Bollettino valanghe

Lizard-Flathead

Dec 28 – 29, 2018Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 8 years ago

Pericolo valanghe

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

In sintesi

Rising freezing levels and increased wind will accompany snowfall. If more than 20 cm snowfall accumulates, the avalanche hazard will rise to CONSIDERABLE.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Winds are redistributing snow and slabs are forming in wind-loaded terrain.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–3
    60-110 cm of snow sits on a weak layer consisting primarily of facets (sugary snow). Winds have redistributed recent snow and slabs may be more reactive in wind-loaded areas.

Confidence

Low - Freezing levels are uncertain

Weather Forecast

FRIDAY NIGHT: Cloudy with isolated flurries, up to 10 cm accumulation. Light to moderate southwest wind. Alpine low of -12C.SATURDAY: Flurries, 5-15 cm accumulation. Moderate southwest wind gusting strong to extreme. Alpine high -4, freezing level rising above 1400 m.SUNDAY: Mix of sun and cloud with scattered flurries, trace to 5 cm accumulation. Light northwest wind gusting moderate to strong. Freezing level dropping to valley bottom, alpine high -3C.MONDAY: Mix of sun and cloud. Light northwest wind with occasional moderate gusts. Alpine low -15C.

Avalanche Summary

Small (size 1) wind slabs have been reactive to skier traffic in the region.A great MIN report from Corbin on Thursday identifies a few slabs initiating in thin, rocky areas on a south aspect. Check out the report here.Over the last weekend, the persistent weak layer was active, explosives triggered avalanches to size 2.5 and a cornice triggered a size 2 avalanche. Skier traffic was also able to trigger wind slab avalanches to size 2. Though avalanche activity on this layer has slowed, avalanches failing on this layer have the potential to be large and destructive.

Snowpack Summary

Around 20 cm fresh snowfall accumulated through the week has been redistributed around lee areas at treeline and alpine elevations. In total, 60-110 cm of snowfall through December has formed a slab that sits on a persistent weak layer that formed in early December. This layer mostly consists of facets (sugary snow) with some isolated areas also containing small surface hoar (feathery crystals). This overlies several other weak layers observed in the lower snowpack such as crusts and facets that formed in late October/early November. With this weak basal snowpack, it is likely that an avalanche triggered on the persistent slab would step down to these lower layers, resulting in a full depth avalanche.

Regioni coperte