BANGKOK: Bangkok and surrounding provinces face heavy to very heavy downpours on Sept 10, with thunderstorms forecast across 80% of the area, the Thai Meteorological Department (TMD) warned.
Rain will continue across Thailand over the next 24 hours. Isolated very heavy falls are forecast in western parts of the North, the lower Northeast, the Central region, including Bangkok and surrounding provinces, and the East.
The department urged people to watch for flash floods and forest runoff caused by heavy and accumulated rainfall. Areas of particular concern include the Mekong basin, foothills near waterways and low-lying land.
People should avoid travelling along routes prone to repeated flooding, particularly in low-lying areas where water may temporarily accumulate.
A high-pressure system, or cool air mass, has already spread over the upper North and upper Northeast, pushing the monsoon trough southwards across the lower North, upper Central region and Northeast towards a strong low-pressure area over the central South China Sea.
A moderate south-westerly monsoon is also covering the Andaman Sea, the South, the Central region, the East and the Gulf of Thailand.
From Sept 11–13, rain will continue in the lower Northeast, the Central region, including Bangkok and surrounding provinces, the East and the South, with heavy to very heavy falls in some areas. Rainfall will decrease in the North and upper Northeast.
During that period, a high-pressure system from China will extend over the upper North and upper Northeast. This will shift the monsoon trough across the lower Central region, lower Northeast and East towards the strong low-pressure area in the central South China Sea. The south-westerly monsoon over the Andaman Sea, the South and the Gulf will strengthen.
The following forecast covers the period from 6am on September 10 to 6am on Sept 11.
North: Thunderstorms across 70% of the region, with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Lamphun, Lampang, Phrae, Sukhothai, Uttaradit, Phichit, Phitsanulok and Phetchabun. Isolated very heavy rain is forecast in Tak and Kamphaeng Phet. Minimum temperatures of 22–25°C and maximums of 31–36°C. Variable winds at 10–20km/h.
Northeast: Thunderstorms across 70% of the region, with isolated heavy rain in Loei, Chaiyaphum, Khon Kaen, Surin, Si Sa Ket and Ubon Ratchathani. Isolated very heavy rain is forecast in Nakhon Ratchasima and Buri Ram. Minimum temperatures of 22–25°C and maximums of 28–32°C. Variable winds at 10–20km/h.
Central region: Thunderstorms across 80% of the region, with isolated heavy rain in Chai Nat, Lop Buri, Saraburi, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Suphan Buri, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon and Samut Songkhram. Isolated very heavy rain is forecast in Nakhon Sawan and Uthai Thani. Minimum temperatures of 23–26°C and maximums of 30–35°C. South-westerly winds at 10–20km/h.
East: Thunderstorms across 80% of the region, with isolated heavy rain in Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri and Rayong. Isolated very heavy rain is forecast in Nakhon Nayok, Chanthaburi and Trat. Minimum temperatures of 23–27°C and maximums of 29–33°C. South-westerly winds at 15–35km/h. Waves of 1–2 metres, exceeding 2 metres in thunderstorms.
South, east coast: Thunderstorms across 60% of the region, with isolated heavy rain in Phetchaburi, Prachuap Khiri Khan, Chumphon and Surat Thani. Minimum temperatures of 23–26°C and maximums of 33–36°C. South-westerly winds at 15–35km/h. Waves of about 1 metre, rising to 1–2 metres offshore and exceeding 2 metres in thunderstorms.
South, west coast: Thunderstorms across 60% of the region, with isolated heavy rain in Ranong, Phang Nga, Phuket and Krabi. Minimum temperatures of 24–27°C and maximums of 29–33°C.
From Phuket northwards, south-westerly winds at 20–35km/h and waves of about 2 metres, exceeding 2 metres in thunderstorms. From Krabi southwards, south-westerly winds at 15–35km/h and waves of 1–2 metres, exceeding 2 metres in thunderstorms.
Bangkok and surrounding provinces: Thunderstorms across 80% of the area, with isolated heavy to very heavy rain. Minimum temperatures of 24–26°C and maximums of 32–34°C. South-westerly winds at 10–20km/h.
Winds and waves in the Andaman Sea and Gulf of Thailand will be moderate. Waves in the upper Andaman Sea will reach about two metres, exceeding two metres in thunderstorms.
Mariners in both the Andaman Sea and the Gulf should navigate with caution and avoid thunderstorms.
The strong low-pressure area over the central South China Sea is likely to develop into a tropical cyclone during Sept 11–13 and is expected to approach the coast of northern Vietnam during Sept 14–15. The department advised the public to continue monitoring weather forecasts. - The Nation/ANN
