The storm, the fifth one formed off the nation's coast this year, was around 500 kilometers to the east of Binh Dinh and Ninh Thuan Provinces on Tuesday night, carrying winds of 60-75 km per hour, the National Center for Hydro - Meteorological Forecasting.

In the next 24-48 hours, the storm is expected to move west northwest toward the mainland, with winds of 60-90 kph.

On Wednesday evening, it will come close to the south-central coast, threatening Binh Dinh, Phu Yen, Khanh Hoa and Ninh Thuan Provinces. The area is home to beloved beach towns including Quy Nhon and Nha Trang.

The storm is forecast to make landfall in the area that night before weakening into a tropical low in Cambodia.

Due to a combination with a cold wave, the south-central and Central Highlands regions will receive heavy rains and face the threat of landslide, flash floods and severe flooding.

Rainfall of 300-600 mm each time should be expected in the area on Wednesday and Thursday, the weather forecast center said. Rainfall of 180 mm a day is considered heavy.

The Japan Meteorological Agency has also forecast the storm will come closer to Vietnamese south central shore on Wednesday with wind speed of around 83 kph. The Hong Kong Observatory predicted that it will become a low pressure area over Cambodia on Thursday.

In an urgent statement released Tuesday's afternoon, Deputy Prime Minister Trinh Dinh Dung requested local authorities in all provinces in the affected area to get themselves prepared with sailing ban and evacuation plans.

Vietnam is hit by up to 10 tropical storms during the monsoon season, between July and October.

The country was struck by nine storms last year. Storm Podul hit central provinces in August, killing six people.