Altus Night Lightning

January 27, 2015 by · Comments Off on Altus Night Lightning
Filed under: Summary 

Altus OK
26 Apr 14

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

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.

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

Pray for Rain

January 22, 2015 by · Comments Off on Pray for Rain
Filed under: Summary 

Southwest OK
23 Apr 14

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

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.

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