Our goal today was to assess the size and distribution of the wind slab problem at middle elevations. Over the last 24 hours, the forecast area received about 2–3 inches of new snow yesterday, with another 1–2 inches possible today, accompanied by strong westerly winds (60–80 mph yesterday, easing to roughly 40–50 mph today). With that goal in mind, we focused our travel on terrain where wind transport was most likely to build new slabs while remaining conservative in poor visibility.
At Hermit Lake, we found new drifted snow in sheltered areas ranging from roughly 6 inches to over a foot. This snow was loose and unconsolidated, with limited slab character. As we ascended, protected areas continued to hold soft snow with little evidence of cohesive slab development or propagation, while more exposed terrain showed increasing scouring with elevation.
In and around Tuckerman Ravine, we observed shallow wind slabs up to about 10 inches thick in wind loaded and cross loaded features, along with icy bed surfaces on wind exposed terrain. Hand shears indicated good bonding to the underlying bed surface, with early signs of consolidation within the new snow. Where failures occurred, they were within the new snow near the surface rather than at the interface with the bed surface. The snowpack we traveled on was right-side-up but generally shallow, and we did not encounter drifts deep enough to warrant deeper investigations. We were unable to travel higher into the gullies due to conditions; thicker slabs may exist there based on typical loading patterns, we did not directly observe them.
Visibility was limited by summit fog, temperatures dropped during our time out, and snowfall increased as we exited. With west winds in the 40–50 mph range above treeline, active snow transport was difficult to assess due to visibility challenges, but overall we observed limited snow moving through the air. However, we could not confidently determine how much transportable snow remains available for tonight as winds increase.
Overall, the findings of new shallow wind slabs supported today’s moderate avalanche hazard rating at middle elevations.