The warning was issued at 2:30 p.m. for Keelung City, Taipei City, New Taipei County, Yilan County, Hsinchu County, Taoyuan, Miaoli County, Taichung, Hualien County, Nantou County, Yunlin County, Tainan, Kaohsiung, and Chiayi County.
People in those areas should also be on the alert for lightning and strong winds, as well as possible flooding caused by torrential rains, the CWB said.