Bollettino valanghe

Lizard-Flathead

Dec 31, 2022 – Jan 1, 2023Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Mon
Tue
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

The snowpack is slowly gaining strength, but triggering large persistent slab avalanches remains possible. Approach avalanche terrain with caution and stick to smaller pieces of terrain.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Buried weak layers were reactive earlier this week during the warm stormy weather and although they are likely gaining strength, the possibility of triggering a large persistent slab avalanche remains a concern. There are two weak layers, both composed of surface hoar and facets, anywhere from 40 to 150 cm deep. Triggering an avalanche on these layers is possible on steep, convex, or rocky slopes. Steep open trees are also suspect since this terrain could have preserved surface hoar.

Confidence

Moderate

Avalanche Summary

A natural cycle of large and very large avalanches (size 2 to 3) occurred earlier this week, and explosive control has continued to produce large avalanches as recently as Friday. Most of the avalanches were in storm snow layers, however some are suspected to have stepped down to deeper weak layers, especially those in the Sparwood and Elkford areas. We suspect it is becoming more difficult to trigger storm and persistent slab avalanches, however caution should be taken in challenging or complex terrain given the uncertainty and consequence of these large avalanches.

Snowpack Summary

A dusting of new snow is falling on top of settled snow from the December 26th storm. This storm left roughly 50 cm of heavy snow above a rain crust that extends to treeline elevations. While the recent snow has shown signs of settling and strengthening, there are two deeper layers of concern that may still be possible to trigger in specific terrain. This includes a 40 to 80 cm deep layer of surface hoar and facets that was buried in mid-December and an 80 to 150 cm deep layer of surface hoar and facets that was buried in mid-November. These layers are at the deeper end of these ranges in Lizard Range and Fernie areas and the shallower end of the range towards Sparwood and Elkford. The persistent slab above these layers may be easier to trigger around Sparwood and Elkford, because they are closer to the surface.

Weather Summary

Friday night

Light snowfall with 5 to 10 cm in the Lizard range and a trace to 5 cm elsewhere, 30 to 40 km/h wind from the southwest, treeline temperatures around -5 °C.

Saturday

Cloudy with light snowfall and localized accumulations up to 5 cm, 30 to 40 km/h wind from the southwest, treeline temperatures around -5 °C.

Sunday

Partly cloudy with sunny breaks in the afternoon, no precipitation, 20 to 30 km/h wind from the west, treeline temperatures around -7 °C.

Monday

Mix of sun and cloud, no precipitation, light wind, treeline temperatures around -9 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Regioni coperte