Avalanche Forecast
Issued: Mar 15th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Deep Persistent Slabs.
DH,
Avalanche Canada
The strong March sun will the increase the likelihood of triggering slabs on sunny aspects, pay attention to changes in surface snow stability between shaded and sunny slopes.
Summary
Confidence
Moderate
Avalanche Summary
Natural avalanche activity has subsided since Monday's storm however, human triggering remains possible and the likelihood will increase as the sun warms the snow surface. A field team was able to ski cut size 1 slabs on small unsupported features on Wednesday.
Snowpack Summary
Up to 40cm of recent snow is now settling over a variety of old surfaces (wind affect, sun crust and/or surface hoar) and will take longer to bond where it sits on a crust/surface hoar. Below this is a generally strong snowpack however the basal weakness of rounding facets/decomposing crust persists near the ground and should not be left out of your decision making.
Weather Summary
Building high pressure will maintain calm weather through the remainder of this week with light winds and no significant precipitation.
Thurs: mix of sun and cloud, no precipitation, Alp high -8*C, light east winds, FZL 1300m
Fri: mix of sun and cloud, no precipitation, Alp high -5*C, light south winds, FZL 1600m
Sat: mix of sun and cloud, no precipitation, Alp high -4*C, light south winds, FZL 1800m
Terrain and Travel Advice
- Avoid sun exposed slopes, especially if snow surface is moist or wet.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Storm Slabs
The recent snow from Monday is sitting over a crust or surface hoar and in some locations a combination of the two. This combo is ideal for wide propagation and could produce large avalanches. This layer has been reactive in tests and to skier traffic and will become easier to trigger on solar slopes as they warm up.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
As the sun heats up solar slopes expect the surface snow to loose stability and trigger easily in steep terrain.
Aspects: South East, South, South West, West.
Elevations: Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The deep persistent weak layer will require a large trigger to fail, a storm slab avalanche in motion could be enough to do this. An avalanche on this layer would be very destructive, likely run full path or further, and be of high consequence.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 16th, 2023 4:00PM
