Avalanche Forecast
Issued: Jan 29th, 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.
trettie,
Avalanche Canada
This challenging snowpack continues to produce avalanches. Stick to low-angle terrain away from any overhead hazard.
Read more in the latest Forecaster Blog.
Summary
Confidence
Moderate
Avalanche Summary
Both natural and human-triggered persistent and deep persistent slab avalanches continue to be reported daily.
On Saturday skiers remotely triggered a size 2 wind slab sitting over surface hoar from early January. This avalanche occurred on a northeast aspect at treeline. A size 3 natural deep persistent slab avalanche also occurred earlier in the day on a southerly aspect in the alpine. This min discusses more human triggered avalanches in the region.
On Friday east of Prince George, skiers triggered a size 2 deep persistent avalanche on a northeast slope at 1700m, the avalanche was triggered from the shallowest portion of the feature and the crown depth varied from 30 cm to 1 m. Additionally, two very large (size 2.5-3) natural wind slabs were reported on northeast-east and southeast aspects around 1900 m.
On Thursday a few very large (size 2.5-3) natural wind slab avalanches were reported around 1800-2000 m. Additional ongoing evidence of weak basal facets continued with a size 3 deep persistent avalanche reported on a steep southeast slope at 2400 m.
On Monday, a fatal skier-triggered avalanche incident occurred in the Selkirk range near Revelstoke. The avalanche occurred on an east aspect at 1900 m, on a steep, open and unsupported slope. The size 2 avalanche had a crown depth of 50 cm and failed on surface hoar buried in early January.
Snowpack Summary
20-40 cm recent snowfall covered a layer of surface hoar and thin crust on solar aspects at treeline and higher, and a supportive crust up to 1800 m. North and westerly winds have redistributed loose snow to lee terrain.
A prominent layer of buried surface hoar can be found roughly 40-70 cm deep. It is found in some places but not in others, and has been recently reactive to human triggering.
The bottom of the snowpack is made up of large weak facets buried in late November, causing the Deep Persistent Slab problem for this region.
Weather Summary
Sunday Night
Increasing cloud with no new snow expected. Strong north to northwest winds and a low of -25 at 1800m.
Monday
Mostly cloudy with around 5cm of new snow expected. Strong northwest winds and a high of -15 at 1800m, possible temperature inversion with colder temps lower in valleys.
Tuesday
Stormy with 5 to 15cm of new snow expected. Light to moderate west winds with a high of -9 at 1800m.
Wednesday
Stormy with up to 20cm of new snow expected. Moderate west winds and a high of -6 at 1800m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- 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.
Problems
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer has most recently been reactive in upper treeline/lower alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow previously undisturbed terrain or by first triggering a layer further up in the snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A surface hoar layer is found 40-70 cm deep throughout the region and has been reactive in scattered areas around the region. Be especially cautious around steep openings at treeline and below.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Northwest winds have formed wind slabs on south and east aspects and cross loaded others.
Be aware that wind slab avalanches could step down to deeper layers
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 30th, 2023 4:00PM
