Avalanche Forecast
Issued: Mar 11th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
ldreier,
Avalanche Canada
Buried weak layers remain possible to be triggered, where they still exist. Rising temperatures and solar input may increase the reactivity of these layers. Be alert to conditions that change with sun exposure.
Summary
Confidence
Weather Forecast
THURSDAY NIGHT: Clear, 20 km/h southwest wind, alpine low -10 C, freezing level at valley bottom.
FRIDAY: Sunny, 20 km/h southwest wind, alpine high +1 C, freezing level rising to 1900 m.
SATURDAY: Sunny, calm wind, alpine high +7 C, freezing level 2700 m.
SUNDAY: Sunny, 15 km/h south wind, alpine high +8 C, freezing level 2700 m.
Avalanche Summary
A few small loose and slab avalanches were triggered on sun-exposed slopes in the alpine during the heat of the day on Wednesday.
Snowpack Summary
A few centimetres of snow overlies a thick melt-freeze crust in many areas, with the exception being on north aspects above around 1700 m. Wind slabs may still exist on northerly aspects at alpine and treeline elevations. On solar aspects and below the freezing level, the snow may moisten during the heat of the day. Cornices may also weaken over the day.
Around 30 to 50 cm of snow overlies a variety of old interfaces that formed in mid-February. There hasn't been recent avalanche activity on this layer, but it remains possible to be triggered where it exists. The more active layer was buried late January, which is found 50 to 100 cm deep. This layer is mostly composed of sugary faceted grains, hard wind pressed snow, feathery surface hoar in wind-sheltered locations, and a melt-freeze crust on steep solar aspects. Periodic avalanches continue to be triggered on this layer. Check out this MIN for a photo of the positioning of these layers in the snowpack.
Terrain and Travel
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Cornices become weak with daytime heating or solar exposure.
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Persistent Slabs
Two weak layers may exist between 30 and 100 cm deep. Widespread avalanche activity has already occurred on the layers, but they could still be triggered anywhere they haven't already failed. Look for signs of instability and continue treating the snowpack as suspect if you are uncertain whether the layer is still present in your riding area. The rising temperatures may increase the reactivity of these layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 12th, 2021 4:00PM
