Vietnam: Adverse weather forecast across much of the country through at least May 19

Event

Heavy rainfall and thunderstorms are forecast across much of Vietnam through at least May 19. Strong winds, lightning, hail, and possible tornadoes will likely accompany storms. As of May 9, the Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) issued a warning for severe weather across northern, central highlands, south-central, and southern regions. Daily rainfall totals of 2-5 cm (0.8-2 inches) with isolated totals of over 7 cm (2.8 inches) are forecast across south-central, central highlands, and southern regions May 9-11. Rainfall totals of 1-3 cm (0.4-1.2 inches) with isolated totals of more than 5 cm (2 inches) are expected in northern regions on May 10. The NCHMF has issued a level 1 warning of natural disaster risk due to tornadoes, lightning, and hail in the affected regions.

Further moderate-to-heavy rainfall and thunderstorms are forecast in northern and central regions May 11-14, with the most severe weather likely May 11-12. Scattered showers and storms are likely in the central highlands and southern regions May 11-13 and May 18-19. Officials could update and extend the coverage of weather alerts over the coming days.

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 that lack or have easily overwhelmed 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 heavy rainfall has saturated the soil. 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 cancelations at airports in affected regions. Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancelations are possible in areas with 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)