After processing and reviewing my non-HD dashcam video from yesterday’s (8/6/14) chase I am declaring the feature that I observed to be a possible funnel. (That’s less definite than a “probable” funnel…) Given the backlighting, the distance, and the haze I couldn’t tell visually if the feature was rotating but speeding it up 8x and watching the entire clip it appears as if rotation was present. It definitely was not just scud.
The photo I posted yesterday of a skinny “rope” was the dissipating phase of the overall feature as seen toward the end of the video clip. Best GPS location I can come up with is (37.2154, -79.4355) and I was looking WNW: