Taiwanese meteorological experts have stated that the weather is improving today (20th) with temperatures gradually rising, but a cold air mass is expected to return to Taiwan over the weekend, reaching its coldest point on the 23rd. The Central Weather Bureau has indicated that on the 21st, another cold air mass from the mainland will move southward, causing temperatures to drop even further across the island, especially in the evenings, leading to colder conditions by the 23rd.
Associate Professor Wu Derong from the Department of Atmospheric Sciences at National Central University in Taiwan commented on the weather forecast program “Sanli TV Weather Insights” today. According to the latest European model (ECMWF) simulation from 8 p.m. on the 19th, the mid-level clouds are gradually moving away today, leading to partly cloudy skies in the western half of the island. There is a chance of sporadic short showers on the eastern side of Greater Taipei and in Yilan and Hualien. The cold air mass is weakening gradually, allowing temperatures to slightly rise, but mornings and evenings will still remain cold. The temperatures are expected to range from 10 to 19 degrees Celsius in the north, 10 to 23 degrees Celsius in the central region, 10 to 25 degrees Celsius in the south, and 10 to 24 degrees Celsius in the east.
Wu Derong further mentioned that the latest model simulations show that from the afternoon of the 21st to the early morning of the 23rd, a “mainland cold air mass” similar in intensity to the previous one will move southward, causing the weather to turn colder. Due to radiative cooling at night, mornings will see lower temperatures, with some areas on flat ground dropping below 10 degrees. The elderly and patients with cardiovascular diseases should take extra precautions to stay warm and maintain their health. On the 21st and 22nd, the western half of the island will experience partly cloudy skies, with sporadic short showers expected in the eastern side of Greater Taipei, Yilan, and Hualien.
Looking ahead to the period from the daytime of the 23rd to around Christmas on the 25th, the cold air mass will gradually weaken each day, causing temperatures to increase gradually. Clouds from the mid-level will move in from the west on the 23rd, leading to increased cloudiness in the central and southern regions, with occasional short showers expected in mountainous areas and the eastern half of the island. On the 24th and 25th, partly cloudy skies are anticipated in the western half, while there is a chance of sporadic short showers in the eastern half. A weak frontal system passing through on the 26th may slightly increase the chances of rain in the eastern side of Greater Taipei, Yilan, and Hualien, with no significant impact on other regions.
“There will be another frontal system passing through on the 27th, with an expanded range of rainfall,” Wu Derong stated. Looking further into the forecast, from the 28th until the end of the year, due to the long simulation period, there is considerable uncertainty with both European (ECMWF) and American (GFS) models fluctuating in terms of the strength of the cold air mass. Hence, it is advisable to patiently observe adjustments in the models without jumping to conclusions hastily, and not to overlook the limitations of science.
The Central Weather Bureau of Taiwan has issued a special advisory for low temperatures today, warning that on the morning of the 21st, in Miaoli County, Taichung City, Changhua County, Nantou County, and Hualien County, the effect of radiative cooling will keep temperatures low. There is a probability of temperatures below 10 degrees Celsius (yellow warning) in some areas on the morning of the 21st, so caution is advised.