Avalanche Forecast

Issued: Jan 6th, 2023 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is moderate. Known problems include Persistent Slabs and Wind Slabs.

zryan, Avalanche Canada

West Island.

Heavy snowfall and extreme wind are creating very dangerous avalanche conditions at treeline and alpine elevations.

A persistent slab problem lurks at a prime depth for human triggering as well as large, consequential avalanches. Only the most simple non-avalanche terrain free of overhead hazard is appropriate at this time.

Summary

Confidence

Moderate

Avalanche Summary

No significant avalanche activity has been reported this week.

On Friday and looking forward to Saturday, we expect natural avalanches to occur during periods of intense precipitation and wind-loading.

Snowpack Summary

Heavy snowfall accumulation has occurred above 1000 m in the past few days. Rain will soak the snowpack at lower elevations. Avalanches during this period could run on a crust layer that is now buried 60 to 100 cm deep. Snowpack depths at treeline are roughly 100 cm, while most below treeline terrain is below the threshold depth for avalanches, except for isolated smooth features.

Weather Summary

Friday night

Cloudy with precipitation, 30-50 mm. Snowline 600 to 900 m. Southerly winds 60-120 km/h at ridgetop, treeline temperatures around 0 C.

Saturday

Precipitation easing, 10-20 mm mainly in the morning. Snowline around 700m. Southerly winds 40-60 km/h at ridgetop easing into the afternoon, treeline temperatures rise to 1 C.

Sunday

Cloudy with precipitation, 10-20 mm. , snowline around 700 m. Southerly winds increase 60-100 km/h at ridgetop. Treeline temperatures around 0 C.

Monday

Cloudy with precipitation, up to 4mm. Snowline around 600 m. 60-90 km/h southeasterly winds at ridgetop. Treeline temperatures are around -1 C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Keep in mind the crust offers an excellent bed surface for avalanches.

Problems

Persistent Slabs

A crust formed in early January is bonding poorly to the overlying snow. With the recent new snow load, this crust is now buried 60-100 cm deep, a prime depth for human-triggering as well as large, consequential avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Wind Slabs

Strong southerly winds and heavy snowfall have created deep deposits of wind slab in the alpine and treeline.

Aspects: North, North East, East, South East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Jan 7th, 2023 4:00PM