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. Forecasters are warning there’s more uncertainty than usual about where the storm could go once it’s in the Gulf of Mexico midweek.

Tropical Storm Rafael slipped by western Jamaica en route to the Cayman Islands and was expected to strengthen into a hurricane Tuesday evening, federal forecasters said.Rafael, which formed Sunday as Potential Tropical Cyclone 18,