Avalanche Forecast

Recent observations have shown a trend away from the very large persistent slab and deep persistent slab avalanches and toward surface instabilities such as wind slabs. We expect this trend to continue, however, the basal snowpack remains questionable and should still figure into terrain selection around steep features with shallow or variable snowpack areas where these layers may be more easily triggered by a person or machine as well as large wind slab or cornice releases.

Roughly 10 to 15 cm of new snow, coupled with winds shifting to the northwest may build new wind slabs on south and east-facing terrain from reverse loading. These new wind slabs will be developing over variable surfaces of soft snow in sheltered terrain and old wind slabs in open terrain features.

Several strengthening crust/facet/surface hoar layers can still be found in the upper and middle portions of the snowpack. The most concerning persistent weak layer, however, is at the base of the snowpack and composed of large and weak facets formed in November. This layer is strengthening slowly as well, remaining most likely to be triggered in thin, rocky alpine and upper treeline terrain.

Monday night

Cloudy with scattered flurries bringing another 5-10 cm of new snow. Northwest winds 20 to 30 km/h. Treeline temperatures -11°C.

Tuesday

Cloudy, clearing in the afternoon, 15 to 20 km/h northwest winds switching to the southwest and increasing throughout the day. Treeline temperatures -12 °C

Wednesday

Increasing cloud with isolated flurries, 20 to 30 km/h southwest winds, treeline temperatures -8 °C.

Thursday

Cloudy with 5 to 7 cm of new snow, 10 to 20 km/h southwest winds, treeline temperatures -5 °C.

More details can be found in the Mountain Weather Forecast.

• Use increased caution at all elevations. Storm snow is forming touchy slabs.
• Use careful route-finding and stick to moderate slope angles with low consequences.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.