Avalanche Forecast
Issued: Dec 13th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Loose Wet.
jminifie,
Avalanche Canada
It's Spring time in December! Warm, clear weather will make travel conditions favourable for the next few days but keep in mind that continuous warm temperatures could destabilize both the upper and lower snowpack.
Summary
Confidence
Avalanche Summary
No new avalanches were reported over the weekend though evidence of a small natural avalanche cycle was reported through the most recent storm.
Whumpfing was reported from the Mt. Washington area on Sunday in recent Mountain Information Network reports.
Keep sharing your observations by submitting a MIN report! They are especially helpful in the early season when snowpack information can be limited.
Snowpack Summary
The combination of warm temperatures and solar input will destabilize the upper snowpack and potentially the lower snowpack over the next few days. North winds could act to temper this warming but now is a good time to manage overhead hazard and use caution in large terrain features.
Higher elevation snowpack depths range from 100-140cm. A layer exists in the lower snowpack that is comprised of a crust and weak, sugary facet crystals. Avalanche professionals in the area reported moderate Sudden Planar snowpack tests and whumpfing on this layer over the weekend. This could be something to investigate further before committing to larger pieces of terrain.
Weather Summary
Tuesday night
Partly cloudy. Trace amounts of new snow. Winds from the north at 10km/h. Temperature at -4˚C.
Wednesday
Mostly clear skies. Winds from the northwest at 15km/h. A strong inversion will bring alpine temperatures up to +2˚C.
Thursday
Mostly clear skies. Winds from the northwest at 25km/h. Alpine temperatures up to +3˚C.
Friday
Mostly clear skies. Winds from the northwest at 15km/h. Alpine temperatures up to +3˚C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Problems
Deep Persistent Slabs
A layer involving a crust and sugary facets has been reported to exist in the lower snowpack. This layer has produced whumpfs and planar snowpack test results. With warm weather forecast for the coming days under an inversion, one should investigate this layer further and be suspicious of larger, convex terrain features and places with smooth ground cover offering little to anchor the snowpack in place.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Even though it's December, steep solar aspects could produce loose wet avalanches with warm alpine temperatures during the inversion over the next few days. Keep an eye on daytime warming and remember that loose wet avalanches can step down to deeper instabilities.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 14th, 2022 4:00PM
