The layer of faceted snow near the base of our snowpack is concerning. While we haven’t had a blockbuster storm recently, the snowpack feels the weight of the snow and wind that’s built slabs above since 12/17. The warm temperatures and strong winds have created dense, hard slabs that feel deceptively solid underfoot. The ‘bridging’ effect can lure you into steep terrain, only to fail when you hit a thinner or softer spot in the slab, collapsing the weak layer and releasing the thicker, harder slab above you.

Assessing sensitivity today is difficult. You might get clear warning signs like audible collapses, ‘whumphs’, or shooting cracks, which are undeniable signs of instability. However, the stiff slab may also shield the weak layer from collapsing and mask the danger.

We have limited observations from the backcountry, possibly due to the low snow coverage and challenging backcountry conditions. What we do know is that signs of instability are present: recent avalanches, collapsing, unstable test results, strong wind, warm temperatures, and dense snow are obvious signs that dangerous and tricky avalanche conditions are present. See forecaster Greg Gagne's snow pit from Murdock Peak last Monday: the column peels out during isolation!

Soft and hard slabs of wind blown snow continue to build on leeward slopes. These new drifts may be sensitive in steep terrain. Be mindful that small, isolated slabs may also form on southerly slopes; these drifts may not bond well to the underlying surfaces in steep terrain.

Nearly a week of strong southerly wind scoured available soft snow and redistributed it onto mid and upper elevations, incrementally adding weight to the faceted weak layer near the ground. Any surface wind slab triggered on slopes above 9,000 feet facing West, North, or East has the potential to "step down," resulting in a deeper and wider avalanche breaking on the buried persistent weak layer.

Overnight freezing temperatures rose to nearly 11,000 feet. Rain on snow is severely weakening the snowpack and creating unsupportable conditions. In these conditions, you may be able to trigger wet loose avalanches that gouge down to the ground, or wet slabs that fail on a moist faceted layer near the base of the snowpack. There is a lot of uncertainty with this issue; please exercise caution.

Special Note for mountain communities: For residents in upper mountain communities where snow remains on roofs, warm temperatures and rain create a significant danger. Be aware that large amounts of heavy snow can slide off roofs unexpectedly.