Fishing boats are docked at a port in Pohang, 374 kilometers southeast of Seoul, on Sept. 1, 2022, as Typhoon Hinnamnor approaches the Korean Peninsula. Yonhap

Typhoon Hinnamnor is forecast to reach waters off Jeju Island this week as a "super strong" typhoon, the strongest on a four-tier scale, the state weather agency said Sunday.

According to the Korea Meteorological Administration (KMA), the typhoon, the 11th this year, is expected to arrive 460 kilometers south-southwest of the southern island of Jeju around 9 a.m. Monday, with an atmospheric pressure of 920 hectopascals at its center and a maximum wind speed of 54 meters per second.

Typhoons are classified into four categories, from medium to strong, very strong and super strong.

Super strong refers to typhoons with a maximum wind speed of at least 54 meters per second.

By 9 p.m. Monday, Typhoon Hinnamnor is forecast to reach waters 180 km south-southwest of Jeju as a "very strong" typhoon before moving further north to 20 km north-northwest of the southeastern port city of Busan by 9 a.m. Tuesday, according to the KMA.

The typhoon's strength when it reaches Busan is forecast to weaken to "strong," with an atmospheric pressure of 950 hectopascals at its center and a maximum wind speed of 43 meters per second, making it the strongest typhoon ever to make landfall in South Korea.

According to the Central Disaster and Safety Countermeasures Headquarters, preliminary weather advisories were issued in the southern cities of Gwangju, Busan, Daegu and Ulsan and in the surrounding provinces of South and North Jeolla and South Gyeongsang at 5 a.m. Sunday.