Avalanche forecast

South Columbia

Mar 20 – 21, 2015Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Sun
Mon
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable
Open full map

Highlights

Snow, rain and strong wind combined with buried weak layers make the perfect recipe for avalanches. Check out the new Forecasters Blog @ avalanche.ca.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–5
    Touchy storm slabs continue to build and sit over a weakness from mid-February that seems to be stubborn. However; slabs failing on this layer will have larger destructive potential.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Steady rain and warming at lower elevations will saturate and weaken the snowpack. Overhead hazards like cornices are weak and could trigger slabs from slopes below.

Confidence

Good

Weather Forecast

Is spring the new winter? Waves of precipitation will continue overnight Friday and into Saturday. Saturday will see precipitation amounts 5-15 mm, ridgetop winds moderate from the SW and freezing levels 1500-1700 m. A dry day with a mix of sun and cloud is forecast on Sunday as the Pacific ridge crosses the province. Monday will see somewhat cooler temperatures with freezing levels near 1100 m and light precipitation 3-10 mm. Unsettled conditions will continue as a series of fronts and ridges move across the region next week.

Avalanche Summary

On Thursday, numerous size 1-2 storm slabs and loose dry avalanches up to 1.5 were reported. Wednesday, several natural slab avalanches and skier triggered avalanches up to size 2 were reported. Most of these avalanches failed on north- easterly aspects above 2000 m. With forecast snow, rain and wind, natural avalanche activity is expected to continue tomorrow.

Snowpack Summary

At higher elevations, up to 20-50 cm of snow sits over a plethora of old surfaces including wind affected surfaces, and/or old wind slabs and crusts which were buried mid-March. Previous strong winds have redistributed new snow into wind slabs on leeward terrain features and lower elevations (below 2000 m) are sporting spring-like, melt-freeze conditions. Digging deeper (40-70 cm below the surface) sits the mid-February facet/ crust interface. This interface has not been as reactive in the South unlike regions to the North. However, it is alive and well in test profiles. It may just require additional load and/ or a change in slab properties before it reaches threshold and becomes reactive. The late-Jan crust/surface hoar layer (around 1m deep) and the mid-January surface hoar (around 1.5m deep) have been dormant for several weeks.

Regions covered