Domiciles don't follow the pattern of the airlines. Many pilots find a nice area in a small town and get comfortable. There is no real 'hub' where all the junior pilots go.

I can tell you that according to JSFirm.com (hint hint), there are openings in NC and Memphis.

I've seen a list of domiciles somewhere. I'll try to remember as many as I can.
Tallahassee, JAX, MCO, VRB, FLL, MEM, IND?, P.R. (San Juan and BQN), EYW, Nashville, CHA, a couple in WV and NC. I'm probably missing about 8 more.

CE