Pleasant Diagonal across North Dakota
Filed under: Summary
Rolla and Grafton ND areas
9 Jun 12
SHORT: Small convective towers and beautiful sunset Cb photographed along with abandoned structures and Northern Plains landscape.
LONG: This date loomed several days in advance, even in national forecast outlooks, as not just a potential supercell day, but tornado-outbreak day, across the eastern Dakotas. As time got closer, it became more and more apparent that the wind fields would be there–albeit in a smaller area mostly encompassing eastern North Dakota–but lack of robust moisture would be a major hindrance to storm development. So would capping, for much of the day, despite strong large-scale and frontogenetic forcing.
Elke and I had an additional logistic quandary in that the best low-level shear would be N of the Canadian border. We wouldn’t mind chasing there; but we didn’t bring our passports. So we undertook a strategy that, in essence, was: get ahead of the cold front and tuck ourselves just S of the border to jump on any storms that might develop to our S and mature before crossing the 49th parallel.
I was rather surprised to see the number of Southern Plains storm observers via SpotterNetwork attempting the long and dangerously sleep-deprived overnight trek from Oklahoma, Kansas and even Texas, for what looked to me like an ever more feeble setup for tornadoes. By contrast, we already were in the region and on vacation, with no particular place to be for a few days after the system departed. In fact, we fully intended to stay in ND after this day, until the next northern-stream weatehr system, and explore the state. North Dakota seldom was visited by us before now, and never in-depth, as true appreciation warrants. We had wanted to spend more than a couple of days in ND for many years, and now was the start of that chance!
Originating our trek from Bowman, in the SW corner of ND, involved an earlier-than-usual arousal from bed and crisscrossing the state on a diagonal. Fortunately, ND is not a particularly massive block of land (similar in area to Oklahoma), and the roads are plentiful and in good condition E and N of the Missouri River. Some short-range, convection-resolving models unzipped the front N-S across the eastern third of the state by about 4-5 p.m.; but I didn’t buy it. A simple examination of the 700- and 500-mb charts, surface chart and moisture-channel imagery indicated the strongest lift might not even occur before dark; and supercell initiation would be improbable before 0Z. For once, I was confident early development would not be a problem and storms would hold off before late afternoon, enabling a stop in BIS for lunch and procurement of a much-needed ND road atlas. [Yes, we still navigate chases exclusively with paper road atlases, though we found the BIS Barnes & Noble with I-Phone Google Maps–the best of both worlds!]
We zigzagged NNE from BIS through Rugby, stopping to visit the geographic center of North America. While heading E to stay ahead of the bent-back portion of the cold front, we crossed an outflow boundary from a strong morning MCS that was, in effect, acting as a warm front. Clouds on the NE side of the boundary were scuddy and more stratified than on the warm (SW) side that overtook us several minutes later. As the boundary crossed our location, we noticed that blades in the eastern portion of a nearby wind farm still were facing SE on the cool side, whereas those in the western part had pivoted to face S–a modern manifestation of “reading the wind”. Although those towers near the boundary were unlikely to build into a mature supercell before reaching the border, we had hopes others could fire farther S on the front and move our way.
Meanwhile, we stopped a few times between Rugby and Rolla to pass the time–enjoying the scenery of the Northern Plains‘ post-glacial landscape (closer shot of gaillardias with bumblebees) and that bit of Americana involving an old barn with glacial rocks. As seen from a spot near Rolla, as far N as we ever had been on a chase, convective towers kept bubbling along and ahead of the front to our W, but neither broadening nor deepening appreciably until crossing into Canada. Even then, they didn’t survive long upon crossing the remains of the outflow boundary.
Regarding the day as an increasingly probable bustola for sustained storms, but still wishing to stay ahead of the front, we headed several more miles E into Towner County. It was nearly 8 p.m., still plenty of (low) daylight left, and a few towers were erupting to our distant SE. Those appeared to be along the remnants of the outflow boundary, and a quick glance at a surface map confirmed that. But they also were on a sharply defined confluence line and the E edge of strengthening N-S baroclinic gradient ahead of where I thought the forward segment of the front should be by pure extrapolation of translation. The front was redeveloping (frontogenesis) ahead of its previous position–in effect, jumping E of us!
Zooming E on US-281 and ND-5, we realized that the first cell was moving fast and would pass our longitude before we safely could get there; it became a short-lived supercell just into Manitoba, N of the dying old outflow boundary. When realizing the futility of that pursuit, we stopped to photograph an abandoned farmhouse and barn in the warm, late-day light, with other frontal towers across the background skyline.
