China's national observatory on Wednesday issued a red alert, the highest warning level, as typhoon Muifa is expected to make landfall twice later in the day.

The China Meteorological Administration also upgraded the typhoon emergency response to Level II, the second-highest, reports Xinhua news agency.

Muifa, the 12th typhoon this year, was observed over the ocean 185 km southeast of Xiangshan county in Zhejiang province at 10 a.m. Wednesday.

It is expected to move northwestward at a speed of 20 to 25 km per hour, the National Meteorological Centre said in a statement.

The typhoon will make the first landfall in coastal areas between Sanmen county and Zhoushan city in Zhejiang around nightfall.

It will make the second landfall in coastal areas between Jiaxing city in Zhejiang and Shanghai's Pudong district on Wednesday evening.

Shanghai, Jiangsu, Zhejiang and Shandong are expected to experience gales and downpours from Wednesday to Thursday afternoon, according to the forecast.

The Centre has advised the aforementioned regions to make emergency preparations for the typhoon and to take precautionary measures against possible geological disasters, while ships and boats have been asked to take shelter in harbours.

China has a four-tier colour-coded system for severe weather, with red being the most serious, followed by orange, yellow and blue