Avalanche Forecast
Issued: Jan 23rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
dsaly,
Avalanche Canada
Avalanche hazard is improving, stick to good travel habits. Be wary of lurking wind slabs and large cornices.
Summary
Confidence
Weather Forecast
Saturday night: Patchy cloud / light southwest winds / alpine low temperature -18
Sunday: Mostly cloudy, isolated flurries / light southeast winds / alpine high temperature -12
Monday: Cloudy with sunny breaks / light east winds / alpine high temperature -11
Tuesday: Cloudy with sunny breaks / light southeast winds / alpine high temperature -10
Avalanche Summary
Outside of a handful of small size 1-1.5 wind slabs, a few cornice failures, and loose dry sluffing in steep and southerly terrain, there have been no notable avalanche reports in the region.
On Wednesday, operators in neighboring Glacier National Park reported several large (size 2-2.5) wind slabs releasing naturally on a variety of aspects (north, east, and south). Two natural cornice failures were reported in Glacier National Park on Wednesday releasing above north-facing slopes.
This MIN from Clemina Creek last weekend reports that the Jan 11th surface hoar was cracking and propagating in sheltered treeline and below treeline areas where it was buried 40-50 cm deep. Now less reactive, this is a layer we will continue to monitor.
Snowpack Summary
Previous winds scoured snow surfaces, loaded cornices, and formed stiff wind slabs in the alpine and around treeline. A thin sun crust may be found on steep solar aspects. Clear skies and cold temperatures are encouraging surface hoar growth and surface faceting. Below 1600 m, 20-30 cm of snow is settling above a decomposing melt freeze crust.
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.
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.
Terrain and Travel
- Carefully evaluate steep lines for wind slabs.
- Large cornice falls are dangerous on their own.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Wind Slabs
Wind slabs are stubborn, but if triggered will be heavy and dense. Use caution around cornices.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar buried Jan 11 may be found 40-70 cm deep on open, sheltered slopes near and below treeline. There is uncertainty as to the distribution and reactivity of this persistent slab problem across the region.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Jan 24th, 2021 4:00PM
