Fun with Small Nebraska Panhandle Supercells

July 14, 2010 by · Comments Off on Fun with Small Nebraska Panhandle Supercells
Filed under: Uncategorized 

Harrison-Gering NE, 19 Jun 10

SHORT: Intercepted 3 nontornadic supercells in Nebraska Panhandle, one after dark near BFF.

LONG: A cold front had swept out of the Dakotas following our last storm intercept day. That stabilized the air mass for awhile and gave a couple of non-chase days for laundry, sightseeing, relaxed travel SW toward an eventual central High Plains target area, and photographing abandoned buildings of various kinds over the Dakotas and western Nebraska: an old schoolhouse, a long-disused, small-town rail station,a barn, the back door of another barn, a mostly intact farmhouse, and a gradually collapsing old house looking in and from without. Elke and I hadn’t been back in the Dakotas for a few years; and while storms beckoned us away, it was great to see the northern Plains again, especially in such a verdant, moist state.

The front’s trailing remnants stalled across the central High Plains beneath favorable mid-upper flow for supercells, while easterly and southeasterly flow to its N would yield decent low-level hodographs. A textbook, multi-day, central Great Plains upslope pattern was setting up, and we had time to participate before the chase season closed out. The main concern on this day was a lack of more robust moisture, but I wasn’t concerned much about whether we would see a storm form, given favorable upslope flow into the higher terrain of eastern Wyoming. We left PIR by mid-morning, targeting the Wyoming/Nebraska border region, with a short venture into the whimsical (but fun) tourist trap of Wall Drug.

As we left Wall Drug, convective towers bubbled over the Black Hills, but struggled amidst the lack of moisture. Moist advection started to solve that problem by the time we got down to around Harrison NE, with a discrete storm erupting to our SW over eastern WY and a short line of some overshooting cells to our NW (closeness exaggerated in the zoom view) across northeast WY, W of the Black Hills. Although both eventually would yield supercells, we went for the cleaner, more moist target to the SW.

We found a one-lane dirt road between Agate Fossil Beds and Mitchell, off NE-29 — no crowds, no traffic, nothing but us, a vast rolling prairie, a storm organizing into a slowly moving LP supercell, and dozens of different bird species joyously singing across the mild breezes.

The chase season to date, and the vacation in particular, had featured lots of driving and moderately- to fast-moving storms. This was a most welcome relief! We stayed there for nearly an hour, just enjoying the peace and solitude, punctuated only with an occasional rumble of thunder from the small, high-based supercell. It didn’t matter at all that this storm likely could never produce a tornado. The soothing salve of the Great Plains in springtime worked its rejuvenating magic on us, and we experienced the most pure, relaxing enjoyment in the face of a storm all season so far. It was a deep-tissue massage for the soul, a reconnection with why we’re out there to begin with.

I also, finally, had a chance to set up our new HD video camera on a tripod, and let it stand there and roll (our first video shooting in several years). [I eventually will construct some time lapses from this footage.] We had received this as a gift shortly before leaving on our trip, and I hadn’t really had a chance to learn how to use it right, amidst all the more active chasing we had done so far. The main intent of this video camera will be to shoot HD time lapses for our own enjoyment and perhaps uploading online; but first priority will be still photography. In this case, our video will feature a chorus of birds in stereo, the breeze, and an approaching storm.

As the first supercell grew more feeble, another small storm erupted very nearby to its S (and our SW), upon which I re-aimed the video and still cameras. This wide-angle shot shows both cumulonimbi at once, and illustrates how neighborly they were. It’s as if one was asking the other, “Would you like to come in and sit a spell? I’ve made some fresh lllllll-lemonade!” (quote [tm] Ryan Jewell). Instead, the northern storm shriveled to vaporous oblivion, leaving the southern one to spin along for a little while NW-N of Mitchell (and by the time of this shot, SSW of us). We finally decided to head S before the storm crossed NE-29, reserving a motel in the BFF suburb of Gering (which wasn’t easy due to all the hail-claim adjusters in town), packing the tripods, and beating the thin hail core across the road. This second supercell soon raised its base and weakened (view looking NE from a few miles E of Mitchell). It was time for some supper in nearby BFF.

