Steams and Storms in Yellowstone

July 14, 2014 by · Comments Off on Steams and Storms in Yellowstone
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.


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.

Buried Tornadoes by the Border

February 28, 2014 by · 1 Comment
Filed under: Summary 

Chugwater WY to Kimball NE
22 Jun 13

SHORT: Intercepted 2 supercells in SE WY, first photogenic, second became dark and nasty HP with about two tornadoes buried inside and barely/intermittently visible. Lightning and photogenic outflow formations with tail end of resulting MCS in NEb Panhandle.

Having made a full-circle back to Chadron from five days before, we did a little late-morning photography of abandoned antique vehicles that we had seen previously, then bid farewell to our favorite north-central High Plains town to head SW. We targeted as promising of an upslope-flow supercell scenario in southeastern WY as you’ll ever see, realistically. The previous day’s boundary was shunted southward toward the Cheyenne ridge, flow behind it veering throughout the day to both advect unusually rich low-level moisture upslope (beneath favorably strong midlevel winds) and yield a big hodograph. That moist air rising up the Laramies would do the heavy lifting, with help from hours of sunshine. Since we actually weren’t far away and were leaving before noon, I was as confident in seeing a tornadic storm on this day as any the entire June trip. Slap those hands together, fill the tank, hit the road, and get ready to rumble under some spinning sky.

Supercells rolling off the Laramie Mountains under similar flow patterns and even less moisture have produced delicious tornadoes on several occasions in the last 15 years. For some reason, we (and I, before marrying Elke) had been late to the party for most of them, either missing the tubes or barely catching their end stages. The 2010 Chugwater storm was, of course, a wonderful exception. Even early initiation wouldn’t be a problem, given the long N-S roads of eastern WY and the good visibility away from the E slopes of the escarpment between Hawk Springs and Chugwater.

Over the hills and into Wyoming we went, fueling in Lusk under the midday sun as anvils began streaming off the northern limb of the Laramies. This was early initiation indeed…for which (for once) we were ready! The most vigorous cell, near Dwyer, appeared to be turning right and organizing into a supercell fairly quickly. Fortunately, it was aiming right down US-26 toward the Lingle area, where getting ahead of it would be easy. No wondering what was over the horizon, no driving 150 miles after an early-forming Wyoming storm already in progress! When we got just S of Lingle, there it was, in youthful supercellular splendor, to our W.

The supercell traveled ESE as another developed to its SW, with rain from the newer storm cascading into the established supercell‘s upshear region. After briefly encountering fellow storm observers Vince Miller and Matt Crowther, we moved a few miles S, stopping briefly to watch a beautiful phase of the otherwise shrinking and rising cloud-base configuration, characterized by a clear slot with tightening rotation. Nothing came of that; the occlusion downdraft cut too tightly into the rotation area and dry entrainment eroded what was left. The older cell then slowly weakened at the expense of the rapidly strengthening upshear storm, and we headed S toward Veteran to get in front of the latter.

What we found there was an entirely new animal–one that would turn into a menacing, growling, teeth-baring, attacking beast in short order. Looking SW at the reasonably large updraft area, ragged, slowly rotating shelf/wall cloud hybrid and dense core, it was easy to predict that this beautiful mess of a storm would become an HP in short order. Since the entire storm was moving ESE, this was an unsustainable viewing position; the forward-flank core and its hail would impose its will on us if we stayed put much longer.

A quick zigzag E and S out of the Veteran/Yoder area took us onto US-85 NE of Hawk Springs and NNE of LaGrange. We had to bolt S ahead of the strengthening mesocyclone to our SW in order to take the east option toward WY-151/NEb-88. First, however, we had a few minutes to stop, observe and admire a very rapidly intensifying circulation–a photogenic and menacing wall cloud that quickly evolved into wide, rapidly rotating, nearly ground-scraping bowl, a mesocyclone that clearly meant serious business. A small funnel briefly whizzed around the left (SE) side of the bowl, but with no clearly discernible debris beneath. The entire spinning mass of gas still was moving ESE and we were NE of it. No time to tarry…we had to go!

We skirted the E edge of the orbiting precip curtains from N-S as the mesocyclone quickly wrapped in rain and the storm took on a mean, nasty HP form. I’m used to tangling with those in north TX, but not on the more road-sparse plains of the WY-NEb border. Fortunately the east-151/88 option was conveniently located to offer a chance to get safely ahead of the whirling dervish for awhile, albeit in the eventual path. A brief glance at radar indicated a rapidly tightening and potentially tornadic mesocyclone to our NW as we approached the border. I stopped there to observe and thought I might have seen the tornado (see photos in table below), one about which I was more certain that night, after viewing the photos via camera display and talking with the NWS office. Given its S of E movement, we couldn’t stay too long.

