Avalanche Forecast
Issued: Mar 15th, 2020 4:04PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Deep Persistent Slabs and Loose Wet.
Conrad Janzen,
Parks Canada
Watch for the effects of daytime heating on steep solar slopes and continue to avoid steep shallow snowpack areas where the basal weakness is most likely to be triggered. Enjoy the great skiing and travel conditions!
Summary
Weather Forecast
Sunny skies and warmer temperatures on Monday with treeline temperatures between -10 and -2'C. Wind will generally be light from the North all day. Valley bottom temperatures may climb above freezing and solar inputs will likely start to affect steep sunny slopes by mid morning.
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 above treeline. On some steep solar aspects a thin sun crust is present. In shallow snowpack areas the weak basal facets remain a concern.
Avalanche Summary
Three new slab avalanches from size 2-2.5 on Hector, Castle and Cory were observed Sunday. All three of them were on steep SW cross loaded shallow slopes and highlight the basal weakness in shallow areas. A few small solar triggered sluffs were also observed out of steep rocky terrain. A couple smaller wind slab avalanches were observed Saturday.
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.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
We expect to start seeing some wet loose avalanche activity on steep rocky solar slopes in the next couple days. Watch for these as possible triggers on the slopes below, and minimize exposure to this in steep gullies or on ice climbs.
Aspects: South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 16th, 2020 4:00PM
