Avalanche Forecast
Issued: Jan 3rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
isnowsell,
Avalanche Canada
Large human-triggered avalanches continue to be possible. Stay disciplined and make conservative terrain choices.
Summary
Confidence
Moderate
Avalanche Summary
Numerous large to very large (size 2 to 3) avalanches were triggered by riders, explosives, and naturally on Monday, failing on the weak layers described in the Snowpack Summary. Most avalanches were between 1800 m and 2500 m, 70 to 200 cm deep, and on all aspects. Here is an example. These avalanches continue to show us that these buried layers are triggerable and high consequences would result from being caught. Many of these human-triggered avalanches were a surprise to the individuals triggering them.
Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Light, low-density snow on the surface sits on top of a settled and bonding upper snowpack. A weak layer buried just before Christmas is 40 to 70 cm down from the surface. The lower snowpack is generally weak and facetted, with a weak layer buried in November, consisting of large, weak facets near the bottom of the snowpack.
Snowpack depths are roughly 150 to 200 cm at treeline.
Weather Summary
Tuesday night
Cloudy with no precipitation. Light south winds. -10 C at treeline.
Wednesday
A mix of sun and cloud, no precipitation. Light southeast winds. -10 C at treeline.
Thursday
A mix of sun and cloud, with flurries. Light to moderate southeast winds. -5 to -10 C at treeline.
Friday
Cloudy with flurries. Moderate southerly winds. -5 to -10 C at treeline.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Choose simple, low-angle, well supported terrain without convexities.
Problems
Persistent Slabs
Multiple weak layers persist deep in the snowpack. Two of these layers are the primary concern and are responsible for most of the recent large avalanche activity. A layer buried in late December is down roughly 40 to 70 cm from the surface and consists of surface hoar, facets and/or a crust. While a layer near the bottom of snowpack buried in November generally consists of large, weak facets.
Although widespread, both layers appear to be most reactive around treeline and lower alpine elevations, in terrain with shallow, variable snow depths.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 4th, 2023 4:00PM
