Authorities released a warning of possible urban flooding, flash floods and landslides in mountainous areas.
According to the National Center for Hydro-Meteorological Forecasting, a large-scale rain system began affecting many localities in the Northern region, including Hanoi, and the North-Central region from the night of May 19.
Areas experiencing rainfall include the Northeastern region, the southern parts of Phu Tho Province, Thanh Hoa and Nghe An. These areas are forecast to see cloudy skies with moderate to heavy rain, while some locations may experience very heavy downpours.
Mr. Mai Van Khiem, Director of the National Center for Hydro-Meteorological Forecasting, said that the widespread rainfall across the Northern and North-Central regions is expected to continue through May 21, with the heaviest rain concentrated between May 19 and May 21.
From May 20 to May 21, the Northeastern region, southern Lao Cai, southern Phu Tho, Thanh Hoa and Nghe An are forecast to receive rainfall of 50-120mm, with some places exceeding 250mm.
Total rainfall during the weather event is expected to range from 50-150mm, while some areas could record more than 300mm. Meteorological authorities warned that rainfall intensity may surpass 100mm within three hours, increasing the risk of localized flooding in urban areas and industrial zones.
Weather experts said that the heavy rain is being caused by an upper-level wind convergence zone combined with strong southeast winds.
Mountainous provinces such as Tuyen Quang, Thai Nguyen, Quang Ninh and Phu Tho have been warned of possible flash floods along small rivers and streams, as well as landslides on steep slopes due to prolonged rainfall.
Meanwhile, in Ho Chi Minh City and the Southern region on May 20, the weather is expected to feature intermittent sunshine with temperatures ranging from 31 degrees Celsius to 34 degrees Celsius. However, showers and thunderstorms are likely in the late afternoon and evening as the southwest monsoon gradually strengthens. Some areas could experience heavy rain with precipitation ranging from 10-30mm and locally exceeding 50mm.
Other Northern regions and areas stretching from Ha Tinh to Lam Dong are also forecast to experience scattered showers and thunderstorms during the day and night of May 20, with some places receiving rainfall of up to 80mm, mainly in the afternoon and evening.
