Reading Avalanche Bulletins
The avalanche bulletin is the most important piece of information available to any skier venturing beyond the piste boundary, and it is widely misread. The most common misreading involves treating the danger level as a single number that either permits or prohibits off-piste travel, when in fact the bulletin is a layered document describing specific problem types on specific aspects and elevations. A danger level of 3 on north-facing slopes above 2,200 metres with a persistent weak layer problem is an entirely different situation from a level 3 resulting from new snow on all aspects below treeline. The number matters less than the problem.
The Five-Level European Danger Scale
The European avalanche danger scale runs from 1 (Low) to 5 (Very High) and has been standardised across Austria, Switzerland, France, Germany and Italy since the 1990s. The same scale is used in North America with minor terminological differences. Each level has a defined meaning:
Level 1 (Low) indicates that the snowpack is generally stable. Triggering is only possible in isolated steep terrain with very localised weak spots, usually after a major consolidation period. Most off-piste terrain is manageable for experienced parties.
Level 2 (Limited) means the snowpack is moderately consolidated on steep slopes. Triggering is possible on specifically steep terrain, usually on particular aspects. The majority of off-piste terrain is safe for competent parties who can identify and avoid the problem aspects.
Level 3 (Considerable) is the level at which many avalanche fatalities occur, partly because it sounds manageable — 'considerable' rather than 'high' — and partly because it represents the transition between workable terrain choice and genuinely complex risk assessment. Triggering is possible on steep terrain across the problem aspects, and sometimes on less steep terrain above existing avalanche paths. This level requires meaningful terrain avoidance, not just awareness.
Level 4 (High) means triggering is likely on steep terrain, and natural releases are possible. Staying on marked pistes and avoiding any off-piste travel is the appropriate response for all but the most expert parties with very specific objectives and experience.
Level 5 (Very High) is rare — declared only a handful of times per season at most — and indicates that natural avalanche release is widespread, affecting even shallow terrain. Normal mountain travel is not appropriate.
Avalanche Problem Types
Modern bulletins from the Swiss SLF, Austria's Lawinen.report, and the French Météo-France forecasts all describe specific avalanche problems rather than simply assigning a danger level. Understanding these problem types changes how you read the bulletin fundamentally.
New snow problems develop after significant snowfall — typically more than twenty to thirty centimetres in forty-eight hours — and are usually most severe immediately after the snowfall, moderating as the snow consolidates. They affect all aspects at all elevations and are relatively predictable: the problem appears, peaks, and decays over several days. Terrain choices that avoid very steep convexities and exposed loaded faces manage this problem well.
Wind slab problems are highly spatially variable. Wind slabs — consolidated plates of windblown snow deposited on lee aspects and in terrain features — are the most common avalanche trigger in Europe. They can exist as relatively small but dangerous features on a slope that otherwise appears straightforward. Recognising wind loading visually — a chalky, dull surface in contrast to the surrounding snow's sheen, a hollow drum-like sound underfoot, or a recent break line from a small natural release — is a core skill. Bulletins specify the elevation bands and aspects where wind slab deposition has occurred.
Persistent weak layer problems are the most dangerous and least predictable of all problem types. A buried layer of faceted crystals, surface hoar, or depth hoar can persist for weeks or months beneath subsequent snowfall, remaining capable of being triggered long after the conditions that formed it have passed. The Swiss SLF and Austrian forecasters describe these layers by the date of formation when tracking them — a bulletin might warn of a 'weak layer from 15 January' that remains a concern through late February. These problems often release with little warning on slopes that have already been skied, and the remotely triggered avalanche — released by a skier on a different slope than the one that runs — becomes possible.
Wet snow problems develop in spring or during warm spells, when meltwater percolates into the snowpack and lubricates the bond between layers. The timing trigger — solar radiation and rising air temperature — makes these highly predictable: wet slides typically run in the afternoon on sun-exposed aspects. Skiing south-facing slopes before midday and retreating to north aspects or returning to the piste in the afternoon is the standard management approach.
Geographic and Temporal Structure of Bulletins
European national avalanche bulletins are typically issued once daily, around seven in the morning, with an afternoon update when conditions warrant it. The SLF bulletin for Switzerland divides the country into specific warning regions — the Bernese Oberland, the Graubünden, the Valais, the Uri Alps — and assigns a separate danger level and problem description to each. The French Météo-France bulletins cover massifs: Belledonne, Grandes Rousses, Haute Tarentaise, Mercantour. Austria's Lawinen.report operates at provincial level and is detailed by elevation band and aspect within each.
The elevation structure within a bulletin matters. A level 2 danger on slopes above 2,500 metres and level 1 below is not the same as a level 2 across all elevations. Many touring routes can be completed safely at lower elevation even when the high alpine terrain carries significant hazard, and reading the elevation bands correctly is the key to making that distinction.
The temporal validity of a bulletin is worth noting: conditions can change faster than a once-daily update captures. After heavy snowfall overnight or a rapid wind shift, a morning bulletin issued at seven may already be outdated by ten. Observing terrain and snow conditions on the ground — looking for recent natural avalanche activity, cracking snow under skis, or rapid temperature change — provides real-time data that supplements the forecast.
Using Bulletins in Practice
Checking the bulletin is only useful if the result changes your terrain choices. The practical application is to identify the problem type, the elevation and aspect where it is most pronounced, and then cross-reference that with the planned route. A persistent weak layer problem on north-facing slopes above 2,000 metres means north-facing steep slopes in that elevation band are excluded from the day's terrain menu. A wind slab problem on east and northeast aspects after yesterday's westerly wind means those aspects require careful assessment of surface texture before committing.
The 3x3 reduction method and the avalanche terrain exposure scale (ATES) provide systematic frameworks for turning bulletin information into terrain decisions. ATES classifies terrain into Simple, Challenging and Complex categories based on slope angle, terrain traps, and the consequences of a slide — a useful framework for matching the day's danger level to an appropriate terrain category.
Open the map to explore ski areas and identify which resorts provide direct links to regional avalanche forecasting services — some integrate this information directly into their resort information pages, which makes checking before each day's off-piste travel straightforward.