beijing, july 16 (xinhua) -- strong downpours and thunderstorms are expected to sweep south china over the coming three days, the national meteorological center (nmc) forecast monday.

the storms will hit hardest in regions south of the yangtze river, including the provinces of guizhou, hunan, jiangxi and guangxi, where precipitation is expected to surpass 200 mm within a 24-hour period, the nmc said.

some areas in northwest china, including the inner mongolia autonomous region, will be pounded by thunderstorms or hail, the observatory said.

the center maintained a rainstorm alert this morning, as heavy rains or rainstorms are expected to hit regions in zhejiang, jiangxi, hunan, guangxi, guizhou, yunnan and sichuan provinces.

nmc urged local authorities to prepare for floods in rain-soaked southern regions and take action to prevent possible rain-triggered natural disasters.

heavy rains in central and south china have killed dozens and forced thousands to evacuate in recent days.

rainstorms have left at least 11 people dead and damaged the homes of 980,000 residents in guizhou, while floods have killed eight people and affected over 2 million others in hubei. anhui and hunan provinces have also been hit hard by heavy rains over the past few days.