Bulletin d’avalanche

Jasper

Mar 19 – 20, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

The region is trending towards spring like conditions. Start early and finish early as the sun is having the strongest effect typically by mid-afternoon. It is wise to choose ice climbs with no overhead hazard and least amount of overall sun exposure.

Problèmes avalancheux

  • Persistent Slabs

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

    The 20cm of storm snow from March 13th has been periodically blown around, redistributed, settled, and has combined with the larger snowpack structure for the most part. Their is a cornucopia of interfaces throughout the snowpack depending on aspect, elevation, and local terrain influences. There have been a few avalanches this past week which appeared to have stepped down to multiple layers. Sun will increase potential reactivity.

  • Loose Wet

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

    Loose wet snow avalanche activity is increasing as afternoons are getting dramatically warm. These types of avalanches can be what initiate larger slag avalanches. Temperatures are ranging from -15 at night to +8 in the afternoon.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–3.5

    The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Wind slab avalanches have stepped down to the deep persistent slab since the last storm meaning large triggers can influence this basal weakness. The likelihood is slowly increasing for this high consequence avalanche problem.

Confidence

Moderate

Avalanche Summary

Sunday's Icefield patrol noted several low elevation loose wet slides up to size 2. A couple of these were at higher elevation solar aspects. A few deep slabs were also noted on alpine East aspects. Saturday at 5pm a size 2 loose wet roadside slope hit highway 93 burying both lanes for 10metres. A large, likely ice or cornice triggered and solar influenced avalanche, was directly observed at 1:30 in the Stutfield valley. See MIN report.

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

Snowpack Summary

A suncrust has formed on solar aspects at all elevations. This caps off the 15-20cm of new snow from March 13th. Moderate SW winds after March 13th created pockets of windslab on lee aspects. Approximately 20-30cm down is a buried sun crust at low elevations on steep southerly slopes and a surface facet layer in sheltered terrain. The mid-pack is 40 to 80cm of supportive snow. Near the ground it is generally weak with large facets and depth hoar.

Weather Summary

Monday will be sun and cloud, -4 °C, light Northeast winds, and 1700 metres freezing level. Tuesday and Wednesday will be similar except for 2200 metres freezing level on Wednesday.

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

Terrain and Travel Advice

  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Be alert to conditions that change with elevation and sun exposure.

Régions couvertes