As was the more likely scenario, surface-based convection has been prohibited by the cap (well, north of I40), as evidenced by the relatively massive subsidence inversion on the 00z LMN sounding. There was NO way you'd get surface-based convection up there looking at that cap. Farther south, however, things were largely uncapped by late afternoon, as the 00z OUN sounding shows essentially no cap in place. However, there wasn't much in the way of forcing down here, save for a small area of convergence near Duncan earlier this evening. It looked like a CB tried to develop in that area, but it quickly dissipated after briefly appearing on Tilt 3-4 radar images and vis sat. Capping must have been a bit stronger to the southwest of OUN, though I can't imagine it would have been too much stronger given that warmer temps that way. Regardless, this event fits with the lesson I learned from 2002 -- you will rarely get convective initiation on the backside of a departing mid-upper level wave/low. I got burned many times in 2002 for that, so I'm pleased I didn't commit to chasing today.