Avalanche Forecast
Issued: Dec 27th, 2019 4:30PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
Lisa Paulson,
Parks Canada
Though natural avalanche activity has tapered off, human triggering remains likely. Choose less committing terrain and avoid large overhead hazard.
There have been a few close calls already this week.
Summary
Weather Forecast
Slightly warmer temperatures for the weekend with a slight inversion on Saturday morning. Expect an alpine high of -8 for Saturday and -4 for Sunday with moderate winds from the West. Skies will remain cloudy with no significant snow accumulations in the forecast.
Snowpack Summary
Surface hoar growth up to 5mm observed below tree line. Moderate SW winds are redistributing the 30-60cm of recent storm snow and forming wind slab on lee aspects. Below the new snow the snowpack structure is generally weak consisting of facets and depth hoar and a Nov crust up to 2500m.
Avalanche Summary
A couple of windslab avalanches in the past 24 hours on alpine Northerly aspects. On Wednesday, explosive avalanche control at Sunshine ski area produced a sz 2 deep persistent slab. Recent reports of skier triggered avalanches within the region and reports of whumphing on the deep persistent layer continue today.
Confidence
Problems
Deep Persistent Slabs
The weak, faceted lower snowpack remains stressed by the new storm snow at all elevations. If triggered the deep facets it will result in a very large avalanche. Reports of whumphing on the basal layer continue.
- Be aware of the potential for full depth avalanches due to deeply buried weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
With 30-60cm of storm snow available for transport accompanied by the moderate to strong SW winds, expect fresh wind slab formation in the alpine and exposed areas at tree line.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 28th, 2019 4:00PM
