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.
Sublime and Serene Sandhills Scenes
Filed under: Summary
near Hyannis, NE
16 Jun 13
SHORT: Photogenic nontornadic storms and skyscapes in Sandhills followed by serene sunset in CDR. Most enjoyable Sandhills storm day I’ve had.
LONG:
Forecasting for this day revealed classical trade-offs of stronger shear north, richer moisture south, and the most optimal juxtapositions of the margins thereof being in the least favorable area of the Plains for consistently successful viewing: the Nebraska Sandhills.
Hoping to catch something worthwhile along the edges of the big dune pile, we left the outskirts of the DEN area fairly early, heading NE on I-76 toward a buffet lunch in Sterling, then I-80 to OGA. Boundaries were subtle amidst weak CINH and amble CAPE, and midday to early-afternoon storms erupted almost at once in all directions. “One of [i]those days, I see!”
Convection over, E and S of us was rocketing almost vertically toward the tropopause–a strong sign of the lack of deep shear. The sights of sharp, rapidly rising storm towers beckoned attention; however with all these updrafts blasting skyward in close proximity, a southeastward moving outflow bomb (into even weaker flow aloft) was sure to follow, aimed at Kansas. So it was.
Bidding farewell to the initial eruptions that quickly accreted into a multicellular mess, we plunged northward past our familiar old friend Lake McConaughy, into the heart o’ the hills and halfway to Hyannis. When storm observing in the Sandhills, the higher terrain surrounding the roads doesn’t matter very much as long as
* Tornado potential is low;
* Bases are fairly high anyway;
* Storms aren’t going to be raging bows or HPs that make you run like hell down the few and winding roads that crisscross the area.
Meeting those conditions with success meant the next couple hours were magical. A storm about 60 miles to our N was tornado-warned–but not likely to maintain that structure by the time we would arrive, thanks to a gob of outflow air to its immediate ENE. Meanwhile another high-based cell between OGA and Hyannis, one we could see initiate from I-80, briefly gave us an interesting presentation from the SE and from the E before it lost structure.
Meanwhile the older, stronger supercell hooked hard right and ripped S almost straight down our highway, so we pounded N to see what was left of it. By the time we arrived, still S of Hyannis, the supercell was obviously becoming elevated behind its own and antecedent outflow, based on visual appearance, its mesocyclone broadening and weakening based on looks at volume scans from the Sandhills radar unit. Nonetheless, as it veered back leftward again and passed to our NE and E, the storm offered a wicked skyscape in remarkable symmetry with the undulating musculature of the foreground landscape, a scene quite unlike anything I’ve seen!
One of the greatest aspects of storm observing on the Great Plains is the uniqueness of each storm alone, and especially in its landscape. One never sees the same thing twice, and each new storm is a new opportunity for an experience unlike anything prior. This wild sky definitely was no exception, nor was the next magnificent convective specimen that soon erupted to our NW.
Just in time for the elevated storm to perish, its cold outflow buffeting is with a brisk, clammy breeze, the winds backed around to the SW and warmed some, while the new storm moved resolutely in our direction. This one was marvelous to behold from both sides–the proximal inflow region and the back of the storm.
We jumped back S a few miles and let the storm’s main core (presumably containing severe hail) pass by us to the N and NE, offering a chance to observe the sunlit side. One of my favorite scenes all spring was the one-lane Sandhills blacktop with the rainbow arching over. Another was the rainbow seeming to drop right into a rain-soaked pasture nourishing contended horses.
Standing before the amazing beauty of that storm’s west side, I had an experience best described as immersively transcendent, completely one with the land and sky. After absorbing the full, surround-vision image of what was happening, I closed my eyes, standing with arms wide apart and upward, hands open, in praise for this great gift from above. Deep breaths fully drew in the clean, refreshing, rain-cooled and dampened air, with a sweet aroma of renewal and rejuvenation. Right then, the sun came out, unseen but certainly felt, warming my back comfortably. The easterly breeze of mild outflow, infused with just a few tiny raindrops, gently cooled the front side. The moment felt like a direct connection to heaven, harmony across all physical and spiritual sensations, lasting for probably for just a few seconds but seeming to be much more.
Every good moment has to end, so we enjoyed the last of that one, then headed off toward our lodging destination of CDR with some WY/MT storms in mind for the next several days. Along the way, we encountered some precip from elevated storms just W of Hyannis. We unloaded at our room in CDR (the Westerner Motel is highly recommended…American-owned and run, and very friendly folks!), then headed to the Country Kitchen on the hill for dinner with a view.
