Heavy Rainfall Returns After Heatwave... 150mm Water Bomb Expected

The nationwide heatwave that had been raging has subsided, and the monsoon rains have returned. The Korea Meteorological Administration (KMA) forecasted that the Seoul metropolitan area could receive a 'water bomb' of over 150mm of rain.

On the 4th, the KMA reported that as of the morning, rain was falling in the Honam and Chungnam regions in the western part of the Korean Peninsula. The rain is expected to spread to Incheon, the western coast of Gyeonggi, and Jeju in the morning; to Seoul, inland Gyeonggi, inland Gangwon, Gangwon mountain areas, Chungbuk, and Yeongnam in the afternoon; and by night, to the eastern coast of Gangwon.

This rain is expected to continue until the morning of the 5th. Total precipitation is forecasted to be 50-100mm in the Seoul metropolitan area, inland Gangwon, Gangwon mountain areas, Chungcheong, northern inland Gyeongbuk, Honam, southern coastal Gyeongnam, Jeju, the five western islands, Ulleungdo, and Dokdo (with some areas in the Seoul metropolitan area, Chungnam, Honam, Jeju, and the five western islands receiving over 150mm, and inland Gangwon and Chungbuk receiving up to 120mm). The eastern coast of Gangwon, northern eastern coast of Gyeongbuk, southern Gyeongbuk, and Gyeongnam (excluding the southern coast) are expected to receive 20-60mm.

As the monsoon front moves northward, heavy rain began to fall in Seoul and the metropolitan area on the 26th. Citizens passing through Gwanghwamun Square in Seoul are hurrying along with umbrellas. Photo by Dongju Yoon doso7@

In particular, some areas may experience rainfall exceeding 70mm per hour in the early morning of the 5th, with hourly precipitation reaching 30-60mm at times. The expected peak rainfall times by region are: Honam on the morning of the 4th and early morning of the 5th; central regions (excluding the eastern coast of Gangwon) and northern inland Gyeongbuk from the night of the 4th to early morning of the 5th; and southern coastal Gyeongnam and Jeju from early morning to morning on the 5th.

The KMA issued preliminary heavy rain warnings for some areas including the five western islands, Gyeonggi Province, Gangwon Province, and Chungcheongnam-do starting from the afternoon of the 4th. These preliminary warnings may be upgraded to full heavy rain warnings.

The alternating issuance of heavy rain and heatwave warnings this summer, resulting in unpredictable weather, is largely due to the influence of a developing low-pressure system. The low-pressure system over the West Sea is pulling the monsoon clouds located south of the Korean Peninsula inland all at once, causing a very wide movement of rain clouds. The stationary front is moving rapidly up and down, and the low-pressure system overlapping with the monsoon front is occurring more frequently than before, resulting in what is called the 'Hong Gil-dong monsoon' repeating.

After this rain ends, the heatwave will return for a few days. From the daytime of the 5th, the perceived temperature is forecasted to exceed 33 degrees Celsius mainly in the inland Gyeongsang region, and from the daytime of the 6th, mainly in the southern inland areas. After the 6th, heatwaves and frequent showers are expected to continue mainly in the central regions. From Friday the 7th onward, the stationary front bringing rain is expected to move north again, possibly bringing rain to Jeju and the southern regions.

The KMA stated, "The expected precipitation areas and amounts may change depending on the speed and path of the low-pressure system and the stationary front."

This content was produced with the assistance of AI translation services.