Thailand's Meteorology Department issued a heavy rain alert for 37 provinces across the Northeast, East, North, Central, and South regions on July 28, with flash flooding expected in low-lying and foothill areas due to strengthening monsoon
The Meteorology Department's 24-hour forecast issued on July 28, 2569, predicts very heavy rain in parts of the Northeast and East regions, with heavy rainfall also expected in the North, Central, Bangkok metropolitan area, and South. The forecast is driven by a monsoon trough passing through the upper North and northern Laos, combined with a strengthening southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand. Residents are urged to be cautious of heavy to very heavy rainfall and accumulated water, which may trigger flash floods and flash flooding, particularly in foothill areas near waterways and low-lying zones.
The upper Andaman Sea will see moderately strong winds and waves 2-3 meters high, exceeding 3 meters in thunderstorm areas. The lower Andaman and upper Gulf of Thailand will have waves around 2 meters, rising above 2 meters in thunderstorm zones. Mariners are advised to navigate cautiously, avoid thunderstorm areas, and small boats in the upper Andaman should remain ashore during this period.
Regional forecasts for the next 24 hours include:
**North**: 70 percent thunderstorms with heavy rain in some areas. Provinces including Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Tak, Phichit, and Phetchabun. Low 23-27°C, high 30-34°C. Southwest winds 10-20 km/h.
**Northeast**: 70 percent thunderstorms with heavy to very heavy rain in some areas. Provinces include Nong Khai, Bueng Kan, Udon Thani, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Nakhon Ratchasima, Buriram, Sisaket, and Ubon Ratchathani. Low 23-26°C, high 30-34°C. Southwest winds 10-20 km/h.
**Central**: 60 percent thunderstorms with heavy rain in some areas. Provinces include Lopburi, Saraburi, Ayutthaya, and Kanchanaburi. Low 23-27°C, high 33-36°C. Southwest winds 10-25 km/h.
**East**: 70 percent thunderstorms with heavy to very heavy rain in some areas. Provinces include Nakhon Nayok, Prachuap Khiri Khan, Sa Kaeo, Rayong, Chachoengsao, and Trat. Low 24-28°C, high 28-33°C. Southwest winds 20-35 km/h. Sea waves around 2 meters, exceeding 2 meters in thunderstorm areas.
**South (East Coast)**: 40 percent thunderstorms with heavy rain in some areas. Chumphon and Surat Thani provinces. Low 23-26°C, high 33-35°C. Southwest winds 15-35 km/h. Waves around 1 meter nearshore, 1-2 meters offshore, exceeding 2 meters in thunderstorm zones.
**South (West Coast)**: 60 percent thunderstorms with heavy rain in some areas. Ranong, Phang Nga, and Phuket provinces. Low 23-27°C, high 30-34°C. From Phang Nga northward: southwest winds 20-40 km/h, waves 2-3 meters, exceeding 3 meters in thunderstorm areas. From Phuket southward: southwest winds 20-35 km/h, waves around 2 meters.