The Korea Meteorological Administration forecast extreme heavy rain reaching 300 mm in total for the Seoul metropolitan area and Gangwon Province [1].
These forecasts indicate a high risk of landslides and urban flooding, threatening infrastructure and public safety in some of the country's most densely populated regions.
Officials said the precipitation is expected to begin around midnight tonight and continue through Sunday [2]. The weather system is being driven by a stationary front meeting a low-pressure system, which is expected to generate the extreme precipitation [2].
In some areas, rainfall rates could reach 80 mm per hour [1]. This exceeds the standard threshold for extreme rain, which is defined as 70 mm per hour [1]. The affected regions include the Seoul metropolitan area, Gangwon Province, and northern Chungcheong [1].
While some sporadic rain has been reported in the Daegu area of North Gyeongsang Province, the most intense portions of the monsoon rains have not yet arrived, a reporter for YTN News said [3].
A spokesperson for the Korea Meteorological Administration said the agency held an additional briefing to warn that the intersection of the stationary front and low-pressure system would result in very heavy rainfall [3]. Local authorities are urging residents to prepare for potential flooding and landslides as the weekend approaches.
An anchor for YTN News said that while the monsoon rains had paused briefly, tomorrow will be the critical point for the region [3].
“Rainfall rates could reach 80 mm per hour”
The convergence of a stationary front and a low-pressure system often creates a 'stalled' weather pattern, leading to concentrated, high-volume rainfall over a short period. When hourly rates exceed 70 mm, urban drainage systems in cities like Seoul can be quickly overwhelmed, increasing the likelihood of flash floods and soil saturation that triggers landslides in mountainous provinces like Gangwon.
