Buried Tornadoes by the Border
Chugwater WY to Kimball NE
22 Jun 13
SHORT: Intercepted 2 supercells in SE WY, first photogenic, second became dark and nasty HP with about two tornadoes buried inside and barely/intermittently visible. Lightning and photogenic outflow formations with tail end of resulting MCS in NEb Panhandle.
LONG:
Having made a full-circle back to Chadron from five days before, we did a little late-morning photography of abandoned antique vehicles that we had seen previously, then bid farewell to our favorite north-central High Plains town to head SW. We targeted as promising of an upslope-flow supercell scenario in southeastern WY as you’ll ever see, realistically. The previous day’s boundary was shunted southward toward the Cheyenne ridge, flow behind it veering throughout the day to both advect unusually rich low-level moisture upslope (beneath favorably strong midlevel winds) and yield a big hodograph. That moist air rising up the Laramies would do the heavy lifting, with help from hours of sunshine. Since we actually weren’t far away and were leaving before noon, I was as confident in seeing a tornadic storm on this day as any the entire June trip. Slap those hands together, fill the tank, hit the road, and get ready to rumble under some spinning sky.
Supercells rolling off the Laramie Mountains under similar flow patterns and even less moisture have produced delicious tornadoes on several occasions in the last 15 years. For some reason, we (and I, before marrying Elke) had been late to the party for most of them, either missing the tubes or barely catching their end stages. The 2010 Chugwater storm was, of course, a wonderful exception. Even early initiation wouldn’t be a problem, given the long N-S roads of eastern WY and the good visibility away from the E slopes of the escarpment between Hawk Springs and Chugwater.
Over the hills and into Wyoming we went, fueling in Lusk under the midday sun as anvils began streaming off the northern limb of the Laramies. This was early initiation indeed…for which (for once) we were ready! The most vigorous cell, near Dwyer, appeared to be turning right and organizing into a supercell fairly quickly. Fortunately, it was aiming right down US-26 toward the Lingle area, where getting ahead of it would be easy. No wondering what was over the horizon, no driving 150 miles after an early-forming Wyoming storm already in progress! When we got just S of Lingle, there it was, in youthful supercellular splendor, to our W.
The supercell traveled ESE as another developed to its SW, with rain from the newer storm cascading into the established supercell‘s upshear region. After briefly encountering fellow storm observers Vince Miller and Matt Crowther, we moved a few miles S, stopping briefly to watch a beautiful phase of the otherwise shrinking and rising cloud-base configuration, characterized by a clear slot with tightening rotation. Nothing came of that; the occlusion downdraft cut too tightly into the rotation area and dry entrainment eroded what was left. The older cell then slowly weakened at the expense of the rapidly strengthening upshear storm, and we headed S toward Veteran to get in front of the latter.
What we found there was an entirely new animal–one that would turn into a menacing, growling, teeth-baring, attacking beast in short order. Looking SW at the reasonably large updraft area, ragged, slowly rotating shelf/wall cloud hybrid and dense core, it was easy to predict that this beautiful mess of a storm would become an HP in short order. Since the entire storm was moving ESE, this was an unsustainable viewing position; the forward-flank core and its hail would impose its will on us if we stayed put much longer.
A quick zigzag E and S out of the Veteran/Yoder area took us onto US-85 NE of Hawk Springs and NNE of LaGrange. We had to bolt S ahead of the strengthening mesocyclone to our SW in order to take the east option toward WY-151/NEb-88. First, however, we had a few minutes to stop, observe and admire a very rapidly intensifying circulation–a photogenic and menacing wall cloud that quickly evolved into wide, rapidly rotating, nearly ground-scraping bowl, a mesocyclone that clearly meant serious business. A small funnel briefly whizzed around the left (SE) side of the bowl, but with no clearly discernible debris beneath. The entire spinning mass of gas still was moving ESE and we were NE of it. No time to tarry…we had to go!
We skirted the E edge of the orbiting precip curtains from N-S as the mesocyclone quickly wrapped in rain and the storm took on a mean, nasty HP form. I’m used to tangling with those in north TX, but not on the more road-sparse plains of the WY-NEb border. Fortunately the east-151/88 option was conveniently located to offer a chance to get safely ahead of the whirling dervish for awhile, albeit in the eventual path. A brief glance at radar indicated a rapidly tightening and potentially tornadic mesocyclone to our NW as we approached the border. I stopped there to observe and thought I might have seen the tornado (see photos in table below), one about which I was more certain that night, after viewing the photos via camera display and talking with the NWS office. Given its S of E movement, we couldn’t stay too long.
