Northern Vietnam, Thanh Hoa and Nghe An are expected to face a new spell of torrential rain from the night of May 19 through May 21, with some areas forecast to receive more than 250mm of rainfall.

According to the National Center for Hydro-Meteorological Forecasting, scattered showers and thunderstorms were already recorded across many regions nationwide on May 18 ahead of the incoming downpour.

Rainfall measured between 7am and 3pm exceeded 70mm at several monitoring stations.

Notable figures included 72.4mm in Cao Bo, Tuyen Quang Province; 79.6mm at Khe Mo Rang Forest Ranger Station in Hue City; 90.2mm at Savin Forest Management Board in Khanh Hoa Province; and 227mm in Krong No, Dak Lak Province.

Forecasters warned that dangerous weather conditions are likely to intensify in the coming days.

From the evening of May 18 through May 19, weather patterns are expected to vary significantly across regions.

The northeastern region, Thanh Hoa and Nghe An are forecast to experience moderate to heavy rain and scattered thunderstorms, with rainfall ranging from 20mm to 40mm and some locations exceeding 100mm.

Meanwhile, the northwestern region, provinces stretching from Ha Tinh to Lam Dong, and southern Vietnam are also expected to see scattered showers and thunderstorms, with rainfall between 10mm and 30mm and isolated areas exceeding 80mm.

Rainfall in these regions is expected mainly during the late afternoon and nighttime.

Meteorologists said the most concerning period will begin from the night of May 19 through May 21, when northern Vietnam, Thanh Hoa and Nghe An could experience widespread heavy rain totaling 60mm to 120mm, with extreme local rainfall surpassing 250mm.

Experts warned that rainfall intensity could exceed 100mm within just three hours, raising the risk of severe urban flooding and inundation in low-lying areas.

As the heavy rain follows several days of hot and humid weather, thunderstorms may also bring dangerous conditions such as tornadoes, lightning strikes, hail and strong winds.

Authorities also warned of flash floods along small rivers and streams, as well as landslides in mountainous areas.

Residents living in mountainous and flood-prone regions have been advised to prepare response plans to protect lives and property.

Bao Anh