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.
Colorful Stormy Skies, Day and Night
Southeast Panhandle of TX
12 May 9
SHORT: Mostly multicellular storms observed from Matador to Memphis TX by day, yielding fantastic sunset scenes, then a brilliant and long-lived electrical display after dark.
LONG: My forecast target was the Caprock area somewhere near its prospective intersection wit the warm front, which looked most likely to be along or just S of the latitude if CDS, and N of the latitude of LBB. I wasn’t expecting raging supercells given the weak effective shear and lack of more robust midlevel winds; but I thought we at least had the possibility for brief ones. The very stout cap was a huge concern too, so I also was hoping for a little dollop of good ole Panhandle Magic (As Bobby P has been wont to say, “It’s May, it’s the Panhandle…chase!”).
Elke and I left Norman after a rather late lunch, confident that the capping would hold off initiation in that area until after 1700 CDT. It doesn’t always happen; so I love it when a forecast comes together.
Along the way, we stopped to photograph some abandoned structures, walls constructed of native Cambrian granite cobbles that basked in muted sunlight, surrounded by wheat fields, with the backdrop of the Wichita Mountains for texture. I didn’t stay long to appreciate the scene or do more close-up photography, though. Despite the mid-afternoon sun and stiff breeze, dozens of fat and ravenous mosquitoes swarmed me with a speedy and bloodthirsty attack every bit the equal of their notorious cousins in the Everglades or the Minnesota North Woods.
By the time we approached from the E, as if on cue, turkey towers started bubbling over Turkey TX. Although these attempts didn’t survive, thicker clumps of towers did to their SSW, in Motley County (see towers and flowers). Consider the cap broken! We hung out at some picnic tables in Matador for at least half an hour, eating Allsups burritos, watching assorted other chase vehicles pass through, and waiting for the rather messy, multicellular convection to become better organized. It did, but in a linear sense, and began to accelerate NE toward the CDS-Memphis area.
Off we went the same way, passing right by the same Stitch Ranch entrance that Rich and I used as a staging point for observing the April 29 eastern supercell. Nearby, I stopped to photograph a thick, partly rain-diffused shaft of sunlight beaming through a cloud gap and onto the distant rolling prairie, an orphan of brilliance amidst the stormy shadows.
The messy structures continued until shortly before sunset, when Elke and I decided to move from front to back side of the complex for photographic reasons. We grabbed a quick dinner in Memphis then headed E on TX-256, past some other chasers, to a pleasantly lonely, gravel side road near the Hall/Childress county line.
What a marvelous setting! Warm tones of the low sun painted a brilliant rainbow segment across the deeply bronzed west wall of the storms. The freshly soaked ground gave off that earthy, moist aroma of a formerly dry land newly satisfied. Bird calls of all kinds carried across the cool breezes. Two bobwhite quail carried on a conversation past us as we admired the fiery sunset scene in the western sky; while in the south, varyingly colored low clouds drifted before a canvas of a higher deck with a different hue still (wide angle and somewhat later).
There’s no experience quite like a Great Plains sunset right behind storms. I hope those photos convey at least a small measure of that.
Then came a dazzling display of atmospheric electricity on the back side of the complex, from the southeast Panhandle all the way across southwest Oklahoma and back to Norman. Lightning filaments raced through a mammatus canopy that spread upshear of the complex, giving many storm observers (from us to the V.O.R.T.EX.-2 crews in CDS) a memorable show. We stopped near the TX/OK border to shoot a little of the action, with Elke capturing one of the most crisply defined sets of nighttime mammatus I’ve seen in a photo. This nearly daylight-bright discharge spread overhead and beyond, raising a distinctive, simultaneous crackling noise in some nearby high-voltage power lines. We soon headed home, content to watch occasional flares of electrical brilliance across the rainy night sky.