Western Taiwan to see localized heavy rain Wednesday afternoon: CWA

Taipei, Sept. 2 (CNA) Unstable weather conditions are expected to prevail Wednesday with localized heavy rain possible in western Taiwan, particularly in the afternoon, according to the Central Weather Administration (CWA).

Speaking with CNA, CWA forecaster Chang Chun-yao (張竣堯) said the impact of an ongoing "cold core low pressure system" is expected to continue into Thursday with thunderstorms possible on Wednesday afternoon.

A cold-core low pressure system involves cold air residing at a high altitude within the Earth's troposphere and when it approaches the temperature difference between the warm surface and the upper atmosphere increases, prompting convective currents to develop that eventually lead to thunderstorms, according to the CWA.

On Wednesday morning only sporadic showers are likely in the west, Chang said.

Daytime temperatures are expected to range between 31-34 degrees Celsius across most of Taiwan Wednesday, while 35 degrees is possible in the Greater Taipei area and mountainous areas of central and southern Taiwan, he added.

On Thursday, as cloud cover depletes, temperature highs are expected to top 36 degrees, Chang said.

From Friday to Saturday, a Pacific high pressure system will strengthen, pushing up the mercury further as cloudy to sunny skies continue, with brief localized thunderstorms possible in the afternoons, the CWA said.

A cloud system is expected to start to move northwards on Sunday so the chance people in southern and eastern Taiwan will be able to observe the total lunar eclipse expected from late Sunday to early Monday morning is slim, Chang said, adding that people in the northern half of the country are likely to see part of the eclipse through cloud gaps.

Meanwhile, a tropical disturbance has formed near Okinawa and could be upgraded to a tropical depression Wednesday at the earliest and move in a northerly direction toward Japan, Chang said.

There is also a low pressure front east of the Philippines, which could bring moisture to Taiwan from Sunday to Tuesday, but more time is needed to determine whether it will develop into a tropical weather system, the forecaster said.