Avalanche Forecast
Regions: Glacier.
With new snow and strong winds forecasted to refresh the storm slab problem, the hazard remains elevated.
Careful snowpack evaluation, cautious route-finding and conservative decision making is essential until the new storm snow settles.
Confidence
Moderate
Avalanche Summary
On Saturday, a skier triggered a sz 2 storm slab in the start zone of Frequent Flyer, running full path.
Thursday's storm triggered a few natural avalanches in the hwy corridor, up to size 2.5. Avalanche control Thursday produced widespread results, triggering avalanches up to size 3.0.
Before Thursdays snowfall, large avalanche debris and fracture lines could be seen in most avalanche paths from last weekends storm which produced up to size 4 avalanches.
Snowpack Summary
Up to 20cm of new snow fell Thursday, with strong SW winds. This covers up to 80cm that fell last weekend, accompanied by periods of extreme SW winds. This slab is settling and sits on old breakable crust &/or surface hoar (3-10mm, largest in the alpine).
Two persistent weak layers (PWL) in the heavily facetted snow from cold temps in Jan/Feb are now buried well over a meter. Large triggers such as storm slab avalanches in motion may step-down to these layer.
Weather Summary
Widespread flurries through the weekend with mixed sun & cloud and cool temps into Mon/Tues.
Tonight 5cm. Alpine high -8°C. SW wind 25-45km/hr. FZL 900m.
Sun Trace precip. Alpine high -7°C. West wind 15-30km/hr. FZL 1300m.
Mon 4cm. Low -12°C, High -9 °C. West wind 25-35km/hr. FZL 1200m.
Tues Mix of Sun/Cloud, isolated flurries. Low -14°C, High -11 °C. West wind 20km/hr. FZL 800m.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Avalanche Problems
Storm Slabs
Recent new snow along with strong SW winds, has created a widespread storm slab that is reactive on all aspects and elevations. Natural avalanches are possible and human-triggered avalanches are likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2.5
Persistent Slabs
There are buried persistent weak layer (PWL) 's down more than 60cm in the snowpack. Depending on aspect and elevation, there may be suncrust, facets and/or surface hoar lurking in the mid-upper snowpack. There's potential for step-down avalanches if storm slabs in motion trigger these layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2.5 - 4