1. We all know that there's dry air around the western side of Irene and that mid-level shear from the north is allowing dry air into the system. This is really a result of flow from an anticyclonic rotation over the Caribbean. Two anticyclones (one over the southeast US is upper level and has been weakening) exist, and the Caribbean seems to be developing. Therefore, some shear will continue to impact Irene, and dry air will become an issue; although, Irene will nonetheless likely become a tropical storm.
2. There are two upper level lows that could potentially introduce some upper level shear to Irene. Both lows are rather small systems: one spins over the western Atl. off the SE coast, and the other is south of Irene. The latter especially, could cause a few problems in the short term, as flow from the south at the upper levels and flow from the north at the mid-levels would cause some directional vertical shear. Of course, the low remains weak, and flow into Irene is not currently strong. Additionally, Irene will be moving out of the influence of that ULL within a couple of days. As for the one in the western Atl., it is relatively weak, and ridging is expected to build.
Just a couple of things to think about. Now I'll sit back here and wait for 18Z, which should be soon.
Scott
