As Jason alluded to in his post from earlier this morning, focus in the Atlantic basin is slowly turning towards the Western Caribbean. For several days, the various global and mesoscale models have been hinting at some development, whether tropical or subtropical in nature, of a low pressure system in either the Eastern or Western Caribbean (or, in some cases, both). Until the past day or so, most predicted the shear to be prohibitively large for anything significant to occur, especially with this western Caribbean storm.

However, over the past day or so, the models have come into better agreement, focusing on the disturbance in the western Caribbean for potential development. They've also become bullish on developing an upper-level ridge above the storm and carrying it northward into the Gulf of Mexico with whatever comes of the disturbance. With run-to-run consistency developing, it is certainly something to watch.

For now, a trough lies just to the west of the storm, with a strong jet about to enter the region. In about two days' time, however, conditions should become more favorable as the ridge builds in. SSTs are certainly warm enough for development (particularly in the central Gulf & NW Caribbean); the biggest factor should be the trough of low pressure to the west: what will it do in terms of moisture & wind shear? We'll have a better grasp on that problem come Thursday. For now, stay tuned.

As for the type of development: global models are calling for a borderline tropical/hybrid storm to begin with, but the mesoscale models (MM5) are looking for purely tropical development. I'm more inclined to go with them myself. Anything that develops -- or doesn't -- will likely have its sights set on the northern/eastern Gulf coast, depending upon the evolution of the upper-level pattern. Bottom line: keep an eye to the south for the time being.