Decoding the BERA: How to Read the Météo-France Avalanche Bulletin

01The number is the headline, not the story

To read the Météo-France avalanche bulletin (BERA), work top to bottom in one fixed order: the danger level and its elevation split, the named avalanche problems, the aspect rose, triggered versus natural releases, then the snowpack text and the trend. Then lay all of it over your own route's aspects, elevations and timing.

The BERA (Bulletin d'estimation du risque d'avalanche) is what Météo-France publishes for every French massif, and the danger number is only its first line. Almost everything that keeps you alive lives in the text and pictograms below it: which slopes, at what elevation, on what aspect, at what time of day, and whether the snow will release on its own or only under your weight.

This matters because **level 3 (Considerable) is where the largest share of fatal accidents happens*: 48% of fatal avalanche accidents in France, according to ANENA's study of fifty years of accidents. Levels 4 and 5 are rare and keep people at home; level 3 looks manageable and the sun is out, which is the trap. The bulletin tells you how* to ski a level-3 day (which aspects to avoid, where the buried weak layer lives, when warming turns the south faces dangerous), in the text most people skip.

Once you can read the BERA, you can read any European bulletin, because they all follow the European Avalanche Warning Services (EAWS) standard; the second half of this guide maps the same information onto the Italian (AINEVA), Swiss (SLF) and Spanish (AEMET) bulletins. This teaches you to read the document; it does not replace an avalanche course or your own observations.

02Where and when is the BERA published?

Météo-France publishes the BERA every day at 4 pm, from early November to mid-June, for the 35 massifs of the Alps, the Pyrenees and Corsica; each bulletin is valid until midnight the next day. It is free on meteofrance.com/meteo-montagne, in the Météo-France app and on the boards of ski areas and huts, and the raw data is released as XML and PDF. Read it the night before your tour, not at the trailhead. An out-of-date bulletin is worse than none: the snowpack has moved on.

An estimate, not a weather forecast. The full name says estimation on purpose. The BERA is a forecaster's expert judgement of avalanche danger across a whole massif. It is regional, not point-specific; it estimates likelihood and distribution, not certainty; and it describes the worst representative slope in the massif. Your slope may be less dangerous, but never assume that without evidence. Treat the BERA as the best-informed starting hypothesis, then confirm or downgrade it with what you see on the snow.

Where Snow Trace fits. Snow Trace links the official Météo-France bulletin for your massif next to the route on the map. It issues no avalanche forecast of its own and replaces neither the bulletin nor your training.

03The avalanche danger scale: five levels that are not linear

Every European bulletin — French, Italian, Swiss, Spanish, Austrian — uses the same EAWS five-level danger scale, with standard names and colours, so a skier crossing a border reads the same thing.

It is not linear. The step from 2 to 3 is much bigger than the step from 1 to 2: the chance of triggering a slab as a single skier jumps, and the terrain you can safely ski shrinks hard.

Level 1 is not safe. Low means the snowpack is generally stable, not that the consequences are. A small slide can still carry you over a cliff or into a terrain trap, and once a slab has you, the first 15 minutes decide survival.

Common mistake: reading the level as a green or red light. A level 3 on north-east slopes above 2,400 m can be a fine day on sunny, lower-angle terrain and a deadly one in the shaded steep bowl the bulletin named. The level sets the stakes; the rest of the bulletin tells you how to play them.

The instrument below shows the danger levels the way the bulletins draw them and, crucially, how the terrain you can ski collapses as the level rises.

Going from Moderate to Considerable is not "a bit more careful": in a single step the danger front floods across the 30–33° band where most touring terrain lives, so the share of the mountain that's off-limits jumps by ~36 points — the largest bite on the whole scale, bigger than any other level-up. That is why level 3 carries the largest share of fatal accidents: it's the first level that engulfs a normal 30–34° touring slope while the day still feels manageable.

