Spring 2011 Grand Finale: A Tornado-fest
Filed under: Summary
NW KS to south-central NEb
20 June 11
SHORT: Food, fishing, baby-bird rescue and a bunch of tornadoes…on final chase day of the vacation and season for us, with three tornadic supercells in northern KS and southern NEb.
LONG: Awakening to a windy, moist, scuddy morning in Alma, NEb, beneath a rip-roaring ENEly low-level jet, Elke and I knew this could be a productive storm day, but had no idea that it would land in the top few of our entire storm-observing careers. Indeed, if you include the calendar day–having witnessed the second of two spectacular, lightning-illuminated supercells after the stroke of midnight (story here), there is no question that his goes down as an all-time top-5-class chase day for either of us.
Pre-storm
After looking at morning charts, I targeted two plays:
1. Mid-day tornado potential in the “bent back” region of the occluding surface frontal zone, W of the dryline and near the surface low. Even by mid-morning, this regime was taking shape in west-central KS and moving directly N toward us, with only some diurnal heating and a storm needed to engage intercept mode.
2. Late-afternoon potential on the nose of the dry punch, near the dryline/warm-frontal triple point, over east-central or SE NEb. This is the regime I had in mind for a couple of days, but forecast backing of flow with height in the midlevels (a harbinger of linear storm modes) had me concerned.
Obviously, given where we were, #1 was a no-brainer as first choice, despite my historically lame fortune with “cold core” supercell regimes. If that option either busted or died out early enough in the afternoon, the rather slow eastward component of the deep-layer cyclone’s motion meant we could blast east, preferably on a road suited to it like I-80, and intercept the dryline storms.
With that strategic concept in mind, and a lack of food options in Alma, we headed for HDE to eat late breakfast/early lunch, then to a nearby city park to bide some time reading (Elke) and fishing (me) before storms went up.
I didn’t get too many casts into the lake because of a sad sight I found underneath a tree: two dead baby robins, blown out of their nests by one of last night’s supercells, and one still alive and shivering with hypothermia. After some deliberation about what to do, we noticed other robins and nests up the tree. Elke, who has a longstanding soft spot for baby birds, warmed the featherless little critter while I shimmied up the tree in search of a suitable nest in which to place the orphan. We got it in a snug nest (albeit alongside a much larger and older baby), hoping its new sibling could keep it warm and the new mama would feed it. Chances are it didn’t survive; but we tried.
First tornadic phase: “Long Island/Stamford” supercell
During the avian-rescue experience, a storm had formed (early, as cold-core storms often do) and quickly had become supercellular near HLC. By the time I got a good radar read on it, the storm already was tornado-warned. Though it was moving our way, we still were in HDE, well to its NNE, so…back S through Alma we went, and across the KS line. Mike U already had seen his festival of tornadoes by the time we caught the storm S of Long Island KS, but it was far from done.
Terrain in the area was somewhat choppy and frustrating to navigate, so we settled for the first decent hilltop view we could get, 3 S of Long Island. The supercell was moving toward the N and NNE at various times, with dark murk inside, a tall precip cascade on its SE (rear-flank) edge, and clear, blue sky to its E (our SE). Surface winds blew from the ENE to NE, as they would throughout the duration of our engagement with this supercell. We and the storm were a little leftward of the track of the surface low!
In the murk–and curiously, in the forward-flank interface region ahead of the main mesocyclone, we saw a small, tightly rotating wall cloud emerge, with a pencil-shaped tornado dangling beneath (photo: as seen and super-enhanced versions).
The tornado lasted about three minutes and dissipated, before a different, seemingly shallow, front-flank mesocirculation started spinning like mad to our W. That planted a dusty multivortex, which also was low-contrast (photo: as seen and super-enhanced versions). Whoa! I had based our intercept positioning, relative to the supercell, on the likely track of the primary mesocyclone, which stuck out eastward from the SE side of the north-moving storm.
By now, I had figured out what was going on, but that didn’t make it any less surreal. Pearls of enhanced rotation were forming and spawning front-flank tornadoes, along a necklace of very rich vorticity characterizing the inflow-outflow interface. A conceptual model of the situation looks something like this 2-D cartoon. Why this supercell was going nuts with front-flank mesocirculations, whilst most others don’t, is a question I’ll leave to the numerical modelers for the time being. In the real world of a storm intercept, this presented a strategic quandary, in that getting closer to the front-flank tornadic necklace also meant getting in the path of a rain-wrapped HP mesocyclone of a fairly fast-moving supercell.
