Avalanche Forecast
Issued: Mar 20th, 2020 4:20PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Tim Haggarty,
Parks Canada
The effects of solar heating should start to diminish Saturday with increasing cloud and light flurries through the weekend. Be mindful of the small windslabs and remain cautious with thin areas.
Summary
Weather Forecast
Saturday will dawn clear at around -10C in the alpine. Friday's moderate SW winds will back off through the day Saturday while cloud increases in the afternoon to give a few flurries. Temps will be a bit cooler than Friday reaching freezing at 1500m. Similar conditions for Sunday as the winds pick back up to moderate to strong in the alpine.
Snowpack Summary
5-10cm of snow that fell Wednesday now has a suncrust on solar aspects. Widespread wind effect in the alpine from recent multidirectional winds. In shallow snowpack areas the weak basal facets remain a concern.
Avalanche Summary
Several solar triggered small loose avalanches observed Wednesday and Thursday. Otherwise, no new avalanches observed or reported.
Our observations are very limited and we appreciate your reports to the MIN.
Confidence
Problems
Wind Slabs
Recent snow and winds from variable directions have developed wind slabs in lee areas on a variety of aspects. These are generally small but remain possible to trigger. Use caution with 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.
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 21st, 2020 4:00PM
