Prolonged warming will keep persistent slabs at their tipping point. Manage this high-consequence snowpack with low-consequence terrain.
Weak layers from January and February persist within the upper 100 cm of snow. These layers are expected to remain reactive, especially with the added stress of strong sun and warm temperatures.
Wet loose avalanches will become more likely as daytime warming and sun melt the upper snowpack. These avalanches may step down to persistent weak layers.
Over the last few days, numerous natural, explosive and human-triggered avalanches (up to size 4) were reported across various elevations and aspects. Many of these avalanches failed on the late January persistent weak layer.
Strong evidence indicates that persistent weak layers remain primed for human triggering.
Read more in our Forecasters' Blog.
A melt-freeze crust or moist snow likely makes up the surface on all but high-elevation north aspects. High overnight freezing levels mean crust recovery may be weak. This tops 30 to 50 cm of recent storm snow generally rests on a weak layer of facets, surface hoar, or a crust. Another persistent weak layer, buried in late January, lies 50 to 100 cm deep across the region. This layer also consists of surface hoar/facets or a crust, depending on aspect. The remaining snowpack is well-settled and strong.
Saturday Night
Mostly clear. 5 to 20 km/h southwest ridgetop wind. Treeline temperature -1 °C. with an alpine temperature inversion. Freezing level 2500 m.
Sunday
Increasing high cloud. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -2 °C with an alpine temperature inversion. Freezing level 2000 m.
Monday
Mostly cloudy with up to 5 cm of new snow. 5 to 15 hm/h north ridgetop wind. Treeline temperature -3 °C. Freezing level rising to 1500 m.
Tuesday
A mix of sun and cloud. 10 to 30 hm/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level rising to 1500 m.
More details can be found in the Mountain Weather Forecast.
