Avalanche Forecast
Regions: Northwest Inland.
Warm temperatures and strong to extreme west wind are forecast. This will increase the likelihood of cornice failures and build fresh wind slabs. It is uncertain whether the buried persistent weak layers will wake up with the forecast weather.
Confidence
Moderate - Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.
Weather Forecast
Saturday night: Cloudy with some clear periods, trace of new snow, moderate northwest wind, alpine temperature 0 °C, above freezing layer between 1300 m and 2000 m in the south of the region.
Sunday: A mix of sun and clouds, up to 2 cm snow, strong to extreme west wind, alpine high 0 °C, freezing level dropping to 1500 m in the south of the region, and at around 1000 m in the north of the region.Â
Monday: Mainly sunny, up to 3 cm snow, moderate northwest wind, alpine high -8 °C, freezing level around 700 m. Â
Tuesday: Mix of sun and clouds, trace of new snow, light to moderate northeast wind, alpine high -12 °C, freezing level at valley bottom.
Avalanche Summary
Small loose wet avalanche were reported on Friday.Â
The field team reported 2 slab avalanches that had been triggered by cornices earlier in the week. Check out the MIN here.Â
Snowpack Summary
40-60 cm of well settled and bonded snow sits on top of the mid-February crust. Though this layer has not produced avalanche activity, professionals in the area are still treating it with suspicion. The upper snowpack is moist below 1500 m due to warm temperatures. Cornices are looming in alpine areas.Â
The lower snowpack is well bridged by the mid-February crust and triggering avalanches below this layer is unlikely at this time.Â
Terrain and Travel
- Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
- Avoid exposure to slopes that have cornices overhead.
- Cornice failure may trigger large avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Avalanche Problems
Cornices
Cornices are waking up with warm temperatures. A cornice fall can trigger slab avalanches on the slopes below. Cornices can be unpredictable, so it's best to avoid them all together during this warm spell.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Wind Slabs
Strong to extreme west wind will redistribute loose snow where it is available and build fresh wind slabs. Wind slabs can be found in lee terrain features below ridge crests and might be found farther down slope than expected due to the strength of the wind.
Persistent weak layers are buried 30-60 cm deep and consist of weak, feathery surface hoar, a melt-freeze crust or/and facets. Warm temperatures might increase the likelihood of triggering these layers. A triggered wind slab might step down to these layers and result in a larger avalanche than expected.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Loose Wet
It's been warm and wet loose avalanches have been reported. Expect this problem to continue with warm temperatures through the weekend and manage overhead hazard accordingly.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2