Spring 2009’s Fantastic Grand Finale

July 10, 2009 by · 1 Comment
Filed under: Summary 

17 Jun 9
Northeast KS and South-central Nebraska

SHORT: Outstanding. Two chase days in one. Intercepted stack-o-plates tornadic supercell between Belleville-Seneca KS but missed Marysville tornado(es). Long drive W and N for several tornadoes and spectacular supercell from Buffalo County NE to near York, including 17-minute dusty tornado near Aurora. Let tornado get close enough to hear then backed off. Aurora and GRI got very lucky w/timing of occlusion cycles.

LONG:

Looking at morning data and maps from our lodging in CNK, the forecast scenario looked so clear to me on this day, it almost was frightening in its own right. Play a diurnally cooking frontal zone across south-central Nebraska, with strong heating and frontal lift likely to breach the cap and fire at least a supercell or two before sunset in an environment of very impressive moisture and large low level hodographs. It seemed simple enough: Leisurely wander up toward that nearby target area — say, to HSI, eat a good lunch, and and wait for additional clues and/or storm initiation. And so we did. Then a lyin’, cheatin’, seductive storm intercepted us, temporarily stole our hearts, and almost kept us from our true date with the true love of supercellular splendor.

This really was two fine storm intercept days in one, the first beginning before noon!

Early Elevated Supercell in North Kansas

We left our rooms around 1100 CDT, headed N toward Belleville, intending to grab some fuel and proceed to HSI. DF, Ross and the big dogs were going to get some grub, then meet us somewhere along the way. As we headed N on US-81, still in the forenoon hour, big towers appeared to our NW! They were not far away, and W of Belleville. No problem, mon! We could get a drive-by look at some early, elevated storms around noon, be under their shade to keep the car cool, and if lucky, maybe see some hail.

At our vantage a couple miles W of Belleville, two updrafts initially appeared, and also appeared very elevated, with the typically rippled, undulating character of warm-advection clouds, inflow obviously off the surface. But the left one (quickly lowered toward a laminar feature developing beneath and became dominant. On one hand I was somewhat excited to witness the curious spectacle of what could become an elevated supercell; they’re typically very hard to see unimpeded by intervening low clouds and precip common to such regimes. On the other, I already was starting to get concerned that this strengthening storm could last long enough to become surface based, that it would be in a good shear and buoyancy environment if it did, and that under such a scenario, I would have to make a critical decision (influencing the chase fate of four chasers and two pooches) between this “sucker storm” right in our laps and the actual forecast area farther NW for late afternoon.

Such serious contemplations got interrupted momentarily by the diesel-roaring, slow-moving fanfare of a wide load caravan crawling E down US-36. What on Earth was the wide load, anyway? If anyone can identify specifically enough this curious, round little stone structure and its former function, I’ve got a Dublin Dr Pepper for you.

[Edit: It’s a 120-year old stone smokehouse, being moved from its place of construction to the county historical museum. See the comment below. I owe Elke a Dublin, not that she’ll consume it. ;-)]

A few hours later we would see the truck and structure later parked at an abandoned fuel station E of Belleville, while racing back W.

Meanwhile, the laminar band’s top rose and conjoined to the lowering midlevel cloud base, which itself flared into a banded formation. The process looked like building a supercell structure piece by piece, out of an erector set made of play-doh. Elke said, “it sure was fun watching that storm assemble itself.” It was still laminar, still smooth and fuzzy and a tad rubbery in form, but visually and on radar, a bonafide, elevated supercell. As it improved, potentially moving into very well heated and moist air, it also started moving east — away from our late-afternoon target zone!

Figuring we got an early start, and a couple hours’ diversion wouldn’t throw us off track, we headed E of Belleville to watch the storm for awhile. It evolved rather quickly from a pretty but obviously not surface-based storm

Oh Crap…Not-So-Elevated Supercell Anymore!

..into something not quite so obviously elevated with a rapidly evolving, low-hanging wall cloud rooted in the destabilizing boundary layer, as seen in wide angle from N of Morrowville (and as seen with and by DF). Great. This storm was taking us ever farther off on its diversion, and we were letting it.

