Avalanche Forecast

Issued: Jan 25th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is low, 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

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

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 thin cloud, with easing moderate NW winds. Freezing levels 2500 m with an inversion.

 

WEDNESDAY: Sunny, light NW wind, freezing levels around 2500 m with an inversion. Alpine high of +2.

THURSDAY: Sunny, moderate SW wind, freezing levels around 2500 m with an inversion. Alpine high of +2. 

FRIDAY: A mix of sun and cloud, moderate SW winds. Freezing levels below 1000 m over the day. Alpine high of +1. 

Avalanche Summary

Avalanche activity associated with the sustained warm temperatures has been minimal. On Friday and Saturday, small loose wet avalanches were observed out of steep south and east facing terrain. 

Explosive control work over the last 4 days produced cornices up to size 2.5 on all aspects. Natural and skier triggered wind slabs size 1.5-2 were reported on Friday.

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.

The widespread and robust January 16 melt-freeze crust sits up to 30 cm deep, as high as 2100 m. There have been some observations of surface hoar sitting on the crust on polar aspects at treeline and in the alpine north of Pemberton but this does not appear to be widespread. At lower elevations, the previously rain soaked upper snowpack is moist or wet and may be capped with a breakable crust.

The depth of the early December crust/facet layer is highly variable through the region but appears to be typically down 100-200 cm. Some operators are showing the depth as low as 60 cm in shallow snowpack areas and as deep as 3 m in wind loaded terrain. The weak layer is most prominent between 1700 and 2100 m. 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

  • Carefully evaluate steep lines for wind slabs.
  • Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
  • Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches
  • Cornices become weak with daytime heating or solar exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent winds have varied in direction, expect wind slab on all aspects. These isolated pockets of wind slab at higher elevations may remain reactive to human triggers in immediate lee terrain near ridge crest or in extreme terrain.

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

Unlikely - Possible

Expected Size

1 - 1.5

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