Avalanche Forecast
Issued: Mar 15th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices.
ldreier,
Avalanche Canada
We are entering a classic diurnal cycle in the next couple of days with a good refreeze at night and daytime warming except for the south of the region where temperatures stay elevated overnight. Cornices might weaken with sun-exposure and during the heat of the day.
Summary
Confidence
High - We have a good understanding of the snowpack structure and confidence in the weather forecast
Weather Forecast
MONDAY NIGHT: Clear with some clouds, 10 km/h west wind, alpine low -12 C, freezing level lowering to 1000 m in southern half of the region and at valley bottom in the northern half of the region.Â
TUESDAY: Mostly sunny, 10 km/h northwest wind, alpine high 1 C, freezing level 1800 m.
WEDNESDAY: Mostly sunny, 20 km/h southeast wind, alpine high 4 C, freezing level 2000 m.
THURSDAY: Increasing cloud coverage, trace of new snow, 30 km/h southeast wind, alpine high 5 C, freezing level 2100 m.
Avalanche Summary
Several natural and explosives triggered wet loose avalanches up to size 3 on steep solar aspects were reported on Sunday. A large cornice failure (size 2.5) was observed and did not trigger a slab on the slope below. A large glide snow avalanche (size 2.5) was observed on a south aspect at treeline. A small wind slab pocket was triggered by a skier.
Numerous natural wet loose avalanches up to size 2.5 were observed on solar aspects as well as on polar aspects up to 2100 m on Saturday. Several cornice failures up to size 2.5 during the heat of the day were reported. The cornices did not trigger slabs on the slopes below. A large glide snow avalanche (size 2.5) released naturally. Explosives triggered a persistent slab avalanche of size 3 in the southeast of the region.Â
Small size 1 naturally triggered wind slabs on north aspects and size 1 wet loose avalanches on solar aspects in the alpine were reported on Friday.
Snowpack Summary
Sunny skies and warm temperatures formed sun crusts on solar aspects at all elevations and up to 2000 m on polar aspects. Dry snow still exists on north aspects at upper elevations. Large cornices loom over alpine ridgetops.
Persistent weak layers of surface hoar, crusts, and/or facets 80-120 cm down have recently been unreactive except for an explosives triggered avalanche in the southeast of the region on Saturday.Â
Terrain and Travel
- Cornices become weak with daytime heating or solar exposure.
- Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches
Problems
Cornices
Especially in the southern half of the region where temperatures stay elevated overnight, warm temperatures and sunny skies can increase the likelihood of cornice failures. A cornice fall can be hazardous on its own. Minimize exposure to slopes that have cornices overhead, especially during the heat of the day.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 16th, 2021 4:00PM
