Avalanche Forecast

Issued: Jan 24th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Cornices, Wind Slabs and Loose Wet.

Avalanche Canada ahanna, Avalanche Canada

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Soft, dry snow can still be found on shady, wind-sheltered aspects at upper elevations. Avalanche problems exist in specific terrain features. Check the distribution icons in the problems tab for details.

Summary

Confidence

High -

Weather Forecast

The region now sits under a warm ridge of high pressure which is expected to persist through the week bringing sun and upper level above freezing layers (AFL).

Monday night: Clear, light NW wind, freezing levels around 1300 m. 

Tuesday: A mix of sun and cloud, moderate NW wind, freezing levels around 1000 m with a 2000-2500 m AFL. 

Wednesday: Sunny, light NW wind, freezing levels around 2100 m.

Thursday: Sunny, moderate SW wind, freezing levels around 2500 m.

Avalanche Summary

Recent avalanche activity has been limited to small loose wet out of steep solar aspects.

Over the weekend, evidence of natural wind slabs size 1.5-2.5 were observed in the south of the region, suspected to have run at the end of last week.

On Saturday a size 3 glide slab was observed at 2200 m in the north of the region. On Wednesday, a size 1.5 glide slab was observed at 1400 m in the Coquihalla area. Glide slabs are difficult to forecast but they are often a product of sustained warm weather, as melting snow lubricates between the ground and the snowpack.

Snowpack Summary

At upper elevations, moist surfaces or a thin crust can be found on steep solar aspects, while shady aspects hold dry snow - well preserved powder in wind sheltered areas and wind slab in exposed terrain.

Below 2100m, the widespread January 16 melt-freeze crust sits 15-30 cm deep, tapering with elevation. In the south of the region, this crust is one of many in the upper snowpack. There have also been reports of a layer of small surface hoar above the Jan 16 crust in the north of the region on polar aspects at treeline and in the alpine but this does not seem to be widespread. At lower elevations, the upper snowpack is moist or wet and may be capped with a breakable crust.

The early December crust/facet layer is now typically down 100-150 cm but may be as shallow as 60 cm and as deep as 200 cm with lots of variability through the region. The layer is most prominent between 1700 and 2100 m. The crust appears to be breaking down in the south of the region but remains a snowpack feature in the north. After showing no reactivity in the peak of the warming event on the weekend, we cautiously reclassify this layer as dormant for now.

Terrain and Travel

  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Cornices become weak with daytime heating or solar exposure.
  • Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches
  • Minimize exposure to steep, sun exposed slopes, especially when the solar radiation is strong.

Problems

Cornices

An icon showing Cornices

Warm temperatures and strong sun weaken large overhanging cornices. Stay well back of them when travelling on ridges and avoid slopes exposed to overhead cornice hazard.

Aspects: North, North East, East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Reverse loading from recent moderate winds have formed isolated wind slabs in the alpine. These may remain reactive to human triggers in immediate lees near ridge crest or in extreme terrain.

Aspects: East, South East, South, South West, West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Loose Wet

An icon showing Loose Wet

Wet loose avalanches are possible on steep south aspects with warm temperatures and sun. Use caution when the snow on these slopes is moist or wet.

Aspects: South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Jan 25th, 2022 4:00PM