Rain is forecast nationwide from Thursday evening and throughout Children's Day on Friday. 

According to the Korea Meteorological Administration(KMA), rainfall on the southernmost island of Jeju and South Jeolla Province, which began on Wednesday, is forecast to spread across North Jeolla, Chungcheong and North Gyeongsang provinces on Thursday afternoon. 

Other parts of the country, including the Seoul metropolitan area, will also likely see rain later in the day. 

Torrential rain of more than 30 millimeters per hour may hit some areas in Jeju, southern coastal areas, central regions and Jeolla provinces on Thursday. 

Up to 200 millimeters are in the forecast for Jeju Island and regions along the southern coast by Saturday. The capital area may see downpours of up to 120 millimeters during that period, with 30 to 100 millimeters for other parts of the nation. 

A heavy wind advisory has been issued for mountainous areas on Jeju, with a maximum expected wind velocity of over 90 kilometers on the island and the coastal regions.