Basic avalanche resources for Western Canada by Canada West Mountain School

1. Avalanche Awareness
Presented by
Canada West Mountain School

2. Avalanche Hazard
Triangle
?
Avalanche
Hazard!
People or property
?

3. Loose Snow Avalanches

6. Photo: Jasper National Park
Photo: Mark Austin

7. Failure of slab through
additional weight
Failure in
tensile
strength
Local Shear
failure
Wind Increased load
on lee slope
Failure in
tensile
strength
Shear failure

8. Start Zone: Critical Angles
Angles are only relevant to
terrain in starting zones!
60-90
degrees Constant sluffs;
Large slabs
uncommon 25-45 includes a lot of
common terrain!
90
45-60 Frequent small avalanches;
degrees infrequent large slabs
25-45
60 degrees
Largest slabs;
Frequent avalanches
45
10-25
Dry slabs
degrees
are uncommon;
25 Wet avalanches can
occur occasionally

9. Avalanche “Crown” approx. 2m
in depth. Size 3 avalanche, 28
degree slope at fracture line
Dec 27, 2008

10. Snowpack Structure
Understand the snow pack if you are in Avi terrain
• Weather creates the snowpack
know the weather history
• Terrain effects modify the snowpack
pay attention to changes in terrain
• The snowpack will change over time
constantly re-asses snow conditions
• Have a visual picture of the snowpack

11. Information gathering
for backcountry
winter travellers

12. Where do we get our info??
• Public Avalanche Bulletins
• Weather offices, websites, etc
• Highways departments
• Parks offices
• Local guides
• Ski patrols
• Local outdoor stores
• Clubs and members
• Information from prior trips
• Online forums
• Friends, people on the trail

13. Avalanche Bulletins
• Canadian Avalanche Center Bulletin
• Whistler-Blackcomb Avalanche Advisory
• North Shore Avalanche Advisory
• US Avalanche resources (avalanche.org)
• European Bulletins

14. Weather information
• Environment Canada Weather
– Public Text forecast
– Satellite imagery
• Whistler-Blackcomb Alpine
• Mount Seymour Alpine
• Western Washington Univ.
• Mountain Weather Services
• Ski Resort Forecasts (snow-forecast.com)

15. Highways Departments
• Highways Webcams (and others)
• DriveBC.com

16. Local Guides
• Mountain Conditions Report (MCR)
• ACMG
• Canada West Mountain School

17. Other resources
• National Parks offices
• Outdoor stores
• Online forums
– Telemarktips.com
– CAA Forum
• Clubs and members
• Information from prior trips
• Friends, people on the trail

18. Anniversary Glacier Avalanche and historical run-outs – Jan. 2008

19. Flute Bowl, Whistler Mountain – May 2008