Large persistent slab avalanches
jeffmoskowitz,
Monday 21st April, 2025 10:00AM
Large natural persistent slab avalanches in the Rainy hollow area on NW-aspects at 1500m with spectacular propagation ~750m. And a deep slab lower on a moraine feature at 1100m. Observed cornice fall and other slab avalanches on Northerly aspects.
Dug a pit at 1600m on a NW-aspect and found a reactive slab down 45cm that propagated on extended column test ECTP21. It failed on faceted snow below a crust layer. Overall poor structure below this interface with punchy layers and strong over weak layering.
At the surface on the northerly was a layer of surface hoar over a firm supportable surface. Big cornices and evidence of recent cornice failure.








Location: 59.58541000 -136.40250000