Avalanche Forecast

Moderate - Uncertainty is due to extremely variable snowpack conditions reported through the region.

Thursday night: Cloudy, convective flurries with up to 5 cm of snow, strong southwest winds decreasing to moderate, alpine temperature -10 C, freezing level dropping to valley bottom.

Friday: Mix of sun and cloud, isolated flurries with trace accumulations, light southwest winds, alpine high temperature -6 C, freezing level 600 m.

Saturday: Mostly cloudy, isolated flurries with trace accumulations, light variable winds, alpine high temperature -7 C, freezing level at valley bottom.

Sunday: Mix of sun and cloud, isolated flurries with trace accumulations, light southwest winds, alpine high temperature -7 C, freezing level at valley bottom.

Over the past several days, there has been a natural cycle of large to very large (size 2-3) avalanches releasing in the recent storm snow, primarily on northeast, east, and southeast aspects above 1800 m. Several were triggered by large cornices failures. 

Over the past week, there have been many reports of persistent slab avalanches releasing on the Feb 22 surface hoar. These avalanches primarily occurred on north, northeast, and east aspects between 1400-2100 m. Check out this MIN for a helpful illustration of where you might expect to find this problem. 

Incremental snowfall and strong winds continue to build wind slabs in the alpine and open areas at treeline. A few sun crusts exist on solar aspects in the upper snowpack. Convective snowfall in the wake of the storm may obscure the evidence of these wind slabs.

A weak layer of surface hoar may be found 60-100 cm deep. There is uncertainty about the distribution and reactivity of this layer, especially in the north of the region. Sheltered slopes near and below treeline are most suspect. Read more about surface hoar on our forecaster blog! 

Below a melt-freeze crust down 80-120 cm from early February, the snowpack is well settled and strong.

• Avoid freshly wind loaded terrain features.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Use conservative route selection and resist venturing out into complex terrain.
• Even brief periods of direct sun could produce natural avalanches.