A blue alert for heavy rain across China's southern regions remained in place on Sunday. The National Meteorological Center (NMC) said heavy rain is expected in some parts of Guangxi, Guangdong, Hunan, Jiangxi, Fujian, Guizhou and Chongqing from Sunday to Monday morning. Precipitation in some areas of Guangxi and Guangdong is likely to reach 100 to 140 mm, and some affected regions will experience thunderstorms and hail, said the NMC. The center informed local authorities to step up preparatory work against floods, landslides, mud-rock flows and waterlogging. China uses a four-tier, color-coded weather warning system, with red representing the most severe weather, followed by orange, yellow and blue.