A tropical depression is likely to strengthen into a storm to hit central Vietnam this weekend.

At 7am on Thursday, the tropical depression was swirling around the area, about 180km north of Vietnam’s Song Tu Tay island in the East Sea, with winds gusting between 39-49kmh.

The tropical depression is forecast to move west and north-west at a speed of 15kph in the next 24 hours, and gain strength into a storm on Saturday, according to the National Centre for Hydro-meteorological Forecasting.

The storm accompanied by the ongoing cold air wave from the north will cause rough seas and heavy rain along the central coast of Vietnam in the coming days.

Torrential rain is forecast to fall again in central Vietnam for several days, starting on Thursday. Localities from Quang Binh to Khanh Hoa are expected to collect between 100-450mm of rain in the coming 24 hours.

Heavy downpours will trigger water levels in the major river system in the region to swell up to the third alert level.

Weather experts warned about a high risk of flash floods and landslides in mountainous areas and flooding in low-lying areas.