Avalanche Forecast
Issued: Feb 13th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
rbuhler,
Avalanche Canada
The likelihood of triggering the late-January weak layer is decreasing but it remains reactive and capable of producing large avalanches.
Watch for new wind slab formation on Monday in exposed high elevation terrain.
Summary
Confidence
Weather Forecast
The warm air exits the region Sunday overnight. A weak storm system is expected to bring light snowfall for Monday morning before clearing in the afternoon.
Sunday night: Increasing cloud cover, moderate SW wind, freezing levels falling to around 1000 m.
Monday: Snowfall in the morning up to 15 cm, sunny in the afternoon, moderate SW wind becoming light NW, freezing levels reaching around 1400 m.
Tuesday: Mainly sunny, light to moderate NW wind, freezing levels around 1200 m.
Wednesday: A mix of sun and cloud, light to moderate NW wind, freezing levels as high as 2000 m with an inversion.
Avalanche Summary
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.
On Friday, a few natural cornice releases were reported, some of which triggered small slabs on the slopes below. Some natural loose wet avalanches were also reported from steep sun-exposed slopes. In the northwest of the region, explosives triggered three moist storm slabs 10-40 cm thick on solar aspects and two cornices which triggered small slabs on the slopes below. Further south, explosives triggered wind slabs up to size 2 failing down 60 cm.
Snowpack Summary
Monday's snowfall will bury 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 still 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.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs may be poorly bonded to the underlying crust.
Problems
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
Expected Size
Wind Slabs
Thin new wind slabs may form on Monday. These could be more reactive than normal given the hard crust they may be sitting on.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 14th, 2022 4:00PM
