Tushka Culmination
Southeastern Oklahoma, 14 April 11
SHORT: 3 supercells intercepted in SE OK, likely end of Tushka tornado witnessed after navigating damage.
LONG:
Ryan Jewell, Jaret Rogers and I left Norman after working the day shift, headed SE toward Ada to get ahead of the supercell that already had crossed I-35 near Davis. Vigorous convection had gone up just E of Norman too. We eschewed that option completely while E of Lexington, given that it was heading into an environment of weaker shear and buoyancy than farther S, and had messy radar structures and mergers happening by then.
Alas, so did the old Arbuckles storm, by the time we saw its inflow region, looking NW from near Stonewall. We had beaten the hail core through Ada by just a few minutes, and took the time to marvel at the turquoise color of the wrapping precip and the long tail cloud. Motion into the mesocyclone region was really fast, inflow screaming from the SE; but mergers with other cells to its S had rendered the supercell, still with an intense mesocyclone, a garishly greenish HP stormzilla.
Two more supercells beckoned to our SW, the first headed for the area between Tupelo and Clarita, and easy to intercept. The storm had a great reflectivity hook, and was TOR-warned; but the low-level velocity structure didn’t look particularly vigorous on radar. Visually, as seen from Clarita (looking WNW), the convective structure was very robust, the base far less precip-infested than the Ada/Stonewall storm. Still, it had a long, scuddy rear-flank gust front, with similar scud drifting about under the putative mesocyclone region. A broad, ragged, very low-hanging, but only weakly rotating wall cloud formed, then fell apart. Not too impressed, we didn’t longer longer, and made haste down OK-48 through Coleman, to OK-22 and westward after the southernmost (anchor) storm near Tishomingo.
We arrived within sight of the storm’s base just a tad late to see the Tishomingo tornado, having this NW-looking view of two wall-cloud regions as the storm moved close to Milburn. The nearer (dark) one fell mercy to the rear-flank downdraft wrapping around the more distant, northern, older, and occluded meso near Milburn (brightened by clear-slot light in this later shot). Here we met and chatted for a spell with Ashton, who later ended up in the damage track of the Tushka tornado very near us as well.
The near (southern) meso thus undercut, we headed N to get a closer look at the circulation near Milburn, but it too was weakening. A wrong turn in Milburn led us to some knobby and often partly broken hail up to 2-1/4 inches in diameter, which we photographed before heading the correct way out of town. We zigzagged from Milburn to Coleman, getting close to the storm’s back edge of the re-intensifying supercell’s hook region. We considered an unmarked road to the east, through Boggy Depot, but rejected it as unsafe, given its unsavory look on the road map, and its precarious position slightly N of astern with respect to the new mesocyclone area. Take that road, we knew, and huge hail wrapping around the backside of a hook echo would be a sure fate.
Instead we busted S back to OK-22 and E to US-75, then N past Caney, arriving to see a mesocyclone with dark, amorphous murk beneath moving past the road in the distance.
Not yet knowing that a tornado was somewhere within that murk, we proceeded NNE up US-75 into Tushka, unaware at first of the intensity of the damage until we had gotten irreversibly into it, embedded in a stream of slow-moving traffic. Broken and uprooted trees appeared on both sides of the big roadway, becoming more numerous in the first mile or two, along with assorted sheet metal, pieces of wood, broken road signs and other variegated flotsam. The blended scent of shredded vegetation, split green wood and rain deeply saturated the air, a unique aggregate aroma I’ve experienced only amid fresh tornado damage.
Right after we drove several feet safely beneath some low-hanging power lines, an adjoining tractor-trailer rig hit them…and kept going full speed! It busted at least three power lines, yanked down a power pole that still had been standing, and may have dragged another already downed pole a short distance. I suspect one of my most abiding memories of this chase will be the furious, staccato “THWAP THWAP THWAP” noises as the cables snapped just behind and next to us. We were aghast that the driver would just plow right through low-hanging power cables, snap them mercilessly, and keep on truckin! I guess he had places to be.
Even within a few minutes after the tornado, plenty of police and other first-responders already were arriving or there. We saw several vehicles flipped asunder, as we navigated around whole trees and large debris on the road; and every overturned vehicle I could see either had no one inside, or at least one person standing next to it. Under those circumstances, and mired the plodding traffic, the best move was to get through the mess safely and expeditiously as possible, and get out of the way of those who needed to be there. It reminded me eerily of coming into the damage swath along I-44 right behind the (also rain-wrapped) Catoosa F4 of 24 April 93. As we entered Atoka, the damage lightened; though we could see more off to the east.
