Sunday will continue to be warm and spring-like. The snowpack is already stressed by rising temperatures, recent wind loading, and solar input. Be patient for temperatures to cool off.
Avoid sun-exposed slopes, watch for overhead hazards, and make conservative choices.
Recently redistributed snow from last week is sitting on top of a layer of weak facets from the February drought, which rests on old wind slabs, crusts, or depth hoar. With rising temperatures, human triggering of this layer remains likely.
With freezing levels creeping to at least 2200 m over the weekend and sunny skies in the forecast, loose wet avalanches should be on your radar. Steep slopes with direct sun are of most concern. Watch what is above you as loose rock and failing cornices can work as natural triggers.
The local ski hill reported recent activity on this layer in the surrounding backcountry. The large depth hoar at the bottom of the snowpack is inherently weak. The rising temperatures, solar input and recent wind loading has the potential to wake up this problem.
Today’s warmer weather brought more avalanche activity. Highway 93N patrol observed several size 2-2.5 persistent slabs, triggered by cornice failures or smaller loose avalanches, proving how smaller loads can activate this weak layer. Our neighbours are still reporting natural size 2-3 persistent slab activity.
Continued warmth and potential rain or snow ahead will further destabilize the snowpack. Avalanche conditions remain serious, even if not obvious.
Freezing levels rose to just below 3000m Saturday, creating moist surface snow. Expect crust formation, especially on solar aspects, with the overnight refreeze.
Moderate to strong winds have redistributed last week’s snow, which continues to load leeward features while stripping alpine and exposed treeline areas.
The top 10-30cm sits over weak February facets atop old wind slabs, crusts, or depth hoar. Below 1600m, warmth has saturated the weak snowpack.
Expect to still see spring-like weather on Sunday with lots of sun and freezing levels rising above 2200m. The SW winds continue within the 20-40 km/h range at ridgetop.
We will begin to see a small dip in temperatures with the potential for a little more snow or rain in the forecast Sunday evening into Monday daytime.
