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Avalanche Forecast

Jan 29th, 2022–Jan 30th, 2022
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
4: High
The avalanche danger rating below treeline will be high
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: Sea To Sky.

Avoid avalanche terrain, natural avalanche activity is expected on Sunday with continuous heavy precipitation.

Touchy storm slabs will form over a variety of weak surfaces - smooth crusts, delicate surface hoar and weak facetted snow. 

Confidence

High - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather. Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

A front stalls across the coast Saturday night, bringing moderate snowfall and wind before moving on Sunday afternoon.

SATURDAY NIGHT: Cloudy, with moderate southwest winds. Snowfall begins overnight, bringing 10-25 cm by morning. Freezing levels at 800 m. 

SUNDAY: Snow continues, 20-50 cm by Sunday afternoon. Freezing levels remain below 1000 m. Winds remain strong from the southwest. Alpine high -3.

MONDAY: Possible flurries with mostly cloudy skies. Moderate westerly winds. Alpine high of -4. Freezing levels sit below 800 m. 

TUESDAY: A mix of sun and cloud. Moderate northerly winds. Freezing levels 500 m. Alpine high -6.

Avalanche Summary

Widespread natural activity is expected as a result of the heavy precipitation forecast for Sunday. 

Explosive control work near Whistler on Tuesday produced a cornice fall that triggered a size 2.5 deep persistent slab on the weak facetted crystals above the early December crust. The slab was 60-130cm deep. This indicates that while the weak layer is unlikely to be affected by skiers and riders, it is still triggerable by very large loads. 

Snowpack Summary

Storm snow sits over a thick melt freeze crust sits on the surface on all aspects up to approximately 2200 m. Surface hoar is reportedly sitting above the crust, expect increased reactivity of storm slabs in sheltered and shaded areas at treeline and below.

At higher elevations storm snow will sit over dry snow on shaded north facing aspects, and a thin melt freeze crust on sunny southern aspects.

The early December crust/facet layer can be found around 100-200 cm deep, most prominent between 1700 and 2100 m. This layer showed no reactivity from the warming event last weekend and is currently classified as dormant. Large loads may still be able to trigger avalanches on this layer.

Terrain and Travel

  • Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
  • Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.

Avalanche Problems

Storm Slabs

Storm snow will fall on a smooth crust. In sheltered areas at treeline and below, a weak and reactive surface hoar layer sits above the crust - increasing likelihood of natural and human triggered avalanches. 

Travel in avalanche terrain is not recommended. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely - Almost Certain

Expected Size: 1.5 - 3