Don't be too quick to call that 'all clear' just yet. The narrow ridge to the north of the storm is building and creating some rather significant compression shear from the east over Irene - thus the ragged appearance. The ridge has also extended southwestward toward the southeast U.S. and was evident this afternoon when thunderstorms over the Florida peninsula were shoved to the southwest. In a very real sense, Irene is 'trapped' for the moment. Her northwesterly movement has become more west northwest and a slow westward track is even possible over the weekend. The easterly shear is going to keep intensification in check for awhile and the storm may actually weaken. Another ridge will move offshore on Saturday and intensify the block,so Irene may be stuck in place for a couple of days. Right now I'm not sure exactly where Irene will end up. The 11pm Advisory was simply a continuity forecast so I'm guessing that NHC is having a bit of trouble with this one too.
Cheers,
ED