Forecast is for widespread heavy rain - Bangkok Post

Motorcyclists navigate a flooded section of the Laharn Sai–Non Din Daeng road in Samrong Mai, Lahan Sai district, Buri Ram, on Thursday. (Photo: Surachai Piragsa) Heavy to very heavy rain is forecast for 42 provinces and Bangkok throughout Sunday into Monday, with flash-flood, forest runoff and landslides warnings in vulnerable areas.

The Meteorological Department said on Sunday morning some areas of the eastern and southern regions could experience heavy to very heavy rain, along with parts of the Northeast, Central Plains and Greater Bangkok.

People living near hillsides, waterways and low-lying areas were advised to exercise caution as heavy and accumulated rainfall could trigger flash flooding, runoff and mudslides. Motorists should try to avoid routes known for recurrent flooding, particularly low-lying roads. 

The weather pattern is being driven by a high-pressure system, a cool air mass extending over the upper North and upper Northeast. At the same time, a monsoon trough lying across the lower Central region, the upper South, the upper Gulf of Thailand and the East is linking with a strong low-pressure area off the central coast of Vietnam.

A moderate southwest monsoon continues to prevail over the Andaman Sea, the South and the Gulf of Thailand.

At sea, conditions are expected to remain moderately rough. Waves in the upper Andaman Sea are forecast around two metres and higher in thundershower areas. Mariners in the Andaman Sea and Gulf of Thailand are advised to proceed with caution and avoid thunderstorms.

For the period from 6am Sunday to 6am Monday, thunderstorms are forecast for about 70% of Bangkok and neighbouring provinces. Similar coverage is expected across the Central and Eastern regions, while thunderstorms could affect up to 80% of the South.

Northeast: Nakhon Phanom, Sakon Nakhon, Mukdahan, Yasothon, Kalasin, Khon Kaen, Chaiyaphum, Nakhon Ratchasima, Maha Sarakham, Roi Et, Amnat Charoen, Surin, Si Sa Ket and Ubon Ratchathani.

Central region: Lop Buri, Saraburi, Kanchanaburi, Ratchaburi, Samut Songkhram, Samut Sakhon, Bangkok and surrounding provinces.

East: Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Rayong, Chanthaburi and Trat.

South: Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Songkhla, Yala, Phuket, Krabi, Trang, Satun, Ranong and Phangnga.

The Meteorological Department also said a strong low-pressure area off central Vietnam is expected to intensify into a tropical cyclone and move closer to northern Vietnam by Monday.