Avalanche Forecast

Good

A very benign weather pattern will bring little precipitation, convective cloud, light winds and sunny periods over the next few days. Saturday: Scattered convective cloud cover. Light flurries, with no significant accumulations. Ridgetop winds light from the NW. Alpine temperatures near -1. Freezing levels 1700m falling to valley bottom at night. Sunday/Monday: A dominating ridge with diurnal temperature swings and freezing levels rising to 2000 m during the day. Continued sunny skies, and light ridgetop winds. The ridge will weaken on Monday allowing bands of cloud, and light precipitation.

Observations from the past few days are limited. On Thursday a natural cornice release size 2.5 was reported. This did not pull out a slab on the slope below. On Wednesday reports include one natural cornice triggered Size 2.5, 100cm thick wind slab avalanche on a north aspect. A couple days ago, a size 3 glide slab avalanche was also observed on a south aspect at 1800m. I suspect natural activity will occur throughout the weekend with warming temperatures, and sunny skies. Make observations continually as you travel. Pinwheeling, snowballing, loose sluffing, and avalanches are all indicators of the snowpack deteriorating. I would avoid slopes where these actions are occurring.

Over the past week up to 60 cm of recent storm snow has fallen. Sustained southeasterly through northeasterly winds are contributing to continued wind slab formation as well as cornice development at upper elevations. Although generally settling and bonding well, recent snowpack tests on a north facing treeline slope resulted in easy to moderate shears down 25cm within the storm snow, and down 65cm on an underlying crust that formed near the end of March. Not only will daytime warming and sun-exposure cause surface snow to lose cohesion and cornices to weaken, they will also increase settlement rates and decrease slab stability.