BEIJING -- China's national observatory on Wednesday issued a yellow alert for typhoon Fengshen, the 24th typhoon of the year, as it is expected to bring strong winds and heavy rain to parts of the country's southern regions.

As of 9 am Wednesday, it was located over the waters of the South China Sea, about 170 km west-northwest of Yongxing Dao of Sansha city, Hainan province, with maximum winds of 33 meters per second near its center, according to the National Meteorological Center (NMC).

Fengshen is expected to move southwestward at 10 km per hour. Its intensity will remain steady through Wednesday morning before gradually weakening. The typhoon will make landfall over Vietnam's central coast as a tropical storm on Thursday before weakening rapidly, said the center.

Affected by the typhoon, gales are forecast to affect areas including parts of the East China Sea, the Taiwan Strait, the Bashi Channel, the waters east of Taiwan, coastal regions of southern Zhejiang, Fujian, Taiwan and Hainan Island, and parts of the South China Sea, as well as the Beibu Gulf between 2 pm Wednesday and 2 pm Thursday, the NMC said.

Meanwhile, it said that some areas of Hainan Island and Taiwan may experience heavy rainstorms during the same period.

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