Avalanche forecast

South Columbia

Jan 25 – 26, 2016Avalanche Canada
View on map
Archived · expired 11 years ago

Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
Open full map

Highlights

The current conditions require restraint and conservative decision-making. Triggering the weak layer is getting more difficult but large avalanches, even from relatively low-angle slopes, remain possible. New wind slabs may also form on Tuesday.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    New wind slabs may form in leeward features on Tuesday. It may still be possible to trigger deep older wind slabs in exposed lee and cross-loaded terrain near ridge crests.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–5
    Large avalanches have been failing on a buried persistent weak layer down 40-80 cm. This problem will likely remain sensitive to human triggers for the next few days.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

A weak storm pulse is expected to bring 5-10cm of new snowfall to the region on Tuesday. Freezing levels are expected to be around 1500m and alpine winds are forecast to be moderate to strong from the southwest. A mix of sun and cloud is expected for Wednesday with freezing levels reaching around 1500m and light to moderate southwest winds in the alpine. A more substantial storm front is expected to reach the region on Wednesday night or Thursday morning. 15-25cm of snowfall is currently being forecast with freezing levels around 1700m and strong southwest winds.

Avalanche Summary

Numerous slab avalanches up to size 3 were reported over the weekend. Most of the natural avalanche activity occurred on Friday and Saturday but several were still reported on Sunday. A large number of skier triggered avalanches were also reported. Many of these failed at treeline and below on buried surface hoar down 30-60 cm. Many of these were triggered remotely, highlighting the volatility of the persistent slab. An increasing number of wind slabs have also been failing at alpine/ treeline elevations, and also running on surface hoar. While the natural activity tapered off since Saturday, the persistent slab is expected to remain reactive to human triggering for several more days. New wind slabs may form on Tuesday with the progression of the weak storm system.

Snowpack Summary

Recent snowfall and strong winds have created some storm slabs but reactive wind slabs on features lee to the southerly winds seems to be the bigger concern in the upper snowpack. This has added additional load and stress to an already touchy persistent slab. This 40-90 cm thick persistent slab overlies a variety of surfaces including large surface hoar, sun crusts, rime crusts and facets. The slab is ripe for human and natural triggers and is especially touchy at and below treeline. The mid and lower snowpack are generally well settled and strong.

Regions covered