Rafael is strengthening and will likely become a hurricane by Tuesday night as it batters the western Caribbean on the first leg of an uncertain journey toward the US Gulf Coast.

Tropical Storm Rafael is passing south of western Jamaica and is forecast to strengthen into a hurricane possibly by Tuesday evening.Rafael, which formed Sunday and was previously known as Potential Tropical Cyclone 18,

Evacuation orders were issued for some 37,000 Cuban residents Tuesday as the storm strengthens in the Pacific.