Vietnam: Adverse weather forecast across much of the country through at least May 30 /update 1

Event

Heavy rainfall and thunderstorms are forecast across much of Vietnam through at least May 30. Weather warnings have been issued for most of the country and disruptions are ongoing in northern provinces following recent heavy rainfall and landslides.

The Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) has warned of showers and thunderstorms in Northern Vietnam, especially over the mountainous and midland areas, through at least May 27. Moderate to very heavy rainfall is possible, especially in the evening and night. Thunderstorms with rainfall of 2-4 cm (0.8-1.6 inches) are forecast in the Central Highlands Region and the South May 26-30. During thunderstorms, there is a possibility of tornadoes, lightning, hail, and strong winds. Heavy downpours will bring a risk of landslides in mountainous areas and flooding in low-lying areas. NCHMF has issued a level 1 warning of natural disaster risk due to heavy rain, tornadoes, lightning, and hail.

Heavy rainfall in the northern and central provinces May 21-24 triggered flash floods and landslides in the region, resulting in casualties and disruptions. Authorities have confirmed two fatalities and four other injuries due to a landslide in northern Tuyen Quang Province May 24 as well as another fatality in northern Hoa Binh Province due to floodwaters on the same day. Another fatality was reported in central Quang Ngai Province due to a lightning strike. At least 317 houses and more than 19,000 hectares (46,950 acres) of crops have been damaged.

Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible where significant flooding, strong winds, or landslides impact utility networks.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather could also trigger flight delays and cancellations at airports across Vietnam. Authorities may temporarily suspend port operations or close beach fronts along the South China Sea if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Vietnam National Centre for Hydro-Meteorological Forecasting (Vietnamese)