Vietnam: Adverse weather forecast across northern regions through at least April 25

Severe weather is forecast across much of northern Vietnam through at least April 25. As of April 23, the Vietnam National Center for Hydro-Meteorological Forecasting (NCHMF) has issued a warning for localized heavy rain and thunderstorms across northern regions and into Thanh Hoa and Nghe An provinces in north-central Vietnam. Strong wind gusts, lightning, hail, and possible tornadoes may accompany storms. Rainfall amounts of 1.5-3 cm (0.6-1.2 inches) with localized higher totals over 6 cm (2.4 inches) are likely in the region. Heavy downpours may trigger flooding in low-lying areas and landslides on unstable slopes. The NCHMF has issued a level 1 warning of natural disaster risk due to hail, tornadoes, and lightning.

Recent heavy rainfall, thunderstorms, and strong winds across northern Vietnam since April 19 have caused casualties and damage in the region. As of April 22, authorities have reported one fatality and eight others injured due to the severe weather across the region. Nearly 35,500 people have been affected by the severe weather across 11 northern provinces.

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 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 rain has saturated the soil. Disruptions to electricity and telecommunications services are possible where significant flooding, strong winds, or landslides impact utility networks.

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 in the affected regions. Flooding could block regional rail lines; freight and passenger train delays and cancellations 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.