Bulletin d’avalanche

North Columbia

Mar 26 – 27, 2021Avalanche Canada
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Archivé · expiré 6 years ago

Danger d’avalanche

Sun
Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Human triggered avalanches are possible. Watch for changing snow conditions when you gain elevation and transition into open wind affected terrain. 

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    While the upper snowpack is generally strong, slab avalanches are still possible on some steep terrain features. The most likely spot to find reactive slabs is where there has been recent wind loading in lee terrain. There are also some surface hoar and crust layers in the top 60 cm of the snowpack, and while none of these layers are overly concerning, they may act as sliding layers.

Confidence

High -

Weather Forecast

FRIDAY NIGHT: Scattered flurries with up to 5 cm of snow, 30-40 km/h west wind, treeline temperatures around -5 C.

SATURDAY: Mostly cloudy with scattered flurries and up to 5 cm of snow, 40-50 km/h southwest wind, freezing level up to 1600 m, treeline temperatures around -3 C.

SUNDAY: Flurries with 10-20 cm of snow, 40-60 km/h southwest wind, freezing level up to 1500 m, treeline temperatures around -4 C.

MONDAY: Another 5-10 cm of snow by the morning then mostly cloudy during the day, 30 km/h northwest wind, freezing level drops to valley bottom and treeline temperatures drop to -10 C.

Avalanche Summary

Recent avalanche activity has primarily been small (size 1-1.5) wind slab and dry loose avalanches in the top 20 cm of snow. A few larger slab 2 avalanches have been observed in steep slide paths in Glacier NP over the past few days. One notable size 3 slab avalanche was observed northeast of Revelstoke on Wednesday. The avalanche failed on the ground on a south aspect at 1600 m. While an isolated event, it is a good reminder to watch for slopes warming up in the springtime heat.

On Saturday there will be a lingering possibility to trigger storm slab, wind slab, and dry loose avalanches in the upper snowpack.

Snowpack Summary

At alpine and treeline elevations 10-20 cm of fresh snow brings totals over the last week to 40-60 cm. This sits above an interface that formed during the mid-March dry spell, which consists of a widespread crust (except on north-facing slopes above 1800 m). Overall the snow seems to be bonding well to this interface, although there have been some isolated human triggered avalanches running on the crust layer over the past few days.

Lower elevations have undergone daily melt-freeze cycles, with moist or crusty surfaces likely found up to at least 1600 m.

Terrain and Travel

  • Be careful with open slopes and convex rolls, especially in more extreme terrain.
  • Be carefull around freshly wind loaded features.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Régions couvertes