Bennington Tornado

November 17, 2013 by · Comments Off on Bennington Tornado
Filed under: Summary 

Bennington KS
28 May 13

High Plains Therapy, Day 5 of 5

SHORT: Absolutely amazing chase day, top-5 all-time quality. After a very leisurely and relaxing morning on cool side of boundary, and long lunch, intercepted stationary supercell with two tornadoes near Bennington KS. Observed violent and often large tornado from one spot for over 1/2 hour as it underwent multiple shape changes and precip wrappings/unwrappings to our W.

LONG:

Background
Fans of “The Matrix” will get this. Pretend you are Morpheus and I must select from five pills instead of two. You ask me, “What if I told you that you would be presented with five violent-tornado days in Kansas and Oklahoma this season? On one of these days you will be at work. On three others you will chase but see no tornadoes. Only on the remaining single day will you see the event…but you get to choose which. ”

    YELLOW PILL: Photogenic sunset tornado in western Kansas and one or two others from same storm, with other messy storms nearby.

    PURPLE PILL: Two raging, roaring beasts in the central Oklahoma Crosstimbers with occasional, briefly unobstructed but amazing views; sucker storms in Kansas.

    BLUE PILL: One photogenic tornado, but it’s yet another deadly, horrible monster in Moore. A ghastly and unwelcome event, for sure.

    GREEN PILL: Mostly very visible, sometimes rain-wrapped brute, nearly stationary for 45 minutes, at times audible; if you want, you could put out camp chairs and coolers, and have a five-course tailgate picnic while observing safely.

    RED PILL: Huge, diffuse, erratically moving/expanding and highly dangerous mess that kills respected friends, nearly takes several others, and makes everyone you know profoundly saddened.

Immediately, the red pill is tossed, followed by blue. After careful consideration…

This was the day of the green pill.

Words cannot express how glad I am, several months later, to be able to say that–as frustrating as the yellow, purple and blue days (18-20 May) were at the time. The red day, I was at work and damned glad of it; I am quite satisfied to have been on the evening shift instead of tangling with El Reno’s tornadic phase.

Decisions and leisure
Before going to sleep the night before, in Smith Center, KS, I knew I had just one chase day left before having to return home for an evening shift on the 29th. Already seeing supercell potential for the 28th in two main areas–upslope flow with large hodographs but high cloud bases (eastern CO) and big hodographs, with low LCLs and high moisture along a boundary (in central to northeastern KS)–the choice from Smith Center was pretty easy. As much of a “structure guy” as I can be sometimes, this day I’d have to go for the conditional but potentially juicy tornado threat that was mostly on the way back to Norman. “If it stays capped, at least it’s just a few short hours home.”

Perusal of morning data and short-term progs confirmed that a front was stalling ENE-WSW across KS, obliquely intersecting a dryline that would mix E to somewhere not far W of SLN by mid-afternoon. Low-level winds and mass convergence weren’t particularly strong, but would improve through the afternoon as absolute and differential heating (lots of low clouds N of the front) augmented boundary-based left. The target was obvious–the SLN area or a tad north–only a couple of hours away, with at least 6-7 hours to get there. I liked that news.

Being north of the front, in cool air shaded by low stratus, I wasn’t in any hurry to bake under the high, midday, warm-sector sun of late May. Instead I pulled off a couple of times between Smith Center and Luray simply to open the windows, recline way back, and sit in quiet solitude: just me, the cool breeze, the green, undulating prairie, and songs of birds. So relaxing was one such stop that I actually dozed a little. There’s nothing like a stereophonic meadowlark lullaby to soothe the soul and cleanse the mind.

By the time I hit Luray, the stratus had become stratocu and was breaking into scuddy rags. As I fueled there, Tony Laubach (who was headed from SLN to Colorado) posted a message informing me of a horrendously long traffic backup along eastbound I-70 south of me, and W of SLN, and advised alternate routes. Grateful for the advice, I went down K-18 toward Lincoln, generally aiming for the Bennington area near US-81.

