Typhoon Narra shifts course, moves toward waters east of Bach Long Vi as Vietnam braces for heavy rain and rough seas

What happened

Typhoon Narra, described as the fourth typhoon to affect Vietnam this year, has changed course and is heading southeast toward waters east of the Bach Long Vi special zone in northern Quang Ninh province, according to the National Centre for Hydro-Meteorological Forecasting. As of 1:00 pm on August 23, the storm's centre was about 155 km east-southeast of Quang Ninh province and 150 km east of Hai Phong city, with sustained winds of force 8-9, gusts of force 10-11, and movement southeast at about 3 km/h.

The forecast center projected that by 1:00 pm on August 24, the storm would track south-southeast at around 3 km/h, with winds near the centre strengthening to force 9 and gusts reaching force 11. By 1:00 pm on August 25, it was expected to move east-northeast at 3-5 km/h over the eastern Gulf of Tonkin, about 160 km east of Bach Long Vi, with sustained winds of force 9 and gusts of force 11.

The Gulf of Tonkin — including the Bach Long Vi, Van Don, Co To and Cat Hai special zones and Hon Dau island — along with coastal areas of Quang Ninh and Hai Phong, will be affected, with the disaster risk level forecast at Level 3. Sea conditions will feature waves 2-4 metres high and winds of force 6-7, rising to force 8-9 near the storm centre, threatening fishing, cargo and tourist vessels, aquaculture facilities and coastal infrastructure. Coastal areas of Quang Ninh and Hai Phong are expected to see winds of force 6 with gusts of force 8, which authorities said could damage roofs, uproot trees and disrupt power and transport systems. From the afternoon of August 23 through August 24, heavy rainfall of 30-70 mm, locally exceeding 150 mm, is forecast across the northeastern region, southern Phu Tho province and Thanh Hoa province, with higher rainfall of 60-120 mm, locally surpassing 250 mm, expected in Bac Ninh, Quang Ninh, Hai Phong, Hung Yen and Ninh Binh. Authorities warned the rainfall could cause urban flooding, flash floods and landslides in mountainous areas, with thunderstorms, whirlwinds and strong gusts also possible due to the storm's circulation, and said the heavy rain is expected to ease gradually from the night of August 24.

How it unfolded

Industry impact & what to watch

Narra belongs to a recurring category of Gulf of Tonkin storms that move slowly and unpredictably close to shore, giving forecasters only short windows to update tracks before conditions change. A storm holding near force 8-9 for multiple days, as this one is forecast to do through August 25, keeps coastal and offshore operators in a prolonged state of contingency rather than a single go/no-go decision.

In this region, aviation, port and fishing operations built around Hai Phong and Quang Ninh typically adjust schedules incrementally as the forecast center issues each new positional update, since a track shift of even a few dozen kilometres changes which zones fall inside the highest-risk radius. The Level 3 disaster risk designation and the specific special zones named — Bach Long Vi, Van Don, Co To, Cat Hai and Hon Dau — mark where marine and coastal activity restrictions are most likely to tighten first.

The next dated marker is the storm's forecast position at 1:00 pm on August 25, when it is expected to sit about 160 km east of Bach Long Vi; how closely the actual track matches that projection will determine whether the heavy rainfall and rough-sea warnings ease as forecast from the night of August 24 or extend further along the coast.