Ivan's intensity decrease is interesting... CIMSS analysis from UW shows that there really isn't much shear over the system... SST and upper-layer heat content is plenty warm, as the storm should be moving over the warm eddy in the northcentral Gulf... The storm's outflow looks very healthy, as it has expanded considerably on the western side. The ONLY negative that I can see, and it seems to really be taking a toll on it, despite the other positives, is dry air getting entrained from the west. This huge chunk of dry air has progressively been getting wrapped into the circulation, with the leading edge now being in the southeast quadrant of the storm. This may have helped cause the northwest convection to almost fall apart late last night and early this morning, and thus the rise in pressure from 915-something to 939mb on the latest recon fix. Odd that max winds have stayed the same despite about 15-20mb pressure rise... Whatever the case, I'm think that dry air entrainment would continue given the pool of dry air to the west... There was recently a convective burst on the west side of the eye, so who knows.... The nice long "feeder band" that existed yesterday south of the storm (extending from the eastern side to the Yucatan) is now gone / evaporated, and there's signs that a "river" of dry air may work its way to the eye, which would definately weaken...
