Avalanche Forecast
Issued: Dec 12th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
stephen holeczi,
Parks Canada
Watch locally for fresh wind slabs from recent winds, and don't forget there are weak facets and depth hoar at the bottom of the snowpack that are hard to predict. Good snow quality reported in sheltered areas.
Summary
Weather Forecast
The current strong alpine winds will die right down for Friday with a slow cooling trend (lows -8 to -10) and light flurries. The light winds and cooling trend will continue through the weekend and we will be back to -20C temperatures by Sunday.Â
Snowpack Summary
Moderate to strong winds in the alpine have increased wind slab thickness. Beneath the recent 40-60 cm of storm snow, the snowpack structure is generally weak, consisting of facets and depth hoar. The Nov crust is present up to 2500m and ~30 cm up from ground. Snowpack depths at treeline range from 80-160 cm.
Avalanche Summary
Natural and explosive controlled avalanche activity has tapered form earlier this week which saw a mix of wind slabs and larger avalanches entraining the basal depth hoar and facets to size 3. Visibility was minimal on Thursday so there were no avalanche reports.Â
Confidence
Problems
Wind Slabs
Strong alpine winds in the last 24 hours have increased wind slab thickness and likely their reactivity in many open areas in the alpine and some treeline features. Watch locally for their development as it has not been windy everywhere.
- Use caution in lee areas. Recent wind loading has created slabs over weaker snow.
- Caution on open steep slopes at treeline that have been exposed to wind loading.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The recent snow sits over weak facet and crust layers. As time goes on the chance of triggering is becoming less likely, but there is lots of uncertainty as to where you could trigger an avalanche and what it will take to get it moving.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2019 4:00PM
