Steams and Storms in Yellowstone

July 14, 2014 by · Comments Off
Filed under: Summary 

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:

  1. The boundary layer was destabilizing again with at least adequate residual and advecting moisture;
  2. Anvils were streaming off still another round of storms–this one likely well back in Idaho but moving generally our direction;
  3. 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.

Our PING trail for this day.

7-11 Lightning

July 5, 2014 by · 2 Comments
Filed under: Summary 

Norman OK

SHORT: Highly electrified twilight storms near home.

LONG:
If one can define a “storm chase” as deliberately driving away from home in pursuit of the experience of storms, this was my shortest chase on record. I have several vantages pre-selected in the Norman area for viewing and photographing the sky under various situations–day, night, lightning, arcus, rainbow, mammatus, sunset, sunrise, east, west, north, south–views not available from my largely forested property. However, none are as close as the one I used on this day–a previously unused, ad-hoc perspective less than a linear mile away. I typically don’t post these short “chases”, but this is a worthy exception.

Seeing a large storm erupt on an outflow boundary to the SE, and flickers of lightning within, I didn’t know how long it would last, so a SE vantage several miles away wasn’t going to do. I exited my neighborhood and headed to a hilltop that–while not ideal due to a rather cluttered acreage in the foreground–offers the advantage of speed of access. It also would help as new storms developed to the SW–convection that would have been much more distant and less photogenic from even farther E.

First, the sky to the SE offered a rich, deeply textured and rapidly evolving panorama of convective, stratiform and electrical tones. To get a fuller idea, please see this Javascript time lapse of the full series of still photos of that storm. [You may need to tell your browser to enable Javascript if it doesn’t come up automatically.] What a wonder that was, and all in the soft blue ambiance of early twilight!

As that storm was weakening, I started packing my gear, when I noticed flashes in weaker convection to the SW and SSW (along the same boundary). The updrafts looked skinnier and not as intense, yet suddenly…BAM! A discharge brilliantly flung well away from its originating cloud area. Time for action! I hurriedly twisted around the tripod and camera, realigning, re-aiming, hoping and wishing for more. I started interval-shooting too, which caused me to miss a few of these spectacular “bolt-from-the-blue” discharges, but which also allowed for two more very brief time lapses. For once, I also managed to capture the most amazing stroke of the whole sequence.

Consider my photographic desires fulfilled. The cells kept blasting forked strokes far out through clear air, out of upper reaches of the convection, while also splendidly illuminating the cloud structures from within!

One of the most dazzling lightning strikes I’ve ever captured on film or digital media then burst forth from the opposite side, forking for many miles across clear air between cloud and some very unfortunate ground target. That left me exuberantly breathless, mouth agape, absolutely astounded that a “mere” summertime multicell could put on such a dazzling performance. Its thunder, though originating many miles away, reverberated through the air, felt within while echoing from laterally and behind. Finally, the storm had one more electrical javelin-throw in its arsenal before weakening.

Those two short time lapses I promised? The first is here, and the second is here, containing each of the strokes pictured above, but in larger format whose animation you can adjust.

The trip back home took all of two minutes. The “chase” yielded the only Image of the Week that I posted within less than an hour (the site goes by UTC time, hence the “12” date), and it’s not hard to understand why so little deliberation was needed.

Last Chance near Last Chance

March 11, 2014 by · Comments Off
Filed under: Summary 

Wiggins to Cope CO
23 Jun 13

SHORT: Remained ahead of northeast CO convection as it metamorphosed from early, fuzzy slop near Hoyt and Wiggins to a supercell-infused squall line between Woodrow and Cope with several photogenic and beautiful scenes.

LONG:
Final chase days of the season usually are known in advance to us, because we tend to take our Great Plains trips near the end of the traditional spring storm-observing season in a fixed time slot. As such, many last-chance chase days are known as such that morning, if not before. They can get sentimental. We focus and reflect on the possibilities with a renewed sense of wonder and anticipation, knowing this is the final opportunity for the season and probably the year (save the opportunistic fall chase that happens once every five years or so).

Northeastern Colorado was the target area, with the old outflow boundary from the previous day’s convection in WY and NEb having settled southward into eastern CO and weakened, leaving behind some upslope flow into the Front Range, reduced low-level moisture compared to the previous day in WY, and weaker (but still sufficient) shear for supercells. Cloud bases were likely to be high, with strong potential for outflow dominance and meager, conditional tornado risk.

Yet these reduced-moisture, upslope-flow days often yield scenic skyscapes festooned with interesting storm clouds of various types–especially if one is patient with often ragged, nebulous early convection and keeps apace until it organizes. Forecast storm motion toward the CO/KS border area also likely would take us toward I-70 and a one-day drive home the following day.

Our weather-dictated itinerary the previous several days had taken us from MT-ND-SD-WY-NEb, where we were starting the morning in Kimball, right by the CO border. It was as if a storm-intercept guide had been navigating us gradually homeward with amazing skies and fantastic experiences all along the journey. How fortunate! And here we were, ready to partake of one more afternoon of beautiful storms on the way home.

