Avalanche Forecast
Issued: Nov 24th, 2019 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
ghelgeson,
Avalanche Canada
30+cm of snow with strong wind has left us with two problems:
A potentially touchy storm slab.
A persistent slab that may remain sensitive to triggering.
Watch for signs of unstable snow and gather more info, especially if you're pushing beyond simple terrain.
Summary
Confidence
Low - Uncertainty is due to the limited number of field observations.
Weather Forecast
After a stormy weekend we’re transitioning to clearing skies, colder temperatures and no significant precipitation for the foreseeable future.
SUNDAY NIGHT: Freezing level dropping to Valley Bottom, light west/northwest wind, trace of snow possible.
MONDAY: Broken cloud cover, freezing level at valley bottom, light NW breeze, no significant precipitation expected.
TUESDAY: Scattered cloud cover, freezing level at valley bottom, light variable breeze, no significant precipitation expected.
WEDNESDAY: A few clouds at dawn building to broken cloud cover in the afternoon, freezing level at valley bottom, moderate east wind, no significant precipitation expected.
Avalanche Summary
We're flying nearly blind here with very limited observations, but this MIN report from the neighboring Glacier National Park region helps to paint a picture of how touchy the storm slab problem was on Saturday. A natural size 2 storm slab was also observed in a north facing alpine feature near Revelstoke, but we suspect a much larger natural avalanche cycle occurred. If you were out Sunday please let us know what you're seeing by submitting to the MIN.
Snowpack Summary
Early season conditions are highly variable. Snow line begins around 1200 m, and the snowpack depth ranges from 50 cm to 150 cm. Â
The weekend storm produced 20 to 35 cm of snow accompanied by strong west/southwest wind. On steep south facing slopes in the alpine the new snow rests on a crust. A crust is also present on all aspects below 1600 m and many locations have surface hoar on top of the crust.
Crusts that formed in late October are now buried 50 to 90 cm deep. We're working off of a short list of observations, but this late October crust layer is highly variable and may be associated with both surface hoar and facets. This is a layer to watch over the next week as unlimited visibility and good travel conditions begin to sing the Alpine's siren song.
Problems
Storm Slabs
The weekend storm produced 20 to 35 cm of snow accompanied by strong west/southwest wind forming widespread storm slabs. These slabs rest on a variety of weak layers which will likely keep them susceptible to human triggering Monday, especially in bigger terrain near ridge crest.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Crusts that formed in late October are now buried 50 to 90 cm deep. We're working off a short list of observations, but this late October layer is highly variable and may be associated with both surface hoar and facets. This is a layer to test and watch over the next week as unlimited visibility and good travel conditions begin to sing the Alpine's siren song.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 25th, 2019 5:00PM