The previously pictured mesocyclone died to our NW, and the storm appeared to grow rather high based and disorganized. We began to let it go at Morrowville shortly after 1330 CDT, in plenty of time to get back into our original target area. As the storm got off to our ENE and E, however, and almost out of clear sight, it “jumped flanks” eastward, a new and lower base developed with a wall cloud (distant zoom view looking E), it turned farther rightward and quickly organized into an obviously surface-based supercell on radar. Rats! Decision time…and a tornado warning helped to seal the decision. Maybe we did have time to get back in front of it briefly for another look.

We headed E toward Marysville, hearing of tornado reports just NNW and N of town. By the time we entered the W side of town, about 10 minutes after he last report, an old, back-thrown occlusion was evident off to our N, while the storm jumped flanks again and was spreading a precip-filled RFD from the new mesocyclone across the countryside to our NE. By the time we got ahead of the storm again, W of Seneca, it was very beautifully chambered and lit — but sucking cold air. We measured temps in the low 70s and upper 60s in the inflow, where they had been in the mid 80s before. A fine line could be seen in reflectivity imagery, arching NW from another, newer supercell well to our SE that was headed toward the STJ area. That outflow boundary still was spreading SW and W, while our storm had crossed it and was getting elevated again, this time for good. [I strongly believe the storm briefly became surface based and produced the short-lived tornado(es) as it interacted with the boundary N of Marysville). Time to go!

Westward Recovery to Nebraska and…Tornadoes!

The first chase day-within-a-day now over, the Belleville-Marysville-Seneca storm’s (lack of) future now assured, we felt we barely would be able to recover W along US-36, then N from Althol KS into south-central NEb with a couple hours of daylight to spare. Much of any time we made up by driving a little too fast on those wide-open roads was offset by a ticket we all got from a courteous and professional state trooper for 10-over just N of the NEb line, which we absolutely deserved and later paid without protest; in the net, we got to the target area about when we should have, just $69 poorer. There is a lesson in that. As the towers blossomed higher and broader, the anvil backsheared farther, the northwestern sky grew darker, the radar presentation grew more supercellular and we drew closer, I thought, “This storm better be worth that price of admission.”

We already had seen one occasionally spectacular, sometimes maddening storm over 150 miles away. This one would become, without question, one of my handful of most favorite storms ever observed.

While we approached from the SSE (from Franklin and Minden) the storm launched its early towers skyward with astounding force, backshearing an anvil and pumping tower after tower thereunder, thereafter. It also took a very short time to attain classical, hook-shaped supercellular appearance in reflectivity, though the low level shear was slower to tighten and organize as we approached. This was good, because right as we first got within view of the base a few miles WSW of Gibbon, there was a small cone tornado already in progress! We hurried legally to get into better position E of the eastward-moving business end of the tornadic supercell, and the first tornado (distant and hazy view) died before we could stop for a photo. Sorry!

As we still drove ENE along US-30 from Gibbon to Shelton, aiming to turn N before reaching Wood River, another tornado appeared beneath a broadening wall cloud. This time I did stop briefly to document it (wide angle and 70 mm zoom), but we still were jockeying for position and a few too many miles away. A couple other storm observers I know were closer, and independently confirmed both of these early tornadoes. At several points during the storm’s tornadic phases, I tried to phone in reports to the HSI NWS office, but got busy signals every time. Fortunately, several NWS employees who were chasing on their own time also witnessed the storm, along with plenty of local spotters and non-meteorologist chasers with Spotter Network connections who also were more than eager to share their video and photos online so that it all could be well-documented from almost any conceivable angle and distance.

We were hoping for more tornadic action as we tucked ourselves snug into the immediate inflow region, much closer to the main updraft area; but it took awhile for the storm to reorganize to that extent.

