On Friday, the 20th, heavy monsoon rain will begin in the central region and Jeolla and Jeju provinces and will spread to most areas of the country. The capital region and Gangwon, where heavy rain warnings are already in effect, are expected to experience very heavy rainfall. The city of Seoul has implemented control measures for rivers such as Cheonggyecheon.
According to the Korea Meteorological Administration on the 20th, as of 8 a.m. that day, heavy rain warnings were issued for Gimpo, Dongducheon, Pocheon, Goyang, Yangju, and Paju in Gyeonggi Province, Hwacheon in Gangwon Province, and Incheon, while heavy rain advisories were in effect for Seoul and Gyeonggi's Gwangmyeong, Gwacheon, Ansan, Siheung, Bucheon, Yeoncheon, Gapyeong, Uijeongbu, Anyang, Guri, Namyangju, Gunpo, Uiwang, Hanam, Hwaseong, the five islands of the West Sea, Yanggu Flat in Gangwon, and Ganghwa and Ongjin in Incheon.
The rain that began in the central region, Jeolla, and Jeju will expand to the North Gyeongsang and South Gyeongsang regions from morning to noon. Starting in the afternoon, very heavy rain of 30 to 50 mm per hour will fall in the capital region and inland northern Gangwon, and from night in inland central and southern Gangwon, Sejong, and northern Chungcheong.
The rain will stop first in the capital region and central region during the day on Saturday, the 21st, and many other areas will show signs of improvement. However, the southern region and Jeju will continue to experience rain until the night of the 21st.
The expected rainfall from the 20th to the 21st is ▲ more than 150 mm in Seoul, Incheon, northern Gyeonggi, inland central and northern Gangwon, and southern Daejeon and Chungnam ▲ more than 120 mm in southern Gyeonggi, inland southern Gangwon, northern Sejong, Chungbuk, Gwangju, and northern Jeonnam ▲ 50 to 100 mm in Chungcheong and Jeonbuk ▲ 30 to 80 mm in Gwangju Metropolitan City, Jeonnam, Daegu, Gyeongbuk, and western Gyeongnam ▲ 20 to 80 mm in Jeju ▲ 20 to 60 mm in Busan, Ulsan, Gyeongnam, Ulleungdo, and Dokdo ▲ 10 to 50 mm on the eastern coast of Gangwon.
With a lot of rain expected, the city of Seoul decided to control 29 rivers, including Cheonggyecheon, Dorimcheon, Anyangcheon, Seongbukcheon, and Jeongneungcheon.
Strong winds are also expected. In the western part of the capital region, the South Chungcheong west coast, the Jeolla west coast, the mountainous areas of Gangwon, and Jeju, winds are expected to gradually blow very strongly above 20 m/s (over 25 m/s in mountainous areas) starting in the afternoon, with the possibility of strong wind advisories being issued.
The daytime high temperature will be between 23 and 31 degrees, about 2 to 5 degrees lower than the previous day. With heavy rain, most areas across the country will see daytime temperatures around 25 degrees, which is slightly lower than usual.