What is a GLOF?
A glacial lake outburst flood is a sudden release of water from a glacial lake. Hazard classification of a lake (for example ICIMOD's potentially dangerous glacial lakes) does not mean an outburst is happening now.
Warning level vs danger level
DHM publishes station-specific water-level thresholds. Warning means the river deserves attention. Danger is a higher threshold. Neither is an automatic "evacuate now" unless an authorised agency says so.
Stale data
Every reading carries its age, and the age decides how it is drawn. Silent gauges are not live.
| Age of reading | Shown as | What it means |
|---|---|---|
| 0–15 minutes | Live | A current reading. |
| 15–60 minutes | Recent | Close to current; check the time before acting on it. |
| 1–3 hours | Delayed | The gauge or feed is behind. Conditions may have changed. |
| Older than 3 hours | Stale | Not a current reading. A silent gauge is never shown as live. |