Avalanche Forecast
Issued: Feb 5th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
TRettie,
Avalanche Canada
Pay attention to the snow surface, as temperatures rise and the sun comes out sensitivity to triggering avalanches could increase.
Summary
Confidence
Weather Forecast
Saturday night: no new snow expected. Light to moderate west winds with a low of -6 at 1400m.
Sunday: mix of sun and cloud with No new snow expected. Light to moderate west winds in the morning and moderate to strong southwest in the evening. Freezing levels rising to 2000 m.
Monday: stormy weather with up to 10 cm of snow and moderate to strong west winds. Freezing levels around 1400 m.
Tuesday: light flurries bringing trace amounts of snow. Strong west winds and freezing levels around 1300m.
Avalanche Summary
On Friday several skier triggered size one wind slab avalanches were reported. These avalanches were triggered in steep features just below ridge crests at treeline and above.
Over the past few days several skier triggered avalanches to size 2 have been reported. We believe these avalanches have been failing on the same layer, a layer of facets on a crust from late January. Most avalanche activity on this layer is around 1900m but some have been reported in the alpine as well.
On Tuesday, we received report of a large (size 2.5) human-triggered avalanche near Rainbow Mountain that caught and carried a group of five skiers. The avalanche released on a north aspect at 1900 m. It broke 40 cm deep and ran on the late January facet-crust layer. The avalanche propagated across adjacent roll-over features and triggered a sympathetic slide on a small feature 200 m away.
Snowpack Summary
10 to 20 cm of new snow with moderate to strong southwest winds have formed wind slab on north and east aspects in the treeline and alpine. The late January crust is now on the surface on some exposed south facing slopes in the alpine.
Moist snow will likely be observed on south facing slopes and all aspects at treeline and below as the skies clear and freezing levels rise.
A layer of facets on a crust is now buried down 30 to 70 cm. This layer is widespread between 1800 m and 2000 m, but could be found above and below this elevation band. It has produced several human and remote triggered avalanches in the past few days. In sheltered terrain at treeline surface hoar can also be found on this layer.
Terrain and Travel
- Be aware of the potential for large avalanches due to the presence of buried weak layers.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Extra caution is needed around cornices under the current conditions.
- Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
Problems
Persistent Slabs
30 to 70 cm of snow sits over a facet-crust weak layer combination that is possible to human trigger. Recent observations demonstrate the potential for this problem to be triggered remotely and release sympathetic avalanches in adjacent terrain. It is most reactive between 1800 and 2000 m. Avoid avalanche terrain around this elevation band and be aware of slopes above you that could be remotely triggered.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Rider triggerable wind slabs could be found on north and east aspects in the treeline and above.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 6th, 2022 4:00PM
