Bollettino valanghe

Lizard-Flathead

Dec 26, 2017Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Wed
Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

Frigid temperatures have preserved the low density snow, but be cautious in areas where the snow has settled into a slab.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Expect wind slabs at higher elevations where wind has formed pockets of hard snow on the downwind sides of ridges and gullies.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–2
    A layer of surface hoar buried 50-70 cm below the surface has the potential to produce surprising avalanches. Triggering this layer is most likely in on steep sheltered slopes at treeline and below.

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

TUESDAY: Mostly sunny, moderate west winds, treeline temperatures around -20 C.WEDNESDAY: Mix of sun and cloud, moderate west winds, treeline temperatures around -17 C.THURSDAY: Cloudy with flurries starting in the afternoon, strong west winds, treeline temperatures around -15 C.

Avalanche Summary

Avalanche activity has quieted down as the cold weather sets in, although there have been some isolated reports of whumpfs at small avalanches failing on the mid-December surface hoar layer at lower elevations (e.g. see this Mountain Information Network report). The current forecasters' blog has additional advice on managing the current conditions (click here).

Snowpack Summary

Cold temperatures are preserving 50 to 70 cm of fresh snow from the past week. The snow has been deposited into harder wind slabs in exposed terrain, but remains low density in sheltered areas. The main question in the snowpack surrounds the mid-December layer sitting beneath the new snow. The layer includes crusts on south and west facing slopes and large feathery surface hoar crystals in sheltered terrain at and below treeline. The distribution of the layer, as well as the properties of the snow above it, is variable. The most suspect areas are where the wind has formed a stiff slab above this layer and on slopes with preserved surface hoar. The lower snowpack is generally well settled with a thick prominent crust that was buried near the end of November.

Regioni coperte