Avalanche forecast

Coquihalla

Feb 14 – 15, 2023Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Dangerous avalanche conditions exist in the alpine and treeline where storm snow and strong winds have built reactive wind slabs.

Be alert to conditions that change with aspect and elevation, especially on slopes being impacted by direct sun. Periods of intense solar radiation could quickly initiate a natural avalanche cycle.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    20 cm of new snow and southwesterly winds have built cohesive slabs on lee slopes. Slabs will likely be the deepest and most reactive on north and east aspects at treeline and above. Use extra caution as you transition into wind-affected terrain. Wind slabs may be sitting on a crust making them especially reactive to ridder triggering.

    Monday night winds switch to light winds from the north. Watch for winds reverse-loading exposed features at higher elevations as you travel through terrain tomorrow.

    During periods of direct sun watch for slab properties increasing in surface snow. Minimize exposure to steep sun-exposed slopes, especially when solar radiation is strong.

Confidence

Moderate

Avalanche Summary

Poor visibility Sunday kept operators from seeing avalanche activity at higher elevations.

On Saturday two notable wind slab avalanches were reported. First, a machine accidental, size 2-2.5, wind slab avalanche on a northeast aspect at 1900 m. See this great MIN report for photos. Second was a natural, size 2, windslab avalanche that initiated in steep northeast facing terrain. The avalanche ran off some cliffs and triggered a second slab below them.

Please continue to post your reports and photos to the Mountain Information Network.

Snowpack Summary

20 cm of new snowfall brings storm snow totals to 70-100 cm. At higher elevations, strong southwest winds are building deep pockets of windslab in lees.

A melt-freeze crust formed in mid-January is now buried up to 100 cm deep. At the moment this layer appears to be gaining strength though in isolated areas small facets are still found above the crust. The snow below this layer is consolidating nicely. Buried 120-150 cm is another layer of concern, a crust, formed near the end of December.

Snowpack depths are below seasonal averages. Total amounts range from 150 to 200 cm at treeline, but decrease significantly below 1500 m.

Weather Summary

Monday Night

Partly cloudy, clearing by morning. Isolated convective flurries, 2-3 cm accumulation. West winds switch to the north 20-40 km/h. Treeline temperatures low -10 °C. Freezing levels drop from 800 m to valley bottom tonight.

Tuesday 

Sunny with cloudy periods. Winds north 20 km/h. Treeline temperatures -8 °C and freezing levels of 900 m. 

Wednesday 

Sunny. Winds west 20 km/h gusting 40 km/h. Treeline temperatures -7 °C and freezing levels of 600 m. 

Thursday

Mix of sun and cloud. Winds southwest 20 km/h gusting 40 km/h. Treeline temperatures -3 °C and freezing levels of 1000 m. 

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Approach lee and cross-loaded slopes with caution.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Regions covered