A mid-winter snowpack at and above treeline requires thoughtful terrain selection. We can't forget about the potential for large human triggered slab avalanches that are most likely on south facing terrain at upper elevation.
Summary
Confidence
High -
Weather Forecast
The struggle between "spring-like" and "Arctic-like" will continue for a few more days. Saturday's storm is not expected to produce much snow in the Cariboos. A more spring-like pattern begins to take shape on Sunday with freezing levels creeping towards 2000 m by Monday.SATURDAY: Broken cloud cover, freezing level beginning near valley bottom rising to around 1500 m, light to moderate south/southwest wind, 1 to 2 cm of snow possible. SUNDAY: Broken cloud cover, freezing level beginning near valley bottom rising to about 1600 m, light west/southwest wind, 1 to 2 cm of snow possible. MONDAY: Scattered cloud cover, freezing level beginning around 1500 m rising to about 2000 m, light to moderate west/southwest wind, trace of snow possible.
Avalanche Summary
Reported avalanche activity on Thursday was limited to a size 2 natural cornice failure on a southeast facing slope at 2900 m. On Wednesday a natural size 3 cornice failure was observed on an unknown aspect, the cornice did not initiate any other avalanche activity. Small loose dry sluffing was also observed on south facing aspects between 1500 and 2100 m suggesting that the cool temperatures are preserving cold snow, even on southerly aspects.Explosives control in the region yielded several persistent slab (size 3) and shallower storm slab (size 1.5) releases on north to northeast aspects in the alpine on Monday. Persistent slabs had 90 cm fracture depths with the shallower storm slabs at 40 cm.
Snowpack Summary
Last week's storms brought 60 to 100 cm of new snow to the region. The snowfall was initially accompanied by strong south winds and then followed by strong north winds, so a mix of old/stubborn and newer, more reactive wind slabs can now be found on a range of aspects at higher elevations. In sheltered areas, this storm snow has been gradually settling into a slab above a persistent weak layer buried in mid-March that consists of crusts at low elevations and on south aspects, and surface hoar on shaded aspects at higher elevations. The structure of storm snow above this layer isn't uniform, however, and recent storm slabs have been observed running on an interface down about 40 cm as well as at the late-March crust. Other persistent weak layers from early January and mid-December are still being reported by local operators, but are generally considered dormant.
ghelgeson,
Avalanche Canada