As we dined, convection began popping up all around, almost at random, as if a pleasurable rash. Most of it was weak and inconsequential. One storm, however, took good root and became dominant to our WSW. We had some trouble finding the place of lodging we had reserved in Gering (in a neighborhood just W of downtown, but also just a few blocks from the entrance to Scotts Bluff National Monument, as it turned out to our good fortune). After we checked in, we headed over the hill S of the bluff to watch the now-weakening storm move in from the W. Its lightning slowed down dramatically as we set up tripods (of course), but not before one spectacular spark sliced through the twilight sky beneath for sloping base of the forward-flank anvil area. We also enjoyed seeing the apparently dying supercell’s remains float overhead beneath the moonlight, then headed back to our room.

While we were inside, unpacking and unwinding, I noticed lightning activity picking up outside. Another storm? No…after we gave up on it, the supercell rejuvenated and drifted just to our N over BFF, sparking anew from within! Out the door and right back up the hill we went, this time on its E side, to watch the spectacle. Once again, as we got set up, it weakened, but not before producing some nice intracloud flashes around a moonlit main updraft tower that was drying up from below.

I didn’t think to bring the new camcorder back out, and hadn’t yet tried the video functions of the 5DM2 still camera. So, instead, here’s a poor-man’s time lapse I constructed of still photos of the weakening storm moving away from BFF, where it had dumped hail up to baseball size. More work for those hotel-hogging insurance adjusters!

White Buffalo, White Tornado

July 10, 2010 by · Comments Off on White Buffalo, White Tornado
Filed under: Summary 

Glenfield ND to Crookston MN, 17 Jun 10

SHORT: Intercepted a string of mini-supercells across eastern ND into NW MN, with several funnels and one confirmed tornado.

LONG: We had arrived in PIR late the night before — tired, frustrated and hungry after being stonewalled on the wrong side of the Dupree storm, and took awhile to get to sleep. Somehow we still awoke well-rested and ready to head farther NE to this day’s most preferred target area — west of the trees in the wide-open flatlands of eastern ND. While big supercells and tornadoes certainly seemed possible in central MN, it was no closer, with more impediments to viewing from trees and hills. So instead of what was “synoptically evident”, we decided to play the alternative target just NE of where the arc of fast-moving, cold-core supercells presumably would fire, the strategy being to wait for those storms to mature. We also were hoping for enough separation between such storms for a “picket fence” intercept strategy — whereby the observer find a good road aligned perpendicular to expected storm motion, lets one pass, moves E, watches the next pass, and so forth. That was the ideal.

The storms themselves had slightly different ideas.

After heading to ABR to meet up with the late-breakfast devouring “3 Dudes and 2 Dogs” chase team, we all headed N toward JMS, our first sojourn into North Dakota in several years. Surface winds in the narrow warm sector were roaring from the SE, the cumuli above roaring S to N, and higher clouds SW-NE, visually sculpting a mighty fine deep-layer shear pattern ideally suited for supercells. An early storm fired NW of JMS, well out of our reach, and raced N, apparently producing a tornado or two despite being N of the warm front. Storms about to fire near us, along the nose of the dry punch, and just S of the warm front, would have just as much shear and more instability to work with. Optimism ran high, despite the previous day’s misfortunes (the 3 Dudes and 2 Dogs had arrived at the Dupree storm on the right side, but too late).

As we fueled in JMS, an arc of towers went up S through SW of us on that hybrid dryline/cold front, just as anticipated. We initially headed E of torn, but changed our minds about using I-94 as the picket road, and backtracked to get NNW on US-218 to Carrington. In doing so, we all saw the beautiful albino bison White Cloud, start attraction of the Buffalo Museum there at JMS. From Carrington, we turned E on ND-200 toward Glenfield, to allow storms their maturation time. While waiting, I whipped out the shovel and grabbed a couple of bucketfuls of North Dakota’s richest, deep-black glacial soil for use in my vegetable garden. The air was ridiculously moist — dew points well into the 70s F — with high RH thanks to the cooling from deepening anvil shadows produced by the oncoming convective arc. I remarked to the Dudes that it smelled like the ocean outside, and for good reason: just as everywhere else we had been since the Texas Panhandle, fields were saturated and often ponded, with large areas of prairie farmland under shallow, standing water.

