Avalanche Canada shorton, Avalanche Canada

Purcells Avalanche Forecast

Jan 15th, 2020 5:00PM

New wind slabs will form at higher elevations on Thursday, requiring careful route finding.

Summary

Confidence

High -

Weather Forecast

WEDNESDAY NIGHT: Cloudy with scattered flurries and up to 5 cm of new snow, strong wind from the south, alpine temperatures drop to -20 C.

THURSDAY: 5-20 cm of low density snow, moderate to strong wind from the south, alpine high temperatures around -10 C.

FRIDAY: Light flurries in the morning then partly cloudy in the afternoon, light wind from the west, alpine high temperatures around -10 C.

SATURDAY: Cloudy with light flurries, light wind from the southwest, alpine high temperatures around -10 C.

Avalanche Summary

Incoming weather will refresh the wind slab problem creating fresh slabs on north and east lee features. Large (size 2-3) deep persistent slab avalanches were triggered naturally and with explosives in steep alpine terrain on Monday and Tuesday. It has been over one week since any persistent slab avalanches on the December surface hoar layer have been reported, although there could still be lingering concerns about triggering that layer on isolated slopes in steep treeline clearings.

Snowpack Summary

Surface conditions are variable due to cold temperatures and shifting wind directions over the past few days. Expect fresh wind slabs to form on lee features on Thursday. A layer of surface hoar that formed in late December appears to be less reactive than it was a week ago and can be found 70 cm deep around Golden, 30 cm deep around Invermere, 70 cm deep around Kimberley, and 100 cm deep along Kootenay Lake. As usual for the Purcells, the base of the snowpack contains basal facets and it remains possible to trigger these deep weak layers in shallow rocky start zones.

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.

Valid until: Jan 16th, 2020 5:00PM