Recent widespread & large avalanche activity indicates an unstable snowpack.
Continue to make conservative terrain choices as remote-triggering remains a serious concern.
Southwesterly winds built wind slabs on leeward northerly and easterly slopes. If triggered, wind slab avalanches may step down to deeper layers resulting in larger avalanches.
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 warming temperatures.
Wet loose avalanches will become more likely as daytime warming and sun melt the upper snowpack. There is also concern that they 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. Some involved only storm snow, while others failed up to 100 cm deep on the late January persistent weak layer. At treeline and below, some avalanches became wet, entraining significant debris.
Strong evidence indicates storm slabs and persistent weak layers remain primed for human triggering.
A recent storm deposited 30 to 50 cm of snow across the region and southwesterly winds formed reactive slabs on leeward slopes. At lower elevations and on sun-exposed slopes, warm temperatures and solar radiation resulted in a crust or moist snow. In wind-sheltered areas, the storm snow generally rests on a weak layer of facets or surface hoar, while elsewhere it overlies a widespread crust. Another persisent 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.
Thursday Night
Mostly cloudy with 0 to 3 cm of snow. 15 to 30 km/h west ridgetop wind. Treeline temperature 0 °C.
Friday
A mix of sun and cloud. 10 to 15 km/h southwest ridgetop wind. Treeline temperature +2 °C. Freezing level around 2100 m.
Saturday
Sunny. 25 km/h south ridgetop wind. Treeline temperature +3 °C. Treeline temperature 3 °C. Freezing level falling to valley bottom overnight, then rising to 2600 m.
Sunday
Mostly sunny. 10 to 20 km/h variable ridgetop wind. Treeline temperature +1 °C. Freezing level falling to valley bottom overnight, then rising to 2000 m.
More details can be found in the Mountain Weather Forecast.
