Aha! For years I thought this was a fat Asilid, perhaps a Diogmites with a killer fungal infection. Now I realize it is a normal Xylophagid. Looks to be Coenomyia ferruginea, compare:


There's only one species in the genus, and it's on a checklist for this state (1), as well as in the North Carolina State University collection, so I think I'm OK on this.

With an abdomen like this, I am thinking it is a female. Size estimated--I remember it being at least medium-sized. (See guide page--I found a reference giving length as 16-18 mm--I guess my memory is not that bad!)