This is an extremely important step in the Daily Process and not one that can be fully explored here. Ahead are some critical points. To learn more, do one of our Avalanche Canada AST1 courses.
We know there are many hazards in the backcountry and avalanche danger is but one. There are more incidents in the Australian backcountry due to surface conditions than avalanches, and some of the worst result from a combination of under-estimating the conditions, over-estimating your ability to deal with them, and human behaviours (mental biases that cause flawed decision-making).
You can evaluate slopes for surface condition hazards such as ice and breakable crusts by watching the weather, especially temps, looking at slope aspects, and putting the two together. Often it is a matter of timing with conditions changing through the day due to temps and solar.
Mountain Safety Collective www.mountainsafetycollective.org reports on backcountry conditions and hazards, including avalanche forecasts, throughout the Australian season.
For reducing avalanche risk, evaluating the following factors can minimise the likelihood or consequences of triggering an avalanche. The importance of being able to rapidly assess terrain for its avalanche risk cannot be overstated as staying safe in the backcountry is all about selecting appropriate terrain for the conditions.
Slope Angle As long as there is no exposure from above, you can effectively lower avalanche risk by choosing low angled slopes – less than 30 degrees.
Slope Size The larger the slope the larger the potential slide.
Slope Shape Avalanches initiate more frequently from convex slopes. Concave slopes and planar slopes are generally safer but if sufficiently steep may still avalanche.
Orientation to Wind Slopes lee to wind can become loaded during strong wind events and develop wind slabs. Cross loading of slopes is also a major concern and learning to identify these conditions is essential as these slopes often present as the best riding.
Orientation to the sun In Australia north facing slopes are our solar aspects. On days with sunshine or high thin cloud the sun’s rays can be your friend or your foe. They may soften icy slopes after a melt freeze cycle on the one hand but on the other add weight to the snowpack and significantly increase avalanche danger as seen in 2019 in the Mt Etheridge slide (pictured above).
Supported or unsupported slopes A sufficiently dense treed slope (tight to ski through) can lower avalanche risk. Convex roll features are an example of an unsupported slope and avoiding these will lower the risk.
Terrain traps Avoid areas where terrain traps such as cliffs,creeks, gullies and benches would increase the consequences of an avalanche.
If an avalanche forecast is available (it must be provided by a qualified avalanche forecaster), you can select areas where more favourable conditions exist – for example, a west-facing line in the alpine could be a good choice if a wind slab problem is listed on east aspects.
Snow profiles and snowpack tests can evaluate the state of the snowpack. The use of these tests by recreational users can be problematic due to the difficulty of selecting safe, representative test sites and because there is significant potential for making a false assessment. Professionals are trained to use snowpack tests to rule terrain out as opposed to ruling it in. If there is any question of avalanche hazard, a better option is to choose safer terrain as described above.
