Strong winds will build deeper slabs where dry snow exists, carefully assess the bond to the crust below.
Make conservative terrain choices and avoid overhead hazard.
New storm slabs continue to build at high elevations, especially on north and east aspects.
We are uncertain if storm slabs could still step down to deeper layers, resulting in large avalanches.
We do not have any reports of recent avalanches but suspect a natural cycle occured with rain and warm temperatures.
Last weekend, numerous large (up to size 3) avalanches were reported, both natural and human triggered, all suspected to have failed on the late January crust/facet layer. They were mostly at treeline, although two human triggered avalanches were in open, alpine or alpine-like terrain.
Up to 60 cm of moist snow has fallen in the alpine, rapidly tapering with elevation. This new snow, combined with continued strong west winds, makes for deeper and more reactive slabs in leeward and cross-loaded terrain.
Rain has saturated snowpack at treeline and below, turning the snow isothermal.
The new and settling snow overlies a melt-freeze crust on solar aspects and lower elevations, and wind-affected surfaces at higher elevations.
50-150 cm below the snow surface on north aspects, two persistent weak layers can be found, buried in late January and early February. These weak, sugary facets (over a crust on the late January layer), have the potential to produce large, destructive avalanches.
Saturday Night
Cloudy. 15 to 40 mm of precipitation as snow or rain at treeline. 70 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1600 m.
Sunday
Mostly cloudy. 1 to 3 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1400 m.
Monday
Mostly cloudy. 15 to 25 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -9 °C.
Tuesday
Mostly cloudy. 15 to 20 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -10 °C.
More details can be found in the Mountain Weather Forecast.
