Yeah, this is where I can admit that this is way beyond my pay grade and that real mets are on a whole nother level thats basically magic. Though from trying to piece together what I can understand and the SPC analysis page you're basically saying that the primary max stripe is driven by the 700-500mb FGEN (as it overlaps with DGZ better) and strong 850mb FGEN and this setups somewhere in Central VA. Meanwhile NOVA and the like are displaced from the higher level FGEN and will use the 850mb instead. While I don't understand the math or physics behind it should I generally assume the 700-500 FGEN will just progress along with the wind barbs (which does seem to place it oddly northward to even fringe me?)
Oh, and while I'm annoying you I'm targeting around 3:30 start of my Jebwalk lmk if that checks out.