The likelihood of triggering the late-January weak layer has decreased but it remains reactive to snowpack tests in the north of the region and still may be capable of producing large avalanches in isolated areas.
Watch for thin new wind slab formation in exposed high elevation terrain in the south of the region.
Thin new wind slabs may have formed on Monday in the south of the region. These could be more reactive than normal given the hard crust they are sitting on.
The late-January weak layer is down 20-70 cm and was most reactive between 1700 and 2000 m in the north of the region. It is now likely dormant in most 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.
An offshore ridge of high pressure brings dry conditions with periods of sun.
Monday night: Mainly cloudy, light to moderate NW wind, freezing levels around 1500 m.
Tuesday: Mainly sunny, light to moderate NW wind, freezing levels around 1500 m.
Wednesday: A mix of sun and cloud, light to moderate NW wind, freezing levels reaching 1500-2000 m.
Thursday: Cloudy with a chance of flurries, moderate SW-NW wind, freezing levels reaching 1200-1600 m.
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. Around the Coquihalla, some glide slab avalanches were observed. Small loose wet avalanches were also observed from steep sun-exposed slopes throughout the region.
The new snow has buried a widespread surface crust and wind-affected surfaces in exposed high elevation terrain. The melt-freeze crust is reported to exist on all aspects and elevations except for some of the highest elevation polar aspects in the north of the region which may still hold dry snow. The crust was reported to be undergoing faceting in some areas prior to the snowfall.
The late-January crust/facet/surface hoar interface is buried down 20-70 cm. This layer was most reactive between 1700 m and 2000 m in the north of the region. 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 in the north of the region and would still be capable of producing large avalanches if triggered.
