Vietnam: Adverse weather forecast across southern and central regions through at least May 9 /update 2

Event

Adverse weather, including heavy rainfall, thunderstorms, strong winds, and possible lightning, hail, and tornadoes, is forecast across parts of southern and central Vietnam through at least May 9. The Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) has warned of showers and thunderstorms in Southern Vietnam and the southern Central Highlands region May 9, with the heaviest rain in the afternoons and evenings. Forecast models indicate heavy to very heavy rainfall of 3-6 cm (1-2.5 inches) with isolated accumulations of over 8 cm (3 inches) May 5. Thunderstorms may be accompanied by strong winds, lightning, hail, and possible tornadoes. There is a risk of flash floods and landslides in mountainous provinces of the central highlands, as well as flooding in low-lying areas across the affected regions. The NCHMF has issued a level 1 warning of natural disaster risk due to tornadoes, lightning, and hail.

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, including but not limited to Tan Son Nhat International Airport (SGN). 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)