Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
Snowpit data is pointing to a developing persistent slab problem in the Northern Elkhorns on north facing terrain that is typically sheltered from the wind. Snowpit data gathered near the base of Lakes Lookout reveal a potentially dangerous crust/facet combination in the upper foot of the snowpack. This structurally weak area of the snowpack is sitting on an ideal sliding surface. I conducted two Extended Column Tests and both columns failed on weak sugar snow (facets) that has formed above our January 6 raincrust. The columns failed using a moderate amount of force. Both column failures exhibited full propagation. I would expect to find similar structural conditions in othe isolated areas in the Northern Elkhorns where we have a well defined raincrust from the January 6 rain event. It is recommended that recreationalists carefully assess or avoid narrow north facing terrain steeper than 35 degrees that is typically sheltered from sunlight and direct wind.
Snowpit near base of Lakes Lookout. Column failed (full propagation) 8" down from the snow surface on facets that have developed above the January 6 raincrust.