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,

A tropical disturbance in the Caribbean Sea, now known as Potential Tropical Cyclone 18, is likely to become Tropical Storm Rafael by Monday and is forecast to become a hurricane later this week, the National Hurricane Center said Sunday night.

National Hurricane Center forecasters said a disturbance in the Caribbean Sea has an 80% chance of forming into a tropical depression or storm within the next two days.