North Atlantic: Potential TC Two tracking westward in the North Atlantic Ocean June 28 /update 1

Event

Potential Tropical Cyclone Two is tracking westward over the North Atlantic Ocean June 28. As of 11:00 AST, the system's center of circulation was approximately 420 km (260 miles) east of Trinidad, Trinidad and Tobago. The storm system has yet to be classified as a tropical storm due to a lack of a well-defined structure; however, it will likely form into a tropical storm over the next 24-48 hours, upon which it will be renamed Tropical Storm Bonnie.

Forecast models indicate that the storm will generally maintain its strength as it tracks west-northwestward across the North Atlantic Ocean June 28, making landfall over northeastern Trinidad late that day. The storm system is expected to continue to track generally west-northwestward close to the coast of Venezuela June 29-30, possibly making further landfalls over parts of Sucre State, Isla Margarita, and Falcon State in Venezuela and La Guajira Department in northeastern Colombia. The storm is then forecast to strengthen as it tracks westward across the southeastern Caribbean Sea June 30-July 1 and may reach hurricane strength by the time it makes landfall over Nicaragua's eastern coast early July 2. The storm is forecast to track generally west-northwestward across southern Nicaragua before exiting into the North Pacific Ocean late July 2.

Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days. This will be partially dependent on the interaction it has over landfall and a slight change in track could have a significant effect on the development of the storm. If the system stays largely over water in the coming days, it will likely strengthen significantly as it tracks generally westward over the Caribbean Sea towards Central America. Conversely, the storm could intensify to a much lesser extent if it tracks slightly further south and inland as it passes over the Venezuelan coast.

As of June 28, the following watches and warnings are in place:

• Tropical Storm Warning: Trinidad and Tobago; Grenada and its dependencies; the Venezuelan islands of Coche, Cubagua, and Islas de Margarita; Bonaire; Curacao; and Aruba.

• Tropical Storm Watch: The coast of Venezuela from Pedernales to Cumana.

Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

Heavy rainfall is forecast across the southern Windward Islands and the northeastern coast of Venezuela late June 28-29. Forecast models indicate rainfall of 2.5-7.5 cm (1-3 inches) from Guadeloupe to Saint Lucia; 7.5-12.5 cm (3-5 inches) over Saint Vincent, the Grenadines, Barbados, Aruba, Bonaire, and Curacao; and 10-15 cm (4-6 inches) over Grenada, Trinidad and Tobago, and northeastern Venezuela.

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. 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
Belize National Meteorological Service (NMS)
Colombia Institute of Hydrology, Meteorology and Environmental Studies (IDEAM)
Costa Rica National Institute of Meteorology
El Salvador National Service of Territorial Studies
Hidromet (Panama)
National Weather Service
Nicaragua Institute of Territorial Studies
Saint Lucia Meteorological Services
Saint Vincent and the Grenadines
Trinidad and Tobago Meteorological Service
Venezuela National Institute of Meteorology and Hydrology (INAMEH)