Japan: Tropical Storm Mawar tracking east-northeastward south of Shikoku early June 3 /update 15

Event

Tropical Storm Mawar is tracking east-northeastward across the North Pacific Ocean, south of Shikoku, early June 3, following landfall over Okinawa Island late June 1. As of 06:00 JST, the storm was approximately 735 km (457 miles) southwest of Yokosuka City, Kanagawa Prefecture.

Forecast models indicate that the system will weaken slightly as it tracks far south of mainland Japan's southern coast and makes a close approach to the Izu Islands, Tokyo Prefecture the afternoon of June 3 before continuing northeastward away from Japan through the afternoon of June 4. Some uncertainty remains in the track and intensity forecast; changes could occur in the coming days.

As of early June 3, the Japan Meteorological Agency (JMA) has warned of flooding, landslides, thunderstorms, and tornadoes across eastern Japan and of landslides across western Japan through June 3. Additional rainfall of 12 cm (5 inches) is forecast over the Izu Islands and an additional 10 cm (4 inches) is likely over the Kanto and Koshin regions through early June 4.

Authorities have issued purple (highest level on a three-tier scale) landslide warnings across Chiba, Ibaraki, Kanagawa, Shizuoka, northern Wakayama, and western Yamanashi prefectures and orange landslide and flood warnings across Tokyo, southern Saitama, the rest of Wakayama, and the rest of Yamanashi. Yellow advisories are also in effect over most of the rest of southern and eastern Japan. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Authorities in Okinawa Prefecture have rescinded all evacuation orders. Evacuation orders are in place for more than 1,275,000 people across central and eastern Japan, with the worst affected Gifu, Nara, Osaka, Tokushima, and Wakayama prefectures. Additional evacuation orders are likely as the storm approaches and weather conditions deteriorate. Reports indicate that the river through Wakayama City has flooded downstream of Hatori Bridge, and the Toki River is flooded near Kamado District in Mizunami City. Due to floodwaters, one person in Aichi Prefecture died June 2, and at least two people remain missing in Wakayama Prefecture.

All Nippon Airways (NH) has canceled all flights at Hachijojima Airport (HAC) June 3 and have warned that some flights at Nemuro Nakashibetsu Airport (SHB) may be canceled or delayed due to strong winds. Japan Airlines (JL) has warned that flights across Honshu may be delayed or canceled June 3 due to heavy rainfall and strong winds. Train services to Kansai International Airport (KIX) were suspended June 2.

Authorities suspended all services on the Tokaido Shinkansen June 2 due to heavy rain; services from Hakata to Nagoya resumed, but services from Tokyo to Nagoya remain suspended as of early June 3. Authorities temporarily suspended the Sanyo Shinkansen on the inbound line between Shin-Osaka and Hiroshima; services have since resumed. Numerous other local trains are remain suspended. Train services are likely to resume once it is safe to do so. The Tokyo Bay Ferry was suspended June 2 due to strong winds and high waves, but services have since resumed. The Hachioji Bypass is closed between the intersection of Motohashimoto in Midori Ward, Sagamihara City, and the intersection of Yarimizu Kita in Hachioji City due to landslides and damage. The Tomei Expressway is closed between the Oi Matsuda Interchange in Oimachi, Kanagawa Prefecture, and the Yaizu Interchange in Yaizu City, Shizuoka Prefecture, due to heavy rain. Reports indicate that more than 17,500 homes in the Kanto Region were without power; most power has been restored.

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
Japan Meteorological Agency (JMA)