Numerous Cycles, Occlusions and a “Landspout”

From several vantages W and E of Wood River we watched wall clouds come and go, a few rotating briefly between several occlusions, one or two exhibiting lower-hanging, moderately rotating chunks of cloud material, but none seriously threatening tornadogenesis. [The darker puff of material that appears “below” the lowering in the last shot actually was a thick, non-rotating plume of falling precip behind the wall cloud, wrapping right to left through the back side of the mesocyclone.] Although the storm stopped producing tornadoes (for the time being anyway) as soon as we got right into potentially fantastic viewing angles, the variation in occlusion and circulatory regeneration processes was absolutely fascinating, fun and at times beautiful.

Looking WNW, here’s one new, small wall cloud developing as soon as the old one wraps in rain. In this wide-angle view, looking WNW across a verdant Nebraska corn field, the small wall cloud and RFD clear-slot cut through the supercell’s main updraft base, while an old occluded region is cast way back behind and to the NW. A few minutes later, when photographed at 55 mm focal length, the new wall cloud began to get a ragged, bifurcated look, while the old meso occlusion sported a flared, bell-shaped base and a pronounced lowering, as if attempting one last burst of supercellular glory before its demise!

We scooted ENE on US-30 then S on US-34 a few miles, avoiding the stoplights and slow local traffic of GRI, and hoping that any reinvigoration of tornado potential from these mesocyclone cycles would not happen until after the storm passed over town. As we were talking to a local spotter, who was there for the infamous 1980 tornado, we saw a faint dust tube under the base of the flanking line — a non-mesocyclone tornado (a.k.a. landspout). DF and Ross filmed it while I ran back to the car for a different lens than the wide-angle that was affixed to the camera. By the time I got the lens on and got back to my viewing spot, it almost was gone, but still can be seen faintly (super-enhanced crop-n-zoom), as the storm’s rear-flank gust front pushed the bottom of the translucent dust tube toward the left (S). This was a short-lived, inconsequential gnat-fart of a tornado, but it did happen — 2012-2015 CDT, estimated 5-6 miles WSW of Grand Island. Meanwhile, here’s how the supercell appeared at wide angle, as we looked NW in fading daylight, with the newer wall cloud and occlusion area to the right (E) and the older one to the left and more distant (W). The storm clearly was getting better organized, each new meso looking a little larger and more robust than the one before…

A Grand (Island) Transformation — The Phillips and Aurora Tornadoes

Good fortune kindly graced Grand Island and Aurora on this evening. That “magic hour” when inflow still is surface based, but the cooling surface temps lower the LCL, and the low level jet begins to develop and enlarge hodographs, was upon us. The storm politely waited until exiting GRI to respond to its improving proximity environment in an amazing way, then obligingly shut down its resultant ravages right before it reached Aurora.

Knowing that the best photographic contrast for low-light conditions would be to silhouette the base, we decided to get due E of the strengthening mesocyclone — by exiting I-80 at state road 2, then marching E on US-34 in step with (and just ahead of) the supercell. The strategy was deliberate, and for once, worked like a charm!

As we cruised E on 34 near Phillips, with Elke now driving, I turned to look out the window, saw a broad but strongly rotating funnel cloud behind us, and hollered for her to stop fast. I got out and shot this wide-angle of the broad, conical protuberance beneath outstanding storm structure. We were too close to get the entire storm in either of our wide-angle lenses, but the view looking WSW wasn’t bad either!

Intermittent dust whirls began to appear under the funnel as it tapered and lowered…tornado! The condensation tube coiled itself into a striking scorpion-stinger appearance, shown here in a zoom and also as part of a wide-angle structural view via Elke’s 17 mm lens. The tornadic meso was moving east toward us, and we weren’t far from it. This non-trivial challenge precluded setting up a tripod in the declining light, and I didn’t want the added noise and grain of high-ISO given such high dynamic range across the field of view. So instead I braced myself well and practiced blur-bracketing, i.e., shoot rapid-fire like hell, and trust that at least one photo within any given magazine-clip of attempts will be steady and sharp. Fortunately it worked when it counted. Most of my images of this and the next tornado were shot at anywhere from 1/20 to 1/6 of a second, hand-held!

