Amtrak 76
I'm fairly certain that this is the southbound Palmetto, running about 4 hrs late. The only other train it could be is the Southbound Silver Star, but they would be running about 1.5 hours early. This is soon after sunrise and a bit too early for the Silver Star, so hence the late Palmetto. The 2 units also is a clue that it is the Palmetto. I was surprised by the appearance of the train nonetheless, since they should have been through here in the middle of the night.