Avalanche Forecast
Issued: Jan 1st, 2023 4:00PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeHuman triggering of large, persistent slab avalanches remains possible. Continue to stay disciplined and make conservative terrain choices.
Summary
Confidence
Moderate
Avalanche Summary
Daily reports continue to come in of very large natural and human-triggered slab avalanches (size 2 to 3) failing on persistent weak layers deep in the snowpack. Along with smaller avalanches on the surface stepping down to deeper layers. Many of these human-triggered avalanches were a surprise to the individuals triggering them.
This recent Mountain Conditions Report submission paints a spooky picture of the current state of the snowpack.
Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Roughly 50 to 70 cm of new snow continues to settle and bond over a weak layer buried just before Christmas. This layer consists of sugary faceted grains and/or small surface hoar and has been responsible for numerous large natural and human-triggered avalanches since December 27.
The mid and lower snowpack generally remains weak and facetted, with a number of weak layers present. A layer of particular concern that was buried in November, consists of weak facets, surface hoar, and/or a thin crust, and is roughly 100 to 150 cm down from the surface.
Snowpack depths are roughly 150 to 200 cm at treeline.
Weather Summary
Sunday night
Mainly cloudy, with no precipitation. Light southwest winds. -5 to -10 C at treeline.
Monday
A mix of sun and cloud, no precipitation. Light southwest winds. -5 to -10 C at treeline. Potential for a strong temperature inversion in the alpine.
Tuesday
A mix of sun and cloud, no precipitation. Light southwest winds. -5 to -10 C at treeline. Potential for a strong temperature inversion in the alpine.
Wednesday
Mainly cloudy, with flurries. Light southerly winds. -5 to -10 C at treeline.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Choose simple, low-angle, well supported terrain without convexities.
- Be especially cautious as you transition into wind affected terrain.
Problems
Persistent Slabs
Several weak layers persist deep in the snowpack. Use extra caution where the snowpack varies from thick to thin, near rock outcrops and convexities. Larger-than-expected avalanches are possible due to the likelihood of avalanches stepping down deeper weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Recent winds have created wind slabs in localized open terrain and near ridge tops. Slabs in motion may step down to deeper weak layers, resulting in large avalanches.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 2nd, 2023 4:00PM