Thailand: Adverse weather forecast across much of the country through at least Oct. 21

Severe weather is forecast across much of Thailand through at least Oct. 21. The Thai Meteorological Department has issued a weather advisory warning of thunderstorms, heavy rain, and strong winds in upper Thailand and continuous heavy to very heavy rainfall in southern Thailand. The heaviest rainfall is forecast over the eastern region and the eastern coast of the southern region. Waves of around 1 meter (3 feet) are forecast in the Andaman Sea and waves of less than 1 meter (3 feet) are likely in the Gulf of Thailand. Vessels should avoid areas with thunderstorms. Storms may be accompanied by strong winds, hail, and possible lightning. Strong winds may cause property damage and power outages in parts of the affected area.

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

Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel 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 intermittent flight delays and cancellations at airports across the affected region, though these are unlikely to be severe or prolonged. 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 cancellations are possible in areas with heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying areas.

Flooding could heighten the threat of disease outbreaks. Backflow from drains mixed with floodwaters can become trapped in open areas when inundations recede. These stagnant pools often become a breeding ground for mosquitoes and bacteria, increasing the incidence of insect- and water-borne diseases. Exposure to contaminated water from inundated industrial sites, sewer systems, and septic tanks also poses a significant health threat.