Avalanche Forecast
Issued: Apr 19th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Persistent Slabs and Deep Persistent Slabs.
isnowsell,
Avalanche Canada
Riders must manage various avalanche concerns that vary by elevation and aspect. Observe your local conditions and let that inform your terrain choices.
Summary
Confidence
Moderate
Avalanche Summary
A number of persistent slab avalanches were reported on Tuesday, up to size 2. They were a combination of explosive and skier triggered, and all appear to have failed on a recently buried (April 1) surface hoar/crust combination. All reported avalanches occurred in the western Purcells.
In the Selkirks the avalanche activity appears to be slowing. However, many natural and human-triggered avalanches were reported last week. Many of these are sliding on recently buried melt-freeze crusts, including a fatal avalanche in the western Purcells and a close call near Revelstoke.
Snowpack Summary
Dry, powder snow remains at higher elevations on north-facing terrain. While multiple melt-freeze crusts or moist snow are likely to be found on steep solar slopes and at lower elevations.
A layer of surface hoar persists down roughly 50 to 100 cm from the surface and appears to be variable in its distribution. The surface hoar may be sitting on top of a thin melt-freeze crust on all but true north-facing slopes. Despite a decrease in avalanche activity on this layer, avalanche professionals continue to closely monitor it.
The mid-snowpack is strong. However, the November depth hoar remains at the base of the snowpack and remains a concern in rocky, shallow, variable depth snowpack areas at treeline and above.
Weather Summary
Wednesday night
Cloudy with clear periods. Light west ridgetop winds. Treeline temperature 0 to -5 C.
Thursday
Cloudy with sunny periods. Light south ridgetop winds. Treeline temperatures 0 to -5 C. Freezing level 1800 m.
Friday
Mix of sun and cloud. Light south ridgetop winds. Treeline temperatures 0 to -5 C. Freezing level 1700 m.
Saturday
Mostly cloudy with scattered flurries. Light south ridgetop winds. Treeline temperatures 0 to -5 C. Freezing level 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Closely monitor how the new snow is bonding to the crust.
- Be alert to conditions that change with elevation and sun exposure.
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
Problems
Storm Slabs
Scattered flurries continue to build storm slabs and may need time to bond to underlying surfaces. Be especially cautious at higher elevations, near ridges and mountain tops were wind has likely increased slab depth and reactivity.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A layer buried on April 1, down roughly 50 to 100 cm from the surface, appears to be most reactive on solar tilted slopes where surface hoar may sit on a hard melt-freeze crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth.
Suspect terrain includes steep, shallow, and rocky terrain where the snowpack varies between thin and thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 20th, 2023 4:00PM