As the second tornado churned northward, in step with storm translation, another suspicious feature caught our attention (Elke actually saw it first). A wide view of the storm (photo: as seen) shows the precip-wrapped, main mesocyclone to the left, and at far right, the dusty multivortex. Right before taking that shot, we spotted a dark, smooth, persistent, and reasonably wide lowering in another area of front-flank rotation, buried somewhat back into a precip-filled notch. That made ground contact, with rapid rotation of cloud material above and around the tapered-barrel shaped tornado. We had two ongoing, plus one that likely was underway in the main mesocyclone but not yet visible. More on that beast later. As for the two we knew, the arrows point to the visible tornadoes in this super-enhanced/zoomed version of the last shot.
We had a peculiar situation at hand.
After a few minutes, we lost sight of the southern front-flank tornado as it buried itself in precip, while the leading one narrowed and proceeded toward the N. We headed N too, crossing the KS/NEb state line about the same time as the leading tornado to our W (photo: as seen and super-enhanced versions).
Once that dissipated, we still had an original, dominant mesocyclone to our SSW, in which we couldn’t see anything thanks to persistent, rotating moat of heavy precip that cloaked the mysterious tempests of danger lurking within. This situation was getting weirder all the time, and was about to become truly bizarre.
I drove through Orleans and a few miles NW on US-136, which angled us closer to the front flank and somewhat in the path of the big meso. Lo and behold, just ahead of the rain-wrapped main meso, a tall, skinny, dusty tornado came into view to our WSW (photo: as seen and super-enhanced versions). This definitely was separate from the previous tornado, and probably just S of the KS/NEb state line. Meanwhile, a new and relatively robust shear-zone updraft to our NW (separate from the dissipated dusty tornado #2) started spinning frantically, and beneath a shallow, bowl-shaped and rapidly rotating lowering, spun up another short-lived, dusty tornado (photo: as seen and super-enhanced versions)! After the latter tornado dissipated, the prior, dusty tube seemed to spin down gradually instead of roping out, as if it simply lost its will to rotate.
Whither the main meso? At long last, we started seeing the answer as a rapidly rotating, nearly ground-to-anvil column of rain and hail churned toward us. Something very menacing, dangerous and unsavory began to appear from within the whirling dungeon of heavy precip–a big fat tornado (photo: as seen and super-enhanced versions). Look behind and above the tree row. I think what we’re seeing here is not just the rain-wrapped low levels of the tornado (dark wedge below cloud base, with helical scud coiling about).
Also, note the convective column containing the tornadic circulation (and not much larger in width than the visible tornado down low!) bending above and to the right. This is NWward with height on a N-moving storm, looking SW. [Conceptually, turn your usual NE-tilt on an E-moving storm leftward 90 deg as in the 2-D cartoon ]. In essence, you’re seeing the tornado-cyclone from ground into the mid-upper levels of the storm, visually. Yes, it was convective-looking, but corkscrewing pretty fast visually. Alas, even the mid-upper part didn’t shed its cloak of rotating rain curtains for very long; mostly it had been a bear’s cage from ground almost to anvil, for much of this storm’s lifespan in my view. I’m glad the curtains parted just long enough to reveal this fascinating deep-layer structure–and of course the hefty hose beneath.
My question: Was this the continuation of the Mr. Umscheid’s wedge from way down by HLC, or a separate tornado? Some shots by Walker Ashley seem to indicate a smaller barrel====>cone tornado earlier in this meso’s lifespan, and farther SW in KS. If so, either
1. Walker;s tornado expanded again to a rain-wrapped wedge shown here, or
2. This was a new one.
Whatever the case, the main-meso tornado likely had been ongoing for a long time, given that we had observed tremendously rotating rain curtains around the area for many minutes. This clearly was a very large, well-formed and mature tornadic vortex by the time we finally could see it. The entire tilted cloud column was rotating rapidly.
Wrapping precip again obscured the tornado within two minutes, or about the time it crossed into Nebraska. Orbiting rain curtains continued around the mesocyclone for several miles N toward Stamford an perhaps beyond, until the entire supercell evaporated from below and died W of HDE.
I read reports of “skipping” tornado paths with this storm in this area, which is bogus on two fronts:
-
1. By definition, a tornado cannot “skip”. If it’s not on the ground, it’s not a tornado.
2. Semantics aside, there simply was no “skipping”. The various different tornadoes in this area near the border, lined up similarly, probably gave the illusion of “skipping” of damage.
After the initial storm died, we got fuel in HDE and then couldn’t flank the downshear Elm Creek storm. We knew it was tornadic based on spotter reports and the SRM signature, but it was planted squarely on the highway to our N, near I-80. The first storm had put us out of position to see the business end of the Elm Creek supercell, so we jumped on the Interstate with its 75 mph speed limit and pressed the pedal hard in an eastward run for the second target area.
