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.]

Junk Storms in Eastern Oklahoma

June 1, 2011 by · Comments Off on Junk Storms in Eastern Oklahoma
Filed under: Uncategorized 

Dewar to Wainwright OK
22 May 11

SHORT: Agonizingly slow-developing small cell Henryetta-Okemah followed by beefier but disorganized storms same area.

LONG: Once we got awake and organized, the Ozarks of SW MO and far NE OK seemed too far (and too unfriendly terrain-wise). Any nearer target for the day was rather nebulous, given the lack of a sharply defined boundary ahead of, and of strong lift along the Oklahoma segment of the dryline. However, we pulled out of Norman to the sight of towering Cu up and down a SW-NE aligned dryline located to our SSE through NE. Despite the SSW winds to its E, high SRH beckoned in eastern OK; and the dryline’s confluence (and convergence) zone became better evident with time during the afternoon in both clear-air mode reflectivity and VIS satellite imagery.

As the day before, following close behind (but not too close, since I was consuming pork rinds): the Dude, Three Chicks and a Dog chase team. And yes, given that we were headed to eastern OK, it was fitting that I was wearing a cartoonish “EVERYONE LOVES A REDNECK” shirt DF gave me as a birthday gift.

We waited at Ada only a short several minutes before towers erupted into a Cb to our NNE, S of I-40 and E of the dryline. Meanwhile a growing left-mover was charging NE from a splitting process down along the Red River, while the right-mover was dying. With nothing in between, we targeted the cell approaching Henryetta.

On composite reflectivity, the storm seemed to level off at under 50 dBZ for well over an hour, despite a healthy (if episodic) chimney of towers shooting forth into its anvil. With MLCAPE up to 6,000 J/kg in its presumptive inflow region, this didn’t resemble the thermonuclear detonation, as have other storm initiations on giant-CAPE days in the same area like 26 May 1997. Instead, when we got closer to the storm between Henryetta and Okemah, it sported pulses of small updrafts.

As we positioned along US-69, the W edge of the Bigfoot jungle beyond which chasing in OK is just not worthwhile, another storm erupted to the immediate SW of the original cell, to our W, and also near Henryetta. To our N, through haze and intermittent low clouds, we also could see the top 1/2 of the tornado-warned supercell SE of TUL, itself headed into horrendously rugged terrain N and NE of Fort Gibson Reservoir. We let the base of this new storm get closer; but it remained rather flat and featureless, with only shallow, transient and innocuous lowerings.

The atmosphere from the new Henryetta storm southwestward past Ada then erupted almost all at once, using up a raft of that giant CAPE air in massively multicellular form. We gave up on the chase day, shot a gap through the big mess, and headed home.

Only after arriving back did we learn that a few hours NE of our junky storms, in Joplin, a rain-wrapped EF5 tornado engulfed much of Joplin, causing the worst tornadic death toll in the modern weather-warning era. Clearly the environment was a good deal different from there to where we had been–much of it on the storm scale. Horrible fortune played a part too; the same tornado several miles N or S would have missed town, likely causing few if any casualties. In a year of rotten placement of several cities with respect to the tornadoes that would strike them, this was the worst in terms of human toll.