Avalanche Forecast
Issued: Mar 16th, 2020 4:26PM
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
A cooler day on Tuesday should reduce solar inputs but daytime heating could be an issue if the skies clear. Watch for lingering wind slabs and avoid steep shallow snow pack areas. Good skiing can be had in sheltered terrain. Enjoy!
Summary
Weather Forecast
Some increased winds Monday night but then back to light winds generally from the North on Tuesday with a few light flurries in the afternoon. Alpine and treeline temperatures between -8 to -4' C and valley bottom temperatures near freezing. Solar inputs will be limited but can heat things quickly if the skies are more clear than expected.
Snowpack Summary
Sun crust on steep solar aspects. 15-20 cm of soft snow over a firm mid pack has been redistributed by moderate winds from various directions (SW, N and E). Wind slabs are present in steep lee areas, with wind effect on many open slopes above treeline. In shallow snowpack areas the weak basal facets remain a concern.
Avalanche Summary
A few small solar triggered slides were observed out of steep rocky terrain Sunday and Monday. Several slab avalanches from size 1.5-2.5 were observed Sunday on steep SW cross loaded shallow slopes and highlight the basal weakness in shallow areas. A cornice failure also triggered the deep persistent layer on the NE side of Observation Pk.
Confidence
The weather pattern is stable
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.
- Variable winds may create pockets of wind slab in some unexpected locations.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
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 mid and upper snowpack is 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 17th, 2020 4:00PM
