Why is there such variation in annual rainfall on Dominica?
Located in the tropics at 15° 12″ N to 15°39’N and 61°14 to W 61°29 W Dominica is affected by prevailing easterly trade winds bringing moisture from the Atlantic Ocean. As the moist winds first strike the windward eastern coast of the island , they rise up the sides of Dominica’s high volcanic mountains. With increasing altitude, the air cools, and the water vapor it holds condenses to create clouds and rain. This influence of high mountains, to produce precipitation from the air that crosses them, is called the orographic effect. Dominica has plenty of high mountains to capture rain. Four peaks are over 4000 ft. above sea level: Diablotin (4,747 ft.), Trois Pitons (4550 ft.), Watt (4017 ft.) and Macaque (4006 ft.), while seven others climb to over 2000 ft. None of Dominica’s mountain summits are more than 5-miles from the sea. Yet, on the leeward, western coast of the island, a rain shadow results in locations on the sides of mountains where dry winds (that have already dropped their
