Philippine Sea: Tropical Storm Choi-Wan tracking northwestward in the Philippine Sea along the eastern coast of the Philippines, June 1. /update 3

Event

Tropical Storm Choi-Wan (known in the Philippines as Dante) continues to track northwestwards in the Philippine Sea off the coast of the eastern Visayas region of the Philippines, June 1. As of 14:00 PHST, the storm's center of circulation was approximately 730 km (453 miles) east-southeast of Manila. Choi-Wan is forecast to maintain its strength as a tropical storm it makes a close approach near northern Samar Island early June 2. Following landfall, the system will continue tracking along the eastern Philippines with subsequent landfalls in the eastern Bicol region, June 2, and the eastern Central Luzon region June 3. The system is projected to shift to a northward, then northeastward direction starting June 3 as it weakens slightly into a Tropical Depression. Choi-Wan is forecast to track in a northeasterly direction as a tropical depression through at least June 6 bringing impacts to far southern Taiwan and far southern Japan, eventually dissipating east of the Okinawa islands of Japan. Some uncertainty remains in the track and intensity forecast, and changes could occur over the coming hours and days. At least three people have died in the Philippines as a result of the flooding associated with Choi-Wan.

Government Advisories
As of June 1, Philippine authorities have issued the following warnings:

• Tropical Cyclone Wind Signal Number 2: Catanduanes, the southern portions of Camarines Sur, Masbate including Ticao and Burias Islands, Albay, Sorsogon, Eastern Samar, Samar, Northern Samar, Biliran, Leyte, Southern Leyte, Dinagat Islands, Siargao Island, and Bucas Grande Island provinces

• Tropical Cyclone Wind Signal Number 1: Quezon including Polillo Islands, Camarines Norte, the remaining portions of Camarines Sur, Marinduque, Romblon, Aklan, Capiz, northern and central portions of Iloilo, northern portions of Negros Occidental, Bohol, northern and central portions of Cebu including the Bantayan and Camotes Islands, remaining portions of Surigao del Norte, Surigao del Sur, Agusan del Norte, Agusan del Sur, and the northeastern portions of Misamis Oriental provinces

• General Flood Advisory: Portions of Surigao del Norte, Agusan Del Sur, Dinagat Islands, Surigao Del Sur, Agusan Del Norte, Lanao Del Norte, Misamis Occidental, Camiguin, Misamis Oriental, Bukidnon, Negros Oriental, Cebu, Siquijor, Bohol, Capiz, Antique, Guimaras, Negros Occidental, Iloilo, Aklan, Camarines Sur, Catanduanes, Camarines Norte, Masbate, Albay, and Sorsogon provinces

Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days. Weather warnings could remain active even after the system’s immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards. The possibility of localized evacuations cannot be discounted if weather conditions prove particularly hazardous.

Hazardous Conditions
Tropical Storm 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. inundation where hard, dry soil cannot absorb rainfall. Rain-induced landslides are possible in steeply sloped terrains, 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 6. 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
Japan Meteorological Agency
Central Weather Bureau (Taiwan)