Avalanche Forecast
Issued: Feb 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Deep Persistent Slabs and Persistent Slabs.
lbaker,
Avalanche Canada
Continue to choose conservative terrain and watch for signs of instability as winds and solar input promote slab development within the storm snow.
Avoid shallow, rocky snowpack areas where triggering the deep persistent weak layer is still possible.
Summary
Confidence
Moderate
Avalanche Summary
On Tuesday, a few size 1 skier accidentals storm slab avalanches were reported 20-40 cm deep. Numerous natural avalanches were reported primarily on north and east aspects where storm snow and wind created deep pockets of slab. Explosive control produced numerous storm slab results to size 3.5.
On Monday, A skier accidental avalanche was observed in the Sun Peaks backcountry. The avalanche was a size 2 and is suspected to have run on a weak layer of surface hoar from late January. Several natural storm slab and wind slab avalanches were reported, size 1-2.5, on east and north aspects at treeline and alpine.
On Sunday, several natural slab avalanches were observed in the region, size 1-2.5, on all aspects between 1600 m and 2400 m. A size 2 skier accidental storm slab avalanche was reported at upper treeline. The avalanche was 30 cm deep and fractured on an unsupported roll.
Snowpack Summary
Incremental loading has brought storm snow totals through the last week to 40-80 cm. Particularly in the Monashees a thin rain crust may be found 20-30 cm down within the storm snow. Below the recent snow is a crust that extends up to 1800 m in the northern part of the region and up to 2000 m further south. This crust is buried about 40 to 100 cm deep and may host small facets on the crust.
Deeper in the snowpack two layers of surface hoar which formed in early January are 60 to 120 cm deep. These weak layers are still on our radar, although snowpack tests are indicating they may be strengthening.
Large and weak facets from November are near the base of the snowpack, which continue to produce very large avalanches in the region.
Weather Summary
Wednesday Night
Clear skies. Ridge wind southwest 20 km/h gusting 40 km/h. Alpine temperature low of -6 C. Freezing level valley bottom.
Thursday
Sunny with cloudy periods in the afternoon and isolated flurries for the northern Monashees, 1-3 cm accumulation. Southwesterly ridge wind 20-40 km/h increasing to 60 km/h in the evening. Alpine temperature high of -5 °C. Freezing level 1000-1200 m.
Friday
Partly cloudy with isolated flurries, 2-5 cm accumulation. Southwesterly ridge wind 40 km/h easing to 20 km/h in the afternoon. Alpine temperature high of -4 °C. Freezing level 1000-1300 m.
Saturday
Partly cloudy with isolated flurries, 2-3 cm accumulation. Westerley ridge wind 20 km/h increasing to 40 km/h in the afternoon. Alpine temperature high of -5 °C. Freezing level 1000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Problems
Storm Slabs
Make observations and asses conditions continually as you travel into different aspects and elevations. Southwest winds are redistributing storm snow into deep pockets at higher elevations. Slabs will likely be the deepest and most reactive on north and east aspects at treeline and above.
Where direct sun is impacting snow surfaces watch for upper snowpack weakening and becoming more unstable. Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Keep in mind that storm slabs have the potential to step down to deeper weak layers, resulting in large and consequential avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer continues to produce very large avalanches that can travel far. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain, or by triggering a smaller avalanche that could step down to this layer. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure. See more on the potential of triggering deeper weak layers in our latest Forecasters' Blog.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Numerous problematic weak layers exist in the top meter of the snowpack. Recent observations suggest these layers are gaining strength, but we would continue to be cautious around steep openings within and near treeline elevations. These layers have been most prevalent in the southern part of the region.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 9th, 2023 4:00PM
