Avalanche forecast

Purcells

Dec 23 – 24, 2022Avalanche Canada
View on map
Archived · expired 4 years ago

Avalanche danger

Sun
Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map

Highlights

Assess exposed slopes for wind slab. Strong winds will likely redistribute the loose surface snow into new wind slabs.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Strong southwest winds will likely form new wind slabs in exposed terrain at treeline and above. These slabs will be found on east and north slopes sitting above facets. this layer of facets will mean wind slabs could be touchy and propagate wider than expected.

    Strong winds can move snow further down slope . It is possible that wind slab may not be felt right below ridge top, you may encounter it a few meters into the slope.

    Wind slab avalanches could step down to deeper layers.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1.5–2.5

    A layer of surface hoar, facets and, a crust from mid November is buried around 40 cm deep but can be found down as much as 80 cm. This layer has become hard to trigger but could still be sensitive to rider traffic on isolated slopes at treeline and below where the snow above feels stiff and consolidated.

Confidence

Moderate

Avalanche Summary

On Tuesday and Wednesday explosive control in the region produced only very small avalanches with a depth of 10cm.

If you are headed into the backcountry please consider filling out a Mountain Information Network report.

Snowpack Summary

Southwest winds will likely form new wind slabs on north and east aspects. These slabs will form over a layer of facets meaning they will not bond well. As winds reach the strong range wind slabs could form lower down slope than expected.

The main layer of concern is the mid-November layer, which is made up of either surface hoar, facets, or crusts. It is now buried 40 to 80 cm deep. Avalanche activity on this layer has tapered off but it could still be possible to trigger this layer in isolated terrain features near treeline.

Alpine snowpack distribution is variable, with depths ranging from 70 to 140 cm.

Weather Summary

Thursday Night

Light flurries bringing trace amounts of new snow. Moderate southwest winds and a low of -29 at 2000m.

Friday

Cloudy with up to 5cm of new snow expected. Strong southwest winds and a High of -25 at 2000m.

Saturday

Cloudy with flurries bringing up to 5cm of new snow. Strong southwest winds and a high of -20 at 2000m.

Sunday

A mix of sun and cloud with flurries bringing trace amounts of new snow. Moderate southwest winds and a high of -14 at 2000m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Regions covered