Thailand warns of floods, rough seas from storms this week

BANGKOK — May 14, 2026: Thailand's Meteorological Department (TMD) issued its third weather warning on Thursday, cautioning that heavy to very heavy rainfall could trigger flash floods and forest runoff across parts of the country from May 14-18.

The department stated in Advisory No. 3 (63/2026) that increased rainfall is expected in the northern, central, eastern and southern regions as a strong low-pressure system over the lower Bay of Bengal moves towards the upper Bay of Bengal, while the southwest monsoon strengthens over the Andaman Sea, Thailand and the Gulf of Thailand.

Residents in areas prone to flooding, particularly along foothills, waterways and low-lying areas, were urged to remain alert for possible flash floods and sudden runoff caused by heavy to very heavy rain and accumulated rainfall.

The shift in weather is attributed to a powerful low-pressure cell over the lower Bay of Bengal, which is moving toward the upper reaches of the bay. Simultaneously, the south-western monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand is gaining strength.

Authorities also warned of increasingly rough seas in the Andaman Sea and the Gulf of Thailand. From May 15-18, waves in the Andaman Sea are expected to reach 2-3 meters, with waves exceeding 3 meters in areas affected by thunderstorms. In the upper Gulf of Thailand, waves are forecast at around 2 meters and higher than 2 meters during storms.

The department advised mariners to navigate with caution and avoid areas experiencing thunderstorms. Small boats in the Andaman Sea were urged to remain ashore during the warning period.

Residents can track live updates at http://www.tmd.go.th, the department's website, or its 24-hour emergency hotlines: 0-2399-4012-13 and 1182.

The announcement was issued at 05:00 on Thursday. TMD said its next update would be released at 17:00 on the same day.