A disturbance in the Caribbean strengthened Monday afternoon into Tropical Storm Rafael, which is forecast to become a hurricane Tuesday.

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.

Sign up for our Newsletters PTC 18 in the western Caribbean Sea. Potential Tropical Cyclone 18 is a broad area of low pressure in the South Central Caribbean Sea. According to the