a storm for awhile, then hopscotch down to the next one.

That normally well-reasoned idea somehow didn’t optimize our success. We would intercept five supercells in the High Risk area, but somehow only see several seconds worth of marginal tornado action the whole day.

Supercells One and Two

We arrived at HUT to refuel, heading W to get ahead of new but already supercellular convection just SE of DDC. As we approached St. John,. two originally discrete supercells to our WSW began to merge. The northern storm was more intense, and getting a strong velocity couplet on radar. The problem, at that point, was a classic case of mutual storm-scale interference: the southern storm was dumping big loads of precip into both the flanking area and part of the inflwo of the northern one, and the northern storm’s outflow was rendering the southern storm somewhat elevated. This unfortunate situation would persist for the entire time we observed the two slowly combining supercells.

West of St. John, and just two counties to the SW of its eventual violent-tornado exhibition near Kanopolis Lake, what would become the Langley-Salina supercell was a merged complex of two storms–a fuzzy, rain-wrapped HP mess. See for yourself (looking WSW at wide angle).

Storm-scale problems plagued our stage of this convection. During the 30-45 minutes we actively intercepted it (this was, as expected, a fast-moving storm!), the classical cell-merger conundrum was sickening the storm(s) like a wretched jungle disease, yielding a big pseudo-supercellular mess. The northern merger member (dead ahead to the W in the last shot) was getting rained on from the southern one’s ramming into its SW side; and the southern one’s updraft base (distant left rear) was non-rotating, scuddy, and apparently elevated above the outflow from the northern one. The main meso (left of grain elevator) was on the NE side of the whole mess, and rain-wrapped with a giant gob of precip to its S.

Until this day, I’ve never known an HP in that sorry condition to recover to the level it eventually did. Away from the heavy rain, there was just light anvil precip in its meso-gamma scale inflow; but it did feel cold; temps were in the 70-72 F range at my location the entire time. This was our last decent view of the storm as we headed E and it got further N. As we proceeded E and started targeting the next storm, its convective turret even looked rather mushy and sharply tilted, as if the storm was CAPE-starved.

Even after numerous scientific papers written, over a quarter-century of storm intercepts, and hundreds of supercells observed, events happen afield that both fascinate and befuddle me. I’m still flabbergasted at the spectacular and complete reorganization the St. John supercell underwent, after it parted with us. Some combination of storm-scale shedding of precip and entry into a ribbon of subtly higher theta-e air advecting from the ICT area may have done amazing things to what had been a moribund and junky-looking HP, and turned it into a photogenic and violent tornado machine farther NE. Could we have caught back up for at least a short reunion somewhere near Lyons, while driving safely? Probably–however, the eyewitness evidence we had seen was underwhelming. Now that you’ve viewed what it looked like back around St. John, I trust you understand.

Supercell Three
Another storm had moved across the KS/OK border and developed a nice-looking reflectivity hook near US-54, in the vicinity of Cunningham, to our SSE. This proved to be a fairly easy target near Arlington, with some storm-scale supercell structure but a rather elongated, unimposing base and a ragged overall appearance. The former hook had gone away by the time we got to the storm. By now, we were starting to wonder, “What’s the deal with this day? We’re already ruining storms.”

Under the north portion of that base, two conical scud filaments formed and began slowly rotating around each other, then aggregated into a scuddy lowering (probable funnel) that was rotating slowly. That was the best the storm could do. It turned more leftward and mysteriously perished with great haste W of HUT. Time to scoot SE and S out of the HUT area toward the next hook-bearing supercell, also crossign the KS/OK line.

Supercell Four

Finally, we got on a storm that acted like a tornadic supercell for at least a short while. We headed S out of Haven toward the E side of Cheney Lake, where the valley containing the reservoir conceptually would act as a good terrain chasm across which to view the next storm. As it turns out, we stopped short of there due to trees, from a point located 8 SSW Haven and about 2 miles E of the lake.

Allowing the storm to move toward the NE took it due W of us, whereupon we began seeing a broad, somewhat fuzzy base with a core and rain-wrapped wall cloud. The system moved to our NW, as I shot vertical wide-angle imagery of the storm and intervening cloud cover. As I was removing the lens for a swap, Elke saw briefly tornadic condensation to the ground, looking WNW into the more distant, older cloud base and occlusion (which was associated with the rain-wrapped wall cloud before). I saw a couple of seconds of it while fumbling around to get the other lens back on, and of course, it went away just in time for me to shoot. It turns out that a deeply contrast-enhanced crop of the last wide-angle shot shows the start of that condensation (which was a full tapered-cone during my lens-exchanging exercise). Time was 1907 CDT (0007Z).