Second tornadic phase: “Hampton and Bradshaw/Stromsburg” supercells
Visually, a series of deep, glaciating towers to our ENE-E-SE looked reachable and was growing. By the time we passed the HSI/GRI exit, an unbroken wall of dense cores loomed to the E on radar, their convective towers lit by a blend of direct and filtered sunlight. My hope was that, despite the linear mode, a “tail-end Charlie” would roll up toward I-80 after I could penetrate the line and get into the inflow air. Linear storms don’t tend to hurl gorilla hail; so I was at ease with cruising up to the back and shooting through a relative gap.
That’s exactly what we did, except that the southern part of the line was breaking up into more discrete (and disturbingly, rotating) cells right as we started the penetration. We took a pounding from marginally severe hail, gazing southward through precip to see if anything could show up in the nearest area of rotation S of the Interstate. As we cleared precip and a ragged base came into view adjacent to the core, Elke saw a brief needle funnel 4/5 of the way to the ground. That might have been a tornado; though flooded fields precluded appreciable dust generation. No debris was visible beneath.
As we neared the Hampton exit, another core loomed to the SSE, moving N. We continued to press E, getting pounded by still more hail. Clearly the line had broken up into closely-packed supercells and we needed to get out of their way! A few minutes after we cleared the N side of the intensifying precip area, I glanced behind us to see a barrel-shaped, rain-wrapped tornado in the S part of the same core, about to cross the Interstate (photo: as seen and super-enhanced versions). That was a little too close for comfort, though we really had about 5 minutes’ cushion. I pulled off the road, jumped out, and gestured wildly at some westbound traffic not to go that way. Fortunately, they slowed down and pulled aside.
What appeared to be a big, low-visibility and significant tornado (as it turned out to be!) was almost upon the Interstate (photo: as seen and super-enhanced versions), and I was hoping nobody would drive into it. Enough precip wrapped around the tornado that we couldn’t see it with our eyeballs as it crossed I-80 (photo: as seen and super-enhanced versions), though it narrowed somewhat to a stilted stovepipe and became more visible again between I-80 and US-34 (photo: as seen and super-enhanced versions).
The Hampton tornado appeared to hook NNW and move away from us. Our last view of it (photo: as seen and super-enhanced versions) came with a troubling realization: we still were getting peppered with precip, including increasingly large hail! The real tail-end Charlie still hadn’t reached I-80 yet; and indeed, another core was moving overhead with a low base diffusely visible to our SSE. Time to high-tail it east again! As we pondered getting off the Interstate at the Bradshaw exit, Elke looked out and up to see rapid cloud-base rotation nearly overhead, atop that very exit. We kept going!
Behind and slightly leftward of us, the tornado first appeared in the rear-view mirror while driving out from under the meso. A small dust plume spun up just N of I-80. Above that loomed a rotating cone funnel that extended about 1/3 down from cloud base. We zipped a mile or so E, then pulled safely off the road to watch. This tornado was highly visible and quite photogenic, a marvelously sheathed column into which the condensation funnel seemed to poke, spike-like. “Finally,” I thought, “all these tornadoes today and we have a high-contrast specimen!” I said something more coarse, but fortunately, cannot recall precisely what.
Without an immediately available north road, we watched for a few minutes as the tube widened and retreated northward away from us, a wide-angle view revealing more of the tail-end supercell’s swirly updraft structure. Although rather distant, we had the tornado in view all the way through JYR and up US-81 to a point 4 ESE of Polk, where we pulled over briefly to watch it rope out to the WNW. This was our longest continuous view of any of the day’s tornadoes: 18 minutes.
A new lowered base even farther N told me this storm wasn’t through with cyclic tornado production yet. As it was moving N rather quickly, slightly ahead of abeam to port side, the town of Stromsburg and its inevitable slowdown dead ahead, we had to get moving for any hope of seeing the next hose. A few miles S of Stromsburg, we saw the newest and last tornado of our day emerge from the haze, to our NW.
Of course, traffic slowed to a crawl in town, a chain of cars inching N at about half the posted 25 mph speed limit, some slowing down or turning indecisively as if thoroughly bewildered. Townsfolk stood in at least half the yards gazing in various skyward directions, not sheltered, despite the ominous wail of storm sirens. I thought, “They’re safe and don’t realize it yet; but if the tornado were headed into town, we would have multiple casualties amongst all these unprepared and confused citizens”. What I actually said might have been a tad less civilized, so it’s good that I can’t recall that.
By the time we got extricated from Stromsburg and headed N for a few miles, contrast improved enough to pull W half a mile and get a few decent shots, including this one looking NW across a corn field at the stout, grinding vortex. Motion of the ragged cloud base around the top of the visible tornado was impressively speedy. Driving a few more miles N on US-81, we finally got roughly abeam of the tornado again, only to see it rapidly narrow and then rope out.
Just in case the storm would cycle once more, we headed up an unmarked road off the east bend of US-81, in the general direction of Duncan. Alas, the supercell quickly displayed a rain-wrapped, outflow-dominant structure, and would produce no more tornadoes. We turned around to head back to JYR, photograph a couple of elevated cells (looking E and looking N from the S side of JYR), grab a room, and get some celebratory steak dinner before restaurants began to close.