With several miles of damage along the highway, the tornado obviously was fairly wide, even if not exceptionally violent, and took a very oblique path with respect to the road. Even in the deepening twilight, now quite dim under all that storm-cloud cover, we still could see rapid scud motions from left to right above the road (NNE of us), wrapping back around an unseen mesocirculation center to our NE. From Ryan’s I-Phone radar, we figured the mesocyclone (and temporarily, the storm as a whole) had taken a left hook toward the NE, with a new occlusion forming farther downshear. As it turns out, Rich confirmed this for us while we were still in the damage, calling him to report it just in case none of the other hundreds of people had. He also let us know that the mesocyclone was narrowing and perhaps even crossing back over the road as it veered leftward.
Lo and behold, right then we saw a power flash to our NNE, slightly leftward of the road, near Stringtown. Within a minute or two, a ghostly, dim but still very apparent cloud cylinder emerged from the wrapping precip, right in the direction of that power flash. The cloud column, whose bottom was obscured by a terrain ridge, contorted and gyrated wildly, with a ragged coil or helix of scud pulling around the near side shortly before it fell apart. The previous volume scan showed the narrowing couplet in that spot, and the next had it dissipated.
I am now convinced that was the deeply-occluded demise of the Tushka tornado near Stringtown, kicking back out of the rear of the precip-filled area (as I’ve seen a few times before). This is based on Rich’s real-time descriptions of the meso occlusion process on radar, my own post-event radar review, the path/timing of the old occlusion relative to our position N of Atoka, what has been documented of the path so far, and of course that wildly morphing cloud cylinder near where we just had seen a power flash. All things considered, not very satisfying. It’s ironic that the best view of the tornado (Gabe’s, while in some gigantic hail) was from the WNW–the angle we chose not to approach when we were just behind the storm in Coleman.
After the meso died, it was dark; and we found ourselves in a quandary. Dense cores kept crossing US-69 to the NNE, the NW route to Ada (US-75/OK-3) was blocked by a supercell, another supercell was back near Wapanucka headed for Atoka, and miles of tornado damage lined US-75/69 to our S. Solution? Eat. Also, sit down and plan some escape strategy.
At the Subway in north Atoka (an undamaged area), we heard of a triage setup elsewhere in town–the first sign that some casualties had happened. This was bad news indeed. [We didn't hear of the two fatalities (elderly sisters) until after returning to Norman.] The next TOR polygon for the supercell to our W included Atoka; so the already frazzled employees started locking up to take shelter.
We finished eating out in the vehicle, as the supercell to our W weakened and passed just to the NW. The door out of the area now opened, we then headed home, listening to a combination of Metallica, Slayer, Iron Maiden and Pantera on Ryan’s phone to just wind down a little.
Meteorologically, our forecasting and pre-storm conceptualization was reasonably good. The only part that didn’t work out as well as I like was the large number of left splits and close-proximity cells that made storm modes messier than the orthogonal deep -shear vectors would indicate. Smaller early hodographs with some negative SRH probably contributed to that, along with a nearly simultaneous dispersion of CINH all up and down the area just E of the dryline, from the Red River to the KS border.
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.
Chugwater Tornadic Supercell
Chugwater WY, 20 Jun 10
SHORT: Observed tornado from second of two supercells E of Chugwater.
LONG: Since Scotts Bluff National Monument was just a few blocks from our motel doorstep, we had time for some late morning through midday hiking, as well as photographing wildflowers and other interesting scenery near the top, before grabbing a quick lunch and heading west to our target area of southeast WY. See, for us, the so-called “storm chase” vacation isn’t just about storms, but about appreciation of as much of the Great plains’ offerings of beauty and wonder, large and small, as possible — storms being the major component, but not the entire experience. And so it was that we strolled atop the bluff o’ tuff, pondering the view up this way from the Oregon Trail’s wagon trains rolling up the North Platte valley below, while also occasionally looking at surface maps and satellite images on our I-Phones, and considering the effect the stable air represented by this stratified overcast would have on the day’s convective potential.
