Storm Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 1.5–2.5
The main avalanche concern for today continues to be the new snow that fell between 12/3-12/6 above 3000'. This snow was deposited on top of previously wind damaged surfaces such as sastrugi, low friction wind board and bare ground. Fair-Good bonding has been observed at this interface and is expected to improve as there were no persistent grains at the surface when snowfall began. Today's weather will bring a slow increase in temperatures and light precipitation that is not expected to elevate the avalanche hazard.
The most recent storm had a very dynamic freezing line that has created multiple density changes within the storm snow as well as a rain crust in the middle of the storm slab that exists in some areas up to 4000' and maybe higher. These density changes have the possibility to act as a failure plane. Areas near ridgetops that have deeper slabs due to wind redistribution during the storm will have more stress on these density changes.
The storm slab that is in place will likely vary not only with elevation, but also place to place. Extended column tests (click links for examples) as well as hasty hand shear tests will be useful tools today to assess the sensitivity of the new snow. Jumping on small incosequential test slopes are also a quick way to gather more information in the area you choose to travel. Watch for red flags such as recent natural avalanche activity, shooting cracks and collapsing. If any of these are present it is wise to avoid steep terrain.
(12/6/2024) Photo: Gareth Brown