SHANGHAI, Aug. 2 (Xinhua) -- Jongdari, the 12th typhoon this year, is likely to make landfall in Shanghai Friday morning, the local weather station said Thursday.

At 3 p.m. Thursday, the eye of the tropical storm was 470 km offshore from Shanghai and was moving northwest at the speed of 25-30 kph, the municipal meteorological observatory said.

Rain and strong winds up to 20 meters per second are expected on Thursday evening and Friday morning in the city.

Shanghai raised its typhoon alert from blue to yellow, and in some districts, such as Pudong New Area, the alert was raised to orange.

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

Related departments have been asked to prepare for an emergency response.

In neighboring Zhejiang Province, 38 under-construction offshore projects were suspended in the city of Zhoushan, with over 160 ships involved in the construction evacuated, said Hu Yaowen, from the provincial flood control and drought relief headquarters.

In Jiaxing, floodgates at Changshan and Nantaitou started to discharge water in advance on Thursday afternoon to prevent typhoon-triggered flooding near Taihu Lake, Hu said.

Nearly 6,000 people living along the coast in the cities of Ningbo, Taizhou, Jiaxing, and Huzhou were moved inland, and some 20,000 fishery vessels were harbored or evacuated to safe water areas, according to the headquarters.