At 10 a.m. on Thursday, the storm lay centered around 1,545 km east of Luzon Island in the Philippines with maximum wind speed of 110 kph.

Hoang Phuc Lam, deputy director of the National Center for Hydro-Meteorology and Forecasting, said it is projected to enter the East Sea, internationally known as the South China Sea, on Sunday morning and continue gaining strength.

"The storm is likely to affect the central region next week. When entering the East Sea, the storm will combine with a cold spell and the situation will be complicated," Lam said.

Japan Meteorological Agency predicted the storm to reach wind speed of 129 kph on Thursday afternoon, while the U.S. Navy forecast the storm would reach maximum wind speed of 220 kph on Sunday.

International weather forecasting agencies all predict the storm would enter the East Sea and head to central Vietnam next week.

If Storm Goni enters the East Sea as forecast, Vietnam would have witnessed five tropical storms and one tropical depression within a month.

On Wednesday morning, Storm Molave made landfall over central Quang Nam and Quang Ngai provinces, causing torrential downpours, strong winds, and landslides. It was the fourth storm to affect central Vietnam this month, following Linfa, Nangka and Saudel.

As of Thursday afternoon, Storm Molave has killed at least 18 people, 17 in Quang Nam due to three separate landslides and one in Gia Lai Province in the Central Highlands who was crushed by a collapsing wall.

Torrential downpours and discharge of water from hydropower dams have caused rivers in Quang Nam and Quang Ngai provinces to swell and severe flooding has been forecast.

The central region had just been hit by prolonged heavy rains, which triggered historic flooding and deadly landslides between October 6 and 25 that caused at least 130 deaths.