After charging E across the border, after a mesocyclonic cycle, and while I still was driving to gain some distance, Elke took a look at the radar display and saw this rather alarming SRM signature a few miles to our NW. There was obviously another tornado somewhere in that dark precip mass–and likely a significant, potentially violent vortex to boot! It also was moving ESE, meaning we would have to stair-step along the W-E highway in multiple stops to stay safely ahead of it, and of the wrapping precip.
Needless to say, I slowed down really quickly and turned into a northward-directed side road to stare hard into the rotating cylinder of precip. At times, during the second of two different stops along NEb-88, I could make out the tornado ‘s condensation funnel–briefly, barely but confidently. We stopped again after turning S on NE-71 past Harrisburg.
What follows is a chronological table of links to a selection of photos taken at the stops, looking NW at first, then WNW. The photos show the region as it looked with eyeballs (“PHOTO”), heavily enhanced (“ENHCD”) and in a few cases, enhanced and annotated (“ANNOT”) to bring out the tornado where possible, and to illustrate the motion. Curved arrows on some ANNOT images show the area of very intense rotation. All of these were processed within a few weeks after returning and provided to the CYS WFO for their evaluation. [I have them prelim track and time estimates the same night via phone call using adjusted camera times (camera was 4 minutes fast).]
[Please scroll down to see the tornado-photo table and the rest of the post. I don’t know how to fix this gap.]
|
Sequence Number & Viewing Location
|
Normal and Edited Photos
| |||
|---|---|---|---|---|
| 1. 2 W WY/NE Border, WY-151 | PHOTO | ENHCD | ANNOT | |
| 2. 2 W WY/NE Border, WY-151 | PHOTO | ENHCD | ANNOT | |
| 3. 2 W WY/NE Border, WY-151 | PHOTO | ENHCD | ANNOT | |
| 4. 3 E Stegall S Rd on NE-88 | PHOTO | NO ENHCD | NO ANNOT | |
| 5. 3 E Stegall S Rd on NE-88 | PHOTO | ENHCD | ANNOT | |
| 6. 3 E Stegall S Rd on NE-88 | PHOTO | ENHCD | ANNOT | |
| 7. 3 E Stegall S Rd on NE-88 | PHOTO | ENHCD | ANNOT | |
| 8. 3 E Stegall S Rd on NE-88 | PHOTO | ENHCD | ANNOT | 9. 3 E Stegall S Rd on NE-88 | PHOTO | ENHCD | ANNOT | 10. 4 NE Harrisburg on NE-71 | PHOTO | ENHCD | ANNOT |
Because the tornado on the Wyoming side of the border (images 1-3) appeared to shrink and get deeply occluded into the precip, and because NWS CYS surveyed a distinct tornado track on the Nebraska side, I now very strongly believe (>95% certainty) that the Wyoming and Nebraska tornadoes were separate. On the Nebraska side–yes, there also was another dark, columnar area to the left (SW or WSW) of the tornado cyclone in a few images (mainly 4-5), but I could not tell what it was. The rotation of precip around the tornado in each photo was furious and obvious. Even when I couldn’t see the tornado at all (which was most of the time), there was no doubt of its presence.
Due to lack of visual continuity, I also can not state definitively if the Nebraska tornado was continuous between stops, or two separate events. NWS surveys indicated one path in Nebraska, so I’ll count this as a single, second tornado for now, given no firm evidence to the contrary. The tornado only hit a few things, earning an EF1 rating due to sparse/weak damage indicators. However, its WSR-88D radar signature is consistent with many strong to violent (EF3-4) events, based on a study underway by Bryan Smith and others at SPC. We’ll never know its true strength.
The tornado moved almost directly toward my position in image 9, but dissipated before it got to NE-71. By that time, we had bailed S, out of the way, and found a hilltop S of the 71/88 intersection. There, we tried to view the deeply occluded, embedded meso as it got thrust back out of the rear side of the precip area (enhanced. There may have been a weak tornadic (or nearly tornadic) circulation still going at that point (enhanced), as visible cloud-base rotation still was reasonably strong. I can’t say with complete certainty. By this time, a big gust front and shelf cloud had surged well ahead of the mesocyclone. The supercell was evolving into a linear structure with more storms erupting to the SW–we had an MCS and QLCS on our hands.
