North Atlantic Ocean: Hurricane Tammy tracking west-northwestward in the North Atlantic Ocean east of Barbados as of late Oct. 20 /update 2

Event

Hurricane Tammy is tracking west-northwestward in the North Atlantic Ocean late Oct. 20. As of 23:00 AST, the system's center of circulation was approximately 85 km (55 miles) east of Martinique.

Forecast models indicate that the storm will intensify slightly as it turns to track north-northwestward and makes landfall over Guadeloupe early Oct. 21 and Antigua Island, Antigua and Barbuda, late Oct. 21. The system will then make a close approach to Anguilla late Oct. 21, passing east of the island, before tracking north-northwestward then northeastward away from the Leeward Islands through Oct. 25. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming days.

As of late Oct. 20, authorities have issued the following watches and warnings:

• Hurricane warning: Guadeloupe, Antigua and Barbuda, Montserrat, St. Kitts and Nevis, Anguilla, St. Maarten, St. Martin, and St. Barthelemy

• Hurricane watch: Dominica

• Tropical storm warning: Dominica, Saba, and St. Eustatius

• Tropical storm watch: Martinique

Authorities will likely issue new warnings throughout the system's progression in the coming days. Rainfall totals of up to 10-20 cm (4-8 inches) are likely across the Leeward Islands, 5-10 cm (2-4 inches) across parts of the Windward Islands, and 2.5-5 cm (1-2 inches) over the British and US Virgin Islands into eastern Puerto Rico.

Storm surge could raise water levels by 0.3-0.9 meters (1-3 feet) above normal tide levels near where Tammy tracks across the Leeward Islands. Large and dangerous waves near the coast will accompany the storm surge. Swells generated by Tammy are forecast to affect portions of the Lesser Antilles over the coming days, likely producing life-threatening surf and rip current conditions.

Authorities have established emergency shelters across Leeward and northern Windward islands. FlyMontserrat (5M) canceled all flights the afternoon of Oct. 19-20; the airline stated that flights are likely to resume the afternoon of Oct. 21. Leeward Islands Air Transport (LI) canceled some flights across the Leeward Islands Oct. 20. Caribbean Airlines (BW) canceled two flights between Piarco and Dominica Oct. 20. Pointe-a-Pitre International Airport (PTP) in Guadeloupe and V.C. Bird International Airport (ANU) in Antigua are closed through at least the afternoon of Oct. 22. Ports of entry to St. Kitts and Nevis are closed. Authorities closed all schools across Antigua and Barbuda, Dominica, and Guadeloupe Oct. 20, while all sporting events across Guadeloupe Oct. 20-22 are postponed.

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.

Advice

Activate contingency plans in areas where officials forecast 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