A citizen is seen huddling from the cold at Gwanghwamun Intersection in Jongno-gu, Seoul, on the chilly morning of the 2nd. (Yonhap News)
Starting from the 18th, after heavy autumn rain falls nationwide, a ‘roller coaster’ of weather is expected with temperatures dropping rapidly.
On the 17th, the Korea Meteorological Administration announced, “After this weekend’s heavy rain across the country, temperatures will drop sharply, falling below seasonal averages.” Some areas may experience thunderstorms, lightning, and gusty winds, prompting heavy rain warnings, while strong winds could lead to marine wind warnings, indicating expected hazardous weather.
The rain will begin on the night of the 17th in Jeju and spread across the country by the 18th, continuing until the 19th. Expected precipitation is 20-60mm (over 80mm in some places) in the Seoul metropolitan area, inland Gangwon, and Chungcheong, and 50-100mm (over 120mm in some places) in the eastern coast and mountains of Gangwon.
In Jeolla, 10-60mm (over 80mm in some places) of rain is expected, and in Gyeongsang, 30-80mm (over 100mm in some places) is anticipated, indicating significant rainfall in the southern regions.
The Korea Meteorological Administration anticipates more than 100mm of rain over mountainous areas and along the coast, suggesting there is a high possibility of issuing warnings for heavy rain, strong winds, and marine wind waves. Additionally, from the 17th to the 20th, during a period known as a ‘supermoon’, when the Earth and the Moon are closest, sea levels are higher, raising concerns about coastal lowland flooding due to the heavy rain.
Meteorologist Kim Young-jun warned, “Areas with intense rainfall could experience thunderstorms and gusty winds, and coastal areas may not drain properly during high tides, so precautions should be taken to prevent weather-related damage.”
The morning of Sunday the 20th is expected to see a significant temperature drop nationwide after the rain ceases. In Seoul, the morning low is forecasted to drop to 9 degrees Celsius, with daytime temperatures rising to 19 degrees, resulting in a temperature difference of over 10 degrees.
The concern is the possibility of icy roads, particularly in mountain areas. The Korea Meteorological Administration predicts that in mountain regions, where substantial rain falls, morning lows will fall below 3 degrees Celsius and possibly down to 0 degrees, creating conditions for ice formation. Woo Jin-kyu, a spokesperson for the meteorological administration, advised, “Many may plan outings to enjoy autumn or engage in sea leisure activities this weekend, but given the anticipated hazardous weather, extreme caution is advised.”
The drastic weather change over the weekend is attributed to cold air from the north meeting warmer-than-average temperatures. This meeting point forms strong rain clouds, explaining the forecasted heavy rainfall leading to potential heavy rain warnings.
Analyst Kim explained, “The temperature around the Korean Peninsula has remained high due to clear weather, resulting in sudden cold temperatures that could cause the morning of the 20th to feel even colder.”
Lee Jae-jung, forecast team leader at private weather analysis company K-Weather, noted, “Today in Seoul, the maximum temperature reached 25-26 degrees Celsius, which is over 5 degrees higher than average, making it a very hot day. It is typical for temperatures to rise on clear days and fluctuate widely as cold air moves in, a characteristic of autumn. However, if temperatures remain above normal, the fluctuations in autumn weather will be more pronounced.”