Avalanche Forecast
Issued: Dec 28th, 2021 4:00PM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeIf wind speeds increase on Wednesday avalanche danger will be heightened on freshly wind loaded slopes.
Summary
Confidence
Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.
Weather Forecast
Cold arctic air will persist until Sunday.
TUESDAY NIGHT: Clear skies, no precipitation, moderate wind from the north with gusts to 50 km/h, treeline temperatures drop to -15 C.
WEDNESDAY: Mostly sunny with some afternoon clouds, no precipitation, moderate wind from the northwest with gusts to 60 km/h, treeline temperatures around -10 C.
THURSDAY: Cloudy, light flurries with up to 5 cm of low density snow, moderate wind from the northwest with some gusts to 50 km/h, treeline temperatures around -8 C.
FRIDAY: Mostly sunny skies, light wind from the north with gusts to 40 km/h, treeline temperatures around -10 C.
Avalanche Summary
Over the past few days there have been some reports of small (size 1) loose dry avalanches (sluffs) and some small isolated wind slab avalanches. This could change on Wednesday if wind speeds increase and form fresh thicker wind slabs.
Snowpack Summary
With plenty of soft, light snow available for transport, expect wind slab formation at upper elevations if wind speed pick up. A northwesterly wind direction means atypical cross-loading and reverse loading patterns. 20-40 cm now sits over a freezing rain crust below 1500 m and above this elevation it may rest on a layer of large surface hoar crystals. Our field team reported easy shears on this layer in their MIN report last week. The lower snowpack is generally well bonded.
Terrain and Travel
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Avoid freshly wind loaded terrain features.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Sheltered slopes at lower elevations will offer the best riding.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Wind Slabs
With plenty of soft, light snow available for wind transport, we expect to see wind slab formation in the alpine and open areas near treeline. A north or northwest wind means atypical cross-loading and reverse loading patterns. Be especially cautious near ridgetops.
Aspects: North East, East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 29th, 2021 4:00PM