I just found a great forecast model that illustrates what's happening now to the Gulf loop current; you can find it here. Every 6-11 months, a circular-moving pool of water - a vortex - pinches off from the Gulf loop current and gradually moves westward (this is also a warm pool of water that is watched carefully during hurricane season). As this happens, the main flow of the loop current is suppressed far to the south.. through the FL Straits and up the east coast. Effectively, the loop current cuts off into two distinct streams. As long as the loop current eddy remains south of the Gulf oil slick, it will be essentially impossible for oil to reach the main stream of the loop current and flow toward the Keys. This will not last forever, though, as eventually the eddy will move westward the loop current will become re-established to the north -- the northernmost part very close to the southern part of the oil slick.
Brian
