Crust recovery is a bit uncertain for Saturday, but it's mainly a travel conditions concern. Lingering cornices are the main hazard to avoid--they're an effective avalanche trigger.
Large cornices still loom over many ridgelines and they won't hang on forever. Be aware of overhead hazards and stay back from cornices on ridges.
This region is the most likely in the Southwest for a cornice fall to trigger a surprise slab.
Activity in the region has been on a downward trend, with cornices accounting for most of the interesting recent observations.
A cornice fall above Armchair Glacier was seen Wednesday, suspected to have failed 12 - 24 hours earlier. It triggered a slab on the slope below (adding up to size 3), likely on one of the persistent layers mentioned in our snowpack summary. A second size 2 cornice fall on a NE aspect at about 2500 m was observed by another group in the Duffey corridor.
Sustained high freezing levels with a bit of insulating cloud cover may work against crust recovery on Saturday, possibly keeping or moving the snowpack below 2000 m closer to an isothermal state. Up to about 10 cm of windblown dry snow may still be hiding on north-facing slopes above 2000 m. It overlies old wind-affected snow above this elevation and a firm crust below.
Two older crusts exist 1-1.5 m deep at treeline and above. Concern for these layers is limited to high north aspects where large cornice fall may have enough force to trigger a slab, like what was observed on Armchair Glacier Wednesday. The snowpack below these layers is well settled.
Friday Night
Mostly clear skies. 20 km/h southwest ridgetop wind, easing. Treeline temperature 4 °C. Freezing level 2600 m.
Saturday
A mix of sun and cloud with isolated showers, less than 1 mm. 10 km/h southwest ridgetop wind. Treeline temperature around 4 °C. Freezing level falling from 2600 m to 2400 m.
Sunday
Mostly cloudy with scattered showers, 1 to 3 mm, after 5 mm overnight. 10 to 15 km/h variable ridgetop wind. Treeline high temperature 4 °C. Freezing level to 2400 m.
Monday
Mostly cloudy with scattered showers, 1 mm, with a possible trace of alpine snow. 20 to 40 km/h southwest ridgetop wind, increasing. Treeline high temperature 1 °C. Freezing level to 2100 m.
More details can be found in the Mountain Weather Forecast.
