Avalanche Forecast
Issued: Jan 18th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
zryan,
Avalanche Canada
Storm slabs have been reactive to human triggering, particularly in wind loaded terrain. Where a slab is not found dry loose avalanches are likely.
Summary
Confidence
Moderate
Avalanche Summary
On Wednesday, numerous natural and human-triggered storm slabs (size 1-2) were reported in the alpine and treeline. Where the storm snow remained loose and uncohesive, widespread dry loose activity was reported with skier traffic in steep terrain.
Look forward to Friday, storm slab reactivity is expected to persist, especially in wind-affected terrain. Dry loose power sluffing may be the name of the game in most places that are sheltered from the wind.
Snowpack Summary
20 to 30 cm of recent storm snow has buried a variety of snow surfaces. It sits above unconsolidated faceted snow, surface hoar and firm wind-pressed snow in open terrain at treeline and above.
Down 60-80 cm, a crust, facet and or surface hoar layer exists. This may become a problem once the snow above starts to stiffen and form a slab.
130+ cm down another surface hoar layer exists that was buried in early December. This seems to be of most concern above 2000 m where a robust crust doesn't exist above it.
Weak basal facets are likely to be found on the ground in shallow snowpack areas.
Weather Summary
Thursday Night
Mainly clear, with cloud cover increasing in the early morning and no new snow. Alpine wind light from the southeast. Treeline temperature around -15 °C.
Friday
Cloudy with snowfall, up to 10 cm of accumulation. Alpine wind south 15 to 40 km/h. Treeline temperature rising to -8 °C.
Saturday
Cloudy with light snowfall, up to 5 cm of accumulation. Alpine wind south 10 to 30 km/h. Treeline temperature rising to -5 C.
Sunday
Cloudy with light snowfall, up to 5 cm of accumulation. Alpine wind south 10 to 30 km/h. Treeline temperature rising to -5 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
Problems
Storm Slabs
Storm slabs may remain reactive, especially in wind affected terrain.
Dry loose power sluffing will likely exist in wind sheltered terrain, especially on steep slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
50-80 cm sits above a crust and surface hoar which has produced natural, remote and rider-triggered avalanches in the past week. As the unconsolidated snow settles and forms a slab, a reactive upper snowpack may exist.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Jan 19th, 2024 4:00PM
