El Nino Watch
The island level is only given when every critical factor has current data.
Koh Samui watch
Six factors are critical: El Nino, water/rain, heat, heavy rain/flood, cyclone/wind and sea state. `coverage` lists how many factors have data, which are missing, which are stale, and which critical ones are missing.
Limits. Coverage says whether data arrived, not whether the data is right. Model forecasts can still be wrong even when fresh.
If one critical factor has no data or only old data, the overall level shows 'Unknown' instead of a number, and the headline names what is missing. 'Unknown' is not 'Normal': it means the app cannot tell. The phrase 'No immediate threat on Samui' only appears when all critical data is present and fresh.
A wrong 'Normal' could make you skip preparing or miss the moment to leave. When a source is down, it is safer to say so plainly and point you to the TMD and ferry operators directly.