Monsoon trough brings heavier rain to Bangkok and upper Thailand

Thailand is bracing for heavier rain over the next 24 hours as the monsoon trough moves down across Myanmar towards a low-pressure cell over upper Laos, while the moderate southwest monsoon continues to cover the Andaman Sea, Thailand and the Gulf of Thailand.

The Thai Meteorological Department said upper Thailand would see more rain, with isolated heavy downpours expected in several areas.

People in affected provinces have been advised to prepare for heavy and accumulated rainfall, which could trigger flash floods and forest run-off, particularly in foothill areas near waterways and low-lying communities.

Bangkok and surrounding provinces are forecast to see thunderstorms across 60% of the area, with heavy rain in some places.

Temperatures are expected to range from lows of 27-28 degrees Celsius to highs of 35-37 degrees Celsius. Southwesterly winds are forecast at 10-25 kilometres per hour.

The upper Andaman Sea is expected to see moderate waves of about 2 metres, while waves in the lower Andaman Sea and the Gulf of Thailand are forecast at 1-2 metres. In areas hit by thunderstorms, waves may rise above 2 metres. The department advised vessels in the Andaman Sea and the Gulf to proceed with caution and avoid sailing through stormy areas.

North faces heavy rain in several provinces

The North is forecast to see thunderstorms across 70% of the region, with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, Phitsanulok, Phetchabun and Tak.

Temperatures are expected to range from 22-27 degrees Celsius to highs of 33-36 degrees Celsius. Southwesterly winds are forecast at 10-20 kilometres per hour.

Upper Northeast warned of widespread thunderstorms

The Northeast is also forecast to see thunderstorms across 70% of the region, with isolated heavy rain in Loei, Nong Bua Lamphu, Nong Khai, Bueng Kan, Udon Thani, Sakon Nakhon, Nakhon Phanom, Khon Kaen, Kalasin, Mukdahan, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Ubon Ratchathani and Nakhon Ratchasima.

Minimum temperatures are expected at 23-27 degrees Celsius, while maximum temperatures are forecast at 33-36 degrees Celsius. Southwesterly winds are expected at 10-20 kilometres per hour.

Central region set for more rain

The Central region is forecast to see thunderstorms across 60% of the area, with isolated heavy rain in Nakhon Sawan, Uthai Thani, Lop Buri, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom and Samut Sakhon.

Temperatures are expected to range from lows of 25-27 degrees Celsius to highs of 34-37 degrees Celsius. Southwesterly winds are forecast at 10-20 kilometres per hour.

Eastern provinces told to watch rough seas

The East is forecast to see thunderstorms across 60% of the region, with isolated heavy rain in Nakhon Nayok, Prachin Buri, Sa Kaeo, Chanthaburi and Trat.

Temperatures are expected to range from 24-27 degrees Celsius to highs of 32-36 degrees Celsius. Southwesterly winds are forecast at 15-35 kilometres per hour. Waves are expected to reach 1-2 metres and rise above 2 metres during thunderstorms.

South sees rain on both coasts

On the South’s east coast, thunderstorms are forecast across 40% of the area, mostly in Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat and Phatthalung.

Temperatures are expected to range from lows of 24-27 degrees Celsius to highs of 33-35 degrees Celsius. Southwesterly winds are forecast at 15-35 kilometres per hour. Waves are expected to reach about 1 metre, rising to 1-2 metres offshore and above 2 metres during thunderstorms.

On the South’s west coast, thunderstorms are forecast across 70% of the area, with isolated heavy rain in Ranong, Phang Nga, Phuket, Trang and Satun.

Temperatures are expected to range from 23-27 degrees Celsius to highs of 31-35 degrees Celsius.

From Phang Nga northwards, southwesterly winds are forecast at 20-35 kilometres per hour, with waves around 2 metres high and above 2 metres during thunderstorms.

From Phuket southwards, southwesterly winds are expected at 15-35 kilometres per hour, with waves of 1-2 metres and above 2 metres during thunderstorms.

The department urged people in risk areas to remain alert to changing weather conditions, while sailors should avoid areas affected by thunderstorms until conditions improve.