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

As of 5 pm Sunday, the typhoon was located over waters off the west coast of Luzon Island, the Philippines, with maximum winds of 72 km per hour near its center, according to the National Meteorological Center (NMC).

The typhoon is expected to move northwestward at 25-30 km per hour while gradually intensifying. From Tuesday onward, it will steer southwestward over the central and northern parts of the South China Sea, heading towards Vietnam's central coast before gradually weakening, according to the observatory.

ALSO READ: 8 killed, 2 missing as tropical storm Fengshen slams Philippines

Fengshen is currently classified as a tropical storm, with maximum sustained winds of 23 meters per second and its wind field extends 220 to 280 kilometers from the center. It is expected to move northwest at a speed of 20 to 25 kilometers per hour, gradually intensifying to a severe tropical storm or even a typhoon, with wind speeds reaching 30 to 35 meters per second.

By Tuesday, the storm is predicted to turn southwestward due to a cold front, heading towards the central coast of Vietnam and weakening as it approaches.

Over the next three days, Fengshen will bring heavy rain and strong winds to eastern and northern Taiwan, the coastal areas of Fujian province and Guangdong province, Hainan Island, and the northern part of the South China Sea.

Meanwhile, a cold front will continue to affect central and eastern China, causing temperatures to drop by 4 to 6 C in these regions, as well as parts of Guizhou province and Yunnan province. Some areas might see a temperature drop of up to 8 C, with the "0 C line" pushing southward to central North China.

Due to the combined effects of the cold front and Typhoon Fengshen, from 8 am Monday to 8 am Tuesday, the southern East China Sea, Taiwan Strait, and northern and central South China Sea are forecast to experience winds of up to 28.4 m/s, with gusts of 36.9 m/s, the center said, issuing a yellow alert for strong winds. And northern Taiwan is expected to experience heavy to torrential rain, with some areas receiving 100 to 200 millimeters of rainfall, according to the center.

READ MORE: HK mulls raising T3 on Monday night; mercury may touch 19°C Tuesday

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.

China's National Meteorological Center issued a blue alert for Typhoon Fengshen on Monday morning, as the 24th typhoon of the year continues to strengthen over the South China Sea. As of 5 am, the storm's center was located approximately 520 kilometers east of Sansha city, Hainan province.