Smith Center Tornadic Supercell

November 14, 2013 by · Comments Off on Smith Center Tornadic Supercell
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Smith Center, Esbon & Mankato KS
27 May 13

High Plains Therapy, Day 4 of 5

SHORT: Wild day. Intercepted tail-end storm W of Smith Center KS that started CL and became messy HP, saw at least 3 tornadoes therewith. Fateful hail later encountered near Mankato.

LONG:

Prelude to action
Three days of this weather pattern had graced us with some outstanding storm structure and lightning in Colorado, Nebraska, South Dakota and Nebraska again. On this fourth day of the five I could chase, we started out in Grand Island for what promised to be a fairly short trek into extreme northern KS–me in one vehicle and a lot more protoplasm in the other: DF and Samara, “Downtown” Brown, Ross da Boss, and intrepid leonbergers Porthos and Trego. In my vehicle–music, calm sailing, and the hum of the road. In theirs–canine farts…from very, very large dogs.

Strengthening deep-layer wind profiles, the best low-level moisture content of the warm sector so far in the pattern, strong CAPE, a deepening surface low over western KS, and a quasistationary baroclinic boundary near the KS/NEb border, all made the target zone fairly obvious. The dryline was a possibility, but with capping a major concern, so it was downshear boundary or nothing for us. Wind fields certainly would be favorable for supercells. Lower LCLs than previous days amidst enlarging late-afternoon hodographs offered some glimmer of hope for a tornado if the storms first formed, and the modes didn’t get too messy too fast.

Unfortunately, with such a readily apparent target would come throngs of actual and wannabe-chasers, likely followed by looky-here locals, and we knew this. Finding safe navigation options off the main roads would be important to minimizing the hassles and hindrances to safe storm observing posed by traffic jams. Yes, traffic jams in rural KS! How sad is is that we have to consider this anymore? Still, I wasn’t about to let that ruin my enjoyment and appreciation of what nature had to offer, if I could help it at all.

After a long wait N of Stockton, we finally watched several towers arise to our NNW and NW, initially elevated N of the boundary but deepening into cumulonimbi and backbuilding. Meanwhile deep towers fired to our S and SE, in the warm sector E of the dryline. The latter didn’t benefit from as much forcing for low-level mass continuity as provided by the boundary, but had access to higher surface-based CAPE, at least at first. We wandered S and E, monitoring and remaining in play for both areas, when the northern storm cluster finally backbuilt close enough to the surface boundary for Tail-end Charlie to get really happy.

Tornadic stages

Overshoots and thick towers pumped through the persistent southern storm as we turned N out of Osborne toward Smith Center. We got a good view of the initially high base while approaching Smith Center, then set up just W of town with just a few minutes to observe the broad but increasingly well-organized updraft region before the flanking gust front would reach us.

An otherwise undistinguished area of the cloud base roughly in the middle of the last shot, between precip areas, started to rotate quite noticeably. Why? We didn’t notice any particularly telltale signals, such as an antecedent RFD cut or obvious occlusion process. Maybe this was the stretching term at work–a “nonmesocyclone” tornadogenesis process in a supercell, fortuitously located under an elongated updraft area and ravenously sucking a straw of horizontal vorticity. In any event, a weak tornado formed–a dust whirl under the little area of cloud spin, so feeble at first that it took us a couple of minutes of staring to be sure. There was a minute or two gap between obvious dust whirls, but with continuity of cloud-base rotation above, I considered it one tornado with a vortex too weak or too vegetated at the base to raise dust in that intervening stage. Off and on, but mostly on, the little tornado that could stayed visible, lasting for six minutes before being plowed under by the rear-flank gust front of a low-level mesocyclone deepening to our N.

With the supercell changing character and moving abeam of us, it was time to “head east”–and I don’t mean the ’70s rock band. The warning and tornado report attracted swarms of chasers and pseudo-chasers from several counties around, many of whom could be seen on Spotter Network animations about-facing to this storm as soon as the red polygon appeared. US-36, E of Smith Center, turned into a long, eastward-slogging train of vehicles paralleling the storm just to its S and SE. For a little while, we were caught up in that mess, and had trouble finding good vantages.

We needed one when an area of low-slung scud to our N and NNW, under a cyclonically turning inflection notch of the updraft-downdraft interface, started turning itself as it rose off the ground. The persistent, obviously but slowly rotating cloud column was in contact with both ground and cloud base for about a minute. The whole very weakly tornadic circulation (located just N and NE of Bellaire and NW of us ) lasted about 3 minutes.

