Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–3
Numerous natural avalanches have been observed on these layers over the past week, particularly in shallow facetted areas on the the eastside of highway 93N.
Skies will clear Thursday. The more solar input and warming that occurs, the more the hazard will increase.
Avoid areas with a shallow snowpack.
Numerous natural avalanches have been observed on these layers over the past week, particularly in shallow facetted areas on the the eastside of highway 93N.
10-20cm of low density storm snow sits over solar and melt freeze crust. With increased warming and solar Thursday the likelihood of dry and wet loose avalanches will increase. Expect them to run far if they do.
On Wednesday, a road patrol observed evidence of numerous avalanches up to size 2.5 that occurred this past weekend on westerly aspects in the alpine and at treeline, on the east side highway 93N, most of which were persistent slab avalanches in shallow snowpack areas.
No other avalanches were observed or reported Wednesday.
There's 10-20 cm of settling storm snow sitting on the March 2 crust, which rests on a cohesive slab. Below that are the February 22 and January 30 weak layers, followed by a faceted mid-pack and basal facets at the bottom. The snowpack is variable depending on location, and is structurally weak, even when it seems stable—don’t overthink it. Focus on terrain choice and group management.
Wednesday night: Cloudy with clear periods. Alpine temperature: Low -9 °C. Ridge wind light to 20 km/h.
Thursday: A mix of sun and cloud. Alpine temperature: High -4 °C. Light ridge wind. Freezing level: 1800 metres.
Friday: Cloudy with sunny periods. Alpine temperature: Low -12 °C, High -5 °C. Ridge wind west: 10-20 km/h. Freezing level: 1700 metres.