As of 7 a.m. Sunday it lay centered 260 km to the east of the region from Binh Dinh to Khanh Hoa provinces, and packed winds of 100 kph, the National Center for Hydro-Meteorological Forecasting said.
In the next 12 hours it would move west-northwest at 10-15 kph, it said.
In the next 24 hours Nakri would approach land over Binh Dinh, Phu Yen and Khanh Hoa provinces, with wind speeds of 8-9 on the Beaufort scale, before weakening into a tropical depression and moving further inland into Cambodia, the center stated.
The Hong Kong Observatory said Nakri would move towards Tuy Hoa Town as it approaches Vietnam, and weaken into a tropical depression above the Central Highlands on Monday.
The U.S. Naval Research Laboratory said the storm would be centered above the beaches of Phu Yen at around 1 a.m. Monday before moving inland west-northwest and weakening.
Rough seas should be expected in the western part of the East Sea, internationally known as the South China Sea, and along the coast in the region from Da Nang City to Khanh Hoa Province, with waves of four to seven meters, the National Center for Hydro-Meteorological Forecasting said.
Provinces from Thua Thien-Hue to Ninh Thuan and the Central Highlands would get heavy rains until Tuesday, with the precipitation measuring 100-300 mm. Rainfall of 180 mm in 24 hours is considered heavy.
Flooding and erosion are also expected in these areas.
Local authorities have planned to evacuate over 180,000 people living in areas vulnerable to flooding and erosion, the Central Steering Committee on Natural Disaster prevention said. Over 47,000 boats and ships have been warned of the storm’s progress and guided to shelters.
More than 250,000 soldiers, 2,300 vehicles and five rescue vessels have been deployed, the National Committee for Incident, Natural Disaster Response and Search and Rescue and the Ministry of Transport said.
More than one million students of provinces Khanh Hoa, Phu Yen, Binh Dinh and Quang Ngai have been allowed to stay at home on Monday.
Vietnam Airlines and Jetstar Pacific have canceled or delayed a number of domestic flights.
Central Vietnam, home to popular tourist destinations like Nha Trang and Quy Nhon, was hit by storm Matmo last month. It felled hundreds of trees, damaged many houses and caused widespread flooding in Phu Yen, Binh Dinh and Quang Ngai provinces.
Vietnam is hit by up to 10 tropical storms during the southwest monsoon between July and October. There were nine last year.