Purcells

Not much change expected until Sunday when new snow and wind arrive.  Watch for wind slabs and cornices at upper elevations. And avoid shallow, rocky areas where triggering a deeper layer may still be possible.

Moderate - Forecast snowfall amounts are uncertain

FRIDAY: Mostly cloudy, light flurries. Accumulation trace. Ridge wind light, southwest. Temperature -12. Freezing level valley bottom.SATURDAY: Mix of sun and cloud, light flurries. Accumulation trace. Ridge wind light, west. Temperature -8. Freezing level valley bottom.SUNDAY: Flurries. Accumulation 5-10 cm. Ridge wind moderate to strong, west. Temperature -7. Freezing level 600 m.

On Wednesday there were reports of several skier triggered slab avalanches up to size 2 (30-40 cm deep) on predominantly steep, south-facing features failing on the most recently buried crust/surface hoar interface.Tuesday there were reports of a skier triggered size 2-2.5 cornice failure that produced very large, bus-sized cornice chunks on an north aspect at 2400m. As well as a size 1.5 natural wind slab failure (50-70 cm deep) on a west aspect at 2050 m.On Monday we received reports of a cornice triggered size 2.5 slab avalanche on a high north east alpine face near 2900m. We also received reports of natural wind slabs to size 2.5 (most crowns 20-40cm thick) on a wide range of aspects above 1900m elevation. On Sunday, several natural wind slab avalanches to size 2 were reported on primarily east aspects between 2200m and 2600m. Although deeper, persistent avalanche activity has become less frequent over the past week, light triggers in shallow rocky areas, as well as large triggers such as a cornice collapse or step down from a wind slab release, still have the potential to result in large destructive avalanches.

Recent storm snow totals are 15-30 cm with more in the very south of the region near Kimberley, where totals are closer to 50 cm. Moderate south west through north west winds have redistributed these accumulations into deeper, reactive slabs in wind-exposed terrain. The recent snow sits on the old interface that was buried mid-February consisting of; a mix of older wind slabs in exposed higher elevation terrain, a sun crust on steep solar aspects, and surface hoar on sheltered slopes.Below the snow surface several persistent weak layers make up a complex snowpack which is slowly beginning to show sign of improving but still remains suspect. In the top 80-120 cm of the snowpack, two surface hoar/ crust layers buried in January can be found. Expect to find one or other of these on all aspects and elevations.Deeper in the snowpack (around 150 cm deep) is a facet/crust/surface hoar layer from December, most prevalent at and below tree line.Near the base of the snowpack is a crust/facet combo, most likely to be triggered from thin spots in the alpine.