Avalanche Forecast

Issued: Mar 27th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Watch for changing conditions throughout the day as you move through elevation bands.

Elevated freezing levels and afternoon sun increases potential for wet avalanche activity, while storm snow at higher elevations is expected to remain sensitive. 

Summary

Confidence

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

Weather Forecast

SUNDAY NIGHT: Mostly cloudy with 5-10 cm of snow above 1800 m. Accumulations favour the Brandywine area. Moderate southwesterly winds. 

MONDAY: Mostly cloudy with flurries possible. freezing levels remain elevated around 2000 m. Light northeast winds.

TUESDAY: Mostly clear with increasing cloud. Light southwesterly winds. Freezing levels approach 2000 m. 

WEDNESDAY: Freezing levels fall to 1200 m. A mix of sun and cloud with moderate westerly winds. Light snowfall. 

Avalanche Summary

On Saturday, small loose wet avalanches were naturally triggered by raised freezing levels and short periods of sunshine. At higher elevations new storm slabs were triggered to size 1, reactive to human triggers. Similar activity is expected to continue on Monday. 

A large avalanche was reported on a steep alpine slope near Blackcomb on Thursday, likely failing on the mid February weak layer, now buried around 80 cm deep. While the trigger is unknown, it's likely that warming and strong sun had weakened the snowpack. 

Snowpack Summary

Freezing levels have remained around 2000 m for the last few days, as a result moist snow exists below on all aspects. Above 2000 m, storm slabs result on wind affected surfaces in shaded alpine areas, and on a sun crust on south facing slopes. Storm accumulations near Whistler range from 15-30 cm, with higher accumulations north of the Jervis Inlet. 

70 to 110 cm overlies the mid March interfaces. This layer exists as surface hoar in shady, wind-sheltered areas and a hard crust on sun-exposed slopes into the alpine. Several other weak layers exist in the upper and mid snowpack, reports suggest these layers are bonding well and avalanche activity is unlikely except from large loads like cornice falls. 

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be alert to conditions that change with aspect and elevation.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Loose Wet

An icon showing Loose Wet

As sunshine and warm temperatures weaken the surface snow, wet avalanches become more likely. Watch for wet and heavy surface snow. 

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs

Recent storm snow will likely be most reactive on south facing slopes, where slabs sit over a crust. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices may become weak with rising temperatures. Cornice falls are hazardous on their own, and have the potential to trigger large avalanches on the slope below. 

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Mar 28th, 2022 4:00PM