Bollettino valanghe

North Columbia

Jan 1 – 2, 2022Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 5 years ago

Pericolo valanghe

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

In sintesi

 Keep an eye on the wind. Avalanche hazard will likely increase throughout the day as the strong winds build small but reactive slabs. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    New wind slabs will form throughout the day on Saturday. These new slabs will likely be limited in size but sensitive to rider traffic due to the fact that they will form over faceted and wind effected surfaces. Strong winds mean that these slabs could be found further down slope then expected. Sensitivity to triggering will be greatest where wind slab has formed over Surface hoar in the treeline and below.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–3.5

    We continue to receive sporadic reports of people triggering a weak layer of faceted grains around a melt-freeze crust that formed in early December. This layer is found around 80 to 150 cm deep and is most common at elevations between 1700 m and 2200 m. Read more about it here.

Confidence

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Weather Forecast

Friday night: light northwest winds in the alpine with no new snow expected. low of -30 at 1500m.

SATURDAY: strong southwest winds with around 10cm of new snow expected. High of -18 at 1500m.

SUNDAY: strong southwest winds in the alpine with up to 10cm of new snow expected. High of -12 at 1500m.

Monday: light snow all day with light to moderate southwest winds in the alpine. High of -9 at 1500m.

Avalanche Summary

A few wind slabs up to size 2 were observed on northerly and southerly aspects at the treeline elevation. Several natural cornice failures were also observed on all aspects.

The latest avalanche activity on the early-December weak layer described in the snowpack summary was from Monday. This included two natural avalanches and one triggered by a rider. They were large (size 2 to 3), observed on all aspects, and found between 1700 m and up to 2600 m.

Snowpack Summary

New wind slabs will form on Saturday on east and north aspects. These new slabs will likely be limited in size but reactive to rider traffic as a result of the faceted and wind effected surfaces they will form above.

A weak layer of feathery surface hoar may be found around 30 to 50 cm deep. It is most likely found in sheltered terrain features in the lower alpine and treeline, or open features below treeline (e.g., cut blocks). Although avalanche activity hasn't been prominent on this layer, it has been reactive in snowpack tests.

Sugary faceted grains may be found around the early-December melt-freeze crust 80 to 150 cm deep. The layer is most prevalent around 1700 m to 2200 m but could exist at lower and higher elevations for sections of the region. This layer is spatially variable, with many areas showing good bonding to the crust whereas other areas showing concern. This layer has recently been most reactive where it remains shallower than about 100 cm.

Terrain and Travel

  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.

Regioni coperte