Avalanche forecast

Northwest Coastal

Mar 21 – 22, 2024Avalanche Canada
View on map
Archived · expired 3 years ago

Avalanche danger

Sat
Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

A gradual cooling and overnight recovery should decrease the likelihood of avalanches.

Uncertainty remains on how quickly the persistent slabs will gain strength.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3.5

    Cooling temperatures will decrease the likelihood of triggering persistent slabs. Uncertainty remains on how quickly these slabs will gain strength. Meanwhile, keep using caution, especially on shallow rocky alpine terrain.

Terrain and Travel Advice

  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Confidence

Moderate

Avalanche Summary

On Wednesday, a few persistent slab avalanches (up to size 3) were observed on alpine south-facing slopes, probably triggered by daytime warming. Skier-triggered avalanches (size 2) also occurred in shallow rocky areas where the upper slab stepped down to the persistent slab. Small natural wet avalanches were also reported from steep solar slopes. Debris from the past widespread avalanche cycle are still visible throughout the region.

Snowpack Summary

A widespread melt-freeze crust exists on the surface in most areas. The frozen surface may soften throughout the day at lower elevations and south-facing slopes. Dry powder snow can still exist on true north-facing alpine slopes. A weak layer of surface hoar is developing in sheltered terrain at treeline and above. At lower elevations, snowpack was isothermal over the last few days.

Various weak layers, including crusts, facets, and/or surface hoar exist approximately 90 and 180 cm below the surface.

Weather Summary

Thursday Night

Clear with cloudy periods. 10 to 20 km/h southeast ridegtop wind. Treeline temperature -5 °C. Freezing level lowering to valley bottom.

Friday

Sunny. 20 to 30 km/h southeast ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1200 m. Overnight refreeze expected.

Saturday

Sunny. 30 to 50 km/h northeast ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1200 m. Overnight refreeze expected.

Sunday

Sunny. 20 to 30 km/h southeast ridgetop wind. Treeline temperature -1 °C. Freezing level rising to 1800 m. Overnight refreeze expected.

More details can be found in the Mountain Weather Forecast.

Regions covered