The tropical disturbance in the western Caribbean is still just a broad area of thunderstorms. It has moved all the way up to the Yucatan Peninsula from the Nicaragua/Honduras boarder where it was at this time yesterday. The Hurricane Center is giving it a 20% chance of becoming a tropical cyclone over the next 48 hours.
A look at the visible satellite just before sunset reveals a very unorganized system. It does have a cyclonic or circular shape but there is no circulation visible on the loop. That might just be evidence of a mid level circulation that is trying to work it's way down to the surface.
It does look now like it will get some time over open water in the Bay of Campeche. Judging by it's forward motion west/northwest so far, and by it's current orientation with the Yucatan. That can not be said for certain yet however because we don't know where exactly a surface circulation might be developing. If it is developing over the landmass, or wind shear is pushing on the upper part of the system, the convection may be well displaced from the center of circulation. But at this point it looks like this disturbance will get at least 1 full day over open water in the Bay of Campeche. It is there that it will find an environment very favorable for development.