Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible - Likely
- Size
- 1.5–3
Buried weak layers are most concerning at treeline elevations. Small avalanches may step down to this layer resulting in very large, destructive avalanches.
Continue to choose low angle and supported terrain features.
Watch for strong sunshine, even brief periods can rapidly increase avalanche danger and produce natural avalanches.
Buried weak layers are most concerning at treeline elevations. Small avalanches may step down to this layer resulting in very large, destructive avalanches.
Larger and more reactive slabs sit on north and east facing slopes near ridges. Continue to minimize your exposure to avalanche terrain and watch for signs of instability.
Danger will rise quickly if the sun appears.
Remotely triggered avalanches continue, to size 2, failing on the buried facet layer up to 80 cm deep in recent reports.
A recent natural cycle was observed to size 3 at alpine and treeline elevations, where wind or sun was a possible trigger. We expect human triggering remains likely.
Check out this MIN for an overview of conditions, including a good reminder on treewells. Thanks to all for sharing your observations and learnables!
Storm totals of 40-80 cm are beginning to settle, with wind effect in exposed, high terrain.
Multiple weak layers exist in the mid snowpack. The most concerning layer is found down 40 to 100 cm with a layer of facets (or in isolated areas, preserved surface hoar) above a crust. This layer is likely most concerning at treeline.
This layer continues to show sensitivity to human triggers, and will take time to begin to settle and bond.
Sunday Night
Cloudy with flurries, 5 cm in most terrain, higher in localised areas. 10-20km/hr easterly winds. Freezing levels fall to valley bottom.
Monday
Cloudy with possible sunny periods and isolated flurries. Light and variable winds switch to 20 km/hr westerlies in the afternoon. Treeline temperature -11 °C. Freezing levels at valley bottom.
Tuesday
Mostly clear skies. 20-40 km/hr northwest winds. Treeline temperature -10 °C. Freezing levels at valley bottom.
Wednesday
Mostly clear skies. 10-20 km/hr northwest winds. Treeline temperature -10 °C. Freezing levels at valley bottom.
More details can be found in the Mountain Weather Forecast.