Still with plenty of time to kill, I had a long lunch in Lincoln, nibbling away on an Italian sandwich and salad buffet at Pizza Hut while checking obs, and also, checking in with the progress of my chase caravan partners. By this time, I was glad to be indoors; the boundary was nearly overhead, and temps were getting warm as the sun beat down outside. Objective analyses showed that deep shear was increasing, the front was quite vorticity-rich, mixed-layer CAPE was soaring past 2,500 J/kg, and the boundary only would get more unstable in the next couple of hours as it cooked. The dryline intersection was due south; so I eased on over to the US-81 rest stop near Bennington to stay downshear from that.

During my stay at the rest stop, the Dudes, Dudette and Dogs crew finally finished with their windshield replacement in SLN. That took so long that chasing in Colorado was absolutely out of the question–and what do you know, about the time they were ready, and while I was throwing rocks at the rest area and scanning the skies, big towers were going up all around SLN. Isn’t that convenient?

Chase on
The deepest early towers formed almost overhead and started moving ENE along the boundary. I headed through Bennington toward Junction City to stay ahead of them, just in case they evolved into a storm, with an eye back toward that intersection near SLN. Way off in the distant NE, a huge pile of convection was visible through sporadic low clouds. On radar, that sucker was evolving explosively in just a few scans, from a cluster of echoes to a gnarly supercell with classic hook and tremendous, tornado-warned velocity couplet.

Only briefly was I tempted to go that way, however; the storm was over 90 miles away along an indirect route. Seeing Eddie Aldrine’s report of a large, slow-moving tornado near Corning (NNW of TOP) actually encouraged me for potential nearby. Surface vorticity and low-level helicity were comparable…and CAPE was bigger. If that storm could produce a fat, long-lived hose, surely anything that went up between me and SLN could be special. I stayed put near Talmage to monitor nearby towers and a few weak echoes newly developed just NW of SLN.

Meanwhile, the people and animals of the companion crew were on their way toward a meeting spot between Talmage and Bennington when the echoes NW of SLN went absolutely berserk! In what seemed like no time, the western sky grew dark with heavy anvil shading and a big supercell started to take shape W of Bennington. We joined forces and wandered N a little, thinking (erroneously) that the Bennington storm with the distant but big updraft base would move NE.

After a brief chat with the original Twister Sisters and another examination of convective trends, it became apparent that this storm was stuck in place, anchored immovably and telling us, “I’m not going anywhere. You have to come to me!”

Little tornado, big tornado
Back down to K-18 we dropped, then zoomed W toward Bennington. Rolling over some hills, we saw an odd protuberance just S of due W under that distant base…funnel! The condensation funnel briefly grew fully to ground contact…tornado! However, we didn’t dare stop to shoot, since this fleeting vortex likely was just a teaser. We knew what the Corning storm did with less, and didn’t want to be out of position for the big show from that big base.

So it was. We crawled through, then past, a nest of chasers parked and driving hither and yon, in and around Bennington. Easing a little closer, we found a relatively clean position with safe pull-off and southward escape option about 1.5 miles WNW of town along a paved, N-S road. Though a tree row was about 1/2 mile to the W, cloud-base rotation was increasing, and we dared not gamble on another vantage.

Just in time too…for enough low clouds dissipated around the storm to reveal nicely spiraling structure overhead, while a wall cloud began churning. We thought tornadogenesis was imminent every few seconds for another 5-10 minutes as the wall cloud (wide angle view) turned around and around and around at visual speeds I’ve only seen with tornadic events, with similarly rapid tail-cloud inflow. I tried to call this in to TOP, but got a busy signal.

Finally, a funnel formed on the left (S) side of the mesocyclone, quickly becoming an obvious cone tornado. A brief burst of CG lightning strikes a couple of miles to our E and NE sent me back into the vehicle, whereupon I got another busy signal on calling TOP. From here on, I called the updates into Hastings instead, for relaying to TOP.

A welcomed development: the lightning quickly calmed down, at which time I could have whipped out lawn chairs, sat back, kicked up my feet, cracked open a couple of cold ones, eaten a pizza or two, and enjoyed the view. For the next half hour, we stayed in that spot, watching the tornado grow in size, shape-shifting from fat stovepipe to barrel to wedge and everything between, a big doofus of a tornado lumbering slowly in a confined loop to our W, SW, W, and NW, getting close enough to hear but not to compel evacuation, nearly disappearing in precip then emerging again, more than once, until it ultimately got too rain-wrapped to see anymore. Then it kept going for awhile longer.

