Avalanche Forecast

Issued: Jan 25th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Isolated pockets of wind slab sit at higher elevations - winds have varied so expect loading on all aspects.

Wet loose avalanches remain possible with continued warm temperatures and sun. Step back when surface snow becomes moist and loses cohesion.  

Summary

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected. Uncertainty is due to the limited number of field observations.

Weather Forecast

A high pressure system has established itself across the coast. Clear skies and warm air at higher elevations will persist until Friday.

TUESDAY NIGHT: Scattered cloud, light NW wind, freezing levels around 2300 m.

WEDNESDAY: Sunny, moderate NW wind, freezing levels around 2300 m. Alpine high +2. 

THURSDAY: Sunny, moderate SW wind, freezing levels around 2600 m. Alpine high +2. 

FRIDAY: Increasing cloud with moderate SW wind. Freezing levels drop below 1000 m over the day. Alpine high -1. 

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. They are often a product of sustained warm weather, as melting snow lubricates between the ground and the snowpack.

Snowpack Summary

Higher elevations hold dry snow in the form of lingering wind slabs, mostly on north and east facing slopes. However recent winds have varied, expect winds to have loaded all aspects.

Below 2100m, the widespread January 16 melt-freeze crust sits 15-30 cm deep. 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 in variable areas throughout 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 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.
  • 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.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

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. Check for wind slab on all aspects as winds have varied in direction.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

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 in the heat of the day 

Aspects: South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Jan 26th, 2022 4:00PM