This also created an ideal setting for massive clouds of voracious mosquitoes. In dense hordes, they rose from the inundated fields with one aspiration — sucking all possible blood out of unprotected storm observers. These specimens were quite large and rather slow-moving too, easy to snatch by hand and crush, unlike the zippy little culexes and Asian tiger mosquitoes we’re used to down here. As we watched the storms approach, Elke and the Dudes saw the pests banging against windows and windshields of our parked vehicles and stayed inside, not wishing to sacrifice gallons of Type A. I remained outside the entire time, and got bit…not a single time! The SE and E gradient wind, in whose gusts I had trouble maintaining balance, was so strong that it blew the mosquitoes off and past me before they had a chance to bite. Imagine you’re the “skeeter”. You see this huge host with abundant food supply, big areas of exposed skin on arms, face and neck, try to land, and…next thing you know, you’re in the air again, rocketing away from that delicious-looking host despite your fastest wing beats in that direction. I loved the concept, and relished the rare experience of laughing at the stream of hundreds upon hundreds of the pests as they tried in vain to attack me.

Meanwhile the arc of convection was headed NNE at us, maturing, and growing too much, with too many storms. Each cell had very little separation from the next on radar, leaving only a needle’s-eye of viewing opportunity into its mesocyclonic region. Each also was exhibiting enough rotation to be tornado-warned, and several of them produced funnels — some we saw, some we didn’t. We had our first good view of one of the mini-supercells’ updraft areas just W of Glenfield. It rapidly approached from the SW, and as it got to within a few miles, maintained a well-defined clear slot and ragged base with occasional areas of rotation. That was all it could do before getting rain-wrapped (looking WSW at a N-moving storm with meso on its SE side). As we leapfrogged E on ND-200, each successive storm farther E rained into the inflow of the previous, and also slowed us some with portions of its forward-flank core. The storms were translating so fast that these cores were unavoidable, but at least they didn’t contain much hail.

A few of the updrafts, occupying very narrow gap areas between cells, produced small, short-lived funnels — some so quick to develop and dissipate that there wasn’t time to stop and shoot, or even to raise a camera and shoot if stopped. Cloud-base motions in the updraft areas, even without funnels, were extremely wild and chaotic, with little in the way of well-defined structure. Zigzagging mostly E but sometimes N, we did manage to stop at one storm gap between Hatton and Reynolds where two small, adjacent but visually separated updraft areas each produced funnels at the same time, and we did manage to get photos (looking SW and looking SSE, both less than a mile away and moving fast toward the N). In fact, look closely at the left upper edge of the photo of the first funnel, and you’ll see the second (unintended). Both also dissipated quickly after rapid, corkscrewing contortions, with no evidence of ground circulation beneath.

As we crossed the river into Minnesota, S of GFK, the storm arc finally got ahead of us, and the storm observing was obviously about to end. We parked 1/2-mile S of the intersection of MN-9 and a county road headed S toward Eldred, 3 SSE of Fisher, to watch assorted small updraft areas all along the backside of the arc as they hurtled away from us. In this wide-angle shot, looking N, note the small, high-based funnel above and to the left of the road, but also, the ragged little updraft to the right of the road. These updraft areas were just a small part of a string of them extending up into a really fascinating deck of undular “warm advection” clouds along the S side of the storm arc.

As that anemic-looking updraft area moved NNE of us, its rotation tightened markedly, and a funnel appeared beneath. By this image, at 1754 CDT, we were pretty confident that it was a tornado; and later independent corroboration confirmed such. The condensation funnel became fuzzy and somewhat rain-wrapped, but reappeared as a ghostly, front-lit and more obvious tornado, its estimated location ~2 E of Fisher. We had seen a white buffalo and a white tornado in the same day! I tried to call this in to GFK, but as happened an annoying number of times this year while watching a tornado, I found “No Service” on my phone’s indicator. Fortunately, I was able to get the delayed report to them from a later fuel stop in East Grand Forks.