After charging E across the border, after a mesocyclonic cycle, and while I still was driving to gain some distance, Elke took a look at the radar display and saw this rather alarming SRM signature a few miles to our NW. There was obviously another tornado somewhere in that dark precip mass–and likely a significant, potentially violent vortex to boot! It also was moving ESE, meaning we would have to stair-step along the W-E highway in multiple stops to stay safely ahead of it, and of the wrapping precip.

Needless to say, I slowed down really quickly and turned into a northward-directed side road to stare hard into the rotating cylinder of precip. At times, during the second of two different stops along NEb-88, I could make out the tornado ‘s condensation funnel–briefly, barely but confidently. We stopped again after turning S on NE-71 past Harrisburg.

What follows is a chronological table of links to a selection of photos taken at the stops, looking NW at first, then WNW. The photos show the region as it looked with eyeballs (“PHOTO”), heavily enhanced (“ENHCD”) and in a few cases, enhanced and annotated (“ANNOT”) to bring out the tornado where possible, and to illustrate the motion. Curved arrows on some ANNOT images show the area of very intense rotation. All of these were processed within a few weeks after returning and provided to the CYS WFO for their evaluation. [I have them prelim track and time estimates the same night via phone call using adjusted camera times (camera was 4 minutes fast).]

[Please scroll down to see the tornado-photo table and the rest of the post. I don’t know how to fix this gap.]

Sequence Number & Viewing Location

Normal and Edited Photos

4. 3 E Stegall S Rd on NE-88 PHOTO NO ENHCD NO ANNOT
5. 3 E Stegall S Rd on NE-88 PHOTO ENHCD ANNOT
6. 3 E Stegall S Rd on NE-88 PHOTO ENHCD ANNOT
7. 3 E Stegall S Rd on NE-88 PHOTO ENHCD ANNOT
8. 3 E Stegall S Rd on NE-88 PHOTO ENHCD ANNOT
9. 3 E Stegall S Rd on NE-88 PHOTO ENHCD ANNOT
10. 4 NE Harrisburg on NE-71 PHOTO ENHCD ANNOT

Because the tornado on the Wyoming side of the border (images 1-3) appeared to shrink and get deeply occluded into the precip, and because NWS CYS surveyed a distinct tornado track on the Nebraska side, I now very strongly believe (>95% certainty) that the Wyoming and Nebraska tornadoes were separate. On the Nebraska side–yes, there also was another dark, columnar area to the left (SW or WSW) of the tornado cyclone in a few images (mainly 4-5), but I could not tell what it was. The rotation of precip around the tornado in each photo was furious and obvious. Even when I couldn’t see the tornado at all (which was most of the time), there was no doubt of its presence.

Due to lack of visual continuity, I also can not state definitively if the Nebraska tornado was continuous between stops, or two separate events. NWS surveys indicated one path in Nebraska, so I’ll count this as a single, second tornado for now, given no firm evidence to the contrary. The tornado only hit a few things, earning an EF1 rating due to sparse/weak damage indicators. However, its WSR-88D radar signature is consistent with many strong to violent (EF3-4) events, based on a study underway by Bryan Smith and others at SPC. We’ll never know its true strength.

The tornado moved almost directly toward my position in image 9, but dissipated before it got to NE-71. By that time, we had bailed S, out of the way, and found a hilltop S of the 71/88 intersection. There, we tried to view the deeply occluded, embedded meso as it got thrust back out of the rear side of the precip area (enhanced. There may have been a weak tornadic (or nearly tornadic) circulation still going at that point (enhanced), as visible cloud-base rotation still was reasonably strong. I can’t say with complete certainty. By this time, a big gust front and shelf cloud had surged well ahead of the mesocyclone. The supercell was evolving into a linear structure with more storms erupting to the SW–we had an MCS and QLCS on our hands.

Plenty of daylight remained, so…time to go tail-chasing! We proceeded S to and past Kimball in search of a vantage, and found one 3 SSW of town on County road 28, right along the N side of Kimball airport (IBM). This was a treat! Even though the complex was decidedly outflow-dominant at this stage, its arcus underside and photogenic lightning were just plain fun to observe. The core passing to our N fired a good volume of electrical artillery from the same general area (including one whose most visible segment was “questionable”). One bright outlier, an outflow-influenced channel and a few other strikes followed as the core moved E. Meanwhile, the arcus’ underbelly passed overhead and to the S with fantastic sharpness to its turbulent texturing. What a crazy, interesting sky!