Epilogue
A hearty meal was in order too. During a long storm-intercept day, we successfully had observed at least 8 and perhaps up to 10 tornadoes, from three different supercells, in two separate forecast targets and meteorological regimes. All I can say is, wow…only 3 May 1999 clearly exceeds this for my one-day tornado total. We don’t chase just to see tornadoes–far from it, actually–but you bet we’re appreciative of them for their rarity, uniqueness and power–the dichotomously ironic “Beauty of Atmospheric Violence” that is the title for my storm-photography shows. Best of all, nobody was injured through all the whirling mayhem of the day.
It was an amazing grand finale to an unprecedentedly bountiful 2011 Great Plains severe-storm vacation (and season)!
I had called in several of the tornadoes as soon as safety and cell signals would allow, a few while they still were underway. Within a couple weeks after we returned, I processed the day’s images (before all others from this vacation) and sent an itemized table of tornado times and estimated locations to the affected WFOs, with embedded links to many of the same photos as above. That table includes times, locations and links to the above photos. The tornado log file is in the public domain, and linked here in MS Excel format, freely accessible for anyone interested.
Central Oklahoma Tornado Outbreak
El Reno/Piedmont, OK EF5 with Satellite Tornado
Dale, OK EF1 Tornado
24 May 11
SHORT: Intercepted tornadic supercells NW and E of OKC, the first with a violent tornado in progress, the second offering a scenic rope-out.
LONG:
Welcome to a “High Risk” outlook and “Particularly Dangerous Situation” watch scenario that verified, weather-wise, exactly as such for central Oklahoma: in summary, three different violent (EF4+) tornadoes arose beneath three different supercells, with a fourth big tornado rated EF3 in northwestern Oklahoma (NWS Summary). Through both skill and luck, we witnessed what has been rated as the biggest and baddest tornado of the lot; yet we are respectfully mindful of the human toll that it took in spite of absolutely outstanding forecasts and warnings.
This almost classical Southern Plains tornado outbreak was so well-forecast and so thoroughly handled by SPC, local offices, local media and EMs, that I’ll eschew discussing meteorological details, offer a few prototypical 21Z (4 p.m.) mesoanalysis graphics that pretty much speak for themselves…
…and now go straight to “the chase”. And what a “chase” it was, right into the area of maximized parameters you see on those linked mesoanalysis graphics, and at about that time.
Phase 1: Intercepting the Piedmont Supercell
After looking at some data at home, and at Ryan Jewell’s house, Jack Beven and I targeted the area near and just N of I-40 in west-central OK, mindful of the likely fast storm motions of the day and the need not to get too close, to soon, to developing storms. As we headed W on the big slab, the earliest cell of consequence erupted SW of Fairview, not too far from the previous day’s tornadic intercept. Indeed, though we didn’t target the storm due to incompatible relative motion vectors of it and us, it would produce a couple of tornadoes over and near Canton Lake.
Storms were forming closer to each other than I like, causing some interference and precip-ingestion problems. We waited just E of Watonga for the next supercell in a broken band of them, hoping to get a quick look while ultimately targeting the southern storm in the same grouping–the storm that would become the El Reno/Piedmont supercell. A quick jog back W to the fringes of Watonga, as the storm passed, revealed an outflow-dominant heap; so we flipped the vehicle back eastward, heading for Kingfisher and the next decision point.
As we got to Kingfisher, the big deliberation was: wait for the storm E of town on a good E-W road and risk that it would right-move to the morass of stoplights and traffic of Guthrie, or head S on US-81 to Okarche and risk munching some of the forward-flank hail along the way?
The radio station was blaring frantic TV simulcast reports of a “wedge” headed for El Reno. We vacillated for a couple of minutes, and I had my doubts; but Navigator Jack’s front-of-the-map calculations convinced me we could pull it off. We headed S toward Okarche into dreadfully darkening murk, intensifying rain, and ultimately, some hail, while hearing of the same “wedge” crossing I-40. Often such tornado descriptions are exaggerated; but I knew that, on this day, violent, large, and long-track tornadoes certainly could happen. Unknown to us, at the time, the tornado was sideswiping the El Reno Oklahoma Mesonet site with an 18-mb pressure drop and measured gusts to 151 mph–the strongest winds yet clocked by that network of weather stations.
Rounding the SE turn onto OK-3, we vectored an intercept position for any tornado coming NE out of El Reno. Blistering barrages of close CGs hammered the ground all around us, a fusillade so furious that I pulled my radar-delivering I-Phone out of the car jack, and we refrained from touching anything metal. A few hailstones clunked off the roof–none ultimately large enough to do damage, though we did see stones around two inches in diameter bounding off the road. The really huge and destructive hail was no more than a couple of miles to our S and SW; we had left Kingfisher in the nick of time to get around it!
