Earl has really taken a beating from the Saharan Air Layer - and it still is. At 26/16Z the NRL PREDICT Project Team had Earl at 15.3N 37.2W moving to the west and at 17Z the position was 15.3N 37.5W with a central pressure of 1010MB, i..e., at the moment, from their perspective, Earl is on life support. Until you have a halfway stable centerpoint, early upgrades can create track variability problems - and we are seeing some of that. In the past few hours the overall structure is showing signs of improvement.
ED