Avalanche Forecast
Issued: Mar 14th, 2020 4:33PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Conrad Janzen,
Parks Canada
Good travel conditions but cold temperatures on Sunday. Ensure you are prepared to stay warm in the event of any delay.
Ice climbers should be cautious with steep pillars which often respond poorly to cold temperatures.
Summary
Weather Forecast
Sunny skies and below normal temperatures will remain on Sunday with lows of -25 to -30'C and highs of -8 to -15'C. Wind will generally be light through all of the eastern slopes as the surface ridge stays firmly in place. Solar inputs may warm steep sunny slopes to near freezing in the afternoon.
Snowpack Summary
15-20 cm of snow over the last several days has been redistributed by moderate winds from various directions (SW, N and E). New wind slabs are present in steep lee areas, with wind effect on many open slopes. On steep solar aspects a thin sun crust is present. In shallow snowpack areas the weak basal facets remain a concern.
Avalanche Summary
A couple small avalanches were observed Saturday. One natural size 2 slab released on a shallow steep SW aspect near Mt Hector, and a few small sluffs triggering thin thin wind slabs up to size 1.5 were observed near Bow Summit out of steep rocky terrain. Ski hills were able to ski cut a few thin wind slabs near ridgetops.
Confidence
Wind speed and direction is uncertain on Monday
Problems
Wind Slabs
Recent snow and variable wind directions (SW, N and E) have developed wind slabs in lee areas on a variety of aspects. These are beginning to bond but use caution if you encounter them in steep terrain, especially in thin snowpack areas.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Variable winds may create pockets of wind slab in some unexpected locations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Use caution in thin snowpack areas averaging 150cm or less. In these areas, the basal snowpack layer of depth hoar and facets remains weak and the overlying mid and upper snowpacks are thin enough to allow for triggering of the deep persistent layer.
- Be aware of thin areas that may propogate to deeper instabilites.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 15th, 2020 4:00PM
