A northwesterly wind carrying yellow dust from China and Mongolia is descending on the Korean Peninsula, prompting an unusual cold wave advisory in April.
The Korea Meteorological Administration said it will issue a cold wave advisory for the southern mountainous areas of Gangwon, and for Gongju and Geumsan in South Chungcheong, and Muju in North Jeolla, effective 9 p.m. on the 20th. As cold air quickly moves south from the northwest, morning lows will drop by more than 10 degrees from the previous day.
This cold wave alert is the latest on record since one was issued in July 2005. The previous record was April 13, 2021. By region, the southern mountainous areas of Gangwon and Muju last saw it this late on April 13, 2021; Geumsan, on April 11, 2023; and Gongju, on March 21, 2019.
A cold wave advisory is issued when the morning low falls by more than 10 degrees from the previous day to 3 degrees or lower, and is also expected to be at least 3 degrees below normal. It is also issued when cold of 12 degrees below zero or lower continues for two days or more, or when damage is feared due to a sudden temperature drop.
Behind the cold wave alert is the recent stretch of abnormal warmth. Since the 13th, high pressure has settled over the skies of the Korean Peninsula and a southeasterly wind has flowed in, keeping daytime temperatures about 10 degrees above normal. Afterward, as cold air flowed in on northwesterly winds, temperatures plunged by more than 10 degrees in a day, meeting the criteria for issuing a cold wave alert.
As a result, on Tuesday the 21st, temperatures will be 2–11 degrees in the morning and 16–22 degrees during the day, similar to normal (lows 5–11 degrees, highs 17–22 degrees). However, as cold air flows in from the northwest, the morning wind chill will feel chilly, and the temperature difference between day and night will widen to around 15 degrees.
Yellow dust will also arrive on the northwesterly winds. As yellow dust that originated in the Gobi Desert and the Inner Mongolia Plateau on the 18th moves to the Korean Peninsula, fine dust levels nationwide are forecast to be at "very bad" levels on the 21st. Concentrations of fine particulate matter (PM10) and ultrafine particulate matter (PM2.5) are both expected to be high.