Heavy rain and thunderstorms are forecast across 55 provinces on Friday, according to the Meteorological Department.
The department reported that the rainy weather was likely due to the influence of a monsoon trough crossing over the North and the upper Northeast into the low-pressure area in Laos and Vietnam. The southwest monsoon prevailing over the Andaman Sea and the Gulf of Thailand was gaining strength.
Thunderstorms and heavy rain were expected in the Northeast, the East, Bangkok and its outskirts.
The weather forecaster warned people in the affected areas to to be prepared for possible flash floods. All vessels should proceed with caution in the Andaman Sea and the Gulf.
Bangkok was expected to experience heavy rainfall in 80% of its area until Saturday.