We gave up the hunt N of Crookston on US-75, shortly after passing a mileage sign that read, “Canada 93”. That’s when an OK resident knows he’s really far N, and a long way from home. That night, swimming in a hotel’s indoor pool at 11 p.m. with twilight visible outside, was a different experience!

All of us had a good, celebratory steak dinner at Al’s in Grand Forks. The Dudes and Dogs had to be in OKC day after next, and headed S to FSD for the night; we stayed in GFK and had a nice visit to the NWS office at GFK the next morning.

The Agony of the Unseen

July 9, 2010 by · Comments Off on The Agony of the Unseen
Filed under: Summary 

Faith SD, 16 Jun 10

SHORT: Observed lifespan of pretty Faith SD supercell, then attempted unsuccessfully to intercept Dupree storm, whose most dangerous (hook) part and its flooding blocked the only access for 50 miles. Missed most of its tornadoes as a result.

LONG: After the successful intercept of a tornadic supercell on the 13th, from the Texas Panhandle to Kansas, Elke and I wandered N for some much-anticipated landscape and storm action on the northern Plains. We hadn’t been in the Dakotas more than briefly in a few years, and missed the area hugely. We were eager to return both to a favorable pattern for storms up in those parts, and to the unrivaled Great Plains scenery.

On the way up, we had a pleasant two-day drive, stopping occasionally for abandoned-farm or flooded-field photography. That was followed by a splendid dinner on Hot Springs SD and a stay at some reasonably priced cabins overlooking town. We landed in the same cabins we stayed in with the kids 8 years prior, then headed out for late-afternoon photography of the muscular landscape (another shot) of nearby Wind Cave National Park and the muscular bulk of the buffaloes that inhabit it.

The next morning, we had a choice of two potential targets awaiting us on the other side of the Black Hills:

    1. a warm front somewhere NE of RAP, an area of very strong low-level moisture and shear but somewhat weaker winds aloft, where several models consistently broke the cap, or

    2. a triple-point play closer to the SD-MT border, in a more dependable initiation regime, stronger deep-layer winds, but weaker low-level hodographs.

In easy reach of both, I pondered the situation while we spent the morning wandering past the park’s buffaloes again, and up into the rain-soaked, beautifully verdant landscapes of the Black Hills. We had time to travel the tortuous highway traversing the wondrous Cathedral Spires and Needles area, including its one-lane tunnels that left about 4 inches to spare on either side of my vehicle.

As we fueled up in RAP, towers began to deepen and become surface-based along the warm front to our NNE, S of Faith. The route there is rather indirect; but along the way, we were treated to a fine view across the rolling grasslands as it grew explosively into a nascent supercell. Leaving the I-90 area, we also left cellular coverage, which we wouldn’t have for the rest of the chase. I’m not sure this would have made much of a difference in the end result, given the fairly good visuals on all the storm development; but road logistics would hurt us bad.

We got to a few good viewing positions W of Faith as the first storm grew a young, high-based wall cloud (looking N), then lowered its base somewhat and matured into more of a mothership appearance with tiled convection above. This prompted us to wander NNW of Faith for a closer look. Other towers were growing up and down the warm front on both sides of this supercell, and I feared a new storm would erupt to the SE and dump rain into the inflow. Meanwhile, while we were driving, our storm produced a couple of short-lived funnels from transient, but very tights, areas of cloud-base rotation. A wide-angle view, looking NW, shows the nice structure it had.