Being able to stay in one spot and watch a quasistationary, violent tornado go on (and on, and on…) in mostly uninhabited countryside…this was a completely unfamiliar and wondrous experience. Behind us, in Bennington, sirens wailed on and off for most of an hour, never needed but definitely justified–for the supercell could start moving anytime. Fortunately for the town, it didn’t, and fortunately for us, as we were between the tornado and those sirens.

Thanks to tornadic translation vectors resembling those of a two-year-old on a tricycle, I had time to call in several updates, take well north of 100 photos, post a live phone shot or two to Facebook, and just put the camera and phone down and stare with awe and appreciation at the atmospheric event unfolding just a couple of miles to the W. In fact, at one point, as the slow path loop got closest but turned northward, I closed my eyes for 30 seconds just to listen to the tornado’s deep, low voice and feel the inflow it was consuming, undistracted by anything visual. This, I promise you, was an ethereal, transcendental experience. How often will one get that opportunity?

Many moons ago, DF had vowed to release the cremated remains of his late canine chase companion, Thunder, into a tornadic supercell’s inflow. When I looked to the left and saw him shaking a bag into the strong, warm easterlies, and saw the ashes wafting westward across green fields toward that big tornado, I nearly shed a tear. Somewhere in doggie heaven, a big, goofy leonberger (who himself had seen more than a few tornadic supercells in his short life) was smiling and wagging his tail.

As for the tornado at hand, here’s a selection of images every few minutes through the rest of its visible lifespan:

    Fat cone with tail cloud

    Thick cone, wide angle with ambient storm structure

    Barrel under big wall cloud, opaque rain-wrapping

    Very fat hose, descending reflectivity core shed

    Even fatter hose

    Absolutely classic pose–big tornado, big wall cloud, big base

    Another DRC, thick precip wrapping

    Wedge, opaque curtains all around

    Slight zoom view of wedge (could hear it at this point of closest approach)

    Wedge with ragged, possibly multivortex filaments to its N, meso getting quite strongly occluded

    Barrel in the rain

    Near-wedge again, thick rain-wrapping

    Deeply rain-wrapped, barely visible thick, tubular cone with tail cloud nearby

    Fattening again through precip gap

    Last certain view of tornado before wrapping precip got too thick, once and for all.

Closing it out

We waited a few more minutes of waiting for a visual reappearance, while precip curtains orbited very fast about an inferred tornado location. It obviously was still going, and would be for at least a few more minutes. However, we also knew that no tornado survives that deeply occluded and buried in precip for very long; one only can suck in so much heavy precip before the inflow air mass becomes too dense and stable.

Seeing the rear-flank cloud edge (and core) extend nearly overhead, we decided to go back through town a couple of miles and take a big-picture perspective. This storm now resembled a large, HP drum, maybe with a dying tornado still buried in there somewhere. Seeing some rotation in a cloud base ahead of the core, we went back through town again, observing a brief, rotating wall cloud that soon got undercut by outflow.

Thinking this storm might finally move off the hodograph origin, we went W and S on K-18 across Salt Creek and briefly observed the big, turquoise-cored HP storm from a roadwork area (looking NNW and looking SSW). Other cells were forming atop its outflow, but upshear, merging in and messing up the structure.

After jumping a few more miles to the SSW, we sat in the dimming daylight for one last look at the steadily disorganizing supercell, still in the same area and surely dumping astounding storm-total rains, before heading the few miles S into SLN for celebratory dinner. Good times with friends, followed by an uneventful 4-hour drive home, capped off a decidedly successful five days of High Plains Therapy. The next day–back to work, rejuvenated and alive with the passion for the smorgasbord of atmospheric violence!

Smith Center Tornadic Supercell

November 14, 2013 by · Comments Off on Smith Center Tornadic Supercell
Filed under: Summary 

Smith Center, Esbon & Mankato KS
27 May 13

High Plains Therapy, Day 4 of 5

SHORT: Wild day. Intercepted tail-end storm W of Smith Center KS that started CL and became messy HP, saw at least 3 tornadoes therewith. Fateful hail later encountered near Mankato.

