As advertised, the western Caribbean is becoming much wetter as thunderstorm activity increases over the region east of the Yucatan Peninsula. A broad monsoonal low is rotating over the region with one center over central America and another east of Nicaragua. This latter one may start rotating up to the northwest and could aid in consolidating the area into a tighter low east of the Yucatan this weekend. Given the large nature of the system and land interaction, development will be slow to occur, but with several days to work with before it has to move anywhere, it should be watched carefully.
A trough coming down in 4-5 days over the central-eastern U.S. will be drawing anything sitting near the Yucatan northeastward in the general direction of Florida, making at the very least a heavy tropical rainfall event in the works for them next week. The map I put out yesterday shows a medium-high chance for development in the western Caribbean over the next few days, with an eventual escape northeastward. It should be noted that given the large nature of the system, it may not even have a chance to get very strong at all before being picked up by the trough, but it has enough time to be a cause for concern. Residents in the NW Caribbean and Florida should keep a close eye on the situation.
Half of the models led by the GFS take the low westward into the Bay of Campeche before the trough tries to pick it up, a movement that is not impossible but that seems less likely to me given the aggressive eastward progression of the MJO and the warm water in the Caribbean. A meandering movement with a slow drift northward this weekend and then a quicker northeast escape next week seems most likely to me right now. The ECMWF and UKMET currently support this solution.
We shall see what happens!