La Nina to bring colder weather to Taiwan after New Year

反聖嬰現象將在新年後為台灣帶來更寒冷的天氣

Fall and early winter in Taiwan will be dry and warm, but La Nina will bring colder temperatures in January


TAIPEI (Taiwan News) — The Central Weather Bureau (CWB) on Tuesday (Nov. 25) predicted that for the remainder of this year, Taiwan will see unseasonably dry and warm weather, but this will give way to colder conditions after the New Year due to the La Nina phenomenon.

On Tuesday, Lu Guo-chen (呂國臣), head of the CWB's Weather Forecast Center, told reporters that December will be warmer than usual, but starting in January, temperatures will drop to below average. Lu said that that La Nina, the cold counterpart to El Nino, will bring stronger northeast winds and colder temperatures from the start of the New Year and well into the spring.

Lu said that the country’s water supplies are tight, with rainfall from June to November of this year at only 60 percent of the average. Sun Moon Lake saw the lowest level since official measurements began in 1941.

September, October, and November only saw a total accumulation of 354.8 mm in precipitation, which was 277 mm less than the average and more than 40 percent less than the same period in previous years, according to Lu. The average temperature over this period was 25.9 degrees, which was 1.02 degrees higher than the average.

Lu Guochen said that the fall has had three major characteristics. First, there have been more tropical storms, with 13 formed between September and November, two more than the average of 11.03.

However, only Typhoon Atsani made landfall in Taiwan, and the rest mainly headed to Japan, South Korea, and the South China Sea. Second, the average temperature in Taiwan in the fall has so far been the third-highest ever recorded, behind 2017 and 2016.

Third, rainfall has been relatively sparse in most of western and eastern Taiwan. The only area that has seen a normal level of rainfall is northeastern Taiwan due to the effects of weather fronts and the periphery of tropical storms.

Lu said that Sun Moon Lake has only seen 86 millimeters of rainfall in the fall, less than 30 percent of the average for that period. Alishan has recorded the fifth-lowest amount of rainfall on record at only 240 mm, less than 40 percent of the average.

Some weather stations in western Taiwan, such as Tamsui, Taipei, Hsinchu, Wuqi, Chiayi, and Chenggong have all recorded rain levels that are well below average. The average accumulated rainfall in 13 weather stations has been less than 60 percent of the average.

Lu pointed out that the rainfall in May and August this year was higher than the average, while precipitation in June, July, and September was significantly lower than the average. The average rainfall from June to November was 902.5 mm, which was only 60 percent of the average and the lowest since 1993.

As for the winter weather, Lu said that the conditions this fall are unseasonably warm, but the La Nina phenomenon will begin to have an impact in January. Lu predicted that after the start of the New Year, winter temperatures will be lower and the northeast wind will be stronger than usual.

Regarding cold waves, Lu said that based on past data, the average number of days Taiwan is affected by a cold wave is 6.6. In recent years, global warming has caused the cold waves to diminish in length and intensity, but due to the presence this year of La Nina, cold waves should be stronger and longer-lasting than normal by the middle of the winter.

As for rainfall, Lu said that the Plum rains ended earlier this year, the fall has seen little in the way of precipitation, and there are no signs that there will be much in the way of rain from December through February. Therefore, he urged the public to take steps to lower their water consumption over the coming months.