Lingering slabs and cornices will become weak with sun exposure. Extra caution is required on sun exposed slopes during the heat of the afternoon.
Summary
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
Light scattered flurries are expected for Sunday morning with sunny breaks in the afternoon. Freezing levels are forecast to be around 1000m and alpine winds are forecast to be moderate from the south. A mix of sun and cloud is expected for Monday the possibility of scattered flurries. Afternoon freezing levels are expected to be around 1000m and alpine winds are forecast to be light from the south. Light snowfall is currently forecast for Tuesday with freezing level around 1000m and moderate alpine wind from the southwest.
Avalanche Summary
On Friday, a natural cornice release in the south of the region triggered a size 2 storm slab on a north aspect at 1400m elevation with a slab thickness of 15cm. North of Stewart, a snowcat triggered two size 2 wind slabs on a northeast aspect at 1275-1375m elevation. East of Terrace, skiers were triggering size 1 slabs up to 15cm thick. On Thursday, a natural size 3.5 persistent slab avalanche was reported in Bear Pass. The occurred on a northwest aspect at 1350m elevation and released on the late-February surface hoar layer. A natural size 2.5 storm slab was reported from the same area and appears to be on a northern aspect. A skier triggered a size 2 cornice in the same area which did not trigger a slab on the slope below. In the south, a natural cornice release triggered a size 2 persistent slab on a north aspect at 1700m which released down 80cm on a layer of surface hoar. Lingering wind slabs may still be reactive to human triggering on Sunday. There is extra concern for the deep surface hoar layer that seems to be most reactive north of Stewart but may also exist in the south. This likely would require a heavy trigger like a cornice or smaller avalanche stepping down.
Snowpack Summary
Ongoing light snowfall and strong winds have shifted the new snow into hard or soft wind slabs at treeline and in the alpine, maintaining a wind slab problem on northerly aspects and scouring leeward slopes. A breakable crust is being reported on the snow surface below treeline on Friday. Areas north of Stewart are reporting a weak surface hoar layer down 70-100cm which sits below the last week of accumulated storm snow. In the south of the region, an old crust/facet layer buried in early February can now be found around 80-120 cm below the surface but this layer has been dormant recently.
rbuhler,
Avalanche Canada
