Thailand warned of widespread heavy rain through September 27

The Thai Meteorological Department (TMD) issued its ninth warning at 5pm on Friday (September 25), forecasting heavy to very heavy rain across much of Thailand through September 27 and warning of possible flash floods and forest run-off.

From September 25 to 27, heavy rain is expected in many areas of the North, Northeast, Central region, Bangkok and surrounding provinces, the East and the South, with very heavy rain possible in some locations.

The conditions are being driven by a strong low-pressure area over the East that is expected to move across the Central region, including Bangkok and surrounding provinces, along a monsoon trough extending across upper Thailand.

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

The TMD warned that people across Thailand should beware of heavy to very heavy rain and persistent rainfall accumulation, which could cause flash floods and forest run-off, particularly on foothill slopes near waterways and in low-lying areas.

“People should avoid travelling on routes that are repeatedly affected by flooding, particularly in low-lying areas where short-term flooding may occur,” it added.

Rough seas expected in Gulf and Andaman Sea

Strong winds and waves are also forecast over the Andaman Sea and the Gulf of Thailand.

Waves in the upper Gulf of Thailand and upper Andaman Sea are expected to reach 2-3 metres, rising above 3 metres during thunderstorms.

In the lower Gulf and lower Andaman Sea, waves are forecast at around 2 metres and could exceed 2 metres in thundery conditions.

Mariners in both the Gulf of Thailand and the Andaman Sea are advised to navigate with caution and avoid areas affected by thunderstorms. Small boats in the upper Gulf of Thailand and upper Andaman Sea should remain ashore through September 27.

The department also urged the public to plan daily activities and travel carefully during the period and continue monitoring official weather warnings. Updates are available through the TMD website and its 24-hour hotlines at 0-2399-4012-13 and 1182.

Forecast from 6pm September 25 to 6pm September 26

• North: Thunderstorms are forecast across 60% of the region. Heavy rain is expected in Mae Hong Son, Chiang Mai, Lamphun, Lampang, Uttaradit, Sukhothai, Kamphaeng Phet, Phichit, Tak and Phitsanulok, with very heavy rain possible in Phetchabun. Minimum temperatures will range from 22-26°C, with highs of 32-35°C.
   
• Northeast: Thunderstorms are expected across 70% of the region. Heavy rain is forecast in Loei, Nong Bua Lamphu, Khon Kaen, Kalasin, Maha Sarakham, Roi Et, Surin and Si Sa Ket, with very heavy rain possible in Chaiyaphum, Nakhon Ratchasima and Buri Ram. Minimum temperatures will range from 22-25°C, with highs of 27-33°C.
   
• Central region: Thunderstorms are forecast across 80% of the region. Heavy rain is expected in Uthai Thani, Sing Buri, Ang Thong, Lop Buri and Saraburi. Very heavy rain is possible in Nakhon Sawan, Chai Nat, Ayutthaya, Suphan Buri, Kanchanaburi, Nakhon Pathom, Ratchaburi, Samut Sakhon and Samut Songkhram. Minimum temperatures will range from 22-25°C, with highs of 29-32°C.
   
• East: Thunderstorms are expected across 80% of the region, with heavy rain in many areas and very heavy rain possible in Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat. Minimum temperatures will range from 22-24°C, with highs of 26-29°C.
   
• South, east coast: Thunderstorms are forecast across 70% of the region. Heavy rain is expected in Prachuap Khiri Khan, Chumphon and Surat Thani, with very heavy rain possible in Phetchaburi. Minimum temperatures will range from 21-25°C, with highs of 29-35°C.
   
• South, west coast: Thunderstorms are forecast across 40% of the region, mainly in Ranong, Phang Nga and Phuket. Minimum temperatures will range from 23-26°C, with highs of 30-34°C.
   
• Bangkok and surrounding provinces: Thunderstorms are forecast across 80% of the area, with heavy to very heavy rain possible in some locations. Minimum temperatures will range from 23-24°C, with highs of 29-31°C.