Bulletin d’avalanche

Northwest Inland

Apr 16 – 17, 2023Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Fresh wind slabs reactive to human triggers may be found on lee features at treeline and above.

Avoid steep, rocky, and wind affected areas where triggering slabs are more likely.

Problèmes avalancheux

  • Wind Slabs

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

    Forecast snow and southerly wind may form fresh wind slabs on lee features at treeline and above.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–1.5

    Expect wet loose avalanches to begin releasing naturally when the sun heats up the recent snow.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported on Saturday. However, observations are very limited during this time of year.

A naturally triggered size 2 wind slab was reported on a north aspect in the alpine in the Ashman zone on Thursday. See MIN.

A naturally triggered size 2.5 wind slab was reported on a northeast aspect in the alpine in Seaton Basin on Wednesday. See MIN.

Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Snowpack Summary

20-40 cm of snow last week was redistributed into wind slabs on northerly aspects by south winds. The recent snow sits over wind-affected surfaces or a crust on south-facing slopes.

A weak layer buried in late March is down 30-40cm and exists as surface hoar and facets on north facing slopes and a crust elsewhere. It has produced recent test results and may be reactive to human triggers in isolated locations where the layer is well preserved and has a cohesive overlying slab. See MIN.

The middle of the snowpack is strong and contains numerous hard crusts. Near the ground, weak faceted crystals exist. There hasn't been avalanche activity on this layer recently, but it remains on our radar as it may become active with abrupt changes to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged warming.

Weather Summary

Sunday Night

Partly cloudy with flurries; 0-20 cm / 30 km/h southwest ridgetop wind / Temperature at treeline around -8 C / Freezing level valley bottom

Monday

Mix of sun and cloud / 10 km/h west ridgetop wind / Temperature at treeline around -5 C / Freezing level 1100 m

Tuesday

Mix of sun and cloud / 10 km/h southwest ridgetop wind / Temperature at treeline around -4 C / Freezing level 1300 m

Wednesday

Mix of sun and cloud / 20 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1500 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Cornice failure may trigger large avalanches.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Régions couvertes