Heavy monsoon rains to hit 42 Thai provinces including Bangkok

Heavy monsoon rains are expected to lash 42 provinces across Thailand, including Bangkok, with 70% of the area predicted to experience significant rainfall. The Thai Meteorological Department (TMD) issued warnings for flash floods and forest runoffs.

TMD forecasts that monsoon troughs will traverse the upper southern and eastern regions of Thailand, moving into a low-pressure area over southern Vietnam. Concurrently, easterly and southeasterly winds will bring moisture from the South China Sea and the Gulf of Thailand, covering the lower northeastern, central, and eastern regions, including Bangkok and its surrounding areas.

This weather pattern is likely to result in heavy rainfall in several areas of the lower northeastern, central, and eastern regions, as well as Bangkok and its vicinity. Residents are advised to be cautious of flash floods and forest runoffs, particularly in hilly areas near watercourses and low-lying regions.

The Andaman Sea is forecasted to have waves up to 1 metre high, while the Gulf of Thailand will see waves below 1 metre. However, areas experiencing thunderstorms could face waves reaching over 2 metres. Mariners are urged to avoid sailing in stormy regions.

From tomorrow until three days later, another cold air mass from China will extend over the upper northern and upper northeastern regions, as well as the South China Sea. This will bring easterly and southeasterly winds, carrying moisture from the South China Sea and the Gulf of Thailand into upper Thailand.

The monsoon trough will pass through the central southern region, leading to an increase in thunderstorms, heavy rainfall in numerous areas, and strong winds in some locations.

Heavy monsoon

Northern Region: Thunderstorms are expected in 30% of the area, particularly in Tak, Sukhothai, Uttaradit, Kamphaeng Phet, Phitsanulok, and Phetchabun. Temperatures will range from 23 to 25°C minimum to 32 to 34°C maximum, with easterly winds at 10 to 15 kilometres per hour.

Northeastern Region: Thunderstorms will cover 30% of the area, with heavy rain in Nakhon Ratchasima, Buriram, Surin, Sisaket, and Ubon Ratchathani. Temperatures range from 22 to 25°C minimum to 32 to 34°C maximum, with easterly winds at 10 to 20 kilometres per hour.

Central Region: Thunderstorms in 40% of the area, with heavy rain expected in Ratchaburi, Nakhon Pathom, Samut Songkhram, Samut Sakhon, Lopburi, Saraburi, and Ayutthaya. Temperatures will be between 23 and 26°C minimum and 33 and 34°C maximum, with variable winds at 10 to 20 kilometres per hour.

Eastern Region: Thunderstorms will affect 70% of the area, with heavy rain in Nakhon Nayok, Prachinburi, Chachoengsao, Sa Kaeo, Chon Buri, Rayong, Chanthaburi, and Trat. Temperatures range from 24 to 25°C minimum to 30 to 33°C maximum, with variable winds at 10 to 30 kilometres per hour. The sea will have waves below 1 metre, but areas with thunderstorms could see waves over 2 metres.

Southern Region (East Coast): Thunderstorms in 60% of the area, with heavy rain in Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, and Narathiwat. Temperatures will range from 24 to 26°C minimum to 32 to 34°C maximum, with variable winds at 10 to 30 kilometres per hour. The sea will have waves below 1 metre but areas with thunderstorms could see waves over 2 metres.

Southern Region (West Coast): Thunderstorms in 70% of the area, with heavy rain in Ranong, Phang Nga, Phuket, Krabi, and Trang. Temperatures will range from 24 to 25°C minimum to 31 to 33°C maximum, with southwesterly winds at 15 to 30 kilometres per hour. The sea will have waves up to 1 metre, but areas with thunderstorms could see waves over 2 metres, reported KhaoSod.

Bangkok and Surrounding Areas: Thunderstorms will affect 70% of the area, with heavy rain in some locations. Temperatures will range from 25 to 26°C minimum to 32 to 34°C maximum, with variable winds at 10 to 20 kilometres per hour.