Altus Night Lightning

January 27, 2015 by · Comments Off
Filed under: Summary 

Altus OK
26 Apr 14

SHORT: Weak diurnal storms NW TX, brief supercell with lightning burst near LTS.

LONG:
Elke and I were off on this day, so we decided to go for a country drive to enjoy a fine Saturday afternoon and evening. That country drive involved heading SW from Norman, specifically to the warm sector ahead of the dryline near Vernon.

Because of a lack of richer moisture, prospects for anything tornadic didn’t look promising, unless a ribbon of higher mixing ratios could arrive just in time for that “magic window” of evening hours, when the boundary layer starts to decouple but the surface parcels still may be available to storm inflow. That scenario appears in wishes more than in reality in springtime regimes involving early-stage or incomplete moisture return, so we simply headed out in hopes of seeing some photogenic convection.

Wandering some backroads S of Vernon, we saw several nondescript cells bubble up and down in a SSW-NNE-oriented train. Most appeared rather mushy, befitting the lack of more intense CAPE, and didn’t exhibit any structure that compelled me to take more than a few test shots to make sure the camera was working. Still, we found a couple of remote spots away from highway traffic and enjoyed some time in the great Plains wind, as we enjoy every spring.

As the sun set, a newer round of storms was firing on the retreating dryline farther W–mainly SSW of CDS. We headed back into Vernon for some dinner at a greasy-spoon cafe, monitoring convective trends and plotting a course to observe the most intense cell after dark near LTS (an easy drive to the N) if it survived. By the time we got to LTS, the storm had been a marginal supercell but already was weakening, and another one mostly hidden to its NW was ramping up, moving mostly away from us, and starting to produce hail.

Regardless, we parked off a dark dirt road a couple miles SW of town and watched the slowly decaying original storm sail NNE to our SW, W and N, producing a few photogenic lightning flashes along the way. The second of them that I chose to keep (above in the header, and linked here), was the most fascinating. It appears to be a downward-directed attempt at a step leader that never contacted the ground, then got lit up as a secondary branch by a conduction connection (crawler style) somewhere deep in the cloud material above. The groundward-aimed scythe shape, as viewed laterally, makes me wonder how it would have appeared to a fortunate observer standing directly beneath–fortunate not to have been touched by the leader!

A few more flashes and the storm was done…and so were we. We headed home after a decidedly stress-free storm-observing trip having spent plenty of quality hours traveling together as a happily married couple.

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

Pray for Rain

January 22, 2015 by · Comments Off
Filed under: Summary 

Southwest OK
23 Apr 14

SHORT: Pleasant storm trek to southwest Oklahoma, intercepted three photogenic storms with varying supercell characteristics.

LONG:
After a rather long chase-free winter and early spring, Rich Thompson and I has a rare juxtaposition of mutual days off with the potential for supercell development along the dryline, and in one of our favorite storm-intercept areas: southwest Oklahoma beyond the Wichita Mountains. We headed out the familiar I-44/FSI/US-62 path well-trodden by generations of intrepid storm observers, hooking NW out of LTS to intercept an early, promising cell that peeled off the dryline and across the Texas border to our WNW.

Sure, we figured this day to have low tornado potential, given marginal low-level shear and the likelihood of high cloud bases. Nonetheless, there’s nothing like the excitement of anticipation in drawing closer to a developing storm on the first chase day of the year. It’s a sensation that cannot be experienced more than once per year–the promise not only of a storm awaiting through the low clouds and a decreasing number of miles down the road, and of what my lie beneath still unseen, but of an entire new storm season now kicking off in earnest.

Our storm obviously had a high base as seen headed west on OK-9 out of Mangum, and we stopped a couple miles E of Vinson to admire the view. The storm turned rightward and moved almost due E, Nof Mangum and toward the Granite area, but with its core of rain and severe hail right over OK-9 near Granite. This forced us to loop around through Mangum and NE past the badly drought-depleted Lake Altus, meeting what now was a very wet, messy, windy, outflow-dominant storm near Lone Wolf.

Even with a mesocyclone apparent in person and on radar, we didn’t desire continued engagement with this storm given: 1) its chaotic, heavy-precip structure, 2) its projected core path right over the best road ENE toward HBR, and 3) other storms developing in a better environment to the SW. We plunged back SSW toward LTS, going through a couple of heavy flanking-line cores to the Lone Wolf storm that reinforced our decision to bail.

Positioning near Martha, we turned W toward a newer, also high-based storm, encountering this impassioned plea in a church parking lot. Southwestern Oklahoma was (and still is) mired in a devastating long-term drought, the last of this intensity being during the Dust Bowl days of the 1930s. Supercells or other isolated thunderstorms really aren’t the solution to the drought for the farmers and ranchers there. While a supercell can drop a narrow swath of temporarily beneficial heavy rain, that only briefly helps those who happen to be in that swath–that is, as long as the storm doesn’t also offer damaging hail, severe winds, and/or a tornado. Within a week or less, the ground is dry again.

A nearby spot away from the busy highways offered us a casual and quiet place to watch this initially nondescript storm develop a strikingly beautiful cloud arrangement, including a nicely tiered and textured arcus accentuated by the light of the magic hour. Meanwhile, to our N, the storm unleashed some CG action over the Okie red-dirt countryside.

With the sunset hour at hand, we did a small jog to the E toward Friendship, catching the weakening storm base’s permeation by a few minutes of warm rays, before heading back down to a newly showery US-62 for the ride home. We thought that was it for the chase day, until one cell developed near the highway, became dominant, and cruised NE toward the Wichita Mountains.

Even though Rich had to be back by midnight for a shift, we had just enough time cushion to do a zigzag N out of Cache, past the Wichita Mountains Wildlife Refuge visitor center, and E a short distance to a vantage for watching the storm drift over the Wichitas. It turned out to be a severely tilted, marginal supercell, the main updraft region completely displaced in the vertical from any part of the anvil–even most of the backshear.

Serenaded by the wind and occasional crickets, we watched the beautifully striated storm emit a few brilliant lightning flashes that illuminated its stacked low-level structure–all beneath stars that speckled the cobalt sky of deepening twilight. All in all, this was not a bad way to start the aught-14 chase season–one that would turn out to offer very few tornadoes but an unprecedented variety of striking storm structure.

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Our PING trail for this day. [PING date is ending date in UTC. Any pings after 00Z were pasted onto this map as well.]

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.

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