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.

Spring 2011 Grand Finale: A Tornado-fest

September 9, 2011 by · Comments Off on 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.

Ice Machine in Yuma, Colorado

August 13, 2010 by · 1 Comment
Filed under: Summary 

Yuma CO, 21 Jun 10

SHORT: Observed 3 supercells ultimately merge into one over Yuma CO — damaging hail, beautiful post-storm skies.

LONG:Join us on this fine, toasty day for a tale of three supercells that became one, the hellish hailstorm that resulted, and a storm-observing couple who chased them.

Elke and I began the day in Sidney with a target area of NE Colorado, in the region of relatively backed low-level flow. We were uncertain whether the storm(s) of interest would fire on the Front Range or on a convergence boundary farther E, in somewhat more moist air SW of Sterling. The answer: yes, and yes! From Sterling, we observed the growing anvil from a storm near DEN that was high-based but starting to rotate aloft (based on radar velocity imagery), along with multiple towers bubbling just to our SW, beneath and S of the anvil canopy.

The tower at left, in the last shot, erupted into a pre-supercellular supercell, before anvil shadowing had a chance to mitigate diabatic heating of its immediate inflow layer. We dropped S to stay ahead of both this storm and the more distant and growing beast roaring out of DEN. Even in this early stage, the new storm displayed nice corkscrewing action (the base of the DEN storm becoming visible at distant rear), looking W from the N side of the Colorado Plains Regional Airport (AKO). The storm spun around for a short while, moving slowly closer to us without growing a very large updraft. Meanwhile the DEN storm churned along essentially straight toward us, with a wall cloud and lowering becoming faintly visible in the distance under its southern flank. I sensed this closer storm wasn’t long for the world.

We headed E through Yuma, taking note of potential hail shelters for four reasons:

    1. The combination of the big western storm and any merger with a foregoing supercell could spawn some healthy ice bombs,
    2. I still had a good windshield and didn’t want to bash the hell out of my new vehicle with gorilla hail this soon,
    3. We deemed it wise to plan sheltering options in case we didn’t have time to bail S of Yuma and ahead of any storm acceleration, and
    4. The next major town to the E was Wray, its S escape option (US-385) known to be under heavy construction with a surely nerve-wracking and possibly vehicle-destroying situation of one-lane, pilot-car closure for many miles!

Meanwhile, another tower went up in some slightly more strongly heated air several miles farther S (to our SW), also evolving into a skinny supercell rather quickly, and likewise coming under the sprawling and thickening anvil of the onrushing western storm. In the last shot, from just E of Yuma, the outflow-surfing updraft base of the massive western menace is visible at distant left, and its downshear anvil canopy distant right — dwarfing the nearer but much smaller supercellular plume. The older tower (spinning down to its N) eventually merged with the northern part of the newer, closer supercell as the latter expanded. Then it expanded further and assumed some sharply sculpted structure, moving slowly E and expanding its updraft still further.

One thing it did do, before being absorbed by the big bad brute impending, was glow forth an eerie, ghostly layering of light and shadow, interspersed with subtle pastel hues, a weird sight that I’ve seldom seen to this extreme. Back under its SW flank, the near storm developed a circular, slowly rotating, mottled texture to its main updraft region, and even sported a ragged, conical lowering for a short time. What could this storm have done with an extra hour or two before being swallowed by the expanding, ever-intensifying convective Pac-Man stampeding eastward toward us…and it?

The western storm charged onward, turning more deviantly rightward such that its main mesocyclone region — now an HP “stormzilla” with suspicious lowerings in its “notch” area (actual view and deeply enhanced zoom) would go just S of Yuma — while the value or near-forward flank region would absorb our nearby supercell virtually overhead. A short-lived lowering that preceded those photos raised a tight little plume of dust, but due to distance and poor contrast, we’re unsure if it was tornadic.

Though expected, this event still lit a sense of foreboding within, as if billions of icy little swords of Damocles dangled high above. This merging maelstrom of mayhem accelerated too, sure to turn into a destructive tempest of a nastiness and ugliness that we cared not to endure unsheltered. Time to get into town and under that covering!

Surprisingly, we scooted under the canopy of an abandoned drive-in restaurant after only one other car: the county sheriff. Only once the hail began did other vehicles seek room there — most in utter futility. Much as when it was the place to go in Yuma for icy treats of another kind…first-come, first-served! Within ten minutes, hail up to 2 inches in diameter started hammering away on the tin roof, becoming dense in coverage and ear-splitting in loudness. Vehicles that couldn’t fit got a glass-busting, steel-denting beatdown.

Although we had been hailed on while in a vehicle on several occasions, Elke and I hadn’t yet experienced a rip-roaring hailstorm together from under outdoor shelter. It was quality time as a married couple — at least, once I stopped yelling over the deafening din about the camera lens I couldn’t find. We had a blast.

I actually remembered to shoot some video of this with our new HD camcorder (video being something I’m not accustomed to doing after several years without), while also firing off a few hi-res DSLR stills with the lens that turned out to be in my left hand the whole time prior. One of those stills captured the a rare, split-second scene indeed: a hailstone exploding upon striking the pavement. It reminds me of some artist’s conception of an asteroid striking the moon, minus the fireball in the locus of impact.

After the beating was over, we secured a room at a little yellow motel. The lady who ran the motel mentioned that her daughter owned a restaurant and bar in town, Main Event, that was open and serving dinner late. Outstanding…we could avoid the usual storm observer’s conflict between getting dinner before early, small-town closing times and heading out for photography!

We headed a few miles SE of town to examine field hail and photograph the beautiful late-day, post-storm light (looking NE and looking WNW). Here are a few nice examples of that hail, about 45 minutes after it fell (culled from grassy, protected areas):

  1. Variably opaque core, clear outer layer with numerous radial bubbles
  2. Same stone silhouetted against the sky to illustrate its translucence
  3. Different stone, larger opaque core
  4. Two hailstones: Entirely opaque and rounded, the other asymmetric, broken and of mixed opacity
  5. Right before the sun sets, four hailstones on a gravel road [Would this compel Lucinda Williams to re-title one of her best-selling songs accordingly?]

While looking down at the hail, don’t forget to look overhead! Upon doing so, we saw sunset-lit fractocumuli shedding condensation vortices, including this ragged funnel and a separate, fishhook-shaped horseshoe vortex that wandered off to the E, slowly spinning down on its own for many minutes in the warming colors of the late-day rays (zoom). Here’s the western sky at the time.

All manner of fascinating processes were happening. Off to the SE rose a skinny, tilted tower, elevated atop the shallow stable layer from the earlier storms, seemed to be divided into two stepwise manifestations of the same convective plumes — one rooted just above the boundary layer, and a second slanted along some higher surface, with a backshear on the W side of the upper layer. Meanwhile, off to our E, dark wisps of scud passed placidly in front of a gorgeously glowing tower in the back side of the MCS. All of this while immersed in the luxuriantly earthy scent of rain-soaked farmland, while western meadowlarks sang from all sides…

We were getting hungry, though; so we cruised back into town for what turned out to be a very good meal at Main Event. I recommend the place for a late dinner if you end up anywhere near Yuma after a chase.

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