Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–3
The primary layer of concern in much of the region is a layer of surface hoar down 20-50 cm. If triggered, avalanches on this layer could step down to deeper weak layers.
Be mindful of buried weak layers within range of human triggering.
The primary layer of concern in much of the region is a layer of surface hoar down 20-50 cm. If triggered, avalanches on this layer could step down to deeper weak layers.
A layer of weak facets near the ground may be reactive to human triggering, especially in shallow, rocky areas in alpine terrain where the layer is not capped by a crust.
Small loose wet avalanches were reported on south aspects in the warm weather on Saturday.
Prior to the weekend, explosive-triggered wind slabs were reported to size 1.5 in the northwest Purcells and ski cuts produced loose dry to size 1 in the upper snowpack facets near Invermere.
Various snow surfaces exist including crusts, settled powder, unconsolidated facets and old wind slab. Beneath lies a complex snowpack with many layers that vary across the region.
The most prominent is a layer of surface hoar buried 20-50 cm deep. It is less of a concern in areas where a strong, supportive crust exists above the surface hoar layer.
The lower snowpack is typically characterized by sugary, facetted crystals and a crust.
Snowpack depths at treeline average 50-120 cm with significant variability across the region.
Monday night
Partly cloudy, ridgetop wind 15 km/h southeast, treeline temperature -10 °C.
Tuesday
A mix of sun and cloud, ridgetop wind 15 km/h south, treeline temperature -7 °C.
Wednesday
Mostly cloudy, ridgetop wind <10 km/h south, treeline temperature -6 °C.
Thursday
A mix of sun and cloud, ridgetop wind <10 km/h south, treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.