Avalanche Forecast
Issued: Mar 13th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices, Loose Wet and Wind Slabs.
JSmith,
Avalanche Canada
Overhead hazards such as cornice failures and wet loose avalanches on large alpine slopes will be the primary concern on Sunday. Pay attention to what's above your head and back off of slopes if the snow surface becomes moist.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
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SATURDAY NIGHT: Clear / Strong, southwest ridgetop wind / alpine low temperature -4 / Freezing level 1800 m.
SUNDAY: Sunny with increasing cloud in afternoon / Moderate, southwest ridgetop wind / alpine high temperature 0 / Freezing level 1800 m.
MONDAY: Sunny / Light, west ridgetop wind / alpine high temperature -2 / Freezing level 1400 m.
TUESDAY: Sunny / Light, west ridgetop wind / alpine high temperature -1 / Freezing level 1600 m.
Avalanche Summary
No avalanches were reported in this region on Friday. However, the rapidly rising freezing level and sunny skies are expected to elevate the avalanche hazard through the weekend.
Snowpack Summary
5-15 cm. of recent convective snow and moderate southwesterly winds have formed fresh wind slabs below alpine ridgetops. Dry snow can be found on north aspects and crusty snow surfaces exist on solar aspects. Large cornices loom over alpine ridgetops.
A persistent weak layer made up of surface hoar at treeline elevations and a crust with facets in the alpine on solar aspects can be found down 50-150 cm. in some parts of the region. No recent avalanches have been reported on these layers.Â
Big warm ups can awaken dormant weak layers resulting in large avalanches. Steep, rocky, convex terrain with a shallow or thin to thick snowpack are examples of places where triggering these layers are more likely.
Sunshine and warm temperatures often cause large cornice failures which are hazardous on their own and can also trigger large avalanches on deeper weak layers that the weight of a single rider would not trigger.
Terrain and Travel
- Avoid exposure to slopes that have cornices overhead.
- Cornice failure may trigger large avalanches.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Problems
Cornices
Rapidly rising freezing levels and sunny skies significantly increase the likelihood of cornice failures which are hazardous on their own and can also trigger large avalanches on deeper weak layers that the weight of a single rider would not trigger. Avoid exposure to slopes that have cornices overhead.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Naturally triggered wet loose avalanches are possible, especially on steep solar aspects in the alpine.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Recent convective flurries in parts of the region, solar radiation, and light to moderate winds may have formed reactive slabs in isolated alpine locations. Steep, convex slopes below alpine ridgetops are the most likely places to trigger these slabs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 14th, 2021 4:00PM
