It continues to look as if tropical development could be a concern in the western Caribbean beginning as soon as the middle part of this month.
All of the model guidance continues to point to the possibility that we should be looking at the western Caribbean as an area for tropical development by about the weekend of May 17-18.
The GFS model has been the most aggressive with this potential development. The aggressiveness of the GFS model’s forecast should be taken with a lot of skepticism as there is a bias in this model in forecasting erroneous tropical cyclones in the western Caribbean during May into early June. That said, the GFS model does forecast a tropical system to form near the coast of Central America during the weekend of May 17-18 & for it to gradually head northward towards the northwestern Caribbean by about May 21.
While the Canadian and European operational models do not show any sort of tropical development, there are a fair amount of ensemble model members that do show possible tropical development in the southwestern Caribbean during the weekend of May 17-18. Most of the ensemble members that do show development show a track that takes any system to the northeastward towards Jamaica, eastern Cuba and Haiti by May 19-20.
In addition, the European ensemble model guidance does still forecast a 30 percent chance for tropical development in the southwestern Caribbean by the weekend of May 17-18. Also, the longer range European ensemble model guidance is pointing towards a 30-40 percent chance of tropical development in the southwestern Caribbean during the week of May 19 with these 30-40 percent chances continuing through the week of May 26.
Also, the CFS model seems to be pointing towards the possibility of storminess and at least one area of disturbed weather over the western Caribbean during the week of May 19.
Here Are My Thoughts: Based on everything that I have looked at, I do think that there’s definitely the chance for some sort of tropical development to occur in the southwestern Caribbean in the area just north of Panama by the weekend of May 17-18.
One thing that is prominent in the data is the fact that there is likely to be a robust upward motion pulse pushing across the Caribbean by the end of next week through next weekend (May 16-18). This will lead to a favorable background environment for tropical development.
Even though wind shear values across the entire Atlantic into the Caribbean are very unfavorable for tropical development right now, there are signals in the data that suggests that favorable amounts of wind shear will be present over the western Caribbean by next weekend. In fact, it is possible that there could be lower than average wind shear values over the western Caribbean by next weekend.
All-in-all, I think that there is still about a 20 percent chance that we will see some sort of tropical development occur in the southwestern or western Caribbean as soon as next weekend (May 17-18). Any system that does try to form in the southwestern or western Caribbean could be guided from the western Caribbean northeastward towards Cuba, the Bahamas and up near the East Coast of the United States.
This is something that I will continue to keep a close eye on. That said, it’s nothing to be overly concerned about or worried about, for now.
The next tropical weather discussion will be issued on Friday.