
Northern Thailand is forecast to face widespread thunderstorms and heavy rain on August 10 as a monsoon trough remains over the upper North and upper Laos, while Bangkok and surrounding provinces are expected to see rain across 60% of the area.
The Thai Meteorological Department (TMD) said heavy rain would persist in some parts of Thailand during the 24 hours from 6am on August 10 to 6am on August 11.
The conditions are being driven by the monsoon trough combined with a relatively strong south-west monsoon prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.
People in affected areas have been advised to watch for heavy to very heavy rain and accumulated rainfall, which could trigger flash floods and run-off, particularly on foothills near waterways and in low-lying areas.
North and Northeast face widespread thunderstorms.
Winds and waves remain relatively strong in the upper Andaman Sea and upper Gulf of Thailand, with waves of 2–3 metres and more than 3 metres during thunderstorms.
Mariners have been advised to navigate with caution and avoid areas affected by thunderstorms. Small boats in the upper Andaman Sea and upper Gulf should remain ashore.
In the East, waves are forecast at 2–3 metres, rising above 3 metres during thunderstorms.
Along the southern east coast, waves will be 1–2 metres, exceeding 2 metres offshore and during thunderstorms.
On the Andaman coast from Phuket northwards, south-westerly winds will reach 20–40km/h, with waves of 2–3 metres and more than 3 metres during thunderstorms.
From Krabi southwards, south-westerly winds will reach 20–35km/h. Waves will be about 2 metres, rising above 2 metres during thunderstorms.