Bollettino valanghe

Lizard-Flathead

Dec 14, 2018Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 8 years ago

Pericolo valanghe

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

In sintesi

A Special Public Avalanche Warning is in effect for this region. Expected warm and sunny weather on Friday may have a destabilizing effect on the snowpack.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2
    Recent new snow has not bonded well to old surfaces. Avalanches are likely in steep and/or wind-affected terrain.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–2
    The weak structure of our lower snowpack is being tested by loading from snowfall and wind. Be especially cautious around alpine areas that form deep wind deposits. Storm slab releases that 'step down' could produce very large avalanches.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

THURSDAY NIGHT: Light snow, 2-4 cm.FRIDAY: Sunny. Strong southwesterly winds. Freezing level around 1800 m. Light snow Friday night.SATURDAY: A mix of sun and cloud. Winds becoming light to moderate southwesterly. Freezing level around 900 m.SUNDAY: Flurries. Freezing level rising to around 1800 m. Moderate or strong southwesterly winds.

Avalanche Summary

Reports from the Fernie and Corbin areas on Wednesday showed numerous storm slab releases, both natural and explosives-triggered. Slabs ranged from 20-80 cm in depth, depending on wind effect, with sizes generally from size 1.5-2. Size 2 would be classified as 'large'. These all occurred from about 1700-2000 metres and were focused on north to east aspects due to strong southwest winds.Another recent notable avalanche was a size 2 human triggered avalanche on December 2nd in Cornice Bowl north of Fernie. It occurred on a northwest facing feature at 2300 m and ran on a crust layer. There are good photos in this MIN report.

Snowpack Summary

Around 40 cm of new snow has fallen in this region. The new snow has buried an old snow surface that was noted earlier in the week for a cover of large, weak surface hoar crystals as well as hard wind slab and some sun crusts. Beneath the new snow and old surface, the snowpack has been stuck in early season conditions, hovering at roughly 100 cm of depth in alpine areas and much less at lower elevations. See the snow profile in our field team's MIN report for a visual representation of the pre-storm snowpack here. Aside from storm slabs now blanketing the surface, a primary concern is the combination of weak facets and crusts in the bottom half of the snowpack. The crust is most prevalent at and above treeline and is likely most problematic on north-facing features, especially those that are large and planar in nature. A layer of large surface hoar can also be found at similar depths in some areas, as found in a recent MIN report here.

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