LONG:

Prelude to action
Three days of this weather pattern had graced us with some outstanding storm structure and lightning in Colorado, Nebraska, South Dakota and Nebraska again. On this fourth day of the five I could chase, we started out in Grand Island for what promised to be a fairly short trek into extreme northern KS–me in one vehicle and a lot more protoplasm in the other: DF and Samara, “Downtown” Brown, Ross da Boss, and intrepid leonbergers Porthos and Trego. In my vehicle–music, calm sailing, and the hum of the road. In theirs–canine farts…from very, very large dogs.

Strengthening deep-layer wind profiles, the best low-level moisture content of the warm sector so far in the pattern, strong CAPE, a deepening surface low over western KS, and a quasistationary baroclinic boundary near the KS/NEb border, all made the target zone fairly obvious. The dryline was a possibility, but with capping a major concern, so it was downshear boundary or nothing for us. Wind fields certainly would be favorable for supercells. Lower LCLs than previous days amidst enlarging late-afternoon hodographs offered some glimmer of hope for a tornado if the storms first formed, and the modes didn’t get too messy too fast.

Unfortunately, with such a readily apparent target would come throngs of actual and wannabe-chasers, likely followed by looky-here locals, and we knew this. Finding safe navigation options off the main roads would be important to minimizing the hassles and hindrances to safe storm observing posed by traffic jams. Yes, traffic jams in rural KS! How sad is is that we have to consider this anymore? Still, I wasn’t about to let that ruin my enjoyment and appreciation of what nature had to offer, if I could help it at all.

After a long wait N of Stockton, we finally watched several towers arise to our NNW and NW, initially elevated N of the boundary but deepening into cumulonimbi and backbuilding. Meanwhile deep towers fired to our S and SE, in the warm sector E of the dryline. The latter didn’t benefit from as much forcing for low-level mass continuity as provided by the boundary, but had access to higher surface-based CAPE, at least at first. We wandered S and E, monitoring and remaining in play for both areas, when the northern storm cluster finally backbuilt close enough to the surface boundary for Tail-end Charlie to get really happy.

Tornadic stages

Overshoots and thick towers pumped through the persistent southern storm as we turned N out of Osborne toward Smith Center. We got a good view of the initially high base while approaching Smith Center, then set up just W of town with just a few minutes to observe the broad but increasingly well-organized updraft region before the flanking gust front would reach us.

An otherwise undistinguished area of the cloud base roughly in the middle of the last shot, between precip areas, started to rotate quite noticeably. Why? We didn’t notice any particularly telltale signals, such as an antecedent RFD cut or obvious occlusion process. Maybe this was the stretching term at work–a “nonmesocyclone” tornadogenesis process in a supercell, fortuitously located under an elongated updraft area and ravenously sucking a straw of horizontal vorticity. In any event, a weak tornado formed–a dust whirl under the little area of cloud spin, so feeble at first that it took us a couple of minutes of staring to be sure. There was a minute or two gap between obvious dust whirls, but with continuity of cloud-base rotation above, I considered it one tornado with a vortex too weak or too vegetated at the base to raise dust in that intervening stage. Off and on, but mostly on, the little tornado that could stayed visible, lasting for six minutes before being plowed under by the rear-flank gust front of a low-level mesocyclone deepening to our N.

With the supercell changing character and moving abeam of us, it was time to “head east”–and I don’t mean the ’70s rock band. The warning and tornado report attracted swarms of chasers and pseudo-chasers from several counties around, many of whom could be seen on Spotter Network animations about-facing to this storm as soon as the red polygon appeared. US-36, E of Smith Center, turned into a long, eastward-slogging train of vehicles paralleling the storm just to its S and SE. For a little while, we were caught up in that mess, and had trouble finding good vantages.

We needed one when an area of low-slung scud to our N and NNW, under a cyclonically turning inflection notch of the updraft-downdraft interface, started turning itself as it rose off the ground. The persistent, obviously but slowly rotating cloud column was in contact with both ground and cloud base for about a minute. The whole very weakly tornadic circulation (located just N and NE of Bellaire and NW of us ) lasted about 3 minutes.

