Unexpectedly deep new snow accumulations are maintaining elevated danger in the region. Wind affected areas are especially touchy. Stick to conservative terrain on Sunday.
Summary
Confidence
High -
Weather Forecast
Sunday: Mainly cloudy. Light southeast winds. Alpine temperatures of -12.Monday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate south winds. Alpine temperatures of -13.Tuesday: Mainly cloudy with scattered flurries and up to 5 cm of new snow. Moderate to strong south winds. Alpine temperatures of -14.
Avalanche Summary
An early report from avalanche control that tool place in the north of the region on Saturday details a Size 3 wind slab successfully triggered with explosives. The impressive size of this result serves as a good example of the extent of recent wind loading. Reports from Friday include observations of several storm slab avalanches from Size 1.5-2. Two of these released naturally from steep, south-facing alpine terrain. Ski cutting also yielded a few Size 1 wind slab releases from ridgetop lee terrain at treeline and above.A number of persistent slab avalanches were reported last week and it should be noted that very real potential currently exists for a storm slab avalanche to 'step down' to one of several deeply buried weak layers. This would likely result in a very large and destructive avalanche.Looking forward, expect a decline in natural avalanche activity while the potential for human triggering at the depth of our recent snow persists a few more days.
Snowpack Summary
Stormy weather since Tuesday night has delivered a wide ranging 25-70 cm of new snow to the region, with the bulk of the new snow arriving over Friday night and blanketing localized pockets with up to 40 cm of new snow. The new snow has buried widely reported faceted surface snow as well as surface hoar reported at about 3mm on shaded aspects before the storm. Moderate to strong southerly winds have accompanied the new snow, promoting the formation of touchy wind slabs in lee areas at upper elevations. Now a highly variable 40-100 cm below the surface you'll likely find the mid-February interface which is composed of a thick rain crust up to about 2000 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. Several deeper weak layers remain a concern including the February 3rd surface hoar layer (50-130 cm deep), and the mid-January surface hoar layer in the northern Purcells (about 130 cm deep). Basal facets may still be reactive in shallow, rocky start zones.
cgarritty,
Avalanche Canada
