Pham Phuong Chi, a forecaster at the National Center for Hydro-Meteorological Forecasting, provided the latest assessment of rainfall conditions nationwide on the evening of Sept. 17.

As a subtropical high-pressure system gradually extends westward and strengthens atmospheric convergence, heavy rain is forecast to continue across northern Vietnam’s midland and delta regions.

The areas expected to be most affected include Hanoi, Ninh Binh, Hung Yen, Bac Ninh and Phu Tho, as well as southern parts of Lao Cai, Son La, Tuyen Quang and Thai Nguyen provinces.

Rainfall is forecast at 40-80mm, with some locations receiving more than 150mm.

Forecasters said the heaviest rainfall is expected from the night of Sept. 17 through the morning of Sept. 18. Rain across northern Vietnam is likely to gradually ease from the afternoon of Sept. 18.

Other parts of the north are expected to experience scattered thunderstorms, with localized heavy rain.

Heavy rain spreads south toward Hue

While rainfall is forecast to ease in the north, heavy rain across central Vietnam is expected to persist and gradually expand southward.

Thanh Hoa and Nghe An are forecast to see the heaviest rainfall from the night of Sept. 17 through Sept. 18, with totals of 50-100mm and more than 180mm in some locations.

Rainfall in Thanh Hoa is expected to gradually decrease from the night of Sept. 18, while wet conditions will continue in Nghe An.

From the night of Sept. 18 through Sept. 19, areas stretching from Nghe An to Hue are forecast to receive 30-60mm of rain, with localized totals exceeding 100mm.

From the night of Sept. 19 through Sept. 20, rainfall from Ha Tinh to Hue is expected to decrease and become less widespread, with totals of 20-40mm and more than 80mm in some areas.

Weather authorities have warned that localized intense downpours could cause flooding in low-lying areas, cities and industrial zones.

Residents in affected areas have also been advised to remain alert to flash floods along small rivers and streams and landslides on steep slopes.

Meanwhile, the Southern Regional Hydro-Meteorological Center said an intertropical convergence zone combined with a low-pressure system moving southward would directly affect southern Vietnam from Sept. 18 to 24, bringing a significant increase in thunderstorms.

Thunderstorms are expected to develop earlier in the day, sometimes beginning in the morning. Rain is forecast to become particularly intense and widespread from around midday through the afternoon and evening, with moderate to heavy rainfall and very heavy downpours in some locations.

According to Vietnam’s Department of Dike Management and Natural Disaster Prevention and Control, as of 5 p.m. on Sept. 17, rain and flooding had killed three people in a landslide that struck Da Bac commune in Phu Tho Province that morning.

A further 16,310 homes had been flooded, while more than 22,499 hectares of rice fields and other crops were inundated or damaged.

Numerous irrigation facilities, schools and roads have also been affected by landslides and flooding, causing transport disruptions.

Bao Anh