Washing Two States

February 5, 2014 by · Comments Off on Washing Two States
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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.]

Three States of Strangeness

July 6, 2010 by · 1 Comment
Filed under: Summary 

Slapout OK and vicinity
13 Jun 10

SHORT: Observed entire lifespan of supercell from SE of Dumas TX to near Coldwater KS including at least one tornado near Slapout OK. Also observed floods, beautiful clouds and bizarre cross-country cycling experience.

LONG: It was just another ordinary, ho-hum chase day with a rain-wrapped tornado to our south moving east, uncanny resemblances between the Texas Panhandle and the Everglades, a house propped up by a Frigidaire, and an Austrian bicyclist riding across the prairie to the beat of techno-dance music from a German-speaking mobile DJ. Nothing special or different here…

The strongest combination of moisture, instability, lift and shear was forecast along a segment of the former cold front (now gone quasistationary) from SW KS to the eastern TX Panhandle, dependent strongly on how far S storms could backbuild in a manner sufficiently discrete to permit cyclic mesocyclogenesis and greater potential for tornado development. The outflow-reinforced boundary lay from just S of Dumas to near Coldwater at 15Z, and wasn’t going to go far except where effectively shunted E by localized convective outflow pools. The 12Z AMA sounding had a very weak cap atop anomalously large dew points, with clearing skies, so early initiation (perhaps even before noon) was virtually certain.

After leaving our lodging, the question of the day became apparent:

Riddle: What do Chuck, Keith, Texas Beef, and Natural Gas have in common?

Answer: All are names of roads crossing TX-152 within 10 miles E of Dumas.

Heading E from Dumas toward the boundary, we saw towers already arising along it to our SSE by 1130 CDT (1630Z) — these would evolve into the eventual Perryton-Slapout area supercell. We got on the warm side of the boundary between Borger-Pampa, as the same towers deepened and glaciated to our NW. The chase was on, and it was only noon! The visit for fuel and burritos at a Pampa Allsups had to be succinct, so we could head N toward the projected storm target of Perryton.

Once back up out of the Canadian Breaks and atop the Caprock again, we found flooded fields everywhere from the wet spring, led by the previous day’s egregiously profuse rains. These cowboys S of Farnsworth had to herd their herd onto an island in what clearly wasn’t supposed to be a lake. Evapotranspiration was a given on this day! Every time I got out of the car — curiously, except near the tornado — mosquitoes descended in voracious plumes, bloodsucking varmints eager to draw sustenance from anything warm-blooded, and especially from storm observers. I wondered how many “skeeters” ended up advected into supercell updrafts and entombed in the cores of hailstones.

Our towers grew into a fuzzy supercell with a CAPE-starved appearance near Farnsworth, slightly behind the boundary. It probably was surace-based, but not in the best air mass at the time, but did exhibit occasional but not particularly strong cloud-base rotation from broad lowerings (looking NW).

Meanwhile, strong cells were firing back down between Dumas-Pampa again, which we easily could intercept if this supercell fizzled. Instead, updrafts continued to develop in a break between our activity and the southern convection, merging in with the rear flank of the nearby storm. It all remained rather disorganized for about an hour, backbuilding at a rate nearly equivalent to its translation up the boundary, but with a slight eastward net component toward Perryton. We headed S of Perryton and down a submerged US-83 before the storm reached the area. Trucks in front demonstrated the shallowest path through the dead-still water, and that the road remained intact beneath; this is where driving a high-clearance 4×4 pickup came in handy. Such positioning would get us into position to intercept the southern storms if this activity couldn’t get better organized, or if it did, to head E and N to stay with the original convection, without dealing with the town and nearby flooding again.

Our adjacent storm developed a large, sculpted shelf cloud, made even more scenic by the foreground of the huge flood S of town that I called Lake Perryton. The south side of the storm sported a classic shelf, while the N side still wanted to be a supercell, with a tail cloud and occasional, weakly- to non-rotating lowerings. None of this, land or sky, looked much like the High Plains that it was!

Most of all, this did not look like a storm that soon would produce tornadoes. I was getting impatient with it, but instead of bailing S forthwith, I moved a few miles away and examined an abandoned house S of town with an eye back to the N, while stiff, cold outflow winds pressed down adjacent wheat. Good thing we didn’t give up on the storm, too, as it started to look better-organized and more like a supercell again (wide-angle looking N over Perryton). Its own outflow had carved out a swath of convection-free air upshear, while SE winds to its SE maintained good storm-relative inflow. Looking N from SW of Booker, a very well-defined clear slot and wall cloud appeared, and we knew we had to keep this storm in our sights.

About 10 minutes after this shot, taken looking NW from just E of Booker, the mesocyclone region became rain-wrapped from our perspective, then immediately spawned the long-lived supercell’s first tornado, visible mostly to observers who buried themselves deep into the immediate mesocyclone area on muddy backroads. By then we were repositioning E, then N, to stay ahead of the storm.

Recognizing this as an evolving, tornadic HP situation where one needs to get tucked into the notch NE of the mesocirculation to have the best shot at seeing a tube, we set up shop on US-412, in the OK Panhandle, between Elmwood and Slapout. That road provided a ready east escape, an option not available last time I was in a similar situation (with Rich T on 19 May). While watching the accelerating supercell approach, we spotted and photographed another abandoned house, this one strongly dependent on an antique, rusty refrigerator for its survival! When that porch overhang goes, the rest of the structure won’t take long to follow it down into the weeds.

