Avalanche Forecast
Issued: Mar 26th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Deep Persistent Slabs.
JA,
Avalanche Canada
Variable convective flurries produced 2-10cm of new snow on Sunday. Isolated pockets of deeper snow may be found in the forecast area and will likely not be bonding well to a solar crust from last week.
Large triggers such as cornice falls continue to trigger persistent slabs. Human triggering of the persistent and deep persistent slab remains possible.
Solar warming should once again factor into your trip planning - avoid exposure to southerly slopes during peak warming.
Summary
Confidence
Avalanche Summary
Limited new activity noted on the Icefields Parkway on Sunday - a couple of dry loose size 1.5 in the alpine Mount Cirus; serac activity estimated size 2 off of Stutfield.
Maligne patrol noted a cornice triggered persistent slab size 2.5 east aspect and a size 2 persistent slab west aspect both visible just south of Medicine lake.
Cornice failures and loose wet avalanches may increase late afternoons as sunshine returns Monday and Tuesday.
Don't forget to post avalanche observations to the MIN.
Snowpack Summary
2-10cm of new snow/graupel sits over a breakable sun crust at all elevations on solar aspects. True north aspects are faceted with widespread wind effect in open areas at tree line and above. Approximately 20-50cm down is a persistent slab sitting over a facet layer in sheltered terrain or a weak crust at low elevations / southerly slopes. The lower snowpack is generally weak with large facets and depth hoar at the base.Snow depth varies from 60-150cm.
Weather Summary
Monday will be a mix of sun and cloud as a surface ridge of high pressure becomes established. The freezing level will remain at valley bottom with winds staying light from the north. Tuesday will be similar with the freezing level rising to 1500m. Scattered flurries are expected Wednesday afternoon as a low pressure system descends from the north. Freezing level rising to 1900m - light rain possible at lower elevations.
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Persistent Slabs
There is a cornucopia of weak interfaces throughout the snowpack depending on aspect, elevation, and local terrain influences. There have been a few avalanches this past week which appeared to have stepped down to multiple layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Persistent slab avalanches have stepped down to the deep persistent slab since the last storm meaning large triggers can influence this basal weakness.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 27th, 2023 4:00PM
