Summary:

Chased southwest OK along the 283 corridor, south of I-40. With timing & diurnal initiation in question, we decided not to chance it further north by Woodward in spite of better shear/helicity & warm advection. Patience paid off as the first-- and only-- BIG supercell before sundown went up literally just 15 miles to our southwest. By 6:00, huge towers started building right in our target area (see this picture)!

Caught up with this huge striated supercell a few miles south/west of Cordell which formed at a humid/thermal air masses boundary intersection. By 2233 (5:33 CDT) surface temperatures were still climbing into the mid-80s, clearly showing a narrow thermal axis. We briefly veered west off the highway to get better visual of the base, and when we stopped the storm had already developed a strong lowering!

Interestingly, I’ve never seen a storm that looked so well organized cycle as many times as this one did, morphing from a surface-based classic supercell to a high-based mothership. Then again, this was Oklahoma!