Farther N, the storm cranked up a robust mesocyclone, but one hard to see from the S, through intervening precip. Finally, this storm was getting serious and bidding bye-bye to the “cheesenado” phase. Our vantage wasn’t ideal, and we wanted to get E and N to reposition ahead of the new, deepening storm-scale circulation. Several minutes of waiting for a hole in the US-36 traffic didn’t help. As a result, we did get N on the alternating paved/dirt road into and out of Esbon, but not in time to see most of the lifespan of the big, rain-wrapped tornado NW of town.

Instead, we popped N out of Esbon barely ahead of a deep, dark, circular drum of rotating precip, churning menacingly and moving ESE directly at us. With no vehicles driving toward our position (but several high-tailing it away!), and a narrow but very passable road upon which we had just driven as a return/escape outlet, we safely executed requisite 5-point turns to flip back southward and, as a Texan like me would say, “Git the hell outta thar!” After they finished the turn and as I was amidst that process, I heard Keith yell over the radio, “Tornado to the west!”

Sure enough, inside the orbiting moat of heavy rain, I could make out a low-contrast, wedge-shaped mass of darkness, itself rotating furiously. Seeing that the E rim of the meso still was W of us, though not by far, I radioed to the now rapidly fleeing Dudes, Dudette and Dogs vehicle: “Go ahead south! I’m gonna take 30 seconds to shoot then I’ll get the #%^! outta here!” As I parked and jumped out, the mass (which indeed was the infamous Lebanon-Esbon tornado) narrowed to a barrel shape, then by the time I did shoot, a thick cone, getting lower in contrast again (enhanced version of last shot) and still densely swaddled in precip.

Meanwhile a newer and rapidly strengthening mesocyclone was whirling with considerable vigor to the N, raising dust and sucking it in, wrapping big gobs of precip, who-knows-what going on inside. I could have sworn I saw some vortices merry-go-rounding in there, but contrast was too poor to say for sure. No tornadoes showed up in storm reports during that phase, but at a minimum, it was a very intense “meso on the ground”. The southern, older, tornadic and deeply occluded circulation still was moving generally toward me, the tube narrowing to the extent I could ascertain. [Storm surveys later showed the Lebanon-Esbon tornado dissipating right before it reached my road.] Still, not wishing to play chicken with a beast like this (the storm always decides who wins that game!), I jumped back in and gunned it southward also. Everything since the 5-point turn occurred in less than 45 seconds, 15 longer than estimated: stop, jump out, shoot WNW at occluded/tornadic meso, run across the street, shoot N at new meso, run back to vehicle, throw ‘er into gear, slam the pedal down and bust south.

Adventures anew

Apparently, my storm-intercept companions used a great deal of haste in their escape; for by the time I reached the next intersection, they were out of radio range. While I turned E to stay ahead of the rear-flank gust front of the new meso, it turns out that they had kept going S back toward US-36. My east road, though gravel and dirt, was outstanding and very firm for a few miles, allowing me to gain a welcomed cushion by the time I reached Burr Oak. There, I briefly stopped to examine and shoot the main mesocyclone area to the NW, now deeply wrapped in a north-Texas-style HP stormzilla.

Opening up some space between me and the rear flank also became crucial when two things happened at once, E of Burr Oak:
1. A heavy shower that had formed to the S passed directly over the road ahead, and
2. Preceding the next paved N-S option, I encountered a 2-mile stretch of the same “road”, which previously had been a deeply rutted strand of slop, and now was being rendered horrendous by the shower.

Thank God and Ford for high-clearance 4WD and the ability to use it properly. Prior practice mudding and sand-driving paid off here; lower-set SUVs (4WD or not) and any sedan would have ended up high-centered past the axles in that nightmarish quagmire. There was serious white-knuckle driving down a certifiably awful track, among the handful of worst mapped roads that I’ve experienced. I was counting the tenths of a mile on the odometer, trudging along through the viscous morass, not daring to stop lest I lose momentum, wheels flinging giant gobs of goop every which way. At least there were no other chasers on that wretched stretch…for good reason! Somewhere in that ordeal, I got brief coverage and a phone call from my comrades, but was in no position to stop and answer, requiring full-on concentration and the use of both hands for every millisecond.

