Avalanche Forecast
Issued: Dec 28th, 2020 4:50PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
Grant Statham,
The snowpack is stabilizing well after last week's storm. Despite the recent wind effect up high, nice powder snow conditions exist at treeline and below. We continue to track the persistent weak layers and do not fully trust them yet.
Summary
Weather Forecast
A ridge of high pressure over the region will keep skies mostly clear, temperatures cool and winds light on Tuesday - looks like an awesome day! Another system will move over the area on Wednesday afternoon, bringing overcast skies and a few flurries but no significant accumulation is expected.
Snowpack Summary
Small amounts of new snow now bury wind slabs created by recent SW-W winds redistributing the 30-60cm of snow from the past week. The Dec 13 and Dec 7 sun crust/surface hoar/facet layers are down ~ 50cm and ~80 cm respectively. The decomposing Nov crust/facets sits at the bottom of the snowpack. Height of snow at tree line is 120-170cm.
Avalanche Summary
Two new small slab avalanches observed in Paradise Valley, both in the alpine and both size 1 windslabs. Otherwise, a detailed look at a lot of terrain over the last few days shows very little recent activity (last 48-hours), but lots of evidence of avalanches that occurred within the last week and are now buried with small amounts of new snow.
Confidence
Problems
Wind Slabs
Recently formed windslabs are now buried with new snow. Expect to find small, spotty slabs as you enter open areas at Tree Line and to encounter more developed slabs in the Alpine.
- Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
There are a variety of weaker layers down 50-80cm at tree line, the Dec 7 and 13th layers of facets, suncrust, and isolated surface hoar. These layers deserve constant suspicion as they can change quickly from one aspect to another.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This problem appears to be dormant during the current few days, but should remain on everyone's radar. It will reawaken with the next storm or significant weather change.
- Be cautious in shallow snowpack areas where triggering is more likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 29th, 2020 4:00PM
