Avalanche Forecast

Issued: Mar 4th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Wind slabs are likely to be encountered at upper elevations and may be reactive to human triggering, especially in lee features. Watch for signs of instability such as whumpfing, cracking and recent avalanches.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

THURSDAY NIGHT - Mainly cloudy with isolated flurries / strong southwest wind / alpine low temperature near -8 / freezing level 1200m, dropping to valley bottom overnight

FRIDAY - Mainly cloudy with flurries starting in the afternoon, 5 cm / strong southwest wind easing to moderate southeast in the afternoon / alpine high temperature near -6

SATURDAY - Cloudy with sunny periods / moderate south wind / alpine high temperature near -7 

SUNDAY - Mainly cloudy / light west wind / alpine high temperature near -7 

Avalanche Summary

On Wednesday there were no new avalanches reported for most of the region. There was a potential natural avalanche cycle in the southwest part of the region, near the boundary with the Northwest Coastal region. The area in question received recent snowfall amounts that were similar to the Northwest Coastal region.

On Sunday, a few natural wind slab avalanches were reported up to size 2 at treeline and in the alpine on northeast and northwest aspects. Wind slabs were also easily triggered on leeward slopes by the weight of a person. Numerous loose wet avalanches were observed from steep terrain features. 

On Saturday, we received some fantastic MIN reports showing significant wind effect and wind loading at upper elevations. Natural avalanches were reported as well as a human-triggered slab size 1.5. 

Thank you for the MIN reports!!

Snowpack Summary

The region has received 30-40 cm of new snow over the past few days. Fresh winds slabs may be reactive on leeward slopes at upper elevations, while touchy storm slabs may be found in isolated wind-sheltered locations. Solar aspects may have a thin sun crust and below treeline elevations are seeing a melt-freeze crust.

60-90 cm of snow sits on a variety of old snow interfaces consisting of hard wind-affected snow in exposed terrain and weak, faceted snow or possibly surface hoar in sheltered terrain. Recent reports suggest that the new snow is bonding to these layers.

Faceted snow at the base of the snowpack exists in much of the region. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong southwest winds are expected to continue and may form fresh and reactive wind slabs in leeward terrain.

Aspects: North, North East, East, South East.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Mar 5th, 2021 4:00PM