Above Anvil Cirrus Plume

While out shooting sprites in central Oklahoma, I captured what is likely an above anvil cirrus plume. These features are not often seen clearly from the ground, and are the focus of some fascinating ongoing research! This feature is essentially a wave in the cloud tops. These plumes are generated by a hydraulic jump, a common feature in fluids formed when fast moving fluid enters a region of slow moving fluid. With essentially nowhere to go, the fluid stacks up upon itself, increasing its height. If the flow speed is great enough, the jump can become turbulent and curl back on itself. We see this commonly in streams and rivers where rocks act as a barrier that creates the jump. In the case of what I saw, an overshooting top in the thunderstorm (a dome of clouds that extends higher than the rest) acts as the rock that obstructs flow, and so the winds above the clouds rush down the overshooting top and form a jump.