Avalanche Forecast

Issued: Dec 8th, 2019 4:00PM

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

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Triggering avalanches is possible where wind slabs have formed in the alpine.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

SUNDAY NIGHT: Clear with some clouds, 30 km/h wind from the northwest, temperature inversion with alpine temperatures above freezing and dropping to -6 C in valleys.

MONDAY: Mix of sun and cloud, 40 km/h wind from the south, temperature inversion with alpine temperatures up to +2 C.

TUESDAY: Increasing cloud with light flurries starting in the evening, 40-60 km/h wind from the south, alpine high temperatures around -2 C.

WEDNESDAY: Snow increasing in intensity throughout the day with 10-20 cm possible by the afternoon, 70-90 km/h wind from the south, alpine high temperatures around -2 C.

Avalanche Summary

The last reported avalanches were wind slab avalanches in alpine terrain on Thursday and Friday, including a small (size 1) skier triggered wind slab near Shames (see this MIN report). Triggering wind slabs remains possible in alpine terrain.

Snowpack Summary

Open terrain is heavily wind affected, while softer snow can be found in sheltered terrain. At upper elevations recently formed wind slabs may be sitting on a mix of sugary faceted snow or feathery surface hoar crystals, which could make them reactive to human triggering. Warm alpine temperatures and sunny weather on Monday could also weaken these slabs. Snowpack depths at treeline are likely in the 90-160 cm range, tapering quickly at lower elevations.

Problems

Wind Slabs

An icon showing Wind Slabs

Hard wind slabs exist in alpine terrain and may become more reactive to human triggering on Monday due to warm alpine temperatures.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 9th, 2019 4:00PM