Rain will fall across the country on Tuesday the 21st, while a heat wave continues, the weather agency said.
Central regions including the Seoul metropolitan area, Gangwon Province and the Chungcheong region are forecast to see heavy rain of 20 to 80 millimeters per hour from dawn through the morning. Some areas are expected to receive more than 150 millimeters.
Over the two days from the 20th to the 21st, expected rainfall totals are 30 to 100 millimeters in Seoul, Incheon and Gyeonggi Province and the five northwestern islands (more than 150 millimeters in northern Incheon and Gyeonggi), 30 to 100 millimeters in Gangwon's inland and mountainous areas (more than 150 millimeters in northern inland Gangwon), and 10 to 60 millimeters along Gangwon's east coast. Daejeon, Sejong and South and North Chungcheong provinces will see 30 to 80 millimeters (more than 100 millimeters along the northern west coast of South Chungcheong), Gwangju and South Jeolla 5 to 40 millimeters, North Jeolla 10 to 60 millimeters, Daegu and North Gyeongsang 10 to 60 millimeters, western inland South Gyeongsang 5 to 40 millimeters, and Jeju 5 millimeters. In the central regions where rain will concentrate, heavy rain accompanied by gusts, thunder and lightning may prompt a heavy rain advisory.
With heavy rain having fallen recently, the renewed heavy downpours in central regions could increase the risk of flooding in low-lying areas and underpasses, river overflows, landslides and soil runoff. Heavy rain is also expected in North Korea, raising the possibility of rapidly rising water levels in rivers in northern Gyeonggi and Gangwon, including the Imjin, Hantan and Bukhan rivers.
The heat wave will also continue. With heat wave advisories in effect for parts of the Chungcheong region, southern regions and Jeju Island, the highest perceived temperature in most parts of the country is expected to exceed 31 degrees Celsius. In particular, areas under heat wave advisories are expected to record perceived highs of around 33 degrees, and the South Jeolla region, the Gyeongsang region and Jeju Island around 35 degrees, requiring caution against heat-related illnesses.
Morning lows are forecast at 22 to 26 degrees, with daytime highs of 26 to 37 degrees. Waves in coastal waters will reach 0.5 to 1.5 meters in the East Sea and South Sea, and 0.5 to 1.0 meters in the West Sea. Wave heights in inner offshore waters (within about 200 kilometers of the coastline) are expected at 0.5 to 1.5 meters in the East, West and South seas.
