Da Nang, Hue face flooding, landslide risks as Storm Fengshen threatens to dump up to 800 mm rainfall over 3 days

More than 150 communes across Hue, Da Nang and Quang Tri and Quang Ngai provinces face flooding and landslide risks as Storm Fengshen, weakened by cold air, nears the central coast with heavy rain and strong winds.

The Department of Meteorology and Hydrology on Oct. 22 said Fengshen’s winds are expected to peak at 102 kph and will not intensify upon nearing land, unlike past storms such as Bualoi and Matmo. As the system reached the Paracel Islands, cold air from the north slowed it down and forced it to change direction.

While the storm’s winds are not extreme, its circulation is drawing in large amounts of moisture from the East Sea, known internationally as the South China Sea, combining with strong northeasterly and easterly winds. This convergence, amplified by the Annamite Range, is expected to unleash prolonged heavy rainfall across central Vietnam, even after the storm dissipates.

Rainfall will come in two phases. From Oct. 22 night to Oct. 24, Quang Tri to Da Nang could see 400–600 mm of rain, with some areas exceeding 800 mm and downpours of over 200 mm within three hours. Ha Tinh and Quang Ngai are forecast to receive 100–250 mm, locally over 400 mm.

Mai Van Khiem, director of the National Center for Hydro-Meteorological Forecasting, warned that the first wave of rain poses a high risk of flooding in urban and industrial areas due to slow drainage caused by storm surges.

A second rain phase from Oct. 25–27 will bring another 200–300 mm to Quang Tri and Hue, with local totals surpassing 500 mm. Rainfall across the region from now until the end of October is expected to exceed the annual average by 20–40%.

Rivers in Quang Tri and Hue have already risen above flood alert levels due to earlier rain. From Wednesday night through Oct. 28, major rivers from Quang Tri to Quang Ngai are forecast to surge above Level 3 (highest level) flood alerts by 0.3–1.5 m, threatening widespread inundation.

Quang Tri faces the highest danger, with flash floods and landslides possible in 41 of 78 communes, and severe flooding risks in 40. In Hue, the Bo and Huong rivers are expected to rise 0.2–0.5 m above Level 3. Da Nang and Quang Ngai could see river levels up to 0.5 m above the highest alert threshold, putting dozens of low-lying wards and communes at risk.

Reservoirs in Hue and Da Nang remain below capacity, which could help mitigate flooding downstream. But meteorologists warn that the intensity and duration of rain, possibly 500–700 mm in total, could still overwhelm drainage systems and trigger flash floods in mountainous areas.

Formed east of the Philippines on Oct. 18, Fengshen entered the South China Sea on Oct. 19 and became the 12th storm of the year in the waters. It reached peak strength before slowing under the influence of cold air.

By Wednesday evening, the storm is expected to weaken as it moves over the waters off Hue–Quang Ngai, making landfall late Wednesday or early Thursday as a tropical depression before dissipating over southern Laos.

By Gia Chinh – VnExpress.net – October 22, 2025