Philippine Sea: Tropical Storm Choi-Wan tracking northwestward in the Philippine Sea early June 1 /update 2

Event

Tropical Storm Choi-Wan (known in the Philippines as Dante) is continuing to track northwestwards in the Philippine Sea early June 1. As of 02:00 PHT, the storm's center of circulation was approximately 403 km (250 miles) southeast of Tacloban City, Philippines. Choi-Wan is forecast to strengthen further as it tracks along the eastern Philippines through June 4. The system is projected to shift to a northward, then northeastward direction starting June 3. Meteorologists expect the storm to make at least three landfalls: one near Dolores in northern Samar Island late June 1; a second near Legazpi City around midday June 2; and a third on far northeastern Luzon late June 3. Some uncertainty remains in the track and intensity forecast, and changes could occur over the coming hours and days.

Government Advisories
As of early June 1, Philippine authorities have forecast heavy rain and potentially damaging winds in Sorsogon, the eastern portion of Albay, Samar Island, Biliran, eastern portions of Leyte and Southern Leyte, the Dinagat Islands, Siargao, and the Bucas Grande Islands. Flash floods and landslides are possible. Authorities have also issued an orange severe general flood advisory (third-highest level on a five-tier scale) for watercourses in multiple areas of Mindanao.

Authorities may issue warnings for severe weather in parts of Taiwan and the far southern islands of Japan in the coming days, depending on the system's forecasted track.

Hazardous Conditions
Choi-Wan is forecast to bring heavy rainfall, strong winds, and rough seas to coastal areas of the eastern Philippines over the coming days. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Flooding could isolate some communities for several days. Prolonged swells and storm surge generated by the system will likely result in coastal flooding as the system tracks close to land. 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, damaging wind gusts will persist. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are possible. Electricity supply disruptions have occurred in some areas, including parts of Surigao del Sur Province, due to the flooding. Lingering outages may still occur in the coming days after the storm dissipates.

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 June 5. 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 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 storm 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 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.

Resources

Joint Typhoon Warning Center
Philippine Atmospheric Geophysical and Astronomical Services Administration