BANGKOK, THAILAND – The Meteorological Department has issued a stark warning that torrential rains and flash floods will sweep across large parts of Thailand from October 14 to 19, with key reservoirs in the Chao Phraya basin already at critical levels.
Monsoon surge brings torrential rain
A strong eastward wind band is strengthening the monsoon across the country, the TMD says. Between October 14 and 16, heavy downpours are expected in the lower northeast, the east, the upper Gulf of Thailand, the central region and the lower north. From October 17 to 19, rainfall is forecast to intensify in the central region, Bangkok, the east and the upper south as a monsoon trough aligns over the lower central region and east while a low-pressure cell develops over the upper Gulf.
Dams reach critical levels in Chao Phraya basin
The Royal Irrigation Department reports an alarming situation: the four main reservoirs in the Chao Phraya basin—Bhumibol, Sirikit, Kaew Noi Bamrung Dan and Pa Sak Jolasid—are at roughly 94% of capacity. Collectively they hold about 23.293 billion cubic metres of water and can accept only around 1.583 billion cubic metres more. Nationwide, 483 large and medium reservoirs are 87% full, with capacity for just another 10.253 billion cubic metres.
Rough seas and maritime warnings
Mariners are advised to prepare for hazardous conditions: average wave heights of about one metre are expected in the Andaman Sea and the Gulf of Thailand, rising above two metres in thunderstorms. The TMD explicitly warns small boats to avoid sailing in storm-affected areas between October 14 and 19; conditions will be dangerous for fisheries and tourist excursions.
Flood risk in Bangkok and surrounding areas
Residents in the lower northeast, central and eastern regions and parts of the south are at high risk of flash floods. Bangkok and its suburbs are particularly vulnerable, with drainage systems likely unable to cope with the anticipated volumes. Authorities urge people to avoid low-lying areas and not to drive through flooded streets.
What to expect in the coming days
The forecast is clear: increased rainfall in the north and upper central region from Tuesday to Thursday, followed by heavier downpours in the central region, Bangkok, the east and the upper south from Friday through Sunday. Emergency services and government agencies are on high alert.
How to prepare
Officials recommend residents monitor weather updates, secure property where possible, move valuables to higher ground, and follow evacuation orders if issued. Boaters and tour operators should suspend outings in affected waters. Public authorities will provide further guidance as the situation develops.
Thailand faces a critical weather week; authorities and communities will be tested as heavy rains approach.