TAIPEI (Taiwan News) — Rain brought by a weather front will cause daytime highs in north Taiwan to drop by 10 C on May Day (Wednesday, May 1), according to the Central Weather Administration (CWA). 

CWA forecaster Liu Yu-chi (劉宇其) on Tuesday (April 30) said the chance of rainfall will increase with thunderstorms expected in mountainous areas of Taipei and Yilan in the afternoon. Liu said the weather on Wednesday will become unstable and cooler, and the temperature difference could approach 10 C.

Starting Wednesday, there will be localized heavy rain for two days. Liu said Taiwan on Tuesday is in the midst of a weather transition, with the chance of rainfall increasing in the latter half of the day. 

Kinmen and Matsu will experience brief showers or thunderstorms on Tuesday, said Liu. As the front approaches, the rainfall area will expand, and the western and eastern regions will gradually transition to rainy weather patterns.

Liu said that Tuesday's temperatures are relatively high, ranging from 32 to 34 C across the country. There is also a chance of the foehn effect in Taitung. 

On Wednesday, highs of around 22 C could mark a temperature difference of approximately 10 C from the previous day. By Friday (May 3), the northeast monsoon is expected to weaken, leading to a gradual temperature increase.

There will be another weather front over southern China that is expected to pass by slightly to the north of Taiwan on Monday (May 6). Environment Minister-designate Peng Chi-ming (彭啟明) said on Facebook on Tuesday that there is a “lightning train” spanning over 1,000 kilometers in southern China, approaching Taiwan from late Tuesday to Thursday.

Liu said this weather front is vigorously developing over southern China, with moderate-scale convection and large thunderstorm cells accompanied by lightning. Taiwan's weather will become increasingly unstable in the following days, although not as severe.

Attention should be paid to the development of localized thunderstorms and sudden, heavy downpours, said Liu.