The Phillips vortex lasted 5-6 minutes, but only a couple of minutes as a recognizable tornado. Suspecting another would follow, we zoomed east to allow the storm room to move and recycle, which didn’t take long. As we cruised farther E (sound familiar?), another funnel formed, a separate and distinct event from the one before, and I hollered, “Stop…another one!” We pulled off the road and watched the new tornado raise its own dust plume, while a peculiar column of rising dirt jetted up from a plowed field just to its south. Annoyed by the parked car with headlights blasting into my viewfinder and messing with the exposure settings, I ran across the street to shoot as the southern dust plume dispersed and the tornado kept plowing eastward toward our position. [If the dude who was running that car sees this BLOG, here’s a belated and hearty thanks for turning off those lights after I hollered at you.]

With escape options N, E and S at our crossroads between Phillips and Aurora, and vigilance for satellite vortices, I felt comfortable letting the expanding tornado get within 1/2-3/4 mile, close enough to hear the whooshing sounds as it churned through that field. It was the first time since 28 March 2007 (Hedley-McLean TX) I had been close enough to hear a tornado, and the most audible one since the 16 May 1991 Haysville KS event.

Hoofin’ It toward a Tornado

Nigh time to bail east again, we headed about the equivalent of a city block past the railroad crossing 1 mile W of Aurora to put some distance between us and the oncoming tornado, and to prevent being barred from escape by a train (just in case). Unfortunately, that also put the elevated light standards of the railroad crossing smack-dab across my view of the tornado. Already out of the car, I asked Elke to back it up to the E edge of the tracks. I then took off in an all-out sprint up the road, across the tracks and straight toward the tornado that was moving toward me. Somehow this felt neither dangerous nor frightening, but quite natural and whole and good. Of course, it helped that the escape machine arrived 40 feet behind me as I set up to shoot another photographic magazine-clip, which now yields one of my all-time favorites among my rather limited tornado portfolio. Even while bracing and shooting, I thought of how that scene reminded me of the content and composition of those old-time tornado pictures that graced the inner plates of Flora’s Tornadoes of the United States and Battan’s Nature of Violent Storms — the silhouetted vortex spinning over the road, looming ominously, trees and/or low buildings on one side or another to add texture to the foreground. I grew up on photos like those in the monochrome books of yore, and now I was privileged enough to be in position to capture one.

I’ll always remember the sound of that scene too — there was none but a light breeze, just outside the mesocyclonic surface flow. The road was devoid of traffic for a few amazing minutes. Aurora police blocked traffic coming westward from town (behind me), and the chaser caravans hadn’t arrived yet. I almost could have heard a pin drop, and certainly a train coming, even though the tornado was at peak size and only a little over a mile away.

Winding Down a Fine Storm Day

We headed through town promptly so as to not be caught there when the tornado arrived. I’ve often heard sirens blaring in towns while storm observing, but very seldom with a bonafide, obvious, mature and robust tornado bearing down. That made the experience finally frightening — not for me personally, but on behalf of the townsfolk, who were well-warned but whose lives appeared soon to be altered for all time. Fortunately it never hit Aurora. The vortex turned left (N) and crossed the highway before it dissipated in the twilight, sparing the town (the lights in the last photo), 18 minutes after genesis. Subsequently, the supercell appeared to become more cut off from boundary layer inflow, though it kept some spectacular structure (wide angle, and even wider angle) for a short while after dark, as it approached York.

At some point during our eastward trek ahead of the Phillips-Aurora tornadoes, I saw DF (who already had an injured back) hanging out his vehicle’s passenger window to shoot video, and hoped all the subsequently inevitable pain would be worth it! Ross was overjoyed as well, and I was thrilled for them both. They had gone through a great deal of trouble, effort, expense and literal pain to be there, and deserved the majesty of the tornadic supercell experience that unfolded.

