Avalanche Forecast
Issued: Mar 13th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Persistent Slabs and Deep Persistent Slabs.
AL,
Avalanche Canada
Precipitation will taper by Tuesday morning. Though snow accumulation values are uncertain we expect the avalanche danger to be elevated due to the formation of storm slabs. Avoid exposure to avalanche terrain as the snowpack adjusts to this new load.
Summary
Confidence
Avalanche Summary
The field team had Limited visibility on Monday. No avalanches observed or reported over the past 24 hours in Little Yoho.
Snowpack Summary
10-30cm of recent storm snow overlays a crust on steep solar aspects and surface hoar/facets on polar aspects. The midpack is comprised of various Jan PWL interfaces (sun crusts, facets, and surface hoar) that are now down 60-120cm. The weaker Nov. 16 basal facet layer is down 110-170 producing variable but mainly hard to no results in pit tests.
Weather Summary
A strong South West flow will continue to bring precip Monday night, with higher snowfall values to the Western slopes of the region. The snow will taper by Tuesday morning as a cold front moves in. By Tuesday morning freezing levels will drop to the valley bottom, and winds will gradually decrease to 30 km/h from the West
For a more detailed weather forecast click here.
Terrain and Travel Advice
- Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Storm Slabs
Up to 30cm of new snow is expected by Tuesday morning for the region. This will be redistributed by moderate winds and will likely form storm slabs on many aspects and elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Three persistent weak layers formed in January are down 60-110 cm. Buried sun crusts found on steep solar slopes present the greatest concern for triggering on these interfaces however weak facets and isolated surface hoar can be found on the same interfaces on shaded aspects. New load may make this layer more reactive.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Weaker facets and depth hoar remain at the bottom of the snowpack in most locations. Be especially cautious in thin snowpack, or rocky areas, where triggering is more likely. Large loads such as cornice failures or smaller avalanches may act as a trigger for this layer so careful consideration of the terrain you travel beneath is wise. Overall we have seen less activity in this region over the past week than further to the East but further load will test that theory.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 14th, 2023 4:00PM
