Avalanche Forecast
Issued: Mar 30th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs.
wlewis,
Avalanche Canada
A weak snowpack still exists throughout this region.
Avoid thin and rocky start zones.
Summary
Confidence
Moderate
Avalanche Summary
Wet loose avalanches have occurred over the last 3 days, on steep sun affected slopes as freezing levels rose with strong sunshine.
No activity on the deeply buried weak layers has been reported this week. Kananaskis Country and the central Rockies continue to report very large deep persistent avalanches, including a size 3 natural on the 28th of March in Highwood Pass. Thin and rocky terrain features in the upper treeline and alpine should still be avoided.
Snowpack Summary
Moist snow exists on the surface at most elevations. At high elevations on shaded slopes, dry snow may still exist. Below this, a crust exists on solar aspects, and faceted snow and surface hoar up in shaded and wind-sheltered areas.
In the middle of the snowpack, there are lingering persistent weak layers, including surface hoar in wind-sheltered terrain and a sun crust on south aspects. These layers have not shown recent reactivity, but may still be triggerable in isolated areas and should be on your radar, particularly in the Purcells part of the region.
The lower snowpack is made up of a widespread layer of large, weak basal facets and depth hoar in some areas, which produced large avalanches in the Elk Valley and the neighboring region of Purcells last week. Kananaskis Country reports continued avalanche activity on this layer.
Weather Summary
Thursday Night
Freezing levels drop back to 500 m, with light westerly winds around 10 km/hr. Partly cloudy skies.
Friday
Mostly cloudy with flurries delivering up to 5 cm of snow. Light southerly wind gusting 40 km/h. Freezing level rises to 1500 m. Alpine temperatures of -5 °C.
Saturday
Cloudy with sunny periods possible in the afternoon. Light snowfall brings 5-10 cm. Light southwesterly wind gusting 40 km/h. Freezing level rises to 1500 m. Alpine temperatures of -5 °C.
Sunday
Cloudy with up to 5 cm of snow. Light southwest winds. Freezing levels around 1300 m, alpine highs of -7 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Conditions may have improved, but be mindful that deep instabilities are still present.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Deep Persistent Slabs
The base of the snowpack remains very weak. Very large human-triggered avalanches are possible at treeline and above. Avoid thin, rocky start zones and shallow areas with variable snowpack depths. Weak layers are most triggerable here as they sit closer to the surface of the snowpack.
Give careful consideration to the slopes overhead as large avalanches may run well into the runout zone or into lower-angle terrain.
Deep persistent avalanches are challenging to predict. This layer can suddenly become active again, typically when there is rapid change or stress to the snowpack - sudden warming, heavy snow or rainfall, or heavy loads eg. cornice fall.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 31st, 2023 4:00PM
