Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Jan 23rd, 2021–Jan 24th, 2021

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.

Regions

North Columbia.

Avalanche hazard is improving, stick to good travel habits. Be wary of lurking wind slabs and large cornices.

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected.

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 Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.