Plenty of daylight remained, so…time to go tail-chasing! We proceeded S to and past Kimball in search of a vantage, and found one 3 SSW of town on County road 28, right along the N side of Kimball airport (IBM). This was a treat! Even though the complex was decidedly outflow-dominant at this stage, its arcus underside and photogenic lightning were just plain fun to observe. The core passing to our N fired a good volume of electrical artillery from the same general area (including one whose most visible segment was “questionable”). One bright outlier, an outflow-influenced channel and a few other strikes followed as the core moved E. Meanwhile, the arcus’ underbelly passed overhead and to the S with fantastic sharpness to its turbulent texturing. What a crazy, interesting sky!
Ravenously hungry by now, and chilling uncomfortably from all the outflow, we snapped the shutters at a few more strikes from the last passing core, then headed into town for dinner. Amidst that huge and expansive puddle of outflow, we didn’t imagine that an updraft would blossom to the E that was surface-based, and produce a brief tornado (seen by a few observers still afield) before being undercut. That’s how it goes sometimes. While somewhat disappointed, we could live with it. We had seen some serious tornadic action already, and the hot pizza tasted mighty good going down. Here was one final look at the back side of the complex from the pizza-parlor’s parking lot, as the storms retreated into the suppertime sky.
After checking into the motel in Kimball, I got the tornado time/track info to the CYS WFO to the best extent possible, then reflected back upon another long but very rewarding chase day–one fruitful both photographically and in terms of both tornadic and nontornadic storm experiences. Forecast guidance also indicated that we had one more day of decent storm potential in CO before we had to head home. Our time in Montana was growing ever farther away in the rear-view.
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Our PING trail for this day. [PING date is ending date in UTC.]
Washing Two States
Central SD to Chadron NE
21 Jun 13
SHORT: Bypassed morning/mid-day SD MCS on its NW-W-SW side. Second MCS developed all around us in afternoon near CDR offering eccentric skies & flood.
LONG:
Recall, from the previous day’s summary, that I mentioned the unplanned adventures of storm-observing jaunts. Today was like that. We awoke in a Mobridge motel to a few itchy bites in places mosquitoes wouldn’t be able to access. We immediately suspected bedbugs, despite the lack thereof in the previous night’s customary inspections of beds and bedding. Another thorough inspection turned up none–so the mystery remains as to what got us. Whatever, it was time to get the hell out and not look back.
Laundry needed to be done anyway, given that we were in our last clean clothes. That process took longer than expected due to slow-working, money-sucking dryers; so we were stuck in MBG until that was done. This was important, as a complex of thunderstorms erupted early in the morning over the southern Black Hills (producing 4.25-inch hail!), expanding and rolling out across the Badlands area, sweeping ENE across much of central and southern SD, and treating storm observers near I-90 to a nice morning shelf-cloud display that we had to miss. All we saw, while laundry was going and while eating lunch, was the dark, amorphous gray mass of the MCS slowly shifting eastward across the southern sky.
Explosions of mid-late morning convection all over the target area seldom portend sweet supercellular tidings in the afternoon. The previous night’s thinking of a Badlands-area target would have to be revised southward, thanks to outflow from this big, unwelcome convective bomb. It was looking more and more probable that we needed to drive at least an hour or two farther SW then previously anticipated, into Nebraska. First, clean clothing and a hot meal took priority.
Lunch itself was very good–German food at a restaurant in town, just a couple of blocks from the washateria. The proprietor–a lady about my age but speaking with an odd Germanic accent, herded her own kids to and fro while serving meals and manning the register. Elke was perplexed by the accent too–not anything she was accustomed to hearing from a German or Austrian immigrant, yet decidedly of that origin. A later conversation with her revealed that she was a fourth-generation American and fully fluent in English, as had been all her ancestors in that area, but that conversational German had been passed down to her through each of four generations following 1800s immigration. That explained it–the pronunciations and cadences had been Americanized slowly over 100 years, but the words and sentences still were correct German. I wondered how she would sound to a Munich native if speaking that flavor of South Dakota German in Bavaria!
As we finished lunch, but before laundry was ready, supercells began to form ahead of the MCS, to our E and ESE and within an hour’s drive or so. This was mental torture. Yes, a quick eyeball modification of observed and forecast soundings indicated they were surface-based, as did the quick development of an intense, tornado-warned mesocyclone. These probably could have been intercepted, if not for our situation, and a tornado was reported with one of them before the cells all got absorbed into the northern fringes of what now was a raging bow echo. It wasn’t even after 1 p.m. yet! How could I get mad at missing weird midday tornado action ahead of an MCS? I didn’t.
