Avalanche forecast

Northwest Inland

Jan 4 – 5, 2015Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

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

Highlights

Conditions vary significantly within the region from South to North. Avalanche danger could be slightly lower than indicated in the northern half of the region due to less recent snowfall.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Strong winds have created dense or hard wind slabs in exposed lee and cross-loaded terrain, possibly at all elevations. Watch for triggering below ridge crests and terrain breaks. 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–6
    New loading from snowfall and strong winds could 'wake up' deeper persistent weaknesses and produce isolated very large avalanches.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Synopsis: We should see a brief lull in the weather on Monday before the arrival of another strong frontal system late in the day. There could be a few breaks Monday morning followed by increasing cloud and snow in the evening. Overnight Monday and through Tuesday we could see 10-20 cm of snow. Winds increase once again to strong from the S-SW. The freezing level stays at valley bottom on Monday and Tuesday with treeline temperatures around -10 to -15. Snow and winds should gradually taper off on Wednesday. An above freezing layer might also form near 2000 m.

Avalanche Summary

There are a couple recent reports of natural and rider triggered wind slabs up to size 1.5 from steep treeline features. These wind slabs have involved only the resent storm snow. Touchy wind slabs should continue to build in lee terrain over the next couple days.

Snowpack Summary

Recent winds have been highly variable with strong W-NW winds followed immediately by strong SE-NE winds. Hard and soft wind slabs should be expected on a variety of slopes in open terrain. rain was reported to almost 2000 m on New Years Day in the southern part of the region. Since then there's been around 20-50 cm of new snow. The new snow may be resting on older wind slabs or surface hoar in northern areas. Down 40-70 cm you may find another surface hoar layer, although it appears to be spotty in distribution. Near the bottom of the snowpack is a crust facet combo that was buried in mid-November. This layer is currently dormant and produces variable results in snowpack tests. I suspect it will remain sensitive to new inputs in the form of new snow and wind for the foreseeable future.

Regions covered