Finally I emerged on to the hard, dry N-S road, likely shedding well north of 200 pounds of mud to rain and centrifugal forces as I zoomed off southward toward Mankato. One last look back N at the HP storm gusting out, then a peek at a new Cb forming to the SE, and what appeared to be a newer, elevated supercell to the W (atop outflow from the big HP), dictated the next step superbly: get SE.

Upon reaching Mankato from the N, I got back into reliable cellular coverage and re-established phone contact for a meeting E of town. By this time, the elevated supercell was moving into Mankato. Thinking we had a decent shot at a spectacular sunset on the back side of the convective mass, and that most of the core of the ESE-moving storm would clear town by the time we went back through, that’s what we tried. We tried too soon.

Skirting the N edge of the main core, we encountered mostly heavy rain and marginally severe hail, except for the large ice bomb or three that bounced high in the air off the ground. Well, a few bounced off vehicles too. They took a 3-incher to the windshield, and I heard and felt one or two really fat ones clunk the roof where decent dents later were seen. Fortunately it was over quickly, but we were just a little too hasty going in. I took the blame for this bad call, because (clearly wrongly) I thought the meat of the core was S of US-36. The Dudes, Dudette and Dogs crew were upset, and rightfully so.

Unaware to us at the time, and purely by serendipity, this would turn out to be one of the best things to happen to us all, because it forced them to limp into the nearest big town (SLN) to get a windshield replaced, effectively nixing their prior intentions to chase in Colorado the next day. Meanwhile, the sunset wasn’t calendar-worthy, thanks to light blockage over most of the sky from clouds farther W, but was beautiful and enjoyable nonetheless.

As for me, I didn’t feel like driving all the way to SLN in darkness and deer crossings, and instead got a cheap room at a little motel in Smith Center in time for a late dinner. Though this chase now will be known forevermore as the ideal setup event for the nest day’s feast, in its own right it was a fine fourth part of five in the journey of High Plains Therapy.

Elaborate Tornado Avoidance Techniques

July 27, 2013 by · 2 Comments
Filed under: Summary 

Southern Kansas to east-central OK
19 May 13

SHORT: Intercepted 4 supercells in 3 tornado warnings and saw no tornadoes: 1. NW of Ark. City KS, 2. near Parkland OK (middle storm of OK triplets), 3. ENE of Prague, 4. Near Okemah and Okmulgee. Somehow managed to miss all the tornadoes two days in a row.

LONG:

Setting up “the day after the day before the day”

Having intercepted clearly the most unfavorable of several Kansas storms the previous day, the “day before the day”, Rich T and I were determined to get on a tornadic supercell on “the day”.

A classical setup set up for the corridor from southern KS to central OK, with rich low-level moisture return, a strong dryline, a lack of antecedent precip to mess up the boundary layer, large low-level hodographs, and strengthening deep-shear vectors with a decent component across the dryline. In short, this was a prime southern-plains tornadic-supercell regime, the only potential hitches being mode certain initiation with storm-mode concerns up north (near a cold front) and initiation questions farther south.

Our strategy, therefore, was to get in between the two ends and be in prime position to strike like a predator at the best developing storms in a corridor from OKC-ICT. We arrived early at a truck stop N of Perry and awaited development. Early storms near ICT looked interesting, even supercellular and potentially tornadic, (one did produce there), but also, potentially tangled up quickly in a messy cluster near the front. Fateful decision #1 had been made: blow off the early, tornadic ICT storm for more discrete and ostensibly longer-lasting activity to form closer, later.

Two areas of convection began to develop almost at once: just W of us, moving NNE toward Wellington, and about 75 miles SSW of us, on the NW fringes of the OKC metro area. Either was easily reachable. We had much better visibility on the closer activity, which seemed likely to remain in a favorable environment well into mature stages. Fateful decision #2 was sealed: check out the closer storms, which would take us away from central OK. We had seen this picture play out several times before–jump on middle or northern convection only to have the southern storm near OKC produce tubes (whether or not we would see one with our convection). Still, we risked missing something closer to home for something closer to us.

