Bollettino valanghe

South Coast Inland

Apr 2 – 3, 2022Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Mon
Tue
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato

In sintesi

The new snowfall with moderate to strong wind is expected to form new wind slabs in exposed terrain at higher elevations. 

Solar-triggered wet loose avalanches are possible in the afternoon if the sky clears and the sun is strong. 

Problemi valanghivi

  • Wind Slabs

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

    New snowfall with moderate to strong southwest wind is expected to form reactive new wind slabs on Sunday. These may be touchy where they overlie a firm crust. 

  • Loose Wet

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

    Rain at lower elevations on Sunday morning will increase the likelihood of human-triggered wet loose avalanches.

    If the sun makes an appearance Sunday afternoon, solar-triggered wet loose avalanches should be expected on steep sun-exposed slopes.

Confidence

Low - Uncertainty is due to the timing, track, & intensity of the incoming weather system. Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

Stormy conditions are expected between Saturday night and early Tuesday expect for a brief period late Sunday afternoon when a break between systems is expected. Snowfall amounts are uncertain with weather models showing substantial variability. 

Saturday Night: Snowfall 3-6 cm, moderate to strong SW wind, freezing level low around 1000 m. 

Sunday: Snowfall 5-20 cm, sunny breaks in the late-afternoon, moderate to strong SW wind, freezing level high around 1500 m. 

Sunday night and Monday: Snowfall 15-30 cm, strong SW wind, freezing level high around 1400 m. 

Tuesday: Lingering flurries in the morning, sunny breaks in the afternoon, light to moderate W wind, freezing level high around 1300 m.

Avalanche Summary

Early reports from Saturday include a skier-triggered size 1 wind slab on a northeast aspect at 2450 m which had an average thickness of 25 cm and slid on a melt-freeze crust. 

On Friday, a ski cut in the north of the region triggered a size 1 wind slab on a northeast aspect at around 2200 m elevation which was 15-20 cm thick. In the Coquihalla area, two natural cornice releases were reported on northwest aspects and a size 1 solar-triggered loose dry avalanche was observed in the alpine. 

Snowpack Summary

The new storm snow will continue to bury a strong, supportive crust which extends to mountain top on solar aspects and to around 2200 m on northerly aspects. Strong southwest wind will be redistributing the new storm snow in exposed high elevation terrain forming touchy wind slabs.

The rest of the upper snowpack consists of a number of crust/facet/surface hoar interfaces buried in March that seem to have bonded well during the recent warm weather. 

The middle and lower snowpack are generally strong and well bonded. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Even brief periods of direct sun could produce natural avalanches.
  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.

Regioni coperte