At 6 a.m. Friday the tropical depression over the East Sea this year was centered around 310 km off the south-central province of Binh Dinh.
It is forecast to move northwest and intensify into a storm, the fifth in the East Sea this year, according to the National Center for Hydrometeorological Forecasting.
Heavy rains and waves of up to six meters are forecast in the region, home to popular beaches.
Rainfall between Thursday and Monday could exceed 600 mm in some places between Quang Binh and Khanh Hoa provinces. In Quang Tri and Quang Ngai it could reach up to 800 mm.
The region was hit by Storm Noru in late September when thousands of houses were damaged and heavy rains flooded others.