Avalanche Forecast
Issued: Feb 2nd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs, Persistent Slabs and Wind Slabs.
mconlan,
Avalanche Canada
The snowpack remains weak, requiring diligent terrain travel for a safe day.
Summary
Confidence
Avalanche Summary
A few large (size 2) persistent slab avalanches were triggered by explosives over the past couple days, releasing about 40 cm deep in alpine terrain. Small wind slabs continue to be triggered by riders and with explosives, most in the western part of the region.
Looking forward, similar avalanches could be triggered by riders on Friday. The possibility remains of triggering facets near the base of the snowpack, particularly on shallow, rocky slopes.
Snowpack Summary
Wind slabs of approximately 20 cm thick may linger on a variety of surfaces including previously wind-affected snow, a small layer of surface hoar, and a melt-freeze crust on sun-exposed slopes.
The mid-pack contains two layers that remain a concern. The first is buried about 20 to 40 cm and consists of a layer of surface hoar from early January. The second is a layer of surface hoar, facets, and crust buried about 40 to 60 cm.
A layer from late November is found 70 to 130 cm deep and is part of a generally weak faceted snowpack.
Snowpack depths range between 80 and 180 cm at treeline, with the shallowest depths found in the eastern part of the region.
Weather Summary
Thursday Night
Clear skies with no precipitation, 20 km/h southwest wind, treeline temperatures -5 °C.
Friday
Mix of sun and cloud with trace snowfall late afternoon, 20 km/h southwest wind, treeline temperature -4 °C.
SaturdayCloudy with snowfall, accumulation 2 to 5 cm, 20 km/h southwest wind, treeline temperature -4 °C.
SundayCloudy with intermittent snowfall, accumulation 1 to 3 cm, 10 to 20 km/h west wind, treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Surface hoar distribution is highly variable. Avoid generalizing your observations.
- Approach lee and cross-loaded slopes with caution.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Deep Persistent Slabs
It remans possible that riders could trigger a weak layer of facets near the base of the snowpack. The most likely area to trigger it is in shallow areas with variable snow depths. Avoid thin and rocky start zones and select routes that avoid exposure to large avalanche paths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Several weak layers sit in the upper and middle portions of the snowpack at prime depths for human triggering. Stay disciplined and choose low consequence lines, particularly in steep wind-sheltered terrain where these layers may be most problematic.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slabs may linger in lee terrain features, particularly where they overly surface hoar crystals. If triggered, wind slabs could step down to deeper weak layers.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 3rd, 2023 4:00PM