We pulled S off OK-3 at Cimarron Road, about 5 WSW Piedmont, and drove S about a mile to a fine hilltop vantage. CG activity was backing off a lot, and we were (for now) out of precip. I could commence photography in relative safety. It was so stinking dark under that storm that I had to crank the ISO up to 1600 just to hand-hold shots with 1/25-1/60 sec shutter speed at f2-f4! At a time like this, I was so thankful for having invested in a top-end Canon DSLR and the L-series glass on the front. Using lesser equipment and especially with my old slide camera (which usually contained 100 ASA film), successful collection of the following shots would have been impossible.
And so we waited, looking along a lengthy cloud base from W-SW, footed by some dark murk well to our SW. We knew where the tornado was from the constant TV reports–buried in that murk–but couldn’t quite see it yet with our eyeballs. In fact, it was only after I took this 34-mm shot at 1630 CDT, then looked at the viewfinder presentation of it, that I finally could ascertain the outline of the tornado embedded in that murk to our SW (severely enhanced crop of same photo)! It was moving NE (toward us) at 40-50 mph. We had several minutes to hold position before having to decide whether to jog S on our paved, N-S road to get out of its way.
At first a multivortex containing a fat, tilted stovepipe, the tornado took on a wider configuration with a fat barrel and adjoining cone being two of the more persistent, larger tornadic vortices involved. Even at that distance, we began to make out wild cloud motions and rapid revolution of vortices around each other. The barrel temporarily vanished at 1632 CDT to reveal a fat stovepipe within an obviously significant, broader tornadic circulation.
Despite all the precip evident to the left (SW through SE) of the tornado cyclone, it maintained enough of a weak-echo moat around its immediate vicinity that our view kept getting better and better. The tornado also was growing larger as it got closer, closing in fast, not moving much right or left. This meant we likely would have to bail S sometime soon. But first, more observation and photography ensued as the tornado’s form fattened into a wide, dust-flinging barrel, then a bonafide wedge. The ambient wall cloud and occlusion-downdraft slot also became more apparent, contrast and visibility continually improving for the time being. We were impressed…very impressed. I told Jack, “Congratulations…your first violent wedge tornado.” Jack has been taking chase vacations to the Great Plains since the mid-1990s, often with the most deplorable luck in weather patterns. This was a new and potent experience for him.
As this grinding behemoth drew closer, I was supremely confident in its violence, while dearly hoping nobody was sheltering above ground inside its path. [I didn’t know it at the time, but this monster had killed several folks already around I-40.] The motions in and around the tornado were of a ferocity I’ve seen, in person or on video, only with tornadoes ultimately rated F4 or F5. As the sides of the condensation wedge appeared to froth and oscillate wildly, chunks of scud materialized at ground level in incomprehensible fractions of a second and raced diagonally up the and around the vortex at breakneck speed.
Given its slight rightward translation, I was reasonably confident the tornado would miss our location–but not my much. Any rightward turn, however, and we would be in grave peril with precious little time to spare. At 1635 CDT we turned S and drove a mile. As we pulled back onto Cimarron Road, a well-defined, horizontal accessory vortex formed on the near (NE) side just above ground, coiled around the N side, and rolled vertically up the rim of the tornado. This was a new experience for me, having seen the phenomenon only on videos of violent events such as Red Rock OK (26 April 1991), Golden Gate IL (2 Jun 1990) and Tuscaloosa AL (27 Apr 2011). Had I stayed at the previous location 30 more seconds, I could have photographed that too.
As good luck would have it, the tornado took a temporary NNE jog as we rolled S, maintaining safe distance. As bad luck would have it, torrential rainfall began wrapping around the SE and E sides of the mesocyclone, thoroughly dousing me in a veritable firehose of water after I jumped out and ran into photographic position. Barely able to stand in the roaring inflow, I hoped for just a shot or two before the camera would get too wet. It grew into a very wide, menacing wedge all the while, its collar cloud blasting around the mesocyclone with amazing speed. As the tornado moved to our WNW and NW, I clearly heard its roar–a throaty, primeval rumble somewhere in pitch between the closed-mouthed growl of an angry bear and the muffled booming of continual heavy-artillery fire.
This was one bad, bad, bad mother.
I reeled off one final good shot at 1638 CDT–capturing a satellite tornado that had just emerged from behind (W of) the big one, and was orbiting around its near-SSE side, throwing up a dust plume of its own. The satellite then turned NNE in front of the main event’s E side, and became lost in worsening contrast. The last and only other satellite tornado I saw was on 3 May 1999, near Chickasha.