It was a long way and a long day from that strange, truck-pulled edifice back at Belleville. Two gorgeous supercells, several tornadoes and an Applebee’s steak dinner later, we went to sleep very content with the best chase day in a long time, and a storm intercept season made very good after all. Even a stormless bust the next day in northern Iowa couldn’t dampen the satisfaction of hard-earned accomplishment, sprinkled in no small measure with good fortune of having the right vacation timing to experience a magical June of both supercells and tornadoes on the Great Plains.

Until next season…

HP Heaving on Hutchinson

July 9, 2009 by · Comments Off on HP Heaving on Hutchinson
Filed under: Summary, Uncategorized 

15 Jun 9
Central KS

SHORT: Observed skinny supercell from N between Scott-Ness Cities. Performed an end-around intercept on HP supercell-turned bow from E of Kinsley to HUT. Munched by bow/HP hybrid in HUT.

LONG:
Once again, we were faced with two interesting target areas — the “north play” near what turned out to be a warm frontogenesis zone along the KS/NE border, and the “south play”, along the prior day’s OFB over SW KS. I didn’t like the south play as much because of the forecast (later observed) smallness of hodographs and persistent SW flow right through the boundary for hours on end. Nonetheless, we headed that way from Oakley (despite being closer to the northern play) after three trends appeared:

1. Winds began to lighten N of the old boundary but not to its S (speed convergence) and

2. Midlevel (i.e., 500 mb) winds appeared stronger farther S, as proged, although low level shear and SRH were bigger in the warm frontogenesis zone, and

3. Storms erupted to our S.

I wanted to hold out longer for the N play, but convective bombs going off were too tempting when compared with the “pancakus” Cu around us and to the N. I’m not sure we would have gone all the way ENE to HSI for that amazing warm frontal storm, but we were in ideal position for the NW KS activity later.

A lone supercell formed N of GCK, here shown at wide angle from N of Scott City, then a separate, zoom view of the backside updrafts. In the background, another cluster of convection SW of GCK could be seen; those eventually would hog the inflow and choke off out storm. As we drove past its near N side, the updraft looked rather skinny, but was quite intense. Then too many other storms formed in too close a proximity to its SW-SE, and we had to make a choice — go back N toward the NEb border (no deep towers yet visible) or go a long way E then S to get ahead of the lead storm N of DDC. As we headed E past Ness, the lead storm started absorbing cells of assorted sizes to its E and “jumping” mesos eastward, forcing us to go still farther E before dropping S.

We finally did so through Larned, St John and Sylvia, encountering a few hailstones of unknown size in the far forward flank (heard ’em loudly, didn’t see ’em). Heading S toward St. John, I finally got a view of the business end off to the SW — a dark, menacing, HP supercell, absorbing yet another storm (itself with a high but circular/rotating base) into its forward flank. I might have seen the tornado near Macksville as a persistent, gray on darker gray, bulbous form back there in the mesocyclonic murk several minutes later (no photos…very low light, moving). It was about the right distance, direction and time.

We stopped briefly S of St. John to view the dark menace approaching, then headed E and NE toward HUT to stay ahead (wide-angle photo looking WNW from near Arlington KS). Finally deciding this wasn’t worth going any farther E, we found a protective place and let Stormzilla move over. A sporting goods store on the S edge of HUT was kind enough to let us park under their front porch overhang, right against their doors. It’s not often you get to just stand there well-covered in the lee side of a building, relax, run out now and then to shoot some photos of the oncoming HP/bow Stormzilla, and then let it blast you, no worries.

This was one case where having the I-Phone radar provided assurance we wouldn’t be in a truly dangerous part of it (using the DDC radar, since ICT’s 88d timely fried its antenna motor over an hour before). The apex of the bow passed just to our S, the bookend vortex ( old meso from HP phase) just to our NW and N ( here lit by some anthropogenic glow from the W side of HUT), and we sat in an intermediary channel of estimated tropical storm force (~40-50 kt) WNW winds for about 15 minutes. Power went out there and everywhere else we could see during the maelstrom.

