Avalanche Forecast
Issued: Feb 26th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
zryan,
Avalanche Canada
Don't let good visibility and the desire to ride deep powder lure you into consequential terrain. Natural activity may taper but human-triggered storm slabs remain LIKELY! Sheltered and shaded terrain will offer the best and safest riding.
Treat the avalanche danger as HIGH and avoid avalanche terrain and overhead exposure during periods of strong solar radiation.
Summary
Confidence
Moderate
Avalanche Summary
As northerly outflow winds picked up on Wednesday, several natural and human-triggered wind slabs (size 1) were reported throughout the region. These slabs occurred on a variety of aspects in the alpine all the way down to below treeline terrain.
At this time of publishing on Sunday, no new avalanches have been reported.
Looking forward to Monday, storm slabs are expected to remain reactive to human triggering, particularly in wind-loaded areas or on sun-exposure slopes. Be alert to changing conditions with elevation, aspect and exposure to the sun.
Please continue to post your reports and photos to the Mountain Information Network.
Snowpack Summary
Last weekend's storm brought 15-30 cm of new snow down to valley bottom. This new snow is expected to bond poorly to the stiff wind slabs and near-surface facetting formed by recent wind and cold temperatures.
A melt-freeze crust formed in mid-January is buried up to 90-140 cm deep. In some areas, small faceted crystals can be found above the crust. This layer has been reactive during the storm Tuesday night and Wednesday this week. The snow below this layer is well consolidated.
Snowpack depths are just below seasonal averages. Total amounts range from 150 to 300 cm at treeline, but decreases significantly below 1500 m.
Weather Summary
Sunday night
Clear periods with isolated flurries. Alpine temperatures drop to a low of -10 °C. Ridge wind 20 to 50 km/h from the southwest. Freezing level at valley bottom.
Monday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -2 °C. Ridge wind o15 to 35 km/h from the southwest. Freezing level 600 metres.
Tuesday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -4 °C. Ridge wind light from the southwest. Freezing level 500 metres.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Give the new snow several days to settle and stabilize before pushing into bigger terrain.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
- Be alert to conditions that change with elevation and sun exposure.
- Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
- Brief periods of sun could quickly initiate natural avalanche activity.
Problems
Storm Slabs
Up to 30 cm of new storm snow has bonded poorly to the underlying surface and may have formed a widespread storm slab problem. Strong southwest winds have formed deeper more reactive deposits in wind-loaded areas.
Keep in mind that even brief periods of sun could cause rapid settlement in the storm snow and initial natural avalanches. Avoid being on or under sun-exposed slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A crust formed in mid-January can be found down 80 to 120 cm. In areas around the Coquihalla, facets can be found sitting on the crust. This layer is of greatest concern with large triggers, such as a cornice fall, or by first triggering a smaller avalanche that could step down to this interface.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 27th, 2023 4:00PM