Within seconds, the big tornado right-turned ENE again and got so wrapped in rain that we barely could see it anymore. It crossed OK-3 just W of Cimarron Road, and as we cautiously crept N back toward OK-3, crossed Cimarron road less than a mile to our N. Needless to say, I was glad it was moving away from us, while glancing overhead and around often for more satellite vortices. Furiously wrapping rain curtains parted just enough to reveal the E edge of the condensation vortex to our near-NNE, rightward of some power flashes. This was my last clean view of any part of the tornado, at 1640 CDT.
Meanwhile, the combination of inner-edge RFD plus southern-rim inflow to the tornado was severe at our location. The forward housing for my outside rear-view mirror launched itself like a rocket off my vehicle and sailed airborne for hundreds of feet out into a field to our NE, as the vehicle shook in the gusts. We were safe (barely), but also, not inclined to go any further N for a minute or two.
Even though the tornado did miss our initial photographic location, it wasn’t by much. I’m still glad we moved…under half a mile from the edge would have been unsafely close for a certifiably violent, still-expanding, precip-wrapping monster with proved tendency for satellite tornadoes and accessory vortices writhing around its rim.
Then hit a horrifying realization-–this tornado was headed generally toward the residence of my friend (and fellow storm observer) Rocky Rascovich, N of Piedmont. I tried to call and nobody answered; fortunately, it turned out they already were in shelter. His wife assured me later that it (barely) missed them and they were OK. It was the sort of tornado–fast-moving, expanding, wrapping in rain–that is the most dangerous and hardest to observe safely.
Later news of the deaths near El Reno and Piedmont humbly counteracted any sense of gratification I had that evening at getting the good-contrast, big-wedge shots about which I had dreamed since childhood. This is the ethical paradox and dichotomy of conscience for any storm photographer.
Phase 2: Intercepting the Dale Supercell
Cruising along the mostly empty Kilpatrick Turnpike (around N OKC) we briefly debated whether to go up I-35 and meet the storm at Guthrie; but its deep precip-wrapping and messy radar appearance convinced us to jump SE for newer storms headed out of the Chickasha area. Early reports of tornadoes from those sealed the deal.
Jack and I tried to get S of Norman, but were stopped by a traffic jam on I-35 in town (flipped car unrelated to tornadoes) and couldn’t get to Goldsby readily to observe that event. Had the Goldsby tornado turned slightly more leftward and gone up I-35, it could have plowed through hundreds of stopped vehicles up and down the highway!
Instead we waited a short time near the North Base for what was left of the Newcastle storm (by then, nearly nothing), then backtracked some back roads to I-240/40. Along the way I spoke to Elke; they headed to my neighbor’s underground shelter as the Goldsby event headed for Norman. In northern Norman and along I-240/40, Jack and I encountered occasional marginal-severe hail and falling small debris (insulation, leaves, small twigs) that had been launched by the Goldsby tornado into the supercell’s far-forward flank.
The Goldsby storm also had been slammed by a left-mover, temporarily disrupting its organization, dousing the once-violent tornado before it could grind through some part of Norman. I was glad of this, as it spared a lot of destruction in the town in which I reside!
As the supercell reorganized, we vectored the new mesocyclone to cross W of Shawnee near Dale, in a mostly hilly and forested area. Fortunately I knew of a large, flat, open field just S of the I-40/OK-102 (Dale) exit, from which I had photographed the OKC ice-machine storm of 16 May 2010. We headed there and waited for the reorganizing mesocyclone region from the approaching supercell to come into view.
From the murk, at 1830 CDT, a low-hanging, conical cloud form appeared to our W, hard to see at first beyond the red farmhouse in the last shot (super-enhanced crop). This feature had good temporal continuity with what would emerge more visibly by 1832 (super-enhanced crop)–the Stella-Dale tornado, as a tilted cone beneath a deeply clear-slotted wall cloud. We weren’t totally sure yet by our eyes, even then (given the hazy conditions); but by 1833, it was obvious that a tapered cone tornado with debris fan (super-enhanced) was moving in a general ENE direction to our WNW, very close to I-40.
As the tornado grew closer, its form gradually became sharper and also more sinuous, contorting spectacularly into a long curved tube. I was so mesmerized by the wondrously serpentine evolution of the visible vortex that I didn’t think to slap on the zoom lens until the tornado roped out at 1836 CDT. What was left of the mesocyclone next moved N of us, got undercut by rain and outflow, and vanished into the murk N of I-40.
We cruised E on I-40 to look at two more supercells near Prague and Okemah; but their structure was more amorphous, with little evidence of robust low-level rotation by that time. Along the way back, we noticed mostly minor (Ef0-1) damage alongside I-40 2.5 W of the Dale exit, where the tornado crossed. The wreckage of the big rig, whose trailer got blown to pieces, still was being hitched up to a towing vehicle.
