May 24, 2021
Statistics
Summary
Dryline/warm front triple point play in northwest Kansas. Targeted Colby for afternoon tornadic supercells. Intercepted supercell south of warm front, which failed to reach front, stalled and died. Retargeted Tail End Charlie storms to the south while northern warm front cells produced. Noted brief dust whirl tornado northwest of Lakin followed by dramatic supercell structure southeast of Lakin.
Crew and Equipment
Chase partners: Jennifer Brindley Ubl, Anton Seimon, Tracie Seimon, Hank Schyma. Equipment: Sony AX100, Canon 60D, Photography courtesy Jennifer Brindley Ubl shooting on a Nikon D4s.
Video
Details
"Day 1 looks like a slam dunk, x marks the spot. Large model agreement on a dryline bulge s of GLD by mid to late afternoon. Expect thunderstorms to form off the nose of strong surface heating, low level lapse rate finger poking into w c KS and track ene. Moisture convergence at the quasi dl triple point has low 60s dews with moderate instability of about 2000 J/kg. Secret sauce params for tubes are all thumbs up with LSI wide open all day, so expect initiation as soon as we get heating and that push, say 20z to 21z. Convergence at the TP yields very strong 3Cape values. Glancing blow from southwesterlies aloft will limit effective shear, but it still looks adequate at 30-40 knots. Turtle recommends being on the play at initiation. There may be an initial landspout play, but slower moving cells in pancake terrain should be easier to work with so there's less fear of being left behind. Given wide open LSI and 3Cape, it's possible for more of a "pop and drop" situation too, despite the synoptic setup not being a high risk tornado play with strong directional shear at the onset. But storm mode is a concern going into the evening, perhaps transitioning into a squidge like we had at the end of yesterday's chase, so prefer hopping on the line sooner rather than later. Expect massive chaser convergence given x marks the spot, but hopefully there is ample room on the nearby grid. Just keep in mind that it'll probably be a muddy mess out there so do not recommend using it for large positioning moves, just crowd spacing and intercept placement.
Secondary targets all look like a compromise in some form. Either further removed from upper level support or with weaker thermodynamics. A good reason to play one is if the primary target gets hosed for some reason by a freak MCS or cold front, or if there is a magical east to west boundary drifting along in the panhandles/sw CO that somebody can find.
Initial target is 15 mi ssw of Colby, KS at 20-21z. Mature supercell by 22-0z. Recommend chasing lead north cell/initial cell coming off the dl bulge. Subsequent cells may be once again caught behind ofb or more of a squidge mode. "
We met the group at a park in Sharon Springs. Storms were already firing to our southeast meaning we’d be behind the ball if we didn’t move soon. We designated a team lead and were rolling. A cell had become dominant and was already taking on supercellular characteristics. The plan was to head back up the northeast highway, get ahead of it, and drop south for the intercept.
Our intercept route had us meandering around in a box, and then clipping the forward flank of the storm. We came out in front of the updraft base. There was already an RFD notch and low level rotation in the base. Yet the storm looked like it wasn’t ready to produce, scruffy and high based. It would probably need a couple more cycles and the enhanced directional shear on the warm front for a real shot at a tornado.
And then the storm started to do something really cool right in front of us. A kink developed in the long straight line gust front. An inflow surge followed, the kink wrapped up and pinched off an occluded updraft. The low level rotation ramped up and then dust appeared at the surface. It lasted mere seconds, but the dust corkscrewed up to meet the rotating base aloft, and then it was blasted to pieces by a strong surge of outflow. It was the briefest, weakest of tornadoes, and yet we had front row seats to the entire tornadogenesis process without even having to move. I was too busy feeling sorry for myself to really enjoy most of the wind up process, and then it was over just like that.
Conclusion
I’d tally a tornado for this chase and got some great structure shots, and yet it still felt like a bust. I had picked a great target that morning and let it get away from me, missing the tornado show of the day, and a potential dataset for our tornado photogrammetry research project. The Selden tornado was rated only EF1, but tracked along and across a highway in dramatic fashion. There were tornado reports only a few miles from my target of 15 ssw of Colby at 21z, and more reports near where we started the day in Colby. Had we simply driven to the target and waited, or even stayed in Colby, we probably would have gotten a tornado shot and continued on to get the Selden tornado. Instead we let ourselves start just ever so slightly out of position, which cascaded into getting lured away from the target warm front play by a sucker storm, and then it was downhill from there.
Lessons Learned
- Play your target tightly, and don’t let a series of small missteps accumulate until you’re out of position for the main play.