Bulletin d’avalanche

Banff Yoho Kootenay

Mar 20 – 21, 2019Parks Canada
Voir sur la carte
Archivé · expiré 8 years ago

Danger d’avalanche

Fri
Sat
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort
Ouvrir la carte complète

Points saillants

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=34810&oPark=100092 The diurnal avalanche cycle prompted by day time heating continues. Avalanches are starting to dig deeper at lower elevations. Time your trips be done by noon or before the avalanche activity starts as the crusts break down...

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–3
    10-50 cm settled snow (since Mar 7) has formed slabs above treeline due to winds and warm temperatures. They sit over a variety of weaker surfaces. Natural and skier triggering of this recent snow has occurred in the last several days on all aspects.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Certain
    Taille
    1–3
    Rapidly warming daytime temperatures and high solar inputs are causing loose wet avalanches to start by mid morning. Some of these are running long distances or triggering slabs along the way. Avoid exposure to these slopes when they heat up.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3.5
    We have seen a few avalanches failing on the basal weaknesses and scrubbing to ground. This is mostly occurring with large triggers in thin rocky areas but we expect this type of avalanche activity to increase with more heat.

Weather Forecast

Expect  similar weather tomorrow with generally clear skies again tonight to help freeze the snowpack despite the relatively warm overnight temperatures. Conditions will deteriorate rapidly Thursday with daytime heating. Temperatures at treeline will climb to 10-15C. Temperatures will cool Saturday as the ridge moves east allowing cloud to move in.

Snowpack Summary

Sun crusts or moist snow on solar aspects and isothermal snow at lower elevations. Above treeline, 10-50 cm of recent snow sits over a mix of facets, sun crust and wind slabs.  While a supportive mid-pack exists in thicker areas, very weak facets to the ground are seen in many thinner areas.

Avalanche Summary

A widespread spring avalanche cycle continues with the bulk occurring on solar aspects as they heat up through the day. Avalanche size ranged from size 1-3. Most slides have been within the surface snow (March 7 interface) with some stepping down a bit deeper; however, we have seen only a few avalanche step down to the basal layers.

Confidence

Due to the quality of field observations on Wednesday

Régions couvertes