Avalanche Forecast

Issued: Dec 4th, 2022 4:00PM

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

dsaly, Avalanche Canada

Shuswap, North Okanagan, South Okanagan.

Pay attention to the wind and investigate the bond of the new snow.

Summary

Confidence

Low

Avalanche Summary

No new avalanches have been observed or reported in this region. However, note that we have had very few field observations.

Snowpack Summary

Up to 30 cm of low-density snow covers older more settled snow. Southwest winds have left wind slabs at upper elevations. Down 40-60 cm is a melt-freeze crust from the middle of November. To the east, in the Columbia and Kootenay-Boundary Forecast regions, a layer of surface hoar (on a crust) down 40-70 cm has been quite reactive with extensive reports of whumpfing and cracking. This layer is found within this forecast region, but we need more field observations to determine its extent and sensitivity. Snowpack depths exceed 100 cm at upper elevations.

Weather Summary

Sunday night

Clear with patchy cloud, possible inversion and valley fog forming. Light northeast wind. Treeline temperature low -16 °C

Monday

Cold with increasing cloud and isolated flurries, trace accumulation. Northwest wind 15-25 km/hr increasing through the day. Treeline high temperatures -12 °C.

Tuesday

Cloudy and cold with isolated flurries, up to 5 cm. West wind 20-40 km/hr. Treeline high temperature -12 °C.

Wednesday

Cloudy and cold with isolated flurries. Southwest wind 20-40 km/hr. Treeline high temperature -8 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
Closely monitor how the new snow is bonding to the old surface.
Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.

Problems

Wind Slabs

Winds are forecast to increase through Monday. There's a lot of loose snow out there, expect fresh slabs to form where the wind picks up.

Reports further east find a weak layer of surface hoar down 40-60 cm (check out the Avalanche Forecast to the east) and have had extensive reports of whumpfing and cracking on this layer. We have limited observations this year, but this problem could be encountered in this Avalanche Forecast region. 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, reactive 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 - 2

Valid until: Dec 5th, 2022 4:00PM