Farther N, the storm cranked up a robust mesocyclone, but one hard to see from the S, through intervening precip. Finally, this storm was getting serious and bidding bye-bye to the “cheesenado” phase. Our vantage wasn’t ideal, and we wanted to get E and N to reposition ahead of the new, deepening storm-scale circulation. Several minutes of waiting for a hole in the US-36 traffic didn’t help. As a result, we did get N on the alternating paved/dirt road into and out of Esbon, but not in time to see most of the lifespan of the big, rain-wrapped tornado NW of town.

Instead, we popped N out of Esbon barely ahead of a deep, dark, circular drum of rotating precip, churning menacingly and moving ESE directly at us. With no vehicles driving toward our position (but several high-tailing it away!), and a narrow but very passable road upon which we had just driven as a return/escape outlet, we safely executed requisite 5-point turns to flip back southward and, as a Texan like me would say, “Git the hell outta thar!” After they finished the turn and as I was amidst that process, I heard Keith yell over the radio, “Tornado to the west!”

Sure enough, inside the orbiting moat of heavy rain, I could make out a low-contrast, wedge-shaped mass of darkness, itself rotating furiously. Seeing that the E rim of the meso still was W of us, though not by far, I radioed to the now rapidly fleeing Dudes, Dudette and Dogs vehicle: “Go ahead south! I’m gonna take 30 seconds to shoot then I’ll get the #%^! outta here!” As I parked and jumped out, the mass (which indeed was the infamous Lebanon-Esbon tornado) narrowed to a barrel shape, then by the time I did shoot, a thick cone, getting lower in contrast again (enhanced version of last shot) and still densely swaddled in precip.

Meanwhile a newer and rapidly strengthening mesocyclone was whirling with considerable vigor to the N, raising dust and sucking it in, wrapping big gobs of precip, who-knows-what going on inside. I could have sworn I saw some vortices merry-go-rounding in there, but contrast was too poor to say for sure. No tornadoes showed up in storm reports during that phase, but at a minimum, it was a very intense “meso on the ground”. The southern, older, tornadic and deeply occluded circulation still was moving generally toward me, the tube narrowing to the extent I could ascertain. [Storm surveys later showed the Lebanon-Esbon tornado dissipating right before it reached my road.] Still, not wishing to play chicken with a beast like this (the storm always decides who wins that game!), I jumped back in and gunned it southward also. Everything since the 5-point turn occurred in less than 45 seconds, 15 longer than estimated: stop, jump out, shoot WNW at occluded/tornadic meso, run across the street, shoot N at new meso, run back to vehicle, throw ‘er into gear, slam the pedal down and bust south.

Adventures anew

Apparently, my storm-intercept companions used a great deal of haste in their escape; for by the time I reached the next intersection, they were out of radio range. While I turned E to stay ahead of the rear-flank gust front of the new meso, it turns out that they had kept going S back toward US-36. My east road, though gravel and dirt, was outstanding and very firm for a few miles, allowing me to gain a welcomed cushion by the time I reached Burr Oak. There, I briefly stopped to examine and shoot the main mesocyclone area to the NW, now deeply wrapped in a north-Texas-style HP stormzilla.

Opening up some space between me and the rear flank also became crucial when two things happened at once, E of Burr Oak:
1. A heavy shower that had formed to the S passed directly over the road ahead, and
2. Preceding the next paved N-S option, I encountered a 2-mile stretch of the same “road”, which previously had been a deeply rutted strand of slop, and now was being rendered horrendous by the shower.

Thank God and Ford for high-clearance 4WD and the ability to use it properly. Prior practice mudding and sand-driving paid off here; lower-set SUVs (4WD or not) and any sedan would have ended up high-centered past the axles in that nightmarish quagmire. There was serious white-knuckle driving down a certifiably awful track, among the handful of worst mapped roads that I’ve experienced. I was counting the tenths of a mile on the odometer, trudging along through the viscous morass, not daring to stop lest I lose momentum, wheels flinging giant gobs of goop every which way. At least there were no other chasers on that wretched stretch…for good reason! Somewhere in that ordeal, I got brief coverage and a phone call from my comrades, but was in no position to stop and answer, requiring full-on concentration and the use of both hands for every millisecond.

Finally I emerged on to the hard, dry N-S road, likely shedding well north of 200 pounds of mud to rain and centrifugal forces as I zoomed off southward toward Mankato. One last look back N at the HP storm gusting out, then a peek at a new Cb forming to the SE, and what appeared to be a newer, elevated supercell to the W (atop outflow from the big HP), dictated the next step superbly: get SE.

