Flood risk rises with severe rain in Northeast and eastern Thailand

Bueng Kan and Nakhon Phanom are forecast to receive very heavy rain on Tuesday (August 18), while Bangkok and neighbouring provinces face thunderstorms across 60% of the metropolitan area, according to the Thai Meteorological Department (TMD).

Very heavy rain is also expected in Trat, while isolated heavy rain is forecast across parts of the North, Northeast and East during the 24-hour period from 6am on Tuesday to 6am on Wednesday.

Monsoon conditions raise flood risk

The unsettled weather is being driven by a monsoon trough moving southwards across upper Laos towards a low-pressure area over upper Vietnam.

At the same time, the southwest monsoon prevailing over the Andaman Sea, Thailand and the Gulf of Thailand is strengthening.

The TMD warned that heavy to very heavy and accumulated rainfall could cause flash floods, run-off and overflowing waterways, particularly on foothill slopes, near waterways and in low-lying areas.

Regional weather forecast

Bangkok and neighbouring provinces

• Thunderstorms across 60% of the area
• Minimum temperature: 25–28°C
• Maximum temperature: 35–37°C
• Southwesterly winds: 10–25 kilometres per hour

North

• Thunderstorms across 40% of the region
• Heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Lampang, Phrae and Tak
• Minimum temperature: 22–28°C
• Maximum temperature: 32–36°C
• Southwesterly winds: 10–20 kilometres per hour

Northeast

• Thunderstorms across 60% of the region
• Heavy rain in Nong Khai, Udon Thani, Sakon Nakhon, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Surin, Si Sa Ket and Ubon Ratchathani
• Very heavy rain in Bueng Kan and Nakhon Phanom
• Minimum temperature: 24–26°C
• Maximum temperature: 33–36°C
• Southwesterly winds: 10–20 kilometres per hour

Central region

• Thunderstorms across 40% of the region
• Rain mainly in Kanchanaburi and Saraburi
• Minimum temperature: 24–27°C
• Maximum temperature: 35–37°C
• Southwesterly winds: 10–25 kilometres per hour

East

• Thunderstorms across 60% of the region
• Heavy rain in Nakhon Nayok and Chanthaburi
• Very heavy rain in Trat
• Minimum temperature: 22–26°C
• Maximum temperature: 31–35°C
• Southwesterly winds: 20–35 kilometres per hour
• Waves about two metres high and above two metres during thunderstorms

South — east coast

• Thunderstorms across 30% of the region
• Rain mainly in Prachuap Khiri Khan, Chumphon, Nakhon Si Thammarat, Yala and Narathiwat
• Minimum temperature: 23–26°C
• Maximum temperature: 33–36°C
• Southwesterly winds: 15–35 kilometres per hour
• Waves one to two metres high and about two metres offshore
• Waves above two metres during thunderstorms

South — west coast

• Thunderstorms across 40% of the region
• Rain mainly in Ranong, Phang Nga, Trang and Satun
• Minimum temperature: 23–26°C
• Maximum temperature: 31–34°C

From Ranong northwards:

• Southwesterly winds: 20–35 kilometres per hour
• Waves about two metres high
• Waves above two metres during thunderstorms

From Phang Nga southwards:

• Southwesterly winds: 15–35 kilometres per hour
• Waves one to two metres high
• Waves above two metres during thunderstorms

Mariners advised to avoid thunderstorms

Moderate wind and wave conditions are forecast in the Andaman Sea and the Gulf of Thailand.

Waves in the upper Andaman Sea and upper Gulf are expected to reach about two metres and rise above two metres during thunderstorms.

The TMD advised vessels to navigate cautiously and avoid areas experiencing thunderstorms.