Avalanche Forecast

Issued: Nov 22nd, 2019 3:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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This weekend's storm will start to cover many of the rocks in the mountains. Start off conservatively and assess the bonding within the snowpack. The most likely terrain to trigger an avalanche is where the ground surface appears smooth.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

FRIDAY NIGHT: Cloudy skies with light snowfall, accumulation 2 to 5 cm, moderate to strong west wind, alpine temperature -1 C, freezing level 1500 m.

SATURDAY: Cloudy with snowfall, accumulation 10 to 20 cm, moderate to strong west wind, alpine temperature -2 C, freezing level 1400 m.

SUNDAY: Cloudy with morning snowfall, accumulation 20 to 30 cm, moderate to strong west wind, alpine temperature -5 C, freezing level 1100 m.

MONDAY: Mostly cloudy with light snowfall, accumulation 1 to 3 cm, light west wind, alpine temperature -8 C, freezing level 700 m.

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 ground is smooth, such as on glaciers, rock slabs, scree slopes, or grassy slopes.

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

There is high variability of snow accumulation in the mountains. Below about 1500 m there is presently no snow. At alpine elevations, you may find between about 50 and 100 cm of snow. Snowfall this weekend will accumulate and may not bond well to the underlying snow.

What varies dramatically is the ground roughness -- areas with a lot of ground roughness (for example big boulders, trees) will mean the snow is discontinuous and make it difficult to recreate in but also more difficult to trigger avalanches. 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 avalanche activity is the most likely.

Problems

Storm Slabs

An icon showing Storm Slabs

The new snow this weekend may not bond well to the underlying old snow surface. The most likely place to trigger an avalanche is at alpine elevations where the ground is smooth, for example on glacial ice, scree slopes, grassy slopes, or rock slabs. With the lack of information available this early in the season, it is best to recreate conservatively, be on high alert, and conduct your own assessments throughout the day.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 23rd, 2019 5:00PM