I actually was heading east to intercept a cell in Bedford county when I noticed a lowering over the southern Roanoke Valley that was vacuuming up scud. I watched it for a while and then decided to continue toward Bedford, but before I had gone a half mile the lowering turned into a full-fledged wall cloud. I stayed put and observed until rain obscured the feature.

Here’s an early closeup of the lowering (inside white oval) sucking up scud: