Spring 2011 Grand Finale: A Tornado-fest
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.
Long Storm Day, Amazing Storm Night
NE Colorado and SW Nebraska
19 June 11
SHORT: Observed high-based, nondescript storms in eastern Colorado, pretty supercell that got undercut by outflow NW of Wray, and messy CL-HP storm between Benkelman-MCK-Cambridge NE. Spectacular nighttime lightning and storm-structure show at Alma NE with two supercells.
LONG: Starting the day in ITR, we had a pick of two nearly equidistant targets, both in very favorable shear for supercells:
1. The higher terrain of central Colorado to our W, more certain for initiation and more moist than yesterday.
2. An outflow boundary over SW Nebraska and NW Kansas, loaded with right moisture but also uncertain on position and timing of storm potential, if any.
The decision was tough. After looking at observational data of many kinds, I still was undecided but leaning W. High-resolution, convection-allowing models started showing meatballs of high reflectivity evolving from early convection rolling off the Front Range foothills, and fairly consistently from hour to hour. We went that way, careful not to get totally out of reach of the other area, should it go.
An early cell formed off the E end of the Cheyenne Ridge and moved E across the SW part of the Nebraska Panhandle, within reach but outside either forecast area. Even though we could see the anvil storm to our distant NNW, and it started acquiring supercellular characteristics in reflectivity and SRM displays, we stayed the course.
Even though the western area ultimately didn’t pan out, it’s a good thing we didn’t go after the first storm up north–it would have put us out of position for an amazing nighttime show we never saw coming.
Yes, the western storms never got organized. Mike Umscheid and Jay Antle joined us for a spell NW of Last Chance to shoot the breeze in the breeze, bemoaning the disorganized nature of initially promising storms that had erupted to our W. Many times I’ve seen high-based “junkus” storms in eastern Colorado, streaming mammatus and virga, their updraft regions looking like fuzzy rubbish, eventually develop into tremendous supercells. This time, they weren’t.
Deep convective towers formed in the differential-heating zone under their collective anvil edge to our S, SE and ESE, including some big ones developing where the anvil edge passed over the old outflow boundary to our distant E (near the KS/CO/NEb border confluence). They kept thickening and growing until we couldn’t stand it anymore. The models were well-past due for the Colorado meatball that wasn’t to be. The models failed. We threw in the towel on area #1 and headed E in effort to salvage area #2.
By the time we neared the familiar town of Yuma, a big, visually beautiful storm had formed from the towers still to our E, and a deep, supercellular radar echo showed up NE of Wray. As we approached the storm and Wray, we had to stop briefly for this shot looking NE, the robust updraft structure rocketing aloft through clean blue-sky surroundings.
On radar, another supercell had formed in Nebraska to this storm’s E, quickly developing a hook echo. The first one being closer, we headed through Wray to take a look. Unfortunately, the choppy terrain of the Republican River drainage (which always seemed higher than the road on its N side, where the storm was) seldom allowed us a view under the base. By the time we reached the Haigler, NEb area and could get glimpses beneath the storm, we saw a ragged wall cloud but experienced a cold N wind. Outflow! The eastern supercell had spewed a big rear-flank outflow pool that already was blasting past us, and definitely undercutting the near storm.
This mean we had to keep going even farther E, and attempt to intercept the second supercell before dark. On radar the hook looked phenomenal. Tornado warnings blanketed the storm, but in the late-afternoon light, all we saw was dark, slate-gray murk to our NE from down in the valley. While approaching Benkelman from the WSW, with occasional glances between the hills and tall cottonwoods to our NE, we finally saw the cloud base–a large, bowl-shaped lowering, and then, a smooth, tapered tube extending toward the ground! Alas, we had to keep driving to get closer, as contrast was terrible from that distance and viewing angle. This turned out to be a short-lived tornado, very photogenic from a few perspectives other than ours; but we got no pictures of it.
We didn’t see the next brief tornado NNW of MCK, probably due to buildings and other visual obstructions during our brief passage through the W side of town. Feet still on the pedal, we turned N out of MCK, finally in position to see the storm from its inflow region for a few minutes before it blasted past. N of MCK, we stopped to see that the storm clearly had cycled out of its tornadic phase, shooting outflow past us and past its once productive mesocyclone region. I was just relieved to get out of the vehicle and stand for a few minutes!
We headed back down through MCK and E of town, encountering the first really dense concentration of chasers I had seen the whole vacation. Most were well-behaved. Still, it only takes a few morons opening doors into traffic, parking halfway into the traffic lanes, and pulling out into the highway without signaling and at dangerously slow speeds, to heighten tension and create unsafe experiences for everyone. I did a lot of honking and, I must admit, played a little “finger music” in the direction of some of the thoughtless dipwads.
The storm itself, a ragged mess charging toward us and right behind us as we rolled ENE on US-34, almost became an afterthought, as we dodged needless human-caused traffic hazards. [Others had it worse. A tour driver later told me that some sadistic yokel in front of them deliberately drove 20-25 mph in a 55-mph zone for several miles, visibly laughing at and mocking them the whole time.]
I was on edge, and ready to blow this whole ordeal off. Fortunately, darkness started to set in, further motivating us to bail S, out of the way, and search for lodging and fuel. One final observational stop S of Cambridge to view the HP mess to our WNW, and we called it a night (or so we thought). Enough was enough.
Heading E through the southern Nebraska night, we hit town after town that had rolled up its sidewalks for the night, all services closed, no petrol or lodging to be found. Finally we reached Alma, tired, irritable and frustrated after a long day, needle nearly on “E”, having had nothing for dinner but snack food, the last few hours spent mostly stern-chasing or being chased by a difficult, messy, tornado-warned storm, without seeing much except for occasional dumb drivers. Regrettably, I was neither the most clued-in nor the friendliest person to be around at that time. The good news is that fortunes would change for the better very soon.
We noticed a locally run motel, of the sort we prefer against the national chains for their personal service, charm and generally lower cost, this one with only one vehicle there. Fortunately the proprietor’s wife still was awake; in fact, from elsewhere in town she saw us arrive and drove over to check us into a big room with a king bed.
As we unloaded the vehicle, lightning flashes from our old storm increased in intensity to the WNW. Radar examination confirmed that it still was a supercell, headed on an easterly path toward our near-north. A quick check of profiler and VAD winds told me the storm had latched onto the low-level jet and would persist for awhile. Even as tired as we were, the lightning-viewing and photography opportunity was irresistible.
We parked next to a plowed field off the NW edge of town as the formerly messy and ugly supercell spun into view as a dazzling, spinning wonder of electric light and swirled cloud sculpture. All our tension and exhaustion vanished effortlessly, replaced by enraptured wonderment. For a brief time, someone (we later found out it was our friend Brian Morganti) cast headlights across the field, which didn’t bother me since it illuminated the foreground in an interesting way as well.
After spending an hour or so in the presence of that gorgeous sky spectacle, we watched it fling two arcus clouds overhead, blocking view of the best structures, then turn somewhat leftward and weaken. We headed back to the motel and got ready for bed, finally satisfied with this chase day.
As I was looking over some final data for determining the next day’s target (which looked to be very near where we were!), a last-minute radar check showed another supercell had formed on the southern end of a short line of storms to our WNW. It was headed on almost an identical path as the first! Quickly glancing outside, we saw distant but frequent flashes. Could it be? Could we get another amazing light and structure show?
The clock already had turned to the date of June 20. It was after midnight, and we needed to get to sleep and get some breakfast in the morning. It was so tempting to fall face first into the pillow and ignore the call of the strobing sky. Another glance outside: the light show was closer and brighter and strobing even more frequently than the first storm had from the same indirect view. We knew what to do.
One o’clock a.m. found us next to another field on the NW side of town, camera on tripod, nighttime supercell number two whirling its way across the sky, bathed in almost continuous, flickering illumination from its own relentless lightning engine. Wow. To be gifted in this way was a blessing beyond measure. Nobody else was out there this time; we had this one all to ourselves. As the brilliant display scooted by to the NW and N, a carpet of thousands of blinking fireflies rose from a grassy part of the field.
This experience, in total, was unbelievable. I shot dozens and dozens of photos of both storms, every last one interlaced with filamentous tendrils of in-cloud, cloud-to-cloud and cloud-to-air lightning. Of these, seven have been selected at somewhat larger resolution for a special web page devoted just to this night.
We slept very well after returning to the room, finally at ease and completely contented. One more incredible chase day awaited on what already was among the most spectacular and rewarding Great Pains vacations I’ve had.
A Real Stretch
Okeene and Karns, OK
23 May 11
SHORT: Observed small tornado W of Okeene OK and nontornadic supercell E of Greenfield OK.
LONG:
This “day before the day” heralded the beginning of the long-advertised “undercutting Pacific jet”, and impingement of a strong, broadly cyclonically curved upper wind max over the southwestern CONUS as a 500-mb cyclone closed over the Pacific NW. I much prefer patterns like this for observable supercells than closed, stationary to retreating northern-Plains lows like we had just seen.
