Heavy rain and flash floods in 55 provinces of Thailand

The Thailand Meteorological Department (TMD) issued a severe weather warning, predicting heavy rain and potential flash floods across 55 provinces, including Bangkok, where 80% of the area is expected to experience significant rainfall.

Thailand is bracing for continuous monsoon activity, as a monsoon trough stretches across the northern and upper northeastern regions, merging with a low-pressure area over Laos and northern Vietnam.

The southwest monsoon over the Andaman Sea, Thailand, and the Gulf of Thailand is intensifying, leading to increased rainfall and heavy downpours in certain areas.

This weather pattern will result in a significant increase in rainfall across the country, with some regions experiencing particularly heavy rain. Residents in northeastern Thailand, Bangkok and its surrounding areas, as well as the eastern provinces, are advised to remain vigilant for potential dangers from heavy to very heavy rainfall.

The accumulated rain could lead to sudden flash floods and mountain runoff, especially in foothill areas near watercourses and low-lying regions.

In the upper Andaman Sea, moderate wind conditions are expected, with waves reaching heights of 1 to 2 metres. In the lower Andaman Sea and the Gulf of Thailand, waves are expected to be around 1 metre high, with areas experiencing thunderstorms seeing waves exceeding 2 metres. Mariners are advised to exercise caution and avoid sailing in areas with thunderstorms.

Regional updates

In the northern region, there will be thunderstorms covering 60% of the area, with heavy rain expected in some areas, including Mae Hong Son, Chiang Mai, Lampang, Chiang Rai, Phayao, Nan, Phrae, Uttaradit, Tak, Phitsanulok, Phichit, and Phetchabun. The temperatures will range from 23 to 25 degrees Celsius at the lowest and 30 to 35°C at the highest, with southwesterly winds at 10 to 15 kilometres per hour.

The northeastern region will also see thunderstorms in 60% of the area, with very heavy rain expected in some areas, including Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Nakhon Phanom, Sakon Nakhon, Mukdahan, Chaiyaphum, Khon Kaen, and Nakhon Ratchasima. Temperatures will range from 23 to 25°C at the lowest and 32 to 34°C at the highest, with southwesterly winds at 10 to 20 km/h.

The central region in Thailand expects similar weather patterns, thunderstorms will cover 60% of the area, with heavy rain expected in some areas, including Nakhon Sawan, Uthai Thani, Lopburi, Saraburi, Kanchanaburi, Phra Nakhon Si Ayutthaya, Ratchaburi, Nakhon Pathom, Samut Songkhram, and Samut Sakhon. Temperatures will range from 24 to 26°C at the lowest and 33 to 35°C at the highest, with southwesterly winds at 10 to 20 km/h.

The eastern region will experience thunderstorms covering 70% of the area, with very heavy rain expected in some areas, including Nakhon Nayok, Prachinburi, Chachoengsao, Chon Buri, Rayong, Chanthaburi, and Trat. Temperatures will range from 23 to 25°C at the lowest and 28 to 34°C at the highest, with southwesterly winds at 15 to 30 km/h. The sea will have waves about 1 metre high, with areas experiencing thunderstorms seeing waves exceeding 2 metres.

In the southern region (eastern coast), there will be thunderstorms covering 60% of the area, with heavy rain expected in some areas, including Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Pattani, Yala, and Narathiwat. Temperatures will range from 24 to 26°C at the lowest and 32 to 35°C at the highest, with southwesterly winds at 15 to 30 km/h. The sea will have waves about 1 metre high, with areas experiencing thunderstorms seeing waves exceeding 2 metres.

In the southern region (western coast), thunderstorms will cover 70% of the area, with heavy rain expected in some areas, including Ranong, Phang Nga, Phuket, Krabi, Trang, and Satun. Temperatures will range from 24 to 25°C at the lowest and 31 to 34°C at the highest.

Harsh seas

In areas from Ranong upwards, southwesterly winds will blow at 15 to 35 km/h, with waves reaching 1 to 2 metres and exceeding 2 metres in areas with thunderstorms. In areas from Phang Nga downwards, southwesterly winds will blow at 15 to 30 km/h, with waves about 1 metre high and exceeding two metres in areas with thunderstorms.

The capital of Thailand, Bangkok, and its vicinity are set to bear the brunt of the turbulent weather, with thunderstorms covering 80% of the area, alongside heavy to very heavy rain in some places. Temperatures will range from 24 to 25°C at the lowest and 30 to 33°C at the highest, with southwesterly winds at 10 to 20 km/h.