Avalanche Forecast

Issued: Feb 14th, 2022 4:00PM

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

Avalanche Canada rbuhler, Avalanche Canada

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The likelihood of triggering the late-January weak layer has decreased but it remains reactive to snowpack tests and still may be capable of producing large avalanches in isolated areas. 

Summary

Confidence

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Weather Forecast

An offshore ridge of high pressure brings dry conditions with periods of sun. There is some warm air aloft expected just offshore and uncertainty whether it will affect the region. 

Monday night: Clear, light to moderate N wind, freezing levels around 1500 m.

Tuesday: Mainly sunny, light NW wind, freezing levels as high as 1600 m with an inversion. 

Wednesday: A mix of sun and cloud, moderate NW wind, freezing levels potentially reaching 2000 m with an inversion. 

Thursday: Cloudy with a chance of flurries, light W wind, freezing levels around 1200 m.

Avalanche Summary

On Sunday, several natural cornices were observed in the north of the region, some of which triggered size 1-2 slabs on the slopes below. Small loose wet avalanches were also observed from steep sun-exposed slopes. 

On Saturday, a natural size 2 cornice release was reported from a steep, rocky NW aspect at 2100 m. A variety of loose wet avalanches were reported from steep, sun-exposed slopes. Explosives triggered four cornices up to size 2. 

Snowpack Summary

A dusting of new snow has buried a widespread surface crust and wind-affected surfaces in exposed high elevation terrain. The new melt-freeze crust is reported to exist on all aspects and elevations except for some of the highest elevation polar aspects which may still hold dry snow. The crust is reported to be undergoing faceting in some areas. 

The late-January crust/facet/surface hoar interface is buried down 30-70 cm. This layer was most reactive between 1700 m and 2000 m. While this layer now appears to be dormant in many parts of the region, recent snowpack tests suggest it is still very reactive in a few places and would still be capable of producing large avalanches if triggered. 

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.

Problems

Persistent Slabs

An icon showing Persistent Slabs

The late-January weak layer is down 30-70 cm and was most reactive between 1700 and 2000 m. It is now likely dormant in many areas, especially where there is a supportive surface crust. However, recent snowpack tests suggest it is still reactive and capable of producing large avalanches if triggered. We have now entered a low probability, high consequence scenario with this layer. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Feb 15th, 2022 4:00PM