Bulletin d’avalanche

South Rockies

Apr 11 – 12, 2019Avalanche Canada
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Archivé · expiré 7 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

The region has received variable storm snow amounts. In areas where 15 cm or more fell you may find reactive wind slabs on northerly aspects in the alpine. Daytime warming and periods of sun will likely trigger loose wet avalanches on solar aspects.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Wind slabs may be reactive to human triggering especially on North facing slopes in the alpine.
  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    The likelihood of loose avalanches increases as temperatures warm through the day and/or if the sun comes out for a period of time. Loose wet avalanches are more likely in areas with fresh snow.

Confidence

Low - Due to the number and quality of field observations

Weather Forecast

An unstable airmass is mostly responsible for the continued spring-like and (unsettled) weather conditions. Flurries and periods of cloud and sunshine will persist through the forecast period. The convective nature and model disagreement makes it very hard to nail down snowfall amounts.THURSDAY NIGHT: Some cloud cover with possible flurries. FRIDAY: Mix of sun and cloud with a chance of flurries in the afternoon. Alpine temperatures -1 and freezing levels 2100 m. Ridgetop winds light-moderate from the southwest.SATURDAY: Cloudy with snow amounts 5-10 cm. Alpine temperatures near -3 and freezing levels 1900 m. Ridgetop winds strong from the West.SUNDAY: A mix of sun and cloud accompanied by gusty winds. Alpine temperatures near -5 and freezing levels 1700 m.

Avalanche Summary

No new avalanche activity reported from this region on Thursday, the following is from the Lizard Range:On Thursday, explosive control was able to initiate a few loose dry avalanches up to size 1.5 which failed in the recent storm snow. In the afternoon skier controlled loose wet avalanches were easily triggered at treeline and below up to size 1.5 on sunny aspects. No natural avalanche activity was reported and no new avalanches were noted in alpine elevations. Its important to make observations with changing conditions through the day and know when to pull back or dive into your line. If you're unsure, its best to have a conservative approach.

Snowpack Summary

15 cm overnight brings 20-35 cm of recent accumulated snow since the last weekend which sits above a supportive crust at treeline and in the alpine. During the heat of the day, especially under direct sun, the snow surface becomes moist or wet almost everywhere. The exception being high elevation north facing features. Steep, north facing, alpine terrain may still hold a cold, dry, snowpack where isolated reactive wind slabs may exist and a well settled slab rests on weak facets (sugary snow). Although unlikely, human triggering of persistent slabs on this layer may still be possible, especially in rocky alpine terrain with a shallow or highly variable depth snowpack.Below treeline the snowpack is becoming isothermal.

Régions couvertes