Steams and Storms in Yellowstone
Yellowstone National Park, WY
17 Sep 13
SHORT: Observed multiple rounds of storms in this park, the last of which was deliberately intercepted at Old Faithful.
Elke and I had witnessed thunderstorms on several days of a 2.5-week trip across the north-central Rockies region, mostly in passing with no deliberate intercept attempt. However, this day would offer three storm-experience opportunities, the last being rather purposeful.
For the week-long Yellowstone part of our excursion, we were staying in two places — a roadside motel between Cody WY and the east entrance, and a motel in Island Park ID, a short and scenic drive from the west gate. This day was the scheduled move between, meaning a full transect of the park, a tour of geothermals around Yellowstone Lake, and our first visit to the geyser basins on the W side, all amidst known potential for strong to severe storms in the area.
Low-level moisture was very abundant in the area, thanks somewhat to lingering summer monsoonal trajectories from the Southwest, but mostly to a long-traveled Gulf of Mexico fetch that contributed to the devastating Colorado Front Range floods a few days earlier. A middle-upper-level shortwave trough was approaching the area from the Pacific NW, preceded by a seasonally strong low-level cold front. [We would experience snow and sleet behind that front the next day, PINGing the season’s first winter precip from Old Faithful!] Best of all, deep-layer lift in the warm sector, ahead of the front, would juxtapose with that moisture-laden boundary layer. Deep shear even would support supercells by afternoon, if the storm mode would cooperate and not go linear too quickly; however, I certainly wasn’t counting on that given the strong low-middle-level lift and weak cap expected by then, on such high terrain.
Given those meteorological conditions, I wasn’t surprised to wake up to a shower, and to see radar loops showing a band of thunderstorms already moving into the western parts of the park around sunrise. We were headed to the shores of Yellowstone Lake, which would offer an unimpeded view of this early convection if we could get there in time.
By the time we hair-pinned our way over the Absaroka Range and crested the last hill before the lake, the morning storms already were approaching. We observed and photographed them looking SW beyond the skeleton forest and across the lake, in the unusual circumstance (for us) of eastern-sky sunlight. At our altitude, we nearly were looking “down” at the shelf cloud and cloud base in the distance, too. That was about the best “structure” this early-day convection could muster, and after a brief view from the lake shore itself, we core-punched it (with no adverse effect) to get to some photo locations and intended lunch at a restaurant near Grant Village (SW shore). That was a fun little adventure, with more to come!
Despite shooting no storm photos during this stage (the storms were messy and we were in the woods), it was very enjoyable anyway. By midday, enough surface heating and warm advection behind the morning convection had occurred to destabilize the high-elevation air mass again. This time, a small cluster of surface-based storms formed to our SW and W, near the ID border, and cruised NE toward the West Thumb area of Yellowstone Lake. We had barely enough cellular coverage to track and time them relative to our position on radar.
Planning to flex the time windows of our landscape photography and meal, based on weather and light conditions, paid off. Obviously, shooting hot-water holes from a wide-open boardwalk in hard rain and lightning is not advised. We decided therefore to eat first. As we did, the storms hit with remarkably heavy rain, subsevere but still robust gusts, and several very close CG strikes.
During all that, we just sat back and enjoyed a leisurely lunch next to the picture windows that overlooked the lake.
Sometimes one simply should enjoy the experience and not bother with the camera; this was one such time. How often would we ever get to eat a delicious (if somewhat overpriced) meal safely under cover from a heavy downpour, while gazing through pine forest at Yellowstone Lake?
After that round, skies cleared, the storms quickly shoved off past the Absarokas, and we headed out for our geothermal photo shoots, intending to visit Old Faithful and one or two other geyser areas on the way to dinner in West Yellowstone, MT, before retiring to Island Park for the night. I knew the cold front still was back in Idaho–but cell-phone data coverage was practically nil in the West Thumb geyser basin and westward nearly to Old Faithful.
Adept storm observing often involves simply reading the clouds and wind–this was true afield before the technological crutch of cellular telephony. Such skills still came in handy. The atmosphere itself spoke in a language of fluidity: small cumulus clouds moving from S to N, increasing in numbers and depth over time, along with western cirrostratus darkening near the horizon and streaming E. Here’s what the sky was saying:
- The boundary layer was destabilizing again with at least adequate residual and advecting moisture;
- Anvils were streaming off still another round of storms–this one likely well back in Idaho but moving generally our direction;
- Veering of winds with height and decent upper-level cloud movement signaled good vertical shear for organized storms.
As it turns out, some of the Idaho convection beyond the western park mountains included a supercell responsible for weak tornadoes NW of Island Park, near Dubois! While it would have been great to see my first Idaho tornado, that would have been the ultimate “needle in a haystack”, necessitating blowing off most of a day of Yellowstone exploration for a tiny probability I’d be in the right place, right time. Instead, I’m quite pleased with what we did see–a dramatic squall line and its related dark core and shelf passing very close to Old Faithful. We headed up to the famous geyser, hoping the next eruption would time well with some dark-cloud action.
How fitting it was that my first visit to Old Faithful came with a line of storms! Before the main shelf and core arrived, we got to witness an eruption in front of the darkening low- and middle-level cloud cover. The dark sky made a fantastic background for the geyser, even as the wet eruption concluded. Old Faithful still offered a fine foreground for the storm after the wet eruption was done and only steam vented forth. The shelf cloud then scenically surged our way, heralding the onset of core conditions and a cooler vacation hereafter.
That was so much fun, we waited for the next eruption, instead of heading to West Yellowstone for dinner straightaway. The back side of the storm complex still festooned the area with scuddy low clouds and general light rain, while occasional, elevated showers and weak thunderstorms developed atop the outflow pool. The rain-cooled air, which helped to highlight the steam clouds from other geysers in the area, added a surreal aura to the scene. The loose resemblance to an inflow jet and tornadic condensation was not lost on me.
Cruising up the western park road toward the exit, we caught a fantastic view across the Lower Geyser Basin with an elevated storm as the background. It produced only faint lightning, but offered yet another grand background to finish a day of both atmospheric and geologic wonderment. Fittingly, more elevated storms serenaded us with heavy rain and thunder as we ate pizza in West Yellowstone, before we retired for the night to a cool, soggy Island Park, ID.