Avalanche Forecast

On Wednesday, most reports came in as dry loose avalanches and sluffing up to size 1. Some areas in the Monashees did see more reactivity in the recent storm snow up to size 1.5. These were easily rider triggered and failed naturally. I suspect avalanche activity will increase on Friday with steady moderate to strong winds and slightly warmer temperatures.

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.

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 defence 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.

20-50 cm of recent storm snow accompanied by 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.

Deeper in the snowpack two layers of surface hoar which formed in early January are 60 to 100 cm deep. These weak layers continue to be suspect and on the radar, 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.

Thursday Night

Cloudy with isolated flurries 5 cm. Ridgetop wind 35 - 45 km/h from the southwest. Treeline temperature -6 °C.

Friday

Cloudy with possible sunny breaks and light snow accumulation 5 to 10 cm. Ridgetop wind 20 - 60 km/h from the southwest and treeline temperature rising to -4 °C. Freezing level 1300 m.

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

More details can be found in the Mountain Weather Forecast.

• Avoid all avalanche terrain during periods of strong wind.
• Storm slab size and sensitivity to triggering will likely increase through the day.
• Remain vigilant for changing conditions.
• 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.