The Thai Meteorological Department forecasts thunderstorms over 60-80% of the country for the next 24 hours, with heavy rain in central Thailand including Bangkok and its vicinity, and heavy rain in parts of the south. Warnings cover flash floods, flash floods from mountain runoff and landslides. Plan for delivery delays, flooded access roads and stock or equipment at low-lying sites. Small boats in the upper Andaman Sea should stay in port until 20 Sep 2026; waves there are 2-3 m, over 3 m where storms form.