The Carhenge Supercell

August 18, 2008 by
Filed under: Summary 

Near Alliance NE
17 Jun 8

SHORT: Intercepted beautiful classic supercell N AIA, storm became outflow dominant, picturesque sunset at Carhenge.


Techno-Frustration in Colorado

The day began in electronic ignominy in DEN, as we found ourselves suddenly saddled with a bad air card and no weather information from which to compile a morning forecast. The night before, I began leaning toward the NEb Panhandle based on somewhat stronger forecasts of flow aloft and of deep-layer shear, but it wasn’t a strong preference. Meanwhile the card was unable to connect to the network despite 4-bar signal in its own software.

The hours passed from morning through mid-afternoon, frustration growing through phone calls to so-called “support” and a lengthy visit to a local AT&T store, which (to make a very long story short) bogged themselves and me down with tremendous heaps of recordkeeping red tape in addition to troubleshooting the bad air card. Unable to exchange the card free without a new contract (which I did not want), and needing to get the hell on the road, I bought another one out of hide instead. Then came another 45 minutes of hassle getting it to work, while the senior “techie” dude on staff looked over my shoulder, had me try this obscure setting and that, uninstalled/reinstalled various drivers and software, and often, simply scratched his head in utter bewilderment.

Any wonder why I have such an aversion toward techno-chasing? Every year, something goes terribly wrong with completely different and unrelated sets of hardware and/or software, and I end up wasting hours and hours on error messages, malfunctioning equipment, and mysterious problems that invariably result in huddles of “support” types offering nuggets of encouragement such as, “Wow, I’ve never seen this before. I don’t know what’s wrong.”

Finally, at least 2 hours after I had hoped to leave, five hours after the trouble began, and a couple hundred bucks poorer, we had a working air card again and were on the road.

Ignoring a Powerful Left-Mover

Still simmering with frustration, I had looked at very little information, and fraught with indecision, finally picked the NEb Panhandle option over the eastern CO option based on largely a day-2 forecast and gut feeling.

It worked. The difference between frustration and elation on any chase day is a magnificent Great Plains supercell. It wasn’t easy, but it was worth all the trouble and then some. As we headed NE up I-76, we saw what looked like slow-motion thermonuclear convective eruption off to our SE, S of I-70. To our relief, it turned out to be a powerful left-moving supercell — so intense, in fact, that it compelled GLD to issue TOR warnings. From a distance, the sucker looked great aloft, with big overshoots one after another. On radar, it sported a northward-extending hook, looking every bit the mirror image of any butt-kicking, classical, cyclonic supercell. Shortly after that storm finally hit stronger CINH and died, another formed to its N, also a left-mover.

Reserve a Room, then Chase!

We kept going into the NE Panhandle, watching initially promising storms near Harrison fizzle for a long time, then finally evaporate into a baseless carcass and float away. Anvils from other storms could be seen way off to the NNW, just above the horizon and in the Black Hills. We continued N, aiming to get a room in AIA while watching that Black Hills development in the event it peeled off the hills and headed SE.

Meanwhile, we noticed a huge new convective eruption off to the NE, inaccessible to us before dark because of the road voids of the Sandhills, but beautiful no less. It developed huge overshoots, a ring-of-Saturn anvil wrap with long backshearing, and a thick flanking line. This storm eventually resulted in a few tornado reports in them thar (sand) hills.

We grabbed a good, cheap motel room in AIA, then looked northward with amazement. The complex rolling SE from the Black Hills redeveloped westward in discretely propagating flaking towers that in turn exploded into a new supercell with classical backshearing, overshoots, knuckeles of inverted convection, a flanking line and (as we closed in) wall clouds. We stopped to shoot the towers behind Carhenge, then headed N another 12-15 miles to a great vantage point where the Carhenge road (old US 385) turns NE as NE-87.

A Great Plains Supercell – Rare This Year

The initial wall cloud got undercut by outflow, but a new, small, tightly wrapping, lower-based cloud mass developed on a new occlusion to its E (our NE). The whole spectacle — the High Plains storm we’ve been wanting all year — looked great through a wide angle lens, viewing N up a gravel road that neatly bisected sunlit fields of verdant wheat.

We also got zoomed shots of the new meso in all its many evolutionary forms. Initially sporting a tail that pointed under the vault, and toward the forward-flank core, a very tall, slanted wall of convection rolled up its E side with amazing speed. The upward motion was some of the strongest I’ve seen, but the storm’s cold pool obviously was strong enough to doom the new circulation in short order.

Before being completely undercut, the storm briefly tried to wrap a tight, low-hanging vortex of some sort under the tall, scupted wall cloud (here’s a deeply enhanced zoom) but nothing we could confirm as unequivocally tornadic. Still, we fired off shot after shot of excellent structure and rather unusual cloud formations in the warming hues of near-sunset. At one point, the undercut mesocyclonic cloud mass took on the form of a big, rotating bubble or inverted polyp beneath and to the left of the vault.

Back to Carhenge

The cold pool undercut the entire updraft area, splashing a multicolored mélange of scud and elevated convection across the sunset sky. And best of all, a good deal of this visually tasty treat was going on while we were back at Carhenge. Elke and I took lots of shots of Carhenge’s various oddities (e.g., metal dinosaur skeleton and steering wheel planted in the ground) amidst a colorful backdrop that changed minute by minute. The day was saved, ultimately becoming one of my two or three favorite chases of the season.

We got back in town in time for a great celebratory dinner at Ken and Dale’s Steakhouse in AIA. Food and service both were excellent, and they’re open ’til 2130 MDT. [Attention BC or Alnado, for your next excursion to the NEb Panhandle: They serve Blue Moon and Boulevard Wheat brands of “shasta.”]


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