We did not perform formal stability tests such as ECTs or compression tests. However, hand shear results varied. Around 5,000ft on a S/SE aspect, hand shears were failing on isolation within a density change of the wind slab. In other areas of similar aspect and elevation, hand shears provided no results, with cohesionless snow. Results varied significantly over short distances.
Quick report
We ascended the Winter Lion Head Trail to access the start zones in the south facing gullies of Tuckerman Ravine (Right Gully, Sluice, Lobster Claw, and near the Lip/Headwall). Our goal was to assess wind slab development in the new snow.
Upper elevations (above 5,000’):
- We found small, soft wind slabs high in the terrain.
- Slabs were cohesive and generally 1–2 feet thick.
- Winds had shifted NNW; we still observed light snow transport, and boot tracks were refilling in the short time we were there -wind was continuing to move small amounts of available snow.
Most of the slabs seemed fairly well bonded to the older snow surface below and didn’t show significant reactivity. We did see a few small shooting cracks in isolated pockets that confirmed slab character. In a few locations, hand shear/isolation tests produced failures within the new snow; if this same structure were present in a larger, more connected slab it would be more concerning.
At mid elevations, the new snow was more evenly distributed with less obvious drifting. We also noted solar input affecting the surface snow: from roughly 5,200’ down to about 4,500’, the snow became moist in places and was balling on crampons, an indicator of surface wetting and conditions conducive to some settlement. Overall, the wind slab problem we found was largely confined to the upper elevation start zones.
Weather
- Air Temp
- 12
- Cloud Cover
- scattered
- Wind Loading
- light
- Recent Snowfall
- 15
- Snow Avail For Transport
- moderate amounts
Obscured skies became scattered into the afternoon. Northerly winds remained light throughout the day, and occasional gusts were observed. About 15 cm of recent snowfall provided moderate amounts of snow available for transport, though wind loading remained light overall due to limited wind speeds.