By the time we got laundry done and packed, the supercell action was winding down, and the bowing complex had finished mowing across the PIR area and U-83 to our S. We headed down that road, through the back-side rain and lightning, admiring the oddly lit midday sky with darkness in the NE-E-SE and blue in the NW. At PIR we broke into milky skies of thin, training high clouds with slowly warming outflow and soft, stratified fuzz patches for low clouds.
Data checks showed the outflow boundary arching from about 80 miles S of us across Cherry County and into the Black Hills–still moving S but not very fast, and starting to cook in the heat of insolation on both sides. Vorticity source, vorticity source…hello! Despite the weaker-than-desired mid-up-er level winds farther S, perhaps a storm forming on or interacting with that boundary could spin up a needle-in-haystack surprise, if we caught it at the right place and time. Remember: I forecasted this.
Making the strategy work was another story altogether. It took us a few hours to zigzag our way across the reservations, through Martin SD, to Gordon NEb. By then, deep convective towers were apparent on both sides of the outflow boundary, which still was moving S about 10 mph but decelerating. The cap was weak and getting weaker, with very unusual 68-72-degree dew points along and S of the boundary. At that altitude, juice like that couldn’t be held down for long.
Moisture won–fast. In the relatively short time it took us to fuel up in Gordon, which was right on the boundary with nearly calm winds, the sky grew dark quickly, in several directions. Storms were blowing up to the NE, SE, S, and W–all at once, and acting like they wanted to merge. The most discrete, least messy area appeared to be to our W, toward CDR, which also was on the boundary. We headed that way, observing this storm rise with low, sopping-wet cloud features more suitable for Florida than northwestern Nebraska.
Somewhere back in the darkness to our E, in the messy storm mergers, a strong mesocyclone spun up on radar velocity displays, followed soon thereafter by a tornado warning and report…near Gordon, where we just had been! Determined not to get frustrated and whipsaw back after something that obviously would be transient (and turned out to be), we stayed with the convection near CDR. How could I get mad at missing weird cluster-embedded tornado action in what was becoming an MCS? I didn’t.
The sultry character of the air mass, in a place like this, was a dichotomy of two worlds–a vorticity-rich, humidity-laded gob of air that felt and smelled like a tropical depression, storms seemingly blossoming everywhere, but in a setting that hardly ever sees such conditions. I soaked in the familiar sensation from much lower latitudes–my mind singing, “5:00 somewhere”–until the outflow hit. That was that for that.
Storms were backbuilding to our WSW, just S of CDR, with outflow now past the town. Driving right by it anyway, and for good measure, we briefly stopped to secure a room for the night at our favorite motel there, the Westerner. The staff recognized me from my prior two visits this year, and was glad to get a weather report from their “expert storm-chaser guest”. Before we headed back out to get S of the backbuilding line, I told them to be ready for flooding rains, maybe some hail, but tornadoes looked unlikely in town.
By the time we got back out of town and onto the high ridge just to its S, tornadoes looked unlikely everywhere in the area. We could get back into the warm sector, but the storms were outflow-dominant, kicking big, ragged scud piles well ahead of any updrafts. There was a manifestation of the lack of more intense ambient shear. But hey…scud and outflow can be scenic, wondrous, captivating…and for several moments, these certainly were!
Uniquely arranged and oddly lit assemblies of landscape, low cloud banks and the background storm pall gave us a fine and fun time on the southern fringes of the Pine Ridge. Muted translucence from the late-day northwestern angle of the hidden sun, with deep cloud mass to the north and northeast, permitted an odd southern light to wash across the front faces of the low clouds, beneath and behind variegated slate tones aloft. That southern light reflected from the scud onto a part of the deck above, subtly illuminating it from beneath. Toss a green field foreground into the mix, and this was the fascinating result.
Gusting out as it sat nearly stationary to our N, the complex emptied its load on parts of CDR and areas uphill. Resulting torrents of flash-flood waters rolled off the southern hills and through the streets as motorists and motorcyclists casually ignored the latter-day mantra, “Turn around, don’t drown.”
The steak-and-sides dinner we had at Feiks (a recommended eatery) was bland, overcooked, overrated (by online reviewers) and overpriced, though service was attentive. We’ve had worse meals, but we likely won’t be going back there. By the time we were done, we were ready to return to the room, PING the last bits of rain, wind down for the night, recollect a long but worthwhile adventure, and imagine what the next day’s Wyoming upslope-flow action could bring with unusually rich low-level moisture involved.