We moved uphill and N 1/2-mile, watching the storm approach. A partly rain-wrapped, rotating, bowl-shaped lowering appeared to our SW (wide-angle view at 1611 CDT/2111 Z, left side) that looked like it meant serious business. We needed to get back down to US-412 then uphill again to the E, in case that turned tornadic (it probably was already), and in case we had to make the great escape. On the way down, we spotted VOF Doswell roaming the grounds of the very same house, but didn’t have time to stop for idle chitchat.

Just after we climbed E and parked beside 412, a brief funnel and some diffuse multivortex filaments appeared under the lowering at 1616 CDT, just before I could shoot. Although the interceding, non-condensational stage lasted a few minutes afterward, I believe this was one continuous, tornadic circulation with the next stage, which manifest as a bulbous, tapering cone, then a well-defined and rain-wrapped cone with filamentous elements whirling beneath. By 1620 CDT the visible tornado became elongated, tapered, curved, narrower in appearance (normal and wide-angle views, by which time the tornado was to our S, moving E). We lost sight of the increasingly ill-defined tornado in wrapping rain to our SSE at 1622, by which time the onset of precip overhead (in the inner-notch region) compelled us to bail E on 412.

Now look at any of the wide-angle tornado shots and imagine the tornado away. What do you see? Otherwise, it looks like an outflow-dominant, rather junky storm organization with a big gust front and some pretty turquoise coloring on its N side. I’ve seen perhaps hundreds of similar-looking storms with no tornado wrapped in there behind the ragged shelf cloud; but in this case, there it was. And that’s all the supercell had left in a tornadic sense.

From then on, the storm’s successive mesocyclonic occlusions ingested excessive amounts of rain and outflow for tornadogenesis. We weren’t sure of this yet, of course; so we zigzagged N and E toward Laverne, meeting Howie along the way (action shot) and nearly getting struck by a staccato CG — the first among a sudden barrage that erupted immediately NE of the mesocyclone(s) in an area heretofore bereft of such a deadly menace. The bolt in question, which was so close I couldn’t tell the direction it hit, gave off an audible “snap” a split second before the simultaneous flash and slicing report of thunder. That momentarily disturbing sequence sent me leaping back into the vehicle glad to be alive and unharmed! I wonder if the snapping noise was the audible effect of a ground-up discharge from some close-by object that preceded the actual return stroke by a fraction of a second.

Shortly after Howie left and before encountering the CG, this shot revealed a dark, HP “stormzilla”. Notice the stubby, translucently rain-wrapped funnel at lower left, looking WSW from N of Slapout (heavily-enhanced crop-n-zoom). That highly suspicious protuberance emerged at 1640 CDT from some heavier precip. It also resided beneath a small, obviously rotating tail/collar feature rolling northward along the E face of the storm, toward a broader but weaker mesocirculation in the dark area to its right (N). We cannot be sure whether or not this was a brief tornado.

Those were the last shots we took from the storm’s inflow region. It started to gust out, merge with adjoining convection, and evolve a bowing feature as it headed for the area between Laverne and Coldwater KS, hot on our tail. With a central-northern plains target to reach in a couple of days, our minds turned to the potential photo ops on the backside of the complex, so we rushed up to Coldwater and let the northern part of the storm roll over us with likely-severe gusts and a barrage of subsevere hail. After the requisite inland-hurricane experience, we cruised WNW toward DDC for lodging and supper.

Along the way, we noticed a peculiar and wonderful combination of visual effects: underneath the MCS’ trailing anvil (not seen in the photo), laminarity along the top of the boundary layer, marked by a hazy delineation, and backdropped by pastel light from and through convective towers. Seldom have I witnessed such a combination, soothing in its beauty. Then things got [i]really strange.

As we stopped to watch and shoot that scene, a few miles SE of Ford KS, a distinctive male voice could be heard, slowly rising in volume. Elke asked me what I said; I hadn’t been talking. In a few more seconds, the source became apparent: a car slowly driving southeastbound toward us, on the shoulder of US-400, lights on, following a cyclist. The cyclist, dressed in skin-tight uniform covered with colorful sponsorship logos, rolled on past, followed closely by a car even more festooned in corporate logos. These, however, mostly were unrecognized ads, and the voice booming from the car’s loudspeakers was German! It was hard for Elke (a native German-speaker) to make out what he was saying, however, beneath the pounding beat of Euro-tech dance music also booming from the speakers. It was a rolling DJ, following a European cyclist across the Kansas prairie into the backside of an MCS!

We stopped in Ford, and right there at the convenience store was an RV parked, with many of the same logos as the weird cyclist/car tandem. Overcome by curiosity, Elke and I asked them (well, she did, since she spoke their language). The cyclist was from Austria — indeed, from the same general area as Salzburg, where Elke was born. He was riding across the USA from San Diego, and was only about 8 days into the trip. This means he had ridden well over 100 miles a day, including over the Mojave Desert and the mountains of southern Colorado. You have to respect that! They exchanged pleasantries, but seemed disappointed when she had to answer negatively to their question about where a good dinner could be found in town. For that, for them, it was either head back to Dodge or go all the way to Pratt…

After our own good dinner (a celebratory steak) in DDC, we parked on a hilltop W of town for a short-lived but gorgeous display of mammatus in the sunset light. The clouds glowed somewhere between champagne, iced tea and bronze on the spectrum of hues, and made for a marvelous conclusion to one of the more bizarre but enjoyable storm-intercept days in a long time.