Bulletin d’avalanche

Kootenay Boundary

Mar 4 – 5, 2023Avalanche Canada
Voir sur la carte
Archivé · expiré 4 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Carefully assess recent snowfall amounts as you move through terrain. Convective flurries can result in localized intense precipitation and increased hazard.

Storm slabs could become more reactive is the sun comes out.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2.5

    Avalanche activity is tapering off in the region but storm slabs will likely remain sensitive to rider traffic. The largest and most reactive slabs will likely be found on north and east aspects at treeline and above.

    Previous storm snow rests over surface hoar and a crust. It is possible that storm slabs could run on this layer resulting in a larger and more destructive avalanche.

    If the sun comes out storm slab reactivity could increase.

Confidence

Moderate

Avalanche Summary

On Thursday less avalanche activity was reported than the previous day. One size 1 natural storm slab and one size one skier controlled storm slab avalanche was reported on a east aspect at treeline in the Rossland range.

On Wednesday several skier triggered avalanches up to size 2 were reported. These avalanches were generally on easterly aspects at treeline but some occurred on north aspects as well. These avalanches involved surface hoar layers from February and January.

Snowpack Summary

Previous storm totals average 30-50 cm of low density snow. Expect deeper deposits on north and east facing slopes, from west and southerly winds. This storm snow sits over heavily wind affected surfaces at all elevations.

Check out this MIN for a summary of conditions at Kootenay Pass.A

A layer of surface hoar can be found on shaded slopes, and a sun crust on sun affected slopes buried 30-70 cm deep. Another layer from January is buried up to 50 cm below this. These layers has been noted as a failure plane for some avalanche activity.

Otherwise, the snowpack is generally well consolidated and bonding. The lower snowpack includes a layer of weak sugary crystals near the ground. These facets are slowly gaining strength and have not produced recent avalanche activity. We continue to track the layer and watch for any signs that it could wake up and produce very large avalanches.

Weather Summary

Friday Night

Mostly cloudy with flurries bringing up to 10 cm of new snow. Light to moderate southwest winds and a low of -10°C at 1800 m.

Saturday

Clearing in the afternoon with the possibility of convective flurries bringing up to 5 cm of new snow. Light southerly winds and a high of -5°C at 1800 m.

Sunday

A mix of sun and cloud with no new snow expected. Light southeast winds and a high of -7°C at 1800 m.

Monday

A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Light southerly winds and a high of -5°C at 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Avoid freshly wind loaded terrain features.
  • Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
  • Avoid exposure to steep sun exposed slopes.

Régions couvertes