04Inside the BERA: the structure Météo-France actually uses

Open a BERA for any French massif (Vanoise, Pelvoux, Mont-Blanc, Haute-Bigorre…) and you find the same structure. Read it top to bottom, from most urgent to most detailed:

1. The massif and the validity. Each BERA covers one massif, not a point, and states the danger on its worst representative slope. Check the validity date: an old bulletin describes a snowpack that no longer exists.

2. The risk level, often split by elevation. Météo-France often gives two risk levels, one above and one below a stated altitude (e.g. 3 above 2,200 m, 2 below). That altitude is a real decision line: it usually marks where the wind-slab or persistent-weak-layer problem lives. Note it before anything else.

*3. The avalanche problems (situations avalancheuses typiques*). The heart of the bulletin. The BERA names the active problems — new snow, wind slab, persistent weak layer, wet snow, gliding snow — with the EAWS pictograms. The problem is more actionable than the number**: level 3 with a persistent weak layer on N–E aspects above 2,400 m tells you exactly what to avoid; level 3 alone tells you nothing useful.

*4. The aspect rose (orientations les plus dangereuses). A compass rose with the most dangerous aspects in black and the less dangerous, still-concerned ones in grey. It has no elevation bands: the elevations come from the split in block 2. It turns the prose into a picture of which slopes to stay off. (For why* aspect and elevation drive snow conditions, see Aspect & Elevation: How They Shape Snow.)

5. Triggered versus natural releases. In its snowpack-stability block, the BERA separates déclenchements provoqués (triggered, typically by a skier's weight) from départs spontanés (natural releases, from new snow, wind or daytime warming), listing the dominant one first. Triggered danger governs your slope choice; natural danger governs your exposure to slopes above you and your timing.

*6. The snowpack text (stabilité du manteau neigeux, qualité de la neige). The forecaster explains why*: buried layers, recent wind and snowfall, crusts. Here you learn whether you face a short-lived new-snow problem (a day or two) or a persistent weak layer (weeks, and far less forgiving).

*7. Precipitation and the trend (précipitations cumulées, tendance*). Past and forecast precipitation in 24-hour steps (snow in cm, rain in mm, usually at 1,800 m), then the tendance**: the risk level forecast for the following day, with a short comment. A rising trend means a deteriorating snowpack; a falling trend after a storm can make waiting a day worthwhile.

Decode key: the BERA is published only in French. The labels you will meet most often:

Read the rose against your route. List your route's aspects and the elevations where it is steeper than 30°. A steep section in a black sector, above the split altitude, is your crux: change the route, the timing or the objective. Start with the shaded sectors: in our avalanche records (6,659 geolocated avalanches), 62% of the fatal ones with a known aspect started on a N, NE or NW slope, against 54% of all records. The records name no avalanche problem, so read this as a lean, not a cause.

05The five avalanche problems (situations avalancheuses typiques): the BERA’s most useful line

EAWS defines five standard avalanche problems, and every modern bulletin names the ones in play. This line tells you how to move far more precisely than the danger number. (For a field guide to each, see The Five Avalanche Problem Types.)

*1. New snow (neige fraîche).* Fresh snow overloads the slope or bonds poorly to the old surface, and how hard a storm loads the slope depends on the snow's density, not just its depth. Worst during and just after the storm, on all aspects. Management: wait 24–48 hours and keep the slope angle down meanwhile.

*2. Wind slab (neige ventée*). Wind deposits dense, cohesive slabs on lee** slopes — classically NE–E–SE after W/NW winds — just below ridges and behind terrain features. The tell: smooth, pillowy, drum-like snow. Management: find the lee aspects from the bulletin and the wind history, and avoid the loaded pockets; they are localised but reactive.

*3. Persistent weak layer (couche fragile persistante*). The killer. Buried facets, depth hoar or surface hoar stay weak for weeks, deep where you cannot see them. They produce low-probability, high-consequence slabs that can release remotely, propagate wide and break above you, and the warning signs are buried. Management: big margins** — avoid the steep loaded aspects entirely and don't trust existing tracks. (See Understanding Snowpack Stability.)

