Avalanche Forecast

Issued: Dec 3rd, 2022 4:00PM

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

dsaly, Avalanche Canada

Cariboos, North Rockies, McBride, Premier, Quesnel, Sugarbowl, Kakwa, McGregor, Pine Pass, Renshaw, Robson, Tumbler.

Early season uncertainty and limited field data: dig down and investigate the snowpack in the area you are riding.

Summary

Confidence

Moderate

Avalanche Summary

On Tuesday, explosives near Sukunka creek triggered mostly small (size 1) wind slab avalanches, However one size 2.5 was triggered on a south aspect at 2200 m. The avalanche was described as fast-moving, with the powder debris splitting onto two separate avalanches. Recent windslab avalanches have generally been reported on north aspects at treeline, likely failing on the reported melt-freeze crust.

Reports from an observation flight on Monday over the Sentinel Pass indicate that a past natural storm slab avalanche cycle occurred in steep rocky terrain up to size 2.5 (very large).

Please consider sharing your observations via the Mountain Information Network to help us and fellow recreationists.

Snowpack Summary

40-80 cm of snowfall accumulated last week, and strong southwest winds during the storm quickly impacted fresh snow at upper elevations. Settled snow now covers a melt-freeze crust down 60-80 cm. We're still gaining information on the distribution and sensitivity of this layer, but further south of the Avalanche Forecast region, reactive surface hoar is found over this crust. Snowpack depths range from 60 cm at treeline to 120 cm in the alpine.

Weather Summary

Saturday night

Cold, valley cloud forming overnight. Gusty northeast wind up to 50 km/hr. Treeline temperature low -27 C.

Sunday

Cold, cloudy, and windy. North wind 15-30 km/hr, east slopes of the Rockies could see gusts to 35 km/hr. Treeline high temperature -14 C.

Monday

Increasing cloud and isolated flurries with higher accumulations are forecast for the east slopes of the Rockies, trace to 5 cm accumulation. West wind 15-25 km/hr. Treeline high temperature -12 C.

Tuesday

Gusty wind and flurries, trace to 5 cm. Southwest wind 15-30 km/hr. Treeline temperature rising to -9 C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Recent wind has varied in direction so watch for wind slabs on all aspects.
Make observations and assess conditions continually as you travel.
Investigate the bond of the recent snow before committing to your line.

Problems

Wind Slabs

Southwest winds have impacted snow at upper elevations, incoming north winds may reverse-load features. There's a lot of loose snow out there, expect fresh slabs to form where the wind picks up.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

A weak layer of surface hoar and crust may be found down 40-80 cm. This layer has been very reactive south of Valemont and towards Revelstoke (especially between 1700-2200 m). With few field observations, we don't know the distribution and sensitivity of this layer across this forecast region.

Dig down and investigate the new snow. And keep an eye on the wind, slabs may quickly form wherever the wind encourages the fresh snow to bond; and with a weak layer of surface hoar below, slabs may be more widespread, extend into treeline elevations, and be more reactive than expected in sheltered areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Dec 4th, 2022 4:00PM