Isolated thundershowers forecast for Bangkok and most parts of the country
The southwest monsoon across the Andaman Sea, the South and the Gulf of Thailand is strengthening, bringing isolated heavy rains to the South.
People should beware of the severe conditions, the Thailand Meteorological Department said on Sunday.
Strong winds in the Andaman Sea from Phang Nga northwards trigger waves 2-3 metres high and above 3 metres high in thundershowers.
In the Andaman Sea from Phuket southwards, waves 1-2 metres high and above two metres are likely during thundershowers.
Strong winds are likely in the upper Gulf of Thailand with waves about two metres high and above two metres in thundershowers.
From the lower Gulf, the waves are likely to rise 1-2 metres high and above two metres in thundershowers.
"All ships in the Andaman Sea and the Gulf should proceed with caution. Small boats in the upper Andaman Sea should stay ashore," the department said.
Meanwhile, the active low cell over the upper Bay of Bengal is expected to develop into a tropical cyclone from May 23 to 29. It will force a stronger southwest monsoon across the Andaman Sea, Thailand and the Gulf.
The weather forecast for 24 hours:
Bangkok and its vicinity: Cloudy with isolated thundershowers; minimum temperature 26-27 degrees Celsius, maximum 33-37°C; southwesterly winds 10-25 km/hr.
North: A hot day with isolated thundershowers and gusty winds, mostly in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Kamphaeng Phet, Phichit, Lamphun, Phetchabun and Tak provinces; minimum temperature 22-27°C, maximum 36-39°C; southwesterly winds 10-25 km/hr.
Northeast: A hot day with isolated thundershowers and gusty winds, mostly in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Nakhon Phanom, Sakon Nakhon, Chaiyaphum, Surin, Si Sa Ket, Ubon Ratchathani, Amnat Charoen and Mukdahan provinces; minimum temperature 24-27°C, maximum 36-37°C; southwesterly winds 10-20 km/hr.
Central: A hot day with isolated thundershowers and gusty winds mostly in Ratchaburi, Suphanburi, Kanchanaburi, Uthai Thani, Nakhon Sawan, Saraburi, Ayutthaya, Nakhon Pathom, Samut Songkhram and Samut Sakhon provinces; minimum temperature 25-26°C, maximum 35-39°C; southwesterly winds 10-25 km/hr.
East: Cloudy with scattered thundershowers mostly in Nakhon Nayok, Prachinburi, Rayong, Chanthaburi and Trat provinces; minimum temperature 26-28°C, maximum 32-36°C; southwesterly winds 20-35 km/hr; waves about two metres high and above two metres during thundershowers.
South (east coast): Cloudy with scattered thundershowers and heavy rains in Prachuap Khiri Khan, Chumphon, Surat Thani and Nakhon Si Thammarat provinces; minimum temperature 22-24°C, maximum 34-36°C; southwesterly winds 15-35 km/hr; waves 1-2 metres high and above two metres in thundershowers.
South (west coast): Very cloudy with fairly widespread thundershowers and isolated heavy rains in Ranong, Phang Nga, Phuket and Krabi provinces; minimum temperature 23-26°C, maximum 29-33°C; southwesterly winds 15-35 km/hr; waves 1-2 metres high and above two metres in thundershowers.