At Long Last: Birthday Tornadoes
Hickory and Ada OK
21 May 11
Prologue:
This was my birthday. I never have seen a tornado on this date before this year, despite the seemingly ideal time of year for them.
Hold on! Tornado climatology isn’t always how it may seem. For strange cosmic reasons that shall remain a cryptic mystery, that date (green in the graph below) also is an inexplicable and pronounced low-day for tornadoes in the U.S. during this time of year, as shown by Chuck Doswell in one of his research papers published in the Electronic Journal of Severe Storms Meteorology.
Click to open an enlarged version:
The Intercept:
Elke and I headed S towards the northern rim of vigorous return-flow moisture near the Red River, followed by a unique chase team consisting of David Fogel, his cousins Samara and Ellie, and Ellie’s friend Ella, and of course DF’s equine-sized Leonberger dog, Porthos. [Note: This meant I was chasing with Elke, Ella and Ellie…good times!] Ellie and Ella were first-time chasers this day, giving me hope for some “rookie luck” to overcome my “birthday curse”.
Our target area was southern OK an north TX just E of the dryline, and we settled for the middle: The Red River, heading to GVT to fuel up and await nearby development near the northern nose of the most robust return-flow moisture. On the way down, messy supercells were evident in central TX, well S and Sw of the Metroplex and out of the target area; while a discrete storm rapidly intensified just SW of FTW. A convergence zone was evident in reflectivity imagery extending N from the FTW storm past ADM. This was our hot zone for hot action.
Not wanting to intercept a storm through the Metroplex if we could help it, we held firm at GVT awaiting closer development. That move paid off; as the FTW storm quickly (and rather inexplicably, given the strong buoyancy) perished.
After fueling and getting some technical difficulties fixed with DF’s onboard electronics, we waited a few miles N of town near I-35, admiring wildflowers and convective towers–yes, newly developed moist updrafts to our near WSW and more distant N. The northern towers, even through haze rendered by smoke from Yucatan crop-burning, looked healthier and began glaciating, as viewed across the verdant North Texas savanna. We had a storm to target, brother.
As we pulled onto the I-35 slab and headed N, strong reflectivity echoes started to appear NW of ADM. Those developed quickly into a strong echo, already resembling a supercell by the time we exited the slab and headed E on OK-53. Intense towers rolled up into the back side of the storm with fantastic buoyant force, as seen looking NE from W of Gene Autry.
Zigzagging E and N toward Sulphur, we met the first hilltop base view just in time to view a funnel suspended from an older, occluded mesocyclone to our NW (and W of town). By the time I could pull over safely, the rotation already weakened, the funnel more ragged and not as low, the clear slot cutting well around the cloud-base mesocyclone area.
Focus shifted to a newer area of cloud-base rotation to the E. The storm already was tornado-warned and had been for some time. That appeared justified. This supercell was moving into a very moist, low-LCL air mass with big (and growing) 0-1 km hodographs. This already was the most promising storm I had seen on a birthday, despite some unquestionable jackassery that ensued while viewing the newer mesocyclone area. None of the scuddy, rotating lowerings to our NNE (just E of Sulphur) could tighten up much, and the storm was getting away.
We needed to reposition, despite the lack of great vantages in that hilly and intermittently forested part of the state. Haze clearly was a problem too, and I knew we needed to be close to get better contrast. Before that area of storm-scale rotation could cycle back up, we headed through town. Our bright-eyed, twentysomething supercellular newbies from New Jersey, Ellie and Ella, got serenaded by the stereophonic wail of the Sulphur sirens, offering them an ominously palpable reminder of the menacing side of springtime in Oklahoma.
About halfway E on OK-7 to OK-1, the organization improved, all right. Obligingly, the storm that had been behaving itself during our relocation grew a very broad, extensive updraft base–all of which was rotating, and rather rapidly. Within the tumultuous gyre, every lowering was spinning in its own right, the whole system a seething, cloud-base cauldron of eddies and whirls that defied ready classification. We stopped 3 SSW of Hickory (and 1 W of the OK-1 intersection) to watch its merry-go-round of distinct funnels, shallow and bowl-shaped lowerings, and at least one brief tornado.
Some vortices were more than two miles apart, others adjacent. Where is the cutoff between a broad, multiple-vortex, weakly tornadic circulation, and a multiple-funnel (or multiple-tornado) area of storm-scale rotation? This thoroughly fascinating process unfolding to our NW through N blurred the lines between any such distinctions on the spectrum of atmospheric vortices. Sometimes, it’s just not as simple as categorically declaring tornado or not!
Two of the longer-lasting, lowest-extending condensation funnels (middle and left here, looking NW) initially developed apart at 1924 CDT, within the same mesocyclone. The eastern (right) funnel retrograded almost magnetically toward the western one, intertwining with it as in a seductive love dance. The combined condensation vortex then became more laminar, less scuddy, more wavy, and produced a brief, faint puff of dust beneath (deep crop-n-zoom/enhancement), in an area of very wet ground.