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Our SD PING trail for this day. Our NEb PING trail for this day. [PING date is ending date in UTC.]
Thunder Basin Thunder
Ogallala, Thunder Basin and Buffalo Gap National Grasslands (NE/WY/SD)
17 Jun 13
SHORT: Early elevated storm CDR, back-of-MCS mammatus show eastern WY.
LONG:
BANG! That was how our day started, as a very close lightning strike awoke us from slumber in our motel room. Elevated storms had been rumbling overhead for some time during the early daylight period, their rain pattering a stay-asleep-please lullaby outside; but that vicious blast on the trailing side of it all was a literal eye-opener. [During a later visit to CDR, we found out from the motel proprietors that the strike split a tree in half about a block from there.] I PINGed the rain, of course.
Anticipating that any storm potential on this day would be roughly on the way between CDR and our intended destination of Buffalo WY, Elke and I started the day with a short driving tour of CDR that we have been wanting to do for years, then saw another long-desired destination there: the Mari Sandoz High Plains Heritage Center at Chadron State College. Though small, the museum was well worthwhile–a great tribute to the life of the High Plains pioneer writer and documentation of the hardscrabble life she and her parents led in settling the Sandhills.
Leaving the museum, we saw the sun peek out but also heard distant rumblings to the W. A small, elevated thunderstorm was riding the top of the outflow pool from the morning convection. While Elke gathered some supplies at Wal-Mart, I found a nearby hilltop from which to enjoy the view. The verdant prairies of a Nebraska Panhandle springtime can make even an ordinary, elevated storm seem majestic and beautiful! We ate lunch from that hillside Country Kitchen with the grand SW view, then hit the road NW into the SW corner of SD.
Forcing for deep convection appeared rather muddled on this day, with marginal shear for supercells. Still, with…
- A weak cap in modified UNR sounding,
- An outflow boundary from the morning storms arching back across eastern WY to our SW and W,
- Orographic features in the form of Black Hills and Bighorn Mountains looming to the NW and NNW, and
- Prospects for strong and sustained insolation…
…we had good cause to expect seeing a storm at some point this day. We planned to dabble in whatever convective pleasures the atmosphere offered, then settle into Buffalo for the night with a trip through the Bighorns planned day-2 and some Montana chasing on the docket day-3. Only a few days out of Norman, our Oklahoma home nonetheless seemed so far away and long ago as we trekked across the grand vistas of the northern High Plains and around the SW rim of the Black Hills.
Visiting the adjoining Ogallala (NEb) and Buffalo Gap (SD) National Grasslands for a spell, we did some short hikes over the wide-open Plains, dodging flowering cacti while watching persistent but non-deepening high-based convective towers to our SW, over WY and along the boundary. In the distance, convection built over the Black Hills and small, fuzzy anvils started to spread off the eastern slopes of the Bighorns.
We zigzagged the mixture of paved and unpaved roads characteristic of southwestern Fall River County, skirting just close enough to the Black Hills convection to see that it was rather high-based, poorly organized, incipiently outflow-dominant and unlikely to survive in any chase-worthy form after peeling out of the hills. Meanwhile, the persistent towers to our SW stayed about the same height they had been for two hours, and the anvils got enticingly dark and thick to our W. A check of radar during a brief data-availability interlude, however, revealed a very messy multicell-supercell clustered structure that was starting to accelerate SSE across WY and surf its own outflow.
Rather than make a mad run 100 or more miles to our S to get ahead of the charging convective mess, while adding 4-6 hours to the journey to get near or past CYS (and well out of our way) then back up, we decided to take a more leisurely approach. We remained on the planned westerly track, let the growing convective mass gather its cold pool and pass off to our SW, then slip in behind its bowing forces of rampage and see what storm light would greet us. This choice didn’t disappoint!
Appropriately named on this day, the Thunder Basin National Grassland hosted a spectacular display of mammatus (looking overhead at first, then toward the S). The amazing mammatus field evolved into sinuous forms resembling pods of swimming marine mammals (view with landscape foreground), as it moved fairly rapidly southward across the open rangeland apace with the parent MCS that, by this time, was blasting parts of SE WY with no mercy whatsoever.
We stood in cool outflow air, thoroughly immersed in the resplendent scene passing off toward the southern horizon, until sunshine came out and limited contrast. Once the convection and mammatus departed, so did we, shuffling off to Buffalo–Wyoming that is, via Gillette and I-90. A fine dinner in town and a day in the Bighorns area lay ahead.
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Our PING trail for this day.