Japan: Tropical Depression Yun-yeung tracking north-northeastward toward Shizukoka Prefecture as of late Sept. 8 /update 5

Event

Tropical Storm Yun-yeung is tracking north-northeastward in the Philippine Sea and is approaching Shizuoka Prefecture late Sept. 8. As of 21:00 JST, the system's center of circulation was approximately 244 km (152 miles) southwest of Yokosuka, Kanagawa Prefecture.

Forecast models indicate that the weather system will continue to weaken as it continues to track north-northeastward and moves over Shizuoka Prefecture early Sept. 9. Yun-yueng is expected to continue to track north-northeastward as a tropical depression over Yamanashi, western Saitama, and Gunma prefectures Sept. 9, before dissipating as it approaches Fukushima Prefecture late Sept. 9. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of late Sept 8, the Japan Meteorological Agency (JMA) has issued a bulletin regarding the storm system, warning that linear rain belts ahead of the storm system are already causing heavy downpours across parts of Kanto-Koshin and Tohuku regions. Rainfall totals of around 15 cm (6 inches) are expected in these regions late Sept. 8-9. The JMA has also issued numerous weather warnings across the affected areas, including purple heavy rain and landslide warnings (the second highest level on a four-tier scale) and red heavy rain, inundation, and flood warnings for Chiba, Ibaraki, and parts of Fukushima prefectures. Red heavy rain and landslide warnings are also in place for the Izu Islands, the rest of Fukushima Prefecture, and parts of Kanagawa Prefecture. Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

Authorities have issued black emergency safety assurance evacuation warnings (the highest level on a three-tier scale) for more than 400,000 people in Kitaibaraki and Takahagi cities in Ibaraki Prefecture and Iwaki City in Fukushima Prefecture. Lower-level purple and red evacuation orders have been ordered for tens of thousands of other people across parts of Chiba, Fukushima, Ibaraki, and Miyagi prefectures. Further evacuation orders may be issued by authorities in the coming hours.

All Nippon Airways (ANA) canceled flights to and from Hachijojima Airport (HAC) in southern Izu Islands and Shizuoka Airport (FSZ) Sept. 8. The airline also warned of likely flight disruptions at Fukushima Airport (FKS) in Fukushima Prefecture and Tokyo's Haneda Airport (HND) Japan Airlines (JAL) stated domestic flights to and from HND and Narita International Airport (NRT) were experiencing irregular operations Sept. 8 due to the passage of the storm. JR East has suspended rail services on all of the Kururi and Togane lines and parts of the Sobu, Sotobo, and Uchibo lines Sept. 9. Several roads across the affected regions have been closed due to flooding and landslides, including sections of the Higashi-Kanto Expressway, the Ken-O Expressway, and the Tokyo Bay Aqua-Line. Authorities have warned of further possible closures along the East Japan, Metropolitan, and Shin-Tomei expressways.

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)