Philippine Sea: Tropical Storm Yun-yeung tracking north-northeastward as of late Sept. 6 /update 1

Event

Tropical Storm Yun-yeung is tracking northeastward in the central Philippine Sea late Sept. 6. As of 21:00 JST, the system's center of circulation was approximately 954 km (593 miles) south-southwest of Yokosuka, Kanagawa Prefecture, Japan.

Forecast models indicate that the storm will strengthen slightly as it tracks generally northeastward over the Philippine Sea Sept. 6-7. The system is expected to weaken slightly and pass through the southern Izu Islands, Tokyo Prefecture, Japan, early Sept. 8. The storm is then forecast to continue to slowly weaken as it tracks northeastward and makes landfall over southeastern Chiba Prefecture late Sept. 8. The system is likely to weaken into a tropical depression as it skirts along the Chiba coastline and then tracks northeastward off the eastern coast of Honshu Island Sept. 9, before dissipating as it turns to track east-northeastward away from Honshu Sept. 10. Uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of late Sept. 6 the Japan Meteorological Agency (JMA) has issued numerous weather warnings across parts of the country, including red heavy rain/landslide warnings for parts of Ibaraki and Tochigi prefectures in Kanto Koshin Region; however, separate weather systems are currently impacting several areas of Japan and not all advisories are linked directly to the storm system. Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

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)