Nguyen Van Huong, head of the weather forecast department at the National Center for Hydro-Meteorological Forecasting (NCHMF), said Sunday that the low-pressure area the middle of the East Sea is moving towards the central region.
He said it is likely to strengthen and will cause even more severe rains for the region.
The region has entered the fifth day of heavy rain. According to the NCHMF, from 7 p.m. on October 10 to 7 a.m. on Sunday, Thua Thien-Hue, Da Nang and Quang Nam received rains of 400-600mm and more than 1,000 mm in some places.
One station in Da Nang recorded 1,050 mm rainfall over the 4.5-day period, while another in Thua Thien Hue recorded 1,005 mm.
For the past two days, many parts of Da Nang and Thua Thien Hue have been flooded, with some areas left 1.5m underwater, putting people's life in chaos.
By late Saturday, floods had killed two people - a man aged 61 in Thua Thien Hue and a 13-year-old boy in Ha Tinh. They also inundated 1,500 houses, mostly in Da Nang, damaged 67 hectares of crops and paralyzed traffic at hundreds of spots in Quang Binh, Thua Thien Hue and Da Nang.
Huong said it is the combination of a cold spell, a tropical convergence zone and the east wind monsoon that has resulted in such heavy rain for the central region.
In the upcoming days, the cold spell will grow stronger, and more rain should be expected. In the next three days, rains are forecast at 150-250mm in areas from Quang Binh to Binh Dinh provinces and up to over 400 mm in some places.
The volume is expected to reach 250-450 mm and more than 800 mm in Thua Thien-Hue, Da Nang and Quang Nam.
On October 16-18, the newly formed low-pressure area is forecast to reach the mainland, and the rain are will expand to the north-central region, which covers Quang Tri, Nghe An and Thanh Hoa provinces.