Bit out of my usual patch being from Rendlesham but big black cats are something I follow pretty closely. We get sightings over here in Suffolk fairly regularly and the descriptions are almost always the same - low slung, jet black, bigger than any domestic cat, moves dead quiet.
What got your attention about it, was it the size or the movement? In my experience people who've seen them always mention how they move, theres something about the gait that sticks with people more than anything else.
Would love to hear more detail if you've got it. Anyone else in this thread had sightings in that area before? Wondering if there's a pattern building up around the Blue Ridge.