Rafael is the 17th named storm of the Atlantic hurricane season, and it could become the 11th hurricane. The season lasts until Nov. 30.

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 was rapidly picking up steam on Tuesday afternoon as it chugged toward the Cayman Islands in the Caribbean, and will likely become a hurricane in the next few hours, according to the U.