Avalanche Forecast

Issued: Jan 9th, 2017 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Wind Slabs.

william lawson, Parks Canada

Banff Yoho Kootenay.

The recent snow has created small reactive windslabs in the alpine and ideal conditions for loose snow avalanches. The main concern is in areas with significant terrain traps. Ice climbers in particular should be weary of this problem.

Summary

Weather Forecast

Another pulse is expected this evening with forecasted amount of snow averaging 4-8cm, As this moves through winds are expected to remains moderate in the alpine and then trending to light by tomorrow. Another arctic flow is approaching, by Tuesday temperatures will sink to the low -20's with beautiful clear sky's.

Snowpack Summary

10-15cm of new snow last night sits on a faceted snowpack. In the alpine the new snow has had some wind affect with small slabs developing in lees, this new slab sits on hard wind affected snow from the past week. At treeline and below the new snow remains low density and overlays a heavily faceted snowpack with little structure or support.

Avalanche Summary

Loose dry avalanches were observed in steep terrain, releasing from last nights storm snow. The southern part of the forecast region appeared to have slightly more snow and wind, Sunshine ski patrol reported numerus size 1 avalanches in areas where new wind slab exist. These avalanches were triggered by explosives and ski cuts.

Confidence

Problems

Persistent Slabs

Natural and human triggering has tapered off in recent days, but forecasters still have little confidence and feel there is a high degree of variability across the forecast region. Where winbslabs exist be especially cautious.

Use caution in lee areas. Wind loading could create slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Small windslabs and loose snow avalanches can be triggered in the recent storm snow. The main concern is in areas where significant terrain traps exist. Take extra caution when traveling around cliffs and steep gullies.

Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 10th, 2017 4:00PM