A strongly difluent upper height pattern spread over the southern High Plains late in the afternoon with subtle height falls occurring across much of the region. The presence of a dryline that was
1. Beneath those height falls and
2. Bounding the west rim of a rich moist sector (at least over the TX portion)
…was a high-confidence scenario, the specifics being maxima in low-level lift versus strength of capping into evening.
Accordingly, Jack Beven and I, in caravan with DF’s “Dude, Three Chicks and a Dog” chase team, headed W on I-40 to await storm initiation along the dryline in a strongly heated and increasingly moist air mass.
Along with Howie Bluestein, Dan Dawson, Jeff Snyder and other scientists and students accompanying OU mobile radars, we waited and shopped at the Cherokee tribal store on I-40 near Calumet, until echoes appeared to our SW, W and NW. We parted with the OU crews, briefly stopped to watch some high-based junk SW of Watonga, then targeted the much more healthy Fairview/Okeene storm.
In fact, the storms SW of Watonga were everything but photogenic; and we still were in transit northward Okeene when we caught a view of a suspicious lowering under the emerging base W of Okeene. In a rare event for me, my first photos on this day therefore were of a tornado!
By 1618 CDT, when we pulled over along a section road 3 S Okeene, the lowering had become a well-defined funnel cloud about 5 NW of us or ~4 W Okeene. It was tilted nearly horizontally (wide-angle with foreground storm structure), and already tornadic based in dust-whirl reports by closer observers. Time was 1618 CDT. The newer updraft base almost overhead seemed to be the next candidate for a mesocyclone formation/occlusion process; but it actually moved N and got absorbed into the forward flank, vanishing in the process.
Meanwhile, we witnessed, photographed and reported the 6-minute tornado from the same vantage as a debris cloud became more and more apparent (unenhanced and super-enhanced photo). Shortly before the tornado dissipated, the debris cloud got displaced astonishingly far S of where the condensation funnel met the cloud base. Clearly the stretching term of the vorticity equation was at play here.
We stayed with the storm for about 45 more minutes just E of Okeene as another small thunderstorm formed to its S, moved over us with frog-strangling rain and closely slamming CGs, then merged into the main updraft region. This pathetic state of affairs left the supercell demolished as a discrete entity. What was left merged into a massive multicellular morass extending some 70 miles E-W across the area. Now what?
Onboard radar feeds tempted us intensely with displays of a solitary supercell about 75 miles to our S near Gotebo, and there was plenty of daylight to head down there and spend some quality time with that storm before dark. Off we went, photographing a smaller cell to our SSW over Watonga. (which would become the supercell E of Greenfield) and later a distant presentation of the convective mass we had left.
That Watonga storm looked rather innocuous as we passed under its early updraft base in and S of town. However, by the time we reached Greenfield and around to the S side, the convection grew explosively into a full-blown young supercell with bright, hard-looking updraft towers boiling up the back side. The upward eruption of the convection easily was visible in real-time via our eyeballs, as was the onset of helical turning in the midlevels, white turrets and cauliflower tops rocketing skyward and veering rightward like daddy likes to see.
We didn’t intercept this storm; it intercepted us. The supercell blossomed right besides us on the way S, in an environment not seeming too different from more mature supercell to which we had been aimed; so we diverted from plan, maneuvering the backroads NE of Karns into the near-inflow region of the Greenfield storm instead. Its first mesocyclonic occlusion attempt happened just to our NNW with a well-defined, if elongated, wall cloud that rotated only slowly. Rotation tightened considerably after the mesocyclone became deeply occluded, slotted and nearly cut-off from the rest of the storm, having been kicked way back out the NW side of the storm. Alas, loss of buoyancy overcame stretching; and the circulation perished.
After that, several areas of weak-moderate rotation materialized along an increasingly elongated cyclonic-shear and convergence zone; but the supercell itself was getting weaker and more strung out. We left it and headed S on US-81 through El Reno, once again headed for the initially intended supercell still a little over an hour S of us; but that storm died before we got past Tuttle. Little did Jack and I realize we were crossing the path that a certifiably violent and deadly wedge tornado would take the following day.
We enjoyed seeing Jim Leonard in the field as well as the aforementioned OU folks, and had a fine dinner in Norman with Matt Crowther, Betsy Abrams, Greg Stumpf, and my beautiful bride Elke, who couldn’t chase on this day. It was a fine and fitting end of the “day before the day” setup. What a wild, frightening, intense, and historic day the “day after the day before the day” would turn out to be…