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.
LONG:
Background
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.
Round 1
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!
Round 2
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?
Round 3+
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.
Squall Line Way Up North
St. John ND
10 Jun 12
SHORT: Blew off chasing in trees in MN or driving from ND-KS in one shot, intending to hang out in ND ’til the pattern returned favorable parameters to Dakotas. While en route to Int’l Peace Garden, intercepted photogenic, low-topped squall line and attendant arcus cloud over very green fields near St. John ND.
LONG:
The cold front from the previous day’s action was slated to shift into more forested land of central and northern Minnesota, within which we didn’t wish to chase. Strong to severe storms also were possible farther south, along and ahead of the front, in mode viewing-friendly areas of Iowa, NW Missouri and Kansas, but under weaker deep-layer shear.
Laundry beckoned, and so did a few days of R&R in the heretofore superficially explored state of North Dakota before the next substantial atmospheric perturbation brought severe potential to the northern Great Plains. After finishing the wash and brunch in Grafton, we charted a net WNW course on the township-range zigzag of eastern and northern North Dakota, aiming to grab a couple bucketfuls of rich, black soil from the old Lake Agassiz bed for my vegetable garden back home (check), visit Icelandic State Park (uncheck), see the Pembina Gorge (check), visit the International Peace Garden (check), and spend a night or two in the so-called Turtle Mountains (check).
Somewhat retracing the route we took the evening before, we encountered a fantastic layer of asperatus (a.k.a. “warm-advection clouds”) between Grafton and Cavalier. That was followed immediately by a rather featureless, messy band of elevated thunderstorms that timed badly for visiting the state park. Instead, we headed up to Walhalla and toured the misty, scuddy and decidedly green Pembina River Gorge by car.
Ascending that small canyon, which drains an escarpment separating the Plains from the Red River of the North valley, leads the driver to the marvelously open, flat and attractive countryside characteristic of most of the state NE of the Missouri River. Folks here seem to inherit their ancestors’ fastidious tidiness ethic. In towns, this means well-kept houses, gardens and lawns. In rural areas, we saw a distinct absence of junk cars, rusty appliances, neglected fencing, or haphazard accumulations of dilapidated mechanical rubbish strewn across weedy lawns of occupied homes–in other words, a refreshign difference from thousands of points of blight that are prevalent in the southern Plains countryside. Landscapes here were familiar from the day before, but the setting was different–scuddy, light rain on the back side of the elevated storm band, with broken blue sky to the west, and the cool, moist freshness of wet earth behind a summertime cold front. This trip already was a splendid pleasure, and soon would become more so.
Proceeding westward across the borderlands, we finally broke into sunshine west of Langdon–but not for long! Onboard radar showed a thin, curving arc of cold-core thunderstorms developing to the W, over the turtle Mountains. A low-topped squall line was forming–something that experience told me could be quite photogenic in such otherwise clean air and sky. It was.
Approaching the squall line from the SE (as it moved quickly eastward), we marveled at how shallow and low-topped the convection was–typical for a cold-core low in a low-CAPE, relatively low-tropopause setting–but still rather uncommon in my southern-latitude experiences. In fact, just a few miles ahead of the arcus cloud, sunshine still illuminated the moist and richly verdant fields adjoining the east side of the Turtle Mountains. This clearly was not any of the 60,000-foot-deep walls of deep-convective severity I’m accustomed to observing in a North Texas April.
Our viewpoint was just SE of St. John, only four miles S of Canada, and in a fine position to view the oncoming shelf cloud. We were able to frame the sweeping arcus above the gentle curve of a rural dirt road that nicely split the greenery. After that, we cruised into St. John and let the storms move over us, enduring a decent barrage of small hail and subsevere gusts.
Heading into the hills, we quickly left behind the weakening squall line and visited the International Peace Garden (highly recommended, no passport needed!). The storms had run off the visitors, so we nearly had the place all to ourselves in rain-cooled air with sunny, late-afternoon light. Afterward, and with no one behind us in the customs line, I had a long, very friendly conversation with a customs officer and USAF vet at the re-entry station (the park is directly astride the border, its driveway halfway between U.S. and Canadian customs). He gave us a good recommendation for lodging options beside beautiful Lake Metigoshe–at which we reserved two nights for R&R before the next chase-worthy, northern-Plains shortwave.
