Rain is forecast nationwide throughout the upcoming three-day Liberation Day long weekend.

Affected by easterly winds left behind by the dissipated typhoon Chan-hom, 10 to 50 millimeters of rain is expected in the east coast and mountainous areas of Gangwon Province and the east coast of North Gyeongsang Province through tomorrow (August 14). Additionally, 10 to 40 millimeters of much-needed rain is forecast for the southern coast of South Gyeongsang Province, which has suffered from severe drought.

Starting Saturday, August 15, the Liberation Day long weekend, large amounts of water vapor left by typhoon Dolphin, which dissipated after passing through China, will flow into the Korean Peninsula.

Rain is expected to begin in Jeju on August 15 and expand to most regions across the country between the night of August 16 and Monday, August 17, which is a substitute public holiday.

The Korea Meteorological Administration urged thorough preparations, warning that depending on the inflow of water vapor and changes in pressure patterns, some regions could see heavy downpours rather than simple refreshing rain.

The rare forecast for rain appears to be driven by the residual pressure systems of large typhoons that bypassed the Korean Peninsula, disrupting atmospheric pressure flows around the region.

During the period of typhoon influence, a dual heat dome formed as the Tibetan High in the upper atmosphere and the North Pacific High below it simultaneously covered the Korean Peninsula strongly.

Consequently, the typhoons were forced to steer toward China or Japan along the edges of the high-pressure systems, but powerful rain clouds formed as the strong water vapor left behind by the typhoons flowed in.

Meanwhile, the newly generated 17th typhoon Nangka is also expected to move toward the waters east of Japan, making it unlikely to have a direct impact on South Korea for the time being.

Intense heat is projected to make a comeback after the rain and showers stop.

Daytime temperatures began rising again starting August 13, and heatwaves and tropical nights are expected to persist through next week, with maximum perceived temperatures soaring above 33°C (91°F) in most parts of the country.

(Reported by Kim Jiuk | Video by Lee Eui-sun | Graphics by Yook Do-hyun | Produced by SBS Digital News)