Brolly time: Thailand braces for heavy rain and flash floods

Thailand is set to experience heavy rainfall despite hot daytime temperatures, with 33 provinces expected to face severe weather conditions, including heavy rain. The Meteorological Department (TMD) forecasts increased rain from today, August 10 to 12, especially in four regions.

The TMD issued a 24-hour weather forecast for today, indicating that Thailand’s upper and lower parts will have less rain overall. However, some areas in the upper northeastern and lower southern regions will still experience heavy rainfall. Daytime temperatures are expected to remain high.

This weather pattern is attributed to a weakening southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand, coupled with a low-pressure area over northern Vietnam.

Additionally, a convergence of easterly and southwesterly winds is affecting the lower southern region. Residents in these areas are advised to be cautious of heavy rainfall and potential flash floods and to take care of their health due to the rising heat.

The weather forecast for today predicts rainfall in 38 provinces, with heavy rain in the eastern and southern regions at a probability of 60%. This could lead to sudden flooding and runoff, especially in mountainous areas near waterways and low-lying regions.

In the Andaman Sea, waves in the upper part, from Ranong province northwards, are moderate with heights of one to two meters. Areas with thunderstorms can expect waves over 2 metres high. Mariners are advised to avoid navigating through stormy areas during this period.

Regional updates

The Northern region is expected to have thunderstorms covering 30% of the area, mainly in Mae Hong Son, Chiang Mai, Nan, Tak, Kamphaeng Phet, and Phetchabun provinces. The temperature will range between 24 to 27 degrees Celcius (°C) at night and 34 to 37°C during the day, with southwesterly winds blowing at speeds of 5 to 15 kilometres per hour (km/h).

In the northeastern region, 40% of the area will see thunderstorms, with heavy rain in Nong Khai, Bueng Kan, Sakon Nakhon, and Nakhon Phanom provinces. Temperatures will range from 24 to 27°C at night to 34 to 36°C during the day, with southwesterly winds at 10 to 20 km/h.

The central region will have thunderstorms in 30% of the area, primarily in Nakhon Sawan, Uthai Thani, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon, and Samut Songkhram provinces. Nighttime temperatures will be between 24 to 27°C, rising to 35 to 37°C during the day. Winds will be southwesterly at 10 to 20 km/h.

In the eastern region, thunderstorms are expected in 40% of the area, mainly in Nakhon Nayok, Prachin Buri, Chon Buri, Rayong, Chanthaburi, and Trat provinces. Temperatures will range from 25 to 28°C at night to 32 to 36°C during the day. Winds will be southwesterly at 15 to 30 km/h, with sea waves about 1 metre high and over 1 meter in stormy areas.

The southern region (eastern coast) will have thunderstorms in 40% of the area, with heavy rain in Surat Thani, Nakhon Si Thammarat, Songkhla, Yala, and Narathiwat provinces. Temperatures will be between 24 to 27°C at night and 33 to 36°C during the day. Winds will be southwesterly at 15 to 30 km/h, with sea waves about 1 metre high and over 1 metre in stormy areas.

The southern region (western coast) will see thunderstorms in 60% of the area, with heavy rain in Phang Nga, Krabi, Trang, and Satun provinces. Nighttime temperatures will range from 24 to 26°C, with daytime temperatures between 31 to 34°C. From Ranong province northwards, winds will be southwesterly at 15 to 35 km/h, with sea waves between 1 to 2 metres high and over 2 metres in stormy areas.

High seas

From Phang Nga province southwards, winds will be southwesterly at 15 to 30 km/h, with sea waves about 1 metre high and over 1 metre in stormy areas.

In Bangkok and its vicinity, thunderstorms are expected in 30% of the area, mostly from the afternoon to evening. Temperatures will range from 26 to 28°C at night to 34 to 36°C during the day, with southwesterly winds at 10 to 20 km/h.