Swiss Flash Floods and Intense Rainfall

June 21st, 2024. Switzerland. Rainfall led to significant flash flood impacts in the Moesa River valley in Switzerland. Official totals show around 100mm of rain within 1 hour around Grono, with unofficial data showing 15mm in five minutes ending at 19:35 at one site. Landslides resulted in fatalities. Part of the A13 road was undermined by erosion. The discharge at Lumino increased from 214m³/s to 594 m³/s in 30 minutes from 19:45, according to Swiss Govt flood warning data. The catchment area to Lumino is 472km².