Avalanche Forecast

Issued: Mar 26th, 2022 4:00PM

The alpine rating is considerable, the treeline rating is considerable, 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. 

Rain at lower elevations increases potential for wet avalanche activity, while storm slabs may build at treeline and above.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain. Uncertainty is due to rapidly fluctuating freezing levels.

Weather Forecast

SATURDAY NIGHT: Mostly cloudy. Freezing levels rise to 1800-2000 m overnight, with up to 10-20 cm expected above and rain below. Freezing levels around 1500 m. Moderate southerly winds.

SUNDAY: Mostly cloudy with 5-15 cm of snow. Freezing levels remain high, around 2000 m. Moderate to strong southwesterly winds. 

MONDAY: Another 5-15 cm possible overnight. Clearing during the day with flurries delivering up to 5 cm, freezing levels remain around 1500-1800 m. Light northeast winds.

TUESDAY: Mostly clear with increasing cloud. Light southwesterly winds. Freezing levels reach 2500 m. 

Avalanche Summary

On Friday, isolated small wind slabs and cornice falls were reported at treeline and alpine elevations. 

Warm temperatures, rain and sun on Tuesday, Wednesday and Thursday produced large wet avalanches on all aspects below the freezing line, and on steep sun affected slopes. Similar activity is expected with this approaching weather system. Human and naturally triggered cornice falls were also reported over the week. Cornices are expected to be weak and reactive to human triggers. 

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

Mixed precipitation and snow will fall on a melt freeze crust that extends into the alpine on all aspects to 2000-2500 m and on south facing slopes to mountain top. On shaded aspects new snow will sit over wind affected surfaces. Lower elevations will likely see moist surfaces as rain breaks down the crust. 

40 to 90 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

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Watch for fresh storm slabs building throughout the day.

Problems

Loose Wet

An icon showing Loose Wet

As rainfall and warm temperatures weaken the surface snow, wet avalanches become more likely. Avoid terrain features with wet and heavy surface snow. 

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices may become weak with rain and 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, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Mar 27th, 2022 4:00PM

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