13 Dec 2020 | 05:39 PM UTC
South Pacific: Tropical Cyclone Six to bring severe weather to the South Pacific through at least Dec. 17
Tropical Cyclone Six to bring severe weather to the South Pacific through at least Dec. 17. Expect some utility and transport disruptions.
Event
Tropical Cyclone Six is gradually strengthening as it continues to track west-southwestward in the South Pacific on Dec. 13. As of 1315 Dec. 13, the storm’s center of circulation was approximately 417 km (259 miles) southwest of Pago Pago, American Samoa. Forecast models indicate the system will continue to move southwestward in the South Pacific Ocean through Dec. 17. As the current environment is favorable for intensification, the system will gradually weaken and transition into a post-tropical system. While the system will track to the east of Alofi, it will bring adverse conditions to islands in the area through Dec. 17. Some uncertainty remains in the track and intensity forecast, and some changes could occur in the coming days.
Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, and rivers, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Rain-induced landslides are possible in steeply sloped terrains. Flooding could isolate some communities for several days. Prolonged swells and storm surge generated by Tropical Storm Six will likely result in coastal flooding. Abnormally high tides are possible. In addition to the heavy rain, flooding, and storm surge, the storm will produce damaging wind gusts. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are likely.
Transport and Infrastructure
In addition to the immediate threat to personal safety, inclement weather associated with the storm is likely to trigger localized business, transport, and utility disruptions. Floodwaters and debris flows may render some bridges or roadways impassable, further 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, including Hanan Niue International Airport (IUE) and Eua Airport (EUA). Power outages are likely in areas that experience severe weather. 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
Heed the instructions of authorities as the storm approaches. 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 weeks. 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.
