Most chasers who were active on this day (including many who chased Kansas and Colorado the day before like us) targetted the closer target and 'cold core' storms in Nebraska and Missouri and were treated to early initiation....and temperatures in the 50F's!
Our setup down south included an environment with temps in the mid-80's F, 2000-3000 CAPE and bulk wind shear of 30-40kts although the low level shear was poor.
We were hopeful that storms would fire in NE Texas where the chase terrain was much better for chasing and would give us some time on any cells that may go supercellular and before they reached the heavily tree'd areas of SE Oklahoma.
Early cells exploded near Purcell, Ok with impressive updrafts but they moved into the unfavourable chase areas of SE Oklahoma and we let them go, choosing to continue positioning south to the border near Marietta, Ok where we watched storms develop to the southwest in Texas. As the cells moved toward us we observed a storm with LP structure and another cellstorm which produced impressive but short-lived inflow bands and intense lightning near Marietta, Ok.
Cells were now firing to our north and we watched on radar as a severe storm moved very slowly toward Paul's Valley south of Oklahoma City and then backbuilt on the SW flank. This storm was tempting us north and we moved north a little to Ardmore as we discussed our options. Our preferred target to the south had yet to fire despite high supercell parameters but we were worried it may struggle due to an encroaching anvil shield from a massive convective complex that moved through southern Texas earlier that day. We wrestled with the choice of staying or going but eventually we decided to stick with our target and commit south. The navigator for the day who may remain nameless then admitted it was time he 'man'd up' and made a decision. Our choice paid off.
The first storm that took over near Jacksboro, TX bubbled and pulsed for some time before managing to get going in the environment (including a phase where it had a personality crisis between being a left or right mover), and eventually the rotation picked up as the storm was quickly severe and tornado warned as we approached from the NW. We could see the structure from some distance and golfball hail was reported, but storms began to fire much closer to us as well and one of these caught our attention.
The structure on the nearby storm began to rapidly increase and the radar signature improved with inflow banding becoming more prominent and the base lowering. The next phase of the storm NE of Decatur TX involved the rotation of a rather tight base and wallcloud under it that resulted in a "Gonzo" like appendage.
The rotation of this wallcloud was very pronounced and warranted a spotter network report. Unfortunately, the anemic surface shear meant that the relatively high based storms were never going to become tornadic without some unusual interference. Typical of a storm in the LP spectrum, the storm looked fantastic for some time and then almost instantaneously evaporated. We then began to head to the original southern storm once more only to see it evaporate as well (it looks really quirky too, see the remnants of the storm rotate away into nothing after looking healthy minutes before). A new storm to our west near Jacksboro once again looked to be forming and rotating nicely on radar.
As we continued to move west the remnants of the storms behind became quite photogenic which had Crikey hanging out there.
The storm continued to look fantastic but we knew it was a race against time and that the storm would probably do the same thing as the first two.
As expected, as soon as we got into nice position on the storm the daytime heating began to dwindle, and the storm became a weak rotating element of its former self with a very narrow rotating updraft.
As the sun set the colours really picked up and left us with some really nice memories of a good if not slightly tough days chasing, our last for several days as a ridging high pressure pattern resumed.
Stay tuned for around Wednesday the 18th when the convection returns to the plains and the chase continues! Video snippets will be coming as soon as we manage to argue down the footage to a reasonable sample ;).
Feathers and Crikey
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