Over the next 12 hours, the system is forecast to move westward and dissipate, according to the national weather agency.
The remnants of Ragasa are expected to bring heavy rains averaging 80-180mm in northern Viet Nam as well as in Thanh Hoa and Nghe An Provinces, with rainfall of up to 300mm in some areas.
The forecast centre has issued flood warnings for low-lying areas, urban centres and industrial parks, adding that flash floods could occur on small rivers and streams.
Meanwhile, a new storm named Bualoi is developing over the waters east of the Philippines and is expected to enter the East Sea/South China Sea on September 26, becoming Viet Nam’s tenth storm this year.