Thailand: Adverse weather forecast across southern provinces through at least Dec. 5

Severe weather is forecast across much of southern Thailand through at least Dec. 5. As of early Dec. 2, the Thai Meteorological Department has issued a weather advisory warning that the low-pressure system in the lower South China Sea will move through the Gulf of Thailand and the lower South into the lower Andaman Sea, causing heavy rain in Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Phang Nga, Phuket, Krabi, Trang, and Satun provinces, and very heavy rain in some areas in Songkhla, Pattani, Yala, and Narathiwat provinces. Floods and flash floods are possible, especially in hilly terrain, lowlands, and areas near waterways. Waves of 1-2 meters (3.5-7 feet) are forecast in the upper Gulf of Thailand and Andaman Sea, while waves of around 2 meters (7 feet) are likely in the lower Gulf of Thailand. Waves of more than 2 meters (7 feet) are likely in areas with severe weather. Authorities have advised vessels to sail with caution and avoid thunderstorms. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

Flooding is ongoing in parts of southern Thailand following heavy rainfall in recent days. Flooding across eight provinces in southern Thailand has affected more than 640,000 households. Authorities have confirmed 12 fatalities and more than 13,000 people displaced across 200 emergency shelters. Two hospitals in Pattani Province suspended operations as a precaution. Floodwaters in Hat Yai City in Songkhla Provinces have receded.

Sustained heavy rainfall could trigger additional 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 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, 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. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see 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 waterborne diseases. Exposure to contaminated water from inundated industrial sites, sewer systems, and septic tanks also poses a significant health threat.