Avalanche Forecast

On Tuesday, several rider-triggered storm slab and wind slab avalanches were seen up to size 1, and numerous loose dry avalanches size 1-2 were reported from steeper terrain features.

On Monday, numerous wind slab and storm slab avalanches were reported up to size 3. These occurred on all aspects at treeline and alpine elevations.

Last weekend, various deep persistent slab avalanches were also triggered naturally, being large to very large (size 2 to 4). The avalanches occurred on all aspects between 2400 and 2800 m.

High-consequence avalanche activity is ongoing for several weeks now. Most of the avalanches over the past week were released between 1800 and 2800 m, on all aspects.

Your best defense is to stay diligent in choosing low-consequence terrain away from overhead exposure. See more on the potential of triggering deeper weak layers Forecasters' Blog.

20-45 cm of recent storm snow accompanied by light to moderate westerly wind will build reactive storm slabs and wind slabs in lee terrain features. The new snow sits above a plethora of old snow surfaces including previously wind-affected snow at upper elevations, a sun crust on steep solar aspects, faceted snow, and surface hoar crystals in wind-sheltered terrain.

Below the recent snow is a melt-freeze near 1800 m which exists in the northern part of the region and up to 2000 m further south. This is buried about 30 to 60 cm deep and may host small facets on the crust.

Two layers of surface hoar which formed in early January are 50 to 100 cm deep. These weak layers continue to be reactive to human triggering, although snowpack tests are starting to indicate they may be slowly strengthening.

Large and weak facets from November are near the base of the snowpack, which continue to produce very large avalanches in the region, as described in the Avalanche Summary.

Wednesday Night

Cloudy with snowfall, accumulation 10 cm with local enhancements possible. Ridgetop wind 25-40 km/h from the southwest. Treeline temperature -7 °C.

Thursday

Cloudy with light snow accumulation 5 to 10 cm. Ridgetop wind 35-60 km/h from the southwest and treeline temperature rising to -3 °C. Freezing level 1100 m.

Cloudy with possible sunny breaks and new snow accumulation 5 to 10 cm. Ridgetop wind 30-50 km/h from the southwest and treeline temperature -3 °C. Freezing level 1400 m.

Possible sunny periods and isolated flurries 5 to 10 cm. Ridgetop wind 20 to 45 km/hr from the southwest. treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

• Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
• Storm slab size and sensitivity to triggering will likely increase through the day.
• Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
• Be mindful that deep instabilities are still present and have produced recent large avalanches.
• Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.