Vietnam: Adverse weather forecast across much of the country through at least May 3

Event

Adverse weather, including heavy rainfall, thunderstorms, strong winds, and rough seas, is forecast across much of Vietnam through at least May 3. The Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) has warned that a low pressure area off southern Vietnam will possibly strengthen into a tropical depression from April 29 and bring showers and thunderstorms to south central Vietnam from Da Nang Province to Binh Thuan Province, the central highlands, and southern Vietnam. Rainfall accumulations of 5-10 cm (2-4 inches) are possible in these areas, with localized heavier downpours. Cold air compressing with a low pressure trough in northern Vietnam will also bring heavy rainfall and thunderstorms to northern regions from late April 30-May 1 and in north central Vietnam from Thanh Hoa to Thua Thien Hue provinces from early May 1-May 2. Rainfall accumulations of 4-7 cm (1.5-3 inches) with isolated amounts of over 10 cm (4 inches) are forecast in northern Vietnam and accumulations of 5-10 cm (2-4 inches) with isolated amounts of over 12 cm (5 inches) are expected across north central Vietnam.

Thunderstorms may be accompanied by strong winds, lightning, hail, and possible tornadoes. Rough seas and strong winds are also expected in coastal areas from May 1. The NCHMF has issued a level 1 warning of natural disaster risk due to heavy rain, tornadoes, lightning, and hail, and a level 2 warning for strong winds at sea.

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)