Avalanche safety the science of snowpacks
- Wind is one of the most important factors influencing the stability of a snowpack, and its likelihood of sliding.
- Simply put, wind has the ability to redistribute snow from its original resting place. This often moves snow from ridgelines to lee slopes, or creates overhangs called cornices which can fall and trigger avalanches. Cornices can often break further back than expected and should be given a wide birth when heading into the backcountry.
Terrain plays a huge part in the stability of snowpacks and major things to factor in are the slope altitude, aspect and incline.
- Altitude will affect the type of precipitation falling on the slopes.
- Aspect can influence the amount of sun a slope receives, and therefore the likelihood of snowmelt. Generally speaking north-facing slopes are the most likely to avalanche during the middle of winter whilst south-facing slopes become more dangerous in the spring and through sunny days as the sun begins to rise higher in the sky.
- Slope incline can be attributed as one of the most important factors to consider when looking at avalanche risk. Whilst slides have been reported on slopes anywhere from 25-60 degree angles, the most dangerous are those between 30-45 degrees.
Neil's Top Tips for Avalanche Safety
- Check the avalanche forecast. Most avalanche fatalities happen when the risk is 3 out of 5 – just because it’s a middle number doesn’t mean it’s safe!
- Look for signs of any other avalanche activity – particularly on slopes of a similar aspect, altitude and gradient. This can help you make an informed decision.
- Just because you have safety equipment doesn’t mean you’re safe. Regularly practice single and multiple transceiver searches and a good digging technique.
- Talk to the local ski patrol – they will always offer you sound advice.
- Always plan your route and identify any hazards or terrain traps before you set off. How you approach a slope tactically can help you manage the risks more effectively.
- Never ski or ride alone when venturing off-piste.
- If you have a sense of unease or a bad feeling in your gut, listen to it and turn back!