(Somewhat) northern play

Fully aware of that dubious history, we headed N to near Blackwell and took a look at the growing Cb, already showing some supercellular characteristics on radar–as did an initially separate, trailing storm behind the cold front and to our storm’s WSW. This is how it looked before the base came into view. We hopped N of the border, zigzagging E and W a little across I-35 N of Wellington to get in viewing position. The storm turned out to be a messy HP with poor contrast. Only a brief, surging attempt to wrap a mesocyclonic occlusion was visible, with a funky, spiked, ground-tickling tail cloud, before it buried itself deeply in rain again.

Optimism wasn’t the word here. The storm had 1) accepted a cascade of percip from the dying remnants of the post-frontal supercell, 2) dealt with big towers and showers forming and merging into its rear flank, and 3) interacted with a new, quasi-linear frontal segment nearby. Meanwhile, radar showed the storms near OKC coalescing with frightening speed into a big, honking supercell near Edmond. This is when we started getting that sinking feeling…here we go again.

Back to central Oklahoma

Fateful decision #3 actually didn’t take long: let’s not linger with this HP rubbish, and try our best to bust SSE ahead of the now violently tornadic convection just NE of Edmond (or anything that might form farther upshear). We didn’t dither on this, which made an intercept from that distance at least marginally feasible. Somehow, the at HP rubbish, and accessory convection building into its flank, produced a small but photogenic tornado near the South Haven exit of the Kansas Turnpike…not long after we left!

Unaware yet of that morale-crushing development, we made decent time southward on US-77/177 through PNC to the Cimarron Turnpike, then SE on the speedy slab. All the while, we could see the booming, huge flanking towers rolling into the back side of the leading storm, now near Stroud, with a known history of atmospheric violence. However, as we closed in for a potential end-around the back side, potentially in the Bristow/Kellyville area, the convection was softening, the mesocyclone weakening, the storm moving into somewhat cooler, lower-theta-e air.

Resigned to missing all that storm had to offer, we saw two newer supercells on radar, and fuzzily from the sunny N side–a small one to our near SSW, near Carney and trailing behind the first. The westernmost storm was organizing fast…over Norman! That was the cell we really wanted to see, with its unimpeded inflow and longer prospective resident time in juicy air…but the middle storm (which was sucking some outflow from the formerly tornadic lead supercell) was smack in the way.

Since the middle storm was considerably smaller than the others, with lower VIL and MESH hail indicators and a thinner forward-flank core, we made fateful decision #4, hedged a bet against the risk that could strengthen its hail production, and headed S through its forward-flank core toward the Agra/Parkland area. True to its algorithmic evolution, that core indeed contained only marginally severe hail and was surprisingly translucent, allowing us to pop out of precip a safe distance of 4-5 miles ENE of the storm’s mesocyclone. We could check this out briefly while plotting a course to get ahead of the Norman storm, by now producing a tornado over Lake Thunderbird–just a few miles from both my house and Rich’s. That sinking feeling came back again.

Yet we weren’t obligated to leave this storm just yet, not with us in an unusually good vantage point for this hilly, forested part of the central Oklahoma crosstimbers, and a tightening mesocyclone approaching rapidly on track toward a spot on the highway immediately to our north. From a distance, the main cloud area was so low that it might have appeared tornadic, but we certainly were close enough to confirm otherwise. As it crossed less than a mile away, the persistent, deep, scuddy lowering was rotating, but not especially fast, and had no debris or dust beneath. Inflow felt rainy and somewhat cool the whole time, which seems to have been more related to the earlier storm than this one. Nonetheless, it tried hard (deeply enhanced crop)…just not hard enough.

Having spent just a few minutes examining that supercell, we made our expected run for the former Norman storm, now approaching Prague, offering a tremendous radar signature, and yielding terrible media-broadcast tales of tornadic destruction from the Dale-Shawnee area. By the time we got to I-44 and US-377, it was obvious we would have to either: 1) make a big zigzag to take a safer approach, or 2) penetrate this storm’s forward-flank core too, but come out perhaps even closer to what was known to be a dangerously tornadic mesocyclone on 377.

