Finally caught the shelf cloud on the back edge

Spent two hours chasing a cell that kept dying on me, and right as I was about to call it, the back edge lit up — this perfect, low shelf cloud rolling over the highway. Got the full sequence on video, but honestly the still I grabbed with my phone is the one I keep looking at. The way the light went gray-green then broke through in that one slit near the horizon — that's the whole reason I do this.