Avalanche Forecast

Archived

Jan 15th, 2024–Jan 16th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

North Columbia, South Columbia, Jordan, Shuswap, West Purcell, Badshot-Battle, Central Selkirk, Goat, Gold, North Okanagan, Whatshan.

Watch for shooting cracks and recent avalanches, these are common signs of instability.

Be cautious in areas where the wind has made the snow feel upside down.

Confidence

Moderate

Avalanche Summary

Natural and remotely triggered slab avalanches are still being reported up to size 2.5 at both alpine and treeline elevations, on west, north, and east aspects. Loose sluffing is also happening in steep terrain.

These avalanches are often associated with a weak layer of surface hoar that was buried in early January. In some cases, a windslab is sitting above this layer of surface hoar.Thursday and Friday of last week saw similar avalanches being reported to size 2.5.

Snowpack Summary

Roughly 40-60 cm of snow fell in the region early last week, which has now been wind affected in the alpine and is faceting with cold temperatures. It buried a mix of crusts, surface hoar, and facets. Areas where surface hoar may be preserved are of greatest concern.

A crust formed by early December rain is found ~70 cm deep, and an old layer of surface hoar is 60-100 cm deep. Recent observations suggest triggering this layer is unlikely. The lower snowpack is variable throughout the region and weak basal facets are likely to be found on the ground in shallow snowpack areas.

Weather Summary

Monday Night

Partly cloudy, west alpine wind 10-50 km/h, treeline temperature -26 °C.

Tuesday

Cloudy with 5-10 cm of snow, southwest alpine wind 10-40 km/h, treeline temperature -16 °C.

Wednesday

Cloudy with 10-15 cm of snow, south alpine wind, 10-30 km/h, treeline temperature -12 °C.

Thursday

Mix of sun and cloud, variable alpine wind 10-20 km/h, treeline temperature -15 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for areas of hard wind slab on alpine features.
Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.