Of course…that’s how this day was going to be! As I was looking at the area (but not shooting), a funnel appeared on the nearer cloud base, and a fast, quick little spinneret of condensation swirled just above ground level and leftward of an intervening tree. By the time I raised the camera to shoot, the funnel tip had gained height, and the spinning condensation near ground was gone. The circulation of the old occlusion continued too, in the background, but was not obviously tornadic anymore (contrast-enhanced version). Then the closer funnel vanished, and a brief one appeared in the old occlusion again (enhanced). This storm was playing cruel teasing games with us, it seemed.

After seeing no more definite funnel action, we zigzagged NE with the storm for the longest distance of any yet this day — all the way to W of Newton, before storm motion, imminent darkness, and a growing concetnration of chase vehicles made continued intercept unfavorable. It was nontornadic for that stretch, with a ragged to fuzzy and disorganized cyclonic shear zone passing for a “mesocyclonic” area the whole time. Nonetheless, it apparently produced a tornado or two after it got away from us (NE of I-135). Spot a trend here?

We grabbed a fast-food dinner in Newton, making haste in order to be assured of beating the former Cherokee/Manchester OK supercell across that stretch of the Kansas Turnpike just S of ICT. As we ate, phone radar showed a velocity couplet crossing the OK-KS border that I’ve seen only with violent tornadoes. That duly motivated us not to tarry!

Supercell Five–Nocturnal

Skirting the downshear fringes of the forward-flank core just S of ICT, we beat the storm to I-35 with ease. I remember remarking to Elke, somewhere not far S of the I-135 toll booth, “If we break down in this very spot, we would be in deep, deep trouble.” On a different night, I might have tried exit around Mulvane and maneuver closer in toward the meso area for a look. Elke has a manifest dread of night-chasing tornadic storms, however; and we both were getting very weary. We instead zipped down the turnpike to the next (Wellington) exit, safely south of the storm’s projected track, and “settled” for lightning from a distance. Though we were too far away to make out the tornado(es) SW of ICT, this still was a treat, the best visual show of the day, by far.

Filamentous lightning zapped across the upper reaches of the storm almost continually. These types of discharges are some of my favorite observational aspects of nocturnal supercells. I shot dozens of photos like this, this, this, this, this, and this and could have shot hundreds. By a small measure, we salvaged the storm day with this grand electrical spectacle.

After low clouds got in the way, we got fuel in Wellington. It was a treat to speak with Terra Thompson there, from whom I learned more abut the amazing Cherokee storm, and to whom I extended congratulations for her successful intercept thereof. Rich Thompson (unrelated) resoundingly demolished his tornado drought with a bountiful harvest of vortices from the same storm, waking up after a mid shift and leaving “late” from Norman.

Epilogue
Lest you interpret that I document these events from some simmering dungeon of resentment and woe, that is false. I compete with nobody in the field. Instead, I just want to do the best I can, see amazing processes, experience beauty and majesty in the sky, capture some of that in photographic form, and learn something. I accomplished quite little of each. Admittedly, it stung; I wasn’t giddy to be out there on a big outbreak day and pick only the tiniest possible crumbs off the tornadic smorgasbord. I’m not masochistic. It’s disappointing to discover later what could have been with one turn here or there. But that’s mere hindsight, isn’t it?

The bad-luck part is out of my control, but not the decisions. Part of me really would like to be able to offer you a tale of glaring error I made, in order that you and I can learn from it. I’ve done so before in this forum. But I can’t find any major mistakes or smoking guns that clearly say, “Roger, you dumb-ass ignoramus, you failed right at this particular decision point, you should have known better at the time, and here’s why…” Maybe that’s the hardest part–not knowing.

The irony is that I thought (at the time, without knowing of the northern or southern storms’ amazing production) that we had great strategy–intercepting four supercells on a fast-motion, “high risk” day from good vantages for any tornado that would form. They just wouldn’t produce. Three of them looked surprisingly like fuzzy garbage (including the eventual SLN storm, which looked the worst of the four, on radar and in person, while we were on it).

I’m not sure what I could/should have done much differently, given the information available when I left and while I was traveling. I actually wish I could find something to second-guess about my decisions and strategy that day; it would be easier to learn from true mistakes (as opposed to doing the best with what was known, and just coming up essentially empty). Maybe that’s the best way to describe the impression this day left with me…empty. Not angry, not resentful, not jealous, just…blah. Empty.

Still, after the preceding 10 months of amazing fortune, I am in no position whatsoever to whine or moan. I know that:
1) The tornadic aspect of storm observing is a streaky and fickle thing. Those of us who chased in the late ’80s in Oklahoma understand this truth quite well.
2) There are those who had to work this event or couldn’t chase for other reasons. I’m very familiar with that situation.
3) However beneficial are skill and understanding, both meteorologically and with in-field maneuvering, there still is so much we don’t grasp yet about storm-scale behavior and meso-gamma scale influences. As such, a non-trivial share of both success and failure on any given chase can be assigned to the presence or absence of good fortune.

