BEIJING — China's national observatory on Aug 23 renewed a blue alert for Typhoon Bavi, which is expected to bring gales to South and Southeast China.

The typhoon, the eighth of this year, strengthened from a tropical depression on Aug 22 morning and was observed at waters 390 km west of the city of Naha in Japan's Okinawa Prefecture at 5 am on Aug 23, with a maximum wind force of 100.8 km/h at the center, the National Meteorological Center (NMC) said.

The NMC expects the typhoon to move northeastward at a speed of 10 km to 15 km per hour as it strengthens, before heading towards Northeast China's Liaodong Peninsula from Aug 26.

From the morning on Aug 23 to the morning on Aug 24, gales are expected to hit some coastal areas of provinces and regions including Taiwan, Fujian and Zhejiang, according to the NMC.

The NMC advises people and vessels in disaster-prone areas to take shelter from winds.

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