Bulletin d’avalanche

Cirrus-Wilson

Feb 8 – 9, 2023Avalanche Canada
Voir sur la carte
Archivé · expiré 4 years ago

Danger d’avalanche

Fri
Sat
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué

Points saillants

Prevailing storm expected to produce another 15cm new snow overnight into Wednesday. Highway 93N closure in effect from Parker Summer to Saskatchewan Crossing with avalanche control planned for Wednesday. Check 511 for updates.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–2.5

    Up to 35cm new snow with moderate to strong southwest winds. This will be adding to existing and creating new wind slabs in the alpine and exposed tree line features.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1.5–2.5

    Up to 35cm of new snow by Wednesday morning. This may be enough to activate a natural avalanche cycle with the settling storm snow.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1.5–3

    The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Avalanches initiating in the upper snowpack are likely to step down to this layer and gain significant mass.

Confidence

Moderate

Avalanche Summary

No avalanche activity noted on Tuesday's patrol but visibility was poor. Feb 5th Icefield patrol reported one large natural avalanche triggered by glacial ice.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

Up to 20cm new snow fell Tuesday in the Icefields area with an additional 15cm possible overnight into Wednesday morning. This new snow adds to 20cm of settled snow from early February sitting on a weak melt freeze crust facet combo below 2100m. Generally, the mid and bottom of the snowpack is weak facets with depth hoar at the base. The snowpack ranges from 60 to 140cm.

Weather Summary

The tail end of a low pressure system is expected to bring an additional 15cm of new snow in the Icefields area overnight Tuesday into Wednesday morning. Winds will be moderate to strong from the southwest and west - freezing level will remain at valley bottom. Clearing trend is expected on Wednesday with continued moderate to strong westerly winds.

Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch for signs of slab formation throughout the day.

Régions couvertes