Another bright sunny day in the Rockies! As you get out there to enjoy this fantastic weather, be ready to step off steep south aspects showing signs of solar warming and continue to avoid shallow rocky or wind affected start zones.
Wind transport continues to build wind slabs and cornices in the alpine. Fresh deposits will be most reactive to human triggers. Below 2100 m, wind slabs up to 80 cm thick sit on a thick crust which could serve as an excellent bed surface. Keep in mind that if triggered, wind slab avalanches can serve as triggers for deeper layers.
Thursday night: Clear. Strong west wind. Freezing level valley bottom.
Friday: Sunny. Strong west wind. Freezing level 1500 m.
Saturday: Mostly sunny. West wind easing through the day to light. Freezing level 1500 m.
Sunday: Mix of sun and cloud. Light northwest to southwest wind. Freezing level 1300 m.
Wednesday saw some minor loose wet activity originating from rock bands on steep solar slopes.
Natural size 2 persistent slab avalanches on the February rain crust were observed Monday and Tuesday. One was a case of a wind slab stepping down in a fan.
There have been no reports of deep persistent slab activity on the basal weak layers for over a week. The most recent is described in this MIN report from February 11 and this MIN on February 9th.
A sun crust may be found on steep solar aspects. Alpine and exposed treeline areas have seen extensive wind effect, involving multiple layers of wind slab. Soft snow can still be found in sheltered areas.
A thick rain crust from early February sits 20-70 cm below the surface up to 2100 m. Recent avalanche activity has been observed at the faceting interface between this crust and overlying snow.
A well consolidated mid-pack overlies generally weak basal facets that may be possible to trigger in isolated shallow rocky start zones or with large loads.
