Heavy rain and flash flood warnings for southern Thailand

Heavy rain is set to lash the southern regions of Thailand, prompting the Meteorological Department of Thailand (TMD) to issue warnings of flash floods and overflowing mountain streams in ten provinces. Meanwhile, the northern areas will experience a drop in temperatures.

The TMD forecasted weather conditions for the next 24 hours, highlighting that a high-pressure system from China is extending over the upper parts of Thailand. This is expected to bring cooler morning temperatures, with a further dip of one to two degrees Celsius °C in the north. Scattered light rain may occur in some areas of the lower northeastern region.

A south-easterly wind is sweeping across the eastern regions, resulting in thunderstorms along the coastal areas. Meanwhile, a monsoon trough is moving across the central south, accompanied by a low-pressure area along the trough. The north-eastern wind, moderate in strength, is prevailing over the upper Gulf of Thailand and the upper southern region, leading to heavy to very heavy rain in parts of the south.

Wave conditions in the Gulf of Thailand and the Andaman Sea remain moderate. Waves in the upper Gulf could rise between 1 to 2 metres, while those in the lower Gulf and Andaman Sea may reach about 1 metre. In thunderstorms, waves could exceed 2 metres.

For the northern region, morning temperatures are cool with a further decrease of one to 2 degrees Celsius. The temperature is expected to range from 18 to 22°C in the morning and rise to 31 to 34°C during the day. The north-eastern winds are blowing at a speed of 10 to 20 kilometres per hour (km/h).

The northeastern region will also experience cool mornings with light rain in some areas, primarily in the lower parts. Temperatures are expected to range from 18 to 22°C in the morning and 30 to 32°C at its peak. North-eastern winds will prevail at speeds of 10 to 25 km/h.

Dropping temps

Central Thailand will experience cool mornings, with temperatures ranging from 21 to 23°C, reaching highs of 32 to 34°C. North-eastern winds will blow at 10 to 20 km/h.

In the eastern region, expect cool mornings with thunderstorms affecting 10% of the area, particularly in Chanthaburi and Trat. Morning temperatures will range from 22 to 24°C, with highs of 32 to 34°C. The north-eastern winds will have speeds of 15 to 35 km/h, with sea waves reaching around 1 metre and rising to 1 to 2 metres offshore. In stormy areas, waves could exceed 2 metres.

On the south-eastern coast, thunderstorms are expected to cover 70% of the area, with heavy to very heavy rainfall in Prachuap Khiri Khan, Chumphon, Surat Thani, and Nakhon Si Thammarat. Morning temperatures will range from 22 to 25°C, with highs of 31 to 34°C.

From Surat Thani upwards, north-eastern winds will blow at 15 to 35 km/h, with sea waves reaching 1 to 2 metres. From Nakhon Si Thammarat downwards, western winds will blow at 15 to 30 km/h, with sea waves around 1 metre and 1 two metres in stormy conditions.

The southwestern coast will see thunderstorms over 60% of the area, with heavy rain in Ranong, Phang Nga, Phuket, and Krabi. Temperatures will range from 23 to 25°C in the morning, rising to 31 to 33°C. North-western winds will blow at speeds of 15 to 30 km/h, with sea waves around one metre and over two metres in stormy areas.

Bangkok and its vicinity will experience partly cloudy skies, with temperatures ranging from 24 to 26°C in the morning and highs of 32 to 34°C. North-eastern winds will prevail at speeds of 10 to 20 km/h.