I had my amazing tornado stretch from 21 May 2012 through 18 March 2011; and that came to a resounding halt over the weekend. The ebb and flow of storm observing works that way. I don’t chase just for tornadoes, or even primarily for them. This was far from my first rodeo. I drew the easiest bronc, rode ’em clean out of the gate, and just slowly slipped off for no apparent reason before the horn sounded. I intend to saddle up again…and again…and again, pardner. I am confident that the tornadic fortunes will return through persistence. Until then, all of these fascinating processes are observed from a framework of appreciation, wonder, and learning. Tornadoes or not, I’ll be out there at every justifiable opportunity.

2012 Season-Opening Success in Southwest Oklahoma

March 21, 2012 by · 1 Comment
Filed under: Summary 

SW OK
18 Mar 12

SHORT: Intercepted merging storms then resulting single supercell over SW OK, with spectacular structure and three short-lived tornadoes.

LONG: A little advanced planning made possible a splendid start to the 2012 storm-intercept season, on the 87th anniversary of the Tri-State Tornado.

Before Tornadoes

My daughter Donna and I headed out from Battlestar Norman at 19 Z, thanks to 1) her outstanding academic performance and judicious spring-break homework planning that freed her this time to chase, 2) her ability to drive to meet me at work, and 3) Greg Dial’s swapping shift hours with me from the previous day. It was a good day for some dad-and-daughter time on the highways and byways of southwest Oklahoma. We targeted the LTS/CDS area, well-advertised for a few days as part of a corridor of dryline supercell potential.
Forecast thinking was that early cloud bases would be somewhat high, but storms likely being discrete given the presence of modest capping and decent component of mean-wind orthogonality relative to the dryline. Low-level and deep-layer shear would be more than sufficient. Boundary-layer moisture would increase as storms moved off the deeper mixed layer air of the dryline environment, deeper into a moist sector.

As we cruised W across the N side of Lawton (S edge of FSI), we started to experience promising breaks in the low clouds, while the first robust reflectivity echoes sprang up SW of CDS and E of Crosbyton. I immediately targeted the northern echo because it would be moving into: 1) the forecast target area, with a somewhat more favorable environment slightly sooner, and 2) a better road network over SW OK than for the storm headed to the Crowell area. Both of these would evolve into supercells eventually, along with a third echo farther S.

As we approached Hollis, the small, young storm came into view, still well to our SW near CDS. Being a softie for abandoned structures of the Great Plains, I couldn’t resist parking at a wondrously decrepit old house, located 3 E of Hollis.

The westward-listing relic of the homesteading era creaked in the wind, as if mournfully moaning some of the last words in its long and mysterious life story. A loose strip of sheet metal on its roof flapped hither and yon in the prairie wind, its clanking noise advertising the structure’s vulnerability for all to hear, but with only us listening. Yes, the old house was well worth shooting, both in its own right and as a foreground for the approaching storm.

Moving generally toward us, the storm became better organized, until distinctively supercellular bands and striations materialized. We repositioned a couple miles east to distance ourselves from the vault’s lightning production, while its base expanded. Another rotating storm formed just SW of the Hollis storm’s flank and moved NE, dumping its own front-flank precip into the back edge of the first storm.

Cloud-base spin began anyway, along with intermittent pockets of faster rotation and rising motion with lowerings (looking W). The first serious occlusion wrapped a good deal of precip around the low-level mesocyclone, with a short-lived, conical, rotating lowering that might be termed a ragged funnel cloud.

Meanwhile, as our gradually merging storm(s) got messier, things got very interesting 60-70 miles to our S. The classical, flying-eagle reflectivity appearance of the middle (Crowell) supercell tempted me enticingly, especially when the red polygon showed up. Despite that storm’s digital allure, we stuck with the northern storm based on visual cues, even through its struggles with mergers and resultant HP-like precip cycles.

Here’s why. The storms’ merger cast a lot of messy precip across the scene, but somehow didn’t kill the initial supercellular rotation area. We would stick to our original target. This was purely an “eyeballs” decision. On reflectivity animations it did look like a disorganized mess. Visually, it still was conducting a series of occlusions. Good thing I trusted my eyes more than radar this time!

While I’ve found wireless radar access generally to be a benefit in the years since its availability, this event was a fine example of how onboard radar access sometimes can be a curse instead of a blessing. When visibility sucks, and all you have to work with is radar, you go for the storm with the best organization, if the environments are somewhat similar. In this case, however, the nowcast environment also was a little better for the northern storm in terms of slightly weaker CINH, and similar to slightly stronger SRH in another 2-3 hours. It was a gamble of patience that paid off.

