Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–3
Persistent weak layers in the upper snowpack remain a concern for human triggering. Where there is no supportive crust above, triggering these layers remains possible.
New snow and strong southerly winds will build reactive storm slabs on Tuesday.
Storm slabs have the potential to step down and trigger large, destructive avalanches.
Persistent weak layers in the upper snowpack remain a concern for human triggering. Where there is no supportive crust above, triggering these layers remains possible.
New snow and wind have formed reactive storm slabs. Storm slabs will be reactive to human triggering on Tuesday.
On Sunday, operators in the area reported a remotely triggered size 3 avalanche on the early February persistent weak layer on a north east aspect at treeline.
If you head out in the backcountry, let us know what you're seeing by submitting a MIN report.
Up to 50 cm of new snow will have fallen by Tuesday morning. This new snow is falling on surface hoar and facetted snow from recent cold temperatures. In open areas, strong southerly winds will be redistributing new snow, creating wind slabs and wind-affected surfaces. A crust can be found below this snow up to 1500 m.
Two weak layers remain a concern:
A crust/facet layer buried early February down 100 to 130 cm.
A surface hoar layer buried mid-February down 80 to 110 cm.
Recent avalanche activity has involved these layers, with natural and human-triggered avalanches reported.
Below these layers, the remaining snowpack is generally well settled.
Monday Night
Cloudy. 10 to 20 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Tuesday
Cloudy. 2 to 3 cm of snow. 60 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Wednesday
Mostly cloudy. 5 to 10 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Thursday
Mix of sun and clouds. 5 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -7 °C.
More details can be found in the Mountain Weather Forecast.