One bothersome thing: the supercell was moving more N than E, not rightward, and failing to take advantage of the rich low-level SRH in the warm-frontal zone. Then my fears became reality: rain, from a storm that had erupted to our SE, falling into this storm’s inflow, and rendering it more high-based and stable-looking. We didn’t waffle; the decision came quickly to get back SE into Faith and E, and go after the new storm. After a needed bathroom and fuel stop at Faith, we headed E, seeing that the new storm was S of the only east road for 50 miles, but hoping that (like the previous one) it would have enough of a northward component of translational motion to get N of the road, letting us go to the crossroads options available out of Dupree.

An hour and a half later, we still were waiting for the storm to get off the road, while parked a various spots ~7 E of Faith. The storm had gone stationary at just the wrong place, and I just knew it was spinning like mad, producing tornadoes unseen to us, as South Dakota supercells often do at this time of year when they latch onto high-SRH boundaries. The most dangerous part of the storm (rain- and hail-wrapped mesocyclones), with likely tornado-containing hooks, parked right on the road to our E, while sending surge after surge of very wet, rainy RFDs over and just E of us. We risked driving right into a rain-wrapped tornado, or into floods, if we played “XTREME INSANE” like some storm chasing version of Evel Knievel, and tried to punch the core. No thanks…I rather would live to see my kids again and chase another day.

At about 1815 MDT, early in this rather agonizing series of storm-scale processes, some locals stopped to ask if they should continue E. I told them that I wouldn’t advise it, since a tornado could be buried inside that heavy rain. They did anyway, which makes me wonder what kind of view they had of the spectacle that followed within 3 minutes. we spotted a suspicious lowering in the rain to our ESE, S of the road. It was a wall cloud in an obviously old occlusion several miles W of the main mesocyclone (regular and heavily enhanced zoomimages). A suspicious, conical condensation form appeared in the murk to the right of the trees, moving northward and perhaps even northwestward (regular and heavily enhanced zoomimages).

We were increasingly confident this was a tornado, and kept close eye on it as it appeared to turn toward us! [Pulses of heavy rain precluded camera-safe photography from outside the vehicle, so you’ll have to bear with the raindrops that accumulated between wipings.] Can you spot it now? [(regular and heavily enhanced zoomimages).] We sure could, and it was getting unnerving, with us being buried in the same area of heavy rain as this tornado that was approaching an an uncomfortably oblique angle. We were in the strange position of potentially having to back up fast from a west-northwestward-moving, westward-curving, rain-wrapped tornado on the back side of the storm! The tornado crossed the road (regular and heavily enhanced zoomimages)about 3/4 mile to our E (no damage apparent later…nothing much to damage!), then roped out to our NE and N, the last wisps of rotation being visible in the field around 1/2 mile to our N. I gave the information to a couple of sheriff’s department troopers who pulled up shortly afterward and asked them to relay it to NWS, which apparently didn’t happen, and they proceeded eastward. After that experience, core-punching the succession of hooks to our E was simply not an option.

Eventually, it started to get darker, the storm still parked on the road, floods crossing the low areas between hilltops. We gave up on ever getting ahead of this storm on US-212, and headed back to Faith, hoping to get a room at a friendly-looking motel we had seen there. Alas, power was out to the town (supplied from the east), and locals were talking about all the “big tornadoes” they had heard about “over by Dupree.” This was brutal news, confirmed later by accounts from those few chasers who did risk punching the hooks and didn’t get caught n the floods. Not wanting to risk a powerless motel for the night, we went S and E to Pierre, nearly a 2-hour drive, knowing by then that we missed an amazing show of multiple, photogenic tornadoes, because the storm wasn’t kind enough to park itself just 5 miles farther north.

Why did I write almost as much about the pre-chase as the chase? Simple: This was one of the must frustrating experiences in my entire 26 years of mobile storm observing, bar none. It’s a good thing we had good times on other days before and after, because if this were my only storm attempt of the year, I would have gotten physically ill and perhaps become unbearable for others to be around for awhile. It was that difficult to deal with. And yet, what happened to us wasn’t as frustrating as what some other experienced chasers endured (such as Tony Laubach, who got trapped between two of the floods for hours just ahead of us). Tony, all I can say is…misery loves company, dude…I definitely sympathize! Some days you’re the windshield, some days you’re the bug…

Next Page »