Upon reaching Mankato from the N, I got back into reliable cellular coverage and re-established phone contact for a meeting E of town. By this time, the elevated supercell was moving into Mankato. Thinking we had a decent shot at a spectacular sunset on the back side of the convective mass, and that most of the core of the ESE-moving storm would clear town by the time we went back through, that’s what we tried. We tried too soon.

Skirting the N edge of the main core, we encountered mostly heavy rain and marginally severe hail, except for the large ice bomb or three that bounced high in the air off the ground. Well, a few bounced off vehicles too. They took a 3-incher to the windshield, and I heard and felt one or two really fat ones clunk the roof where decent dents later were seen. Fortunately it was over quickly, but we were just a little too hasty going in. I took the blame for this bad call, because (clearly wrongly) I thought the meat of the core was S of US-36. The Dudes, Dudette and Dogs crew were upset, and rightfully so.

Unaware to us at the time, and purely by serendipity, this would turn out to be one of the best things to happen to us all, because it forced them to limp into the nearest big town (SLN) to get a windshield replaced, effectively nixing their prior intentions to chase in Colorado the next day. Meanwhile, the sunset wasn’t calendar-worthy, thanks to light blockage over most of the sky from clouds farther W, but was beautiful and enjoyable nonetheless.

As for me, I didn’t feel like driving all the way to SLN in darkness and deer crossings, and instead got a cheap room at a little motel in Smith Center in time for a late dinner. Though this chase now will be known forevermore as the ideal setup event for the nest day’s feast, in its own right it was a fine fourth part of five in the journey of High Plains Therapy.

When Atmospheric Beauty Attacks

November 7, 2013 by · Comments Off on When Atmospheric Beauty Attacks
Filed under: Summary 

Arcadia NE
26 May 13

High Plains Therapy, Day 3 of 5

SHORT: Intercepted another spectacularly structured supercell, this time a mostly LP storm near Arcadia NEb. Missed some of the best photo opportunities due to close lightning strikes but still loved the show.

LONG:
On the day after a tremendous structure-fest in southwestern SD, we headed back toward the warm sector in central Nebraska in hopes of yet another. To summarize, the setup promised adequate low-level moisture, marginal to sufficient near-surface flow, favorable deep shear, and rather nebulous low-level foci for initiation. I was traveling in a caravan with the Dudes, Dudette and Dogs crew (David and Samara Fogel, Keith Brown, Ross Weitzberg, Porthos and Trego).

Following a long trek down from CDR, we consumed a meal and hung out in and near LBF, hoping for initiation that would occur close enough to the S or E side of the Sandhills to keep storm motions in more tenable observational country. The day was getting late, the sky disturbingly devoid of deep convection. That worrisome lack of focus kept us guessing and scanning the skies–good old fashioned “going visual” for clues to earliest initiation stages, whatever the data may show.

While sitting on a hilltop N of town, we finally saw that hope–a very young but rapidly deepening tower to the distant ENE. Given the obvious cap breach and favorable environment over there, we thought it would mushroom upscale, and as we cruisd back down through town and started cruising E on I-80, it did.

Even while still 50-60 miles out, as the magpie flies, the main cloud updraft’s high-based but striated character became readily apparent. Despite enjoying the visual treat of this storm’s development from a distance, including some classicaly splashing overshoots, I was wishing for the vehicle to sprout wings and a couple of Pratt and Whitney jet engines to get there sooner.

Roads dictated otherwise, however; we had to proceed in an Allen wrench-shaped path ESE to E on I-80 then N on US-183 to our long-awaited first rendezvous with the gorgeous storm near Ansley. As viewed from the S, the banded LP soda can spun its way off to our NE in the lowering sunshine, compelling us to get off to its E for a more contrast-friendly backlit perspective.

Performing that maneuver took us directly under the S rim of the updraft, which actually had a lowering base and some thin, faintly wrapping precip curtains with embedded hailstones of mostly subsevere size. Low-precip doesn’t mean no-precip! By the time we got E of the storm, between Westerville and Arcadia, we thought we were going to be in fat city, photographically, with the storm putting on an increasingly evident show of sweeping striations and bands. We had to get far enough E to get it all in wide-angle view, plus get out from under a CG bombardment that seemed to follow us away from the storm.

