Bollettino valanghe

North Columbia

Feb 16 – 17, 2023Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 4 years ago

Pericolo valanghe

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

In sintesi

As a new storm travels south snow will start to accumulate throughout the day adding to the snow available for transport. Be aware of changing conditions throughout the day, and investigate the bond of old wind slabs in direct lees.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    Wind slabs continue to be reactive to human triggers, this problem is found at upper elevations directly lee of ridges.

  • Persistent Slabs

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

    Problematic weak layers are becoming spotty across the region, however recent large persistent slab avalanche observations continue to trickle in reminding us that these layers remain a concern in this region. Recent avalanches have been triggered by a mix of large loads like cornices.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–4

    A layer of large and weak facets sits near the base of the snowpack. This layer continues on a sporadic basis to produce very large avalanches that can travel far. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain, or by triggering a smaller avalanche that could step down to this layer. Cornices will continue to grow with new snow and wind and could be the large load needed to trigger deep persistent weak layers. Your best defense is to stay diligent in choosing low-consequence terrain away from overhead exposure.

Confidence

Moderate

Avalanche Summary

Several natural very large avalanches were reported in the North of the region that failed down to the deep persistent weak layer found near the base of the snowpack.

Reports of natural and cornice-triggered wind slabs continue to trickle in, reminding us that human triggering of these layers remains possible.

Snowpack Summary

The upper snowpack consists of recent snow that has been redistributed into wind slabs directly lee of ridges at treeline and alpine elevations. Various ages of wind slabs and storm snow is generally settling and bonding.

The mid-pack is generally well consolidated with a few operations reporting continued snowpack results on a spotty surface hoar layer down roughly 80 cm. Reports of large avalanches involving various layers of surface hoar/crusts and facets within the mid-pack depth are sporadic but are a reminder of the complicated snowpack across this region.

In the lower snowpack, a layer of large and weak facets from November near the base of the snowpack remains on the radar and continues to be discussed in professional snowpack summaries.

Weather Summary

Wednesday night

Increasing cloud with isolated flurries, trace accumulations, 10 to 15 km/h southwest winds, treeline temperatures around -6 °C.

Thursday

Cloudy with flurries, 5 to 10 cm accumulation, 10 to 15 km/h southwest wind, treeline temperatures -7 °C.

Friday

Mainly cloudy, flurries 5 to 10 cm of new snow, 20 to 30 km/h winds, treeline temperatures -8 °C.

Saturday

Mainly cloudy, flurries with 5 to 10 cm accumulation, 20 to 30 km/h southwest winds, treeline temperatures -7 °C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
  • Be especially cautious as you transition into wind affected terrain.
  • Watch for areas of hard wind slab on alpine features.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Cornices become weak with daytime heating or solar exposure.

Regioni coperte