Avalanche Forecast
Issued: Jan 27th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Ongoing flurries likely won't amount to much new hazard other than in areas where wind loading occurs. Watch for small but touchy new wind slabs forming in the immediate lee of ridges and exposed terrain features.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
Wednesday night: Cloudy with continuing scattered flurries bringing up to 5 cm of new snow. Light southwest winds.
Thursday: Cloudy with continuing scattered flurries and about 5 cm of new snow, easing overnight. Light variable southeast to southwest winds. Alpine high temperatures around -10.
Friday: A mix of sun and cloud. Light south or southeast winds. Alpine high temperatures around -12.
Saturday: A mix of sun and cloud. Light to moderate southeast winds, increasing over the day and overnight. Alpine high temperatures around -13.
Avalanche Summary
On Sunday in Glacier National Park, a skier triggered a size 2 avalanche upon entrance into a cross-loaded terrain feature. Other recent avalanche activity includes small size 1-1.5 wind slabs, a few large cornice failures, and loose dry sluffing in steep and southerly terrain.
We're continuing to track a layer of surface hoar from early January, the most recent activity reported on this layer was January 17 from Clemina Creek documenting cracking and propagation in sheltered treeline and below treeline areas on surface hoar buried 40-50 cm deep. Now trending unreactive, this is a layer we will continue to monitor.
Snowpack Summary
A few cm of low density snow has covered a widespread layer of weak surface hoar that has grown up to 15 mm in some areas. This surface hoar grew on a variety of surfaces that include heavily wind affected surfaces in exposed terrain as well as more variable wind affected and faceted snow in sheltered spots. A thin sun crust may be found on steep solar aspects. Below 1600 m, 20-30 cm of snow is settling above a decomposing melt freeze crust.Â
Observers continue to find a preserved layer of surface hoar down 40-70 cm in sheltered, open slopes at and below treeline. Recent snowpack tests have produced sudden results on this layer, other tests have found it unreactive, as such it continues to warrant slope-specific assessment.Â
Deeper in the snowpack, a couple of older persistent weak layers may still be identifiable from late and early December, consisting of surface hoar and a crust with faceted snow and buried anywhere from 100-200 cm deep. Prolonged periods of inactivity and unreactive snowpack test results suggest that these layers have trended towards dormancy.Â
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Wind Slabs
As flurries continue, small new wind slabs may form in leeward pockets at ridgecrests and around exposed terrain features.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 28th, 2021 4:00PM