By 1926, the brief tornado was gone, the area of cloud-base rotation (at left in this shot) that had hosted the small, blended tornado vortex weakened. Did you notice anything to the slightly more distant right (NNW) in the last photo? Lo and behold, another area of rotation took shape to its NNE, itself offering a ragged, conical funnel that extended more than halfway down by 1927 CDT. If this was a tornado (couldn’t determine via enhancement or independent eyewitnesses), it was separate from the other, a circulation within a circulation within a circulation. These were far from the only funnels in the storm-scale gyre in just a 10-minute span. What a gloriously complicated mess!
The broader mesocyclone soon began tightening, and we needed to get E and N again to close in for more unambiguous tornado potential. In the process, we crossed a spot of infamy–the very railroad crossing where an agonizingly slow-moving train halted John Hart and I after we saw the distant Hickory tornado of 11 May 1992. That train 19 years ago seemed to go on forever, as the supercell got away, wrapped rain around its SW hook, and produced a multivortex F4 tornado just out of sight. Today, the tracks were clear and such agony didn’t befall us. The same road we couldn’t take way back then was open for business–right here, right now.
We turned NNE on OK-1 and drove almost under the rim of a (by now) very strongly rotating and more classical mesocyclone, stopping at a spot 1.5 SE Hickory when a broad cone funnel appeared about a mile to our NE. At 1934 CDT, a brief filament of whirling condensation rocketed up from the ground beneath the cone as I was exiting the vehicle, and before I could shoot…tornado! The condensation cone soon drew lower. Sinuous, partly translucent vortex filaments materialized beneath and coiled about one another, vaporous marionettes twirled by their tornadic puppet master. By 1927, the cone retreated to a smooth cloud-base bowl, and no vortices or debris could be seen beneath.
The mesocyclone began retreating NE, so we had to zigzag E and N to maintain view as it reorganized, retreated NNE somewhat, cut a deep clear slot, and intensified again. Heading E on unmarked road “E1700” 5 E of Hickory (a variably surfaced path of gravel, dirt and crumbling, antique pavement), we were very fortunate to find another high, relatively unobstructed vantage to our NNW and N.
Just in time, too…the mesocyclone cut a deep clear slot and began twirling funnels beneath with fervor (deeply enhanced crop). For a brief interlude, the spinning cloud mass dipped its southwestern margins into golden beams of sunshine, fluidly swirling together the concepts of atmospheric violence and beauty.
The circulation seemed to plant itself on the earth, chunks of scud forming right down to the ground, ripping across the surface at tornadic speeds, interspersed with intermittent but unmistakable suction vortices–one after another, none lasting more than a few seconds, but collectively, too many to count. This was a very low, humid, multiple-vortex carousel. Sometimes two vortices could be seen interacting while scud and/or suction spots whizzed through other areas of the magnificent maelstrom.
[Some described this tornadic stage as a “wedge”, but the condensation was too ragged, sparse and ephemeral to call it that. Still, if viewed with any blockage by trees or terrain, I can see how such a mistaken description could be made.]
The last evidence of a tornado was at 1953; thereafter the cloud base rotated much more weakly and rose in height. By now, we knew of the larger, newer and stronger supercell W of Ada, but the clearest path to it up US-377 still was blocked by our weakening (yet still potentially hail-bearing) storm.
After letting that supercell pass across the highway, we had a smooth trip to Ada, barely in time to see a conical lowering below the horizon (turned out to be the end stage of its last tornado at 2035 CDT) while still driving. By the time we found a place to stop, a small and ragged funnel remained. No matter, we could marvel at the spectacular storm structure spreading across the western sky. As this storm moved NW of Ada and began weakening, assorted precip shafts cascaded from the cloud base near low-hanging scud chunks, likely yielding any remaining “funnel” or “tornado” reports.
The short but happy drive back to Norman led to a delicious dinner, steak and shrimp for the menfolk, whatever the ladies wanted, kibbles for Porthos out in their vehicle, all in a festive celebration of a fantastic storm-observing day (and for me, the clinching win on the restaurant TVs that sent the Mavericks to the NBA finals). Birthday tornadoes that didn’t hurt anybody, great storm structure, Mavs clinch a playoff series…a great, great day indeed!
Atmospheric Underproductivity
NW OK and SW to Central KS
SHORT: Assorted convective towers over NW OK and central KS, mushy storms in SW KS, twilight macroburst in northern OK.
LONG:
One year to the day after a chase that was most memorable for all the right and wrong reasons, Ryan Jewell and I left Norman for the PTT area at about noon. We hoped to follow a dryline supercell across a narrow warm sector and then be there for its mature interaction with a pronounced warm front, and the mesocyclonic bliss such processes often entail. Alas, the atmosphere had other plans.
On the way up, early initiation (before 18Z!) yielded a mess of multicellular and occasionally supercellular storms in SW OK, the anvils of which we could see. We chose not to be distracted by those “sucker storms”, and instead forge NWward with steadfast resolve for our target area, where both low-level hodographs and deep-layer shear would be stronger.
