I've been watching the tropical wave during this time frame for the last several days due to the rain potential, and the GFS has slowly trended towards this North Caribbean Wave/Central American Gyre dance that consolidates in the Caribbean instead of the East Pacific. The climate always favors the East PAC this time of year, but I think the GFS has been sensing better dynamics and upper level environment in the Western Caribbean. The 200-400Mb Q-Div, Stream Function Map illustrates a much better convective pattern over the Caribbean for tropical cyclone consolidation, and that area just so happens to be an area with rapidly warming SSTs that will be just to the SE of what remains of in the Gulf from our cut-off low that moves out over the next couple days. It creates one of those mini-troughs under a high pressure in the Gulf that keeps lower pressures in the Western Caribbean.
Needless to say, the May 19-24 period has my attention.
Look at the GIF from 84-150 Hours. You see the trough in the Gulf become the catalyst for convection and lower pressures in the West Caribbean with the convergence zone setting between it and the Upper Level Ridge, and then you see the excellent divergence at the end when the Ridge moves into the area. Later on another shortwave trough forms in the Gulf, and we get one of the early-season hybrid cyclone with a lopsided rain-shield. You can see the upper level energy digging under the system. On the Relative Humidity Map, the upper level energy is also accompanied by dry air that wraps around the system.