Ever wonder why the best deals for the Caribbean occur late summer and fall? Hurricanes!
I would not book a trip to the Caribbean anytime from July to November until a week out. Since these tropical storms move slow, say 15-20 mph, and the general direction of the path can be predicted a few days out, it is best not to risk it by "early birding" a trip months out.
For conditions in the Atlantic and Eastern Pacific visit NOAA.