El Nino Watch
Forecast heavy rain and TMD heavy-rain bulletins for the South.
Koh Samui watch
Maximum daily rain forecast for Samui (today + 2 days) and any TMD heavy-rain bulletin in force for the South / Gulf.
Limits. Rain forecasts are uncertain at this scale; a TMD bulletin covers a large area, not only Samui.
A TMD bulletin or 90 mm or more in a day: caution (flooded roads to the piers and on the mainland). 150 mm or more: blocked.
Leaving by ferry means driving to the pier and on through Surat Thani, where roads and the railway can flood in the monsoon.