North Atlantic Ocean: Tropical Storm Gaston tracking northeastward Sept. 21

Event

Tropical Storm Gaston is tracking northeastward in the central North Atlantic Ocean Sept. 21. As of 14:00 AZOT, the storm's center of circulation was approximately 1,250 km (775 miles) west of the Azores.

Forecast models indicate the system will strengthen slightly as it tracks northeastward and then east-northeastward Sept. 21-22. The storm is then expected to weaken slightly as it largely stalls north of the western Azores Sept 23-24 and makes turns to the east, southeast, south, and then west-northwest and moves away from the Azores. During this stalling the storm is expected to transition into a post-tropical cyclone. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of 14:00 AZOT Sept. 15, authorities have not issued any tropical storm watches or tropical storm warnings associated with the storm. The Portuguese Institute for Sea and Atmosphere (IPMA) has issued yellow heavy rainfall warnings Sept. 22 and yellow strong wind warnings Sept. 23 for the western Azores. Officials could issue new warnings and/or watches in response to the developing system in the coming hours.

Forecast models indicate the storm will bring gale-force winds to western parts of the Azores and swells across the seas surrounding the islands Sept. 22-24.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible if weather conditions prove hazardous.

The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.

Advice

Activate contingency plans in areas where officials forecast typhoon or 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
Portuguese Institute for Sea and Atmosphere (IPMA)