Over the Belle Fourche River

December 23, 2012 by · 1 Comment
Filed under: Summary 

Elm Springs SD
15 Jun 12

SHORT: Another rewarding day considering low expectations. High-based but high-contrast and scenic storms over scenic High Plains of western SD.


The prior day, Matt Crowther and we had enjoyed a nonconvective hiking and driving adventure at Devils Tower, staying in Hulett, WY. Highly recommended: the airport/golf-course restaurant at Hulett, which is on a plateau overlooking the town and Devils Tower…great steaks and (according to Matt and Elke anyway) good beer and wine too. On this day, Elke and I did laundry in Belle Fourche while Matt dealt with some car maintenance, then we met at a high spot overlooking Belle Fourche Reservoir to watch for convective initiation.

Moisture was progged to be modest and analyzed to be downright meager. A series of MCSs over the southern High Plains during the previous few days had precluded ample return of rich boundary-layer moisture to these regions, though low-level storm-relative inflow and marginal shear were likely just to the E of a north-south trough near the SD-WY border. Our supercellular expectations duly tempered, we were content to see any sort of photogenic convection on this day, over such a beautiful landscape as the western SD plains.

While manning our convective sentry near the lake, deep towers began to develop over and immediately NE of an apparent source of lift located very near the northeast fringe of the Black Hills. The convergence zone associated with the trough appeared to shift E somewhat and intersect an area where heating of higher terrain was aiding in a sort of chimney effect for turrets tilting downshear. We zigzagged E and S past Nisland and Vale, stopping a couple times along the way to photograph the resulting young Cb that erupted into the deep blue Dakota sky–here with an abandoned shack and Bear Butte in the foreground to our SE, and here a couple minutes later with “just” the wide-open short-grass prairie. We headed S toward Bear Butte, stopping at an abandoned, antique pickup that Elke and I noticed ten years prior. I long had wanted to photograph that truck with an interesting sky in the background, and this was the welcomed result!

Navigating around Bear Butte, we took a winding, generally ENE course along SD-34 and across the Belle Fourche river, into a part of the state nearly devoid of paved road options and scant for river crossings of any roads. Our original storm attempt fizzled away as we drove beneath it near Volunteer, but a new storm developed rapidly in the upshear convective plume. That one, to our SW as seen from 9 NE Hereford, sported a much more robust updraft base and seemed to enjoy a nutritious blend of greater buoyancy and less entrainment (great taste, less filling?).

The storm was turning somewhat rightward with respect to the road, casting the increasingly precip-laden forward flank over the highway. Lots of other deep towers were erupting in all directions as well, including beneath the anvil of the main storm. This all forced a difficult intercept decision:
1. Continue ENE out of all the precip, wait potentially 1.5-2 hours for whatever was left of the storm (could be very messy!) to cross the Cheyenne River and get within good viewing range of a maze of mostly dirt roads on the other side, or
2. Cut S out of Enning toward Elm Springs on a dirt/gravel road whose maps advertised a crossing of the Belle Fourche River, figuring the road had to be at least passable if it connected two towns.

Being in South Dakota, we were wary of any option involving back roads, which quite often are in utterly wretched condition there. Nonetheless, we headed S, figuring the Elm Springs route would afford a decent one-pass opportunity to watch the storm approach us, then cross. It did.
Few other apparent chase vehicles appeared, so we had a reasonably peaceful viewing stops north of Elm Springs, including this pleasant westward view across golden wheat fields. As the storm drew closer, the arrangement of precip cascades in its forward-flank region offered some peculiar visuals.

Not desiring to be in the core, while on an unfamiliar dirt road, we continued S across the now-familiar Belle Fourche River to a spot just NW of Elm Springs, and let it cross to our N. At this time, the leading-edge updraft assumed a somewhat circular shape. A small, very weakly rotating convectively bubbly wall cloud formed, above a ragged scud tail related to the updraft’s inhalation of forward-flank outflow.

Within minutes, a separate area of outflow from an expanding rear-flank core demolished the whole regime. The entire storm then surged east, but not before offering a short yet spectacular CG show (photos looking NNW and then looking N), from what was left of the forward-flank area.

After the storm crossed into the road void of the Cheyenne River valley, it merged with other cells, grew upscale into a mess, and lost definition, leaving us in the unusual situation of “chase over” with plenty of daylight left. The next day would be a down day weatherwise anyway, with palatable supercell potential in better moisture slated for eastern SD day-3. As such, we cruised into Wall for lodging and dinner, anticipating the next day of photography and exploration in the uniquely beautiful Badlands National Park.