South Korea: Tropical Depression Pulasan tracking east-northeastward towards South Joella Province as of Sept. 21 /update 8

Tropical Depression Pulasan is tracking east-northeastward across the Yellow Sea and is approaching southwestern South Korea Sept. 21. As of 15:00 KST, the system's center of circulation was approximately 209 km (130 miles) south-southwest of Kunsan Airbase, North Joella Province, South Korea.

Forecast models indicate that the weather system will make landfall over southwestern South Joella Province in South Korea in the coming hours before skirting along the southern coasts of South Joella Province, South Gyeongsan Province, and Busan late Sept. 21. The system will likely strengthen into a tropical storm as it tracks east-northeastward over the Sea of Japan before making landfall over the Oki Islands, Shimane Prefecture, Japan, early Sept. 22. Pulasan is forecast to make further landfalls in Ishikawa then Niigata prefectures, Japan, Sept. 22. The system will track east-northeastward across Tohoku Region and into the Pacific Ocean late Sept. 22, before transitioning into a post-tropical cyclone as it moves away from Japan early Sept. 23. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

The Korea Meteorological Administration has warned of further strong winds and heavy rainfall in southern regions, including Jeju Island, over the coming hours. As of early Sept. 21, authorities have issued rainfall warnings for parts of South Gyeongsang and South Joella provinces, as well as Busan and Ulsan metropolitan cities. Rainfall advisories are in place across other southern areas of South Korea. Strong wind warnings and advisories are in place across southern regions and strong wave warnings have been issued in southern coastal areas, as well as storm surge advisories for coastal areas of South Joella Province.

Flooding and landslides triggered by heavy rainfall since late Sept. 20 have led to around 500 people being evacuated across southern parts of Soth Korea as of early Sept. 21, with parts of North Gyeongsang Province the worst affected. Dozens of roads have been flooded in affected areas and some homes and other buildings have been inundated. The heavy rainfall also caused a sinkhole to open up in Busan's Sasang District.

Heavy rainfall is already affecting areas of Japan mainly along the Sea of Japan coast due to a linear rain belt and the arrival of the storm system will likely exacerbate the situation. As of Sept. 21, a black special heavy rain warning (the highest level on a four-tier scale) has been issued for parts of Ishikawa Prefecture and purple, red, and yellow heavy rainfall, landslides, flood, strong winds, rough seas, storm surge, and thunderstorm warnings are in place across parts of Hokuriku, Tohoku, and Northern Kyushu regions. Purple-level evacuation orders (the second highest level on a five-tier scale) have been issued across parts of Akita, Yamagata, Niigata, and Ishikawa prefectures as of Sept. 21.

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.

Inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures 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.