Thin breaks and occasional peeks at the sun indicated some destabilization was occurring, in an area of nicely backed surface winds from there westward, and automated mesoanalyses of CAPE and CINH fields bore that hunch out. As we descended from the hill, as if on cue, the first towers began to erupt over the Laramie Range, where the clouds had been eroded over the highest terrain in the area, allowing maximum heating. We couldn’t see them through the stratus, of course, and I had doubts about how far E convection could make it off the mountains before getting into grunge and weakening There was no doubt we needed to follow Horace Greeley’s old advice and “go west”. As we did so, two storms started to rotate:
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1. A cell in the Wheatland/Dwyer area, headed NE toward Jay Em but also toward some decidedly stable air, and
2. A storm moving somewhat more slowly and seemingly anchored along the foothills near Chugwater.
We went through Torrington along the way, then SW, catching a brief view of the distant and uninspiring base of the northern storm, before moving SW toward an area of obvious darkness above and beyond the intervening stratus deck. By the time we got to a good vantage W of Yoder and S of veteran WY, the southern storm, which had been a supercell, already was losing definition in its base and soon would turn into a strung-out, most likely elevated plume of convection.
Fortunately, the strong heating continued off the W edge of the stratus deck and the E edge of the mountains, firing additional convection still farther SW. With the boundary layer continuing to get more unstable in that direction, we backed through Yoder and S again past Hawk Springs. Then we then headed up the beautiful bluffs E of Chugwater along one of my favorite drives in the region (WY-313), only to greet an already well-developed and obviously surface-based storm by the time we arose on the high plateau E of I-25. The storm was calving off left splits, one of which can be seen beyond an abandoned farm structure in this shot looking WNW. Turning our attention to the WSW, the large, robust right mover quickly cut a clear slot and formed a broad, rotating, bowl-shaped lowering
behind it (and above the letter “s” ending my name in this wide-angle shot). This was only a few minutes after we had arrived at our location, and then, at 1624 MDT (2224 Z)…
T-TIME!
You see, in most years, a tornado is such a rare and amazing event to witness for any storm observer. This year, I had experienced lousy luck with tornado photography in what has been a banner season for some others. In most cases (e.g., Bowdle SD, Faith SD, Campo CO), I wasn’t available to chase on the fantastic day in question. On one (10 May, OK), I (along with some other very talented chasers) got on the one storm that refused to produce anything more than a brief spinup while observable. On another (16 Jun, SD), the storm blocked the only safe road access to it with flooding and hooks filled with both precip and precip-wrapped tornadoes, while also going nuts on the other side.
After all that tornadic frustration, then, it surely felt good to see one that was not low-contrast, rain-wrapped and/or too brief to photograph, even if it was a small and otherwise not very newsworthy hose. The tornado slowly roamed wide-open land and, to our knowledge, hit no structures of consequence — just the way we like it. As seen from about 3-4 miles to its E, the tornado manifest initially as a tapering cone (zoom), with two episodes of visible ground contact. The first is shown in this zoom (see wide angle structure view), followed by a few minutes where neither condensation nor dust was evident under the base of the funnel (wide angle structure view), followed by a few minutes where full condensation planted again.
That vacillation was described by some observers as separating two tornadoes that occurred from the same vortex (by definition, a tornado must have ground contact), while others deemed it as one tornado with a weak interlude. What is a tornado? The ground was soaked out there, minimizing dust, although it did lose full-condensation again before lofting some combination of spray and dust (super wide, with storm structure). The tornado started to wrap deeply back into its occluding mesocyclone, then roped out.
Tornado-wise, that was all the storm could do. We felt fortunate to get there just in time! We also had to bail east, off the high plateau, because hailstones of 2 inches and larger in diameter started falling around us with discomforting splats and thuds right as I was shooting the last rope-out photo. We got out from under the vault with no hail impacts, then headed S and E in a very difficult effort to find a good W-NW view of the weakening supercell that wasn’t overly obstructed by terrain. Some others we know weren’t so lucky with hail. At that vantage, we encountered the Tempest bunch with Chuck, Chad Cowan, and Bill Reid, here shown calling for lodging from behind two giant hail craters patched with duct tape. Not far to our W, as the tornado began to narrow, that part of the vault immediately downshear from the low-level mesocyclone unceremoniously heaved forth gorilla hailstones up to 4 inches in diameter. It’s a good thing nobody was hurt by that hail (a vastly under-appreciated injury hazard in storm observing)!
The supercell moved over progressively more stable low-level air while attempting to backbuild, and eventually just died. That left us with no storm and some daylight, which we used for traveling to our motel in Sidney. On the way down toward I-90, we stopped to photograph an abandoned farm with soft stratocu and baby-blue sky in the background. We then hopped on the Interstate for a very unusual (for late June!) plunge through a late-afternoon regime of cool fog and mist, in the stratified air mass E of where the supercell had been.