BEIJING — China's national observatory issued a blue alert for rainstorms on July 3, as heavy downpours are forecast to hit vast stretches of the country.

From the night of July 3 to the night of July 4, heavy rain and rainstorms are expected in the regions of Zhejiang, Anhui, Jiangxi, Hubei, Hunan, Chongqing, Sichuan, Shanxi, Shaanxi and Yunnan, the National Meteorological Center said.

Some of these regions will see up to 70 mm of hourly precipitation, accompanied by thunderstorms and strong winds, the center said, warning that some areas of Jiangxi and Anhui will experience downpours with up to 150 mm of daily rainfall.

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

The center advised local authorities to remain alert for possible flooding, landslides and mudslides, and recommended halting outdoor operations in hazardous areas.

Since June, continuous downpours have lashed large parts of southern China, and the waters of many rivers in the affected regions exceeded warning levels.

The Ministry of Water Resources has called for all-out efforts to prevent floods, and has dispatched teams to affected areas to facilitate flood prevention and control.