In the south of the region, a widespread storm slab may be reactive to human-triggering, especially in wind loaded terrain.
In the north of the region, thin wind slabs should be expected on all aspects in exposed terrain.
A weak layer from late-January is down 40-100 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 crust above.
In the south of the region, a weak layer from mid-February under the recent storm snow is the more concerning buried weak layer.
In the south of the region, 30-50 cm of recent storm snow is expected to be most reactive in wind loaded terrain but a more widespread problem may exist. This snow may be poorly bonded to the underlying crust.
In the north of the region, shifting wind directions means thin wind slabs should be expected on all aspects in exposed terrain.
High pressure remains the dominant feature for the rest of the week. However, a disturbance is expected to move through the region late Wednesday bringing increased cloud cover, shifting winds, and a chance of flurries.
Tuesday Night: Clear, light to moderate N wind, treeline low around -16 °C.
Wednesday: Mainly sunny with increasing cloud in the late afternoon, moderate to strong NW wind, treeline high around -8 °C.
Thursday: Mainly sunny, light N wind, treeline high around -4 °C.
Friday: Sunny, light SW wind, treeline high around -2 °C.
On Monday, several natural wind slabs were observed. In the north, these were limited to size 1. In the south, they were a bit bigger at size 1.5. Loose dry avalanches up to size 1.5 were also observed in the south of the region.
On Sunday in the Coquihalla, a skier-triggered storm slab was reported on a SE aspect at treeline which had a slab depth varying between 20 and 55 cm. The MIN report includes a great photo showing the type of avalanches we continue to expect in the south of the region as ongoing wind continues to redistribute the weekend storm snow. A natural size 2 storm slab was also reported on a SW aspect at 1850 m as well as a variety of small natural and human-triggered loose dry avalanches from steep slopes.
On Sunday in the north of the region, a very small persistent slab avalanche was reported as part of a larger snowpack settlement which occurred at valley bottom near a creek. This failed on the late-January surface hoar down around 40 cm. This suggests that in the isolated areas where large surface hoar is still preserved, the interface may still capable of producing avalanches.
Weekend storm totals were highly variable across the region with around 5-10 cm in the north and around 30-50 cm around the Coquihalla and Allison Pass. During the storm, the wind was blowing from the southwest but has switched to a northeast direction and wind loading should be expected on all aspects in exposed terrain.
The mid-February crust is now down around 20 cm in the north and as deep as 70 cm in the south. The melt-freeze crust is reported to exist on all aspects and elevations, except for high elevation polar aspects in the north of the region. Facets and surface hoar can be found above the crust in the north of the region.
The late-January crust/facet/surface hoar interface is buried down 40-100cm. 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 through most of the region, it may still be possible to trigger it at upper treeline or lower alpine features on polar aspects with a large load like a cornice or in shallow snowpack areas.
