AWE457 KDFW to KPHX Route on 12/1/14

I was looking at US Airways 457 flight this morning and saw the large course deviation over West Texas. No sign of weather on that part of the route or at KPHX. According to the dotted line, it looks like that was the planned route. Does anyone know the reason for the detour? I see the flight would have crossed the Talon MOA, but the detour went a lot farther south.

Probably for spacing into PHX.