Heavy rain over small, steep catchments west of Athens produced very rapid runoff into built-up areas. The event is a clear example of a local flash flood with a disproportionately large impact.
Event timeline
- 15 Nov — A violent flash flood affects Mandra and neighbouring areas.
- 16–17 Nov — Intermittent rain and runoff continue, complicating access.
- After the event — Copernicus EMS produces damage-grading maps for assessment.
What happened in the atmosphere
In small, steep catchments the time between intense rain and a sudden rise in water can be very short. Narrow urban outlets and transported debris can worsen the flow.
A global rainfall forecast may not capture these local responses sufficiently. Radar, local gauges, terrain data and operational monitoring by authorities are needed.
What helps us interpret the event
- Hourly rainfall intensity is critical in small catchments.
- Topography and urban development influence the actual path of water.
- Post-event satellite maps support assessment, not immediate warning.
Historical analysis must not be used as guidance for a new event. During active severe weather, follow HNMS, Civil Protection, 112 and local authorities.