The National Centre for Hydro-Meteorological Forecasting said the heaviest rain would fall in the northeast and Thanh Hoa Province from Thursday night to Saturday, with widespread rainfall of 100-200 mm. Northeastern areas could receive 150-250 mm, with isolated locations exceeding 350 mm.
Rainfall is expected to intensify from Friday night into Saturday, with parts of the northeast forecast to receive 120-180 mm and some areas more than 250 mm.
The storm, which strengthened from a tropical depression, is also expected to bring thunderstorms, lightning, hail and strong winds. Forecasters warned that rainfall could exceed 100 mm within three hours in some areas.
Authorities warned of a high risk of flash floods, landslides and flooding in low-lying urban and industrial areas. The natural disaster risk level has been set at Level 1.
