Bulletin d’avalanche

Purcells

Feb 21 – 22, 2022Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Southwest winds have turned northeast and may load unexpected features. Watch for reactivity on all aspects around ridgelines. 

Keep a close eye on south facing slopes as the sun may quickly destabilize the surface snow.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2

    Watch for pockets around ridgelines, loaded from moderate southwest winds. 

    Wind slabs may be also build over the day as east/northeast winds pick up so check for wind loading on all aspects. 

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Watch for moist and wet surface snow on slopes that receive significant sun. Recent dry storm snow could rapidly lose stability with strong solar input. Warming will be most significant around rock features.

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

Arctic air drops temperatures and clears skies this week. Expect mostly sunny days with a chance of occasional flurries.

SUNDAY NIGHT: Mostly cloudy with scattered flurries and light easterly winds. Freezing levels drop to valley bottom.

MONDAY: Mostly clear with scattered cloud, light northeast winds. Freezing levels at valley bottom with alpine highs of -15. Chance of flurries. 

TUESDAY: Mostly clear skies with moderate easterly winds. Freezing levels below valley bottom, with alpine highs of -20. 

WEDNESDAY: Mostly clear skies with moderate westerly winds. with isolated flurries. Light winds. Freezing level valley bottom, high of -15. 

Avalanche Summary

Small human triggered dry loose avalanches were triggered on Saturday as snowfall began to accumulate. 

We expect human triggered slab avalanches to have occurred on Sunday, within the storm snow. 

Snowpack Summary

20-30cm of recent snowfall sits over a melt freeze crust on solar aspects at all elevations, and wind effected surfaces in exposed terrain. In sheltered terrain features a small layer of surface hoar may exists above the melt freeze crust.

A layer of buried surface hoar sits 30-50cm deep in the upper snowpack, most likely to be found and triggered on north aspects in sheltered areas. This layer has produced variable results in recent snowpack tests, and could be triggered by very large loads such as a cornice fall or step down avalanche. 

The lower snowpack is well consolidated, with a crust/facet layer found 80 to 150 cm deep. It is currently considered dormant, but could become active later this season. Check out the forecaster blog for more information. 

Terrain and Travel

  • The new snow could use a day or two to settle and stabilize before we start to tee up the bigger lines.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Régions couvertes