Avalanche Forecast

Issued: Nov 23rd, 2019 3:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada mconlan, Avalanche Canada

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Saturday night's storm will increase the avalanche danger. Conservative decision making will be required to travel safely until the new snow stabilizes. Back off and avoid avalanche terrain if you find more than 30 cm of snow accumulation.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations. Forecast snowfall amounts are uncertain.

Weather Forecast

SATURDAY NIGHT: Cloudy with snowfall, accumulation 20 to 30 cm, strong southwest wind, alpine temperature -3 C, freezing level 1500 m.

SUNDAY: Mix of sun and cloud with isolated flurries, moderate west wind, alpine temperature -7 C, freezing level 1000 m.

MONDAY: Mix of sun and cloud, light northwest wind, alpine temperature -8 C, freezing level 700 m.

TUESDAY: Mix of sun and cloud, light northeast wind, alpine temperature -10 C, freezing level bellow valley bottom.

Avalanche Summary

Observations are very limited right now, with recreationists starting to get into the mountains and operations opening soon. We haven't received any reports of recent avalanche activity. The new snow coming this weekend may not bond well to the underlying snow at higher elevations. The most likely place to trigger a large avalanche would be where the snow surface appears smooth.

If you see anything while out in the field, please consider sharing that information with us and fellow recreationists via the Mountain Information Network (MIN).

Snowpack Summary

Saturday night's storm could drop around 30 cm of snow in the region. The new snow will cover a variety of surfaces, from bare ground below treeline, around 50 cm of snow intermixed with trees and rocks at treeline and lower alpine elevations, and upwards of 100 cm of snow above 2000 m.

The new snow may not bond well to an underlying hard melt-freeze crust. Use particular caution where the snow surface appears smooth, as this may mean an avalanche could propagate over a wider area.

Another terrain characteristic to be thinking about during early-season conditions is ground roughness. Areas with a large variation in ground roughness (for example big boulders, logs, trees) will mean the snow is discontinuous and make it difficult to trigger avalanches, but also more difficult to recreate in. Areas with smooth ground (for example glaciers, scree or grass slopes, rock slabs) may be better for recreating on, but the smooth ground is where the possibility of triggering a large avalanche is the most likely.

Problems

Storm Slabs

An icon showing Storm Slabs

Around 20 to 30 cm of new snow falling with strong southwest wind may not bond well to underlying surfaces. Conservative terrain choices will be important until the snow stabilizes. Don't forget about other early-season hazards that are lurking just beneath this snow, such as rocks, trees, and creeks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 24th, 2019 5:00PM