'Plum rain' season forecast to bring normal to below normal amount of rain: CWA

Taipei, April 30 (CNA) The rainfall during the upcoming "plum rain" season in Taiwan is expected to be normal or below normal this year, though it will likely be more concentrated during certain periods of time, the Central Weather Administration (CWA) predicted Tuesday.

Speaking at a press conference, CWA Weather Forecast Center director Chen Yi-liang (陳怡良) said Taiwan had a better chance of experiencing a normal amount of rain to a below normal amount during this year's plum rain season -- a period of sustained rainfall from May to June.

Based on CWA data from 11 weather stations compiled from 1991 to 2020, Taiwan gets an average 128.6-240.5 millimeters of rainfall in May and 180.1-326.4 mm in June. Combining the two months, the rainfall ranges between 393.3 mm and 523.5 mm during the May-June period.

Although the amount of precipitation over the two-month period has not significantly increased or decreased in recent years, the rain has become more concentrated in smaller time frames because of the higher frequency of brief spurts of heavy rain, Chen said.

El Niño is now weakening and is expected to become a La Niña this summer, Chen said, but its impact on Taiwan cannot be judged for certain yet.

Temperature-wise, he projected that it was more likely for the weather during this year's plum rain season to be "normal" or "warmer than usual."

In a separate Facebook post Tuesday, however, Cheng Ming-dean (鄭明典), former head of the weather agency, said the average temperature in the tropical zone has been higher than normal since May 2023.

As such, Taiwan has seen record temperature highs almost daily since June 2023, Cheng said.

The global average temperature continues to record new historical highs, which can be attributed to unusually high ocean temperatures, he said, noting that its effect on Taiwan will continue to be monitored by the CWA.

In related news, a text-based mobile alert system will be officially launched on Wednesday to warn people of flash floods after heavy rainfall is observed in Taiwan's mountains.

According to the CWA, the system will issue warnings when there is a storm upstream or in the mountains nearby, as a sudden surge of the river or stream often causes people to be trapped in the riverbed or swept away.

This mobile alert system, which was put to the test in a trial carried out last year, will cover a total of 24 stream areas in 11 cities and counties in Taiwan.