Sunset indeed treated us to a splendid display, looking SW across the rolling green hills of the Nebraska Panhandle at some weak storms that erupted on the outflow boundary in WY. I took that shot from the parking lot of the restaurant…told you it had a view! So concluded a marvelous day of storm observing and outdoor appreciation in the Nebraska Sandhills.
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Our PING trail for this day.
Pawnee Grassland Supercell and Sterling Sunset
Filed under: Summary
Cheyenne WY to Sterling CO
15 Jun 13
SHORT: Chronically photogenic storm from CYS to Sterling.
LONG:
We began the day in Ft. Morgan with increasing (but still marginal) low-level moisture feeding two forecast plays:
- The dependable Cheyenne Ridge/Laramie Range region, which seldom fails to pop a storm under upslope flow and substantial surface heating, and
- Palmer Ridge/Front Range area farther S, similarly dependable but under weaker flow aloft.
My privately posted chase forecast discussion read, in part…
“This pattern strongly resembles several that have fired grand supercells off the LAR mtns NW CYS — some with spectacular tubes — though moisture today is a little less than I’d like to see it for tornadic action. Postfrontal winds should turn around after 18Z and go upslope into that area. If a storm can fire over there, it could proceed ESE through the extreme SE part of WY and eventually in an oblique path across the NE CO border…”
That was the scenario we selected; and fortunately, that’s exactly how it worked out. Such success doesn’t happen as often as I’d like, so we should celebrate when it does. On this day, we celebrated with some splendid stormscapes and one of the best Great Plains photography days of the year.
First, however, we ate a great buffet lunch at a highly-reviewed place in eastern Ft. Morgan, away from all the main highways: the Country Steakout. Try them next time you’re in the area, especially if you want to get really full, before a chase. We then trekked through the Pawnee National Grassland on the way to the CYS initiation target. [We would return through this amazing area later in step with the supercell.] Along the way, we found an abandoned farmhouse that showed us decent photo opportunities even at midday (samples: outer wall texture, another outer wall scene, light and shadow through a window and on the floor, more exterior boards).
After that, a lone Cb arose off the WNW horizon, which satellite imagery confirmed was firing off the southern part of the Laramie Range, just as hoped and predicted. We headed through CYS, passing Mike U and a few other chasers along WY-211 (Horse Creek Rd) to find an excellent vantage for the approaching storm, which offered a large and textured but ragged and elongated updraft base.
Peeling itself off the highest terrain and heading ESE, the storm kept that elongated-updraft look after crossing the Colorado border near Hereford. Although this storm flirted with excessive downdraft production and outflow-dominance on several occasions, it was able to maintain just enough proximal inflow to keep from gusting out–remaining photogenic all the while. A view to the E, from the same spot as the last shot, showed multiple, parallel, cumuliform inflow bands feeding into the high base. What an interesting and beautiful process to behold!
Road voids over the buttes and mesas (here spotlit with sunlight against a dark storm background) kept us somewhat distant from the storm at times, and/or relegated to its SW side, but that was obviously not a problem from a photographic standpoint. In fact, we stayed on the western fringes of both the storm’s rear-flank core area and the Cedar Creek wind farm to take advantages of (and marvel at) scenes like this and like this.
Back roads delivered us healthy and well to CO-71, whereupon we headed S to CO-14, stopping along the way to view the gorgeous towers to our NE over the shortgrass prairie. Eastward we moved on 14 to get back near the SE-moving, high-based supercell, which seemed to be accelerating. Daylight fading, we decided to stay in good light and on the storm’s back side as it approached Sterling, and let the rear-flank gust front and its wondrous collection of tinted cloud material pass over the green wheat fields.
Sunset time was a dazzling experience, with elevated storms that were growing to the W helping to cast differential light, shadow and hue across the convective sky to our immediate SE. I had to slap on a multi-stop graduated neutral density filter to offset some of the dynamic range (old-fashioned, I know…but it worked out well). At times, the colors were out of this world…seldom have we witnessed such a variety of light and texture in such a small part of a convective sky! The experience was amazing–parked on a remote, dirt back road with nothing but us, the sky, the cool breeze, and some singing meadowlarks for company. This is why we travel to the High Plains every year.
The convection to the W grew larger and started putting on a fairly furious electrical show after dark, but we had to forgo lightning photography to get Elke some suddenly-needed medicine in Sterling. That wasn’t available, so we headed promptly down I-76 to to the outskirts of DEN for the night, enjoying the flickering light show in our side windows and rear-view mirror while hoping she would be healthy enough to chase the following few days (great news…she was, and we had a fantastic chase in the Nebraska Sandhills the next day!).