The storm lay centered 950 km east-northeast of the Paracel Islands at 4 p.m. on Sunday and is moving in the west-northwest direction at 15-20 kph, according to the National Center for Hydro-Meteorological Forecasting.

By 4 p.m. Monday, it will be 630 km northeast of the Paracels with maximum winds of 118 kph. By 4 p.m. Tuesday, it will be 270 km northeast of the islands and its wind speed may rise to more than 130 kph.

After that, it will move west-southwest at 15 kph and is likely to gain strength, according to the center.

Storm Nesat's forecast route towards north central Vietnam. Graphics by Vietnam Disaster Management Authority

Nguyen Van Huong, head of the center's weather forecast department, said there are three scenarios predicted for Nesat in the East Sea. The first case is the storm will meet a cold spell from the north and weaken off the central coast before devolving into a tropical depression upon making landfall. The second scenario is the storm will meet a weak cold spell before entering the central coast with winds of 75-102 kph. The third scenario is that it will move to the south of China's Hainan Island, meet a strong cold spell and weaken and break apart at sea.

Both the Japan Meteorological Agency and the Hong Kong Observatory said the storm will head for the central coast and make landfall in the north-central region. It said the storm will be strongest on Tuesday with the maximum wind speed of 145 kph.

Nesat makes the sixth storm in Vietnam's waters this year.

It arrives shortly after Storm Son Ca raged the central region, bringing rainfall of up to 795 mm from 7 p.m. Friday to 6 a.m. Saturday that caused .