Avalanche Forecast

Moderate - Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.

SATURDAY NIGHT: Increasing cloudiness, light to moderate south wind, alpine temperature -13 C, freezing level below valley bottom.

SUNDAY: 5-15 cm. snow, moderate south wind, alpine temperature -7 C, freezing level 500 m

MONDAY: Cloudy with possible flurries; 0-3 cm, light southwest wind, alpine temperature -5 C, freezing level 700 m

TUESDAY: Mix of sun and cloud, light southwest wind, alpine temperature -6 C, freezing level 500 m.

Numerous large cornice falls have been reported over the last few days. Many of them have not triggered slabs on the slopes below, but a few have, resulting in very large (size 3) avalanches. A cornice triggered size 3 deep persistent slab avalanche was reported on a steep convexity at treeline on Tuesday. This suggests large avalanches are still possible with large triggers in isolated locations. 

5-15 cm of new snow has buried a widespread layer of surface hoar (size 5-15 mm.). This layer exists on all aspects and elevations except for steep solar aspects where it was melted by sun and windward alpine slopes where the layer was flattened by wind before being buried. Surface hoar sitting on a thin sun crust may exist on lower angle solar aspects which is a particularly nasty combination. The new snow will likely become increasingly reactive as it settles into a cohesive slab. The mid and lower snowpack is generally well settled and strong.

• Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
• Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.
• Be alert to conditions that change with elevation and wind exposure.
• Cornice failure may trigger large avalanches.