*4. Wet snow (neige humide*). Meltwater from sun or rain weakens the snow, giving wet loose releases and wet slabs. A time-of-day* problem: frozen and safe at dawn, dangerous by early afternoon. Management: be on and off* sunny slopes early, with a hard turnaround time (see Spring Corn & the Melt-Freeze Cycle).

*5. Gliding snow (avalanches de fond*). The whole snowpack slides over smooth ground and opens glide cracks. Release timing is effectively unpredictable**. Management: never linger below or beside an open glide crack, at any danger level.

Common mistake: managing the wrong problem. You can ski around a localised wind slab by reading the terrain. You cannot ski around a persistent weak layer by being attentive, because it is buried, widespread and able to propagate across terrain features.

The interactive diagram below is a teaching model, not the BERA's own rose: it maps each problem onto aspect, elevation band and time of day, so you can watch where each one tends to sit on the mountain.

The danger number tells you the stakes; the avalanche problem tells you where and when. Wind slab hides on lee slopes below ridges, the persistent weak layer lurks on cold shaded aspects, and wet snow is a time-of-day problem on sunny faces — three different problems demanding three different plans, all under the same rating.

06Reading the BERA the night before: a worked example

Here is how to turn a bulletin into a plan, using a realistic mid-winter bulletin for an alpine massif:

Massif: Haute-Maurienne. Valid tomorrow. Danger: 3 (Marqué) above 2,200 m, 2 (Limité) below. Problems: persistent weak layer (sous-couche fragile) on N, NE, E above 2,400 m; localised wind slab on E–SE below ridgelines. Triggered: possible, even by a single skier, on the named steep aspects. Natural: isolated, mainly during the warmest hours on steep sunny slopes. Snowpack: a layer of faceted grains buried ~50–80 cm down on shaded aspects, formed during the cold clear spell two weeks ago; recent NW wind has built fresh slabs on lee slopes. Trend: steady.

Read it in order and turn it into decisions:

1. Elevation split → set a ceiling. Below 2,200 m on moderate terrain it is a level-2 day; above, a level-3 day. Decision: stay low, or accept level 3 and plan for it.
2. Persistent, not new → margins go up. A buried faceted layer is high-consequence and hard to detect. Decision: no steep (>30°) N/NE/E slopes above 2,400 m. Careful skiing is no answer, and existing tracks prove nothing.
3. The rose → pick your aspects. It would mark the cold N–E quadrant (persistent layer) plus E–SE (wind slab). Decision: route on south-leaning, lower-angle terrain away from lee loading.
4. Natural vs triggered → timing. The natural note flags the sunny aspects you now use. Decision: be off the steep sunny terrain before the afternoon warm-up, with a turnaround time.
5. Steady trend → no free pass. A persistent weak layer does not clear in a day. Decision: don't expect tomorrow to be safer.

The output isn't go or no-go; it is a shaped day: south-leaning, low-angle or below 2,400 m, off the cold steep aspects, finished before the afternoon.

Three Snow Trace topos in Haute-Maurienne show how one bulletin splits a valley. Pointe de la Met, north side from Bonneval-sur-Arc faces N and tops out at 3,041 m: squarely in the persistent-weak-layer sector, so not tomorrow. Pointe de Méan Martin from Le Villaron faces E up to 3,330 m: weak layer and lee pockets at once. Col des Fours from Bonneval-sur-Arc faces S up to 2,976 m: the candidate, provided its steep sunny slopes are behind you before the afternoon.

07Reading AINEVA, SLF & AEMET: same EAWS, different documents

Cross a border and the danger scale stays the same, but the document changes. All these services implement the EAWS standard, so you relearn the layout, not the concepts.

