Isolated heavy rains forecast for most parts of the country

A strong southwest monsoon prevails across the Andaman Sea, Thailand, and the Gulf of Thailand.

Isolated heavy to very heavy rains are possible in the Northeast, the East and the west coast of the South. People in these areas should beware of the heavy rains and the accumulated rainfall, the department said.

Strong winds are likely in the Andaman Sea and the upper Gulf of Thailand, with waves 2-3 metres high in the Andaman Sea and above three metres high during thundershowers, and about two metres high during thundershowers in the upper gulf. All ships should proceed with caution during thundershowers and small boats in the upper Andaman Sea should keep ashore, the department said.

Tropical storm “Koguma” over the Tonkin Bay in Vietnam is expected to make landfall over upper Vietnam on Sunday morning, triggering the monsoon trough over the upper North and upper Laos with isolated heavy to very heavy rains in the North and the Northeast.

The weather forecast for the next 24 hours:

North: Fairly widespread thundershowers with isolated heavy rains in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Phrae, Uttaradit, Phitsanulok and Phetchabun provinces; minimum temperature 23-26 degrees Celsius, maximum 29-33°C; southwesterly winds 10-25 km/hr.

Northeast: Fairly widespread thundershowers with isolated heavy to very heavy rains in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Khon Kaen, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Si Sa Ket and Ubon Ratchathani provinces; minimum temperature 23-25°C, maximum 28-32°C; southwesterly winds 10-25 km/hr.

Central: Scattered thundershowers mostly in Nakhon Sawan, Uthai Thani, Lopburi, Saraburi, Suphanburi, Kanchanaburi and Ratchaburi provinces; minimum temperature 23-26°C, maximum 33-35°C; southwesterly winds 10-25 km/hr.

East: Scattered thundershowers with isolated heavy rains in Chonburi, Rayong, Chanthaburi and Trat provinces; minimum temperature 24-28°C, maximum 28-34°C; southwesterly winds 20-35 km/hr; waves about two metres high and above two metres in thundershowers.

South (east coast): Scattered thundershowers mostly in Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla. Yala, Pattani and Narathiwat provinces; minimum temperature 24-26°C, maximum 33-35°C.

From Chumphon northward: southwesterly winds 15-35 km/hr; waves 1-2 metres high and about two metres offshore.

From Surat Thani southward: Southwesterly winds 15-30 km/hr; waves about a metre high and 1-2 metres offshore.

South (west coast): Scattered thundershowers with isolated heavy rains in Ranong, Phang Nga, Phuket, Krabi, Trang and Satun provinces; minimum temperature 22-26°C; maximum 29-33°C.

From Phuket northward: Southwesterly winds 20-40 km/hr; waves 2-3 metres high and above three metres in thundershowers.

From Krabi southward: Southwesterly winds 20-35 km/hr; waves about two metres high and above two metres in thundershowers.

Bangkok and its vicinity: Scattered rain; minimum temperature 26-28°C, maximum 32-35°C; southwesterly winds 10-25 km/hr.