By the time we got back to Norman, we were thankful that my home (and those of others in Norman) was spared, and that we got a high-contrast view of a violent wedge…but also, once again saddened for the casualty toll from yet another deadly tornado day among far too many this year. We met up with the Fogel crew for dinner (they had far worse luck than we with tornado observing on this day), as well as Elke and my kids, swapping stories of a great chase (us), a frustrating one (DF’s crew), and another Norman scare (my family). Aside from a dollop of mental exhaustion, my other impression was: “I’m about ready for the High Plains!”
At Long Last: Birthday Tornadoes
Hickory and Ada OK
21 May 11
Prologue:
This was my birthday. I never have seen a tornado on this date before this year, despite the seemingly ideal time of year for them.
Hold on! Tornado climatology isn’t always how it may seem. For strange cosmic reasons that shall remain a cryptic mystery, that date (green in the graph below) also is an inexplicable and pronounced low-day for tornadoes in the U.S. during this time of year, as shown by Chuck Doswell in one of his research papers published in the Electronic Journal of Severe Storms Meteorology.
Click to open an enlarged version:
The Intercept:
Elke and I headed S towards the northern rim of vigorous return-flow moisture near the Red River, followed by a unique chase team consisting of David Fogel, his cousins Samara and Ellie, and Ellie’s friend Ella, and of course DF’s equine-sized Leonberger dog, Porthos. [Note: This meant I was chasing with Elke, Ella and Ellie…good times!] Ellie and Ella were first-time chasers this day, giving me hope for some “rookie luck” to overcome my “birthday curse”.
Our target area was southern OK an north TX just E of the dryline, and we settled for the middle: The Red River, heading to GVT to fuel up and await nearby development near the northern nose of the most robust return-flow moisture. On the way down, messy supercells were evident in central TX, well S and Sw of the Metroplex and out of the target area; while a discrete storm rapidly intensified just SW of FTW. A convergence zone was evident in reflectivity imagery extending N from the FTW storm past ADM. This was our hot zone for hot action.
Not wanting to intercept a storm through the Metroplex if we could help it, we held firm at GVT awaiting closer development. That move paid off; as the FTW storm quickly (and rather inexplicably, given the strong buoyancy) perished.
After fueling and getting some technical difficulties fixed with DF’s onboard electronics, we waited a few miles N of town near I-35, admiring wildflowers and convective towers–yes, newly developed moist updrafts to our near WSW and more distant N. The northern towers, even through haze rendered by smoke from Yucatan crop-burning, looked healthier and began glaciating, as viewed across the verdant North Texas savanna. We had a storm to target, brother.
As we pulled onto the I-35 slab and headed N, strong reflectivity echoes started to appear NW of ADM. Those developed quickly into a strong echo, already resembling a supercell by the time we exited the slab and headed E on OK-53. Intense towers rolled up into the back side of the storm with fantastic buoyant force, as seen looking NE from W of Gene Autry.
Zigzagging E and N toward Sulphur, we met the first hilltop base view just in time to view a funnel suspended from an older, occluded mesocyclone to our NW (and W of town). By the time I could pull over safely, the rotation already weakened, the funnel more ragged and not as low, the clear slot cutting well around the cloud-base mesocyclone area.
Focus shifted to a newer area of cloud-base rotation to the E. The storm already was tornado-warned and had been for some time. That appeared justified. This supercell was moving into a very moist, low-LCL air mass with big (and growing) 0-1 km hodographs. This already was the most promising storm I had seen on a birthday, despite some unquestionable jackassery that ensued while viewing the newer mesocyclone area. None of the scuddy, rotating lowerings to our NNE (just E of Sulphur) could tighten up much, and the storm was getting away.
We needed to reposition, despite the lack of great vantages in that hilly and intermittently forested part of the state. Haze clearly was a problem too, and I knew we needed to be close to get better contrast. Before that area of storm-scale rotation could cycle back up, we headed through town. Our bright-eyed, twentysomething supercellular newbies from New Jersey, Ellie and Ella, got serenaded by the stereophonic wail of the Sulphur sirens, offering them an ominously palpable reminder of the menacing side of springtime in Oklahoma.
About halfway E on OK-7 to OK-1, the organization improved, all right. Obligingly, the storm that had been behaving itself during our relocation grew a very broad, extensive updraft base–all of which was rotating, and rather rapidly. Within the tumultuous gyre, every lowering was spinning in its own right, the whole system a seething, cloud-base cauldron of eddies and whirls that defied ready classification. We stopped 3 SSW of Hickory (and 1 W of the OK-1 intersection) to watch its merry-go-round of distinct funnels, shallow and bowl-shaped lowerings, and at least one brief tornado.
Some vortices were more than two miles apart, others adjacent. Where is the cutoff between a broad, multiple-vortex, weakly tornadic circulation, and a multiple-funnel (or multiple-tornado) area of storm-scale rotation? This thoroughly fascinating process unfolding to our NW through N blurred the lines between any such distinctions on the spectrum of atmospheric vortices. Sometimes, it’s just not as simple as categorically declaring tornado or not!
