North Atlantic Ocean: Tropical Storm Fiona tracking westward early Sept. 16 /update 1

Event

Tropical Storm Fiona is tracking westward in the southern North Atlantic Ocean early Sept. 16. As of 05:00 AST, the storm's center of circulation was approximately 425 km (265 miles) east-southeast of the Leeward Islands.

Forecast models indicate the system will strengthen slightly as it tracks west-northwestward and approaches the northern Leeward Islands late Sept. 16. The storm is expected to pass over Guadeloupe early Sept. 17. The system is then expected to strengthen slightly as it continues to track west-northwestward to the south of the Virgin Islands and Puerto Rico Sept. 17-18 before taking a turn to track northwestward and making landfall over the south coast of the Dominican Republic close to Santo Domingo early Set. 19. The storm is then forecast to weaken slightly as it continues to track northwestward over the Dominican Republic Sept. 19, before regaining some strength and moving over or close to the Turks and Caicos Islands early Sept. 21. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of 05:00 AST Sept. 16, authorities have issued tropical storm warnings and watches for the following locations:

Tropical Storm Warning

• Antigua, Barbuda, St. Kitts, Nevis, Montserrat, and Anguilla

• Saba and St. Eustatius

• St. Maarten

• Guadeloupe, St. Barthelemy, and St. Martin

Tropical Storm Watch

• Puerto Rico, including Vieques and Culebra

• U.S. Virgin Islands

• British Virgin Islands

Officials could issue new warnings and/or watches in response to the developing system in the coming hours.

Forecast models indicate rainfall accumulations of 7.5-15 cm (3-6 inches) across the Leeward Islands; 10-15 cm (4-6 inches) with localized maximums of 25 cm (10 inches) across the British and US Virgin Islands and Puerto Rico; and 10-20 cm (4-8 inches) with localized maximums of 38 cm (15 inches) in eastern parts of the Dominican Republic and across the Turks and Caicos Islands. The heavy rainfall could produce considerable flood impacts in the affected areas, including flash and urban flooding as well as landslides over higher terrain. Storm surge causing localized coastal flooding is possible along the coasts of the US Virgin Islands and Puerto Rico Sept. 17-18. Swells generated by Fiona are currently affecting the Leeward Islands and are expected to spread westward to the Virgin Islands and Puerto Rico Sept. 16-17; swells could 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. Localized evacuations, flash flooding, and landslides are possible if weather conditions prove hazardous.

The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.

Advice

Activate contingency plans in areas where officials forecast typhoon or tropical storm conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

US National Hurricane Center