Heavy Rain Advisories Issued for Chungcheong and Southern Regions... 'Secondary Monsoon' Expected Nationwide This Weekend

[Anchor]

Heavy rain advisories were issued in various parts of the Chungcheong and southern regions today (the 28th), bringing heavy and disruptive downpours. A significant amount of rain is forecasted nationwide for this weekend, with experts analyzing that a so-called "secondary monsoon" has begun.

Reporter Jeong Gu-hui has the details.

[Reporter]

This is the radar imagery from today.

Heavy rain fell across various parts of the country. In particular, Sejong was hit by torrential downpours exceeding 80 mm per hour, surpassing the threshold for extreme rainfall set at 72 mm per hour.

Busan received over 100 mm of rain today alone. As you can see, the walking trails along Oncheoncheon Stream that were visible this morning are now completely submerged underwater.

The rain is forecasted to continue nationwide through this weekend and into Monday.

With the rain continuing for several days, it can be seen as the beginning of a so-called "secondary monsoon," although it is not an official terminology used by the Korea Meteorological Administration.

The rain falling today and tomorrow is due to a large amount of water vapor flowing in along the edge of the North Pacific high-pressure system positioned to the southeast of the Korean Peninsula.

Rain is also falling as a stationary front, often called a monsoon front, forms—and the rain starting from Sunday falls under this category.

The monsoon begins in early summer as the North Pacific high-pressure system expands from Japan toward the Korean Peninsula, and it ends when the high-pressure system expands all the way up to North Korea and covers the country.

However, rain falls for similar reasons during the latter part of summer like now, when the North Pacific high-pressure system loses strength and contracts.

This is called a secondary monsoon, or an autumn monsoon if it arrives in the autumn.

During the contraction period of the North Pacific high-pressure system, the high-pressure system is not very strong, so its position easily shifts, causing rain to sometimes end in a single day or continue for several days.

Tomorrow, 20 to 60 mm of rain is expected nationwide, with up to around 80 mm in the Chungcheong and Jeonbuk regions.

The amount of rain for the Seoul metropolitan area on Sunday is 5 to 30 mm, but as the monsoon front develops, up to 80 mm of rain is expected in Chungcheong and Honam, and up to 60 mm in Gyeongsang.

Some areas will see cumulative precipitation exceeding 100 mm over the weekend alone, and special caution is required in the southern coast of Gyeongsang, including Geoje and Tongyeong, as the ground has been weakened.

(Video Editing: Kim Yun-sung, Design: Seo Seung-hyun)
※ Please note: This article was translated by AI and may contain errors.