BANGKOK, THAILAND – The Thai Meteorological Department warned of summer storms across Upper Thailand with thunderstorms, strong gusts, hail and locally heavy rain, valid under announcement No. 6 until 6 March.
Weather authority keeps warning in place until Friday
The TMD stated on 5 March at 11 a.m. that the current severe weather in northern and northeastern parts of the country was expected to continue until 6 March. Thunderstorm cells were forecast to bring heavy rain, lightning and isolated hail, accompanied by strong, gusty winds.
The agency highlighted that these storms could be intense in some areas. It advised the public to closely follow further official updates during the warning period.
Why conditions turned volatile – air masses from China
According to the department, a high-pressure system or cool air mass from China covered the eastern part of the Northeast and the South China Sea. At the same time, southerly to southeasterly winds were transporting moist air from the Gulf of Thailand and the South China Sea into Upper Thailand.
This moisture combined with persistent heat, which acted as an amplifier for storm development. The overlapping systems increased instability in the atmosphere over the region.
Additional trigger from Myanmar – trough over the North
In parallel with the warm, moist air, a westerly trough from Myanmar was moving towards the upper North. The TMD said this feature further raised the likelihood of thunderstorms.
The authority stressed that the combination of ongoing hot weather and the approaching trough favoured the formation of strong summer storms. These conditions were expected to persist over the short term.
Safety advice – avoid open areas, big trees and billboards
The department urged residents and travellers in affected areas to stay away from open spaces during thunderstorms and not to seek shelter under large trees. It also recommended keeping clear of buildings and particularly unstable advertising billboards, as strong gusts could hurl debris and topple structures.
Farmers were asked to secure fruit trees and take steps to limit damage to crops and livestock. The agency also pointed to possible health impacts from the rapid weather changes and advised people to monitor official updates closely.
Regional breakdown – from Chiang Mai to Ubon Ratchathani
For the North, thunderstorms were expected over around 30 percent of the area, including Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Phayao, Phrae, Nan, Uttaradit, Phichit, Phitsanulok and Phetchabun. In the Northeast, storms were forecast over about 40 percent of the region.
Northeastern provinces listed in the outlook included Loei, Nong Khai, Udon Thani, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Roi Et, Yasothon, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani. The distribution of storms was described as scattered but potentially intense where cells developed.
Bangkok and central region – heat, haze and local storms
In the central region, the weather was reported to be hot and hazy during the day, with thunderstorms expected over about 30 percent of the area. Provinces mentioned included Nakhon Sawan, Sing Buri, Ang Thong, Lopburi, Saraburi and Phra Nakhon Si Ayutthaya.
For Bangkok and its vicinity, the forecast saw storms over roughly 20 percent of the metropolitan area, locally with strong gusty winds. Daytime maximum temperatures were projected between 35 and 37 degrees Celsius.
Dust and haze – poor ventilation in North and Centre
In addition to the storm situation, the TMD reported moderate to relatively high levels of dust and haze in the North, the central region including Bangkok, and the East. The agency cited only weak to moderate ventilation as the cause.
Because of the limited air movement, particles were dispersing poorly, leading to hazy conditions at times. The authority implied that air quality could be affected while these patterns persisted.
South and seas – waves over two metres in thunderstorms
In the South, only isolated thunderstorms were expected on land. At sea, however, conditions in storm zones could deteriorate quickly, with waves in the Gulf of Thailand and the Andaman Sea rising significantly.
The department put average wave heights outside thunderstorms at around 1 metre, increasing to over 2 metres in storm areas. It advised seafarers to steer well clear of thunderstorm cells to reduce the risk from rough seas and sudden squalls.