Tropical Storm Rafael is strengthening over the Caribbean Sea ahead of its arrival in the Gulf of Mexico this week, according to the National Hurricane Center.

ToplineTropical Storm Rafael is expected to strengthen on Tuesday while becoming a hurricane over the western Caribbean as the storm heads northwest toward the Gulf Coast later this week, impacting the Florida Keys and other states,

Potential Tropical Cyclone 18 is likely to gain strength and develop into Tropical Storm Rafael today. The system is headed toward the Gulf of Mexico.