No, thanks…fateful decision #5–live to chase another day! I don’t know what would have happened had we turned stupid and tried to core-punch that sucker, but I’m glad not to know. Even though the NWS tornado mapping for the event shows a break at 377, the risk was too great…and of course gorilla hail can take out a windshield and end a storm intercept quickly. Notice also the tornado path NE of Prague, between there and Welty (the W road E0960 off OK-48, halfway from Bristow to I-40).

Zooming safely ENE on I-44 then S on OK-48 toward Welty, we passed instead through far-forward-flank precip that was dense but only rain. We passed through hilly terrain near Welty and hunted for the first relatively open view of the big supercell that wasn’t right in the path of the meso. By the time we saw the storm, looking W on side road E0980 S of Welty, it was a deep, dark, low-contrast, HP drum. The storm definitely was producing a tornado at the time based on official mapping, but one we just couldn’t see with our eyeballs because of extremely dense wrapping precip. At the time of the last shot, the tornado would have been directly down the road, in the distance (deeply enhanced crop).

Shortly after I walked a little way down the road to try a different angle (deeply enhanced crop), a small car pulled up. The unknown chap inside noticed I was shooting the storm, and started an impressive routine of big-timing, offering instruction about the supercell’s structure and what was going on where. His descriptions were fairly accurate in a general sense, but this presumptuous little game was wasting both of our times and just had to stop. I’ve seen and studied a supercell or two myself over 28 years of storm observing and professional meteorology, so it was hard to resist temptation to bust out laughing. Instead I decided to have mercy and let him off the hook relatively painlessly. Once I could get a word in edgewise, I succinctly discussed the likely pattern of vorticity lines around the wrapping, precip-filled occlusion downdraft and its interface with the forward-flank gust front of a supercell of this configuration and morphological stage. [Thank you V.O.R.T.EX.] Quickly my interlocutor quieted down and turned his attention back to the storm. 🙂

Duly amused and a bit grateful at not being recognized, and not wanting his vehicle (or its glare) to take up too much of the shot, I wished the dude good luck, and jogged back up to the vehicle. Rich (who had stayed by the vehicle) and I watched hard for any evidence of the ongoing tornado somewhere in there (deeply enhanced crop). The rotation of the precip cage and surrounding cloud deck was impressive, but we still couldn’t see the tornado by eye. Even the deep enhancement leaves room for doubt.

After that, the visual appearance got even messier, the mesocyclone shifted NW then NNW of us, and RFD precip began to hit. We bailed S, glancing back at the remnant circulation crossing behind us (by then nontornadic, as it turned out) expecting that to be our last view of the storm in the fading daylight. An awful lot of rain was falling well S of the hook of our previous supercell, and once we got out of a cell-phone hole and saw radar again, it was obvious why. Yet another supercell had gone up farther SW, playing a game of mutual hindrance with the former Norman-Shawnee-Prague storm. They were aligned in ideal geometry to dump rain and/or outflow into each other’s inflow regions!

Enough was enough

Despite its ragged and somewhat high-based appearance (looking NNE from near Castle), we followed the last supercell N a few miles out of Okmulgee before twilight and unimpressive structure mercifully ended the intercept. Somehow we had witnessed four supercells and no obvious tornadoes on a big-event day, and aside from that, had seen very little in the way of photogenic structure. On top of our chase failures the previous day, this dealt a most demoralizing blow; and that wasn’t the worst of it.

At some point in there, I learned that the beloved cat Iniki, who suddenly had fallen ill a couple of days before, had to be put to sleep by an emergency veterinarian the same evening, while I was out driving hundreds of miles and failing to see anything of note. I never got to hold her and say goodbye. This day officially sucked. How could doing an activity I loved so much get so stinking miserable?

We ran into Bobby Prentice and Scott Fitzgerald at an Okmulgee gas station, hearing of I-40 being closed on our way home due to tornado damage (indeed, it was). We didn’t need more bad news. Yet, to make matters worse, we then learned that the Shawnee tornado had been a killer, and also, crossed the power-supply lines N of Rich’s house and cut electricity thereto for many hours ongoing. His food was unloaded into my fridge and big freezer, and he stayed at Elke’s and my place that night.

Our wish for the 20th was to turn the heretofore painful storm-intercept fate of the previous two days around on the third and final day of this weather system, despite fighting the urge not to even bother…

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