Isolated downpours persist in northern and west-central Thailand
Although rainfall is easing across Thailand, accumulated rainfall may cause flash floods, while waves in the upper Andaman Sea exceed 3 metres in areas with thunderstorms.
- Isolated heavy to very heavy rain is persisting in northern and west-central Thailand, even as overall rainfall begins to ease across the country.
- The public in affected areas is warned of potential flash floods and runoff, especially on foothill slopes and in low-lying areas.
- The weather is caused by a monsoon trough shifting north and a weakening southwest monsoon, which is also creating strong winds and high waves in the Andaman Sea and Gulf of Thailand.
- Mariners are advised to navigate with caution, and small boats in the upper Andaman Sea are instructed to remain ashore due to waves reaching 2-3 meters or higher during thunderstorms.
The Thai Meteorological Department (TMD) issued an advisory at 5pm on August 21, warning of heavy to very heavy rain in upper Thailand, with weather impacts continuing until the end of the day.
Rainfall is beginning to ease across Thailand, but isolated heavy to very heavy rain persists in the North and western areas of the Central region.
The monsoon trough has shifted northwards to lie across the upper North and upper Laos, extending into a tropical depression over Hainan Island, China.
Meanwhile, the rather strong southwest monsoon over the Andaman Sea, Thailand and the Gulf of Thailand is beginning to weaken.
People in affected areas should remain alert to the dangers of heavy to very heavy rain and accumulated rainfall, which could cause flash floods and rapid run-off from forested areas, particularly on foothill slopes near waterways and in low-lying areas.
They should avoid travelling on routes prone to recurrent flooding, especially through low-lying areas where temporary inundation may occur.
Wind and waves in the upper Andaman Sea are rather strong.
Waves are 2–3 metres high and exceed 3 metres in areas with thunderstorms.
In the upper Gulf of Thailand, waves are about 2 metres high and exceed 2 metres in areas with thunderstorms.
Mariners in the Andaman Sea and the Gulf of Thailand should navigate with caution and avoid sailing in areas with thunderstorms.
Small boats in the upper Andaman Sea should remain ashore during this period.
An active low-pressure area over Hainan Island, China, has intensified into a tropical depression and is forecast to make landfall in the southern part of Guangdong province, China, on August 23 or 24.
The storm will not enter Thailand and will therefore have no direct impact on the country’s weather.
Travellers to the area should check weather conditions before setting out during that period.
For safety and to minimise potential impacts, the public should carefully plan daily activities and travel during this period and follow announcements from the Thai Meteorological Department.
Updates are available 24 hours a day at http://www.tmd.go.th or by calling 0-2399-4012-13 or 1182.