Two of the longer-lasting, lowest-extending condensation funnels (middle and left here, looking NW) initially developed apart at 1924 CDT, within the same mesocyclone. The eastern (right) funnel retrograded almost magnetically toward the western one, intertwining with it as in a seductive love dance. The combined condensation vortex then became more laminar, less scuddy, more wavy, and produced a brief, faint puff of dust beneath (deep crop-n-zoom/enhancement), in an area of very wet ground.
By 1926, the brief tornado was gone, the area of cloud-base rotation (at left in this shot) that had hosted the small, blended tornado vortex weakened. Did you notice anything to the slightly more distant right (NNW) in the last photo? Lo and behold, another area of rotation took shape to its NNE, itself offering a ragged, conical funnel that extended more than halfway down by 1927 CDT. If this was a tornado (couldn’t determine via enhancement or independent eyewitnesses), it was separate from the other, a circulation within a circulation within a circulation. These were far from the only funnels in the storm-scale gyre in just a 10-minute span. What a gloriously complicated mess!
The broader mesocyclone soon began tightening, and we needed to get E and N again to close in for more unambiguous tornado potential. In the process, we crossed a spot of infamy–the very railroad crossing where an agonizingly slow-moving train halted John Hart and I after we saw the distant Hickory tornado of 11 May 1992. That train 19 years ago seemed to go on forever, as the supercell got away, wrapped rain around its SW hook, and produced a multivortex F4 tornado just out of sight. Today, the tracks were clear and such agony didn’t befall us. The same road we couldn’t take way back then was open for business–right here, right now.
We turned NNE on OK-1 and drove almost under the rim of a (by now) very strongly rotating and more classical mesocyclone, stopping at a spot 1.5 SE Hickory when a broad cone funnel appeared about a mile to our NE. At 1934 CDT, a brief filament of whirling condensation rocketed up from the ground beneath the cone as I was exiting the vehicle, and before I could shoot…tornado! The condensation cone soon drew lower. Sinuous, partly translucent vortex filaments materialized beneath and coiled about one another, vaporous marionettes twirled by their tornadic puppet master. By 1927, the cone retreated to a smooth cloud-base bowl, and no vortices or debris could be seen beneath.
The mesocyclone began retreating NE, so we had to zigzag E and N to maintain view as it reorganized, retreated NNE somewhat, cut a deep clear slot, and intensified again. Heading E on unmarked road “E1700” 5 E of Hickory (a variably surfaced path of gravel, dirt and crumbling, antique pavement), we were very fortunate to find another high, relatively unobstructed vantage to our NNW and N.
Just in time, too…the mesocyclone cut a deep clear slot and began twirling funnels beneath with fervor (deeply enhanced crop). For a brief interlude, the spinning cloud mass dipped its southwestern margins into golden beams of sunshine, fluidly swirling together the concepts of atmospheric violence and beauty.
The circulation seemed to plant itself on the earth, chunks of scud forming right down to the ground, ripping across the surface at tornadic speeds, interspersed with intermittent but unmistakable suction vortices–one after another, none lasting more than a few seconds, but collectively, too many to count. This was a very low, humid, multiple-vortex carousel. Sometimes two vortices could be seen interacting while scud and/or suction spots whizzed through other areas of the magnificent maelstrom.
[Some described this tornadic stage as a “wedge”, but the condensation was too ragged, sparse and ephemeral to call it that. Still, if viewed with any blockage by trees or terrain, I can see how such a mistaken description could be made.]
The last evidence of a tornado was at 1953; thereafter the cloud base rotated much more weakly and rose in height. By now, we knew of the larger, newer and stronger supercell W of Ada, but the clearest path to it up US-377 still was blocked by our weakening (yet still potentially hail-bearing) storm.
After letting that supercell pass across the highway, we had a smooth trip to Ada, barely in time to see a conical lowering below the horizon (turned out to be the end stage of its last tornado at 2035 CDT) while still driving. By the time we found a place to stop, a small and ragged funnel remained. No matter, we could marvel at the spectacular storm structure spreading across the western sky. As this storm moved NW of Ada and began weakening, assorted precip shafts cascaded from the cloud base near low-hanging scud chunks, likely yielding any remaining “funnel” or “tornado” reports.
The short but happy drive back to Norman led to a delicious dinner, steak and shrimp for the menfolk, whatever the ladies wanted, kibbles for Porthos out in their vehicle, all in a festive celebration of a fantastic storm-observing day (and for me, the clinching win on the restaurant TVs that sent the Mavericks to the NBA finals). Birthday tornadoes that didn’t hurt anybody, great storm structure, Mavs clinch a playoff series…a great, great day indeed!