Rafael will make a landfall in Cuba as a major Category 3 hurricane, but it will weaken considerably as it moves into the Gulf of Mexico.

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.

Tropical Storm Rafael formed in the Caribbean on Monday, a storm that's predicted to intensify into a hurricane and threaten the Gulf Coast this weekend.