This weather pattern is due to a medium-pressure system from China covering the northeastern and eastern parts of Thailand, as well as the South China Sea. Meanwhile, the southwestern monsoon still prevails over the southern region and the Gulf of Thailand.
Wave height in the Andaman Sea and the Gulf of Thailand is expected to reach 1-2 metres, more in thunderstorms. Small vessels are advised to navigate with caution.
Typhoon Koinu, located off the southern coast of China, has weakened into a low-pressure system and is not expected to directly impact Thailand's weather conditions.