Caribbean Sea: Tropical Storm Fred tracking northwestwards in the Caribbean Sea Aug. 10 /update 2

Event

Tropical Storm Fred is tracking northwestward in the Caribbean Sea early Aug. 11. As of 23:00 AST Aug. 10, the storm's center of circulation was approximately 70 km (45 miles) south-southwest of Ponce, Puerto Rico. Forecast models indicate the system will make landfall as a tropical storm south of Punta Cana, Dominican Republic, the morning of Aug. 11. After landfall, Fred is likely to track northwestwards along the Dominican Republic's northern coast before entering the North Atlantic Ocean; a close approach to the southern Turks and Caicos Islands is likely early Aug. 12. The system will probably continue tracking northwestwards off the northern coast of Cuba through Aug. 13. Fred is forecast to pass east of Marathon, Florida State, US, early 14, before entering the Gulf of Mexico and turning to track northwards off the western coast of Florida through Aug. 15.

Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories
As of 23:00 AST Aug. 10, the following warnings and watches are in effect:

• Tropical Storm Warning: Puerto Rico, including Culebra and Vieques; US Virgin Islands; the Dominican Republic, south coast from Punta Palenque eastward, as well as on the north coast from Cabo Frances Viejo eastward

• Tropical Storm Watch: The Dominican Republic, on the north coast from Cabo Frances Viejo to the Dominican Republic/Haiti border; Haiti, from the northern border with the Dominican Republic to Gonaives; Turks and Caicos; southeastern Bahamas

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

Hazardous Conditions
The storm will likely bring heavy rainfall, strong winds, and rough seas to coastal areas in the Caribbean through at least Aug. 12. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Forecast models indicate 5-10 cm (2-4 inches) of rainfall are likely over portions of the Leeward Islands, Virgin Islands, Puerto Rico, and the Dominican Republic. Models also indicate 1.5-8 cm (1-3 inches) of rainfall over Haiti, the Turks and Caicos Islands, eastern Bahamas, and eastern Cuba through at least Aug. 12. Torrential precipitation could trigger flash floods and mudslides.

Prolonged sea swells and storm surge generated by the system may result in coastal flooding. Persistent onshore flow could make it difficult for the surge to recede and for water levels to decrease in coastal river catchments. In addition to the heavy rain, flooding, and storm surge, the storm could produce damaging wind gusts, resulting in power outages due to fallen trees and toppled utility lines.

Transport
In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions through at least Aug. 12 in areas impacted by the system. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.

Advice

Activate contingency plans in areas where officials forecast adverse conditions. Heed all evacuation orders. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high 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 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 days. Keep any necessary medications in a waterproof container.

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
National Weather Service
Cuba Instituto de Meteorologia (Spanish)
Dominican Republic Oficina Nacional de Meteorologia (Spanish)
Dominica Meteorological Service
Haiti Centre national de meteorologie (French)
Meteo-France (French)