BEIJING, May 5 -- China's meteorological authority on Friday renewed a blue alert for severe convection weather in some southern areas.

From Friday afternoon to Saturday afternoon, thunderstorms, gales and hail will strike parts of Hunan, Jiangxi, Chongqing and Guizhou, according to the National Meteorological Center.

Short and heavy rainfall marked by 20 mm to over 60 mm of hourly precipitation will lash parts of Shanghai, Hubei, Hunan, Jiangxi, Zhejiang, Fujian, Chongqing, Guizhou and Guangxi, the center said.

The center has advised the public to take precautions against flash floods, landslides and mudslides, and has recommended reducing outdoor activities. Vessels operating in or transiting affected waters should return to port or take detours.

China has a three-tier, color-coded weather warning system for severe convection weather, with orange representing the most severe warning, followed by yellow and blue.