Unfortunately, opportunities to shoot safely were few and far between; so I didn’t get too many shots of the storm during any of 2 or 3 stops in this stage. The supercell’s anvil, augmented and thickened by that from more distant storms to the NW, would not stop flinging staccato, forked CGs all around us, many miles from the updraft, jagged arrows of Zeus fired disturbingly close and often across a wide area SE and E of the updraft. Usually in my experience, such blistering barrages are temporary, lasting just a few minutes until newer updraft cycles redistribute charge and favored areas shift. Not this time…the white-hot fusillade of electricity just kept coming and coming and coming…

Having gotten frustrated at being trapped in the car for many minutes, with some unwelcome visual obstructions to ideal shooting at the parking spot, I tried to time the last shot versus the bolt/recharge process. Often that works, but not this time. Having preset aperture and metering in the vehicle, I ran out to shoot this absolutely jaw-dropping structural exhibition right after the previous flash, then about-faced in less than 10 seconds. I barely started back when…CRACK-SLAM!!!!…a CG hit so close I couldn’t tell where. All I knew was that I was still alive, and a quick glance around at the other people revealed nobody lying on the ground. This warning shot sent all of us fools who were outside diving right back into vehicles for survival.

Warning heeded! Keith later told me he was across the highway and happened to see that CG hit in the plowed field just S of the road. Instead of frying one of us, it simply zapped some dirt. Enduring skull-rattling explosions of countless more close strikes, we had to wait until the storm moved several miles farther N before even thinking of sneaking outside again. I was tempted to drive several miles E (where some other observers did get amazing CG + updraft shots), but 1) was unsure about vantages in choppier terrain near Arcadia and 2) noted a gentle E and NE shift in the CG activity centroid.

So, we waited out that vicious attack a bit longer, then gingerly started to dare to shoot some more as strike frequency waned somewhat. A final cycle of CGs and a brief repositioning led to deepening twilight, and finally some confidence in shooting outside the vehicle with a tripod. The storm, now to our NNW and N, still seethed with nearly continual lightning, offering shot after shot after shot that contained some sort of lightning or another.

Here is a JavaScript time lapse of larger, full-width versions of those shots, and others in between, over a span of 9 minutes, for your viewing pleasure. Please set the speed bar almost all the way to the right for best effect. I wouldn’t know first-hand…but just as a guess, staring at that high-speed animation constantly after imbibing in intoxicating substances might yield some wild mental experiences.

We headed back to Grand Island for the night, enjoying a lightning-illuminated mammatus show in the rear-view, but too tired to bother stopping. I was satisfied–quite so, actually–both to be alive and to conclude a challenging but fulfilling third day of five in the rejuvenating regimen of High Plains Therapy!

Spiraling South Dakota Sky

September 2, 2013 by · 1 Comment
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Box Elder SD
25 May 13

High Plains Therapy, Day 2 of 5

SHORT: After a long wait for storms to form further S, intercepted absolutely spectacular late-day and sunset supercell N through E of Rapid City.

LONG:
No alarm went off, but somehow, despite a long travel and chase day before, I snapped awake at the unusual hour of 10 a.m. CDT (9 a.m. MDT), looked at some diagnostics and forecast information, chose a preliminary target between CDR and the Black Hills, and headed up to OGA for breakfast and more data perusal at the Denny’s free wi-fi. That’s about the only Denny’s I’ll patronize anymore; it’s one of the very few that’s clean, friendly and spacious, with good hot food and good wi-fi.

Upon leaving my lodging, I discovered that my dome lights wouldn’t turn off, regardless of all doors being solidly shut. Fortunately, they did go out via chipset-forced automatic shutdown about 12-15 minutes after turning the vehicle off in OGA, assuring me that:
1. My battery wouldn’t go dead, and
2. I wouldn’t have to go under the dash and pull a fuse (that also powered other things) every night or disconnect the battery to prevent that very outcome. Both the owner’s manual’s fuse guide and online fora for my vehicle were vaguely worded on [i]which specific fuse to pull, of course, making it potentially a trial-and-error ordeal.
Still, this was a bothersome problem, especially for night driving. The fix (bad switch buried inside the door) was too time- and tool-intensive for where I was and what I had, and would have to wait until getting back home. Fortunately I hardly noticed the continually running light by day. This will matter later.

Meanwhile, as the chase crew with whom I was to meet later headed N through KS, I browsed data and maps, determining three targets–one in central NEb, near the S rim of the Sandhills, along an old outflow-reinforced warm front. With a strong cap and convergence along the boundary likely to weaken through the day, huge CAPE but marginal shear, I ruled out that high bust-risk situation for more sure but more moisture-deprived initiation farther N. The dryline near the S side of the Black Hills looked interesting, on the N edge of a narrow moist plume, but could have cap problems. Backed upslope flow in the northern Black Hills region and western SD also looked promising, but more distant, considering the next day’s potential back in Nebraska.

