Bangkok: The Meteorological Department has issued a warning for heavy to very heavy rain expected to affect the North and upper Northeast regions of Thailand. The fourth announcement highlights the potential impacts of heavy rainfall, particularly in the provinces of Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Phrae, and the upper Northeast. Residents in these areas are advised to be cautious of flash floods and forest runoff, while the Andaman Sea is also anticipated to experience stronger waves.
According to Thai News Agency, the heavy rain forecast is due to a monsoon trough passing through the upper parts of Myanmar, the North, the upper Northeast, and Vietnam, combined with a low-pressure cell in the upper Northeast region. This weather pattern is expected to strengthen the southwest monsoon over the Andaman Sea, Thailand, and the Gulf of Thailand between July 12-13, 2025.
Residents are urged to be vigilant about the risks associated with heavy to very heavy rain, which may lead to flash floods and forest runoff, particularly in hillside areas near waterways and low-lying regions. It is recommended to avoid traveling through areas prone to thunderstorms and recurring flooding issues, especially in low-lying areas susceptible to short-term flooding.
On July 12, 2025, provinces across various regions, including Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, and others in the Northern region, are expected to experience significant rainfall. Similar conditions are anticipated in parts of the Northeast, Central, Eastern, and Southern regions. The heavy rain is forecasted to continue into July 13, 2025, affecting additional areas including Bangkok and its vicinity.
In terms of maritime conditions, the Andaman Sea is expected to see stronger waves, with heights reaching 2-3 meters in the upper Andaman Sea and even higher during thunderstorms. Sailors are advised to exercise caution and avoid areas with thunderstorms, while small boats in the upper Andaman Sea are recommended to remain ashore during this period.
To ensure safety and mitigate potential impacts, the public is encouraged to carefully plan their activities and travel during this period. Continuous updates and announcements from the Meteorological Department can be accessed through their website or by calling their helplines, which are available 24 hours a day.