Philippine Sea: Typhoon Nanmadol tracking north-northwestward in the Philippine Sea early Sept. 18 /update 3

Event

Typhoon Nanmadol is tracking north-northwestward over the Philippine Sea early Sept. 18. As of 06:00 JST, the system's center of circulation was approximately 419 km (260 miles) east-northeast of Kadena Air Base, Okinawa Prefecture, Japan.

Forecast models indicate that Nanmadol will weaken slightly and make landfall over the Osumi Islands, Kagoshima Prefecture, Japan, the afternoon of Sept. 18. The storm is then forecast to continue northward, making another landfall as a typhoon over Kagoshima Prefecture, Japan, late Sept. 18 before continuing northwards across southwestern Kyushu. Nanmadol is forecast to make a subsequent landfall as a typhoon over Kumamoto Prefecture early Sept. 19 before weakening slightly while tracking northeastward across central Kyushu and exiting into the Seto Inland Sea. Subsequent landfalls as a typhoon are forecast over southeastern Yamaguchi and southern Hiroshima prefectures later the same day. Nanmadol is forecast to weaken into a tropical storm as it tracks east-northeastward across the southern Chugoku region before weakening further over the northern Kinki, northern Chubu, and southern Tohoku regions and exiting into the North Pacific Ocean from eastern Fukushima Prefecture early Sept. 21. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of early Sept. 18, the Japan Meteorological Agency (JMA) has issued purple (highest level on a three-tier scale) storm, storm surge, high wave, and landslide warnings across Kagoshima, Kochi, southern Miyazaki, most of Kumamoto, Saga, and Nagasaki prefectures. Orange warnings are in place across the rest of southwestern and western Japan. Officials will likely issue relevant weather alerts over the coming days as the system progresses.

The JMA has warned of storms, high waves, storm surges, landslides, and flooding in low-lying and riverine areas in Kyushu and Shikoku. Forecast models indicate heavy rainfall of 60 cm (24 inches) in southern Kyushu, 40 cm (16 inches) over northern Kyushu and Shikoku, 30 cm (12 inches) in the Tokai region, and 25 cm (10 inches) in the Kinki region. Lesser rainfall amounts are forecast over the rest of western and southern Japan.

As of early Sept. 18, one person remains missing after being washed away from Katsurahama Beach in Kochi City early Sept. 16. Search and rescue operations are being hampered by the large waves. Authorities have confirmed one death in Mikawa Port of Toyohashi City, Aichi Prefecture Sept. 17.

Authorities have issued evacuation orders for at least 80,000 people in Kumamoto Prefecture, 619,000 people in Miyazaki Prefecture, and 1,268,000 people in Kagoshima Prefecture. Around 7,960 households in Kagoshima Prefecture and 1,770 households in Miyazaki Prefecture are without power. Convenience stores across Fukuoka, Saga, Nagasaki, Oita, Kumamoto, Miyazaki, Kagoshima, Hiroshima, and Yamaguchi prefectures are closed.

Authorities have suspended operations on the Kyushu Shinkansen between Kumamoto and Kagoshima-Chuo stations and between Hakata and Kumamoto from Sept. 18. Some train services on the Sanyo Shinkansen are also suspended. Most train services across southern Kyushu are canceled Sept. 18. Officials at the Fukuoka City Subway have warned that above-ground services, especially on the Airport and Hakozaki lines, may be canceled Sept. 18-19.

Japan Airlines (JL) and All Nippon Airways (NH) have canceled most flights in Kyushu and Shikoku as well as the Chugoku region and the Ryukyu Islands Sept. 18-19. Amakusa Airlines (MZ) has canceled all flights from the afternoon of Sept. 17. Additional flight cancelations are likely as the storm approaches and conditions worsen.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible if weather conditions prove hazardous. The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.

Advice

Activate contingency plans in areas where officials forecast typhoon or 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
Korea Meteorological Administration