The government has ordered the nation's disaster control tower to launch Level One emergency operation as Typhoon Chanthu was forecast to pour up to 80 millimeters of rain per hour along the southern coast and Jeju Island.
The Interior Ministry on Wednesday also raised the crisis alert level from the lowest "attention" to "caution."
During a meeting among relevant agencies on Wednesday, Interior Minister Jeon Hae-cheol ordered inspections in areas expected to be affected by the deluge and for coastal area residents to be evacuated upon signs of danger.
Ahead of next week's Chuseok holiday, the minister called for thorough steps to be made to prevent floods in traditional markets nationwide. Traffic safety measures are also to be reexamined as people visit their hometowns or travel elsewhere.
Typhoon Chanthu is forecast to travel slowly northward at up to nine kilometers per hour towards southwest of Jeju Island's Seogwipo until Thursday. It is then expected to shift northeast to inch closer just south of Jeju on Friday.