Avalanche forecast

Northwest Coastal

Feb 14 – 15, 2015Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map

Highlights

During recent storms freezing levels have varied significantly throughout the region. Conditions are highly variable. Pay close attention to conditions that change with elevation, aspect and geographic location.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Recent storm accumulations may still be sensitive to human triggering, particularly in the north of the region in higher, wind-exposed terrain. Storm slabs may take extra time to strengthen due to underlying surface hoar.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Forecast warming and sunny breaks will increase the likelihood of loose wet and wet slab avalanches. Wet avalanches can be pushy and entrain mass quickly.

Confidence

Fair - Due to the number of field observations

Weather Forecast

A ridge of high pressure will develop and bring mainly clear skies for the forecast period. Sunday: Light snowfall in the morning and then clearing throughout the day / Moderate to strong northwest winds / Freezing level at about 1200m    Monday: Mix of sun and cloud / Moderate northwest winds / Freezing level at 1200m    Tuesday: Mix of sun and cloud / Light northwest winds / Freezing level at 2500m

Avalanche Summary

Wet loose and wet slab avalanche activity to size 2.5 was observed in the south of the region in the last few days. If warm temperatures persist, there is ongoing potential for this type of activity to continue.

Snowpack Summary

In the Terrace area, warming and subsequent refreezing has created a hard melt-freeze crust which extends up to about 1800m. This melt-freeze crust is adding considerable strength to the snowpack, although warming throughout the day will weaken this crust allowing for surface avalanches to fail more easily. About 20 or 30cm below the surface you may find weak surface hoar which was buried on February 10th. It is unclear if recent warming has destroyed this potentially weak layer. I'd dig down and test for this layer, especially at upper elevations where colder temperatures may have allowed for this weakness to persist. In general, the mid and lower snowpack are strong and well-settled. Further north in the region, the freezing level is reported to have hovered around 1300m during recent storms. In these areas, wind and storm slabs are a concern and deeper persistent weaknesses are more likely to exist.

Regions covered