From early Wednesday through the night, areas from Hue to Danang and eastern parts of provinces from Quang Ngai to Dak Lak are forecast to receive 70-150 mm of rain, with isolated totals exceeding 250 mm, according to the National Centre for Hydro-Meteorological Forecasting.
Khanh Hoa, Lam Dong and southern Vietnam are expected to see 40-80 mm, with some areas receiving more than 150 mm.
Heavy rain is also forecast to spread northwards. Areas from Ha Tinh to Quang Tri could receive 30-70 mm overnight, with isolated totals above 120 mm.
On Thursday, rainfall of 50-100 mm is forecast from Ha Tinh to Danang, with some areas exceeding 200 mm. Eastern areas from Quang Ngai to Dak Lak, along with Khanh Hoa, Lam Dong and the south, could receive 30-70 mm, locally above 100 mm.
The weather agency warned that rainfall intensity could exceed 100 mm within three hours in some areas, raising the risk of flooding in low-lying and urban areas, flash floods along small rivers and streams, and landslides on steep slopes.
Thunderstorms could also bring tornadoes, lightning, hail and strong winds. A level-one natural disaster risk warning has been issued for heavy rain and severe thunderstorms.
At sea, thunderstorms are forecast across the Gulf of Tonkin and waters from southern Quang Tri to Ca Mau, from Ca Mau to An Giang, the Gulf of Thailand and the central and southern East Sea. Strong gusts and waves exceeding two metres could pose risks to vessels.
