Leeward Islands: Tropical Storm Ernesto tracking west-northwestward through the Leeward Islands as of Aug. 13 /update 3

Tropical Storm Ernesto is tracking west-northwestward over the Leeward Islands Aug. 13, having made landfall over Guadepupe early Aug. 13. As of 11:00 AST, the system's center of circulation was approximately 250 km (155 miles) east-southeast of St. Croix, US Virgin Islands.

Forecast models indicate that the storm will strengthen as it tracks northwestward and makes another landfall over St. Thomas Island, US Virgin Islands, late Aug. 13. The storm is then expected to strengthen into a Category 1 hurricane as it tracks northwestward and then northward away from the Greater Antilles Aug. 14-early Aug. 15. The storm is likely to strengthen further into a Category 2 hurricane as it tracks northeastward across the Sargasso Sea region of the North Atlantic Ocean Aug. 15-early Aug. 17, before turning to track north-northeastward and passing close to the west of Bermuda Aug. 17. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming days.

As of Aug. 13, authorities have issued the following watches and warnings:

Hurricane Watch

• US Virgin Islands

• British Virgin Islands

• Vieques and Culebra

Tropical Storm Warnings

• Guadeloupe

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

• St. Martin and St. Barthelemy

• Sint Maarten

• British Virgin Islands

• US Virgin Islands

• Puerto Rico

• Vieques

• Culebra

Authorities will likely issue new warnings throughout the system's progression in the coming days. Tropical storm conditions are occurring over parts of the warning area for the Leeward Islands and will spread over the Virgin Islands and Puerto Rico by the evening of Aug. 13. Hurricane conditions are possible in the watch areas late Aug. 13-early Aug. 14.

The system is forecast to produce total rainfall accumulations of 10-15 cm (4-6 inches) over parts of the Leeward Islands from Guadeloupe to Dominica and across the Virgin Islands. Totals of 15-20 cm (6-8 inches) are expected over southeastern Puerto Rico, with maximum amounts of 25 cm (10 inches), as well as 5-10 cm (2-4 inches) across northwestern Puerto Rico.

Storm surge may raise water levels by as much as 0.3-0.9 meters (1-3 feet) above ground level along the eastern coast of Puerto Rico from San Juan to Guayama, including the islands of Culebra and Vieques, and in the British Virgin Islands and US Virgin Islands, including St. Thomas, St. John, and St. Croix. Swells generated by the system are affecting portions of the Leeward Islands and Virgin Islands and will reach Puerto Rico late Aug. 13; these swells are likely to produce life-threatening surf and rip current conditions.

Authorities in Guadeloupe placed the island on red alert (the highest level on a three-tier scale) for heavy rainfall and thunderstorms and orange alert for rough seas from late Aug. 12. Several roads across the island were closed from late Aug. 12, and the Val Ferry company suspended sailings between Pointe-a-Pitre and Marie-Galante Aug, 13-14. At least 14 shelters were made available for people across Guadeloupe from late Aug. 12. The V.C. Bird International Airport (ANU) in Antigua is closed and scheduled to reopen the afternoon of Aug. 13, while the Princess Juliana International Airport (SXM) in St. Maarten is closed early Aug. 13-early Aug. 14. Saba has closed the Juancho E. Yrausquin Airport (SAB) through at least Aug. 13 and canceled all ferry services Aug. 13-15. Motorists are advised to avoid traveling to Fort Bay Aug. 13 due to the risk of flash flooding and landslides. John A. Osborne Airport (MNI) in Montserrat is closed until further notice and Robert L. Bradshaw Airport (RLB) in St. Kitt's and Nevis is closed through early Aug. 14. Clayton J. Lloyd International Airport (AXA) in Anguilla is closed and port and ferry services have been suspended as of Aug. 13. Authorities in Puerto Rico have warned that power outages are likely due to the fragile state of the power grid. Schools have been closed across parts of the region, including Puerto Rico, Sint Martin, and the Virgin Islands. Government offices in Montserrat, Saba, and St Kitts and Nevis are closed Aug. 13.

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.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding may increase the incidence of 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.