Widespread downpours are forecast to hit northern Vietnam between September 24 and 25. Meanwhile, the East Sea could see two storms form in succession.

On the afternoon of September 17, the Southern Hydrometeorological Center (under the National Center for Hydrometeorology) issued a forecast outlining key weather patterns likely to affect the region over the next 10 days.

In the next one to two days, a tropical convergence zone stretching across south-central Vietnam will connect with a low-pressure area over the central East Sea, moving northwestward toward the central coast. Simultaneously, a tropical depression north of Luzon Island (Philippines) is expected to enter the East Sea and possibly intensify. The southwest monsoon will maintain moderate intensity.

From days 3 to 10, the tropical convergence zone will shift northward to central Vietnam and strengthen. It will continue linking with a low-pressure area in the central East Sea and a tropical depression in the northern East Sea, all moving west-northwest toward Vietnam’s central coast.

By around September 23 to 24, a storm currently east of the Philippines is expected to enter the East Sea. Meanwhile, a subtropical high over northern Vietnam will extend westward and maintain stable intensity. The southwestern monsoon will weaken slightly from around September 20 to 21.

According to Vietnam's National Center for Hydrometeorological Forecasting, the tropical depression near Luzon will likely enter the East Sea tonight (September 17) and could strengthen into Storm No. 8 shortly thereafter.

Thus, in the coming week, the East Sea may see two storm systems: one forming from the tropical depression tonight and another potentially emerging around September 23 to 24.

Widespread rainfall in the North until the end of September

The National Center for Hydrometeorological Forecasting has also released a 10-day outlook (September 17–27) for mainland Vietnam:

From September 17–19:

Northern Vietnam will see scattered showers and thunderstorms, with some areas experiencing heavy rain, especially at night and in the morning.
From Thanh Hoa to Hue: scattered showers and thunderstorms, with localized heavy rainfall.
From Da Nang to Lam Dong and the southern region: moderate to heavy rainfall in the afternoon and evening, with some areas experiencing very heavy rain.

From September 19–27:

In northern Vietnam, rain will continue on the night of September 19. From September 22–23, moderate to heavy rain and thunderstorms are expected. Widespread heavy rain is likely between September 24–25.

From Thanh Hoa to Ha Tinh: scattered rain and thunderstorms, with localized heavy rain especially on September 19 and from September 22–23. Widespread heavy rainfall may occur from September 25 onward.

From Quang Tri to Hue: scattered rain and thunderstorms, especially in the late afternoon and evening.

From Da Nang to Lam Dong and the south: scattered afternoon and evening showers and thunderstorms, with localized heavy rain.

The forecast also indicates that Hanoi may experience showers and thunderstorms from September 18–19 and again from September 22–27, with some days seeing heavy rainfall. Temperatures in the capital will range from lows of 22°C to highs of 35°C. Notably, only September 20 and 21 are expected to be hot and sunny.

In Ho Chi Minh City, the Southern Hydrometeorological Center forecasts moderate to heavy rain with thunderstorms over the next two days, with localized very heavy rain. Total rainfall is expected to range from 40 to 90 mm, possibly exceeding 90 mm in some areas.

Rain will persist for another two to three days, with total rainfall between 80 to 140 mm, and some areas potentially exceeding 150 mm. Rainfall is expected to taper off starting September 20.

Potential hazards

The forecast warns of strong winds, lightning, hail, and localized tornadoes during thunderstorms. Heavy downpours may also lead to flash floods in small rivers and streams, landslides on steep terrain, and flooding in low-lying areas.

The meteorological agency advises that unpredictable weather patterns will persist through the end of 2025. Authorities and residents are urged to follow weather bulletins closely - especially short-term warnings - to ensure safety for both people and property.

Bao Anh