North to CDR it was. While watching the dryline towers bubble up and down in CDR, I was met by the amazing chase crew of David Fogel, Samara Fogel, Keith Brown, Ross Weitzberg, and massive doofus leonbergers Porthos and Trego, who drove up from a chase the day before in NWTX. Yes, that’s four persons and two person-sized dogs, all in one SUV. Somehow they make it work well, occasionally intolerable bouts of canine flatulence notwithstanding.

Seeing the towers gradually get less impressive with time, while we baked in the sun and storms fired “way up” in west-central SD NNW of RAP, was discouraging. The anvil looked like it was a million miles away, barely above the horizon, and we didn’t relish the prospect of that being the only show. Then the storms consolidated into a remarkably well-“armed” supercell, with a hook echo shaped much like a flexed bicep, forearm and fist.

Enough of this…our southern target area was turning into a smelly atmospheric turd. This left no other option but to sit and sulk, or zip almost two hours northward to and around the eastern Black Hills, in hopes something would be left of the SD storm before sunset.

We did, and there was; but it didn’t seem so at first. Though moving ESE to SE over some great landscapes N of Ellsworth AFB, the storm looked rather high-based and featureless. At a stop, I shot the above photo and read a couple of online updates from fellow storm observers about how interesting the storm had looked and behaved earlier, and how it almost had gone tornadic, despite the high bases. I was thinking, “Great…we get here and turn the storm into mush!”

Presumptuousness of that sort was premature and unwarranted! We actually caught this storm in a down cycle, following a major core dump. Driving in a big loop north then east of the base and Box Elder, we caught up to and passed under the south rim of the storm (mostly dry RFD area). In doing so, it assumed much more classical, banded cloud forms. We got ahead of the supercell and let it come to us at three locations, as it put on a structural feast for the ages. Please enjoy.

1. [i]5 NE Box Elder SD: High-based wedding cake with a dense central core.

2. [i]5 NW Wasta SD: Helical convective spiral atop a flared bell whose base grew outward and more laminar. This was a dream come true–therapeutic to the max–the sort of experience that makes the trek from Norman to western South Dakota well worthwhile! We spent a long time at this stop and let the storm come to us, since some tighter cloud-base rotation became apparent from a flared, triangular wall cloud–the last such attempt before the boundary layer cooled enough to deny suitably unstable inflow.

3. [i]1 E Wasta SD: A sunset extraordinaire! The storm’s main updraft, which had been moving SE, turned back E again–a sure sign it was losing surface inflow and coming more under the influence of winds aloft. This most gorgeous of “chicken necked” updrafts gradually became more stretched and narrow amidst a sublime blend of warm and cool light tones.

Both the storm and daylight faded away, sending us on the road back to CDR for the night, since the next day’s potential looked to be in central Nebraska. Though the storm wasn’t tornadic, we celebrated our amazing fortune of the day with a good dinner among friends at Texas Roadhouse in RAP.

For an hour, the drive back from dinner was another mesmerizing Great Plains experience. A full moon rose over the foothills of the Black Hills, its gentle silver light reflecting off east-facing slopes to the right and silhouetting those to the left. Moonlight bright enough to reveal the green carpet of the rolling grasslands also outlined the edges of the nearby eastern hills in the shimmering fuzz of short-grass prairie, reminiscent of the silver lining of silhouetted clouds. Shadows from the hills to the left curved across the road and over muscular terrain on the west side, lending amazing texture and light form to the landscape–especially for nighttime. That I could see this past the dome light was a testament to how bright the moon was; and I did cup my right hand over the light on straightaways to absorb the experience more fully. These scenes wave through my mind with yesterday’s clarity three months later, sure to stay for a lifetime.

Red and blue lights appeared in the rear-view mirror, flashing brightly. The scene had been a little too mesmerizing, as it turns out. Even though I was following the other crew, and we all were driving somewhat above the speed limit, I was the one pulled over. The running dome light (and a roof light I didn’t know was out) arose suspicion based on a profile. Fortunately the trooper simply wrote a warning–the speed overage wasn’t excessive, he wasn’t out for ticket quotas, and he was satisfied with my honesty about both the lights and why I was there. He seemed relieved that I wasn’t some drug runner–specifically mentioning the presence of several lately, often with malfunctioning lights. We actually had a nice chat about storm spotting, severe weather in South Dakota, and our mutual experiences driving Crown Vics in hail.

Our lodging for the night was the Westerner in CDR–locally owned and staffed, highly recommended for both low price and welcoming service! They accommodated the enormous Fogel dogs and even David himself, which was quite remarkable. 🙂 Impressed by their friendliness and rates, Elke and I would return to the Westerner twice on our trip in June. Meanwhile, I got some duct tape from Ross and covered up that blasted light.

Another day, another adventure, a wonderful second step in a five-step program of High Plains therapy…

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