Italy — AINEVA and the regional services. AINEVA coordinates; the regional and provincial services (ARPA Piemonte, ARPA Veneto, the Aosta Valley, the autonomous provinces of Trento and Bolzano/Südtirol…) issue the bulletins. The bollettino valanghe is built around the grado di pericolo (danger level), the problemi valanghivi tipici (typical avalanche problems) and the aspect/elevation graphic. South Tyrol publishes in Italian and German. Vocabulary: neve ventata = wind slab, strato debole persistente = persistent weak layer, neve bagnata = wet snow.

Switzerland — SLF. The WSL Institute for Snow and Avalanche Research SLF in Davos issues the national bulletin in German, French, Italian and English. Its danger spots (Gefahrenstellen) and snowpack text map cleanly onto the BERA's blocks; the White Risk platform adds an interactive map. If you learn one foreign layout, make it SLF's English edition.

Spain — AEMET and the regional services. In the Spanish Pyrenees, AEMET issues the boletín de peligro de aludes (BPA); the Catalan service (ICGC) and, for the Val d'Aran, Lauegi publish their own bulletins. Same scale (peligro 1–5), same problems (placa de viento = wind slab, capa débil persistente = persistent weak layer, nieve húmeda = wet snow), per zone. For other ranges, check the regional source.

Austria — the Lawinenwarndienste and the Euregio bulletin. Each Austrian Land runs its own avalanche warning service. Tyrol, South Tyrol and Trentino share the Euregio bulletin (avalanche.report), published in seven languages: German, Italian, English, French, Spanish, Catalan and Aranese.

The constants and the variables. The scale and the five problems are identical everywhere: a 3 means the same in the Vanoise and in the Valais. Only the layout and the language change at each border.

08From bulletin to plan: making it a habit

The bulletin only protects you if reading it is a routine.

The night before.

1. Pull the current bulletin for your exact massif and check its validity.
2. Read the danger level and its elevation split, and set a ceiling if there is one.
3. Read the named avalanche problems: a persistent weak layer means big margins; settling new snow means patience; wet snow means an early start.
4. Hold the aspect rose against your route's steep aspects and elevations. Any overlap is your crux.
5. Note triggered vs natural, read the snowpack text and trend, then fix a shaped plan: aspects to ski, aspects to avoid, a turnaround time and a plan B.

In the field, verify it. Watch for the danger signs the bulletin cannot localise: recent avalanches, shooting cracks, whumpfs (collapsing), hollow drum-like snow, fresh wind loading, rapid warming (assess snowpack stability yourself). If what you see contradicts the bulletin, trust the slope, not the paper, and dial it back.

Where Snow Trace fits. Every route lists aspect and elevation, the official bulletin is one tap away on the map, and you can plan timing with the Munter method.

Read it every time. The most dangerous bulletin is the one you didn't open, or the one you opened, saw a 3, and closed.

*This article is educational and does not replace formal avalanche training, the official avalanche bulletin or your own judgement in the field. Get trained (the basics are in our avalanche safety guide), read the current bulletin for your massif, carry a transceiver, shovel and probe and know how to use them, and turn around when the snow tells you to.*

09Sources & further reading

Sources & further reading. Always defer to the current official bulletin for your massif and to hands-on training:

• **Météo-France — mountain weather and BERA** — the French Bulletin d'estimation du risque d'avalanche, per massif
• **ANENA — What is the BERA?** — publication time, validity, 35 massifs
• **ANENA — 50 years of avalanche accidents in France** (December 2023) — the 48% of fatal accidents at level 3
• **EAWS** — European Avalanche Warning Services: the shared scale and problem definitions
• **SLF** — WSL Institute for Snow and Avalanche Research, Davos (Swiss bulletin + White Risk; EN edition)
• **Avalanche.report** — the Euregio bulletin for Tyrol, South Tyrol and Trentino
• **AINEVA** — Italian inter-regional avalanche coordination
• **AEMET** — Spanish national meteorological agency (Pyrenean avalanche danger)
• McClung & Schaerer, The Avalanche Handbook — the standard technical reference