Philippine Sea: Typhoon Muifa tracking northward as of late Sept. 11; landfall forecast over Yaeyama Islands, Japan, Sept. 12 /update 3

Event

Typhoon Muifa is tracking northward over the Philippine Sea late Sept. 11. As of 21:00 JST, the system's center of circulation was approximately 500 km (311 miles) southwest of Kadena Airbase, Okinawa Prefecture, Japan.

Forecast models indicate that the storm will weaken slightly as it continues to track northward Sept. 12, making landfall over Ishigaki Island in the Yaeyama Islands, Okinawa Prefecture, early afternoon Sept. 12. The system is expected to continue to weaken slightly as it tracks northward aand enters the East China Sea Sept. 13. The storm is then forecast to turn to track north-northwestward Sept. 14 and will weaken to a tropical storm as it skirts over the coasts of northeastern Zhejiang and southeastern Jiangsu provinces, as well as Shanghai Municipality. in eastern China Sept. 15. The system is expected to weaken to a tropical depression as it tracks north-northwestward over the western Yellow Sea and approaches eastern Shandong Province late Sept. 16. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

The Japan Meteorological Agency (JMA) has warned of rough seas, storm surge, heavy rainfall, and strong winds over the Sakishima Islands in Okinawa Prefecture Sept. 11-13. Winds of around 162 kph (101 mph) are expected in the region Sept. 12 and 108-144 kph (67-89 mph) Sept. 13, with stronger gusts. Waves of around 10 meters (33 feet) are expected in coastal areas Sept. 12-13. Rainfall totals of around 20 cm (8 inches) are expected over affected areas of Okinawa Prefecture late Sept. 11-late Sept. 12 Heavy rainfall may be accompanied by thunderstorms and could trigger flooding and landslides over affected islands. Storm surge is possible around coasts and river mouths on the Sakishima Islands early Sept. 12. As of late Sept. 11, the JMA has issued purple storm surge warnings (the highest level on a three-tier scale), red flood, high waves, and storm gale warnings and yellow heavy rainfall, landslides. and thunderstorm warnings for Okinawa's Ishigakijima region. Red storm gale and high waves warnings and yellow thunderstorm warnings have been issued for Miyakojima and Yonagunijima regions of Okinawa. Yellow high wave warnings have been issued for Kumejima and central, northern, and southern mainland Okinawa and yellow storm surge warnings for central and southern mainland Okinawa.

The Taiwan Central Weather Bureau has issued a red torrential rain advisory (the second highest level on a four-tier scale) for mountainous areas of New Taipei City from late Sept. 11 through Sept. 13. An orange extremely heavy rainfall advisory has been issued for mountainous areas of Taoyuan City and yellow heavy rainfall advisories for Keelung North Coast, mountainous areas of Taipei City, the rest of New Taipei City, the rest of Taoyuan City, Hsinchu County, Miaoli County, mountainous areas of Taichung City, mountainous areas of Nantou County, and Yilan County.

The China Meteorological Administration had issued a blue typhoon warning (the lowest level on a four-tier scale) advising strong winds are expected over many eastern coastal waters and moderate to heavy rainfall in southeastern Jiangsu, northern Shanghai, and the eastern coast of Zhejiang provinces. Rainfall amounts of 10-15 cm (4-6 inches) are possible in affected areas late Sept. 11-late Sept. 12.

Officials will likely issue relevant weather alerts and warnings over the coming days as the system progresses.

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. 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
Japan Meteorological Agency
Taiwan Central Weather Bureau
China Meteorological Administration
Korea Meteorological Administration