Bollettino valanghe

Northwest Coastal

Apr 4 – 5, 2017Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

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

In sintesi

New snow, wind, warming, and rain will increase the avalanche danger on Tuesday. It's a good time to stick to conservative terrain.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–3
    A weak layer from February produced several large human triggered avalanches at the end of March, and may still react in shallow areas. Heavy loads such as a storm slab avalanche or a cornice fall are also possible triggers.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–2
    20-40 cm of new snow and wind speeds exceeding 60 km/h will build very touchy storm slabs.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–2
    Rain at lower elevations will cause loose wet avalanches in steep unsupported terrain features.

Confidence

High -

Weather Forecast

TUESDAY NIGHT: 15-25 cm of snow, 60+ km/h south wind, freezing level up to 1200 m.WEDNESDAY: Another 5-15 cm of snow throughout the day, 60 km/h south wind, freezing level around 1000 m.THURSDAY: Linger flurries with another 5-10 cm, moderate southeast wind, freezing level up to 1000 m after an overnight freeze.FRIDAY: Mostly cloudy with isolated flurries, moderate southeast wind, freezing level up to 1000 m after an overnight freeze.

Avalanche Summary

On Monday, two large cornice falls were reported, one of which triggered a size 2.5 persistent slab avalanche on the February weak layer on a northeast aspect at 1600 m. Explosive control north of Stewart produced numerous size 1-2 wind slabs and cornices on north and northwest aspectsOn Wednesday, expect the new storm slabs to be touchy at higher elevations with the ongoing potential for deeper avalanches on the February weak layer.

Snowpack Summary

Strong winds and 20-40 cm of new snow will form fresh storm slabs above 1200 m. At lower elevations, rain will weaken the snow and release loose wet avalanches in steep unsupported terrain features. On shaded aspects above 1300 m, the new snow is burying 20-30 cm of old storm snow. Elsewhere, a mixture of crusts and moist snow surfaces exist from recent melt-freeze cycles. The late February persistent weak layer continues to be a concern for triggering large avalanches. This combination of crust and weak facets is now down 100-150 cm. Recent snowpack tests at the May Creek area found moderate sudden results on the layer on a east aspect around 1200 m. The layer could still be triggered by light loads in shallow weak spots.

Regioni coperte