Philippine Sea: Tropical Storm Mawar tracking north-northeastward east of Taiwan as of early May 31 /update 11

Event

Tropical Storm Mawar (named Betty in the Philippines) has weakened and is tracking north-northeastward across the Philippine Sea early May 31. As of 12:00 JST, the storm was approximately 615 km (382 miles) south-southwest of Kadena Air Base, Okinawa Prefecture, Japan.

Forecast models indicate that the system will weaken further as it turns slowly to track northeastward, passing far east of Taiwan through May 31. Mawar is then forecast to make a close approach to Okinawa Prefecture, Japan, June 1-2, passing southeast of Miyako Island early June 1 and south of Okinawa Island early June 2, before tracking northeastwards along mainland Japan's southern then eastern coast June 3-5. Some uncertainty remains in the track and intensity forecast; changes could occur in the coming days.

As of May 31, the Japan Meteorological Agency (JMA) has issued orange (middle level on a three-tier scale) high wave warnings across the Ishigaki and Yonaguni islands in Okinawa Prefecture, while yellow high wave advisories are in place across the rest of Okinawa Prefecture. Yellow thunderstorm and gale advisories are also in effect over the Ishigaki and Yonaguni islands.

The Taiwan Central Weather Bureau has issued orange (second-lowest level on a four-tier scale) extremely heavy rain advisories over southern Yilan County and yellow heavy rain advisories over Hsinchu and Hualien counties and Keelung, New Taipei, Taipei, Taichung, and Taoyuan cities. Strong wind advisories are in place for southeastern and western Taiwan.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Reports indicate that large waves on the eastern coast of Taiwan early May 28 resulted in one fatality in Hualien County, while one person is missing in Yilan County.

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 other regional airports and temporary closures of ports are also possible. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a severe health threat.

Advice

Activate contingency plans in areas where officials forecast tropical cyclone 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
Taiwan Central Meteorological Bureau
Japan Meteorological Agency (JMA)