Along the way, near Seiling, several deep towers erupted in the free warm sector, seemingly along nothing more robust than faint differential-heating patches. These would glaciate for 10-30 minutes, then dissipate, leaving behind residual anvil shadows and a few souvenir raindrops. The appearance of such midday convection, well-removed from either the dryline and the warm front, dichotomously encouraged us (no problem getting storms today!) and troubled us (too many storms today?).
As we headed N through P28, convection began erupting in a band up and down the dryline from NW-SSW, boosting hope for a targetable storm, since we still were well out of reach for the activity up near I-70. One storm crossing the KS-OK border quickly acquired flying-eagle structure in reflectivity and standout VIL, while darkening the skies to our SW. Although the low-level SRH wasn’t too favorable in the immediate area, thanks to some earlier veering of surface winds ahead of the dryline, the flow was starting to back a little again. We were excited that this could be our target storm, moving NNE then NE into a progressively better environment with time. Too bad several other storms formed in its immediate vicinity, messing up the structure before it got to us.
The most spectacular event of the whole trip then happened in a flash. As we waited just off the NE edge of PTT, a CG from one of the leading cells struck a sheet-metal building across the road from us, instant FLASH-BANG, its white-hot column dispersing into a vertical necklace of brilliantly glowing, golden-orange plasma beads that blew northward in the wind for a second or two before dissipating. What a pyrotechnic display!
Our target storm became entangled in the mess of surrounding convection and lost its structure before reaching PTT; so we targeted a tail-end cell and headed W several miles out of PTT. By the time we met the “anchor” storm, it was but a small, smooth updraft base with a short tail cloud. By the time we found a stopping place for me to take a photo, the updraft cloud column shriveled to a pathetically flimsy chimney, soon to vanish altogether.
Surely this couldn’t be our fate for a day of such promise?
We scrambled NE toward Lyons to intercept a small but intense storm that materialized from the southern portion of the same precip area N of PTT, but it too turned to mush by the time we got there. All that was left: a strand of towers that had no chance to mature before crossing the warm front. Game over.
Here we were just S of Lyons, on the warm front, breathing in some of the most deliciously refreshing, richly moist air a human or storm could ingest, all for naught.
On the return drive from HUT-ICT-OUN, we smacked into an intense gust front just S of the OK/KS border, then stayed in near-severe winds for at least 25 miles across a swath of Kay and Noble Counties. This was an impressive macroburst, one of the most sustained I’ve encountered, blasting northwestward from a SSW-NNE band of high-based showers. Overhead and to the S we could see a patchwork of virga and loose mammatus in the twilight, and also encountered intermittent light rain reaching the ground. The headwinds buffeted us hard, shaking the vehicle some and compelling a little white-knuckle gripping of the steering wheel on Ryan’s part. Dust and grit reduced visibility to less than a mile, making noise like sleet as it bounced off the windshield at times.
We also saw a sporadically splendid display of anvil crawlers and a few CGs from the northern cloud shield of the MCS that was moving across the OKC and Blanchard areas at the time. After retrieving my vehicle at Ryan’s, I went to eastern Norman and attempted some lightning shots ahead of the leading gust front, but nothing too spectacular…I kept missing the brighter and closer CGs before the electrical area got too close to shoot safely.
Tri-County LP
Newcastle OK
8 May 11
SHORT: Right-split LP storm an easy drive W of Norman
LONG:
Dryline storms seemed a long shot, given the intensity of the elevated mixed layer and the stout capping implied by the morning soundings. High-resolution, convection-allowing models such as the HRRR showed nothing in their reflectivity forecasts. Still, models can be wrong, and deep thermals clearly were likely with surface temps soaring past 100 degrees F on the W side of the dryline.
while doing assorted errands and chores domestically, I kept intermittent watch on the dryline located a tantalizingly close distance to our NW through SW. By mid-afternoon, a string of large, high–based cumuli developed from S of I-40 in OK southward past the SPS area to ABI, the nearest robust area of convective agitation being SW of CHK. After several images, some of those towers began to glaciate, with reflectivity echoes appearing on both FDR and OKC-area radar scopes.
To hell with convection-allowing models…the real atmosphere had decided otherwise! Therefore, I decided to go W a short distance for a peek at the storms.
The first (easternmost) cells near CHK, that had prompted a severe thunderstorm warning, were dying; but by the time I arrived just SW of Blanchard, a new set of splitting left and right movers was underway to my WNW, W of Minco. At first the left-moving storm seemed dominant; but I knew the right-mover should take over if it could survive the capping, given favorable deep-layer shear, increasingly curved low-level hodographs and about 200 m2/s2 of effective storm-relative helicity.
And so it did. As the left-mover got fuzzy and shriveled, and as I moved to a position several miles NNW of Newcastle, the right-split ( here seen to the W) sported a vertical wall on its N side. I let the storm move toward me (and slightly to the N), watching the base expand but become a little more ragged as it did. The storm kept cruising to the ENE toward southern/central OKC, and weakened. Convective inhibition was proclaiming its dominance over convective processes! End of intercept.
On the way back, I drove trough that art of western Moore that contains no trees greater than 12 years of age. Today’s leisurely storm-observing jaunt was a monumental contrast to that day twelve years and five days prior, thoughts of which flooded my mind as a testament to its memorial indelibility.