Bulletin d’avalanche

Banff Yoho Kootenay

Jan 27 – 28, 2015Parks Canada
Voir sur la carte
Archivé · expiré 12 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
4 · Fort
Ouvrir la carte complète

Points saillants

Although we are past the peak of the current avalanche cycle, we expect one more day of warm temperatures and have kept the BTL danger rated as HIGH. Conditions will improve dramatically with the onset of more seasonal temperatures on Thursday.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Very strong SW winds over the past few days have created deep windslabs above treeline. These slabs have the potential to trigger the deeper layers in the snowpack, making for a large avalanches. Avoid all windloaded terrain.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–2
    Wet avalanches will continue to occur on Tuesday at low elevations. Ice climbers should avoid avalanche terrain, in particular the gullies where wet avalanches have been running.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    2–3
    The snowpack is structurally very weak - one of the weakest snowpacks seen in years - the facets and depth hoar near the base of the snowpack will produce large avalanches when triggered.

Weather Forecast

Slowly, ever so slowly, the temperatures are starting to fall.  Overnight and Tuesday expect freezing levels to drop below treeline with lows of -4 in some areas.  No precipitation is expected through the remainder of the week as the slow cooling continues.  By Thursday temperatures are expected to hit -12, which should lock the snowpack down.

Snowpack Summary

Warm temperatures are having a dramatic effect on the snowpack. Below 2000m the snowpack is wet and isothermal in many areas, particularly on sun exposed terrain and around rocks. Above 2000m moist snow has been blown to smithereens by yesterdays wind and deep, drifted windslabs can be expected in alpine areas. The snowpack is in a very weak state.

Avalanche Summary

A widespread avalanche cycle occurred on Sunday with dozens of large avalanches observed on all aspects, and at all elevations with lower elevations being particularly active. Monday saw less activity, but avalanche control near Mt Wilson produced a large avalanche onto the 93N highway. Avalanches continue to be reported every few hours.

Confidence

Régions couvertes