North Atlantic Ocean: Tropical Storm Elsa tracking west-northwestwards in the southern North Atlantic Ocean July 1 /update 1

Event

Tropical Storm Elsa formed in the southern North Atlantic Ocean July 1. As of 23:00 AST, the storm's center of circulation was approximately 420 km (260 miles) east-southeast of Barbados. Forecast models indicate the system will strengthen slightly and continue tracking west-northwestward, making a close approach to Barbados the morning of July 2. Elsa is forecast to make an initial landfall over Saint Vincent and the Grenadines mid-July 2 before entering the Caribbean Sea. The storm will gradually weaken as it makes a close approach to southwestern Haiti late July 3 and another landfall over southwestern Cuba early July 4. Elsa will likely maintain its intensity and shift northwesterly over Cuba and northerly over the Straits of Florida through late July 5. The system is forecast to enter the Gulf of Mexico late July 5 and track northerly off the western coasts of Florida, US, through at least July 6. 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 July 1, the following warnings and watches are in effect:

• Tropical Storm Warning: Barbados, Martinique, Saint Lucia, Saint Vincent and the Grenadines

• Tropical Storm Watch: Grenada and its dependencies, the southern and western coasts of Haiti, from the border with the Dominican Republic to Le Mole le St. Nicholas, the southern coast of the Dominican Republic from the southern border of Haiti eastward to Punta Palenque, and Jamaica

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

Hazardous Conditions
Elsa will likely bring heavy rainfall, strong winds, and rough seas to coastal areas in the Windward and southern Leeward Islands through at least July 2. 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 7.5-15 cm (3-6 inches) of rainfall are likely over portions of the Windward and southern Leeward Islands, including Barbados. Models also indicate 1.5-8 cm (1-3 inches) of rainfall over Puerto Rico and 10-20 cm (4-8 inches) of rainfall over southern Hispaniola through at least July 3. Flooding could trigger flash floods and mudslides, isolating some communities for several days.

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, Elsa 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 July 2 in coastal areas of the Windward and southern Leeward Islands, including Barbados, as well as through at least July 3 in Puerto Rico and southern Hispaniola. 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
Barbados Meteorological Services
Cuba Instituto de Meteorologia (Spanish)
Dominican Republic Oficina Nacional de Meteorologia (Spanish)
Dominica Meteorological Service
Grenada Meteorological Office
Haiti Centre national de meteorologie (French)
Jamaica Meteorological Service
Meteo-France (French)
Saint Lucia Meteorological Services
Saint Vincent and the Grenadines