The Thai Meteorological Department has predicted heavy rainfall in the North and the Northeast until Friday and warns of run-offs, flash floods and landslides in several provinces.

Sugunyanee Yavinchan, department director-general, said on Wednesday that the weather conditions were possible because a monsoon trough was above the North and the upper Northeast, and the southwestern monsoon was strong over the Andaman Sea, Thailand and the Gulf of Thailand.

Ms Sugunyanee warned of flash floods and run-offs especially in slopes near waterways and low-lying areas. She recommended travellers avoid flood-prone roads during the period.

Prasert Purathanang, director of the Northern Meteorological Center, said flash floods, run-offs and landslides were possible in Chiang Mai, Chiang Rai, Lampang, Nan, Phayao and Phrae.

He said that flash floods and run-offs already started and were critical in Nan where rainwater measured more than 340 millimetres. Flash floods struck communities and farmland in Bo Klue, Mae Charim, Muang, Pua, Tha Wang Pha and Wiang Sa districts of Nan, he said.