We are arriving this week also for the first time to AC but have travelled fairly extensively throughout the rest of the Caribbean and have found long-term forecasts(past 24 hours) to be pretty useless. For sure they are usually wrong especially as you get further south (away from the cold front influence near the states). Tradewinds being what they are usually mean a shower can happen anytime, anyplace. Gotta love those northeasterly winds. Plan ahead no further than that 24 hours and you will not be disappointed. Can't wait, dry or wet!! Like that hydromet site, not bad.