Thailand: Adverse weather forecast across much of the country through at least Nov. 30

Severe weather is forecast across much of Thailand through at least Nov. 30. The Thai Meteorological Department has issued a weather advisory warning of heavy to very heavy rain in most of the lower South through Nov. 30; flash floods are possible, especially on slopes near waterways and lowlands. Waves of around 2 meters (6.6 feet) are likely in the upper Gulf of Thailand and the Andaman Sea. The lower Gulf of Thailand will have waves of 2-3 meters (6.6-10 feet). Waves are likely to be larger in areas of thunderstorms. Vessels should proceed with caution and avoid sailing in areas with thunderstorms. Small vessels in the lower Gulf of Thailand should refrain from leaving the shore through Nov. 30. Strong winds, hail, and possible lightning may accompany storms. Strong winds may cause property damage and power outages in parts of the affected area.

The weather will be cool to cold, with strong winds across the upper part of Thailand. Temperatures in the North and Northeast regions will drop by 2-5 C (3.6-9 F) and 1-3 C (1.8-5.4 F) in the East and Central regions, including Bangkok and its vicinity. Due to the dry weather and strong winds, residents should be vigilant for any wildfires that may start.

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.