Philippine Sea: Tropical Storm Yun-yeung tracking northward south of Japan as of late Sept. 7 /update 3

Event

Tropical Storm Yun-yeung is tracking north-northeastward in the Philippine Sea late Sept. 7. As of 21:00 JST, the system's center of circulation was approximately 439 km (273 miles) southwest of Yokosuka, Kanagawa Prefecture, Japan.

Forecast models indicate that the storm will maintain tropical storm strength as it tracks north-northeastward over the Philippine Sea toward Japan through early Sept. 8. The system will likely make landfall over western Aichi Prefecture during the afternoon of Sept. 8 and weaken into a tropical depression as it passes over central Honshu Island through early Sept. 9. Yun-yeung will continue to weaken as it enters the Sea of Japan and turns to track northeastward off the coast of northwestern Honshu Island Sept. 9, dissipating over open waters. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of late Sept. 7, the Japan Meteorological Agency (JMA) has issued a bulletin regarding the storm system, warning of heavy rainfall, strong winds, and possible thunderstorms across eastern Japan and Tohoku Region in the coming days, as well as rough seas off the coasts of the Izu Islands and Kanto Koshin and Tokai regions. Rainfall totals of around 30 cm (12 inches) in Tokai Region and 25 cm in Kanto-Koshin Region and the Izu Islands are forecast late Sept. 7-8. Further amounts of 10-15 cm (4-6 inches) in Tohoku Region and 5-10 cm (2-4 inches) in Kanto-Koshin Region are expected late Sept. 8-9. Winds gusting up to 108 kph (67 mph) are possible in the Izu Islands and Tokai Region Sept. 7-8, as well as waves up to 5 meters (16 feet) in coastal waters. The JMA has also issued numerous yellow weather advisories (the lowest level on a four-tier scale) across central and southern regions. Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

All Nippon Airways (ANA) have canceled flights to and from Hachijojima Airport (HAC) in southern Izu Islands and Shizuoka Airport (FSZ) Sept. 8. The airline also warned of flight disruptions at Tokyo's Haneda (HND) and Narita (NRT) international airports Sept. 8-9. Japan Airlines (JAL) stated that its domestic flights to and from HND may experience irregular operations Sept. 8 due to the passage of the storm. JR Tokai has announced that there is a chance of suspensions on the Tokaido Shinkansen railway line from early Sept. 8.

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. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. 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

Joint Typhoon Warning Center (JTWC)
Japan Meteorological Agency (JMA)