We have a lot of uncertainty about the sensitivity and distribution of the current windslab problem. Observations from the high alpine are limited, but given our observations of drifting snow at ridge crests, we're concerned about windslab formation.
Sunday was windy and we observed much wind effect across the snowpack on open slopes at treeline and especially in the high alpine. These slabs will be quite sensitive initially before they begin to bond.
Buried crust/facet layers exist in the upper snowpack on solar aspects. Recent tests show moderate sudden planar results. Exercise caution in areas where these crusts exist, there is uncertainty about how they will react. North aspects are better.
A weak ridge over the area gives clearing skies overnight Sunday, but on Monday we switch to a SW flow (storm track) and clouds move into the area. No precipitation is expected and light winds; a similar day as was Sunday. Tuesday expect a RAPID warm-up and strong SW winds with FL's exceeding 2000m for Wednesday and snow/rain on the way.
20-50 cm of storm snow is forming fresh wind slabs in alpine and some open treeline terrain with mod-strong SW winds. On solar aspects three different buried sun-crusts down 30-70 cm are producing moderate results in tests and remain a significant concern.
No new activity reported Sunday. Explosive control in Kootenay Park on Thursday produced unexpectedly large avalanches at low elevations. On Sunday, Bourgeau-Left waterfall (next to Sunshine gondola) released a large natural avalanche that ran over the waterfall and hit Healy Creek. This may have been triggered by a cornice or strong solar effect.