Proximity to the target area allowed plenty of time to eat brunch, analyze data, and watch the southwestern horizons. Early-afternoon towers erupting to our SW, in northern CO, were easy to see from IBM, so we cruised easily S to Ft. Morgan and saw the high, fuzzy bases even from there. Continuing SW through Wiggins toward Hoyt, we got a nice close-up view of the virga factories, appreciating the majesty of the High Plains even under soft storms, on scales large and small. Small? Oh yes. We enjoyed watching birds that Elke couldn’t identify hop through the stubbled cornfields of 2012, skittering along at a deliberate clip, pecking away at bugs, seeds, or other material unseen.

Next, we retraced the path back up to Ft. Morgan, then veered southward to get on proper road options that would allow us to stay ahead of whatever would evolve from the growing multicell complex to our W. While doing so, the convection slowly acquired visible, if still high, updraft bases, which gradually grew in areal extent and number along with CG flashes. I’ve seen this before. Usually, in these favorable deep-shear profiles, a supercell will develop unless the entire mass is blasted asunder in infancy by cold outflow. That wasn’t happening; the cores offered only feeble density currents, judging by the lack of proximal dust plumes.

Jaunting off the main highway between Brush and Woodrow, a couple miles down a dead-end dirt road, we found a good place right at the terminus where we could photograph wild sunflowers and a wild storm. Cores grew. Updrafts grew in front of the cores. Inflow strengthened. The whole raggedly beautiful storm pile got better-organized and backbuilt before our very eyes, ears and nostrils, as revealed during a stop just S of Woodrow.

East on US-36 4 miles out of Last Chance, and another mile N on a (barely) paved side road, led us to temporary solitude: us, a photogenic abandoned farmstead and the rampart of storms in the west. Whoa! What’s that back there to the NW behind the old house? You guessed it, brother–not just an old storage building, but a high-based wall cloud and mesocyclone.

Although short-lived, the line-embedded supercell provided some striking, picturesque scenery as it headed ENE, before getting disorganized in favor of other updrafts to our own W and SW. While watching that spectacle, a ranch mom and her kids drove up on an ATV to make sure we were OK; we chatted with them awhile before one of the little ones drove them all back to their house on the four-wheeler. Encroaching storms sent us eastward to the Anton area.

Even though the whole complex was becoming increasingly outflow-dominant in the fading daylight, a marvelous episode of deep twilight blues, slate to marine in hue, sandwiched layers of laminar cloud material to the SWto the Nto the SW again. What a show! At least transiently intense, somewhat supercellular updrafts kept forming along its leading edge, with assorted notches (some rather sparkly!) and other circulations of varying scales.

Admiring the scene, we also noticed that the base surfing outflow to our SW was becoming increasingly circular, quickly. Within less than 30 seconds, and about a mile away (closer than it appears in this wide-angle shot), a small but tightly rotating wall cloud formed from a pre-existing, seemingly benign lowering under that base (annotated version). Quickly, dust stopped then rose beneath. The circulation started to hook toward its NE–right at us. What had been light westerly (but mild) outflow winds backed and accelerated from the ESE. Time to bail out of there!

Although I doubted any substantial tornado could develop in this circumstance, I didn’t want to be the guinea pig to test that hypothesis. Even though we only had to go less than 1/4 mile to get back on US-36 and gun it eastward, we still were not comfortably relaxed–no thoughts of rocking in hammocks beneath Caribbean tiki huts while sipping dewy beverages. Instead, the rising pile of dust, under a small area of cloud-base rotation, with screaming inflow winds, nearly overtook us. I can’t say for certain if that circulation ever tightened into a full-fledged tornado, but if not, it came precariously close.

Just as fast as it formed, deeper outflow from the west crashed through the feature and tore it up, leaving behind a dispersive dust pall over the highway behind us as we gained a few miles of headway. With daylight fading fast and eyelids growing heavier, we watched the mess become more linear and turned S toward I-70, out of the way of all storms. A night at our favorite motel in ITR, lightning flickering off to the N and NE, closed out our 2014 storm-intercept season with a lullaby after the atmosphere’s final flourish.

Driving home the next day, we reflected and remembered. What a season it was…rewarding for us photographically, educationally and spiritually through the unfailingly transcendent experience of wonder and awe before storm-tossed Great Plains skies. The sting of major missed tornado events practically in our backyard was healed during over half an hour of observing from one spot a nearly stationary, violent, yet ultimately harmless tornado in open country of northern Kansas. We made some great memories amidst the solitude of the prairies from North Texas to central Montana. With heavy hearts, we also thought of old friends killed just over three weeks prior by the vaporous forms we seek, on a day when we didn’t head out. Here’s to a safer and much less destructive, yet more photogenic and inspiring, 2014 storm season to come.

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Our PING trail for this day. [PING date is ending date in UTC.]

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