Fun with Small Nebraska Panhandle Supercells
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!
The “HP Drum” Storm
Delhi/Clinton/Greenfield OK, 12 May 10
SHORT: Observed HP supercell from S of Delhi OK to Clinton area, with some lightning after dark near Greenfield.
LONG:
The main surface cyclone was ejecting northeast over Kansas with a slowly progressive cold front southwestward across NW OK and into the TX Panhandle, intersecting the dryline in the extreme eastern Panhandle. I normally don’t like cold frontal setups such as this for tornadic storms, with upper flow nearly parallel to the front and barely rightward of the dryline. Still, with the boundaries intersecting only a couple of hours to the west, dew points in the mid 60s to near 70 F in the moist sector, and 50-60 kt 500 mb winds aloft, in the eastern Panhandle region in mid May, it’s advisable to chase. The basic ingredients of moisture, instability, lift and shear would be there. The biggest question, of course, would be the relative geometry of kinematic fields and boundaries, offering a dominant tendency for linear storm mode.
Ryan and Corey, whom I had chased with the two prior days, had other obligations on this day of more marginal tornado potential; so I hopped in the truck and headed W on I-40 to await the day’s convection. It was easy to ignore a rapidly-moving, leftward-deviant hailer down by LTS, and wait near W edge of a thick cirrus plume for heating back along the dryline.
Towers kept erupting along the cold front and feeding NE into a backbuilding line, which I preferred not to go after. Storms also were forming off the dryline into SW OK, but almost instantly turned linear as well. Instead of going after either right away, I hung out near Leedey for a spell, shooting around an abandoned homestead while waiting for the convective mess to sort itself out better.
Sometimes linear messes do break up into supercells, and that happened here. The activity to my SW began to knot up into inflections and semi-discrete embedded storms, one showing increasing rotation on the N end near Erick. As I headed down that way, it got tornado-warned, apparently producing a brief one early in that cycle. By the time I got there, the storm was nearly featureless and photographically unworthy, a hopelessly huge cascade of cold rain falling into its inflow from yet another intensifying, embedded supercell farther SW.
I dropped S out of Sayre and intercepted this storm with a big, robust velocity couplet near Delhi, not knowing yet that Mike U and Matt C (who had been hanging out in the eastern Panhandle for a few hours) already had abandoned their initial target, dropped SE, and had seen a brief tornado with it down near Vinson. As this drum-shaped, heavy-precip (HP) monster came into view (24 mm wide angle), a tremendous, frightening and dangerous barrage of CG lightning to its NE (and all around me) reminded me how little lightning we had seen with the tornadic storms the previous two days! It also kept me inside the truck, only briefly opening the window to shoot an occasional photo as the storm churned toward me.
There were good east, southeast and northeast escape options, so I could hold this typically more treacherous viewing position for longer than usual, until either the HP mesocyclone got too close or the hail got too big. If this sucker were to produce a tornado again, the most probable way to see it would have been from within its path to the NE. At one point, it seemed willing! Alas, the feature had far more rising motion than rotation, and devolved into a scuddy tail.
When the nasty part of the storm’s core got close, I zigzagged NE toward OK-152 E of Sayre and took that road to Cordell in incremental fashion, occasionally lurching E to get out of vault hail that started beating on the vehicle before the stones got big enough to cause damage. That’s what was going on as I took this wide-angle shot back toward the mesocyclone, looking SW from a point 8 SSE Elk City. The low-hanging, scuddy area was rotating, but not alarmingly fast, with a clear slot drawing around. That was the best that occlusion process could do, however, and I kept going along 152 to stay ahead of the huge hail that surely made life miserable on some farmsteads soon thereafter.
I was repositioning through a remote area NE of Cordell and E of Bessie, at a relatively distant position, when the storm produced the brief spinup along I-40, and couldn’t see it in the dark murk. After dark, and after the storm go N of I-40, it turned somewhat more leftward again, its propagational component and mesocyclone each weakening with time, while persistent nonsupercellular storms formed on its SW flank. The complex yielded several episodes of CGs (photographs 1, 2, 3) after dark between Greenfield and Watonga before I headed home into the last of the 70s dew points for some time to come.
Thunder on Thunderbird
5 Aug 9
Lake Thunderbird, Norman OK
Either I’ve been out of town, asleep, or at work for most of the best lightning opportunities in Norman this year. Last night, therefore, was a treat. After watching some recorded TV with my kids — namely a special on the Dallas Cowboys’ amazing 1993 season — I heard thunder in the distance. The radar loops showed some elevated storms firing over SW Oklahoma City and east of Lake Thunderbird. Both were sparking nicely by the time I went outside to look, so I tossed the camera bag in the car and headed a few miles over to the lake for some lightning viewing and photography.
My usual setup spot there for storms to the E and SE proved well worthwhile…for a couple of minutes! I only managed to get a handful of shots, one of which I was happy with (above and here), before the storms filled in on top of me. I had to wait out the rain and CGs for about half an hour. Photogenic lightning after that was very sporadic, and hit-and-miss (mostly missed, in my case). Nonetheless, the rain-cooled air refreshed and invigorated me, making the short trek well worthwhile, whatever the lightning photography results. Given our ongoing return to the summertime furnace, my lungs welcomed that cool, moist breeze like my stomach would accept a drink of water after a trek across the burning sands of Sonora.
After getting cored, most of the lightning to the SE and S was in-cloud and in-precip, though I did get a few shots of filamentous aerial discharges and distant CGs across the water. Some sparking and training echoes to the NW and W had me head to the other side of the bay for several shots of distant, core-edge CGs with the tan glow of OKC lights illuminating foreground clouds. Then the storms retreated, and it was time to saddle up and scoot on home.