After the wind-whipping, we headed back toward GBD for lodging. A couple miles S of Sterling KS, the solar orb appeared below the razor’s rear edge of the MCS anvil shield and above the top of the far-away deck representing storms in northwest KS. This started up a brief but dazzling double rainbow, its hues warmed across the entire palette thanks to the low sun angle. We stopped to appreciate and photograph it across a deeply golden wheat field foreground, with a strip of green corn in the distance. The wheat looked well-nigh ready for harvest.

Then came dinner in GBD, where we parked next to yet another among many “look at me” chase vehicles hereabouts in the Plains. This one was festooned with Skywarn stickers, assorted “Storm Chaser” decals, a “J2” decal (as if this was one unit of some sort of team…suuuuuure), and an assortment of anemometers, antennae and PVC tubing atop. Upon closer inspection, only one antenna had any wiring leading inside the vehicle; and the anemometers and tubing were wired up to absolutely nothing. Posers. The large stencils on both sides of the rear windows for a local janitorial service cinched the deal. Yep, we found none other than the Janitor Chasers — keeping you safe and clean!

We ended the evening watching and photographing mainly in-cloud lightning and occasional LTGCA filaments from a band of elevated storms that formed just south of town (and later moved N). It was a neat show, as seen from the open field behind the GBD Wal-Mart. [Mr. Jewell knows exactly where this is.]

Be advised, if you must travel through GBD anytime soon, the main E-W route is torn all to hell, and down to one abominably rough lane each way, for about 1/2 mile W of downtown. Keep your windows up too, for the long puddles in the adjoining swales of construction mud smell like the bowl of a bus station commode. But our lodging was good, and cheap (<$50 again), and that line of elevated cores provided a thunderous late-night lullaby.

Northern Burlington at Sunset

July 7, 2009 by · Comments Off on Northern Burlington at Sunset
Filed under: Summary 

14 Jun 9
Eastern CO

SHORT: Saw high-based, outflow dominant storms from the distance in central Colorado, evaded eastward, waited for other storms to form but not long enough. Treated to wonderfully colored sunset at Burlington CO.

LONG:
Elke and I had a good breakfast at the Memories restaurant in Ft. Morgan (highly recommended), before dropping S toward Last Chance to await storm formation possibilities either on the CYS or Palmer Ridges. While sitting on a hilltop between Last Chance and LIC, we saw a very distant Cb explosion to the NNW, which I-Phone radar revealed to be a rapidly evolving supercell near Chugwater. That was out of reach, realistically, and so was the potential afternoon target along the boundary in SW KS.

We waited longer for Front Range and/or Palmer Ridge storms, dropping S to LIC for shade and better data access. While there, a tornado-warned line of storms quickly fired over the DEN metro area (producing that funnel near downtown and Coors Field). I was disinclined to run immediately after that activity, given its linear and likely high-based character.

We kept waiting at LIC for closer development, which did happen to our W and SW. Alas, it was linear too! Still no photos for the day yet…the activity was distant, but I already could see a shelf cloud emerging through some mild haze WNW-SE of us. I envisioned an unfriendly wall of outflow surging E across central and eastern CO, so we threw in the towel on active chasing for the day, perhaps a little too soon.

We arrived at ITR, got a nice and cheap motel room, and ate dinner at the slow and overpriced steakhouse there (not recommended!). We clung to hope for at least an interesting, shelfy sunset. Meanwhile a couple of brief supercells appeared near the tail end of the line before being munched by the meso-beta scale cold pool (these were the storms observed by BillR, MattC and MikeU).

Even the linear MCS appeared to weaken as it headed toward us, but we went to the N side of town to watch it roll past anyway. The sky was remarkably hazy for eastern CO, but once the gust front hit, the view cleared a good deal. A line-echo wave pattern (LEWP), with a brief and embedded supercell to our N, sent a rear-flank augmentation overhead just in time for the setting sun to shine through its precip curtains, opening up a brief bu dazzling splash of warm coloration in the rain curtains.

As the reds began to fade, the blues deepened in the nooks and crannies of the overhead shelf cloud’s turbulent underbelly, compelling a wide angle shot of the beautiful and unusual scene. It was a fantastic way to close out what had been a rather uninspiring storm day.

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