Scattered thunderstorms, strong winds and some hail and lightning strikes are forecast for upper Thailand from Saturday to Monday, according to the Meteorological Department.
The weather agency on Saturday advised people to be cautious of severe weather conditions in areas affected by summer storms. The public should avoid open areas, stay away from big trees, large billboards and unsecured structures, not wear metal, and refrain from using mobile phones during a storm. Farmers are also advised to prepare and prevent damage to agricultural goods and danger to their livestock.
Hot to very hot weather will prevail across upper Thailand, with strong southerly and southeasterly winds bringing humidity from the Gulf of Thailand and the South China Sea. A high pressure system or cold air mass from China is also expected to prevail over the upper parts of the country on Saturday.
The provinces affected are as follows:
Saturday (April 29)
North: Nan, Uttaradit, Phitsanulok, Phichit and Phetchabun
Northeast: Loei, Nong Bua Lamphu, Udon Thani, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Mukdahan, Chaiyaphum, Khon Kaen, Kalasin, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani
Central Plains: Nakhon Sawan, Lop Buri and Saraburi
East: Nakhon Nayok, Prachin Buri and Sa Kaeo.
Sunday (April 30)
North: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, Tak, Sukhothai, Kamphaeng Phet, Phitsanulok, Phichit and Phetchabun
Northeast: Loei, Chaiyaphum, Khon Kaen, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani
Central Plains: Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Suphan Buri, Lop Buri, Sing Buri, Ang Thong, Ayutthaya, Samut Songkhram, Nakhon Pathom and Greater Bangkok
East: Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat.
Monday (May 1)
North: Mae Hong Son, Chiang Mai, Lamphun, Lampang, Tak, Sukhothai, Kamphaeng Phet and Phitsanulok
Central Plains: Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Ratchaburi, Suphan Buri, Sing Buri, Ang Thong, Samut Songkhram, Nakhon Pathom and Greater Bangkok
Southeast: Phetchaburi and Prachuap Khiri Khan.
More rain is expected in the South due to easterly and southeasterly winds prevailing over the Gulf, the southern region and the Andaman Sea. The department has warned people in the South to brace for heavy rain and flooding.
Waves in the Gulf are expected to be about a metre high and more than 2m high in areas with thundershowers. All ships are warned to proceed with caution, while small boats should remain ashore during this period.