Avalanche Forecast
Issued: Mar 18th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
jsmith,
Avalanche Canada
Lingering wind slabs may remain reactive to human triggers in isolated locations at upper elevations.
Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Summary
Confidence
Moderate
Avalanche Summary
A few size 1.5 loose dry avalanches triggered by solar radiation were reported on sunny aspects at treeline and above on Friday.
A couple cornice triggered wind slabs up to size 2.5 were reported on steep, northerly aspects in the alpine on Thursday.
Snowpack Summary
Expect to find a melt-freeze crust on the surface of all aspects at treeline and below and on sunny aspects in the alpine. Solar radiation will break down the crust on sunny slopes throughout the day.
Lingering wind slabs formed by snow and wind earlier in the week may remain reactive to human triggers in isolated locations in the alpine.
The middle of the snowpack is generally well-settled and strong.
A weak layer of large facets is found near the base of the snowpack. This layer is of most significant concern in shallow snowpack areas in the north and east of the region. The most likely areas to trigger this layer are shallow, rocky areas or where the snowpack transitions from thin to thick.
Weather Summary
Saturday Night
Clear skies / 10 km/h south ridgetop wind / Temperature at treeline around -8 C / Freezing level valley bottom
Sunday
Sunny / 20 km/h east ridgetop wind / Temperature at treeline around -1 C / Freezing level 1800 m
Monday
Sunny / 20 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1700 m
Tuesday
Sunny / 10 km/h northeast ridgetop wind / Temperature at treeline around -3 C / Freezing level 1500 m
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
- Carefully evaluate steep lines for wind slabs.
- Cornice failure may trigger large avalanches.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Problems
Wind Slabs
Lingering wind slabs may remain reactive to human triggers in isolated locations at upper elevations.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 19th, 2023 4:00PM
