Ice Machine in Yuma, Colorado
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:
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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):
- Variably opaque core, clear outer layer with numerous radial bubbles
- Same stone silhouetted against the sky to illustrate its translucence
- Different stone, larger opaque core
- Two hailstones: Entirely opaque and rounded, the other asymmetric, broken and of mixed opacity
- 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.
Panhandle Unchase
Channing/Groom TX, 25 May 10
SHORT: Observed supercell get munched by outflow-dominant multicell complex NW of Amarillo. Pretty sunset.
LONG:
This wasn’t specifically intended to be a chase day; but if we happened to see a decent storm along the way, that was acceptable! We had a truck bed full of cargo from Elke’s late mom that we were bringing home from DEN-OUN. Even though most of it was well-covered by plastic, getting in a bunch of rain and especially hail was not a palatable option. Therefore, even though the most dense concentration of convection promised to be along the Kansas segment of the dryline, where tornadic storms did occur, we opted to use the southern route through the Panhandles in hopes of more discrete activity.
We could see the first towers erupting along the dryline, early in the afternoon and to the distant E-ESE, while still on I-25 in southern Colorado. After turning ESE on US-87, a series of big towers grew into storms to our ENE and NE, including some of the Kansas activity that provided the joy of rich and abundant data to V.O.R.T.EX.-2 scientists. Near Des Moines (the New Mexico town, that is), we saw a classical, atom-bomb style of thunderhead eruption in the western Texas Panhandle, off to our SE (here photographed beyond one of the area’s numerous, inactive cinder cones). Given the favorable shear and discrete nature of this storm, its destiny as a supercell was assured, and our destiny was to intercept it — preferably avoiding most of the precip.
It took us a long time to get around to the E side of the slow-moving storm, even via the fairly direct CAO-DHT-Hartley route on US-87. As we approached DHT, radar imagery indicated that a left-split off of some storms N of Clovis was growing into a large, northward-moving multicell cluster — headed directly for our intensifying supercell! Just our stinkin’ luck! Tracking our course and that of the raging multicell cluster from hell, it was obvious the solitary supercell with so much potential would be snuffed out like a match in a fire hose, not long after we got in viewing position.
Our viewing position turned out to be virtually the same spot N of Channing from which Rich T and I first observed the tornadic Dumas-Stinnett supercell from 18 May. Unfortunately, this textured and colorful little storm was about to be absolutely destroyed by the onrushing wall of outflow and convection from its S. We had about 15 minutes of viewing as that happened, then headed to AMA.
There was too little daylight left to attempt to intercept Jeff Passner’s tornadic storm near Dimmit, so we stopped in AMA for dinner, drove E, photographed the Leaning Water Tower of Groom in some nicely reddening sunset light, then drove on home in the dark of night. So, in effect, we were able to observe the shortest-lived and most decidedly nontornadic supercell in between all the longer-lived, tornadic ones.
Northern Burlington at Sunset
14 Jun 9
Eastern CO
SHORT: Saw high-based, outflow dominant storms from the distance in central Colorado, evaded eastward, waited for other storms to form but not long enough. Treated to wonderfully colored sunset at Burlington CO.
LONG:
Elke and I had a good breakfast at the Memories restaurant in Ft. Morgan (highly recommended), before dropping S toward Last Chance to await storm formation possibilities either on the CYS or Palmer Ridges. While sitting on a hilltop between Last Chance and LIC, we saw a very distant Cb explosion to the NNW, which I-Phone radar revealed to be a rapidly evolving supercell near Chugwater. That was out of reach, realistically, and so was the potential afternoon target along the boundary in SW KS.
We waited longer for Front Range and/or Palmer Ridge storms, dropping S to LIC for shade and better data access. While there, a tornado-warned line of storms quickly fired over the DEN metro area (producing that funnel near downtown and Coors Field). I was disinclined to run immediately after that activity, given its linear and likely high-based character.
We kept waiting at LIC for closer development, which did happen to our W and SW. Alas, it was linear too! Still no photos for the day yet…the activity was distant, but I already could see a shelf cloud emerging through some mild haze WNW-SE of us. I envisioned an unfriendly wall of outflow surging E across central and eastern CO, so we threw in the towel on active chasing for the day, perhaps a little too soon.
We arrived at ITR, got a nice and cheap motel room, and ate dinner at the slow and overpriced steakhouse there (not recommended!). We clung to hope for at least an interesting, shelfy sunset. Meanwhile a couple of brief supercells appeared near the tail end of the line before being munched by the meso-beta scale cold pool (these were the storms observed by BillR, MattC and MikeU).
Even the linear MCS appeared to weaken as it headed toward us, but we went to the N side of town to watch it roll past anyway. The sky was remarkably hazy for eastern CO, but once the gust front hit, the view cleared a good deal. A line-echo wave pattern (LEWP), with a brief and embedded supercell to our N, sent a rear-flank augmentation overhead just in time for the setting sun to shine through its precip curtains, opening up a brief bu dazzling splash of warm coloration in the rain curtains.
As the reds began to fade, the blues deepened in the nooks and crannies of the overhead shelf cloud’s turbulent underbelly, compelling a wide angle shot of the beautiful and unusual scene. It was a fantastic way to close out what had been a rather uninspiring storm day.