Avalanche Forecast

Issued: Jan 15th, 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 Persistent Slabs.

Avalanche Canada jleblanc, Avalanche Canada

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Travelling conditions are challenging ; from thin breakable crust to thick supportive crust. Adjust your plan and objective to stay safe.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

SATURDAY NIGHT: Mostly cloudy, strong west wind, treeline high around -3 C, freezing level around 1600 m.

SUNDAY: A mix of sun and clouds, moderate west wind increasing to extreme, treeline high around -6 C,freezing level at valley bottom rising to 1000 m by midday.

MONDAY: Cloudy with sunny periods, treeline high around -3 C, strong southwest wind, freezing level around 1500 m.

TUESDAY: Snow, 5-10 cm, light to moderate variable winds, treeline high around -8 C, freezing level returning to valley bottom.

Avalanche Summary

No new avalanches were observed nor reported in the last 24 hours.

Thursday, three very large avalanches were reported from this region. The avalanches appear to have failed on the early December crust and showed wide propagation. They occurred on southwest to southeast aspects and were naturally triggered in response to rising temperatures and solar radiation.These avalanches follow a previous sporadic pattern of very large avalanches that have been reported from this region and neighbouring regions over the last couple of weeks. 

Snowpack Summary

Fresh dry snow is potentially found at upper elevation. Around 2000 m and below, a crust is now capping the dense 15 cm of snow which is continuing to settle with the mild temperatures. The crust varies from thin/breakable to thick/supportive, according to the aspects and elevation. Under it, the snowpack consists of a variety of old surfaces, including soft snow in sheltered areas and wind slabs in exposed and open areas, which formed over the past few days.

The most notable layer of concern in the snowpack is a crust that was formed in early December and is now down 100-270 cm. This layer appeared to have "waken up" in response to warm temperatures and solar radiation on Thursday Jan 13, when at least three very large avalanches were reported on this layer. This layer has created a low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques.

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Be alert to conditions that change with elevation and wind exposure.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Exposed slopes at higher elevations will continue to see effects from the winds. Lingering and new wind slabs could remain reactive in open areas. While these slabs may be thin, they could be poorly bonded to the underlying snow, so be extra cautious in lee terrain and convex rolls.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A persistent slab problem formed by a crust down 100-270 cm has created a low likelihood, high consequence scenario that is difficult to forecast. There has been an increase of avalanche reports on this layer recently. Although a cooling trend means the snowpack is slowly gaining strength, it is uncertain how the recent warming/rain has affected the snowpack. In the meantime, avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack. The same feature or path can slide repeatedly when the persistent weak layer is reloaded with new snow. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Jan 16th, 2022 4:00PM

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