Solar input and 0 °C alpine temperatures may trigger a natural avalanche cycle on solar slopes.
Minimize exposure to overhead hazards when solar radiation is strong.
Recent northerly winds have built wind slabs on lee slopes. Previous shifting winds created slabs on a variety of aspects. Individually evaluate wind effect on slopes as you move through the terrain.
Above-freezing temperatures in the alpine and solar input may trigger loose wet avalanches on sunny slopes. A moist or wet snow surface, pinwheeling or natural avalanches are signs of a weakening snowpack.
Throughout the weekend we received numerous reports of natural (up to size 2.5) and rider-triggered (up to size 2) wind slab avalanches. These avalanche reports spanned all aspects at alpine and treeline. As wind dies off natural wind slab avalanche activity will likely decrease but slabs may remain sensitive to human triggering. Evaluate slopes individually for slabs before committing to them.
Expect to find wind-affected surfaces on all aspects of the alpine and on exposed features at treeline. The freshest and most reactive wind slabs are found on southerly aspects. In sheltered areas at treeline and below 20 cm of low-density snow overlies faceted snow or surface hoar in sheltered areas, and wind-affected surfaces in exposed areas.
An otherwise right-side-up snowpack appears to be bonding well to a crust buried 70 to 100 cm deep. The mid and lower snowpack is generally well-settled and bonded with no layers of concern.
SH 1700 m down and facets 1700 m yup.
Monday Night
Mostly clear skies. 20 to 30 km/h northwest ridgetop wind. Treeline temperature 0 °C. An above freezing layer develops between 1700 and 2500 m.
Tuesday
Mostly sunny. 15 to 25 km/h northwest ridgetop wind. Treeline temperature +2 °C. Freezing levels 2500 m.
Wednesday
Mostly sunny. 15 to 25 km/h southwest ridgetop wind. Treeline temperature +1 °C. Freezing levels 2500 m.
Thursday
Partly cloudy with light flurries, 1 to 2 cm. 15 to 25 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing levels drop to the valley bottom.
More details can be found in the Mountain Weather Forecast.
