On caribbean islands with mountains, the windward slopes facing the trade winds force air upward, causing rainfall. as a result, areas immediately to the leeward of the mountains have a microclimate with sparse precipitation called a/an

Areas immediately to the leeward of mountains have a micro-climate with sparse precipitation called a rain shadow. 

As the moist air moves towards the land it hits the side of the mountain, which results in the air moving upward, as this warm moist air is forced up, it cools down and results in rainfall. After the cloud passes over the mountain, the moisture evaporates and a rain shadow forms on the other side.