Avalanche Forecast
Issued: Jan 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
wlewis,
Avalanche Canada
Expect wind loading around ridgelines as northeasterly winds continue to redistribute storm snow into unusual loading patterns.
Use extra caution around ridgelines and avoid rocky start zones. Low angle, wind sheltered slopes will hold the best conditions.
Summary
Confidence
Moderate
Avalanche Summary
Storm slab and loose dry avalanches were reported on Friday as snowfall accumulated.
Avalanche control work near Fernie this week produced wind slabs to size 1.5 from explosive and ski cut methods.
Although the deep persistent slab problem has not produced in they have not produced any avalanches for some time it could still pose a threat for now. Be wary of areas with thin or variable depth snowpack and shallow rocky start zones throughout the region.
Snowpack Summary
Up to 30 cm of storm snow can be found, wind affected by moderate north/east winds at higher elevations. New snow sits over wind affected surfaces at higher elevations and at lower, sheltered elevations - over a layer of surface hoar on sheltered areas or a melt freeze crust on south facing slopes.
A crust and facet layer from mid January, 2 to 15 cm thick at treeline sits 50 to 90 cm deep. Where it's thickest, it caps the settled and consolidated mid-snowpack.
The lower snowpack contains weak and facetted grains from November. Concern remains for heavy loads such as cornice falls, machine triggers or step down avalanches. Thin snowpack areas where weak layers sit closer to the surface should still be treated as suspect.
The total snowpack depth ranges between 90 and 250 cm.
Weather Summary
Saturday Night
Some cloud overnight. Moderate northeast winds. Freezing levels below valley bottom. Trace accumulations.
Sunday
Sunny with trace amounts of snow expected. Moderate northerly winds continue, alpine high temperatures of -16°C.
Monday
Sunny with increasing afternoon cloud. Winds switch to moderate (gusting strong) westerlies. Alpine high of -16°C.
Tuesday
A mix of sun and cloud. Moderate westerlies. Alpine high of -12°C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Expect to find wind slabs at higher elevations. Up to 30 cm of recent snow can be found throughout this region, available to be redistributed by northeast winds. Primary concern is for south and west facing terrain features but recent winds have varied throughout the region - look for wind affected snow on all aspects as you approach or descend from ridgelines.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Faceted grains make up the lower snowpack and are gaining strength very slowly. This layer has been relatively inactive recently but can still be triggered with a heavier load, like a cornice fall, machine trigger, and in areas with a thinner snowpack. Any avalanche triggered this deep will likely be large and destructive.
Use caution in thin snowpack areas, like wind affected rocky start zones.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 29th, 2023 4:00PM
