These conditions are brought by the weak high-pressure system over upper Thailand and the South China Sea, as well as the easterly and southeasterly winds that blow moisture across the country.
People should beware of the severe conditions that may cause flash floods and overflows, especially along foothills near waterways and lowlands. All transport should use more caution, the department warned.
For sea conditions, waves in the Andaman Sea and the Gulf could rise to a metre high and over two metres high during thundershowers. All ships should proceed with caution and keep off thundershowers, the department said.
The areas expected to be affected by thundershowers are:
North: Chiang Mai, Chiang Rai, Phayao, Nan, Lampang, Phrae, Tak and Phitsanulok.
Northeast: Loei, Nong Bua Lamphu, Chaiyaphum, Khon Kaen, Nakhon Ratchasima, Buriram, Surin, Sisaket and Ubon Ratchathani.
Central:…
