Vietnam: Adverse weather forecast across much of the country through at least April 18

Event

Heavy rainfall and thunderstorms are forecast across much of Vietnam through at least April 18. Cold air and strong winds are also forecast in northern and central regions April 16-18. The Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) has warned of moderate to heavy rain and thunderstorms across northern regions April 15-18, with localized very heavy downpours. Moderate to heavy rainfall is forecast in central and southern regions April 14-16. Tornadoes, lightning, hail, and strong winds are also possible during thunderstorms. The NCHMF has issued a level 1 warning of natural disaster risk due to heavy rain, tornadoes, lightning, and hail.

Forecast models indicate rainfall amounts of 8-15 cm (3-6 inches) over northern regions, with localized amounts of over 15 cm (6 inches) in some areas. In the northern delta and north central areas 4-8cm (1.5-3 inches) of rainfall, with localized amounts of over 10 cm (4 inches) is forecast. In the south central, central highlands, and south regions rainfall amounts of 5-10 cm (2-4 inches) are expected, with localized amounts of over 12 cm (5 inches). Temperatures are forecast to drop in the north from April 16, particularly over mountainous areas, and in north central regions from April 17. Strong winds will also lead to rough sea conditions along the northern coastline from April 16.

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)