Caribbean: Potential Tropical Cyclone 18 tracking northward across Caribbean Sea towards South Carolina, US, as of late Nov. 3

Potential Tropical Cyclone 18 is tracking northward across the Caribbean Sea toward Jamaica late Nov. 3. As of 22:00 EST, the system's center of circulation was approximately 520 km (325 miles) south of Kingston, Jamaica.

Forecast models indicate that the storm will strengthen into a tropical storm over the coming hours before slowly turning to track northwestward and making a close approach to Jamaica early Nov. 5, passing just west of the island. The storm is likely to continue northwestward and make another close approach to the Cayman Islands late Nov. 5, passing east of Grand Cayman, before strengthening into a Category 1 hurricane and making landfall over Isla de la Juventud then Pinar del Rio Province in Cuba early Nov. 6. The system is likely to weaken into a tropical storm as it tracks northwestward across the Gulf of Mexico towards Louisiana, US, through late Nov. 8.

As of late Nov. 3, authorities have issued the following watches and warnings:

• Hurricane Watch: Cayman Islands

• Tropical Storm Warning: Jamaica

Authorities will likely update and extend the coverage of the weather advisories over the coming hours and days as the storm approaches.

Hurricane conditions are possible in the Cayman Islands by late Nov. 5. Tropical storm conditions are expected in Jamaica by late Nov. 4. Heavy rainfall will impact areas of the western Caribbean, with the heaviest rainfall over Jamaica and southern Cuba through Nov. 6. Rainfall totals of 7.5-15 cm (3-6 inches), with locally heavier totals of up to 23 cm (9 inches) are forecast. Flooding could occur over portions of Jamaica and Cuba, with landslides possible. The heavy rainfall will spread north into Florida and adjacent areas of the Southeast United States Nov. 6-10.

Minor coastal flooding is possible in Jamaica Nov. 4 and the Cayman Islands Nov. 5. Swells generated by the system are expected to affect much of the western Caribbean over the coming days. These swells are likely to cause life-threatening surf and rip current conditions.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

Inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.