More cells fired to our SSE, this time reachable. However, since it would be just a little before sunset by the time we would intercept them along the now eastward-accelerating front, we chose to hold back W a little and photograph them from the side preferentially aglow. By the time we reached a point near Hoople (between Cavalier and Grafton), scuddy low clouds broke enough to afford us great viewing of the spectacle. As the sun set in the NW, a small cumulonimbus just past the Minnesota border reflected brilliantly in the eastern sky, turning deeper shades of peach and apricot before falling into shadow and growing dim. The convection softened, weakened and moved away rapidly after sunset, which was quite late in those parts (9:52 p.m. at our filming location); so we headed to nearby Grafton for lodging and a late fast-food dinner.
Elke and I had started the previous day in Cheyenne, WY, and ended it here in northeastern ND. That’s a long haul! Yet we had undertaken a scenic and rewarding trip, bisecting the central and northern Plains from SW-NE. The journey hadn’t been quite as tiresome as the many miles might make it seem, probably thanks to the many stops and small rewards bountifully scattered along the way. Still, we were ready for a few days of post-frontal rest and relaxation before the next storm-spawning system. I didn’t count on a fortuitous encounter with photogenic cold-core storms the next day…
Wyoming to North Dakota via a Nebraska/South Dakota Dryline
Filed under: Summary
Cheyenne WY to Bowman ND
8 Jun 12
SHORT: Observed dryline towers, sometimes with smoke, near the NE-SD-WY state-line junction. Nice sunset over the SW corner of ND.
LONG:
Three main target areas presented themselves to us as we pulled out of CYS on a sunny morning:
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1. The closest but probably lamest: a high-based, deeply-mixed prospect for short-lvied, late-afternoon convection along the dryline, near the S rim of the Black Hills;
2. A middle play along the NW rim of a narrow plume of relatively righ boundary-layer moisture, collcated witha confluence belt, in the SE MT/NW SD/SW ND area. This had been apparent for a few days–distant but reachable, given the likelihood of a stout cap holding off storm potential until late afternoon.
3. More certain risk for a photogenic supercell or two in central MT, more removed from the richer moisture but in favorable deep-layer wind profiles. his was barely reachable with some long, hard driving and only brief stops, followed by a short night’s sleep and another day of long, hard driving to get all the way over to NE ND. That’s hardly the recipe to be able to stop occasionally and get out to appreciate the Great Plains!
Given the low likelihood of tremendous tornado action in the middle of Montana, we nixed option 3 early and decided to make a conditional play on the first two. We would head NNE to the CDR-CUT area for the dryline, then if it looked unpromising by around 21Z, be ready to zoom up through RAP toward 2WX where at least one high-resolution model (HRRRRRRRRRRRRRRRR) forecast a distinct supercell to develop.
Lunch in Lusk was good–Deacon’s Restaurant is one we can recommend! Appetites satiated, we took a back road–sometimes paved, sometimes not–to Van Tassell, stopping here and there to appreciate geologic formations as well as photograph abandoned structures from up close, in the middle and back a little.
The whole way from Torrington to Van Tassel, we kept an eye on the high-based cumuli accumulating in a persistent area of lift that passed overhead, then shifted E to the Nebraska border in step with the mixing-driven movement of the dryline. This photograph depicts the deepening convection from near Van Tassell WY, gazing ESE toward the dryline. A horizontally narrow but vertically thick ribbon of smoke from the Cow Camp fire in Wyoming (the inferno whose pyro-convection started the Wheatland supercell the day before) also was streaming steadily northeastward toward us, several thousand feet above ground level.
Van Tassell in the review mirror, we headed through Fort Robinson on the Nebraska side, passed through the dryline near Harrison, gathered some rocks on the escarpment E of Harrison, stopped briefly for supplies in Chadron, then headed NW toward the South Dakota border and one skiny but persistently deep tower. When we got to it, the tower obviously was suffering from dry entrainment, but presented a peculiar picture of light and shadow, as seen from underneath the ribbon of smoke and very near the state line.
Unconvinced of its future, we proceeded N beneath the ENE-moving tower’s base, encountering a few raindrops. A small Cb actually did develop briefly as we passed just to its N, and weak reflectivity appeared with it as seen from RAP radar. Still, given the degree of entrainment, and the presence of a few more hours of daylight, we headed up past RAP, Spearfish and Belle Fourche toward 2WX. We were worried that a traffic jam, in an I-90 roadwork zone NW of RAP, would make us miss any storms that formed to our NNW; that turned out to be a moot concern.
We waited for a spell in 2WX, calling Bowman to reserve a room, the threw in the towel on any model-phantom storm formation nearby and headed N to our lodging. Along the way, we stopped on a hilltop just N of the Dakota divider for a photogenic Northern Plains sunset. OF Crowther’s supercell is the Montana storm silhouetted on the horizon, about 190 miles away. Ain’t it amazing to be able to see that far?
Even though the chase day didn’t amount to a whole lot convectively, we enjoyed each other’s company, had a few unusual and welcomed photo opportunities, and positioned ourselves to get a good night’s sleep before the diagonal crossing of North Dakota the following day. In Bowman, we even saw a long, bright, overhead flyover of the International Space Station before turning in.