Beauty of Outflow Dominance
Nebraska Panhandle Bow Echo and NE Colorado Dry Downburst
16 June 11
SHORT: Fun day. Began in Hot Springs SD. Observed/photographed spectacular outflow-cloud structures (shelves, bands, stripes) with raging bow echo/haboob from BFF to N of SNY. Dropped S for peculiar, photogenic dust storm and sustained damaging gusts beneath high-based N rim of eastern CO MCS.
LONG: Back onto our storm-observing trek after a couple of amazing days in the Black Hills, flow aloft and at least marginal low-level moisture were beginning to juxtapose favorably once again to our south. We targeted the nearby Nebraska Panhandle for the prospect of high-based storms rolling east out of the higher terrain of eastern Wyoming. Browsing the morning maps, I was confident in upslope flow into that orography, along with afternoon storm initiation…but would there be too much, too soon, before the richer moisture could arrive in the evening? This scenario would mean outflow dominance.
Still, a conditional triple-point play in south-central KS was much too far away; and the mountains ain’t going anywhere. Blow increasingly moist air into them for enough time during daytime heating, and storms will form. Our goal: be downshear and see what evolves. High dew-point depressions portend shelf clouds, dust and high wind from storms; and sometimes that can be beautiful too.
And so it was…
We drove to favorite overlook SW of Angora upon which we had perched a few days before, watching the top 4/5 of assorted towers build and glaciate over the unseen mountains of eastern WY. Finally, when the storms started to coalesce and move off, one of which looked like an embedded supercell on radar, we headed W to the N edge of BFF to watch them roll downhill right at us. By then, the supercell was hard to distinguish in the onrushing wall of a dark, ominous, and increasingly well-defined squall line.
Reflectivity animations confirmed that the northern segment — basically due W of us, was bowing out. It was time to go outflow surfin’! Stay ahead of these, and they can offer some absolutely stunning cloud structures, such as the following three-piece view from between BFF and Minatare:
Looking NW: I’ve never seen a combination of lightness, darkness and radiating cirriform streamers like this before!
Looking W: Right into the teeth of Jaws. This is what a bonafide bow echo looks like when it’s “a-comin’ ta gitcha”. Check out the peculiar translucent strands, reminiscent of Silly String, festooning the otherwise featureless midlevel cloud deck. It might seem hard to photograph the strong dynamic range between the ink-dark core and the otherworldly apron of light above and beyond the shelf cloud; but not this time. This is how it actually looked, with no HDR bracketing necessary! I just had to meter for the area smack in the middle.
Looking SW: A classic view of an onrushing convective windstorm on the High Plains, this time with the Wildcat Hills lining the southwestern horizon.
We stayed ahead of the snapping maw of this storm — barely at time, I must admit — all the way to Bridgeport and beyond — before bailing S to let the road-deprived Sandhills have their turn at it. We got one last nice view of the atmospheric earth-mover raging to our NW before turning equatorward. What a gorgeous display of outflow-driven stormscapes we had witnessed!
Now it was time to get out of the way and figure out what to do with several more hours of daylight. Some storms had fired in NE CO, likely to be just as outflow-dominant and perhaps quite high-based. From SNY, it wasn’t that far away, and the next two days looked like potential Colorado storm targets anyway. As such, went back through Sterling again (retracing a good deal of our chase path from BFF three days before).
Unlike then, the Centennial State sky greeted us with a giant field of decaying storm material — virga dropping from various patches of agitation beneath a widespread anvil shield that once contained actual updrafts. N of Otis, a wall of wind slammed us in an impressive dry downburst, tearing dense channels of dust from plowed fields, buffeting the vehicle laterally with shot after shot of very localized wind-force lasting a second or so apiece, and making me struggle with the wheels to maintain positioning on the road. Good thing I had new tires for this season…
After a late rainbow and dinner at a familiar restaurant in Yuma, we bunked down there for the night, satisfied that we made the most out of a very windy storm day.
The human element of storm observing always has some interesting twists and turns too. We had a few loud neighbors at our motel, getting drunk and cussing in Spanish, and after a spell, I thought I might have to go out there and shut them up by request or otherwise. Fortunately for everybody, the former worked. The ringleader turned out to be cut from the cloth of my old barrio associates from long ago: he was wearing a shirt that said, in Spanish, “Don’t f___ with the DALLAS COWBOYS”. All day, I already had on my trusty blue-star cap. After some conversation about America’s Team, they retreated to their rooms, an elevated storm blew by with an intermittent show of close CGs, then off to bed everybody went.