Avalanche forecast

Banff Yoho Kootenay

Feb 5 – 6, 2015Parks Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map

Highlights

The great conditions will continue until mid-day Thursday, but then it all changes. An avalanche cycle will be in full force by Friday with up to 40 cm expected, freezing levels to 2000m and winds exceeding 110 km/hr. Head for the trees!

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    Windslabs exist in isolated areas at higher elevations, and this problem will increase late in the day on Thursday as the storm arrives.  The bond to the surface under the windslabs is suspicious, so watch out as this new storm changes conditions.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3
    The base of the snowpack remains weak due to basal depth hoar/facets. Continue to avoid large open slopes with shallow snow and rocks, as this is the kind of place where this deep weakness could be triggered.

Weather Forecast

The weather is changing as a strong system moves into the area embedded in a westerly flow. Expect 5-10 cm Thursday, 15-25 Friday, and 10 cm on Saturday. Significant warming and winds accompany this system, with freezing levels to 2000 m on Friday and SW wind exceeding 100 km/hr.  This may not come true, as the models disagree on snowfall amounts.

Snowpack Summary

35-50 cm of recent storm snow sits on a crust from January 30, and in isolated locations (east of the divide) has been blown into windslabs. Over the next few days, as the next storm begins to add load, this bond to the Jan 30 interface will be critical. Expect windslabs by Thursday, with human triggered and natural avalanches likely by Friday.

Avalanche Summary

One natural size 2 avalanche was observed on Mt. Redoubt near Lake Louise, approximately 60 m wide and failing on the ground level depth hoar.  Good backcountry observations were made from Sunshine Village and the Brewster Creek area, and no new avalanches were observed here.

Confidence

Intensity of incoming weather systems is uncertain on Friday

Regions covered