Our guide to reading an avalanche forecast covers the structure: the danger level, the aspects, the elevation bands. This article goes one layer deeper, into the part that actually shapes your route — the avalanche problem.
The danger level tells you how much hazard there is. The problem tells you what kind, and that is what determines where you can go and how you should behave when you get there. Two days at level 3 with different problems are two completely different days. If the levels themselves are still fuzzy, we unpacked what “considerable” really means.
Wind slab
What it is. Wind transports snow and deposits it as a cohesive slab, typically on lee slopes and behind terrain features.
Why it catches people. It is often localised and often obvious in hindsight — a firmer, hollow-sounding, slightly rounded surface where softer snow should be. It forms quickly, sometimes within hours of a wind event, and it can sit next to perfectly stable snow.
What it changes. Wind direction becomes the first question of the day. You are looking for loaded lee slopes, cross-loaded gullies and pillows behind ridgelines — and you can often ride a good day by simply avoiding the aspects that were loaded.
Persistent slab
What it is. A cohesive slab sitting over a weak layer that has been buried for a long time and refuses to heal.
Why it catches people. It is the problem that defeats intuition. The snow can feel fine, the surface can behave normally, days can pass without incident — and then a slope releases on a layer that was buried weeks ago. Ski tracks on a slope prove nothing about the next person to cross it.
What it changes. Everything. Persistent problems demand conservative terrain choices for extended periods, not just for a day, and they do not respond to the “it has been fine so far” logic that works reasonably well for other problems. This is the problem that most rewards patience.
Wet snow
What it is. Snow losing strength as liquid water moves through it — from warming, sun or rain.
Why it catches people. It is a timing problem rather than a terrain problem. The same slope can be entirely reasonable in the morning and unreasonable by early afternoon.
What it changes. The clock becomes a safety instrument. Early starts, an honest turnaround time, and paying attention to aspects as the sun moves round. If your boots are sinking in and snow is balling up, the day has moved on without you.
Loose snow, dry and wet
What it is. Snow without cohesion, releasing from a point and fanning out — sluff, in its dry form.
Why it catches people. Individually smaller than slab avalanches, and easy to dismiss. The danger is usually what it does to you rather than what it is: knocking you off balance in steep terrain, carrying you over a cliff, or burying you in a terrain trap where a modest volume becomes a deep burial.
What it changes. Sluff management on steep descents, and honest thinking about what is below you. Consequence, not size.
Glide avalanches
What it is. The entire snowpack sliding slowly over the ground, usually on smooth surfaces like grass or rock slabs, often marked by opening glide cracks.
Why it catches people. They are close to unpredictable in timing. A crack can sit open for weeks and release at any moment, day or night, warm or cold.
What it changes. Not a problem you manage with technique — you manage it with distance. Do not linger under glide cracks, and do not camp, transition or regroup beneath them.
The point
When you read tomorrow’s forecast, do not stop at the number. Find the problem, its aspects and its elevation band, and then ask one question: does the route I have in mind put me on that terrain?
If it does, change the route — not your assessment of the forecast. And make sure the people you are with are carrying a shovel and probe worth having, because the plan is what keeps you off the slope and the kit is what is left if the plan fails.