MIAMI (AP) — A weather system in the southwestern Caribbean is expected to develop and strengthen this week, prompting a tropical storm warning for Jamaica and a hurricane watch for the Cayman Islands to be issued Sunday, the National Hurricane Center in Miami said.

The system could also bring heavy rainfall to Cuba and Florida, as well as the northern Gulf Coast later this week, the center said.

As of 4 p.m. EST Sunday, the system was located about 345 miles (555 kilometers) south of Kingston, Jamaica, with maximum sustained winds of 35 mph (55 kph), the center said. It was moving northeast at 7 mph (11 km/h), with a turn to the north and then to the northwest.

It was expected to become a tropical storm on Monday, with steady strengthening forecast. A tropical storm is defined as having maximum sustained winds of 39 mph (62.8 km/h) to 73 mph (117.5 km/h). Hurricane-force winds are 74 mph (119.1 km/h) and higher.

The disturbance was expected to be near Jamaica by Monday evening and the Cayman Islands on Tuesday and Wednesday, according to the hurricane center, which urged residents of Cuba and the Florida Keys to monitor the storm’s progress. Heavy rainfall will affect the western Caribbean, with totals of 3 to 6 inches (76 to 152 mm) and up to 9 inches (229 mm) locally expected in Jamaica and southern Cuba. Flooding and mudslides are possible in these nations.

Heavy rain will reach Florida and adjacent areas of the southeastern U.S. by midweek to late, the center said.