– Warning No. 9 (255/2026) took effect at 5:00 a.m. on October 11th. The next update is due at 5:00 p.m.
– October 11th covers the lower North, the Central region including Bangkok, the East, and the South. October 12th and 13th narrow to the South.
– The East forecast for Sunday puts thunderstorms over about 70 percent of the region, with heavy rain in Chonburi, Chachoengsao, Rayong, Chanthaburi, Trat, and Nakhon Nayok.
– Gulf and Andaman waves can top 2 metres in thunderstorms. The department warned of flash floods, runoff, and landslides, especially near foothills and in low ground.
Bangkok: The Thai Meteorological Department has issued its ninth warning this morning of the current rain spell, covering heavy to very heavy rain, gusts, hail, and lightning from October 11th to the 13th, including in the Bangkok and Chonburi area.
Warning No. 9 (255/2026), signed by deputy director-general Nattawut Dandee as acting director-general, took effect at 5:00 a.m. on October 11th. It says the weather will stay unsettled, with thunderstorms, gusty winds, hail, and isolated heavy to very heavy rain, plus the risk of lightning strikes. On October 11th the affected areas are the lower North, the Central region including Bangkok and its vicinity, the East, and the South. On October 12th and 13th the warning narrows to the South. The next issue is set for 5:00 p.m. on October 11th.
The department blamed a high-pressure system from China covering upper Thailand, easterly and southeasterly winds over the Northeast, the East, and the Gulf, and the southwest monsoon over the Andaman Sea, with the monsoon trough across the upper South. It told people to watch for accumulated rain that can cause flash floods, overflows, and landslides, especially along waterways near foothills and in low-lying spots, and to stay clear of open ground, large trees, and loose billboards in a storm. Ships in the Andaman and the Gulf should expect waves above 2 metres in thunderstorms and should keep clear of them.
For the East on Sunday, the daily forecast puts thunderstorms over about 70 percent of the area, with gusts and heavy rain in places, naming Nakhon Nayok, Chachoengsao, Chonburi, Rayong, Chanthaburi, and Trat. One overnight reading put the very heavy risk on Rayong, Chanthaburi, and Trat. Lows were given as 23 to 27 degrees and highs as 31 to 34, with an easterly wind at 15 to 30 kilometres an hour. Seas about 1 metre, higher than 2 metres in storms.
Pattaya sits in that eastern band. Mayor Poramese Ngampichet had already ordered a 24-hour watch for flooding and rough seas at a City Hall meeting on October 9th, after the same rain system was first flagged.
Late September rain on the same coast sent the Banglamung canal into more than 250 homes. The city’s drains were then described as able to handle about 60 to 70 millimetres a day before water sits on the road. Warning No. 9 does not say Pattaya will flood. It says the ingredients are there.