It doesn't matter if you ski resorts or backcountry, there's no such thing as a completely controlled mountain environment. Even inbounds, avalanche control can only reduce the number of avalanches and is never completely effective. So take charge of your destiny and develop your own microclimate forecast to determine go or no-go days and what terrain to ski whether on- or off-piste.
Every region, cirque, canyon, bowl, and drainage needs its own microclimate forecast. Start with avalanche forecasting centers, ski patrols, guide services, and backcountry travelers who've recently spent time in the mountains or region you're considering. Then combine their information with your own visual and physical assessment based on the weather, new snow, wind, increasing temperature, and rainfall, to create your own real-time microclimate forecast.
Here’s how to do it.
Often, you can predict tomorrow's avalanche by understanding what's on the ground before the next storm. If the old snowpack is faceted (sugary/granular) or rotten and feels like graphite or ball bearings when rubbed between your gloves, it won't support new snow or wind-deposited snow—even on slopes less than 30 degrees in some cases. Also, snow that inconsistently supports your weight is a sign of weakness. New snow doesn't adhere well to slick surfaces, sun crust, or wind-smoothed snow. Surface hoar (upright crystals that look like feathers) and graupel (snow pellets) are a nightmare.
What Causes Avalanches?
- The weight of new snow accumulation
- Wind-deposited snow loading up
- Snow crystals changing and decreasing stability
- Surface tension developing from wind buffing and temperature swings
- Warming temperatures and rain
What Topography, Terrain, and Zones Produce Avalanches?
(See "How to identify terrain hazards" in Steep Life Protocols: Prioritizing Risk)
- Concave: Chutes, bowls, hourglasses, and other places where snow sloughs and pools in from all sides are also collection zones for wind-blown snow. Concavity funnels snow into a greater mass, multiplying the power of moving snow (like splitting an atom).
- Convex: Like skiing over a massive bowling ball, where gravity plays a much bigger role due to weight vs. angle.
- Unsupported slopes: Slopes hanging over cliffs, rocks, road cuts, etc., have less structural value and slide more often. Gradual dissipation slopes have better stacked structural value from the bottom up.
- Terrain traps: U or V-shaped terrain like streambeds, canyons, gullies, or abrupt steep to flats with a high probability of deep burials.
Get a Baseline Assessment
- Check avalanche reports, view mountain webcams, call ski patrol and the Department of Transportation, and get information from locals regarding snow surface and stability.
- When driving or flying into the mountains, use every vantage point possible to look for natural avalanches that have occurred in the last three days and, if any, the aspects and elevations where they occurred.
- Walk on unbroken snow to see if it supports you. Dig down to see if new snow is adhering to old snow. If your car has more than a foot of fresh storm snow, slam your arm into it and see if it shoots cracks in multiple directions and slides easily off one of the layers. Look for shooting cracks on rooftops indicating fracture line propagation.
- Snow pits are a focal point for snow stability, but you can gather much information in the parking lot, at the top of the chairlift, on the boot pack, and traversing the ridgeline, before even considering getting on slope to dig a snow pit.
- Slam your ski or arm into snow mushrooms capping stumps and rocks and stomp on tiny unsupported slopes to see if it sends shooting cracks in multiple directions – a huge red flag.
Maintain Visual and Physical Forecasting
- Conduct a ski cut to a safe zone before you get too far down the slope. Smart skiers stay up on ridges and high points. Be an apex powder predator.
- Dig hasty pits close to safe zones at various elevations and aspects to keep checking snowpack. The reason that you didn't commit to the convex bowl on the first run is the same reason you don't commit to it on the second run.
- Great skiers always visually observe the quality of the snow surface, know how direct and fast they can ski before dropping, and select the correct terrain based on snow surface and stability conditions to avoid avalanches. They don't just give themselves to the mountains. It's 25 percent ability, 25 percent observations, and 50 percent region/route/line selection that helps you mitigate risk and avoid avalanches.
Be safe. Skiing is life!
Dean Cummings is a professional big mountain skier and mountaineer, Alaska heli-ski pioneer, product engineer, award-winning outdoor educator, and World Extreme Skiing Champion.
(Photos from top: Josh Cooley, Eric Layton)
Stay tuned as Cummings sheds light on various Steep Life Protocol topics throughout the winter.