Avalanche Forecast
Issued: Feb 18th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Deep Persistent Slabs.
jsmith,
Avalanche Canada
Forecast snow and wind Saturday night and into Sunday will build reactive storm slabs. Large, natural avalanches may occur at upper elevations and human-triggered avalanches are expected at all elevations.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
Summary
Confidence
Moderate
Avalanche Summary
Forecast snow and wind on Sunday will build reactive storm slabs. Large, natural avalanches may occur at upper elevations and human-triggered avalanches are expected at all elevations.
Snowpack Summary
Recent snowfall amounts have varied widely across the region with Pine Pass, Core Lodge riding area, and the southwest receiving the highest amounts of 20-30 cm.
Forecast snow and wind on Sunday will build reactive storm slabs. Large, natural avalanches may occur at upper elevations and human-triggered avalanches will be likely at all elevations.
The mid-pack is gaining strength and consists of rounding facets and melt-freeze crusts that are starting to degrade. A spotty surface hoar layer buried around January 4th can still be found between 60 to 80 cm. Avalanche activity has not been reported on this layer recently but it is still showing up in snowpack tests.
Near the base of the snowpack, a persistent weak layer composed of large and weak facets formed in November is strengthening slowly. This layer is most likely to be triggered in thin, rocky alpine and upper treeline terrain.
Weather Summary
Saturday night
Snow; 10-25 cm / Strong west ridgetop wind / Low -8 °C / Freezing level valley bottom.
Sunday
Snow; 10-25 cm / Strong west ridgetop wind / High -1 °C / Freezing level 1200 m.
Monday
Mix of sun and cloud / Light northwest ridgetop wind / High of -5 °C / Freezing level valley bottom.
Tuesday
Mostly sunny / Moderate northeast ridgetop wind / High of -18 °C / Freezing level valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
- Minimize exposure during periods of heavy loading from new snow and wind.
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Use small low consequence slopes to test the bond of the new snow.
Problems
Storm Slabs
Forecast snow and wind on Sunday will build reactive storm slabs. Large, natural avalanches may occur at upper elevations and human-triggered avalanches are expected at all elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large, weak facets sits near the base of the snowpack. This layer is most prominent in the upper treeline and lower alpine elevations. This layer may be triggered by large loads like a wind slab avalanche that steps down to deeper layers or a cornice release.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 19th, 2023 4:00PM