First, however, the messy, temporarily HP storm character brought down contrast (wide angle view looking NW) as the whole process churned northeastward. A new area of rotation developed ahead of the old, rain-wrapped circulation, as the storm(s) gained distance from us. It was time to reposition N and E through Shrewder. This meant going N six miles on a narrow but hard-packed dirt road if we were not to lose visibility. One stop W of Shrewder afforded us a view of a new and old meso with rainy pseudo-nado (looking NW). Meanwhile, that portion of the second (merging) storm that appended itself to the flank of the first began to exhibit some wild striations nearly overhead to the SW.

Upon seeing that, I knew the combined storm was evolving into a wedding-cake special, and we needed to get many miles farther NE to get enough of the storm in view for decent structure shots. We zigzagged through Russell and Mangum toward Brinkman, watching a couple more occlusions and short bursts of moderate cloud-base rotation. One stop near Russell afforded us this splendid view to the NW. We turned W from US-283 onto a paved road running S of Brinkman, looking SW toward the Reed area, and toward a stunning, sculpted supercell.

Tornadic Stages

While admiring the structure, I spotted something tubular emerging leftward (southward) from either within or behind a rain core under the base. Donna shouted over the wind, “Hey dad, is that a tornado?” I shouted back “Yes!” and managed to snap just one photo of the serpentine vortex (alas, with the 24-70 mm glass still attached…here’s a cropped version) before I reached into the car for the zoom lens. Time was 0004 Z. By the time I got the 300-mm lens on, the little tornado was gone, the area where it had been exhibiting only a scuddy lowering and some precip filaments. I don’t know how long the tornado existed before it popped out of the murk, but can’t imagine more than a minute or two. I called it in to the WFO, advising that the tornado had dissipated. [A couple of subsequent attempts to call during later events would be met with busy signals.]

Remarkably, this was Donna’s first tornado on a chase! She soon would add two more. Donna had been on 15-20 tornado-free storm intercepts with me over the years, and had seen three tornadoes while not chasing.
Staying in the same spot, we let the storm approach rather uneventfully, watching one more non-tornadic occlusion occur, then decided to head back east and gain more distance for structure shots. As I drove, Donna and I (she with direct sight, I via rear-view mirror) each noticed a smooth lowering forming in a somewhat rain-wrapped mesocyclone to the distant WNW. We turned around and pulled over at the first safe vantage, 5 E of Willow OK, right alongside Bruce Haynie and his chase partner Matt from LBB. The lowering was a funnel that rapidly became apparent as a tornado. Time was 0029 Z.

The condensation tube fattened into a tilted, tapered cone, while the clear slot eroded more ambient cloud material and a core dump grew to pseudo-tornadic form elsewhere in the mesocyclone area. A real tornado and a lookalike, all in the same view! Here was a 300-mm zoom at 0029 Z, seconds before the tornado appeared to dissipate.

Dense precip filled the entire mesocyclone below cloud base, and we started heading E again. We were just half a mile W of OK-6 and 7 N of Granite when another lowering showed up in the rain–tornado 3. This time, contrast was very poor, as was my attempt to photograph it (see deeply enhanced version). Time was 0039 Z.

Better vantages were had from both closer and farther away, and more to the NE. At this moment, I was located in that netherworld between close enough for a good shot of the tornado, and far enough to pull out structure. Sometimes a storm observer’s timing is off that way, but I’m not complaining…Donna got to see her third tornado of the day. Shortly after the tornado roped out (within a minute), we noticed a suspicious cloud lowering deeper into the precip, probably in an older occlusion. The feature was just too distant and low-contrast, beyond intervening trees, to determine its nature (severely enhanced crop).

Post-tornadic Period

On the way to Retrop, we stopped to view the majestic and now non-tornadic storm, exuding ghostly pastels in early twilight, here at wide angle looking NW with a mobile radar that wasn’t scanning. When we turned back onto OK-6 to head N, we saw that the radar truck was parked smack in the traffic lane–since then I’ve learned that they were broken down in that spot instead of stopped intentionally.

We stopped one last time, a few miles E of Retrop, to watch the storm go elevated and weaken in the deepening twilight. We were satisfied beyond measure with our first chase of the season, and fortunate to have experienced such a phenomenal storm with minimal hassle. We managed to avoid the worst of the chaser hordes, and saw generally safe behavior even in traffic.

Given the late hour by the time we reached the next sizable town (Cordell), celebratory steak dinner would have to wait until the next day. We did, however, enjoy some Sonic food, followed by a little more dad-and-daughter time on the couple hours’ drive back home.

[EDIT] Post-chase, I learned that my camera clock was 6 minutes slow. The clock has been reset, and the times above corrected.

November to Remember

November 13, 2011 by · 2 Comments
Filed under: Summary 

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.

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