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, Deep Persistent Slabs and 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 as this new snow will add load to an already weak snowpack. Stay out of avalanche terrain for a few days as the snowpack adjusts to the new load.
Summary
Confidence
Moderate
Avalanche Summary
Limited observations on Monday due to poor visibility. No new natural avalanches were observed today. Local ski hill reported several storm/wind slabs initiated by ski cuts to size 1 in the alpine. Explosive control work produced results on the deep persistent problem to size 2.
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 40-80 cm. The weaker Nov. 16 basal facet layer is down 50-120 cm producing variable results in snowpack 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 forecast click here.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Storm Slabs
New snow through the day and overnight Monday with wind will likely develop storm slabs in many areas. There is uncertainty as to how much snow will fall and where. Watch locally for development, and consider overhead exposure as the chance of natural avalanches may increase.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Weaker facets and depth hoar remain at the bottom of the snowpack and inspire little confidence. Depending on how much snow we get Monday and Tuesday, this layer may become more reactive. Be especially cautious in thin or rocky areas, where triggering is more likely. Cornice failures or smaller avalanches may act as a trigger for this layer so careful consideration of the slopes above your head is wise.
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 on steep solar slopes present the greatest concern for triggering, however, weak facets and isolated surface hoar can be found on the same interfaces on shaded aspects. A few avalanches on these layers have been observed in the past week which could become more reactive with increased load.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 14th, 2023 4:00PM