Ravenously hungry by now, and chilling uncomfortably from all the outflow, we snapped the shutters at a few more strikes from the last passing core, then headed into town for dinner. Amidst that huge and expansive puddle of outflow, we didn’t imagine that an updraft would blossom to the E that was surface-based, and produce a brief tornado (seen by a few observers still afield) before being undercut. That’s how it goes sometimes. While somewhat disappointed, we could live with it. We had seen some serious tornadic action already, and the hot pizza tasted mighty good going down. Here was one final look at the back side of the complex from the pizza-parlor’s parking lot, as the storms retreated into the suppertime sky.

After checking into the motel in Kimball, I got the tornado time/track info to the CYS WFO to the best extent possible, then reflected back upon another long but very rewarding chase day–one fruitful both photographically and in terms of both tornadic and nontornadic storm experiences. Forecast guidance also indicated that we had one more day of decent storm potential in CO before we had to head home. Our time in Montana was growing ever farther away in the rear-view.

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

Bighorns Boomers

January 2, 2014 by · Comments Off on Bighorns Boomers
Filed under: Summary 

Bighorn Mountains, WY
17 Jun 13

SHORT: Two rounds of morning to midday storms in beautiful Bighorn Mtns., rain from weak/dying convection WY/MT border.


Today was intended to be a leisurely trek from Buffalo WY to MT, but not by the Interstate. Instead we had all day, thanks to a lack of substantial severe-storm potential until day-2 in central MT. As such, we aimed for a reunion with the Cloud Peak Skyway and its resplendent vistas of the Bighorn Mountains, followed by a trip across the Bighorn Basin to a stop somewhere in south-central MT for the night. We weren’t planning on a storm chase and didn’t have one, per se.

Yet storms found us–and in one of the most scenic of places. A line of elevated thunderstorms rolled through the mountains in mid-late morning. This unusually encountered but most welcomed situation offered forenoon storm-light, and very interesting backgrounds for wildflower-landscape photography that ranged from eerily brooding closeups to deeply textured, pastoral meadow scenes one might better expect in the Austrian Alps. Given Elke’s heritage from the latter area, is it any wonder that she so wondrously appreciates the June wildflower show in the Bighorns?

Adding to our gallery from 2007, we also focused up-close on some gorgeous floral displays, whether from just the ubiquitous lupines, lupines with arrowleaf balsamroot, smoke towers–towers of prairie smoke flowers that is, Nelson’s larkspur (a highly toxic plant belying its beauty), mountain goldenbanner, a variety of false dandelion, or the common white locoweed that is the bane of western stockmen. We even saw a double puff of smoke!

Round one of storms passed quickly and harmlessly NE of the Cloud peak area by midday, however it left behind two prime ingredients for further convective development in a weakly capped, high-country lift regime: an outflow boundary and moisture–each of which were cooked in sunshine at ten thousand feet. Duly primed, additional deep convection began towering upward throughout the central and southern Bighorns, including overhead. Safety considerations (don’t want the first lightning strike to zap one’s noggin) and lunchtime hunger prompted us to evacuate the high country and head toward the basin, whereupon we took one final look back at a now storm-blanketed range.

Late lunch in Worland (which was pretty good) preceded a trek NNW toward Montana, through Greybull and Lovell WY. This part of the basin is desolate, with a great deal of bare, rocky ground and salt deposits. That’s related to the very dry climate, a result of being surrounded by mountain ranges with only a small gap in the north. Even that small gap sometimes lets low-level moisture creep in; so the vegetation got a little greener as we cruised out of Lovell toward the MT border. An expansive area of mostly orphaned anvil wafted overhead from some earlier storms in the Absaroka Mountains to our W, dropping a light, gentle rain on us as we crossed the border. What a peculiar novelty this was!

Rain in such a dessicated area often cools the air a lot evaporatively and leads to a rich, earthy aroma, and this was no exception. We welcomed both as Montana welcomed us. We enjoyed the views of the Bighorn River from the highway, called in motel reservations in Roundup for the night, bought a road atlas at the Billings Barnes and Noble outlet, got a late dinner in Roundup, and settled in for the night…anticipating our first central MT chase day ahead. This northern Plains trek already had been richly rewarding, and the following day would pile on that reward with a good dose of adventure!

Our PING trail for this day.

Next Page »